Search results for "Lability"

showing 10 items of 802 documents

Evaluation of Silver Ion Bioavailability from Silver Doped Hydroxyapatite

2014

Thein vitrobehavior of silver doped hydroxyapatite (HAp/Ag) prepared by two wet precipitation routes were studied in water and simulated body fluid (SBF). In order to evaluate the silver ion bioavailability from HAp/Ag, the samples were soaked in SBF or water and kept at 37°C for fixed periods of time up to one year. After fixed periods of time, analyses of SBF and water solutions were performed and silver ion concentration within the solutions determined. According to silver release data from dense and porous HAp/Ag ceramic scaffolds, release rate of silver ions were reduced in water as the ion exchange there was slower compared to SBF solution. X-ray diffraction and scanning electron micr…

Materials scienceIon exchangeScanning electron microscopePrecipitation (chemistry)Mechanical EngineeringSimulated body fluidMineralogyBioavailabilityIonMechanics of Materialsvisual_artvisual_art.visual_art_mediumGeneral Materials ScienceCeramicPorosityNuclear chemistryKey Engineering Materials
researchProduct

Amoxicillin-loaded polyethylcyanoacrylate nanoparticles: influence of PEG coating on the particle size, drug release rate and phagocytic uptake.

2001

Polyethyleneglycol (PEG)-coated polyethylcyanoacrylate (PECA) nanoparticles loaded with amoxicillin were prepared and the influence of the PEG coating on the particle size, zeta potential, drug release rate and phagocytic uptake by murine macrophages was studied. Experimental results show that this colloidal drug delivery system could be useful for intravenous or oral administration. The profile of amoxicillin release from PECA nanoparticles system was studied under various conditions similar to those of some corporeal fluids. In all these experiments, amoxicillin release in the free form was studied by HPLC analysis. Experimental results showed that at pH 7.4 drug release rises when molecu…

Materials sciencePhagocytosisBiophysicsNanoparticleBioengineeringBiocompatible MaterialsIn Vitro TechniquesPolyethylene GlycolsBiomaterialsMiceDrug Delivery SystemsDrug StabilityPhagocytosisOral administrationPEG ratioZeta potentialAnimalsHumansCyanoacrylatesParticle SizeChromatographyMacrophagesAmoxicillinHydrogen-Ion ConcentrationUreaseMicrospheresBioavailabilityBiochemistryMechanics of MaterialsDrug deliveryCeramics and CompositesParticle sizeBiomaterials
researchProduct

Reactive Layer Assembly Sustains an Interlocked Structure in Green Processed and Scalable High-Performance Layered Wood

2021

Wood can be processed into structural materials by partial removal of lignin and subsequent hot compression. The fundamental challenge of this process is achieving a cost-effective, green, and scal...

Materials scienceStructural materialRenewable Energy Sustainability and the EnvironmentGeneral Chemical EngineeringProcess (computing)General ChemistryCompression (physics)chemistry.chemical_compoundchemistryScalabilityEnvironmental ChemistryLigninComposite materialLayer (electronics)Efficient energy useACS Sustainable Chemistry & Engineering
researchProduct

Fully Polynomial Time Approximation Scheme for the Two-Parallel Capacitated Machines Scheduling Problem Under Unavailability Constraint

2010

Abstract Decision Support Systems (DSS) ensure the computer-based support for the conscientious decision-making in solving problems that require a large amount of information processing and complex scenarios. DSS for Transportation (DSST) are intelligent systems that are used at operational and organizational management levels. Operating a DSST in a public transportation web-based monitoring system is presented in this paper.

Mathematical optimizationDecision support systemJob shop schedulingbusiness.industryDistributed computingIntelligent decision support systemInformation processingGeneral MedicinePolynomial-time approximation schemeConstraint (information theory)Public transportUnavailabilitybusinessMathematicsIFAC Proceedings Volumes
researchProduct

A new formulation of the optimal compensation and reconfiguration problem including minimum load nodes unavailability for automated distribution netw…

2004

This paper deals with a new formulation of the optimal operation of electrical distribution networks problem in regular working state. In the new deregulated energy market providing reliable and economical service to customers is a primary task. The multiobjective formulation of the reconfiguration and compensation problem used in this paper considers as a primary object also the minimisation of the load nodes unavailability (UA) expressed in probabilistic terms. Therefore, the objectives to be attained through the optimisation strategy are: minimal power losses operation, minimum UA of the load nodes, load balancing among the HV/MV transformers, and voltage profile regularisation. The appl…

Mathematical optimizationEngineeringfeeder reconfigurationbusiness.industryElectric power distributionApplied MathematicsProbabilistic logicEvolutionary algorithmControl reconfigurationComputer Science Applicationslaw.inventionDistributed power generationSettore ING-IND/33 - Sistemi Elettrici Per L'EnergiaCapacitorComputational Theory and MathematicslawElectronic engineeringEnergy marketElectrical and Electronic EngineeringUnavailabilityTransformerbusinessRemote control
researchProduct

