• Journal of The Korean Association For Science Education
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• v.31 no.6
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• pp.827-835
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• 2011

This study investigated the effect of introducing advanced science contents into the science curriculum 10th grade on students' interest in science. Four classes of the 10th grade were selected from a co-ed high school located in the city of Seoul. Among them, each two classes were assigned as a control group and treatment group, respectively. Students in each group were divided into three groups according to their previous science achievement. The treatment group was taught with materials consisting of advanced science content that was associated with the 'Reaction Rates', 'Environment' and 'Inquiry of Science' section of the curriculum. Before and after being taught over a six-week period, students' interest in science and science class were measured. The data showed that there was a significant correlation between the instruction and students' previous science achievement in the 'interest in science'(p<.01). There was a significant difference between the two groups in the 'interest in science class' irrespective of their prior science achievement (p<.05). The data showed that the introduction of advanced science content into the science curriculum had considerable effect on increasing students' interest in science and science class. Moreover, many students expected more opportunities to learn advanced science content associated with the science curriculum.

• The korean journal of orthodontics
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• v.30 no.4 s.81
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• pp.467-473
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• 2000

As a rectangular wire Is inserted into edgewise brackets the wire exerts a force system three-dimensionally. The force system may include bending force in first and second orders and a torsional force in third order Analytical and experimental studies on bending force have been Introduced, but information about torsion is still lack. The purpose of this study was to estimate the torsional moment in the force system of rectangular arch wires through theoretical and experimental studies. Wires most frequently used for third order control were selected as study materials. Cross sections of 0.016x0.022, 0.017x0.025, 0.019x0.025 inch rectangular wires in foot different materials such as stainless steel(Ormco), TMA(Ormco), NiTi(Ormco), and braided stainless steel (DentaFlex, Dentaurum) were used. The torque/twist rate of each test material was calculated using the torsion formula. Torque/twist rate, yield torsional moment, and ultimate torsional moment were measured with a torque gauge. The torsion formula assesses that the torque/twist rate (T/$\theta$) is proportional to the characteristics of material (G) and cross section (J), and is inversely proportional to the length of wire (L). Most experimental results corresponded with the formula. The relative stiffness was calculated for reference to a logical sequence of wire changes.

• Journal of Convergence for Information Technology
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• v.10 no.3
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• pp.195-199
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• 2020

This study examined the effect of the nervous-system-stimulating caffeine on the nerve conduction velocity. The purpose of this study is to investigate the effect of caffeine that stimulates the nervous system on nerve conduction test. Although both measurement intervals did not show statistically significant differences when comparing the pre- and post-NCV values within the control and individual experimental groups, it was found that the nerve conductivity in the Axilla-Above Elbow section increased significantly after caffeine intake for the experimental group. Caffeine intake, which has increased the nerve conduction velocity (NCV), was determined to play roles in improving motor skills, muscle strength and nerve performance by temporarily increasing the nerve conduction velocity. Through this study, we learned that caffeine has an influence on the peripheral nervous system as it helps to improve the nerve conduction velocity. upon an appropriate amount of caffeine intake. We hope that these results will help develop treatment and diagnostic methods for patients with nerve dysfunction and myofunctional disorders.

• Journal of Society of Preventive Korean Medicine
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• v.18 no.1
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• pp.11-21
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• 2014

