Sunday, March 30, 2008

Computer printer

A computer printer, or more normally a printer, produces a hard copy (permanent human-readable text and/or graphics) of documents stored in electronic form, frequently on physical print media such as paper or transparencies. Many printers are mostly used as local computer peripherals, and are attached by a printer cable to a computer which serves as a document source. Some printers, commonly known as network printers, have built-in network interface (typically wireless or Ethernet), and can serve as a hardcopy device for any user on the network. Individual printers are frequently intended to support both local and network connected users at the same time.

In addition, many modern printers can directly interface to electronic media such as memory sticks or memory cards, or to image capture devices such as digital cameras, scanners; a number of printers are combined with a scanners and/or fax machines in a single unit. Printers that contain non-printing features are sometimes called Multifunction Printers (MFP) or Multi-Function Devices (MFD).

Sunday, March 23, 2008

Pulses

Pulses are defined by the Food and Agricultural Organization of the United Nations (FAO) as yearly leguminous crops yielding from one to twelve grains or seeds of variable size, shape and color surrounded by a pod. Pulses being used for food and animal feed.

The term pulses, as used by the FAO, are kept for crops harvested solely for the dry grain. This therefore excludes green beans and green peas, which are measured vegetable crops. Also barred crops which are mainly grown for oil extraction oilseeds like soybeans and peanuts, and crops which are used exclusively for sowing (clovers, alfalfa).

Pulses are main food crops due to their high protein and necessary amino acid content. Like many leguminous crops, pulses play a key role in crop turning round due to their capability to fix nitrogen.

Sunday, March 16, 2008

Salwar kameez

Salwar kameez is also spelled shalwar kameez and shalwar qamiz is a customary dress worn by both women and men in Pakistan, India, Bangladesh, and Afghanistan. It is now and then known as Punjabi suit owing to its popularity in the Punjab region and the Pathani suit, due to the fact that the Pathans of Kabul set up the dress to the rest of South Asia.

It is loose pajama like trousers the legs are wide at the top and thin at the bottom,
The kameez is a long shirt or tunic. The part seams known as the chaak are left open under the waist-line, which gives the wearer greater freedom of movement. In Afghanistan and Pakistan, it is the special garment of both sexes. In Bangladesh and India, it is usually a woman's garment though the majority of Indian women wear traditional clothing, the men in India can be found in more comfortable in western clothing. Shalwar kameez is the traditional dress worn by a many peoples of south-central Asia. In India and Pakistan it is a largely popular style of dress, Shalwar or Salwar is a short loose or parallel trouser.

Sunday, March 09, 2008

Fixed income

Fixed income refers to any kind of investment that yields a normal or fixed return.
For example, if you create use of money and have to pay interest once a month, you have issue a fixed-income security. When a company does this, it is frequently called a bond or corporate bank debt even though 'preferred stock' is also sometimes measured to be fixed income. Sometimes people misspeak when they talk about fixed income; bonds really have higher risk, while notes and bills have less risk because these are issued by Government agencies.

The term fixed income is also useful to a person's income that does not differ with each period. This can include income derivative from fixed-income investments such as bonds and preferred stocks or pensions that guarantee a fixed income.

Monday, March 03, 2008

Planet

A planet, as defined by the International Astronomical Union (IAU), is a celestial body orbiting a star or stellar remnant that is enormous enough to be rounded by its own gravity, not massive enough to cause thermonuclear fusion, and has cleared its neighboring region of planetesimals.

The term planet is an antique one having ties to history, science, myth, and religion. The planets were originally seen as a divine attendance; as emissaries of the gods. Even today, many people continue to believe the movement of the planets affects their lives, although such causation is rejected by the scientific community. As scientific knowledge advanced, the human awareness of the planets changed over time, incorporating a number of disparate objects. Even now there is no recognized definition of what a planet is. In 2006, the IAU formally adopted a resolution defining planets within the Solar System. This definition has been both praised and criticize, and remains disputed by some scientists.

