Engineering Commons^™

Modeling, Fabrication, And Optimization Of Niobium Cavities, Robert A. Schill Jr., Mohamed Trabia, William Culbreth

Transmutation Sciences Materials (TRP)

One of the key technologies for the deployment of accelerator driven transmutation systems is the accelerator itself. Elliptical superconducting niobium cavities are used to increase the efficiency of the high-power accelerators needed to support the transmutation mission.

One of the major sources of energy loss from a superconducting accelerator cavity is a process known as multiple impacting (or “multipacting”) of electrons. This phenomenon limits the maximum amount of energy and power that the niobium cavity can store. As a result, the maximum power available for accelerating the desired charge, as well as the overall performance of the accelerator is reduced. …

Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

There is an active international interest in lead-bismuth eutectic and similar liquid lead systems because of the relevance to the transmutation of nuclear waste, fast reactors, and spallation neutron sources.

Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. For lead bismuth eutectic (LBE) systems, there is an additional challenge because the corrosive behaviors of materials in LBE are not well understood. Most of the available information on LBE systems has come from the Russians, who have over 80 reactor-years experience with LBE coolant in their Alpha-class submarine reactors. The Russians found …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The primary objective of this task was to evaluate the effects of environmental and mechanical parameters on environment induced degradations of candidate target structural materials for applications in spallation-neutron-target systems. The materials selected for evaluation and characterization were martensitic stainless steels including Alloys HT-9, EP-823, and 422.

Accelerator-driven transmutation systems involve bombarding a target material such as molten lead-bismuth-eutectic (LBE) by a proton beam, thereby producing neutrons. The molten LBE target will be contained in a subsystem structural container made of a suitable material such as Alloys HT-9, EP-823, and 422. During the transmutation process, the target structural material may …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The corrosion of structural materials is a major concern for the use of lead-bismuth eutectic (LBE) systems for nuclear applications such as in transmuter targets or fast reactors. Corrosion in liquid metal systems can occur through various processes, including, for example, dissolution, formation of inter-metallic compounds at the interface, and penetration of liquid metal along grain boundaries. Predicting the rate of these processes depends on numerous system operational factors: temperature, system geometry, thermal gradients, solid and liquid compositions, and velocity of the liquid metal, to name a few. Corrosion, along with mechanical and/or hydraulic factors, often contributes to component failure. …

Development Of A Mechanistic Understanding Of High-Temperature Deformation Of Alloy Ep-823, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

During the transmutation process, a significant amount of heat can be generated in a molten lead-bismuth-eutectic (LBE) target, which will be contained in a subsystem structural container made of a suitable martensitic iron-chromium-molbdenum (Fe-Cr-Mo) stainless steel such as Alloys EP-823, HT-9 and 422. These materials will be subjected to high tensile stresses while they are in contact with the molten LBE at temperatures ranging between 400 and 600^oC. Therefore, a research program was conducted to evaluate the deformation characteristics of all three alloys in properly heat-treated conditions at temperatures relevant to the operating conditions.

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements, Ajit K. Roy

Transmutation Sciences Materials (TRP)

Engineering metals and alloys, when subjected to tensile loading beyond a limiting value, undergo plastic deformation resulting in lattice defects such as voids and dislocations. These imperfections interact with the crystal lattice, producing a higher state of internal stress, also known as residual stress, which can be associated with reduced ductility. Residual stresses are also generated in welded structures due to rapid solidification and resultant dissimilar metallurgical microstructures between the weld and the base metals. Development of these internal stresses is often influenced by incompatible permanent strain resulting from thermal and mechanical operations associated with welding and plastic deformation. These …

Fundamental And Applied Experimental Investigations Of Corrosion Of Steel By Lbe Under Controlled Conditions: Kinetics, Chemistry Morphology, And Surface Preparation, John Farley, Allen L. Johnson, Dale L. Perry

Transmutation Sciences Materials (TRP)

Advanced nuclear processes such the transmutation of nuclear waste, fast reactors, and spallation neutron sources require advanced materials systems to contain them. In particular, a successful program in nuclear waste processing that includes transmutation in accelerator-driven systems and fast reactors requires structural materials that are stable in the presence of non-moderating coolants. A prime candidate for such a coolant is Lead Bismuth Eutectic (LBE).

