• 대한기계학회논문집B
• /
• 제25권12호
• /
• pp.1831-1843
• /
• 2001

In this study, convective boiling tests were conducted for enhanced tube bundles. The surface geometry consists of pores and connecting gaps. Tubes with three different pore sizes (d$_{p}$ = 0.20, 0.23 and 0.27 mm) were tested using R-123 and R-l34a for the following range: 8 kg/m$^2$s G 26 kg/m$^2$s, 10 kW/m$^2$ q0 40 kW/m$^2$and 0.1 $\chi$ 0.9. The convective boiling heat transfer coefficients were strongly dependent on heat flux with negligible dependency on mass flux or quality. For the present enhanced geometry (pores and gaps), the convective effect was apparent. The gaps of the present tubes may have served routes for the passage of two-phase mixtures, and enhanced the boiling heat transfer. The convective effect was more pronounced at a higher saturation temperature. More bubbles will be generated at a higher saturation temperature, which will lead to enhanced convective contribution. The pore size where the maximum heat transfer coefficient was obtained was larger for R-l34a (d$_{p}$ = 0.27 mm) compared with that for R-123 (d$_{p}$ = 0.23 mm). This trend was consistent with the previous pool boiling results. For the enhanced tube bundles, the convective effect was more pronounced for R-134a than for R-123. This trend was reversed for the smooth tube bundle. Possible reasoning is provided based on the bubble behavior on the tube wall. Both the modified Chen and the asymptotic model predicted the present data reasonably well. The RMSEs were 14.3% for the modified Chen model and 12.7% for the asymptotic model.model.

• Plant Biotechnology Reports
• /
• 제4권1호
• /
• pp.85-94
• /
• 2010

In vitro shoot regeneration of gladiolus in three different culture systems, viz., semi-solid agar (AS), membrane raft (MR), and duroplast foam liquid (DF) cultures was evaluated following the kinetics of shoot multiplication and hyperhydricity at optimized growth regulator combinations. Compared to the AS system, matrixsupported liquid cultures enhanced shoot multiplication. The peak of shoot multiplication rate was attained at 18 days of incubation in the MR and DF systems, whereas the maximum rate in the AS system was attained at 21 days. An early decline in acceleration trend was observed in liquid cultures than the AS culture. The hyperhydric status of the regenerated shoots in the different culture systems was assessed in terms of stomatal attributes and antioxidative status. Stomatal behavior appeared to be normal in the AS and MR systems. However, structural anomaly of stomata such as large, round shaped guard cells with damage in bordering regions of stomatal pores was pronounced in the DF system along with a relatively higher $K^+$ ion concentration than in the AS and MR systems. Antioxidative status of regenerated shoots was comparable in the AS and MR systems, while a higher incidence of oxidative damages of lipid membrane as evidenced from malondialdehyde and ascorbate content was observed in the DF system. Higher oxidative stress in the DF system was also apparent by elevated activities of superoxide dismutase, ascorbate peroxidase, and catalase. Among the three culture systems, liquid culture with MR resulted in maximum shoot multiplication with little or no symptoms of hyperhydricity. Shoots in the DF system were more prone to hyperhydricity than those in the AS and MR systems. The use of matrix support such as membrane raft as an interface between liquid medium and propagating tissue could be an effective means for rapid and efficient mass propagation with little or no symptoms of hyperhydricity.

• 한국물환경학회지
• /
• 제20권5호
• /
• pp.415-421
• /
• 2004

Litter wastes on highway runoff are gradually being considered one of the major pollutants of concern in protecting the integrity of receiving waters for beneficial use. The California State Water Resources Control Board has identified in their 303(d) list at least 36 water bodies where trash or litter is considered a pollutant of concern. The first TMDL adopted by the Region 4 (Los Angeles area) of the California State Water Quality Control Board was for trash in the Los Angeles River. The first flush characteristic study was developed to obtain first flush water quality and litter data from representative stormwater runoff from standard highway drainage outfalls in the Los Angeles area. Total captured gross pollutants in stormwater runoff were monitored at six Southern California highway sites over two years. The gross pollutants were 90% vegetation and 10% litter. Approximately 50% of the litter was composed of biodegradable materials. The event mean concentrations show an increasing trend with antecedent dry days and a decreasing trend with total runoff volume or total rainfall. Event mean concentrations were ranged 0.0021 to 0.259g/L for wet gross pollutants and 0.0001 to 0.027g/L for wet litters. The first flush phenomenon was evaluated and the impacts of various parameters such as rainfall intensity, drainage area, peak flow rate, and antecedent dry period on litter volume and loading rates were evaluated. First flush phenomenon was generally observed for litter concentrations, but was not apparent with litter mass loading rates. Litter volume and loading rates appear to be directly related to peak storm intensity, antecedent dry days and total flow volume.

