scholarly journals Study of the surface properties of buckwheat flour produced by different enterprises by De-Nui methods and tenzimetric to predict its technological properties

2019 ◽  
Vol 81 (2) ◽  
pp. 202-207
Author(s):  
A. A. Livinskiy ◽  
M. E. Saitova ◽  
S. A. Livinskaya
Keyword(s):  
Experimental Data ◽  
Surface Properties ◽  
Surface Activity ◽  
Adsorption Properties ◽  
Technological Properties ◽  
Production Environment ◽  
Industrial Community ◽  
Colloidal Properties ◽  
Air Liquid Interface ◽  
Buckwheat Flour

The scientific and industrial community of specialists is developing indirect methods for predicting the technological properties of flour, which would reduce economic costs in a production environment. The results of comparing the colloidal properties of 4 samples of different producers of buckwheat flour from steamed cereals and 1 from green are presented. As methods for predicting the technological properties of flour used surface properties. The graphs of the dependence “surface tension at the air-liquid interface - concentration of dissolved substance” were constructed using experimental data obtained by the De Nui method. The surface activity of the compared samples was established by solving equations obtained by mathematical processing of experimental data. The adsorption properties of buckwheat flour samples were studied by the tensimetric method. Based on the study of surface properties, flour samples were arranged in a row according to the manifested colloidal properties. Studies of the surface properties of flour samples from steamed and non-steamed cereals showed that buckwheat flour produced by different enterprises is characterized by various adsorption properties, which should be taken into account during its storage and use in flour products. A sample of unpaired cereal has the highest surface activity, which allows us to recognize it as the best sample. The main influence on the technological advantages of flour is exerted by the fraction of flour with a particle size of up to 50 microns, the amount of which should be 58.69 ± 2%. At a higher content of particles of this fraction, the flour is characterized by reduced surface activity and has a higher hygroscopicity, which negatively affects its technological properties.

The influence of negatively charged silica nanoparticles on the surface properties of anionic surfactants: electrostatic repulsion or the effect of ionic strength?

2020 ◽  
Vol 22 (4) ◽  
pp. 2238-2248 ◽  
Author(s):  
Milad Eftekhari ◽  
Karin Schwarzenberger ◽  
Aliyar Javadi ◽  
Kerstin Eckert
Keyword(s):  
Ionic Strength ◽  
Silica Nanoparticles ◽  
Surface Properties ◽  
Surface Activity ◽  
Aqueous Phase ◽  
Anionic Surfactants ◽  
Electrostatic Repulsion ◽  
Charged Nanoparticles

The presence of negatively charged nanoparticles affects the surface activity of anionic surfactants in an aqueous phase. This effect is mainly caused by the change in ionic strength of the system resulted from the addition of nanoparticles.

scholarly journals Effect of Nitric Acid Modification on Characteristics and Adsorption Properties of Lignite

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 167 ◽  
Author(s):  
Bo Huang ◽  
Guowei Liu ◽  
Penghui Wang ◽  
Xiang Zhao ◽  
Hongxiang Xu
Keyword(s):  
Nitric Acid ◽  
Surface Chemistry ◽  
Pore Structure ◽  
Surface Properties ◽  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Adsorption Properties ◽  
Acid Modification ◽  
X Ray ◽  
Adsorption Performance

The objective of this research was to explore the changes of the pore structure and surface properties of nitric-modified lignite and base the adsorption performance on physical and chemical adsorbent characteristics. To systematically evaluate pore structure and surface chemistry effects, several lignite samples were treated with different concentrations of nitric acid in order to get different pore structure and surface chemistry adsorbent levels. A common heavy metal ion contaminant in water, Pb2+, served as an adsorbate probe to demonstrate the change of modified lignite adsorption properties. The pore structure and surface properties of lignite samples before and after modification were characterized by static nitrogen adsorption, X-ray diffraction, Scanning electron microscope, Fourier transform infrared spectroscopy, zeta potential, and X-ray photoelectron spectroscopy. The experimental results showed that nitric acid modification can increase the ability of lignite to adsorb Pb2+. The adsorption amount of Pb2+ increased from 14.45 mg·g−1 to 30.68 mg·g−1. Nitric acid reacted with inorganic mineral impurities such as iron dolomite in lignite and organic components in coal, which caused an increase in pore size and a decrease in specific surface areas. A hydrophilic adsorbent surface more effectively removed Pb2+ from aqueous solution. Nitric acid treatment increased the content of polar oxygen-containing functional groups such as hydroxyl, carbonyl, and carboxyl groups on the surface of lignite. Treatment introduced nitro groups, which enhanced the negative electrical properties, the polarity of the lignite surface, and its metal ion adsorption performance, a result that can be explained by enhanced water adsorption on hydrophilic surfaces.