Objective : This study set out to combine the treatment efficacy of Taraxacum with Dongchimi fermentation and investigate Taraxacum's effects on protection of liver cell and controlling nitric oxide(NO) through experiments, thus checking whether it had values as a physiological active matter. The experimental materials include Taraxacum Dongchimi (TD) and Taraxacum fermented by Dongchimi (TDF). As for methodology, experiments were carried out to compare TD and TDF in components, protection effects for liver cells, anticancer effects on liver cells, and protection effects for brain cells in the aspects of liver function and immunity enhancement. Method : The experimental materials include Taraxacum Dongchimi (TD) and Taraxacum fermented by Dongchimi (TDF). As for methodology, experiments were carried out to compare TD and TDF in components, protection effects for liver cells, anti-cancer effects on liver cells, and protection effects for brain cells in the aspects of liver function and immunity enhancement. Results : As shown in the chromatogram results, each valid component content increased in Taraxacum fermented by Dongchimi (TDF) for each time section. Of them, the valid component content at 36.80 minutes was approximately 2.7 times higher in TDF at 21.8% than in Taraxacum Dongchimi (TD) at 8.28%. TDF generated more excellent protection effects against the toxicity that caused oxidative damage to the liver cell(HepG2) with t-BHP than TD. The survival rate was low in TD of $100{\mu}g/m{\ell}$ and $300{\mu}g/m{\ell}$ and increased to 23.3% in TDF of $100{\mu}g/m{\ell}$. The survival rate was the highest at $300{\mu}M$ with a significant difference of 68.1%(P<0.05). Both TD and TDF showed effects of controlling nitric oxide production according to concentration with TDF recording a higher rate of controlling nitric oxide production than TD. There were significant differences(P<0.05) in the effects of controlling nitric oxide production at 200 ug/ml, 400 ug/ml in both groups. Especially the result TDF of $400{\mu}g/m{\ell}$ was thus similar to those of butein, the positive control group. Conclusion : The result of this studies is that Taraxacum fermented by Dongchimi (TDF) increased the valid component content compared with the simple mixture(TD). The findings clearly show that it is a material with the effects of improving immunity and liver cell protection. If fermentation methods are further developed to use it as a functional material, it will be subject to more opportunities of being used in other functional foods and make a contribution to integrated medicinal food development.

• Journal of the Society of Disaster Information
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• v.13 no.3
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• pp.366-375
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• 2017

Internal factors having effects on compressive strength test results of concrete include size, shape, height-diameter ratio(h/d), section processing method, dryness and wetness, etc. of the specimen. As it is difficult to ensure dimensions of core specimen due to rebar cutting from rebar spacing, wall thickness, effects on the structure, etc. when taking core of the concrete structure, correction of dimensions and h/d of the specimen become important for quality control of the concrete. Thus, in order to review effects of specimen size and height-diameter ratio for the concretes with compressive strength within 40~60MPa, this study has experimentally reviewed compressive strength test values by applying correction factors pursuant to KS F 2422 (Method of obtaining and testing drilled cores and sawed beams of concrete), when changing specimen diameter to ${\emptyset}5{\sim}15cm$, and h/d to 2.0~1.25.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2689-2696
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• 2015

Radioactive isotopes which are manufactured using a cyclotron in a radioisotope used for radiation diagnosis is affected by the production yield according to size and shape of the beam and beam uniform degree from irradiated location when the proton beam investigated the target by cyclotron. Therefore, in this paper developed the BPM(Beam Profile Monitor) device capable of measuring the beam cross-section at the cyclotron beam line. It was configured so as to be able to remote control the BPM device in LabView and used the BPM program it was to be able to easily monitor and display to analyze the graph of two-dimensional graph and a three-dimensional beam distribution numerical information of the beam obtained while scanning the tungsten wire to the X and Y axis. The time it takes to measure the beam can be confirmed 37seconds when step motor driving speed was 2000pps. Through a beam readjusted based on the measured beam distribution information by optimizing the beam distribution it can be made to maximize the RI production yield and contribute supply stabilization.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.102-109
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• 1992

There was significant reduction in the mitotic indices of oat roots treated with alachlor. Uniform decrease in prophase, metaphase, anaphase, and telophase as treatment time increasing was observed. Alachlor did not disrupt mitosis, but rather inhibited the onset of mitosis. Labeled dividing cells were significantly inhibited, but the number of labeled interphase cells of all treatment were increased, as compared with control in 8 hr and 12hr period. Labeled dividing cells which entered mitosis thru $G_2$ were inhibited approximately 68% at 8hr after treatment with $1{\times}10^{-5}$ M of alachlor. Alachlor apparently inhibited from the $G_2$stage into mitosis of dividing cells. After 24 hr treatment, 12.1% abd 46.6% inhibition of coleoptile growth occurred at $1{\times}10^{-5}$ M and $1{\times}10^{-4}$ M, respectively. Cell elongation was inhibited by alachlor but was less sensitive than cell division. The longitudinal section cells of oat roots treated with $1{\times}10^{-4}$ M alachlor for 12 hr were observed to be enlarged central cylinder and also showed degradation of apical meristem zone, as compared with the untreated roots.

