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>

양성 발작성 체위성 현훈의 전정재활치료 결과에 영향을 미치는 요인분석

전형규,송세호,한규철,허진명 대한이비인후과학회 2001 대한이비인후과학회지 두경부외과학 Vol.44 No.12

참치 뼈를 이용한 Hydroxyapatite 세라믹 복합체의 합성 및 생체 친화성(제3보) : 인공체액에서의 Hydroxyapatite 세라믹 복합체간의 결합의 전자현미경 관찰 SEM Photographs of Bonding Properties between Hydroxyapatite Ceramics Composites in the Simulated Body Fluid

김세권,최진삼,이창국,변희국,전유진,이응호,박인용 대전산업대학교 반도체기술연구소 1999 半導體技術硏究所報 Vol.1 No.-

참치 뼈에서 추출한 hydroxyapatite를 출발물질로 여러 가지 세라믹 복합체를 제조하여 인공체액에서의 hydroxyapatite 복합체간의 화학결합을 조사하였다. hydroxyapatite 복합체들은 인공체액에서 4주 후부터 화학 결합성질을 나타내었다. 결합강도는 bioglass가 가장 강하게 나타났으며, 조성에 따른 의존성은 관찰할 수 없었다. 인공체액에서 복합체들은 이들의 경계면에서 불균일 핵생성 및 성장에 의해 화학적 결합으로 이루어졌다. Chemical bonding was investigated in the simulated body fluid of several selected hydroxyapatite-containing composites. The hydroxyapatite-containing composites chemically bonded with each other in the simulated body fluid after 4 weeks. Bioglass was strongly bonded in the simulated body fluid, but bonding strength was not depended on composition. Their composite bodies were chemically bonded by heterogeneous nucleation and growth at the interfaces of the specimens in the simulated body fluid.

光波長이 오이(Cucumis sativus L.) 플러그苗의 生長에 미치는 影響

용영록,전지영,황세진,김일섭,정천순 강릉대학교 동해안지역연구소 2000 東海岸硏究 Vol.11 No.1

This research was carried to find out the optimum artificial light condition for plug seedling production of high quality cucumber through investigating growth response of the seedling by both light wave length and treatment period. The treatment with blue and red fluorescent lamp increased the fresh weight involving hypocotyl and root and controlled the elongation of hypocotyl, compared with other treatments. The 30-day-old seedling treatment with blue and red light for 12 hours showed that vegetative growth including root, stem and leaves was better than that of seedling treated with other lamps. Seedling under blue and red light for 12 hours grew 60.0mm and 0.55g in length and weight of hypocotyl. respectively, Hypocotyl length and weight were 44.9mm and 0.62g when seedling was grown under above light condition for 6 hours. Total chlorophyll contents of hypocotyl were highest in the light mixing treatment, and this accelerated greening. Morphological characteristics by investigating cross and longitudinal section of 30-day-old cucumber seedling treated with the mixing fluorescent lamps indicated that epidrmis tissues were usually single layer and thicker, resulting in small, compact and non-intercellular spaces of cells. On the other hand, epidermis tissues of the control composed of large, longer and round cells and cortex tissues showed large intercellular spaces between cells. Longitudinal section of photo-treated hypocotyl showed that there were more shorter cells and non-intercellular spaces of cells than untreated tissues. As a result, blue and red light mixing treatment controled the cell elongation of seedling hypocotyl, resulting in shortening hypocotyl of cucumber seedling.

