scholarly journals Fabrication of Gum Arabic-Graphene (GGA) Modified Polyphenylsulfone (PPSU) Mixed Matrix Membranes: A Systematic Evaluation Study for Ultrafiltration (UF) Applications

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 542
Author(s):  
Alaa Mashjel Ali ◽  
Khalid T. Rashid ◽  
Ali Amer Yahya ◽  
Hasan Sh. Majdi ◽  
Issam K. Salih ◽  
...  
Keyword(s):  
Fourier Transforms ◽  
Thermal Characteristics ◽  
Gum Arabic ◽  
Evaluation Study ◽  
Membrane Properties ◽  
Systematic Evaluation ◽  
Mixed Matrix Membranes ◽  
Solute Flux ◽  
Xrd Patterns ◽  
Modified Graphene

In the current work, a Gum, Arabic-modified Graphene (GGA), has been synthesized via a facile green method and employed for the first time as an additive for enhancement of the PPSU ultrafiltration membrane properties. A series of PPSU membranes containing very low (0–0.25) wt.% GGA were prepared, and their chemical structure and morphology were comprehensively investigated through atomic force microscopy (AFM), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM). Besides, thermogravimetric analysis (TGA) was harnessed to measure thermal characteristics, while surface hydrophilicity was determined by the contact angle. The PPSU-GGA membrane performance was assessed through volumetric flux, solute flux, and retention of sodium alginate solution as an organic polysaccharide model. Results demonstrated that GGA structure had been successfully synthesized as confirmed XRD patterns. Besides, all membranes prepared using low GGA content could impart enhanced hydrophilic nature and permeation characteristics compared to pristine PPSU membranes. Moreover, greater thermal stability, surface roughness, and a noticeable decline in the mean pore size of the membrane were obtained.

Design and Evaluation of Accessible Collaborative Writing Techniques for People with Vision Impairments

2022 ◽  
Vol 29 (2) ◽  
pp. 1-42
Author(s):  
Maitraye Das ◽  
Anne Marie Piper ◽  
Darren Gergle
Keyword(s):  
Present Article ◽  
Collaborative Writing ◽  
Evaluation Study ◽  
Systematic Evaluation ◽  
Collaborative Systems ◽  
Text To Speech ◽  
Screen Reader ◽  
Academic Organizations ◽  
Collaboration Awareness ◽  
Writing Tools

Collaborative writing tools have been used widely in professional and academic organizations for many years. Yet, there has not been much work to improve screen reader access in mainstream collaborative writing tools. This severely affects the way people with vision impairments collaborate in ability-diverse teams. As a step toward addressing this issue, the present article aims at improving screen reader representation of collaborative features such as comments and track changes (i.e., suggested edits). Building on our formative interviews with 20 academics and professionals with vision impairments, we developed auditory representations that indicate comments and edits using non-speech audio (e.g., earcons, tone overlay), multiple text-to-speech voices, and contextual presentation techniques. We then performed a systematic evaluation study with 48 screen reader users that indicated that non-speech audio, changing voices, and contextual presentation can potentially improve writers’ collaboration awareness. We discuss implications of these results for the design of accessible collaborative systems.

scholarly journals Pebax/ionic liquid modified graphene oxide mixed matrix membranes for enhanced CO2 capture

2018 ◽  
Vol 565 ◽  
pp. 370-379 ◽  
Author(s):  
Guoji Huang ◽  
Ali Pournaghshband Isfahani ◽  
Ansori Muchtar ◽  
Kento Sakurai ◽  
Binod Babu Shrestha ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Graphene Oxide ◽  
Co2 Capture ◽  
Mixed Matrix Membranes ◽  
Mixed Matrix ◽  
Modified Graphene Oxide ◽  
Modified Graphene ◽  
Matrix Membranes

scholarly journals Synthesis of polyethersulfone (PES)/GO-SiO2 mixed matrix membranes for oily wastewater treatment

2019 ◽  
Vol 81 (7) ◽  
pp. 1354-1364 ◽  
Author(s):  
Maryam B. Alkindy ◽  
Vincenzo Naddeo ◽  
Fawzi Banat ◽  
Shadi W. Hasan
Keyword(s):  
Wastewater Treatment ◽  
Water Flux ◽  
Oil Refinery ◽  
Membrane Properties ◽  
Mixed Matrix Membranes ◽  
Mixed Matrix Membrane ◽  
Oily Wastewater ◽  
Mixed Matrix ◽  
Phase Inversion Technique ◽  
Oily Wastewater Treatment

Abstract The treatment of oily wastewater continues to pose a challenge in industries worldwide. Membranes have been investigated recently for their use in oily wastewater treatment due to their efficiency and relatively facile operational process. Graphene oxide (GO) and silica (SiO2) nanoparticles have been found to improve membrane properties. In this study, a polyethersulfone (PES) based GO-SiO2 mixed matrix membrane (MMM) was fabricated, using the phase inversion technique, for the treatment of oil refinery wastewater. The PES/GO-SiO2 membrane exhibited the highest water flux (2,561 LMH) and a 38% increase in oil removal efficiency by comparison to a PES membrane. Compared to PES/GO and PES/SiO2 membranes, the PES/GO-SiO2 MMM also displayed the best overall properties in terms of tensile strength, water permeability, and hydrophilicity.

