Encontrados 13 documentos, a visualizar página 1 de 2
Mycorrhizal synthesis between Pisolithus arhizus and adult clones of Arbutus un...
Gomes, Filomena; Machado, Helena; San Martin, Esteban; Portugal, A.; Canhoto, J. M.Arbutoid mycorrhizae were synthesized between adult selected clones of Arbutus unedo L. and Pisolithus arhizus. Two micropropagated clones were tested: AL1, in vitro and C1 (acclimatized plants) in nursery and later in a field trial. In vitro, rooted shoots were transferred to test tubes containing the substrate previously inoculated with mycelium cultured on agar. In the nursery, two inoculation treatments wer...
Flow cytometry as a tool to assess the effects of gamma radiation on the viabil...
Mesquita, N.; Portugal, A.; Piñar, G.; Loureiro, J.; Coutinho, A. P.; Trovão, J.; Nunes, I.; Botelho, M. L.; Freitas, H.Flow cytometry is often used for viability and vitality assessment in bacteria and yeasts. However, its application to the study of fungal spore development is uncommon, probably due to the difficulties in successfully staining these cells. In the current study, we used flow cytometry for the first time to assess the effects of a disinfection treatment on the survival, growth and metabolic activity of fungal sp...
MOTIVATION AND PERFORMANCE IN A BUSINESS SIMULATION COURSE
M. Pinheiro, Margarida; Universidade de Aveiro, Portugal; S. Sarrico, Cláudia; Universidade Técnica de Lisboa, PortugalIn order to enhance graduatesʼ performance in the labour market a one semester Business Simulation course was designed and implemented. The course participants are students of the last semester in a PBL-type undergraduate Portuguese Accounting program. This work focuses on thepower of learning environments, namely the ones inspired by PBL, to influence studentsʼ motivations; and asks to what extent motivation c...
Low-Temperature FTIR Spectroscopic and Theoretical Study on an Energetic Nitroi...
Simões, P. N.; Reva, I.; Pedroso, L. M.; Fausto, R.; Portugal, A. A.This paper presents an overview of recent progress in spectroscopic studies of the energetic nitroimine 4,6-bis(nitroimino)-1,3,5-triazinan-2-one (DNAM), based on experimental and theoretical data. The following topics are considered: variable temperature FTIR spectroscopy (4000−400 cm-1) applied to the study of natural and isotopically substituted (deuterated) samples aiming to obtain a successful vibrational...
Crystal and Molecular Structure of 4,6-Bis(nitroimino)-1,3,5-triazinan-2-one: ...
Simões, P. N.; Pedroso, L. M.; Beja, A. M. Matos; Silva, M. Ramos; MacLean, Elizabeth; Portugal, A. A.This paper provides an overview of recent progress on structural data on the title compound. Theoretical work based on quantum mechanical calculations was performed to gain some understanding on the heterocyclic tautomerism potentially exhibited by the compound. The computational studies encompassed a wide range of tautomers/conformers, allowing the determination of the most probable molecular structure. In the...
Cyanuric acid-epichlorohydrin prepolymers
Pedroso, L. M.; Simões, P.; Portugal, A.In this study, we investigated the reaction of cyanuric acid and epichlorohydrin (ECH). SnCl4 was used as a catalyst. Several reaction conditions were tested, and the products were analyzed by means of Fourier transform infrared and 1H-NMR spectroscopy, hydroxyl group content, molar mass, elemental and thermal analysis, viscosity, and density. ECH reacted with the amine groups of the cyanuric acid ring to form ...
New Propellant Component, Part II. Study of a PSAN/DNAM/HTPB Based Formulation
Simões, P.; Pedroso, L.; Portugal, A.; Plaksin, I.; Campos, J.A study of DNAM as a candidate ingredient for propellant formulations is reported. A formulation including DNAM and based on Phase Stabilized Ammonium Nitrate (PSAN) and Hydroxy-Terminated-Poly Butadiene (HTPB) was selected for the study. This includes thermoanalytical measurements on the mixtures of solid components and propellant samples. Performance is assessed by burning rate measurements. A new small-scale...
New Propellant Component, Part I. Study of 4,6-Dinitroamino-1,3,5-Triazine-2(1 ...
Simões, P.; Pedroso, L.; Portugal, A.; Carvalheira, P.; Campos, J.This paper reports a study of the synthesis and characterization of 4,6-dinitroamino-1,3,5-triazine-2(1 H)-one (DNAM) carried out under the perspective of looking for new ingredients in propellant formulations. Emphasis is given to the characterization of DNAM. The following attributes were identified: low sensitivity to impact and friction, thermal stability over a wide temperature range, energetic nature, hig...
Characterisation of the surface of a cellulosic multi-purpose office paper by i...
Santos, J. M. R. C. A.; Gil, M. H.; Portugal, A.; Guthrie, J. T.The surface of multi-purpose cellulosic office paper has been analysed by inverse gas chromatography (IGC). The parameters determined were the dispersive component of the surface free energy, the enthalpy of adsorption and the entropy of adsorption of polar and apolar probes, the Lewis acidity constant, Ka, and the Lewis basicity constant, Kb. It can be concluded that the dispersive component of the surface fre...
Thermal decomposition of solid mixtures of 2-oxy-4,6-dinitramine-s-triazine (DN...
Simões, P. N.; Pedroso, L. M.; Portugal, A. A.; Campos, J. L.The thermal decomposition of solid mixtures of 2-oxy-4,6-dinitramine-s-triazine (DNAM) and phase stabilized ammonium nitrate (PSAN) at different mass ratios has been studied. Simultaneous thermal analysis (DSC/TG) and thermomicroscopy have been used. It was found that PSAN promotes the lowering of the decomposition temperature of DNAM. The beginning of this process occurs when both components are in the solid s...
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