6,332 research outputs found
The Interface of Work to Family Conflict and Racioethnic Identification: An Analysis of Hispanic Business Professionals
This article examines work to family conflict for Hispanic Business Professionals with varied levels of Hispanic identity. Based on this study of 971 Hispanics from across the United States, results show that level of Hispanic identity moderates the relationship between work to family conflict and job satisfaction. The authors posit that identification with a culture of collectivism may attenuate the negative impact of work to family conflict on job satisfaction, enabling Hispanic professionals to view work as a way of supporting the family and contributing to the greater good of the groups to which they belong
Sensor tip for a robotic gripper and method of manufacture
A sensor tip (10) for use in a robotic hand has a three-dimensional compliant elastomeric body (12) with an outer boundary (22) having a circular base (24) and a convex surface (26) extending therefrom. Four strain transducers (14, 16, 18, and 20) produce electrical signals indicative of the strain at various positions near the boundary of the elastomeric body (12) resulting from forces exerted upon the sensor tip (10) by an object which the robotic hand is manipulating. The transducers (14, 16, 18, and 20) are positioned about the convex surface (26) so as to produce signals that may be decoupled to determine the normal and tangential forces and the applied torque. A buffer amplifier circuit (34), one for each of the transducers (14, 16, 18, and 20), receives the signals and provides quasi-steady state force information. The circuit (34) connects the respective transducer (40) in a feedback loop around an amplifier (36) and has desirable attributes for static charge buffering. The sensor tip (10) is calibrated to determine proportionality constants for the decoupling algorithm for use of a force delivering system (60), which uses voice coils (74) to apply a force that is linearly related to the current introduced to each of the coils (74). A method of manufacture of the sensor tip (10) results in improved bonding between the transducers (14, 16, 18, and 20) and the elastomeric body (12) for better performance and longer life of the sensor tip (10)
Microsofts Monopoly: Anti-Competitive Behavior, Predatory Tactics, And The Failure Of Governmental Will
Thirty years ago, Microsoft Corp. was founded by Bill Gates and Paul Allen.  To understand how the company has gained competitive advantage we examine how the company used unfair, anti-competitive, and predatory approaches in their business.  We discuss how we have come to the belief that the government settlement in United States and State of New York, et al., v. Microsoft Corporation imposing restrictions on Microsoft’s behavior and monitoring its actions for compliance is not enough to keep it from abusing its monopolistic power and does too little to prevent it from dominating the software and operating system industry today
Drawing and Twisting of Graphene Fibers
The aim of this project was to develop a more automated process for drawing and twisting of graphene fibers than was currently in place. This was implemented by having two chemical baths with variable speed rollers at either end, and intermediate roller to spool fiber between stages, and a twisting cylinder with integral spool to twist the fiber as it is collected. The goal was to have this first iteration deliver a working prototype, however due to manufacturing delays and timing constraints, that will be missed. A second follow-on project would be able to continue the work presented here and fulfil the stated aims of the project. The bulk of the structure is fabricated from PVC pieces waterjet cut from a large sheet. This allowed for quick manufacture of most pieces in the design. From there, some secondary machining was done to add mounting and fastening locations. PVC pieces were attached to one another primarily through the use of #8-32 screws with washers and a brass threaded insert. Due to PVC being a soft material, tapping threads into it directly was avoided. The baths were sealed mostly with an automotive gasket compound to permanently seal one half, while one wall was sealed with a silicon gasket laser cut from a sheet. This makes the bath wall removable for maintenance. Two baths were made to allow multiple stages of drawing or one coagulation stage immediately followed by a drawing stage. From the drawing, the fiber advances to the auxiliary roller. The range of speeds required to get desired properties at all stages did not permit the fiber to go from coagulation to drawing to twisting in one process, therefore following the drawing bath, it is wound on to the auxiliary roller. After the drawing process is finished, the fiber can be pulled from the auxiliary roller into the twisting mechanism, running at a lower speed so as to give the requisite number of turns per length of fiber to yield the optimal fiber twist angle. The twisting mechanism is a PVC cylinder supported on horizontal rods and driven by a motor mounted beneath the cylinder and connected via a plastic belt. The cylinder, motor, and support rods are encased in a box with one face open to allow the fiber into the cylinder. Inside the cylinder is a spinning rod mounted across the diameter that collects the fiber as it is twisted. The aim of the project called for a quick-release mechanism so that the rod can be removed quickly for storage of the fiber or other testing steps. All of the motion is powered by small 5V DC motors that go through a 20:1 worm gear reduction. This increases the torque while decreasing the speed from roughly 10,000 RPM to more useful ranges. The motors are powered through a NPN power transistor with the logic being controlled by an Arduino Nano that takes in an analog voltage and converts it to a PWM waveform to control the motor duty cycle. In total, the project came in under budget, using 84.01% of the 925.38 estimate first presented
Quantitative tunneling spectroscopy of nanocrystals
The proposed goals of this collaborative work were to systematically characterize the electronic structure and dynamics of 3-dimensional metal and semiconducting nanocrystals using scanning tunneling microscopy/spectroscopy (STM/STS) and ballistic electron emission spectroscopy (BEES). This report describes progress in the spectroscopic work and in the development of methods for creating and characterizing gold nanocrystals. During the grant period, substantial effort also was devoted to the development of epitaxial graphene (EG), a very promising materials system with outstanding potential for nanometer-scale ballistic and coherent devices ("graphene"Â refers to one atomic layer of graphitic, sp2 -bonded carbon atoms [or more loosely, few layers]). Funding from this DOE grant was critical for the initial development of epitaxial graphene for nanoelectronic
