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Poly(Butylene Adipate-Co-Terephthalate)and Poly(ε-Caprolactone)and Their Bionanocomposites with Cellulose Nanocrystals:Thermo-Mechanical Properties and Cell Viability Study
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作者 Marcia Cristina Branciforti Caroline Faria Bellani +3 位作者 Carolina Lipparelli Morelli Alice Ferrand Nadia Benkirane-Jessel Rosario Elida Suman Bretas 《Journal of Renewable Materials》 SCIE 2019年第3期269-277,共9页
Although nanocomposites have recently attracted special interest in the tissue engineering area,due to their potential to reinforce scaffolds for hard tissues applications,a number of variables must be set prior to an... Although nanocomposites have recently attracted special interest in the tissue engineering area,due to their potential to reinforce scaffolds for hard tissues applications,a number of variables must be set prior to any clinical application.This manuscript addresses the evaluation of thermo-mechanical properties and of cell proliferation of cellulose nanocrystals(CNC),poly(butylene adipate-co-terephthalate)(PBAT),poly(ε-caprolactone)(PCL)films and their bionanocomposites with 2 wt% of CNC obtained by casting technique.Cellulose nanocrystals extracted from Balsa wood by acid hydrolysis were used as a reinforcing phase in PBAT and PCL matrix films.The films and pure CNC at different concentrations were cultured with osteoblasts MG-63 and the cell proliferation was assessed by AlamarBlue?assay.The thermal-mechanical properties of the films were evaluated by dynamic-mechanical thermal analysis(DMTA).It was found by DMTA that the CNC acted as reinforcing agent.The addition of CNCs in the PBAT and PCL matrices induced higher storage moduli due to the reinforcement effects of CNCs.The cell viability results showed that neat CNC favored osteoblast proliferation and both PBAT and PCL films incorporated with CNC were biocompatible and supported cell proliferation along time.The nature of the polymeric matrix or the presence of CNC practically did not affect the cell proliferation,confirming they have no in vitro toxicity.Such features make cellulose nanocrystals a suitable candidate for the reinforcement of biodegradable scaffolds for tissue engineering and biomedical applications. 展开更多
关键词 Cell viability thermo-mechanical properties cellulose nanocrystals(CNC) biocompatible polymers tissue engineering BIONANOCOMPOSITES
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Effect of thermo-mechanical properties of PIM feedstock on compacts shape retention during debinding process 被引量:1
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作者 K.A.Khalil 黄伯云 李益民 《中国有色金属学会会刊:英文版》 CSCD 2001年第4期521-524,共4页
The removal of the binder from the powder compacts (debinding) can be a slow step and a source of problems. To improve the debinding process of powder injection molding operation, it’s necessary to understand the the... The removal of the binder from the powder compacts (debinding) can be a slow step and a source of problems. To improve the debinding process of powder injection molding operation, it’s necessary to understand the thermal and mechanical properties of powder injection molding feedstocks and to find the major causes responsible for molding difficulties and compacts shape retention during debinding process. The effects of thermo mechanical properties of the PIM feedstock on the compacts shape retention during debinding process were discussed and explained from practical point of view. The results indicate that the heat of fusion affects the cooling time. The binder component with high heat of fusion and high decomposed temperature is more effective as the second binder component for the compact to retain its shape during debinding. 展开更多
关键词 thermo mechanical properties shape retention DEBINDING thermal stresses
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Thermo-mechanical Properties of Al/Si Incorporated Low Carbon Al_2O_3-C Slide Plate Materials 被引量:1
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作者 LIU Xinhong ZHONG Xiangchong 《China's Refractories》 CAS 2013年第1期7-11,共5页
Low carbon Al2O3- C refractory materials were prepared by "Al/Si metal incorporated, insitu formed non-oxides" method using corundum, Al powder, Si powder and flake graphite as starting materials. High temperature s... Low carbon Al2O3- C refractory materials were prepared by "Al/Si metal incorporated, insitu formed non-oxides" method using corundum, Al powder, Si powder and flake graphite as starting materials. High temperature strength, stress -strain relationship and thermal shock resistance of these composites were investigated. The results show that these composites possess improved high temperature strength and good thermal shock resistance. When A1 addition increases from 0 to 8 mass%, correspondingly, Si addition decreases from 8 mass% to O, hot modulus of rupture at 1 400 ℃ increases significantly from 10. 4 MPa to 32. 4 MPa; the maximum strain under 6.5 MPa stress at 1400 ℃ decreases from 215 t.tm to 90 μm; residual strength ratio after 3 thermal shock cycles (1 100 ℃ , air quenching) decreases from 80% to 65%. This may be attributed to in-situ formation of nonoxides because Al and Si react with C, CO and N, to form Al4C3 , AlN and SiC creating strengthening and toughening effects. 展开更多
