Engineering Commons^™

Design And Implementation Of 1-2 Ghz Stepped Frequency Gpr For Buried Metal Detection, Joko Suryana, Andriyan B. Suksmono, Tati R. Mengko

Makara Journal of Technology

Design and Implementation of 1-2 GHz Stepped Frequency GPR for Buried Metal Detection. In this paper, we describe the design and realization steps of 1 – 2 GHz SFGPR (Stepped Frequency Ground Penetrating Radar) transceiver for metal detection under the ground. Before using prototyped GPR for detecting the metal under the ground, several of calibration processes must be performed, namely phase calibration and monocycle pulse waveform calibration. After completing the calibrations, this prototyped GPR would be ready for detecting a hidden object such as a metal plate 5 cm under the ground in our small test range size 25 cm …

Simultaneous Treatment Of Organic (Phenol) And Heavy Metal (Cr6+ Or Pt4+) Wastes Over Tio2, Zno-Tio2 And Cds-Tio2 Photocatalysts, Slamet Slamet, R. Arbianti, Daryanto Daryanto

Makara Journal of Technology

Simultaneous Treatment of Organic (Phenol) and Heavy Metal (Cr6+ or Pt4+) Wastes over TiO2, ZnO-TiO2 and CdS-TiO2 Photocatalysts. Treatment of heavy metal (Cr6+ and Pt4+) and organic (phenol) wastes has been studied using the relatively new method, i.e. simultaneous photocatalytic process over TiO2 photocatalysts in the batch photoreactor. Following the photocatalytic reduction of the heavy metal wastes, recovery of Cr and Pt was carried out by precipitation and leaching method, respectively. The experimental results show that in the simultaneous photocatalytic system, there is a synergism effect between the photocatalytic reduction of heavy metal waste (Cr6+ or Pt4+) and the oxidation …

Synthesis Of Fuel Cell Membrane: Copolymerization Of Styrene On Etfe Film By Grafted Pre-Irradiation, Yohan Yohan, Rifai M. Nur, Lilik Hendrajaya, E. S. Siradj

Makara Journal of Technology

Synthesis of Fuel Cell Membrane: Copolymerization of Styrene on ETFE Film by Grafted pre-Irradiation. Preirradiation Grafting styrene monomer on ETFE film has been prepared. Research has been performed by γ-ray radiation at various total dose from 2.5 – 12.5 kGy and various dose rate from 1.3 – 1.9 kGy/hour. Irradiated copolymer is then grafted by styrene monomer in various solvent: ethanol, 2-propanol, and toluene, various concentration from 20 – 70% volume, various temperature from 50 – 90oC, and various grafting time from 2 – 12 hours. The results showed that percent of grafting is increase with increase of total dose …

Design Of Generating Dual Frequency Operation For Triangular Microstrip Antenna Using Electromagnetic Coupling, Indra Surjati, Eko Tjipto Rahardjo, Djoko Hartanto

Makara Journal of Technology

Design of Generating Dual Frequency Operation for Triangular Microstrip Antenna Using Electromagnetic Coupling. A new design is proposed in this paper by applying a pair of slits using a microstrip feed line. Therefore the microstrip line feeding system is electromagnetically coupled to the patch. The antenna works at two different frequencies in the range from 2 GHz to 4 GHz (S band frequency). The results of the simulation shows that the dual frequency operation can be created when the slit width is 1 mm and the height of the slits ranges from 10 mm to 14 mm with inter slit …

Development Of Low Frequency Vibration Method Of Direct-Write Deposition Relevant To Layer Manufacturing Application, Susilo Adi Widyanto, Alva Edy Tontowi, Jamasri Jamasri, Heru Santosa Budi Rochardjo

Makara Journal of Technology

The research of deposition process is the first step in development process of multi materials selective laser sintering. The deposition process enables to settle multi materials powder in horizontal formation on one layer. In this research we use low frequency (70 - 200Hz) to vibrate a hopper nozzle in which powder is settled. The research method consists of two steps, the first step is to determine flow-ability parameters and the second is to join flow ability parameter with other parameters such that the line width can be controlled. The results show that the line width depends on uniformity of particle …

