• Title/Summary/Keyword: pH measurement test

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Antibacterial Activity against Pathogenic Bacteria of Lactiplantibacillus argentratensis Isolated from Blueberries (블루베리로부터 분리된 Lactiplantibacillus argentratensis의 병원성균에 대한 항균활성)

  • Natsag Lkhagvasuren;Gil-Ha Kim;Batchimeg Namshir;Woan Sub Kim
    • Journal of Dairy Science and Biotechnology
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    • v.41 no.4
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    • pp.191-202
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    • 2023
  • In this study, lactic acid bacteria (LAB) was isolated from blueberries. The isolated LAB were rod-shaped and gram-positive, as shown using gram staining. In addition, the identified bacteria showed high homology to Lactiplantibacillus argentoratensis. The culture supernatant was isolated from L. argentoratensis and its antibacterial activity against the pathogenic bacteria Salmonella and Escherichia was analyzed. Culture supernatants of L. argentoratensis significantly inhibited the growth of Salmonella. Enteritidis NCCP 16947, Salmonella Typhimurium NCCP 16960, and Salmonella. Thompson NCCP 11704. Interestingly, the higher the concentration of the culture supernatant, the more significant was the antibacterial activity. Additionally, the culture supernatant of L. argentoratensis showed significant antibacterial activity against Escherichia strains. To determine whether the antibacterial substance is stable to heat and pH, the LAB culture supernatant was heat-treated under 65℃ for 30 min, 75℃ for 15 min, 85℃ for 10 min, and 100℃ for 5 min. Measurement of antibacterial activity against pathogenic strains by adding 5% of heat-treated culture medium showed the same antibacterial activity as before heat treatment. However, in a test where the pH of the culture supernatant was adjusted to 7.0 from 3.73, no antibacterial activity was observed.

Macro Mineral Responses to Caffeine in Serum and Urine of Healthy Young Females(I) -Na, K, Ca, P, Mg- (Caffeine 섭취에 따른 성인 여자의 혈액과 소변중 다량 무기질 함량 변화에 관한 연구(I) -Na, K, Ca, P, Mg-)

  • 임성아
    • Journal of Nutrition and Health
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    • v.26 no.9
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    • pp.1118-1128
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    • 1993
  • This study was undertaken to investigate the acute effect of caffeine consumption on the change of mineral concentration in serum and urinary mineral excretion in healthy young females. On two separate mornings at one week intervals, each subject drank a coffee which contained no caffeine and 3mg/kg body weight caffeine. To obviate dietary effects on mineral concentration in serum and urine, each subject fasted at least ten hours before consuming the test beverage. At one, two, three and four hours, serum and urine production collected seperately for measurement of sodium, potassium, calcium, phosphorus and magnesium concentration. The results were as following : 1) Mean age of subjects was 20.6$\pm$0.32, Mean body mass index of subjects was 21.64$\pm$0.89, which was within $\pm$10% of ideal body weight. 2) Total urine volume of caffein groups for 4 hour after caffeine consumption was higher than that of decaffeine one, but urine pH was unchanged after caffeine consumption. Total urinary four hour excretion of creatinine was not affected by caffeine consumption and creatinine clearance also was not different from the control value. 3) In serum, mean three hour content of sodium(p<0.01) and phosphorus was higher in the subject given the caffeine. Mean serum magnesium and calcium contents were lower in caffeine group than that of decaffeine one. Mean serum magnesium content for three hour after caffeine ingestion was affected by caffeine consumption(p<0.001). Mean serum content of potassium was unaffected by caffeine consumption. 4) Total urinary four hour excretion of sodium, increased significantly after caffeine consumption(p<0.05), while total urinary four hour excretion of potassium, calcium, phosphorus and magnesium was unchanged after caffeine intake. Urinary excretion of Na, Ca, P and Mg was greatest at one hour after caffeine consumption, especially urinary sodium and potassium excretion was significantly high(p<0.05, p<0.01). The above results show that only 3mg caffeine per kg body weight increase the urinary macro mineral excretion in healthy young females.

