• Korean journal of food and cookery science
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• v.33 no.3
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• pp.300-306
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• 2017

Purpose: This study aimed to prepare sea tangle vinegar and test its applicability as a vinegar-based functional salad dressing in terms of physicochemical properties. Methods: Sea tangle vinegar was prepared by mixing sea tangle with sugar and vinegar and fermenting the mixture at room temperature for 3 months. The resulting sea tangle vinegar was examined for its physicochemical properties and antioxidant activity with brewed vinegar and persimmon vinegar as controls. Results: The sea tangle vinegar showed significantly higher viscosity than control vinegars, and shear thinning behavior that is typical for salad dressing containing polymers. In addition, storage modulus (G′) of sea tangle vinegar was relatively high in dynamic viscosity measurement while that of control vinegars remained negligible. Together with the high soluble solids content of sea tangle vinegar, rheological behavior indicates that sea tangle vinegar had soluble polysaccharides extracted from sea tangle, consequently leading to an increase in viscosity. Titratable acidity (TA) and pH were 2.52% and 3.58, respectively, which satisfies the TA and pH requirements for microbiological safety of a salad dressing. Absorbance at 285 nm and Folin Ciocalteu's reagent method revealed that sea tangle vinegar contained antioxidative phenolic compounds. Conclusion: This study demonstrates that sea tangle vinegar could be potentially developed as a vinegar-based functional salad dressing when combined with sensory evaluation in the future.

• The Korean Journal of Ecology
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• v.22 no.1
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• pp.7-11
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• 1999

The measurement of pH in the rhizosphere soil was conducted to clarify whether the growth of pokeberry plants affect the acidity of rhizosphere soil in two environmentally contrasting area Ulsan and Chongju city. The rhizosphere pH between 5.25 and 5.33 was shown in the pokeberry stand at Mt. Boomo located at Chongju. The rhizosphere pH of pokeberry stands at Mt. Bongdae, Mt. Sinsun and Mt. Totchil was below 5.0, and did not differ with depth and distance from the main axis of root. At Mt. Bongdae, however, the pH in the rhizosphere soil was significantly changed with soil depths though that was not changed horizontally. The rhizosphere pH at top soil was lower than that at subsoil, which indicates the fact that soil acidification at Mt. Bongdae was not caused by pokeberry plants. Furthermore, the rhizosphere pH did not change with the growth of pokeberry plants. These results indicate that the hypothesis that pokeberry plants acidify local soil environment should be reconsidered.

• Journal of Electrochemical Science and Technology
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• v.8 no.1
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• pp.43-52
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• 2017

In this paper, for the first time, the electroanalytical study of Triethylenediamine, TEDA was done on a typically graphene modified carbon paste electrode (Gr/CPE) in pH=10.5 of phosphate buffer solutions (PBS). The surface morphology of the bare and modified electrodes was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electro-oxidation of TEDA was investigated at the surface of modified electrode. The results revealed that the oxidation peak current of TEDA at the surface of Gr/CPE is 2.70 times than that shown at bare-CPE. A linear calibration plot was observed in the range of 1.0 to 202.0 ppm. In this way, the detection limit was found to be 0.18 ppm. The method was then successfully applied to determination of TEDA in aqueous samples obtained from two kinds of activated carbon from the masks of war. On the other hand, density functional theory (DFT) method at B3LYP/6-311++G** level of theory and a conductor-like Polarizable Continuum Model (CPCM) was used to calculate the $pK_a$ values of TEDA. The energies of lowest unoccupied molecular orbital ($E_{LUMO}$) and highest occupied molecular orbital ($E_{HOMO}$), gap energy (${\Delta}E$) and some thermodynamic parameters such as Gibbs free energy of TEDA and its conjugate acid ($HT^+$) were calculated. The results of calculated $pK_a$ were found to be in good agreement with the experimental values.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.1-12
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• 2016

This study was carried out for the improvement of nutrition and quality of streamed bread. For this purpose, brown rice liquid starter and brown rice sourdough were made and steamed bread was made with different amounts of starter addition followed by a measurement of its physicochemical and sensory characteristics. The pH of dough and titratable acidity tended to decrease significantly according to brown rice sourdough. In addition, the titratable acidity of the control group had significant different by samples. As for the volume of dough, there was no significant difference between the control sample and each sample, but after 15 minutes of fermentation, the volume increased the most in the control sample, with sample D having the least volume. As for volume and specific volume of steamed bread, sample B had the largest at 3.34 and each sample had significant differences based on fermentation time. As for diameter, sample B was the largest at 88.11 and sample D was the smallest at 79.04, with significant differences among samples. As for height of steamed bread, the control group was the highest at 42.91 and sample D was the lowest at41.87, with significant differences among samples. As for the cross-section structure of steamed bread, the porous of sample B, which had the largest volume and specific volume, was the largest with uniform texture and even distribution. L value tended to be higher in the added sampleroups than in the control sample. a value increased as brown rice sourdough increased, and b value was lower when volume and specific volume of the steamed bread increased, which showed a similar trend with that a L value. As for hardness, viscosity, and chewing capacity, sample D was the highest and sample B was the lowest, with significant differences among samples. As a result of measurement of overall preference, sample B had the highest preference with the highest preference in flavor, taste, appearance and texture, and D had the lowest preference with the lowest preference in taste, appearance and texture, with significant differences among samples.

