114 research outputs found
Preparation and characterization of activated carbon fiber (ACF) from cotton woven waste
No full textIn this study, the activated carbon fibers (ACFs) were prepared using cotton woven waste as precursor. The cotton woven waste was first partly dissolved by 80% phosphoric acid and then was pre-soaked in 7.5% diammonium hydrogen phosphate solution. Finally, carbonization and activation were proceeded to get ACF. The optimum preparation conditions, including carbonization temperature, carbonization time, activation temperature and activation time, were chosen by orthogonal design. Nitrogen adsorption/desorption test was conducted to characterize the prepared ACF's pore structure. Fourier transform infrared spectroscopy (FTIR) analysis, X-ray photoelectron spectroscopy (XPS) and environmental scanning electron microscope (ESEM) were employed to characterize its chemical properties and morphology. Adsorption of oilfield wastewater was used to evaluate its adsorption properties. The results show that the prepared ACF is in the form of fiber, with the sectional diameters of 11.7 x 2.6 mu m and the surface area of 789 m(2)/g. XPS results show that carbon concentration of the prepared ACF is higher than that of the commercial ACF. When the prepared ACF dosage is 6 g/L, over 80% of COD and over 70% of chrominance can be removed after 24 h of adsorption at 18 degrees C. (C) 2014 Elsevier B.V. All rights reserved.Chemistry, PhysicalMaterials Science, Coatings & FilmsPhysics, AppliedPhysics, Condensed MatterSCI(E)[email protected]
Heme iron from meat and risk of colorectal cancer: a meta-analysis and a review of the mechanisms involved
No full textRed meat and processed meat intake is associated with a risk of colorectal cancer, a major cause of death in affluent countries. Epidemiological and experimental evidence supports the hypothesis that heme iron present in meat promotes colorectal cancer. This meta-analysis of prospective cohort studies of colon cancer reporting heme intake included 566,607 individuals and 4,734 cases of colon cancer. The summary relative risk of colon cancer was 1.18 [95%C.I.: 1.06-1.32] for subjects in the highest category of heme iron intake compared with those in the lowest category. Epidemiological data thus show a suggestive association between dietary heme and risk of colon cancer. The analysis of experimental studies in rats with chemically-induced colon cancer showed that dietary hemoglobin and red meat consistently promote aberrant crypt foci, a putative pre-cancer lesion. The mechanism is not known, but heme iron has a catalytic effect on (i) the endogenous formation of carcinogenic N-nitroso compounds and (ii) the formation of cytotoxic and genotoxic aldehydes by lipoperoxidation. A review of evidence supporting these hypotheses suggests that both pathways are involved in heme iron toxicit
SUL PROTOCOLLO D’INTESA TRA BANCA D’ITALIA E CONSOB E SUL RIPARTO DI “COMPETENZA” TRA ARBITRO BANCARIO FINANZIARIO (ABF) ED ARBITRO PER LE CONTROVERSIE FINANZIARIE (ACF): CASI E SISTEMA
No full textThe Memorandum of Understanding between the Bank of Italy and Consob on alternative dispute resolution, adopted in March 2020, is a tool for collaboration and coordination, aimed at preventing the onset of interpretative conflicts or operational uncertainties in the delimitation of the respective areas of competence of the ABF and the ACF. The author proposes, also with reference to concrete cases, a first systematic reconstruction of the division of competence" between the two ADR Bodies
Keywords: ADR, Financial Banking Arbitrator (ABF), Arbitrator for Financial Disputes (ACF), Competence, Division of competenc
Reductions in cod and acute toxicity of wastewater generated from refined cotton production using activated carbon fibre (ACF)
No full textActivated carbon fibre is investigated for adsorption of organic pollutants from wastewater generated from refined cotton production. UVVis spectroscopy and FTIR are used to evaluate the chemical changes. Results indicate that the main organic components of refined cotton production wastewater are guaiacyl (G-) and hydroxyphenyl (H-) lignin. It is found that 85% of COD can be removed at 40 degrees C with ACF dosage of 90gL1. The adsorption process is described by the RedlichPeterson isotherm model. The kinetic data follows a pseudo-second-order equation. Over 99% of acute toxicity for Refined Cotton Production (RCP) wastewater has been reduced after adsorption using ACF. (c) 2012 Canadian Society for Chemical EngineeringEngineering, ChemicalSCI(E)EI1ARTICLE61069-10769
Improving access to climate financing for the Pacific Islands
No full textExecutive summary
The United Nations Framework Convention on Climate Change (UNFCCC) commits developed countries to provide assistance to ‘developing countries that are particularly vulnerable to the adverse effects of climate change in meeting the costs of adaptation.’
