Kinetic modelling of microalgal growth and fucoxanthin synthesis in photobioreactor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaojuan Zhang ◽  
Junru Zhao ◽  
Jie Zhang ◽  
Shijing Su ◽  
Luqiang Huang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Kinetic Parameters ◽  
Kinetic Modelling ◽  
Inhibitory Effect ◽  
Rate Equations ◽  
Phosphorus Concentration ◽  
Model Output ◽  
Nitrogen And Phosphorus ◽  
Nitrogen Phosphorus

Abstract This paper presented a mathematical model to describe the production of fucoxanthin by alga Thalassiosira weissflogi ND-8 in photobioreactor. Our interest was focused on characterizing the effects of nitrogen and phosphorus on the growth of microalgae and on the synthesis of fucoxanthin. The rate equations of microalgal growth, fucoxanthin synthesis and substrate consumptions were formulated. Kinetic parameters of the model and their sensitivities with respect to model output were estimated. The predicted results were compared with experimental data, which showed that this model closely agrees with actual experiment and is able to reflect the growth and metabolism characteristics of microalgae. Our results also indicated that nitrogen plays a major role in the synthesis of fucoxanthin, and the synthesis of fucoxanthin is partially linearly related to the consumption of nitrogen. Phosphorus is primarily consumed in the growth and metabolism of microalgal cells, while excessive phosphorus concentration has an inhibitory effect on the growth of microalgae.

Method application of optimal multi-parameter analysis to assess the distribution of water masses as an example of CTD data of the Barents Sea in summer 2017

2019 ◽  
pp. 38-51
Author(s):  
Valeriy G. Yakubenko ◽  
Anna L. Chultsova
Keyword(s):  
Barents Sea ◽  
Field Measurements ◽  
Structural Similarity ◽  
Water Masses ◽  
Parameter Analysis ◽  
Water Dynamics ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
The Barents Sea ◽  
Expert Assessments

Identification of water masses in areas with complex water dynamics is a complex task, which is usually solved by the method of expert assessments. In this paper, it is proposed to use a formal procedure based on the application of the method of optimal multiparametric analysis (OMP analysis). The data of field measurements obtained in the 68th cruise of the R/V “Academician Mstislav Keldysh” in the summer of 2017 in the Barents Sea on the distribution of temperature, salinity, oxygen, silicates, nitrogen, and phosphorus concentration are used as a data for research. A comparison of the results with data on the distribution of water masses in literature based on expert assessments (Oziel et al., 2017), allows us to conclude about their close structural similarity. Some differences are related to spatial and temporal shifts of measurements. This indicates the feasibility of using the OMP analysis technique in oceanological studies to obtain quantitative data on the spatial distribution of different water masses.

МАТЕМАТИЧЕСКОЕ МОДЕЛИРОВАНИЕ ДИНАМИКИ МИНЕРАЛЬНОГО ПИТАНИЯ РАСТЕНИЙ В СИСТЕМЕ «УДОБРЕНИЕ-ПОЧВА-РАСТЕНИЕ»

2020 ◽  
Vol 65 (6) ◽  
pp. 1219-1229
Author(s):  
В.А. Четырбоцкий ◽  
◽  
А.Н. Четырбоцкий ◽  
Б.В. Левин ◽  
◽  
...  
Keyword(s):  
Experimental Data ◽  
Temporal Dynamics ◽  
Plant Biomass ◽  
Environmental Parameters ◽  
Parametric Identification ◽  
Agricultural Crop ◽  
Parameter System ◽  
Plant Nitrogen ◽  
Rhizosphere Microorganisms ◽  
Nitrogen Phosphorus

A numerical simulation of the spatial-temporal dynamics of a multi-parameter system is developed. The components of this system are plant biomass, mobile and stationary forms of mineral nutrition elements, rhizosphere microorganisms and environmental parameters (temperature, humidity, acidity). Parametric identification and verification of the adequacy of the model were carried out based on the experimental data on the growth of spring wheat «Krasnoufimskaya-100» on peat lowland soil. The results are represented by temporal distributions of biomass from agricultural crop under study and the findings on the content of main nutrition elements within the plant (nitrogen, phosphorus, potassium). An agronomic assessment and interpretation of the obtained results are given.

