1,633 research outputs found

    Spin-Orbit Interaction Effects in the Electronic Structure of B20-type CoSi: First-Principles Density Functional Study

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    We have performed fully relativistic first-principles density functional calculations for non-magnetic B20-type CoSi. The spin-orbit interaction has crucial effects on the electronic structures of a chiral crystal. The calculated band structure around the Fermi energy shows Bloch vector kk-linear dispersion expressed by a realreal-spinspin Weyl Hamiltonian, i.e., a mass-less Dirac Hamiltonian. We found the hedgehog-like spin texture in Bloch k\boldsymbol k-vector space (momentum space) on the isoenergy surface around the Γ\Gamma point. The Fermi velocity for kk-linear dispersion is about 0.22vFgv^g_F, where vFgv^g_F is the Fermi velocity of graphene.Comment: 6 pages, SCES 2013, accepted for publication in JPS Conf. Pro

    Portfolio Selection Problems with Normal Mixture Distributions Including Fuzziness

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    In this paper, several portfolio selection problems with normal mixture distributions including fuzziness are proposed. Until now, many researchers have proposed portfolio models based on the stochastic approach, and there are some models considering both random and ambiguous conditions, particularly using fuzzy random or random fuzzy variables. However, the model including normal mixture distributions with fuzzy numbers has not been proposed yet. Our proposed problems are not well-defined problems due to randomness and fuzziness. Therefore, setting some criterions and introducing chance constrains, main problems are transformed into deterministic programming problems. Finally, we construct a solution method to obtain a global optimal solution of the problem

    Aging and Degradation Behavior Elucidated by Viscoelasticity Aiming Protection of Smart City Facilities

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    Polymer coatings play a crucially important role in protecting smart city facilities against the harsh factors of outdoor environments. Recent increased awareness of eco‐friendliness has led to the use of waterborne organic coatings. Research into the bulk material properties of these coatings is necessary in order to understand their degradation process in the field. The present work focuses attention on a unique rheological property, which has both elastic and viscous characteristics, as a means of assessing the stability of the coating. The viscoelastic property determines whether it presents solid‐like or liquid‐like response from the comparison of relative strengths of the relaxation time (τ) and operating time (t). In the process of degradation, both the storage (E′) and loss modulus (E″), which represent the elastic and viscous components, respectively, decrease accordingly, reflecting the deterioration of coating. The majority of the water molecules absorbed in a coating are strongly bound to the polymer network through hydrogen bonds with polar functional groups, which destroys intermolecular bonding between macromolecules and reduces the bulk materials’ ability to diffuse stress concentrations and thereby lowers a coating’s overall strength

    A model for the infrared dust emission from forming galaxies

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    In the early epoch of galaxy evolution, dust is only supplied by supernovae (SNe). With the aid of a new physical model of dust production by SNe developed by Nozawa et al. (2003) (N03), we constructed a model of dust emission from forming galaxies on the basis of the theoretical framework of Takeuchi et al. (2003) (T03). N03 showed that the produced dust species depends strongly on the mixing within SNe. We treated both unmixed and mixed cases and calculated the infrared (IR) spectral energy distribution (SED) of forming galaxies for both cases. Our model SED is less luminous than the SED of T03 model by a factor of 2-3. The difference is due to our improved treatment of UV photon absorption cross section, as well as different grain size and species newly adopted in this work. The SED for the unmixed case is found to have an enhanced near to mid-IR (N-MIR) continuum radiation in its early phase of the evolution (age < 10^{7.25} yr) compared with that for the mixed case. The strong N--MIR continuum is due to the emission from Si grains, which only exist in the species of the unmixed dust production. We also calculated the IR extinction curves for forming galaxies. Then we calculated the SED of a local starbursting dwarf galaxy SBS 0335-052. Our present model SED naturally reproduced the strong N--MIR continuum and the lack of cold FIR emission of SBS 0335-052. We found that only the SED of unmixed case can reproduce the NIR continuum of this galaxy. We then made a prediction for the SED of another typical star-forming dwarf, I Zw 18. We also presented the evolution of the SED of LBGs. Finally, we discussed the possibility of observing forming galaxies at z > 5.Comment: MNRAS, in press. 18 pages, 15 figures. Abstract abridge

    Long-term oxygen therapy in Japan: history, present status, and current problems

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    Historically, the progress of long term-oxygen therapy (LTOT) in Japan has been characterized by collaboration among academicgroups, policy makers, and industrial companies. The public health insurance program has covered the cost of LTOT since 1985.Thomas Petty’s group in Denver enthusiastically carried out the public implementation of LTOT and conveyed the concept of pulmonaryrehabilitation for the processing with LTOT. Although the target diseases of LTOT in Japan tended to be chronic obstructivepulmonary disease or sequelae of primary lung tuberculosis, it was soon applied for cardiac diseases as well as other pulmonarydiseases. Together with increasing medical costs for geriatric patients, the political conversion from hospital based care ofa traditional style to home care system has been performed, with two background reasons: the improvement of quality of life ofpatients and the reduction of the medical expense. Presently, LTOT plays a pivotal role in the successful implementation of homerespiratory care for elderly patients. In addition, this promotes comprehensive pulmonary rehabilitation, a team approach, andclose liaisons between primary care and hospitals. Currently, the total number of patients using LTOT exceeds 150,000. In Japan,LTOT resulted in an advancement in the medical care as well as in administrative decision to introduce it as a nationwide systemafter analyzing the results of opinion polls of patients with respiratory failure. However, the recent great earthquake in East Japanrevealed that many unresolved problems remain for these patients, and these issues are of great concern.Historically, the progress of long term-oxygen therapy (LTOT) in Japan has been characterized by collaboration among academicgroups, policy makers, and industrial companies. The public health insurance program has covered the cost of LTOT since 1985.Thomas Petty’s group in Denver enthusiastically carried out the public implementation of LTOT and conveyed the concept of pulmonaryrehabilitation for the processing with LTOT. Although the target diseases of LTOT in Japan tended to be chronic obstructivepulmonary disease or sequelae of primary lung tuberculosis, it was soon applied for cardiac diseases as well as other pulmonarydiseases. Together with increasing medical costs for geriatric patients, the political conversion from hospital based care ofa traditional style to home care system has been performed, with two background reasons: the improvement of quality of life ofpatients and the reduction of the medical expense. Presently, LTOT plays a pivotal role in the successful implementation of homerespiratory care for elderly patients. In addition, this promotes comprehensive pulmonary rehabilitation, a team approach, andclose liaisons between primary care and hospitals. Currently, the total number of patients using LTOT exceeds 150,000. In Japan,LTOT resulted in an advancement in the medical care as well as in administrative decision to introduce it as a nationwide systemafter analyzing the results of opinion polls of patients with respiratory failure. However, the recent great earthquake in East Japanrevealed that many unresolved problems remain for these patients, and these issues are of great concern
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