265 research outputs found

    Operation of the photovoltaic system in Prague and data evaluation

    Get PDF
    Received: January 6th, 2021 ; Accepted: April 7th 2021 ; Published: April 12th 2021 ; Correspondence: [email protected] on-grid photovoltaic system was installed at the Faculty of Engineering in 2015. The monitoring system developed in our laboratory monitors data and can also detect failure and type of failure. The evaluation of the data shows that the amount of electricity produced slightly exceeds the expected values predicted by the internationally used internet application PVGIS. The effect of the aging of PV panels has so far had a minimal effect on the electricity produced. Immediate output power is affected by multiple parameters. Higher temperatures reduce the efficiency of energy conversion, so in summer the instantaneous power may be lower even at higher radiation intensity and smaller angle of incidence

    Design and data comparison of the photovoltaic power plants in the southern and northern hemispheres

    Get PDF
    We have recently developed a unique monitoring system for photovoltaic power plants and have gradually improved it in recent years. The system is installed at about 80 power plants in several European countries and at one power plant in Chile. We collect and evaluate all data in our laboratory. In this paper we describe the unique design of a photovoltaic power plant in the southern hemisphere in Chile with photovoltaic panels installed on tracking stands. We present the evaluated data and we discuss their comparison with photovoltaic power plants installed in Europe. We also discuss different solar conditions of these locations

    Submeter mapping of methane seeps by ROV observations and measurements at the Hikurangi Margin, New Zeeland

    Get PDF
    During R.V. Sonne cruise SO191-3, part of the "New (Zealand Cold) Vents" expedition, RCMG deployed their CHEROKEE ROV "Genesis" on the Hikurangi Margin. This accretionary margin, on the east coast of New Zealand, is related to the subduction of the Pacific Plate under the Australian Plate. Several cold seep locations as well as an extensive BSR, indicating the presence of gas hydrates, have been found at this margin. The aim of the ROV-work were to precisely localize active methane seeps, to conduct detailed visual observations of the seep structures and activity, and to perform measurements of physical properties and collect samples at and around the seep locations. The ROV allowed first ever visual observations of bubble-releasing seeps at the Hikurangi Margin. Seeps were observed at Faure Site and LM-3 in the Rock Garden area, at a flat to moderately undulating sea floor where soft sediments alternate with carbonate platforms. Bubble-releasing activity was very variable in time, with periods of almost non-activity (5 bubbles/second) alternating with periods of violent outbursts (190 bubbles/second). Bubbles sizes ranged from less than 5 mm to more than 20 mm. At Faure Site, bubble release was monitored over a period of 20 minutes, resulting in the observation of 6 outbursts, each lasting 1 minute at a 3 minute interval. These violent outbursts were accompanied by the displacement and resuspension of sediment grains and the formation of small depressions showing what is possibly an initial stage of pockmark formation. At the LM-3 site only some small bubble seeps were observed near a large carbonate platform covered by Bathymodiolus mussels, Calyptogena shells and tube worms. Sediment-temperature measurements, in both areas, were largely comparable with the bottom-water temperature except at LM-3, at a site densely populated by polychaetes, where anomalous low sediment-temperature was measured. Overall, both seep areas are very confined in space and bottom-water sampling revealed that the released methane has a microbial signature

    Star formation and gas in the minor merger UGC 10214

    Full text link
    UGC 10214 is a minor merger in which a dwarf galaxy has interacted with a large spiral galaxy \sim250 Myr ago and produced a perturbed disk and a giant tidal tail. We use a multiwavelength dataset in order to study the present and past star formation rate (SFR) and its relation to the gas and stellar mass at a spatial resolution down to 4 kpc. UGC 10214 is a very massive (stellar mass MM_{{\rm \star}} = 1.28×10111.28\times 10^{11}MM_\odot) galaxy with a low gas fraction (MgasM_{{\rm gas}}/MM_{{\rm \star}} = 0.24), a high molecular gas fraction (MH2M_{{\rm H}_2}/MHIM_{\rm HI} = 0.4) and a modest SFR (2-5 MM_\odot yr1^{-1}). The comparison of the molecular gas mass and current SFR gives a molecular gas depletion time of about \sim 2 Gyr (based on Hα\alpha), comparable to those of normal spiral galaxies. Both from a comparison of the Hα\alpha emission, tracing the current SFR, and far-ultraviolet (FUV) emission, tracing the recent SFR during the past tens of Myr, as well as from spectral energy distribution (SED) fitting with CIGALE, we find that the SFR has increased by a factor of about 2-3 during the recent past. This increase is particularly noticeable in the centre of the galaxy. A pixel-to-pixel comparison of the SFR, molecular gas mass and stellar mass shows that the central region has had a depressed FUV-traced SFR, both compared to the molecular gas and the stellar mass, whereas the Hα\alpha-traced SFR shows a normal level. The atomic and molecular gas distribution is asymmetric, but the position-velocity diagram along the major axis shows a pattern of regular rotation. We conclude that the minor merger has most likely caused variations in the SFR in the past resulting in a moderate increase of the SFR, but it has not perturbed the gas significantly so that the molecular depletion time remains normal.Comment: 17 pages, 11 figures, in press (Astronomy & Astrophysics

