• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.262-268
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• 2022

This paper introduces a novel concept of the pulsed neutron facility (PNF) for maximizing the production of the thermal neutrons and its application to medical use based on prompt gamma neutron activation analysis (PGNAA) using Monte Carlo simulations. The PNF consists of a compact D-T neutron generator, a graphite pile, and a detection system using Cadmium telluride (CdTe) detector arrays. The configuration of fuel pins in the graphite monolith and the design and materials for the moderating layer were studied to optimize the thermal neutron yields. Biological samples - normal and cancerous breast tissues - including chlorine, a trace element, were used to investigate the sensitivity of the characteristic γ-rays by neutron-trace material interactions and the detector responses of multiple particles. Around 90 % of neutrons emitted from a deuterium-tritium (D-T) neutron generator thermalized as they passed through the graphite stockpile. The thermal neutrons captured the chlorines in the samples, then the characteristic γ-rays with specific energy levels of 6.12, 7.80 and 8.58 MeV were emitted. Since the concentration of chlorine in the cancerous tissue is twice that in the normal tissue, the count ratio of the characteristic g-rays of the cancerous tissue over the normal tissue is approximately 2.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.113-122
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• 2015

This study was carried out to investigate the characterization of cadmium adsorption by cellulose hydrogel and aerogel. Hydrogel and aerogel were made from ashless pulp dissolved in alkali hydroxide-urea aqueous solution and manufactured in film and bead types. After regeneration of cellulose, hydrogel went through the process of substitution of organic solvent and freeze-dry in order to make aerogel. SEM was used to analyze the microstructure of hydrogel and aerogel. Experiment was conducted in various concentrations and pH conditions to find out the characteristic of cadmium adsorption. After that, EDS was used to identify existence and distribution of cadmium in hydrogel and aerogel. The result from comparisons of cadmium adsorption shows that bead type aerogel has the maximum cadmium adsorption and film type hydrogel has the minimum cadmium adsorption.

• Journal of Species Research
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• v.3 no.1
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• pp.27-34
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• 2014

Two species of Tortanus (Eutortanus) are newly recorded from shallow Korean waters: T. (E.) vermiculus Shen, 1955 and T. (E.) komachi Itoh, Ohtsuka and Sato, 2001. As a result of this study, five species are reported in the subgenus of the family Tortanidae in Korea. The sequence of cytochrome c oxidase subunit 1 (CO1) is also provided as a molecular characteristic.

• Journal of Environmental Science International
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• v.22 no.9
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• pp.1141-1152
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• 2013

Insect fauna were surveyed in 2011 at Ungok wetland, Obeygol, located in Gochang, Jeonbuk, Korea. In total, 149 species belonging to 11 orders and 57 families were surveyed. Among them, Lepidopterans composed 23.5% (35 species) of the total insect numbers surveyed, comprising the most abundant group, and followed by Coleoptera, Hemiptera, and Odonata with a composition of 22.1% (33 species), 17.4% (26 species), and 10.1% (15 species), respectively. Bothrogonia japonica Ishihara was the most dominant species, and followed by Gastrophysa atrocyanea Motschulsky and Celastrina argiolus (Linnaeus). Phytophagous insects accounted for 60 percent of the total species. Dominance index was the highest in spring by 0.21. Diversity, richness, and evenness indices were the highest in summer by 4.07, 11.84 and 0.96, respectively. In the study area, the legally-protect species were grouped into five groups; 9 export-restricted species, 17 endemic species, 28 indicator species, 1 climate-sensitive biological indicator and 3 southern characteristic species. Additionally, twenty forest insect pest species were surveyed, belonging to 5 orders and 15 families. Therefore, it is required to conduct long-term monitoring and appropriate management based on the ecological characteristic of the habitats to continuously conserve and maintain of wetland.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.346-350
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• 1992

To investigate characteristic volatile components in Korean traditional soy sauce, this experiments were carried out. Whole volatile components were extracted by simultaneous steam distillation-extraction apparatus. The components of neutral fraction, emitting soy sauce-like odor, were fractionated from whole volatile components, and concentrated at atmosphere pressure, and then carried out GC-sniff evaluation and GC-fractionating collection by preparative gas chromatograph attached fraction collector APP-5. The GC-collected components were identified by GC/MS. The results were as follows; The component, emitting disagreeable odor, was identified as 3-methyl-1-butanol. The components, emitting soy sauce-like odor, were identified as dimethyl trisulfide, benzeneacetaldehyde, benzeneethanol.

