Materials Science and Engineering Commons^™

Effect Of Silicon Content On The Corrosion Resistance And Radiation-Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems: Quarterly Progress Report (November 2004 – January 2005), Ajit K. Roy

Transmutation Sciences Materials (TRP)

This proposal is intended to study the effect of Si content not only on the corrosion resistance but also on the radiation-induced embrittlement of martensitic stainless steels. The susceptibility of these alloys with different Si content to stress corrosion cracking, general corrosion and localized corrosion will be evaluated in the molten LBE and aqueous environments of different pH values using state-of-the-art testing techniques. Testing in the aqueous media is intended to develop baseline data for comparison purpose. Radiation-induced embrittlement of these alloys will initially be studied by irradiating the test specimens with bremmstrahlung gamma radiation from 20-40 MeV electron beams …

Thermochemistry Of La 1-Sr Xfeo 3-Δ Solid Solutions (0.0 ≤ X ≤ 1.0, 0.0 ≤ Δ ≤ 0.5), Jihong Cheng, Alexandra Navrotsky, Xiao Dong Zhou, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

A series of compounds with the general formula La_1-xSr_xFeO_3-δ have been synthesized in the complete solid solution range 0.0 ≤ x ≤ 1.0 and 0.0 ≤ δ ≤ 0.5 with a variety of heat treatments. High temperature drops solution calorimetry in molten 2PbO·B₂O₃ at 702 °C was performed to determine their enthalpies of formation from oxides at room temperature. the enthalpy of oxidation involved in the reaction 2Fe^X_Fe + V _O^•• + 0.5O 2(g) = 2Fe _Fe^• + O _O^X is independent of oxygen nonstoichiometry in each …

An Exafs Investigation Of Rare-Earth Local Environment In Ultraphosphate Glasses, M. Karabulut, E. Metwalli, A. K. Wittenauer, Richard K. Brow, G. K. Marasinghe, C. H. Booth, J. J. Bucher, D. K. Shuh

Materials Science and Engineering Faculty Research & Creative Works

The local structures around rare-earth ions in rare-earth ultra phosphate glasses (nominally 15RE₂O₃-85P₂O₅, mol%, RE = Nd, Sm, Gd, Ho, and Er) and metaphosphate glasses (nominally 25RE₂O₃-75P₂O₅, mol%, RE = Nd, Gd, and Er) have been studied by extended X-ray absorption fine structure spectroscopy (EXAFS) at the respective rare-earth LIII edges. the RE-O distance decreases with increasing atomic number of the rare-earth ion for both ultra and metaphosphate glasses. on average, RE-O distances for metaphosphate glasses are shorter than those for ultra phosphate glasses …

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Fourth Quarterly Report, Robert A. Schill Jr., Mohamed Trabia, William Culbreth

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for niobium superconducting cavities. The surface preparation can significantly affect the secondary electron emission yields. Such yields are used in design codes. Current codes use values obtained from niobium samples cleaned by a different means at temperatures other than the operating temperature. Secondary electron emission studies on LANL surface-cleaned niobium are conducted with preliminary data presented in this report at room temperature. Soon studies will be …

Sub-Surface Corrosion Research On Rock Bolt System, Perforated Ss Sheets And Steel Sets For The Yucca Mountain Repository — Quarterly Technical Report No. 3, Dhanesh Chandra, Jaak J.K. Daemen

Publications (YM)

This report encompasses the work done for third quarter in accordance to cooperative agreement of UCCSN for the Task 019 “Subsurface Corrosion Research on Rock Bolt System, Perforated SS Sheets and Steel Sets for the Yucca Mountain Repository”, the objective of which was proposed earlier, to conduct corrosion research and predict the durability of rockbolts and other underground metallic roof supports. We have recently started working on oxidation tests using Thermogravimetric Analyzer (TGA), stress corrosion cracking/hydrogen embrittlement studies on rock bolts, other support materials including bench mark materials. In this quarterly report we will discuss “Dry” oxidation of steels and …

Catalytic Conversion Of Hydrocarbons To Hydrogen And High-Value Carbon, Naresh Shah, Devadas Panjala, Gerald P. Huffman

