• Title/Summary/Keyword: Pd/Si

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Investigation of Ni/Cu Contact for Crystalline Silicon Solar Cells (결정질 실리콘 태양전지에 적용하기 위한 도금법으로 형성환 Ni/Cu 전극에 관한 연구)

  • Kim, Bum-Ho;Choi, Jun-Young;Lee, Eun-Joo;Lee, Soo-Hong
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.250-253
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    • 2007
  • An evaporated Ti/Pd/Ag contact system is most widely used to make high-efficiency silicon solar cells, however, the system is not cost effective due to expensive materials and vacuum techniques. Commercial solar cells with screen-printed contacts formed by using Ag paste suffer from a low fill factor and a high shading loss because of high contact resistance and low aspect ratio. Low-cost Ni and Cu metal contacts have been formed by using electroless plating and electroplating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Ni/Cu alloy is plated on a silicon substrate by electro-deposition of the alloy from an acetate electrolyte solution, and nickel-silicide formation at the interface between the silicon and the nickel enhances stability and reduces the contact resistance. It was, therefore, found that nickel-silicide was suitable for high-efficiency solar cell applications. The Ni contact was formed on the front grid pattern by electroless plating followed by anneal ing at $380{\sim}400^{\circ}C$ for $15{\sim}30$ min at $N_{2}$ gas to allow formation of a nickel-silicide in a tube furnace or a rapid thermal processing(RTP) chamber because nickel is transformed to NiSi at $380{\sim}400^{\circ}C$. The Ni plating solution is composed of a mixture of $NiCl_{2}$ as a main nickel source. Cu was electroplated on the Ni layer by using a light induced plating method. The Cu electroplating solution was made up of a commercially available acid sulfate bath and additives to reduce the stress of the copper layer. The Ni/Cu contact was found to be well suited for high-efficiency solar cells and was successfully formed by using electroless plating and electroplating, which are more cost effective than vacuum evaporation. In this paper, we investigated low-cost Ni/Cu contact formation by electroless and electroplating for crystalline silicon solar cells.

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Smads, p38 and ERK1/2 are involved in BMP9-induced osteogenic differentiation of C3H10T1/2 mesenchymal stem cells

  • Xu, Dao-Jing;Zhao, Ying-Ze;Wang, Jin;He, Juan-Wen;Weng, Ya-Guang;Luo, Jin-Yong
    • BMB Reports
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    • v.45 no.4
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    • pp.247-252
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    • 2012
  • Although previous studies have demonstrated that BMP9 is highly capable of inducing osteogenic differentiation of mesenchymal stem cells, the molecular mechanism involved remains to be fully elucidated. In this study, we showed that BMP9 simultaneously promotes the activation of Smad1/5/8, p38 and ERK1/2 in C3H10T1/2 cells. Knockdown of Smad4 with RNA interference reduced nuclear translocation of Smad1/5/8, and disrupted BMP9-induced osteogenic differentiation. BMP9-induced osteogenic differentiation was blocked by p38 inhibitor SB203580, whereas enhanced by ERK1/2 inhibitor PD98059. SB203580 decreased BMP9-activated Smads singling, and yet PD98059 stimulated Smads singling in C3H10T1/2 cells. The effects of inhibitor were reproduced with adenovirus expressing siRNA targeted p38 and ERK1/2, respectively. Taken together, our findings revealed that Smads, p38 and ERK1/2 are involved in BMP9-induced osteogenic differentiation. Also, it is noteworthy that p38 and ERK1/2 may play opposing regulatory roles in mediating BMP9-induced osteogenic differentiation of C3H10T1/2 cells.

