scholarly journals Allelopatyczny wpływ skoszonej biomasy nadziemnej Lolium perenne na skład gatunkowy i walory estetyczne trawnika

2019 ◽  
Vol 71 (3) ◽  
pp. 61-72
Author(s):  
HALINA LIPIŃSKA ◽  
MAGDALENA SYKUT ◽  
AGNIESZKA KĘPKOWICZ ◽  
WIESŁAW WAŃKOWICZ ◽  
ALICJA BIESKE-MATEJAK ◽  
...  
Keyword(s):  
Species Composition ◽  
Lolium Perenne ◽  
Control Object ◽  
Field Conditions ◽  
General Aspect ◽  
Study Objective ◽  
Overwinter Survival ◽  
Object A

The study objective was to assess the allelopathic impact of the cut aboveground vegetative shoots of the selected lawn cultivars of L. perenne on the decorative value and species composition of the sward, including the share of dicotyledons. The studies were conducted in field conditions. The following indicators of the allelopathic impact of L. perenne were chosen: the share of the sown cultivars and dicotyledons in the lawn sward, general aspect, sward density and overwinter survival in object A, where the cut biomass was left, and in control object B, from which the biomass was removed immediately after cutting. The biomass of ‘Nira’ and ‘Stadion’ cultivars, cut and left on the lawn surface, exhibited auto-allelopathic properties by reducing their own share in the sward. The share of dicotyledons in the sward was reduced to the largest extent in the treatment where the cut biomass of ‘Nira’ cultivar was left. Only the ‘Stadion’ cultivar had a significantly lower sward density and a poorer general aspect of the sward in objects where the cut biomass was left in comparison with the objects where the cut biomass was removed. All the cultivars under study had better overwinter survival results in the objects where the cut biomass was left on the lawn surface.

scholarly journals Allelopathic properties of selected lawn cultivars of Poa pratensis and their utilization in garden compositions

2020 ◽  
Vol 74 (4) ◽  
pp. 135-146
Author(s):  
HALINA LIPIŃSKA ◽  
TERESA WYŁUPEK ◽  
MAŁGORZATA SOSNOWSKA ◽  
AGNIESZKA KĘPKOWICZ ◽  
WOJCIECH LIPIŃSKI ◽  
...  
Keyword(s):  
Species Composition ◽  
Soil Ph ◽  
Significant Influence ◽  
Aboveground Biomass ◽  
Negative Impact ◽  
Poa Pratensis ◽  
Grass Species ◽  
Study Objective ◽  
Overwinter Survival ◽  
The Impact

The study objective was to assess the impact of the vegetative shoots of the lawn cultivars of Poa pratensis (one of the most valuable lawn grasses), cut and left on the lawn surface, on the species composition and overwinter survival of a lawn. The investigation was conducted in a field experiment. Each cultivar was sown in monoculture, on microplots covering 1 m2 each. In the control objects, the cut biomass was removed immediately after the cutting. The investigation showed that ‘Bila’ had the strongest negative impact on the share of sown lawn grass cultivars (sensitivity to the biomass of the same cultivar remaining after cutting). The smallest share of other, unsown grass species in objects where the cut biomass remained was observed in lawns with ‘Nandu’ and, in the case of dicotyledons – with ‘Bila’. The biomass left on the lawn surface after cutting did not have a significant influence on the overwinter survival of the plants. The negative impact of P. pratensis biomass, both on the sown cultivars and other groups of plants, can indicate its allelopathic properties. Therefore, the grass of this species should not be left on the lawn after cutting. The aboveground biomass cut and left on the lawn surface was shown to have a clearly varied influence on the soil pH: in the case of the ‘Ani’ and ‘Bila’ cultivars, the influence was unequivocally negative. In addition, the biomass of these cultivars did not result in significantly increased levels of assimilable forms of phosphorus, potassium and magnesium in the soil.

Synthesis of a Scalar Automatic Control System of a Valve Engine with Field Control for a Rowing Electric Installation with an Azipod Propulsion and Steering System

2021 ◽  
Vol 64 (6) ◽  
pp. 29-35
Author(s):  
Vitaly Vysotsky ◽  
◽  
Igor Markov ◽  
Yuri Matveev ◽  
◽  
...  
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Automatic Control System ◽  
Electric Drive ◽  
Structural Complexity ◽  
Control Object ◽  
Steering System ◽  
Synchronous Machine ◽  
Object A ◽  
Valve Engine

The article deals with the main trends in the development of marine automatic AC electric drive systems. A variant of the implementation of an electric drive using an electromechanical converter of a synchronous machine with electromagnetic field excitation is presented. A promising electric drive system with a valve engine for the icebreaker's with the Azipod propulsion and steering system is proposed. The aim of the work is to eliminate the structural complexity and expand the functional capabilities of the electric drive by using a scalar automatic control system of the frequency of rotation in the two-zone control of the valve motor of the EPS. The novelty lies in the use of the approach and representation of the control object-a valve motor as an analog of a DC collector motor controlled by an armature and by a field. The analysis of control processes is directly related to the processes of electromechanical energy conversion occurring in a synchronous machine.

