125 research outputs found

    Non-equilibrium thermodynamics of the spin Seebeck and spin Peltier effects

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    We study the problem of magnetization and heat currents and their associated thermodynamic forces in a magnetic system by focusing on the magnetization transport in ferromagnetic insulators like YIG. The resulting theory is applied to the longitudinal spin Seebeck and the spin Peltier effects. By focusing on the specific geometry with one YIG layer and one Pt layer, we obtain the optimal conditions for generating large magnetization currents into Pt or large temperature effects in YIG. The theoretical predictions are compared with experiments from the literature permitting to derive the values of the thermomagnetic coefficients of YIG: the magnetization diffusion length lM0.4μl_M \sim 0.4 \, \mum and the absolute thermomagnetic power coefficient ϵM102\epsilon_M \sim 10^{-2} TK1^{-1}.Comment: accepted for publication on Physical Review

    Non-equilibrium thermodynamics of the longitudinal spin Seebeck effect

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    In this paper we employ non equilibrium thermodynamics of fluxes and forces to describe magnetization and heat transport. By the theory we are able to identify the thermodynamic driving force of the magnetization current as the gradient of the effective field H\nabla H^*. This definition permits to define the spin Seebeck coefficient ϵM\epsilon_M which relates H\nabla H^* and the temperature gradient T\nabla T. By applying the theory to the geometry of the longitudinal spin Seebeck effect we are able to obtain the optimal conditions for generating large magnetization currents. Furthermore, by using the results of recent experiments, we obtain an order of magnitude for the value of ϵM102\epsilon_{M} \sim 10^{-2} TK1^{-1} for yttrium iron garnet (Y3_3Fe5_5O12_{12}).Comment: accepted for publication on Physics Procedi

    Inter-Municipal Methodology for Climate Transition Strategies : The First Case in Italy

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    To build resilient and climate-neutral cities, it is required to modify current territorial planning processes to make them more sustainable and virtuous. However, the implementation of new strategies and innovative governance models faces multiple obstacles, economic restrictions, and technical gaps. In particular, local governments often find it difficult to build structured transition processes. This article investigates how it is possible to respond effectively to the need of urban contexts to adapt to climate impacts, analyzing the case of the Climate Transition Strategy (CTS) “La Brianza Cambia Clima”, the first in Italy of this kind. Through the technical framework and the methodology described, the CTS can activate inter-municipal transformative actions through the mainstreaming of planning tools, the construction of a medium-long-term vision, and the identification of concrete and widespread actions to be implemented in the territory. This coordinated and shared strategic approach allows one to give stability, coherence, and continuity to adaptation processes involving different stakeholders and sectors of the Public Administration. Finally, it favors the implementation of multidisciplinary policies for territorial resilience on a large scale

    Non-equilibrium Thermodynamics of the Longitudinal Spin Seebeck Effect

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    In this paper we employ non equilibrium thermodynamics of fluxes and forces to describe magnetization and heat transport. By the theory we are able to identify the thermodynamic driving force of the magnetization current as the gradient of the effective field ▿H∗. This definition permits to define the spin Seebeck coefficient ϵM which relates ▿H∗ and the temperature gradient ▿T. By applying the theory to the geometry of the longitudinal spin Seebeck effect we are able to obtain the optimal conditions for generating large magnetization currents. Furthermore, by using the results of recent experiments, we obtain an order of magnitude for the value of ϵM ∼ 10-2 TK-1 for yttrium iron garnet (Y3Fe5O12)

    Addressing the Passenger Transport and Accessibility Enablers for Sustainable Development

