Acousto-optic and opto-acoustic modulation in piezo-optomechanical circuits

Acoustic wave devices provide a promising chip-scale platform for efficiently coupling radio frequency (RF) and optical fields. Here, we use an integrated piezo-optomechanical circuit platform that exploits both the piezoelectric and photoelastic coupling mechanisms to link 2.4 GHz RF waves to 194 THz (1550 nm) optical waves, through coupling to propagating and localized 2.4 GHz acoustic waves. We demonstrate acousto-optic modulation, resonant in both the optical and mechanical domains, in which waveforms encoded on the RF carrier are mapped to the optical field. We also show opto-acoustic modulation, in which the application of optical pulses gates the transmission of propagating acoustic waves. The time-domain characteristics of this system under both pulsed RF and pulsed optical excitation are considered in the context of the different physical pathways involved in driving the acoustic waves, and modeled through the coupled mode equations of cavity optomechanics.Comment: 8 pages, 6 figure

Scaling relation for determining the critical threshold for continuum percolation of overlapping discs of two sizes

We study continuum percolation of overlapping circular discs of two sizes. We propose a phenomenological scaling equation for the increase in the effective size of the larger discs due to the presence of the smaller discs. The critical percolation threshold as a function of the ratio of sizes of discs, for different values of the relative areal densities of two discs, can be described in terms of a scaling function of only one variable. The recent accurate Monte Carlo estimates of critical threshold by Quintanilla and Ziff [Phys. Rev. E, 76 051115 (2007)] are in very good agreement with the proposed scaling relation.Comment: 4 pages, 3 figure

Coronary heart disease risk factors in Newfoundland children

A cross-sectional epidemiological study was carried out to investigate the distribution of coronary heart disease (CHD) risk factors in children aged 8-10 and 14-16 years living in two regions of Newfoundland characterised by high and low CHD mortality rates among adults. The age-adjusted CHD mortality rates for males and females in the high mortality region (HMR) were 298 and 131 per 100,000 respectively, compared to 198 and 85 per 100,000 population for males and females respectively in the low mortality region (LMR). Participants attended schools, randomly chosen from two communities in each region. -- Height, weight, systolic and diastolic blood pressures were measured in Phase I. Also, an EKG was recorded and a questionnaire administered. -- In the HMR, 275 (87%) children aged 8-10 and 383 (89%) aged 14-16 years responded positively. In the LMR, 255 (94%) children aged 8-10 and 259 (89%) children aged 14-16 years participated. -- Ten-hour fasting blood samples were taken in Phase II. Participants in the first phase were eligible to give blood. Sera were analysed for total and HDL cholesterol, triglyceride, uric acid and glucose. In the HMR, 242 (88%) children aged 8-10 and 350 (91%) aged 14-16 years participated, compared to 240 (94%) children aged 8-10 and 201 (78%) aged 14-16 years from the LMR. -- The following significant results were considered to be of epidemiological importance: -- 1. Boys and girls, aged 8-10 and 14-16 years, in the HMR had significantly higher mean systolic and diastolic blood pressures than those in the LMR. -- 2. Body mass index (weight/height²) was significantly greater for boys and girls aged 14-16 years in the HMR than in the LMR. This risk factor was a strong discriminant between this age group in the two mortality regions. -- 3. The prevalence of elevated levels of systolic blood pressure was significantly higher for boys and girls aged 8-10 years and for boys aged 14-16 in the HMR. -- 4. Boys and girls aged 14-16 years in the HMR had a significantly higher prevalence of elevated diastolic blood pressure. -- 5. The total number of boys aged 14-16 years with one and clusters of two and three primary CHD risk factors simultaneously was significantly higher in the HMR. -- 6. The prevalence of Type IV hyperprebetalipoproteinemia was significantly higher in children living in the HMR. -- The risk of developing premature CHD in adulthood appears to be higher for chi1dren in the HMR. A primary prevention CHD program should, therefore, be started in this region. This program should employ health education as a means of improving nutrition, weight control, physical activity and preventing the onset of smoking. The effectiveness of this program, in reducing risk factor levels in a young population, should be evaluated

AN OVERVIEW OF TRAJECTORY DATA MINING TECHNIQUES TO ENHANCE THE MOBILITY DETECTION

Trajectory data mining plays a most important role in the real world application whichenables to predict the moving location details of humans, vehicles, animals and so on.Trajectory data analysis is a most difficult task due to frequent changing location details ofhumans due to its continuous mobility. Trajectorydata might consist of more noise detailswhich is more complex to analysis. It is required to have more concentration on the trajectorydata analysis to ensure the accurate trajectory data mining outcome. There are variousresearch methods had been proposed by different researchers to perform the analysis oftrajectory data. In this analysis work, discussion of various trajectory data analysis techniqueshas been given. This analysis work provides the detailed discussion of working procedure ofeach trajectory data analysis method with the samples. And also comparison evaluation of theresearch techniques in terms of merits and demerits is given in order to evaluate theperformance. Finally numerical evaluation of the research techniques is provided based ondifferent performance metrics. From this numerical evaluation, best method has been chosenas base work to enhance the trajectory data minin

Wavelength transduction from a 3D microwave cavity to telecom using piezoelectric optomechanical crystals

