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Materials Science and Engineering

2020

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Articles 151 - 180 of 207

Full-Text Articles in Physical Sciences and Mathematics

Investigation Of 244cm Dynamics Production In A Wwer-1200 Reactor For Fuel Based On 235u And Mox Fuel, A. M. Petrovski, K. I. Usheva, T. N. Korbut, E. A. Rudak, M. O. Kravchenko, L. F. Babichev Mar 2020

Investigation Of 244cm Dynamics Production In A Wwer-1200 Reactor For Fuel Based On 235u And Mox Fuel, A. M. Petrovski, K. I. Usheva, T. N. Korbut, E. A. Rudak, M. O. Kravchenko, L. F. Babichev

Eurasian Journal of Physics and Functional Materials

244Cm is a very important nuclide due to the high specific heat release and it may become reasonable to recycle the spent nuclear fuel to extract this isotope. In this work, the dynamics of 244Cm isotope production for the fuel assembly of the WWER-1200 reactor with an enrichment of 4.95% and burnup up to 70 MW · day/kg was calculated using Serpent Monte Carlo code. A similar calculations was performed for MOX-based fuel assembly with the same irradiation characteristics. It has been shown that production of 244Cm in high burnup uranium dioxide fuel, and especially in MOX fuel, reaches a …


Neutron Transfer And Nuclear Breakup In 208pb(11li, 9li) Reaction, A. K. Azhibekov, V. V. Samarin, K. A. Kuterbekov Mar 2020

Neutron Transfer And Nuclear Breakup In 208pb(11li, 9li) Reaction, A. K. Azhibekov, V. V. Samarin, K. A. Kuterbekov

Eurasian Journal of Physics and Functional Materials

Neutron transfer and nuclear breakup processes in reaction with weakly bound nucleus 11Li at energies near the Coulomb barrier are investigated in the framework of the time-dependent Schrödinger equation. The evolution of probability density of outer weakly bound neutrons of 11Li in the collision with 208Pb was studied. The probabilities and cross sections of outer neutrons removal (breakup processes and transfer to target nucleus) were calculated. Theoretical predictions of the two-neutron removal probability values were obtained for angles from 140◦ to 180◦ . The theoretical results have close similarity with experimental data for the two-neutron removal in reaction 208Pb(11Li,9 Li).


Influence Of Nanoparticle Weight Fraction On Morphology And Thermal Properties Of Hdpe/Sio2 Composite Films, A. A. Nabiyev Mar 2020

Influence Of Nanoparticle Weight Fraction On Morphology And Thermal Properties Of Hdpe/Sio2 Composite Films, A. A. Nabiyev

Eurasian Journal of Physics and Functional Materials

High-density polyethylene (HDPE) composite films with di erent amounts of SiO 2 nanoparticles ( 1 - 20 % vol.) were prepared by melt blending using a high-pressure thermal pressing technique. The morphological characterization, surface topology and distribution of nanoparticles in polymer matrix of nanocomposites were investigated by using Scanning electron microscopy (SEM) and atomic force microscopy (AFM). The thermal characterization of the nanocomposites were investigated by di erential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). SEM and AFM results revealed that silica nanoparticles aggregates were distributed mainly homogeneously. The nano-fillers change supramolecular structure and surface morphology of HDPE strongly. DSC …


Phase Composition And Thermoelectric Properties Of The Nanocomposite Alloys Naxcu2-X-Ys, M. M. Kubenova, M. Kh. Balapanov, K. A. Kuterbekov, R. Kh. Ishembetov, A. M. Kabyshev, Y. Kh. Yulaeva Mar 2020

Phase Composition And Thermoelectric Properties Of The Nanocomposite Alloys Naxcu2-X-Ys, M. M. Kubenova, M. Kh. Balapanov, K. A. Kuterbekov, R. Kh. Ishembetov, A. M. Kabyshev, Y. Kh. Yulaeva

