Tri-component Mixture Research Articles

Experimental study of droplet vaporization for conventional and renewable transportation fuels: Effects of physical properties and chemical composition

As part of the global energy transition, an increasing number of sustainable liquid fuels with a wide range of physical and chemical properties becomes available for gas turbine and IC engines. For an optimal design and operation of these engines, an improved understanding of the effects of fuel properties on atomization, vaporization and combustion kinetics is required. The present work provides a comprehensive experimental study of fuel effects on droplet vaporization for numerous conventional and alternative fuels. The study employs a recently developed flow channel, where free-falling droplets with initial diameters of D≈77μm vaporize under technically relevant gas temperatures Tg of up to 1300 K. The evolution of droplet diameters over travel distance and time is measured using microscopic shadow imaging. A total of 13 single fuel components, five bi- and tri-component mixtures, six conventional and alternative jet fuels and mixtures thereof, and three IC engine fuels and mixtures thereof have been tested under well-reproducible ambient conditions. The fuels represent a wide range of chemical classes such as n-alkanes, iso-alkanes, cycloalkanes, aromatics, alcohols and oxymethylene ethers, and most of them were measured for the first time with realistic D and Tg. The results for the single fuel components reveal in detail the temperature-dependent effects of physical properties such as boiling point Tb, liquid density ρl and enthalpy of vaporization Hv. In particular, it was found that for high gas temperatures of about 1250 K, the vaporization rate is almost completely determined by the product of Hv and ρl. By comparison with the results for single n-alkanes, the measurements for bi- and tri-component mixtures accurately characterize the preferential vaporization of individual fuel components over droplet lifetime. The results for various multi-component fuels reveal complex interplays of preferential vaporization and temperature-dependent influences of physical properties. It is shown that the vaporization for conventional and corresponding alternative fuels can differ significantly. Finally, the droplet vaporization is characterized for mixtures of PRF90+ethanol and ethanol+water, which exhibit a non-ideal vapor–liquid equilibrium.

Monomer-Promoting Asymmetric Kinetic Resolution-Alternating Copolymerization To Afford AAB-Type Copolyesters.

Living copolymerization of mixed monomers can enrich the diversity of copolymer materials with well-defined performance via controlling both monomers and stereosequences. However, periodic sequence-controlled living copolymerization of same-type monomers with more than two components in synthetic polymer science remains a challenge. In this work, a new method of monomer-promoting asymmetric kinetic resolution-alternating copolymerization can let a tricomponent mixture of l-lactide (S,S-LA or l-LA) and two enantiomeric isomers of racemic tropic acid cyclic esters (tropicolactone) be polymerized into sequence-controlled -(ASASBS)n- type biodegradable copolyesters (the subscript S presents the configuration and A and B present lactic acid units and tropic acid units, respectively), and diblock copolymers of -(ASASBS)n-b-(ARARBR)n- can further be obtained upon addition of R,R-LA (d-LA). Compared to previous asymmetric kinetic resolutions of racemic chemicals via polymerization or organic reactions, no enantiopure catalyst/initiator is required in this system. After the resolution and alternating copolymerization of S,S-LA and rac-tropicolactone, the ee value of unreacted tropicolactone can reach 99.4%. The alternating probability between tropicolactone and lactide monomers is more than 96% in periodic sequence polymers of -(ASASBS)n-. The tetracomponent mixture of rac-lactide and rac-tropicolactone can be copolymerized into an alternating copolymer with a -((ASASBS)x-ran-(ARARBR)y)n- structure, in which the stereoselective linkage probability of 95% after S,S-lactide (R,R-lactide) followed by S-tropicolactone (R-tropicolactone) keeps very high too.

