727 research outputs found
Semi-continuous anaerobic digestion of mixed wastewater sludge with biochar addition
No full textThis work analysed the effects of Biochar (BC) addition to the Anaerobic digestion (AD) of wastewater Mixed sludge (MS) in semi-continuous mode. A 3 L digester was operated at 37 °C for 100 days, feeding MS collected every three weeks in the same wastewater treatment plant, and 10 g L−1 of BC. The average performance of MS digestion (biogas 188 NmL d−1, 68% methane) improved in presence of BC (biogas 244 NmL d−1, 69% methane). According to the results of the multiple linear regression analysis performed on the experimental data, the 79% variation of the soluble COD in the MS was the driving factor for the 38% increase of biogas and methane yields. In conclusion, in the considered experimental conditions, the variability of the substrate's composition was the key factor driving the performances of the AD of MS, independently of the addition of BC
Addition of different biochars as catalysts during the mesophilic anaerobic digestion of mixed wastewater sludge
No full textBiochar (BC) recently gained attention as an additive for anaerobic digestion (AD). This work aims at a critical analysis of the effect of six BCs, with different physical and chemical properties, on the AD of mixed wastewater sludge at 37 °C, comparing their influence on methane production and AD kinetics. AD batch tests were performed at the laboratory scale operating 48 reactors (0.25 L working volume) for 28 days with the addition of 10 g L−1 of BC. Most reactors supplemented with BCs exhibited higher (up to 22%) methane yields than the control reactors (0.15 Nm3 kgVS−1). The modified Gompertz model provided maximum methane production rate values, and in all reactors the lag-phase was equal to zero days, indicating a good adaptation of the inoculum to the substrate. The potential correlations between BCs’ properties and AD performance were assessed using principal component analysis (PCA). The PCA results showed a reasonable correlation between methane production and the BCs’ O–C and H–C molar ratios, and volatile matter, and between biogas production and BCs’ pore volume, specific surface area, and fixed and total carbon. In conclusion, the physic-chemical properties of BC (specifically, hydrophobicity and morphology) showed a key role in improving the AD of mixed wastewater sludge
Figs. 39–50 in Molecular phylogeny and classification of Lyropaeini (Coleoptera: Lycidae) with description of larvae and new species of Lyropaeus
No full textFigs. 39–50. Male genitalia of Lyropaeus (Lyroneces): 39, L. dominator Kleine; 40, L. humeralis Kleine; 41, L. monticola Kleine; 42, L. optabilis Kleine; 43, L. philippinensis Kleine; 44, L. ritsemae Gorham; 45, L. rubrostriatus Kleine; 46, L. waterhousei Gorham. Mouth parts of L. (Lyroneces) optabilis: 47, labium; 48, maxillary palpus; 49, mandible. Pronotum: 50, L. (Lyroneces) optabilis. Scale bars = 0.25 mm (Figs. 39–46, 47–49); scale bar = 0.5 mm (Fig. 50).Published as part of Masek, Michal, Ivie, Michael A., Palata, Vaclav & Bocak, Ladislav, 2014, Molecular phylogeny and classification of Lyropaeini (Coleoptera: Lycidae) with description of larvae and new species of Lyropaeus, pp. 136-145 in Raffles Bulletin of Zoology 62 on page 142, DOI: 10.5281/zenodo.535356
Analysis of the influence of activated biochar properties on methane production from anaerobic digestion of waste activated sludge
No full textThis work describes the impacts of biochar (BC) addition to the anaerobic digestion (AD) of waste activated sludge (WAS). Three BCs, produced by pyrolysis at 550 °C of different waste biomasses (soft wood, sewage sludge and rice husk), then physically activated at 900 °C with CO2, were investigated as additives. AD tests were performed in batch mode at 37 °C, feeding 2% total solids and 10 g L−1 BC. While none of the considered BCs increased biogas yield compared to control digesters, the activated BCs with higher surface area, porosity and hydrophobicity (RH550a from rice husk and SS550a from sewage sludge) boosted methane yield (up to 105% for RH550a). The experimental methane production were: 0.037 Nm3 kgVS−1 for SWP550a, 0.081 Nm3 kgVS−1 for SS550a, 0.142 Nm3 kgVS−1 for RH550a and 0.069 Nm3 kgVS−1 for control reactors. CO2 adsorption (3.14 mmol g−1 for RH550a, 0.97 mmol g−1 SS550a) calculated from experimental data was consistent with literature (0.4–2.3 mmol g−1 BC). The fitting of experimental methane productions through the modified Gompertz equation showed an acceleration of methane production for all BCs, with a reduction of the lag phase compared to control reactors (0.5 days vs 2.6 days). This work, although confirming literature data about CO2 adsorption, brings new insights on the influence of specific physico-chemical properties of BC as additive in AD of WAS. Surface area, porosity, hydrophobicity and alkali and alkaline metals content in ashes were the most important BC properties affecting AD of activated sewage sludge
On the Use of Actinometric Emission Spectroscopy in SF6-O2 Discharges: Theoretical and Experimental Analysis
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Supplemental Material: Table S1 summary of primary study characteristics
