Wednesday, November 19, 2008

Acquired brain injury

A neurological condition, Acquired Brain Injury (ABI) is damage to the brain acquired after birth. It usually affects cognitive, physical, emotional, social or independent functioning and can result from traumatic brain injury (i.e. accidents, falls, assaults, etc.) and nontraumatic brain injury (i.e. stroke, brain tumours, infection, poisoning, hypoxia, ischemia or substance abuse). Most definitions of ABI exclude neurodegenerative disorders. Acquired brain injury is not to be confused with intellectual disability. People with a brain injury may have difficulty controlling, coordinating and communicating their thoughts and actions but they usually retain their intellectual abilities. Brain injury has dramatically varied effects and no two people can expect the same outcome or resulting difficulties. The brain controls every part of human life: physically, intellectually, behaviorally, socially and emotionally. When the brain is damaged, some other part of a person's life will also be adversely affected. Even a mild injury can sometimes result in a serious disability that will interfere with a person’s daily functioning and personal activities for the rest of their life. While the outcome of the injury depends largely on the nature and severity of the injury itself, appropriate treatment will play a vital role in determining the level of recovery.

Wednesday, November 12, 2008

Sudbury Basin


The Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is the second largest known impact crater or astrobleme on Earth, and a major geologic structure in Ontario, Canada.

The basin is located on the Canadian Shield in the city of Greater Sudbury, Ontario. The former municipalities of Rayside-Balfour and Valley East lie within the Sudbury Basin, which is referred to locally as "The Valley". The urban core of the former city of Sudbury lies on the southern outskirts of the Basin.

The Sudbury Basin is located near a number of other geological structures, including the Temagami Magnetic Anomaly, the Lake Wanapitei impact crater and the western end of the Ottawa-Bonnechere Graben, although none of the structures are directly related to each other in the sense of resulting from the same geophysical processes.

Monday, November 03, 2008

Visual modularity


In cognitive neuroscience, visual modularity is an organizational concept concerning how vision works. The way in which the primate visual system operates is currently under intense scientific scrutiny. One dominant thesis is that different properties of the visual world (colour, motion, form and so forth) require different computational solutions which are implemented in anatomically/functionally distinct regions that operate independently – that is, in a modular fashion (Calabretta & Parisi, 2005).

Thursday, October 30, 2008

Brain tumor


A brain tumor (brain tumour in the UK) is any intracranial tumor created by abnormal and uncontrolled cell division, normally either in the brain itself (neurons, glial cells (astrocytes, oligodendrocytes, ependymal cells), lymphatic tissue, blood vessels), in the cranial nerves (myelin-producing Schwann cells), in the brain envelopes (meninges), skull, pituitary and pineal gland, or spread from cancers primarily located in other organs (metastatic tumors). Primary (true) brain tumors are commonly located in the posterior cranial fossa in children and in the anterior two-thirds of the cerebral hemispheres in adults, although they can affect any part of the brain. In the United States in the year 2005, it was estimated that there were 43,800 new cases of brain tumors (Central Brain Tumor Registry of the United States, Primary Brain Tumors in the United States, Statistical Report, 2005 - 2006), which accounted for 1.4 percent of all cancers, 2.4 percent of all cancer deaths, and 20–25 percent of pediatric cancers.Ultimately, it is estimated that there are 13,000 deaths per year in the United States alone as a result of brain tumors.

Tuesday, October 21, 2008

Wheat


Modern body armor may combine a ballistic vest with other items of protective clothing, such as a helmet. Vests intended for police and military use may also include ballistic shoulder, and side protection armor components.

Wheat (Triticum spp.) is a worldwide cultivated grass from the Levant area of the Middle East. Globally, after maize, wheat is the second most produced food among the cereal crops; rice ranks third. Wheat grain is a staple food used to make flour for leavened, flat and steamed breads; cookies, cakes, pasta, juice, noodles and couscous;and for fermentation to make beer, alcohol, vodka or biofuel.Wheat is planted to a limited extent as a forage crop for livestock, and the straw can be used as fodder for livestock or as a construction material for roofing thatch.

Although wheat supplies much of the world's dietary protein and food supply, as many as one in every 100 to 200 people has Coeliac disease, a condition which results from an immune system response to a protein found in wheat: gluten (based on figures for the United States).

Monday, October 13, 2008

3G


3G is the third generation of mobile phone standards and technology, superseding 2.5G. It is based on the International Telecommunication Union (ITU) family of standards under the IMT-2000.

3G networks enable network operators to offer users a wider range of more advanced services while achieving greater network capacity through improved spectral efficiency. Services include wide-area wireless voice telephony, video calls, and broadband wireless data, all in a mobile environment. Additional features also include HSPA data transmission capabilities able to deliver speeds up to 14.4Mbit/s on the downlink and 5.8Mbit/s on the uplink.

Unlike IEEE 802.11 (common names Wi-Fi or WLAN) networks, 3G networks are wide area cellular telephone networks which evolved to incorporate high-speed internet access and video telephony. IEEE 802.11 networks are short range, high-bandwidth networks primarily developed for data.

Monday, September 29, 2008

High-speed Bluetooth


On March 28, 2006, the Bluetooth Special Interest Group announced its selection of the WiMedia Alliance Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) version of UWB for integration with current Bluetooth wireless technology.

UWB integration will create a version of Bluetooth wireless technology with a high-speed/high-data-rate option. This new version of Bluetooth technology will meet the high-speed demands of synchronizing and transferring large amounts of data, as well as enabling high-quality video and audio applications for portable devices, multi-media projectors and television sets, and wireless VOIP.

At the same time, Bluetooth technology will continue catering to the needs of very low power applications such as mouse, keyboards, and mono headsets, enabling devices to select the most appropriate physical radio for the application requirements, thereby offering the best of both worlds.

Tuesday, September 23, 2008

Default gateway


A gateway is a node (a router) on a computer network that serves as an access point to another network.

A Default Gateway (Def.GW) is the node on the computer network that is chosen when the IP address does not belong to any other entities in the Routing Table.

In homes, the gateway is usually the ISP-provided device that connects the user to the Internet, such as a DSL or cable modem.

In enterprises, however, the gateway is the node that routes the traffic from a workstation to another network segment. The default gateway is commonly used to be the node connecting the internal networks and the outside network (Internet). In such a situation, the gateway node could act as a proxy server and a firewall. The gateway is also associated with both a router, which uses headers and forwarding tables to determine where packets are sent, and a switch, which provides the actual path for the packet in and out of the gateway

Tuesday, September 16, 2008

Touch


Touch, also called tactition, mechanoreception or somatic sensation, is the sense of pressure perception, generally in the skin. There are a variety of nerve endings that respond to variations in pressure (e.g., firm, brushing, and sustained). The inability to feel anything or almost anything is called anesthesia. Paresthesia is a sensation of tingling, pricking, or numbness of a person's skin with no apparent long term physical effect.

Monday, September 08, 2008

Neolithic


"Neolithic" means "New Stone Age." This was a period of primitive technological and social development, toward the end of the "Stone Age." Beginning in the 10th millennium BCE (12,000 BP), the Neolithic period saw the development of early villages, agriculture, animal domestication, tools and the onset of the earliest recorded incidents of warfare.The Neolithic term is commonly used in the Old World, as its application to cultures in the Americas and Oceania that did not fully develop metal-working technology raises problems.

Tuesday, September 02, 2008

Personal Space as it Relates to Body Language


Generally, if you are closer than arm’s reach, then you are in someone’s personal space. To create more space in crowded areas such as elevators and bars, people often tense up and use their arms as protection. They will hold them close to their body – often crossed – and will also avoid eye contact. People guard their intimate space passionately, wherever it is, and do not appreciate others invading it. Respecting people’s intimate space involves not invading it with objects like bags or jackets, or with body parts unless they are welcomed. Intimate space is closer then 50 centimetres (18 inches), social is at around 50 centimetres (18 inches) - 1.5 metres (5 feet) and casual (for strangers) is at 1.5 - 3 metres (5-10 feet). These distances differ from culture to culture; in China for example, they are smaller.

Monday, August 25, 2008

Multitasking


Multitasking refers to the running of multiple independent computer programs on the same computer, giving the appearance that it is performing the tasks at the same time. Since most computers can do at most one or two things at one time, this is generally done via time sharing, which means that each program uses a share of the computer's time to execute.

An operating system kernel contains a piece of software called a scheduler which determines how much time each program will spend executing, and in which order execution control should be passed to programs. Control is passed to a process by the kernel, which allows the program access to the CPU and memory. At a later time control is returned to the kernel through some mechanism, so that another program may be allowed to use the CPU. This so-called passing of control between the kernel and applications is called a context switch.

An early model which governed the allocation of time to programs was called cooperative multitasking. In this model, when control is passed to a program by the kernel, it may execute for as long as it wants before explicitly returning control to the kernel. This means that a malfunctioning program may prevent any other programs from using the CPU.

The philosophy governing preemptive multitasking is that of ensuring that all programs are given regular time on the CPU. This implies that all programs must be limited in how much time they are allowed to spend on the CPU without being interrupted. To accomplish this, modern operating system kernels make use of a timed interrupt. A protected mode timer is set by the kernel which triggers a return to supervisor mode after the specified time has elapsed. (See above sections on Interrupts and Dual Mode Operation.)

On many single user operating systems cooperative multitasking is perfectly adequate, as home computers generally run a small number of well tested programs. Windows NT was the first version of Microsoft Windows which enforced preemptive multitasking, but it didn't reach the home user market until Windows XP, (since Windows NT was targeted at professionals.)

