76 research outputs found

    Finite quantum tomography via semidefinite programming

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    Using the the convex semidefinite programming method and superoperator formalism we obtain the finite quantum tomography of some mixed quantum states such as: qudit tomography, N-qubit tomography, phase tomography and coherent spin state tomography, where that obtained results are in agreement with those of References \cite{schack,Pegg,Barnett,Buzek,Weigert}.Comment: 25 page

    Developing Ontologies withing Decentralized Settings

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    This chapter addresses two research questions: “How should a well-engineered methodology facilitate the development of ontologies within communities of practice?” and “What methodology should be used?” If ontologies are to be developed by communities then the ontology development life cycle should be better understood within this context. This chapter presents the Melting Point (MP), a proposed new methodology for developing ontologies within decentralised settings. It describes how MP was developed by taking best practices from other methodologies, provides details on recommended steps and recommended processes, and compares MP with alternatives. The methodology presented here is the product of direct first-hand experience and observation of biological communities of practice in which some of the authors have been involved. The Melting Point is a methodology engineered for decentralised communities of practice for which the designers of technology and the users may be the same group. As such, MP provides a potential foundation for the establishment of standard practices for ontology engineering

    The study of atmospheric ice-nucleating particles via microfluidically generated droplets

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    Ice-nucleating particles (INPs) play a significant role in the climate and hydrological cycle by triggering ice formation in supercooled clouds, thereby causing precipitation and affecting cloud lifetimes and their radiative properties. However, despite their importance, INP often comprise only 1 in 10³–10⁶ ambient particles, making it difficult to ascertain and predict their type, source, and concentration. The typical techniques for quantifying INP concentrations tend to be highly labour-intensive, suffer from poor time resolution, or are limited in sensitivity to low concentrations. Here, we present the application of microfluidic devices to the study of atmospheric INPs via the simple and rapid production of monodisperse droplets and their subsequent freezing on a cold stage. This device offers the potential for the testing of INP concentrations in aqueous samples with high sensitivity and high counting statistics. Various INPs were tested for validation of the platform, including mineral dust and biological species, with results compared to literature values. We also describe a methodology for sampling atmospheric aerosol in a manner that minimises sampling biases and which is compatible with the microfluidic device. We present results for INP concentrations in air sampled during two field campaigns: (1) from a rural location in the UK and (2) during the UK’s annual Bonfire Night festival. These initial results will provide a route for deployment of the microfluidic platform for the study and quantification of INPs in upcoming field campaigns around the globe, while providing a benchmark for future lab-on-a-chip-based INP studies

    Influence of PbO and TiO2 additives on the microstructure development and magnetic properties of Ni–Zn soft ferrites

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    This paper focuses on the effect of PbO and TiO2 on the magnetic properties and microstructural development of Fe2Ni0.64Zn0.36O4 soft ferrite. Ferrite was added to these oxides, ranging from 0 to 3.2 wt% in steps of 0.4 wt%. The results showed that with increasing the amount of PbO up to a certain percentage, relative density, grain size and magnetic permeability increase and then decrease. This additive caused to increase DC-resistivity, power loss and decrease in magnetic permeability and saturation magnetization. TiO2 revealed no considerable effect on the grain growth and densification. In contrast this additive due to the doping of the high valent Ti4+ ions to the lattice affects the magnetic and electrical properties noticeably. TiO2 improved the loss properties (up to 1.2 wt%) and magnetic permeability (up to 2.0 wt%) but reduced the saturation magnetization, and DC-resistivity of ferrite

    Randomized control trial:Comparison of Triple Therapy plus Probiotic Yogurt vs. Standard Triple Therapy on Helicobacter Pylori Eradication

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    BACKGROUND: Treatment of Helicobacter pylori (H. pylori) as a major cause of gastric diseases is of utmost concern.We aimed to assess efficacy of triple therapy (amoxicillin, clarithromycin and pantoprazole) plus probiotic yogurt (PY) on eradication of H.pylori. METHODS: Total 102 H. pylori positive patients were divided to 3 groups equally and randomly. For treatment of each group Amoxicillin, clarithromycin and pantoprazole were used. Group A had additional PY, Group B ordinary low fat yogurt and Group C just had triple therapy in their regimen as well. These groups were compared regarding treatment success. RESULTS: Total number of 88 patients finished the treatment course. The most common experienced side effects were dysgeusia in groups A and B (25.8% and 32.3%, respectively), and dysgeusia with diarrhea and abdominal pain (30.8%) in group C. Eradication rate was, respectively, 61.3%, 64.5% and 71.3% in group A, B and C of which difference was not statistically significant (P> 0.05). However, the difference between 3 groups in regard to education level was statistically significant (P=0.005). CONCLUSION: PY enriched triple therapy has decreased side effects of antibiotics consumption; however, this has no impact on eradication of Hpylori. PY and triple therapy can be used concomitantly to increase the patient tolerance

