399 research outputs found
Piezoelectric power scavenging of mechanical vibration energy
The process of acquiring the energy surrounding a system and converting it into usable electrical energy is termed power harvesting. With piezoceramic materials, it is possible to harvest power from vibrating structures. It has been proven that micro-to milliwatts of power can be generated from vibrating systems. The project targets the
transformation of mechanical vibration into electrical energy using piezoelectric material. In some mining applications, eg water jet drilling; large high frequency
vibrations may be present. If successfully harvested, this energy could be used to eliminate batteries in wireless sensors. This article presents a model of a piezoelectric
transducer, a mechanical vibration spectrum, the simulation of the model, prototype of the power scavenging circuit, experimental results and its future perspectives
Development of Vibrating Disc Piezoelectric Gyroscope
The paper presents an indigenously developed vibrating disc piezoelectric gyroscope, in which both excitation and detection have been done through piezoelectric, using PZT-5H material. The gyroscope has been driven to resonant state by direct piezoelectric effect, using 20 V ac signal at 93 kHz, and the output has been detected by the reverse piezoelectric effect.The performance of this gyroscope has been tested with 3 microprocessor-controlled turntable, and the output of the gyroscope has been found" to be linearly proportional to the rotationspeed within a range ± 150 °/s. The sensitivity of the gyroscope is about 0.5 mV/°/s, which is comparable to that of other gyroscopes of similar categor
Peristaltic transport of a two-layered fluid in a catheterized tube
The flow of a two-layered Newtonian fluid induced by peristaltic waves in a catheterized tube has been investigated. The expressions for the flow characteristics- the flow rate, the pressure drop and the friction forces at the tube and catheter wall are derived. It is found that the pressure drop increases with the flow rate but decreases with the increasing peripheral layer thickness and a linear relationship between pressure and flow exists. The pressure drop increases with the catheter size (radius) and assumes a high asymptotic magnitude at the catheter size more that the fifty percent of the tube size. The friction forces at the tube and catheter wall posses characteristics similar to that of the pressure drop with respect to any parameter. However, friction force at catheter wall assumes much smaller magnitude than the corresponding value at the tube wall
Piezoelectric power scavenging of mechanical vibration energy
The process of acquiring the energy surrounding a system and converting it into usable electrical energy is termed power harvesting. With piezoceramic materials, it is possible to harvest power from vibrating structures. It has been proven that micro-to milliwatts of power can be generated from vibrating systems. The project targets the
transformation of mechanical vibration into electrical energy using piezoelectric material. In some mining applications, eg water jet drilling; large high frequency
vibrations may be present. If successfully harvested, this energy could be used to eliminate batteries in wireless sensors. This article presents a model of a piezoelectric
transducer, a mechanical vibration spectrum, the simulation of the model, prototype of the power scavenging circuit, experimental results and its future perspectives
Thermodynamic studies of the two dimensional Falicov-Kimball model on a triangular lattice
Thermodynamic properties of the spinless Falicov-Kimball model are studied on
a triangular lattice using numerical diagonalization technique with Monte-Carlo
simulation algorithm. Discontinuous metal-insulator transition is observed at
finite temperature. Unlike the case of square lattice, here we observe that the
finite temperature effect is not able to smear out the discontinuous
metal-insulator transition seen in the ground state. Calculation of specific
heat (C_v) shows single and double peak structures for different values of
parameters like on-site correlation strength (U), f-electron energy (E_f) and
temperature.Comment: 6 pages, 7 figure
Modelling and Prediction of Soil Organic Carbon using Digital Soil Mapping in the Thar Desert Region of India
Not AvailableIn the present study, the distribution of soil organic carbon (SOC) was investigated using digital soil
mapping for an area of ~29 lakhs ha in Bikaner district, Rajasthan, India. To achieve this goal, 187 soil
profiles were used for SOC estimation by Quantile regression forest (QRF) model technique. Landsat data,
terrain attributes and bioclimatic variables were used as environmental variables. 10-fold cross-validation
was used to evaluate model. Equal-area quadratic splines were fitted to soil profile datasets to estimate
SOC at six standard soil depths (0-5, 5-15, 15-30, 30-60, 60-100 and 100-200 cm). Results showed that the
mean SOC concentration was very low with values varied from 1.18 to 1.53 g kg-1 in different depths.
While predicting SOC at different depths, the model was able to capture low variability (R2 = 1–7%).
Overall, the Lin’s concordance correlation coefficient (CCC) values ranged from 0.01 to 0.18, indicating
poor agreement between the predicted and observed values. Root mean square error (RMSE) and mean
error (ME) were 0.97 and 0.16, respectively. The values of prediction interval coverage probability (PICP)
recorded 87.2–89.7% for SOC contents at different depths. The most important variables for predicting
SOC concentration variations were the annual range of temperature, latitude, Landsat 8 bands 2, 5 and 6.
Temperature-related variables and remote sensed data products are important for predicting SOC
concentrations in arid regions. We anticipate that this digital information of SOC will be useful for frequent
monitoring and assessment of carbon cycle in arid regions.Not Availabl
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Scale up of production in a bioreactor of a halotolerant protease from moderately halophilic Bacillus sp. isolated from soil
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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