scholarly journals Towards a Conceptual Understanding of Groundwater Ecology

2012 ◽  
Vol 1 (3) ◽  
pp. 493
Author(s):  
H.O Nwankwoala
Keyword(s):  
Conceptual Understanding ◽  
Chemical Properties ◽  
The Other ◽  
Ecological Communities ◽  
Groundwater Hydrology ◽  
Future Perspectives ◽  
Natural Ecosystems ◽  
Ecological Processes ◽  
Physico Chemical ◽  
Groundwater Ecology

In recent times, ecohydrology and hydroecology are making a mark on theenvironmental agenda, as evidenced by the proliferation of these terms in theacademic literature. There is an increasing recognition that groundwater is essentialto many ecological communities. Surface ecological processes (such asevapotranspiration) significantly impact hydrological responses and relatedhydrochemical function. Thus, the relation of groundwater hydrology to patternsand processes in ecology is a ‘two-way street’ where understanding the feedback ofone to the other serves as a powerful lens through which to evaluate and explainthe functioning of natural ecosystems. Influxes of groundwater to lakes, rivers, andwetlands can change whole-system physico-chemical properties such astemperature and salinity, while also providing more subtle influences onmicroenvironments and their ecological processes. The recognition of thesignificance and power of this tandem has not always been followed with effectiveinterdisciplinary science. The ecological, hydrological, and physico-chemical linksbetween groundwater, surface water and associated ecosystems are seldom fullyunderstood even though true characterization and wise management will require amultidisciplinary approach. This means biologists need to understand theimportance of magnitude and timing of groundwater flows for their system, whichrequires the skills of hydrogeologists to achieve. Hydrogeologists, in turn, mustunderstand how and why groundwater influences ecological processes so that theirexpertise is brought to bear at a scale commensurate to the ecological researchquestion. In this paper therefore, an overview of general concepts, research effortsand future perspectives are presented. More importantly, the paper asserts that it isnot simply the integration of hydrology and ecology that will determine the futureprospects for ecohydrology/hydroecology, but the way in which this integrativescience is conducted.

scholarly journals Studies on Cyanex-272 Complexes of Mg (II), Ca (II) and Fe (III)

1970 ◽  
Vol 42 (4) ◽  
pp. 475-482 ◽  
Author(s):  
M Badrul Islam ◽  
M Zahurul Haque ◽  
N Shamsul Islam
Keyword(s):  
Key Words ◽  
Magnetic Measurements ◽  
Phosphinic Acid ◽  
Chemical Properties ◽  
Decomposition Temperature ◽  
Complex Compounds ◽  
The Other ◽  
Spectral Studies ◽  
Cyanex 272 ◽  
Physico Chemical

Certain complex compounds were synthesized by the interaction of Mg(II), Ca(II) and Fe(III) halides with the solvent extracting reagent, Cyanex-272 i.e. bis (2,4,4- trimethylpentyl) phosphinic acid as ligand. All the prepared complexes have been characterized on the basis of their molar masses, conductivity, magnetic measurements and infrared and electronic spectral studies. The other physico-chemical properties e.g. colour, decomposition temperature have also been ascertained. Key words: Chanex-272 Bangladesh J. Sci. Ind. Res. 42(4), 475-482, 2007

scholarly journals Synthesis and investigation of physico-chemical properties of dicationic ionic liquids

2018 ◽  
Vol 5 (12) ◽  
pp. 181230 ◽  
Author(s):  
Yi-Xin Sun ◽  
Ying-Ying Wang ◽  
Bing-Bing Shen ◽  
Bi-Xian Zhang ◽  
Xiao-Mei Hu
Keyword(s):  
Ionic Liquids ◽  
Heterogeneous System ◽  
Room Temperature ◽  
Chemical Properties ◽  
Homogeneous System ◽  
The Other ◽  
Melting Points ◽  
Good Solubility ◽  
Physico Chemical ◽  
Dicationic Ionic Liquids

A series of dicationic ionic liquids (ILs) including [C 4 (MIM) 2 ][PF 6 ] 2 , [C 5 (MIM) 2 ][PF 6 ] 2 , [C 6 (MIM) 2 ][PF 6 ] 2 and [C 4 (PYR) 2 ][PF 6 ] 2 were synthesized. Their thermal stability and melting points were analysed. It was found that dicationic ILs presented important implications in the design of homogeneous and heterogeneous system with water. A homogeneous system of dicationic ILs with water could be formed at a relatively high temperature and then a heterogeneous system was formed when the solution was cooled to a low temperature. The ILs recovered by altering the temperature were obtained in high percentage yields of [C 4 (MIM) 2 ][PF 6 ] 2 (97.6%), [C 5 (MIM) 2 ][PF 6 ] 2 (97.3%), [C 6 (MIM) 2 ][PF 6 ] 2 (98.0%) and [C 4 (PYR) 2 ][PF 6 ] 2 (94.2%). On the other hand, [C 4 (MIM) 2 ][PF 6 ] 2 and [C 5 (MIM) 2 ][PF 6 ] 2 exhibited good solubility in acetonitrile and acetone. A homogeneous system could be achieved with imidazolium-based ILs with a relatively low amount of water and acetonitrile at room temperature. All of the properties of dicationic ILs have a strong correlation with the nature of dications, the linkage chain and the symmetry of dications. Dicationic ILs may provide a new opportunity for some specific applications in order to enable the effective separation and isolation of products.

