Mechanical Engineering Commons^™

Wavelenght-Dispersive X-Ray Flourescence Accuration, H. Widyatmoko

Makara Journal of Technology

Wavelenght–Dispersive X-Ray Flourescence Accuration. X-Fuorescence spectrometry is a method, which is increasingly applied in the geochemical analysis. X-Fuorescence spectrometry is classified under two categories – WDXRF (wavelenght – dispersive X-ray fluorescence spectrometer) and EDXRF (energy-dispersive X – ray fluorescence spectrometer). WDXRF can be configured as a sequential spectrometer , a simultaneous spectrometer or a hibrid instrument, which combines the advantages of the simultaneous and sequential spectrometers into one instrument. Each instrument is different in some characteristics, and each has applications for which it is specifically suited. In this investigation sequential spectrometer PW 1450 was used to analyze the major, minor …

Secondary Flow Experimental Study For Axial Compressor Cascade Strong Stagger With And Without Tip- Clearance: Static Pressure Distribution On Blade Surface, Syamsuri Syamsuri

Makara Journal of Technology

Secondary Flow Experimental Study for Axial Compressor Cascade Strong Stagger With and Without Tip- Clearance: Static Pressure Distribution on Blade Surface. The performance of blade cascade is influenced by the growth and boundary layer’s separation along blade surface and endwall (casing and hub). The secondary flow which happens near hub and casing compressors is three dimentional flow separation phenomenon comes from interaction blade boundary layer with casing and hub boundary layers in the compressor. The secondary flow causes secondary losses, blockage effect, and turning angle (deflection) distribution along blade span. The result of the research shows that the increase of …

Effect Of Photoperiodicity On Co2 Fixation By Chlorella Vulgaris Buitenzorg In Bubble Column Photobioreactor For Food Supplement Production, Anondho Wijanarko, Dianursanti Dianursanti, Arief Budi Witarto, Roekmijati Widaningroem Soemantojo

Makara Journal of Technology

To reduce the level of CO2 content in air, effort on converting CO2 to useful products is required. One of the alternatives includes CO2 fixation to produce biomass using Chlorella vulgaris Buitenzorg. Chlorella vulgaris Buitenzorg is applied for production of food supplement. Chlorella vulgaris Buitenzorg is also easy to handle due to its superior adaptation. Currently, Chlorella vulgaris Buitenzorg has been analyzed by some experts for its cellular composition, its ability to produce high quality biomass and the content of essential nutrition. A series of experiments was conducted by culturing Chlorella vulgaris Buitenzorg using Beneck medium in bubbling column photobioreactor. …

Synthesize Of Emulsion Polymer Latex For Sub-Grade Cbr Improvement In The Road Construction, Keba Moto, V. Julian, Syamsudin Syamsudin, T. A. Wiradi, S. R. Wijaya

Makara Journal of Technology

Synthesize of emulsion polymer latex for sub-grade CBR improvement in the road construction. Latex polymer for California Bearing Ratio (CBR) enhancement in sub-grade soil of road building has been prepared by emulsion polymerizations technique. The prepared polymer then characterize by Fourier Transform Infrared (FTIR). For application purpose, CBR test was done to the compacted polymer added-soil. The CBR test is done also for both soaked and unsoaked samples. It is found that our latex polymer is better then other imported latex polymer. For the latex polymer, which is design to have Temperatur glass (Tg) around 9.8-19.6o, indicating the formation of …

Assessing Six Residential Ventilation Techniques In Hot And Humid Climates, Florida Solar Energy Center, Neil Moyer

FSEC Energy Research Center®

The addition of mechanical ventilation air to "tight" homes in hot and humid climates may adversely impact health, building durability, comfort and energy use by raising indoor humidity levels (RH) above 50%. High indoor humidity has been linked to microbial growth, building material decay, discomfort, and increased energy use (Moyer, et al, 2001). High indoor humidity in "tight" homes with mechanical ventilation has been documented in various Building America projects in hot humid locations (Rudd 2003).

