This work aims to evaluate the effect of soiling on energy production for large-scale ground mounted photovoltaic plants in the countryside of southern Italy. Since the effect of pollution can ...seriously compromise the yield of solar parks, the results obtained in this study can help the operation and maintenance responsible in choosing the proper washing schedule and method for their plants and avoid wasting money. In order to determine the losses due to the dirt accumulated on photovoltaic modules, the performances at Standard Test Conditions (STC – Irradiance: 1000
W/m
2; Cell temperature: 25
°C; Solar spectrum: AM 1.5) of two 1
MW
p solar parks before and after a complete clean-up of their photovoltaic modules have been compared. The performances at STC of the two plants have been determined by using a well-known regression model that accepts as an input two climate data (the in-plane global irradiance and the photovoltaic module temperature), while the output results in one electrical parameter (the produced power). A regression model has been preferred to a common performance ratio analysis because this latter is too much influenced by the seasonal variation in temperature and by the plant availability. The results presented in this work show that both the soil type and the washing technique influence the losses due to the pollution. A 6.9% of losses for the plant built on a sandy soil and a 1.1% for the one built on a more compact soil have been found. Finally, these results have been used in order to compare the washing costs with the incomings due to the performance improvement.
•The soiling effect can have a significant impact on the PV plant performance.•Bayesian neural network performs better than polynomial regression model.•Grid operators can benefit from the proposed ...technique.
This paper presents a comparison between two different techniques for the determination of the effect of soiling on large scale photovoltaic plants. Four Bayesian Neural Network (BNN) models have been developed in order to calculate the performance at Standard Test Conditions (STCs) of two plants installed in Southern Italy before and after a complete clean-up of their modules. The differences between the STC power before and after the clean-up represent the losses due to the soiling effect. The results obtained with the BNN models are compared with the ones calculated with a well known regression model. Although the soiling effect can have a significant impact on the PV system performance and specific models developed are applicable only to the specific location in which the testing was conducted, this study is of great importance because it suggests a procedure to be used in order to give the necessary confidence to operation and maintenance personnel in applying the right schedule of clean-ups by making the right compromise between washing cost and losses in energy production.
Onboard NASA Terra spacecraft is one of the most sophisticated earth observing instruments ever flown, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), created as part of a ...joint project between the Japanese Ministry of Economy, Trade, and Industry and NASA. This instrument consists of three independent bore-sighted telescopes with 14 channels in the visible, near-infrared, and thermal infrared regions capable of being pointed up to 22.5° off-nadir. In addition, there is an additional backward-looking visible channel telescope for stereo-photogrammetric observations. The spatial resolutions are 15 m/pixel in the visible, 30 m/pixel in the near-IR, and 90 m/pixel at thermal wavelengths, and the swath width is 60 km. ASTER instrument offers unprecedented opportunities for observing volcanoes and their activity from low earth orbit. It is the purpose of this short paper to introduce ASTER to the volcanological community, highlight its capabilities, advantages and limitations, and to show some examples of ASTER data and related analyses. We will also explain how users can readily access ASTER data.
This paper describes a new methodology to quantify the variation in the output of a computational fluid dynamics model for block and ash flows, when the digital elevation model (DEM) of the terrain ...and other inputs are given as a range of possible values with a prescribed uncertainty. Integrating these variations in the possible flows as a function of input uncertainties provides well-defined hazard probabilities at specific locations, i.e. a hazard map. Earlier work provided a methodology for assessing hazards based on variations in flow initiation and friction parameters. This paper extends this approach to include the effect of terrain error and uncertainty. The results are based on potential flows at Mammoth Mountain, CA, and Galeras Volcano, Colombia. The analysis establishes the soundness of the approach and the effect of including the uncertainty in DEMs in the construction of probabilistic hazard maps.
