Engineering Commons^™

Electrochemical Na-Storage Materials And Their Applications For Na-Ion Batteries, Jiang-Feng Qian, Xue-Ping Gao, Han-Xi Yang

Journal of Electrochemistry

Oncoming large scale electric energy storage (EES) requires battery systems not only to have sufficient storage capacity but also to be cost-effective and environmentally friendly. Li-ion batteries for widespread EES applications may be limited due to the constraint of global lithium resource. From the considerations of available resources and environmental impact, Na-ion batteries have potential advantages as next generation secondary batteries and an alternative to Li-ion batteries. However, in the present state of the art, the Na-storage cathodes reported so far are still deficient both in energy density and power capability, while the carbon and alloy anodes for Na-ion batteries …

Surface Composition Structure And Electrochemical Performance Of Aluminum Doped Lifepo4, Huai-Fang Shang, Wei-Feng Huang, Wang-Sheng Hu, Ding-Guo Xia, Zi-Yu Wu

Journal of Electrochemistry

Despite there are many successful reports about the preparation of electrode materials with surface coating for lithium ion batteries, the study in surface self-coating of cathode materials using segregation of doping elements and their electrochemical properties is still very rare. The LiFePO₄ particles with rich-Al on the surface were synthesized by one step solvothermal route. TEM results demonstrated that the surface of the obtained LiFePO₄ particles was well-covered by the amorphous coating. The soft X-ray absorption spectroscopy (XAS) and Auger electron spectroscopy (AES) component analyses revealed that the amorphous coating was composed of LiFe_1-xAl_xPO …

Free-Troposphere Ozone And Carbon Monoxide Over The North Atlantic For 2001-2011, Aditya Kumar, S. Wu, M. F. Weise, R. Honrath, R. C. Owen, D. Helmig, L. Kramer, M. Val Martin, Q. Li

Michigan Tech Publications, Part 1

In situ measurements of carbon monoxide (CO) and ozone (O3) at the Pico Mountain Observatory (PMO) located in the Azores, Portugal, are analyzed together with results from an atmospheric chemical transport model (GEOS-Chem) and satellite remote sensing data (AIRS (Atmospheric Infrared Sounder) for CO, and TES (Tropospheric Emission Spectrometer) for O3) to examine the evolution of free-troposphere CO and O3 over the North Atlantic for 2001-2011. GEOS-Chem captured the seasonal cycles for CO and O3 well but significantly underestimated the mixing ratios of CO, particularly in spring. Statistically significant (using a significance level of 0.05) decreasing trends were found for …

Enhanced Dna Sensing Via Catalytic Aggregation Of Gold Nanoparticles, Herbert M. Huttanus, Elton Graugnard, Bernard Yurke, William B. Knowlton, Wan Kuang, William L. Hughes, Jeunghoon Lee

Materials Science and Engineering Faculty Publications and Presentations

A catalytic colorimetric detection scheme that incorporates a DNA-based hybridization chain reaction into gold nanoparticles was designed and tested. While direct aggregation forms an inter-particle linkagefrom only one target DNA strand, catalytic aggregation forms multiple linkages from a single target DNA strand. Gold nanoparticles were functionalized with thiol-modified DNA strands capable of undergoing hybridization chain reactions. The changes in their absorption spectra were measured at different times and target concentrations and compared against direct aggregation. Catalytic aggregation showed a multifold increase in sensitivity at low target concentrations when compared to direct aggregation. Gelelectrophoresis was performed to compare DNA hybridization reactions …

Nd–Fe–B Nanoparticles Through Surfactant Assisted Mechanical Milling And Alloy Design, Jordann M. Bornhoft

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Surfactant-assisted mechanical milling has been used to produce discrete nanoparticles of both Nd-Fe-B and Sm-Co amenable for bottom-up production of nanostructured or nanocomposite permanent magnets. However, in Nd-Fe-B the comminution of the material proceeds by transgranular fracture, which influences both the morphology of the nanoparticles and the magnetic properties. This paper utilizes alloy design to alter the fracture behavior from transgranular fracture to intergranular fracture. Nd-rich Nd₂Fe₁₄B alloys were produced by melt spinning in an overquenched state. The melt spun ribbons were annealed at 700°C and 800°C to ensure complete crystallization and to form different grain …

Microgrid Development Using A Grid Tie Inverter, Hartono Budi Santoso, Budiyanto Budiyanto