Eurasian Journal of Physics and Functional Materials

Nanocrystalline alloys of the compositions Na 0.05 Cu 1.95 S, Na 0.075 Cu 1.925 S, Na 0.10 Cu 1.90 S, Na 0.125 Cu 1.750 S, Na 0.15 Cu 1.85 S, Na 0.17 Cu 1.80 S, Na 0.20 Cu 1.77 S were synthesized in a melt medium mixtures of hydroxides NaOH and KOH at a temperature of about 165 ◦ C. X-ray phase analysis showed that the alloys are heterophasic and consist of phases of Cu 9 S 5 digenite, CuS 2 copper disulfide, Covellite CuS, Cu 7 S 4 anilite in various combinations. The crystallite sizes range from 16 to …


Research Of The Mechanical-Tribological Characteristics Of Ti3sic2/Tic Coatings After Annealing, D. B. Buitkenov, B. K. Rakhadilov, Zh. B. Sagdoldina, D. Erbolatuly, S. Amanzholov Mar 2020

Research Of The Mechanical-Tribological Characteristics Of Ti3sic2/Tic Coatings After Annealing, D. B. Buitkenov, B. K. Rakhadilov, Zh. B. Sagdoldina, D. Erbolatuly, S. Amanzholov

Eurasian Journal of Physics and Functional Materials

This article investigates the influence of thermal annealing on microhardness and wear resistance of the surface of steel U9/Y9 protected by a composite coating Ti 3 SiC 2 /TiC obtained by detonation sputtering. Thermal annealing was performed in the range of temperatures 700-900 ◦ C during 1 hour. Following annealing the formation of TiO 2 and an increase in the phase content of Ti 3 SiC 2 are observed. Higher microhardness was obtained in coatings subjected to annealing at 800 ◦ C, which can be explained by an increase in the content of carbonized titanium. As the annealing temperature rises …


Kinetics Of Radiation-Stimulated Processes On The Surface Of Oxide Materials, T. Tusseyev Mar 2020

Kinetics Of Radiation-Stimulated Processes On The Surface Of Oxide Materials, T. Tusseyev

Eurasian Journal of Physics and Functional Materials

The analysis of the experimental data shows that the processes of gas adsorption and radiation defects accumulation in metal oxides correlate with each other and most likely can be described in terms of equivalent kinetic equations. Given this circumstance, the kinetics of accumulation of radiation defects in oxides of di erent metals was analyzed. The obtained equations were used to analyze: a) the kinetics of accumulation of radiation defects in di erent oxide compounds; b) the data on the destruction of radiationinduced defects in the atmosphere of di erent gases, and on the kinetics of absorption by oxides of oxygen, …


Manifestations Of Pear-Shaped Clusters In Collinear Cluster Tri-Partition Of 252cf, Yu. V. Pyatkov, D. V. Kamanin, A. A. Alexandrov, I. A. Alexandrova, Z. I. Goryainova, E. A. Kuznetsova, A. O. Strekalovsky, O. V. Strekalovsky, V. E. Zhuchko, V. Malaza Mar 2020

Manifestations Of Pear-Shaped Clusters In Collinear Cluster Tri-Partition Of 252cf, Yu. V. Pyatkov, D. V. Kamanin, A. A. Alexandrov, I. A. Alexandrova, Z. I. Goryainova, E. A. Kuznetsova, A. O. Strekalovsky, O. V. Strekalovsky, V. E. Zhuchko, V. Malaza

Eurasian Journal of Physics and Functional Materials

Specific mode of the collinear cluster tri-partition of the252Cf nucleus is discussed. The structure manifests itself as a rhombic-spiral structure in the fission fragments correlation mass distribution.


