• 제목/요약/키워드: pK$_a$ Values

검색결과 8,285건 처리시간 0.047초

Surface pH Of The Northeastern Pacific Ocean

  • Park, Kilho
    • 한국해양학회지
    • /
    • 제1권1_2호
    • /
    • pp.1-6
    • /
    • 1966
  • A latitudinal, differential pH distribution is observed in the Northeastern Pacific Ocean with a pH range of 8.15 at high latitude (42 N) to 8.29 at low latitude (23 N). These pH values are generally greater than the calculated equilibrium pH with respect to atmospheric carbon dioxide. If we assume that the calculated equilibrium pH values ae valid, then the surface waters are undersaturated with respect to the atmospheric carbon dioxide during April to June 1966. A high surface pH value of about 8.26 was observed immediately south of the SubarcticBoundary zone near 170 W. This value differs from the equilibration pH by as much as 0.1 unit.

  • PDF

Additivity of values for phosphorus digestibility in corn, soybean meal, and canola meal in diets fed to growing pigs

  • She, Yue;Wang, Qiuyun;Stein, Hans H.;Liu, Ling;Li, Defa;Zhang, Shuai
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제31권8호
    • /
    • pp.1301-1307
    • /
    • 2018
  • Objective: This study was conducted to determine the apparent and standardized total tract digestibility (ATTD and STTD) of phosphorus (P) in corn, soybean meal (SBM), and canola meal (CM), and additivity of values for ATTD and STTD of P in corn, SBM, and CM in diets fed to growing pigs. Methods: Thirty-six growing barrows (initial body weight of $21.6{\pm}1.7kg$) were placed in metabolism crates and allotted to a completely randomized design with 6 diets and 6 pigs per diet. Six diets were formulated using corn, SBM or CM as the sole source of P, or corn and SBM, or corn and CM, or corn, SBM, and CM as the P source in each diet, respectively. Fecal samples were collected for 5 d following a 7 d adaptation period to the diets. Results: Values for ATTD and STTD of P in corn, SBM, and CM in growing pigs were 33.12% and 37.76%, 50.19% and 56.62%, 34.93% and 39.45%, respectively. The ATTD and STTD of P in SBM were greater (p<0.05) than those in corn and CM. However, there were no differences in the ATTD or STTD of P between corn and CM. The determined STTD of P in the mixture of corn and SBM, corn and CM, and corn, SBM, and CM is not different from the calculated STTD values. Conclusion: Values for STTD of P in corn, SBM, and CM are additive in their mixture fed to growing pigs.

Effect of pH values and inoculation amounts for α-glucosidase inhibitory activity in mulberry leaf fermentation

  • Kwon, O-Chul;Ju, Wan-Taek;Kim, Hyun-Bok;Sung, Gyoo-Byung;Kim, Yong-Soon
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • 제34권2호
    • /
    • pp.38-44
    • /
    • 2017
  • Mulberry leaves containing 1-deoxynojirimycin (DNJ) have been recognized as a potentially important source for prevent or treat hyperglycemia. However, DNJ content of natural mulberry leaf are as low as 0.1%. Thus, the most effective method for increasing ${\alpha}$-glucosidase inhibitory activity with the DNJ high-production is needed. In this study, we investigated the influence of ${\alpha}$-glucosidase inhibitory activity according to different pH values (6-9) and inoculation amounts (0.1-0.5%) when Bacillus subtilis cultured on mulberry leaf powder media. We confirmed that ${\alpha}$-glucosidase inhibitory activity was difference according to culture conditions of different pH values, inoculation amounts, and fermentation times. The results of mulberry leaf fermentation according to pH values and inoculation amounts were shown that the optimal conditions for ${\alpha}$-glucosidase inhibitory activity were defined as pH 7 and 9, inoculation amount 0.4%, and incubation until 2 to 4 days. These results can be provided a basic data for the optimal culture conditions increasing ${\alpha}$-glucosidase inhibitory activity from mulberry leaf fermentation.

차가버섯 추출염액을 이용한 면직물의 염색성과 항균효과 (Dyeing Properties and Antibacterial Activity of Cotton Fabric with Inonotus obliquus)

  • 김성희
    • 한국의류학회지
    • /
    • 제33권11호
    • /
    • pp.1774-1780
    • /
    • 2009
  • The dyeing properties of cotton fabric with Inonotus obliquus are studied by investigating the effect of dyeing conditions on dye uptakes such as, the concentration of Inonotus obliquus, dyeing temperature, time, and pH values. In addition, the effects of mordants on dye uptakes and antibacterial activities are also investigated. The results are summarized as follows: The dye uptakes of dyed fabrics were increased gradually with an increasing concentration of Inonotus obliquus. K/S values were the highest when the dyeing temperature and time were at $60^{\circ}C$ and 60 minutes, respectively. As for the changes of pH values of dyeing solution, K/S values recorded the highest at pH3-pH5. Antibacterial activities of Inonotus obliquus dyeing solution showed a significant effect in dyed cotton fabric with mordanting.

