scholarly journals Empirical Correlation of Emulsion Size Prediction for Zinc Extraction Using Flat Blade Impeller System in Emulsion Liquid Membrane Process

2021 ◽  
Vol 17 (6) ◽  
pp. 742-751
Author(s):  
Sazmin Sufi Suliman ◽  
Norasikin Othman ◽  
Norul Fatiha Mohamed Noah ◽  
Norela Jusoh ◽  
Raja Norimie Raja Sulaiman

In this study, determination of droplets in the presence of blended mixture of surfactants (Span 80 and Tween 80) and nanoparticles, iron (III) oxide (Fe2O3) were investigated using a single stage mixer-settler extractor with 4-pitched flat blade impeller on one shaft employment. Additionally, the influence of Fe2O3 and blended surfactant mixture of Span 80 and Tween 80 on the dispersion of emulsion in terms of Sauter diameter (D32) measurement was compared with new correlations. Results indicate that the presence of Fe2O3 in the blended mixture of surfactant simultaneously decreased in D32 by 79 % and the stability of the emulsion system was enhanced. Overall, empirical correlation for droplet size at different conditions are obtained, and the modified correlation for D32 is presented. The correlation found is D32/DI =0.02265(3.419Φi−1)We-0.6. The calculated average absolute relative deviation (%AARD) is 2.69 %, thus indicating a good accuracy and acceptability between the presented correlation and experimental data.

Buletin Palma ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 31
Author(s):  
Linda Trivana ◽  
Nugraha E. Suyatma ◽  
Dase Hunaefi ◽  
S. Joni Munarso

<p>Virgin coconut oil (VCO) is high quality coconut oil and categorized as the healthiest oil and functional foods. Based on these benefits, the development of a VCO in emulsion product might increase the human consumption of coconut oil because consumers dislike the only taste of pure VCO. The aim of this study was to develop the water compatible form of VCO through nano-emulsification. The effect of different types and amounts of surfactants (Tween 80 and Span 80) on the physio-chemical characteristic of emulsion containing VCO was investigated. VCO based emulsions were prepared with the aid of Ultra-Turrax homogenizer. Emulsions were developed by adding and mixing VCO with surfactants. The ratio of Tween 80 and Span 80 used were 0:10, 2.5:7.5, 5:5, 7.5:2.5, and 10:0. The droplet size of nanoemulsions consisting of Tween 80:Span 80 (0:10, 2.5:7.5, 5:5, 7.5:2.5, and 10:0) were 1.343, 0.606, 0.829, 1.439, and 2.506µm, respectively. Based on the TEM analysis and polydispersity index (PDI) &gt;0.5 showed the oil droplets are in not uniform shape, indicating a unstable emulsion. VCO emulsion with ratio Tween 80:Span 80 (0:10) obtained a homogeneous emulsion (stable) compare than that of others and w/o type emulsion. The stability of emulsion is evaluated by turbidity measurement using UV-VIS spectrophotometer with wavelength 502 nm. A combination of  treatments (ambient condition, thermal treatmeant (40°C)), and centrifuge) of VCO emulsion has resulted on thermal treat, the turbidity measured from the emulsion was higher than the other emulsion, reflecting the presence of the smaller droplets in this emulsion.</p>


2020 ◽  
Vol 16 (2) ◽  
pp. 130-143
Author(s):  
Yandi Syukri ◽  
Septiani Eka Cahyani ◽  
Bambang Hernawan Nugroho