Optimal Technological Modes Of Ion Implantation And Following Annealing For Forming Thin Nanosized Films Of Silicides, A. S. Rysbaev, S. U. Irgashev, A. S. Kasimov, D. Sh. Juraeva, J. B. Khujaniyazov, M. I. Khudoyberdieva Mar 2020

Optimal Technological Modes Of Ion Implantation And Following Annealing For Forming Thin Nanosized Films Of Silicides, A. S. Rysbaev, S. U. Irgashev, A. S. Kasimov, D. Sh. Juraeva, J. B. Khujaniyazov, M. I. Khudoyberdieva

Eurasian Journal of Physics and Functional Materials

The formation of nanosized films of silicides on the surface of Si (111) and Si (100) was studied by the method of low-energy ion implantation. The optimal technological modes of ion implantation and subsequent annealing for the formation of thin nanoscale films of silicides were determined. It is shown that the appearance of new surface superstructures is additional confirmation of the formation of thin silicide films with a single crystal structure.


Comparison Of Aluminum And Manganum Concentration In Akmola Region, Kazakhstan, A. G. Zhumalina, E. K. Sambayev, A. Sakaguchi, S. Endo, K. Tanaka, T. Kajimoto, N. Kawano, T. B. Suleimenov, K. Sh. Zhumadilov, M. Hoshi Mar 2020

Comparison Of Aluminum And Manganum Concentration In Akmola Region, Kazakhstan, A. G. Zhumalina, E. K. Sambayev, A. Sakaguchi, S. Endo, K. Tanaka, T. Kajimoto, N. Kawano, T. B. Suleimenov, K. Sh. Zhumadilov, M. Hoshi

Eurasian Journal of Physics and Functional Materials

The results of seasonal Al and Mn activity on the surface of the atmosphere above the city of Nur-Sultan are shown from October 2016 to January 2017. The technique of sampling aerosols in various fractions and further analysis of the data are described. Together with scientists from the University of Hiroshima (Hiroshima, Japan) and the University of Tsukuba (Tsukuba, Japan), the composition of aerosols in the air of Astana was monitored. The aim of the project was to develop a methodology for sampling aerosols in various fractions and conduct measurements on an ongoing basis. The studies were carried out using …


The Design Of A Continuous Wave Molecular Nitrogen Stimulated Raman Laser In The Visible Spectrum, Timothy J. Bate Mar 2020

The Design Of A Continuous Wave Molecular Nitrogen Stimulated Raman Laser In The Visible Spectrum, Timothy J. Bate

Theses and Dissertations

Hollow-core photonic crystal fibers (HCPCFs) shows promise as a hybrid laser with higher nonlinear process limits and small beam size over long gain lengths. This work focuses on the design of a CW molecular nitrogen (N2) stimulated Raman laser. N2 offers Raman gains scaling up to 900 amg, scaling higher than H2. The cavity experiment showed the need to include Rayleigh scattering in the high pressure required for N2 Raman lasing. Even at relatively low pressure ssuch as 1,500 psi, high conversion percentages should be found if the fiber length is chosen based on …


Cn And C2 Spectroscopy On The Pulsed Ablation Of Graphite In The Visible Spectrum, Brandon A. Pierce Mar 2020

Cn And C2 Spectroscopy On The Pulsed Ablation Of Graphite In The Visible Spectrum, Brandon A. Pierce

Theses and Dissertations

An experimental study was conducted on the nanosecond pulsed laser ablation of graphite using a KrF laser at a fluence of 3.8 J/cm2 in Air, Ar, He, and N2. Optical emissions spectroscopy revealed the C2 Swan sequences and the CN Violet sequences. A spectroscopic model was developed to extract the molecular rotational and vibrational temperatures of each excited species for t=0.5-10 microseconds after laser irradiation. The rovibrational temperatures were found to vary with background gas for the CN Violet; however, only the vibrational temperature varied between He and the other background gases for C2 Swan. …


Research Progresses In Polymeric Proton Exchange Membranes For Fuel Cells, Xu-Po Liu, Yun-Feng Zhang, Shao-Feng Deng, De-Li Wang, Han-Song Cheng Feb 2020

Research Progresses In Polymeric Proton Exchange Membranes For Fuel Cells, Xu-Po Liu, Yun-Feng Zhang, Shao-Feng Deng, De-Li Wang, Han-Song Cheng

