903 resultados para Cash and cash equivalents
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Monte Carlo-Simulationen zum kritischen Verhalten dünnerIsing-Filme Dünne Ising-Filme können als vereinfachtes Modell zurBeschreibung von binären Mischungen oder von Flüssigkeitenin schlitzartigen Kapillaren dienen. Infolge dereingeschränkten Geometrie unterscheidet sich das kritischeVerhalten dieser Systeme signifikant von dem einesBulk-Systems, es kommt zu einem Crossover von zwei- zudreidimensionalem kritischen Verhalten. Zusätzlichverschiebt sich der Phasenübergang in den ungesättigtenBereich, ein Effekt, der als 'capillary condensation'bezeichnet wird. In der vorliegenden Arbeit wurden die kritischenEigenschaften von Ising-Filmen im Rahmen einer MonteCarlo-Simulation untersucht. Zur Verbesserung der Effizienzwurde ein Cluster-Algorithmus verwendet, der um einenGhost-Spin-Term zur Behandlung der Magnetfelder erweitertwar. Bei der Datenanalyse kamen moderneMulti-Histogramm-Techniken zur Anwendung. Für alle untersuchten Schichtdicken konnten kritischeTemperatur und Magnetfeld sehr präzise bestimmt werden. DieSkalenhypothese von Fisher und Nakanishi, die dieVerschiebung des kritischen Punktes gegenüber seinesBulk-Wertes beschreibt, wurde sowohl für Systeme mit freienOberflächen als auch für Systeme mit schwachemOberflächenfeld bestätigt. Der Wert des Gap-Exponenten derOberfläche wurde mit $Delta_1$=0.459(13) in Übereinstimmungmit den Literaturwerten abgeschätzt. Die Observablen Magnetisierung und magnetischeSuszeptibilität sowie deren auf die Oberfläche bezogenenEntsprechungen zeigen kein reines zweidimensionaleskritisches Verhalten. Zu ihrer Beschreibung in der Nähe deskritischen Punktes wurden effektive Exponenten für dieeinzelnen Schichtdicken bestimmt.
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Die Reaktion von Kupfertris(trimathylsilyl)silan (= Hypersilylkupfer, CuHyp) mit Iodoorganylverbindungen sollte analog zum Ullmann-Protokoll zum Halogen-Nukleophil-Austausch führen. Tatsächlich beobachteten wir zumeist die Bildung von Cuprio-Organylen, isolierbar in Form von mehrkernigen Neutralkomplexen aus dem Produkt und weiteren Äquivalenten von Hypersilylkupfer. Nach Zugabe von (weichen) Basen wie Trimethylphosphan kam es zur Auflösung dieser Komplexe und zur Bildung der erwarteten Silylorganyle. Von der systematischen Variation der eingesetzten Arene, Alkene und Alkine sowie ihrer Liganden versprachen wir uns tiefere Einsicht in die mechanistischen Zusammenhänge. Neben dem üblichen Halogen-Kupfer-Autausch konnten wir bei orthosubstituierten, bzw. zusätzlich tetramethylsubstituierten Diiodarenen einen einfachen Iod-Siyl-Autausch beobachten (vermutlich über Arinzwischenstufen), für Alkinedukte sogar eine doppelte Silylierung. Tatsächlich zeigen quantenchemische Berechnungen für CuHyp-Iodoorganyl-Systeme eine klare Präferenz von ullmannartigen Verläufen; andererseits führte Basenzugabe erst nachträglich zur Bildung von Ullmann-Produkten über die Auflösung der primären Komplexe. Innerhalb der üblicherweise gebildeten mehrkernigen Komplexe kommen Bindungen durch die Wechselwirkung unbesetzter σ*-Molekülorbitalee am Kupferzentrum von CuHyp und elektronenreichen bindenden Orbitalen in den Kupferorganyleinheiten zustande. Freie Elektronenpaare am Phosphor bei PMe3 könnten analog die Auflösung der Neutralkomplexe und die Bildung von vierkernigen Kupfer(III)-Intermediaten zwischen den Kupferorganyleinheiten und Iodsilan in der Lösung bewirken, die aufgrund ihrer strukturellen und energetischen Besonderheiten zu den erwarteten Ullmann-Produkten weiterreagieren würden. Die beobachteten Primärreaktionen verliefen dann offensichtlich über vergleichbare, aber unterschiedlich strukturierte Intermediate, vermutlich aufgrund der Tatsache, dass das eingesetzte CuHyp als Trimer vorliegt. Diese Annahme wird durch die direkte Silylierung von Iodalkinen gestützt, deren Dreifachbindungen möglicherweise als interne Base die trimeren in monomere CuHyp-Einheiten überführen. In eine ähnliche Richtung wäre die jüngst berichtete direkte Silylierung von Allylen bei Anwesenheit von elektronenreichen CN-Gruppen zu deuten.
