Interferometric study of porous metal bearings

Imperial Users onl

Necessity for quantum coherence of nondegeneracy in energy flow

In this work, we show that the quantum coherence among non-degenerate energy subspaces (CANES) is essential for the energy flow in any quantum system. CANES satisfies almost all of the requirements as a coherence measure, except that the coherence within degenerate subspaces is explicitly eliminated.We show that the energy of a system becomes frozen if and only if the corresponding CANES vanishes, which is true regardless of the form of interaction with the environment. However, CANES can remain zero even if the entanglement changes over time. Furthermore, we show how the power of energy flow is bounded by the value of CANES. An explicit relation connecting the variation of energy and CANES is also presented. These results allow us to bound the generation of system-environment correlation through the local measurement of the system's energy flow

Pengaruh Inovasi Dan Iklim Organisasi Terhadap Kinerja Perusahaan Dengan Sistem Pengendalian Manajemen Sebagai Variabel Moderasi

This research was conducted to determine the effect of innovation, organizational climate, and the moderation system management control of the company's performance. This study population is the company authorized the existing auto repair shop in Palembang and the sample was middle-level managers who work in the company is. The technique of determining the sample using purposive sampling. The research was conducted using multiple regression analysis. Of the 65 questionnaires distributed, obtained 62 respondents who are willing to fill. The results show that innovation does not affect the company's performance, organizational climate does not affect the company's performance, management control system did not moderate the relationship between innovation on corporate performance, and management control systems did not moderate the relationship between organizational climate on the performance of the company. The results of this study is expected to be useful as a reference for future studies

Hydrodechlorination reactions on silica-supported rhodium catalysts

The objectives of this study were to investigate the pathways of the hydrodechlorination reactions over silica-supported Rh catalysts as well as identify selectivities and deactivation properties. Reaction of 1,2-dichloroethane with hydrogen over Rh/SiO2 catalyst was studied in the temperature range 200 to 300°C. Formation of two intermediates was proposed while 1,2-dichloroethane was adsorbed on the catalyst, the reactive intermediates then produce ethane, ethylene, chloroethane and methane. From the methane formation, it was inferred that the ethane hydrogenolysis occured over the Rh/SiO2 catalysts. Higher conversion to C1 and C2 hydrocarbons was observed at higher reaction temperature. The activation energy was found to be 13 Kcal/mole. Hydrodechlorination of trichloroethylene was studied to gain information on controlling parameters to manage trichloroethylene pollution emissions in vapor-degreasing applications. Reaction temperature above 150°C, longer contact time, and reactant partial pressure below 100 torr effectively promoted the conversion to hydrocarbon formation. The activation energy was 13.9 Kcal/mole. The data showed that two Cl atoms on the α( carbon did not need to be removed simultaneously during the reaction. The deactivation on Rh/SiO2 catalyst was also studied. A comparion of the ethylene hydrogenation on fresh and contaminated catalysts (after reaction with 1,1-dichloro-ethane) showed a negative effect on the product selectivity to ethane formation, for the deactivated catalyst. The varied selectivity for CH4 and C2H6 demonstrated that at least two distinct types of active sites existed on the catalyst surface

Optimal joint trajectory planning for a robot with elastic links

The optimal joint angle trajectory planning of light-weight flexible manipulator is investigated based on the cycloidal motions of each joint. The objective of the optimization is the minimization of link tip vibrations during and after joint motion, and the design variables are the inflection or switch point of the cycloidal motion; The Lagrangian equations are used to derive the dynamic equations of motion and the Assumed-modes method is used for numerical solution. The proposed optimum joint angle trajectory can be implemented by off-line programming for the minimum vibration of robot arms; One and two flexible links cases are investigated and computer simulation is performed for different payloads and manipulator configurations

Solution of Differential Equations with Applications to Engineering Problems

Over the last hundred years, many techniques have been developed for the solution of ordinary differential equations and partial differential equations. While quite a major portion of the techniques is only useful for academic purposes, there are some which are important in the solution of real problems arising from science and engineering. In this chapter, only very limited techniques for solving ordinary differential and partial differential equations are discussed, as it is impossible to cover all the available techniques even in a book form. The readers are then suggested to pursue further studies on this issue if necessary. After that, the readers are introduced to two major numerical methods commonly used by the engineers for the solution of real engineering problems

Synthesis and Characterization of Atomically Dispersed, Vanadosilicate Catalysts in Si8O20-Based Building Block Solids

Silica supported vanadium complexes have attracted interest as catalysts for a variety of catalytic reactions in the past two decades. Although many strategies have been developed for incorporating vanadyl species on silica surfaces, controlling dispersion and loading while simultaneously producing single site catalysts remains a challenging goal in this context and in catalysis as well. A simple strategy for producing single-site and site-isolated vanadyl species has been explored which allows for control of both the connectivity to the support as well as the local surface structure around a V=O group. The main elements of this strategy involve construction of the support from silicate building blocks linked by groups that both hold the matrix together and act as catalytically active sites. Controlled sequential dosing lead to catalysts in which control of the identity of the sites, their connectivity to the support and dispersion is maintained. The specific system that will be described involves the controlled reaction of vanadyl chloride (VOCl3) and vanadium tetrachloride (VCl4) with the tin functionallized spherosilicate cube, (SnMe3)8Si8O20. Labeled 17O (SnMe3*O)8Si8O12 and (Cl3Si)8Si8O20 molecule have also been synthesized successfully by using totally new synthetic methodologies. The physico-chemical properties of these vanadium catalysts were characterized by solid state 51V and 17O NMR, gravimetric analysis, EXAFS, and atomic absorption spectroscopy. A quick survey of isopropanol dehydration and dehydrogenation with these vanadium (IV and V) catalysts has been studies. The acid-base property of these single-site and site-isolated catalysts has been assessed by the conversion of isopropanol. Preliminary results of highly selectivity (\u3e97%) of isopropanol conversion to propene will be described