6,768 research outputs found
MODLEACH: A Variant of LEACH for WSNs
Wireless sensor networks are appearing as an emerging need for mankind.
Though, Such networks are still in research phase however, they have high
potential to be applied in almost every field of life. Lots of research is done
and a lot more is awaiting to be standardized. In this work, cluster based
routing in wireless sensor networks is studied precisely. Further, we modify
one of the most prominent wireless sensor network's routing protocol "LEACH" as
modified LEACH (MODLEACH) by introducing \emph{efficient cluster head
replacement scheme} and \emph{dual transmitting power levels}. Our modified
LEACH, in comparison with LEACH out performs it using metrics of cluster head
formation, through put and network life. Afterwards, hard and soft thresholds
are implemented on modified LEACH (MODLEACH) that boast the performance even
more. Finally a brief performance analysis of LEACH, Modified LEACH (MODLEACH),
MODLEACH with hard threshold (MODLEACHHT) and MODLEACH with soft threshold
(MODLEACHST) is undertaken considering metrics of throughput, network life and
cluster head replacements.Comment: IEEE 8th International Conference on Broadband and Wireless
Computing, Communication and Applications (BWCCA'13), Compiegne, Franc
Magnetohydrodynamic Viscous Flow Over a Shrinking Sheet With Second Order Slip Flow Model
In this paper, we investigate the magnetohydrodynamic viscous flow with
second order slip flow model over a permeable shrinking surface. We have
obtained the closed form of exact solution of Navier-Stokes equations by using
similarity variable technique. The effects of slip, suction and magnetic
parameter have been investigated in detail. The results show that there are two
solution branches, namely lower and upper solution branch. The behavior of
velocity and shear stress profiles for different values of slip, suction and
magnetic parameters has been discussed through graphs.Comment: 13 Pages, 8 Figures. Accepted for Publication in Heat Transfer
Researc
Clinical trial: protective effect of a commercial fish protein hydrolysate against indomethacin (NSAID)-induced small intestinal injury
Background A partially hydrolysed and dried product of pacific whiting fish is marketed as a health food supplement supporting 'intestinal health'.Aim To examine whether the partially hydrolysed and dried product of pacific whiting fish influenced the small intestinal damaging side effects of the nonsteroidal anti-inflammatory drug, indomethacin.Methods Eight human volunteers completed a double-blind, placebo-controlled, crossover protocol of clinically relevant dose of indomethacin (50 mg t.d.s. p.o. for 5 days) with 7 days of fish hydrolysate or placebo starting 2 days prior to indomethacin. Changes in gut permeability were assessed using 5 h urinary lactulose:rhamnose (L/R) ratios.Results Fish hydrolysate given alone did not affect permeability. In the main study (n = 8), baseline values were similar for both arms (0.28 +/- 0.05 and 0.35 +/- 0.07). Administration of indomethacin (+placebo) caused a fivefold rise in L/R ratios (increasing to 1.54 +/- 0.35), whereas L/R ratios in the same subjects ingesting indomethacin + fish hydrolysate was only 0.59 +/- 0.14 (P < 0.01 vs. indomethacin alone). Dyspeptic symptoms occurred in four of eight subjects taking indomethacin alone, but zero of eight when hydrolysate was co-administered.Conclusion Natural bioactive products (nutriceuticals), such as fish hydrolysates, may provide a novel approach to the prevention and treatment of NSAID-induced and other gastrointestinal injurious conditions
Reducing Environment Pollution by Reusing of Alum Sludge Waste in Stone Mastic Asphalt Mixtures
Globally, a huge quantity of alum sludge waste is produced as a by-product material from drinking water treatment plants that utilize aluminum salts as an essential coagulate and is the most generally produced water treatment remaining sludge around the world, which causes a serious environmental problem. Direct discarding of this substance has ecological effects. Hence, it is important to reuse this alum sludge waste material in such a manner to diminish its detrimental impacts on the environment. This research investigates the possibility of reusing alum sludge waste as a partial replacement of cement filler in stone mastic asphalt (SMA) paving mixtures. For this investigation, the alum sludge was used as a filler material in SMA mixtures in two modes; dried alum sludge at 110°C and burned alum sludge at 700°C. Different percentages of alum sludge were used as a replacement by the total weight of mineral filler at 0, 20, 40, 60, 80, and 100%. The results showed that using alum sludge as a substitution of filler in SMA mixtures reduces the performance of the mixtures in terms of Marshall properties and tensile strength for both dried and burned alum sludge compared with a standard mix. However, the performance of the mixtures containing burned alum sludge gave a better performance than the mixtures containing dried alum sludge
Fluctuating charge density waves in a cuprate superconductor
Cuprate materials hosting high-temperature superconductivity (HTS) also
exhibit various forms of charge and/or spin ordering whose significance is not
fully understood. To date, static charge-density waves (CDWs) have been
detected by diffraction probes only at special doping or in an applied external
field. However, dynamic CDWs may also be present more broadly and their
detection, characterization and relationship with HTS remain open problems.
