• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.495-500
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• 2015

Background: Published studies have reported relationships between X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism and lung cancer risk in Chinese population. However, the epidemiological results remained controversial. The objective of this study was to clarify the association of XRCC1 Arg399Gln polymorphism with lung cancer risk in the Chinese population. Materials and Methods: Systematic searches were performed through the database of Medline/Pubmed, Web of Science, Embase, CNKI and WanFang Medical Online. Odds ratios (ORs) with 95% confidence interval (95%CI) were calculated to estimate the strength of the association. Results: Overall, we observed an increased lung cancer risk among subjects carrying XRCC1 codon 399 Gln/Gln genotype (OR=1.36, 95%CI: 1.09-1.71) in the Chinese population on the basis of 19 studies with 5,416 cases and 5,782 controls. We did not observe any association between XRCC1 codon 399 Arg/Gln and Arg/Gln+Gln/Gln polymorphisms and lung cancer risk (OR=1.00, 95%CI: 0.92-1.08 and OR=1.05, 95%CI: 0.97-1.13, respectively). Limiting the analysis to studies with controls in agreement with Hardy-Weinberg equilibrium (HWE), we observed an increased lung cancer risk among subjects carrying XRCC1 codon 399 Gln/Gln genotype (OR=1.18, 95%CI: 1.01-1.38). When stratified by source of control, we observed an increased lung cancer risk among subjects carrying XRCC1 codon 399 Arg/Gln+Gln/Gln genotype on the basis of hospitalized patient-based controls (OR=1.21, 95%CI: 1.04-1.42) and among subjects carrying XRCC1 codon 399 Gln/Gln genotype on the basis of healthy subject-based controls (OR=1.22, 95%CI: 1.04-1.43). Conclusions: Our findings indicated that certain XRCC1 Arg399Gln variants might affect the susceptibility of lung cancer in Chinese population. Larger sample size studies are required to confirm our findings.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.2 no.1
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• pp.10-19
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• 1992

Mn - Zn Ferrite has physical properties of the high initial permeability, saturation magnetic flux density, and low loss factor as a representative magnetic material of soft ferrites, in addition the mechanical property is excellent as a single crystal. Therefore it is important electronic components and used for VTR Head. Mn - Zn Ferrite single crystals with the diameter 8mm were grown in atmosphere mixed with $O_2$ and Ar gas by the Floating Zone(FZ) method that impurities can not be incorporated to the crystals because of not-using the crucible to put in the melt, and the sharp temperature gradient results from making a focus at one point utilizing the infrared ray emitted from the halogen lamp as a heat source. During the crystal growing, the highest temperature of melting area was maintained to be $1650^{\circ}C$, growth rate and rotation rate were 10 mm/hr, 20 rpm respectively. The phases and the growth directions of crystals were determined from the analysis of X RD patterns, Laue, TEM diffraction patterns and etch pit shapes were observed by the optical microscope through the chemical etching. The corelation of optimum conditions for acquiring the better crystals was found out with the growth rate, the length and diameter of melt at the interface according to the diameter of feed rod, and the patterns of growing interface also studied.

• Carbon letters
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• v.28
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• pp.31-37
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• 2018

This paper examines a simple one-step and catalyst-free method for synthesizing carbon nanoparticles from aliphatic alcohols and n-hexane with linear molecule formations by using a stable solution plasma process with a bipolar pulse and an external resistor. When the external resistor is adopted, it is observed that the current spikes are dramatically decreased, which induced production of a more stable discharge. Six aliphatic linear alcohols (methanol-hexanol) containing carbon with oxygen sources are studied as possible precursors for the massive production of carbon nanoparticles. Additional study is also carried out with the use of n-hexane containing many carbons without an oxygen source in order to enhance the formation of carbon nanoparticles and to eliminate unwanted oxygen effects. The obtained carbon nanoparticles are characterized with field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, and Raman spectroscopy. The results show that with increasing carbon ratios in alcohol content, the synthesis rate of carbon nanoparticles is increased, whereas the size of the carbon nanoparticles is decreased. Moreover, the degree of graphitization of the carbon nanoparticles synthesized from 1-hexanol and n-hexane with a high carbon (C)/oxygen (O) ratio and low or no oxygen is observed to be greater than that of the carbon nanoparticles synthesized from the corresponding materials with a low C/O ratio.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.11
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• pp.923-932
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• 2002

