The Experts below are selected from a list of 11874 Experts worldwide ranked by ideXlab platform
Yolanda Pico - One of the best experts on this subject based on the ideXlab platform.
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beeswax cleaning by solvent extraction of pesticides
MethodsX, 2019Co-Authors: Pau Calatayudvernich, Dennis Vanengelsdorp, Yolanda PicoAbstract:Abstract We set out to test if the methodology used to clean Sheep Wool wax (Lanolin) from pesticides could be used to clean beeswax as well. We first made an aggregate sample of brood comb wax from three different US beekeepers. Sub-samples of these aggregate wax samples were analyzed for pesticide contamination. The remaining wax, was then dissolved into hexane solution and run through four N, N-Dimethylformamide (DMF) washes. During these extractions, the pesticides partitioned into the DMF, and so were removed from the beeswax. Following the solvent extractions, the beeswax was tested again for pesticides. An average of 95% of the pesticide contamination was removed by the chemical wash procedure. • Beeswax is the beekeeping matrix with the highest pesticide content. • This study developed methodology for solvent-based removal of pesticides from beeswax (>95%). • Of 24 pesticides detected in beeswax samples before to the solvent extraction, only 3 pesticides were detected after the extraction with DMF.
Gino Iannace - One of the best experts on this subject based on the ideXlab platform.
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predicting the sound absorption of natural materials best fit inverse laws for the acoustic impedance and the propagation constant
Applied Acoustics, 2017Co-Authors: Umberto Berardi, Gino IannaceAbstract:Abstract Natural materials are becoming a valid option for sound absorption treatments. In particular, among them, natural fibers have received increasing attention given their good thermal insulation properties, lack of harmful effects on health, and availability in large quantities. This paper discusses an inverse method to predict the acoustical properties of nine natural fibers. Six vegetative fibers: kenaf, wood, hemp, coconut, straw, and cane; one animal fiber, Sheep Wool; recycled cardboard; and granular cork are investigated. The absorption coefficient and the flow resistance for samples of different thickness have been measured. Moving from the Delany-Bazley model, this study compares the impedance tube results with the theoretically predicted ones. Then, using a least-square fit procedure based on the Nelder-Mead method, the coefficients that best predict both the acoustic impedance and the propagation constant laws are calculated. The inverse approach used in this paper allows to determine different physical parameters and to obtain formulas to include the investigated natural fibers in software modelling for room acoustics applications.
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acoustic characterization of natural fibers for sound absorption applications
Building and Environment, 2015Co-Authors: Umberto Berardi, Gino IannaceAbstract:Abstract Natural materials are becoming a valid alternative to traditional synthetic ones for sound absorption treatments. In particular, in recent years, natural fibers have been considered valid raw materials for producing sound absorbing panels at a reduced cost. Moreover, these fibers often have good thermal insulation properties, have no harmful effects on health, and are available in large quantities often as a waste product of other production cycles. Following a literature review of previous studies about the acoustic properties of some natural materials, this paper reports the acoustical characterization of the following natural fibers: kenaf, wood, hemp, coconut, cork, cane, cardboard, and Sheep Wool. The absorption coefficient and the flow resistance for samples of different thickness have been measured. By using existing theoretical models, this study also compares the measured behavior with the theoretically predicted behavior. This comparison shows the limits of theoretical models originally defined for porous materials with homogeneous fibers, when they are applied to natural materials. Finally, some suggestions for use of these natural fibers for sound absorption applications in buildings are reported.
Abdulaziz Alaskar - One of the best experts on this subject based on the ideXlab platform.
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utilization of Sheep Wool as potential fibrous materials in the production of concrete composites
Journal of building engineering, 2020Co-Authors: Rayed Alyousef, Hisham Alabduljabbar, Hossein Mohammadhosseini, Abdeliazim Mustafa Mohamed, Ayesha Siddika, Fahed Alrshoudi, Abdulaziz AlaskarAbstract:Abstract Proficient and proper management of different types of waste materials is one of the major concerns to ensure a clean environment. The utilization of wastes in the production of concrete has attracted much attention in recent years because of the low-cost of waste materials along with saving a significant place for landfill purposes and also enhance the performance of concrete. In this study, the possibility of Sheep Wool fibers (SWF) and modified Sheep Wool fibers (MSWF) in the production of fiber-reinforced concrete was investigated by assessing the mechanical and microstructural properties. Eight concrete mixes containing 0–6% normal Wool Sheep fibers with a length of 70 mm were made. Further, four concrete mixes with the modified Wool Sheep fibers of 0–1.5% with the same length were made. The addition of both SWF and MSWF reduced the slump values of fresh concrete. The inclusion of Sheep Wool fibers to concrete mixes decreased the compressive strength. However, the addition of Sheep Wool fibers subsequently improved the tensile and flexural strength values of concrete, thereby improving the concrete ductility with higher energy absorption capacity. The microstructural characteristics of Sheep Wool fiber reinforced concrete were conformed to have good bonding and low voids. The findings of the study revealed that the addition of Sheep Wool fibers in the production of concrete is viable both technically and environmentally.
