scholarly journals Characterization of Southwestern Nigeria River Sand for foundry use

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
B.V. Omidiji ◽  
H.A. Owolabi ◽  
D.A. Adetan
Keyword(s):  
Chemical Properties ◽  
Clay Content ◽  
Gray Iron ◽  
River Sand ◽  
Southwestern Nigeria ◽  
Ferrous Metals ◽  
Physical And Chemical ◽  
Moulding Material ◽  
And Chemical Properties

The greater number of castings produced globally are made by using sand casting techniques that utilize sand as major moulding material. This paper characterizes Isasa River sand based on its physical and chemical properties with the aid of Tandem pelletron electrostatic accelerator, trinocular microscope, mechanical sieve shaker, and box furnace, for Foundry application. Results obtained revealed that the River sand has moisture content of 4.30%, clay content of 2.22%, grain fineness number (GFN) of 49, Silica (SiO2) content of 93%, and sintering point of 1400oC. The River sand is a 4-screen sand, having angular grains with medium sphericity. Isasa River sand will be suitable for casting of gray iron and non-ferrous metals, with the addition of binding agent in suitable proportion.

scholarly journals AVALIAÇÃO DA ESTRUTURA ELETRÔNICA DA FASE MONOCLINICA DO ÓXIDO DE NIÓBIO COM BASE NO USO DE DIFERENTES FUNCIONAIS DE DENSIDADE

Química Nova ◽  
2021 ◽  
Author(s):  
Kamila Ody ◽  
João Jesus ◽  
Carlos Cava ◽  
Anderson Albuquerque ◽  
Ary Maia ◽  
...  
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Density Functionals ◽  
Monoclinic Structure ◽  
Functional Theory ◽  
Periodic Models ◽  
Physical And Chemical ◽  
And Chemical Properties

ASSESSMENT OF THE ELECTRONIC STRUCTURE OF THE MONOCLINIC PHASE OF NIOBIUM OXIDE BASED ON THE USE OF DIFFERENT DENSITY FUNCTIONALS. Niobium oxides, Nb2O5, are considered semiconductor materials with very attractive physical and chemical properties for applications in many areas, such as catalysis, sensors, medical, aerospace, etc. Especially, the characterization of Nb2O5-based nanostructures with monoclinic structure has received much attention in recent years. However, despite the great importance of this system, some of its fundamentals properties are still not fully understood. Hence, this work aims to apply the theoretical methodologies through Density Functional Theory (DFT) calculations in periodic models based on the use of different density functionals (like B1WC, B3PW, B3LYP, PBE0, PBESOL0, SOGGAXC, and WC1LYP) to investigate the physical and chemical properties of the monoclinic structure of Nb2O5. The band structures, energy bandgap, density of state, and vibrational properties, as well as order-disorder effects on the monoclinic structure of Nb2O5 are investigated in this study. Our theoretical results show a better agreement with experimental data for the B3LYP functional and hence lead to new perspectives on the deeper physicochemical understanding of the monoclinic Nb2O5. From these computational tools, it is possible to unravel the relations between structure and properties, which may contribute to the future development of new devices and applications based on these materials.

scholarly journals Characterization of gelatins from Nile tilapia skins preserved by freezing and salting

2019 ◽  
Vol 40 (6) ◽  
pp. 2581
Author(s):  
Adriana Cristina Bordignon ◽  
Maria Luiza Rodrigues de Souza ◽  
Eliane Gasparino ◽  
Edson Minoru Yajima ◽  
Jesuí Vergílio Visentainer ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Nile Tilapia ◽  
Saturated Fatty Acids ◽  
Chemical Properties ◽  
Monounsaturated Fatty Acids ◽  
Gel Strength ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

After Nile tilapia skin was preserved using the methods of freezing and dry salting, characteristics of skin gelatin were evaluated with regard to yield, rheological features and physical and chemical properties. Preservation was performed after filleting, at which time skins were either frozen (-18°C) for 7 days or salted (25°C) for 7 days. Although no differences (p > 0.05) were observed with respect to humidity, protein, lipid, ash and calcium levels, gelatin from salted skins had a higher concentration of iron relative to frozen skins. Further, twenty-three fatty acids were detected in salted skins compared with merely three found in skin derived gelatin. Of amino acids found, glycine, alanine, proline and arginine were the most abundant. Hydroxyproline abundance in salted and frozen skin gelatin were 8.76% and 8.71%, respectively. In addition, salted skin gelatins had a greater accumulation of saturated fatty acids and lower rates of monounsaturated fatty acids. Salted skin gelatin had the highest yield (18g × 100g-1), gel strength (200 g) and viscosity (19.02mPas) when compared to the yield (17g × 100g-1), gel strength (12.7g) and viscosity (9.16 mPas) of frozen skins. Results show that gelatin from dry salted skin had the best yield and also had relatively better rheological properties, more iron, and better coloration relative to gelatin obtained from frozen skins of Nile tilapia.

