99 research outputs found

    Coastal zone water quality: Calibration of a water-turbidity equation for MODIS data

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    A nephelometric turbidity algorithm has been specifically calibrated for coastal waters in Sicily. To this purpose, intensive field campaigns were performed in July, August and September 2008. Measurements were collected in situ in three different gulfs. Statistical analysis suggests that field data should be spatially grouped but temporally separated; hence, new calibration parameters have been proposed. Turbidity retrieved by applying the algorithm using literature coefficients and the ones calibrated in situ are shown and compared. The comparison demonstrated that a specific calibration was necessary for quantitatively monitoring turbidity in Sicilian gulfs

    Assessing actual evapotranspiration in irrigation districts using Landsat TM images and SEBAL model: Potential uses for irrigation monitoring

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    Satellite imagery allows the observation of large land stretches and the acquisition of worthwhile information that can be used efficaciously in agro-hydrologic systems. On the other hand, remotely sensed data coupled with energy balance models represent reliable tools to estimate actual evapotranspiration (ET). Objective of the research was to propose a methodology to estimate ET by using Landsat TM images and surface energy balance, thus allowing the monitoring of current irrigation practices and/or possible vegetation stress. The proposed methodology was applied in an irrigation district managed by \u201cConsorzio di Bonifica Agrigento 3\u201d, Castelvetrano, Sicily (Italy), in which water is distributed by a pressurized distribution network operating on-turn. Satellite information retrieved by a set of Landsat TM images allowed to implement the surface energy balance model (SEBAL) in order to map the spatial distribution of instantaneous ET over two main crops (olives and grapevines), during irrigation seasons (from May to September) 2009 and 2010. These instantaneous values were then up-scaled to daily values based on the hypothesis of self-preservation of evaporative fraction. Finally, daily acquisitions were used to derive ET within longer time intervals, by assuming the by assuming proportionality to temporal dynamics of the reference evapotranspiration (ET0) computed using standard ground meteo-data. With reference to the acquisition days, the comparison between SEBAL outputs and maximum daily crop evapotranspiration (ETc) estimated with the FAO 56 approach, showed notable stress levels for both the investigated crops, except for the images acquired in May, when significant rainfall occurred in both years. Moreover, measurements of eddy covariance fluxes collected by a tower located in the district within an olive orchard, evidenced the general reliability of daily ET retrieved by the model and consequently the validity of the self-preservation hypothesis applied to upscale instantaneous ET. Even if the applied methodology can be considered a valuable tool to monitor irrigation practices, the availability of cloud-free satellite images, as well as the temporal frequency of sensing, are critical issues for the proposed applications

    Effect of biomass features on oxygen transfer in conventional activated sludge and membrane bioreactor systems

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    The aim of the present study was to compare the oxygen transfer efficiency in a conventional activated sludge and a membrane bioreactor system. The oxygen transfer was evaluated by means of the oxygen transfer coefficient (kLa)20 and α-factor calculation, under different total suspended solids concentration, extracellular polymeric substances, sludge apparent viscosity and size of the flocs. The (kLa)20 and α-factor showed an exponential decreasing trend with total suspended solid, with a stronger (kLa)20 dependence in the conventional activated sludge than the membrane bioreactor. It was noted that the (kLa)20 in the conventional activated sludge become comparable to that in membrane bioreactor when the TSS concentration in the conventional activated sludge was higher than 5 gTSS L-1. Operating under high carbon to nitrogen ratio, the (kLa)20 increased in both conventional activated sludge and membrane bioreactor because of the sludge deflocculation and a weaker dependence of (kLa)20 with total suspended solid was noted. The results indicated that the most important parameters on the oxygen transfer efficiency were in order: the total suspended solid concentration, flocs size, sludge apparent viscosity, the protein to polysaccharides ratio and extracellular polymeric substances content. Based on the influence of the main biomass features affecting the (kLa)20 and considering the typical operating conditions in both systems, those of membrane bioreactor appeared to be more favorable to oxygen transfer efficiency compared to conventional activated sludge process

    Toward a comprehensive dam monitoring: On-site and remote-retrieved forcing factors and resulting displacements (gnss and ps–insar)

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    Many factors can influence the displacements of a dam, including water level variability and environmental temperatures, in addition to the dam composition. In this work, optical-based classification, thermal diachronic analysis, and a quasi-PS (Persistent Scatter) Interferometric SAR technique have been applied to determine both forcing factors and resulting displacements of the crest of the Castello dam (South Italy) over a one-year time period. The dataset includes Sentinel-1A images acquired in Interferometric Wide swath mode using the Terrain Observation with Progressive Scans SAR (TOPSAR); Landsat 8 Thermal Infrared Sensor (TIRS) thermal images, and Global Navigation Satellite System (GNSS) for interpreting the motion of the top of the dam retrieved via interferometry. Results suggest that it is possible to monitor both dam water level and temperature periodic forcing factors and resulting displacements via a synergistic use of different satellite images

    Toward a Comprehensive Dam Monitoring: On-Site and Remote-Retrieved Forcing Factors and Resulting Displacements (GNSS and PS–InSAR)

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    Many factors can influence the displacements of a dam, including water level variability and environmental temperatures, in addition to the dam composition. In this work, optical-based classification, thermal diachronic analysis, and a quasi-PS (Persistent Scatter) Interferometric SAR technique have been applied to determine both forcing factors and resulting displacements of the crest of the Castello dam (South Italy) over a one-year time period. The dataset includes Sentinel-1A images acquired in Interferometric Wide swath mode using the Terrain Observation with Progressive Scans SAR (TOPSAR); Landsat 8 Thermal Infrared Sensor (TIRS) thermal images, and Global Navigation Satellite System (GNSS) for interpreting the motion of the top of the dam retrieved via interferometry. Results suggest that it is possible to monitor both dam water level and temperature periodic forcing factors and resulting displacements via a synergistic use of different satellite images