The effect of ceramic thickness and number of firings on the color of a zirconium oxide based all ceramic system fabricated using CAD/CAM technology

  • Bachhav, Vinay Chila;Aras, Meena Ajay
    • The Journal of Advanced Prosthodontics
    • /
    • 제3권2호
    • /
    • pp.57-62
    • /
    • 2011
  • MATERIALS AND METHODS. Ceramics have a long history in fixed prosthodontics for achieving optimal esthetics and various materials have been used to improve ceramic core strength. However, there is a lack of information on how color is affected by fabrication procedure. The purpose of this study was to evaluate the effects of various dentin ceramic thicknesses and repeated firings on the color of zirconium oxide all-ceramic system (LavaTM) fabricated using CAD/CAM technology. MATERIALS AND METHODS. Thirty disc-shaped cores, 12 mm in diameter with a 1 mm thickness were fabricated from zirconium oxide based all ceramic systems ($Lava^{TM}$, 3M ESPE, St Paul, MN, USA) and divided into three groups (n = 10) according to veneering with dentin ceramic thicknesses: as 0.5, 1, or 1.5 mm. Repeated firings (3, 5, 7, or 9) were performed, and the color of the specimens was compared with the color after the initial firing. Color differences among ceramic specimens were measured using a spectrophotometer (VITA Easyshade, VITA Zahnfabrik, Bad $S{\ddot{a}}ckingen$, Germany) and data were expressed in CIELAB system coordinates. A repeated measures ANOVA and Bonferroni post hoc test were used to analyze the data (n = 10, ${\alpha}=.05$). RESULTS. $L^{\ast}a^{\ast}b^{\ast}$ values of the ceramic systems were affected by the number of firings (3, 5, 7, or 9 firings) (P<.001) and ceramic thickness (0.5, 1, or 1.5 mm) (P<.001). Significant interactions were present in $L^{\ast}a^{\ast}b^{\ast}$ values between the number of firings and ceramic thickness (P<.001). An increase in number of firings resulted in significant increase in $L^{\ast}$ values for both 0.5 mm and 1.5 mm thicknesses (P<.01, P=.013); however it decreased for 1 mm thickness (P<.01). The $a^{\ast}$ values increased for 1 mm and 1.5 mm thicknesses (P<.01), while it decreased for 0.5 mm specimens. The $b^{\ast}$ values increased significantly for all thicknesses (P<.01, P=.022). As the dentin ceramic thickness increased, significant reductions in $L^{\ast}$ values (P<.01) were recorded. There were significant increases in both $a^{\ast}$ and $b^{\ast}$ values (P<.01) as the dentin ceramic thickness increased. CONCLUSION. The number of firings and dentin ceramic thickness have a definite effect on the final color of all ceramic system tested. The mean ${\Delta}E$ value increased as the dentin ceramic thicknesses increased for zirconium-oxide based all ceramic specimens tested. However, the mean ${\Delta}E$ values were less than 3.7${\Delta}E$ units which is rated as a match in the oral environment.

반응표면분석법을 이용한 시금치 페스토 제조조건의 최적화 (Optimization of Spinach Pesto by Response Surface Methodology)

  • 김옥선;박종대;금준석;최윤상;최현욱;성정민
    • 한국식품영양학회지
    • /
    • 제29권4호
    • /
    • pp.583-594
    • /
    • 2016
  • The purpose of this study was to determine the optimal mixing ratio of olive oil, parmesan cheese, and nuts for preparation of pesto with spinach. Based on a surface response methodology (RSM), the independent variables were olive oil (100~300 g), parmesan cheese (25~75 g) and nuts (12~36 g). The dependent variables were physico-chemical properties as pH, color values (L, a, and b values), viscosity and sensory evaluation. pH decreased with increasing parmesan cheese levels. The L value decreased and the a and b values increased with increasing olive oil levels. Viscosity was negatively correlated with olive oil levels but positively correlated with the amounts of parmesan cheese and nuts. The addition of oil exerted a positive effect on gloss, and oily taste. In the sensory evaluation, the values of appearance, color, flavor, taste and overall acceptance were in the range of 4.4~7.2, 3.7~7.4, 4.4~7.1, 3.9~7.3 and 3.5~7.6, respectively. The sensory evaluation results showed significant values in appearance (p<0.01), flavor (p<0.01), taste (p<0.01) and overall acceptance (p<0.05). The optimal amounts of spinach pesto with olive oil, parmesan cheese, and nuts were determined by numerical optimization of a canonical model and graphical optimization. The optimal amounts were 175.29 g of olive oil, 49.51 g parmesan cheese, and 27.37 g of nuts per 100 g of spinach.