Coherence preservation in 3-level atom

2011 ◽  
Vol 11 (5&6) ◽  
pp. 420-433
Author(s):  
Fei Yang ◽  
Shuang Cong
Keyword(s):  
Ground State ◽  
Numerical Experiments ◽  
Control Object ◽  
System Model ◽  
Level System ◽  
Multilevel System ◽  
Control Field ◽  
Object A ◽  
Breakdown Time ◽  
Level Atom

Coherence preservation of a multilevel system subject to Markovian decoherence is studied. A Lambda-type three-level atom is selected as the system model. Coherence preservation between a ground state and the excited state of such a system is defined as the control object. A control field is designed by means of constraining the constant coherence condition. For the singularities of the control field, we qualitatively analyze the breakdown time, i.e. the time of control diverging. We obtain the region in which the state stays to maintain coherence forever in the case that the three-level system is reduced to a two-level one. For other cases, we investigate how different parameters affect the breakdown time qualitatively. Numerical experiments are implemented on a three-level quantum system and the experimental results are analyzed.

scholarly journals THE ANALYSIS OF POSSIBLE FAULTS OF TECHNOLOGICAL PROCESSES IN THE RECOVERY BOILER

2021 ◽  
Vol 56 ◽  
pp. 108-111
Author(s):  
Dmitrii A. Kovalev ◽  
Keyword(s):  
Qualitative Analysis ◽  
Control Object ◽  
Chemical Reactor ◽  
Steam Power ◽  
Object A ◽  
Complex Control ◽  
Technological Processes ◽  
Emergency Situations ◽  
Recovery Boiler ◽  
Power Boiler

The analysis of technological processes for a real control object-a recovery boiler is performed in order to determine faults and possible emergency situations. The recovery boiler is considered as a complex control object (in which a chemical reactor is combined with a steam power boiler), which is advisable to decompose into several interconnected subsystems. The study was carried out in accordance with the HAZOP application manual in the form of a qualitative analysis of faults and possible abnormal situations in the recovery boiler. The study was conducted in accordance with the decomposition of the recovery boiler for each constituent of the interconnected subsystems. As a result of research, for each of the subsystems of the recovery boiler, HAZOP work tables were developed that allow you to identify root frames-linked to specific causes of possible faults.

Design of an Optimal Controller in a Voltage Regulation System When Powering Submersible Electromechanical Equipment

2021 ◽  
Vol 64 (6) ◽  
pp. 65-72
Author(s):  
Elena Shandarova ◽  
◽  
Viktor Bukreev ◽  
Victor Rulevskiy ◽  
◽  
...  
Keyword(s):  
Power Supply ◽  
Control Object ◽  
Voltage Regulation ◽  
Optimal Controller ◽  
Regulation System ◽  
State Variables ◽  
Design Algorithm ◽  
Object A ◽  
Electromechanical Equipment ◽  
Dimensional Object

The paper addresses the issue of designing an optimal controller using the measured state variables of a nonlinear multi-dimensional object with transient disturbances – power supply of submersible electromechanical equipment with AC transmission via a cable power line. We present an approach to the design of an adjustable PI-controller enabling to determine its closed-form parameters with the linearized model of a complex control object. A numerical example for simulation of a power supply highlighting capability of the design algorithm for the optimal controller with the quadratic criteria is provided. The obtained results can be used to tackle problems of adaptive control of remotely powered electromechanical objects without sensors.

Vibration Control With Neural Network Dynamic Compensator

1995 ◽  
Author(s):  
Toshinari Shiotsuka ◽  
Kazuo Yoshida ◽  
Akio Nagamatsu
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Control Object ◽  
Time History ◽  
Network Dynamic ◽  
Control Input ◽  
Object A ◽  
Neural Network Controller ◽  
Dynamic Compensator ◽  
Suspension Model

Abstract An approach is presented on designing the dynamic compensator-type controller, using two kinds of neural networks. One is used for identification of system dynamic characteristics of the control object. A time history of response under sine-sweep input is used as the teaching signal of this neural network. The other is used as the neural network controller. The control input is determined with this neural network in order that a performance index concerning the state variable and the input force takes the minimum value. These two neural networks are combined reciprocally in a cascade type in designing the controller. Validity and usefulness of the presented approach are verified by both an computer simulation and an experiment with an active suspension model.

Filth flies associated with municipal solid waste and impact of delay in cover soil application on adult filth fly emergence in a sanitary landfill in Pulau Pinang, Malaysia

2013 ◽  
Vol 103 (3) ◽  
pp. 296-302 ◽  
Author(s):  
A.T. Nurita ◽  
A. Abu Hassan
Keyword(s):  
Species Composition ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Musca Domestica ◽  
Field Conditions ◽  
Lucilia Cuprina ◽  
Sanitary Landfill ◽  
Cover Soil ◽  
Fortnightly Interval ◽  
Study Species

AbstractTwo types of municipal solid waste (MSW), newly arrived and 2 weeks old, were sampled from a sanitary landfill in Pulau Pinang, Malaysia at a fortnightly interval and kept under field conditions for 2 weeks. A total of 480 kg of each type of MSW was sampled to study species composition and impact of delays in cover soil applications on filth fly emergence. Out of 960 kg of MSW sampled, 9.2 ± 0.5 flies emerged per kilogram. Weekly adult fly emergence rates of newly arrived and 2-week-old waste did not differ significantly and MSW remained suitable for fly breeding for up to 1 month. Eight species of flies emerged from the MSW: namely, Musca domestica, Musca sorbens, Synthesiomyia nudiseta, Hydrotaea chalcogaster, Chrysomya megacephala, Lucilia cuprina, Hemipyrellia ligurriens and Sarcophaga sp. Newly arrived waste was determined to be the main source for M. domestica, C. megacephala and L. cuprina in the landfill owing to significantly higher mean emergence compared with 2-week-old waste. Musca sorbens was found in newly arrived waste but not in 2-week-old waste, suggesting that the species was able to survive transportation to landfill but unable to survive landfill conditions. Hemipyrellia ligurriens, H. chalcogaster and S. nudiseta were not imported into the landfill with MSW and pre-existing flies in and around the landfill itself may be their source. The results show that landfills can be a major source of fly breeding if cover soil or temporary cover is not applied daily or on a regular schedule.

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