Under IAU definitions, there are eight planets in the Solar System (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune) and 270 further solar ones. The Solar System also contains at slightest three dwarf planets (Ceres, Pluto, and Eris). Many of these planets are orbited by one or more moons, which can be superior than small planets. Planets are usually divided into two main types: large, low-density gas giants and smaller, rocky terrestrials.

Wednesday, February 27, 2008

Solar tracker

A solar tracker is a device for orienting a solar photovoltaic panel or concentrating solar reflector or lens toward the sun. Concentrators, especially in solar cell applications, require a high degree of accuracy to ensure that the concentrated sunlight is directed precisely to the powered device, which is at (or near) the focal point of the reflector or lens. Non-concentrating applications require less accuracy, and a tracker is not necessary, but can substantially improve the amount of power produced by a system by enhancing morning and afternoon performance.

Friday, February 22, 2008

Plesiosaur

Plesiosaurs(Greek: plesios meaning 'near' or 'close to' and sauros meaning 'lizard') were carnivorous aquatic (mostly marine) reptiles. After their discovery, they were somewhat fancifully said to have resembled "a snake threaded through the shell of a turtle", although they had no shell. The common name 'plesiosaur' is applied both to the 'true' plesiosaurs (Suborder Plesiosauroidea) and to the larger taxonomic rank of Plesiosauria, which includes both long-necked (elasmosaurs) and short-necked (polycotylid) forms. Short-necked, large-headed plesiosaurs are more properly called pliosaurs. There were many species of plesiosaurs and not all of them were as large as Liopleurodon, Kronosaurus or Elasmosaurus.

Sunday, February 17, 2008

Proportional control

When controlling the temperature of an industrial furnace, it is usually better to control the opening of the fuel valve in proportion to the current needs of the furnace. This helps avoid thermal shocks and applies heat more effectively.

Proportional negative-feedback systems are based on the difference between the required set point (SP) and measured value (MV) of the controlled variable. This difference is called the error. Power is applied in direct proportion to the current measured error, in the correct sense so as to tend to reduce the error (and so avoid positive feedback). The amount of corrective action that is applied for a given error is set by the gain or sensitivity of the control system.

Friday, February 08, 2008

Living systems theory

Living systems theory is an offshoot of Bertalanffy's general systems theory, created by James Grier Miller, which was intended to formalize the concept of "life". According to Miller's original conception as spelled out in his magnum opus Living Systems, a "living system" must contain each of 20 "critical subsystems", which are defined by their functions and visible in numerous systems, from simple cells to organisms, countries, and societies. In Living Systems Miller provides a detailed look at a number of systems in order of increasing size, and identifies his subsystems in each.

James Grier Miller (1978) wrote a 1,102-page volume to present his living systems theory. He constructed a general theory of living systems by focusing on concrete systems—nonrandom accumulations of matter-energy in physical space-time organized into interacting, interrelated subsystems or components. Slightly revising the original model a dozen years later, he distinguished eight “nested” hierarchical levels in such complex structures. Each level is “nested” in the sense that each higher level contains the next lower level in a nested fashion.

Sunday, January 27, 2008

Classical Marxism

Classical Marxism refers to the body of theory directly expounded by Karl Marx and Friedrich Engels. The term "Classical Marxism" is often used to distinguish between "Marxism" as it is broadly understood and "what Marx believed", which is not necessarily the same thing. For example, shortly before he died in 1883, Marx wrote a letter to the French workers' leader Jules Guesde and to his own son-in-law Paul Lafargue, both of whom claimed to represent Marxist principles, in which he accused them of "revolutionary phrase-mongering" and of denying the value of reformist struggles. Paraphrasing Marx: "If that is Marxism, then I am not a Marxist". As the American Marx scholar Hal Draper remarked, "there are few thinkers in modern history whose thought has been so badly misrepresented, by Marxists and anti-Marxists alike."

