• Title/Summary/Keyword: R-410A

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Study on Colour Development in Silver Containing Glass (은을 이용한 착색유리 제조에 관한 연구)

  • 이종근
    • Journal of the Korean Ceramic Society
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    • v.11 no.2
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    • pp.3-10
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    • 1974
  • For the manufacture of the silver-yellow glass, silver nitrate was used as a colorant in the base glass of $K_2O$-CaO-$SiO_2$ system. The latter in which the optimum condition was revealed showing beautiful yellow color had been selected among others after the preparatory studies to choose base glass. Other base glass systems considered were $Na_2O$-CaO-$SiO_2$, $R_2O$-PbO-$SiO_2$ and $R_2O$-PbO-BaO-$SiO_2$. The color developed on the specimen in various conditions was examined, using spectorphotometer, in term of the changes in absorbance with wavelength in the visible range. Experimental variables were the amount of the colorant and the additives, reheating temperature and time. The additives such as ZnO, BaO, $B_2O_3$ and $As_2O_3$ were added to increase the coloring action. It was observed that as the amount of silver increased in the base glass the absorbance around $410{\mu}m$ showed the increasing tendency, but the width of absorption curve was wider. Hence, the optimum amount of silver appeared to be 0.11~0.12%. It was found that ZnO was effective additive when present about 0.1%, while $As_2O_3$ ineffective rather retarding the coloration. Borax and $BaCO_3$ were proved effective when contained separately, but appeared ineffective when coexisted. Proper reheating temperature and time was ranged 550~$580^{\circ}C$ and 50~60 minutes. The higher the reheating temperature and the longer the reheating time, the absorbance was increased, while the width of absorption curve was wider. The colored glass prepared in the present experimental condition was found to have good water-resistance for the decorative purpose.

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Effect of the Pipe Joint on Structural Performance of a Single-span Greenhouse: A Full-scale Experimental and Numerical Study (파이프 이음부가 단동온실 구조성능에 미치는 영향: 실대형 실험적 및 해석적 연구)

  • Shin, Hyun Ho;Ryu, Hee Ryong;Yu, In Ho;Cho, Myeong Whan;Seo, Tae Cheol;Kim, Seung Yu;Choi, Man Kwon
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.410-418
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    • 2021
  • This study was conducted in 8.2m wide single-span greenhouse to investigate the effect of presence or absence of rafter steel pipe joint and foundation conditions on greenhouse structural performance. Structural performance was evaluated by static loading test using the structural performance evaluation system for single-span greenhouse. The measured displacement was compared with the predicted result by numerical analysis. The displacement of each measurement location showed a significant difference regardless of the conditions of the foundation and presence or absence of rafter steel pipe joint. Compared to the hinge conditions, the difference in structural performance of the greenhouse in the fixed conditions was seen to be relatively large. The difference in structural performance according to presence or absence of rafter steel pipe joints, the lateral stiffness of the joint was 8.1% greater.

Effects of age on changes of body composition through caloric restriction in overweight and obese women (과체중 및 비만여성에서 연령이 열량 제한에 의한 체조성 변화에 미치는 영향)

  • Yim, Jung-Eun;Kim, Young-Seol;Choue, Ryowon
    • Journal of Nutrition and Health
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    • v.46 no.5
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    • pp.410-417
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    • 2013
  • Caloric restriction is recognized as one of the best treatment options for obesity, and is associated with changes in body composition. The purpose of this study was to determine the influence of age in caloric restriction in overweight and obese women. In this caloric restriction study, nutrient intake of 61 women was evaluated using food records written by subjects for three days. Body composition and metabolic risk factors were assessed before and after caloric restriction. Blood levels of lipids, glucose, leptin, and adiponectin were measured. Visceral fat and subcutaneous fat were evaluated using bioimpedance analysis. General linear models (GLM) identified the independent effects of age after co-varying baseline weight and difference of energy intake. Weight, fat mass, visceral fat, subcutaneous fat, and blood pressure showed a significant decrease by caloric restriction of 452 kcal/day. The percent changes in weight, visceral fat, and subcutaneous fat were -4.5%, -12.0%, and -8.2%, respectively, after caloric restriction. The percent changes of weight, visceral fat, and subcutaneous fat showed an independent association with age co-varying baseline weight and difference of energy intake. Decreased change in percent of leptin by caloric restriction also showed an association with age. Changes in body composition and leptin by caloric restriction showed an independent association with age. This may indicate greater difficulty in achievement of change of body composition as well as greater obesity-related metabolic risk with aging. Therefore, caloric restriction considering age should be recommended for effective dietary treatment in overweight or obese women.

