• 한국세라믹학회지
• /
• 제56권4호
• /
• pp.365-373
• /
• 2019

Pond ash is a mixture of mostly coarser fly ash and bottom ash. The recycling rate of pond ash is low because pond ash is mixed with seawater and deposited in ponds. The pond ash is also subjected to natural weathering over a period of time. In this study, we investigated whether pond ash can be used as a raw material of geopolymers, without any purification process or through a minimal purification process. In addition, we investigated whether synthetic basalt made by adding foaming agent to geopolymer or casting it into a mold can show the surface of the natural basalt as it is. The highest 7-day compressive strength in geopolymers from pond ash without purification process was 26 MPa. The highest 7-day compressive strength in geopolymers from pond ash with impurities removed through dry sieve analysis was found to improve to 80 MPa. On the other hand, synthetic basalt made with geopolymer was shown to be more advantageous aesthetically when produced by casting it in a silicone mold rather than by adding a foaming agent. Non-purified pond ash can be made into geopolymers having low strength. Pond ash purified by sieving can, without use of an aggregate, be made into geopolymer having high-strength. Also, it is possible to produce synthetic basalt with the same appearance as natural basalt and sufficient strength for commercialization. This process will contribute to the mass consumption and recycling of pond ash.

• Mycobiology
• /
• 제47권4호
• /
• pp.512-520
• /
• 2019

Statistical experimental methods were used to optimize the medium for mass production of a novel laccase3 (Lac3) by recombinant Saccharomyces cerevisiae TYEGLAC3-1. The basic medium was composed of glucose, casamino acids, yeast nitrogen base without amino acids (YNB w/o AA), tryptophan, and adenine. A one-factor-at-a-time approach followed by the fractional factorial design identified galactose, glutamic acid, and ammonium sulfate, as significant carbon, nitrogen, and mineral sources, respectively. The steepest ascent method and response surface methodology (RSM) determined that the optimal medium was (g/L): galactose, 19.16; glutamic acid, 5.0; and YNB w/o AA, 10.46. In this medium, the Lac3 activity (277.04 mU/mL) was 13.5 times higher than that of the basic medium (20.50 mU/mL). The effect of temperature, pH, agitation (rpm), and aeration (vvm) was further examined in a batch fermenter. The best Lac3 activity was 1176.04 mU/mL at 25 ℃, pH 3.5, 100 rpm, and 1 vvm in batch culture.

• Journal of Preventive Medicine and Public Health
• /
• 제48권2호
• /
• pp.84-93
• /
• 2015

Objectives: The present study was conducted in order to examine the association between socioeconomic status (SES) and osteoporosis prevalence in Korea and to assess whether different associations are found in single-person households. Methods: A cross-sectional population-based study was conducted using the Korea National Health and Nutrition Examination Survey, from 2008 to 2011. The study subjects were people aged ${\geq}50$ years with osteoporosis as defined by bone mineral density. Multivariate logistic models were used to estimate prevalence odds ratios (pORs) and 95% confidence intervals (CIs). Gender differences in the likelihood of osteoporosis were analyzed based on household income, education level, and residential area. Results: There were 8221 osteoporosis patients aged ${\geq}50$ years, of whom 927 lived in single-person households. There was a gender-specific association between osteoporosis prevalence and all three SES factors that we analyzed: income, education, and residential area. After adjusting for age, SES, and health behaviors, including body mass index (BMI), low household income was only significantly associated with osteoporosis in men, whereas education level had an inverse relationship with osteoporosis only in women (p=0.01, p<0.001, respectively). However, after controlling for age and BMI, rural residency was only associated with osteoporosis in women living in single-person households (pOR, 1.59; 95% CI, 1.05 to 2.43). Conclusions: The Korean adult population showed a gender-specific relationship between SES and osteoporosis prevalence, with a different pattern found in single-person households.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제15권3호
• /
• pp.34-43
• /
• 2010

The fate of hydrophobic organic contaminants (HOCs) in ground water is highly affected by the distribution and property of the carbonaceous materials (CMs) in subsurface sediments. CMs in soils consist of organic matters (e.g., cellulose, fulvic acid, humic acid, humin, etc.) and black carbon such as char, soot, etc. The distribution and property of CMs are governed by source materials and geological evolution (e.g., diagenesis, catagenesis, etc.) of them. In this study, the distribution and property of CMs in subsurface sediments near the Imjin river in the Republic of Korea and HOC sorption property to the subsurface sediments were investigated. The organic carbon contents of sand and clay/silt layers were about 0.35% and 1.37%, respectively. The carbon contents of condensed form of CMs were about 0.13% and 0.45%, respectively. The existence of black carbon was observed using scanning electron microscopes with energy dispersive spectroscopy. The specific surface areas (SSA) of CMs in heavy fraction(HFrCM) measured with N2 were $35-46m^2/g$. However, SSAs of those HFrCM mineral fraction was only $1.6-4.3m^2/g$. The results of thermogravimetric analysis show that the mass loss of HFrCM was significant at $50-200^{\circ}C$ and $350-600^{\circ}C$ due to the degradation of soft form and condensed form of CMs, respectively. The trichloroethylene (TCE) sorption capacities of sand and clay/silt layers were similar to each other, and these values were also similar to oxidzed layer of glacially deposited subsurface sediments of the Chanute Air Force Base (AFB) in Rantoul, Illinois. However, these were 7-8 times lower than TCE sorption capacity of reduced layer of the Chanute AFB sediments. For accurate prediction of the fate of hydrophobic organic contaminants in subsurface sediments, continuous studies on the development of characterization methods for CMs are required.

