• Membrane and Water Treatment
• /
• v.13 no.5
• /
• pp.235-243
• /
• 2022

The paper presents the effect of operating temperatures and flow rates on the distillate flux that can be obtained from a hydrophobic membrane having the characteristics: pore size of 0.15 ㎛; thickness of 130 ㎛; and 85% porosity. That membrane in the present investigation could be the direct contact (DCMD) or the air-gap membrane distillation (AGMD). To model numerically the membrane distillation processes, the two-dimensional computational fluid dynamic (CFD) is used for the DCMD and AGMD cases here. In this work, DCMD and AGMD models have been validated with the experimental data using different flows (Parallel and Counter-current flows) in non-steady-state situations. A good agreement is obtained between the present results and those of the experimental data in the literature. The new approach in the present numerical modeling has allowed examining effects of the nature of materials (Polyvinylidene fluoride (PVDF) polymers, copolymers, and blends) used on thermal properties. Moreover, the effect of the area surface of the membrane (0.021 to 3.15 ㎡) is investigated to explore both the laminar and the turbulent flow regimes. The obtained results found that copolymer P(VDF-TrFE) (80/20) is more effective than the other materials of membrane distillation (MD). The mass flux and thermal efficiency reach 193.5 (g/㎡s), and 83.29 % using turbulent flow and an effective area of 3.1 ㎡, respectively. The increase of feed inlet temperatures and its flow rate, with the reduction of cold temperatures and its flow rate are very effective for increasing distillate water flow in MD applications.

• Journal of the Korean Dietetic Association
• /
• v.19 no.3
• /
• pp.287-297
• /
• 2013

This study examined the effectiveness of nutrition education and program using the diet rice bowl during a four-week diet program. Thirty-eight female college students were randomly assigned to a nutrition education (NE) group or a nutrition education and diet rice bowl (ND) group. The mean energy intake of the NE and ND group during the program was 1,130.8 kcal and 1,287.4 kcal, respectively. The total energy intake of both groups were significantly decreased during the program. In addition, the change of body weight and fat in both groups significantly decreased during the program. The NE group lost 2.8 kg of body weight and 1.4% of body fat, while the ND group lost 2.5 kg of body weight and 1.2% of body fat. The changes in total cholesterol and LDL-cholesterol in both groups also significantly decreased during the program. However, there were no significant differences in the changes of body weight, body fat mass, the total cholesterol and LDL-cholesterol between the two groups. This study could not identify a weight reduction effect of the diet rice bowl, however, this may be due to subjects' infrequent use of the diet rice bowl by their frequent meal skipping and eating-out in our study. Therefore, further studies regarding the compliance to the diet rice bowl should be conducted to examine its effectiveness on weight control.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.25 no.1
• /
• pp.35-41
• /
• 2017

The use of engineering plastics in automotive components is increasing with the trend towards improving the car strength and reducing weight. Among the different choices of materials, engineering plastic emerged as the necessary material for achieving lower costs, reduced weight and improved production efficiency. To produce the automotive parts, it is important to predict defect and validation of injection molding prior to design. Injection molding analysis and structural analysis are widely applied as a part of the design process when developing automotive parts. Injection molding analysis, in particular, involves a highly complicated mechanism that requires deep knowledge of polymer properties as well as an analytic approach different from that used for a general isotropic material when the molded material is used as a structural material. This is because the parts made of polymer have pre-stress factors such as intrinsic deformation and residual stress. The most important factors for injection molded plastic products are injection molding condition and cavity design, taking into account ease of molding, mass production and application. Despite optimal injection molding conditions and cavity design, however, glass fiber orientation is critically linked to strength reduction. The application of injection molding and structural coupled analysis provides a low-cost solution for product molding and structural validation, all prior to the actual molding. The purpose of this study involves the validation, pre-study, and solution of defect in injection-molded polymer automotive parts using the simulation software for injection molding and structural coupled analysis. Finally, this thesis provides validation of an injection molding and structural coupled analytic mechanism that can demonstrate the effect of glass fiber orientation on mechanical strength. Design improvement ideas for the injection molded product of PPS (Poly Phenylene Sulfide)+40% glass fiber are also suggested.

