One-dimensional MgO nanostructures with various morphologies were synthesized by a thermal evaporation method. The synthesis process was carried out in air at atmospheric pressure, which made the process very simple. A mixed powder of magnesium and active carbon was used as the source powder. The morphologies of the MgO nanostructures were changed by varying the growth temperature. When the growth temperature was 700 °C, untapered nanowires with smooth surfaces were grown. As the temperature increased to 850 °C, 1,000 °C and 1,100 °C, tapered nanobelts, tapered nanowires and then knotted nanowires were sequentially observed. X-ray diffraction analysis revealed that the MgO nanostructures had a cubic crystallographic structure. Energy dispersive X-ray analysis showed that the nanostructures were composed of Mg and O elements, indicating high purity MgO nanostructures. Fourier transform infrared spectra peaks showed the characteristic absorption of MgO. No catalyst particles were observed at the tips of the one-dimensional nanostructures, which suggested that the one-dimensional nanostructures were grown in a vapor-solid growth mechanism.

최근 경영환경은 경쟁적인 분위기로 변화되었고, 불확실성의 증대에 따라 성과 중심의 경영시스템을 구축해 조직 내 경쟁체제를 도입해 왔다. 국내 기업의 성과주의 시스템 도입으로 인하여 구성원들의 직무 불안정성 증가에 따른 조직상황이나 문화를 고려할 때, 경쟁분위기의 심화에 따라 발생할 수 있는 개인 수준의 결과들을 살펴봄으로써 이에 대한 심도 깊은 연구와 대처 방안이 요구되고 있다. 본 연구는 개인 의 경쟁특성이 직무성과 및 정서적 탈진에 미치는 효과와 이들 간의 관계에 경쟁분위기의 조절 효과를 검증함으로써 인적자원관리 연구의 이론적 확장과 더불어 실무적인 시사점을 제공하고자 하였다. 가설검 증을 위해 국내 기업의 205명의 구성원들을 대상으로 한 설문자료를 분석하였다. 가설검증 결과 첫째, 경 쟁특성은 직무성과에 정(+)의 영향을 미치는 것으로 나타났다. 둘째, 경쟁특성은 정서적 탈진에 영향을 미치지 않는 것으로 나타났다. 셋째, 경쟁특성과 직무성과, 정서적 탈진 간의 관계에 있어서 경쟁특성과 경쟁분위기의 상호작용은 정서적 탈진에만 영향을 미치는 것으로 나타났다. 구체적으로, 경쟁분위기가 높 을 경우에 경쟁특성이 정서적 탈진에 미치는 영향력은 증폭 되어지는 것으로 나타났다. 연구결과를 토대로 연구의 한계점과 향후 연구과제를 제시하였다.

The synthesis of porous W by freeze-casting and vacuum drying is investigated. Ball-milled WO3 powders and tert-butyl alcohol were used as the starting materials. The tert-butyl alcohol slurry is frozen at –25oC and dried under vacuum at –25 and –10oC. The dried bodies are hydrogen-reduced at 800oC and sintered at 1000oC. The XRD analysis shows that WO3 is completely reduced to W without any reaction phases. SEM observations reveal that the struts and pores aligned in the tert-butyl alcohol growth direction, and the change in the powder content and drying temperature affects the pore structure. Furthermore, the struts of the porous body fabricated under vacuum are thinner than those fabricated under atmospheric pressure. This behavior is explained by the growth mechanism of tert-butyl alcohol and rearrangement of the powders during solidification. These results suggest that the pore structure of a porous body can be controlled by the powder content, drying temperature, and pressure.

Cr thin films with O added are deposited on sapphire substrate by DC sputtering and are nitrided in NH3 atmosphere between 300 and 900 oC for various times. X-ray diffraction results show that nitridation begins at 500 oC, forming CrN and Cr2N. Cr oxides of Cr2O3 are formed at 600 oC. And, at temperatures higher than 900 oC, the intermediate materials of Cr2N and Cr2O3 disappear and CrN is dominant. The atomic concentration ratios of Cr and O are 77% and 23%, respectively, over the entire thickness of as-deposited Cr thin film. In the sample nitrided at 600 oC, a CrN layer in which O is substituted with N is formed from the surface to 90 nm, and the concentrations of Cr and N in the layer are 60% and 40%, respectively. For this reason, CrN and Cr2N are distributed in the CrN region, where O is substituted with N by nitridation, and Cr oxynitrides are formed in the region below this. The nitridation process is controlled by inter-diffusion of O and N and the parabolic growth law, with activation energy of 0.69 eV.

