Search results for "Industrial and Manufacturing Engineering"
showing 10 items of 1866 documents
Methods used to evaluate the peroxyl (ROO·) radical scavenging capacities of four common antioxidants
2012
Different methods that are used to measure peroxyl radical (ROO) scavenging capacity were used in model systems containing four common antioxidant compounds: ascorbic acid, cysteine, gallic acid and Trolox, a water-soluble vitamin E analogue. Five tests were performed, with differences in the method of peroxyl radical generation (lipoxygenase, azo-compound thermal degradation and spontaneous oxidation from a natural source of fatty acids) and in the addition of probes such as linoleic acid, crocin, fluorescein and electron paramagnetic resonance (EPR) by spin-trapping with a-phenyl-N-tert-butylnitrone. Significant differences were found in antioxidant reactivity, evaluated by dose–effect se…
Understanding the potential benefits of thyme and its derived products for food industry and consumer health: From extraction of value-added compound…
2018
Natural bioactive compounds isolated from several aromatic plants have been studied for centuries due to their unique characteristics that carry great importance in food, and pharmaceutical, and cosmetic industries. For instance, several beneficial activities have been attributed to some specific compounds found in Thymus such as anti-inflammatory, antioxidant, antimicrobial, and antiseptic properties. Moreover, these compounds are classified as Generally Recognized as Safe (GRAS) which means they can be used as an ingrident of may food producs. Conventional extraction processes of these compounds and their derived forms from thyme leaves are well established. Hoewever, they present some im…
Quality parameters, bioactive compounds and their correlation with antioxidant capacity of commercial fruit-based baby foods
2013
Comprehensive research is required to achieve the optimization of the antioxidant protection through baby foods, in particular, the commercially available fruit-based baby foods. This study investigated the physicochemical properties, ascorbic acid (AA), total carotenoids (TC), total phenolic content (TPC), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) of 23 different commercially available fruit-based baby foods. The main contribution to the total antioxidant capacity (trolox equivalent antioxidant capacity and oxygen radical absorbance capacity) was provided by ascorbic acid, followed by phenolic compounds, in accordance with a mathematical e…
Photocatalytic degradation of dyes by using a membrane reactor
2004
Abstract Dyes are organic compounds used in textile, food and drug industries, and their abatement represents one of the main problems in the treatment processes because generally they are very stable toxic compounds. In this work, two commercial azo-dyes, i.e. Congo Red (C32H22N6Na2O6S2) and Patent Blue (C27H31N2NaO6S2), in aqueous solution were degraded in a photocatalytic membrane reactor by using TiO2 Degussa P25 as the catalyst. Different system configurations and irradiating sources were studied, and the influence of some operational parameters such as the pressure in the membrane cell and the initial concentration of the substrates was determined. A comparison between suspended and e…
Gas assisted mechanical expression (GAME) for the selective recovery of lipophilic and hydrophilic compounds from olive kernel
2017
Abstract This work is devoted to valorize olive kernel; a by-product produced during olive oil extraction process. For this purpose, aqueous liquid solid extraction (LSE), mechanical expression (ME), supercritical CO2 (SC-CO2) and gas assisted mechanical expression (GAME), processes were compared when applied separately or consequently (ME + GAME), in terms of total phenolic compound (TPC) and oil recovery yields. Results showed that although the high extraction yields of TPC using LSE (61.4 ± 1.3%), the extraction process is economically not viable. However, it was demonstrated that applying ME (1 h at 30 MPa) followed by GAME (1 h at 30 MPa ME and 10 MPa SC-CO2 pressures) allowed recoveri…
Reactor model for fast reactions in the micro-bubble column and validation
2007
A simple reactor model for predicting conversions in a micro-bubble column is described. It assumes fast reactions so that the gaseous component is readily consumed at the gas-liquid interface. Then, gas-liquid mass transfer becomes determining. As input parameters for the model, the hydrodynamics, specific interfacial area, and mass transport need to be described. Two fast model reactions, the catalytic oxidation of butyraldehyde and the absorption of CO2 in aqueous NaOH, show the applicability of the model but also its limits. The model was used for predicting reaction performance in dependence of operating conditions, in particular to get maximum conversion with the antagonistic paramete…
A calcined clay fixed bed adsorption studies for the removal of heavy metals from aqueous solutions
2021
Abstract A natural clay material from southern Tunisia was used as a low cost sorbent in a column-wise removal of metal pollutants. This is fundamentally important for a sustainable wastewater treatment strategy. This work has been performed within the framework of a project aiming to the valorization of natural geomaterials, from Tunisia, in several environmental applications. Column adsorption experiments were carried out for a better production of cleaner effluents and further understanding of the main mechanisms involved in the removal process, through a dynamic methodology, that would allow an industrial scale treatment. A calcined clay sample was used as an adsorbent for the removal o…
A branch-and-cut algorithm for the Profitable Windy Rural Postman Problem
2016
[EN] In this paper we study the profitable windy rural postman problem. This is an arc routing problem with profits defined on a windy graph in which there is a profit associated with some of the edges of the graph, consisting of finding a route maximizing the difference between the total profit collected and the total cost. This problem generalizes the rural postman problem and other well-known arc routing problems and has real-life applications, mainly in snow removal operations. We propose here a formulation for the problem and study its associated polyhedron. Several families of facet-inducing inequalities are described and used in the design of a branch-and-cut procedure. The algorithm…
Solving the length constrained K-drones rural postman problem
2021
[EN] In this paper we address the Length Constrained K-Drones Rural Postman Problem (LC K-DRPP). This is a continuous optimization problem where a fleet of homogeneous drones have to jointly service (traverse) a set of (curved or straight) lines of a network. Unlike the vehicles in classical arc routing problems, a drone can enter a line through any of its points, service a portion of that line, exit through another of its points, then travel directly to any point on another line, and so on. Moreover, since the range of the drones is restricted, the length of each route is limited by a maximum distance. Some applications for drone arc routing problems include inspection of pipelines, railwa…
Artificial neural network decision support tool for assessment of the energy performance and the refurbishment actions for the non-residential buildi…
2017
The public buildings sector represents one of the most intensive items of EU energy consumption; the application of retrofit solutions in existing buildings is a crucial way to reduce its impact. To facilitate the knowledge of the energy performance of existing non-residential buildings and the choice of the more adequate actions, Public Administrations (PA) should have the availability of proper tools. Within the Italian project "POI 2007-13", a database and a decision support tool, for easy use, even to a non-technical user, have been developed. A large set of data, obtained from the energy audits of 151 existing public buildings located in four regions of South Italy have been analysed, …