Solar cells exhibit different power outputs in different climates. In this study, the temperature dependence of open-circuit voltage(V-oc), short-circuit current(I-sc), fill factor(FF) and the efficiency of screen-printed single-crystal silicon solar cells were studied. One group was fabricated with homogeneously-doped emitters and another group was fabricated with selectively-doped emitters. While varying the temperature (25, 40, 60 and 80˚C), the current-voltage characteristics of the cells were measured and the leakage currents extracted from the current-voltage curve. As the temperature increased, both the homogeneously-doped and selectively-doped emitters showed a slight increase in I-sc and a rapid degradation of V-oc. The FF and efficiency also decreased as temperature increased in both groups. The temperature coefficient for each factor was calculated. From the current-voltage curve, we found that the main cause of V-oc degradation was an increase in the intrinsic carrier concentration. The temperature coefficients of the two groups were compared, leading to the idea that structural effects could also affect the temperature dependence of current-voltage characteristics.

Inorganic pigments have high thermal stability and chemical resistance at high temperature. For these reasons, they are used in clay, paints, plastic, polymers, colored glass and ceramics. CoAl2O4 nano-powder was synthesized by reverse-micelle processing the mixed precursor(consisting of Co(NO3)2 and Al(NO3)3). The CoAl2O4 was prepared by mixing an aqueous solution at a Co:Al molar ratio of 1:2. The average particle size, and the particle-size distribution, of the powders synthesized by heat treatment (at 900; 1,000; 1,100; and 1,200˚C for 2h) were in the range of 10-20 nm and narrow, respectively. The average size of the synthesized nano-particles increased with increasing water-to-surfactant molar ratio. The synthesized CoAl2O4 powders were characterized by X-ray diffraction analysis(XRD), field-emission scanning electron microscopy(FE-SEM) and color spectrophotometry. The intensity of X-ray diffraction of the synthesized CoAl2O4 powder, increased with increasing heating temperature. As the heating temperature increased, crystal-size of the synthesized powder particles increased. As the R-value(water/surfactant) and heating temperature increased, the color of the inorganic pigments changed from dark blue-green to cerulean blue.

This is the study on diffusion of ceramic body oxide compounds to glaze. For ceramic bodies, no ferrous oxides contain white ware, celadon, and 3 wt% iron oxides contained white ware was used in this experiment. These ceramic bodies were glazed by transparency glaze, iron oxides contained glaze, and glaze made by pine tree ash that treated in 1240 degree, under reduction condition for an hour. An electron probe microanalyzer(EPMA) was used to study diffusion of oxides and to calculate distance of ceramics bodies. As a result, only iron oxide and magnesium oxide from the body diffused to glaze, and also made a band which shown very thin layer of iron oxide and magnesium oxide between the body and glaze. The densest band of iron oxide formed 100 to 150μm in the glaze, and the densest band of magnesium oxide was found 50 to 100μm in the glaze. Therefore, it could be concluded that iron oxide in the body is diffused to the glaze and it affects the color of glaze, even though iron oxide exists in the glaze. Furthermore, the thickness of the glaze has an effect on the color of celadon.

Thermal barrier coatings(TBCs) are being applied in many industrial fields such as thermal power generation, aviation and seasonal fields. ZrO2-Y2O3(8%) thermal spray coating powders are commercially used as thermal-barrier coating materials to protect against oxidation and corrosion of heat-resistant alloys at elevated temperatures. Currently, ZrO2-Y2O3(8%) thermal-spray powder is made using the industrial co-precipitation process, which is very complex and requires a lot of time. In this study, orthorhombic ZrO2 and Y2O3 powders were fabricated by mechanical mixing, which is more economical than the co-precipitation process. A tetragonal, yttria-stabilized zirconia(YSZ) coating-layer was produced by plasma spraying, using orthorhombic ZrO2-Y2O3(8%) powder. Our experimental results indicate that ZrO2-Y2O3(8%) mixed powder can be used economically in industry because it is no longer necessary to make this powder by liquid and gas-phase methods.

