301 research outputs found

    INSERTION METHOD USING MUSIC NOTES

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    Communication signals are openly available as they are propagated. Secured transmission is always a question and various methods are devised. ƂĀ Use of music notes is not in wide use in encryption of data. Any musical note consists of seven basic keys. In this paper we propose an insertion method with the seven music keys are used as a tool of encryption

    Demonstrating an absolute quantum advantage in direct absorption measurement

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    Engineering apparatus that harness quantum theory promises to offer practical advantages over current technology. A fundamentally more powerful prospect is that such quantum technologies could out-perform any future iteration of their classical counterparts, no matter how well the attributes of those classical strategies can be improved. Here, for optical direct absorption measurement, we experimentally demonstrate such an instance of an absolute advantage per photon probe that is exposed to the absorbative sample. We use correlated intensity measurements of spontaneous parametric downconversion using a commercially available air-cooled CCD, a new estimator for data analysis and a high heralding efficiency photon-pair source. We show this enables improvement in the precision of measurement, per photon probe, beyond what is achievable with an ideal coherent state (a perfect laser) detected with 100% efficient and noiseless detection. We see this absolute improvement for up to 50% absorption, with a maximum observed factor of improvement of 1.46. This equates to around 32% reduction in the total number of photons traversing an optical sample, compared to any future direct optical absorption measurement using classical light

    A novel Artificial Neural Network-based streamline tracing strategy applied to hypersonic waverider design

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    Streamline tracing in conical hypersonic flows is essential for designing high-performance waverider and intake. Conventionally, the streamline equations are solved after obtaining the velocity field from the solution of the axisymmetric conical flow field. The hypersonic waverider shape is generated from the base conical flow field by repeatedly applying the streamline tracing approach along several planes. When exploring the design space for optimization of the waverider, streamline tracing can be computationally expensive. We provide a novel strategy where first the Taylor-Maccoll equations for the inviscid axisymmetric conical flowfield and the streamlines from the shock are solved for a wide range of cone angle and Mach number conditions resulting in an extensive database. The streamlines are parametrized by a third-order polynomial, and an Artificial Neural Network (ANN) is trained to predict the coefficients of the polynomial for arbitrary inputs of Mach number, cone angle, and streamline originating location on the shock . We apply this strategy to design a cone derived waverider and compare the geometry obtained with the standard conical waverider design method and the simplified waverider design method. The ANN technique is highly accurate, with a difference of 0.68% with the standard in the coordinates of the waverider. RANS computations show that the ANN derived waverider does not indicate severe flow spillage at the leading edge, which is observed in the waverider generated from the simplified method. The new ANN-based approach is 20 times faster than the conventional method

    Utilizing Dynamic Tensiometry to Quantify Contact Angle Hysteresis and Wetting State Transitions on Nonwetting Surfaces

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    Goniometric techniques traditionally quantify two parameters, the advancing and receding contact angles, that are useful for characterizing the wetting properties of a solid surface; however, dynamic tensiometry, which measures changes in the net force on a surface during the repeated immersion and emersion of a solid into a probe liquid, can provide further insight into the wetting properties of a surface. We detail a framework for analyzing tensiometric results that allows for the determination of wetting hysteresis, wetting state transitions, and characteristic topographical length scales on textured, nonwetting surfaces, in addition to the more traditional measurement of apparent advancing and receding contact angles. Fluorodecyl POSS, a low-surface-energy material, was blended with commercially available poly(methyl methacrylate) (PMMA) and then dip- or spray-coated onto glass substrates. These surfaces were probed with a variety of liquids to illustrate the effects of probe liquid surface tension, solid surface chemistry, and surface texture on the apparent contact angles and wetting hysteresis of nonwetting surfaces. Woven meshes were then used as model structured substrates to add a second, larger length scale for the surface texture. When immersed into a probe liquid, these spray-coated mesh surfaces can form a metastable, solidā€“liquidā€“air interface on the largest length scale of surface texture. The increasing hydrostatic pressure associated with progressively greater immersion depths disrupts this metastable, composite interface and forces penetration of the probe liquid into the mesh structure. This transition is marked by a sudden change in the wetting hysteresis, which can be systematically probed using spray-coated, woven meshes of varying wire radius and spacing. We also show that dynamic tensiometry can accurately and quantitatively characterize topographical length scales that are present on microtextured surfaces.United States. Air Force Office of Scientific Research (W 911NF-07-D-0004

    Solution spraying of poly(methyl methacrylate) blends to fabricate microtextured, superoleophobic surfaces

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    We describe a simple technique to prepare superhydrophobic and superoleophobic microtextured surfaces by spray coating a blend of poly(methyl methacrylate) (PMMA) and the low surface energy molecule 1H,1H,2H,2H-heptadecafluorodecyl polyhedral oligomeric silsesquioxane (fluorodecyl POSS, Ī³[subscript sv] ā‰ˆ 10 mN/m) using an air brush with a pressurized nitrogen stream. Scanning electron micrographs show the formation of microtextured surfaces possessing re-entrant curvature; a critical feature for obtaining liquid repellency with low surface tension liquids. The surface morphology can be tuned systematically from a corpuscular or spherical microstructure to a beads-on-string structure and finally to bundled fibers by controlling the solution concentration and molecular weight of the sprayed polymer. The oleophobicity of the resulting structures is characterized by advancing and receding contact angle measurements with liquids of a range of surface tensions.United States. Army Research Office (Contract W911NF-07-D-0004)Air Force Research Laboratory (Wright-Patterson Air Force Base, Ohio). Propulsion DirectorateUnited States. Air Force Office of Scientific Researc