Journal of Electrochemistry

Proton exchange membrane (PEM) is one of the key components in PEM fuel cells, which possesses the function of separating the cathode and anode, affording proton transport channels and preventing fuel permeability. The property of PEM significantly influences the performance and service life of fuel cells. Nowadays, the commercially used Nafion membranes have the shortcomings of serious fuel permeability, low proton conductivity at elevated temperature and high price, which limits the rapid development of PEM fuel cells. Therefore, it seems to be urgent to develop novel PEMs with low cost and good comprehensive properties. Polymeric proton exchange membrane is an …


Recent Progress In The Mechanistic Understanding Of Co2 Reduction On Copper, Matthew M Sartin, Wei Chen, Fan He, Yan-Xia Chen Feb 2020

Recent Progress In The Mechanistic Understanding Of Co2 Reduction On Copper, Matthew M Sartin, Wei Chen, Fan He, Yan-Xia Chen

Journal of Electrochemistry

In this review, we present the major developments in the understanding of the mechanisms of the electrochemical reduction of CO2 from a historical perspective. Most of the work discussed in this review was carried out at copper electrodes, as this is the only material at which hydrocarbons are produced in reasonable quantities. The emphasis focuses on the differentiation of mechanisms for the generation of C1 and C2 products as well as factors and methods for controlling the product selectivity of CO2 reduction. We have highlighted ambiguities, assumptions, and important methodologies, such as differential electrochemical mass spectrometry and electrochemical …


Challenges In The Activity And Stability Of Pt-Based Catalysts Toward Orr, Tuo Zhao, Er-Gui Luo, Xian Wang, Jun-Jie Ge, Chang-Peng Liu, Wei Xing Feb 2020

Challenges In The Activity And Stability Of Pt-Based Catalysts Toward Orr, Tuo Zhao, Er-Gui Luo, Xian Wang, Jun-Jie Ge, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The development of highly efficient oxygen reduction reaction (ORR) catalysts is the key to the commercialization of fuel cells, where the sluggish ORR reaction rate needs to be overcome by adjusting the intermediates adsorption energies on the catalytic surfaces. To-date, platinum (Pt)-based materials are the-state-of-the-art catalysts in terms of both activity and stability in ORR, making them the preferred choice for commercial applications. However, the high cost of Pt-based catalysts limits their widespread use, leading to massive effects paid in reducing Pt loading, improving catalyst activity and stability. This article illustrates the challenges in the ORR reaction and introduces the …


Effect Of Nitrogen Content In Catalyst Precursor On Activity Of Fen/C Catalyst For Oxygen Reduction Reaction, Zhi Yang, Ya-Yun Shen, E Zhou, Cheng-Ling Wei, Hao-Li Qin, Juan Tian Feb 2020

Effect Of Nitrogen Content In Catalyst Precursor On Activity Of Fen/C Catalyst For Oxygen Reduction Reaction, Zhi Yang, Ya-Yun Shen, E Zhou, Cheng-Ling Wei, Hao-Li Qin, Juan Tian

Journal of Electrochemistry

Non-noble metal catalysts with high activity and low cost have attracted increasing interest as potential catalysts for oxygen reduction reaction (ORR) to replace Pt-based catalysts. In this paper, the effect of nitrogen content in catalyst precursor on ORR activity of FeN/C catalyst was investigated by X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET) surface area and pore size distribution measurements, transmission electron microscope (TEM), thermogravimetric analysis (TGA), and rotating disk electrode (RDE) techniques. The results show that the most active catalyst was obtained by pyrolysis in argon at 1050 °C with a catalyst precursor containing 20wt% 1,10-phenanthroline, 1wt% Fe and Black Pearl 2000. …


Structures And Electrochemical Properties Of Sn-Cl Co-Doped Li2Mno3 As Positive Materials For Lithium Ion Batteries, Fei Wang, Huan-Huan Zhai, Du-Dan Wang, Yu-Peng Li, Kang-Hua Chen Feb 2020

Structures And Electrochemical Properties Of Sn-Cl Co-Doped Li2Mno3 As Positive Materials For Lithium Ion Batteries, Fei Wang, Huan-Huan Zhai, Du-Dan Wang, Yu-Peng Li, Kang-Hua Chen

