• The Korean Journal of Food And Nutrition
• /
• v.15 no.4
• /
• pp.370-376
• /
• 2002

This study was designed to investigate lunch of the boy's and girl's middle school students in Busan. The survey was conducted from September 15 to September 30 in 2002. It was revealed that there is no difference in the scores measuring the knowledge In nutrition and the eating habit between male students and females. 10.6 % of the male students scored poor in the knowledge in nutrition, 38.2% fair 42.5% good and 8.7% excellent respectively while 4.1% of the female students scored poor in the same area, 31.6% fair, 52.1% good and 12.2% excellent respectively. The biggest number of both group of students scored good in their eating habit, the second biggest fair, the third biggest excellent and the least scored poor. Female students were reported to bring their lunch more than the male students do(p<0.05). And there was a significantly difference in the frequency of bringing lunch according to their knowledge in nutrition and their dietary attitude(p<0.001), but whether mothers have .jobs or not, mothers'educational background or monthly expenses for food didn't seem to make any differences. The intakes of nutritional elements except phosphorus and vitamin C are lower than RDA. The ratio of intakes of nutritional elements from lunch was 13∼14.1% of calcium, 17.9∼19.2% of vitamin A and 19.3∼19.6% of iron, showing a significant unbalance in nutritional intakes. Nutritional intakes had little relationship with the knowledge in nutrition and eating habit. The frequency of carrying lunch, energy intakes and phosphorus intakes had significantly relationship with each other. And the better the eating habit was, the more often the individual carried lunch.

• Journal of Nutrition and Health
• /
• v.51 no.2
• /
• pp.121-131
• /
• 2018

Purpose: This study was aimed to assess selenium and zinc status in female collegiate athletes and their relationship with dietary intake. Methods: Female collegiate athletic groups of judo and aerobics, and healthy sedentary collegiate females were recruited for this study and their serum selenium and zinc contents were measured by the neutron activation analysis (NAA) method. In addition, the dietary intake of subjects was measured using the two days 24-hour recall method. Results: Serum selenium in judo athletes was $10.7{\mu}g/dl$, which was significantly lower than that of aerobic athletes ($12.2{\mu}g/dl$), but not different from that of the sedentary group ($11.4{\mu}g/dl$). Additionally, serum zinc levels were $96.1{\mu}g/dl$ and $90.2{\mu}g/dl$ in aerobic and judo athletes, respectively, which did not differ significantly. Moreover, dietary selenium and zinc intake of the athletic groups did not differ significantly from that of the sedentary female group. Overall, 33.3% of the serum selenium concentration variation was explained by the intake of vitamin E, selenium and saturated fatty acids, while 14.7% of the serum zinc level variation was explained by the intake of saturated fatty acids. The strongest dietary indicator for serum selenium and zinc levels was saturated fatty acids intake. Conclusion: Judo athletes appear to have lower selenium status than aerobic athletes, suggesting different body selenium status according to sport type. To maintain body selenium and zinc levels, the dietary intake of saturated fatty acids should be decreased.