Glass Dissolution Rates From MCC-1 and Flow-Through Tests

  • Jeong, Seung-Young
    • 한국방사성폐기물학회:학술대회논문집
    • /
    • 한국방사성폐기물학회 2004년도 학술논문집
    • /
    • pp.257-258
    • /
    • 2004
  • The dose from radionuclides released from high-level radioactive waste (HLW) glasses as they corrode must be taken into account when assessing the performance of a disposal system. In the performance assessment (PA) calculations conducted for the proposed Yucca Mountain, Nevada, disposal system, the release of radionuclides is conservatively assumed to occur at the same rate the glass matrix dissolves. A simple model was developed to calculate the glass dissolution rate of HLW glasses in these PA calculations [1]. For the PA calculations that were conducted for Site Recommendation, it was necessary to identify ranges of parameter values that bounded the dissolution rates of the wide range of HLW glass compositions that will be disposed. The values and ranges of the model parameters for the pH and temperature dependencies were extracted from the results of SPFT, static leach tests, and Soxhlet tests available in the literature. Static leach tests were conducted with a range of glass compositions to measure values for the glass composition parameter. The glass dissolution rate depends on temperature, pH, and the compositions of the glass and solution, The dissolution rate is calculated using Eq. 1: $rate{\;}={\;}k_{o}10^{(ph){\eta})}{\cdot}e^{(-Ea/RT)}{\cdot}(1-Q/K){\;}+{\;}k_{long}$ where $k_{0},\;{\eta}$ and Eaare the parameters for glass composition, pH, $\eta$ and temperature dependence, respectively, and R is the gas constant. The term (1-Q/K) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_{0},\;{\eta}\;and\;E_{a}$ are the parameters for glass composition, pH, and temperature dependence, respectively, and R is the gas constant. The term (1-Q/C) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_0$, and Ea are determined under test conditions where the value of Q is maintained near zero, so that the value of the affinity term remains near 1. The dissolution rate under conditions in which the value of the affinity term is near 1 is referred to as the forward rate. This is the highest dissolution rate that can occur at a particular pH and temperature. The value of the parameter K is determined from experiments in which the value of the ion activity product approaches the value of K. This results in a decrease in the value of the affinity term and the dissolution rate. The highly dilute solutions required to measure the forward rate and extract values for $k_0$, $\eta$, and Ea can be maintained by conducting dynamic tests in which the test solution is removed from the reaction cell and replaced with fresh solution. In the single-pass flow-through (PFT) test method, this is done by continuously pumping the test solution through the reaction cell. Alternatively, static tests can be conducted with sufficient solution volume that the solution concentrations of dissolved glass components do not increase significantly during the test. Both the SPFT and static tests can ve conducted for a wide range of pH values and temperatures. Both static and SPFt tests have short-comings. the SPFT test requires analysis of several solutions (typically 6-10) at each of several flow rates to determine the glass dissolution rate at each pH and temperature. As will be shown, the rate measured in an SPFt test depends on the solution flow rate. The solutions in static tests will eventually become concentrated enough to affect the dissolution rate. In both the SPFt and static test methods. a compromise is required between the need to minimize the effects of dissolved components on the dissolution rate and the need to attain solution concentrations that are high enough to analyze. In the paper, we compare the results of static leach tests and SPFT tests conducted with simple 5-component glass to confirm the equivalence of SPFT tests and static tests conducted with pH buffer solutions. Tests were conducted over the range pH values that are most relevant for waste glass disssolution in a disposal system. The glass and temperature used in the tests were selected to allow direct comparison with SPFT tests conducted previously. The ability to measure parameter values with more than one test method and an understanding of how the rate measured in each test is affected by various test parameters provides added confidence to the measured values. The dissolution rate of a simple 5-component glass was measured at pH values of 6.2, 8.3, and 9.6 and $70^{\circ}C$ using static tests and single-pass flow-through (SPFT) tests. Similar rates were measured with the two methods. However, the measured rates are about 10X higher than the rates measured previously for a glass having the same composition using an SPFT test method. Differences are attributed to effects of the solution flow rate on the glass dissolution reate and how the specific surface area of crushed glass is estimated. This comparison indicates the need to standardize the SPFT test procedure.