• Natural Product Sciences
• /
• v.13 no.2
• /
• pp.152-159
• /
• 2007

To demonstrate anti-hyperlipidemic activity of the 19${\alpha}$-hydroxyursane-type triterpenoid (19${\alpha}$-HUT)-rich fraction, this fraction was prepared from the extract of Rubus crataegifolius leaves. This fraction was found to have anti-hyperlipidemic effect in a high fat diet-induced rat model from the observation of reduction of abdominal fat pad weights, atherogenic index and hypercholesterolemia at 30 and 60 mg/kg (p.o.) The 19${\alpha}$-HUT fraction was subjected to SiO$_2$, ODS, and/or Sephadex LH-20 column chromatography to yield a new triterpenoid (1) called pomolic acid ester along with nine known triterpenoids which are all 19${\alpha}$-HUTs: euscaphic acid (2), tormentic acid (3), 23-hydroxytormentic acid (4), kaji-ichigoside F$_1$ (5), rosamultin (6), niga-ichigosides F$_1$ (7) and F$_2$ (8), suavissimoside F$_1$ (9) and coreanoside F$_1$ (10). The structure of compound 1 was established as 28-O-formyl-3,19-dihydroxyurs-12-en-28-oic acid on the basis of 2D-NMR spectroscopic data and mass spectrum. Compound 1 was isolated for the first time from natural sources.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.5
• /
• pp.2845-2850
• /
• 2013

Background: Breast cancer is one of the most frequent diseases in women today. Little information exists on modifiable lifestyle factors including effects of ginger supplements (as an anti-oxidant and anti-inflammatory herbal) and water-based exercise on biomarkers related to oxidative stress such as malondialdehyde (MDA), nitric oxide (NO) and glutathione peroxidase (GPx) and adiponectin in obese women with breast cancer. The aim of this study was to determine the single and concomitant effect of 6-wks water-based exercise and oral ginger supplement on the aforesaid markers in obese women with breast cancer. Materials and Methods: Forty women diagnosed with breast cancer ($48{\pm}5.4$ years, $76{\pm}9$ kg, fat mass $41.8{\pm}4%$), volunteered to participate in the study. Subjects were randomly assigned into four groups; placebo, water-based exercise, ginger supplement and water-based exercise+ginger supplement groups. Subjects in the ginger supplement group and the water-based exercise+ginger supplement group orally received 4 capsules (each capsule contained 750 mg), 7 days a week for 6 weeks. The water-based exercise program featured progressive increase in intensity and time, ranging from 50% to 75% of heart rate reserve, in a pool with 15 meters width, 4 times a week for 6 weeks. Fasting blood samples were collected at pre-test and post-test time points. Results: The ginger supplementation and or the water-base exercise resulted in an increase of adiponectin, NO and GPx and reduction MDA, as compared to pre-test values. However, the combined intervention (water-base exercise and ginger supplement) group showed significantly a far better effect on the biomarkers related to oxidative stress and adiponectin levels, as compared to the waterbase exercise or ginger supplement alone groups and the age-matched placebo group. Conclusions: Our results revealed that water-base exercise is a non-drug therapeutic strategy to reduce systemic stress in obese women suffering from breast cancer. Further, ginger supplementation alone or in combination with training, also play an important role in the pathogenesis of oxidative stress in obese women diagnosed with breast cancer.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.11a
• /
• pp.184-187
• /
• 2007

Hydrogen could be produced from any substance containing hydrogen atoms, such as water, hydrocarbon (HC) fuels, acids or bases. Hydrocarbon fuels couold be converted to hydrogen-rich gas through reforming process for hydrogen production. Even though fuel cell have high efficiency with pure hydrogen from gas tank, it is more beneficial to generate hydrogen from city gas (mainly methane) in residential application such as domestic or office environments. Thus hydrogen is generated by reforming process using hydrocarbon. Unfortunately, the reforming process for hydrogen production is accompanied with unavoidable impurities. Impurities such as CO, $CO_2$, $H_2S$, $NH_3$, and $CH_4$ in hydrogen could cause negative effects on fuel cell performance. Those effects are kinetic losses due to poisoning of electrode catalysts, ohmic losses due to proton conductivity reduction including membrane and catalyst ionomer layers, and mass transport losses due to degrading catalyst layer structure and hydrophobic property. Hydrogen produced from reformer eventually contains around 73% of $H_2$, 20% or less of $CO_2$, 5.8% of less of $N_2$, or 2% less of $CH_4$, and 10ppm or less of CO. Most impurities are removed using pressure swing adsorption (PSA) process to get high purity hydrogen. However, high purity hydrogen production requires high operation cost of reforming process. The effect of carbon dioxide on fuel cell performance was investigated in this experiment. The performance of PEM fuel cell was investigated using current vs. potential experiment, long run (10 hr) test, and electrochemical impedance measurement when the concentrations of carbon dioxide were 10%, 20% and 30%. Also, the concentration of impurity supplied to the fuel cell was verified by gas chromatography (GC).

