• 한국재료학회지
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• 제29권9호
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• pp.553-558
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• 2019

$Cu_2ZnSn(S,Se)_4(CZTSSe)$ thin film solar cells areone of the most promising candidates for photovoltaic devices due to their earth-abundant composition, high absorption coefficient and appropriate band gap. The sputtering process is the main challenge to achieving high efficiency of CZTSSe solar cells for industrialization. In this study, we fabricated CZTSSe absorbers on Mo coated soda lime glass using different pressures during the annealing process. As an environmental strategy, the annealing process is performed with S and Se powder, without any toxic $H_2Se$ and/or $H_2S$ gases. Because CZTSSe thin films have a very narrow stable phase region, it is important to control the condition of the annealing process to achieve high efficiency of the solar cell. To identify the effect of process pressure during the sulfo-selenization, we experiment with varying initial pressure from 600 Torr to 800 Torr. We fabricate a CZTSSe thin film solar cell with 8.24 % efficiency, with 435 mV for open circuit voltage($V_{OC}$) and $36.98mA/cm^2$ for short circuit current density($J_{SC}$), under a highest process pressure of 800 Torr.

• 펄프종이기술
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• 제47권4호
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• pp.81-87
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• 2015

Soda-AQ pulp made from sugarcane bagasse (SCB) were bleached in element chlorine free (ECF) sequence. To reduce chlorine dioxide use, final peroxide bleaching was introduced. Prior to peroxide bleaching, different chelating chemicals were applied for comparative analysis in ISO brightness and viscosity. When using equal total chlorine dioxide usage (4.5%), bleached SCB pulp using chelate and hydrogen peroxide (DEDQP) was reached 86.8% (DTPA), 86.4% (EDTA) ISO brightness, whereas bleached pulp using only hydrogen peroxide (DEDP) reached at 81.2% ISO brightness. Viscosity of DEDQP bleached pulp was 25.6 cPs (DTPA), 25.2 cPs (EDTA), And DEDP bleached pulp was shown 18.0 cPs viscosity. Decreasing of transition metal by chelate process led to improvements in final brightness along with higher viscosity. Due to EDTA is 5-7 times cheaper than DTPA, EDTA is recommended as chelating chemical prior to peroxide bleaching.

• 한국전기전자재료학회논문지
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• 제30권11호
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• pp.734-739
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• 2017

We prepared $SnS_x$ thin films on both soda-lime glass (SLG) and molybdenum(Mo)/SLG substrates by a two-step process using a Sn precursor followed by sulfur reaction in rapid thermal annealing (RTA) at different sulfurization temperatures ($Ts=200^{\circ}C$, $230^{\circ}C$, $250^{\circ}C$, and $300^{\circ}C$) and annealing times ($t_s=10min$ and 30 min). The single SnS phase was dominant for $200^{\circ}C{\leq}T_s$<$250^{\circ}C$, while an additional phase of $SnS_2$ was appeared at $T_s{\geq}250^{\circ}C$ alongside SnS. The SnS grains in all the samples showed strong growth along the preferred [040] direction. The band-gap energy ($E_g$) of the films was estimated to be 1.24 eV.

• 한국안광학회지
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• 제12권1호
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• pp.17-22
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• 2007

Ti-나프텐산염과 금속을 출발원료로 사용하고, 스핀코팅-열분해법을 이용하여 실리카 유리위에 박막을 제조하였다. 도포된 박막은 $500^{\circ}C$ 공기에서 10min동안 열처리하였다. 이를 5회 코팅한 박막은 마지막으로 공기에서 $600^{\circ}C$에서 30min으로 하였다. 박막의 특성을 분석하기 위하여 X-선 회절 분석, 전자현미경, UV스펙트럼을 이용하여 분석하였다. 밴드갭에서 가장 큰 장파장 쪽으로 이동은 Fe을 도핑한 $TiO_2$ 박막이었다.

• 멤브레인
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• 제1권1호
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• pp.5-12
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• 1991

Since the discovery of the Loeb-Sourirajan reverse osmosis membrane, thirty years have passed and many membrane technologies and new membranes for applications have been developed in the world. In the early stage of these developments Japan has not contributed much, but from the middle of 70ties Japan has started its own R&D projects starting from the desalination technology, and now various private industries and government ministries are actively engaging in R & D of membrane technologies in Japan. In Table 1 the chronological developments of important events of developments and projects relating membrane technologies inside and outside of Japan are introduced and their details will be explained. The first membrane technology applied in the Japanese industry was a electrodialysis(ED) process using ion-exchange membranes. These membranes were first developed in early 50ties and the Japanese government decided to use this method for concentration of sea-water to produce salt, which was then produced by solar evaporation. This development program started from 1960 by the Japan Monopoly Corp.(at that time). To apply ED process for sea-water concentration it was necessary to develop ion-exchange membranes having very low electric resistance to avoid energy loss due to Joule heat, and those having selectivity to permeate single valent ions only to avoid scale formation in the ED stacks. Three Japanese companies, Asahi Glass, Asahi Chemical and Tokuyama Soda, have succeeded to develop such membranes, and until 1971 all of the seven salt manufacturing companies had adopted ED for production of food salt.

