Production of biochars from crop residues for the remediation of trace elements contaminated soils

Biochar is the solid material obtained from thermochemical conversion of biomass under oxygen-limited conditions (pyrolysis), which can be applied as soil ameliorant [1]. In general, biochar properties are very heterogeneous due to the diverse pyrolytic conditions and the wide variety of organic residues used as feedstock [2,3]. This study intends to discern the relationship between feedstock, pyrolysis conditions and biochar properties with the goal of producing biochar with a high potential for the stabilization of trace elements in contaminated soils. For that purpose, biochars were produced using four different feedstock (rice husk, pruned olive trees, olive pit and “alperujo”, a byproduct of olive oil production) and two contrasting pyrolysis systems: a batch reactor (temperature ranged from 350 to 600 ºC; reaction time from 0.5 to 4 h under N2 atmosphere with a heating and cooling rate of XY K s-1) and a continuously feed reactor with a screw conveyor (Pyreka reactor; 500 ºC, residence time 12 min and N2 flux). Biochars were characterized by determining their pH, water holding capacity (WHC), elemental composition (C, H, N), ash content, internal structure by micro-computed tomography and chemical composition by field emission scanning electron microscopy with energy dispersive X-ray spectroscopy. To complete the characterization, Brunauer-Emmett-Teller specific surface area (SSABET; N2 adsorptive) and solid-state 13C-NMR spectroscopy were performed. Biochars produced in the batch reactor showed that pH, WHC, TC, SSABET, ash content and aromaticity increased with temperature and reaction time. Rice husk biochars showed the highest WHC (> 100%), while olive pit biochars the lowest ones. Rice husk and olive pit biochars had the highest aromaticity (between 75 and 91% of aryl carbon). The H/Cat ratio decreased with increasing pyrolysis temperature, which suggests an increase in the condensation degree of the aromatic structures. SSABET surface area ranged from 20 to 100 m2 g-1 and increased with temperature. Biochars produced in the batch reactor resulted in greater SSA values than Pyreka biochars. The pyrolysis conditions of 500 ºC and 2 h at the batch reactor resulted in similar biochars than those produced by the Pyreka reactor at 500 ºC and 12 min. Taking into account the necessity of applying biochar to soil for remediation purposes, we selected those biochars of high stability (ratio H/Cat ≤ 0.7 & high aromaticity by 13C NMR spectroscopy), great capacity for the sorption and stabilization of trace elements2 (SSABET ≥ 100 m2g-1; pH ≥9) and good potential to act as soil amendment (high WHC). The pyrolysis conditions finally selected were 500 ºC and 2 hours for the steel-batch reactor and 500 ºC and 12 min for the continuous reactor. At these conditions, rice husk biochars showed the most appropriate characteristics to be used as soil amendment for trace-elements contaminated soils

Integrated Design in Welding and Incremental Forming: Material Model Calibration for Friction Stir Welded Blanks

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Energy transfer in single molecular photonic wires

Molecular photonics is a new emerging field of research around the premise that it is possible to develop optical devices using single molecules as building blocks. Truly technological impact in the field requires focussed efforts on designing functional molecular devices as well as having access to their photonic properties on an individual basis. In this Minireview we discuss our approach towards the design and single-molecule investigation of one-dimensional multimolecular arrays intended to work as molecular photonic wires. Three different schemes have been explored: a) perylene-based dimer and trimer arrays displaying coherent exciton delocalisation at room temperature; b) DNA-based unidirectional molecular wires containing up to five different chromophores and exhibiting weak excitonic interactions between neighbouring dyes; and c) one-dimensional multichromophoric polymers based on perylene polyisocyanides showing excimerlike emission. As a whole, our single-molecule data show the importance of well-defined close packing of chromophores for obtaining optimal excitonic behaviour at room temperature. Further improvement on (bio)chemical synthesis, together with the use of single-molecule techniques, should lead in the near future to efficient and reliable photonic wires with true device functionality

Single-molecule photobleaching probes the exciton wave function in a multichromophoric system

Ajuts: This work has been supported by the EC Program IHP- 99 (HPMF-CT-2002-01698)The exciton wave function of a trichromophoric system is investigated by means of single molecule spectroscopy at room temperature. Individual trimers exhibit superradiance and loss of vibronic structure in emission spectrum, features proving exciton delocalization. We identify two distinct photodegradation pathways for single trimers upon sequential photobleaching of the chromophores. The rate of each pathway is a measure for the contribution of the separate dyes to the collective excited state of the system, in this way probing the wave function of the delocalized exciton

Constructing Self-Dual Strings

We present an ADHMN-like construction which generates self-dual string solutions to the effective M5-brane worldvolume theory from solutions to the Basu-Harvey equation. Our construction finds a natural interpretation in terms of gerbes, which we develop in some detail. We also comment on a possible extension to stacks of multiple M5-branes.Comment: 1+19 pages, presentation improved, minor corrections, published versio

The annealing effect on structural and optical properties of ZnO thin films produced by RF sputtering

