520 research outputs found
Configurations of business model themes and strategies in small firms: a qualitative comparative analysis
Firms' strategies and business model themes (BMTs) entail choices that create a configuration of interdependent elements that ultimately affect a firm's performance. So far, extant studies on BMTs (i.e. novelty, efficiency, complementarity and lock-in) have neglected an explorative analysis of how configurations of BMTs and the choices of a firm's strategy (namely, the source of the competitive advantage and the market scope) are associated with a firm's performance in small and medium enterprises (SMEs). We address this limitation by analysing a sample of 96 small firms using a configurational approach. We identified four equifinal configurations leading to high performance and five equifinal configurations associated with low performance. Overall, our results suggest that in small firms, it is essential to combine a differentiation strategy with either consistent pairs of BMTs or the search for new avenues of value creation and capture, while featuring too many BMTs might be detrimental to their growth. Our study contributes to the scholarly debate about the relationship between business models and strategy
Characterisation of Hybrid Pixel Detectors with capacitive charge division
In order to fully exploit the physics potential of the future high energy e+
e- linear collider, a Vertex Tracker providing high resolution track
reconstruction is required. Hybrid pixel sensors are an attractive technology
due to their fast read-out capabilities and radiation hardness. A novel pixel
detector layout with interleaved cells between the readout nodes has been
developed to improve the single point resolution. The results of the
characterisation of the first processed prototypes are reported.Comment: 5 pages, 2 figures, presented at LCWS2000, Linear Collider Workshop,
October 24-28 2000, Fermi National Accelerator Laboratory, Batavia, Illinois,
U.S.A. Proceedings to be published by the American Institute of Physic
Fatigue strength of austempered ductile iron-to-steel dissimilar arc-welded joints
Nowadays, the use of different classes of materials in the same structure is increased to keep pace with innovation and high structural performances. In this context, structural components made of different materials need to be joined together and a possible solution is given by arc welding. Dissimilar welded joints must often be able to withstand fatigue loads; however, Design Standards provide fatigue strength categories only for homogeneous welded joints. The aim of the present paper is to compare the fatigue behaviour of EN-GJS-1050 austempered ductile iron-to-S355J2 steel dissimilar joints to the categories of the corresponding homogeneous steel welded joints, as suggested in International Standards and Recommendations. For this purpose, experimental fatigue tests were performed on a selection of dissimilar welded details. First, the microstructure was identified by metallographic analysis; micro-hardness measurements were collected and residual stress profiles were obtained by using the X-ray diffraction technique on a selection of joints. Misalignments were quantified for all specimens. Then, experimental fatigue tests have been performed on a number of joint geometries subject to axial or bending fatigue loadings and tested in the as-welded conditions. The fracture surfaces of the joints have been analysed to locate fatigue crack nucleation sites
Large-Eddy Simulation of Waked Turbines in a Scaled Wind Farm Facility
The aim of this paper is to present the numerical simulation of waked scaled wind turbines operating in a boundary layer wind tunnel. The simulation uses a LES-lifting-line numerical model. An immersed boundary method in conjunction with an adequate wall model is used to represent the effects of both the wind turbine nacelle and tower, which are shown to have a considerable effect on the wake behavior. Multi-airfoil data calibrated at different Reynolds numbers are used to account for the lift and drag characteristics at the low and varying Reynolds conditions encountered in the experiments. The present study focuses on low turbulence inflow conditions and inflow non-uniformity due to wind tunnel characteristics, while higher turbulence conditions are considered in a separate study. The numerical model is validated by using experimental data obtained during test campaigns conducted with the scaled wind farm facility. The simulation and experimental results are compared in terms of power capture, rotor thrust, downstream velocity profiles and turbulence intensity
A Pixel Vertex Tracker for the TESLA Detector
In order to fully exploit the physics potential of a e+e- linear collider,
such as TESLA, a Vertex Tracker providing high resolution track reconstruction
is required. Hybrid Silicon pixel sensors are an attractive sensor technology
option due to their read-out speed and radiation hardness, favoured in the high
rate TESLA environment, but have been so far limited by the achievable single
point space resolution. A novel layout of pixel detectors with interleaved
cells to improve their spatial resolution is introduced and the results of the
characterisation of a first set of test structures are discussed. In this note,
a conceptual design of the TESLA Vertex Tracker, based on hybrid pixel sensors
is presentedComment: 20 pages, 11 figure
Wind shear estimation and wake detection by rotor loads - First wind tunnel verification
The paper describes a simple method for detecting presence and location of a wake affecting a downstream wind turbine operating in a wind power plant. First, the local wind speed and shear experienced by the wind turbine are estimated by the use of rotor loads and other standard wind turbine response data. Then, a simple wake deficit model is used to determine the lateral position of the wake with respect to the affected rotor. The method is verified in a boundary layer wind tunnel using two instrumented scaled wind turbine models, demonstrating its effectiveness
Experimental tests and fatigue strength assessment of a scotch yoke valve actuator
Abstract Aim of this work is the fatigue assessment of a main component, termed scotch yoke, of a valve actuator used for oil & gas, power and chemical industries, in order to comply with its heavy-duty applications. To do this, full-scale specimens of the scotch yoke made of structural steel have been fatigue tested under nominal axial loading. All specimens have been tested under stress-relieved conditions by adopting a nominal load ratio R=-1. After experimental tests, the fatigue crack paths have been analysed by means of liquid penetrant inspections. The fatigue strength class of the considered scotch yoke has been determined by statistically re-analysing the experimental results, expressed in terms of range of the nominal applied load, and it has been compared with the design condition required by the relevant European Standard, EN 15714-3/4. Finally, two methodologies for fatigue strength assessment of the considered scotch yokes have been proposed, which are based on experimental fatigue data derived from smooth or sharp V-notched specimens, respectively, made of the same yoke material. The assessment capability of the proposed methodologies has been evaluated and discussed by comparing theoretical estimations with the experimental fatigue results of the scotch yokes
Osteogenesis Imperfecta â Experience of Dona EstefĂąniaâs Hospital Orthopedicsâ Department
Introdução/Objectivos: A osteogĂ©nese imperfeita (OI) Ă© uma doença genĂ©tica caracterizada por fragilidade Ăłssea e osteopenia. O tratamento implica uma abordagem multidisciplinar e tem como objectivo a melhoria da qualidade de vida. Os autores pretendem descrever as caracterĂsticas de uma amostra de crianças com OI, avaliar o tratamento realizado e a evolução clĂnica prĂ© e pĂłs terapĂȘutica.
