947 resultados para business cycles, investment cycles, spectral tests


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We have directly measured properties of concentrated seawater brines produced through solar evaporation in salt works. They are sufficiently hygroscopic for use in desiccant cooling cycles which can cool air to 8.0–10.9 °C below ambient. This compares to only 3.8–8.7 °C with simple evaporative cooling. Desiccant cooling can extend the growing seasons of greenhouse crops thus providing an adaptive measure against climate change.

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We prove that in quadratic perturbations of generic Hamiltonian vector fields with two saddle points and one center there can appear at most two limit cycles. This bound is exact.

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Permanent deformation and fracture may develop simultaneously when an asphalt mixture is subjected to a compressive load. The objective of this research is to separate viscoplasticity and viscofracture from viscoelasticity so that the permanent deformation and fracture of the asphalt mixtures can be individually and accurately characterized without the influence of viscoelasticity. The undamaged properties of 16 asphalt mixtures that have two binder types, two air void contents, and two aging conditions are first obtained by conducting nondestructive creep tests and nondestructive dynamic modulus tests. Testing results are analyzed by using the linear viscoelastic theory in which the creep compliance and the relaxation modulus are modeled by the Prony model. The dynamic modulus and phase angle of the undamaged asphalt mixtures remained constant with the load cycles. The undamaged asphalt mixtures are then used to perform the destructive dynamic modulus tests in which the dynamic modulus and phase angle of the damaged asphalt mixtures vary with load cycles. This indicates plastic evolution and crack propagation. The growth of cracks is signaled principally by the increase of the phase angle, which occurs only in the tertiary stage. The measured total strain is successfully decomposed into elastic strain, viscoelastic strain, plastic strain, viscoplastic strain, and viscofracture strain by employing the pseudostrain concept and the extended elastic-viscoelastic correspondence principle. The separated viscoplastic strain uses a predictive model to characterize the permanent deformation. The separated viscofracture strain uses a fracture strain model to characterize the fracture of the asphalt mixtures in which the flow number is determined and a crack speed index is proposed. Comparisons of the 16 samples show that aged asphalt mixtures with a low air void content have a better performance, resisting permanent deformation and fracture. © 2012 American Society of Civil Engineers.

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Sustainable development requires combining economic viability with energy and environment conservation and ensuring social benefits. It is conceptualized that for designing a micro industry for sustainable rural industrialization, all these aspects should be integrated right up front. The concept includes; (a) utilization of local produce for value addition in a cluster of villages and enhancing income of the target population; (b) use of renewable energy and total utilization of energy generated by co and trigeneration (combining electric power production with heat utilization for heating and cooling); (c) conservation of water and complete recycling of effluents; (d) total utilization of all wastes for achieving closure towards a zero waste system. Enhanced economic viability and sustainability is achieved by integration of appropriate technologies into the industrial complex. To prove the concept, a model Micro Industrial Complex (MIC) has been set up in a semi arid desert region in Rajasthan, India at village Malunga in Jodhpur district. A biomass powered boiler and steam turbine system is used to generate 100-200 KVA of electric power and high energy steam for heating and cooling processes downstream. The unique feature of the equipment is a 100-150 kW back-pressure steam turbine, utilizing 3-4 tph (tonnes per hour) steam, developed by M/s IB Turbo. The biomass boiler raises steam at about 20 barg 3 tph, which is passed through a turbine to yield about 150 kW of electrical power. The steam let out at a back pressure of 1-3 barg has high exergy and this is passed on as thermal energy (about 2 MW), for use in various applications depending on the local produce and resources. The biomass fuel requirement for the boiler is 0.5-0.75 tph depending on its calorific value. In the current model, the electricity produced is used for running an oil expeller to extract castor oil and the castor cake is used as fuel in the boiler. The steam is used in a Multi Effect Distillation (MED) unit for drinking water production and in a Vapour Absorption Machine (VAM) for cooling, for banana ripening application. Additional steam is available for extraction of herbs such as mint and processing local vegetables. In this paper, we discuss the financial and economic viability of the system and show how the energy, water and materials are completely recycled and how the benefits are directed to the weaker sections of the community.

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Using the case of a low cost airline company’s website we analyze some special research questions of information technology valuation. The distinctive characteristics of this research are the ex post valuation perspective; the parallel and comparative use of accounting and business valuation approaches; and the integrated application of discounted cash flow and real option valuation. As the examined international company is a strategic user of e-technology and wants to manage and account intangible IT-assets explicitly, these specific valuation perspectives are gaining practical significance.