Most Diverse Near-Shortest Paths

2021

Computing the shortest path in a road network is a fundamental problem that has attracted lots of attention. However, in many real-world scenarios, determining solely the shortest path is not enough as users want to have additional, alternative ways of reaching their destination. In this paper, we investigate a novel variant of alternative routing, termed the k-Most Diverse Near-Shortest Paths (kMDNSP). In contrast to previous work, kMDNSP aims at maximizing the diversity of the recommended paths, while bounding their length based on a user-defined constraint. Our theoretical analysis proves the NP-hardness of the problem at hand. To compute an exact solution to kMDNSP, we present an algori…

Mathematical optimizationHeuristic (computer science)Computer sciencemedia_common.quotation_subjectAlternative routing Route planning Path similarity Near-shortest paths Path diversificationConstraint (information theory)Iterated functionBounding overwatchShortest path problemScalabilityQuality (business)ddc:004Routing (electronic design automation)media_commonProceedings of the 29th International Conference on Advances in Geographic Information Systems
researchProduct

Energy-Efficient Resource Allocationin for D2D Enabled Cellular Networks

2020

Energy-efficiency (EE) is critical for D2D enabled cellular networks due to limited battery capacity and severe co-channel interference. In this chapter, we address the EE optimization problem by adopting a stable matching approach. The NP-hard joint resource allocation problem is formulated as a one-to-one matching problem under two-sided preferences, which vary dynamically with channel states and interference levels. A game-theoretic approach is employed to analyze the interactions and correlations among user equipments (UEs), and an iterative power allocation algorithm is developed to establish mutual preferences based on nonlinear fractional programming. We then employ the Gale–Shapley …

Mathematical optimizationMatching (statistics)Fractional programmingOptimization problemComputer scienceScalabilityCellular networkResource allocationCommunication channelEfficient energy use
researchProduct

Fixed domain approaches in shape optimization problems

2012

This work is a review of results in the approximation of optimal design problems, defined in variable/unknown domains, based on associated optimization problems defined in a fixed ?hold-all? domain, including the family of all admissible open sets. The literature in this respect is very rich and we concentrate on three main approaches: penalization?regularization, finite element discretization on a fixed grid, controllability and control properties of elliptic systems. Comparison with other fixed domain approaches or, in general, with other methods in shape optimization is performed as well and several numerical examples are included.

Mathematical optimizationOptimization problemDiscretizationApplied MathematicsOpen setGridRegularization (mathematics)Finite element methodComputer Science ApplicationsTheoretical Computer ScienceControllabilitySignal ProcessingShape optimizationMathematical PhysicsMathematicsInverse Problems
researchProduct

Decomposition of Dynamic Single-Product and Multi-product Lotsizing Problems and Scalability of EDAs

2008

In existing theoretical and experimental work, Estimation of Distribution Algorithms (EDAs) are primarily applied to decomposable test problems. State-of-the-art EDAs like the Hierarchical Bayesian Optimization Algorithm (hBOA), the Learning Factorized Distribution Algorithm (LFDA) or Estimation of Bayesian Networks Algorithm (EBNA) solve these problems in polynomial time. Regarding this success, it is tempting to apply EDAs to real-world problems. But up to now, it has rarely been analyzed which real-world problems are decomposable. The main contribution of this chapter is twofold: (1) It shows that uncapacitated single-product and multi-product lotsizing problems are decomposable. (2) A s…

Mathematical optimizationPolynomialDistribution (mathematics)Estimation of distribution algorithmComputer scienceBounded functionScalabilityEDASBayesian networkTime complexity
researchProduct

Average flow constraints and stabilizability in uncertain production-distribution systems

2009

We consider a multi-inventory system with controlled flows and uncertain demands (disturbances) bounded within assigned compact sets. The system is modelled as a first-order one integrating the discrepancy between controlled flows and demands at different sites/nodes. Thus, the buffer levels at the nodes represent the system state. Given a long-term average demand, we are interested in a control strategy that satisfies just one of two requirements: (i) meeting any possible demand at each time (worst case stability) or (ii) achieving a predefined flow in the average (average flow constraints). Necessary and sufficient conditions for the achievement of both goals have been proposed by the aut…

Mathematical optimizationStochastic stabilityControl and OptimizationComputer scienceSCHEDULING POLICIESUNKNOWN INPUTSInventory control; Robust controlRobust controlUncertain systemsUncertain demandsManagement Science and Operations ResearchControl strategies; Inventory systems; Uncertain demands; Worst caseStability (probability)Distribution systemMULTI-INVENTORY SYSTEMSControl theoryProduction (economics)Inventory control Robust control Stochastic stabilityAverage costInventory systemsMathematicsInventory controlStochastic processControl strategiesApplied MathematicsWorst caseNETWORKSControllabilityFlow (mathematics)Bounded functionProduction controlRobust controlSettore MAT/09 - Ricerca OperativaMANUFACTURING SYSTEMS
researchProduct