• Title/Summary/Keyword: strength class

Search Result 491, Processing Time 0.03 seconds

The Thatcher's 'Welfare Reforms' and the Changed Balance of Class Strength (대처의 '복지개혁'과 계급관계)

  • Won, Seok-Jo
    • Korean Journal of Social Welfare
    • /
    • v.44
    • /
    • pp.232-261
    • /
    • 2001
  • Because of their international importance, 'the Welfare Reforms' of the Thatcher government as well as Thatcherism were studied so much, and analysed so deeply. However, the existing studies mainly focused the institutional changes of the welfare state themselves and cynically criticized the decline of it. And, there is no study explained the Thatcher's reform as the changed balance of the British class strength. This means that the nature of the Thatcher's welfare reform is not scientifically clarified yet. So, I tried to examine this one again. For the purpose, I reviewed the nature of Thatcherism, described the changed welfare state, and analysed the result of the polling, the power dynamics of the Labour Party, the changed attitude of the Labour Party and the working class to the welfare state and Keynesianism, and the political attack of the Thatcher government on the working class and their response to it.

  • PDF

Structural Characteristics on the Buckling Strength for 600MPa Grade High Strength Steel Compression Members (600MPa급 고강도강 압축재의 좌굴강도에 관한 구조특성)

  • Lee, Myung-Jae
    • Journal of Korean Society of Steel Construction
    • /
    • v.22 no.6
    • /
    • pp.609-616
    • /
    • 2010
  • The objective of this study is to investigate the structural character of the buckling strength of 600MPa-class high-strength steel compression members. The buckling strength of circular hollow-section columns is evaluated by a numerical analysis of the stress-strain curves of the tension test results. The numerical analysis was based on the beam-column theory and the tangent modulus theory. It was considered possible to enlarge the nominal yield strength of the 600MPa-class steel.

A Comparison of Physical Fitness of High School Ssirum Elite-players According to Their Weight Class (고등부 씨름선수의 체급별 기초·전문체력 비교분석)

  • Jung, Joo-Ha;Kim, Sung-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.12
    • /
    • pp.162-169
    • /
    • 2020
  • This study was conducted from November 25 to December 4, 2019, to unmask differences in physical fitness based on the weight class of high school Ssirum elite-players. A total of 28 high school Ssirum elite-players were compared and analyzed by measuring physical factors (muscle strength/power, agility, anaerobic power, aerobic ability, flexibility, and isokinetic muscle function) by weight class. Data were analyzed using SPSS ver. 23.0. One-way ANOVA was used for comparison between groups. There was no difference by weight class in terms of grip strength, sit-ups, sergeant jump, long jump, flexibility, side step, and reaction time. Evaluation of back muscle strength revealed that the group with more than 100 kg had greater strength than lower weight categories, whereas it was lower in the sit-ups, 20 m shuttle run and the relative values anaerobic power. Considering isokinetic muscle function, no difference was observed between the groups of back muscle strength and knee joint. The results of this study indicate that amongst the high school Ssirum elite-players, there is no difference in muscle power, flexibility, agility, and anaerobic average power per body weight, isokinetic trunk strength, and knee flexion strength, when evaluated according to weight class.

Improving Quality of Fly ash Replace Concrete by Second-Class Blast Furnace Slag Powder and Gypsum (고로슬래그 미분말 2종 및 석고에 의한 플라이애시 치환 콘크리트의 품질 향상)

  • Jeon, Kyu-Nam;Lee, Jeong-Ah;Choi, Sung-Yong;Baek, Dae-Hyun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2009.05b
    • /
    • pp.97-100
    • /
    • 2009
  • This study is a basic experiment to complement the problems in decrease of strength in case we change lots of fly ash("FA" here in after) in ordinary portland cement("OPC" here in after). Mixing plaster that is known to be effective in improvement in hydration of blast furnace slag powder("BS" here in after). After FA changed concrete is mixed, the study physical proporties such as compression strength, increased proportionaly. When second-class BS 5 % and gypsum 2 % changed, compare to OPC strength approximately 120 % was recorded after one day. In FA 20 % case, according to the ratio of gypsum changed results showed similar trend, but compared to FA 10 % changed concrete, expression strength improvement was lower.