Design Of Product Placement Layout In Retail Shop Using Market Basket Analysis, Isti Surjandari, Annury Citra Seruni

Makara Journal of Technology

Retailing is an industry with high level of competition. It is a customer-based industry which depends on how it could be aware of what the customers’ needs and requirements are. One technique most used in supermarkets is the mix merchandise. The purpose of this paper is to identify associated products, which then grouped in mix merchandise with the use of market basket analysis. This association between products then will be applied in the design layout of the product in the supermarket. The process of identifying the related products bought together in one transaction is done by using data mining technique. …

Production Hydrogen And Nanocarbon Via Methane Decomposition Using Ni-Based Catalysts. Effect Of Acidity And Catalyst Diameter, Widodo W. Purwanto, M. Nasikin, E. Saputra, L. Song

Makara Journal of Technology

Objectives of this research are mainly to study impacts of acidity strength (by varying amount of precipitant and loading Al-Si) and the effect of nickel particle size (by varying calcinations temperature) on decomposition reaction performances. In this research, high-nickel-loaded catalyst is prepared with two methods. Ni-Cu/Al catalysts were prepared with co-precipitation method. While the Ni-Cu/Al-Si catalyst were prepared by combined co-precipitation and sol-gel method. The direct cracking of methane was performed in 8mm quartz fixed bed reactor at atmospheric pressure and 500-700°C. The main results showed that the Al content of catalyst increases with the increasing amount of precipitant. The …

Grain Boundary Character Distribution In The Haz Of Friction Stir-Processed Al 7075 T7, John A. Basinger

Theses and Dissertations

The heat affected zone (HAZ) of friction stir welded Al 7075 T7 shows diminished corrosion resistance properties when compared with the parent material. Corrosion attack in this region of the weld is primarily intergranular and is associated with the presence of precipitate free zones. Current TEM research conducted at Brigham Young University by Dr. Bin Cai finds a correlation between precipitate free zone (PFZ) width and grain boundary geometry. As both grain boundary geometry and the PFZ are associated with modes of failure in 7XXX aluminum, this paper makes a comparison of grain boundary character distributions (GBCD) in the HAZ …

Methodology For Determining The Variance Of The Taylor Factor: Application In Fe-3%Si, Craig P. Przybyla

Theses and Dissertations

The variance of the Taylor factor due to variations in the microstructure and window size is explored using both a random sampling method and a previously developed statistical relationship. The results from the random sampling method correlated well with the statistical variance relationship when the magnitude of the variance was greater than that of the numerical errors observed in the statistical calculation. An empirical relation was developed to model the results and the constants for this relationship were determined for pseudo-three dimensional Fe-3%Si. Implementation of the statistical variance relationship in true 3D microstructures is not limited by material opacity, since …

Percolation In Two-Dimensional Grain Boundary Structures And Polycrystal Property Closures, David T. Fullwood

Theses and Dissertations

The thesis addresses two topics in the study of material properties as determined by the microstructure. The first topic involves percolation as a tool in relating the grain boundary structure to global properties such as fracture and corrosion resistance. The second investigates optimization techniques in order to find the space of values that properties of a material can take, from consideration of the microstructure. In part I, the applicability of standard lattice percolation models to a random 2-D grain structure is explored. A random network based on the triangle lattice is proposed as a more appropriate model, and results in …

Evaluation Of Cost Effective Sensor Combinations For A Vehicle Precrash Detection System, John Carlin, Charles Birdsong, Peter Schuster, William Thompson, Daniel Kawano

Mechanical Engineering

The future of vehicle safety will benefit greatly from precrash detection -the ability of a motor vehicle to predict the occurrence of an accident before it occurs. There are many different sensor technologies currently available for pre-crash detection. However no single sensor technology has demonstrated enough information gathering capability within the cost constraints of vehicle manufacturers to be used as a stand alone device. A proposed solution consists of combining information from multiple sensors in an intelligent computer algorithm to determine accurate precrash information. In this paper, a list of sensors currently available on motor vehicles and those that show …

