• Title/Summary/Keyword: stress regions

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Molecular Characterization of a Transient Expression Gene Encoding for 1-Aminocyclopropane-1-carboxylate Synthase in Cotton (Gossypium hirsutum L.)

  • Wang, Xia;Zhang, Ying;Zhang, Jiedao;Cheng, Cheng;Guo, Xingqi
    • BMB Reports
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    • v.40 no.5
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    • pp.791-800
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    • 2007
  • Ethylene performs an important function in plant growth and development. 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS), the key enzyme involved in ethylene biosynthesis, has been the focus of most ethylene studies. Here, a cotton ACS gene referred to as Gossypium hirsutum ACS1 (GhACS1), was isolated. The full-length cDNA of GhACS1 encodes for a 476-amino acid protein which harbors seven conserved regions, 11 invariant amino acid residues, and the PLP binding active site, all of which characterize ACC synthases. Alignment analysis showed that GhACS1 shared a high degree of identity with other known ACC synthases from different species. Two introns were detected in the genomic DNA sequence, and the results of Southern blot analysis suggested that there might be a multi-gene family encoding for ACC synthase in cotton. From the phylogenetic tree constructed with 24 different kinds of ACC synthases, we determined that GhACS1 falls into group II, and was closely associated with the wound-inducible ACS of citrus. The analysis of the 5' flanking region of GhACS1 revealed a group of putative cis-acting elements. The results of expression analysis showed that GhACS1 displayed its transient expression nature after wounding, abscisic acid (ABA), and $CuCl_2$ treatments. These results indicate that GhACS1, which was transiently expressed in response to certain stimuli, may be involved in the production of ethylene for the transmission of stress signals.

Dynamic response of functionally gradient austenitic-ferritic steel composite panels under thermo-mechanical loadings

  • Isavand, S.;Bodaghi, M.;Shakeri, M.;Mohandesi, J. Aghazadeh
    • Steel and Composite Structures
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    • v.18 no.1
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    • pp.1-28
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    • 2015
  • In this paper, the dynamic response of functionally gradient steel (FGS) composite cylindrical panels in steady-state thermal environments subjected to impulsive loads is investigated for the first time. FGSs composed of graded ferritic and austenitic regions together with bainite and martensite intermediate layers are analyzed. Thermo-mechanical material properties of FGS composites are predicted according to the microhardness profile of FGS composites and approximated with appropriate functions. Based on the three-dimensional theory of thermo-elasticity, the governing equations of motionare derived in spatial and time domains. These equations are solved using the hybrid Fourier series expansion-Galerkin finite element method-Newmark approach for simply supported boundary conditions. The present solution is then applied to the thermo-elastic dynamic analysis of cylindrical panels with three different arrangements of material compositions of FGSs including ${\alpha}{\beta}{\gamma}M{\gamma}$, ${\alpha}{\beta}{\gamma}{\beta}{\alpha}$ and ${\gamma}{\beta}{\alpha}{\beta}{\gamma}$ composites. Benchmark results on the displacement and stress time-histories of FGS cylindrical panels in thermal environments under various pulse loads are presented and discussed in detail. Due to the absence of similar results in the specialized literature, this paper is likely to fill a gap in the state of the art of this problem, and provide pertinent results that are instrumental in the design of FGS structures under time-dependent mechanical loadings.

Strut-Tie Model Approach Associated with 3-Dimensional Grid Elements for Design of Structural Concrete - (I) Proposal of Approach (3차원 격자요소를 활용한 콘크리트 구조부재의 스트럿-타이 모델 설계 방법 - (I) 방법의 제안)

  • Kim, Byung Hun;Yun, Young Mook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.34 no.2
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    • pp.425-436
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    • 2014
  • Although the strut-tie model approaches of current design codes are regarded as the valuable methods for designs of structural concretes with D-regions, the approaches have to be improved because of the uncertainties in terms of the concepts and provisions for designs of 3-dimensional structural concretes. To improve the uncertainties, a new strut-tie model approach is proposed in this study. In the proposed approach, the concepts of employing a 3-dimensional grid element allowing load transfers in all directions at a node to construct a strut-tie model, a numerical analysis approach to determine the effective strengths of concrete struts and nodal zones by reflecting the effects of reinforcing bars and 3-dimensional stress state, and maximum areas of struts and ties to examine their load carrying capacities are integrated into the strut-tie model approaches of current design codes.

Case Study of Correlation between the SPT-N Value and PMT Results Performed on Weathered Granite Zone in Korea (국내 화강 풍화대 지반의 표준관입시험 N 값과 프레셔미터시험 결과의 상관관계에 대한 사례 분석)

  • Lee, Seung-Hwan;Baek, Sung-Ha;Song, Young-Woo;Chung, Choong-Ki
    • Journal of the Korean Geotechnical Society
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    • v.35 no.12
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    • pp.15-24
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    • 2019
  • Weathered granite zone exists in most regions of Korea and it is often used as a bearing stratum of geotechnical structures. So it is very important to estimate the characteristics of weathered granite zone. SPT (Standard penetration test) is usually performed to investigate the characteristics of the weathered zone because undisturbed samples suitable for laboratory testing are hardly retrieved. PMT (Pressuremeter test) can reliably evaluate the in situ stress-strain behavior, but it is rarely conducted because of their high cost and time-consuming procedure. In this study, the correlation between the SPT-N values and the PMT results, obtained from the weathered granite zone, was analyzed. Empirical equations for pressuremeter modulus (Em) and limit pressure (PL) were suggested and compared with the previous research.

