scholarly journals DIVERSITY AND SIMILARITY AMONG CYANOBACTERIA ASSEMBLAGES FROM SELECTED AQUATIC ECOSYSTEMS IN SARAWAK USING β –INDICES

2016 ◽  
Vol 1 (1) ◽  
pp. 28-37
Author(s):  
Mohd Nasarudin Harith ◽  
Ruhana Hassan
Keyword(s):  
Aquatic Ecosystem ◽  
Aquatic Ecosystems ◽  
Chemical Properties ◽  
Artificial Lake ◽  
Environmental Characteristics ◽  
Β Diversity ◽  
Physico Chemical ◽  
Wide Range ◽  
Aquaculture Ponds

A study was carried out to evaluate the diversity and similarity of cyanobacterial populations in selected Sarawak aquatic ecosystem using β-indices. Eight stations including aquaculture ponds, cage cultures, waterfall and artificial lake located in Serian, Bau and Batang Ai areas were selected. A total of 43 species belonging to 30 genera of cyanobacteria were recorded. The most distributed pattern among all sampling stations belongs to the genera Chroococcus, Lyngbya, Nostoc and Oscillatoria. The highest β diversity values were found among non-contiguous stations. Besides, no identical or totally different cyanobacteria diversity values were obtained among those non-contiguous stations. The highest β diversity value (0.84) was found among stations with contrasting environmental characteristics. The wide range of β-diversity and similarity suggested that different locations and types of aquatic ecosystems may have variations in physico-chemical properties of the water and eventually lead to the different composition of cyanobacteria.

scholarly journals A review on conductometric studies of electrolytes in mixed solvent systems to understand ion-ion and ion-solvent interactions

2020 ◽  
Vol 10 (3) ◽  
pp. 5355-5360
Keyword(s):  
Mixed Solvent ◽  
Mixed Solvents ◽  
Chemical Properties ◽  
Electrolyte Solutions ◽  
Molar Conductance ◽  
Extensive Literature ◽  
Solvent Interactions ◽  
Physico Chemical ◽  
Wide Range ◽  
Solvent Systems

The study of ion- solvent interaction is of much importance to investigate the nature of different solutions. Measurement of electrical conductivity and evaluation of physico-chemical properties, such as molar conductance, limiting molar conductance, ion-pair association, Walden product etc. shade light on different intermolecular interactions present in electrolyte solutions. Solvation properties can be varied by mixing two or more solvents. An extensive literature survey on conductometric studies has been carried out on different electrolytes dissolved in a wide range of mixed solvent systems. The reported results show that strong solute-solute, solute-solvent and solvent-solvent interactions are responsible for the physico- chemical behavior of a solution in mixed solvents.

scholarly journals Controllable synthesis of pomelo peel-based aerogel and its application in adsorption of oil/organic pollutants

2019 ◽  
Vol 6 (2) ◽  
pp. 181823 ◽  
Author(s):  
Guangyu Shi ◽  
Yizhu Qian ◽  
Fengzhi Tan ◽  
Weijie Cai ◽  
Yuan Li ◽  
...  
Keyword(s):  
High Speed ◽  
Chemical Properties ◽  
Absorption Capacity ◽  
High Porosity ◽  
X Ray Diffraction ◽  
Water Separation ◽  
Physico Chemical ◽  
Wide Range ◽  
Oil Water Separation ◽  
Oil Water

Oil/water separation is a field of high significance as it might efficiently resolve the contamination of industrial oily wastewater and other oil/water pollution. In this paper, an environmentally-friendly hydrophobic aerogel with high porosity and low density was successfully synthesized with renewable pomelo peels (PPs) as precursors. Typically, a series of sponge aerogels (HPSA-0, HPSA-1 and HPSA-2) were facilely prepared via high-speed dispersion, freeze-drying and silanization with methyltrimethoxysilane. Indeed, the physical properties of aerogel such as density and pore diameter could be tailored by different additives (filter paper fibre and polyvinyl alcohol). Hence, their physico-chemical properties including internal morphology and chemical structure were characterized in detail by Fourier transform infrared, Brunauer–Emmett–Teller, X-ray diffraction, scanning electron microscope, Thermal gravimetric analyzer (TG) etc. Moreover, the adsorption capacity was further determined and the results revealed that the PP-based aerogels presented excellent adsorption performance for a wide range of oil products and/or organic solvents (crude oil 49.8 g g −1 , soya bean oil 62.3 g g −1 , chloroform 71.3 g g −1 etc.). The corresponding cyclic tests showed the absorption capacity decreased slightly from 94.66% to 93.82% after 10 consecutive cycles, indicating a high recyclability.

