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Computer science, Informatique, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Generalites, General, Instruments, appareillage, composants et techniques communs à plusieurs branches de la physique et de l'astronomie, Instruments, apparatus, components and techniques common to several branches of physics and astronomy, Techniques et équipements généraux, General equipment and techniques, Capteurs (chimiques, optiques, électriques, de mouvement, de gaz, etc.); télédétection, Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing, Chimie, Chemistry, Chimie analytique, Analytical chemistry, Sciences appliquees, Applied sciences, Informatique; automatique theorique; systemes, Computer science; control theory; systems, Automatique théorique. Systèmes, Control theory. Systems, Robotique, Robotics, Pollution, Pollution atmosphérique, Atmospheric pollution, Méthodes d'analyse, Analysis methods, Capteur chimique, Chemical sensor, Captador químico, Cinétique, Kinetics, Cinética, Ecoulement gaz, Gas flow, Flujo gas, Ecoulement turbulent, Turbulent flow, Flujo turbulento, Etude expérimentale, Experimental study, Estudio experimental, Interface graphique, Graphical interface, Interfaz grafica, Localisation source, Source localization, Localización fuente, Modélisation, Modeling, Modelización, Panache, Plume, Penacho, Pollution air, Air pollution, Contaminación aire, Propriété dynamique, Dynamic properties, Propiedad dinámica, Robot, Robotique, Robotics, Robótica, Règle inférence, Inference rule, Regla inferencia, Règle production, Production rule, Regla producción, Réseau Pétri, Petri net, Red Petri, Système acquisition donnée, Data acquisition system, Sistema adquisición dato, Traçage, Tracing, Trazado, Chemical plume tracing, Diffusive and turbulent airflow, Knowledge, Petri nets, and Rule-based system

This paper presents a Petri net model for autonomous tracking of chemical plumes developed in both diffusive and turbulent airflow environments. It has been challenging to develop a generalized algorithm to effectively trace both types of chemical plumes due to the significant differences of their kinetic and dynamic properties. Our idea is to utilize a Petri net to model the change relationships of chemical concentrations acquired by two sensors mounted on the both sides of a DaNI robot during a tracing process. Because the relationships imply the effects of flow variation on chemical puffs, a flow sensor is eliminated. To express and maintain the knowledge of chemical concentration changes using the Petri net, we design a mapping algorithm for generating the Petri net from production rules. The Petri net model is implemented on the robot using LabVIEW. The chemical plume tracing experiments achieve 93.8% and 87.5% of source localization rates under both turbulent and diffusive airflow environments, respectively.

Electrical engineering, Electrotechnique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Electrotechnique. Electroenergetique, Electrical engineering. Electrical power engineering, Electroénergétique, Electrical power engineering, Conversion directe et accumulation d'énergie, Direct energy conversion and energy accumulation, Conversion électrochimique: piles et accumulateurs électrochimiques, piles à combustibles, Electrochemical conversion: primary and secondary batteries, fuel cells, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Appareils de production et de conversion d'énergie: énergie thermique, énergie électrique, énergie mécanique, etc, Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc, Piles à combustible, Fuel cells, Metaux. Metallurgie, Metals. Metallurgy, Corrosion, Mécanismes fondamentaux et formes de la corrosion, Corrosion mechanisms, Electrolyte polymère, Polymer electrolytes, Acier inoxydable 316, Stainless steel-316, Acier inoxydable 316L, Stainless steel-316L, Acier inoxydable, Stainless steel, Acero inoxidable, Nichtrostender Stahl, Cinétique, Kinetics, Cinética, Kinetik, Défaut ponctuel, Point defect, Defecto puntual, Punktfehler, Dégradation, Degradation, Degradación, Electrolyte solide polymère, Polymer solid electrolyte, Electrólito sólido polímero, Endommagement, Damaging, Deterioración, Environnement, Environment, Medio ambiente, Umgebung, Formation film, Film formation, Formación película, Modèle, Models, Modelo, Pile combustible membrane échangeuse proton, Proton exchange membrane fuel cells, Pile combustible électrolyte solide, Solid electrolyte fuel cells, Pile combustible, Fuel cell, Pila combustión, Brennstoffzelle, Résistance contact, Contact resistance, Resistencia contacto, Kontaktwiderstand, Vitesse corrosion, Corrosion rate, Velocidad corrosión, Korrosionsgeschwindigkeit, Plaque bipolaire, Bipolar plate, Bipolar plates, Corrosion rates, PEFC, and Point defect model

A potentiostatic polarization method is used to evaluate the corrosion behavior of SS316L in simulated anode and cathode environments of polymer electrolyte fuel cells. A passive barrier oxide film is observed to form and reach steady state within ~10 h of polarization, after which time the total ion release rates are low and nearly constant at ~0.4 μg cm-2 h-1 for all potentials investigated. The equilibrium film thickness, however, is a function of the applied potential. The main ionic species dissolved in the liquid are predominately Fe followed by Ni, that account for >90% of the steady-state corrosion current. The dissolution rate of Cr is low but increases systematically at potentials higher than 0.8 V. The experimental ion release rates can be correlated with a point defect model using a single set of parameters over a broad range of potentials (0.2―1 V) on the cathode side. The interfacial contact resistance measured after 48 h of polarization is observed to increase with increase in applied potential and can be empirically correlated with applied load and oxide film thickness. The oxide film is substantially thicker at 1.5 V possibly because of alteration in film composition to Fe-rich as indicated by XPS data.

