365 research outputs found

    Enhancing business performance through green human resource management practices: an empirical evidence from Malaysian manufacturing industry

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    Sustainability has come under public policy limelight. Organizations are investing to minimize the impact of environmental degradation to build their image as an environmentally friendly firm, which contributes to their business performance as well. Literature suggests that green organizational indicators are found to be positively related to firm sustainable performance. More specifically green human resource management (GHRM) practices strengthen the firm’s environmental practices and enhance employee morale toward green practices. The paper aims to investigate the impact of GHRM indicators on environmental performance (EP) and business performance (BP)

    Multi-objective optimisation of machine tool error mapping using automated planning

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    Error mapping of machine tools is a multi-measurement task that is planned based on expert knowledge. There are no intelligent tools aiding the production of optimal measurement plans. In previous work, a method of intelligently constructing measurement plans demonstrated that it is feasible to optimise the plans either to reduce machine tool downtime or the estimated uncertainty of measurement due to the plan schedule. However, production scheduling and a continuously changing environment can impose conflicting constraints on downtime and the uncertainty of measurement. In this paper, the use of the produced measurement model to minimise machine tool downtime, the uncertainty of measurement and the arithmetic mean of both is investigated and discussed through the use of twelve different error mapping instances. The multi-objective search plans on average have a 3% reduction in the time metric when compared to the downtime of the uncertainty optimised plan and a 23% improvement in estimated uncertainty of measurement metric when compared to the uncertainty of the temporally optimised plan. Further experiments on a High Performance Computing (HPC) architecture demonstrated that there is on average a 3% improvement in optimality when compared with the experiments performed on the PC architecture. This demonstrates that even though a 4% improvement is beneficial, in most applications a standard PC architecture will result in valid error mapping plan

    Exact Fourier expansion in cylindrical coordinates for the three-dimensional Helmholtz Green function

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    A new method is presented for Fourier decomposition of the Helmholtz Green Function in cylindrical coordinates, which is equivalent to obtaining the solution of the Helmholtz equation for a general ring source. The Fourier coefficients of the Helmholtz Green function are split into their half advanced+half retarded and half advanced-half retarded components. Closed form solutions are given for these components in terms of a Horn function and a Kampe de Feriet function, respectively. The systems of partial differential equations associated with these two-dimensional hypergeometric functions are used to construct a fourth-order ordinary differential equation which both components satisfy. A second fourth-order ordinary differential equation for the general Fourier coefficent is derived from an integral representation of the coefficient, and both differential equations are shown to be equivalent. Series solutions for the various Fourier coefficients are also given, mostly in terms of Legendre functions and Bessel/Hankel functions. These are derived from the closed form hypergeometric solutions or an integral representation, or both. Numerical calculations comparing different methods of calculating the Fourier coefficients are presented

    Satyrium nepalense, a high altitude medicinal orchid of Indian Himalayan region : chemical profile and biological activities of tuber extracts

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    The present study investigated antioxidant and antibacterial activities of 5 different extracts and derived fractions from the S. nepalense tubers. Identification of the most active fractions, their phytochemical characterization, total phenolic and flavonoid contents, and biological activities were also evaluated. Petroleum ether, chloroform, ethyl acetate, methanol, water extracts and methanol fractions were screened for their antibacterial activity at 10, 50 and 100 mg/mL doses against ten Gram-negative and Gram-positive bacterial strains by disc diffusion method. Their total antioxidant activity was measured by DPPH and ABTS assays. Identification of the main compounds was performed by LC-MS/MS. Methanol extract exhibited the highest antioxidant (IC50= 30.79 \u3bcg/mL and 24.53 \u3bcg/mL for DPPH and ABTS, respectively) and antibacterial (MIC 71.5 to > 100 \u3bcg/mL) activities in comparison with the other extracts. Levels of phenolics and flavonoids were also the highest in the same extract, i.e. 19.2 mg GAE/g and 11.20 mg QE/g, respectively. Phytochemical investigation of the active fractions of the methanol extract led to the isolation of gallic acid (19.04 mg/g) and quercetin (23.4 mg/g). Therefore, methanol extract showed an interesting potential for both antioxidant and antibacterial activities, thus deserving attention for future applications in the fields of medicinal plants and food supplements

    Measurement of the Ds lifetime

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    We report precise measurement of the Ds meson lifetime. The data were taken by the SELEX experiment (E781) spectrometer using 600 GeV/c Sigma-, pi- and p beams. The measurement has been done using 918 reconstructed Ds. The lifetime of the Ds is measured to be 472.5 +- 17.2 +- 6.6 fs, using K*(892)0K+- and phi pi+- decay modes. The lifetime ratio of Ds to D0 is 1.145+-0.049.Comment: 5 pages, 2 figures submitted to Phys. Lett.

    Confirmation of the Double Charm Baryon Xi_cc+ via its Decay to p D+ K-

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    We observes a signal for the double charm baryon Xi_cc+ in the charged decay mode Xi_cc+ -> p D+ K- to complement the previously reported decay Xi_cc+ -> Lambda_c K- pi+ in data from SELEX, the charm hadro-production experiment (E781) at Fermilab. In this new decay mode we observe an excess of 5.62 events over an expected background estimated by event mixing to be 1.38+/-0.13 events. The Poisson probability that a background fluctuation can produce the apparent signal is less than 6.4E-4. The observed mass of this state is (3518+/-3)MeV/c^2, consistent with the published result. Averaging the two results gives a mass of (3518.7+/-1.7)MeV/c^2. The observation of this new weak decay mode confirms the previous SELEX suggestion that this state is a double charm baryon. The relative branching ratio Gamma(Xi_cc+ -> pD+K-)/Gamma(Xi_cc+ -> Lambda_c K- pi+) = 0.36+/-0.21.Comment: 11 pages, 6 included eps figures. v2 includes improved statistical method to determine significance of observation. Submitted to PL

    Production of e+ee^+e^- Pairs Accompanied by Nuclear Dissociation in Ultra-Peripheral Heavy Ion Collision

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    We present the first data on e+ee^+e^- pair production accompanied by nuclear breakup in ultra-peripheral gold-gold collisions at a center of mass energy of 200 GeV per nucleon pair. The nuclear breakup requirement selects events at small impact parameters, where higher-order corrections to the pair production cross section should be enhanced. We compare the pair kinematic distributions with two calculations: one based on the equivalent photon approximation, and the other using lowest-order quantum electrodynamics (QED); the latter includes the photon virtuality. The cross section, pair mass, rapidity and angular distributions are in good agreement with both calculations. The pair transverse momentum, pTp_T, spectrum agrees with the QED calculation, but not with the equivalent photon approach. We set limits on higher-order contributions to the cross section. The e+e^+ and ee^- pTp_T spectra are similar, with no evidence for interference effects due to higher-order diagrams.Comment: 6 pages with 3 figures Slightly modified version that will appear in Phys. Rev.
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