Continuous Encapsulation of Vitamin E Using Polycaprolactone and Tween 20 in a Micro-Channel

Author(s):  
Amaraporn Kaewchada ◽  
Rotsaman Chongcharoen ◽  
Preuk Tangpromphan ◽  
Khwanchanok Nakkong ◽  
Attasak Jaree

Encapsulation of vitamin E is the preservation of the biological activities of vitamin E for various applications. In the first part of this research, factors affecting the batch encapsulation of vitamin E, including PCL concentration, the concentration of Tween 20, and the volumetric ratio of aqueous phase to organic phase were experimentally investigated. The Box-Behnken experimental design and response surface methodology were implemented to determine the optimal operating conditions of the batch encapsulation. At the optimal conditions, the percentage of vitamin E encapsulation (%EC) was 98.69%, using the PCL concentration, the Tween 20 concentration, and the volumetric ratio of aqueous phase to organic phase of 3.6 g/L, 0.6 g/L, and 0.9 mL: 1 mL, respectively. The second part is to enhance the productivity by applying the optimized formulation of vitamin E encapsulation in a continuous process using a micro-channel encapsulator. The effect of residence time was investigated. At the residence time of 1 s, the percentage of vitamin E encapsulation of 97.28% and the productivity of 153.61 mg/(mL∙min) were achieved.

Author(s):  
Renqiang Xiong ◽  
Mo Bai ◽  
Yun Whan Na ◽  
Jacob N. Chung

Micro-bubble generation in a rectangular co-flowing micro-channel with a cross-section area of 1.69 × 0.07mm2 was experimentally and numerically investigated. Air and water were used to be the gas and liquid, respectively. Mixtures of water-glycerol and water-Tween 20 were also used to obtain the effect of viscosity and surface tension. The experimental data shows that the break-up process is periodic under certain operating conditions. The bubble dynamics are also examined using a computational fluid dynamics (CFD) simulation. The CFD model successfully simulates the flow behavior and provides a closer examination of the bubble shape. The bubble length L to the channel width w is a function of the ratio of gas flow rate Qg and liquid flow rate Ql which is the same as that used in the T-junction. Bubble frequency f is found to be related with channel width w, channel depth h, and QlQg/(Qg + Ql · π/4). The formulation shows good agreement with the experimental data at the low frequency region. Different bubble shapes can be obtained at different liquid viscosities and surface tensions. The dimensionless bubble length L/w can still be predicted by a modified equation which uses the real bubble width wb or an equivalent bubble length Le.


1979 ◽  
Vol 44 (12) ◽  
pp. 3656-3664
Author(s):  
Oldřich Navrátil ◽  
Jiří Smola ◽  
Rostislav Kolouch

Extraction of hafnium(IV) was studied from solutions of mixtures of perchloric and nitric acids and of perchloric and hydrochloric acids for constant ionic strength, I = 2, 4, 6, or 8, and for cHf 4 . 10-4 mol l-1. The organic phase was constituted by solutions of some acidic or neutral organophosphorus reagents or of 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, or N-benzoyl-N-phenylhydroxylamine in benzene, chloroform, or n-octane. A pronounced synergic extraction of hafnium proceeds only on applying organophosphorus reagents from an aqueous phase whose acidity is not lower than 3M-(HClO4 + HNO3) or 5M-(HClO4 + HCl). The synergic effect was not affected markedly by a variation of the initial concentration of hafnium in the range 1 . 10-8 -4 .10-4 mol l-1, it lowered with increasing initial concentration of the organophosphorus reagent and decreasing concentration of the H+ ions. It is suggested that the hafnium passes into the organic phase in the form of mixed complexes, the salting-out effect of perchloric acid playing an appreciable part.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 942
Author(s):  
Emilie Isidore ◽  
Hamza Karim ◽  
Irina Ioannou

Cannabis sativa L. is a controversial crop due to its high tetrahydrocannabinol content varieties; however, the hemp varieties get an increased interest. This paper describes (i) the main categories of phenolic compounds (flavonoids, stilbenoids and lignans) and terpenes (monoterpenes and sesquiterpenes) from C. sativa by-products and their biological activities and (ii) the main extraction techniques for their recovery. It includes not only common techniques such as conventional solvent extraction, and hydrodistillation, but also intensification and emerging techniques such as ultrasound-assisted extraction or supercritical CO2 extraction. The effect of the operating conditions on the yield and composition of these categories of phenolic compounds and terpenes was discussed. A thorough investigation of innovative extraction techniques is indeed crucial for the extraction of phenolic compounds and terpenes from cannabis toward a sustainable industrial valorization of the whole plant.