关键词 thermo-meehanieal properties aluminum/ silicon incorporation oxidenonoxide refractory materials
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Adding Hydrated Lime in a Material Made of Clayey Soil and Fibres: Formulation and Effects on Thermo-Mechanical Properties
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作者 Fati Zoma Fabien H. Yonli +2 位作者 Etienne Malbila David Y. K. Toguyeni Ivon B. Hassel 《Journal of Minerals and Materials Characterization and Engineering》 2020年第3期149-161,共13页
In this study, we have focused our investigations on effect of adding hydrated lime on a locally made composite material, based on clayey earth (soil) and Hibiscus sabdariffa fibres, for envelope (walls) in the buildi... In this study, we have focused our investigations on effect of adding hydrated lime on a locally made composite material, based on clayey earth (soil) and Hibiscus sabdariffa fibres, for envelope (walls) in the building. Prior to sample’s formulation, we selected an appropriate mineral (soil) material based on criteria as: plasticizer power for good workability, dense coarse particles to withstand loads and finally porous structure to take advantage of air insulating character. We then formulated, following a mixing process by shearing and compaction by vibration that we recommend, two composite materials (A), (B) which contain respectively 1% Fibres plus 1% lime, 1% Fibres plus 3% lime. We determined thermal properties by the mean of KD2 Pro thermal analyzer, compression strength accordingly to the standard NF P 18-406, porosity following volumetric and gravimetric methods and pH of soil-hydrated lime solution. As results, up to 5% of hydrated lime, the measured pH is inferior to 12: mineralization of vegetal fibres is highly unlikely. Moreover, we observe that the addition of hydrated lime resulted in a reduction in the number of cracks and their depths;Samples (A) and (B) have a rather compact appearance than the case 1% Fibres without lime (material (C)). Furthermore, with lime stabilization, the insulating potential is improved while the thermal inertia has been deteriorated compared to material (C). However, compressive strength decreases with lime, which could be due to the presence of fibres that would inhibit the hardening of the lime. At last, with 3.39% ± 3.07% MPa, 2.27% ± 11.30% MPa for samples (A), (B) respectively, the minimum required by CRATerre-EAG (guide of CDI, 1996) for construction of envelope (walls) of single storey (ground floor) buildings is met. 展开更多
关键词 Local MATERIAL Hydrated LIME HIBISCUS sabdariffa Fibre thermo-mechanical properties POROSITY
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Thermo-mechanical Properties of In-situ Formed Al_2O_3-SiC-SiAION Composites
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作者 HUANG Yalei GU Qiang +2 位作者 WEN Yubin LIU Zhifang LIU Xinhong 《China's Refractories》 CAS 2016年第2期48-52,共5页
Al2 O3 - SiC - SiAION composite specimens have been prepared using fused alumina, ultra fine α-Al2O3, Si and Al powders as starting materials and liquid phenol formaldehyde resin as binder and firing at 1 500 ℃ for ... Al2 O3 - SiC - SiAION composite specimens have been prepared using fused alumina, ultra fine α-Al2O3, Si and Al powders as starting materials and liquid phenol formaldehyde resin as binder and firing at 1 500 ℃ for 3 h in carbon embedded condition. Thermo-mechanical properties of Al2 O3 - SiC - SiAlON composites have been studied. The results show : ( 1 ) Al2 O3 - SiC - SiAION composites can be prepared and sintered at 1 500 ℃ under carbon embedded condition. When Si/Al ratio is 8/0 and 7/1, the prepared composite is Al2O3 - SiC - O' -SiAlON; when Si/Al ratio is 5/3 and 3/5, the pre- pared composite is Al2 O3 - SiC - β-SiAION. ( 2 ) The composites possess high temperature strength properties. Hot modulus of rupture at 1 400 ℃ is 10 - 30 MPa. They are in elastic range up to 1 000 ℃, after which plastic deformation is observed; even at 1 400 ℃, amount of deformation is relatively low. (3) The com- posites possess good thermal shock resistance, their resid- ual strength ratio (AT = 1 100 ℃ ) is 65% - 80%. (4) The marked improvement in thermo-mechanical properties of Al2O3 - SiC - SiAlON composites may be at- tributed to the in-situ formation of SiC, SiAlON and AIN, the fibrous SiC, columnar SiAlON and tabular-like AlN fill in the corundum skeleton structure creating strengthening and toughening effects. 展开更多
关键词 alumina - silicon carbide - SiAlON ther-mo-mechanical properties IN-SITU slide plate
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Thermo-mechanical properties of bowl-shaped grinding wheel and machining error compensation for grinding indexable inserts
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作者 张祥雷 姚斌 +3 位作者 陈彬强 孙维方 王萌萌 罗琪 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第10期3830-3836,共7页
