Steam reforming of biomass gasification gas for hydrogen production: From thermodynamic analysis to experimental validation

ABSTRACT: Biomass gasification produces syngas composed mainly of hydrogen, carbon monoxide, carbon dioxide, methane, water, and higher hydrocarbons, till C4, mainly ethane. The hydrocarbon content can be upgraded into richer hydrogen streams through the steam reforming reaction. This study assessed the steam reforming process at the thermodynamic equilibrium of five streams, with different compositions, from the gasification of three different biomass sources (Lignin, Miscanthus, and Eucalyptus). The simulations were performed on Aspen Plus V12 software using the Gibbs energy minimization method. The influence of the operating conditions on the hydrogen yield was assessed: temperature in the range of 200 to 1100 degrees C, pressures of 1 to 20 bar, and steam-to-carbon (S/C) molar ratios from 0 (only dry reforming) to 10. It was observed that operating conditions of 725 to 850 degrees C, 1 bar, and an S/C ratio of 3 enhanced the streams' hydrogen content and led to nearly complete hydrocarbon conversion (>99%). Regarding hydrogen purity, the stream obtained from the gasification of Lignin and followed by a conditioning phase (stream 5) has the highest hydrogen purity, 52.7%, and an hydrogen yield of 48.7%. In contrast, the stream obtained from the gasification of Lignin without any conditioning (stream 1) led to the greatest increase in hydrogen purity, from 19% to 51.2% and a hydrogen yield of 61.8%. Concerning coke formation, it can be mitigated for S/C molar ratios and temperatures >2 and 700 degrees C, respectively. Experimental tests with stream 1 were carried out, which show a similar trend to the simulation results, particularly at high temperatures (700-800 degrees C).info:eu-repo/semantics/publishedVersio

Efeito da aplicação de produtos enológicos na eliminação de Aflatoxinas em vinho branco

As aflatoxinas, quimicamente definidas como difuranocumarinas, são metabolitos secundários produzidos principalmente pelas espécies Aspergillus flavus e Aspergillus parasiticus. O presente trabalho teve como objetivo estudar a ação de diferentes tipos de produtos enológicos na remoção de aflatoxinas (B1 e B2) presentes no vinho. A eficácia desses produtos na remoção das referidas micotoxinas foi avaliada utilizando vinho artificialmente contaminado com AFB1 e AFB2. O produto enológico que mostrou ser mais eficaz na remoção destas micotoxinas foi a bentonite, com percentagem de remoção de 100%. O caseinato de potássio também se mostrou eficaz, com percentagem de remoção na ordem dos 70 a 80%. Adicionalmente também se avaliou o impacto destes produtos enológicos sobre as características físico-químicas dos vinhos. Os resultados obtidos podem fornecer informações úteis para o sector vitivinícola, na seleção do produto enológico mais apropriado na remoção das aflatoxinas, reduzindo a toxicidade e melhorando simultaneamente a qualidade e segurança alimentar do vinho

An Insight into the Release Kinetics

The authors acknowledge the financial support from Fundação para a Ciência e a Tecnologia (FCT-MEC), Portugal, through the dedicated project (PTDC/EDM-EDM/30828/2017) (BeLive) Publisher Copyright: © 2023 by the authors.This work explores the unique features of magnetic-responsive hydrogels to obtain liposomal hydrogel delivery platforms capable of precise magnetically modulated drug release based on the mechanical responses of these hydrogels when exposed to an external magnetic field. Magnetic-responsive liposomal hydrogel delivery systems were prepared by encapsulation of 1,2-dipalmitoyl-sn-glycero-3-phosphocoline (DPPC) multilayered vesicles (MLVs) loaded with ferulic acid (FA), i.e., DPPC:FA liposomes, into gelatin hydrogel membranes containing dispersed iron oxide nanoparticles (MNPs), i.e., magnetic-responsive gelatin. The FA release mechanisms and kinetics from magnetic-responsive liposomal gelatin were studied and compared with those obtained with conventional drug delivery systems, e.g., free liposomal suspensions and hydrogel matrices, to access the effect of liposome entrapment and magnetic field on FA delivery. FA release from liposomal gelatin membranes was well described by the Korsmeyer–Peppas model, indicating that FA release occurred under a controlled diffusional regime, with or without magnetic stimulation. DPPC:FA liposomal gelatin systems provided smoother controlled FA release, relative to that obtained with the liposome suspensions and with the hydrogel platforms, suggesting the promising application of liposomal hydrogel systems in longer-term therapeutics. The magnetic field, with low intensity (0.08 T), was found to stimulate the FA release from magnetic-responsive liposomal gelatin systems, increasing the release rates while shifting the FA release to a quasi-Fickian mechanism. The magnetic-responsive liposomal hydrogels developed in this work offer the possibility to magnetically activate drug release from these liposomal platforms based on a non-thermal related delivery strategy, paving the way for the development of novel and more efficient applications of MLVs and liposomal delivery systems in biomedicine.publishersversionpublishe

