• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.1-26
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• 1994

The purpose of this study was to investigate the dissolution components during corrosion of amalgams and to identify surface corrosion products in the modified Fusayama artificial saliva. Four type of amalgam alloys were used: low copper lathe cut amalgam alloy (Cavex 68), low copper spherical amalgam alloy (Caulk Spherical Alloy), high copper admixed amalgam alloy (Dispersalloy) and high copper single composition amalgam alloy (Tytin). Each amalgam alloy and Hg were triturated according to the manufacturer's direction by means of mechanical amalgamator (Capmaster, S.S.White), and then the triturated mass was inserted into the cylindrical metal mold which was 10mm in diameter and 2.0mm in height and condensed with compression of 150kg/$cm^2$ using oil pressor. The specimens were removed from the mold and stored at room temperature for 7 days and cleansed with distiled water for 30 minutes in an ultrasonic cleaner. The specimens were immersed in the modified Fusayama artificial saliva for the periods of 1 month, 3 months and 6 months. The amounts of Hg, Cu, Sn and Zn dissolved from each amalgam specimen immersed in the artificial saliva for the periods of 1 month, 3 months and 6 months were measured using Inductivity Coupled Plasma Atomic Emission Spectrometry (ICPQ-1000, Shimadzu, Japan) and amount of Ag dissolved from amalgam specimen was measured using Atomic Absorption Spectrophotometry (Atomic Absorption/Flame emission spectrophotometer M-670, Shimadzu, Japan). A surface corrosion products of specimens were analysed using Electron Spectroscopy Chemical Analyser (ESCA PHI-558, PERKIN ELMER, U.S.A.). The secondary image and back scattered image of corroded surface of specimens was observed under the SEM, and the corroded surface of specimens was analysed with the EDX. The following results were obtained. 1. The dissolution amount of Cu was the most in high copper admixed amalgam(Dispersalloy) and the least in high copper single composition amalgam(Tytin). 2. Sn and Zn were dissolved during all the experiment periods, and dissolution amounts were decreased as the time elapsed. 3. Initial surface corrosion products were ZnO and SnO. 4. Corrosion of ${\gamma}$ and ${\gamma}_2$ phase in low copper amalgams was observed and Ag-Cu eutectic alloy phase was corroded in low copper spherical amalgam(Caulk Sperical Alloy). 5. Corrosion of ${\gamma}$ and $\eta$' phase in high copper amalgams was observed and Ag-Cu eutectic alloy phase was corroded in high copper admixed amalgam(Dispersalloy). 6. Sn-Cl was produced in the subsurface of low copper amalgams and high copper admixed amalgam.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.5-5
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• 2009

Thin-film-transistors (TFTs) that can be prepared at low temperatures have attracted much attention because of the great potential for transparent and flexible electronics. One of the mainstreams in this field is the use of organic semiconductors such as pentacene. But device performance of the organic TFTs is still limited due to low field-effect mobility and rapid degradation after exposing to air. Alternative approach is the use of amorphous oxide semiconductors as a channel. Amorphous oxide semiconductors (AOSs) based TFTs showed the fast technological development, because AOS films can be fabricated at room temperature and exhibit the possibility in application like flexible display, electronic paper, and larges solar cells. Among the various AOSs, a-IGZO has lots of advantages because it has high channel mobility, uniform surface roughness and good transparency. [1] The high mobility is attributed to the overlap of spherical s-orbital of the heavy post-transition metal cations. This study demonstrated the effect of the variation in channel thickness from 30nm to 200nm on the TFT device performance. When the thickness was increased, turn-on voltage and subthreshold swing was decreased. The a-IGZO channels and source/drain metals were deposited with shadow mask. The a-IGZO channel layer was deposited on $SiO_2$/p-Si substrates by RF magnetron sputtering, where RF power is 150W. And working pressure is 3m Torr, at $O_2/Ar$ (2/28 sccm) atmosphere. The electrodes were formed with electron-beam evaporated Ti (30 nm) and Au (70 nm) bilayer. Finally, Al (150nm) as a gate metal was thermal-evaporated. TFT devices were heat-treated in a furnace at 250 $^{\circ}C$ and nitrogen atmosphere for 1hour. The electrical properties of the TFTs were measured using a probe-station. The TFT with channel thickness of 150nm exhibits a good subthreshold swing (SS) of 0.72 V/decade and on-off ratio of $1{\times}10^8$. The field effect mobility and threshold voltage were evaluated as 7.2 and 8 V, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.55-55
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• 2011

