Coupled-channels Faddeev AGS calculation of K−ppnK^{-}ppn and K−pppK^{-}ppp quasi-bound states

Using separable $\bar{K}N-\pi\Sigma$ potentials in the Faddeev equations, we calculated the binding energies and widths of the $K^{-}pp$, $K^{-}ppn$ and $K^{-}ppp$ quasi-bound states on the basis of three- and four-body Alt-Grassberger-Sandhas equations in the momentum representation. One- and two-pole version of $\bar{K}N-\pi\Sigma$ interaction are considered and the dependence of the resulting few-body energy on the two-body $\bar{K}N-\pi\Sigma$ potential was investigated. The $s$-wave [3+1] and [2+2] sub-amplitudes are obtained by using the Hilbert-Schmidt expansion procedure for the integral kernels. As a result, we found a four-body resonance of the $K^{-}ppn$ and $K^{-}ppp$ quasi-bound states with a binding energy in the range $B_{K^{-}ppn}\sim{55-70}$ and $B_{K^{-}ppp}\sim{90-100}$ MeV, respectively. The calculations yielded full width of $\Gamma_{K^{-}ppn}\sim{16-20}$ and $\Gamma_{K^{-}ppp}\sim{7-20}$ MeV.Comment: 16 pages, 4 figure

Multiple exciton generation in isolated and interacting silicon nanocrystals

An important challenge in the field of renewable energy is the development of novel nanostructured solar cell devices which implement low-dimensional materials to overcome the limits of traditional photovoltaic systems. For optimal energy conversion in photovoltaic devices, one important requirement is that the full energy of the solar spectrum is effectively used. In this context, the possibility of exploiting features and functionalities induced by the reduced dimensionality of the nanocrystalline phase, in particular by the quantum confinement of the electronic density, can lead to a better use of the carrier excess energy and thus to an increment of the thermodynamic conversion efficiency of the system. Carrier multiplication, i.e. the generation of multiple electron-hole pairs after absorption of one single high-energy photon (with energy at least twice the energy gap of the system), can be exploited to maximize cell performance, promoting a net reduction of loss mechanisms. Over the past fifteen years, carrier multiplication has been recorded in a large variety of semiconductor nanocrystals and other nanostructures. Owing to the role of silicon in solar cell applications, the mission of this review is to summarize the progress in this fascinating research field considering carrier multiplication in Si-based low-dimensional systems, in particular Si nanocrystals, both from the experimental and theoretical point of view, with special attention given to the results obtained by ab initio calculations

Smoothed particle hydrodynamics for galaxy formation simulations: improved treatments of multiphase gas, of star formation and of supernovae feedback

We investigate a new implementation of the Smoothed Particle Hydrodynamics technique (SPH) designed to improve the realism with which galaxy formation can be simulated. In situations where cooling leads to the coexistence of phases of very different density and temperature, our method substantially reduces artificial overcooling near phase boundaries, prevents the exclusion of hot gas from the vicinity of cold ``clouds'', and allows relative motion of the two phases at each point. We demonstrate the numerical stability of our scheme in the presence of extremely steep density and temperature gradients, as well as in strong accretion shocks and cooling flows. In addition, we present new implementations of star formation and feedback which simulate the effect of energy injection into multiphase gas more successfully than previous schemes. Our feedback recipes deposit thermal energy separately in cold dense gas and hot diffuse gas, and can explicitly reinject cold gas into the hot phase. They make it possible to damp star formation effectively, to reheat cold gas, and to drive outflows into the galaxy halo and beyond. We show feedback effects to be strongest in small mass objects where much of the gas can be expelled. After idealised tests, we carry out a first low resolution study of galaxy formation in a $\Lambda$CDM universe. Feedback results in substantial and mass-dependent reductions in the total baryonic mass gathered onto the final object as well as in significant modulation of the star formation history.Comment: 41 pages, 8 figures. Submitted to MNRA