In this work, a study of the structure and optical properties of undoped ZnO thin films produced by r.f. magnetron sputtering technique as a function of the growth parameters is reported. Modification under annealing conditions is also analysed. Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and optical transmittance have been used. From the position of the (002) X-ray diffraction peak and the E2 (high) mode detected in Raman spectra, the residual stress both in the as-grown and in the annealed samples has been estimated

TPCS/PBAT blown extruded films added with curcumin as a technological approach for active packaging materials

The development of active packaging is a relevant topic demanding the development of films with diverse properties to preserve specific foodstuff. The objective of this work was to obtain extruded TPCS/PBAT films containing curcumin and evaluate it as an active antimicrobial and antioxidant packaging to protect chia oil from oxidative degradation. Morphology, thermal, mechanical, antimicrobial, and antioxidant evaluation of the films were conducted to determine whether the presence of curcumin affected the film’s properties. Infrared Spectroscopy indicated that curcumin addition affected the crosslinking reaction between citric acid and starch, which explains the changes in hydrophilicity and mechanical strength of the films. The incorporation of curcumin conferred antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria, as well as antioxidant activity. Films were tested as chia oil packaging, being verified that they successfully prevented oil degradation under accelerated stability test (60 °C for 7 days), demonstrating the feasibility of using TPCS/PBAT biodegradable films containing curcumin to obtain active packaging materials.Authors thank to CNPq (Chamada Universal– MCTI/CNPq Nº 14/2014, Processo 447768/2014-0), CAPES (Coordenação de Pessoal de Nível Superior Master's scholarship) and Fundação Araucária (Programa Universal/Pesquisa Básica e Aplicada 24/2012, protocolo 7334133700514041013) for the finantial support. This work was financially supported by Associate Laboratory LSRE-LCM (UID/EQU/50020/2019) funded by national funds through FCT/MCTES (PIDDAC), and Foundation for Science and Technology (FCT, Portugal). CIMO (UID/AGR/00690/2019) through FEDER under Program PT2020. To the national funding by FCT, P.I., through the institutional scientific employment program-contract for I.P. Fernandes contract.info:eu-repo/semantics/publishedVersio

Acute biphenotypic leukaemia: immunophenotypic and cytogenetic analysis

The incidence of acute biphenotypic leukaemia has ranged from less than 1% to almost 50% in various reports in the literature. This wide variability may be attributed to a number of reasons including lack of consistent diagnostic criteria, use of various panels of antibodies, and the failure to recognize the lack of lineage specificity of some of the antibodies used. The morphology, cytochemistry, immunophenotype and cytogenetics of acute biphenotypic leukaemias from our institution were studied. The diagnostic criteria took into consideration the morphology of the analysed cells, light scatter characteristics, and evaluation of antibody fluorescence histograms in determining whether the aberrant marker expression was arising from leukaemic blasts or differentiated bone marrow elements. Fifty-two of 746 cases (7%) fulfilled our criteria for acute biphenotypic leukaemias. These included 30 cases of acute lymphoblastic leukaemia (ALL) expressing myeloid antigens, 21 cases of acute myelogenous leukaemia (AML) expressing lymphoid markers, and one case of ALL expressing both B- and T-cell associated antigens. The acute biphenotypic leukaemia cases consisted of four major immunophenotypic subgroups: CD2± AML (11), CD19± AML (8), CD13 and/or CD33± ALL (24), CD11b± ALL (5) and others (4). Chromosomal analysis was carried out in 42/52 of the acute biphenotypic leukaemia cases; a clonal abnormality was found in 31 of these 42 cases. This study highlights the problems encountered in the diagnosis of acute biphenotypic leukaemia, some of which may be reponsible for the wide variation in the reported incidence of this leukaemia. We suggest that the use of strict, uniform diagnostic criteria may help in establishing a more consistent approach towards diagnosis of this leukaemic entity. We also suggest that biphenotypic leukaemia is comprised of biologically different groups of leukaemia based on immunophenotypic and cytogenetic findings.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73301/1/j.1365-2141.1993.tb03024.x.pd

Proteomic characterization and biological activities of the mucus produced by the zoanthid Palythoa caribaeorum (Duchassaing & Michelotti, 1860)

Abstract Mucus, produced by Palythoa caribaeorum has been popularly reported due to healing, anti-inflammatory, and analgesic effects. However, biochemical and pharmacological properties of this mucus remains unexplored. Therefore, the present study aimed to study its proteome profile by 2DE electrophoresis and MALDI-TOF. Furthermore, it was evaluated the cytotoxic, antibacterial, and antioxidant activities of the mucus and from its protein extract (PE). Proteomics study identified14 proteins including proteins involved in the process of tissue regeneration and death of tumor cells. The PE exhibited cell viability below 50% in the MCF-7 and S-180 strains. It showed IC50 of 6.9 μg/mL for the J774 lineage, and also, favored the cellular growth of fibroblasts. Furthermore, PE revealed activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus epidermidis (MIC of 250 μg/mL). These findings revealed the mucus produced by Palythoa caribaeorum with biological activities, offering alternative therapies for the treatment of cancer and as a potential antibacterial agent