• Title/Summary/Keyword: water-resistant

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The Replacement Plans for Aged Public Water Supply Pipes in Apartment Buildings : Especially Apartment Buildings in Bucheon (공동주택의 노후 급수관 개선방안에 관한 연구 : 부천시 공동주택을 중심으로)

  • Lee, Yong-Hwa;Heo, Yong-Chul
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.4
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    • pp.228-232
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    • 2015
  • The water supply galvanized steel pipes of apartment buildings in Bucheon city constructed with building permission before 1994 have many problems such as leaks, the water containing rust, and low water pressure due to corrosion. Therefore, this study aims to find a way to renew the water supply pipes under investigation through a survey. As a result, when replacing the galvanized steel pipe with the corrosion-resistant pipe, the water supply system should also be changed from the gravity tank system to the booster pump system and the hygienic water storage tank. It is necessary to redraft the long-term repair plan including the replacement of the water supply system. Also, it is necessary to save the allowance reserve according to the modified long-term repair plan.

cDNA Microarray Analysis of Phytophthora Resistance Related Genes Isolated from Pepper

  • Kim, Hyounjoung;Lee, Mi-Yeon;Kim, Ukjo;Lee, Sanghyeob;Park, Soon-Ho;Her, Nam-Han;Lee, Jing-Ha;Yang, Seung-Gyun;Harn, Chee-Hark
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.67.1-67
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    • 2003
  • Phytophthora blight is a devastating disease of pepper and occurs almost anywhere peppers are grown. Phytophthora blight is caused by Phytophthora capsici and this pathogen can infect every part of the plant by moving inoculum in the soil, by infecting water on surface, by aerial dispersal to sporulating lesions. Management of Phytophthora blight currently relies on cultural practices, crop rotation, and use of selective fungicides. Since these treatments are a short-term management, a classical breeding for development of resistant pepper against the Phytophthora is an alternative. So far some of the resistant cultivars have been on the market, but those are limited regionally and commercially. Therefore, ultimately an elite line resistant against this disease should be developed, if possible, by biotechnology. We have set out a series of work recently in order to develop Phytophthora resistant pepper cultivar. For the first time, the cDNA microarray analysis was peformed using an EST chip that holds around 5000 pepper EST clones to identify genes responsive to Phytophthora infection. Total RNA samples were obtained from Capsicum annuum PI201234 after inoculating P. capsici to roots and soil and exposed to the chip. .Around 900 EST clones were up-regulated and down-regulated depending on the two RNA sample tissues, leaf and root. From those, we have found 55 transcription factors that may be involved in gene regulation of the disease defense mechanism. Further and in detail information will be provided in the poster.

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Screening of Resistant Watermelon Cultivars Against Gummy Stem Blight Fungus, Didymella bryoniae, and Comparison of Protein Expression Between Cultivars After Infection (수박 덩굴마름병의 품종 저항성 검정과 감염 후 품종간 단백질 발현의 비교)

  • 홍정래;임양주;권미경;조백호;김기청
    • Korean Journal Plant Pathology
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    • v.14 no.4
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    • pp.339-344
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    • 1998
  • Since the leaf inoculation procedures are time-consuming and require considerable growth chamber space, a rapid dioassay method for screening of pathogenicity of Didymella bryoniae, a casual agent of gummy stem blight in watermelon, was established in this paper. The method produced reliable results within 8 days ( 5 days for growing seedlings and 3 days for rapid disease response in the seedlings). After contaminants in the root of 4~5 day-old seedlings had been washed using sterilized water, 5 seedlings were dipped into a vial containing 12 ml of conidial suspension (106 cells/ml). After the vials were placed in a growth chamber (22$^{\circ}C$, RH 50%, 14hr light/10hr darkness) for 3 days, susceptibility and resistance of cultivars were determined by the degree of disease response on cotyledon. The result of obtained by the dip-inoculation method was well coincided with the results by the leaf inoculation procedures and the result that had been observed for several years in the field. Screening of collected watermelon cultivars by the dip-inoculation method revealed that all the 21 domestic cultivars collected were susceptible and only 3 foreign cultivars (PI 189225, PI 482322 and IT 188207) were resistant among 18 cultivars A cucumber cultivar (Marketer) and bitter cucumber were proven to be resistant against the D. bryoniae among 8 other different cucurbits tested. The SDS-PAGE patterns of total proteins from a susceptible (Keumcheon) and a resistant (PI 189225) watermelon cultivars were compared 0, 12, 24 and 36 hrs after inoculation. The amounts of two distinct protein bands (24 kDa and 70 kDa) were gradually increased after inoculation in both cultivars.