Thursday, January 17, 2008

Nuclear transport

The entry and exit of large molecules from the nucleus is tightly controlled by the nuclear pore complexes. Although small molecules can enter the nucleus without regulation, macromolecules such as RNA and proteins require association karyopherins called importins to enter the nucleus and exportins to exit. "Cargo" proteins that must be translocated from the cytoplasm to the nucleus contain short amino acid sequences known as nuclear localization signals which are bound by importins, while those transported from the nucleus to the cytoplasm carry nuclear export signals bound by exportins. The ability of importins and exportins to transport their cargo is regulated by GTPases, enzymes that hydrolyze the molecule guanosine triphosphate to release energy. The key GTPase in nuclear transport is Ran, which can bind either GTP or GDP (guanosine diphosphate) depending on whether it is located in the nucleus or the cytoplasm.

Thursday, January 10, 2008

Comparative psychology

Comparative psychology refers to the study of the behavior and mental life of animals other than human beings. It is related to disciplines outside of psychology that study animal behavior, such as ethology. Although the field of psychology is primarily concerned with humans, the behavior and mental processes of animals is also an important part of psychological research, either as a subject in its own right (e.g., animal cognition and ethology), or with strong emphasis about evolutionary links, and somewhat more controversially, as a way of gaining an insight into human psychology by means of comparison or via animal models of emotional and behavior systems as seen in neuroscience of psychology .

Friday, January 04, 2008

Cosmology

Cosmology is the branch of metaphysics that deals with the world as the totality of all phenomena in space and time. Historically, it has had quite a broad scope, and in many cases was founded in religion. The ancient Greeks did not draw a distinction between this use and their model for the cosmos. However, in modern use it addresses questions about the Universe which are beyond the scope of physical science. It is distinguished from religious cosmology in that it approaches these questions using philosophical methods (e.g. dialectics). Cosmogony deals specifically with the origin of the universe.

Friday, December 28, 2007

Robotics

Robotics is the science and technology of robots, their design, manufacture, and application. Robotics requires a working knowledge of electronics, mechanics, and software. A person working in the field is a roboticist. The word robotics was first used in print by Isaac Asimov, in his science fiction short story "Runaround" (1941).

A robot is an electro-mechanical or bio-mechanical device that can perform autonomous or preprogrammed tasks. Robots may be used to perform tasks that are too dangerous or difficult for humans, such as radioactive waste clean-up, or may be used to automate mindless repetitive tasks that should be performed with more precision by a robot than by a human, such as automobile production.

Wednesday, December 19, 2007

Networking and the Internet

Computers have been used to coordinate information in multiple locations since the 1950s, with the U.S. military's SAGE system the first large-scale example of such a system, which led to a number of special-purpose commercial systems like Sabre.

In the 1970s, computer engineers at research institutions throughout the United States began to link their computers together using telecommunications technology. This effort was funded by ARPA (now DARPA), and the computer network that it produced was called the ARPANET. The technologies that made the Arpanet possible spread and evolved. In time, the network spread beyond academic and military institutions and became known as the Internet. The emergence of networking involved a redefinition of the nature and boundaries of the computer. Computer operating systems and applications were modified to include the ability to define and access the resources of other computers on the network, such as peripheral devices, stored information, and the like, as extensions of the resources of an individual computer.

Wednesday, December 12, 2007

Nanotechnology

Nanotechnology refers broadly to a field of applied science and technology whose unifying theme is the control of matter on the atomic and molecular scale, normally 1 to 100 nanometers, and the fabrication of devices within that size range. It is a highly multidisciplinary field, drawing from fields such as applied physics, materials science, interface and colloid science, device physics, supramolecular chemistry, chemical engineering, mechanical engineering, and electrical engineering. Much speculation exists as to what may result from these lines of research. Nanotechnology can be seen as an extension of existing sciences into the nanoscale, or as a recasting of existing sciences using a newer, more modern term.

