Vortex tubes are simple tubes that can separate hot and cold air from compressed air without any internal device configuration and are used in many industries. If the vortex tube with these advantages is applied to an air conditioning system, it will be free from the use of refrigerant. In this study, basic study on discharge flow rate and temperature separation characteristics was carried out by varying the number of generator nozzle hole in various shapes of the vortex tube according to the inlet pressure of the vortex tube. Experimental results show that as the number of nozzles increases, the discharge flow rate tends to decrease and the temperature separation characteristics were excellent in the number of nozzles 6~7.

The CO2 separation membranes based on a graft copolymer consisting of hydrophobic poly(ethylene-alt-maleic anhydride) (PEMA) backbone and hydrophilic poly(propylene glycol) PPG side chains were fabricated by a facile one-pot process. The reaction between O-(2-aminopropyl)-O’-(2-methoxyethyl) polypropylene glycol (AMPPG) and PEMA was conducted in butanol at room-temperature. Without any post-treatment, the as-synthesized PEMA-g-PPG solution could be directly coated onto a microporous polysulfone support to fabricate thin-film composite membranes. The PEMA-g-PPG membrane exhibited high selectivity (82.6 for CO2/N2 and 26.8 for CO2/CH4) and good CO2 permeability (99.1 Barrer), which is a close value to the upper boundary limit (2008). The PEMA-g-PPG membrane could be commercially feasible owing to simple, inexpensive and scalable process.

Graphene oxide (GO), a highly oxidized graphene sheet, is a distinguished 2-D nanosheet. GO membranes exhibit good CO2 separation properties due to its various polar functional groups with oxygen resulting in high CO2 sorption properties. Recently, GO nanosheets have been incorporated into polymer membranes expecting the synergistic effect. There is, however, little research on GO as a crosslinker even though it has high potential due to available functional groups for further reaction. Here, we prepared GO/polymer membranes by crosslinking reactions between polar groups of GO and bi-functional polymer matrix at different temperatures. Optimum crosslinking condition was found by analyzing gas transport, chemical properties of samples. Degree of crosslinking in GO/polymer nanocomposites affected gas transport behavior.

The diesel engine uses the intercooler for cooling of charging air by the turbo-charger. But the cooling efficiency of the intercooler which is influenced by the vehicle speed is decreased in low vehicle speed. If the vortex tubes are substituted for the intercooler due to their many intrinsic benefits in many industrial fields as parts for refrigerating machines, the cooling efficiency could be advanced in the low speed range. In this study, a counter-flow type of vortex tube is employed to investigate the temperature separation characteristics with various geometric configurations for optimization of charging air cooling. A parametric study was conducted to evaluate the performance of the vortex tube with various geometric structures and operating inlet pressures. The results show that variation of the cold exit orifice hole diameter significantly influences the energy separation between two exits.

An evaluation of the concrete strength has very important meaning in the maintenance and the structural safety. The reliability of ferroconcrete building is weakening and enlarging the life is strongly demanded due to the early deterioration of concrete. Like this social demand, concrete strength presumption is being indirectly executed using the result in parallel with the concrete pouring by material age. This data is usually different as concrete poured practically and the way of hardening and curing. Although existing concrete strength presumption formula is proposed, the material used and the concrete strength is different. And as a matter of remicon, the concrete strength varies according to the site and the way of curing. So the objective of this research is strength evaluation of the structural body concrete according to the concrete pouring and curing temperature change seasonally after using the system which evaluates the structural body concrete strength which is applied the transparent junction-separation mold that is presented. Also there is an objective to present the fundamental data for the constructional quality technique proposal of the structural body concrete developed in relation to field specimen and the strength evaluation method by non-breaking.

For the fabrication of core-shell structure bimetallic lead-free solder balls, both the critical temperature (Tcr) for the phase separation of two immiscible liquid phases and the temperature coefficient of the interfacial tension between the two separated liquid phases are required. In order to obtain this information, the temperature dependence of the surface tension of 60%Bi-24%Cu-16%Sn(-REM) alloys was measured using the constrained drop method. The slope of the temperature dependence of the surface tension changed clearly at a critical temperature for the separation of two immiscible liquid phases. The critical temperature of the 60%Bi-24%Cu-16%Sn alloy was estimated to be 1097K. An addition of 0.05% Ce decreased the critical temperature to 1085K, whereas that of 0.05% La increased it to 1117K. It was found that the surface tension and its temperature coefficient of the 60%Bi-24%Cu-16%Sn alloy were slightly increased by the addition of 0.05% Ce and 0.05% La. In addition, additions of Ce and La increased the temperature coefficient of the interfacial tension.

고정발생원으로 부터 배출되고 있는 이산화탄소를 분리하여 회수 및 재이용하는 기술개발이 에너지 보전 측면에서 뿐만 아니라 환경오염 문제 등을 해결할 수 있는 중요한 과제이다. 특히 내열성, 내식성 및 기계적 강도가 뛰어난 세라믹의 특성을 이용한 기체분리막을 응용한다면 고온으로부터 저온까지의 폭넓은 온도, 압력, 가스조성의 배기가스로부터 이산화탄소를 분리하는 것이 가능해 진다. 따라서 본 총설에서는 현재 일본에서 국책과제로 진행되고 있는 이산화탄소의 고온분리에 대한 연구개발(이하, 'CO2 프로젝트'로 약칭) 현황을 소개하고자 한다.

Laboratory experiments were conducted to investigate the effect of digestion temperature on the settleability and dewaterability of anaerobically digested sludge. The digesters were operated at a hydraulic retention time of 20 days with a loading rate of 0.63~0.66kg volatile solids per cubic meter per day at the temperature of $35^{\circ}C$ and $55^{\circ}C$. A mixed primary and secondary municipal sludge was used as a feed. The interface height of the sludge during settling test was recorded to identify settleability. As a measure of dewaterability of the sludge, specific resistance and capillary suction time were also measured with and without chemical conditioning. Higher digestion efficiency was obtained at $55^{\circ}C$ than $35^{\circ}C$. However, the settleability and dewaterability of the sludge at $35^{\circ}C$ were quite higher than those of the sludge digested at $55^{\circ}C$. The optimum dosages of ferric chloride for sludge conditioning were 0.4% and 0.6% at $35^{\circ}C$ and $55^{\circ}C$, respectively. The filtrate COD of the sludge digested at $55^{\circ}C$ was higher than at $35^{\circ}C$, which means that poor dewaterability of the sludge result in high filtrate COD.