The antinociceptive properties of
Casearia sylvestris Sw. (Flacourtiaceae) were investigated in various models of pain-related behavior in mice. The hydroalcoholic crude extract of the plant (30–300
...mg/kg,
per os) clearly inhibited nocifensive responses induced by ovalbumin (hindpaw licking) or acetic acid (writhes) in graded fashion. At 300
mg/kg, the extract reduced nocifensive behaviors (from 71.1
±
13.3 to 14.8
±
9.3
s; from 31.3
±
4.5 to 3.3
±
1.2 writhes, respectively) to similar extents as indomethacin (5
mg/kg; 5.7
±
1.1
s and 3.3
±
1.2 writhes, respectively). Significant antinociceptive effects in the hot plate test were only detected following administration of the highest extract dose, but this analgesic action appeared to be specific as the extract failed to change motor and exploratory activities. The antinociceptive effect of
Casearia sylvestris extract in the acetic acid test was prevented by prior treatment with the non-selective opioid receptor antagonist naloxone (1
mg/kg; 5.8
±
4.2 and 31.5
±
3.1 writhes in vehicle-treated and naloxone-treated groups, respectively), indicating that the endogenous opioid system is involved in its analgesic mechanism of action. Thus, our investigation suggests a potential therapeutic benefit of
Casearia sylvestris Sw. in treating conditions associated with inflammatory pain.
Tenerife is the central island of the Canary Archipelago (Spain), which consists of seven islands that represent different stages of geological evolution. The Teide-Pico Viejo (28° 16′ 30′′ N, 16° ...38′ 42′′ W) stratocones formed during the last eruptive phase of the isle of Tenerife. It is an active, though currently quiescent, shield volcano that last erupted in 1909 and is located on the Tenerife Island. In the framework of the European Project FP6 Prevention, Information and Early Warning (PREVIEW)-EURORISK (http://www.preview-risk.com/), a field campaign was performed on Tenerife Island on September 2007. This campaign focused on the acquisition of in situ reflectance and emissivity spectra relative to Pico de Teide and Las Cañadas Caldera. The collected spectra represented the ‘ground truth’ and have been used for the supervised classification on multispectral (Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)) and hyperspectral (Earth Observing 1 (EO1)-Hyperion) data. The first ever classification mapping carried out on the Teide Volcano by utilizing the remote-sensing method is reported in this article. The methods used to process and to classify the data are discussed, and a comparison with the existing geological maps is presented.
Thermal spaceborne remote sensing has been used to study, monitor, and forecast volcanic activity for decades. But these data have not been used systematically at high spatial resolution to study ...changes in volcano temperatures across an entire region spanning multiple decades to understand background thermal activity and its relation to unrest and eruption. We have developed a first-of-a-kind database that uses manual analysis to identify and collect data for volcanic thermal output with 90 m/pixel spatial resolution for 330 potentially active volcanoes found in Latin America between the years 2000–2017. This database is reliant on the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor due to its high spatial resolution data, capability of detecting low-level thermal features, its accessibility and reliability compared to similar data types, and the long time series available at multiple volcanoes.
A total of 88 Latin American volcanoes were found to have some type of volcanic thermal feature detected by ASTER, and here we document thermal features at 16 of these volcanoes detected from space for the first time. We have recorded these thermal features, including the temperature above background, area above background, and the timing and location of detection in the ASTER Volcanic Thermal Output Database (AVTOD). By comprehensively analyzing such a large dataset, we are able to quantitatively analyze some of the issues with these data, including 24% of all volcanoes in this study failing to meet the acquisition rates proposed by the current acquisition plan and 44.5% of all acquisitions being unusable due to interference from clouds. We provide recommendations of how to update future acquisition plans that would focus on night-time and cloud-free acquisitions. In order to confirm the validity of AVTOD it was tested against the existing Moderate Resolution Imaging Spectroradiometer (MODIS)-based MIROVA database. In some cases, we found a high degree of correlation between the two datasets (r2 = 0.87). In other cases, however, correlation was limited due to the difference in spatial resolution of these two data types. By examining the maximum temperature detected by every volcano in the database we found 46 that never reach a temperature high enough to be detected by MODIS-class thermal sensors. The information in this database provides new insights about volcanic activity both on its own, and in combination with other data types, as well as a data-driven approach to improve key features in future sensors.
•Manual analysis performed on 330 potentially active volcanoes in Latin America over 17 years.•Unrest previously undetected by satellite sources has been identified at 16 volcanoes.•The utility of measuring both temperature and area changes of thermal features in TIR data is demonstrated at Sabancaya volcano.•AVTOD data are compared against MIROVA data to establish validity.
