66 research outputs found

    Comprehensive platform for distribution transactiveenergy markets

    Get PDF
    Reducing the cost of distributed energy resources (DERs) such as renewables, storage,electric vehicles and smart loads is driving their increased connection to distributionsystems. Extracting maximum benefits from DERs require liberalising distribution sys-tems by allowing: (1) a distribution transactive energy market (DTEM) operated by alocal distribution operator (LDO) and (2) peer-to-peer (P2P), peer-to-LDO (P2LDO) andTransmission-to-LDO (T2LDO) type transactions. A DTEM will bring several benefitssuch as: (1) enhanced economic opportunity for DERs, making them more profitable and(2) increased social welfare benefiting both buyers and sellers. To achieve this objective, wedevelop a comprehensive three-phase DTEM platform that provides maximum economicopportunities for DERs and maximises social welfare that benefits all market participants,while considering P2P, P2LDO and T2LDO transactions, for both energy and ancillaryservices. Interaction between bulk electricity market independent system operator (ISO)and LDO controlled DTEM is presented. The DTEM model is implemented as a practi-cal mixed-integer linear programming formulation that includes a network reconfigurationfeature. The DTEM model is studied on three-phase 5-bus and 34-bus systems, demon-strating its effectiveness to settle energy and ancillary service transactions, while obtainingdistribution locational marginal prices. Results show that P2P transactions, when allowed,increase social welfare and increases profitability of DER

    Phenothiazine-functionalized redox polymers for a new cathode-active material

    Get PDF

    Capacity Market for Distribution System Operator – with Reliability Transactions – Considering Critical Loads and Microgrids

    Get PDF
    Conventional distribution system (DS) asset planning methods consider energy only from transmission systems (TS) and not from distributed energy resources (DER), leading to expensive plans. Newer transactive energy DS (TEDS) asset planning models, built on capacity market mechanisms, consider energy from both TS and DERs, leading to lower-cost plans and maximizing social welfare. However, in both methods the cost of higher reliability requirements for some users are socialized across all users, leading to lower social welfare. In this paper, a novel transactive energy capacity market (TECM) model is proposed for DS asset planning. It builds on TEDS incremental capacity auction models by provisioning for critical loads to bid and receive superior reliability as a service. The TECM model considers these reliability transactions, in addition, to selling energy transactions from TS and DERs, buying energy transactions from loads, and asset upgrade transactions from the network operator. The TECM model allows for islanded microgrids and network reconfiguration to maximize social welfare. The TECM model is assessed on several case studies, demonstrating that it achieves higher social welfare and a lower plan cost

    Infrared spectroscopy of asymptotic giant branch stars in the Galactic bulge

    Get PDF
    We have selected a homogeneous sample of asymptotic giant branch (AGB) stars in theGalactic bulge population from the ISOGAL survey. Our target stars cover a wide range of mass-loss rates (~10-8-10-4 M⊙ yr-1) and differ primarily by their age on the AG

    Antibacterial Strategies from the Sea: Polymer-Bound Cl-Catechols for Prevention of Biofilm Formation

    Get PDF
    Inspired by the amino acid 2-chloro-4,5-dihydroxyphenylalanine (Cl-DOPA), present in the composition of the proteinaceous glue of the sandcastle worm Phragmatopoma californica, a simple strategy is presented to confer antifouling properties to polymer surfaces using (but not releasing) a bioinspired biocide. Cl-Dopamine is used to functionalize polymer materials and hydrogel films easily, to prevent biofilm formation on themThe authors thank Uwe Rietzler from the Max-Planck-Institut für Polymerforschung for the SFM-based thickness measurements

    One life ends, another begins: Management of a brain-dead pregnant mother - A systematic review -

    Get PDF
    Background: An accident or a catastrophic disease may occasionally lead to brain death (BD) during pregnancy. Management of brain-dead pregnant patients needs to follow special strategies to support the mother in a way that she can deliver a viable and healthy child and, whenever possible, also be an organ donor. This review discusses the management of brain-dead mothers and gives an overview of recommendations concerning the organ supporting therapy. Methods: To obtain information on brain-dead pregnant women, we performed a systematic review of Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). The collected data included the age of the mother, the cause of brain death, maternal medical complications, gestational age at BD, duration of extended life support, gestational age at delivery, indication of delivery, neonatal outcome, organ donation of the mothers and patient and graft outcome. Results: In our search of the literature, we found 30 cases reported between1982 and 2010. A nontraumatic brain injury was the cause of BD in 26 of 30 mothers. The maternal mean age at the time of BD was 26.5 years. The mean gestational age at the time of BD and the mean gestational age at delivery were 22 and 29.5 weeks, respectively. Twelve viable infants were born and survived the neonatal period. Conclusion: The management of a brain-dead pregnant woman requires a multidisciplinary team which should follow available standards, guidelines and recommendations both for a nontraumatic therapy of the fetus and for an organ-preserving treatment of the potential donor

    Infrared spectroscopy of asymptotic giant branch stars in the Galactic bulge

    Get PDF
    We have selected a homogeneous sample of asymptotic giant branch (AGB) stars in the Galactic bulge population from the ISOGAL survey. Our target stars cover a wide range of mass-loss rates (∼10−8-10−4 M⊙ yr−1) and differ primarily by their age on the AGB. This homogeneous sample is thus ideally suited to study the dust formation process as a function of age on the AGB. We observed our sample with Spitzer-Infrared Spectrograph, and studied the overall properties of the infrared spectra of these targets. The analysis is complicated by the presence of strong and variable background emission, and the extracted infrared AGB star spectra are affected by interstellar extinction. Several stars in our sample have no detectable dust emission, and we used these ‘naked stars’ to characterize the stellar and molecular contributions to the infrared spectra of our target stars. The resulting dust spectra of our targets do indeed show significant variety in their spectral appearance, pointing to differing dust compositions for the targets. We classify the spectra based on the shape of their 10-μm emission following the scheme by Sloan & Price. We find that the early silicate emission classes associated with oxide dust are generally under-represented in our sample due to extinction effects. We also find a weak 13-μm dust feature in two of our otherwise naked star spectra, suggesting that the carrier of this feature could potentially be the first condensate in the sequence of dust condensation
    corecore