• Journal of Environmental Science International
• /
• v.21 no.12
• /
• pp.1495-1501
• /
• 2012

In this study, an experiment was conducted on influent water with low concentrations of organic matter, such as river water or secondary treatment water of a sewage treatment plant, according to HRT changes by using aerobic biofilm. In the biofilm process, as the biofilm increases in thickness, the inner membrane can be low in oxygen transfer rate and become anaerobic conditions, while the detachment of biomass from biofilm occurs. To overcome these limitations in the detachment of microorganisms in biofilm, the yarn, which was made from poly propylene(PP), was weaved and manufactured into a tube. Then, a test was carried out by injecting air so that the interior of the biofilm could create aerobic conditions. The results of the experiment showed that the removal efficiency of $TCOD_{cr}$ reached 66.1~81.2% by HRT 2hr, and 50.9 ~61.8% after HRT 1 hr. The removal efficiency of $SCOD_{cr}$ was 45.9 to 55.1% by HRT 1hr, and 26.1% in HRT 0.5hr, showing the highest removal efficiency in HRT 1hr. The SS removal efficiency was at 81.8 to 94.6%, and the effluent SS concentration was very low, indicating less than 2.2 mg/L in all HRT's. As a result, the $SCOD_{cr}$ and $NH_4{^+}$-N that were removed per specific surface area and attached to microbial biofilm showed the highest efficiency in HRT 1hr with 8.37 $gSCOD_{cr}/m^2{\cdot}d$, 2.93 $gNH_4{^+}-N/m^2{\cdot}d$. From the result of reviewing the characteristics of biofilm growth, microorganisms were found to be attached, and increased by 36 days. Later, they decreased in number through detachment, but showed a tendency to increase again 41 days later due to microbial reproduction.

• 한국방재학회:학술대회논문집
• /
• 2009.02b
• /
• pp.158.1-158.1
• /
• 2009

• The Journal of Korean Medicine
• /
• v.26 no.2 s.62
• /
• pp.182-194
• /
• 2005

Objectives: After the discontinuance of the Women's Health Initiative (WHI)clinical trial in the U.S. in July 2002, I thought that the domestic medical field would come to a crisis in hormonal treatment for perimenopausal and postmenopausal women. However, the domestic condition of HRT has barely changed. This study was designed to investigate world research trends in HRT and bring forward the response of the Traditional Korean Medicine (TKM) Research Group. Methods: I investigated recent domestic ;md world research trends about HRT and climacteric syndrome. Based on this analysis, I predicted western medical research trends and direction for HRT and medical care of perimenopausal and postmenopausal women. Results and Conclusions: I propose that we (TKM Research Group) have to explain the side effects of HRT for postmenopausal women and try to suggest complementary therapy for it. For that aim, the Association of Korean Medicine's effort is very important, as well as personal practitioner's actions.

• Korean Journal of Clinical Pharmacy
• /
• v.10 no.1
• /
• pp.7-12
• /
• 2000

This study is intended to provide information to menopausal women so they can control their symptoms. The basic data was gathered by interviewed 200 postmenopausal women on a HRT program. The women were questioned about their perception of menopause and compliance to the therapy with the fellowing result $71.7\%$ of the women experianced hot flushes, and $64.1\%$ experienced short term memory loss and some psychological symptoms. The women reported that these symptoms reduced their quality of life. $53\%$ of the women responded that menopause is a natural state and $59.1\%$ agreed to HRT based on their doctor's recommendation. $76.2\%$ of the women reported that HRT was effective, with $74.7\%$ reporting reduced hot flush symptoms $67.3\%$ of the women reported compliance with the medication schedule. and $43.9\%$ reported periodic non-compliance. Although HRT has been shown to be an effective treatment, the study found that less than $10\%$ of postmenopausal women are currently being treated and these treated women are generally negligent in continuing with HRT, The study recommends that a program be developed that explains the benefits and risks of HRT to be distributed to patients being treated by doctors and pharmacists. In conclusions, It is very important for hormone replacement therapy on menopausal women to take more intensive medication consultation to increase medication compliance and effectiveness of pharmacotherapy.

