Sewage Sludge Gasification in a Fluidized Bed: Experimental Investigation and Modeling

Fluidized bed gasification is a promising process technology to manage the growing amount of sewage sludge (SS) requiring disposal. Two samples of SS, produced in different seasons of the year by a municipal wastewater treatment plant, were subjected to gasification at 850 °C in a bench-scale fluidized bed reactor using, as a gasification agent, a nitrogen/air mixture at different values of oxygen/fuel equivalence ratio (ER = 0.1–0.2). The starting materials and the output streams (syngas, tar, and solid residues) were thoroughly characterized. The fate of specific SS constituents and the characteristics of bottom ashes were addressed, so contributing to the problem of a proper SS management approach in the context of the circular economy. Computer-aided simulations were also performed, which allowed us to predict the composition of the syngas from SS gasification under operating conditions different from those experimentally investigated (i.e., reactor temperature and ER)

The State Elite of the province of Buenos Aires: Continuities and changes during the Kirchnerist years

El artículo tiene como objetivo describir la fisonomía de la elite estatal de la Provincia de Buenos Aires en el período 2002-2015. Para ello se presenta, en primer lugar, el organigrama provincial en los dos máximos niveles de cargos ejecutivos, a fin de identificar sus rasgos y las transformaciones que sufrieron a lo largo de los años kirchneristas. En segundo lugar, se describen los rasgos de los individuos que ocuparon estos cargos, considerados como posiciones de elite, haciendo foco en sus trayectorias personales y políticas. Los principales hallazgos son dos: por una parte, la baja permanencia de individuos en sus cargos; por otra, la existencia de un pequeño número de funcionaries que atravesaron todo el período ocupando distintos cargos. En función de estos datos es posible afirmar que la elite bonaerense en los años kirchneristas tuvo un pequeño “núcleo duro” alrededor del cual circularon numerosos actores con pertenencias efímeras.The article aims to describe the Buenos Aires Province State elites during 2002-2015. It presents, firstly, how the State structure had changed both in ministries and secretaries. Secondly, the article describes the personal and political trajectories of those who had occupied political positions. The most relevant conclusion is that there were a few actors who stayed as part of state elites’ during those years in the Buenos Aires Province. According to these points it is possible to affirm that the Buenos Aires elites in the Kirchnerism era had a resistant “hard core,” around which circulated many actors with short belongings.Fil: Rodrigo, Cintia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Departamento de Historia. Centro de Estudios Históricos; ArgentinaFil: Tavano, Carolina Sofia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentina. Instituto de Desarrollo Económico y Social; Argentina. Universidad Nacional de General Sarmiento; ArgentinaFil: Aldao, Joaquin Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Centro de Estudios Sociales y Politicos.; ArgentinaFil: Aelo, Oscar Humberto. Universidad Nacional de Mar del Plata. Facultad de Humanidades; Argentin

Spatiotemporal variability of dissolved inorganic macronutrients along the northern Antarctic Peninsula (1996–2019)

The northern Antarctic Peninsula is a key region of the Southern Ocean due to its complex ocean dynamics, distinct water mass sources, and the climate-driven changes taking place in the region. Despite the importance of macronutrients in supporting strong biological carbon uptake and storage, little is known about their spatiotemporal variability along the northern Antarctic Peninsula. Hence, we explored for the first time a 24-year time series (1996–2019) in this region to understand the processes involved in the spatial and interannual variability of macronutrients. We found high macronutrient concentrations, even in surface waters and during strong phytoplankton blooms. Minimum concentrations of dissolved inorganic nitrogen (DIN; 16 μmol kg−1), phosphate (0.7 μmol kg−1), and silicic acid (40 μmol kg−1) in surface waters are higher than those recorded in surrounding regions. The main source of macronutrients is the intrusions of Circumpolar Deep Water and its modified variety, while local sources (organic matter remineralization, water mass mixing, and mesoscale structures) can enhance their spatiotemporal variability. However, we identified a depletion in silicic acid due to the influence of Dense Shelf Water from the Weddell Sea. Macronutrient concentrations show substantial interannual variability driven by the balance between the intrusions of modified Circumpolar Deep Water and advection of Dense Shelf Water, which is largely modulated by the Southern Annular Mode (SAM) and to some extent by El Niño-Southern Oscillation (ENSO). These findings are critical to improving our understanding of the natural variability of this Southern Ocean ecosystem and how it is responding to climate changes

Cardiac magnetic resonance predictors of left ventricular remodelling following acute ST elevation myocardial infarction: The VavirimS study

Left ventricular (LV) remodelling (REM) ensuing after ST-elevation myocardial infarction (STEMI), has typically been studied by echocardiography, which has limitations, or cardiac magnetic resonance (CMR) in early phase that may overestimate infarct size (IS) due to tissue edema and stunning. This prospective, multicenter study investigated LV-REM performing CMR in the subacute phase, and 6 months after STEMI

Prolonged higher dose methylprednisolone vs. conventional dexamethasone in COVID-19 pneumonia: a randomised controlled trial (MEDEAS)

