The effect of adding Ca on the microstructural and mechanical properties of as-cast Mg-11Li-3Zn-1Sn(wt%) alloys were investigated. Mg-11Li-3Zn-1Sn-0.4Mn with different Ca additions (0.4, 0.8, 1.2 wt%) were cast under an SF6 and Co2 atmosphere at 720 oC. The cast billets were homogenized at 400 oC for 12h and extruded at 200 oC. The microstructural and mechanical properties were analyzed by OM, XRD, SEM, and tensile tests. The addition of Ca to the Mg-11Li-3Zn-1Sn-0.4Mn alloy resulted in the formation of Ca2Mg6Zn3, MgSnCa intermetallic compound. By increasing Ca addition, the volume fraction and size of Ca2Mg6Zn3 with needle shape were increased. This Ca2Mg6Zn3 intermetallic compound was elongated to the extrusion direction and refined to fine particles due to severe deformation during hot extrusion. The elongation of the 0.8 wt% Ca containing alloy improved remarkably without reduction strength due to the formation of fine grain and Ca2Mg6Zn3 intermetallic compounds by Ca addition. It is probable that fine and homogeneous Ca2Mg6Zn3 intermetallic compounds played a significant role in the increase of mechanical properties.

So far, square concrete filled tubular(CFT) columns have been used in a limited width thickness ratio. The reason is that local buckling occurs in steel tube easily. Once the local buckling occurs, the confinement effect of steel tube on concrete disappears. In this study, we developed welded built-up square steel tube with reinforcement which are placed at the center of the tube width acts as an anchor. 3 specimens of slender welded built-up square CFT columns and 3 specimens of slender welded built-up square steel tube columns were manufactured with parameters of width(B) of steel tube, width thickness ratio(B/t). we conducted a experimental test on the 6 specimens under eccentric load, and evaluated the structural resistance and behavior of 6 specimens.

CFST columns are structurally superior because the concrete inside the steel tubes prevents local buckling at the tubes and the tubes confine the concrete. And, the thickness of steel tube in CFST column has been thinner with development of high-strengh steel. The thinner the steel tube of a square CFST column is, the more local buckling is likely to occur. For this reason, we developed welded built-up square steel tube with stiffeners which are placed at the center of the tube width acts as an anchor. In this study, we conduct experimental test for three specimens of the 4m long span welded built-up square CFT column with parameters of L/D and D/t. And, the test results were compared with the analysis results by M-ϕ-P Program.

목적 : 본 연구는 작업치료사의 직무에 따른 감정노동과 소진 그리고 직무태도의 실태를 분석하고 이에 따 른 각 요인의 집단 간 차이 및 관계를 알아보고자 한다. 연구방법 : 2014년 3월 27일부터 4월 27일까지 설문지를 이용하여, 작업치료사의 일반적 특성, 질병 관 련 특성, 감정노동, 소진, 직무태도에 대해 조사하였다. 대상자의 일반적인 특성은 빈도분석을 하였고, 감 정노동, 소진, 직무태도는 빈도분석 그리고 평균과 표준편차로 산출하였다. 일반적 특성에 따른 감정노 동, 소진, 직무태도의 차이는 t-test와 ANOVA로 분석하였다. 감정노동, 소진, 직무태도와의 상관성은 피어슨 상관분석을 하였고, 관련 요인의 직무태도에 미치는 영향을 알아보기 위해서는 위계다중회귀분석 을 하였다. 결과 : 작업치료사의 감정노동과 소진은 정의 상관관계(r=.477), 감정노동과 직무태도와는 부의 상관관계 (r=-.215), 소진과 직무태도는 부의 상관관계(r=-.449)로 유의한 차이가 있었다. 소진은 직무태도에 부의 방향으로 영향을 미쳤다(F=22.400, Adjusted R2=.19). 결론 : 작업치료사의 감정노동, 소진, 직무태도와의 관련성은 감정노동의 강도가 높아지면 소진이 높아지 고, 직무태도는 낮아지는 것으로 나타났다. 작업치료사의 감정노동과 소진이 직무태도에 미치는 요인은 소진으로, 소진이 적을수록 직무태도는 높게 나타났다.