• Journal of Environmental Health Sciences
• /
• v.19 no.3
• /
• pp.17-21
• /
• 1993

Characteristics of a downflow anaerobic packed bed reactor with raschig ring ceramics as a packing were measured and discussed for the basic evaluation of the process. A synthesized glucose substrate wastewater were used as a feed and process characteristics such as pH, biogas production, composition of produced gas, COD removal and VSS were measured with the hydraulic retention time (HRT) changing from 0.25 to 2 days. As a result, this type of reactor was applicable in continuous operation within the given HRT range and the transient period approaching the steady state was about 20 days. The content of methane in produced gas increase with HRT was always high above 50% enough to use as energy source. The COD removal efficiency increased gradually as HRT increased. The axial profile of VSS concentration in the reactor usually showed the maximum at the lower region and the minimum at the middle. The VSS concentration at the upper region and the exit appeared similarly. However, at 0.25 day of HRT, the VSS concentration of effluent became higher than that of the upper region. Therefore the optimum HRT of this reactor occurred about 0.5 day, at which the production of methane began to be just stabilized and loss of VSS and COD removal were resonable.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.2
• /
• pp.970-976
• /
• 2013

An evaluation of the organic matter removal efficiency showed high removal efficiencies of 91.1~96.3% and 91.4~97.5% for TCODcr and TBOD5, respectively, for 9hr or longer of HRT. However, the removal efficiencies decreased to 86.9~90.5% and 88.0~90.9%, respectively for 6hr of HRT. $NH_3$-N showed a high removal efficiency of 95% or higher for 9hr or longer of HRT. The total nitrogen removal efficiency was 67.6~76.7% for 9~12hr of HRT, and it decreased to 50% for 6hr of HRT, which seems to be due to the insufficient carbon source required for denitrification. The T-P removal efficiency was 32% on average. To comply with the legal standards, a chemical phosphorus removal process is needed after the reactor.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.10 no.3
• /
• pp.68-73
• /
• 2002

Acidogenic fermentation of primary sludge was investigated for the solution to reduce the sewage sludge and develope external carbon source for BNR process. In a viewpoint to use existing anaerobic digestion tanks, we didn't change environmental factors such as reactor configuration, temperature, pH and investigate the variation of solubilization rates, acidification rates and environmental factors which affected by the variation of HRT. The average solubilization rates were 0.0309 and $0.0204mgSCOD_{prod.}/mgICOD_{inf.}$ at a HRT of 3 and 1.5 days, respectively. The average acidification rates were 0.0068mg HAc/mg $TCOD_{inf.}$ and 0.0652mg HAc/mg $VSS_{destroyed}$ at a HRT of 3day. At a HRT of 1.5 days the average acidification rates were 0.0060mg HAc/mg $TCOD_{inf.}$ and 0.0346mg HAc/mg $VSS_{destroyed}$. For the period of experiments alkalinity and pH were properly maintained without artificial adjusting.

• Journal of Korean Society on Water Environment
• /
• v.23 no.6
• /
• pp.961-965
• /
• 2007

In this study, degradation of carbohydrates and composition of fermentative products were investigated in semi-continuous acid fermenter varying hydraulic retention time (HRT). Rice soup was used as a sole substrate for the acid fermentation. Solubilization efficiency of the substrate was higher than 70% for all HRT, however the gas conversion was ignorable implying that most of organic contents in the influent remained in the form of volatile fatty acids (VFAs) and ethanol after acid fermentation. The VFAs were the predominant product and the VFAs conversion increased as the HRT decreased. The VFAs conversion reached the maximum value at 12 hr HRT accounting for 70% of the influent COD. Similar to VFAs, ethanol conversion was increased with the decrease of HRT and the maximum ethanol conversion efficiency was 8% at the HRT of 12 hr. Composition of VFAs was markedly dependent on HRT. As HRT increased, the composition of acetic acid was increased as a product of acetogenesis from butyrate, valerate and ethanol. This study demonstrated that HRT affected acid fermentation of a carbohydrate containing organic wastes producing VFAs and ethanol which could be effectively used to compensate the lack of carbon in wastewater for biological nutrient removal.

