1,204 research outputs found
Ride Sharing with a Vehicle of Unlimited Capacity
A ride sharing problem is considered where we are given a graph, whose edges are equipped with a travel cost, plus a set of objects, each associated with a transportation request given by a pair of origin and destination nodes. A vehicle travels through the graph, carrying each object from its origin to its destination without any bound on the number of objects that can be simultaneously transported. The vehicle starts and terminates its ride at given nodes, and the goal is to compute a minimum-cost ride satisfying all requests. This ride sharing problem is shown to be tractable on paths by designing a O(h*log(h)+n) algorithm, with h being the number of distinct requests and with n being the number of nodes in the path. The algorithm is then used as a subroutine to efficiently solve instances defined over cycles, hence covering all graphs with maximum degree 2. This traces the frontier of tractability, since NP-hard instances are exhibited over trees whose maximum degree is 3
A coupled thermal and electrochemical study of lithium-ion battery cooled by paraffin/porous-graphite-matrix composite
Lithium-ion (Li-ion) battery cooling using a phase change material (PCM)/compressed expanded natural graphite (CENG) composite is investigated, for a cylindrical battery cell and for a battery module scale. An electrochemistry model (average model) is coupled to the thermal model, with the addition of a one-dimensional model for the solution and solid diffusion using the nodal network method. The analysis of the temperature distribution of the battery module scale has shown that a two-dimensional model is sufficient to describe the transient temperature rise. In consequence, a two-dimensional cell-centred finite volume code for unstructured meshes is developed with additions of the electrochemistry and phase change. This two-dimensional thermal model is used to investigate a new and usual battery module configurations cooled by PCM/CENG at different discharge rates. The comparison of both configurations with a constant source term and heat generation based on the electrochemistry model showed the superiority of the new design. In this study, comparisons between the predictions from different analytical and computational tools as well as open-source packages were carried out, and close agreements have been observed
Theoretical development and characterisation of a Josephson Traveling Wave Parametric Amplifier for very low power microwave signals
L'abstract è presente nell'allegato / the abstract is in the attachmen
The potential role of G-CSF in stroke
O fator estimulador de colônias granulocitárias (G-CSF) é uma glicoproteína descrita há mais de vinte anos, e é largamente utilizada para tratamento de estados neutropênicos e no transplante de medula óssea. O G-CSF estimula células-tronco hematopoéticas e regula crucialmente a sobrevivência de neutrófilos maduros, pós-mitóticos, através da inibição da apoptose. Além do efeito sistêmico, mais recentemente tem-se demonstrado uma surpreendente atividade do G-CSF no sistema nervoso central. A administração de G-CSF mobiliza células-tronco e progenitoras da medula óssea para o sangue periférico, que, por sua vez, atravessa a barreira hemato-encefálica (BHE) e se dirige à área acometida do cérebro. A atividade do G-CSF no sistema nervoso central tem sido caracterizada como multimodal, pois, além do efeito mobilizador de células da medula óssea, demonstrou uma ação direta neuroprotetora através de diferentes mecanismos, tais como a atividade antiapoptótica em neurônios, regeneração da vascularização, efeito anti-inflamatório e estimulação da neurogênese endógena. Este relato sumariza a ação do G-CSF no sistema nervoso central e aborda seu potencial para o emprego no acidente vascular cerebral.The granulocyte colony-stimulating-factor (G-CSF) is a glycoproteina which has been described for decades, and it is commonly utilized in the treatment of neutropenic states and bone marrow transplants. G-CSF stimulates hematopoietic stem-cels e crucially regulates the survival of mature neutrophils through a mechanism of apoptosis inhibition. Beyond its systemic effect, recently it has been shown its surprising activity in the central nervous system (CNS). G-CSF administration mobilizes bone marrow stem cells para systemic blood, and those cells cross the blood-brain-barrier e target brain's damaged area. G-CSF's activity in the CNS has been defined as multimodal, because additionally it has been demonstrated a direct neuroprotective action through different mechanisms such as antiapoptotic activity, angiogenesis, anti-inflamatory effect, and stimulation of endogenous neurogenesis. This paper sumarizes G-CSF action in the CNS and approaches its potential para use in stroke
Condizionalità e consulenza aziendale nell'allevamento bovino, suino e ovicaprino: opportunità per il medico veterinario
Geology, petrography and U-Pb age of a NW-SE longitudinal dyke swarm from the Eastern Northpatagonian Massif, Río Negro
En esta contribución se revisan las relaciones estratigráficas y la petrografía de un enjambre de diques longitudinales de rumbo NO-SE, en un amplio sector del Macizo Nordpatagónico oriental (Río Negro). Se presenta además una edad U-Pb en circón correspondiente a la cristalización magmática de los diques. El enjambre se extiende por alrededor de 100 km de largo en dirección NO, entre Punta Pórfido y Rincón de Pailemán, y en una faja de aproximadamente 35 km de ancho. Su composición es esencialmente andesítica y traquiandesítica e internamente los diques exhiben variaciones en la distribución de sus texturas subvolcánicas, producidas por sus diferentes historias térmicas de enfriamiento. Las relaciones estratigráficas del enjambre con sus rocas de caja y un dato U-Pb circones de 243 Ma, indican que es postorogénico respecto de la deformación pérmica del ciclo Gondwánico, y anterior a la efusión de las rocas volcánicas y piroclásticas del Complejo Volcánico Marifil. Los diques se alojan a lo largo de las mismas estructuras de rumbo NO que los cuerpos intrusivos y extrusivos de dicho complejo. El enjambre tiene distribución regional en el Macizo Nordpatagónico oriental y es un