Materials in these systems must be able to tolerate high neutron fluxes, high temperatures, and chemical corrosion. For LBE systems, there is an additional challenge because the corrosive behaviors of materials in lead bismuth are not …

Effect Of Silicon Content On The Corrosion Resistance And Radiation- Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems, Ajit K. Roy

Transmutation Sciences Materials (TRP)

This task is focused on the evaluation of the effect of Si content on the corrosion behavior and radiation-induced embrittlement of martensitic steels having chemical compositions similar to that of modified 9Cr-1Mo steel. Numerous state-of-the-art experimental techniques are currently being planned to be employed to achieve the desired research goal.

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead Alloy Coolant Systems, Yitung Chen, Jinsuo Zhang, Huajun Chen, Jichun Li

Transmutation Sciences Materials (TRP)

In advanced nuclear energy systems, lead-alloys (e.g., lead, lead bismuth eutectic) emerge as strong candidates for transmutation and advanced reactor systems as nuclear coolants and high-power spallation neutron targets. However, it is widely recognized that corrosion of materials caused by lead-alloys presents a critical barrier to their industrial use. A few experimental research and development projects have been set up by different groups such as LANL to study the corrosion phenomena in their test facilities and to develop mitigation techniques and materials.

The goal of the proposed research project is to provide basic understanding of the protective oxide layer behaviors …

Corrosion Barrier Development For Lbe Corrosion Resistance, Biswajit Das

Transmutation Sciences Materials (TRP)

In the last quarter, a specialized sample holder was developed for the anodization of alumina on steel. In addition, it was determined that oxalic acid was the most appropriate acid for the anodization of these structures. The steel samples obtained from LANL were first cut into a number of pieces, each measuring 11mm x 8mm x 1.6mm, to allow multiple experiments. Special care was taken to ensure that the cutting process did not damage the samples. After investigation of several techniques, including laser cutting, the samples were cut using EDM wires. The cut steel pieces did not show any damage …

Corrosion Barrier Development For Lbe Corrosion Resistance: Quaterly Report, Biswajit Das

Transmutation Sciences Materials (TRP)

With the demonstration of formation of nanoporous alumina on steel and its good adhesion to substrate under thermal cycling, the next project task was to synthesize Chromium nanowires inside the alumina pores. During the previous quarter, a specialized sample holder was developed towards this goal. Various techniques for the deposition of Chromium were investigated and electro-deposition was determined to be the most suitable approach due to the large aspect ratio of the pores. A challenge in using electro-deposition for porous alumina is the potential sealing of the pores in aqueous solutions at higher temperatures. To avoid this problem, a search …

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das

Transmutation Sciences Materials (TRP)

Advanced transmutation systems require structural materials that are able to withstand high neutron fluxes, high thermal cycling, and high resistance to chemical corrosion. The current candidate materials for such structures are ferritic and ferritic-martensitic steels due to their strong resistance to swelling, good microstructural stability under irradiation, and the retention of adequate ductility at typical reactor operating temperatures.

In parallel, lead bismuth eutectic (LBE) has emerged as a potential spallation target material for efficient production of neutrons, as well as a coolant in the accelerator system. While LBE has excellent properties as a nuclear coolant, it is also highly corrosive …

Development, Fabrication And Study Of Fullerene-Containing Carbon Material (Fcc) For Immobilization Of Iodine: Progress Report #1-4, Michael Savopulo, Boris E. Burakov

Separations Campaign (TRP)

During current reporting period the experiments on synthesis of ceramic-like material by conversion of iodine-doped FCC and activated carbon to Si_xC_y have been completed. Cold pressed granules of FCC and activated carbon were rinsed in water-ethanol solution of tetraethoxysilane (TEOS), Si(OC₂H₅)₄, and then used for further synthesis. All new samples obtained have been studied using precise powder XRD analysis.

