972 resultados para External environment
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The regulation of breathing.--The readjustments of regulation in acclimatisation and disease.--Regulation of the environment, internal and external.--Organic regulation as the essence of life. Inadequacy of mechanistic and vitalistic conceptions.
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In this article we present a study of the effects of external and internal mass transfer limitation of oxygen in a nitrifying system. The oxygen uptake rates (OUR) were measured on both a macro-scale with a respirometric reactor using off-gas analysis (Titrimetric and Off-Gas Analysis (TOGA) sensor) and on a micro-scale with microsensors. These two methods provide independent, accurate measurements of the reaction rates and concentration profiles around and in the granules. The TOGA sensor and micro-sensor measurements showed a significant external mass transfer effect at low dissolved oxygen (DO) concentrations in the bulk liquid while it was insignificant at higher DO concentrations. The oxygen distribution with anaerobic or anoxic conditions in the center clearly shows major mass transfer limitation in the aggregate interior. The large drop in DO concentration of 22 - 80% between the bulk liquid and aggregate surface demonstrates that the external mass transfer resistance is also highly important. The maximum OUR even for floccular biomass was only attained at much higher DO concentrations ( approximate to 8 mg/L) than typically used in such systems. For granules, the DO required for maximal activity was estimated to be > 20mg/L, clearly indicating the effects of the major external and internal mass transfer limitations on the overall biomass activity. Smaller aggregates had a larger volumetric OUR indicating that the granules may have a lower activity in the interior part of the aggregate. (C) 2004 Wiley Periodicals, Inc.
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The abundance and community composition of the endofauna in 2 species of sponge, Haliclona sp. 1 and Haliclona sp. 2 (phylum Porifera: order Haplosclerida), were examined at different sites on the slope at Heron Island Reef, in the southern Great Barrier Reef, on 2 separate occasions. Both species of Haliclona Occupy Similar habitats on the reef slope and are often found living adjacent to each other, but the major groups of secondary metabolites and the gross external morphology in the 2 species of sponge are different. The 2 species of sponge supported significantly different endofaunal communities, with Haliclona sp. 2 Supporting 3 to 4 times more individuals than Haliclona sp. 1. Fewer demersal zooplankton (copepods), nematodes and some peracarid crustaceans were found in Haliclona sp. I compared with Haliclona sp. 2. There were also differences in the numbers of spionid, nereidid and syllid. polychaetes living in the 2 species of sponge. The only taxon that was more abundant in Haliclona sp. 1 than Haliclona sp. 2 was the spionid Polydorella prolifera, and this difference was only evident on 1. of the 2 occasions. The amount of free space (pores, channels, cavities) for a given weight of sponge was only 19% greater in Haliclona sp. 2 than in Haliclona sp. 1, suggesting other factors, such as the differences in the allelochemicals, may have a role in determining the numbers and types of animals living in these 2 species of sponge.
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The developments of models in Earth Sciences, e.g. for earthquake prediction and for the simulation of mantel convection, are fare from being finalized. Therefore there is a need for a modelling environment that allows scientist to implement and test new models in an easy but flexible way. After been verified, the models should be easy to apply within its scope, typically by setting input parameters through a GUI or web services. It should be possible to link certain parameters to external data sources, such as databases and other simulation codes. Moreover, as typically large-scale meshes have to be used to achieve appropriate resolutions, the computational efficiency of the underlying numerical methods is important. Conceptional this leads to a software system with three major layers: the application layer, the mathematical layer, and the numerical algorithm layer. The latter is implemented as a C/C++ library to solve a basic, computational intensive linear problem, such as a linear partial differential equation. The mathematical layer allows the model developer to define his model and to implement high level solution algorithms (e.g. Newton-Raphson scheme, Crank-Nicholson scheme) or choose these algorithms form an algorithm library. The kernels of the model are generic, typically linear, solvers provided through the numerical algorithm layer. Finally, to provide an easy-to-use application environment, a web interface is (semi-automatically) built to edit the XML input file for the modelling code. In the talk, we will discuss the advantages and disadvantages of this concept in more details. We will also present the modelling environment escript which is a prototype implementation toward such a software system in Python (see www.python.org). Key components of escript are the Data class and the PDE class. Objects of the Data class allow generating, holding, accessing, and manipulating data, in such a way that the actual, in the particular context best, representation is transparent to the user. They are also the key to establish connections with external data sources. PDE class objects are describing (linear) partial differential equation objects to be solved by a numerical library. The current implementation of escript has been linked to the finite element code Finley to solve general linear partial differential equations. We will give a few simple examples which will illustrate the usage escript. Moreover, we show the usage of escript together with Finley for the modelling of interacting fault systems and for the simulation of mantel convection.
