Engineering Commons^™

Friction Of Soft Elastomeric Surfaces With A Defect, Charles J. Rand, Alfred Crosby

Alfred Crosby

We consider a simple problem that provides insight into the building blocks of friction for topographically patternedsurfaces and fundamental understanding into the general friction of coatings. The problem focuses on the effect of a line defect, such as a pattern’s edge, on the lateral force of a sliding soft interface. The line defect presents a discontinuity in the stress at the sliding interface, changing the lateral stiffness and decreasing the sliding force. We relate the decrease in sliding shear force to the changes in lateral stiffness through relationships that account for contact splitting and lateral confinement effects.

Fate And Transport Of Pathogen Indicators From Pasturelands, Michelle L. Soupir

Michelle L. Soupir

The U.S. EPA has identified pathogen indicators as a leading cause of impairments in rivers and streams in the U.S. Elevated levels of bacteria in streams draining the agricultural watersheds cause concern because they indicate the potential presence of pathogenic organisms. Limited understanding of how bacteria survive in the environment and are released from fecal matter and transported along overland flow pathways results in high uncertainty in the design and selection of appropriate best management practices (BMPs) and in the bacterial fate and transport models used to identify sources of pathogens.

The overall goal of this study was to improve …

Laminar Flow In Mini-Fluidics Channels Assembly And Its Application In Zebra Fish Embryo Research, Radek Glaser

Radek Glaser

A Mini-Fluidics system was designed to facilitate the muscle growth of the Zebra Fish embryos. This experimental device is made of peristaltic pump, inflow/outflow manifolds, fluid storage tank, series of valves and flexible pipes and the main plate with six mini channels. These closed channels provide pathways for an extremely laminar flow. The Zebra Fish embryos are placed in the channels and exposed to the forces present in the fluid.

Environmental Sustainability Asessment In Iran’S Southpars Special Economic Energy Zone, Omidreza Saadatian

No abstract provided.

Agricultural Applications For Electromagnetic Exposure, H. Aliakbarian, A. Enayati, Hossein Ameri Mahabadi, M. Ashayer Soltani

Hossein Ameri Mahabadi

Despite the advances in bug controlling and antifreezing operations of agricultural products, the devastation of Sunne pests and freezing is still enormous. Traditional treatments such as chemical insecticides for bug controlling and covering to avoid freezing have not been sufficient. In the presented paper, new ideas of using electromagnetic treatment for anti-freezing operation, pre-harvest Sunne pest control, and Orchid flower control are introduced.

Athermal Resistance To Interface Motion In The Phase-Field Theory Of Microstructure Evolution, Valery I. Levitas, Dong Wook Lee

Valery I. Levitas

A method of introducing an athermal resistance to interface propagation for the Ginzburg-Landau (GL) approach to the first-order phase transformations (PTs) is developed. It consists of introducing oscillating fields of stresses (due to various defects or a Peierls barrier) or a jump in chemical energy. It removes some essential drawbacks in GL modeling: it arrests experimentally observed microstructures that otherwise converge to a single phase, and it reproduces rate-independent stress hysteresis. A similar approach can be applied for twinning, dislocations, and other PTs (e.g., electric and magnetic).

A Bubble-Powered Micro-Rotor: Conception, Manufacturing, Assembly And Characterization, Jonathan Kao, Xiaolin Wang, John Warren, Jie Xu, Daniel Attinger

Daniel Attinger

A steady fluid flow, called microstreaming, can be generated in the vicinity of a micro-bubble excited by ultrasound. In this paper, we use this phenomenon to assemble and power a microfabricated rotor at rotation speeds as high as 625 rpm. The extractible power is estimated to be of the order of a few femtowatts. A first series of experiments with uncontrolled rotor shapes is presented, demonstrating the possibility of this novel actuation scheme. A second series of experiments with 65 µm rotors micromanufactured in SU-8 resin is then presented. Variables controlling the rotation speed and rotor stability are investigated, such …

Burrowing In Marine Muds By Crack Propagation: Kinematics And Forces, Sanjay Raja Arwade, Kelly M. Dorgan, Peter A. Jumars