Energy, Énergie, Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Calcium, Calcio, Cinétique, Kinetics, Cinética, Dioxyde de carbone, Carbon dioxide, Carbono dióxido, Séquestration CO2, CO2 sequestration, Secuestración CO2, Thermogravimétrie, Thermogravimetry, Termogravimetría, CO2 capture, CaO, Calcium looping, and TGA

Calcium looping CO2 capture systems use CaO as a reversible sorbent of CO2. Therefore, the evolution of the CO2 carrying capacity of CaO-materials at increasing number of carbonation―calcination needs to be determined to assess sorbent performance. Thermogravimetric analyzers (TGA) are commonly used for this purpose, by simulating around a small batch of material the average cyclic conditions expected in the real system. Many variables have been reported to influence the results and we review in this paper the main observations and trends, which can at times be conflicting when diffusional effects are not ruled out from the experiments. Furthermore, in a selected number of tests on a typical limestone using four different TG equipment, we have detected that some design characteristics of the TGA apparatus can strongly affect the determination of the CO2 carrying capacities of the material. In particular, we note that the decay in CO2 carrying capacity is accelerated as the power density of the TGA oven increases. This effect is most pronounced in the first calcination cycle, and it seems to be linked to an additional shrinking of the particles taking place in the TG apparatus with the highest heating rates. The use of larger sample masses and/or larger particle sizes tends to reduce the error in the determination of CO2 carrying capacity curves at the expense of departing from differential conditions that are required to obtain kinetic information on the sample.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Amine polymère, Amine polymer, Amina polímero, Amine tertiaire, Tertiary amine, Amina terciaria, Cinétique, Kinetics, Cinética, Colorant organique, Organic dye, Colorante orgánico, Effet structure, Structure effect, Efecto estructura, Effet température, Temperature effect, Efecto temperatura, Etude expérimentale, Experimental study, Estudio experimental, Gel colloïdal, Colloidal gel, Gel coloidal, Gonflement, Swelling, Inflamiento, Libération, Release, Liberación, Méthacrylate polymère, Methacrylate polymer, Metacrilato polímero, Polymère vecteur, Control release polymer, Polímero vector, Polymérisation radicalaire, Free radical polymerization, Polimerización radicalar, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Préparation, Preparation, Preparación, Rhodamine, Rodamina, Triazole dérivé polymère, Triazole derivative polymer, Triazol derivado polímero, Vecteur médicament, Drug carrier, Vector medicamento, pH, Effet densité réticulation, Interaction pi pi, Polymère sensible stimuli, DMAEMA, anticancer, hydrogels, sustained release, and triazole

The purpose of this study is to develop novel triazole-containing hydrogels (TGs) as drug carrier and to investigate the sustained drug release accomplished by their time-dependent swelling behavior. The synthetic pathway of TGs includes: (1) DCC-coupling on hydroxyethyl methacrylate (HEMA) to prepare HEMA-alkyne (HA), (2) click-coupling to prepare a triazole-ring-containing monomer (TM), and (3) the synthesis of a series of TGs. The aggregation between triazole rings is found to be responsible for drug release controllability. Rhodamine 6G is studied as a model anticancer drug for release experiments. The effects of pH and temperature on the properties of sustained drug release are also studied.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Divers, Miscellaneous, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Article synthèse, Review, Artículo síntesis, Cinétique, Kinetics, Cinética, Densité charge, Charge density, Densidad carga, Diffusion lumière, Light scattering, Difusión luz, Effet pH, pH effect, Efecto pH, Effet température, Temperature effect, Efecto temperatura, Force ionique, Ionic strength, Fuerza iónica, Force surface, Surface forces, Interpolymère, Interpolymer, Interpolímero, Microscopie force atomique, Atomic force microscopy, Microscopía fuerza atómica, Mécanisme formation, Formation mechanism, Mecanismo formacion, Méthode étude, Investigation method, Método estudio, Polyélectrolyte, Polyelectrolyte, Polielectrolito, Protéine, Protein, Proteína, Solution chimique, Chemical solution, Solución química, AFM, DLS, PEC, PEM, Relaxation time, and Rheology

Polyelectrolyte complex formation is a well-studied subject in colloid science. Several types of complex formation have been studied, including PEMs, macroscopic polyelectrolyte complexes, soluble complexes and polyelectrolyte complex micelles. The chemical nature of the complex-forming polyelectrolytes and the environmental conditions (e.g., pH, ionic strength and temperature) influence the final structural properties of these complexes. This chapter deals with the kinetics of polyelectrolyte complex formation and discusses how ionic strength, charge density and pH influence the dynamics of the complexes, which can range from glass-like (solid) precipitates to liquid-like phases. The switching between the glass-like and liquid-like phase as a function of the ionic strength has a strong analogy to the phase behaviour of polymer melts as function of temperature. By performing calorimetry during complex formation it has been found that the enthalpy of complex formation of systems that form glass-like phases has an opposite sign to the enthalpy of systems that form liquid-like phases, i.e., the formation of glass-like phases is exothermic and the formation of liquid-like phases is endothermic. The free energy (ΔfG), enthalpy (ΔfH) and entropy (ΔfS) of polyelectrolyte complex formation and how they vary as a function of the ionic strength will be discussed. Results from dynamic light scattering (DLS) titrations, Atomic Force Microscopy (AFM), surface force measurements and rheology will be used to illustrate how differences in kinetics show up in experiments on colloidal micellar systems. In the section on DLS titrations, three-component systems containing two oppositely charged polyelectrolytes and protein molecules will be discussed. This chapter concludes with a section dedicated to the complex formation of oppositely charged protein molecules.

