An empirical relation between the melting point and the direct bandgap of semiconducting compounds

The melting point is found to vary linearly with the direct bandgap for groups of semiconductors with common anions. Implication of this empirical result is discussed. The linear relation is used to choose between different reported values of melting point for some compounds.     

EFFICIENT CONVERSION OF CALCUTTA MUNICIPAL SOLID WASTE TO FUEL OIL BY CATALYTIC HYDROGENATION

Pilot plant studies have shown that solid waste represents a valuable source of energy. Efforts have been made to scale up the data to process 1000 tons/day of Calcutta municipal waste. The advantage of this process is that product fuel oil is a saleable commodity, thus becoming an effective waste disposal technique and source for non-conventional energy.     

Parametric analysis of a coal based combined cycle power plant

In the present paper thermodynamic analyses, i.e. both energy and exergy analyses have been conducted for a coal based combined cycle power plant, which consists of pressurized circulating fluidized bed (PCFB) partial gasification unit and an atmospheric circulating fluidized bed (ACFB) char combustion unit. Dual pressure steam cycle is considered for the bottoming cycle to reduce irreversibilities during heat transfer from gas to water/steam. The effect of operating variables such as pressure ratio, gas turbine inlet temperature on the performance of combined cycle power plant has been investigated. The pressure ratio and maximum temperature (gas turbine inlet temperature) are identified as the dominant parameters having impact on the combined cycle plant performance. The work output of the topping cycle is found to increase with pressure ratio, while for the bottoming cycle it decreases. However, for the same gas turbine inlet temperature the overall work output of the combined cycle plant increases up to a certain pressure ratio, and thereafter not much increase is observed. The entropy generation, the irreversibilities in each component of the combined cycle and the exergy destruction/losses are also estimated. Copyright © 2005 John Wiley & Sons, Ltd.     

Role of the endothelial cytoskeleton in blood-brain-barrier permeability to protein

The role of the cytoskeletal elements, microfilaments and microtubules in cerebral endothelial permeability to protein during steady states was investigated by studies of cerebrovascular permeability to horseradish peroxidase (HRP) in rats pretreated with cytochalasin B or colchicine, agents known to disrupt microfilaments and microtubules, respectively. In addition, the effect of colchicine pretreatment on the alterations in cerebrovascular permeability that occur in acute hypertension were studied. Rats infused with cytochalasin B showed increased cerebrovascular permeability to HRP in multifocal areas of the ipsilateral hemisphere. Most of the permeable vessels were arterioles; however, capillaries and venules also showed increased permeability. Ultrastructural studies of permeable vessels showed HRP in all layers of vessel walls and in endothelial and smooth muscle cell pinocytotic vesicles, which were increased in number. Although segments of interendothelial spaces were labeled by tracer, continuous labeling of interendothelial spaces from the luminal to the abluminal end was not seen and tight junctions were not disrupted. Normotensive rats pretreated with colchicine showed no alteration in cerebrovascular permeability to HRP. Colchicine pretreatment attenuated the permeability alterations that were observed in acutely hypertensive rats. This study demonstrates that integrity of endothelial actin filaments is important for maintenance of the blood-brain barrier to protein during steady states since increased permeability occurred in the presence of an actin disrupting agent. The microtubular network had no demonstrable role during steady states; however, disruption of the microtubular network had a protective effect and prevented the development of alterations in permeability to protein in acute hypertension.     

Electron tunnelling in semiconductor heterostructures

A theory of electron tunnelling in GaAsGa_1?xAl_xAsGaAs heterostructures is presented. The theory takes into account the different non-parabolic energy dispersion relations in the two materials. Calculated values of allowed energy levels are also presented for structures used in earlier experiments. Results of optical absorption experiments are found to agree with theory within 1 meV, but the results of double-barrier tunnelling experiments differ from theory by a factor of about 1.5.     