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 2nd Quarter Report, 2005, Clemens Heske

Fuels Campaign (TRP)

The goal of our project is to investigate interface corrosion processes in TRISO nuclear fuel particles. For this purpose, we are undertaking a detailed study of the interface formation between potential candidates for metallic fission products (Pd, Ag, and Cs), likely to diffuse from the kernel of the TRISO particles, with the TRISO coating layers. As a starting point, we are investigating the Pd/SiC interface and will extend our studies to Ag/SiC during our current summer research campaign. The experimental approach comprises the preparation of metal/SiC interfaces in-situ in our ultra-high vacuum system by electron-beam deposition. In order to understand …

Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske

Fuels Campaign (TRP)

The goal of this project is to elucidate the chemical bonding and interface formation of metal fission products with the coating materials used in state-of-the-art TRISO fuel particles. Particular emphasis is placed on an analysis of intermediate chemical phases at the interface, the intermixing/diffusion behavior, and the electronic interface structure as a function of material choice (metal and coating materials), temperature, and external stress. Furthermore, the chemical state of some of the metal fission products will be assessed.

This project studies the interface formation of Pd, Ag, and Cs with SiC and pyrolytic carbon. Using the TRISO coating materials (and …

Cryogenic Shape Memory Alloy Actuators For Spaceport Technologies: Materials Characterization And Prototype Testing, Jennifer Lemanski

Electronic Theses and Dissertations

Shape memory alloys (SMAs) possess the unique ability to change their shape by undergoing a solid-state phase transformation at a particular temperature. The shape change is associated with a large strain recovery as the material returns to its "remembered" shape. Their ability to act as both sensor and actuator has made them an attractive subject of study for numerous applications. SMAs have many characteristics which are advantageous in space-related applications, including generation of large forces associated with the strain recovery, smooth and controlled movements, large movement to weight ratio, high reliability, and spark-free operation. The objective of this work is …

Self-Assembled Supramolecular Structures Of Chiral Phospholipids: Structure, Mechanical Properties And Patterning, Nidhi Mahajan

Electronic Theses and Dissertations

Lipid molecule is well known natural building block to form different supramolecular structures with specific shape, size and functionality. In my thesis work, I have used DC8,9PC 1,2-bis(tricosa-10,12-dinoyl)-sn-glycero-3-phosphocholine), a type of chiral lipid to form the vesicles, tubules and ribbons . By using Atomic Force Microscope, I have studied the morphological features of these particular structures. Also, the mechanical properties of lipid tubules have been studied using AFM. Softlithography has been used to pattern the lipid vesicles and tubules into 2-dimensional and 3-dimensional ordered arrays. The structure of self-assembled hollow spherical vesicles was studied using AFM. The applications of soft …

Structural Evolution In Mechanically Alloyed Fe-Based Powder Systems, Umesh Patil

Electronic Theses and Dissertations

A systematic study of iron-based binary and multi-component alloys was undertaken to study the structural evolution in these powders as a function of milling time during mechanical alloying. Blended elemental powders of Fe100-XBX (where x = 5, 10, 17, 20, 22, 25, 37.5 and 50 at. %) and a bulk metallic glass (BMG) composition (Fe60Co8Zr10Mo5W2B15) were subjected to mechanical alloying in a SPEX 8000 mixer mill. X-ray diffraction technique was employed to study the phase evolution, crystallite size, lattice strain and also to determine the crystal structure(s) of the phases. Depending on the milling time, formation of supersaturated solid solutions, …

Self-Assembly Of Ge Quantum Dots On Si(100)- 2×1 By Pulsed Laser Deposition, M. S. Hegazy, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Self-assembled Ge quantum dots are grown on Si(100)- 2×1 by pulsed laser deposition. The growth is studied by in situ reflection high-energy electron diffraction and postdeposition atomic force microscopy. After the completion of the wetting layer, transient hut clusters, faceted by different planes, are observed. When the height of these clusters exceeded a certain value, the facets developed into {305} planes. Some of these huts become {305}-faceted pyramids as the film mean thickness was increased. With further thickness increase, dome clusters developed on the expense of these pyramids. © 2005 American Institute of Physics. [DOI: 10.1063/1.1949285]

Melting And Solidification Study Of Indium And Bismuth Nanocrystals Using Reflection High-Energy Electron Diffraction, Mohamed K. Zayed