In order to meet the technical requirements of grinding the circumferential cutting edge of indexable inserts, thermo-mechanical properties of bowl-shaped grinding wheel in high speed grinding process and the influenc... In order to meet the technical requirements of grinding the circumferential cutting edge of indexable inserts, thermo-mechanical properties of bowl-shaped grinding wheel in high speed grinding process and the influence of dimension variations of the grinding wheel on machining accuracy were investigated. Firstly, the variation trends of the dimension due to centrifugal force generated in different wheel speeds were studied and the effect of stress stiffening and spin softening was presented. Triangular heat flux distribution model was adopted to determine temperature distribution in grinding process. Temperature field cloud pictures were obtained by the finite element software. Then, dimension variation trends of wheel structure were acquired by considering the thermo-mechanical characteristic under combined action of centrifugal force and grinding heat at different speeds. A method of online dynamic monitoring and automatic compensation for dimension error of indexable insert was proposed. By experimental verification, the precision of the inserts satisfies the requirement of processing. 展开更多
关键词 可转位刀片 热机械性能 碗形砂轮 磨削加工 误差补偿 尺寸变化 车轮转速 在线动态监测
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Thermo-mechanical properties of RTM-made carbon fibre/polyimide composite attaching collar under transient heating 被引量:1
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作者 Shengda JIANG Chuyang LUO +3 位作者 Peng ZHANG Jianwen BAO Peipei CAI Xufeng XIA 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2023年第3期393-405,共13页
This study focuses on the thermo-mechanical properties of Carbon Fibre/Polyimide Composite(CFPC)attaching collars under transient heating.The CFPC attaching collars were fabricated by a high-temperature resin transfer... This study focuses on the thermo-mechanical properties of Carbon Fibre/Polyimide Composite(CFPC)attaching collars under transient heating.The CFPC attaching collars were fabricated by a high-temperature resin transfer moulding process,and their thermo-mechanical properties under the conditions of simultaneous transient heating and bending load were investigated.The results show that the attaching collar tends to fail at 118% of the limit load.The failure mode includes the fracture of the connecting screws,local extrusion damage of the hole edges,and slight ablation damage at the outer plies.And there is no observable residual deformation in the composite attaching collar.Furthermore,considering that the material properties vary with temperature,a progressive damage model based on the sequential thermo-mechanical coupling method was established to study the failure mechanism of the attaching collar.Finally,the damage factor of the CFPC was calculated to assess the safety status of the attaching collar.The results show that the primary damage modes of the composite attaching collar are intralaminar failure,which mainly occurs at the heat insulation layer and the hole edges,and these slightly affect the structural bearing capacity.A good correlation between the experiment and FEA is obtained.The test methods and analysis models proposed contribute to the safety assessment of composite structures under transient heating. 展开更多
关键词 Polyimide composites Progressive damage model Resin transfer moulding thermo-mechanical properties Transient heating
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Microstructure and damping properties of LPSO phase dominant Mg-Ni-Y and Mg-Zn-Ni-Y alloys 被引量:1
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作者 Ruopeng Lu Kai Jiao +3 位作者 Nanting Li Hua Hou Jingfeng Wang Yuhong Zhao 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1131-1153,共23页
This work studied the microstructure,mechanical properties and damping properties of Mg_(95.34)Ni_(2)Y_(2.66) and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys systematically.The difference in the evolution of the long-period ... This work studied the microstructure,mechanical properties and damping properties of Mg_(95.34)Ni_(2)Y_(2.66) and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys systematically.The difference in the evolution of the long-period stacked ordered(LPSO)phase in the two alloys during heat treatment was the focus.The morphology of the as-cast Mg_(95.34)Ni_(2)Y_(2.66)presented a disordered network.After heat treatment at 773 K for 2 hours,the eutectic phase was integrated into the matrix,and the LPSO phase maintained the 18R structure.As Zn partially replaced Ni,the crystal grains became rounded in the cast alloy,and lamellar LPSO phases and more solid solution atoms were contained in the matrix after heat treatment of the Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloy.Both Zn and the heat treatment had a significant effect on damping.Obvious dislocation internal friction peaks and grain boundary internal friction peaks were found after temperature-dependent damping of the Mg_(95.34)Ni_(2)Y_(2.66)and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys.After heat treatment,the dislocation peak was significantly increased,especially in the alloy Mg_(95.34)Ni_(2)Y_(2).66.The annealed Mg_(95.34)Ni_(2)Y_(2.66)alloy with a rod-shaped LPSO phase exhibited a good damping performance of 0.14 atε=10^(−3),which was due to the difference between the second phase and solid solution atom content.These factors also affected the dynamic modulus of the alloy.The results of this study will help in further development of high-damping magnesium alloys. 展开更多
关键词 Mg-Ni-Y alloys Mg-Zn-Ni-Y alloys LPSO phase Heat treatment MICROSTRUCTURE Damping properties.
