• The korean journal of orthodontics
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• v.27 no.3 s.62
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• pp.421-430
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• 1997

Alveolar bone grows with development of tooth germs and roots; bone deposition occurs with tooth eruption. Bone components undergoes processes of resorption and deposition, and when the balance between them is disrupted, decrease in alveolar bone height or excessive bone deposition result. It has been hon that repositioning of teeth through orthodontic treatment can cause alveolar bone resorption which result in decreased alveolar bone height, and there have been many studies to evaluate such effects. X-ray films that could be replicated and standardized were chosen in clinical studies, and among them, bitewing films were used for objective evaluation of changes in alveolar bone level. Twenty subjects, 10 to 13-year- old (average 12.2) children with Cl I molar key, healthy oral condition, no congenital missing, no periodontal disease, and pre-and post-orthodontic bitewing films, were randomly selected for comparison of alveolar bone heights. Amounts of tooth and changes in alveolar bone heights were analyzed. The following results were obtained: 1. Amount of tooth movement in canine, premolar, and molar regions, changes in tooth axis, and changes in alveolar bone heights were measured, and the mean and median values were obtained. 2. When pre-and post-orthodontic alveolar bone levels were compared, larger changes were noticed in maxilla than mandible. 3. When mesio-distally compared, larger changes were observed in the distal sides of 3D3 and 4M3, mesial sides of 4M3 and 4D3, distal sides of 4D3 and 5M3, mesial sides of 5M3 and 5D3, md distal sides of 5D3 and 6M3. 4. When the amounts of tooth movements(TX, TY)and changes in tooth axis(A) were compared,34TX, 34TY, 34A of both sides in maxilla were greater, iud changes in alveolar bone level were greater than any other region.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.3
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• pp.477-500
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• 1999

Korean labor market has showed remarkable change of the increase in the amount of unemployment and contingent employment since IMF bailout agreement. There is a theoretical position to explain this increase in contingent employment at hospitals with the notion of flexibility. The high flexibility of employment due to the increase of contingent employees is becoming very important part in new business strategy of hospitals. The types of contingent employment of the nurse are part-time employment temporary employment, fixed-term employment, and internship which was introduced in early 1999. Recently, Korean health care industry managers have paid attention to the customer oriented service, rationalization of business administration, service quality control so that they can adjust their business to outer environment. Especially their efforts concentrate on the wage reduction through efficient and scientific control of man power because wage shares about 40% of total cost. This dissertation aims at verifying the phenomena of the contingent employment of the nurse and analyzing the related factors and problems. To rephrase these aims in ordinal: First, verifying the phenomena of contingent employment of the nurse. Second, verifying the problems of that phenomena. Third, analyzing the related factors of the contingent employment of the nurse. To accomplish these research goals, a statistical survey was executed. in which 384 questionnaires-66 for manager nurses, 318 for contingent nurses - were given to nurses working at 66 hospitals-which have at least 100 beds-in Seoul. Among them, 187 questionnaires-38 from manager nurses, 149 from contingent nurses'- 'were returned. Then, the data coded and submitted to T-test, $X^2$ -test, variance analysis(ANOVA), correlation analysis, multiple regression analysis, Logistic Regression with SAS program. The research results of the contingent nurses are followings: 1. The average career term at the present hospital 8.4 months: duty-on days per month are 24.2 days: working time per day is 7.9 hours. These results showed little difference from regular nurses. 2. Their wage level is about 70% of regular nurses except for internship nurses whose wage level is 41% of regular nurses. To break down the wage composition, part-time nurses and internship nurses get few allowance and bonus. And contingent nurses get very low level of additional pay except for fixed-term nurses who are under similar condition of employment to regular nurses. These results show that hospital managers are trying to reduce the labor cost not only through the direct way of wage reduction but through differential treatment of bonus, retirement allowance, and other additional pay. 3. The problem of contingent employment: low level of pay; high level of turn-over rate: weakening of union; low level of working condition: heavy burden of work; inhuman treatment. The contingent nurses consider these problems more seriously than manager nurses do. What manager nurses regard problematic is the absence of feeling-belonged and responsibility of the contingent nurses. 4. The factors strongly related with the rate of the number of contingent nurses for the number of regular nurses; gross turn-over nurses; average in-patients per day; staring wage of graduate from professional college: the type of hospital ownership; the number of beds; the gap between gross newcomer nurses and gross turn-over nurses. The factors related with their gross wage per month; the number of beds; applying of health insurance; applying of industrial casualty insurance; applying of yearly-paid leave; the type of hospital ownership; average out-patients per day; gross turn-over nurses. The meaningful factors which make difference by employment type: monthly-paid leave; physiological leave. The logistic regression analysis using these two factors shows that monthly-paid leave is related with the type of hospital ownership; the number of beds; average out-patient per day, and physiological leave is related with the gross newcomer nurses; gross turn-over nurses; the number of beds.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.257-258
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• 2004

