MoSe2 nanoflowers as a counter electrode for quantum dots sensitized solar cells

Journal of Materials Science: Materials in Electronics - Layered transition metal dichalcogenides hold tunable and promising photoelectrochemical properties. MoSe2 is a potential candidate of the...     

Assessment of toxic content in Balanites aegyptiaca seed cake and use of enzymatic-catalysed biodiesel in diesel engine

The present study deals with the estimation of toxic phorbol esters in Balanites aegyptiaca seed cake and to evaluate the performance and combustion characteristics of different blends of biodiesel in a diesel engine. The seeds were manually collected from arid regions of Rajasthan, India and the oil extracted from the powdered kernel with Solvent extraction process. The extracted oil processed by enzymatic catalytic reactions are carried out at optimum operating conditions such as the molar ratio of 8:1 (methanol:oil), reaction temperature at 40°C for 4?h reaction time and xylanase 1% based on oil weight. The total conversion rate of extracted oil to methyl ester by enzymatic reactions yields up to 98.3%. The toxic content of seed cake was determined by high-performance liquid chromatography (HPLC, Shimadzu). The performance and combustion parameters such as BP, BTE and CP decreased, whereas BSFC and DP increased with biodiesel blends.     

Strictly periodic scheduling in IMA-based architectures

The avionic industry has recently adopted the Integrated Modular Avionics (IMA). Such architectures allow the execution of avionic functions on a shared computing platform while avoiding any interference between them. This is done through hard memory and temporal segregation constraints. Although IMA reduces the weight and the power consumption and shortens the design-cycle times, it gives rise to a complex multiprocessor scheduling problem. One of the key difficulties of this problem is related to the strict periodicity of tasks, which means that the time separating two successive executions of the same task is strictly equal to the associated period. In order to help the system designer in producing a proper schedule, an exact formulation based on Integer Linear Programming and a heuristic inspired from Game Theory are proposed. To enhance the solution quality of the heuristic, a?multi-start method, which gives some probabilistic guarantees on the optimality of the solutions, is also introduced.     

Environmentally persistent free radicals induce airway hyperresponsiveness in neonatal rat lungs

Background  

Increased asthma risk/exacerbation in children and infants is associated with exposure to elevated levels of ultrafine particulate matter (PM). The presence of a newly realized class of pollutants, environmentally persistent free radicals (EPFRs), in PM from combustion sources suggests a potentially unrecognized risk factor for the development and/or exacerbation of asthma.     

An experimental study on the shattering behavior of a high strength armour steel under blast and long rod penetrator impact

Armour steel plates with drilled holes are filled with explosive and subjected to single or multiple blasts to induce shattering. The critical diameter for shattering under explosive detonation, found from the experiments matches closely with that of the long rod penetrator impacted plates. The damage pattern and fracture surface of the tested samples under blast effect have been compared with plates impacted with long rod penetrators for matching the observed shattering behavior. Difference in the shattering behavior of the armour steel subjected to single and multiple blasts has also been presented.     

Some experimental studies on angle effect in penetration

This investigation describes and analyses the experimental results pertinent to the penetration of Al-7017 plates with non-deformable steel projectiles at a velocity of 840 ± 15 m/s at different angles of impact. The results include the variation in damage pattern, damage area at front and back, mid penetration channel observations, residual velocity and energy absorption capacities at different obliquities. Some observations relating to the adiabatic shear bands formation have also been presented. The micro hardness values along the path of penetration have been studied in order to understand the increase in energy absorption at oblique impact. The experimental data shows a transition of failure mode from an adiabatic shear band induced shear plugging at lower obliquities to a more homogeneous deformation of the target material and gouging at higher obliquities.     

Closed-Form Solution for System Availability Distribution

Highly reliable systems with long mission time, that can tolerate no down time, have motivated the study of system reliability. The emergence of fault-tolerant computing systems, where small down times may be tolerable, and preventive and corrective maintenance permitted, motivates a revisit to measures like mean availability. Vendors of computer systems are being required to specify the level of availability that will be met by their systems over a finite time interval, and pay a penalty for non-compliance. Since no closed-form solution has been reported in the literature, numerical approaches have often been used to compute systems availability over a finite time, even for simple Markov models. We report a Laplace transform solution for the distribution of availability over a finite interval, for a semi-Markov model. The transform of the distribution is analytically inverted to obtain a closed-form solution for the corresponding Markov model.     

Support vector regression for determining the minimum zone sphericity

Several methods have been investigated to determine the deviation of manufactured spherical parts from ideal geometry. One of the most popular is the least squares technique, which is still widely employed in coordinate measuring machines used by industries. The least squares algorithm is optimal under the assumption that the data set is very large and has the inherent disadvantage of overestimating the minimum tolerance zone, resulting sometimes in the rejection of good parts. In addition, it requires that the data be distributed normally. The support vector regression approach alleviates the necessity for these assumptions. While most fitting algorithms in practice today require that the sampled data accurately represent the surface being inspected, support vector regression provides a generalization over the surface. We describe how the concepts of support vector regression can be applied to the determination of tolerance zones of nonlinear surfaces; to demonstrate the unique potential of support vector machine algorithms in the area of coordinate metrology. In specific, we address part quality inspection of spherical geometries.     

Shape design sensitivity analysis via material derivative-adjoint variable technique for 3-D and 2-D curved boundary elements

A general approach to shape design sensitivity analysis of three- and two-dimensional elastic solid objects is developed using the material derivative-adjoint variable technique and boundary element method. The formulation of the problem is general and first-order sensitivities in the form of boundary integrals for the effect of boundary shape variations are derived for an arbitrary performance functional. Second-order quadrilateral surface elements (for 3-D problems) and quadratic boundary elements (for 2-D problems) are employed in the solution of primary and adjoint systems and discretization of the boundary integral expressions for sensitivities. The accuracy of sensitivity information is studied for selected global performance functionals and also for boundary state fields at discrete points. Numerical results are presented to demonstrate the accuracy and efficiency of this approach.     

Mechanisms and empirical equations for deformation and some principles of alloy design

Some aspects of the deformation behaviour of solids at very high, moderately high and low strain rates are discussed. In the very high strain rate region, deformation equations and the physics of the shock front are analysed to propose a route to lower energy dissipation at the shock front. In the moderately high strain rate region, alloy design principles for maximizing the deformation resistance are outlined. In the low strain rate region, an analysis of the physical basis for the power law creep equation is presented. Some physical arguments are presented as a rationale for the high stress exponents and activation energies often observed in particle-strengthened alloys. The additivity of strain rates by various mechanisms is also briefly discussed.