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2022 ◽  
Vol 125 ◽  
pp. 107435
Fuchao Zhan ◽  
Mahmoud Youssef ◽  
Bakht Ramin Shah ◽  
Jing Li ◽  
Bin Li

2022 ◽  
Lina Jin ◽  
Li Yang ◽  
Shujuan Zhao ◽  
Zhengtao Wang

Abstract BackgroundBear bile powder is a precious natural material characterized by high content of tauroursodeoxycholic acid (TUDCA) at a ratio of 1.00–1.50 to taurochenodeoxycholic acid (TCDCA).ResultsIn this study, we use the crude enzymes from engineered Saccharomyces cerevisiae to directional convert TCDCA from chicken bile powder to TUDCA at the committed ratio in vitro. This S. cerevisiae strain was modified with heterologous 7α-hydroxysteroid dehydrogenase (7α-HSDH) and 7β-hydroxysteroid dehydrogenase (7β-HSDH) genes. S. cerevisiae host and HSDH gene combinatorial optimization and response surface methodology was applied to get the best engineered strain and the optimal biotransformation condition, respectively, under which 10.99 ± 0.16 g/L of powder products containing 36.73±6.68 % of TUDCA and 28.22±6.05 % of TCDCA were obtained using 12.00 g/L of chicken bile powder as substrate.ConclusionThis study provides a healthy and environmentally friendly way to produce potential alternative resource for bear bile powder from cheap and readily available chicken bile powder, and also gives a reference for the green manufacturing of other rare and endangered animal-derived valuable resource.

Ana Caroline Da Costa Santos ◽  
Paul Archbold

Fibre-reinforced concrete (FRC) is widely employed in the construction industry, with assorted fibre types being used for different applications. Typically, steel fibres give additional tensile strength to the mixture, while flexible fibres may be used in large sections, such as floor slabs, to control crack width and to improve the handling ability of precast sections. For many reasons, including durability concerns, environmental impact, thermal performance, etc, alternatives to the currently available fibres are being sought. This study examines the potential of using basalt fibres, a mineral and natural material, as reinforcement of concrete sections in comparison to steel fibres and plain concrete mix. Mixes were tested containing 0.5% and 1.0% of basalt fibres measuring 25mm length, 0.5% of the same material with 48mm length and steel fibres measuring 50mm by 0.05%, 0.1%, 0.15% and 0.2% of the concrete volume. For the mechanical performance analysis, the 3-point bending test was led and the fracture energy, Young’s modulus and tensile strength in different moments of the tests were calculated. When compared to the control mixtures and the steel-fibre-reinforced concrete, the mixes containing basalt had a reduction in their elastic modulus, representing a decrease in the concrete brittleness. At the same time, the fracture energy of the mixtures was significantly increased with the basalt fibres in both lengths. Finally, the flexural strength was also higher for the natural fibre reinforced concrete than for the plain concrete and comparable to the results obtained with the addition of steel fibres by 0.15%.

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 338
Paulina Jakubowska ◽  
Grzegorz Borkowski ◽  
Dariusz Brząkalski ◽  
Bogna Sztorch ◽  
Arkadiusz Kloziński ◽  

This paper presents the impact of accelerated aging on selected mechanical and thermal properties of isotactic polypropylene (iPP) composites filled with sedimentary hybrid natural filler-Opoka rock. The filler was used in two forms: an industrial raw material originating as a subsieve fraction natural material, and a rock calcinated at 1000 °C for production of phosphorous sorbents. Fillers were incorporated with constant amount of 5 wt % of the resulting composite, and the material was subjected to accelerated weathering tests with different exposition times. The neat polypropylene and composites with calcium carbonate as a reference filler material were used for comparison. The aim of the research was to determine the possibility of using the Opoka rock as a new hybrid filler for polypropylene, which could be an alternative to the widely used calcium carbonate and silica. The thermal, mechanical, and structural properties were evaluated by means of differential scanning calorimetry (DSC), tensile tests, scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR/ATR) prior to and after accelerated aging. As a result, it was found that the composites of polypropylene with Opoka were characterized by similar or higher functional properties and higher resistance to photodegradation compared to composites with conventional calcium carbonate. The results of measurements of mechanical properties, structural and surface changes, and the carbonyl index as a function of accelerated aging proved that Opoka was an effective ultraviolet (UV) stabilizer, significantly exceeding the reference calcium carbonate in this respect. The new hybrid filler of natural origin in the form of Opoka can therefore be used not only as a typical powder filler, but above all as a UV blocker/stabilizer, thus extending the life of polypropylene composites, especially for outdoor applications.

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 193
Carla I. Martins ◽  
Vitória Gil ◽  
Sara Rocha

This research addresses the importance of pine wood sawdust granulometry on the processing of medium-density polyethylene (MDPE)/wood composites by rotational molding and its effects on the morphological, mechanical and aesthetical properties of parts, aiming to contribute for the development of sustainable wood polymer composites (WPC) for rotational molding applications. Pine wood sawdust was sieved (<150, 150, 300, 500, 710, >1000 µm) and analyzed for its physical, morphological and thermal characteristics. Rotational molded parts were produced with matrix/wood ratios from 90/10 to 70/30 wt% considering different wood granulometries. As a natural material, wood changed its color during processing. Granulometries below 500 µm presented better sintering, homogeneity and less part defects. Furthermore, 300–500 µm favored the impact resistance (1316 N), as irregular brick-shaped wood was able to anchor to PE despite the weak interfacial adhesion observed. The increase of wood content from 10 to 30% reduced the impact properties by 40%, as a result of a highly porous structure formed, revealing sintering difficulties during processing. WPC parts of differentiated aesthetics and functionalities were achieved by rotational molding. A clear relationship between wood granulometry and WPC processing, structure and properties was identified.