No full textSupplementary materials included in the follow review:
Shen, X., & Masek, L. (2023). The playful mediator, moderator, or outcome? An integrative review of the roles of play and playfulness in adult-centered psychological Interventions for mental health. The Journal of Positive Psychology. 10.1080/17439760.2023.228895
Thalamic Iron Differentiates Primary-Progressive and Relapsing-Remitting Multiple Sclerosis
No full textBACKGROUND AND PURPOSE: Potential differences between primary progressive and relapsing remitting multiple sclerosis are the subject of ongoing controversial discussions. The aim of this work was to determine whether and how primary-progressive and relapsing-remitting multiple sclerosis subtypes differ regarding conventional MR imaging parameters, cerebral iron deposits, and their association with clinical status. MATERIALS AND METHODS: We analyzed 24 patients with primary-progressive MS, 80 with relapsing-remitting MS, and 20 healthy controls with 1.5T MR imaging for assessment of the conventional quantitative parameters: T2 lesion load, T1 lesion load, brain parenchymal fraction, and corpus callosum volume. Quantitative susceptibility mapping was performed to estimate iron concentration in the deep gray matter. RESULTS: Decreased susceptibility within the thalamus in relapsing-remitting MS compared with primary-progressive MS was the only significant MR imaging difference between these MS subtypes. In the relapsing-remitting MS subgroup, the Expanded Disability Status Scale score was positively associated with conventional parameters reflecting white matter lesions and brain atrophy and with iron in the putamen and caudate nucleus. A positive association with putaminal iron and the Expanded Disability Status Scale score was found in primary-progressive MS. CONCLUSIONS: Susceptibility in the thalamus might provide additional support for the differentiation between primary-progressive and relapsing-remitting MS. That the Expanded Disability Status Scale score was associated with conventional MR imaging parameters and iron concentrations in several deep gray matter regions in relapsing-remitting MS, while only a weak association with putaminal iron was observed in primary-progressive MS suggests different driving forces of disability in these MS subtypes
W świecie masek. Tożsamość historyka literatury
No full textThe author looks at metaphors and comparisons used by researchers to describe a literature historian, utilizing a cognitivist approach – that in cognizance, metaphors serve a function analogous to our senses and like masks, they expose some features of an item. In the article, she emphasizes a multitude of masks a literature historian must wear, often forced by current paradigms, and thus – she points to a variety of the historian’s roles, which results in a blurred identity.The author looks at metaphors and comparisons used by researchers to describe a literature historian, utilizing a cognitivist approach – that in cognizance, metaphors serve a function analogous to our senses and like masks, they expose some features of an item. In the article, she emphasizes a multitude of masks a literature historian must wear, often forced by current paradigms, and thus – she points to a variety of the historian’s roles, which results in a blurred identity
Potassium doping increases biochar carbon sequestration potential by 45%, facilitating decoupling of carbon sequestration from soil improvement
No full textNegative emissions technologies offer an important tool to limit the global warming to <2 °C. Biochar is one of only a few such technologies, and the one at highest technology readiness level. Here we show that potassium as a low-concentration additive in biochar production can increase biochar's carbon sequestration potential; by up to 45% in this study. This translates to an increase in the estimated global biochar carbon sequestration potential to over 2.6 Gt CO2-C(eq) yr-1, thus boosting the efficiency of utilisation of limited biomass and land resources, and considerably improving the economics of biochar production and atmospheric carbon sequestration. In addition, potassium doping also increases plant nutrient content of resulting biochar, making it better suited for agricultural applications. Yet, more importantly, due to its much higher carbon sequestration potential, AM-enriched biochar facilitates viable biochar deployment for carbon sequestration purposes with reduced need to rely on biochar's abilities to improve soil properties and crop yields, hence opening new potential areas and scenarios for biochar applications.</p
W świecie masek : tożsamość historyka literatury
No full textThe author looks at metaphors and comparisons used by researchers to describe a literature
historian, utilizing a cognitivist approach – that in cognizance, metaphors serve
a function analogous to our senses and like masks, they expose some features of an
item. In the article, she emphasizes a multitude of masks a literature historian must wear,
often forced by current paradigms, and thus – she points to a variety of the historian’s
roles, which results in a blurred identity
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