Tuesday, August 19, 2008

Community Ecology Data and methods


There are two methods of data collection: direct and indirect. Direct data come from vital statistics registries that track all births and deaths as well as certain changes in legal status such as marriage, divorce, and migration (registration of place of residence). In developed countries with good registration systems (such as the United States and much of Europe), registry statistics are the best method for estimating the number of births and deaths.

The census is the other common direct method of collecting demographic data. A census is usually conducted by a national government and attempts to enumerate every person in a country. However, in contrast to vital statistics data, which are typically collected continuously and summarized on an annual basis, censuses typically occur only every 10 years or so, and thus are not usually the best source of data on births and deaths. Analyses are conducted after a census to estimate how much over or undercounting took place. Censuses do more than just count people. They typically collect information about families or households, as well as about such individual characteristics as age, sex, marital status, literacy/education, employment status and occupation, and geographical location. They may also collect data on migration (or place of birth or of previous residence), language, religion, nationality (or ethnicity or race), and citizenship. In countries in which the vital registration system may be incomplete, the censuses are also used as a direct source of information about fertility and mortality; for example the censuses of the People's Republic of China gather information on births and deaths that occurred in the 18 months immediately preceding the census.

Indirect methods of data collections are required in countries where full data are not available, such as is the case in much of the developing world. One of these techniques is the sister method, where survey researchers ask women how many of their sisters have died or had children and at what age. With these surveys, researchers can then indirectly estimate birth or death rates for the entire population. Other indirect methods include asking people about siblings, parents, and children.

Monday, August 11, 2008

Reverse proxy server


A reverse proxy is a proxy server that is installed in the neighborhood of one or more web servers. All traffic coming from the Internet and with a destination of one of the web servers goes through the proxy server. There are several reasons for installing reverse proxy servers:

  • Encryption / SSL acceleration: when secure web sites are created, the SSL encryption is often not done by the web server itself, but by a reverse proxy that is equipped with SSL acceleration hardware. See Secure Sockets Layer.
  • Load balancing: the reverse proxy can distribute the load to several web servers, each web server serving its own application area. In such a case, the reverse proxy may need to rewrite the URLs in each web page (translation from externally known URLs to the internal locations).
  • Serve/cache static content: A reverse proxy can offload the web servers by caching static content like pictures and other static graphical content.
  • Compression: the proxy server can optimize and compress the content to speed up the load time.
  • Spoon feeding: reduces resource usage caused by slow clients on the web servers by caching the content the web server sent and slowly "spoon feeds" it to the client. This especially benefits dynamically generated pages.
  • Security: the proxy server is an additional layer of defense and can protect against some OS and WebServer specific attacks. However, it does not provide any protection to attacks against the web application or service itself, which is generally considered the larger threat.
  • Extranet Publishing: a reverse proxy server facing the Internet can be used to communicate to a firewalled server internal to an organization, providing extranet access to some functions while keeping the servers behind the firewalls. If used in this way, security measures should be considered to protect the rest of your infrastructure in case this server is compromised, as it's web application is exposed to attack from the Internet.

Monday, August 04, 2008

Reproduction in plants

In flowering plants,the anther produces male gametophytes, the sperm is produced in pollen grains, which attach to the stigma on top of a carpel, in which the female gametophytes (inside ovules) are located. After the pollen tube grows through the carpel's style, the sex cell nuclei from the pollen grain migrate into the ovule to fertilize the egg cell and endosperm nuclei within the female gametophyte in a process termed double fertilization. The resulting zygote develops into an embryo, while the triploid endosperm (one sperm cell plus two female cells) and female tissues of the ovule give rise to the surrounding tissues in the developing seed. The ovary, which produced the female gametophyte(s), then grows into a fruit, which surrounds the seed(s). Plants may either self-pollinate or cross-pollinate. Nonflowering plants like ferns, moss and liverworts use other means of sexual reproduction.

Ferns typically produce large diploid sporophytes with rhizomes, roots and leaves; and on fertile leaves called sporangium, spores are produced. The spores are released and germinate to produce short, thin gametophytes that are typically heart shaped, small and green in color. The gametophytes or thallus, produce both motile sperm in the antheridia and egg cells in separate archegonia. After rains or when dew deposits a film of water, the motile sperm are splashed away from the antheridia, which are normally produce on the top side of the thallus, and swim in the film of water to the antheridia where they fertilize the egg. To promote out crossing or cross fertilization the sperm are released before the eggs are receptive of the sperm, making it more likely that the sperm will fertilize the eggs of diffrent thallus. A zygote is formed after fertilization, which grows into a new sporophytic plant. The condition of having separate sporephyte and gametophyte plants is call alternation of generations. Other plants with similar reproductive means include the Psilotum, Lycopodium, Selaginella and Equisetum.

Monday, July 28, 2008

Prediction for a stable cultural and social future

Cultural evolution follows punctuated equilibrium which Gould and Eldredge developed for biological evolution. Bloomfield has written that human societies follow punctuated equilibrium which would mean first, a stable society, a transition resulting in a subsequent stable society with greater complexity. Using these guidelines, mankind has had a stable animal society, a transition to a stable tribal society, another transition to a stable peasant society and is currently in a transitional industrial society.

The status of a human society rests on the productivity of food production. Deevey reported on the growth of the number of humans. Deevey also reported on the productivity of food production, noting that productivity changes very little for stable societies, but increases during transitions. When productivity and especially food productivity can no longer be increased, Bloomfield has proposed that man will have achieved a stable automated society. Space is also assumed to allow for the continued growth of the human population, as well as provide a solution to the current pollution problem by providing limitless energy from solar satellite power stations.

Monday, July 21, 2008

Bronze Age

The term Bronze Age refers to a period in human cultural development when the most advanced metalworking (at least in systematic and widespread use) included techniques for smelting copper and tin from naturally-occurring outcroppings of copper and tin ores, creating a bronze alloy by melting those metals together, and cast them into bronze artifacts. These naturally-occurring ores typically included arsenic as a common impurity. Copper/tin ores are rare, as reflected in the fact that there were no tin bronzes in western Asia before 3,000 B.C. The Bronze Age forms part of the three-age system for prehistoric societies. In this system, it follows the Neolithic in some areas of the world. On the other hand, in many parts of sub-Saharan Africa, the Neolithic is directly followed by the Iron Age.[citation needed] In some parts of the world, a Copper Age follows the Neolithic and precedes the Bronze Age.

Tuesday, July 15, 2008

Phenotype

A phenotype is any observable characteristic of an organism, such as its morphology, development, biochemical or physiological properties, or behavior. Phenotypes result from the expression of an organism's genes as well as the influence of environmental factors and possible interactions between the two. The genotype of an organism are the inherited instructions it carries with in its genetic code. Not all organisms with the same genotype look or act the same way, because appearance and behavior are modified by environmental and developmental conditions. Also in the same way, not all organisms that look alike necessarily have the same genotype. This genotype-phenotype distinction was proposed by Wilhelm Johannsen in 1911 to make clear the difference between an organism's heredity and what that heredity produces. The distinction is similar to that proposed by August Weismann, who distinguished between germ plasm (heredity) and somatic cells (the body). A more modern version is Francis Crick's Central dogma of molecular biology.

Despite its seemingly straightforward definition, the concept of the phenotype has some hidden subtleties. First, most of the molecules and structures coded by the genetic material are not visible in the appearance of an organism, yet they are observable (for example by Western blotting) and are thus part of the phenotype. Human blood groups are an example. So, by extension, the term phenotype must include characteristics that can be made visible by some technical procedure. Another extension adds behaviour to the phenotype since behaviours are also affected by both genotypic and environmental factors.

Second, the phenotype is not simply a product of the genotype, but is influenced by the environment to a greater or lesser extent (see also phenotypic plasticity). And, further, if the genotype is defined narrowly, then it must be remembered that not all heredity is carried by the nucleus. For example, mitochondria transmit their own DNA directly, not via the nucleus, though they divide in unison with the nucleus.

The phenotype is composed of traits or characteristics . Some phenotypes are controlled entirely by the individual's genes. Others are controlled by genes but are significantly affected by extragenetic or environmental factors. Almost all humans inherit the capacity to speak and understand language, but which language they learn is entirely an environmental matter.

Sunday, July 06, 2008

Duel

As practised from the 11th to 20th centuries in Western societies, a duel is an engagement in combat between two individuals, with matched weapons in accordance with their combat doctrines. In the modern application the term is applied to air combat between fighter pilots.

The Romanticism depiction of medieval duels was based on either a pretext of defence of honor, usually accompanied by a trusted representative (who might themselves fight), often in contravention of the duelling conventions, or as a matter of challenge of the champion which developed out of the desire of one party (the challenger) to redress a perceived insult to his or his sovereign's honor. The goal of the honourable duel was often not so much to kill the opponent as to gain "satisfaction", that is, to restore one's honor by demonstrating a willingness to risk one's life for it.

Duels may be distinguished from trials by combat, in that duels were not used to determine guilt or innocence, nor were they official procedures. Indeed, from early 19th century duels were often illegal in Europe, though in most societies where duelling was socially accepted, participants in a fair duel were not prosecuted, or if they were, were not convicted. Only gentlemen were considered to have honor, and therefore only they were qualified to duel. If a gentleman was insulted by a person of lower class, he would not duel him, but would beat him with a cane, riding crop, a whip or have his servants do so.[citation needed] Duelling is now illegal in all but a few countries around the world.[citation needed]

Sunday, June 29, 2008

Albinism Treatment of the symptoms

Albinism is a condition that cannot be "cured" per se, but small things can be done to improve the quality of life for those affected. Most importantly to improve vision, protect the eyes from bright lights, and avoid skin damage from sunlight. The extent and success rate of these measures depend on the type of albinism and severity of the symptoms; in particular, people with ocular albinism are likely to have normally-pigmented skin, and thus do not need to take special precautions against skin damage.

