Surface Modification of Natural Rubber by Sulfur hexafluoride (SF6) Plasma Treatment: A New Approach to Improve Mechanical and Hydrophobic Properties

Plasma treatments have faced growing interest as important strategy to modify the hydrophobic/hydrophilic characteristics of materials. However, challenges related to the plasma modification of polymers are the improvement of the chemical resistance without decreasing the mechanical resistance. In this letter, we present for the first time a plasma treatment, using Sulfur hexafluoride (SF6), analogous to vulcanization process, of natural rubber surface, which resulted in a chemical and tension resistance improvements. The natural rubber membranes were coated with glow discharge plasmas generated in sulfur hexafluoride (SF6) atmospheres at a total pressure of 160 mTorr and applying 70 W of radiofrequency. Plasma treatment increases the contact angles from 64° to 125° i.e. leading to a hydrophobic surface. The tension at rupture increased from 3.7 to 6.1 MPa compared to natural rubber without plasma treatment demonstrated by stress-strain investigation. These results provide a fast alternative approach to improve mechanical and chemical properties of rubber-based products

Use of analysis and processing of digital images for evaluation and control of animal behavior in hot climates

The world production of meats is mainly concentrated in the countries with a hot climate. Among these countries, Brazil, considered "world's breadbasket", is located in the intertropical zone, with hot climates and presents lower thermal amplitude. Brazilian poultry is a leader in the production and export of broilers. Brazil has the second largest cattle herd in the world, has the largest commercial herd besides being the largest exporter of beef. Brazilian swine breeding, among the most advanced production chains in the world, occupy the position of fourth largest producer of pork in the world. Projections for Brazil's meat production sector indicate strong growth in the coming years, with countries in hot climates that will continue to sustain future growth in world meat production, ensuring food security in many countries. One of the factors responsible for the success or failure of animal production is the environment, defined by the sum of all physical and biological factors that affect animals. In these regions of hot climates, climatic factors are among the main limiting factors to the development of animal production, which may compromise animal welfare and productivity indices. Behavioral information can aid in the analysis of problems arising from environmental conditions unfavorable to animals, helping both decision making and the use of different environmental conditioning systems. The introduction of technification in the animal behavior evaluation processes, through the use of video cameras and image processing programs, allowed a better interpretation of the behavioral responses, quickly, accurately and non-invasively, gradually being used with greater frequency in the animal production sectors. The study of animal behavior assumes an important role in animal production, since, to rationalize the breeding methods, management, feeding and facilities techniques have been developed that interfere with animal behavior. In this context, the use of digital image analysis techniques, where the animals themselves are used as biosensors in response to environmental conditions, contributes to the analysis of animal behavior, and consequently also to the assessment of the internal environment of the production in hot weather. Keywords: animal production, animal welfare, information technolog

Potential for Ammonia Generation and Emission in Broiler Production Facilities in Brazil

Air quality is one of the main factors that must be guaranteed in animal production. However, the measurement of pollutants is still a problem in several countries because the available methods are costly and do not always apply to the reality of the constructive typology adopted, as in ountries with a hot climate, which adopt predominantly open facilities. Thus, the objective of the present study was to develop predictive models for the potential generation and emission of ammonia in the production of broiler chickens with different types of litter, different reuse cycles and under different climatic conditions. Samples of poultry litter from thirty commercial aviaries submitted to different air temperatures were analyzed. The experiment was conducted and analyzed in a completely randomized design, following a factorial scheme. Models were developed to predict the potential for generation and emission of ammonia, which can be applied in facilities with ambient conditions of air temperature between 25 and 40 °C and with wood shaving bed with up to four reuse cycles and coffee husks bed with up to six reuse cycles. The developed and validated models showed high accuracy indicating that they can be used to estimate the potential for ammonia generation and emission

Design Specifications for an Auxiliary Incision Retractor in Dacryocystorhinostomy Surgeries

It is presented the design specifications for a Retractor Robotic System (RRS) based on the surgical necessities in the incisions procedure for a dacryocystorhinostomy. The specifications are conformed by a mathematical model, the experimental data measured, a modular flexible architecture, energy supplier system, the mechanical group, and the safety system. The specifications suggest that the use of flexible polymeric materials for the RRS provide a mayor adaptability of the system with the biological tissue; so a pneumatic actuator could be a suitable option.This research was funded by CONACYT (Consejo Nacional de Ciencia y Tecnología) Grant No. 86356

Striped antiferromagnetic order and electronic properties of stoichiometric LiFeAs from first-principles calculations