Sanjay Raja Arwade

The polychaete Nereis virens burrows through muddy sediments by exerting dorsoventral forces against the walls of its tongue-depressor-shaped burrow to extend an oblate hemispheroidal crack. Stress is concentrated at the crack tip, which extends when the stress intensity factor (KI) exceeds the critical stress intensity factor (KIc). Relevant forces were measured in gelatin, an analog for elastic muds, by photoelastic stress analysis, and were 0.015±0.001 N (mean ± s.d.; N=5). Measured elastic moduli (E) for gelatin and sediment were used in finite element models to convert the forces in gelatin to those required in muds to maintain the same body …

A Novel Method Of Detecting Missing Parallel/Multiple Bond-Wires In Microwave Transistors That Is Amenable To Integration With Automated Test Handlers, Chin-Leong Lim

Chin-Leong Lim

A method of detecting a missing parallel-connected bond-wires in packaged microwave transistors is described. Instead of the conventional way of testing the transistor in the amplifier configuration, the new method tests the device as an oscillator. Using the oscillation frequency as the screening criterion reduces test complexity and allows easy integration with existing automated test handlers

Trends In Uspto Office Actions, Ron D. Katznelson

Ron D. Katznelson

No abstract provided.

High-Speed Three-Dimensional Shape Measurement System Using A Modified Twoplus- One Phase-Shifting Algorithm, Song Zhang, Shing-Tung Yau

Song Zhang

This paper describes a high-resolution, real-time, three-dimensional shape measurement system using the modified two-plus-one phase-shifting algorithm. The data acquisition speed is as high as 60frames∕s with an image resolution of 640×480pixels per frame. Experiments demonstrated that the system was able to acquire the dynamic changing objects such as facial geometric shape changes when the subject is speaking, and the modified two-plus-one phase-shifting algorithm can further alleviate the error due to motion. Applications of this system include manufacturing, online inspection, medical imaging, compute vision, and computer graphics.

Crumpled Surface Structures, Douglas P. Holmes, Michal Ursiny, Alfred Crosby

Alfred Crosby

We present a scalable patterning method based on surface plate buckling, or crumpling, to generate a variety of topographies that can dynamically change shape and aspect ratio in response to stimuli.

The Dangers Of Automobile Travel: A Reconsideration, Roger Roots

Roger Roots

America's reliance on automobile transportation has attracted the scorn of academics for decades. Automobiles, it is said, are dangerous to life and limb, environmentally unfriendly, and wasteful of space and resources. Moreover, say the critics, automobiles produce inefficient individualistic social behavior that balkanizes com munities and shatters the otherwise cohesive nature of American life. This article examines the costs and benefits of U.S. automobile travel from a historic perspective. First, it compares the safety of automobile travel with the horse and steam-powered travel that preceded it. It then briefly addresses the changes wrought by American automobiles in terms of their …

Conference Report. Sakawa 2007, Fathi Habashi

Fathi Habashi

First International Symposium on Aqua Science, Water Resource, and Innovation Development of Countryside. November 26-30, 2007, Sakawa, Kochi Prefecture, Japan

The Effect Of A Knee Support On The Biomechanical Response Of The Low Back, Yu Shu, Zongliang Jiang, Xu Xu, Gary A. Mirka

Gary A. Mirka

Stooping and squatting postures are seen in a number of industries (e.g., agriculture, construction) where workers must work near ground level for extended periods of time. The focus of the current research was to evaluate a knee support device designed to reduce the biomechanical loading of these postures. Ten participants performed a series of sudden loading tasks while in a semisquat posture under two conditions of knee support (no support and fully supported) and two conditions of torso flexion (45 and 60°). A weight was released into the hands of the participants who then came to steady state while maintaining …

Posterminaries: More Or Less Modern, Alexander H. King

Alexander H. King

It is yet another sign that I am aging. More and more often when young researchers hand me a written report of their research, I find myself criticizing their introductory section: “You need to start your literature survey with the original papers on this topic. Go and read…” followed by a citation to some classic of the learned literature.