The research described here quantifies the energy use, and humidity impacts of six mechanical ventilation strategies installed serially in a new, Energy Star Manufactured …

Wire Bonding Challenges In Optoelectronics Packaging, Jianbiao Pan, Patrice Fraud

Industrial and Manufacturing Engineering

Wire bonding has been used in integrated circuit (IC) packaging for many years. However, there are many challenges in wire bonding for optoelectronics packaging. These challenges include bonding on sensitive devices, bonding over cavity, bonding over cantilevel leads and bonding temperature limitations. The optoelectronics package design brings another challenge, which requires wire bonding to have deep access capability. In this paper, the wire bonding technologies are reviewed and ball bonding and wedge bonding are compared. The variables that affect the wire bonding process are then discussed. Finally, the challenges of wire bonding in optoelectronics packaging are presented in detail.

The Effect Of Heterogeneity On Plane Wave Propagation Through Layered Composites, X. Chen, Namas Chandra

Department of Mechanical and Materials Engineering: Faculty Publications

When laminated composites are subjected to impact loading, the material response is critically determined by the interactions of multiple waves generated at the laminate interfaces. Due to the high complexity arising from the architectural details of composites, layered heterogeneous materials have been studied as the model system to understand the impact behavior of engineering composites. Previously, the present authors have developed an analytical solution to the problem of plate impact of layered systems; plate impact test is a standard boundary value problem used to study high velocity impact behavior both in the elastic and shock wave regimes. In this paper, …

Percolation Paths Of Three-Dimensions In Sensitized Stainless Steel, Alisa J. Millar Henrie

Faculty Publications

The study of three-dimensional percolation paths through materials is important in its contribution to understanding defect sensitive properties of materials. This work shows the importance of grain boundary character in modeling defect sensitive boundaries. Also presented are trends of percolation of sensitized grain boundaries in 304 stainless steel (304SS). Of particular interest is how open paths form in a three-dimensional model created through serial sectioning. Evidence is presented that triple or quadruple points that contain typically two boundaries with special character that intersect the percolation path break up the path. Some boundaries with no known special qualities; they are not …

Embrittlement And Localized Corrosion In Alloy Ht-9, Sudheer Sama

UNLV Theses, Dissertations, Professional Papers, and Capstones

This investigation is focused on the evaluation of stress corrosion cracking (SCC), hydrogen embrittlement (HE) and localized corrosion susceptibility of Alloy HT -9 in neutral and acidic solutions at 30, 60 and 90°C. Constant-load and slow-strain-rate (SSR) testing techniques were used to evaluate the SCC and HE behavior of this alloy by using smooth and notched tensile specimens. Hydrogen effect on the cracking behavior was evaluated by applying cathodic (negative) potential to the test specimens. Localized corrosion susceptibility was evaluated by cyclic potentiodynamic polarization technique. The results of constant load SCC testing showed a threshold stress at 80% of the …

Environment-Induced Degradations In A Target Structural Material For Transmutation Applications, Ramprashad Prabhakaran

UNLV Theses, Dissertations, Professional Papers, and Capstones

This investigation is focused on the evaluation of stress corrosion cracking (SCC) and localized corrosion behavior of Type 422 stainless steel in aqueous environments at ambient and elevated temperature. The results of constant load SCC testing using smooth specimens showed no failure in the neutral solution but a threshold stress of 97 ksi was observed in the 90°C acidic environment. SCC testing by the slow-strain-rate test method indicate that the time-to-failure, true failure stress and ductility parameters were gradually reduced with increasing temperature, showing more pronounced effect in the acidic solution. The application of a controlled cathodic potential showed further …

Fully Compliant Tensural Bistable Mechanisms (Ftbm) With On-Chip Thermal Actuation, Daniel L. Wilcox

Theses and Dissertations

The Fully compliant Tensural Bistable Mechanism (FTBM) class is introduced. The class consists of fully compliant linear bistable mechanisms that achieve much of their displacement and bistable behavior through tension loading of compliant segments. Multiple topologies of designs arising from the FTBM class were designed using a finite element analysis (FEA) model with optimization. In a coupled design approach, thermal actuators were optimized to the force and displacement requirements of the bistable mech-anisms, and selected FTBM devices were combined in switching systems with the result-ing Thermomechanical In-plane Microactuators (TIMs) and Amplified Thermomechanical In-plane Microactuators (ATIMs). Successful on-chip actuation was demonstrated. …

A Review Of Hot Water Draw Profiles Used In Performance Analysis Of Residential Domestic Hot Water Systems, Florida Solar Energy Center, Philip W. Fairey

FSEC Energy Research Center®

As a result of efforts on the part of various organizations to improve the specifications for performance-based analysis of energy use in residences, the literature on residential hot water use has been reviewed, specifically as it relates to typical hot water use draw profiles. A number of daily hot water use draw profiles have been identified and reviewed.

