Capsaicin was successfully intercalated into layered double hydroxide (LDH) by coprecipitation and ion-exchange method. The intercalation of capsaicin was confirmed by XRD, FT-IR, and elemental analysis. It was confirmed by XRD that the basal spacing of the host LDH increased from 0.88 to 1.50 nm after the intercalation of capsaicin into the LDH. Capsaicin-intercalated LDH (LDH-Cap) powder was readily dispersed in polymer materials such as silicone rubber, acrylic lacquer, epoxy lacquer, and polystyrene to produce composites filled with LDH-Cap. It was found that the amount of released capsaicin from the composite materials was controlled by intercalation into LDH. The composites possess bio-repellent properties against acorn barnacle and protective ability against rat gnawing damage.
Recently, the demand for a low noise environment in vessels has increased. Cabin noise consists of several noise sources. In most cases, the primary source of noise is the engine. Generally, the resilient mount system is effective in reducing Structure-borne Noise, especially in middle and high speed engines. This paper presents collaborative strategies by a ship builder and an engine maker to reduce Cabin noise in a tourist ship with some applications.
The electrostatic precipitator (ESP) with heat exchanger was developed to reduce particles and SO2 in a diesel engines. The influence of gas cooling on the particle and SO2 concentrations was investigated using a 400 cc diesel engine. The particle concentrations were measured with a scanning mobility particle sizer (SMPS) and a low volume air sampler. Soluble Organic Fraction (SOF) and SO42-, which make up the composition of the particle, were also evaluated using a soxhlet extractor and an ion chromatography. SO2 concentration was measured with a UV fluorescence SO2 monitor. The results show that the number and the volume concentration of particles increased due to generated SOF and sulfuric acid particles by gas cooling. It was also indicated that SO2 concentration in the gas was reduced due to absorption into condensed water. Although the particle concentration increased, ESP showed a high particle collection efficiency.
Large implementation of fully electric ship (FES) on next generation vessels with advanced electric propulsion drive and high-power electronic modules will increase high thermal requirements onboard ship. Traditional cooling processes by natural and forced air-cooling have limitations on the capability to handle anticipated heat dissipation requirements of high-power electronics. Two-phase closed loop thermosyphon (CLT) as one of liquid cooling technologies for power electronics is considered to be a compact thermal management device due to its flexibility in size and cooling capacity range, and it offers significant cost and reliability over systems that require pumps. The greatest benefit of CLT device is its simple composition and reliability for transporting heat with a small decrease in temperature, and therefore one considers it as a promising heat transfer device onboard ships and is suited for robust shipboard cooling requirements. In this study, a high heat flux CLT for cooling an IGBT module which comprises one of high-power electronics modules in the inverter of electric propulsion system was developed and examined up to a range of over 4.0 MW/m2.
Hydrogen is attracting attention as an alternative energy source to fossil fuels and nuclear power. Liquid hydrogen (LH2) with a density of about 800 times that of gaseous hydrogen is suitable for transportation and storage. The precise measurement of liquid level is important for liquid hydrogen management. The authors have developed an external-heating type superconducting MgB2 level sensor and previously reported the thermal response of an 800-mm-long MgB2 level sensor. However, the effect of sensor length on thermal response is not clear. To clarify the effect of sensor length, the authors examined the thermal response of a 200-mm-long MgB2 level sensor as parameters of heater input and liquid level. It was found that the thermal response of the MgB2 level sensor was independent of both parameters regardless of the sensor length. Moreover, the thermal response of the MgB2 level sensor was excellent at a heater input of 6 W and above.