Influence of zeolitic structure on photoreduction property and hydrogen evolution reaction

A new photocatalytic material developed by supporting TiO₂ in combination with transition metal ion like cobalt and heteropolyacid (HPA) on the surface is facilitating enhanced photoreduction of water and methyl orange. Zeolites being a solid acid play an important role in the electron transfer reaction, facilitated by the Lewis acid sites in the form of aluminium ions. In the present work, four different zeolite matrices namely, NaY zeolite, ultrastable zeolite Y, beta zeolite and titanium silicate-1 have been used for the synthesis of new photocatalytic materials. These materials have been evaluated for water splitting by an initial screening procedure using methyl orange photoreduction. The photocatalyst containing Na Y has emerged as a potential photocatalyst with hydrogen evolution rate of 2730 μmol/h/g of TiO₂. Hydrogen evolution was not observed for the composite photocatalysts synthesized using the other zeolite matrices. It has been observed that physico-chemical properties like Si/Al ratio, acidity and basicity of the zeolite support have a tremendous influence on the photoreduction property of these zeolite matrices.     

A New Model for Keyhole Mode Laser Welding Using FLUENT

Evolution of the free surface at gas?Cliquid interface during keyhole mode welding is complex and its calculation is computationally expensive. Similarly, models based on only heat conduction without considering vapour cavity and liquid convection around it, are computationally efficient but are not effective in defining the weld pool shape especially for low conducting material like steel. In the present study a useful yet computationally efficient model has been presented for keyhole mode laser welding using commercial software FLUENT. Here instead of evolving the free surface of keyhole in a rigorous way, various possible steady keyhole shapes are assumed partially based on literature evidence and subsequently their dimensions are calculated by an overall heat balance. The estimated keyhole profile is then mapped into the thermo-fluid framework of FLUENT and steady computational fluid dynamics calculations is carried out around the keyhole that is considered rigid wall at boiling temperature. Next, an optimized keyhole shape is identified by comparing the predicted fusion lines with the experimental weld fusion lines reported in literature. Finally, using this optimized keyhole shape independent predictions are made for two materials of widely different thermal conductivities, like steel and aluminum, under different operating conditions. In all cases the results of the present simulation is found to in close agreement with experimental data and even better than the model predictions reported in literature. The present model emerges as a simple yet effective model for predicting the weld bead profile encompassing wide range of materials under different operating conditions.     

<Emphasis Type="Italic">In situ</Emphasis> Observation of Calcium Oxide Treatment of Inclusions in Molten Steel by Confocal Microscopy

Calcium treatment of aluminum killed steel was observed in situ using high-temperature confocal scanning laser microscope (HT-CSLM). This technique along with a novel experimental design enables continuous observation of clustering behavior of inclusions before and after the calcium treatment. Results show that the increase in average inclusion size in non-calcium-treated condition was much faster compared to calcium-treated condition. Results also show that the magnitude of attractive capillary force between inclusion particles in non-treated condition was about 10^?15 N for larger particles (10 µm) and 10^?16 N for smaller particles (5 µm) and acting length of force was about 30 µm. In the case of calcium-treated condition, the magnitude and acting length of force was reduced to 10^?16 N and 10 µm, respectively, for particles of all sizes. This change in attractive capillary attractive force is due to change in inclusion morphology from solid alumina disks to liquid lens particles during calcium treatment.     

Preparation,characterization and thermolysis of nitrate and perchlorate salts of 2,4,6-trimethylaniline

Nitrate and perchlorate salts of 2,4,6-trimethylaniline have been prepared and characterized by X-ray crystallography and gravimetric analyses. Their thermal decomposition has been studied by TG, TG–DSC and ignition/explosion delays. It has been observed that proton transfer from substituted anilinium ion to nitrate and perchlorate ion regenerate amine, HNO₃ and HClO₄ in condensed phase at higher temperature, where oxidation–reduction between amine and acids leads to ignition and explosion. The kinetics of thermal decomposition was evaluated by applying model fitting as well as isoconversional methods. The values of calculated activation energy of nitrate and perchlorate salts are 77.9 and 118.2 kJ mol^?1 respectively. The possible pathways of thermolysis of these salts have also been proposed.     

Vasopressin Receptor Type-2 Mediated Signaling in Renal Cell Carcinoma Stimulates Stromal Fibroblast Activation

Vasopressin type-2 receptor (V2R) is ectopically expressed and plays a pathogenic role in clear cell renal cell carcinoma (ccRCC) tumor cells. Here we examined how V2R signaling within human ccRCC tumor cells (Caki1 cells) stimulates stromal cancer-associated fibroblasts (CAFs). We found that cell culture conditioned media from Caki1 cells increased activation, migration, and proliferation of fibroblasts in vitro, which was inhibited by V2R gene silencing in Caki1 cells. Analysis of the conditioned media and mRNA of the V2R gene silenced and control Caki1 cells showed that V2R regulates the production of CAF-activating factors. Some of these factors were also found to be regulated by YAP in these Caki1 cells. YAP expression colocalized and correlated with V2R expression in ccRCC tumor tissue. V2R gene silencing or V2R antagonist significantly reduced YAP in Caki1 cells. Moreover, the V2R antagonist reduced YAP expression and myofibroblasts in mouse xenograft tumors. These results suggest that V2R plays an important role in secreting pro-fibrotic factors that stimulate fibroblast activation by a YAP-dependent mechanism in ccRCC tumors. Our results demonstrate a novel role for the V2R-YAP axis in the regulation of myofibroblasts in ccRCC and a potential therapeutic target.     

