Edible film based on candelilla wax to improve the shelf life and quality of avocado

In this study the effect of addition of ellagic acid (at three different concentrations) into candelilla wax matrix on shelf life and quality of whole avocados was studied. Control treatments were avocados coated with candelilla wax without ellagic acid and avocados without coating. The fruits were chosen for their maturity, size, free from infection and physical defects. All those samples were inoculated with a concentrated suspension of spores of Colletotrichum gloeosporioides, the main phytopathogenic fungus for avocados. Experiments were carried out completely divided into randomized groups. Changes in appearance, solids content, pH, a_w, lightness (L¹ value) and weight loss were monitored during 6 weeks every 8 days. A sensory evaluation of avocados coated with the best edible film was also performed. Edibel films were able to reduce significantly the damage caused by C. gloeosporioides, reducing also significantly the change in appearance and weight loss in the fruits. Use of ellagic acid as part of the edible film has an important effect to improve the quality and shelf life of avocado. With this work we found that using this new protection system the negative effects of C. gloeosporioides can be successfully reduced.     

Effects of neonatal handling on playfulness by means of reversal of the desire to play in rats (Rattus norvegicus).

In the present study the authors sought to establish whether the range of effects of neonatal handling stimulation (H), that is, brief daily periods of infant isolation, could be extended to the domain of social motivation. With this aim, the authors studied the innate motivation to engage in rough-and-tumble play (R&T) in adolescent rats (Rattus norvegicus) by means of a reversal design, in which half of the rats were first housed in isolation (Days 1–3), and then in company (Days 4–6), while the other half followed the reverse sequence of housing conditions. Results showed in a clear-cut manner that H fuelled playfulness, as measured by pin and dorsal contact episodes, with (relative) independence of trait-based differences in fearful behavior between handled and nonhandled rats. Given that the different levels of the rat’s social brain are apparently sensitive to tactile stimulation in infancy, the authors propose that the vibrant R&T reported here could reflect an enduring alteration of genetically based, motivational systems underlying playfulness and, perhaps, positive social emotions like joy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Iron oxide coating films in soda-lime glass by triboadhesion

In the triboadhesion process the coating material is passed through a rotating cotton mop and the substrate to be coated. The cotton mop rotates at high velocity and exerts pressure on the surface of the substrate. The combined effect of pressure and velocity of the coating mop on the substrate increases its temperature close to the melting point, allowing deposition and diffusion of the coating material within the substrate. After it is deposited, its particles are embedded within the base material forming a thin film composite. The amount of the coating material deposited on the substrate has its maximum at the surface and then decreases as a function of the local temperature within the base material. Bearing this in mind, in the present work, triboadhesion is employed to deposit iron oxide in a substrate of soda-lime glass, with the purpose of determining the feasibility of using this technique for solar control coatings. It was found, through electronic scan microscopy, that a composite material film is formed following the coating direction. Reflectance and transmittance tests were carried out on the glass samples. A 20% difference was found in the visible spectral region (VIS), and a reduction between 10 and 20% in the Near Infrared Region (NIR). These results showed that the triboadhesion is a promising technique for the application of thin films for solar control or solar cells. This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim J. O Aguilar received a B.S. degree in Mechanical Engineering from ITCM in 1995. He then went on to receive his M.S degree from Cenidet and his Ph. Degree from UNAM, in 1999 and 2005 respectively. Dr. Aguilar is currently a Professor at the Science and Engineering Division at Universidad de Quintana Roo, Chetumal, Quintana Roo, México. Dr. Aguilar’s research interests are in the area of solar control coatings and solar concentrating collectors. J. M. Rodríguez-Lelis received a B.S. degree in Mechanical Engineering from ESIME (IPN) in 1984. He then went on to receive his M.S. and Ph.D. degrees from Birmingham University (U.K.) in 1988 and 1992, respectively. Dr. Rodríguez-Lelis is currently a Professor at the Mechanical Engineering Department at Cenidet in Cuernavaca, Morelos, México. Dr. Rodríguez-Lelis’s research interests are in the area of tribology, surface enhancement by triboadhesión, turbomachinery and biomechanics. M. J. Arjona received a B.S. degree in Energy Systems Engineering from Universidad de Quintana Roo in 2002. He then went on to receive his M.S. degree from Cenidet in 2005. M.S. Arjona is currently a Professor at Universidad de la Ciénega de Michoacán, Sahuayo, Michoacan. M.S. Arjona’s research interests are in the area of renewable energy     

