• Korean Journal of Materials Research
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• v.21 no.10
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• pp.573-579
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• 2011

Highly textured Ag, Al and Al:Si back reflectors for flexible n-i-p silicon thin-film solar cells were prepared on 100-${\mu}m$-thick stainless steel substrates by DC magnetron sputtering and the influence of their surface textures on the light-scattering properties were investigated. The surface texture of the metal back reflectors was influenced by the increased grain size and by the bimodal distribution that arose due to the abnormal grain growth at elevated deposition temperatures. This can be explained by the structure zone model (SZM). With an increase in the deposition temperatures from room temperature to $500^{\circ}C$, the surface roughness of the Al:Si films increased from 11 nm to 95 nm, whereas that of the pure Ag films increased from 6 nm to 47 nm at the same deposition temperature. Although Al:Si back reflectors with larger surface feature dimensions than pure Ag can be fabricated at lower deposition temperatures due to the lower melting point and the Si impurity drag effect, they show poor total and diffuse reflectance, resulting from the low reflectivity and reflection loss on the textured surface. For a further improvement of the light-trapping efficiency in solar cells, a new type of back reflector consisting of Ag/Al:Si bilayer is suggested. The surface morphology and reflectance of this reflector are closely dependent on the Al:Si bottom layer and the Ag top layer. The relationship between the surface topography and the light-scattering properties of the bilayer back reflectors is also reported in this paper.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.289-289
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• 2013

While there are plenty of studies on synthesizing semiconducting germanium nanowires (Ge NWs) by vapor-liquid-solid (VLS) process, it is difficult to inject dopants into them with uniform dopants distribution due to vapor-solid (VS) deposition. In particular, as precursors and dopants such as germane ($GeH_4$), phosphine ($PH_3$) or diborane ($B_2H_6$) incorporate through sidewall of nanowire, it is hard to obtain the structural and electrical uniformity of Ge NWs. Moreover, the drastic tapered structure of Ge NWs is observed when it is synthesized at high temperature over $400^{\circ}C$ because of excessive VS deposition. In 2006, Emanuel Tutuc et al. demonstrated Ge NW pn junction using p-type shell as depleted layer. However, it could not be prevented from undesirable VS deposition and it still kept the tapered structures of Ge NWs as a result. Herein, we adopt $C_2H_2$ gas in order to passivate Ge NWs with carbon sheath, which makes the entire Ge NWs uniform at even higher temperature over $450^{\circ}C$. We can also synthesize non-tapered and uniformly doped Ge NWs, restricting incorporation of excess germanium on the surface. The Ge NWs with carbon sheath are grown via VLS process on a $Si/SiO_2$ substrate coated 2 nm Au film. Thin Au film is thermally evaporated on a $Si/SiO_2$ substrate. The NW is grown flowing $GeH_4$, HCl, $C_2H_2$ and PH3 for n-type, $B_2H_6$ for p-type at a total pressure of 15 Torr and temperatures of $480{\sim}500^{\circ}C$. Scanning electron microscopy (SEM) reveals clear surface of the Ge NWs synthesized at $500^{\circ}C$. Raman spectroscopy peaked at about ~300 $cm^{-1}$ indicates it is comprised of single crystalline germanium in the core of Ge NWs and it is proved to be covered by thin amorphous carbon by two peaks of 1330 $cm^{-1}$ (D-band) and 1590 $cm^{-1}$ (G-band). Furthermore, the electrical performances of Ge NWs doped with boron and phosphorus are measured by field effect transistor (FET) and they shows typical curves of p-type and n-type FET. It is expected to have general potentials for development of logic devices and solar cells using p-type and n-type Ge NWs with carbon sheath.

• Animal Bioscience
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• v.34 no.1
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• pp.93-101
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• 2021

Objective: Temperature could influence protein and amino acid deposition as well as gut microbiota profile and composition. However, the specific effects of ambient temperature on amino acids deposition and gut microbiota composition remain insufficiently understood. Methods: A total of 300 one-day-old Avian broilers were randomly divided into three groups and reared at high, medium, and low temperature (HT, MT, and LT), respectively. Breast muscle and fecal samples were collected for amino acid composition analysis and 16S rRNA gene sequence analysis. Results: Our data showed that compared to the MT group, there was a decrease of muscle leucine and tyrosine (p<0.05), as well as an increase of methionine in the HT group (p<0.05) and a decrease of serine in the LT group. Examination of microbiota shift revealed that at genus level, the relative abundance of Turicibacter and Parabacteroides was increased in the HT group (p<0.05) and that the relative abundances of Pandoraea, Achromobacter, Prevotella, Brevundimonas, and Stenotrophomonas in the LT group were higher than those in the MT group (p<0.05). In addition, there were substantial correlations between microbes and amino acids. In the HT group. Turicibacter was negatively correlated with aspartic acid and tyrosine, whereas Parabacteroides was positively correlated with methionine (p<0.05). In the LT group, there were multiple positive correlations between Achromobacter and arginine, isoleucine or tyrosine; between Prevotella and cysteine or phenylalanine; between Brevundimonas and cysteine; and between Stenotrophomonas and cysteine as well as a negative correlation between Stenotrophomonas and serine. Conclusion: Our findings demonstrated that amino acid content of breast muscle and intestinal microbiota profile was affected by different ambient temperatures. Under heat exposure, augmented abundance of Parabacteroides was correlated with elevated methionine. Low temperature treatment may affect muscle tyrosine content through the regulation of Achromobacter.