새로운 HVT 성장방법을 이용한 CIGS 결정성장

이강석,전헌수,이아름,정세교,배선민,조동완,옥진은,김경화,양민,이삼녕,안형수,배종성,하홍주,Lee, Gang-Seok,Jeon, Hun-Soo,Lee, Ah-Reum,Jung, Se-Gyo,Bae, Seon-Min,Jo, Dong-Wan,Ok, Jin-Eun,Kim, Kyung-Hwa,Yang, Min,Yi, Sam-Nyeong,Ahn, Hyung-Soo 한국결정성장학회 2010 한국결정성장학회지 Vol.20 No.3

높은 광흡수 계수를$(1{\times}10^5cm^{-1})$ 가지는 CIGS는 Ga의 비율에 따라서 밴드갭을 조절할 수 있다는 장점을 지니고 있다. CIGS의 밴드갭은 Ga의 비율에 따라 $CuInSe_2$(Eg: 1.0 eV)에서 $CuGaSe_2$(Eg: 1.68 eV)까지의 범위에 존재하며, 태양전지에 서 이상적인 fill factor 모양을 가지도록 Ga의 비율을 높게 조성한다. CIGS 흡수층을 제작하는 방법에는 co-evaporator 방식이 가장 널리 사용되며 연구되고 있다. 이에 본 연구에서는 수평 형태의 hydride vapor transport (HVT)법을 고안하여 CIGS 나노 구조 및 에피성장을 시도하였다. HVT법은 $N_2$ 분위기에서 원료부의 CIGS 혼합물을 HCl과 반응시켜 염화물 기체상태로 변환 후 growth zone까지 이동하여 성장을 하는 방식이다. 성장기판은 c-$Al_2O_3$ 기판과 u-GaN을 사용하였다. 성장 후 field emission scanning electron microscopy(FE-SEM)과 energy dispersive spectrometer(EDS)를 이용하여 관찰하였다. The Cu$(In_{1-x}Ga_x)Se_2$ is the absorber material for thin film solar cell with high absorption coefficient of $1{\times}10^5cm^{-1}$. In the case of CIGS, the movable energy band gap from $CuInSe_2$ (1.00 eV) to $CuGaSe_2$ (1.68 eV) can be acquired while controlling Ga contain ratio. Generally, the co-evaporator method have used for development and fabrication of the CIGS absorption layer. However, this method should need many steps and lengthy deposition time with high temperature. For these reasons, in this paper, a new growth method of CIGS layer was attempted to hydride vapor transport (HVT) method. The CIGS mixed-source material reacted for HCl gas in the source zone was deposited on the substrate after transporting to growth zone. c-plane $Al_2O_3$ and undoped GaN were used as substrates for growth. The characteristics of grown samples were measured from SEM and EDS.

Prediction of calcium and phosphorus requirements for pigs in different bodyweight ranges using a meta-analysis

( Se Min Jeon ),( Abdolreza Hosseindoust ),( Sang Hun Ha ),( Tae Gyun Kim ),( Jun Young Mun ),( Joseph Moturi ),( Suhyup Lee ),( Yo Han Choi ),( Sang Deok Lee ),( Soo Jin Sa ),( Jin Soo Kim ) 한국축산학회(구 한국동물자원과학회) 2021 한국축산학회지 Vol.63 No.4

Several studies have focused on Ca and P requirements for pigs. These requirements are estimated from their retention and bone formation. However, modern pig breeds have different responses to dietary Ca and P than traditional breeds, and their requirements are expected to change on an annual basis. Besides individual Ca and P needs, the Ca to P ratio (Ca/ P) is an important factor in determining requirements. This study aimed to implement a linear and quadratic regression analysis to estimate Ca and P requirements based on average daily gain (ADG), apparent total tract digestibility (ATTD) of Ca (ATTD-Ca), ATTD of P (ATTD-P), and crude protein (CP) digestibility. Results show that Ca/P had linear and quadratic effects on ADG in the phytase-supplemented (PS) group in both the 6-11 kg and 11-25 kg categories. In the latter category, the CP digestibility was linearly increased in response to increasing Ca/P in the without-phytase (WP) group. In the 25-50 kg category, there was a linear response of ADG and linear and quadratic responses of CP digestibility to Ca/P in the PS group, while a linear and quadratic increase in CP digestibility and a quadratic effect on ATTD-Ca were observed in the WP group. In the 50-75 kg category, Ca/P had significant quadratic effects on ADG in the PS and WP groups, along with significant linear and quadratic effects on ATTD-Ca. In addition, Ca/P had significant quadratic effects on ATTD-P and led to a significant linear and quadratic increase in the CP digestibility in the WP group. In the 75-100 kg category, analysis showed a significant decrease in ATTD-Ca and ATTD-P in the PS and WP groups; in the latter, ATTD-P and ATTD-Ca were linearly decreased by increasing Ca/P. In conclusion, our equations predicted a higher Ca/P in the 6-25 kg bodyweight categories and a lower Ca/P in the 50-100 kg category than that recommended in the literature.