Intelligent subsystem interface for modular hardware system
A single chip application specific integrated circuit (ASIC) which provides a flexible, modular interface between a subsystem and a standard system bus. The ASIC includes a microcontroller/microprocessor, a serial interface for connection to the bus, and a variety of communications interface devices available for coupling to the subsystem. A three-bus architecture, utilizing arbitration, provides connectivity within the ASIC and between the ASIC and the subsystem. The communication interface devices include UART (serial), parallel, analog, and external device interface utilizing bus connections paired with device select signals. A low power (sleep) mode is provided as is a processor disable option
Mortality of Cranes (Gruidae) Associated with Powerlines over a Major Roost on the Platte River, Nebraska
Two 69-kilovolt powerlines spanning the Platte River in south central Nebraska are suspected to cause substantial mortality to sandhill cranes (Grus canadensis) and pose a threat to endangered whooping cranes (G. americana) that roost overnight on the river during spring and fall migrations. Most studies of crane collisions with powerlines in the region have focused on counts of carcasses away from night roosts on the river and none have accounted for potential biases in detecting carcasses. We found 61 carcasses of sandhill cranes below over-river segments of the two powerlines during 4 March to 7 April 2006 and 90 such carcasses between 5 March and 13 April 2007. In 2007 we estimated the number of carcasses undetected in our surveys due to removal by scavengers, loss to downstream flow, and observer oversight. We estimated between 165 and 219 sandhill cranes were killed by the two powerlines during spring 2007. These cnlculations exclude mortalities from individuals injured by powerline collisions and dying elsewhere, as well as those killed before or after our 5 March to 13 April survey period. We detected no evidence of mortality for whooping cranes during our surveys. Our results corroborate anecdotal evidence of signficant sandhill crane mortality each spring due to collisions with above-ground powerlines at this major night roost. Collisions by sandhill cranes will continue and collisions by Whooping cranes seem likely unless an effective means of averting birds from powerlines is implemented at this site
Thermal performance of two heat exchangers for thermoelectric generators
Thermal performance of heat exchanger is important for potential application in integrated solar cell/module and
thermoelectric generator (TEG) system. Usually, thermal performance of a heat exchanger for TEGs is analysed
by using a 1D heat conduction theory which ignores the detailed phenomena associated with thermo-hydraulics.
In this paper, thermal and mass transports in two different exchangers are simulated by means of a steady-state,
3D turbulent flow k -e model with a heat conduction module under various flow rates. In order to simulate an
actual working situation of the heat exchangers, hot block with an electric heater is included in the model. TEG
model is simplified by using a 1D heat conduction theory, so its thermal performance is equivalent to a real TEG.
Natural convection effect on the outside surfaces of the computational model is considered. Computational
models and methods used are validated under transient thermal and electrical experimental conditions of a TEG.
It is turned out that the two heat exchangers designed have a better thermal performance compared with an
existing heat exchanger for TEGs, and more importantly, the fin heat exchanger is more compact and has nearly
half temperature rise compared with the tube heat exchanger
Black Holes Radiate Mainly on the Brane
We examine the evaporation of a small black hole on a brane in a world with
large extra dimensions. Since the masses of many Kaluza-Klein modes are much
smaller than the Hawking temperature of the black hole, it has been claimed
that most of the energy is radiated into these modes. We show that this is
incorrect. Most of the energy goes into the modes on the brane. This raises the
possibility of observing Hawking radiation in future high energy colliders if
there are large extra dimensions.Comment: 11 page
XO-2b: a hot Jupiter with a variable host star that potentially affects its measured transit depth
The transiting hot Jupiter XO-2b is an ideal target for multi-object
photometry and spectroscopy as it has a relatively bright (-mag = 11.25) K0V
host star (XO-2N) and a large planet-to-star contrast ratio
(R/R). It also has a nearby (31.21") binary stellar
companion (XO-2S) of nearly the same brightness (-mag = 11.20) and spectral
type (G9V), allowing for the characterization and removal of shared systematic
errors (e.g., airmass brightness variations). We have therefore conducted a
multiyear (2012--2015) study of XO-2b with the University of Arizona's 61"
(1.55~m) Kuiper Telescope and Mont4k CCD in the Bessel U and Harris B
photometric passbands to measure its Rayleigh scattering slope to place upper
limits on the pressure-dependent radius at, e.g., 10~bar. Such measurements are
needed to constrain its derived molecular abundances from primary transit
observations. We have also been monitoring XO-2N since the 2013--2014 winter
season with Tennessee State University's Celestron-14 (0.36~m) automated
imaging telescope to investigate stellar variability, which could affect
XO-2b's transit depth. Our observations indicate that XO-2N is variable,
potentially due to {cool star} spots, {with a peak-to-peak amplitude of ~R-mag and a period of ~days for the 2013--2014
observing season and a peak-to-peak amplitude of ~R-mag and
~day period for the 2014--2015 observing season. Because of}
the likely influence of XO-2N's variability on the derivation of XO-2b's
transit depth, we cannot bin multiple nights of data to decrease our
uncertainties, preventing us from constraining its gas abundances. This study
demonstrates that long-term monitoring programs of exoplanet host stars are
crucial for understanding host star variability.Comment: published in ApJ, 9 pages, 11 figures, 3 tables; updated figures with
more ground-based monitoring, added more citations to previous work
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