• Title/Summary/Keyword: and elasticity

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Study of Skin Elasticity and Wrinkle Properties of Elderly Female according to Sasang Constitution-based Health State (고령자 여성의 체질건강수준에 따른 피부 탄성 및 주름 특성 연구)

  • Kim, Young-Min;Jung, Chang-Jin;Ku, Bon-Cho;Jeon, Young-Ju;Kim, Keun-Ho;Kim, Jong-Yeol;Kim, Jaeuk U.
    • Korean Journal of Oriental Medicine
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    • v.18 no.3
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    • pp.119-126
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    • 2012
  • 1. Objectives Sasang constitutional medicine is unique in Korean traditional medicine. It diagnoses and treats patients based on his/her Sasang constitution (SC). Skin properties have been used as an effective diagnostic component in the classification of SC types in clinics. In this paper, we investigated the SC-based health relevance of skin elasticity and wrinkle properties. 2. Methods The skin elasticity and wrinkle of forearm and dorsal hand were measured in 299 elderly female subjects. To determine the subject's Sasang constitution, we adopted the classification results from a newly developed SC diagnostic tool. The health states of the subjects were scored by two Korean traditional medical doctors, by whom each subject was categorized either into the healthy state or the unhealthy state. 3. Results As a result, the elasticity hysteresis of forearm (E_HYS), the visco-elasticity (VE_MEAN), and the wrinkle frequency energy of backhand (W_HAND) showed significant differences between Taeum-in group and Soeum-in group. In case of the Soeum-in on unhealthy state, VE_MEAN was decreased significantly (p<.05). W_HAND and W_ARM_H of the healthy Taeum-in were less than those of the unhealthy Taem-in. 4. Conclusions In this study we showed that, for an elderly female population, skin elasticity and viscosity were significantly different not only between each SC type but also between healthy group and unhealthy group in each constitution. In particular, Soeum-in subjects were inferred to be superior in retaining skin softness when they were healthy, and Taeum-in subjects were easy to lose their firmness of skin surface when they became unhealthy.

Estimation of Modulus of Elasticity in High Strength Concrete (고강도 콘크리트의 탄성계수 추정)

  • Oh, Min-Ho;Kim, Tae-Wan;Choi, Jin-Woong;Cui, Jie;Kim, Hyung-Jun;Park, Sun-Kyu
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.413-414
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    • 2010
  • Many researchs shows that modulus of elasticity in manual overestimates real modulus of elasticity of concrete as strength gets higher. In 2007 KCI Manual, formula in modulus of elasticity has revised that it should be demonstrated. In this study, modulus of elasticity in high strength was estimated by experiment and experimental value was compared with manual value.

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Comparison of Energy Efficiency by Production Frontier Approach: Based on OECD Countries (생산 프론티어 접근을 통한 에너지효율 비교: OECD 국가를 중심으로)

  • Kang, Sangmok;Kim, Haechang
    • Environmental and Resource Economics Review
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    • v.20 no.1
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    • pp.33-60
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    • 2011
  • The purpose of the article is to compare the impacts of energy efficiency and economic growth for energy demand through production frontier approach in OECD countries. We compared the traditional energy intensity with energy efficiencies of production frontier approach, slack efficiency on the frontier, and estimated elasticity of energy demand for GDP growth. First, the energy intensity has a low relationship with energy efficiency by radial approach, but has constant correlations with slack energy efficiency, slack-adjusted efficiency by non-radial approach, and energy efficiency by horizon approach. If we measure energy efficiency only with energy elasticity, it may make a mistake. Especially the energy efficiency by radial approach has a tendency to overestimate most OECD countries. Second, as many countries have excess energy consumption of 17.3% even on the points of the frontier, reduction of energy consumption is necessary in addition. Third, the average energy elasticity of OECD countries is 1.1 close to elasticity 1. There exists the difference of elasticity among countries and the energy demands are also high in countries with high elasticity.

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Influence of Grit and Self-elasticity on Carrer Identity of Nursing Students (간호대학생의 자아탄력성, 그릿이 진로정체감에 미치는 영향)

  • Yun Mi Jin;Jin Hye Kyung
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.6
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    • pp.1135-1141
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    • 2023
  • The purpose of this study was to investigate the effect of Grit and Self-elasticity on Carrer Identity of nursing students. Data were collected among 193 nursing students in G city, from Sep 4 to 15 2023. The collected data was analyzed a using t-test, One way ANOVA, Pearson correlation coefficient and Stepwise multiple regression using SPSS 20.0 WIN program. The results revealed that the average score for Self-elasticity was 3.42±0.45, Grit was 3.63±0.60, Carrer Identity was 4.06±0.79. students acquired Self-elasticity by gender as per general characteristics. The Carrer Identity showed statistically significant differences in gender. There was a statistically significant positive correlation between the Carrer Identity of Self-elasticity(r=.370, p=.000), and Grit(r=.283, p=.000). Carrer Identity showed Models including the variables, Self-elasticity, Gender, Grit explained 22.6% of the variance in the Carrer Identity stress. Based on the outcome of this study, steps should be taken to design intervention program that emphasize a improve Carrer Identity for nursing students.

