Engineering Commons^™

Measurements Of Methyl Radicals And Temperatures By Using Coherent Microwave Rayleigh Scattering From Resonance Enhanced Multiphoton Ionization, Yue Wu

Doctoral Dissertations

This thesis includes two main parts: (I) The CH₃[methyl radical] detection in methane/air flames and (II) the rotational temperature measurement of O₂[molecular oxygen] in a variety of environments by using coherent microwave Rayleigh scattering from resonance enhanced multiphoton ionization (Radar REMPI).

In first the part, from Chapter I to Chapter III, the methyl radical detection and quantitative measurements have been conducted in hydrocarbon flame with one-dimensional and two-dimensional spatial-resolved concentration distribution. Due to the proximity of the argon resonance state (4+1 REMPI by 332.5 nm) with the CH₃ state (2+1 REMPI by 333.6 nm), in …

Temperature Measurement Using Infrared Spectral Band Emissions From H2o, Daniel Jared Ellis

Theses and Dissertations

Currently there is no known method for accurately measuring the temperature of the gas phase of combustion products within a solid fuel flame. The industry standard is a suction pyrometer and thermocouple which is intrusive, both spatially and temporally averaging, and difficult to use. In this work a new method utilizing the spectral emission from water vapor is investigated through modeling and experimental measurements. This method was demonstrated along a 0.75m line of sight, averaged over 1 minute in the products of a natural gas flame but has the potential to produce a spatial resolution on the order of 5 …

Assessment Of Asphalt Concrete Pavement Quality By Using Infrared Thermal Imaging Technology, Lisa Y. Chen, Mei-Yun Wang, Chien-Chiao Chao, Wei Lo

Journal of Marine Science and Technology

Manholes cause uneven pavements, which affect the quality of pavement services, leading to public criticism in Taiwan. Many manholes are buried beneath pavements to ensure evenness and enhance the usability of pavements for pedestrians. The presence of manholes affects the quality of the asphalt concrete underneath the pavement because then conducting excavations using road construction equipment becomes difficult, ultimately leading to early deterioration of the pavement surfaces. Temperatures can also differ considerably between the manhole and non-manhole locations on asphalt concrete pavement. This study used infrared thermal imaging technology and an analysis of variances statistical method to investigate the differences …

Fatigue Life Estimation Of Modified Railroad Bearing Adapters For Onboard Monitoring Applications, Alexis Trevino, Arturo A. Fuentes, Constantine Tarawneh, Joseph Montalvo

Mechanical Engineering Faculty Publications and Presentations

This paper presents a study of the fatigue life (i.e. number of stress cycles before failure) of Class K cast iron conventional and modified railroad bearing adapters for onboard monitoring applications under different operational conditions based on experimentally validated Finite Element Analysis (FEA) stress results. Currently, freight railcars rely heavily on wayside hot-box detectors (HBDs) at strategic intervals to record bearing cup temperatures as the train passes at specified velocities. Hence, most temperature measurements are limited to certain physical railroad locations. This limitation gave way for an optimized sensor that could potentially deliver significant insight on continuous bearing temperature conditions. …

Evaluation Of Distribution Environment In Ltl Shipment Between Central Europe And South Africa, Peter Borocz, Paul Singh, Jay Singh

Journal of Applied Packaging Research

Due to the global expansion of transportation and handling companies, the distribution and supply chains of both raw materials and finished products now requires a better understanding of the shipping environment. This international shipping and handling information describing the physical and climatic conditions provides packaging engineers the required technical information to design better packaging to provide protection to products in various segments of the supply chain. In these global supply chains, products emerging from Central Europe also play an increasingly important role today. From this region, the truck and vessel combination is the most dominant transportation mode for non-time sensitive …

Mechanical Properties Of Intermetallic Compounds In Electrodeposited Multilayered Thin Film At Small Scale By Nanoindentation

Faculty of Engineering University of Malaya

Mechanical properties of intermetallic compounds (IMCs) which were formed in electrodeposited Cu/Sn and Cu/Ni/Sn multilayered thin film have been investigated. The layers of Cu, Sn and Ni were formed by electrodeposition technique using copper pyrophosphate, tin methanesulfonic and nickel Watts baths, respectively. After synthesis, samples were subjected to high temperature aging at 150 degrees C for 168 h. Two different types of intermetallics Cu3Sn and Cu6Sn5 were formed in Cu/Sn. After adding ultra-thin layer of Ni (70 nm) in between Cu and Sn layers, (Cu, Ni)(6)Sn-5 was formed after aging at similar condition to that of Cu/Sn. Tin whisker growth …

