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Abstract

We consider in this work a class of finite dimensional time-varying linear disturbed systems. The main objective of this work is to studied the optimal control which ensures the remediability of a disturbance of time-varying disturbed systems. The remediability concept consist to find a convenient control which bringing back the corresponding observation of disturbed system to the normal one at the final time. We give firstly some characterisations of compensation and in second party we find a control which annul the output of the system and we show also that the Hilbert Uniqueness Method can be used to solve the optimal control which ensure the remediability.Ageneral approachwas given to minimize the linear quadratic problem. Examples and numerical simulations are given.
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Authors and Affiliations

El Mostafa Magri
1
Chadi Amissi
1
Larbi Afifi
1
Mustapha Lhous
1

  1. Fundamental and Applied Mathematics Laboratory, Department of Mathematics and Computer Science, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, B.P.5366-Maârif, Casablanca, Morocco
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Abstract

Chromium low alloyed steel substrate was subjected to aluminizing by hot dipping in pure aluminium and Al-Si eutectic alloy at 750°C and 650°C respectively, for dipping time up to 45 minutes. The coated samples were subjected for investigation using an optical microscope, scanning electron microscopy (SEM), Energy-dispersive X-ray analyzer (EDX) and X-ray diffraction (XRD) technique. Cyclic thermal oxidation test was carried out at 500°C for 72 hours to study the oxidation behaviour of hot-dipped aluminized steel. Electrochemical corrosion behavior was conducted in 3wt. %NaCl aqueous solution at room temperature. The cyclic thermal oxidation resistance was highly improved for both coating systems because of the formation of a thin protective oxide film in the outermost coating layer. The gain in weight was decreased by 24 times. The corrosion rate was decreased from 0.11 mmpy for uncoated specimen to be 2.9 x10-3 mmpy for Aluminum coated steel and 5.7x 10-3 mmpy for Al-Si eutectic coated specimens. The presence of silicon in hot dipping molten bath inhabit the growth of coating intermetallic layers, decrease the total coating thickness and change the interface boundaries from tongue like shape to be more regular with flatter interface. Two distinct coating layers were observed after hot dipping aluminizing in Al bath, while three distinct layers were observed after hot dipping in Al-Si molten bath.
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Bibliography

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Authors and Affiliations

G.M. Attia
1
W.M.A. Afify
1
M.I. Ammar
1

  1. Metallurgical and Materials Engineering Department, Faculty of Petroleum and Mining Engineering Suez University, Egypt
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Abstract

Helicobacter species have been reported in animals, some of which are of zoonotic importance. This study aimed to detect Helicobacter species among human and animal samples using conventional PCR assays and to identify their zoonotic potentials. Helicobacter species was identified in human and animal samples by genus-specific PCR assays and phylogenetic analysis of partial sequencing of the 16S ribosomal RNA gene. The results revealed that Helicobacter species DNA was detected in 13 of 29 (44.83%) of the human samples. H. pylori was identified in 2 (15.38%), and H. bovis was detected in 4 (30.77%), whereas 7 (53.85%) were unidentified. H. bovis and H. heilmannii were prevalent among the animal samples. Phylogenetic analysis revealed bootstrapping of sequences with H. cinaedi in camel, H. rappini in sheep and humans, and Wollinella succinogenes in humans. In conclusion, the occurrence of non-H. pylori infections among human and animal samples suggested zoonotic potentials.
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Authors and Affiliations

A.I. Youssef
1
A. Afifi
2
S. Abbadi
3
A. Hamed
4
M. Enany
2

  1. Animal Hygiene and Zoonoses, Faculty of Veterinary Medicine, Suez Canal University, 41522, 4.5 Km Ring Road, Ismailia, Egypt
  2. Microbiology and Immunology Department, Faculty of Veterinary Medicine, Suez Canal University, Egypt
  3. Microbiology and Immunology Department, Faculty of Medicine, Suez University, 43512, Alsalam City, Suez, Egypt
  4. Biotechnology Department, Animal Health Research Institute, P.O. Box 264, Dokki, Giza 12618, Egypt

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