Comparison of flexural strength and modulus of elasticity in several resinous teeth splinting materials (여러 레진계 치아고정 재료의 굴곡강도 및 탄성계수 비교)

  • Yoo, Je-In;Kim, Soo-Yeon;Batbayar, Bayarchimeg;Kim, Jin-Woo;Park, Se-Hee;Cho, Kyung-Mo
    • Journal of Dental Rehabilitation and Applied Science
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    • v.32 no.3
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    • pp.169-175
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    • 2016
  • Purpose: Direct splinting material should have high flexural strength to withstand force during mastication and low modulus of elasticity to provide some movement while force applied for relief of stress. The purpose of this study was to compare flexural strength and modulus of elasticity of several resinous splinting materials. Materials and Methods: Four materials; Super-Bond C&B, G-FIX, G-aenial Universal Flo, FiltekTM Z350 XT; were used in this study. Fifteen rectangular bar specimens of each material were prepared. Three-point bending test were performed to determine physical properties. Maximum load at fracture was recorded and flexural strength and modulus of elasticity were calculated. One-way analysis of variance (ANOVA) and Scheffe's tests at a 0.05 level of significance were conducted on all test results. Results: Statistical analysis reveals that Super-Bond C&B had significant low mean value for flexible strength and the other three materials showed no significant difference. For modulus of elasticity, Super-Bond C&B exhibited statistically lower modulus of elasticity. G-FIX presented intermediate result, showing statistically higher modulus of elasticity than Super-Bond C&B but lower than G-aenial Universal Flo and FiltekTM Z350 XT. There was no significant difference on modulus of elasticity between G-aenial Universal Flo and FiltekTM Z350 XT. Conclusion: Using a G-FIX, the newly commercially available splinting material, which shows higher fracture resistance properties comparable to flowable and restorative composite resin and a relatively flexible nature might be a beneficial for stabilizing teeth mobility.

Substitution elasticities of the imported and domestically produced pulp and paper (수입펄프.종이와 국산펄프.종이의 대체탄력성)

  • Kim, Se-Bin;Kim, Dong-Jun
    • Korean Journal of Agricultural Science
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    • v.38 no.2
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    • pp.383-391
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    • 2011
  • Traditional international trade theory assumes that import goods and domestically produced goods of the same industry are equal in quality. However the substitutability of the two goods is imperfect. This article estimated the import functions of pulp and paper using econometric and vector autoregressive models, and calculated the elasticities of substitution between imported and domestically produced pulp and paper. The import of pulp is inelastic to import price and domestic price, and elastic to national income in econometric model. And it is inelastic to import price, domestic price and national income in vector autoregressive model. On the other hand, the import of paper is inelastic to domestic price, and elastic to import price and national income in econometric model. And it is inelastic to import price and domestic price, and elastic to national income in vector autoregressive model. The elasticity of substitution between imported and domestically produced pulp was positive, and the elasticity was respectively 0.42 and 0.20 in econometric and vector autoregressive models. This may be because of the high proportion of imports. On the other hand, the elasticity of substitution between imported and domestically produced paper was positive, and the elasticity was respectively 0.75 and 0.81 in econometric and vector autoregressive models. This may be because the quality of imported paper is different from that of domestically produced paper.

Study on Skin Elasticity Property between Face and Forearm according to the Environmental Change of Stratum Corneum (각질층 환경변화에 따른 얼굴과 하박내측 피부의 탄력 특성 비교연구)

  • Chang, Minyoul
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.4
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    • pp.455-463
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    • 2018
  • Skin elasticity has been known to be influenced by the change of dermal components such as collagen, elastic fiber, and glycosaminoglycans. However, it is unclear whether the uppermost epidermis may affect the mechanical characteristics of elasticity. In present study we tried to find the role of stratum corneum when determining the elastic property under skin bioengineering measurement with $Cutometer^{(R)}$. A total of 10 healthy volunteers aged 25-40 years were investigated by the parameters reflecting the skin elasticity from face and volar forearm. Within various ranges of suction pressure, R0 (=Uf), R7 (=Ur/Uf) and R8 (=Ua) were obtained to explore the depth-associated elasticity. In addition, these parameters were re-measured after the skin was fully hydrated. As results, we found that the measurement of depth-associated elasticity was possible as using various suction pressure. And the R7 parameter was significantly lower from face than those from forearm in before hydration (p < 0.05). Also, we found that the hydration of stratum corneum could affect skin elasticity. Especially, the R7 parameter at 300 mbar suction pressure of face skin showed significantly increased values than that of before hydration (p < 0.05). Interestingly, measured data from the face before and after hydration manifested relatively higher variation than from the forearm. These results suggest that it is possible to evaluate the skin elasticity considering the changes of stratum corneum and epidermis by using various suction pressure and skin hydration.

