In this study, we inserted a Zn buffer layer into a AZO/p-type a-si:H layer interface in order to lower the contact resistance of the interface. For the Zn layer, the deposition was conducted at 5 nm, 7 nm and 10 nm using the rf-magnetron sputtering method. The results were compared to that of the AZO film to discuss the possibility of the Zn layer being used as a transparent conductive oxide thin film for application in the silicon heterojunction solar cell. We used the rf-magnetron sputtering method to fabricate Al 2 wt.% of Al-doped ZnO (AZO) film as a transparent conductive oxide (TCO). We analyzed the electro-optical properties of the ZnO as well as the interface properties of the AZO/p-type a-Si:H layer. After inserting a buffer layer into the AZO/p-type a-Si:H layers to enhance the interface properties, we measured the contact resistance of the layers using a CTLM (circular transmission line model) pattern, the depth profile of the layers using AES (auger electron spectroscopy), and the changes in the properties of the AZO thin film through heat treatment. We investigated the effects of the interface properties of the AZO/p-type a-Si:H layer on the characteristics of silicon heterojunction solar cells and the way to improve the interface properties. When depositing AZO thin film on a-Si layer, oxygen atoms are diffused from the AZO thin film towards the a-Si layer. Thus, the characteristics of the solar cells deteriorate due to the created oxide film. While a diffusion of Zn occurs toward the a-Si in the case of AZO used as TCO, the diffusion of In occurs toward a-Si in the case of ITO used as TCO.

Saw wires have been widely used in industries to slice silicon (Si) ingots into thin wafers for semiconductor fabrication. This study investigated the microstructural and mechanical properties, such as abrasive wear and tensile properties, of a saw wire sample of 0.84 wt.% carbon steel with a 120 μM diameter. The samples were subjected to heat treatment at different linear velocities of the wire during the patenting process and two different wear tests were performed, 2-body abrasive wear (grinding) and 3-body abrasive wear (rolling wear) tests. With an increasing linear velocity of the wire, the tensile strength and microhardness of the samples increased, whereas the interlamellar spacing in a pearlite structure decreased. The wear properties from the grinding and rolling wear tests exhibited an opposite tendency. The weight loss resulting from grinding was mainly affected by the tensile strength and microhardness, while the diameter loss obtained from rolling wear was affected by elongation or ductility of the samples. This result demonstrates that the wear mechanism in the 3-body wear test is much different from that for the 2-body abrasive wear test. The ultra-high tensile strength of the saw wire produced by the drawing process was attributed to the pearlite microstructure with very small interlamellar spacing as well as the high density of dislocation.

Nanostructured cobalt materials have recently attracted considerable attention due to their potential applications in high-density data storage, magnetic separation and heterogeneous catalysts. The size as well as the morphology at the nano scale strongly influences the physical and chemical properties of cobalt nano materials. In this study, cobalt nano particles synthesized by a a polyol process, which is a liquid-phase reduction method, were investigated. Cobalt hydroxide (Co(OH)2), as an intermediate reaction product, was synthesized by the reaction between cobalt sulphate heptahydrate (CoSO4·7H2O) used as a precursor and sodium hydroxide (NaOH) dissolved in DI water. As-synthesized Co(OH)2 was washed and filtered several times with DI water, because intermediate reaction products had not only Co(OH)2 but also sodium sulphate (Na2SO4), as an impurity. Then the cobalt powder was synthesized by diethylene glycol (DEG), as a reduction agent, with various temperatures and times. Polyvinylpyrrolidone (PVP), as a capping agent, was also added to control agglomeration and dispersion of the cobalt nano particles. The optimized synthesis condition was achieved at 220˚C for 4 hours with 0.6 of the PVP/Co(OH)2 molar ratio. Consequently, it was confirmed that the synthesized nano sized cobalt particles had a face centered cubic (fcc) structure and with a size range of 100-200 nm.

Flat rolling of wire is an industrial process used to manufacture electrical flat wire, medical catheters, springs, piston segments and automobile parts, among other products. In a multi-step wire flat rolling process, a wire with a circular crosssection is rolled at room temperature between two flat rolls in several passes to achieve the desired thickness to width ratio. To manufacture a flat wire with a homogeneous microstructure, mechanical and metallurgical properties with an appropriate pass schedule, this study investigated the effect of each pass schedule (1stand ~ 4stand) on the microstructures, mechanical properties and widths of cold rolled high carbon steel wires using four-pass flat rolling process. The evolutions of the microstructures and mechanical properties of the widths of cold rolled wires during three different pass schedules of the flat rolling process of high carbon wires were investigated, and the results were compared with those for a conventional eight-pass schedule. In the width of cold rolled wires, three different pass schedules are clearly distinguished and discussed. The experimental conditions were the same rolling speed, rolling force, roll size, tensile strength of the material and friction coefficient. The experimental results showed that the four-pass flat cold rolling process was feasible for production of designed wire without cracks when appropriate pass schedules were applied.

