• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.11
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• pp.1379-1389
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• 1999

A new technique for control of size and shape of flame-made particles is Introduced. The characteristic sintering time can be controlled Independently of collision time by heating the particles with irradiation of laser because the sintering time strongly depends on temperature. A coflow oxy-hydrogen diffusion flame burner was used for $SiCl_4$ conversion to silica particle. Nanometer sized aggregates irradiated by a high power CW $CO_2$ laser beam were rapidly heated up to high temperatures and then were sintered to approach volume-equivalent spheres. The sphere collides much slower than the aggregate, which results in reduction of sizes of particles maintaining spherical shape. Light scattering of Ar ion laser and TEM observation using a local sampling device were used to confirm the above effects. When the $CO_2$ laser was irradiated at low position from the burner surface, particle generation due to gas absorption of laser beam occurred and thus scattering intensity increased with $CO_2$ laser power. At high irradiation position, scattering intensity decreased with $CO_2$ laser power and TEM image showed a clear mark of evaporation and recondensation of particles for high $CO_2$ laser power. When the laser was irradiated between the above two positions where small aggregates exist, average size of spherical particles obviously decreased to 58% of those without $CO_2$ laser irradiation with the spherical shape. Even for increased carrier gas flow rate by a factor of three, TEM photograph also revealed considerable reduction of particle size.

• Journal of Broadcast Engineering
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• v.14 no.4
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• pp.409-418
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• 2009

This paper proposes a method to estimate the flow speed of pedestrians in surveillance videos. In the proposed method, the average moving speed of pedestrians is measured by estimating the size of real-world motion from the observed motion vectors. For this purpose, a pixel-to-meter conversion factor is introduced which is calculated from camera parameters. Also, the height information, which is missing because of camera projection, is predicted statistically from simulation experiments. Compared to the previous works for flow speed estimation, our method can be applied to various camera views because it separates scene parameters explicitly. Experiments are performed on both simulation image sequences and real video. In the experiments on simulation videos, the proposed method estimated the flow speed with average error of about 0.08m/s. The proposed method also showed promising results for the real video.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.157-158
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• 2013

Organic solar cell was fabricated using one-pot deposition of a mixture of NiO nanoparticles, P3HT and PCBM. In the presence of NiO, the photovoltaic performance was slightly increased comparing to that of the device without NiO. When $TiO_2$ thin films with a thickness of 2~3 nm was prepared on NiO nanoparticles using atomic layer deposition, the power conversion efficiency was increased by a factor 2.5 with respect to that with bare NiO. Moreover, breakdown voltage of the film consisting of NiO, P3HT, and PCBM on indium tin oxide was increased by more than 1 V in the presence of $TiO_2$-shell on NiO nanoparticles. It is evidenced that S atoms of P3HT can be oxidized on NiO surfaces, and $TiO_2$-shell on NiO nanoparticles. It is evidenced that S atoms of P3HT can be oxidzed on NiO surfaces, and $TiO_2$ shell heavily reduced oxidation of S at oxide/P3HT interfaces. Oxidized S atoms can most likely act as carrier generation sites and recombination centers within the depletion region, decreasing breakdown voltage and performance of organic solar cells. Our result shows that fabrication of various core-shell nanostruecutres of oxides by atomic layer deposition with controlled film thickness can be of potential importance for fabricating highly efficient organic solar cells.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.1882-1893
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• 2019

β-Glucosidases and β-xylosidases are two categories of enzymes that could cleave out non-reducing, terminal β-D-glucosyl and β-D-xylosyl residues with release of D-glucose and D-xylose, respectively. In this paper, two functional β-glucosidase Dth3 and β-xylosidase Xln-DT from Dictyoglomus thermophilum were heterologously expressed in E.coli BL21 (DE3). Dth3 and Xln-DT were relatively stable at 75℃ and were tolerant or even stimulated by glucose and xylose. Dth3 was highly tolerant to glucose with a K_i value of approximately 3 M. Meanwhile, it was not affected by xylose in high concentration. The activity of Xln-DT was stimulated 2.13-fold by 1 M glucose and 1.29-fold by 0.3 M xylose, respectively. Furthermore, the βglucosidase Dth3 and β-xylosidase Xln-DT showed excellent selectivity to cleave the outer C-6 and C-3 sugar moieties of ASI, which established an effective and green method to produce the more pharmacologically active CAG, an exclusive telomerase activator. We measured temperature, pH and dosage of enzyme using a single-factor experiment in ASI biotransformation. After optimization, the optimal reaction conditions were as follows: 75℃, pH 5.5, 1 U of Dth3 and 0.2 U of Xln-DT, respectively. Under the optimized conditions, 1 g/l ASI was transformed into 0.63 g/l CAG with a corresponding molar conversion of 94.5% within 3 h. This is the first report to use the purified thermostable and sugar-tolerant enzymes from Dictyoglomus thermophilum to hydrolyze ASI synergistically, which provides a specific, environment-friendly and cost-effective way to produce CAG.