The dose from radionuclides released from high-level radioactive waste (HLW) glasses as they corrode must be taken into account when assessing the performance of a disposal system. In the performance assessment (PA) calculations conducted for the proposed Yucca Mountain, Nevada, disposal system, the release of radionuclides is conservatively assumed to occur at the same rate the glass matrix dissolves. A simple model was developed to calculate the glass dissolution rate of HLW glasses in these PA calculations [1]. For the PA calculations that were conducted for Site Recommendation, it was necessary to identify ranges of parameter values that bounded the dissolution rates of the wide range of HLW glass compositions that will be disposed. The values and ranges of the model parameters for the pH and temperature dependencies were extracted from the results of SPFT, static leach tests, and Soxhlet tests available in the literature. Static leach tests were conducted with a range of glass compositions to measure values for the glass composition parameter. The glass dissolution rate depends on temperature, pH, and the compositions of the glass and solution, The dissolution rate is calculated using Eq. 1: $rate{\;}={\;}k_{o}10^{(ph){\eta})}{\cdot}e^{(-Ea/RT)}{\cdot}(1-Q/K){\;}+{\;}k_{long}$ where $k_{0},\;{\eta}$ and Eaare the parameters for glass composition, pH, $\eta$ and temperature dependence, respectively, and R is the gas constant. The term (1-Q/K) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_{0},\;{\eta}\;and\;E_{a}$ are the parameters for glass composition, pH, and temperature dependence, respectively, and R is the gas constant. The term (1-Q/C) is the affinity term, where Q is the ion activity product of the solution and K is the pseudo-equilibrium constant for the glass. Values of the parameters $k_0$, and Ea are determined under test conditions where the value of Q is maintained near zero, so that the value of the affinity term remains near 1. The dissolution rate under conditions in which the value of the affinity term is near 1 is referred to as the forward rate. This is the highest dissolution rate that can occur at a particular pH and temperature. The value of the parameter K is determined from experiments in which the value of the ion activity product approaches the value of K. This results in a decrease in the value of the affinity term and the dissolution rate. The highly dilute solutions required to measure the forward rate and extract values for $k_0$, $\eta$, and Ea can be maintained by conducting dynamic tests in which the test solution is removed from the reaction cell and replaced with fresh solution. In the single-pass flow-through (PFT) test method, this is done by continuously pumping the test solution through the reaction cell. Alternatively, static tests can be conducted with sufficient solution volume that the solution concentrations of dissolved glass components do not increase significantly during the test. Both the SPFT and static tests can ve conducted for a wide range of pH values and temperatures. Both static and SPFt tests have short-comings. the SPFT test requires analysis of several solutions (typically 6-10) at each of several flow rates to determine the glass dissolution rate at each pH and temperature. As will be shown, the rate measured in an SPFt test depends on the solution flow rate. The solutions in static tests will eventually become concentrated enough to affect the dissolution rate. In both the SPFt and static test methods. a compromise is required between the need to minimize the effects of dissolved components on the dissolution rate and the need to attain solution concentrations that are high enough to analyze. In the paper, we compare the results of static leach tests and SPFT tests conducted with simple 5-component glass to confirm the equivalence of SPFT tests and static tests conducted with pH buffer solutions. Tests were conducted over the range pH values that are most relevant for waste glass disssolution in a disposal system. The glass and temperature used in the tests were selected to allow direct comparison with SPFT tests conducted previously. The ability to measure parameter values with more than one test method and an understanding of how the rate measured in each test is affected by various test parameters provides added confidence to the measured values. The dissolution rate of a simple 5-component glass was measured at pH values of 6.2, 8.3, and 9.6 and $70^{\circ}C$ using static tests and single-pass flow-through (SPFT) tests. Similar rates were measured with the two methods. However, the measured rates are about 10X higher than the rates measured previously for a glass having the same composition using an SPFT test method. Differences are attributed to effects of the solution flow rate on the glass dissolution reate and how the specific surface area of crushed glass is estimated. This comparison indicates the need to standardize the SPFT test procedure.