Availability of MADLDI-TOF MS for Identification of Gram Positive Bacilli Isolated from Blood Culture

  • Choi, Jin-Un;Kim, Sang-Ha;Hwang, Su-Jeong;Yu, Young-Bin;Kim, Sunghyun;Kim, Young-Kwon
    • Biomedical Science Letters
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    • v.24 no.2
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    • pp.108-115
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    • 2018
  • In the present study, results of the identification of Gram-positive bacilli (GPB) were analyzed by using the MALDI-TOF MS technique to score each 2-year blood culture at a university hospital. In addition, 16S rRNA sequence analyses and MALDI-TOF MS results are compared to targeting strains that had been isolated two or more times within the same patient, to evaluate the usefulness of MALDI-TOF MS in GPB identification. According to the cut-off (${\geq}1.7$) criteria, there were 410 (57.5%) reliable strains and 303 (42.5%) non-identified strains among the GPB identification results of 713 strains, using a microflex MALDI Biotyper (Bruker Daltonik GmbH, Bremen, Germany). The isolation appeared most often in the following order: Corynebacterium striatum, Bacillus cereus, Bacillus subtilis, Paenibacillus urinalis, and Listeria monocytogenes. Nearly three-fourths, 66 out of 89 (74.2%) of the strains for Corynebacterium striatum; 44 out of 60 (73.3%) strains for Bacillus cereus; and all (25 out of 25, 100%) Listeria monocytogenes strains were identified by their high scores of 2.0 or higher. Most (293 strains out of 303) non-identified strains were strains isolated only once and not significant as infectious bacilli. A total of 43 out of 50 (86.0%) strains matched and were able to be identified based on the 16 rRNA sequencing comparison results of strains that were isolated twice or more within the same patient and significant as infection bacilli. Non-matching among 5 out of 7 strains was not identified, even with MALDI-TOF MS. In conclusion, GPB can be identified in blood cultures using MALDI-TOF MS. This can be done accurately with ease, rapidly, and at a low cost. It is also thought to be helpful in GPB diagnosis and treatment.

A Study on the Characteristics of Heating Performance of High-Performance Heat Pump with VI cycle using Re-Heater (재열기를 사용한 고성능 VI 사이클 열펌프의 난방 성능 특성에 관한 연구)

  • Lee, Jin-Kook;Choi, Kwang-Hwan
    • Journal of Power System Engineering
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    • v.19 no.4
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    • pp.69-75
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    • 2015
  • In this study, the characteristics of heating performance of a high-performance air-cooled heat pump with vapor-injection(VI) cycle using re-heater was investigated experimentally. Devices used in the experiment is consist of a VI compressor, condenser, oil separator, refrigerant (economizer outlet refrigerant) re-heater, economizer, evaporator. And R410A was used as a working fluid. The experiment was conducted with two cycles(cycles A and B) for investigating heating performance. In case of cycle B, heat exchange was conducted by re-heater between outlet refrigerant of compressor and suction refrigerant of the VI system(Fig.1, re-heater). But the re-heater was not used in case of cycle A. As a result of this experiment, discharge temperature of refrigerator in compressor was shown higher value, when the cycle B was conducted, because of the heat exchange between suction refrigerant of VI cycle and outlet refrigerant of compressor in the re-heater than cycle A that was not use re-heater. it means that liquid hammer and the decrement of heating performance can be decreased by using re-heater. Also, Heating coefficient of performance(COPh) was shown about 2.98 in Cycle B which was 4% higher than Cycle A and from these results, It was confirmed that the improvement of the heating performance of heat pump with VI cycle can be achieved by applying re-heater.

