1,390 research outputs found
Generalized Chaplygin gas with and the cosmological model
The generalized Chaplygin gas model is characterized by the equation of state
. It is generally stated that the case is equivalent to a model with cosmological constant and dust (). In this work we show that, if this is true for the background equations,
this is not true for the perturbation equations. Hence, the mass spectrum
predicted for both models may differ.Comment: Latex file, 4 pages, 2 figures in eps forma
Catches in ghost-fishing octopus and fish traps in the northeastern Atlantic Ocean (Algarve, Portugal)
Ghost fishing is the term used to describe the continued capture of fish and other living organisms after a
fisherman has lost all control over the gear. Traps may be lost for a variety of reasons including theft, vandalism,
abandonment, interactions with other gear, fouling on the bottom (i.e., traps and ropes are caught on rocky substrate), bad weather, and human error (Laist, 1995). Annual trap loss can be as high as 20% to 50% of fished traps in some fisheries (Al-Masroori et al., 2004). Because lost traps can continue to fish for long periods, albeit
with decreasing efficiency over time (e.g., Smolowitz, 1978; Breen, 1987, 1990; Guillory, 1993), ghost fishing is
a concern in fisheries worldwide
HIV-2 viral production and infectivity are affected by APO3 host factors
Poster presented at the 7th Postgraduate iMed.ULisboa Students Meeting. Faculty of Pharmacy, Universidade de Lisboa, 15-16 July 2015.Egas Moniz - Cooperativa de Ensino Superior CRL and Fundação para a CiĂȘncia e Tecnologia, Lisbon, Portuga
APOBEC3 host factors modulate viral production and infectivity of HIV-2
Poster presented at the 15th European AIDS Conference/EACS. Barcelona, 21-24 October 2015.This work was funded by FCT â SFRH/BD/81921/2011 and Egas Moniz, Cooperativa de Ensino Superior, CRL,
Portugal
Life cycle energy and carbon analysis of a road-safety barrier produced using recycled tire rubber
Increasing end-of-life material recovery and its application in new products is essential to reduce resource consumption. This paper assesses the cradle-to-gate life cycle energy and carbon dioxide (CO2) emissions of a new road safety barrier product to be installed around guardrailsâ poles. To analyze the potential life cycle benefit of incorporating recycled materials, a base case product A, produced with conventional virgin synthetic rubber and polypropylene (PP), was compared with two equivalent alternatives under study: B (using recycled end-of-life tire rubber granulate (TRG) and PP), and C (using TRG and recycled polypropylene). The results show that the incorporation of recycled TRG has a positive effect in primary energy and carbon emissions. Product B presents less 38% CO2 emissions and 47% non-renewable primary energy than product A. The combination of TRG and recycled polypropylene (C), presents even more benefits: less 69% CO2 and 86% nonrenewable primary energy than A. Supply chain processes and material production have much higher impacts than the product manufacturing (e.g. product molding only represents 5% of the primary energy of product A). To conclude, recycled materials incorporation should be strongly encouraged since it has a great potential to reduce current carbon emissions and primary energy of products.This research was funded by: European Unionâs Horizon 2020 research and innovation programme under grant
agreement âNo. 810764â; FEDER, through the Portugal-2020 program (PT2020) by the Regional Operational
Program of Lisbon (LISBOA-01-0247-FEDER-038326) - project n⊠038326 â âSafety4Road â Application of hybrid
ecological materials to improve road safetyâ; project Base Funding â UIDB/04730/2020 of the Center for Innovation
in Engineering and Industrial Technology â CIETI, Portugal; LA/P/0045/2020 (ALiCE) and UIDB/00511/2020 -
UIDP/00511/2020 (LEPABE) funded by national funds through FCT/MCTES (PIDDAC).info:eu-repo/semantics/publishedVersio
Chemical composition of different oregano (origanum vulgare l.) essential oils: relevance for the activity against foodborne and spoilage bacteria
Herbs and spices have been used for centuries in culinary
for seasoning and flavouring purposes. More recently, there has
been a growing interest regarding the use of some plants and its
essential oils (EO) for their activity against foodborne pathogens
and foodspoilage bacteria. Due to its potential in extending the
self-life of foods and its better acceptability by consumers who
demand more ânaturalâ foods, the use of EO can be an interesting
alternative to substitute, at least partially, synthetic preservatives
Experimental and numerical study to minimize the residual stresses in welding of 6082-T6 aluminum alloy
One of the most important negative consequence in the fusion welding processes is the generation of tensile residual stresses in welded joints. The main goals of this work are to determine the optimal combination of welding parameters to minimize the residual stress level and the influence of each welding parameter in that feature to weld 6082-T6 aluminum alloy plates using the GMAW welding process. To achieve these goals was implemented the Taguchi orthogonal array (L27) to define the design of numerical and experimental tests. All combinations were simulated in the Simufactwelding 6.0 software, from which it was possible to obtain the values of maximum residual stresses. The data treatment was carried out, reaching the combination of levels for each parameter. With ANOVA analysis was found that the parameter with the greatest influence in the residual stress generation was the welding speed, while the parameter with the least influence was the torch angle. Also, to minimize the residual stresses it was observed that the optimal combination of welding parameters is welding current intensity of 202 A, welding speed of 10 mm/s, and 30° of inclination of the angular torch. The two simulations that resulted in the highest and lowest residual stresses were validated experimentally by the hole drilling method to measure the residual stresses.info:eu-repo/semantics/publishedVersio
Catch composition, catch rates and size selectivity of three long-line methods in the Algarve (southern Portugal)
Three long-line methods have been studied in the Algarve: 1) small-hook long-line for inshore (less than 30 m) âwhiteâ sea breams (Sparidae); 2) small-hook long-line for deeper water (40-60 m) âredâ sea breams; and 3) deep water (500-700 m) semi-pelagic long-line for hake Merluccius merluccius
(Linnaeus, 1758). Selectivity studies were carried out with three hook sizes in the first two cases: Mustad round-bent Quality 2369 hooks, numbers 15, 13, and 11, baited with a standardsized razor-shell Ensis siliqua (Linnaeus, 1758). Four hook sizes (numbers 10, 9, 7, and 5) of Stell round-bent, eyed hooks were used in the semi-pelagic long-line selectivity study, baited with a half of a standard-sized sardine. Some factors affecting catch composition and catch rates of the small
hook long-lines were also evaluated: bait, gangion length, setting time, fishing ground, and depth. Species diversity was relatively high, with 40, 36 and 27 species, respectively, in the three studies. However, the catches were dominated by a limited number of species. Catch rates (number
of fish per 100 hooks) were variable ( 20 %), with a general decrease in catch rate with increasing hook size in all the studies. In general, the catch size distributions for the different hook sizes for each species were highly overlapping, with little or no evidence of differences in
size selectivity. Hooks caught a wide size-range for each species, with few or no illegal-sized fish, in most cases. Some implications of these results for the management of multi-species, multi-gear fisheries are discussed.info:eu-repo/semantics/publishedVersio
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