Author(s):  
Nikolaj Dobrzinskij ◽  
Algimantas Fedaravicius ◽  
Kestutis Pilkauskas ◽  
Egidijus Slizys

Relevance of the article is based on participation of armed forces in various operations and exercises, where reliability of machinery is one of the most important factors. Transportation of soldiers as well as completion of variety of tasks is ensured by properly functioning technical equipment. Reliability of military vehicles – armoured SISU E13TP Finnish built and HMMWV M1025 USA built were selected as the object of the article. Impact of climatic conditions on reliability of the vehicles exploited in southwestern part of the Atlantic continental forest area is researched by a case study of the vehicles exploitation under conditions of the climate of Lithuania. Reliability of military vehicles depends on a number of factors such as properties of the vehicles and external conditions of their operation. Their systems and mechanisms are influenced by a number of factors that cause different failures. Climatic conditions represent one of the factors of operating load which is directly dependent on the climate zone. Therefore, assessment of the reliability is started with the analysis of climatic factors affecting operating conditions of the vehicles. Relationship between the impact of climatic factors and failure flow of the vehicles is presented and discussed.


Author(s):  
Noman Yousuf ◽  
Timothy Anderson ◽  
Roy Nates

Abstract Despite being identified nearly a century ago, the diffusion absorption refrigeration (DAR) cycle has received relatively little attention. One of the strongest attractions of the DAR cycle lies in the fact that it is thermally driven and does not require high value work. This makes it a prime candidate for harnessing low grade heat from solar collectors, or the waste heat from stationary generators, to produce cooling. However, to realize the benefits of the DAR cycle, there is a need to develop an improved understanding of how design parameters influence its performance. In this vein, this work developed a new parametric model that can be used to examine the performance of the DAR cycle for a range of operating conditions. The results showed that the cycle's performance was particularly sensitive to several factors: the rate of heat added and the temperature of the generator, the effectiveness of the gas and solution heat exchangers, the mass flowrate of the refrigerant and the type of the working fluid. It was shown that can deliver good performance at low generator temperatures if the refrigerant mass fraction in the strong solution is made as high as possible. Moreover, it was shown that a H2O-LiBr working pair could be useful for achieving cooling at low generator temperatures.


2015 ◽  
Vol 74 (7) ◽  
Author(s):  
Mohd Azizi Che Yunus ◽  
Salman Zhari ◽  
Saharudin Haron ◽  
Nur Husnina Arsad ◽  
Zuhaili Idham ◽  
...  

Pithecellobium Jiringan (P. Jiringan) is traditionally known as natural herb consists of several medicinal compounds (vitamin E). Supercritical carbon dioxide extraction (SC-CO2) has been proven as potential method to extract interest compound from herbs. By altering pressure and temperature, the specific compound can be extracted. In this study, the SC-CO2 operating conditions are pressure (20.68 MPa to 55.16 MPa) and temperature (40°C to 80°C) in one hour extraction regime was used to extract vitamin E from P. jiringan. The quantification of vitamin E was analysed with Gas Chromatography Time of Flight Mass Spectrometry (GC-TOF-MS). The responses are overall oil yield and vitamin E yield. The overall oil yield was obtained at the highest condition of 55.16 MPa and 80°C with asymptotic yield of 8.06%. In contrast, the highest amount of vitamin E obtained is 0.0458mg/g sample (80.14 ppm) at the lowest extraction condition of 20.68 MPa and 40ᵒC.


Author(s):  
Xiaowei Fan ◽  
Fang Wang ◽  
Huifan Zheng ◽  
Xianping Zhang ◽  
Di Xu

The refrigerant mixtures provide an important direction in selecting new environment-friendly alternative to match the desirable properties with the existing halogenated refrigerants or future use in the new devices, in which, HFCs refrigerants with zero ODP combined with HCs refrigerants with zero ODP and lower GWP are of important value in the fields of application. In the present work, research on HFC125/HC290 (25/75 by mass) binary refrigerant mixture used in heat pumps was carried out, and parameters, factors affecting the performance were investigated, and compared with that of HCFC22 under the same operating conditions. It has been found that the new mixture can improve the actual COP by 2 to 13% and hence it can reduce the energy consumption by 20 to 31.5%. The overall performance has proved that the new refrigerant mixture could be a promising substitute for HCFC22.


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