• The Korean Journal of Pain
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• v.21 no.3
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• pp.206-210
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• 2008

Background: Although the cause of hyperhidrosis has not been the subject of close investigation, there are cases for which excessive sweating happens at the hands, feet and armpits due to hyperactivity of the sympathetic nervous system. This usually occurs in people less than 25 years old and it often causes difficulties for their social and occupational life and there is a decrease in the quality of life. Therefore, this should also be examined according to the mental state of the patient who suffers from hyperhidrosis. Methods: The Minnesota Multiple Personality Inventory was administered to 59 patients in the Hyperhidrosis Center from March, 2006 to March, 2007. The MMPI's validity and 10 clinic standards were analyzed. The results were compared according to gender and age. Results: Of the standard clinical items, psychopathy and conversion hysteria were 21.1% and 17.5%, respectively. On comparison between males (47.5%) and females (52.5%), the females had a higher score for the hypochondriasis item. The patients above 18 years old had a significantly higher level of hypochondriasis and hypomania compared to the patients below 18 years old. Conclusions: When analyzing the personality of the patients with essential hyperhidrosis with using the MMPI, it was difficult to look for relations with the mental factor. Therefore, it is necessary to develop diagnostic tests for younger people with considering the relations with the period of morbidity.

• Current Photovoltaic Research
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• v.3 no.2
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• pp.39-44
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• 2015

$Cu(In,Ga)_3Se_5$ (${\beta}-CIGS$) has a band gap of 1.35 eV which is an optimum value for high solar-energy conversion efficiency. However, ${\beta}-CIGS$ film was not well characterized yet due to lower efficiency compared to $Cu(In,Ga)Se_2$ (${\alpha}-CIGS$). In this work, ${\beta}-CIGS$ films were fabricated by a three-stage co-evaporation of elemental sources with various Se fluxes. As the Se flux increased, the crystallinity of ${\beta}-CIGS$ phase was improved from the analysis of Raman spectroscopy and a deep-level defect was reduced from the analysis of photoluminescence spectroscopy. A Se treatment of the ${\beta}-CIGS$ film at $200^{\circ}C$ increased Ga content and decreased Cu content at the surface of the film. With the Se treatment at $200^{\circ}C$, the cell efficiency was greatly improved for the CIGS films prepared with low Se flux due to the increase of short-circuit current and fill factor. It was found that the main reason of performance improvement was lower Cu content at the surface instead of higher Ga content.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1473-1478
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• 2008

An experiment was conducted to investigate the mechanism for the effect of tetrabasic zinc chloride (TBZC) in enhancing growth performance of weanling piglets. Gut-brain peptides play an important role in the regulation of growth and appetite in animals. This study evaluated the effects of TBZC on blood concentrations of growth hormone (GH), ghrelin, insulin-like growth factor-I (IGF-I), cholecystokinin (CCK) and neuropeptide Y (NPY). Seventy-two weanling piglets (Landrace$\times$Large White) with an initial body weight (BW) of $6.7{\pm}0.16kg$ and aged $24{\pm}1days$ were assigned to three dietary treatments: i) control diet without TBZC supplement, ii) the control diet supplemented with 2,000 mg Zn from TBZC/kg and iii) TBZC-supplemented diet pair-fed with respect to the control diet. Each treatment had six replications (pens) of four piglets. At the end of a 14-d experimental period, piglets were weighed and feed consumption was measured, and blood samples were collected for assays of GH, ghrelin, IGF-I, CCK and NPY concentrations. The inclusion of TBZC in the diet increased average daily gain (p<0.01), average daily feed intake (p<0.05), and feed conversion ratio (p<0.05). Pair-fed piglets had higher ADG, and lower FCR than (p<0.05) Control piglets. Supplementation of the diet with TBZC increased (p<0.05) serum GH and plasma ghrelin levels in weanling piglets, but did not affect (p>0.05) serum IGF-I and plasma NPY and CCK concentrations. Pair-fed piglets had lower (p<0.05) serum GH levels than TBZC-supplemented piglets, but did not (p>0.05) differ from Control piglets. These data indicated that TBZC elevated the concentration of ghrelin and GH. This observation may partly explain the beneficial effects of TBZC on growth performance of weanling piglets.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1115-1119
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• 2007

