318 research outputs found

    A Nature-Inspired Algorithm to Enable the E-Mobility Participation in the Ancillary Service Market

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    In the present paper, a tool is proposed to optimally schedule the charging requests of a fleet of carsharing Electric Vehicles (EVs) in an urban area, to enable their participation in the Ancillary Service Market. The centralized scheduler minimizes the imbalance of an EV fleet with respect to the power commitment declared in the Day-Ahead Market, providing also tertiary reserve and power balance control to the grid. The regulation is carried out by optimizing the initial charging time of each vehicle, according to a deadline set by the carsharing operator. To this purpose, a nature-inspired optimization is adopted, implementing innovative hybridizations of the Artificial Bee Colony algorithm. The e-mobility usage is simulated through a topology-aware stochastic model based on carsharing usage in Milan (Italy) and the Ancillary Services requests are modeled by real data from the Italian electricity market. The numerical simulations performed confirmed the effectiveness of the approach in identifying a suitable schedule for the charging requests of a large EV fleet (up to 3200 units), with acceptable computational effort. The benefits on the economic sustainability of the E-carsharing fleet given by the participation in the electricity market are also confirmed by an extensive sensitivity analysis

    Matrix Models for Supersymmetric Chern-Simons Theories with an ADE Classification

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    We consider N=3 supersymmetric Chern-Simons (CS) theories that contain product U(N) gauge groups and bifundamental matter fields. Using the matrix model of Kapustin, Willett and Yaakov, we examine the Euclidean partition function of these theories on an S^3 in the large N limit. We show that the only such CS theories for which the long range forces between the eigenvalues cancel have quivers which are in one-to-one correspondence with the simply laced affine Dynkin diagrams. As the A_n series was studied in detail before, in this paper we compute the partition function for the D_4 quiver. The D_4 example gives further evidence for a conjecture that the saddle point eigenvalue distribution is determined by the distribution of gauge invariant chiral operators. We also see that the partition function is invariant under a generalized Seiberg duality for CS theories.Comment: 20 pages, 3 figures; v2 refs added; v3 conventions in figure 3 altered, version to appear in JHE

    Opening of Ancillary Service Markets to Distributed Energy Resources: A Review

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    Electric power systems are moving toward more decentralized models, where energy generation is performed by small and distributed power plants, often from renewables. With the gradual phase out from fossil fuels, however, Distribution Energy Resources (DERs) are expected to take over in the provision of all regulation services required to operate the grid. To this purpose, the opening of national Ancillary Service Markets (ASMs) to DERs is considered an essential passage. In order to allow this transition to happen, current opportunities and barriers to market participation of DERs must be clearly identified. In this work, a comprehensive review is provided of the state-of-the-art of research on DER integration into ASMs. The topic at hand is analyzed from different perspectives. First, the current situation and main trends regarding the reformation processes of national ASMs are analyzed to get a clear picture of the evolutions expected and adjustment required in the future, according to the scientific community. Then, the focus is moved to the strategies to be adopted by aggregators for the effective control and coordination of DERs, exploring the challenges posed by the uncertainties affecting the problem. Coordination schemes between transmission and distribution system operators, and the implications on the grid infrastructure operation and planning, are also investigated. Finally, the review deepens the control capabilities required for DER technologies to perform the needed control actions

