检索结果-内蒙古大学图书馆

Solute drag-controlled grain growth in magnesium investigated by quasi in-situ orientation mapping and level-set simulations

引用

Journal of Magnesium and Alloys 2023年第7期11卷 2312-2325页

作者： Risheng Pei Yujun Zhao Muhammad Zubair Sangbong Yi Talal Al-Samman Institut für Metallkunde und Materialphysik RWTH Aachen University52056 AachenGermany Institute of Materials and Process Design Helmholtz-Zentrum Hereon21502 GeesthachtGermany Department of Metallurgical and Materials Engineering Faculty of ChemicalMetallurgical&Polymer EngineeringUniversity of Engineering&Technology(UET)LahorePakistan Institute for Materials Ruhr-Universität Bochum44801 BochumGermany

Critical properties of metallic materials,such as the yield stress,corrosion resistance and ductility depend on the microstructure and its grain size and size *** atoms that favorably segregate to grain boundaries produce a pinning atmosphere that exerts a drag pressure on the boundary motion,which strongly affects the grain growth behavior during *** the current work,the characteristics of grain growth in an annealed Mg-1 wt.%Mn-1 wt.%Nd magnesium alloy were investigated by advanced experimental and modeling *** quasi in-situ orientation mappings with a scanning electron microscope were performed to track the evolution of local and global microstructural characteristics as a function of annealing *** segregation at targeted grain boundaries was measured using three-dimensional atom probe ***-set computer simulations were carried with different setups of driving forces to explore their contribution to the microstructure development with and without solute *** results showed that the favorable growth advantage for some grains leading to a transient stage of abnormal grain growth is controlled by several drivers with varying importance at different stages of *** longer annealing times,residual dislocation density gradients between large and smaller grains are no longer important,which leads to microstructure stability due to predominant solute *** fluctuations in residual dislocation energy and solute concentration near grain boundaries cause different boundary segments to migrate at different rates,which affects the average growth rate of large grains and their evolved shape.

关键词： Magnesium alloys Grain growth Quasi in-situ EBSD Level-set simulation Solute drag Dislocation density gradient

来源：评论

学校读者我要写书评

暂无评论

Formulation of Malaysian clay into inert ceramic balls: Effect of sintering temperature

引用

Materials Today: Proceedings 2023年 75卷 197-201页

作者： Zainudin, Fikri Hakim Zulkifli, Muhammad Shafiq Saud, Anisah Sajidah Salim, Nurjannah Ani, Hanafi Hisyam, Anwaruddin Edy Sutjipto, Agus Geter Ab. Rahim, Mohd Hasbi Faculty of Industrial Sciences and Technology Universiti Malaysia Pahang Lebuhraya Tun Razak Pahang Kuantan 26300 Malaysia Department of Manufacturing and Materials Kulliyyah of Engineering International Islamic University Malaysia Jalan Gombak Kuala Lumpur 53100 Malaysia Faculty of Chemical and Process Engineering Technology Universiti Malaysia Pahang Lebuhraya Tun Razak Pahang Kuantan 26300 Malaysia

Ceramic ball support bed materials are used in multiple industries with the aim of providing support for the catalytic materials and assisting the reaction. The majority of ceramic ball products used in Malaysia are either imported as finished products or domestically produced using an imported formulated powder. Besides, the characteristics of sintered ceramic balls depend on the specific powder metallurgy route, including the material composition, range of particle size, and sintering process. Thus, this study focuses on producing inert ceramic balls from local Malaysian raw materials and optimising the sintering temperature with the aim of fulfilling the Universal Oil Products (UOP) standard requirements. The research utilises local clay raw material originating from Trong, Perak, Malaysia. The formulation of each ball was formulated based on a mixture of kaolinite clay, potash feldspar, and silica sand. The sintering process was then varied between 1250 and 1350 °C to tune the character of the finished ceramic ball product. The characterization of the ceramic ball was carried out based on the UOP standard and complemented with X-ray Diffractometer (XRD), Scanning Electron Microscope – Energy Dispersive X-ray (SEM-EDX), and X-ray Fluorescence (XRF) analysis. All tested ceramic balls meet the requirements of the UOP standard. In fact, locally formulated samples had approximately twice the crushing strength of required standards. Different sintering temperatures affect the quartz phase, kaolinite dehydroxylation, mullite formation, and feldspar fusion, thus controlling the final physical–mechanical properties of ceramic balls. Overall, the sintering temperature of 1300 °C provides the most promising output in terms of the quality of ceramic balls and the cost consideration involving the high-temperature heating process. © 2022