A stoichiometric mixture of evaporating materials for CdIn$\_$2/S$\_$4/ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CdIn$\_$2/S$\_$4/ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by hot wall epitaxy(HWE) system. The source and substrate temperatures were 630 $\^{C}$ and 420 $\^{C}$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction(DCXD). The carrier density and mobility of CdIn$\_$2/S$\_$4/ single crystal thin films measured from Hall effect by van der Pauw method are 9.01$\times$10$\^$16/ cm$\^$-3/ and 219 ㎠/V$.$s at 293 K, respectively. From the optical absorption measurement, the temperature dependence of energy band gap on CdIn$\_$2/S$\_$4/ single crystal thin films was found to be Eg(T) ＝ 2.7116 eV - (7.74 $\times$ 10$\^$-4/ eV) T$\^$2//(T＋434). After the as-grown CdIn$\_$2/S$\_$4/ single crystal thin films was annealed in Cd-, S-, and In-atmospheres, the origin of point defects of CdIn$\_$2/S$\_$4/ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. The native defects of V$\_$cd/, V$\_$s/, Cd$\_$int/ and S$\_$int/ obtained by PL measurements were classified as donors or accepters type. And we concluded that the heat-treatment in the S-atmosphere converted CdIn$\_$2/S$\_$4/ single crystal thin films to an optical p-type. Also, we confirmed that In in CdIn$\_$2/S$\_$4/GaAs did not from the native defects because In in CdIn$\_$2/S$\_$4/ single crystal thin films existed in the form of stable bonds.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.10
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• pp.829-838
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• 2007

The stochiometric mix of evaporating materials for the $CdGa_2Se_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, $CdGa_2Se_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $630^{\circ}C$ and $420^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD).The carrier density and mobility of $CdGa_2Se_4$ single crystal thin films measured from Hall effect by van der Pauw method are $8.27{\times}10^{17}\;cm^{-3},\;345\;cm^2/V{\cdot}s$ at 293 K. respectively. The temperature dependence of the energy band gap of the $CdGa_2Se_4$ obtained from the absorption spectra was well described by the Varshni's relation, $Eg(T)\;=\;2.6400\;eV\;-\;(7.721{\times}10^{-4}\;eV/K)T^2/(T+399\;K)$. After the as-grown single crystal $CdGa_2Se_4$ thin films were annealed in Cd-, Se-, and Ga -atmospheres, the origin of point defects of single crystal $CdGa_2Se_4$ thin films has been investigated by PL at 10 K. The native defects of $V_{Cd}$, $V_{Se}$, $Cd_{int}$, and $Se_{int}$ obtained by PL measurements were classified as donors or accepters. We concluded that the heat-treatment in the Cd-atmosphere converted single crystal $CdGa_2Se_4$ thin films to an optical p-type. Also, we confirmed that Ga in $CdGa_2Se_4/GaAs$ did not form the native defects because Ga in single crystal $CdGa_2Se_4$ thin films existed in the form of stable bonds.

• Journal of the Korean Society of Radiology
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• v.9 no.5
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• pp.323-329
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• 2015

This study is aimed at assessing whether dynamic wedge filters are appropriate to be used instead of physical wedge filters. The X-ray energy generated from linear accelerator is commercialize 6 MV and 10 MV. $15^{\circ}$, $30^{\circ}$, $45^{\circ}$, and $60^{\circ}$ of physical wedge filter was irradiated by dose rate 100, 200, 300, 400, 500, and 600 MU/min for each angle and for comparison with a dynamic wedge filter, irradiate 96 times under the same conditions. The measurement conditions are as 100 cm source-film distance and $10{\times}10cm$ irradiated surface. A developed film was scanned and analyzed after a calibration through a dose analysis program and the dose rate was compared after calculating the standard deviation. Dynamic wedge filters make dose, scattered rays and treatment time reduced and very useful due to less irradiated doses to patients. The errors at each dose rate under the same conditions were irrelevant. Thus, treatment based on a high dose rate depending on the patient is expected to be feasible.

• Economic and Environmental Geology
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• v.30 no.1
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• pp.35-49
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• 1997

The coal formation of the Deokpyeong area are interbedded along metapelites of the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with small amounts of biotite, chlorite, pyrite and barite. The ratios of $SiO_2/Al_2O_3$, $Al_2O_3/Na_2O$ and $K_2O/Na_2O$ of the coaly metapelite are variable and wide range from 1.80 to 10.21, from 27.8 to 388.8 and from 7.6 to 61.8, respectively. These coal formation were deposited in basin of marine environments, and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of $Al_2O_3$ versus La, La against Ce, the ratios of La/Ce (0.19 to 0.99) and Th/U (0.02 to 4.75). These rocks also show much variation in $La_N/Yb_N$ (1.19 to 22.89), Th/Yb (0.14 to 21.43) and La/Th (0.44 to 13.67), and their origin is explained by derivation from a mixture of sedimentary and igneous rocks. The wide range in trace and REE element characteristics as Co/Th (0.12 to 2.78), La/Sc (0.33 to 10.18), Sc/Th (0.57 to 5.73), V/Ni (8 to 2347), Cr/V (0.02 to 0.67) and Ni/Co (1.56 to 32.95) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation. Deep to pale green barium-vanadium muscovites (vanadium-oellacherite) have been found in this coal formations. Modes of occurrence and grain size of muscovite are heterogeneous, but most of the barium and vanadium-bearing muscovites occur along the boundaries between graphite and quartz grains, ranging from 200 to $350{\mu}m$ in length and from 40 to $60{\mu}m$ in width. Results of X-ray diffraction data of the minerals characterized to be monoclinic system with $a=5.249{\AA}$, $b=8.939{\AA}$, $c=20.924{\AA}$ and ${\beta}=95.894^{\circ}$. Representative chemical formula of the muscovite was $(Na_{0.09}K_{1.44}Ba_{0.46})(Al_{2.75}Ti_{0.07}V_{0.56}Fe_{0.08}Mg_{0.50})(Si_{6.12}Al_{1.88})O_{22}$. The V possibly substitute octahedral Al, and the Ba is coupled substitution of $K^+Si^{4+}=Ba^{2+}Na^+Ca^{2+}$, which compositional ranges of V and Ba are from 0.42 to 0.69 and from 0.34 to 0.56 based on $O_{22}$, respectively. Formation mechanism of the barium-vanadium muscovites in the coaly metapelite is shown that the formed by high pressure and temperature from regional metamorphism origanated during diagenesis at the interface between a basinal brine and organic matter.

