• 제목/요약/키워드: large area synthesis

검색결과 168건 처리시간 0.028초

국내 펜트하우스(하늘채)의 공간 특성에 관한 연구 - 서울에 위치한 펜트하우스의 평면 계획 분석을 중심으로 - (A Study on the Characteristics of Penthouse Apartmaent Planning in Korea - Focus on the case analysis of penthouse in Seoul -)

  • 최광민;허범팔
    • 한국실내디자인학회논문집
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    • 제20권3호
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    • pp.172-181
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    • 2011
  • Many of penthouse apartments began to be built and distributed in Korea from the 2000s. However, we have a transformed definition from the international concept of penthouse. It seems that the penthouse apartments in Korea have a confined definition as a luxury and privileged house-we often find it out from advertisements of newly built apartments. In this thesis, therefore, it needs to make a clear and substantial definition of penthouse. And on the base of this definition, this study is intended to analyze planes of penthouse apartments which are distributed recently. It is in order to find out positive aspects of penthouse apartments and to make practical application of this analysis. The process of this study for plane-planning is as follows. Firstly, it is investigated and analyzed that external factors that have an effect on plane-planning such as locations and types of penthouse apartments. Secondly, an interior of penthouse apartments are divided into a private, public and outward area. And properties of each area through this research show the way of division and arrangement of plane. Thirdly, methods of connection between spaces is analyzed on the base of results of research for the way of partition. Finally, specific characters of penthouse apartments planning is derived from synthesis of research. In conclusion, analysis of plane-planning of penthouse apartments is summarized as follows. The majority of penthouse apartments is arranged to small portions of households and on higher stories in apartment which is situated around Han River or public parks. These external factors influence the plane-planning in both the interior and exterior way. For the exterior planning in space, it becomes important to design bays as many as possible in contact with outside in order to satisfy demands for fine prospects. It is also important to plan extra places naturally such as a terrace in order to provide virtual grounding. In the interior planning, a large size of interior induces to develop space for linking between each area, such as corridors or extra rooms. This makes it possible that the private area is linked to each other, at the same time it has its own distinctiveness according to its usage.

A New Strategy to Fabricate a Colloidal Array Templated $TiO_2$ Photoelectrode for Dye-sensitized Solar Cells

  • 이현정
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2011년도 춘계학술발표대회
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    • pp.8.1-8.1
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    • 2011
  • Nanocrystalline titanium dioxide ($TiO_2$) materials have been widely used as an electron collector in DSSC. This is required to have an extremely high porosity and surface area such that the dye can be sufficiently adsorbed and be electronically interconnected, resulting in the generation of a high photocurrent within cells. In particular, their geometrical structures and crystalline phase have been extensively investigated as important issues in improving its photovoltaic efficiency. In this study, we present a new strategy to fabricate a photoelectrode having a periodic structured $TiO_2$ film templated from 1D or 3D polystyrene (PS) microspheres array. Monodisperse PS spheres of various radiuses were used for colloidal array on FTO glasses and two types of photoelectrode structures with different $TiO_2$ materials were investigated respectively. One is the igloo-shaped electrode prepared by $TiO_2$ deposition by RF-sputtering onto 2D microsphere-templated substrates. At the interface between the film and substrate, there are voids formed by the decomposition of PS microspheres during the calcination step. These holes might be expected to play the predominant roles as scattering spherical voids to promote a light harvesting effect, a spacious structure for electrolytes with higher viscosity and effective paths for electron transfer. Additionally the nanocrystalline $TiO_2$ phase prepared by the RF-sputtering method was previously reported to improve the electron drift mobility within $TiO_2$ electrodes. This yields solar cells with a cell efficiency of 2.45% or more at AM 1.5 illumination, which is a very remarkable result, considering its $TiO_2$ electrode thickness (<2 ${\mu}m$). This study can be expanded to obtain higher cell efficiency by higher dye loading through the increase of surface area or multi-layered stacking. The other is the inverse opal photonic crystal electrode prepared by titania particles infusion within 3D colloidal arrays. To obtain the enlargement of ordered area and high quality of crystallinity, the synthesis of titania particles coated with a organic thin layer were applied instead of sol-gel process using the $TiO_2$ precursors. They were dispersed so well in most solvents without aggregates and infused successfully within colloidal array structures. This ordered mesoporous structure provides the large surface area leading to the enough adsorption of dye molecules and have an light harvesting effect due to the photonic band gap properties (back-and-forth reflection effects within structures). A major advantage of this colloidal array template method is that the pore size and its distribution within $TiO_2$ photoelectrodes are determined by those of latex beads, which can be controlled easily. These materials may have promising potentials for future applications of membrane, sensor and so on as well as solar cells.