Elasticity Of Planar Fiber Networks, Xiangfa Wu, Yuris A. Dzenis

Department of Engineering Mechanics: Faculty Publications

A micromechanics model is proposed for the elasticity of planar fiber networks (FNs). The FN is created by random deposition of linearly elastic straight rods within a region. The rods are bonded rigidly at contacts. Under external in-plane loading, the FN deformation consists of fiber bending, elongation, and contraction. An effective constitutive relation for fiber network is developed by averaging the strain energy dissipated by all possible fiber deformations in all directions. Numerical calculations are performed to analyze the effects of fiber aspect ratio and fiber concentration on the effective stiffness of the planar random FN. Finite element analysis (FEA) …

Load And Resistance Factor Calibration For Wood Bridges, Andrzej S. Nowak, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The paper presents the calibration procedure and background data for the development of design code provisions for wood bridges. The structural types considered include sawn lumber stringers, glued-laminated girders, and various wood deck types. Load and resistance parameters are treated as random variables, and therefore, the structural performance is measured in terms of the reliability index. The statistical parameters of dead load and live (traffic) load, are based on the results of previous studies. Material resistance is taken from the available test data, which includes consideration of the post-elastic response. The resistance of components and structural systems is based on …

Measurements Of Oh Mole Fraction And Temperature Up To 20 Khz By Using A Diode-Laser-Based Uv Absorption Sensor, Terrence Meyer, Sukesh Roy, Thomas Anderson, Joseph Miller, Vlswanath Katta, Robert Lucht, James Gord

Terrence R Meyer

Diode-laser-based sum-frequency generation of ultraviolet (UV) radiation at 313.5 nm was utilized for high-speed absorption measurements of OH mole fraction and temperature at rates up to 20 kHz. Sensor performance was characterized over a wide range of operating conditions in a 25.4 mm path-length, steady, C2H4-air diffusion flame through comparisons with coherent anti-Stokes Raman spectroscopy (CARS), planar laser-induced fluorescence (PLIF), and a two-dimensional numerical simulation with detailed chemical kinetics. Experimental uncertainties of 5% and 11% were achieved for measured temperatures and OH mole fractions, respectively, with standard deviations of <3% at 20 kHz and an OH detection limit of <1 part per million in a l m path length. After validation in a steady flame, high-speed diode-laser-based measurements of OH mole fraction and temperature were demonstrated for the first time in the unsteady exhaust of a liquid-fueled, swirl-stabilized combustor. Typical agreement of 5% was achieved with CARS temperature measurements at various fuel/air ratios, and sensor precision was sufficient to capture oscillations of temperature and OH mole fraction for potential use with multiparameter control strategies in combustors of practical interest.

Energy Efficient Transportation For Florida, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Nearly 30% of energy used in Florida is consumed by our 13 million personal automobiles. Annual gasoline consumption in Florida is about 7.5 billion gallons. Florida also has more registered cars per capita than any other state in the U.S. - nearly one car for each person. The average Florida automobile is driven over 10,000 miles a year burning about 550 gallons of gasoline and costing its owner about $1,500 in fuel costs alone (not to mention payments, insurance, service, repairs, tires, tags, license etc.). Based on a comprehensive analysis, total automobile operating costs average over $850 per month.

Measurement Of Interfacial Shear Mechanical Properties In Thermal Barrier Coating Systems By A Barb Pullout Method, S. Q. Guo, D. R. Mumm, Anette M. Karlsson, Y. Kagawa

Mechanical Engineering Faculty Publications

A test technique has been developed to facilitate evaluation of the fracture characteristics of coatings and interfaces in thermal barrier coating (TBC) systems. The methodology has particular application in analyzing delamination crack growth, where crack propagation occurs under predominantly mode II loading. The technique has been demonstrated by quantitatively measuring the effective delamination fracture resistance of an electron-beam physical vapor deposition TBC.

