• Title/Summary/Keyword: S-ACC

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Micro-scale dependent static stress and strain analyses of thickness-stretching micro plate in sport application

  • Mingjun Xia
    • Advances in concrete construction
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    • v.15 no.5
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    • pp.349-358
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    • 2023
  • Aim of this work is investigating effect of thickness-stretching formulation on the quasi three-dimensional analysis of micro plate based on a thickness-stretched and shear deformable model through principle of virtual work and micro-scale dependent constitutive relations. Governing differential equations are derived in terms of five unknown functions and the analytical solution is derived using Navier's technique. To explore effect of thickness stretching model on the static results, a comparison between the results with and without thickness stretching effect is presented.

Procedure for the correct placement of Long-Thread Short-Thread couplers in mechanical connections of reinforcing bars

  • Enrique Hernandez-Montes;Fouzia Larbi-Chaht;Mohamed Mouli;Lahouari Mammar;Sadek Mahdjouba;Ahmed M. Mohamed;Abdelkader Medjahed;Ahmed Messaoud-Djebara;Luisa Maria Gil-Martin
    • Advances in concrete construction
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    • v.16 no.2
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    • pp.91-96
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    • 2023
  • The present work provides a new solution to both the correct execution and quality control of straight thread couplers for reinforcing bars under monotonic loading conditions. A random survey on already constructed couplers together with a new mechanical model, adjusted with an experimental campaign, led us to present this new procedure in reinforced concrete construction. Formulation and methodology for a correct placement of straight thread couplers is presented.

A Study on the Properties of Epoxy Based Powder Coating with Various Curing Agents (에폭시 분체도료의 경화제 종류에 따른 물성에 관한 연구)

  • Park, Jae-Hong;Shin, Young-Jo
    • Applied Chemistry for Engineering
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    • v.9 no.1
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    • pp.58-65
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    • 1998
  • Substituted dicyandiamide(Sub-DICY), Accelerated dicyandiamide(Acc-DICY), Trimellitic anhydride(TMA), Pyromellitic dianhydride(PMDA) and Phenolic curing agent(Ph.C.A.) are mainly used for epoxy powder coating curing agent. Various characteristics of epoxy films fully cured by optimum condition such as mechanical properties like $T_g$, tensile strength, elongation at break hardness, abrasion resistance and chemical properties like water absorption, acid resistance, alkali resistance and electrical properties, corrosion resistance are determined by various measuring devices and analyses devices. In conclusion, phenolic curing agent was shown excellent thoughness but severe color change as temperature increased. Acid anhydride has excellent insulation properties and color stability at elevated temperature but lower thoughness and adhesion to substrate. DICY curing agent was shown high water absorption and severe color chance as temperature increased.

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Numerical study for nonlocal vibration of orthotropic SWCNTs based on Kelvin's model

  • Hussain, Muzamal;Naeem, Muhammad N.;Tounsi, Abdelouahed
    • Advances in concrete construction
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    • v.9 no.3
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    • pp.301-312
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    • 2020
  • This research deals with the study of the orthotropic vibrational features of single-walled carbon nanotubes according to Kelvin's model and to check the accuracy of the models, the results have been compared with earlier modeling/simulations. Obtaining rough approximations of the natural frequencies of CNTs using continuum equations are still a common procedure, even at high harmonics. The effects of different physical and material parameters on the fundamental frequencies are investigated for zigzag and chiral single-walled carbon nanotubes invoking Kelvin's theory. By using nonlocal Kelvin's model, the fundamental natural frequency spectra for two forms of single-walled carbon nanotubes (SWCNTs) have been calculated. The influence of frequencies with nonlocal parameters and bending rigidity are investigated in detail for these tubes. Computer software MATLAB is utilized for the frequencies of SWCNTs and current results shows a good stability with comparison of other studies.

Diffusion study for chloride ions and water molecules in C-S-H gel in nano-scale using molecular dynamics: Case study of tobermorite

  • Zehtab, Behnam;Tarighat, Amir
    • Advances in concrete construction
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    • v.4 no.4
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    • pp.305-317
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    • 2016
  • Porous materials such as concrete could be subjected to aggressive ions transport. Durability of cement paste is extremely depended on water and ions penetration into its interior sections. These ions transport could lead different damages depending on reactivity of ions, their concentrations and diffusion coefficients. In this paper, chloride diffusion process in cement hydrates is simulated at atomistic scale using molecular dynamics. Most important phase of cement hydrates is calcium silicate hydrate (C-S-H). Tobermorite, one of the most famous crystal analogues of C-S-H, is used as substrate in the simulation model. To conduct simulation, a nanopore is considered in the middle of simulation cell to place water molecules and aggressive ions. Different chloride salts are considered in models to find out which one is better for calculation of the transport properties. Diffusion coefficients of water molecules and chloride ions are calculated and validated with existing analytical and experimental works. There are relatively good agreements among simulation outputs and experimental results.

