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The analysis of strategies that enterprises take in the financial crisisTsai, Hui-ju 18 July 2010 (has links)
During Nov.2008 to Apr. 2009, firms in Taiwan encountered dramatic financial crisis, and this impact made unemployment rate still climbing and economic depression. In order to reduce the impact from financial tsunami, every firm takes some strategies to resist it. The objective of our study is to find out the influence from financial tsunami on the listed companies. More importantly, we base on the three mechanisms (mimetic force, normative force and coercive force) of institutional theory and the perspectives of population theory to analyze why firms choose those strategies.
We collect and analyze 201 returned questionnaires. We find when firms face both high market force, mimetic force and coercive, they tend to choose manipulation strategies. When firms face both low market force, mimetic force and coercive force, they tend to choose compromise strategies. When firms face high market force and low mimetic force and coercive force, they tend to use defiance strategies. When firms face low market force and high mimetic force and coercive force, they tend to use acquiescence strategies.
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The analysis of strategies firms choose under the financial crisis-Evidence form stock exchange and OTC companiesWen, Kai-hsiang 22 February 2011 (has links)
In 2008-2009, firms in Taiwan encountered dramatic financial tsunami, and this crisis made unemployment rate still climbing and economic depression. In order to reduce the impact from financial tsunami, every firm chooses some strategies to resist it. The purpose of our study is to find out the influence from financial tsunami on the listed companies. More importantly, we base on the three mechanisms (mimetic force, normative force and coercive force) of institutional theory to analyze the real reason for choosing strategies.
We collect and analyze 201 returned questionnaires. The finding of this study is that the main factor of choosing strategies is from the mimetic force and normative force. In fact, the enterprise is affected by mimetic pressure deeply, and then it would tend to use the passive strategies. The enterprise is affected by normative pressure deeply, and then it would tend to use the active strategy. Interestingly, whether the enterprise is affected by coercive pressure or not, it doesn¡¦t affect the strategies choosing.
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Computational simulations of thermally activated magnetisation dynamics at high frequenciesHannay, Jonathan David January 2001 (has links)
No description available.
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Transmission electron microscopy study of nanostructured Nd-Fe-B hard magnetic materialsMarashi, Seyed Pirooz Hoveida January 2001 (has links)
No description available.
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The magnetic and magnetoelastic properies of meld-spun MbFe2 based alloys and their temperature dependenciesJerems, Frank January 1999 (has links)
No description available.
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Estudo das propriedades e microestrutura de ímãs permanentes de Pr-Fe-B-(Co-Nb) preparados pelo processo de hidrogenação, desproporção, dessorção e recombinação (HDDR)BARBOSA, LUZINETE P. 09 October 2014 (has links)
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Estudo da microestrutura e propriedades de ligas magneticas e imas permanentes de terras raras - metais de transicao - boro processados com hidrogenioTAKIISHI, HIDETOSHI 09 October 2014 (has links)
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Estudo das propriedades e microestrutura de ímãs permanentes de Pr-Fe-B-(Co-Nb) preparados pelo processo de hidrogenação, desproporção, dessorção e recombinação (HDDR)BARBOSA, LUZINETE P. 09 October 2014 (has links)
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10553.pdf: 9807833 bytes, checksum: fcd7e02a22a70e9ee79a1dcccaf7f496 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Estudo da microestrutura e propriedades de ligas magneticas e imas permanentes de terras raras - metais de transicao - boro processados com hidrogenioTAKIISHI, HIDETOSHI 09 October 2014 (has links)
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07542.pdf: 8778356 bytes, checksum: 4518d6e06c451cc0d8b83aa7b2a1ac53 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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Magnetic anisotropy and coercivity of tetragonally distorted spinel ferrite particles via the Jahn-Teller distortion and the magnetoelastic coupling / Anisotropie magnétique et coercivité de particules de ferrite spinelle déformées de façon tétragonale via l'effet Jahn-Teller et le couplage magnétoélastiqueAbdul Latiff, Hawa Alima Binti 13 February 2019 (has links)