Acute Inhalation Toxicity of Some Halogenated and Non-halogenated Hydrocarbons

1982 ◽  
Vol 1 (3) ◽  
pp. 239-247 ◽  
Author(s):  
D.G. Clark ◽  
D.J. Tinston
Keyword(s):  
Chemical Properties ◽  
Degree Of Saturation ◽  
Halogenated Hydrocarbons ◽  
Inhalation Toxicity ◽  
Saturated Vapour Pressure ◽  
Physico Chemical ◽  
Wide Range ◽  
The Central Nervous System ◽  
Thermodynamic Scale ◽  
Rat Cns

1 The relative potency of effect of a wide range of halogenated and unsubstituted hydrocarbons on the central nervous system (CNS) and the heart of experimental animals have been determined. 2 The chemicals used caused either stimulation or depression of the rat CNS after 10 minutes' inhalation of concentrations ranging from 0.24% to > 80% (v/v), and cardiac sensitization in dogs after 5 minutes' inhalation of 0.12% to approximately 80% (v/v). 3 The toxicity could not be correlated with chemical structure, molecular weight, the presence or absence of various halogen atoms or the degree of saturation, but it was inversely related to the saturated vapour pressure. When the results were expressed on a thermodynamic scale the chemicals had similar potencies at relative saturations of 0.004 to 0.04 4 It is suggested that the effects of these chemicals on the CNS and the heart are probably structurally non-specific, and the chemicals may be regarded as physical toxicants whose effects are predictable from their physico-chemical properties.

scholarly journals Lactoperoxidase: physico-chemical properties, occurrence, mechanism of action and applications

2000 ◽  
Vol 84 (S1) ◽  
pp. 19-25 ◽  
Author(s):  
Klaas D. Kussendrager ◽  
A. C. M. van Hooijdonk
Keyword(s):  
Mammalian Cells ◽  
Bovine Milk ◽  
Chemical Properties ◽  
Mechanisms Of Action ◽  
Industrial Processes ◽  
Physico Chemical ◽  
Lactoperoxidase System ◽  
Wide Range ◽  
Occurrence Mechanism ◽  
Micro Organisms

Lactoperoxidase (LP) is one of the most prominent enzymes in bovine milk and catalyses the inactivation of a wide range of micro-organisms in the lactoperoxidase system (LP-s). LP-systems are also identified as natural antimicrobial systems in human secretions such as saliva, tear-fluid and milk and are found to be harmless to mammalian cells. The detailed molecular structure of LP is identified and the major products generated by the LP-s and their antimicrobial action have been elucidated for the greater part. In this paper several aspects of bovine LP and LP-s are discussed, including physico-chemical properties, occurrence in milk and colostrum and mechanisms of action. Since the introduction of industrial processes for the isolation of LP from milk and whey the interest in this enzyme has increased considerably and attention will be paid to potential and actual applications of LP-systems as biopreservatives in food and other products.

scholarly journals Exploring New Synthetic Strategies for the Production of Advanced Complex Inorganic Nanocrystals

2015 ◽  
Vol 229 (1-2) ◽  
Author(s):  
Neus G. Bastús ◽  
Edgar Gonzalez ◽  
Joan Esteve ◽  
Jordi Piella ◽  
Javier Patarroyo ◽  
...  
Keyword(s):  
Materials Science ◽  
Chemical Properties ◽  
Synthetic Methods ◽  
Colloidal Synthesis ◽  
Hollow Structures ◽  
Physico Chemical ◽  
Composition And Structure ◽  
Wide Range ◽  
Potential Applicability ◽  
New Generation

