563 research outputs found

    Joint Energy and Reserve Scheduling of a Wind Power Producer in a Peer-to-Peer Mechanism

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    This paper proposes a risk constrained decision making problem for wind power producers (WPPs) in a competitive environment. In this problem, the WPP copts to maximize its likely profit whereas aggregators want to minimize their payments. So, this bi-level problem is converted to a single level one. Then, the WPP offers proper prices to the aggregators to attract them to supply their demand. Also, these aggregators can procure reserve for the WPP to compensate its uncertainties. Therefore, through a peer-to- peer (P2P) trading mechanism, the WPP requests the aggregators to allocate reserve to cover the uncertainties of the wind generation. Also, due to the presence of uncertain resources of the problem, a risk measurement tool is applied to the problem to control the uncertainties. The effectiveness of the model is assessed on realistic data from the Nordpool market and the results show that as the loads become responsive, more loads are allowed to choose their WPP to supply their load. Also, the reserve that is provided by these responsive loads to the WPP increases.©2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed

    The relation characteristics of personality of managers working in Iran University of Medical Sciences with success and desirable job

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    Background: Several studies suggest the existence of an effective relationship between individuals' characteristics and important factors such as occupational and organizational performance, job satisfaction, organizational commitment, and etc. This study was designed based on the dimensions of personality (introversion/extroversion) of managers of Iran University of Medical Sciences at three levels (executive, middle and senior) with their career success rate. Methods: This was a cross-sectional descriptive study, whose population was all managers of Iran University of Medical Sciences. To collect data, two valid and reliable questionnaires were used. The first questionnaire assessed personality characteristics of each director, and the second measured occupational success. Related tests such as Pearson correlation test and independent comparison (independent t-test) at a significance level of 0.05 were used for data analysis. Results: Findings revealed no significant relationship between variables of introversion and extroversion and occupational success among the senior managers, (p > 0.05). However, there was a direct but incomplete relationship between introversion and extroversion, which correlated with job success among middle and executives managers. Conclusion: It seems that in all three levels of managers, if the managers communicated more with employees and if the subject of communication was more of executive nature, the correlation rate would increase between extroversion and introversion with job success variables. Therefore, it is suggested to give attention to organizational interaction and communication, and contingency variables such as organization condition, structure, formality and complexity

    The ππ\pi\pi interaction in nuclear matter from a study of the π+Aπ+π±A\pi^+ A \to \pi^+ \pi^{\pm} A' reactions

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    The pion-production reactions π+Aπ+π±A\pi^+ A \to \pi^+\pi^{\pm} A' were studied on 2H^{2}H, 12C^{12}C, 40Ca^{40}Ca, and 208Pb^{208}Pb nuclei at an incident pion energy of Tπ+T_{\pi^{+}}=283 MeV. Pions were detected in coincidence using the CHAOS spectrometer. The experimental results are reduced to differential cross sections and compared to both theoretical predictions and the reaction phase space. The composite ratio C\cal CππA_{\pi\pi}^A between the π+π±\pi^{+}\pi^{\pm} invariant masses on nuclei and on the nucleon is also presented. Near the 2mπ2m_{\pi} threshold pion pairs couple to (ππ)I=J=0(\pi\pi)_{I=J=0} when produced in the π+π+π\pi^+\to \pi^+\pi^- reaction channel. There is a marked near-threshold enhancement of C\cal Cπ+πA_{\pi^+\pi^-}^A which is consistent with theoretical predictions addressing the partial restoration of chiral symmetry in nuclear matter. Furthermore, the behaviour of C\cal Cπ+πA_{\pi^+\pi^-}^A is well described when the restoration of chiral symmetry is combined with standard P-wave renormalization of pions in nuclear matter. On the other hand, nuclear matter only weakly influences C\cal Cπ+π+A_{\pi^+\pi^+}^A, which displays a flat behaviour throughout the energy range regardless of AA.Comment: 30 pages, 16 figures, PS format, accepted for publication in Nucl. Phys

    Optimization of UV-Electroproxone procedure for treatment of landfill leachate: the study of energy consumption

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    With increased population, treatment of solid waste landfill and its leachate is of major concern. Municipal landfill leachate shows variable, heterogeneous and incontrollable characteristics and contains wide range highly concentrated organic and inorganic compounds, in which hampers the application of a solo method in its treatment. Among different approaches, biological treatment can be used, however it is not effective enough to elimination all refractory organics, containing fulvic-like and humic-like substance. In this experimental study, the UV Electroperoxone process as a hybrid procedure has been employed to treat landfill leachate. The effect of various parameters such as pH, electrical current density, ozone concentration, and reaction time were optimized using central composite design (CCD). In the model fitting, the quadratic model with a P-Value less than 0.5 was suggested (< 0.0001). The R2, R2 adj, and R2 pre were determined equal to 0.98,0.96, and 0.91 respectively. Based on the software prediction, the process can remove 83 of initial COD, in the optimum condition of pH = 5.6, ozone concentration of 29.1 mg/l. min, the current density of 74.7 mA/cm2, and process time of 98.6 min. In the optimum condition, 55/33 mM H2O2 was generated through electrochemical mechanism. A combination of ozonation, photolysis and electrolysis mechanism in this hybrid process increases COD efficiency removal up 29 percent which is higher than the sum of separated mechanisms. Kinetic study also demonstrated that the UV-EPP process follows pseudo-first order kinetics (R2 = 0.99). Based on our results, the UV-EPP process can be informed as an operative technique for treatment of old landfills leachates. Graphical abstract: Figure not available: see fulltext. © 2021, The Author(s)