• 한국식생활문화학회지
• /
• 제31권4호
• /
• pp.373-380
• /
• 2016

The purpose of this study was to evaluate the nutrient intake, diversity and prevalence of diseases according to noodle consumption using data from the Korean National Health and Nutrition Examination Survey (KNHANES) of 2010. Korean adults (>20) were classified into two groups, noodle group (NG) and non-noodle group (NNG). NG was found to have higher intakes of protein, calcium, iron, sodium, potassium, and niacin. The DVS and DDS according to noodle consumption were found to be 21.76 and 3.51 for NG, and 18.56 and 3.40 for NNG, this result was thought to show that the diet of NG was more satisfactory than that of NNG in terms of dietary diversity. In the bone mass of entire subjects, NG showed higher figures in the femoral neck and lumbar spine than NNG. For bone mineral density, NG exhibited higher figures in the femoral neck, and for T-scores, the values of NG was significantly higher in the femoral neck than those of NNG. However, the prevalence of osteoporosis of NG and NNG was 11.6% and 9.5%. The prevalence of osteopenia of NG and NNG was 43.0% and 51.7%. Thus, these results showed that overall bone health of NG was better than that of NNG. Dietary balance and quality were also more satisfactory in NG. These results showed that noodle consumption may have an impact on the prevalence of chronic diseases.

• 생명과학회지
• /
• 제23권1호
• /
• pp.79-83
• /
• 2013

L-Cysteine에서 유도된 아미노산인 ATCA와 불용성 인산 가용화능을 가진 균주를 이용하여 미생물처리제 BIOACTIVE를 제조하고 안정성을 확인 하였다. 제조한 미생물처리제를 미생물 비료로 적용하고자 3회 관주 처리한 다음 상추모종의 생장촉진 효과를 조사하는 실험을 수행하였다. 그 결과로 처리한 시험 구에서 상추의 생육은 엽수, 엽장 및 엽중에서 최대 128%, 122% 및 153% 정도로 증가하였다. 처리 간에는 기준량(1,000배 희석) 처리> 반 량(500배 희석) 처리> 배 량(2,000배 희석) 처리 순으로 나타났다. 공시 BIOACTIVE의 처리가 토양 중의 유효인산 및 식물체내의 인산함량을 최대 118% 및 132% 정도 증가 시키는 경향이었다. BIOACTIVE제제를 처리했을 때 N, P, K 3요소를 관행으로 처리와 비슷한 생육 효과가 있는 것으로 보아 복합비료의 사용량을 줄여, 재배가 충분히 가능하리라 생각되며, 상추의 생육 및 비해 조사를 한 결과 본 관주 처리에서는 생육장해 및 비해는 없었다.

• 자원리싸이클링
• /
• 제18권3호
• /
• pp.27-35
• /
• 2009

부존자원의 대량소비로 인해 자원고갈 문제와 이에 따라 발생하는 폐기물처리 문제가 대두되고 있는 가운데 두 가지 문제를 동시에 해결하기 위해 현재의 사회구조를 자원소비형에서 자인순환형으로 변화하기 위할 노력이 진행되고 있다. 이런 노력의 일환으로 국내 발생 폐기물 중 가장 높은 비중을 차지하고 있는 건설폐기물에 관심이 급증하고 있지만 종합적인 처리에 대한 연구는 미흡한 실정이다. 본 연구에서는 건설폐기물의 가장 많은 단일 물질인 폐콘크리트의 자원순환을 위한 고품질 순환골재 생산 공정 연구를 진행하였다. 굵은 골재, 잔골재, 시멘트 등이 수화물의 형태로 결합되어 있는 폐콘크리트를 가열전처리 방법과 Autogenous mill을 이용한 단체분리를 통해 고품질의 콘크리트용 순환 굵은 골재를 회수하였으며, 파분쇄 후 생산된 폐콘크리트 미분은 sink/float 분리를 통한 비중분리 특성을 파악한 후 간섭침강분리를 통해 정제과정을 거쳐 고품질의 콘크리트용 순환 잔골재를 생산하였다. 따라서 본 연구를 통해 전체 건설폐기물 중 가장 높은 비중을 차지하는 폐콘크리트를 고품질 순환골재로 재활용 할 수 있는 자원순환형 처리 공정을 개발하였다.