Dysregulated systemic inflammation is the primary driver of mortality in severe COVID-19 pneumonia. Current guidelines favor a 7-10-day course of any glucocorticoid equivalent to dexamethasone 6 mg·day-1. A comparative RCT with a higher dose and a longer duration of intervention was lacking

Variability of chlorophyll-a from ocean color images in the La Plata continental shelf region

Satellite-derived chlorophyll-a fields have been used to investigate temporal and spatial variability of chlorophyll-a concentration over the continental shelf zone (25–401S and 60–451W) close to the La Plata River estuary. Ocean color data used in this study were obtained by the Sea-viewing Wide Field-of- view Sensor (SeaWiFS) and consisted of 368 weekly averaged Standard Mapped Images (SMI), from October 1997 to September 2005. Fourier harmonic and EOF analyses were used to study the variability of log-transformed chlorophyll-a concentration in the region. The harmonic analysis has shown that the annual cycle was the most dominant signal followed by the semi- and quadri-annual cycles, in certain areas. The strong annual cycle is mainly present in latitudes lower than 341S where relatively high amplitudes ($1.9 mg mÀ3) in pigment variation are seen over the southern Brazilian continental shelf. The semi-annual cycle is mainly associated with the Brazil–Malvinas frontal zone oscillation while the ̃ 4-year signal is related to positive La Plata discharge anomalies influenced by El Nino events. After removing the annual signal from the log-transformed chlorophyll anomalies, the EOF results showed that the first three modes captured 85.1% of the variability associated with the regional mean phytoplankton chlorophyll pattern in our smoothed data set. The first three modes explained, respectively, 63.4%, 14.1% and 7.6%. The EOF results showed that the long-term chlorophyll time/space patterns are associated with both La Plata discharge anomaly (mode 1) and alongshore wind stress (mode 2). A reconstruction of the chlorophyll anomaly fields has been made using the two leading EOF modes over two periods of high La Plata River discharge, during ENSO events. In the first event, the spatial patterns of high chlorophyll anomaly were confined to the southern portion of the region, associated with NE winds, which push the plume near the estuary mouth. The second period revealed an elongated tongue of positive chlorophyll anomalies over the Uruguayan and Brazilian middle continental shelves, associated with favorable SW winds. The analyses performed in this study allowed identification of the main modes of variability in SeaWiFS-derived chlorophyll in the region, which were consistent with modulations of important regional environmental forcing mechanisms

Light absorption by phytoplankton, non-algal particles and dissolved organic matter at the Patagonia shelf-break in spring and summer

Satellite image studies and recent in situ sampling have identified conspicuous phytoplankton blooms during spring and summer along the Patagonia shelf-break front. The magnitudes and spectral characteristics of light absorption by total particulate matter (phytoplankton and detritus) and colored dissolved organic matter (CDOM) have been determined by spectrophotometry in that region for spring 2006 and late summer 2007 seasons. In spring, phytoplankton absorption was the dominant optical component of light absorption (60–85%), and CDOM showed variable and important contributions in summer (10–90%). However, there was a lack of correlation between phytoplankton biomass (chlorophyll-a concentration or [chl a]) and the non- algal compartment in both periods. A statistically significant difference was found between the two periods with respect to the CDOM spectral shape parameter (Scdom), with means of 0.015 (spring) and 0.012 nmÀ1 (summer). Nonetheless, the mean Scdm values, which describe the slope of detritus plus CDOM spectra, did not differ between the periods (average of 0.013 nmÀ1). Phytoplankton absorption values in this work showed deviations from mean parameterizations in previous studies, with respect to [chl a], as well as between the two study periods. In spring, despite the microplankton dominance, high specific absorption values and large dispersion were found (a*ph(440) 1⁄4 0.0470.03 m2 mg [chl a]À1), which could be attributed to an important influence of photo-protector accessory pigments. In summer, deviations from general trends, with values of a*ph(440) even higher (0.0970.02 m2 mg [chl a]À1), were due to the dominance of small cell sizes and also to accessory pigments. These results highlight the difficulty in deriving robust relationships between chlorophyll concentration and phytoplankton absorption coefficients regardless of the season period. The validity of a size parameter (Sf) derived from the absorption spectra has been demonstrated and was shown to describe the size structure of phytoplankton populations, independently of pigment concentration, with mean values of 0.41 in spring and 0.72 in summer. Our results emphasize the need for specific parameterization for the study region and seasonal sampling approach in order to model the inherent optical properties from water reflectance signatures

La élite estatal de la provincia de Buenos Aires: continuidades y cambios durante los años kirchneristas