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Polymers with mid-chain alkoxyamine functionality were synthesized by activating monohalogenated polymers in the presence of nitroso or nitrone radical traps. The resulting polymers were either polystyrene (PSt) homopolymers with a mid-chain alkoxyamine or PSt-poly(methyl acrylate) (PMA) diblock copolymers with an alkoxyamine unit at the junction between the segments. Monohalogenated polymers where synthesized by atom transfer radical polymerization (ATRP) and were then reacted to form polymer radicals in the presence of a radical trap, nitrone or nitroso. When only polystyrene radicals were reacted with the radical trap a dimer was formed with an alkoxyamine functionality in the center of the polymer chain. This functionality allowed the polymer chain to be cleaved in order to visualize the extent of the alkoxyamine functionality incorporation into the polymer chains. It was found that near quantitative alkoxyamine mid-chain functionality could be achieved by activating the PStBr in the presence of 10 equivalents of nitrone, 5 equivalents of copper bromide, and 2 equivalents of copper metal. Further reducing the amount of copper metal led to incomplete coupling, while increasing the equivalents beyond 2 generated polymer dimers with less than quantitative mid-chain functionality. Monochlorinated polystyrene (PStCl) precursors gave much poorer coupling results compared to reactions with PStBr, which is consistent with the stronger C-Cl bond resisting activation and the formation of the polystyryl radicals. When poly (methyl acrylate) (PMABr) is reacted with PStBr in the presence of a nitroso group at reduced temperatures (30 oC) block copolymers were selectively formed with an alkoxyamine functionality in the center. This was done by first activating the PSt-Br to form a polymer radical that would react with the radical trap to form a persistent radical on the oxygen. The PMA-Br, once activated, reacted with the radical on the oxygen to form the block copolymer. To test the amount of functionality incorporated, a coupling reaction was performed with no nitroso present, and found that no reaction occurred. This showed that the radical trap is essential for the coupling to occur, and cleavage of the diblock indicated that the alkoxyamine functionality was indeed incorporated into the diblock.
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Quaternary sedimentation within the Japan Sea was controlled by the configuration of peripheral sills, seasonal and long-term climatic variability, and the resultant fluctuations in sea level (Tamaki, 1988). Prior to drilling in the area, piston cores recovered from its basins contained Pleistocene sediments having distinctive color and fabric variation. Sedimentological and geochemical studies conducted on those facies indicated that the variability in fabric was the result of fluctuating marine and/or terrigenous influx to the deep-water basins of the Japan Sea (see, for example, Chough, 1984; Matoba, 1984). The sequences recovered during Leg 127 at Sites 794, 795, and 797 contain long, virtually undisturbed sequences (92.3, 123, and 119.9 mbsf [Hole 797B], respectively) of upper Miocene, upper Pliocene, and Pleistocene/Holocene sediments. The majority of these sequences consists of dark-colored (dark brown, green, and black) silty-clays, many of which are enriched in biogenic components (majority silicious, some carbonate) and/or organic matter, some containing pyrite and/or ash. These facies alternate with light-colored silty-clays, some containing ash and some showing signs of bioturbation (for example, Tamaki, Pisciotto, Allan, et al., 1990, p. 425-433). The dark-to-light sequences are present throughout the section, although they are especially dominant throughout the Pleistocene (for a more detailed lithology of Quaternary sequences recovered at Sites 794, 795, and 797, see Follmi et al. 1992 and Tada et al., 1992). This data report provides trace metal information on Pliocene-Pleistocene-Holocene samples at Sites 794,795, and 797. These data can be used (1) to provide information related to the depositional environments of the Japan Sea during the Quaternary period, (2) to permit comparisons between the dark organic-rich sediments recovered from this semi-enclosed basin and those reported for other silled basins (for example, the Mediterranean and Black seas), and (3) to permit comparisons between these sediments and contemporary equivalents found, for instance, beneath areas of high biogenic productivity. By providing such data, one should be able (1) to determine more precisely the processes governing the deposition of sediments with various levels of organic matter within enclosed basins, (2) to compare individual basin-wide processes, (3) to look for and compare the signatures present as a result of climatic fluctuation, and (4) to attempt to identify the presence and/or absence of cyclicity within such sequences.
