2,868 research outputs found
Superconductivity in 2-2-3 system Y2Ba2Cu2O(8+delta)
Researchers synthesized a new high T(sub c) 2-2-3 superconductor Y2Ba2Cu3O(8+delta) by a special preparation technique and characterized it by ac-susceptibility measurements. Diamagnetism and Meissner effect sets in at low fields and superconducting transition onsets at 90 K. The systematic investigation of the real and imaginary components of ac-susceptibility as a function of temperature and applied ac magnetic field reveals that the magnetic behavior is that of a granular type superconductor
Development of an empirically based dynamic biomechanical strength model
The focus here is on the development of a dynamic strength model for humans. Our model is based on empirical data. The shoulder, elbow, and wrist joints are characterized in terms of maximum isolated torque, position, and velocity in all rotational planes. This information is reduced by a least squares regression technique into a table of single variable second degree polynomial equations determining the torque as a function of position and velocity. The isolated joint torque equations are then used to compute forces resulting from a composite motion, which in this case is a ratchet wrench push and pull operation. What is presented here is a comparison of the computed or predicted results of the model with the actual measured values for the composite motion
Evaluating the Effect of Employee Stock Option Plans on the Financial Performance of Indian Construction & Infrastructure Companies
Competitive pressures to improve productivity continue to place significant demand upon organizations globally. To respond to these competitive pressures with the developed countries like USA, ESOPs (Employee Stock Ownership Plans) have also been adopted in developing country like India to increase the firm’s and employee’s performance and productivity by retaining the employees to a large extent. Employee Stock Ownership Plans are majorly utilized by many successful and competent companies across the world. The successes of the ESOP companies in countries like USA, Japan and UK etc. may largely be attributed to enhancement of firm’s performance and Employee productivity. These effects are becoming increasingly noticed across the world in recent years. Thus, this research is an empirical study carried out to evaluate the impact of ESOP on financial performance of ten listed Indian Construction and Infrastructural companies based on for a period of six years. The study analyzes three years pre and post period to the adoption of ESOPs for the selected companies and is based upon secondary data collected from company annual reports of the respective years. Company-wise Pre- and Post- ESOP adoption Analysis and Regression Analysis is carried out in the selected selector
() spectroscopy using Cornell potential
The mass spectra and decay properties of heavy quarkonia are computed in
nonrelativistic quark-antiquark Cornell potential model. We have employed the
numerical solution of Schr\"odinger equation to obtain their mass spectra using
only four parameters namely quark mass (, ) and confinement strength
(, ). The spin hyperfine, spin-orbit and tensor
components of the one gluon exchange interaction are computed perturbatively to
determine the mass spectra of excited , , and states. Digamma,
digluon and dilepton decays of these mesons are computed using the model
parameters and numerical wave functions. The predicted spectroscopy and decay
properties for quarkonia are found to be consistent with available experimental
observations and results from other theoretical models. We also compute mass
spectra and life time of the meson without additional parameters. The
computed electromagnetic transition widths of heavy quarkonia and mesons
are in tune with available experimental data and other theoretical approaches
Optimization of vibration amplitude ratio of face mill tool of VMC and analysis with design expert to endorsing shim design
This paper presents the concept, design and development of shim (passive damper) to improve the stability for high spindle speed machine operation of face mill tool. The objective of this paper is to learning the dynamic behavior of a face mill tool on VMC with dissimilar types of shims which cover investigation of dynamic motion behavior of the face mill tool, the behavior of different types of shim design and behavior of vibration by using the amplitude ratio method and analysis by a Design Expert. Research work supported computational analysis with Ansys, 35 VMC experimental records and analyzed by ANOVA/Design Expert with different type of shims to observe a dynamic behavior of chatter. It include of the effect of process parameters like Cutting speed (250,200,150 m/min), feed per tooth (0.05, 0.1, 0.15mm/tooth), depth of cut (1.2 mm, 1.0 mm, 0.8 mm), and different types of materials (shims) for face mill tool on VMC, for analyzing the responses like amplitude ratio in X – direction, Y- direction with ANOVA and optimizing for AISI 2062 steel by Design Expert. An experimental methodology was developed using the DOE (Design of experiment) technique. The optimum factorial method was used to design an orthogonal array of four factors having three levels. Here, the main results are based on amplitude ratio, ANOVA analysis and optimization. ANOVA was used to decide the effects of the machining parameters on the vibration amplitude ratio in X; and vibration amplitude ratio in Y. This is useful for evaluating the stability of milling operations via time domain FFT and analyzed by ANOVA. Data are validated by 35 sets of VMC experiments. Physical 35 experiments may be not enough in a view of high level researchers, academicians and industrialist to conclude the use of shim and it need in face mill tool on VMC. Hence here optimization based on optimum factorial method is executed using Design Expert software in which 35experiments and its iterations with 70 populations were used to run the program. It is found that the most critical parameter in this study is the material of Shim. At high cutting parameters carbide shim, at low and medium cutting parameters SS shim are given better results by ANOVA and Optimization of Design Expert also validated by 35 sets of VMC experiments. Hence these shim designs endorse versatile solutions
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