A spherical Sr4Al14O25:Eu2+ phosphor for use in white-light-emitting diodes was synthesized using a liquid-state reaction with two precipitation stages. For the formation of phosphor from a precursor, the calcination temperature was 1,100˚C. The particle morphology of the phosphor was changed by controlling the processing conditions. The synthesized phosphor particles were spherical with a narrow size-distribution and had mono-dispersity. Upon excitation at 395 nm, the phosphor exhibited an emission band centered at 497 nm, corresponding to the 4f65d→4f7 electronic transitions of Eu2+. The critical quenching-concentration of Eu2+ in the synthesized Sr4Al14O25:Eu2+ phosphor was 5 mol%. A phosphor-converted LED was fabricated by the combination of the optimized spherical phosphor and a near-UV 390 nm LED chip. When this pc-LED was operated under various forward-bias currents at room temperature, the pc-LED exhibited a bright blue-green emission band, and high color-stability against changes in input power. Accordingly, the prepared spherical phosphor appears to be an excellent candidate for white LED applications.

Metal films (i.e., Ti, Al and SUH310S) were prepared in a magnetron sputtering apparatus, and their cross-sectional structures were investigated using scanning electron microscopy. The apparatus used consisted of a cylindrical metal target which was electrically grounded, and two anode rings attached to the top and to the bottom of the target. A wire was placed along the center-line of the cylindrical target to provide a substrate. When the electrical potential of the substrate was varied, the metal-film formation rate depended on both the discharge voltage and the electrical potential of the substrate. As we made the magnetic field stronger, the plasma which appeared near the target collected on the plasma wall surface and thereby decreased the bias current. The bias current on the conducting wire was different from that for cation collection. The bias current decreased because the collection of cations decreased when we increased the magnetic-coil current. When the substrate was electrically isolated, the films deposited showed a slightly coarse columnar structure with thin voids between adjacent columns. In contrast, in the case of the grounded substrate, the deposited film did not show any clear columns but instead, showed a densely-packed granular structure. No peeling region was observed between the film and substrate, indicating good adhesion.

CaWO4:Smx(x=0, 0.5, 1.0, 1.5, 2.0mol%) white phosphors with different concentrations of Sm3+ ions weresynthesized using the hydrothermal method. The crystal structure, surface, and optical properties of the CaWO4:Smphosphors were investigated using X-ray diffraction(XRD), field-emission scanning electron microscopy(FE-SEM),photoluminescence(PL) and photoluminescence excitation(PLE). From the XRD results, the crystal structure of theCaWO4:Sm phosphors was found to be tetragonal. The CaWO4:Sm phosphors became more cohesive with increasing Sm3+-ion concentration. The photoluminescence excitation(PLE) peak of the phosphors, at around 250nm, was ascribed to thetransition from the 1A1 ground-state to the high-vibration level of 1T2 in the WO42− complex. The maximum emissionspectra of the phosphors were observed when the Sm3+ concentration was 0.5mol%. The luminescence intensity of theCaWO4 phosphors was decreased for Sm3+ concentrations greater than 0.5mol%.

The use of solar energy generation is steadily increasing, and photovoltaic modules are connected in series to generate higher voltage and power. However, solar panels are exposed to high-voltage stress (up to several hundreds of volts) between grounded module frames and the solar cells. Frequent high-voltage stress causes a power-drop in the modules, and this kind of degradation is called potential induced degradation (PID). Due to PID, a significant loss of power and performance has been reported in recent years. Many groups have suggested how to prevent or reduce PID, and have tried to determine the origin and mechanism of PID. Even so, the mechanism of PID is still unclear. This paper is focused on understanding the PID of crystalline-silicon solar cells and modules. A background for PID, as well as overviews of research on factors accelerating PID, mechanisms involving sodium ions, PID test methods, and possible solutions to the problem of PID, are covered in this paper.