    The microbiota of the bilio-pancreatic system: A cohort, STROBE-compliant study

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    Background: The gut microbiota play an essential role in protecting the host against pathogenic microorganisms by modulating immunity and regulating metabolic processes. In response to environmental factors, microbes can hugely alter their metabolism. These factors can substantially impact the host and have potential pathologic implications. Particularly pathogenic microorganisms colonizing pancreas and biliary tract tissues may be involved in chronic inflammation and cancer evolution. Purpose: To evaluate the effect of bile microbiota on survival in patients with pancreas and biliary tract disease (PBD). Patients and Methods: We investigated 152 Italian patients with cholelithiasis (CHL), cholangitis (CHA), cholangiocarcinoma (CCA), gallbladder carcinoma (GBC), pancreas head carcinoma (PHC), ampullary carcinoma (ACA), and chronic pancreatitis (CHP). Demographics, bile cultures, therapy, and survival rates were analyzed in cohorts (T1 death <6 months; T2 death <12 months; T3 death <18 months, T3S alive at 18 months). Results: The most common bacteria in T1 were E. coli, K. pneumoniae, andP. aeruginosa. In T2, the most common bacteria were E. coli and P. aeruginosa. InT3, there were no significant bacteria isolated, while in T3S the most common bacteria were like those found in T1. E. coli and K. pneumoniae were positive predictors of survival for PHC and ACA, respectively. E. coli, K. pneumoniae, andP. aeruginosa showed a high percentage of resistant bacteria to 3CGS, aminoglycosides class, and quinolone group especially at T1 and T2 in cancer patients. Conclusions: An unprecedented increase of E. coli in bile leads to a decrease in survival. We suggest that some strains isolated in bile samples may be considered within the group of risk factors in carcinogenesis and/or progression of hepato-biliary malignancy. A better understanding of bile microbiota in patients with PBD should lead to a multifaceted approach to rapidly detect and treat pathogens before patients enter the surgical setting in tandem with the implementation of the infection control policy

    The ABCDEF's of Matrix Models for Supersymmetric Chern-Simons Theories

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    We consider N = 3 supersymmetric Chern-Simons gauge theories with product unitary and orthosymplectic groups and bifundamental and fundamental fields. We study the partition functions on an S^3 by using the Kapustin-Willett-Yaakov matrix model. The saddlepoint equations in a large N limit lead to a constraint that the long range forces between the eigenvalues must cancel; the resulting quiver theories are of affine Dynkin type. We introduce a folding/unfolding trick which lets us, at the level of the large N matrix model, (i) map quivers with orthosymplectic groups to those with unitary groups, and (ii) obtain non-simply laced quivers from the corresponding simply laced quivers using a Z_2 outer automorphism. The brane configurations of the quivers are described in string theory and the folding/unfolding is interpreted as the addition/subtraction of orientifold and orbifold planes. We also relate the U(N) quiver theories to the affine ADE quiver matrix models with a Stieltjes-Wigert type potential, and derive the generalized Seiberg duality in 2 + 1 dimensions from Seiberg duality in 3 + 1 dimensions.Comment: 30 pages, 5 figure

    Aesthetic Alteration of Marble Surfaces Caused by Biofilm Formation: Effects of Chemical Cleaning

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    Despite the massive presence of biofilms causing aesthetic alteration to the facade of the Monza Cathedral, our team in a previous work proved that the biocolonization was not a primary damaging factor if compared to chemical-physical deterioration due to the impact of air pollution. Nonetheless, the conservators tried to remove the sessile dwelling microorganisms to reduce discolouration. In this research, two nearby sculpted leaves made of Candoglia marble were selected to study the effects of a chemical treatment combining the biocides benzalkonium chloride, hydrogen peroxide and Algophase\uae and mechanical cleaning procedures. One leaf was cleaned with the biocides and mechanically, and the other was left untreated as control. The impact of the treatment was investigated after 1 month from the cleaning by digital microscopy, environmental scanning electron microscopy, confocal microscopy and molecular methods to determine the composition and the functional profiles of the bacterial communities. Despite the acceptable aesthetic results obtained, the overall cleaning treatment was only partially effective in removing the biofilm from the colonized surfaces and, therefore, not adequately suitable for the specific substrate. Furthermore, the cleaning process selected microorganisms potentially more resistant to biocides so that the efficacy of future re-treatment by antimicrobial agents could be negatively affected

    Muscle degeneration in inguinal hernia specimens.