Delay And Energy Tradeoff In Multi-State Wireless Sensor Networks, W. L. Leow, H. Pishro-Nik, Daiheng Ni

Daiheng Ni

This paper discusses a first attempt to investigate, using analytic means, the transmission delay and energy char- acteristics of a multi-state wireless sensor network. For such a network with n nodes, where each node can be active, resting or sleeping, a model that describes the transition of a node from one state to another and the probability associated with each state is proposed. Asymptotic analyses of transmission delay and energy are presented. We report the presence of a threshold for the arrival rate of data packets that decides which energy component dominates. The transmission delay-energy tradeoff is presented for the …

Dynamic Water Adsorption Characteristics Of Distillers Dried Grains With Solubles (Ddgs), V. Ganesan, Kurt A. Rosentrater, Kasiviswanathan Muthukumarappan

Kurt A. Rosentrater

Distillers dried grains with solubles (DDGS) is one of the coproducts obtained from dry-grind ethanol manufacturing. As the ethanol industry is growing exponentially, the production of DDGS has been significantly increasing as well. To optimize the use of DDGS, it has to be economically transported from one part of the country to other parts, and stored efficiently. But DDGS has some flow issues, which often makes storage and transportation very problematic. So the objective of this study was to investigate the dynamic water adsorption characteristics of DDGS with four soluble levels at four temperatures and four relative humidities. Three mathematical …

0.5w High Linearity Power Amplifier For Broadband Wireless (3.3 ~ 3.9 Ghz), Chin-Leong Lim

Chin-Leong Lim

This paper presents a 0.5 Watt amplifier that operates over the 3.3 ~ 3.9 GHz range. The target applications are pre-driver in base-stations and power amplifier in subscriber units. The design marries good Third Order Output Intercept Point (OIP3) and exceptional Power Added Efficiency (PAE) at IdB gain compression point (PldB). The performances are: -G = 11.8 dB, IRL & ORL < -8 dB, PldB = 28.5 dBm and OIP3 = 42.6 dBm. The superior performance is achieved through the use of Avago Technologies' proprietary 0.25um GaAs Enhancement mode pHEMT process. The device requires simple matching components to achieve wide bandwidth because of the built-in input pre-match. From the reliability standpoint, pHEMT devices are eminently suited to PA use -the drain to source resistance (RDSon) will inherently rise to counteract the thermal runaway that blights bipolar and HBT PAs. The internal bias circuit is temperature compensated and can be adjusted for either class A or class AB operation. The device is housed inside a standard 16 pin LPCC 3X3 package.

Ocena Wpływu Planowanego Zakładu Termicznego Przekształcania Odpadów Komunalnych Na Jakość Powietrza W Krakowie, Robert Oleniacz, Maria Pilch

Robert Oleniacz

The work presents air quality impact assessment for the planned Municipal Solid Waste Incineration (MSWI) plant in Krakow with a established capacity of 255000 tons per year. The evaluation is based on assumption that air pollutant emissions from the incinerator will be at the highest allowed level resulting from emission limit values for waste incineration plants with operation time each of two planned lines 7500 hours per year. Calculation results for the one of the considered localization of the MSWI plant in Krakow (district of Nowa Huta) support the thesis that building the incineration plant of this size will not …

Repetitive Impact Response Of A Beam Structure Subjected To Harmonic Base Excitation, Elizabeth K. Ervin, Jonathan A. Wickert

Jonathan A. Wickert

This paper investigates the forced response dynamics of a clamped–clamped beam to which a rigid body is attached, and in the presence of periodic or non-periodic impacts between the body and a comparatively compliant base structure. The assembly is subjected to base excitation at specified frequency and acceleration, and the potentially complex responses that occur are examined analytically. The two sets of natural frequencies and vibration modes of the beam-rigid body structure (in its in-contact state, and in its not-in-contact state), are used to treat the forced response problem through a series of algebraic mappings among those states. A modal …

Acoustic Excitation Of Superharmonic Capillary Waves On A Meniscus In A Planar Microgeometry, Jie Xu, Daniel Attinger

Daniel Attinger

The effects of ultrasound on the dynamics of an air-water meniscus in a planar microgeometry are investigated experimentally. The sonicated meniscus exhibits harmonic traveling waves or standing waves, the latter corresponding to a higher ultrasound level. Standing capillary waves with subharmonic and superharmonic frequencies are also observed, and are explained in the framework of parametric resonance theory, using the Mathieu equation.

Electric Power: Cyber And Electromagnetic Security Issues, George H. Baker

George H Baker

Electric power is essential to the functioning of U.S. society. The electric power system increasingly operates at or near its reliability limits. The geographic scale of the tightly coupled networks involved makes the system susceptible to large-scale outages. More frequent natural and accidental failures portend possible catastrophes from intentional disruption. Deregulation has been a major factor to the lack of investment in system upgrades. Techniques to prevent attacks and reduce vulnerabilities are available and affordable.