episodio ígneo transicional entre el magmatismo Gondwánico y el Complejo Marifil.In this contribution we review the stratigraphic relationships and petrography of a longitudinal NW-SE dyke swarm, in a broad sector of Eastern Northpatagonian Massif (Río Negro). Also a U-Pb age on zircon is presented as the crystallization age of these dikes. The swarm extends in NW direction for about 100 km long, between Punta Pórfido and Rincón de Pailemán, and in a belt about 35 km wide. Its composition is essentially andesitic-trachyandesitic, showing internal variations of the distribution of subvolcanic textures produced by different thermal cooling histories. The stratigraphic relationships of the swarm with their host rocks and the U-Pb age of 243 Ma indicate that it belongs to a postorogenic event of the permian Gondwanic Cycle and is previous to the volcanic and pyroclastic rocks of the Marifil Volcanic Complex. The dikes are hosted in the same NW structures than the intrusive and extrusive bodies of the mentioned complex. The swarm has a regional distribution to the east of the Northpatagonian Massif and is a transitional igneous event between the permian Gondwanic magmatic activity and the Marifil Volcanic Complex.Fil: González, Santiago Nicolás. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Greco, Gerson Alan. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gonzalez, Pablo Diego. Universidad Nacional de Río Negro. Sede Alto Valle. Instituto de Investigaciones en Paleobiología y Geología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sato, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Llambias, Eduardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Varela, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Stipp Basei, Miguel Angelo. Universidade de Sao Paulo; Brasi
Superconducting Josephson-Based Metamaterials for Quantum-Limited Parametric Amplification: A Review
In the last few years, several groups have proposed and developed their own platforms demonstrating quantum-limited linear parametric amplification, with evident applications in quantum information and computation, electrical and optical metrology, radio astronomy, and basic physics concerning axion detection. Here, we propose a short review on the physics behind parametric amplification via metamaterials composed by coplanar waveguides embedding several Josephson junctions. We present and compare different schemes that exploit the nonlinearity of the Josephson current-phase relation to mix the so-called signal, idler, and pump tones. The chapter then presents and compares three different theoretical models, developed in the last few years, to predict the dynamics of these nonlinear systems in the particular case of a 4-wave mixing process and under the degenerate undepleted pump assumption. We will demonstrate that, under the same assumption, all the results are comparable in terms of amplification of the output fields
A three-year longitudinal study of healthy lifestyle behaviors and adherence to pharmacological treatments in newly diagnosed patients with acute coronary syndrome: hierarchical linear modeling analyses
Aim: Healthy lifestyle behaviors and a good adherence to pharmacological treatments are important predictors of lower recurrence rates and better overall outcomes among patients with an established acute coronary syndrome (ACS). The present study sought to investigate the longitudinal trajectories of these behaviors years after the onset of an ACS. Subject and methods: We recruited a sample of 275 newly diagnosed consecutive patients at their first ACS event (mean age: 57.1 ± 7.87 years; 84% males) admitted to a cardiac rehabilitation program from three large public hospitals in Northern Italy. Patients completed a battery of sociodemographic questionnaires, which evaluated healthy lifestyles (smoking status, alcohol intake, diet, and physical activity) and adherence to pharmacological treatments, at five time-points (pre-event, 6-, 12-, 24-, and 36-month follow-ups). Longitudinal trajectories were examined through hierarchical (generalized) linear models, controlling for several demographic and clinical variables. Results: We found significant changes in all healthy lifestyles from pre-event to the 6-month follow-up, suggesting the adoption of healthier behaviors soon after the cardiac event. However, from the 6-month up to the 3-year follow-up, patients experienced small but significant declines in their self-reported levels of healthy dietary behaviors and physical activity. Further, we found that the odds of being at medium risk of non-adherence to the pharmacological treatments significantly increased over the course of 3 years. Conclusion: Given the negative long-term trajectories in specific lifestyles and adherence to pharmacological treatments, cardiac rehabilitation programs are suggested to provide repeated psychological interventions aimed at fostering patients’ capabilities to self-regulate their habitual behaviors
Two-Phase Depth-Integrated Model for Unsteady River Flow
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Josephson diode effect in monolithic dc-SQUIDs based on 3D Dayem nanobridges
It was recently experimentally proved that the superconducting counterpart of
a diode, i.e., a device that realizes nonreciprocal Cooper pairs transport, can
be realized by breaking the spatial and time-reversal symmetry of a system
simultaneously. Here we report the theory, fabrication, and operation of a
monolithic dc superconducting quantum interference device (dc-SQUID) that
embedding three-dimensional (3D) Dayem nanobridges as weak links realizes an
efficient and magnetic flux-tunable supercurrent diode. The device is entirely
realized in Al and achieves a maximum rectification efficiency of ,
which stems from the high harmonic content of its current-to-phase relation
only without the need of any sizable screening current caused by a finite loop
inductance. Our interferometer can be easily integrated with state-of-the-art
superconducting electronics, and since it does not require a finite loop
inductance to provide large rectification its downsizing is not limited by the
geometrical constraints of the superconducting ring
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