    Impact of Ceftolozane-Tazobactam vs. Best Alternative Therapy on Clinical Outcomes in Patients with Multidrug-Resistant and Extensively Drug-Resistant Pseudomonas aeruginosa Lower Respiratory Tract Infections

    Get PDF
    INTRODUCTION: Infections caused by multidrug-resistant (MDR), extensively drug-resistant (XDR), and difficult-to-treat (DTR) Pseudomonas aeruginosa are increasingly challenging to combat. Ceftolozane-tazobactam (C/T) is a novel β-lactam-β-lactamase inhibitor combination now commonly used to treat MDR and XDR P. aeruginosa. Lower respiratory tract infections (LRTIs) remain the most common source of infection caused by MDR/XDR P. aeruginosa. Comparative effectiveness studies to date have been limited by the type of comparator agents (i.e., aminoglycosides and polymyxins) and the inclusion of multiple infection sources (i.e., urinary tract, abdominal, skin and soft tissue, etc.). METHODS: We performed a multicenter, retrospective analysis of adults with LRTI caused by MDR or XDR P. aeruginosa admitted from January 2014 to December 2019. We aimed to compare clinical outcomes between patients who received C/T (n = 118) versus best alternative therapy (n = 88). The primary outcome was clinical failure, defined as 30-day mortality and/or an adverse drug reaction on antibiotic therapy. RESULTS: Two hundred and six patients met inclusion criteria. The C/T group had a significantly higher proportion of XDR P. aeruginosa and ventilator-associated bacterial pneumonia (VABP). After multivariable logistic regression, C/T treatment was independently associated with a 73.3% reduction in clinical failure compared to those who received best alternative therapy (P \u3c 0.001). The number needed to harm with best alternative therapy was 3. CONCLUSION: Our results suggest that C/T is a safe and effective therapeutic regimen for patients with MDR and XDR P. aeruginosa LRTI

    Comparison of polydrug use prevalences and typologies between men who have sex with men and general population men, in madrid and barcelona

    Get PDF
    Altres ajuts: Delegación del Gobierno para el Plan Nacional sobre Drogas (2019-017)This study compares the prevalence of drug use and the typologies of polydrug use (PDU) in men who have sex with men (MSM) and general population men (GPM). Participants were men aged 16-64, living in the provinces of Madrid and Barcelona: 1720 were recruited in a GPM survey, and 2658 were HIV-negative MSM from HIV/STIs diagnosis services. Lifetime and last-year prevalence of drug use and prevalence ratios (PRs) of MSM to GPM for the different drugs were calculated using Poisson regression. Latent class analysis (LCA) was performed to identify typologies of PDU. Lifetime use of the drugs considered was higher in MSM, and even higher for drug use in the last-year: PRs for cannabis, hallucinogens and cocaine ranged from 2-5; for amphetamine, ecstasy and methamphetamine 12-16; and above 60 for ketamine, GHB/GBL, inhalants and mephedrone. In the LCA for lifetime PDU four classes arose from the GPM (No-PDU (79.6%); Conventional PDU (13.8%); Intensive conventional PDU (4.9%); Heavy PDU (1.8%)) and four among MSM (No-PDU (57.7%); Conventional PDU plus poppers (18.8%); PDU preferring chemsex drugs (6.4%); Heavy PDU (17.2%)). For PDU during the last-year, three classes arose in the GPM: No-PDU (94.7%); Conventional PDU (4.3%); Heavy PDU (0.9%). For MSM, we identified four classes: No-PDU (64.7%); Conventional PDU plus poppers (15.6%); PDU preferring chemsex drugs (6.2%); Heavy PDU (13.5%). MSM should be considered a priority group for the prevention of the use of all drugs but the heterogeneity of PDU typologies regarding users' preference towards conventional and/or sexualised drugs needs to be taken into account