Journal of Electrochemistry

Positive material Li2MnO3 shows the highest ratio of lithium to manganese among lithium-rich materials and exhibites the theoretical capacity up to 458 mAh·g -1, making it one of the most promising cathode materials. However, this material has the intrinsic low electrical conductivity and poor cycle stability. In this paper, Li2MnO3, the lithium-rich positive material, was prepared by sol-gel method using acetate as raw material and citric acid as a complexing agent. By using SnC2O4 as a tin source, Sn 4+ instead of Mn 4+ was introduced to obtain the materials …


Lithium Storage Performance Of High Capacity Material Si@CPzs In Lithium Ion Batteries, Qing-Nuan Zhang, Fang-Fang Zhang, Hong-Xia Li, Bing-Jun Yang, Xiao-Cheng Li, Juan Yang Feb 2020

Lithium Storage Performance Of High Capacity Material Si@CPzs In Lithium Ion Batteries, Qing-Nuan Zhang, Fang-Fang Zhang, Hong-Xia Li, Bing-Jun Yang, Xiao-Cheng Li, Juan Yang

Journal of Electrochemistry

Carbon layers with different thicknesses were introduced into the surfaces of silicon (Si) nanoparticles by sol-gel method using poly (cyclotriphosphazene-co-4, 4'-sulfonyldiphenol) as the carbon source. Technologies of X-ray diffraction, thermo-gravimetric analysis, Brunauer-Emmett-Teller and transmission electron microscopy were employed to analyze the structures and components of the as-prepared Si@CPZS composites. Electrochemical performance of Si@CPZS with different carbon thicknesses was studied. The results showed that Si@CPZS with carbon thickness of 10 nm possessed the best performance. Its capacity remained 940 mAh·g -1 after 290 cycles under 500 mA·g -1. As the addictive, the graphite-based anode contained 30% of Si@C …


Electrochemical Preparations And Applications Of Nano-Catalysts With High-Index Facets, Chi Xiao, Na Tian, Zhi-You Zhou, Shi-Gang Sun Feb 2020

Electrochemical Preparations And Applications Of Nano-Catalysts With High-Index Facets, Chi Xiao, Na Tian, Zhi-You Zhou, Shi-Gang Sun

Journal of Electrochemistry

The performance of catalysts highly depends on their surface structure and composition. Nanocrystals bounded by high-index facets usually exhibit high catalytic activity due to their high-density low-coordinated step atoms with high reactivity. In this paper, we have reviewed the preparations of noble metals (e.g., Pt, Pd and Rh) nanocatalysts with high-index facets by electrochemical square-wave potential method developed in our group. The square-wave potential method includes a nucleation procedure to generate nuclei, followed by a square-wave potential procedure for a certain period of time for the growth of nuclei into nanocrystals. The formation mechanism of high-index facets is also discussed. …


Research Progresses In Ni-Co-Mn/Al Ternary Concentration Gradient Cathode Materials For Li-Ion Batteries, Chun-Fang Zhang, Wen-Gao Zhao, Shi-Yao Zheng, Yi-Xiao Li, Zheng-Liang Gong, Zhong-Ru Zhang, Yong Yang Feb 2020

Research Progresses In Ni-Co-Mn/Al Ternary Concentration Gradient Cathode Materials For Li-Ion Batteries, Chun-Fang Zhang, Wen-Gao Zhao, Shi-Yao Zheng, Yi-Xiao Li, Zheng-Liang Gong, Zhong-Ru Zhang, Yong Yang

Journal of Electrochemistry

Nickel-rich ternary materials with large reversible capacity as well as high operating voltage are considered as the most promising candidate for next generation lithium-ion batteries (LIBs). However, the inferior cycle stability and thermal stability have limited their widely commercial applications. Concentration gradient design of Ni-Co-Mn/Al ternary concentration gradient materials have been extensively studied in the past decade, which can ensure high cycle capacity while maintaining excellent cycle stability. In this paper, the latest research progresses in Ni-Co-Mn/Al ternary concentration gradient materials for LIBs are reviewed. Firstly, we summarize the different synthesis methods of ternary concentration-gradient materials, especially focusing on the …