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한국 미취학 아동의 영양성 빈혈에 관한 연구 (A Study on Nutritional Anemia of Pre-school Children in Korea)

  • 채범석;주덕숙
    • Journal of Nutrition and Health
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    • 제4권1호
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    • pp.1-19
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    • 1971
  • Nutritional anemia is an important nutritional problem affecting large population groups in most developing countries. Nutritional anemia is caused by the absence of any dietary essential involed in hemoglobin formation or by poor absorption of these dietary components. The most likely causes are lack of dietary iron, and folate, vitamin $B_{12}$ and high qualify protein. Anemia is considered to be a late mainfeastation of nutritional deficiencies, and even mild anemia is not the earilest sign of such a deficiency. Therefore, the object of therapy is to correct underlying deficiency rather than merely its manifestation. Iron deficiency anemia is generally much the most common form of anemia. And it is very prevalent particularly in pregnant women and young children, especially under five year of life. According to the rapid growth rate of infants, dietary iron should he provided for infants over three months of age in adequate amounts for the synthesis of hemoglobin required by the increasing blood volume and for the demands of newly formed cells. The principal causes of iron deficiency anemia are an inadequate dietary iron content, interference with absorption of iron from the intestine, excessive losses of iron from the body, disturbance of iron metabolism by infection, and social and cultural environments. The present study is planned to obtain informations concerning nutritional anemia through anthropometric and biochemical determinations for the assessment of nutriture in pre-school children. Determination was taken in 226 pre-school children in ruraI arae in 1968, 122 pre-school children in 1970, and 1526 hospitalized pre-school children in 1970. The results of this study are as follows; (1) According to Iowa Malnutrition Borderline (85 percentile) for weight, the proportions of underweighed pre-school boys and girls in rural area were 47.2% and 46.2% in1968, and were 36.1% and 51.8% in 1970. According to Iowa Malnutrition Borderline for height, the proportions of underheight boys and girls in rural area were 30.5% and 33.7%, and were 26.2% and 21.8% in 1970. Malnutrition scores of underweight for height values of boys and girls in rural area were 19.3 and 17.3 in 1968, and the scores of boys and girls were 15.6 and 15.5 in 1970. (2) The mean hemoglobin values of boys and girls in rural area were $11.2{\pm}1.8g/100ml\;and\;11.4{\pm}1.6g/100ml$ in 1968. In 1970, the mean values of boys and girls in rural area were $11.3{\pm}1.3g/100ml\;and\;11.7{\pm}2.4g/100ml$. The mean hemoglobin values of hospitalized boys and girls were $11.9{\pm}2.2g/100ml\;and\;11.7{\pm}2.4g/100ml$ in 1970. It is found that 92 of 215 children (42.7%) in rural area had concentrations of hemoglobin less than 11.0g/100ml in 1968. In 1970, 55 of 121 children (45.4%) in rural area and 559 of 1526 hospitalized children (36.6%) had concentrations of hemoglobin less than 11.0g/100ml. (3) The mean hematocrit levels of hospitalized boys and girls were $35{\pm}26.8%\;and\;35.4{\pm}6.4%$ in 1970. And 443 of 1334 hospitalized children (33.2%) had hematocrit values below 33%. (4) The average mean corpuscular hemoglobin concentration levels of hospitalized boys and girls were $32.4{\pm}2.2\;and\;32.3{\pm}2.2$ in 1970. And 1016 of 1352 hospitalized children (75.1%) had the mean corpuscular hemoglobin values below 34. (5) The mean iron values of young children in rural area and hospitalized children were $62.0{\pm}6.3{\mu}g/100ml\;and\;60.7{\pm}22.8{\mu}g/100ml$. The proportions of anemia cases below $50{\mu}g/100ml$ in rural area was 37.9%, and 34.3% in hospitalized children. (6) The mean total iron binding capacity of young children in rural area was $376{\pm}57.88{\mu}g/100ml,\;and\;342.2{\pm}6.15{\mu}g/100ml$ in hospitalized children. (7) The average transferrin saturation percentage of young children in rural area was $16.9{\pm}4.7%,\;and\;18.0{\pm}8.4%$ in hospitalized children. The proportions of anemia cases below 15% of young chi1dren in rural area and hospitalized children were 48.3% and 41.2%. Therefore, authors wish to recommend that the following further studies should be undertaken: (1) Standardization of simplied laboratory examination of nutritional anemia. (2) The prevalence of nutritional anemia and the requirements of iron, folate, and vitamin $B_{12}$ of pre-school children. (3) The content and absorption of iron in Korean food. (4) The pathogenesis of nutritional anemia and prevention of parasitic disease. (5) Maternal health and nutrition education.

