• Journal of radiological science and technology
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• v.38 no.2
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• pp.107-114
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• 2015

The purpose is reducing radiation dose while maintaining of image quality in liver dynamic CT(LDCT) scan, by protocols generally used and the tube voltage set at a low level protocol compared to the radiation dose and image quality. The target is body mass index, 18.5~24 patients out of 40 patients who underwent the ACT(abdominal CT). Group A(tube voltage : 120kVp, SAFIRE strength 1) of 20 people among 40 people, to apply the general abdominal CT scan protocol, group B(tube voltage : 100kVp, apply SAFIRE strength 0~5) was 20 people, set a lower tube voltage. Image quality evaluation was setting a region of interest(ROI) in the liver parenchyma, aorta, superior mesenteric artery (SMA), celiac trunk, visceral fat of arterial phase. In the ROI were compared by measuring the noise, signal to noise ratio(SNR), contrast to noise ratio(CNR), CT number. In addition, qualitative assessments to evaluate two people in the rich professional experience in Radiology by 0-3 points. We compared the total radiation dose, dose length product(DLP) and effective dose, volume computed tomography dose index(CTDIvol). The higher SAFIRE in the tube voltage 100 kVp, noise is reduced, CT number was increased. Thus, SNR and CNR was increased higher the SAFIRE step. Compared with the tube voltage 120kVp, noise, SNR, CNR was most similar in SAFIRE strength 2 and 3. Qualitative assessment SAFIRE strength 2 is the most common SAFIRE strength 2 the most common qualitative assessment, if the tube voltage of 100kVp when the quality of the images better evaluated was SAFIRE strength 1. Dose was reduced from 21.69%, in 100kVp than 120kVp. In the case of a relatively high BMI is not LDCT scan, When it is shipped from the factory tube voltage is set higher, unnecessary radiation exposure when considering the reality that is concerned, when according to the results of this study, set a lower tube voltage and adjust the SAFIRE strength to 1 or 2, the radiation without compromising image quality amount also is thought to be able to be reduced.

• Journal of the Korean Society of School Health
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• v.14 no.1
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• pp.131-143
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• 2001

The primary aim of this dissertation is to contribute to the improvement of methods in physical examination by providing quality information for the current school system and advice for improving status. Present status, controversial points and possible remedies in physical examination were analyzed on a frequency and percentage basis. An $x^2$-test was used to verify the statistics between the results from the examination and each variable. In case of multiple categories of variables, an $x^2$ cs was adopted. Chronological data as well as both total and sampling physical examination data verified the statistics using an $x^2$-test. This thesis is based both on the data from middle school health care specialists in Gyunggi Province and on the analysis of physical examinations reported from local schools to the municipal education agency from 1997 to 1999. The results of the study are as follows: First, according to the survey, only 29.0% of the total schools had their school doctors examine all the students while most of the educational institutions failed to implement the whole process of physical examination on the list. It also turned out that the more students the schools have, the lower the rate of implementation of physical examination by school doctors(p=0.014). Second, the average time a school doctor spends for checkup turned out to be approximately 1.7 minutes per student This means that the quality of the physical examination is not guaranteed in the process. Third, 47.7% of those surveryed say that a dental examination was performed, each taking 21.24 seconds on average. In addition, it shows that some 31.5% wanted to have a task force team for dental checkups at the local health center. Given the fact that dental caries among students is progressively on the rise, the dental health centers that are now set up in some elementary schools should be expanded to cover the whole educational institution in order to raise awareness of the importance of dental care. Fourth, 48.5% of those surveyed say that a comprehensive physical examination should be adopted to promote the health of high schoolers. Since it takes a lot of public funds to implement a comprehensive method, it is essential to make sure that in-depth studies should be based on the frequency and methods of physical examination. Fifth, regarding such diseases among 3rd year middle school students in 1999, statistics shows that there was a slight difference in the prevalence rate of color blindness, and allergic diseases for male students ; and color blindness, hearing disturbance and allergic disease for female students. For those items, however, it is too little to say that there is a significant difference and accordingly it is assumed to be a problem of the measuring process. Sixth, the result of analysis on the sample physical examination and the total physical examination of the year 1999 shows as follows: For male students in the 3rd year of middle school, a slight difference appeared to those students in 11 items including eye problems and eye disease, otitis media, tonsillar hypertrophy, spinal shape, respiratory urinary allergic disease and other abnormal diseases(p<0.05). Particularly, the prevalence rate between students with and without disease was shown to be two times more in the following: eye problems, otitis media, tonsill hypertrophy, allergic diseases, etc. For female students in the 3rd year, prevalence rate showed little difference in 14 items(p<0.05). For items including eye problem, otitis media, tonsill hypertrophy, allergic disease, etc. it was shown that the rate was two times more between students with and without diseases. Physical examinations under the current school system are not producing any fundamental results for the health of the students. Methods and results are not trustworthy. Accordingly, a drastic overhaul of the current practices is needed in frequency, methods and items on the list in order to promote the health of the students. Cost-benefit studies as well as political considerations to ensure the development of efficient methods for physical examination are urgently needed at this moment.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.1
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• pp.16-27
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• 2018

