Engineering Commons^™

Toughening Of Poly(L-Lactic Acid) With Cu3Btc2 Metal Organic Framework Crystals, Ajay Kathuria, Mohamad G. Abiad, Rafael Auras

Industrial Technology and Packaging

Poly(l-lactic acid) (PLLA) and metal organic framework (MOF) composites were prepared by melt extrusion of PLLA with 5, 10 and 20% w/w of activated Cu₃(BTC)₂ MOF. The morphology and stability of injection-molded samples were evaluated using thermogravimetric analysis, differential scanning calorimetry (DSC), gel permeation chromatography, X-ray diffraction, and scanning electron microscopy (SEM). The composites showed improved toughness during the tensile tests as compared to the neat PLLA matrix. Toughness mechanism of the composites was studied using SEM and rheological studies. SEM images indicated that cavitation induced by debonding at the interface of PLLA and MOF particles during …

A Finite Element Model Based On Coupled Refined High-Order Global-Local Theory For Static Analysis Of Electromechanical Embedded Shear-Mode Piezoelectric Sandwich Composite Beams With Various Widths, S.B. Beheshti-Aval, S. Shahvaghar-Asl, M. Lezgy-Nazargah, Mohammad N. Noori

Mechanical Engineering

In this study, a new theory for the accurate simulation of the shear-mode behaviour of thin or thick piezoelectric sandwich composite beams is developed. The effects of transverse normal stress and transverse flexibility of layers are considered in the development of the proposed formulation. In order to increase the computational accuracy, all kinematic and stress continuity conditions are satisfied at layer interfaces. Moreover, for the first time, both the electrically induced strain components and the transverse flexibility are taken into account in the proposed formulation. Despite the fact that the number of unknown mechanical parameters in this theory is only …

The Effect Of Distribution On Product Temperature Profile In Thermally Insulated Containers For Express Shipments, Jay Singh, Sanjiv Jaggia, Koushik Saha

Industrial Technology and Packaging

An uninterrupted cold chain is a continual series of storage and distribution activities that maintain a specific temperature or temperature range. Cold chain solutions typically involve excessive packaging to ensure that the desired product temperature is maintained through the distribution process, thereby increasing the logistics-related costs. There is a myriad of solutions available for shipping temperature-sensitive products, including those constructed with a variety of packaging materials as well as refrigerants. Although static characteristics for thermally insulated packaging solutions such as the R-values of package systems as well as the melting points and heat absorption rates of various refrigerants have been …

Bayesian Approach For Uncertainty Analysis Of An Urban Storm Water Model And Its Applications To A Heavily Urbanized Watershed, Misgana K. Muleta, Jonathan Mcmillan, Geremew G. Amenu, Steven J. Burian

Civil and Environmental Engineering

The significance of uncertainty analysis (UA) to quantify reliability of model simulations is being recognized. Consequently, literature on parameter and predictive uncertainty assessment of water resources models has been rising. Applications dealing with urban drainage systems are, however, very limited. This study applies formal Bayesian approach for uncertainty analysis of a widely used storm water management model and illustrates the methodology using a highly urbanized watershed in the Los Angeles Basin, California. A flexible likelihood function that accommodates heteroscedasticity, non-normality, and temporal correlation of model residuals has been used for the study along with a Markov-chain Monte Carlo-based sampling scheme. …

Development Of Numerical Model For Predicting Heat Generation And Temperatures In Msw Landfills, James L. Hanson, Nazli Yesiller, Michael T. Onnen, Wei-Lien Liu, Nicolas K. Oettle, Janelle A. Marinos

Civil and Environmental Engineering

A numerical modeling approach has been developed for predicting temperatures in municipal solid waste landfills. Model formulation and details of boundary conditions are described. Model performance was evaluated using field data from a landfill in Michigan, USA. The numerical approach was based on finite element analysis incorporating transient conductive heat transfer. Heat generation functions representing decomposition of wastes were empirically developed and incorporated to the formulation. Thermal properties of materials were determined using experimental testing, field observations, and data reported in literature. The boundary conditions consisted of seasonal temperature cycles at the ground surface and constant temperatures at the far-field …

