Engineering Commons^™

Preface To Special Issue Of Electrochemical Reduction Of Carbon Dioxide, Qing Li, Min Liu

Journal of Electrochemistry

No abstract provided.

Statuses, Challenges And Strategies In The Development Of Low-Temperature Carbon Dioxide Electroreduction Technology, Xu-Rui Zhang, Xiao-Lin Shao, Jin Yi, Yu-Yu Liu, Jiu-Jun Zhang

Journal of Electrochemistry

Low-temperature carbon dioxide (CO₂) electrochemical reduction technology is a hotspot for research and development in recent years as a way to reduce the negative impact of CO₂ on the environment and to generate energy storage through converting electricity to low-carbon fuels. Although basic research on catalyst activity, product selectivity, and reaction mechanism has been widely reported, the design and practicality of catalytic stability and corresponding electrochemical reactor systems have not been given sufficient attention and systematic development. In this paper, two important factors affecting the development of CO₂ electrochemical reduction technology in low temperature aqueous solution …

Effect Of Morphology Of Fe-N Codoped Carbon Nanomaterial On Electrochemical Reduction Reactions, Er-Ling Li, Fa Yang, Ming-Bo Ruan, Ping Song, Wei-Lin Xu

Journal of Electrochemistry

Graphene nanosheets (GS) and carbon nanotubes have been considered as good catalysts candidates for applications in energy conversion and storage. However, hybrids of GS and carbon nanotubes are always formed in transition metal-based nitrogen-doped system, making the system quite complex for exploring the structure-activity relationship. To prepare the catalysts with desired species controllably, we try to adjust the outcomes with the effect of nitrogen on the growth of carbon nanotubes. In this work, a series of Fe-N co-doped carbon hybrid catalysts containing N-doped GS or hybrids of GS/bamboo carbon nanotubes (BCNTs) or BCNTs were obtained with one-step pyrolyzed method. To …

Single-Layer Oxygen Deficiency Δ-Mno2 For Electrochemical Co2 Reduction, Yue-Feng Zhang, Jian-Jun Liu, Zeng-Xi Wei, Xin-Xin Tian, Jian-Min Ma

Journal of Electrochemistry

Manganese dioxide (MnO₂) has been widely used in catalysis. In addition, since the defect engineering can change the electronic properties of the catalyst, here we have systematically studied electrocatalytic carbon dioxide reduction reaction (CO₂RR) on δ-MnO₂ with and without oxygen deficiency, denoted as Ov-MnO₂ and MnO₂, respectively. We calculate the electronic properties and the intermediate of free energy for MnO₂ and Ov-MnO₂ with the help of spin-polarized density functional theory. By analyzing this result, we can find that the introduction of defects change the δ-MnO₂ from semiconducting properties …

Copper-Based Compounds For Electrochemical Reduction Of Carbon Dioxide, Fan Yang, Pei-Lin Deng, You-Jia Han, Pan Jing, Bao-Yu Xia

Journal of Electrochemistry

The electrochemical reduction of carbon dioxide (CO₂) to useful chemicals and fuels has attracted enormous interest since the deteriorating global warming and energy shortage problems resulted from ever-increasing CO₂ emission. Designing efficient catalysts is of capital significance to realize the efficient and selective conversion of CO₂. Among various catalysts explored, copper-based compounds have promising potentials with acceptable efficiency for hydrocarbon production. Herein, recent advances on copper-based materials are summarized for electrochemical CO₂ conversion. We intend to include the dimensional structure, different forms (alloy, oxide) and molecular catalysts in copper-based catalysts. Moreover, the reaction mechanisms …

Recent Progress In Copper-Based Catalysts For Electrochemical Co2 Reduction, Wen Lei, Wei-Ping Xiao, De-Li Wang

Journal of Electrochemistry

As the situation of energy crisis and environmental pollution become more and more serious, the electrochemical reduction of carbon dioxide (CO₂) has attracted lots of attention because of its multiple meanings such as environment, resources and economic benefits. In this paper, the state of the art electrochemical reduction of CO₂ in aqueous solution is reviewed, and the latest research progress in Cu-based catalysts with different structures and morphologies is summarized. In the end, the application prospects, opportunities and challenges of Cu-based materials are briefly presented to provide an outlook for future research directions.