Effect Of Chromium-Gold And Titanium-Titanium Nitride-Platinum-Gold Metallization On Wire/Ribbon Bondability, Jianbiao Pan, Robert M. Pafchek, Frank F. Judd, Jason Baxter

Industrial and Manufacturing Engineering

Gold metallization on wafer substrates for wire/ribbon bond applications require good bond strength to the substrate without weakening the wire/ribbon. This paper compares the ribbon bondability of Cr/Au and Ti/TiN/Pt/Au metallization systems. Both chromium and titanium are used to promote adhesion between substrates and sputtered gold films. Both can diffuse the gold surface after annealing and degrade the wire/ribbon bondability. Restoring bondability by ceric ammonium nitrate (CAN) etch was investigated. Experiments were conducted to investigate the effect of Cr/Au and Ti/TiN/Pt/Au, annealing, and CAN etch processes on 25.4 times; 254 μm (1 × 10 mil) ribbon bonding. All bonds were …

Assuring Power In A Disaster And Providing Energy Security, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Daily use of a myriad of electrical and electronic devices has contributed to a steadily increasing dependence on electric power. The degree of importance of electricity is temporarily highlighted with any type of power outage, whether caused by a disaster as destructive as a Hurricane Andrew or as minor as an afternoon thunderstorm knocking down local utility lines. After September 11, terrorism added a new dimension to our definition of energy security. While the American public is dependent on utility providers to meet energy needs, it is the right and the responsibility of each citizen to become aware of energy …

Flexible Machine Tool Control For Direct, In-Process Dimensional Part Inspection, Tyler Addison Davis

Theses and Dissertations

For some time now coordinate measuring machines have been an integral part of the shop floor. The goal has been to make coordinate measuring machines (CMMs) into tools that can easily be used by machinists to improve their manufacturing capabilities. The value of a CMM as a quality control tool is undisputed. Now efforts are being made to further reduce the time and cost of measurement by reducing the physical distance between machining and measuring processes. The ability to reduce that distance to zero and measure a part directly on the chip-making machine has been a goal for many years. …

Admittance Selection For Force-Guided Assembly Of Polyhedral Parts In Single-Point Contact, Shuguang Huang, Joseph M. Schimmels

Mechanical Engineering Faculty Research and Publications

The selection of the proper admittance is important in achieving force-guided assembly. This paper identifies procedures for selecting the appropriate spatial admittance to achieve reliable force-guided assembly of polyhedral parts for single-point frictionless contact cases. Sets of conditions that are imposed on the admittance matrix for different types of single-point contact are presented. These conditions ensure that the motion that results from contact reduces part misalignment in the selected contact state. We show that, for bounded misalignments, if an admittance satisfies the misalignment-reduction conditions at a finite number of contact configurations, then the admittance also satisfy the conditions at all …

Pressure Distribution Around Spherical Distal Ball-Tip In Ultrasound Angioplasty, Graham Gavin, Garrett B. Mcguinness, Finbar Dolan, M.S. J. Hashmi

Conference Papers

INTRODUCTION Ultrasound Angioplasty has been shown to be effective in the removal and re-canalising of blockages in arteries (Siegel RJ, 1993). By delivering therapeutic ultrasound to the blockage, via a wire waveguide to a ball-tip, the lesion or thrombus is affected by pressure waves, micro streaming, cavitation and direct contact with the oscillating ball-tip. Most work to date has concentrated on a spherical ball-tip geometry at the distal end of the wire waveguide (Steffen, 1994 and Rosenschein, 1996). Tip displacements usually lie between 10 - 100m (peak-to peak) and ball tip diameters between 1 - 2mm (Atar, 1999 and Yock, …