Heating Performance Characteristics of Heat Pump with VI cycle using Re-Heater and Solar-Assisted (태양열과 재열기를 사용한 VI heat pump의 성능 특성에 관한 연구)

  • Lee, Jin-Kook;Choi, Kwang-Hwan
    • Journal of the Korean Solar Energy Society
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    • v.35 no.6
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    • pp.25-33
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    • 2015
  • In this study, heating performance of the air-cooled heat pump with vapor-injection (VI) cycles, re-heater and solar heat storage tank was investigated experimentally. Devices used in the experiment were comprised of a VI compressor, re-heater, economizer, variable evaporator, flat-plate solar collector for hot water, thermal storage tank, etc. As working fluid, refrigerant R410A for heat pump and propylene glycol (PG) for solar collector were used. In this experiment, heating performance was compared by three cycles, A, B and C. In case of Cycle B, heat exchange was conducted between VI suction refrigerant and inlet refrigerant of condenser by re-heater (Re-heater in Fig. 3, No. 3) (Cycle B), and Cycle A was not use re-heater on the same operating conditions. In case of Cycle C, outlet refrigerant from evaporator go to thermal storage tank for getting a thermal energy from solar thermal storage tank while re-heater also used. As a result, Cycle C reached the target temperature of water in a shorter time than Cycle B and Cycle A. In addition, it was founded that, as for the coefficient of heating performance($COP_h$), the performance in Cycle C was improved by 13.6% higher than the performance of Cycle B shown the average $COP_h$ of 3.0 and by 18.9% higher than the performance of Cycle A shown the average $COP_h$ of 2.86. From this results, It was confirmed that the performance of heat pump system with refrigerant re-heater and VI cycle can be improved by applying solar thermal energy as an auxiliary heat source.

A Study on Estimating Real-time Thermal Load During GHP Operation in Heating Mode (GHP 난방 모드 운전시 실시간 부하 추정방법에 관한 연구)

  • Seo, Jeong-A;Shin, Young-Gy;Oh, Se-Je;Jeong, Sang-Duck;Ji, Kyoung-Chul;Jeong, Jin-Hee
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.1
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    • pp.32-37
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    • 2011
  • The present study has been conducted to propose an algorithm regarding real-time load estimation of a gas engine-driven heat pump. In the study, thermal load of an indoor unit is estimated in terms of air-side and refrigerant-side. The air-side estimation is based on a typical heat exchanger model and is found to be in good agreement with experimental data. When it comes to the refrigerant-side load, a pressure difference across a valve must be estimated. For the estimation, it is assumed to be proportional to a bigger pressure difference that is available either by measurement or by estimation. Relative good agreement between the air- and refrigerant-sides suggests that the assumption may be plausible for the load estimation. The summed flow rate of all of indoor units is in good agreement with the throughput of the compressor which are calculated from the manufacturer's software. Accordingly, estimated thermal loads are also in good agreement. The proposed algorithm may be further developed for improved control algorithm and fault diagnosis.

Genetic Variation and Species Identification of Thai Boesenbergia (Zingiberaceae) Analyzed by Chloroplast DNA Polymorphism

  • Techaprasan, Jiranan;Ngamriabsakul, Chatchai;Klinbunga, Sirawut;Chusacultanachai, Sudsanguan;Jenjittikul, Thaya
    • BMB Reports
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    • v.39 no.4
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    • pp.361-370
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    • 2006
  • Genetic variation and molecular phylogeny of 22 taxa representing 14 extant species and 3 unidentified taxa of Boesenbergia in Thailand and four outgroup species (Cornukaempferia aurantiflora, Hedychium biflorum, Kaempferia parviflora, and Scaphochlamys rubescens) were examined by sequencing of 3 chloroplast (cp) DNA regions (matK, psbA-trnH and petA-psbJ). Low interspecific genetic divergence (0.25-1.74%) were observed in these investigated taxa. The 50% majority-rule consensus tree constructed from combined chloroplast DNA sequences allocated Boesenbergia in this study into 3 different groups. Using psbA-1F/psbA-3R primers, an insertion of 491 bp was observed in B. petiolata. Restriction analysis of the amplicon (380-410 bp) from the remaining species with Rsa I further differentiated Boesenbergia to 2 groupings; I (B. basispicata, B. longiflora, B. longipes, B. plicata, B. pulcherrima, B. tenuispicata, B. thorelii, B. xiphostachya, Boesenbergia sp.1 and Boesenbergia sp.3; phylogenetic clade A) that possesses a Rsa I restriction site and II (B. curtisii, B. regalis, B. rotunda and Boesenbergia sp.2; phylogenetic clade B and B. siamensis; phylogenetic clade C) that lacks a restriction site of Rsa I. Single nucleotide polymorphism (SNP) and indels found can be unambiguously applied to authenticate specie-origin of all investigated samples and revealed that Boesenbergia sp.1, Boesenbergia sp.2 and B. pulcherrima (Mahidol University, Kanchanaburi), B. cf. pulcherrima1 (Prachuap Khiri Khan) and B. cf. pulcherrima2 (Thong Pha Phum, Kanchanaburi) are B. plicata, B. rotunda and B. pulcherrima, respectively. In addition, molecular data also suggested that Boesenbergia sp.3 should be further differentiated from B. longiflora and regarded as a newly unidentified Boesenbergia species.