Melt foaming method is one of cost-effective methods to make metal foam and it has been successfully applied to fabricate Mg foams. In this research, AZ31 Mg alloy ingot was used as a metal matrix, using AlCa granular as thickening agent and CaCO3 powder as foaming agent, AZ31 Mg alloy foams were fabricated by melt-foaming method at different foaming temperatures. The porosity was above 41.2%~73.3%, pore size was between 0.38~1.52 mm, and homogenous pore structures were obtained. Microstructure and mechanical properties of the AZ31 Mg alloy foams were investigated by optical microscopy, SEM and UTM. The results showed that pore structure and pore distribution were much better than those fabricated at lower temperatures. The compression behavior of the AZ31 Mg alloy foam behaved as typical porous materials. As the foaming temperature increased from 660˚C to 750˚C, the compressed strength also increased. The AZ31 Mg alloy foam with a foaming temperature of 720˚C had the best energy absorption. The energy absorption value of Mg foam was 15.52 MJ/m3 at a densification strain of 52%. Furthermore, the high energy absorption efficiencies of the AZ31 Mg alloy foam kept at about 0.85 in the plastic plateau region, which indicates that composite foam possess a high energy absorption characteristic, and the Vickers hardness of AZ31 Mg alloy foam decreased as the foaming temperature increased.

The power capacitors used as vehicle inverters must have a small size, high capacitance, high voltage, fast response and wide operating temperature. Our thin film capacitor was fabricated by alumina layers as a dielectric material and a metal electrode instead of a liquid electrolyte in an aluminum electrolytic capacitor. We analyzed the micro structures and the electrical properties of the thin film capacitors fabricated by nano-channel alumina and metal electrodes. The metal electrode was filled into the alumina nano-channel by electroless nickel plating with polyethylene glycol and a palladium catalyst. The spherical metals were formed inside the alumina nano pores. The breakdown voltage and leakage current increased by the chemical reaction of the alumina layer and PdCl2 solution. The thickness of the electroless plated nickel layer was 300 nm. We observed the nano pores in the interface between the alumina layer and the metal electrode. The alumina capacitors with nickel electrodes had a capacitance density of 100 nF/cm2, dielectric loss of 0.01, breakdown voltage of 0.7MV/cm and leakage current of 104μA.

The effect of heat treatment on the micro-structures and the mechanical properties of 0.002% boron added low carbon steel was investigated. The tensile strength reached the peak at about 880-890˚C with the rising quenching temperature and then the hardness decreased sharply, but the tensile strength hardly decreased. The tensile and yield strength decreased and the total elongation increased with a rising tempering temperature, but the tensile and yield strength sharply fell and the total elongation prominently increased from above a 400-450˚C tempering temperature. Tempered martensite embrittlement (TME) was observed at tempering condition of 350-400˚C. In the condition of quenching at 890˚C and tempering at 350˚C, the boron precipitates were observed as Fe-C-B and BN together. The hardness decreased in proportion to the tempering temperature untill 350˚C and dropped sharply above 400˚C regardless of the quenching temperature.

[ WO3 ]powders were ball-milled with an alumina ball for 0-72 hours. In2O3 doped WO3 was prepared by soaking ball-milled WO3 in an InCl3 solution. The mixed powder was annealed at 700˚C for 30 min in an air atmosphere. A paste for screen-printing the thick film was prepared by mixing the WO3:In2O3 powders with α-terpinol and glycerol. In2O3 doped WO3 thick films were fabricated into a gas sensor by a screen-printing method on alumina substrates. The structural properties of the WO3:InO3 thick films were a monoclinic phase with a (002) dominant orientation. The particle size of the WO3:InO3 decreased with the ball-milling time. The sensing characteristics of the In2O3 doped WO3 were investigated by measuring the electrical resistance of each sensor in the test-box. The highest sensitivity to 5 ppm CH4 gas and 5 ppm CH3CH2CH3 gas was observed in the ball-milled WO3:InO3 gas sensors at 48 hours. The response time of WO3:In2O3 gas sensors was 7 seconds and recovery time was 9 seconds for the methane gas.

