Mobile communication systems to control UAVs: Measurements of QoS parameters

This paper proposes to identify a propagation model that considers the unmanned aerial vehicles (UAVs) unique characteristics, contemplating two actual wireless technologies, UMTS and LTE, which are theoretically capable of supporting a real-time video service admitting more than one quality index according to the RF conditions. Several measurements were made in a specific outdoor rural scenario in order to understand if the current network infrastructure is prepared to support this type of service using these vehicles, by simulating a real case scenario and considering critical locations where the loss of Quality of Service (QoS) can be significant due to the hole phenomenon that occurs over the antennas/base stations, raising the probability to occur handover.info:eu-repo/semantics/acceptedVersio

Avaliação de metodologia para análise de íons por cromatografia iônica em água de nascentes.

Editores técnicos: Marcílio José Thomazini, Elenice Fritzsons, Patrícia Raquel Silva, Guilherme Schnell e Schuhli, Denise Jeton Cardoso, Luziane Franciscon. EVINCI. Resumos

Cation effect on the (PEG 8000 + sodium sulfate) and (PEG 8000 + magnesium sulfate) aqueous two-phase system: Relative hydrophobicity of the equilibrium phases

The partitioning of four dinitrophenylated (DNP-) amino acids in aqueous two-phase systems of polyethylene glycol (PEG)-8000sodium sulfate and polyethylene glycol (PEG)-8000magnesium sulfate in five different tie-lines was experimentally determined at 298.15 K. The Gibbs free energy of transfer of a methylene group between the two phases was calculated from the measured partition coefficients. This characterizes the relative hydrophobicity of the equilibrium phases. Values of G(CH2) were in range from (-0.674 to -1.012) kJ·mol-1. A comparison of both systems was carried out. The results show that the cation type has a strong influence on the amino acids partitioning process. The largest relative hydrophobicity was noted for the ATPS system formed by sodium sulfate. This showed to be a better system for the separation.FCT/MEC and FEDER under Programe PT2020 (Project UID/EQU/50020/2013), and co-financed by QREN, ON2 and FEDER (Projects NORTE-07-0162-FEDER-000050 and NORTE-07-0124-FEDER-0000011

Laccase partition in ATPS: finding some molecular descriptors

Aqueous Two-Phase Systems (ATPS) are known since 1896, when Beijerinck reported the formation of a biphasic system after mixing aqueous solutions of gelatine and agar or gelatine and starch. However, only in the 50’s, Albertsson showed the potential of these systems in the separation and purification of several biological constituents.1 In general, ATPS are obtained by mixing two aqueous solutions of different constituents that become immiscible above certain critical conditions, like temperature, concentration, etc. Both phases are composed mainly by water (>80%) and each one is enriched in a different component. ATPS formed by two polymers or a polymer and a salt represent the traditional systems. Nevertheless, other alternative biphasic systems can be obtained using surfactants, micellar compounds or ionic liquids

Gibbs free energy of transfer of a methylene group on {UCON + (sodium or potassium) phosphate salts} aqueous two-phase systems: Hydrophobicity effects

The Gibbs free energy of transfer of a suitable hydrophobic probe can be regarded as a measure of the relative hydrophobicity of the different phases. The methylene group (CH2) can be considered hydrophobic, and thus be a suitable probe for hydrophobicity. In this work, the partition coefficients of a series of five dinitrophenylated-amino acids were experimentally determined, at 23 °C, in three different tie-lines of the biphasic systems: (UCON + K2HPO4), (UCON + potassium phosphate buffer, pH 7), (UCON + KH2PO4), (UCON + Na2HPO4), (UCON + sodium phosphate buffer, pH 7), and (UCON + NaH2PO4). The Gibbs free energy of transfer of CH2 units were calculated from the partition coefficients and used to compare the relative hydrophobicity of the equilibrium phases. The largest relative hydrophobicity was found for the ATPS formed by dihydrogen phosphate salts.Fundação para a Ciência e a Tecnologia (FCT) - Programa "Ciência 2007", SFRH/BD/43439/2008LSREFEDER/POCI/201

Screening of fungal sources of -galactosidase with potential for the synthesis of prebiotics

Book of Abstracts of CEB Annual Meeting 2017[Excerpt] β-Galactosidases (EC 3.2.1.23), also known as lactases, are a family of enzymes able to catalyse two different types of reactions, namely hydrolysis and transgalactosylation. The hydrolytic activity is commonly applied in the food industries to reduce the lactose content of dairy products, preventing lactose crystallization problems and increasing sweetness, flavour and solubility. On the other hand, transgalactosylation reactions have been explored in the synthesis of lactose-based prebiotics, such as galacto-oligosaccharides (GOS), lactosucrose [1] and lactulose [2], with potential application in the pharmaceutical and food industry. These prebiotics are enzymatically produced through the hydrolysis of lactose and further transfer of a galactosyl residue to a suitable acceptor, i.e. fructose for the disaccharide lactulose; sucrose for the trisaccharide lactosucrose; and lactose for GOS. The sources of βgalactosidase are extensively distributed in nature, namely in microorganisms, plants and animal organs. [...]info:eu-repo/semantics/publishedVersio

