In this paper, nitrogen (N)-doped ultra-porous carbon derived from lignin is synthesized through hydrothermal carbonization, KOH activation, and post-doping process for CO2 adsorption. The specific surface areas of obtained N-doped porous carbons range from 247 to 3064 m2/g due to a successful KOH activation. N-containing groups of 0.62–1.17 wt% including pyridinic N, pyridone N, pyridine-N-oxide are found on the surface of porous carbon. N-doped porous carbon achieves the maximum CO2 adsorption capacity of 13.6 mmol/g at 25 °C up to 10 atm and high stability over 10 adsorption/desorption cycles. As confirmed by enthalpy calculation with the Clausius–Clapeyron equation, an adsorption heat of N-doped porous carbon is higher than non-doped porous carbon, indicating a role of N functionalities for enhanced CO2 adsorption capability. The overall results suggest that this carbon has high CO2 capture capacity and can be easily regenerated and reused without any clear loss of CO2 adsorption capacity.

국내 고층 아파트의 구조시스템은 크게 다수의 벽체가 분산적으로 배치되어 있는 내력벽 시스템과 중앙 코어벽 시스템으 로 구분할 수 있다. 각각 시스템에 따른 횡방향 거동을 분석하기 위해 본 연구는 국내 고층 아파트 중 대표적인 평면을 갖는 대상 건물을 선정하고, 비선형 정적해석을 수행하여 붕괴메커니즘을 살펴보았다. 비선형 정적해석을 통해 도출된 힘-변위 관계로부터 지진응답에 있어서 중요한 요소인 초과강도계수 및 연성도계수를 산정하여 반응수정계수를 평가하였다. 중앙 코어벽 시스템은 연성도는 작지만, 풍하중에 의해 지배되어 초과강도가 크게 산정돼 초과강도계수에 의해 반응수정계수가 산정되었고, 내력벽 시스템은 벽량이 많아 연성도가 크기 때문에 상당힌 큰 반응수정계수가 산정된다.

The push-out tests have been conducted on the specimens which consist of the steel beam with U-shape section and the continuous cap-type shear connector. Existing formulas for the elevation of shear connector capacity were investigated on the basis of test results. The shear capacities of continuous cap-type shear connectors distinctly declined as the diameters of side-hole in the shear connector increased. The rebars through side-hole for the transverse reinforcement improved the shear capacity of continuous cap-type connector by 20 to 30 percent. It was not feasible to obtain the appropriate capacity values of continuous cap-type shear connectors made of thin steel plate like those of in this study, using the existing formulas. The new formula for reflecting the shear strength of penetrative bars was proposed based on the shear equation of Eurocode 4. The slip capacities of continuous cap-type shear connectors were shown to exceed the limit value of 6mm for the sufficiently ductile behavior.

This study was conducted to propose an effective port operation method in terms of the design capacity of waiting anchorage by comparing the ratio and the number of waiting anchorage according to the port operation method of Busan New Port. For this, the Arena simulation program compared the rates of waiting vessels according to the application of the multi-user terminal, liner terminal and hybrid liner terminal operation methods. As a result, analysis suggested the necessary anchorage space can be reduced to about 18 % when using the multi-user terminal operation method and about 15.6 % when using the hybrid liner terminal operation method, as compared with the liner terminal operation method. Specifically, it was effective to apply the multi-user terminal operation method in terms of the anchorage capacity to be designated to Busan New Port. This study can apply to the designation of the new anchorage in the Busan New Port by reflecting the contents of the design of the anchorage in accordance with the port operation method.

