Detonation Synthesis Of Nanoscale Silicon Carbide From Elemental Silicon,
2022
Missouri University of Science and Technology
Detonation Synthesis Of Nanoscale Silicon Carbide From Elemental Silicon, Martin J. Langenderfer, Yue Zhou, Jeremy Lee Watts, William Fahrenholtz, Catherine E. Johnson
Materials Science and Engineering Faculty Research & Creative Works
Direct reaction of precursors with the products of detonation remains an underexplored area in the ever-growing body of detonation synthesis literature. This study demonstrated the synthesis of silicon carbide during detonation by reaction of elemental silicon with carbon products formed from detonation of RDX/TNT mixtures. Continuum scale simulation of the detonation showed that energy transfer by the detonation wave was completed within 2–9 μs depending on location of measurement within the detonating explosive charge. The simulated environment in the detonation product flow beyond the Chapman-Jouguet condition where pressure approaches 27 GPa and temperatures reach 3300 K was thermodynamically suitable for …
Control Of High-Temperature Static And Transient Thermomechanical Behavior Of Simo Ductile Iron By Al Alloying,
2022
Missouri University of Science and Technology
Control Of High-Temperature Static And Transient Thermomechanical Behavior Of Simo Ductile Iron By Al Alloying, Semen Naumovich Lekakh, Catherine E. Johnson, L. Godlewski, Mei Li
Materials Science and Engineering Faculty Research & Creative Works
Silicon and molybdenum (SiMo) ductile iron is commonly used for exhaust manifolds because these components experience thermal cycling in oxidizing environment, which requires resistance to fatigue during transient thermomechanical loads. Previous studies have demonstrated that alloying elements, such as Al, to SiMo ductile iron reduces the amount of surface degradation during static high-temperature exposure. However, deterioration of sphericity of the graphite nodules and a decrease in ductility could affect the tendency of cracking during thermal cycling. In this article, the effect of Al alloying on static and transient thermomechanical behavior of SiMo ductile iron was investigated to optimize the amount …
Strategy For Conjugating Oligopeptides To Mesoporous Silica Nanoparticles Using Diazirine-Based Heterobifunctional Linkers,
2022
University of Kentucky
Strategy For Conjugating Oligopeptides To Mesoporous Silica Nanoparticles Using Diazirine-Based Heterobifunctional Linkers, Md Arif Khan, Ramy W. Ghanim, Maelyn R. Kiser, Mahsa Moradipour, Dennis T. Rogers, John M. Littleton, Luke H. Bradley, Bert C. Lynn, Stephen E. Rankin, Barbara L. Knutson
Chemical and Materials Engineering Faculty Publications
Successful strategies for the attachment of oligopeptides to mesoporous silica with pores large enough to load biomolecules should utilize the high surface area of pores to provide an accessible, protective environment. A two-step oligopeptide functionalization strategy is examined here using diazirine-based heterobifunctional linkers. Mesoporous silica nanoparticles (MSNPs) with average pore diameter of ~8 nm and surface area of ~730 m2/g were synthesized and amine-functionalized. Tetrapeptides Gly-Gly-Gly-Gly (GGGG) and Arg-Ser-Ser-Val (RSSV), and a peptide comprised of four copies of RSSV (4RSSV), were covalently attached via their N-terminus to the amine groups on the particle surface by a heterobifunctional linker, …
Special Topic On Materials And Devices For 5g Electronics,
2022
National Institute of Standards and Technology
Special Topic On Materials And Devices For 5g Electronics, Nathan D. Orloff, Rick Ubic, Michael Lanagan
Materials Science and Engineering Faculty Publications and Presentations
Next generation communications are inspiring entirely new applications in education, healthcare, and transportation. These applications are only possible because of improvements in latency, data rates, and connectivity in the latest generation. Behind these improvements are new materials and devices that operate at much higher frequencies than ever before, a trend that is likely to continue.