Two main approaches are used in nanotechnology. In the "bottom-up" approach, materials and devices are built from molecular components which assemble themselves chemically by principles of molecular recognition. In the "top-down" approach, nano-objects are constructed from larger entities without atomic-level control. The impetus for nanotechnology comes from a renewed interest in Interface and Colloid Science, coupled with a new generation of analytical tools such as the atomic force microscope (AFM), and the scanning tunneling microscope (STM). Combined with refined processes such as electron beam lithography and molecular beam epitaxy, these instruments allow the deliberate manipulation of nanostructures, and led to the observation of novel phenomena.

Thursday, December 06, 2007

Cellular network

A cellular network is a radio network made up of a number of radio cells (or just cells) each served by a fixed transmitter, known as a cell site or base station. These cells are used to cover different areas in order to provide radio coverage over a wider area than the area of one cell. Cellular networks are inherently asymmetric with a set of fixed main transceivers each serving a cell and a set of distributed (generally, but not always, mobile) transceivers which provide services to the network's users.

Cellular networks offer a number of advantages over alternative solutions:

* increased capacity
* reduced power usage
* better coverage

A good (and simple) example of a cellular system is an old taxi driver's radio system where the taxi company will have several transmitters based around a city each operated by an individual operator.

Wednesday, November 28, 2007

What is Java Virtual Machine?

The heart of the Java Platform is the concept of a "virtual machine" that carries out Java bytecode programs. This bytecode is the same despite what hardware or operating system the program is running under. There is a JIT (just-in-time compilation) compiler inside the Java Virtual Machine, or JVM. The JIT compiler converts the Java bytecode into native processor instructions at run-time and caches the native code in memory during the tome of the execution.

The use of bytecode as an intermediary language that allows Java programs to run on any platform that has a virtual machine accessible. The use of a JIT compiler means that the applications in Java, after a small delay throughout loading and once they have "warmed up" by being all or mostly JIT-compiled, tend to run about as speed as native programs. Because JRE version 1.2, Sun's JVM execution has included a just-in-time compiler as an alternative of an interpreter.

Wednesday, November 21, 2007

Difference between C and C++ programming language

This C language was the C++ predecessor. Even though not actually being more powerful than C, C++ lets the programmers to more easily deal with and operate with Objects, using an OOP (Object Oriented Programming) concept.

The C++ allows the programmer to create classes, which are a bit alike to C structures. Although it is possible to apply anything which C++ could implement in C, C++ aids to standardize a means in which objects are created and managed, whereas the C programmer who implements the same system has alot of liberty on how to really implement the internals, and the style among programmers will differ alot on the design choices made in a program.

In C, some will choose the handler-type, where a main function initializes a handler, and that handler can be provided to other functions of the library as an object to manage on/through. Others will even want to have that handler link all the associated function pointers within it which then must be called using a convention closer to C++.

Wednesday, November 14, 2007

A short note on the history of Honda

The Honda VTR1000F is a motorcycle invented by Honda. In 1997 Honda started producing a street-oriented GT motorcycle using a traditionally important name: Superhawk. The earlier (60's) Superhawk was a parallel twin motorcycle that Robert M. Pirsig rode in "Zen and the Art of Motorcycle Maintenance". The original Superhawk was a profitable success, that's why the name is being recycled. The latest Superhawk was introduced after the Ducati 916 made V-twin sport bikes well-liked again. The new Superhawk uses an all new 90 degree V-twin. The bike introduced numerous new design concepts for example the "pivotless frame", side radiators, single casting engine case, involving rods with cap screws rather than nuts, and the biggest carburetors Honda ever put on a motorcycle. "Pivotless frame" intended that engine was a stressed member with the swing arm bolted straightforwardly to the engine. The bike was come into public in 1997 as an early release 1998 model year. One motorcycle magazine recommended (circa 2000) that this bike was the fastest 0-60 mph production bike at that time. A racing version of the bike was anticipated from Honda. The Honda produced in 2000 the RVT1000R (RC51) recognized outside the United States as the VTR1000SP, though the bike had only four engine parts in general with the modern Superhawk. The RC51 was completely new V-twin racing platform that won the World Superbike championship its first year racing with the Colin Edwards and Castrol team.