The substantiation of the formalized estimation of effectiveness of technological and production systems

2018 ◽  
Vol 15 (1) ◽  
pp. 169-181
Author(s):  
M. I. Sidorov ◽  
М. Е. Stavrovsky ◽  
V. V. Irogov ◽  
E. S. Yurtsev
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Production Systems ◽  
Van Der Pol

Using the example of van der Pol developed a mathematical model of frictional self-oscillations in topochemically kinetics. Marked qualitative correspondence of the results of calculation performed using the experimental data of researchers.

Nitrogen and phosphorus in the Vistula River, Poland -- changes from source to mouth

1994 ◽  
Vol 30 (5) ◽  
pp. 177-186 ◽  
Author(s):  
Karin Sundblad ◽  
Andrzej Tonderski ◽  
Jacek Rulewski
Keyword(s):  
Central Region ◽  
Northern Region ◽  
Point Sources ◽  
Nutrient Loss ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
Concentration Data ◽  
Diffuse Sources ◽  
Vistula River ◽  
South Central

Nitrogen and phosphorus concentration data representing samples collected once a month for nine months at 13 locations along the Vistula River are considered in a preliminary discussion of the sources of the nutrients transported to the Baltic Sea. Concentrations in relation to flow data indicated substantial differences between subbasins. Based on those differences, on the area-specific nutrient loss for a six-month period and on the wastewater discharge in each subbasin, four regions could be recognized in the river basin: i) the southern region with a large impact of point sources, ii) the south central region, where diffuse sources seemed to be of major importance, iii) the north central region with a combined effect of point and diffuse sources, and retention in two reservoirs, iv) the northern region where point sources seemed to be the dominating source, at least for phosphorus. Our results illustrate the importance of differences in phosphorus retention between the basins. Long-term retention along the course of the river, particularly in the two reservoirs, must be estimated to allow proper source apportionment in the Vistula basin. Concentration decreases in the Wloclawek Reservoir varied between 44 and 68% for P, and 11 to 37% for N, in the months with significant retention. In some months, however, concentrations increased, indicating a release of nutrients.

scholarly journals Retrieval and Evaluation of Chlorophyll-a Concentration in Reservoirs with Main Water Supply Function in Beijing, China, Based on Landsat Satellite Images

2021 ◽  
Vol 18 (9) ◽  
pp. 4419
Author(s):  
Yuequn Lai ◽  
Jing Zhang ◽  
Yongyu Song ◽  
Zhaoning Gong
Keyword(s):  
Remote Sensing ◽  
Water Supply ◽  
Chlorophyll A ◽  
Phosphorus Concentration ◽  
Landsat 8 ◽  
Supply Function ◽  
Estimation Model ◽  
Nitrogen And Phosphorus ◽  
Chlorophyll A Concentration ◽  
Guanting Reservoir

Remote sensing retrieval is an important technology for studying water eutrophication. In this study, Guanting Reservoir with the main water supply function of Beijing was selected as the research object. Based on the measured data in 2016, 2017, and 2019, and Landsat-8 remote sensing images, the concentration and distribution of chlorophyll-a in the Guanting Reservoir were inversed. We analyzed the changes in chlorophyll-a concentration of the reservoir in Beijing and the reasons and effects. Although the concentration of chlorophyll-a in the Guanting Reservoir decreased gradually, it may still increase. The amount and stability of water storage, chlorophyll-a concentration of the supply water, and nitrogen and phosphorus concentration change are important factors affecting the chlorophyll-a concentration of the reservoir. We also found a strong correlation between the pixel values of adjacent reservoirs in the same image, so the chlorophyll-a estimation model can be applied to each other.

scholarly journals The SN2 reaction and its relationship with the Walden inversion, the Finkelstein and Menshutkin reactions together with theoretical calculations for the Finkelstein reaction

