• 한국자원공학회지
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• 제55권6호
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• pp.588-595
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• 2018

이 연구에서는 국내에 분포하는 광산폐기물(광물찌꺼기, 폐(광)석) 적치장의 침출수 유출 현황을 조사하고 중금속 오염도를 평가하였다. 현장답사 시 채취한 23개소의 적치장 침출수 미량원소 분석결과 원소별 최대함량(mg/L)은 Al 53.98, As 16.19, Cd 1.15 Cu 37.30, Fe 28.64, Mn 39.00, Ni 0.097, Pb 0.750으로 검출되었다. 모니터링 대상 적치장 6개소의 침출수를 3개월간 분석한 결과, 주요 개발광종에 따라 2개소의 금-은광산에서는 As, Cd, Cu, Fe, Mn, Zn 및 Al, 2개소의 연-아연광산에서는 Cd, Mn, Zn 및 Al, 2개소의 기타광종(중석, 철) 개발광산에서는 As, Fe, Mn이 지속적으로 수질환경기준을 초과하는 높은 함량이 유출되고 있음을 확인하였다. 그러므로 이들 6개 광산폐기물 적치장에서 배출되는 침출수에 대한 지속적인 모니터링이 필요하다.

• 동양고전연구
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• 제72호
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• pp.365-400
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• 2018

10천간 12지지를 합성한 60개의 서수부호(序數符號)로 각각의 연월일시를 표현하였던 간지(干支) 책력(冊曆)에서의 그 기호는, 동양의 전통 의학(醫學) 분야에서 발병과 치료에 영향을 미치는 요인의 표식으로 쓰였을 뿐만 아니라, 여러 술수(術數) 분야에서의 길흉화복(吉凶禍福) 예단 지표로도 사용되었다. 이 간지력(干支曆) 부호를 기준으로 삼은 많은 술수 이론들이 한대(漢代) 이전까지 상당부분 갖추어졌던 것에 반해, '그것이 그렇게 된' 근원적 원리에 대한 이후의 책력학적 논의는 찾아보기 어렵다. 세성(歲星)(목성)이 황도대의 12개 '자리[차(次)]' 중에서 어느 곳에 있는 것인지로 그 한 해의 연명(年名)이 정해지는 천체력 기년 방식에는, 크게 세성기년법(歲星紀年法) 태세기년법(太歲紀年法) 간지기년법(干支紀年法) 등이 있다. 태세기년법과 명칭만 다를 뿐 실제로는 동일한 기년법이라 할 수 있는 간지기년법에서는 다시 세 가지 이상의 방식이 존재하며, 그 중 하나가 한대(漢代) 이래로 현재까지 중국과 우리나라 등지에서 끊김 없이 사용되고 있는 것이다. 2018년 올해의 간지 연명이 무술(戊戌)이 된 것은 순전히 '우연'에 의한 것이었다. 따라서 본 논의에서 필자는, 연월일시의 간지 부호를 가지고 고유 이론들을 구성하는 각종 전통 술수 분야에서 이에 대한 자각의 필요성을 역설(力說)하였다. 만 12년에 조금 못 미치는 목성의 1주천(周天) 주기 때문에, 천여 년에 한 번씩 약 85년 동안만 '황도대에서의 세성(歲星) 위차(位次)'와 '12지지(地支) 부호(符號)의 연명(年名)'이 서로 부합되는 상황이 펼쳐지는데, 최근의 수십 년이 그 시기가 됨을 확인하였다. 아울러서 28수(宿)를 바라보는 적절한 방법에 대해서도 함께 논하였다. 간지 책력이 각종 술수는 물론 전통 의술의 이론적 기반과도 결부된 것이니 만큼, 고대(古代) 천체력(天體曆)의 근원적 이론에 대한 심도 있는 연구는, 동양 전통 학문과 문화의 계승 발전 차원에서도 결코 소홀히 넘길 수 없는 일이다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.356-359
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• 2004

Above all Ni-alloys Inconel 625 is used widely in plate of welding structural materials such as turbine case, a combustor of liner. In general, weldability of Inconel 625 is not well because of poorly liquids of weld metal also it have a broken probability oj the welding crack. In case of FCAW weld process, it is not easy to develope of welding materials, because it is possible only fillet welding at view position of look down except for butt welding. But recently, though it is more used by FCAW process, owing to welding materials worked at the vertical position. the study for FCAW weld of Inconel 625 is actively not yet worked. In this study, the weldability and weld characteristics(mechanical characteristics, corrosive property) of Inconel 625 are considered in FC4W weld associated with the several shielding gases$80\%Ar\;+\;20\%\;CO_2,\;50\%Ar\;+\;50\%\;CO_2,\;100\%\;CO_2$ in viewpoint of welding productivity. The results of impact test are follows; It was evaluated 70J at shielding gase of $100\%\;CO_2$, and obtained about 35J at the other shielding gases. If it was used for parts be required the impact value at the extremely low temperature, it is expected to have the advantage of using the $100\%\;CO_2$ shield gase than the others.