Characterization of Shivirtui Zeolite Modified with Aluminum Oxyhydroxide Nanofibers

2019 ◽  
Vol 942 ◽  
pp. 40-49
Author(s):  
Yulia Murashkina ◽  
Olga B. Nazarenko
Keyword(s):  
Chemical Properties ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Aluminum Oxyhydroxide

Natural zeolite of Shivirtui deposit (Russia) was modified with nanofibers of aluminum oxyhydroxide AlOOH. Aluminum oxyhydroxide nanofibers were produced at the heating and oxidation of aluminum powder with water. The properties of modified zeolite were investigated by means of X-ray diffraction, transmission electronic microscopy, scanning electronic microscopy, low-temperature nitrogen adsorption, thermal analysis, and Fourier transform infrared spectroscopy. It was found that water content in the modified sample of zeolite was about 15 %. Based on the study of the physical and chemical properties, shivirtui zeolite modified with nanofibers of aluminum oxyhydroxide can be proposed for use as a flame-retardant additive to polymers.

scholarly journals Characterization of Engineering Plastics Plasticized Using Supercritical CO2

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 134
Author(s):  
Masaki Watanabe ◽  
Yoshihide Hashimoto ◽  
Tsuyoshi Kimura ◽  
Akio Kishida
Keyword(s):  
Molecular Weight ◽  
Supercritical Co2 ◽  
Chemical Properties ◽  
Molding Process ◽  
Test Pieces ◽  
Engineering Plastics ◽  
Transition Points ◽  
Physical And Chemical ◽  
And Chemical Properties

The purpose of this study was to evaluate the physical and chemical properties of engineering plastics processed using supercritical CO2. First, we prepared disk-shaped test pieces via a general molding process, which were plasticized using supercritical CO2 at temperatures lower than the glass-transition points of engineering plastics. Amorphous polymers were plasticized, and their molecular weight remained nearly unchanged after treatment with supercritical CO2. The mechanical strength significantly decreased despite the unchanged molecular weight. The surface roughness and contact angle increased slightly, and electrical properties such as the rate of charging decreased significantly. These results suggest that supercritical CO2 could be used for a new molding process performed at lower temperatures than those used in general molding processes, according to the required properties.

scholarly journals Synthesis and Characterization of Zirconium Nitride Nanopowders by Internal Gelation and Carbothermic Nitridation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shijiao Zhao ◽  
Jingtao Ma ◽  
Rui Xu ◽  
Xuping Lin ◽  
Xing Cheng ◽  
...  
Keyword(s):  
Carbon Black ◽  
Chemical Properties ◽  
Phase Evolution ◽  
Zirconium Nitride ◽  
Molar Ratio ◽  
Nitridation Process ◽  
Zirconium Compounds ◽  
Physical And Chemical ◽  
And Chemical Properties

AbstractZirconium compounds has been widely attention over the last decades due to its excellent physical and chemical properties. Zirconium nitride nanopowders were synthesized via a simple direct carbothermic nitridation process of internal gel derived zirconia in the presence of nano-sized carbon black. The effects of reaction temperature, dwell time and molar ratio of carbon black to Zr (C/Zr) on the phase composition, grain size and crystal parameters of products were studied. Based upon the analysis of crystallite phase evolution and microstructure characterization, it was found that zirconium oxynitride is intermediate product and then O atoms in oxynitride were extracted by oxygen getter, carbon black. Anion sites were directly replaced by N atoms to form rock-salt type nitride in carbothermic nitridation process.

Physical and Chemical Properties of Mineral in Soils of Cassava Cropping Area: A Case Study in Chonburi Province

2014 ◽  
Vol 979 ◽  
pp. 440-443
Author(s):  
W. Siriprom ◽  
K. Teanchai ◽  
S. Kongsriprapan ◽  
J. Kaewkhao ◽  
N. Sangwaranatee
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Chemical Properties ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Physical And Chemical ◽  
And Chemical Properties

The chemical and physical properties of topsoil and subsoil which collected from the cassava cropping area in Chonburi Province have been investigated. The characterization of both soil sample were used X-Ray Diffraction (XRD), Energy Dispersive X-Ray Fluorescence (EDXRF) while FTIR used to confirmed the formation of intermolecular bonding and Thermo-Gravimetric Analysis (TGA) used for investigated the crystalline. It was found that, the XRD pattern indicated quartz phase. The chemical composition by XRF reported that the soils samples consist of Si, Al, Ca, Fe, K, Mn, Ti, Cr, Zn, Ag and Cu. and TGA results, noticed that the removal of moisture and organics material.

Extraction and characterization of the blue-sensitive visual pigment of the toad Bufo marinus

1987 ◽  
Vol 65 (4) ◽  
pp. 884-887 ◽  
Author(s):  
A. J. Sillman
Keyword(s):  
Vitamin A ◽  
Visual Pigment ◽  
Chemical Properties ◽  
Bufo Marinus ◽  
Physical And Chemical Properties ◽  
Electrophysiological Studies ◽  
Physical And Chemical ◽  
Toad Bufo ◽  
And Chemical Properties

The blue-sensitive visual pigment of the green rods of Bufo marinus was extracted with digitonin. The pigment is present in an amount equal to about 11% that of rhodopsin. It is based on vitamin A1 and exhibits a maximum absorbance of 433 nm. The pigment is labile and readily destroyed by hydroxylamine, regenerates to a much greater degree than does rhodopsin, and is more effectively extracted from the membrane than is rhodopsin. The green rod pigment of Bufo marinus appears to share the same physical and chemical properties as the green rod pigments of other amphibians. Therefore, the results of electrophysiological studies on the green rods of Bufo marinus can be more confidently generalized to other species. The results are discussed in terms of the blue phototaxis that is characteristic of many amphibians.

Physicochemical characterization of nanoparticles and their behavior in the biological environment

2014 ◽  
Vol 16 (29) ◽  
pp. 15053-15067 ◽  
Author(s):  
L. Treuel ◽  
K. A. Eslahian ◽  
D. Docter ◽  
T. Lang ◽  
R. Zellner ◽  
...  
Keyword(s):  
Physicochemical Characterization ◽  
Chemical Properties ◽  
Sufficient Accuracy ◽  
Physical And Chemical Properties ◽  
Solvent Phase ◽  
Biological Environment ◽  
Physical And Chemical ◽  
And Chemical Properties

Whilst the physical and chemical properties of nanoparticles in the gas or idealized solvent phase can nowadays be characterized with sufficient accuracy, this is no longer the case for particles in the presence of a complex biological environment.

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