• The Journal of Korean Society for School & Community Health Education
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• v.4
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• pp.43-59
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• 2003

The purpose of this study was to examine whether the gender, grade and school type of middle school students made any differences to their sexual awareness and sexual behaviors in an effort to lay the groundwork for providing more efficient sex education. The research questions were posed as follows: First, what is the sexual awareness of middle school students? Second, what are the sexual behaviors of middle school students? Third, are their gender, school year and school type related to their sexual awareness and behaviors? The subjects in this study were 976 middle school students from Gyeonggi province. After a survey was conducted with questionnaires prepared by this researcher based on earlier studies to suit the purpose of the study, the collected data were analyzed with SPSS 10.0 program. The frequency analysis, x2 test and correlational analysis were implemented, and basic statistical data were obtained. The conclusions were as follows: First, regarding their sexual awareness, the largest group of them agreed that one must report in case of being raped(4.36), and the smallest number of them thought that one might have a sexual relationship with a person other than his or her spouse after marriage(1.56). Second, as for experience of indecent materials, part of sexual behaviors, 67.4 percent had ever contacted such materials. The most common medium through which they contacted them was the Internet(56.5%). The above-mentioned findings suggested that the sexual awareness of the middle school students wasn't influenced by gender or school type. But that varied with grade, as the third graders had the best sexual consciousness. Their sexual behaviors were different according to gender. The boy students contacted more indecent materials, and their experience of such materials varied with grade, since the third graders contacted the most obscene materials. And that also varied with school type, and the non-engineering students contacted more obscene materials. As for sexual drives, their masturbation experience was different according to gender, grade and school type. The number of the boys who practiced masturbation was four-fold larger than that of the girls, and the second graders had more such experience. By school type, the non-engineering students practiced more masturbation, but there was no significant gap between their kissing, caressing and dating experiences.

• Journal of Korean Medicine Rehabilitation
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• v.31 no.4
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• pp.117-127
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• 2021

Objectives Previously, we demonstrated that a 5% ethanol extract of unripe Rubus coreanus (5-uRCK) and ellagic acid has hypocholesterolemic and antiobesity activity in high-fat diet-fed animals. Therefore, we conducted a clinical study on the anti-obesity effect of 5-uRCK in 140 Korean adults (aged 19-70 years, body mass index (BMI) ≥25 kg/m²). Methods The participants were randomly assigned to two groups and were administered the placebo (n=70) or 5-uRCK extract (800 mg, n=70) daily for 12 weeks. The subjects were instructed to maintain their usual dietary intake and normal physical activity. Anthropometrics, body composition (dual-energy X-ray absorptiometry), and blood parameters were compared between the two groups. Results Average body weight and BMI did not show any significant changes; however, changes in upper body fat mass between the two groups was significantly different, as determined using analysis of covariance adjusted for baseline of percent body fat and drinking units. Moreover, Although not significant, the trunk fat mass and percent trunk fat tended to decrease after 5-uRCK supplementation. There was no significant difference in other laboratory biomarkers between the two groups. All safety parameters were within normal ranges in the both group. Conclusions In the present study, 5-uRCK significantly reduced upper body fat in obese subjects after 12 weeks, which indicates that it may help improve android-type obesity. Furthermore, the supplement is safe and well tolerated.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.9
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• pp.1430-1438
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• 2019