Electrical & Computer Engineering Theses & Dissertations

As technology begins to utilize nanocrystals for many chemical, biological, medical, electrical, and optoelectrical applications, there is a growing need for an understanding of their fundamental properties. The study of melting and solidification of nanocrystals is of interest to fundamental understanding of the effect of reduced size and crystal shape on the solid-liquid phase transition. Melting and solidification of as-deposited and recrystallized indium and bismuth nanocrystals were studied using reflection high-energy electron diffraction (RHEED). The nanocrystals were thermally deposited on highly oriented 002-graphite substrate at different deposition temperatures. The growth dynamics of the nanocrystals was studied using in situ RHEED …

Modeling And Simulation To Investigate Effects Of Static Mixer, Carrier Gas, Temperature And Pressure On The Mixing Ratio Of Carbon Nanotubes Growth Reactors, David Addie Noye

Dissertations and Theses @ UNI

The problem of this study was to investigate the effects of static mixer, carrier gas, carrier gas inlet pressures, and reactor operating temperatures on the mixing ratio of carbon nanotube synthesizing reactor. The methodology included design of static mixers, mathematical modeling, and computer modeling and simulation experiments.

The simulation experiment was performed based on single phase carrier gas modeling due to difficulty and time for three phase fluid modeling. First only nitrogen carrier gas in addition to the other three factors under constant inlet flow velocity and inlet temperature was simulated. Secondly, the same procedure was applied to argon carrier …

High Temperature Heat Exchanger Project: Quarterly Progress Report October 1, 2004 Through December 31, 2004, Anthony Hechanova

Publications (NSTD)

UNLV hosted an NHI Systems Interface Meeting on Dec. 16 and a UNLVRF HTHX Kickoff Meeting on Dec. 17. The purpose of the meetings was to coordinate the FY05 research and development effort of the UNLV Research Foundation portion of the Nuclear Hydrogen Initiative among the DOE, national program technical directors and the UNLVRF collaborators. Collaborators also had the opportunity to discuss their research program plan and update their progress. It was decided that these type of collaboration meetings were very useful and they will be held quarterly at the various collaborator sites. The next meeting will be in March …

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead-Alloys Coolant Systems, Yitung Chen

Transmutation Sciences Materials (TRP)

The goal of the proposed research project is to provide basic understanding of the protective oxide layer behaviors and to develop oxide layer growth models of steels in non-isothermal lead-alloys (lead or lead-bismuth eutectic) coolant systems. It is widely recognized that the corrosiveness of the lead-alloys is a critical obstacle and challenge for which it can be safely used or applied in the nuclear coolant systems. Active oxygen control technique can promote the formation of the “self-healing” oxide films on the structural material surface, drastically reducing steel corrosion and coolant contamination. Many experiments of steels exposed to flowing lead-alloys have …

Oscillatory Interlayer Exchange Coupling In [Pt/Co]N/Nio/[Co/Pt]N Multilayers With Perpendicular Anisotropy: Dependence On Nio And Pt Layer Thicknesses, Z. Y. Liu, Lanping Yue, D. J. Keavney, Shireen Adenwalla

Materials Research Science and Engineering Center: Faculty Publications

Interlayer exchange coupling has been studied in a series of [Pt( t_Pt Å)/Co(4 Å)]n/NiO( t_NiO)/[Co(4 Å)/Pt( t_Pt Å)]_n multilayers with perpendicular anisotropy. The coupling oscillates between antiferromagnetic and ferromagnetic as a function of t_NiO with a period of ~5 Å, and the oscillatory behavior is related to the antiferromagnetic ordering of the NiO layer. This interlayer coupling between two Co/Pt multilayers is shown to occur domain by domain by magnetic force microscopy imaging. For the strongest antiferromagnetic coupling at t_NiO = 11 Å, an oscillation with a period of ~6 Å is superposed …

Quantum Entanglement Of Anisotropic Magnetic Nanodots, Ralph Skomski, Andrei Y. Istomin, Anthony F. Starace, David J. Sellmyer

Materials Research Science and Engineering Center: Faculty Publications

Anisotropic magnetic nanodots are promising physical realizations of qubits for quantum computing at finite temperature owing to their well-separated low-lying energy levels and scalability. The entanglement of two interacting magnetic nanodots is investigated and shown both analytically and numerically to be resonantly dependent on their interaction strength and on differences in their properties. These results provide criteria for fabricating and coupling magnetic nanodots so that their low-lying eigenstates can be significantly entangled.

