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Ultraviolet (UV) radiation is defined as that portion of the electromagnetic spectrum between x rays and visible light, i.e., between 40 and 400 nm (30–3 eV). The UV spectrum is divided into Vacuum UV (40-190 nm), Far UV (190-220 nm), UVC (220-290 nm), UVB (290-320), and UVA (320-400 nm). The sun is our primary natural source of UV radiation. Artificial sources include tanning booths, black lights, curing lamps, germicidal lamps, mercury vapor lamps, halogen lights, high-intensity discharge lamps, fluorescent and incandescent sources, and some types of lasers (excimer lasers, nitrogen lasers, and third harmonic Nd:YAG lasers). Unique hazards apply to the different sources depending on the wavelength range of the emitted UV radiation.
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infrared radiations lie within that part of the electromagnetic spectrumwhich gives rise to heating when absorbed by matter. Infrared radiations are those,whose wavelengths are longer than that of visible red light extending to the microwave region, i.e., from 760 nm to 1 mm
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The ability to transmit particles into the ablation region of an aerosol mass spectrometer determines in part the lower size limit for particles that can be analyzed. A large fraction of small particles (< 100 nm) are lost due to processes such as Brownian diffusion that broaden the particle beam. In this work, electrostatic focusing is used to overcome the limits of aerodynamic focusing in the analysis of nanometer-sized particles by aerosol mass spectrometry. A simple tube lens is used to focus charged particles into the ablation laser beam path. The diameter of the focused beam is smaller than the fundamental aerodynamic limit imposed by Brownian motion. Measured enhancements of the hit rate for particles between 21 and 33 nm diameter are between 3 and 6. These values are lower limits for the true enhancements. The lens is also energy selective and can be used to select the mass (size) of the particles being analyzed.
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If we break a magnet into two parts each parts become a magnet with a north pole at one end and a south pole at the other end. If we break it further, we observe the same behaviour. This will continue even if we break the magnet to its molecular level.
Each molecule of a magnetic substance is an independent magnet irrespective of whether the substance is magnetized or not. These tiny magnets are called molecular magnets.
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VIT is emerging as a benchmark for continuous journey
towards excellence, among the institutions of higher education
in the field of technology in the country. Its values of equality,
transparency and healthy collaboration have been ably guided by
the leadership of its founder Dr. G. Viswanathan, renowned
for his principled life devoted to public service.
The ubiquitous sense of joy and enthusiasm observed in
the campus bears testimony to the positive learning and living
experiences enjoyed by every student at VIT. Ours is a place
where opportunities for learning as well as recreation are
maximized and distractions are minimized.
VIT Students get to feel the taste of a boundary-less
world through a heterogeneous mixture of students from across
the globe, who have made VIT as their institution of choice.
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magnetic moment is equal to IA NOW WHEN IT IS BENT IN YHE FORM OF WIRE ITS CIRCUMFERENCE IS EOUAL MTO THE 2*3.14*Rand is equal to the L
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Radioactivity is the spontaneous emission of energy from unstable atoms. Atoms are found in all natural matter. There are stable atoms, which remain the same forever, and unstable atoms, which break down or 'decay' into new atoms. These unstable atoms are said to be 'radioactive', because they emit radioactivity from the nucleus as they decay.
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Humid air contains water droplets and make it conducting. Humid air defects static electricity experiments in two ways, (1) It reduces friction (2) It carries away the charges on rubbed bodies.
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The conversion of an acid catalyzed enol to the keto form proceeds by a two step mechanism in an aqueoua acidic solution.For this it is necessary that the alpha carbon(carbon closest to functional group) contains at least one hydrogen atom known as alpha hydrogen.This atom is removed from the alpha carbon and bonds to the oxygen of the carbonyl carbon to form the enol tautomer. The existence of hydrogen atom at alpha carbon is necessary but not sufficient condition for enolization to occur
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Making chloroform is a process that requires a mix of laboratory equipments chemicals and safety gear. Chloroform is a dangerous chemical that can cause terminal diseases and even death if it is not administered correctly. The chemical should always be treated with care and only handled with absolute knowledge and the proper precautions. While it is possible to make chloroform at home but, where possible, it should be carried out in a laboratory. Before beginning to make chloroform you will need to make sure that you have the following equipment; bleach, pure acetone, ice, glassware and a separation funnel. Once you have all of the necessary tool and are properly protected with good safety equipment,
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In physics, a parity transformation (also called parity inversion) is the flip in the sign of onespatial coordinate. In three dimensions, it is also commonly described by the simultaneous flip in the sign of all three spatial coordinates: 
It can also be thought of as a test for chirality of a phenomenon, in that performing a parity inversion transforms a phenomenon into its mirror image. A parity transformation on something achiral, on the other hand, can be viewed as an identity transformation.