Preparation And Electrocatalytic Performance Of Nico2O4/Ni Foam For Hydrogen Peroxide Electrooxidation, Wei-Wei Chen, Fei-Fan Zhang, Jia-Liang Du, Yi Wang, Chun-Lin Zhao, Kai Zhu, Dian-Xue Cao, Gui-Ling Wang Feb 2020

Preparation And Electrocatalytic Performance Of Nico2O4/Ni Foam For Hydrogen Peroxide Electrooxidation, Wei-Wei Chen, Fei-Fan Zhang, Jia-Liang Du, Yi Wang, Chun-Lin Zhao, Kai Zhu, Dian-Xue Cao, Gui-Ling Wang

Journal of Electrochemistry

The electrodes of Ni foam supported NiCo2O4 nanowires were prepared by hydrothermal method, followed by a thermal treatment in air, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the NiCo2O4 nanowires had a diameter of about 50 nm with a length up to 3 ~ 5 μm. The catalytic performances of the Ni foam supported NiCo2O4 nanowires for H2O2 electrooxidation were studied by cyclic voltammetry and chronoamperometry. The results show that the Ni foam supported NiCo …


Preparations Of Nickel-Iron Hydroxide/Sulfide And Their Electrocatalytic Performances For Overall Water Splitting, Hang-Shuo Lu, Xiao-Bo He, Feng-Xiang Yin, Guo-Ru Li Feb 2020

Preparations Of Nickel-Iron Hydroxide/Sulfide And Their Electrocatalytic Performances For Overall Water Splitting, Hang-Shuo Lu, Xiao-Bo He, Feng-Xiang Yin, Guo-Ru Li

Journal of Electrochemistry

The Ni-Fe/Ti oxygen evolution electrode was prepared by electrodeposition on a titanium mesh substrate. Then, the as prepared Ni-Fe/Ti electrode was used to derive the Ni-Fe-S/Ti hydrogen evolution electrode through solid phase sulfuration. The effects of the molar ratio of Ni 2+ to Fe 3+ in the electrolyte and the amount of thiourea on the structures and electrochemical performances of Ni-Fe/Ti and Ni-Fe-S/Ti electrodes were investigated. The results show that the oxygen evolution performance of Ni-Fe/Ti electrode was first increased and then decreased with the increase of nickel ion content in the electrolyte. The Ni9Fe1/Ti electrode exhibited the best oxygen …


Atomic Force Microscopic Characterization Of Solid Electrolyte Interphase In Lithium Ion Batteries, Qing-Yu Dong, Yan-Li Chu, Yan-Bin Shen, Li-Wei Chen Feb 2020

Atomic Force Microscopic Characterization Of Solid Electrolyte Interphase In Lithium Ion Batteries, Qing-Yu Dong, Yan-Li Chu, Yan-Bin Shen, Li-Wei Chen

Journal of Electrochemistry

In recent years, the rapid growing in the electric vehicle market has raised higher requirement on the lithium-ion batteries (LIBs) performance towards energy density and safety. However, considering the successful development of LIBs techniques in the past 30 years, there is little room left for improving the LIBs performance on the aspects related to the electrode materials, battery structure design and production processes. It is important to pursue more comprehensive fundamental understanding in the entire system and working principle of LIBs. Solid electrolyte interphase (SEI), existing between the electrode material and the electrolyte, has been proved to be an important …


Effects Of Intrinsic Defects And Alloying With Fe On The Half-Metallicity Of Co2Mnsi, G. G. Baez Flores, Ivan A. Zhuravlev, Kirill Belashchenko Feb 2020

Effects Of Intrinsic Defects And Alloying With Fe On The Half-Metallicity Of Co2Mnsi, G. G. Baez Flores, Ivan A. Zhuravlev, Kirill Belashchenko