• 대한기계학회논문집A
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• 제25권4호
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• pp.629-636
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• 2001

In order to investigate the possibility of impact punching in brittle materials, an experimental setup was developed. In the setup, a long bar as a punch was used to apply the impact load to the specimen plate and measure the applied impact force during the impact punching process. Impact punching tests with various shape of punches were performed in soda-lime glass and silicon wafer under a different level of contact pressure. The damage appearance after the impact punching was examined according to the applied contact pressure. The minimum contact pressure required for a complete punching in glass specimens without development of radial cracks around the punched hole was sought at each condition. The minimum contact pressure increased with increasing the thickness of specimens and decreasing the end radius of punches. The profile of impact forces was measured during the impact punching experiment, and it could explain well the behavior of the punching process in brittle material plates. The measured impact force increased with increasing the contact pressure applied to the plates.

• 한국기계가공학회지
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• 제8권3호
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• pp.68-73
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• 2009

This paper deals with the dynamic characteristics of the impeller shaft model which is the most important part in developing the resin mixing machine. The can is rotating by air motor in mixing machine. Then the end of shaft is fixed. The bearing support is to increase the fundamental natural frequency. The natural frequency analysis using finite element analysis software are performed on the imported commercial impeller shaft model. This paper presents calculated bearing stiffness of Soda, Harris and modified Harris formula considering contact angle according to bearing supported position. The most important fundamental natural frequency of the impeller shaft except bearing support is around 13.932 Hz. This paper presents one bearing and two bearings support position to maximize the 1st natural frequency. The maximized fundamental natural frequency is around 48.843 Hz in one bearing support and 55.52 Hz in two bearings support.

• 멤브레인
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• 제4권3호
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• pp.163-170
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• 1994

본 연구에서는 전기투석법을 이용하여 아미노산 수용액중에 존재하는 전해질인 무기염의 분리 정제에 관하여 고찰하였다. 생물 분리기술로서 아미노산의 등전위점을 이용한 전기투석법의 적합성을 검토하기 위하여 음이온교환막, NEOSEPTA AM1(Tokuyama Soda Co. Ltd., Japan)과 양이온교환막 CM1 (Tokuyama Soda Co. Ltd., Japan)막을 사용한 전기투석조를 설계하였고 아미노산 발효공정과 유사한 계를 만들어서 무기염인 NaCl의 분리실험을 하였다. 즉, 운전조건을 설정하기 위해 pH에 따른 아미노산의 누설량, 한계전류 밀도를 측정한 후, 이를 바탕으로 회분식과 연속식 실험으로 염의 제거량과 아미노산의 누설량을 정량적으로 고찰하고 전류효율을 구하였다. 회분식 장치에서 아미노산 수용액별로 11시간동안 운전한 결과 NaCl의 제거효율은 96.1~96.2%이었고, 아미노산의 누설율은 glycine의 경우 2.5%, methionine의 경우 1.7%, alanine의 겨우 2.0%이었으며, 전류효율은 44.5~44.6% 범위이었다. 연속식 장치에서는 아미노산 수용액별로 dilution rate을 1.0~3.9$h^{-1}$로 변화시켜 실험한 결과, 120~150분 사이에 정상상태에 도달하였고, 유속이 작을수록 염의 제거 효율은 증가하였으나 전류효율은 감소하였다. 이때 아미노산의 누설은 거의 없었다.

• 보존과학회지
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• 제33권5호
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• pp.331-344
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• 2017

본 연구에서는 오산 수청동 유적에서 확인된 10가지 색상 중 다수를 차지하는 적갈색, 벽색, 감청색을 연구시료로 선정하여 화학 조성을 중심으로 각 색상별 유형을 분류하고 이에 따른 시기별 전개 양상을 살펴보았다. 유형 분류한 결과, 적갈색과 감청색은 5가지, 벽색은 4가지 유형으로 구분된다. 이를 출토 유구의 시기별로 살펴볼 때, 적갈색은 2가지, 벽색과 감청색은 1가지 유형이 시기의 연속성을 보여 각 색상의 주된 유형으로 판단된다. 주된 유형은 산화알루미늄($Al_2O_3$)의 안정제 함량이 높은 소다유리군인 공통적 특징을 보여 본 유적 조영집단은 지속적으로 유리구슬을 교역한 경로를 가지고 있었을 것으로 추정된다. 또한 오산 수청동 유적은 4세기 후엽 유구에서 다양한 유형이 확인되어 이전시기에 비하여 다양한 유통 경로를 통해 유리구슬이 유입되었을 가능성이 높다고 할 수 있다.

• 한국전기전자재료학회논문지
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• 제26권7호
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• pp.503-509
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• 2013

In this study, $Cu(In_{1-x},Ga_x)Se_2$ (CIGS) thin films were prepared on the Mo coated soda-lime glass by the DC magnetron sputtering and a subsequent selenization process. For the selenization process, selenization rapid thermal process(RTP) with cracker cell, which was helpful to smaller an atomic of Se, was adopted. To make CIGS layer, they were then annealed with the cracked Se. Based on this selenization method, we made several CIGS thin film and investigated the effects of In deposition time, and selenization time. Through x-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and atomic force microscopy (AFM), it is found that the Mo/In/CuGa structure and the high sputtering power shows the dominant chalcopyrite structure and have a uniform distribution of the grain size. The CIGS films with the In deposition time of 5 min has the best structure due to the smooth surface. And CIGS films with the selenization time of 50 min show good crystalline growth without any voids.