Energy-aware Virtual Machine Migration for Cloud Computing - A Firefly Optimization Approach

Energy efficiency has grown into a latest exploration area of virtualized cloud computing paradigm. The increase in the number and the size of the cloud data centers has propagated the need for energy efficiency. An extensively practiced technology in cloud computing is live virtual machine migration and is thus focused in this work to save energy. This paper proposes an energy-aware virtual machine migration technique for cloud computing, which is based on the Firefly algorithm. The proposed technique migrates the maximally loaded virtual machine to the least loaded active node while maintaining the performance and energy efficiency of the data centers. The efficacy of the proposed technique is exhibited by comparing it with other techniques using the CloudSim simulator. An enhancement in the average energy consumption of about 44.39 % has been attained by reducing an average of 72.34 % of migrations and saving 34.36 % of hosts, thereby, making the data center more energy-aware.     

Stability of Whey Proteins during Thermal Processing: A Review

Whey proteins have many benefits due to their high nutritional value and their various applications in food products. A drawback of whey proteins is their instability to thermal processing, which leads to their denaturation, aggregation, and, under some conditions, gelation. As thermal processing is a major treatment in the processing of milk and milk products, its influence on whey proteins has been extensively studied. Understanding the mechanisms involved during each stage of denaturation and aggregation of whey proteins is critical to devising ways of improving their stability. These aspects are reviewed in this paper. Also covered are approaches to preventing or reducing heat‐induced aggregation of whey proteins. Inhibition of aggregate formation has considerable potential for alleviating the problems that arise from the instability of whey proteins.     

A world pattern of the optimum ash levels of cleans from the washability data of typical coal seams

For every coal of specified size there is an optimal cut point, which more or less demarcates the free and fixed dirt in the coal. Technically speaking, one can expect the maximum advantage in washing a coal by separating it at this optimal cut point. A method is described for determining this point (the Optimum Degree of Washability) for any coal, from normal float-and-sink data. The Washability Number (directly calculated from the Optimum Degree of Washability) and the cleans ash at the optimum separation level are useful parameters for defining the ease or difficulty of washing. This Optimum Degree of Washability generally bears a rectilinear relation to the earlier Washability Index. While the values of Washability Number are generally higher and the optimum cleans ash level usually lower for the coal seams formed under quiescent conditions, the opposite is true for coal seams deposited under turbulent conditions. Thus, in the association of dirt (minerals) with coal (macerals), the higher the Washability Number, the greater is the heterogeneity of a coal seam inclusive of the dirt and vice versa. The Washability Number and the optimum cleans ash also undergo changes according to the size of crushing and grading of the raw coal. Characteristics on the above new basis are recorded for regional variation of some typical coal seams covering deposits of both ‘in situ’ and ‘drift’ origin, and significant observations were made regarding the trend of variation of the same seam at different sectors of the regions. In respect of deposits of drift origin, some regular sequence was also noted in the related values from the upper to the lower horizons. On the basis of typical data collected from more than 25 coal-producing countries, a worldwide projection has been made in this paper. A general pattern emerges with significant limits of variation between the coals of the Northern and Southern Hemispheres. This pattern could be better defined if further studies were conducted with coals of the same geological age and their washability characteristics were evaluated under standard conditions of test by crushing them initially to a particular top size. Further, from a knowledge of the different ranges of Washability Number, it is possible for a coal-preparation engineer to take tentative decisions on a size of crushing and a system of washing specifically suited to the beneficiation of any run-of-mine coal.     

A hybrid technique for the PAPR reduction of NOMA waveform

Non-orthogonal multiple access (NOMA) is a great contender for future cellular modulation due to its desirable properties like massive connectivity, high data rate transmission, and high spectral efficiency. However, its peak-to-average power ratio (PAPR) is significant, which becomes a significant disadvantage for the efficient operability of the NOMA waveform compared to current techniques. Several PAPR reduction algorithms like selective mapping (SLM), partial transmission sequence (PTS), and companding techniques have been proposed to lower the PAPR of multicarrier waveforms (MCWs). PTS reduces the PAPR but has high complexity. On the other hand, SLM has a less complex framework, but its PAPR performance is not as efficient as PTS. Companding methods reduce the PAPR by compressing the signals at the transmitter, which unfortunately reduces the dynamic range of the signal. In this work, we propose a hybrid algorithm (SLM + PTS) with a companding method for the first time for the NOMA waveform, which efficiently reduces the PAPR with low computational complexity. Furthermore, we compare the performances of a host of candidate algorithms like SLM, PTS, hybrid (SLM + PTS), hybrid + A law (SLM–PTS–A law), and hybrid + Mu law (SLM–PTS–Mu law). The results of the experiments show that the hybrid + Mu law did a better job than the existing PAPR reduction algorithms.