http://hdl.handle.net/10174/639 Fri, 03 Apr 2026 13:53:14 GMT 2026-04-03T13:53:14Z http://hdl.handle.net/10174/31272 Title: Plant Extracts as Green Corrosion Inhibitors Authors: Furtado, Luana; Nascimento, Rafaela Editors: Hussain, Chaudhery; Verma, Chandrabhan Abstract: Adsorption inhibitors are considered efficient due to their structural characteristics, such as high electron density and heteroatom groups that can adsorb onto and protect metallic surfaces. Adsorption involves interaction between organic molecules and the metallic substrate, mainly in acidic or saline media. Factors such as temperature, immersion time, inhibitor concentration, and the presence of intensifiers or surfactants favor this process. As previously reported, higher temperatures can improve inhibition efficiency when molecules are chemically adsorbed, while performance declines in physically adsorbed molecules. Efficiency increases over short immersion times and stabilizes thereafter, whereas longer exposure can lead to molecule desorption and decreased efficiency. Substances like surfactants and ions can assist in the adsorption process. The predominant type of adsorption results from the structural characteristics of the inhibitor molecules that combine synergistically with other compounds. Plant extracts are a complex mixture of organic compounds, primarily alcohols, phenols, amines, amides, ethers, and others. Extraction conditions influence the type and amount of compound extracted. Water and ethanol have been used as solvents under temperatures up to 353 K. Increased temperatures improve compound solubility and diffusion rate, although excessively high temperatures should be avoided since they may cause the compounds to decompose. Mon, 15 Nov 2021 00:00:00 GMT http://hdl.handle.net/10174/31272 2021-11-15T00:00:00Z http://hdl.handle.net/10174/26347 Title: Evaluation of the Length of Hospital Stay through Artificial Neural Networks based Systems Authors: Abelha, Vasco; Marins, Fernando; Vicente, Henrique Editors: Information Resources Management Association Abstract: The mentality of savings and eliminating any kind of outgoing costs is undermining our society and our way of living. Cutting funds from Education to Health is at best delaying the inevitable “Crash” that is foreshadowed. Regarding Health, a major concern, can be described as jeopardize the health of Patients – Reduce of the Length of Hospital. As we all know, Human Health is very sensitive and prune to drastic changes in short spaces of time. Factors like age, sex, their ambient context – house conditions, daily lives – should all be important when deciding how long a specific patient should remain safe in a hospital. In no way, ought this to be decided by the economic politics. Logic Programming was used for knowledge representation and reasoning, letting the modeling of the universe of discourse in terms of defective data, information and knowledge. Artificial Neural Networks and Genetic Algorithms were used in order to evaluate and predict how long should a patient remain in the hospital in order to minimize the collateral damage of our government approaches, not forgetting the use of Degree of Confidence to demonstrate how feasible the assessment is. Wed, 01 Jan 2020 00:00:00 GMT http://hdl.handle.net/10174/26347 2020-01-01T00:00:00Z http://hdl.handle.net/10174/25884 Title: A Smart Approach to Harvest Date Forecasting Authors: Charneca, Beatriz; Santos, Vanda; Crespo, Ana; Vicente, Henrique; Chaves, Humberto; Ribeiro, Jorge; Alves, Victor; Neves, José Editors: Gonçalves, Paulo; Calado, João Abstract: The concept of grape ripeness depends not only on the degree of enrichment of the chemical compounds in the grape and the volume of the berries, but also on the possible production purposes. The different types of maturation in individual cases are not sufficient for the decision on the harvest date. Taken together, however, they define oenological maturation times and help to harvest them. However, there are no consistent studies that correlate the chemical parameters obtained from must analysis and oenological maturation due to the nonlinearity of these two types of variables. Therefore, this work seeks to create a self-explanatory model that allows for the prediction of ideal harvest time, based on eneological parameters related to practices in new developments in knowledge acquisition and management in relational databases. Tue, 01 Jan 2019 00:00:00 GMT http://hdl.handle.net/10174/25884 2019-01-01T00:00:00Z http://hdl.handle.net/10174/24174 Title: Waste of biodiesel production: conversion of glycerol into biofuel additives Authors: Castanheiro, j; Pinto, p; Carlota, S Editors: Vilarinho, C; Castro, F; Lopes, M Abstract: The condensation of glycerol with acetone was performed using silicotungstic acid (SiW) immobilized in SBA-15, at 70ºC. The main product of glycerol acetalization was solketal. Different techniques were used to characterize the catalysts. A series of catalysts with dif-ferent heteropolyacid loading were prepared. It was observed that the catalytic activity in-creases with the amount of SiW immobilized in SBA-15, being the SiW2@SBA-15 (with 7.8 wt. %) the most active sample. All catalyst exhibited good values of selectivity to sol-ketal (about 99% near complete conversion). To optimize the reaction conditions, the ef-fect of different reaction parameters (catalyst loading, molar ratio of glycerol to acetone and temperature), on the glycerol acetalization over the SiW2@SBA-15 catalyst, was stud-ied. Catalytic stability of the SiW2@SBA-15 was evaluated by performing consecutive batch runs with the same catalyst sample. It was observed that, after the third use, the cata-lytic activity stabilized. Mon, 01 Jan 2018 00:00:00 GMT http://hdl.handle.net/10174/24174 2018-01-01T00:00:00Z