Superconducting State Parameters of (Ni33Zr67)1?xMx (M = Ti, V, Co, Cu) Ternary Amorphous Superconductors

The theoretical investigations of the superconducting state parameters (SSP) viz. electron-phonon coupling strength λ, Coulomb pseudopotential μ ^∗, transition temperature T _C , isotope effect exponent α and effective interaction strength N _O V of (Ni₃₃Zr₆₇)_1−x M _x (M=Ti,V,Co,Cu) ternary amorphous superconductors have been reported using Ashcroft’s empty core (EMC) model potential. Five different types of local field correction functions proposed by Hartree (H), Taylor (T), Ichimaru-Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are used in the present investigation to study the screening influence on the aforesaid properties. The T _C obtained from Sarkar et al. (S) local field correction function are found in excellent agreement with available theoretical data. Quadratic T _C equation has been proposed, which provides successfully the T _C values of ternary amorphous alloys under consideration. Also, the present results are found to be in qualitative agreement with other such earlier reported data, which confirms the superconducting phase in the superconductors.     

Biaxial tensile behavior of spunbonded nonwoven geotextiles

Geotextiles can be successfully employed for any geotechnical application when they are able to sustain pre-defined levels of tensile stresses. The biaxial tensile test has an advantage over other tensile test methods in that it does not allow “necking” during deformation which simulates the operational conditions of geotextiles under confined stresses. In this study, the model for uniaxial tensile behavior of nonwovens has been modified to investigate the biaxial tensile behavior of spunbonded geotextiles. The model has included the effect of fiber re-orientation, stress-strain behavior of constituent fibers, and physical characteristics of nonwovens when the geotextile specimen is laterally constrained. A comparison is made between predicted and experimental stress-strain curves obtained from previous work (Bais-Singh and Goswami, 1998). Theoretical findings of biaxial tensile behavior obtained using the layer theory are also critically discussed. In addition, it has been revealed that fiber re-orientation is a key factor in translating the random spunbonded nonwoven geotextiles to anisotropic structures under defined biaxial tensile stresses.     

An undergraduate system-on-chip (SoC) course for computer engineering students

The authors have developed a senior-level undergraduate system-on-chip (SoC) course at San Jose State University, San Jose, CA, that emphasizes SoC design methods and hardware-software codesign techniques. The course uses a "real world" design project as the teaching vehicle and implements an SoC platform to control a five-axis robotic arm using Altera's state-of-the-art Excalibur chip. The Excalibur chip contains both ARM Corporation's embedded processor and a programmable logic device (PLD) array. The course goes through a complete hardware-software codesign flow from implementing custom hardware devices on a PLD to developing an embedded algorithm in a state-of-the-art design environment for a complete SoC solution. Students learn the Quartus II design environment by examining the sample design files in Altera's EXPA1 development kit and following the step-by-step instructions toward creating a simple embedded application. After this familiarization process, students define the architectural specifications of a memory-mapped servo controller, implement it in the Excalibur's PLD array, and interface this device with the ARM processor's internal bus to control each robotic arm servo. Functional regression tests and post-synthesis timing verification steps are applied to the servo controller following the implementation phase. Subsequently, students integrate the servo controller with the rest of the system and perform board-level functional verification tests to observe whether the robotic arm can move an object from a source to a destination point accurately. Students also develop an embedded algorithm, which translates user inputs in Cartesian coordinates into robotic arm movements in spherical coordinates during laboratory sessions.     

Effect of ash on maximum thickness of plastic layer of coals

A study of the effect of ash yield on the maximum thickness of the plastic layer (MTPL) of some coking coals (as measured by the Sapozhnikov plastometer) has revealed that with an increase in the former the latter in general decre?es. A rectilinear relation approximately exists between the ash percentage (dry basis) and log MTPL values of coals. For the samples studied, a multiple correlation incorporating the rank factor was found to be unnecessary. Higher Fe₂O₃ and SO₃ contents from the coal were found to be associated with higher MTPL values.     

Structuring Optimizing Transformations and Proving Them Sound

A compiler optimization is sound if the optimized program that it produces is semantically equivalent to the input program. The proofs of semantic equivalence are usually tedious. To reduce the efforts required, we identify a set of common transformation primitives that can be composed sequentially to obtain specifications of optimizing transformations. We also identify the conditions under which the transformation primitives preserve semantics and prove their sufficiency. Consequently, proving the soundness of an optimization reduces to showing that the soundness conditions of the underlying transformation primitives are satisfied.The program analysis required for optimization is defined over the input program whereas the soundness conditions of a transformation primitive need to be shown on the version of the program on which it is applied. We express both in a temporal logic. We also develop a logic called temporal transformation logic to correlate temporal properties over a program (seen as a Kripke structure) and its transformation.An interesting possibility created by this approach is a novel scheme for validating optimizer implementations. An optimizer can be instrumented to generate a trace of its transformations in terms of the transformation primitives. Conformance of the trace with the optimizer can be checked through simulation. If soundness conditions of the underlying primitives are satisfied by the trace then it preserves semantics.     

Superconducting State Parameters of 5d-Transition Metals Based Binary Alloys

The theoretical study of the superconducting state parameters (SSP) viz. electron–phonon coupling strength λ, Coulomb pseudopotential μ ^*, transition temperature T _C , isotope effect exponent α and effective interaction strength N _O V of 5d-transition metals based binary alloys have been made extensively in the present work using a model potential for the first time. A considerable influence of various exchange and correlation functions on λ and μ ^* is found from the present study. The present results of the SSP are found in qualitative agreement with the available experimental data wherever it exists.     

On simultaneous on-line state and parameter estimation in non-linear state-space models

On-line estimation plays an important role in process control and monitoring. Obtaining a theoretical solution to the simultaneous state-parameter estimation problem for non-linear stochastic systems involves solving complex multi-dimensional integrals that are not amenable to analytical solution. While basic sequential Monte-Carlo (SMC) or particle filtering (PF) algorithms for simultaneous estimation exist, it is well recognized that there is a need for making these on-line algorithms non-degenerate, fast and applicable to processes with missing measurements. To overcome the deficiencies in traditional algorithms, this work proposes a Bayesian approach to on-line state and parameter estimation. Its extension to handle missing data in real-time is also provided. The simultaneous estimation is performed by filtering an extended vector of states and parameters using an adaptive sequential-importance-resampling (SIR) filter with a kernel density estimation method. The approach uses an on-line optimization algorithm based on Kullback–Leibler (KL) divergence to allow adaptation of the SIR filter for combined state-parameter estimation. An optimal tuning rule to control the width of the kernel and the variance of the artificial noise added to the parameters is also proposed. The approach is illustrated through numerical examples.     

Modeling Intermittent Drying of Wood under Rapidly Varying Temperature and Humidity Conditions with the Lumped Reaction Engineering Approach (L-REA)

For improving product quality and minimizing energy consumption during drying, intermittent drying is often recommended. The mathematical models that are used to describe intermittent drying are usually transport phenomena based, complex models. In this study, the lumped reaction engineering approach (L-REA) is implemented to model wood drying under rapid periodically changed drying air temperature and humidity with high number of cycles of intermittency. The equilibrium activation energy (ΔE _v,b ), an important parameter for REA approach, is evaluated according to the corresponding drying air temperature and humidity in each drying section. The results of modeling suggest the L-REA works well with the experimental data. The simplicity of the L-REA is obvious and is hoped to be used in an industrial setting more readily. The L-REA can be used for sustainable processing in industries to assist in energy audit and management.