Study Of Various Quality Characteristics Of Polyester Fibers Obtained On The Basis Of Primary And Secondary Polyethylene Terephthalate,
2022
Tashkent Chemical-Technological Institute, Tashkent, Uzbekistan
Study Of Various Quality Characteristics Of Polyester Fibers Obtained On The Basis Of Primary And Secondary Polyethylene Terephthalate, Samida Ernzarova, Asror Juraev, Muzaffar Alimukhamedov, Farhod Magrupov
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of study is comprehensive determination of various quality characteristics of polyester fibers obtained on the basis of primary and secondary polyethylene terephthalate. The analysis of the raw material base of pre-oriented yarns (POY) threads has been carried out. The technological, physicomechanical properties, as well as the structure of the primary and secondary polyethylene terephthalate used in the production of the threads have been studied. The structure and properties of polyethylene terephthalate changed: the properties were worse, the structure were amorphous, the molecular weight decreased. The structure of recycled polyethylene terephthalate changed as a result of technological conversions in …
Мulti-Layer Fibrous Material Based On Textile Waste,
2022
Tashkent Institute of Textile and Light Industry, Tashkent, Uzbekistan
Мulti-Layer Fibrous Material Based On Textile Waste, Sevara Alimkhanova, Nodir Mirzaev, Adham Rafikov
CHEMISTRY AND CHEMICAL ENGINEERING
At the textile and sewing and knitting enterprises of the Republic of Uzbekistan, the number of which increases every year, a sufficient amount of technological waste is accumulated, which formed in the processes of sizing yarn, starting and setting up equipment, designing and sewing products. Meanwhile, there is a shortage of warm, comfortable, light, soft lining materials for clothes and shoes based on natural raw materials. With the purpose of rational use of textile waste - shredded, disheveled scraps of fabric and knitwear, a multilayer nonwoven material for details of clothing and footwear has been obtained. The material formed by …
Spectral Features And Hydrogen Bond Structure Of Aqueous Solutions Of Ethanol,
2022
Ion-plasma and Laser Technologies Institute, Tashkent, Uzbekistan
Spectral Features And Hydrogen Bond Structure Of Aqueous Solutions Of Ethanol, Dilbar Bozorova, Shukur Gofurov, Mavlonbek Ziyayev, Abdulmutallib Kokhkharov, Oksana Ismailova
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of this work is develop an approach that makes it possible to study the spectral properties and structure of intermolecular hydrogen bonds in aqueous solutions of ethanol formed in systems whose existence in a gaseous medium or an isolated state is practically impossible. This approach bases on the combined use of infrared spectroscopy and molecular dynamics (MD) methods. An analysis give the structural reorganization of water molecules depending on the concentration of ethanol alcohol. It has been shown that the method of molecular dynamics with classical force fields makes it possible to explicitly take into account the molecules …
Determination Of The Stability Of Complex Compounds Of Copper (Ii), Zinc (Ii), Cadmium (Ii) And Silver (I) With Covalently Immobilized Sulfur Contain Ligands,
2022
Termez State University, Termez, Uzbekistan
Determination Of The Stability Of Complex Compounds Of Copper (Ii), Zinc (Ii), Cadmium (Ii) And Silver (I) With Covalently Immobilized Sulfur Contain Ligands, Sherzod Kasimov, Khayit Turaev, Abdulakhat Jalilov, Farkhod Narmuratov, Zulkhumor Jumayeva
CHEMISTRY AND CHEMICAL ENGINEERING
The purpose of this study is to determine the stability of the obtained coordination compounds of some d-metals with covalent immobilized sulfur-containing ligands. To achieve this goal, coordination compounds of copper (II), zinc (II), cadmium (II) and silver (I) ions with covalent immobilized sulfur-containing ligands - О,О-di- (2-aminoethyl) -dithiophosphate potassium - polyester matrix (KD2AEDTP-PEM), O,O-di- (2-aminoethyl) -dithiophosphate potassium - carbamide-formaldehyde matrix (KD2AEDTP-KFM). Studies were carried out to determine the acid-base properties of covalent-immobilized sulfur-containing ligands - KD2AEDTP-PEM, KD2AEDTP-KFM and the concentration stability of the obtained coordination compounds with ions of copper (II), zinc (II), cadmium (II), and silver (I). Based …
