2,333 research outputs found

    Ethik in der Ethnologie

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    Perpaduan Serat Daun Nanas (Ananas Comosus) Dan Kitosan Sebagai Material Alat Penangkapan Ikan Ramah Lingkungan (Combination of Pineapple Leaf Fiber and Chitosan for Eco-friendly Fishing Gear Materials)

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    The utilization of pineapple leaf materialfiber for an alternative fishing gear is a step of development to create eco-friendly fishing gear material. The pineapple leaf fib er was observed based on mechanical (breaking strength and elongation value) and physical characteristics (water contents and specific weight) to learn about force of its fiber as natural material for the fishing gear. There were two methods used in this study, such as concentrates factor and soaking time in chitosan. Chitosan concentrates and soaking times in respectively were 1, 1.5, 2% and 15, 30, 45 minutes. The test of mechanical and physical characteristic had been done in Engineering and Design of Wood Building Laboratory, Department of Engineering, Forest Product, Forestry Faculty, Bogor Agricultural University, then for the breaking strength and elongation value used Universal Testing Machine (UTM). The data were analyzed by Completely Randomize Factorial Design (CRFD). The results showed that pineapple leaf fiber consist of 1.095% of water contents and 1.005 for specific weight. Statistical analysis proved that breaking strength value of pineapple leaf fibers was affected by soaking time in chitosan. The best result of the breaking strength test was when the fiber soaked in chitosan with concentrate 1 % during 45 minutes with amount of breaking strength and elongation 34.84 kgf and 0.60 mm

    Reflection of a Lieb-Liniger wave packet from the hard-wall potential

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    Nonequilibrium dynamics of a Lieb-Liniger system in the presence of the hard-wall potential is studied. We demonstrate that a time-dependent wave function, which describes quantum dynamics of a Lieb-Liniger wave packet comprised of N particles, can be found by solving an NN-dimensional Fourier transform; this follows from the symmetry properties of the many-body eigenstates in the presence of the hard-wall potential. The presented formalism is employed to numerically calculate reflection of a few-body wave packet from the hard wall for various interaction strengths and incident momenta.Comment: revised version, improved notation, Fig. 5 adde

    Clostridial Diseases Encountered In Veterinary Medicine

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    Although one of the Clostridial. diseases of animals has been recognized as a distinct entity for 70 years, knowledge concerning disease caused by infections due to this genus of bacteria seems to have lagged somewhat as compared with some of the other bacterial diseases. The reason for this apparent lag is obvious. Symptoms and pathological lesions associated with Clostridial infections usually result from the effects of toxins which enter the blood stream. The fact that the actual site of infection is often quite remote from the site of greatest injury may, of course, be confusing to the investigator

    WARNING: Physics Envy May Be Hazardous To Your Wealth!

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    The quantitative aspirations of economists and financial analysts have for many years been based on the belief that it should be possible to build models of economic systems - and financial markets in particular - that are as predictive as those in physics. While this perspective has led to a number of important breakthroughs in economics, "physics envy" has also created a false sense of mathematical precision in some cases. We speculate on the origins of physics envy, and then describe an alternate perspective of economic behavior based on a new taxonomy of uncertainty. We illustrate the relevance of this taxonomy with two concrete examples: the classical harmonic oscillator with some new twists that make physics look more like economics, and a quantitative equity market-neutral strategy. We conclude by offering a new interpretation of tail events, proposing an "uncertainty checklist" with which our taxonomy can be implemented, and considering the role that quants played in the current financial crisis.Comment: v3 adds 2 reference

    The Ethics of Corporate Governance

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    How should corporate directors determine what is the right decision? For at least the past 30 years the debate has raged as to whether shareholder value should take precedence over corporate social responsibility when crucial decisions arise. Directors face pressure, not least from ethical investors, to do the good thing when they seek to make the right choice. Corporate governance theory has tended to look to agency theory and the need of boards to curb excessive executive power to guide directors' decisions. While useful for those purposes, agency theory provides only limited guidance. Supplementing it with the alternatives - stakeholder theory and stewardship theory - tends to put directors in conflict with their legal obligations to work in the interests of shareholders. This paper seeks to reframe the discussion about corporate governance in terms of the ethical debate between consequential, teleological approaches to ethics and idealist, deontological ones, suggesting that directors are - for good reason - more inclined toward utilitarian judgments like those underpinning shareholder value. But the problems with shareholder value have become so great that a different framework is needed: strategic value, with an emphasis on long-term value creation judged from a decidedly utilitarian standpoint

    Compensation for Commuting in Imperfect Urban Markets

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    We develop an urban equilibrium job search model with employed and unemployed individuals where residential mobility of the unemployed is restricted. We assume a standard mono-centric model (firms are located in one location), but allow for imperfect labour markets. In contrast to models with perfect labour markets, the model predicts that the employed are only partially compensated for commuting costs in the form of wages. As a result, rent gradients are less steep than predicted by standard urban theories that assume perfectly competitive labour markets. © 2007 the author(s). Journal compilation © 2007 RSAI

    Ultrafast carrier relaxation in GaN, In_(0.05)Ga_(0.95)N and an In_(0.05)Ga_(0.95)/In_(0.15)Ga_(0.85)N Multiple Quantum Well

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    Room temperature, wavelength non-degenerate ultrafast pump/probe measurements were performed on GaN and InGaN epilayers and an InGaN multiple quantum well structure. Carrier relaxation dynamics were investigated as a function of excitation wavelength and intensity. Spectrally-resolved sub-picosecond relaxation due to carrier redistribution and QW capture was found to depend sensitively on the wavelength of pump excitation. Moreover, for pump intensities above a threshold of 100 microJ/cm2, all samples demonstrated an additional emission feature arising from stimulated emission (SE). SE is evidenced as accelerated relaxation (< 10 ps) in the pump-probe data, fundamentally altering the re-distribution of carriers. Once SE and carrier redistribution is completed, a slower relaxation of up to 1 ns for GaN and InGaN epilayers, and 660 ps for the MQW sample, indicates carrier recombination through spontaneous emission.Comment: submitted to Phys. Rev.

    Fermi super-Tonks-Girardeau state for attractive Fermi gases in an optical lattice

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    We demonstrate that a kind of highly excited state of strongly attractive Hubbard model, named of Fermi super-Tonks-Girardeau state, can be realized in the spin-1/2 Fermi optical lattice system by a sudden switch of interaction from the strongly repulsive regime to the strongly attractive regime. In contrast to the ground state of the attractive Hubbard model, such a state is the lowest scattering state with no pairing between attractive fermions. With the aid of Bethe-ansatz method, we calculate energies of both the Fermi Tonks-Girardeau gas and the Fermi super-Tonks-Girardeau state of spin-1/2 ultracold fermions and show that both energies approach to the same limit as the strength of the interaction goes to infinity. By exactly solving the quench dynamics of the Hubbard model, we demonstrate that the Fermi super-Tonks-Girardeau state can be transferred from the initial repulsive ground state very efficiently. This allows the experimental study of properties of Fermi super-Tonks-Girardeau gas in optical lattices.Comment: 7 pages, 7 figure
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