• Archives of Pharmacal Research
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• v.4 no.2
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• pp.109-115
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• 1981

In the present investigation, an attempt has been made to apply the methods of classical chemical kinetics to the hydrolytic reaction of pipethanate hydrochloride. By successively keeping all but one variable essentially constant, it has been possible to resolve the overall effect of the individual contributing factors. Since nearly all commercial pipethanate preparations are formulated with antacid, studies were made at several constant hydrogen ion concentration ranging pH 0.4 to 7.5. Rate measurement was also carried out in temperature ranging from $25^{\circ}C$ to $60^{\circ}C$. The hydrolysis of pipethanate is found to be of first order with respect to pipeethanate concentration over an experimental range of hydrogen ion concentration (pH 0407.5). The apparent activation energy(Ea) at pH 7.5 is 18.30 Kcal/mole and the frequency factor is $1.1408 {\times}10^{9}sec^{-1}$. The rate of the hydrolysis has a minimum at pH 2.5-3.5. In this region the half-life of pipethanate was about15.3 days at $60^{\circ}C$. The catalytic effect of water was found to be $K_{H_2O}$ = $3.16{\times}10^{-5}min^{-1}$ at $60^{\circ}C$. The catalytic constants of the hydroxyl ions and hydrogen ions at $60^{\circ}C$ were also found to be $K_{OH}$ = $4.5519{\times}10^{-5}min^{-1}$ and $K_{H}+$ = $1.1568{\times}10^{-2}min^{-1}$, respectively. This reaction appears to be primarily base catalyzed hydrolysis and pipethanate is relatively reluctant toward acid catalyzed hydrolysis. A positive primary salt effect was noted in the solution of phpethanate at pH 7.5 and at $60^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.990-997
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• 1995

Effect of preparation method on Yulmoo kimchi(watery kimchi prepared with Yulmoo, leaf radish) fermentation was investigated by measuring physicochemical, microbiological and sensory properties for 20 days. Yulmoo kimchi was fermented at 4$^{\circ}C$ after keeping at room temperature(27$\pm$0.5$^{\circ}C$) for 8 hours. Four types(A, B, C, D) of Yulmoo kimchi were prepared. Sample A was made without wheat flour paste and red pepper powder and sample B was made with wheat flour paste. Sample C was made with red pepper powder, and sample D was made with wheat flour paste and red pepper powder. pH was slowly lowered and stabled after 10 days in all samples. Total acid content increased in all samples. Reducing sugar content initially increased and decreased thereafter. Especially, reducing sugar content of sample B increased in the early stage of fermentation and maintained initial reducing sugar content after 20 days. Total vitamin C content reduced during fermentation in all samples. Especially initial total vitamin C content of sample D increased more than those of other samples relatiely. Lightness and yellowness showed no difference, but on the other hand redness increased gradually in all samples. The number of lactic acid bactgeria reached maximum value in 10~13 days with the total cell numbers and gradually decreased thereafter in all samples. The number of lactic acid bacteria and total cell number of sample D was much more than those of any other samples. As a result of the sensory evaluation, Yulmoo kimchi showed significant difference in all characteristics. Sample D showed the highest scores in all characteristics before 10 days of fermentation. However, after 10 days sample B showed the highest scores.

• Korean journal of food and cookery science
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• v.5 no.1
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• pp.69-74
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• 1989

Trans fatty acids are formed during refining process of vegetable oils (deodorization), hydrogenation, the high temperature treatment of oils and rancidity. Trans fatty acids contents were measured in vegetable oils added to tuna, oyster and mussel Can by Glass Capillary Gas Chromatography. Also Acid Values, Peroxide Values, iodine Values and Saponification Values of vegetable oils added to Can were determined. The results were as follows; 1. Among vegetable oils added to Can, trans fatty acids isomer of cotton seed oil were mostly t,c-18:2 and t,c,c-18:3. 2. Total average contents of trans fatty acids of soybean oil added to tuna Can (Ab) were shown the highest values among tuna (Aa, Ab), oyster, mussel (Cb) Cans. 3. All of oils added to Can had been keeping safe quality during 1 year or more with low Acid and Peroxide Values.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.52-57
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• 1999

Korea Earthquake Monitoring System(KEMS) in the Korea Institute of Geology Mining and Materials(KIGAM) as detected more than 1000 events since the end of 1998. But not all events are interpreted as earthquakes because many events are concentrated on daytime. It strongly implies that in addition to earthquake these events include artificial effects such as industrial blasting. Before the determination of eathquake charactertistics in the korean peninsula it is necessary to discriminate the detected events as earthquakes or artificial events. For the discriminant study KIGAM and SMU(Southern Methodist University) installed a triangular four-element 1-km aperture seismo-acoustic array at Chul-Won area northeast of Seoul Korea. Each array element includes a GS-13 seismometer in the bottom of borehole and a Validyne DP250-14 microbarometer sensor mounted inside of the borehole 1,2 meter deep connected to a 11 arm radial array of 10m porous soaker hoses. This array introduce the use of 2.4-GHz radios for inter-array self-contained solar-charged power system and GPS time-keeping system. A 24-bit digital data acquisition system performs 40 SPS in the infrasound and seismometer data. Velocity and direction of wind and temperature are also measured at hub site and included to the data stresam. This seismo-acoustic array will be used to identify and locate associated with industrial blasting and these identified and located events will be applied to form a ground truth database useful to assist the other development of discriminant studies.

