Tuesday, February 26, 2008

Pollutants in water

Pollutants in water consist of a huge spectrum of chemicals, pathogens, and physical chemistry or sensory changes.Various chemical substances are toxic. Pathogens can actually create waterborne diseases in either human or animal hosts. Alteration of water’s physical chemistry contains acidity, conductivity, temperature, and eutrophication. Eutrophication is the fertilization of surface water by nutrients that were before scarce. Even a lot of the municipal water supplies in developed countries can present health risks.

Sunday, February 17, 2008

Operating System

An operating system (OS) is a colection of computer programs that manage the hardware and software resources of a computer.An operating system processes unprocessed system and user input and responds by allocating and managing tasks and interior system resources as a service to users and programs of the system. At the establishment of all system software, an operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating networking and managing file systems. mainly operating systems come with an application that provides an interface to the OS managed resources. These applications have been command line interpreter as a basic user interface, but more recently have been implemented as a graphical user interface (GUI) for easiness of operation. Operating Systems themselves have no user interfaces, and the user of an OS is an application, not a person. The operating system forms a platform for other system software and for application software. Microsoft Windows, Linux, and Mac OS are some of the most popular OS's

Sunday, February 10, 2008


Nanotechnology is a pasture of applied science and technology covering a wide range of topics. The main unifying premise is the control of matter on a scale smaller than 1 micrometer, normally between 1-100 nanometers, as well as the manufacture of devices on this same length scale. It is a highly multidisciplinary field, drawing from fields such as colloidal science, device physics, and supramolecular chemistry. Much hypothesis exists as to what new science and technology might result from these lines of research. Some view nanotechnology as a marketing term that describes pre-existing lines of research applied to the sub-micron size scale.

In spite of the apparent ease of this definition, nanotechnology actually encompasses diverse lines of inquiry. Nanotechnology cuts across many disciplines, together with colloidal science, chemistry, applied physics, materials science, and even mechanical and electrical engineering. It could variously be seen as an extension of existing sciences into the nanoscale, or as a recasting of existing sciences using a newer, more recent term. Two major approaches are used in nanotechnology: one is a "bottom-up" approach where materials and devices are built from molecular components which gather themselves chemically using principles of molecular gratitude; the other being a "top-down" approach where nano-objects are constructed from larger entities without atomic-level control.