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Purpose – The purpose of this paper is to explore the role and relevance of external standards in demonstrating the value and impact of academic library services to their stakeholders. Design/methodology/approach – Two UK standards, Charter Mark and Customer Service Excellence, are evaluated via an exploratory case study, employing multiple data collection techniques. Methods and results of phases 1-2 of a three phase research project are outlined. Findings – Despite some limitations, standards may assist the manager in demonstrating the value, impact and quality of academic libraries in a recessional environment. Active engagement and partnership with customers is imperative if academic libraries are to be viewed as vital to their parent organisations and thus survive. Originality/value – This paper provides a systematic evaluation of the role of external accreditation standards in measuring academic library service value and impact.
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The research concerns the development and application of an analytical computer program, SAFE-ROC, that models material behaviour and structural behaviour of a slender reinforced concrete column that is part of an overall structure and is subjected to elevated temperatures as a result of exposure to fire. The analysis approach used in SAFE-RCC is non-linear. Computer calculations are used that take account of restraint and continuity, and the interaction of the column with the surrounding structure during the fire. Within a given time step an iterative approach is used to find a deformed shape for the column which results in equilibrium between the forces associated with the external loads and internal stresses and degradation. Non-linear geometric effects are taken into account by updating the geometry of the structure during deformation. The structural response program SAFE-ROC includes a total strain model which takes account of the compatibility of strain due to temperature and loading. The total strain model represents a constitutive law that governs the material behaviour for concrete and steel. The material behaviour models employed for concrete and steel take account of the dimensional changes caused by the temperature differentials and changes in the material mechanical properties with changes in temperature. Non-linear stress-strain laws are used that take account of loading to a strain greater than that corresponding to the peak stress of the concrete stress-strain relation, and model the inelastic deformation associated with unloading of the steel stress-strain relation. The cross section temperatures caused by the fire environment are obtained by a preceding non-linear thermal analysis, a computer program FIRES-T.
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This article examines environmental governance in Kosovo, with a particular focus on the energy sector. The article considers the degree to which the emerging model of environmental governance is characterised by hierarchical and non-hierarchical modes of coordination. We examine the roles of a number of domestic institutions and actors – ministries, agencies, and regulatory bodies– and the influence of external actors, including the EU, the US, and Serbia. The EU is building Kosovo’s own hierarchical governance capacity by strengthening domestic institutions, whilst the US focuses primarily on market liberalization, whilst simultaneously supporting EU efforts. Moreover, environmental policy change is not wholly or predominantly driven by domestic actors, which can partly be attributed to Kosovo’s limited domestic sovereignty. We conclude that the emerging model of environmental governance in Kosovo is characterized by a weak hierarchy, partly as a result of external actor involvement, which disincentivises the government from responding to domestic non-state actor pressure.
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A tanulmány nem az aktuális hitelpiaci válság enyhítésének kérdésével foglalkozik, hanem az amerikai gazdaság elmúlt négy évtizedének általános és az utolsó tíz évének konkrét beruházási-megtakarítási és növekedési tendenciáit igyekszik feltárni. Azt vizsgálja, hogy milyen mélyebb, belföldi eredetű szerkezeti okai vannak a nemzetközivé dagadt jelzáloghitel-válságnak. A cikk a nyitott gazdaság külső finanszírozással összefüggő mérlegazonosságainak alapján arra a következtetésre jut, hogy az ingatlanpiaci visszaesés és a kibocsátás zsugorodása az Egyesült Államok gazdaságában már több mint másfél évtizede kialakult kedvezőtlen, de még tovább romló belföldi megtakarítási folyamatok következménye. A jelzálogpiac krízise és a lakásépítés drámai visszaesése a túlfogyasztásra és túlhitelezésre ösztönző pénzügyi környezet eredménye. A lakáspiaci és a hitelezési ciklusok pénzügyi innovációkkal történő megnyújtása inkább növelte, mint csökkentette a kibocsátásingadozás érzékenységét. A legfőbb hitelezők Kína, Japán, Németország inkább dolláralapú amerikai vállalati felvásárlásokkal ellensúlyozták a dollárgyengülésből elszenvedett veszteségeiket. 1997-2007 között az Amerikából külföldön befektetett dolláraktívák - javarészt a valuta leértékelődése nyomán - jelentős hozamemelkedést élveztek, és számottevően tompították a belföldön képződött jövedelmek csökkenését. A dollárleértékelődés az eszköz- (és nemcsak az áruexport) oldalon is előnyöket hozott számos nagyvállalatnak. / === / Rather than dealing with the immediate policy steps to dampen the crisis, this paper attempts to reveal the worsening savings/consumption pattern of the US economy over the last ten years. Based on the closed logic of open-economy GDP-accounting, it argues that the current crisis is deeply rooted in shrinking public and private savings trends discernible as early as 1997. The current mortgage-market crisis and deep fall in new residential housing are products of a distorted financial environment that encourages over-borrowing and over-consumption. Expansion of the credit cycle through successive financial innovations has increased, not decreased output volatility. But the main foreign lenders to the US—Japan, China and Germany—have managed to offset their losses on US securities by buying into US companies. Large US firms have also benefited from rapid dollar depreciation as USD-denominated yields on their foreign assets experienced strong run-ups. The weak dollar has also helped American firms with large assets on foreign markets. So there were strong benefits for the US, not just on the goods-export side, but on the asset side, an aspect rarely emphasized.