关键词： Kaolinite

来源：评论

学校读者我要写书评

暂无评论

Trace doping realizing superior electrochemical performance in P2-type Na_(0.50)Li_(0.08)Mn_(0.60)Co_(0.16)Ni_(0.16)0_(2)cathode for sodium-ion batteries

引用

Chinese chemical Letters 2023年第12期34卷 387-391页

作者： Hongying Hou Jinxu Qiu Bao Li Liang Wang Zhuangzhuang Zhang Mengmin Jia Xiaobing Lai Mingming Han Pengyao Yan Dai-Huo Liu Dongmei Dai Bao Wang Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093 China Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals Key Laboratory of Green Chemical Media and ReactionsMinistry of EducationSchool of Chemistry and Chemical EngineeringHenan Normal UniversityXinxiang 453007China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

P2-type layered oxides are receiving significant interest due to their superior structure and intrinsic *** are strenuous attempts to balance the structure stability,phase transition as well as desirable electrochemical performances by inducing anion/cation ions,changing morphology,adjusting valence,*** this work,several same-period elements of Sc,Ti,V,Cr,Fe,Cu and Zn are doped into Na_(0.50)Li_(0.08)Mn_(0.60)Co_(0.16)Ni_(0.16)O_(2)cathodes,which are manipulated by ions radii and valence state,further studied by operando X-ray powder diffraction patterns(XRD).As a result,the Cu^(2+)doped cathode performed higher rate capacities(as high as 86 mAh/g even at 10 C)and more stable structures(capacity retention of~89.4%for 100 cycles),which owing to the synergistic effect among the tightened TMO_(2)layer,enlarged d-spacing,reduce O-O electrostatic repulsion,ameliorate lattice distortion as well as mitigate ordering of Na^(+)/vacancy.

关键词： P2-type layeredoxide Same-period elements doping Rietveld refinement Operando XRD Sodium-ion battery

来源：评论

学校读者我要写书评

暂无评论

Optimization of Polymeric Nanofluid Oil Recovery Mechanisms at Reservoir Condition

Optimization of Polymeric Nanofluid Oil Recovery Mechanisms ...

引用

2024 SPE Nigeria Annual International Conference and Exhibition, NAIC 2024

作者： Al Ani, M. Panis, N.I. Manikumar, Y. Sidek, M.A. Jaafar, M.Z. Ridzuan, N. Gbonhinbor, J. Umunnawuike, C. Money, B. Agi, A. Department of Petroleum Engineering School of Chemical and Energy Engineering Faculty of Engineering Universiti Teknologi Malaysia Johor Bahru Malaysia Faculty of Chemical and Process Engineering Technology College of Engineering Technology Universiti Malaysia Pahang Al-Sultan Abdullah Pahang Gambang Malaysia Department of Petroleum Engineering Niger Delta University Wilberforce Island Amassoma Yenagoa Nigeria Centre for Research in Advanced Fluid and Processes Fluid Centre Universiti Malaysia Pahang Al-Sultan Abdullah Pahang Gambang Malaysia

