Emulsion Speed Research Articles

Factors influencing the wetting performance of asphalt emulsion on RAP surface

The wetting performance of asphalt emulsion on reclaimed asphalt pavement (RAP) strongly affects the physical bonding ability of asphalt emulsion-RAP interface. For a more comprehensive understanding on the wetting performance of asphalt emulsion on RAP, many factors affecting the wetting performance of asphalt emulsion on RAP are studied, including the asphalt and emulsifier dosage in asphalt emulsion, RAP asphalt aged degree, and some additives (such as wetting agent, hydrated lime and silane coupling agent). The contact angle of asphalt emulsion on RAP asphalt surface and the other wetting parameters calculated by the surface wetting theory were used to comprehensively analyze the wetting performance. The results show that all of the tested factors have influence on the wetting performance of asphalt emulsions. The grey relational analysis indicates that the wetting agent, hydrated lime and silane coupling agent have significant effects on the wetting performance of asphalt emulsion on RAP. A suitable dosage of wetting agent, hydrated lime modified with silane coupling agent (HL-SCA) can decrease the contact angle and improve the wetting speed of asphalt emulsion on RAP. Meanwhile, the addition of both wetting agent and hydrated lime modified with silane coupling agent can greatly decrease the volume of air voids and improve the indirect tensile strength of cold recycled mixture with asphalt emulsion. Therefore, the wetting agent and the HL-SCA are recommended to improve the wetting performance of asphalt emulsion on RAP and the mechanical performance of cold recycled mixture with asphalt emulsion.

Quality by Design as a Tool in the Optimisation of Nanoparticle Preparation—A Case Study of PLGA Nanoparticles

Nanoparticles can be used as drug carriers in various applications (e.g., in pulmonary drug delivery and mucosal vaccination). For further investigations, such as drug release studies, as well as for cell and tissue targeting, particles with defined properties are needed. The purpose of the study was to show a multi-step systematic method utilising quality by design to ensure the quality of ovalbumin loaded polylactic-co-glycolic acid nanoparticles (OVA-PLGA-NP), which can be delivered to the lung, and to gain knowledge of the preparation method (double-emulsion solvent evaporation method) in an early development process. Within a definitive screening design, several process parameters (OVA, PLGA and stabiliser concentrations, stirring time and stirring speed of inner emulsion and stirring time and stirring speed of double emulsion) were varied to analyse their impact on resulting properties (z-average, PDI, loading efficiency and loading capacity). The results showed that the preparation of the inner emulsion mainly influenced the drug loading, while the parameters of the second emulsifying step controlled the size. Then a central composite response surface design was used to achieve a predictable OVA-PLGA-NP with an average particle size of 700 nm and high drug-loading. This also enabled the demonstration of curvature and interaction of the stabiliser and the PLGA concentration.

Influence by chemical constitution of aggregates on demulsification speed of emulsified asphalt based on UV-spectral analysis

Emulsified asphalt as an indispensable raw material for pavement engineering construction is subjected to various combinations of aggregates and varying environmental conditions leading to uncontrollable demulsification speed. In this respect, this research examined the influence of chemical composition of aggregate on emulsified asphalt demulsification speed. Three representative types of domestic road limestone aggregates with various appearances were studied by chemical analysis method. Experimental results indicate that the Magnesium oxide, alumina, calcium oxide, ferric oxide and silicon oxide were the main chemical compositions of limestone aggregate and their contents varied significantly among different types of aggregate. Ultraviolet spectrophotometry was used to evaluate effects of each chemical component on the demulsification speed of emulsified asphalt. Results indicate that mixing ratio of chemical components has a significant effect on demulsification speed of asphalt emulsion. Magnesium oxide accelerated the demulsification speed of emulsified asphalt, while calcium oxide showed an opposite trend. Iron oxide, alumina and silica had little effect on the speed of demulsification. Finally, grey correlation analysis was performed, and a clear relationship was established. The results which are expressed as the magnesium oxide, alumina, iron oxide and silicon dioxide content with differing ratio in the aggregate affected significantly on the demulsification speed of emulsified asphalt. However, there is no clear relationship between the demulsification speed and emulsified asphalt when the ratio of the calcium oxide content is changed.

