Study of process intensification Higee technology applied to the absorption

Treballs Finals de Grau d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2015-2016, Tutor: Jose Maria Gutiérrez GonzálezHigee technology or High-gravity Technology has been widely studied for the intensification of industrial processes such as absorption, desorption, distillation, extraction, among others, in order to find and improve the benefits compared to conventional methods. According to Documents about Best Available Techniques (BREFs), Higee technology is emerging as an alternative to the methods used so far. This work studies Higee technology improvements applied to the absorption process compared to conventional packed columns. The absorption is mainly used to remove pollutant components of a gas stream to avoid leaks outside and/or to recover some component that the stream could contain for production purposes. To achieve the goals of this project, a bibliographic search of Higee technology, studied by different authors, has been performed. In this research, the focus is on the modifications made in recent years in order to show the advantages of this technology compared to the conventional one. After this research, the design of a conventional absorption column and Rotating Packed Bed have been studied in order to make a comparison among the design results and a comparison of these with those obtained experimentally by the different authors. From these studies the main conclusion is that the use of Higee technology get a huge reduction in the volume of the device and it is also possible to use smaller amounts of absorbent liquid. However, Higee technology presents some disadvantages over conventional technology because it is necessary that the absorbent liquid be subjected to a centrifugal force, so this will require greater energy. All these changes make the design more complex and the device suffers a faster wear due to continuous movement and, consequently, it increases the economic cost. Thus, based on studies performed so far, replacing the conventional absorption column for Higee technology is not recommendable. However, it should be further investigated because it has potential to get better results in comparison with conventional processes, either applied in the process studied in this work or applied to another types of processes

Antidiabetic potential of mucilage fraction extracted from Astragalus gyzensis seeds

The objective of the current work is to extract a new mucilage fraction from Astragalus gyzensis Bunge. seeds, which are collected from the El-Oued province (septentrional Algerian Sahara) and evaluated for their antidiabetic potential. The mucilage fraction is obtained using hot water extraction followed by alcoholic precipitation of polysaccharides by cold ethanol (96%). The primary investigation was performed by describing the main structural features of the extract through colorimetric assays, Fourier-transform infrared spectroscopy and thin-layer chromatography analysis using two systems. Biological activity was also monitored by antidiabetic activity by testing the inhibition of α-amylase and α-glucosidase enzymes in vitro. The extraction yield was 20.69%. The chemical composition mainly consisted of 78.60±0.29% carbohydrates, among them 63.92±0.67% neutral sugar, 15.78±0.76% uronic acid, 8.08±0.04% proteins and 2.57±0.05% phenolic compounds. The results obtained by thin-layer chromatography analysis showed the dominance of mannose and galactose. Fourier-transform infrared spectrum showed characteristic bands expected galactomannans. The investigations highlighted the antihyperglycemic effect in a dose-dependent manner by the inhibition of the α-amylase enzyme (IC50=0.8±0.005 mg/mL). These factors make it suitable for the industrial application of dietary supplement fiber made for diabetic individuals. DOI: http://dx.doi.org/10.5281/zenodo.761853

Curcumin gum Arabic nanoparticles demonstrate potent antioxidant and cytotoxic properties in human cancer cells

The main purpose of the study was to enhance the stability and therapeutic effects of Curcumin (Cur) through nanoformulation with gum Arabic (GA) as a coating agent through an efficient synthetic approach. The antioxidant properties of the developed nanoparticles (Cur/GANPs) were assessed through several in vitro assays, such as β-carotene bleaching activity, DPPH, and nitric oxide scavenging activities in addition to evaluating its inhibitory activity on angiotensin-converting enzyme (ACE). The cytotoxicity of Cur/GANPs was evaluated in vitro using different types of human cancer cells including breast cancer (MCF7, MDA-MB231), liver cancer (HepG2), and colon cancer (HT29) cells. The prepared particles displayed an elliptical shape with a size ranging between 20–260 nm and a potential difference of –15 mV. The Cur/GANPs exhibited significant antioxidant activity compared to free curcumin when using concentrations between 31.5 and 500 µg/mL. The Cur/GANPs also had inhibited the growth of all cancer cell lines in a proportional trend with concentrations used. Hence, the encapsulation with gum Arabic has augmented the antioxidant and anti-neoplastic effects of Curcumin. Therefore, Cur/GANPs may have effective therapeutic properties in diseases attributed to oxidative stress like cancer and hypertension

Etude de l'effet du recuit à haute température sur les propriétés des couches minces de ZnO déposées par spray pyrolyse pour application photovoltaïque