Synthesis And Spectroscopic Study Of Complex Compounds Mn(Ii), Co(Ii), Cu(Ii) And Zn With 5-Amino-2-Mercaptobenzimidazole,
2022
National University of Uzbekistan, Tashkent, Uzbekistan
Synthesis And Spectroscopic Study Of Complex Compounds Mn(Ii), Co(Ii), Cu(Ii) And Zn With 5-Amino-2-Mercaptobenzimidazole, Lobar Gapurova, Dilnoza Rakhmonova, Shakhnoza Kadirova
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of this work is to study the effect of the nature of electron-donor and electron-withdrawing substituents in the molecules of heterocyclic ligands, the nature of acidoligands and transition metal ions on the properties of the synthesized coordination compounds. A method for the synthesis of new complex compounds of Mn (II), Cо (II), Cu (II) and Zn with 5-amino-2-mercaptobenzimidazole has been developed and the composition and structure of the synthesized complex compounds have been studied using modern physicochemical methods, such as elemental, thermogravimetric, X-ray phase analysis and IR spectroscopy. Coordination competing donor centers, electronic and geometric structures of the …
Resistance Of Polystyrol Concrete To Dynamic Impact Loads,
2022
Tashkent Chemical-Technological Institute, Tashkent, Uzbekistan
Resistance Of Polystyrol Concrete To Dynamic Impact Loads, Natalya Dubovitskaya, Zamira Mukhamedbaeva, Abduvali Mukhamedbaev
CHEMISTRY AND CHEMICAL ENGINEERING
The aim of the study is to increase the resistance of polystyrene concrete obtained from recycled polystyrene to dynamic shock loads. The issues of resistance of polystyrene concrete to compression forces with increasing load are considered. It was found that in terms of impact resistance, polystyrene concrete can be classified as a viscous material capable of absorbing high energy of shock loads. It has been determined that when Na2SO4 is introduced as a hardening accelerator, polystyrene concrete samples can absorb an impact energy of more than 178.5 J.
Features Of The Formation Of The Coating Structure On Titanium-Based Alloys,
2022
Tashkent State Transport University, Tashkent, Uzbekistan
Features Of The Formation Of The Coating Structure On Titanium-Based Alloys, Uchkun Rakhimov, Nasiba Abduraimova, Yulbarskhon Mansurov
CHEMISTRY AND CHEMICAL ENGINEERING
Previously shown that coatings formed on titanium by plasma electrolytic oxidation (PEO) in an electrolyte with zirconium sulfate Zr(SO4)2 consisted of ZrO2 and TiO2 oxides, their surface layer is enriched with zirconium, they have good protective properties in chlorine-containing media. The resulting layers have a fairly regular distribution of relatively small pores, with a diameter of about 1 μm or less, on the surface. The composition and structure of PEO layers depend on both the composition of the electrolyte and the modes of formation. It is of scientific and practical interest to elucidate the effect …
Flexible Planar Metamaterials With Tunable Poisson’S Ratios,
2022
Rowan University
Flexible Planar Metamaterials With Tunable Poisson’S Ratios, Nicholas Pagliocca, Kazi Zahir Uddin, Ibnaj Anamika Anni, Chen Shen, George Youssef, Behrad Koohbor
Henry M. Rowan College of Engineering Departmental Research
This research reports on the design, fabrication, and multiscale mechanical characterization of flexible, planar mechanical metamaterials with tailorable mechanical properties. The tunable mechanical behavior of the structures is realized through the introduction of orthogonal perforations with different geometric features. Various configurations of the perforations lead to a wide range of Poisson’s ratios (from −0.8 to 0.4), load-bearing properties, and energy absorption capacities. The correlations between the configuration of the perforations and the auxetic response of the structures are highlighted through computational and experimental characterizations performed at multiple length scales. It is demonstrated that the local in-plane rotation of the solid …
