Samsul Rizal¹, Fizree, H. M.², Chaturbhuj K. Saurabh³, Deepu A. Gopakumar², N. A. Sri Aprilia⁴, D. Hermawan⁵, A. Banerjee⁶, Fazita M. R. M², Haafiz M. K. M.², Abdul Khalil H. P. S.^2,*

Journal of Renewable Materials, Vol.7, No.12, pp. 1269-1278, 2019, DOI:10.32604/jrm.2019.07227

Abstract Oil palm ash (OPA) is an agro-industry waste and it has disposable problems. In the present study, an effort was made for value addition to OPA by incorporating it as a micro-filler in different concentration (0, 10, 20, 30, 40, and 50%) and sizes (100, 200, and 300 mesh size particles) in the epoxy matrix. Prepared micro OPA was having a crystallinity index of 65.4%, high inorganic elements, and smooth surface morphology. Fabricated composites had higher void content as compared to neat epoxy matrix. Mechanical properties of fabricated composites had a maximum value at 30%… More >

Gregory Reimonn¹, Taofeng Lu¹, Neeti Gandhi², Wan-Ting Chen^1,*

Journal of Renewable Materials, Vol.7, No.12, pp. 1251-1268, 2019, DOI:10.32604/jrm.2019.08055

Abstract Microplastic pollution represents a side-effect stemming from a global plastic waste mismanagement problem and includes degraded particles or mass produced plastic particles less than 5 mm in largest dimension. The small nature of microplastics gives this area of pollution different environmental concerns than general plastic waste in the environment. The biological toxicity of particles, their internal components, and their surface level changes all present opportunities for these particles to adversely affect the environment around them. Thus, it is necessary to review the current literature surrounding this topic and identify areas where the study of microplastic More >

Yixiong Yu^*

Sound & Vibration, Vol.53, No.5, pp. 237-243, 2019, DOI:10.32604/sv.2019.07887

Abstract Mining aeroengine operational data and developing fault diagnosis models for aeroengines are to avoid running aeroengines under undesired conditions. Because of the complexity of working environment and faults of aeroengines, it is unavoidable that the monitored parameters vary widely and possess larger noise levels. This paper reports the extrapolation of a diagnosis model for 20 gas path faults of a double-spool turbofan civil aeroengine. By applying support vector machine (SVM) algorithm together with genetic algorithm (GA), the fault diagnosis model is obtained from the training set that was based on the deviations of the monitored More >

J.K. Mohanty¹, A. Adarsh², P.R. Dash¹, K. Parida¹, P.K. Pradhan^1,*

Sound & Vibration, Vol.53, No.5, pp. 223-235, 2019, DOI:10.32604/sv.2019.07737

Abstract Condition monitoring is implementation of the advanced diagnostic techniques to reduce downtime and to increase the efficiency and reliability. The research is for determining the usage of advanced techniques like Vibration analysis, Oil analysis and Thermography to diagnose ensuing problems of the Plant and Machinery at an early stage and plan to take corrective and preventive actions to eliminate the forthcoming breakdown and enhancing the reliability of the system. Nowadays, the most of the industries have adopted the condition monitoring techniques as a part of support system to the basic maintenance strategies. Major condition monitoring… More >

Roohalah Hajizadeh¹, Ali Khavanin^2,*, Mohammad Barmar³, Ahmad Jonidi Jafari⁴, Somayeh Farhang Dehghan⁵

Sound & Vibration, Vol.53, No.5, pp. 207-222, 2019, DOI:10.32604/sv.2019.06523

Abstract Polyurethane foam as the most well-known absorbent materials has a suitable absorption coefficient only within a limited frequency range. The aim of this study was to improve the sound absorption coefficient of flexible polyurethane (PU) foam within the range of various frequencies using clay nanoparticles, polyacrylonitrile nanofibers, and polyvinylidene fluoride nanofibers. The response surface method was used to determine the effect of addition of nanofi- bers of PAN and PVDF, addition of clay nanoparticles, absorbent thickness, and air gap on the sound absorption coefficient of flexible polyurethane foam (PU) across different frequency ranges. The absorption… More >

Cheng Hu^*

Sound & Vibration, Vol.53, No.5, pp. 199-206, 2019, DOI:10.32604/sv.2019.07712

Abstract Taking the complex mechanical systems as the research project, a theoretical multi-degree-of-freedom (MDOF) model was established. Based on the vibration characteristics analysis of this system, a novel method of vibration mitigation was proposed, which can be applied to most of the complex mechanical systems. Through this method, limited grounding stiffness was made use of and added to certain degree of freedom (DOF) discretely. Thus, the root-meansquare (RMS) of the systems amplitude can be reduced to ideal level. The MATLAB code based on this method was attached, which was tested on the theoretical model. Consider that More >

Mahdi Soltanmohammadi¹, Vahid Monfared^2,*

Sound & Vibration, Vol.53, No.5, pp. 177-198, 2019, DOI:10.32604/sv.2019.05811

Abstract Dry-Type Cast Resin Distribution Transformers (CRT) is the secondgeneration of air-cooled distribution transformers where oil is replaced by resin for electrical insulation. CRT transformers may installed indoor adjacent to or near residential areas since they are clean and safe comparing to the conventional transformers. But, as it is obvious, noise discrepancy is intrinsically accompanied with all types of transformers and is inevitable for CRT transformers too. Minimization of noise level caused by such these transformers has biological and ergonomic importance. As it is known the core of transformers is the main source of the noise… More >

Mohd. Ahmed^1,*, Mohamed Hechmi El Ouni¹, Devinder Singh², Nabil Ben Kahla¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 687-786, 2019, DOI:10.32604/cmes.2019.06886

Abstract The paper presents a parametric study on interpolation techniques based postprocessed error estimation in finite element elastic analysis by varying important parameters of recovery, interpolation scheme and type of patch construction. The quality of error estimation with recovery parameters is compared in terms of local and global effectivity of error estimation, rate of error convergence, and adaptively refined meshes. A mesh free moving least square interpolation technique with proven reliability and effectivity is introduced for improving the recovery of finite element solution errors. The post-processed finite element solutions of elastic problems are presented for performance More >

M. R. Hematiyan^1,*, M. Arezou¹, N. Koochak Dezfouli¹, M. Khoshroo¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 661-686, 2019, DOI:10.32604/cmes.2019.08275

Abstract In this paper, some remarks for more efficient analysis of two-dimensional elastostatic problems using the method of fundamental solutions are made. First, the effects of the distance between pseudo and main boundaries on the solution are investigated and by a numerical study a lower bound for the distance of each source point to the main boundary is suggested. In some cases, the resulting system of equations becomes ill-conditioned for which, the truncated singular value decomposition with a criterion based on the accuracy of the imposition of boundary conditions is used. Moreover, a procedure for normalizing More >

Xiaohua Zhu^1,*, Li Zeng¹, Bo Li¹

CMES-Computer Modeling in Engineering & Sciences, Vol.121, No.2, pp. 631-660, 2019, DOI:10.32604/cmes.2019.06755

Abstract The complicated geological conditions will bring great challenges to the drillstring of horizontal wells for the reason that the increase of the well depth in SichuanChongqing region. Since drillstring failure and friction during drilling are generally caused by drillstring vibration, great importance must be attached to computer simulation methods for the prediction of drillstring vibration. A finite element model considering axial, lateral and torsional vibration is established. In order to verify the established numerical model, an indoor experimental device based on the similarity principle was established. The vibration characteristics of three shale gas horizontal wells… More >