질소 등을 GST225 상변화재료에 첨가시켜 비저항을 증가시킴으로서 PCRAM의 동작 전류를 감소시킨 연구가 선행된 바 있다. 본 연구에서는 GST225와 달리 고속 동작 특성을 갖는 것으로 널리 알려진 Ge-doped SbTe (GeST) 상변화 재료에 Carbon을 첨가하여 박막 특성을 연구하여 동작 전류 감소의 가능성을 타진하였다. 실험을 위한 박막 제작을 위해 2 inch size의 GeST 및 C doped GeST (C-GeST) single target을 이용하여 RF magnetron co-sputtering 하였다. 박막은 carbon이 첨가되지 않은 GeST와 carbon 첨가량이 늘어나는 순서로 C-GeST 1, C-GeST 2, C-GeST 3로 구성된다. 이 때 제작한 박막의 composition analysis를 위해 XRF/RBS/AES가 사용되었고 제작된 박막의 기본적인 특성평가를 위해 resistivity(${\rho}$)와 crystallzation temp.(Cx), surface morphology(AFM), x-ray diffraction pattern(XRD)를 측정하였다. 실험결과 GeST, C-GeST 1, C-GeST 2, C-GeST 3 박막의 Cx는 각각 209, 225, 233, $245^{\circ}C$로 측정되어 carbon 첨가량이 증가됨에 따라 결정화 온도가 증가되는 것을 알 수 있었다. 또한 ${\rho}$도 마찬가지로 annealing 온도를 약 $320^{\circ}C$로 할 경우 ${\rho}$(as-dep)와 ${\rho}$(crystalline) 모두 0.03 / $2.61*10^{-6}$, 0.08 / $7.93*10^{-6}$, 0.09 / $11.99*10^{-6}$, 0.13 / $13.49*10^{-6}{\Omega}{\cdot}m$로 증가하였다. 증가된 ${\rho}$의 원인이 박막의 grain size의 감소라고 단언 할 수는 없으나 AFM 측정결과 grain이라고 추측되는 박막 feature들의 size가 점차 감소하는 것을 확인하였다.

• Resources Recycling
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• v.5 no.1
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• pp.14-20
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• 1996

For recycl~ng alumhx~rn dross, the cbaraclcrislics of dross and ils reutll~zalin~af~te r plocsssing should he considered. Nurn~llumd ross was classified according to iB sire in this shldy. Tbe dross larger Illan 3001~1w as directly re-meltcd to recover aluminum, and the s~nallerd ~ossw as leachcd and riln~tedl o scparalc 111s eri~lerls alt and to oxidize the rnelals contained in the dross. As a rcwlt, amount of the dross uscd lo be dircarded ahcr processing could hc reduced Also, lhc chem~cal culnposit~ons of a domzstic alumlnum dross and the changes in con~posilii~ndsu ring processings were investigated. and Cound that most mctaU'ic aluminum in the dross was changed inlu alu~n~numox ide lhruugli the roasting. Tile processed dross would he ulillzed for malerials such as alumina, alumma cemenl or tilcs.

• The Korean Society of Law and Medicine
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• v.15 no.2
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• pp.367-397
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• 2014

Dans le contentieux m$\acute{e}$dical, il est difficile de prouver l'existence d'un lien de causalit$\acute{e}$ entre la faute m$\acute{e}$dicale et les pr$\acute{e}$judices subis par la victime. R$\acute{e}$partir bien de façon raisonnable la charge de la preuve du lien causal est alors une des questions pr$\acute{e}$occup$\acute{e}$es par la doctrine cor$\acute{e}$enne. La Cour supr$\hat{e}$me cor$\acute{e}$enne semble toutefois facilliter l'indemnisation des victimes dans les cas o$\grave{u}$ la responsabilit$\acute{e}$ du m$\acute{e}$decin a ${\acute{e}}t{\acute{e}}$ mise en cause, et cela en admettant des fois une solution op$\acute{e}$rant un renversement de la charge de la preuve du lien causal. Une telle attitude a ${\acute{e}}t{\acute{e}}$ m$\hat{e}$me affirm$\acute{e}$e dans un arr$\hat{e}$t rendu r$\acute{e}$cemment en cas de dommage caus$\acute{e}$ par le fait du produit de sant$\acute{e}$, notamment pour le cas de contamination virale par voie de transfusion. La Cour a $\acute{e}$galement reconnu que l'action se pr$\acute{e}$scrit $\grave{a}$ partir du moment de la consolidation du pr$\acute{e}$judice. Aux termes de cette $\acute{e}$tude, on pourra constater que le juge français reconna$\hat{i}$t aussi l'assouplissement de la charge de la preuve du lien de causalit$\acute{e}$ en mati$\acute{e}$re d'action m$\acute{e}$dicale. Il faudra toutefois souligner que le ph$\acute{e}$nom$\acute{e}$ne ne soit pas g$\acute{e}$n$\acute{e}$ralis$\acute{e}$ en droit français, d'autant plus que la pr$\acute{e}$somption de l'existence de la causalit$\acute{e}$ en la mati$\grave{e}$re a $\acute{e}$t$\acute{e}$ admise de mani$\grave{e}$re restrictive par la l$\acute{e}$gislation sp$\acute{e}$cifique. Tel $\acute{e}$tait notamment le cas pour les accidents de la contamination par le virus du sida ou de l'h$\acute{e}$patite C survenus apr$\grave{e}$s la transfusion. En d$\acute{e}$finitive, on peut dire qu'en droit français, le principe est maintenu en cas de manquement $\grave{a}$ une obligation de r$\acute{e}$sultat n$\acute{e}$e du contrat m$\acute{e}$dical, tandis que la Cour de cassation admet parfois en mati$\grave{e}$re de droit commun de la responsabilit$\acute{e}$ contractuelle la pr$\acute{e}$somption de causalit$\acute{e}$ en cas d'inex$\acute{e}$cution des obligations de r$\acute{e}$sultat. En fait, la pr$\acute{e}$somption de causalit$\acute{e}$ dans le contentieux m$\acute{e}$dical pourra mener les m$\acute{e}$decins $\grave{a}$ se diriger vers les traitements d$\acute{e}$fensifs. Cette situation peut m$\hat{e}$me conduire $\grave{a}$ emp$\hat{e}$cher le d$\acute{e}$veloppement de la science m$\acute{e}$dicale, enfin $\grave{a}$ une situation d$\acute{e}$savantageuse aux patients. Il y a alors lieu de se m$\acute{e}$fier des int$\acute{e}$r$\hat{e}$ts d$\acute{e}$s$\acute{e}$quilibr$\acute{e}$s entre le m$\acute{e}$decin et le patient. De ce point de vue, on peut estimer que le droit français donne des suggestions aux juristes cor$\acute{e}$ens dans la recherche des solutions plus ad$\acute{e}$quates en ce qui concerne la charge de la preuve du lien causal en mati$\acute{e}$re de responsabilit$\acute{e}$ m$\acute{e}$dicale.