The article aims to describe the Buenos Aires Province State elites during 2002-2015. It presents, firstly, how the State structure had changed both in ministries and secretaries. Secondly, the article describes the personal and political trajectories of those who had occupied political positions. The most relevant conclusion is that there were a few actors who stayed as part of state elites’ during those years inthe Buenos Aires Province. According to thesepoints it is possible to affirm that the Buenos Aires elites in the Kirchnerism era had a resistant“hard core,” around which circulated many actors with short belongings.El artículo tiene como objetivo describir la fisonomía de la élite estatal de la Provincia de Buenos Aires en el período 2002-2015. Para ello se presenta, en primer lugar, el organigrama provincial en los dos máximos niveles de cargos ejecutivos, a fin de identificar sus rasgos y las transformaciones que sufrieron a lo largo de los años kirchneristas. En segundo lugar, se describen los rasgos de los individuos que ocuparon estos cargos, considerados como posiciones de elite, haciendo foco en sus trayectorias personales y políticas. Los datos presentados son resultado del procesamiento de una base inédita del equipo de investigación. Los principales hallazgos son dos: por una parte, la baja permanencia de individuos en sus cargos; por otra, la existencia de un pequeño número de funcionaries que atravesaron todo el período ocupando distintos cargos. En función de estos datos es posible afirmar que la elite bonaerense en los años kirchneristas tuvo un pequeño “núcleo duro” alrededor del cual circularon numerosos actores con pertenencias efímeras

Evaluation of SeaWiFS chlorophyll algorithms in the southwestern atlantic and southern oceans

Bio-optical measurements of spectral upwelling radiance and surface chlorophyll-a concentration have been conducted during 15 cruises between 1995 and 2004. The bio-optical data were divided into two sub-sets: the Southwestern Atlantic Ocean (SwAO), comprising a variety of biogeochemical provinces, from the oligotrophic waters in the South Atlantic gyre to the coastal waters influenced by La Plata River and Patos Lagoon discharge, and the Southern Ocean (SO) data set, comprising sampling stations south of the mean position of the Polar Front, with most stations being located in the vicinity of the Antarctic Peninsula. We derived regional chlorophyll algorithms for both regions and comparisons were made with the NASA’s OC4v4 (operational algorithm) and OC2v4. For the Southwestern Atlantic region, the NASA OC4v4 algorithm presented a reasonable performance (r 2=0.87, rmse-L=0.475, N=136) as compared to the revised algorithm for SwAO data (r 2=0.89, rmse-L=0.426, N=136). A few stations under strong river plume influence were not considered in the analyses. These were detected by a higher reflectance at 670 nm, at low in situ chlorophyll concentration (b2 mg mÀ3). These results show that empirical algorithms applied to in-situ radiance data have a limited ability to extract accurate chlorophyll estimates below a 30% uncertainty level. For Southern Ocean stations, a 2-band linear-type model was generated (r 2=0.64, rmse-L=0.347, N=77), which significantly improved the bias (6.4%) as compared to NASA’s OC4v4 algorithm (bias=À21.7%). An evaluation of some published high-latitude algorithms on our data set has shown a better performance by taxon-specific models, even from distant regions. A validation experiment of the normalized spectral water-leaving radiances and chlorophyll-a SeaWiFS products was also conducted using the FURG-SwAO/SO data set, through a match-up exercise. Despite the relatively low number of pairs of radiometric measurements, SeaWiFS estimations compare well with in situ data (0.77br 2b0.98, N=21), although the satellite estimate show a marked bias (À35.6%) in the blue band nLw (412). Regarding the chlorophyll-a concentration, an overall agreement was observed (r 2=0.77, rmse-L=0.66, N=28), with a mean absolute percentage difference of 66%, which is above the goal generally accepted of 35% for satellite ocean color chlorophyll estimates. For the studied Southern Ocean area (mainly the Bransfield Strait), NASA’s OC4v4 algorithm systematically underestimates chlorophyll above 0.2 mg mÀ3, as previously demonstrated by other researchers

Empirical and semi-analytical chlorophyll algorithms in the south- western Atlantic coastal region (25–40uS and 60–45uW).

Global ocean colour algorithms, used to extract chlorophyll concentration in the ocean surface, normally overestimate pigment values in coastal regions, due to optical interference of water components. The objective of the present investigation was to test the performance of both empirical (SeaWiFS OC4v4) and semi-analytical (GSM01 and CARDER) algorithms in the south-western Atlantic. In situ pigment and optical data have been collected in waters influenced by continental discharge from La Plata River and Patos Lagoon. The data was used to develop a regional version of the empirical SeaWiFS OC2v4 algorithm (termed OC2-LP). The relative percentage difference (RPD) between in situ and algorithm-derived chlorophyll was 11% in the regional version as compared to the global OC4v4 (RPD527%). The GSM01 and CARDER showed RPD of 14% and 31%, respectively. We have also tested the accuracy of the four algorithms (OC4v4, OC2-LP, GSM01 and CARDER) on SeaWiFS images taken over two cruise periods in the study region (winter of 2003 and summer of 2004). A seasonal difference was observed, where both OC4v4 and OC2-LP overestimate chlorophyll in summer at a higher magnitude than in winter, and the GSM01 algorithm showed a marked underestimation of chlorophyll in winter. The CARDER model showed a good performance both in winter and summer, when applied to satellite-retrieved radiances. Our results show that the use of semi-analytical models does not improve significantly the accuracy of chlorophyll retrievals in coastal areas when not properly tuned with regional inherent optical properties measurements