Objective: This experiment was designed to determine the effects of coated cysteamine hydrochloride (CC) on muscle fiber characteristics, amino acid composition and transporters gene expression in the longissimus dorsi muscle (LDM) of finishing pigs. Methods: Two hundred and sixteen Duroc/Landrace/Yorkshire cross-bred male finishing pigs were fed with a corn-soybean basal diet supplemented with 0, 70, and 140 mg/kg cysteamine. Each group contained eight replicates of nine pigs per replicate. After 29 days, one pig was randomly selected from each replicate and slaughtered. Blood and LDM samples were collected and analyzed. Results: The results showed that supplemental dietary CC increased (p<0.05) the muscle fiber density. And CC supplementation also up-regulated (p<0.05) the expression of myosin heavy chain 1 (MyHC1) and MyHC2x mRNA levels, and down-regulated (p<0.05) MyHC2b expression in the LDM. Additionally, supplemental dietary CC reduced (p<0.05) the concentration of total cholesterol in the plasma and enhanced (p<0.05) the concentrations of essential amino acid and total amino acid in the LDM. The relative expression levels of chloramphenicol acetyltransferase 2, $b^{0,+}$ amino acid transporter, and $y^+$-L-type amino acid transporter 1 were upregulated (p<0.05) in the LDM when pigs were fed with the dietary CC of 70 mg/kg. Conclusion: Cysteamine supplementation could increase fiber density and distribution of fiber types. It also improved the deposition of protein in the LDM by up-regulated the expression of amino acid transporters.

• Bulletin of the Korean Chemical Society
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• v.15 no.3
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• pp.236-241
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• 1994

The crystal structures of $Cd_6-A$ evacuated at $2{\times}10^{-6}$ Torr and 750$^{\circ}$C (a=12.216(l) ${\AA}$), and of the product of its reaction with Rb vapor (a= 12.187(l) ${\AA}$), have been determined by single-crystal x-ray diffraction techniques in the cubic space group Pm$\bar{3}$m at 21(l)$^{\circ}$C. Their structures were refined to the final error indices, $R_1$=0.055 and $R_2$=0.067 with 191 reflections, and $R_1$=0.066 and $R_2$=0.049 with 90 reflections, respectively, for which I>3${\sigma}$(I). In dehydrated $Cd_6-A$, six $Cd^{2+}$ ions are found at two different threefold-axis sites near six-oxygen ring centers. Four $Cd^{2+}$ ions are recessed 0.50 ${\AA}$ into the sodalite cavity from the (111) plane at O(3), and the other two extend 0.28 ${\AA}$ into the large cavity from this plane. Treatment at 250 $^{\circ}$C with 0.1 Torr of Rb vapor reduces all $Cd^{2+}$ ions to give $Rb_{13.5^-}$A. Rb species are found at three crystallographic sites: three $Rb^+$ ions lie at eight-oxygen-ring centers, filling that position, and ca. 10.5 $Rb^+$ ions lie on threefold axes, 8.0 in the large cavity and 2.5 in the sodalite cavity. In this structure, ca. 1.5 Rb species more than the 12 $Rb^+$ ions needed to balance the anionic charge of zeolite framework are found, indicating that sorption of $Rb^0$ has occurred. The occupancies observed can be most simply explained by two "unit cell" compositions, $Rb_{12^-}A{\cdot}Rb$ and $Rb_{12^-}A{\cdot}2Rb$, of approximately equal population. In sodalite cavities, $Rb_{12^-}A{\cdot}Rb$ would have a $(Rb_2)^+$ cluster and $Rb_{12^-}A{\cdot}2Rb$ would have a triangular $(Rb_3)^+$ cluster. Each of the atoms of these clusters must bind further through a six-oxygen ring to a large cavity $Rb^+$ to give $(Rb_4)^{3+}$ (linear) and $(Rb_6)^{4+}$ (trigonal). Other unit-cell compositions and other cationic cluster compositions such as $(Rb_8)^{n+}$ may exist.

• Bulletin of the Korean Chemical Society
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• v.10 no.3
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• pp.243-247
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• 1989

