A Comparative Study of Nanoparticle-Ink-Based CIGSSe Thin Film Solar Cells on Different Back Contact Substrates

Se Jin Park,Jin Woo Cho,Gi Soon Park,Jae Seung Jeong,김지현,고두현,황윤정,민병권 대한화학회 2016 Bulletin of the Korean Chemical Society Vol.37 No.3

The effect of the back contact electrode in nanoparticle-ink-based CIGSSe solar cells was investigated using different glass substrates with either a fluorine-doped SnO2 (FTO) conducting layer or a molybdenum (Mo) conducting layer. The morphologies, crystal structures, and compositional distributions of the Cu(In x Ga1– x )(S y Se1– y )2(CIGSSe) films are very similar in spite of the different back contact materials. The observed performances of the solar cell device, however, are somewhat different. The device that was fabricated on the FTO back contact substrate revealed a lower open-circuit voltage ( V oc) and fill factor (FF) than the Mo back contact substrate, resulting in lower solar cell efficiencies (6.5% for FTO and 7.4% for Mo). The differences between the behaviors are attributed to the interfacial properties between the CIGSSe film and the back contact electrode.

Chalcogenization-Derived Band Gap Grading in Solution-Processed CuIn_<i>x</i>Ga_1–<i>x</i>(Se,S)₂ Thin-Film Solar Cells

Park, Se Jin,Jeon, Hyo Sang,Cho, Jin Woo,Hwang, Yun Jeong,Park, Kyung Su,Shim, Hyeong Seop,Song, Jae Kyu,Cho, Yunae,Kim, Dong-Wook,Kim, Jihyun,Min, Byoung Koun American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.49

<P>Significant enhancement of solution-processed CuInxGa1-x(Se,S)(2) (CIGSSe) thin-film solar cell performance was achieved by inducing a band gap gradient in the film thickness, which was triggered by the chalcogenization process. Specifically, after the preparation of an amorphous mixed oxide film of Cu, In, and Ga by a simple paste coating method chalcogenization under Se vapor, along with the flow of dilute H2S gas, resulted in the formation of CIGSSe films with graded composition distribution: S-rich top, In- and Se-rich middle, and Ga- and S-rich bottom. This uneven compositional distribution was confirmed to lead to a band gap gradient in the film, which may also be responsible for enhancement in the open circuit voltage and reduction in photocurrent loss, thus increasing the overall efficiency. The highest power conversion efficiency of 11.7% was achieved with J(sc) of 28.3 mA/cm(2), V-oc of 601 mV, and FF of 68.6%.</P>

체간안정화 훈련이 만성 뇌졸중 환자의 호흡기능에 미치는 효과

이경진(Kyeong-Jin Lee),정주현(Ju-Hyeoun Jeong),조명래(Myeong-Rae Jo),김세윤(Se-Yoon Kim),김난수(Nan-Soo Kim) 대한심장호흡물리치료학회 2019 대한심장호흡물리치료학회지 Vol.7 No.1

Purpose : The purpose of this study is to examine the effects of trunk stability training on improving trunk control, respiratory function, and respiratory muscle activation in stroke patients. Methods : The subjects were assigned to two groups: the intervention group (n=15) and the control group (n=15). Both groups participated in a conventional stroke rehabilitation program, but the intervention group also received trunk stability training for 30 minutes a day, 3 times a week, for 6 weeks. The main trunk stability exercise consisted of the dead bug exercise. Trunk control was assessed using a trunk impairment scale, and respiratory function (pulmonary function and respiratory muscle function) was assessed using spirometry. The data were analyzed using the Pearson correlation, independent t-test, and paired t-test. Results : Trunk control was significantly positively correlated with pulmonary function and respiratory muscle strength. Both groups showed a significant increase in trunk control and respiratory function. Conclusion : This study demonstrated that a conventional stroke rehabilitation program and trunk stability training have positive effects on respiratory function and respiratory muscle activation in stroke patients.

