746 research outputs found

    On Relaxing Metric Information in Linear Temporal Logic

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    Metric LTL formulas rely on the next operator to encode time distances, whereas qualitative LTL formulas use only the until operator. This paper shows how to transform any metric LTL formula M into a qualitative formula Q, such that Q is satisfiable if and only if M is satisfiable over words with variability bounded with respect to the largest distances used in M (i.e., occurrences of next), but the size of Q is independent of such distances. Besides the theoretical interest, this result can help simplify the verification of systems with time-granularity heterogeneity, where large distances are required to express the coarse-grain dynamics in terms of fine-grain time units.Comment: Minor change

    Living with stable angina: patients' pathway and needs in angina.

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    AIMS: There is evidence that stable angina patients may suffer from emotional disorders that further impair their quality of life. However, the emotional experience of living with stable angina from the patient's perspective still has to be explored. Thus, the main aim of this study was to explore patients' emotional experience of having stable angina and their reported needs during the pathway from the first symptoms, through the process of diagnosis, to management and related lifestyle changes. METHODS: A survey was conducted in 75 chronic ischemic heart disease patients with angina (Brazil, China, Romania, Russia, and Turkey) using a 75-min, face-to-face in-depth interview. RESULTS AND CONCLUSION: Patients' responses highlighted the need to increase individuals' awareness on the first signs and symptoms of the disease. The survey also showed that chronic stable angina patients need constant emotional support to overcome stress, anxiety, and depression. Finally, this study suggests the need to offer greater space for dialogue with healthcare professionals to get more comprehensive and 'patient-friendly' information

    Physiopathological rationale of using high-flow nasal therapy in the acute and chronic setting: A narrative review

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    Chronic lung disease and admissions due to acute respiratory failure (ARF) are becoming increasingly common. Consequently, there is a growing focus on optimizing respiratory support, particularly non-invasive respiratory support, to manage these conditions. High flow nasal therapy (HFNT) is a noninvasive technique where humidified and heated gas is delivered through the nose to the airways via small dedicated nasal prongs at flows that are higher than the rates usually applied during conventional oxygen therapy. HFNT enables to deliver different inspired oxygen fractions ranging from 0.21 to 1. Despite having only recently become available, the use of HFNT in the adult population is quite widespread in several clinical settings. The respiratory effects of HNFT in patients with respiratory failure may be particularly relevant for clinicians. In this narrative review, we discuss the main pathophysiological mechanism and rationale for using HFNT in the acute and chronic setting

    levelized cost of energy lcoe analysis of a low temperature pcm thermal storage combined with a micro chp in an apartment block

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    Abstract When Combined Heat and Power (CHP) is applied to the building sector the main driver for the right sizing is the thermal load. The wide range of hourly and daily heating need variations in dwellings represent a key aspect to get the device cost effectiveness and self-sustainability. For those purposes thermal energy storage can be coupled so as to minimize the energy generation cost as much as possible. Furthermore, estimating the cost effectiveness and technical feasibility of a cogeneration plant with a domestic target is very challenging and it should be done only if a comprehensive loads evaluation along with a real cost analysis have been performed. The purpose of the research is to analyze the correct interaction between the CHP using a domestic load and a thermal storage analyzing the differences between classic water storage and one with better performance in PCM. The case study is an apartment block located in Rome, Italy. Moreover, the economic characteristics will be studied by the calculation of the Levelized Cost Of Energy (LCOE) along with the capital costs and the actual technical problems arising from the thermal energy accumulation. PCM (phase change materials) is demonstrated to have a potential wide use since it is more practical, in terms of required technical spaces, especially in constrained environments such as existing buildings

    Economic Analysis and Technical Issues of Low Temperature PCM Thermal Storage Combined with a Condensing Micro-CHP

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    Abstract This study is focused on showing technical and economic issues related to the use of low temperature PCM (Phase Change Material) storage system coupled to a condensing micro CHP. That one is a single cylinder engine of rated power and thermal outputs equal to 5 kW and 13.1 kW respectively, equipped with a three-way catalyst to meet the regulations on pollutants emission. Two different system layouts were built and economical-environmental performance was evaluated. Specifically, a traditional water tank and a PCMs array were analysed. A two-family house characterized by a normalized primary energy need equal to 50.523 kWh/m2 y was assumed as the end user. That energy need is referred to the climatic conditions typical of Middle region in Italy. Finally, the LCOE (Levelised Cost of Electricity), calculated over a system lifespan of 15 years, has been chosen as the main indicator to compare the different options optimizing the CHP switching-on strategies

    Short-term physiological plasticity.Trade-off between drought and recovery responses in three Mediterranean cistus species

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    Short-term physiological plasticity allows plants to thrive in highly variable environments such as the Mediterranean ecosystems. In such context, plants that maximize physiological performance under favorable conditions, such as Cistus spp., are generally reported to have a great cost in terms of plasticity (i.e., a high short-term physiological plasticity) due to the severe reduction of physiological performance when stress factors occur. However, Cistus spp. also show a noticeable resilience ability in response to stress factors. We hypothesized that in Cistus species the short-term physiological response to stress and that to subsequent recovery can show a positive trade-off to offset the costs of the photosynthetic decline under drought. Gas exchange, chlorophyll fluorescence, and water relations were measured in C. salvifolius, C. monspeliensis, and C. creticus subsp. eriocephalus during an imposed experimental drought and subsequent recovery. Plants were grown outdoor in common garden conditions from seeds of different provenances. The short-term physiological response to stress and that to recovery were quantified via phenotypic plasticity index (PIstress and PIrecovery, respectively). A linear regression analysis was used to identify the hypothesized trade-off PIstress-PIrecovery. Accordingly, we found a positive trade-off between PIstress and PIrecovery, which was consistent across species and provenances. This result contributes in explaining the profit, more than the cost, of a higher physiological plasticity in response to short-term stress imposition for Cistus spp because the costs of a higher PIstress are payed back by an as much higher PIrecovery. The absence of leaf shedding during short-term drought supports this view. The trade-off well described the relative variations of gas exchange and water relation parameters. Moreover, the results were in accordance with the ecology of this species and provide the first evidence of a consistent trade-off between the short-term physiological responses to drought and recovery phases in Mediterranean species

    Renal function, electrolytes, and congestion monitoring in heart failure.

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    Congestion, renal function, and electrolyte imbalance (particularly potassium) are common problems in the management of the complex multi-morbid patient with heart failure (HF). Poor control of these fundamental clinical features is associated with adverse outcomes. Close monitoring of serum potassium and renal function is recommended by most current guidelines during the management of an episode of acute decompensated HF, yet the recommendations remain poorly implemented. Physicians are advised to treat a state of euvolaemia after an admission with decompensated HF and residual congestion is a marker of worse outcome, yet control of congestion is poorly assessed and managed in real-world practice. This document reflects the key points discussed by a panel of experts during a Heart Failure Association meeting on physiological monitoring of the complex multi-morbid HF patient, and here, we present to aspects related to renal function, electrolyte, and congestion monitoring
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