• Advances in nano research
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• v.9 no.4
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• pp.263-276
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• 2020

In this article, the acoustic responses of free vibrated natural fibre-reinforced polymer nanocomposite structure have been investigated first time with the help of commercial package (ANSYS) using the multiphysical modelling approach. The sound relevant data of the polymeric structure is obtained by varying weight fractions of the natural nanofibre within the composite. Firstly, the structural frequencies are obtained through a simulation model prepared in ANSYS and solved through the static structural analysis module. Further, the corresponding sound data within a certain range of frequencies are evaluated by modelling the medium through the boundary element steps with adequate coupling between structure and fluid via LMS Virtual Lab. The simulation model validity has been established by comparing the frequency and sound responses with published results. In addition, sets of experimentation are carried out for the eigenvalue and the sound pressure level for different weight fractions of natural fibre and compared with own simulation data. The experimental frequencies are obtained using own impact type vibration analyzer and recorded through LABVIEW support software. Similarly, the noise data due to the harmonically excited vibrating plate are recorded through the available Array microphone (40 PH and serial no: 190569). The numerical results and subsequent experimental comparison are indicating the comprehensiveness of the presently derived simulation model. Finally, the effects of structural design parameters (thickness ratio, aspect ratio and boundary conditions) on the acoustic behaviour of the natural-fibre reinforced nanocomposite are computed using the present multiphysical model and highlighted the inferences.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.1
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• pp.36-47
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• 2012

In this study, the control performance of resonator was reviewed through numerical analysis and 3-dimensional hydraulic model experiments by attaching the resonator suggested in the existing studies to the openings of rectangular harbor and breakwater placed in a straight line to reduce short-period waves. In the numerical analysis, linear analysis method of singularity distribution method based on vertical-line Green function and full non-linear analysis method by 3D-NIT model were applied, and the validity of the numerical analysis methods was verified through comparative analysis between results of hydraulic experiments and numerical analysis results. In addition, effectiveness of the resonator was confirmed by reviewing its control performance on the short-period waves through review on the comparison with the case in which the resonator is not attached.

• Structural Engineering and Mechanics
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• v.73 no.6
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• pp.715-724
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• 2020

The influence on flexural strength of Glass/Epoxy laminated composite curved panels of different geometries (cylindrical, spherical, elliptical, hyperboloid and flat) due to inclusion of nano cenosphere filler examined in this research article. The deflection responses of the hybrid structure are evaluated numerically using the isoparametric finite element technique and modelled mathematically via higher-order displacement structural kinematics. To predict the deflection values, a customised in-house computer code in MATLAB environment is prepared using the higher-order isoparametric formulation. Subsequently, the numerical model validity has been established by comparing with those of available benchmark solution including the convergence characteristics of the finite element solution. Further, a few cenosphere filled hybrid composite are prepared for different volume fractions for the experimental purpose, to review the propose model accuracy. The experimental deflection values are compared with the finite element solutions, where the experimental elastic properties are adopted for the computation. Finally, the effect of different variable design dependent parameter and the percentages of nano cenosphere including the geometrical shapes obtained via a set of numerical experimentation.

• The Plant Pathology Journal
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• v.27 no.3
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• pp.280-284
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• 2011

Fusarium wilt of banana caused by Fusarium oxysporum f. sp. cubense is widespread in Indonesia. However, the distribution of tropical race 4 strains has not been well studied. Thirty nine isolates of F. oxysporum f. sp. cubense were collected from Java and 7 isolates were from Sumatera, Bangka, and Kalimantan. All isolates produced volatile odor when grown on steamed rice. These isolates were further tested for their vegetative compatibility with nitM testers of 20 reported vegetative compatibility groups representing strains that belong to race 1, 2, and 4. Three isolates formed heterokaryons with nitM testers belong to race 1, 11 isolates with race 4, and the rest did not form heterokaryons with all nitM testers used. F. oxysporum f. sp. cubense tropical race 4 specific primer pair was used to amplify a 1400 bp fragment of tropical race 4 DNA. Seven isolates (Bnt2, Mln1, Srg1, Bgl3, Bgl6, Lmp1, and Kjg1) produced the 1400 bp amplification product were therefore tropical race 4.

• Advances in concrete construction
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• v.2 no.4
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• pp.309-324
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• 2014

In the design of reinforced concrete structural walls, in order to ensure adequate inelastic displacement behaviour and to sustain deformation demands imposed by strong ground motions, special reinforcement is considered while designing. However, these would lead to severe reinforcement congestion and difficulties during construction. Addition of randomly distributed discrete fibres in concrete improves the flexural behaviour of structural elements because of its enhanced tensile properties and this leads to reduction in congestion. This paper deals with effect of addition of steel fibres on the behavior of high performance fibre reinforced cement concrete (HPFRCC) slender structural walls with the different volume fractions of steel fibres. The specimens were subjected to quasi static lateral reverse cyclic loading until failure. The high performance concrete (HPC) used was obtained based on the guidelines given in ACI 211.1 which was further modified by prof.Aitcin (1998). The volume fraction of the fibres used in this study varied from 0 to 1% with an increment of 0.5%. The results were analysed critically and appraised. The study indicates that the addition of steel fibres in the HPC structural walls enhances the first crack load, strength, initial stiffness and energy dissipation capacity.