Effects of some process parameters on the niflumic acid controlled release polymeric microspheres: Optimization using designs of experiments

AbstractMicroparticles charged by niflumic acid and based on cellulose derivatives as polymeric matrices, that is, ethylcellulose (EC) and mixtures of EC and hydroxypropylmethylcellulose (HPMC), were elaborated using microencapsulation by emulsion‐solvent evaporation technique. The niflumic acid is considered as a poorly water soluble drug, so the main objective of the paper is to use designs of experiment in order to prepare new solid formulations with a large range of size for the drug dissolution enhancement. The possible drug–polymer interaction was investigated by Fourier transform‐infrared spectroscopy, X‐ray diffraction, and differential scanning calorimetric analysis. Some of the process variables, namely, the stirring speed of emulsion, the emulsifier concentration, and the EC:HPMC ratio, were selected and varied. Their main and interactive effects on the microparticles' characteristics were obviously evaluated and discussed using Minitab software 16.1. The obtained microparticles' size (d10) ranged from 196 to 796 μm, and the drug entrapment reached 45% in some formulations. The drug dissolution results showed that the Higuchi's release constant varied from 0.011 to 0.067 min−1/2 and was enhanced especially when the HPMC concentration was increased.

Effect of meat and water temperature and emulsion speed on the industrial process for chicken mortadella

AbstractA 23 factorial design was performed to evaluate the meat and water temperature and the emulsification speed effects in relation to the physical state of animal proteins added to the emulsion process for chicken mortadella production. The dependent variables studied were instrumental texture, pH, protein, lipid, lipid oxidation, and sensory analysis. Under study conditions, the parameter for emulsion speed and water temperature had no significant difference to chemical analyses on the process. Yet, shear force showed a significant difference between treatments in the proportion of raw meat (chilled/frozen). The pH and TBAR values presented no significant difference between treatments, but it had differences during storage period, however inside of acceptable limits. The shear force was influenced by proportions of chilled/frozen raw meat, because the increase in the amount of cooled raw material is beneficial for sensory characteristics. The treatment T9 had a higher acceptability (82.07%), with conditions of process emulsification at 700 rpm, proportion of chilled/frozen raw meat material (1,280/1,280) and added water at 32 °C, resulting in a final 1.5 °C emulsified mass temperature. The proteins, lipid values, and microbiological analysis indicated that the mortadella is found within legislation parameters and the optimized process was successful.Practical applicationsThe increasing demand for food quality product by consumers has made the food industry more competitive, thus making the supply of standardized, quality, and accessible products to the market extremely important. This study provides valuable information for the food industry, especially for emulsified meat products. In the industry, frozen and chilled meat raw materials and water are used to help in mixing with other ingredient. However, attention should be taken on the proportions and temperature that raw materials are used, as these have direct influence on the stability and quality emulsion and, consequently on the final product as well. To maintain the product standard quality, the standardization of operational parameters such as emulsification speed, chilled/frozen meat proportion, and water temperature were performed. The results showed that mortadella texture could be improved by the proportions of chilled/frozen raw material, being well accepted by consumers.

Preparation of urea-formaldehyde paraffin microcapsules modified by carboxymethyl cellulose as a potential phase change material

We prepared spherical microcapsules modified by carboxymethyl cellulose (CMC) with urea-formaldehyde (UF) resin as a shell material with a two-step process by in situ polymerization, and characterized the microcosmic features, chemical structure, and thermal performance of the microcapsules by SEM, FTIR, DSC, and TGA. We studied the effects of different experimental parameters of curing pH, the amounts of the emulsifier and emulsion speed. The CMC-UF microcapsules had good heat resistance and stability. The enthalpy of CMC-UF microcapsules reached 50.33 J g−1. Therefore, CMC-UF resin can be used as a potential wall material of phase change materials.