Veryifying Liquefaction Remediation Beneath And Earth Dam Using Spt And Cpt Based Methods, Ikram Guettaya, Mohamed Ridha El Ouni, Robb Moss

Civil and Environmental Engineering

This paper presents a case study of liquefaction potential assessment for the foundation of an earth dam in Tunisia. An emphasis was made on the exploration of geotechnical conditions and the interpretation of field tests (SPT and CPT) and the results were collected before and after soil densification using the vibrocompaction technique. The assessment of soil liquefaction triggering was made using deterministic and probabilistic simplified procedures. The results indicate that before vibrocompaction the studied area was prone to the liquefaction hazard. However, after vibrocompaction a significant improvement of the soil resistance reduced the liquefaction potential of the sandy foundation soil. …

Grass Referenced Based Vegetation Coefficients For Estimating Evapostranspiration For A Variery Of Natural Vegetation, Daniel J. Howes, Mariana Pasquet

BioResource and Agricultural Engineering

In arid and semi-arid regions, evapotranspiration from vegetation results in the significant utilization of available water. Accurate estimates of evapotranspiration are required for surface and subsurface hydrologic evaluations as well as irrigation district water balance studies. A significant amount of transferable information exists for irrigated agricultural crops through past and current research in the form of grass or alfalfa reference based crop coefficients (Kc) and basal crop coefficients (Kcb). However, transferable evapotranspiration information on natural vegetation is limited. Much of the work was conducted in the early to mid-1900’s and is presented as actual evapotranspiration from the vegetation at the …

Transferability And Robustness Of Real-Time Freeway Crash Risk Assessment, Cameron Shew, Anurag Pande, Cornelius Nuworsoo

Civil and Environmental Engineering

This study examines the data from single loop detectors on northbound (NB) US-101 in San Jose, California to estimate real-time crash risk assessment models. Method: The classification tree and neural network based crash risk assessment models developed with data from NB US-101 are applied to data from the same freeway, as well as to the data from nearby segments of the SB US-101, NB I-880, and SB I-880 corridors. The performance of crash risk assessment models on these nearby segments is the focus of this research. Results: The model applications show that it is in fact possible to use the …

Workshop A - Implementing The "Design Your Process Of Becoming A World Class Engineering Student" Project, Steffen Peuker, Raymond B. Landis

Mechanical Engineering

Many students come into an engineering program lacking a strong commitment to stay in an engineering program and to graduate with an engineering degree. For students to accomplish the challenging goal of graduating in engineering requires a strong commitment, and behaviors and attitudes to follow through that commitment. To strengthen the commitment of the freshman engineering students an innovative project has been developed. The project challenges students to develop their process to become a "World-Class Engineering Student". Having freshman engineering students design their individually tailored learning process as part of a semester long project in the setting of a student …

Implementing Team Based Learning In Freshmen Engineering Courses, Steffen Peuker, Jennifer Peuker

Mechanical Engineering

Team Based Learning (TBL) is a specific pedagogical tool that emphasizes collaborative learning. Oftentimes TBL is confused with group activities and other active learning strategies involving student teams. TBL is distinct because it follows a prescribed sequence of individual work and group work, and includes immediate feedback as well as peer evaluation. TBL is widely used in medical, pharmacy and nursing schools and the use of TBL in engineering education is growing. The advantages of using TBL in the class room include: (1) students are held accountable for individual (pre-class) and group (in-class) work. (2) The responsibility for learning shifts …

A Class-C Amplifier Linearized By A Constant Conduction Angle Biasing Circuit, Gursewak Singh Rai, Vladimir I. Prodanov, Stephen Garber

Electrical Engineering

This work presents a dynamic biasing topology capable of linearizing a Class-C power amplifier (PA). The topology utilizes a control loop that senses the operating conditions of the power device by means of a scaled replica. The loop operates on the principle of keeping the conduction angle constant and thereby ensuring linearity. The work details some of the design considerations that should prove useful to a designer wanting to implement the topology in an RF integrated circuit. Measurement results from a fully-functional low-frequency prototype bring merit to the topology.