Surgical treatment

For the most part, treatment of the eye conditions consists of visual rehabilitation.[citation needed] Surgery is possible on the ocular muscles to decrease nystagmus, strabismus and common refractive errors like astigmatism. Strabismus surgery may improve the appearance of the eyes.[citation needed] Nystagmus-damping surgery can also be performed, to reduce the "shaking" of the eyes back and forth.The effectiveness of all these procedures varies greatly and depends on individual circumstances. More importantly, since surgery will not restore a normal RPE or foveae, surgery will not provide fine binocular vision.[citation needed] In the case of esotropia (the "crossed eyes" form of strabismus), surgery may help vision by expanding the visual field Vision aids.

Glasses and other vision aids, large-print materials and closed captioning, as well as bright but angled reading lights, can help individuals with albinism, even though their vision cannot be corrected completely. Some albinistic people do well using bifocals (with a strong reading lens), prescription reading glasses, and/or hand-held devices such as magnifiers or monoculars.

Contact lenses may be colored to block light transmission through the iris. Some use bioptics, glasses which have small telescopes mounted on, in, or behind their regular lenses, so that they can look through either the regular lens or the telescope. Newer designs of bioptics use smaller light-weight lenses. Some US states allow the use of bioptic telescopes for driving motor vehiclesAlthough still disputed among the experts,[who?] many ophthalmologists recommend the use of glasses from early childhood onward to allow the eyes the best development possible.
Optometrists or ophthalmologists who are experienced in working with low vision patients can recommend various optical aids. Some low-vision clinics provide these aids on trial loan, with instruction in their use.

Sun protection

It is vital that people with albinism use sunscreen when exposed to sunlight to prevent premature skin aging or skin cancer. This poses a problem for those who cannot afford sunscreen, especially in regions with high exposure to sunlight, as in Africa.

Use of sunglasses and hats with wide brims can make the glare outside bearable. Other things that can help people with albinism are avoiding sudden changes of the lighting situation (switching the light on in complete darkness), using dimmable switches and adding tint to car windows or blinds to normal windows. Lights should be yellowish rather than blue[citation needed] and not point towards the usual position of a person with albinism

Sunday, June 22, 2008

Sporophyte

All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or alga that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants and in some green algae. For common flowering plants (Angiosperms), the sporophyte generation comprises almost their whole life cycle (i.e. whole green plant, roots etc), except phases of small reproductive structures (pollen and ovule).

The sporophyte produces spores (hence the name), by meiosis. These meiospores develop into a gametophyte. Both the spores and the resulting gametophyte are haploid, meaning they only have one set of homologous chromosomes. The mature gametophyte produces male or female gametes (or both) by mitosis. The fusion of male and female gametes produces a diploid zygote which develops into a new sporophyte. This cycle is known as alternation of generations or alternation of phases.

n the normal course of events, the zygote and sporophyte will have a full double set of chromosomes again. An exception is when a diploid and haploid gamete fuse, resulting in a triploid sporophyte, which will usually be sterile, as dividing three sets of chromosomes into two halves causes complications.

Bryophytes (mosses, liverworts and hornworts) have a dominant gametophyte stage on which the adult sporophyte is dependent on the gametophyte for nutrition. The embryo of the sporophyte develops from the zygote within the female sex organ or archegonium, and in its early development is therefore nurtured by the gametophyte. Because this embryo-nurturing feature of the life cycle is common to all land plants they are known collectively as the Embryophytes.

Most algae have dominant gametophyte generations, but in some species the gametophytes and sporophytes are morphologically similar (isomorphic). An independent sporophyte is the dominant form in all clubmosses, horsetails, ferns, gymnosperms, and angiosperms (flowering plants) that have survived to the present day. Early land plants had sporophytes that produced identical spores (isosporous or homosporous) but the ancestors of the gymnosperms evolved complex heterosporous life cycles in which the spores producing male and female gametophytes were of different sizes, the female megaspores tending to be larger, and fewer in number, than the male microspores.

During the Devonian period several plant groups independently evolved heterospory and subsequently the habit of endospory, in which single megaspores were retained within the sporangia of the parent sporophyte, instead of being freely liberated into the environment as in ancestral exosporous plants. These endosporic megaspores contained within them a miniature multicellular female gametophyte complete with female sex organs or archegonia containing oocytes which were fertilised by free-swimming sperm produced by windborne miniatuarised male gametophytes in the form of pre-pollen. The resulting zygote developed into the next sporophyte generation while still retained within the pre-ovule, the single large female meiospore or megaspore contained in the modified sporangium or nucellus of the parent sporophyte. The evolution of heterospory and endospory were among the earliest steps in the evolution of seeds of the kind produced by gymnosperms and angiosperms today.

Sunday, June 15, 2008

Field-programmable gate array

A field-programmable gate array is a semiconductor device containing programmable logic components called "logic blocks", and programmable interconnects. Logic blocks can be programmed to perform the function of basic logic gates such as AND, and XOR, or more complex combinational functions such as decoders or mathematical functions. In most FPGAs, the logic blocks also include memory elements, which may be simple flip-flops or more complete blocks of memory.

A hierarchy of programmable interconnects allows logic blocks to be interconnected as needed by the system designer, somewhat like a one-chip programmable breadboard. Logic blocks and interconnects can be programmed by the customer or designer, after the FPGA is manufactured, to implement any logical function—hence the name "field-programmable".

FPGAs are usually slower than their application-specific integrated circuit (ASIC) counterparts, cannot handle as complex a design, and draw more power (for any given semiconductor process). But their advantages include a shorter time to market, ability to re-program in the field to fix bugs, and lower non-recurring engineering costs. Vendors can sell cheaper, less flexible versions of their FPGAs which cannot be modified after the design is committed. The designs are developed on regular FPGAs and then migrated into a fixed version that more resembles an ASIC.

"Complex Programmable Logic Device" (CPLDs) are an alternative for simpler designs. They also retain their programming over powerdowns.

To configure ("program") an FPGA or CPLD you specify how you want the chip to work with a logic circuit diagram or a source code using a hardware description language (HDL). The HDL form might be easier to work with when handling large structures because it's possible to just specify them numerically rather than having to draw every piece by hand. On the other hand, schematic entry might allow for a more tight specification of what you want.

Going from schematic/HDL source files to actual configuration: The source files are fed to a software suite from the FPGA/CPLD vendor that through different steps will produce a file. This file is then transferred to the FPGA/CPLD via a serial interface (JTAG) interface or to external memory device like an EEPROM.

Sunday, June 08, 2008

Ultra Music Festival

Ultra Music Festival is an outdoor electronic music event held annually in Miami, Florida during the Winter Music Conference which occurs annually during the month of March. It is a 2-day event (although it was a 1-day event until 2007) that takes place across 12 different stages featuring over 200 artists, DJs, producers and promoters.

From 2001 to 2005, UMF was held outdoors in Bayfront Park, Miami. The first two UMFs (1999, & 2000) were actually held on South Beach in Miami Beach, however UMF attendance exceeded the possible beach permits and was subsequently moved to the venue of Bayfront Park. The top DJs and artists of the evening perform in the amphitheater designed to hold thousands of attendees. There is a second main stage (called the 'Sound stage') and 10 other specialized music areas scattered throughout the park featuring Drum and Bass, House, Techno, Electro, Breakbeats, Trance, and other various styles of electronic music.
In 2005 the concert was so popular that it sold out. With the festival growing so big, in 2006 the Miami event had been moved to an even bigger venue, Bicentennial Park, next door to its past home. In 2007, with Winter Music Conference in full swing, Ultra Music Festival had its first 2-Day Event held at Bicentennial Park with a record breaking 50,000+ electronic music fans. Ultra Music Festival celebrated its 10th anniversary on Friday, March 28th and Saturday March 29th, 2008, where an announcement was made that the festival had set a new City of Miami record for the number of tickets sold at a single event.

Ultra Music Festival, in association with Ultra Records, produces an event in New York City's Central Park called ULTRA:NY, which also sold out in 2005. The success has brought Ultra:NY back for a second year.

Monday, June 02, 2008

Human circulatory system

The main components of the human circulatory system are the heart, the blood, and the blood vessels. The circulatory system includes: the pulmonary circulation, a "loop" through the lungs where blood is oxygenated; and the systemic circulation, a "loop" through the rest of the body to provide oxygenated blood. An average adult contains five to six quarts (roughly 4.7 to 5.7 liters) of blood, which consists of plasma that contains red blood cells, white blood cells, and platelets.

Two types of fluids move through the circulatory system: blood and lymph. The blood, heart, and blood vessels form the cardiovascular system. The lymph, lymph nodes, and lymph vessels form the lymphatic system. The cardiovascular system and the lymphatic system collectively make up the circulatory system.

Wednesday, May 28, 2008

The library as an intermediary

Generally, operating systems provide a library that sits between normal programs and the rest of the operating system, usually the C library (libc), such as glibc. This library handles the low-level details of passing information to the kernel and switching to supervisor mode, as well as any data processing and preparation which does not need to be done in privileged mode. Ideally, this reduces the coupling between the operating system and the application, and increases portability.

On exokernel based systems, the library is especially important as an intermediary. On exokernels, OSes shield user applications from the very low level kernel API, and provide abstractions and resource management

Tuesday, May 27, 2008

Understanding the Context

Many different methods of communication are possible on the Internet; some use specific software and all involve text and/or graphics.

* Some activities take place in real-time while others allow for a delayed reply.

* Discussion areas may be public or exist for a particular group of people.

* Information can either be broadcast or targeted at a particular user.

