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A Method for Measuring the Density of Fine - Grained Solids
Issue:
Volume 7, Issue 2, June 2019
Pages:
27-29
Received:
7 August 2019
Accepted:
29 August 2019
Published:
17 September 2019
Abstract: Density is an inherent property of matter, which plays a very important role in production and life. There are many and relatively simple methods to measure the density of large particulate matter. But the density measurement of fine-grained solid materials is difficult because of the volume measurement. Existing methods require expensive and complex equipment. In order to measure the density of fine solids in a simple, convenient, accurate and rapid manner, This paper uses water to fill the gap between the particles of materials, and then through the conversion of water mass and volume, so as to calculate the volume of materials, so as to calculate the density of fine-grained materials. This paper takes fine-grained phosphate ore as an example to demonstrate the application method of this study. The density of phosphate ore measured by this method is 2.84g/cm³ cubed, which is consistent with the theory. Steel ball and copper chip are also used for verification, and the calculated density is close to the theoretical density, which verifies the accuracy and reliability of this method. Through research and demonstration, this method can make it easy, fast and accurate to measure the density of fine solids, save time and investment, and improve efficiency and efficiency.
Abstract: Density is an inherent property of matter, which plays a very important role in production and life. There are many and relatively simple methods to measure the density of large particulate matter. But the density measurement of fine-grained solid materials is difficult because of the volume measurement. Existing methods require expensive and compl...
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Chemical Speciation, Bioavailability and Risk Assessment of Potentially Toxic Metals in Highway Dusts as Indicators of Highway Pollution
Festus Mayowa Adebiyi,
Abiodun Odunlami Adegunwa,
Odunayo Timothy Ore,
Godswill Ehimengbale Akhigbe
Issue:
Volume 7, Issue 2, June 2019
Pages:
30-37
Received:
11 August 2019
Accepted:
29 August 2019
Published:
17 September 2019
Abstract: This paper investigated concentrations of heavy metals in roadside soil dusts collected along Ife-Ibadan highway in Osun state, Nigeria with the aim of assessing the impacts of vehicular emissions on the environments. The soil dusts were analyzed for total metal concentrations and speciation using Atomic absorption spectrophotometry followed by the evaluation of the metal bioavailability. Results of the total metal analysis indicated that the concentrations of the metals (Pb, Zn, Cu, Fe and Mn) were higher in the contaminated soils than control soils and their WHO maximum allowable limits. The pattern of the total mean concentrations of the metals is in the order: Fe > Cu > Mn > Zn > Pb. The contamination factors of the metals showed that the soils suffered contamination. Analysis of variance (ANOVA) revealed that differences existed significantly in the mean values for all the metals across the study sites. Strong correlation among the metals signified common contamination sources. Cluster analysis produced two major groups: A (Fe and Cu) and B (Zn, Mn and Pb) which is subdivided into two sub-groups viz: Bi (Zn and Mn) and Bii (Pb), indicating similar chemical properties/or sources. The results of the T–test indicated that there were significant differences between the concentrations of the metals in contaminated and control soils. The chemical pools of the metals indicated that the metals were distributed into six fractions with most of the metals residing in the non-residual fractions, suggesting how readily the metals are released into the environment.
Abstract: This paper investigated concentrations of heavy metals in roadside soil dusts collected along Ife-Ibadan highway in Osun state, Nigeria with the aim of assessing the impacts of vehicular emissions on the environments. The soil dusts were analyzed for total metal concentrations and speciation using Atomic absorption spectrophotometry followed by the...
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Contribution to Reactivity, Stability and Selectivity of Monodentated Free Phosphines
Kouadio Valery Bohoussou,
Anoubilé Bénié,
Mamadou Guy-Richard Koné,
N’guessan Yao Silvère Diki,
Koffi Alexis Respect Kouassi,
Nahossé Ziao
Issue:
Volume 7, Issue 2, June 2019
Pages:
38-44
Received:
19 August 2019
Accepted:
2 September 2019
Published:
17 September 2019
Abstract: Phosphines having a high degree of instability in their syntheses, it is necessary to find conditions for obtaining stable products in order to propose new stable and active compounds. It is this concern that responds to the theoretical study of stability and selectivity. This theoretical study of chemical reactivity was carried out using the Density Functional Theory (DFT) method, at the B3LYP/6-31G (p) calculation level. The use of the Frontier Molecular Orbital (FMO) theory, with the Single Orbital Molecular Orbital (SOMO) cation model, made it possible to study the stability of some isomers formed during the addition of free phosphines to the carbon-carbon triple bond. The analysis of these reactivity quantities allowed us to conclude that the presence of halogens on acetylene influences the stability of the stereoisomers during their formation. This stability increases as the electronegativity of the halogen decreases. The large number of π conjugation favors the formation of Cis isomers and the lack or small amount of π conjugation orients the formation of Trans isomers. The nature of the aryl substituent and the number of low electronegativity halogen on the phosphine are capable of promoting the production of stable products.
Abstract: Phosphines having a high degree of instability in their syntheses, it is necessary to find conditions for obtaining stable products in order to propose new stable and active compounds. It is this concern that responds to the theoretical study of stability and selectivity. This theoretical study of chemical reactivity was carried out using the Densi...
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