Mechanical Design Of Pird (Principal Investigator Rack Drawer) For Sofia, Hari Prasad Shetty Mr., Murali Krishna Kandlagunta Mrs., John Miles Mr., Zaheer Ali Mr.

STAR Program Research Presentations

SOFIA, the world’s largest airborne observatory with 2.5-meter diameter infrared telescope is equipped with 7 instruments: EXES, FIFI-LS, FLITECAM, FORCAST, GREAT, HAWC, and HIPO. Flying at altitudes between 39,000 and 45,000 feet, SOFIA avoids 99% of the atmospheric water vapor, records and analyzes the infrared radiation from the cosmos. SOFIA is able to observe the occultation of stars by solar system objects. By determining the size, compositions, and atmospheric structures of these objects, SOFIA can help answer the questions on creation and evolution of the universe, formation of the stars and planets, and nature of black hole at the center …

Characterization Of Samples For Optimization Of Infrared Stray Light Coatings, Carey L. Baxter, Rebecca Salvemini, Zaheer A. Ali, Patrick Waddell, Greg Perryman, Bob Thompson

STAR Program Research Presentations

NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) is a converted 747SP that houses a 2.5 m telescope that observes the sky through an opening in the side of the aircraft. Because it flies at altitudes up to 45,000 feet, SOFIA gets 99.99% transmission in the infrared. Multiple science instruments mount one at a time on the telescope to interpret infrared and visible light from target sources. Ball Infrared Black (BIRB) currently coats everything that the optics sees inside the telescope assembly (TA) cavity in order to eliminate noise from the glow of background sky, aircraft exhaust, and other sources. A …

Smart Sampling Of Noble Gases To Detect Underground Nuclear Explosions, Lindsey M. Skelton, Steven Hunter, Charles Carrigan

STAR Program Research Presentations

One element of the Comprehensive Nuclear Test Ban Treaty (CTBT) is the provision for an on site inspection (OSI). The purpose of an OSI is to monitor for the occurrence of an underground nuclear explosion (UNE) in violation of the treaty. Detection of certain rare radioactive noble gases transported to the surface can be an excellent indicator of a UNE. These gases can be very difficult to capture and require specialized sampling methods. This study aims to determine an algorithm that will increase the efficiency of the subsurface gas sampling technique being used to detect UNEs. Continuous sampling of subsurface …

Life Support: Long Term Storage Of Solid Waste In An Enclosed Membrane System, Emmy O. Trieu, Michael Flynn, Rocco Mancinelli

STAR Program Research Presentations

In deep space missions, maintaining life support is of the utmost priority. In such a closed system, human waste must be stored and treated. Simulated feces (ersatz) will be inoculated with microbes representing normal fecal flora, mixed with urine brine and shredded refuse of products typically used in space missions. Composting methods often use alternating layers of waste with scraps of carboniferous materials (finely shredded refuse). By preparing membrane bags with a homogenized ersatz and carboniferous refuse mixture and membrane bags with alternating layers of ersatz and carboniferous refuse, it may be possible to monitor anaerobic thermophillic digestion of the …

If It Isn’T Tested, It Doesn’T Work: Automated Verification Of Sofia Data Handling Software, Garrett Holthaus, Brett Stroozas, Zaheer Ali

STAR Program Research Presentations

This project involves writing code to automate the verification testing of the Data Handling Working Group (DHWG) software tools for the Stratospheric Observatory for Infrared Astronomy (SOFIA). The DHWG tools extract engineering data from SOFIA missions. Engineering data includes a variety of information on the operations and status of SOFIA systems during a flight, including computer network traffic, user commands, and images acquired from cameras mounted on the telescope assembly. It is important to review engineering data because this data can lead to the discovery of any problems or inefficiencies in SOFIA hardware and software. Analysis of engineering data can …

C-Ring Contaminate Identification By Spectroscopy And Elemental Mapping, Thien Q. Vu-Nguyen, Bernice Mills

STAR Program Research Presentations

A silver plated steel c-ring used to seal two steel pieces together was found to have contamination upon disassembly. Auger and x-ray fluorescence spectroscopy and mapping were used to identify the contaminate as molybdenum disulfide lubricant. Recommendations were made to avoid such contamination in the future.