Although recent commitments of ‘fast-start’ climate funding from partners like Australia, Japan and the European Union are welcome, Pacific Island countries face wider obstacles in accessing appropriate and timely levels of funding for adaptation and mitigation to manage the adverse effects that environmental challenges have on core areas for economic, social and human development.
The experience of Solomon Islands, the first Pacific country to obtain funding from the Kyoto Protocol Adaptation Fund for a project on food security and agricultural production, offers some important lessons for the region.
Access to climate financing could be improved through seeking special access for small island states in financial mechanisms, establishing programs and structures that improve donor coordination and build the capacity of national institutions, developing national climate trust funds and a Pacific Regional Climate Change fund and, most importantly, implementing more targeted action on the ground to assist the most vulnerable communities with concrete adaptation programs
Crosstalk [7] channels AdaBoost INRIA DBN-Isol [22] HOG DeepNet INRIA DBN-Mut [25] HOG DeepNet INRIA/Caltech
No full textfeatures classifier training notes ACF [11] channels AdaBoost INRIA evolution of ChnFtrs [source code] ACF-Caltech [11] channels AdaBoost Caltech evolution of ChnFtrs [source code] ACF+SDt [28] channels AdaBoost Caltech SDt = Stabilized Dt (motion features) AFS [14] multiple linear SVM INRIA accelerated version of FeatSynth AFS+Geo [14] multiple linear SVM INRIA variant of AFS with geometry constraints ChnFtrs [10] channels AdaBoost INRIA updated (see addendum on author website) ConvNet [31] pixels DeepNet INRI
Implications of cell composition and size on the performance of microalgae ultrasonic harvesting
No full text2018 Summer.Includes bibliographical references.Substantial economic challenges exist across the value chain for microalgae-based biofuels and bioproducts. Acoustic harvesting could dramatically reduce harvesting costs and directly address current energy barriers to separating algae from growth media. This technology utilizes ultrasonic standing waves to create an acoustic radiation force that, due to differences in the acoustic properties of the cells and media, causes the microalgae cells to agglomerate and settle out of the solution. The magnitude of the acoustic radiation force is directly related to the cell radius and acoustic contrast factor (ACF), the latter of which is a function of the density and compressibility of the cell. These properties can vary widely depending on the algae species, cultivation conditions, and growth stage—all of which affect the composition of the microalgae cells (e.g., lipid, carbohydrate, protein content). In this work, two methods were used to determine the ACF of microalgal cells: 1) a property measurement approach and 2) a particle tracking approach. The first method involved experimentally measuring the size distribution, density and compressibility of the cells and calculating the ACF. The second method utilized particle tracking velocimetry and a COMSOL Multiphysics model to estimate the ACF. The ACF was characterized, using both techniques, for three species—Chlamydomonas reinhardtii, Nannochloropsis salina, and Tetraselmis chuii—as a function of dynamic cellular composition over a 2-week growth period. For C. reinhardtii the lipid content increased from 26% ± 1% to 40% ± 1% from day 3 to 9, which resulted in a 43% decrease in ACF (0.056 ± 0.003 to 0.032 ± 0.001). For N. salina the lipid content increased from 25% ± 1% to 33% ± 1% from day 3 to 10, which also resulted in a 43% decrease in ACF (0.040 ± 0.002 to 0.023 ± 0.001). For T. chuii the lipid content remained relatively stable (~10%) throughout the growth period so the ACF (~0.3) did not change significantly. ACF decreases as lipid content increases because lipids have a negative ACF in growth media, whereas carbohydrates and proteins have a positive ACF. However, cell size can have a greater impact on an algal strains' responsiveness to acoustic harvesting because the net force is proportional to Φa2. Furthermore, acoustic harvesting works best for large diameter cells, provided that those cells have a nonzero ACF. T. chuii had the largest cell diameter of approximately 12 µm, while C. reinhardtii and N. salina had cell diameters of 8.5 µm and 4.3 µm, respectively. The Φa2 values for T. chuii were approximately 50× higher than the values for N. salina, which is largely due to T. chuii cells having a diameter that is 3× the diameter of N. salina cells. Composition also contributed to the higher Φa2 values for T. chuii since these cells were composed of mostly carbohydrates and had an ACF that was an order of magnitude higher than the ACF of N. salina. This research shows that acoustic harvesting has the potential to positively impact the algal biofuels value chain through the reduction of energy required for harvesting