• Journal of Korean Society of Archives and Records Management
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• v.3 no.2
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• pp.143-155
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• 2003

As archives, photograph is the evident records of historical facts and experiences. Thus, it is worth preserving. Unlike other documents silver halide photographic films and prints are quite sensitive to environmental factors such as light, temperature and humidity, which demands careful treatment in preservation. This study was carried out to select popular photographic films and papers on the market, to examine their photographic speeds (or sensitivities) and to compare and analyze their preservative features after keeping them some time in a weather-o-meter. Consequently, B/W materials were superior to color ones in preservation. And films were better than papers in the same manner. But we were not able to observe remarkable differences among material's manufacturers.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.1-8
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• 2021

The performance of hidden camera cameras is improving day by day due to miniaturization and advanced technology integration according to the speed of technological development of smartphones. As this external networking computing environment is advanced and diversified, exposure to hidden cameras in addition to general safety cameras is also increasing. On the other hand, the technology for detecting and preventing hidden cameras is not keeping up with the development and speed of these hidden cameras. Therefore, in this study, the heat of the hidden camera was detected using infrared thermal detection technology based on general image and thermal image synthesis technology, and the reflectance of each wavelength according to the difference in ambient temperature was analyzed to reduce the false positive rate.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.1-8
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• 2021

Currently, lithium-ion batteries are mainly used in energy storage equipment products including automobiles. This can be exposed to dangerous situations such as explosions in the event of incorrect battery management conditions that are overcharged or left in high temperature conditions. It also causes a situation battery cannot be used when it has been over discharged. Therefore, a system that manages the state of the battery is required. The battery management system aims to obtain optimum battery efficiency by accurately recognizing the state of the battery and keeping the voltage of each cell constant. In this paper, we develop a lithium-iron phosphate battery that has higher safety than a general lithium-ion battery. Then, in order to manage this, we try to develop the algorithm of the BMS module based on the Bluetooth communication using the MATLAB-SIMULINK.

• Applied Chemistry for Engineering
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• v.22 no.3
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• pp.243-248
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• 2011

Pt deposited porous carbon nanofibers was prepared as a highly sensitive material of hydrogen gas sensor operating at room temperature. Nanofibers was obtained by electrospinning method using polyacrylonitrile as a carbon precursor and then thermally treated for carbon nanofibers. Chemical activation of carbon nanofibers was carried out to enlarge specific surface area up to $2093m^2/g$. Sputtered Pt layer was uniformly distributed keeping the original shape of carbon nanofibers. The hydrogen gas sensing time and sensitivity were improved based on effects of high specific surface area, micropore structure and deposited Pt catalyst.

• Animal Bioscience
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• v.37 no.8
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• pp.1440-1451
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• 2024

Objective: This study aimed to develop and evaluate the effectiveness of a water-soluble microencapsulation method for probiotic strains using gum Arabic (GA) and skim milk (SKM) over a three-month storage period following processing. Methods: Four strains of Pediococcus acidilactici (BYF26, BYF20, BF9, and BF14) that were typical lactic acid bacteria (LAB) isolated from the chicken gut were mixed with different ratios of GA and SKM as coating agents before spray drying at an inlet temperature 140℃. After processing, the survivability and probiotic qualities of the strains were assessed from two weeks to three months of storage at varied temperatures, and de-encapsulation was performed to confirm the soluble properties. Finally, the antibacterial activity of the probiotics was assessed under simulated gastrointestinal conditions. Results: As shown by scanning electron microscopy, spray-drying produced a spherical, white-yellow powder. The encapsulation efficacy (percent) was greatest for a coating containing a combination of 30% gum Arabic: 30% skim milk (w/v) (GA:SKM30) compared to lower concentrations of the two ingredients (p<0.05). Coating with GA:SKM30 (w/v) significantly enhanced (p<0.05) BYF26 survival under simulated gastrointestinal conditions (pH 2.5 to 3) and maintained higher survival rates compared to non-encapsulated cells under an artificial intestinal juices condition of pH 6. De-encapsulation tests indicated that the encapsulated powder dissolved in water while keeping viable cell counts within the effective range of 10⁶ for 6 hours. In addition, following three months storage at 4℃, microencapsulation of BYF26 in GA:SKM30 maintained both the number of viable cells (p<0.05) and the preparation's antibacterial efficacy against pathogenic bacteria, specifically strains of Salmonella. Conclusion: Our prototype water-soluble probiotic microencapsulation GA:SKM30 effectively maintains LAB characteristics and survival rates, demonstrating its potential for use in preserving probiotic strains that can be used in chickens and potentially in other livestock.

