• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.482-488
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• 2001

Platinum group metals (pgm) are useful to many industries such as chemical, dental and medical, petroleum, refining, electrical and electronic, and automotive. Researchers at the South Dakota School of Mines and Technology and PGM Recovery Ltd. have developed jointly an environmentally sound and metallurgically efficient process for extracting these metals from secondary sources. Once these metals have been dissolved in the leach liquor, the individual metals mainly platinum, palladium, and rhodium, should be separated in order to recover the individual metals with high purity. During this investigation, solvent extraction has been chosen as the method used to achieve the separation and extraction of platinum, palladium, and rhodium from the leach liquor. There were three solutions used throughout this procedure: 1) Synthetic solution (200 ppm Pt 80 ppm Pd 20 ppm Rh; 300 ppm Pt, 180 ppm Pd 50 ppm Rh), and 2) Auto catalyst leach liquors (100 ppm Pt, 30 ppm Pd, 20 ppm Rh). The solvents investigated included Lix 84(2-hydroxy-5-nonylacetonphenone oxime in a mixture with 5-dodecylsalicyloxime), Lix 84-I, ACORGA CLX-50 (diester of pyridine 3,5 dicarboxylic acid), and di-hexyl sulfide. The extraction values achieved using ACORGA CLX-50, Lix 84, and Lix 84-I were respectively Pt (25%, 0% 0%), Pd (100%, 99.8%, 95.3%), and Rh (99.1%, 35.5%, 4.25%). The stripping processes for the Lix 84, and Lix 84-I were proven to be more involved than others. The solutions were required to be simultaneously heated and stirred. The percentages acquired through these processes yielded unsatisfactory results. The stripping procedure for the ACORGA CLX-50 was easier to execute, yet the percentage recovered from this process was also unsatisfactory. Overall the di-hexyl sulfide has proved to be the most successful organic for this procedure. The average percent extracted for palladium was excellent with 99.9% - 100% with very little Platinum and rhodium extracted. The ability of stripping palladium in ammonia solution was also found to be excellent.

• 식품기술
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• 제25권3호
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• pp.258-266
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• 2012

경기인삼 품질 특성을 확립하기 위한 기초자료로 진세노사이드 특성을 조사하였다. 경기도내 4대 인삼조합(개성, 김포 파주, 경기동부, 안성) 인삼을 인삼농가에서 직접 채취하거나 채굴현장에서 수집하여 진세노사이드 함량 및 조성을 분석하여 그 특성을 분석해 본 결과는 다음과 같다. 1. 경기인삼 4, 5, 6년근의 총 진세노사이드 함량은 3.92 mg/g, 4.34 mg/g 및 4.94 mg/g으로 각각 나타나 재배 년수가 증가할수록 함량이 높아짐을 알 수 있었다. PD/PT 비율은 1.12, 1.34 및 1.40으로 년근 수가 증가할수록 PD계열 진세노사이드 함량이 증가하였다. 2. 경기인삼 6년근의 크기별 진세노사이드 함량을 측정한 결과 큰 인삼(大)의 총 진세노사이드 함량은 5.19 mg/g, 작은 인삼은 4.69 mg/g으로 같은 년근 수에서는 인삼의 크기에 따라 진세노사이드함량 차이는 크게 나타나지 않았다. 3. 6년근 부위별 총 진세노사이드 함량은 주근이 3.70 mg/g이며 세근은 6.37 mg/g으로써 주근보다 세근에서 1.72배 함량이 높은 것으로 나타났다. 진세노사이드 각각 함량별로 비교해 볼 때 PD계인 진세노사이드 $Rb_2$, $Rb_3$, Rc, Rd와 PT계인 Re, $Rg_2$가 주근보다 세근에서 높은 함량을 나타내어, PD/PT 비율이 1.08과 2.06으로 세근은 주근보다 PD계열 함량이 2배 이상 높은 것으로 나타났다.