아프리카 특히 콩고민주공화국의 식량난 해결에 도움이 되는 벼농사 정보를 얻을 목적으로 우리나라 농림나1호를 월평균 강우가 216 mm였던 2012년 10월부터 2013년 2월까지와 32 mm였던 2013년 3월부터 6월까지 총 2회에 걸쳐 킨샤사의 사질 밭에서 심토비닐피복재배하여 생육특성을 조사한 결과는 다음과 같았다. 1. 농림나1호는 심토에 비닐을 피복하여 재배한 것이 자연상태로 재배한 것보다 출수기가 2012년에 2일 늦었고 2013년에는 4일 더 빨랐다. 그리고 2012년과 2013년도의 포기당 경수는 각각 2.1개와 0.2개 더 많았으며 이삭당 립수는 각각 23.4%와 23.1% 증가되었다. 2. 농림나1호의 심토비닐피복재배와 무피복재배구의 평균수량은 춘분 이후에 재배한 2012년도의 시험 벼가 추분무렵에 재배한 2013년도의 시험 벼보다 38.4% 더 많았으며, 심토비닐피복효과는 2012년도 재배 벼에서 8% 더 높았다. 3. 농림나1호는 국내재배에서보다 출수기가 70일 이상 단축되고 천립중이 2 g 이상 감소되면서 심토비닐피복구 기준으로 ha당 쌀수량이 12(2012년도) ~ 38%(2013년도) 가량 적었다. 그러나 등숙률은 12.5% 더 높았다. 4. 농림나1호는 2년간 심토비닐피복과 무피복 상태로 재배했을 때의 평균수량이 현지품종인 IRAT216보다 5.1% 더 높았지만 심토비닐피복처리 효과에 있어서는 IRAT216보다 32.6% 낮았다.

In this research, magnesium powder was prepared by gas atomizing. Refinement behaviors of magnesium powder produced under different conditions were investigated using a mechanical milling (attrition milling) process. Analyses were performed to assess the characterization and comparison of milled powder with different steel ball sizes and milling times. The powders were analyzed by field emission scanning electron microscope, apparent density and powder fluidity. The particle morphology of the Mg powders changed from spherical particles of feed metals to irregular oval particles, then plate type particles, with an increasing milling time. Because of the HCP structure, deformation occurs due to the existence of the easily breakable C-axis perpendicular to the base, which results in producing plate-type powders. An increase in ball size and the impact energy of the magnesium powder maximizes the effect of refinement. Furthermore, it is possible to improve the apparent density and fluidity according to the smoothness of the surface of the initial powder.

Microstructural evolution in the thickness direction of an oxygen free copper processed by accumulative rollbonding (ARB) is investigated by electron back scatter diffraction (EBSD) measurement. For the ARB, two copper alloy sheets 1 mm thick, 30 mm wide and 300 mm long are first degreased and wire-brushed for sound bonding. The sheets are then stacked and roll-bonded by about 50% reduction rolling without lubrication at an ambient temperature. The bonded sheet is then cut to the two pieces of the same dimensions and the same procedure was repeated on the sheets up to eight cycles. The specimen after 1 cycle showed inhomogeneous microstructure in the thickness direction so that the grains near the surface were finer than those near the center. This inhomogeneity decreased with an increasing number of ARB cycles, and the grain sizes of the specimens after 3 cycles were almost identical. In addition, the aspect ratio of the grains decreased with an increasing number of ARB cycles due to the subdivision of the grains by shear deformation. The fraction of grains with high angle grain boundaries also increased with continuing process of the ARB so that it was higher than that of the low angle grain boundaries in specimens after 3 cycles. A discontinuous dynamic recrystallization occurred partially in specimens after 5 cycles.