To predict the influence of volcano eruption on agriculture in South Korea we evaluated the dispersal ranges of the volcanic ashes toward the South Korea based on the possibilities of volcano eruption in Mt. Baekdu. The possibilities of volcano eruption in Mt. Baekdu have been still being intensified by the signals including magmatic unrest of the volcano and the frequency of volcanic earthquakes swarm, the horizontal displacement and vertical uplift around the Mt. Baekdu, the temperature rises of hot springs, high ratios of $N_2/O_2$ and $_3He/_4He$ in volcanic gases. The dispersal direction and ranges and the predicted amount of volcanic ash can be significantly influenced by Volcanic Explosivity Index (VEI) and the trend of seasonal wind. The prediction of volcanic ash dispersion by the model showed that the ash cloud extended to Ulleung Island and Japan within 9 hours and 24 hours by the northwestern monsoon wind in winter while the ash cloud extended to northern side by the south-east monsoon wind during June and September. However, the ash cloud may extent to Seoul and southwest coast within 9 hours and 15 hours by northern wind in winter, leading to severe ash deposits over the whole area of South Korea, although the thickness of the ash deposits generally decreases exponentially with increasing distance from a volcano. In case of VEI 7, the ash deposits of Daejeon and Gangneung are $1.31{\times}10^4g\;m^{-2}$ and $1.80{\times}10^5g\;m^{-2}$, respectively. In addition, ash particles may compact close together after they fall to the ground, resulting in increase of the bulk density that can alter the soil physical and chemical properties detrimental to agricultural practices and crop growth.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.791-806
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• 2020

In this study, a block shear strength test was conducted to compare and analyze the strength and failure mode on the glued laminated timber, CLT, and Ply-lam CLT, which are mainly used for the construction of wood construction as engineering wood. Through this, the Ply-lam CLT manufacturing conditions for optimum production, such as the type of lamina, plywood, adhesive, and layer composition, were investigated. The results are as follow. Through block shear strength test, it showed high strength in the order of glued laminated timber, Ply-lam CLT and CLT. In particular, the shear strength of Ply-lam CLT, which is made of a composite structure of larch plywood and larch lamina, passed 7.1 N/㎟, which is a Korean industrial standards for block shear strength of structural glued laminated timber. In addition, in this study, there was no different in shear strength according to the adhesive type used for glulam, CLT, and Ply-lam CLT adhesion. However, in the case of Ply-lam CLT, the difference in shear strength of Ply-lam CLT was shown according to the type of lamina and plywood. The results showed high strength in the order of Larix kaempferi > Mixed light hardwood ≒ Pinus densiflora, sieb, et, Zucc plywood. The optimal configuration of Ply-lam CLT is when larch plywood and larch lamina are used, and it is decided that the adhesive can be used by selecting PRF and PUR according to the application. The results of block shear strength failure mode by type of wood based materials were analyzed. The failure mode showed shear parallel-to-grain for glulam, rolling shear for CLT, and shear parallel-to-grain and rolling for ply-lam CLT. This is closely related to shear strength results and is decided to indicate higher shear strength in Ply-lam CLT than in CLT due to rolling shear.

