• 제목/요약/키워드: strength and stability

검색결과 2,456건 처리시간 0.029초

오토클레이브 양생에 따른 콘크리트 마감재의 표면특성에 관한 연구 (The Study on the Surface Properties of Concrete Tile According to the Autoclave Curing)

  • 최선미;정지용;정은혜;곽은구;김진만
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
    • /
    • pp.77-80
    • /
    • 2005
  • The surface of concrete tiles is weak in moisture that it occurrenced efflorescence, but in the former study we found that it is possible to ensure moisture stability of concrete surface by autoclaving. So this study is to discuss the moisture stability and Physical Properties of high-strength glossy concrete according to time and temperature of autoclave curing. As the results, by increasing time and temperature of autoclave curing, compressive strength and surface hardness increased and glossiness decreased. In the case to 3 hour and $180^{\circ}C$ of autoclave curing, there is not effloescences in mosture stability test.

  • PDF

Effects of Agility Training with Kinesio Taping on Muscle Tone, Muscle Strength Lower Extremity and Dynamic Stability in Women Softball Players

  • Kim, Kyunghun;Kim, Hyeonhee
    • Physical Therapy Rehabilitation Science
    • /
    • 제10권4호
    • /
    • pp.479-486
    • /
    • 2021
  • Objective: The aim of this study was to investigate the effect of agility training with kinesio taping (ATKT) on muscle tone, muscle strength lower extremity and dynamic stability of women softball players. Design: Two groups pre-post randomized controlled design Methods: 34 softball players were recruited randomly assigned into the ATKT group and agility training with sham kinesio taping (control group). All subjects performed agility training for 30 min/day, 5 times/week for 4 weeks. The subjects in the ATKT group underwent agility trainingwith kinesio taping on vastus madialis, vastus medialis, rectus femoris, and vastus lateralis where the subects in the control group underwent agility trainingwith sham kinseio taping. Muscle tone was measured using myotonPRO. A Hand dynamometer was used to evaluate muscle strengthening of lower -extremity. Dynamic stability was measured using the side hop test. Results: Muscle tone of lower-extremity was significantly more increased in the ATKT group (mean change 0.39 ± 0.31) than in the control group (mean change 0.19 ± 0.31) (p<0.05). Muscle strength of lower-extremity was significantly more increased in the ATKT group than in the control group (p<0.05). Dynamic stability was significantly more increased in the ATKT group (mean change -1.39 ±0.45) than in the control group (mean change -0.60 ± 0.46) (p<0.05). Conclusions: We confirmed that the benefits that ATKT is effective for increasing in softball players and suggested that knee joint kinesio taping. Also, it was observed improvement of muscle tone, muscle strength and Dynamic stability.

강도 및 건조수축 저감을 통한 CLC의 안정성 평가 (Evaluation of Stability of CLC through Strength and Reduction of Drying Shrinkage)

  • 이창우;황우준;이상수
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2022년도 가을 학술논문 발표대회
    • /
    • pp.205-206
    • /
    • 2022
  • This study intends to conduct tests on subsidence and drying shrinkage by mixing CaO-CSA expansion materials to ensure the stability of CLC, and to understand its properties. Based on CLC of 0.6, the replacement ratio of CaO-CSA expansion material was conducted at five levels compared to blast furnace slag, and the results are as follows. The replacement of CaO-CSA expansion material at an appropriate level produces ethringhite and potassium hydroxide, and it is believed that the internal voids of CLC and the Tobelmorite interlayer structure are charged to increase the structural stability, leading to an increase in compressive strength and a decrease in the drying shrinkage. However, it is judged that tissue relaxation due to excessive substances in the high replacement ratio affects the stability of CLC. In the future, we will conduct additional experiments on density, absorption rate, flow test, and settlement, and evaluate and analyze the stability of CLC by selecting the optimal replacement ratio of CaO-CSA expansion materials.