Artificial Intelligence Based Wrist Fracture Classification, Dineep Thomas

LSU Master's Theses

The problem of predicting wrist fractures from X-rays using Artificial Intelligence (AI) methods is addressed. Wrist fractures are the most commonly misdiagnosed fractures because of the complex anatomical structure of the wrist bone which includes several different bones. This research provides a predictive solution to automate the process of wrist fracture classifications and outlines a visualization technique to identify the probable location of the fractured region on the X-rays. This thesis describes a deep learning based approach for wrist fracture classification. Deep convolutional neural network (CNN) based models have been used for wrist fracture classification by combining different optimization techniques. …

Experimental Evaluation Of Self-Expandable Metallic Tracheobronchial Stents, Yanli Wang, Pengfei Dong, Jingyao Ke, Xiang Shen, Zongming Li, Kewei Ren, Xinwei Han, Linxia Gu

Department of Mechanical and Materials Engineering: Faculty Publications

The self-expandable metallic stents have been widely used in tracheobronchial obstruction or fistulation, including the J-shaped and Y-shaped stents, named after the shape of the branch-stem junction of the stent. However, there is scarce data on the mechanical performance of these tracheobronchial stents, which is essential for optimal stent implantation. In this work, eight self-expandable metallic tracheobronchial stents in three types (i.e., straight, J-shaped, and Y-shaped), with or without cover, were characterized. The compression resistance of the stems was investigated through both compression and indentation tests. The bending resistance of the branches in the J-shaped and Y-shaped stents was assessed …

Interface Effects On He Ion Irradiation In Nanostructured Materials, Wenfan Yang, Jingyu Pang, Shijian Zheng, Jian Wang, Xinghang Zhang, Xiuliang Ma

Department of Mechanical and Materials Engineering: Faculty Publications

In advanced fission and fusion reactors, structural materials suffer from high dose irradiation by energetic particles and are subject to severe microstructure damage. He atoms, as a byproduct of the (n) transmutation reaction, could accumulate to form deleterious cavities, which accelerate radiation-induced embrittlement, swelling and surface deterioration, ultimately degrade the service lifetime of reactor materials. Extensive studies have been performed to explore the strategies that can mitigate He ion irradiation damage. Recently, nanostructured materials have received broad attention because they contain abundant interfaces that are efficient sinks for radiation-induced defects. In this review, we summarize and analyze the current understandings …

Modeling Of Theflow Regimes Of Water-Coal Fuel Slurries With Complex Reology In Cylindrical Pipes, Ja.D. Hodzhaev, Sh.A. Kasymov

Journal of Tashkent Institute of Railway Engineers

The article deals the flow regimes with regard to the complex flow rheology of highly concentrated water-coal fuel slurries (WCS). It has been established that during the WCS flow through cylindrical pipes the flow mode is disturbed, which is due to the mutual influence of the geometric dimensions and flow parameters of the suspension when it is burned in the combustion chambers of power plants

On The Formation Of The Variational Equation Of Motion And Boundary Value Problems Of Thin-Walled Axisymmetric Shell Structures, A. Abdusattarov, F.E. Abduqodirov, N.H. Sabirov

Journal of Tashkent Institute of Railway Engineers

The article deals, on the basis of the Hamilton-Ostrogradsky variational principle, a system of differential equations of motion of axisymmetric shell structures with the corresponding boundary and initial conditions is derived. The boundary problem for cylindrical and spherical shell structures is formulated

Calculation Of The Wagon Motion Velocation On The Whole Protection Of The Profile Of The Way With Different Clothes Of The Sorting Hill, Kh.Kh. Djalilov

Journal of Tashkent Institute of Railway Engineers

In this article has been calculated the velocity of the wagon’s movement in various sites of a hump yard, based on the formula led on the basis of the theorem of changing of kinetic energy for not free material point in a final form. Results of the calculations are noticed that on the intermediate site of a hump yard to a dividing arrow the relative error of calculation is equal to 10.3%, on the site of an arrow zone of a hump yard of the second dividing arrow - δv6с2 ≈ 9.0%, on the site of the first sorting way …

On The Construction Of Canonical Systems Of Equations For Cylindrical And Spherical Shell Structures, A. Abdusattarov, F.E. Abduqodirov

Journal of Tashkent Institute of Railway Engineers

In this article is given the construction of canonical systems, the equation of motion for axisymmetric shell structures, as well as for cylindrical and spherical shells

Research Of Surface Condition Of The Rails Rolling On Sections Of High-Speed And High-Speed Train Traffic, E.B. Abdualiyev

Journal of Tashkent Institute of Railway Engineers

In this article, the analysis of intensity of the pulse roughness’s arising on a surface of rolling of heads of rails on a site of high-speed movement of trains is carried out.

The Movement Of Trains As A Source Of Seismic Waves Impact On The Upper Structure Of The Track And The Roadbed Of Railways, A.H. Abdujabarov, P. A. Begmatov, M. Mehmonov

Journal of Tashkent Institute of Railway Engineers

On the basis of theoretical and experimental scientific research, the substantiation of the similarity of the impact of seismic forces and the movement of rolling stock on the engineering structures of Railways is obtained.