• 대한기계학회논문집B
• /
• 제24권7호
• /
• pp.938-944
• /
• 2000

Recently, micro fin tube is widely used to heat exchanger for high performance. And, as the alternative refrigerants for R-22, hydrocarbons such as R-290, R-600 and R-600a are very promising because of their low GWP and ODP. Thus, R-290 was used as working fluid in this study. Most design of heat exchanger had been based on heat transfer characteristics of pure refrigerant although refrigerant oil exists in the refrigeration cycles. So, the influence of oil on heat transfer characteristics have to be considered for investigating exact evaporation heat transfer characteristics. But, this is an unresolved problem of refrigeration heat transfer. Therefore the influence of the refrigeration oil to the evaporation heat transfer characteristics of R-290 were conducted in a horizontal micro tin tube. The mineral oil was used as refrigeration oil. The experimental apparatus consisted of a basic refrigeration cycle and a system for oil concentration measurement. Test conditions are as the follows; evaporation temperature $5^{\circ}C$, mass velocity 100 $kg/m^2s$, heat flux 10 $kW/m^2$, oil concentration 0, 1.3, 3.3, 5.7 wt.%, and quality $0.07{\sim}1.0$. When refrigeration oil was entered, oil foaming was observed at the low quality region. And, very small bubbles were observed as quality was increased. Pressure drop and heat transfer coefficient increased as the concentration of refrigeration oil increased to 5 wt.%.. The performance index of heat exchanger was the highest near 3.3 wt.%.

• 사상체질의학회지
• /
• 제13권1호
• /
• pp.24-34
• /
• 2001

Objectives : The purpose of this study was to evaluate the body shape of Sasang Constitutions by body composition and body measurement. Methods : This study was carried out 98 cases(68 males and 30 females)of Oriental Medical College at Kyunghee University. After determining the Sasang Constitutions(Soeumin, Soyangin, Taeumin) by QSCCII, the body shape of each group were analysed by body composition(INBODY 2.0, Biospace, seoul, korea) and body measurement. Results : 1) The result of Sasang Constitution analysis of 98 cases were classified as Soumin(52%), Soyang(24.5%), Taeumin(23.5%). 2) In the body composition and body measurement, there were significant difference from intercellular fluid, protein, mineral mass, weight, percent body fat, body water of left arm and BMI between Taeumin, Soyangin and Soumin. 3) In the body composition of male, Taeumin group showed that the arms were more developed than the legs and the upper trunk were more developed than the lower trunk. Soumin group showed the asymmetry of the right and left limbs. Soyang group showed the asymmetry of the right and left arms. In the body composition of female, Taeumin group showed the asymmetry of the right and left upper limbs. Conclusion : There are significant relationships between Sasang Constitutions, Body composition and BMI. The findings indicated here Body composition could be useful mean to make a diagnosis of the body shape, body type, physical constitution of Sasang constitutions.

• 한국수정란이식학회지
• /
• 제28권4호
• /
• pp.325-335
• /
• 2013

The study was set for one year to measure the effects of concentrate supplementation on reproductive performances and semen quality in indigenous rams. The study was conducted at the Department of Surgery and Obstetrics, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh during the period from May 2011 to April 2012. Forteen ram lambs (4~5 months) were randomly divided into two equal groups (n=7); supplemented vs control. The animals of control group were maintained on natural grazing. Along with natural grazing the supplemented group was on supplemented feeding. The concentrate supplementation (Wheat bran, Crushed maize, Soy bean meal, Fish meal, DCP powder, Vitamin mineral premix, Salt) was provided @ 300 g/head /day to the supplemented group. Body weight, scrotal circumference, BCS and libido index were measured weekly. Age, body weight and scrotal circumference at puberty were recorded. Semen was collected once in a weak using artificial vagina and chilled at $5^{\circ}C$ for 48h for evaluation. Concentrate supplementation did not influence (p>0.05) body condition score, age, weight, scrotal circumference at puberty and libido index. Final body weight (kg), growth rate (g/d), scrotal circumference (cm) and scrotal growth rate (mm/15d) were significantly (p<0.05) higher in supplemented group of rams compared to control. Volume, concentration, motility and membrane potentiality of spermatozoa were varied significantly (p<0.05) in supplemented and control groups. However, density, mass motility, viability and sperm with normal acrosome, midpiece and tail were not differed insignificantly (p>0.05) in different observation times. It was concluded that concentrate supplementation with free grazing improved weight and scrotal circumference gain and semen production with increased quality in indigenous ram.