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Two Routes to Produce Chitosan from Agaricus bisporus

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Journal of Renewable Materials 2020年第1期8卷 101-111页

作者： Abdelghani Hassainia Hamid Satha Boufi Sami LSPN University of 8 Mai 1945BP 401Guelma24000Algeria Faculty of Science-LMSE University of SfaxSfax3000Tunisia

Two methods were used to produce chitosan by deacetylation of chitin which was extracted from Agaricus bisporus *** first one gives chitosan 1 with low yield of 2.5%,degree of acetylation(DA)of 4%,molecular weight(MW)of 2.973×10^(5)(g/mol).The second route produces chitosan 2 with higher yield of 41%,degree of acetylation(DA)of 17.23%,molecular weight(MW)of 2.939×10^(5)(g/mol).Both chitosans were characterized by XRD,FTIR,^(1)H-NMR spectroscopy nuclear magnetic resonance of *** molecular weight(MW)was determined by size exclusion chromatography(SEC).Thermal analysis shows that both chitosans have moisture content lower than 10%.However chitosan 2 has the less ash%which is the quality grade for chitosan medical ***,fungal chitosan 2 could have potential medical and agricultural applications.

关键词： Biobased materials chitosan chitin Agaricus bisporus characterization of biomass

Preparation and Characterization of Fe-Based Metallic Glasses with Pure and Raw Elements

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Chinese Physics Letters 2012年第11期29卷 207-210页

作者： Nassima Seghairi Badis Bendjemil Gabriel Lavorato Alberto Castellero Marcello Baricco Dipartimento di Chimica I.F.M/NIS/CNISM/INSTM Universitàdi TorinoVia Giuria 910125 TrinoItaly university of Larbi Ben M'hidi Oum El BouaghiAlgeria LASEA Faculty of SciencesDepartment of ChimistryUniversity of AnnabaAlgeria university of guelma P.O.Box 1224000 GuelmaAlgeria

Amorphous alloys with a composition(at.%)Fe_(48)Cr_(15)Mo_(14)C_(15)B_(6)Y_(2) were prepared by using either pure elements(alloy B1)or a commercial AISI430 steel as a base material(B2).When prepared from pure elements,alloy(B1)could be cast in plate form with a fixed thickness of 2 mm and variable lengths between 10 and 20 mm by means of copper-mold injection in an air *** the case of alloy B2,prepared by using commercial grade raw materials,rods of 2 mm diameter are ***(B1 and B2)of width 5 mm and thickness about 30μm are prepared from the arc-melted ingots using a single roller melt spinner at a wheel speed of 40 m/*** thermal and structural properties of the samples are measured by a combination of differential scanning calorimetry(DSC),x-ray diffraction and scanning electron *** compositions are checked by energy dispersive spectroscopy analysis.X-ray diffraction and scanning electron microscopy observations confirm that an amorphous structure is obtained in all the samples.A minor fraction of crystalline phases(oxides and carbides)is detected on the as-cast *** of hardness and Young modulus were measured by nanoindentation for both the *** effects of adverse casting conditions(such as air atmosphere,non-conventional injection copper mold casting and the partial replacement of pure elements with commercial grade raw materials)on the glass formation and properties of the alloy are discussed.

关键词： alloy casting roller

Viscoelastic Wave Equation with Logarithmic Nonlinearities in Rn

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Journal of Partial Differential Equations 2017年第1期30卷 47-63页

作者： BOUHALI Keltoum ELLAGGOUNE Fateh Universite les freres Mentouri Faculte des sciences exactes Departement de Mathematiques Constantine 25000 Algeria. university 8 Mai 1945-guelma Department of Mathematics Guelma Algeria.

In any spaces dimension, we use weighted spaces to establish a general de- cay rate of solution of viscoelastic wave equation with logarithmic nonlinearities. Furthermore, we establish, under convenient hypotheses on ... 详细信息

关键词： Lyapunov function viscoelastic density, decay rate weighted spaces.