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Bródy András kutatásainak egyik központi témaköre a gazdasági mozgás vizsgálata volt. Írásunkban Bródy elméletét kívánjuk röviden áttekinteni és összefoglalni. A termelés sokszektoros leírása egyben árelméletét (értékelméletét, méréselméletét) is keretbe foglalja. Ebben a keretben a gazdasági mozgás összetett ingadozása technológiai alapon elemezhető. Bródy megközelítésében a gazdasági ciklust nem külső megrázkódások magyarázzák, hanem a termelési rendszer belső arányai és kapcsolatai. A termelési struktúrát az árak és a volumenek egyformán alakítják, ezek között nincsen kitüntetett vagy domináns tényező. Az árak és a volumenek a köztük lévő duális kapcsolatban alakulnak ki. A gazdaság mozgásegyenleteit technológiai mérlegösszefüggések, valamint a piaci csere útján a gazdaságban újraelosztásra (újratermelésre) kerülő termékek felhasználása és az eszközlekötés változása írja le. Az így meghatározott mozgásegyenletek a gazdaság természetes mozgását ciklusmozgás alakjában írják le. A technológia vagy az értékviszonyok megváltozása (sokkok) a gazdaság ciklikus mozgásának megváltozásában tükröződik. Bródy munkáiban technológiai megalapozást nyer a történelemből ismert számos jellegzetes gazdasági ciklus. / === / Economic motion and dynamics are at the heart of Andras Brody's creative output. This paper attempts a bird's-eye view of his theory of economic cycles. Brody's multi-sector modelling of production has provided a framework for price theory (the theory of value and measurement). His theory of economic motion with cyclical characteristics is technology driven. It argues that the complex web of economic cycles is determined by the proportions and interrelationships of the system of production, not by arbitrary external shocks. The structure's behaviour are driven by prices and proportions, with the duality of prices and proportions as a dominant feature. These are features in common with the Leontief models, which Brody extended to economic cycles. Brody saw economic cycles as natural motions of economic systems with accumulated assets (time lags) and market exchange of goods (demand and supply adjustment). Changes in technology or valuations (shocks) are reflected in changing patterns of motion. His model of the economy is a fine instrument that enabled him to show how the technological parameters of its system determine the frequency and other characteristics of various economic cycles identified in economic history.

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Understanding how decisions for international investments are made and how this affects the overall pattern of investments and firm’s performance is of particular importance both in strategy and international business research. This dissertation introduced first home-host country relatedness (HHCR) as the degree to which countries are efficiently combined within the investment portfolios of firms. It theorized and demonstrated that HHCR will vary with the motivation for investments along at least two key dimensions: the nature of foreign investments and the connectedness of potential host countries to the rest of the world. Drawing on cognitive psychology and decision-making research, it developed a theory of strategic decision making proposing that strategic solutions are chosen close to a convenient anchor. Building on research on memory imprinting, it also proposed that managers tend to rely on older knowledge representation. In the context of international investment decisions, managers use their home countries as an anchor and are more likely to choose as a site for foreign investments host countries that are ‘close’ to the home country. These decisions are also likely to rely more strongly on closeness to time invariant country factors of historic and geographic nature rather than time-variant institutions. Empirical tests using comprehensive investments data by all public multinational companies (MNC) worldwide, or over 15,000 MNCs with over half a million subsidiaries, support the claims. Finally, the dissertation introduced the concept of International Coherence (IC) defined as the degree to which an MNE’s network comprises countries that are related. It was hypothesized that maintaining a high level of coherence is important for firm performance and will enhance it. Also, the presence of international coherence mitigates some of the negative effects of unrelated product diversification. Empirical tests using data on foreign investments of over 20,000 public firms, while also developing a home-host country relatedness index for up to 24,300 home-host pairs, provided support for the theory advanced.

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© The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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Acknowledgements GIA is grateful for funding from the Carnegie Trust for the Universities of Scotland that enabled fieldwork for this project. RW was supported by the Israel Science Foundation (ISF grant No. 1245/11). SM was supported by the Israel Science Foundation (ISF grant No. 1436/14). We would like to thank Chris Talbot and Yohann Poprawski for careful and constructive reviews. The authors appreciate the help of Nicolas Waldmann in precisely locating the positons of dated unconformities.

