Earticle

Background: Dietary manipulation is a common practice to mitigate gaseous emission from livestock production facilities, and the variation of fat level in the diet has shown great influence on ruminal volatile fatty acids (VFA) and enteric methane generation. The changes in dietary fat levels influence rumen chemistry that could modify manure nutrient composition along with odor and gaseous emissions from manure management facilities. Methods: A field experiment was carried out on beef cattle feedlots to investigate the effect of four levels of dietary fat concentrations (3 to 5.5 %) on the manure composition and gaseous emissions (methane-CH4, nitrous oxide-N2O, carbon dioxide-CO2 and hydrogen sulfide-H2S) from the feedlot pen surface. The experiment was carried out over a 5-month period from June to October during North Dakota’s summer-fall climatic condition. Air and manure sampling was conducted five times at a 20?30 day intervals. Results: Overall, this research indicated that fat levels in diet have no or little effect on the nutrient composition of manure and gaseous emission from the pens with cattle fed with different diet. Though significant variation of gaseous emission and manure composition were observed between different sampling periods, no effect of high fat diet was observed on manure composition and gaseous emission. Conclusions: It can be concluded that addition of fat to animal diet may not have any impact on gaseous emission and manure compositions.

Micro-columnar CsI(Tl) is the most popular scintillator material which is used for many indirect digital X-ray imaging detectors. The light scattering at the surface of micro-columnar CsI(Tl) scintillator was studied to find the correlation between the surface roughness and the resultant image resolution of indirect X-ray imaging detectors. Using a commercially available optical simulation program, Light Tools, MTF (Modulation Transfer Function) curves of the CsI(Tl) film thermally evaporated on glass substrate with different thickness were calculated and compared with the experimental estimation of MTF values by the edge X-ray image method and CCD camera. It was found that the standard deviation value of Gaussian scattering model which is determined by the surface roughness of micro-columns could certainly change the MTF value of image sensors. This model and calculation methodology will be beneficial to estimate the overall performance of indirect X-ray imaging system with CsI(Tl) scintillator film for optimum design depending on its application.

본 연구에서는 오일 폐수의 처리과정에서 여과 막의 오염을 최소화하기 위하여 폴리프로필렌 정밀여과 막을 화학적으로 표면개질 하였으며, 이 개질된 막의 성능을 측정하기 위하여 플럭스 실험 및 막의 동 전위를 측정하였다. 파울링을 개선하기 위하여, 폴리프로필렌 정밀여과 막을 화학적으로 개질 하였으며, 표면개질은 포름알데히드 및 수산화나트륨을 촉매로 하여 일정한 pH와 온도 하에서 행하였다. 표면개질을 통해 소수성 정밀여과 막은 친수성 막으로 변했다. 실험 결과에 따르면 개질된 폴리프로필렌 여과 막은 원래의 여과 막보다 훨씬 높은 투과 flux를 보였다. 표면개질 막의 제타전위 값은 pH가 증가할수록 더욱 음으로 하전되었다. 실험결과 표면개질 막의 제타전위 값은 pH 뿐만 아니라, 이온 강도 및 계면 활성제의 농도에 따라 변하였다. 개질 막의 제타 전위가 음의 값이 높을수록, 막의 투과율도 향상 되었다. SDS 농도가 증가함에 따라 제타전위의 값도 음의 값으로 증가하였다. SDS가 막의 표면장력을 낮춤으로써 오일의 부착에 영향을 주었다.

In this study, the surface modified microfiltration membrane was carried out with flux and electrokinetic measurements in order to reduce the fouling of membrane in the oil separation. The polypropylene membranes were chemically modified for improving flux on the surface with formaldehyde and sodium hydroxide catalysts. The hydrophobic polypropylene membranes changed surface to hydrophillic. The modified membrane showed much higher flux than the original polypropylene membrane. The zeta potentials were varied as the function of pH, ionic strength and concentrations in the presence of surfactants. The zeta potentials of the modified membrane were shifted to more negative values. The higher the negative value of the zeta potential, the higher the membrane permeation rate. The zeta potential results were affected by the increasing SDS concentrations. The SDS may affect the attachment of oil droplets by lowering the interfacial tension.

Purpose: The purpose of this study was to investigate the effects of core muscle strengthening training and core exercise on unstable support on the balance and posture alignment of 20s healthy college student METHODS: twelven college student were randomly assigned to perform core muscle training for six college student, and six college student were exercised on an unstable surface. Two groups were conducted three times a week for 30 minutes. Dynamic balance and posture alignment were measured before and after the experiment. Results: There was a statistically significant difference dynamic balance and posture alignment in the group trained on the unstable support surface (p<.05). Conclusion: Based on the results of this study, exercise on an unstable support surface is an effective method for improving posture alignment and dynamic balance in healthy adults in their twenties.

