• Title/Summary/Keyword: Model Experimental Research

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Flexural fatigue modeling of short fibers/epoxy composites

  • Shokrieh, M.M.;Haghighatkhah, A.R.;Esmkhani, M.
    • Structural Engineering and Mechanics
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    • v.64 no.3
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    • pp.287-292
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    • 2017
  • In the present research, an available flexural stiffness degradation model was modified and a new comprehensive model called "X-NFSD" was developed. The X-NFSD model is capable of predicting the flexural stiffness degradation of composite specimen at different states of stresses and at room temperature. The model was verified by means of different experimental data for chopped strand mat/epoxy composites under displacement controlled bending loading condition at different displacements and states of stresses. The obtained results provided by the present model are impressively in very good agreement with the experimental data and the mean value of error of 5.4% was achieved.

A study on a present condition of research on the experimental model in oriental medicine (실험동물의 병증(病證) 모형에 대한 연구현황 소고 - 중의(中醫) 자료를 중심으로 -)

  • Choi, Sun-Mi
    • Korean Journal of Oriental Medicine
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    • v.1 no.1
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    • pp.69-99
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    • 1995
  • In order to develop experimental research in oriental medicine, it is necessary to make experimental model of diagnostic pattern(證), On model of the condition of a disease maked in china, there are cold-pattern(寒證), heat-pattern(熱證), deficiency of vital energy-pattern(氣虛證), blood-deficiency-pattern(血虛證), yin-deficiency-pattern(陰虛證), yang-deficiency-pattern(陽虛證), deficiency of both yin and yang-pattern(陰陽俱虛證), yang-exhaustion-pattern(亡陽證), blood stasis-pattern(血瘀證), pattern of defferential diagnosis according to states of viscera(臟腑辨證).

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Effectiveness of using Cognitive Virtual Tours based on Marzano Model to Develop the Achievement and Historical Research Skills for Secondary School Students

  • Abdalla, Atef Mohamed Saied
    • International Journal of Computer Science & Network Security
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    • v.22 no.8
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    • pp.292-298
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    • 2022
  • The study aimed to measure the effectiveness of using Cognitive virtual tours based on Marzano model to develop the achievement and some of historical research Skills for secondary school students. To achieve the objectives of the study, the experimental method was used and two study groups consisted of (60) students were divided into two groups, one is Control (30) students and the other is in experimental (30) students at Alsalam secondary in Ismailia Governorate. The study used several tools: The experimental processing tool of Cognitive Virtual tours based on Marzano model, Cognitive achievement test for the first unit of Secondary first grade history Course. Historical research skills. The finding of the study showed the effectiveness of using cognitive virtual tours based on Marzano model in developing the achievement and some of historical research skills for first grade secondary students which there are Statistically differences at level (0.01) between the average scores of the students in (experimental and Control) groups in post application for Cognitive achievement test. Practical application of the study can contribute to clarify how to use Cognitive virtual tours based on Marzano model in teaching history, and Draw the attention of history developers to the development of historical research skills.

Development of a Model for the Analysis of Occupant Response subjects in Low-Speed Rear-End Collision (저속 후방 추돌에 따른 승객 거동 현상 해석용 모델 개발)

  • 김희석;김영은
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.3
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    • pp.139-150
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    • 2000
  • Although a number of neck injuries are generated, the data which quantify the kinematic response of the human head and cervical spine in low-speed rear-end automobile collisions is very limited. On this problem, just few in vitro experimental research or some experimental research using dummy on neck injury by rear-end collision was conducted, thus systematic research is requested on full scale injury mechanism. An occupant model for the response of the occupant subject to rear-end collision using commercial dynamics package DADS was developed. Developed model shows more close agreement with the experimental data compared with the MADYMO simulation results for the cases of ${\delta}V=16$ kph in sled test. For the case of ${\delta}V=8$ kph and 33.5 kph with production seat, model also shows its reliable response compared with experimental results using Hybrid III and Hybird III with RID.

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An Experimental Animal Model of Anomalous Pancreaticobiliary Duct Union (췌담관 합류이상의 실험동물 모델)

  • Han, Seok-Joo;Chang, Hang-Seok;Kim, Jong-Sung;Han, Jin-Soo;Kim, Ho-Geun;Hwang, Eui-Ho
    • Advances in pediatric surgery
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    • v.4 no.2
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    • pp.100-109
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    • 1998
  • The anomalous pancreaticobiliary duct union (APBDU) might cause the formation of choledochal cyst and malignancies of hepatopancreaticobiliary system. The purpose of this study is to make an experimental animal model of APBDU similar to that of human. One to two-month-old Mongrel dogs (n=12) were divided into two groups; the control group (n=2) had a sham operation performed, and in the experimental group (n=10) the end of distal ' common bile duct (CBD) was anastomosed to the side of the dorsal pancreatic duct making APBDD. Serum was obtained for chemical analysis on the 10th postoperative day. The dogs were sacrificed at the 5th week (n=3), the 6th week (n=3), the 7th week (n=2), the 8th week (n=2) and the 6th month (n=2) after the experimental surgery. With sacrifice, operative cholangiogram was taken, and bile juice was obtained for chemistry and bacterial culture. The en-bloc specimens of the hepatopancreaticobiliary system were removed for microscopic examination. Serum and bile juice amylase levels were elevated in the experimental group(n=10), but not in the control group(n=2). Operative cholangiograms of control group revealed no evidence of bile duct dilatation.. On the other hand, the bile duct in the experimental group was markedly dilated without any evidence of stenosis at the anastomosis site (n=10). Histologic examination of the hepatopancreaticobiliary system in the experimental group resembled the findings of choledochal cyst in human. The APBDU of this animal model can produce bile duct dilatation by pancreaticobiliary reflux. We think that this animal model can be potentially promising for the research about the APBDU associated hepatopancreaticobiliary diseases.

