Search results for "Mixed"
showing 10 items of 783 documents
Numerical investigation on dissimilar Friction Stir Welding of Aluminum and Magnesium sheets
2014
Bioinspired Metal-Organic Frameworks in Mixed Matrix Membranes for Efficient Static/Dynamic Removal of Mercury from Water
2020
The mercury removal efficiency of a novel metal-organic framework (MOF) derived from the amino acid S-methyl-L-cysteine is presented and the process is characterized by single-crystal X-ray crystallography. A feasibility study is further presented on the performance of this MOF and also that of another MOF derived from the amino acid L-methionine when used as the sorbent in mixed matrix membranes (MMMs). These MOF-based MMMs exhibit high efficiency and selectivity in both static and dynamic regimes in the removal of Hg2+ from aqueous environments, due to the high density of thioalkyl groups decorating MOF channels. Both MMMs are capable to reduce different concentration of the pollutant to …
Order and disorder in mixed metal linear chains: The homo and heterobimetallic EDTA (M(H2O)4OIOII)[M?(EDTA)] � 6H2O complexes (M = Mg, Mn, Co, Zn and…
1984
Polymetallic solid solutions of the ethylenediaminetetracetic acid (EDTA) and six divalent metal ions exist in the range: MgαMnβCoγZnδNieCuτ(EDTA) · 6H2O where α + β + γ + δ + e + τ=2, 0⩽τ⩽1, 0⩽γ,e,δ⩽2, 0⩽α, β⩽1. This type of structure is characterized by the presence of two different octahedral carboxylate-bridged coordination sites forming infinite zig-zag chains. Visible and i.r. spectra and t.g.a. analysis show that there is occupational preference for the two coordination sites in the crystalline structure. Due to this preference, and also to the structural features, the heterobimetallic MM′(EDTA) · 6H2O compounds constitute a structurally new class of materials which can be described …
Selective Gas and Vapor Sorption and Magnetic Sensing by an Isoreticular Mixed-Metal–Organic Framework
2012
A novel isoreticular oxamato-based manganese(II)-copper(II) open metal-organic framework H(2)O@iso1 featuring a pillared square/octagonal layer structure with alternating open and closed octagonal pores has been rationally prepared. The open-framework topology is responsible for a large selectivity in the separation of small gas (CO(2) over CH(4)) and vapor molecules (CH(3)OH over CH(3)CN and CH(3)CH(2)OH). H(2)O@iso1 displays a long-range three-dimensional ferromagnetic ordering with a drastic variation of the critical temperature as a function of the guest molecule [T(C)2.0 K (CO(2)@iso1 and CH(4)@iso1) and T(C) = 6.5 (CH(3)OH@iso1) and 21.0 K (H(2)O@iso1)].
Corrigendum to “Selective oxidative dehydrogenation of ethane on MoVTeNbO mixed metal oxides catalysts” [J. Catal. 225 (2) (2004) 428–438]
2005
The Impact of COVID-19 on Sport in Twitter: A Quantitative and Qualitative Content Analysis
2021
The spread of the SARS-CoV-2 virus has transformed many aspects of people’s daily life, including sports. Social networks have been flooded on these issues. The present study aims to analyze the tweets produced relating to sports and COVID-19. From the end of January to the beginning of May 2020, over 4,000,000 tweets on this subject were downloaded through the Twitter search API. Once the duplicates, replicas, and retweets were removed, 119,253 original tweets were analyzed. A quantitative–qualitative content analysis was used to study the selected tweets. Posts dynamics regarding sport and exercise evolved according to the COVID-19 pandemic and subsequent lockdown, shifting from consideri…
Economic evaluations of ergonomic interventions preventing work-related musculoskeletal disorders: a systematic review of organizational-level interv…
2017
Background Work-related musculoskeletal disorders (WMSD) represent a major public health problem and economic burden to employers, workers and health insurance systems. This systematic review had two objectives: (1) to analyze the cost-benefit results of organizational-level ergonomic workplace-based interventions aimed at preventing WMSD, (2) to explore factors related to the implementation process of these interventions (obstacles and facilitating factors) in order to identify whether economic results may be due to a successful or unsuccessful implementation. Methods Systematic review. Studies were searched in eight electronic databases and in reference lists of included studies. Companio…
Assessing first-year engineering students' pre-university mathematics knowledge: preliminary validity results based on an item response theory model
2020
The importance of students’ prior knowledge to their current learning outcomes cannot be overemphasised. Students with adequate prior knowledge are better prepared for the current learning materials than those without the knowledge. However, assessment of engineering students' prior mathematics knowledge has been beset with a lack of uniformity in measuring instruments and inadequate validity studies. This study attempts to provide evidence of validity and reliability of a Norwegian national test of prior mathematics knowledge using an explanatory sequential mixed-methods approach. This approach involves use of an item response theory model followed by cognitive interviews of some students …
A Mixed Methods Study to Examine the Influence of CLIL on Physical Education Lessons: Analysis of Social Interactions and Physical Activity Levels
2020
Physical Education is often selected for applying multilingual initiatives through the use of a content and language integrated learning (CLIL) approach. However, it is still unclear whether the introduction of such an approach might entail losing the essence of physical education and distorting its basic purposes. The aim of this study is to analyze the impact of CLIL on physical education lessons. Given the purpose of this study, a mixed methodological approach based on a sequential exploratory design divided into two different phases is used. We begin with initial qualitative data collection (phase I), consisting of the analysis of interviews with 12 participants (8 teachers and 4 studen…
Life cycle assessment of solar communities
2020
Abstract This study presents the comparison of the life cycle performance of two different urban energy systems, applied to a large mixed-use community, in Calgary (Canada). The two systems investigated consist of an energy efficient conventional system, using heat pumps for heating, cooling and domestic hot water; the second design widely deploys solar thermal panels coupled to district heating infrastructure and a borehole seasonal thermal storage. The analysis is based on the Life Cycle Assessment methodology and includes the stages of raw materials and energy supply, system manufacturing, use stage of the systems, generation and use of energy on-site, maintenance and components’ substit…