About Movements Of The Carriage On The Profile Hump In A Gravity Yard, Sh.B. Djabbarov

Journal of Tashkent Institute of Railway Engineers

The article noted that in the existing methods of calculation of hump in a gravity yards the speed of the car at the braking position is determined by the formula speed of free fall of bodies given the inertia in the rotating parts of the car. Thus assume that in areas of deceleration occur rotation of the wheels of the car, that is incorrect. In it mathematical expressions and examples of calculations proved that the high-speed sections slides occur the rolling of the wheels of wheel pairs without slipping.

On The Application Of Information Technology For The Development Of Software For Automation The Modeling Process Of Wagons At Wagon Enterprises Jsc "O'Zbekiston Temir Yo'llari", V.P. Bubnov, Sh. Kh. Sultonov

Journal of Tashkent Institute of Railway Engineers

The report presents a functional diagram of the developed software for calculating the values of loads acting on the wagon body. The stages of development and the main modules of a software product that implements mathematical calculations are defined. The issues of the software implementation of the presented algorithms using the object-oriented programming language C # are discussed. The performed engineering analysis using the values of loads obtained using the developed software is given. The developed program in C # language with the use of the integrated Visual Studio environment allows to increase the accuracy and reduce the time for …

Features Of Thermal Processing Of Instrumental Alloyed Steels, F.R. Norkhudjayev, A.A. Mukhamedov, D.M. Ergashev

Journal of Tashkent Institute of Railway Engineers

In work, the most preferred heat treatment scheme has been determined on the basis of the analysis of various heat treatment schemes for alloyed tool steels, which the excludes the possibility of restoring the original grain structure and retains the possibility of studying the increased material defectiveness acquired during primary hardening.

To The Movement Of The Car On The Site Of The First Brake Hump Yard Of Positions, Sh.U. Saidivaliyev

Journal of Tashkent Institute of Railway Engineers

In the article using the analytical formulas derived from the application of the basic law of dynamics for non-ideal connections (Dalembert principle), the kinematic parameters of the car’s motion (acceleration, time, braking path) were calculated in the deceleration zone at the site of the first brake position of the hump yard

Boolean Complement Method For Combinational Circuits Testing Using Binary Separable Codes, A.H. Efanov

Journal of Tashkent Institute of Railway Engineers

The concurrent error-detection systems basic structural diagrams based on the check bits calculation and on the logical addition basis are described. A hybrid block diagram is presented in which the part of the diagnostics object outputs is transformed. The conditions for the use of binary separable codes for their use in the concurrent error-detection systems organization according to the method of logical addition are established.

Self-Assembly Of Conducting Polymer Nano- And Microstructures For Energy Storage, Luciano Matteo Santino

Arts & Sciences Electronic Theses and Dissertations

Plastics are materials composed of many long chains of molecules with repeating subunits; strong interactions between neighboring molecules lead to the material used throughout the world. Plastics are commonly thought to be insulating, in stark contrast to the conductivity of metals. However, certain polymer structures were discovered to exhibit semiconducting properties, the subject of the Nobel Prize in Chemistry in 2000. Conducting polymers have a unique molecular structure with an electronically conjugated backbone, allowing electrons to freely travel both across the chain and in between chains. This work focuses on controlling the kinetics of the reaction between the vapors of …

The Linc Complex, Mechanotransduction, And Mesenchymal Stem Cell Function And Fate, Tasneem Bouzid, Eunju Kim, Brandon D. Riehl, Amir Monemian Esfahani, Jordan Rosebohm, Ruiguo Yang, Bin Duan, Jung Yul Lim

Department of Mechanical and Materials Engineering: Faculty Publications

Mesenchymal stem cells (MSCs) show tremendous promise as a cell source for tissue engineering and regenerative medicine, and are understood to be mechanosensitive to external mechanical environments. In recent years, increasing evidence points to nuclear envelope proteins as a key player in sensing and relaying mechanical signals in MSCs to modulate cellular form, function, and differentiation. Of particular interest is the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex that includes nesprin and SUN. In this review, the way in which cells can sense external mechanical environments through an intact nuclear envelope and LINC complex proteins will be briefly described. Then, …

General Nonlinear-Material Elasticity In Classical One-Dimensional Solid Mechanics, Ronald Joseph Giardina Jr

University of New Orleans Theses and Dissertations

We will create a class of generalized ellipses and explore their ability to define a distance on a space and generate continuous, periodic functions. Connections between these continuous, periodic functions and the generalizations of trigonometric functions known in the literature shall be established along with connections between these generalized ellipses and some spectrahedral projections onto the plane, more specifically the well-known multifocal ellipses. The superellipse, or Lam\'{e} curve, will be a special case of the generalized ellipse. Applications of these generalized ellipses shall be explored with regards to some one-dimensional systems of classical mechanics. We will adopt the Ramberg-Osgood relation …

Development Of Experimental And Finite Element Models To Show Size Effects In The Forming Of Thin Sheet Metals, Jeffrey D. Morris

