907 research outputs found

    Energy and economic analysis of a residential Solar Organic Rankine plant

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    To answer the actual energy, water, economic, social and environmental challenges, renewable, distributed power plants need to be developed. Among renewables, solar tri-generative power plants can be a solution where there is big low temperature heating/cooling demand and small electricity demand, like many residential and industrial utilities. In this case, solar thermal plants can produce thermal energy with low cost and high efficiency. The higher temperature heat not needed by the user can be exploited via Organic Rankine Cycle to produce electrical energy and desalinized water via reverse osmosis. The present paper analyses, via TRNSYS simulation, a system composed of 50 m2 of CPC solar thermal collectors, 3 m3 of thermal storage, a synthetic heat transfer fluid, 3 kWe ORC, 8 kWth absorber, 200 l/h direct reverse osmosis desalination device. The system is able to produce power, heating/cooling and fresh water needs for a residential house. Although system’s components are well known technologies, the integration to a efficient and economic working system is still a challenge. Global energy and economic analyses have been performed. Low temperature heating/cooling terminals allow to increase not only the use of thermal energy but also the ORCand absorber efficiency. ORC-Absorber configuration and relative fluids and temperatures are central. Government support and/or cost reduction of 30% are necessary to have positive NPV and acceptable PBT and IR

    Cephalopod diversity and ecology

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    Chiral spin currents and spectroscopically accessible single merons in quantum dots

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    We provide unambiguous theoretical evidence for the formation of correlation-induced isolated merons in rotationally-symmetric quantum dots. Our calculations rely on neither the lowest-Landau-level approximation, nor on the maximum-density-droplet approximation, nor on the existence of a spin-polarized state. For experimentally accessible system parameters, unbound merons condense in the ground state at magnetic fields as low as B∗=0.2B^* = 0.2 T and for as few as N = 3 confined fermions. The four-fold degenerate ground-state at B∗B^* corresponds to four orthogonal merons ∣QC⟩\ket{QC} characterized by their topological chirality CC and charge QQ. This degeneracy is lifted by the Rashba and Dresselhaus spin-orbit interaction, which we include perturbatively, yielding spectroscopic accessibility to individual merons. We further derive a closed-form expression for the topological chirality in the form of a chiral spin current and use it to both characterize our states and predict the existence of other topological textures in other regions of phase space, for example, at N=5. Finally, we compare the spin textures of our numerically exact meron states to ansatz wave-functions of merons in quantum Hall droplets and find that the ansatz qualitatively describes the meron states.Comment: 4 pages, 5 figures; minor title change, typos fixe

    Exploring the role of fallopian ciliated cells in the pathogenesis of high-grade serous ovarian cancer

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    High-grade serous epithelial ovarian cancer (HGSOC) is the fifth leading cause of cancer death in women and the first among gynecological malignancies. Despite an initial response to standard chemotherapy, most HGSOC patients relapse. To improve treatment options, we must continue investigating tumor biology. Tumor characteristics (e.g., risk factors and epidemiology) are valuable clues to accomplish this task. The two most frequent risk factors for HGSOC are the lifetime number of ovulations, which is associated with increased oxidative stress in the pelvic area caused by ovulation fluid, and a positive family history due to genetic factors. In the attempt to identify novel genetic factors (i.e., genes) associated with HGSOC, we observed that several genes in linkage with HGSOC are expressed in the ciliated cells of the fallopian tube. This finding made us hypothesize that ciliated cells, despite not being the cell of origin for HGSOC, may take part in HGSOC tumor initiation. Specifically, malfunction of the ciliary beat impairs the laminar fluid flow above the fallopian tube epithelia, thus likely reducing the clearance of oxidative stress caused by follicular fluid. Herein, we review the up-to-date findings dealing with HGSOC predisposition with the hypothesis that fallopian ciliated cells take part in HGSOC onset. Finally, we review the up-to-date literature concerning genes that are located in genomic loci associated with epithelial ovarian cancer (EOC) predisposition that are expressed by the fallopian ciliated cells

    Cephalopod ecology

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    Quantum phase slips in superconducting Nb nanowire networks deposited on self-assembled Si templates

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    Robust porous silicon substrates were employed for generating interconnected networks of superconducting ultrathin Nb nanowires. Scanning electron microscopy analysis was performed to investigate the morphology of the samples, which constitute of polycrystalline single wires with grain size of about 10 nm. The samples exhibit nonzero resistance over a broad temperature range below the critical temperature, fingerprint of phase slippage processes. The transport data are satisfactory reproduced by models describing both thermal and quantum fluctuations of the superconducting order parameter in thin homogeneous superconducting wires.Comment: accepted for publication on Applied Physics Letter

    Respiratory epithelial adenomatoid hamartoma: Minimally invasive surgery of an endoscopic and radiological finding in maxillary sinus mimicking an inverted papilloma

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    Abstract Introduction Respiratory epithelial adenomatoid hamartoma (REAH) is a benign entity characterized by an abnormal proliferation of glandular tissue surrounded by a thick eosinophilic basement membrane within ciliated respiratory epithelium with no evidence of atypical or metaplastic changes in the squamous cells. Case report An 84 years patient, non-smoker, with in treatment hypertension and depression reported a 3-month history of progressive right nasal obstruction, mucopurulent rhinorrhea, unilateral purulent post-nasal discharge and unilateral anosmia. Endoscopy showed a polypoidal masse, with no presence of nasal polyposis. The lesion, originating from the maxillary sinus, arose from middle meatus and extended inferiority up to the inferior turbinate.During an endoscopic minimally-invasive surgical procedure, we performed the complete excision of the whole lesion, through the use of micro-instruments and debrider technology. The patient underwent regular check-up after 3, 6 and 12 months: endoscopic and radiological evaluation showed no relapse of the disease. Conclusion Although REAH is a neoplastic pathology, the intrinsic characteristics of benignity and the typical limited and non-infiltrating diffusion allow a minimally invasive and conservative surgical approach without evidence of recurrence

    Stacking order dynamic in the quasi-two-dimensional dichalcogenide 1T-TaS2_2 probed with MeV ultrafast electron diffraction

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    Transitions between different charge density wave (CDW) states in quasi-two-dimensional materials may be accompanied also by changes in the inter-layer stacking of the CDW. Using MeV ultrafast electron diffraction, the out-of-plane stacking order dynamics in the quasi-two-dimensional dichalcogenide 1T-TaS2_2 is investigated for the first time. From the intensity of the CDW satellites aligned around the commensurate ll = 1/6 characteristic stacking order, it is found out that this phase disappears with a 0.5 ps time constant. Simultaneously, in the same experiment, the emergence of the incommensurate phase, with a slightly slower 2.0 ps time constant, is determined from the intensity of the CDW satellites aligned around the incommensurate ll = 1/3 characteristic stacking order. These results might be of relevance in understanding the metallic character of the laser-induced metastable "hidden" state recently discovered in this compound
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