STRAIN ON THE LABIAL PLATES AROUND ABUTMENTS SUPPORTING REMOVABLE PARTIAL DENTURES WITH VARIOUS PROSTHETIC DESIGNS: AN IN VITRO STUDY

  • Kim, Seong-Kyun
    • The Journal of Korean Academy of Prosthodontics
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    • v.43 no.3
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    • pp.322-330
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    • 2005
  • Statement of problem. In distal extension removable partial denture, the preservation of health of abutment teeth is very important, but abutment teeth are subjected to unfavorable stress. Purpose. The purpose of this study was to investigate the biomechanical effects of mandibular removable partial dentures with various prosthetic designs using strain gauge analysis. Material and methods. Artificial teeth of both canines were anchored bilaterally in a mandibular edentulous model made of resin. Bilateral distal extension removable partial dentures with splinted and unsplinted abutments were fabricated. Group 1 : Clasp-retained mandibular removable partial denture with unsplinted abuhnents Group 2 : Clasp-retained mandibular removable partial denture with splinted abutments by 6-unit bridge Group 3 : Bar-retained mandibular removable partial denture Strain gauges were bonded on the labial plate of the mandibular resin model, approximately 2 mm close to the abutments. Two vertical experimental loadings (100N and 200N) were applied subsequently via two miniature load cells that were placed at mandibular first molar regions. Strain measurements were performed and simultaneously monitored from a computer connected to data acquisition system. For within-group evaluations, t-test was used to compare the strain values and for between-group comparisons, a one-way analysis of variance (ANOVA) was used and Duncan test was used as post hoc comparisons. Results. Strain values increased as the applied load increased from 100N to 200N for all groups (p<.05). The strain values of group 1 and 2 were tensile under loadings. In contrast, strain values of group 3 were compressive in nature. Under 100N loading, group 1 showed higher strain values than group 3 in absolute quantity (p<.05). Under 200N loading, group 3 showed higher strain values than group 1 and 2 in absolute quantity (p<.05). Group 1 showed higher strain values than group 2 (p<.05). Conclusion. Splinting of two isolated abutments by bridge reduced the peri-abutment strain in comparison with unsplinted abutments. Strain of bar-retained removable partial denture increased much more as applied load increased, but was compressive in nature.

Effects of Inlet Turbulence Conditions and Near-wall Treatment Methods on Heat Transfer Prediction over Gas Turbine Vanes

  • Bak, Jeong-Gyu;Cho, Jinsoo;Lee, Seawook;Kang, Young Seok
    • International Journal of Aeronautical and Space Sciences
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    • v.17 no.1
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    • pp.8-19
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    • 2016
  • This paper investigates the effects of inlet turbulence conditions and near-wall treatment methods on the heat transfer prediction of gas turbine vanes within the range of engine relevant turbulence conditions. The two near-wall treatment methods, the wall-function and low-Reynolds number method, were combined with the SST and ${\omega}RSM$ turbulence model. Additionally, the RNG $k-{\varepsilon}$, SSG RSM, and $SST_+{\gamma}-Re_{\theta}$ transition model were adopted for the purpose of comparison. All computations were conducted using a commercial CFD code, CFX, considering a three-dimensional, steady, compressible flow. The conjugate heat transfer method was applied to all simulation cases with internally cooled NASA turbine vanes. The CFD results at mid-span were compared with the measured data under different inlet turbulence conditions. In the SST solutions, on the pressure side, both the wall-function and low-Reynolds number method exhibited a reasonable agreement with the measured data. On the suction side, however, both wall-function and low-Reynolds number method failed to predict the variations of heat transfer coefficient and temperature caused by boundary layer flow transition. In the ${\omega}RSM$ results, the wall-function showed reasonable predictions for both the heat transfer coefficient and temperature variations including flow transition onset on suction side, but, low-Reynolds methods did not properly capture the variation of the heat transfer coefficient. The $SST_+{\gamma}-Re_{\theta}$ transition model showed variation of the heat transfer coefficient on the transition regions, but did not capture the proper transition onset location, and was found to be much more sensitive to the inlet turbulence length scale. Overall, the Reynolds stress model and wall function configuration showed the reasonable predictions in presented cases.

