997 resultados para LARGE-PORE
Resumo:
This paper examines the proposition that the traditional archetype of the professional partnership is said to have changed into a more 'business-like' entity, the managed professional business. It broadens the restricted case sample base on which much of the evidence has been adduced, by developing a survey questionnaire through which 197 large British law firms were sampled. Change, consistent with the notion of a more commercially oriented and consciously managed organization, is concentrated in the market-facing area of the firm but coexists with areas of continuity in the governance of the firm and its strategic management. The findings reveal a more managerial form of organization in which the core elements of the traditional form of professional organization have not been transformed. These results contest the assertion of either transformational or sedimented change found in other, case-based research and suggest that archetype change needs theoretically to be distinguished from the general phenomenon of greater managerialism within the professional service firm.
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The Lanczos algorithm is appreciated in many situations due to its speed. and economy of storage. However, the advantage that the Lanczos basis vectors need not be kept is lost when the algorithm is used to compute the action of a matrix function on a vector. Either the basis vectors need to be kept, or the Lanczos process needs to be applied twice. In this study we describe an augmented Lanczos algorithm to compute a dot product relative to a function of a large sparse symmetric matrix, without keeping the basis vectors.
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A thorough investigation was performed on the physical (mechanical, thermal, and hydrothermal stability) and chemical (ion exchange capacity and silanol number) characteristics of aluminosilicate FSMs, synthesized via a new successful short-time synthesis route using leached saponite and a low concentration of CTAB. Moreover, the influence of an additional Al incorporation, utilizing different aluminum sources, on the structure of the FSM derived from saponite is studied. A mesoporous aluminosilicate with a low Si/Al ratio of 12.8 is synthesized, and still has a very large surface area of 1130 m(2)/g and pore volume of 0.92 cm(3)/g. The aluminum-containing samples all have a high cation exchange capacity of around 1 mmol/9 while they still have a silanol number of about 0.9 OH/nm(2); both characteristics being interesting for high-yield postsynthesis modification reactions. Finally, a study is performed on the transformation of the aluminosilicates into their Bronsted acid form via the exchange with ammonium ions and a consecutive heat treatment.
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Background: The heavy usage of coxibs in Australia far outstrips the predicted usage that was based on the treatment of patients with risk factors for upper gastro-intestinal adverse events from conventional anti--inflammatory agents. This raises questions regarding the appropriateness of prescribing. Aims: To determine: (i) the relationship between prescriptions for cyclooxygenase 2 (COX-2) inhibitors and objective evidence of inflammatory arthritis, (ii) prior experience with paracetamol and/or conventional non-steroidal anti-inflammatory drugs (NSAIDs), and (iii) contraindications to the use of NSAIDs. Methods: Drug utilization evaluation and rheumato-logical assessment was conducted on 70 consecutive patients admitted on COX-2 inhibitors to a 480-bed metropolitan hospital. The main outcome measures were: the indication for COX-2 inhibitor; objective -evidence of inflammatory arthritis; previous trial of -paracetamol or conventional NSAIDs; and patient -satisfaction. Results: Only 11 patients (16%) had symptoms or signs of an inflammatory arthropathy, and met Pharmaceut-ical Benefits Schedule criteria for prescribing a COX-2 inhibitor. Fifty-nine patients (84%) had chronic osteo-arthritis, degenerative spinal disease, injury or malignancy, without overt active inflammation. Fourteen patients (20%) had trialled regular paracetamol prior to using any NSAID treatment. Conventional NSAIDs had been previously used by 51 patients (73%). Eleven patients (16%) reported previous adverse gastrointestinal effects from conventional NSAIDs. On the basis of significant renal impairment (creatinine clearance 5/10). Conclusions: Drug utilization data indicate that COX-2 inhibitors are frequently used first line for degenerative osteoarthritis in the absence of overt inflammation, without prior adequate trial of paracetamol and with disregard for the cautions and contraindications of these agents. These findings may explain the unprecedented Pharmaceutical Benefits Schedule expenditure on COX-2 inhibitors in Australia.
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This paper presents a large amplitude vibration analysis of pre-stressed functionally graded material (FGM) laminated plates that are composed of a shear deformable functionally graded layer and two surface-mounted piezoelectric actuator layers. Nonlinear governing equations of motion are derived within the context of Reddy's higher-order shear deformation plate theory to account for transverse shear strain and rotary inertia. Due to the bending and stretching coupling effect, a nonlinear static problem is solved first to determine the initial stress state and pre-vibration deformations of the plate that is subjected to uniform temperature change, in-plane forces and applied actuator voltage. By adding an incremental dynamic state to the pre-vibration state, the differential equations that govern the nonlinear vibration behavior of pre-stressed FGM laminated plates are derived. A semi-analytical method that is based on one-dimensional differential quadrature and Galerkin technique is proposed to predict the large amplitude vibration behavior of the laminated rectangular plates with two opposite clamped edges. Linear vibration frequencies and nonlinear normalized frequencies are presented in both tabular and graphical forms, showing that the normalized frequency of the FGM laminated plate is very sensitive to vibration amplitude, out-of-plane boundary support, temperature change, in-plane compression and the side-to-thickness ratio. The CSCF and CFCF plates even change the inherent hard-spring characteristic to soft-spring behavior at large vibration amplitudes. (C) 2003 Elsevier B.V. All rights reserved.
