• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.224-230
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• 2013

BACKGROUND: Perchlorate(${ClO_4}^-$) is an anion that is extremely water-soluble and environmentally stable. It mostly exists in the form of sodium perchlorate, ammonium perchlorate and potassium perchlorate which are used in rocket fuels, propellants, ignitable sources, air bag inflation systems and explosives. Perchlorate can be taken into the thyroid glands and interfere with iodide uptake. The determination of perchlorate in agricultural products is important due to its potential health impact on humans. The objective of this study was to determine the perchlorate concentrations in the samples of various agricultural products and soils. METHODS AND RESULTS: In this study, samples of cereal(Rice, Barley, Corn, Bean), vegetable(Spinach, Lettuce, Sesame, Chives, Chili, Pumpkin, Tomato), fruit(Apple, Pear, Tangerine, Grape) were analyzed for perchlorate contents. Perchlorate concentrations were analyzed by liquid chromatography-tandem mass spectrometry. The results showed that agricultural products respectively contained perchlorate concentrations in the range of : cereals N.D.~$7.46{\mu}g/kg$, vegetables $0.52{\sim}23.06{\mu}g/kg$, fruits $0.19{\sim}2.66{\mu}g/kg$. Bioconcentration factor was in the order of : vegetables > cereals > fruits. Bioconcentration factor was highest follwed by Sesame 37.88, Corn 21.51, Spinach 10.57, Tangerine 4.39, Chives 2.89 and Lettuce 1.90. The recoveries of perchlorate from spiked agricultural products and soils ranged from 87.72~111.26% and 102.09~111.23%. CONCLUSION(S): The health risk assessment results obtained in this study are lower than the RfD(Reference Dose, 0.0007 mg/kg/body weight/day) value as suggested by the Integrated Risk Information System(US IRIS). Our results indicate that, people currently exposed to perchlorate from agricultural products consumption are considered as safe.

• Korean Journal of Digital Imaging in Medicine
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• v.9 no.1
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• pp.37-43
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• 2007

1. Purpose : This study is to present effective exposure conditions to acquire the best image of simple abdomen in Film Screen (F.S) system and Computed Radiography (C.R) system. 2. Method : In the F.S system, while an exposure condition was fixed as 70kVp, images of a patients simple abdomen were taken under the different mAs exposure conditions. Among these images, the best one was chosen by radiologists and radiological technologists. In the C.R system, the best image of the same patient was acquired with the same method from the F.S system. Both characteristic curves from F.S system and C.R system were analyzed. 3. Results : In the F.S system, the best exposure condition of simple abdomen was 70kVp and 20mAs. In the CR system, with the fixed condition at 70kVp, the image densities of human organs, such as liver, kidney, spleen, psoas muscle, lumbar spine body and iliac crest, were almost same despite different environments (3.2mAs, 8mAs, 12mAs, 16mAs and 20mAs). However, when the exposure conditions were over or under (below) 12mAs, the images between the abdominal wall and the directly exposed part became blurred because the gap of density was decreased. In the C.R system, while the volume of mAs was decreased, an artifact of quantum mottle was increased. 4. Conclusion : This study shows that the exposure condition in the C.R system can be reduced 40% than in the F.S system. This paper concluded that when the exposure conditions are set in CR environment, after the analysis of equipment character, such as image processing system(EDR : Exposure Data Recognition processing), PACS and so on, the high quality of image with maximum information can be acquired with a minimum exposure dose.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.1
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• pp.43-48
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• 2010