• 한국유가공학회:학술대회논문집
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• 2002.11a
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• pp.23-40
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• 2002

This study was conducted to investigate the quality changes of the UHT(ultra-high temperature), LTLT(law temperature long time) and HTST(high temperature short time) treated milk samples by storage conditions for 6 months from August 2000 to February 2001. The UHT treated milk samples collected from 3 plants(A, B and C) were stored at l0$^{\circ}$C and room temperature(dark and light exposure) for 6 months, and the LTLT and HTST treated milk samples(D and E) were also stored for 30 days. The UHT pasteurized milk of A, B and C plant was treated at 130$^{\circ}$C for 2-3s, 133$^{\circ}$C for 2-3s and 135$^{\circ}$C for 4s, respectively. The UHT sterilized milk of A and B plant was treated at 140$^{\circ}$C for 2-3s and 145$^{\circ}$C for 3-4s, respectively. The LTLT milk of D plant was treated at 63$^{\circ}$C for 30 mins, and the HTST milk of E plant was treated at 72$^{\circ}$C for 15s. All of the raw milk samples collected from storage tank in 5 milk plants were showed less than 4.0 X 10$^5$cfu/ml in standard plate count, and normal level in acidity, specific gravity, and component of milk. Preservatives, antibiotics, sulfonamides and available chloride were not detected in both raw and heat treated milk samples obtained from 5 plants. One(10%) of 10 UHT pasteurized milk samples obtained from B plant and 2 (20%) of 10 from C were not detected in bacterial count after storage at 37$^{\circ}$C for 14 days, but all of the 10 milk samples from A were detected. No coliforms were detected in all samples tested. No bacteria were also detected in carton, polyethylene and tetra packs collected from the milk plants. A total of 300 UHT pasteurized milk samples collected from 3 plants were stored at room(3$^{\circ}$C ${\sim}$ 30$^{\circ}$C) for 3 and 6 months, 11.3%(34/300) were kept normal in sensory test, and 10.7%(32/300)were negative in bacterial count. The UHT pasteurized milk from A deteriorated faster than the UHT pasteurized milk from B and C. The bacterial counts in the UHT pasteurized milk samples stored at 10$^{\circ}$C were kept less than standard limit(2 ${\times}$ 10$^4$ cfu/ml) of bacteria for 5 days, and bacterial counts in some milk samples were a slightly increased more than the standard limit as time elapsed for 6 months. When the milk samples were stored at room(3$^{\circ}$C ${\sim}$ 30$^{\circ}$C), the bacterial counts in most of the milk samples from A plant were more than the standard limit after 3 days of storage, but in the 20%${\sim}$30%(4${\sim}$6/20) of the milk samples from B and C were less than the standard limit after 6 months of storage. The bacterial counts in the LTLT and HTST pasteurized milk samples were about 4.0 ${\times}$ 10$^3$ and 1.5 ${\times}$ 101CFU/ml at the production day, respectively. The bacterial counts in the samples were rapidly increased to more than 10$^7$ CFU/ml at room temperature(12$^{\circ}$C ${\sim}$ 30$^{\circ}$C) for 3 days, but were kept less than 2 ${\times}$ 10$^3$ CFU/ml at refrigerator(l0$^{\circ}$C) for 7 days of storage. The sensory quality and acidity of pasteurized milk were gradually changed in proportion to bacterial counts during storage at room temperature and 10$^{\circ}$C for 30 days or 6 months. The standard limit of bacteria in whole market milk was more sensitive than those of sensory and chemical test as standards to determine the unaccepted milk. No significant correlation was found in keeping quality of the milk samples between dark and light exposure at room for 30 days or 6 months. The compositions of fat, solids not fat, protein and lactose in milk samples were not significantly changed according to the storage conditions and time for 30 days or 6 months. The UHT sterilized milk samples(A plant ; 20 samples, B plant ; 110 samples) collected from 2 plants were not changed sensory, chemical and microbiological quality by storage conditions for 6 months, but only one sample from B was detected the bacteria after 60 days of storage. The shelflife of UHT pasteurized milk in this study was a little longer than that reported by previous surveys. Although the shelflife of UHT pasteurized milk made a significant difference among three milk plants, the results indicated that some UHT pasteurized milk in polyethylene coated carton pack could be stored at room temperature for 6 months. The LTLT and HTST pasteurized milk should be sanitarily handled, kept and transported under refrigerated condition(below 7$^{\circ}$C) in order to supply wholesome milk to consumers.