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Structure and Diversity of Arsenic-Resistant Bacteria in an Old Tin Mine Area of Thailand

  • Jareonmit, Pechrada;Sajjaphan, Kannika;Sadowsky, Michael J.
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.169-178
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    • 2010
  • The microbial community structure in Thailand soils contaminated with low and high levels of arsenic was determined by denaturing gradient gel electrophoresis. Band pattern analysis indicated that the bacterial community was not significantly different in the two soils. Phylogenetic analysis obtained by excising and sequencing six bands indicated that the soils were dominated by Arthrobacter koreensis and $\beta$-Proteobacteria. Two hundred and sixty-two bacterial isolates were obtained from arsenic-contaminated soils. The majority of the As-resistant isolates were Gramnegative bacteria. MIC studies indicated that all of the tested bacteria had greater resistance to arsenate than arsenite. Some strains were capable of growing in medium containing up to 1,500 mg/l arsenite and arsenate. Correlations analysis of resistance patterns of arsenite resistance indicated that the isolated bacteria could be categorized into 13 groups, with a maximum similarity value of 100%. All strains were also evaluated for resistance to eight antibiotics. The antibiotic resistance patterns divided the strains into 100 unique groups, indicating that the strains were very diverse. Isolates from each antibiotic resistance group were characterized in more detail by using the repetitive extragenic palindromic-PCR (rep-PCR) DNA fingerprinting technique with ERIC primers. The PCR products were analyzed by agarose gel electrophoresis. The genetic relatedness of 100 bacterial fingerprints, determined by using the Pearson product-moment similarity coefficient, showed that the isolates could be divided into four clusters, with similarity values ranging from 5-99%. Although many isolates were genetically diverse, others were clonal in nature. Additionally, the arsenic-resistant isolates were examined for the presence of arsenic resistance (ars) genes by using PCR, and 30% of the isolates were found to carry an arsenate reductase encoded by the arsC gene.

Thirteen-Week Repeated Oral Toxicity Study of Leaf Folder (Cnaphalocrocis medinalis) Resistant Rice (Nakdongbyeb) in Sparague-Dawely Rats (SD 랫드에서 혹명나방 저항성 유전자 변형 낙동벼의 13주 경구 반복투여 독성에 관한 연구)

  • Seo, Dong-Seok;Kwon, Min;Sung, Ha-Jung;Park, Cheol-Beom
    • The Korean Journal of Pesticide Science
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    • v.15 no.2
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    • pp.104-113
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    • 2011
  • We investigated the systemic effects of leaf folder (Cnaphalocrocis medinalis) resistant rice (transgenic rice, Nakdongbyeb) in Sprague-Dawley rats for 13 weeks. Leaf folder resistant rice was added to the diet at percentage levels of 0, 5 and 20 percentage/feeder and was administered for 13 weeks. The results did not show any changes in food and water intake. There were also no biologically significant changes in both body and organ weights, hematological and blood biochemical parameters, autopsy and histopathology between the treatment and control groups. Based on these results, no observed adverse effect level (NOAEL) of transgenic rice was considered to be more than 10,000 mg/kg b.w. under the conditions of the present study.

The Statistical Analysis for the fate of Antibiotic Resistance according to the Spatial and Operational Wastewater Treatment Factors (하수 처리시설의 공간 및 운전인자에 따른 항생제 내성의 통계학적 분석)

  • Kim, Sung-Pyo;Cho, Yun-Chul;Kim, Lee-Hyung;Chandran, Kartik
    • Journal of Wetlands Research
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    • v.13 no.1
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    • pp.117-127
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    • 2011
  • The aim of this study was to examine the fate of tetracycline resistant bacteria (TRB) and tetracycline resistant genes (TRG) according to the spatial and operational wastewater treatment factors. As part of the effort, TRB and TRG of water samples at each unit processes of three different wastewater treatment plants (WWTPs) were analyzed over seven month study periods. With the data about different spatial and operating conditions of these WWTPs, TRB and TRGs, principal component analysis (PCA) was performed to find out any general correlation trend. Based on the statistic analysis results, the extent of TRB concentration in the activated sludge (TRBAS) is much related to the TRB concentration in primary clarifier effluent (TRBPE). Also, the study results indicated that the fate of TRB and TRG are significantly affected by the SRT variations.

Effects of Processing Parameters of Twin Screw Extruder and Dry Methods on the Resistant Starch Formation from Normal Maize Starch (압출성형공정과 건조조건이 옥수수전분의 저항전분 수율에 미치는 영향)

  • Shin, Mal-Shick;Mun, Sae-Hun;Bae, Chun-Ho
    • Korean Journal of Human Ecology
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    • v.5 no.1
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    • pp.62-70
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    • 2002
  • The objective of this study was to evaluate the effects of processing parameters of co-rotating twin screw extruder and dry methods on the level of resistant starch (RS) and the properties of extrudate prepared from normal maize starch. The processing parameters were used 90, 110, 130$^{\circ}C$ in temperature, 25.0~30.0% in moisture content, 150, 200, 250 rpm in screw speed and hot and cool air drying and drying after refrigerating in drying methods. The barrel temperature and drying methods had affected the level of resistant starch of extrudate. RS levels of extrudates were ranged from 2.4 to 15.5% by AOAC method. The extrudates, extruded at 110$^{\circ}C$ and then stored at 4$^{\circ}C$, showed the highest level of RS level (15.5%). Water absorption index increased with increasing moisture content and peak temperatures and viscosities of extudates decreased compare to that of raw starch from 94$^{\circ}C$ to 50~65$^{\circ}C$ and from 220 to 46~98 RVU, respectively. Extudates treated in 90$^{\circ}C$ and 110$^{\circ}C$ showed strong peak at $2{\theta}=6.7{\sim}17.0^{\circ}$ by X-ray diffractometry and had ~150$^{\circ}C$ endotherm like as that of RS3 starch by differential scanning calorimetry. In case of 130$^{\circ}C$, extrudates showed strong peak at $2{\theta}=20.0^{\circ}$ and had 106$^{\circ}C$ endotherm.