AN ALTERNATIVE FOR VALORIZATION OF WASTES AS ENERGY SOURCE

The efficient use of renewable energy resources is one of the most important elements of energy sustainability at the European Union level. The growing demand for energy will continue to support the use of other materials as resources of energy than conventional ones, coal, crude oil and natural gas. This paper investigates the feasibility of valorizing wastes with energetic potential in a multi-component alternative solid fuel. Biomass - vegetable waste (BW), meat and bone meal (MBM) and slag/bottom ash from lignite combustion, in combination with a low-rank, lignite, was used to prepare tri-component mixtures (MBM+Lignite +Slag and MBM+BW+Lignite) indifferent variable proportions, and further characterized to assess their potential for use as energy source. The thermal behavior of the mixtures was assessed by thermogravimetric analysis; the resulting ashes were characterized by scanning electron microscopy.Also, the environmental impact as emissions level after their combustion was considered. In terms of an effective way of removing wastes (e.g. slag/bottom ash and MBM), the most promising proposed solid mixture was the combination MBM(50%): Lignite(25%): Slag (25%), with a high energetic value, > 2700 kcal/kg, a volatile matter content > 35 %wt, and the ash in half amount compared to its initial mass. Thestudy’s findings illustrate the possibility of turning solid waste to raw material by converting them into energy, and promote the development of long-term waste management and recovery solutions.

Inhibition of benzene, toluene, phenol and benzoate in single and combination on Anammox activity: implication to the denitrification-Anammox synergy.

A previous study demonstrated that denitrification synergized with Anammox could accelerate the anaerobic degradation of benzene. The inhibitory effects of benzene, toluene, phenol and benzoate in single and combination on Anammox activity were investigated by short-term batch tests. The results indicated that the inhibition of single compounds on Anammox could be well fitted with the extended non-competitive and Luong inhibition kinetic models. The inhibitions of the individual compound were in order as follows: benzene > toluene > phenol > benzoate. The joint inhibitions of bi-component mixtures of benzene with toluene, benzene with phenol and benzene with benzoate on Anammox activity were additive; the joint inhibition of a tri-component mixture (benzene, toluene and phenol) was partly additive; and the joint inhibition of a multicomponent mixture (benzene, toluene, phenol and benzoate) was synergistic. The effect of benzoate on the denitrification-Anammox synergy for benzene degradation was evaluated using a long-term test. Although the average rate of benzene degradation decreased by 13% with the addition of 10mgL-1 benzoate, the average rate of NO3- and NH4+ increased by approximately 1- and 0.56-fold, respectively, suggesting that benzoate favors the stability of the denitrification-Anammox synergy. The carboxylation of benzene would be a more favorable pathway for the anaerobic degradation of benzene under denitrification synergized with Anammox.

Laminar burning velocities at elevated pressures for gasoline and gasoline surrogates associated with RON

The development and validation of a new gasoline surrogate using laminar flame speed as a target parameter is presented. Laminar burning velocities were measured using a constant-volume spherical vessel with ignition at the center of the vessel. Tested fuels included iso-octane, n-heptane, toluene, various mixtures of primary reference fuels (PRFs) and toluene reference fuels (TRFs) and three gasoline fuels of 70, 85 and 95 RON (FACE J, C and F) at the initial temperature of 358K and pressures up to 0.6MPa in the equivalence ratio ranging from 0.8 to 1.6. Normalized laminar burning velocity data were mapped into a tri-component mixture space at different experimental conditions to allocate different gasoline surrogates for different gasoline fuels, having RON of 70, 85 and 95. The surrogates of TRF-70-4 (17.94% iso-C8H18+42.06% n-C7H16+40% C7H8), TRF-85-1 (77.4% iso-C8H18+17.6% n-C7H16+5% C7H8), and TRF-95-1 (88.47% iso-C8H18+6.53% n-C7H16+5% C7H8) of RON 70, 85 and 95, respectively, are shown to successfully emulate the burning rate characteristics of the gasoline fuels associated with these RONs under the various experimental conditions investigated. An empirical correlation was derived to obtain laminar burning velocities at pressures that are experimentally unattainable as high as 3.0MPa. Laminar burning velocities were comparable to the simulated values for lean and stoichiometric flames but they were relatively higher than the simulated values for rich flames. A flame instability assessment was conducted by determining Markstein length, critical Pecklet number, and critical Karlovitz number at the onset of flame instability.