A Compliant Contact-Aided Revolute Joint, Jessie R. Cannon, Larry L. Howell

Faculty Publications

This paper presents the compliant contact-aided revolute (CCAR) joint, a planar mechanism capable of performing the functions of a bearing and a spring. The pseudo-rigid-body model is used to predict the behavior of the CCAR joint, and this model is validated through the use of finite element analysis and prototype testing. The CCAR joint is shown to have high maximum rotation and lateral stiffness. A case study is presented, and manufacturing considerations are discussed for the macro, meso, and micro scales.

A Compliant Contact-Aided Revolute Joint, Jessie R. Cannon, Larry L. Howell

Faculty Publications

This paper presents the compliant contact-aided revolute (CCAR) joint, a planar mechanism capable of performing the functions of a bearing and a spring. The pseudo-rigid-body model is used to predict the behavior of the CCAR joint, and this model is validated through the use of finite element analysis and prototype testing. The CCAR joint is shown to have high maximum rotation and lateral stiffness. A case study is presented, and manufacturing considerations are discussed for the macro, meso, and micro scales.

Ballistic Imaging Of The Liquid Core For A Steady Jet In Crossflow, Mark A. Linne, Megan Paciaroni, James R. Gord, Terrence R. Meyer

Terrence R Meyer

A time-gated ballistic imaging instrument is used to obtain high-spatial-resolution, single-shot images of the liquid core in a water spray issuing into a gaseous crossflow. We describe further development of the diagnostic technique to improve spatial resolution and present images and statistics for various jets under crossflow experimental conditions (different Weber numbers). Series of these images reveal a near-nozzle flow field undergoing breakup and subsequent droplet formation by stripping. One can also detect signatures of spatially periodic behavior in the liquid core and formation of small voids during breakup.

10 Khz Detection Of Co2 At 4.5 Um By Using Tunable Diode-Laser-Based Difference-Frequency Generation, Terrence R. Meyer, Sukesh Roy, Thomas N. Anderson, Robert P. Lucht, Rodolfo Barron-Jimenez, James R. Gord

Terrence R Meyer

A compact, high-speed tunable, diode-laser-based mid-infrared (MIR) laser source has been developed for absorption spectroscopy of CO2 at rates up to 10 kHz. Radiation at 4.5 um with a mode-hop-free tuning range of 80 GHz is generated by difference-frequency mixing the 860 nm output of a distributed-feedback diode laser with the 1064 nm output of a diode-pumped Nd:YAG laser in a periodically poled lithium niobate crystal. MIR absorption spectroscopy of CO2 with a detection limit of 44 ppm m at 10 kHz is demonstrated in a C2H4-air laminar diffusion flame and in the exhaust of a liquid-fueled model gas-turbine combustor.

High Temperature Heat Exchanger Project: Quarterly Progress Report July 1, 2005 Through September 30, 2005, Anthony Hechanova

Publications (NSTD)

Quarterly Collaboration Meeting. The University of California, Berkeley, hosted a UNLVRF HTHX Project quarterly meeting on September 12. The purpose of the meeting was to promote collaboration and communication among the UNLV Research Foundation partners. Collaborators discussed their research program plan and provided an update on their progress. The next meeting will be in December in Las Vegas, NV hosted by UNLV.

Damage-Induced Modeling Of Asphalt Mixtures Through Computational Micromechanics And Cohesive Zone Fracture, Yong-Rak Kim, D. H. Allen, D. N. Little

Department of Engineering Mechanics: Faculty Publications

This paper presents a computational micromechanics modeling approach to predict damage-induced mechanical response of asphalt mixtures. Heterogeneous geometric characteristics and inelastic mechanical behavior were taken into account by introducing finite element modeling techniques and a viscoelastic material model. The modeling also includes interface fracture to represent crack growth and damage evolution. The interface fracture is modeled by using a micromechanical nonlinear viscoelastic cohesive-zone constitutive relation. Fundamental material properties and fracture characteristics were measured from simple laboratory tests and then incorporated into the model to predict rate-dependent viscoelastic damage behavior of the asphalt mixture. Simulation results demonstrate that each model parameter …

