scholarly journals The effects of light and temperature on microalgal growth and nutrient removal: an experimental and mathematical approach

RSC Advances ◽  
2016 ◽  
Vol 6 (27) ◽  
pp. 22896-22907 ◽  
Author(s):  
Ana L. Gonçalves ◽  
José C. M. Pires ◽  
Manuel Simões
Keyword(s):  
Mathematical Model ◽  
Nutrient Removal ◽  
Combined Effect ◽  
Mathematical Approach ◽  
Effect Of Light

A mathematical model describing the combined effect of light and temperature on microalgal growth was developed.

scholarly journals PHOTOKINESIS AND TONIC EFFECT OF LIGHT IN UNIONICOLA

1932 ◽  
Vol 16 (2) ◽  
pp. 349-355 ◽  
Author(s):  
John H. Welsh
Keyword(s):  
Light Intensity ◽  
Simple Relation ◽  
Combined Effect ◽  
Direct Proportion ◽  
Water Mite ◽  
Locomotor Muscles ◽  
Leg Movement ◽  
Changing Light ◽  
Effect Of Light

1. The speed of progression of Unionicola, a water mite, is influenced by light; and over a certain range increases as a function of the light intensity. 2. The relation between speed and light intensity is not a simple one, as the speed of progression is due to the combined effect of amplitude of steps and frequency of leg movement. 3. The amplitude of stride increases in direct proportion to the logarithm of the light intensity, while the frequency of stepping has no such simple relation to intensity. 4. The change in length of stride with changing light intensity indicates a tonic effect of light on the locomotor muscles. Such an effect has been observed previously in studies of orientation, due to unequal illumination, which produces changes in posture.

scholarly journals Introducing a Conditional Ghost Correction Into the Vector Method

1984 ◽  
Vol 6 (2) ◽  
pp. 117-123 ◽  
Author(s):  
H. Schaeben
Keyword(s):  
Mathematical Model ◽  
Quadratic Programming ◽  
Optimization Problem ◽  
Linear Equations ◽  
Singular System ◽  
Orientation Distribution ◽  
Mathematical Approach ◽  
System Of Linear Equations ◽  
Vector Method ◽  
The Mathematical Model

The concept of conditional ghost correction is introduced into the vector method of quantitative texture analysis. The mathematical model actually chosen here reduces the texture problem to one of quadratic programming. Thus, a well defined optimization problem has to be solved, the singular system of linear equations governing the correspondence between pole and orientation distribution being reduced to a set of equality constraints of the restated texture problem. This new mathematical approach in terms of the vector method reveals the modeling character of the solution of the texture problem provided by the vector method completely.

The Olifantsfontein Nutrient Removal Plant

1990 ◽  
Vol 22 (7-8) ◽  
pp. 1-8 ◽  
Author(s):  
J. A. van Huyssteen ◽  
J. L. Barnard ◽  
J. Hendriksz
Keyword(s):  
Mathematical Model ◽  
Activated Sludge ◽  
South African ◽  
Nutrient Removal ◽  
Trickling Filter ◽  
The South ◽  
The University ◽  
General Standard

The paper describes the upgrading of an existing trickling filter (TF) plant by adding a new activated sludge (AS) plant in order to remove nutrients from the combined effluent of both plants. In spite of the low COD/TKN ratio, good nitrogen and phosphate removals were obtained in the three-stage Bardenpho (AS) plant. This is at variance with the University of Capetown mathematical model which predicted that nutrient removal in this plant would not be possible due to predicted recycle of nitrates to the anaerobic basin. The results showed that the average effluent phosphate was below 1 mg P/ℓ while the ammonia and nitrates could be controlled to values well below the limits of the South African General Standard. Possible reasons for the anomaly are given.

scholarly journals Combined Effect of Light and Temperature on the Production of Saxitoxins in Cylindrospermopsis raciborskii Strains

Toxins ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 38 ◽  
Author(s):  
Marcella Mesquita ◽  
Miquel Lürling ◽  
Fabiane Dorr ◽  
Ernani Pinto ◽  
Marcelo Marinho
Keyword(s):  
Maximum Growth ◽  
Combined Effect ◽  
Cylindrospermopsis Raciborskii ◽  
Tropical Regions ◽  
Batch Cultures ◽  
Light Intensities ◽  
Cell Quota ◽  
Wide Range ◽  
Lower Light ◽  
Effect Of Light

Cylindrospermopsis raciborskii is a potentially toxic freshwater cyanobacterium that can tolerate a wide range of light and temperature. Due to climatic changes, the interaction between light and temperature is studied in aquatic systems, but no study has addressed the effect of both variables on the saxitoxins production. This study evaluated the combined effect of light and temperature on saxitoxins production and cellular quota in C. raciborskii. Experiments were performed with three C. raciborskii strains in batch cultures under six light intensities (10, 40, 60, 100, 150, and 500 μmol of photons m−2 s−1) and four temperatures (15, 20, 25, and 30 °C). The growth of C. raciborskii strains was limited at lower temperatures and the maximum growth rates were obtained under higher light combined with temperatures equal or above 20 °C, depending on the strain. In general, growth was highest at 30 °C at the lower light intensities and equally high at 25 °C and 30 °C under higher light. Highest saxitoxins concentration and cell-quota occurred at 25 °C under high light intensities, but were much lower at 30 °C. Hence, increased temperatures combined with sufficient light will lead to higher C. raciborskii biomass, but blooms could become less toxic in tropical regions.