    On the use of boundary conditions and thermophysical properties of nanoparticles for application of nanofluids as coolant in nuclear power plants; a numerical study

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    In the first part of the present study, a thermal-hydraulic subchannel code hereafter called \u2018SUBTHAC\u2019 is developed to evaluate the enhancement effects of nanoparticles in core heat transfer. The first version of SUBTHAC (V1.0) can analyze the steady state flow of coolant with Al2O3, TiO2 or CuO as nanoparticles (other types of nanoparticles can be added by the user). Different output profiles can be selected such as fluid temperature, pressure and velocity for each subchannel, clad outside temperature for each fuel rod, axial and lateral mass flow, etc. SUBTHAC uses a dedicated algorithm to solve the subchannel equations and, unlike many other codes, allows for thermophysical parameters of nanoparticles to be a function of the temperature, leading to improvement the accuracy of results. Results computed by SUBTHAC for base fluid (pure water) are validated against those obtained by COBRA-EN code. In the next step, with the aim of validating the capability of nanofluid analysis of SUBTHAC code, its nanofluids results have been validated against reference CFD simulations. After the validation, comprehensive numerical comparisons are conducted to assess the enhancement of thermal-hydraulic parameters by using nanofluids. It is shown that, among Al2O3, TiO2 and CuO nanofluids with volumetric concentration in the range of 1\u20135%, TiO2-3% and CuO-3% are the best choices to increase fluid outlet temperature and decrease clad temperature, respectively. Using nanofluids with a concentration higher than 3% volumetric is not justifiable as the core pressure drop increases up to more than 20%. In the second part of the manuscript, some relevant remarks are put forward on the assignment of boundary conditions (BC, i.e. inlet velocity/inlet mass flux/inlet Reynolds number) and the adoption of reliable values for specific heat capacity of nanoparticles in operational temperature of NPPs. The effects of using the above boundary conditions and incorrect values of the specific heat (as adopted in the literature so far) are depicted by presenting some profiles of coolant and clad temperature. Selecting different BCs and incorrect values of specific heat for nanoparticles can jeopardize the results of calculations

    ELECTROPHORETIC DEPOSITION OF TIO2-MULTI-WALLED CARBON NANOTUBE COMPOSITE COATINGS: MORPHOLOGICAL STUDY

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    A homogenous TiO2 / multi-walled carbon nanotubes(MWCNTs) composite film were prepared by electrophoretic co-deposition from organic suspension on a stainless steel substrate.  In this study, MWCNTs was incorporated to the coating because of their long structure and their capability to be functionalized by different inorganic groups on the surface. FTIR spectroscopy showed the existence of carboxylic groups on the modified carbon nanotubes surface. The effect of applied electrical fields, deposition time and concentration of nanoparticulates on coatings morphology were investigated by scanning electron microscopy. It was found that combination of MWCNTs within TiO2 matrix eliminating micro cracks presented on TiO2 coating. Also, by increasing the deposition voltages, micro cracks were increased. SEM observation of the coatings revealed that TiO2/multi-walled carbon nanotubes coatings produced from optimized electric field was uniform and had good adhesive to the substrate

    Dry Sliding Wear and Corrosion Performance of Mg-Sn-Ti Alloys Produced by Casting and Extrusion

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    The aim of the present study is to investigate the role of Ti on corrosion and the wear properties of Mg-5Sn-xTi (x = 0, 0.15, 0.75, 1.5 wt.%) alloys. The samples were fabricated by conventional casting followed by hot extrusion, and the studies were examined by means of a pin-on-disc tribometer at various loads of 6, 10, and 20 N with constant sliding velocities of 0.04 m/s at ambient temperature. The corrosion performance, using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), was studied in a basic solution containing 3.5 wt.% NaCl. The observation indicated a drop in the wear rate with an increase in Ti, while the average coefficient of friction was raised in higher Ti contents compared to the base material. The sample with 0.15 wt.% Ti exhibited superior wear properties at 6 and 10 N of normal force, while the sample with 0.75 wt.% Ti presented better wear resistance for 20 N. Electrochemical test observations demonstrated that the Ti deteriorated the corrosion features of the Mg-5Sn alloy, owing to the galvanic effects of Ti. The Mg-5Sn alloy exhibited excellent corrosion behavior (corrosion potential (Ecorr) = −1.45V and current density (Icorr) = 43.92 A/cm2). The results indicated the significant role of Ti content in modulating wear and corrosion resistance of the Mg-5Sn alloy
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