Weighing simulated galaxy clusters using lensing and X-ray

We aim at investigating potential biases in lensing and X-ray methods to measure the cluster mass profiles. We do so by performing realistic simulations of lensing and X-ray observations that are subsequently analyzed using observational techniques. The resulting mass estimates are compared among them and with the input models. Three clusters obtained from state-of-the-art hydrodynamical simulations, each of which has been projected along three independent lines-of-sight, are used for this analysis. We find that strong lensing models can be trusted over a limited region around the cluster core. Extrapolating the strong lensing mass models to outside the Einstein ring can lead to significant biases in the mass estimates, if the BCG is not modeled properly for example. Weak lensing mass measurements can be largely affected by substructures, depending on the method implemented to convert the shear into a mass estimate. Using non-parametric methods which combine weak and strong lensing data, the projected masses within R200 can be constrained with a precision of ~10%. De-projection of lensing masses increases the scatter around the true masses by more than a factor of two due to cluster triaxiality. X-ray mass measurements have much smaller scatter (about a factor of two smaller than the lensing masses) but they are generally biased low by 5-20%. This bias is ascribable to bulk motions in the gas of our simulated clusters. Using the lensing and the X-ray masses as proxies for the true and the hydrostatic equilibrium masses of the simulated clusters and averaging over the cluster sample we are able to measure the lack of hydrostatic equilibrium in the systems we have investigated.Comment: 27 pages, 21 figures, accepted for publication on A&A. Version with full resolution images can be found at http://pico.bo.astro.it/~massimo/Public/Papers/massComp.pd

A STUDY ON CLOUD COMPUTING EFFICIENT JOB SCHEDULING ALGORITHMS

cloud computing is a general term used to depict another class of system based computing that happens over the web. The essential advantage of moving to Clouds is application versatility. Cloud computing is extremely advantageous for the application which are sharing their resources on various hubs. Scheduling the errand is a significant testing in cloud condition. Typically undertakings are planned by client prerequisites. New scheduling techniques should be proposed to defeat the issues proposed by organize properties amongst client and resources. New scheduling systems may utilize a portion of the customary scheduling ideas to consolidate them with some system mindful procedures to give answers for better and more effective employment scheduling. Scheduling technique is the key innovation in cloud computing. This paper gives the study on scheduling calculations. There working regarding the resource sharing. We systemize the scheduling issue in cloud computing, and present a cloud scheduling pecking order

Active and stable methane oxidation nano-catalyst with highly-ionized palladium species prepared by solution combustion synthesis

We report on the synthesis and testing of active and stable nano-catalysts for methane oxidation. The nano-catalyst was palladium/ceria supported on alumina prepared via a one-step solution-combustion synthesis (SCS) method. As confirmed by X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HTEM), SCS preparative methodology resulted in segregating both Pd and Ce on the surface of the Al 2 O 3 support. Furthermore, HTEM showed that bigger Pd particles (5 nm and more) were surrounded by CeO 2 , resembling a core shell structure, while smaller Pd particles (1 nm and less) were not associated with CeO 2 . The intimate Pd-CeO 2 attachment resulted in insertion of Pd ions into the ceria lattice, and associated with the reduction of Ce 4+ into Ce 3+ ions; consequently, the formation of oxygen vacancies. XPS showed also that Pd had three oxidation states corresponding to Pd0, Pd 2+ due to PdO, and highly ionized Pd ions (Pd (2+x)+ ) which might originate from the insertion of Pd ions into the ceria lattice. The formation of intrinsic Ce 3+ ions, highly ionized (Pd2+ species inserted into the lattice of CeO 2 ) Pd ions (Pd (2+x)+ ) and oxygen vacancies is suggested to play a major role in the unique catalytic activity. The results indicated that the Pd-SCS nano-catalysts were exceptionally more active and stable than conventional catalysts. Under similar reaction conditions, the methane combustion rate over the SCS catalyst was ~18 times greater than that of conventional catalysts. Full methane conversions over the SCS catalysts occurred at around 400 C but were not shown at all with conventional catalysts. In addition, contrary to the conventional catalysts, the SCS catalysts exhibited superior activity with no sign of deactivation in the temperature range between ~400 and 800 C. 2018 by the authors. Licensee MDPI, Basel, Switzerland.Acknowledgments: This paper was made possible by an NPRP Grant #6-290-1-059 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Achieving excellence in services: an empirical study in the UAE banking sector.

