Reliable Data Analysis through Blockchain based Crowdsourcing in Mobile Ad-hoc Cloud

Mobile Networks and Applications - Mobile Ad-hoc Cloud (MAC) is the constellation of nearby mobile devices to serve the heavy computational needs of the resource-constrained edge devices. One of...     

Impact of pulsed electric field pretreatment on yield and quality of lipid extracted from cephalothorax of Pacific white shrimp (Litopenaeus vannamei) by ultrasound-assisted process

Pacific white shrimp cephalothorax was subjected to pulsed electric field (PEF) pretreatment at different electric field strengths (4, 8, 12 and 16 kV cm⁻¹) and pulse numbers (120, 160, 200 and 240) to enhance the extraction yield of lipids. PEF-treated samples were subsequently subjected to lipid extraction using ultrasound-assisted extraction (UAE) process at ultrasound amplitude of 80% for 25 min in continuous mode. PEF-pretreated samples subjected to UAE rendered the highest lipid yield (30.34 g 100 g⁻¹ solids). PEF pretreatment resulted in reduced lipid oxidation as evidenced by the decreases in peroxide value (PV) and thiobarbituric acid reactive substances (TBARS). Lipids from PEF-pretreated samples extracted using UAE had higher content of PUFAs and carotenoids, including astaxanthin, astaxanthin monoester, astaxanthin diester, canthaxanthin and β-carotene. Overall, PEF pretreatment helped in enhancing the extraction yield of lipids and carotenoids from shrimp cephalothorax and reduce lipid oxidation to some extent.     

Mechanistic Model for CaSO4 Fouling on Nanofiltration Membrane

One of the major limitations of nanofiltration (NF) in drinking water treatment is inorganic scaling. In this study, a mechanistic model has been proposed to describe the permeate flux decline process during CaSO4 scaling in NF. It has been observed that the permeate flux decline follows four distinct stages. At first stage, 22–30% flux is reduced due to concentration polarization. At the second stage, flux is not reduced, instead, nucleation of CaSO4 occurs. The major permeate flux decline (60–70%) occurred at the third stage due to CaSO4 cake formation. At the final stage, the system reached the steady state, where rate of CaSO4 deposition on the membrane is balanced by shearing caused by the increase of concentrate flow rate. Beyond this stage, the flux does not decrease significantly. At each stage, the concentration of the salt at the membrane surface was estimated. The maximum salt concentration was found at the initial stage of permeate flux reduction, which gradually decreases as the filtration proceeds.     

Structure and electrochemical performance of ZnO/CNT composite as anode material for lithium-ion batteries

Metal oxides are well-known potential alternatives to graphite as anode materials of lithium-ion batteries, and they can deliver much higher reversible capacities than graphite even at high current densities. In this study, hexagonal disk-shaped ZnO are synthesized by a facile solution reaction of ZnCl₂ and its composite is prepared in the presence of carbon nanotubes (CNTs). The as prepared ZnO/CNT composite has been characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, fourier transform-infrared spectroscopy and Rutherford backscattering spectroscopy. Electrochemical characterization by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic discharge/charge tests demonstrate that the conversion reactions in ZnO and ZnO/CNT electrodes enable reversible capacity of 478 and 602 mAh g^?1, respectively for up to 50 cycles. Our investigation highlights the importance of anchoring of small ZnO particles on CNTs for maximum utilization of electrochemically active ZnO and CNTs for energy storage application in lithium-ion batteries.     

Advance polymeric carbon nanocomposite films with enhanced thermo‐mechanical properties

The homogenous nanocomposite films of UV/O₃ oxidized multiwall carbon nanotubes (MWCNTs) subsequently modified with aniline moiety were synthesized with polymethylmethacrylate (PMMA) through free radical polymerization. The phenylamine functional groups present on the surface of MWCNTs providing an anchoring sites for deposition of Ag metal nanoparticles (NP).The in situ free radical polymerization of MMA in the presence of these well dispersed nanotubes gave a new class of radiation resistant nanocomposite films. The synthesized materials were characterized by FT‐IR, TGA, TEM, EDX, TC, DMA, universal testing machine, and optical microscopy to ascertain their structural morphologies, thermal stability, and mechanical strength. The microscopic and structural properties reflect the homogenous mixing of modified MWCNTs in polymer matrix contributing in enhancement of thermal stability, thermo‐mechanical strength, glass transition temperatures, and thermal conductivity of nanocomposites even at 0.25 wt% addition of modified nanofiller. Thermal and thermo‐mechanical behavior of pre‐ and post‐UV/O₃ irradiated nanocomposite films have been compared with neat polymer. The results revealed that modified nanofiller network can effectively disperse the radiation and has a dramatic reinforcement effect on the nature of degradation of PMMA matrix. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

3T3-L1 adipocytes express two isoforms of phospholipase D in distinct subcellular compartments

Phospholipase D has been implicated as an important enzyme in a range of cellular responses, including regulated secretion and the formation of secretory vesicles, cell proliferation and control of cell morphology. As insulin treatment of adipocytes has been shown to stimulate a phosphatidylcholine-specific phospholipase D and also modulates membrane trafficking, we wished to determine which isoform(s) of phospholipase D were present within adipocytes, to identify their subcellular distribution, and examine how this distribution may change in response to insulin. Using RT-PCR, 3T3-L1 adipocytes were found to express two isoforms of phospholipase D, specifically PLD1b and PLD2a. Using isoform-specific antibodies, PLD1 and PLD2 were found to be present predominantly in intracellular membranes, unlike the situation reported in other cells. Detailed analysis of the intracellular localisation of PLD1 and PLD2 revealed that these isoforms are differentially localised within adipocytes, implying functionally distinct roles for PLD activity in distinct subcellular compartments.     