• 한국자기학회지
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• 제5권5호
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• pp.716-719
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• 1995

Pd/(Pt/Co/Pt) modulated multilayer films have been deposited on various substrates with Pd/Pt buffer layers. Films grown at different temperatures have very distinct magnetic properties and surface microstructures. Atomic force(AFM) and scanning tunneling (STM) microscopies studies of these films reveal that films deposited at room temperature have small grain structures with an average grain size of about $140\;{\AA}$. However, much larger grains of about $1200\;{\AA}$ in size are observed in the films grown on buffer layers which were deposited at $500^{\circ}C$. These large grains are found to actually consist of smaller grains of about $170{\AA}$ in diameter. SQUID magnetic and Kerr hysteresis loop measurements indicate that multilayer films with large grains exhibit high magnetic coercivities of around 5 kOe. A subgrain growth model is proposed to understand the observed grain structures in the multilayers.

• 대한화학회지
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• 제36권5호
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• pp.685-691
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• 1992

디포스핀을 포함한 몇가지 $d^8$ 전이금속착물$(MCl_2PP)$은 출발물질 $K_nMCl_m$을 사용하여 합성하였다. 중심금속(M)은 Ni(II), Pd(II), Pt(II), Au(III)이며, 디포스핀(PP)은 bis(diphenylphosphino)methane(dppm), bis(diphenylphosphino)ethane(dppe), bis(diphenylphosphino)propane (dppp) 및 bis(diphenylphosphino)ethylene(dppety)이었다. 착물의 조성이나 특성은 원소분석과 $^1H-NMR$, $^{31}P-NMR$ 및 UV-Visible 스펙트럼을 이용하여 확인하였다. 이들 착물의 촉매적 활성은 3(2H)-furanone 및 cyclic carbonate 생성반응에 대하여 각각 조사하였다. 2-methyl-3-butyn-2-ol로부터 생성물 3(2H)-furanone을 얻은 반응 (1)에서 Ni(II)-, Pd(II)-diphosphine 착물은 좋은 촉매적 효과를 나타내었다. 그러나 이들 diphosphine 착물들은 cyclic carbonate 생성반응 (2)에 대해 촉매제로서의 활성을 거의 나타내지 않았다.

• 한국식품영양과학회지
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• 제12권1호
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• pp.37-40
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• 1983

인삼(人蔘)의 주요약리성분(主要藥理成分)으로 밝혀지고 있는 사포닌의 함량변화(含量變化)를 중심으로 하여 인삼(人蔘)의 채굴연수(採掘年數)의 진단(診斷)과 약리작용(藥理作用)에 대한 기초자료(基礎資料)를 얻기 위하여 재배인삼(栽培人蔘)의 생육연수(生育年數)에 따른 총(總)사포닌 함량(含量)의 변화(變化), diol사포닌과 triol사포닌의 비교(比較) 및 PT/PD 비(比)등을 조사(調査)하여 다음과 같은 결과(結果)를 얻었다. (1) 생육연수(生育年數)에 따른 총(總)사포닌함량(含量)은 연근(年根)이 증가할 수록 총(總)사포닌함량(含量)이 증가 하였는데 5 년근(年根)에서 5.19%로 가장 높았으며 6년근(年根)에서는 4.80%로 오히려 감소하는 경향이었다. (2) 총(總)사포닌함량(含量)만을 고려(考慮)한다면 6년근(年根)보다 5 년근(年根)에서 채굴(採掘)함이 바람직하다. (3) 생육연수(生育年數)에 따른 PT/PD비(比)를 보면 연근(年根)이 증가할 수록 차차 증가하여 6년근(年根)이 0.51로서 가장높았으며 5년근(年根)의 0.48보다 6.25%나 더 높았다. (4) 따라서 PT/PD비(比)의 증가량을 고려한다면 6년근(年根)에서 채굴(採掘)함이 바람직 하였다.