Waste Heat Generation: A Comprehensive Review, Nazli Yeşiller, James L. Hanson, Emma H. Yee

Civil and Environmental Engineering

A comprehensive review of heat generation in various types of wastes and of the thermal regime of waste containment facilities is provided in this paper. Municipal solid waste (MSW), MSW incineration ash, and mining wastes were included in the analysis. Spatial and temporal variations of waste temperatures, thermal gradients, thermal properties of wastes, average temperature differentials, and heat generation values are provided. Heat generation was influenced by climatic conditions, mean annual earth temperatures, waste temperatures at the time of placement, cover conditions, and inherent heat generation potential of the specific wastes. Time to onset of heat generation varied between months …

Evaluating The Optical Properties Of Tio2 Nanofluid For A Direct Absorption Solar Collector

Faculty of Engineering University of Malaya

Recent studies specify that designated nanofluids may increase the proficiency of direct absorption solar thermal collectors. To determine the efficiency of nanofluids in solar applications, their capability to change light energy to thermal energy must be identified (i.e., the absorption spectrum of the solar material). In view of that, this study compares model predictions to spectroscopic measurements of extinction coefficients over wavelengths that are important for solar energy (200- 1100nm). In the first decade of nanofluid research, most of the focus was on measuring and modeling the fundamental thermophysical properties of nanofluids (i.e., thermal conductivity, density, viscosity, and convection coefficients). …

Monitoring And Controlling Of Air Pollution Using Intelligent Control System, Innovative Research Publications Irp India, Anil.H. Sonune, S.M. Hambarde

Innovative Research Publications IRP India

This paper focuses on implementation of Environmental air pollution monitoring and controlling system. First, the air pollution monitoring system contains sensors to monitor the interested pollution parameter in environment. Second, wireless communication modules for monitoring system were developed using wireless sensor networks technologies based on ZigBee network. And then a performance of modules was estimated in the real-fields. Finally, integrated wireless sensor board which employs dust, CO2, temperature, humidity sensor and a ZigBee module was developed. The board is embedded device based on Arm processor LPC2148. This paper accelerates the digital convergence age through continual research and development of technologies …

The Tribological And Electrochemical Behavior Of Hvof-Sprayed Cr3c2-Nicr Ceramic Coating On Carbon Steel

Faculty of Engineering University of Malaya

High Velocity Oxygen Fuel (HVOF) is an excellent approach to prepare a good, wear-resistant lamella of Chromium Carbide-Nickel Chrome (Cr3C2-NiCr) on carbon steel for high temperature application. This research investigates the effect of a thin, deposited layer of Cr3C2-NiCr on carbon steel in terms of wear and corrosion properties. The microstructure of the HVOF-sprayed Cr3C2-NiCr coating was characterized at each step by scanning electron microscopy. Wear testing was performed with a pin-on-disk tester. Wear weight loss was examined by applying different loads over a 9048.96 m sliding distance. Experimental results show that the wear resistance of the coated sample reduced …

Changes In Heavy Rainstorm Characteristics With Time And Temperature, Barry A. Palynchuk Phd, Yiping Guo Phd

Barry A. Palynchuk PhD

The effects of climate change upon extreme rainfall is evaluated, based upon the identification of individual storms, and the changes in their statistical parameters and distributions. Those changes will be measured based upon historical time spans, and climatic temperature associated with the events. A brief review and comparison with other research is provided.

Changes In Heavy Rainstorm Characteristics With Time And Temperature - Presentation, Barry A. Palynchuk Phd

Barry A. Palynchuk PhD

The effects of climate change upon extreme rainfall is evaluated, based upon the identification of individual storms, and the changes in their statistical parameters and distributions. Those changes will be measured based upon historical time spans, and climatic temperature associated with the events. A brief review and comparison with other research provided.

