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Etude et conception d'une machine de polissage des plaques de poignée de porte
No full text94 p. : ; 30 cmCe mémoire de fin d'études porte sur l'étude et la conception d'une machine de polissage destinée aux plaques de poignée de porte, avec un accent particulier sur la rénovation de l'ancienne machine de polissage .cette conception a été faite grâce à SOLIDWORKS (un logiciel de conception assistée par ordinateur).notre objectif principal est de moderniser et d'optimiser le processus de polissage pour améliorer la qualité, l'efficacité de la production.et encore perfectionner considérablement les performances et la qualité du produit final ( la plaque de poignée de porte
Adsorption Behavior of Methylene Blue Onto Activated Coconut Shells: Kinetic, Thermodynamic, Mechanism and Regeneration of the Adsorbent
No full textAdsorption techniques are widely used to remove some classes of pollutants from waters, especially those which are not easily
biodegradable. The removal of Methylene blue (MB), as a pollutant, from waste waters of textile, paper, printing and other
industries has been addressed by the researchers. The aim of this study is to eliminate MB by Activated Coconut Shells (ACS)
produced at low cost by adsorption in batch mode. The ACS was characterized by the FTIR spectroscopy and point of zero
charge (pHpzc: 5.06). Some examined factors were found to have significant impacts on the MB uptake of ACS like the initial dye
concentration Co (40-120 mg/L), solution pH (2-8), ACS dose (1-12 g/L), agitation speed (50-500 r/min), particles size (1.0-
1.2 mm) and temperature (298-333 K). The best capacity was found at pH 6 with an adsorbent dose 8 g/L, an agitation speed
200 r/min and a contact time of 60 min. Modeling Kinetics and Isotherms shows that the pseudo-second-order kinetic model
with R2 (0.935 -0.998) and Langmuir adsorption isotherm model provide better fitness to the experimental data with the
maximum adsorption capacity of 30.30 mg/g at 25°C. The separation factor R L (0.933-0.541) in the concentration range studied
(10-120 mg/L) shows a favorable adsorption. The isotherms at different temperatures have been used for the determination of
the free energy ΔG ° (198-9.72 kJ/mol); enthalpy ΔH ° (82.082 kJ/mol) and entropy ΔS o (245.689 J/K mol) to predict the nature of
MB adsorption process. The positive values of (ΔG o
) and (ΔHo ) indicate a non-spontaneous and endothermic MB adsorption
with a chemisorption. The adsorbent elaborated from Coconut Shells was found to efficient and suitable for the removal of MB
dye from aqueous solutions, due to its availability, low cost preparation and good uptake capacity
Asymptotics for a parabolic problem of Kirchhoff type with singular critical exponential nonlinearity
No full textThe main objective of this paper is to characterize stable sets based on the asymptotic behavior of solutions as t goes to infinity for the following class of parabolic Kirchhoff equations: ut+∥u∥(θ−1)Ns(−Δ)N/ssu=λ|u|q−2uexpα0|u|NN−s|x|γinΩ,t>0,u=0inRN∖Ω,t>0,u(x,0)=u0(x)inΩ,\begin{eqnarray*} \hspace*{13pc}{\left\lbrace \def\eqcellsep{&}\begin{array}{llc}u_{t}+\Vert u\Vert ^{\frac{(\theta -1)N}{s}}(-\Delta)^{s}_{N/s}u=\frac{\lambda |u|^{q-2}u\exp {\left(\alpha _{0}|u|^{\frac{N}{N-s}}\right)}}{|x|^{\gamma }} &\text{in}\ &\Omega,\;t>0, \\ u =0 &\text{in} & \mathbb {R}^{N}\backslash \Omega,\;t > 0, \\ u(x,0)=u_{0}(x)& \text{in} &\Omega, \end{array} \right.} \end{eqnarray*}where ∥u∥Ns=∫R2N|u(x,t)−u(y,t)|N/s|x−y|2Ndxdy,Ω⊂RN(N≥2) is a bounded domain with a Lipschitz boundary, 0∈Ω, α0,λ>0, θ≥1, γ∈[0,N), q>Nθ/s, and (−Δ)N/ss is the fractional N/s‐Laplacian operator, s∈(0,1)
Impact of gamma irradiation on phytochemical composition, and biological activities of Lepidium sativum seeds extract