• 한국어병학회지
• /
• 제3권1호
• /
• pp.11-19
• /
• 1990

방어의 유결절증(類結節症) 신속진단(迅速診斷)을 위(爲)한 면역형광항체법(免疫螢光抗體法)의 유용성(有用性)을 검토(檢討)하기 위하여 원인균(原因菌)으로 면역(免疫)된 항혈청(抗血淸)에서 면역(免疫)글로브린 G(IgG)를 분리(分離)하여 FITC표식(標識) 항체(抗體)를 정제(精製)하였다. 정제(精製)된 표식항체(標識抗體)는 형광강도(螢光强度)가 1 : 32였으며 이 표식항체(標識抗體)를 이용(利用)하여 1990년(年) 7월(月)부터 10월(月)까지 경남(慶南) 통영군(統營郡) 소재(所在) 방어 양식장(養殖場)을 대상(對象)으로 유결절증진단시험(類結節症診斷試驗)을 실시(實施)한 결과(結果) 직접형광항체법(直接螢光抗體法)으로 2시간내(時間內)에 원인균(原因菌)의 신속진단(迅速診斷)이 가능(可能)하고 균검출면(菌檢出面)에서도 평판도말(平板塗抹) 배양법(培養法)보다 효과적(效科的)인 것으로 나타났다.

• Journal of Microbiology and Biotechnology
• /
• 제15권2호
• /
• pp.239-246
• /
• 2005

Some characteristics of two forms of glucoamylase (glucan 1 A-$\alpha$-glucosidase, EC 3. 2. I. 3) purified from Aspergillus coreanus NR 15-1 were investigated. The enzymes were produced on a solid, uncooked wheat bran medium of A. coreanus NR 15-1 isolated from traditional Korean Nuruk. Two forms of glucoamylase, GA-I and GA-II, were purified to homogenity after 5.8-fold and 9.6-fold purification, respectively, judged by disc- and SDS-polyacrylamide gel electrophoresis. The molecular mass of GA-I and GA-II were estimated to be 62 kDa and 90 kDa by Sephadex G-1OO gel filtration, and 64 kDa and 91 kDa by SDS-polyacrylarnide gel electrophoresis, respectively. The optimum temperatures of GA-I and GA-II were 60$^circ$C and 65$^circ$C, respectively, and the optimum pH was 4.0. The activation energy (Ea value) of GA-I and GA-II was 11.66 kcal/mol and 12.09 kcal/mol, respectively, and the apparent Michaelis constants (K_{m}) of GA-I and GA-II for soluble starch were found to be 3.57 mg/ml and 6.25 mg/ml, respectively. Both enzymes were activated by 1 mM Mn^{2+} and Cu^{2+}, but were completely inhibited by 1 mM N­bromosuccinimide. The GA-II was weakly inhibited by 1 mM p-CMB, dithiothreitol, EDTA, and pyridoxal 5-phosphate, but GA-I was not inhibited by those compounds. Both enzymes had significant ability to digest raw wheat starch and raw rice starch, and hydrolysis rates of raw wheat starch by GA-I and GA-II were 7.8- and 7.3-fold higher than with soluble starch, respectively.

• Journal of Microbiology and Biotechnology
• /
• 제15권2호
• /
• pp.302-309
• /
• 2005

Phytopathogenic Pectobacterium carotovorum subsp. carotovorum (Pcc) LY34 secretes multiple isozymes of the plant cell wall degrading enzyme endoglucanases. We have cloned a third cel gene encoding CMCase from Pcc LY34. The structural organization of the celC gene (AY188753) consisted of an open reading frame (ORP) of 1,116 bp encoding 371 amino acid residues with a signal peptide of 22 amino acids within the NH$_2$-terminal region of pre-CelC. The predicted amino acid sequence of CelC was similar to that of Peetobaeterium ehrysanthemi Cel8Y (AF282321). The CelC has the conserved region of the glycoside hydrolase family 8. The apparent molecular mass of CelC was calculated to be 39 kDa by CMC-SDS-PAGE. The cellulase­minus mutant of Pee LY34 was as virulent as the wild-type in pathogenicity tests on tubers of potato. The results suggest that the CelC of Pce LY34 is a minor factor for the pathogenesis of soft-rot.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
• /
• pp.53-60
• /
• 2000

Strain BH5 was isolated from naturally fermented Kimchi and identified as a bacteriocin producer, which has bactericidal activity against Micrococcus flavus ATCC 10240. Strain BH5 was identified tentatively as Lactococcus lactis by the API test and some characteristics. Lactococcus lactis BH5 showed a broad spectrum of activity against most of the non-pathogenic and pathogenic microorganisms tested by the modified deferred method. The activity of lacticin BH5, named tentatively as the bacteriocin produced by Lactococcus lactis BH5, was detected at the mid-log growth phase, reached its maximum during the early stationary phase, and decreased after the late stationary phase. Lacticin BH5 also showed a relatively broad spectrum of activity against non-pathogenic and pathogenic microorganisms as tested by the spot-on-lawn method. Its antimicrobial activity on sensitive indicator cells was completely disappeared by protease XIV or ${\alpha}$-chymotrypsin. The inhibitory activities of lacticin BH5 were detected during treatments up to 100$^{\circ}C$ for 30 min. Lacticin BH5 was very stable over a pH range of 2.0 to 9.0 and was stable with all the organic solvents examined. The cell concentration and bacteriocin production in strain BH5 were maximum when grown at 30$^{\circ}C$ in a modified MRS medium supplemented with 0.5% tryptone, 1.0% yeast extract, and 0.5% beef extract as nitrogen sources. It demonstrated a typical bactericidal mode of inhibition against Micrococcus flavus ATCC 10240. Lacticin BH5 was purified through ammonium sulfate precipitation, ethanol precipitation, and CM-Sepharose column chromatography. The apparent molecular mass of lacticin BH5 was estimated to be in the region of 3.7 kDa, by the direct detection of bactericidal activity after SDS-PAGE. Mutant strain NO141 which was isolated by nitrosoguanidine mutagenesis produced about 4 fold more bacteriocin than the wild type.