  • PDF

The effect of the thread depth on the mechanical properties of the dental implant

  • Lee, Sun-Young;Kim, Sung-Jun;An, Hyun-Wook;Kim, Hyun-Seung;Ha, Dong-Guk;Ryo, Kyung-Ho;Park, Kwang-Bum
    • The Journal of Advanced Prosthodontics
    • /
    • 제7권2호
    • /
    • pp.115-121
    • /
    • 2015
  • PURPOSE. This study aimed to evaluate the effect of implant thread depth on primary stability in low density bone. MATERIALS AND METHODS. The insertion torque was measured by inserting Ti implants with different thread depths into solid rigid polyurethane blocks (Sawbones) with three different bone densities ($0.16g/cm^3$, $0.24g/cm^3$, and $0.32g/cm^3$). The insertion torque value was evaluated with a surgical engine. The static compressive strength was measured with a universal testing machine (UTM) and the Ti implants were aligned at $30^{\circ}$ against the loading direction of the UTM. After the static compressive strength test, the Ti implants were analyzed with a Measurescope. RESULTS. The Ti implants with deeper thread depth showed statistically higher mean insertion torque values (P<.001). Groups A and group B had similar maximum static compressive strengths, as did groups C and D (P>.05). After the static compressive strength, the thread shape of the Ti implants with deeper thread depth did not show any breakage but did show deformation of the implant body and abutment. CONCLUSION. The implants with deeper thread depth had higher mean insertion torque values but not lower compressive strength. The deep threads had a mechanical stability. Implants with deeper thread depth may increase the primary stability in areas of poor quality bone without decreasing mechanical strength.

사면 안정해석에 적용되는 지반강도정수($C, _{\Phi}$)와 사면경사 민감도 분석 (Sensitivity Analysis of Shear Strength Parameters($C, _{\Phi}$)and Slope Angel in Slope Stability Analysis)

  • 백용;배규진;권오일;장수호;구호본
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
    • /
    • pp.179-184
    • /
    • 2005
  • Shear strength parameters obtained from filed survey are important factors in the analysis of slope stability. In this study, sensitivity analysis was performed to evaluate the effect of input parameters on the analysis of slope stability. The input parameters selected for sensitivity analysis were slope angle, cohesion, and friction angle. Monte-Carlo Simulation method was used for calculating input parameters and the factor of safety was computed by means of limit equilibrium method. A rock slope, which has failed in the field, was used for the sensitivity analysis in the analysis of slope stability. The result of analysis shows that the factor of safety of the rock slope was a little low. From partial correlation coefficient(PPC) of input parameters determined from the sensitivity analysis, slope stability was dependant on cohesion and slope angle. The effect of friction angle was lower than that of cohesion and slope angle on slope stability.

  • PDF

교각운동이 월경곤란증으로 인한 허리통증을 가진 여대생에게 미치는 영향 (The Effect of Bridging Exercise on Dysmenorrhea Back Pain of Women University Students)

  • 정연우;홍상현;이승협
    • 대한통합의학회지
    • /
    • 제4권4호
    • /
    • pp.1-6
    • /
    • 2016
  • Purpose : This study determines the effect and sustainability of the trunk stability exercise program, specifically using the bridge exercise, by measuring Visual Analogue Scale(VAS), Menstrual Distress Questionaire(MDQ) and muscle strength in women university students complaining of low back pain. Methods : The trunk stability exercise program was progressed by 22 women university students, for 4 weeks, (3 times a week, 1 hour per session). At this time, low back pain happened at the period of menstruation and was measured using VAS, Dysmenorrhea using the MDQ tool and abdominal and back muscle strength using HUR. This study was evaluated 4 times (before and after the exercise program, after 4 weeks and 8 weeks) to investigate the effect of time variation after the exercise program. Results : The trends showed a decrease in VAS and MDQ and an increase in abdominal and back muscle strength. Therefore, these results were evaluated positively from a statistical perspective(p<.05). Conclusions : The trunk stability exercise results in a decreased VAS and MDQ, and increases the muscle strength in women university students who complained of low back pain form dysmenorrhea. Therefore, the low back pain from dysmenorrhea could have been avoided and quality of everyday life improved.