포화수증기압 개념에 대한 예비 과학 교사들의 이해

정진우,박세진,김윤지 韓國敎員大學校 敎育硏究院 2009 敎員敎育 Vol.25 No.4

본 연구는 예비과학교사들이 포화수증기압 개념을 설명하는 과정에서 나타나는 이해를 밝히고자 하였다. 과학교육을 전공하는 여섯 명의 예비과학교사들을 대상으로 포화수증기압에 대한 설명을 요구하는 반구조화된 면담이 이루어졌다. 전사된 면담 내용과 비디오자료, 그리고 설명 과정에서 그려진 스케치 자료를 분석하여 참여자의 이해를 구조화하였다. 연구 결과, 예비과학교사가 대기 중의 물 개념을 설명하는 과정에서 다양한 이해가 표출되었다. 포화수증기압에 대한 이해로 분자운동론적 설명, 대기의 영향을 고려한 분자운동론적 설명, 기화압력을 이용한 설명, 확산 개념을 이용한 설명, 수증기의 공간을 한정시키는 설명이 나타났다. 예비과학교사들은 포화수증기압 개념에 대해 다양한 대안 개념을 가지고 있으며, 물의 상태 변화에 대한 분자운동론적 이해와 포화수증기압 개념을 통한 이해가 서로 연결되지 못하고 있음을 보여주었다. The purpose of this study is to analyze the understandings that represent that, in this course, the preservice science teachers have explained the concept of saturation vapor pressure. To do so, semi-structured interviews that requested students to explain saturation vapor pressure to six preservice science teachers were carried out. The preservice science teachers' understanding of the material was constructed by analyzing transcribed protocols, video tapes, and sketches that were drawn during the explanation. As a result of the research, a variety of understandings was discovered when the preservice science teachers explained the concept of atmospheric water. Understandings about saturation vapor pressure include the idea of molecular motion; the molecular motion model is considered to influence atmospheric pressure, the evaporation pressure model, the diffusion model and the limited space model. Preservice science teachers had alternative conceptions of saturation vapor pressure. The understanding of saturation vapor pressure and the understanding of the molecular motion model describing the change of water state are not connected.

이성분 양이온성 계면활성제 혼합용액의 임계미셀농도에 대한 연구 1. CTAB와 다른 양이온성 계면활성제 CTB 및 DTAB 혼합용액

김진형,오세웅,고정수 木浦大學校基礎科學硏究所 1999 基礎科學硏究誌 Vol.17 No.-

The critical micelle concentration (??) in a micellar state of the mixed surfactant systems of cetyltrimethylammonium bromide (CTAB) with cetylpyridinium bromide(CPB) and dodecyltrimethylammonium bromide (DTAB) were determined at 25℃ as a function of the overall mole fraction of CTAB by the use of surface tension method. CMC values of pure CTAB, CPB, and DTAB were 9.95×10-4 M, ?? M, and ?? M, respectively. Interaction parameterβ value of CPB-CTAB mixture was evaluated as -1.3. In case of DTAB-CTAB mixture, constancy in β value was not obtained over all composition of the mixture.

복합 산화법과 MEMS 기술을 이용한 RF용 두꺼운 산화막 에어 브리지 및 공면 전송선의 제조

김국진,박정용,이동인,이봉희,배영호,이종현,박세일 한국센서학회 2002 센서학회지 Vol.11 No.3

본 논문에서는 양극반응과 복합 산화법( H_2O/O_2 분위기에서 500℃, 1시간 열산화와 1050℃, 2분간 RTO(Rapid Thermal Oxidation) 공정)을 이용한 두꺼운 OPSL(Oxidized Porous Silicon Layer)을 형성하여 이를 마이크로머시닝 기술을 이용함으로써 10 ㎛두께의 OPS(Oxidized Porous Silicon) 에어 브리지를 제조하고, 그 위에 전송선로를 형성하여 그 RF 특성을 조사하였다. OPS 에어 브리지 위에 형성된 CPW(Coplanar Waveguide)의 손실이 OPSL 위에 형성된 전송선의 삽입손실보다 약 2 dB 정도 적은 것을 보여주었으며, 반사손실은 OPSL 위에 형성된 전송선의 반사손실보다 적으며 약 -20 dB를 넘지 않고 있다. 본 연구에서 개발한 산화된 다공질실리콘 멤브레인 및 에어 브리지 구조는 CMOS 공정 후에 사용 가능하며, 초고주파 회로 설계시 편리성과 유용성을 제시하고 있다. This paper proposes a 10 ㎛ thick oxide air-bridge structure which can be used as a substrate for RF circuits. The structure was fabricated by anodic reaction, complex oxidation and micromachining technology using TMAH etching. High quality films were obtained by combining low temperature thermal oxidation (500 ℃,1 hr at H_2O/O_2) and rapid thermal oxidation (RTO) process (1050 ℃, 2min). This structure is mechanically stable because of thick oxide layer up to 10 ㎛ and is expected to solve the problem of high dielectric loss of silicon substrate in RF region. The properties of the transmission line formed on the oxidized porous silicon (OPS) air-bridge were investigated and compared with those of the transmission line formed on the OPS layers. The insertion loss of coplanar waveguide (CPW) on OPS air-bridge was (about 2 dB) lower than that of CPW on OPS layers. Also, the return loss of CPW on OPS air-bridge was less than about - 20 dB at measured frequency region for 2.2 mm. Therefore, this technology is very promising for extending the use of CMOS circuitry to higher RF frequencies.