Flexible Roofing Facility: 2003 Summer Test Results, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

The Flexible Roof Facility (FRF) is a test facility in Cocoa, Florida designed to evaluate five roofing systems at a time against a control roof with black shingles and vented attic (Figure E-1). The testing evaluates how roofing systems impact summer residential cooling energy use and peak demand. In the summer of 2003, the following roofing systems were tested: Galvalume® unfinished 5-vee metal with vented attic (2nd year of exposure); sealed attic with proprietary configuration; high reflectance brown metal shingle with vented attic; galvanized unfinished 5-vee metal with vented attic (2nd year of exposure); black shingles with standard attic ventilation …

Accreditation Of Mechanical Engineering Education In The Usa In 21st Century, Said Shakerin

All Faculty Articles - School of Engineering and Computer Science

Accreditation board for engineering and technology (ABET) in the USA made a paradigm shift in its accreditation criteria for evaluation of engineering education in 2000. Under the new criteria, called ABET2000, educational programs are evaluated based on thir outcomes as opposed to their contents, which were the mail focus under the old criteria. Engineering education has thus undergone major changes. In this paper, ABET s purpose, its criteria, and the evaluation process are explained, followed by specific industrial.

Field Effect Control Of Electrokinetic Transport Phenomena In Nanofluidics, Song Xue

Mechanical & Aerospace Engineering Theses & Dissertations

Naturally nanofluidics has applications demanding the samples to be handled in exceedingly small quantities due to the small size of the fluidic channels in nanofluidic devices, such as characterization of single biomolecules. Fluids confined in channels of nanometer characteristic dimensions exhibit physical behaviors not observed in large conduits. Charge properties of the nanochannel wall in contact with an aqueous solution play essential roles in the involved electrokinetic transport phenomena occurring in nanofluidic devices. In addition to tuning the charge properties of the nanofluidic channel wall by adjusting the solution properties such as pH and background salt concentration, field effect transistor …

Uncertainty Propagation And Robust Design In Cfd Using Sensitivity Derivatives, Michele M. Putko

Mechanical & Aerospace Engineering Theses & Dissertations

This study investigates and demonstrates a methodology for uncertainty propagation and robust design in Computational Fluid Dynamics (CFD). Efficient calculation of both first- and second-order sensitivity derivatives is requisite in the proposed methodology. In this study, first- and second-order sensitivity derivatives of code output with respect to code input are obtained through an efficient incremental iterative approach.

An approximate statistical moment method for uncertainty propagation is first demonstrated on a quasi one-dimensional (1-D) Euler CFD code. This method is then extended to a two-dimensional (2-D) subsonic inviscid model airfoil problem. In each application, given statistically independent, random, normally distributed input …

Laser Scanning Thermal Probe: A Novel Approach To Non-Destructive Evaluation, Jacob Kephart, John Chen, Hong Zhang

Mechanical Engineering

Structuraldefects such as cracks have recently been identifiable through anew nondestructive evaluation (NDE) technique know as sonic IR orthermosonics. However, these defects are depicted through thermal imagining systemas localized "hot spots" indicating a general location of adefect without an accurate portrayal of the dimensions or shapeof the defect. This paper demonstrates a new technique calledLaser Scanning Thermal Probe, LSTP, which utilizes thermography with theuse of heat application in strategic locations to observe spatialheat flow patterns. The LSTP records heat propagation across adefect area previously identified through the thermosonic technique. Thermal gradientswill occur as heat traverses the crack and provide informationto …

The Development Of Web-Based Aerobic And Anaerobic And Muscle Static Work Capacity Modules Using Legacy Cycle Approach, Anant Ravindra Deshpande

Theses and Dissertations - UTB/UTPA

The Legacy cycle is an instructional model that emphasizes inquiry. Learners are faced with progressively complex challenges. For each challenge, learners generate initial thoughts on how they might react to the challenges. In this thesis, a web based instructional method that evaluates interactivity and motivation is presented. The system presented in the thesis helps student to integrate the use of legacy cycle approach in the regular study of aerobic and anaerobic and muscle static work capacity modules. The thesis also focuses on developing modules which contain challenges encompassing various sections, which helps student as an asynchronous learning tool, intended for …