This study was conducted to compare the chemical composition, dry matter digestibility (DMD), dry matter intake, and utilization of nitrogen and energy of dairy goats (Saanen), when fed on imported timothy hay (IT), mixture grass hay (MG) and native grass hay (NG), respectively. The experimental trials were conducted from April, 2008 to December, 2008 at the environmental controlled barn of Chungnam National University. Twelve dairy goats (Saanen) were selected which had nearly the same body weight (24.2kg, male). The content of crude protein (CP) of MG hay was higher than that of other diets (p<0.05), but the contents of NDF, ADF, cellulose and lignin of IT and NG diet were higher than those of MG diet (p<0.05). The voluntary DM intake of dairy goats fed with herbage from MG diet (30.7/$BW_{kg}$/day) was higher than that of other diets, but no significant difference was observed between that of IT diet and NG diet (p>0.05). The DMD of MG diet (69.8%) was higher than that of NG diet (62.2%) and IT diet (60.8%) (p<0.05), but no significant difference was observed between that of IT diet and NG diet (p>0.05). In nitrogen utilization, the apparently digested N %, retained % and biological value of dairy goats fed with herbage from MG diet were higher and TG diet was lower (p<0.05). In energy utilization, digestible energy and the energy of apparently digested minus urinary losses of MG diet were higher than those of IT diet and NG diet (p<0.05), but no significant difference was found between IT diet and NG diet (p>0.05). Based on the results, the dry matter intake, DMD and utilization of nitrogen and energy of dairy goats of MG were higher than those of IT diet and NG diet (p<0.05), the DMD and biological value (%) of NG diet was higher than that of IT diet (p<0.05).

• Korean journal of applied entomology
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• v.49 no.3
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• pp.219-226
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• 2010

This paper presents the occurrence and damage characteristics of the rice leaf-folder populations in the paddy fields of Dangsu-dong, Suwon from 2004 to 2007, and also reports the insecticide response of rice leaf-folder populations, which were collected from 2005 to 2006 in Korea and Vietnam. Laboratory measurements of the head capsule width and body length data enabled the identification of the rice leaf-folder larva stages collected in the field. The rice leaf-folder population in Suwon from 2004 to 2007 has a clear pattern consisting of two different group: the low and high density years. During the low density years (2004 and 2006), only one adult peak was noted in late August, with the damaged-hill percent less than 10% in late July, and the damaged-leaf percent around 2% in September. In contrast, during the high density years (2005 and 2007), two adult peaks were noted in early August and mid-September, with the damaged-hill percent was around 30% in late July, and the damaged-leaf percent 15 to 30% in September, which was beyond the economic injury level of rice leaf-folder. High correlations existed between the occurrence of rice leaf-folder in late July and early August and damages to rice during September. Based on these results, we suggest that the information on the rice leaf-folder population monitored by the adult density or damaged-hill percent in late July and early August would be very useful for predicting the damages later in the season for aiding in decision-making for timely control. In addition, the regional populations of rice leaf-folder showed the similar responses to the insecticides tested: high susceptibility to IGRs (tebufenozide and methoxyfenozide) and organophosphates (chlorpyrifos-methyl, pyridaphenthion), but relatively low to cartap.

• Journal of Korean Neurosurgical Society
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• v.29 no.11
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• pp.1421-1428
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• 2000

Objectives : The aim of this study is to evaluate the sequential metabolic changes in experimental hydrocephalus and the clinical applicability to the diagnosis and prognosis of hydrocephalus using proton MR spectroscopy. Methods : Hydrocephalus was experimentally induced in 30 cats(2-3kg body weight) by injecting 1ml of sterile kaolin suspension(250mg/ml) into the cisterna magna. Proton MRS was performed with a 1.5 T MRI/MRS unit (Vision Plus, Siemens) at pre-treatment and at 1, 3, 7, 14, 21, and 28 days after the kaolin injection. PRESS(TR/TE＝1500/270msec) technique was employed. The major metabolites which include N-acetyl aspartate (NAA), creatine(Cr), choline(Cho), and lactate(Lac) were quantitatively analyzed and the relative concentrations ratios were evaluated. Multislice $T_2$-weighted images were also obtained using fast spin echo sequence(TR/TE＝ 2500/96msec) to monitor the morphologic changes along with progression of hydrocephalus. Results : Hydrocephalus was successfully induced in all 30 cats. Twenty five cats died within 3 days and one at the end of the second week. In all animals, the NAA/Cr ratios initially decreased during the acute stage. In 4 surviving cats, the NAA/Cr ratios initially decreased during the acute stage(<14 days) and then gradually increased to the prekaolin level as follows : pre-kaolin($1.49{\pm}0.04$), day 1($1.11{\pm}0.07$), day 7($1.17{\pm}0.04$), day 14($1.40{\pm}0.03$), day 21 ($1.46{\pm}0.06$), day 28($1.43{\pm}0.03$). These levels were relatively well correlated with the symptomatologic improvement. Lactate peak, which reflects the evidence of ischemia, did not appear throughout the entire period except in one case which expired at the end of the second week. Conclusions : The NAA/Cr ratio of the sequential proton MRS in kaolin-induced hydrocephalic cats reflects a metabolic aspect of the hydrocephalus at each stage. A decreased NAA level at the early stage is from both neuronal and axonal damage which may provide diagnostic information in the acute stage of hydrocephalus. In addition, the initial fall of NAA/Cr ratio and recovery in the late stage, when no lactate peak emerges, may suggest that the main insult of the parenchyma is not to the neuron itself but to the axon, which may be related to a good prognosis. However, emergence of the lactate peak and unrecoverable NAA/Cr at the end of the acute phase may be a poor prognostic factor. In the chronic stage, recovery of NAA/Cr ratio may provide a diagnostic clue for the differentiation between hydrocephalus and cortical atrophy.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.4
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• pp.332-340
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• 2016

