• Title/Summary/Keyword: effective strength

Search Result 3,804, Processing Time 0.029 seconds

Mechanical Performance Evaluation of RC Beams with FRP Hybrid Bars under Cyclic Loads (FRP 하이브리드 보강근을 가지는 RC보의 반복하중에 대한 역학적 성능 평가)

  • Hwang, Chul-Sung;Park, Jae-Sung;Park, Ki-Tae;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.21 no.1
    • /
    • pp.9-14
    • /
    • 2017
  • In the present work, a mechanical performances under cyclic loading in RC (Reinforced Concrete) beams with normal steel and FRPH (Fiber Reinforced Plastic Hybrid) bar are investigated. For the work, RC beam members with $200{\times}200{\times}2175mm$ of geometry and 24 Mpa of design strength are prepared, and 4-point-bending tests are performed for evaluation of cracking, yielding, and ultimate loads. Through static loading test, 48.9kN and 36.0 kN of yielding loads are measured for normal RC and FRPH beam, respectively. They have almost same ultimate load of 50.0 kN. Typical tension hardening behavior is observed in FRPH beam, which is caused by the behavior of FRPH bar with tension hardening. In cyclic loading conditions, FRPH beam has more smaller crack width and scattered crack pattern, and it shows more elastic recovery than normal RC beam. The energy dissipation ratio in FRPH beam is 0.83, which is greater than 0.62 in normal RC beam and it shows more effective resistance to cyclic loadings.

Exploring the organic harmony of the Modern Pentathlon of sports

  • Han, Doryung
    • Journal of the Korea Society of Computer and Information
    • /
    • v.25 no.8
    • /
    • pp.99-109
    • /
    • 2020
  • What sports have in common is that they must use their bodies to play and lead to victory. The use of the body differs in many ways depending on the event, which part should be used as the focus. The commonality of all sports is that sports can achieve the best results by using and using parts of the body in harmony. The use of strength or muscles varies depending on the type of sport or the type of sport, so the use of the body or the results of athletic events also varies. Sports are premised on the organic use of the body, but the implications of sports can be found in that the degree of organic use does not apply equally to all sports. Sports demand organic balance and flexibility. Depending on the type of sport, you can explore which organic harmony produces more effective effects and find out which events are more beneficial to the human body. This study aimed to find out whether the organic harmony of the body actively contributes to the development of sports and a healthy mental culture. In this study, we proposed the hypothesis that the modern Pentathlon will induce the most desirable organic harmony as a global Olympic sport, and tried to verify that the hypothesis is valid and verifiable. In order to do this study, I tried to find out the organic viewpoints centered on the Miletos school, re-examine the meaning of the modern Pentathlon of games as an Olympic event, and conduct organic harmony and exploration of the modern Pentathlon of games in terms of sports.

The Analysis of Korean Medicine Treatment for Idiopathic External Ophthalmoplegia (특발성 외안근마비의 한의학적 치료 경향 분석)

  • Lee, Su-Kyung;Kang, Ju-Young;Lee, Seung-Hee;Hong, Hyeon-Jin;Hwang, Doo-Ree;Choi, Hyun-Min;Lee, Chang-Won
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
    • /
    • v.30 no.3
    • /
    • pp.119-133
    • /
    • 2017
  • Objectives : This study is designed for analysis of trend and curative effect of Korean medicine for idiopathic external ophthalmoplegia. Methods : Research studies related to objectives were gathered through OASIS and KTKP and analyzed. Results : 21 case reports were selected. 5 korean medicine therapies, Herb, acupuncture, moxibustion, electroacupuncture, and pharmacopuncture, were executed. Restorative herb including Bojungikki-tang was frequently used in herb therapy. Facial and cephalic acupoints and non-facial, non-cephalic acupoints which individually differ were mostly simultaneously executed as acupuncture therapy. Also, moxibustion was partly performed. Electroacupuncture was carried out to affected area with electric stimulation at the strength of 1Hz and 4Hz. Hominis placental pharmacopuncture, 0.1cc or 0.5cc for each acupoint, was injected on disease area. After analyzing number of Korean medicine treatment and period of Korean medicine treatment from 21 case reports, the recovery period of idiopathic external ophthalmoplegia, 36.6 treatment session/36.69 days, was assessed to be more than one month shorter than previously known recovery period. Number of treatment sessions and treatment period for 11 cases when pharmacopuncture or electroacupunture was applied were 10/29, 35/29.96, which was 15 days shorter in terms of treatment period and 10 times less in terms of number of treatment sessions compared to cases when pharmacopuncture or electroacupunture was not applied. Conclusions : Korean medicine treatment can be effective for recovery of idiopathic external ophthalmoplegia.