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THE MICROLEAKAGE OF LIGHT-CURED GLASS LONOMER RESTORATIVE MATERIALS IN CLASS V CAVITIES (제 5급와동에서 광중합 그래스 아이오노머 수복물의 미세변연누출에 관한 연구)

  • Cho, In-Sik;Park, Joon-Il;Kwon, Hyuk-Choon
    • Restorative Dentistry and Endodontics
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    • v.23 no.1
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    • pp.304-315
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    • 1998
  • The purpose of this study was to evaluate the microleakage of light cured glass ionomer restorative materials in class 5 cavities. In this in vitro study, class 5 cavities were prepared on buccal and lingual surfaces of forty extracted human premolars and molars on cementum margin. These specimen were randomly divided into four groups of 10 each : Group 1 was Fugi II (control), Group 2 was Fugi II LC, Group 3 was Vitremer, and Group 4 was Dyract. Group 2 was also divided once more into 2 groups of 5 each : Group 2-1 was pretreated with dentin conditioner and Group 2-2 was not. All teeth were restored according to the manufacturer's instructions. After 500 thermocycling between $5^{\circ}C$ and $55^{\circ}C$, the 40 teeth were placed in 2 % Methylene blue dye for 24hr, then rinsed with tab water. The specimen were embedded in clear resin, then sectioned buccolingually through the center of restoration with a low speed diamond saw. The dye penetration on each of the specimen were then observed with a stereomicroscope at 20. The results of the study were statistically analyzed using the Student-Newman-Keuls Methods and the Mann-Whitney Rank Sum Test. Tooth restorative interfaces were evaluated using SEM analysis. Results were as follows, 1. Compared to conventional glass ionomer restoratioqs, all light cured glass ionomer restorations were fairly resistant to microleakage (P<0.05). 2. Groups 3 (Vitremer) and Group 4 (Dyract) were found to be the most resistant, Group 2 (Fugi II LC) fairly resistant, and Group 1 (Fugi II) least resistant to microleakage(P<0.05). 3. No significant differences were found between Group 2-1 and Group 2-2 (P>0.08). 4. With the backscattered SEM analysis, the degrees to which tight bonding occurred were also observed in all the groups except for Group 1. Group 4 showed the highest degree of tight bonding than any other materials used in this study.

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Diurnal changes of Tissue Water Relations in Two Allopatric Tree Species (이소적 두 수종의 수분관계 일변화)

  • Park, Yong-Mok
    • The Korean Journal of Ecology
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    • v.19 no.5
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    • pp.453-463
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    • 1996
  • Diurnal changes of microclimatic conditions and tissue water relations were measured at two sites where Carpinus laxiflora and C. cordata were allopatrically distributed. The microclimatic conditions at a site where C. laxiflora was distributed produced severe water stress condition during summer months. Daily maximum temperature reached $30.4^\circC$ and the highest vapor pressure deficit was 1.31 KPa when 13 rainless days were continued. During this period soil water content decreased to below the field capacity even at a depth of 20 cm and xylem pressure potential also decreased to ­2.04 MPa. However, turgor potential was maintained more than 0.4 MPa. Patterns of stomatal conductance were changed with evaporative demand and soil water availability. On the other hand, microclimatic conditions at a site where C. cordata was distributed were moderate water strees condition compared with those at a site C. laxiflora was distributed. Though soil water content was maintained above field capacity C. cordata showed a remarkable decrease in turgor potential and stomatal conductance throughout the experiment. These results indicate that there is a difference in habitat characteristics between the two species and C. laxiflora is more resistant than C. cordata to water stress.

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Perfluorinated Compounds; New Challenge and Problem (과불화 화합물 (PFCs); 새로운 도전과 과제)

  • Son, Hee-Jong;Yoo, Soo-Jeon;Roh, Jae-Soon
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.12
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    • pp.1151-1160
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    • 2009
  • Perfluorinated compounds (PFCs) have been recognized as emerging environmental pollutants and are widely distributed all over the world. These compounds are hardly degradable and cause bioaccumulation and biomagnification during present for a long time in the environment: thereby after adversely biota and human bodies. It is difficult to remove PFCs using conventional water/wastewater treatment because of resistant property to photodecomposition, biodegradation and chemical decomposition. Moreover, domestic literature data on the pollution of PFCs in rivers and lakes are limited. In this paper, species, sources and risk of PFCs as well as behavior properties in drinking water/wastewater and treatment processes are demonstrated to encourage the domestic concern about PFCs.