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The Kimmeridge Clay Formation (KCF) and its equivalents worldwide represent one of the most prolonged periods of organic carbon accumulation of the Mesozoic. In this study, we use the molybdenum (Mo) stable isotope system in conjunction with a range of trace metal paleoredox proxies to assess how seawater redox varied both locally and globally during the deposition of the KCF. Facies with lower organic carbon contents (TOC 1-7 wt %) were deposited under mildly reducing (suboxic) conditions, while organic-rich facies (TOC >7 wt %) accumulated under more strongly reducing (anoxic or euxinic) local conditions. Trace metal abundances are closely linked to TOC content, suggesting that the intensity of reducing conditions varied repeatedly during the deposition of the KCF and may have been related to orbitally controlled climate changes. Long-term variations in d98/95Mo are associated with the formation of organic-rich intervals and are related to third-order fluctuations in relative sea level. Differences in the mean d98/95Mo composition of the organic-rich intervals suggest that the global distribution of reducing conditions was more extensive during the deposition of the Pectinatites wheatleyensis and lower Pectinatites hudlestoni zones than during the deposition of the upper Pectinatites hudlestoni and Pectinatites pectinatus zones. The global extent of reducing conditions during the Kimmerigidan was greater than today but was less widespread than during the Toarcian (Early Jurassic) oceanic anoxic event. This study also demonstrates that the Mo isotope system in Jurassic seawater responded to changes in redox conditions in a manner consistent with its behavior in present-day sedimentary environments.
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Esta investigación se ocupa de comprobar la viabilidad de un término, un concepto que se detecta como posible instrumento para nombrar algunas operaciones en arquitectura. Ese concepto es Lo Neutro. Frente al sistema de dualidades con el que enunciamos lo real, lo Neutro se sitúa, no tanto en el punto medio, como en el punto opuesto a ambos términos. No es la conjunción de contrarios, sino aquello que desvía la propia pregunta que obliga a elegir. Próximo a los conceptos de indefinición, indiferencia e inacción, lo Neutro se revela como un mecanismo fundamental de disolución. Reconociendo en la lengua varios sentidos para el término, con cada capítulo, la tesis va construyendo una definición ampliada de lo Neutro hasta configurar un conjunto de significados aplicables a la arquitectura. El primero de ellos es el que se deriva del concepto de indiferencia funcional. Tras un análisis del contexto teórico sobre el que se asienta la dialéctica bi-direccional forma-función, su consolidación en los primeros años del siglo XX y también su puesta en crisis mediante la introducción de nociones multi-relacionales como ‘entorno’ y ‘sistema’, la investigación propone tres modelos de estudio: la Planta Tipo, la Planta Única y la Planta de Equivalencias. En cada uno de estos casos, aunque el tema fundamental es la neutralidad programática, se reconoce también la presencia de los mecanismos geométricos y operaciones conceptuales que lo Neutro utiliza para generar respectivamente condiciones de ‘soporte’, de ‘marco’ o de ‘campo’. Estas tres condiciones espaciales apuntan a un entendimiento de lo Neutro que asocia su fórmula de doble negación (ni lo uno, ni lo otro) con el estado más incipiente de la materia, aquel en el que todavía no es pero que contiene ya todos los elementos de posibilidad de ser: lo Neutro como potencia. Aquello que la lógica nos impide afirmar, que una cosa es y no-es al mismo tiempo, nos lo concede la categoría aristotélica de la potencia. Por ello, en la última parte de la tesis se desarrollan de forma más autónoma aquellos temas vinculados con estos tres tipos de espacio que se basan en la renuncia, abordando la cuestión de la potencialidad desde la negación. Partiendo de dos condiciones superficiales básicas, la del muro vertical y la del suelo horizontal, se analizan algunos discursos basados en una restricción radical a estos dos elementos. Así, el muro ciego encuentra su precedente artístico en el lienzo en blanco y la tabula rasa se pone en relación con el concepto de ‘terrain vague’. Por último, la posibilidad de toda potencia de no actualizarse lleva a explorar el no-hacer como renuncia voluntaria y su capacidad de transformarse en acto de resistencia. ABSTRACT The concern of this research is to test the