• Journal of Wetlands Research
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• v.22 no.4
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• pp.312-320
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• 2020

Various LIDs with natural water circulation function are applied to reduce urban environmental problems and environmental impact of development projects. However, excessive Infiltration and evaporation of LID facilities dry the LID internal soil, thus reducing plant and microbial activity and reducing environmental re duction ability. The purpose of this study was to develop a real-time measurement system with complex sensors to derive the management plan of LID facilities. The test of measurable sensors and Internet of Things (IoT) application was conducted in artificial wetlands shaped in acrylic boxes. The applied sensors were intended to be built at a low cost considering the distributed LID and were based on Arduino and Raspberry Pi, which are relatively inexpensive and commercialized. In addition, the goal was to develop complex sensor measurements to analyze the current state o f LID facilities and the effects of maintenance and abnormal weather conditions. Sensors are required to measure wind direction, wind speed, rainfall, carbon dioxide, Micro-dust, temperature and humidity, acidity, and location information in real time. Data collection devices, storage server programs, and operation programs for PC and mobile devices were developed to collect, transmit and check the results of measured data from applied sensors. The measurements obtained through each sensor are passed through the Wifi module to the management server and stored on the database server in real time. Analysis of the four-month measurement result values conducted in this study confirmed the stability and applicability of ICT technology application to LID facilities. Real-time measured values are found to be able to utilize big data to evaluate the functions of LID facilities and derive maintenance measures.

• Korean Journal of Human Ecology
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• v.6 no.2
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• pp.57-65
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• 2003

To investigate quality characteristics of kimchi prepared for the winter around Chonnam area, home made kimchi samples collected from 22 area, and they were stored at -1${\pm}$1$^{\circ}C$. The results were as follows : The pH and acidity of kimchi samples were 4.75 and 0.84%. respectively. Salt concentration was 3.50% and in Redox potential measurement, Eh value was -134.08mV. Ascorbic acid and reducing sugar contents were 10.l8mg% and 13.25mg%, respectively, In color measurement, L value was 52.29 and a and b values were 19.68 and 27.69, respectively. Total viable count was 5.5${\times}$10$\^$6/ and lactic acid bacteria count and yeast were 4.6${\times}$10$\^$5/ and 8.8${\times}$10$\^$5/. respectively. Properties of hardness of kimchi measured instrumentally was 9.26kgf. Alcohol insoluble solids(AIS) content was 5.53% and hot water soluble pectin(HWSP) content and sodium hexametaphosphate soluble pectin(NaSP) content were 17.35% and 29.65%, respectively, also hydrochloric acid soluble pectin(HClSP) content was 53.0%.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.113-125
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• 2007

To know the differences in ionic compositions in rain and snow as well as snow influence on the chemical characteristics of winter precipitation, precipitation samples were collected by the wet-only automatic precipitation sample, in winter(November-February) in the Iksan located in the northwest of Chonbuk from 1995 to 2000. The samples were analyzed for concentrations of water-soluble ion species, in addition to pH and electrical conductivity. The mean pH of winter precipitation was 4.72. According to the type of winter precipitation, the mean pH of rain was 4.67 and lower than 5.05 in snow. The frequencies of pH below 5.0 in rain were about 73%, while those in snow were about 30%. Snow contained 3 times higher concentrations of sea salt ion components originated from seawater than did rain in winter, mainly $Cl^-,\;Na^+$, and $Mg^{2+}$. Neglecting sea salt ion components, $nss-SO_4^{2-}$ and $NO_3^-$ were important anions and $NH_4^+$ and $nss-Ca^{2+}$ were important cations in both of rain and snow. Concentrations of $nss-SO_4^{2-}$ was 1.3 times higher in rain than in snow, while those of $nss-Ca^{2+}$ and $NO_3^-$ were 1.5 and 1.3 times higher in snow, respectively. The mean equivalent concentration ratio of $nss-SO_4^{2-}/NO_3^-$ in winter precipitation were 2.4, which implied that the relative contribution of sulfuric and nitric acids to the precipitation acidity was 71% and 29%, respectively. The ratio in rain was 2.7 and higher than 1.5 in snow. These results suggest that the difference of $NO_3^-$ in rain and snow could be due to the more effective scavenging of $HNO_3$ vapor than particulate sulfate or nitrate by snow. The lower ratio in snow than rain is consistent with the measurement results of foreign other investigators and with scavenging theory of atmospheric aerosols. Although substantial $nss-SO_4^{2-}$ and $NO_3^-$ were observed in both of rain and snow, the corresponding presence of $NH_4^+,\;nss-Ca^{2+},\;nss-K^+$ suggested the significant neutralization of rain and snow. Differences in chemical composition of non-sea salt ions and neutralizing rapacity of $NH_4^+,\;nss-Ca^{2+}$, and $nss-K^+$ between rain and snow could explain the acidity difference of rain and snow. Snow affected that winter precipitation could be less acidic due to its higher neutralizing rapacity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.907-914
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• 1996

