• Korean Journal of Food Science and Technology
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• v.50 no.3
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• pp.324-330
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• 2018

In this study, we examined the effects of carrier oil type (MCT oil: MO, corn oil: CO, palm oil: PO), pH of dispersion solution, and antioxidants on the chemical degradation of ${\beta}$-carotene in oil-in-water nanoemulsions. The pH of the emulsion had a significant influence on the stability of ${\beta}$-carotene, which showed rapid degradation in emulsions at low pH value and relatively higher stability at high pH values. The influence of the carrier oil type on ${\beta}$-carotene stability was assessed. The rate of ${\beta}$-carotene degradation increased in the following order: CO > PO > MO. The effect of antioxidants on ${\beta}$-carotene degradation was monitored during storage at $25^{\circ}C$ for 4 weeks. The rate of ${\beta}$-carotene degradation decreased upon addition of water-soluble (ascorbic acid) or oil-soluble (tocopherol) antioxidants. In general, tocopherol was more effective than ascorbic acid in reducing ${\beta}$-carotene degradation. To utilize this nanoemulsion for producing acidic beverages, adding a higher concentration of antioxidants is required.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.821-832
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• 2004

A total of 80 pigs were used to investigate the effect of dietary glycine betaine(N,N,N-trimethylglycine) on pork quality during cold storage. About 70 kg pigs were randomly a1loted into one of four experimental diet groups(0%, 0.2%, 0.4% and 0.6% glycine betaine). Pigs were slaughtered at approximately 110 kg live weight, and pH, color(CIE $L^* a^* b^*$), shear force, sarcomere length, lipid oxidation and composition of fatty acid were measured in pork loin for 13 days of cold storage. The concentration of glycine betaine in pork loin was significantly increased(P<0.05) with increasing of glycine betaine level in diet. Pork loins from dietary betaine groups showed significantly higher muscle pH and lower CIE $b^*$ values compared to control group after 13 days of storage. There were significant differences in shear force values among pork loins from diet groups at 24 hrs postmortem. However, pork loins from control diet showed longer sarcomere length than those of dietary betaine groups. Dietary glycine betaine increased the ratio of saturated fatty acids and decreased unsaturated fatty acids in pork loins. Especially the ratios of linoleic and myristic acid were decreased with increasing dietary betaine level. However, dietary glycine betaine did not affect lipid oxidation (TSARS) and sensory evaluation during cold storage.

• Journal of the Korean Ceramic Society
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• v.38 no.8
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• pp.749-754
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• 2001

마이크로파 추출 및 하소 공정을 통하여 카올린으로부터 베타 알루미나 전구체 및 베타 알루미나 분말을 합성하였다. 황산 알루미늄 및 가성소다의 혼합 용액을 교반되는 에탄올 용액 중에 적하시켜서 $Al_2$(SO$_4$)$_3$.17$H_2O$ 및 $Na_2$SO$_4$.10$H_2O$의 균일한 침전물을 얻었다. $\beta$- 및 $\beta$\"-Al$_2$O$_3$상으로 구성된 베타 알루미나를 얻기 위하여 재래식 및 마이크로파 하소법으로 주어진 온도에서 약 2h 동안 침전물 시료를 하소하였다. 재래식 하소된 시료에 비하여 마이크로파 하소된 시료는 $\beta$\"-Al$_2$O$_3$상이 상대적으로 많이 존재하였다. 또한, 재래식 하소된 시료와 마이크로파 하소된 시료의 미세구조는 매우 상이하였다. 매우 상이하였다.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.367-376
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• 2022

One of biopolymer, β-glucan (BG) chains were crosslinked by citric acid under the heating condition for the adsorption of Pb and Cu ions in the aqueous solution. The variation of functional groups on BG itself and crosslinked β-glucan (CBG) with their surface adsorption characteristics were investigated by FTIR and SEM-EDX. Adsorption kinetic results showed that adsorption of Pb and Cu onto the CBG followed the pseudo-second-order kinetic model and intra-particle diffusion model. The Langmuir adsorption model was depicted better adsorption characteristics than the Freundlich model. The adsorption capacities of Pb and Cu onto the CBG estimated by the Langmuir model were 59.70 and 23.44 mg/g, respectively. This study suggested that CBG may act as an eco-friendly adsorbent for the adsorption of Pb and Cu in the aqueous solution.

• Clinical and Experimental Reproductive Medicine
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• v.10 no.2
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• pp.1-11
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• 1983

${\beta}$-Glucuronidase from bull seminal plasma was partially purified by $(NH_4)_2SO_4$fractionation, two successive DEAE-cellulose columns, isoelectric focusing (pH 4 to 6) and Gel filtration on Sephadex G-200. Only one form of ${\beta}$-glucuronidase was obtained by isoelectric focusing at pH 5.13. Highly purified ${\beta}$-glucuronidase had specific activity of 34 units/mg protein and showed one major and some minor contaminants by disc gelk electrophoresis. The enzyme showed maximum activity at pH 5.2 and at $48^{\circ}C$. The enzyme was completely inhibited by 1,4 saccharo-${\alpha}$-lactone (5 mM). Albumin and 0.15 M NaCl increased the ${\beta}$-glucuronidase activity. Km of ${\beta}$-glucuronidase using phenolphthalein mono-${\beta}$-glucuronic acid as substrate was 2.9 mM and Vmax was $0.8{\mu}$mole/min. The enzyme appeared to be a glycoprotein by its binding to concanvalin·A. Rabbit and human sperm-acrosomal extracts and seminal plasma showed high ${\beta}$-glucuronidase activity.