Environment, Environnement, Pollution, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Pollution, Déchets, Wastes, Déchets divers et constituants particuliers des déchets, Other wastes and particular components of wastes, Azote, Nitrogen, Nitrógeno, Cinétique, Kinetics, Cinética, Dioxyde de carbone, Carbon dioxide, Carbono dióxido, Hydrocarbure, Hydrocarbon, Hidrocarburo, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Polychlorobiphényles, Polychlorobiphenyls, Polichlorobifenilos, Pyrolyse, Pyrolysis, Pirólisis, Thermogravimétrie, Thermogravimetry, and Termogravimetría

Thermogravimetric (TG) analysis and infrared spectroscopy were used to analyze the pyrolysis characteristics of printed circuit board scraps (PCBs), coal powder and their mixtures under nitrogen atmosphere. The experimental results show that there is a large difference between waste PCBs and coal powder in pyrolysis processing. The pyrolysis properties of the mixing samples are the result of interaction of the PCBs and coal powder, which is influenced by the content of mixture. The degree of pyrolysis and pyrolysis properties of the mixture are much better than that of the single component. The TG and the differential thermogravimetric (DTG) curves of the PCBs mixed with coal powder move towards the high-temperature zone with increasing amount of coal powder and subsequently the DTG peak also becomes wider. The Coats-Redfern integral method was used to determine the kinetic parameters of pyrolysis reaction mechanism with the different proportion of mixture. The gas of pyrolysis mainly composes of CO2, CO, H2O and some hydrocarbon. The bromide characteristic absorption peak has been detected obviously in the pyrolysis gas of PCBs. On the contrary, the absorption peak of the bromide is not obvious in pyrolysis gas of the PCBs samples adding 40% coal powder.

Electronics, Electronique, Condensed state physics, Physique de l'état condensé, Sciences exactes et technologie, Exact sciences and technology, Physique, Physics, Domaines interdisciplinaires: science des materiaux; rheologie, Cross-disciplinary physics: materials science; rheology, Science des matériaux, Materials science, Nanomatériaux et nanostructures : fabrication et caractèrisation, Nanoscale materials and structures: fabrication and characterization, Nanotubes, Chimie, Chemistry, Chimie generale et chimie physique, General and physical chemistry, Théorie des réactions, cinétique générale. Catalyse. Nomenclature, documentation chimique, informatique chimique, Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry, Catalyse, Catalysis, Catalyseurs: préparations et propriétés, Catalysts: preparations and properties, Physicochimie des réactions induites par rayonnements, particules et ultrasons, Physical chemistry of induced reactions (with radiations, particles and ultrasonics), Photochimie, Photochemistry, Sciences appliquees, Applied sciences, Electronique, Electronics, Electronique des semiconducteurs. Microélectronique. Optoélectronique. Dispositifs à l'état solide, Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices, Electronique moléculaire, nanoélectronique, Molecular electronics, nanoelectronics, Activité catalytique, Catalyst activity, Actividad catalítica, Aire superficielle, Surface area, Area superficial, Cinétique, Kinetics, Cinética, Colorant basique, Basic dye, Colorante básico, Colorant thiazinique, Thiazine dye, Colorante tiazínico, Courant impulsionnel, Pulse current, Corriente impulsional, Dégradation, Degradation, Degradación, Dépôt électrolytique, Electrodeposition, Depósito electrolítico, Endommagement, Damaging, Deterioración, Evaluation performance, Performance evaluation, Evaluación prestación, Fabrication microélectronique, Microelectronic fabrication, Fabricación microeléctrica, Matériau composite, Composite material, Material compuesto, Nanoparticule, Nanoparticle, Nanopartícula, Nanotechnologie, Nanotechnology, Nanotecnología, Nanotube, Nanotubo, Oxyde de titane, Titanium oxide, Titanio óxido, Photocatalyse, Photocatalysis, Fotocatálisis, Réseau (arrangement), Array, Red, Solution aqueuse, Aqueous solution, Solución acuosa, 8107D, 8245J, 8540H, TiO2, Ag-deposited TiO2 nanotube, Bamboo-type TiO2 nanotubes, Photocatalytic activity, and Pulse-current electrodeposition

Photocatalysis phenomena in TiO2 have been intensively investigated for its potential application in environmental remediation. The present work reports improved photocatalytic degradation of methylene blue dye in aqueous solution by using bamboo-type TiO2 nanotubes deposited with Ag nanoparticles via electrochemical deposition. The photocatalytic processes are performed on Ag-modified TiO2 bamboo-type nanotube arrays, Ag-modified smooth-walled nanotube arrays, and bare smooth-walled nanotube arrays. Both Ag-modified bamboo-type and smooth-walled nanotube arrays show improved photocatalytic degradation efficiencies (64.4% and 52.6%) compared to smooth-walled TiO2 nanotubes of the same length (44.4%), due to the enhanced electron-hole seperation and more surface area provided by bamboo ridges. The photocatalytic activity and kinetic behavior of Ag-modified bamboo-type nanotube arrays are also optmized by tuning pulse deposition time of Ag nanoparticles. Bamboo-type nanotubes deposited with Ag nanoparticles via pulse deposition time of 0.5 s/1.5 s shows the highest methylene blue degradation efficiency of 78.5%, which represents 21.9% and 76.8% enhancement of efficiency compared to those of bare bamboo-type and smooth-walled nanotubes, respectively, indicating that a proper amount of Ag nanoparticles on TiO2 can maximize the photocatalytic processes. In addition, overly long pulse deposition time will not further increase photocatalytic activity due to agglomeration of Ag paticles. For example, when the pulse deposition time is increased to 2 s/6 s, Ag-modified bamboo-type nanotube array exhibits a lower photocatalytic degradation efficiency of 62.9%.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Etudes théoriques. Données et constantes. Mesures, Theoretical studies. Data and constants. Metering, Combustion. Flammes, Combustion. Flame, Combustion des combustibles liquides, Combustion of liquid fuels, Biocarburant, Biofuel, Biocarburante, Chaîne courte, Short chain, Cadena corta, Cinétique, Kinetics, Cinética, Combustion, Combustión, Ester, Flamme laminaire, Laminar flame, Llama laminar, Oxydation, Oxidation, Oxidación, Propagation flamme, Flame propagation, Propagación llama, Acide alcanoïque ester méthyle, Acide alcanoïque ester éthyle, Alkyl esters, Ethyl esters, Laminar flames, and Methyl esters