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    Sustainable Development (SD) is a fundamental objective in the European Union (EU) and transport is considered one of the key challenges necessary to achieve it. Although transport is mostly contested from the environmental dimension, an investigation of peer-reviewed literature along with EU policy documents suggests that the transport and accessibility (T&A) criteria of infrastructure, accessibility distance, and multimodality can positively contribute to SD. However, despite this synergetic relation between T&A and SD, a practical analysis of such enablers is unknown at the regional European level. Therefore, this study investigates the Mediterranean as a study area by analyzing 79 identified passenger ports as passenger transport land-sea interaction points. Based on open access data, port infrastructure and ship accessibility, hinterland accessibility, and multimodality are evaluated as the passenger T&A enablers for SD. Comparative geo-spatial analyses are also carried out among the passenger ports\u2019 levels of enablers by using the data normalization method. These data driven comprehensive analytical results can bring added value to SD policy and planning initiatives in the Mediterranean. This study may also contribute to the development of relevant passenger port performance indicators for boosting port or regional competition and attractiveness towards SD

    Adipokines and Sexual Hormones Associated with the Components of the Metabolic Syndrome in Pharmacologically Untreated Subjects: Data from the Brisighella Heart Study

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    We evaluated the association of the sex hormone pattern and the serum level of the main adipokines to metabolic syndrome (MS) and its components in 199 pharmacologically untreated subjects. Men and women included in the age-class subgroups were matched for body mass index, waist circumference, blood pressure, heart rate, fasting plasma glucose, and plasma lipids. Men without MS had significantly lower leptin/adiponectin ratio than men with MS. Women without MS had lower leptin and leptin/adiponectin ratio than women with MS but had significantly higher adiponectin, estrone, and dehydroepiandrosterone levels. In men, the leptin/adiponectin ratio is the main factor associated to MS diagnosis (OR: 3.36, 95% CI 1.40–8.08), while in women adiponectin alone appears to be a protective factor (OR: 0.87, 95% CI 0.79–0.95). In conclusion, in a sample of pharmacologically untreated subjects, leptin/adiponectin ratio seems to be the factor more strongly associated to MS and its components

    Timeline of diagnosed pain causes in children with severe neurological impairment

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    Objective: Pain's causes in children with severe cognitive impairment may be challenging to diagnose. This study aimed to investigate if there is a relationship between pain causes and the age of children. Methods: We conducted a multicenter retrospective study in three Italian Pediatric Units. Eligible subjects were patients from 1 to 18 years with severe neurological impairment. We collected data regarding diagnoses, pain causes and medical or surgical procedures. The timing of pain episodes was categorized into age-related periods: infants and toddlers (0-24 months), preschool children (3-5 years), schoolchildren (6-12 years), and adolescents (13-17 years). Results: Eighty children with severe neurological impairment were enrolled. The mean age was 11 years (±5.8). Gastroenterological pain was most common in the first years of life (p = 0.004), while orthopaedic and tooth pain was the most typical in schoolchildren and adolescents (p = 0.001 and p = 0.02). Concerning surgical procedures, PEG placement and gastric fundoplication were significantly more common in the first 5 years of age (p = 0.03), and heart surgery was typical of infants (p = 0.04). Orthopaedic surgery was more commonly reported in older children and adolescents (p < 0.001). Conclusions: Some causes of pain are more frequent in children with severe neurological impairment in defined age-related periods. Specific age-related pain frequencies may help physicians in the diagnostic approach

    Micromagnetic simulation of electrochemically deposited Co nanowire arrays for wideband microwave applications

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    We study the magnetic properties of arrays of Co nanowires which exhibit zero bias-field ferromagnetic resonance absorptions in a 0-30 GHz range. Columnar arrays of Co nanowires with lengths of 8-15 mu m were electrochemically grown using similar to 20 mu m thick anodic alumina membranes with 50 nm pore diameters. Microstructural, static magnetic, and microwave properties of five different nanowire arrays were characterized. The studied Co nanowires present different crystal structure textures and magnetic properties. The static magnetic loop shapes and the ferromagnetic resonance frequencies of the nanowire arrays were correctly reproduced using the Mumax3 micromagnetic software. For each sample input parameters dependent on the x-ray diffraction and microstructural data, were fine-tuned to allow the best fit of the experimental hysteresis loops and the related microwave spectra. Using this method, it was possible to analyze the rather complex interplay between geometry and magneto-structural features of the different arrays, defining which parameters play a key role in the development of nano-systems with specific microwave properties
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