feasibility of a term, a concept that has been detected as a potential tool to name some architectural operations. That concept is the Neutral. In front of the dualities system with which we enounce the real, the Neutral places itself, not so much in the midpoint as in the opposite point of both terms. It is not the conjunction of the contraries, but that which deflects the question itself that compels us to make a choice. Recognizing the multiple interpretations of the term in the common language, with each chapter, the thesis builds an expanded definition of the Neutral to configure a set of meanings applicable to architecture. The first of them is the one that derives from the concept of functional indifference. After an analysis of the theoretical context in which the two-way dialectic between form and function lies, its consolidation in the early twentieth century and its call into crisis by the introduction of multi-relational concepts such as 'environment' and 'system', the research suggests three study models: the Typical Plan, the Single Plan and the Equivalents Plan. In each of these cases, although the fundamental issue is programmatic neutrality, it also recognizes the presence of geometric mechanisms and conceptual operations that the Neutral uses to generate respectively 'support', 'frame' or 'field' conditions. These three spatial conditions point to an understanding of the Neutral which associates its double negation formula (neither one nor the other) with the most incipient state of matter, that in which it not yet is, but already contains every element of the possibility of being: the neutral as potentiality. That which logic does not allow us to affirm, that one thing is and is-not at the same time, it is granted by the Aristotelian category of potentiality. Therefore, in the last part of the thesis, the topics relating these three types of space which are based on renouncement are more autonomously developed, addressing the issue of potentiality from the standpoint of denial. Starting from two basic surface conditions, the vertical wall and the horizontal floor, some speeches based on a radical restriction on these two elements are analyzed. Thus, the blind wall finds its artistic precedent in the blank canvas and the tabula rasa attitude gets in relation to the concept of ‘terrain vague’. Finally, the possibility of any potency of not being updated leads to explore the not-doing as voluntary resignation and its ability to transform itself into an act of resistance.
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Esta investigación se ocupa de comprobar la viabilidad de un término, un concepto que se detecta como posible instrumento para nombrar algunas operaciones en arquitectura. Ese concepto es Lo Neutro. Frente al sistema de dualidades con el que enunciamos lo real, lo Neutro se sitúa, no tanto en el punto medio, como en el punto opuesto a ambos términos. No es la conjunción de contrarios, sino aquello que desvía la propia pregunta que obliga a elegir. Próximo a los conceptos de indefinición, indiferencia e inacción, lo Neutro se revela como un mecanismo fundamental de disolución. Reconociendo en la lengua varios sentidos para el término, con cada capítulo, la tesis va construyendo una definición ampliada de lo Neutro hasta configurar un conjunto de significados aplicables a la arquitectura. El primero de ellos es el que se deriva del concepto de indiferencia funcional. Tras un análisis del contexto teórico sobre el que se asienta la dialéctica bi-direccional forma-función, su consolidación en los primeros años del siglo XX y también su puesta en crisis mediante la introducción de nociones multi-relacionales como ‘entorno’ y ‘sistema’, la investigación propone tres modelos de estudio: la Planta Tipo, la Planta Única y la Planta de Equivalencias. En cada uno de estos casos, aunque el tema fundamental es la neutralidad programática, se reconoce también la presencia de los mecanismos geométricos y operaciones conceptuales que lo Neutro utiliza para generar respectivamente condiciones de ‘soporte’, de ‘marco’ o de ‘campo’. Estas tres condiciones espaciales apuntan a un entendimiento de lo Neutro que asocia su fórmula de doble negación (ni lo uno, ni lo otro) con el estado más incipiente de la materia, aquel en el que todavía no es pero que contiene ya todos los elementos de posibilidad de ser: lo Neutro como potencia. Aquello que la lógica nos impide afirmar, que una cosa es y no-es al mismo tiempo, nos lo concede la categoría aristotélica de la potencia. Por ello, en la última parte de la