Makara Journal of Technology

The use of renewable energy sources (RES), especially photovoltaic (PV), to meet the demand of electrical energy has been getting a great deal of attention as an alternative solution to electrical energy deficit problems. RES are being applied in power systems in a variety of configurations including microgrid systems. One of the characteristics of a microgrid is capability to supplying power to grid when there is an excess power to supply local load. This research examines the chances of saving power consumption from grid using power converters grid tie inverter (GTI) in a microgrid configuration. The test is done by …

Surface Treatment Of Fly Ash For Improving The Tensile Strength Of Fly Ash/Unsaturated Polyester Composites, Sugiman Sugiman, Paryanto Dwi Setyawan

Makara Journal of Technology

The paper presents the surface treatment of fly ashes using acid and alkali solution on the tensile strength of the fly ash/unsaturated polyester (UP) composites. Sulfuric acid (H2SO4), hydrofluoric acid (HF) and sodium hydroxide (NaOH) solution with concentration of 0%, 5%, 10%, 15%, and 20% (by weight) were used for surface treatment of fly ashes. Generally, the tensile strength of the treated fly-ash/UP composites shows a significant increase compared to the untreated fly ash. Of all surface treatments studied, the optimum tensile strength was obtained at a concentration of 10%. At this concentration, at a fly ash content of 30% …

Recycling Roof Tile Waste Material For Wall Cover Tiles, Ambar Mulyono, Silfia Mona Aryani, Joko Lulut

Makara Journal of Technology

Prior research on roof tile waste treatment has attempted to find the appropriate technology to reuse old roof tile waste by create wall cladding materials from it. Through exploration and experimentation, a treatment method has been discovered to transform the tile fragments into artificial stone that resembles the shape of coral. This baked clay artificial stone material is then processed as a decorative element for vertical surfaces that are not load-bearing, such as on the interior and exterior walls of a building. Before applying the fragments as wall tiles, several steps must be taken: 1) Blunting, which changes the look …

Synthesis Of Tungsten Oxide Nanowires Onto Ito Glass Using T-Cvd, Tomy Abuzairi, Bohr-Ran Huang, Tzu-Ching Lin

Makara Journal of Technology

Tungsten oxide is an n-type semiconductor with interesting physical and chemical properties that make it suitable for various technological applications. Tungsten oxide nanowires were synthesized not only at low temperature but also without the use of any catalysts. The tungsten oxide nanowires were synthesized at 550 °C with tungsten layers onto the ITO glass using thermal chemical vapor deposition (T-CVD). The SEM image shows that the tungsten oxide nanowires are effectively grown with the 200 nm tungsten film. The Raman spectra shoulder at ~690 cm-1 proves the synthesized of tungsten oxide nanowires.

Semiconductor Thermal Neutron Detector, Toru Aoki, Aki Miyake, Takayuki Nakano, Akifumi Koike, Hisashi Morii, Hidenori Mimura

Makara Journal of Technology

The CdTe and GaN detector with a Gd converter have been developed and investigated as a neutron detector for neutron imaging. The fabricated Gd/CdTe detector with the 25 mm thick Gd was designed on the basis of simulation results of thermal neutron detection efficiency and spatial resolution. The Gd/CdTe detector shows the detection of neutron capture gamma ray emission in the 155Gd(n, g)156Gd, 157Gd(n, g)158Gd and 113Cd(n, g)114Cd reactions and characteristic X-ray emissions due to conversion-electrons generated inside the Gd film. The observed efficient thermal neutron detection with the Gd/CdTe detector shows its promise in neutron radiography application. Moreover, a …

Radiation Characteristics Of A Planar Strip Dipole Antenna And A Slot Dipole Antenna For Thz Applications, Catur Apriono, Eko Tjipto Rahardjo

Makara Journal of Technology

The development of a THz system often requires a device that is used to radiate or detect THz waves. One way to fulfill this requirement is to use an antenna. Therefore, we need to consider the radiation characteristics of an antenna working in the THz region. In this paper, we present simulation study of two dipole antennas, i.e. a planar strip dipole antenna and a slot dipole antenna. The simulation results show that a planar strip dipole antenna has a better radiation efficiency (more than 95%) compared to the slot dipole. It also shows that an efficiency of more than …

The Effect Of Pressing Temperature And Time On The Quality Of Particle Board Made From Jatropha Fruit Hulls Treated In Acidic Condition, Apri Heri Iswanto, Fauzi Febrianto, Yusuf Sudo Hadi, Surdiding Ruhendi, Dede Hermawan