Milk urea nitrogen variation explained by differences in urea transport into the gastrointestinal tract in lactating dairy cows

Milk urea nitrogen (MUN) and blood urea nitrogen are correlated with nitrogen balance and nitrogen excretion; however, there is also a genetic component to MUN concentrations that could be associated with differences in urea transport. It was hypothesized that a portion of the variation in MUN concentrations among cows is caused by variation in gastrointestinal and kidney urea clearance rates. Eight lactating cows with varying MUN concentrations while fed a common diet were infused with [¹⁵N¹⁵N]urea to determine urea N entry rate (UER), gastrointestinal entry rate, returned to ornithine cycle, urea N used for anabolism, urea N excretion in feces and urine. Urea clearance rates by the kidneys and gastrointestinal tract were calculated from isotopic enrichment of urea excretion in urine and gut entry rate, respectively, and plasma urea N concentrations (PUN). Over the course of the experiment, animals weighed an average of 506 ± 62 kg and produced 26.3 ± 4.39 kg of milk/d, with MUN concentrations ranging from 11.6 to 17.3 mg/dL (average of 14.9 ± 2.1 mg/dL). Plasma urea N was positively correlated with UER, urea N excretion in urine, and urea N used for anabolism. Plasma urea N and MUN were negatively correlated with gut clearance rates and ratio of gastrointestinal entry rate to UER. This relationship supports the hypothesis that differences in gut urea transport activity among animals causes variation in PUN and MUN concentrations, and that cows with high PUN and MUN are less efficient at recycling PUN to the gastrointestinal tract and thus may be more susceptible to ruminal N deficiencies when fed low RDP diets. Such biological variation in urea metabolism necessitates an adequate safety margin when setting regulations for maximal MUN levels as an indicator of herd N efficiency.     

UWB MIMO antenna implemented with orthogonal quasi‐circular slot dipole radiators

In this paper, a very low‐profile two‐port ultra‐wideband antenna for multiple input‐multiple output applications is proposed. The antenna is implemented by using two orthogonal quasi‐circular slot dipole radiators fed by coaxial lines. The antenna performs from 2 to 10 GHz, with an average peak‐gain of 4 dB, and high port isolation, with values around S₂₁ = ?20 dB and below. The radiation patterns of both antennas are opposite to each other and hence, the diversity gain reaches values around 20 dB. The low inter‐port coupling and low correlation are verified by obtaining the envelope correlation coefficient, which is lower than 0.003. These calculations were made by the S‐parameter and far‐field methods. The total active reflection coefficient shows that the antenna operative bandwidth does not change for different input signals with random phases, preserving the operation from 2 to 10 GHz. The antenna performance is compared to different state of the art slot configurations, showing advantages to previously published work.     

Automotive Post-Collision Control Software System: Requirements and Verification

Programming and Computer Software - There are different types of automotive safety systems focused on crash events. These types could be classified as pre-collision, during-collision, and...     

A new estimation method of irradiance on a partially shaded PV generator in grid-connected photovoltaic systems

A new method for estimating the irradiance on a partially shaded photovoltaic generator system is proposed. The basic principle of this method consists of two parts: firstly, an approximation of the obstacles’ outline or the local horizon by a set of linear functions. Here, a survey of the surroundings is based on the reading of the topographic coordinates of the only significant points of all the objects surrounding the photovoltaic generator. Secondly, the irradiance on the photovoltaic plane is estimated using an accurate model such as the Perez et al. model and assuming that the shading affects both the direct radiation and a part of the diffuse component (circumsolar component).The aim of this paper is to present the principles of the proposed method and the algorithm used for calculating the irradiance on shaded planes. In addition, the results of the comparison between the simulated and measured values of this method are presented.     

In vitro chromium availability in breakfast cereals

Chromium (Cr) availability (expressed as percentage dialysed Cr) in breakfast cereals (n = 93) was evaluated by an in vitro method of simulated human gastrointestinal digestion followed by GFAAS measurement of dialysed Cr. The dialysed Cr ranged from 0.48 ± 0.07 to 3.26 ± 0.04%. The Cr dialysability was independent of the total amount of this mineral in the breakfast cereals. Correlations between chromium and other breakfast cereal components (lipids, carbohydrates, minerals, vitamins) were also studied. The dialysed Cr values were significantly correlated with the total and unsaturated lipids (p < 0.005). Such other food components as starch, sucrose, fibre, proteins, and various micronutrients were not significantly correlated with the dialysable Cr.