As the technology develops, and users and providers become more proficient, the boundaries between the different Internet services are blurred. For example, email is used in chat rooms, web pages include discussion areas and newsgroups can have files attached.

Each Internet service has its own educational value, risks, and recommended ways of dealing with problems, and these are detailed in the following pages. They are not exhaustive and many apply across Internet services. Schools should consider the sum of the advice in these guidelines across all areas.

Thursday, May 22, 2008

Overview of the Click Thinking Pack

Schools and government initiatives are encouraging the educational use of the Internet right across the curriculum and young people are taking readily to this way of learning and communicating.

At the same time, the media tends to focus on the rare occasions when use of the Internet causes distress. The Scottish Executive believes that young people need to be protected and informed; and that those responsible for them, whether teachers, parents or other careers, should be aware of the issues involved.

Previous Scottish Executive Education Department (SEED) publications in this area have dealt with the need to protect pupils from misuse of computers (Information Ethics) and to understand copyright implications (Copyright and Ethics in a Digital Age).

This booklet focuses on personal safety and wellbeing. It attempts to clarify potential risks and to empower Internet users in schools so that they can keep themselves safe. Those who manage Scottish schools, and all teachers, whether responsible for a primary class or for teaching a subject, will find policy guidelines and background information which will prepare our pupils to take their safe and well-earned place in the Digital Age.

Much of the advice in these guidelines will be relevant to other Local Authority staff responsible for overseeing young people's use of the Internet (e.g. managers and staff in community education centers, residential homes for young people, libraries and other settings). These groups should take account of the messages about personal safety, and put into place the recommendations suitable for their setting.

Wednesday, May 07, 2008

BACK TO SCHOOL SAFETY ALERT:

CPSC Urges Bicyclists to Wear Helmets

CPSC Document #5002

Each year about 800 bicyclists are killed and more than half a million are treated in hospital emergency rooms. In recent years, almost two-thirds of the deaths and one-third of the injuries involved head and face injury. About one-half the injuries to children under the age of 10 involved the head or face. Helmets may reduce the risk of head injury to bicyclists by as much as 85 percent. Yet, only about 50 percent of bicyclists wear helmets.

The purpose of a helmet is to absorb the energy of an impact to minimize or prevent a head injury. Crushable, expanded polystyrene foam generally is used for this purpose.

A bicycle helmet should have a snug but comfortable fit on the rider's head. Some helmets are available with several different thicknesses of internal padding to custom fit the helmet to the user. If a parent is buying a helmet for a child, the CPSC recommends that the child accompany the parent so that the helmet can be tested for a good fit.

For a helmet to provide protection during impact, it must have a chin strap and buckle that will stay securely fastened. No combination of twisting or pulling should remove the helmet from the head or loosen the buckle on the strap. Children should be instructed to always wear the helmet level on the forehead, not tilted back. The chin strap should be adjusted correctly and firmly buckled.

Helmets manufactured after March 1999, are required by federal law to meet the CPSC standard. When purchasing a helmet, consumers are urged to examine the helmet and accompanying instructions and safety literature carefully. Consumers should also look for a label stating conformance with the CPSC standard.

Bicyclists should avoid riding at night. If you must ride at night, install and use front and rear lights on the bicycle and wear clothing with reflective tape or markings. These precautions are in addition to the reflectors that the CPSC requires to be on the front, rear, pedals, and wheels of bicycles.

Many bicycle-car crashes can be avoided by applying the rules of the road and by increasing attentiveness of cyclists and motorists. Bicyclists have a legal right to share the road, but they are often not noticed in traffic. Drivers should always keep an eye out for bicyclists, especially when turning, merging, changing lanes, or entering intersections.

Monday, April 28, 2008

All-Terrain Vehicle Safety

Too many ATV riders -- young and old -- are dying or experiencing life altering injuries from incidents involving ATVs. The U.S. Consumer Product Safety Commission (CPSC) recommends that all ATV riders follow the seven safety tips below every time they ride.

An estimated 740 people died in 2003* in incidents associated with ATVs. In addition, in 2004* there were an estimated 136,100 emergency room treated injuries associated with ATVs. About a third of all deaths and injuries involved victims under 16 years old. CPSC also reported that ridership has continued to grow, with 6.2 million 4-wheeled ATVs in use in 2003*.

The major ATV manufacturers agreed in Consent Decrees in 1988 and in subsequent voluntary action plans that they would not manufacture three-wheel ATVs; they would place engine size restrictions on ATVs sold for use by children under 16; and they would offer driver-training programs.

Children and young people under the age of 16 should not ride adult ATVs.

All ATV users should take a hands-on safety training course.

Always wear a helmet and safety gear such as boots and gloves while on an ATV.

Never drive an ATV on paved roads.

Never drive while under the influence of drugs or alcohol.

Never drive a youth or single-rider adult ATV with a passenger, and never ride these vehicles as a passenger.

There are some ATVs that are designed for two riders. Passengers on tandem ATVs should be at least 12 years old.

Monday, April 21, 2008

J-Hook Shaped Stake style (Anchor Types)

This style is used when holes are not pre-drilled into the ground shoes (bars) or rear ground shoe (bar) of the goal. Similar to the peg or stake style, this anchor is hammered, at an angle if possible, directly into the earth. The curved (top) portion of this anchor fits over the goal member to secure it to the ground. Typically, two to four stakes of this type are recommended (per goal), depending on stake structure, manufacturers specifications, weight of goal, and soil conditions. Stakes with larger diameters or textured surfaces have greater holding capacity.

Monday, April 14, 2008

Anchoring/Securing/Counterweighing Guidelines

A properly anchored/counterweighted movable soccer goal is much less likely to tip over. Remember to secure the goal to the ground (preferably at the rear of the goal), making sure the anchors are flush with the ground and clearly visible. It is IMPERATIVE that ALL movable soccer goals are always anchored properly (see Figure 2). There are several different ways to secure your soccer goal. The number and type of anchors to be used will depend on a number of factors, such as soil type, soil moisture content, and total goal weight.

Monday, April 07, 2008

Soccer Goal Injuries and Deaths

According to the 1994 National Soccer Participation Survey (Soccer Industry Council of America), over 16 million persons in the United States play soccer at least once a year. Seventy-four percent (over 12 million) of these persons are under the age of 18. Soccer ranks fourth in participation for those under 18, following basketball, volleyball, and softball and well ahead of baseball, which has an annual participation of 9.7 million.
There are approximately 225,000 to 500,000 soccer goals in the United States. Many of these soccer goals are unsafe because they are unstable and are either unanchored or not properly anchored or counter-balanced. These movable soccer goals pose an unnecessary risk of tip over to children who climb on goals (or nets) or hang from the crossbar.
The CPSC knows of four deaths in 1990 alone and at least 21 deaths during the past 16 years (1979-1994) associated with movable soccer goals. In addition, an estimated 120 injuries involving falling goals were treated each year in U.S. hospital emergency rooms during the period 1989 through 1993. Many of the serious incidents occurred when the soccer goals tipped over onto the victim. Almost all of the goals involved in these tip over appeared to be home-made by high school shop classes, custodial members, or local welders, not professionally manufactured. These home-made goals are often very heavy and unstable.
The majority of movable soccer goals are constructed of metal, typically weighing 150-500 pounds. The serious injuries and deaths are a result of blunt force trauma to the head, neck, chest, and limbs of the victims. In most cases this occurred when the goal tipped or was accidentally tipped onto the victim. In one case an 8-year-old child was fatally injured when the movable soccer goal he was climbing tipped over and struck him on the head. In another case, a 20-year-old male died from a massive head trauma when he pulled a goal down on himself while attempting to do chin-ups. In a third case, while attempting to tighten a net to its goal post, the victim’s father lifted the back base of the goal causing it to tip over striking his 3-year-old child on the head, causing a fatal injury.
High winds can also cause movable soccer goals to fall over. For example, a 9-year-old was fatally injured when a goal was tipped over by a gust of wind. In another incident, a 19-year-old goalie suffered stress fractures to both legs when the soccer goal was blown on top of her.

Sunday, March 30, 2008

B.C.-Canada Place officially closes doors

Monday, March 20, 2006 marks the official close of British Columbia-Canada Place, one of the most successful attractions of the 2006 Torino Olympic and Paralympic Winter Games.

Over the course of the 2006 Olympic and Paralympic Winter Games, British Columbia-Canada Place drew more than 100,000 visitors and journalists. These visitors were able to experience first hand the province’s culture, heritage, natural beauty and bustling cities. Also, more than 80 British Columbia businesses were able to connect with an international audience and showcase some of B.C.’s best products and services.

B.C.-Canada Place will be a legacy to the people of Torino. The official transfer took place in a ceremony yesterday, with Torino Mayor Sergio Chiamparino accepting a ceremonial key to the building.

“This generous gift from British Columbia will be a constant reminder of our friends in Canada and the celebrations that took place in our city during the 2006 Winter Games,” says Mayor Chiamparino. “We are honored to have this permanent B.C. presence in our city.”

Monday, March 24, 2008

Kent Kickin' Mini-Scooters

Kent is recalling about 90,000 scooters. The scooter handles can unexpectedly come out of the steering column if the clamp holding them in is not tight, causing the rider to lose control, fall and possibly suffer injuries.
Kent has received four reports of the handles coming out, resulting in four children suffering injuries, including broken arms, a broken wrist, bruises, abrasions and a cracked tooth.
These are Kickin' Mini-Scooters made of chrome-plated steel. A vertical decal on the steering column reads "KICKIN' MINI SCOOTER." The scooter's black plastic platform measures about 15 inches long, and it has 4-inch translucent in-line style wheels. "KENT" and "MADE IN CHINA" are written on the lower part of the steering column. The scooters were sold with black backpacks embroidered in white with the word "Kickin."
Toys R us stores nationwide sold the Kent scooters from May 2000 through September 2000 for about $60.
Consumers should stop riding these Kent scooters immediately, and call Kent International to receive a free replacement handlebar with pins to secure the handlebars. For more information, call Kent International at (800) 451-KENT (5368) between 8 a.m. and 5 p.m. ET Monday through Friday.
Kent has sold other models to Toys R Us such as the Street Craze, the Street Racer and Scoot that are NOT part of this recall. Scooters that Kent sold to Wal Mart, Meijer's, Target and AAFES are also NOT part of this recall.