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A szerzők tanulmányának célja, hogy bemutassa, milyen célokra alkalmazzák az internetet a hazai vállalatok, milyen várakozásaik vannak az e-kereskedelem versenyben betöltött szerepével kapcsolatban, és hogyan észlelik annak előnyeit. Vizsgálják azt is, hogy az elmúlt öt évben milyen változások tapasztalhatók a vállalatok gyakorlatában e téren. Elemzik továbbá, hogy a piacorientáció és a vállalat külső marketingkörnyezete hogyan befolyásolja az e-kereskedelem megítélését és alkalmazását. Elemzésük a "Versenyben a világgal" kutatási program 2009-ben készült felmérésének eredményeire támaszkodik, amelyben 300 vállalat szakembereit kérdezték meg. Kutatásukban megerősítést nyert, hogy Magyarországon az elektronikus kereskedelem jelentősége nő. A vállalatoknak kedvezőek az elektronikus kereskedelem jövőjével kapcsolatos várakozásaik, és úgy vélik, hogy ez versenyelőny forrása lehet. A vállalat piacorientációja erőteljesen befolyásolja azt, hogy egy vállalat milyen mértékben alkalmazza az internetet, és hogyan viszonyul az elektronikus kereskedelemhez / === / The objective of the authors’ research is to show how internet is used among Hungarian companies, to analyse their expectations with regard of the role e-commerce plays in competition, and the benefits resulting from e-commerce. They also focus on the changes that have taken place the past five years in the practice of Hungarian companies. The authors investigate how market orientation and the external marketing environment of firms influence evaluations of e-commerce and its implementation. Their analysis is based on the results of the research program „Competing with the world” , which includes the answers of 300 companies. Their research results confirm that the importance of e-commerce is growing in Hungary and overall Hungarian firms have positive expectations with regard of the future of e-commerce and consider it a source of competitive advantage. Market orientation of the firm strongly influences the extent of internet applications and attitudes toward ecommerce.
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This dissertation explores the complex interactions between organizational structure and the environment. In Chapter 1, I investigate the effect of financial development on the formation of European corporate groups. Since cross-country regressions are hard to interpret in a causal sense, we exploit exogenous industry measures to investigate a specific channel through which financial development may affect group affiliation: internal capital markets. Using a comprehensive firm-level dataset on European corporate groups in 15 countries, we find that countries
with less developed financial markets have a higher percentage of group affiliates in more capital intensive industries. This relationship is more pronounced for young and small firms and for affiliates of large and diversified groups. Our findings are consistent with the view that internal capital markets may, under some conditions, be more efficient than prevailing external markets, and that this may drive group affiliation even in developed economies. In Chapter 2, I bridge current streams of innovation research to explore the interplay between R&D, external knowledge, and organizational structure–three elements of a firm’s innovation strategy which we argue should logically be studied together. Using within-firm patent assignment patterns,
we develop a novel measure of structure for a large sample of American firms. We find that centralized firms invest more in research and patent more per R&D dollar than decentralized firms. Both types access technology via mergers and acquisitions, but their acquisitions differ in terms of frequency, size, and i\ntegration. Consistent with our framework, their sources of value creation differ: while centralized firms derive more value from internal R&D, decentralized firms rely more on external knowledge. We discuss how these findings should stimulate more integrative work on theories of innovation. In Chapter 3, I use novel data on 1,265 newly-public firms to show that innovative firms exposed to environments with lower M&A activity just after their initial public offering (IPO) adapt by engaging in fewer technological acquisitions and
more internal research. However, this adaptive response becomes inertial shortly after IPO and persists well into maturity. This study advances our understanding of how the environment shapes heterogeneity and capabilities through its impact on firm structure. I discuss how my results can help bridge inertial versus adaptive perspectives in the study of organizations, by
documenting an instance when the two interact.