Chemical and Materials Engineering Faculty Patents

The present invention provides novel catalysts for accomplishing catalytic decomposition of undiluted light hydrocarbons to a hydrogen product, and methods for preparing such catalysts. In one aspect, a method is provided for preparing a catalyst by admixing an aqueous solution of an iron salt, at least one additional catalyst metal salt, and a suitable oxide substrate support, and precipitating metal oxyhydroxides onto the substrate support. An incipient wetness method, comprising addition of aqueous solutions of metal salts to a dry oxide substrate support, extruding the resulting paste to pellet form, and calcining the pellets in air is also discloses. In …

Fabrication And Composition Control Of Niti Shape Memory Thin Films For Microactuators, Richard N. Savage, David J. Getchel

Materials Engineering

Microactuators fabricated with NiTi thin films take advantage of this material’s large energy density (~5-10 joules/cm3) and high strain recovery (~8%). Microelectromechanical Systems (MEMS) devices designed with these actuators can serve as biosensors, micro-fluidic pumps or optical switches. However, the fundamental mechanical properties stemming from the crystalline structure of these shape memory NiTi films have not been fully characterized with MEMS scale test structures. Understanding the relationship of crystalline structure, film stoichiometry, and phase transformation temperatures is crucial when designing a MEMS actuator. In addition, force displacement curves for both the martensite and austenite phases of NiTi are necessary to …

Ballistic Anisotropic Magnetoresistance, Julian P. Velev, Renat F. Sabirianov, Sitaram Jaswal, Evgeny Y. Tsymbal

Materials Research Science and Engineering Center: Faculty Publications

Electronic transport in ferromagnetic ballistic conductors is predicted to exhibit ballistic anisotropic magnetoresistance—a change in the ballistic conductance with the direction of magnetization. This phenomenon originates from the effect of the spin-orbit interaction on the electronic band structure which leads to a change in the number of bands crossing the Fermi energy when the magnetization direction changes. We illustrate the significance of this phenomenon by performing ab initio calculations of the ballistic conductance in ferromagnetic Ni and Fe nanowires which display a sizable ballistic anisotropic magnetoresistance when magnetization changes direction from parallel to perpendicular to the wire axis.

3d Modelling With Linear Approaches Using Geometric Primitives, Mochammad Zuliansyah

Makara Journal of Technology

In this paper, we study linear approaches for 3D model acquisition from non-calibrated images. First, the intrinsic and extrinsic camera calibration is taken into consideration. In particular, we study the use of a specific calibration primitive: the parallelepiped. Parallelepipeds are frequently present in man-made environments and naturally encode the affine structure of the scene. Any information about their euclidean structure (angles or ratios of edge lengths), possibly combined with information about camera parameters is useful to obtain the euclidean reconstruction. We propose an elegant formalism to incorporate such information, in which camera parameters are dual to parallelepiped parameters, i.e. any …

Carbon Nanotubes And Tungsten Oxide Nanorods: Synthesis And Applications, Bing Xiao

Electrical & Computer Engineering Theses & Dissertations

Synthesis and applications of two types of one-dimensional nanomaterials, carbon nanotubes (CNTs) and tungsten oxide nanorods, are investigated in this dissertation. Multi-walled CNTs have been successfully synthesized using two types of chemical vapor deposition (CVD) methods: microwave plasma enhanced CVD and atmospheric pressure thermal CVD. CNTs and their synthesis processes are characterized with various analysis techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and optical emission spectroscopy. Ultra-thin and high quality multi-walled CNTs are discovered in CNT films produced by MPCVD, which exhibit good field emission performance that is found to be dependent on the synthesis …

Tensile Properties Of Martensitic Stainless Steels At Elevated Temperatures, Ajit K. Roy, Srinivasarao R. Kukatla, Bhagath Yarlagadda, V. N. Potluri, Martin Lewis, Brendan O'Toole

Mechanical Engineering Faculty Research

Tensile properties of quenched and tempered martensitic alloys EP-823, HT-9, and 422 were evaluated at temperatures ranging from ambient to 600 °C as a function of three different tempering times. The results indicated that the yield strength, ultimate tensile strength, and the failure strength were gradually reduced with increasing temperature. The ductility parameters were enhanced at elevated temperatures due to increased plastic flow. However, the tempering time did not significantly influence these properties. The evaluation of the fracture surfaces by scanning electron microscopy revealed reduced cracking and dimpled microstructures, indicating enhanced ductility at higher testing temperatures.