Influence of Rare-Earth Substitution for Iron in FeCrMoCB Bulk Metallic Glasses

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Chinese Physics Letters 2010年第7期27卷 192-194页

作者： Abderrezak Bouchareb Badis Bendjemil Rafael Piccin Marcello Baricco Dipartimento di Chimica I.F.M/NIS/CNISM/INSTM Universita di Torino Via Giuria 9 10125 Torino Italy Laboratoire d'Etude et la Recherche de l'Etat Condensd (LEREC) University of Badji Mokhtar P.O. Box 12 23000 Annaba Algeria university of guelma P.O. Box 12 24000 Guelma Algeria

The effects of rare earth addition on the glass forming ability of Fe50-xCr15Mo14C15B6Mx （x =0, 2 and M=Y, Gd） bulks and ribbons are studied. The thermal and structural properties of the samples are measured by a combination of differential scanning calorimetry （DSC）, x-ray diffraction and scanning electron microscopy. Chemical compositions are checked by energy dispersive spectroscopy analysis. The copper mold casting technique leads to a fully amorphous structure up to 2mm only for compositions containing Y or Gd. In the case of ribbons, a fully amorphous phase is observed for all the compositions. The roles of Y and Gd are discussed on the basis of melting behavior analyzed by high-temperature DSC. Such elements act as oxygen scavengers, avoiding heterogeneous nucleation.

关键词： Dispersants Measurement Microscopy

Design and analysis of a proportional-integral controller based on a Smith predictor for TCP/AQM network systems

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Frontiers of Information Technology & Electronic Engineering 2022年第2期23卷 291-303页

作者： Ouassim MENACER Abderraouf MESSAI Lazhar KASSA-BAGHDOUCHE Department of Electronics Faculty of Technology SciencesFreres Mentouri University of Constantine 125000 ConstantineAlgeria Department of Electronics and Telecommunications Faculty of Science and Technology8 May 1945 University of Guelma24000 GuelmaAlgeria

Active queue management(AQM)is essential to prevent the degradation of quality of service in TCP/AQM systems with round-trip time(RTT)*** delays are primarily caused by packet-propagation delays,but they can also be caused by the processing time of queuing operations and dynamically changing network *** study focuses on the design and analysis of an AQM digital controller under time-delay *** controller is based on the Smith predictor algorithm and is called the SMITHPI *** study also demonstrates the stability of the controller and its robustness against network parameter variations such as the number of TCP connections,time delays,and user datagram protocol *** performance,robustness,and effectiveness of the proposed SMITHPI controller are evaluated using the NS-2 ***,the performance of the SMITHPI controller is compared with that of a well-known queue-based AQM,called the proportional-integral controller.

关键词： Active queue management Transport control protocol Round-trip time delay Smith predictor

New Double Integrals Weighted Cebysev Type Inequalities

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Journal of Mathematics and System Science 2012年第5期2卷 286-291页

作者： A. Guezane-Lakoud F. Aissaoui Laboratory of Advanced Materials University BadjiMokhtar-Annaba Annaba 23000 Algeria Department of Mathematics Guelma university Guelma 24000 Algeria

In the last years, the theory of integral inequalities are playing a very significant role in all fields of mathematics, many monographs have been devoted to this subject and present a very active and attractive field of research, the applications of integral inequalities have known a great development in many branches of mathematics in statistics, differential equations and numerical integration, The aim of this paper is to establish new extension of the weighted montgomery identity for double integrals then used it to establish new t^eby^evtype inequalities.

关键词： Cebysev type inequalities montgomery identity weighted peanokemel double integrals Cebysevinequalities weightedtCebysev inequalities ostrowski inequality.