Design of nutrient removal activated sludge systems

2003 ◽  
Vol 47 (11) ◽  
pp. 115-122 ◽  
Author(s):  
J. Manga ◽  
J. Ferrer ◽  
A. Seco ◽  
F. Garcia-Usach
Keyword(s):  
Mathematical Model ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Pilot Plant ◽  
Enhanced Biological Phosphorus Removal ◽  
Biological Phosphorus Removal ◽  
User Friendly ◽  
Biological Phosphorus ◽  
Activated Sludge Systems

A mechanistic mathematical model for nutrient and organic matter removal was used to describe the behavior of a nitrification denitrification enhanced biological phosphorus removal (NDEBPR) system. This model was implemented in a user-friendly software DESASS (design and simulation of activated sludge systems). A 484-L pilot plant was operated to verify the model results. The pilot plant was operated for three years over three different sludge ages. The validity of the model was confirmed with data from the pilot plant. Also, the utility of DESASS as a valuable tool for designing NDEBPR systems was confirmed.

scholarly journals Wastewater nutrient removal in a mixed microalgae–bacteria culture: effect of light and temperature on the microalgae–bacteria competition

2017 ◽  
Vol 39 (4) ◽  
pp. 503-515 ◽  
Author(s):  
J. González-Camejo ◽  
R. Barat ◽  
M. Pachés ◽  
M. Murgui ◽  
A. Seco ◽  
...  
Keyword(s):  
Nutrient Removal ◽  
Bacteria Culture ◽  
Effect Of Light

scholarly journals A Mathematical Approach To Demand Estimation In Multi-Segment Oligopoly Markets - With An Application To The Automobile Market

2011 ◽  
Vol 2 (9) ◽  
Author(s):  
Robert P. Culp
Keyword(s):  
Mathematical Model ◽  
Automobile Industry ◽  
Mathematical Approach ◽  
Statistical Regression ◽  
Font Size ◽  
Automobile Market ◽  
Market Prices ◽  
Price Elasticities ◽  
Demand Equations ◽  
The Mathematical Model

<p class="MsoNormal" style="text-align: justify; line-height: normal; margin: 0in 0.5in 0pt;"><span style="font-size: 10pt;"><span style="font-family: Times New Roman;">The purpose of this paper is to develop a purely mathematical approach to determining consumer demand. The model developed allows the researcher to derive demand in an oligopoly market from observed firm output and market prices using only assumptions about each firm, modest restrictions on consumer behavior, and limitations on market structure. The advantage of this revealed demand approach is that it does not require the specification of the consumer&rsquo;s utility function or any firm&rsquo;s production function. In addition, this mathematical approach allows for the estimation of own price and cross price elasticities of demand without statistical regression. </span></span></p><p class="MsoNormal" style="text-align: justify; line-height: normal; margin: 0in 0.5in 0pt;"><span style="font-size: 10pt;"><span style="font-family: Times New Roman;">&nbsp;</span></span></p><p class="MsoNormal" style="text-align: justify; line-height: normal; margin: 0in 0.5in 0pt;"><span style="font-size: 10pt;"><span style="font-family: Times New Roman;">The mathematical model developed is applied to the automobile industry assuming a market characterized by Cournot-Nash behavior and divided into five homogenous vehicle segments. A global optimization program is used to mathematically determine the range of values the coefficients of demand must take in each segment to satisfy market equilibrium. These coefficients can be used to estimate own and cross price elasticities of demand and construct demand equations. </span></span></p><p class="MsoNormal" style="text-align: justify; line-height: normal; margin: 0in 0.5in 0pt;"><span style="font-size: 10pt;"><span style="font-family: Times New Roman;">&nbsp;</span></span></p><p class="MsoNormal" style="text-align: justify; line-height: normal; margin: 0in 0.5in 0pt;"><span style="font-size: 10pt;"><span style="font-family: Times New Roman;">The elasticity estimates generated by the mathematical model of the automobile industry are compared to other estimates of elasticity found by statistical estimation. It is shown that the mathematical model generates results that are consistent with the statistical methods of the automobile market used by other researchers.<span style="mso-spacerun: yes;">&nbsp; </span></span></span></p>

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