Wyniki wyszukiwania - Biblioteka Nauki

1

Hybrid fuzzy sliding mode control of a doubly-fed induction generator speed in wind turbines

100%

Kerboua A. , Abid M.

Journal of Power Technologies

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2015

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tom Vol. 95, nr 2

126--133

EN

The aim of this paper is hybrid fuzzy sliding mode control of a Doubly Fed Induction Generator (DFIG) in the form of a wind turbine. This type of control is introduced to avoid the major disadvantage of variable structure systems, namely the chattering phenomenon. Variable structure ensures the high dynamic of convergence and robustness towards parametric variations and disturbances. Fuzzy control is introduced here in order to remove residual vibrations in high frequencies. That approach is used to control the mechanical speed and the reactive power exchanged between the stator circuit and the grid. Those variables are decoupled through vector control. The feasibility of this work is proven by mathematical and simulation models based on MATLAB.

2

Integrated design of observer based fault detection for a class of uncertain nonlinear systems

80%

Chen W. , Khan A. Q. , Abid M. , Ding S. X.

International Journal of Applied Mathematics and Computer Science

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2011

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tom Vol. 21, no 3

423-430

EN

Integrated design of observer based Fault Detection (FD) for a class of uncertain nonlinear systems with Lipschitz nonlinearities is studied. In the context of norm based residual evaluation, the residual generator and evaluator are designed together in an integrated form, and, based on it, a trade-off FD system is finally achieved in the sense that, for a given Fault Detection Rate (FDR), the False Alarm Rate (FAR) is minimized. A numerical example is given to illustrate the effectiveness of the proposed design method.

3

Assessing the effect of oral diseases on oral health related quality of life of institutionalized elderly using Oral Health Impact Profile (OHIP-14) questionnaire: a pilot study

70%

Saxena A. , Nagarajappa R. , Naik D. , Abid M. , Ramesh G.

Roczniki Państwowego Zakładu Higieny

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2020

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tom 71

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nr 3

4

Nonlinear integral backstepping control of wind energy conversion system based on a Double-Fed Induction Generator

70%

Doumi M. , Aissaoui A. G. , Tahour A. , Abid M. , Tahir K.

Przegląd Elektrotechniczny

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2016

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tom R. 92, nr 3

130--135

EN

In this paper, a decoupling control strategy has been applied to control the active and reactive powers generated by a Double Feed Induction Generator (DFIG). We propose a robust nonlinear control based on Backstepping with integral actions in order to control the power of the wind turbine transmitted to the grid and to make the wind turbine adaptable to different constraints. The proposed control laws are derived from the Lyapunov approach which is well suited for this nonlinear system. Furthermore, the proposed integral backstepping control is compared with the classical backstepping controller. The results obtained by simulation prove the effectiveness of the control strategies in terms of decoupling, robustness and dynamic performance for different operating conditions.

PL

W artykule opisano strategię sterowania sprzęgania do kontroli mocy czynnej i biernej wytwarzanej przez generator DFIG. Wykorzystano metodę Lapunowa do kontroli turbiny wiatrowej dołączonej do sieci.

5

In situ impact of the antagonistic fungal strain, Trichoderma gamsii T30 on the plant pathogenic fungus, Rhizoctonia solani in soil

61%

Anees M. , Abid M. , Chohan S. , Jamil M. , Ahmed N. , Zhang L. , Rha E. S.

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tom 68

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nr 2

EN

Rhizoctonia solani is a soil-borne fungus causing a wide range of plants diseases. Trichoderma gamsii strain T30 has previously been reported as antagonistic against R. solani. Although there are a few studies about the influence of Trichoderma strains on the R. solani densityin a pathosystem in the presence of plant hosts, this report for the first time comprehensively describes in situ effects of a T. gamsii strain on the population density of R. solani in the soil microcosmic conditions. The population dynamics of R. solani were followed in the auto-claved and non-autoclaved soils in artificially prepared microcosms up to day 25 after co-inoculation with T. gamsii in the variable ratios (R1/T1; R1/T0.1; R1/T0.01 of R. solani/T. gamsii). The population density of R. solani was evaluated by qPCR. In the autoclaved soil, target DNA copies of R. solani increased in the control samples from 1 × 10⁵ to 6.5 × 10⁶. At R1/T0.01, the number of target DNA copies were not significantly changed until day 11; however, it decreased by around five times at day 25. At R1/T0.1 and R1/T1, the number of DNA copies was reduced to 2.1 × 10⁶ and 7.6 × 10⁵ at day 11, respectively and the reduction was as much as 17 times at day 25. In the non-autoclaved soil, the number of the fungal cells decreased at day 25 whether inoculated or not with Trichoderma indicating a general suppression by the soil microbiome. In brief, T. gamsii significantly inhibited the growth of R. solani in the soil in situ and there was a general suppressive effect of the natural microbiome.

6

Seasonal variation of aflatoxin B1 content in dairy feed

51%

Ismail A. , Riaz M. , Akhtar S. , Yoo S. H. , Park S. , Abid M. , Aziz M. , Ahmad Z.

Journal of Animal and Feed Sciences

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2017

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tom 26

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nr 1

EN

Aflatoxin B1 (AFB1 ) is a fungal metabolite and highly carcinogenic compound of category 1 according to the International Agency for Research on Cancer. In the liver AFB1 from contaminated feed is bioconverted into aflatoxin M1 and can be easily diffused to the animal milk. Provision of healthy milk for humans, particularly infants and adults, therefore, entails monitoring of AFB1 level in the feed for dairy animals. In the present study, AFB1 level was monitored in three different types of animal feed comprising commercially available animal feed, fresh fodder and leftover bread fed to dairy animals between October 2014 and September 2015. AFB1 was found in all collected feed samples at the amounts: 30.5%, 2.8% and 88.9% in commercial feed, fresh fodder and leftover bread samples, respectively. All these levels were over the EU permissible limits (5 μg · kg−1). Mean maximum levels of AFB1 were observed in all samples collected in the winter season, whereas the mean minimum levels – in the summer months. The results of the present study indicated that the leftover bread samples and commercial feed contain high levels of AFB1 , and so strict measures should be adopted to prevent dairy animal feed and at the same time the animal milk from aflatoxin contamination.