Effects of Biofertilizer Rate and Application Time on Growth Characters and Grain Quality of Rice

  • Mintah, Lemuel Ohemeng;Rico, Cyren Mendoza;Shin, Dong-Il;Chung, Il-Kyung;Son, Tae-Kwon;Lee, Sang-Chul
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.52 no.4
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    • pp.403-410
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    • 2007
  • A field experiment was conducted to investigate effects of application time and rate of biofertilizer alone and in combination with chemical NPK fertilizer on growth, yield and quality of rice. The biofertilizer used composted food waste as substrate and added with effective microorganism. The treatments included recommended NPK fertilizer(RF, $11-5.5-4.8kg\;10a^{-1}$), half recommended NPK fertilizer(HRF, $5.5-2.8-2.4kg\;10a^{-1}$), half recommended NPK fertilizer plus $250kg\;10a^{-1}$ biofertilizer(HRF+Bio 250) and $500kg\;10a^{-1}$ biofertilizer(HRF+Bio 500). The biofertilizer treatments were applied at 0, 5 and 10 days before transplanting(DBT). Grain yield of HRF+Bio 250 at 5 DBT($648.4kg\;10a^{-1}$) was statistically similar to the highest obtained in the RF($654.1kg\;10a^{-1}$). Tiller numbers at HRF plus biofertilizer treatments were already high during the maximum tillering stage, and were similar with that of the RF and higher than that of the HRF during heading stage. Likewise, ripening ratio at HRF plus biofertilizer treatments was similar with that of the RF and higher than that of the HRF. Furthermore, all the biofertilizer treatments improved protein content but reduced the amylose content and palatability compared to treatments with chemical NPK fertilizer alone. Thus, HRF+Bio 250 at 5 DBT can be used to save 50% chemical NPK fertilizer and at the same time obtain an improved rice grain yield and quality.

Comparison of the oral microbial composition between healthy individuals and periodontitis patients in different oral sampling sites using 16S metagenome profiling

  • Kim, Yeon-Tae;Jeong, Jinuk;Mun, Seyoung;Yun, Kyeongeui;Han, Kyudong;Jeong, Seong-Nyum
    • Journal of Periodontal and Implant Science
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    • v.52 no.5
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    • pp.394-410
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    • 2022
  • Purpose: The purpose of this study was to compare the microbial composition of 3 types of oral samples through 16S metagenomic sequencing to determine how to resolve some sampling issues that occur during the collection of sub-gingival plaque samples. Methods: In total, 20 subjects were recruited. In both the healthy and periodontitis groups, samples of saliva and supra-gingival plaque were collected. Additionally, in the periodontitis group, sub-gingival plaque samples were collected from the deepest periodontal pocket. After DNA extraction from each sample, polymerase chain reaction amplification was performed on the V3-V4 hypervariable region on the 16S rRNA gene, followed by metagenomic sequencing and a bioinformatics analysis. Results: When comparing the healthy and periodontitis groups in terms of alpha-diversity, the saliva samples demonstrated much more substantial differences in bacterial diversity than the supra-gingival plaque samples. Moreover, in a comparison between the samples in the case group, the diversity score of the saliva samples was higher than that of the supra-gingival plaque samples, and it was similar to that of the sub-gingival plaque samples. In the beta-diversity analysis, the sub-gingival plaque samples exhibited a clustering pattern similar to that of the periodontitis group. Bacterial relative abundance analysis at the species level indicated lower relative frequencies of bacteria in the healthy group than in the periodontitis group. A statistically significant difference in frequency was observed in the saliva samples for specific pathogenic species (Porphyromonas gingivalis, Treponema denticola, and Prevotella intermedia). The saliva samples exhibited a similar relative richness of bacterial communities to that of sub-gingival plaque samples. Conclusions: In this 16S oral microbiome study, we confirmed that saliva samples had a microbial composition that was more similar to that of sub-gingival plaque samples than to that of supra-gingival plaque samples within the periodontitis group.