• Title/Summary/Keyword: Test procedures

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Impact conditions of motorcyclists on road protection systems by numerical simulation

  • Peng, Li;Brizard, Denis;Massenzio, Michel
    • Structural Engineering and Mechanics
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    • v.82 no.2
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    • pp.233-244
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    • 2022
  • Following a loss of control, the impact against a road barrier in a turn predominates among the most severe motorcyclist accidents. These road restraint devices can be equipped with a motorcycle screen, the function of which is to restrain the rider and minimize the consequences of the impact in terms of the severity of injuries. The performance of these screens is evaluated by the European normative procedure EN1317-8, which specifies the test conditions, based on one or two configurations. In practice, however, these impact conditions are very diverse, difficult to extrapolate from accident analysis and therefore poorly investigated. This study is interested in improving knowledge of these impact conditions in terms of impact speed, impact angle and particularly position of the rider. A finite element model has been developed to simulate the dynamic behavior of the rider from loss of control to impact on the screen. Statistical analysis of the results shows a high variability of the impact conditions, in particular with regard to the direction of turn (to the right or to the left). Some improvements are suggested in order to overcome the limitations inherent in standard procedures.

State Management of Transfer Pricing Activities of Foreign-Invested Enterprises in Vietnam

  • LE, Ha Thanh;PHAN, Nam Tien
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.2
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    • pp.133-140
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    • 2022
  • The impact of State management factors on transfer pricing activities of foreign direct investment enterprises in Vietnam is examined in this study. This adds to the empirical evidence on factors affecting transfer pricing activities of foreign-invested enterprises in Vietnam. A questionnaire survey of officials directly involved in the inspection of transfer pricing activities is used as the research method. The study yielded 226 questionnaires. The author chose 210 questionnaires after deleting those that were ineligible due to a large number of blank cells. The following procedures are used to process the data from the satisfied votes: Cronbach's Alpha test to measure the reliability of the scale; Exploratory factor analysis to break down data into smaller sets of variables to discover the underlying structure; Descriptive analysis to describe the underlying quantitative features of the data; Correlation and regression analysis to evaluate the relationship between variables with the support of SPSS 25 software. Inspection pressure, professional inspector qualifications, and inspector role, State control organization, inspector professionalism, legal corridor on transfer pricing control, macroeconomic situation, and investment environment have a positive impact on state management on transfer price operations, according to research findings. The author has provided solutions to increase the efficiency of State management on transfer pricing operations of foreign-invested businesses in Vietnam based on the research findings.

Disinfection of various materials with 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride in hatchery facilities

  • Kim, Yu-Jin;Kim, Jun-Beom;Song, Chang-Seon;Nahm, Sang-Soep
    • Animal Bioscience
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    • v.35 no.4
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    • pp.631-637
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    • 2022
  • Objective: Surface disinfection is important in the proper running of livestock farms. However, disinfection of farm equipment and facilities is difficult because they are made of different materials, besides having large surface areas and complex structures. 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (Si-QAC) is a quaternary ammonium salt-based disinfectant that attaches to various surfaces by forming covalent bonds and maintains its disinfecting capacity for a considerable time. Our aim was to evaluate the potential use of Si-QAC for disinfection of farm equipment and facilities. Methods: The short- and long-term antimicrobial and antiviral effects of Si-QAC were evaluated in both laboratory and farm settings using modified quantitative assessment method based on the standard operating procedures of the United States Environmental Protection Agency. Results: Si-QAC was highly effective in controlling the growth of the Newcastle disease virus and avian pathogenic Escherichia coli. Electron microscopy revealed that the mechanism underlying the disinfection activity of Si-QAC was associated with its ability to damage the outer membrane of the pathogen cells. In the field test, Si-QAC effectively reduced viral contamination of surfaces of equipment and space. Conclusion: Our results suggest that Si-QAC has great potential as an effective chemical for disinfecting farm equipment and facilities. This disinfectant could retain its disinfection ability longer than other commercial disinfectants and contribute to better farm biosecurity.