銳敏化된 304 스텐레스鋼의 水素脆性에 관한 硏究

金貞錫,金辰漢,朴世潤 부산대학교 공과대학 1987 硏究報告 Vol.33 No.-

This paper discusses the hydrogen embrittlement observed when static load tests were run on sensitized type 304 stainless steel specimens. The specimens were cathodically charged with hydrogen at room temperature in a in solution of H₂SO₄to which was added 100mg of sodium arsenite (As₂O₃) per liter using a platinum anode at various current densities. When hydrogen is introduced into the Cr depleted zone, the austenitic lattice is expanded, are it causes the dislocation and stacking fault density and induce partial transformation of the austenite to the martensitic phases α(bcc) and ε(hcp). The increase in hydrogen cracking susceptibility by sensitizing is attributed to deformation induced martensite. The fracture mode was changed from intergranular to transgranular by cold working and sensitizing.

토양으로부터 항세균성 물질을 생산하는 Streptomyces sp. 의 분리

오현정,정완석,김세재,김창진,고영환 제주대학교 생명과학연구소 1999 제주생명과학연구 Vol.2 No.-

제주도의 토양에서 분리된 방선균 307주를 대상으로, paper disc법과 시험관 희석 배양법을 사용하여 항세균성 물질을 생산하는 균주를 선별하였다. 약 3.3%에 상당하는 분리주들이 Escherichia coli 8749, Staphylococcus aureus 6538 그리고 Pseudomonas solanacearum 10692에 대해 항균효과를 나타냈고, 그 중에서 가장 높은 항균활성을 나타내는 BL93 균주를 최종선별하여 동정하였다. BL93 균주의 배양학적, 형태학적, 생리학적, 생화학적 그리고 화학분류학적 특성을 기준으로 볼 때 Streptomyces violaceus와 유사하였기에, Streptomyces sp. BL93으로 명명하였다. 이 균주가 생산하는 항세균성 물질은 butanol보다도 물에 더 잘 녹는 극성화합물로 chloroform이나 ethylacetate에는 거의 용해되지 않았다. 100℃에서 30분간 가열 처리해도 활성의 소실이 거의 없었고, pH 3∼9범위에서 안정하였다. 분리균주 BL93은 aspartocin을 생산하는 Streptomyces violaceus와 유사함으로, BL93이 생산하는 항세균성 물질의 동정 및 aspartocin과의 비교 검토가 선행되어야 할 것이다. Three hundred and seven isolates of Actinomycetes were isolated and purified from soil samples in Cheju Is. to screen antibacterial compounds. About 3.3% of the isolates showed antibacterial activity, and one of them, BL93, showed relatively higher antibacterial activity against Escherichia coli 8749, Staphylococcus aureus 6538 and Pseudomonas solanacearum 10692 by both paper disc method and tube dilution incubation method. The isolate BL93 was similar to Streptomyces violaceus based upon its cultural, morphological, physiological, biochemical and chemotaxanomic characteristics. It was designated as Streptomyces sp. BL93. The antibacterial substance produced by the isolate BL93 had higher affinity for water than butanol and was insoluble in chloroform or ethylacetate. Most of its antibacterial activity was retained even after heating at 100℃ for 30min and was stable at pH ranges 3 to 9. As the isolate BL93 was tentatively identified to be Streptomyces violaceus, the antibacterial substance preferentially need to be identified and compared with aspartocin, an antimicrobial compound produced by Streptomyces violaceus.

전치부 반대교합아동의 발음장애에 관한 음향적 연구

박정삼,손동수,이상훈,김진태,한세현,장기택,김종철 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.2

It has widely known for speech problem in patients with malocclusion,but there have been insufficient studies on degrees of serverity.Patients with openbite and CIⅢ malocclusion usually have speech problem.It has widly known that fricative /s/ is pronunciated most abnomally in CIⅢ malocclusion than any other consonant.Therefore 20 childen with anterior crossbite selected for control group.7 sounds such as /사(sa),서(sδ),소(so),수(su),스(sω),시(si),세(se)/ were recorded,and the formants and formants ratio were measured by using Sensimetric Speech Station,which is speech analyzing program in IBM pc. The results were as follows: 1.In anterior crossbite group,F1 of all 7 sounds were significantly higher than normal anterior relationship group(P<0.05). 2.There were no significant difference in F2 between two groups except/소(so),수(su)/(P>0.05). 3.In anterior crossbite group,F2/F1 ratio of all 7 sounds were significantly smaller than normal anterior relationship group(P<0.05). 4.There were no significant difference in accordance with tongue position(P>0.05).

