• Title/Summary/Keyword: Phosphorous paste

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Characterization of Screen Printed phosphorous Diffusion Paste for Silicon Solar Cells (스크린 프린팅을 이용한 태양전지 에미터 형성에 관한 연구)

  • Gong, Dae-Yeong;Yang, Doo-Hwan;Kim, Sun-Yong;Lee, Yong-Woo;Kwon, Tae-Young;Yun, Seog-Woo;Lee, Kwang-Il;Yi, Jun-Sin
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.111-113
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    • 2009
  • This paper shows that you can achieve high quality N+ emitter layers using a screen printable phosphorous diffusion paste and firing in an infrared belt furnace. Spreading resistance measurement from a beveled sample is used to measure carrier concentration as a function of depth for different phosphorous concentrations. Contours of estimated sheet resistance are shown for different processing conditions. This paper describes newly developed low cost phosphorous pastes. It shows the characterization of the newly developed phosphorous paste (DP99-038). This low cost pastes can easily be printed and make 16% efficiency.

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Crystalline Silicon Solar Cell with Selective Emitter Using One-step Diffusion Process (One-step diffusion으로 형성된 선택적 에미터 결정질 실리콘 태양전지에 관한 연구)

  • Jeong, Kyeong-Taek;Yang, O-Bong;Yu, Gwon-Jong;Lee, Jeong-Chul;Song, Hee-Eun
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.40-44
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    • 2011
  • Recent studies in crystalline silicon solar cell fabrication have been focused on high efficiency and low cost. However, the rising of the cost results in additional processes to approach high efficiency. The fabrication process also becomes complicated with additional technologies. In this paper, we studied the selective emitter formation with phosphorous paste to improve the conversion efficiency. Selective emitter formations like two-step diffusion or etch-back method require at least one more step compared in the conventional line since heavily and lightly doped area was needed to form separately.However,one-step diffusion process is the method diffusing heavily and lightly doped area at the same time only with additional screen-printing step. This study lays the foundation for the simple way to form the selective emitter.

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Physical-chemical Properties and Phosphorus Adsorption Characteristics of Soils in Baicheng, China (중국 길림성 백성지역 흑개토의 이화학성 및 인산 흡착 특성)

  • Jin, Sheng-Ai;Lee, Sang-Mo;Choi, Woo-Jung;Yoo, Sun-Ho
    • Applied Biological Chemistry
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    • v.44 no.2
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    • pp.92-96
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    • 2001
  • Soil physical-chemical properties and phosphorous adsorption characteristics were investigated to obtain the informations of the appropriate fertilization and soil management in Baicheng region, China, where agricultural circumstances at present forces to consider the use of land for crop production. Soils were collected from one uncultivated and three cultivated lands on August 1993. Soil $_PH$ was very higher in uncultivated land than in cultivated land, their values were 10.2 and 7.4, respectively. Regardless of cultivation, soil organic matter contents were below 2%, and concentrations of available soil phosphorus expressed as Bray 1 P and Olson P were less than 10 mg P $kg^{-1}$, however, cation exchange capacity was higher than 20 cmol(+) $kg^{-1}$. For uncultivated soil, the values of exchangeable sodium percent and calcium saturation percent were higher than 100%. The major cation of soil saturation paste extracts was Na regardless of land use type. Based on electrical conductivity and sodium adsorption ratio of saturation paste extracts, uncultivated soil was classified as saline-sodic soil and cultivated soil was classified as sodic or normal soil. The maximum adsorption capacity of phosphorus calculated by Langmuir isotherm ranged from 406 to 521 mg P ,$kg^{-1}$. The constraints of soils in Baicheng regions for agricultural cops werw high salt concentration, unfavorable soil chemical composition such as low concentration of available phosphorous, and poor drainage due to soil dispersion by high Na concentration. Therefore, the soil in Baicheng region, need the application of phosphorus fertilizer to increase the soil fertility and the proper soil management to improve the soil physical property especially permeability and soil structure.

