1,019 research outputs found
Fuzzy control of a water pump for an agricultural plant growth system
At the present time there is a high pressure toward the improvement of all the production processes. Those
improvements can be sensed in several directions in particular those that involve energy efficiency. The definition
of tight energy efficiency improvement policies is transversal to several operational areas ranging from
industry to public services. As can be expected, agricultural processes are not immune to this tendency. This
statement takes more severe contours when dealing with indoor productions where it is required to artificially
control the climate inside the building or a partial growing zone. Regarding the latter, this paper presents an
innovative system that improves energy efficiency of a trees growing platform. This new system requires the
control of both a water pump and a gas heating system based on information provided by an array of sensors.
In order to do this, a multi-input, multi-output regulator was implemented by means of a Fuzzy logic
control strategy. Presented results show that it is possible to simultaneously keep track of the desired growing
temperature set-point while maintaining actuators stress within an acceptable range.This work is financed by the ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT -Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project “*FCOMP-01-0124-FEDER-037281*
Active center determination of ethylene polymerisation catalysts using a quenching method with tritiated methanol
The subject of this work is ethylene polymerisation using Kaminsky type catalysts: Cp2MR2=methylaluminoxane [M=Zr,W,Nb; R=Cl,CH3]. Active center determination and kinetic studies of the (Cp2WCl2 + methylaluminoxane) and Cp2ZrCl2 + methylaluminoxane) systems are described, using a quenching method with tritiated methanol. The activity of the polymer was determined by liquid scintillation counting. We have found 0.5% and 87% of active centers, respectively for W and Zr system. The catalytic activity of complexes Cp2WCl2 and Cp2NbCl2 was compared with that of Cp2ZrCl2. The W and Nb complexes are found to be less active than the Zr complex.info:eu-repo/semantics/publishedVersio
Aspectos fitossanitários em olival na Beira Interior Norte e na Beira Interior Sul
Comunicação oral apresentada no 6.º Encontro Nacional de Protecção Integrada que decorreu em Castelo Branco, na Escola Superior Agrária do Instituto Politécnico de Castelo Branco, no âmbito do painel sobre o OlivalPara uma análise dos problemas fitossanitários do olival na Beira Interior foram realizados observações e
estimativas do risco, em 2002, em quatro olivais na Beira Interior Norte e outros quatro na Beira Interior Sul.
Os olivais da Beira Interior Norte ficam localizados nos concelhos de Seia, Pinhel, Guarda e Figueira de
Castelo Rodrigo e os da Beira Interior Sul nos concelhos de Penamacor, Fundão, Proença-a-Nova e Vila Velha
de Ródão. Os inimigos mais importantes e para que foram feitas estimativas do risco foram: gafa, olho de
pavão, mosca-da-azeitona, traça-da-oliveira e cochonilha-negra.
Em todos os olivais foram encontrados todos os inimigos avaliados, mas com pouca expressão para o olho de
pavão nos olivais da cultivar Galega. Os dados da estimativa do risco são apresentados, assim como o número
das intervenções químicas que foram necessárias realizar. São discutidas e comparadas as intervenções
realizadas
A new plant growth system rig based on thermodynamic solar energy: a study for energy efficiency assessment
At the present there is a high pressure toward the improvement
of all production processes. Those improvements can target distinct
factors along the production chain. In particular, and due to recent tight
energy efficiency policies, those that involve energy efficiency. As can be
expected, agricultural processes are not immune to this tendency. Even
more when dealing with indoor productions. In this context, this work
presents an innovative system that aims to improve the energy efficiency
of a trees growing platform. This improvement in energy consumption
is accomplished by replacing an electric heating system by one based
on thermodynamic panels. The assessment of the heating fluid caudal
and its temperature was experimentally obtained by means of a custom
made scaled prototype whose actuators status are commanded by a
Fuzzy-based controller. The obtained results suggest that the change in
the heating paradigm will lead to overall savings that can easily reach
60% on the energy bill.This work is financed by the Project TEC4Growth - Pervasive Intelligence, Enhancers and Proofs of Concept with Industrial Impact / NORTE-01-0145-FEDER-000020”, which is financed by the North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, and through the European Regional Development Fund (ERDF)
The interaction of La3+ complexes of DOTA/DTPA-glycoconjugates with the RCA120 lectin : a saturation transfer difference (STD) NMR spectroscopic study
The study of ligand-receptor interactions using high resolution NMR techniques, namely the Saturation Transfer Difference (STD), is presented for the recognition process between La(III) complexes of DOTA mono(amide) and DTPA bis(amide) glycoconjugates and the galactose specific lectin Ricinus Communis agglutinin (RCA120). This new class of Gd(III)-based potential targeted MRI contrast agents (CAs), bearing one or two terminal sugar (galactosyl or lactosyl) moieties, has been designed for in vivo binding to ASGPR (the asialoglycoprotein receptor), which is specifically expressed at the surface of liver hepatocytes, with the aim of leading to a new possible diagnosis of liver pathologies. The in vitro affinity constants of the divalent La(III)- glycoconjugate complexes to RCA120, used as a simple, water soluble receptor model, were higher than those of the monovalent analogues. The combination of the experimental data obtained from the STD NMR experiments with molecular modelling protocols (Autodock 4.1) allowed us to predict the binding mode of mono and divalent forms of these CAs to the galactose 1 binding sites of RCA120. The atomic details of the molecular interactions allowed corroborating and supporting the interaction of both the sugar moieties and the linkers with the surface of the protein and thus, their contribution to the observed interaction stabilities.Fundação para a Ciência e a Tecnologia (FCT
