Seasonal Variations in some Physical and Chemical Properties of Water from an Undisturbed African Tropical Catchment Area (Guma Valley, Sierra Leone)

1988 ◽  
Vol 73 (1) ◽  
pp. 107-112
Author(s):  
Obed S. M. Mtada
Keyword(s):  
Sierra Leone ◽  
Seasonal Variations ◽  
Catchment Area ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

The Abiotic Frame and Adaptations to Cope with Abiotic Constraints

2017 ◽  
Author(s):  
Christer Brönmark ◽  
Lars-Anders Hansson
Keyword(s):  
Catchment Area ◽  
Large Scale ◽  
Oxygen Supply ◽  
Chemical Properties ◽  
Nutrient Status ◽  
Physical And Chemical Properties ◽  
Wind Turbulence ◽  
Abiotic Constraints ◽  
Physical And Chemical ◽  
And Chemical Properties

This chapter draws up the abiotic frame for organisms set by the physical and chemical properties of a specific ecosystem. The abiotic frame is a combination of several features, including wind, turbulence, temperature and light, but also by nutrient status, pH and oxygen supply. Based on this abiotic frame, large-scale movements, as well as stratification phenomena of lakes are discussed. The importance of the surrounding land, that is, the catchment area, is stressed; specifically, how the catchment area may strongly affect the physical and chemical features of the lake or pond. In addition, this chapter explains how lakes and ponds have been, and still are, formed in the landscape and how organisms handle the abiotic frame.

scholarly journals Physical and Chemical Properties of Surface Waters in the Różany Strumień Catchment in The Years 1988–2012

2017 ◽  
Vol 36 (1) ◽  
pp. 33-49
Author(s):  
Monika Okońska ◽  
Katarzyna Pietrewicz
Keyword(s):  
Surface Waters ◽  
Catchment Area ◽  
Anthropogenic Impacts ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Physical And Chemical Properties ◽  
Hydrogen Carbonate ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract The Różany Strumień catchment located in the north of Poznań is an example of a small anthropogenically-induced catchment. The main aim of this study is to analyse the variability of selected physical and chemical properties of surface waters in the catchment area in the years 1988-2012. It was found that surface waters in the catchment can be classified as hard and very hard, with slightly basic pH. The deterioration of Różany Strumień water quality concerns chemical oxygen demand, conductivity, chlorides, sodium, ammonia nitrogen and nitrite nitrogen concentrations. The authors of the study have noticed a decrease in the amount of phosphates and sulphates in the water. As observed, the hydrogeochemical type of water changed from calcium-hydrogen carbonate-sulphate into calcium-sodium-hydrogen carbonate-sulphate-chloride. Changes in water chemistry are probably a result of anthropogenic impacts, and they can be associated with the transformation of land use in the catchment area, i.e. the ongoing urbanization of the area.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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