2,107 research outputs found
Avaliação termográfica de instalações de refrigeração
Numa sociedade em que a utilização racional de energia constitui cada vez mais uma prioridade, é pertinente a avaliação do desempenho energético dos equipamentos que actualmente se encontram em funcionamento nas diferentes instalações industriais e agro-industriais. Em particular, no distrito de Castelo Branco existem várias empresas que utilizam o “Frio” como parte do seu processo produtivo ou como método de conservação de produtos e que contribuem para o epíteto “Castelo Branco, Capital do Frio”. No presente estudo efectua-se um diagnóstico energético das câmaras frigoríficas com recurso à Termografia por Infravermelhos (TIV)
Insect detection in sticky trap images of tomato crops using machine learning
As climate change, biodiversity loss, and biological invaders are all on the rise, the significance of conservation and pest management initiatives cannot be stressed. Insect traps are frequently
used in projects to discover and monitor insect populations, assign management and conservation
strategies, and assess the effectiveness of treatment. This paper assesses the application of YOLOv5
for detecting insects in yellow sticky traps using images collected from insect traps in Portuguese
tomato plantations, acquired under open field conditions. Furthermore, a sliding window approach
was used to minimize insect detection duplicates in a non-complex way. This article also contributes
to event forecasting in agriculture fields, such as diseases and pests outbreak, by obtaining insect related metrics that can be further analyzed and combined with other data extracted from the crop fields, contributing to smart farming and precision agriculture. The proposed method achieved good results when compared to related works, reaching 94.4% for mAP_0.5, with a precision and recall of 88% and 91%, respectively, using YOLOv5x.info:eu-repo/semantics/publishedVersio
An open and parallel multiresolution framework using block-based adaptive grids
A numerical approach for solving evolutionary partial differential equations
in two and three space dimensions on block-based adaptive grids is presented.
The numerical discretization is based on high-order, central finite-differences
and explicit time integration. Grid refinement and coarsening are triggered by
multiresolution analysis, i.e. thresholding of wavelet coefficients, which
allow controlling the precision of the adaptive approximation of the solution
with respect to uniform grid computations. The implementation of the scheme is
fully parallel using MPI with a hybrid data structure. Load balancing relies on
space filling curves techniques. Validation tests for 2D advection equations
allow to assess the precision and performance of the developed code.
Computations of the compressible Navier-Stokes equations for a temporally
developing 2D mixing layer illustrate the properties of the code for nonlinear
multi-scale problems. The code is open source
Fermentation of high concentrations of lactose to ethanol by engineered flocculent saccharomyces cerevisiae
The development of microorganims that
efficiently ferment lactose has a high biotechnological
interest, particularly for cheese whey bioremediation
processes with simultaneous bio-ethanol production.
The lactose fermentation performance of a recombinant
Saccharomyces cerevisiae flocculent strain was
evaluated. The yeast consumed rapidly and completely
lactose concentrations up to 150 g l-1 in either well- or
micro-aerated batch fermentations. The maximum
ethanol titre was 8% (v/v) and the highest ethanol
productivity was 1.5–2 g l-1 h-1, in micro-aerated
fermentations. The results presented here emphasise
that this strain is an interesting alternative for the
production of ethanol from lactose-based feedstocks.Fundação para a Ciência e a Tecnologia (FCT
Alcoholic fermentation of lactose by engineered flocculent Saccharomyces cerevisiae
The construction of Saccharomyces cerevisiae strains with the ability to ferment lactose has biotechnological interest, particularly for cheese whey fermentation to ethanol. Direct fermentation of whey to ethanol is generally not economically feasible because the low lactose content (ca. 5% w/v) results in low ethanol titre (2 – 3% v/v), making the distillation process too expensive. Concentration of whey lactose (e.g. by ultrafiltration) prior to fermentation is an option to obtain higher ethanol titres. Microbial strains are therefore needed that can efficiently convert high concentrations of lactose into ethanol. We describe here the engineering of a S. cerevisiae strain for efficient lactose fermentation, involving genetic and evolutionary engineering strategies. The evolved strain obtained fermented efficiently lactose concentrations up to 150 g L-1, including 3-fold concentrated cheese whey, producing ethanol titres up to 8% v/v. The strain is highly flocculent, a property that makes it particularly suitable for the development of high cell density fermentation processes