Parallel neural network recognition - a multi-agent system approach

This paper presents and discusses the design and the development of a pattern recognition agent based on neural networks. This agent is part of an intelligent navigation system, providing it with the necessary vision abilities so that it can be placed on a strange environment in order to explore and recognise its structures and specificities. Although similar, the properties of the recognised objects change through time and according to each specific environment. The flexibility required by such recognition process was implemented by several pattern recognition agents. Each agent is based on a neural network and can be trained on-line by a parallel training algorithm to allow an effective real time utilisation

Effect of the application of oenological products on fumonisin B2 (FB2) reduction/removal in contaminated red and white wines

ICFC 2017 - International Conference on Food Contaminants (Book of Abstracts)Fumonisins are mycotoxins produced by species of Fusarium, mainly F. verticillioides and F. proliferatum. Fumonisins have hepatotoxic and nephrotoxic effects in various animals and are also associated to human esophageal cancer [1] thus being classified by the IARC in Group 2 [2]. Chemically, fumonisins are characterized by a 19- or 20-carbon aminopolyhydroxyalkyl chain that is diesterified with propane-1,2,3-tricarboxylic acid groups [3]. Sharing a basic structure, several related groups of fumonisins have been isolated and identified (A, B, C and P). Fumonisins B (FBs) are the major forms found in most food products. Recently they were detected in grapes, musts and wines around the world. It was established an association between Aspergillus niger and the presence of FB2 in grape must and wine. WHO has recommended a maximum tolerable daily intake of 2 mg/kg of body weight to FB1, FB2 and FB3, alone or in combination [4], therefore it is important to prevent and control its occurrence, as well other mycotoxins, in wines [5]. The main objective of this work was to evaluate the ability of different oenological products on FB2 removal of white and red wines. For this purpose, ten commercial oenological fining agents (mineral, synthetic and organic - proteins of animal and vegetable origin) were studied to remove FB2 in white and red wines artificially contaminated with FB2. In addition to the FB2 removal, the effect of these products on wine physicochemical characteristics, namely, flavonoids, non-flavonoids and total phenolic compounds were evaluated. In red wine all products showed low reduction on FB2 removal, being the highest value (30%) achieved by calcium bentonite. The results obtained by the action of these products may be considered as a pioneer approach on wine FB2 reduction/removal, with relevance for wine industry, in order to select the best fining agent to reduce toxicity and consequently to improve wine quality and safety.info:eu-repo/semantics/publishedVersio