Polyethylene glycol 8000+ citrate salts aqueous two-phase systems: Relative hydrophobicity of the equilibrium phases

The Gibbs free energy of transfer of a methylene group, G*(CH2), is reported as a measure of the relative hydrophobicity of the equilibrium phases. Furthermore, G*(CH2) is a characteristic parameter of each tie-line, and for that reason can be used for comparing different tie-lines of a given aqueous two-phase system (ATPS) or even to establish comparisons among different ATPSs. In this work, the partition coefficients of a series of four dinitrophenylated-amino acids were experimentally determined, at 23 °C, in five different tie-lines of PEG8000(sodium or potassium) citrate ATPSs. G*(CH2) values were calculated from the partition coefficients and used to evaluate the relative hydrophobicity of the equilibrium phases. PEG8000potassium citrate ATPSs presented larger relative hydrophobicity than PEG8000sodium citrate ATPSs. Furthermore, the results obtained indicated that the PEG-rich phase (top phase) has higher affinity to participate in hydrophobic hydration interactions than the salt-rich phase (bottom phase).This work was partially supported by FCT/MEC and FEDER under Programe PT2020 (Project UID/EQU/50020/2013), and co-financed by QREN, ON2 and FEDER (Projects NORTE-07-0162FEDER-000050 and NORTE-07-0124-FEDER-0000011), for which the authors are thankful. SCS alsoa cknowledges her post-doc grant (SFRH/BPD/88584/2012) from FCT

Perspectives on the biotechnological production and potential applications of lactosucrose: A review

Lactosucrose is a synthetic trisaccharide composed of galactose, glucose and fructose. This compound is obtained through enzymatic synthesis using lactose and sucrose as substrates. The enzymes involved in the process are able to catalyse both hydrolysis and transfer reactions. The yield and productivity of the process are usually affected by the occurrence of parallel hydrolysis of the newly formed product (lactosucrose). Therefore, it is important to find efficient strategies to avoid or minimize product degradation. Furthermore, in the last decades the demand for lactosucrose has significantly increased. This compound is considered a potential prebiotic and several beneficial effects associated to its consumption have been described. As a result, it has been included in the formulations of functional foods. This review covers the most relevant information about lactosucrose, including its synthesis and purification, beneficial effects at physiological level, and also its potential applications.Fundação para a Ciência e a Tecnologia (FCT) Strategic Project of UID/BIO/04469/2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and the project “BioInd – Biotechnology and Bioengineering for im- proved Industrial and Agro-Food processes”, REF. NORTE-07- 0124-FEDER-000028 co-funded by the Programa Operacional Regional do Norte (ON. 2–ONovo Norte), QREN, FEDER

Biocatalytic approaches using lactulose: end product compared with substrate

Lactulose is a lactose-based carbohydrate with well-known prebiotic effect and recognized medical applications. Currently, the commercially available lactulose is chemically synthesized. Nevertheless, the process leads to low yields and high levels of by-products. Alternatively, lactulose can be produced by enzymatic synthesis, which provides a cleaner production under mild conditions. Two different enzymatic routes were reported for lactulose production. Lactulose can be obtained through hydrolysis and transfer reactions catalyzed by a glycosidase. Alternatively, lactulose can be produced by direct isomerization of lactose to lactulose catalyzed by cellobiose-2-epimerase. An interesting characteristic of lactulose is also its capacity to act as substrate in additional enzymatic synthesis which leads to the formation of attractive compounds, such as lactulose-based oligosaccharides and lactulose esters. Besides increasing the interest and potential of lactulose, these lactulose-based compounds can also offer new and promising functionalities and applications. Herein, we review the enzymes involved in the synthesis of lactulose, as well as the reaction conditions and yields. The potential of different enzymes is discussed and it is shown that reaction conditions and composition of products depend on the type of enzyme and its microbial source. The conversion of lactulose into lactulose-based compounds is also covered, describing in detail the biocatalysts involved, the reaction conditions used, and the potential of the final products obtained.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). The authors also thank the FCT for the financial support under the scope of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). SCS also acknowledges her post doc grant (SFRH/BPD/88584/2012) from FCT

Simultaneous synthesis of prebiotic mixtures containing GOS and FOS

FCT (UID/BIO/04469/2013 unit); COMPETE 2020 (POCI-01-0145-FEDER- 006684); project BioTecNorte (NORTE-01-0145-FEDER-000004) and project MultiBiorefinery (POCI-01-0145-FEDER-016403) funded by the European Regional Development Fund under the scope of Norte2020. SCS acknowledges her grant (SFRH/BPD/88584/2012) from FCTinfo:eu-repo/semantics/publishedVersio