Kirill Belashchenko Publications

The electronic structure and half-metallic gap of Co2MnSi in the presence of crystallographic defects, partial Fe substitution for Mn, and thermal spin fluctuations are studied using the coherent potential approximation and the disordered local moment method. In the presence of 5% Co or Mn vacancies the Fermi level shifts down to the minority-spin valence-band maximum. In contrast to NiMnSb, both types of Mn antisite defects in Co2MnSi are strongly exchange coupled to the host magnetization, and thermal spin fluctuations do not strongly affect the half-metallic gap. Partial substitution of Mn by Fe results in considerable changes in the Bloch spectral …


Protein-Polysaccharide Composite Materials: Fabrication And Applications., Elizabeth J Bealer, Shola Onissema-Karimu, Ashley Rivera-Galletti, Maura Francis, Jason Wilkowski, David Salas-De La Cruz, Xiao Hu Feb 2020

Protein-Polysaccharide Composite Materials: Fabrication And Applications., Elizabeth J Bealer, Shola Onissema-Karimu, Ashley Rivera-Galletti, Maura Francis, Jason Wilkowski, David Salas-De La Cruz, Xiao Hu

Faculty Scholarship for the College of Science & Mathematics

Protein-polysaccharide composites have been known to show a wide range of applications in biomedical and green chemical fields. These composites have been fabricated into a variety of forms, such as films, fibers, particles, and gels, dependent upon their specific applications. Post treatments of these composites, such as enhancing chemical and physical changes, have been shown to favorably alter their structure and properties, allowing for specificity of medical treatments. Protein-polysaccharide composite materials introduce many opportunities to improve biological functions and contemporary technological functions. Current applications involving the replication of artificial tissues in tissue regeneration, wound therapy, effective drug delivery systems, and …


Responsive Economic Model Predictive Control For Next-Generation Manufacturing, Helen Durand Feb 2020

Responsive Economic Model Predictive Control For Next-Generation Manufacturing, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

There is an increasing push to make automated systems capable of carrying out tasks which humans perform, such as driving, speech recognition, and anomaly detection. Automated systems, therefore, are increasingly required to respond to unexpected conditions. Two types of unexpected conditions of relevance in the chemical process industries are anomalous conditions and the responses of operators and engineers to controller behavior. Enhancing responsiveness of an advanced control design known as economic model predictive control (EMPC) (which uses predictions of future process behavior to determine an economically optimal manner in which to operate a process) to unexpected conditions of these types …


Defect-Free Plastic Deformation Through Dimensionality Reduction And Self-Annihilation Of Topological Defects In Crystalline Solids, Yipeng Gao, Yongfeng Zhang, Larry K. Aagesen, Jianguo Yu, Min Long, Yunzhi Wang Feb 2020

Defect-Free Plastic Deformation Through Dimensionality Reduction And Self-Annihilation Of Topological Defects In Crystalline Solids, Yipeng Gao, Yongfeng Zhang, Larry K. Aagesen, Jianguo Yu, Min Long, Yunzhi Wang

Computer Science Faculty Publications and Presentations

As a signature of symmetry-breaking processes, the generation and annihilation of topological defects (domain walls, strings, etc.) are of great interest in condensed matter physics and cosmology. Here we propose a distinctive self-organization process through phase transitions, in which all the generated topological defects are dimensionality reduced and self-annihilated. In crystalline solids, such a unique mechanism allows a perfect single crystal after plastic deformation, which originates from the coupling of different types of broken symmetries.