Salmon juveniles are vulnerable to predation by invasive African clawed frogs in Washington state
No full textThe Pacific Northwest, U.S.A. hosts multiple threatened salmonid species. Predation by introduced species are among the threats salmon face. African clawed frogs (ACF; Xenopus laevis,(Daudin, 1802) ) are a generalist, non-native invasive species recently found in waterways in Washington State, USA. Our goal was to identify if ACF posed a threat to early life stages of Chinook (Oncorhynchus tshawytscha, (Walbaum in Artedi, 1792)), coho (Oncorhynchus kisutch,(Walbaum, 1792)), and chum (Oncorhynchus keta,(Walbaum in Artedi, 1792)) salmon. We conducted feeding trials to discover the foraging propensity of ACF on salmon in three development phases, eyed eggs, alevin, and fry. We predicted that ACF would most readily consume less mobile life stages, based on foraging in other amphibians. Our results showed that ACF consumed all species at all juvenile life stages. The life stage experiencing the highest rates of consumption was salmon fry (72% consumption) and the lowest was eyed eggs (24% consumption). Gravel shelter minimally buffered ACF consumption. Given the growing presence of ACF in proximity to salmon spawning waterways, ACF may pose an additional threat to salmonid recruitment, and require further study to investigate potential interactions.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
Absorbents for water purification: functionalized ordered mesoporous silcate for the removal of 2,4-Dinirophenol and activated carbon filters for the removal of lead (II) from water, 2012
No full textImidazole functionalized ordered mesoporous silicate (MCM-IM) with high surface area was synthesized by the co-condensation of tetraethylorthosilicate, and n-[3 - (triethoxysilyl)propyl ]-4,5-dihydroimidazole, using cetyltrimethvlammonium bromide, CTAB, as a structure-directing agent in basic solution. Nitrogen porosimetry showed that MCM-IM exhibited typical Type IV adsorption-desorption isotherm, narrow average pore size distribution of 2.25 nm, surface area of 343 m2//g, and pore volume of 0.21 cm3 /g. MCM-IM exhibited a high affinity for 2,4-dinitrophenol and an adsorption capacity of 1.85 mmol/g was achieved. The adsorption was pH dependent with significant increase in adsorption capacity below pH 4. The sorption of 2,4-dinitrophenol on MCM-IM followed the Freundlich isotherm model, meaning, non-ideal, multiple, non ideal, multi-layer adsorption on heterogeneous surfaces. Asorption studies of Pb2+ on sulfonated and phosphonated activated carbon filters (ACF) were conducted in batch adsorption experiment. Kinetic experiment showed that lead (II) absorption reached equilibrium after 55 hours. Adsorption isotherm experiments showed that sulfonated activated carbons, S-ACF#1 and S-ACF#2 reached equilibrium capacities of 84.9 mg/g and 73.2 mg/g respectively, while phosphonated activated carbon. PVA-ACF, reached capacity of 66.2 mg/g. The adsorption was pH dependant and increased with pH. The sorption of Pb2+ on S-ACF#1 closely follows the Langmuir isotherm model, which means the sorption is monolayer and homogeneous surface. Sorption of Pb2+ on S-ACF#2 follows both Freundlich and Langmuir models and suggesting monolayer coverage on homogeneous surface or multi-layer on heterogeneous surfaces. Lead adsorption was not significantly affected by the prescene of competing alkali and alkali earth cations. except for Mg2+. In the presence of Mg2+ Pb2+ uptake was below 80%
Predictive validity of ECERS-3 rating thresholds used in Quality Rating and Improvement Systems
No full textThe purpose of this secondary data analysis project is to expand knowledge about the predictive validity of the ERS-3 as used by QIS in the United States by examining state practices in using the ERS-3 to calculate quality ratings for child care programs and by examining the predictive validity of simulated QIS ratings that use ERS-3 for children's learning gains.
This secondary data analysis project was supported by the Administration for Children and Families (ACF) of the U.S. Department of Health and Human Services (HHS) as part of a financial assistance award (Grant #: 90YE0271) totaling $100,000, with 100 percent funded by the ACF/HHS. The contents are those of the author and do not necessarily represent the official views of, nor do they serve as an endorsement by, the ACF/HHS or the U.S. government. For more information, please visit the ACF website, Administrative and National Policy Requirements
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