Dystrophy or eutrophy: phytoplankton and physicochemical parameters in the functioning of humic lakes

Author(s):  
Małgorzata Poniewozik ◽  
Władysława Wojciechowska ◽  
Michał Solis

AbstractThe studies were carried out in six humic lakes (Polesie Region, Eastern Poland) in order to present a role of phytoplankton in relation to physical and chemical parameters characteristic of particular processes. On the basis of physical and chemical properties of waters (SD, colour, pH, EC, Ca2+, DIC, DOC), these lakes are divided into three groups: dystrophic (Lakes Orchowe and Płotycze), humoeutrophic (Lakes Brudzieniec and Pereszpa) and mesoeutrophic (Lakes Moszne and Długie). The occurrence of dystrophication, humoeutrophication or eutrophication processes is clearly reflected in the phytoplankton composition and its abundance, as well as its biomass. In both dystrophic and humoeutrophic lakes, flagellates dominated in the phytoplankton. Among them, the invasive species Gonyostomum semen was very abundant. Mesoeutrophic lakes were characterized by other phytoplankton composition, mainly by non-flagellate species (green algae).

2015 ◽  
Vol 17 (26) ◽  
pp. 16733-16743 ◽  
Author(s):  
Lipeng Zhang ◽  
Quan Xu ◽  
Jianbing Niu ◽  
Zhenhai Xia

Defects are common but important in graphene, which could significantly tailor the electronic structures and physical and chemical properties.


2015 ◽  
Vol 46 (6) ◽  
pp. 954-968
Author(s):  
M. Gromadzka ◽  
A. Wolanin ◽  
M. Żelazny ◽  
Ł. Pęksa

This paper describes research on two of the largest karst springs in Poland's Tatra Mountains – Goryczkowe and Bystrej Górne – both located in the Tatra National Park. The aim of the study was to determine the potential contributing area for the Bystrej Gorne Spring. Research has shown that seasonal changes in the physical and chemical properties of water in both springs followed a similar pattern; however, observed differences were not statistically significant. Additionally, research has shown that the potential contributing area is different than that previously identified by other researchers. The chemical composition of water obtained from each spring was dominated by Ca2+ and HCO−3, and included small amounts of the biogenic NO−3 ion. The highest values of the measured physical and chemical parameters were noted in winter, while the lowest values were noted in spring and summer. Principal component analysis was used to assess the physical and chemical parameters of water obtained from both studied springs. Water dilution and catchment biological activity were identified as two key processes affecting physical and chemical properties of karst spring water. Several differences were identified between the springs – water temperature, pH, mineralization, as well as the concentration of Mg2+, HCO−3, and SO24.


2020 ◽  
Vol 222 ◽  
pp. 01004
Author(s):  
A.A. Sadov ◽  
L.A. Novopashin ◽  
L.V. Denezhko ◽  
Yu.B. Cherkasov

The purpose of the article is to evaluate physical and chemical properties of mixtures based on ricinic oil and bioethanol, followed by determining the optimal concentrations of elements and the processing method. The study used methods for calculating the physical and chemical parameters of complex multicomponent mixtures with subsequent experimental verification of the accepted assumptions and hypotheses validity. The results of the study showed that heat treatment of ricinic oil by heating up to 330 °C allows for a chemical reaction of modification of ricinic oil (dehydration and splitting) in order to obtain products suitable for mixing with petroleum, and thanks to additional ultrasound treatment, it is possible to provide a higher degree of dispersion of emulsified products and increase the shelf life. The presented analytical method for evaluating and optimizing the physical and chemical properties of mixtures allows for preliminary optimization of their composition and excluding unsuitable mixtures for further research. Laboratory studies aimed at determining physical and chemical parameters of mixtures confirm the results of theoretical studies and according to the results, mixtures with a content of biological components of no more than 60% are identified, which correspond to the indicators of diesel fuel and are recommended for use.


Author(s):  
S.M.J. Stockdill ◽  
G.G. Cossens

RESEARCH has shown that pasture production on soils without earthworms is limited to considerably less than the true potential. Increased production with beneficial earthworms is associated with pronounced changes in the physical and chemical properties of the soil. Infiltration rate is increased, moisture is conserved and the risk of soil erosion is reduced


2021 ◽  
Vol 3 (1) ◽  
pp. 1-31
Author(s):  
Benjamin Gabriel Poulson ◽  
Qana A. Alsulami ◽  
Abeer Sharfalddin ◽  
Emam. F. El Agammy ◽  
Fouzi Mouffouk ◽  
...  

Due to their unique structural, physical and chemical properties, cyclodextrins and their derivatives have been of great interest to scientists and researchers in both academia and industry for over a century. Many of the industrial applications of cyclodextrins have arisen from their ability to encapsulate, either partially or fully, other molecules, especially organic compounds. Cyclodextrins are non-toxic oligopolymers of glucose that help to increase the solubility of organic compounds with poor aqueous solubility, can mask odors from foul-smelling compounds, and have been widely studied in the area of drug delivery. In this review, we explore the structural and chemical properties of cyclodextrins that give rise to this encapsulation (i.e., the formation of inclusion complexes) ability. This review is unique from others written on this subject because it provides powerful insights into factors that affect cyclodextrin encapsulation. It also examines these insights in great detail. Later, we provide an overview of some industrial applications of cyclodextrins, while emphasizing the role of encapsulation in these applications. We strongly believe that cyclodextrins will continue to garner interest from scientists for many years to come, and that novel applications of cyclodextrins have yet to be discovered.


The physical and chemical properties of the Earth’s crust have been shaped by the interaction of endogenic and exogenic processes during the course of history. The nature of this interaction between 4.6 and 3.8 Ga B.P. is still uncertain. Since then the nature of erosional processes, of transport, deposition, and the cycling of sea water through the ocean crust, has remained reasonably constant. However, variations in the nature and in the intensity of these processes due to changes in the endogenic cycle, due to biological evolution and probably due to variations in the input of solar energy have left easily discernible marks in the nature of the crust.


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