Monday, March 17, 2008

Trampoline Safety Alert

The U. S. Consumer Product Safety Commission (CPSC) wants you and your family to be safe when using trampolines. The CPSC estimates that in 2001 there were 91,870 hospital emergency room-treated injuries associated with trampolines. About 93 percent of the victims were under 15 years of age, and 11 percent were under 5 years of age. Since 1990, CPSC has received reports of 6 deaths of children under age 15 involving trampolines. Injuries and deaths were caused by:

* Colliding with another person on the trampoline.
* Landing improperly while jumping or doing stunts on the trampoline.
* Falling or jumping off the trampoline.
* Falling on the trampoline springs or frame.
Most of the trampolines associated with injuries were at private homes.
Here are the steps you can take to help prevent serious trampoline injuries, especially paralysis, fractures, sprains, and bruises:

* Allow only one person on the trampoline at a time.
* Do not attempt or allow somersaults because landing on the head or neck can cause paralysis.
* Do not use the trampoline without shock-absorbing pads that completely cover its springs, hooks, and frame.
* Place the trampoline away from structures, trees, and other play areas.
* No child under 6 years of age should use a full-size trampoline. Do not use a ladder with the trampoline because it provides unsupervised access by small children.
* Always supervise children who use a trampoline.
* Trampoline enclosures can help prevent injuries from falls off trampolines.

Monday, March 10, 2008

Accumulator

In a computer CPU, an accumulator is a register in which intermediary arithmetic and logic results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to main memory, possibly only to be read right back again for use in the next operation. Access to main memory is slower than access to a register like the accumulator because the technology used for the huge main memory is slower (but cheaper) than that used for a register.

The canonical example for accumulator use is adding a list of numbers. The accumulator is initially set to zero, then each number in spin is added to the value in the accumulator. Only when all numbers have been added is the result seized in the accumulator written to main memory or to another, non-accumulator, CPU register.

Monday, February 25, 2008

Roll-to-roll processing,

Roll-to-roll processing, also known as 'web' processing, is the process of creating electronic devices on a roll of flexible plastic or metal foil. Large circuits made with thin-film transistors and other devices can be easily patterned onto these large substrates, which can be up to a few metres wide and 50 km long. Some of the devices can be patterned directly, much like an inkjet printer deposits ink. For most semiconductors, however, the devices must be patterened using photolithography techniques.

Sunday, February 17, 2008

Tissue engineering

One of the goals of tissue engineering is to create artificial organs for patients that need organ transplants. Biomedical engineers are currently researching methods of creating such organs. In one case bladders have been grown in lab and transplanted successfully into patients. Bioartificial organs, which utilize both synthetic and biological components, are also a focus area in research, such as with hepatic assist devices that utilize liver cells within an artificial bioreactor construct.

Wednesday, November 14, 2007

A general view on Computer

A computer is a machine capable of processing data according to a program — a list of instructions. The data to be processed may possibly represent many types of information counting numbers, text, pictures, or sound. The short definition for COMPUTER is “common oriented machine particularly used for technical and educational research”.

Computers can be very versatile. In actual fact, they are universal information processing machines. As said by the Church-Turing thesis, a computer with a certain minimum threshold capability is in principle competent of performing the tasks of any other computer, from those of a personal digital supporter to a supercomputer. So, the same computer designs have been modified for tasks from processing company payrolls to controlling industrial robots. Modern electronic computers also have great speed and capability for information processing compared to earlier designs, and they have become exponentially very powerful over the years (it is a phenomenon known as Moore's Law).

Computers are obtainable in many physical forms. The original computers were the size of a large room, and such great computing facilities still exist for specialized scientific computation - supercomputers - and for the business deal processing requirements of large companies, in general called mainframes. Smaller computers for personage use, called personal computers, and their handy equivalent, the notebook computer, are ubiquitous information-processing and communication tools and are perhaps what most non-experts imagine of as "a computer". However, the most ordinary form of computer in use today is the embedded computer, small computers used to manage another device. The Embedded computers control machines from the fighter planes to digital cameras.

Sunday, November 04, 2007

Box

This article is about the container or vessel called a box. For other uses, see Box (disambiguation).

An elaborate wooden box Boxes are extremely variable receptacles. When no shape is described, a typical rectangular box may be expected. Nevertheless, a box may have a horizontal cross section that is square, elongated, round or oval; sloped or domed top surfaces, or non-vertical sides. A box normally may be opened by raising, sliding or removing the lid, which may be hinged and/or secure by a catch, clasp, or lock. Whatever its shape or purpose or the material of which it is formed, it is the direct descendant of the chest, one of the most ancient articles of marital furniture. Its uses are innumerable, and the name, preceded by a qualifying adjective, has been given to many objects of imaginative or antiquarian interest. Objects are often placed inside boxes, for a multiplicity of reasons - see storage.

Sunday, October 28, 2007

The real facts about Neptune

Neptune is the eighth planet from the Sun and the fourth largest (by diameter) of the planet. Neptune is smaller in diameter but bigger in mass than Uranus. Neptune's composition is almost certainly alike to Uranus': various "ices" and rock with about 15% hydrogen and a little helium. Like Uranus, but unlike Jupiter and Saturn, it can not have a distinct internal layering but rather to be more or less uniform in composition. But there is most expected a small core (about the mass of the Earth) of rock-strewn material. Its atmosphere is generally hydrogen and helium with a minute amount of methane.

Neptune's blue color is mainly the result of absorption of red light by methane in the atmosphere but there is a number of additional as-yet-unidentified chromophore which gives the clouds their rich blue tint. Like Jupiter and Saturn, Neptune has an inner heat source -- it radiates more than, twice as much energy as it receives from the Sun.

Neptune also has rings. Earth-based observations showed just faint arcs rather than complete rings, but Voyager 2's images showed them to be entire rings with bright clumps. One of the rings looks to have a curious twisted structure (right). Like Uranus and Jupiter, Neptune's rings are extremely dark but their composition is unknown.

Neptune's rings have been noted names: the outermost is Adams (which contains three important arcs now named Liberty, Equality and Fraternity), next is an unnamed ring co-orbital with Galatea, then Leverrier (whose outer extensions are called Lassell and Arago), and lastly the faint but broad Galle. Neptune's magnetic field is, like Uranus', oddly oriented and most likely generated by motions of conductive material (probably water) in its middle layers.

Friday, October 26, 2007

The real facts about Pluto

Pluto orbits away from the orbit of Neptune (usually). It is greatly smaller than any of the official planets and currently classified as a "dwarf planet". Pluto is lesser than seven of the solar system's moons (the Moon, Io, Europa, Ganymede, Callisto, Titan and Triton). Pluto has been given number 134340 in the minor planet catalog. Pluto's orbit is extremely eccentric. At times it is nearer to the Sun than Neptune (as it was from January 1979 thru February 11 1999). Pluto rotates in the conflicting direction from most of the other planets.

Pluto is safe in a 3:2 resonance with Neptune; i.e. Pluto's orbital period is just 1.5 times longer than Neptune's. Its orbital inclination is as well much higher than the other planets'. Thus though it looks that Pluto's orbit crosses Neptune's, it actually doesn't and they will never collide. Pluto's composition is unidentified, but its density (about 2 gm/cm3) indicates that it is almost certainly a mixture of 70% rock and 30% water ice much like Triton. The bright areas of the surface appear to be covered with ices of nitrogen with lesser amounts of (solid) methane, ethane and carbon monoxide. The composition of the darker areas of Pluto's surface is unidentified but may be due to primordial organic material or photochemical reactions driven by cosmic rays.

Little is recognized about Pluto's atmosphere, but it perhaps consists primarily of nitrogen with some carbon monoxide and methane. It is very tenuous, the surface pressure being only some microbars. Pluto's atmosphere can exist as a gas only when Pluto is near its perihelion; for the greater part of Pluto's long year, the atmospheric gases are frozen into ice. Close to perihelion, it is likely that some of the atmosphere escapes to space possibly even interacting with Charon. NASA mission planners want to appear at Pluto while the atmosphere is still unfrozen.

Tuesday, October 16, 2007

Butter chicken

Butter chicken or murgh makhani is an Indian dish accepted in countries all over the world that have a tradition of Indian restaurants. While the dish's general recipe is well known, the actual flavour can differ from restaurant to restaurant even within Delhi. Butter chicken is usually served with naan, roti, parathas or steamed rice.

It is a dish prepared by marinating a chicken overnight in a yoghurt and spice mixture usually together with garam masala, ginger, lemon or lime, pepper, coriander, cumin, turmeric, chilli, methi and garlic. It is in various ways like to chicken tikka masala. The chicken is then roasted or dry as a bone.

Monday, October 08, 2007

Fresh skin-care tips

Select fresh, organically grown fruit and vegetables for the highest benefits. Avoid making more than you require for a single application.Clean and sanitize all countertops and mixing utensils ahead of making any of the recipes. Clean all fruit and vegetables before using as ingredients. Leave all ingredients out of the fridge for up to an hour before integration. Don't let fruit acquire any warmer than room temperature.