Impacto da vivência de rua nas amizades de crianças em idade escolar

OBJETIVO: Trata-se de um estudo para avaliar as relações de amizade em meninos de rua de 7 a 11 anos da cidade de Porto Alegre, RS, Brasil. MÉTODOS: Uma amostra de 30 meninos de rua foi comparada com outra de 51 meninos de 7 a 11 anos que viviam com suas famílias de baixa renda, utilizando-se a Entrevista Sobre Amigos e Companheiros da Cornell (Cornell Interview of Peers and Friends). RESULTADOS: Os dois grupos apresentaram escores globais na entrevista significativamente diferentes, sendo que o grupo de meninos de rua obteve o escore médio mais alto. Da mesma forma, os meninos de rua apresentaram escores de adequação do desenvolvimento, autoestima e habilidades sociais significativamente menores do que os meninos com família. CONCLUSÕES: Levando-se em conta os resultados, é enfatizada a urgência do desenvolvimento de intervenções com as crianças com vivência de rua, especialmente com os meninos de rua.OBJECTIVE: This is a study to evaluate friendships in latency street boys of Porto Alegre, RGS, Brazil. METHODS: A sample of 30 latency street boys was compared with a sample of 51 latency boys living with their low income families, using the Cornell Interview of Peers and Friends (CIPF). RESULTS: The two groups had a significantly different CIPF global scores, and the boys of the street group had the highest mean score. Also, boys of the street had significantly lower developmental appropriateness, self-esteem and social skills scores than boys living with a family. CONCLUSIONS: The urgent need for intervention street children, especially on boys of the street, is emphasized

Remifentanil bolus dose is a safe procedure to control intense noxious stimuli in hypertensive neurosurgical patients

Patients with hypertension may be more prone to develop hypotension as a consequence of opioid administration under general anesthesia. The hemodynamic and bispectral index responses to a remifentanil bolus in neurosurgical hypertensive patients under target-controlled infusion with propofol and remifentanil are addressed. Ten healthy patients and 10 patients with diagnosed hypertension under pharmacological treatment were studied. A 2 µg/kg remifentanil bolus was administered to all patients before skin incision under target-controlled infusion with propofol and remifentanil. Mean arterial pressure, heart rate, and the area under the curve for the bispectral index of the electroencephalogram were analyzed within the groups and compared between them every 30 seconds for two minutes following the bolus. Two minutes after the remifentanil bolus, remifentanil predicted effect-site concentrations reached maximum values of 8.46±0.91 ng/ml and 9.74±1.29 ng/ml in the healthy and hypertensive patients, respectively. Both groups showed a significant decrease in mean arterial pressure, heart rate, and in the area under the curve for the bispectral index. Mean arterial pressure decreased by 17.3±10% and 24±9%, heart rate by 11.1±8% and 12±8%, and the bispectral index by 13±9.2% and 8.6±8.4% in the healthy and hypertensive patients, respectively, 120 seconds after the remifentanil bolus. In a clinical situation in which high remifentanil doses may be required, hypertensive patients are expected to have hemodynamic and bispectral index responses similar to those observed in healthy patients.info:eu-repo/semantics/publishedVersio

A new electromagnetic actuation system on an industrial sewing machine with on-line efficiency monitoring

This paper briefly reviews the study to evaluate the standard presser foot performance and a new actuation set-up to avoid the bouncing and the lack of fabric control. The compression force and displacement waveforms are also presented and widely discussed, as well as the seam’s quality analysis. A spectral (Fast Fourier Transform and Harmonic Distortion) analysis on the obtained waveforms, as well as an Admissible Displacement Limits (ADL) analysis are also described as important techniques to be used to supervise the presser foot force and to monitor the feeding efficiency. ADL have proved to be a better method. Further research should be undertaken in this area, in order to achieve, in a near future, a closed loop control of the presser foot.Fundação para a Ciência e a Tecnologia (FCT

Environmental impact and biological removal processes of pharmaceutically active compounds: The particular case of sulfonamides, anticonvulsants and steroid estrogens

Pharmaceutically active compounds (PhACs) have recently received wide attention in the scientific community due to their extensive consumption for human health and consequent discharge to the environment. Release of PhACs into the environment, even in trace amounts, can cause serious environmental damage. This has become a major concern and their removal from water sources is a priority. Although a few PhACs are efficiently removed in wastewater treatment plants (WWTPs), others remain recalcitrant, and their release is causing damage. In this review, the current state of the art on the biological removal processes of sulfonamide sulfamethoxazole (SMX), the anticonvulsant carbamazepine (CBZ), and steroid estrogens 17-estradiol (E2) and 17-ethinylestradiol (EE2) are discussed, along with their environmental impact. Other systems beyond activated sludge, such as membrane bioreactors, enzymatic membrane reactors, fungi treatments and hybrid systems are also becoming of major interest and are being evaluated for the removal of these compounds. Future perspectives are addressed.Cristiano Leal is recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio