• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.1
• /
• pp.93-102
• /
• 1998

Infant formula in nursing bottle, with inappropriate feeding habits, is major factor associated with the development of nursing caries. Although each infant formula has different carbohydrate and protein composition, studies comparing cariogenic potential of many Korean-branded infant formulas are deficient. In addition, it is on the point of being difficult to evaluate the cariogenecity of milk due to development of many infant formulas. In this study, to evaluate the cariogenic potential of many infant formulas, after oral rinse with six Korean-branded infant formulas(three milk based formulas, one soy based formula and two specific formulas for infants with allergy to milk protein and with lactose intolerance) for ten adult volunteers(eight males and two females), plaque pH change was measured with In vivo/In vitro combination technique and results were as follows. 1. All six different kinds of Korean-branded commercial infant formulas dropped the plaque pH significantly(p<0.05) and at an hour after rinse, plaque pH was not recovered in most of subjects. 2. Soy based infant formula and casein-hydrolyzated infant formula containing no casein dropped the plaque pH significantly more than milk based infant formula containing casein (p<0.05). 3. In the milk protein of infant formulas, casein had more effect on buffering the pH change of the infant formula than whey protein and casein-hydrolyzated infant formula had a reduced effect of casein. 4. In infant formulas with similar protein composition, infant formula containing sucrose dropped plaque pH more than infant formula containing lactose, but there was no significant difference (p>0.05).

• Journal of the Korean Academy of Clinical Electrophysiology
• /
• v.2 no.3
• /
• pp.65-73
• /
• 2004

In experimental method, this study was that galvanic vestibular stimulation in vestibular system influenced the excitability of spinal neuron through. H-reflex was measured by galvanic vestibular stimulation of binaural(right-negative pole and left-positive pole) at left head turning and prone position in sixteen normal subjects in their twenties age were selected. The summary of the comparison results were obtained below. 1. In the change of H reflex according to galvanic vestibular stimulation(GVS), Hmax amplitude(p<.05) increased significantly after stimulation. 2. In the change of H reflex according to galvanic vestibular stimulation(GVS), Hmax/Mmax ratio(p<.05) increased significantly after stimulation. In the conclusion, galvanic vestibular stimulation influenced the excitability of vestibulospinal tract and spinal neuron.

• Journal of Environmental Health Sciences
• /
• v.16 no.2
• /
• pp.11-20
• /
• 1990

To investigate ionic characteristics of acid rain by the succeeding rainfall. bulk precipitation was collected every each 5mm rainfall from march to october 1990 at Dae Jeon area. pH, sulfate nitrate, chloride, ammonium ion was measured and analyzed. The result was as follows: 1. The weighted average pH of rain was 5.1$\pm$ 0.72(4.15~7.6) and rain pH less than 5.5 was appeared 51.3% 2. Average ion concentrations of sulfate, nitrate, chloride and ammonium ion was 125.12 $\mu$eq/l, 62.38 $\mu$eq/l, 31.95 $\mu$eq/l, 66.6 $\mu$eq/l and rates of each anions was 57%, 28.4%, 14.6% and rate of sulfate by nitrate was 2 times. 3. There is no correlations time interval of rainfall and Ion concentration change. 4. From initial to 15mm rainfall, each ion concentrations were decreased. and average concentration of pH, SO$^{-2}_{4}$, Cl ion concentration was increased in the succeeding rainfall 5. Only sulfate ion was correlated by the simple regression analysis with pH except NO$^{-}_{3}$, Cl$^{-}$ and NH$_{4}^{+}$ Cl$^{-}$ correlation coefficient was very high at the multiple regression analysis with pH. 6. Simple & multiple correlation coefficient among anions and NH$^{+}_{4}$ was very high especially N$^{+}_{4}$ and SO$^{2-}_{4}$ at simple regression analysis and SO$^{-2}_{4}$ and NO$_{3}^{-}$, Cl$^{-}$, NH$_{4}^{-}$ at multiple regression analysis.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.05a
• /
• pp.337-338
• /
• 2013

Recent research is needed for the reduction of the pH of the recycled aggregates, recycled aggregates for alkali social problems have emerged. This was confirmed through preliminary experiments using a self-made reactor with dry ice, the possibility of reducing the pH of the recycled aggregates. The pH reduction of coarse recycled aggregates plant was made to apply the field to the middle of construction waste treatment process to reduce the pH of the plant room, and measured the pH change with time. The measurement results showed that dry ice after the reaction, the pH of the aggregate 5% reduction than untreated recycled aggregates.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.267.2-267.2
• /
• 2013

In the citrate reduction method of gold nanoparticle (AuNP) synthesis, pH of the reaction mixture can have a considerable impact on the size and size distribution of AuNPs. In this work, effects of pH variation upon the size and its distribution were examined systematically. As the initial pH was change from 5.5 to 10.5, it showed an optimal pH around 7.5. At this pH, both of the size and the size distribution showed their minimum values, which was verified by transmission electron microscopy and UV-vis spectroscopy. This occurrence of optimal pH was discussed with the results of in situ monitoring pH during the reaction of AuNP synthesis.