scholarly journals Dynamics of the Physico-chemical Properties of Sediments along the Bandama River in the Department of Niakaramadougou, Northern Côte d’Ivoire

2019 ◽  
pp. 739-750
Author(s):  
N’Doufou Gnosseith Huberson Claver ◽  
Kouadio Koffi Hypolithe ◽  
De Lasm Omer Zephir ◽  
Zogoury Eddie Constant Fabrice
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Chemical Properties ◽  
Statistical Analyses ◽  
The Other ◽  
Eastern Shore ◽  
Chemical Parameters ◽  
Sediment Analysis ◽  
Granulometric Analysis ◽  
Physico Chemical

This work focuses on analyzing of physico-chemical properties of sediment affected by frequent floods along the eastern shore of the Bandama River in the department of Niakaramadougou. Sampling was from 4 excavated graves at two positions of studied area, one near the stream and the other one far away from the stream.. Samples collected were analyzed, including texture with granulometric analysis made by the Robinson pipette, and standard sediment analysis methods for measuring organic carbon (OC), nitrogen (N), and other chemical properties including pH, organic matter (OM), and C/N ratio. Statistical analyses were carried out to assess the differences between the physico-chemical parameters at different sampling areas. Differences are significant when comparing areas that are highly affected by floods and areas that are less affected by floods, especially for concentrations of OM, OC and nitrogen. Results show that successive floods are influencing directly the dynamic of physico-chemical properties of the sediments along the shore.

Effect of Microwave Treatment on the Bulk and Nearcontact Properties of Semiconductors of Technical Importance

1996 ◽  
Vol 430 ◽  
Author(s):  
A. A. Belyaev ◽  
A. E. Belyaev ◽  
I. B. Ermolovich ◽  
S. M. Komirenko ◽  
R. V. Konakova ◽  
...  
Keyword(s):  
Schottky Barrier ◽  
Microwave Radiation ◽  
Chemical Properties ◽  
Microwave Treatment ◽  
Schottky Barrier Diode ◽  
The Other ◽  
Semiconductor Materials ◽  
Physico Chemical

AbstractWe investigated the effect of microwave radiation on the physico-chemical properties of some semiconductor materials (CdxHgl-xTe, GaAs) and metal (Al, Pt, Cr, Mo, W) - GaAs Schottky barrier diode structures. From comparison with the results of the other treatments (heat annealing, g-irradiation) some suggestions are made concerning possible mechanisms of the interaction between microwave radiation and the objects studied.

Le biodiesel. I. Caractéristiques, atouts et limites — une synthèse

2008 ◽  
Vol 35 (1) ◽  
pp. 95-106 ◽  
Author(s):  
J. Nikiema ◽  
M. Heitz
Keyword(s):  
Greenhouse Gases ◽  
Fuel Consumption ◽  
Vegetable Oil ◽  
Fossil Fuels ◽  
Raw Materials ◽  
Chemical Properties ◽  
The Other ◽  
Atmospheric Emissions ◽  
Other Hand ◽  
Physico Chemical

Biodiesel, a fuel derived from animal or vegetable oil and fats, is presented in this paper. More specifically, its physico-chemical properties as well as the raw materials and existing standards are described. The advantages, limitations, and future of biodiesel are discussed. Biodiesel offers significant environmental advantages over petrodiesel: its combustion produces fewer atmospheric emissions of pollutants and greenhouse gases; in addition, it biodegrades easily and does not present a major risk during storage. On the other hand, the substitution of biodiesel for petrodiesel usually causes an increase in fuel consumption by engines. In addition, according to various estimates, the price of biodiesel is higher than that of petrodiesel. Nevertheless, biodiesel is easy to produce and, with the anticipated decline in stocks of fossil fuels, it constitutes an interesting substitute that should become increasingly used in the next decade.

scholarly journals Physico-Chemical Properties of Water Yam and Cowpea Flour Blends for Production of Snacks

