An Atom Laser is not monochromatic

We study both numerically and analytically the possibility of using an adiabatic passage control method to construct a Mach-Zehnder interferometer (MZI) for Bose-Einstein condensates (BECs) in the time domain, in exact one-to-one correspondence with the traditional optical MZI that involves two beam splitters and two mirrors. The interference fringes one obtains from such a minimum-disturbance set up clearly demonstrates that, fundamentally, an atom laser is not monochromatic due to interatomic interactions. We also consider how the amount of entanglement in the system correlates to the interference fringes.Comment: 4 figures. Submitted for publicatio

मत्स्यबीजाचा संग्रह, वाहतूक व संचयन

The collection of seeds from the wild is the main source to obtain the stocking material for the cage. This can be carried out when the seed production cost is very high or where the availability of seed from nature is in large quantity. It is important to know the biology of the fish species either to duplicate reproductive condition on the farm or to know when and where to collect the fish. The artificially produced seeds in the hatchery are used widely in cage culture practice all over the world to avoid depletion of stock in the wild. The transportation of the seeds to the culture site plays an important role as maximum mortality occurs during this process because of change in metabolic pattern of the fish due to stress. The appropriate quantity of seeds should be stocked in each cage for obtaining good production. This chapter mainly deals with all these aspects in detail

Population eruption of sunset shell Siliqua radiata (Linnaeus, 1758) along Versova beach in Mumbai

Sudden population eruption of Siliqua radiata during monsoon months (June-August 2008) was observed along Versova beach in Mumbai. Relationship between shell length (SL) and total weight (TW) was TW = 0.0001137 * SL 2.67922, shell length (SL) and meat weight (MW) was MW = 0.0000237 * SL 2.91756. S. radiata had isometric growth. The average density was estimated as 14 per square meter and the biomass was 153 g.m-2. The proportion of meat was 60%. Analysis of meat showed high amount of heavy metals namely copper, cadmium and arsenic

Quantized Orbits and Resonant Transport

A tight binding representation of the kicked Harper model is used to obtain an integrable semiclassical Hamiltonian consisting of degenerate "quantized" orbits. New orbits appear when renormalized Harper parameters cross integer multiples of $\pi/2$. Commensurability relations between the orbit frequencies are shown to correlate with the emergence of accelerator modes in the classical phase space of the original kicked problem. The signature of this resonant transport is seen in both classical and quantum behavior. An important feature of our analysis is the emergence of a natural scaling relating classical and quantum couplings which is necessary for establishing correspondence.Comment: REVTEX document - 8 pages + 3 postscript figures. Submitted to Phys.Rev.Let

Iterative Approximate Consensus in the presence of Byzantine Link Failures

This paper explores the problem of reaching approximate consensus in synchronous point-to-point networks, where each directed link of the underlying communication graph represents a communication channel between a pair of nodes. We adopt the transient Byzantine link failure model [15, 16], where an omniscient adversary controls a subset of the directed communication links, but the nodes are assumed to be fault-free. Recent work has addressed the problem of reaching approximate consen- sus in incomplete graphs with Byzantine nodes using a restricted class of iterative algorithms that maintain only a small amount of memory across iterations [22, 21, 23, 12]. However, to the best of our knowledge, we are the first to consider approximate consensus in the presence of Byzan- tine links. We extend our past work that provided exact characterization of graphs in which the iterative approximate consensus problem in the presence of Byzantine node failures is solvable [22, 21]. In particular, we prove a tight necessary and sufficient condition on the underlying com- munication graph for the existence of iterative approximate consensus algorithms under transient Byzantine link model. The condition answers (part of) the open problem stated in [16].Comment: arXiv admin note: text overlap with arXiv:1202.609

The Influence of Transient Thermal Gradients and Substrate Constraint on Delamination of Thermal Barrier Coatings

A systematic study of factors affecting the delamination energy release rate and mode mix of a thermal barrier coating attached to a substrate is presented accounting for the influence of thermal gradients combined with rapid hot surface cooling. Transient thermal gradients induce stress gradients through the coating and substrate, which produce overall bending if the substrate is not very thick and if it is not constrained. Due to their influences on the coating stresses, substrate thickness and constraint are important aspects of the mechanics of delamination of coating-substrate systems, which must be considered when laboratory tests are designed and for lifetime assessment under in-service conditions. Temperature gradients in the hot state combined with rapid cooling give rise to a maximum energy release rate for delamination that occurs in the early stage of cooling and that can be considerably larger than the driving force for delamination in the cold state. The rates of cooling that give rise to a large early stage energy release rate are identified.Engineering and Applied Science

Advanced photovoltaic power systems using tandem GaAs/GaSb concentrator modules

In 1989, Boeing announced the fabrication of a tandem gallium concentrator solar cell with an energy conversion efficiency of 30 percent. This research breakthrough has now led to panels which are significantly smaller, lighter, more radiation resistant, and potentially less expensive than the traditional silicon flat plate electric power supply. The new Boeing tandem concentrator (BTC) module uses an array of lightweight silicone Fresnel lenses mounted on the front side of a light weight aluminum honeycomb structure to focus sunlight onto small area solar cells mounted on a thin back plane. This module design is shown schematically. The tandem solar cell in this new module consists of a gallium arsenide light sensitive cell with a 24 percent energy conversion efficiency stacked on top of a gallium antimonide infrared sensitive cell with a conversion efficiency of 6 percent. This gives a total efficiency 30 percent for the cell-stack. The lens optical efficiency is typically 85 percent. Discounting for efficiency losses associated with lens packing, cell wiring, and cell operating temperature still allows for a module efficiency of 22 percent which leads to a module power density of 300 Watts/sq. m. This performance provides more than twice the power density available from a single crystal silicon flat plate module and at least four times the power density available from amorphous silicon modules. The fact that the lenses are only 0.010 ft. thick and the aluminum foil back plane is only 0.003 ft. thick leads to a very lightweight module. Although the cells are an easy to handle thickness of 0.020 ft., the fact that they are small, occupying one-twenty-fifth of the module area, means that they add little to the module weight. After summing all the module weights and given the high module power, we find that we are able to fabricate BTC modules with specific power of 100 watts/kg

Role and acceptability of traditional birth attendants (DAIs) in a rural community in South India

Dais are the traditional birth attendants, conducting deliveries at home in the majority of villages in India. A study was planned to find out the feasibility of utilising the services of the dais in case-finding in Tuberculosis (TB) and for drug delivery to diagnosed patients. As a preliminary step, a survey was done with a view to find out the role and acceptability of the dais by the community in 5% of households in randomly selected 24 of the 48 villages in Sriperumbudur taluk in Tamil Nadu, where a voluntary organisation. "PREPARE" was delivering primary health care through dais. A total of 466 individuals, either the head of the household or any other responsible person available, were interviewed to find out the role and acceptability of the dais by the community. The salient findings of this study are that 83% mentioned that the dais reside in their respective villages. hence the services of the dais were available at ail times and 82 % had stated that the services were useful to them. This background information is essential for health planners so that this task force could be effectively utilised in health programmmes, in the rural areas in India