Emulsion Liquid Research Articles

WELL SCREEN FOR THE TECHNOLOGY OF WATER- CUT OIL DOWNHOLE SEPARATION

Background According to a number of studies, the efficiency of the preliminary water discharge units in terms of the quality of the discharged water and the amount of residual water in oil depends on the degree of destruction. With an increase in the latter, the efficiency of the pre-dumping installations increases significantly. In oil-gathering reservoirs, due to the relatively low flow rates, emulsification of liquids practically does not occur and, moreover, conditions are created for the deposition of large water droplets along the cross-section of the pipeline and the formation of a continuous underlying layer of water, which can be captured by ground filters. The most intensive emulsification of formation fluids occurs in the working bodies of electric centrifugal pumps in production wells. The emulsions formed in these pumps have the greatest stability and interface. Aims and Objectives To prepare liquids for stratification in pre-discharge units, it is most expedient to install filters in separator wells before electric centrifugal pumps. The authors consider that the disadvantage of these installations is the insufficient quality of water treatment, since water is not filtered from solid suspended particles and oil globules. To solve this problem, it is proposed to install a volumetric filtration filter made from a package of brush disks and located on a tubing string in a downhole water discharge unit. Results The results of bench tests of the structure of the downhole volumetric filtration filter for the downhole separation technology are presented, the layouts of the main submersible equipment are shown. It has been substantiated that the use of this filter will allow: o to increase the productivity of wells due to the efficiency of gravitational stratification of water-oil liquid on the developed surface of the filter brush discs; o reduce the cost of the filter cleaning operation in comparison with known filters; o to increase the degree of purification of the product (water) from impurities; o prevent erosional destruction of the inner surface of the tubing string.

Development and Validation of a Method for the Analysis of Zinc Oxide in Cosmetic Matrices by Flame Atomic Absorption Spectroscopy

A fast and simple method for the extraction and Flame Atomic Absorption Spectroscopy (FAAS) quantification of ZnO in different cosmetic matrices, including lipsticks, water-in-oil foundations, and oil-in-water creams, was developed and validated, according to the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) and the United States Pharmacopeial Convention guidelines. The sample preparation consisted of an ultrasound-assisted ethanolic extraction of ZnO followed by digestion with 1 M nitric acid (HNO3). Samples were analyzed by Flame Atomic Absorption Spectroscopy (FAAS). Specificity, linearity, the limit of detection (LOD), the limit of quantification (LOQ), sensitivity, precision, and accuracy parameters were studied. The robustness of the method was evaluated with a five-variable Youden–Steiner model. The method was specific for ZnO, and the extraction procedure did not affect the stability of the signal compared to the background. The method was linear in the range 0.2–1.0 mg/L with LOD/LOQ values equal to 0.0156 (mg·L−1)/0.0473 (mg·L−1), 0.0098 (mg·L−1)/0.0297 (mg·L−1), 0.0113 (mg·L−1)/0.0341 (mg·L−1), and 0.0131 (mg·L−1)/0.0397 (mg·L−1), respectively, for raw material, lipstick, liquid foundation, and emulsion matrices. Regarding precision, the %RSD values were below 3.0% for repeatability and intermediate precision. Global reproducibility RSD was below 8.0% for all matrices. The percentage of recovery was not statistically different from 100% in all cases. The final concentration was found to be a critical variable for all matrices except for the raw material. The variables associated with the extraction step (ethanol volume, bath temperature, and extraction time) were critical in the extraction of liquid foundations and cream emulsions. The method reduces the number and concentration of mineral acids spent on the digestion of ZnO, and its application is extendable to raw materials. This development is an adequate tool for routine analysis and cosmetic quality control of chemically different products that contain ZnO as ultraviolet radiation (UV) filter, to guarantee regulatory compliance and ensure the safety and efficacy of products delivered to consumers.

