151 research outputs found

    Spiral lead platen robotic end effector

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    A robotic end effector is disclosed which makes use of a rotating platen with spiral leads used to impact lateral motion to gripping fingers. Actuation is provided by the contact of rolling pins with the walls of the leads. The use of the disclosed method of actuation avoids jamming and provides excellent mechanical advantage while remaining light in weight and durable. The entire end effector is compact and easily adapted for attachment to robotic arms currently in use

    Double lead spiral platen parallel jaw end effector

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    The double lead spiral platen parallel jaw end effector is an extremely powerful, compact, and highly controllable end effector that represents a significant improvement in gripping force and efficiency over the LaRC Puma (LP) end effector. The spiral end effector is very simple in its design and has relatively few parts. The jaw openings are highly predictable and linear, making it an ideal candidate for remote control. The finger speed is within acceptable working limits and can be modified to meet the user needs; for instance, greater finger speed could be obtained by increasing the pitch of the spiral. The force relaxation is comparable to the other tested units. Optimization of the end effector design would involve a compromise of force and speed for a given application

    Lived experience of rural community college applied science engineering technology graduates, The

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    Includes bibliographical references.2015 Summer.Society is proliferated with devices that have been designed, developed, and constructed to enhance everyday life emphasizing the importance of the engineering profession. But the number of students pursuing the engineering technology field continues to decline. The purpose of this interpretive phenomenological study was to explore the lived experiences of graduates who navigated through and completed an Associate of Applied Science (AAS) degree in Engineering Technology from a rural community college and then transitioned into the engineering workforce. To explore this phenomenon, participants completed in-depth interviews. The structures that emerged from the interviews and described how the participants experienced their journey were Perception and Experiences of Engineering Technology, Captivation of Engineering Technology, Significant Influences and Relationships, Value of an Associate of Applied Science degree in Engineering Technology, and Transition to the Workforce. These structures interweaved to create the textural structural synthesis of transformation. As their transformations occurred graduates were able to refine the direction of their engineering educational journey giving way to the essence of this study the unexpected journey. The findings of this study can help faculty develop and implement strategies to gain and keep perspective students interested in engineering programs. The findings can also help academic advisers guide students seamlessly through their education to a career

    CETA truck and EVA restraint system

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    The Crew Equipment Translation Aid (CETA) experiment is an extravehicular activity (EVA) Space Transportation System (STS) based flight experiment which will explore various modes of transporting astronauts and light equipment for Space Station Freedom (SSF). The basic elements of CETA are: (1) two 25 foot long sections of monorail, which will be EVA assembled in the STS cargo bay to become a single 50 ft. rail called the track; (2) a wheeled baseplate called the truck which rolls along the track and can accept three cart concepts; and (3) the three carts which are designated manual, electric, and mechanical. The three carts serve as the astronaut restraint and locomotive interfaces with the track. The manual cart is powered by the astronaut grasping the track's handrail and pulling himself along. The electric cart is operated by an astronaut turning a generator which powers the electric motor and drives the cart. The mechanical cart is driven by a Bendix type transmission and is similar in concept to a man-propelled railroad cart. During launch and landing, the truck is attached to the deployable track by means of EVA removable restraint bolts and held in position by a system of retractable shims. These shims are positioned on the exterior of the rail for launch and landing and rotate out of the way for the duration of the experiment. The shims are held in position by strips of Velcro nap, which rub against the sides of the shim and exert a tailored force. The amount of force required to rotate the shims was a major EVA concern, along with operational repeatability and extreme temperature effects. The restraint system was tested in a thermal-vac and vibration environment and was shown to meet all of the initial design requirements. Using design inputs from the astronauts who will perform the EVA, CETA evolved through an iterative design process and represented a cooperative effort

    A Dirac Sea and thermodynamic equilibrium for the quantized three-wave interaction

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    The classical version of the three wave interaction models the creation and destruction of waves; the quantized version models the creation and destruction of particles. The quantum three wave interaction is described and the Bethe Ansatz for the eigenfunctions is given in closed form. The Bethe equations are derived in a rigorous fashion and are shown to have a thermodynamic limit. The Dirac sea of negative energy states is obtained as the infinite density limit. Finite particle/hole excitations are determined and the asymptotic relation of energy and momentum is obtained. The Yang-Yang functional for the relative free energy of finite density excitations is constructed and is shown to be convex and bounded below. The equations of thermal equilibrium are obtained

    Neglect, Physical and Sexual Abuse: A Look at Posttraumatic Stress Disorder in Children and Adolescents

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    This article focuses on Posttraumatic Stress Disorder that is largely overlooked in the counseling field and literature, specifically in children and adolescents. Etiology, treatment options, and the course in which the disorder manifests itself holds great importance in understanding the grave effects these traumatic events have on youth. This article is the beginning attempt to begin to understand how children exhibits symptoms of PTSD in order to work collaboratively with those involved in the child’s life before it develops into a chronic maladaptive state

    A Riemann-Hilbert Problem for an Energy Dependent Schr\"odinger Operator

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    \We consider an inverse scattering problem for Schr\"odinger operators with energy dependent potentials. The inverse problem is formulated as a Riemann-Hilbert problem on a Riemann surface. A vanishing lemma is proved for two distinct symmetry classes. As an application we prove global existence theorems for the two distinct systems of partial differential equations ut+(u2/2+w)x=0,wt±uxxx+(uw)x=0u_t+(u^2/2+w)_x=0, w_t\pm u_{xxx}+(uw)_x=0 for suitably restricted, complementary classes of initial data

    Qualitative and Quantitative Evaluation of Indirect Immuno-fluorescent H-2 Stain on Tissue Sections

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65483/1/j.1399-0039.1979.tb00826.x.pd

    Metrics and geodesics induced by order relations

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46255/1/209_2005_Article_BF01115107.pd

    Effects of Gravitational Microlensing on P-Cygni Profiles of Type Ia Supernovae

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    A brief description of the deformed spectra of microlensed SNe Ia is presented. We show that microlensing amplification can have significant effects on line profiles. The resonance-scattering code SYNOW is used to compute the intensity profile in the rest frame of the supernova. The observed (microlensed) spectral lines are predicted assuming a simple stellar-size deflector, and are compared to unlensed cases to show the effects microlensing by solar-size deflectors can have on spectral lines. We limit our work to spherically symmetric deflectors.Comment: 18 pages, 9 figures, references added, submitted to Ap
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