• Analytical Science and Technology
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• 제5권1호
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• pp.17-24
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• 1992

Germanium(IV) was determinated in perchloric acid supporting electrolyte solution containing catechol derivates 3.4-dihydroxy benzoic acid, 3.4-dihydroxy benzaldehyde, adrenaline by hanging mercury electrode(HMDE) of anodic stripping polarography. And then to apply this experimental method for determination of germanium(IV) in natural samples. Germanium(IV) was determinated $300{\mu}g/L$ in ginseng and $210{\mu}g/L$ in mineral water.

• Korean Chemical Engineering Research
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• 제55권2호
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• pp.275-278
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• 2017

Heterogeneous semiconductor composites have been widely used to establish high-performance microelectronic or optoelectronic devices. During a deposition of silicon atoms on silicon/germanium compound surfaces, germanium (Ge) atoms are segregated from the substrate to the surface and are mixed in incoming a silicon layer. To suppress Ge segregation to obtain the interface sharpness between silicon layers and silicon/germanium composite layers, approaches have used silicon hydride gas species. The hydrogen atoms can play a role of inhibitors of silicon/germanium exchange. However, there are few kinetic models to explain the hydrogen effects. We propose using segregation probability which is affected by hydrogen atoms covering substrate surfaces. We derived the model to predict the segregation probability as well as the profile of Ge fraction through layers by using chemical reactions during silicon deposition.

• Korean Journal of Medicinal Crop Science
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• 제7권1호
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• pp.11-15
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• 1999

The uptake of germanium(Ge) by health foodstuffs was interesting because of a therapeutic effect of organic germanium. Germanium contents in different plant parts of the cultivated Korean Angelica keiskej Koidz in several growing districts were determined by square wave anodic stripping voltammetry. Experimental conditions in germanium determination from Angelica kejskej Koidz were as follows : deposition time; 20 sec, deposition potential; -0.9 volts vs Ag/AgCl, and frequency; 100 Hz in 0.1M\;HClO_4, supporting electrolyte solution at pH 2.43 containing $1.5\;{\times}\;10^5\;M$ pyrocatechol violet. Calibration curve showed a good lineality in the range of 0.4 ppb to 2.0 ppm and the detection limit was 0.08 ppb. There was a large difference in content according to growing districts ranging from 102 to 386ppm. Germanium content in leaf parts was much higher than that in stems.

• Korean Journal of Environmental Agriculture
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• 제24권4호
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• pp.404-408
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• 2005

In order to obtain the basic information far agricultural utilization of Germanium (Ge), the growth characteristics and germanium absorption in lettuce were investigated with different concentration of germanium in soil. This experiment was carried out in the waster pot $(15,000^{-1}a)$. Germanium concentrations in soil for lettuce cultivation were maintained at 0.26, 2.0, 4.0, 6.0 and $8.0mg\;kg^{-1}$, respectively. The content of germanium in lettuce was increased with the increase of germanium concentration in soil. When lettuce was cultivated on soil supplemented with Ge $8.0mg\;kg^{-1}$, germanium phytotoxicity (reduction of plant height, No. of leaf and fresh weight) was not observed. When lettuce was cultivated on soil supplemented with Ge 4.0 and $8.0mg\;kg^{-1}$, it germanium content were found 0.75 and $1.27mg\;kg^{-1}$, respectively. Germanium absorption efficiency of lettuce was not different by germanium concentrations in the soil. When lettuce was cultivated on soil supplemented with Ge 2.0, 4.0 and $8.0mg\;kg^{-1}$, its absorption germanium efficiency was found 0.05, 0.04 and 0.03%, respectively. Germanium contents in different parts of lettuce cultivated with Ge $8.0mg\;kg^{-1}$ were $0.65mg\;kg^{-1}$ on inner leaf and $1.59mg\;kg^{-1}$ on outer leaf.

• Korean Journal of Poultry Science
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• 제30권4호
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• pp.275-280
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• 2003

This study conducted to investigate the effect of dietary germanium biotite by protein level in laying hen diets. One hundred forty four, 51 weeks old ISA brown commercial layer, were used in experiment. Dietary treatments were 1) low protein diet(LPD), 2) high protein diet(HPD), 3) LPD-GB(LPD + 1.0% germanium biotite) and 4) HPD-GB(HPD + 1.0% germanium biotite). Henday egg production tended to be increased as the concentration of protein in diets increased with significant difference(P<0.01). Egg weight tended to decrease by increasing of supplementation germanium biotite in the diets(P<0.01). Egg shell breaking strength was not influenced by germanium biotite supplementation(P>0.05). Large band of egg decrease as increasing of supplementation germanium biotite in the diets(P<0.02). Sharp and middle band of egg were not influenced by germanium biotite supplementation. Egg yolk index tended to decrease as increasing of supplementation germanium biotite in the diets(p<0.01). Fecal propionic acid(P<0.01) and butyric acid(P<0.03) were decrease as the concentration of germanium biotite in the diet was increased. Also, butyric acid increased as the concentration of protein in diets increased with significant difference(P<0.02). Supplementation germanium biotite in the diet reduced the fecal acetic acid(P<0.01). Fecal $NH_3$-N of hens fed HPD-GB diet was decreased(P<0.05) compared to that LPD-GB diet. In conclusion, germanium biotite supplementation to layer diets can reduce fecal volatile fatty acid compabebts.