• Journal of Radiation Protection and Research
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• v.18 no.2
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• pp.17-25
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• 1993

Beta ray spectra of $^3H,\;^{14}C\;and\;^{36}Cl$ in liquid scintillation counting system have been calculated using the Monte Carlo method by which physical behaviors of particle transport in medium were simulated. The calculations have been carried out on the basis of beta rays being slowing down according to the continuous slowing down approximation(CSDA) model. Beta rays generated in simulation geometry were traced until they lost their energy below 0.3keV that in known to be the detection limit in the liquid scintillation counter. Scintillator solution in which pure beta emitting radionuclides were dissolved uniformly was assumed to be bottled in the shape of right circular cylinder with 12.5mm in radius and 35mm in height. The comparison of the calculated and measured results showed satisfactory agreement between those two, with slight discrepancy due to self quenching in the case of lower energy of emitted beta particles in the solution.

• Journal of Radiation Protection and Research
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• v.26 no.4
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• pp.375-384
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• 2001

It is possible to count and perform quench correction on two ${\beta}$ -label samples so long as the maximum ${\beta}$-energies are sufficiently different. However, when 4he conventional technique is applied to the radioassay of a mixture of more than three nuclides, the reliability of the activities determined is considerably reduced, resulting from the large overlapping of liquid scintillation pulse height distributions of each nuclide. A technique that allows the activities of multiple ${\beta}$-labeled samples to be radioassayed was proposed by using the least square method. The technique was applied to mixture samples of $^3H,\;^{14}C,\;^{36}Cl$, and $^{90}Sr$. The analytical values were in good agreement with the reference values within 7% relative error.

• Journal of Radiation Protection and Research
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• v.24 no.1
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• pp.39-43
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• 1999

Thermoluminescent (TL) response characteristics of a thin LiF:Mg,Cu,Na,Si Teflon detectors have been studied for use in beta radiation detection. The detectors were fabricated from a mixture of LiF:Mg,Cu,Na,Si phosphor and Teflon powder which was molded into a thin disk form of $50mg/cm^2$ thickness. These detectors were irradiated to beta fields of $^{147}Pm,\;^{204}Tl\;and\;^{90}Sr/^{90}Y$ sources with a covering of Kapton foil ($2mg/cm^2$) and photon irradiation was carried out with a $^{137}Cs$ source at the Korea Atomic Energy Research Institute (KAERI). Batch uniformity was estimated to be 4.7% and the beta dose response presented linear relationship from 0.1 mGy to 100 Gy. The beta energy responses of thin detectors normalized to $^{137}Cs$ were presented as 0.46, 1.09 and 1.06 for $^{147}Pm,\;^{204}Tl\;and\;^{90}Sr/^{90}Y$ beta rays, respectively. The evaluated values for angular responses were $0.93{\pm}0.03\;(^{147}Pm),\;0.94{\pm}0.04\;(^{204}Tl),\;and\;0.92{\pm}0.05\;(^{90}Sr/^{90}Y)$. The results satisfied well a proposed ISO Standard for beta ray dosimeters.

• Clean Technology
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• v.14 no.2
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• pp.87-94
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• 2008

The catalytic properties of large pore zeolite (mordenite, beta, and Y) with 12-membered rings were comparatively evaluated in the synthesis of diethylamines from ethanol amination. The number of strong acid sites, which obviously promoted the formation of mono- and diethylamines, was decreased with the increase of Si/Al ratio of the zeolites that were used. H-beta and H-Y zeolites with multidimensional pore channels favorably formed diethylether by the dimerization of ethanol, due to their large cage volumes and low acid strength. On the other hand, H-mordenite which has one dimensional straight channel was shown to be suitable for the formation of mono- and diethylamine which are well known as the useful intermediates of fine chemicals.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.173-182
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• 2003

A prototype liquid scillatillator system for measurement of multiple beta-labeled mixtures was developed and its characteristic was investigated. The signal processing system consists of two photomultiplier tubes and the coincident count circuit. The characteristic of the system was analyzed using 4 beta-labeled samples $(^3H,\;^{14}C,\;^{36}Cl\;and\;^{90}Sr)$. Beta spectra from the samples were obtained without radiation shielding, and the detection limits for each nuclides were estimated based on the spectra. The estimated detection limits were compared to the legal regulation values. It is found that the liquid radioactive nuclides are detectable well below the legal regulation values.