Effects of Dietary Supplementation of Powdered Mulberry Leaves on Egg Production, Egg Quality and Blood Characteristics in Laying Hens (산란계 사료에 뽕잎 분말 첨가 급여가 산란율, 계란 품질 및 혈액 성상에 미치는 영향)

  • Park, Chang-Ill;Kim, Young-Jik
    • Korean Journal of Poultry Science
    • /
    • v.39 no.3
    • /
    • pp.215-222
    • /
    • 2012
  • This study was conducted to investigate the effects of supplementation diets of powdered mulberry leaves on egg production, egg quality and blood characteristics in laying hens. Laying hens were fed diets for 30 days containing 0% powdered mulberry leaves (Control), 1% powdered mulberry leaves (T1), 2% powdered mulberry leaves (T2), and 5% powdered mulberry leaves (T3). The egg production, yolk weight and albumen weight were no significant difference among treatment groups. The albumen weight was significantly decreased by the supplementation of powdered mulberry leaves in all treatment groups (P<0.05). The albumen high, yolk color score, egg sell thickness and egg shell breaking strength were no significant difference. The total cholesterol and triglyceride concentration of control was higher than T3, and the high density lipoprotein (HDL)-cholesterol concentration and glucose of control were lower than treatment groups (P<0.05). The white blood cell (WBC) was significantly increased by the supplementation of powdered mulberry leaves compared to the control (P<0.05). In conclusion, these data indicate that 5% powdered mulberry leaves supplementation was most effective in decreasing total cholesterol and triglyceride and increasing HDL-cholesterol, glucose and WBC.

Dielectric Properties of Semi-IPN Poly(phenylene oxide) Blend/$BaTiO_3$ Composites with Type of Cross-linker (가교체 종류에 따른 Semi-IPN Poly(phenylene oxide) 블렌드와 $BaTiO_3$ 복합재료의 유전특성)

  • Jang, Yong-Kyun;Lee, Ho-Il;Seong, Won-Mo;Park, Sang-Hoon;Yoon, Ho-Gyu
    • Polymer(Korea)
    • /
    • v.33 no.3
    • /
    • pp.224-229
    • /
    • 2009
  • The dielectric properties of semi-IPN poly(phenylene oxide)(PPO) blend/$BaTiO_3$(BT) composites are investigated. The composites are fabricated via melt-mixing of crosslinker and peroxide in precursor PPO composite obtained by precipitating the suspension consisted of PPO, BT and toluene into methylethyl ketone, poor solvent of PPO. The permittivity of the precursor PPO composites shows higher value than that of integral-blended PPO composites by extruder and coincides with the theoretical value calculated by logarithmic rule of mixture. The blend of PPO and cross-linked triallyl isocyanurate is most effective for lowering the permittivity and loss tangent owing to the suppression of the orientation polarization of matrix. In contrast, 4,4'-(1,3-phenylene diisopropylidene) bisaniline, which has amine unit in its structure, increases the permittivity as well as loss tangent of the composite, but it has the ability to densify the matrix resin and the interfacial adhesion between the matrix and filler to improves flexural strength and modulus.

Research on Fire Safety of Mortar-Containing Waste Tire Powders and Flame Retardant (폐타이어 분말과 난연제가 혼입된 모르타르의 화재안전에 관한 연구)