• 폴리머
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• 제32권4호
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• pp.295-304
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• 2008

This study examined the oxidative polycondensation reaction of 2-[(pyridin-4-yl-) methyleneamino] pyridine-3-ol (2-PMAP) using air $O_2$ and NaOCl oxidants at various temperatures and times in aqueous alkaline and acidic media. Under these reactions, the optimum reaction conditions using air $O_2$ and NaOCl oxidants were determined for 2-PMAP. The number-average molecular weight ($M_n$), weight average molecular weight ($M_w$), and polydispersity index (PDI) values of O-2-PMAP synthesized in aqueous alkaline media were found to be 960, 1230, and $1.281\;g\;mol^{-1}$ using NaOCl, and 1030, 1520, and $1.476\;g\;mol^{-1}$ using air $O_2$, respectively. At the optimum reaction conditions, the yield of O-2-PMAP in aqueous alkaline media was 92.50% and 85.70% for air $O_2$ and NaOCl oxidants, respectively. The yield of O-2-PMAP in aqueous acidic media was 88.5% and 88.0% for NaOCl and air $O_2$ oxidants, respectively. O-2-PMAP was characterized by $^1H-$, $^{13}C$-NMR, FT-IR, UV-vis, SEC, and elemental analysis. TGA-DTA analysis revealed O-2-PMAP and its oligomer metal complex compounds, such as $Co^{+2}$, $Ni^{+2}$, and $Cu^{+2}$, to be stable against thermal decomposition and their weight losses at $1000^{\circ}C$ were found to be 73.0, 58.0, 53.5%, and 50.0%, respectively. In addition, the antimicrobial activities of the monomer and oligomer were tested against E. Coli (ATCC 25922), E. Faecelis (ATCC 29212), P. Auroginasa (ATCC 27853), and S. Aureus (ATCC 25923).

• 열처리공학회지
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• 제11권2호
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• pp.140-149
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• 1998

The graphitization is affected by the addition of small amount of the elements, such as Si, Al, Ni, B, Cr and Mn etc. Boron is well known as the most effective element for the graphitization of cementite in high carbon steels. But a study on quantitative analysis of B effect on the graphitization is few reported. Therefore the effect of boron addition in Fe-0.65%C-1.0%Si-0.5%Mn steels on the graphitization is investigated quantitatively using hardness tester, optical microscope and scanning electron microscope, neutron induced microscopic radiography. The graphitization in high carbon steels is promoted with 0.003~0.005%B addition. But the graphitization in steels which has no boron takes long holding time at $680{\sim}720^{\circ}C$. The hardness of quenched steel containing 0.003%B is higher than that of 0.005%B added steel due to complete dissolution of fine graphites into the austenite. The 0.003%B added high carbon steel graphitized at $680^{\circ}C$ for 25hr is useful steel for the agricultural implements and automobile parts which needed a good formability and high hardness.

• Smart Structures and Systems
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• 제9권3호
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• pp.231-251
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• 2012

The stochastic optimal control for a piezoelectric spherically symmetric shell subjected to stochastic boundary perturbations is constructed, analyzed and evaluated. The stochastic optimal control problem on the boundary stress output reduction of the piezoelectric shell subjected to stochastic boundary displacement perturbations is presented. The electric potential integral as a function of displacement is obtained to convert the differential equations for the piezoelectric shell with electrical and mechanical coupling into the equation only for displacement. The displacement transformation is constructed to convert the stochastic boundary conditions into homogeneous ones, and the transformed displacement is expanded in space to convert further the partial differential equation for displacement into ordinary differential equations by using the Galerkin method. Then the stochastic optimal control problem of the piezoelectric shell in partial differential equations is transformed into that of the multi-degree-of-freedom system. The optimal control law for electric potential is determined according to the stochastic dynamical programming principle. The frequency-response function matrix, power spectral density matrix and correlation function matrix of the controlled system response are derived based on the theory of random vibration. The expressions of mean-square stress, displacement and electric potential of the controlled piezoelectric shell are finally obtained to evaluate the control effectiveness. Numerical results are given to illustrate the high relative reduction in the root-mean-square boundary stress of the piezoelectric shell subjected to stochastic boundary displacement perturbations by the optimal electric potential control.