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Co-Ni 합금위에서 수직방향으로 정렬된 탄소나노튜브의 성장 (Growth of vertically aligned carbon nanotubes on Co-Ni alloy metal)

  • 이철진;김대운;이태재;박정훈;손권희;류승철;송홍기;최영철;이영희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 D
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    • pp.1504-1507
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    • 1999
  • We have grown vertically aligned carbon nanotubes in a large area of Co-Ni codeposited Si substrates by the thermal CVD using $C_2H_2$ gas. Since the discovery of carbon nanotubes, Synthesis of carbon nanotubes for mass production has been achieved by several methods such as laser vaporization arc discharge, and pyrolysis. In particular, growth of vertically aligned nanotubes is of technological importance for applications to FED. Recently, vertically aligned carbon nanotubes have been grown on glass by PECVD Aligned carbon nanotubes can be also grown on mesoporous silica and Fe patterned porous silicon using CVD. Despite such breakthroughs in the growth, the growth mechanism of the alignment are still far from being clearly understood. Furthermore, FED has not been clearly demonstrated yet at a practical level. Here, we demonstrate that carbon nanotubes can be vertically aligned on catalyzed Si substrate when the domain density reaches a certain value. We suggest that steric hindrance between nanotubes at an initial stage of the growth forces nanotubes to align vertically and then nanotubes are further grown by the cap growth mechanism.

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Intimate Understanding for Growth Mode of Graphene on Copper

  • 송우석;전철호;김수연;김유석;김성환;이수일;정대성;박종윤
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.181-181
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    • 2012
  • Direct synthesis of graphene using a chemical vapor deposition (CVD) has been considered a facile way to produce large-area and uniform graphene film, which is an accessible method from an application standpoint. Hence, their fundamental understanding is highly required. Unfortunately, the CVD growth mechanism of graphene on Cu remains elusive and controversial. Here, we present the evidences for two different growth modes of graphene on Cu investigated by varying carbon feedstock (C2H2 and CH4) and working pressure. The number of uniform graphene layer grown by C2H2 increased with increasing its injection time. A combined secondary ion mass spectrometry (SIMS) and X-ray diffraction (XRD) study revealed a carbon-diffused Cu layer created below surface region of Cu substrate with the expansion of Cu lattice. The graphene on Cu was grown by the diffusion and precipitation mode not by the surface adsorption mode, because similar results were observed in graphene/Ni system. The carbon-diffused Cu layer was also observed after graphene growth under high CH4 pressure. Based on various previous results and ours, we have successfully found that there are two selective growth modes for graphene on Cu substrate, and a desired mode can be chosen by tuning working pressure corresponding to the kind of carbon feedstock. We believe that this finding will shed light on high quality graphene growth and its multifaceted applications.