A Short Review on skin cares Cream

In this article we studied in creams are topical preparation for the applied on the skin. “viscous liquid or semisolid emulsion is called as cream" The topical formulation is used to introduced the drug into the skin or mucous membrane of skin. And also for the different skin disorders. In this article we also discussed in the types of creams and there examples. Then studied the creams is pharmaceutical product because they prepared on the basis of technology in pharmaceutical industry. They may be medicated or non medicated or they are herbal, ayurvedic & allopathic. Skin reflects origins, lifestyle, age and state of health. Skin creams are mainly classified as O/W & W/O. Then they will be emmulsified by emulsifying agent. In the skin creams various vitamins are used like vit A, E, & D3 are the synthetic and fatty acid (EFA) are used. In which also used the water, oil, fat, Waxes, colours, glycol and etc. Creams have the number of advantages like easy apply, more effective compares to other avoid risk, drugs are absorb perfectly but in which disadvantages also present like, skin irritation can occur due to adjuent, large size drug are not absorb perfectly and etc.

Buttermilk as Encapsulating Agent: Effect of Ultra-High-Pressure Homogenization on Chia Oil-in-Water Liquid Emulsion Formulations for Spray Drying.

Functional foods are highly demanded by consumers. Omega-3 rich oil and commercial buttermilk (BM), as functional components, used in combination to produce emulsions for further drying may facilitate the incorporation to foods. Ultra-high-pressure homogenization (UHPH) has a great potential for technological and nutritional aspects in emulsions production. The present study aimed to examine the potential improvement of UHPH technology in producing buttermilk-stabilized omega-3 rich emulsions (BME) for further drying, compared with conventional homogenization. Oil-in-water emulsions formulated with 10% chia: sunflower oil (50:50); 30% maltodextrin and 4 to 7% buttermilk were obtained by using conventional homogenization at 30 MPa and UHPH at 100 and 200 MPa. Particle size analysis, rheological evaluation, colloidal stability, zeta-potential measurement, and microstructure observations were performed in the BME. Subsequent spray drying of emulsions were made. As preliminary approximation for evaluating differences in the homogenization technology applied, encapsulation efficiency and morphological characteristics of on spray-dried emulsions (SDE) containing 21.3 to 22.7% oil content (dry basis) were selected. This study addresses the improvement in stability of BME treated by UHPH when compared to conventional homogenization and the beneficial consequences in encapsulation efficiency and morphology of SDE.

Deep eutectic solvent-based emulsification liquid-liquid microextraction for the analysis of phenoxy acid herbicides in paddy field water samples.

An emulsification liquid–liquid microextraction (ELLME) method was successfully developed using phenolic-based deep eutectic solvent (DES) as an extraction solvent for the determination of phenoxy acid herbicides, 3,6-dichloro-2-methoxybenzoic acid (dicamba) and 2-methyl-4-chlorophenoxyacetic acid (MCPA) in environmental water samples. Five different phenolics-based DESs were successfully synthesized by using phenol (DES 1), 2-chlorophenol (DES 2), 3-chlorophenol (DES 3), 4-chlorophenol (DES 4) and 3,4-dichlorophenol (DES 6) as the hydrogen-bond donor (HBD) and choline chloride as the hydrogen-bond acceptor (HBA). The DESs were mixed at 1 : 2 ratio. A homogeneous solution (clear solution) was observed upon the completion of successful synthesis. The synthesized DESs were characterized by using Fourier transform infrared and nuclear magnetic resonance (NMR). Under optimum ELLME conditions (50 µl of DES 2 as extraction solvent; 100 µl of THF as emulsifier solvent; pH 2; extraction time 5 min), enrichment factor obtained for dicamba and MCPA were 43.1 and 59.7, respectively. The limit of detection and limit of quantification obtained for dicamba were 1.66 and 5.03 µg l−1, respectively, meanwhile for MCPA were 1.69 and 5.12 µg l−1, respectively. The developed ELLME-DES method was applied on paddy field water samples, with extraction recoveries in the range of 79–91% for dicamba and 82–96% for MCPA.