Induced Pluripotent Stem Cell Generation using Nonviral Vector

  • Park, Si-Jun;Shin, Mi-Jung;Seo, Byoung-Boo;Park, Hum-Dai;Yoon, Du-Hak;Ryoo, Zae-Young
    • Reproductive and Developmental Biology
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    • v.35 no.4
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    • pp.449-455
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    • 2011
  • Induced pluripotent stem (iPS) cells have been generated from mouse and human somatic cells by etopic expression of transcription factors. iPS cells are indistinguishable from ES cells in terms of morphology and stem cell marker expression. Moreover, mouse iPS cells give rise to chimeric mice that are competent for germline transmission. However, mice derived from iPS cells often develop tumors. Furthermore, the low efficiency of iPS cell generation is a big disadvantage for mechanistic studies. Nonviral plasmid.based vectors are free of many of the drawbacks that constrain viral vectors. The histone deacetylase inhibitor valproic acid (VPA) has been shown to improve the efficiency of mouse and human iPS cell generation, and vitamin C (Vc) accelerates gene expression changes and establishment of the fully reprogrammed state. The MEK inhibitor PD0325901 (Stemgent) has been shown to increase the efficiency of the reprogramming of human primary fibroblasts into iPS cells. In this report, we described the generation of mouse iPS cells devoid of exogenous DNA by the simple transient transfection of a nonviral vector carrying 2A-peptide-linked reprogramming factors. We used VPA, Vc, and the MEK inhibitor PD0325901 to increase the reprogramming efficiency. The reprogrammed somatic cells expressed pluripotency markers and formed EBs.

A Study of the Correlation Between the Siblings Relation and the Personality Characteristics on the Oriental Medical University Students by MMPI Profiling (MMPI 척도로 본 한의대생의 형제자매관계와 성격특성의 연관성에 관한 연구)

  • Ha, Ji-Won;Jung, Jin-Heong;Kim, Bo-Kyung
    • Journal of Oriental Neuropsychiatry
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    • v.23 no.4
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    • pp.123-132
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    • 2012
  • Objectives : This study aims to investigate the correlation between the characteristics of personality on MMPI scale, and the siblings relation, number of current family living with, gender and age of the Oriental Medical University students. Methods : For this study, we carried out the MMPI profiling and gathered information regarding the sibling relation of the subjects. We studied the correlation between the two measures, and the correlation between MMPI scales and the subjects' gender and age. Results : 1. The group without siblings had higher STY figures then the groups with siblings. 2. There was no significant differences in MMPI profiles among the only child group, first-born group, second-born group, and third-born group. 3. The married group showed higher Pd, Pt, Sc, BDL figures than the unmarried group. 4. As the number of family members currently living with increased, the BDL and STY figures decreased. 5. The male group had higher Hs, Hy, Pa, Ma, NAR, BDL, ANT, CPS, PAR, and SZD figures, while the female group had higher D, Pd, Mf, Pt, HST, PAG, and DEP figures. 6. As the subjects' age increased, the figure of Hs, D, Pt, Sc, Si, AVD, and SZD increased, while the HST figure decreased. Conclusions : By the above results, we can assume that the sibling relations and the order one is born in the family does not affect one's personality much in grown-ups; whereas the gender and age affect the personality.

The Effects of Entertainment Producer and Writer Job Stress Factors on Stress Level and Depression (예능 PD, 예능 작가의 직무스트레스요인이 스트레스 수준 및 우울에 미치는 영향)

  • Ryu, Si-Nae;Koo, Jung-Wan
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.29 no.1
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    • pp.108-118
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    • 2019
  • Objective: The purpose of this study was to investigate the effects of occupational stress factors on the level of stress and depression of entertainment program producers and entertainment program writers. Methods: This study was based on analysis of a survey collected by 65 respondents out of 224 questionnaires who are entertainment program PDs and entertainment program writers. The survey was conducted from December 20, 2017 to February 20, 2018. Results: In the logistic regression analysis conducted to investigate the factors affecting the stress level in the job-related characteristics of a) higher total career, b) shorter working period in the current firm, c) longer weekly working hours and d) more count of weekend work, the results found higher stress levels. In the sub-factors of job stress, the stress level encountered by respondents was significantly higher for those with a) higher job demand, b) lower insufficient job control and c) higher job instability. In the logistic regression analysis conducted to investigate the factors affecting depression, the depression level in entertainment PD was higher than the entertainment writer in the sociodemographic characteristics. In the sub-factors of job stress, the stress level was significantly higher for those with higher job demand, lower insufficient job control, and higher job instability. For job-related characteristics, depression was significantly higher for longer weekly working hours. Conclusions: Entertainment program producers and entertainment program writers suffer from psychosocial stress and depression which are caused by excessive job demands, lack of job autonomy and job instabilities. Those factors must be managed and also their workweek should be shortened.