We investigate the structural, electronic, and magnetic properties of stoichiometric LiFeAs by using state-of-the-arts first-principles method. We find the magnetic ground-state by comparing the total energies among all the possible magnetic orders. Our calculated internal positions of Li and As are in good agreement with experiment. Our results show that stoichiometric LiFeAs has almost the same striped antiferromagnetic spin order as other FeAs-based parent compounds and tetragonal FeSe do, and the experimental fact that no magnetic phase transition has been observed at finite temperature is attributed to the tiny inter-layer spin coupling

Preliminary Development Plan Of The Alr, The Laser Rangefinder For The Aster Deep Space Mission To The 2001 Sn263 Asteroid

The Brazilian deep space mission ASTER, as temporarily named, plans to send a small spacecraft to encounter and investigate the triple asteroid 2001-SN263. The launch is scheduled (initially) to occur in 2015, arriving in 2018. The main motivation of the mission is the development of technology and expertise to leverage the national space sector. Within the scientific goals, the investigation of the still unknown asteroid 2001-SN263. The main project guideline is to aggregate the widest possible Brazilian involvement in the platform, the development and operation of subsystems, integration, payload, as well as in the tracking, navigation, guidance and control of the probe. To meet this guideline, among others, the decision for the development of a laser altimeter in Brazil to fly in the mission was taken. This effort is currently coordinated by a group of researchers from the aerospace engineering personnel of UFABC. This article presents the preliminary development plan for the design of this instrument, which was called ALR (ASTER Laser Rangefinder).33331338Araujo, R.A.N., Winter, O.C., Prado, A.F.B., De, A., Sukhanov, A., (2010) O Sistema Triplo De Asteróides 2001SN263: Dinâmica Orbital E Regiões De Estabilidade, , Trabalho apresentado no XV Colóquio Brasileiro de Dinâmica Orbital, Hotel Alpina, Teresópolis, RJ, BrasilBecker, T., Howell, E.S., Nolan, M.C., Magri, C., Physical Modeling of Triple Near-Earth Asteroid 153591(2001 SN263) (2008) American Astronomical Society, DPS Meeting #40, #28.06, 40, p. 437. , Bulletin of the American Astronomical SocietyCole, T.D., NEAR Laser Rangefinder: A tool for the mapping and topologic study of Asteroid 433 Eros (1998) JHU/APL Tech. Dig., 19 (2), pp. 142-157Hashimoto, T., Kubota, T., Mizuno, T., Light weight sensors for the autonomous asteroid landing of MUSES-C mission (2003) Acta Astronautica, 52 (2-6), pp. 381-388Nolan, M.C., Howell, E.S., Benner, L.A.M., Ostro, S.J., Giorgini, J.D., Magri, C., Margot, J., Shepard, M., Planetary Radar Imaging of Binary Asteroids (2008) Presentation in the Binary Asteroid Dynamics Workshop, , http://www.asu.cas.cz/~asteroid/paris/add-ons.htm, Observatory Meudon, Paris, France, fromReddy, V., Gaffey, M.J., Schaal, M., Takir, D., Physical Characterization of First Triplet Near-Earth Asteroid (153591) 2001 SN263 (2008) Asteroids, Comets, Meteors, , 2008 held July 14-18, In Baltimore, Maryland. LPI Contribution No. 1405, paper id. 8244Sukhanov, A.A., de Velho, H.F.C., Macau, E.E., Winter, O.C., The Aster project: Flight to a near-Earth asteroid (2010) Cosmic Research, 48 (5), pp. 443-450. , doi:10.1134/S0010952510050114Tsuno, K., Okumura, E., Katsuyama, Y., Mizuno, T., Hashimoto, T., Nakayama, M., Hashimoto, H., Lidar on board asteroid explorer Hayabusa (2006) Proc. 6th Internat. Conf. On Space Optics, , ESTEC, Noordwijk, The Netherlands (ESA SP-621, JuneWinter, O.C., de Araujo, R.A.N., de Prado, A.F.B.A., Sukhanov, A., A Study of the orbital dynamics of the asteroid 2001 SN263 (2010) Proceedings of the 9th Brazilian Conference on Dynamics Control and Their Applications. Serra Negra, SP, , http://www.sbmac.org.br/dincon/trabalhos/PDF/minisymposia/68649.pdf, ISSN 2178-3667, fro

A Model for the Development of the Rhizobial and Arbuscular Mycorrhizal Symbioses in Legumes and Its Use to Understand the Roles of Ethylene in the Establishment of these two Symbioses