tesis se desarrollan de forma más autónoma aquellos temas vinculados con estos tres tipos de espacio que se basan en la renuncia, abordando la cuestión de la potencialidad desde la negación. Partiendo de dos condiciones superficiales básicas, la del muro vertical y la del suelo horizontal, se analizan algunos discursos basados en una restricción radical a estos dos elementos. Así, el muro ciego encuentra su precedente artístico en el lienzo en blanco y la tabula rasa se pone en relación con el concepto de ‘terrain vague’. Por último, la posibilidad de toda potencia de no actualizarse lleva a explorar el no-hacer como renuncia voluntaria y su capacidad de transformarse en acto de resistencia. ABSTRACT The concern of this research is to test the feasibility of a term, a concept that has been detected as a potential tool to name some architectural operations. That concept is the Neutral. In front of the dualities system with which we enounce the real, the Neutral places itself, not so much in the midpoint as in the opposite point of both terms. It is not the conjunction of the contraries, but that which deflects the question itself that compels us to make a choice. Recognizing the multiple interpretations of the term in the common language, with each chapter, the thesis builds an expanded definition of the Neutral to configure a set of meanings applicable to architecture. The first of them is the one that derives from the concept of functional indifference. After an analysis of the theoretical context in which the two-way dialectic between form and function lies, its consolidation in the early twentieth century and its call into crisis by the introduction of multi-relational concepts such as 'environment' and 'system', the research suggests three study models: the Typical Plan, the Single Plan and the Equivalents Plan. In each of these cases, although the fundamental issue is programmatic neutrality, it also recognizes the presence of geometric mechanisms and conceptual operations that the Neutral uses to generate respectively 'support', 'frame' or 'field' conditions. These three spatial conditions point to an understanding of the Neutral which associates its double negation formula (neither one nor the other) with the most incipient state of matter, that in which it not yet is, but already contains every element of the possibility of being: the neutral as potentiality. That which logic does not allow us to affirm, that one thing is and is-not at the same time, it is granted by the Aristotelian category of potentiality. Therefore, in the last part of the thesis, the topics relating these three types of space which are based on renouncement are more autonomously developed, addressing the issue of potentiality from the standpoint of denial. Starting from two basic surface conditions, the vertical wall and the horizontal floor, some speeches based on a radical restriction on these two elements are analyzed. Thus, the blind wall finds its artistic precedent in the blank canvas and the tabula rasa attitude gets in relation to the concept of ‘terrain vague’. Finally, the possibility of any potency of not being updated leads to explore the not-doing as voluntary resignation and its ability to transform itself into an act of resistance.
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Deoxyribonucleic guanidine is a potential antisense agent that is generated via the replacement of the negative phosphodiester linkages of DNA [--O--(PO2-)--O--] with positively-charged guanidinium (g) linkages [--NH--C(==NH2+)--NH--]. A pentameric thymidyl deoxyribonucleic guanidine molecule [d(Tg)4T-azido] has been shown to base pair specifically to poly(rA) with an unprecedented affinity. Both double and triple strands consisting of one and two equivalents of d(Tg)4T-azido paired with one equivalent of poly(rA) are indicated by thermal denaturation experiments. At an ionic strength of 0.22, the five bases of d(Tg)4T-azido are estimated to dissociate from a double helix with poly(rA) at > 100 degrees C! The effect of ionic strength on thermal denaturation is very pronounced, with stability greatest at low ionic strengths. The method of continuous variation indicates that there is an equilibrium complex with a molar ratio of d(Tg) to r(Ap) or d(Ap) of 2:1. Based on this evidence, models of the structures of d(Tg)9T-azido bound to r(Ap)9A are proposed.
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[Mehmed Esad].
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Turkish (in Armenian script) with classical Armenian and French equivalents.