Intensified Hydrodynamic Cavitation-Based Process for the Production of Liquid Emulsion Membrane (LEM) for the Extraction of Chromium(VI) Ions

The present work deals with the production of liquid emulsion membrane (LEM) accomplished by applying hydrodynamic cavitation-based process for the extraction of Chromium(VI) from wastewater. Aliquat 336 was used as the carrier during membrane transport. Diesel and Span 80 were used as diluent and emulsifier, respectively. NaOH (as a stripping agent in the internal phase) was used in emulsion preparation with the use of orifice (1 mm diameter)-based hydrodynamic cavitation process. Chromium(VI) removal from heavy metal-containing water was examined with the influence of LEM production time, amount of carrier, surfactant concentration, treat ratio (which is the ratio of feed phase to emulsion membrane phase) and type of diluent. The LEM synthesized using hydrodynamic cavitation process showed the possibility of complete removal of Chromium(VI) from the feed phase containing heavy metals, i.e. Chromium(VI). The optimal conditions were observed to be 2 min emulsification time, 1.00% carrier concentration, 3% surfactant concentration and treat ratio of 1:05. Therefore, the application of hydrodynamic cavitation for the production of LEM with excellent stability can be considered as a novel process for the extraction of Chromium(VI) from wastewater.

Design of Intelligent Network to Predicate Phenol Removal from Waste Water by Emulsion Liquid Membrane

This research introduced Intelligent Network's proposed design for predicting efficiency in the removal of phenol from wastewater by liquid membrane emulsion. In the inner phase of W / O emulsions, phenol extraction from an aqueous solution was investigated using emulsion liquid membrane prepared with kerosene as a membrane phase, Span 80 as a surfactant, and NaOH as a stripping agent. Experiments were conducted to investigate the effect of three emulsion composition variables, namely: surfactant concentration, membrane phase to-internal (VM / VI) volume ratio, and removal phase concentration in the internal phase, and two process parameters, feed phase agitation speed at organic acid extraction rates, and emulsion-to-feed volume ratio (VE / VF). More than 98% of phenol can be extracted in less than 5 minutes. This article describes compares the performance of different learning algorithms such as GD, RB, GDM, GDX, CG, and LM to predict the efficiency of phenol removal from wastewater through the liquid emulsion membrane. The proposed neural network consisted of (7, 11, 1) neurons in the input , hidden and output layers respectively feed forward ANN with various types of back propagation training algorithms were developed to model the emulsion liquid membrane removal of phenols. The values predicted for the neural network model are found in close agreement with the results of the batch experiment using MATLAB program with a correlation coefficient ( R2) of 0.999 and Mean Squared Error (MSE) of 0.004.

High internal phase emulsions and their applications in functional material preparation

High internal phase emulsions (HIPEs) are usually defined as a kind of superconcentrated emulsions, in which the minimum internal phase volume fraction reaches to 0.74. Comparing with traditional emulsions, high internal phase emulsions (HIPEs) tend to be highly viscous, solid-like emulsions because of their higher internal phase volume fraction. Thus, focusing on their microstructure, the shape of the oil droplets turned from spheres to irregular polyhedrons separated by a continuous phase film, leading to the deformation of the inner phase droplets. Obviously, the selection of suitable and effective stabilizers based on different stabilization mechanisms is vital for the emulsification process. Up to now, mainly three types of stabilizers based on dissimilar stabilization mechanisms have been successfully developed, including traditional surfactants, solid particles, and low molecular weight or macromolecular gelators. Given that the unique structural features, the wide applicability of HIPEs in pharmaceutical formulations, controlled-release deliverers, cosmetics industries, cold chain logistics and fatty food products has received considerable attentions. Moreover, owing to the characteristics of high viscosity and large interface film area, it is feasible to use high internal phase emulsion as a template to prepare porous functional materials, and the polyhedral structure of the internal droplets endows the final obtained porous material with higher specific surface area, higher porosity and lighter weight. Comparing with the other traditional methods, such as microemulsion method, chemical corrosion method, phase separation method, and so on, the parameters of porous material, including pore distribution, pore capacity and pore density can be easily and precisely controlled by altering the internal and external phase volume fraction, the type of stabilizer and other factors. Overall, the porous materials based on HIPEs template possess many advantages, including low cost, high capacity and excellent reversibility showing huge potential in gas adsorption, separation and enrichment, drug delivery and other practical fields. The present review provides the advanced progresses of preparation of HIPEs and applications in functional materials, with sophisticated porous structures and desirable environmental adaptabilities. Initially, we clearly summarize the synthesizing strategies in regard to both corresponding mechanisms and typical examples developed in recent years, including oil-in-water (O/W) HIPEs, water-in-oil (W/O) HIPEs, oil-in-oil (O/O) HIPEs, high internal phase supercritical fluid emulsions, high internal phase ionic liquid emulsion and high internal phase deep eutectic solvent emulsion. Subsequently, we also clearly discuss in detail the selection of stabilizers including traditional surfactants, solid particles, and low molecular weight or macromolecular gelators, and the influence of various external environmental factors on the stability of high internal phase emulsions (the features of phase, temperature and electrolyte). Meanwhile, we further look forward to their potential applications in functional material preparation, including the functional porous materials, flexible wearable devices and stimulus responsive material. Moreover, the limitations of the existing porous functional materials based on high internal phase emulsion are discussed, including inadequately mechanical performance and unsatisfactory biocompatibility, which will provide significant guidance for synthesizing strategies and practical application in the future. In the end, the current challenges and perspectives on the future development of functional HIPEs materials are also discussed.