Performance Enhancement Of A Flat Plate Solar Collector Using Titanium Dioxide Nanofluid And Polyethylene Glycol Dispersant

Faculty of Engineering University of Malaya

The use of TiO2 water nanofluid as a working fluid for enhancing the performance of a flat plate solar collector has been studied. The volume fraction of the nanoparticles was 0.1% and 0.3% respectively, while the mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min, respectively. Thermo-physical properties and reduced sedimentation for TiO2-nanofluid was obtained using PEG 400 dispersant. The results reveal the impact and importance of each of these parameters. Energy efficiency increased by 76.6% for 0.1% volume fraction and 0.5 kg/min flow rate, whereas the highest exergy efficiency achieved was 16.9% for 0.1% volume fraction …

Sintering Behaviour Of Natural Porous Hydroxyapatite Derived From Bovine Bone

Faculty of Engineering University of Malaya

The aim of this research is to study the properties of natural porous hydroxyapatite developed from bovine bone through a sintering process. Bovine bone samples were prepared and sintered in an air atmosphere at different temperatures ranging from 600 degrees C to 1000 degrees C. The sintered bodies were characterized to determine the phases present, bulk density, Ca/P ratio and Vickers hardness. In addition, the microstructural evolution of the sintered porous bodies was also examined. The results revealed that the thermal stability of the HA matrix was not disrupted and that all of the sintered bodies exhibited phase pure HA. …

Sintering Behaviour Of Natural Porous Hydroxyapatite Derived From Bovine Bone

Faculty of Engineering University of Malaya

The aim of this research is to study the properties of natural porous hydroxyapatite developed from bovine bone through a sintering process. Bovine bone samples were prepared and sintered in an air atmosphere at different temperatures ranging from 600 degrees C to 1000 degrees C. The sintered bodies were characterized to determine the phases present, bulk density, Ca/P ratio and Vickers hardness. In addition, the microstructural evolution of the sintered porous bodies was also examined. The results revealed that the thermal stability of the HA matrix was not disrupted and that all of the sintered bodies exhibited phase pure HA. …

Analysis Of Transient Natural Convection Flow Past An Accelerated Infinite Vertical Plate, Innovative Research Publications Irp India, Kaprawi S.

Innovative Research Publications IRP India

This work describes a vertical hot plate moves with acceleration and with variation wall temperature. The temperatures of the plate decrease with the increase of velocity of the plate. The temperature and velocity are given by the governing equations. The dimensionless equations of the problem have been solved numerically by the finite difference method. The temperature and the velocity profiles against several parameters like Prandtl Number, Grashoft number and time are presented. The results show that the temperature and velocity profiles are significantly influenced by Prandtl and Grashoft number.

Modeling The Polyphenoloxidase Inactivation Kinetics In Pear, Apple And Strawberry Purees After High Pressure Processing

Faculty of Engineering University of Malaya

High Pressure Processing of Royal Gala apple, Taylor's Gold pear and Camarosa strawberry purees was carried out to inactivate polyphenoloxidase (PPO). First, 600 MPa enzyme inactivation at room temperature was investigated. After 60 min, strawberry (8% RA, residual activity) and apple (89% RA) PPOs were partially inactivated and pear PPO was not inactivated, demonstrating the high variability in the resistance of different fruits' PPOs. Then, the fruit purees were submitted to 600 MPa combined with mild heat, and the PPO inactivation kinetics was modeled. The pear PPO was found to be resistant even after 60 min 600 MPa-71 degrees C …

Co-Production Of Hydrogen And Carbon Nanofibers From Methane Decomposition Over Zeolite Y Supported Ni Catalysts

Faculty of Engineering University of Malaya

The objective of this paper is to study the influences of different operating conditions on the hydrogen formation and properties of accumulated carbon from methane decomposition using zeolite Y supported 15% and 30% Ni, respectively, at a temperature range between 500 and 650 degrees C in a pilot scale fixed bed reactor. The temperature ramp was showed a significant impact on the thermo-catalytic decomposition (TCD) of methane. An optimum temperature range of 550-600 degrees C were required to attain the maximum amount of methane conversion and revealed that at 550 and 600 degrees C, catalyst showed longer activity for the …

Separation Of The Petroleum System, Ali Ibrahim Neamah

Ali Ibrahim Neamah

This study discusses the overall process of crude oil separation as well as the necessary equipment used in the process. Also discussed and analyzed are potential issues seen in the crude oil extraction process. Reasons why these operation problems may occur are analyzed as well as treatment options for such occurring issues are discussed for employees and students alike. This research is based off of personal involvement at the Nasiriyah Degassing Station located in Dhi Qar, Iraq.