Residual Stress Characterization In Structural Materials By Destructive And Nondestructive Techniques, Ajit K. Roy, Anand Venkatesh, Vikram Marthandam, Satish Dronavalli, Douglas P. Wells, Ronald Rogge

Mechanical Engineering Faculty Research

Transmutation of nuclear waste is currently being considered to transform long-lived isotopes to species with relatively short half-lives and reduced radioactivity through capture and decay of minor actinides and fission products. This process is intended for geologic disposal of spent nuclear fuels for shorter durations in the proposed Yucca Mountain repository. The molten lead-bismuth-eutectic will be used as a target and coolant during transmutation, which will be contained in a subsystem vessel made from materials such as austenitic (304L) and martensitic (EP-823 and HT-9) stainless steels. The structural materials used in this vessel will be subjected to welding operations and …

Fundamental And Applied Experimental Investigations Of Corrosion Of Steel By Lbe Under Controlled Conditions: Kinetics, Chemistry, Morphology, And Surface Preparation: Quarterly Report (January 2005-April 2005), Allen L. Johnson, John Farley, Dale L. Perry

Transmutation Sciences Materials (TRP)

This project has four components:

• The fabrication of a materials test apparatus with unique capabilities,
• Comparative studies of steel corrosion under gas phase conditions comparable to the Lead Bismuth Eutectic (LBE) oxygen control conditions,
• Isotope labeling studies, and
• Collaborative efforts with other workers in the field.

Summary of accomplishments:

• Started occupation of the High Temperature Materials Experimental Facility.
• Presented a paper at the meeting of the American Chemical Society in San Diego in March 13-17.
• Currently reviving the ion beam for implantation experiments.
• Currently analyzing 38 steel samples from the DELTA loop from LANL.

Synthesis Dibenzyl Terephthalate Through Depolimerization Of Poly (Ethylene Terephthalate) As Alternative Of Waste Plastics Recycling, Suwardi Suwardi, Crys Fajar Partana, Agus Salim, Dyah Anitasari

Makara Journal of Technology

Synthesis Dibenzyl Terephthalate Through Depolimerization of Poly(ethylene terephthalate) as Alternative of Waste Plastics Recycling. Synthesis dibenzyl terephathalate were done through PET degradation by refluxing in benzyl alcohol at 145oC temperature for 20, 24, and 28 hours in the presence of zinc acetate catalyst. The result of degradation was purified by recristalization in methanol and then melting point (mp), FTIR, 1H NMR spectra, and TLC spot were determined. The melting point of product degradation for 28 hours was 98-99 oC. Based FTIR spectra known that compunds of product degradation have OH, C=O, C-O, CH, monosubstituted benzene, disubstituted benzene groups, while on …

Dipole Magnetization Effect To Kerosene Characteristics, Mochamad Chalid, Nelson Saksono, Adiwar Adiwar, Nono Darsono

Makara Journal of Technology

Dipole Magnetization Effect to Kerosene Characteristics. Investigation of kerosene characteristics has been done by ex-situ dipole magnetization. The results show that magnetization technique can be able to influence kerosene characteristics. Polarity and viscosity of the kerosene are observed by measuring refractive index and viscosity. An hour of 4330 Gauss flux magnetic will increase refractive index from 1.447 to 1.449 and decrease the viscosity from 1.278 to 1.256. Those changing support de-clustering occurrence and polarity increment of kerosene molecule. Gas chromatography and infrared result show that those changing do not alter kerosene structure and composition.

Study Of 2d And 3d Optical Beam Induced Voltage Imaging Using Photoresistor Sensor, Warsito Warsito, Sri Wahyu Suciyati, Susi Harnani, Akhmad Dzakwan

Makara Journal of Technology

Study of 2D and 3D Optical Beam Induced Voltage Imaging Using Photoresistor Sensor. This article shows a method to study OBIV (optical beam induced voltage) imagerie system, that usually employ a laser scanning microscopy system. The OBIV imagerie system developed use a photoresistor sensor as a sample and simultaneously it can be used for analyzing its inhomogeneity response. Resolution of the system is still low, about 350μm due to high value of incident light diameter. The results inform that photoresistor sensors gave an optimum response if the incident light hits the center of sensible zone.