A powder-in-sheath rolling (PSR) process utilizing a copper alloy tube was applied to a fabrication of a multi-walled carbon nanotube (CNT) reinforced aluminum matrix composite. A copper tube with an outer diameter of 30 mm and a wall thickness of 2 mm was used as a sheath material. A mixture of pure aluminum powders and CNTs with the volume contents of 1, 3, 5 vol% was filled in the tube by tap filling and then processed to 93.3% height reduction by a rolling mill. The relative density of the CNT/Al composite fabricated by the PSR decreased slightly with increasing of CNTs content, but showed high value more than 98%. The average hardness of the 5%CNT/Al composite increased more than 3 times, compared to that of unreinforced pure Al powder compaction. The hardness of the CNT/Al composites was some higher than that of the composites fabricated by PSR using SUS304 tube. Therefore, it is concluded that the type of tube affects largely on the mechanical properties of the CNT/Al composites in the PSR process.

In the study, public facilities in Korea covered by the law, including PC-rooms, child care facilities, bus terminalwaiting rooms, elderly nursing facilities, movie theaters, underground subway stations, super super markets andindoor parking lots (8 types of facility, for a total of 32 locations) were investigated for indoor gas phase PAHsand particulate phase PAHs. PAHs source profiles were investigated as well. Finally, public facilities PAHs wereestimated the main influencing factors and sources of indoor by factor analysis. Underground subway stations andPC-rooms tended to be higher the concentration than other facilities. It judged each the effects of car exhaust,smoking, and elderly nursing facilities, child care facilities, movie theaters, where the influence of the outdoor airis less relatively direct effect that car exhaust and incoming of ambient air, were showed low concentration. Supersuper markets displayed a large amount of different products and bus terminal waiting rooms influenced car exhaustis higher than those that. Sources of indoor PAHs in public facilities make out profiling(cooking process: broilingmeat and fish, incense, shampoo, decorative candles, tobacco) and on the effects of ambient on reported existingliterature(of diesel and gasoline engines, heating fuel, coke oven, a wood combustion) was referred for factor analysisto estimate emission sources. As a result of particulate PAHs phase, three major factors were showed that factor1: cooking, use of gas fuel and combustion devices, factor 2: smoking. Factor 3: car exhaust. Factor analysis resultsof gas PAHs phase are similar to particulate PAHs phase. Additionally, factors such as air fresheners was estimated.

A powder-in-sheath rolling method was applied to a fabrication of a carbon nano tube (CNT) reinforcedaluminum composite. A STS304 tube with an outer diameter of 34 mm and a wall thickness of 2 mm was used as asheath material. A mixture of pure aluminum powders and CNTs with the volume contents of 1, 3, 5 vol was filled inthe tube by tap filling and then processed to 73.5% height reduction by a rolling mill. The relative density of the CNT/Al composite fabricated by the powder-in-sheath rolling decreased slightly with increasing of CNTs content, but exhib-ited high value more than 98. The grain size of the aluminum matrix was largely decreased with addition of CNTs; itdecreased from 24 µm to 0.9 µm by the addition of only 1 volCNT. The average hardness of the composites increasedby approximately 3 times with the addition of CNTs, comparing to that of unreinforced pure aluminum. It is concludedthat the powder-in-sheath rolling method is an effective process for fabrication of CNT reinforced Al matrix composites.

