2,787 research outputs found
Marketing in Online Businesses:The Case of Migrant Entrepreneurial Businesses in the UK
The study presents an empirical investigation of the marketing activities undertaken by online businesses owned by migrant entrepreneurs and is framed by the theoretical lens of entrepreneurial marketing. Key informant interviews are undertaken with 22 entrepreneurs operating online businesses in the UK and augmented by other sources of data. The study finds that the resources available to the entrepreneurs are shaped by their migrant heritage and that they draw on these resources to market their online businesses. The study also finds that, consistent with notions from entrepreneurial marketing, the online nature of their businesses allow the entrepreneurs to meet their own needs and preferences, which are also shaped by their migrant heritage. The study is important since it provides empirical evidence and a theoretically grounded understanding of how online businesses offer migrant entrepreneurs the opportunity to break out of the low growth, low margin, vacancy chain openings and enter high growth, high margin, post-industrial sectors
Developing high performance and stable hetero-structured cathodes and fundamental understanding of oxygen reduction and reaction behavior
New hetero-structured La2NiO4+delta (LNO)/ (La0.6Sr0.4)0.95Co0.2Fe0.8O3-delta (LSCF) SOFC cathodes have been successfully fabricated by the infiltration technique for long-term stability and oxygen reduction reaction (ORR) kinetic consideration. The current comparative study of LSCF and LNO-infiltrated LSCF shows a significant reduction in polarization resistance by one order of magnitude and a 67% increase in maximum power density by using LNO-infiltrated LSCF cathodes at 750°C in air. The electronic conductivity relaxation (ECR) results demonstrate that the remarkable improved oxygen exchange properties of LNO/LSCF hetero-structured cathodes are attributed to not only the increase of surface reaction area, but also the introduction of LNO surface and LNO-LSCF interface with rapid oxygen exchange behavior. A trace amount of Co, Sr and more oxygen defects stabilized in the LNO layer have been identified by TEM, EDXS, XPS, XRD and iodine titration experiments, giving rise to the enhancement of stability and surface catalytic activity. A low degradation rate of 0.39% at a constant current density of 250 mAdeltacm-2 can be still achieved for the fuel cell using LNO-infiltrated LSCF cathodes after long-term durability of about 500 h at 750°C, accompanied by nanoparticles growth/aggregation, delamination and slight lanthanum enrichment on LNO surfaces. The benefits from the presence of the LNO nanoparticles demonstrate that LNO-infiltrated LSCF materials can act as high active surface oxygen exchange cathodes with promising fast ORR behavior and stability.;To further enhance the long-term stability of infiltrated (La0.6Sr0.4)0.95Co0.2Fe0.8O3-delta (LSCF) cathode, two kinds of new hetero-structured cathodes, CeO2 & LNO co-infiltrated LSCF and La2-xNiO4+delta-infiltrated LSCF, have been designed. La2NiO4+delta (LNO), as an superior performance promoter, and CeO2, as a particle growth retardant due to the high melting point and good wettability, were co-infiltrated into the LSCF backbone to mitigate the delamination and growth/aggregation of in-situ formed nano-sized infiltrants. A more advantageous microstructure was confirmed in the co-infiltrated sample relative to those infiltrated with LNO alone. The original morphology was largely retained in the co-infiltrated sample after heat treatment, showing finer surface particles, better connection between the infiltrant network and the LSCF backbone. XPS and EIS results reveal that the substitution of stoichiometric La2NiO4+delta by A-site deficient La2-xNiO4+delta can effectively suppress lanthanum enrichment and enhance the stability after cathodic polarization treatment observed by measurement. The advantages of both modified hetero-structured cathodes suggest that CeO2 & La2-xNiO4+delta co-infiltrated LSCF is a promising hetero-structured cathode to mitigate the LSCF electrode degradation
U.S. Agricultural Labor Out-migration Determinants, 1939-2004
Replaced with revised version of paper 06/01/06.Labor and Human Capital,
Migration, Money and Mother: The Effect of Migration on Children's Educational Performance in Rural China
Migration is widely known as one of the main ways of alleviating poverty in developing countries, including China. However, migration itself is not costless. In recent years, there is an emerging concern about the effect of migration on the educational achievement of the children of migrants in China since most of the young children of school age of the migrants are being left in the village when one or both of their parents move to the city to work. This paper examines the effect of the migration activities of the father and/or mother on the educational performance of elementary school students (First to Fifth grade). With a dataset that collected from a survey designed specifically to examine changes in school performance of children before and after their parents left the village to migrate to the city we use Difference-in-Difference and, propensity score matching approaches. Although the grades of the children from some migrants family are sometimes lower than those from non-migrants family (in the time period before and after migration), somewhat surprisingly, we find that there is no significant negative effect of migration itself on the childrens school performance. In fact, in some cases (e.g., after the father migrates), performance improves. Our paper also demonstrates and explains the interaction effects of migration from wealth and household composition.Labor and Human Capital,
Functional Modelling for Fault Diagnosis and its application for NPP.
The paper presents functional modelling and its application for diagnosis in nuclear power plants. Functional modelling is defined and its relevance for coping with the complexity of diagnosis in large scale systems like nuclear plants is explained. The diagnosis task is analyzed and it is demonstrated that the levels of abstraction in models for diagnosis must reflect plant knowledge about goals and functions which is represented in functional modelling. Multilevel flow modelling (MFM), which is a method for functional modelling, is introduced briefly and illustrated with a cooling system example. The use of MFM for reasoning about causes and consequences is explained in detail and demonstrated using the reasoning tool, the MFMSuite. MFM applications in nuclear power systems are described by two examples: a PWR; and an FBR reactor. The PWR example show how MFM can be used to model and reason about operating modes. The FBR example illustrates how the modelling development effort can be managed by proper strategies including decomposition and reuse
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