A McDonnell‐Douglas DC‐8 NASA research aircraft inadvertently flew into an airborne volcanic ash plume from the 26 February 2000 eruption of Hekla Volcano. Filter samples from the aircraft were ...compared with “normal use” and “pristine clean” filters using SEM, energy‐dispersive x‐ray spectrometer, and Nicolet FTIR spectrophotometer analyses. These analyses confirm that the DC‐8 encountered airborne volcanic ash from Hekla Volcano. This result is supported by independent onboard heated aerosol observations at the time of the encounter. The analyses further demonstrate the ambiguous nature of the dual band thermal IR (“split window”) method for detecting volcanic ash from the point of view of aviation safety. They also highlight the utility of in situ aircraft filter‐based observations of volcanic aerosols for scientific purposes.
The simultaneous solution of the Planck equation (the so-called “dual-band” technique) for two shortwave infrared Landsat Thematic Mapper (TM) bands allows an estimate of the fractional area of the ...hottest part of an active flow and the temperature of the cooler crust. Here, the dual-band method has been applied to a time series of Mount Etna eruptions. The frequency distribution of the fractional area of the hottest component reveals specific differences between summit and flank lava flows. The shape of the density function shows a trend consistent with a Gaussian distribution and suggests a relationship between the moments of the distribution and the emplacement environment. Because flow composition of Etnean lavas generally remains constant during the duration of their emplacement, it appears that the shape of any particular frequency distribution is probably related to fluid mechanical aspects of flow emplacement that affect flow velocity and flow heat loss and thus the rate of formation of the surface crust. These factors include the influence of topographical features such as changes in slope gradient, changes in volume effusion rate, and progressive downflow increases in bulk or effective viscosity. A form of the general theoretical solution for the ‘dual-band’ system, which illustrates the relationship between radiance in TM bands 5 and 7, corresponding to hot fractional area and crust temperature, is presented. Generally speaking, it appears that for a given flow at any point in time, larger fractional areas of exposed hot material are correlated with higher temperatures and that, while the overall shape of that distribution is common for the flows studied, its amplitude and slope reflect individual flow rheological regimes.
Abstract
Introduction
ST elevation (STE) usually means acute transmural ischemia by epicardial coronary artery occlusion by a blood clot,so Guidelines recommend rapid reperfusion therapy, possibly ...within the first hour. Nevertheless,STE due to non–ischemic etiologies has been reported in up to 15% of the general population.We report a case of ‘likely STEMI’ presenting with marked STE,QTc prolongation and Brugada like pattern on ECG but no significant coronary obstruction on angiography.Case 1A 74y woman presented in the ER with syncope and chest pain.History of pulmonary emphysema and Crohn‘s disease previously operated on. On admission:apyretic,BP 80/40, HR130 bpm, SO2 98% on mask O2 12 l/min.WBC 20,000, 84% neut, high D–Dimer 36091 and HS–TnI 99. On transthoracic echo (TTE) akinesis in apical, apical lateral, anteroseptal, and anterior wall and EF 25%.On Chest CT bilateral emphysema,no pulmonary embolism.On ECG sinus tachycardia,frequent PVCs,diffuse deep negative waves and prolonged QTc.While in ER,a new she syncope occurred,and tachycardia with large complex,with spontaneous resolution,was observed.On ICU admission ECG diffuse STE with coved pattern in V1 and prolonged QTc 641 ms;treated with magnesium sulfate,calcium gluconate,metoprolol,ASA,heparin;on urgent coronary angiography subcritical stenosis of left anterior descending artery without blood clot:PCI with drug–eluting stent was performed. Nevertheless,ECG did not change while multiple ventricular fibrillations occurred later, requiring electric shock.Later on, after prolonged treatment with magnesium sulfate, Calcium gluconate, antibiotic, electrolytes correction,QTc,ECG and EF progressively normalized.
Discussion
The patient reported was labelled as a “TakoTsubo syndrome“ diagnosis,but in fact we think the ECGs (persistent STE, prolonged QTc and Brugada pattern), the TTEs and clinical features can be explained by different nosological entity due to the dysregulated INa, and in particular by increased late sodium current INa late : it leads to impaired cardiac energetics and contractile dysfunction as well as cardiac arrhythmias; acidosis and hypoxia can also increases IN late.As for our patient, unlike Takotsubo syndrome, she had no emotional trigger, no characteristic apical balloon on TTE, while severe physical trigger like hypoxia and acidosis stand out.Patients presenting with these ECG features should not be treated with thrombolysis but referred to a HUB center for coronary angiography.
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