• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.4
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• pp.370-377
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• 1995

The recombination of oxygen and nitrogen atoms on the surfaces of two coating m materials of the Space Shuttle Orbiter (SSO), a reaction cured glass (RCG) and a spinel (C742), was investigated. The recombination probability, $\gamma$, i.e., the probability that atoms im p pinging on the surface will recombine, was measured in a diffusion reactor. Value of $\gamma$ for oxy g gen atom on C742 ($3 {\times} 10^{-2}$) was much higher than that on RCG ($4 {\times} 10^{-4}$) at the tempera t ture of SSO re-entry (ca. 1000K). The higher value of $\gamma$ on C742 indicates a higher number d density of active sites than RCG. It suggests the possibility of designing less active surfaces by i inducing the desorption at lower temperature.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.526-532
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• 2009

Quenching mechanisms and kinetics of $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol in photosensitized oxidation of lard were studied. Lard at 0.03, 0.07, 0.11, and 0.3 M in methylene chloride containing $4.4{\times}10^{-6}\;M$ chlorophyll and 0, 0.1, 0.3, and 0.6 mM $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol were stored under light for 4 hr, respectively. Oxidation was determined by headspace oxygen and peroxide value. Tocopherols prevented the photosensitized oxidation of lard (p<0.05). Steady state kinetic study showed that $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol prevented the photosensitized oxidation of lard by quenching singlet oxygen. Singlet oxygen quenching rates of $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol by headspace oxygen depletion were 1.86, 2.39, 2.47, and $2.11{\times}10^7/M/sec$, respectively. The quenching rates of $\alpha$-, $\beta$-, $\gamma$-, and $\delta$-tocopherol by peroxide value were 1.42, 1.11, 0.97, and $0.42{\times}10^7/M/sec$, respectively. The quenching rates of tocopherols were slightly different depending on the measurements of oxidation.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.737-740
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• 2002

To determine the relations between antihypertensive effect and ${\gamma}-aminobutyric$ acid, mycelial weight and pigment of Monascus, ethanol koji extracts were prepared from Monascus koji and each of three grade was classified based on ${\gamma}-aminobutyric$ acid content, glucosamine content and hue angle value, respectively. Each extract was orally administrated on male spontaneously hypertensive rats and its antihypertensive effect was compared. Most of koji extracts showed antihypertensive activity regardless of their ${\gamma}-aminobutyric$ acid content, glucosamine content or hue angle value. Therefore, hypotensive activity of koji extract was not dependent on above three components.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.2
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• pp.61-68
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• 2012

This paper describes a normalized numeric image descriptor used to assess the luminance and contrast of the image. The proposed image descriptor used the each pixel data as weighted value of the probability density function (PDF) and defined by normalization in order to objective represent. The proposed image numeric descriptor can be used to the adaptive gamma process because it suggests the objective basis of the gamma value selection.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.26 no.3
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• pp.156-184
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• 2022

In this article, we propose a novel variational model for restoring color images corrupted by mixed multiplicative Gamma noise and additive Gaussian noise. The model involves a data-fidelity term that characterizes the mixed noise as an infimal convolution of two noise distributions and the saturation-value total variation (SVTV) regularization. The data-fidelity term facilitates suitable separation of the multiplicative Gamma and Gaussian noise components, promoting simultaneous elimination of the mixed noise. Furthermore, the SVTV regularization enables adequate denoising of homogeneous regions, while maintaining edges and details and diminishing the color artifacts induced by noise. To solve the proposed nonconvex model, we exploit an alternating minimization approach, and then the alternating direction method of multipliers is adopted for solving subproblems. This contributes to an efficient iterative algorithm. The experimental results demonstrate the superior performance of the proposed model compared to other existing or related models, with regard to visual inspection and image quality measurements.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.10
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• pp.1378-1383
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• 2011

This study investigated the antioxidant activity of ethanolic extracts of 1~20 kGy-gamma irradiated flowering cherry fruit (Prunus serrulata L. var. spontanea Max. wils.). The total phenolic compound content was highest (30.35 mg/g) in the 10 kGy sample, but there was no consistent trend matching the increase or decrease of gamma irradiation. Radical scavenging activity using DPPH (2,2-diphenyl-1-picrylhydrazyl) showed that gamma-irradiated samples were better than non-irradiated samples and that the 10 kGy-gamma irradiated sample was the best ($IC_{50}$ 327.52 ppm). In reducing power, gamma-irradiated samples induced higher activities than non-irradiated samples at concentrations below 2.5 mg/mL, and the sample with the highest activity was the 20 kGy-gamma irradiated sample. In nitrite-scavenging ability, both gamma-irradiated and non-irradiated samples showed high activity (73~94%) at pH 1.2, 3.0, and 4.2. Also, the nitrite-scavenging ability of gamma-irradiated samples was significantly different from that of the control at pH 1.2. The FRAP value of the 3 kGy-irradiated sample also showed the highest value of 0.38 mM. Our results indicate that gamma irradiating the ethanolic extracts of flowering cherry fruit increases the antioxidant activity at some of the radiation doses. Therefore, it suggests that gamma irradiation could increase biological activity and be used effectively in food manufacturing and related industries.

• Korean Journal of Veterinary Research
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• v.41 no.3
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• pp.387-393
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• 2001

The chemical composition of fish feeds(mackerel, gizzard shad, shrimp and formula feed) were analyzed and compared with those of untreated and irradiated (5 kGy) feeds, and the effects of gamma irradiation (5 kGy) and butylated hydroxyanisole (BHA, 200ppm) on feeds spoilage were investigated by determination of thiobarbituric acid (TBA) value and peroxide value for 14 days at $20^{\circ}C$, $4^{\circ}C$ or $-20^{\circ}C$. Crude protein, crude lipid, crude fiber, crude ash and nitrogen free extract were not significantly changed by gamma irradiation with the dose of 5 kGy. Immediately gamma irradiation increased the initiative oxidation of feeds as expected. But BHA was found to be greatly effective in minimizing the radiation-induced peroxidation (p<0.05). The TBA value and peroxide value increased with the elapse of the storage period. The level of lipid oxidation was increased depending on the rise in storage temperature. But the additions of BHA inhibited the lipid oxidation (p<0.05).