Material e MĂ©todos: Estudo observacional, longitudinal, retrospectivo e analĂtico, com base nos dados obtidos da consulta dos processos de todos os doentes com OI incluĂdos no protocolo de tratamento com pamidronato no Hospital Dona EstefĂąnia. As variĂĄveis estudadas foram: sexo, idade de diagnĂłstico, antecedentes familiares de OI, idade de fractura, localização da fractura, nĂșmero de fracturas, terapĂȘutica mĂ©dica/cirĂșrgica, idade de inĂcio do tratamento mĂ©dico, nĂșmero de ciclos de terapĂȘutica mĂ©dica, idade da terapĂȘutica cirĂșrgica, complicaçÔes da terapĂȘutica cirĂșrgica. Adoptou-se um nĂvel de significĂąncia de 5%.
Resultados: De 21 doentes, 61,9% eram do sexo masculino e 11 tinham registado o diagnĂłstico do tipo de OI (cinco do tipo I, trĂȘs tipo III, trĂȘs tipo IV). A idade mĂ©dia de diagnĂłstico foi de 20,6 meses, verificando-se dois picos diagnĂłsticos: no primeiro mĂȘs â 37%, e aos 24 meses - 26%. Em mĂ©dia os doentes apresentaram 0,62 fracturas/doente/ano, 17,4% das quais no perĂodo perinatal e 62% antes dos trĂȘs anos de idade. A maioria das fracturas ocorreu nos membros inferiores (55,6%). Todos os doentes realizaram tratamento mĂ©dico, com inĂcio em mĂ©dia aos 4,3 anos. Na amostra com seguimento (n=14) verificou-se diminuição no nĂșmero de fracturas apĂłs o inĂcio do tratamento com pamidronato (de 0,76 para 0,35 fracturas/doente/ano). Foram colocadas cavilhas endomedulares em nove doentes (64,3%). Em oito doentes foram colocadas nos fĂ©mures, quatro unilaterais e quatro bilaterais, nĂŁo existindo antecedentes de
fractura em trĂȘs casos. NĂŁo se registaram novas fracturas nos ossos encavilhados.
ConclusĂŁo: A OI Ă© uma doença com uma ampla variabilidade clĂnica que depende maioritariamente do seu tipo. Apesar de nĂŁo existir tratamento curativo, o tratamento mĂ©dico com bifosfonatos e o tratamento cirĂșrgico, com colocação de cavilhas endomedulares, parece reduzir a incidĂȘncia de novas fracturas
Modularization as a system life cycle management strategy:Drivers, barriers, mechanisms and impacts
This literature-grounded research contributes to a deeper understanding of modularization as a system life cycle management strategy, by providing a comprehensive view of its key barriers, drivers, possible mechanisms of implementation and impact. This comprehensive view, arranged into a decision-makingâdriven ontology, enables a decision maker to systematically identify modularization implementation opportunities in different industrial and service domains. The proposed ontology transforms modularization into a fully operationalizable strategy and contributes to a paradigm shift in the understanding of modularization, from a pure design option (i.e. modularity) to a fully strategic choice that, by nature, impacts on many of the systemâs life cycle phases and involves a number of stakeholders
Produção da amoreira-preta âTupyâ sob diferentes Ă©pocas de poda.
A amora-preta Ă© uma opção importante para fruticultura paranaense, porĂ©m nĂŁo hĂĄ informaçÔes a respeito do cultivo dessa frutĂfera nas condiçÔes subtropicais do Estado. O objetivo deste trabalho foi avaliar a influĂȘncia da Ă©poca de poda na produção da amoreira-preta âTupyâ. O trabalho foi realizado em um pomar comercial, conduzido em sistema agroecolĂłgico. O delineamento experimental foi em blocos ao acaso, com quatro blocos e seis tratamentos (podas quinzenais realizadas durante o inverno). Em cada parcela, constituĂda de trĂȘs plantas Ășteis, foram coletados dados fenolĂłgicos, produtivos e fĂsico-quĂmicos no ciclo de produção 2008/09 e
2009/10. Podas efetuadas no inĂcio de julho sĂŁo as mais indicadas e podas tardias podem prejudicar o desempenho produtivo das amoreiras-pretas âTupyâ no oeste do ParanĂĄ
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