Here, we present a new method, based on ultrafast spectroscopy, to detect the
presence and measure the lifetimes of CDW fluctuations in cuprates. In an
underdoped La1.9Sr0.1CuO4 film (Tc = 26 K), we observe collective excitations
of CDW that persist up to 100 K. This dynamic CDW fluctuates with a
characteristic lifetime of 2 ps at T = 5 K which decreases to 0.5 ps at T = 100
K. In contrast, in an optimally doped La1.84Sr0.16CuO4 film (Tc = 38.5 K), we
detect no signatures of fluctuating CDWs at any temperature, favoring the
competition scenario. This work forges a path for studying fluctuating order
parameters in various superconductors and other materials.Comment: 16 pages, 4 figures, accepted to Nature Material
Nanobiotechnology for the production of biofuels from spent tea
Bioenergy is the only alternative and cheap source of energy which can be made easily available to the world. The present experiment included three steps for the conversion of spent tea (Camellia sinensis) into biofuels. In the first step, spent tea was gasified using Co nano catalyst at 300°C and atmospheric pressure. Catalytic gasification of spent tea yielded 60% liquid extract, 28% fuel gases and 12% charcoal. Gaseous products contain 53.03% ethene, 37.18% methanol and 4.59% methane. In the second step of the experiment, liquid extract of spent tea obtained from gasification, on transesterification gave 40.79% ethyl ester (biodiesel). In the third step, Aspergillus niger’s growth on spent tea produced 57.49% bioethanol. This study reports an interesting finding that spent tea (solid waste) could be used not only for the production of biodiesel and bioethanol but also hydrocarbon fuel gases. The world today is consuming several million tons of tea yearly. The present technology could be utilized to produce alternate energy
A study of trends and techniques for space base electronics
A sputtering system was developed to deposit aluminum and aluminum alloys by the dc sputtering technique. This system is designed for a high level of cleanliness and for monitoring the deposition parameters during film preparation. This system is now ready for studying the deposition and annealing parameters upon double-level metal preparation. A technique recently applied for semiconductor analysis, the finite element method, was studied for use in the computer modeling of two dimensional MOS transistor structures. It was concluded that the method has not been sufficiently well developed for confident use at this time. An algorithm was developed for confident use at this time. An algorithm was developed for implementing a computer study which is based upon the finite difference method. The program which was developed was modified and used to calculate redistribution data for boron and phosphorous which had been predeposited by ion implantation with range and straggle conditions. Data were generated for 111 oriented SOS films with redistribution in N2, dry O2 and steam ambients
New nanomaterial and process for the production of biofuel from metal hyper accumulator water hyacinth
Three different studies were performed for the conversion of water hyacinth (Eichhornia crassipes) plant into biofuel. In the first study, water hyacinth was saccharified with diluted sulfuric acid (1% v/v at 110°C for one hour), fermented by yeast (Saccharomyces cerevisiae). The results showed the formation of 55.20% ethanol and 41.66% acetic acid. In another experiment, water hyacinth was gasified by using Ni and Co nano catalysts at 50 - 400°C and atmospheric pressure. In catalytic gasification, CH4 (2.41 - 6.67%), C2H4 (19.74 - 45.52%), C3H4 (21.04 - 45.52%), CH3OH (1.43 - 24.67%), and C3H8 / CH3CHO (0.33 -26.09%) products were obtained. In this study, anatase form of titanium dioxide photocatalyst was used. The reaction was performed at room temperature which gives methane, methanol and ethanol.This study also reports an interesting finding that metal contaminated water hyacinth could be used for not only the production of biofuel but also hydrocarbons
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