Temperatures and metallicities of M giants in the galactic Bulge from low-resolution K-band spectra

With the existing and upcoming large multi-fibre low-resolution spectrographs, the question arises how precise stellar parameters such as Teff and [Fe/H] can be obtained from low-resolution K-band spectra with respect to traditional photometric temperature measurements. Until now, most of the effective temperatures in galactic Bulge studies come directly from photometric techniques. Uncertainties in interstellar reddening and in the assumed extinction law could lead to large systematic errors. We aim to obtain and calibrate the relation between Teff and the $\rm ^{12}CO$ first overtone bands for M giants in the galactic Bulge covering a wide range in metallicity. We use low-resolution spectra for 20 M giants with well-studied parameters from photometric measurements covering the temperature range 3200 < Teff < 4500 K and a metallicity range from 0.5 dex down to -1.2 dex and study the behaviour of Teff and [Fe/H] on the spectral indices. We find a tight relation between Teff and the $\rm ^{12}CO(2-0)$ band with a dispersion of 95 K as well as between Teff and the $\rm ^{12}CO(3-1)$ with a dispersion of 120 K. We do not find any dependence of these relations on the metallicity of the star, making them relation attractive for galactic Bulge studies. This relation is also not sensitive to the spectral resolution allowing to apply this relation in a more general way. We also found a correlation between the combination of the NaI, CaI and the $\rm ^{12}CO$ band with the metallicity of the star. However this relation is only valid for sub-solar metallicities. We show that low-resolution spectra provide a powerful tool to obtain effective temperatures of M giants. We show that this relation does not depend on the metallicity of the star within the investigated range and is also applicable to different spectral resolution.Comment: 6 pages, accepted for publication in Astronomy&Astrophysic

Ergonomic Chair Design For Thermal Comfort Using Phase Change Materials

The metabolism process of humanoids is well designed for emitting the heat constantly. But no heat transfer phenomena occur from the spinal side of the body in sitting posture. The proper heat transfer is arrested in the sitting posture; this makes the human to feel discomfort. The bus drivers are the main victims who face this problem every day and cause of the disease called “hemorrhoid”. This project mainly focused to modify and construct a convenient chilled cushion chair with jam-backed Phase Change Material (PCM) to overcome such problems. This chair absorbs body heat when occupied and discharges while vacant. The stages when liquid change to solid and solid change to liquid occurs nearly by a constant temperature. The chair provides a cooling effect and also a cushioning effect to the occupier. The PCMs are having large latent heat and provide a cooling effect by maintaining nearly by constant temperature to the human body.  The jam-backed chilled cushion chair is invented for improved thermal comfort for the driver for some extended time by the proper temperature that acceptable level of the human. The performance tests are carried out to evaluate the working of the pad

Novel Scheme for Minimal Iterative PSO Algorithm for Extending Network Lifetime of Wireless Sensor Network

Clustering is one of the operations in the wireless sensor network that offers both streamlined data routing services as well as energy efficiency. In this viewpoint, Particle Swarm Optimization (PSO) has already proved its effectiveness in enhancing clustering operation, energy efficiency, etc. However, PSO also suffers from a higher degree of iteration and computational complexity when it comes to solving complex problems, e.g., allocating transmittance energy to the cluster head in a dynamic network. Therefore, we present a novel, simple, and yet a cost-effective method that performs enhancement of the conventional PSO approach for minimizing the iterative steps and maximizing the probability of selecting a better clustered. A significant research contribution of the proposed system is its assurance towards minimizing the transmittance energy as well as receiving energy of a cluster head. The study outcome proved proposed a system to be better than conventional system in the form of energy efficiency

Novel Bacteria Foraging Optimization for Energy-efficient Communication in Wireless Sensor Network

Optimization techniques based on Swarm-intelligence has been reported to have significant benefits towards addressing communication issues in Wireless Sensor Network (WSN). We reviewed the most dominant swarm intelligence technique called as Bacteria Foraging Optimization (BFO) to find that there are very less significant model towards addressing the problems in WSN. Therefore, the proposed paper introduced a novel BFO algorithm which maintains a very good balance between the computational and communication demands of a sensor node unlike the conventional BFO algorithms. The significant contribution of the proposed study is to minimize the iterative steps and inclusion of minimization of both receiving / transmittance power in entire data aggregation process. The study outcome when compared with standard energy-efficient algorithm was found to offer superior network lifetime in terms of higher residual energy as well as data transmission performance