Strengthening of T-beams using external steel clamps and anchored steel plates

  • Yunus Dere;Yasin Onuralp Ozkilic;Ali Serdar Ecemis;Hasan Husnu Korkmaz
    • Steel and Composite Structures
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    • v.48 no.4
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    • pp.405-417
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    • 2023
  • In order to strengthen the reinforced concrete T-beams having insufficient shear strength, several strengthening techniques are available in the literature. In this study, three different strengthening strategies were numerically studied. First one is affixing steel plates to the beam surfaces. Second one includes tightening external steel bars vertically similar to beam stirrups. The last one is simultaneous application of these two strengthening procedures which is particularly proposed in this work. Available experimental test series in the literature were handled in the study. Finite element (FE) models of reinforced concrete beam specimens having sufficient (Beam-1) and low shear capacity (Beam-2) were created within ABAQUS environment. Strengthened beams with different techniques were also modelled to reflect improved shear capacity. FE simulations made it possible to investigate parameters that were not examined during the previous experimental studies. The results of the analyses were then compared and found consistent with the experimentally obtained data. Experimental and FEM analysis results are in agreement between 1% (closest) and 6%. (maximum). Beam-2 was stregthened with 5 new porposed methods. The rate of increase in shear strength varies between 33% and 64%. It was found that, the strengthening techniques were fairly useful in improving the shear capacity of the considered girder. The model with the proposed strengthening alternative has accomplished a higher load carrying capacity, ductility and stiffness than all of the other models.

Variation of Operating Clearance Depending on Cooling Methods of High-Speed Roller Bearings for Aerospace Applications (항공용 고속 롤러베어링의 냉각 방식에 따른 작동간극 변화)

  • Jisu Park
    • Tribology and Lubricants
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    • v.39 no.4
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    • pp.123-132
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    • 2023
  • In this study, the expansion, stress, and operating clearance of bearing elements during operation are observed using the inner/outer ring temperature test data of a 3.0×106 DN-class roller bearing. The operating clearance characteristics of inner-/outer-ring cooling (IORC) bearings are compared to those of inner-ring cooling (IRC) bearings. For IRC bearings, the thermal expansion of the outer ring is the most important factor in clearance variation. As a result, the operating clearance is less than the initial clearance of 61 ㎛, and the operating clearance decreases to 0.5 ㎛ at 25,500 rpm. Conversely, the temperature of the outer ring of IORC bearings is lower than that of IRC bearings, so the operating clearance is kept smaller. When the coolant flow rate to the outer ring is approximately 1.5 to 2.0 L/min, the temperature difference between the inner and outer rings is minimized and the operating clearance is maintained at a significantly lower level than IRC bearings. Small operating clearances are expected to be effective in reducing cage slip and skid damage in roller bearings. The results and analysis procedures of this study can be utilized to design of bearing clearance, lubricant flow rate, and assembled interference in the early design stage of aerospace roller bearings.

Cyclic behavior of jumbo reduced beam section connections with heavy sections: Numerical investigation

  • Qi, Liangjie;Liu, Mengda;Shen, Zhangpeng;Liu, Hang
    • Earthquakes and Structures
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    • v.23 no.2
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    • pp.183-196
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    • 2022
  • Reduced beam section (RBS) moment connections used in special moment resisting frames are currently limited to beam sections that are not larger than nominal depths of 920 mm, weight of 447 kg/m and flange thickness of 44 mm. Due to the higher demand for structural components with jumbo sections, which can potentially be applied in the transfer girders in long-span building structures, the newly available steel heavy members are promising. To address this issue, advanced numerical models are developed to fully evaluate the distribution of stresses and concentrations of plastic strains for such jumbo RBS connections. This paper first presents a brief overview of an experimental study on four specimens with large beam and column sections. Then, a numerical model that includes initial imperfections, residual stresses, geometric nonlinearity, and explicitly modeled welds is presented. The model is used to further explore the behavior of the test specimens, including distribution of stresses, distribution of plastic strains, stress triaxiality and potential for fracture. The results reveal that the stresses are highly non-uniform across the beam flange and, similarly, the plastic strains concentrate at the extreme fiber of the bottom flange. However, neither of these phenomena, which are primarily a function of beam flange thickness, is reflected in current design procedures.

Experimental investigation of the effect of the addition of Aerosil 200 nanoparticles on the water absorption of polymer concrete

  • A.M. Fattahi;Babak Safaei;Elham Moaddab;Zahra Pezeshki
    • Advances in nano research
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    • v.14 no.1
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    • pp.81-92
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    • 2023
  • In this work, the effect of the addition of Aerosil 200, an insulating resin applied in many industries, on the water absorption of cement plast mixture has been experimentally evaluated. First, the preparation stages of cement plast mixture was evaluated based on corresponding standards and then, the effect of the addition of Aerosil 200 nanoparticles (NPs) to cement plast mixtures with sand weight percentage range of 0-0.1% on the variation of water absorption properties was evaluated based on National Standard Institution of Iran 20185 for Concrete Flooring Blocks - Requirements and Test Procedures. Based on the obtained results, it could be found that excessive addition of NPs did not affect the physical properties of the final product. Water absorption percentage was increased in the weight percentage of cement. By the increase of the amount of Aerosil 200 NPs in the prepared cement plast mixture, the percentage of water absorption in weight percentage of sand was decreased. Cement plast with NPs presented significantly lower water absorption than that without NPs.