• 청정기술
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• 제16권1호
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• pp.19-25
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• 2010

결정성의 셀룰로우스를 수소분위기하에서 다양한 귀금속 촉매를 이용하여 폴리올로 전환시키는 연구를 수행하였다. 촉매는 단일 귀금속(Pt, Ru, Ir, Rh, Pd)을 활성탄에 습식함침법으로 담지시켜서 제조하였으며, Pt/$\gamma-Al_2O_3$와 Pt/H-mordenite를 비교촉매로 사용하였다. 생성물은 고압액체크로마토그래피로 분석하였다. 촉매는 질소흡착, X-선 회절법, 유도결합플라즈마분광법(ICP-AES), 수소-승원환원분석($H_2$-TPR), 그리고 일산화탄소 화학흡착을 통하여 분석하였다. 셀룰로우스의 전환율은 사용한 촉매와 연관관계가 낮은 것으로 나타났으며 활성탄에 담지된 귀금속 촉매중에서 Pt/AC가 높은 폴리올의 수득률에 바람직한 것으로 조사되었다.

• 센서학회지
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• 제21권6호
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• pp.425-428
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• 2012

This paper presents the fabrication and characterization of graphene based hydrogen sensors. Graphene was synthesized by annealing process of Ni/3C-SiC thin films. Graphene was transferred onto oxidized Si substrates for fabrication of chemiresistive type hydrogen sensors. Au electrode on the graphene shows ohmic contact and the resistance is changed with hydrogen concentration. Nanoparticle catalysts of Pd and Pt were decorated. Response factor and response (recovery) time of hydrogen sensors based on the graphene are improved with catalysts. The response factors of pure graphene, Pt and Pd doped graphenes are 0.28, 0.6 and 1.26, respectively, at 50 ppm hydrogen concentration.

• 한국대기환경학회지
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• 제14권1호
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• pp.63-72
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• 1998

Simultaneous CO and $C_3H_6$ oxidation was carried out over noble metal supported monolith catalysts in a flow thorugh type reactor at the temperature ranging from room temperature to $500^\circ$C. Pt and Pd were selected as major active species, 10wt% of Ce was impregnated as an additive and alumina and silica were used as supports. The reactant gases were simulated and the reaction products were analyzed by on-line G.C.. EDX, SEM, TGA, XRD and optical microscope were used to analyze the characteristics of the prepared catalysts. Under the given conditions in this study, the catalysts supported on alumina showed better activity for CO oxidation, while Pd catalysts showed better activity for $C_3H_6$ oxidation. The improvement of conversion due to increase in thermal stability possibily by Ce addition was observed only for Pt catalysts.

• Archives of Pharmacal Research
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• 제10권3호
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• pp.188-192
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• 1987

The present study was undertaken to determine the inhibitory effects of orally administered ginseng saponins (GS), protopanaxadiol saponins (PD), protopanaxatriol saponins (PT) and ginseng ether fraction (GE) on the development of morphine induced tolerance and physical dependence in mice and also to determine the hepatic glutathione contents. GS, PD and PT inhibited significantly the development of morphine induced tolerance and physical dependence, but GE was effective only on the inhibition of the development of morphine induced physical dependence. GS, PD, PT and GE also inhibited the hepatic glutathione level decrease induced by morphine multiple injections.

• Journal of Advanced Marine Engineering and Technology
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• 제30권8호
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• pp.870-876
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• 2006

In proportion to the increase of industrial development, emission troubles were concerned as global issue. For these reasons, so many researchers and associated institutes effort to reduce pollution with new technology and various devices. As a kind of these methods, we used catalysts as a after-treatment system. At first, we made equipment of model furnace. And various catalysts were equipped at exhaust duct of combustion system, and excess air ratio(a), change cell numbers catalyst materials(Pt, Pd) were changed as experimental conditions. With these various condition, temperature. NOx, CO, HC, $CO_2$ and $O_2$ concentration were measured. As a result, NOx conversion increased with increasing of cell number in Pd catalyst. And Pt catalyst became 100% conversion at 200 and 300 cell. Also, Pt catalyst was better than Pd catalyst at a=1.5 in this condition. In addition, CO and HC concentrations were decreased at a = 1.5 with Pd catalyst.