Growth-Temperature Optimization For Low Carrier-Density In0.75Ga0.25As-Based High Electron Mobility Transistors On Inp, Paul J. Simmonds, H. E. Beere, D. A. Ritchie, S. N. Holmes

Paul J. Simmonds

Two-dimensional electron gases (2DEGs) were formed in undoped In_0.75Al_0.25As / In_0.75Ga_0.25As / In_0.75Al_0.25As quantum wells. The optimal growth temperature for this structure is 410°C, with peak 2DEG electron mobility and density values of μ = 221000 cm²/V s and n = 1.36 × 10¹¹ cm⁻² at 1.5 K. This electron mobility is equal to the highest previously published for these undoped structures but with a factor of 2 reduction in n. This has been achieved through the use of a significantly thinner InAlAs …

"Conversational" Dialogues In Direct-Manipulation Interfaces, David G. Novick

David G. Novick

This paper reports ongoing research in extending direct-manipulation interfaces by incorporating, via the direct-manipulation modality itself, interaction techniques that add kinds of language features associated with spoken conversation. The paper proposes means of implementing ways for a user of a direct-manipulation system to define new kinds of relations among objects in the interface.

Users And Uses Of Synchronous Business Communications Software, David G. Novick, Eleanor Wynn

David G. Novick

To help designers and authors understand users' intentions and work practices for synchronous business communications in a systematic way, we used ethnographic and task-analytic techniques to collect, analyze and classify evidence of the activities of potential users as they conducted their work lives. The interactions we observed among our users took place through a variety of modalities. We found eight categories of tasks for the collaborative or interactive work in which our subjects engaged. Based on these data, we were able to classify roles of potential users of synchronous business communications software into a set of "archetypes" that characterize their …

Hands-Free Documentation, Karen Ward, David G. Novick

David G. Novick

In this paper, we introduce an analysis of the requirements and design choices for hands-free documentation. Hands-busy tasks such as cooking or car repair may require substantial interruption of the task: moving the pan off the burner and wiping hands, or crawling out from underneath the car. We review the need for hands-free documentation and explore the role of task in the use of documentation. Our central analysis examines the roles and characteristics of input and output modalities of hands-free documentation. In particular, we review the use of speech as an input modality, and then visual means and speech as …

An Interaction Initiative Model For Documentation, David G. Novick, Karen Ward

David G. Novick

In this paper we propose a model of creation and use of documentation based on the concept of mixed-initiative interaction. In our model, successful single-initiative interaction is characterized by grounding of contributions, and successful mixed-initiative interaction is characterized by both grounding and agreement. Just as in spoken conversation, achievement of actual agreement depends on the intentions of both parties; agreement is achieved when the reader follows the documentation’s instructions. In fact, readers are not obligated to—and often do not—act according to the author’s intentions. By making these dynamics explicit, the model can aid authors in developing effective documentation. The paper …

Assessing Effectiveness Of Personality Style In Documentation, Kenneth Sayles, David G. Novick

David G. Novick

This paper extends previous work by other researchers that indicated that users of computers preferred a computer with a personality that was similar to theirs. We conducted a similar experiment, but looking beyond preference to see if the personality of documentation would make a difference in the user’s performance. Our data suggest did not indicate that personality match affects performance; and if such a relationship exists it is likely to be weak. We discuss the related research, describe our methodology, present our results, and describe their implications and limitations.

Understanding Prediction Systems For Hla-Binding Peptides And T-Cell Epitope Identification, L. You, P. Zhang, M. Boden, V. Brusic

Ping Zhang

Peptide binding to HLA molecules is a critical step in induction and regulation of T-cell mediated immune responses. Because of combinatorial complexity of immune responses, systematic studies require combination of computational methods and experimentation. Most of available computational predictions are based on discriminating binders from non-binders based on use of suitable prediction thresholds. We compared four state-of-the-art binding affinity prediction models and found that nonlinear models show better performance than linear models. A comprehensive analysis of HLA binders (A*0101, A*0201, A*0301, A*1101, A*2402, B*0702, B*0801 and B*1501) showed that non-linear predictors predict peptide binding affinity with high accuracy. The analysis …