• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.4
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• pp.355-359
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• 2009

Si wafer, which was treated with TMSP-TBA (N-trimethoxysilylpropyl-n,n,n-tri-n-butylammonium bromide), was used foF a substrate to grow a MFI membrane. Growth of membranes was conducted in various conditions such as temperature and gravity, and their structures were in detail studied with field emission scanning electron microscope and x-ray diffractometer. The structures of membranes grown on substrates were strongly dependent on growing temperature and gravity.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.11a
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• pp.17-21
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• 2003

This study is mainly acceptive for physical material performance than waterproofing layer performance on the external condition after construction. The reason are legalized only for material performance quality standard even though it is existed waterproofing materials for membrane. In actuality, waterproofing layer are greatly occurred in performance a decreased developing essential element that are human footprints as a result physical perimeter environment after construction and on the construction. As the result, this present paper purpose for evaluation and performance of the membrane waterproofing layer on the construction.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.05a
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• pp.17-21
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• 2003

This study is mainly acceptive for physical material performance than waterproofing layer performance on the external condition after construction. The reason are legalized only for material performance duality standard even though it is existed waterproofing materials for membrane. In actuality, waterproofing layer are greatly occurred in performance a decreased developing essential element that are human footprints as a result physical perimeter environment after construction and on the construction. As the result, this present paper purpose for evaluation and performance of the membrane waterproofing layer on the construction.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.8
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• pp.658-662
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• 2001

This paper describes on the fabrication and characteristics of hot-film type micro-flowsensors integrated with Pt-RTD(resistance thermometer device) and micro-heater on the SOI(Si-on-insulator) membrane and trench structures, in which MGO thin-film was used as medium layer in order to improve adhesion of Pt thin-film to SiO$_2$ layer. Output voltages increased due to increase of heat-loss from sensor to external. The output voltage was 250 nV at N$_2$ flow rate of 2000 sccm/min, heating power of 0.3 W. The response time($\tau$:63%) was about 42 msec when input flow was step-input. The results indicated that micro-flowsensors with the SOI membrane and trench structures have properties of a high-resolution and ow consume power.

• Korean Chemical Engineering Research
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• v.57 no.1
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• pp.17-21
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• 2019

The redox flow battery (RFB) is a large-capacity energy storage equipment, and the vanadium redox flow cell is a typical RFB, but VRFB is expensive. Iron-chrome RFBs are economical because they use low-cost active materials, but their low performance is an urgent problem. One of the reasons for the low performance is the crossover of the active materials. In this study, the sulfonated Poly (ether ether ketone) (sPEEK) membrane, which is a hydrocarbon membrane, was used instead of the fluorine membrane to reduce the crossover of the active materials. The chromium ion permeability of the sPEEK membrane was $1.8{\times}10^{-6}cm^2/min$, which was about 1/33 of that of the Nafion membrane. Thus, it was shown that the use of the sPEEK membrane instead of the fluorine membrane could solve the high active material crossover problem. The activation energy of iron diffusion through the sPEEK membrane was 24.9 kJ/mol, which was about 66% of Nafion membrane. And that the e-PTFE support in the polymer membrane reduces the active material crossover through Iron-Chrome Redox Flow Battery (ICRFB).

• Membrane Journal
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• v.3 no.1
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• pp.22-28
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• 1993

Fabrics of polyester, polyacrylics, nylon and cotton were tested to investigate the possibility. of using these matehals as a membrane support sheet. Considering the physical properties such as compaction rate, membrane embossing, water flux, the chemical and mechanical properties, 50 denlet polyester fabrics was found to be the appropriate material as a membrane support sheet among the tested materials. The experimental parameters such as pressure drop, compression pressure and viscosity were changed to investigate the effects of these parameters on the flow patten in this membrane support sheet. As a result, it was shown that Darcy's law could be satisfactorily applied to describe the flow pattern in this membrane support sheet.

• Membrane Journal
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• v.7 no.2
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• pp.57-64
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• 1997

Membrane Distillation(MD) is reviewed as an application to new separation technology. Hydrophobic membrane which has been used to microfiltration is feasible material for MD process. MD has perfect selectivity under moderate temperature and is promised to simplify typical water treatment process. The principle of MD separation is phase transition by vapor-liquid interface at the pore of membrane surface. Feed and permeate temperature, composition, membrane wetting, heat and mass transfer phenomena affect the selectivity and flux of MD.

• Journal of Environmental Science International
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• v.17 no.11
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• pp.1235-1241
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• 2008

Membrane separation is extensively used for water/wastewater treatment because of its efficiency separation processes. However, particles in the feed water can deposit and accumulate on the membrane surface to created cake layer. As a consequence, the selectivity of the membrane and flux through the membrane are decreased, which is called fouling/blocking phenomenon. In order to solve fouling problem, we developed a novel membrane named Carbon Whisker Membrane (CWM) which contains vapor-grown carbon fibers/whiskers on the surface of the membrane and a layer of carbon film coated on the ceramic substrate. We firstly employed polymethyl methacrylate (PMMA) as a testing material to investigate the fouling mechanism. The results suggested that Carbon Whiskers on the surface of the membrane can prevent the directly contact between the membrane body and particles so that the fouling/blocking could not occurred easily compared to the membrane without carbon whiskers. We also researched the relationship with the diameter, density of carbon whisker on the membrane surface and total flux of solutions. Finally, we will be able to control the diameter and density of carbon whiskers on the membrane and existence of carbon whiskers on the membrane, it is important factor, might be prevent fouling/blocking in the water treatment.

• Journal of Korean Association for Spatial Structures
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• v.5 no.1 s.15
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• pp.91-98
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• 2005

Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. Therefore membrane structures are unstable structures initially. These soft structures need to be introduced initial stresses first because of its initial unstable state, and it happens large deformation phenomenon. To find the structural shape after large deformation caused by initial stiffness introduced, we need the shape analysis considering geometric nonlinearity in structural design procedure In this study, we analyze the soft spatial structures by the NASS which is the program for nonlinear analysis. The analytic model is a roof membrane structures of Barrel Vault-Type. We have done the shape analysis and the stress-deformation analysis considering the orthotropic material, and then study the safety.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.428-439
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• 2021

A spray-on membrane is a material composed of a polymer, and is a spray-type material that is expected to be able to replace materials such as existing shotcrete or sheet membrane for support or waterproofing purposes. In the previous studies, it is expected that the thickness of the support material such as shotcrete can be reduced if the spray-on membrane is additionally installed on the existing cement-based support materials. In this study, a three-point bending test was performed by a spray-on membrane on the high-performance shotcrete on the outside, and comparison was made between the case where high-performance shotcrete and a spray-on membrane were installed. As a result of comparing the values calculated through the standard test and the real-size bending test, there was no significant difference in terms of flexural strength, but it was found that there was a difference in flexural toughness.