A discussion on simple third-order theories and elasticity approaches for flexure of laminated plates

  • Singh, Gajbir;Rao, G. Venkateswara;Iyengar, N.G.R.
    • Structural Engineering and Mechanics
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    • v.3 no.2
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    • pp.121-133
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    • 1995
  • It is well known that two-dimensional simplified third-order theories satisfy the layer interface continuity of transverse shear strains, thus these theories violate the continuity of transverse shear stresses when two consecutive layers differ either in fibre orientation or material. The third-order theories considered herein involve four/or five dependent unknowns in the displacement field and satisfy the condition of vanishing of transverse shear stresses at the bounding planes of the plate. The objective of this investigation is to examine (i) the flexural response prediction accuracy of these third-order theories compared to exact elasticity solution (ii) the effect of layer interface continuity conditions on the flexural response. To investigate the effect of layer interface continuity conditions, three-dimensional elasticity solutions are developed by enforcing the continuity of different combinations of transverse stresses and/or strains at the layer interfaces. Three dimensional twenty node solid finite element (having three translational displacements as degrees of freedom) without the imposition of any of the conditions on the transverse stresses and strains is also employed for the flexural analysis of the laminated plates for the purposes of comparison with the above theories. These shear deformation theories and elasticity approaches in terms of accuracy, adequacy and applicability are examined through extensive numerical examples.

THE TENSILE BOND STRENGTH AND ELASTIC MODULUS OF THE SOFT DENTURE LINING MATERIALS (연성 의치상 이장재의 인장결합 강도와 탄성계수에 관한 연구)

  • Kim, Byung-Jin;Koh, Jun-Won;Lee, Yong-Keun;Cho, Hye-Won
    • The Journal of Korean Academy of Prosthodontics
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    • v.35 no.3
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    • pp.458-469
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    • 1997
  • This study was to compare the tensile bond strength and flexibility of four different soft liners(Coe-Soft, Soft Relining, Soft-Liner, Dura Base Soft) before & after thermocycling. Each soft liner was bonded to denture base resin block, and measured the tensile bond strength and modulus of elasticity using Universal testing machine. The mean value of tensile bond strength and modulus of elasticity for each experimental groups were statistically processed by SPSS(Statistical Package of Social Science). The obtained results were as follows : 1. Dura Base Soft had the highest tensile bond strength and Coe-Soft had the lowest tensile bond strength. 2. Coe-Soft had the lowest modulus of elasticity, and Dura Base Soft had the highest modulus of elasticity. 3. Thermocycling had no effects on the tensile bond strength and modulus of elasticity of all the soft liners. 4. The failure modes of Coe-Soft, Soft Relining, Soft Liner were mainly cohesive failure, and that of Dura Base Soft were mainly adhesive failure.

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Aging-related Changes of the Mechanical Properties of the Erector Spinae Muscles in Young and Elderly Men (청년과 노인 남성 척주세움근의 노화에 따른 물리적 성질 변화)

  • Lee, Na-Kyung
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.4
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    • pp.39-47
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    • 2021
  • Purpose : This study aimed to investigate age-related mechanical changes in the erector spinae muscles, specifically in terms of tone, elasticity, and stiffness, in the elderly population compared to the younger population Methods : The mechanical properties, including tone, elasticity, and stiffness, of the erector spinae muscles were measured using myotonometry in 47 male adult subjects, divided into the younger group (23 subjects aged 19 to 28 years) and the elderly group (22 subjects aged 69 to 83 years). The measurements were performed in both the prone and sitting positions. The tone, elasticity, and stiffness of the erector spinae muscles were statistically compared between the two groups using a t-test. Results : The study showed increased stiffness and decreased elasticity in the erector spinae muscles in the elderly group compared to the younger group (p<0.01~0.001). The results were similar in both the prone and sitting positions. Conclusion : There are age-related degenerative changes that affect the mechanical properties of the erector spinae muscles. In addition, myotonometry can be suggested to be a useful examination tool in evaluating these changes provided that further studies are conducted and standard methods of application have been established in the future.