No full textThe main objective of this research is to assess how gamma radiation influences the chemical composition and activities such as antioxidant, antimicrobial and anticancer activities of Lepidium sativum (L. sativum) seeds. Methanolic extracts were obtained through a 24 h maceration process from L. sativum seeds exposed to various doses of gamma irradiation. Phytochemical screening involved precipitation and staining reactions, with the antioxidant potential assessed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Antimicrobial activity was evaluated through a diffusion test on agar medium, while the cytotoxic potential on the lung cancer line “A-549 cells” was examined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Qualitative analysis of the extracts identified preserved bioactive constituents after irradiation. Additionally, quantitative analysis indicated a significant rise in the total content of polyphenols and flavonoids under radiation, accompanied by an enhanced reducing power compared to the control. The antimicrobial and cytotoxic capabilities also improved, evident in increased growth inhibition zones for certain microbial strains and reduced viability rates of A549 cells. These results show promise and warrant further investigation into the potential of gamma radiation to enhance additional biological effects of plants
آليات تمويل عمليات الإستيراد في المؤسسة الإقتصادية: دراسة حالة ـــ ش ذ م م ــ للخدمات العامة والتجارة آل دوداح ــ
No full text131p.:ill.;30cm
Malicious clouds coalition management for business processes deployment
No full textCloud computing has raised concerns about security, causing many companies to hesitate in adopting it. Despite these concerns, there are methods available to address the risks associated with implementing a business process (BP) in the cloud. One common approach involves breaking down the BP model into smaller fragments, allowing each cloud provider access to a specific part of the overall model. However, this method fails to protect against collaboration between malicious cloud providers, which, by pooling their knowledge, can exploit the logic of the process. To tackle this issue, our paper proposes an approach that effectively manages coalitions when they arise. To do this, we introduce observer and deceiver fragments, which play a crucial role in redirecting the process execution toward a fake task. This strategic redirection prevents access to important information. The obtained results demonstrate that our proposed solution enhances security, mitigates risks, and does not necessarily lead to higher costs compared to other methods based solely on splitting
Data Caching in Edge Computing: A Survey
No full textAs the Internet of Things (IoT) generates ever-increasing data streams, traditional cloud-centric architectures face crippling challenges in network latency, bandwidth consumption, and resource constraints. This paper explores how data caching in edge computing environments emerges as a potent solution, significantly impacting latency reduction, network efficiency, and overall system performance. We comprehensively review the landscape of edge IoT and data caching, analyze caching benefits and complexities, and delve into architectural integration, caching strategies, and algorithms tailored to address specific IoT challenges. Through case studies in chosen application domains, we quantify the performance improvements enabled by effective caching and pave the way for future research exploring novel caching methodologies and optimization techniques in the dynamic world of edge IoT.NNEF Public InformationNursultan Nazarbaev Qor
Étude de performance et redimensionnement de la batterie d’Aéroréfrigérant «A-106 A/F» de l’unité de Topping condensat de la raffinerie de Skikda (RA2K)
No full text84 p. : ill. ; 30 cmEn Raison de la forte demande nationale en essences, l'Algérie a construit la raffinerie de Topping de condensat RA2K à Skikda, avec une capacité annuelle de traitement de 5 millions de tonnes pour valoriser ce condensat. L’objectif de ce mémoire est d’optimiser et garantir le bon fonctionnement de l'unité U-100 (RA2K) durant la période d’été. Pour cela, nous avons opté pour la vérification de cas design initial à une température ambiante de 37°C, et de proposer une solution efficace pour la diminution fréquente de taux de marche ainsi que les variations des températures de Naphta. Alors, nous envisageons de redimensionner la batterie d'aéroréfrigérant A-106 A/F, et la connecter à une nouvelle batterie afin de maximiser le taux de marche maximal de l'unité
