• Proceedings of the IEEK Conference
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• 2001.10a
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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.

• Bulletin of Food Technology
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• v.25 no.3
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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.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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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.

• Journal of the Korean Chemical Society
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• v.36 no.5
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• pp.685-691
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• 1992

The $d^8$-transition metal complexes containing diphosphine, $MCl_2PP$ were prepared by using $K_nMCl_m$ as starting materials, wherein M were Ni(II), Pd(II), Pt(II) and Au(III) and PP were bis(diphenylphosphino)methane(dppm), bis(diphenylphosphino)ethane(dppe), bis(diphenylphosphino)propane (dppp) and bis(diphenylphosphino)ethylene(dppety). The complexes were characterized by the spectral property $(^H-NMR$, $^{31}P-NMR$ and UV-Visible spectra) together with elemental analysis. The complexes were tested for the catalytic activity on the formation reactions of 3(2H)-furanone and cyclic carbonate. The only Ni(II)- and Pd(II)-diphosphine complexes displayed a good catalytic effects in the production of 3(2H)-furanone from 2-methyl-3-butyn-2-ol [reaction (1)]. But all the diphosphine complexes as catalyst were almost inactive towards cyclic carbonate production preaction [reaction (2)].

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.1
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• pp.37-40
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• 1983

To determine harvesting time of ginseng, the changes of saponin contents and PT/PD ratios of triol saponin vs. diol saponin in relation to root age of Panax ginseng. Total saponin contents were increased in relation to root age, 5-years was higher than 6-years for saponin contents. Therefore, it considered that can be obtained the desired results to harvest at 5-years. Also, PT/PD ratios were increased in relation to root age, 6-years was highest. Considering PT/PD ratios in relation with pharmaceutical action, it must be harvested at 6-years.

• Clean Technology
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• v.16 no.1
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• pp.19-25
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• 2010

In this work, the conversion of crystalline cellulose into polyols in the presence of hydrogen was examined over noble metal (Pt, Ru, Ir, Rh, and Pd) catalysts supported on activated carbon. For comparison, Pt/${\gamma}-Al_2O_3$ and Pt/H-mordenite were also investigated. Several techniques: $N_2$ physisorption, X-ray diffraction(XRD), inductively-coupled plasma-atomic emission spectroscopy (ICP-AES), temperature-programmed reduction with $H_2$ ($H_2$-TPR) and CO chemisorption were employed to characterize the catalysts. The cellulose conversion was not strongly dependent on the types of the catalyst used. Pt/AC showed the highest yields to polyols among activated carbon-supported noble metal catalysts, viz. Pt/AC, Ru/AC, Ir/AC, Rh/AC and Pd/AC.

• Journal of Sensor Science and Technology
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• v.21 no.6
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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.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.1
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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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• v.10 no.3
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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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• v.30 no.8
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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.