912 research outputs found
Texture changes during chilled storage of wild and farmed blacspot seabream (Pagellus bogaraveo) fed different diets
The impact of changes in dietary lipids and protein sources on texture was evaluated
on farmed blackspot seabream (Pagellus bogaraveo) throughout 14 days of ice storage
and compared with wild fish. A commercial diet formulated with a high proportion of
lipids, and two diets formulated with an important reduction of lipid levels by 60%
and adding either plant protein sources (LL diet) or fishmeal (LL + diet) were supplied
during growth until commercial size was attained. In the wild fish, the raw fillet hardness
was significantly higher than in farmed fish during the entire ice-storage
period.
In the farmed fish, an increase of muscle lipid accumulation and change of fiber density
were responsible for the variations in texture in the raw fillet. The highest reduction
was found in fish fed with diets LL+ and LL. The texture parameters studied on
the cooked fillets showed no significant differences, neither attributable to the diets
nor to the ice-storage
period.JUNTA ASESORA DE CULTIVOS MARINOS (JACUMAR)Postprin
On a thermodynamically consistent modification of the Becker-Doering equations
Recently, Dreyer and Duderstadt have proposed a modification of the
Becker--Doering cluster equations which now have a nonconvex Lyapunov function.
We start with existence and uniqueness results for the modified equations. Next
we derive an explicit criterion for the existence of equilibrium states and
solve the minimization problem for the Lyapunov function. Finally, we discuss
the long time behavior in the case that equilibrium solutions do exist
Anaerobic digestion of whole-crop winter wheat silage for renewable energy production
With biogas production expanding across Europe in response to renewable energy incentives, a wider variety of crops need to be considered as feedstock. Maize, the most commonly used crop at present, is not ideal in cooler, wetter regions, where higher energy yields per hectare might be achieved with other cereals. Winter wheat is a possible candidate because, under these conditions, it has a good biomass yield, can be ensiled, and can be used as a whole crop material. The results showed that, when harvested at the medium milk stage, the specific methane yield was 0.32 m3 CH4 kg–1 volatile solids added, equal to 73% of the measured calorific value. Using crop yield values for the north of England, a net energy yield of 146–155 GJ ha–1 year–1 could be achieved after taking into account both direct and indirect energy consumption in cultivation, processing through anaerobic digestion, and spreading digestate back to the land. The process showed some limitations, however: the relatively low density of the substrate made it difficult to mix the digester, and there was a buildup of soluble chemical oxygen demand, which represented a loss in methane potential and may also have led to biofoaming. The high nitrogen content of the wheat initially caused problems, but these could be overcome by acclimatization. A combination of these factors is likely to limit the loading that can be applied to the digester when using winter wheat as a substrat
Characterization of ionic nature of biosurfactant extracted from corn steep liquor using ionic exchange resins
[Excerpt] Resins have been used for years for the purification and characterization of ionic substances. The use of these resins allows not only remove impurities or increase the concentration of metabolites from industrial streams, but also allows define their ionic structure. In general, surfactants can be classified as non-ionic, anionic, cationic or amphoteric, what is going to define their future application at industrial scale. For example, anionic surfactants present the greatest wetting and emulsifying properties, while cationic ones have excellent antibacterial properties as well as good emulsifier capacities. Otherwise, amphoteric surfactants, which may have anionic or cationic properties depending on pH, are widely used in personal care products because of their less irritability to skin and eyes in comparison with other types of surfactants. [...]Spanish Ministry of Economy and Competitiveness (FEDER funds under the project CTM2015-68904)University of Vigo (Spain
Potential applications of biosurfactant extract obtained from corn steep liquor in hair formulations
[Excerpt] Biosurfactants (BS) have great advantages as an eco-friendly alternative to synthetic surfactants used in hair formulations. Human hair contains fatty acids (palmitic, palmitoleic, oleic and stearic acid) that prevent hair dryness and avoid the lower scalp hair density. These fatty acids are included in the composition of biosurfactant extract obtained from corn steep liquor (CSL) (Vecino et al., 2015). The adsorption of surfactants on hair depends on its ionic charge. Normally, hair surface has a negative charge, so it adsorbs cationic surfactants. For this reason, hair conditioners and also hair sunscreens contain cationic surfactants, mainly quaternary ammonium salts, which absorb UV light, protecting hair surface from dryness and oxidation. Contrarily, shampoo formulations are composed by anionic surface-active agents, which can induce, in many cases, hair protein loss, hair dryness, opacity and difficulty of handling. In order to know if biosurfactant extract, obtained from CSL, could be adsorbed on hair, its ionic behavior was evaluated by using anionic and cationic resins using a solid/liquid ratio of 1:10 at room temperature. After that, adsorption experiments using human hair were established at room temperature with hair/biosurfactant solution ratio of 1:50. [...]The financial support from the Spanish Ministry of Economy and Competitiveness
