PROPRIETES CHIMIQUES ET PHYSIQUES DE LA MATIERE ORGANIQUE NONDIALYSABLE EXTRAITE DE QUATRE PODZOLS DU QUEBEC

1972 ◽  
Vol 52 (1) ◽  
pp. 1-17 ◽  
Author(s):  
ANTONIO GONZALEZ ◽  
GÉRARD HUBERT
Keyword(s):  
Chemical Properties ◽  
Great Similarity ◽  
Metallic Ions ◽  
Carbon And Nitrogen ◽  
Molecular Weights ◽  
Carbon And Nitrogen Content ◽  
Physical And Chemical ◽  
Humic Fractions ◽  
Molecular Weight Fractions

The physical and chemical properties of non-dialysable (>48 A) humic and fulvic fractions of four podzols from the Province of Quebec were studied. Extraction was made with 0.1 M sodium pyrophosphate. Analysis of the fractions showed that, in spite of a prolonged dialysis, considerable quantities of metallic ions remained bound to compounds of high molecular weights. The humic fraction showed, in general, a carbon and nitrogen content sensibly more even than the fulvic fraction. In the spodic horizon, humic fractions have a very similar carbon content. It is also in this horizon that are found the highest percentages of iron and aluminium. The distribution of the principal nitrogen compounds in each fraction was studied after acid hydrolysis. A great similarity in the distribution of the nitrogen was found, independently of its origin (horizon or profile). It has not been possible to find a relation between profiles, from the study of acid groups (carboxilic or phenolic). Absorption spectra with ultraviolet, visible, and infrared radiations were studied. The characterization of a profile from optical properties of high molecular weight fractions was particularly difficult, considering the great similarity between observed spectra. Differences in iron bound to the fulvic fraction were observed by means of electrophoresis. The behaviour of the humic and fulvic fractions towards H+ and Ca2+ ions was also studied.

scholarly journals Synthesis of Hydrophilic Polyelectrolyte as Draw Solute for Forward Osmosis Process

2017 ◽  
Vol 20 (1) ◽  
Author(s):  
W. Khongnakorn ◽  
W. Bootluck
Keyword(s):  
Functional Group ◽  
Forward Osmosis ◽  
Chemical Properties ◽  
Solute Flux ◽  
Physical And Chemical Properties ◽  
Molecular Weights ◽  
Physical And Chemical ◽  
Lower Diffusion ◽  
And Chemical Properties

Synthesis and characterization of hydrophilic polyelectrolyte was performed in this work and used as draw solute for forward osmosis (FO) process. The effect of different ratios of acrylic acid (AA) and benzoyl peroxide (B) on the properties of polyelectrolyte was studied in this work. The physical and chemical properties of draw solution (DS) such as pH, conductivity, osmolality, viscosity, molecular weights and functional group were investigated. Results showed that the solution osmolality increased with increasing AA/B ratio. Self-synthesized polyelectrolytes with different molecular weights (MWs) were further correlated with its solution osmolality. The self-synthesized polyelectrolytes of PAA-K and PAA-Na showed an increasing of hydrophilic functional groups such as –OH or COOH. PAA-Na with lower MW and high osmotic pressure in the aqueous solution is found to exhibit a lower reverse solute flux during FO process. Meanwhile for the polyelectrolyte with higher MW, higher viscosity and lower diffusion coefficient were reported.

scholarly journals α-Crystallin. The isolation and characterization of distinct macromolecular fractions

1971 ◽  
Vol 124 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Abraham Spector ◽  
Lu-Ku Li ◽  
Robert C. Augusteyn ◽  
Arthur Schneider ◽  
Thomas Freund
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Chemical Difference ◽  
Molecular Weights ◽  
Isolation And Characterization ◽  
Different Populations ◽  
Molecular Weight Fractions

α-Crystallin was isolated from calf lens periphery by chromatography on DEAE-cellulose and gel filtration. Three distinct populations of macromolecules have been isolated with molecular weights in the ranges approx. 6×105−9×105, 0.9×106−4×106and greater than 10×106. The concentration of macromolecules at the molecular-weight limits of a population are very low. The members of the different populations do not appear to be in equilibrium with each other. Further, in those molecular-weight fractions investigated, no equilibrium between members of the same population was observed. The population of lowest molecular weight comprises 65–75% of the total material. The amino acid and subunit composition of the different-sized fractions appear very similar, if not identical. The only chemical difference observed between the fractions is the presence of significant amounts of sugar in the higher-molecular-weight fractions. Subunit molecular weights of approx. 19.5×103and 22.5×103were observed for all α-crystallin fractions.

scholarly journals Recent Progress in the Synthesis and Characterization of Diarylethene-based MOFs

2014 ◽  
Vol 70 (a1) ◽  
pp. C1223-C1223
Author(s):  
Jason Benedict ◽  
Ian Walton ◽  
Dan Patel ◽  
Jordan Cox
Keyword(s):  
Chemical Properties ◽  
Building Blocks ◽  
Synthesis And Characterization ◽  
Next Generation ◽  
Design Synthesis ◽  
Thermally Induced ◽  
Potential Applications ◽  
External Stimuli ◽  
Physical And Chemical

Metal-organic Frameworks (MOFs) remain an extremely active area of research given the wide variety of potential applications and the enormous diversity of structures that can be created from their constituent building blocks. While MOFs are typically employed as passive materials, next-generation materials will exhibit structural and/or electronic changes in response to applied external stimuli including light, charge, and pH. Herein we present recent results in which advanced photochromic diarylethenes are combined with MOFs through covalent and non-covalent methods to create photo-responsive permanently porous crystalline materials. This presentation will describe the design, synthesis, and characterization of next-generation photo-switchable diarylethene based ligands which are subsequently used to photo-responsive MOFs. These UBMOF crystals are, by design, isostructural with previously reported non-photoresponsive frameworks which enables a systematic comparison of their physical and chemical properties. While the photoswitching of the isolated ligand in solution is fully reversible, the cycloreversion reaction is suppressed in the UBMOF single crystalline phase. Spectroscopic evidence for thermally induced cycloreversion will be presented, as well as a detailed analysis addressing the limits of X-ray diffraction techniques applied to these systems.

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.

The Application of 57FE Mössbauer Spectroscopy to the Characterization of Nuclear Waste Forms

1981 ◽  
Vol 6 ◽  
Author(s):  
Paul G. Huray ◽  
M. T. Spaar ◽  
S. E. Nave ◽  
J. M. Legan ◽  
L. A. Boatner ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Chemical Properties ◽  
Electronic Charge ◽  
Chemical Information ◽  
Waste Forms ◽  
Charge States ◽  
Physical And Chemical ◽  
Nuclear Waste Forms

The electronic charge states and site symmetries of the radioactive ions incorporated in nuclear waste forms are of considerable importance in determining the physical and chemical properties of these materials. An in situ characterization of these ions is, unfortunately, often difficult – especially when a mixture of charge states and local crystal symmetries exist. The application of Mbssbauer spectroscopy represents a powerful technique for obtaining solid state chemical information.

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