Self-Regulated Solar Lighting System, Innovative Research Publications Irp India, Mr. Ramesh C R, Prof.Lyla B Das

Innovative Research Publications IRP India

Electricity is a prime concern in today’s world. On observing the path through which we travel daily we can see that a lot of electricity is wasted by glowing sodium wafer lamps and even the traditional tube lights on the electric posts at unnecessary intervals. The self regulating solar system enters into action and exits from functioning depending upon the output from the Day/Night sensing unit. Once the unit indicates arrival of night then the system turns ON, the controlling unit thereafter controls the illumination level of the lamp depending upon the outputs of interruption detector, temperature sensor & real …

Review Of Improvements In Wire Electrode Properties For Longer Working Time And Utilization In Wire Edm Machining

Faculty of Engineering University of Malaya

Wire electrical discharge machining (WEDM) is an important technology, which demands high-speed cutting and high-precision machining to realize productivity and improved accuracy for manufacturing hard materials. WEDM has experienced explosive growth and complexity of equipment as well as rising demand for the basic process tool (the wire electrode). Greater taper angles, thicker workpieces, automatic wire threading, and long periods of unattended operation make the selection of the ideal wire a much more critical basis for achieving successful operation. This paper focuses on the evolution of EDM wire electrode technologies from using copper to the widely employed brass wire electrodes and …

Contribution Of Radicals And Ions In Catalyzed Growth Of Single-Walled Carbon Nanotubes From Low-Temperature Plasmas, Z Marvi, S Xu, G Foroutan, Kostya Ostrikov

Australian Institute for Innovative Materials - Papers

The growth kinetics of single-walled carbon nanotubes (SWCNTs) in a low-temperature, low-pressure reactive plasma is investigated using a multiscale numerical simulation, including the plasma sheath and surface diffusion modules. The plasma-related effects on the characteristics of SWCNT growth are studied. It is found that in the presence of reactive radicals in addition to energetic ions inside the plasma sheath area, the effective carbon flux, and the growth rate of SWCNT increase. It is shown that the concentration of atomic hydrogen and hydrocarbon radicals in the plasma plays an important role in the SWCNT growth. The effect of the effective carbon …

Superior Critical Current Density Obtained In Mg11b2 Low Activation Superconductor By Using Reactive Amorphous 11b And Optimizing Sintering Temperature, Fang Cheng, Yongchang Liu, Zongqing Ma, Huijun Li, Md Shahriar Hossain

Australian Institute for Innovative Materials - Papers

The un-doped Mg¹¹B2 and Cu-doped Mg¹¹B2 bulks using ¹¹B as a boron precursor were fabricated by solid-state reaction and sintered at different temperature in present work. By analyzing the sintering process, it was found that ¹¹B original powder is more reactive and can react with Mg severely even at low temperature before Mg melting, which leads to the formation of refined Mg¹¹B2 grains. Consequently, the critical current density of Mg¹¹B2 sample prepared in this work is higher than that of natural MgB2. Furthermore, it was found that proper Cu addition …

High Temperature Dislocation Structure And Nbc Precipitation In Three Ni-Fe-Nb-C Model Alloys, Andrii Kostryzhev, Parvez Mannan, Olexandra Marenych

Faculty of Engineering and Information Sciences - Papers: Part A

In this original work, the dislocation structure and NbC precipitation were investigated in three Ni-based alloys (70Ni-Fe-0.331Nb-0.040C, 70Ni-Fe-0.851Nb-0.114C and 70Ni-Fe-1.420Nb-0.157C, wt%) thermomechanically processed in the temperature range of 1250-1075 °C. The dislocation structure inhomogeneity (dislocation networks and cell walls), which we observed in the middle and high Nb+C alloys, resulted from the dislocation pile-ups in the vicinity of >200 nm NbC particles. The dislocation density around >200 nm particles exceeded the average values by 5-7 times, and that in the cell walls might exceed the average values by 10 times. Twins and stacking faults were observed in all alloys after …

Significantly Enhanced Critical Current Density In Nano-Mgb2 Grains Rapidly Formed At Low Temperature With Homogeneous Carbon Doping, Yongchang Liu, Feng Lan, Zongqing Ma, Ning Chen, Huijun Li, Shaon Barua, Dipakkumar Patel, Md S. Hossain, S Acar, Jung Ho Kim, S X. Dou