Investigation the possibility of a new approach of using microcapsules containing waste cooking oil: In situ rejuvenation for aged bitumen

The aim of this contribution is to investigate the possibility of using microcapsules containing waste cooking oil (microWCOs) in situ rejuvenating aged bitumen. MicroWCOs had been successfully fabricated by in situ polymerization using prepolymer of methanol melamine formaldehyde (MMF) as shell material. The properties of morphology, size, shell thickness and mechanical properties had been adjusted by the emulsion speed and core/shell ratios. It was found that MicroWCOs had thermal stability in melting bitumen and survived during repeated temperature changes. Moreover, WCO can easily penetrate into age bitumen as a rejuvenator. The aged bitumen had a trance to recovery its virgin properties after rejuvenated including penetration value, softing point value, and viscosity value.

Demulsification process of asphalt emulsion in fresh cement-asphalt emulsion paste

The demulsification process of asphalt emulsion in fresh cement asphalt emulsion (CA) paste was investigated by measuring the viscosity and the particle size distribution of CA paste. The morphology evolution of asphalt droplets was also observed by optical microscope. Superplasticizer was used to adjust different demulsifying speed of asphalt emulsion in CA paste. Results indicate that the viscosity development of CA paste can reflect the demulsification process of asphalt emulsion in CA paste. The demulsification process of asphalt emulsion in CA paste has two main stages under the continual induction effect of cement hydration. Asphalt droplets in CA paste are firstly coalesced to big droplets, and then recover their adhesive force. In the first stage, the viscosity of CA paste increases little with the changing particle size distribution. However, the viscosity of CA paste increases sharply in the second stage.

Effects of Preparation Process Parameters on Performance of Microencapsulated Paraffin/Polyurea Phase Change Materials

In this paper, Microencapsulated paraffin/polyurea (PU) phase change materials were prepared through an interfacial polymerization method using composite paraffin with solid/liquid mass ratio 3:7 as core materials, 2,4 toluene diisocyanate and ethylenediamine as monomers, NP-10 as an emulsifier. It was investigated the effects of emulsion speed, the amount of emulsifier and polymerization temperature on the particle size and coating efficiency and storage-energy performance of microencapsulated paraffin / PU phase change materials. The results showed when the emulsion speed is 2000r/min and the amount of emulsifier to core material is 6% and the polymerization temperature is 70°C, Microencapsulated paraffin / PU phase change materials have better performance: the melting point of 28.1°C, the enthalpy of 58.4KJ/Kg, coating efficiency of 87.5%, the average particle size of 3~4μm, and the uniform particle size distribution.

Development of 14-MeV Neutron Measurement with Nuclear Emulsion for DT Burning Plasma Diagnostics

A method for the measurement of energetic DT neutron tails resulting from knock-on alpha particles is needed to study plasma physics in a fusion reactor. A nuclear emulsion offers satisfactory performance for the detection of fast neutrons and measures their energies using three-dimensional tracking information. However, the time required for analysis forms a bottleneck in the implementation of this measurement technique. Recently, the analysis speed of nuclear emulsion has dramatically increased because of our development. In this report, we propose the use of nuclear emulsion for DT burning plasma diagnostics using the latest analysis technology and the validation of the methodology. In addition, we discuss the prospects of improving nuclear emulsion technologies for fusion plasma diagnostics.

Interfacial Morphologies of Methanol-Melamine-Formaldehyde (MMF) Shell MicroPCMs/Epoxy Composites

The aim of this work was to fabricate novel microPCMs containing dodecanol by an in-situ polymerization using methanol-modified melamine-formaldehyde (MMF) prepolymer as shell material and investigate the interface morphologies of microPCMs/epoxy composites treated by a simulant thermal process with a 10 times repeated temperature variation. A series of microPCMs were fabricated by 1000-3000 r·min-1 emulsion speed with the PCM contents of 40-70%. Micro-cracks and gaps occurred after a thermal treatment in the interface of microPCMs and epoxy matrix obviously. The internal stress generated by the expansion or shrinking of the microPCMs was the main factor leading to the interface morphology changes and damaged of composites.

