We generated pulses of electromagnetic radiation in the terahertz (THz) frequency range by optical excitation of Co2Fe0.4Mn0.6Si (CFMS)/normal-metal (NM) bilayer structures. The CFMS is a Heusler alloy showing a band ...
详细信息
We generated pulses of electromagnetic radiation in the terahertz (THz) frequency range by optical excitation of Co2Fe0.4Mn0.6Si (CFMS)/normal-metal (NM) bilayer structures. The CFMS is a Heusler alloy showing a band gap in one spin channel and is therefore a half metal. We compared the THz emission efficiency in a systematic manner for four different CFMS/NM bilayers, where NM was either Pt, Ta, Cr, or Al. Our measurements show that the THz intensity is highest for a Pt capping. We also demonstrate the tunability of the THz amplitude by varying the magnetic field for all four bilayers. We attribute the THz generation to the inverse spin Hall effect. In order to investigate the role of the interface in THz generation, we measured the spin mixing conductance for each CFMS/NM bilayer using a ferromagnetic resonance method. We found that the spin-orbit coupling cannot completely describe the THz generation in the bilayers and that the spin transmission efficiency of the CFMS/NM interface and the spin diffusion length, as well as the oxidation of the NM layer, play crucial roles in the THz emission process.
In the world it is difficult to design in terms of average dimension. For this reason anthropometric plays a great rule in the world in design of products. In Ethiopia T-72 tanks are the most important weapons that gi...
In the world it is difficult to design in terms of average dimension. For this reason anthropometric plays a great rule in the world in design of products. In Ethiopia T-72 tanks are the most important weapons that give a strong support to the ground force in the battle field. So the question of the correct ergonomically design and analysis of the driver seat especially in terms of comfort is mandatory so due to this fact, study anthropometric of driver's seat is very important. It is necessary to define the drivers’ space and seat dimensions by considering the size of the average people according to their body dimensions. The basic questions for this research are (i) To what extent the soviet fabricated tank driver's seat is comfortable to Ethiopia army, (ii) Is there significant different between the body size dimension of soviet and Ethiopian army, and (iii) The Ethiopian military derivers have awareness of the comfort. The main goal of this paper is to conduct descriptive survey on an ergonomics assessment of driver's seat of T72 tank. Following sitting height, popliteal height, sitting to shoulder height, shoulder breadth, buttocks to popliteal length, and hip breadth seated anthropometric dimensions were measured of 45 subjects / respondents (35 males, 10 females) randomly selected from the field study. Mean, standard deviation, and T-test were calculated based on anthropometric data of subjects. Results revealed suggest a mismatch among the dimensions of current T-72 Russian fabricated tank motive force seat and the anthropometric dimensions of military staffs. This recommends that anthropometric information of the Ethiopian army tank drivers changed into not working in the design and manufacturing of the seats. This research is may be cautioned that tank driving force seat of T-72 tank and tank drivers anthropometric measurements are at variance. Therefore, the paper presents anthropometric statistics that may be utilized by the Russian manufacturers of tank
We compare magnetic reversal of nanostructured circular magnetic dots of different sizes. This comparison is based on superconducting quantum interference device (SQUID) magnetometry, neutron scattering, Monte Carlo s...
We compare magnetic reversal of nanostructured circular magnetic dots of different sizes. This comparison is based on superconducting quantum interference device (SQUID) magnetometry, neutron scattering, Monte Carlo simulation, and analytical calculations and is quantified using a parameter which characterizes the variation in the hysteresis curve width. Below a critical dot diameter, the magnetic reversal occurs by coherent rotation and above that diameter, the reversal occurs by formation of a magnetic vortex. The vortex-core diameter is controlled by competing magnetic energy contributions. For 20-nm-thick Fe dots, the values of the critical diameter (58–60 nm) and the vortex core (16–19 nm) are in very good agreement between the different experimental and theoretical methods: neutron scattering, SQUID magnetometry, Monte Carlo simulations, and analytical calculations.
Correction for 'Structure, function, self-assembly, and applications of bottlebrush copolymers' by Rafael Verduzco et al., Chem. Soc. Rev., 2015, 44, 2405-2420.
Correction for 'Structure, function, self-assembly, and applications of bottlebrush copolymers' by Rafael Verduzco et al., Chem. Soc. Rev., 2015, 44, 2405-2420.
Organic‐inorganic hybrid two‐dimensional (2D) perovskites ( n ≤5) have recently attracted significant attention because of their promising stability and optoelectronic properties. Normally, 2D perovskites contain a...
详细信息
Organic‐inorganic hybrid two‐dimensional (2D) perovskites ( n ≤5) have recently attracted significant attention because of their promising stability and optoelectronic properties. Normally, 2D perovskites contain a monocation [e.g., methylammonium (MA + ) or formamidinium (FA + )]. Reported here for the first time is the fabrication of 2D perovskites ( n =5) with mixed cations of MA + , FA + , and cesium (Cs + ). The use of these triple cations leads to the formation of a smooth, compact surface morphology with larger grain size and fewer grain boundaries compared to the conventional MA‐based counterpart. The resulting perovskite also exhibits longer carrier lifetime and higher conductivity in triple cation 2D perovskite solar cells (PSCs). The power conversion efficiency (PCE) of 2D PSCs with triple cations was enhanced by more than 80 % (from 7.80 to 14.23 %) compared to PSCs fabricated with a monocation. The PCE is also higher than that of PSCs based on binary cation (MA + ‐FA + or MA + ‐Cs + ) 2D structures.
Machining is a globally used manufacturing technology where some part of metal is reduced from bulk workpiece in the chip form. In this thesis work, explores the science of new techniques of machining by two single po...
Machining is a globally used manufacturing technology where some part of metal is reduced from bulk workpiece in the chip form. In this thesis work, explores the science of new techniques of machining by two single point cutting tools simultaneous engaged with workpiece material to increase efficiency of the turning operation. In order to implement double tool turning process a normal lathe machine setup was altered. In turning operation, the process factors which affect machined surface quality of component are cutting speed, feed, and depth of cut. Investigation was trailed out to the improvements of productivity by this new machining technique under the influence of metal cutting factors on cutting temperature, tool wear. The morphology of chips and machining time were also studied. A comprehensive test was examined by utilising single and double tool turning process on mild steel work material. The analytically predicted metal cutting temperatures, cutting tool wear, machining time were investigated in detail. For the selected metal cutting conditions, it was recorded that the machining time reduced by 25% surprisingly which the production with this time ranges increased. Tool wear area measured by optical Profilometer shows that total wear zone 813.11mm2 for single tool turning while it was reduced to 45.57 mm2 for double tool turning.
暂无评论