• Ocean and Polar Research
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• v.44 no.4
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• pp.297-310
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• 2022

To understand the chemical composition of aerosols in the Cheju-Korea Straits and their contribution to the ocean by deposition, aerosol samples were collected on board R/V Eardo from November 1997 to May 1999. The average concentrations of Al, NO₃^-, non-sea-salt (nss)-SO₄^2-, and NH₄⁺ in aerosols were 2.19, 5.59, 6.16 and 2.08 ㎍ m^-3, respectively. The Al concentration in the high yellow dust period was about 100 times higher than that in the non-yellow dust period. The concentration ratio of NO₃^-/nss-SO₄^2- ranged between 0.47 and 1.5, indicating that the aerosols in the Cheju-Korea Straits are under the effects of NO_x and SO_x emitted from China, Korea and Japan. The equivalent concentration ratio of [NH₄⁺]/[nss-SO₄^2-+ NO₃^-] with the average of 0.58±0.29 indicates that nss-SO₄^2- and NO₃^- are not neutralized by NH₄⁺. A high activity concentration of ²¹⁰Pb with 1.13-1.23 mBq m^-3 was observed during the high yellow dust period, indicating that ²¹⁰Pb is easily adsorbed in the yellow dust originating from the continent of Asia. The distribution of ⁷Be and NH₄⁺ concentrations showed a strong negative linear correlation during the low yellow dust period, April 1998. The total mineral dust flux in the Cheju-Korea Straits was estimated to be 1.21×10⁶ tons yr^-1, accounting for about 12% of the annual sediment discharge via the Nakdong River. The combined annual deposition of NH₄⁺ and NO₃^- was 0.103 mole N m^-2 yr^-1 was estimated to support 4% of the annual primary productivity in the East China Sea.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.7 no.2
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• pp.77-83
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• 2014

Purpose: The purpose of current study was to evaluate the validity of the existing radiological classifications as a diagnostic modality for predicting characteristics of calcific deposition in calcific tendinitis of the shoulder joint. For that purpose, we determined the inter-observer reliability for evaluating diagnostic precisions of the classification and also evaluated diagnostic accuracy of predicting the toothpaste type calcific deposition. Materials and Methods: We performed retrospective study with total 26 patients surgically treated with calcific tendinitis of the shoulder joint from March 2010 to October 2013. Two independent observers reviewed preoperative radiographs of shoulder joints, and classified the characteristics of calcific depositions according to the criteria of Gartner, DePalma and Patte. Cohen's kappa were calculated for each classifications to evaluate inter-observer reliability. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio were determined for type of calcific depositions with Gartner type III, DePalma type I, and Patte type II for predicting toothpaste type calcific deposition. Results: The values of Cohen's kappa were the highest in the classification of Patte, 0.62, and the values for the classifications of DePalma and Gartner were 0.56 and 0.36, respectively. The sensitivities for predicting toothpaste type calcific deposition in Gartner Type III, DePalma type I and Patte type II were 83.3%, 91.7%, and 58.3%, respectively. Specificities were 85.7% 50.0% and 64%, positive likelihood ratios were 5.833, 1.833 and 1.633, negative likelihood ratios were 0.194, 0.167 and 0.648, and diagnostic odds ratios were 30.00, 11.00 and 2.52, respectively. Conclusion: There were no radiologic classifications of calcific tendinitis which has both high precision and accuracy. Further studies with other diagnostic modalities such as ultrasonography are needed for predicting characteristics of calcific deposition in calcific tendinitis of the shoulder joint.

• Journal of Food Hygiene and Safety
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• v.4 no.2
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• pp.133-153
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• 1989

The present study was carried out to investigate the preventive effects of lamprey oil and corn oil on atherosclerotic rats induced by oral administration of cholesterol and vitamin $D_2$. The obtaind results were summarized as fellows; 1. The group, fed only the mixture of cholesterol and vitamin $D_2$ showed the significant increase of total lipid, total cholesterol phospholipid, LDL&HDL-cholesterol in the serum, triglyceride and cholesterol in the heart and the aorta, but the significant decrease of triglyceride in the liver, as comparing with normal control group (p<0.05). The aorta showed the severe damage of disorganization, calcification, necrosis and lipid deposition in the aortic wall. 2. The group, adminstered the mixture of cholesterol and vitamin $D_2$ and fed 15% lamprey oil diet, showed the significant decrease of total lipid, triglyceride, total cholesterol, phospholipid and LDL&VLDL-cholesterol in the serum, triglyceride and cholesterol in the heart and the aorta, but the significant increase of cholesterol in the liver, as comparing with atherogenic control group (p<0.05). The aorta showed slight calcification and no lipid deposition in the aortic wall as comparing with atherogenic control group. 3. The group, administerd the mixture of cholesterol and vitamin $D_2$ and fed 15% corn oil diet, showed the decrease of total lipid, triglyceride and VLDL-cholesterol in the serum, and triglyceride in the heart and the aorta, as comparing with atherogenic control group (p<0.05). The aorta showed calcification and no lipid deposition in the aortic wall. In reviewing above results it was concluded that lamprey oil and corn oil in polyunsaturated fatty acids had the preventive effect on atherosclerotic rats induced by cholesterol and vitamin $D_2$. And the effect of lamprey oil in n-3 polyunsaturated fatty acids was higher than that of corn oil rich in n-6 polyunsturated fatty acids.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.544-555
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• 2015