• Journal of Bio-Environment Control
• /
• v.12 no.1
• /
• pp.45-53
• /
• 2003

The object of this study was to develop the control technology of daily integral photosynthetic photon flux (PPF) by the artificial lighting and shading screen in greenhouse. The shading time needed to get the target PPF by using two types of shading screens having shading ratio of 55% and 85% was analyzed. The results showed the shading ratio of screen to be installed in greenhouse should be different depending on the amount of target PPF to be controlled. The PPF control experiment by using the 55% shading screen in July and August showed that the maximum difference between measured and calculated value was about 5 mol$.$ $m^{-2}$ $.$ $d^{-1}$ in no shading condition. This difference is satisfactory result because the daily integral PPF is quite different depending on the weather condition. The simulation result about PPF distribution pattern shortened the time needed to find the proper arrangement of artificial lightings in greenhouse. But the further study was required to find the supplemental lighting arrangement to be able to provide the exactly uniform distribution of target light intensity. The supplemental irradiation time needed to acquire the target daily integral PPF for different supplemental light intensities, weather conditions, and months was analyzed. The result showed that the supplemental light intensity should be decided depending on the amount of target PPF to be controlled. The result of PPF control experiment conducted by using 55% shading screen and 300 $\mu$mol$.$ $m^{-2}$ $.$ $s^{-1}$ supplemental light intensity from the end of May to the beginning of June showed that the maximum difference between target and measured value was about 3 mol$.$ $d^{-1}$ $.$ $m^{-2}$ . If we consider that the difference of the daily integral PPF depending on weather condition was the maximum 30 mol$.$ $m^{-2}$ $.$ $d^{-l}$, the control effect was acceptable. Although the result of this study was the PPF control technology to grow lettuce, the data and control method obtained could be employed for other crop production.n.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.1 no.1
• /
• pp.1-11
• /
• 1999

Rice yield and primary productivity (NPP) are dependent upon the variability of climate and soil. The variability and regionality of the rice yield and net primary productivity were evaluated with the meteorological data collected from Korea Meteorology Administration and the actual rice yield data from the Ministration of Agriculture and Forestry, Korea. The estimated NPP using the three models, dependent upon temperature(NPP-T), precipitation(NPP-P) and net radiation(NPP-R), ranged from 10.87 to 17.52 Mg ha$^{-1}$ with average of 14.69 Mg ha$^{-1}$ in the South Korea and was ranged 6.47 to 15.58 Mg ha$^{-1}$ with average of 12.59 Mg ha$^{-1}$ in the North Korea. The primary limiting factor of NPP in Korea was net radiation, and the secondary limiting factor was temperature. Spectral analysis on the long term change in air temperature in July and August showed periodicity. The short periodicity was 3 to 7 years and the long periodicity was 15 to 43 years. The coefficient of variances, CV, of the rice yield from 1989 to 1998 ranged 3.23 percents to 12.37 percents which were lower than past decades. The CV's in Kangwon and Kyeongbuk were high while that in Chonbuk was the lowest. The prediction model based on th e yield index and yield response to temperature obtain ed from the field crop situation showed reasonable results and thus the spatial distributions of rice yield and predicted yield could be expressed in the maps. The predicted yields was well fitted with the actual yield except Kyungbuk. For better prediction, modification should be made considering radiation factor in further development.

• Journal of the Korean Institute of Gas
• /
• v.24 no.2
• /
• pp.1-8
• /
• 2020

Centrifugal pump is a facility that transfers energy to fluid through centrifugal force, which is usually generated by rotating the impeller at high speed, and is a major process facility used in many LNG production bases such as vaporization seawater pump, industrial water and fire extinguishing pump using seawater. to be. Currently, pumps in LNG plant sites are subject to operating conditions that vary depending on the amount of supply desired by the customer for a long period of time. Pumps in particular occupy a large part of the consumption strategy at the plant site, and if the optimum operation condition is not available, it can incur enormous energy loss in long term plant operation. In order to solve this problem, it is necessary to identify the performance deterioration factor through the flow analysis and the result analysis according to the fluctuations of the pump's operating conditions and to determine the optimal operation efficiency. In order to evaluate operation efficiency through experimental techniques, considerable time and cost are incurred, such as on-site operating conditions and manufacturing of experimental equipment. If the performance of the pump is not suitable for the site, and the performance of the pump needs to be reduced, a method of changing the rotation speed or using a special liquid containing high viscosity or solids is used. Especially, in order to prevent disruptions in the operation of LNG production bases, a technology is required to satisfy the required performance conditions by processing the existing impeller of the pump within a short time. Therefore, in this study, the rotation difference of the pump was applied to the ANSYS CFX program by applying the modified 3D modeling shape. In addition, the results obtained from the flow analysis and the curve fitting toolbox of the MATLAB program were analyzed numerically to verify the outer diameter correction theory.