Risk factors for transmission in a COVID-19 cluster infection in a high school in the Republic of Korea

Jeon Jin-Hwan,Su Jin Kang,Jeong Se-Jin,Hyeon-Cheol Jang,Park Young Joon,이상은 질병관리본부 2023 Osong Public Health and Research Persptectives Vol.14 No.4

Objectives: This study aimed to examine the scale, characteristics, risk factors, and modes of transmission in a coronavirus disease 2019 (COVID-19) outbreak at a high school in Seoul, Republic of Korea.Methods: An epidemiological survey was conducted of 1,118 confirmed cases and close contacts from a COVID-19 outbreak at an educational facility starting on May 31, 2021. In-depth interviews, online questionnaires, flow evaluations, and CCTV analyses were used to devise infection prevention measures. Behavioral and spatial risk factors were identified, and statistical significance was tested.Results: Among 3rd-year students, there were 33 confirmed COVID-19 cases (9.6%). Students who used a study room in the annex building showed a statistically significant 4.3-fold elevation in their relative risk for infection compared to those who did not use the study room. Moreover, CCTV facial recognition analysis confirmed that 17.8% of 3rd-year students did not wear masks and had the lowest percentage of mask-wearers by grade. The air epidemiological survey conducted in the study room in the annex, which met the 3 criteria for a closed space, confirmed that there was only 10% natural ventilation due to the poor ventilation system.Conclusion: To prevent and manage the spread of COVID-19 in educational facilities, advance measures that consider the size, operation, and resources of each school are crucial. In addition, various survey methodologies should be used in future studies to quickly analyze a wider range of data that can inform an evidence-based quarantine response.

Consistent thermal analysis procedure of LNG storage tank

Jeon, Se-Jin,Jin, Byeong-Moo,Kim, Young-Jin,Chung, Chul-Hun Techno-Press 2007 Structural Engineering and Mechanics, An Int'l Jou Vol.25 No.4

As the LNG (Liquefied Natural Gas) tank contains cryogenic liquid, realistic thermal analyses are of a primary importance for a successful design. The structural details of the LNG tank are so complicated that some strategies are necessary to reasonably predict its temperature distribution. The proposed heat transfer model can consider the beneficial effects of insulation layers and a suspended deck on temperature distribution of the outer concrete tank against cryogenic conditions simply by the boundary conditions of the outer tank model. To this aim, the equilibrium condition or heat balance in a steady state is utilized in a various way, and some aspects of heat transfer via conduction, convection and radiation are implemented as necessary. Overall thermal analysis procedures for the LNG tank are revisited to examine some unjustifiable assumptions of conventional analyses. Concrete and insulation properties under cryogenic condition and a reasonable conversion procedure of the temperature-induced nonlinear stress into the section forces are discussed. Numerical examples are presented to verify the proposed schemes in predicting the actual temperature and stress distributions of the tank as affected by the cryogenic LNG for the cases of normal operation and leakage from the inner steel tank. It is expected that the proposed schemes enable a designer to readily detect the effects of insulation layers and a suspended deck and, therefore, can be employed as a useful and consistent tool to evaluate the thermal effect in a design stage of an LNG tank as well as in a detailed analysis.