AbstractThe design of new protocols for the colloidal synthesis of complex nanocrystals (NCs) with advanced functionalities, comprising both hybrid and hollow structures, and the study of their fundamental properties is of paramount importance for the development of a new generation of nanostructured materials. The possibility of tailoring the dimensional regime of NCs, along with its composition and structure, represents a landmark achievement in the control of their unique physico-chemical properties. These properties, alongside with the ability to cheaply produce high quality NCs in fairly large amounts by wet-chemistry techniques, leads to their potential applicability from materials science to nanomedicine. Within this context, this review is focused on describing a successful framework for designing synthetic strategies for the production of advanced complex NCs, integrating the development of new synthetic methods with its structural characterization, monitoring of their properties, and study of its reactivity. As a result, it is expected to provide new routes to produce robust and easy-to-process NCs in a wide range of sizes, shapes and configurations that can be explored to achieve the combination of all degrees of control, aiming to produce a complete and diverse library of material combinations that will expand its applicability in a wide diversity of fields.

scholarly journals Selective bacterial colonization processes on polyethylene waste samples in an abandoned landfill site

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Edoardo Puglisi ◽  
Francesco Romaniello ◽  
Serena Galletti ◽  
Enrico Boccaleri ◽  
Alberto Frache ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Bacterial Colonization ◽  
Chemical Properties ◽  
Microbial Colonization ◽  
Β Diversity ◽  
Physico Chemical ◽  
Plastic Type ◽  
Plastic Wastes ◽  
Ft Raman Spectroscopy ◽  
Degradation Degree

Abstract The microbial colonization of plastic wastes has been extensively studied in marine environments, while studies on aged terrestrial wastes are scarce, and mostly limited to the isolation of plastic-degrading microorganisms. Here we have applied a multidisciplinary approach involving culturomics, next-generation sequencing analyses and fine-scale physico-chemical measurements to characterize plastic wastes retrieved in landfill abandoned for more than 35 years, and to assess the composition of bacterial communities thriving as biofilms on the films’ surfaces. All samples were characterized by different colors but were all of polyethylene; IR and DSC analyses identified different level of degradation, while FT-Raman spectroscopy and X-ray fluorescence further assessed the degradation level and the presence of pigments. Each plastic type harbored distinct bacterial communities from the others, in agreement with the differences highlighted by the physico-chemical analyses. Furthermore, the most degraded polyethylene films were found to host a bacterial community more similar to the surrounding soil as revealed by both α- and β-diversity NGS analyses. This work confirms the novel hypothesis that different polyethylene terrestrial waste samples select for different bacterial communities, and that structure of these communities can be correlated with physico-chemical properties of the plastics, including the degradation degree.

scholarly journals A review on conductometric studies of electrolytes in mixed solvent systems to understand ion-ion and ion-solvent interactions

2020 ◽  
Vol 10 (2) ◽  
pp. 5332-5337
Keyword(s):  
Mixed Solvent ◽  
Mixed Solvents ◽  
Chemical Properties ◽  
Electrolyte Solutions ◽  
Molar Conductance ◽  
Extensive Literature ◽  
Solvent Interactions ◽  
Physico Chemical ◽  
Wide Range ◽  
Solvent Systems

The study of ion- solvent interaction is of much importance to investigate the nature of different solutions. Measurement of electrical conductivity and evaluation of physico-chemical properties, such as molar conductance, limiting molar conductance, ion-pair association, Walden product etc. shade light on different intermolecular interactions present in electrolyte solutions. Solvation properties can be varied by mixing two or more solvents. An extensive literature survey on conductometric studies has been carried out on different electrolytes dissolved in a wide range of mixed solvent systems. The reported results show that strong solute-solute, solute-solvent and solvent-solvent interactions are responsible for the physico- chemical behavior of a solution in mixed solvents.

scholarly journals Impacts of the Physico-chemical Properties of Al-Chibayish Water Marshes on The Biodiversity of Phytoplankton

2021 ◽  
pp. 402-414
Author(s):  
Firas AbdulHassan Jaafar ◽  
Ahmed Saad Abdulwahhab
Keyword(s):  
Aquatic Ecosystems ◽  
Phytoplankton Community ◽  
Chemical Properties ◽  
P Value ◽  
Total Density ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Clear Increase ◽  
And Chemical Properties