  • Park, Jeong-Jin;Son, Ki-Sang
    • Fire Science and Engineering
    • /
    • v.24 no.4
    • /
    • pp.12-17
    • /
    • 2010
  • The purpose of this study is to determine how effectively waste tire recycled material mixed with flame retardant work in combating fire. As discovered in the previous study, waste tire mixed with cement mortar has more insulation capacity. However, this mortar is weak against fire. Therefore flame retardant, with a specific proportional mix, will be added to increase its fire prevention capacity. Tests will be made in accordance with ISO 5657 procedures for measuring fire ignition time, flame and shape variation of test pieces at the Building Material Test Institute. The test piece will be set up with horizontal levels having a constant radiation heat of $1{\sim}5W/cm^2$. Temperature transfers and increases from the surface into the interior. Combustible gases result due to pyrolysis, and regular contact is maintained between the fire source and the center of the test piece for assessment purposes. Ignition has not been occurred without adding retardant meaning that there is almost no possibility of ignition of waste tire particle. This fact can be considered as fire load to appreciate a volume of combustion materials. Flame is not occurred due to heat-absorbing effect by adding non-organic series retardant into waste tire particle. Conclusions have been summarized as follows; 1) Combustion of building material can be decreased by adding retardant to waste tire-mixing mortar. But compressive strength and insulation capacity of the material should be measured later. 2) Firing prevention and ignition are main points of building fire. Reasonable fire engineering assessment of interior material should be made for establishing effective disaster prevention system.

Study on the Development of Putty According to Epoxy Resin Hardener (Epoxy 수지 경화제에 따른 Putty 개발에 관한 연구)

  • Oh, Seung-Jun;Cheong, Da-Som;Park, Gi-Jung;Wi, Koang-Chul
    • Journal of Conservation Science
    • /
    • v.31 no.2
    • /
    • pp.105-114
    • /
    • 2015
  • In this study, an advanced epoxy putty which was as a multi-purpose restoration material being used to restore missing parts in the artifact preservation treatment process was developed. For the purpose of addressing the issues including the workability issue resulting from high strength, the drooping issue resulting from long hardening time during work process and the issue of contaminating the surface of artifact resulting from stained material on tools or gloves, a property comparison was conducted with existing materials to examine the properties of restoration materials in the form of epoxy putty currently being frequently used. For the purpose of addressing the issues of existing materials and allowing the developed epoxy putty to have similar properties, two types of hardeners with different properties were selected to conduct property experiments. As for the hardeners, mercaptan type hardener and aliphatic amine type hardeners in the total of two types were selected for the development. The result showed that the two types were both in the form of paste and their hardening time of 5-10 minutes were about 3-10 times shorter than that of existing materials, thereby improving the work convenience. In terms of abrasion rate to increase workability, it was improved by about 3 times to allow effective and convenient use. As for the issue of contaminating the artifact surface during the process, white micro-balloon was added as filler to address the issue to reduce the oil ingredient to develop multi-purpose restoration material with low shrinkage & high workability in coloring, light weight and cutting force.

Effects of 24-week Swimming Program on the Health Related Physical Fitness, Stress Hormones and Immune Functions in Adults with Intellectual Disabilities (24주간의 수영프로그램이 성인 지적장애인의 건강체력, 스트레스 호르몬 및 면역기능에 미치는 영향)

  • Park, Chan-Ho;Bae, Hye-Young;Cheon, Ji-Un
    • Journal of the Korean Applied Science and Technology
    • /
    • v.37 no.3
    • /
    • pp.551-563
    • /
    • 2020
  • The purpose of this study was to identify the characteristics of health-related indicators according to the participation of swimming program by adults with intellectual disabilities(ID). To this end, 20 adults with IDs, aged 20-39 living in Busna, were selected. Participants divided into two groups: swimming program participation(n=10) and non-participation(n=10). Data were collected by measuring the subjects health-related physical fitness, stress hormones, and immune function and data analysis was conducted using SPSS 18.0, paired t-test, independent t-test and two-way ANOVA. As a result, muscle strength(p<.001), muscular endurance(p<.001), flexibility(p<.001), cardiovascular endurance(p<.01) improvement of exercise group significantly but there was no significant difference in the control group. The stress hormone cortisol(p<.01) was significantly decreased in the exercise group and there was no significant difference in the control group. The immunoglobulins, IgA(p<.05), IgG(p<.001), IgM(p<.05) were significantly increased in the exercise group, but not significantly different in the control group. Therefore, regular swimming program can be said to be a very effective exercise program for improving the physical fitness of adults with IDs, and it is thought that it can reduce stress and help improve immune function. This suggests the need for active physical activity program development and intervention to maintain the health of adults with IDs and prevent chronic diseases.