• Journal of Sensor Science and Technology
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• v.13 no.2
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• pp.157-167
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• 2004

A stoichiometric mixture of evaporating materials for $CuAlSe_{2}$ single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, $CuAlSe_{2}$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were $680^{\circ}C$ and $410^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of $CuAlSe_{2}$ single crystal thin films measured with Hall effect by van der Pauw method are $9.24{\times}10^{16}cm^{-3}$ and $295cm^{2}/V{\codt}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $CuAlSe_{2}$ obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}(T)$ = 2.8382 eV - ($8.68{\circ}10^{-4}$ eV/K)$T^{2}$/(T + 155 K). The crystal field and the spin-orbit splitting energies for the valence band of the $CuAlSe_{2}$ have been estimated to be 0.2026 eV and 0.2165 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}so$ definitely exists in the ${\Gamma}_{5}$ states of the valence band of the $CuAlSe_{2}$. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1-}$, $B_{1-}$, and $C_{1-}$ exciton peaks for n = 1.

• Journal of Preventive Medicine and Public Health
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• v.10 no.1
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• pp.3-15
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• 1977

In order to find out health problems among inhabitants in slum areas in Kwanak-Ku, Seoul, a series of health survey was conducted upon 510 households by interview from March to December, 1976. The results obtained were as follows: 1. Employments of householders were unstable; Out of 508 householders, 164(32.3%) were unemployed and 184 (36.2%) were daily or temporary employees. 2. Average number of households per house was 2.0 and average area of residential room per person was $4.0m^2$. 3. 476(93.3%) out of 510 households were supplied with tap water and rest of them made use of ground water as a source of drinking water. 4. Only 279(18.3%) out of 1527 live births were delivered at medical facilities, 496(32.7%) were at home attended by doctors or midwives and 358(25.1%) took prenatal care. The above findings were worse in urban slum area than in other urban area of relatively high economic level, but were better than in rural area of less medical facilities. 5. Initiation of treatment were delayed until their illnesses were advanced in most of the households, 472(92.5%) out 510. In the early stage of the illness, 131(25.6%) of the house-holds sought physicians in their clinics or general hospitals and 250 (40.9%) visited chemists, to toy drugs at first hand. Frequency of visits to physician increased to 52.8% as the disease aggravated in later stages. 6. Cost of medical expenditure per household amounted to 815 won, and was paid to, in the order of chemists, physicians, chinese herb stores, chinese herb doctors. 7. Concerning the health knowledge of the inhabitants, 273(53.9%) out of 506 respondents were aware of the infectivity of pulmonary tuberculosis, and 68(13.4%) of them checked regularly their chest findings by X-ray at least once every two years. 8. As for the family planning, although 448(87.3%) out of 510 respondents were in favor of it, 215 (41.8%) of them were actually practicing contraception. 9. About 40.6% (125 respondents) of them obtained information and knowledge concerning contraception through personal contact with family planning workers. 10. Nutritional status of housewives was generally poor: 49(38.3%) out of 128 housewives were found to be anemic and average serum protein level was $7.5{\pm}0.82g/dl$.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.2
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• pp.45-50
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• 2015

Compositionally graded AlGaN epilayer was grown by HVPE (hydride vapor phase epitaxy) on (0001) c-plane sapphire substrate. During the growth of graded AlGaN epilayer, the temperatures of source and the growth zone were set at $950^{\circ}C$ and $1145^{\circ}C$, respectively. The growth rate of graded AlGaN epilayer was about 100 nm/hour. The changing of Al contentes was investigated by field emission scanning electron microscope (FE-SEM) and energy dispersive spectroscopy (EDS). From the result of atomic force microscope (AFM), the average of roughness in 2 inch substrate of graded AlGaN epilayer was a few nanometers scale. X-ray diffraction (XRD) with the result that the AlGaN (002) peak ($Al_{0.74}Ga_{0.26}N$) and AlN (002) peak were appeared. It seems that the graded AlGaN epilayer was successfully grown by the HVPE method. From these results, we expect to use of the graded AlGaN epilayer grown by HVPE for the application of electron and optical devices.