본 연구는 복숭아 유목기에 생육 촉진을 목적으로 질소를 과다 시용하여 동해발생의 우려가 있을 경우 에틸알콜 토양 살포에 의한 수체 내 전분증진과 증가된 전분이 동해에 미치는 영향을 구명하기 위해 수행하였다. 1. 전분함량은 질소 검정시비량 이상 시용에서는 시비량이 많아짐에 따라 감소하였고, 검정시비량의 75% 시용에서도 감 소하는 경향으로 부적절한 질소시비는 전분축적을 저해하였다. 2. 질소가 과다 시용된 복숭아 유목의 전분함량 증진을 위 해서는 9월 5일에 에틸알콜 50 mL를 토양 투입하는 것이 전 분함량을 가장 많이 증가시키는 효과적인 추비방법이었다. 3. 월동 전에 저온지역인 제천과 평창지역으로 수체를 이동 시켜 청원지역의 수체와 비교한 결과 4월 하순의 전분함량은 평창 >제천 >청원 순으로 높았다. 이는 평창지역은 12월 하 순 ~ 1월 상순, 제천지역은 2월 상순에 동해를 받아 전분이 당 으로 전환되어 세포의 결빙을 억제하는 기작이 원활하지 않았 기 때문이라고 판단되었다. 4. 질소 25% 이상 증비된 처리에 에틸알콜을 토양에 살포 하였을 때 동해경감 효과가 있었고, 월동 전 전분함량과 꽃눈동해와는 고도로 유의성 있는 부의 상관관계가 있었다.

본 연구는 드릴을 이용하여 화분 공급이 용이한 위치에 수 분용 품종을 편리하게 접목시키는 적기 구명을 목적으로 접목 된 수분용 품종들의 생육특성을 검토하여 동해에 강하고, 다량의 화분을 공급하는 수분용 품종 선발로 이어지는 일련의 연 구를 통해 반영구 안전착과 기술을 확립하기 위해 수행하였다. 1. 드릴을 이용한 접목 유합율은 3월 13일에 40.0 ~ 44.5% 로 가장 높았고, 접목시기가 늦어짐에 따라 감소하였으며, 품 종에 따른 접목 유합율의 차이는 없었다. 2. 가지의 길이는 3월 13일 접목에서 길었고, 품종간에는 수미와 이즈미백도가 짧았다. 화아 수도 3월 13일 접목에서 많 았고, 품종간에는 수미와 이즈미백도가 적었다. 3. 엽 중 질산태질소 함량은 수미와 이즈미백도가 낮았고, 기타 품종은 비슷하였다. SPAD 값과 엽 중 질산태질소 함량 은 비슷한 경향으로 수미와 이즈미백도가 낮았고, 기타 품종 들은 차이가 없었다. 4. 가지 전분 함량은 월동 전에는 이즈미백도가 가장 적었 고, 기타 품종은 비슷하였다. 월동 후에는 장택백봉과 진미가 높았고, 기타 품종은 차이가 없었다. 월동 후와 월동 전의 가 지 전분함량의 비율은 유명과 천홍이 낮았고, 기타 품종은 비 슷한 경향이었다. 5. 접목된 수분용 품종의 화아 동해 비율은 수미와 진미가 21.7 ~ 23.1%로 높았고, 유명과 천홍은 9.4 ~ 12.5%로 낮았으 며, 기타 품종은 17.6 ~ 19.4%였다. 수술 당 화아 수는 유명과 진미가 많았고, 이즈미백도가 가장 적었다. 이상의 결과를 종 합하면 접목 후 생장은 중간 정도이지만 동해에 강하고, 화아 수가 많은 유명이 최근 월동 중 이상저온에 적합한 수분용 품 종으로 유망하였다.

A powder in sheath rolling method was applied to the fabrication of a carbon nano tube (CNT) reinforced aluminum composite. A 6061 aluminum alloy tube with outer diameter of 31 mm and wall thickness of 2 mm was used as a sheath material. A mixture of pure aluminum powder and CNTs with a volume content of 5% was filled in the tube by tap filling and then processed to an 85% reduction using multi-pass rolling after heating for 0.5 h at 400˚C. The specimen was then further processed at 400˚C by multi-pass hot rolling. The specimen was then annealed for 1 h at various temperatures that ranged from 100 to 500˚C. The relative density of the 5vol%CNT/Al composite fabricated using powder in sheath rolling increased with increasing of the rolling reduction, becoming about 97% after hot rolling under 96 % total reduction. The relative density of the composite hardly changed regardless of the increasing of the annealing temperature. The average hardness also had only slight dependence on the annealing temperature. However, the tensile strength of the composite containing the 6061 aluminum sheath decreased and the fracture elongation increased with increasing of the annealing temperature. It is concluded that the powder in sheath rolling method is an effective process for fabrication of CNT reinforced Al matrix composites.