This study was conducted to determine the difference between satellite cells (porcine) and myoblasts (C2C12) in their differentiation under the influence of 2, 4-thiazolidindion. C2C12 myoblast cells and porcine satellite cells (isolated from 10 d old $Landrace{\times}Duroc$ piglets) were grown to absolute confluency. Post confluent cells (day 0) were further exposed to adipogenic induction medium along with 2, 4-thiazolidindion ($8{\mu}M$) for 2 d. Thereafter, cells were exposed to 2, 4-thiazolidindion alone every 2 d till day 10 and analysed. The control was cultured in differentiation medium without any treatment. Increased (p<0.05) expression of transcriptional factors i.e. C/EBP-${\alpha}$ and PPAR-${\gamma}$ and transition of cells to adipocyte morphology was noticed from 2 d and 4 d onwards in satellite cells (Porcine) and myoblasts (C2C12) respectively. Myogenesis was observed to be suppressed completely in case of satellite cells compared to myoblasts in response to 2, 4-thiazolidindion. Pax-7 (transcriptional factor) appeared as a sole entity to satellite cells only, as it was not identified in case of myoblasts. Although both the cells were converting to adipoblasts, the degree of their conversion was different in response to 2, 4-thiazolidindion. Therefore, the hypothesis that satellite cells contribute various domains to the growing myoblasts appeared obscured and found to be dependent on the proliferative energy/or degree of fusion. However, it revealed satellite cells as currency to myoblasts/muscle.

• Journal of Nutrition and Health
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• v.29 no.3
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• pp.260-266
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• 1996

Eighteen crossbred pigs were weaned at 4 days of age and fed up to 28 days of age to examine the effect of sulfur amino acid content of three diets upon plasma taurine concentration and hepatic cysteinesulfinate decarboxylase activity. The experimental diets consisted of either whey protein (W) or partialy hydrolyzed soy protein (S) as the source of protein. 0.25% methionine was added to the S diet for the third dietary regimen (SM). Sulfur amino acid content(methionine plus cystine)of the three diets was 1.53%, 1.34% and 1.09% for the W, SM and S diet, respectively. Plasma taurine concentration from the pigs fed the three experimental diets reflected the total sulfur amino acid content of the diet. The S diet resulted in a significantly lower plasma tarrine level than the W and SM diets throughout the experiment. After three weeks, pigs fed the W diet had significantly higher plasma taurine concentration than those fed SM diet. Therfore it appears that taurine requirement of the pig depends on the sulfur amino acid contents of the diets and the conversion o sulfur amino acid to taurine seemed not to be limited by any factor when sulfur amino acid was below 1.53% of the diet. There was no significant difference between three dietary groups in hepatic cysteinesulfinate decarboxylase activity and this suggests that the reduced cysteinesulfinate decarboxylase activity due to high sulfur amino acid in the diet may not occur in the pig liver.

• Journal of Microbiology and Biotechnology
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• v.25 no.7
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• pp.1108-1113
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• 2015

Cadaverine (1,5-diaminopentane) is an important industrial chemical with a wide range of applications. Although there have been many efforts to produce cadaverine through fermentation, there are not many reports of the direct cadaverine production from lysine using biotransformation. Whole-cell reactions were examined using a recombinant Escherichia coli strain overexpressing the E. coli MG1655 cadA gene, and various parameters were investigated for the whole-cell bioconversion of lysine to cadaverine. A high concentration of lysine resulted in the synthesis of pyridoxal-5'-phosphate (PLP) and it was found to be a critical control factor for the biotransformation of lysine to cadaverine. When 0.025 mM PLP and 1.75 M lysine in 500 mM sodium acetate buffer (pH6) were used, consumption of 91% lysine and conversion of about 80% lysine to cadaverine were successfully achieved.