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Hydrogel polymers can absorb surface active agents from the water environment, which can be practically applied for their removal from waters polluted with detergents. The carried out investigation studies involved the interaction of maleic anhydride copolymers with vinyl ethers when subjected to crosslinking with various crosslinking agents, as well as generated in Poland cationic, anionic and non-ionic surfactants. A very high absorption of cationic surfactant by the hydrogels has been found, which can be applied in the vicinity of plants using such surfactants, e.g. dairies. Poly(vinyl) alcohol crosslinked with glutaraldehyde, was used as hydrogel too, and it doesn't absorb cationic surfactants.
Poly(acrylic acid) (PAA)-based controlled release fertilizers with ammonium nitrate or carbamide were prepared using microwave irradiation. The obtained hydrogels were characterized by swelling behavior and ammonium ion release. It has been found that at higher amounts of crosslinker (N,N`-methylenebisacrylamide), the hydrogel network chains became less flexible. It causes a decrease in the swelling ratio of the hydrogel. The swelling of hydrogels containing ammonium nitrate decreased with increased concentrations of ammonium nitrate. The reason is the presence of ionic groups during agrochemicals’ release in water. These ions prevent water molecules from diffusion into the hydrogels, thus decreasing the swelling capacity of the hydrogels. The release rate is the highest during the first 24 hours, then reaches a plateau.
Brak wody w glebie w okresach letnich, wpływa negatywnie na rozwój roślin. Tam gdzie utrudnione jest stosowanie nawodnień szuka się alternatywnych rozwiązań tego problemu. Jednym z nich jest stosowanie hydrożelu. Poniższe badania miały na celu określenie zmian w możliwościach retencyjnych gleby piaszczystej i torfowo-murszowej na obszarach leśnych po dodaniu hydrożelu. W tym celu posłużono się krzywą sorpcji wody, z której można odczytać wiele ważnych właściwości wodnych gleby. Do wyznaczenia krzywych pF wykorzystano aparat piaskowy firmy Ejikelkamp oraz komory ciśnieniowe Soil Moisture - Santa Barbara USA. Wyniki potwierdzają dużą przydatność stosowania hydrożelu w glebach, w celu zwiększenia wilgotności oraz wydłużenia okresu jej występowania.
The influence of the addition of Potassium Ekosorb to black soil and sandy soil on water content in soils, gas exchange in leaves and yielding of strawberry plants cultivar Senga Sengana, Dukat, Kent and Elsanta was estimated in a field experiment. The obtained results show that the addition of hydrogel increased content of water in both types of soil; however, the effect was on average twice higher in black soil than in sandy soil. The highest stomatal conductance of leaves, photosynthesis and transpiration were observed in plants cultivated in both black and sandy soil with the addition of 3 g dm⁻³ of hydrogel. The addition of higher dose influenced in an ambiguous way on the values of analyzed features of leaves. Yet, regardless of the applied dose of Ekosorb, the stomatal conductance, transpiration and photosynthesis of plants cultivated in black soil were 1.8–2.9 times higher than in sandy soil. The highest yields of fruit on both types of soil were obtained from plants which took advantage of presence of 3 g dm⁻³ of hydrogel. The application of 6 g dm⁻³ influenced on decreasing of plant yields. The weakest reaction on both types of soil occurred in strawberry cultivar Elsanta.
The effects of hydrogels on the soil water retention characteristic curve (WRC) and on the growth indices of Ligusrum ovalifolium (an ornamental plant dominating in the landscape of central Iran) were studied. Various amounts of hydrogels (Suprab A200) were added to soil samples having different percentage of water proportional to potential evapotranspiration data. A factorial experiment was used for statistical analysis of data. The results of the soil water retention model showed that, hydrogel caused the residual water content and saturated water content to increase. Available water content increases to a maximum of about 2.3 times the control. Application of hydrogels can result in significant reduction in the required irrigation frequency particularly for coarse-textured soils. This is an important issue in arid and semi-arid regions of the world for enhancing the water management of coarse-textured soils.
In horticultural production substrates have been sought that would ensure the optimum physical conditions (including aerobic and aquatic) in the root environment. The soil substrate can be modified with synthetic supplements called hydrogels or sorbents. When introduced to the soil, they improve the growth and development of plants, and by interacting with the climatic and soil conditions, they can improve the chemical composition of the vegetables. Research conducted in 2000–2001 aimed at the evaluation of the effect of different type sorbents introduced into the soil and the cultivation date on the concentration of some components in the Charlene lettuce cultivated in a film tunnel. Lettuce was grown in the presence of the following sorbents: potassium Ecosorb, sodium Acrygel, potassium Acrygel and sodium-potassium Acrygel during two terms: spring (April–May) and autumn (September–October). Based on the results of the two-year experiment, a significant effect of both experimental factors on the concentration of some components in the leaves of Charlene lettuce was observed. The concentration of L-ascorbic acid was determined by the type of sorbent used. In the first year of the experiment, the sodium-potassium Acrygel (14.2 mg%) was used to enhance the accumulation of vitamin C. In the second year, the sodium Acrygel (12.5 mg%) enhanced the accumulation of vitamin C. The spring plants accumulated higher levels of total sugars (in 2000 – 1.51% more, in 2001 0.68% more) in comparison to the autumn plants. The lettuce grown in the autumn had high concentrations of nitrates, averaging 2944.3 mg N-NO₃ ·kg fresh mass⁻¹.
W poletkowym doświadczeniu badano bezpośredni wpływ polimeru żelowego AgroAquaGel 800 w dwóch dawkach (0,5 g∙kg-1 i 1 g∙kg-1) na właściwości wodne i powietrzne gleby płowej wytworzonej z lessu ulegającej erozji wodnej. AgroAquaGel 800 jest usieciowanym polimerem poliakryloamidowym o absorpcji wody 800 g∙cm-3. Badania wykazały, że zastosowanie hydrożelu w dawce 1 g∙kg-1 istotnie zmniejszyło gęstość gleby oraz istotnie zwiększyło pełną pojemność wodną, przewodnictwo wodne nasycone, porowatość ogólną, pojemność i przepuszczalność powietrzną w powierzchniowej warstwie badanej gleby.
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