• Journal of Photoscience
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• v.9 no.2
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• pp.299-301
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• 2002

Recent denaturation experiments of bacteriorhodopsin (bR) in the dark and under illumination at high temperatures revealed that irreversible thermal bleaching occurs above ~ 70°C and the preceding reversible structural changes in the dark above 60°C are closely related to irreversible photobleaching observed in the same temperature range (Yokoyama et al. (2002). J Biochem. 131,785). In this study, structural properties of bacteriorhodopsin (bR) at high temperatures were extensively probed by hydroxylamine reactivity with the Schiff base in the dark and hydrogen-deuterium (H-D) exchange in the peptide groups. In the Arrhenius plot from kinetics measurements of the hydroxylamine reaction, a good linear relationship between the reaction time constant and the inverse of the absolute temperature was observed below 60°C, while significant increase started above 60°C, suggesting that remarkable increase in water accessibility of the Schiff base in the temperature region. FT-IR spectroscopic studies on the H-D exchange suggested increase in the deuterium exchanges rate of the peptide hydrogen in the same temperature region.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.7-12
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• 2011

Hydraulic excavator in digging at the construction machinery is a widely used mechanical device. Excavator attachments are taken with structural load and fatigue during digging under applied reaction. Fatigue analysis is done at joint pin between bucket and arm of front attachment at excavator under the force of hydraulic cylinder in operation. It is analyzed how load can be supported at the lower driving body applied on the bucket. In this study, the deformation of arm and the fatigue result are examined when reaction force is applied on the attachment of excavator.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.11
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• pp.143-151
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• 1996

Structural reaction injection molding을 이용한 복합재료의 제품 셩형을 위한 모델링 전략을 설명하였다. 사용된 모델은 두 평행한 원판형 mold에 있는 불 균일한 온도조건의 fiber preform을 통과하는 reactive srsin의 방사형 유동을 시뮬레이션 한다. 이러한 모델은 중요한 작동인자와 공정인자(주입온도, mold의 온도, 유량, cavity의 두께와 섬유의 조밀도)등이 유동속도, 변화(monomer, radical, inhibitor) 및 온도분포 등에 미치는 영향을 예견한다. 열전달과 질량전달 및 화학반응을 고려하여 모델을 개발하였다. 중요한 공정인자를 평가하기 위한 효울적인 공정창( process window)을 제공하는데 본 연구의 목적을 두었다. 2차원적인 Lagrangian 방식에 1차원적인 유동과 제한적인 2차원 열전달을 가정하여 모델을 유도하였고, 방정식은 implicit difference scheme에 의해 전개하였다. 이 모델은 Gonzalez-Romero의 실험 결과와 비교함에 의해 확인되었고, 실험결과가 잘 일치함을 보였다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.381-387
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• 2002

Curved bridges are composed of curved members which have certain curvatures, comparing to straight bridges. Therefore, their behavior is quite different from one of the straight bridges, mainly due to the geometric characteristics of the curved bridges. In this paper, the curved bridges consisted of the single box-girder span are investigated to study the effects of negative reaction forces. The parameters considered in this study are span lengths, angles of curvature, and the number of shoes. Midas/civil computer program was used for the analysis of the curved bridges. The analysis results show that negative reaction forces are not created with one shoe installed. When two shoes are provided, on the other hands, the uplift forces are developed at the inside shoe. It is also concluded that the increasing ratio of negative reaction forces becomes larger, as the angles of curvature increase, and the elongation of span lengths turns out to increase the magnitudes of the uplift forces.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.6
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• pp.661-668
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• 2017

The purpose of this study is to analyze the chemical reaction pathway for explosion accident of mixed cargo. The analysis used a structural scenario using event-tree analysis. Structural scenarios were constructed by estimating various chemical reaction paths in the content of the mixed cargo accident recorded in the written verdict. The analytical method was applied to three kinds of analysis: chemical analysis based on chemical theory, quantitative analysis using chemical reaction formula, and probabilistic analysis through questionnaire. As a result of analysis, the main pathway of the accident occurred in three ways: the path of explosion due to the reaction of concentrated sulfuric acid with water, the path of explosion due to the reaction of metal and mixed acid, and the path of explosion by synthesizing with special substances. This result is similar to the path recorded in the validation, and it leads to thar the proposed path analysis method is valid. The proposed method is expected to be applicable to chemical reaction path estimation of various chemical accidents.

• Journal of Magnetics
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• v.19 no.1
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• pp.64-67
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• 2014

$Ni_{0.6}Zn_{0.4}Fe_2O_4$ prepared using solid state reaction and sol-gel methods were compared for their structural and magnetic properties. Due to the much higher annealing temperature used in solid state reaction, the crystalline size was much larger than that of the nanoparticles prepared by sol-gel. The saturation magnetization of sol-gel nanoparticles was higher, and the coercivity was about 2 times larger, compared to the solid state reaction sample. By analyzing the integration intensity of x-ray diffraction peaks (220) and (222), we proposed that the difference in the saturation magnetization might be due to the inversion of cation distribution caused by the different preparation techniques used.

• Journal of the Korean institute of surface engineering
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• v.38 no.3
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• pp.112-117
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• 2005

In this paper, CdS thin films, which were widely used as a window layer of the CdS/CdTe and the $CdS/CuInSe_2$heterojunction solar cell, were grown by chemical bath deposition, and the structural, optical and electrical properties of the films on reaction temperatures were investigated. Cadmium acetate and thiourea were used as cadmium and sulfur source, respectively. And Ammonium acetate was used as the buffer solution. As the reaction temperatures were increased, the deposition rate of CdS fllms prepared by CBD was increased and the grain size was large due to increasing reaction rate in solution, also optical transmittance of the films in visible lights was increased on rising reaction temperatures.

• International Journal of Automotive Technology
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• v.8 no.6
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• pp.745-752
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• 2007

In this study, the effects of flexible bodies in vehicle suspension components were investigated to enhance the accuracy of multibody dynamic simulation results. Front and rear suspension components were investigated. Subframes, a stabilizer bar, a tie rod, a front lower control arm, a front knuckle, and front struts were selected. Reverse engineering techniques were used to construct a virtual vehicle model. Hard points and inertia data of the components were measured with surface scanning equipment. The mechanical characteristics of bushings and dampers were obtained from experiments. Reaction forces calculated from the multibody dynamics simulations were compared with test results at the ball joint of the lower control arm in both time-history and range-pair counting plots. Simulation results showed that the flexibility of the strut component had considerable influence on the lateral reaction force. Among the suspension components, the flexibility of the sub-frame, steering knuckle and upper strut resulted in better correlations with test results while the other flexible bodies could be neglected.

• Journal of Aerospace System Engineering
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• v.14 no.6
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• pp.18-25
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• 2020

This study investigated the structural behaviors and safety of an electro-mechanical linear actuator and a load simulator with a plate spring. The material and dimensions of the plate spring were determined by theoretically calculating the stress and torsional angle for the rating load of the actuator. Thereafter, a flexible multibody dynamics (FMBD) analysis was conducted on the linear actuator and load simulator to confirm the performance of the load simulator and acquire the reaction forces acting on the actuator and simulator. The structural safety of the linear actuator and load simulator was evaluated via finite element analysis using the aforementioned reaction forces. Consequently, the proposed linear actuator and load simulator were determined to be structurally safe; however, the safety factors for the actuation rod and the housing on the actuator were excessively high. Therefore, the weight and cost must be reduced to improve their design parameters in the future.

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.277.2-277
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• 1995

No Abstract, See Full Text