  • PDF

Aspects of size effect on discrete element modeling of normal strength concrete

  • Gyurko, Zoltan;Nemes, Rita
    • Computers and Concrete
    • /
    • v.28 no.5
    • /
    • pp.521-532
    • /
    • 2021
  • Present paper focuses on the modeling of size effect on the compressive strength of normal concrete with the application of Discrete Element Method (DEM). Test specimens with different size and shape were cast and uniaxial compressive strength test was performed on each sample. Five different concrete mixes were used, all belonging to a different normal strength concrete class (C20/25, C30/37, C35/45, C45/55, and C50/60). The numerical simulations were carried out by using the PFC 5 software, which applies rigid spheres and contacts between them to model the material. DEM modeling of size effect could be advantageous because the development of micro-cracks in the material can be observed and the failure mode can be visualized. The series of experiments were repeated with the model after calibration. The relationship of the parallel bond strength of the contacts and the laboratory compressive strength test was analyzed by aiming to determine a relation between the compressive strength and the bond strength of different sized models. An equation was derived based on Bazant's size effect law to estimate the parallel bond strength of differently sized specimens. The parameters of the equation were optimized based on measurement data using nonlinear least-squares method with SSE (sum of squared errors) objective function. The laboratory test results showed a good agreement with the literature data (compressive strength is decreasing with the increase of the size of the specimen regardless of the shape). The derived estimation models showed strong correlation with the measurement data. The results indicated that the size effect is stronger on concretes with lower strength class due to the higher level of inhomogeneity of the material. It was observed that size effect is more significant on cube specimens than on cylinder samples, which can be caused by the side ratios of the specimens and the size of the purely compressed zone. A limit value for the minimum size of DE model for cubes and cylinder was determined, above which the size effect on compressive strength can be neglected within the investigated size range. The relationship of model size (particle number) and computational time was analyzed and a method to decrease the computational time (number of iterations) of material genesis is proposed.

Mechanical characteristics of class-F groundwall insulation tapes for stator windings (고정자 권선용 F종 주절연테이프의 기계적 특성)

  • Kim, Tae-Hee;Kang, Myung-Guk;Lee, Jai-Kwun;Son, Sam-Young
    • Proceedings of the KIEE Conference
    • /
    • 2004.07c
    • /
    • pp.1676-1678
    • /
    • 2004
  • Class-F resin-rich type insulating tapes are generally used for the groundwall insulations of the large turbine generators with air-cooled and hydrogen-cooled stator windings. In this paper, mechanical strength properties degraded over aging time in higher temperature than designed one in normal condition were experimentally investigated and the results of comparative tests were presented on the existing class-F resin-rich type tape and a developed one after curing. The resin-rich insulating tapes with composite material of Mica/Epoxy/support currently were used in this test. The tests for tensile and flexural strength properties were conducted with the specimens which were composed of unaged and the aged specimens accelerated for one, two, and three thousand hours at 180 $^{\circ}C$. The tensional strength was only measured for the unaged specimens and the results are also presented to make a comparative test for their initial mechanical characteristics.

  • PDF

A Study on activation way of vocational education training for construction skill manpower problems solution (건설기능인력난 해결을 위한 직업교육훈련의 활성화 방안에 관한 연구)

  • Lee, Seung-Jae;Oh, Sangl-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2006.11a
    • /
    • pp.133-137
    • /
    • 2006
  • Can examine cause that the construction industry is faced in crisis of skill exhaustion in two sides. One is the tribe of actuality production manpower by entry evasion and graying of young man class specially new manpower to the tribe of skill manpower. Another is qualitative decline of skill manpower. Generally, problem of the systematic knowledge tribe and the picking up tribe about new technology etc, exists because learn skill for shoulder beyond in spot. In cutting phenomenon of skill that is depended on personal relationships availability with skilled worker in hereafter, problem that worker who is old or enter through rain skilled worker does not learn all life skill is detected. These problems institute entry of young man class and necessity of systematic vocational education training specially new human strength strongly. This study does presentation of way to promote construction industry entry of young man class and improvement way of vocational education training system that can do to train these by function manpower by purpose.

