Ali Safari Variani¹, Masoumeh Ghorbanide¹, Sajad Zare², Saeid Ahmadi^1,*, Zahra Hashemi³

Sound & Vibration, Vol.55, No.1, pp. 31-41, 2021, DOI:10.32604/sv.2021.08930

Abstract Acoustic performance of dissipative silencer was evaluated to determine the effectiveness of perforated duct porosity and absorbent material density in reducing occupational noise exposure propagated from centrifugal fan. Design charts were applied to predict noise reduction and length of a dissipative silencer. Dissipative silencers with various punched duct porosity (14%, 30% and 40%) and sound absorbent density (80 Kg/m³, 120 Kg/m³, and 140 Kg/m³) were designed and fabricated. According to ISO9612 and ISO11820, noise level was measured before and after installing all nine test silencers at fixed workstations around the discharge side of a centrifugal fan in a manufacturing plant.… More >

Dzun Noraini Jimat^*, Sharifah Shahira Syed Putra, Parveen Jamal, Wan Mohd Fazli Wan Nawawi, Mohammed Saedi Jami

Journal of Renewable Materials, Vol.8, No.7, pp. 739-757, 2020, DOI:10.32604/jrm.2020.010357

Abstract Increasing usage of foams in various industry sectors had causing serious disposal problems once it reaches the end of its life-cycle. Herein, PVA-MFC foam was prepared by freeze-drying using polyvinyl alcohol (PVA) and microfibrillated cellulose (MFC) as a reinforced material from sugarcane bagasse (SCB). In this study, the PVA-MFC foam was chemically silylated with Y-methacryloxypropyltrimethoxysilane (MPS) and tetraethoxysilane (TEOS). The wetting ability and mechanical strength of the silylated _2,20PVA-MFC foam was greatly enhanced compared with unmodified _2,20PVA-MFC foam. The silane chemicals (MPS and TEOS) had been confirmed grafted on _2,20PVA-MFC foam due to the presence of Si-C and Si-O-C stretching… More >

Jonathan Lacuesta^1,*, Iris Beatriz Vega Erramuspe², Liji Sobhana², Dennis Kronlund³, Jouko Peltonen³, Soledad Gutiérrez¹, Pedro Fardim^2,4

Journal of Renewable Materials, Vol.8, No.3, pp. 275-287, 2020, DOI:10.32604/jrm.2020.08861

Abstract Biobased adsorbents are eco-friendly materials used for water and wastewater treatment and air cleaning. This research work explores the potential use of rice husk chars as a low-cost adsorbent for pollutants from water, such as methylene blue and ethinylestradiol. Rice husk chars are prepared by combustion of rice husks (RH-Char) or pre-treated rice husks (PT-Char). A third char (M-Char) supplied by a local company which uses rice husks as combustion material is also studied. The chars are characterized by field emission scanning electron microscopy (FE-SEM) in conjunction with energy dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), and zeta-potential measurements.… More >

Purnendu, Soumitra Satapathi^*

Journal of Renewable Materials, Vol.5, No.2, pp. 96-102, 2017, DOI:10.7569/JRM.2016.634134

Abstract Graphene-based 3D porous xerogel was designed through molecular self-assembly of graphene oxide on chitosan matrix and its application in removal of different heavy metal ions from wastewater was investigated. The synthesized xerogel was characterized through FTIR, SEM, XRD and BET surface area analysis. Heavy metal ions, including Pb(II), Cd(II), and Hg(II), were removed from wastewater using this graphene-chitosan (GO-Cs) xerogel and the removal efficiency was monitored through inductively coupled plasma mass spectrometry (ICP-MS). The effect of GO-Cs composition and pH on adsorption efficiency as well as the kinetics of adsorption was studied in detail. The study exhibited that this xerogel… More >

Abha Dubey^1*, Anuradha Mishra²

Journal of Renewable Materials, Vol.5, No.1, pp. 54-61, 2017, DOI:10.7569/JRM.2016.634127

Abstract Biosorption effectively removes heavy metal ions by using inexpensive biosorbents. In this study, Portulaca oleracea plant waste biomass was used as environmentally friendly biosorbent for the removal of copper ions from aqueous solution. This article includes the study of the effects of various important parameters on the biosorption process. Maximum biosorption was found to occur under slightly acidic conditions (pH 6). Small particle size, moderate agitation speed, and moderate temperature favor the biosorption process. The Langmuir model was most suitable, showing the biosorption capacity to be 85.470 mg/g. Pseudo-secondorder model best described the kinetics of the biosorption process. Thermodynamic studies… More >

A. Brancati¹, M. H. Aliabadi¹, A. Milazzo²

CMES-Computer Modeling in Engineering & Sciences, Vol.78, No.1, pp. 1-24, 2011, DOI:10.3970/cmes.2011.078.001

Abstract This paper presents an improved adaptive cross approximation (ACA) approach developed in conjunction with the Hierarchical format matrix and the GMRES solver. A novel scheme to generate the cluster tree (based upon preliminary considerations of the prescribed boundary conditions) and an improved ACA algorithm (approximating the system matrix for mixed Robin conditions) are described. The asymptotic smoothness property of a kernel generated by a linear combination of two asymptotic smooth kernels is demonstrated. Numerical results show the new approach to be up to 50% faster than the conventional ACA approach. More >