Flexi Radio Base Station (Rbs) Performance Analysis Of Voice And Trafic On Kota 2 Jakarta Barat Base Station Control (Bsc), Mushfar Ferdian, Fitri Yuli Zulkifli

Makara Journal of Technology

Flexi Radio Base Station (RBS) Performance Analysis of Voice and Trafic on Kota 2 Jakarta Barat Base Station Control (BSC). The CDMA 2000 technology uses circuit switch method to handle voice traffic and packet switch method to handle data traffic between the user and RBS (Radio Base Station). These two parameters can be used to measure performance of the network generally, so it is necessary to optimize them. This paper analyze the performance of RBS by measuring its parameters such as set up failure ratio, drop ratio, and occupancy. Furthermore, the traffic increment is calculated too in order to provide …

Water Quality Of Rivers And Ponds On Dki Jakarta, Diana Hendrawan

Makara Journal of Technology

Water Quality of Rivers and Ponds on DKI Jakarta. Thirteen big rivers, some small rivers, and 40 ponds spread over districts at Jakarta city are potential to support human being life. As the population is growing and the usage of stream water is increasing, the condition and quality of rivers and ponds are changing. Crowd housing can affect rivers and ponds pollution, as the people awareness about clean and healthy environment is less. Stream water pollution assessment can be done by counting the effect of pollutant to life of stream water organisms. This assessment unit could be classified into physics, …

Time Domain Characterization Of 1-2 Ghz Circular-Ended Bowtie Antenna Using Normalizad Impulse Response, Joko Suryana, Andriyan B. Suksmono, Tati R. Mengko

Makara Journal of Technology

Time Domain Characterization of 1-2 GHz Circular-ended Bowtie Antenna Using Normalizad Impulse Response. Frequency domain analysis is a powerful and compact tool for characterizing the antenna parameters such as gain, radiation pattern and the impedance as a function of frequency. However, if time or space is a major concern, such as in the GPR appication, the time domain analysis would be a very important tool due to their unique capability for determining the echo delay and range profile of target image. In this paper, we will describe the classical theory of system characterization in time domain, and then also propose …

High Temperature Heat Exchanger Project:Quarterly Progress Report January 1, 2005 Through March 31, 2005, Anthony Hechanova

Publications (NSTD)

Quarterly Collaboration Meeting. Ceramatec, Inc. hosted a UNLVRF HTHX Project quarterly meeting on March 17 in Salt Lake City, Utah. The purpose of the meeting was to promote collaboration and communication among the UNLV Research Foundation partners. Collaborators had the opportunity to discuss their research program plan and update their progress. The next meeting will be in June in San Diego City hosted by General Atomics.

Theoretical Modeling Of Protective Oxide Layer Growth In Non-Isothermal Lead-Alloys Coolant Systems: Quarterly Progress Report (01/01/05- 03/31/05), 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 …

Creep Behavior Of An Oxide/Oxide Composite With Monazite Coating At Elevated Temperatures, Sean S. Musil

Theses and Dissertations

This study focuses on experimental investigation of stress-rupture behavior (creep response) of an oxide/oxide composite in a cross-ply (0/90) lay-up at elevated temperature. The test material, Nextel 610/monazite/alumina composite, employs monazite, an oxidation-resistant interfacial coating designed to improve performance at elevated temperatures. The experimental program included monotonic tensile tests to failure and creep-rupture tests at elevated temperatures. Tensile tests served to establish an ultimate tensile strength (UTS) for the material. The ensuing creep-rupture tests involved stress levels at varying percentages of the UTS. Stress-rupture curves at 900 and 1100 degrees C were established. A family of creep curves for various …

An Investigation Of A Simplified Gouging Model, Gregory S. Rickerd

Theses and Dissertations

Gouging is a type of structural failure that becomes important when two metals slide against each other at velocities in the range of 1.5 kilometers per second. A computer model has previously been used to model the development of gouging at the Holloman High Speed Test Track. This model has not been experimentally verified to be correct, due to the complexity of the model. This research develops a simplified model that can be experimentally verified. The computer program utilized in this research was studied to determine the most appropriate options to use in simulations. This was accomplished by modeling a …