  • PDF

An Evaluation on the Chloride Resistance of Concrete Footing at Coastal Area -Comparision of Performance in Korea Building Code(KBC)- (해안인접지역 기초 구조물콘크리트의 내염해 성능 평가 -건축구조기준과의 성능비교-)

  • Park, Yong-Kyu;Yoon, Gi-Won;Kim, Hyun-Woo;Kim, Yong-Ro;Song, Young-Chan
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2016.10a
    • /
    • pp.148-149
    • /
    • 2016
  • In this paper, the increase in chloride resistance of footing concrete at coastal area was evaluated by replacement of Mineral Admixture. In KBC 2009, the footing concrete's minimum specific concrete strength at coastal area is determined to 35MPa. However, this is criteria only based on the strength aspect. Thus, it is not considered to increase the chloride resistance by replacement of Mineral Admixture. According to the test results of chloride ions penetration resistance, 35MPa class concrete with OPC 100% shown inaccessible state. Low-strength (24~30MPa class) concretes with Mineral Admixture, however, presented better performances. In addition, chloride diffusion coefficient tests showed identical appearance. Therefore, the current KBC's chloride resistance criteria based on only concrete strength has to review for the reason it can cause many problems (ex. cost increases by growing concrete strength and the environmental issues by a lot of cement use).

  • PDF

Evaluation of Characteristics of G-class Cement for Geothermal Well Cementing (지열 발전정 시멘팅을 위한 G-class 시멘트 특성 평가에 관한 연구)

  • Won, Jongmuk;Jeon, Jongug;Park, Sangwoo;Choi, Hangseok
    • Journal of the Korean Geotechnical Society
    • /
    • v.29 no.5
    • /
    • pp.29-38
    • /
    • 2013
  • The G-class cement is commonly used in practice for geothermal well cementing in order to protect a steel casing that is designed to transport hot water/steam from deep subsurface to ground surface during operating a geothermal power plant. In order to maintain optimal performance of geothermal wells, physical properties of the cementing material should be satisfactory. In this paper, relevant factors (i.e., groutability, uniaxial compression strength, thermal conductivity and free fluid content) of the G-class cement were experimentally examined with consideration of various water-cement (w/c) ratios. Important findings through the experiments herein are as follows. (1) Groutability of the G-class cement increases by adding a small dose of retarder. (2) There would be a structural defect caused when the w/c ratio is kept higher in order to secure groutability. (3) Thermal conductivity of the G-class cement is small enough to prevent heat loss from hot steam or water to the outer ground formation during generating electricity. (4) The G-class cement does not form free water channel in cementing a geothermal well. (5) The Phenolphthalein indicator is applicable to the distinction of the G-class cement from the drilling mud.

A Study on Influence of a College Student's Participation Motivation before/after Ski Class on Class Satisfaction & Revisit (대학생들의 스키수업 참여 전·후 참여동기가 수업만족 및 재방문에 미치는 영향)

  • LEE, Tea-Ung
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.28 no.6
    • /
    • pp.1882-1893
    • /
    • 2016
  • This study intended to look into the causal relations, in which a ski class conducted at a college is linked from college students' participation motivation to satisfaction and revisit. Among others, this study intended to boost the quality of the ski class conducted at a college with focus on the difference between the influences on satisfaction and revisit according to pre/post class participation. Further, the purpose of this study is to inquire into an ultimate basic plan required for winter sports development on the basis of the deduced results, through which this study drew the conclusion as follows: First, it was found that the influence relationship between class satisfaction before/after class was established in a joy seeking factor according to ski class participation motivation. Second, the daily routine deviation factor among the sub-factors of ski class participation motivation was found to have a positive effect on revisit before/after class while friendship promotion factor, health factor and physical strength factor were found to have an influence on revisit after class.