The oxidation characteristics of several small methyl and ethyl esters with carbon number less than six were investigated in laminar flames. The kinetics of such fuels are subsets of those of larger alkyl esters that are constituents of practical biodiesel fuels. A total of seven fuels, namely methyl formate, methyl acetate, methyl propionate, methyl butanoate, ethyl formate, ethyl acetate, and ethyl propionate were considered. Experiments were conducted at atmospheric pressure, elevated reactant temperatures, and over a wide range of equivalence ratios. Laminar flame speeds were determined in the counterflow configuration in which flow velocities were measured using particle image velocimetry. Several detailed kinetic models were tested against the experimental data, and insight was provided into the high-temperature combustion kinetics of the aforementioned fuels. Based on comparisons between experimental and computed results it became apparent that the chemistry of alkyl-ester combustion chemistry is evolving and much needs to be done in order to derive improved rate constants for a wide range of elementary steps.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Cristallisation, Crystallization, Lactone polymère, Lactone polymer, Lactona polímero, Caprolactone polymère, Polycaprolactone, Caprolactona polímero, Cinétique, Kinetics, Cinética, Cristallisation isotherme, Isothermal crystallization, Cristalización isotérmica, Cristallisation état fondu, Melt crystallization, Cristalización estado fundido, Effet température, Temperature effect, Efecto temperatura, Etude comparative, Comparative study, Estudio comparativo, Etude expérimentale, Experimental study, Estudio experimental, Nucléation, Nucleation, Nucleación, Polymère linéaire, Linear polymer, Polímero lineal, Polymère monodispersé, Monodispersed polymer, Polímero monodispersado, Relation masse moléculaire propriété, Molecular weight property relation, Relación masa molecular propiedad, Température transformation, Transformation temperature, Temperatura transformación, Autonucléation, (SSA), Crystallization, Cyclic poly(ε-caprolactone), Self-nucleation, and Successive Self-nucleation and Annealing

A series of low polydispersity cyclic PCL samples (C-PCLs), as well as their linear analogs (L-PCLs), were synthesized by click chemistry in a number average molecular weight (Mn) range of 2-22 kg/mol. They were investigated by Polarized Light Optical Microscopy (PLOM) and Differential Scanning Calorimetry (DSC). The nucleation and overall crystallization kinetics were studied, as well as their self-nucleation behavior and SSA (Successive Self-nucleation and Annealing) thermal fractionation. Cyclic PCLs were found to nucleate and crystallize faster than linear PCLs due to: (a) faster diffusion of C-PCL chains and (b) larger supercoolings of C-PCLs at any given crystallization temperature, as compared to L-PCLs. A bell shape curve was obtained when the overall crystallization rate was examined as a function of Mn, this effect is probably due to a competition between nucleation and diffusion. It was found for the first time, that since cyclic molecules have lower entanglement densities, they can quickly recover their pseudo-equilibrium compact coil conformations upon melting and therefore exhibit much smaller crystalline memory effects than their linear counterparts of identical chain lengths. SSA revealed that C-PCLs are more sensitive to annealing than L-PCLs because their ring topology and limited lamellar chain folding facilitates crystal thickening.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères d'origine naturelle, Natural polymers, Amidon et polyosides divers, Starch and polysaccharides, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés spéciales (catalyseur, réactif ou support), Special properties (catalyst, reagent or carrier), Sciences biologiques et medicales, Biological and medical sciences, Sciences medicales, Medical sciences, Pharmacologie. Traitements medicamenteux, Pharmacology. Drug treatments, Pharmacologie générale, General pharmacology, Technologie pharmaceutique. Industrie pharmaceutique, Pharmaceutical technology. Pharmaceutical industry, Adhérence, Adhesion, Adherencia, Article synthèse, Review, Artículo síntesis, Cinétique, Kinetics, Cinética, Libération, Release, Liberación, Muqueuse, Mucosa, Mécanisme, Mechanism, Mecanismo, Polymère vecteur, Control release polymer, Polímero vector, Vecteur médicament, Drug carrier, Vector medicamento, Mucoadhérence, Mucoadhésif, Mucoadhesive drug delivery systems, Mucoadhesive natural, synthetic and semi-synthetic polymers, and Pharmaceutical materials science pharmaceutical research and development

The presence of a mucus layer that covers the surface of a variety of organs has been capitalized to develop mucoadhesive dosage forms that remain in the administration site for prolonged times, increasing the local and/or systemic bioavailability of the administered drug. The emergence of micro and nanotechnologies together with the implementation of non-invasive and painless administration routes has revolutionized the pharmaceutical market and the treatment of disease. Aiming to overcome the main drawbacks of the oral route and to maintain patient compliance high, the engineering of innovative drug delivery systems administrable by mucosal routes has come to light and gained the interest of the scientific community due to the possibility to dramatically change pharmacokinetics. In addition, to achieve the goal of mucosal drug administration, the development of biomaterials has been refined to fit specific applications. The present review initially describes the potential of nano-drug delivery systems conceived for mucosal administration by diverse non-parenteral routes (e.g., oral, inhalatory, etc.). Then, the benefit of the incorporation of mucoadhesive polymers into the structure of these innovative pharmaceutical products to prolong their residence time in the administration site and the release of the drug cargo will be discussed with focus in the developments of the last decade. In addition, the regulatory status of the most extensively used mucoadhesive polymers will be emphasized. Finally, a thorough overview of the different pharmaceutical applications of mucoadhesive polymers will be addressed.