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.775-780
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• 2014

Objectives: TCR-gamma-delta+T cells (${\gamma}{\delta}$ T cells) are non-conventional T lymphocytes that can recognize and eradicate tumor cells. Our previous studies showed that infiltration and function of ${\gamma}{\delta}$ T cells were substantially attenuated in hepatocellular carcinoma (HCC). However, their prognostic value was not clarified. Methods: The association between ${\gamma}{\delta}$ T cells and the clinical outcomes was determined by immunohistochemistry (IHC) in a HCC patient cohort (n = 342). Results:Immunohistochemistry showed decreased infiltration of ${\gamma}{\delta}$ T cells in tumoral tissues compared with paired peritumoral tissues. The counts of ${\gamma}{\delta}$ T cells in peritumoral tissues were negatively correlated with tumor size (P = 0.005). Survival analysis showed that the levels of peritumoral ${\gamma}{\delta}$T cells were related to both time to recurrence (TTR) and overall survival (OS) (P = 0.010 and P = 0.036, respectively) in univariate analysis, and related to TTR in multivariate analysis (P = 0.014, H.R. [95% CI] = 0.682 [0.502-0.927]). Furthermore, the level of peritumoral ${\gamma}{\delta}$ T cells showed independent prognostic value for TTR in Barcelona Clinic Liver Cancer (BCLC) stage A patients (P = 0.038, H.R. [95% CI] = 0.727 [0.537-0.984]). However, tumoral ${\gamma}{\delta}$ T cells did not show independent prognostic value for either TTR or OS in HCC patients. Conclusions: Low counts of ${\gamma}{\delta}$ T cells in peritumoral liver tissue are related to a higher incidence of recurrence in HCC and can predict postoperative recurrence, especially in those with early-stage HCC.

• Journal of the Korean Society for Heat Treatment
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• v.30 no.5
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• pp.215-221
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• 2017

The effect of austenitizing temperature on the degree of carbides re-solutionizing, mean graine size, hardness and the volume fraction of retaind austenite ($V_{\gamma}$) etc., has been studied by means of metallography, X-ray diffractometry and hardness measurement in STD 11 tool steel. As austenitizing temperature increases, the amount of alloying elements which is re-dissolved into matrix increases, resulting in increase of $V_{\gamma}$, due to the chemical stabilization of austenite. The Vickers hardness value decreases with increasing austenitizing temperature, which is attributed to grain size as well the volume fractions of $V_{\gamma}$ and carbides. Theoretical diffraction intensity of (200) ${\alpha}^{\prime}$, (211) ${\alpha}^{\prime}$ (200) ${\gamma}$ and (220) ${\gamma}$ peaks obtained by $CuK_{\alpha}$ chracteristics X-ray (${\lambda}=0.15429nm$) was calculated, and quantitative analysis of $V_{\gamma}$ could be carried out by X-ray diffraction method. The resultant value is well coincided with the value obtained by image analysis method. When the quenched specimen is tempered above $200{\sim}400^{\circ}C$ for 30 min, the transition carbides i.e., MC and $M_2C$ in the size of about 20 nm begin to precipitate at $300^{\circ}C$.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.280-289
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• 1998

Background: It is sometimes difficult to differentiate tuberculous pleural effusion from malignant pleural effusion by clinical symptoms, signs, by routine tests of pleural fluid, and by pathologic studies. And recently, it was discovered that cytokines such as IL-2, IFN-$\gamma$, TNF-$\alpha$ are elevated in tuberculous pleural fluid, and there have been several attempts to diagnose tuberculous pleural effusion by using these immunological mediators. There are several studies regarding the diagnostic value of IFN-$\gamma$, and there are two studies in Korea. But the diagnostic values of IFN-$\gamma$ in these studies were slightly lower than those in other countries. To compare the diagnostic value of IFN-$\gamma$ with those of CEA and ADA, and to determine the sensitivity and specificity of IFN-$\gamma$ in Korean, we mesured IFN-$\gamma$, CEA level and ADA activity in pleural effusions. Methods: ADA activity, IFN-$\gamma$ level and CEA level as well as cell count, differential count, and biochemical assays such as protein content and lactate dehydrogenase were measured in 40 cases of tuberculous pleuritis and 42 cases of malignant pleural effusion. Results: Tuberculous pleural fluid showed higher levels of IFN-$\gamma$ and ADA ($832.6{\pm}357.2$ pg/ml and $82.5{\pm}25.9$ U/L, respectively) than those of malignant pleural effusion ($2.6{\pm}8.0$ pg/ml and $19.2{\pm}10.9$ U/L, respectively) (p<0.01). Malignant pleural effusions showed higher median value (102.2 ng/ml) than tubercalous pleural effusions (1.8 ng/ml) (p<0.01). The sensitivities of IFN-$\gamma$, ADA, CEA were 0.97, 0.87, 0.67 and the specificities of IFN-$\gamma$, ADA, CEA were 1.0, 0.97, 1.0, respectively. There was no significant correlation between ADA activity and IFN-$\gamma$ level. Conclusion: This study showed that IFN-$\gamma$ test would be a very useful clinical test for differential diagnosis of tuberculous pleuritis and malignant pleural effusion because it is very sensitive and specific, although it is an expensive test.