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We describe a direct method of partitioning the 840 Steiner triple systems of order 9 into 120 large sets. The method produces partitions in which all of the large sets are isomorphic and we apply the method to each of the two non-isomorphic large sets of STS(9).
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The variation of the crystallite structure of several coal chars during gasification in air and carbon dioxide was studied by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) techniques. The XRD analysis of the partially gasified coal chars, based on two approaches, Scherrer's equation and Alexander and Sommer's method, shows a contradictory trend of the variation of the crystallite height with carbon conversion, despite giving a similar trend for the crystallite width change. The HRTEM fringe images of the partially gasified coal chars indicate that large and highly ordered crystallites exist at conversion levels as high as 86%. It is also demonstrated that the crystalline structure of chars can be very different although their pore structures are similar, suggesting a combination of crystalline structure analysis with pore structure analysis in studies of carbon gasification.
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The variation of the pore structure of several coal chars during gasification in air and carbon dioxide was studied by argon adsorption at 87 K and CO2 adsorption at 273 K. It is found that the surface area and volume of the small pores (10 Å for air gasification is constant over a wide range of conversion (>20%), while for CO2 gasification similar results are obtained using the total surface area. However, in the early stages of gasification (
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Thermoplastic elastomer/carbon nanotube composites are studied for sensor applications due to their excellent mechanical and electrical properties. Piezoresisitive properties of tri-block copolymer styrene-butadiene-styrene (SBS)/ carbon nanotubes (CNT) prepared by solution casting have been investigated. Young modulus of the SBS/CNT composites increases with the amount of CNT filler content present in the samples, without losing the high strain deformation on the polymer matrix (~1500 %). Further, above the percolation threshold these materials are unique for the development of large deformation sensors due to the strong piezoresistive response. Piezoresistive properties evaluated by uniaxial stretching in tensile mode and 4-point bending showed a Gauge Factors up to 120. The excellent linearity obtained between strain and electrical resistance makes these composites interesting for large strain piezoresistive sensors applications.
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Similarly to what has happened in other countries, since the early 1990s Portuguese companies have developed corporate environmental reporting practices in response to internal and external factors. This paper is based on empirical research directed to both the study of environmental reporting practices developed by Portuguese companies and the identification of the factors that explain the extent to which these companies disclose environmental information. This study focuses on the environmental disclosures made in the annual reports by a sample of 109 large firms operating in Portugal during the period 2002-04. Using the content analysis technique we have developed an index in order to assess the presence of the environmental disclosures in companies’ annual reports and their breadth. Based on the extant literature, several characteristics relating to firms’ attributes were selected and their influence on the level of environmental disclosure was tested empirically. The selected explanatory variables were firm size, industry membership, profitability, foreign ownership, quotation on the stock market and environmental certification. The results reveal that, in spite of the fact that the level of environmental information disclosed during the period 2002-04 is low, the extent of environmental disclosure has increased as well as the number of Portuguese companies that disclose environmental information. Moreover, the firm size and the fact that a company is listed on the stock market are positively related to the extent of environmental disclosure. This study adds to the international research on environmental disclosure by providing empirical data from a country, Portugal, where empirical evidence is still relatively unknown, extending the scope of the current understanding of the environmental reporting practices.
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When companies opt for information systems (IS) outsourcing, within the set of contracted services, they can contract their entire service needs to onshore suppliers or to offshore companies, or part of these services can be contracted to onshore suppliers and the other part to offshore suppliers. The offshore outsourcing reveals itself nowadays as an important strategic option to IS management optimization. This paper presents and discusses the main results of a survey that was carried out in Portugal to determine several aspects of offshore practice in large companies. It allowed the identification of the services more frequently contracted, the most common motivations for choosing offshore suppliers and the main risks perceived by companies. This research contributes to a better understanding of the IS offshore market, enabling client companies and vendors to improve their strategic business action.
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LUDA is a research project of Key Action 4 "City of Tomorrow & Cultural Heritage" of the programme "Energy, Environment and Sustainable Development" within the Fifth Framework Programme of the European Commission.
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LUDA is a research project of Key Action 4 "City of Tomorrow & Cultural Heritage" of the programme "Energy, Environment and Sustainable Development" within the Fifth Framework Programme of the European Commission
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LUDA is a research project of Key Action 4 "City of Tomorrow & Cultural Heritage" of the programme "Energy, Environment and Sustainable Development" within the Fifth Framework Programme of the European Commission