Search results for "Stain"
showing 10 items of 5524 documents
Chitosan-phosphotungstic acid complex as membranes for low temperature H2-O2 fuel cell
2015
Abstract Free-standing Chitosan/phosphotungstic acid polyelectrolyte membranes were prepared by an easy and fast in-situ ionotropic gelation process performed at room temperature. Scanning electron microscopy was employed to study their morphological features and their thickness as a function of the chitosan concentration. The membrane was tested as proton conductor in low temperature H 2 –O 2 fuel cell allowing to get peak power densities up to 350 mW cm −2 . Electrochemical impedance measurements allowed to estimate a polyelectrolyte conductivity of 18 mS cm −1 .
Microalgae cultivation in wastewater: nutrient removal from anaerobic membrane bioreactor effluent
2012
This study investigated the removal of nitrogen and phosphorus from the effluent of a submerged anaerobic membrane bioreactor (SAnMBR) by means of a lab-scale photobioreactor in which algae biomass was cultured in a semi-continuous mode for a period of 42 days. Solids retention time was 2 days and a stable pH value in the system was maintained by adding CO2. Nitrogen and phosphorus concentrations in the SAnMBR effluent fluctuated according to the operating performance of the bioreactor and the properties of its actual wastewater load. Despite these variations, the anaerobic effluent proved to be a suitable growth medium for microalgae (mean biomass productivity was 234 mgl(-1) d(-1)), achie…
Ultrasound-assisted green solvent extraction of high-added value compounds from microalgae Nannochloropsis spp.
2015
Abstract The aim of this work was to investigate ultrasound (US)-assisted green solvent extraction of valuable compounds from the microalgae Nannochloropsis spp. Individual green solvents (water, ethanol (EtOH), dimethyl sulfoxide (DMSO)) and binary mixture of solvents (water-DMSO and water-EtOH) were used for the extraction procedures. Maximum total phenolic compounds yield ( Y p ≈ 0.33) was obtained after US pre-treatment ( W = 400 W, 15 min), being almost 5-folds higher compared to that found for the untreated samples and aqueous extraction ( Y p ≈ 0.06). The highest yield of total chlorophylls ( Y c ≈ 0.043) was obtained after US ( W = 400 W, 7.5 min), being more than 9-folds highe…
Preparation of Pd coated anodic alumina membranes for gas separation media
2007
Different procedures of Pd electroless deposition onto anodic alumina membranes were investigated to form a dense metal layer covering pores. The main difficulty was related to the amorphous nature of anodic alumina membranes, determining low chemical stability in solutions at pH > 9, where Pd plating works more efficiently. As a consequence, it was necessary to find the operative conditions allowing Pd deposition without damaging the membrane: to reduce alumina dissolution, the plating bath was buffered at pH 8.5 by addition of either NaHCO 3 or Na 2 B 4 O 7 ·H 2 O. Acceptable conversion of Pd was found after a deposition time of 3 min. Single and multiple deposition steps (each lasting 3 …
Staining mitochondria in Saccharomyces cerevisiae.
1969
After testing various procedures (amidoblack 10B, acid fuchsin-methyl blue, Luxol fast blue MBS-phloxine, toluidine blue O, Jams green B and pinacyanol), three stains can be recommended for staining both types of mitochondria (globose and threadlike) in the cells of Saccharomyces cerevisiae: (1) 0.1% solution of amidoblack 10B in citrate buffer (pH 3.0) for 10 min; (2) 0.01% solution of toluidine blue O in phosphate buffer (pH 6.0) for 30 min; (3) 0.01% solution of Janus green B in distilled water (pH 5.6) for 30 min. The latter stain is most specific because its staining reaction depends upon the action of the mitochondrial enzyme cytochrome c oxidase. Yet, low concentrations and short inc…
Keyhole limpet hemocyanin (KLH), I: Reassociation from Immucothel® followed by separation of KLH1 and KLH2
1997
Abstract Studies of keyhole limpet hemocyanin (KLH) normally require purification of functional complexes directly from living animals. An alternative procedure is described wherein a commercial preparation of KLH which is fully dissociated into its subunits (Immucothel®, biosyn Arzneimittel GmbH) is reassociated in the presence of a high concentration of calcium and magnesium. The reassociation products, when observed by electron microscopy, consist of didecamers, multidecamers and flexible tubules of varying length. The two forms of KLH described previously and designated KLH1 and KLH2, are present in the reassocated mixture as homo-oligomers/polymers and can be separated by selective dis…
Flow-cytometric enumeration of reticulocytes with the new fluorochrome 1′,3′-diethyl-4,2′-quinolylthiacyanine
1992
Several flow-cytometric methods for reticulocyte enumeration in whole blood have been developed, with different degrees of practical use. Recently, a new fluorochrome, 1′,3′-diethyl-4,2′-quinolylthyacianine (DEQTC) was proposed in a brief report, as an alternative to thiazole orange for reticulocyte counting. We have evaluated the usefulness of this fluorescent stain by assessing the optimal conditions for the flow-cytometric analysis, and by comparing in double-blind assays the quantitative results of this technique with those obtained by manual counting with brilliant cresyl blue. Our results show that flow cytometry with DEQTC is highly correlated to the manual method (r=0.95–0.99), supp…
Toxicity of binary mixtures of Cu, Cr and As to the earthworm Eisenia andrei
2020
AbstractChromated copper arsenate (CCA) mixtures were used in the past for wood preservation, leading to large scale soil contamination. This study aimed at contributing to the risk assessment of CCA-contaminated soils by assessing the toxicity of binary mixtures of copper, chromium and arsenic to the earthworm Eisenia andrei in OECD artificial soil. Mixture effects were related to reference models of Concentration Addition (CA) and Independent Action (IA) using the MIXTOX model, with effects being related to total and available (H2O and 0.01 M CaCl2 extractable) concentrations in the soil. Since only in mixtures with arsenic dose-related mortality occurred (LC50 92.5 mg/kg dry soil), it wa…
Electronic properties and corrosion resistance of passive films on austenitic and duplex stainless steels
2018
Abstract Passive films were grown at constant potential in acidic (pH∼2) and alkaline (pH∼13) solutions on chromium, AISI 304L, AISI 316L and Duplex stainless steels. Passive films on chromium grow following a high field mechanism considering the presence of dissolution phenomena. According to the photoelectrochemical characterization, passive films on Cr have a bandgap of 3.4 eV when formed in acidic solution, and of 2.4 eV when formed in alkaline solution due to the formation of Cr(OH)3. These films result to be poorly stable against anodic dissolution due to a very anodic flat band potential. Conversely, impedance and photoelectrochemical measurements proved that passive films on stainle…
The Sustainability of Reclaimed Asphalt as a Resource for Road Pavement Management through a Circular Economic Model
2019
The transition of the road engineering industry to a circular way of doing business requires more efficient and sustainable resources, energy, and waste management. The rates in which reclaimed asphalt is being recycled or reused in the asphalt mixture production process constitutes a crucial parameter in this transition. This paper aims at establishing a further step towards the combined circularity and sustainability of asphalt pavements, by introducing a framework for quantifying their Material Circularity Index. The framework is based on the methodology proposed by the Ellen MacArthur Foundation and accordingly tailored for the context of asphalt pavements. This study, thus, attempts to…