78 research outputs found

    A Semi-Empirical Model of PV Modules Including Manufacturing I-V Mismatch

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    This paper presents an analysis of the impact of manufacturing variability in PV modules when interconnected into a large PV panel. The key enabling technology is a compact semiempirical model, that is built solely from information derived from datasheets, without requiring extraction of electrical parameters or measurements. The model explicits the dependency of output power on those quantities that are heavily affected by variability, like short circuit current and open circuit voltage. In this way, variability can be included with Monte Carlo techniques and tuned to the desired distributions and tolerance. In the experimental results, we prove the effectiveness of the model in the analysis of the optimal interconnection of PV modules, with the goal of reducing the impact of variability

    Cost-aware design and simulation of electrical energy systems

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    One fundamental dimension in the design of an electrical energy system (EES) is the economic analysis of the possible design alternatives, in order to ensure not just the maximization of the energy output but also the return on the investment and the possible profits. Since the energy output and the economic figures of merit are intertwined, for an accurate analysis it is necessary to analyze these two aspects of the problem concurrently, in order to define effective energy management policies. This paper achieves that objective by tracking and measuring the energy efficiency and the cost effectiveness in a single modular framework. The two aspects are modeled separately, through the definition of dedicated simulation layers governed by dedicated virtual buses that elaborate and manage the information and energy flows. Both layers are simulated concurrently within the same simulation infrastructure based on SystemC-AMS, so as to recreate at runtime the mutual influence of the two aspects, while allowing the use of different discrete time scales for the two layers. Thanks to the tight coupling provided by the single simulation engine, our method enables a quick estimation of various cost metrics (net costs, annualized costs, and profits) of any configuration of EES under design, via an informed exploration of the alternatives. To prove the effectiveness of this approach, we apply the proposed strategy to two EES case studies, we explored various management strategies and the presence of different types and numbers of power sources and energy storage devices in the EES. The analysis proved to allow the identification of the optimal profitable solutions, thereby improving the standard design and simulation flow of EES

    THU0601 REFRACTORY ACUTE CORONARY SYNDROME AND CARDIOGENIC SHOCK AS ATYPICAL ONSET OF EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS

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    Background:Eosinophilic Granulomatosis with Polyangiitis (EGPA) is an ANCA-associated vasculitis, characterized by eosinophilic infiltration in tissues, intravascular and extravascular granuloma formation. It is a rare disease, affecting between 0 and 4 per million population per year. The cardiac involvement occurs in 15-60% of EGPA patients (generally ANCA-negative); it is often insidious, underestimated and it has a poor prognosis. The disease usually shows a prodromal phase characterized by asthma and allergic manifestations.Objectives:We report the case of a young patient with acute coronary syndrome (ACS) complicated by cardiogenic shock as the first manifestation of EGPA.Methods:A 36 year old Indian male patient, with a previous history of asthma, rhinitis, Raynaud syndrome and allergy to ketoprofen, presented to the emergency department with a complaint of chest pain and dyspnea. Cardiac troponin was elevated and he was admitted to intensive care unit with a diagnosis of ACS. The patient conditions rapidly deteriorated due to acute cardiogenic shock and an urgent coronary angiogram was performed. An occlusion of the left main coronary artery was treated with angioplasty and two drug-eluting stents. Echocardiography showed severe left ventricular dysfunction requiring inotropic and intra-aortic balloon pump support. A mild dermatitis after salicylic acid administration resolved with intravenous hydrocortisone 1 g. The thrombophilia screening was negative, as well as cardiovascular risk factors. Over the next days, the clinical conditions rapidly improved with recovery of normal ventricular function on discharge. However, two weeks later he was readmitted with recurrent mandibular and chest pain. Troponin levels were elevated and fluctuated, suggesting recurrent ischemic events. Repeated ECG during angina crisis showed ischemic alterations in different coronary territories. The coronary angiogram detected coronary vasospasm of the circumflex artery, reversible after nitroglycerin (Figure 1). Nitroglycerin and calcium channel blockers were initiated, but did not resolve the vasospastic angina crisis, occurring daily. Laboratory tests revealed eosinophilia (4390 cells/mcl), increased C reactive protein (9.4 mg/l) and positive antinuclear antibodies (1:320). The other serological and immunological tests were negative, including MPO-ANCA and PR3-ANCA. An abdomen and chest CT scan was negative.Figure 1.Coronary angiogram showing coronary vasospasm in the left circumflex artery (panel A, yellow arrow), reversible after nytroglicerin infusion (panel B, yellow arrow)Results:The eosinophilia and the history of asthma rose the suspect of EGPA vasculitis. The patient was treated with intravenous methylprednisolone 250 mg once daily for 3 days, followed by oral prednisone 1 mg/kg/day, with rapid and complete resolution of the recurrent angina episodes. Intravenous cyclophosphamide 10 mg/kg was administered every 2 weeks for 2 times, then 12 mg/kg every 4 weeks. Oral corticosteroid was tapered, with the persistence of a complete remission of the symptoms, after 2 months of immunosuppressive therapy.Conclusion:Coronary involvement in EGPA can mimic atherosclerotic artery disease and can be life threatening, if not promptly recognized. An accurate medical history and complete serological and immunological tests are crucial to detect an atypical onset of EGPA, prompting early immunosuppressive therapy which is pivotal for the patient survival.References:[1]MR Hazebroek et al. Prevalence and Prognostic Relevance of Cardiac Involvement in ANCA-associated Vasculitis: Eosinophilic Granulomatosis With Polyangiitis and Granulomatosis With Polyangiitis. Int J Cardiol 2015, 199: 170-9.Disclosure of Interests:None declaredDOI: 10.1136/annrheumdis-2020-eular.648

