• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.2
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• pp.108-111
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• 2015

Purpose Lately, in accordance with the increasing interest about Healthcare accreditation program and International laboratory accreditation scheme, requirements about the instrument quality management are gradually taking shape. In nuclear medicine In vitro laboratory, the most typical instruments are multi detector gamma counter and automatic dispensing system. Each laboratory continue with the quality control adequate for circumstances. The purpose of this study is to application and establish the new Calibrator[I-125]Set which is efficient at standardization of equipment quality management. Materials and Methods Deviation between detectors were measured with 12 solid samples of the Calibrator[I-125]Set. their activities differ from each other by less than 1%. Multi detector gamma counters are GAMMA-10;Shinjin medics. Inc, Goyansi, Korea(Gamma counter A), SR300;Stratec biomedical systems AG, Gewerbestr, Germany(Gamma counter B) and COBRA II; Packard Instrument Co. Inc, Meriden, USA(Gamma counter C). Evaluation of two automatic dispensing system used A, B liquid tracer of the Calibrator[I-125]Set. After dispensing and counting, calculated using the ratio of the measured value and proposed value. We used solution A for 20, 25ul and solution B for 50, 100ul. Method of data analysis and reference range was provided by kit documentation. Furthermore, we could calculate our counter efficiency indirectly. Results The CV(%) of measured values by Gamma counter A, B, C are 0.34, 0.70, 1.30. Calculated value are 1.05314, 2.10419, 4.08485. Provided reference range is less than 3. A dispensing system's calculated values are 0.986, 0.989, 1.023, 1.017 and B are 0.874, 0.725, 1.021, 0.904. Provided reference range is from 0.95 to 1.05. Also, counter's efficiency are 74.18, 72.79, 74.32% at counter A, B, C and efficiency of the one detector counter is 79.26%. Conclusion If using this Calibrator[I-125]Set after verifying whether quality assurance, is applicable to equipment quality management on behalf of the role of gold standard.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.8
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• pp.1112-1117
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• 2010

This study was conducted to evaluate and compare the quality changes of commercial sliced and pizza cheeses processed by gamma and electron beam irradiation. The $L^*$-value of sliced and pizza cheeses decreased and the $a^*$-value decreased only in pizza cheese by both irradiation sources. There was no change in pH. There was no difference in 2-thiobarbituric acid reactive substances (TBARS) value between non-irradiated and irradiated samples at a dose of 3 kGy or less (p<0.05). However, both irradiation sources resulted in increased TBARS value in sliced and pizza cheeses at 5 kGy. Sensory evaluation revealed that irradiation influenced odor, taste and overall acceptability of both cheeses and may cause the limitation of consumers' acceptance for irradiated cheese products. Results indicate that both gamma and electron beam irradiations with less than 3 kGy may not influence significantly the physicochemical quality of sliced and pizza cheeses. However, to meet a market requirement, a method to overcome the sensory deterioration of cheeses should be developed and applied.

• Journal of Radiation Industry
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• v.5 no.4
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• pp.383-391
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• 2011

This study was conducted to investigate the applicability of gamma irradiation for improving the quality of paprika and Japanese apricot extract-treated nitrite free pork jerky. Pork jerky was gamma-irradiated at 0, 3, 5, 7 and 10 kGy and physiochemical properties such as proximate composition, 2-thiobarbituric acid (TBARS) values, color stability, texture, and sensory property were then evaluated. The results showed that the treatment of paprika and Japanese apricot extract to the pork jerky increased Hunter color value and texture property and at the same time decreased TBARS values. When gamma irradiated, natural pigment extract-treated pork jerky did not produce any change in its proximate composition (moisture, crude protein, crude lipid contents), and TBARS values. However, the redness (a-value) of pork jerky increased as the irradiation dose increased, whereas shear force of pork jerky was decreased. Sensory result showed that gamma irradiation induced to decrease the sensory scores. Therefore, these results suggest that gamma irradiation and the addition of paprika and Japanese apricot extracts could be an effective mean to improve color and texture of restructured pork jerky without use of nitrite.