Fresh fruit and vegetables are especially high in acids. If you apply anything to your skin and encounter a burning sensation, take out immediately and apply cool water.If you are in the care of a dermatologist and on acne medications, please consult with your physician first.

Sunday, September 23, 2007

Traffic Claming

Traffic calming is a set of strategies used by urban planners and traffic engineers which aims to slow down traffic and get better safety for pedestrians and bicyclists, although some of these features can also be hazardous to cyclists. It is now comparatively common in Europe, especially Northern Europe; less so in North America.Traffic calming has conventionally been justified on the grounds of pedestrian safety and reduction of noise and local air pollution which are side effects of the traffic. However, it has become more and more apparent that streets have many social and recreational functions which are severely impaired by fast car traffic. For much of the twentieth century, streets were designed by engineers who were charged only with ensuring traffic flow and not with development other functions of streets. The rationale for traffic reassuring is now broadening to include designing for these functions.

Thursday, September 13, 2007

Asian Paradise Flycatcher

The Asian Paradise Flycatcher, also known as the Common Paradise Flycatcher, is a medium-sized passerine bird. It was in the past classified with the Old World flycatcher family Muscicapidae, but the paradise flycatchers, monarch flycatchers and Australasian fantails are now usually grouped with the drongos in the family Dicruridae, which has the majority of its members in Australasia and tropical southern Asia.

The Asian glory Flycatcher breeds from Turkestan to Manchuria. It is wandering, wintering in tropical Asia. There are resident populations further south, for example in southern India and Sri Lanka, so both visiting migrants and the in the vicinity reproduction subspecies take place in these areas in winter.

This species is typically originated in thick forests and other well-wooded habitats. Three or four eggs are laid in a cup shell in a tree.

The adult male Asian Paradise Flycatcher is about 20 cm long, but the long tail streamers double this. It has a black crested head, stale joke upperparts and pale grey underparts.

By their second year, the males of the wandering Indian race T. p. paradisi begin to obtain white feathers. By the third year, the male plumage is totally white, other than the black head. Males of the sedentary Sri Lankan race T. p. ceylonensis are forever stale joke.

The female of all races resembles the stale joke male, but has a grey throat, minor peak and lacks the tail streamers.

Wednesday, September 05, 2007

Salad

Salad is a light meal — or, as part of a larger meal, much more of an taster — consisting of mixed vegetables (usually including at least one leaf vegetable) or fruit, frequently with a dressing or sauce, occasionally nuts and sometimes with the addition of meat, fish or cheese. It is generally seen as a healthy dish, although not always low in calories, salt, sugar, or fat because of the dressing that is often added.The word "salad" comes from the French salade of the same meaning, which in twist is from the Latin salata, "salty", from sal, "salt".

Tuesday, August 21, 2007

Mainframes

Mainframes (often colloquially referred to as big iron) are huge and expensive computers used mainly by government institutions and large companies for mission critical applications, usually bulk data processing such as censuses, industry/consumer statistics, ERP, and financial transaction processing.
The term originated during the early 1970s with the introduction of smaller, fewer complex computers such as the DEC PDP-8 and PDP-11 series, which became known as minicomputers or just minis. The industry/users then coined the term "mainframe" to describe bigger, earlier types (previously known simply as "computers").

Monday, August 13, 2007

Lighthouse of Alexandria

The Pharos of Alexandria was a big tower built in the 3rd century BC (between 285 and 247 BC) on the island of Pharos in Alexandria, Egypt to give out as that port's landmark, and later, its lighthouse.

With a height variously estimated at between 115 and 150 meters (383 - 450 ft) it was among the tallest man-made structures on Earth for many centuries, and was recognized as one of the Seven Wonders of the World by Antipater of Sidon. It was the third tallest building after the two Great Pyramids (of Khufu and Khafra) for its whole life. Some scientists approximate a much taller height exceeding 180 metres that would make the tower the tallest building up to the 14th century.

Monday, July 30, 2007

Traffic light

A traffic light or traffic signal is a signalling device positioned at a road junction or pedestrian crossing to indicate when it is safe to drive, ride or walk, using a universal color code.Traffic lights for usual vehicles or pedestrians always have two main lights, a red one that means stop and a green one that means go. Generally, the red light contains some orange in its hue, and the green light contains some blue, to provide some support for people with red-green color blindness. In most countries there is also a yellow (or amber) light, which when on and not flashing means stop if able to do so securely. In some systems, a flashing amber means that a motorist may go in advance with care if the road is clear, giving way to pedestrians and to other road vehicles that may have precedence. A flashing red effectively means the same as a regular stop sign. There may be additional lights (usually a green arrow or "filter") to allow turns (called a lead light in the U.S., because it is usually leading the main green light).

Sunday, July 22, 2007

Vegetable

Vegetable is a culinary term which usually refers to an edible part of a plant. The definition is traditional rather than scientific and is somewhat capricious and subjective. All parts of herbaceous plants eaten as food by humans, entire or in part, are normally considered vegetables. Mushrooms, though belonging to the biological realm fungi, are also commonly considered vegetables. In general, vegetables are thought of as being savory, and not sweet, even though there are many exceptions. Nuts, grains, herbs, spices and culinary fruits (see below) are usually not considered vegetables.

Sunday, July 15, 2007

Asia

Asia is the world's biggest and most populous continent. It covers 8.6% of the Earth's total surface area (or 29.4% of its land area) and, with almost 4 billion people, it contains more than 60% of the world's present human population.

Chiefly in the eastern and northern hemispheres, Asia is conventionally defined as part of the landmass of Africa-Eurasia – with the western portion of the latter occupied by Europe – lying east of the Suez Canal, east of the Ural Mountains, and south of the Caucasus Mountains and the Caspian and Black Seas. It is surrounded to the east by the Pacific Ocean, to the south by the Indian Ocean, and to the north by the Arctic Ocean.

Given its size and diversity, Asia – a toponym dating back to classical antiquity – is more a cultural concept incorporating a number of regions and peoples than a homogeneous, physical entity.

Monday, July 09, 2007

Management information system

Management Information Systems (MIS) is a general name for the educational discipline casing the application of people, technologies, and procedures —together called information systems — to solve business problems. MIS are distinctive from normal information systems in that they are used to evaluate other information systems applied in operational activities in the organization. Rationally, the term is commonly used to refer to the group of information management methods attached to the automation or support of human decision making, e.g. Decision Support Systems, Expert systems, and Executive information system

Thursday, July 05, 2007

Accumulator

In a computer CPU, an accumulator is a register in which intermediary arithmetic and logic results are stored. Without a register like an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to main memory, possibly only to be read right back again for use in the next operation. Access to main memory is slower than access to a register like the accumulator because the technology used for the huge main memory is slower (but cheaper) than that used for a register.

The canonical example for accumulator use is adding a list of numbers. The accumulator is initially set to zero, then each number in spin is added to the value in the accumulator. Only when all numbers have been added is the result seized in the accumulator written to main memory or to another, non-accumulator, CPU register.

Sunday, July 01, 2007

Shark

Sharks are fish with a full cartilaginous skeleton and a streamlined body. They respire with the use of five to seven gill slits. Sharks have a covering of dermal denticles to protect their skin from injure and parasites and to improve fluid dynamics; they also have replaceable teeth.Sharks include species ranging from the hand-sized pygmy shark, Euprotomicrus bispinatus, a deep sea class of only 22 centimetres (9 in) in length, to the whale shark, Rhincodon typus, the largest fish, which grows to a length of about 12 metres (39 ft) and which, like the great whales, feeds only on plankton through filter feeding. The bull shark, Carcharhinus leucas, is the best known of several species to swim in both salt and fresh water and in deltas.

Wednesday, June 27, 2007

Superscalar

A superscalar CPU architecture implements a form of parallelism called Instruction-level parallelism within a solitary processor. It thereby allows faster CPU throughput than would otherwise be possible at the same clock rate. A superscalar architecture executes more than one instruction during a single pipeline stage by pre-fetching several instructions and at the same time dispatching them to redundant functional units on the processor.

History

Seymour Cray's CDC 6600 from 1965 is often mentioned as the first superscalar plan. The Intel i960CA and the AMD 29000-series 29050 microprocessors were the first commercial single-chip superscalar microprocessors. RISC CPUs like these brought the superscalar idea to micro computers because the RISC design results in a simple core, allowing straightforward instruction send off and the inclusion of multiple functional units on a single CPU in the inhibited design rules of the time. This was the reason that RISC designs were faster than CISC designs through the 1980s and into the 1990s.

Sunday, June 24, 2007

Neem oil

Neem oil is a vegetable oil pressed from the fruits and seeds of Neem, an evergreen tree which is endemic to the Indian sub-continent and has been introduced to many other areas in the tropics. It is perhaps the most significant of the commercially available products of neem.
Neem oil is typically light to dark brown, bitter and has a rather strong odour that is said to join the odours of peanut and garlic. It comprises mainly triglycerides and large amounts of triterpenoid compounds, which are in charge for the bitter taste. It is hydrophobic in nature and in order to emulisify it in water for application purposes, it must be formulated with suitable surfactants.
Neem oil also contains steroids and a plethora of triterpenoids of which Azadirachtin is the most well known and studied. The Azadirachtin content of Neem Oil varies from 300ppm to over 2000ppm depending on the quality of the neem seeds compressed.

Tuesday, June 19, 2007

Swan

Swans are large water birds of the family Anatidae, which also includes geese and ducks. Swans are grouped with the intimately related geese in the subfamily Anserinae where they form the tribe Cygnini. Sometimes, they are considered a distinct subfamily, Cygninae.