    A Cross-level Verification Methodology for Digital IPs Augmented with Embedded Timing Monitors

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    Smart systems implement the leading technology advances in the context of embedded devices. Current design methodologies are not suitable to deal with tightly interacting subsystems of different technological domains, namely analog, digital, discrete and power devices, MEMS and power sources. The interaction effects between the components and between the environment and the system must be modeled and simulated at system level to achieve high performance. Focusing on digital subsystem, additional design constraints have to be considered as a result of the integration of multi-domain subsystems in a single device. The main digital design challenges combined with those emerging from the heterogeneous nature of the whole system directly impact on performance, hence propagation delay, of the digital component. In this paper we propose a design approach to enhance the RTL model of a given digital component for the integration in smart systems, and a methodology to verify the added features at system-level. The design approach consists of ``augmenting'' the RTL model through the automatic insertion of delay sensors, which are capable of detecting and correcting timing failures. The verification methodology consists of an automatic flow of two steps. Firstly the augmented model is abstracted to system-level (i.e., SystemC TLM); secondly mutants, which are code mutations to emulate timing failures, are automatically injected into the abstracted model. Experimental results demonstrate the applicability of the proposed design and verification methodology and the effectiveness of the simulation performance

    SystemC-AMS Simulation of Energy Management of Electric Vehicles

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    Electric vehicles (EV) are rapidly invading the market, since they are clean, quiet and energy efficient. However, there are many factors that discourage EVs for current and potential customers. Among them, driving range is one of the most critical issues: running out of battery charge while driving results in serious inconvenience even comparable to vehicle breakdown, as an effect of long fuel recharging times and lack of charging facilities. As a result, the dimensioning of the energy subsystem of an EV is a crucial activity. The choice of the power components and of the adopted policies should thus be validated at design time through simulations, that estimate the vehicle driving range under reference driving profiles. It is thus necessary to build a simulation framework that takes into account an EV power consumption model, dependent on the characteristics of the vehicle and of the driving route, plus accurate models for all power components, including batteries and green power sources. The goal of this paper is to achieve early EV simulation, so that the designer can estimate at design time the driving range of the vehicle, validate the adopted components and policies and evaluate alternative configurations

    Rat strain differences in brain structure and neurochemistry in response to binge alcohol

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    RATIONALE: Ventricular enlargement is a robust phenotype of the chronically dependent alcoholic human brain, yet the mechanism of ventriculomegaly is unestablished. Heterogeneous stock Wistar rats administered binge EtOH (3 g/kg intragastrically every 8 h for 4 days to average blood alcohol levels (BALs) of 250 mg/dL) demonstrate profound but reversible ventricular enlargement and changes in brain metabolites (e.g., N-acetylaspartate (NAA) and choline-containing compounds (Cho)). OBJECTIVES: Here, alcohol-preferring (P) and alcohol-nonpreferring (NP) rats systematically bred from heterogeneous stock Wistar rats for differential alcohol drinking behavior were compared with Wistar rats to determine whether genetic divergence and consequent morphological and neurochemical variation affect the brain's response to binge EtOH treatment. METHODS: The three rat lines were dosed equivalently and approached similar BALs. Magnetic resonance imaging and spectroscopy evaluated the effects of binge EtOH on brain. RESULTS: As observed in Wistar rats, P and NP rats showed decreases in NAA. Neither P nor NP rats, however, responded to EtOH intoxication with ventricular expansion or increases in Cho levels as previously noted in Wistar rats. Increases in ventricular volume correlated with increases in Cho in Wistar rats. CONCLUSIONS: The latter finding suggests that ventricular volume expansion is related to adaptive changes in brain cell membranes in response to binge EtOH. That P and NP rats responded differently to EtOH argues for intrinsic differences in their brain cell membrane composition. Further, differential metabolite responses to EtOH administration by rat strain implicate selective genetic variation as underlying heterogeneous effects of chronic alcoholism in the human condition

