380 research outputs found

    Shot noise free conductance reduction in quantum wires

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    We show that a shot noise free current at conductance below 2 e^2/h is possible in short interacting quantum wires without spin-polarization. Our calculation is done for two exactly solvable limits of the ``Coulomb Tonks gas'', a one-dimensional gas of impenetrable electrons that can be realized in ultra-thin quantum wires. In both cases we find that charge transport through such a wire is noiseless at zero temperature while the conductance is reduced to e^2/h.Comment: 4 pages, 1 figur

    Frequency-dependent transport through a quantum dot in the Kondo regime

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    We study the AC conductance and equilibrium current fluctuations of a Coulomb blockaded quantum dot. A relation between the equilibrium spectral function and the linear AC conductance is derived which is valid for frequencies well below the charging energy of the quantum dot. Frequency-dependent transport measurements can thus give experimental access to the Kondo peak in the equilibrium spectral function of a quantum dot. We illustrate this in detail for typical experimental parameters using the numerical renormalization group method in combination with the Kubo formalism.Comment: 4 pages, 4 figure

    Phase Transitions in liquid Helium 3

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    The phase transitions of liquid Helium 3 are described by truncations of an exact nonperturbative renormalization group equation. The location of the first order transition lines and the jump in the order parameter are computed quantitatively. At the triple point we find indications for partially universal behaviour. We suggest experiments that could help to determine the effective interactions between fermion pairs.Comment: 4 pages, 6 figures, LaTe

    Electron transport and current fluctuations in short coherent conductors

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    Employing a real time effective action formalism we analyze electron transport and current fluctuations in comparatively short coherent conductors in the presence of electron-electron interactions. We demonstrate that, while Coulomb interaction tends to suppress electron transport, it may {\it strongly enhance} shot noise in scatterers with highly transparent conducting channels. This effect of excess noise is governed by the Coulomb gap observed in the current-voltage characteristics of such scatterers. We also analyze the frequency dispersion of higher current cumulants and emphasize a direct relation between electron-electron interaction effects and current fluctuations in disordered mesoscopic conductors.Comment: 16 pages, 4 figure

    DC-transport in superconducting point contacts: a full counting statistics view

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    We present a comprehensive theoretical analysis of the dc transport properties of superconducting point contacts. We determine the full counting statistics for these junctions, which allows us to calculate not only the current or the noise, but all the cumulants of the current distribution. We show how the knowledge of the statistics of charge transfer provides an unprecedented level of understanding of the different transport properties for a great variety of situations. We illustrate our results with the analysis of junctions between BCS superconductors, contacts between superconductors with pair-breaking mechanisms and short diffusive bridges. We also discuss the temperature dependence of the different cumulants and show the differences with normal contacts.Comment: revtex4, 20 pages, 15 figure

    Sacubitril/valsartan in heart failure: efficacy and safety in and outside clinical trials.

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    Heart failure (HF) treatment has changed substantially over the last 30 years, leading to significant reductions in mortality and hospital admissions in patients with HF with reduced ejection fraction (HFrEF). Currently, the optimization of guideline-directed chronic HF therapy remains the mainstay to further improve quality of life, mortality, and HF hospitalizations for patients with HFrEF. The angiotensin receptor-neprilysin inhibitor sacubitril/valsartan (S/V) has an important role in the treatment of patients with HFrEF. The PARADIGM-HF (Prospective Comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) randomized controlled trial has established solid evidence for the treatment of HFrEF in various subgroups. Apart from HFrEF, several studies have been conducted using S/V in various indications: patients hospitalized with acute decompensated HF, HF with preserved ejection fraction, acute myocardial infarction with reduced ejection fraction, uncontrolled and resistant hypertension, and chronic kidney disease. Data from the German Institute for Drug Use Evaluation reveal that implementation of S/V has increased steadily over time and, by the end of 2021, an estimated 266 000 patients were treated with S/V in Germany. The estimated cumulative real-world patient exposure is >5.5 million patient-treatment years worldwide. The number of patients treated with S/V largely exceeds the number of patients treated in clinical trials, and the current indication for S/V is larger than the strict inclusion/exclusion criteria of the randomized trials. Especially elderly patients, women, and patients with more and more severe comorbidities are underrepresented in the clinical trials. We therefore aimed to summarize the importance of S/V in HF in terms of efficacy and safety in clinical trials and daily clinical practice

    Model Ensembles of Ecosystem Services Fill Global Certainty and Capacity Gaps

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    Sustaining ecosystem services (ES) critical to human wellbeing is hindered by many practitioners lacking access to ES models (‘the capacity gap’) or knowledge of the accuracy of available models (‘the certainty gap’), especially in the world’s poorer regions. We developed ensembles of multiple models at an unprecedented global scale for five ES of high policy relevance. Ensembles were 2-14% more accurate than individual models. Ensemble accuracy was not correlated with proxies for research capacity – indicating accuracy is distributed equitably across the globe and that countries less able to research ES suffer no accuracy penalty. By making these ES ensembles and associated accuracy estimates freely available, we provide globally consistent ES information that can support policy and decision making in regions with low data availability or low capacity for implementing complex ES models. Thus, we hope to reduce the capacity and certainty gaps impeding local to global-scale movement towards ES sustainability

    Suunnitteluprosessiohje

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    Tämän opinnäytetyön aiheena oli suunnitteluprosessiohje. Opinnäytetyön tavoitteena oli tehdä Suomen Imurikeskus Oy:lle vakioidut toimintatavat laitteistojen suunnittelun kululle, ja selvittää mahdollinen kehitysvaihtoehto tiedonhallinnalle. Opinnäytetyössä käytiin lävitse Suomen Imurikeskus Oy:n laitteistojen valmistuksen eri vaiheita suunnittelijoiden osalta. Tämän perusteella kehitettiin vakioidut toimintatavat suunnitteluprosessiohjeeseen. Kehitysvaihtoehtona tiedonhallinnalle harkittiin Vertex Systems Oy:n Vertex Flow PDM/PLM -ohjelmistoa ja ohjelmistoon käytiin tutustumassa Vertex Systems Oy:n järjestämssä PLM-päivässä Tampereella. Lopputuloksena saatiin valmistettua Suomen Imurikeskus Oy:n käyttöön toimiva suunnitteluprosessiohje laitteistojen suunnitteluun. Suunnitteluprosessiohje sisältää ohjeistuksen laitteistojen suunnittelun eri vaiheille.The purpose of this thesis was to create engineering process manual for Suomen Imurikeskus Oy. The manual is meant to clarify the correct procedures for the process of appliance planning and alternative options for data management. In this thesis different phases of manufacturing were examined from Suomen Imurikeskus Oy’s designers point of view. Based on the thesis some standardized procedures were created for the engineering process manual. Vertex Systems' Vertex Flow PDM/PLM software was considered as an option for data management and the software was familiarized by visiting PLM-fair hosted by Vertex Systems Oy in Tampere. End result of the thesis was an engineering process manual for appliance planning to Suomen Imurikeskus Oy use. Engineering process manual includes instructions to different steps of appliance planning
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