Chemical incorporation of epoxy-modified graphene oxide into epoxy/novolac matrix for the improvement of thermal characteristics

2019 ◽  
Vol 30 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Hamidreza Ebrahimi ◽  
Hossein Roghani-Mamaqani ◽  
Mehdi Salami-Kalajahi ◽  
Sina Shahi ◽  
Amin Abdollahi
Keyword(s):  
Graphene Oxide ◽  
Thermal Characteristics ◽  
Modified Graphene Oxide ◽  
Modified Graphene

scholarly journals Exploring the Effect of Iron Metal-Organic Framework Particles in Polylactic Acid Membranes for the Azeotropic Separation of Organic/Organic Mixtures by Pervaporation

Membranes ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 65
Author(s):  
Asma Msahel ◽  
Francesco Galiano ◽  
Martina Pilloni ◽  
Francesca Russo ◽  
Amor Hafiane ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Metal Organic Framework ◽  
Vacuum Pressure ◽  
Membrane Properties ◽  
Mixed Matrix Membranes ◽  
Mechanical Resistance ◽  
Mixed Matrix ◽  
Metal Organic ◽  
Organic Framework ◽  
Matrix Membranes

A microporous carboxylate metal-organic framework MIL-100 Fe was prepared as submicron particles by microwave-assisted hydrothermal synthesis (Fe-MOF-MW). This product was explored, for the first time, for the preparation of polylactic acid (PLA) mixed matrix membranes. The produced MOF was characterised by powder X-ray diffraction (PXRD), environmental scanning electron microscopy (ESEM) as well as by thermogravimetric analysis (TGA) and nitrogen adsorption/desorption. The effect of different Fe-MOF-MW concentrations (0.1 and 0.5 wt%) on the membrane properties and performance were evaluated. These membranes were used in the pervaporation process for the separation of methanol/methyl tert-butyl-ether mixtures at the azeotropic point. The influence of the feed temperature and vacuum pressure on the membrane performance was evaluated and the results were compared with PLA pristine membranes. Moreover, the produced membranes have been characterised in terms of morphology, MOF dispersion in the polymeric membrane matrix, wettability, thickness, mechanical resistance and swelling propensity. The presence of Fe-MOF-MW was found to have a beneficial effect in improving the selectivity of mixed matrix membranes towards methanol at both concentrations. The highest selectivity was obtained for the PLA membranes embedded with 0.5 wt% of Fe-MOF-MW and tested at the temperature of 25 °C and vacuum pressure of 0.09 mbar.

scholarly journals Structural, Magnetic Properties and Hyperthermia Efficiency of MF/CuAl2O4 Multiferroic Nanocomposite

2021 ◽  
Author(s):  
Roumaih Roumaih ◽  
Ismail Abd-elrahem ◽  
Shaban I. Hussein
Keyword(s):  
Magnetic Properties ◽  
Fourier Transforms ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Heating Efficiency ◽  
Structure Changes ◽  
Transmission Electron ◽  
Standard Value ◽  
Xrd Patterns ◽  
Two Stages

Abstract The multiferroic MF/CuAl2O4 (MF= CoFe2O4, NiFe2O4, MgFe2O4, and ZnFe2O4) was prepared using two stages of the sol-gel method. X-ray Diffraction (XRD), the Fourier transforms infrared absorption (FT-IR) and High-resolution Transmission Electron Microscope (HR-TEM) were used to examine the structure of all samples. From the XRD patterns, two standards of cubic spinels structure (CuAl2O4 + MF) were observed. The analysis of FTIR spectra confirmed the formation of the chemical and molecular structure changes in the MF/CuAl2O4. HR-TEM images showed a uniform particle distribution with a nanoscale of all samples. The magnetic properties were studied from the hysteresis loops using a vibrating sample magnetometer (VSM) and the magnetization M (T) by the Faraday balance method. All samples exhibited typical ferrimagnetic behavior, except for ZnF/CuAl recorded superparamagnetic. Curie temperature (TC) for all nanocomposites obtained from M(T) protocols, which is lower than the standard value of MF nanoferrites. The heating efficiency of all samples was investigated by measuring the Specific Absorption Rate (SAR) parameter. The SAR of NiF/CuAl showed a maximum value as well as saturation magnetization (Ms) and lowest coercivity (Hc) value.

