739 research outputs found

    Significance of storage conditions on the flow properties of wheat flours

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    Flow properties of wheat flours are influenced by their intrinsic properties and environmental conditions during handling. This study evaluated the effects of environmental conditions (temperature and relative humidity- %RH) and flour properties (particle size and wheat class) on the flow properties of wheat flours. Size fractions from hard red winter (HRW) and soft red winter (SRW) wheat were produced through sieving. Flour fractions were then exposed to various temperature (25 and 35 degree Celsius) and relative humidity (50, 60, and 70%RH) combinations (t=3 h) to evaluate the effects of environmental conditions. Flow indicators (Hausner ratio – HR and compressibility index - CI) and flow (bulk, dynamic, and shear) properties were measured for the wheat flours after treatment. Shape analysis showed that all flour fractions were spherical based on their aspect ratio (>0.7) and elongation (4.0) which indicates poorer flowability. Higher humidity levels (60 and 70%) also caused poorer flowability for the wheat flours after exposure. The results from this study show that both environmental factors and flour characteristics have significant effects on flour flow properties. Handling wheat flours at lower humidity levels and higher temperatures improve flowability. Hard wheat flours were more flowable than soft wheat flours; coarser fractions from both wheat types flow better than finer fractions

    Evaluación de suelos de "El Condado" Huelva

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    91 páginas.-- 1 figura.-- 15 tablas.-- 20 fotos de suelos y perfiles de suelos.-- 15 referencias.-- Memoria ppresentada en el XXIV Curso Internacional de Edafología y Biología VegetalEl presente estudio, consiste en la evaluación de suelos, respecto al estudio básico a nivel de reconocimiento de la zona de El Condado perteneciente a la provincia de Huelva, que fue realizado como parte aplicada del XXII y XXIII Curso Internacional de Edafología y Biología Vegetal; sin embargo en esta oportunidad, dicha evaluación, es parte del XXIV Curso Internacional ya antes mencionado, lo cual contempla las áreas de la Palma del Condado hoja topográfica nº 982 y Moguer hoja topográfica nº 1000 respectivamente. El trabajo se desarrolló en cinco etapas principales; la primera o de gabinete (Pre-campo), que se hizo por medio de revisión y análisis de toda la información existente (Documento Base de reconocimiento escala 1:50.000, fotografías aéreas escala 1:40.000 de fecha 1984; mapas topográficos y geológicos escala 1:50.000 etc.). Luego con base a la información anterior, fue necesario una segunda etapa, consistente en la visita de campo (observación ocular), teniendo como fin, ampliar la visión o criterio del área geomorfológicamente y retroalimentar el gabinete inicial, lo cual ya con ' estas dos etapas fundamentales, se realizó una tercera, que nuevamente contempló el gabinete para hacerlos reajustes necesarios, dando como resultado, la conveniencia de hacer una segunda y última salida al campo, que luego. como etapa final de gabinete y con los resultados analíticos de laboratorio se hicieron las interpretaciones requeridas. También se realizaron otras etapas, como redacción, impresión y por consiguiente el documento final. El área estudiada, está situada en la Provincia de Huelva; comprende una extensión de 108.584 Has. Su ubicación geográfica se encuentra entre los paralelos 37º 10' 04" y 37º 30' 04" latitud norte y 6º 31' l0" y 6º 51' l0" de longitud oeste de Greenwich.Patrocinado por la UNESCO, Instituto de Cooperación Iberoamericana, Consejo Superior de Investigaciones CientíficasPeer reviewe

    Aplicação da interferometria holografia subaquática para análise de estruturas

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    Pretende-se com este trabalho estudar a aplicação das técnicas de interferometria holográfica à análise estrutural em ambiente subaquático. Estas técnicas estão hoje bem divulgadas e com aplicações em diversas áreas. No entanto, a sua aplicação em ambientes subaquáticos, apresenta alguns desafios. Neste trabalho estuda-se a aplicação de duas técnicas, ESPI e holografia digital, comparando-as e apresentando vantagens e desvantagens de cada uma delas. Faz-se um breve estudo sobre a influência das instabilidades resultantes da turbulência das águas e da presença de partículas em suspensão bem como possíveis soluções para minimizar estes problemas

    Nota corta. Patógenos telúricos aislados de planta de judía (Phaseolus vulgaris L.) con síntomas de mal de pie en Galicia