Cobalt nano-rods were fabricated using a template-free electrochemical-deposition process. The structure of cobalt electro-deposits strongly depends on the electrolyte composition and on the density of the applied current. In particular, as the content of boric acid increased in the electrolyte, deposits of semi-spherical nuclei formed, and then grew into one-dimensional nano-rods. From analysis of the electro-deposits created under the conditions of continuous and pulsed current, it is suggested that the distribution of the active species around the electrode/electrolyte interface, and their transport, might be an important factor affecting the shape of the deposits. When transport of the active species was suppressed by lowering the deposition temperature, more of the well-defined nano-rod structures were obtained. The optimal conditions for the preparation of well-defined nano-rods were determined by observing the morphologies resulting from different deposition conditions. The maximum height of the cobalt nano-rods created in this work was 1μm and it had a diameter of 200 nm. Structural analysis proved that the nano-rods have preferred orientations of (111).

In this experiment, a highly porous scaffold of biphasic calcium phosphate (BCP) was prepared using the spongereplica method. The BCP scaffold was coated with 58S bioactive glass (BG) and sintered for a second time. The resulting scaffold was coated with gelatin (Gel) and cross-linked with [3-(3-dimethyl aminopropyl) carbodiimide] and N-Hydroxysuccinamide (EDC-NHS). The initial average pore size of the scaffold ranged from 300 to 700μm, with more than 85 % porosity. The coating of BG and Gel had a significant effect on the scaffold-pore size, decreasing scaffold porosity while increasing mechanical strength. The material and surface properties were evaluated by means of several experiments involving scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). Cytotoxicity was evaluated using MTT assay and confocal imaging of MC3T3-E1 pre-osteoblast cells cultured in vitro. Three types of scaffold (BCP, BCP-BG and BCP-BG-Gel) were implanted in a rat skull for in vivo evaluation. After 8 weeks of implantation, bone regeneration occurred in all three types of sample. Interestingly, regeneration was found to be greater (geometrically and physiologically) for neat BCP scaffolds than for two other kinds of composite scaffolds. However, the other two types of scaffolds were still better than the control (i.e., defect without treatment).

When sunlight irradiates a boron-doped p-type solar cell, the formation of BsO2i decreases the power-conversion efficiency in a phenomenon named light-induced degradation (LID). In this study, we used boron-doped p-type Cz-Si solar cells to monitor this degradation process in relation to irradiation wavelength, intensity and duration of the light source, and investigated the reliability of the LID effects, as well. When halogen light irradiated a substrate, the LID rate increased more rapidly than for irradiation with xenon light. For different intensities of halogen light (e.g., 1 SUN and 0.1 SUN), a lower-limit value of LID showed a similar trend in each case; however, the rate reached at the intensity of 0.1 SUN was three times slower than that at 1 SUN. Open-circuit voltage increased with increasing duration of irradiation because the defect-formation rate of LID was slow. Therefore, we suppose that sufficient time is needed to increase LID defects. After a recovery process to restore the initial value, the lower-limit open-circuit voltage exhibited during the re-degradation process showed a trend similar to that in the first degradation process. We suggest that the proportion of the LID in boron-doped p-type Cz-Si solar cells has high correlation with the normalized defect concentrations (NDC) of BsO2i. This can be calculated using the extracted minority-carrier diffusion-length with internal quantum efficiency (IQE) analysis.

The effect of oxygen pressure on the synthesis of ZnO nanowires by means of melt-oxidation of an Al-Zn mixture was investigated. The samples were prepared in oxygen ambient for 1 h at 1,000˚C under oxygen pressure ranging from 0.5 to 100 Torr. ZnO nanowires were formed at oxygen pressures lower than 10 Torr. As the oxygen pressure increased from 0.5 to 10 Torr, the width of the nanowires increased, but their length decreased. The ZnO nanowires had a needle shape, which became gradually thinner toward the tip. X-ray diffraction patterns showed that the nanowires had a hexagonal wurtzite structure. However, ZnO nanowires were not observed when the oxygen pressure increased from 10 Torr to 100 Torr. In roomtemperature cathodeluminescence spectra of the ZnO nanowires, the intensity of ultra-violet emission at 380 nm increased with decreasing oxygen pressure, which indicated that the lower the oxygen pressure, the better the crystallinity of the ZnO nanowires.