ISBN: (纸本)9781959025474

Nanoparticles have been used to improve the properties of oilfield polymers however, at higher and prolonged temperature, dihydroxylation of the bonds occurs decreasing the affinity of the oilfield polymers towards the surface of the nanoparticles. Hence, polymeric nanoparticles (LPNP) with rigid structures have been sought after to circumvent this problem. Therefore, in this study, LPNP was synthesized from sago palm (Metroxylon sagu) bark and used as a rheological agent to improve the viscosity of displacement fluids. Thereafter, the synthesized LPNP was characterized via transmission electron microscopy, particle size analysis, zeta potential, Fourier transform infrared spectroscopy and thermogravimetric analysis. Then, the rheological flow behaviour of lignin polymeric nanofluid (LPNF) was investigated at low and high shear rates utilizing a 350 RST Brookfield rheometer. Box-Behnken design was used to simulate the effect of salinity, shear rate, concentration, and temperature on the viscosity of LPNF. Statistical analysis of variance was used to analyse various parameters of the model. Finally, any parameter combination that resulted in the maximum viscosity was recorded and optimized using a multi-response surface model. The synthesis method was efficacious in producing LPNP with a size range of 10-23 nm. Besides, LPNF exhibited shear thinning and pseudoplastic behaviours even at high salinity and showed good stability up to a temperature of 170°C. The predicted viscosity with a regression coefficient (R2) of 0.8 indicates that the experimental data were accounted for by the model. The desirability of 0.95, which is close to unity, indicates that statistical analysis and experimental evidence have demonstrated that LPNF has acceptable flow behaviour under reservoir conditions. Copyright © 2024, Society of Petroleum Engineers.

关键词： Fourier transform infrared spectroscopy

来源：评论

学校读者我要写书评

暂无评论

Ionic liquids: a new generation of efficient polyvinyl chloride thermal stabilizers

引用

Journal of Umm Al-Qura University for Applied Sciences 2024年第1期10卷 12-19页

作者： Akram, Evon Rashad, Alaa Ali, Muataz Zainulabdeen, Khalid Jasim, Basma Mohammed, Salam Yusop, Rahimi Al-Amiery, Ahmed Yousif, Emad AL-Nahrain Nanorenewable Energy Research Center Al-Nahrain University Jadriya Baghdad Iraq Department of Chemistry College of Science Al‐Nahrain University Jadriya Baghdad Iraq Department of Chemical Industries Institute of Technology-Baghdad Middle Technical University Baghdad Iraq Department of Chemical and Petrochemical Engineering College of Engineering and Architecture University of Nizwa Nizwa Oman School of Chemical Science and Food Technology Faculty of Science and Technology University Kebangsaan Malaysia Selangor Bangi 43600 Malaysia Department of Chemical and Process Engineering Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia Selangor Bangi 43600 Malaysia Energy and Renewable Energies Technology Center University of Technology Baghdad 10001 Iraq

Polyvinyl chloride (PVC), is one of the main synthetic materials used widely in many applications of our life aspects today. Though, the practical usage of it was always affected by some destructive factors like UV-light and heat. The optical and surface characteristics of pure and modified PVC thin films were compared throughout a temperature range of 25–55 °C. It was found that the intensity of the amine group in modified PVC varied with temperature. Surface morphology properties studied by AFM results;the ionic liquid was proven to comparably increases the stability of PVC surface while the roughness was less than pure PVC with increasing temperature. Optical microscope pictures, manifest PVC as drops at 55 °C, while, in modified PVC at the same temperature, the PVC surface was noticeably more stable. Finally, the energy gap of PVC pure and modified PVC thin films are studied. At 55 °C, the modified PVC's energy gap value increased from 3.64 eV at ambient temperature to 4.28 eV. This makes it more isolated when compared to pure PVC, which has an energy gap of 3.04 eV at ambient temperature and 3.1 eV at 55 °C and is a semiconductor. © 2023, The Author(s).