본 연구는 자원준거관점에서 주장하는 기업들의 외부 지식을 배우려는 행동에서는 한계점이 존재한다는 것을 고려하며 기업들이 최종적으로 지양하는 기업성과를 늘리기 위해서는 기업의 흡수역량이 중요하다는 점을 주장하고 있다. 기업들의 외부 정보를 받아들이는 행동으로 본 연구는 인수합병(M&A)을 선택하였으며, 미국 기업에서의 국내 및 해외로의 인수를 알아보았다. 본 연구에서는 기업의 흡수역량이 높을수록 외부 지식을 흡수한 후 기업의 성과가 더 높아질 것으로 보았으며, 이후 기업성과를 더 높일 수 있는 두 조절변수를 이용하였다. 본 연구가 제시하는 가설을 검증하기 위해 기업의 인수합병 데이터는 SDC Platinum에서 39,734개를 확보했으며 이 중, 측정 가능한 기업 정보 데이터는 WRDS Compustat에서 추출해 최종적으로 324개를 표본으로 선정하였다. 가설의 분석방법은 연도를 통제한 선형회귀를 시행하였으며 가설로 제시된 흡수역량과 Tobin’s Q의 관계를 포함한 과거 M&A 경험 및 전략적 자산의 조절효과 모두 유의한 것으로 나타났다. 조절효과로 살펴본 인수기업의 과거 M&A경험은 인수기업의 흡수역량과 재무성과의 긍정적인 관계를 조절하는 것으로 나타났으며, 피인수 기업의 전략적 자산도 인수기업의 흡수역량과 재무성과의 긍정적 관계를 조절하는 것으로 나타났다. 따라서 본 연구의 결과는 선진국에 있는 다국적 기업(인수자)이 흡수역량을 기르는 것은 향후 해외에 위치하는 피인수 기업을 물색 하면서 도움이 되지만 실질적으로 재무성과에도 영향을 미치며, 과거 인수합병 경험과 피인수 기업이 가지는 전략적 자산의 크기에 따라 그 효과가 조절된다는 것을 발견하였다.

In this study, the cooling capacity and the pressure drop of a condenser for 10kW refrigerator unit were experimentally investigated. The performance characteristics of the condenser was studied by changing the fin shape(4 types), fin pitch(5 types), tube row(4 types) and air flow rate(6 types), using the calorimeter. The optimum heat exchanger specifications were selected by comparing the capacity and the pressure drop of the condenser. In order to select the heat exchanger suitable for the condenser for 10kW refrigerator unit, both the cooling capacity and the pressure drop should be considered. From the condenser performance test by pin type, the wavy pin was selected. The optimal performance of the condenser for 10kW refrigerator unit was observed at the fin pitch of 3 mm, the tube row of 4 row, and the air flow rate of 90㎥/min.

국문 우주항공 분야에서 널리 쓰이고 있는 하이드라진[hydrazine, N2H4]은 로켓연료로 사용되는 대표적인 추진제이지만 환경에 유해하고 독성이 강하다는 단점이 존재한다. 따라서 친환경적이고 독성 이 적은 추진제가 다양하게 개발되고 있다. 본 연구에서는 수산화아민[hydroxylamine, NH2OH]을 출발물질로 하여, 질산[nitric acid, HNO3]과 산-염기 반응을 통해 얻어지는 친환경 추진제 HAN [hydroxylammonium nitrate, NH3OHNO3]의 물리 화학적 특성에 대하여 적외선분광법을 이용하여 합성물의 조성, 화학구조 및 작용기를 관찰하였고, 열중량분석을 통해 HAN의 분해온도를 확인하였다. 이온 크로마토그래피를 통해 합성한 HAN에 함유되어 있는 질산이온의 함량을 측정하였다. 즉, N-H와 N-O의 IR peak가 3161 cm-1와 1324 cm-1에서 각각 나타나는 것을 통해 생성한 화합물이 HAN임을 확인하였고, pH 5-7 근처에서 합성한 HAN은 분해온도가 120-140℃인 반면, pH 8 정도인 HAN은 분해온도가 14 0℃ 이상임을 알 수 있었다. 한편, pH 6-7 사이에서 HAN을 합성하였을 때, 가장 높은 질산이온의 농도는 70%인 것으로 나타났다.