• Interaction and multiscale mechanics
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• v.3 no.1
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• pp.23-37
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• 2010

Concrete is a heterogeneous material consisting of coarse aggregate, mortar matrix and interfacial zones at the meso level. Though studies have been done to interpret the fracture process in concrete using meso level models, not much work has been done for simulating the macroscopic behaviour of reinforced concrete structures using the meso level models. This paper presents a procedure for the mesoscopic analysis of reinforced concrete beams using a modified micro truss model. The micro truss model is derived based on the framework method and uses the lattice meshes for representing the coarse aggregate (CA), mortar matrix, interfacial zones and reinforcement bars. A simple procedure for generating a random aggregate structure is developed using the constitutive model at meso level. The study reveals the potential of the mesoscopic numerical simulation using a modified micro truss model to predict the nonlinear response of reinforced concrete structures. The modified micro truss model correctly predicts the load-deflection behaviour, crack pattern and ultimate load of reinforced concrete beams failing under different failure modes.

• Advances in nano research
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• v.7 no.6
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• pp.419-429
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• 2019

The effect of an increasing percentage of nanofiller (glass cenosphere) with Glass/Epoxy hybrid composite curved panels modeled mathematically using the multiscale concept and subsequent numerical eigenvalues of different geometrical configurations (cylindrical, spherical, elliptical, hyperboloid and flat) predicted in this research article. The numerical model of Glass/Epoxy/Cenosphere is derived using the higher-order polynomial type of kinematic theory in association with isoparametric finite element technique. The multiscale mathematical model utilized for the customized computer code for the evaluation of the frequency data. The numerical model validation and consistency verified with experimental frequency data and convergence test including the experimental elastic properties. The experimental frequencies of the multiscale nano filler-reinforced composite are recorded through the impact hammer frequency test rig including CDAQ-9178 (National Instruments) and LABVIEW virtual programming. Finally, the nano cenosphere filler percentage and different design associated geometrical parameters on the natural frequency data of hybrid composite structural configurations are illustrated through a series of numerical examples.

• Advances in concrete construction
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• v.7 no.4
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• pp.263-275
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• 2019

In the present work, Granulated Blast Furnace Slag (GBFS) and Fly ash (FA) were used as partial replacement of Natural Sand (NS) and Ordinary Portland Cement (OPC) by weight. One control mix, one with GBFS, three with FA and three with GBFS-FA combined mixes were prepared. Replacements were 50% GBFS with NS and 20%, 30% and 40% FA with OPC. Preliminary investigation on development of compressive strength was carried out at 7, 28 and 90 days to ensure sustainability of waste materials in concrete matrix at room temperature. After 90days, thermo-mechanical study was performed on the specimen for a temperature regime of $200^{\circ}-1000^{\circ}C$ followed by furnace cooling. Weight loss, visual inspection along with colour change, residual compressive strength and microstructure analysis were performed to investigate the effect of replacement of GBFS and FA. Although adding waste mineral by-products enhanced the weight loss, their pozzolanicity and formation history at high temperature played a significant role in retaining higher residual compressive strength even up to $800^{\circ}C$. On detail microstructural study, it has been found that addition of FA and GBFS in concrete mix improved the density of concrete by development of extra calcium silicate gel before fire and restricts the development of micro-cracks at high temperature as well. In general, the authors are in favour of combined replacement mix in view of high volume mineral by-products utilization as fire protection.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.348-349
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• 2010

기존의 노심설계코드는 UNIX 시스템에 구현되어 있기 때문에 설계자가 입력 생성, 코드 실행, 결과 처리/분석 등의 모든 업무를 텍스트 형태로 작업을 수행해야 한다. 이 방법은 문법 오류 및 실행 오류와 같은 인적 오류를 범할 수 있는 문제가 있다. 본 논문에서는 이 문제를 해결하기 위해서 웹 환경에서 노심설계코드를 자동 실행하기 위한 아키텍처를 제안한다. 제안한 아키텍처는 노심설계코드를 직접 처리하는 CGI 프로그램과 WAS를 연동하여 웹에서 모니터링이 가능하다. 즉, CGI 프로그램은 실시간으로 WAS의 명령을 백그라운드로 실행하고, WAS는 CGI 프로그램의 수행 결과를 웹에서 모니터링 한다. 적용사례로써 제안한 방법으로 원자력발전소의 노심설계코드 프로그램을 수행시켜 실효성을 확인한다.

• Parasites, Hosts and Diseases
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• v.30 no.1
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• pp.49-52
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• 1992

After evaluation of presence of nits and/or lice, PARATM aerosol (bioallethrin with piperonyl butoxide) was applied to 97 women and 43 girls, regardless of the results of their infestation, living at 2 separate institutions. Twelve days after the first treatment the second treatment was carried out and the presence of head lice was examined for the evaluation of treatment effect. Among total 140 subjects, 98(70,0%) were nit positive and 85(60.7%) were louse positive. The infestation rates of girls by nit(86.0%) and louse(86.0%) were higher than those of women, nit 62.9% and louse 49.5%(p<0.01). Also the detection rate of lice among nit positive subjects was higher in girls(100%) than in women(78.7%). On the second evaluation 12 days after treatment, 36(97.3%) out of 37 girls and 46(95.8%) out of 48 women were found louse-free. There was no difference in the treatment efficacy between the women and girls.