Cavity optomechanics with stoichiometric SiN films

We study high-stress SiN films for reaching the quantum regime with mesoscopic oscillators connected to a room-temperature thermal bath, for which there are stringent requirements on the oscillators' quality factors and frequencies. Our SiN films support mechanical modes with unprecedented products of mechanical quality factor $Q_m$ and frequency $\nu_m$ reaching $Q_{m} \nu_m \simeq2 \times 10^{13}$ Hz. The SiN membranes exhibit a low optical absorption characterized by Im$(n) \lesssim 10^{-5}$ at 935 nm, representing a 15 times reduction for SiN membranes. We have developed an apparatus to simultaneously cool the motion of multiple mechanical modes based on a short, high-finesse Fabry-Perot cavity and present initial cooling results along with future possibilities.Comment: 4 pages, 5 figure

Self-consistent treatment of the self-energy in nuclear matter

The influence of hole-hole propagation in addition to the conventional particle-particle propagation, on the energy per nucleon and the momentum distribution is investigated. The results are compared to the Brueckner-Hartree-Fock (BHF) calculations with a continuous choice and conventional choice for the single-particle spectrum. The Bethe-Goldstone equation has been solved using realistic $NN$ interactions. Also, the structure of nucleon self-energy in nuclear matter is evaluated. All the self-energies are calculated self-consistently. Starting from the BHF approximation without the usual angle-average approximation, the effects of hole-hole contributions and a self-consistent treatment within the framework of the Green function approach are investigated. Using the self-consistent self-energy, the hole and particle self-consistent spectral functions including the particle-particle and hole-hole ladder contributions in nuclear matter are calculated using realistic $NN$ interactions. We found that, the difference in binding energy between both results, i.e. BHF and self-consistent Green function, is not large. This explains why is the BHF ignored the 2h1p contribution.Comment: Preprint 20 pages including 15 figures and one tabl

Utilization of Agricultural Waste in Treating Water Pollutants

This study investigated the applicability of chemically (phosphoric acid) activated bagasse pith and date pits in the adsorption of water pollutants. The textural properties including porous parameters, monolayer equivalent surface area, total pore volumes, average pore radius, Methylene blue number and other physic-chemical characterization were investigated. The activated carbons were analyzed for moisture content, ash content. Ultimate analysis was done by using CHNS analyzer (Cairo University, Micro-analytical Center). To investigate the effect of phosphoric acid on the raw material, thermo gravimetric analysis (TGA) and differential thermo gravimetric (DTG) recordings were determined. The adsorption of heavy metals as pollutants, including Co, Sr, Cu, Cs, Pb, Cd, Ni, Fe, Zn, was studied in a batch experiments. Comparison of date pits activated carbon with commercial activated carbon was done, and the results indicated that using of prepared activated carbon for removal of Co, Sr, Cu, Cs, Pb, Cd, Ni,  Fe, Zn was  more effective than commercial activated carbon

Scalar FCNC and rare top decays in a two Higgs doublet model "for the top"

In the so called two Higgs doublet model for the top-quark (T2HDM), first suggested by Das and Kao, the top quark receives a special status, which endows it with a naturally large mass, and also potentially gives rise to large flavor changing neutral currents (FCNC) only in the up-quark sector. In this paper we calculate the branching ratio (BR) for the rare decays t->ch and h->tc (h is a neutral Higgs) in the T2HDM, at tree level and at 1-loop when it exceeds the tree-level. We compare our results to predictions from other versions of 2HDM's and find that the scalar FCNC in the T2HDM can play a significant role in these decays. In particular, the 1-loop mediated decays can be significantly enhanced in the T2HDM compared to the 2HDM of types I and II, in some instances reaching BR~10^-4 which is within the detectable level at the LHC.Comment: added two references. 15 pages, 14 figure

Energy and Momentum densities of cosmological models, with equation of state ρ=μ\rho=\mu, in general relativity and teleparallel gravity

We calculated the energy and momentum densities of stiff fluid solutions, using Einstein, Bergmann-Thomson and Landau-Lifshitz energy-momentum complexes, in both general relativity and teleparallel gravity. In our analysis we get different results comparing the aforementioned complexes with each other when calculated in the same gravitational theory, either this is in general relativity and teleparallel gravity. However, interestingly enough, each complex's value is the same either in general relativity or teleparallel gravity. Our results sustain that (i) general relativity or teleparallel gravity are equivalent theories (ii) different energy-momentum complexes do not provide the same energy and momentum densities neither in general relativity nor in teleparallel gravity. In the context of the theory of teleparallel gravity, the vector and axial-vector parts of the torsion are obtained. We show that the axial-vector torsion vanishes for the space-time under study.Comment: 15 pages, no figures, Minor typos corrected; version to appear in International Journal of Theoretical Physic