Fabrication and interfacial morphologies of methanol–melamine–formaldehyde (MMF) shell microPCMs/epoxy composites

Microcapsules containing phase change materials (microPCMs) have many potential applications because of their thermoregulation or thermosaving abilities. At the same time, it is still essential to understand the interface stability of microPCMs/polymer composites during a thermal transmission. The aim of this work was to fabricate novel microPCMs containing dodecanol by an in situ polymerization using methanol-modified melamine–formaldehyde (MMF) prepolymer as shell material and investigate the interface morphologies of microPCMs/epoxy composites treated by a simulant thermal process with a ten times repeated temperature variation. A series of microPCMs were fabricated by 1,000–3,000 r·min−1 emulsion speed with the PCM contents of 40–70%. The average diameter, melting temperature, and encapsulation efficiency of microPCMs were 1–16 μm, 19.5 °C, and 97.4%, respectively. Tests results indicated that the properties of the microPCMs were greatly affected by core/shell ratios and emulsification stirring rates of preparation conditions. With the increasing of stirring rates, the average diameters of microPCMs were sharply decreased. The encapsulation efficiency (E e) values of microPCMs increased with the increasing of stirring rates. The contents of PCM in microcapsules (C t) and the average diameter of microPCMs both affected the interface morphologies of microPCMs/epoxy composites after the repeated thermal treatments. Microcracks and gaps occurred after a thermal treatment in the interface of microPCMs and epoxy matrix obviously. The internal stress generated by the expansion or shrinking of the microPCMs was the main factor leading to the interface morphology changes and damaged of composites.

Evaluation of Absorbing Chromophores Used in Tissue Phantoms for Quantitative Photoacoustic Spectroscopy and Imaging

In this paper, the optical properties of absorbing compounds that are often used to construct tissue phantoms for quantitative photoacoustic spectroscopy and imaging are investigated. The wavelength dependence of the optical absorption of inorganic chromophores, such as copper and nickel chloride, and organic chromophores, such as cyanine-based near infrared dyes, was measured using transmittance spectroscopy and compared with that determined using photoacoustic spectroscopy. In addition, the relative change in the Gruneisen coefficient of these solutions with concentration was determined. The sound speed of aqueous gels and lipid emulsions as a function of concentration was also measured. It was found that copper and nickel chloride are suitable chromophores for the construction of photoacoustic tissue phantoms due to their photostability. By contrast, organic dyes were found unsuitable for quantitative photoacoustic measurements due to optically induced transient changes to their absorption spectrum and permanent oxidative photobleaching.

Extraction of alcohol using emulsion liquid membrane consisting of paraffin oil as an organic phase and lecithin as a surfactant

AbstractBACKGROUND: This paper reports on the use of a liquid emulsion membrane involving paraffin light oil as membrane phase and lecithin as surfactant for the extraction of alcohol from anthocyanin extract and simulated pineapple wine.RESULTS: The extraction of alcohol was found to depend on the many factors such as surfactant concentration, contact time, stirring speed, stirring time, and ratio of membrane emulsion to feed volume. Results showed that optimum conditions for maximum alcohol extraction (25%) were lecithin concentration 3%, contact time 20 min, stirring speed 250 rpm and ratio of membrane emulsion to feed volume 1:2. Multistage extraction using this liquid emulsion membrane was found to completely remove alcohol from anthocyanin extract and from simulated pineapple wine in seven stages and five stages, respectively.CONCLUSION: This liquid emulsion membrane was found to be a useful method for the extraction of alcohol from aqueous feed. Copyright © 2009 Society of Chemical Industry

Environmentally Friendly Polyurea Microcapsules of Pesticides by PVA Mediated Interfacial Polymerization

Microcapsules containing agrochemical pesticides used to control insects have attracted considerable interest for the last three decades in the search for reducing intrinsic toxicities, overconsumption, and ecological problems that have been caused generally by conventional pesticides. Biodegradable polyurea microcapsules containing pesticides such as ethyl parathion, benlate, and daconyl were prepared by the interfacial polymerization of polyisocyanate monomers with polyamines. In the process of microencapsulation with various emulsifying agents under the condition of high to medium concentration, polysulfonated emulsifiers such as lignosulfonate and styrenesulfonate sometimes failed to produce microcapsules because of random solidification of the aqueous mass leaving a serious problem of reproducibility. A protective colloid, polyvinylalcohol (PVA), was examined to prepare the stable high-concentrated emulsion under various conditions. Capsule slurry with 33% active ingredient was successfully obtained by the use of ca. 1% PVA as a protective colloid. In the case of the capsule with 42% active ingredient, the wall-forming reaction produced microcapsules, which turned out to be considerably coagulated or sometimes resulted in the failure of producing microcapsules. However, it was found that the mixed emulsifier of 10% of PVA and 90% of poly (sodium4-styrenesulfonate (PSS) produced stable emulsion and successfully led to microcapsules in high concentration under various conditions without any problems of reproducibility. The particle size distribution of the microcapsules was not much influenced by surfactants, and the size and distribution of the obtained microcapsules were directly affected by the agitation speed of emulsion.