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Effects of the Structured Nursing Intervention Program on Dysmenorrhea of Middle School Girls (구조화된 간호중재 프로그램이 여중생의 월경곤란증 완화에 미치는 영향)

  • Choi, Soung-Hee;Kim, Hyeon Ok
    • Journal of the Korean Society of School Health
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    • v.14 no.1
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    • pp.145-160
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    • 2001
  • The main purpose of this study is to identify the effects of a structured nursing intervention program on dysmenorrhea in middle school girls. This study employed two methods of research at the same time: a quasi-experiment pre- and post-test to use for comparison. Subjects were middle school girls assigned to the research program: 40 girls in the second grade, 40 girls in the third grade at K Girls' Middle School and H Girls' Middle School located in J city. The data were collected for 68 days from August 23 to October 30, 1999. The data were collected by observation technique and by a self-administered questionnaire. The instruments used for this study were as follows: the "Face Interval Pain Scale" menstrual pain instrument developed by McGreth(1987) and the "Menstrual Distress Questionnaire" dysmenorrhea instrument developed by Moos(1968). The dysmenorrhea knowledge instrument was developed by the researcher and refered to above. The research procedure was as follows: after preliminary examination, the experimental groups were provided educational programs with O.H.P. films developed by the researcher and with the videotape "first meeting" supported by P&G company and produced by EBS. The groups followed the educational programs twice for two weeks. At the beginning of menstruation, these subjects could choose one among the following choices: * Jacobson's progressively muscle relaxation method and massage treatment * Jacobson's progressively muscle relaxation method and hot bag treatment * Jacobson's progressively muscle relaxation method, a pain killer treatment, and massage treatment * Jacobson's progressively muscle relaxation method, a pain killer treatment, and hot bag treatment The dysmenorrhea of the control group were measured during the same period. The analysis of the collected data was done using an SPSS-PC+, descriptive statistic including real numbers, percentage, averages, standard deviations and t-test, $x^2$ test, and ANCOVA. The results of this study were as follows. (1) The knowledge level of the girls provided with the planned nursing intervention program was higher when compared to these who did not follow the educational programs. (2) The original difference in the dysmenorrhea level having been controled, the dysmenorrhea level made, nevertheless, a statistical difference between the experimental group and the control group(F=63.8, p=.00). Observed pain on quantity measurement of dysmenorrhea showed significant difference depending on the treatment(t=4.6, p=.00). In conclusion, those in the planned nursing intervention program had a higher knowledge level and fewer symptoms than the control group. Accordingly, the nursing intervention program for dysmenorrhea developed by the researcher can be effectively applied in nursing practice and can be the foundation for this kind of program.

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Effects of Different Levels of Concentrate in the Diet on Physicochemical Traits of Korean Native Black Goat Meats

  • Kim, Sang Woo;Park, Seong Bok;Kim, Myeong Jik;Kim, Dong Hun;Yim, Dong-Gyun
    • Food Science of Animal Resources
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    • v.34 no.4
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    • pp.457-463
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    • 2014
  • The effects of feeding of diets based on roughage supplemented with concentrate on the carcass and meat quality attributes of Korean black goats were investigated. The 40 male goats at 5 mon age were divided into four treatment groups; T1 (1.5%), T2 (2.0%), T3 (2.5%) and T4 (ad libitum) feeding of concentrate with ad libitum rice straw. Forty bucks at the end of the feeding were fasted for 12 h before slaughter and were then slaughtered. For carcass measurement, cold buck carcasses were examined after 24 h of chilling at $5^{\circ}C$. The carcasses were chilled in refrigerator at $2{\pm}2^{\circ}C$ for 24 h, then the longissimus dorsi muscle was removed from the carcasses. The samples were separately vacuum packaged, frozen and stored at $-20^{\circ}C$ for up to 1 mon, prior to physicochemical evaluations. Carcass yields were greatly affected by rate of concentrate feeding. T4 showed the heaviest live and carcass weights and the highest dressing and fat percentages (p<0.05). The moisture contents were lower in T4 compared with other treatments, while the crude protein and fat contents were higher (p<0.05). mono-unsaturated fatty acid in T4 was significantly higher than others, which showed the highest percentages of oleic acid (C18:1). For the sensory test, T4 was tenderer and produced better flavor scores than others. Increasing the level of concentrate in the diet resulted in an improvement in growth performance, and carcass and physicochemical characteristics of goat meats.