ZnS:Mn, Dy yellow phosphors for White Light Emitting Diode were synthesized by a solid state reaction methodusing ZnS, MnSO4·5H2O, S and DyCl3·6H2O powders as starting materials. The mixed powder was sintered at 1000oC for 4h in an air atmosphere. The photoluminescence of the ZnS:Mn, Dy phosphors showed spectra extending from 480 to 700nm,peaking at 580nm. The photoluminescence of 580nm in the ZnS:Mn, Dy phosphors was associated with 4T1→6A1 transitionof Mn2+ ions. The highest photoluminescence intensity of the ZnS:Mn, Dy phosphors under 450nm excitation was observedat 4mol% Dy doping. The enhanced photoluminescence intensity of the ZnS:Mn, Dy phosphors was explained by energytransfer from Dy3+ to Mn2+. The CIE coordinate of the 4 mol% Dy doped ZnS:Mn, Dy was X=0.5221, Y=0.4763. Theoptimum mixing conditions for White Light Emitting Diode was obtained at the ratio of epoxy:yellow phosphor=1:2 formCIE coordinate.

The current study was conducted in order to investigate promotional effects of herbal extracts on hair growth in an animal model of mice. There were four experimental groups, including distilled water (DW) as a negative control (NC), 3% minoxidil (MXD) as a positive control (PC), 50% ethanol (EtOH) as a vehicle control (VC), and herbal extract (HE) as the experimental treatment (E). The HE was extracted with ethanol from plants, including Gardenia, Mentha arvensis, Rosemary, and Lavender. Six-week-old C57BL/6 male mice were shaved with an electric clipper and the test materials were topically treated with 0.2 ml per mouse daily for three weeks. Photographic evaluation of hair re-growth was performed weekly during a period of three weeks. The number of mast cells was counted on the dorsal skin section of mice. The enzymes, alkaline phosphatase (ALP) and γ-glutamyl transpeptidase (γ-GT), were determined using a biochemical autoanalyzer. No clinical signs were observed in any of the experimental groups. As a result of photometric analysis, topical application of HE to dorsal skin for two weeks resulted in significantly faster acceleration of hair regrowth, compared with that of the NC or VC group (P<0.05). The PC and E groups showed a significant decrease in mast cell population, compared to the NC group. Activities of ALP and γ-GT were significantly increased in the PC and E groups, compared to the NC or VC group (P<0.05). Taken together, these results suggest that the herbal extract may have hair-growth promoting activity equal to that of MXD.

Zinc oxide nanoparticles (nZnO) are used in a various range, including ceramic manufacture, photocatalysis, UV filters, and the food industry. However, little is known about the effects of micro- and nano-particles during mouse embryo organogenesis. To determine whether ZnO affects size-dependent anomalies during embryonic organogenesis, mouse embryos were cultured for two days with 300 ug/ml micro ZnO (mZnO;80±25 μm) and nZnO (< 100 nm) and the developmental changes were then investigated. Quantity of Zn by inductively coupled plasma mass spectrometry analysis, and expression patterns of various antioxidant enzymes in the embryos were investigated. Embryos exposed to mZnO or nZnO exhibited severe retardation of growth and development. In embryos exposed to mZnO and nZnO, yolk sac diameter, crown-rump length, and head length were significantly diminished. The morphological parameters, including yolk sac circulation, allantois, flexion, heart, hindbrain, midbrain, forebrain, otic system, optic system, branchial bars, maxillary process, mandibular process, olfactory system, caudal neural tube, forelimb, hindlimb, and somites in mZnO and nZnO-treated groups were significantly decreased. Zn absorption of the nZnO-treated group was significantly higher than that of the mZnO-treated group. Significantly decreased levels of CuZn-SOD, Mn-SOD, cGPx, and PHGPx mRNA were observed in the ZnO-treated group. In addition, antioxidant enzyme mRNA expressions of the nZnO group were significantly diminished, less than those of the mZnO treated group. These findings indicate that 300 ug/ml ZnO showed abnormality and nZnO may have a more severe effect than mZnO in developing embryos.

This study was conducted to induce the effective counterplan of odor management in the Sihwa industrial complex(SIC) utilizing to CALPUFF model with sensory odor. The CALPUFF model was applied to simulate a sensory odor, and was evaluated for odor applicability and the distribution status of odor in SIC was predicted. The simulated concentration showed lower than observed concentration but the prediction of odor was so excellent. The simulation result of CALPUFF model for SIC showed that annual mean odor unit was 5∼7 OU/㎥ (min. 3 OU/㎥, max. 25 OU/㎥). The annual mean odor unit in residential area was not high as 1∼3 OU/㎥ but was predicted to be affected by the weather status in the industrial complex. The odor emission sources of high concentration were distributed in the seashore. Therefore the management of the high concentration sources will be further demanded.