We propose a model depicting the development of nodulation and arbuscular mycorrhizae. Both processes are dissected into many steps, using Pisum sativum L. nodulation mutants as a guideline. For nodulation, we distinguish two main developmental programs, one epidermal and one cortical. Whereas Nod factors alone affect the cortical program, bacteria are required to trigger the epidermal events. We propose that the two programs of the rhizobial symbiosis evolved separately and that, over time, they came to function together. The distinction between these two programs does not exist for arbuscular mycorrhizae development despite events occurring in both root tissues. Mutations that affect both symbioses are restricted to the epidermal program. We propose here sites of action and potential roles for ethylene during the formation of the two symbioses with a specific hypothesis for nodule organogenesis. Assuming the epidermis does not make ethylene, the microsymbionts probably first encounter a regulatory level of ethylene at the epidermis–outermost cortical cell layer interface. Depending on the hormone concentrations there, infection will either progress or be blocked. In the former case, ethylene affects the cortex cytoskeleton, allowing reorganization that facilitates infection; in the latter case, ethylene acts on several enzymes that interfere with infection thread growth, causing it to abort. Throughout this review, the difficulty of generalizing the roles of ethylene is emphasized and numerous examples are given to demonstrate the diversity that exists in plants

Distinctive waves of innate immune response in the retina in experimental autoimmune encephalomyelitis

Neurodegeneration mediates neurological disability in inflammatory demyelinating diseases of the CNS. The role of innate immune cells in mediating this damage has remained controversial with evidence for destructive and protective effects. This has complicated efforts to develop treatment. The time sequence and dynamic evolution of the opposing functions are especially unclear. Given limits of in vivo monitoring in human diseases such as multiple sclerosis (MS), animal models are warranted to investigate the association and timing of innate immune activation with neurodegeneration. Using noninvasive in vivo retinal imaging of experimental autoimmune encephalitis (EAE) in CX3CR1(GFP/+)-knock-in mice followed by transcriptional profiling, we are able to show 2 distinct waves separated by a marked reduction in the number of innate immune cells and change in cell morphology. The first wave is characterized by an inflammatory phagocytic phenotype preceding the onset of EAE, whereas the second wave is characterized by a regulatory, antiinflammatory phenotype during the chronic stage. Additionally, the magnitude of the first wave is associated with neuronal loss. Two transcripts identified - growth arrest-specific protein 6 (GAS6) and suppressor of cytokine signaling 3 (SOCS3) - might be promising targets for enhancing protective effects of microglia in the chronic phase after initial injury

Measurement of the W+W-gamma Cross Section and Direct Limits on Anomalous Quartic Gauge Boson Couplings at LEP

The process e+e- -> W+W-gamma is analysed using the data collected with the L3 detector at LEP at a centre-of-mass energy of 188.6GeV, corresponding to an integrated luminosity of 176.8pb^-1. Based on a sample of 42 selected W+W- candidates containing an isolated hard photon, the W+W-gamma cross section, defined within phase-space cuts, is measured to be: sigma_WWgamma = 290 +/- 80 +/- 16 fb, consistent with the Standard Model expectation. Including the process e+e- -> nu nu gamma gamma, limits are derived on anomalous contributions to the Standard Model quartic vertices W+W- gamma gamma and W+W-Z gamma at 95% CL: -0.043 GeV^-2 < a_0/Lambda^2 < 0.043 GeV^-2 0.08 GeV^-2 < a_c/Lambda^2 < 0.13 GeV^-2 0.41 GeV^-2 < a_n/Lambda^2 < 0.37 GeV^-2

Production of Single W Bosons at \sqrt{s}=189 GeV and Measurement of WWgamma Gauge Couplings

Single W boson production in electron-positron collisions is studied with the L3 detector at LEP. The data sample collected at a centre-of-mass energy of \sqrt{s} = 188.7GeV corresponds to an integrated luminosity of 176.4pb^-1. Events with a single energetic lepton or two acoplanar hadronic jets are selected. Within phase-space cuts, the total cross-section is measured to be 0.53 +/- 0.12 +/- 0.03 pb, consistent with the Standard Model expectation. Including our single W boson results obtained at lower \sqrt{s}, the WWgamma gauge couplings kappa_gamma and lambda_gamma are determined to be kappa_gamma = 0.93 +/- 0.16 +/- 0.09 and lambda_gamma = -0.31 +0.68 -0.19 +/- 0.13