Chemical engineering, Génie chimique, Computer science, Informatique, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Industrie gazière, Gas industry, Traitements et conditionnement des gaz. Désulfuration. Liquéfaction, Gas conditioning and treatments. Desulphurization. Liquefaction, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Utilisation rationnelle de l'énergie: récupération et économies d'énergie, Rational use of energy: conservation and recovery of energy, Chaudière récupération, Waste heat boiler, Caldera recuperación, Cinétique, Kinetics, Cinética, Conception ingénierie, Engineering design, Concepción ingeniería, Désulfuration, Desulfurization, Desulfuración, Energie totale, Total energy, Energía total, Four, Furnace, Horno, Modèle cinétique, Kinetic model, Modelo cinético, Modélisation, Modeling, Modelización, Optimisation, Optimization, Optimización, Production combinée, Cogeneration, Producción combinada, Réacteur, Reactor, Récupération chaleur, Heat recovery, Recuperación calor, Récupération énergie, Energy recovery, Recuperación energía, Usine chimique, Chemical plant, Fábrica productos químicos, Vapeur eau, Water vapor, Vapor agua, Acid gas, Claus process, Detailed kinetics, and Total plant optimization

Multi-scale process modeling is very appealing methodology for process optimization since it highlights certain issues that remain unexplored with conventional methodologies and debottlenecks certain potentialities that remain unexploited in chemical plants. In this work, a kinetic model with 2400 reactions and 140 species is implemented in a proper reactor network to characterize the thermal furnace and the waste heat boiler of sulfur recovery units; the network with detailed kinetics is the kernel of a Claus process simulation that includes all the unit operations and the catalytic train. By doing so, reliable estimation of acid gas conversion, elemental sulfur recovery, and steam generation is achieved with the possibility to carry out an integrated process-energy optimization at the total plant scale.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères et rayonnements, Polymers and radiations, Polymérisation, Polymerization, Industrie des polymeres, peintures, bois, Polymer industry, paints, wood, Technologie des polymères, Technology of polymers, Formes d'application et semiproduits, Forms of application and semi-finished materials, Matériaux composites, Composites, Article synthèse, Review, Artículo síntesis, Cinétique, Kinetics, Cinética, Cristal liquide dispersé polymère, Polymer dispersed liquid crystals, Efficacité diffraction, Diffraction efficiency, Eficacia difracción, Formation motif, Patterning, Formacíon motivo, Holographie, Holography, Holografía, Morphologie, Morphology, Morfología, Nanocomposite, Nanocompuesto, Polymère cristal liquide, Liquid crystal polymers, Polymérisation photochimique, Photopolymerization, Polimerización fotoquímica, Séparation phase, Phase separation, Separación fase, Polymérisation holographique, liquid-crystalline polymers (LCP), phase separation, photopolymerization, and self-assembly

Holographic polymerization (HP) is a simple, fast, and attractive technique to fabricate one-, two- and three-dimensional complex and functional nanostructures. Not only does the coupling of photopolymerization and light-directed phase separation HP process render rich polymer physics to the latter, it also leads to profound morphology-sensitive properties of HP structures, ranging from nano- to mesoscales. The past two decades witnessed tremendous progress in the field and in this review, we will probe the fundamental characteristics and parameters of HP, exemplify the versatility of this nanofabrication technique by presenting a diverse selection of HP patterned soft materials, and discuss some unique applications of such HP structures.

Energy, Énergie, Geology, Géologie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Combustibles, Fuels, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Calcaire, Limestone, Calcáreo, Calcium, Calcio, Carbonatation, Carbonation, Carbonatación, Cinétique, Kinetics, Cinética, Dioxyde de carbone, Carbon dioxide, Carbono dióxido, Frittage, Sintering, Sinterización, Séquestration CO2, CO2 sequestration, Secuestración CO2, CO2 capture, and Calcium Looping

CO2 capture by means of CaO cycling represents a cost effective, immediate solution to rising CO2 emissions. The mechanism of loss of utilization efficiency and associated change in carbonation kinetics of CaO particles was examined by conducting calcination/carbonation cycling of 150-250 μm Strasburg limestone precursor, by swinging the pressure from atmospheric (for calcination) to 5, 10 and 20 barg (for carbonation) at constant temperatures of 975-1025 °C and a flow of pure CO2. Increased carbonation pressure led to an increase in utilization over 100 cycles from 0.128 ± 0.005 to 0.271 ± 0.035 for 5 and 20 barg respectively. Samples were examined by scanning electron microscopy and BET. The carbonation kinetics were determined by plotting the rates of reaction for both the kinetically controlled and diffusion controlled carbonation stages. Sintering, grain boundary formation and elimination, and changes in particle surface area are found to all play important roles in causing the initial rapid loss in surface reaction-controlled rate, followed by partial recovery over multiple cycles. The loss of grain boundaries due to sintering caused an increase in the reaction-controlled rate and residual calcium utilization due to a shift in the dynamics of carbonation/calcination nucleation and molecular volume contraction. The rate of the reaction-controlled regime was found to be a function of carbonation pressure. The diffusion-controlled rate is independent of pressure and temperature.