The Effects Of Influent Debit On Hydrodynamic Characteristic Of Bojongsoang Facultative Pond: Without Wind Effects, Rositayanti Hadisoebroto, Suprihanto Notodarmojo

Makara Journal of Technology

The Effects of Influent Debit on Hydrodynamic Characteristic of Bojongsoang Facultative Pond: Without Wind Effects. The performance of facultative pond in Bojongsoang WWTP have reported to be unstable. One of the cause of the unstable performance is the hydrodynamic characteristics that not met the criterion. The improper hydrodynamic characteristics are included the existence of dead-zone, the short-circuiting, and the turbulence due to eddy current. The study was to analyze the effect of the influent debit variation on the hydrodynamic characteristics of the pond using mathematical model. The two-dimensional hydrodynamic model was built from two hydrodynamic equations which are continuity and …

Fuel Injection System For One Cylinder Motor Cycle Engine, Bambang Sugiarto

Makara Journal of Technology

Fuel Injection System for One Cylinder Motor Cycle Engine. Fuel injection has been developed for many years. But its common application is limited on car’s engine. With many reason fuel injection systems in motorcycle one cylinder engine has not been widely used yet. Fuel Injection System allows the amount of fuel, injected to be controlled appropriate to engine parameters such as engine speed, amount of air inducted to cylinder, temperature, for each cycle, over the entire engine operating conditions. This fuel injection research is done to find out the Volumetric Efficiency of the intake manifold system, the amount of fuel …

Influence Of Connection Placement To The Behavior Of Precast Concrete Exterior Beam-Column Joint, Elly Tjahjono, Heru Purnomo

Makara Journal of Technology

Influence of Connection Placement to the Behavior of Precast Concrete Exterior Beam-Column Joint. This paper presents an experimental study on the influence of connection placement to the behaviour of exterior beamcolumn joint of precast concrete structure under semi cyclic loading. Four half-scale beam-column specimens were investigated. Three beam-columns were jointed through connection that are placed in beam-column joint region and the forth is connected at the plastic hinge potensial region of the beam. Crack patterns, strength, stiffness and ductility of the test specimens have been evaluated. The test result indicated that all beam-column specimens show good ductility behavior.

Modelling And Simulation Of Packed Bed Catalytic Converter For Oxidation Of Soot In Diesel Powered Vehicles Flue Gas, Mohammad Nasikin, Praswasti P.D.K. Wulan, Vita Andrianty

Makara Journal of Technology

Modelling and Simulation of Packed Bed Catalytic Converter for Oxidation of Soot in Diesel Powered Vehicles Flue Gas. Diesel vehicle is used in Indonesia in very big number. This vehicle exhausts pollutants especially diesel soot that can be reduces by using a catalytic converter to convert the soot to CO2. To obtain the optimal dimension of catalytic converter it is needed a model that can represent the profile of soot weight, temperature and pressure along the catalytic converter. In this study, a model is developed for packed bed catalytic converter in an adiabatic condition based on a kinetic study that …

Optic Properties On Aggase2 Polycristal Fabrication, A. Harsono Soepardjo, I Dewa Made Janusetiawan

Makara Journal of Technology

Optic Properties on AgGaSe2 Polycristal Fabrication. Polycristal AgGaSe2, is compound (I-III-VI2) a semiconductor as basic material for thin film for solar cell. Polycristal was succesfully grown using Bridgmann Method, heated on sequential temperature treatment until 850°C and cooled down slowly until room temperature. Results observed were in the form of ingot (bars) with more or less 3 cm length and 13 mm in diameter. By using X-Ray Fefraction, composition obtained of each element (weight %) was Ag = 29,3996 %, Ga = 36,8123 % and Se = 30,29 % while using X-Ray Difraction lattice parameter obtained/calculated a = 4,4112 Å, …