Purpose: The purpose of this study was to investigate the effects of core muscle strengthening training and core exercise on unstable support on the balance and performance of a shooter. Methods: Fourteen athletes were randomly assigned to perform core muscle strength training for seven athletes, and seven athletes were exercised on an unstable surface. Two groups were conducted three times a week for 20 minutes. Static balance, dynamic balance, and shooting scores were measured before and after the experiment. Results: There was a statistically significant difference in static balance, dynamic balance in the group trained on the unstable support surface (p<.05). Conclusion: Based on this experiment, it can be seen that the balance training of the shooter on the unstable support surface is more effective than the balance of other methods.

This study aimed to evaluate the effects of different revegetation methods on surface erosion of the devastated hillslopes of limestone quarry at Okgye, located in Baekdudaegan, Gangwon-do, South Korea. Four methods, namely the coir-net-method, geofiber-method, green-slope-soil-method, and latticed-frame-attaching-method, were applied to four survey plots (2 m × 2 m), and different parameters, e.g., coverage, vegetation (the number of species and population), soil hardness, soil humidity, and surface erosion were determined. The survey plots in each case were selected, considering the differences in their altitude and slope angles, for appropriate comparison of the effects. The results showed that surface erosion was lowest for the geofiber-method, and was followed by erosion in the plots in which the green-slope-soil-method, latticed-frame-attaching-method, and coir-net-method were applied. In addition, the coverage rates for the geofiber-method and the green-slope-soil-method were relatively higher compared to those for the latticed-frame-attaching-method and coir-net-method. The above results indicate that the geofiber-method and green-slope-soil-method are relatively more effective in promoting vegetation growth and in minimizing surface erosion by adhesion the base materials.

This research was carried out to investigated the effect of base paper and latex binder on printability and obtical properties of coated paper. Especially, it examined the effect of th pH of vase paper surface and functional groups of latices on the interactions between coating color components and on the structure of coated layer. It was found that the behavior of coating color containing amphoeric latex depends on the pH in the boundary region between coating color and base paper. Thus, the coating color formulated with amphoteric latex formed bulky coating layer by inducing stronger interaction between paper surface and coating components than the coating color with anionic latex. The coated paper with amphoteric latex showed better optical properties (i.e.gloss and optical) and printability (i.e. ink receptivity, wet ink receptivity, and ink set off) than the conventional anionic latex in the acidic and alkaline paper. However, dry pick strength of the coated paper was less decreased. This result indicated that amphoteric latex could also be applied practically to the alkaline paper.

본 연구의 목적은 정서노동의 하위요인인 표면행위 및 내면행위와 직무만족의 관계에서 정서지능으로 조절된 직무소진이 매개효과를 나타내는지 확인하여, 정서지능의 조절된 매개효과를 검증하는 데 있다. 이를 위해 증권사 지점 및 센터에서 근무하며 고객을 응대하는 288명의 직원을 대상으로 자료를 수집한 후, SPSS 23.0과 Mplus 7.0 프로그램을 활용하여 수집된 자료를 분석하였다. 본 연구에서 밝혀진 결과를 요약하면 다음과 같다. 첫째, 표면행위는 직무만족에 유의미한 영향을 주지 않는 것으로 나타났으며, 둘째, 내면행위는 직무만족에 유의미한 정적 영향을 주는 것으로 나타났다. 셋째, 표면행위는 직무소진에 유의미한 정적 영향을 미치며, 넷째, 내면행위는 직무소진에 유의미한 부적 영향을 미치는 것으로 나타났다. 다섯째, 직무소진은 직무만족에 유의미한 부적 영향을 미치는 것으로 나타났다. 여섯째, 표면행위 및 내면행위와 직무만족의 관계에서 직무소진의 매개효과가 모두 유의한 것으로 나타났다. 마지막으로, 내면행위와 직무만족의 관계에서 매개효과를 나타내는 직무소진이 정서지능에 의해 조절되는 것으로 나타나 정서지능의 조절된 매개효과가 확인되었으나, 표면행위에서는 정서지능의 조절된 매개효과가 나타나지 않았다. 연구 결과에 기초하여 본 연구의 의의 및 함의를 제시하였다.

