Astor Piazzolla deixou-nos uma obra peculiar com um estilo musical que combina os elementos do tango argentino com os da música clássica e do jazz americano que viria a marcar as décadas de 50 a 70 ...do século XX. Este estudo debruça-se sobre uma coleção de seis estudos escritos originalmente para flauta solo em 1987, designados por Astor Piazzolla Tango-Études. Na passagem do centenário do seu nascimento, assinalam-se os dois concertos que realizou em Portugal, o contexto e o impacto que tiveram na época nas cidades de Lisboa e Porto, onde atuou.
Astor Piazzolla deixou-nos uma obra peculiar com um estilo musical que combina os elementos do tango argentino com os da música clássica e do jazz americano que viria a marcar as décadas de 50 a 70 ...do século XX. Este estudo debruça-se sobre uma coleção de seis estudos escritos originalmente para flauta solo em 1987, designados por Astor Piazzolla Tango-Études. Na passagem do centenário do seu nascimento, assinalam-se os dois concertos que realizou em Portugal, o contexto e o impacto que tiveram na época nas cidades de Lisboa e Porto, onde atuou.
This paper reports an experimental study of the water injection control parameters in a single-cylinder research engine at 1500 rpm, under 5 and 8 bar indicated mean effective pressure (IMEP). The ...results were used to validate a tridimensional numerical model, and simulations extrapolated the experimental test conditions up to 10 bar IMEP and 3000 rpm. The main purpose of this work was to assess the impact of different water injection strategies on the engine combustion parameters. An interesting finding was that variations in the water injection temperature did not significantly influence fuel conversion efficiency, as one could expect. Nevertheless, the proper water injection timing and pressure calibration reduced the indicated specific fuel consumption (ISFC) by 3% and 3.5%, respectively, with more pronounced effects at the highest engine load. Furthermore, if knock mitigation is prioritized over ISFC, the amount of water injected can be reduced. However, this strategy leads to in-cylinder temperature reductions that influence the burning speed and consequently the peak in-cylinder pressure.
Soybean biodiesel (B100) has been playing an important role in Brazilian energy matrix towards the national bio-based economy. Greenhouse gas (GHG) emissions is the most widely used indicator for ...assessing the environmental sustainability of biodiesels and received particular attention among decision makers in business and politics, as well as consumers. Former studies have been mainly focused on the GHG emissions from the soybean cultivation, excluding other stages of the biodiesel production. Here, we present a holistic view of the total GHG emissions in four life cycle stages for soybean biodiesel. The aim of this study was to assess the GHG emissions of Brazilian soybean biodiesel production system with an integrated life cycle approach of four stages: agriculture, extraction, production and distribution. Allocation of mass and energy was applied and special attention was paid to the integrated and non-integrated industrial production chain. The results indicated that the largest source of GHG emissions, among four life cycle stages, is the agricultural stage (42-51%) for B100 produced in integrated systems and the production stage (46-52%) for B100 produced in non-integrated systems. Integration of industrial units resulted in significant reduction in life cycle GHG emissions. Without the consideration of LUC and assuming biogenic CO2 emissions is carbon neutral in our study, the calculated life cycle GHG emissions for domestic soybean biodiesel varied from 23.1 to 25.8 gCO2eq. MJ-1 B100 and those for soybean biodiesel exported to EU ranged from 26.5 to 29.2 gCO2eq. MJ-1 B100, which represent reductions by 65% up to 72% (depending on the delivery route) of GHG emissions compared with the EU benchmark for diesel fuel. Our findings from a life cycle perspective contributed to identify the major GHG sources in Brazilian soybean biodiesel production system and they can be used to guide mitigation priority for policy and decision-making. Projected scenarios in this study would be taken as references for accounting the environmental sustainability of soybean biodiesel within a domestic and global level.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Estimation of aboveground biomass and net primary production of pine, oak and pine–oak mixed stands.•Mixed stands had significantly higher ANPP than the pure stands.•Aboveground biomass was not ...significantly different among the 3 stands types.•Stem NPP in mixed stands lower for each species than in pure stands.•Production efficiency was significantly greater for mixed stands.
Pine and oak are common tree species in the Vila Real district, northern Portugal, a region where forests are an important land use (38%). The net primary production (NPP) of these forests is not well known. The objective of this study was to quantify the aboveground biomass and aboveground NPP (ANPP) of pine (Pinus pinaster Aiton), pyrenean oak (Quercus pyrenaica Willd.) and mixed pine–oak forests in the Vila Real district and to evaluate the relationships between ANPP and their stand characteristics. To achieve this objective, 15 stands of pine, 15 stands of oak and 9 stands of mixed pine–oak were studied between 2008 and 2011. ANPP average (and range) of pine, oak and mixed stands were 7.9 (2.9–15.1), 7.3 (3.0–12.1), and 12.1 (6.5–17.2) Mgha−1 yr−1, respectively. An analysis of covariance (ANCOVA), to reduce the within-groups variability and detect the differences between the stand compositions, was performed. In this analysis, we rejected the null hypothesis that the composition stands had the same mean among ANPP. Mixed stands had a significantly higher mean ANPP than pine or oak. Also, we verified that in pine, the greater distribution of biomass was on the stem (4.0±0.7Mgha−1 yr−1, 50% of the total productivity) component where carbon sequestration is retained longer, whereas in oak and mixed stands the foliage was the component with the greater distribution of biomass (4.0 and 6.0Mgha−1 yr−1, respectively). Aboveground biomass was significantly different among the three stands types and averaged 83.4, 61.4 and 110.5Mgha−1 for pine, oak and mixed stands, respectively. Regression models performed showed that there was a strong relationship between aboveground biomass and basal area in all stands. This study concludes that the production efficiency, defined as stem productivity/leaf area index, was significantly different in mixed stands. Pine had the greatest production efficiency in all stand types and, in mixed stands, had 85% of the total production efficiency.