Preparation, characterization and thermal degradation study of poly(amide imide)s based on tri-component mixture of PMDA/BTDA, diamines and acid chloride

A series of poly(amide imide)s (PAIs) having alternate (amide–amide) and (imide–imide) units (polymers 1–14 and 22–35), and random distribution of amide-imide linkages (polymers 15–21 and 36–42) were prepared by low temperature solution polymerization of benzene-1,2,4,5-tetracarboxylic dianhydride (PMDA)/benzophenone-3,3′,4,4′-tetracarboxylic dianhydride (BTDA), diamines (cyclic and aromatic) and acid chloride in dimethylforamide. All the polymers were readily soluble in polar aprotic solvents with inherent viscosities in the range of 0.134–0.878. The process of cycloimidization of poly(amide amic acid)s (PAAs) to PAIs was investigated by TGA and FT-IR techniques at four different temperatures i.e., 175, 200, 225, and 260 °C. The rate of cycloimidization was calculated by taking into account the theoretical weight loss (WT), obtained from [n × Mw (H2O)/Mw (RU)] W, where Mw (H2O) molecular weight of water, W weight of PAA taken for TGA, Mw (RU) the molecular weight of repeat unit of PAA, n number of water molecules eliminated per repeat unit of PAA upon cycloimidization. For a particular diamine, the extent of percentage cycloimidization at the end of the isothermal heating was higher for PAAs containing trimellitic anhydride chloride (TMAc) unit, irrespective of the nature of the dianhydride and diamine. Thermal and thermooxidative degradation of PAIs was investigated by TGA in nitrogen and oxygen atmosphere. The initial decomposition temperatures (IDT) of polymers are above 260 °C, and vary widely (from 260 to 501 °C) depending upon the structure of the polymer backbone. PAIs containing TMAc exhibited higher thermal stability as compared to those polymers having diacid chloride units, in both N2/O2 atmospheres.

Dielectric Permittivity and Viscoelastic Measurements οf Two Tricomponent Mixtures Consisting οf Laterally Fluorinated Terphenyl Derivatives

Two tricomponent room temperature nematic eutectic mixtures ABC and ABD with laterally uorinated constituents A and B were prepared as base mixtures for vertically aligned mode LCD's. The physical properties of these mixtures viz. birefringence, dielectric anisotropy, bend elastic constant, relaxation time and rotational viscosities were determined in order to compare with the optimum values required to achieve the target speci cations of VA mode materials. The dielectric anisotropy, ∆e, and optical birefringence, ∆n, of these mixtures were found to be in the range of ( 1.3 to 1.4) and (0.13 and 0.14), respectively, at around 20 ◦C. The gure of merit for the ABD mixture has been found to be higher than that of ABC mixture throughout the entire temperature range. The pretilt angle e ect in the physical parameters has also been studied. At T = 20 ◦C, the response time decreases to 25% and 35% for mixture ABC for 2◦ and 5◦ pretilt respectively in comparison to zero pretilt. On the other hand, at the same temperature for the ABD mixture these values are reduced by 16% and 35%, respectively.

Efficacy of six neonicotinoid insecticides alone and in combination with deltamethrin and piperonyl butoxide against pyrethroid-resistantAedes aegyptiandAnopheles gambiae(Diptera: Culicidae)

In this study, carried out on pyrethroid-resistant Aedes aegypti and Anopheles gambiae, different combinations containing pyrethroid deltamethrin, piperonyl butoxide (PBO) synergist and six neonicotinoid insecticides (acetamiprid, nitenpyram, thiamethoxam, clothianidin, imidacloprid and thiacloprid) were tested. The bioassays were carried out by tarsal contact on impregnated paper on Ae. aegypti and with impregnated pieces of netting on An. gambiae. The combination of deltamethrin and PBO was synergistic against pyrethroid-resistant Ae. aegypti (LHP) and An. gambiae (VKPR) strains, with 43 and 57% mortality respectively, versus 17 and 12% with deltamethrin alone. On LHP Ae. aegypti, the deltamethrin + PBO + neonicotinoid mixtures generated insecticide efficacies that were either greater (group 1) or lower (group 2) than the deltamethrin + PBO mixture. The tricomponent mixtures made with thiamethoxam, nitenpyram and thiacloprid (70.7, 64.9 and 55.9% mortality respectively) belong to group 1. Group 2 consists of mixtures made with imidacloprid, clothianidin and acetamiprid (28.9, 32.9 and 34.3% mortality respectively). The nettings impregnated with the three tricomponent mixtures of group 1 confirmed the excellent efficacy of these mixtures against An. gambiae VKPR (87-89% mortality). Deltamethrin + PBO + neonicotinoid (group 1) mixtures induce interesting, efficient synergies, most valuable for the management of mosquito resistance to insecticides.