• Journal of the Korean Magnetics Society
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• v.1 no.1
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• pp.12-16
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• 1991

The effect of annealing on the magnetic properties and the microstructures of the amorphous $Fe_{76-x}Cu_1Mo_xSi_{14}B_9$(x=2,3) alloys were investigated. When annealed at 500${^{\circ}C}$ for 1hr, $8{\sim}9{\times}10^3$ of the effective permeability and 3~4 A/m of the coercive force were achieved upon crystallization to $\alpha$-Fe phase. And the average diameter of the $\alpha$-Fe grains was about 20nm. For the nanovrystalline ferromagnets. the fine grain size is the important requirement to obtain a good soft magnetic property. In this work, in order to get the finer grain size of $\alpha$-Fe phase, two-step annealing treatment was given. That is, following the low-temperature at $400{^{\circ}C}$ for 1~3hr, the high-temperature annealing at $500{^{\circ}C}$ for 1hr was carried out. As the low-temperature annealing time increased, the effective permeability increased to $1.2{\sim}1.7{\times}10^4$ and the coercive force decreased to about 2 A/m. And the grain size was observed to be smaller than 10nm. The increased permeability and the decreased coercive force were attributed to the reduced average crystalline anisotropy by the refinement of $\alpha$-Fe(Si) grains.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.219-236
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• 1988

Bensulfuron concentrations of $10^{-7}$, $10^{-6}$, $10^{-5}$ and $10^{-4}M$ were applied to agar medium on susceptible (cv. KH 17854 and cv. IR 1846) and tolerant (cv. Chinsurah Boro II and IR 14252) rice cultivars were grown for microscopic inspection. Susceptible cultivars showed the decrease in shoot and root growth at the concentration of $10^{-5}M$ while ones showed no difference. Such a tendency was also observed from microscopic inspection in the elongation zone of shoot meristematic tissue. Seedlings grown in soil for 10 days were transfered to distilled water containing only bensulfuron solutions. There were significant differences between cultivars in terms of supression of shoot meristematic activity and swelling of cell volume. Observations of those cells made it clear that especially susceptible cultivars showed the irregular cell layering, vacuolation, cell swelling and partial damage in membrane of shoot tissue. The major response of root tips of susceptible cultivars showed the disorganization of cortex, rupture and contraction of membrane, inhibition of cell division, swelling and emergence of lateral root while tolerant ones showed no such responses.