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my question is the following:
we know from books on semiconductor physics that the energy levels of the electrons in a pure semiconductor cristal form in fact bands of energy.
I was wondering why these energy levels are in the form of bands an not simple distinct energy levels as the ones of a single atom for example.
In fact, what is the physical quantum system these energies are solution to?
Put in another way, what is the potential energy a single electron in the cristal is object to?
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The atmosphere shows variation in behavior for different . the stars present in our atmosphere are clearly visible to us. This is due to the visibleradiations. These radiations change the behavior of the atmosphere to trnsprent
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Common adulterants present in ghee and oil are paraffin wax, hydrocarbons, dyes and argemone oil. These are detected as follows : (i) Adulteration of paraffin wax and hydrocarbon in vegetable ghee
Heat small amount of vegetable ghee with acetic anhydride. Droplets
of oil floating on the surface of unused acetic anhydride indicates the
presence of wax or hydrocarbons. (ii) Adulteration of dyes in fat Heat 1mL of fat with a mixture of 1mL of conc. sulphuric acid and 4mL of acetic acid. Appearance of pink or red colour indicates presence of dye in fat. (iii) Adulteration of argemone oil in edible oils To small amount of oil in a test-tube, add few drops of conc. HNO3 and shake. Appearance of red colour in the acid layer indicates presence of argemone oil.
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The common system has naming convention for carbon chains as they relate to branching. - n-alkanes are linear
- iso-alkanes have one branch R2CH—
- neo-alkanes have two branches R3C—
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Davisson and Germer's actual objective was to study the surface of a piece of nickel by directing a beam of electrons at the surface and observing how many electrons bounced off at various angles. They expected that for electrons even the smoothest crystal surface would be too rough and so the electron beam would experience diffuse reflection
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one of the consequences of Einstein's special theory of relativity (1905) is that the mass of an object increases with its velocity relative to the observer. When an object is at rest (relative to the observer), it has the usual (inertial = tendency to resist an applied force) mass that we are all familiar with. This is called the 'rest mass' of the object.
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Relativistic quasifree approximations for inclusive scattering on a bound system are investigated. The system is described by means of the Bethe-Salpeter equation. It is shown that final state interaction (FSI) corrections to the relativistic West approximation (on-shell quasifree kinematics for the struck nucleon) are of the same order of magnitude as the quasifree term in the asymptotic limit q→∞. Therefore the on-shell approximation cannot be applied to data analysis
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Quantitized energy is demonstrated in the bright line spectra by the fact that specific, distinct, unique colors come from the excitation of the atoms of a sample of an element.
Quantitized energy means that the energy comes in parcels or packets like marbles but not as a continuously variable amount like string.
So, when an excited atom's electrons fall back into their normal orbit after being excited by outside energy, they give up a specific "packet" of energy or photon of aspecific energy (frequency) which shows up as a characteristic bright line on the spectrum.
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The value of a resistor changes with changing temperature, but this is not as we might expect, mainly due to a change in the dimensions of the component as it expands or contracts. It is due mainly to a change in the resistivity of the material caused by the changing activity of the atoms that make up the resistor. Materials which are classed as CONDUCTORS tend to INCREASE their resistivity with an increase in temperature. INSULATORS however are liable to DECREASE their resistivity with an increase in temperature. Materials used for practical insulators (glass, plastic etc) only exhibit a marked drop in their resistivity at very high temperatures. They remain good insulators over all temperatures they are likely to encounter in use.
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