We increased the light-extraction efficiency (LEE) of AlGaN-based deep-ultraviolet light-emitting diodes (DUV LEDs) by introducing a highly reflective photonic crystal (HR-PhC) into the surface of the p-AlGaN contact layer, thereby achieving a high external quantum efficiency (EQE). A low-damage HR-PhC with a lattice period of approximately 250 nm was fabricated using nanoimprinting and dry etching. A reflective Ni/Mg p-type electrode was deposited on the HR-PhC layer using a tilted-evaporation method. The EQE of a conventional DUV LED with emission around 283 nm was increased from 4.8 to 10% by introducing the HR-PhC and the reflective Ni/Mg electrode. A simple estimation of the effective reflectance of the HR-PhC p-AlGaN contact layer with the Ni/Mg electrode indicated a value exceeding 90%.
We report the observation of magnetoresistance originating from Rashba spin-orbit coupling (SOC) in a metallic heterostructure: the Rashba-Edelstein (RE) magnetoresistance. We show that the simultaneous action of the direct and inverse RE effects in a Bi/Ag/CoFeB trilayer couples current-induced spin accumulation to the electric resistance. The electric resistance changes with the magnetic-field angle, reminiscent of the spin Hall magnetoresistance, despite the fact that bulk SOC is not responsible for the magnetoresistance. We further found that, even when the magnetization is saturated, the resistance increases with increasing the magnetic-field strength, which is attributed to the Hanle magnetoresistance in this system.
Cholinergic synaptic vesicles from the electric organ of Torpedo marmorata have been purified to a constant composition and a higher transmitter content than previously reported. By optimising the extraction conditions and using a two‐step purification on discontinuous and continuous sucrose density gradients, 10‐fold higher acetylcholine and ATP values per weight of protein were obtained. The purity of the vesicle preparation was confirmed by electronmicroscopy, absence of marker enzymes, behaviour in density gradient centrifugation, as well as by a specific and reproducible protein composition.
Vesicles contain 6.9 μmol acetylcholine and 1.0 μmol ATP per mg protein. The lipid/protein ratio of 3.5 (w/w) indicates a lipid‐rich membrane. The value suggests the absence of a proteinaceous core.
Upon dodecylsulphate gel electrophoresis a distinct protein pattern is obtained with components ranging from 20000 to 160000 in molecular weight. Vesiculin, reported earlier to be a low molecular‐weight vesicle protein, is not detected.
One of the major bands comigrates with muscle actin from the same animal. Further characterisation of this protein by two‐dimensional gel electrophoresis suggested that it is an actin‐like polypeptide. Evidence for a specific association of this actin‐like protein with vesicles and its possible involvement in the neurosecretory process is discussed.
Quantitative relations between discomfort glare evaluation and photometric quantities such as illuminance at the observer's eye, average luminance of the source area, average luminance of the effective area and effective glare luminance for white LED sources having a variety of spatial luminance distributions have been investigated. Effective glare luminance, which is the sum of luminances in the luminaire area divided by the effective area, explains the scaling results of all sources in the same way. In addition, a new equation modified from the Commission Internationale de l'É clairage Unified Glare Rating formula using the effective glare luminance showed a strong correlation with the scaling results. It is thus suggested that effective glare luminance is a useful index of discomfort glare for light sources having different spatial luminance distributions.
The ability to monitor subtle changes in vital and arterial signals using flexible devices attached to the human skin can be valuable for the detection of various health conditions such as cardiovascular disease. Conventional Si device technologies are being utilised in traditional clinical systems; however, its fabrication is not easy owing to the difficulties in adapting to conventional processes. Here, we present the development of a fully printed, wearable, ferroelectric-polymer vital sensor for monitoring the human pulse wave/rate on the skin. This vital sensor is compact, thin, sufficiently flexible, and conforms to the skin while providing high pressure sensitivity, fast response time, superior operational stability, and excellent mechanical fatigue properties. Moreover, the vital sensor is connected to a communication amplifier circuit for monitoring the pulse waves with a wireless sensing system. This sensor system can realise the development of new healthcare devices for wearable sensor applications.
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