Coal-tar pitch, a feedstock which can be heat-treated to create graphite, is composed of very complex molecules. Coal-tar pitch is a precursor of many useful carbon materials (e.g., graphite, carbon fibers, electrodes and matrices of carbon/carbon composites). Modified coal-tar pitch (MCTP) was prepared using two different heat-treatment methods and their properties were characterized and compared. One was prepared using heat treatment in nitrogen gas; the other was prepared under a pressure of 350 mmHg in air. The MCTPs were investigated to determine several properties, including softening point, C/H ratio, coke yield, formation of anisotropic mesophase and viscosity. The MCTPs were subject to considerable changes in chemical composition due to condensation and polymerization in the used-as-received coal-tar pitch after heat-treatment under different conditions. The MCTPs showed considerable increases in softening point, C/H ratio, and coke yield, compared to those of as-received coal-tar pitch. The MCTP formed by heat-treatment in nitrogen showed isotropic phases below 350˚C for 1 h of soaking time. However, MCTP heat-treated under high pressure (350 mmHg) showed isotropic phases below 300˚C, and showed anisotropic phases above 350˚C, for 1 h of soaking time. The viscosity of the MCTPs increased with increase in their softening points.

Commercial activated-carbon used as the electrode material of an electric double-layer capacitor (EDLC) was posttreated with various acids and alkalis to increase its capacitance. The carbon samples prepared were then heat-treated in order to control the amount of acidic functional groups formed by the acid treatments. Coin-type EDLC cells with two symmetric carbon electrodes were assembled using the prepared carbon materials and an organic electrolyte. The electrochemical performance of the EDLC was measured by galvanostatic charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. Among the various activated carbons, the carbon electrodes (CSsb800) prepared by the treatments of coconutshell-based carbon activated with NaOH and H3BO5, and then heat treated at 800˚C under a flow of nitrogen gas, showed relatively good electrochemical performance. Although the specific-surface-area of the carbon-electrode material (1,096m2/g) was less than that of pristine activated-carbon (1,122m2/g), the meso-pore volume increased after the combined chemical and heat treatments. The specific capacitance of the EDLC increased from 59.6 to 74.8 F/g (26%) after those post treatments. The equivalent series resistance of EDLC using CSsb800 as electrode was much lower than that of EDLC using pristine activated carbon. Therefore, CSsb800 exhibited superior electrochemical performance at high scan rates due to its low internal resistance.

Using the spray pyrolysis process, nano-sized cobalt oxide powder with average particle size below 50 nm was prepared from cobalt chloride solution. The influences of the raw material solution on the properties of the powder formed examined. When the concentration of Co was low(20 g/L), the average particle size of the powder formed was roughly 20 nm, and the cohesion between these particles was significantly strong. When the concentration of Co increased to 100 g/L, the droplets nearly failed to exist in circular form and reflected a severely divided form. Furthermore, the average size of the particles formed was roughly 40 nm, and the particles reflected a polygonal form. When the solution was increased to nearly saturation level (Co at 200 g/L), the particle size distribution reflected significant unevenness due to severe droplet division while the surface also reflected significant unevenness. Furthermore, the average size of the particles formed increased significantly to 70 nm. The results of XRD analysis showed that the strength of the peaks reflected very little change when the concentration of Co was increased from 20 g/L to 50 g/L. Alternatively, when the concentration was increased to 100 g/L, the strength of the peaks increased compared to when the concentration was 50 g/L. However, when the concentration was increased to 200 g/L, the strength of the peaks failed to reflect significant change compared to when the concentration was 100 g/L. The specific surface area dramatically decreased by 30 % when the concentration of Co was increased from 20 g/L to 50 g/L. Alternatively, when the concentration of Co the solution increased to 100 g/L, the specific surface area decreased by roughly 15 %. Furthermore, when the concentration of Co was increased to nearly saturation level(200 g/L), the specific surface area decreased by roughly 35%.