Makara Journal of Technology

The high of pH of jatropha fruit hulls causes the negative properties of particleboard made from this material. Adjusting the particle acidity and pressing conditions (temperature and time) is among the technical modifications available to improve this particleboard’s properties. Particle acidity has been adjusted in a previous research project, and immersing the particles in acetic acid was found to be the best treatment in this preliminary research. In order to improve the particleboard’s properties, an experiment was conducted to determine the best pressing temperature and time. The objective of the research was to evaluate the influence of pressing temperature and …

Corrosion Behavior Of Tialn Film On Aisi 4140 Steel, T Wongpinij, P Wongpanya, C Euaruksakul, P Photongkam, N Witit-Anun

Journal of Metals, Materials and Minerals

The corrosion behavior of uncoated and TiAlN coated on AISI 4140 steel were studied by an electrochemical technique in 3.5 wt% NaCl solution at pH value of 2, 7 and 10 at room temperature. The corrosion potential (Ecorr), pitting potential (Epit), corrosion rate (Rmmy) and passive region in polarization curves were analyzed and compared.After electrochemical testing, samples surface was characterized by scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and X-ray photoemission electron microscopy (X-PEEM). The results indicated that the TiAlN coated samples yielded better corrosion resistance than the uncoated samples. The coated samples had lower corrosion rate …

Dolomite Stabilized Zirconia For Refractory Application : Part-I Phase Analysis, Densification Behavior And Microstructure Of Partial Stabilized Zirconia, R Prasad Rana, P Kumar, A Suvrajit Bal

Journal of Metals, Materials and Minerals

In the continuous casting of steel, Zircon and Zirconia based products are used due to its high thermal stability, excellent erosion resistance, self-opening, consistent casting speed and resistance to oxygen lancing during casting for removal of inclusion clogging and to streamline the flow. Higher casting sequences of molten steel CaO or MgO stabilized zirconia nozzles were being used and for industrial application point of view, dolomite stabilized zirconia (DSZ) could be a better substitute for the stabilization of zirconia. DSZ samples were prepared having 3,4,5,6 and 7 mole % of dolomite by solid state route using high purity monoclinic zirconia …

Mineralogical Characterization Of Pozuzo District's Soils Through Physical Techniques, M L Cerón Loayza, J B. Cabrejos, F Reyes Navarro

Journal of Metals, Materials and Minerals

We introduce a study on soils in three different fields of plantations in Pozuzo District, Oxapampa province, Peru. Two of the fields are cultivated and the third one has a degradation problem. In situ, in all, we collected 29 samples in the three plantations. We utilized analytical and physical techniques, namely, energy dispersive X-ray fluorescence, X-ray diffractometry, and transmission Msbauer spectroscopy; we complemented our research with a physical-chemical analysis to determine texture, pH, content of organic matter and cation interchange capacity. For all analyzed samples, the results of the analysis by energy dispersive X-ray fluorescence show the presence of the …

Friction And Wear Of Polytetrafluoroethylene/Graphene Oxide Composite Thin Films, Justin Kyle Carter

Graduate Theses and Dissertations

Polytetrafluoroethylene (PTFE) is a commonly used solid lubricant due to its low coefficient of friction and chemical inertness. As a polymer, PTFE suffers from high wear and low adhesion to substrates limiting its use as a thin film. Thin PTFE films are ideal candidates for solid lubrication in micro-machines and bearing applications. The main goal of this work is to enhance the durability of thin PTFE films through the addition of few layered graphene oxide (GO) as filler. In order to address adhesion issues, the addition of an adhesive layer of polydopamine (PDA) between stainless steel substrates and thin PTFE …

Crack Growth Behavior Under Creep-Fatigue Conditions Using Compact And Double Edge Notch Tension-Compression Specimens, Santosh B. Narasimha Chary

Graduate Theses and Dissertations

The American Society for Testing and Materials (ASTM) has recently developed a new standard for creep-fatigue crack growth testing, E 2760-10, that supports testing compact specimens, C(T), under load controlled conditions. C(T) specimens are commonly used for fatigue and creep-fatigue crack growth testing under constant-load-amplitude conditions. The use of these specimens is limited to positive load ratios. They are also limited in the amount of crack growth data that can be developed at high stress intensity values due to accumulation of plastic and/or creep strains leading to ratcheting in the specimen. Testing under displacement control can potentially address these shortcomings …

Kolsky Bar Experiment For High-Rate Large Deformations Of Polycarbonate, Jason G. Vogeler