The purpose of this study is to examine the moderated mediating effect of emotional intelligence on emotional labor(surface acting, deep acting) and job burnout on job satisfaction among securities branch clerks. A total of 288 securities clerks were asked to complete the questionnaires and the data were analyzed using SPSS 23.0 and Mplus 7.0. The results were as follows. First, surface acting had no significant effect on job satisfaction. Seocond, deep acting had significantly positive effect on job satisfaction. Third, surface acting were found to have significantly positive effect on job burnout. Fourth, deep acting were found to have significantly negative effect on job burnout. Fifth, job burnout is shown to have significantly negative effect on job satisfaction. Sixth, a mediating model showed that an association between surface acting and deep acting and job satisfaction were partially mediated by job burnout. Seventh, emotional intelligence showed the moderated mediating effect of deep acting and job burnout on job satisfaction. Finally, the implications and limitation of the present study are discussed.

A piece of coating color or base paper picked during printing is called coating pick. Loosely bonded materials of coating color or broken piece of fiber could be adhered to the blanket or would be mixed with ink during printing. Because the coating pick can make troubles in printing press such as piling, hickey and collecting, the coating pick of a paper has been one of the most serious problems in printing. In this paper, two influential factors to the coating pick in the printing, those are latex content and ash content of the coating color, are studied. The surface resistance of coating paper is directly proportional to the latex content, otherwise inversely proportional to the ash content. We propose a different way to evaluate the picking and used a homemade pick test device.

Purpose: To evaluate how alumina sandblasting (AL), with and without hydrofluoric (HF) acid etching, affects surface roughness and optical properties (ΔE00 and TP) used for laminate veneers. Methods: Thirty A2-shade nano-hybrid ceramic specimens were milled and finished to a thickness of 0.5±0.01 mm and allocated to three groups (n=10): AL, AL+5% HF (AL5), and AL+9.5% HF (AL9.5). Surface roughness (Ra) and optical properties (ΔE00, TP) were evaluated. Data normality and homoscedasticity were assessed, followed by Welch’s analysis of variance (ANOVA) with Dunnett T3 (Ra) and ANOVA with Tukey HSD (ΔE00, TP) at α=0.05. Field-emission scanning electron microscope/energy dispersive X-ray spectroscopy characterized surface and microstructural changes. Results: Mean±SD were as follows. Ra (μm): AL 2.86±0.54, AL5 2.43±0.26, and AL9.5 2.79±0.15 (p<0.05); ΔE00: AL 2.94±0.90, AL5 7.79±0.70, and AL9.5 8.81±0.64 (p<0.001); and TP: AL 28.40±1.00, AL5 23.62±0.86, and AL9.5 22.69±0.72 (p<0.001). Post-hoc analysis revealed that Ra differed only between AL5 and AL9.5. ΔE00 differed among all groups. For TP, differences were present for AL versus AL5 and AL9.5, but not between AL5 and AL9.5. Conclusion: At a veneer thickness of 0.5 mm, the addition of HF etching to AL significantly increases color change and reduces translucency, whereas roughness differences are modest and group-dependent. Increasing HF concentrations induce micro-porosity and silica dissolution that likely drive optical shifts.

This paper investigated how perceived organizational support(POS) has a moderating effect on the relationship between surface acting and emotional exhaustion and examined the mediating relationship between surface acting and job satisfaction via emotional exhaustion and tested moderated mediation model combining moderation model and mediation model. To test these research objectives, moderation analysis, mediation analysis and moderated mediation analysis were performed. A total of 214 hotel employees participated in this study. The results showed that surface acting were significantly related to emotional exhaustion which in turn significantly affected job satisfaction(mediation effect). And POS moderated the relationship between surface acting and emotional exhaustion such that emotional labor was related to more emotional exhaustion for employees who perceived less organizational support(moderation effect). In particular, POS moderated the negative and indirect effect of surface acting on job satisfaction through emotional exhaustion such that emotional exhaustion mediated the indirect effect only when POS was low but not when it was high(moderated mediation effect). These results suggest that organizational interventions aimed at improving POS when hotel employees experience surface acting would be valuable tools for organizational performance. Both theoretical and practical implications are discussed.