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Background: In the field of Plastic Reconstructive Surgery the development of new innovative matrices for skin repair is in urgent need. The ideal biomaterial should promote attachment, proliferation and growth of cells. Additionally, it should degrade in an appropriate time period without releasing harmful substances, but not exert a pathological immune response. Spider dragline silk from Nephila spp meets these demands to a large extent. Methodology/Principal Findings: Native spider dragline silk, harvested directly out of Nephila spp spiders, was woven on steel frames. Constructs were sterilized and seeded with fibroblasts. After two weeks of cultivating single fibroblasts, keratinocytes were added to generate a bilayered skin model, consisting of dermis and epidermis equivalents. For the next three weeks, constructs in co-culture were lifted on an originally designed setup for air/liquid interface cultivation. After the culturing period, constructs were embedded in paraffin with an especially developed program for spidersilk to avoid supercontraction. Paraffin cross-sections were stained in Haematoxylin & Eosin (H&E) for microscopic analyses. Conclusion/Significance: Native spider dragline silk woven on steel frames provides a suitable matrix for 3 dimensional skin cell culturing. Both fibroblasts and keratinocytes cell lines adhere to the spider silk fibres and proliferate. Guided by the spider silk fibres, they sprout into the meshes and reach confluence in at most one week. A well-balanced, bilayered cocultivation in two continuously separated strata can be achieved by serum reduction, changing the medium conditions and the cultivation period at the air/liquid interphase. Therefore spider silk appears to be a promising biomaterial for the enhancement of skin regeneration.
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The financial and economic analysis of investment projects is typically carried out using the technique of discounted cash flow (DCF) analysis. This module introduces concepts of discounting and DCF analysis for the derivation of project performance criteria such as net present value (NPV), internal rate of return (IRR) and benefit to cost (B/C) ratios. These concepts and criteria are introduced with respect to a simple example, for which calculations using MicroSoft Excel are demonstrated.
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This article examines the effects of commercialisation of agriculture on land use and work patterns by means of a case study in the Nyeri district in Kenya. The study uses cross sectional data collected from small-scale farmers in this district. We find that good quality land is allocated to non-food cash crops, which may lead to a reduction in non-cash food crops and expose some households to greater risks of possible famine. Also the proportion of land allocated to food crops declines as the farm size increases while the proportion of land allocated to non-food cash crops rises as the size of farm increases. Cash crops are also not bringing in as much revenue commensurate with the amount of land allocated to them. With growing commercialisation, women still work more hours than men. They not only work on non-cash food crops but also on cash crops including non-food cash crops. Evidence indicates that women living with husbands work longer hours than those married but living alone, and also longer than the unmarried women. Married women seem to lose their decision-making ability with growth of commercialisation, as husbands make most decisions to do with cash crops. Furthermore husbands appropriate family cash income. Husbands are less likely to use such income for the welfare of the family compared to wives due to different expenditure patterns. Married women in Kenya also have little or no power to change the way land is allocated between food and non-food cash crops. Due to deteriorating terms of trade for non-food cash crops, men have started cultivation of food cash crops with the potential of crowding out women. It is found that both the area of non-cash crops tends to rise with farm size but also the proportion of the farm area cash cropped rises in Central Kenya.
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This article examines the effects of marital status, farm size and other factors on the extent of cash cropping (and allocation of land use) by means of a case study in the Nyeri district in Kenya. It was found that married women are involved in the production of a relatively greater amount of output of cash crops than unmarried women since husbands prefer to have more land under cash crops than food crops. Farmers with better quality land allocate a high proportion of it to non-food cash crops, which may expose some households to greater risks of possible famine. The proportion of land allocated to food crops declines as the farm size increases while the proportion of land allocated to non-food cash crops rises as the size of farm increases. Age is also inversely associated with subsistence. Education, though inversely associated with subsistence farming does not appear to be statistically very significant as an influence on the composition of land use and composition of farm output. With growing commercialisation, married women work more hours than unmarried ones, working not only on non-cash food crops but also on non-food cash crops. Married women seem to lose their decision-making ability with growth of agricultural commercialisation, as husbands make most decisions to do with cash crops. Married women in Kenya also have little or no power to change the way land is allocated between food and non-food cash crops.