• Journal of the Mineralogical Society of Korea
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• v.16 no.3
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• pp.201-213
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• 2003

The adsorption property and ability of domestic zeolites for some heavy metal ions (Ag, Pb, Cr, Cu, Zn, Mn), which may cause a serious environmental problem in industrial wastewater, were evaluated on ore unit through a series of adsorption experiments together with careful examinations of mineral composition and properties of the zeolites. Though the adsorption behavior basically took place in the form of a cation exchange reaction, the higher CEC value does not necessarily to imply the higher adsorption capacity for a specific heavy metal. A general trend of the adsorption selectivity for heavy metals in the zeolites is determined to be as follow: $Ag\geq$Pb>Cr,Cu$\geq$Zn>Mn, but the adsorption properties of heavy metal ions somewhat depend on the species and composition of zeolite. Clinoptilolite tends to adsorb selectively Cu in case of Cr and Cu, whereas heulandite prefers Cr to Cu. A dominant adsorption selectivity of the zeolite ores for Ag and Pb is generally conspicuous regardless of their zeolite species and composition. The zeolite ores exhibit a preferential adsorption especially for $Ag^{+}$ so as not to regenerate when treated with $Na^{+}$ . In the adsorption capacity for heavy meta ions, the zeolites differ in great depending on their species: ferrierite>clinoptilolite>heulandite. Considering the CEC value of mordenite, the mordenite-rich ore appears to be similar to the clinoptilolite ore in the adsorption capacity. The adsorption capacity for heavy metals is not positively proportional to the CEC values of the zeolites measured by the exchange reaction with ammonium ion. In addition, the adsorption capacity roughly tends to depend on the zeolite contents, i.e., the grade of zeolite ore, but the trend is not consistent at all in some ores. These may be caused by the adsorption selectivity for some specific heavy metals, the presence of possible stacking micro-faults and natural cations such as K hardly to exchange in the zeolite. Considering the economic availability and functional effectiveness as natural zeolite resources, clinoptilolite ores could be applicable to utilize the domestic zeolites for the removal of heavy metals.

• The Korean Journal of Nuclear Medicine
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• v.5 no.1
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• pp.49-64
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• 1971