Metallurgy, welding, Métallurgie, soudage, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Metaux. Metallurgie, Metals. Metallurgy, Transformation de matériaux métalliques, Production techniques, Traitements de surface, Surface treatment, Alliage base titane, Titanium base alloys, Aluminium alliage, Aluminium alloy, Aluminio aleación, Aluminiumlegierung, Cinétique, Kinetics, Cinética, Kinetik, Courbe TTT, TTT curve, Curva TTT, ZTU Schaubild, Etat solide, Solid state, Estado sólido, Fester Zustand, Formage, Forming, Conformado, Umformen, Plasma, Projection plasma, Plasma spraying, Proyección plasma, Plasmaspritzen, Projection à chaud, Hot spraying, Proyección en caliente, Spritzen, Traitement surface, Surface treatment, Tratamiento superficie, Oberflaechenbehandlung, Traitement thermique, Heat treatment, Tratamiento térmico, Waermebehandlung, Vanadium alliage, Vanadium alloy, Vanadio aleación, Vanadiumlegierung, TTT diagram, Ti-6Al-4V, characterization, heat treatment, net-shape forming, and vacuum plasma spray

Because of the nature of the plasma spraying process, the physical and mechanical properties of vacuum-plasma-sprayed structures of Ti-6AI-4V alloy are completely different from those of conventionally manufactured alloys such as bulk materials from casting and forging. To obtain desired mechanical and physical properties, vacancy and internal defects must be reduced, splat boundaries must be eliminated, and optimal phase compositions should be obtained through postdeposition heat treatments. To determine appropriate heat treatment processes, one needs to study the kinetic behavior of the as-sprayed microstructure at elevated temperatures. In the current study, the kinetics of the solid transformations found in Ti-6AI-4V alloys produced during the vacuum plasma spraying process was studied based on the Johnson-Mehl-Avrami theory. For the kinetic behavior of this alloy, the nonconstant temperature dependence of the transformation rate constant exhibits an irregularity at 900 °C, marking a change in the transformation mechanism. For the lower-temperature (<900 °C) curves, the constant gradient indicates a lack of change in the transformation mechanism, including homogeneous nucleation, with growth of a phase. For higher temperatures (>900 °C), a gradient change indicates a change in the transformation mechanism. The first mechanism was the formation of α-phase grain boundary, and the second mechanism was α-plate nucleation and growth from grain boundaries. The value of the transformation rate constant in the kinetics study of as-sprayed Ti-6AI-4V alloy was much higher than for material produced by the casting method. Using the results obtained from the kinetics of the β → α + β phase transformation at different constant temperatures, a time-temperature-transformation (TTT) diagram for as-sprayed Ti-6AI-4V alloy was developed.

Polymers, paint and wood industries, Polymères, industries des peintures et bois, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Physicochimie des polymeres, Physicochemistry of polymers, Polymères organiques, Organic polymers, Propriétés et caractérisation, Properties and characterization, Propriétés des solutions et des gels, Solution and gel properties, Cinétique, Kinetics, Cinética, Congélation, Freezing, Congelación, Diffusion RX centrale, Small angle X ray scattering, Difusión rayo X central, Effet solvant, Solvent effect, Efecto solvente, Enchevêtrement moléculaire, Molecular entanglement, Encabestradura molecular, Etat actuel, State of the art, Estado actual, Gel physique, Physical gel, Gel físico, Gélification, Gelation, Gelificación, Hydrogel, Hidrogel, Liaison hydrogène, Hydrogen bond, Enlace hidrógeno, Macroporosité, Macroporosity, Macroporosidad, Solution aqueuse, Aqueous solution, Solución acuosa, Vinylique alcool polymère, Polyvinylalcohol, Vinílico alcohol polímero, Cristallisation confinée, Confined polymer crystallization, Cryotropic gelation, Ostwald stage-rule, Poly(vinyl alcohol) hydrogels, and Time-resolving small angle neutron scattering

Aqueous poly(vinyl alcohol) (PVA) solutions subjected to cryogenic treatment form strong physical gels. The cryogenic treatment basically consists of freezing an initially homogeneous polymer solution at low temperatures, storing in the frozen state for a definite time, and defrosting. These gels are of great interest for biotechnology, medicine, the food industry, and many other applications. The outstanding properties of these systems depend on a complex macroporous architecture, whereby PVA chains and water molecules are organized over different hierarchical length scales. The structure and the principal processes subtending the formation of these systems are discussed in the framework of our current understanding of polymer gels. These processes involve formation of ice crystals, PVA crystallization, liquid-liquid phase separation, hydrogen bonding, and entanglements. Small angle neutron scattering is used to follow the cryotropic gelation of PVA/water solutions and detailed information is extracted concerning the gelation mechanism and kinetic parameters related to the formation of these complex systems.

Sustainable development, Développement durable, Environment, Environnement, Management economics, Gestion, économie, management, Pollution, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Pollution, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie appliquée, Applied ecology, Conservation, protection, gestion de l'environnement, de la flore et de la faune, Conservation, protection and management of environment and wildlife, Environnement et développement durable, Environment and sustainable development, Chromate, Chromates, Cromato, Chrome, Chromium, Cromo, Cinétique, Kinetics, Cinética, Développement durable, Sustainable development, Desarrollo sostenible, Lessivage, Leaching, Lavado, Protection environnement, Environmental protection, Protección medio ambiente, Prévention pollution, Pollution prevention, Prevención polución, Sulfate, Sulfates, Sulfato, Chromium sulfate, Cr―Fe alloy, and Leaching kinetics