• Textile Coloration and Finishing
• /
• v.20 no.6
• /
• pp.51-62
• /
• 2008

The purpose of this study was to check color change depending on dyeing conditions when silk fabrics was dyed with gromwell and to investigate mordant effect when synthetic tannin was used as a mordant. First, when silk fabrics were dyed with gromwell, the change of color, brightness and chroma were examined by measuring K/S value, a, b value, L value and C value depending on dyeing condition. Second, color, brightness and chroma differences which appeared after mordanting with synthetic tannin were investigated and muti-functional mordanting effect was confirmed with dyeing fastness, antibiosis. As a result of color analysis of gromwell, it was proved that the main pigment of gromwell was shikonin. Color was red purple at pH 3 when silk fabrics were dyed with gromwell. But It became greenish and bluish as temperature rose and time passed by. And it grew reddish and yellowish as concentration level reached higher. The color became purple at pH 5 and purple blue at pH 7. Both at pH 5 and pH 7, it became greenish and yellowish, as temperature went up and time ran by. And it became reddish with concentration increasing. Brightness and chroma decreased with temperature and concentration increasing as well as time passing by. After mordanting with synthetic tannin, the color became less reddish at pH 3 and reddish-yellowish at pH 5 and pH 7. The brightness increased and the chroma decreased. At all pH, the color, the brightness and the chroma became similarly by synthetic tannin mordanting. Dyeing fastness of synthetic tannin mordanted fabric was higher than that of non-mordanted fabric. Especially, wet fastness at pH 3 improved from 1 grade before synthetic tannin mordanting to $3{\sim}4$ grade after tannin mordanting. Antibiosis was improved by gromwell dyeing and synthetic tannin mordanting.

• Journal of Korean society of Dental Hygiene
• /
• v.16 no.5
• /
• pp.783-790
• /
• 2016

Objectives: The purpose of this study is to evaluate the non-enzymatic antioxidants stabilities in dentifrices by ascorbic acid and tocopherol according to the chemical condition. Methods: For the analysis of two antioxidants, HPLC UV detector system was used. HPLC was performed using sodium sulfate, acetonitrile(ACN), methanol(MeOH) and measuring absorbance at 240-295 nm. To confirm general pH reaction of two compounds, buffer solution was prepared for the analysis. The dentifrice was titrated by pH so as to examine the change of elapsed time in dentifrice. Linearity of calibration curve of two antioxidants was measured. Results: Each compound showed good linearity at optimized wavelength as well as showing good precision. General pH reaction of two antioxidants was examined. Ascorbic acid showed the highest residue(63.23%) at pH 10 and the lowest residue(2.77%) at pH 4. Tocopherol showed the highest residue(55.70%) at pH 7 and the lowest residue(3.31%) at pH 4. As a result of changing elapsed time of antioxidants in dentifrice by pH, components were remained stably at low temperature($39.2^{\circ}F$) and pH 7. Conclusions: It is necessary to keep dentifrice including ascorbic acid and tocopherol, and non-enzymatic antioxidants at pH 7 and low temperature for improving chemical stability.

• Korean Journal of Food Science and Technology
• /
• v.20 no.4
• /
• pp.476-482
• /
• 1988

The quality characteristics of pH, total acidity, and color of Kimchi juice and organoleptic properties of taste, odor and texture were studied for their changes during Kimchi fermentation. Kimchi was prepared by salting in 15% NaCl solution for 2 hours followed by addition of other spices and fermentation at $4-35^{\circ}C$. The results of pH decrease and acidity increase suggested that Kimchi fermentation can be classified into 3 steps of initial, intermediate and final stages. The activation energyes calculated from the intermediate stage where pH decreased rapidly were 15.67Kcal/mole for pH change and 18.99Kcal/mole for acidity change. The Hunter color values of Kimchi liquid showed that it becomes a weak greenish bluecolor as the fermentation progressed. Sensory characteristics of fresh sourness taste and odor and fracturability of Kimchi were increased until pH reached approx. 4.0 and then decreased while moldy taste and odor was increased rapidly thereafter.

• Journal of Sensor Science and Technology
• /
• v.18 no.5
• /
• pp.365-371
• /
• 2009

In this study, we have fabricated a fiber-optic pH sensor which is composed of a light source, plastic optical fibers and a spectrometer. As an indicator, a phenol red is used, and a pH liquid solution is prepared by mixing of phenol red and various kinds of pH buffer solutions in these experiments. The emitting light from a light source is guided by plastic optical fibers to the pH liquid solution, and the optical characteristic of a light is changed in the pH liquid solution according to its color change. Therefore, we have measured the intensities and wavelength shifts of the modulated lights, which are changed due to the color variations of phenol red at different pH values, by using of a spectrometer for spectral analysis. Also, the relationships between the pH values of liquid solutions and the optical properties of modulated light according to the change of color of phenol red are obtained.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.22 no.1
• /
• pp.128-136
• /
• 1992

This study was undertakened to investigate the change of image characteristics on dental films according to the process of using time of processing solution in automatic processor. Base + fog density, film density and subject contrast were measured with the digital densitometer, the pH of developing and fixing solution were measured with Digital pH / ION Meter. The following results were obtained: 1. Base + fog density was increased with the process of using time of the processing solution and was over the maximum permissible base + fog density 0.25 from the 3rd day. 2. Film density was increased with the process of using time of the processing solution. 3. Subject contrast was decreased with the process of using time of the processing solution. 4. The pH of the developing solution was decreased with the process of using time, the pH of the fixing solution was increased.