Low cycle fatigue behaviour of Ti-6Al-5Zr-0-5Mo-0-25Si alloy at room temperature

Low cycle fatigue (LCF) behaviour of the near α titanium alloy, Ti-6Al-5Zr-0.5Mo-0.25Si (LT26A), was investigated in the (a + β) as well as β treated conditions at room temperature. LCF tests were carried out under total strain controlled mode in the range of Δε_t/2: from ±0.60% to ±1.40%. The alloy shows cyclic softening in both the conditions. Also it exhibits dual slope Coffin-Manson (C-M) relationship in both the treated conditions.     

Effect of trehalose and lactose as cryoprotectant during freeze‐drying,in vitro gastro‐intestinal transit and survival of microencapsulated freeze‐dried Lactobacillus casei 431 cells

A novel microencapsulation technique for Lactobacillus casei 431 cells was developed, and the bacterial stability was studied. Cryoprotective solutes were incorporated in the encapsulation mix to improve freeze‐drying survival. The losses of viable cells during drying were recorded as 1.7, 0.84 and 0.38 log Colony‐forming units (cfu)/g for control and samples with trehalose and lactose, respectively. During the simulated gastric‐intestinal transit, trehalose and lactose contributed to higher survivals of 3.1 and 3.0 log cfu/g, respectively, in gastric fluid and 1.3 log and 0.9 log cfu/g, respectively, in 1% bile extract solution. Higher temperature storage was found to be detrimental for cell viability.     

Modeling the economics of testing: a DFT perspective

Decision-makers typically make test tradeoffs using models that mainly represent direct costs such as test generation time and tester use. Analyzing a test strategy's impact on other significant factors such as test quality and yield learning requires an understanding of the dynamic nature of the interdomain dependencies of test, manufacturing, and design. Our research centers on modeling the tradeoffs between these domains. To answer the DFT question, we developed the Carnegie Mellon University Test Cost Model, a DFT cost-benefit model, derived inputs to the model for various IC cases with different assumptions about volume, yield, chip size, test attributes, and so forth; and studied DFT's impact on these cases. We used the model to determine the domains for which DFT is beneficial and for which DFT should not be used. The model is a composite of simple cause-and-effect relationships derived from published research. It incorporates many factors affecting test cost, but we don't consider it a complete model. Our purpose is to illustrate the necessity of using such models in assessing the effectiveness of various test strategies     

Functionalization of styrene–butadiene rubber with meta‐pentadecenyl phenol for better processing: A multifunctional additive and renewable resource

Meta‐pentadecenyl phenol, a nonisoprenoid phenolic lipid, is a renewable agricultural resource and also a byproduct of the cashew industry; it is popularly known as cardanol. This study throws light on the grafting of cardanol, which has been established as a multifunctional additive for natural rubber, onto the main‐chain backbone of styrene–butadiene rubber (SBR), a synthetic polymer used to imbibe the multifunctional properties of the former, such as those of a plasticizer, curing promoter, process aid, and antioxidant, into the latter. The grafting was carried out in the solution stage on a trial basis with a peroxide catalyst, and all of the grafting parameters were optimized with a Taguchi methodology. The grafting of cardanol onto the SBR backbone was successfully confirmed by UV–visible spectroscopy, Fourier transform infrared spectroscopy, and NMR analysis. Thermal analysis of the cardanol‐grafted styrene–butadiene rubber (C‐g‐SBR) revealed a higher thermal stability and better plasticizing effect than that those found in the virgin SBR. The rheological properties of the grafted rubber indicated the improvement of the pseudo‐plastic (shear‐thinning) nature compared to that in gum SBR. The unfilled C‐g‐SBR vulcanizates exhibited physicomechanical properties comparable to 5‐phr processing‐oil‐containing SBR [oil‐plasticized styrene–butadiene rubber (OPSBR)] vulcanizates. The carbon‐black‐filled C‐g‐SBR vulcanizates exhibited improved plasticization, a faster curing rate, easy processability, and better physicomechanical properties compared to the 5‐phr OPSBR vulcanizates. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45150.