Cette étude propose l'idée des aimants dits de ferrite tétragonale en rendant la symétrie cristalline des ferrites de spinelle cubique afin d'améliorer l'anisotropie magnétique (et donc, d'améliorer la coercivité). Pour concrétiser cette idée, nous avons synthétisé des particules (Cu, Co) -ferrite à distorsion tétragonale et caractérisé systématiquement les propriétés magnétiques en conséquence avec leurs distorsions de réseau. Les facteurs intrinsèques et extrinsèques contribuant à la coercivité ont été étudiés. Pour élucider l'anisotropie magnétique, nous avons démontré un modèle de couplage physique de l'effet Jahn-Teller (JT) et de l'effet magnétoélastique (ME) au sein de la théorie phénoménologique. Ensuite, nous avons effectué une analyse de coercivité dans deux modèles généraux de coercivité afin de clarifier les paramètres de la microstructure contribuant au mécanisme d'inversion de la magnétisation. À partir de l'analyse du modèle magnétoélastique, nous avons démontré l'expression linéaire de l'anisotropie magnétique en utilisant le paramètre tétragonal obtenu à partir de la distorsion JT. Les valeurs du coefficient magnétoélastique pour Cu (B1Cu = 2 MJ / m3) et Co (B1Co = 40 MJ / m3) déduites de la courbe expérimentale étaient acceptables avec la valeur calculée pour le ferrite de cuivre en vrac (B1Cu en vrac = 4 MJ / m3) et le cobalt. ferrite (masse B1Co = 55 MJ / m3). Les résultats suggèrent que l’anisotropie magnétique peut être attribuée au couplage de la distorsion JT avec l’effet magnétoélastique de Co. Au lieu d’une augmentation indéfinie avec x, l’anisotropie magnétique Ku tend à atteindre une valeur de saturation en raison de la concurrence entre les effet magnétoélastique de Co et le JT de Cu. Entre le x tétragonal x = 0,1 et le x cubique = 0,2, les valeurs de Ku constantes d'anisotropie magnétique intrinsèque ne varient pas de manière aussi significative que la différence entre les champs de coercivité et d'anisotropie. La réduction des champs d'anisotropie supérieurs à x = 0,1 peut alors être attribuée à l'augmentation de l'aimantation spontanée. L'analyse de la coercivité au sein du modèle micromagnétique a révélé une contribution importante à la coercivité de la microstructure et de l'effet démagnétisant local. Le paramètre de microstructure αMM = 0,25 obtenu était une valeur classique de l'analyse micromagnétique, suggérant le départ du champ d'anisotropie avec ce facteur de réduction. Les facteurs démagnétisants locaux effectifs NeffMM d’environ 1,4 obtenus étaient plutôt importants, ce qui suggère un effet démagnétisant significatif. Dans l'analyse du modèle global (GM), les valeurs de NeffGM obtenues étaient were 0,38 pour l'échantillon x = 0,1. La valeur négative suggère la présence d'une interaction d'échange agissant efficacement en opposition à l'interaction dipolaire. En deçà de 100 K, une différence dans le modèle suggère l’idée d’un réchauffement local consécutif à l’activation thermique due au changement d’énergie Zeeman et à une dissipation de chaleur inefficace. Cet événement peut avoir conduit à la réduction du champ coercitif à une température suffisamment basse dans l'échantillon x = 0.1 en supposant que les grains sont fortement couplés en échange. / This study proposes the idea of the so-called tetragonal ferrite magnets by rendering the crystal symmetry of the cubic spinel ferrites to enhance the magnetic anisotropy (and hence, enhance the coercivity). To realize this idea, we synthesized tetragonally distorted (Cu,Co)-ferrite particles and systematically characterized the magnetic properties accordingly with their lattice distortions. The intrinsic and extrinsic factors contributing to coercivity were investigated. To elucidate the magnetic anisotropy, we demonstrated a physical coupling model of the Jahn-Teller (JT) effect and the magnetoelastic (ME) effect within the phenomenological theory. Then, we performed coercivity analysis within two general models of coercivity to clarify the microstructure parameters contributing to the magnetization reversal mechanism. From the magnetoelastic model analysis, we demonstrated the linear expression of the magnetic anisotropy using the tetragonal parameter obtained from the JT distortion. The magnetoelastic coefficient values for Cu (B1Cu = 2 MJ/m3) and Co (B1Co = 40 MJ/m3) deduced from the experimental curve were agreeable with the value calculated for bulk copper ferrite (B1Cu bulk= 4 MJ/m3) and cobalt ferrite (B1Co bulk= 55 MJ/m3). The results suggests that the source of magnetic anisotropy can be attributed to the coupling of the JT distortion with the magnetoelastic effect of Co. Instead of an indefinite increase with x, the magnetic anisotropy Ku tends to reach a saturation value due to the competition between the magnetoelastic effect of Co and the JT effect of Cu. Between the tetragonal x = 0.1 and the cubic x = 0.2 samples, the intrinsic magnetic anisotropy constant Ku values do not vary as significantly compared to the difference in the coercivity and the anisotropy fields. The reduction of anisotropy fields above x = 0.1 then can be attributed to the increase in the spontaneous magnetization.The coercivity analysis within the micromagnetic model revealed significant contribution to the coercivity by the microstructure and the local demagnetizing effect. The microstructure parameter αMM = 0.25 obtained was a classical value in the micromagnetic analysis, suggesting the departure of anisotropy field with this reduction factor. The effective local demagnetizing factor NeffMM of about 1.4 obtained were rather large suggesting a significant demagnetizing effect. Within the global model (GM) analysis, the values of NeffGM obtained were -0.38 for the x = 0.1 sample. The negative value suggests the presence of an exchange interaction acting effectively in opposition to the dipolar interaction. Below 100 K, discrepancy in the GM suggests the idea of a local heating event following the thermal activation due to the change in Zeeman energy and ineffective heat dissipation. This event may have led to the reduction of coercive field at sufficiently low temperature in the x = 0.1 sample assuming the grains are strongly exchange-coupled.
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