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다양한 아미노실란을 이용한 이산화탄소 흡착제 합성 및 흡착 특성 (Synthesis of CO2 Adsorbent with Various Aminosilanes and its CO2 Adsorption Behavior)

  • 전재완;고영수
    • 공업화학
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    • 제27권1호
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    • pp.80-85
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    • 2016
  • 넓은 비표면적과 큰 기공 부피를 갖는 실리카에 다양한 아미노실란 화합물을 in-situ 중합법을 통해 기능화 후 이산화탄소 흡착 특성을 확인하였다. 이산화탄소 흡착 기능기로 아민기가 포함된 아미노실란 화합물이 사용되었다. 흡착제의 흡착 특성 분석을 위해 질소 흡 탈착 실험과 원소분석, in situ FT-IR, TGA를 이용하였다. 흡착제 합성 전후를 비교하였을 때 폴리아미노실란이 기능화되면 표면적과 기공부피 및 크기가 감소하였으며 실리카 기공 부피의 70%에 해당하는 폴리아미노실란 화합물을 기능화 시켰을 경우 기공 부피의 100% 기능화 보다 이산화탄소 흡착능이 향상되었다. 흡착 온도를 비교하며 $30^{\circ}C$보다 $75^{\circ}C$에서 폴리아미노실란 화합물의 열팽창과 자유부피 증가로 흡착능이 증가하였고, 2NS/NPS-2의 경우 기공 부피 70% 기능화와 흡착 온도 $75^{\circ}C$에서 9.2 wt%의 높은 $CO_2$ 흡착능을 보였다.

CDMA/TDMA 기반 무선 원격계측 시스템용 모뎀의 VLSI 구조 설계 (A VLSI Architecture Design of CDMA/TDMA Modem Chipsets for Wireless Telemetry Systems)

  • 이원재;이성주;이서구;정석호;김재석
    • 대한전자공학회논문지SD
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    • 제41권5호
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    • pp.107-114
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    • 2004
  • 본 논문에서는 CDMA 및 TDMA 기술을 기반으로 하는 무선 원격계측 시스템용 모뎀에 적합한 최적 하드웨어 구조 및 VLSI 설계에 대해서 제시한다. 무선 원격계측 시스템은 계측이 필요한 다수의 지점에 소형 무선계측기(RT: Remote Terminal)를 설치하고, 설치된 무선계측기로부터 계측데이터를 무선으로 수집하기 위해 제안된 시스템이다. 무선 원격계측 시스템은 계측데이터를 전송하기 위한 다수의 RT와 RT로부터 데이터를 수집하는 1개의 CU(Central Unit)로 구성된다. 본 논문에서는 이러한 RT와 CU용 모뎀에 적합한 최적 하드웨어 구조를 제안하였고, 제안된 구조를 Verilog HDL로 설계 및 검증하였다. Verilog HDL로 설계된 모뎀은 Synopsys/sup TM/툴을 이용하여 게이트 수준으로 합성되었고, 합성결과 RT 및 CU용 모뎀은 0.6㎛ 공정에서 각각 약 27K 게이트와 222K 게이트의 하드웨어 복잡도를 가졌다. 제안된 모뎀은 Altera/sup TM/ FPGA로 구현 및 검증되었다.

DMB 휴대용 단말기를 위한 Reed-Solomon 복호기의 설계 (Hardware design of Reed-solomon decoder for DMB mobile terminals)