Sunken ships cause damage to the environment due to the dispersal of fuel oil and harmful cargo goods in the hull. Since the sunken ship is mostly flooded by the seabed, it tends to be in a relatively stable condition. However, the heavy body, together with the load of remaining goods in the cargo hold, the constant contact with the seabed, and ocean currents and tidal waves, can affect dispersal of residual fuel oils out of the sunken ship. Corrosion of the sunken ship starts upon sinking, decreasing the thickness of the hull structure and sub-materials. Therefore, it is necessary to assess the structural stability against the potential breakdown of the sunken ship. Whilst evaluating the danger of the sunken ship, this result should be reflected in 'the possible discharge'. This study was undertaken to suggest a procedure for a step by step evaluation to assess the structural stability a sunken ship. The structural stability assessment to estimate the collapsibility of the hull was structure targeted at the sunken ship 'No. 7 HaeSung', which was classified as the prime example for the intensive management of sunken ships. This study was undertaken to suggest a procedure for a step by step evaluation to assess the structural stability a sunken ship and to propose a method to conduct a structural safety assessment that estimates the collapsibility of the hull by targeting the sunken ship 'No. 7 HaeSung',which was classified as the prime example for the intensive management of sunken ships. The collapsibility of the hull structure was estimated Based on the damage size of the hull structure, and the corrosion rate of the hull structure and sub-materials due to the seawater after sinking. It was confirmed that there was a low possibility of the total destruction of the hull structure at the current time. However, there is a high possibility in the potential failure of the hull structure due to increased rate of corrosion thereafter. Therefore, we believe continuous study on influence of corrosion and marine environment change to sunken ship's structural safety is necessary.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.1
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• pp.61-70
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• 2008

The object of this experiment was to investigate the food habits of sika deer fed with various roughage sources. The feeding trials were conducted at Chungnam National University and Unbong Animal Genetic Resources Station in 2007. The experimental roughages sources were five including 25 species in all; grass sources; 5 species(Lolium perenne, Festuca arundinacea, Poa pratensis, Agrostis alba and mixed grass), legume sources; 5 species(Trifolium pratense, Medicago sativa, Trifolium repens, Melilotus officinalis and Vicia villosa), browse sources; 5 species(Quercus serrata Thunb., Prunus jamasakura Sieb., Quercus aliena Blume, Robinia pseudoaccacia and Pinus densiflora), weed sources; 5 species(Artemisia princeps Pampanini, Erigeron canadensis, Alopecurus aegualis Sobolewski, Echinochloa crusgalli var. frumentacea(Roxb.) Wight and Rumex crispus), and native grass sources; 5 species(Zoysia japonica Steudel, Agropyron tsukushiense var. transiens(Hack) Ohwi., Arundinella hirta(Thunb.) Tanaka, Miscanthus sinensis Anderss and Phragmites comunis Trin). Five sika deer were selected which had nearly the same body weight(average 92.5kg) as experimental animal. Experimental roughages were prepared by 0.5kg(DM basis) per 1 species fed to sika deer, and the experiment was carried out from 08:00 to the next day 06:00. The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period. The sika deer ate more roughages which had low fibrous contents, but high dry matter digestibility. Among all the 25 species of roughages, the favorite intake species ranking by sika deer was observed like this: Quercus aliena Blume, Prunus jamasakura Sieb, Quercus serrata Thunb. and Trifolium pratense, respectively, and the lower intake species was Phragmites comunis Trin. On the other hand, compared to each roughage source, total intake amount by sika deer was showed as browse(36.5%), Legumes(34.2%), grasses(14.0%), native grasses(13.5%) and weeds(1.8%), respectively. Based on the result, the food habits of sika deer seems to be closer to typically browser type.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.179-183
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• 1980