A two-pass differential speed rolling(DSR) was applied to a deoxidized low-phosphorous copper alloy sheet in order to form a homogeneous microstructure. Copper alloy with a thickness of 3 mm was rolled to 75 % reduction by two-pass rolling at 150˚C without lubrication at a differential speed ratio of 2.0:1. In order to introduce uniform shear strain into the copper alloy sheet, the second rolling was performed after turning the sample by 180˚ on the transverse direction axis. Conventional rolling(CR), in which the rotating speeds of the upper roll and lower roll are identical to each other, was also performed by two-pass rolling under a total rolling reduction of 75 %, for comparison. The shear strain introduced by the conventional rolling showed positive values at positions of the upper roll side and negative values at positions of the lower roll side. However, samples processed by the DSR showed zero or positive values at all positions. 100//ND texture was primarily developed near the surface and center of thickness for the CR, while 110//ND texture was primarily developed for the DSR. The difference in misorientation distribution of grain boundary between the upper roll side surface and center regions was very small in the CR, while it was large in the DSR. The grain size was smallest in the upper roll side region for both the CR and the DSR. The hardness showed homogeneous distribution in the thickness direction in both CR and DSR. The average hardness was larger in CR than in DSR.

본 연구는 복숭아 품질의 핵심인 당도 향상을 위해 토양미생물의 영양원으로 에틸알콜을 투입하여 활성을 촉진시키고, 이들의 질소섭식 증가가 복숭아 수체로의 질소흡수를 제어하여 과중 감소 없이 당도를 향상시키는 최적의 에틸알콜 투입량을 구명하기 위해 수행하였다. 1. 토양 중 질산태질소의 함량은 에틸알콜 투입량 250ml에서는 12일, 500ml는 16일, 1,000ml는 24일 그리고 2,000ml는 29일간 적어 투입량이 증가할수록 질산태질소의 제어 기간이 길었다. 2. 엽 중 질소 함량은 무처리에 비해 첫 수확일인 9월 19일에는 에틸알콜 500 ml 이상 투입에서 적었고, 9월 25일과 10월 1일 수확에서는 1,000 ml 이상 투입에서 적었다. 3. 토양의 biomass C는 에틸알콜 투입 후 7일에서 26일 사이에 투입량 250 ml에서는 342 ~ 356 mg/kg, 500 ml는 431 ~453 mg/kg, 1,000 ml는 503~521 mg/kg일 그리고 2,000 ml는610 ~ 625 mg/kg로 유지되어 무처리에 비하여 증가되었고, 투입량이 많아짐에 증가량이 많아졌다. 4. Dehydrogenase 활성은 에틸알콜 250 ml 투입에서는 9월14일, 500 ml 투입은 9월 21일, 1,000 ml 투입은 9월 27일이후 감소하는 경향이었으며, 2,000 ml 투입에서는 10월 3일까지 활성이 지속되었다. 5. 과중은 에틸알콜 2,000 ml 투입에서 9월 25일 이후 수확시 감소되었지만, 1,000 ml 투입에서는 모든 수확시기에서 과중 감소 없이 당도가 증가되었다.

The microstructural evolution of AA1050/AA6061 complex aluminum alloy, which is fabricated using an accumulative roll-bonding (ARB) process, with the proceeding of ARB, was investigated by electron back scatter diffraction (EBSD) analysis. The specimen after one cycle exhibited a deformed structure in which the grains were elongated to the rolling direction for all regions in the thickness direction. With the proceeding of the ARB, the grain became finer; the average grain size of the as received material was 45μm; however, it became 6.3μm after one cycle, 1.5μm after three cycles, and 0.95μm after five cycles. The deviation of the grain size distribution of the ARB processed specimens decreased with increasing number of ARB cycles. The volume fraction of the high angle grain boundary also increased with the number of ARB cycles; it was 43.7% after one cycle, 62.7% after three cycles, and 65.6% after five cycles. On the other hand, the texture development was different depending on the regions and the materials. A shear texture component 001<110> mainly developed in the surface region, while the rolling texture components 011<211> and 112<111> developed in the other regions. The difference of the texture between AA1050 and AA6061 was most obvious in the surface region; 001<110> component mainly developed in AA1050 and 111<110> component in AA6061.