• 한국식품과학회지
• /
• 제31권2호
• /
• pp.553-557
• /
• 1999

혈전용해능을 가진 균류 (버섯류) 5종 Daedaleopsis styracina, Trichaptum abietium, Coriolus versicolor, Pisolithus tinctorius 그리고 Tricholomopsis decora 등을 선발하여 혈전용해효소 활성을 측정하였고, 기질 특이성을 조사하였다. 버섯 추출액을 조제하여 혈전 용해도를 측정한 결과 plasmin 1.0 unit 보다 $3{\sim}4$배의 높은 활성을 보였으며, 그 중 Pisolithus tinctorius이 가장 높은 활성(4.71 plasmin unit)을 나타내었고, Tricholomopsis decora가 Plasmin에 대한 기질 N-p-Tosyl-Gly-Pro-Lys p-nitroanilide에 대해 가장 높은 특이성(1.32 plasmin unit)을 보였다. 버섯의 균사체로부터 추출한 효소를 SDS-fibrin zymography 활성확인법에 의해 분석한 결과 분자량이 54와 61 kDa의 공통된 활성을 가지는 단백질을 확인하였으며, Trichaptum abietium는 100 kDa의 그리고 Tricholomopsis decora는 84 kDa의 강한 활성을 가지는 혈전용해효소를 확인하였다.

• Mycobiology
• /
• 제45권3호
• /
• pp.178-183
• /
• 2017

Diabetes mellitus is a chronic disorder which affects millions of population worldwide. Global estimates published in 2010 reported the world diabetic prevalence as 6.4%, affecting 285 million adults. Foot ulceration and wound infection are major forms of disabilities arising from diabetic diseases. This study was aimed to develop a natural antimicrobial finishing on medical grade textile that meets American Association of Textiles Chemists and Colorists (AATCC) standard. The textile samples were finished with the ethanolic extract of Penicillium amestolkiae elv609, an endophytic fungus isolated from Orthosiphon stamineus Benth (common name: cat's whiskers). Endophyte is defined as microorganism that reside in the living plant tissue, without causing apparent disease symptom to the host. The antimicrobial efficacy of the ethanolic extract of P. minioluteum was tested on clinical pathogens isolated from diabetic wound. The extract exhibited significant inhibitory activity against 4 bacteria and 1 yeast with the minimal inhibitory concentration ranged from 6.25 to 12.5 mg/mL. The results indicate different susceptibility levels of the test microorganism to the ethanolic extract. However, the killing activity of the extract was concentration-dependent. The finished medical textile showed excellent antimicrobial efficacy on AATCC test assays. All the microbial cultures treated with the textile sample displayed a growth reduction of 99.9% on Hoheinstein Challenge Test. The wash durability of the finished textile was found good even after 50 washes with commercial detergent. Besides, the gas chromatography mass spectrometry analysis showed that 6-octadecenoic acid and diethyl phthalate were the main bioactive constituents of the extract. In conclusion, the developed medical textile showed good antimicrobial efficacy on laboratory tests. This work can be extended to in vivo trials for developing healthcare textile products for antimicrobial applications.

• 대한안전경영과학회지
• /
• 제6권4호
• /
• pp.83-97
• /
• 2004

The growing importance of product quality is becoming more and more daily apparent as we enter the age of globalization around the world. And the product safety is getting more focus as well as product quality. As a result, many domestic companies are putting a lot of emphasis on safety measures and management activities and these companies' products are mainly superior to other companies' product. When we separate the product quality procedure into 3 steps, i.e. quality secure-quality confirm-quality guarantee, of course the 1st step is the most important, but also End step of product quality confirm process is important. And in mass production environment, sampling inspection is more desirable than the 100 % inspection procedure. As a part of globalization trend, KS system is also being revised and reestablished based on ISO, IEC, etc. which are based on international standard. Conventional KS sampling inspection standards were in many areas quite different from ISO sampling standards, only KS A 3102, 3104, 3151 are left and the rest become obsolete, and even the ones that are still around are planned to the gone step by step. It has been already 3 years since the new KS A ISO 2859-0-3 sampling inspection process has been established which the abolition of the popular KS A 3101, KS A 3105, KS A 3109, yet the implementation rate is very slow. This study will attempt to analyze the new KS A ISO 2859-2 and KS A ISO 2859-3, and try to understand the difference as that the new standard can be easily understood and used widely among companies, by using examples. Our attempt is to help implement with the companies with active safety involvement but the final result can be spread among other companies as well in the near future.