Some hair mineral contents of non-violent criminal and normal control (건강인(健康人)과 비폭력(非暴力) 범죄자(犯罪者)의 두발(頭髮)중 일부 금속원소(金屬元素) 함량(含量))

  • Hong, Sung-Cheul;Kim, Doo-Hie
    • Journal of Preventive Medicine and Public Health
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    • v.26 no.1 s.41
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    • pp.110-125
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    • 1993
  • This study was designed to determine whether non-violent criminal and normal control on the basis of concentration of levels of trace mineral and toxic metal by analysis of human scalp hair. The subjects were selected 87 nonviolent criminal from a prison population and 120 normal control from periodic health checks for study. Hair samples were taken from the napes and Minnesota Multiple Personality Inventory (MMPI) was performed also. Five trace mineral (Zn, Cu, Mg, Fe, Na) and two toxic metal (lead, cadmium) contents were determined by an atomic absorption spectrometer. The contents of zinc and magnesium in hair of non-violent criminal were significantly lower than the control group (p<0.01). In the case of lead and cadimum, mean value of criminal group was significantly higher than control group. Significantly higher T-score of MMPI was seen in non-violent criminal group fur psychopathic deviate (Pd), paranoia scale (Pa), and Mania scale (Ma) than control group, but T-score of depression scale (D) was significantly higher in the control group. In the non-violent criminal group, the content of copper inversely proportion to T-score of Hs, D, Hy, Pd, Mf, Pa, Pt, Sc, Si except Ma, also Zinc inversely proportion to T-score of Hy, Mf, Pa, Pt. These results suggest that difference of some hair mineral contents exist between criminal and normal control group. Thus further studies are necessary to determine whether violent and nonviolent criminal group attributed biochemical imbalance with carefully constructed and controlled studies.

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Investigation on Growth Characteristic of ZnO Nanostructure with Various O2 Pressures by Thermal Evaporation Process (열증착법으로 성장된 ZnO 나노구조물의 산소유량 변화에 대한 성장 변화)

  • Kim, Kyoung-Bum;Jang, Yong-Ho;Kim, Chang-Il;Jeong, Young-Hun;Lee, Young-Jin;Jo, Jeong-Ho;Paik, Jong-Hoo;Nahm, Sahn
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.10
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    • pp.839-843
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    • 2011
  • ZnO nanostructures were developed on a Si (100) substrate from powder mixture of ZnO and 5 mol% Pd (ZP-5) as reactants by ${\times}$ sccm oxygen pressures(x= 0, 10, 20, 40). DTA (differential thermal analysis) result shows the Pd(5 mol%)+ZnO mixtured powder(PZ-5) is easily evaporated than pure ZnO powder. The PZ-5 mixtured powder was characterized by DTA to determine the thermal decomposition which was found to be at $800^{\circ}C$, $1,100^{\circ}C$. Weight loss(%) and ICP (inductively coupled plasma) analysis reveal that Zn vaporization is decreased by increased oxygen pressures from the PZ-5 at $1,100^{\circ}C$ for 30 mins. Needle-like ZnO nanostructures array developed from 10 sccm oxygen pressure, was well aligned vertically on the Si substrate at $1,100^{\circ}C$ for 30 mins. The lengths of the Needle-like ZnO nanostructures is about 2 ${\mu}m$ with diameters of about 65 nm. The developed ZnO nanostructures exhibited growth direction along [001] with defect-free high crystallinity. It is considered that Zn vaporization is responsible for the growth of Needle-like ZnO nanostructures by controlling the oxygen pressures. The photoluminescence spectra of ZnO nanostructures exhibited stronger 376.7 nm NBE (near band-edge emission) peak and 529.3 nm DLE (deep level energy) peak.

Insulin Like Growth Factor Binding Protein-5 Regulates Excessive Vascular Smooth Muscle Cell Proliferation in Spontaneously Hypertensive Rats via ERK 1/2 Phosphorylation

  • Lee, Dong Hyup;Kim, Jung Eun;Kang, Young Jin
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.2
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    • pp.157-162
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    • 2013
  • Insulin-like growth factor binding proteins (IGFBPs) are important components of insulin growth factor (IGF) signaling pathways. One of the binding proteins, IGFBP-5, enhances the actions of IGF-1, which include the enhanced proliferation of smooth muscle cells. In the present study, we examined the expression and the biological effects of IGFBP-5 in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). The levels of IGFBP-5 mRNA and protein were found to be higher in the VSMC from SHR than in those from WKY. Treatment with recombinant IGFBP-5-stimulated VSMC proliferation in WKY to the levels observed in SHR. In the VSMCs of WKY, incubation with angiotensin (Ang) II or IGF-1 dose dependently increased IGFBP-5 protein levels. Transfection with IGFBP-5 siRNA reduced VSMC proliferation in SHR to the levels exhibited in WKY. In addition, recombinant IGFBP-5 significantly up-regulated ERK1/2 phosphorylation in the VSMCs of WKY as much as those of SHR. Concurrent treatment with the MEK1/2 inhibitors, PD98059 or U0126 completely inhibited recombinant IGFBP-5-induced VSMC proliferation in WKY, while concurrent treatment with the phosphatidylinositol-3 kinase inhibitor, LY294002, had no effect. Furthermore, knockdown with IGFBP-5 siRNA inhibited ERK1/2 phosphorylation in VSMC of SHR. These results suggest that IGFBP-5 plays a role in the regulation of VSMC proliferation via ERK1/2 MAPK signaling in hypertensive rats.