A Study on the Management System and the Facility Type of Mental Health and Welfare Center in Japan (1) (일본 정신보건복지센터의 운영체계 및 시설유형 분석연구 (1))

  • Lim, Yenjung;Chai, Choul-Gyun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.20 no.4
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    • pp.57-65
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    • 2014
  • Purpose : Mental health service desire has been diversified according to the increase of economic level and rapid social change. Mental Health and Welfare Center(MHWC) is a provider of mental health services in Japan. This is a basic stage study which will suggest the architectural planning guidelines for MHWC. Methods : Data were collected through literature research, field surveys, and expert interviews to 69 MHWC in Japan. 1) Research for the policy and legal aspects of mental health support system. 2) Research for structural aspects of MHWC: Characteristics of establishment, management, and regional factors. 3) Research for the physical environment aspects of MHWC: Classification and evaluation of MHWC's Type by locational characteristics in Japan. Results : The result of this study can be summarized into three points. The first one, Mental Health and Welfare Center's service has being expanded to suicide, depression and stress from chronic mental illness, to reflect social needs. The second one, The average population of area installed at Mental Health and Welfare Center was 2,307,570 person, and average area of the regions were $5,745m^2$. The third one, Mental Health and Welfare Center is divided into single-structure type and combine-structure type. And combine-structure type is divided into medical-combine type, welfare-combine type, and public-combine type.

Deformation Behaviors around Tunnel in Anisotropic Rocks Considering Joint Orientation and Rock Pressure Condition Using Scaled Model Tests (이방성 암반의 방향성과 측압조건을 고려한 터널 모형실험 연구)

  • Jung, Hyung-Rae;Kim, Jong-Woo
    • Tunnel and Underground Space
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    • v.16 no.4 s.63
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    • pp.313-325
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    • 2006
  • In this study, scaled model tests were performed to investigate the deformation behaviors around tunnels located in anisotropic rocks. Fifteen types of test models which had respectively different joint angles and rock pressure conditions were made, where the modelling materials were the mixture of sand, plaster and water. All of the tested models showed the shear failure mechanism at the stress-concentrated regions and sliding phenomena according to the joint planes. The direction of joint inclination turned out to have great effect on the tunnel deformation behaviors. The models of joint inclination less than $30^{\circ}$ showed considerable floor heavings. The model of $50^{\circ}$ joint inclination showed the least tunnel convergence among the tested models regardless of rock pressure condition, so that it was thought as the most stable model. Furthermore, the failure mechanisms and deformation behaviors of tunnel models were strongly dependent on the coefficient of rock pressure.

An investigation and forecast on CO2 emission of China: Case studies of Beijing and Tianjin

  • Wen, Lei;Ma, Zeyang;Li, Yue;Li, Qiao
    • Environmental Engineering Research
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    • v.22 no.4
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    • pp.407-416
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    • 2017
  • $CO_2$ emission is increasingly focused by public. Beijing and Tianjin are conceived to be a new economic point of growth in China. However, both of them are suffering serious environmental stress. In order to seek for the effect of socioeconomic factors on the $CO_2$ emission of this region, a novel methodology -symbolic regression- is adopted to investigate the relationship between $CO_2$ emission and influential factors of Beijing and Tianjin. Based on this method, $CO_2$ emission models of Beijing and Tianjin are built respectively. The models results manifested that Beijing and Tianjin own different $CO_2$ emission indicators. The RMSE of models in Beijing and Tianjin are 255.39 and 603.99, respectively. Further analysis on indicators and forecast trend shows that $CO_2$ emission of Beijing expresses an inverted-U shaped curve, whilst Tianjin owns a monotonically increasing trend. From analytical results, it could be argued that the diversity rooted in different development orientation and the mixture of different natural and industrial environment. This research further expands the investigation on $CO_2$ emission of Beijing and Tianjin region, and can be used for reference in the study of carbon emissions in similar regions. Based on the investigation, several policy suggestions are presented.

A Study on Improvement of 100 Tons Toggle Injection Molding Machine's Weight Using Numerical Analysis (수치해석을 이용한 토글식 100톤 사출성형기의 중량 개선에 관한 연구)

  • Han, Seong-Ryeol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.4713-4718
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    • 2013
  • Nowadays, three-dimensional computer added design(3D CAD) tool are widely and actively used for design of mechanical machine. Because using the tool is more effective to understand design concept and to collaborate with other operation than using two-dimensional design tool. In this study, the 3D CAD tool which is called I-DEAS was applied for three-dimensional modeling of main parts and assembling of modeled parts for identification the entire shape of a injection molding machine. In addition, a study was also performed regarding reduction for the weight of main plates for saving production cost and energy in the machine. A finite element method(FEM) program in I-DEAS tool was used for the improvement study. First, the current main plates were structural analysed and then the plate deformations, weak regions and stress distributions were graped. By the FEM results, the 2nd improved designing of the plates was conducted such as reinforcement or slimming of the plate wall thickness. The 2nd structural FEM was performed for verification of the redesigned plates and then the FEM results were compared with the 1st FEM's result. The weight of the main plates were averagely reduced approximately 3 - 7%. By these results, it was seemed that the improved plates have a useful availability.