Umberto Berardi - One of the best experts on this subject based on the ideXlab platform.
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predicting the sound absorption of natural materials best fit inverse laws for the acoustic impedance and the propagation constant
Applied Acoustics, 2017Co-Authors: Umberto Berardi, Gino IannaceAbstract:Abstract Natural materials are becoming a valid option for sound absorption treatments. In particular, among them, natural fibers have received increasing attention given their good thermal insulation properties, lack of harmful effects on health, and availability in large quantities. This paper discusses an inverse method to predict the acoustical properties of nine natural fibers. Six vegetative fibers: kenaf, wood, hemp, coconut, straw, and cane; one animal fiber, Sheep Wool; recycled cardboard; and granular cork are investigated. The absorption coefficient and the flow resistance for samples of different thickness have been measured. Moving from the Delany-Bazley model, this study compares the impedance tube results with the theoretically predicted ones. Then, using a least-square fit procedure based on the Nelder-Mead method, the coefficients that best predict both the acoustic impedance and the propagation constant laws are calculated. The inverse approach used in this paper allows to determine different physical parameters and to obtain formulas to include the investigated natural fibers in software modelling for room acoustics applications.
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acoustic characterization of natural fibers for sound absorption applications
Building and Environment, 2015Co-Authors: Umberto Berardi, Gino IannaceAbstract:Abstract Natural materials are becoming a valid alternative to traditional synthetic ones for sound absorption treatments. In particular, in recent years, natural fibers have been considered valid raw materials for producing sound absorbing panels at a reduced cost. Moreover, these fibers often have good thermal insulation properties, have no harmful effects on health, and are available in large quantities often as a waste product of other production cycles. Following a literature review of previous studies about the acoustic properties of some natural materials, this paper reports the acoustical characterization of the following natural fibers: kenaf, wood, hemp, coconut, cork, cane, cardboard, and Sheep Wool. The absorption coefficient and the flow resistance for samples of different thickness have been measured. By using existing theoretical models, this study also compares the measured behavior with the theoretically predicted behavior. This comparison shows the limits of theoretical models originally defined for porous materials with homogeneous fibers, when they are applied to natural materials. Finally, some suggestions for use of these natural fibers for sound absorption applications in buildings are reported.
Thomas Bednar - One of the best experts on this subject based on the ideXlab platform.
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performance evaluation and research of alternative thermal insulations based on Sheep Wool
Energy and Buildings, 2012Co-Authors: Jiří Zach, Azra Korjenic, Jitka Hroudova, Vít Petranek, Thomas BednarAbstract:Abstract Sustainability and energy efficiency in buildings are currently evaluated not only based upon thermal insulation thickness and heating demand, but also according to primary energy demand, CO2 reductions, and ecological properties of the building materials. These properties are essential for a holistic assessment. To meet the requirements which are increasing in rigor, the demand for ecological building materials is growing dramatically, particularly insulating materials from renewable resources. Ecological insulation materials have been available on the market for a long time; however, conventional materials are still predominantly used. Most builders are unsure whether the alternative materials meet the same performance requirements as conventional building materials and supporting scientific research and publications are difficult to find. In a joint project of the Brno University of Technology and Vienna University of Technology, the thermal insulation from Sheep Wool has been tested under various conditions. The building physics and acoustic properties were specifically tested which are important for durable and undamaged applications. The tests results show that the thermal insulation from Sheep Wool has comparable characteristics with mineral/rock Wool, and in some applications even performs better. Additionally, in comparison to mineral Wool, Sheep Wool is more ecological and has fewer damaging health aspects.