2020 ◽  
pp. 1-8
Author(s):  
J. O. Nwafor ◽  
A. N. Kanu ◽  
E. C. Kelechukwu ◽  
N. O. Nwohu ◽  
V. N. Ezebuiro
Keyword(s):  
Wheat Flour ◽  
Control Sample ◽  
Chemical Properties ◽  
The Other ◽  
Long Run ◽  
Physico Chemical ◽  
Wheat Products ◽  
Flour Blends ◽  
The Cost ◽  
Water Yam

Aim: The aim of this study is to produce flour from different blend ratio of water yam and cowpea and determination of the physico chemical properties of the snacks produced from the flour blends. Introduction: Snacks are something consumed occasionally for pleasure rather than for nutritive purpose. They are mainly produced by wheat flour. Wheat flour, the main ingredient for production of snacks are imported and thus, the cost of importation of wheat flour eat deep into the Nigeria economy and has placed a considerable burden on the foreign exchange reserve, in the long run causes increase in wheat products. Furthermore, over consumption of wheat products leads to celiac disease associated with immunological disease of the upper intestine triggered by the ingestion of gluten containing cereals. Production of alternative flour to wheat flour can be a welcome idea. Cereal has high nutritional value and it has an appreciable protein content. Study Design: The physico chemical analysis was carried out at the biochemistry laboratory of National Root Crop Research Institute Umudike. Methodology: The water yam (Dioscorea alata) and cowpea (Vigna unguiculata) flours were prepared and they were used for water yam/ cowpea blend at different ratio of (ie 100%:0, 90:10, 80:20, 70:30, 60:40 and 50:50). The 100% water yam was the control sample. Functional properties and proximate composition of the samples were determined. Results and Discussion: According to the result generated from the sensory evaluation, it was discovered that yam/ cowpea blend in the ration of 50:50, 60:40 and 70:30 were more acceptable than the other samples. This can be related to the high content of cowpea in the samples. Conclusion: The yam /cowpea blend in the concentration of 50; 50 was more preferred than the other samples by the panelist.  As a means of nutritional balance yam fortified with cowpea can boost the protein intake of population consuming yam as its main staple.

scholarly journals Physico-chemical Properties Comparison between Released Varieties and Local Germplasm of Sapota (Manilkara zapota)

2019 ◽  
pp. 273-283
Author(s):  
Shekh Tanjina Islam Dola ◽  
Md. Shahidul Islam ◽  
Mahbub Robbani ◽  
Md. Sharifur Rahman
Keyword(s):  
Agricultural Research ◽  
Chemical Properties ◽  
Plant Biotechnology ◽  
The Other ◽  
Carotenoid Content ◽  
Anthocyanin Content ◽  
Sample Collection ◽  
Randomized Design ◽  
Physico Chemical ◽  
Local Germplasm

Aim: Comparison of physico-chemical properties between released varieties and local germplasm of Sapota with a view to selecting the superior germplasm/variety in respect of nutritional quality. Study Design: A laboratory experiment was done by the following Completely Randomized Design (CRD) with 4 replications. Sample Collection: Local germplasms were collected from different homestead of Dumki upazila and six released varieties were collected from Germplasm Center, Department of Horticulture, PSTU and Bangladesh Agricultural Research Institute, Gazipur, Bangladesh. Place and Duration of Study: The study was conducted during March, 2018 to February, 2019 at the Plant Biotechnology Lab and Postharvest Lab, Department of Horticulture, Patuakhali Science and Technology University, Bangladesh. Results: The highest fruit length (4.85 cm), width (4.93 cm), weight (115.33 g), edible portion (92.33%), phenolic content (2.537 mg/100 g) and anthocyanin content (1.807 μg/100 g) were exhibited in local germplasm (G3). The highest carotenoid content (5.320 μg/100 g) was found in local germplasm G3 followed by G1 (5.173 μg/100 g). On the other hand the highest vitamin-C content (11.42 mg/100 g) and carbohydrate percentage (22.99%) were observed in local germplasm G1 and G2 respectively. BARI-3 (V10) exhibited the highest percentage of TSS (21.28%) along with highest peel weight (6.80 g) and the highest percentage of antioxidant (95.80 mg/100 g) was traced in BARI-2 (V9). Conclusion: Based on the selected physico-chemical properties it was revealed that local germplasm (G3) was superior than the other germplasm/varieties. G1, G2, V9 and V10 germplasm/variety were identified as good source of phytochemicals. Based on Physico-chemical properties local germplasm (G3) was better for eating fresh fruit as well as processing than the other germplasms/varieties considered in this research.

scholarly journals Assessment of Free and Total Cyanide Levels in the Water Environment of Shatt Al-Arab