Computational Investigation Of The Post-Yielding Behavior Of 3d-Printed Polymer Lattice Structures,
2022
Wright State University
Computational Investigation Of The Post-Yielding Behavior Of 3d-Printed Polymer Lattice Structures, Abdalsalam Fadeel, Hasanain Abdulhadi, Golam Newaz, Raghavan Srinivasan, Ahsan Mian
Mechanical and Materials Engineering Faculty Publications
Sandwich structures are widely used due to their light weight, high specific strength, and high specific energy absorption. Three-dimensional (3D) printing has recently been explored for creating the lattice cores of these sandwich structures. Experimental evaluation of the mechanical response of lattice cell structures (LCSs) is expensive in time and materials. As such, the finite element analysis (FEA) can be used to predict the mechanical behavior of LCSs with many different design variations more economically. Though there have been several reports on the use of FEA to develop models for predicting the post-yielding stages of 3D-printed LCSs, they are still …
Implementation Of Multiscale Mechanisms In Finite Element Analysis Of Active Composite Structures,
2022
The British University in Egypt
Implementation Of Multiscale Mechanisms In Finite Element Analysis Of Active Composite Structures, Amany G. Micheal Prof., Yehia Bahei El Din Prof.
Centre for Advanced Materials
Composite structures reinforced with electrically active filaments are modeled with the finite element method while the underlying thermo-electromechanical coupling phenomena and damage are taken into consideration. At the outset, structural analysis is performed with a general-purpose finite element code and a special material routine, which propagates local phenomena to the overall scale is utilized. The material routine implements an interactive, multiscale analysis, which provides seamless integration of the mechanics at the composite’s micro, macro, and structural length scales. The interface between the multiscale material routine and the finite element code is made through nonmechanical strains caused by damage, and piezo/pyro-electric …
Synergic Antitumor Effect Of Photodynamic Therapy And Chemotherapy Mediated By Nano Drug Delivery Systems,
2022
University of Guilan
Synergic Antitumor Effect Of Photodynamic Therapy And Chemotherapy Mediated By Nano Drug Delivery Systems, Mozhgan Aghajanzadeh, Mostafa Zamani, Fereshteh Rajabi Kouchi, Josh Eixenberger, Dorsa Shirini, David Estrada, Farhad Shirini
Materials Science and Engineering Faculty Publications and Presentations
This review provides a summary of recent progress in the development of different nano-platforms for the efficient synergistic effect between photodynamic therapy and chemotherapy. In particular, this review focuses on various methods in which photosensitizers and chemotherapeutic agents are co-delivered to the targeted tumor site. In many cases, the photosensitizers act as drug carriers, but this review, also covers different types of appropriate nanocarriers that aid in the delivery of photosensitizers to the tumor site. These nanocarriers include transition metal, silica and graphene-based materials, liposomes, dendrimers, polymers, metal–organic frameworks, nano emulsions, and biologically derived nanocarriers. Many studies have demonstrated various …
Thermoforming Process Effects On Structural Performance Of Carbon Fiber Reinforced Thermoplastic Composite Parts Through A Manufacturing To Response Pathway,
2022
Clemson University
Thermoforming Process Effects On Structural Performance Of Carbon Fiber Reinforced Thermoplastic Composite Parts Through A Manufacturing To Response Pathway, Madhura Limaye, Sai Aditya Pradeep, Anmol Kothari, Sushil Savla, Akshat Agha, Srikanth Pilla, Gang Li
Publications