Siderophore Production by Pathogenic Mucorales and Uptake of Deferoxamine B
Clinical reports have established that mucormycosis, mainly caused by Rhizopus spp., frequently occurs in patients treated with deferoxamine B (DFO, Desferal®) which is misappropriated by these fungi. Siderophore production by twenty mucoralean isolates was therefore investigated using a commercial iron-depleted culture medium. Siderophore production was detected for most of the isolates. Our experiments confirmed that feroxamine B (iron chelate of DFO) promoted in vitro growth of Rhizopus arrhizus. Electrophoretic analysis of somatic extracts revealed iron-regulated proteins of 60 and 32 kDa which were lacking in iron-depleted culture conditions. Using a fluorescent derivative of deferoxamine B, we showed by fluorescence microscopy the entry of the siderophore within the fungal cells, thus suggesting a shuttle mechanism encompassing the uptake of the entire siderophore-ion complex into the cell. This useful tool renders possible a better understanding of iron metabolism in Mucorales which could lead to the development of new diagnostic method or new antifungal therapy using siderophores as imaging contrast agents or active drug vectors
BF models, Duality and Bosonization on higher genus surfaces
The generating functional of two dimensional field theories coupled to
fermionic fields and conserved currents is computed in the general case when
the base manifold is a genus g compact Riemann surface. The lagrangian density
is written in terms of a globally defined 1-form and a
multi-valued scalar field . Consistency conditions on the periods of
have to be imposed. It is shown that there exist a non-trivial dependence of
the generating functional on the topological restrictions imposed to . In
particular if the periods of the field are constrained to take values , with any integer, then the partition function is independent of the
chosen spin structure and may be written as a sum over all the spin structures
associated to the fermions even when one started with a fixed spin structure.
These results are then applied to the functional bosonization of fermionic
fields on higher genus surfaces. A bosonized form of the partition function
which takes care of the chosen spin structure is obtainedComment: 17 page
Relating physicochemical and microbiological safety indicators during processing of linguiça, a Portuguese traditional dry-fermented sausage
Linguiça is a Portuguese traditional fermented sausage whose microbiological quality and safety can be highly variable. In order to elucidate risk factors and the particularities of the manufacturing technology that explain the between-batch variability in total viable counts (TVC), Enterobacteriaceae, Staphylococcus aureus and Listeria monocytogenes in the product; microbiological and physicochemical characterisation of linguiça at five stages of production (i.e., raw pork meat, mixed with ingredients, macerated, smoked and ripened) was carried out. A total of six production batches were surveyed from two factories; one utilised curing salts and polyphosphate in their formulation (Factory II). The delayed fermentation in the nitrite-formulated sausages was partly responsible for the increase (p < 0.01) in Enterobacteriaceae, S. aureus and L. monocytogenes from raw meat (3.21logCFU/g, 1.30logCFU/g and 22.2CFU/g, respectively) to the end of maceration (4.14logCFU/g, 2.10logCFU/g and 140CFU/g, respectively) while the better acidification process in the nitrite-free sausages (Factory I) led to lower counts of S. aureus (2.64logCFU/g) and L. monocytogenes (10CFU/g) in the finished products. In Factory II, although L. monocytogenes entered the chain at the point of mixing, it became steadily inactivated during smoking and ripening ( < 50CFU/g), despite the initially-delayed fermentation. Nitrite had a strong effect on reducing Enterobacteriaceae throughout smoking (r=-0.73) and ripening (r=-0.59), while it failed to control the growth of S. aureus. The main hurdle preventing the development of S. aureus in linguiça is the pH, and other factors contributing to its control are: longer ripening days (p=0.019), low S. aureus in raw meat (p=0.098), properly-washed casings (p=0.094), and less contamination during mixing (p=0.199). In the case of L. monocytogenes, at least three hurdles hinder its development in linguiça: low a w (p=0.004), low pH (p=0.040) and nitrite (p=0.060), and other factors contributing to its control are: longer ripening (p=0.072) and maceration (p=0.106) periods, lower a w at the end of smoking (p=0.076) and properly-washed casings (p=0.099). Results have shown that there is a need to standardise the productive process of linguiça, to optimise the initial acidification process, and to reinforce proper programmes of quality control of ingredients and good hygiene practices, so as to minimise the introduction of Enterobacteriaceae and pathogens from external sources.This research was supported through the project PTDC/AGR-TEC/3107/2012, awarded by the Portuguese Foundation for Science and
Technology (FCT), European Regional Development Funds (ERDF). Dr.
Gonzales-Barron also acknowledges the financial support provided by
FCT through the award of a five-year Investiginfo:eu-repo/semantics/publishedVersio
Accidental Inflation in the Landscape
We study some aspects of fine tuning in inflationary scenarios within string
theory flux compactifications and, in particular, in models of accidental
inflation. We investigate the possibility that the apparent fine-tuning of the
low energy parameters of the theory needed to have inflation can be generically
obtained by scanning the values of the fluxes over the landscape. Furthermore,
we find that the existence of a landscape of eternal inflation in this model
provides us with a natural theory of initial conditions for the inflationary
period in our vacuum. We demonstrate how these two effects work in a small
corner of the landscape associated with the complex structure of the Calabi-Yau
manifold P^4_[1,1,1,6,9] by numerically investigating the flux vacua of a
reduced moduli space. This allows us to obtain the distribution of observable
parameters for inflation in this mini-landscape directly from the fluxes.Comment: 40 pages, 11 figure
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