오늘날 유전자 조작 기술이 과거 사회부적격자 제거와 유대인의 대학살 이라는 나쁜 함의를 갖고 있는 독일 나치 우생학을 새롭게 불러낼 것이라 는 우려가 크다. 유전학과 우생학 사이에 밀접한 관련이 있는 것은 사실이 다. 하지만 과거의 우생학과 새로운 우생학 사이에 현격한 차이가 있음을 간과해서는 안 된다. 이른바 ‘인간 유전체 계획’을 기점으로 신/구유전학 이 나뉘고, 이에 따라 우생학적 함의에는 현격한 차이가 있다. 즉 과거의 우생학이 국가권력에 의한 인간의 ‘종적’ 개선과 사회부적격자의 제거를 목표로 했다면, 새로운 우생학은 새로운 유전학이 개인의 유전형질을 변 경시켜 인간의 자질과 능력이 향상된 우생 인간의 탄생을 목표로 한다. 이 점에서 과거의 우생학과 오늘날 우생학은 분명히 다르다. 그렇다 하더라 도 새로운 유전학의 우생정치 이념이 정당화되는 것은 아니다. 이에 우리는 새로운 유전학의 우생학적 성격을 ‘자유주의적’인 것으로 규정하고(2장), 이러한 자유주의 우생학을 철학적으로 정당화시켜 주는 근거가 ‘자율’과 ‘추정동의’에 있음을 논증했다(3장). 특히 자율은 자유주 의자에게 도덕적 ‘선’을 구성하는 근본 원리이다. 하지만 우생학적 선택이 자율의 가치를 지니기 위해서는 ‘유의미한 인생설계’의 개념 해명이 선행 되어야 하지만, 자녀의 인생설계에 대한 부모의 선택이 자녀들에게는 오 히려 ‘강제’이다. 여기서 자녀교육론이 부모의 (우생학적) 재량권을 허용 하는 논거일 수 없다(4장). 이에 이 글은 임상유전학의 우생정치 이념의 허구성을 비판하고, 이에 대한 법적 ‧ 정치적 대응을 촉구한다(5장).

루만에 의하면 현대사회에서 (의사)소통의 중요한 매체는 두 가지이다. 정보를 유포하는 매체와 일반화된 상징적 소통매체(또는 성공매체)가 그 것들이다. 이 논문에서는 정보유포 매체를 중심으로 재난의 위험과 세계 시민사회의 관계에 대해 살펴본다. 근대 시민사회의 발현을 가능하게 했 던 정보유포 매체는 활자매체라는 것이 일반적인 인식이다. 그러나 현대 사회에서 전자매체 특히 디지털매체의 사회구성적 효과에 대해서는 의견이 분분하다. 이 논문에서는 벡, 루만, 하이어의 관점을 비교하면서, 현대 사회에서 시민 주체의 형성과 관련하여 디지털매체의 중요성이 일방적으 로 강조되는 경향을 비판하고자 한다. 특히 세월호 참사와 관련하여 한국 사회에서 디지털매체뿐만 아니라 전자 대중매체의 역할이 새롭게 확인될 수 있음을 강조한다. 즉 언론통제 상황에서도 TV 전자매체가 전혀 의도하 지 못한 상태에서 불러일으키는 사회적 감정의 효과를 강조하고자 한다.