Microwave to optical transduction has received a great deal of interest from the cavity optomechanics community as a landmark application for electro-optomechanical systems. In this Letter, we demonstrate a novel transducer that combines high-frequency mechanical motion and a microwave cavity for the first time. The system consists of a 3D microwave cavity and a gallium arsenide optomechanical crystal, which has been placed in the microwave electric field maximum. This allows the microwave cavity to actuate the gigahertz-frequency mechanical breathing mode in the optomechanical crystal through the piezoelectric effect, which is then read out using a telecom optical mode. The gallium arsenide optomechanical crystal is a good candidate for low-noise microwave-to-telecom transduction, as it has been previously cooled to the mechanical ground state in a dilution refrigerator. Moreover, the 3D microwave cavity architecture can naturally be extended to couple to superconducting qubits and to create hybrid quantum systems

Synthesis and Antimicrobial Activity of Some Novel Thiophene Carbohydrazide Derivatives

ABSTRACT The present paper describes the synthesis and antibacterial activity of fifteen novel (E)-N'-benzylidene-3-methoxy-4(4-nitrophenyl)thiophene) benzohydrazide derivatives (5a-m) from commercially available methyl-4-bromo-3-methoxythiophene-2-carboxylate as starting material. Th

An image classification approach to analyze the suppression of plant immunity by the human pathogen <it>Salmonella</it> Typhimurium

<p>Abstract</p> <p>Background</p> <p>The enteric pathogen <it>Salmonella</it> is the causative agent of the majority of food-borne bacterial poisonings. Resent research revealed that colonization of plants by <it>Salmonella</it> is an active infection process. <it>Salmonella</it> changes the metabolism and adjust the plant host by suppressing the defense mechanisms. In this report we developed an automatic algorithm to quantify the symptoms caused by <it>Salmonella</it> infection on <it>Arabidopsis</it>.</p> <p>Results</p> <p>The algorithm is designed to attribute image pixels into one of the two classes: healthy and unhealthy. The task is solved in three steps. First, we perform segmentation to divide the image into foreground and background. In the second step, a support vector machine (SVM) is applied to predict the class of each pixel belonging to the foreground. And finally, we do refinement by a neighborhood-check in order to omit all falsely classified pixels from the second step. The developed algorithm was tested on infection with the non-pathogenic <it>E. coli</it> and the plant pathogen <it>Pseudomonas syringae</it> and used to study the interaction between plants and <it>Salmonella</it> wild type and T3SS mutants. We proved that T3SS mutants of <it>Salmonella</it> are unable to suppress the plant defenses. Results obtained through the automatic analyses were further verified on biochemical and transcriptome levels.</p> <p>Conclusion</p> <p>This report presents an automatic pixel-based classification method for detecting “unhealthy” regions in leaf images. The proposed method was compared to existing method and showed a higher accuracy. We used this algorithm to study the impact of the human pathogenic bacterium <it>Salmonella</it> Typhimurium on plants immune system. The comparison between wild type bacteria and T3SS mutants showed similarity in the infection process in animals and in plants. Plant epidemiology is only one possible application of the proposed algorithm, it can be easily extended to other detection tasks, which also rely on color information, or even extended to other features.</p

Discrimination of filled and unfilled grains of rice panicles using thermal and RGB images

In recent days, the agricultural research community is focusing on the development of different varieties of aerobic rice, as it consumes less water for its growth. In general, the yield of a crop is considered as a critical performance metric to evaluate different varieties of rice. The count of filled grains in panicles provides a measure for the yield of a crop. The evaluation of yield is a laborious, tedious process and requires human intervention. Hence, this study aims to automate the process for differentiating filled and unfilled grains of rice across different genotypes/varieties and also to help agricultural scientists in the rapid evaluation of different varieties. More precisely, this paper proposes two novel methods that involve RGB and thermal images: (a) Discrimination based on RGB Images (DRI) (b) Discrimination based on Thermal Images (DTI). The study of proposed methods on 15 rice-panicles of different genotypes indicates that DRI method, which involves colour of grains, is found to be challenging to discriminate between filled and unfilled grains. Whereas, DTI method, which makes use of thermal images in differentiating filled and unfilled grains, is found to be profoundly convenient. The performance analysis demonstrates that the proposed DTI method, with averaged absolute errors (AAEs) in discriminating filled grains (2.66%) and unfilled grains (11.389%), outperforms the proposed DRI method with an AAEs in discriminating filled grains (10.664%) and unfilled grains (34.296%). The present investigation resulted in the development of DTI method to discriminate against the filled and unfilled grains across genotypes, and it can be used in rice improvement programs in the future

XAFS study of copper(II) diethylenetriamine complexes having different coordination geometries

XAFS of three Cu(II) diethylenetriamine complexes (in crystalline form) having different coordination geometries have been investigated. First complex has distorted tetragonal pyramidal, second has distorted square planar and third has distorted square pyramidal geometry. The difference in coordination geometries has been inferred from the differences in pre-edge peak, rising part of edge and in shape of white line, which are seen clearly in the derivative XANES spectra. The distortion in geometry has been correlated with the intensity of peaks in derivative spectra. These inferences have been corroborated from EXAFS analysis where the different paths have been used in the theoretical fits in R space to show contributions of different scatterers at different distances