Experimentation And Analysis Of Composite Scarf Joint, Benjamin M. Cook

Theses and Dissertations

Composite bonded scarf repairs were examined by experimentally measuring and analytically predicting the residual curing strains and strains due to mechanical loading. To accomplish this a three prong approach was used: a full strain field through a repaired laminate's thickness was measured for both a loaded specimen and a specimen with the residual strain released, models were developed for comparison to both states, and data was collected for large tensile test specimens at various stages of being scarf repaired. A ~14:1 straight scarfed one-inch wide specimen was used to collect Moire interferometry data to calculate a full strain field due …

Thermal Characteristics Of Pitch Based Carbon Foam And Phase Change Materials, Kevin W. Wierschke

Theses and Dissertations

Phase-change thermal energy storage devices offer thermal control systems an option that allows a smaller heat sink to be used by absorbing the thermal energy quickly and storing it in the phase change to prevent failure of electronic components and then slowly releasing the heat to the heat sink. This paper experimentally determined the transient response of carbon foam with a phase-change material by measuring the response to a step temperature input to test samples. The transient response was recorded until steady state was reached. An analytic response was created and compared against the measured response. A simplified analytic prediction …

Effect Of Temperature And Steam Environment On Fatigue Behavior Of An Oxide-Oxide Continuous Fiber Ceramic Composite, Chalene A. Eber

Theses and Dissertations

There is an ever-increasing need for materials that maintain high strength and fracture toughness at elevated temperatures and in complex environments. Advanced aerospace applications are motivating the development of composite materials that can meet demanding requirements. This research effort investigates mechanical behavior of an oxide-oxide continuous fiber ceramic composite (CFCC) consisting of a porous alumina matrix reinforced with mullite/alumina Nextel 720 fibers developed specifically for advanced aerospace applications. Tension-tension fatigue behavior of this CFCC was studied at 1200 and 1330 °C in laboratory air and 100% steam environments. Fatigue resistance and retained strength properties were determined. Effects of environmental degradation …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Quarterly Report, January 2005 To March 2005, Earl Wolfram, Thomas Hartmann, Kenneth Czerwinski

Fuels Campaign (TRP)

This project will examine inert matrix fuels containing ZrO₂ and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO₂. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10% of ²³⁹Pu. Ceramics will be synthesized and characterized based on the reactor physics results. The solubility the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, will be investigated in a manner to provide …

Application Of Functionally Graded Materials In Aircraft Structures, William G. Cooley

Theses and Dissertations

A Functionally Graded Material (FGM) is a material which has a continuous variation of material properties through-the-thickness. This thesis will explore analysis of FGM flat plates and shell panels, and use FGM's unique characteristics to retrofit a cracked exhaust wash structure. FGMs are first characterized as flat plates under pressure and thermal loading. Next, FGM shell panels are characterized under thermal loading. Conclusions drawn from FGM characterization are used to develop a patch to retrofit a cracked aircraft exhaust wash structure. The exhaust wash structure is first analyzed to provide a baseline and then several FGM patches are evaluated on …

Effects Of Temperature And Shot-Peening Intensity On Fretting Fatigue Behavior Of Titanium Alloy Ti-6al-4a, Salman Albinali

Theses and Dissertations

Effects of temperature and shot-peening intensity on fretting fatigue behavior of Ti-6Al-4A were investigated in this study. S-N curves were obtained for both room and elevated temperatures (260 C) for two different shot-peened intensities (4A and 10A). Stress relaxation behavior under both fretting fatigue at elevated temperature and temperature exposure only were also investigated after their measurements were calculated using X-ray diffraction method. The crack initiation location and the crack angle orientation along the surface were determined using optical and scanning electron microscopy (SEM). Cracks initiated near the trailing edge of the tested specimens. Cracks initiated on the contact surface …

Biaxial Fatigue Behavior Of Niti Shape Memory Alloy, Daniel M. Jensen

Theses and Dissertations

Nitinol is a shape memory alloy (SMA) capable of martensite-to-austenite phase transformations enabling shape-memory behavior. Shape-memory properties make Nitinol a strong candidate material for use in aircraft applications such as actuators. Structural integrity and reliability of torque tube actuators must be assured before this material can be used in flight-critical components. Thorough understanding of the fatigue response of the material is essential for a structurally-sound SMA actuator design. The present effort investigates pure torsion and combined tension-torsion fatigue behavior of Nitinol at room temperature. Monotonic tests in tension and torsion were conducted to typify uni-directional stress-strain behavior. Fully-reversed torsion fatigue …