• Journal of the Mineralogical Society of Korea
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• v.6 no.1
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• pp.1-16
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• 1993

The chemical and optical absorption spectroscopic characters of pink and colorless tourmalines from San Diego mine in California, U.S.A., blue/green tourmalines from anonymous mine, Brazil, and brownis black tourmalines from Uncheon and Haksan mines in Korea have been studied using X-ray diffractometer, electron microprobe, optical absorption spectroscopy, and heat treatment. Least-squares refinements give unit cell diminsions : a = 15.96-16.01 ${\AA}$, c = 7.15-7.16 ${\AA}$ for the brownish black tourmalines, a = 15.82 - 15.87 ${\AA}$, c = 7.09 - 7.10 ${\AA}$ for pink tourmalines, and a = 15.88 - 15.94 ${\AA}$, c = 7.12 - 7.15 ${\AA}$ for blue green tourmalines. The colors of tourmalines are responsible for the transition elements. The pink color is attributed to the $Mn^{3+}$ ions, the blue-green to $Fe^{2+}$ and $Mn^{2+}$, bluish green to $Cu^{2+}$, and the brownish black to $Fe^{2+}$, $Fe^{2+}$ - $Fe^{3+}$, and $Fe^{2+}$ - $Ti^{4+}$. The $Mn^{3+}$ ions of pink color tourmalines are stabilized in the Y sites compressed along the O(1)H-O(3)H axis by Jahn-Teller distortion. Heating removes the pink or red component from tourmalines, producing the colorless stones from the pink and red ones. The bluish green samples change into the greenish blue ones and a certain yellowish green samples change into the light green ones by heat treatment. In the elbaite-schorl series, the concentration of Fe and Mn are variable depending on the color zones. The green zone is characterrized by the high content of Fe and Mn are variable depending on the color zones. The green zone is characterized by the high content of Fe, whereas the pink zone by the high content of Mn. Mn increases in deep yellow zone compared with yellow or colorless zones.

• Biomolecules & Therapeutics
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• v.7 no.2
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• pp.178-184
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• 1999

Bamboo salt has been used for the purpose of precaution and treatment of certain diseases including cancer. Therefore, present study was carried out to ascertain the effects of bamboo salt upon anti-cancer, anti-hypertensive, and anti-diabetic activities as well. To examine the anti-cancer activity of bamboo salt, ICR mice implanted with 1$\times$l0$^{6}$ cells of sarcoma 180 intraperitoneally had been treated daily with bamboo salt A, crude salt, and reagent-grade NaCl (0.2, 1.0, and 2.0 g/kg, p.o.) for 60 days using adriamycin (2 mg/kg) as a positive control. Neither survival rate nor body weight had been significantly influenced by all the treatments indicating that bamboo salt A did not exert the anti-cancer effect on ICR mice. Anti-hypertensive activity was examined in spontaneously hypertensive rats (SHR) which had been administered with bamboo salt A, crude salt, and reagent-grade NaCl (0.1, 0.5, and 1.0% in drinking water) for 28 days using hydralazin (2 mg/kg) as a positive control. Blood pressure and heart rate were measured at 1, 3, and 4 weeks after the starting date. Significant anti-hypertensive activity was not observed in any treated group compared to the positive control group. In order to determine if bamboo salt had anti-diabetic activity, rats in which diabetes had been induced by streptozotocin (45 mg/kg, i.m.) were treated daily with bamboo salt A, crude salt, and reagent-grade NaCl (0.2, 1.0, and 2.0 g/kg, p.o.) for 28 days using insulin (50 U/kg, s.c..) as a positive control. Blood samples were taken and analyzed at 1,2, and 4 weeks after the starting date. Bamboo salt did not cause any decreasing effect on the blood glucose levels. These results clearly demonstrated that bamboo salt A did not exert anti-cancer, anti-hypertensive, or anti-diabetic activities in the present experimental animals.

• Korean Journal of Materials Research
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• v.10 no.9
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• pp.601-606
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• 2000

Nickel mono-silicide(NiSi) shows no increase of resistivity as the line width decreases below 0.15$\mu\textrm{m}$. Furthermore, thin silicide can be made easily and restrain the redistribution of dopants, because NiSi in created through the reaction of one nickel atom and one silicon atom. Therefore, we investigated the deposition condition of Ni films, heat treatment condition and basic properties of NiSi films which are expected to be employed for sub-0.15$\mu\textrm{m}$ class devices. The nickel silicide film was deposited on the Si wafer by using a dc-magnetron sputter, then annealed at the temperature range of $150~1000^{\circ}C$. Surface roughness of each specimen was measured by using a SPM (scanning probe microscope). Microstructure and qualitative composition analysis were executed by a TEM-EDS(transmission electron microscope-energy dispersive x-ray spectroscope). Electrical properties of the materials at each annealing temperature were measured by a four-point probe. As the results of our study, we may conclude that; 1. SPM can be employed as a non-destructive process to monitor NiSi/NiSi$_2$ transformation. 2. For annealing temperature over $800^{\circ}C$, oxygen pressure $Po_2$ should be kept below $1.5{\times}10^{-11}torr$ to avoid oxidation of residual Ni. 3. NiSi to $NiSi_2$ transformation temperature in our study was $700^{\circ}C$ from the four-point probe measurement.