Banking services are perhaps the largest industry that caters to -the needs of various segments of the population reflecting the diverse Diasporas of the society. Moreover, perceived service quality tends to play a significant role in high involvement (high interaction between customers and service providers) industries like banks. Also, banks often have long-term business relationships with customers. In addition, the banking sector is large enough to capture and represent almost all the critical features of the customer-perceived service quality and the critical dimensions of excellence that the management may have to encounter, in order to effectively manage a service organisation. . However, there is considerable lack of literature with respect to service industry management, especially in the banking industry of developing economies. Therefore an analysis of banks in the UAE from a 'service-quality perspective' may sound interesting at this juncture. Such an investigation is vital for the bankers in order to enhance their business performance. The main objective of this research is to develop a theoretical framework to understand and explore CSFs for banks that succeed in the field of TQM and to identify marketoriented activities that are affected by the use of this approach. This research adapts an interdisciplinary approach that makes use of TQM, service quality, IT, and information systems literature. It takes a holistic view of TQM in the banking sector and considers the different stages of implementation and implications of the TQM. The research design involves a combination of quantitative and qualitative methodologies to incorporate: (1) TQM development; (2) the identification of key TQMsuccess factors commonly cited in the literature, and endorsed by practitioners and experts as important to effective TQM implementation; (3) an in-depth case studies. approach to understand how TQM processes, and critical success factors identified are addressed and implemented; and (4) the possible impact of TQM practices on efficiency. Furthermore, the research framework, which emerged from the literature search, is tested and validated by rigorous quantitative analysis using SPSS. The statistical analysis using Factor Analysis, Regression Analysis, One-Sample Test and Ranking Analysis to test a series of relationships and research constructs to provide solid support for the resulting relationships. i The study has identified twelve CSFs for the successful implementation of TQM: (1) Top Management Support, (2) Strategy, (3) Continuous Improvement, (4) Benchmarking, (5) Customer Focus, (6) Quality Department, (7) Human Resource Management, (8) Quality Technology,. (9) Service Design, (10) Employees, (11) Servicescapes, (12) Quality Systems. Furthermore, it *has been found that the organisational experiences of TQM implementation in-the service- sector in UAE are far from being mature. There is a lot of evidence with reference to the survey results and case studies presented in this study that TQM is still a new management concept, and is widely unknown. In many cases, there is some reluctance to introduce it. . The study has pointed out the CSFs for successful TQM implementation because it is vital for organisations to capture the minds of everybody, starting at the top and permeating throughout the whole organisation and beyond. The philosophy maintains that an organisation's primary objective is to enhance its ability to meet customer requirements by improving the quality of its services. People are the most important management resource and ultimate goal of business. TQM generally means a quest for excellence, creating the right attitudes and controls to make prevention of any possible errors, and optimise customer satisfaction by increased efficiency and effectiveness. Further, this study points out TQM as being an organisation-wide activity which has to reach every employee. Therefore, TQM has been an. approach for continuously improving the quality of services delivered through the participation at all levels and functions of the organisation. From this study, it is evident that the effectivetransformation to TQM has been linked to the extent to which firms implement certain CSFs. This study contributes to the emerging literature on TQM in banking sector in a number of specific ways: (1) It provides new theoretical grounds for studying TQM in banking sector in the context of CSFs that affect competition in the dynamic marketplace; (2) It computes and analyses the total quality management indices with respect to the 16 factors which have been developed from the literature for the banking industry as a whole; (3) It ascertains the level of TQM implementation in the UAE banking scene; (4) It Offers key insights on the criticality of the different TQM dimensions with respect to the banking sector in UAE and (5) It provides a foundation and proposals for future research and investigation