This study was conducted for the purpose of suggesting a standard that can be used under ambient temperature by improving the low mechanical and thermal properties of ABS. PC was used as a filler, and post-curing conditions of the ABS/PC blend injection material were investigated. It was found that the ABS/PC blend injection material having a PC content of 20 wt.% or more showed little change in tensile properties at a temperature of 50°C, and a decrease in tensile properties of less than 10% at 80°C.

본 연구는 국내 은행업 종사자들을 대상으로 비윤리적 친조직 행동에 미치는 선행요인에 관한 연구를 통해 비윤리적 친조직 행동의 발생 및 조절기제를 분석하고자 한다. 이를 위해 인지된 실적 중시 분위기가 도덕적 이탈, 비윤리적 친조직 행동에 미치는 직접효과와 도덕적 이탈의 인지된 실적 중시 분위기와 비윤리적 친조직 행동 간의 매개효과, 상사의 도덕적 역량의 인지된 실적 중시 분위기와 도덕적 이탈 간의 조절효과를 실증적으로 검증하고자 하였다. 본 연구를 위해 국내 은행 영업점에 종사하는 팀장·부지점 장급 이하 정규직원을 대상으로 설문조사를 진행하였다. 최종 438부의 설문자료를 바탕으로 SPSS 25를 활용하여 실증분석하였다. 분석결과, 첫째, 인지된 실적 중시 분위기는 도덕적 이탈, 비윤리적 친조직 행동에 대해 정(+)의 방향으로 유의하였다. 둘째, 도덕적 이탈은 인지된 실적 중시 분위기와 비윤리적 친조직 행동 간의 관계를 정(+)의 방향으로 매개하였다. 셋째, 가설과 달리, 상사의 도덕적 역량은 인지된 실적 중시 분위기와 비윤리적 친조직 행동 간의 관계를 정(+)의 방향으로 조절하였다. 결론에서는 연구결과 요약과 연구의 의의와 시사점, 한계점과 향후 연구과제를 제시하였다.

본 연구는 프로젝트 팀장의 기업가적 리더십이 부하의 혁신행동에 미치는 영향을 규명하고, 조직의 혁 신분위기가 상사의 기업가적 리더십과 혁신행동 사이의 관계를 매개하는지를 밝히고자 하였다. 기업가적 리더십이 혁신분위기를 조성함으로써 연구개발 프로젝트에 소속된 팀원의 혁신행동을 이끌어냄을 실증하였다. 실증연구를 위한 자료는 국내 5개 조직의 연구개발 프로젝트 팀원 225명을 대상으로 설문조사를 하였고, 최종 분석에는 166명의 설문자료를 이용하였다. 본 연구의 분석결과를 살펴보면, 기업가적 리더십은 혁신행동에 유의한 정의 영향을 미치고 있는 것으로 나타났다. 그리고 혁신분위기는 기업가적 리더십과 혁신행동 간의 관계를 완전 매개하고 있는 것으로 나타났다. 즉, 기업가적 리더십은 연구개발 프로젝트 팀의 혁신분위기를 통해서만 혁신행동을 유발하였다. 연구결과를 토대로 연구의 시사점과 한계점 및 향후 연구과제를 제시하였다.

본 연구는 고성과작업체제가 조직 내 모성보호분위기를 향상하는 지를 노동연구원의 사업체 패널 자료를 통해 실증적으로 분석하였다. 1차년도(2005년)부터 6차년도(2015년)까지 모두 응답한 100인 이상 고 용규모의 사업체들이 형성한 균형패널자료를 추출하여 이를 표본으로 하고 고정효과모델, 확률효과 모델, 그리고 개체별 특이성과 시간대별 특이성 등을 함께 통제한 이원고정효과 모델 등으로 분석하여 그 결과를 제시하였다. 종속변수로써는 조직내 공식적으로 도입하고 있는 ‘모성보호 관행의 수’와 ‘실제로 잘 수행되고 있는 모성보호 관행의 수(모성보호관행활성정도)’를 도입하였고 고성과 작업체제의 지수를 산출해 독립변인으로 투입하였다. 분석결과, 위 3개 분석 모델 모두에서 고성과 작업체제는 조직 내 모성보호 분위기를 증가시키는 것으로 나타났다. 특히 개체별 특이성과 시간별 특이성을 통제한 이원고정효과 결과에서는 2005년이후 지속적으로 조직내 모성보호분위기가 향상되어 왔을 뿐 아니라 고성과작업체제지수가 증가할수록 조직내 모성보호분위기는 향상되는 것으로 분석되었다. 이 결과의 의미는 고성과 작업 체제의 이념적 논쟁의 맥락에서 새롭게 해석될 수 있다. 즉 고성과 작업체제에 대한 긍정적인 입장과 비판론적인 입장에서의 논쟁에서 본 연구결과는 긍정적인 입장을 지지하는 결과를 보여준다. 정교하고 합리적인 인적자원관리체제는 조직 내 모성보호 분위기를 향상함으로써 조직과 구성원간의 상호호혜적인 관계를 형성할 수 있다는 것을 확인할 수 있다. 마지막으로 분석 결과의 시사점과 한계점, 그리고 미래의 연구 방향 등에 대해 제시하였다.