2022 ◽  
Vol 2160 (1) ◽  
pp. 012021
Jing Liu ◽  
Xiaobin Han ◽  
Yulong Peng ◽  
Xiaoyan Wang ◽  
Runmeng Qiao ◽  

Abstract Diatomite is a kind of natural material with adsorption capacity and it’s widely used in industry. The main purpose of this paper is to study the influence of hydrochloric acid concentration and modification time on the modification effect of diatomite. This article describes a modified method of diatomite, which can not only reduce the purification cost, but also improve the separation efficiency of solanesol. The results show that when the concentration of hydrochloric acid is 3mol/L and the treatment time is 50 minutes, the modification effect of diatomite is the best. The determination of the optimum technological conditions is conducive to the separation and purification of Solanesol by diatomite, and lays a foundation for the further development and utilization of diatomite.

2022 ◽  
Vol 9 (1) ◽  
Caiping Xu ◽  
Zhenbo Liu ◽  
Xingyun Li ◽  
Wanli Li

Wood is the main material used for musical instrument soundboard fabrication, for practical and cultural reasons. As a natural material, however, wood is easily degraded due to moisture or fungal corrosion. Most traditional wood protection methods were devised for structural materials, and may thus not be suitable for application in musical instrument soundboard materials. In the current study, a novel nanomaterial-based modification method was applied to wood. The surface of wood was coated with polyurethane and MgAl-layered double hydroxide nanosheets after a convenient impregnation process. The modified wood exhibited improved hydrophobicity and mould-resistance, while maintaining its acoustic properties. This modified wood may facilitate the construction of soundboards with longer lifespans.

2022 ◽  
Vol 961 (1) ◽  
pp. 012004
Haneen Mohammed Ali ◽  
Ressol R Shakir

Abstract Soil is a natural material that suffers from intrinsic spatial variability resulting from natural factors and their influence on the soil. It became controversial and debated how to estimate the characteristic value of soils to obtain a reliable geotechnical design with low cost and less effort. Usually, foundations are not built on the same site as the screening; investigations are carried out to excavate a little at essential sites. In this paper (423), test wells were collected in the study area to be obtained and tabulated in Excel. The kriging statistics is applied using a python script to predict the values of geotechnical site properties and reliability of the method in estimating spatially varying soil properties values based on measurement data and prior knowledge. The program implements probabilistic kriging statistics and predicts the desired value by entering the coordinates of the locations whose properties you want to know and based on the previously prepared Excel file of known points, coordinates, and property values. The program will be used in two soil sites in the city of Nasiriyah to predict its properties. These points were selected from the examination of soil investigation reports to determine the reliability and accuracy of the program in predicting values. To get more reliable probability values using the kriging method and python scripts. A huge database of prepared and analyzed engineering soil properties has been created based on field investigation reports for projects in Nasiriyah.

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 134
Claudia Sergi ◽  
Fabrizio Sarasini ◽  
Jacopo Tirillò

Cork, a natural material from renewable resources, is currently attracting increasing interest in different industrial fields because of its cellular structure and the presence of the flexible suberin as its main chemical component. In an agglomerated form, it proved to be a compelling product not only as a thermal and acoustic insulator, but also as core material in sandwich structures and as a liner or padding in energy absorbing equipment. From this perspective, the assessment of its compressive response is fundamental to ensure the right out-of-plane stiffness required to a core material and the proper crashworthiness in the safety devices. Considering the complex nature of cork and the resulting peculiar compressive response, the present review article provides an overview of this paramount property, assessing the main parameters (anisotropy, temperature, strain rate, etc.) and the peculiar features (near-zero Poisson’s ratio and unique dimensional recovery) that characterize it in its natural state. Furthermore, considering its massive exploitation in the agglomerated form, the design parameters that allow its compressive behavior to be tailored and the operating parameters that can affect its crashworthiness were assessed, reporting some potential industrial applications.

Khalid Hamid ◽  
Abdelmoneim Massad Abdalla

This study conducted to substituting of NaOH used as a neutralizing agent for acidic wastewater generated from manufacturing of TNT in factory of Sudanese Military industries by natural material such as Neem leaves powder. The requirement for pH values of astewater to be disposed over 6. Four weights (5 , 7.5, 10 and 12.5 ) g of dry Neem leaves powder prepared and added to four samples of acidic wastewater with volume of 100 ml for each samples, the pH values of wastewater measured after four periods (1 ,2,3 and 4) hr for each weight added. The results showed the pH values raised from 1.7 to 6.94 and no any residual salts observed. The Neem leaves powder is effective alternatives for sodium hydroxide to neutralizing acidic wastewater at TNT plant.

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