7,434 research outputs found
Stratified dispersive model for material characterization using terahertz time-domain spectroscopy
We propose a novel THz material analysis approach which provides highly
accurate material parameters and can be used for industrial quality control.
The method treats the inspected material within its environment locally as a
stratified system and describes the light-matter interaction of each layer in a
realistic way. The approach is illustrated in the time-domain and
frequency-domain for two potential fields of implementation of THz technology:
quality control of (coated) paper sheets and car paint multilayers, both
measured in humid air.Comment: 4 pages, 4 figure
Mg-Ni-H films as selective coatings: tunable reflectance by layered hydrogenation
Unlike other switchable mirrors, Mg2NiHx films show large changes in
reflection that yield very low reflectance (high absorptance) at different
hydrogen contents, far before reaching the semiconducting state. The resulting
reflectance patterns are of interference origin, due to a self-organized
layered hydrogenation mechanism that starts at the substrate interface, and can
therefore be tuned by varying the film thickness. This tunability, together
with the high absorptance contrast observed between the solar and the thermal
energies, strongly suggests the use of these films in smart coatings for solar
applications.Comment: Three two-column pages with 3 figures embedded; RevTE
Oxygen isotope effect and phase separation in the optical conductivity of (LaPr)CaMnO thin films
The optical conductivities of films of
(LaPr)CaMnO with different oxygen isotopes
(O and O) have been determined in the spectral range from 0.3 to
4.3 eV using a combination of transmission in the mid-infrared and ellipsometry
from the near-infrared to ultra-violet regions. We have found that the isotope
exchange strongly affects the optical response in the ferromagnetic phase in a
broad frequency range, in contrast to the almost isotope-independent optical
conductivity above . The substitution by O strongly suppresses the
Drude response and a mid-infrared peak while enhancing the conductivity peak at
1.5 eV. A qualitative explanation can be given in terms of the phase separation
present in these materials. Moreover, the optical response is similar to the
one extracted from measurements in polished samples and other thin films, which
signals to the importance of internal strain.Comment: 11 pages, 11 figures, to appear in PR
Surface state charge dynamics of a high-mobility three dimensional topological insulator
We present a magneto-optical study of the three-dimensional topological
insulator, strained HgTe using a technique which capitalizes on advantages of
time-domain spectroscopy to amplify the signal from the surface states. This
measurement delivers valuable and precise information regarding the surface
state dispersion within <1 meV of the Fermi level. The technique is highly
suitable for the pursuit of the topological magnetoelectric effect and axion
electrodynamics.Comment: Published version, online Sept 23, 201
Sports-related injuries in primary health care
Introduction. Sports activities play an important role in todayâs society. However, as more people become involved in these activities, the number of sports-related injuries also increases. In the Netherlands, 3.5 million sports injuries occur annually. Twenty per cent of these injuries are first seen by a GP. Little is known about the epidemiology of these injuries in general practice. This study has been conducted to determine the incidence and prevalence of sports-related injuries in general practice and to provide information about the nature and treatment of these injuries
Pengembangan Media Pembelajaran Berbasis Komputer pada Mata Kuliah Pastry di Jurusan Ilmu Kesejahteraan Keluarga Fakultas Pariwisata dan Perhotelan Universitas Negeri Padang
The aims of this study was to develop a computer-based learning media is valid and practical course on pastry in the ca of IKK FPP UNP. This study uses Research And Development (R & D) is the method used to produce a specific product and test the feasibility of the product. Products produced in the form of computer-based learning media in the Department of IKK FPP UNP. Data collection techniques in this study conducted using questionnaires given to lecturers caterers and questionnaire responses of students to the media developed and analyzed using analysis deskripstif which includes analysis of the validity, and analysis of the practicalities. The results of this study indicate that the validity of computer-based learning media on valid category (0.89). While the practicalities of the test, the lecturer / practitioner gives very practical category (92.7%) and students leave with a very practical category (88.7%). Based on these findings it can be concluded that computer-based learning media is valid and practical to be used as a medium of learning in the subject of Pastry
Static stretching of the hamstring muscle for injury prevention in football codes: a systematic review
Purpose: Hamstring injuries are common among football players. There is still disagreement regarding prevention. The aim of this review is to determine whether static stretching reduces hamstring injuries in football codes.
Methods: A systematic literature search was conducted on the online databases PubMed, PEDro, Cochrane, Web of Science, Bisp and Clinical Trial register. Study results were presented descriptively and the quality of the studies assessed were based on Cochraneâs ârisk of biasâ tool.
Results: The review identified 35 studies, including four analysis studies. These studies show deficiencies in the quality of study designs.
Conclusion: The study protocols are varied in terms of the length of intervention and follow-up. No RCT studies are available, however, RCT studies should be conducted in the near future
Synthesis of glycosylated 1-deoxynojirimycins starting from natural and synthetic disaccharides
Iminosugars are an important class of natural products and have been subject to extensive studies in organic synthesis, bioorganic chemistry and medicinal chemistry, yet only a limited number of these studies are on glycosylated iminosugars. Here, a general route of synthesis is presented towards glycosylated 1âdeoxynojirimycin derivatives based on the oxidationâreductive amination protocol that in the past has also been shown to be a versatile route towards 1âdeoxynojirimycin. The strategy can be applied on commercial disaccharides, as shown in four examples, as well as on disaccharides that are not commercially available and are synthesized for this purpose, as shown by a fifth example.Medical BiochemistryBio-organic Synthesi
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