  • 류태규;정용진
    • 대한전자공학회논문지SD
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    • 제43권4호
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    • pp.38-48
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    • 2006
  • 본 논문에서는 DMB(Digital Multimedia Broadcasting) 단말기에서 사용하기 위하여 유클리드(Euclid) 알고리즘 기반의 RS(255,239,t=8) 복호기를 설계하였다 DMB는 휴대 단말기 상에 방송서비스 제공이 목적이므로 사용된 RS 복호기는 면적이 작아야 하며 실시간처리를 위해 복호 지연시간이 짧아야 한다. 두 조건을 만족시키기 위해 에러의 위치 및 크기를 찾는 방법으로 유클리드 알고리즘을 수정하여 사용하였다. 유클리드 알고리즘 상에서 유한체 나눗셈 연산을 위해 사용하는 Inverse ROM을 17 클럭을 소모하는 나눗셈기로 대체하여 면적을 줄였으며, 유한체 나눗셈기로 인한 지연 시간을 줄이기 위해 차수 연산 없이 유클리드 알고리즘의 동작 제어가 가능한 수정된 유클리드 알고리즘을 제안하였다. 제안한 유클리드 알고리즘은 기본 유클리드 알고리즘에 비해 비슷한 지연시간 조건 하에서 면적을 25% 정도 줄일 수 있었다. 삼성 STD130 $0.18{\mu}m$ 표준 셀 라이브러리를 이용하여 Synopsys 상에서 합성한 결과 유클리드 블록은 30,228개의 게이트수를 가지며 288 클럭을 소모하였으며, 전체 RS 복호기의 크기는 약 45,000 게이트였다.

Effect of Lubricant with Nanodiamond Particles in Sliding Friction

  • Adzaman, M.H.;Rahman, A.;Lee, Y.Z.;Kim, S.S.
    • Tribology and Lubricants
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    • 제31권4호
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    • pp.183-188
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    • 2015
  • This paper presents the experimental effects of lubricant with nanodiamond particles in sliding friction. In order to improve the performance of lubricants many additives are used, such as MoS2, cadmium chloride, indium, sulfides, and phosphides. These additives are harmful to human health and to the environment, so alternatives are necessary. One such alternative is nanodiamond powder, which has a large surface area. In order to investigate the effect of nanodiamonds in lubricants under sliding friction, they are dispersed in the lubricant at a variety of concentrations (0 wt%, 0.1 wt%, 0.3 wt%, 0.5 wt%, and 1 wt%) using the matrix synthesis method. Friction and wear tests are performed according to the ASTM G99 method using a pin-on-disc tester at room temperature. The specimens used in this experiment are AISI 52100 ball bearings and AISI 1020 steel discs. During the test, lubricant mixed with nanodiamond is supplied constantly to keep the two bodies separated by a lubricant film. To maintain boundary lubrication, the speed is set to 0.18 m/s and a load of 294 N is applied to the disc through the pin. Results are recorded by using workbench software over the test duration of 10 minutes. Experimental results show that when the concentration of nanodiamond increases, the coefficient of friction decreases. However, above a nanodiamond concentration of 0.5 wt%, both the coefficient of friction and wear volume increase. From this experiment, the optimum concentration of nanodiamond showing a minimum coefficient of friction of 0.09 and minimum wear volume of 0.82 nm2 was 0.5 wt%.

Electrical and Optical Properties of P-type Amorphous Oxide Semiconductor Mg:$ZnCo_2O_4$ Thin-Film

  • Lee, Chil-Hyoung;Choi, Won-Kook;Lee, Jeon-Kook;Choi, Doo-Jin;Oh, Young-Jei
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.87-87
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    • 2011
  • Oxide semiconductors are attractive materials for thin-film electronics and optoelectronics due to compatibility with synthesis on large-area, glass and flexible substrate. However, development of thin-film electronics has been hampered by the limited number of semiconducting oxides that are p-type. We report on the effect of the oxygen partial pressure ratio in the gas mixture on the electrical and optical properties of spinel Mg:$ZnCo_2O_4$ thin films deposited at room temperature using RF sputtering, that exhibit p-type conduction. The thin-films are deposited at room temperature in a background of oxygen using a polycrystalline Mg:$ZnCo_2O_4$ ablation target. The p-type conduction is confirmed by positive Seebeck coefficient and positive Hall coefficient. The electrical resistivity and carrier concentration in on dependent Mg:$ZnCo_2O_4$ thin films were found to be dependent on the oxygen partial pressure ratio. As a result, it is revealed that the Mg:$ZnCo_2O_4$ thin-films were greatly influenced on the electrical and optical properties by the oxygen partial pressure condition. The visible region of the spectrum of 36~85%, and hole mobility of 1.1~3.7 $cm^2$/Vs, were obtained.

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