• Journal of Plant Biotechnology
• /
• v.44 no.3
• /
• pp.335-342
• /
• 2017

Purple passion fruit (Passiflora edulis Sims) is one of the introduced tropical plants, an increasing interest has arisen due to its distinctive taste and attractive flavor. It is expected that passion fruit production and planted area will increase gradually in the years ahead because of high profitability and consumer's demands of healthful ingredients. So we tried to investigate the effect of plant growth regulators and antioxidants on in vitro plant regeneration and callus induction from leaf explants of passion fruit for an establishment of optimal mass propagation system. Young leaf explants of purple passion fruit were cultured in Murashige and Skoog (MS) medium containing different growth regulators and antioxidant additives to induce the shoot organogenesis. After 8 weeks, the highest embryogenic callus formation rate was obtained in MS medium supplemented with $1mg{\cdot}L^{-1}$ 6-benzylaminopurine (BAP) and $2mg{\cdot}L^{-1}$ 2,4-dichlorophenoxyacetic acid (2,4-D), furthermore, the shoot development via organogenesis was also observed. Silver nitrate ($AgNO_3$), which was added into the medium to minimize the adverse effects of leached phenolics, was effective for reduction of medium browning and sudden explant death. In the medium supplemented with $1mg{\cdot}L^{-1}$ BAP and $1mg{\cdot}L^{-1}$ gibberellic acid ($GA_3$), shoots were most vigorously regenerated and elongated. Most shoots rooted successfully in half strength medium with $1mg{\cdot}L^{-1}$ indol-3 acetic acid (IAA), and more than 90% of plantlets survived after 4-month acclimatization period.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.28 no.4
• /
• pp.35-41
• /
• 2020

The immobilization of the hydroxylamine-oxidoreductase on the water channel surface was performed to investigate the efficacy of ammonia removal in turbulent flow. The reaction by this enzyme proceeds rapidly by converting hydroxylamine into nitrous acid. For the analysis of the effect, a dimensionless mass transfer governing equation was established with the physical properties based on room temperature. The ammonia diffusion coefficient in water and the kinematic viscosity coefficient of water were 2.45×10-9 ㎡/s and 1×10-6 ㎡/s, respectively. The distribution of ammonia concentration in the water was calculated with respect to the distance from the point at which exposure to ammonia began. The quantitative distribution with respect to the mixing depth was also found. Such a quantitative analysis can provide insight into whether the enzyme immobilized on the water channel surface can be effectively used for ammonia removal.

• Korean Journal of Pharmacognosy
• /
• v.33 no.4 s.131
• /
• pp.337-342
• /
• 2002

The effect of water extract composed of panax ginseng radix rubra, acanthopanacis cortex, and cordyceps (PAC) on diabetic animal models were investigated in two different diabetic animal models. FAC water extract significantly reduced the plasma glucose levels on day 30 as compared with the diabetic control group in $KKA^Y$ obese, hyperglycemic and hyperglycemic and hyperinsulinemic mice, and also reduced the plasma glucose levels as well as total cholesterol in multiple low dose (MLD) strep tozotocin-induced diabetic SD rats. PAC water extract also showed an inhibitory effect on reduction of body weight and on development of MLD STZ-induced diabetic state. Elevated kidney hypertrophy, which is a characteristic feature shown in early stage of diabetic nephropathy and calculated as the ratio of kidney mass (g) relative to the body weight (g), was also markedly improved in PAC water extract- treated group as compared to the diabetic control group. Taken together, these data suggest that PAC water extract may have a potential as a antidiabetic agent in type 2 diabetes mellitus.

• Journal of the Korean Dietetic Association
• /
• v.20 no.2
• /
• pp.123-132
• /
• 2014

This study investigated the effect of food consumption monitoring and real-time communication-based weight control program using a smartphone on weight reduction and maintenance in obese women. This study consisted of two phases: an 8-week weight control program with food consumption monitoring and real-time communication using a smartphone and an 8-week follow-up. Sixteen obese female college students (>30% body fat) participated in this program, and we measured changes in body composition and dietary intake volume. Follow-up analysis focused on weight maintenance after 8 weeks of no contact. Total energy intake (P<0.01), body weight (P<0.001), percent body fat (P<0.001), body fat (P<0.05), and body mass index (P <0.001) decreased significantly after the 8-week weight control program. However, we could not observe total energy intake or body composition regain after the follow-up period. These results suggest that food consumption monitoring and real-time communication using a smartphone can be effective for weight control and maintenance.