  • PDF

자초(紫草)추출물의 외관상 변색 (Visual Color Deterioration of the Extract of Lithospermi radix)

  • 윤희남;김호;신용달;유무영
    • 한국식품과학회지
    • /
    • 제17권6호
    • /
    • pp.426-430
    • /
    • 1985
  • 자초(紫草)추출물의 외관상 변색에 영향을 주는 온도와 pH에 대해 조사하였다. 변색은 Hunter치(値)의 차이로 표시 할 수 있으며 자초추출물의 Hunter치(値)는 $50^{\circ}C$ 이상에서 변화하기 시작하고 $60^{\circ}C$ 이상에서는 온도와 상관관계를 이루었다. 온도에 따른 Hunter L, a, b, 치(値)의 변이상관계수는 열처리 시간이 증가함에 따라 감소하였으며, 전체변색의 상관계수는 증가하였다. 66.7% 에탄올로 추출한 추출물을 1시간 열처리 할때 Hunter치(値) 변이 상관계수는 L치(値)의 경우 -0.3696, a치(値)의 경우 -0.4124, b치(値)의 경우 -0.2279, 전체 변색에 있어선 0.5983이었다. 이 때 전체변색의 상관계수는 Hunter L, a, b 각각의 상관계수로부터 직접 계산할 수 있었으며 0.5988로서 거의 비슷한 값을 보여주었다. 한편 pH를 낮추면 Hunter a치(値)는 감도하고 L, b치(値)는 약간 증가하였으나 pH를 증가시키면 pH6.5를 전후로 해서 Hunter L, a, b 치(値) 모두 다 급격히 감소하여 외관상 색깔이 좋지 않았다. 자초(紫草)추출물은 pH가 4.0-6.5일 때 외관상 가장 좋은 '선명한 붉은색'을 나타내었다.

  • PDF

진도견의 혈액화학치 및 성장에 따른 체형에 관한 연구 I. 진도견의 혈액화학치 (Studies on body types by body growth and blood chemical values in the Jindo dog 1. Blood chemical values of Jindo dogs)

  • 김우권;이재홍;김자숙
    • 대한수의학회지
    • /
    • 제29권3호
    • /
    • pp.263-274
    • /
    • 1989
  • The present study was conducted ill. order to get the normal blood chemical values of Korean Jindo dogs. Blood samples were taken from 160(♂34, ♀126) healthy Jindo dogs in Jindo area. The results obtained in this study were summarized as follows: 1. The mean values of serum total protein(TP), albumin(Alb) and globulin(Glb) content, cholesterol(Chole), magnesium(Mg), calcium(Ca), inorganic phosphate(P), potassium(K), sodium(Na) and chloride(Cl) concentration in the group of less than one year old were 6.64(♂6.62, ♀6.64), 3.63(♂3.57, ♀3.65) and 3.00(♂3.05, ♀2.99)g/100ml, 170.97(♂166.46, ♀172.68)mg/100ml, 1.45(♂1.43, ♀1.46), 5.76(♂5.62, ♀5.81), 4.80(♂4.95, ♀4.75), 4.84(♂4.72, ♀4.89), 148.93(♂148.79, ♀148.98) and 110.22(♂110.42, ♀110.14)mEq/L, respectively, whereas the TP, Alb and Glb content, Chole Mg, Ca, P, K, Na and Cl concentration in the group of one year old and more were 6.88(♂6.84, ♀6.89), 3.65(♂3.63, ♀3.66) and 3.23(♂3.21, ♀3.23)g/100ml, 167.48(♂173.80, ♀166.48)mg/100ml, 1.40(♂1.36, ♀1.40), 5.69(♂5.53, ♀5.71), 4.62(♂4.73, ♀4.60), 4.88(♂4.90, ♀4.87), 149.86(♂149.60, ♀149.90) and 110.03(♂110.70, ♀109.92)mEq/L, respectively. The ratios of mean serum albumin to globulin(A/G), calcium to inorganic phosphate(Ca/P) and sodium to potassium(Na/K) in the group of less than one year old were 1.21(♂1.17, ♀1.22), 1.20(♂1.14, ♀1.22) and 30.77(♂31.52, ♀30.47), respectively, whereas the A/G, Ca/P and Na/K in the group of one year old and more were 1.13(♂1.13, ♀1.13), 1.23(♂1.17, ♀1.24) and 30.71(♂30.53, ♀30.78), respectively. 2. The mean values of Alb content, Mg, Ca and K concentration, A/G and Ca/P ratio appeared to be higher in the female than in the male, whereas the reverse was the case with P concentration. No differences were found between male and female in the TP and Glb content, Chole, Na and Cl concentration and Na/K ratio. 3. The mean values of Glb content appeared to be higher in the group less than one year old than in the group of one year old and more, whereas the reverse was the case with A/G ratio. The mean values of TP and Alb content and Ca/P ratio in the age groups less than one year tended to increase with aging, whereas the reverse was the case with Ca and P concentration. No differences were found between age groups in the Mg, K, Na and Cl concentration and Na/K ratio.

  • PDF