A SiGe HBT of Current Gain Modulation By using Passivation Ledge (Passivation Ledge를 이용한 SiGe HBT의 Current Gain Modulation)

  • You, Byoung-Sung;Cho, Hee-Yup;Ku, Youn-Seo;Ahn, Chul
    • Proceedings of the IEEK Conference
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    • 2003.07b
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    • pp.771-774
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    • 2003
  • Passivation Ledge's device is taken possession on one-side to the Emitter in this Paper. contact used in this paper Pt as Passivation Ledge of device to use Schottky Diode which has leitmotif, It is accomplished Current Modulation that we wish to do purpose using this device. Space Charge acts as single device which is becoming Passivation to know this phenomenon. This device becomes floating as well as Punched-through. V$_{L}$ (Voltage for Ledge) = - 0.5V ~ 0.5V variable values , PD(Partially Depleted ; Λ>0), as seeing FD(Fully Depleted ; A = 0) maximum electric current gains and Gummel Plot of I-V characteristics (V$_{L}$ = 0.1/ V$_{L}$ = -0.1 ). Becomming Degradation under more than V$_{L}$ = 0.1 , less than V$_{L}$ =-0.05 and Maximum Gain(=98.617076 A/A) value in the condition V$_{L}$ = 0.1. A Change of Modulation is electric current gains by using Schottky Diode and Extrinsic Base PN Diode of Passivation Ledge to Emitter Depletion Layer in HBT of Gummel-Poon I-V characteristics and the RF wide-band electric current gains change the Modulation of CE(Common-Emitter) amplifier description, and it had accomplished Current Gain Modulation by Ledge Bias that change in high frequency and wide bands. wide bands.s.

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Reevaluation of Photon Activation Yields of 11C, 13N, and 15O for the Estimation of Activity in Gas and Water Induced by the Operation of Electron Accelerators for Medical Use

  • Masumoto, Kazuyoshi;Matsumura, Hiroshi;Kosako, Kazuaki;Bessho, Kotaro;Toyoda, Akihiro
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.286-290
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    • 2016
  • Background: Activation of air and water in the electron linear accelerator for medical use has not been considered severely. By the new Japanese regulation for protection of radiation hazard, it became indispensable to evaluate of activation of air and water in the accelerator room. The measurement of induced activity in air and water components in the electron energy region of 10 to 20 MeV is very difficult, because this energy region is close to the threshold energy region of photonuclear reactions. Then, we measured the photonuclear reaction yields of $^{13}N$, $^{15}O$, and $^{11}C$ by using the electron linear accelerator. Obtained data were compared with the data calculated by the Monte Carlo method. Materials and Methods: An activation experiment was performed at the Research Center for Electron Photon Science, Tohoku University. Highly purified $SiO_2$, $Si_3N_4$, and carbon disks were irradiated for 10 minutes by bremsstrahlung converted by a tungsten plate. Induced activity from C, N, and O was obtained. Monte Carlo calculation was performed using MCNP5 and AERY (DCHAIN-SP) to simulate the experimental condition. Cross section data were adopted the KAERI dataset. Results and Discussion: In our experiment in hospital, calculated values were not agreed with experimental values. It might be three possible reasons as the cause of this deference, such as irradiation energy, calculation procedure and cross section data. Obtained data of this work, calculated and experimental values were good agreement with each other within one order. In this work, we used KAERI dataset of photonuclear reaction instead of JENDL. Therefore, it was found that the photonuclear cross section data of light elements are most important for yield calculation in these reactions. Conclusion: Further improvement for calculation using a new dataset JENDL/PD-2015 and considering electron energy spreading will be needed.