A carbon/silica/carbon-fiber composite (CSCFC) was fabricated from agricultural waste of rice husk (RH) and industrial waste of carbon fiber (CF) ends. The powder-state RH mixed with chopped CF ends (0 to 30mass%) was molded into a disk by means of hot-pressing in an inert condition without using any binders, and then heated to 500 and 1000°C. Mechanical properties of CSCFC and the role of CF addition level on them were evaluated. The CSCFC added with 10 mass% of CF and heated to 500°C displayed the highest compressive strength of 61 MPa. It was also shown that higher heat treatment temperature reduced the compressivestrength. The CF restricted a uniform thermal shrinkage of the matrix material derived fromRH, causing cracks and eventually reducing the compressive strength. The friction coefficient atthe CSCFC surface was evaluated under a contact with a SUS304 ball. The CSCFC added with CF at 20mass% and heated to 1000°C displayed the lowest kinetic friction coefficient of 0.12. The CSCFC produced from waste materials of RH and CF ends were shown to have high compressive strength and low friction coefficient even if they were fabricated without using any binders.
Experimental study was conducted to heat gases using an arc driven by external magnetic field. DC arc was produced between a tungsten rod cathode and a cylindrical anode. DC electric current through a solenoid coil around a heating chamber induced the axial magnetic field which interacted with the arc. The anode root of the arc rotated on the cylindrical anode by the electromagnetic force. Experimental observation revealed that the movement of the rotating arc was unstable and its rotating frequency was uncertain. The arc voltage increased with the increase of the magnetic field strength. Gas temperature was measured by a specially designed calorimeter. The gas temperature increased with the increase of the magnetic field strength. Heating efficiency of the arc was nearly 40 [%]
Generation properties of second harmonic component for the infinite amplitude ultrasonic wave originated from the contact between solids by CAN (contact acoustic non-linearity) are examined.Effect of generation for the harmonic component for area, pressure and surface roughness of the solid contact are systematically experimented using glass blocks to clarify the properties of CAN. From the experiments using large amplitude 1 MHz ultrasonic burst sine wave, the second harmonic component of 2 MHz generated by CAN which depends on the true contact area of the solid contact is clarified. Surface roughness of solid contact which becomes important factor for generating CAN is also examined. Thick adhesive layer introduced between solids surface is effective to reduce the generation of CAN is newly suggested.
An immobilization of serum albumin and warfarin-serum albumin interaction were studied by means of surface plasmon resonance measurement. Physical and chemical immobilizations of human serum albumin (HSA) and bovine serum albumin (BSA) onto sensor surface were examined to resolve how protein immobilization methods on sensor surface affect for protein-drug molecule interaction measurement. Spontaneous adsorptions of HSA and BSA onto gold surface were utilized for physical immobilization. Adsorptions of BSA and HSA were described by Langmuir-type adsorption, and the adsorptivity of BSA were higher than the one of HSA. 11-mercaptoundecanoic acid monolayer was employed as anchor for the chemical immobilization of HSA molecule. Chemically and physically immobilized HSA-warfarin interaction was examined and compared. Binding amount of warfarin to chemically immobilized HSA was larger than physically immobilized one. It is suggested that the chemical immobilization of protein molecule onto sensor surface is preferred for protein-drug molecule interaction measurements.
In this work, we selected potassium hydroxide (KOH) as a chemical agent for acetic acid (CH3COOH) removal and loaded KOH on activated carbon. We considered the influence of KOH-loading on the specific surface area, the pore volume and the removal ability of CHsh3COOH in order to use KOH loaded activated carbon as air purifier filters. The KOH-loading of activated carbon proportionally increases with increasing the concentration of KOH aqueous solution, while the specific surface area and the pore volume show decreasing trends with the increase of KOH-loading. We find that KOH is easily loaded in the micropores smaller than 1nm and loaded on the surface region of activated carbon as well as in the larger pores with increasing KOH-loading. The deodorization performance of KOH loaded activated carbon as purifier filters was also evaluated using Tobacco. Activated carbon with the higher KOH-loading shows a shorter removal time of CH3COOH and has an ability of treating the larger number of tobacco, while the rate of increase of the number of tobacco which activated carbon can treat is small compared with that of KOH-loading increase.
The sliding properties of the composite fabricated from agriculture waste of rice husk (RH) without using any binders was investigated. The slab-shaped composites heated to 300, 500, 800, 1000, and 1200°C were prepared, and their shore hardness and sliding properties were evaluated. The composites heated to 1000°C displayed the highest Shore hardness of 99.7 HS. Sliding properties of the composites such as kinetic friction coefficient and specific wear rate were evaluated under the contact with a SUS304. The composites heated to 1000°C displayed low kinetic friction coefficient and specific wear rate, which were respectively 0.08 and 1.7×10-9 mm2/N. The composites were subjected to thermal shrinkage of the matrix material derived from lignocellulosic parts in RH. The thermal shrinkage led to a densification of the composite, improving the sliding properties.