• Journal of Life Science
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• v.15 no.5 s.72
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• pp.790-795
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• 2005

The effects of liquid culture of Coriolus (C) versicolor on weight gain, food intakes, food efficiency ratios, serum and hepatic lipid concentrations were investigated in male rats fed the high cholesterol diets. Eight weeks old Sprague-Dawley rats were given three different types of diet for six weeks, respectively: a control diet ($ 20\% fat +0.5 \% $ cholesterol), two kinds of C versicolor diet (control diet + $ 30\% or 40\%$C. versicozor in water) according to the levels of C. versicolor supplementation. The body weight gains of the rats fed $ 30\% or 40\% $ C. versicolor diets were lower than those in the rats fed the control diet. The food intake, food efficiency ratios, and liver, kidney, epididymal fat pad weights of the rats fed $ 30\% or 40\%$ C. versicoEer diets were similar to those of the rats fed the control diet. The concentrations of hepatic cholesterol and triglyceride in the rats fed $ 30\% or 40\% $ C. versicolor diets were significantly lower than those in the rats fed the control diet. The concentrations in serum total cholesterol, LDL-cholesterol, and atherogenic index ratios were significantly lower in the rats fed $ 30\% or 40\%$ C. versicolor diets compared to those fed the control diet. The HDL-cholesterol/total-cholesterol ratios was significantly higher in the rats fed $ 30\% or 40\% $ C. versicolor diets compared to those fed the control diet. The fecal excretion of total lipid and triglyceride in the rats fed $ 40\% $ C. versicolor diet was significantly higher than that of the rats fed the control diet. There were no significant difference found in the serum trigly-ceride, phospholipid and HDL-cholesterol concentrations among the experimental groups. These results showed that the C. versicolor feeding decreased the hepatic cholesterol, triglyceride, and the serum total cholesterol, LDL-cholesterol and atherogenic index, and increased the serum HDL-cholesterol/ total-cholesterol ratio of the rats.

• Journal of Korean Academy of Nursing
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• v.25 no.1
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• pp.61-79
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• 1995

When children are admitted to hospital, they have to adapt to new and unfamiliar stimuli. Children may respond with fear to stimuli such as pain or unfamiliar experiences. One goal of nursing is to help hospitalized children to adapt effectively to their hospital experience. Accordingly, nurses need to assess childrens' fears of their hospital experience to contribute to the planning of care to alleviate these fears. The problem addressed by this study was to identify and measure hospital-related fears(hereafter called HRF) in hospitalized school-aged children. The study was conceptualized with Roy's model. A descriptive qualitative approach was used first, followed by a quantitative approach. This study was conducted from November 30, 1989 to January 12, 1991. The sample consisted of 395 hospitalized school-aged children selected through an allocated sampling technique in nine general hospitals. The HRF questionnaire (three point likert scale ) was developed by a delphi technique. The data were analyzed by an SAS program. Factor analysis was used for the examination of component factors. Differences in the HRF related to demographic variables were examined by t-test, analysis of variance and the Scheffe test. The crude scores of the HRF scale were transformed into T- scores to calculate the standard scores. The results included the following : 1. Forty-four items were derived from 188 statements identifying the childrens' hospital-re-lated fears. These items clustered into 14 factors, fear of injections, operations, bodily harm others' pain, medical rounds, physical examinations, medical staff, disease process, blood and X-rays, drugs and cockroaches, tests, harsh discipline from parents or staff, being absent from school, and separation from family. The 14 factors was classified into four categories,'pain','the unfamiliar','the un-known' and 'separation'. 2. The reliability of the HRF instruments was .92(Cronbach's alpha). In the factor analysis, Cronbach's alpha coefficients for the 14 factors ranged from .84 to .86 and Cronbach's alpha coefficients for the four categories ranged from .70 to .84. Pearson correlation coefficient scores for relationships among the 14 factors ranged from ,11 to .50, and among the four categories, from ,44 to ,63, indicating their relative independence. 3. The total group HRF score ranged from 45 to 130 in a possible range of H to 132, with a mean of 74.51. The fears identified by the children were, in order, injections, harsh discipline by parents or staff, bodily harm, operations, medical staff, disease process, and medical rounds ; the least feared was others' pain. The fear item with the highest mean score was surgery and the lowest was examination by a doctor. HRF scores were higher for girls than for boys, and for grade 1 students than for grade 6 students. HRF scores were lower for children whose fathers were over 40 than for those whose fathers were in the 30 to 39 age group, and whose mothers were over 35 than for those whose mothers were in the 20 to 34 age group. HRF scores were lower when the mother rather than any other person stayed with the child. The expressed fear of pain, the unfamiliar, the un-known and of separation directs nurses' concern to the threat felt by hospitalized children to their concept of self. This study contributes to the assessment of fears of hospitalized children and of stimuli impinging on those fears. Accordingly, nursing practice will be directed to the alleviation of pain, pre-admission orientation to the hospital setting and routines, initiation of information about procedures and experiences and arrangments for mothers to stay with their children. Recommendations were made for further research in different settings and for development and testing of the instrument.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.366-374
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• 2010