Fermentation of lactose to bio-ethanol by yeasts as part of integrated solutions for the valorisation of cheese whey
Cheese whey, the main dairy by-product, is increasingly recognized as a source of many bioactive valuable compounds. Nevertheless, the most abundant component in whey is lactose (ca. 5% w/v), which represents a significant environmental problem. Due to the large lactose surplus generated, its conversion to bio-ethanol has long been considered as a possible solution for whey bioremediation. In this review, fermentation of lactose to ethanol is discussed, focusing on wild lactose-fermenting yeasts, particularly Kluyveromyces marxianus, and recombinant Saccharomyces cerevisiae strains. The early efforts in the screening and characterization of the fermentation properties of wild lactose-consuming yeasts are reviewed. Furthermore, emphasis is given on the latter advances in engineering S. cerevisiae strains for efficient whey-to-ethanol bioprocesses. Examples of industrial implementation are briefly discussed, illustrating the viability of whey-to-ethanol systems. Current developments on strain engineering together with the growing market for biofuels will likely boost the industrial interest in such processes.Fundação para a Ciência e a Tecnologia (FCT) -
Projecto ProBioethanol PTDC/BIO/66151/2006 ; bolsa
SFRH/BD/13463/2003 and SFRH/BPD/44328/200
Lactose fermentation by recombinant Saccharomyces cerevisiae strains
The development of Saccharomyces cerevisiae strains with the ability to ferment lactose has
a high biotechnological interest, particularly for cheese whey bioremediation processes with
simultaneous bio-ethanol production. We have developed a flocculent S. cerevisiae strain
that efficiently ferments lactose to ethanol, using a combination of genetic engineering and
evolutionary engineering approaches. This strain fermented efficiently and nearly completely
(residual lactose < 3 g·L -1) lactose concentrations up to 150 g·L-1, including 3-fold
concentrated cheese whey, producing ethanol titres up to 8% (v/v). The ethanol productivity
obtained with this strain (> 1.5 g·L -1·h-1) was higher than that reported for batch or fed-batch
fermentations with other lactose-consuming recombinant S. cerevisiae strains. The strain is
highly flocculent, a property that makes it interesting for the development of high cell density
fermentation processes, which may attain much higher productivity
Study of Metal/Polymer Interface of Parts Produced by a Hybrid Additive Manufacturing Approach
Acknowledgments
This research work was supported by the Portuguese Foundation for Science and Technology (FCT) and Centro2020 through the Project reference: UID/Multi/04044/2013, PAMI - ROTEIRO/0328/2013 (Nº 022158) and Portuguese National Innovation Agency (ANI) through the Project reference POCI-01-0247-FEDER-017963, NEXT.parts – Next Generation of Advanced Hybrid Parts (co-promotion nº 17963).The additive manufacturing of multimaterial parts, e.g. metal/plastic, with functional
gradients represents for current market demands a great potential of applications [1]. Metal Polymer parts combine the good mechanical properties of the metals with the low weight characteristics, good impact strength, good vibration and sound absorption of the polymers. Nevertheless, the coupling between metal and polymers is a great challenge since the processing factors for each one of them are very different. In addition, a system that makes the hybrid processing - metal/polymer - using
only one operation is unknown [2, 3]. To overcome this drawback, a hybrid additive manufacturing system based on the additive technologies of SLM and SL was recently developed by the authors. The SLM and SL techniques joined enabling the production of a photopolymerization of the polymer in the voids of a 3D metal mesh previously produced by SLM [4]. The purpose of this work is the study on the metal/polymer interface of hybrid parts manufactured from the hybrid additive manufacturing system [5]. For this, a core of tool steel (H13) and two different types of photopolymers:
one elastomeric (BR3D-DL-Flex) and another one rigid (BR3D-DL-Hard) are considered. A set of six samples for each one of metal core/polymer combination was manufactured and submitted to tensile tests.info:eu-repo/semantics/publishedVersio
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