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The Cutri Formation’s, type location, exposed in the NW of Mallorca, Spain has previously been described by Álvaro et al., (1989) and further interpreted by Abbots (1989) unpublished PhD thesis as a base-of-slope carbonate apron. Incorporating new field and laboratory analysis this paper enhances this interpretation. From this analysis, it can be shown without reasonable doubt that the Cutri Formation was deposited in a carbonate base-of-slope environment on the palaeowindward side of a Mid-Jurassic Tethyan platform. Key evidence such as laterally extensive exposures, abundant deposits of calciturbidtes and debris flows amongst hemipelagic deposits strongly support this interpretation.
Evaporative Moisture Loss from Heterogeneous Stone: Material- Environment Interactions During Drying
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The complexities of evaporation from structurally and mineralogically heterogeneous sandstone (Locharbriggs Sandstone) are investigated through a laboratory-based experiment in which a variety of environmental conditions are simulated. Data reported demonstrate the significance of material-environment interactions on the spatial and temporal variability of evaporative dynamics. Evaporation from porous stone is determined by the interplay between environmental, material and solution properties, which govern the rate and mode by which water is transmitted to, and subsequently removed from, an evaporating surface. Initially evaporation is marked by high rates of moisture loss controlled by external atmospheric conditions; then, when a critical level of surface moisture content is reached, hydraulic continuity between the stone surface and subsurface is disrupted and the drying front recedes
beneath the surface, evaporation rates decrease and are controlled by the ability of the material to transport water vapour to the surface. Pore size distribution and connectivity, as well as other material properties, control the timing of each stage of evaporation and the nature of the transition.
These experimental data highlight the complexity of evaporation, demonstrating that different regions of the same stone can exhibit varying moisture dynamics during drying and that the rate and nature of evaporative loss differs under different environmental conditions. The results identify the importance of material-environment interactions during drying and that stone micro-environmental conditions cannot be inferred from ambient data alone.
These data have significance for understanding the spatial distribution of stone surface weathering-related morphologies in both the natural and built environments where mineralogical and/or structural heterogeneity creates differences in moisture flux and hence variable drying rates. Such differences may provide a clearer explanation for the initiation and subsequent development of complex weathering responses where areas of significant deterioration can be found alongside areas that exhibit little or no evidence surface breakdown.
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NOGUEIRA, Marcelo B. ; MEDEIROS, Adelardo A. D. ; ALSINA, Pablo J. Pose Estimation of a Humanoid Robot Using Images from an Mobile Extern Camera. In: IFAC WORKSHOP ON MULTIVEHICLE SYSTEMS, 2006, Salvador, BA. Anais... Salvador: MVS 2006, 2006.
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Within the last few decades of operations and supply chain management, the field has seen the rise of so called best practices, methods that will help supply chains obtain their business goals and gain a competitive edge. These methods were thought to be universal. This however is not always the case, as the surrounding business environment could have a significant impact on what will be effective in gaining competitive edge. Contingency theory states that the success of a supply chain is determined by both internal capabilities, as well as external context aligning. This creates a strategic fit, which is a major determinant of success. In order for supply chains to reach this strategic fit, they must adapt. As China has seen rapid growth and over the last few decades become one of the major economies of the world, Western companies have tried to establish themselves there, only to find that the Chinese market is extremely difficult to operate in. The aim of this thesis was to investigate from contingency theory perspective, what are the institutional factors that affect supply chain management of Finnish companies operating in China, and how do Finnish companies adapt their supply chains to better fit the Chinese institutional environment. A theoretical model was created for this thesis, in which supply chains possess resources, which can be combined in a meaningful manner to create capabilities. Both resources and capabilities are affected by the surrounding institutional environment, which forces supply chains to adapt in order to find a better strategic fit. A total of six Finnish managers from three large and three small companies operating in China were interviewed. The results indicated that the Chinese business environment is significantly different, than that of Finland or Western countries in general. Three institutional factors were identified: Confucian though, fast-paced business environment, and managing labor force. These three institutional factors made the relationship and delivery capabilities particularly important, as well as human resources, reputation, physical resources and technological resources. In conclusion, it was discovered that the Chinese institutional environment is heavily affected by Confucian thought, as well as the rapid market growth. These are the two most important institutional factors that shape the Chinese market. If supply chains wish to be successful in China, adaptation regarding these two institutional factors should yield good results.
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NOGUEIRA, Marcelo B. ; MEDEIROS, Adelardo A. D. ; ALSINA, Pablo J. Pose Estimation of a Humanoid Robot Using Images from an Mobile Extern Camera. In: IFAC WORKSHOP ON MULTIVEHICLE SYSTEMS, 2006, Salvador, BA. Anais... Salvador: MVS 2006, 2006.