This study was conducted in order to evaluate the effect of sericin-calcium (SC) as therapy for ovariectomy-induced osteoporosis in rats. Three weeks after ovariectomy (OVX), Sprague-Dawley rats were divided randomly into three groups: sham-operated group (Sham), ovariectomized group, and SC-treatment group (OVX+SC). Rats in the OVX+SC group were given drinking water containing 0.07% SC for eight weeks. Bone breaking force, mineralization, and blood parameters related to bone metabolism were analyzed. In OVX animals, blood concentration of 17β-estradiol showed a significant decrease, while osteocalcin and type I collagen C-terminal telopeptides (CTx) showed an increase. Breaking force of femurs as well as bone mineral density (BMD), ash, calcium, and phosphorus in femurs showed a significant decrease following OVX. Treatment with SC (0.07% in drinking water) resulted not only in remarkable restoration of the decreased 17β-estradiol and increased osteocalcin and CTx concentrations, but also led to recovery of decreased femoral breaking force, BMD, ash, calcium, and phosphorus. It is suggested that SC effectively improves bone density by preventing bone turnover-mediated osteocalcin, CTx, and minerals, and that it could be a potential candidate for use in therapy or prevention of post-menopausal osteoporosis.

In this study, A method for confirming the putrefaction point of apples by using odor variation as applied in apple storage. The samples were obtained from apple storage at Chuncheon shi Dongnae-myeon using by lung sampler. The complex odor was separated by GC/O and individual odors were then analyzed. In the apple storage, the varieties and number of apples vary based on cultivarsand sales volume of apples. Thus, using an emission chamber in the apple storage is difficult. The odor value of the emission chamber and apple storage is denoted by standardizing the sizes and number of apples. The variations in the ratios of aroma value and off-odor value were investigated. The ratio of the aroma value and off-odor value in the emission chamber increased. However, the apple storage values were applied on the number of apples, thus the values alternately increased and decreased in most cases. If the internal change of apple started, it is ratio of aroma value and off-odor value is cloese to zero. and If the External putrefaction on the apple surface is confirmed, the log value becomes larger than 0.5. Complete putrefaction in the stored apples, the log value close to 1.5. We therefore confirmed that this noninvasive method using odor variation can apply to monitoring the quality of apples in storage.

Liver cancer represents a major health problem with steadily increasing incidence rates. Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third most common cause of cancer-related death. This study was conducted in order to investigate the gross findings following treatment with diethylnitrosamine (DEN) in mice. Sixteen male and female mice (B6C3F₁), initially 20 days of age, received intraparietal injection (20 mg/kg three times for a period of two weeks, IP) or were given drinking water (DW) containing 50 ppm DEN; all mice were sacrificed at the 80^th week of experiments. Hepatocellular adenoma (HCA) and HCC were induced in B6C3F₁), mice by administration of DEN. The numbers of HCA and HCC were 7.4±1.72 (IP) and 7.2±0.86 (DW) in male mice. However, no significant difference was observed between the DW and IP groups. The numbers of HCA and HCC were 0.67±0.33 (IP) and 2.0±0.63 (DW) in female mice. This study showed a tendency for high incidences of liver tumor with long-term exposure of newborn animals by drinking water.

지금까지 우리나라에는 자본주의를 지향하는 자생적인 내부적 動因이 없고, 일본의 강제적 점탈적 역사적 추이에 의해 자본주의로 진입했다고 보는 것은 (미시적 근시안적으로 접근하면) 일본에 의해 강제 개항되기에 이르렀고, 개항에 의해 우리나라가 근대화의 길을 걸었던 것은 현상적으로 나타난 역사적 사실이기 때문이다. 그러나 세계사적인 흐름의 큰 맥락에서 보았을 때, 서양에서 자본주의 체제를 맨 처음 도입한 이래 세계 각국은 先後의 차이는 있을지언정, 전반적인 추세가 점차 자본주의에로 진행해 가고 있었다. 일본은 이러한 시대적 변화에 능동적으로 재빨리 대응하였던 것에 비해, 우리나라는 늦게 대응한 결과일 뿐이라고 보는 것이 본인의 견해이다. 본 논문에서는 자본주의를 지향하는 내생적인 動因으로서, 서양에서의 봉건사회 붕괴과정에 나타난 사회 사상적 변화 과정을 살펴보고, 이러한 사회 사상적 변화가 자본주의 발달과 어떤 관계가 있는지 알아본 뒤에, 이에 관련하여 조선시대의 사회사상은 어떤 것이었는지 구체적으로 살펴보고, 이러한 사회사상이 어떤 경로를 통해 타파되어 가고 있는지 알아보고 자 한다. 다시 말해 조선시대에 주류를 이루었던 사회사상이 타파되어가는 가운데 자본주의를 수용할 수 있는 사상적 배경을 배태하고 있었는지 알아보고자 한다. 그리고 자본주의를 지향하는 세계사적인 큰 맥락에서 일본이 어떻게 여기에 대응하였는지 살펴보고 조선이 취했던 당시 상황을 정밀 분석함으로서 일본과 우리나라와의 관계를 재정리하고, 지금까지 우리나라의 자본주의 맹아문제를 부분적이고 지엽적인 일본과의 관계에서 탈피하여 자본주의를 지향하는 세계사적인 큰 맥락에서 우리나라의 자본주의 맹아문제를 살펴보고자 하였다.