The efficiency of energy transfer by a population of the farmed pacific oyster, Crassostrea gigas was studied during culture period of 10 months July 1979-April 1980, in Geoje-Hansan Bay near Chungmu City. Energy use by the farmed oyster population was calculated from estimates of half-a-month unit age specific natural mortality rate and data on growth, gonad output, shell organic matter production and respiration. Total mortality during the culture period was estimated approximate $36\%$ from data on survivor individual number per cluster. Growth may be dual consisted of a curved line during the first half culture period (July-November) and a linear line in the later half period (December-April). The first half growth was approximated by the von Bertalanffy growth model; shell height, $SH=6.33\;(1-e^{0.2421(t+0.54)})$, where t is age in half-a-month unit. In the later half growth period shell height was related to t by SH=4.44+0.14t. Dry meat weight (DW) was related to shell height by log $DW=-2.2907+2.589{\cdot}log\;SH,\;(2, and/or log $DW=-5.8153+7.208{\cdot}log\;SH,\;(5. Size specific gonad output (G) as calculated by condition index of before and after the spawning season, was related to shell height by $G=0.0145+(3.95\times10^{-3}{\times}SH^{2.9861})$. Shell organic matter production (SO) was related to shell height by log $SO=-3.1884+2.527{\cdot}1og\;SH$. Size and temperature specific respiration rate (R) as determined in biotron system with controlled temperature, was related to dry meat weight and temperature (T) by log $R=(0.386T-0.5381)+(0.6409-0.0083T){\cdot}log\;DW$. The energy used in metabolism was calculated from size, temperature specific respiration and data on body composition. The calorie contents of oyster meat were estimated by bomb calorimetry based on nitrogen correction. The assimilation efficiency of the oyster estimated directly by a insoluble crude silicate method gave $55.5\%$. From the information presently available by other workers, the assimilation efficiency ranges between $40\%\;and\;70\%$. Twenty seven point four percent of the filtered food material expressed by energy value for oyster population was estimated to have been rejected as pseudofaeces : $17.2\%$ was passed as faeces; $35.04\%$ was respired and lost as heat; $0.38\%$ was bounded up in shell organics; $2.74\%$ was released as gonad output, $2.06\%$ was fell as meat reducing by mortality. The remaining $15.28\%$ was used as meat production. The net efficiency of energy transfer from assimilation to meat production (yield/assimilation) of a farm population of the oyster was estimated to be $28\%$ during culture period July 1979-April 1980. The gross efficiency of energy transfer from ingestion to meat production (yield/food filtered) is probably between $11\%\;and\;20\%$.

• Korean Journal of Cognitive Science
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• v.23 no.1
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• pp.109-132
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• 2012

According to recent embodied cognition approach, understanding of actions is not based on abstract symbolic process but based on mental simulation of sensory-motor information related to those actions. As supporting evidence, motor resonance effect is a facilitation/interference effect of motor response in terms of similarity between observed action and concurrent own action. In the current research, we investigated this effect in the situation to perceive a complex social action perception and how it would be modulated by perspectives of construals of the social action scene. For this purpose, we created three kinds of fighting action scenes of two people in terms of body actions of the subject(ie., hitting, stepping, biting), and described them in two perspectives; active and passive. During the experiment, subjects had to verify the congruency of the picture and the description first, and if they are congruent, they had to do two different actions in terms of color of following cues. In the first experiment, subjects' response time for stepping on a pedal and pressing a button were analyzed for measuring motor resonance effect for the foot movement. In the second experiment, voice response time with a microphone and button pressing time were analyzed for the mouth movement motor resonance effect. Results showed the facilitation of the foot movement(in Exp1), and the mouth movement(in Exp2) only when the action scene was described in active perspective. Our results indicate that the motor resonance effect can be occurred during perception of social actions in the real life situation, but it can be also modulated by the perspective of the mental construal of the action event.