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Hydration Behavior and Cementitious Properties of Calcium Carbonate-aluminate Minerals Composite
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作者 王冲 周帅 +2 位作者 ZOU Luyao LIU Jiawen ZHENG Yalin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期126-133,共8页
The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementi... The purpose of this research is to investigate the hydration behavior and cementitious properties of the mixture of calcium carbonate and aluminate, and to explore whether it can be adopted as a new low-carbon cementitious material. The composite system of calcium carbonate and aluminate minerals is studied by measuring the component of hydration products, the hydration heat, setting time and compressive strength.The results prove that the composite system has certain cementitious properties and is feasible to prepare new low-carbon cement. 展开更多
关键词 LIMESTONE hydrated calcium carboaluminate cementitious properties mechanical properties
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Influences of divalent ion substitution on the magnetic and dielectric properties of W-type barium ferrite
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作者 何诗悦 刘若水 +3 位作者 刘煦婕 叶先平 王利晨 沈保根 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期480-486,共7页
Saturation magnetization,magneto-crystalline anisotropy field,and dielectric properties are closely related to microwave devices applied at different frequencies.For regulating the magnetic and dielectric properties o... Saturation magnetization,magneto-crystalline anisotropy field,and dielectric properties are closely related to microwave devices applied at different frequencies.For regulating the magnetic and dielectric properties of W-type barium ferrites,single-phase BaMe_(2)Fe_(16)O_(27)(Me=Fe,Mn,Zn,Ni,Co) with different Me ions were synthesized by the high-temperature solid-state method.The saturation magnetization(Ms) range from 47.77 emu/g to 95.34 emu/g and the magnetic anisotropy field(H_a) range from 10700.60 Oe(1 Oe=79.5775 A·m^(-1)) to 13739.57 Oe,depending on the type of cation substitution in the hexagonal lattice.The dielectric permittivity and dielectric loss decrease with increasing frequency of the AC electric field in the low-frequency region,while they almost remain constant in the high-frequency region.The charac teristics of easy regulation and preparation make it a potential candidate for use in microwave device applications. 展开更多
关键词 W-type hexaferrite Raman spectra magnetic properties dielectric properties
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A review on the multi-scaled structures and mechanical/thermal properties of tool steels fabricated by laser powder bed fusion additive manufacturing
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作者 Huajing Zong Nan Kang +1 位作者 Zehao Qin Mohamed El Mansori 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期1048-1071,共24页
The laser powder bed fusion(LPBF) process can integrally form geometrically complex and high-performance metallic parts that have attracted much interest,especially in the molds industry.The appearance of the LPBF mak... The laser powder bed fusion(LPBF) process can integrally form geometrically complex and high-performance metallic parts that have attracted much interest,especially in the molds industry.The appearance of the LPBF makes it possible to design and produce complex conformal cooling channel systems in molds.Thus,LPBF-processed tool steels have attracted more and more attention.The complex thermal history in the LPBF process makes the microstructural characteristics and properties different from those of conventional manufactured tool steels.This paper provides an overview of LPBF-processed tool steels by describing the physical phenomena,the microstructural characteristics,and the mechanical/thermal properties,including tensile properties,wear resistance,and thermal properties.The microstructural characteristics are presented through a multiscale perspective,ranging from densification,meso-structure,microstructure,substructure in grains,to nanoprecipitates.Finally,a summary of tool steels and their challenges and outlooks are introduced. 展开更多
关键词 additive manufacturing laser powder bed fusion tool steel multi-scaled structure mechanical properties thermal properties
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Impact of scandium and terbium on the mechanical properties,corrosion behavior,and biocompatibility of biodegradable Mg-Zn-Zr-Mn alloys
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作者 Khurram Munir Jixing Lin +3 位作者 Xian Tong Arne Biesiekierski Yuncang Li Cuie Wen 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期546-572,共27页