关键词： Energy gap Ionic liquid Morphology PVC Thermal stabilizers

来源：评论

学校读者我要写书评

暂无评论

Comparisons of Organic Acid and Inorganic Acid Pretreatment for Production of Reducing Sugar and Ethanol Production from Coffee Shell 1

引用

7th Asia Conference on Environment and Sustainable Development, ACESD 2022

作者： Kitiborwornkul, Nichaphat Jullsri, Phakamas Tantayotai, Prapakorn Tandhanskul, Atittaya Sriariyanun, Malinee Biorefinery and Process Automation Engineering Center Department of Chemical and Process Engineering The Sirindhorn International Thai-German Graduate School of Engineering King Mongkut University of Technology North Bangkok Bangkok Thailand Department of Biotechnology Faculty of Technology Rajabhat Maha Sarakham University Kantarawichai Maha Sarakham Thailand Department of Microbiology Faculty of Science Srinakharinwirot University Bangkok Thailand Department of Food Technology Faculty of Biotechnology Assumption University Bangkok Thailand

ISBN: (数字)9789819941018

ISBN: (纸本)9789819941001

Growing consumption of coffee beverages leads to a vast amount of coffee waste production, and there are few official reports on proper waste management. Via a biorefining process, coffee waste, as a type of lignocellulose, has the potential to be converted to value-added biochemicals and biofuels. In a biorefining process of lignocellulose, pretreatment process is an important step for modification of the structure of lignocellulose to be more vulnerable to enzymatic saccharification. In this study, the effects of pretreatments by using organic acids (oxalic acid, citric acid, and acetic acid) and inorganic acid (sulfuric acid and hydrochloric acid) of coffee shell on reducing sugar and ethanol production were comparatively evaluated. Reducing sugars obtained from citric acid-pretreated were 27.16 mg, which were higher than untreated samples by 1.62-fold times. The cellulose content of citric acid-pretreated sample was enriched to 38.25%, while the cellulose content in untreated sample was 13.10%, suggesting the removal of hemicellulose caused by acid pretreatment. Citric acid pretreatment improves ethanol production by 5.1-fold times when compared to untreated sample. Altogether, organic acid is demonstrated to be an effective chemical for coffee waste pretreatment with lower toxicity and cost, compared to inorganic acid. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd 2023.

关键词： Lignocellulose

来源：评论

学校读者我要写书评

暂无评论

A preliminary study of pyrolysis kinetics among various types of oil palm wastes 6

A preliminary study of pyrolysis kinetics among various type...

引用

6th National Conference on Postgraduate Research, NCON-PGR 2022

作者： Yong, Yung Sheng Abdul Rasid, Ruwaida Ismail, Mazni Faculty of Chemical and Process Engineering Technology Universiti Malaysia Pahang Al-Sultan Abdullah Gambang Pahang26300 Malaysia

Oil palm waste such as empty fruit bunch (EFB), mesocarp fibre (MF) and palm kernel shell (PKS) are some of the abundant wastes produced by oil palm mills which have great potential to replace fossil fuel through the application of thermochemical processes like torrefaction which produces solid biofuel and pyrolysis that produces bio-oils. The study of the kinetics of a reaction indicates the activation energy and frequency factor of the reaction are often applied in the design of a reactor. In this study, the kinetics of pyrolysis of oil palm wastes were investigated with the aid of a derivative thermogravimetric graph (DTG) using thermogravimetric analyzers. Model-fitting methods including Arrhenius, Coats-Redfern (CR) and Kennedy-Clarke (KC) models were applied to obtain the kinetic parameters which are activation energy (E) and pre-exponential factor (A). To determine the best model-fitting methods, a reaction order mechanism was applied. For the best model, by comparing how fit is the model to the data, the highest regression coefficient was achieved by the CR model for EFB, MF and PKS. Therefore, it is clear that the CR model provides the most accurate estimates of the kinetics of the pyrolysis of oil palm wastes. © 2022 Elsevier Ltd. All rights reserved.

