Moisture Sorption Kinetics for Water-Soluble Substances III: Theoretical and Experimental Studies in Air

1983 ◽  
Vol 72 (12) ◽  
pp. 1394-1398 ◽  
Author(s):  
L. Van Campen ◽  
G.L. Amidon ◽  
G. Zografi
Keyword(s):  
Experimental Studies ◽  
Moisture Sorption ◽  
Sorption Kinetics ◽  
Water Soluble

Model-based prediction of the moisture sorption kinetics and humidity-induced collapse for freeze–dried cakes

2022 ◽  
Vol 248 ◽  
pp. 117129
Author(s):  
Kyuya Nakagawa ◽  
Hiroki Kamisaki ◽  
Tetsuo Suzuki ◽  
Noriaki Sano
Keyword(s):  
Moisture Sorption ◽  
Sorption Kinetics ◽  
Model Based ◽  
Freeze Dried

scholarly journals TWO-STEP CROSSLINKING OF PVP/GEL NANOFIBERS

2021 ◽  
Vol 2021 ◽  
pp. 164-170
Author(s):  
H.K. Güler ◽  
F.C. Çallıoğlu
Keyword(s):  
Fiber Diameter ◽  
Experimental Studies ◽  
Water Soluble ◽  
Diameter Distribution ◽  
Sem Images ◽  
Crosslinking Process ◽  
Different Temperatures ◽  
Ft Ir ◽  
Ir Analysis ◽  
Gel Polymers

In this study, it was achieved that crosslinking of PVP/GEL nanofibers with two-steps. Crosslinking is a process highly important for water-soluble polymers in terms of application areas and mechanical properties. Firstly, crosslinking of PVP polymers experimental studies were carried out via heat treatment at different temperatures and times. Then, GEL polymers were crosslinked with GTA vapour at different times. Morphological analysis was carried out via SEM images and chemical characteristics were determined via FT-IR analysis. Moreover, after the crosslinking process, SD and WL values were calculated. All results showed that before crosslinking of SEM images, nanofibers were smooth, fine and without beads. The average fiber diameter is 196 nm and the fiber diameter distribution is quite uniform. After crosslinking of SEM images, it is expected that all nanowebs will turn from fibrous surfaces to membranous. Generally, SD and WL values decrease with crosslinking time increase. According to all of the SEM images, SD and WL values, optimum conditions were determined for PVP as 4 hours at 180oC and for GEL as 24 hours. Lastly, the presence of PVP and GEL polymers in the nanofiber structure was verified chemically with FT-IR analysis.

Temporal changes of mobile forms of 90Sr on Pripyat River floodplain in vicinity of Chornobyl NPP: measurements and risk assessments for river water contamination

2021 ◽  
Author(s):  
Gennady Laptev ◽  
Oleg Voitsekhovych ◽  
Valentyn Protsak ◽  
Mark Zheleznyak ◽  
Kenji Nanba ◽  
...  
Keyword(s):  
Coming Out ◽  
Water Contamination ◽  
Soil Layer ◽  
Experimental Studies ◽  
Water System ◽  
Water Soluble ◽  
Computational Grids ◽  
Exclusion Zone ◽  
Drastic Increase ◽  
Fuel Particles

<p>Since the 1986 Chornobyl accident transport of radionuclides by Pripyat River shares more than 90% of the annual total flux of radioactivity coming out the Chornobyl Exclusion Zone (ChEZ).  90Sr was the main contributor to this flux. In course of time destruction of the accidentally dispersed "fuel particles" leads to increase of mobile, e.g. water-soluble, forms of 90Sr  on territories affected by, while fixation of 137Cs in soil is reflected by significant reduction in 137Cs aquatic transport outside the ChEZ.</p><p>Heavily contaminated floodplain of the Pripyat River, located in vicinity of ChNPP upstream of Yaniv Bridge up to Ukrainian - Belorussian border, was considered as a “hotspot” with highest risks to the Pripyat and Dnipro water contamination due to recurrent flooding of these territories. This was evidently elucidated after the 1991 ice jam event when drastic increase of 90Sr in water was observed. The dikes splitting leftbank floodplain from the Pripyat river channel were constructed in 1992-1993. Yet, it is still important to quantify the amount of 90Sr that can be washed off the floodplain due to potential dike breakage caused by the extreme floods. </p><p>Key parameters used to describe status of radionuclide in reaching equilibrium in soil-water system are the distribution coefficient (Kd) and kinetic rate that is reciprocal of typical time scale of desorption processes. These parameters subsequently were estimated in 1991 on the basis of batch experiment carried out with the soil monoliths sampled from the Pripyat floodplain ( Laptev and Voistekhovich, 1991). Results were used in the 2D model COASTOX for justification the construction of protecting dikes (Zheleznyak at al., 1992).</p><p>To analyze current ability of 90Sr to be washed off the floodplain, soils monoliths were collected in 2020. The experimental studies of the soil cores collected from same location as the monoliths allowed to estimate mobile speciation of 90S and calibrate mass-exchange parameters. Amount of the readily exchangeable forms of 90Sr in soils significantly increased from 10-30% in the first years after the accident up to 65-75% as to 2020. Results of field and laboratory  studies were used for simulation the scenarios of 90Sr washing off the floodplain during the dikes breaks on the basis of contemporary version of COASTOX model, that includes the parallel algorithms for numerical solution of the model equations on the unstructured computational grids for multi CPU and GPU systems. Approaches for the modelling of the secondary release of 90Sr due the rapid destruction of “fuel particles” are considered. Taking into account two concurrent processes - decrease of amount of 90Sr in uppermost soil layer due to decay and downward vertical migration (1), amid increased amount of exchangeable forms of 90Sr (2), one could project subsequent increasing of 90Sr  in Pripyat and Dnipro river waters downstream the source in case of the dike breakage scenarios. On the other hand, computer simulation suggests that the maximal values of the 90Sr concentrations expected to be not higher than the measured ones during the high floods events after the accident.</p><p> </p>