    An innovative respirometric method to assess the autotrophic active fraction: Application to an alternate oxic-anoxic MBR pilot plant

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    An innovative respirometric method was applied to evaluate the autotrophic active fraction in an alternate anoxic/oxic membrane bioreactor (MBR) pilot plant. The alternate cycle (AC) produces a complex microbiological environment that allows the development of both autotrophic and heterotrophic species in one reactor. The present study aimed to evaluate autotrophic and heterotrophic active fractions and highlight the effect of different aeration/non aeration ratios in a AC-MBR pilot plant using respirometry. The results outlined that the autotrophic active fraction values were consistent with the nitrification efficiency and FISH analyses, which suggests its usefulness for estimating the nitrifying population. Intermittent aeration did not significantly affect the heterotrophic metabolic activity but significantly affected the autotrophic biomass development. Finally, the heterotrophic active biomass was strongly affected by the wastewater characteristics, whereas the resultant autotrophic biomass was considerably affected by the duration of the aerated phase

    Optimization of acetate production from citrus wastewater fermentation

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    Citrus wastewater is a sugar-rich waste stream suitable for the recovery of energy of material from its treatment. In this study, fermentation of citrus wastewater was carried out to assess the optimal conditions to maximize the bioconversion of the organic substrate into acetate. Unbalanced nutrient (C: N: P 200:0.1:0.1) enabled the highest acetate production. The presence of the particulate organic fraction enabled to obtain a higher acetate concentration regardless the initial COD concentration. Initial pH values higher than 5 did not cause substantial differences on the maximum bioconversion of COD into acetate, whereas pH lower than 5 hindered the hydrolysis process. Lastly, the bioconversion rate of the organic substrate into acetate decreased from a maximum of 23% to a minimum of 8% related to the initial COD. The achieved results demonstrated that the characteristics of citrus wastewater enable its valorisation without the need to apply energy-consuming processes

    Blockchain for the Healthcare Supply Chain: A Systematic Literature Review

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    A supply chain (SC) is a network of interests, information, and materials involved in processes that produce value for customers. The implementation of blockchain technology in SC management in healthcare has had results. This review aims to summarize how blockchain technology has been used to address SC challenges in healthcare, specifically for drugs, medical devices (DMDs), and blood, organs, and tissues (BOTs). A systematic review was conducted by following the PRISMA guidelines and searching the PubMed and Proquest databases. English-language studies were included, while non-primary studies, as well as surveys, were excluded. After full-text assessment, 28 articles met the criteria for inclusion. Of these, 15 (54%) were classified as simulation studies, 12 (43%) were classified as theoretical, and only one was classified as a real case study. Most of the articles (n = 23, 82%) included the adoption of smart contracts. The findings of this systematic review indicated a significant but immature interest in the topic, with diverse ideas and methodologies, but without effective real-life applications

    Variations of the quality of care during the COVID-19 pandemic affected the mortality rate of non-COVID-19 patients with hip fracture

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    Introduction As COVID-19 roared through the world, governments worldwide enforced containment measures that affected various treatment pathways, including those for hip fractures (HFs). This study aimed to measure process and outcome indicators related to the quality of care provided to non-COVID-19 elderly patients affected by HF in Emilia-Romagna, a region of Italy severely hit by the pandemic. Methods We collected the hospital discharge records of all patients admitted to the hospitals of Emilia-Romagna with a diagnosis of HF from January to May in the years 2019 (pre-pandemic period) and 2020 (pandemic period). We analyzed surgery rate, surgery delays, length of hospital stay, timely rehabilitation, and 30-day mortality for each HF patient. We evaluated monthly data (2020 vs. 2019) with the chi-square and t-test, where appropriate. Logistic regression was used to investigate the differences in 30-day mortality. Results Our study included 5379 patients with HF. In April and May 2020, there was a significant increase in the proportion of HF patients that did not undergo timely surgery. In March 2020, we found a significant increase in mortality (OR = 2.22). Male sex (OR = 1.92), age ≥90 years (OR = 4.33), surgery after 48 hours (OR = 3.08) and not receiving surgery (OR = 6.19) were significantly associated with increased mortality. After adjusting for the aforementioned factors, patients hospitalized in March 2020 still suffered higher mortality (OR = 2.21). Conclusions There was a reduction in the overall quality of care provided to non-COVID-19 elderly patients affected by HF, whose mortality increased in March 2020. Patients' characteristics and variations in processes of care partially explained this increase. Policymakers and professionals involved in the management of COVID-19 patients should be aware of the needs of patients with other health needs, which should be carefully investigated and included in future emergency preparedness and response plans

    Dewatering of excess sludge produced by cas and mbr aerobic treatment plants. effects of biochemical stability and eps composition

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    This paper investigates the behavior of different sludges from several treatment plants at full and pilot scale configured as Conventional Activated Sludge (CAS) and Membrane Bio Reactor (MBR) plants treating different kinds of wastewaters. The sludges collected were subjected to complete analytical and technological characterization in order to correlate the rheological properties that affect the dewatering behavior to the sludge chemical physical properties. In detail the EPS from the samples collected is extracted and characterized in terms of carbohydrates, proteins, uronic acids and humic acids content. Moreover, once characterized, the sludges were subjected to AD in order to assess their bio-methanation potential and hence their biological stability. The final aim was to find correlations between the WWTP operational parameters (i.e. HRT, SRT, volumetric load coefficient, aeration) that finally affect its chemical composition (i.e. BMP, EPS composition) and the physical behavior of the sludge
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