Ii-Vi Type-Ii Quantum Dot Superlattices For Novel Applications, Vasilios Deligiannakis Feb 2020

Ii-Vi Type-Ii Quantum Dot Superlattices For Novel Applications, Vasilios Deligiannakis

Dissertations, Theses, and Capstone Projects

In this thesis, we discuss the growth procedure and the characterization results obtained for epitaxially grown submonolayer type-II quantum dot superlattices made of II-VI semiconductors. We have investigated the spin dynamics of ZnSe layers with embedded type-II ZnTe quantum dots and the use of (Zn)CdTe/ZnCdSe QDs for intermediate band solar cell (IBSC). Samples with a higher quantum dot density exhibit longer electron spin lifetimes, up to ~1 ns at low temperatures. Tellurium isoelectronic centers, which form in the ZnSe spacer regions as a result of the growth conditions, were also probed. A new growth sequence for type-II (Zn)CdTe/ZnCdSe (QDs) was …


The Fabrication And Properties Of Magnetorheological Elastomers Employing Bio-Inspired Dopamine Modified Carbonyl Iron Particles, Yanfen Zhou, Lele Li, Wenyue Li, Shipeng Wen, Liang Jiang, Stephen Jerrams, Jianwei Ma, Shaojuan Chen Jan 2020

The Fabrication And Properties Of Magnetorheological Elastomers Employing Bio-Inspired Dopamine Modified Carbonyl Iron Particles, Yanfen Zhou, Lele Li, Wenyue Li, Shipeng Wen, Liang Jiang, Stephen Jerrams, Jianwei Ma, Shaojuan Chen

Articles

To obtain magnetorheological elastomers (MREs) with improved mechanical properties and exhibiting an enhanced magnetorheological (MR) effect, bio-inspired dopamine modification has been used to improve the functionality at the surface of carbonyl iron (CI) particles. Various techniques including x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to confirm that a polydopamine (PDA) layer of about 27.5 nm had been successfully deposited on the surface of the carbonyl iron particles prior to their inclusion in the MRE composites. The magnetic properties of PDA modified CI particles were shown to be almost the same as those …


Enhanced Covalent Interface, Crosslinked Network And Gas Barrier Property Of Functionalized Graphene Oxide/Styrene-Butadiene Rubber Composites Triggered By Thiol-Ene Click Reaction, Long Zheng, Stephen Jerrams, Tian Su, Zongchao Xu, Liqun Zhang, Li Liu, Shipeng Wen Jan 2020

Enhanced Covalent Interface, Crosslinked Network And Gas Barrier Property Of Functionalized Graphene Oxide/Styrene-Butadiene Rubber Composites Triggered By Thiol-Ene Click Reaction, Long Zheng, Stephen Jerrams, Tian Su, Zongchao Xu, Liqun Zhang, Li Liu, Shipeng Wen

Articles

The high gas barrier property of a rubber composite is of great significance for reducing the exhaust gas emissions due to tire rolling resistance and hence the contribution this factor makes to environmental protection. Enhanced covalent interfaces and crosslinked networks are crucial to the gas barrier property of rubber composites. In this research, γ-mercaptopropyltriethoxysilane (MPS) modified GO (MGO)/styrene-butadiene rubber (SBR) composites were prepared by a synergetic strategy of latex compounding method and thiol-ene click reaction. It was found that the mercapto groups in MGO reacted with the vinyl groups in SBR molecules through thiol-ene click reaction during the crosslinking process …


Ac Conductivity Studies Of Polyethylene-Oxide-Garnet Type Li7la3zr2o12 Hybrid Composite Solid Polymer Electrolyte For Li-Ion Battery, Parisa Bashiri Jan 2020

Ac Conductivity Studies Of Polyethylene-Oxide-Garnet Type Li7la3zr2o12 Hybrid Composite Solid Polymer Electrolyte For Li-Ion Battery, Parisa Bashiri

Wayne State University Dissertations

Solid electrolytes including ceramics and polymers are considered to be the ultimate substitute for organic liquid electrolytes currently used in commercialized lithium ion batteries to address the safety concerns due to Li dendrite growth and internal short circuiting. However, low ionic conductivity due to high grain boundary resistance in ceramics and semi-crystalline nature of polymers has held back the solid electrolytes from being used in Li-ion batteries. Polyethylene oxide (PEO), complexed with a Li-salt, is a well-studied polymer electrolyte showing ionic conductivity properties at room temperature. However, the coexistence of amorphous and crystalline regions at room temperature (< Tm, the melting temperature) has

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