• Journal of Korean Academy of Nursing
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• v.26 no.1
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• pp.223-247
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• 1996

This study was done to provide information which would lead to nursing care of the elderly being more holistically through an understanding of the phenomena of powerlessness based on the lived experience of powerlessness by the elderly, the meaning the elderly give to such phenomena, and what essence of powerlessness is. The methodology used in this study was Max Van Manen's phenomenological method based on the philosophy of Merleu-Ponty and a concerted approach was realized through the 11 steps suggested in the Van Manen's method. Data collection was done from March 2, 1995 to December 30, 1995. The subjects for this study were four elderly persons who lived with their families and who were over 60 years of age. Data were collected about the lived experience of the elderly, this researcher's experience of powerlessness, the linguistic meaning of powerlessness, idioms of the word or a feeling of powerlessness, and descriptions of powerlessness in the elderly as they appeared in the literature, are works, and phenomenological literature. All data were used to provide insights into the phenomena of powerlessness. Data about the experience of powerlessness by the elderly were collected through open interviews, participation, and observation. In the analysis of the theme of this study, the aspects of the theme, powerlessness in the elderly were clarified, thereby abstracting and finding meaningful statements by the elderly about their feeling of powerlessness, and then those significant statements were expressed as linguistic transformations. The summarized findings from the study are as follows : 1. Five meanings of powerlessness in the elderly were defined. 〈weakness〉, 〈dependence〉, 〈frustration〉, 〈worthlessness〉 and 〈giving up〉. 2. 〈Weakness〉 means that the elderly experience, not only their aging but also, their becoming weak and the loss of physical function frequently caused by diseases. 〈Dependence〉 means that the elderly experience dependence without any influence from the surroundings and that elderly patients who are hospitalized lose their autonomy, follow entirely their doctor's prescriptions, use aid equipment and directions, and depend only on those things. 〈Frustration〉 means that the elderly experience the loss of their roles from the past, there by feeling that there is no work for them to do anymore and therefore feel unable to do anything. 〈Worthlessness〉 means that the elderly experience the feeling of losing their social roles from the past, having no financial ability, thereby being a burden to their children or the people around them, and therefore regarding themselves useless. 〈Giving up〉 means that the elderly experience the feeling of closeness to death in the final stage of their lifetime, lose hope to be healed from their disease, and recognize the incontrollability of their own body. 3. From a general view of the meaning of the theme the powerlessness in the elderly-the most essential meaning of the theme is the 〈sense of loss〉. For the elderly are experiencing a sense of loss in the situation of being elderly and therefore being often hospitalized. Brief definitions of the five phenomena could be 〈weakness〉 meaning the loss of physical strength, 〈dependence〉 the loss of mentality caused by disease and hospitalization, 〈frustration〉 and 〈worthlessness〉 the loss of social performance caused by the loss of social functions from the past, and lastly 〈giving up〉 the loss of the controllability of such situations of aging and suffering disease. In light of the discussion above, it is understandable that the hospitalized elderly experience powerlessness not only as it related to their diseases but also to their normal aging, and this related to other characteristics of being elderly means that the 〈sense of loss〉 is the very essence of their powerlessness. 4. While most cases are of the normal elderly experiencing powerlessness in relation to their social network, cases of elderly who are hospitalized are of those experiencing powerlessness in relation to the loss of their physical desire. 5. The findings discussed above can serve as guidelines for nurses who take care of the ill elderly who are hospitalized and that can provide cues to appropriate nursing service, recognizing that the subjective experience of the objective age of the elderly is so important. Nurses can provide highly qualitative nursing service, based on their deep understanding of the suffering of the elderly due to feelings of powerlessness.