This is a descriptive case study of the capacity building program in the field of climate change cooperation achieved by UNITAR Jeju Cifal and GTC(Green Technology Center). The study included the GTC's expertise in climate technology and the UNITAR's collaboration program, an international training body in the environment, peace and security. First, in this study, the results of the satisfaction survey of the education and training in 2017 were analyzed. Education demand for climate change adaptation was shown to be high, and technology demand needed in developing countries was found to be the highest demand for ecosystem monitoring/restoration. Second, an analysis of the program for 2018 showed that South Korea's Eco-city project case is also worth referring to Asian Pacific countries. It was also found that exchanges and discussion activities among participants were more helpful than simple lectures. Meanwhile, development of city-share programs, including self-evaluation, was found to be necessary. Finally, we discussed ways to improve the city-share program in UNITAR. Sharing urban information among peers in this program is beneficial. However, it is necessary to plan programs that have a prior understanding of the culture and background of participants. And it is also important for participants to follow up on their own goals by setting up action plans and checking them after training. It is also necessary to make it clear to participants that there is an organic connection at each stage of the program. That way, participants will set up and plan problems in the climate technology sector of their own country or city, and the effect of education and training will be even greater.

This study investigates the effect of thermo-mechanical treatment on the damping capacity of the Fe-20Mn-12Cr- 3Ni-3Si alloy with deformation induced martensite transformation. Dislocation, αʹ and ε-martensite are formed, and the grain size is refined by deformation and thermo-mechanical treatment. With an increasing number cycles in the thermo-mechanical treatment, the volume fraction of ε-martensite increases and then decreases, whereas dislocation and α'-martensite increases, and the grain size is refined. In thermo-mechanical treated specimens with five cycles, more than 10 % of the volume fraction of ε-martensite and less than 3 % of the volume fraction of αʹ-martensite are attained. Damping capacity decreases by thermomechanical treatment and with an increasing number of cycles of thermo-mechanical treatment, and this result shows an opposite tendency for general metal with deformation induced martensite transformation. The damping capacity of the thermomechanical treated damping alloy with deformation induced martensite transformation greatly affect the formation of dislocation, grain refining and α'-martensite and then ε-martensite formation by thermo-mechanical treatment.

본 연구는 실행연구의 방법을 대학의 학습부진 학생들의 학습지원 프로그램 개발을 위하여 수행되었다. 실행연구의 절차에 따라 문헌 및 사례조사를 통하여 프로그램 개발의 시사점을 도출하고, 예비 프로그램 적용을 위하여 전체 학생을 대상으로 개설되어 있는 교과목에 ‘학습상담’ 및 학습포트폴리오 적용의 방식을 도입함으로써 그 효과를 확인하였다. 이후 학습부진 학생을 위한 지원 프로그램을 개발하여 실시하고 학생들의 만족도를 확인하였다. 이에 따라 학습자의 개별적 특성에 부합하는 학습지원 프로그램을 개발하였다.

U-flanged truss beam is composed of u-shaped upper steel flange, lower steel plate of 8mm or more thickness, and connecting lattice bars welded on the upper and lower sides. The hybrid beam with U-flanged steel truss is made in the construction site through pouring the concrete, and designated as U-flanged truss hybrid beam. In this study the structural experiments on the 4 hybrid beams with the proposed basic shapes were performed, and the flexural capacities from the tests were compared with those from the theoretical approach. The failure modes of each specimen were quite similar. The peak load was reached with the ductile behavior after yielding, and the failure occurred through the concrete crushing. The considerable increasement of deformation was observed up to the concrete crushing. The composite action of concrete and steel member was considered to be reliable from the behavior of specimens. The flexural strength of hybrid beam has been evaluated exactly using the calculation method applied in the boubly reinforced concrete beam. The placement of additional rebars in the bottom instead of upper side is proposed for the efficient design of U-flanged truss hybrid beam.

