• Clinical and Experimental Reproductive Medicine
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• v.20 no.1
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• pp.65-70
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• 1993

To maintain a good sperm motility is one of the key factors for the successful artificial insemination in retrograde ejaculation, and the sperm motility has been shown to be affected by various environmental factors, including change in pH and osmolarity. Herein we have analyzed the effect of change in pH and osmolarity in urine and normal saline on sperm motility by Sperm Quality Analyzer and Makler counting chamber. Semen, which sampled by masturbation from a 28 year old male and showed normal finding on semen analysis, was used for this study. The results were as follows: 1. When osmolarity was fixed to 300mOsm, pH did not show a definite effect on the sperm moility. However, the motility was generally a bit better in alkaline urine and saline than in acid, particularly than in pH 5.0. 2. When pH was fixed to 7.5, sperm motility was best in urine and saline of 300mOsm. Hyperosmolarity had more adverse.effect on the motility than hypoosmolarity. 3. The sperm motility was worse in the urine than in saline under the same pH and osmolarity. In conclusion, osmolarity has a definite effect on sperm motility, where as pH has relatively little effect. And certain components of urine other than pH and osmolarity might affect the sperm motility.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.413-420
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• 2016

Hydroxy acid has been used to enhance anti-aging and skin moisturization by peeling effect on the skin stratum corneum, and thus it has been widely used in topical products and cosmetic products. Among them, the effect that appears most effectively in a short period of time has been reported to be effected by the pH of the cosmetic formulations. However, there are many difficulties in use due to irritation caused by pH and concerns about side effects. The purpose of this study was to evaluate the effect of applying cosmetics with (1) varying concentrations, (2) types and (3) pH of hydroxy acid on human skin. 22 healthy adults were stained with DHA (dihydroxyacetone) and DC (dansyl chloride) on the forearm, and the skin exfoliation effect was measured after application of the test products. (1) The application of GA (glycolic acid) increased the desquamation by concentration dependent. (2) the test product prepared with neutral pH showed no exfoliation effect. In contrast, SA (salicylic acid) showed a statistically significant exfoliation effect at both acidic pH and neutral pH. (3) The neutral pH SA showed excellent exfoliation effect on bot DHA and DC stained stratum corneum. These results suggest that it is possible to manufacture safe cosmetics without damaging the skin barrier, providing an opportunity to use cosmetics that are expected to exfoliate to people, whose skin is sensitive to pH.

• Journal of Environmental Science International
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• v.16 no.7
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• pp.779-784
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• 2007

Dinitrophenol is preventing cells from making energy for growth and it has been suggested that pH may be important in mitigating effects of uncouplers. The effect of pH on toxicity of dinitrophenol at high concentration was investigated, over a pH range of 5.7 to 8.7. DNP inhibition was found to be strongly dependent on mixed liquor pH. The DNP degradation rate was highest in the pH range of 7.0 to 7.8; at pH 6.0 degradation of 0.41 mM dinitrophenol was significantly inhibited; at pH <5.7, dinitrophenol degradation was completely inhibited after approximately 25% of the dinitrophenol was degraded. However no significant effect of pH variation was seen on glucose uptake by the activated sludge mixed culture.

• Journal of Environmental Science International
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• v.13 no.7
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• pp.667-674
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• 2004

The objective of this study was to investigate the effects of pH and temperature on the formation of bromate, which is ozonation by-products, during ozonation. In this experiment, the operating parameters including pH 3 ～ 10 and temperature 15 ～ $30^{\circ}C$ were studied. Through the study for the bromate formation, reaction rate constant, and ozonation effect index on pH and temperature, the results obtained are as follows. At the same initial pH condition, the increase of pH shown similar trends even if the reaction variables such as temperature and reaction time of ozonation were exchanged. As pH and temperature were increasing, the bromate concentration was increased but bromine(HOBr+OBr) was decreased with increasing pH from 3 to 10. The activation energy(J/mol) for bromate formation decreased with increasing pH. The rate constants of bromate formation for the reaction of ozone and bromide, and ozone dosage coefficient$(K_{0})$ increased with temperature and pH. Ozonation effect index(OI) decreased with increasing temperature and pH.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.1
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• pp.96-101
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• 1998

Substrate inhibition of 2,4-dinitrophenol (DNP) degradation was investigated using activated sludge which had been adapted to mineralize DNP. DNP is a metabolic uncoupler, preventing cells from making energy for growth and it has been suggested that pH may be important in mitigating effects of uncouplers. After acclimation of the activated sludge, the effect of pH on toxicity of DNP at high concentration (75 mg/L) was investigated, over a pH range of 5 to 9. DNP inhibition was found to be strongly dependent on mixed liquor pH. The DNP degradation rate was highest in the pH range of 6.95 to 7.84; at pH 5.94 degradation of 75 mg/L DNP was significantly inhibited; at pH < 5.77, DNP degradation was completely inhibited after approximately 30% of the DNP was degraded. By comparison, no significant effect of pH variation in the same range was seen on glucose uptake by the activated sludge culture.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.112-120
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• 1998