International dictionary of broadcasting and film

The language terms A-Z British - metric conversion table magnetic tape width standards magnetic tape speed standards phonograph speeds film length standards negative, sound, print and television recording films film width standards film projection speed table of frequencies frequency bands radio bands television channels film emulsion speed conversion table televison systems worldwide national and international news agencies.

Effects of niobium filtration and constant potential on image quality in dental radiography. 2. Objective assessment.

The effects of niobium filtration and constant potential on image quality were explored by asking observers to identify numbers of circular areas of small density differences in zones of high and low density. Successful identification was related negatively to half-value layer. This relationship was particularly strong in the case of self-rectified units without additional niobium filtration and the constant potential units (r2 = 0.994, P < 0.0005). Constant potential had no effect other than in relation to half-value layer. Additional niobium filtration detracted from successful identification, but slightly less than would be predicted by the half-value layer. Whether this difference is significant or relevant has not been established. The findings of this study, in conjunction with our previous investigations, have failed to demonstrate any clear indications for preferring constant potential supply over self-rectification or for using niobium as an additional filter material. Half-value layer has been shown to be a reliable indicator of the effects of beam quality on emulsion speed, attenuation in water, and image quality. It appears that the methods employed to change the beam quality have no specific effects.

Emulsion Speed Rating Systems

Early methods for determining and expressing film speeds were empirical. Hurter and Driffield’s classic paper of 1890 described the “characteristic cuwe” and established the first rigorous criterion for film speed based on scientific principles.Criteria used have been based on threshold, inertia, fixed density, minimum useful gradient, and fractional gradient. The various criteria and systems based on them, some of which preceded, but most of which followed from Hurter and Driffield's work, and which have been used for longer or shorter periods of time since then, are reviewed.

The photolysis of small silver halide particles

Monolayer coatings of monodisperse silver halide microcrystals of general formula AgCl x Br 1- x with 0 ≼ x ≼ 1, were prepared and measurements carried out in order to determine the efficiency of photolysis. The effect of crystal size was studied: it is well known that the speed of photographic emulsions increases with the size of the emulsion crystals. Crystal edge length was varied from 0.3─1.0 μm. It was shown that, within this range, size has no effect on the quantum yield of photolysis. The speed increase therefore arises simply because larger crystals collect more photons, and the minimum number of photons required to make a crystal developable is attained more rapidly. The effects of sensitization were studied: it was shown that the effect of gold is not to be understood purely in terms of the latent image being smaller if it is composed of gold rather than silver, but that in addition the efficiency of photolysis increases. The results of the investigation are shown to be in agreement with the Gurney─Mott model. The remarkable difference in hole self-trapping at low temperatures between AgCl and AgBr is shown to account for differences in photo­graphic behaviour.

A Century of Modern Development

AbstractSulphite was introduced into the alkaline developer, in 1881–82, to prevent the staining of gelatin emulsions by oxidized pyrogallol. It has proved to play an indispensable part in the functioning of development by benzenoid developing agents, and a centenary opportunity is taken to review development in relation to this fact. Very little fundamental progress has been made in development over the century. The developers available in 1882 could already achieve virtually full emulsion speed, though at high contrast, and this is demonstrated with an ASA 400 film of today. Adequate chemicals for viable development in monochrome or colour have been available since 1892. The demonstration with the ASA 400 film is used to establish the kinetics of two modes of development: (1) Where development proceeds as if the surface area of the developing centre controls the rate, development has to be full if the least-exposed grains are to develop, and high speed goes with high contrast. (2) Where development proc...