• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.969-973
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• 1999

In this work, we studied the degree of hydrolysis of ion exchanger in $NH_4OH$ solution and sorption characteristics of $NH_3$ by potentiometric titration curves with using carboxylic acid ion exchanger Fiban K-4. We knew that the theoretical pH values agreed with the experimental pH values on the $NH_4OH$ concentrations in various concentrations of supporting electrolyte $(NH_4)_2SO_4$. The sorption values of $NH_3$ using the ion exchanger can be calculated from equivalent sorption curves for various pH. Also, the degree of hydrolysis increased with decreasing concentration of supporting electrolyte and pH. In order to obtain the mono ion form below 0.01 M as the decreasing concentration of supporting electrolyte, the pH values should be increased. From these results, therefore, the concentrations of supporting electrolyte and pH values were determined.

• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.325-330
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• 1996

Foaming capacity (FC) and stability (FS) of protein recovered from red crab (Chitinonecetes opilio) processing in water and soybean protein isolate were determined at pH 2.0~10.0 in water and NaCl solution. The FC values for both proteins showed the lowest values at the isoelectric point (pH 4.0) and increased nth an increase in pH above the isoelectric point. FC of RCP was higher than that of SPI at pH 10.0 in water and both NaCl solutions. FC of SPI increased with an increase in NaCl concentration at pH 4.0 and 6.0, but FC of RCP was not affected. The highest FS values for both proteins were obtained at pH 4.0 in water. At pH 2.0, FC of RCP decreased with NaCl concentration increase, but FS increased. NaCl concentration had little effect on FS of RCP at pH 4.0 and 6.0, but the FS decreased at pH 10.0. FS of SPI was similar to that of RCP at pH 2.0 and increased with NaCl concentration Increase from 0.1 to 0.5M NaCl at pH 10.0.

• Journal of the Korean Geographical Society
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• v.38 no.1
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• pp.1-15
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• 2003

The basic data of groundwater quality such as water temperature, pH and electric conductivity were collected for 6 months from July to December 2000 in Yongnup. The results are as follows; the values of groundwater quality at the unsaturated points were beyond the distribution range when compared with those at fully saturated points. Temperature of groundwater in Yongnup increased with the rising of watertable. The values of pH were usually measured between 5.0 and 6.0, but sometimes those of lower than 4.0 were indicated. The value measured at unvegetated ground was higher than that at covered area. Also, the electric conductivity increased with the rising of watertable. The values of water quality between groundwater and surface water were quite different from each other and varied with seasonal change. The measured values of pH and electric conductivity had a proportional relationship.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.2
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• pp.179-187
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• 1996

Sampling of precipitation occurred at Woongchon in Choongnam from the period between May 1994 and April 1995 was made, and analysis on the data was carried out on observed pH values of the precipitations. It was found that weighted mean pH values were .sim. 4.8 and that acid rain occurred at the site of the Yellow Sea's coastal area. The results agree well with the earlier observations made at other sites of a background monitoring network. The annual values observed at the background monitoring sites were too low in comparison with the mean pH values (5.3 .sim. 5.9) obtained from urban stations of the Ministry of Environment. It was observed that values of pH in rain water often changed with time during the event of precipitation, and the low values usually depended on an airflow and a cyclone that originated in the source region.

• Food Science of Animal Resources
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• v.39 no.4
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• pp.541-554
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• 2019

Processed cheeses (PCs) were made under varying cooking pH values (5.3, 5.4, 5.5, and 5.6) using a processed cheese cooker. Along with emulsifying salts (2.5%), distilled water, NaCl (2%) and a colouring agent under these cooking pH values, the PC samples made with either 100% fresh curd and rennet casein coded processed cheese control ($PC_C$) as control or ~70% fresh curd-~30% traditional village cheese coded processed cheese with village cheese ($PC_V$). The main aim of this study was to determine the effect of the varying cooking pH values on the textural properties for the PCv samples compared with the control sample during 90 days of storage. Chemical and textural properties of all PC samples were investigated over time. The chemical compositions of the PC samples (dry matter and ash) increased at d 90 of storage significantly, due to 1-d ripening of all PC samples at ambient temperature in terms of the manufacturing protocol of the cheese. The textural properties of the PC samples were altered by the varying cooking pH values. It may propose that the interactions of the proteins at the cooking pH values during processing and biochemical mechanisms in the cheese systems could likely affect the texture of the PC samples over time. Hardness, gumminess and chewiness values of all PC samples also increased over time (p<0.05). This study is also to give some knowledge on the design of PC manufacture to cheese makers, and a marketing opportunity to local cheese makers who individually make a traditional village cheese in Turkey.