93 p. : ill. ; 30 cmL’oxyde de Zinc est parmi les oxydes transparents et conducteurs les plus prometteurs dans le domaine du photovoltaïque. En effet, il joue le rôle de fenêtre optique permettant de capter plus de photons. Le présent travail consiste à étudier et comprendre le comportement du ZnO déposé par spray pyrolyse avec le recuit de frittage à hautes températures de la métallisation par sérigraphie. La métallisation par sérigraphie est la technique de fabrication par excellence de cellules solaires à l’échelle industrielle. On se focalise surtout sur les propriétés structurelles et chimiques. Dans le but d’augmentation du rendement de conversion des cellules solaires à base de silicium, une couche mince d’un oxyde transparent et conducteur TCO est déposée sur une jonction np. Cette couche mince ZnO doit subir le recuit de frittage de la métallisation par sérigraphie de 650°C à 900°C. Pour l’étude des propriétés structurelles et chimiques, des couches minces d’oxydes de zinc ont été déposées sur des substrats de quartz afin de supporter les hautes températures de la métallisation par sérigraphie. Il a été constaté une que les paramètres structurelles des couches déposées concorde avec la théorie ainsi que la composition chimique des couches n’est pas influencer par l’augmentation de la température de recuit ce que ne va pas nuire au propriétés optiques qui est le but de notre travai

Electrochemical synthesis of ZnO thin film and nanowire for piezoelectric applications

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Non-enzymatic electrochemical detection of glucose with and without the presence of insulin using rGO/ZnO

International audienceIn the present work, the combination of the electrophoretic deposition of ZnO nanostructures with size not exceeding 50 nm, and the reduced graphene oxide (rGO) on gold electrodes was performed to study the non-enzymatic electrochemical detection of glucose. The effect of insulin insertion on glucose detection and regulation was studied and the electrochemical responses were compared with and without this molecule. The results showed that the GO/insulin/ZnO electrode is much more sensitive for the glucose detection, in addition to its ability to drop the insulin protein hormone under a negative voltage. That bears interest as dual function sensor for detection and regulation of glucose

A sulfated exopolysaccharide derived from Chlorella sp. exhibiting in vitro anti-α-d-Glucosidase activity

International audienceThere is a great scientific curiosity to discover all environments sheltering microalgae, especially those with exceptional characteristics from coldest to hottest ones, the purpose remains to explore the potential of the native microalgae flora and the research for new bioactive compounds. This study aimed to isolate a polysaccharide-producing microalga from an extreme ecosystem and to evaluate its capacity to inhibit the α- d - glucosidase enzyme. Chlorella strain is isolated from hypersaline Lake in the Algerian desert. The exopolysaccharide extraction was performed by the concentration of free-cell supernatant in a rotary evaporator. The infrared analysis showed a characteristic footprint of carbohydrates with particular functional groups, such as sulfate. Gas chromatography–mass spectrometry has revealed a hetero-exopolysaccharide composed of galactose 35.75%, glucose 21.13%, xylose 16.81%, fructose 6.96%, arabinose 5.10%, and glucuronic acid 2.68%. The evaluation of the anti-hyperglycemic activity demonstrated a significant α- d -glucosidase inhibition of 80.94 ± 0.01% at 10 mg mL −1 with IC 50 equal to 4.31 ± 0.20 mg mL −1 . This study opens a vast prospect to use exopolysaccharides as natural nutraceutical or food additive

Enhancement of Candida albicans phagocytosis and inhibitory potency of Alternative Complement Pathway by an arabinoxylan extracted from Plantago ciliata Desf. Seeds and its oligosaccharides

International audienceLeveraging bioactive compounds with immunomodulatory effects to boost immune functions represents a promising strategy for therapeutic intervention. The main objective of this work was to investigate the influence of the partial acid hydrolysis of an arabinoxylan extracted from Plantago ciliata Desf. seeds into oligosaccharides on its immunomodulatory effect. The resulting oligosaccharides and their polymer were evaluated for their potential to improve the phagocytic capacity (PC) and the phagocytic activity (PA) of polymorphonuclear neutrophils (PMNs) through the uptake of Candida albicans and to moderate alternative complement pathway (ACP) activation. As a result, the arabinoxylan derived from P. ciliata seeds (AXPCs) and its oligosaccharides (AXOPCs) significantly enhanced the PC of PMN cells, with EC50 values of 0.14±0.23 and 0.12±0.10 mg/mL, respectively. Zymosan used as a reference exhibited the highest PC with an EC50 0.07±0.08 mg/mL. However, for PA, zymosan still demonstrated the highest activity with an EC50 of 0.22±0.46 mg/mL compared to 0.33±1.36 and 0.30±0.74 mg/mL for AXPCs and AXOPCs, respectively. Moreover, AXPCs and AXOPCs were tested as moderator inhibitors of the complement system, showing maximum inhibition percentages of 40.11±8.38% and 50.57±10.45% at 1 mg/mL, with IC50 values of 1.49±0.40 and 1.02±0.20 mg/mL, respectively, compared to 61.52±7.17% and 70.89±5.78% for heparin used as a reference. These results suggest that AXPCs and AXOPCs can serve as relevant therapeutic immunomodulatory factors

Inhibitory effect of arabinoxylan oligosaccharides from Plantago ciliata Desf. seeds on α-amylase and α-d-glucosidase and the inhibition kinetics

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