Evaluation of Shear Load-transfer Barrette Pile in Sandy Soils (사질지반에서의 바렛말뚝의 주면하중전이 거동 평가)

  • Lee, Sang-Rae;Park, Seong-Wan;Lim, Dae-Sung
    • Journal of the Korean Geotechnical Society
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    • v.26 no.9
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    • pp.5-13
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    • 2010
  • Recently, the use of barrette pile has remarkably increased for high-rise building and bridge foundations. However, relatively few studies have been made for analyzing barrette pile behavior by considering shear load transfer on interface between pile and soils. Therefore, in this paper, an empirically derived equation is proposed. This equation correlates the load transfer curve of barrette piles with the N value from field standard penetration test based on full-scale load tests. The results from all procedures are presented. In addition, the effect of interface on pile-soil is evaluated using 3-D non-linear finite element method and verified with the field data.

Development and Standardization of Dried Persimmons Gruel on Books (고문헌을 바탕으로 한 건시죽(乾粥)의 개발과 표준화)

  • Cho, Mi-Sook;Lee, Eun-Young;Kim, Jan-Di
    • Journal of the Korean Society of Food Culture
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    • v.23 no.1
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    • pp.115-120
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    • 2008
  • The dried persimmon was effective in caring an inflammation, an ulcer and a burn and preventing hypertension and arteriosclerosis. At the Jejungsinpyun. dried persimmons gruel was beneficial to stomach and intestine and toned down voice. Based on Jejungsinpyuns and Sikryochanyo, dried persimmons gruel was developed for modern people. To standardize the dried persimmons gruel, physical properties and consumer acceptability was examined. The procedures of dried persimmons gruel was to make dried persimmons juice after soaking dried persimmons with same volume water during 24 hr and blending. To decrease the astringent taste of dried persimmons, dried persimmons juice and water with cinnamon (2%) was mixed and simmered during 3 min. Dried persimmons paste with cinnamon was added and the gruel was boiled more during 5 min. dried persimmons gruel was completed. The dried persimmons gruel were divided of 5 groups consisted of each 10, 15, 20, 25, 30 g dried persimmons. As dried persimmons content increased, lightness, apparent viscosity decreased. Acceptability test indicated the sample of dried persimmons : rice ratio at 2 : 5 had the highest overall acceptability and flavor. Considered to each, the sample of the dried persimmons : rice ratio at 2 : 5 met the purpose of the study.

A Study on the Development of a MOOC Design Model

  • LEE, Gayoung;KEUM, Sunyoung;KIM, Myungsun;CHOI, Yoomi;RHA, Ilju
    • Educational Technology International
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    • v.17 no.1
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    • pp.1-37
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    • 2016
  • The purpose of this study was to develop a MOOC design model that would improve the current practice of MOOC development in Korea by specifying easy-to-use course development procedures and guiding strategies. Following Richey and Klein (2007)'s conceptual model development procedure, the first step was to perform critical review of relevant literature and observe typical MOOC development processes. As a result, the initial model was developed. The second step was to conduct the expert review with five educational technology and MOOC researchers to secure the internal validity of the model. Based on the experts' suggestions, the model was revised and once again reviewed by the same experts. This process resulted in the development of the 2nd version of model. The third step was to carry out external validation research in order to test the effectiveness, efficiency, and usability of the model. A basic model may be confirmed or corrected based on examination of its results. Consequently, the model was elaborated as the final model. In the final model, 6 procedural phases and 9 specific steps were included. The six procedural phases are: Analysis (1st Iteration), Design, Development (Course Development), Implementation, Evaluation, and Analysis (2nd Iteration), a slight variation of ADDIE model. The specific steps include: 1) Goal Setting, 2) Environment Analysis, 3) Content Design, 4) Style Design, 5) Course Development, 6) Implementation Plan, 7) Course Implementation, 8) Summative Evaluation, and 9) Need Reflection. The study concluded with suggestions for further research and application of the MOOC design model.