Alterations in the surface properties of lung surfactant in the torpid marsupial Sminthopsis crassicaudata

1998 ◽  
Vol 84 (1) ◽  
pp. 146-156 ◽  
Author(s):  
Olga V. Lopatko ◽  
Sandra Orgeig ◽  
Christopher B. Daniels ◽  
David Palmer
Keyword(s):  
Surface Tension ◽  
Surface Properties ◽  
Surface Activity ◽  
Pulmonary Surfactant ◽  
Lung Surfactant ◽  
Lung Compliance ◽  
Equilibrium Surface Tension ◽  
Sminthopsis Crassicaudata

Lopatko, Olga V., Sandra Orgeig, Christopher B. Daniels, and David Palmer. Alterations in the surface properties of lung surfactant in the torpid marsupial Sminthopsis crassicaudata. J. Appl. Physiol. 84(1): 146–156, 1998.—Torpor changes the composition of pulmonary surfactant (PS) in the dunnart Sminthopsis crassicaudata [C. Langman, S. Orgeig, and C. B. Daniels. Am. J. Physiol. 271 ( Regulatory Integrative Comp. Physiol. 40): R437–R445, 1996]. Here we investigated the surface activity of PS in vitro. Five micrograms of phospholipid per centimeter squared surface area of whole lavage (from mice or from warm-active, 4-, or 8-h torpid dunnarts) were applied dropwise onto the subphase of a Wilhelmy-Langmuir balance at 20°C and stabilized for 20 min. After 4 h of torpor, the adsorption rate increased, and equilibrium surface tension (STeq), minimal surface tension (STmin), and the %area compression required to achieve STmin decreased, compared with the warm-active group. After 8 h of torpor, STmin decreased [from 5.2 ± 0.3 to 4.1 ± 0.3 (SE) mN/m]; %area compression required to achieve STmindecreased (from 43.4 ± 1.0 to 27.4 ± 0.8); the rate of adsorption decreased; and STeqincreased (from 26.3 ± 0.5 to 38.6 ± 1.3 mN/m). ST-area isotherms of warm-active dunnarts and mice at 20°C had a shoulder on compression and a plateau on expansion. These disappeared on the isotherms of torpid dunnarts. Samples of whole lavage (from warm-active and 8-h torpor groups) containing 100 μg phospholipid/ml were studied by using a captive-bubble surfactometer at 37°C. After 8 h of torpor, STmin increased (from 6.4 ± 0.3 to 9.1 ± 0.3 mN/m) and %area compression decreased in the 2nd (from 88.6 ± 1.7 to 82.1 ± 2.0) and 3rd (from 89.1 ± 0.8 to 84.9 ± 1.8) compression-expansion cycles, compared with warm-active dunnarts. ST-area isotherms of warm-active dunnarts at 37°C did not have a shoulder on compression. This shoulder appeared on the isotherms of torpid dunnarts. In conclusion, there is a strong correlation between in vitro changes in surface activity and in vivo changes in lipid composition of PS during torpor, although static lung compliance remained unchanged (see Langman et al. cited above). Surfactant from torpid animals is more active at 20°C and less active at 37°C than that of warm-active animals, which may represent a respiratory adaptation to low body temperatures of torpid dunnarts.

scholarly journals Optimisation of rice bran hydolysation using xylanase for xylooligosacchride production

2018 ◽  
Vol 40 (2) ◽  
pp. 259-265
Author(s):  
Nguyen Thi Mai Phuong ◽  
Nguyen Hoa Anh ◽  
Pham Thi Ngoc ◽  
Quach Thi Lien ◽  
Nguyen Thi Bich
Keyword(s):  
Experimental Data ◽  
Food Safety ◽  
Rice Bran ◽  
High Purity ◽  
Appropriate Technology ◽  
Quadratic Model ◽  
Technological Properties ◽  
Soluble Fiber ◽  
Beneficial Bacteria ◽  
Optimized Conditions

Rice bran is a subsidised product of rice processing. It is rich in carbohydrate, especially xylan therefore, has being used for production of soluble fiber oligosaccharide including xylooligosaccharides (XOS). XOS is an oligomer of 2-7 xylose residues and has been proven to be fermented by beneficial bacteria Bifidobacterium and Lactobacillus in colon. The market for XOS is increasing rapidly due to its advantages in biological and technological properties, compared to other common oligosaccharides, such as fructooligosaccharide or galactooligosaccharide. XOS can be produced from rice bran using either chemical or enzymatic hydrolysation technologies. The hydrolyzation using β-1,4-xylanase is commonly used to produce XOS from rice bran. However, an appropriate technology for XOS production from rice bran with high purity and food safety in Vietnam is not available yet. This paper presents new data on optimisation of rice bran hydrolyzation by xylanase to produce XOS using the quadratic model of Box-Behnken. The theoretically optimized conditions for the hydrolyzation are 0.25% enzyme at pH 5.5, temperature of 50°C for 18 hours. Experimental data confirmed the selected condition. The XOS product contains mainly xylobiose, xylotriose and xylotetraose.