• Journal of Astronomy and Space Sciences
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• v.19 no.1
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• pp.1-6
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• 2002

Recently, one interesting possibility is proposed that a magnetar can be a progenitor of short and hard gamma-ray bursts (GRBs). If this is true, one may expect that the short and hard GRBs, at least some of GRBs in this class, are distributed in the Euclidean space and that the angular position of these GRBs is correlated with galaxy clusters. Even though it is reported that the correlation is statistically marginal, the observed value of < $V/V_{max}$ > deviates from the Euclidean value. The latter fact is often used as evidence against a local extragalactic origin for short GRB class. We demonstrate that GRB sample of which the value of < $V/V_{max}$ > deviates from the Euclidean value can be spatially confined within the low value of z. We select very short bursts (TgO < 0.3 sec) from the BATSE 4B catalog. The value of < $V/V_{max}$ > of the short bursts is 0.4459. Considering a conic-beam and a cylindrical beam for the luminosity function, we deduce the corresponding spatial distribution of the GRB sources. We also calculate the fraction of bursts whose redshifts are larger than a certain redshift z', i.e. f>z'. We find that GRBs may be distributed near to us, despite the non-Euclidean value of < $V/V_{max}$ >. A broad and uniform beam pattern seems compatible with the magnetar model in that the magnetar model requires a small $z_{max}$.

• Journal of Korean Neurosurgical Society
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• v.64 no.1
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• pp.13-22
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• 2021

Objective : High precision and accuracy are expected in gamma knife radiosurgery treatment. Because of the requirement of clinically applying complex radiation and dose gradients together with a rapid radiation decline, a dedicated quality assurance program is required to maintain the radiation dosimetry and geometric accuracy and to reduce all associated risk factors. This study investigates the validity of Leksell Gamma plan (LGP)10.1.1 system of 5th generation Gamma Knife Perfexion as modified variable ellipsoid modeling technique (VEMT) method. Methods : To verify LGP10.1.1 system, we compare the treatment plan program system of the Gamma Knife Perfexion, that is, the LGP, with the calculated value of the proposed modified VEMT program. To verify a modified VEMT method, we compare the distributions of the dose of Gamma Knife Perfexion measured by Gafchromic EBT3 and EBT-XD films. For verification, the center of an 80 mm radius solid water phantom is placed in the center of all sectors positioned at 16 mm, 4 mm and 8 mm; that is, the dose distribution is similar to the method used in the x, y, and z directions by the VEMT. The dose distribution in the axial direction is compared and analyzed based on Full-Width-of-Half-Maximum (FWHM) evaluation. Results : The dose profile distribution was evaluated by FWHM, and it showed an average difference of 0.104 mm for the LGP value and 0.130 mm for the EBT-XD film. Conclusion : The modified VEMT yielded consistent results in the two processes. The use of the modified VEMT as a verification tool can enable the system to stably test and operate the Gamma Knife Perfexion treatment planning system.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.732-737
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• 2005

The combinational effect of gamma irradiation and moist heating on the trypsin inhibitor activity (TIA) in soaked and dried soybeans was evaluated by measuring the inhibition using N-benzoyl-DL-arginine-p-nitroanilide (BAPNA) as substrate. Gamma irradiation significantly decreased the TIA level in soybean at doses above 5 kGy, and the $ID_{50}$ (the gamma irradiation dose required to reach 50% inhibition) value for TIA was 13.53 kGy. Soaking prior to gamma irradiation significantly lowered the $ID_{50}$ to 8.44 kGy, and the soaking process enhanced the efficiency to inactivate TIA by as much as 48%. When soaking prior to gamma irradiation was followed by subsequent mild heating ($60^{\circ}C$) process, the $IT_{50}$ (heating time required to reach the 50% inhibition of TIA) value at even 1 kGy (5.28 min) was greatly reduced by over 50% compared to the level for the no-soaking process. In addition, the activation energy of soaking prior to gamma irradiation at 1 kGy was 2.45 kcal/mole, which was also about 50% lower than the 5.10 kcal/mole of dried soybean gamma-irradiated. Based on these results, soaking prior to gamma irradiation is an effective method for TIA inhibition. Furthermore, a combination of two or more processing methods such as soaking, heating and gamma irradiation is much more effective than any single processing method.

• Journal of the Chungcheong Mathematical Society
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• v.27 no.1
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• pp.9-16
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• 2014

Let $\mathbb{A}=\mathbb{F}_q[T]$ be a polynomial ring over $\mathbb{F}_q$. In this paper we determine an asymptotic mean value of quadratic Dirich-let L-functions L(s, ${\chi}_{{\gamma}D}$) at the central point s=$\frac{1}{2}$, where D runs over all monic square-free polynomials of even degree in $\mathbb{A}$ and ${\gamma}$ is a generator of $\mathbb{F}_q^*$.

• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3317-3323
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• 2022

Half Value Layer calculations theoretically need prior specification of linear attenuation calculations, since the HVL value is derived by dividing ln(2) by the linear attenuation coefficient. The purpose of this study was to establish a direct computational model for determining HVL, a vital parameter in nuclear radiation safety studies and shielding material design. Accordingly, a typical gamma-ray transmission setup has been modeled using MCNPX (version 2.4.0) general-purpose Monte Carlo code. The MCNPX code's INPUT file was designed with two detection locations for primary and secondary gamma-rays, as well as attenuator material between those detectors. Next, Half Value Layer values of some well-known gamma-ray shielding materials such as lead and ordinary concrete have been calculated throughout a broad gamma-ray energy range. The outcomes were then compared to data from the National Institute of Standards and Technology. The Half Value Layer values obtained from MCNPX were reported to be highly compatible with the HVL values obtained from the NIST standard database. Our results indicate that the developed INPUT file may be utilized for direct computations of Half Value Layer values for nuclear safety assessments as well as medical radiation applications. In conclusion, advanced simulation methods such as the Monte Carlo code are very powerful and useful instruments that should be considered for daily radiation safety measures. The modeled MCNPX input file will be provided to the scientific community upon reasonable request.

• Journal of Environmental Impact Assessment
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• v.23 no.4
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• pp.285-295
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• 2014

In this study, we analyzed probability distribution of EMCs (Event Mean Concentration) of COD, TOC, T-N, T-P and SS from rice paddy fields and compared the mean values of observed EMCs and the median values of estimated EMCs ($EMC_{50}$) through probability distribution. The field monitoring was conducted during a period of four crop-years (from May 1, 2008, to September 30. 2011) in a rice cultivation area located in Emda-myun, Hampyeong gun, Jeollanam-do, Korea. Four probability distributions such as Normal, Log-normal, Gamma, and Weibull distribution were used to fit values of EMCs from rice paddy fields. Our results showed that the applicable probability distributions were Normal, Log-normal, and Gamma distribution for COD, and Normal, Log- Normal, Gamma and Weibull distribution for T-N, and Log-normal, Gamma and Weibull distribution for T-P and TOC, and Log-normal and Gamma distribution for SS. Log-normal and Gamma distributions were acceptable for EMCs of all water quality constituents(COD, TOC, T-N, T-P and SS). Meanwhile, mean value of observed COD was similar to median value estimated by the gamma distribution, and TOC, T-N, T-P, and SS were similar to median value estimated by log-normal distribution, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1708-1714
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• 2015

Fermented red ginseng concentrate is known as a healthy food source, whereas it has off-flavor such as bitterness and sour flavor based on fermentation. ${\beta}$- and ${\gamma}$-cyclodextrin (CD) were used to encapsulate the off-flavor of fermented red ginseng concentrate by using response surface methodology design on ${\beta}$- and ${\gamma}-CD$ combination. The reducing effects were analyzed by sensory evaluation for bitter and sour tastes, ginsenoside Rb1, and total acidity. The optimized mixing ratio of ${\beta}$- and ${\gamma}-CD$ for reducing bitterness was the least expected value of 2.07 at ${\beta}-CD$ 3.74% versus the soluble solid content of fermented red ginseng concentrate and the ${\gamma}-CD$ 20.63% mixture. The encapsulation effects of ginsenoside Rb1 were the most expected value of 96.75% at ${\beta}-CD$ 3.47% and ${\gamma}-CD$ 19.89% mixture. The encapsulation effects of sour taste were the least expected value of 5.63 at ${\beta}-CD$ 9.34% and ${\gamma}-CD$ 9.96% mixture. The encapsulation effects of lactic acid were the most expected value of 67.73% at ${\beta}-CD$ 16.0% and ${\gamma}-CD$ 13.18% mixture. Based on encapsulation and each optimized combination, the most effective entrapping ${\beta}$-and ${\gamma}-CD$ combination ratio was ${\beta}-CD$ 10% and ${\gamma}-CD$ 13%.