• Journal of the Korean Chemical Society
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• 제40권2호
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• pp.109-116
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• 1996

A matrix modification was studied for the determination of trace germanium in mineral waters by electrothermal atomic absorption spectrophotometry (ET-AAS). For this, the type and quantity of modifier as well as the use of auxiliary modifier were investigated to realize the efficient modification. Germanium suffers from low sensitivity and poor reproducibility in ET-AAS determination because of the premature loss of germanium via volatile germanium monoxide formation when heated in the presence of carbon. Therefore, the addition of a matrix modifier is necessary to stablize the germanium, thermally and chemically. By the addition of palladium (10 ${\mu}g/mL)$ as a single modifier to the sample containing 500 ng/mL germanium, the charring temperature could be raised from 800 to $1000^{\circ}C$, and its absorbance was also increased, but the atomization temperature was not raised. In this case, the absorbance of germanium was not changed in the range of 10∼70 ${\mu}g/mL$ of palladium added. On the other hand, it was considered that the use of a mixed modifier could modifiy the matrix more effectively than with a single modifier. The best results were obtained by using 1% ammonium hydroxide as an auxiliary modifier together with 10 ${\mu}g/mL$ palladium. The charring temperature could be raised from 800 to $1100^{\circ}C$, without any change of the atomization temperature. With above optimum conditions, the trace amount of germanium in several mineral waters were determined by a calibration curve method, and good recoveries of more than 95% were also obtained in the samples in which a given amount of germanium was spiked. The detection limit of this method was about 6.9 ng/mL.

• Analytical Science and Technology
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• 제14권1호
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• pp.34-43
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• 2001

The present work is aimed to evaluate the conditions of the hydride generation (HG) for germanium analysis by inductively coupled plasma (ICP)-atomic emission spectrometry (AES). Twelve different kinds of acids were used such as phosphoric, hydrochloric, nitric, sulfuric, perchloric, boric, tartaric, malic, oxalic, tannic, citric, and acetic acid. It was found that phosphoric acid yielded the maximum efficiency of hydride generation. Also, efficient hydride generation was obtined with the buffer solutions containing phosphate ions over a wide range of pH. In addition, in the presence of phosphoric acid the interference caused by metals was suppressed in the hydride generation of germanium. As the concentrations of a reducing agent and a stabilizing increased the hydride generation efficiency and the acid concentration proviaing the maximum intensity were increased. By using an analytical method developed in this study, the contents of germanium in water and rock samples were determined. The detection limit of germanium in the presence of phosphoric acid was $0.03{\mu}g/L$.

• Korean Journal of Medicinal Crop Science
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• 제3권1호
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• pp.45-49
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• 1995

This study was carried out to examine the germanium contents of Angelica keiskei Koidz. and A. acutiloba Kitagawa and to intend to increase its contents while those leaf explants were culturing on MS medium supplemented with organic and inorganic germanium. Ge content of Agelica keiskei Koidz. was 2.1 times higher than that of A. acutiloba Kitagawa. Digestion was done quickly at high temperature, but Ge content was decreased. Callus formation of A. acutiloba Kitagawa was better than that of A. keiskei Koidz. Callus formation of both plants was good in order of pH 5.7, pH 5.4, and pH 6.0. But shoots from callus were formed frequently in A. keiskei Koidz., especially at pH 5.7. Callus formation of both plants was good up to 5 ppm of inorganic ($germanium(GeO_2),$ retarded at 10 ppm, and rarely formed at 100 ppm, but was good up to 10ppm of organic germanium retarded at 50 ppm and formed some-what even at 100 ppm.

• Proceedings of the Korean Nutrition Society Conference
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• 한국영양학회 1999년도 춘계학술대회 초록
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• pp.74-74
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• 1999

• Korean Journal of Materials Research
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• 제18권6호
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• pp.302-306
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• 2008

Polycrystalline germanium (Ge) thin films were grown by metal organic chemical vapor deposition (MOCVD) using tetra-allyl germanium [$Ge(allyl)_4$], and germane ($GeH_4$) as precursors. Ge thin films were grown on a $TiN(50nm)/SiO_2/Si$ substrate by varying the growth conditions of the reactive gas ($H_2$), temperature ($300-700^{\circ}C$) and pressure (1-760Torr). $H_2$ gas helps to remove carbon from Ge film for a $Ge(allyl)_4$ precursor but not for a $GeH_4$ precursor. $Ge(allyl)_4$ exhibits island growth (VW mode) characteristics under conditions of 760Torr at $400-700^{\circ}C$, whereas $GeH_4$ shows a layer growth pattern (FM mode) under conditions of 5Torr at $400-700^{\circ}C$. The activation energies of the two precursors under optimized deposition conditions were 13.4 KJ/mol and 31.0 KJ/mol, respectively.