• Korean journal of food and cookery science
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• v.4 no.2
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• pp.1-9
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• 1988

This study was carried out in order to study the foaming properties of mungbean protein. Mungbean protein isolate was tested for the purpose of finding out the effect of pH, addition of sucrose on foaming properties. The results were summarized as follows: 1. Foam expansion values were generally depen. dent on protein concentration to 3% protein suspension. From 1% to 3% suspension, foam expansion values increased. However over 3% suspension, the values decreased. In 1% mungbean protein suspension, the foam expansion value of suspension at pH 4.5 was greater than that of at pH9. In 3%, 5%, and 10% suspensiona the foam expansion values of suspension at pH 7 was the lowest. Foam expansion value significantly decreased by the addition of sucrose. 2. The foam stability appeared the greatest value as protein concentration increased. It appeared the greatest value at pH 4.5. When sucrose was added, the foam stability increased. The more sucrose was added, the better foam stability was.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1510-1518
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• 2008

Results of intrinsic and extrinsic fluorescence studies on choline oxidase revealed that the enzyme at high alkaline pH values has more accessible hydrophobic patches relative to acidic pH. Fluorescence quenching studies with acrylamide confirm these changes. The quenching constants were also determined at different pH(s) by using the Stern-Volmer equation. CD studies showed that at higher pH a transition from $\alpha$-helix to $\beta$- structure was appeared while at lower pH the content of $\alpha$-helix structure was increased. Furthermore, analysis of the spectral data using chemometric method gave evidence for existence of intermediate components at very high pH(s). Results of thermal denaturation evaluated that the enzyme has the most instability at higher pH(s). Altogether low and high pH values caused significant alteration on secondary and tertiary structures of choline oxidase via inducing of an intermediate.

• Journal of Life Science
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• v.10 no.2
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• pp.210-217
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• 2000

A kinetic profile of the catalytic domain of stromelysin-1 (SCD) using the fluorescent peptide substrate has been determined by the stopped-flow technique. The pH profile has a pH optimum of about 5.5 with an extended shoulder above pH 7. Three pKa values, 5.0, 5.7, and 9.8 are found for the free enzyme state and two pH independent Kcat/Km values of 4.1$\times$104 M-1 s-1 and 1.4$\times$104 M-1 s-1 at low and high pH, respectively. The profile is quite different in shape with other MMP family which has been reported, having broad pH optimum with two pKa values. The substrate specificity of SCD towards fluorescent heptapeptide substrates has been also examined by thin layer chromatography. The cleavage sites of the substrates have been identified using reverse-phase HPLC method.SCD cleaves Dns-PLA↓L↓WAR and Dns-PLA↓L↓FAR at two positions. However, the Dns-PLA↓LRAR, Dns-PLE↓LFAR, adn Dns-PLSar↓LFAR are cleaved exclusively at one bond. The double cleavages of Dns-PLALWAR and Dns-PLALFAR by SCD are in marked contrast to the close structurally related matrilysin. A notable feature of SCD catalysis agrees with the structural data that the S1' pocket of SCD is deeper than that of matriysin. The differences observed between SCD and matrilysin may form the basis of understanding the structural relationships and substrate specificities of the MMP family in vivo.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.42.1-42.9
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• 2020

Objective: This study aimed to examine the physical properties (pH and flow) of 2 novel bioceramic sealers. Materials and Methods: The tested sealers were a calcium hydroxide sealer (Sealapex) and 2 bioceramic sealers (BioRoot RCS and TotalFill BC Sealer). Flow measurements were conducted according to ISO 6876/2012, with a press method of 0.05 mL of sealer. The pH of fresh samples was tested immediately after manipulation, while set samples were stored for 3 times the recommended setting time. The predetermined time intervals ranged from 3 minutes to 24 hours for fresh samples and from 10 minutes to 7 days and 4 weeks for the set samples. Analysis of variance was performed, with p = 0.05 considered indicating significance. Results: The mean flow values were 26.99 mm for BioRoot, 28.19 for Sealapex, and 30.8 mm for TotalFill BC Sealer, satisfying the ISO standard. In the set samples, BioRoot RCS had higher pH values at 24 hours to 1 week after immersion in distilled water. At 2 weeks, both bioceramic sealers had similar pH values, greater than that of Sealapex. In the fresh samples, the bioceramic sealers had significantly higher initial pH values than Sealapex (p < 0.05). At 24 hours post-immersion, all sealers showed an alkaline pH, with the highest pH observed for TotalFill. Conclusions: The TotalFill BC Sealer demonstrated the highest flow. The bioceramic sealers initially presented higher alkaline activity than the polymeric calcium hydroxide sealer. However, at 3 and 4 weeks post-immersion, all sealers had similar pH values.

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.397-401
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• 2001

Blood gas values such as pO$_2$ were studied in common marmosets, crab-eating macaques and Japanese macaques, rhesus macaques and celebes macaque reared in Korea. Blood pH and blood gas values were evaluated in both arterial and venous blood. pH, p$CO_2$, and pO$_2$, of arterial blood in common marmosets were measured as 7.4$\pm$0.1, 29.2$\pm$3.6 mmHg and 81.5$\pm$8.9 mmHg, respectively. Corresponding values in one crab-eating macaque were 7.3, 41.3 mmHg and 46.5 mmHg, respectively. In case of venous blood, pH, p$CO_2$, and pO$_2$, in common marmosets were observed as 7.2$\pm$0.2, 64.9$\pm$18.3 mmHg and 23.5$\pm$5.4 mmHg, respectively. On the while, pH, p$CO_2$, and pO$_2$, of venous blood in crab-eating macaques showed 7.2$\pm$0.2, 49.9$\pm$8.0 mmHg and 38.3$\pm$8.8 mmHg, respectively. Venous pH, p$CO_2$, and pO$_2$, in Japanese macaques were 7.1$\pm$0.2, 56.4$\pm$5.3 mmHg and 40.1$\pm$9.3 mmHg, respectively. Those values in one rhesus macaque were 7.2, 61.1 mmHg and 24.9 mmHg, and in celebes macaque were 7.1, 54.3 mmHg and 31.8 mmHg, respectively.