Creating A Package In R, Brit Schneiders, Eric Archer

STAR Program Research Presentations

In a time of increasingly efficient technology and data production, scientists are producing data faster than it can be analyzed. Therefore, user accessibility to data analysis is becoming more and more critical. In general, researchers have a set of raw data and want an efficient means to their final analysis. A package serves as that means by creating a set of functions and making them accessible to the user. Often, a user has a small piece of code to run (a single R script, for example), and that script requires the use of certain functions, which are contained in a …

Characterization Of The Drilling Via The Vibration Augmenter Of Rotary-Drills And Sound Signal Processing Of Impacted Pipe As A Potential Water Height Assessment Tool, Nicholas Morris

STAR Program Research Presentations

The focus of the internship has been on two topics: a) Characterize the drilling performance of a novel percussive augmenter – this drill was developed by the JPL’s Advanced Technologies Group and its performance was characterized; and b) Examine the feasibility of striking a pipe as a means of assessing the water height inside the pipe. The purpose of this investigation is to examine the possibility of using a simple method of applying impacts to a pipe wall and determining the water height from the sonic characteristic differences including damping, resonance frequencies, etc. Due to multiple variables that are relevant …

Interaction Of A Shock Tube Exhaust Flow With A Non-Pre-Mixed Flame, Graham Doig, Zebulan Johnson, Rachel Mann

Aerospace Engineering

No abstract provided.

Low-Pressure Testing: Pressure Regulating Valves, Charles M. Burt, Kyle Feist

BioResource and Agricultural Engineering

ITRC tested performance characteristics of pressure regulating valves from a variety of manufacturers. The purpose of the testing was to evaluate the ability of different models of valves to regulate the pressure in a low-pressure system. The testing concentrated on three specific valve performance characteristics: minimal variance from the target downstream pressure caused by changes in flow rate or inlet pressure; minimal hysteresis in outlet pressures; minimal pressure loss (at low inlet pressures) across the valve.

Low-Pressure Testing: Microirrigation Emitters, Charles M. Burt, Kyle Feist

BioResource and Agricultural Engineering

ITRC tested 28 different pressure-compensating (PC) models of microirrigation emitting devices from a total of nine manufacturers in order to compare independent laboratory testing with manufacturer specifications. It is the intention of this report to investigate the ability of currently marketed products to operate in a truly low pressure irrigation system where energy inputs, in the form of pump discharge requirements, can be minimized.

Finite Element Models Of The Knee & Hip Joints: Using Opensim To Predict Muscle Forces, Kevin S. Jones, Spencer D. Wangerin, Jeffrey D. Pyle, Stephen M. Klisch, Scott J. Hazelwood

STAR Program Research Presentations

Quantitative data of stresses and strains in the cartilage of the knee and hip joints are required to design prostheses and can be used to give accurate advice to patients with cartilage damage as to which activities should be avoided. Instrumented hip implants can only give the overall resultant force in the joint, not the stresses and strains throughout the cartilage. Finite Element (FE) models of the Knee and Hip are being constructed in order to obtain the stresses and strains in articular (of the joint) cartilage. Muscle forces and joint contact forces are required as inputs to these FE …

Tools And Methods To Optimize The Analysis Of Telescopic Performance Metrics On Sofia, Steven R. Wilson, Holger Jakob, Stefan Teufel, Zaheer Ali, Jeffrey Van Cleve, Brian Eney, Greg Perryman

STAR Program Research Presentations

SOFIA is an infrared observatory mounted on a modified 747 engineered to do infrared astronomy at 45000 feet. The telescope equipment contains a number of sensors and stabilizers that allow the telescope to capture images while mounted in a moving plane. We have developed methods to analyze the performance of the telescope assembly that will help improve the stabilization and image capturing performance of the observatory. Here we present reusable methods to analyze telescope performance data that will enable improvements in the quality of the scientific data that is produced by the SOFIA. This poster focuses on the multi-flight performance …

Feedback Stabilization At Spear3, Daniel Kelley, Jeff Corbett

STAR Program Research Presentations

The SPEAR3 synchrotron lightsource at SLAC relies on a sophisticated radio frequency (RF) timing system to maintain current – electrons – in the storage ring. One problem SPEAR3 operators have dealt with is the thermal expansion of one of the cables supporting this RF timing system. As the cable expands and contracts with the diurnal rise and fall of the sun, the phase of the RF in the cable shifts. This shifting phase affects the timing accuracy of electron injections into the storage ring.