Enhancement of Aqueous Solubility and Oral Bioavailability of Bcs Class II Drug by Dry Emulsion

Liquid emulsions have distinct advantages over other dosage forms by improving oral bioavailability as well as by reducing the side effects. On contrary, liquid emulsion exhibit lack of physicochemical stability and compliance issues. To overcome these problems, dry emulsion formulation recommended. Dry emulsions are formulated by spray drying, evaporation and rotary evaporation. The aim of the present investigation is to improve the dissolution and oral bioavailability of poorly water soluble drug Olmesartan medoxomil by preparing dry emulsion. Olmesartan medoxomil is poorly soluble drug used for treatment of high blood pressure, showing absorption window at stomach and upper part of small intestine. Dry emulsion was ready by victimisation purgative during which drug is very soluble, using poloxamer188 as water soluble carrier and aerosil 200 as an adsorbent. The preferred oils were castor oil, olive oil, soybean oil and isopropyl myristate and polymers were PEG400, Eudragit EPO and Poloxamer 188. Dry emulsion was prepared by spray drying. Dry emulsion was evaluated for drug content, percentage moisture content, aqueous solubility, dissolution study and in-vivo bioavailability study. In vitro drug release of dry emulsion was studied by using USP type II paddle dissolution apparatus. The solubility of the drug was increased with surfactant and polymer at 1:1 ratio. Probable mechanisms of improved solubility were characterized by particle size determination, Differential Scanning Calorimetry (DSC), Powder X-ray Diffractometry (PXRD) and Scanning Electron Microscopy (SEM). This study revealed that solid dry emulsion technique could prove promising for improvement of solubility, dissolution rate and oral bioavailability of Olmesartan medoxomil.

Gallium oxide-stabilized oil in liquid metal emulsions.

Gallium based liquid metals (LM) have prospective biomedical, stretchable electronics, soft robotics, and energy storage applications, and are being widely adopted as thermal interface materials. The danger of gallium corroding most metals used in microelectronics requires the cumbersome addition of "barrier" layers or LM break-up into droplets within an inert matrix such as silicone oil. Such LM-in-oil emulsions are stabilized by native oxide on the droplets but have decreased thermal performance. Here we show that mixing of the silicone oil into an LM-air foam yields emulsions with inverted phases. We investigate the stability of these oil-in-LM emulsions through a range of processing times and oil viscosities, and characterize the impact of these parameters on the materials' structure and thermal property relationships. We demonstrate that the emulsion with 40 vol% of 10 cSt silicone oil provides a unique thermal management material with a 10 W m-1 K-1 thermal conductivity and an exterior lubricant thin film that completely prevents corrosion of contacting aluminum.

Multivariate optimization of ultrasound-assisted liquid-liquid microextraction based on two solvents for cadmium preconcentration prior to determination by flame atomic absorption spectrometry.

A method based on ultrasound-assisted emulsification liquid-liquid microextraction (USAEME) for cadmium determination by flame atomic absorption spectrometry (FAAS) was developed in this work. USAEME is based on the use of the mixture of 1,2-dichloroethane and trichloroethylene as an acceptor phase, 2-(2-bromo-5-pyridylazo)-5(diethylamino)phenol (Br-PADAP) as a chelating reagent, and ethanol as a dispersive solvent. The composition of the extraction and dispersive solvents, the volume of the extraction solvent, pH, and the sonication time were optimized using the multivariate strategy. The limits of detection and quantification calculated under optimum conditions were, respectively, 0.39 and 1.33 μg L-1, and the obtained enrichment factor was 21. The accuracy was tested by the analysis of certified reference materials. The method was applied to cadmium determination in bivalve mollusks, water, and urban wastewater from Pontal Bay, Bahia, Brazil. The proposed method is simple, fast, and efficient, and uses small amounts of organic solvents for the determination of cadmium.