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Polycarbonate (PC) is a tough, transparent engineering thermoplastic. Its impact strength and ability undergo large plastic deformations without shatter make PC an ideal protective material for impact-resilient eyewear, aircraft windows and transparent armor. A good understanding of the response of this material to large deformations at high strain rates is critical for its utilization in these applications. To this end, a striker-less Kolsky bar device is employed in this work for the needed material characterization. The apparatus allow impulsive torsion and/or compression loadings with pulse durations sufficiently long for the plastic flow behavior to develop fully. Three new testing techniques …

Kolsky Bar Experiment For High-Rate Large Deformations Of Polycarbonate, Jason Gerald Vogeler

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Polycarbonate (PC) is a tough, transparent engineering thermoplastic. Its impact strength and ability undergo large plastic deformations without shatter make PC an ideal protective material for impact-resilient eyewear, aircraft windows and transparent armor. A good understanding of the response of this material to large deformations at high strain rates is critical for its utilization in these applications. To this end, a striker-less Kolsky bar device is employed in this work for the needed material characterization. The apparatus allow impulsive torsion and/or compression loadings with pulse durations sufficiently long for the plastic flow behavior to develop fully. Three new testing techniques …

Au-Based Core-Shell Nanoparticles For Direct Formic Acid Fuel Cells, Chiajen Hsu

Material Science and Engineering Dissertations - Archive

Unique Au/Pd core-shell nanoparticles were synthesized via galvanic replacement of Cu by Pd on hollow Au nanoparticles. Au/PtCu core-shell nanoparticles were also synthesized using this method. These core-shell nanoparticles exhibited unique electrochemical properties - the Au/Pd nanoparticles demonstrated superior electrochemical activity for formic acid oxidation and the Au/PtCu nanoparticles improved the kinetics in oxygen reduction reaction, when compared to their corresponding pure metal particles. In this dissertation, we aim at investigating catalytic abilities of these core-shell nanoparticles and understanding electrochemical reactions in direct formic acid fuel cells.Different Pd thicknesses on hollow Au nanoparticles in the core-shell configuration have been investigated. …

Grain Structure Evolution Of Tin-Based Lead-Free Solder Joints In Electronic Packaging Assembly And Its Impact On The Fatigue Reliability, Huili Xu

Material Science and Engineering Dissertations - Archive

Solder is one of the main joints materials used in the electronics for decades of years. It is not only the mechanical support but also conducts the electric signals in the electronics. However, the regulation of lead content in electronic devices has driven the transition from lead-tin solder to the lead-free solder that requires lots of research to fill the knowledge gap in the lead-free solder property. At the same time, the reliability issues due to solder failure are of great interest as the miniaturization and mobilization trend of the electronic devices continues. A lot of works have been done …

Bubble Template Synthesis Of Hollow Gold Nanoparticle, Chivarat Muangphat

Material Science and Engineering Dissertations - Archive

Recently, a new synthesis method for creating hollow gold nanoparticles by using electrochemically hydrogen nanobubbles as a template was discovered in our research group. Hollow gold nanoparticles with well-controlled, tunable dimension and morphology can be synthesized using various synthesis conditions. Such hollow gold nanoparticles exhibit unique optical properties that can be tuned by changing the nanoparticle structures. The objective of this study is to understand the formation mechanism of hollow gold nanoparticles synthesized using bubble template synthesis method. The synthesis process can be divided into two main processes: the formation of hydrogen nanobubble and the reduction of gold ions on …

The Effects Of Microstructure On The Mechanical Properties Of Hard Transition Metal Silicon Nitride Nanocomposite Coatings, Jessica Mooney

Material Science and Engineering Dissertations - Archive

In this body of work, the examination of two different transition metal silicon nitride (MeSiN) systems using two different methods of physical vapor deposition (PVD) allowed for the development of a detailed understanding between the processing conditions, the micro-scale and nano-scale morphology, and the mechanical properties of the as-deposited thin film nanocomposite coatings. TiSiN coatings processed using the high-energy Arc deposition technique had hardness values of up to 33.6 GPa, and a previously unidentified (TiSi)N FCC crystalline phase, likely present due to the amounts of energy employed during coating processing, was discovered via intensive low angle X-Ray diffraction (XRD) and …

Scrap Dissolution In Molten Iron Containing Carbon For The Case Of Coupled Heat And Mass Transfer Control, Ajay Kumar Shukla, Brahma Deo, D. G.C. Robertson