• Journal of the Korean Society of Radiology
• /
• v.16 no.2
• /
• pp.95-102
• /
• 2022

This study compares the difference between the remaining amount in syringes according to injection method and the dose of physiological saline when the radiopharmaceutical ¹⁸F-FDG isotope is injected into patients who visited the hospital for PET examination. After performing a CT or MRI using a contrast medium when ¹⁸F-FDG was injected into 40 patients who came to the hospital for PET examination without removing the 3-way, the radioactivity remaining in the syringe and the 3-way was measured and the dose of radioactivity confirmed. At this time, 20 patients were divided into different dose groups of physiological saline. Another injection method was used to compare the remaining amount of the syringe and the difference in the remaining amount according to the amount of physiological saline when the injection was performed with an extension. After an injection of ¹⁸F-FDG, the actual administered dose was confirmed by measuring the radioactivity remaining in the syringe and the 3-way or extension with a calibrator. As a result of measuring the radioactivity of the syringe before administering the radiopharmaceutical and the radioactivity of the syringe and the 3-way or extension after administration, the 3-way injection method in 10 cc's of physiological saline had the lowest residual amount. The remaining amount increased in the order of the extension to 10 cc's of saline and the 3-way to 5 cc's of saline. Likewise, the 5 cc's saline solution and the extension injection method demonstrated the highest residual amounts. The residual difference with the lowest level of remaining injection method was found to be 0.053 mCi. It was found that in a PET examination, by considering the radioactivity remaining in the 3-way and extension and by adjusting the dose of physiological saline, if the intended dose to be administered to the actual patient is determined, it is possible to administer the radiopharmaceutical to the patient more accurately.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.16 no.1
• /
• pp.70-75
• /
• 2012

Purpose: It is important to acquire accurate data because the SPECT scan affected by various physical factors. The aim of this study was to compare the uniformity when both centers were matched or mismatched differed from position of heart in COR. Materials and methods: The images were acquired with cylindrical uniform phantom (6.7 cm diameter, 9 cm length) and heart insert phantom using Cardio MD SPECT system (Philips, USA). The phantoms were positioned on COR as well as four different points which were 10 cm above, below, left and right side from the COR. The counts from the both edge of cylindrical uniform phantom and those from the both wall of heart insert phantom were compared by using vertical and horizontal line profile. In addition, the qualitative evaluation was performed with heart insert phantom images and volunteer test. Results: In heart insert phantom study, the differences of counts between COR and 10 cm above, below, left and right point of COR were 1.1, 4.1, 4.9, 2.2 and 0.9% using T-A curve for horizontal view. In case of vertical view of COR 3.9, 21.9, 3.5, 23.9, 14.0% were shown. In cylindrical phantom study, the differences of counts between COR and 10 cm above, below, left and right point of COR were 4.3, 0.3, 3.3, 2.6 and 0.7% using T-A curve for horizontal view. In case of vertical view of COR 2.7, 3.0, 1.0, 0.3, 3.4% were shown. For qualitative evaluation, the images at COR were the most uniform for both of heart insert phantom and volunteer test, whereas other four positions showed somewhat distorted images. Conclusion: It showed the most uniform images when COR is matched with the heart. Therefore, we can expect that distortion which increased or decreased of myocardial perfusion will be prevented by matching the heart and COR when positioning. Furthermore, the accuracy of diagnosis will be improved as well.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.8 no.2
• /
• pp.202-212
• /
• 2005