Thermoforming process of thermoplastic-based continuous CFRP's offer a major advantage in reducing cycle times for large-scale productions, but it can also have a significant impact on the structural performance of the parts by inducing undesirable effects. This necessitates the development of an optimal manufacturing process that minimizes the introduction of undesirable factors in the structure and thereby achieves the targeted mechanical performance. This can be done by first establishing a relationship between the manufacturing process and mechanical performance and successively optimizing it to achieve the desired targets. The current study focuses on the former part, where a manufacturing-to-response (MTR) pathway …
Facile One-Step Hydrothermal Method For Nico2s4/Rgo Nanocomposite Synthesis For Efficient Hybrid Supercapacitor Electrodes,
2022
The British University in Egypt
Facile One-Step Hydrothermal Method For Nico2s4/Rgo Nanocomposite Synthesis For Efficient Hybrid Supercapacitor Electrodes, Ahmed Mysara, Sayed Y. Attia, Fouad I. El-Hosiny, M A. Sadek, Saad G. Mohamed, M M. Rashad
Nanotechnology Research Centre
Spinel nickel-cobalt sulfide (NiCo2S4) supported on reduced graphene oxide (rGO) was fabricated through a facile one-step hydrothermal method for energy storage applications. The distribution of the NiCo2S4 nanoparticles on the rGO surface was found to improve the supercapacitive performance of the assembled device. The NiCo2S4/rGO nanocomposite exhibits outstanding electrochemical behavior with a capacity (C)/specific capacitance (Cs) of 536 C g−1/1072 F g−1 at a current density of 1 A g−1. To further investigate the electrochemical behavior of the NiCo2S4/rGO nanocomposite, a hybrid supercapacitor (HSC) was constructed utilizing a NiCo2S4/rGO positive electrode and an activated carbon …
Nodule Formation On Copper Electrodeposits In The Rotating Cylinder Hull Cell,
2022
Missouri University of Science and Technology
Nodule Formation On Copper Electrodeposits In The Rotating Cylinder Hull Cell, Joseph Bauer, Michael S. Moats
Materials Science and Engineering Faculty Research & Creative Works
Nodulation formation during the electrolytic production of high-purity copper can lead to impurity entrapment and/or increased energy consumption. The rotating cylinder Hull cell (RCHC) was used to study copper nodule formation under mass transport conditions similar to industrial electrolytic copper production. The main advantage of the RCHC is that a wide range of current densities can be produced in a single experiment with well-defined mass transfer conditions. Visible nodule formation was observed at current densities greater than 250 A/m2, which is an iavg/iL ratio of 0.30 for a simulated conventional electrowinning cell. Statistical analysis was also performed using the Weibull …
Design And Fabrication Of Nanostructured Electrodes For Complementary Electrochemical And Photoelectrochemical Water Splitting,
2022
The American University in Cairo AUC
Design And Fabrication Of Nanostructured Electrodes For Complementary Electrochemical And Photoelectrochemical Water Splitting, Kholoud El Sayed Abousalem
Theses and Dissertations
Designing highly active, durable, and nonprecious electrodes for overall water splitting is of urgent scientific importance to realize sustainable hydrogen production. Accordingly, the need to search efficient energy production systems is of crucial necessity. In this thesis, two various systems for sustainable hydrogen production have been reported using electrochemical and photoelectrochemical pathways. In the first part of the thesis, electrochemical water splitting involving both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has been established. To this end, an innovative approach is demonstrated to synthesize flower-like 3D homogenous trimetallic Mn, Ni, Co phosphide catalysts directly on nickel foam via …
The Integrated Scheduling Of Flexible Manufacturing Systems Using Petri Net Modeling And Heuristic Searching,
2022
The American University in Cairo AUC
The Integrated Scheduling Of Flexible Manufacturing Systems Using Petri Net Modeling And Heuristic Searching, Mohammed Mohammed Magdy Mohammed
Archived Theses and Dissertations
No abstract provided.