2020 ◽  
Vol 20 (4) ◽  
pp. 880
Author(s):  
Zuhair Ali Abdulnabi
Keyword(s):  
Barbituric Acid ◽  
Colorimetric Method ◽  
Water Environment ◽  
Chemical Properties ◽  
The Other ◽  
Free Cyanide ◽  
Euphrates River ◽  
Tigris River ◽  
Physico Chemical ◽  
South Of Iraq

The concentration of free and total cyanide in waters was measured by using the colorimetric method through complex formation with pyridine-barbituric acid at the wavelength of 578 nm. Ten stations were selected from water surfaces in the south of Iraq. The samples were distributed among two stations, one was on Euphrates River and the other was on Tigris River (before their confluence and formatting of Shatt Al-Arab) and selected seven stations along Shatt Al-Arab River. All the samples were collected from surface water at depth of 10–15 cm and their pH was adjusted to 12 by using sodium hydroxide. The results showed the highest concentration of free cyanide (0.254 mg/L) in station W7 and the lowest concentration in stations W2, W9 and W10, while the highest and lowest concentration of total cyanide (9.962, 0.207 mg/L) were recorded in station W7 and W1 respectively. The standard deviation of all sites (n = 3) of free and total cyanide was calculated and showed 0.007–0.048 and 0.001–0.042 ranges respectively. Furthermore, some of the physico-chemical properties of water were recorded in these stations.

scholarly journals Environmental drivers of soil phosphorus composition in natural ecosystems

2018 ◽  
Vol 15 (14) ◽  
pp. 4575-4592 ◽  
Author(s):  
Leonardo Deiss ◽  
Anibal de Moraes ◽  
Vincent Maire
Keyword(s):  
Chemical Properties ◽  
Parent Material ◽  
Total Carbon ◽  
Environmental Drivers ◽  
Resonance Spectroscopy ◽  
Natural Ecosystems ◽  
Ecological Processes ◽  
Inorganic P ◽  
Soil P ◽  
Environmental Properties

Abstract. Soil organic and inorganic phosphorus (P) compounds can be influenced by distinctive environmental properties. This study aims to analyze soil P composition in natural ecosystems, relating organic (inositol hexakisphosphate, DNA and phosphonates) and inorganic (orthophosphate, polyphosphate and pyrophosphate) compounds with major temporal (weathering), edaphic and climatic characteristics. A dataset including 88 sites was assembled from published papers that determined soil P composition using one-dimensional liquid state 31P nuclear magnetic resonance spectroscopy of NaOH-EDTA extracts of soils. Bivariate and multivariate regression models were used to better understand the environmental properties influencing soil P. In bivariate relationships, trends for soil P compounds were similar for mineral and organic layers but with different slopes. Independent and combined effects of weathering, edaphic and climatic properties of ecosystems explained up to 78 % (inositol hexakisphosphates) and 89 % (orthophosphate) of variations in organic and inorganic P compounds across the ecosystems, likely deriving from parent material differences. Soil properties, particularly pH, total carbon, and carbon-to-phosphorus ratios, over climate and weathering mainly explained the P variation. We conclude that edaphic and climatic drivers regulate key ecological processes that determine the soil P composition in natural ecosystems. These processes are related to the source of P inputs, primarily determined by the parent material and soil forming factors, plant and microbe P cycling, the bio-physico-chemical properties governing soil phosphatase activity, soil solid surface specific reactivity, and P losses through leaching, and finally the P persistence induced by the increasing complexity of organic and inorganic P compounds as the pedogenesis evolves. Soil organic and inorganic P compounds respond differently to combinations of environmental drivers, which likely indicates that each P compound has specific factors governing its presence in natural ecosystems.

scholarly journals Weighted Wiener Indices of Molecular Graphs with Application to Alkenes and Alkadienes

Mathematics ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 153
Author(s):  
Simon Brezovnik ◽  
Niko Tratnik ◽  
Petra Žigert Pleteršek
Keyword(s):  
Linear Regression Analysis ◽  
Chemical Properties ◽  
Wiener Index ◽  
Topological Indices ◽  
The Other ◽  
Multiple Bonds ◽  
Saturated Hydrocarbons ◽  
Simple Graphs ◽  
Boiling Points ◽  
Physico Chemical

There exist many topological indices that are calculated on saturated hydrocarbons since they can be easily modelled by simple graphs. On the other hand, it is more challenging to investigate topological indices for hydrocarbons with multiple bonds. The purpose of this paper is to introduce a simple model that gives good results for predicting physico-chemical properties of alkenes and alkadienes. In particular, we are interested in predicting boiling points of these molecules by using the well known Wiener index and its weighted versions. By performing the non-linear regression analysis we predict boiling points of alkenes and alkadienes.

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