Electrochemical Performance of Grids of Lead-acid Batteries made from Pb-0.8%Ca-1.1%Sn Alloys Containing Cu, As and Sb Impurities in the presence of phosphoric acid

Electrochemical performance of grids of lead-acid Batteries manufactured from Pb-0.8%Ca-1.1%Sn alloys containing Cu, As and Sb impurities at 0.1 wt% level were studied in 4.0 M H2SO4 without and with 0.4 M H3PO4. The presence of impurities in the alloy or addition of H3PO4 was found to suppress the corrosion rate. H3PO4 increased the rates of both hydrogen and oxygen evolution reactions at high overpotentials for all alloys. Except for Cu-containing alloy, H3PO4 had a slight positive effect on PbO2 formation.The self-discharge of PbO2 under polarization or opencircuitconditions increased in the presence of H3PO4 but the positive grid corrosion decreased, except for the As-containing alloy. Impurity-containing alloys showed significantly lower self-discharge rate in the presence of H3PO4 than in its absence. Impedance measurement was able to detect and quantify the formation of the highly insulating inner PbO layer beneath the outer PbSO4 layer and its transformation to the conducting PbO2, during the oxidation of alloys under constant current conditions.H3PO4 significantly enhanced the formation of PbO in thepresence of impurities, especially Sb

Energy and Momentum Distributions of Kantowski and Sachs Space-time

We use the Einstein, Bergmann-Thomson, Landau-Lifshitz and Papapetrou energy-momentum complexes to calculate the energy and momentum distributions of Kantowski and Sachs space-time. We show that the Einstein and Bergmann-Thomson definitions furnish a consistent result for the energy distribution, but the definition of Landau-Lifshitz do not agree with them. We show that a signature switch should affect about everything including energy distribution in the case of Einstein and Papapetrou prescriptions but not in Bergmann-Thomson and Landau-Lifshitz prescriptions.Comment: 12 page

Smart Bagged Tree-based Classifier optimized by Random Forests (SBT-RF) to Classify Brain- Machine Interface Data

Brain-Computer Interface (BCI) is a new technology that uses electrodes and sensors to connect machines and computers with the human brain to improve a person\u27s mental performance. Also, human intentions and thoughts are analyzed and recognized using BCI, which is then translated into Electroencephalogram (EEG) signals. However, certain brain signals may contain redundant information, making classification ineffective. Therefore, relevant characteristics are essential for enhancing classification performance. . Thus, feature selection has been employed to eliminate redundant data before sorting to reduce computation time. BCI Competition III Dataset Iva was used to investigate the efficacy of the proposed system. A Smart Bagged Tree-based Classifier (SBT-RF) technique is presented to determine the importance of the features for selecting and classifying the data. As a result, SBT-RF is better at improving the mean accuracy of the dataset. It also decreases computation cost and training time and increases prediction speed. Furthermore, fewer features mean fewer electrodes, thus lowering the risk of damage to the brain. The proposed algorithm has the greatest average accuracy of ~98% compared to other relevant algorithms in the literature. SBT-RF is compared to state-of-the-art algorithms based on the following performance metrics: Confusion Matrix, ROC-AUC, F1-Score, Training Time, Prediction speed, and Accuracy

Scanning tunneling spectroscopy characterization of the pseudogap and the x = 1/8 anomaly in La2-xSrxCuO4 thin films

Using scanning tunneling spectroscopy we examined the local density of states of thin c-axis La2-xSrxCuO4 films, over wide doping and temperature ranges. We found that the pseudogap exists only at doping levels lower than optimal. For x = 0.12, close to the 'anomalous' x = 1/8 doping level, a zero bias conductance peak was the dominant spectral feature, instead of the excepted V- shaped (c-axis tunneling) gap structure. We have established that this surprising effect cannot be explained by tunneling into (110) facets. Possible origins for this unique behavior are discussed.Comment: 15 pages, 6 figure

DGGE-RAPD analysis as a useful tool for cultivar identification

Denaturing gradient gel electrophoresis-random amplified polymorphic DNA (DGGE-RAPD) was used to overcome the main drawbacks of RAPD (i.e., the low levels of reproducibility and polymorphism). As a model, six barley cultivars of known origin were tested for RAPD markers using DGGE methodology with 29 arbitrary primers. Among a total of 418 bands observed, as high as 99 were polymorphic. Comparison between agarose-RAPD and DGGE-RAPD revealed that the latter was highly reproducible and gave higher level of polymorphism and consequently more markers. The relationships among barley cultivars derived from this study based on DGGE-RAPD are consistent with the known lineage of these cultivars. In conclusion, we recommend the use of DGGE-RAPD as an alternative tool to the more costly DNA-based analysis in cultivar identification in laboratories with limited funds.Key words: Denaturing gradient gel electrophoresis-random amplified polymorphic DNA, artificial heteroduplex, dendogram, lineage