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REMINERALIZATION DEPTH OF CPP-ACP ON DEMINERALIZATION HUMAN ENAMEL IN VITRO (탈회된 법랑질에서 CPP-ACP의 재광화 깊이)

  • Choi, Han-Ju;Choi, Yeong-Chul;Kim, Kwang-Chul;Choi, Sung-Chul
    • Journal of the korean academy of Pediatric Dentistry
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    • v.35 no.2
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    • pp.278-286
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    • 2008
  • Many studies regarding Casein phosphopeptides-amorphous calcium phosphate(CPP-ACP) have demonstrated the remineralization ability on the demineralized enamel surface. A question is still remained that how deep can the calcium (Ca) and phosphorus (P) ions supplied by the CPP-ACP paste penetrate into the enamel subsurface. The aims of this study were to measure the penetrating depth of Ca and P ions in the demineralized human enamel in vitro, and were to determine the amount and depth of Ca and P ions according to the duration. The amount and depth of Ca and P ions were measured by microscopic observation with Field Emission Scanning Electron Microscopy (FE-SEM; LEO SUPRA 55, Carl Zeiss, Germany) and Energy Dispersive X-ray Spectrometer (EDS; GENESIS 2000, EDAX, USA: Linescan of Calcium and Phosphorus). Freshly extracted four human 1st premolars were obtained from the Dept. of Pediatric Dent., Kyung Hee Univ. Buccal surfaces of the 1st premolars were covered with nail varnish to form a window on the middle third of buccal surface. All of the teeth with enamel windows were immersed in a solution of 0.1 M lactic acid, Carbopol C907 (carboxypolymethylene BF Goodrich, Cleveland, OH, USA) at pH 4.8, and then incubated for 7 days. Each tooth crown was sawn in half through the midline of buccal window along the long axis of premolar. The four blocks of premolars were immersed in a 10-times diluted solution of CPP-ACP paste (Tooth Mousse, GC Corp., Tokyo, Japan) for 1, 2, 3 and 5 weeks while the rests were immersed in a placebo solution (distilled water) for the same duration. Each specimen was embedded in epoxy resin, and was sectioned perpendicular to the window, using a water-cooled diamond blade saw. The spectrum density indices of Ca and P were measured in the sound, de- and remineralized enamels by FE-SEM and EDS. The Student's t test was performed to compare the Spectrum Density Indices (SDI) of sound, re-and demineralized enamels, and to compare the differences among the durations. Followings are the conclusion : 1. The penetration depth of the remineralizing ions (Ca & P) of CPP-ACP paste is related to the depth of demineralized enamel (approximately $1050{\sim}1350{\mu}m$). It is revealed that the penetration depth of both ions reaches full thickness of decalcification and even slightly into the sound enamel. 2. The Ca & P levels of remineralized enamels in 1, 2 weeks were significantly higher than those of the sound enamels (p<0.05). 3. No statistically significant difference of Ca & P levels was found in relation with the increasing duration of remineralization (p>0.05).

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Study on Energy and Nutrient Intake and Food Preference of the Elderly in Care Facilities (요양시설 거주 노인의 에너지와 영양소 섭취 실태 및 식품선호도 조사)

  • Kwon, Jong-Sook;Lee, Seung Hee;Lee, Kang Min;Lee, Yoonna
    • Korean Journal of Community Nutrition
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    • v.21 no.2
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    • pp.200-217
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    • 2016
  • Objectives: The purpose of this study was to assess energy and nutritional intake and investigate the preference for food and cooking methods of the residents in elderly care facilities. Methods: Data were collected from 72 residents (10 males and 62 females) aged ${\geq}70$ years in elderly care facilities using questionnaires, food photographs for estimating dietary intake and records for daily physical activity. Results: Average age of the study participants was 85.0 years and 41, 36 and 8 had dementia, hypertension and diabetes mellitus, respectively. 15%, 65% and 19% of subjects were physically mobile, enervated, and immobile, respectively. Daily energy intake was 1360.2 kcal in men and 1378.0 kcal in women, which were 68.0% and 86.1% of the estimated energy requirement (EER) of dietary reference intake for Koreans (KDRI) for ${\geq}75$ year old individuals, respectively. Estimated energy expenditure (EEE) of subjects calculated using formula from KDRI was 1361.9 kcal and EER calculated using estimated daily physical activity (EDPA) was 1232.9 kcal. Energy intake and EEE from KDRI were higher than EER from EDPA. Dietary intake of dietary fiber, calcium, potassium, zinc, vitamin $B_2$, niacin, vitamin C were lower, and protein, phosphorous, iron, sodium, vitamin A, vitamin $B_1$, vitamin $B_6$, vitamin E were higher than the corresponding ones of KDRI. Subjects liked meats, fishes and shellfish, and fruits, while subjects disliked milk, seaweeds and salted fish and salted vegetables. Cooked rice, soybean paste soup, beef, cooked sliced radish strip, and yogurt were favorite foods, with steam being a favorite cooking method. Subjects considered nutrition as the most important factor for improving food service quality. Conclusions: Results of this study could be utilized for improving food-service for the residents in elderly care facilities, and provide a basis for setting reference intake of energy and nutrients of the elderly having very low activity levels.