Phase-Dependent Surfactant Transport on the Microscale: Interfacial Tension and Droplet Coalescence.

Liquid-liquid emulsion systems are usually stabilized by additives, known as surfactants, which can be observed in various environments and applications such as oily bilgewater, water-entrained diesel fuel, oil production, food processing, cosmetics, and pharmaceuticals. One important factor that stabilizes emulsions is the lowered interfacial tension (IFT) between the fluid phases due to surfactants, inhibiting the coalescence. Many studies have investigated the surfactant transport behavior that leads to corresponding time-dependent lowering of the IFT. For example, the rate of IFT decay depends on the phase in which the surfactant is added (dispersed vs continuous) due in part to differences in the near-surface depletion depth. Other key factors, such as the viscosity ratio between the dispersed and continuous phases and Marangoni stress, will also have an impact on surfactant transport and therefore the coalescence and emulsion stability. In this feature article, the measurement techniques for dynamic IFT are first reviewed due to their importance in characterizing surfactant transport, with a specific focus on macroscale versus microscale techniques. Next, equilibrium isotherm models as well as dynamic diffusion and kinetic equations are discussed to characterize the surfactant and the time scale of the surfactant transport. Furthermore, recent studies are highlighted showing the different IFT decay rates and its long-time equilibrium value depending on the phase into which the surfactant is added, particularly on the microscale. Finally, recent experiments using a hydrodynamic Stokes trap to investigate the impact of interfacial surfactant transport, or "mobility", and the phase containing the surfactant on film drainage and droplet coalescence will be presented.

Magnesium release behavior from W/O/W emulsions incorporated into yogurt: Application to food supplementation

Functional dairy food, yogurt, was produced by incorporating double emulsions encapsulating magnesium chloride in their internal aqueous droplets. For that purpose, W/O/W double emulsions based either on liquid vegetable oil or solid oil ”anhydrous milk fat (AMF),” were prepared, pasteurized, and incorporated into stirred or firm homemade yogurts to produce a fortified yogurt with food intake covers more than 15% of our daily magnesium requirements. Studies of the enriched product carried out over 28 days of storage at 4°C, show that for a high concentration of encapsulated magnesium chloride (0.42 M) in the liquid double emulsions, the magnesium release in yogurt can be low (<6% for sweetened stirred yogurt) and time independent. On the contrary, the use of double emulsions based on AMF makes the food formulation successful in term of taste and magnesium release that does not exceed 9% after 28 days of storage at 4°C. Practical applications W/O/W double emulsions are promoter systems for different applications for example in food for taste masking and/or for food supplementation. The stability of the double emulsions and the release of magnesium in the enriched yogurt were monitored during 28 days of storage at 4°C, we have shown that this formulation is successful with a low and time-independent release. Our findings are generic and may be the object of a real application for functional foods.

Stabilization of vitamin C in emulsions of liquid crystalline structures

Emulsified systems are widely used for topical delivery with the aim of optimizing cutaneous absorption and offering a pleasant sensory. They also may provide a protection of the active molecule against oxidation and/or degradation. The oil phase of o/w emulsions may consist of liquid crystalline structures, especially lamellar structures which are similar to those found in the stratum corneum lipids. In the present work, o/w emulsions containing liquid crystals of mixed cetyl alcohol and Polysorbate 60 were developed for topical delivery of vitamin C, a potent antioxidant with several applications in the cosmetic and pharmaceutical fields. In addition to the well-documented lipid supplementation of the stratum corneum, the liquid crystal emulsions provide a significant chemical stabilization of vitamin C against its degradation. Emulsions were characterized by X-ray diffraction, polarized optical microscopy, and transmission electron microscopy. The stability of vitamin C in the formulations was evaluated upon storage in different conditions of temperature. The emulsions contain a complex colloidal structure, consisting of lamellar liquid crystalline (Lα) and crystalline lamellar gel (Lβ) phases, that provide a very efficient protection of vitamin C against its degradation.