A common feedback control algorithm PID (Proportional Integral Derivative) has countless applications in engineering. PID feedback …

Extending The Shelf Life Of Solid Rocket Motors Through Mechanical Activation Of, Emilio J. Cantu, Hope Klukovich, Timothy Haddad

STAR Program Research Presentations

A great deal of interest has been given to extending the life of our fleet of solid rocket motors. Once poured, these motors are essentially stored, unused, and are therefore subject to various environmental conditions. Cycling between high and low temperatures causes thermal expansion and contraction of motor materials. This will eventually lead to cracks forming and propagating in the rocket motor, rendering it unreliable and thus must be re-poured at great expense. A common binder material used in these motors is hydroxy-terminated polybutadiene (HTPB), which when cured with a diisocyanate, creates the solid matrix to house the energetic materials …

Juxtaposing Nasa’S Aeronet Aod With Carb Pm Data Over The San Joaquin Valley To Facilitate Multi-Angle Imaging Spectroradiometer (Misr) Pm Pollution Research, John Kanemoto

STAR Program Research Presentations

Airborne particulate matter (PM) has been shown to increase the risk for asthma, chronic bronchitis, cardiopulmonary complications, and respiratory cell membrane damage/infection/leakage. PM levels are currently analyzed from two perspectives: stationary land-based monitoring (LBM) sites and total Aerosol Optical Depth (AOD) atmospheric column measurements. Both perspectives often leave miles of space between measuring locations and will have a continually increasing cost from introducing/maintaining sites. The Multi-angle Imaging SpectroRadiometer (MISR) satellite team hopes to begin investigating/archiving PM levels comprehensively via inputting MISR AOD measurements into a function/model which predicts the amount of ground level PM.

In the future, multivariable spatial correlations …

Creating Exact Bezier Representations Of Cst Shapes, David D. Marshall

Aerospace Engineering

The paper presents a method of expressing CST shapes pioneered by Kulfan into standard Bezier curves and surfaces. Out of the seven standard shape classes identified by Kulfan as representable using CST curves, four of them, including airfoils, can be represented as Bezier curves exactly. For the other three, a convergent series expansion proves insufficient to achieve any practical accuracy, however these three classes are not the most commonly used of the CST classes. With the ability to express most common CST curves and surfaces as generic Bezier curves and surfaces, CST shapes can be used in CAD, solid modeling, …

Student Industry Cooperation For The Development Of Thermal System Design Teaching Laboratory Equipment, Steffen Peuker

Mechanical Engineering

In higher education, hands-on undergraduate education using state-of-the-art laboratory equipment is important to meet the quality standards expected in the engineering profession. However, the development of modern engineering laboratories is not only time consuming, but also budget constraints can hamper the development of needed laboratories for instructional purposes as Bidana and Billo state: "Development of state-of-the-art engineering laboratories is becoming an increasing problem in the University environment. Due to the greater variety and increased complexity of much state-of-the-art hardware and software, the cost and cycle time for development and startup of a modern engineering laboratory can be excessive. This, together …

Incorporating Active Learning Into A Thermal System Publications Lecture, Jennifer M. Peuker, Steffen Peuker

Mechanical Engineering

Many mechanical engineering departments offer a thermal system design (or similar) course for senior students. Some courses have a laboratory component, but many are a lecture only format. This paper demonstrates how active learning—through virtual labs, a semester long project, and in-class assignments—was incorporated into the lecture portion of a thermal system design course to enhance learning and provide the students a laboratory experience without a physical laboratory. These active learning ideas can also supplement the learning during lecture for those courses which have a designated laboratory time. Anecdotal evidence of the activities indicates that students were engaged and enjoyed …