Background: Mefenamic acid is a non-steroidal anti-inflammatory drug (NSAID) with low solubility in water. Self-Nanoemulsifying Drug Delivery Systems (SNEDDS) play a role to improve the solubility and bioavailability of mefenamic acid. Objective: This study aimed to determine the stability of mefenamic acid in SNEDDS formulation through various stability studies. Methods: The stability studies conducted consisted of centrifugation test, heating-cooling cycle test, freezethaw cycle test, robustness to dilution, accelerated storage test, and determination of drug content. Results: The centrifugation test, heating-cooling cycle test, and freeze-thaw cycle test showed no phase separation in the samples. The robustness to dilution and accelerated storage test resulted in 2 formulas of mefenamic acid loaded SNEDDS having good stability with 10% oleic acid, 80% tween 80, 10% PEG 400 and 10% oleic acid, 70% tween 80, 20% PEG 400. The determination of drug content in both of these formulations showed 98.20 ± 0.04% and 90.98 ± 0.06%. Conclusion: The SNEDDS formulation of mefenamic acid in this study had good stability. Keywords: SNEDDS, mefenamic acid, stability study, oleic acid


Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2105
Author(s):  
Giovana Colucci ◽  
Arantzazu Santamaria-Echart ◽  
Samara C. Silva ◽  
Isabel P. M. Fernandes ◽  
Caroline C. Sipoli ◽  
...  

Water-in-oil (W/O) emulsions have high potential for several industrial areas as delivery systems of hydrophilic compounds. In general, they are less studied than oil-in-water (O/W) systems, namely in what concerns the so-called fluid systems, partly due to problems of instability. In this context, this work aimed to produce stable W/O emulsions from a natural oil, sweet almond oil, to be further tested as vehicles of natural hydrophilic extracts, here exemplified with an aqueous cinnamon extract. Firstly, a base W/O emulsion using a high-water content (40/60, v/v) was developed by testing different mixtures of emulsifiers, namely Tween 80 combined with Span 80 or Span 85 at different contents. Among the tested systems, the one using a 54/46 (v/v) Span 80/Tween 80 mixture, and subjected to 12 high-pressure homogenizer (HPH) cycles, revealed to be stable up to 6 months, being chosen for the subsequent functionalization tests with cinnamon extract (1.25–5%; w/v; water-basis). The presence of cinnamon extract leaded to changes in the microstructure as well as in the stability. The antimicrobial and antioxidant analysis were evidenced, and a sustained behavior compatible with an extract distribution within the two phases, oil and water, in particular for the higher extract concentration, was observed.


2015 ◽  
Vol 1113 ◽  
pp. 481-485
Author(s):  
Siti Balqis Mohd Najib ◽  
Khairul Sozana Nor Kamaruddin

The capture of carbon dioxide (CO2) by aqueous alkanolamine is the most cost effective technology available today. However, some problem such as amine losses, corrosion and low absorption rate arise when aqueous alkanolamines is used as an absorbent. To overcome these problems, liquid emulsion was introduced as an alternative for CO2 removal. However, the main concern of using liquid emulsion is the stability of the emulsion. In this study, a formulation containing mixture of blended alkanolamine was used. Methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) were used as extractants and were mixed with sodium hydroxide (NaOH) solution to form the aqueous phase. Meanwhile, the organic phase consists of kerosene and Span 80. The emulsion was prepared by homogenizing both phases at speed of 10 000 rpm for five minutes. The stability of the MDEA-AMP emulsion was determined and the CO2 absorption by the emulsion was measured. This study showed that using 8 mL MDEA and 4mL AMP, the stability of the emulsion was 74.00% and 48.05% of CO2 was removed.


2017 ◽  
Vol 68 (10) ◽  
pp. 2320-2324
Author(s):  
Mariana Mateescu ◽  
Sanda Maria Doncea ◽  
Irina Chican ◽  
Cristina Lavinia Nistor ◽  
Ioneta Codrina Bujanca

The aim of this work is the synthesis of calcium carbonate (CaCO3) nano and microparticles and their application as biomaterials (vehicles) for the sustained release of doxycycline. CaCO3 micro particles were synthesized by water-in oil (W/O) emulsion method using emulsion liquid membranes with bis (2-ethylhexyl) phosphate (D2EHPA) as carrier, Span 80 as surfactant, and toluene and kerosene as organic solvents. The aqueous phases contained 1 M CaCl2, and 1 M Na2CO3, respectively. The Dynamic Light Scattering (DLS) data showed CaCO3 particles with sizes ranging from around 100 nm to 3500 nm. The CaCO3 particles with the average diameters around 600 nm attained an adsorbtion of doxycycline of maximum 97.9%, and a slow and steady release with a cumulative value of approximative 50% after ten days.