The hydrogen reduction behavior of MoO3-CuO powder mixture for the synthesis of homogeneous Mo-20 wt% Cu composite powder is investigated. The reduction behavior of ball-milled powder mixture is analyzed by XRD and temperature programmed reduction method at various heating rates in Ar-10% H2 atmosphere. The XRD analysis of the heat-treated powder at 300oC shows Cu, MoO3, and Cu2MoO5 phases. In contrast, the powder mixture heated at 400oC is composed of Cu and MoO2 phases. The hydrogen reduction kinetic is evaluated by the amount of peak shift with heating rates. The activation energies for the reduction, estimated by the slope of the Kissinger plot, are measured as 112.2 kJ/mol and 65.2 kJ/mol, depending on the reduction steps from CuO to Cu and from MoO3 to MoO2, respectively. The measured activation energy for the reduction of MoO3 is explained by the effect of pre-reduced Cu particles. The powder mixture, hydrogen-reduced at 700oC, shows the dispersion of nano-sized Cu agglomerates on the surface of Mo powders.

The present study demonstrates the effect of raw powder on the pore structure of porous W-Ni prepared by freeze drying of camphene-based slurries and sintering process. The reduction behavior of WO3 and WO3-NiO powders is analyzed by a temperature programmed reduction method in Ar-10% H2 atmosphere. After heat treatment in hydrogen atmosphere, WO3- NiO powder mixture is completely converted to metallic W without any reaction phases. Camphene slurries with oxide powders are frozen at −30 oC, and pores in the frozen specimens are generated by sublimation of the camphene during drying in air. The green bodies are hydrogen-reduced at 800 oC and sintered at 1000 oC for 1 h. The sintered samples show large and aligned parallel pores to the camphene growth direction, and small pores in the internal wall of large pores. The strut between large pores, prepared from pure WO3 powder, consists of very fine particles with partially necking between the particles. In contrast, the strut densification is clearly observed in the Ni-added W sample due to the enhanced mass transport in activation sintering.

Evaluation of the durability and stability of materials used in power plants is of great importance because parts or components for turbines, heat exchangers and compressors are often exposed to extreme environments such as high temperature and pressure. In this work, high-temperature corrosion behavior of 316 L stainless steel in a carbon dioxide environment was studied to examine the applicability of a material for a supercritical carbon dioxide Brayton cycle as the next generation power plant system. The specimens were exposed in a high-purity carbon dioxide environment at temperatures ranging from 500 to 800 oC during 1000 hours. The features of the corroded products were examined by optical microscope and scanning electron microscope, and the chemical compound was determined by x-ray photoelectron spectroscopy. The results show that while the 316 L stainless steel had good corrosion resistance in the range of 500-700 oC in the carbon dioxide environment, the corrosion resistance at 800 oC was very poor due to chipping the corroded products off, which resulted in a considerable loss in weight.

The effects of the heat treatment temperature and of the atmosphere on the dehydrogenation and hydrogen reduction of ball-milled TiH2-WO3 powder mixtures are investigated for the synthesis of Ti-W powders with controlled microstructure. Homogeneously mixed powders with refined TiH2 particles are successfully prepared by ball milling for 24 h. X-ray diffraction (XRD) analyses show that the powder mixture heat-treated in Ar atmosphere is composed of Ti, Ti2O, and W phases, regardless of the heat treatment temperature. However, XRD results for the powder mixture, heat-treated at 600oC in a hydrogen atmosphere, show TiH2 and TiH peaks as well as reaction phase peaks of Ti oxides and W, while the powder mixture heat-treated at 900oC exhibits only XRD peaks attributed to Ti oxides and W. The formation behavior of the reaction phases that are dependent on the heat treatment temperature and on the atmosphere is explained by thermodynamic considerations for the dehydrogenation reaction of TiH2, the hydrogen reduction of WO3 and the partial oxidation of dehydrogenated Ti.

