• Nuclear Engineering and Technology
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• v.1 no.1
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• pp.33-38
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• 1969

Determinations of the isotopic contents of U$^{235}$ and U$^{238}$ in ten uranium samples containing 0.72-89.70 at % U$^{235}$ were carried out in two ways utilizing high resolution Ge (Li) gamma-ray spectrometer. One method is based upon the fact that the intensity of 185.5 kev gamma-ray vary linearly with U$^{235}$ content for a given geometry. Another method applied for the direct determination of the U$^{235}$ / U$^{238}$ isotopic ratios is the precision gamma-ray spectrometric analysis of reactor irradiated uranium samples after allowing a fixed cooling time for one hour. The results obtained by both methods well agree with the values calculated from the isotopic contents of highly enriched original uranium samples measured by mass spectrometer. The precision obtained was well below 5% for most of the isotopic ratios investigated.

• Transactions of the Society of Information Storage Systems
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• v.1 no.1
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• pp.34-41
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• 2005

We report some recent results in the rewritable Blu-ray Disc with enhanced overwrite cyclability by using the growth dominant eutectic based Ge(Sb70Te30)+Sb recording layer, GeN interface layer and write strategy optimization. We have developed phase-change optical media with appropriate write strategy for 36(i.e., 1X)-72Mbps(i.e., 2X) dual speed Blu-ray Disc system and fur the future high speed optical data storage. For recording layer, eutectic-based Ge(Sb70Te30)+Sb material was used and Sb/Te ratio and Ge content were optimized to obtain proper erasability and archival stability of recorded amorphous marks. The recording layer is wrapped up in GeN interface layers to obtain overwrite cyclability and higher crystallization speed. In addition, we designed appropriate write strategy so called Time-Shifted Multipulse (TSMP) write strategy where starting position of multipulse parts are shined from reference clock. With this write strategy, the jitter characteristics of the disc was improved and we found that leading edge jitter was improved much more than trailing edge jitter in 1X-2X speed recording. Finally, we investigated the higher speed feasibility of 144Mbps(i.e., 4X) by adopting some elemental doping to the eutectic based Ag-In-Sb-Te recording layer and structural optimization of constitution layers in Blu-ray Disc. In the paper, we report the effect of Sn addition for the feasibility of higher speed recording. The addition of Sn shows increases of the crystallization speed of phase change recording layer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.380-386
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• 2007

This study was conducted to clarify the effective application method, uptake, and translocation of germanium(Ge) in mungbean plants. The foliar application of liquid Ge at 7 mg/l during the flowering period, seeds containing 38.7, $14.1{\mu}g/kg$ of Ge, from the first and second harvesting. It had 2.5 and 2.3 times more Ge than the seeds raised by using granule Ge at 7 mg/kg with basal fertilization. The foliar application of Ge at 3.5, 7, 14 and 28 mg/l during the flowering period, yielded a relatively high record of seeds containing $14.9{\sim}77.8{\mu}g/kg$ and $6.9{\sim}26.7{\mu}g/kg$ of Ge, from the first and second harvesting. However, seeds from the first harvesting contained $2.2{\sim}4.1$ times more Ge than the seeds of from the second harvesting. On the other hand, seeds from first and second harvesting of the non-treatment group Ge contained 1.9 and $3.2{\mu}g/kg$, respectively. When the foliar application of Ge at 7 mg/l was conducted two or three times, the Ge content of the seeds in the first to third harvesting were all over $20{\mu}g/kg$. This indicates that a certain level of Ge can be accumulated. In seeds of mungbean containing $96{\mu}g/kg$ of Ge, cotyledon had $138{\mu}g/kg$ of Ge, which was 79% more than seed coat per unit weight. The growth and quantity of mungbean was not significantly different according to the formulation of Ge, the concentration and the frequency of foliar application of Ge used for in study.

• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.281-286
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• 2015

This study was carried out to investigate the effects of cultural systems on growth, vitamin C, amino acid content, and yield of Peucedanum japonicum grown in artificial light plant factory. Treatments were given with Nutrient Film Technique (NFT), Medium (Perlite), and Aeroponics. Plant height was the highest in NFT system as 10.2cm, and was the shortest in Perlite as 8.9cm. Fresh leaf weight was the high in order of Perlite, NFT, and Aeroponics. Total phenolic compounds was different from cultural systems in order of Aeroponics as $117.84mg{\cdot}100g^{-1}\;GE$, NFT as $98.57mg{\cdot}100g^{-1}\;GE$ and Perlite as $74.62mg{\cdot}100g^{-1}\;GE$. Total flavonoid content of Aeroponics is $0.12mg{\cdot}100g^{-1}$ but that of NFT and Perlite treatments is not detected. Vitamin C content in Aeroponics as $108.23mg{\cdot}100g^{-1}$ was significant different from Perlite as $88.05mg{\cdot}100g^{-1}$ as and NFT $80.83mg{\cdot}100g^{-1}$. Total dietary fiber content was higher Aeroponics than Perlite and NFT. Cystein content was the highest in Aeroponics as $46.76mg{\cdot}100g^{-1}$ and methione content was the lowest in Perlite as $75.64mg{\cdot}100g^{-1}$. Mineral content of leaves was high in order of K, Ca, P and Mg in all treatments.

• Polymer(Korea)
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• v.34 no.6
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• pp.588-593
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• 2010

New seven acrylic monomers with covalently bonded silicon, germanium, and tin were prepared for high refractive index materials. The monomers were copolymerized with a cross-linkable comonomer (Trimer) to prepare UV-films for optical characterization. The refractive index of the copolymers increased in proportion to the monomer content and extrapolated to determine that of homopolymer. $Ph_3Si$, $Ph_3Ge$, and $Ph_3Sn$ groups contributed to increase the refractive index of acrylic polymer, in which $Ph_3Sn$ was more effective than $Ph_3Ge$. The index increment confidently occurred with $Bu_3Sn$ attachment in comparison with aliphatic acrylic polymers. $Ph_3SnS$-attached acrylate polymer showed a refractive index of 1.671 at 589 nm. The index change was similarly observed at various different wavelengths (656, 830, 1310, and 1550 nm).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.4
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• pp.314-320
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• 1998

In this study, we have investigated crystallization properties of $Te_x(Sb_{85}Ge_{15})_{100-x}$ (x=0.3, 0.5, 1.0) thin films prepared by thermal evaporation. The change of reflectance according to phase change from amorphous to crystalline phases with annealing and exposure of diode laser is measured b the n&k analyzer and the surface morphology between amorphous and crystalline phase is analyzed by SEM and AFM. The difference in reflectance($\DeltaR$) between amorphous and crystalline phase appears approximately 20% at the diode laser wavelength, 780nm in all prepared films. Especially, the reflectance difference,$\DeltaR$ comes up to about 30% in $Te_{0.5}(Sb_{85}Ge_{15})_{99.5}$ thin film. Also, amorphous-to-crystalline phase change is observed in all prepared films. As a result of the measurement of the reflectance using diode laser, the reflectance is increased in proportion to the laser power and exposure time in all films. As a result of observing each film with the SEM and AFM, the surface morphology of the annealed and the exposed films are evidently increased than those of as-deposited films. The fast crystallization is occurred by increasing in Te content. Therefore, we conclude that the $Te_{0.5}(Sb_{85}Ge_{15})_{99.5}$ and $Te_1(Sb_{85}Ge_{15})_{99}$ thin films can be evaluated as an attractive optical recording medium with high contast ratio and fast erasing time due to crystallization.

• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.16-23
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• 2016

This study was carried out to investigate the effects of artificial light sources on growth and yield of hydroponically grown Peucedanum japonicum in plant factory. Treatments were composed with; florescent lamp(FL) as control, and LED lights; R:B(2:1, RB), R:B:W(2:1:3, RBW), and R:B:G:W(2:1:0.5:3, RBGW). Plant height of RBGW and FL treatments were superior to RB and RBW. Leaf weight of RBW and RB were superior to FL and RBGW. There were no significant difference of leaf length and thickness among the treatments. Lightness of leaves was same tendency with plant height. Total phenolic compound content was the high in order of RB as $105.77mg{\cdot}100g^{-1}$ GE, RBW as $92.52mg{\cdot}100g^{-1}$ GE, FL as $89.08mg{\cdot}100g^{-1}$ GE, and RBGW $82.00mg{\cdot}100g^{-1}$ GE. Total flavonoids were not detected in all treatments. Vitamin C content was the highest in RB and the lowest in FL. Total dietary fiber were the highest in FL and the lowest in RBGW. There was no significant difference cystein and methionine contents among the treatments. Concludely, yield, total phenolic compounds, and vitamin C content was high in RBW and RB. We reached conclusion that RBW is best artificial light source considering yield, functionality and eye fatigability when work. We recommend to further study LED pulse and duty rates for increasing functionality.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.6
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• pp.880-883
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• 2003