Role of S-Adenosylemthionine as an Intermediate in Relation between Polyamine and Ethylene Biosynthesis in Suspension-Cultured Tobacco Cells (담배 현탁배양 세포에 있어 Polyamine 과 Ethylene 생합성시 중간산물로서 S-Adenosylmethionine의 역할)

  • 박기영
    • Journal of Plant Biology
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    • v.33 no.2
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    • pp.87-96
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    • 1990
  • The role of S-adenosylmethionine (SAM) as an intermediate in interrelation between polyamine and ethylene biosynthesis was studied in suspension cultures of Nicotiana tabacum L. Exogenous SAM stimulated the polyamine and ethylene biosynthesis in 4 day-cultured cells, which were in active cell divisions, and 10 day cultured cells, which went on with active cell elongation and senescence. SAM-induced ethylene production was more effective in 10 day-cultured cells than in 4 day-cultured cells, but SAM-induced polyamine biosynthesis was more effective in 4 day-cultured cells than in 10 day-cultured cells. Polyamine contents were increased by the blockage of ethylene biosynthetic pathway in the conversion of SAM to ethylene via 1-aminocyclopropane-1-carboxylinc acid (ACC) with aminooxyacetic acid (AOA). Also, ethylene production was increased by the inhibitors of polyamine biosynthesis such as methylglyoxal bis-(guanylhydrazone) (MGBG), dicyclohexylamine (DCHA), $\alpha$-difluoromethylarginine (DFMA) and $\alpha$-difluoromethylorinithine (DFMO). These results suggest that there may be interrelations between polyamine and ethylene biosynthesis for the competition of SAM and the inherent mechanism of switch on-off in polyamine and ethylene biosynthetic activity with the progress of cell growth and senescence.

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SOFTWARE ARCHITECTURE FOR ADAPTIVE COLLISION AVOIDANCE SYSTEMS

  • Blum, Jeremy;Eskandarian, Azim
    • International Journal of Automotive Technology
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    • v.3 no.2
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    • pp.79-88
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    • 2002
  • Emergent Collision Avoidance Systems (CAS's) are beginning to assist drivers by performing specific tasks and extending the limits of driver's perception. As CAS's evolve from simple systems handling discrete tasks to complex systems managing interrelated driving tasks, the risk of failure from hidden causes greatly increases. The successful implementation of such a complex system depends upon a robust software architecture. Host of the difficulty in implementing system arises from interconnections between the components. The CAS architecture presented in this paper focuses on these interconnections to mitigate this problem. Moreover, by constructing the GAS architecture through the composition of existing architectural styles, the resulting system will exhibit predictable qualities. Some of the qualities represent limitations that translate into constraints on the system. Others are beneficial aspects that satisfy stakeholder requirements .

Application of Kelvin's theory for structural assessment of FG rotating cylindrical shell: Vibration control

  • Khadimallah, Mohamed A.;Hussain, Muzamal;Harbaoui, Imene
    • Advances in concrete construction
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    • v.10 no.6
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    • pp.499-507
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    • 2020
  • In current study, utilizing the Kelvin's theory with polynomial, exponential and trigonometric volume fraction laws for functionally graded cylindrical shell vibrations. Effects of different parameters for ratios of length- and height-to-radius and angular speed versus fundamental natural frequencies been determined for two categories of cylindrical shells with clamped-free edge condition. By increasing different value of height-to-radius ratio, the resulting backward and forward frequencies increase and frequencies decrease on increasing length-to-radius ratio. Moreover, on increasing the rotating speed, the backward frequencies increases and forward frequencies decreases. The frequencies are same when the cylinder is stationary. The frequencies increases and decreases on changing the constituent materials. The frequency results are verified with the earlier literature for the applicability of present model.

Ensemble Learning Based on Tumor Internal and External Imaging Patch to Predict the Recurrence of Non-small Cell Lung Cancer Patients in Chest CT Image (흉부 CT 영상에서 비소세포폐암 환자의 재발 예측을 위한 종양 내외부 영상 패치 기반 앙상블 학습)

  • Lee, Ye-Sel;Cho, A-Hyun;Hong, Helen
    • Journal of Korea Multimedia Society
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    • v.24 no.3
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    • pp.373-381
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    • 2021
  • In this paper, we propose a classification model based on convolutional neural network(CNN) for predicting 2-year recurrence in non-small cell lung cancer(NSCLC) patients using preoperative chest CT images. Based on the region of interest(ROI) defined as the tumor internal and external area, the input images consist of an intratumoral patch, a peritumoral patch and a peritumoral texture patch focusing on the texture information of the peritumoral patch. Each patch is trained through AlexNet pretrained on ImageNet to explore the usefulness and performance of various patches. Additionally, ensemble learning of network trained with each patch analyzes the performance of different patch combination. Compared with all results, the ensemble model with intratumoral and peritumoral patches achieved the best performance (ACC=98.28%, Sensitivity=100%, NPV=100%).