An optimum route to synthesize Ti-Mo system powders is investigated by analyzing the effect of the heat treatment atmosphere on the formation of the reaction phase by dehydrogenation and hydrogen reduction of ball-milled TiH2-MoO3 powder mixtures. Homogeneous powder mixtures with refined particles are prepared by ball milling for 24 h. XRD analysis of the heat-treated powder in a hydrogen atmosphere shows TiH2 and MoO3 peaks in the initial powders as well as the peaks corresponding to the reaction phase species, such as TiH0.7, TiO, MoO2, Mo. In contrast, powder mixtures heated in an argon atmosphere are composed of Ti, TiO, Mo and MoO3 phases. The formation of reaction phases dependent on the atmosphere is explained by the partial pressure of H2 and the reaction temperature, based on thermodynamic considerations for the dehydrogenation reaction of TiH2 and the reduction behavior of MoO3.

As precursors of cathode materials for lithium ion batteries, Ni1/3Co1/3Mn1/3(OH)2 powders are prepared in a continuously stirred tank reactor via a co-precipitation reaction between aqueous metal sulfates and NaOH in the presence of NH4OH in air or nitrogen ambient. Calcination of the precursors with Li2CO3 for 8 h at 1,000°C in air produces dense spherical cathode materials. The precursors and final powders are characterized by X-ray diffraction (XRD), scanning electron microscopy, particle size analysis, tap density measurement, and thermal gravimetric analysis. The precursor powders obtained in air or nitrogen ambient show XRD patterns identified as Ni1/3Co1/3Mn1/3(OH)2. Regardless of the atmosphere, the final powders exhibit the XRD patterns of LiNi1/3Co1/3Mn1/3O2 (NCM). The precursor powders obtained in air have larger particle size and lower tap density than those obtained in nitrogen ambient. NCM powders show similar tendencies in terms of particle size and tap density. Electrochemical characterization is performed after fabricating a coin cell using NCM as the cathode and Li metal as the anode. The NCM powders from the precursors obtained in air and those from the precursors obtained in nitrogen have similar initial charge/discharge capacities and cycle life. In conclusion, the powders co-precipitated in air can be utilized as precursor materials, replacing those synthesized in the presence of nitrogen injection, which is the usual industrial practice.

This current research investigated whether job stress mediates the relationship between physical environment and safety behavior of members in organization. Furthermore, we hypothesized that safety climate functions as moderator between physical environment-job stress link. In order to examine the hypotheses, 870 employees in various fields of companies were sampled. Using structural equation modeling(SEM), we conducted moderated mediation model analysis which cab elaborately test the significance of our hypotheses. The results showed that job stress mediated the link between physical environment and safety behavior of members. Moreover, the relationship between physical environment and job stress was moderated by safety climate. The implications and limitations of our study and suggestions for future research were discussed.

This paper reviewed the effect of job burnout on safety outcomes, and the moderating effect of safety climate in Korean Air Force. The prevalence of burnout in air force pilots has not been determined and reviewed. It is also unknown whether pilots’ burnout may affect their safety outcomes(safety action & compliance). The primary objective of this study was to determine the prevalence of burnout and it’s effect on safety outcomes. For cross-sectional survey, 910 questionnaires were sent to pilots in air force, and 722 questionnaires among them were returned effectively. The questionnaire was divided into 4 parts examining pilots’ demographic factors, job burnout, safety outcomes, and safety climates. To test and review proposed hypotheses, hierarchical multiple regression analysis was used. The results of statistical analysis appeared as follow; 1) EE(emotional exhaustion) and RPA(reduced personal accomplishment) effected negatively on safety action. 2) EE and RPA effected negatively on safety compliance. 3) EE effected more positively on safety action in higher SS(superior support) group than in lower SS group. 4) RPA effected more positively on safety compliance in higher SS(superior support) group than in lower SS group. 5) RPA effected more positively on safety action in higher CW(coworker support) group than in lower CW group.