Materials Science and Engineering Faculty Research & Creative Works

The scrap dissolution in an actual process like the BOF is affected both by mass transfer and heat transfer. In this paper, the mass transfer of carbon in liquid melt is considered along with heat transfer. The approaches used in this paper to model the scrap dissolution phenomenon include the application of Green's function, quasi-static, integral profile, and the finite difference approach for different Biot numbers. Mass transfer coefficients are calculated using the Chilton-Colburn's analogy for the case of forced convection. Since the quasi-static approach requires the least computational time, it is used for a detailed parametric study, including the …

Role Of Air Gap In Scrap Dissolution Process, Ajay Kumar Shukla, Brahma Deo, D. G.C. Robertson

Materials Science and Engineering Faculty Research & Creative Works

The role of the air gap formed between scrap and a solidified metal shell at the beginning of the scrap dissolution process has been investigated. The effect of air gap has been investigated for different Biot numbers (10 to 100) and ratios of air gap to liquid melt heat transfer coefficient (0.1 to 0.9). The predictions of the mathematical model are compared with the experimental results reported elsewhere. The role of air gap is found to be significant only for low Biot numbers (< 50) and for low ratios of air gap to liquid melt heat transfer coefficient (< 0.25). © 2013 The Minerals, Metals & Materials Society and ASM International.

Investigation Of The Effects Of Rapid Thermal Annealing On Mbe Grown Gaasbi/Gaas Heterostructures For Optoelectronic Devices, Perry C. Grant

Graduate Theses and Dissertations

High efficiency optoelectronic devices rely on high quality materials making up the device structure. The scope of this thesis investigates the effectiveness of rapid thermal annealing (RTA) at improving the material quality of GaAsBi/GaAs heterostructures. During the fabrication of a device, the contacts of the device had the rapid thermal annealing process accomplished to produce ohmic contacts and this research explored if this annealing treatment degraded the quantum wells that made up the active region of a device. To investigate these effects, a system to measure the photoluminescence of the material system was constructed utilizing Fourier Transform Infrared Spectroscopy. The …

Monodentate, Bidentate And Photocrosslinkable Thiol Ligands For Improving Aqueous Biocompatible Quantum Dots, Hiroko Takeuchi

Graduate Theses and Dissertations

Water-soluble Quantum Dots (QDs) are highly sensitive fluorescent probes that are often used to study biological species. One of the most common ways to render QDs water-soluble for such applications is to apply hydrophilic thiolated ligands to the QD surface. However, these ligands are labile and can be easily exchanged on the QD surface, which can severely limit their application. As one way to overcome this limitation while maintaining a small colloidal size of QDs, we developed a method to stabilize hydrophilic thiolated ligands on the surface of QDs through the formation of a crosslinked shell using a photocrosslinking approach. …

Feasibility Of The Use Of Ultrasound Measurements For Grade Verification Of The Performance Grade Asphalt Binders, Mehdi Khalili

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research investigates the feasibility of application of high frequency immersion ultrasonic measurement (UM) to discriminate different performance grade (PG) asphalt binders. PG asphalt binder is one of the main components of hot mix asphalt used for roadway construction. UT may provide an inexpensive alternative to sophisticated tests currently used for quality control of PG asphalt binders. Nine different PG asphalt binders used were selected for this investigation. Velocity (V) and integrated response (IR) of the ultrasonic wave were measured. The IR is a measure of the ratio of ultrasonic energy transmitted into the material to the ultrasonic energy reflected …

Heat Treatment Of Steel Parts In Different Media, Sc Maidargi, V Rani

Journal of Metals, Materials and Minerals

This study reports an investigation of the effect of different media (oil and polymer) on the properties of different grade steel parts. Steel parts after manufacture, will not have the desired properties like wear resistance, tensile strength, surface and core hardness. To attain these, heat treatment processes like Case Hardening (CH) or Through Hardening (TH) were carried out in sealed quench furnace and rotary furnace. The microstructure of the steel part influences the hardness of the same. The required microstructure is Fine Tempered Martensite (FTM) and the Quench media has a very important role in achieving this. Using different grades …

Use Of Polymer Rapid Tools As Functional Injection Mold Tooling, Sean Derrick

Masters Theses

Conventional tool making for injection molded plastics is expensive, time consuming, and generates a great deal of waste. Presently, industry is waiting for what is commonly referred to as Rapid Tooling (RT). The greatest opportunity for RT implementation would be the use of Additively Manufacturing (AM) technology. Specifically, AM techniques which use a high strength polymer resin substrate.

The following research is an initial feasibility study to determine if Polymer Rapid Tools (PRTs) could be used as functional injection mold tooling. The objective of the research was to determine if a PRT could mold a variety of features to a …