Two crystal structures of dehydrated $Ag^+\;and\;Ca^{2+}$ exchanged zeolite A, $Ag_2Ca_$5-A, reacting with 0.01 Torr of Cs vapor at $200^{\circ}C$ for 2 hours and 0.1 Torr of Cs vapor at $250^{\circ}C$ for 48 hours, respectively, have been determined by single crystal X-ray diffraction techniques. Their structures were solved and refined in the cubic space group Pm3m at $21(1)^{\circ}C$. The stoichiometry of first crystal was $Ag_2Ca_5$-A (a = 12.294(1)${\AA}$), indicating that Cs vapor did not react with cations in zeolite A and that of second crystal was $Ag_2Cs_{10}$-A (a = 12.166(1)${\AA}$), indicating that all $Ca^{2+}$ ions were reduced by Cs vapor and replaced by $Cs^+$ ions. Full-matrix least-squares refinements of $Ag_2Ca_5-A\;and\;Ag_2Cs_{10}$-A has converged to the final error indices, $R_1\;=\;0.041\;and\;R_2$ = 0.048 with 227 reflections, and $R_1\;=\;0.117\;an\;n\;fdd\;R_2$ = 0.120 with 167 reflections, respectively, for which I > $3{\sigma}$(I). In the structure of $Ag_2Ca_5$-A, both $Ag^+$ ions and $Ca^{2+}$ ions lie on two crystal symmetrically independent threefold axis sites on the 6-rings; $2\;Ag^+$ ions are recessed 0.33 ${\;AA}$ from the (111) planes of three O(3) oxygens and 5 $Ca^{2+}$ ions lie on the nearly center of each 6-oxygen planes. In the structure of $Ag_2Cs_{10}-A,\;Cs^+$ ions lie on the 5 different crystallographic sites. 3 $Cs^+$ ions lie at the centers of the 8-rings at sites of D4h symmetry. 6 $Cs^+$ ions lie on the threefold axes of unit cell: $4\;Cs^+$ ions are found deep in the large cavity and 2 $Cs^+$ ions are found in the sodalite cavity. One $Cs^+$ ion is found in the large cavity near a 4-ring.

• Applied Chemistry for Engineering
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• v.32 no.1
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• pp.55-60
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• 2021

Fluorination was carried out to improve the adsorption performance of pitch-based activated carbon fibers (ACFs) onto acetic acid. Both plasma and direct gas fluorination were used for fluorination, and the acetic acid gas adsorption performance of fluorinated ACFs was investigated. X-ray photoelectron spectroscopy (XPS) is analyzed to determine the surface characteristics of ACFs, and the pore characteristics were analyzed by 77 K nitrogen adsorption. An adsorption performance was measured through gas chromatography, and it was confirmed that the breakthrough time of plasma fluorinated sample was 790 min and that the breakthrough time was delayed compared to that of using untreated one of 650 min. However, the breakthrough time of direct gas fluorinated sample was 390 min, indicating that the adsorption performance was inhibited. The plasma fluorinated ACFs showed an increase in the adsorption performance due to an electrostatic attraction between the acetic acid gas (CH3COOH) with the fluorine group introduced to the surface without changing its specific surface area. On the other hand, the specific surface area of the direct gas fluorinated ACFs decreased significantly up to 55%, and the physical adsorption effect on the acetic acid gas also reduced.

• Resources Recycling
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• v.30 no.4
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• pp.11-19
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• 2021

Arsenic (As) oxidation followed by precipitation from a high-As(III)-containing leaching solution derived from a sulfidic ore was investigated in this study to remove aqueous As from the solution using activated carbon (AC) with air injection as an oxidant. To obtain the initial leaching solution, a domestic sulfidic ore was leached in a sulfuric acid solution at pH 1 and 50℃ for 95 h, and approximately 7 g/L of Fe and 3 g/L of As were leached out. To determine the effect of the oxidative reaction utilizing AC with air injection, the leaching solution was tested under the following five oxidative conditions at an initial pH of 1 and 90℃ for 72 h: air-only injection; air injection with 1, 5, and 10 w/v% of AC addition; and H₂O₂ addition. The tests in the presence of both air and AC revealed that the oxidation kinetics and As removal were improved by the reaction between the metallic species and the surface group formed on the AC surface. In addition, the greater the amount of AC added, the better was the reaction efficiency, removing 93-94% of As with more than 5 w/v% of AC addition. Finally, X-ray diffraction analysis confirmed that the precipitate formed from the oxidative reaction was scorodite (FeAsO₄·2H₂O).