종이 기록물 보수용 안전 테이프 시제품 제조 기술 연구 (Manufacture Technology Development of Paper Mending Tape for Conservation of Archive Document)

  • 신종순;유선균
    • 한국인쇄학회지
    • /
    • 제29권3호
    • /
    • pp.41-53
    • /
    • 2011
  • For manufacturing the tape for repairing archival documents, we tested ten carrier candidates for selecting best material. The tensile strength, transmissivity, stability of deterioration, and processability were determined. Physical-chemical characteristics and stability of deterioration was best to the Hanji. Tensile strength and transmissivity was best in tracing paper, but was low in oil paper, white sketch paper, lyon coat paper. Synthetic carrier to tensile strength showed higher than paper carrier and to the transmissivity showed 2-8 times higher than paper carriers. The tracing paper to the transmissivity was 10 times higher than others. To determine characteristic of conservation to the selected carriers, stability of deterioration was examined at conditions of $90^{\circ}C$ for 15 days. Oil paper and white sketch paper turned strongly yellowish. Cellulopane, Felt, and Cpp film showed stable stability of deterioration, but deformation like wrinkles. PET film and Syntheletic film showed excellent conservation characteristics without any change of exterior. Test of adhesive uniform between carriers and adhesive processability was performed. PET film > Syntheletic film > Tracing Paper in order were determined. Ununiformal adhesive characteristics appeared to Hangi. Accordingly, we thought that Hanji as carrier material might be unsuitable because of low adhesive processability.

Sport impact on the strength of the nanoscale protein tissues under the thermal condition

  • Xin, Fang;Mengqian, Hou
    • Advances in nano research
    • /
    • 제13권6호
    • /
    • pp.561-574
    • /
    • 2022
  • The stability of protein tissues and protein fibers in the human muscle is investigated in the presented paper. The protein fibers are modeled via tube structures embedded in others proteins fibers like the elastic substrate. Physical sport and physical exercise play an important role in the stability of synthesis and strength of the protein tissues. In physical exercise, the temperature of the body increases, and this temperature change impacts the stability of the protein tissues, which is the aim of the current study. The mathematical simulation of the protein tissues is done based on the mechanical sciences, and the protein fibers are modeled via wire structures according to the high-order theory beams. The thermal stress due to the conditions of the sport is applied to the nanoscale protein fibers, then the stability regarding the frequency analysis is investigated. Finally, the impact of temperature change, physical exercise, and small-scale parameters on the stability of the protein tissues are examined in detail.

Reliability analysis on fatigue Strength for Certification of Aircraft Composite Structures

  • Choi, Cheong Ho;Lee, Doo Jin;Jo, Jae Hyun;Bae, Sung Hwan;Lee, Myung Jik;Lee, Jong Ho
    • 항공우주시스템공학회지
    • /
    • 제15권2호
    • /
    • pp.16-25
    • /
    • 2021
  • Reliability of fatigue strength on Aircraft Composites(GFRP) Structures was assessed in this paper. Fatigue strength of GFRP was used through the existing fatigue test data with Monte Carlo method. The Sa-Nf curve of composites fatigue strength was assumed as normal distribution and reliability was analyzed using SSIT model. Fatigue stress was designed IAW ASTM F3114-15 with special safety factor of Ssf=1.2~2.0. Reliability was calculated by analytic method and FORM. Sensitivity for the effect of mean and standard deviation of fatigue strength as well as fatigue stability was evaluated. This result can be usefully applied to reliability and fatigue design for composite structures of light weight aircraft.

Stability analysis of homogeneous slopes with benches

  • Zhao, Lianheng;Xia, Peng;Xie, Rongfu;Li, Liang;Zhang, Yingbin;Cheng, Xiao
    • Geomechanics and Engineering
    • /
    • 제13권3호
    • /
    • pp.517-533
    • /
    • 2017
  • In this paper, with a graphical approach, a series of stability charts for homogeneous slopes with benches are presented based on the upper bound limit analysis theory and strength reduction technique. The objective function of the slope safety factor $F_s$ is optimized by the nonlinear sequential quadratic programming, and a substantial number of examples are illustrated to use the stability charts for homogeneous slopes with benches driven by only the action of the soil weight. These charts can be applied to quick and accurate estimations of the stability status of homogeneous slopes with benches. Moreover, the failure modes and the formula for safety factor Fs of homogeneous slopes with benches are provided to illustrate the stability analysis of slopes with benches, which is validated by samples.