scholarly journals Practical application of thermal analysis in the development and study of polymer composites

2019 ◽  
pp. 25-27
Author(s):  
N. V. Antyufeeva, ◽  
A. V. Slavin ◽  
V. A. Bolshakov
Keyword(s):  
Experimental Data ◽  
Thermal Analysis ◽  
Quality Control ◽  
Composite Materials ◽  
Polymer Composites ◽  
Applied Research ◽  
Materials Science ◽  
Technological Properties ◽  
Practical Application ◽  
Manufacturing Enterprises

Modern multifunctional thermoanalytical complexes equipped with computers are inherently mobile laboratories. They are able to solve a wide variety of problems in materials science and technology, both in applied research and in the quality control of products supplied to manufacturing enterprises. Using the example of experimental data obtained in the study of the curing processes of thermosetting semi-finished products (prepregs) of polymer composite materials (PCM), the methodological possibilities of modern devices for thermal analysis are shown. They allow investigating and predicting changes in the technological properties of prepregs in a wide temperature range.

scholarly journals Characterization of Modified and Polymer Coated Alumina Surfaces by Infrared Spectroscopy

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Ashraf Yehia El-Naggar
Keyword(s):  
Infrared Spectroscopy ◽  
Alkali Metal ◽  
Ftir Spectroscopy ◽  
Surface Properties ◽  
Adsorption Properties ◽  
Hydroxyl Groups ◽  
Oh Groups ◽  
Structure Changes ◽  
The Individual

The prepared, modified, and coated alumina surfaces were characterized by infrared spectroscopy (FTIR) to investigate the surface properties of the individual and double modified samples. FTIR helps in reporting the changes occurred in hydroxyl groups as well as the structure changes as a result of thermal treating, hydrothermal treating, silylation treating, alkali metal treating, coating, and bonding with polymer. FTIR spectroscopy represents the strength and abundance of surface acidic OH which determine the adsorption properties of polar and nonpolar sorbents. Generally, all treated samples exhibit decrease of OH groups compared with those of parent ones producing alumina surfaces of different adsorptive powers.

2nd Quadrant Centrifugal Compressor Performance: Part II

2016 ◽  
Author(s):  
Elisabetta Belardini ◽  
Rajeev Pandit ◽  
V. V. N. K. Satish Koyyalamudi ◽  
Dante Tommaso Rubino ◽  
Libero Tapinassi
Keyword(s):  
Experimental Data ◽  
Reverse Flow ◽  
Secondary Flows ◽  
Production Environment ◽  
Absorption Mechanism ◽  
Power Absorption ◽  
Flow Rates ◽  
Performance Curves ◽  
Protection Devices ◽  
Surge Protection

The sizing of surge protection devices for both compressor and surrounding system may require the knowledge of performance curves in 2nd quadrant with a certain level of accuracy. In particular two performance curves are usually important: the pressure ratio trend versus flow rate inside the compressor and the work coefficient or power absorption law. The first curve allows estimating mass flow in the compressor given a certain pressure level imposed by system, while the second is important to estimate the time required to system blow down during ESD (emergency shutdown). Experimental data are routinely not available in the early phase of anti-surge protection devices and prediction methods are needed to provide performance curves in 2nd quadrant starting from the geometry of both compressor and system. In this paper two different approaches are presented to estimate performance curves in 2nd quadrant: the first is a simple 1D approach based on velocity triangle and the second is a full unsteady CFD computation. The two different approaches are applied to the experimental data more deeply investigated in part I by Belardini E.[3]. The measurement of compressor behavior in 2nd quadrant was possible thanks to a dedicated test arrangement in which a booster compressor is used forcing stable reverse flow. The 1D method showed good agreement with experiments at design speed. In off-design condition a correlation for deviation angle was tuned on experimental data to maintain an acceptable level of accuracy. With very low reverse flow rates some discrepancies are still present but this region plays a secondary role during the dynamic simulations of ESD or surge events. The unsteady CFD computation allowed a deeper insight into the fluid structures, especially close to very low flow rates when the deviation of the 1D method and the experimental data is higher. An important power absorption mechanism was identified in the pre-rotation effect of impeller as also the higher impact of secondary flows. These two methods are complementary in terms of level of complexity and accuracy and to a certain extent both necessary. 1D methods are fast to be executed and more easily calibrated to match the available experiments, but they have limited capability to help understanding the underlying physics. CFD is a more powerful tool for understanding fluid structures and energy transfer mechanisms but requires computational times not always suitable for a production environment. 1D method can be used for standard compressor and applications for which consolidated experience have been already gathered while CFD is more suitable during the development of new products or up to front projects in general.

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