Dual-site Langmuir modeling of the liquid phase adsorption of linear and branched paraffins onto a PVDC carbon molecular sieve

The liquid phase adsorption equilibrium and kinetics of three paraffins onto a carbon molecular sieve at a temperature of 30°C were obtained, namely n-heptane (nC7), 2-methylheptane (2MC7), and 2,5-dimethylhexane (25DMC6), as well as a mixture of these three components in a non-adsorbing 2,2,4-trimethylpentane (224TMC5) solvent. The adsorption capacities of the individual hydrocarbons ranged from 1.6 to 2.3mmol/gads. The total adsorption capacity of the molecular sieve in the tri-component mixture was 2.0–2.1mmol/gads, where the individual adsorption capacity of the nC7, the 2MC7 and the 25DMC6 was approximately 0.9, 0.7 and 0.4mmol/gads, respectively, with small variations depending on the initial concentration of the hydrocarbons. The combined results were modeled as a dual-site Langmuir kinetic model where two consecutive adsorption processes were considered, namely the non-selective adsorption of molecules in the meso-supermicropores, followed by the movement of these adsorbed molecules into even smaller pores through the barriers of the micropore mouths. The results obtained in this study showed that the selective part of the adsorption process was crucial for achieving the observed kinetic separation, and the model could be used to satisfactorily describe the observed adsorption.

19F NMR of linear N,N-difluoroaminoalkanes

Whereas most N,N-difluoroaminoalkanes exhibit a single 19F resonance at about +50ppm, the tri-component mixtures of both N,N-difluoroaminopentanes and N,N-difluoroaminohexanes exhibited a more complex pattern. The individual 1-N,N-difluoroamino-, 2-N,N-difluoroamino- and 3-N,N-difluoroaminopentanes have been synthesized and their separated resonances are reported.

Determination of Orientational Order Parameters of Two Tri-Component Mixtures from Optical Birefringence and X-Ray Diffraction Measurements

Two tri-component mixtures as base mixtures for vertically aligned mode LCD’s were prepared. The eutectic compositions were theoretically estimated and experimentally verified from differential scanning calorimetry studies. A room temperature nematic mixture with fairly broad operating range emerged from each of the tri-component mixtures. The optical birefringence of these mixtures at the eutectic composition was measured as a function of temperature. X-ray diffraction measurements were done on these mixtures to obtain the orientational order parameters as a function of temperature. The order parameter values were also determined from birefringence measurements and the results were compared with mean field theory. Structural parameters like intermolecular distance and apparent molecular length have also been determined.

Combining Piperonyl Butoxide and Dinotefuran Restores the Efficacy of Deltamethrin Mosquito Nets Against Resistant Anopheles gambiae (Diptera: Culicidae)

One strategy suggested for the management of mosquito insecticide resistance consists of combining a pyrethroid with an insecticide that has a different mode of action. To restore the efficacy of deltamethrin (pyrethroid) against pyrethroid-resistant strain of Anopheles gambiae Giles (VKPR: homozygous Kdr), deltamethrin was combined with the neonicotinoid insecticide dinotefuran and piperonyl butoxide (PBO). Bednets impregnated with deltamethrin, dinotefuran, and PBO alone and in combination were tested in the laboratory. Knockdown (KD) and mortality were measured using WHO cone tests on susceptible and pyrethroid-resistant adult mosquitoes. The combination of deltamethrin and PBO was synergistic against resistant female An. gambiae (58.2% mortality). Both mortality and knockdown time (KDt(50/95) values) of the tricomponent mixture on the VKPR strain were similar to the insecticidal activity of deltamethrin on the pyrethroid-susceptible KIS strain (98.8 and 100% mortality, respectively). The three-compound mixture of deltamethrin + PBO + dinotefuran showed an insecticidal efficacy greater than the deltamethrin + PBO mixture to the extent of completely restoring the efficacy of deltamethrin on pyrethroid-resistant An. gambiae.