Introduction: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. Materials and Methods: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+$10\;{\mu}g$), (2) Silk fibroin (SF: $10\;{\mu}g$), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. Results: The SF-BMP group ($48.86{\pm}14.92%$) had a significantly higher mean percentage bone area than the SF group ($24.96{\pm}11.01%$) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group ($40.01{\pm}12.43%$) had a higher % bone area at postoperative 8 weeks than the SF group ($33.26{\pm}5.15%$). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group ($0.67{\pm}0.08$) had a higher mean ratio level than the SF group ($0.61{\pm}0.09$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) The ratio of the calcium and phosphate contents of the SF-BMP ($0.93{\pm}0.22$) group was lower than that of the SF ($1.90{\pm}1.42$) group at postoperative 4 weeks. However, the SF-BMP group ($0.75{\pm}0.31$) had a higher Ca/$PO_4$ ratio than the SF ($0.68{\pm}0.04$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.126 and P=0.627, respectively) For the bone-specific alkaline phosphatase (ALP) activity, which is recognized as a reliable indicator of the osteoblast function, the SF-BMP ($23.71{\pm}8.60\;U/L$) groups had a significantly higher value than the SF group ($12.65{\pm}6.47\;U/L$) at postoperative 4 weeks.(P<0.05) At postoperative 8 weeks, the SF-BMP ($21.65{\pm}10.02\;U/L$) group had a lower bone-specific ALP activity than the SF group ($16.72{\pm}7.35\;U/L$). This difference was not statistically significant.(P=0.263) For the histological evaluation, the SF-BMP group revealed less inflammation, lower foreign body reactions and higher bone healing than the SF group at postoperative 4 and 8 weeks. The SF group revealed more foreign body reactions at postoperative 4 weeks. However, this immunogenic reaction decreased and the remnant of grafted material was observed at postoperative 8 weeks. For histomorphometric analysis, the SF-BMP group had a significantly longer bone length to total length ratio than those of the SF group at postoperative 4 and 8 weeks.(P<0.05) Conclusion: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered bone regeneration.

• Child Health Nursing Research
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• v.20 no.3
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• pp.159-167
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• 2014

Purpose: The purpose of this study was to investigate factors associated with sexual debut among Korean middle school students. Methods: From the database of the Eighth Korea Youth Risk Behavior Web-based Survey (KYRBS), the researchers selected 37,297 middle school students aged 12-15 years. Data were analyzed using $x^2$ test and multiple logistic regression with the SPSS WIN 18.0 program. Results: The proportion of middle school students who had a sexual debut was 2.1% of boys and 1.5% of girls. In multiple regression analysis, economic status, experience of part time work, smoking, drug use and depression were associated with an increased proportion of sexual intercourse for both boys and girls. Living with parents, drinking alcohol and suicidal ideation were associated with sexual debut for boys only. By contrast, formal sexual education was associated with a reduced risk of sexual debut. Conclusion: The results of this study show the factors associated with sexual debut among Korean middle school students. Gender-related interventions should be taken into consideration in school sexual education programmes, because of differences in related factors according to gender.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.6
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• pp.819-826
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• 2009