    Footpad dermatitis and pain assessment in turkey poults using analgesia and objective gait analysis

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    The relationships between litter moisture, footpad dermatitis (FPD) and pain in medium-heavy turkey strains was studied by gait analysis in two medium-heavy with and without analgesia (betamethasone or bupivacaine). The relationship between FPD and litter moisture was linear above a breakpoint of 49% litter moisture, and there were no differences between the two breeds in susceptibility to FPD. Gait analysis showed higher impulse, single support time, stride time and stance time in breed A compared to breed B. Significant interactions between breed, litter and analgesic for impulse, single support time and stride time were associated with higher means for breed A given saline injection on wet litter. Data from betamethasone analgesia in Experiments 1 and 3 were combined for analysis. Peak vertical force was higher in saline- compared to betamethasone-treated birds. Compared to the wet (high FPD) litter treatments, birds on dry (low FPD) litter had greater speed and lower double support time and longer stride length. Turkeys kept on wet litter had a longer stride length compared to dry litter when given saline, whereas in betamethasone-treated birds the means were similar. There were no differences between birds with or without bupivacaine analgesia. Peak vertical force was higher in breed A than B and in birds with a low FPD compared to a high FPD score. It was concluded that breeds A and B did not differ in susceptibility to develop FPD when housed on wet litter but may have natural gait differences. Significant changes in gait parameters were associated with wet litter and with analgesic treatments. The results showed that FPD affected the gait of the turkeys and, combined with evidence of behavioural changes when given analgesia, suggest that footpad lesions are painful.</p

    Short communication : Circulating extracellular miR-22, miR-155, and miR-365 as candidate biomarkers to assess transport-related stress in turkeys

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    MicroRNA (miRNA) have been identified in circulating blood and might have the potential to be used as biomarkers for several pathophysiological conditions. To identify miRNA that are altered following stress events, turkeys (Meleagris gallopavo) were subjected to 2 h of road transportation. The expression levels of five circulating miRNA, namely miR-22, miR-155-5p, miR-181a-3p, miR-204 and miR-365-3p, were detected and assessed by quantitative polymerase chain reaction using TaqMan\uae probes, as potential biomarkers of stress. The areas under the receiver operating characteristic curves were then used to evaluate the diagnostic performance of miRNA. A panel of three stress-responsive miRNA, miR-22, miR-155 and miR-365 were identified; their expression levels were significantly higher after road transportation and the area under the curve (AUC) were 0.763, 0.71 and 0.704, respectively. Combining the three miRNA a specificity similar to the one found for the three miRNA separately was found. The AUC of the weighted average of the three miRNA was 0.763. This preliminary study suggests that the expression levels of circulating miR-22, miR-155 and miR-365 are increased during transport-related stress and that they may have diagnostic value to discriminate between stressed- and unstressed animals

    Effect of crude protein concentration and dietary electrolyte balance on litter quality, foot pad dermatitis, growth performance and processing yields in two medium heavy turkey hybrids

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    1. An experiment was conducted to investigate the effect of crude protein (CP) concentration and dietary electrolyte balance (DEB) on growth performance, processing yields, litter quality and foot pad dermatitis (FPD) in male turkeys from two commercial hybrids. Soya bean meal was replaced by vegetable protein sources selected for lower K concentrations to lower DEB in order to improve litter quality and subsequent quality of foot pads.2. Effects of CP on litter friability and wetness were not consistent during the production period. FPD in turkeys fed on diets with low CP was significantly lower than FPD in turkeys fed on diets with high CP until 84 d. Growth performance was adversely affected at low CP. Processing yields were not affected by CP.3. Litter was significantly dryer in pens of turkeys fed on diets with low DEB than in pens of turkeys fed on diets with high DEB. FPD in turkeys fed on diets with low DEB was significantly lower than in turkeys fed on diets with high DEB. Growth performance and processing yields were adversely affected at low DEB.4. FPD in turkey hybrid A was higher than in turkey hybrid B at 28 d of age. Thereafter, no differences in FPD between turkey hybrids were observed. Growth performance and processing yields were not affected by turkey hybrid.5. Overall, a significant interaction effect of CP × DEB was observed for FCR: in turkeys fed on the high DEB treatment, FCR of turkeys fed on the high CP diets was lower than FCR of turkeys fed on the low CP (LCP) diets whereas on the low DEB treatment, FCR was not affected by CP treatment.6. It was concluded that litter quality can be improved and FPD may be decreased in turkeys fed on diets containing lower CP and DEB levels.<br/
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