Hao Cheng, Guangsheng Du^*, Meng Zhang, Kun Wang, Wenbin Bai

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.4, pp. 685-698, 2020, DOI:10.32604/fdmp.2020.09673 - 11 August 2020

Abstract The determination of the circulation for wind turbine blades is an important problem in engineering. In the present study, we develop a specific approach to evaluate the integral that represents mathematically the circulation. First the potentialities of the method are assessed using a two-dimensional NACA64_A17 airfoil as a testbed and evaluating the influence of different integration paths and angles of attack on the circulation value. Then the method is applied to blades with different relative heights in order to provide useful reference data to be used for the optimization and reverse design of wind turbine More >

Ilze Beverte^1,*, Vairis Shtrauss¹, Aldis Kalpinsh¹, Uldis Lomanovskis¹, Ugis Cabulis², Irina Sevastyanova², Sergejs Gaidukovs³

Journal of Renewable Materials, Vol.8, No.9, pp. 1151-1170, 2020, DOI:10.32604/jrm.2020.010215 - 03 August 2020

Abstract Early investigations of dielectric permittivity of rigid polyurethane foams at low frequencies were made on petrochemical-origin foams, mainly by means of parallel plate capacitors. In the present investigation biopolyol was synthesized from Latvia-grown rapeseeds’ oil by the transesterification method with triethanolamine, in an environmentally friendly process, without emission of harmful substances, at temperatures 175°C ± 5°C. Rigid, closed-cell rapeseed oil polyol polyurethane biofoams and petrochemical foams were made ensuring content of the renewable rapeseed oil polyol in ready foams 27 wt.%–29 wt.%. Dielectric permittivity of the polyurethane foams and the underlying monolithic petrochemical-origin polyurethane and… More >

Beatrise Sture^1,*, Mikelis Kirpluks¹, Sergejs Gaidukovs², Edgars Vanags¹

Journal of Renewable Materials, Vol.8, No.9, pp. 1077-1089, 2020, DOI:10.32604/jrm.2020.09294 - 03 August 2020

Abstract Photocurable systems are more effective, faster and require less energy than conventional thermal curing methods. To facilitate the ongoing transition toward a biobased economy, photoactive compounds were synthesized from tall oil fatty acids (TOFA) which is a by-product from wood pulping. In this study, photoactive monomers were synthesized by two different chemical pathways using oleic acid and TOFA as raw materials. Firstly, double bonds present in TOFA were epoxidized, followed by epoxy ring-opening with acrylic acid which introduced photoactive functional groups into the fatty acid backbone. Intermediates and final products were analysed using titration methods More >

Abdelraheem M. Aly^{1, 2, *}, Mitsuteru Asai³, Ehab Mahmoud Mohamed^{4, 5}

CMC-Computers, Materials & Continua, Vol.65, No.1, pp. 205-224, 2020, DOI:10.32604/cmc.2020.09227 - 23 July 2020

Abstract In the present work, an incompressible smoothed particle hydrodynamic (SPH) method is introduced to simulate water-soil-structure interactions. In the current calculation, the water is modelled as a Newtonian fluid. The soil is modelled in two different cases. In the first case, the granular material is considered as a fluid where a Bingham type constitutive model is proposed based on Mohr-Coulomb yield-stress criterion, and the viscosity is derived from the cohesion and friction angle. In addition, the fictitious suspension layers between water and soil depending on the concentration of soil are introduced. In the second case,… More >

Isamar Rosa¹, Henning Roedel¹, Maria I. Allende¹, Michael D. Lepech^1,*, David J. Loftus²

Journal of Renewable Materials, Vol.8, No.8, pp. 845-861, 2020, DOI:10.32604/jrm.2020.09844 - 10 July 2020

Abstract Biopolymer-bound Soil Composites (BSC), are a novel bio-based construction material class, produced through the mixture and desiccation of biopolymers with inorganic aggregates with applications in soil stabilization, brick creation and in situ construction on Earth and space. This paper introduces a mixture design methodology to produce maximum strength for a given soil-biopolymer combination. Twenty protein and sand mix designs were investigated, with varying amounts of biopolymer solution and compaction regimes during manufacture. The ultimate compressive strength, density, and shrinkage of BSC samples are reported. It is observed that the compressive strength of BSC materials increases proportional More >

Alhan Sariyev¹, Celaleddin Barutcular^2,*, Mert Acar¹, Akbar Hossain³, Ayman EL Sabagh^2,4,5,*

Phyton-International Journal of Experimental Botany, Vol.89, No.3, pp. 519-528, 2020, DOI:10.32604/phyton.2020.09142 - 22 June 2020

Abstract Maize being sub-tropical crop is sensitive to water deficit during the early growth stages; particularly clay-rich soil, due to the compaction of the soil. It is well-documented that potential sub-surface drip irrigation (SDI) (Full irrigation; SDIFull (100% field capacity (FC)), Deficit irrigation; SDIDeficit (70% FC)) improves water use efficiency, which leads to increased crop productivity; since it has a constraint that SDI excludes soil air around the root-zone during irrigation events, which alter the root function and crop performance. Additionally, in clayrich soils, the root system of plants generally suffers the limitation of oxygen, particularly… More >

Shihao Fan, Mingliang Chang^*, Shouxi Wang, Qing Quan, Yong Wang, Dan Li

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 45-59, 2020, DOI:10.32604/cmes.2020.08973 - 19 June 2020

Abstract It is important to determine the insulation thickness in the design of the buried hot oil pipelines. The economic thickness of the insulation layer not only meets the needs of the project but also maximizes the investment and environmental benefits. However, as a significant evaluation, the environmental factors haven’t been considered in the previous study. Considering this factor, the mathematical model of economic insulation thickness of the buried hot oil pipelines is built in this paper, which is solved by the golden section method while considering the costs of investment, operation, environment, the time value… 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 - 01 June 2020

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… More >

Ganggang Hou¹, Tongjing Liu^{1, *}, Xinyu Yuan¹, Jirui Hou¹, Pengxiang Diwu²

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1223-1246, 2020, DOI:10.32604/cmes.2020.09008 - 28 May 2020

Abstract CO₂ flooding has been widely studied and applied to improve oil recovery from low permeability reservoirs. Both the experimental results and the oilfield production data indicate that produced oil components (POC) will vary during CO₂ flooding in low permeability reservoirs. However, the present researches fail to explain the variation reason and rule. In this study, the physical model of the POC variation during CO₂ flooding in low permeability reservoir was established, and the variation reason and rule were defined. To verify the correctness of the physical model, the interaction rule of the oil-CO₂ system was studied by… More >

HAIFENG WANG^1,2,*, JUAN GUO¹, LIJING ZHENG¹, SHUYING LIU¹, ZHERONG WANG¹, HONGXUAN HE²

BIOCELL, Vol.44, No.2, pp. 217-224, 2020, DOI:10.32604/biocell.2020.09051 - 27 May 2020

Abstract The Escherichia coli (E. coli) is prevailing worldwide, but the epidemiology of E. coli infections feature regional distribution characteristics to some extent. E. coli, as a zoonotic pathogen, can be transferred from animals to humans through food chain or via contact with wounds, causing a public health risk. We reported the swelling of proventriculus and tracheal bleeding following the death in two broiler chickens (Gallus gallus domesticus) from Beijing, China. To investigate whether a virus was involved in the infection, Madin Darby Bovine Kidney (MDCK) cells were co-cultured with supernatants of proventriculus, trachea and spleen homogenates. The avian leucosis virus… More >