• Korean Chemical Engineering Research
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• v.43 no.4
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• pp.439-451
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• 2005

This article provides a panoramic overview of the state-of-the-art technologies in the field of solid-state hydrogen storage methods. The emerging solid-state hydrogen storage techniques, such as nanostructured carbon materials, metal organic framework (MOFs), metal and inter-metal hydrides, clathrate hydrates, complex chemical hydride are discussed. The hydrogen storage capacity of the solid-sate hydrogen storage materials increases in proportion to the surface area of the solid materials. Also, it is believed that new functional nanostructured materials will offer far-reaching solutions to the development of on-board hydrogen storage system for the application of the transportation vehicles.

• Journal of the Korean Institute of Gas
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• v.26 no.3
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• pp.1-9
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• 2022

The causes of accidents occurring in chemical plants vary, but 96% of industrial accidents occurring worldwide are caused by workers' unsafe behavior. The International Labour Organization (ILO) has announced 20 elements of workers' anxiety-warning behaviors that occur on multiple occasions at industrial sites in order to warn them of the risk of accidents caused by workers' anxiety-driven behavior, and to prevent industrial accidents, workers' anxiety-driven behavior should be controlled under stress In this study, major types of unsafe behavior were analyzed on the basis of information on the accident investigation history of domestic workspaces in order to find out how workers can manage their unsafe behavior. Based on the results of the analysis of the major anxiety war behavior, the root cause of causing anxiety war behavior was analyzed using the Swiss Cheese Model, and each root cause management method was proposed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.230-233
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• 2008

Stainless steels are alloy steels with iron as the primary constituent and chromium, nickel, and manganese as principal alloying elements. In addition to automotive, construction, and transportation industries, stainless steels have a variety of applications in the food, chemical, and pharmaceutical industries. Some common products made from stainless steel are sinks, wash basins, kitchen vessels, and cutlery. Among ferritic stainless steels, type 409 can be cold-formed easily and are used for deep-drawn parts such as vessels for the chemical and food industries. In this study, forming analyses and experiments to prevent the occurrence of inferiority such as wrinkles, crack, and neck for automotive muffler part are carried out to save the optimal conditions during forming by modifying the blank size and shape, blank holding force etc.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.57.1-57.1
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• 2010

Development of low cost hybrid functional nano-structured materials has great interest to enhance sensitivity of dye-sensitized solar cells and reduction of the production cost. In this talk we will discuss about using different processes to modify functional characteristics of photoelectrode and investigate effects of chemical modification without significant structural variation on to enhance performance of DSSCs. Efficient electron transportation between dye molecules and photoelectrode has been obtained by appropriate chemical modification and efficiency of DSSC has been significantly improved. A comparative analysis on effects of surface functional and electron states of photoelectrode on VOC and JSC has been also carried out to discuss effects of composite materials on physical structure and electronic properties to correlate enhanced performance of these devices.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.376-379
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• 1996

Synthesis for qualitative analysis in connection with quantitative analysis from the pinch design method, EVOP and Operations Research is proposed for the optimal synthesis of heat exchanger networks, that is through of the transportation model of the linear programming for synthesizing chemical processing systems, to determine the location of pinch points, the stream matches and the corresponding heat flowrate exchanged at each match. In the second place, according to the optimization, the optimal design of heat transfer enhancement is carried on a fixed optimum heat exchanger network structure, in which this design determines optimal operational parameters and the chosen type of heat exchangers as well. Finally, the method of this paper is applied to the study of the optimal synthetic design of heat exchanger network of constant-decompress distillation plants.

• 한국가스학회:학술대회논문집
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• 1997.09a
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• pp.284-291
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• 1997

배관망의 해석은 유체역학을 필요로 하며 관내의 유체의 거동과 운전 상태에 따른 유동해석을 위해 여러 식들이 사용되어왔다. 본 연구에서는 정상상태의 유량방정식을 사용해 경인지역가스 배관망에 대한 수학적 모델을 만들고 모사 및 분석을 수행하였다. 개발된 수학적 모델에서 얻어진 데이터에 통계학적인 방법을 도입해 통계학적 모델을 만듦으로써 통계학적 모델을 이용한 배관망 해석의 가능성에 대해 검토하였다.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3586-3590
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• 2013

We present here an efficient and simple method for preparation of highly active heterogeneous ZnO photocatalyst (graphene oxide-zinc oxide: GO-ZnO), specifically by deposition of ZnO nanoparticles onto thiolated GOs. The resultant GO-ZnO sample was characterized by TEM, XRD, Auger, XPS, and Raman measurements, revealing that the size-similar and quasi-spherical ZnO nanoparticles were anchored to the thiolated GO surfaces. The average particle diameter was about 2.5 nm. In the photodegradation of methylene blue (MB) under ultraviolet (UV) light, GO-ZnO exhibited remarkably enhanced photocatalytic efficiency compared with thiolated GO and pure ZnO particles. This strong photocatalytic performance of GO-ZnO can be attributed to the suppression of electron recombination and the enhancement of mass transportation. The results showed that thiolated GO is the preferable supporting material.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.358-359
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• 2005

Chemical mechanical polishing(CMP) process depends on a variety of variables. Especially, surface roughness of pad plays a key role in material removal in CMP in terms of transportation ability of pores and real contact area. The surface roughness is deteriorated with polishing time by applied pressure and relative velocity. In this reason, diamond conditioner has been used to maintain the roughness on the pad. The authors try to investigate the correlation between pad roughness and frictional behavior by comparing ex-situ conditioning with in-situ conditioning.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1048-1050
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• 2008

Electric current flow was observed through imogolite film when imogolite ($(HO)_3Al_2O_3SiOH$) was exposed to water molecules and connected to external electrodes. Current flow was due to the bound water on the surface of imogolite. Current flow increased as the pH of the water decreased. The current-voltage (I-V) measurements from a field effective transistor (FET) using $H_2O$/imogolite film revealed that the current carrier in $H_2O$/ imogolite had p-type characteristics, i.e. the carrier was probably $H^+$. The possible mechanism for current transportation in imogolite/water was also suggested in this paper.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.618-623
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• 2020

Spherical phenolic resin beads were synthesized by suspension polymerization at 98 ℃ from phenol, ortho-cresol, formaldehyde, with triethylamine as a basic catalyst, and spherical phenol-cresol copolymer resin beads with relatively low crosslinking density as well. Phenol reacts with formaldehyde at two ortho- and one para- positions to form a crosslinked structure, but ortho-cresol instead of phenol reduces the crosslinking density during copolymerization due to the methyl group at a ortho- position. As a result, spherical phenol-cresol copolymer beads showed more shrinkage with decreasing apparent density compared to the spherical phenol beads when carbonized at 700 ℃ under nitrogen. As the molecular weight of the cresol oligomer increases, the pore radius of the carbonized copolymer beads decreases, which is consistent with the density and shrinkage results. It was confirmed that the characteristics such as density decrease, shrinkage, yield and so on during carbonization can be controlled by controlling the degree of crosslinking of the spherical phenolic resin particles with cresol.