2021 ◽  
Author(s):  
Ibon Alkorta ◽  
José Elguero
Keyword(s):  
Linear Models ◽  
Theoretical Calculations ◽  
Computational Method ◽  
Basis Set ◽  
Free Energies ◽  
Nitrogen And Phosphorus ◽  
Atom Pairs ◽  
Leaving Groups ◽  
First Time ◽  
Nitrogen Phosphorus

AbstractThis communication gives an overview of the relationships between four reactions that although related were not always perceived as such: SN2, Walden, Finkelstein, and Menshutkin. Binary interactions (SN2 & Walden, SN2 & Menshutkin, SN2 & Finkelstein, Walden & Menshutkin, Walden & Finkelstein, Menshutkin & Finkelstein) were reported. Carbon, silicon, nitrogen, and phosphorus as central atoms and fluorides, chlorides, bromides, and iodides as lateral atoms were considered. Theoretical calculations provide Gibbs free energies that were analyzed with linear models to obtain the halide contributions. The M06-2x DFT computational method and the 6-311++G(d,p) basis set have been used for all atoms except for iodine where the effective core potential def2-TZVP basis set was used. Concerning the central atom pairs, carbon/silicon vs. nitrogen/phosphorus, we reported here for the first time that the effect of valence expansion was known for Si but not for P. Concerning the lateral halogen atoms, some empirical models including the interaction between F and I as entering and leaving groups explain the Gibbs free energies.

scholarly journals Exhaust Noise Reduction by Application of Expanded Collecting System in Pneumatic Tools and Machines

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1592
Author(s):  
Dominik Gryboś ◽  
Jacek S. Leszczyński ◽  
Dorota Czopek ◽  
Jerzy Wiciak
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Noise Reduction ◽  
Sound Pressure ◽  
Acoustic Pressure ◽  
Pressure Level ◽  
Computational Results ◽  
Noise Measurements ◽  
Exhaust Noise ◽  
Collecting System

In this paper, we demonstrate how to reduce the noise level of expanded air from pneumatic tools. Instead of a muffler, we propose the expanded collecting system, where the air expands through the pneumatic tube and expansion collector. We have elaborated a mathematical model which illustrates the dynamics of the air flow, as well as the acoustic pressure at the end of the tube. The computational results were compared with experimental data to check the air dynamics and sound pressure. Moreover, the study presents the methodology of noise measurement generated in a pneumatic screwdriver in a quiet back room and on a window-fitting stand in a production hall. In addition, we have performed noise measurements for the pneumatic screwdriver and the pneumatic screwdriver on an industrial scale. These measurements prove the noise reduction of the pneumatic tools when the expanded collecting system is used. When the expanded collecting system was applied to the screwdriver, the measured Sound Pressure Level (SPL) decreased from 87 to 80 dB(A).

Modal Analysis of the Axial Compressor Blade: Advanced Time-Dependent Electronic Interferometry and Finite Element Method

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mykhaylo Tkach ◽  
Serhii Morhun ◽  
Yuri Zolotoy ◽  
Irina Zhuk
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Finite Element ◽  
High Reliability ◽  
Axial Compressor ◽  
Time Dependent ◽  
Experimental Setup ◽  
Vibration Modes ◽  
Compressor Blades ◽  
Isoparametric Finite Element

AbstractNatural frequencies and vibration modes of axial compressor blades are investigated. A refined mathematical model based on the usage of an eight-nodal curvilinear isoparametric finite element was applied. The verification of the model is carried out by finding the frequencies and vibration modes of a smooth cylindrical shell and comparing them with experimental data. A high-precision experimental setup based on an advanced method of time-dependent electronic interferometry was developed for this aim. Thus, the objective of the study is to verify the adequacy of the refined mathematical model by means of the advanced time-dependent electronic interferometry experimental method. The divergence of the results of frequency measurements between numerical calculations and experimental data does not exceed 5 % that indicates the adequacy and high reliability of the developed mathematical model. The developed mathematical model and experimental setup can be used later in the study of blades with more complex geometric and strength characteristics or in cases when the real boundary conditions or mechanical characteristics of material are uncertain.

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