1,002 research outputs found

    Mjerenje probojnih napona za više katodnih materijala u Townsendovom izboju

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    The breakdown potentials have been measured for argon and helium discharges using three different cathode materials: aluminium, silver and magnesium. The measurements show that lower breakdown potentials are associated with lower work function of the cathode material. For the three different cathodes, the secondary ionization coefficients have been estimated using the measured values of the breakdown potentials and the first ionization coefficient, in the range 0.60 to 2.25 V/[Pa cm] (80 to 300 V/[torr cm]) for Ar discharge and in the range of 0.15 to 1.80 V/[Pa cm] (20 to 240 V/[torr cm]) for He discharge. The minimum breakdown potential has been found at (pd)min = 80 Pa cm (0.6 torr cm) in Ar discharge and at 530 Pa cm (4.0 torr cm) in He discharge.Mjerili smo probojne potencijale za izboj u argonu i heliju s trima katodnim materijalima: aluminijem, srebrom i magnezijem. Mjerenja pokazuju da su niži probojni naponi povezani s nižim radnim funkcijama. Odredili smo sekundarne ionizacijske koeficijente za te tri vrste katoda na osnovi izmjerenih probojnih napona i prvih ionizacijskih koeficijenata, u području 0.60 to 2.25 V/[Pa cm] za izboj u Ar i u području 0.15 to 1.80 V/[Pa cm] za izboj u He. Najniži probojni napon za izboj u Ar iznosi (pd)min = 80 Pa cm, a za izboj u He 530 Pa cm (4.0 torr cm)

    Mjerenje probojnih napona za više katodnih materijala u Townsendovom izboju

    Get PDF
    The breakdown potentials have been measured for argon and helium discharges using three different cathode materials: aluminium, silver and magnesium. The measurements show that lower breakdown potentials are associated with lower work function of the cathode material. For the three different cathodes, the secondary ionization coefficients have been estimated using the measured values of the breakdown potentials and the first ionization coefficient, in the range 0.60 to 2.25 V/[Pa cm] (80 to 300 V/[torr cm]) for Ar discharge and in the range of 0.15 to 1.80 V/[Pa cm] (20 to 240 V/[torr cm]) for He discharge. The minimum breakdown potential has been found at (pd)min = 80 Pa cm (0.6 torr cm) in Ar discharge and at 530 Pa cm (4.0 torr cm) in He discharge.Mjerili smo probojne potencijale za izboj u argonu i heliju s trima katodnim materijalima: aluminijem, srebrom i magnezijem. Mjerenja pokazuju da su niži probojni naponi povezani s nižim radnim funkcijama. Odredili smo sekundarne ionizacijske koeficijente za te tri vrste katoda na osnovi izmjerenih probojnih napona i prvih ionizacijskih koeficijenata, u području 0.60 to 2.25 V/[Pa cm] za izboj u Ar i u području 0.15 to 1.80 V/[Pa cm] za izboj u He. Najniži probojni napon za izboj u Ar iznosi (pd)min = 80 Pa cm, a za izboj u He 530 Pa cm (4.0 torr cm)

    Thermal Equilibrium as an Initial State for Quantum Computation by NMR

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    We present a method of using a nuclear magnetic resonance computer to solve the Deutsch-Jozsa problem in which: (1) the number of molecules in the NMR sample is irrelevant to the number of qubits available to an NMR quantum computer, and (2) the initial state is chosen to be the state of thermal equilibrium, thereby avoiding the preparation of pseudopure states and the resulting exponential loss of signal as the number of qubits increases. The algorithm is described along with its experimental implementation using four active qubits. As expected, measured spectra demonstrate a clear distinction between constant and balanced functions.Comment: including 4 figure

    Adrenal lesions found incidentally: how to improve clinical and cost-effectiveness

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    Introduction Adrenal incidentalomas are lesions that are incidentally identified while scanning for other conditions. While most are benign and hormonally non-functional, around 20% are malignant and/or hormonally active, requiring prompt intervention. Malignant lesions can be aggressive and life-threatening, while hormonally active tumours cause various endocrine disorders, with significant morbidity and mortality. Despite this, management of patients with adrenal incidentalomas is variable, with no robust evidence base. This project aimed to establish more effective and timely management of these patients. Methods We developed a web-based, electronic Adrenal Incidentaloma Management System (eAIMS), which incorporated the evidence-based and National Health Service–aligned 2016 European guidelines. The system captures key clinical, biochemical and radiological information necessary for adrenal incidentaloma patient management and generates a pre-populated outcome letter, saving clinical and administrative time while ensuring timely management plans with enhanced safety. Furthermore, we developed a prioritisation strategy, with members of the multidisciplinary team, which prioritised high-risk individuals for detailed discussion and management. Patient focus groups informed process-mapping and multidisciplinary team process re-design and patient information leaflet development. The project was partnered by University Hospital of South Manchester to maximise generalisability. Results Implementation of eAIMS, along with improvements in the prioritisation strategy, resulted in a 49% reduction in staff hands-on time, as well as a 78% reduction in the time from adrenal incidentaloma identification to multidisciplinary team decision. A health economic analysis identified a 28% reduction in costs. Conclusions The system’s in-built data validation and the automatic generation of the multidisciplinary team outcome letter improved patient safety through a reduction in transcription errors. We are currently developing the next stage of the programme to proactively identify all new adrenal incidentaloma cases

    A Modified Cooling System for Stand Alone PV Greenhouse in Remote Areas

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    Abstract. Agricultural efforts are normally carried out in remote areas where electricity from national electric grid may not exist or grid connection is very expensive. Greenhouses industry is one of the most important agricultural practices in remote areas. Greenhouses help in extending the gardening activities and allows us to cultivate certain plants all over the year; by controlling air temperature and relative humidity inside greenhouse. In greenhouses, cooling and pumping equipments dominate the demand for electricity. Therefore, a stand-alone photovoltaic (PV) system is necessary to feed that demand. Medicinal herbs, for example are the most suitable plants to be cultivated in the greenhouses. They often need a temperature range of 15 -21 oC and about 70% relative humidity to grow. As the climate in Egypt is not suitable all over the year to cultivate these medicinal herbs, it is preferable and necessary to use PV-based control greenhouse to cultivate these medicinal herbs in Egyptian remote areas. This paper presents a proposed greenhouse cooling system, which uses a stand-alone PV system to feed the electrical loads of the greenhouse. At the same time, it introduces the complete sizing procedure of the greenhouse stand-alone PV system

    Rapid solution of problems by nuclear-magnetic-resonance quantum computation

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    We offer an improved method for using a nuclear-magnetic-resonance quantum computer (NMRQC) to solve the Deutsch-Jozsa problem. Two known obstacles to the application of the NMRQC are exponential diminishment of density-matrix elements with the number of bits, threatening weak signal levels, and the high cost of preparing a suitable starting state. A third obstacle is a heretofore unnoticed restriction on measurement operators available for use by an NMRQC. Variations on the function classes of the Deutsch-Jozsa problem are introduced, both to extend the range of problems advantageous for quantum computation and to escape all three obstacles to use of an NMRQC. By adapting it to one such function class, the Deutsch-Jozsa problem is made solvable without exponential loss of signal. The method involves an extra work bit and a polynomially more involved Oracle; it uses the thermal-equilibrium density matrix systematically for an arbitrary number of spins, thereby avoiding both the preparation of a pseudopure state and temporal averaging.Comment: 19 page
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