This study was performed to investigate the synergistic effect of chitosan and sorbic acid as a new food preservative. So it was performed to investigate inhibitory effect on growh of E. coli 0157:H7, gram negative pathogenic food borne disease bacteria and of S. aureus, gram positive food borne disease bacteria in chitosan, sorbic acid and combination of chitosan and sorbic acid. Minimun Inhibitory Concentration (MIC) of chitosan in E. coli 0157:H7 was 500 ppm at pH 5.0, 250 ppm at pH 5.5, 500 ppm at pH 6.0, and 2000 ppm at pH 6.5, while in Staph. aureus 31.25 ppm at pH 5.0 and 62. 5 ppm at more than pH 5.5. also, MIC of sorbic acid in E. coli 0157:H7 was 500 ppm at pH 5.0, 1500 ppm at pH 5.5, and 2000 ppm at more than pH 6.0, while in Staph. aureus 1500 ppm at pH 5.0 and more than 2000 ppm at more than pH 5.5. Due to the effect of pH in E. coli 0157:H7, MIC of combined chitosan and sorbic acid was 500 ppm of chitosan with 500 ppm of sorbic acid at pH 6.5, but 250 ppm of chitosan with 31.3 ppm of sorbic acid at pH 5.0. In Staph. aureus, there was great effect of chitosan, but neither effect of pH nor sorbic acid. When E. coli 0157:H7 were treated with 500 ppm of chitosan with 500 ppm of sorbic acid and 250 ppm of chitosan with 250 ppm of sorbic acid at pH 6.5, they were inhibited. But, they were increased at the initial concentration of bacteria at 1000 ppm of chitosan in 18 hours, at 500 ppm of chitosan in 36 hours. There was no effect of growth inhibition with sorbic acid but great effect with chitosan on Staph. aureus. The correl~tions between MICs of chitosan and sorbic acid in E. coli 0157:H7 accoding to pH were higher than those in Staph. aureus. R values in E. coli 0157:H7 were 0.95 (p<0.01), 0.99 (p<0.01), 0.97 (p<0.01), and 0.99 (p<0.01) at pH 6.5, 6.0, 5.5, and 5.0 respectively. The synergistic effect of chitosan and sorbic acid in E. coli 0157:H7 could be confirmed from the result of this experiment. Therefore, it was expected that the food preservation would increase or maintain by using sorble acid together with chitosan, natural food additive that did no harm to human body.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.279-282
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• 2002

Twenty six male Hanwoo (Korean cattle) carcasses were measured for pH, temperature and instrumental color changes of loins during 24 h post-mortem carcass chilling at $4^{\circ}C$ in the cooler. The average internal temperature of loins was about $5^{\circ}C$ after 24 h of chilling, and with the exclusion of those with an ultimate pH>6.0 (dark-cutters), the average pH value was 5.5. When all carcasses were considered for the partial correlation coefficient between color and pH, with the temperature effect excluded, CIE $L^*$, $a^*$ and $b^*$ seemed to be affected significantly by pH during chilling process (p<0.001). However, when carcasses with dark-cutting condition were excluded, the correlation coefficients were much lower. In contrast, when the partial correlation coefficients between color and temperature, excluding the effect of pH on them, were analyzed, the relationship between color and temperature did not change much after values of DFD (dark, firm, dry) beef were excluded. The results suggested that the known interrelationship of color and pH in chilled beef loins be mainly due to the influence of temperature on pH and color.

• Journal of Biomedical Engineering Research
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• v.18 no.2
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• pp.173-178
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• 1997

pH sensitive polymers have long been utilized as one important type among many interesting drug delivery systems. This is due to the reason of different pH environments in human organs, which requires different pH control mechanism depending upon the organs. In the present study the pH sensitivity was investigated for both pH sensitive and pH insensitive biopolymers using the diffusion effect along with the swelling effect. NMR microscopy was performed along with optical microscopy. For the analysis of diffusion effect, UMR Microscopy was perFormed to measure diffusion coefficients for various liquids such as distilled water, acetone and DMSO(dimethyl sulfoxide). Also, this technique is expected to contribute to the studies for many pH drug delivery systems.

• Korean journal of applied entomology
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• v.10 no.1
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• pp.59-62
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• 1971

The highest fresh weight of Agaricus bisporus was obtained at pH 7.5 of casing soil. Above or below this pH level, the yields were significantly reduced. Stimulatory effect of calcium on the mycelial growth depended upon pH of casing soil, In neutral or slightly alkaline soil, the stimulatory effect was increased. The effects of supplementing calcium carbonate or hydrated lime to casing soil were assumed not only the influence of pH of casing soil, but also stimulatory effect of calcium ion on mycelial growth of A. bisporus.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.6
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• pp.867-876
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• 1987

Corrosion fatigue fracture with change in the grain size of M.E.F. dual phase steel is investigated in 3.5% NaCI aqueous solution at pH 2, 4, 6, 9, and 11. Generally speaking, decrease in corrosion fatigue life is strongly dependent on decrease in pH and slightly on the grain size. For the B material with the big grain size, the fatigue life is small due to its large reduction ratio of corrosion fatigue life. The influence of grain size on the reduction ratio of corrosion fatigue life is large at pH 11-6. Whi9le at pH 4-2 the reduction ratio of corrosion fatigue life only depends on the corrosion effect. The larger grain size and the lass pH result in the greater influence on corrosion fatigue crack propagation rate. As pH decreases, the plateau portion in the crack propagation rate curves of the B material are distinct. Crack propagation rate curves become slow down at high .DELTA.K range because crack closure effect by minute corrosion products inside crack causes the oxidation corrosion action less effective for a certain period of time. In A material with small grain size, fatigue life is increased in proportion with increase of martensite intergranular which brings forth restraining the crack propagation decreases crack propagation rate. Corrosion pit which is created in the surface of specimen is found at pH 6,4 and 2 which is noticeable and the unevenness of the surface of the specimen becomes severe as pH decreases. The unevenness of corrosion fatigue fracture surface is severe as the effect of pH increases i.e. as pH decreases. In proportion with increase in the grain size and decrease in pH, the aspect of brittle fracture becomes evident.