    Patient perspectives of managing fatigue in ankylosing spondylitis, and views on potential interventions: a qualitative study

    Get PDF
    <p>Background: Fatigue is a major component of living with ankylosing spondylitis (AS), though it has been largely over-looked, and currently there are no specific agreed management strategies.</p> <p>Methods: This qualitative exploratory study involved participants who are members of an existing population-based ankylosing spondylitis (PAS) cohort. Participants residing in South West Wales were invited to participate in a focus group to discuss; (1) effects of fatigue, (2) self-management strategies and (3) potential future interventions. The focus groups were audio-recorded and the transcripts were analysed using thematic analysis.</p> <p>Results: Participants consisted of 3 males/4 females (group 1) and 4 males/3 females (group 2), aged between 35 and 73 years (mean age 53 years). Three main themes were identified: (1) The effects of fatigue were multi-dimensional with participants expressing feelings of being ‘drained’ (physical), ‘upset’ (emotional) and experiencing ‘low-mood’ (psychological); (2) The most commonly reported self-management strategy for fatigue was a balanced combination of activity (exercise) and rest. Medication was reluctantly taken due to side-effects and worries over dependency; (3) Participants expressed a preference for psychological therapies rather than pharmacological for managing fatigue. Information on Mindfulness-Based Stress Reduction (MBSR) was received with interest, with recommendations for delivery in a group format with the option of distance-based delivery for people who were not able to attend a group course.</p> <p>Conclusions: Patients frequently try and manage their fatigue without any formal guidance or support. Our research indicates there is a need for future research to focus on psychological interventions to address the multi-faceted aspects of fatigue in AS.</p&gt

    The Enigma of Fatigue

    Full text link

    Clinical Characteristics Associated with Bacterial Bloodstream Coinfection in COVID-19

    Get PDF
    INTRODUCTION: Inappropriate antibiotic use in COVID-19 is often due to treatment of presumed bacterial coinfection. Predictive factors to distinguish COVID-19 from COVID-19 with bacterial coinfection or bloodstream infection are limited. METHODS: We conducted a retrospective cohort study of 595 COVID-19 patients admitted between March 8, 2020, and April 4, 2020, to describe factors associated with a bacterial bloodstream coinfection (BSI). The primary outcome was any characteristic associated with BSI in COVID-19, with secondary outcomes including 30-day mortality and days of antibiotic therapy (DOT) by antibiotic consumption (DOT/1000 patient-days). Variables of interest were compared between true BSI (n = 25) and all other COVID-19 cases (n = 570). A secondary comparison was performed between positive blood cultures with true BSI (n = 25) and contaminants (n = 33) on antibiotic use. RESULTS: Fever (\u3e 38 °C) (as a COVID-19 symptom) was not different between true BSI (n = 25) and all other COVID-19 patients (n = 570) (p = 0.93), although it was different as a reason for emergency department (ED) admission (p = 0.01). Neurological symptoms (ED reason or COVID-19 symptom) were significantly higher in the true BSI group (p \u3c 0.01, p \u3c 0.01) and were independently associated with true BSI (ED reason: OR = 3.27, p \u3c 0.01; COVID-19 symptom: OR = 2.69, p = 0.03) on multivariate logistic regression. High (15-19.9 × 10(9)/L) white blood cell (WBC) count at admission was also higher in the true BSI group (p \u3c 0.01) and was independently associated with true BSI (OR = 2.56, p = 0.06) though was not statistically significant. Thirty-day mortality was higher among true BSI (p \u3c 0.01). Antibiotic consumption (DOT/1000 patient-days) between true BSI and contaminants was not different (p = 0.34). True bloodstream coinfection was 4.2% (25/595) over the 28-day period. CONCLUSION: True BSI in COVID-19 was associated with neurological symptoms and nonsignificant higher WBC, and led to overall higher 30-day mortality and worse patient outcomes
    corecore