In the traditional leaching process for producing chromate from chromite ore, large quantities of chromium-containing residues and dusts are discharged, creating serious environmental pollution. In order to solve this serious environmental problem and realize a clean production process for chromate, a new cleaning process using a Cr―Fe alloy as a raw material has been developed, in which the pollution problem of chromium-containing residues caused by the leaching process is resolved. The effects of leaching temperature, reaction time, particle size, stirring rate, and liquid-to-solid ratio in the leaching process have been investigated in this study. The experiment results show that the leaching ratio of the Cr and Fe in the alloy can be greater than 97% at a leaching temperature of 90 °C, a liquid-to-solid ratio of 3:1, an alloy powder particle size of 200 mesh, a stirring rate of 300 rpm and a leaching time of 6 h. Kinetic analysis was carried out, and the calculated activation energy for chromium leaching was 43.94 kJ/mol, indicating control of this process by a chemical reaction on the particle surface. In the proposed process for producing chromate from a Cr―Fe alloy, chromium is present in the form of Cr3+, so the pollution problem of hexavalent chromium residues can be resolved and clean production can be realized.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Etudes théoriques. Données et constantes. Mesures, Theoretical studies. Data and constants. Metering, Combustion. Flammes, Combustion. Flame, Divers, Miscellaneous, Cinétique, Kinetics, Cinética, Dimension particule, Particle size, Dimensión partícula, Distribution dimension particule, Particle size distribution, Distribución dimensión partícula, Décane, Decane, Decano, Etude expérimentale, Experimental study, Estudio experimental, Flamme diffusion, Diffusion flame, Llama difusión, Flamme laminaire, Laminar flame, Llama laminar, Formation, Formación, Hydrocarbure, Hydrocarbon, Hidrocarburo, Kérosène, Kerosene, Queroseno, Modèle, Models, Modelo, Modélisation, Modeling, Modelización, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Mélange carburant, Fuel mixture, Mezcla carburante, Suie, Soot, Hollín, Jet A-1 surrogate, Kerosene chemical kinetic mechanism, Laminar coflow diffusion flame, Soot aggregate size distribution, Soot model, and Synthetic kerosene surrogate

A fully-coupled soot formation model is developed to predict the concentration, size, and aggregate structure of soot particles in the atmospheric pressure laminar coflow diffusion flames of a three-component surrogate for Jet A-1, a three-component surrogate for a Fischer-Tropsch Synthetic Paraffinic Kerosene (SPK), and n-decane. To model the chemical structure of the flames and soot precursor formation, a detailed chemical kinetic mechanism for fuel oxidation, with 2185 species and 8217 reactions, is reduced and combined with a Polycyclic Aromatic Hydrocarbon (PAH) formation and growth scheme. The mechanism is coupled to a highly detailed sectional particle dynamics model that predicts the volume fraction, structure, and size of soot particles by considering PAH-based nucleation, surface growth, PAH surface condensation, aggregation, surface oxidation, fragmentation, thermophoresis, and radiation. The simulation results are validated by comparing against experimental data measured for the flames of pre-vaporized fuels. The objectives of the present effort are to more accurately simulate the physical soot formation processes and to improve the predictions of our previously published jet fuel soot formation models, particularly for the size and aggregate structure of soot particles. To this end, the following improvements are considered: (1) addition of particle coalescence submodels to account for the loss of surface area, reduction of the number of primary particles, and increase of primary particle diameters upon collision, (2) consideration of a larger PAH molecule (benzopyrene instead of pyrene) for nucleation and surface growth to enhance the agreement between the soot model and the measured chemical composition of soot particles, and (3) implementation of a dimerization efficiency in the soot inception submodel to account for the collisions between PAH molecules that do not lead to dimerization. The results of two different particle coalescence submodels show that this process is too slow to account for the growth of primary particles, mainly because of the limited rate of particle collisions. Soot volume fraction predictions on the wings and at lower flame heights are considerably improved by using benzopyrene, due to the different distribution of the soot forming PAH molecule in the flame. The computed number of primary particles per aggregate and the diameters of primary particles agree very well with the experimentally measured values after implementing the dimerization efficiency for PAH collisions, because of the reduced rate of soot inception compared to growth by PAH condensation. Concentrations of major gaseous species and flame temperatures are also well predicted by the model. The underprediction of soot concentration on the flame centerline, observed in previous studies, still exists despite minor improvements.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Etudes théoriques. Données et constantes. Mesures, Theoretical studies. Data and constants. Metering, Combustion. Flammes, Combustion. Flame, Divers, Miscellaneous, Argon, Argón, Biocarburant, Biofuel, Biocarburante, Cinétique, Kinetics, Cinética, Délai inflammation, Ignition delay, Retardo encendido, Effet non linéaire, Non linear effect, Efecto no lineal, Ether, Eter, Etude expérimentale, Experimental study, Estudio experimental, Etude théorique, Theoretical study, Estudio teórico, Hydrogène, Hydrogen, Hidrógeno, Mélange carburant, Fuel mixture, Mezcla carburante, Mélangeage, Mixing, Mezclado, Méthyle éther, Methyl ether, Oxygène, Oxygen, Oxígeno, Simulation numérique, Numerical simulation, Simulación numérica, Temps retard, Delay time, Tiempo retardo, Tube choc, Shock tube, Tubo de choque, Chemical kinetics, Hydrogen blending ratio, Ignition delay time, and Non-linear effect