Positive effects of β-amyrin on pentobarbital-induced sleep in mice via GABAergic neurotransmitter system

Jeon, Se Jin,Park, Ho Jae,Gao, Qingtao,Lee, Hyung Eun,Park, Se Jin,Hong, Eunyoung,Jang, Dae Sik,Shin, Chan Young,Cheong, Jae Hoon,Ryu, Jong Hoon Elsevier 2015 Behavioural brain research Vol.291 No.-

<P><B>Abstract</B></P> <P>Sleep loss, insomnia, is considered a sign of imbalance of physiological rhythm, which can be used as pre-clinic diagnosis of various neuropsychiatric disorders. The aim of the present study is to understand the pharmacological actions of α- or β-amyrin, natural triterpene compound, on the sleep in mice. To analyze the sleeping behavior, we used the well-known pentobarbital-induced sleeping model after single administration of either α- or β-amyrin. The sleeping onset time was remarkably decreased and duration was prolonged by β-amyrin (1, 3, or 10mg/kg) but not by α-amyrin (1, 3, or 10mg/kg). These effects were significantly blocked by GABA<SUB>A</SUB> receptor antagonist, bicuculline. Moreover, β-amyrin increased brain GABA level compared to the vehicle administration. Overall, the present study suggests that β-amyrin would enhance the total sleeping behavior in pentobarbital-induced sleeping model via the activation of GABAergic neurotransmitter system through GABA content in the brain.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Pentobarbital-induced sleeping behavior was prolonged by β-amyrin. </LI> <LI> Increased sleeping behavior was blocked by GABA<SUB>A</SUB> receptor antagonist. </LI> <LI> Brain GABA level was increased by β-amyrin administration. </LI> </UL> </P>

Oleanolic acid ameliorates cognitive dysfunction caused by cholinergic blockade via TrkB-dependent BDNF signaling

Jeon, Se Jin,Lee, Hong Ju,Lee, Hyung Eun,Park, Se Jin,Gwon, Yubeen,Kim, Haneul,Zhang, Jiabao,Shin, Chan Young,Kim, Dong Hyun,Ryu, Jong Hoon Elsevier 2017 NEUROPHARMACOLOGY - Vol.113 No.1

<P><B>Abstract</B></P> <P>Oleanolic acid is a naturally occurring triterpenoid and is widely present in food and medicinal plants. To examine the effect of oleanolic acid on memory deficits, we employed a cholinergic blockade-induced cognitive deficit mouse model. A single administration of oleanolic acid significantly increased the latency on the passive avoidance task and affected the alternation behavior on the Y-maze task and the exploration time on the novel object recognition task, indicating that oleanolic acid reverses the cognitive impairment induced by scopolamine. In accordance with previous reports, oleanolic acid enhanced extracellular-signal-regulated kinase 1/2 <B>(</B>ERK1/2) and cAMP response element-binding protein (CREB) phosphorylation and brain-derived neurotrophic factor (BDNF) expression in the hippocampus. Interestingly, ameliorating effect of oleanolic acid on scopolamine-induced memory impairment was abolished by N2-(2-{[(2-oxoazepan-3-yl)amino]carbonyl}phenyl)benzo[<I>b</I>]thiophene-2-carboxamide (ANA-12), a potent and specific inhibitor of tropomyosin receptor kinase B (TrkB), in the passive avoidance task. Similarly, oleanolic acid significantly evoked long-term potentiation in a dose-dependent manner, which was diminished by ANA-12 treatment as shown in the electrophysiology study. Together, these results imply that oleanolic acid ameliorates scopolamine-induced memory impairment by modulating the BDNF-ERK1/2-CREB pathway through TrkB activation in mice, suggesting that oleanolic acid would be a potential therapeutic agent for the treatment of cognitive deficits.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Oleanolic acid activated the ERK1/2-CREB-BDNF pathway in the hippocampus via TrkB activation. </LI> <LI> Scopolamine-induced memory dysfunction was ameliorated by oleanolic acid treatment. </LI> <LI> Oleanolic acid evoked the long-term potentiation in a dose-dependent manner. </LI> <LI> Oleanolic acid would be a potential therapeutic agent for the cognitive problem. </LI> </UL> </P>