Four commercial lipase preparations immobilized by covalent attachment on epoxy-polysiloxane-β-cyclodextrin were tested as potential biocatalysts to mediate the esterification reaction of isopentanol ...with caprylic acid in solvent-free medium. Among them, the immobilized lipase from Rhizopus oryzae was the most active biocatalyst, attained ester conversion higher than 80% in 24 h, being selected for subsequent tests using fusel oil as source of isopentanol. An experimental design was performed and the analysis of the results revealed that the formation of the isopentyl caprylate was strongly influenced by the variable molar ratio at 95% of confidence level. The proposed mathematical model allowed predicting that the excess of caprylic acid (molar ratio fusel oil to acid of 1:1.5) and reaction temperature of 45 ºC favor the reaction to attain high ester conversion. Sensory evaluation of the flavors profile in relation to all the components involved in the reaction (caprylic acid, fusel oil and esters) showed that the formed esters had distinct aromas from the starting materials, confirming that the changes in flavors occurred before and after esterification reactions.
In this manuscript, MCM-41 and Co-MCM-41 were synthesized to evaluate the effect of the metal incorporated in the structure of the mesoporous material used in the benzene removal in aqueous medium ...containing hydrogen peroxide (H2O2). The decomposition of H2O2 in the medium containing MCM-41 and Co-MCM-41 was investigated. The techniques used to characterize these materials showed satisfactory results, proving that the synthesis was effective. The decomposition of hydrogen peroxide carried out in the ultraviolet/visible molecular absorption spectrophotometer revealed that the pH of the medium and the presence of cobalt influence its decomposition. In the reaction containing benzene + Co-MCM-41 + H2O2, it was possible to confirm this information, because there was practically no decomposition at pH = 1.5, 3.0 and 5.0, whereas decomposition was considerable at pH = 7.0 and 10.0 and all H2O2 was decomposed at pH = 12. Tests containing benzene + H2O2 + MCM-41 resulted in a higher removal of analytes in an alkaline medium. The last catalytic tests contained benzene + Co(II) + H2O2 in the aqueous reaction medium; compared to benzene + Co-MCM-41 + H2O2, it was found that the influence of Co-MCM-41 can be better viewed in pH = 10.0 and 12.0, because 82.1% of benzene was removed after 5 h.
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•The efficiency of benzene removal is a function of pH, H2O2 and catalyst.•The increase of pH promotes extensive removal of benzene in water with H2O2/Co-MCM-41.•MCM-41 delays the decomposition of H2O2 in an aqueous medium.•The decomposition of H2O2 is slower in a medium containing Co-MCM-41.•The efficiency of benzene removal is linked to the H2O2 decomposition rate.
Oxaliplatin based chemotherapy is often used as adjuvant therapy in colon and rectal cancer. A reported side effect is Sinusoidal Obstruction Syndrome which is characterized by a spectrum of ...pathologic changes, from sinusoidal dilation, peri-sinusoidal haemorrhage, peliosis and nodular regenerative hyperplasia. Very rarely it can cause the development of liver nodules mimicking liver metastases. Herein, we report a case of Sinusoidal Obstruction Syndrome causing a liver nodule suspicious of liver metastasis on imaging. This is the third reported case of this complication of oxaliplatin toxicity, in which resection was performed and pathological diagnosis confirmed.
We report the case of a 59 year old man with stage III colon cancer who underwent sigmoidectomy followed by adjuvant chemotherapy with oxaliplatin. One year after surgery a liver nodule was detected and the patient underwent right hepatectomy. Pathology showed no liver nodule and diagnosed sinusoidal obstruction syndrome.
We describe the third reported case of a liver lesion mimicking a liver metastasis after oxaliplatin-based chemotherapy for colon cancer. We suggest that in patients heavily treated with oxaliplatin with de novo liver nodules, this differential diagnosis should be considered. In particular, in this population of patients an intense imagiologic evaluation and even a preoperative biopsy should be pursued to confirm the diagnosis of malignancy and avoid overtreatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Since autumn 2022, observed numbers of paediatric invasive group A
Streptococcus
infections in Portugal (n = 89) were higher than in pre-COVID-19 seasons. Between September 2022 and May 2023, the ...dominant diagnoses were pneumonia (25/79), mostly with empyema (20/25), and sepsis (22/79). A number of cases required admission to intensive care (27/79) and surgery (35/79), and the case fatality rate was 5.1% (4/79). Genomic sequencing (n = 55) revealed multiple genetic lineages, dominated by the M1
UK
sublineage (26/55) and more diverse
emm
12 isolates (12/55).
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