Ignition delay times of dimethyl ether (DME)/hydrogen/oxygen/argon mixtures (hydrogen blending ratio ranging from 0% to 100%) were measured behind reflected shock waves at pressures of 1.2-10 atm, temperature range of 900-1700 K, and for the lean (φ = 0.5), stoichiometric (φ = 1.0) and rich (φ = 2.0) mixtures. For more understanding the effect of initial parameters, correlations of ignition delay times for the lean mixtures were obtained on the basis of the measured data (XH2 ≤ 95%) through multiple linear regression. Ignition delay times of the DME/H2 mixtures demonstrate three ignition regimes. For XH2 ≤ 80%, the ignition is dominated by the DME chemistry and ignition delay times show a typical Arrhenius dependence on temperature and pressure. For 80% ≤ XH2 ≤ 98%, the ignition is dominated by the combined chemistries of DME and hydrogen, and ignition delay times at higher pressures give higher ignition activation energy. However, for XH2 ≥ 98%, the transition in activation energy for the mixture was found as decreasing the temperature, indicating that the ignition is dominated by the hydrogen chemistry. Simulations were made using two available models and different results were presented. Thus, sensitivity analysis was performed to illustrate the causes of different simulation results of the two models. Subsequently, chemically interpreting on the effect of hydrogen blending ratio on ignition delay times was made using small radical mole fraction and reaction pathway analysis. Finally, highpressure simulations were performed, serving as a starting point for the future work.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Etudes théoriques. Données et constantes. Mesures, Theoretical studies. Data and constants. Metering, Combustion. Flammes, Combustion. Flame, Divers, Miscellaneous, Biocarburant, Biofuel, Biocarburante, Cinétique, Kinetics, Cinética, Ester, Jet gaz, Gas jet, Chorro gas, Liaison double, Double bond, Enlace doble, Modèle cinétique, Kinetic model, Modelo cinético, Modélisation, Modeling, Modelización, Mécanisme réaction, Reaction mechanism, Mecanismo reacción, Oxydation, Oxidation, Oxidación, Réacteur agité, Stirred tank reactor, Reactor agitado, Stéréoisomère trans, Trans stereoisomer, Estereoisómero trans, Hex-3-énoïque acide ester méthyle, Jet-stirred reactor, Mechanism, Methyl-3-hexenoate, and Unsaturated methyl ester

The oxidation of trans-methyl-3-hexenoate (CAS Number 2396-78-3) under 3 different equivalence ratios of 0.6, 1.0 and 2.0 was investigated in a jet-stirred reactor over the temperature range of 560-1220 K at 10 atm and τ = 0.7 s. Mole fractions of 22 species were quantified as the function of temperature under each condition. Compared to the saturated ester methyl hexanoate, the absence of cool flame and negative temperature coefficient regions in the present work reflects the influence of C=C double bond to fuel oxidation. A mechanism based on previous work of methyl hexanoate was developed and validated against the experimental data with satisfactory agreement. Through analysis of the experimental and modeling results, the role of C=C double bond in the oxidation process and the resulting reaction pathways that feature the oxidation of methyl-3-hexenoate are discussed.

General chemistry, physical chemistry, Chimie générale, chimie physique, Energy, Énergie, Sciences exactes et technologie, Exact sciences and technology, Sciences appliquees, Applied sciences, Energie, Energy, Energie. Utilisation thermique des combustibles, Energy. Thermal use of fuels, Etudes théoriques. Données et constantes. Mesures, Theoretical studies. Data and constants. Metering, Combustion. Flammes, Combustion. Flame, Divers, Miscellaneous, Pollution atmosphérique due à l'industrie des combustibles et à leur utilisation, Air pollution caused by fuel industries, Les polluants et leur action, Characteristics of pollutants and their action, Polluant organique persistant, Persistent organic pollutant, Contaminante organico persistente, Alcool, Alcohol, Benzène, Benzene, Benceno, Biocarburant, Biofuel, Biocarburante, Butanol, Cinétique, Kinetics, Cinética, Composé aromatique polycyclique, Polycyclic aromatic compound, Compuesto aromático policíclico, Composé aromatique, Aromatic compound, Compuesto aromático, Dopage, Doping, Emission polluant, Pollutant emission, Emisión contaminante, Etude théorique, Theoretical study, Estudio teórico, Flamme diffusion, Diffusion flame, Llama difusión, Flamme sans prémélange, Non premixed flame, Llama sin premezcla, Formation, Formación, Hydrocarbure, Hydrocarbon, Hidrocarburo, Modèle cinétique, Kinetic model, Modelo cinético, Mécanique fluide numérique, Computational fluid dynamics, Mecánica fluido numérica, Méthane, Methane, Metano, Photoionisation, Photoionization, Fotoionización, Rayonnement UV extrême, Vacuum ultraviolet radiation, Radiación ultravioleta extrema, Spectrométrie masse, Mass spectrometry, Espectrometría masa, Kinetic modeling of benzene and PAH formation, Laminar non-premixed coflow flame, and Synchrotron VUV photoionization mass spectrometry

In order to understand the interactions between butanol and hydrocarbon fuels in the PAH formation, experimental and kinetic modeling investigations were combined to study methane laminar coflow diffusion flames doped with two inlet mole fractions of n-butanol (1.95% and 3.90%) in this work. Mole fractions of flame species along the flame centerline were measured using synchrotron VUV photoionization mass spectrometry. A detailed kinetic model of n-butanol combustion, extended from a recent published n-butanol model, was provided in this work to reproduce the fuel decomposition and the formation of benzene and PAHs in the investigated flames. Numerical simulations were performed with laminar-SMOKE code, a CFD code specifically conceived to handle large kinetic mechanisms. The simulation results were able to follow the observed effects of n-butanol addition from the experimental results. In particular, unsaturated hydrocarbons, especially C6-C16 aromatics, were predicted satisfactorily. The reaction flux analysis revealed that benzene precursors, especially C3 radicals, increase significantly with increasing inlet mole fraction of n-butanol. This enhances the formation of phenyl and benzyl radicals, which are important PAH precursors. Reactions of benzyl, phenyl radicals and benzene with C2-C3 species are the major formation pathways for indene and naphthalene. And PAHs with more carbon atoms are dominantly formed from naphthyl and indenyl radicals.