Generation of Test Vectors for Sequential Cell Verification

For Application Specific Integrated Circuits (ASIC) and System-on-Chip (SOC) designs, Cell - Based Design (CBD) is the most prevalent practice as it guarantees a shorter design cycle, minimizes errors and is easier to maintain. In modern ASIC design, standard cell methodology is practiced with sizable libraries of cells, each containing multiple implementations of the same logic functionality, in order to give the designer differing options based on area, speed or power consumption. For such library cells, thorough verification of functionality and timing is crucial for the overall success of the chip, as even a small error can prove fatal due to the repeated use of the cell in the design. Both formal and simulation based methods are being used in the industry for cell verification. We propose a method using the latter approach that generates an optimized set of test vectors for verification of sequential cells, which are guaranteed to give complete Single Input Change transition coverage with minimal redundancy. Knowledge of the cell functionality by means of the State Table is the only prerequisite of this procedure

M Giants with IGRINS II. Chemical Evolution of Fluorine at High Metallicities

The origin and evolution of fluorine in the Milky Way galaxy is still in debate. In particular, the increase of the [F/Fe] in metal-rich stars found from near-IR HF-lines is challenging to explain theoretically. We determine the fluorine abundances from 50 M giants in the solar neighbourhood spanning a broad range of metallicities (-0.9<[Fe/H]<0.25 dex). These stars are cool enough to have an array of HF lines in the K band. We observed the stars with the IGRINS and investigate each of ten HF molecular lines in detail. Based on a detailed line-by-line analysis of ten HF lines, we find that the R19, R18 and R16 lines should primarily be used for abundance analysis. The R15, R14 and R13 lines can also be used, but the trends based on these lines show increasing dependencies with the stellar parameters. The strongest HF lines, namely R12, R11, R9 and R7 should be avoided since the abundances from them show significant trends with the stellar parameters, and a high sensitivity to variations in the microturbulence, especially for coolest metal-rich stars. This leads to a huge scatter and high fluorine abundances for supersolar metallicity stars, not seen in the trends from the weaker lines for the same stars. When estimating the final mean fluorine abundance trend versus metallicity, we neglect the fluorine abundances from the four strongest lines (R7, R9, R11 and R12) for all stars and use only those derived from R16, R18, and R19 for the coolest metal-rich stars. We confirm the flat trend of [F/Fe] found in other studies in the metallicity range of -1.0<[Fe/H]<0.0. We also find a slight enhancement at supersolar metallicities (0<[Fe/H]<0.15) but we cannot confirm the upward trend seen at [Fe/H]>0.25. We need more observations of M giants at super solar metallicities with a spectrometer like IGRINS to confirm if the metal-rich fluorine abundance upturn is real or not.Comment: 11 pages, 6 figures, Accepted for publication in A&

Innovative exploitation of deepsea crustaceans along the Kerala coast

Exploratory surveys carried out since 1965 by fishing vessels belonging to different governmental agencies have revealed the occurrence of commercially Important deep sea crustaceans in trawlable concentration along the south-west coast of India

The "karikkadi" fishery of Kerala

Parapenaeopsis stylifera, (called 'Karikkadi Chemmeen' ) is the most important species of prawn contributing to the commercial fishery of Kerala coast. An experimental shrimp trawling conducted for a period of two years has shown that during the non-monsoon period (September/October to May) most of the shrimp stocks occupy the coastal waters within the 20 m depth contour. With the commencement of southwest monsoon and the consequent changes in the environmental conditions, the prawns leave the inshore areas in large numbers to the deeper zones. The wide annual fluctuations observed at important centres, the occurrence of juvenile prawns in large quantities noticed quite often in the fishery, call for proper management and conservation measures

'Fair' Partitions of Polygons - an Introduction

We address the question: Given a positive integer $N$, can any 2D convex polygonal region be partitioned into $N$ convex pieces such that all pieces have the same area and same perimeter? The answer to this question is easily `yes' for $N$=2. We prove the answer to be `yes' for $N$=4 and also discuss higher powers of 2.Comment: 7 pages. 1 figure. This version (v6) is mostly a formal reworking of the main proof in v2 which was uploaded in December 200

Observations on the prawn fishery off Sakthikulangara in the light of monsoon trawling ban

Sakthikulangara is the most important prawn landing center in Kerala. Study on the prawn fishery exploited by shrimp trawlers for a period of 15 years during 1986-200b at rnis centre indicated a decline in the landings in the first five year period followed by improved fishery between 1991 and 1995. However, decline in catch and catch rate was registered in the next 5 years. Contribution of Sakthikulangara to the Kerala prawn fishery declined from 51% in seventies to 30% in eighties and 24% in nineties. 'Karikkadi' (Parapenaeopsis stylifera) contributed to 68% of the average annual production during 1986 - 2000. Extension of trawling to middle shelf waters and introduction of night trawling transformed the complexion of prawn fishery in the nineties with the addition of nonconventional species such as Trachypenaeus curuirostris, Solenocera choprai and Penaeus canaliculatus. Analysis of data on prawn fishery at Sakthikulangara for a period of 20 years (1981-2000) to study the impact of ban on monsoon trawling has indicated that trawling ban for a short duration of 45 days in the first half of the season is advantageous to the 'Karikkadi' fishery