약관규제법을 갖고 있는 우리나라로서는 ‘약관규제’ 외에 ‘계약조항규제’가 필요한지에 대한 논의는 거의 없는 상황이다. 그런데 국제적인 계약규범이나 원칙(이하 단순히 ‘국제적인 계약규범’이라고 한다)에서는 오히려 약관규제보다는 약관을 포함한 계약조항의 규제가 일반화되고 있는 듯한 인상을 받는다. 1993년 EC불공정조항지침에 의해 처음으로 국제적으로 주목받기 시작한 계약조항규제는 그 후에 등장한 국제적인 계약규범에도 영향을 미쳐 PECL(유럽계약법원칙, 2000), DCFR(공통참조기준초안, 2009)을 거쳐 최근에는 CESL(유럽공통매매법, 2011)에서도 계약조항규제가 계약규범의 일부로 편입되었다. 더욱이 독일의 경우 약관규제법의 모법국가이기 때문에 약관규제의 국가로 생각하기 쉬우나, 사실은 1993년의 EC불공정조항지침의 국내법화를 위해 소비자계약조항규제가 약관규제법의 일부로 신설되었고(1996), 따라서 이미 소비자계약에서 계약조항규제가 이루어지고 있는 국가라는 점에 주의하여야 한다. 한편 일본에서도 주지하는 바와 같이 소비자계약법을 제정할 때(2000) 약관규제에 한정하지 않고 널리 계약조항규제를 위한 조문을 신설하였다. 우리법상 약관은 ‘일방성’, ‘정형성’, ‘사전성’을 개념표지로 하여 정의 된다. 즉 계약의 일방 당사자인 사업자가(일방성), 여러 명의 상대방과 계약을 체결하기 위해 일정한 형식으로(정형성), 사전에 미리 작성해 놓은(사전성), 계약의 내용이 되는 것이 약관인 것이다(약관규제법 제2조 제1호). 이에 반해 전술한 국제적인 계약규범에서 규제의 대상이 되는‘계약조항’은 계약내용이 되는 모든 계약조항을 의미하는 것이 아니라, 일방 당사자가 상대방과 협의나 교섭없이 미리 작성해 놓은(개별교섭을 거치지 않은) 계약내용을 말하는 것이다. 상대방과의 협의나 교섭에 의해 작성된 것이라면 사적자치의 원칙상 애초에 계약조항규제를 논할 실익이 없기 때문이다. 이와 같이 본다면 계약조항규제의 대상이 되는 계약조항은 약관의 개념표지 중에서 ‘정형성’만을 제외한 개념이라고 볼 것이다. 계약조항은 다수의 상대방과의 계약체결을 위해 작성된 것은 아니지만, 일방 당사자가 사전에 작성한 계약내용이라는 점에서는 약관과 다를 바가 없기 때문이다. 이와 같이 이해하는 한 이제는 약관규제 외에 우리법상으로도 계약조항규제가 별도로 필요한지, 또 그 경우 그 방법은 어떠해야 하는지 등에 대해 진지하게 검토할 시점이 되었다고 생각한다. 본고는 이와 같은 점을 배경으로 하여 향후 논의를 위한 단초를 제공한다는 입장에서 약관규제 외에 계약조항규제가 필요하다는 점에 대해 문제를 제기하고자 한 것이다.

In order to evaluate the quality of indoor air due to the remodeling and newly-built in S City, 60 schools wereinvestigated in formaldehyde (HCHO) and total volatile organic compounds (TVOCs). One school exceeded thenational standard of formaldehyde 100µg/m³ at 1st measurement. Thirty-eight schools showed higher level ofTVOCs over 400µg/m³ at 1st measurement. Twelve schools showed higher level of TVOCs over 400µg/m³ at2nd measurement. This result derived from TVOCs which originated from the building materials and finishingmaterials. To prevent the pollution of indoor air quality at schools caused by formaldehyde and TVOCs, therecommendation of environmentally-friendly building materials, the diminishment of emission by bakeout process,the efficient combination of natural ventilation and mechanical ventilation, and antibacterial effect of chemicalcontrol measures as photo-catalysts should be given positive investigation.

Atmospheric stability is an important parameter which effects pollutant dispersion in the atmospheric boundary layer.The objective of this paper was to verify the effect of stability conditions on odor dispersion downwind from anarea source using computational fluid dynamic (CFD) modeling. The FLUENT Realizable k-ε model was used tosimulate odor dispersion as released by an odor source. A total of 3 simulations demonstrated the effects of unstable,neutral, and stable atmospheric conditions. Unstable atmospheric stability conditions produced a shorter odor plumelength compared with neutral and stable conditions because of stronger convective effects. Like other studies,unstable atmospheric condition produced higher plume height compared with neutral and stable conditions.