scholarly journals Optical, Thermal and Radiation Shielding Properties of B2O3 - NaF - PbO – BaO - La2O3 Glasses

2021 ◽  
Author(s):  
Kh. S. Shaaban
Keyword(s):  
Thermal Characteristics ◽  
Glass Network ◽  
Radiation Shielding ◽  
Bandgap Energy ◽  
Optical Parameters ◽  
Molar Polarizability ◽  
Non Linear ◽  
Optical Bandgap Energy ◽  
Xrd Patterns

Abstract The techniques of melt-quenching were used to generate 53B2O3 - 2NaF - 27PbO – (20 - x)BaO - La2O3 (0 ≤ x ≥ 15) glass system. XRD patterns have established the amorphous character of glass samples. There is clear evidence of the role of La2O3 modifier in the glass network. The thermal characteristics were identified to increase with an increase in La2O3 content. Increasing La2O3 increases the linear and non-linear optical bandgap energy and the Urbach energy. By adding La2O3 to the glass samples, the refractive index, molar polarizability, polarizability, and optical basicity are increased. Theoretically, the bulk modulus and the glass transition temperature increase because of the increase in bond strength. The number of bonds per unit increased with the increase in La2O3 content because of the modifier character of La2O3 in the glass samples. Multiple optical parameters (ε∞), (εo), X(1), (X(3)) and (n2) as a function of linear and non-linear Eopt were obtained. The extent of shielding in this article was examined with the increment in La2O3 at the expense of BaO. The results correspond with similar studies conducted previously.

scholarly journals Computational tools to detect signatures of mutational processes in DNA from tumours: a review and empirical comparison of performance

2018 ◽  
Author(s):  
Omichessan Hanane ◽  
Severi Gianluca ◽  
Perduca Vittorio
Keyword(s):  
Somatic Mutations ◽  
Empirical Evaluation ◽  
Simulated Data ◽  
Evaluation Study ◽  
Systematic Evaluation ◽  
Mutational Signatures ◽  
Computational Tools ◽  
Probability Profile ◽  
Mathematical Algorithms ◽  
Mutational Processes

AbstractMutational signatures refer to patterns in the occurrence of somatic mutations that reflect underlying mutational processes. To date, after the analysis of tens of thousands of genomes and exomes from about 40 different cancers types, 30 mutational signatures characterized by a unique probability profile across the 96 mutation types have been identified, validated and listed on the COSMIC (Catalogue of Somatic Mutations in Cancer) website. Simultaneously with this development, the last few years saw the publication of several concurrent methods (mathematical algorithms implemented in publicly available software packages) for either the quantification of the contribution of prespecified signatures (e.g. COSMIC signatures) in a given cancer genome or the identification of new signatures from a sample of cancer genomes. A review about existing computational tools has been recently published to guide researchers and practitioners in conducting their mutational signatures analysis, however, other tools have been introduced since its publication and, to date, there has not been a systematic evaluation and comparison of the performance of such tools. In order to fill this gap, we carry on an empirical evaluation study of all available packages to date, using both real and simulated data.

scholarly journals Cross-species cell-type assignment of single-cell RNA-seq by a heterogeneous graph neural network

2021 ◽  
Author(s):  
Xingyan Liu ◽  
Qunlun Shen ◽  
Shihua Zhang
Keyword(s):  
Neural Network ◽  
Single Cell ◽  
Cell Types ◽  
Evaluation Study ◽  
Systematic Evaluation ◽  
Homologous Gene ◽  
Cell Type ◽  
Evolutionary Mechanisms ◽  
Comparative Analyses ◽  
Type Assignment

Cross-species comparative analyses of single-cell RNA sequencing (scRNA-seq) data allow us to explore, at single-cell resolution, the origins of cellular diversity and the evolutionary mechanisms that shape cellular form and function. Here, we aimed to utilize a heterogeneous graph neural network to learn aligned and interpretable cell and gene embeddings for cross-species cell type assignment and gene module extraction (CAME) from scRNA-seq data. A systematic evaluation study on 649 pairs of cross-species datasets showed that CAME outperformed six benchmarking methods in terms of cell-type assignment and model robustness to insufficiency and inconsistency of sequencing depths. Comparative analyses of the major types of human and mouse brains by CAME revealed shared cell type-specific functions in homologous gene modules. Alignment of the trajectories of human and macaque spermatogenesis by CAME revealed conservative gene expression dynamics during spermatogenesis between humans and macaques. Owing to the utilization of non-one-to-one homologous gene mappings, CAME made a significant improvement on cell-type characterization cross zebrafish and other species. Overall, CAME can not only make an effective cross-species assignment of cell types on scRNA-seq data but also reveal evolutionary conservative and divergent features between species.

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