The objective of this study was to measure performance of young broiler chickens fed three varieties of high-oil corn (HOC 1, 2, and 3) compared with eight varieties of normal corn (NC). HOC varieties contained about 80% more oil than NC (average crude fat; 6.71% vs 3.72%) and about 29% more protein (average CP; 9.54% vs 7.38%). Each experimental diet was formulated with the same amount (55.205%) of each corn hybrid. Experiment 1 had by six dietary treatments (HOC1 and five NC varieties, 360 chickens) and Experiment 2 had five treatments (HOC2, HOC3, and three NC varieties, 250 chickens). In Exp. 1, for feed efficiency (F/G), the treatment contained HOC1 had better performance (p<0.05) than other NC varieties except NC5. As expected, there was no significant difference in average daily feed intake (p>0.05) among dietary treatments. The dietary treatment of HOC1 gave an improvement of 4.3% in F/G that came from 6% higher gross energy (GE) value of HOC1. Compared with Exp. 2, the dietary treatments contained HOC hybrids gave 4.4% higher F/G than NC dietary treatments, which came from a 5% increase in GE value. HOC varieties had superior nutrients content to NC for poultry, due to the fact that HOC contained higher concentrations of energy, protein, lysine, and methionine, thus improving growth and F/G.

• Mass Spectrometry Letters
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• v.5 no.2
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• pp.57-61
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• 2014

A gravimetric standard addition method combined with internal standard calibration has been successfully developed for the accurate analysis of total arsenic in a laver candidate reference material. A model equation for the gravimetric standard addition approach using an internal standard was derived to determine arsenic content in samples. Handlings of samples, As standard and internal standard were carried out gravimetrically to avoid larger uncertainty and variability involved in the volumetric preparation. Germanium was selected as the internal standard because of its close mass to the arsenic to minimize mass-dependent bias in mass spectrometer. The ion signal ratios of $^{75}As^+$ to $^{72}Ge^+$ (or $^{73}Ge^+$) were measured in high resolution mode ($R{\geq}10,000$) to separate potential isobaric interferences by high resolution ICP/MS. For method validation, the developed method was applied to the analysis of arsenic content in the NMIJ 7402-a codfish certified reference material (CRM) and the result was $37.07mg{\cdot}kg^{-1}{\pm}0.45mg{\cdot}kg^{-1}$ which is in good agreement with the certified value, $36.7mg{\cdot}kg^{-1}{\pm}1.8mg{\cdot}kg^{-1}$. Finally, the certified value of the total arsenic in the candidate laver CRM was determined to be $47.15mg{\cdot}kg^{-1}{\pm}1.32mg{\cdot}kg^{-1}$ (k = 2.8 for 95% confidence level) which is an excellent result for arsenic measurement with only 2.8 % of relative expanded uncertainty.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.413-418
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• 1998

There are several types of salts that classifed into raw salts(Chunil salt, Saeng salt), purified salts (NaCl reagent grade, Hanju salt) and processed salts(Gueun salt, Saeng kum, Bamboo salt) in Korea. Their major element is NaCl but raw salt from sea water contains other minerals such as K, Mg and S. Mineral contents of the various kinds of salt analyzed with ICP-AES and AAS were different, especially on the contents of K, Mg and Ca. Chunil salt was abundant in Ca(1,037ppm), K(3,707ppm), Mg(10,266ppm) and S(7,459ppm), and salt water from the Chunil salt contained small amounts of Pb, Al, Cr and Hg. Processed salts contained high levels of Ca, K, Mg and Fe. Especially, high levels of K, P, Fe and Ge were detected in bamboo salt. Purified salts showed regular crystal form and raw salts exhibited irregular crystal form under the SEM. The processed salts were not crystal form, but fused and irregular round form.