Swans typically mate for life, though "divorce" does sometimes occur, mainly following nesting failure. The number of eggs in each clutch is between 3–8.
The word is derived from Old English swan, akin to German Schwan, in turn derived from Indo-European root *swen (to sound, to sing), whence Latin derives sonus (sound). Young swans are known as cygnets, from the Latin word for swan, cygnus. An adult male is a cob, from Middle English cobbe; an adult female is a pen .

Friday, June 15, 2007

Tide

Tides are the cyclic rising and falling of Earth's ocean surface caused by the tidal forces of the Moon and the sun acting on the oceans. Tides cause changes in the depth of the marine and estuarine water bodies and produce oscillating currents known as tidal streams, making prediction of tides important for coastal navigation. The strip of seashore that is submerged at high tide and exposed at low tide, the intertidal zone, is an important ecological product of ocean tides The changing tide produced at a given location is the result of the changing positions of the Moon and Sun relative to the Earth coupled with the effects of Earth rotation and the local bathymetry.Sea level measured by coastal tide gauges may also be strongly affected by wind. More generally, tidal phenomena can occur in other systems besides the ocean, whenever a gravitational field that varies in time and space is present

Monday, June 11, 2007

Shrimp fishery

A shrimp fishery is a fishery directed toward harvesting either shrimp or prawns. Fisheries do not usually differentiate between the two taxa, and the terms are used interchangeably. This article therefore refers to the catching of either shrimp or prawns.

A number of the larger species, including the Atlantic white shrimp (Penaeus setiferus), are caught commercially and used for food. Recipes utilizing shrimp form part of the cuisine of many cultures: examples include jambalaya, okonomiyaki, poon choi, bagoong, Kerala and scampi.
Preparing shrimp for consumption usually involves removing the shell, tail, and "sand vein". As with other seafood, shrimp is high in calcium, protein and low in food energy.
Shrimp and prawns are versatile ingredients, and are often used as an accompaniment to fried rice. Common methods of preparation comprise baking, boiling and frying. As stated in the movie Forrest Gump

Thursday, June 07, 2007

Rose

A rose is a flowering shrub of the genus Rosa, and the flower of this shrub. There are more than a hundred classes of wild roses, all from the northern hemisphere and typically from temperate regions. The species form a group of normally prickly shrubs or climbers, and sometimes trailing plants, reaching 2–5 m tall, hardly ever reaching as high as 20 m by climbing over other plants.
Rose hips are sometimes eaten, mostly for their vitamin C content. They are typically pressed and filtered to make rose-hip syrup, as the fine hairs surrounding the seeds are unpleasant to eat. They can also be used to create herbal tea, jam, jelly and marmalade.

Friday, June 01, 2007

Industrial metal

Industrial metal is a musical genre which draws elements from industrial music and heavy metal music. Industrial metal music is typically centered around metal guitar riffs and industrial synthesizer/sequencer lines, heavily distorted, very low pitched guitars, as well as harsh vocals, but in some instances can have clean vocals. This term is used quite loosely, telling everything from industrial bands sampling metal riffs to heavy metal groups augmented with sequencers. Industrial metal encompasses industrial subgenres such as aggro-industrial and coldwave and often overlaps some elements of nu-metal and post-punk.

It is difficult to distinguish many industrial metal artists and industrial rock because both genres leave much room for ingenuity and creativity. By convention, all industrial metal artists may be more vaguely described as industrial rock as well, but not all industrial rock artists are properly described as industrial metal. The general rule of thumb is the speed and "crunchiness" of the guitars. If the guitars are fast and heavily distorted, it is likely industrial metal.

Monday, May 28, 2007

Genetics

Genetics is the science of heredity and variation in living organisms.Knowledge that desired characteristics were present at birth has been implicitly used since prehistoric times for improving crop plants and animals through selective breeding. However, the modern science of genetics, which seeks to understand the mechanisms of inheritance, only began with the work of Gregor Mendel in the mid-1800s.

Mendel observed that inheritance is basically a discrete process with specific traits that are inherited in an independant manner. These basic units of inheritance is now known as "genes". In the cells of organisms, genes exist actually in the structure of the molecule DNA and the information genes contain is used to create and control the components of cells. Although genetics plays a large role in determining the appearance and behavior of organisms, it is the interaction of genetics with the environment an organism experiences that determines the ultimate outcome. For example, while genes play a role in determining a person's height, the nutrition and health that person experiences in childhood also have a large effect.

Thursday, May 24, 2007

Mental health

Mental health is a idea that refers to a human individual's emotional and psychological well-being. Merriam-Webster defines mental health as "A state of emotional and psychological well-being in which an individual is able to use his or her cognitive and emotional capabilities, function in society, and meet the ordinary demands of everyday life."

According to the World Health Organization (WHO), there is no one "official" definition of mental health. Cultural differences, subjective assessments, and competing professional theories all affect how "mental health" is defined. In general, most experts agree that "mental health" and "mental illness" are not opposites. In other words, the absence of a recognized mental disorder is not of necessity an indicator of mental health.
One way to think about mental health is by looking at how efficiently and successfully a person functions. Feeling capable and competent; being able to handle normal levels of stress, preserve satisfying relationships, and lead an independent life; and being able to "bounce back," or recover from difficult situations, are all signs of mental health.
Encompassing your emotional, social, and—most importantly—your mental well-being; All these aspects—emotional, physical, and social—must function jointly to achieve overall health.

Sunday, May 20, 2007

Refrigerator

A typical refrigerator with its door open refrigerator is a cooling machine comprising a thermally insulated compartment and a mechanism to transfer heat from it to the outside environment, cooling the contents to a temperature below ambient. Refrigerators are widely used to store foods which deteriorate at ambient temperatures; spoilage due to bacterial growth and other processes is much slower at low temperatures. Devices described as "refrigerators" maintain a temperature a few degrees above the freezing point of water; similar devices which maintain temperatures below the freezing point of water are called "freezers". The refrigerator is a relatively modern creation amongst kitchen appliances. It replaced the common icebox which had been a household item for almost a century and a half prior, and is sometimes still called by the original name "icebox".

Tuesday, May 15, 2007

Color Television

100 Most television researchers respected the value of color image transmission, with an early patent application in Russia in 1889 for a mechanically-scanned color system showing how early the import of color was realized. John Logie Baird established the world's first color transmission on July 3, 1928, using scanning discs at the transmitting and receiving ends with three spirals of apertures, each spiral with filters of a different primary color; and three light sources at the receiving end, with a commentator to exchange their illumination.

Color television in the United States had a prolonged history due to incompatible technical systems vying for approval by the Federal Communications Commission for commercial use. Mechanically scanned color television was established by Bell Laboratories in June 1929 using three complete systems of photoelectric cells, amplifiers, glow-tubes, and color filters, with a series of mirrors to place over the red, green, and blue images into one full color image.

In the electronically scanned era, the first color television exhibition was on February 5, 1940, when RCA privately showed to members of the FCC at the RCA plant in Camden, New Jersey, a television receiver producing images in color by electronic and optical means without moving device. CBS began non-broadcast color experiments using film as early as August 28, 1940, and live cameras by November 12. The CBS "field sequential" color system was partly mechanical, with a disc made of red, blue, and green filters revolving inside the television camera at 1,200 rpm, and a similar disc spinning in synchronization in front of the cathode ray tube inside the receiver set. The RCA "dot sequential" color system had no moving parts, using a series of diachronic mirrors to separate and direct red, green, and blue light from the subject through three separate lenses into three scanning tubes, and electronic switching that allowed the tubes to send their signals in rotation, dot by dot. These signals were sorted by a second switching device in the receiver set and sent to red, green, and blue picture tubes, and combined by a second set of diachronic mirrors into a full color image.

Friday, May 11, 2007

Key

A key is a device which is used to open a lock. It typically consists of a specially-shaped piece of flat metal, with cut notches (forming teeth), and/or milled grooves which fit the shape of the lock and can open the properly combinated lock by (usually) being turned in the lock housing. This portion of the key is referred to as the blade. The wider grip, referred to as the bow, is establish at the top of the key to facilitate turning. regularly, there are only a small number of keys which can work a certain lock. In some residential locks, all of the keys for a lock are given to the purchaser of the lock. Duplicates of the key can usually be made by anyone with the correct key blank and key machine. Some manufacturers assign an identification number to each lock and key combination. Knowing the identification number of such a lock allows a duplicate key to be made at certain places. Many residential keys are recognized by the key cuts stamped on the key bow.
Most people in modern society use keys on a daily basis, to secure their home, their vehicle, or to access their workplace, among other uses. Those that use a number of keys will typically place them on a ring or key chain, often with other items such as key fobs.

Monday, May 07, 2007

Ancient Tamil gods and goddesses

The religion of the ancient Tamils directly followed Hinduism.although persisting with its roots of nature worship. The most popular deity was Murugan, who has from a very early date been recognized with Karthikeya, the son of Siva. Muruga might have been a different deity at first stemming from a local deity. According to the noted expert on Tamil culture Kamil V. Zvelebil, "Subrahmanya-Murugan is one of the most complicated and baffling deities for analysis". The worship of Amman or Mariamman, consideration to have been derived from Kotravai, an ancient mother goddess, also was very common. Kannagi, the heroine of the Cilappatikaram, was worshipped as Pathini by many Tamils, particularly in Sri Lanka. There were also many temples and devotees of Thirumaal, Siva, Ganapathi, and the other common Hindu deities.