关键词： Activation energy

来源：评论

学校读者我要写书评

暂无评论

The effect of solids on interfacial rheology and the performance of coalescence filters

引用

chemical and process engineering - Inzynieria Chemiczna i Procesowa 2021年第4期42卷 337-348页

作者： Krasiński, Andrzej Soltan, Lukasz Kozyrski, Jakub Warsaw University of Technology Faculty of Chemical and Process Engineering Waryńskiego 1 Warsaw00-645 Poland

The paper presents a research work on the process of emulsion separation by filtration-coalescence method in the presence of solid particles. A polyester PBT coalescence medium was used in experiments of water removal from diesel fuel. Apart from parameters representing the geometry and inherent properties of coalescence filters, the additional emulsion constituents such as surfactants and solid particles also affect the process. These constituent can cover fibres and they can also influence emulsion properties. It has been experimentally confirmed that contrary to surface active compounds, which stabilise the emulsion, the presence of specific solid particles decreased the system stability. If surface active compounds are present in the system, the influence of solid particles is different at the same concentration level depending on their type. The destabilization of emulsion due to the presence of Arizona dust was more pronounced. Although the presence of particles mitigated the effect of surfactants, their deposition in the filter media oppositely affected the coalescence process depending on solid type. Oleophilic iron oxide particles improved the separation efficiency of water from diesel fuel, while Arizona test dust had a negative impact on the separation process performance. © 2021. The Author(s)

关键词： Diesel fuels

来源：评论

学校读者我要写书评

暂无评论

Experimental and numerical investigation of axial and tangential forces in a stirred tank with yield-stress fluids

引用

chemical and process engineering - Inzynieria Chemiczna i Procesowa 2021年第2期42卷 173-190页

作者： Story, Anna Story, Grzegorz Jaworski, Zdzislaw West Pomeranian University of Technology in Szczecin Faculty of Chemical Technology and Engineering Department of Chemical and Process Engineering al. Piastów 42 Szczecin71-065 Poland

Complex rheological properties of yield-stress materials may lead to the generation of an intensive mixing zone near a rotating impeller. From the practical point of view, the zone should cover most of the stirred liquid. According to the literature review, several parameters may affect the size of the mixing zone, in particular forces exerted on the liquid. This paper presents both experimental and numerical investigation of axial and tangential forces generated during mechanical mixing of yield-stress fluids in a stirred tank. The tested fluids were aqueous solutions of Carbopol Ultrez 30 of concentration either 0.2 or 0.6 wt% and pH = 5.0. The study was performed for three types of impeller, pitched blade turbine, Prochem Maxflo T and Rushton turbine, in a broad range of their rotational speed, N= 60 − 900 rpm. The axial and tangential forces were calculated from the apparent mass of the stirred tank and torque, respectively. The experimental results were compared with CFD predictions, revealing their good agreement. Analysis of the generated forces showed that they are dependent on the rheological characteristic of liquid and the impeller type. It was also found that although axial force was smaller than tangential force, it significantly increased the resultant force. © 2021. The Author(s)

关键词： Computational fluid dynamics

来源：评论

学校读者我要写书评

暂无评论

Energetic efficiency of mixing in a periodically reoriented Dean flow

引用

chemical and process engineering - Inzynieria Chemiczna i Procesowa 2021年第4期42卷 391-410页

作者： Rożeń, Antoni Kopytowski, Janusz Warsaw University of Technology Faculty of Chemical and Process Engineering Waryńskiego 1 Warszawa00-645 Poland

The energetic efficiency of mixing is studied numerically in a continuous flow mixer constructed from a sequence of alternately twisted pipe bends. Counter-rotating vortices present in the curved channels and known as Dean vortices narrow the distribution of the residence time of fluid elements and accelerate the generation of a new material surface without obstructing the main flow and increasing the risk of fouling or flow stoppage. Cyclic twisting of the pipe curvature allows for quick reorientation of Dean vortices. The reorientation induces chaotic advection in a stable three-dimensional flow and speeds up mixing. The effect of computational domain discretisation for the low and medium Reynolds numbers (20 © 2021. The Author(s)

关键词： Computational fluid dynamics

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：