Introducing Rare Earth Dopants for Controlled Conductivity in Thermoelectric Cobaltites

The conversion of waste heat into electrical energy plays a key role in our current challenge to develop alternative energy technologies to reduce our dependence on fossil fuels. Thermoelectric (TE) materials are the first choice to handle this subject. In TE materials, cobaltites are the material of interest, due to their nontoxic properties. Cobaltites exhibits large TE power, low resistivity, and relatively small thermal conductivity at room temperature. TE material (BiCa_2?x R _x CoO _y ) where R is for rare earth like Nd, (x = 0.0, 0.2) was synthesized in nanoregime by simplified sol–gel method. Simplified sol–gel method was chosen because it gives maximum phase purity and tunable parameters for desired properties. The mechanism used to enhance thermoelectric properties is to reduce thermal conductivity of the material and increase electrical conductivity of the material using nanostructures. Material characterizations were done for structural studies using X-ray diffraction (XRD). XRD revealed monoclinic crystal structure. Temperature-dependent electrical conductivity showed an increase with increase in temperature. Thermal conductivity was also measured. Both electrical resistivity and thermal conductivity decrease as a result of neodymium doping which enhanced its importance as thermoelectric material. The different parameters were correlated to understand the conduction mechanism.     

A simple photo-voltaic tracking system

This paper describes a simple photo-voltaic (PV) tracking system which has been designed and manufactured using a pyramidal stand as a base. A rotating unit consisting of two pairs of modules fixed at an angle of 170° between them was installed at the upper edge of the stand. The four modules and a DC motor were connected to a bridge circuit making the system sensitive to solar tracking. The PV tracker has a DC–DC (24/2 V) converter, DC–AC (24/220 V) inverter and a battery. The modules are able to provide a maximum power of 100 W, which feeds the converter, inverter and DC motor. Wind resistance of the tracker is quite low. The total area of the four modules is 1.26 m². The inclination angle between the modules and the horizontal plane is adjustable (34°±11°) and the tracking angle is 120°. The system can track solar motion with an error of ±10°. The designed PV tracking system, with modules fixed at an angle of 170° to feed the load as well as the DC motor, exhibited it to be an efficient energy-conversion system. The fabricated system offers low wind resistance. The cost analysis data revealed that the proposed design was very economical and cost effective.     

Field incurred chlorpyrifos and 3,5,6-trichloro-2-pyridinol residues in fresh and processed vegetables

The effect of washing, peeling and cooking on residue levels of chlorpyrifos and 3,5,6-trichloro-2-pyridinol (TCP) in winter (spinach, cauliflower, potato) and summer vegetables (eggplant, tomato, okra) was determined. Analysis was carried out by capillary gas chromatography (DB-5MS capillary column) with mass selective detection. The samples were collected from trials conducted under controlled conditions as well as from the farmer’s field. In supervised field trials, the highest chlorpyrifos residue was found at raw stage in spinach (1.87 mg kg⁻¹) followed by okra (1.41 mg kg⁻¹) and eggplant (1.25 mg kg⁻¹). The lowest residue of chlorpyrifos was recorded in cauliflower (0.036 mg kg⁻¹). The chlorpyrifos residue reduced from 15 to 33% after washing, 65–85% post-peeling and cooking further lowered it from 12% to 48% in all the tested vegetables; while an increase in TCP concentration was observed during heat treatment. Out of 267 vegetable samples collected from the farmer’s field, 225 samples contained detectable residues representing 84% rate of contamination. About 6% of samples contained chlorpyrifos residues above maximum residue limits (MRLs). However, vegetable processing reduced the chlorpyrifos residue below the MRL.     

Decode and forward polar coding for Half-duplex two-relay channels based on multilevel construction

Polar codes represent an emerging class of error-correcting codes with power to approach the capacity of the physically degraded relay channel and relevant coding schemes have been proposed in the literature. This paper aims to design new cooperative decode-and-forward (DF) polar coding schemes for half-duplex two-relay channel based on the Plotkin’s construction illustrating their performances gain. In these schemes, we consider the use of time-division process in transmission. The source node transmits its polar-coded information to both relays and the destination nodes during the first time slot. Each relay node receives the data from the source and processes it using the DF protocol. For the second transmission period, each relay first decodes the source signal then after reconstruction of the information reduction matrix based on the multilevel characteristics of polar codes, the extracted data at each relay are recoded using another polar code and transmitted to the destination. At destination node, the signals received from each relay and source nodes are processed by using multi-joint successive cancellation decoding for retrieving the original information bits. We demonstrate via simulation results that by carefully constructed polarisation matrix at each relay node, we can achieve the theoretical capacity in the half-duplex relay channel.