Accuracy of different electronic torque drivers: A comparative evaluation

  • Ko, Byeong-Dae;Son, KeunBaDa;Kang, Seok Hyon;Lee, Kyu-Bok
    • The Journal of Advanced Prosthodontics
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    • v.11 no.6
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    • pp.350-357
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    • 2019
  • PURPOSE. This study aims to evaluate the loosening torque on the implant fixture, and to assess the accuracy of difference electronic torque drivers. MATERIALS AND METHODS. Three electronic torque drivers were used to measure the loosening torque on the implant system (AnyOne; MegaGen). The implant fixtures were divided among the 3 electronic torque driver types (W&H, SAESHIN, and NSK group) and 9 for each group. The screws were fastened at the implant fixture by three electronic torque drivers using the tightening torques recommended by the manufacturers of the drivers. After 10 minutes, the screws were again fastened at the implant fixture with equal torque. Then, the loosening torques were measured with an MGT12 torque gauge (MARK-10, Inc.). This measurement procedure was repeated 10 times under loosening torques of 15 Ncm, 25 Ncm, and 35 Ncm. In the statistical analysis, all values of loosening torque were analyzed with the one-way ANOVA and Kruskal-Wallis test (α=.05) for comparative evaluation. RESULTS. There were significant inter-group differences at loosening torques of 15 Ncm and 25 Ncm (P<.05). The accuracy of the NSK driver was the highest, followed by SAESHIN and W&H. There was no significant difference between NSK and W&H at 35 Ncm (P>.05). The SAESHIN driver showed the closest loosening torque at 35 Ncm. CONCLUSION. The most accurate loosening torques were SAESHIN at 35 Ncm, and NSK at 15 Ncm and 25 Ncm. Since the loosening torque may vary depending on the tightening torques and electronic torque drivers, periodic calibration of the electronic torque driver is recommended.

Effect of universal adhesive pretreatments on the bond strength durability of conventional and adhesive resin cements to zirconia ceramic

  • Tae-Yub Kwon;Seung-Hee Han;Du-Hyeong Lee;Jin-Woo Park;Young Kyung Kim
    • The Journal of Advanced Prosthodontics
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    • v.16 no.2
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    • pp.105-114
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    • 2024
  • PURPOSE. This study aimed to evaluate the effect of pretreatment of three different universal adhesives (Single Bond Universal [SBU], All-Bond Universal [ABU], and Prime&Bond universal [PBU]) on the bonding durability of an adhesive (Panavia F 2.0, PF) and a conventional (Duo-Link, DL) resin cements to air-abraded zirconia. MATERIALS AND METHODS. Rectangular-shaped zirconia specimens were prepared. The chemical composition and surface energy parameters of the materials were studied by Fourier transform infrared spectroscopy and contact angle measurement, respectively. To evaluate resin bonding to the zirconia, all the bonding specimens were immersed in water for 24 h and the specimens to be aged were additionally thermocycled 10000 times before the shear bond strength (SBS) test. RESULTS. The materials showed different surface energy parameters, including the degree of hydrophilicity/hydrophobicity. While the DL/CON (no pretreatment) showed the lowest SBS and a significant decrease in the value after thermocycling (P < .001), the PF/CON obtained a higher SBS value than the DL/CON (P < .001) and no decrease even after thermocycling (P = .839). When the universal adhesives were used with DL, their SBS values were higher than the CON (P < .05), but the trend was adhesive-specific. In conjunction with PF, the PF/SBU produced the highest SBS followed by the PF/ABU (P = .002), showing no significant decrease after thermocycling (P > .05). The initial SBS of the PF/PBU was similar to the PF/CON (P = .999), but the value decreased after thermocycling (P < .001). CONCLUSION. The universal adhesive pretreatment did not necessarily show a synergistic effect on the bonding performance of an adhesive resin cement, whereas the pretreatment was beneficial to bond strength and durability of a conventional resin cement.

Assessment of 23 kV Capacitive Coupler for On-line Partial Discharge Measurements

  • Jeong, J.Y.;Kang, D.S.;Sun, J.H.;Heo, J.C.;Park, C.H.
    • Journal of Electrical Engineering and Technology
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    • v.4 no.1
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    • pp.123-130
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    • 2009
  • The partial discharge (PD) measurement is a very effective method to assess the winding insulation condition of high-voltage machines, since most of the insulation failure processes are directly or indirectly caused by PD. On-line PD measurements, which can detect insulation defects of winding in the early stages on rotating machines in operation, have been accepted as the most important technique. The epoxy mica capacitive coupler is currently and extensively used for on-line detection of PD pulses of high-voltage rotating machines. To evaluate the feasibility of developing a capacitive coupler that is easier to manufacture at a lower cost compared to epoxy mica couplers, a 100pF capacitive coupler made of ceramic material is designed, fabricated and tested for on-line PD measurements of 23 kV electrical machines. A series of electrical tests and accelerated aging tests are performed on the ceramic coupler to evaluate the performance requirements, long-term reliability and thermal stability for in field application. The test results show that the newly developed ceramic coupler provides equal and improved performance at a lower cost compared to epoxy mica couplers, and estimated voltage life is anticipated to surpass 100 years.