    Hand hygiene practices among health providers working in tertiary care hospitals in and around Hyderabad, Telangana State, South India

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    Background:Infection control is ac knowledge universally as a solid and essential basis towards patientsā€™ safety and support the reduction of health care association infection and their consequences. Simple hand hygiene is cost effective method in preventing cross transmission of microorganism. The compliance of health providers with hand washing guidelines seems to be vital in preventing the disease transmission among patients but unfortunately hand hygiene practices have been found to be faulty in most of the health care facilities including tertiary care hospitals.Methods:A cross-sectional study was conducted to evaluate the awareness and compliance of hand hygiene among different health care providers, that includes 100 doctors, 100 nurses, 100 medical students, 50 ward boys working in different tertiary care Hospitals attachedĀ  to medical colleges, in and around Hyderabad, in Telangana state (India) from April to July - 2014. Knowledge was assessed using WHO hand hygiene questionnaire. Attitude and practices was evaluated by using self-structure questionnaire. A value less than 0.05 was considered significant.Results: Only 16.5 % of participants had good knowledge regarding hand hygiene. Nursesā€™ knowledge is better than doctors, Knowledge, attitude and practices of doctor and nurses were better than medical students and ward boys, trained staff have better knowledge on hand hygiene and effective infection control committees have some impact on hand hygiene practicesConclusion:Hand hygiene practices among health providers irrespective of public sector or private sector hospitals were found to be low. It was concluded that serious efforts are need to improve the hand hygiene practices among all health providers.

    Does Reporting Heterogeneity Bias The Measurement of Health Disparities?

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    Heterogeneity in reporting of health by socio-economic and demographic characteristics potentially biases the measurement of health disparities. We use anchoring vignettes to identify reporting heterogeneity in self reports on health for Indonesia, India and China. Correcting for reporting heterogeneity tends to reduce estimated disparities in health by age, sex (not Indonesia), urban/rural and education (not China) and to increase income disparities in health. Overall, while homogeneous reporting by socio-demographic group is significantly rejected, the results suggest that the size of the reporting bias in measures of health disparities is not large

    Innovative Method for the Estimation of Closure Velocity between RAT Driven Drogue and IFR Probe Air to Air refueling Flight Trials

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    Air-to-air refueling for a fighter platform is a force multiplier in terms of increasing its combat radius and payload carrying ability. Adapting for such a facility especially for an aircraft under design and development is a challenging task. It requires rigorous ground and flight testing to meet the certification standards. One of important flight test parameter that needs to be validated for structural impact load calculations and certification needs is the closure velocity. The air-to-air refueller was equipped with a Ram-air-turbine powered drogue and chute system. An innovative methodology of estimating the closure velocity between the drogue of the mother aircraft and the in-flight refueling probe of the receiving aircraft was evolved. The method was employed and validated during the air-to-air refueling trials of a prototype fighter platform. The intention of this paper is to explain the methodology employed and deliberate the results obtained with respect to the air-to-air refueling certification

    Measurement of Hydrogen Peroxide Influx Into Cells: Preparation For Measurement Using On-Chip Microelectrode Array

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    Hydrogen peroxide (H2O2) is commonly known as a toxic reactive oxidative species (ROS) for cells. Recent studies have found evidence that H2O2 is also an important cellular signalling molecule. Quantifying cellular influx of H2O2 will contribute to researchersā€™ understanding of the role H2O2 plays in healthy cells and cells involved in the progression of cancers and degenerative diseases. This work utilizes an assay kit and fluorescence techniques to evaluate cell lines and conditions to create a model biological system for measuring cellular H2O2 consumption. Pancreatic beta cells (MIN6), astrocytes, and glioblastoma cells (GBM43 and GBAM1) were placed in 10 Ī¼M and 20 Ī¼M H2O2 solutions for up to 5 hours. The consumption of H2O2 was measured using an Amplex Red Hydrogen Peroxide/Peroxidase Assay Kit (Molecular Probes/Invitrogen). GBAM1 cells exposed to 20 Ī¼M H2O2 displayed the fastest rate of H2O2 consumption (4.8 Ā± 1.2 nmol H2O2/min/106 cells), followed by GBM43 cells (1.5Ā±0.46), astrocytes (1.1Ā±0.24), and MIN6 cells (0.29Ā±0.075). Additionally, the rate of consumption increased with increases in H2O2 concentration. In the future, an on-chip micro-electrode array (MEA) will be used for real-time electrochemical experiments to measure influx of H2O2 by astrocytes and GBAM1 cells with spatio-temporal resolution that the current techniques lack. The results from the electrochemical experiments will be compared to results from the assay kit to determine the ability of the MEA to accurately measure H2O2 concentration and flux. The MEA can be extended to a wide variety of cellular environments for analysis of additional real-time biological events
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