scholarly journals CARBOHYDRATE COUSINIA ANGRENI JUS (ASTERACEAE), ESTABLISHING THE STRUCTURE OF THEIR GLU-COFRUCTANS

2020 ◽  
pp. 41-47
Author(s):  
Kenesh Turdumambetovich Turdumambetov ◽  
Zulayka Sulaimanovna Azhibaeva ◽  
Dzhanymbyu Jorupbekova ◽  
Raisa Andreyevna Goncharova ◽  
Elnura Esenbaevna Ernazarova
Keyword(s):  
Chemical Composition ◽  
Main Product ◽  
Experimental Studies ◽  
13C Nmr Spectroscopy ◽  
Water Soluble ◽  
Special Role ◽  
Plant Materials ◽  
Carbohydrate Complex ◽  
Living Organisms ◽  
Layer Chromatography

Currently, a lot of attention is paid to a number of researchers oligo – and polysaccharides. This is due to their high content in plant materials and the fulfillment of a special role in the development of living organisms, which is of great importance in the production of fructose, sucrose and inulin. Kyrgyzstan has huge reserves of still little-studied, environmentally friendly medicinal and other plant species. The article deals with the study of the chemical composition of the carbohydrate complex in plants of the genus Cousinia angreni Jus. Experimental studies have been carried out to isolate and establish structures of water-soluble polysaccharides and alcohol-soluble oligosaccharides. Glucofructan was isolated from the roots of Cousinia angreni Jus, the structure of individual fractions was studied by methylation, periodic oxidation, paper chromatography, thin-layer chromatography and GLC, IR and 13C-NMR spectroscopy. When compared with witnesses, 2,3,4,6-tetra-O-Me-D-glucose, 1,3,4,6-tetra-O-Me-D-fructose, 3,4,6-tri-O-Me-D-fructose (main product) and trace amounts of 1,3,4-tri-O-Me-D-fructose. The presence of the main product 3,4,6-tri-O-Me-D-fructose indicates the predominance of β-(2→1) bonds. Thus, it was found that glucofructans of the Angren cousin (C. angreni Jus) consist of fructofuranose residues linked by β-(2→1) inulin type bonds.

scholarly journals Application of liquid and water-soluble special fertilizers and biostimulators in agropedocenoses of the forest-steppe zone

2021 ◽  
Vol 37 ◽  
pp. 00033
Author(s):  
L Levshakov ◽  
N Volobueva
Keyword(s):  
High Efficiency ◽  
Leaf Surface ◽  
Experimental Studies ◽  
Growing Season ◽  
Steppe Zone ◽  
First Grade ◽  
Water Soluble ◽  
Forest Steppe ◽  
Apple Trees ◽  
Central Conductor

The value of foliar dressing is presented to achieve the maximum productivity of cultivated crops in agropedocenoses of the forest-steppe zone of the Russian Federation. When cultivating apple orchards in perennial agropedocenoses according to intensive technologies, the optimization of the nutritional regime is one of the most significant factors in obtaining a stably high crop yield of high-quality fruits. To fully provide apple trees with nutrient elements and growth biostimulators during the growing season, it is necessary to use special fat and water-soluble fertilizers and growth biostimulators. Most effectively, they are applied along the leaf surface as a foliar dressing. The leaf surface systems we developed and tested include the introduction of macro-, meso- and microelements and biological stimulating agents. The latter include various groups and types of amino acids, root, growth and development, flowering and setting, ripening and staining stimulating agents. The use of an integrated foliar dressing system has made it possible to provide the most complete need for apple trees with the necessary nutrients and compounds during the entire growing season. The obtained experimental data showed a high efficiency in changing a balanced system of foliar dressing in an intensive apple orchard. Compared to the control, there was a significant increase in the growth activity of the central conductor and fruit wood. Fruit setting rates, caliber and weight of apples and therefore more than 95% of the yield corresponded to the highest and first grade. The yield increased significantly compared to the control, it was from 28 to 66% for varieties and variants. Experimental studies showed high efficiency of foliar dressing with special fertilizers and growth biostimulating agents.

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