• Journal of Aquaculture
• /
• v.10 no.3
• /
• pp.335-346
• /
• 1997

Denitrification is one of the important processes of removing nitrate from in recirculating aquaculture systems. And this process is affected by many factors such as external organic carbon sources, hydraulic retention time (HRT), COD/NO3--N (C:N) ratio, etc. However, not many studies were done for the optimum conditions of denitrification in the recirculation system for aquaculture. Therefore, this study was conducted to find out the optimum removal condition of NO3--N using submerged denitrification biofilter. The combinations of two external organic carbon sources (glucose and methanol), two HRT (4 and 8-hour) and four differnent C : N ratios (3, 4, 5, 6) were tested. The removal efficiencies of NO3--N and total inorganic nitrogen (TIM) at 8-hour HRT were better than those at 4-hour's (P<0.05). The maximum removal efficiency of NO3--N by methanol (97.8%) was achieved at HRT and C : N ratio were 8-hour and 4.0 respectively. The efficiencies of methanol for the removal of NO3--N and TIN were always better than those of glucose (P<0.05). The maximum removal efficiencies of total inorgainc nitrogen (TIN) were gained at C : N ration of 5.0. The maximum removel efficiencies of TIN using methanol and glucose were 96.9% and 71.5% respectively. Anaerobic condition which is necessary for denitrification process was not made until the 8-hour HRT and higher C : N ratio (5.0). Removal of NO3--N at 4-hour HRT and C : N ration lower than 5.0 were inhibited by oxygen and/or low quantity of external organic carbon. Removal efficiencies of NO3--N were also inhibited by high C : N (6.0) ratio when HRT was 8-hour.

• Women's Health Nursing
• /
• v.7 no.4
• /
• pp.642-656
• /
• 2001

The purpose of this study is to find the difference of the climacteric symptoms and quality of life according to hormone replacement therapy (HRT) in climacteric women. The research design was a descriptive survey with questionaries. A convenience sample of 181 climacteric women aged 45-65 who had climacteric symptoms were selected in Kwangju city, Korea. Sixty-six climacteric women among those subjects were receiving HRT at K university hospital in Kwangju city. Data were collected by the interview with questionaries from Feb 3. 1999 to March 25, 1999. Climacteric symptoms were measured using scores developed by Neugarten(1965) and modified by Park(1989), and the quality of life scale related to climacteric symptoms developed by Hildtich(1996) and modified Kim(1998). Data were analyzed by $x^2$-test, t-test, ANOVA and Pearson's correlation procedures, using SAS/win PC+. The results were as follows ; 1. No statistically significant differences were found between the receiving HRT group and not receiving HRT group in demographic, obstetrical and health related characteristics. 2. There were no significant difference on the climacteric symptoms between the group of women receiving HRT (score 2.4) and the group of women who were not (score 2.6) except psychological area (t= 2.407, p= 0.017). 3. The quality of life of the group of women receiving HRT was significantly higher than that the group of women who were not (t=2.151, p=.032). 4. The quality of life of the group of women receiving HRT were high scores There were significantly high of the quality of life in the vaso-motor change area (t=2.634, p= 0.009), psycho-social change area (t=3.239, p=0.001), and physical change area (t=2.031, p=0,043) in the group of receiving HRT compared to not receiving HRT group. 5. The variables showed significantly differences on the degree of climacteric symptoms of the group of women not receiving HRT were the subjective health state (t=15.81, p=0.000), age (t=7.50, p=0.007), feeling of menopause (t=30.88, p=0,000) and climacteric periods (t=8.66, p=0.003), and receiving HRT were number of para (t=3.95, p=0.050) and feeling of menopause (t=3.94, p=0.050). 6. The variables showed significantly difference on the quality of life of the group of women not receiving HRT were the subjective health state (t=4.14, p=0.044) and feeling of menopause (t=10.86, p=0.001). 7. There were significantly positive correlations between the climacteric symptoms and the quality of life in climacteric women (r=0.512, p=0.000).