• Journal of Biomedical Engineering Research
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• v.10 no.3
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• pp.223-228
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• 1989

In this paper, the computerized interpretation of the analytical chemical data, especially GC/MS data, was performed for the purpose of prescreening of the target compounds. First, the data from the analytical instrument was analyzed to get the information about the retention time of the ISTD and the time inteval between the records. Second, the identification of the characteristic ion peaks was performed by calculating the ratio of the heights and the relative slope sensitivity of the characteristic mass abundance.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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• pp.510-515
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• 2009

In this paper, variable characteristic ratio algorithm based on oscillometric method is proposed to enhance the accuracy of blood pressure measurement. We combined the slope-based approach and fuzzy inference technique to change the characteristic ratios of height-based method. The proposed algorithm was assessed on 255 measurements from 85 subjects and compared with the conventional height-based algorithm. The testing results showed that the developed algorithm achieved an overall grade A for both systolic and diastolic blood pressures according to the BHS protocol. And, mean standard deviation between the observers and the developed algorithm were 5.71mmHg and 6.29mmHg for systolic and diastolic pressures respectively, which also fulfilled the AAMI criteria. In conclusion, this algorithm was successfully developed and recommended for further clinical trials with the wider adult population.

• Journal of Forest and Environmental Science
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• v.35 no.4
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• pp.263-267
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• 2019

Two newly recorded small orb weavers, Araneus yasudai Tanikawa, 2001 and Neoscona flavida sp. nov., with characteristic epigynal scape belonging to Araneidae are described with measurements and morphological illustrations from Korea. Both species were collected with sweep net between shrubs and bushes in mountain forest and between reeds in reclaimed land, respectively.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.212-218
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• 2006

Three out of fourteen Microcystis-dominant cyanobacterial blooms in Central India were found to be toxic to mice ($LD_{50}$ ranging from 35-450 mg bloom dry mass/kg body weight). The liver architecture of the treated mice showed characteristic symptoms of hepatotoxicity relative to the untreated controls, with increased enzyme activities of serum lactate dehydrogenase (LDH), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), and serum glutamate pyruvate transaminase (SGPT). RP-HPLC revealed the presence of microcystin-LR, microcystin-RR, and desmethyl microcystin-RR in the given region to maximum amounts of 390, 1,030, and $860{\mu}g/g$ bloom dry weight, respectively, corresponding to a maximum of 2.8 mg/l microcystin-LR in the lake water. Further confirmation of the microcystin variants was conducted using a MALDI-TOF MS analysis.

• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.34-44
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• 1998

Living organisms are influenced by many external rhythms and they have adapted their physiology to periodically changing conditions. These adaptive strategies are controlled by endogenous innate programs of behavior and physiology which are determined by external signals ("Zeitgeber"). There are many biological rhythms, each with its own characteristic functional adaptation. Among them, the presence of endogenous time control of feeding and drinking becomes obvious. There are increasing evidences that the control of food intake, food selection, and drinking are regulated by the endogenous rhythms including a circadian rhythm. However, there have been many restrictions in understanding the endogenous control of food intake itself and its mechanism. To broaden our know ledges of the endogenous time control of feeding and drinking, the author reviwed the characteristics of the endogenous timing for food intake, the influence of circadian pacemakers and food-entrainable oscillators, the interaction between the circadian control and the external and internal conditions in the control of food intake, the conseqences of feeding, the circadian control of food selection, and the biological cycles in energy balance.