An in vitro study was conducted to investigate the effect of malate or fumarate on fermentation characteristics, and production of conjugated linoleic acid (CLA) and methane ($CH_4$) by rumen microbes when incubated with linolenic acid (${\alpha}-C_{18:3}$). Sixty milligrams of ${\alpha}-C_{18:3}$ alone (LNA), or ${\alpha}-C_{18:3}$ with 24 mM malic acid (M-LNA) or ${\alpha}-C_{18:3}$ with 24 mM fumaric acid (F-LNA) were added to the 150 ml culture solution consisting of 75 ml strained rumen fluid and 75ml McDougall's artificial saliva. Culture solution for incubation was also made without malate, fumarate and ${\alpha}-C_{18:3}$ (Control). Two grams of feed consisting of 70% concentrate and 30% ground alfalfa (DM basis) were also added to the culture solution of each treatment. In vitro incubation was made anaerobically in a shaking incubator up to 12 h at $39^{\circ}C$. Supplementation of malate (M-LNA) or fumarate (F-LNA) increased pH at 6 h (p<0.01) and 12 h (p<0.001) incubation times compared to control and linolenic acid (LNA) treatments. Both malate and fumarate did not influence the ammonia-N concentration. Concentration of total VFA in culture solution was higher for M-LNA and F-LNA supplementation than for control and LNA treatments from 6 h (p<0.040) to 12 h (p<0.027) incubation times, but was not different between malate and fumarate for all incubation times. Molar proportion of $C_3$ was increased by F-LNA and M-LNA supplementation from 6 h (p<0.0001) to 12 h (p<0.004) incubation times compared to control and LNA treatments. No differences in $C_{3}$ proportion, however, were observed between M-LNA and F-LNA treatments. Accumulated total gas production for 12h incubation was increased (p<0.0002) by M-LNA or F-LNA compared to control or LNA treatment. Accumulated $CH_4$ production for 12 h incubation, however, was greatly reduced (p<0.0002) by supplementing malate or fumarate compared to the control, and its production from M-LNA or F-LNA treatment was smaller than that from LNA treatment. Methane production from LNA, M-LNA or F-LNA treatment was steadily lower (p<0.01 - p<0.001) from 3 h incubation time than that from the control, and was also lower for M-LNA or F-LNA treatment at incubation times of 6 h (p<0.01) and 9 h (p<0.001) than for LNA treatment. Methane production from LNA, however, was reduced (p<0.01 - p<0.001) from 3 h to 9 h incubation times compared to the control. Both malate and fumarate increased concentration of trans11-$C_{18:1}$ from 3 h to 12 h incubation (p<0.01), cis9,trans11-CLA up to 6 h incubation (p<0.01 - p<0.01), trans10,cis12-CLA at 3 h (p<0.05) and 12 h (p<0.01), and total CLA for all incubation times (p<0.05) compared to corresponding values for the ${\alpha}-C_{18:3}$ supplemented treatment (LNA). In conclusion, malate and fumarate rechanneled the metabolic $H_2 pathway to production of propionate and CLA, and depressed the process of biohydrogenation and methane generation. Linolenic acid alone would also be one of the optimistic alternatives to suppress the $CH_4$ generation.

• Investigative Magnetic Resonance Imaging
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• v.5 no.1
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• pp.57-65
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• 2001

Purpose : $T_2$-weighted half courier Echo Planar Imaging (T2HEPI) method is proposed to reduce measurement time of existing EPI by a factor of 2. In addition, high $T_2$ contrast is obtained for clinical applications. High resolution single-shot EPI images with $T_2$ contrast are obtained with $128{\times}128$ matrix size by the proposed method. Materials and methods : In order to reduce measurement time in EPI, half courier space is measured, and rest of half courier data is obtained by conjugate symmetric filling. Thus high resolution single shot EPI image with $128{\times}128$ matrix size is obtained with 64 echoes. By the arrangement of phase encoding gradients, high $T_2$ weighted images are obtained. The acquired data in k-space are shifted if there exists residual gradient field due to eddy current along phase encoding gradient, which results in a serious problem in the reconstructed image. The residual field is estimated by the correlation coefficient between the echo signal for dc and the corresponding reference data acquired during the pre-scan. Once the residual gradient field is properly estimated, it can be removed by the adjustment of initial phase encoding gradient field between $70^{\circ}$ and $180^{\circ}$ rf pulses. Results : The suggested T2EPl is implemented in a 1.0 Tela whole body MRI system. Experiments are done with the effective echo times of 72ms and 96ms with single shot acquisitions. High resolution($128{\times}128$) volunteer head images with high $T_2$ contrast are obtained in a single scan by the proposed method. Conclusion : Using the half courier technique, higher resolution EPI images are obtained with matrix size of $128{\times}128$ in a single scan. Furthermore $T_2$ contrast is controlled by the effective echo time. Since the suggested method can be implemented by software alone (pulse sequence and corresponding tuning and reconstruction algorithms) without addition of special hardware, it can be widely used in existing MRI systems.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.10-14
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• 1999

A single phase composter was constructed by modifying the conventional mixer of sawdust for the cultivation of oyster mushroom Pleurotus ostreatus. The machine was designed on the basis of 3-phase-1 system which was controlled in prewetting, pasteurization and fermentation processes. In composting 200 kg of straw and cotton waste in the machine, it took 20 minutes in prewetting step and also to hours at $65^{\circ}C$ in pasteurization process. Postfermentation by aerothermophiles was completed by treating the compost at $45^{\circ}C-50^{\circ}C$ for 48 hours which was shorten 24 hours from the conventional method. In the postfermentation at high temperature, forced aeration and/or vigorous mixing process(es) played a great role in the improvement of spawn quality. The growth of mycelium of oyster mushroom was excellent in the culture combinated with 3 parts of surface inoculation and 7 parts of mechanical mixing.