High-Resolution Methods For Measuring The Thermal Expansion Coefficient Of Aerospace Materials, G. Wallace, W. Speer, J. Ogren, Omar S. Es-Said

Mechanical Engineering Faculty Works

Accurately predicting the coefficient of thermal expansion for many aerospace components is critical to ensure proper functionality on orbit where the temperature gradient across a spacecraft can vary from +300 degrees F to -450 degrees F. Under these conditions, the linear approximations generated by theoretical equations no longer hold true, and experimental methods are needed. Although several methods exist for measuring the coefficient of thermal expansion of materials, laser interferometry yields high-resolution results, and the technique is widely accepted in the scientific community.

A Fast Three-Step Phase-Shifting Algorithm, Peisen S. Huang, Song Zhang

Song Zhang

We propose a new three-step phase-shifting algorithm, which is much faster than the traditional three-step algorithm. We achieve the speed advantage by using a simple intensity ratio function to replace the arctangent function in the traditional algorithm. The phase error caused by this new algorithm is compensated for by use of a look-up-table (LUT). Our experimental results show that both the new algorithm and the traditional algorithm generate similar results, but the new algorithm is 3.4 times faster. By implementing this new algorithm in a high-resolution, real-time 3D shape measurement system, we were able to achieve a measurement speed of …

3-D Optical Measurement Using Phase Shifting Based Methods, Peisen S. Huang, Song Zhang

Song Zhang

We review some of our most recent works on 3-D shape measurement using the digital fringe projection and phase-shifting method. First, we introduce the measurement principle and phase-shifting algorithms. Then we discuss an effective method for phase error compensation and a novel idea for system calibration. Finally, we describe a 3-D shape measurement system for high-resolution, real-time 3-D shape acquisition, reconstruction and display.

Repeatable Nanostructures In Dielectrics By Femtosecond Laser Pulse Trains, Lan Jiang, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using the plasma model recent developed by the authors, this study predicts the existence of a constant ablation-depth zone with respect to fluence in femtosecond laser ablation of dielectrics, which has also been observed experimentally. It is found that the value of the constant ablation depth is significantly decreased by the pulse train technology. Repeatable nanostructures can be achieved with the parameters in the constant ablation-depth zone of a femtosecond pulse train, even when the laser system is subject to fluctuations in fluences.

A Fe-Fd Hybrid Scheme For Solving Parabolic Two-Step Micro Heat Transport Equations In Irregularly Shaped Three Dimensional Double -Layered Thin Films Exposed To Ultrashort -Pulse Lasers, Brian R. Barron

Doctoral Dissertations

Multi-layer thin films are important components in many micro-electronic devices. These films are often used when a single film layer is insufficient to meet devices specifications. The continued reduction in component size has the side effect of increasing the thermal stress on these films and consequently the devices they comprise. Understanding the transfer of heat-energy at the micro-scale is important for thermal processing using a pulse-laser. Often, micro-voids may be found in processed devices. This is due to thermal expansion. Such defects may cause an amplification of neighboring defects resulting in severe damage and consequently the failure of the device. …

2005 (Fall) Ensi Informer Magazine, Morehead State University. Engineering Sciences Department

ENSI Informer Magazine Archive

The ENSI Informer Magazine published in the fall of 2005.

Association Between Lower Extremity Posture At Contact And Peak Knee Valgus Moment During Sidestepping: Implications For Acl Injury, Scott G. Mclean, Xuemei M. Huang, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Background. Knee valgus load during sports movement is viewed as an important predictor of non-contact anterior cruciate ligament injury risk, particularly in females. Formulating movement strategies that can reduce valgus loading during these movements therefore appears pertinent to reducing anterior cruciate ligament injury rates. With this in mind, the current study examined the relationship between peak valgus moment and lower extremity postures at impact during a sidestep cutting task.

Methods. Ten male and ten female NCAA athletes had initial contact three-dimensional hip, knee and ankle angles and subsequent knee valgus moment quantified during the execution of (n=10 trials) …

Letter To The Editor, Scott G. Mclean, Jack T. Andrish, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

No abstract provided.