Magnesium(Mg)-based bone implants degrade rapidly in the physiological environment of the human body which affects their structural integrity and biocompatibility before adequate bone repair.Rare earth elements(REEs)h... Magnesium(Mg)-based bone implants degrade rapidly in the physiological environment of the human body which affects their structural integrity and biocompatibility before adequate bone repair.Rare earth elements(REEs)have demonstrated their effectiveness in tailoring the corrosion and mechanical behavior of Mg alloys.This study methodically investigated the impacts of scandium(Sc)and terbium(Tb)in tailoring the corrosion resistance,mechanical properties,and biocompatibility of Mg–0.5Zn–0.35Zr–0.15Mn(MZZM)alloys fabricated via casting and hot extrusion.Results indicate that addition of Sc and Tb improved the strength of MZZM alloys via grain size reduction and solid solution strengthening mechanisms.The extruded MZZM–(1–2)Sc–(1–2)Tb(wt.%)alloys exhibit compressive strengths within the range of 336–405 MPa,surpassing the minimum required strength of 200 MPa for bone implants by a significant margin.Potentiodynamic polarization tests revealed low corrosion rates of as–cast MZZM(0.25 mm/y),MZZM–2Tb(0.45 mm/y),MZZM–1Sc–1Tb(0.18 mm/y),and MZZM–1Sc–2Tb(0.64 mm/y),and extruded MZZM(0.17 mm/y),MZZM–1Sc(0.15 mm/y),MZZM-2Sc(0.45 mm/y),MZZM-1Tb(0.17 mm/y),MZZM-2Tb(0.10 mm/y),MZZM–1Sc-1Tb(0.14 mm/y),MZZM-1Sc-2Tb(0.40 mm/y),and MZZM–2Sc–2Tb(0.51 mm/y)alloys,which were found lower compared to corrosion rate of high-purity Mg(~1.0 mm/y)reported in the literature.Furthermore,addition of Sc,or Tb,or Sc and Tb to MZZM alloys did not adversely affect the viability of SaOS2 cells,but enhanced their initial cell attachment,proliferation,and spreading shown via polygonal shapes and filipodia.This study emphasizes the benefits of incorporating Sc and Tb elements in MZZM alloys,as they effectively enhance corrosion resistance,mechanical properties,and biocompatibility simultaneously. 展开更多
关键词 Corrosion property In vitro cytotoxicity Magnesium alloys Mechanical property Rare earth elements
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Physico-Chemical and Nutritional Properties of a Food Broth Based on Nere (Parkia biglobosa)
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作者 Lassana Bamba Gervais Melaine M’Boh +5 位作者 N’Gbésso Amos Ekissi Kipré Laurent Séri Gnogbo Alexis Bahi Koffi Pierre Valery Niaba Allico Joseph Djaman Grah Avit Maxwell Beugre 《Food and Nutrition Sciences》 CAS 2024年第5期377-389,共13页
Purpose: Diet and eating habits are major risk factors for the health and the development of disease, such as, for example, metabolic disorder leading to cardiovascular pathology and cancer, decreased immunity exposin... Purpose: Diet and eating habits are major risk factors for the health and the development of disease, such as, for example, metabolic disorder leading to cardiovascular pathology and cancer, decreased immunity exposing to infections. This study of the physico-chemical and nutritional properties of a soumara-based food broth was carried out with the aim of promoting the consumption of organic broth made from nere seeds (soumara). That is to alleviate certain metabolic diseases, which is a matter of food safety, and also to limit the risk for the health about the consumption of some cooking stocks on the market. Methods: Several natural ingredients such as nere seeds (soumara), ginger, black pepper, parsley and garlic were used to create a nere-based stock. All these ingredients were freeze-dried and the powder obtained was used to make the broth, regarding their physical and chemical properties. Results: The broth had a good protein content of 17.41 ± 0.367 g/100g, a lipid content of 16.80 ± 0.08 g/100g and a fiber content of 8.66 ± 0.04 g/100g. In terms of nutritional values, the broth showed good levels of calcium 184.21 ± 0.09 mg/100g, potassium 50.04 ± 1.45 mg/100g and iron and zinc. In terms of antioxidant activity, the broth also showed good antioxidant activity. Conclusion: Regarding the properties of our food broth, whose composition is based on natural ingredients, could be recommended for consumption and, its properties, could play an important role in preventing and combating certain metabolic diseases. 展开更多
关键词 Food Broth Nere Physico-Chemical properties NUTRITION Food Safety
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Soil Physico-Chemical Properties and Different Altitudes Affect Arbuscular Mycorrhizal Fungi Abundance and Colonization in Cacao Plantations of Cameroon
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作者 Franklin Tounkam Ketchiemo Beaulys Fotso +4 位作者 Astride Stéphanie Mouafi Djabou Victor Jos Eyamo Evina Japhet Youri Essambita Franck Maxime Ewane Tang Nicolas Niemenak 《American Journal of Plant Sciences》 CAS 2024年第2期57-82,共26页
