The first synthesis of glycosylflavanones catalyzed by praseodymium triflate:a straightforward approach to potential antidiabetic agents

Tese de doutoramento, Química (Química-Orgânica), Universidade de Lisboa, Faculdade de Ciências, 2013Fundação para a Ciência e a Tecnologia (FCT, SFRH/BD/30699/2006

Study of the leaching alterability in Soxhlet Extractor of ceramic materials with incorporation of ashes resulting from the incineration of urban solid waste

Population expansion, especially in metropolitan areas, has led to an increase in the production of urban solid waste (USW) by domestic and commercial activity in urban centres. Reducing the production of these wastes is an extremely difficult task. However, the reduction processes, themselves, have the potential to produce a number of useful residues. This study focuses on the residues of incinerated USW, which produces ashes of varying compositions. This study investigates a mixture of two ashes, one resulting from the incineration of USW from LIPOR II (Intermunicipal Waste Management Service of Porto Region) and another from ValorSul (Valorisation and Treatment of Solid Waste of Lisbon and West Regions), both processed by EcoInCer (Ecological Innovations Ceramics company). Ashes from several samples of USW incorporating clays were tested to identify physical and mechanical characterisations, with a view to identifying useful ecological ceramic materials which could be  used  by the ceramics industry. Ceramic samples with 0%, 10% and 20% of ashes were incorporated in a clay matrix composed of 5% kaolin and 95% red clay, and submitted to leaching alterability in Soxhlet Extractor. The obtained results demonstrate the ways in which the ash percentage and the firing temperature can be important in the alterability of a ceramic material. Keywords: Ceramic materials, Leaching, Urban solid wast

Approximating fractional derivatives in the perspective of system control

The theory of fractional calculus goes back to the beginning of the theory of differential calculus, but its application received attention only recently. In the area of automatic control some work was developed, but the proposed algorithms are still in a research stage. This paper discusses a novel method, with two degrees of freedom, for the design of fractional discrete-time derivatives. The performance of several approximations of fractional derivatives is investigated in the perspective of nonlinear system control

A new method for approximating fractional derivatives: application in non-linear control

The theory of fractional calculus goes back to the beginning of the theory of differential calculus, but its application received attention only recently. In the area of automatic control some work was developed but the proposed algorithms are still in a research stage. This paper discusses a novel method, with two degrees of freedom, for the design of fractional discrete-time derivatives. The performance of several approximations of fractional derivatives is investigated in the perspective of nonlinear system control.N/

Alternative methods to synthetic chemical control of Cynodon dactylon (L.) Pers. A systematic review

ABSTRACT: Cynodon dactylon (L.) Pers. is one of the worst agricultural weeds and invasive species in the world, being widely established in many countries. Despite its impact on agriculture and the growing awareness of authorities and consumers about the consequences of synthetic herbicides, alternative control methods for this weed have been poorly reviewed. A systematic review of the literature published over the last 50 years was used to assess the most studied control methods of C. dactylon (excluding synthetic herbicides) and to summarize the trends and knowledge gaps. The major fndings are as follows: (1) the number of publications that studied alternative methods to synthetic chemical control in C. dactylon management has been increasing exponentially since 1972; (2) most of the studies were made under controlled conditions (57%) and lack observations under real production conditions; (3) most of the feld experiments were carried out in Asia (42%), under temperate subtropical and arid climates; (4) the publication of articles studying allelopathy stands out signifcantly (50% of the papers found), with two species from the Poaceae family, rice (Oryza sativa L.) and sorghum (Sorghum bicolor (L.) Moench), showing very high allelopathic inhibitory efects (often above 80%), especially under open feld conditions; and (5) preventive soil tillage is the most studied treatment among indirect weed control treatments, and although there is a high risk of propagation, the results indicate that tillage can signifcantly contribute to control C. dactylon, when compared to no-tillage treatments. Further research is needed to optimize treatments and methods so that they can be applied by farmers under real production conditions.info:eu-repo/semantics/publishedVersio