Divertors are required to remove the impurities such as helium ashes in a magnetic conferment-type fusion reactor. Detached plasma is one of the major systems to suppress the heat load from a core plasma. The electron temperature and density have been measured with the linear divertor simulation device TPD-sheet IV. To model the ion density, a zero-dimensional model has been developed for solving the system of rate balance equations. We have confirmed the characteristic of ion density on gas pressure with rate equation. The molecular ion density decreases with the gas pressure, therefore molecular recombination reaction may contribute to detached plasma generation.
Flexible and light-weight perovskite solar cells (PSCs) have been considered due to the expectation of low production cost and wide application ranges. Low temperature processes are required in the fabrication of flexible perovskite solar cells because flexible substrates cannot resist process temperatures over 150 ºC. An electron transport layer (ETL) is commonly titanium-oxide (TiO2) formed by high temperature sintering (˃400ºC). The formation of ETM is crucial for flexible PSCs in order to complete the entire low-temperature process. Here, we have employed our original single crystalline TiO2 nanoparticles with high purity of brookite phase (BK TiO2 NPs), and could form TiO2 ETLs below 150 ºC. We succeeded to fabricate flexible PSCs on polyethylene naphthalate (PEN) substrates with the power conversion efficiency of 13.08% (in reverse scan). The present work provides us a good finding to realize the low-cost flexible PSCs in the future.
Photovoltaic (PV) Generation system is one of the easiest renewable energy systems to generate either small amounts of energy for usage in households or for large amounts as utilized in fields. Although PV generation system does not burn fuel for power generation, some problems exist regarding heat. One of these problems is called Hotspots. A Hotspot is an increase in the cell`s heat in certain conditions and positions. In some cases, the heat can even ignite a fire. In this study, we propose a new method to detect this hotspot phenomenon at an early stage. The proposed method utilizes Artificial Intelligence (AI) as the main detection system. In fact, we were able to detect the hotspot with an accuracy of 82.25% using only two parameters, string current and string voltage. This system is a secondary system to be used in conjunction with the main control system. The output will be a flag sent to the main controlling system. Designing this system as secondary one, makes it easier to apply in already constructed PV fields. The findings illustrated the detection of hotspots with an accuracy rate of 82.25% using only two parameters, namely string current and string voltage. Thus the findings from this study provides a basis for the future development of a system which provides an overall evaluation for solar panels including hotspots and degradation.
In this study, similarity of behavior between the recombination plasma and aurora-curl have been investigated by using a magnetized sheet plasma. The magnetized sheet plasma is generated by a liner plasma device (TPDsheet-U). Plasma flow, and plasma parameters are measured by a high-speed camera, a mach probe and cylindrical probe. As the results, the plasma is rotating in the clockwise around the magnetic line and this rotation is derived from E×B drift like curl.
In ancient Japan, steelmaking was practiced nationwide, but in the Middle Ages, steelmaking was carried out only in areas around Okuizumo, and steelmaking elsewhere declined. Kamakura was one of the areas that declined, but we reproduced ancient steelmaking using Kamakura iron sand as a raw material, and searched for a method to estimate the place of production of the iron that was used as the raw material for ancient generated iron.
A novel inverter without the chopper for the field circuit was proposed for hybrid-excitation-type synchronous machines. In this inverter, a switch is connected between the neutral point of the armature windings of the machine and the field circuit. The field flux in the machine is increased when the switch is on, and is unchanged when off. By using a circuit simulator, we have clarified that two phase modulation can be used to the inverter when the switch is off.
In this study, we focus on the tactile illusion of stiffness feeling by surface roughness. Human factors on tactile illusion is analyzed from the viewpoint of the fingertip stiffness and finger motion. Specifically, five types of samples with different surface roughness are fabricated. Sensory evaluations for the stiffness feeling and the roughness feeling are conducted. Also, the fingertip stiffness and fingertip force when the panelists touch the samples are measured. As a result, it is confirmed that tactile illusion on stiffness due to surface roughness occurs to some panelists. And it is shown that the tactile illusion is less likely to occur in panelists with hard fingertips. Moreover, the panelists with tactile illusion are classified into two groups based on the relationship between the surface roughness and the stiffness feeling. And it is suggested that each group has characteristics in the relationship between the touch motion and fingertip stiffness.