본 연구에서는 지르코니아의 새로운 표면처리 방법이 레진 시멘트와의 전단결합강도에 미치는 영향을 알아보고 자 하였다. 지르코니아 표면처리 방법 따라 5개의 그룹으로 분류하였다: 표면처리 미시행한 군(CON군), 100℃에서 9% 불산에 10분간 노출시킨 군(HF군), 15% 지르코니아 슬러리를 적용한 군(ZS15군), 30% 지르코니아 슬러리를 적용한 군(ZS30군), 50% 지르코니아 슬러리를 적용한 군(ZS50군). 표면처리한 지르코니아 위에 레진 시멘트를 적용하였고, 열 순환 처리 후 지르코니아와 레진 시멘트 간의 전단결합강도를 측정하였다. 전단결합강도에 대한 통계 방법으로 Kruskal-Wallis test와 Mann-Whitney U test 및 Boneferroni correction를 사용하였다(α=.05/10=.005). 지르코 니아 슬러리를 적용한 군은 CON군과 HF군에 비해 높은 전단결합강도를 보였다(p <.05/10=.005). 지르코니아 슬러리 를 이용한 표면처리 방법은 레진 시멘트와 지르코니아 간의 전단결합강도를 증대시킴을 확인하였다. 본 연구 결과, 새로 운 표면처리 방법은 지르코니아가 지닌 접착의 한계점을 보완하고 개선함으로써 지르코니아의 보다 다양한 임상적 적용 가능성을 기대할 수 있을 것으로 사료된다.

This study was to investigate the effect of the new surface treatment method of zirconia on the shear bond strength with resin cement. The zirconia specimens were classified according to the surface treatment. CON: non-treatment, HF: 10 minutes exposure to 9% HF, ZS15: Apply 15% ZrO2 slurry, ZS30: Apply 30% ZrO2 slurry, ZS50: Apply 50% ZrO2 slurry. The resin cement was layered on the surface treated zirconia, and the shear bond strength between the zirconia and the resin cement was measured after thermo-cycling. The statistical methods for shear bond strength were Kruskal-Wallis test, Mann-Whitney U test, and Bonferroni correction(α=.05/10=.005). ZS15, ZS30, and ZS50 groups treated with zirconia slurry showed higher shear bond strength than CON and HF groups(p <.05/10=.005). Within the limits of this study, the surface treatment using zirconia slurry increased the shear bond strength with resin cement. The new surface treatment method complements and improves the limitations of the adhesion of zirconia, so that various clinical applications of zirconia can be expected.

This study analyzes the internal temperature characteristics of heater module using a numerical method when the constant heat flux and heat flux time are applied to the surface heating element. The horizontal and vertical dimensions of heater module are 100mm, and the height is 5mm. The heat flux is 10,000W/m2, 15,000W/m2, and 20,000W/m2, and heat flux time is 5 seconds, 10 seconds, 15 seconds, 20 seconds, 30 seconds and 50 seconds, respectively. When the heat flux time was 50 seconds, the temperature of the surface heating element rose to 120.5°C, while the skin epidermis temperature rose 1.7°C. As a result, the surface temperature of the surface heating element increased greatly in the horizontal direction, while it increased low in the depth direction. This is because the heat conduction of the surface heating element is transmitted in the X-Y plane direction, and the thermal conductivity of the pet(polyethylene terephthalate) film and insulation sheet under the surface heating element is very low. when the heat flux at the surface heating element is 20,000W/m2, the skin's epidermal temperature rises up to 0.82℃ compared to 10,000W/m2 and 15,000W/m2.

본 연구는 뷰티 종사자들을 대상으로 감정노동(표면행위, 심층행위), 직무소진(정서적 고갈, 비인격화), 이직의도 간의 인과성에 관한 연구 이다. 이를 분석하기 위해 서울, 경기도에 소재하고 있는 사업체에 근무하는 뷰티 종사자들을 대상으로 설문조사를 실시하였다. 감정노동이 직무소진에 미치는 영향을 분석한 결과, 감정노동의 표면행위, 심층행위가 정서적 고갈과 비인격화에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 직무소진이 이직의도에 미치는 효과를 분석한 결과, 직무소진의 정서적 고갈, 비인격화가 이직의도에 유의한 정(+) 의 영향을 미치는 것으로 나타났다. 감정노동이 이직의도에 미치는 효과를 분석한 결과, 감정노동의 표면행위가 이직의도에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 서비스 종사자들은 MOT 과정에서 겪는 감정노동으로 인해 정신적으로 힘들게 되고 그것이 심화되면 정신 적·육체적으로 피로감을 느끼고 의욕을 상실한다. 결국에는 Burnout(번아웃) 상태가 되어 직장을 옮기려하거나 그만두는 것을 고려하게 된다. 시사점은 조직 차원에서 서비스 종사자들의 직무만족도를 높일 수 있는 복리증진 프로그램을 활성화하여 감정고갈의 회복력을 높이고 자 아효능감을 갖고 일할 수 있도록 그들의 감정을 관리하는 것이 중요하다.