High-speed imaging of ultrasonic emulsification using a water-gallium system

Aiming at elucidating ultrasonic emulsification mechanisms, the interaction between a single or multiple acoustic cavitation bubbles and gallium droplet interface was investigated using an high-speed imaging technique. To our best knowledge, the moment of emulsification and formation of fine droplets during ultrasound irradiation were observed for the first time. It was found that the detachment of fine gallium droplets occurs from the water-gallium interface during collapse of big cavitation bubbles. The results suggest that the maximum size of cavitation bubble before collapsing is of prime importance for emulsification phenomena. Previous numerical simulation revealed that the collapse of big cavitation bubble is followed by generation of high-velocity liquid jet directed toward the water-gallium interface. Such a jet is assumed to be the prime cause of liquid emulsification. The distance between cavitation bubbles and water-gallium interface was found to slightly affect the emulsification onset. The droplet fragmentation conditions are also discussed in terms of the balance between (1) interfacial and kinetic energies and (2) dynamic and Laplace pressure during droplet formation.

Proficiency of nanostructured lipid carriers for the formulation of amphiphilic bile acid oligomers

Biocompatible nanostructured lipid carriers (NLCs) are promising drug delivery vehicles for the formulation of hydrophobic drugs. These nanocarriers comprising liquid lipid inside solid core provide improved drug loading capacity compared to other existing lipid-based nanocarriers such as solid lipid nanoparticles or liquid emulsions. In the present report, we successfully employed D12DAB based NLCs for the formulation of bile acid-derived amphipathic oligomers. The prepared nano-formulation rendered adequate aqueous solubility to these bioactive bile acid oligomers. Hydrodynamic diameter, viscosity, surface tension, conductivity and zeta potential of the prepared NLCs were determined by dynamic light scattering, viscometer, tensiometer, conductivity meter, and zeta analyzer and was found to be in the range of 122−147 nm, 2.07–2.15 mPa.s, 29.7–30.2 mN/m, 540−550 mS/m, and 15.7−16 mV, respectively. In addition, Field Emission Scanning Electron Microscopy and Transmission Electron Microscopy analysis were performed to understand the external morphology and internal structure of synthesized NLCs. The applications of the synthesized NLCs to encapsulate dapsone and its release kinetics were studied in detail. The results conferred the formation of bile acid-enriched stable NLCs which could be a promising system to formulate and/or deliver several combinations of antibiotics or other bioactive agents to treat undesired physiological conditions.

Impact of cocoa fibers on the stability and rheological properties of chocolate ganaches

This work investigates the structure and behavior of model oil-in-water chocolate ganaches by comparing two systems differing in the nature of the dispersed (fat) phase: cocoa butter and cocoa mass (mix of cocoa butter and fibers). Significant differences regarding the textural properties and stability were evidenced. Concentrated liquid emulsions made with cocoa butter had a thick and homogeneous macroscopic aspect. Upon cooling, fat crystallization produced partial coalescence and the emulsions became solid. With molten cocoa mass, a homogeneous aspect was observed until 50 g/100 g of dispersed phase and a grainy texture was obtained at larger fractions. This textural transition was interpreted as being due to a jamming transition. Both conventional and fluorescence microscopy revealed that cocoa fibers were transferred from the fat phase to the aqueous phase and were partially anchored to the interfaces. Upon cooling, cocoa fibers acted as a physical barrier that limited the extent of partial coalescence.

