Engineering Science and Materials Commons^™

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 …

Rheological Properties Of Modified Crumb Rubber Asphalt Binder And Selecting The Best Modified Binder Using Ahp Method, Mehdi Khalili, Kazem Jadidi, Moses Karakouzian, Serji Amirkhanian

Civil and Environmental Engineering and Construction Faculty Research

Crumb rubber modifier (CRM) is one of the most popular asphalt binder modifiers due to the economic benefits and desired physical and rheological properties of asphalt binders and asphalt mixes. This research focuses on evaluating the properties of rubber-modified asphalt binders and selecting the best modified binder. The modified binders were produced by blending virgin binders with CRM at various contents of different gradations, and different methods of grinding. CRM made through ambient and cryogenic grinding methods with two gradation sizes were produced and tested. Three different virgin binders from two sources were obtained and used. The Analytic Hierarchy Process …

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.

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, …

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

LSU 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 …

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

LSU 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 …

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 …

Microstructural Effects On Photocatalytic Performance In Ag3po4/Bi2moo6 Z-Scheme Photocatalyst Systems, Kaleab Mengesha Ayalew

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the world population continues to grow and access to modern industry become increasingly common, humanity finds itself amid an environmental and energy crisis. Natural resources, such as clean water are getting scarce. Currently, the development of high efficiency, green energy sources, and eco-friendly methods for water treatment have become a nonelective task. As a result, photocatalysis, as one of the most promising technologies in utilizing solar energy and pollutant removal, has attracted considerable attention.

However, the practical application of photocatalysis is still elusive because of the difficulty of finding an individual material that can satisfy all the requirements for …

Preparation Of Chitosan-Polyethylene Oxide-Colocasia Esculenta Flour Nanofibers Using Electrospinning Method, Riesca Ayu Kusuma Wardhani, Lia Asri, Muhamad Nasir, Bambang Sunendar Purwasasmita

Journal of Mechanical Engineering Science and Technology (JMEST)

Nanofibers have been prepared from the mixture of chitosan, polyethylene oxide (PEO) and Colocasia esculenta flour (CE flour) by using the electrospinning method. Two different nanofibers were formulated, containing chitosan-PEO and chitosan-PEO-CE flour. The higher concentration of PEO (3%chitosan-6%PEO) (w/v) resulted in more uniform chitosan-PEO electrospun nanofibers without beads. Chitosan-PEO-CE flour was prepared by addition of colloidal CE flour into the solution containing 3%chitosan-6%PEO with variation of the CE flour concentration of 5, 15 and 25% (w/v). Scanning Electron Microscopy demonstrated that the average diameter of chitosan-PEO nanofibers was 128±41 nm, whereas the diameter of chitosan-PEO-CE flour nanofibers was 159±45 …