    Optimization of cross-section of actively bent grid shells with strength and geometric compatibility constraints

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    The use of bending as self forming process allows the realization of shape-resistant systems, such as grid shell structures. Here, a numerical method for optimisation of the cross-section of actively bent structures is introduced. For a given load distribution, the optimisation objective consists of normalizing the bending stresses to a given value on the entire structure. In addition, strength and geometric compatibility constraints are taken into account. The method is demonstrated by numerical examples. Further, in order to handle the large displacements involved, a co-rotational Finite Element formulation is adopted and modifed to take into account the changes in stiffness that occur in the forming process of active bending systems. The modified co-rotational formulation is solved for static equilibrium using a Dynamic Relaxation scheme, and is tested against the analytical solutions of some preliminary test cases, as well as experimental results, and shown to be `accurate'

    The pi -> pi pi process in nuclei and the restoration of chiral symmetry

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    The results of an extensive campaign of measurements of the pi -> pi pi process in the nucleon and nuclei at intermediate energies are presented. The measurements were motivated by the study of strong pi pi correlations in nuclei. The analysis relies on the composite ratio C_{pi pi}^A, which accounts for the clear effect of the nuclear medium on the (pi pi) system. The comparison of the C_{pi pi}^A distributions for the (pi pi)_{I=J=0} and (pi pi)_{I=0,J=2} systems to the model predictions indicates that the C_{pi pi}^A behavior in proximity of the 2m_pi threshold is explainable through the partial restoration of chiral symmetry in nuclei.Comment: accepted for publication in Nucl. Phys.

    Sputum ACE2, TMPRSS2 and FURIN gene expression in severe neutrophilic asthma

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    Background Patients with severe asthma may have a greater risk of dying from COVID-19 disease. Angiotensin converting enzyme-2 (ACE2) and the enzyme proteases, transmembrane protease serine 2 (TMPRSS2) and FURIN, are needed for viral attachment and invasion into host cells. Methods We examined microarray mRNA expression of ACE2, TMPRSS2 and FURIN in sputum, bronchial brushing and bronchial biopsies of the European U-BIOPRED cohort. Clinical parameters and molecular phenotypes, including asthma severity, sputum inflammatory cells, lung functions, oral corticosteroid (OCS) use, and transcriptomic-associated clusters, were examined in relation to gene expression levels. Results ACE2 levels were significantly increased in sputum of severe asthma compared to mild-moderate asthma. In multivariate analyses, sputum ACE2 levels were positively associated with OCS use and male gender. Sputum FURIN levels were significantly related to neutrophils (%) and the presence of severe asthma. In bronchial brushing samples, TMPRSS2 levels were positively associated with male gender and body mass index, whereas FURIN levels with male gender and blood neutrophils. In bronchial biopsies, TMPRSS2 levels were positively related to blood neutrophils. The neutrophilic molecular phenotype characterised by high inflammasome activation expressed significantly higher FURIN levels in sputum than the eosinophilic Type 2-high or the pauci-granulocytic oxidative phosphorylation phenotypes. Conclusion Levels of ACE2 and FURIN may differ by clinical or molecular phenotypes of asthma. Sputum FURIN expression levels were strongly associated with neutrophilic inflammation and with inflammasome activation. This might indicate the potential for a greater morbidity and mortality outcome from SARS-CoV-2 infection in neutrophilic severe asthma

    General properties of the pion production reaction in nuclear matter

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    The pion production reaction π+π+π±\pi^+ \to \pi^+\pi^{\pm} on 45Sc^{45}Sc was studied at incident pion energies of Tπ+T_{\pi^{+}} = 240, 260, 280, 300, and 320 MeV. The experiment was performed using the M11M11 pion-channel at TRIUMF, and multiparticle events, (π+,π+π±\pi^+,\pi^+\pi^{\pm}) and (π+,π+π±p\pi^+,\pi^+\pi^{\pm}p), were detected with the CHAOS spectrometer. Results are reported in the form of both differential and total cross sections, and are compared to theoretical predictions and the reaction phase space. The present investigation of the T-dependence of the π+Aπ+π±A\pi^+ A \to \pi^+\pi^{\pm} A' reaction complements earlier examinations of the A-dependence of the reaction, which was measured using 2H^{2}H, 4He^{4}He, 12C^{12}C, 16O^{16}O, 40Ca^{40}Ca, and 208Pb^{208}Pb targets at \sim280 MeV. Some general properties of the pion-induced pion production reaction in nuclear matter will be presented, based on the combined results of the two studies.Comment: 23 pages, Latex, accepted for publication in Nucl. Phys.
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