Measuring The Five-Parameter Grain-Boundary Distribution From Observations Of Planar Sections, Brent L. Adams, Bassem S. El-Dasher, Gregory S. Rohrer, David M. Saylor

Faculty Publications

One of the authors (DMS) thanks his colleagues at NIST, Edwin R. Fuller, Jr. and Grady S. White, for their helpful advice and criticisms, as well as Mark D. Vaudin and James A. Warren for their critical review of this manuscript. This work was supported at CMU by the MRSEC program of the National Science Foundation under Award No. DMR-0079996. A sterological method is described for estimating the distribution of grain-boundary types in poly-crystalline materials on the basis of observations from a single planar section. The grain-boundary distribution is expressed in terms of five macroscopically observable parameters that include: three …

New Stereology For The Recovery Of Grain-Boundary Plane Distributions In The Crystal Frame, Brent L. Adams, Ryan J. Larsen

Faculty Publications

One of the authors (RJL) is grateful to the Office of Naval Research for fellowship support. BLA acknowledges the support of the NSF through the Materials Research Science and Engineering Center, Carnegie Mellon University (Grant No. DMR-0079996). A new experimental method is given for recovering the probability-distribution function Sv(ns/g). The function Sv(na/g) is the grain-boundary area per unit volume as a function of grain-boundary plane orientation (na), given a lattice misorientation (g) between the adjoining grains. The grain-boundary normal (na) is expressed in the crystal frame in which the misorientation g originates. The proposed method recovers the three-dimensional Sv(na/g) function …

Unmanned Air Vehicle Testbed For Cooperative Control Experiments, Timothy W. Mclain, Randal W. Beard

Faculty Publications

This paper describes the MAGICC Lab unmanned air vehicle (UAV) testbed at Brigham Young University. Motivation for pursuing experimental research with UAVs is given as well as a historical perspective of the UAV testbed development. Lessons learned through the development and use of the testbed over the past several years are summarized.

A Genetic Algorithm Approach For Model Reference Adaptive Control Of Ionic Polymer Metal Composites, Brijesh C. Lavu, Marco P. Schoen, Ajay Mahajan

Mechanical Engineering Faculty Research

Electroactive polymers undergo physical deformation to external voltage stimuli. These electrically activated polymers possess extraordinary features making them capable as lightweight sensors and actuators in manifold applications. The characteristics of applied voltage and environmental conditions, especially the moisture content surrounding the polymer, have a combined influence on the dynamical behavior of these polymers. In order to characterize these polymers under varying environmental conditions, this paper discusses the experimental procedure and modeling techniques used to derive a representative model. Ionic polymer metal composite polymers are used for this humidity relative electrodynamical study. Insight on the numerous applications of electroactive polymers as …

Optimal Design Of Low Order Controllers Satisfying Sensitivity And Robustness Constraint, Mark L. Nagurka, O. Yaniv

Mechanical Engineering Faculty Research and Publications

The set of all stabilizing controllers of a given low order structure that guarantee specifications on the gain margin, phase margin and a bound on the sensitivity corresponds to a region in n-dimensional space defined by the coefficients of the controllers. For several practical criteria defined in the paper it is shown that the optimal controller lies on the surface of that region. Moreover, it is shown how to reduce that region to avoid actuator saturation during operation.

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.

High Temperature Heat Exchanger Project: Quarterly Progress Report April 1, 2004 Through June 30, 2004, Anthony Hechanova

Publications (NSTD)

UNLV hosted a meeting on NHI Materials and Heat Exchanger Design on Monday, May 17. Paul Pickard (Sandia National Lab) and Bill Corwin (Oak Ridge National Lab) facilitated the meeting. The purpose of the meeting was to summarize the hydrogen materials and heat exchanger requirements and priorities for UNLV staff and their collaborators to support the research proposal solicitation for the UNLV Research Foundation HTHX program. Attendance was heavier than anticipated and required a change of venue to accommodate the crowd of over 30.