AAS - A Tool for Monitoring Trace Metals in Environment

Rapid industrialisation coupled with geochemical alter-ations posed a major threat to environment. Pollution of air, soil and water with both organics and inorganics is a matter of great concern, however, the non-degradable persistent trace metals are the most pressing problems of present decade. They are the most insidious pollutants because of their non-biodegradable nature and property to effect all forms of ecological systems. Owing to their toxicity and ill-effects on living being the present day scientists and researchers have developed interest in the amounts, origin and fate of certain elements. For example certain trace elements such as cadmium, chromium, mercury, lead and vanadium are of great concern because of their toxic effects on plants, animals and humans. Essential trace elements, such as chromium, vanadium, manganese. iron, cobalt, copper and zinc are indispensible for the growth and survival of mankind. From the point of view of toxicity metals can be classified according to the following three criteria: non-critical, toxic and very toxic. Classification of elements according to toxicity and availability is given in Table-1. The impact of heavy metal contamination in biosphere is slowly being reco-gnised as a potential Health Hazard not only to human beings but almost all the major industries are also affected by trace elements imbalances. For instance the presence of silica in boiler feed water at 30 to 1000 ppm level leads to appearance of scale forming silicates which reduces the heat transfer from boiler

Atomic Absorption Spectrometry - Present and Future

The development of analytical chemistry methods is mainly prompted by three aims: (a) an improvement of the power of detection (b) increase in analytical reliability in terms of freedom from systematic errors and optimal analytical precision, (c) and cost reduction

Instrumental Techniques for Chemical Analysis of Ferro-Alloys

Ferro-alloys are metallic addition agents used in iron and steel making to incorporate an alloying element into the molten material or to refine steel, for example by removal of oxygen and sulphur, in which case the alloying element is only to a minor extent incorporated in the steel. These additions are made to the ladle before the pouting into moulds. Most ferro-alloys are alloys of the main element (usually, 15-85%), with iron, hence the name. Sometimes ferro-alloy contain two or three alloying elements which act in different ways and there are also complex boron alloys in which titanium and aluminum can fix the oxygen and nitrogen in the steel bath so, that the boron may enter Solution and exert a metallurgical influence

An Evaluate of Pattern Identification Programs and Its Strategies

At the moment existence, Pattern Recognition has turned into an essential idea from analyst perspective. It is utilized as a part of numerous applications like Speech acknowledgment, facade acknowledgment, Biometrics and numerous other moreover. This survey paper will clarify numerous applications and methodologies of the example acknowledgment. Primarily four sorts of methodologies measurable, layout, auxiliary and neural approach. Furthermore, promote factual approach order is likewise done

Axigluons cannot explain the observed top quark forward-backward asymmetry

We study an SU(3)^2 axigluon model introduced by Frampton, Shu, and Wang to explain the recent Fermilab Tevatron observation of a significant positive enhancement in the top quark forward-backward asymmetry relative to standard model predictions. First, we demonstrate that data on neutral B_d-meson mixing excludes the region of model parameter space where the top asymmetry is predicted to be the largest. Keeping the gauge couplings below the critical value that would lead to fermion condensation imposes further limits at large axigluon mass, while precision electroweak constraints on the model are relatively mild. Furthermore, by considering an extension to an SU(3)^3 color group, we demonstrate that embedding the model in an extra-dimensional framework can only dilute the axigluon effect on the forward-backward asymmetry. We conclude that axigluon models are unlikely to be the source of the observed top quark asymmetry.Comment: 12 pages, 7 eps figures included. Minor changes to conform with published versio

Scalable parallel communications

Coarse-grain parallelism in networking (that is, the use of multiple protocol processors running replicated software sending over several physical channels) can be used to provide gigabit communications for a single application. Since parallel network performance is highly dependent on real issues such as hardware properties (e.g., memory speeds and cache hit rates), operating system overhead (e.g., interrupt handling), and protocol performance (e.g., effect of timeouts), we have performed detailed simulations studies of both a bus-based multiprocessor workstation node (based on the Sun Galaxy MP multiprocessor) and a distributed-memory parallel computer node (based on the Touchstone DELTA) to evaluate the behavior of coarse-grain parallelism. Our results indicate: (1) coarse-grain parallelism can deliver multiple 100 Mbps with currently available hardware platforms and existing networking protocols (such as Transmission Control Protocol/Internet Protocol (TCP/IP) and parallel Fiber Distributed Data Interface (FDDI) rings); (2) scale-up is near linear in n, the number of protocol processors, and channels (for small n and up to a few hundred Mbps); and (3) since these results are based on existing hardware without specialized devices (except perhaps for some simple modifications of the FDDI boards), this is a low cost solution to providing multiple 100 Mbps on current machines. In addition, from both the performance analysis and the properties of these architectures, we conclude: (1) multiple processors providing identical services and the use of space division multiplexing for the physical channels can provide better reliability than monolithic approaches (it also provides graceful degradation and low-cost load balancing); (2) coarse-grain parallelism supports running several transport protocols in parallel to provide different types of service (for example, one TCP handles small messages for many users, other TCP's running in parallel provide high bandwidth service to a single application); and (3) coarse grain parallelism will be able to incorporate many future improvements from related work (e.g., reduced data movement, fast TCP, fine-grain parallelism) also with near linear speed-ups

Export performance of Indian fisheries in the context of globalisation

Internationally traded fisheries products are characterised by a high degree of heterogenity, reflecting the wide range of species and of processing techniques. Indian sea food industry, by and large still remains as a supplier of raw materials to the pre processors in foreign countries and 90 per cent goes in bulk packs, which is the prime reason for the drastic reduction in the unit value realisation (Rao and Prakash, 1999). India 's share in the overall trade of the world is 1.5 to 2 per cent

Extractive-photometric determination of cobalt(II) in steels using 4-(2-pyridylazo)resorcinol and xylometazoline hydrochloride

Cobalt(II) forms anionic chelates with 4-(2-pyridylazo)resorcinol (PAR) at pH 7.0-8.0, which can be quantitatively extracted into chloroform as an ion-pair with xylometazolonium cation (XMH). The ion-association system has an absorption maximum at 535 nm and obeys Beers law in the range 0-1.6 mu g of Co/ml with a molar absorptivity 42000 dm(3) mol(-1) cm(-1). The Job's method of continuous variations indicated a composition of 1 : 2 : 2 for cobalt : PAR : XMH for the extracting species. Based on this extraction, a highly sensitive and selective spectrophotometric method for the determination of cobalt in various steels, after prior separation of iron, is described