This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-... This study aims to investigate the abundance of AMF according to soil properties and altitudes in different cacao plantations of Cameroon. Physico-chemical analyses were made on soil samples collected from three agro-ecological zones. Soil samples were also used to evaluate directly the AMF abundance following the various altitudes and after trapping by sorghum plant. The results showed that soil properties, AMF spore abundances and colonization fluctuated significantly at different altitudes. The most represented texture was sandy loam. The bimodal zone presented a homogeneous texture (sandy loam) in all its localities. Cacao soil chemical characteristics showed that, the highest nitrogen rate (0.47%;p 0.05, Scott-Knott test) was recorded at Melong in a monomodal zone while Tonga in the Western highlands displayed the lowest rate (0.13%). Soil P concentration was significantly high in monomodal zones (Mbanga and Melong). Soil pH level indicated that the soil from Tonga in the Western highlands was neutral (pH = 6.67), and soils of other localities under study were acidic with the lowest (4.75) pH level recorded at Melong in a monomodal zone. In soil samples, the highest spore density (1.03 spores/g soil) was observed at Ntui in Bimodal zone, while the lowest spore density (0.26 spores/g soil) was observed at Bafang in the Western highlands. Root colonization showed that the sample from Bokito in a bimodal zone displayed the best frequency of mycorrhization (86.11%) while the sample from Bafang in the Western highlands recorded the lowest (27.11%). The PCA analysis highlighted that available phosphorus, pH and altitude all strongly correlated with AMF root colonization ability and can be used as a predictor of AMF colonization ability in cacao rhizosphere. 展开更多
关键词 Agroecological Zone Altitude Variations Arbuscular Mycorrhizal Fungi Soil properties Theobroma cacao
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Synergistic enhancement on mechanical properties and corrosion resistance of biodegradable Mg-Zn-Y alloy via V-microalloying
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作者 Jiaxin Zhang Xin Ding +3 位作者 Ruirun Chen Wenchao Cao Jinshan Zhang Rui Zhao 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期530-545,共16页
For the sake of improving the mechanical properties and corrosion resistance of biodegradable Mg alloy synergistically,various content of element V(0,0.05,0.10,0.15,0.20 wt.%)are introduced into an Mg-Zn-Y alloy with ... For the sake of improving the mechanical properties and corrosion resistance of biodegradable Mg alloy synergistically,various content of element V(0,0.05,0.10,0.15,0.20 wt.%)are introduced into an Mg-Zn-Y alloy with long-period stacking ordered(LPSO)structure,and the effects of V on its microstructure,mechanical properties and corrosion resistance are investigated systematically.The results indicate that the grains are effectively refined by V addition,and the primaryα-Mg in Mg-Zn-Y-V0.1 alloy is most significantly refined,with grain size being decreased by 62%.The amount of 18R LPSO structure is increased owing to the V addition.The growth mode of the second phase(W-phase and 18R LPSO structure)is transformed to divorced growth pattern,which ascribes to the thermodynamic drive force of V to promote the nucleation of LPSO phase.Thus,18R LPSO structure presents a continuous distribution.Due to grains refinement and modification of second phase,the tensile strength and strain of alloys are both enhanced effectively.Especially,the ultimate tensile strength and the elongation of V0.1 alloy are 254 MPa and 15.26%,which are 41%and 61%higher than those of V-free alloy,respectively.Owing to the continuously distributed 18R LPSO structure with refined grains and stable product film,the weight loss and hydrogen evolution corrosion rates of V0.1 alloy are 7.1 and 6.2 mmy^(-1),respectively,which are 42.6%and 45.4%lower than those of V-free alloy. 展开更多
关键词 Corrosion Mechanical property V-microalloying LPSO SKPFM
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A novel high-Cr CoNi-based superalloy with superior high-temperature microstructural stability, oxidation resistance and mechanical properties
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作者 Xiaorui Zhang Min Zou +3 位作者 Song Lu Longfei Li Xiaoli Zhuang Qiang Feng 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第6期1373-1381,共9页