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    There are few articles in the literature reporting the histological changes of groin structures affected by inguinal hernia. A deeper knowledge of this matter could represent an important step forward in the identification of the causes of hernia protrusion. This study aimed to recognise the pathological modifications of muscular structures in autopsy specimens excised from tissues surrounding the hernia orifice. METHODS: Inguinal hernia was identified in 30 autopsied cadavers, which presented different varieties of hernia, including indirect, direct and mixed. Tissue specimens were resected for histological study from structures of the inguinal area surrounding the hernia opening, following a standardised procedure. The histological examination was focussed on the detection of structural changes in the muscle tissues. The results were compared with biopsy specimens resected from corresponding sites of the inguinal region in a control group of 15 fresh cadavers without hernia. RESULTS: Significant modification of the muscular arrangement of the inguinal area was recognized. Pathological alterations such as atrophy, hyaline and fibrotic degeneration, as well as fatty dystrophy of the myocytes were detected. These findings were observed consistently in the context of multistructural damage also involving vessels and nerves. In cadavers with hernia these alterations were always present independent of hernia type. No comparable damage was found in control cadavers without hernia. CONCLUSIONS: The high degree of degenerative changes in the muscle fibres in the inguinal area involved in hernia protrusion described in this report seems to be consistent with chronic compressive damage. These alterations could embody one important factor among the multifactorial sources of hernia genesis. Conjectures concerning its impact on the physiology and biodynamics of the inguinal region are made. The relationship between the depicted degenerative injuries and the genesis of inguinal hernia is also a focus of discussion in this article

    Feeding the brain: the importance of nutrients for brain functions and health

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    \u2018We are what we eat\u2019, said the philosopher Feuerbach. In fact, the quality of the food we eat affects our mind as well: the brain, which represents 2% of our body weight, consumes about 20% of the calories we eat each day. Follow a few rules could therefore help to feed properly our brain, so it works to the best of its ability. It is important to know properties of foods especially regarding their aminoacidic composition because aminoacids are components of neurotransmitters, molecules needed for brain transmission and function. It is also possible to choose specific food to prevent or support different diseases that affects nervous system

    The Large N Limit of Toric Chern-Simons Matter Theories and Their Duals

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    We compute the large N limit of the localized three dimensional free energy of various field theories with known proposed AdS duals. We show that vector-like theories agree with the expected supergravity results, and with the conjectured F-theorem. We also check that the large N free energy is preserved by the three dimensional Seiberg duality for general classes of vector like theories. Then we analyze the behavior of the free energy of chiral-like theories by applying a new proposal. The proposal is based on the restoration of a discrete symmetry on the free energy before the extremization. We apply this procedure at strong coupling in some examples and we discuss the results. We conclude the paper by proposing an alternative geometrical expression for the free energy.Comment: 40 pages, 7 figures, using jheppub.sty, references adde

    Gemcitabine and oxaliplatin combination chemotherapy in advanced biliary tract cancers

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    BACKGROUND: Biliary tract cancers are uncommon tumors with a poor prognosis and most patients present with invasive and inoperable disease at diagnosis. Chemotherapy represents a palliative treatment, with poor response rates and a median survival of less than 6 months. Oxaliplatin and gemcitabine have shown an interesting activity as single agents in this group of patients. PATIENTS AND METHODS: We carried out a multicenter phase II study to evaluate the efficacy and safety of combined oxaliplatin and gemcitabine in locally advanced and metastatic biliary tract carcinoma. The schedule of chemotherapy included oxaliplatin 100 mg/m(2) on day 1 and gemcitabine 1000 mg/m(2) on days 1 and 8, every 21 days. RESULTS: All the 24 patients were evaluable for response and toxicity. According to RECIST criteria we observed one complete response and 11 partial responses for an overall response rate of 50%. Overall survival for all the patients on study was 12 months (range 2-30). According to WHO criteria, three patients (12.5%) suffered grade 3 neutropenia and three patients (12.5%) grade 3 thrombocytopenia. Only two patients (8%) suffered grade 3 neuropathy. CONCLUSIONS: Oxaliplatin and gemcitabine chemotherapy seems to be effective with a favorable safety profile in first-line chemotherapy of advanced biliary tract cancers
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