U-flanged truss beam is composed of u-shaped upper steel flange, lower steel plate of 8mm or more thickness, and connecting lattice bars. Upper flange and lower plate are connected by the diagonal lattice bars welded on the upper and lower sides. In this study the structural experiments on the U-flanged truss beams with various shapes of upper flange were performed, and the flexural and shear capacities of U-flanged truss beam in the construction stage were evaluated. The principal test parameters were the shape of upper flange and the alignment space of diagonal lattice bars. In all the test specimens, the peak loads were determined by the buckling of lattice bar regardless of the upper flange shape. The test results have shown that the buckling of lattice bar is very important design factor and there is no need to reinforce the basic u-shaped upper flange. However, the early lattice buckling occurred in the truss beam with upper steel bars because of the insufficient strength and stiffness of upper chord, and the reinforcement in the upper chord is necessary. The formulae of Eurocode 3 (2005) have presented more exact evaluations of lattice buckling load than those of KBC 2016.

Light Mineral Oil is a material generally used as an overlay covering microdrops of culture medium in petri dishes. Although Light Mineral Oil can protect the damage by oxidation in air, it can't completely protect the damage by evaporation and alteration of pH and osmolality in culture medium. To minimize the damage by evaporation and alteration of pH and osmolality, we assumed that Heavy Mineral Oil could be used as an alternative. Heavy Mineral Oil is high purity paraffin oil which has more viscosity and density than Light Mineral Oil, so it can prevent evaporation and maintain stable osmolality and pH in culture medium more than Light Mineral Oil. The objective of this study was to examine whether the effect of Heavy Mineral Oil is superior to the effect of Light Mineral Oil during in vitro cultivation of porcine oocytes. According to the data of repeated six experiments, survival and cleavage rate of porcine oocytes, and cell number of blastocysts were not significantly different between two groups. However, the in vitro development rate of porcine parthenogenetic embryo was significantly higher in Heavy Mineral Oil group than in Light Mineral Oil group (Light, 36.6% ± 3.9%; and Heavy, 52.1% ± 6.4%, p < 0.05). Thus, these results indicated that the treatment of Heavy Mineral Oil can improve the in vitro developmental capacity of porcine parthenogenetic embryos compared to Light Mineral Oil.

The national natural monument of Korea, Jeju Black Cattle (JBC), it is a native species with unique blood line. This cattle breed needs mass production and industrialization to further improve and preserve their characteristics. This study was to examine whether there were differences in in vitro developmental rates according to body weight (<300, 300 ~ 350, 350 ~ 400 and >400 kg) and grade (1++, 1+, 1, 2 and 3), and oocyte donors or non-donors. As a method of IVM, groups of ten cumulus oocyte complexes (COCs) were cultured in 50 μl droplets of maturation medium (TCM199 supplemented with 10% FBS, 0.2 mM sodium pyruvate, 1 μg/ml follicle-stimulating hormone, 1 μg/ml estradiol-17β) under mineral oil at 38.8℃ in an incubator with a 5% CO2 atmosphere for 22 to 24 h. For IVF, 44 ul IVF drop contained 10 oocytes with sperm concentration of 1 × 106 cells/ml, and then 2 μl heparin and 2 μl PHE (20 μM peicillamine, 10 μM hypotaurine, 2 μM epinephrine) were added. For IVC, after 44±2 h of incubation, cleaved embryos were incubated in CR1aa medium containing 3 mg/ml FAF-BSA until day 4 at 38.8℃ in a 5% CO2 incubator. Embryos were then cultured in CR1aa medium containing 10% FBS until day 8. As a result, in vitro development rates were the highest in 350 ~ 400 kg body weight group and in 1++ grade group than other groups (p<0.05). However, there was no difference in in vitro developmental capacity of classified donor and non-donor oocyte groups. This result demonstrated that the better in vitro developmental capacity was obtained in high level originated oocyte groups (350 ~ 400kg, 1++ grade) than in others, while there was no different in donor types.