A novel multicomponent high-Cr CoNi-based superalloy with superior comprehensive performance was prepared,and the evaluation of its high-temperature microstructural stability,oxidation resistance,and mechanical proper... A novel multicomponent high-Cr CoNi-based superalloy with superior comprehensive performance was prepared,and the evaluation of its high-temperature microstructural stability,oxidation resistance,and mechanical properties was conducted mainly using its cast polycrystalline alloy.The results disclosed that the morphology of theγ′phase remained stable,and the coarsening rate was slow during the long-term aging at 900–1000℃.The activation energy forγ′precipitate coarsening of alloy 9CoNi-Cr was(402±51)kJ/mol,which is higher compared with those of CMSX-4 and some other Ni-based and Co-based superalloys.Importantly,there was no indica-tion of the formation of topologically close-packed phases during this process.All these factors demonstrated the superior microstructural stability of the alloy.The mass gain of alloy 9CoNi-Cr was 0.6 mg/cm^(2) after oxidation at 1000℃ for 100 h,and the oxidation resistance was comparable to advanced Ni-based superalloys CMSX-4,which can be attributed to the formation of a continuous Al_(2)O_(3) protective layer.Moreover,the compressive yield strength of this cast polycrystalline alloy at high temperatures is clearly higher than that of the conventional Ni-based cast superalloy and the compressive minimum creep rate at 950℃ is comparable to that of the conventional Ni-based cast superalloy,demonstrating the alloy’s good mechanical properties at high temperature.This is partially because high Cr is bene-ficial in improving theγandγ′phase strengths of alloy 9CoNi-Cr. 展开更多
关键词 CoNi-based superalloys microstructure COARSENING OXIDATION mechanical properties
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Microstructures,corrosion behavior and mechanical properties of as-cast Mg-6Zn-2X(Fe/Cu/Ni)alloys for plugging tool applications
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作者 Baosheng Liu Jiali Wei +4 位作者 Shaohua Zhang Yuezhong Zhang Pengpeng Wu Daqing Fang Guorui Ma 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第4期697-711,共15页
Mg-6Zn-2X(Fe/Cu/Ni)alloys were prepared through semi-continuous casting,with the aim of identifying a degradable magnesium(Mg)alloy suitable for use in fracturing balls.A comparative analysis was conducted to assess t... Mg-6Zn-2X(Fe/Cu/Ni)alloys were prepared through semi-continuous casting,with the aim of identifying a degradable magnesium(Mg)alloy suitable for use in fracturing balls.A comparative analysis was conducted to assess the impacts of adding Cu and Ni,which result in finer grains and the formation of galvanic corrosion sites.Scanner electronic microscopy examination revealed that precipitated phases concentrated at grain boundaries,forming a semi-continuous network structure that facilitated corrosion penetration in Mg-6Zn-2Cu and Mg-6Zn-2Ni alloys.Pitting corrosion was observed in Mg-6Zn-2Fe,while galvanic corrosion was identified as the primary mechanism in Mg-6Zn-2Cu and Mg-6Zn-2Ni alloys.Among the tests,the Mg-6Zn-2Ni alloy exhibited the highest corrosion rate(approximately 932.9 mm/a)due to its significant potential difference.Mechanical testing showed that Mg-6Zn-2Ni alloy possessed suitable ultimate compressive strength,making it a potential candidate material for degradable fracturing balls,effectively addressing the challenges of balancing strength and degradation rate in fracturing applications. 展开更多
关键词 magnesium alloys microstructure micro-galvanic corrosion mechanical properties
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Effects of BN on the Mechanical and Thermal Properties of PP/BN Composites
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作者 陈厚振 王艳芝 +4 位作者 NAN Yu WANG Xu YUE Xianyang ZHANG Yifei FAN Huiling 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期345-352,共8页
In order to explore the thermal conductivity of polypropylene(PP)/hexagonal boron nitride(BN) composites,PP composites filled with different proportions of BN were prepared through extrution compounding,injection moul... In order to explore the thermal conductivity of polypropylene(PP)/hexagonal boron nitride(BN) composites,PP composites filled with different proportions of BN were prepared through extrution compounding,injection moulding and compression moulding.The composites were filled with BN particles of 5 and 20 μm respectively,and their mass fractions in composites were considered.Percentage of BN was varied from 0 to 25wt% in steps of 5wt%.The effects of BN filler on mechanical properties of the composites were evaluated.The thermal behaviors were studied using DSC and TGA,and the thermal conductivity was also investigated by Laser Flash Device and the Model of 3D Heat Conduction respectively.The experimental results show that impact strength of PP/BN can be enhanced with the addition of BN,but that composites exhibit lower breaking elongation & tensile strength when compared to unfilled ones.It is found that mass fraction of BN influenced the final thermal stability and degree of crystallization of PP matrix,the degree of crystallization of PP with 15wt% of 20 μm BN can be improved by 25% than neat PP.Meanwhile,crystallization temperatures of PP composites are elevated by about 10 ℃.The thermal conductivity results demonstrate that the maximum value of the thermal conductivity is achieved from PP/BN with 20wt% of 20 μm BN,higher than that of pure PP by 95.65%,close to the simulation one. 展开更多