We carried out basic study on the major odor substances from livestock waste treatment plant to design high efficiency offensive odor treatment facility. We choose Y and G-treatment plants and measured each samples from pre-treatment facility, water treatment facility, sludge treatment facility and offensive odor treatment facility. The odor was mainly produced from pre-treatment facility from above measurements. The concentration of hydrogen sulfide was very high as 1,200 ppm from impurity treatment facility. The concentration of hydrogen sulfide was detected as 100 ppm in waste water treatment facility(aeration facility and head) and 160∼252 ppm in sludgy treatment facility (retaining facility and scum tank). The offensive odor treatment facility was composed of washing tower using NaOCl as washing material and bio-filter. Efficiency of the offensive odor treatment facility on the hydrogen sulfide was 5∼33% and the efficiency on the ammonia was low except Y-treatment facility’s vortex mixer washing tower which is 98%. Reduction efficiency of hydrogen sulfide was increased from 14.7% to 96.3% by changing washing material, NaOH, at Y-treatment facility’s vortex mixer washing tower.

Peripheral nerve injuries are very common in clinics and often result in severe functional deficits. The aim of this study was to evaluate the effect of treadmill running and electro-acupuncture on nerve regeneration and functional recovery of muscle activity following sciatic nerve crush injury in a rat model. A comparative study was conducted over 30 days on 60 adult male Sprague-Dawley rats grouped into sham control (C), electro-acupuncture (EA), treadmill (T), and treadmill plus electro-acupuncture (TEA). The left sciatic nerve was crushed for 30 sec using a hemostatic forceps and functional activity was evaluated with sciatic functional tests, nerve conduct velocity, muscle weight, and histology at 10, 20, and 30 days after injury. Muscle weight was significantly (P<0.05) increased between days 10 and 30 in the TEA group. In histology, the degree of damage was scored as C > TEA > T > EA, although necrosis and fibrosis of muscle was observed only in the TEA group. The EA and TEA groups showed rapid recovery with better myelinated axons on day 10. These results suggest that application of the TEA method with balanced exercise is a useful treatment option for peripheral nerve injury regeneration and muscle activity.

Investigation of the odor source is necessary to establish of the effective counter plan for reducing the odor emitted from the industrial complexes. This study was carried out to investigate the characteristics of the odor emitted from leather manufacturing plants, using three methods which are a direct sensory technique, an air dilution sensory test and a instrumental analysis. Total 7 samples were sampled at 3 points of three factories in this study. As a results of this study, while odor intensity of 7 samples ranges from 2 degree to 4 degree, dilution ration of olfactory test shows the range from 300 to 600. It was estimated that main malodorous compounds ordered hydrogen sulfide, methyl mercaptan, i-valeraldehyde.

본 논문은 독거노인 또는 부정맥 환자의 24시간 응급감시 모니터링을 위해 광소자를 이용한 독거노인 위험감지형 맥박센서를 설계했다. 투과형의 광소자를 사용한 맥박 측정 센서는 상용 기술이지만, 이것은 의료 기관에서 환자나 환자 진료 모니터링을 위한 일회성 측정 방법이다. 때문에 일상생활에서 무구속의 지속적인 측정이 가능한 센서 개발이 필요하며, 또한 내구성과 편의성, 유동성에 대한 신뢰성과 안정성을 유지해야한다. 이러한 조건에서 우리는 손목시계 타입의 독거노인 위험감지형 맥박 센서를 설계하고, 실험 결과에서 그 가능성을 확인했다.