The radioactive $^{131}I$-rose bengal serial scintiphotography was performed in 62 patients with the hepatobiliary diseases and in 20 normal subjects. This approach permitted visualization of the hepatic uptake of $^{131}I$-rose bengal from the circulation and its excretion into the biliary trees and the intestines. In some of these patients, gallbladder function was examined, using eggs as a gallbladder constrictor. The time of maximum hepatic uptake was well correlated to the conventional biochemical liver function tests. In addition to $^{131}I$-rose bengal scintiphotography, $^{198}Au$-colloid scintiphotography was also performed to make comparison of these two tests. The results obtained were as follows: 1. In normal subjects, the maximum hepatic uptake of $^{131}I$-rose bengal occurred at $23{\pm}2.9$ minutes, the initial hepatic excretion at $34{\pm}5.1$ minutes, the visualization of the gallbladder at $29{\pm}5.7$ minutes and the intestinal visualization at $54{\pm}25.8$ minutes. The radioactivity in the gallbladder decreased to $10.7{\pm}5.0%$ one hour after the ingestion of eggs. 2. In the patients with cirrhosis of the liver, there was a delayed and decreased hepatic uptake. The maximun hepatic upake occurred at $43{\pm}12.9$ minutes. The differences in the results of uptake between the cirrhotic and the normal group were statistically significant. The initial hepatic excretion occurred at $60{\pm}18.5$ minutes and had tendency of delaying compared with the normal controls. The gallbladder was visualized in 13 of 16 cases (81%) and its visualization occurred at $49{\pm}14.6$ minutes with a tendency to be delayed compared with the normal controls. The intestinal visualization occurred at $63{\pm}15.8$ minutes and its delaying tendency was somewhat more prominent. 3. In patients with hepatitis, the maximum hepatic uptake occurred at $59{\pm}21.4$ minutes and was significantly delayed. The initial hepatic excretion occurred at $82{\pm}34.3$ minutes and the results revealed a delaying tendency. The gallbladder was visualized in 15 of 20 cases (75%) at $57{\pm}18.7$ minutes, which was significantly delayed. The Intestinal visualization was noted in all cases with marked delay. 4. In patients with obstructive jaundice, the maximum hepatic uptake was noted at $83{\pm}14.7$ minutes, showing the most significant delay. The hepatic excretion into biliary trees and intestines was not entirely noted in all cases except the only one case with gallbladder visualization. 5. In patients with cholelithiasis, the maximum hepatic upake and the initial hepatic excretion were slightly delayed with mean times of $39{\pm}11.2\;and\;48{\pm}17.1$ minutes respectively. The visualization of the gallbladder was demonstrated in 10 of 17 cases (59%) and occurred at $52{\pm}25.6$ minutes with a slight delay. The intestinal visualization occurred at $67{\pm}47.7$ minutes and was slightly delayed. $^{131}I$-rose bengal in the gallbladder remained high, $49.3{\pm}21.3%$, which suggested quantitatively decreased power of gallbladder constriction. 6. The time of the maximum hepetic uptake was correlated well to BSP retention and serum alkaline phosphatase ativity. However, the maximum hepatic uptake had no definite correlation with serum albumin, serum globulin, TTT, serum cholesterol, SGPT or SGOT. 7. In the diagnosis of the hepatobiliary diseases with jaundice, $^{131}I$-rose bengel serial scintiphotography has proved to be more useful than $^{198}Au$-colloid scintiphotography. With these results, it could be justified that $^{131}I$-rose bengal scintiphotography is an excellent diagnostic aid for dynamic hepatobiliary function studies in the clinical practice.

• Journal of fish pathology
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• v.14 no.1
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• pp.46-53
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• 2001

The present study was undertaken to investigate and compare the effect and mode of action of tachykinins on isolated strip preparations of the intestinal smooth muscle from the nile tilapia, Oreochromis niloticus and the Israel carp, Cyprinus carpio. Both of neurokinin 1(NK-1) receptor agonist, substance P(SP) and neurokinin 2(NK-2) receptor agonist, neurokinin A(NKA) caused concentration-dependent contractions of intestinal smooth muscle in the nile tilapia and the israel carp. The efficiency and potency of these agonists varied between two fish species. In the nile tilapia intestine, the efficiency and potency of SP were greater than those of NKA. However, the efficiency and potency of SP were similar to those of NKA. In the nile tilapia intestine and the israel carp intestine, the contractile responses of SP and NKA were noncompetitively antagonized by NK-1 receptor antagonist, L-732, 138 but unaffected by NK-2 receptor antagonist, MDL 29913. In addition, SP-induced contractions in the both of preparation were significantly inhibited by muscarinic antagonist, atropine($5{\times}10^{-7}$M) and ganglionic inhibitor, tetrodotoxin($2{\times}10^{-7}$M) but NKA-induced contractions were unaffected by those. These results indicate that two tachykinin agonists, SP and NKA predominately modulate the mechanical activity of isolated preparation from the nile tilapia and the israle carp directly through the activation of NK-1 receptor on the intestinal smooth muscle cells, but in the case of SP action, the indirect action through activation of cholinergic nerve terminals seems to be also implicated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.568-574
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• 1996