(FEDER funds under the project CTM2015-68904) and L. Rodríguez-López is grateful
for her predoctoral fellowship supported by the University of Vigo (Spain)
Adsorption capacity evaluation of a lipopeptide biosurfactant on human hair
[Excerpt] Nowadays, surfactants are used in a wide variety of applications in several fields, such as cosmetic and health care, environmental issues and, generally, as detergents. They present valuable characteristics since they can decrease water surface tension and solubilize molecules that cannot be eliminated in an aqueous media in normal conditions. Due to their surface active nature, synthetic surfactants can result toxic in the media in which they are applied. These drawbacks can be overcome by using biosurfactants, since they result environmentally friendly because of their biodegradability and low toxicity. Therefore, it would be interesting to replace synthetic detergents by biosurfactants in cosmetic and personal care formulations. From this point of view, Vecino et al., [1] have extracted biosurfactants from an industrial stream of corn wet milling industry, consisting of a lipopeptide that could have important applications in the formulation of natural shampoos. This biosurfactant is able to reduce the surface tension of water in more than 30 units. Thus, the aim of this work was to study the adsorption of this biosurfactant in human hair. [...]Spanish Ministry of Economy and Competitiveness (FEDER funds under the project
CTM2015-68904University of Vigo (Spain
Susceptibility of Sphenarium purpurascens purpurascens (Orthoptera: Pyrgomorphidae) instars to a commercial strain of Metarhizium acridum (Hypocreales: Clavicipitaceae) in Michoacan, Mexico.
The objective of this study was to evaluate the performance of a commercial strain of the entomopathogenic fungi Metarhizium acridum, on the different instars of the grasshopper pest Sphenarium purpurascens purpurascens, as well as its sporulation via bioassays under laboratory conditions, in Michoacan, Mexico. The most susceptible instars were nymphs one, two and four, with an average survival time of less than 6.91 days. The least susceptible was the adult, with a survival time of 8.36 days. The instars with the highest post mortem sporulation were nymphs one, two and three. A moderate negative association was registered between S. p. purpurascens and the sporulation of M. acridum, in advanced instars (nymph 4 and adult), in which sporulation was lower compared to early instars. All instars showed survival rates below 5 %, so M. acridum can be considered to be a viable option for controlling this pest in the field
Design of an AS/RS machine for storage and extraction of items in a warehouse using Finite Element Analysis (FEA)
The globalization of markets and high competitiveness impose new challenges every day on companies that develop their activities in the field of logistics, e-commerce, service, and product distribution. The implementation of automated systems becomes relevant when the objective is to increase productivity, efficiency and reduce costs associated with handling, picking and overhead. The AS / RS systems (i.e., Automated Storage and Retrieval System) are automated machines able to move in the 3 coordinate axes (x, y, z), which are responsible for arranging the items in large warehouses generating a decrease in time delivery and storage.
The aim of the article is to show the design of a prototype of an AS / RS (CAD) machine based on Finite Element Analysis (FEA) to verify the behavior before static loads according to Von Misses criteria and to guarantee the appropriate administration, storage, and extraction of each item in the warehouse, respectively. Also, it shows the use of the selection matrix that facilitates the interaction with the articles and execute the primary functions according to customer requirements. The result of this research shows the advantages and disadvantages of the implementation of these systems for companies that manage high volumes of storage, limited physical space and that require an appropriate management of the elements through the help of an easy-to-implement human-machine interface (HMI) that has control over open loop
Experimentally Quantifying the Advantages of Weak-Value-Based Metrology
We experimentally investigate the relative advantages of implementing weak-value-based metrology versus standard methods. While the techniques outlined herein apply more generally, we measure small optical beam deflections both using a Sagnac interferometer with a monitored dark port (the weak-value-based technique), and by focusing the entire beam to a split detector (the standard technique). By introducing controlled external transverse detector modulations and transverse beam deflection momentum modulations, we quantify the mitigation of these sources in the weak-value-based experiment versus the standard focusing experiment. The experiments are compared using a combination of deterministic and stochastic methods. In all cases, the weak-value technique performs the same or better than the standard technique by up to two orders of magnitude in precision for our parameters. We further measure the statistical efficiency of the weak-value-based technique. By postselecting on 1% of the photons, we obtain 99% of the available Fisher information of the beam deflection parameter
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