A Survey on Smart Agriculture:Development Modes,Technologies,and Security and Privacy Challenges

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IEEE/CAA Journal of Automatica Sinica 2021年第2期8卷 273-302页

作者： Xing Yang Lei Shu Jianing Chen Mohamed Amine Ferrag Jun Wu Edmond Nurellari Kai Huang the College of Engineering Nanjing Agricultural UniversityNanjing 210031China the School of Engineering University of LincolnLincoln LN67TSUK the School of Cyber Security Shanghai Jiao Tong UniversityShanghai 200240China Department of Computer Science Guelma UniversityB.P.40124000Algeria

With the deep combination of both modern information technology and traditional agriculture,the era of agriculture 4.0,which takes the form of smart agriculture,has *** agriculture provides solutions for agricultural intelligence and ***,information security issues cannot be ignored with the development of agriculture brought by modern information *** this paper,three typical development modes of smart agriculture(precision agriculture,facility agriculture,and order agriculture)are ***,7 key technologies and 11 key applications are derived from the above *** on the above technologies and applications,6 security and privacy countermeasures(authentication and access control,privacy-preserving,blockchain-based solutions for data integrity,cryptography and key management,physical countermeasures,and intrusion detection systems)are summarized and ***,the security challenges of smart agriculture are analyzed and organized into two aspects:1)agricultural production,and 2)information *** current research projects have not taken agricultural equipment as potential security ***,we did some additional experiments based on solar insecticidal lamps Internet of Things,and the results indicate that agricultural equipment has an impact on agricultural ***,more technologies(5 G communication,fog computing,Internet of Everything,renewable energy management system,software defined network,virtual reality,augmented reality,and cyber security datasets for smart agriculture)are described as the future research directions of smart agriculture.

关键词： Agricultural artificial intelligence agricultural automation agricultural Internet of Things security smart agriculture

New Class of Kirchhoff Type Equations with Kelvin-Voigt Damping and General Nonlinearity:Local Existence and Blow-up in Solutions

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Journal of Partial Differential Equations 2021年第4期34卷 313-347页

作者： DRIDI Hanni ZENNIR Khaled Laboratory of applied mathematics Badji Mokhtar university.P.O.Box 1223000 AnnabaAlgeria Department of Mathematics College of Sciences and ArtsQassim UniversityAr-RassSaudi Arabia Laboratoire de Mathematiques Appliquees et de Modelisation Universite 8 Mai 1945 Guelma.B.P.401 Guelma 24000 Algerie

In this paper,we consider a class of Kirchhoff equation,in the presence of a Kelvin-Voigt type damping and a source term of general nonlinearity *** the studied equation is given as followsutt-K(Nu(t))[Δ_(p(x))^(u)+Δ_(r(x))^(ut)]=F(x,t,u).Mere,K(Nu(t))is a Kirchhoff function,Δ_(r(x))^(ut)represent a Kelvin-Vbigt strong damp-ing term,and F(x,t,u)is a source *** to an appropriate assumption,we obtain the local existence of the weak solutions by applying the Galerkin's approximation ***,we prove a non-global existence result for certain solutions with negative/positive initial *** precisely,our aim is to find a sufficient conditions for p(x)/q(x)/r(x)/F(x/t/u)and the initial data for which the blow-up occurs.

关键词： Galerkin approximation variable exponents Kirchhoff equation blow-up of solutions Kelvin-Voigt damping general nonlinearity

<i>L</i><sup>∞</sup>-Error Estimate of Schwarz Algorithm for Noncoercive Variational Inequalities

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Applied Mathematics 2014年第3期5卷 572-580页

作者： Samira Saadi Allaoua Mehri Laboratory LAIG Department of Mathematics Guelma University Guelma Algeria Laboratory LANOS Department of Mathematics Badji Mokhtar University Annaba Algeria

The Schwarz method for a class of elliptic variational inequalities with noncoercive operator was studied in this work. The author proved the error estimate in L∞-norm for two domains with overlapping nonmatching gri... 详细信息

关键词： Variational Inequalities Schwarz Method Subsolutions L∞-Error Estimates