• Journal of The Korean Society of Clinical Toxicology
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• v.16 no.2
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• pp.141-148
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• 2018

Purpose: The Korean government approved selected nonprescription drugs (Over-The-Counter drug; OTC drug) to be distributed in convenience stores from 15. Nov. 2012. This study examined the changes in the incidence and the clinical outcome of acute pharmaceutical drug poisoning after the deregulation of OTC drug sales. Methods: This study analyzed the data of Emergency Department based Injury In-depth Injury Surveillance (EDIIS), Korea Centers for Disease Control and Prevention, from 2011 to 2014. The following items were examined: age, gender, intention, alcohol association, pharmaceutical drugs resulting acute poisoning, the clinical outcomes in emergency department, and the admission rate of intensive care unit (ICU). This is a retrospective cross section observational study. Results: A total of 10,162 patients were subject to pharmaceutical drug poisoning. Acute poisoning by acetaminophen and other drugs were 1,015 (10.0%) and 9,147 (90.0%) patients, respectively. After the deregulation of OTC drug sales, acute poisoning by other drugs increased from 4,385 to 4,762 patients but acute poisoning by acetaminophen decreased from 538 to 477 patients (p<0.05). The rate of admission of acetaminophen poisoning increased from 36.1% (194/538) to 46.8% (223/477). The admission rate to the ICU by acetaminophen poisoning increased from 4.6% (25/538) to 11.3% (54/477) after the deregulation of OTC drug sales (p<0.05). Conclusion: Since the deregulation of OTC drugs sales, pharmaceutical drug poisoning has increased but acetaminophen poisoning has decreased. The rate of hospitalization and ICU admission by pharmaceutical drug poisoning with or without acetaminophen has also increased.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.655-660
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• 2020

High amylose corn starch and dextrin (acid-treated at 30, 40 and 50℃ denominated as Dextrin30, Dextrin40 and Dextrin50) were added to non-fried instant noodles. X-ray diffraction pattern, water absorption, cooking loss, microstructure, and textural properties of non-fried instant noodles were investigated. The addition of high amylose corn starch/dextrin induced a slight peak intensity at 20o in the X-ray pattern indicating the insignificant formation of amylose-lipid complex. Non-fried instant noodles including high amylose corn starch/dextrin showed lower water absorption than the control. Dense microstructure in transverse section of noodles was observed in non-fried instant noodles including high amylose corn starch/dextrin except Dextrin50. Also, the addition of high amylose corn starch/dextrin induced low tensile strength, high firmness, and high stickiness. However, non-fried instant noodles containing Dextrin50 showed a loose microstructure and high cooking loss (3.98%), which might be associated with the textural properties such as the lowest tensile strength (0.17 N), lowest increase in firmness (46.77 N) and highest stickiness (18.43 N).

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_2
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• pp.1011-1017
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• 2023

In this study, the harmless crack size (a_hml) by double shot peening (DSP) using shot balls with different diameters was evaluated on carburized, quenched-tempered SCM822H steel. The minimum crack size (a_NDI) detectable by non-destructive inspection was also evaluated. The relationship between the crack size (a_25,50) that reduces the fatigue limit by 25% and 50% and a_hml was evaluated. The residual stress of DSP was greater in SP_(0.6+0.08) than SP_(0.8+0.08) and appeared deeper in the depth direction. In addition, the hardness below the surface appeared larger. The fatigue limit of DSP increased 2.07 times and 1.95 times compared to non-SP. All a_hml of the DSP specimen was determined at the depth (a). The compressive residual stress distribution affects a_hml, and the a_hml of SP_(0.6+0.08), which has a large compressive residual stress and a high fatigue limit, appeared large. a_hml of SP_(0.6+0.08) introduced deeper than the residual stress of SP_(0.8+0.08) is larger in the range of As=1.0-0.3. Since the residual stress in the thickness direction has a greater effect on a_hml than the residual stress at the surface, it is necessary to introduce it more deeply. The relation of a_hml, a_25,50, and a_NDI were evaluated in the point for safety and reliability.