To enhance the shelf-life and quality of baechu kimchi, the effects of CSP(crab shell powder) addition to kimchi was investigated. Overall qualities were deteriorated by fish odor, chewiness of particles, sharp pH increase at the early fermentation stage; therefore in order to solve these problems kimchi fermentation was carried out with kimchi containing 1, 3, 5% CSPB for salted baech weight at $10^{\circ}C$ for 300ays. Quality of kimchi was evalutated by the measurement of pH, acidity, colour L, a, and b value, the number of microbe and lactic acid bacteria, texture. Ten highly trained panelists were involved in the sensory evaluation. During the entire fermentation periods, pH, hardness, colour L, a and b value, the number of lactic acid bacteria of kimchi with CSPB were higher than those of control, but acidity was lower. Sensory quality showed that sour taste of control at 15-day fermentation was already strong. However, sour taste, crispness taste, and overall taste of kimchi with CSPB untill 20-day fermentation were good. Especially, overall taste of kimchi containing 3% CSPB at 30-day fermentation was good, but that of kimchi containing 5% showed fish odor from the early periods of fermentation.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.522-530
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• 2007

This experiment was carried out to measure the content of lactoferrin, IgA, $IgG_1,\;IgG_2$, in Holstein colostrum, and to test the effect of it's colostrum on the antibacterial activity to pathogenic bacteria and the growth stimulation of lactic acid bacteria. Colostrum was collected at the first, second, and third day after parturition in summer and winter season. The levels of lactoferrin, IgA, $IgG_1,\;and\;IgG_2$ in Holstein cow colostrum were 0.30 mg/mL, 0.37 mg/mL, 4.00 mg/mL, 0.37 mg/mL, respectively, on the first day of the summer season whereas they were 1.16 mg/mL, 2.60 mg/mL, 13.35 mg/mL, 1.30 mg/mL on the first day of the winter season, postpartum. Heat treated ($65^{\circ}C$ for 30 min) or non-treated colostrum showed antibacterial activity toward Escherichia coli. The growth of commercial mixed strains (Bifidobacterium longum, Lactobacillus acidophilus, Streptococcus themophilus), L. acidophilus, L. casei, L. bulgaricus, and L. lactis subsp. cremoris were improved in first, second and third day colostrum compared to normal milk. Commercial miked strains (B. longum, L. acidophilus S. themophilus) lowered the pH to 4.97-5.22 and 4.89 while increasing the titratable acidity to 0.75-0.88% and 0.70% in colostrum and normal milk, respectively. However, L. casei, L. bulgaricus, L. lactis subsp. cremoris lowered the pH to 5.96-6.47 and 6.5-6.8 while increasing the titratable acidity to 0.29-0.48% and 0.20-0.25% in colostrum and normal milk, respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.6
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• pp.1274-1279
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• 2011

The purpose of this paper is to present the manufacturing defect and damage pattern of a 3 phase 22.9/3.3kV oil immersed transformer, as well as to present an objective basis for the prevention of a similar accident and to secure data for the settlement of PL related disputes. It was found that in order to prevent the occurrence of accidents to transformers, insulating oil analysis, thermal image measurement, and corona discharge diagnosis, etc., were performed by establishing relevant regulation. The result of analysis performed on the external appearance of a transformer to which an accident occurred, the internal insulation resistance and protection system, etc., showed that most of the analysis items were judged to be acceptable. However, it was found that the insulation characteristics between the primary winding and the enclosure, those between the ground and the secondary winding, and those between the primary and secondary windings were inappropriate due to an insulating oil leak caused by damage to the pressure relief valve. From the analysis of the acidity values measured over the past 5 years, it is thought that an increase in carbon dioxide (CO2) caused an increase in the temperature inside the transformer and the increase in the ethylene gas increased the possibility of ignition. Even though 17 years have passed since the transformer was installed, it was found that the system's design, manufacture, maintenance and management have been performed well and the insulating paper was in good condition, and that there was no trace of public access or vandalism. However, in the case of transformers to which accidents have occurred, a melted area between the upper and the intermediate bobbins of the W-phase secondary winding as well as between its intermediate and lower bobbins. It can be seen that a V-pattern was formed at the carbonized area of the transformer and that the depth of the carbonization is deeper at the upper side than the lower side. In addition, it was found that physical bending and deformation occurred inside the secondary winding due to non-uniform pressure while performing transformer winding work. Therefore, since it is obvious that the accident occurred due to a manufacturing defect (winding work defect), it is thought that the manufacturer of the transformer is responsible for the accident and that it is lawful for the manufacture to investigate and prove the concrete cause of the accident according to the Product Liability Law (PLL).