소아에서의 급성 파종성 뇌척수염의 임상적 고찰

조수진,박은애,유은선,김혜순,손세정,서정완,이승주,한후재 이화여자대학교 의과대학 2003 EMJ (Ewha medical journal) Vol.26 No.2

목적: 급성 파종성 뇌척수염은 감염이나 예방 접종 후 발생하는 중추 신경계의 급성 자가 면역 염증성 질환으로 탈수초를 일으킨다. 신경학적인 증상으로 발현되고 대부분 환전히 회복되지만 신경학적 후유증을 남기거나 사망 할 수도 있다. 이에 저자들은 본원에서 발생 한 14명을 분석하여 조기 진단과 치료에 도움을 주고자 하였다. 대상과 방법: 1998년 3월부터 2003년 8월까지 이대목동병원에서 급성 파종성 뇌척수염으로 진단 받은 14명의 의무기록을 후향적으로 조사하였다. 결과: 환자들의 평균 발생 연령은 5±7.8개월이였고, 특정계절이나 연도에 집중되어서 나타나지는 않았다. 선행질환은 주로 비특이적인 상기도 감염이 가장 많았고, 초기증상으로는 경련이 가장 많았다. 그 외에 의식저하나 운동장애도 있었다. 뇌척수액 검사에서 백혈구 증가증이 발견된 경우는 있었으나 단백이 증가된 경우는 없었다. 뇌 자기공명 촬영에서 T2 증강시 뇌백질과 기저핵에 고음영의 다발성 병소가 발견되었고 추적 촬영에서 대부분에서 소실되었다. 뇌파 검사가 시행되었던 경우 전반적인 서파가 가장 많았고 국소적인 극파가 나온 경우도 한 명 있었다. 환자들은 정맥 면역 글로블린과 메틸프레드니졸론으로 치료하였고 치료 시작 후 3~7일내 증상이 호전되었다. 모든 환자를 2달 이상 추적 관찰하였고 항경련제가 지속적으로 필요한 정도의 경련성 질환이 두 명, 신경아교증이 남아잇는 경우가 한 명, 외래에서 다발성 경화증이 의심되는 경우가 한 명 있었다. 결론: 급성 파종성 뇌척수염은 침범 부위에 따라서 다양한 임상 상으로 나타나며 면역 글로블린과 메틸프레드니졸론이 치료에 효과적이였다. 본 연구에서는 대상 환자수가 적어 신경학적 후유증의 위험요소는 밝힐 수는 없으나, 예후는 검사소견과 연관되어 있지는 않았고, 대부분에서 양호하여 완전히 회복되었으나, 신경학적 후유증이 남은 경우도 있었다. Objective:Acute disseminated encephalomyelitis(ADEM) is an acute demyelinating autoimmune inflammatory disease of the central nervous system which develops after infection of vaccination. It may be fatal, and produce a permanent residual static disability or fully recover. We retrospec-tively studied 14 cases to investigate the clinical findings and outcome of ADEM. Methods : 14cases of ADEM diagnosed at Ewha Womans University Mokdong Hospital from 1998 to 2003 were retrospectively reviewed. Results : The age of onset was 5years±7.8 months and no seasonal clustering was found. The time of onset of symptoms was between 3 to 30 days. The preceding events were nonspecific upper respiratory infections in 9 cases, aseptic meningitis in 4 cases, and gastroenteritis in one case..The initial symptoms were seizure, altered consciousness, hemiparesis, fever, headache, and vomiting. Brain MRI showed multifocal high signal intensity lesions on T2 weighted image mainly in the cerebral whith matter, basal ganglia and periventricular white matter. EEG was performed in some cases and showed generalized or focal slow waves and only one case showed focal spikes. Patients were treated with IV globulin and methylprednisolone and the symptoms improved within 3-7 days after treatment. All patients were followed up for more than 2 months and most of them fully recovered except two. Conclusion : ADEM presents in various clinical manifestations depending on its involvement of the brain lesions. Most cases recovered fully but in some cases, residual permanent neurologic sequelae remained.