Experimental Evaluation of Superconductor Flywheel Energy Storage System with Hybrid Type Active Magnetic Bearing (하이브리드 AMB를 포함한 초전도 플라이휠 에너지 저장장치의 실험평가)

  • Lee, J.P.;Kim, H.G.;Han, S.C.
    • Progress in Superconductivity
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    • v.13 no.3
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    • pp.195-202
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    • 2012
  • In this paper, we designed Active Magnetic Bearing (AMB) for large scale Superconductor Flywheel Energy Storage System (SFESS) and PD controller for AMB. And we experimentally evaluated SFESS including hybrid type AMB. The radial AMB was designed to provide force slew rate that was sufficient for the unbalance disturbances at the maximum operating speed. The thrust AMB is a hybrid type where a permanent magnet carries the weight of the flywheel and an electromagnetic actuator generates the dynamic control force. We evaluated the design performance of the manufactured AMB through comparison of FEM analysis and the results of experimental force measurement. In order to obtain gains of PD controller and design a notch filter, the system identification was performed through measuring frequency response including dynamics for the AMBs, a power amp and a sensor using a sine swept test method after levitating the flywheel. Through measuring the current input of the AMBs and the orbit of a flywheel according to rotational speed, we verified excellent control performance of the AMBs with small amount current for the large scale SFESS.

Measurement of Heat Leak through Multi-Layer Insulation (적층단열재의 열침입량 측정)

  • Kim D. L.;Yang H. S.;Jung W. M.;Lee B. S.;Shin P. K.;Hwang S. D.
    • Progress in Superconductivity and Cryogenics
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    • v.7 no.3
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    • pp.39-42
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    • 2005
  • In this paper, the thermal characteristics of multilayer insulation (MLI) were experimentally investigated by using boil-off calorimetry method for seeking optimum standards of thermal insulation conditions. It is necessary to design the thermal insulating efficiency for applying to cryogenic instruments such as HTS power cable system. It is well known that the thermal characteristics and heat transfer of MLI are greatly affected by various MLI structures such as the number of layers and layer density, etc. However, it is difficult to know the thermal characteristics of MLI correctly. The heat leak by MLI between room temperature and liquid nitrogen temperature was measured at various conditions using a cylindrical cryostat. The cryostat consists of two guard vessels located at both end sides and a test vessel between them. The guard vessels are also filled with liquid nitrogen to prevent radiation heat leak through the both end side of the cylindrical test vessel to measure the heat leak only through MLI.

A Study on the Mechanical Properties and Corrosion Resistance of GCD40 by Plasma Nitriding (플라즈마 질화처리한 GCD40의 기계적성질 및 내식성에 관한 연구)

  • Kim, M.K.;Jung, B.H.;Kim, S.S.
    • Journal of Power System Engineering
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    • v.6 no.1
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    • pp.74-81
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    • 2002
  • The characteristics of corrosion resistance for the surface of ductile cast iron(GCD40) by plasma nitriding process have been studied in terms of electrochemical polarization behaviors including corrosion potential($E_{corr}$), anodic polarization trends, polarization resistance($R_p$), and also have been studied microstructures, hardness and specific wear of nitrided layer Nitrided layer showed an enhanced hardness values in all the plasma nitriding condition investigated. In the result of wear test, specific wear of nitrided specimens were much decreased than that of non-treated specimens. In the results of XRD, ${\gamma}'phase\;and\;{\varepsilon}$ phase were detected in nitrided surface. And it was found that ${\varepsilon}$ phase was decreased and ${\gamma}'phase$ was increased respectively, as the nitriding time became longer. In the test of corrosion resistance, natural potentials in all the nitrided specimens were towards noble directions than in the case of non-treated specimens. The measurement of electrode potentials revealed that corrosion resistivity of plasma nitrided specimens were higher than in the case of the non-treated specimens.

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