University of New Orleans Theses and Dissertations

Abstract

An experimental method was developed that demonstrated the size effects in forming thin sheet metals, and a finite element model was developed to predict the effects demonstrated by the experiment. A universal testing machine (UTM) was used to form aluminum and copper of varying thicknesses (less than 1mm) into a hemispherical dome. A stereolithography additive manufacturing technology was used to fabricate the punch and die from a UV curing resin. There was agreement between the experimental and numerical models. The results showed that geometric size effects were significant for both materials, and these effects increased as the thickness of …

Cellulose Nanofibrils (Cnf) For Textile Applications: Production Of Neat Cnf Filaments And Reinforcement Of Natural Fiber Yarns, Shokoofeh Ghasemi

Electronic Theses and Dissertations

Being the most abundant natural polymer on earth, cellulose materials have been used in many different applications. Cellulose nanofibrils (CNF) are a relatively new group of lignocellulose resource-based nanomaterials and have been the topic of many research efforts in wood products and material science field over the recent years. Using CNF in textile applications is one way to diversify product portfolio of these materials as they contain nanoscale fibrils with high mechanical properties which can fulfil textile industry’s demand for strong natural fibers. Considering that CNF is a wood-based cellulosic material in the form of water suspension, in order to …

Diseño Y Construcción De Un Fotorreactor, Para La Activación Y Evaluación De Desempeño De Concreto Fotocatalítico, Diana Carolina Ramirez Pinto, Erika Alexandra Wesso Amaya

Ingeniería Civil

No abstract provided.

On The Measurement Of Energy Dissipation Of Adhered Cells With The Quartz Microbalance With Dissipation Monitoring, Amir Monemian Esfahani, Weiwei Zhao, Jennifer Y. Chen, Changjin Huang, Ning Xi, Jun Xi, Ruiguo Yang

Department of Mechanical and Materials Engineering: Faculty Publications

We previously reported the finding of a linear correlation between the change of energy dissipation (ΔD) of adhered cells measured with the quartz crystal microbalance with dissipation monitoring (QCM-D) and the level of focal adhesions of the cells. To account for this correlation, we have developed a theoretical framework for assessing the ΔD-response of adhered cells. We rationalized that the mechanical energy of an oscillating QCM-D sensor coupled with a cell monolayer is dissipated through three main processes: the interfacial friction through the dynamic restructuring (formation and rupture) of cell-extracellular matrix (ECM) bonds, the interfacial viscous damping by the liquid …

Optical Direct Detection Of Thermal Vibrations Of Ultralow Stiffness Micro-Nano Structures., Sri Sukanta Chowdhury

Electronic Theses and Dissertations

A direct detection optical vibrometer is constructed around an 850 nm laser and a quadrant photodetector (QPD). The limit of detection is 0.2 fW which corresponds to a minimum amplitude of 0.1 Å. The vibrometer is used to measure the thermal vibration spectra of low stiffness micromechanical structures have nanometer features. One structure measured is a cantilevered 30 μm diameter glass fiber. Vibration amplitudes as low as 1.1 Å are measured. The thermal vibration spectra show fundamental resonances at 80-250 Hz and a signal to noise ratio (SNR) of 23-55 dB. Young’s modulus of glass in the cantilevers, estimated from …

Observations Of Shear Stress Effects On Staphylococcus Aureus Biofilm Formation, Erica Sherman, Kenneth W. Bayles, Derek Moormeir, Jennifer Endres, Timothy Wei

Department of Mechanical and Materials Engineering: Faculty Publications

Staphylococcus aureus bacteria form biofilms and distinctive microcolony or “tower” structures that facilitate their ability to tolerate antibiotic treatment and to spread within the human body. The formation of microcolonies, which break off, get carried downstream, and serve to initiate biofilms in other parts of the body, is of particular interest here. It is known that flow conditions play a role in the development, dispersion, and propagation of biofilms in general. The influence of flow on microcolony formation and, ultimately, what factors lead to microcolony development are, however, not well understood. The hypothesis being examined is that microcolony structures form …

Modeling Thermal And Mechanical Cancellation Of Residual Stress From Hybrid Additive Manufacturing By Laser Peening, Guru Madireddy, Chao Li, Jingfu Liu, Michael P. Sealy

Department of Mechanical and Materials Engineering: Faculty Publications

Additive manufacturing (AM) of metals often results in parts with unfavorable mechanical properties. Laser peening (LP) is a high strain rate mechanical surface treatment that hammers a workpiece and induces favorable mechanical properties. Peening strain hardens a surface and imparts compressive residual stresses improving the mechanical properties of a material. This work investigates the role of LP on layer-by-layer processing of 3D printed metals using finite element analysis. The objective is to understand temporal and spatial residual stress development after thermal and mechanical cancellation caused by cyclically coupling printing and peening. Results indicate layer peening frequency is a critical process …