This study is a study on the causality between emotional labor (surface acting, deep acting), job burnout (emotional exhaustion, depersonalization), and turnover intention among beauty workers. To analyze this, a survey was conducted targeting beauty workers working at businesses located in Seoul and Gyeonggi-do. As a result of analyzing the effect of emotional labor on job burnout, it was found that surface acting and deep acting of emotional labor had a significant positive effect on emotional exhaustion and depersonalization. As a result of analyzing the effect of job burnout on turnover intention, it was found that emotional exhaustion and depersonalization of job burnout had a significant positive effect on turnover intention. As a result of analyzing the effect of emotional labor on turnover intention, it was found that surface acting of emotional labor had a significant positive effect on turnover intention. Service workers become mentally exhausted due to emotional labor during the MOT process, and when this worsens, they feel mentally and physically tired and lose motivation. Eventually, they will become in a state of burnout and consider changing jobs or quitting. The implication is that it is important to activate welfare promotion programs that can increase the job satisfaction of service workers at the organizational level, increase their resilience to emotional exhaustion, and manage their emotions so that they can work with self-efficacy.

The purpose of this study was to investigate the effect of surface coefficient of restitution on vertical ground reaction force, joint angular velocity and muscle activity during landing with ankle, knee and hip joint angle limitation. 10 men were recruited as a subjects but only one person was excluded due to personal reason therefore a total of 9 men participated in this measurement. The participants were performed 30cm height drop landing on three different surface with randomized control and cross-over design. All subjects were performed four weeks drop landing to limit the joint angle during landing. Three-dimensional motion analysis equipment and surface EMG was used to measure ground reaction force, joint angles, joint angular velocity and muscle activity of lower limb. Collected data were statically analyzed by repeated one-way analysis of variance and alpha was set at .05. As a results, there were no significant difference between ground reaction force and joint angular velocity but there were significant difference in muscle activity and on wood had highest activity level than others. Based on the results of this study, further study needs to kinematic analysis and hormonal responses about a variety of surface coefficient and drop landing height followed by jump.

Purpose: The aim of this research was to investigate difference in shear bond strengths of full-contour zirconia layered with porcelain. Methods: Disk-shaped (diameter: 12.0mm; height:3.0mm) zirconia were randomly divided into six groups according to the surface conditioning method to be applied (N=90, n=15 per group): group 1-contol group(ZC); group 2- airborne particle abrasion with 50-um Al2O3(5A); group 3-50-um Al2O3 + liner(5AL), group 4-110-um Al2O3(1A); group 5-110-um Al2O3 + liner(1AL); group 6-liner(LC). On each block, zirconia porcelain was build up according to manufacturer’s instructions. All samples were fixed with measuring jigs and shear bond strength were measured with Universal testing machine. Collected data were analyzed using SPSS(Statistical Package for Social Sciences) Win 12.0 statistics program. Results: LC showed the highest value(29.92±2.55 MPa) and ZC showed the lowest value(13.22±1.37 MPa). Zirconia liner and Alumina oxide groups was significantly higher shear bond strength than control(p<0.05). 5A (without liner 22.18±2.37, with liner 22.84±1.74 MPa) was higher shear bond strength than 110 (without liner 20.18±2.38, with 20.71±2.67). Conclusion: Surface treatments may have advantage in bond strength improvement for full-contour zirconia layered with porcelain.

Purpose: To investigate shear bonding strength between dental zirconia ceramics with different surface treatment and metal bracket. Methods: Zirconia ceramics(LAVA, 3M ESPE, USA) were divided to 4 groups according to their surface treatment; no surface treatment(G1), sand blasting(G2), silane coating(G3), and sand blasting+silane coating(G4). Specimens were bonded to metal bracket using resin bond(TransbondTMXT, 3M Unitek, USA). Shear bond strength was measured using universal test machine(3366 INSTRON. U.S.A) with cross head speed of 1 mm/min. Microstructural investigation for fracture surface was performed after shear test. Results: Shear bonding strengths of single surface treatment groups (G2 and G3) were higher than no treatment group(G1). Combined Treatment Group (G4) showed the highest shear bond strength of 9.15 . Microstructural observation shows that higher shear bonding strength was obtained when debonding was occurred at metal bracket/resin interface rather than zirconia ceramic/resin interface. Conclusion: Surface treatment of zirconia is necessary to obtain higher bonding strength. Combined treatment can be more effective when surface the surfaces are kept clean and homogeneous.