Wednesday, May 02, 2007

Traffic calming

Traffic reassuring is a set of strategies used by urban planners and traffic engineers which aims to slow down traffic and improve safety for pedestrians and bicyclists, although some of these features can also be dangerous to cyclists. It is now relatively common in Europe, especially Northern Europe; less so in North America.
Traffic calming has traditionally been justified on the grounds of pedestrian security and reduction of noise and local air pollution which are side effects of the traffic. However, it has become increasingly apparent that streets have many social and recreational functions which are severely impaired by fast car traffic. For example, residents of streets with light traffic had, on average, three more friends and twice as many acquaintances as the people on streets with heavy traffic which were otherwise similar in dimensions, income, etc. For much of the twentieth century, streets were designed by engineers who were charged only with ensuring traffic flow and not with fostering the other functions of streets. The rationale for traffic calming is now broadening to include designing for these functions.
Displaced traffic is not fully pushed onto other routes, as some travelers may begin to walk or use other modes such as public transit and bicycles to get where they are going. Still, in most cases the affected motorists have few alternatives aside from either navigating the newly erected obstacles or finding a more palatable route. This happens because high traffic tends to be generated by motorists passing through the area and not by the local residents.

It should be noted the some of these measures have a tendency to irritate and annoy drivers rather than calm them and others can actually increase traffic throughput. Some drivers who slow down at calming points, however, accelerate and speed after passing them in order to "catch up for lost time". For this reason, more advanced methods integrated into the design of the street, which make slower speeds seem more natural to drivers and less of an artificial imposition, are now preferred - the goal is to slow down the driver through psychological, at least partly subconscious means instead of simply forcing him to do so.

One major side effect of traffic reassuring is the impedance to emergency services. A police car can easily navigate most traffic reassuring measures. The same cannot be said for fire trucks and ambulances, however. They often have to slow down to safely cross speed bumps or chicanes. In some locales, the law prohibits traffic calming measures along the routes used by the urgent situation services.
There are 3 "E"'s that traffic engineers refer to when discussing traffic reassuring: engineering, education, and enforcement. Because neighborhood traffic management studies have shown that often it is the residents themselves that are largely contributing to the perceived speeding problem within the neighborhood, it is strained that the most effective traffic calming plans will entail all three components, and that engineering measures alone will not produce satisfactory results.

Sunday, April 29, 2007

Lightning

Lightning is an influential natural electrostatic release produced during a thunderstorm. Lightning's abrupt electric release is accompanied by the emission of visible light and other forms of electromagnetic radiation. The electric current passing through the release channels quickly heats and expands the air into plasma, producing acoustic shock waves in the atmosphere.

Early lightning investigate
During early investigations into electricity via Leyden jars and other instruments, a number of people planned that small scale sparks shared some similarity with lightning.

Benjamin Franklin, who also imaginary the lightning rod, endeavored to test this theory by using a spire which was being erected in Philadelphia. Whilst he was waiting for the spire completion some others conducted at Marly in France, what became to be known as the Philadelphia experiments that Franklin had optional in his book?

Franklin typically gets the credit for being the first to perform this research. The Franklin myth goes like this:

Whilst coming up for completion of the spire, he got the idea of using a flying object, such as a kite in its place. During the next shower, in June 1752, he raised a kite, accompanied by his son as an assistant. On his end of the string he emotionally involved a key and tied it to a post with a silk thread. As time passed Franklin noticed the loose fibers on the string stretching out; he then brought his hand close enough to the key and a flash jumped the gap. The rain which had fallen during the storm had covered with water the line and made it conductive.

However, in his memoirs, Franklin obviously states that he only performed this research after those made in France.

As news of the research and its specifics spread, it was met with attempts at duplication. Experiments involving lightning are always risky and commonly fatal. The most well known death during the rash of Franklin-imitators was Professor George Richman, of Saint Petersburg, Russia. He had shaped a setup similar to Franklin's, and was attending a meeting of the Academy of Sciences, when he heard thunder. He ran home with his engraver to capture the event for posterity. While the research was underway, a large ball lightning showed up, collided with Richman's head, and killed him, leaving a red spot. His shoes were blown open, parts of his clothes singed, the engraver knocked out, the doorframe of the room was split, and the door itself ragged off its hinges.

Monday, April 23, 2007

Northern Mockingbird

The Northern Mockingbird, Mimus polyglottos, is the mockingbird commonly originate in North America.Adults are grey on the head and upperparts with pale yellow eyes and a slim black bill with a slight downward curve; the underparts are light. They have a long dark tail by means of white edges and long dark legs. They have white wing bars and show white wing patches in flight.Their breeding habitat is areas with a mix of open areas and dense shrubs from southern Canada to Mexico, but is most common in the southern United States. They build a twig nest in a dense shrub or tree. This bird forcefully defends its nest against other birds and animals, including humans. When a predator is persistent mockingbirds from adjacent territories, summoned by a distinct call, may join the attack. Other birds may gather to watch as the mockingbirds harass the intruder.
They are usually permanent residents; northern birds may move south during harsh weather. However, this species has occurred in Europe as an extreme rarity.These birds forage on the ground or in vegetation; they also fly down from a perch to capture food. They mainly eat insects and berries. While foraging they will regularly spread their wings in a peculiar two-step motion to display the white patches underneath. The purpose of this behavior is disputed. Some ornithologists claim this is merely a territorial display, while others say that flashing the white patches startles hiding insects and forces them into the open. Both theories seem to have some merit.
This bird imitates the calls of other birds, animal sounds and yet machine noises. It is often found in urban areas. They often call through the night and may continue year-round apart from for the summer moulting season. Mockingbirds usually sing the loudest in the twilight of the early morning when the sun is on the horizon. While singing on a high perch they will often bolt more than a few feet into the air in a looping motion, with wings outstretched to display their white underside, then land back on the perch without breaking a note. That serves as a territorial display.Mockingbirds have a strong preference for certain trees, such as maple, sweet gum (green 5-pointed leaves and prickly porous balls), and sycamore. They normally avoid pine trees. In urban areas, mockingbirds rarely come down to the ground, unlike most birds. Also, they have a particular preference for high places, such as the topmost branches of trees and the tops of telephone poles.

Wednesday, April 18, 2007

Motorcycle racing

There are a range of sports involving racing motorcycles. FIM is the international sanctioning body for many such events.As motorcycles vary very much in design, there are several different types of motorcycle racing contest, including:Road racing in its purest form is racing on public roads, such as the Isle of Man TT course, the Macau Grand Prix and some courses in Ireland. Due to the inherent dangers that these street venues often carry such as narrow lanes, curbs, and adjacent walls, most road racing is now carried out on purpose-built tracks.Circuit racing where specially designed racing bikes or modified "production" bikes race each other on particularly designed road circuits. MotoGP and Superbike are the top level racing and production classes.Classic Racing is where participants race heavily customized bikes from an earlier era - usually pre mid '70s bikes.
Motocross and its cousin supercross are held on dirt courses, characteristically featuring large jumps in which motorcycles are launched over considerable distances. Supermoto is a crossover motorcycle racing between road racing and motocross. The motorcycles are primarily motocross types with road racing tires. The racetrack is also mixed between road and dirt courses, mostly handcrafted.
Motorcycle speedway and ice speedway are held on oval circuits where riders slide their machines around turns.

Monday, April 09, 2007

Radio

Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of light.
Radio waves.Radio waves are a form of electromagnetic radiation, formed whenever a charged object accelerates by a frequency that lies in the radio frequency (RF) portion of the electromagnetic spectrum. This is the variety from a few tens of hertz to a few hundred gigahertz.Electromagnetic radio spectrum
Other types of electromagnetic radiation, with frequencies above the RF range are infrared, visible light, ultraviolet, X-rays and gamma rays. Since the energy of an individual photon of radio frequency is too low to remove an electron from an atom, radio waves are classified as non-ionizing radiation.Radio transmission diagram and electromagnetic waves.Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space equally well, and does not need a medium of transport induces an alternating current and voltage in the conductor. This can be transformed into audio or other signals that carry information. Although the word 'radio' is used to explain this phenomenon, the transmissions which we know as television, radio, radar, and cell phone are all classed as radio frequency emissions.

Thursday, April 05, 2007

Transistor

The transistor is a solid state semiconductor device which can be used for amplification, switching, voltage stabilization, signal modulation and many other functions. It acts as a changeable valve which, based on its input current (BJT) or input voltage (FET), allows a precise amount of current to flow through it from the circuit's voltage supply.In essence, a transistor has three terminals. A current or voltage applied through/across two terminals controls a larger current through the other terminal and the common terminal. In analog circuits, transistors are used in amplifiers. Analog circuits include audio amplifiers, stabilised power supplies and radio frequency amplifiers. In digital circuits, transistors function basically as electrical switches. Digital circuits include logic gates, RAM (random access memory) and microprocessors.Transistor was also the common name in the sixties for a transistor radio, a portable radio that used transistors (rather than vacuum tubes) as its active electronic components. This is still one of the dictionary definitions of transistor.

Sunday, April 01, 2007

Sugarcane

Sugarcane or Sugar cane (Saccharum) is a type of between 6–37 species of tall grasses (family Poaceae, tribe Andropogoneae), native to warm temperate to tropical regions of the Old World. They have stout, jointed fibrous stalks 2–6 m tall and sap rich in sugar. All the species interbreed, and the major commercial cultivars are complex hybrids.
Saccharum officinarum grown in Hawaii. There are 13 million hectares (32 million acres) of sugar cane plantations worldwide, with over 100 countries growing the crop. The top twenty producing countries harvested 1200 million metric tons of sugar cane in 2002 (more than 6 times the amount of sugar beet produced). The largest producers are Brazil, India, and China.
Raw sugar has a yellow to brown color. If a white product is preferred, sulfur dioxide may be bubbled through the cane juice prior to evaporation. This bleaches many color-forming impurities into colorless ones. Sugar bleached white by this sulfitation process is called mill white, plantation white or crystal sugar. This form of sugar is the most usually consumed form of sugar in sugarcane-producing countries.