scholarly journals Application of a dynamic model for regulating the hydrothermal regime in early potato cultivation in the Volgograd region

2021 ◽  
Vol 843 (1) ◽  
pp. 012053
Author(s):  
A A Buber ◽  
S A Menshikova ◽  
E A Ivantsova

Abstract The article presents the results of research on the dynamics of development and water consumption of early potatoes, obtained from field observations in a multi-factor experiment, which formed the basis of the initial database of water adaptive regulation, temperature and food regimes based on simulation. The dynamic simulation model “POTATO” developed on this basis is aimed at displaying the processes of phenological development of potatoes and predicting crop yields during irrigation and fertigation. The model provides a forecast of the timing of the early potato development phenological phases, its yield depending on specific soil and weather conditions, as well as irrigation modes (sprinkling, drip and combined ones) and the level of mineral nutrition. The forecast of the dynamics of the culture phenological development allows to adjust the schedule of reclamation measures to regulate water and temperature regimes, taking into account current and forecast meteorological information. The simulation model allows to perform operational management of the hydrothermal and food regime of the agrocoenosis in order to obtain the planned yields. The developed method of regulating the hydrothermal regime based on the “POTATO” simulation model makes it possible to implement operational irrigation management and choose the optimal and cost-effective irrigation strategy.

1997 ◽  
Vol 45 (1) ◽  
pp. 97-107
Author(s):  
H.F. De Zwart ◽  
G.P.A. Bot

This paper studies the prospects for the use of reject heat from on-site combined heat and power generation in horticulture. In particular, the consequences of CO2-dosing with exhaust gases is studied. All computations are made with a recently developed dynamic simulation model describing the energy consumption of a greenhouse and the performance of its heating system as a function of outside weather conditions and horticultural requests of growers in the Netherlands.


2019 ◽  
Vol 11 (6) ◽  
pp. 168781401985284
Author(s):  
Meiliang Wang ◽  
Mingjun Wang ◽  
Xiaobo Li

The use of the traditional fabric simulation model evidently shows that it cannot accurately reflect the material properties of the real fabric. This is against the background that the simulation result is artificial or an imitation, which leads to a low simulation equation. In order to solve such problems from occurring, there is need for a novel model that is designed to enhance the essential properties required for a flexible fabric, the simulation effect of the fabric, and the efficiency of simulation equation solving. Therefore, the improvement study results will offer a meaningful and practical understanding within the field of garment automation design, three-dimensional animation, virtual fitting to mention but a few.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2217
Author(s):  
Daniela Șova ◽  
Mariana Domnica Stanciu ◽  
Sergiu Valeriu Georgescu

Investigating the large number of various materials now available, some materials scientists promoted a method of combining existing materials with geometric features. By studying natural materials, the performance of simple constituent materials is improved by manipulating their internal geometry; as such, any base material can be used by performing millimeter-scale air channels. The porous structure obtained utilizes the low thermal conductivity of the gas in the pores. At the same time, heat radiation and gas convection is hindered by the solid structure. The solution that was proposed in this research for obtaining a material with porous structure consisted in perforating extruded polystyrene (XPS) panels, as base material. Perforation was performed horizontally and at an angle of 45 degrees related to the face panel. The method is simple and cost-effective. Perforated and simple XPS panels were subjected to three different temperature regimes in order to measure the thermal conductivity. There was an increase in thermal conductivity with the increase in average temperature in all studied cases. The presence of air channels reduced the thermal conductivity of the perforated panels. The reduction was more significant at the panels with inclined channels. The differences between the thermal conductivity of simple XPS and perforated XPS panels are small, but the latter can be improved by increasing the number of channels and the air channels’ diameter. Additionally, the higher the thermal conductivity of the base material, the more significant is the presence of the channels, reducing the effective thermal conductivity. A base material with low emissivity may also reduce the thermal conductivity.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bentahar Attaouia ◽  
Kandouci Malika ◽  
Ghouali Samir

AbstractThis work is focused to carry out the investigation of wavelength division multiplexing (WDM) approach on free space optical (FSO) transmission systems using Erbium Ytterbium Doped Waveguide Amplifier (EYDWA) integrated as post-or pre-amplifier for extending the reach to 30 Km for the cost-effective implementation of FSO system considering weather conditions. Furthermore, the performance of proposed FSO-wavelength division multiplexing (WDM) system is also evaluated on the effect of varying the FSO range and results are reported in terms of Q factor, BER, and eye diagrams. It has been found that, under clear rain the post-amplification was performed and was able to reach transmission distance over 27 Km, whereas, the FSO distance has been limited at 19.5 Km by using pre-amplification.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jindrich Spicka ◽  
Jiri Hnilica

The paper deals with weather derivatives as the potentially effective risk management tool for agricultural enterprises seeking to mitigate their income exposure to variations in weather conditions. Design and valuation of the weather derivatives is an interdisciplinary approach covering agrometeorology, statistics, mathematical modeling, and financial and risk management. This paper first offers an overview of data sources and then methods of design and valuation of weather derivatives at the regional level. The accompanied case study focuses on cultivation of cereals (wheat and barley) in the Czech Republic. However, its generalizability is straightforward. The analysis of key growing phases of cereals is based on regression analysis using weather indices as the independent variables and crop yields as dependent variables. With the bootstrap tool, the burn analysis is considered as useful tool for estimating uncertainty about the payoff, option price, and statistics of probability distribution of revenues. The results show that the spatial and production basis risks reduce the efficiency of the weather derivatives. Finally, the potential for expansion of weather derivatives remains in the low income countries of Africa and Asia with systemic weather risk.


Sign in / Sign up

Export Citation Format

Share Document