Ginsenoside Rg3-enriched red ginseng extract inhibits platelet activation and in vivo thrombus formation

  • Jeong, Dahye;Irfan, Muhammad;Kim, Sung-Dae;Kim, Suk;Oh, Jun-Hwan;Park, Chae-Kyu;Kim, Hyun-Kyoung;Rhee, Man Hee
    • Journal of Ginseng Research
    • /
    • v.41 no.4
    • /
    • pp.548-555
    • /
    • 2017
  • Background: Korean Red Ginseng has been used for several decades to treat many diseases, enhancing both immunity and physical strength. Previous studies have documented the therapeutic effects of ginseng, including its anticancer, antiaging, and anti-inflammatory activities. These activities are mediated by ginsenosides present in the ginseng plant. Ginsenoside Rg3, an effective compound from red ginseng, has been shown to have antiplatelet activity in addition to its anticancer and anti-inflammatory activities. Platelets are important for both primary hemostasis and the repair of the vessels after injury; however, they also play a crucial role in the development of acute coronary diseases. We prepared ginsenoside Rg3-enriched red ginseng extract (Rg3-RGE) to examine its role in platelet physiology. Methods: To examine the effect of Rg3-RGE on platelet activation in vitro, platelet aggregation, granule secretion, intracellular calcium ($[Ca^{2+}]_i$) mobilization, flow cytometry, and immunoblot analysis were carried out using rat platelets. To examine the effect of Rg3-RGE on platelet activation in vivo, a collagen plus epinephrine-induced acute pulmonary thromboembolism mouse model was used. Results: We found that Rg3-RGE significantly inhibited collagen-induced platelet aggregation and $[Ca^{2+}]_i$ mobilization in a dose-dependent manner in addition to reducing ATP release from collagen-stimulated platelets. Furthermore, using immunoblot analysis, we found that Rg3-RGE markedly suppressed mitogen-activated protein kinase phosphorylation (i.e., extracellular stimuli-responsive kinase, Jun N-terminal kinase, p38) as well as the PI3K (phosphatidylinositol 3 kinase)/Akt pathway. Moreover, Rg3-RGE effectively reduced collagen plus epinephrine-induced mortality in mice. Conclusion: These data suggest that ginsenoside Rg3-RGE could be potentially be used as an antiplatelet therapeutic agent against platelet-mediated cardiovascular disorders.

Propagation of asymbiotically germinated seedlings with liquid culture for endangered lady's slipper orchid (Cypripedium macranthos Sw.) (액체배양 방법을 이용한 멸종위기종 복주머니란 종자 무균발아 및 증식)

  • Lee, Joung Kwan;Huh, Yoon Sun;Park, Sang Im;Park, Jae Seong;Jeong, Mi Jin;Son, Sung Won;Suh, Gang Uk
    • Proceedings of the Plant Resources Society of Korea Conference
    • /
    • 2018.04a
    • /
    • pp.45-45
    • /
    • 2018
  • We had already reported the successful germination for green pods of purple lady's slipper orchid (Cypripedium macranthos Sw.). The green pod methods is to take immature seeds in green capsules, sterilize the capsule, and take out the sterile seeds. This method, however, needs very critical time of harvest. The critical time of seed harvest changes depending upon the species, condition of the specimen, and climatic influence, and the right time lies between 5 and 12 weeks after fertilization. In this study, the mature seeds were collected after 120-130 days with hand-polination of lady's slipper orchids. Mature seeds are usually dormant and it has to be overcome, either with hormone or storing the seeds near freezing for two or three months to break dormancy. The seeds were first surface sterilized with 70% ethanol and then transferred 1% NaOCl for 10-15 minutes, followed by rinses 3 times with sterilized distilled water. The cypripedium seeds consists of an embryo within a seed coat known as a testa. The testa is water repellent and the seed has a large air space between the embryo and testa so the seed tends to float on water. We had resolved the problems with vacuum pump to soak water into the testa before sterilization. The seeds were placed on liquid or agar solidified germination media. Cultures were incubated at $24{\pm}1^{\circ}C$ in dark. The seeds were germinated in 6-8 weeks in liquid suspension culture (germination percentage over 18%); however, the seeds on agar solidified media took more than 5 months to germinate and the germination percentage less than 5%. The most effective media for liquid culture was 1/4 strength Murashige and Skoog (MS) medium with 50 ml/l coconut water ($4brix^{\circ}$) at pH 5.8.

  • PDF