The experimental and numerical study of the vertical gas movement in the cylindrical channel

The detailed experimental and theoretical studies of the vertical gas movement through a layer of liquid (water, molten tin) placed in a cylindrical channel (10 cm diameter) were performed. It was shown that during the gas passage through a single opening (the diameter of 8 mm) its movement at a small flow takes place as single bubbles, whose diameter becomes greater as they move towards the free surface of the liquid. Increase in the diameter at identical gas and liquid temperatures is explained by the decreasing liquid pressure in the upstream direction. If the gas temperature is lower than the liquid temperature, the diameter of bubbles increases also due to gas heating, thus resulting in the increase of its pressure in the bubble. As the gas flow increases, the number of bubbles which then merge into the uniform mass in the upper part of the channel without reducing their diameter, becomes greater. When passing the gas though the diaphragm with a high number of openings (80 openings of 1 mm in diameter), the amount of bubbles becomes higher, however their diameter in the upper part of the channel practically does not increase. When using multiple strainer diaphragms arranged at small distances from each other along the channel height, the diameters of bubbles become considerably reduced, which is connected with their periodic fragmentation when passing through each subsequent strainer. Furthermore, the bubbles get the smallest diameter when they pass through the last strainer, after which the liquid and the gas make a uniform gas and liquid emulsion in the form of a mist. The analysis of the results of air passage thought the molten tin (at a temperature of 300°C) allows concluding on considerable increase in the bubble diameter as compared to the experiments with water, which is explained by gas heating in the bubbles due to a sufficiently high temperature of tin and, as a result, the increase of pressure in them. Experimental studies applicable to small-diameter cylindrical channel (2 cm) were also performed. Their analysis allows concluding about a considerable divergence of the obtained results as compared to the greater diameter channel (10 cm) at the same gas flow. For the small-diameter channel, numerical calculations were also performed (e.g. tin) in a vertical cylindrical channel (reactor) [5 – 8]. The amount of hydrogen obtained at the reactor outlet depends on the intensity of methane heating to the pyrolysis temperature. It is known that methane passes through the molten tin in the form of bubbles, whose diameter increases as they move towards the upper part of the reactor, which is connected with the reduction of upstream pressure of liquid metal as well as the increase of gas pressure in bubbles resulted from its heating. The increase in the bubble diameter makes it heating to the pyrolysis temperature difficult as a result of low heat conductivity of methane. In this regard, measures should be taken to decrease their diameter.

Determination of Fenvalerate reside in raisin via vortex-assisted surfactant-enhanced emulsification liquid–liquid microextraction (VSLLME) method by using HPLC system

In this project, ultra-trace amounts of Fenvalerate residue in raisin, were determined via vortex-assisted surfactant-enhanced emulsification liquid–liquid micro extraction (VSLLME) method and by using HPLC-PDA detector at 225nm. In the VSLLME method, the extraction solvent is dispersed into the aqueous samples by assistance of vortex agitator. Meanwhile, the addition of a surfactant, which was used as an emulsifier, could enhance the rate of the mass-transfer from aqueous samples to the extraction solvent. The main parameters relevant to this method were investigated and the optimum conditions were established: 20 µL chlorobenzene was used as extraction solvent, 0.9 mmol.L-1CTAB was selected as the surfactant, the extraction time was fixed at 60s, 2% sodium chloride was added and the extraction process was performed under the room temperature. Under the optimum conditions, limit of detection (LOD) was 0.3 ng mL-1. The relative standard deviation (RSD, n=6) was 2.87%. The linearity was obtained by five points in the concentration range of 0.3 to 100.0 ng mL-1. Correlation coefficients (R2) was 0.9997, and the enrichment factor (EF) was 114. Finally, the proposed method has been successfully applied for determination of Fenvalerate in real samples. The recoveries of the target analyte in raisins samples were between 84.13% and 92.12%.

Antifungal efficacy of liquid poloxamer 407-based emulsions loaded with sertaconazole nitrate.

Drug delivery into the human nail plate for the treatment of onychomycosis is difficult due to limited permeability of the nail plate. Semisolid poloxamer 407-based formulations have recently shown promising results for drug delivery into and through the nail plate. In this study, liquid poloxamer 407-based emulsions loaded with sertaconazole nitrate have been developed and the permeation behavior was determined in vitro using modified Franz diffusion cells. The antifungal efficacy was evaluated in an infected nail plate model, where the growth inhibition of Trichophyton rubrum was observed. Bovine hoof plates and keratin films made from human hair were used as models for the human nail plate. In both cases, formulations with low viscosity and high water content showed best results despite a lower solubility of sertaconazole nitrate, suggesting that the composition of the vehicle plays a major role in permeation through the membrane. In addition, an API content close to saturation solubility had a positive effect on permeation.