• Asian-Australasian Journal of Animal Sciences
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• 제25권9호
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• pp.1229-1236
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• 2012

Our previous studies showed that kisspeptin-10 (Kp-10) injected in vivo can markedly increase lipid anabolism in liver of quails. In order to investigate the direct effect of Kp-10 on lipid metabolism of hepatocytes in birds, cells were separated from embryos livers and cultured in vitro with 0, 100 and 1,000 nM Kp-10, respectively. The results showed that after 24 h treatment, cells viability was not affected by 100 nM Kp-10, but showed a mild decrease with 1,000 nM Kp-10 compared to the control cells. Based on the results of the cell viability, 100 nM dosage of Kp-10 was selected for the further study and analysis. Compared with control cells, total cholesterol (Tch) contents in 100 nM treated cells were increased by 51.23%, but did not reach statistical significance, while the level of triglyceride (TG), high density of lipoprotein-cholesterol (HDL-C) and low density of lipoprotein-cholesterol (LDL-C) were significantly increased. Real-time PCR results showed that ApoVLDL-II mRNA expression had a tendency to increase, genes including sterol regulatory element-binding protein-1 (SREBP-1), acetyl coenzyme A carboxylase ${\alpha}$ ($ACC{\alpha}$), carnitine palmitoyltransferase 1 (CPT1), 3-hydroxyl-3-methylglutaryl-coenzyme A reductases (HMGCR) and stearyl coenzyme A dehydrogenase-1 (SCD1) mRNA in hepatocytes were significantly down-regulated by 100 nM Kp-10. However, contrary to its gene expression, SREBP-1 protein expression was significantly up-regulated by 100 nM Kp-10. Some of the significant correlations in mRNA expression were found between genes encoding hepatic factors or enzymes involved in lipid metabolism in liver of birds. These results indicate that Kp-10 stimulates lipid synthesis directly in primary cultured hepatocytes of chickens.

• Smart Structures and Systems
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• 제15권2호
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• pp.447-468
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• 2015

Modal identification of civil engineering structures based on ambient vibration measurement has been widely investigated in the past decades, and a variety of output-only operational modal identification methods have been proposed. However, vibration modes, even fundamental low-order modes, are not always identifiable for large-scale structures under ambient vibration excitation. The identifiability of vibration modes, deficiency in modal identification, and criteria to evaluate robustness of the identified modes when applying output-only modal identification techniques to ambient vibration responses were scarcely studied. In this study, the mode identifiability of the cable-stayed Ting Kau Bridge using ambient vibration measurements and the influence of the excitation intensity on the deficiency and robustness in modal identification are investigated with long-term monitoring data of acceleration responses acquired from the bridge under different excitation conditions. It is observed that a few low-order modes, including the second global mode, are not identifiable by common output-only modal identification algorithms under normal ambient excitations due to traffic and monsoon. The deficient modes can be activated and identified only when the excitation intensity attains a certain level (e.g., during strong typhoons). The reason why a few low-order modes fail to be reliably identified under weak ambient vibration excitations and the relation between the mode identifiability and the excitation intensity are addressed through comparing the frequency-domain responses under normal ambient vibration excitations and under typhoon excitations and analyzing the wind speeds corresponding to different response data samples used in modal identification. The threshold value of wind speed (generalized excitation intensity) that makes the deficient modes identifiable is determined.

• Transactions on Electrical and Electronic Materials
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• 제16권6호
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• pp.342-345
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• 2015

The n -type Hf_0.25Zr_0.25Ti_0.5NiSn_0.998Sb_0.002 Half-Heusler (HH) alloy composition was prepared by using the induction melting method in addition to the mechanical grinding, annealing, and spark plasma sintering processes. Analysis of X-ray diffraction (XRD) results indicated the formation of a pure phase HH structured compound. The electrical and thermal properties at temperatures ranging from room temperature to 718 K were investigated. The electrical conductivity increased with increasing temperatures and demonstrated nondegenerate semiconducting behavior, and a large reduction in the thermal conductivity to the value of 2.5 W/mK at room temperature was observed. With the power factor and thermal conductivity, the dimensionless figure of merit was increased with temperature and measured at 0.94 at 718 K for the compound synthesized by the induction melting process.

• 한국자원식물학회지
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• 제16권1호
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• pp.25-33
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• 2003

일반적으로 토양의 경우 천매암 및 셰일 지역이 높은 원소 함량을 보였고 원소의 상관관계에서 셰일 지역이 많은 원소에서 높은 상관관계를 보였다. 지역에 따른 인삼의 2년근과 3년근의 비교에서 2년근에서 높았는데, 특히 화강암과 편마암지역이 셰일지역에 비해 2년근에서 두드러지게 높았다. 같은 연령 인삼들의 지역적 비교에서 화강암지역이 낮았으며, 셰일 및 천매암의 비교에서는 셰일이 높았다. 인삼의 부위 별 비교에서 2년근과 3년근에 관계 없이 상부가 높은 원소함량을 보였다 토양과 인삼 평균치와의 비교에서 대부분 원소가 인삼 조성에 비해 토양에서 높은 함량을 보였고, 토양과 인삼조성 관계에서 유사한 증감 경향을 보였다. 전체적으로 일반적인 전이원소의 부정적인 영향을 전제로 하면 세 토양중 화강암 지역이 인삼의 최적지이며 셰일 지역이 제일 불리한 지역임을 암시한다.