3,275 research outputs found
Development of PAN (personal area network) for Mobile Robot Using Bluetooth Transceiver
In recent years, wireless applications using radio frequency (RF) have been rapidly evolving in personal computing and communications devices. Bluetooth technology was created to replace the cables used on mobile devices. Bluetooth is an open specification and encompasses a simple low-cost, low power solution for integration into devices. This research work aim was to provide a PAN (personal area network) for computer based mobile robot that supports real-time control of four mobile robots from a host mobile robot. With ad hoc topology, mobile robots may request and establish a connection when it is within the range or terminated the connection when it leaves the area. A system that contains both hardware and software is designed to enable the robots to participate in multi-agent robotics system (MARS). Computer based mobile robot provide operating system that enabled development of wireless connection via IP address
Design of small CRPA arrays with circular microstrip loops for electromagnetically coupled feed
This paper proposes a design of small controlled reception pattern antenna (CRPA) arrays using circular microstrip loops with frequencyinsensitive characteristics. The proposed array consists of seven identical upper and lower circular loops that are electromagnetically coupled, which results in a frequency-insensitive behavior. To demonstrate the feasibility of the proposed feeding mechanism, the proposed array is fabricated, and its antenna characteristics are measured in a full-anechoic chamber. The operating principle of the proposed feeding mechanism is then interpreted using an equivalent circuit model, and the effectiveness of the circular loop shape is demonstrated by calculating near electromagnetic fields in proximity to the radiator. The results confirm that the proposed feeding mechanism is suitable to have frequency- insensitive behavior and induces strong electric and magnetic field strengths for higher radiation gain in extremely small antenna arrays
Thermophysical and elastic properties of Cu50Zr50 and (Cu50Zr50)95Al5 bulk-metallic-glass-forming alloys
By employing a containerless high-temperature high-vacuum electrostatic levitation technique, the thermophysical properties, including the ratio between the specific heat capacity and the hemispherical total emissivity, the specific volume, and the viscosity, of Cu50Zr50 and (Cu50Zr50)95Al5 bulk-metallic-glass (BMG)-forming liquids have been measured. Compared with Cu50Zr50, the improved glass-forming ability of (Cu50Zr50)95Al5 can be attributed to its dense liquid structure and its high value of viscosity. Additionally, the relationship between the viscosity of various BMG forming liquids at the melting temperature and the elastic properties of the corresponding glasses at room temperature will be compared
Dynamics of axial separation in long rotating drums
We propose a continuum description for the axial separation of granular
materials in a long rotating drum. The model, operating with two local
variables, concentration difference and the dynamic angle of repose, describes
both initial transient traveling wave dynamics and long-term segregation of the
binary mixture. Segregation proceeds through ultra-slow logarithmic coarsening.Comment: 4 pages, 3 Postscript figures; submitted to PR
Chemical Raman Enhancement of Organic Adsorbates on Metal Surfaces
Using a combination of first-principles theory and experiments, we provide a
quantitative explanation for chemical contributions to surface-enhanced Raman
spectroscopy for a well-studied organic molecule, benzene thiol, chemisorbed on
planar Au(111) surfaces. With density functional theory calculations of the
static Raman tensor, we demonstrate and quantify a strong mode-dependent
modification of benzene thiol Raman spectra by Au substrates. Raman active
modes with the largest enhancements result from stronger contributions from Au
to their electron-vibron coupling, as quantified through a deformation
potential, a well-defined property of each vibrational mode. A straightforward
and general analysis is introduced that allows extraction of chemical
enhancement from experiments for specific vibrational modes; measured values
are in excellent agreement with our calculations.Comment: 5 pages, 4 figures and Supplementary material included as ancillary
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On-Demand Power Source for Medical Electronic Implants: Acousto-Mechanical Vibrations from Human Vocal Folds
For use in vibration-driven power generation, we have quantitatively characterized the acousto-mechanical vibrations that propagate from the human vocal folds through the neck and head along the skeletal frames. We have used five MEMS accelerometers to characterize the acousto-mechanical vibrations present in various situations. The acousto-mechanical
vibrations excite vibration-driven energy harvesters at their resonance frequencies between 90-300 Hz and generate up to 0.15 mW/cm^3 on demand
Diamagnetically Levitated MEMS Accelerometers
We introduce the theory and a proof-of-concept design for MEMS-based, diamagnetically-levitated
accelerometers. The theory includes an equation for determining the diamagnetic force above a
checkerboard configuration of magnets. We demonstrate both electronic probing and a rapid MEMS-based
interferometer technique for position sensing of the proof mass. Through a proof-of-concept
design, we show electrostatic-measurement sensitivity achieving 34 μg at a 0.1 V sense signal and
interferometer-measurement sensitivity achieving 6 μg for in-plane vibrations at 5 Hz. We conclude by
outlining batch-fabrication steps to produce levitated accelerometers
Shared Risk Factors for Mood-, Eating-, and Weight-Related Health Outcomes
Objective: Given the overlap among depressive symptoms, disordered eating, and overweight, identifying shared risk factors for these conditions may inform public health interventions. This study aimed to examine cross-sectional and prospective relationships among these 3 conditions, and identify potential shared eating-related and psychosocial variable risk factors (i.e., body dissatisfaction, dieting, teasing experiences).
Method: A population-based sample (n = 1,902) self-reported depressive symptoms, disordered eating (binge eating, extreme weight control behaviors), weight status, and several putative risk factors (body satisfaction, dieting frequency, weight-related teasing) at 5-year intervals spanning early/middle adolescence, middle adolescence/early young adulthood, and early/middle young adulthood.
Results: There was moderate overlap among depressive symptoms, disordered eating, and overweight at each time point, and moderate stability in each condition over time. Body dissatisfaction and dieting were the most potent shared risk factors for later depressive symptoms, disordered eating, and overweight among males and females (ps \u3c .05).
Conclusions: Depressive symptoms, disordered eating, and overweight share several risk factors, including dieting and body dissatisfaction, which may be effective targets for interventions aiming to simultaneously prevent these 3 conditions
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