关键词 thermal properties POLYPROPYLENE COMPOSITES hexagonal boron nitride
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Peat properties of a tropical forest reserve adjacent to a fire-break canal
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作者 Dayang Nur Sakinah Musa Mohd Zahirasri Mohd Tohir +3 位作者 Xinyan Huang Luqman Chuah Abdullah Mohamad Syazaruddin Md Said Muhammad Firdaus Sulaiman 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期155-167,共13页
Tropical peat comprises decomposed dead plant material and acts like a sponge to absorb water,making it fully saturated.However,drought periods dry it readily and increases its vulnerability to fire.Peat fires emit gr... Tropical peat comprises decomposed dead plant material and acts like a sponge to absorb water,making it fully saturated.However,drought periods dry it readily and increases its vulnerability to fire.Peat fires emit greenhouse gases and particles contributing to haze,and prevention by constructing fire-break canals to reduce fire spread into forest reserves is crucial.This paper aims to determine peat physical and chemical properties near a fire-break canal at different fire frequency areas.Peat sampling was conducted at two forest reserves in Malaysia which represent low fire frequency and high fire frequency areas.The results show that peat properties were not affected by the construction of a fire-break canal,however lignin and cellulose content increased significantly from the distance of the canal in both areas.The study concluded that fire frequency did not significantly influence peat properties except for porosity.The higher fibre content in the high frequency area did not influence moisture content nor the ability to regain moisture.Thus,fire frequency might contribute differently to changes in physical and chemical properties,hence management efforts to construct fire-break canals and restoration efforts should protect peatlands from further degradation.These findings will benefit future management and planning for forest reserves. 展开更多
关键词 Peat fire Peat properties Fire-break canals Forest reserves
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Enhancing the mechanical properties of casting eutectic high -entropy alloys via W addition
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作者 Xu Yang Dezhi Chen +3 位作者 Li Feng Gang Qin Shiping Wu Ruirun Chen 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第6期1364-1372,共9页
The effect of W element on the microstructure evolution and mechanical properties of Al_(1.25)CoCrFeNi3 eutectic high-entropy alloy and Al_(1.25)CoCrFeNi_(3-x)W_(x)(x=0,0.05,0.1,0.3,and 0.5;atomic ratio)high-entropy a... The effect of W element on the microstructure evolution and mechanical properties of Al_(1.25)CoCrFeNi3 eutectic high-entropy alloy and Al_(1.25)CoCrFeNi_(3-x)W_(x)(x=0,0.05,0.1,0.3,and 0.5;atomic ratio)high-entropy alloys(HEAs)were explored.Results show that the Al_(1.25)CoCrFeNi_(3-x)W_(x) HEAs are composed of face-centered cubic and body-centered cubic(BCC)phases.As W content increases,the microstructure changes from eutectic to dendritic.The addition of W lowers the nucleation barrier of the BCC phase,decreases the valence electron concentration of the HEAs,and replaces Al in the BCC phase,thus facilitating the nucleation of the BCC phase.Tensile results show that the addition of W greatly improves the mechanical properties,and solid-solution,heterogeneous-interface,and second-phase strengthening are the main strengthening mechanisms.The yield strength,tensile strength,and elongation of the Al_(1.25)CoCrFeNi2.95W0.05 HEA are 601.44 MPa,1132.26 MPa,and 15.94%,respectively,realizing a balance between strength and plasti-city.The fracture mode of the Al_(1.25)CoCrFeNi_(3-x)W_(x) HEAs is ductile–brittle mixed fracture,and the crack propagates and initiates in the BCC phase.The eutectic lamellar structure impedes crack propagation and maintains plasticity. 展开更多
关键词 high-entropy alloy microstructure mechanical property fracture behavior
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