• Journal of Adhesion and Interface
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• v.23 no.2
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• pp.53-58
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• 2022

Here, the surface characteristics of the dielectric were controlled by introducing the self-assembled monolayers (SAMs) as the intermediate layers on the surface of the AlOx dielectric, and the electrical performances of the organic charge modulated transistor (OCMFET) were significantly improved. The organic intermediate layer was applied to control the surface energy of the AlOx gate dielectric acting as a capacitor plate between the control gate (CG) and the floating gate (FG). By applying the intermediate layers on the gate dielectric surface, and the field-effect mobility (μ_OCMFET) of the OCMFET devices could be efficiently controlled. We used the four kinds of SAM materials, octadecylphosphonic acid (ODPA), butylphosphonic acid (BPA), (3-bromopropyl)phosphonic acid (BPPA), and (3-aminopropyl)phosphonic acid (APPA), and each μ_OCMFET was measured at 0.73, 0.41, 0.34, and 0.15 cm2V-1s-1, respectively. The results could be suggested that the characteristics of each organic SAM intermediate layer, such as the length of the alkyl chain and the type of functionalized end-group, can control the electrical performances of OCMFET devices and be supported to find the optimized fabrication conditions, as an efficient sensing platform device.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.7
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• pp.1074-1081
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• 2021

Nitrous oxide (N₂O) is one of the six major greenhouse gases and is known to produce a greenhouse ef ect by absorbing infrared radiation in the atmosphere. In particular, its global warming potential (GWP) is 310 times higher than that of CO₂, making N₂O a global concern. Accordingly, strong environmental regulations are being proposed. N₂O reduction technology can be classified into concentration recovery, catalytic decomposition, and pyrolysis according to physical methods. This study intends to provide information on temperature conditions and reaction time required to reduce nitrogen oxides with cost. The high-temperature ranges selected for pyrolysis conditions were calculated at intervals of 100 K from 1073 K to 1373 K. Under temperatures of 1073 K and 1173 K, the N₂O reduction rate and nitrogen monoxide concentration were observed to be proportional to the residence time, and for 1273 K, the N₂O reduction rate decreased due to generation of the reverse reaction as the residence time increased. Particularly for 1373 K, the positive and reverse reactions for all residence times reached chemical equilibrium, resulting in a rather reduced reaction progression to N₂O reduction.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.338-350
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• 2022

Purpose: Various studies have investigated 3-dimensional (3D)-printed implants using Ti6Al-4V powder; however, multi-root 3D-printed implants have not been fully investigated. The purpose of this study was to explore the stability of multirooted 3D-printed implants with lattice and solid structures. The secondary outcomes were comparisons between the 2 types of 3D-printed implants in micro-computed tomographic and histological analyses. Methods: Lattice- and solid-type 3D-printed implants for the left and right mandibular third premolars in beagle dogs were fabricated. Four implants in each group were placed immediately following tooth extraction. Implant stability measurement and periapical X-rays were performed every 2 weeks for 12 weeks. Peri-implant bone volume/tissue volume (BV/TV) and bone mineral density (BMD) were measured by micro-computed tomography. Bone-to-implant contact (BIC) and bone area fraction occupancy (BAFO) were measured in histomorphometric analyses. Results: All 4 lattice-type 3D-printed implants survived. Three solid-type 3D-printed implants were removed before the planned sacrifice date due to implant mobility. A slight, gradual increase in implant stability values from implant surgery to 4 weeks after surgery was observed in the lattice-type 3D-printed implants. The marginal bone change of the surviving solid-type 3D-printed implant was approximately 5 mm, whereas the value was approximately 2 mm in the lattice-type 3D-printed implants. BV/TV and BMD in the lattice type 3D-printed implants were similar to those in the surviving solid-type implant. However, BIC and BAFO were lower in the surviving solid-type 3D-printed implant than in the lattice-type 3D-printed implants. Conclusions: Within the limits of this preclinical study, 3D-printed implants of double-rooted teeth showed high primary stability. However, 3D-printed implants with interlocking structures such as lattices might provide high secondary stability and successful osseointegration.