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Fatigue modeling of chopped strand mat/epoxy composites

  • Shokrieh, M.M.;Esmkhania, M.;Taheri-Behrooz, F.
    • Structural Engineering and Mechanics
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    • v.50 no.2
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    • pp.231-240
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    • 2014
  • In the present research, fatigue behavior of chopped strand mat/epoxy composites has been studied with two different techniques. First, the normalized stiffness degradation approach as a well-known model for unidirectional and laminated composites was utilized to predict the fatigue behavior of chopped strand mat/epoxy composites. Then, the capability of the fatigue damage accumulation model for chopped strand mat/epoxy composites was investigated. A series of tests has been performed at different stress levels to evaluate both models with the obtained results. The results of evaluation indicate a better correlation of the normalized stiffness degradation technique with experimental results in comparison with the fatigue damage accumulation model.

Wire-wrap Models for Subchannel Blockage Analysis

  • Ha K.S.;Jeong H.Y.;Chang W.P.;Kwon Y.M.;Lee Y.B.
    • Nuclear Engineering and Technology
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    • v.36 no.2
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    • pp.165-174
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    • 2004
  • The distributed resistance model has been recently implemented into the MATRA-LMR code in order to improve its prediction capability over the wire-wrap model for a flow blockage analysis in the LMR. The code capability has been investigated using experimental data observed in the FFM (Fuel Failure Mock-up)-2A and 5B for two typical flow conditions in a blocked channel. The predicted results by the MATRA-LMR with a distributed resistance model agreed well with the experimental data for wire-wrapped subchannels. However, it is suggested that the parameter n in the distributed resistance model needs to be calibrated accurately for a reasonable prediction of the temperature field under a low flow condition. Finally, the analyses of a blockage for the assembly of the KALIMER design are performed. Satisfactory results by the MATRA-LMR code were obtained through and rerified a comparison with results of the SABRE code.

Optimizing Food Processing through a New Approach to Response Surface Methodology

  • Sungsue Rheem
    • Food Science of Animal Resources
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    • v.43 no.2
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    • pp.374-381
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    • 2023
  • In a previous study, 'response surface methodology (RSM) using a fullest balanced model' was proposed to improve the optimization of food processing when a standard second-order model has a significant lack of fit. However, that methodology can be used when each factor of the experimental design has five levels. In response surface experiments for optimization, not only five-level designs, but also three-level designs are used. Therefore, the present study aimed to improve the optimization of food processing when the experimental factors have three levels through a new approach to RSM. This approach employs three-step modeling based on a second-order model, a balanced higher-order model, and a balanced highest-order model. The dataset from the experimental data in a three-level, two-factor central composite design in a previous research was used to illustrate three-step modeling and the subsequent optimization. The proposed approach to RSM predicted improved results of optimization, which are different from the predicted optimization results in the previous research.

Experimental investigations and FE simulation of exterior BCJs retrofitted with CFRP fabric

  • Halahla, Abdulsamee M.;Rahman, Muhammad K.;Al-Gadhib, Ali H.;Al-Osta, Mohammed A.;Baluch, Mohammed H.
    • Earthquakes and Structures
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    • v.17 no.4
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    • pp.337-354
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    • 2019
  • This paper presents the results of experimental and numerical studies conducted to investigate the behavior of exterior reinforced concrete beam column joints (BCJ) strengthened by using carbon fiber reinforced polymer (CFRP) sheets. Twelve reinforced concrete beam-column joints (BCJ) were tested in an experimental program by simulating the joints in seismically deficient old buildings. One group of BCJs was designed to fail in flexure at the BCJ interface, and the second group was designed to ensure joint shear failure. One specimen in each set was -retrofitted with CFRP sheet wrapped diagonally around the joint. The specimens were subjected to both monotonic and cyclic loading up to failure. 3D finite element simulation of the BCJs tested in the experimental program was carried out using the software ABAQUS, adopting the damage plasticity model (CDP) for concrete. The experimental results showed that retrofitting of the shear deficient, BCJs by CFRP sheets enhanced the strength and ductility and the failure mode changed from shear failure in the joints to the desired flexural failure in the beam segment. The FE simulation of BCJs showed a good agreement with the experimental results, which indicated that the CDP model could be used to model the problems of the monotonic and cyclic loading of beam-column reinforced concrete joints.

Numerical simulation of flow past 2D hill and valley

  • Chung, Jaeyong;Bienkiewicz, Bogusz
    • Wind and Structures
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    • v.7 no.1
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    • pp.1-12
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    • 2004
  • Numerical simulation of flow past two-dimensional hill and valley is presented. Application of three turbulence models - the standard and modified (Kato-Launder) $k-{\varepsilon}$ models and standard $k-{\omega}$ model - is discussed. The computational methodology is briefly described. The mean velocity and turbulence intensity profiles, obtained from numerical simulations of flow past the hill, are compared with the experimental data acquired in a boundary-layer wind tunnel at Colorado State University. The mean velocity, turbulence kinetic energy and Reynolds shear stress profiles from numerical simulations of flow past the valley are compared with published experimental data. Overall, the results of simulations employing the standard $k-{\varepsilon}$ model were found to be in a better agreement with the experimental data than those obtained using the modified $k-{\varepsilon}$ model and the $k-{\omega}$ model.