The purpose of this study was to investigate the effect of dietary Fe and Se levels on lipid contents of serum and liver in growing rats fed adequate Fe(35ppm), medium-high Fe(70ppm), high Fe(140ppm), adequate Se(0.05ppm), and high Se(0.Sppm) for 6 weeks. Serum levels of Fe and Se increased as the levels of dietary Fe and Se were increased, respectively(P<0.05, p<0.05), Serum levels of total cholesterol and (LDL＋VLDL)-cholesterol increased as the level of dietary Fe was increased (p<0.001, p<0.001), and were lower in high-Se group than those in adequate-Se group(p<0.001, P<0.001). Liver Fe level in High-Se group was lower than that in adequate-Se group(p<0.01) and liver Se level decreased as the dietary Fe level was increased(p<0.05). Liver levels of phospholipid and total lipid in high-Se group were lower than that in adequate-Se group(p<0.05 p<0.01). Liver levels of triglyceride and total lipid decreased as the level of dietary Fe was increased(p<0.05 p<0.01). From these results, it is considered that serum lipid contents are increased in case of Fe overload and decreased with adding Se. Therefore, it could be suggested that adequate Fe intake and Se addition are recommended for prevention of lipid increment in serum.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.239-244
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• 2008

To evaluate the acidity and chemical characteristics of rainwater in Korea, its pH and ion concentrations were investigated in Suwon from April to December, 2006. In addition, to estimate the contribution of ions on its acidity, ion composition and neutralization effect of major cations were investigated. Ion balance and electrical conductivity balance between measured and estimated values showed a high correlation. The mean pH and EC in rainwater collected during the investigation periods were 4.7 and $17.6{\mu}S\;cm^{-1}$, respectively. The monthly variation in EC showed a clear seasonal pattern, which had the lowest value of $9.1{\mu}S\;cm^{-1}$ in July and increased remarkably in November. $Na^+$ was the most abundant cation and followed by $NH_4{^+}>Ca^{2+}>H^+>Mg^{2+}>K^+$. Among them, $Na^+$ and $NH_4{^+}$ accounted for more than 65% of the total cations. In case of anions, the relative abundance was $SO_4{^{2-}}>NO_3{^-}>Cl^-$. About 67% of the total anions in rainwater was $SO_4{^{2-}}$, which showed $119.0{\mu}eq\;L^{-1}$ as mean value during the monitoring periods. Furthermore, 94% of the soluble sulfate in rainwater was identified as nss-$SO_4{^{2-}}$(non-sea salt sulfate). We also found that $NH_4{^+}$ and $Ca^{2+}$ contributed greatly in neutralizing the rain acidity, especially in dry season.

• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.441-448
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• 2014

From several researches, recently, it was found that using hollowed precast concrete (HPC) column made more compact concrete casting in joint region possible than using normal solid PC (Precast concrete) column. Therefore, the rigidity of joints can be improved like those of monolithic reinforced concrete (RC). After filling the hollow with grout concrete, however, it is expected that the HPC column behaviors like composite structure since PC element and grout concrete have different materials as well as there is a contact surface between two elements. These may affect the structural behavior and strength of the composite column. A compressive strength test was performed for the HPC column with parameter of hollow ratio for the case with and without grout in the hollow and the result is presented in this paper. The hollow ratios in the test are 35, 50 and 59% of whole section of column. Concentrated axial force was applied to top of the specimens supported as pin connection for both ends. In addition, finite element (FE) analysis was performed to simulate the failure behavior of HPC column for axial compression. As a result, it was found that the hollow ratio did not affect the initial stiffness of HPC filled with grout regardless of the strength difference of HPC and grout. However the strength was increased inversely corresponding to the hollow ratio. The structural capacity of HPC without grout closely related to the hollow size. Especially, the local collapse governs the overall failure when the thickness of HPC is too thin. Based on these effect, a suitable equation was suggested for calculation of the compressive strength of HPC column with or without grout. FE analysis considering the contact surface between HPC and grout produced a good result matched to the test result.