The microstructure and mechanical properties of a copper alloy sheet processed by differential speed rolling (DSR) were investigated in detail. A copper alloy with thickness of 3 mm was rolled to a 50% reduction at ambient temperature without lubrication and with a differential speed ratio of 2.0:1. For comparison, conventional rolling (CR), in which the rolling speeds of the upper and lower rolls is 2.0 m/min, was also performed under the same rolling conditions. The shear strain of the sample processed by CR showed positive values at the positions of the upper roll side and negative values at the positions of the lower roll side. On the other hand, the sample processed by the DSR showed zero or positive shear strain values at all positions. However, the microstructure and mechanical properties of the as-rolled copper alloys did not show such significant differences between the CR and the DSR. The samples rolled by the CR and the DSR exhibited a typical deformation structure. In addition, the DSR processed samples showed a typical rolling texture in which 112<111>, 011<211> and 123<634> components were developed at all positions. Therefore, it is concluded that the DSR was very effective for the introduction of a uniform microstructure throughout the thickness of the copper alloy.

We previously prepared a standardized and purified extract of Salvia miltiorrhiza, PF2401-SF, and showed that it protected against hepatic injury more effectively than ethanol based extraction. In this study, we determined the hepatoprotective mechanisms of PF2401-SF in vivo. Hepatic injury was induced in mice by using carbon tetrachloride (CCl4). Treatment with PF2401-SF (1 or 10 mg/kg, p.o.) significantly reduced the levels of alanine transaminase (ALT) and aspartate transaminase (AST) in the plasma. PF2401-SF treatment resulted in further elevation of the CCl4-induced heme oxygenase-1 (HO-1) expression, which contributed to the PF2401-SF-mediated liver protection. Additionally, PF2401-SF treatment significantly reduced the c-Jun NH2-terminal kinase (JNK) phosphorylation induced by CCl4. Taken together, these results suggest that the protective effect of PF2401-SF, a standardized fraction of S. miltiorrhiza, against CCl4-induced hepatic injury in mice arises from its induction effect on HO-1 and inhibitory effect on JNK phosphorylation.

A sample of ultra low carbon IF steel was processed by six-layer stack accumulative roll-bonding (ARB) and annealed. The ARB was conducted at ambient temperature after deforming the as-received material to a thickness of 0.5 mm by 50% cold rolling. The ARB was performed for a six-layer stacked, i.e. a 3 mm thick sheet, up to 3 cycles (an equivalent strain of ~7.0). In each ARB cycle, the stacked sheets were, first, deformed to 1.5 mm thickness by 50% rolling and then reduced to 0.5 mm thickness, as the starting thickness, by multi-pass rolling without lubrication. The specimen after 3 cycles was then annealed for 0.5 h at various temperatures ranging from 673 to 973 K. The microstructural evolution with the annealing temperature for the 3-cycle ARB processed IF steel was investigated in detail by transmission electron microscopy observation. The ARB processed IF steel exhibited mainly a dislocation cell lamella structure with relatively high dislocation density in which the subgrains were partially observed. The selected area diffraction (SAD) patterns suggested that the misorientation between neighboring cells or subgrains was very small. The thickness of the grains increased in a gradual way up to 873 K, but above 898 K it increased drastically. As a result, the grains came to have an equiaxed morphology at 898 K, in which the width and the thickness of the grains were almost identical. The grain growth occurred actively at temperatures above 923 K.