Purpose: Transfusion transmitted virus (TTV) is a newly discovered virus and to date the contribution of TTV to liver disease remains unclear. Little is known about the frequency of TTV infection in children in Korea. The purpose of this study was to investigate the prevalence and genotypic distribution of TTV carried by healthy children and patients with hepatitis in Korea. Methods: Eighty eight of healthy children and three groups of patients with hepatitis-14 patients with chronic hepatitis B, 12 patients with chronic hepatitis C and 25 patients with hepatitis of unknown etiology-were tested. TTV DNA was detected by semi-nested PCR using primer sets generated from N-22 region and from 5' noncoding region (NCR) of the viral genome. PCR products derived from 8 patients with hepatitis and from 11 healthy children were sequenced and a phylogenetic tree was constructed. Results: TTV was found by PCR with N22 primer in 11.3% of healthy children, 28.5% of children with hepatitis B, 25% of children with hepatitis C, 24% of children with hepatitis of unknown etiology. TTV DNA was found by PCR with 5'NCR primer in 32.9% of healthy children, 71.4% of patients with chronic hepatitis B, in 50% of patients with hepatitis C and in 48% of patients with hepatitis of unknown etiology. TLMV DNA was found in 48.9% of healthy children, 21.4% of patients with hepatitis B, 16.6% of patients with hepatitis C, 40% of patients with hepatitis of unknown etiology. Among the sequenced isolates, 10(52%) belonged to genotype 1 (G1) and others belonged to genotype 2 (G2) or genotype 3 (G3). Among the G1 sequences, 7 were grouped as G1a. Conclusion: TTV infection was common in healthy children and in patients with hepatitis. But, the prevalence of TTV DNA by 5'NCR primer was relatively high in patients with hepatitis B and there may be some association between TTV and hepatitis B virus infection. G1 was the major genotype of the studied population.

• Food Science and Preservation
• /
• v.14 no.4
• /
• pp.414-418
• /
• 2007

The physicochemical characteristics and sensory properties of Deodeok wine, formed by leaching of Deodeok at room temperature for 180 days, were investigated over the following range of Deodeok levels: 10, 15 and 20% (all w/v). The higher the level of Deodeok, the greater were the final values of total sugars, reducing sugars, total polyphenols, and crude saponins. The Hunter's b-value (yellowness) of Deodeok wine varied markedly with Deodeok levels, and yellowness was highest in Deodeok wine containing 20% (w/v) Deodeok. Non-volatile compounds, that form the basis of the liquor tax law, were 0.64, 1.38 and 2.11% (all w/v), respectively, at day 160. Of these values, that of 2.11% (w/v), the level of non-volatile compounds in Deodeok wine containing 20% (w/v) Deodeok, was in accord with the liquor tax law (that requires this figure to be 2.0%). Sensory evaluation showed that Deodeok wine containing 20% (w/v) Deodeok was superior to the other wines tested.

• Journal of Korea Water Resources Association
• /
• v.52 no.10
• /
• pp.743-752
• /
• 2019

The flow in the meandering channel is characterized by the spiral motion of secondary currents that typically cause the erosion along the outer bank. Hydraulic structures, such as spur dike and groyne, are commonly installed on the channel bottom near the outer bank to mitigate the strength of secondary currents. This study is to investigate the effects of submerged vanes installed in a $90^{\circ}$ meandering channel on the development of secondary currents through three-dimensional numerical modeling using the hybrid RANS/LES method for turbulence and the volume of fluid method, based on OpenFOAM open source toolbox, for capturing the free surface at the Froude number of 0.43. We employ the second-order-accurate finite volume methods in the space and time for the numerical modeling and compare numerical results with experimental measurements for evaluating the numerical predictions. Numerical results show that the present simulations well reproduce the experimental measurements, in terms of the time-averaged streamwise velocity and secondary velocity vector fields in the bend with submerged vanes. The computed flow fields reveal that the streamwise velocity near the bed along the outer bank at the end section of bend dramatically decrease by one third of mean velocity after the installation of vanes, which support that submerged vanes mitigate the strength of primary secondary flow and are helpful for the channel stability along the outer bank. The flow between the top of vanes and the free surface accelerates and the maximum velocity of free surface flow near the flow impingement along the outer bank increases about 20% due to the installation of submerged vanes. Numerical solutions show the formations of the horseshoe vortices at the front of vanes and the lee wakes behind the vanes, which are responsible for strong local scour around vanes. Additional study on the shapes and arrangement of vanes is required for mitigate the local scour.