This study aims to derivate of the relationship and rating curve for the flow discharge-total sediment using the measured field data from the main points of small-medium stream reaches in agrarian basin. The total sediment of measured data are obtained by bed load added to suspended load which analyzed using the particle size distribution curve of sieve test and the dry or the filtration method from the collected samples by samplers (DH-48, D-74 and BLH-84, BL-84) at the stream bed and the depth-averaged concentration, respectively. These field data had been collected from August 2012 to September 2014 at the seven measuring stations of the national-local channel reaches of the four study streams in the Nonsan river systems of agrarian basin. As a result, the relationships and the rating curve for the flow discharge-total sediment are derived as a function pattern of power law by analyzing on a distribution characteristic of the database set and it will be used as a useful tool to analyze erosion, deposition, and transportation in theoretical research as well as in practical application of the hydraulic sedimentation engineering.

• Preventive Nutrition and Food Science
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• v.1 no.2
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• pp.239-243
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• 1996

Three hundred and twenty-four 1 day old chicks were used to determine the effects of fat source and energy to protein ratio on growth performance , carcass composition and the efficiency on nutrient utilization. Chicks were assigned. in a completely randomized design, to 3*3 factorial arrangement of treatments. Chicks received one of three fat sources (n0 fat, tallow, corn oil) and one of three energy to protein ratios(16, 14 and 12kcal ME/g CP). All diets were formulated to be isocaloric(3.2Mcal ME/kg diets) using published ME values for the diet ingredients. Addition of tat to the diet increased ADG, average daily feed intake, and gain to feed, Chicks fed diets containing fat had increased percentage body DM and ether extract(EE), but percentage CP was not different, Chicks fed diets containing fat had increased efficiency of protein and energy deposition. Addition of fat ad either fallow or corn oil yielded similar results. Reducing the energy to protein ratio of the diet did not affect ADG or gain to feed, but tended to decrease average daily feed intake(p=0.80), as well as resulting in linear(p<0.05) reductions in body percentage DM., EE and also total EE. Increasing the energy to protein ratio did not affect percentage or total body Cp. Adding fat to poultry diets improved growth performance and the efficiency of growth chicks. Decreasing the energy to protein ratio did not affect growth performance, but reduced EE in the body of Chicks.

• Analytical Science and Technology
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• v.30 no.3
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• pp.146-153
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• 2017

In this study, we isolated ginseng crude saponin (GCS) from Korean red ginseng (KRG) and determined the ginsenoside content in it to investigate the physiological and pathological effects of GCS on acute pulmonary inflammation induced by intratracheal instillation of cigarette smoke condensates (CSC) and lipopolysaccharide (LPS) solution in BALB/c mice. GCS was orally administered at doses of 10 mg/kg and 25 mg/kg for 3 weeks. The recovery rate of GCS from KRG was 6.5 % and total ginsenosides from GCS was 1.13 %, and the content of Rb1 was the highest among them. Total inflammatory cells in the lung homogenates and bronchoalveolar lavage fluid (BALF) increased following intratracheal administration of CSC and LPS. However, GCS administration impaired this increase. Furthermore, it inhibited the increase in leukocytes in the blood, considerably decreased neutrophils in BALF, and declined infiltration of inflammatory cells and deposition of collagen in the tracheal and alveolar tissue. In this study, GCS was found to have a protective effect against acute pulmonary inflammation and it may be beneficial in preventing various respiratory diseases.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.272.2-272.2
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• 2016

Copper-Tin (CuSn) thin films were synthsized by rf magnetron co-sputtering method with pure Cu and Sn metal targets with various rf powers and sputtering times. The obtained CuSn thin films were characterized by a surface profiler (alpha step), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray induced Auger electron spectroscopy (XAES), and contact angle measurement. The deposition rates were calculated by the thickness of CuSn thin films and sputtering times. We observed hexagonal Cu20Sn6 and cubic Cu39Sn11 phases from the films by XRD measurement. From the survey XPS spectra, the Cu and Sn main peaks were observed. Therefore, we could conclude CuSn thin films were successfully fabricated on the substrate in this study. The changes of oxidation states and chemical environment of the films were investigated with high resolution XPS spectra in the regions of Cu 2p, Cu LMM, and Sn 3d. Surface free energy (SFE) and wettability of the CuSn thin films were studied with distilled water (DW) and ethylene glycol (EG) using the contact angle measurement. The total SFE of CuSn thin films decreased as rf power on Cu target increased. The contribution to the total SFE of dispersive SFE was relatively superior to polar SFE.