Author(s):  
Sunny Katyara ◽  
Lukasz Staszewski ◽  
Faheem Akhtar Chachar

Background: Since the distribution networks are passive until Distributed Generation (DG) is not being installed into them, the stability issues occur in the distribution system after the integration of DG. Methods: In order to assure the simplicity during the calculations, many approximations have been proposed for finding the system’s parameters i.e. Voltage, active and reactive powers and load angle, more efficiently and accurately. This research presents an algorithm for finding the Norton’s equivalent model of distribution system with DG, considering from receiving end. Norton’s model of distribution system can be determined either from its complete configuration or through an algorithm using system’s voltage and current profiles. The algorithm involves the determination of derivative of apparent power against the current (dS/dIL) of the system. Results: This work also verifies the accuracy of proposed algorithm according to the relative variations in the phase angle of system’s impedance. This research also considers the varying states of distribution system due to switching in and out of DG and therefore Norton’s model needs to be updated accordingly. Conclusion: The efficacy of the proposed algorithm is verified through MATLAB simulation results under two scenarios, (i) normal condition and (ii) faulty condition. During normal condition, the stability factor near to 1 and change in dS/dIL was near to 0 while during fault condition, the stability factor was higher than 1 and the value of dS/dIL was away from 0.


2016 ◽  
Vol 5 (10) ◽  
pp. 4920
Author(s):  
Amar M. Ali ◽  
Hussain. J. Mohammed*

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood. 


Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 525 ◽  
Author(s):  
Mehdi Keshavarz-Ghorabaee ◽  
Maghsoud Amiri ◽  
Edmundas Kazimieras Zavadskas ◽  
Zenonas Turskis ◽  
Jurgita Antucheviciene

The weights of criteria in multi-criteria decision-making (MCDM) problems are essential elements that can significantly affect the results. Accordingly, researchers developed and presented several methods to determine criteria weights. Weighting methods could be objective, subjective, and integrated. This study introduces a new method, called MEREC (MEthod based on the Removal Effects of Criteria), to determine criteria’ objective weights. This method uses a novel idea for weighting criteria. After systematically introducing the method, we present some computational analyses to confirm the efficiency of the MEREC. Firstly, an illustrative example demonstrates the procedure of the MEREC for calculation of the weights of criteria. Secondly, a comparative analysis is presented through an example for validation of the introduced method’s results. Additionally, we perform a simulation-based analysis to verify the reliability of MEREC and the stability of its results. The data of the MCDM problems generated for making this analysis follow a prevalent symmetric distribution (normal distribution). We compare the results of the MEREC with some other objective weighting methods in this analysis, and the analysis of means (ANOM) for variances shows the stability of its results. The conducted analyses demonstrate that the MEREC is efficient to determine objective weights of criteria.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1976
Author(s):  
Tomasz Garbowski ◽  
Tomasz Gajewski

Knowing the material properties of individual layers of the corrugated plate structures and the geometry of its cross-section, the effective material parameters of the equivalent plate can be calculated. This can be problematic, especially if the transverse shear stiffness is also necessary for the correct description of the equivalent plate performance. In this work, the method proposed by Biancolini is extended to include the possibility of determining, apart from the tensile and flexural stiffnesses, also the transverse shear stiffness of the homogenized corrugated board. The method is based on the strain energy equivalence between the full numerical 3D model of the corrugated board and its Reissner-Mindlin flat plate representation. Shell finite elements were used in this study to accurately reflect the geometry of the corrugated board. In the method presented here, the finite element method is only used to compose the initial global stiffness matrix, which is then condensed and directly used in the homogenization procedure. The stability of the proposed method was tested for different variants of the selected representative volume elements. The obtained results are consistent with other technique already presented in the literature.


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