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This thesis analyzes the Chow motives of 3 types of smooth projective varieties: the desingularized elliptic self fiber product, the Fano surface of lines on a cubic threefold and an ample hypersurface of an Abelian variety. For the desingularized elliptic self fiber product, we use an isotypic decomposition of the motive to deduce the Murre conjectures. We also prove a result about the intersection product. For the Fano surface of lines, we prove the finite-dimensionality of the Chow motive. Finally, we prove that an ample hypersurface on an Abelian variety possesses a Chow-Kunneth decomposition for which a motivic version of the Lefschetz hyperplane theorem holds.

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The influence of Antarctica and the Southern Ocean on Late Pliocene global climate reconstructions has remained ambiguous due to a lack of well-dated Antarctic-proximal, paleoenvironmental records. Here we present ice sheet, sea-surface temperature, and sea ice reconstructions from the ANDRILL AND-1B sediment core recovered from beneath the Ross Ice Shelf. We provide evidence for a major expansion of an ice sheet in the Ross Sea that began at ~3.3 Ma, followed by a coastal sea surface temperature cooling of ~2.5°C, a stepwise expansion of sea ice, and polynya-style deep mixing in the Ross Sea between 3.3 and 2.5 Ma. The intensification of Antarctic cooling resulted in strengthened westerly winds and invigorated ocean circulation. The associated northward migration of Southern Ocean fronts has been linked with reduced Atlantic Meridional Overturning Circulation by restricting surface water connectivity between the ocean basins, with implications for heat transport to the high latitudes of the North Atlantic. While our results do not exclude low-latitude mechanisms as drivers for Pliocene cooling, they indicate an additional role played by southern high-latitude cooling during development of the bipolar world.

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In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (d15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrate consumption and Antarctic climate across the last two glacial cycles, with d15Ndb (and thus the degree of nitrate consumption) increasing at each major Antarctic cooling event. Coupled with evidence from opal- and barium-based proxies for reduced export production during ice ages, the d15Ndb increases point to ice age reductions in the supply of deep ocean-sourced nitrate to the AZ surface. The two diatom assemblages and species abundance data indicate that the d15Ndb changes are not the result of changing species composition. The pennate and centric assemblage d15Ndb records indicate similar changes but with a significant decline in their difference during peak ice ages. A tentative seasonality-based interpretation of the centric-to-pennate d15Ndb difference suggests that late summer surface waters became nitrate free during the peak glacials.

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Objetivo: Avaliar o padrão pulsátil da secreção da testosterona em mulheres normais. Métodos: Oito mulheres saudáveis com ciclos ovulatórios foram selecionadas. Amostras sanguíneas foram coletadas a cada dez minutos durante seis horas, começando entre 7 e 8 h da manhã, após dez horas de jejum, nas três fases do ciclo menstrual: folicular média (Dia 7), folicular tardia (Dia 12) e lútea (Dia 21). Foram mensurados: testosterona, LH e, no basal, também SHBG. Resultados: A frequência dos pulsos de testosterona, média da amplitude do pulso, porcentagem do incremento da amplitude, duração e intervalos dos pulsos foram similares nas três fases (p > 0,05). A pulsatilidade do LH foi estatisticamente diferente entre as três fases (p < 0,001), caracterizando padrão característico do ciclo ovulatório normal. Conclusões: Esses dados aumentam o conhecimento sobre o padrão de secreção da testosterona no ciclo menstrual humano e representam uma contribuição para a investigação clínica, tanto no hiperandrogenismo como na síndrome de insuficiência androgênica __________________________________________________ ABSTRACT Objective: To evaluate the pattern of the pulsatile secretion of testosterone in normal menstrual cycle. Methods: Eight healthy women with ovulatory menstrual cycles were enrolled. Blood samples were collected at ten-minute intervals for six hours, starting between 7 and 8 am, after a ten-hour fasting, in three phases: mid-follicular (Day 7), late follicular (Day 12) and mid-luteal phase (Day 21). Samples were assayed for testosterone, LH and the baseline also for SHBG. Results: Testosterone pulse frequency, mean amplitude pulse, percentage of increment in pulse amplitude, mean duration of pulses and pulse interval were similar in the three phases. LH pulsatility was statistically different among the three phases (p < 0.001) representing normal ovulatory cycles. Conclusions: These data increase the knowledge about the testosterone secretion profile in the human menstrual cycle and can be used as a contribution to clinical investigation in both hyperandrogenism and androgen insufficiency syndrome