Phytoplankton, as one of the most important primary producers in aquatic ecosystems, has been widely used to indicate the health of ecosystems. Nine physico-chemical parameters of water, as well as the phytoplankton community, of Al-Chibayish marsh were studied. Samples were collected from four sites and analyzed every two months from January to October 2019.     Seasonal variations in physical and chemical properties were observed at all sites during the study period. The results indicated that 154 species of phytoplankton were recorded. The highest percentage of species was recorded to be 64.28% for Bacillariophyceae (diatoms) (Centrales 3.24% and Pennales 61.03%), followed by Chlorophyceae (16.23%), Cyanophyceae (11.68%), and Charophyceae and Euglenophyceae (3.24%), while Pyrrophyceae recorded the lowest value (1.29%) The numbers of phytoplankton species were 102, 94, 102, 99 in sites 1, 2, 3 and 4 ,respectively, during the study period.  The total density of phytoplankton ranged from 223.769 cells x103 during January to 2784.693 cells x103 during September in site 2, with a clear increase during March and September, while the lowest number was 223.796 - 237.248 cells x103 in January and May, respectively. The dominance of diatoms was observed in all sites by 49.07% of the total density of phytoplankton, while the lowest abundance was 0.04% for the Pyrrophyceae. The results of the statistical analysis showed significant differences among sites and months, concerning the physical, chemical, and biological factors measured during the study period, at p-value <0.05.

scholarly journals Research on the Physico-Chemical Properties of Soils Locality Dobrosloveni, Olt County for Sustainable Agriculture

2021 ◽  
Vol 9 (2) ◽  
pp. 8
Author(s):  
Anca-Luiza Stănilă
Keyword(s):  
Environmental Factors ◽  
Soil Cover ◽  
Chemical Properties ◽  
Hydrological Regime ◽  
Physico Chemical ◽  
Wide Range ◽  
Low Altitude ◽  
Chemical Properties Of Soils ◽  
Direct Reflection ◽  
Pedogenetic Processes

The studied territory located in the central-western part of Olt County, belongs to the Caracal Plain and extremely little in the Leu-Rotunda Field in the SW part, both as divisions of the Romanati Plain.Locality presents a predominant relief of plain low altitude that is characterized by alluvio-proluvial plains moderately fragmented with local terraces, covered with loess-like deposit but relief of saucer.The soil cover of the territory under study is the direct reflection of all environmental factors, each having a role in the pedogenetic processes. Climate, as a pedogenetic factor, acted by its components, namely: temperature, precipitation, evapotranspiration, global radiation.Forest steppe vegetation was the supply of organic matter and biomass, because the hydrological regime is deficient, but especially the lithological substrate (loess-like complex) to steer solification to types characteristic of the cernisols class.Under the influence of environmental factors and pedogenetic processes within the locality Dobrosloveni it formed a wide range of soils, namely: protisols, cernisols, luvisols and hydrisols.

Research on physico-chemical properties of sugars and sugar crystallization at the University of Chemistry and Technology in Prague

2020 ◽  
pp. 294-298
Author(s):  
Z. Bubnik ◽  
P. Kadlec ◽  
E. Sarka ◽  
V. Pour ◽  
A. Hinkova ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Main Research ◽  
Research Areas ◽  
Research Activities ◽  
Physico Chemical ◽  
Wide Range ◽  
The University ◽  
Physical And Chemical ◽  
Kinetics Of ◽  
And Chemical Properties

This paper represents a summary of most important research activities in sucrose crystallization, in which the Department of Carbohydrates and Cereals, part of the University of Chemistry and Technology (UCT) Prague, has been involved over the last 25 years. A wide range of these projects has been carried out in cooperation with other research institutes, universities and industrial partners. These activities can be divided into four main research areas that are interconnected and support each other. – Physical and chemical properties of sucrose and sugar solutions; – Growth kinetics of sugar crystals in pure and technical sugar solutions; – Simulation and mathematical modeling of new processes and technologies; – Experimental work for industry and cooperation with industrial partners.

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