Australian Institute for Innovative Materials - Papers

High performance MgB₂ bulks using carbon-coated amorphous boron as a boron precursor were fabricated by Cu-activated sintering at low temperature (600 °C, below the Mg melting point). Dense nano-MgB₂ grains with a high level of homogeneous carbon doping were formed in these MgB₂ samples. This type of microstructure can provide a stronger flux pinning force, together with depressed volatility and oxidation of Mg owing to the low-temperature Cu-activated sintering, leading to a significant improvement of critical current density (J_c) in the as-prepared samples. In particular, the value of J_c for the carbon-coated (Mg …

Packaged Silica And Chalcogenide Microspheres And Their Applications For Telecommunications, Pengfei Wang

Conference papers

To investigate, both theoretically and experimentally, packaged silica and chalcogenide microsphere and their potential applications in telecommunications.

Prosthetic Thermal Management Device, Garrett Dowd

Williams Honors College, Honors Research Projects

High temperatures in lower-limb prosthetics can lead to poor user skin conditions and mechanical slippage between the user’s limb and the prosthetic. This report presents an air-cooling device for a lower-limb prosthesis. This device’s purpose is to maintain a constant skin-prosthesis interface temperature. A compact heat sink and small fan were used to transfer the bio-heat to the ambient surroundings. By changing the power of the fan, the thermal resistance of the whole system can be adjusted to match various thermal loads and environmental temperatures. Heat pads were used to mimic the heat generation of a residual limb, and cooling …

Harvesting Temperature Fluctuations As Electrical Energy Using Torsional And Tensile Polymer Muscles, Shi Hyeong Kim, Marcio Dias Lima, Mikhail E. Kozlov, Carter S. Haines, Geoffrey M. Spinks, Shazed Aziz, Changsoon Choi, Hyeon Jun Sim, Xuemin Wang, Hongbing Lu, Dong Qian, John D. W Madden, Ray H. Baughman, Seon Jeong Kim

Australian Institute for Innovative Materials - Papers

Diverse means have been deployed for harvesting electrical energy from mechanical actuation produced by low-grade waste heat, but cycle rate, energy-per-cycle, device size and weight, or cost have limited applications. We report the electromagnetic harvesting of thermal energy as electrical energy using thermally powered torsional and tensile artificial muscles made from inexpensive polymer fibers used for fishing line and sewing thread. We show that a coiled 27 μm-diameter nylon muscle fiber can be driven by 16.7 °C air temperature fluctuations to spin a magnetic rotor to a peak torsional rotation speed of 70 000 rpm for over 300 000 heating-cooling …

Harvesting Temperature Fluctuations As Electrical Energy Using Torsional And Tensile Polymer Muscles, Shi Hyeong Kim, Marcio Dias Lima, Mikhail E. Kozlov, Carter S. Haines, Geoffrey M. Spinks, Shazed Aziz, Changsoon Choi, Hyeon Jun Sim, Xuemin Wang, Hongbing Lu, Dong Qian, John D. W Madden, Ray H. Baughman, Seon Jeong Kim

Australian Institute for Innovative Materials - Papers

Diverse means have been deployed for harvesting electrical energy from mechanical actuation produced by low-grade waste heat, but cycle rate, energy-per-cycle, device size and weight, or cost have limited applications. We report the electromagnetic harvesting of thermal energy as electrical energy using thermally powered torsional and tensile artificial muscles made from inexpensive polymer fibers used for fishing line and sewing thread. We show that a coiled 27 μm-diameter nylon muscle fiber can be driven by 16.7 °C air temperature fluctuations to spin a magnetic rotor to a peak torsional rotation speed of 70 000 rpm for over 300 000 heating-cooling …

Improvement In Structure And Superconductivity Of Bulk Fese0.5te0.5 Superconductors By Optimizing Sintering Temperature, Ning Chen, Yongchang Liu, Zongqing Ma, Liming Yu, Huijun Li

Australian Institute for Innovative Materials - Papers

Sintering temperature plays a vital role in the evolution of phase structure and microstructure in polycrystalline FeSe0.5Te0.5 bulks fabricated by the two-step sintering method, and thus significantly influences their superconducting properties. Elevated sintering temperature (600-700°C) at second step facilitates the substitution of Te into the superconducting phase, which leads to the increased lattice distortion and thus contributes to the enhancement of superconductivity (the value of Tc reaches 15.6K). At the same time, the accelerated growth of the superconducting grains and the improved homogeneity motivated by elevated sintering temperature serve as the main reason for the sharp superconducting transition.