Attaining optimal dyeability and tensile properties of polypropylene/poly(ethylene terephthalate) blends with a special cubic mixture experimental design

AbstractIn this investigation, we attempted to enhance the dyeability of polypropylene (PP) with disperse dyestuffs without adversely affecting its tensile properties. To this end, a special cubic experimental design was used to predict the effect of variations in the properties of a tricomponent mixture composed of PP, poly(ethylene terephthalate) (PET), and maleic anhydride grafted polypropylene (PP‐g‐MA) on the dyeability and tensile properties of the resultant polymer blend. The results illustrate that there seemed to be critical PET content, above which the blend's dye uptake tended to remain constant, but the tensile properties were adversely affected. Further analysis of the results indicated that the PP/PET/PP‐g‐MA blends in which the PET and PP‐g‐MA contents were in the range 10–15 and 4–5 wt %, respectively, gave maximal dye uptake and desirable tensile properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

A multicomponent model for biofilm-drug interaction

We develop a tri-component model for the biofilm and solvent mixture, in which the extracellular polymeric substance (EPS) network, bacteria and effective solvent consisting of the solvent, nutrient, drugs etc. are modeled explicitly. The tri-component mixture is assumed incompressible as a whole while inter-component mixing, dissipation, and conversion are allowed. A linear stability analysis is conducted on constant equilibria revealing up to two unstable modes corresponding to possible bacterial growth induced by the bacterial and EPS production and dependent upon the regime of the model parameters. A 1-D transient simulation is carried out to investigate the nonlinear dynamics of the EPS network, bacteria distribution, drug and nutrient distribution in a channel with and without shear. Finally, the transient biofilm dynamics are studied with respect to a host of diffusiveproperties of the drug and nutrient present in the biofilm.

デンプンを用いた乾式コーティング法による難水溶性薬物の溶解性改善

The dissolution property of poorly water-soluble drug, flurbiprofen, was improved by using dry coating method with tri-component mixture containing starches as core-particles. The mixtures composed of water-soluble additives (lactose, hydroxypropyl cellulose), or light anhydrous silicic acid and flurbiprofen were prepared. These mixtures and corn starch were co-ground in a planetary ball mill and surface of the starch were dry-coated by the mixtures. Appearance, yield, dispersibility in water, crystallinity and drug dissolution property of the coated samples were evaluated and the optimal formulation which improved the dissolution property of poorly water-soluble flurbiprofen was determined.

SIMULATION OF CHROMATOGRAPHIC PROFILES FOR MULTICOMPONENT MIXTURES OF AROMATIC COMPOUNDS

The aim of this work concerns the reconstruction of the elution profiles obtained in HPLC separation of aromatic compound mixtures. In particular, the proposed model represents the migration of tricomponent mixtures of alkylbenzenes (a class of compounds belonging to gasoil) in a chromatographic system. The obtained profiles are compared with experimental data and show the possibility to use the model as a tool for acquiring reliable and practical information on the peak identification in HPLC analysis.

EXPERIMENTAL STUDIES AND ESTIMATES OF THE EXPLOSION LIMIT OF SOME ENVIRONMENTALLY FRIENDLY REFRIGERANTS

ABSTRACT This paper develops diagrams of the explosion limit of binary mixtures of R125 and one of six refrigerants based on experimental studies and proposes a mathematical model to calculate the concentration and the explosion limit of a tricomponent mixture containing one nonflammable component. The explosion limit of the mixtures can be estimated by using these diagrams.

Mixed supercrystalline structures in mixtures of ABC triblock and ab(bc) diblock copolymers, 2. Lamellar structures in tricomponent mixtures

The theory of lamellar superstructures in ternary mixtures of ab and bc diblock and linear ABC triblock copolymers under the condition of strong segregation between chemically different blocks is developed. This system is considered using Alexander-de Gennes (box) and self-consistent field (SCF) models. The theory predicts the possibility of phase segregation in the microphase-segregated superstructures. It is shown that the ABC triblock copolymer has unlimited capacity with respect to ab and bc diblock copolymers which include cooperatively into mixed lamella.