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    Pathogens belonging to the disease complex responsible for bean collar and root rots in northwest Spain were identified and their pathogenic behaviour studied over a two year period (2004-2005). The potential fungal and oomycete pathogens Fusarium solani f. sp. phaseoli (Burkh.) W.C. Snyder and Hansen, Rhizoctonia solani Kühn, Pythium ultimum Trow, Pythium Group G, Fusarium avenaceum (Fr.) Sacc., F. culmorum W. G. Sm. (Sacc.), Botrytis cinerea Pers., Sclerotinia sclerotiorum (Lib.) de Bary and Sclerotium rolfsii Sacc. were isolated from 419 bean (Phaseolus vulgaris L.) plants affected by collar or root rot. Fusarium solani f. sp. phaseoli was the most frequently isolated (found on 63.7% of the farms surveyed and isolated from 19.3% of the diseased plants), followed by R. solani and the Pythium species. Inoculating Phaseolus vulgaris cv. Música and Zondra with 14 isolates of these fungi and oomycetes showed F. solani f. sp. phaseoli to be the most aggressive pathogen of the complex; F. avenaceum and F. culmorum were found not to be pathogenic for either cultivar. The results confirm that F. solani and R. solani are the main pathogens of the bean collar/root rot disease complex in northwest Spain, affecting crops in their early growth stages. The complex also includes P. ultimum and Pythium Group G.Durante los años 2004 y 2005 se llevó a cabo en Galicia la identificación de los patógenos que formaban parte del complejo parasitario responsable del mal de pie en el cultivo de la judía, así como la evaluación de su poder patógeno. Los hongos y oomicetos patógenos potenciales aislados sobre un total de 419 plantas de judía (Phaseolus vulgaris L.) con síntomas de mal de pie, muestreados durante dicho período en Galicia, fueron los siguientes: Fusarium solani f. sp. phaseoli (Burkh.)W.C. Snyder y Hansen, Rhizoctonia solani Kühn, Pythium ultimum Trow, Pythium Grupo G, Fusarium avenaceum (Fr.) Sacc., F. culmorum W. G. Sm. (Sacc.), Botrytis cinerea Pers., Sclerotinia sclerotiorum (Lib.) de Bary y Sclerotium rolfsii Sacc. El patógeno más frecuentemente aislado fue F. solani f. sp. phaseoli, detectado en el 63,7% de las explotaciones muestreadas, así como en el 19,3% de las plantas analizadas, seguido de R. solani y de Pythium spp. Las pruebas de inoculación de 14 aislamientos de estos hongos y oomicetos sobre las variedades de judía Música y Zondra indicaron que F. solani f. sp phaseoli posee el mayor poder patógeno, mientras que F. avenaceum y F. culmorum no resultaron ser patogénicos sobre ninguna de las dos variedades inoculadas. Los resultados de este trabajo confirman que F. solani y R. solani son los principales patógenos responsables del mal de pie de la judía en Galicia, complejo parasitario que incluye también a P. ultimum y P. Grupo G en los primeros estadíos del cultivo

    Orbital structure of the GJ876 extrasolar planetary system, based on the latest Keck and HARPS radial velocity data

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    We use full available array of radial velocity data, including recently published HARPS and Keck observatory sets, to characterize the orbital configuration of the planetary system orbiting GJ876. First, we propose and describe in detail a fast method to fit perturbed orbital configuration, based on the integration of the sensitivity equations inferred by the equations of the original NN-body problem. Further, we find that it is unsatisfactory to treat the available radial velocity data for GJ876 in the traditional white noise model, because the actual noise appears autocorrelated (and demonstrates non-white frequency spectrum). The time scale of this correlation is about a few days, and the contribution of the correlated noise is about 2 m/s (i.e., similar to the level of internal errors in the Keck data). We propose a variation of the maximum-likelihood algorithm to estimate the orbital configuration of the system, taking into account the red noise effects. We show, in particular, that the non-zero orbital eccentricity of the innermost planet \emph{d}, obtained in previous studies, is likely a result of misinterpreted red noise in the data. In addition to offsets in some orbital parameters, the red noise also makes the fit uncertainties systematically underestimated (while they are treated in the traditional white noise model). Also, we show that the orbital eccentricity of the outermost planet is actually ill-determined, although bounded by ∼0.2\sim 0.2. Finally, we investigate possible orbital non-coplanarity of the system, and limit the mutual inclination between the planets \emph{b} and \emph{c} orbits by 5∘−15∘5^\circ-15^\circ, depending on the angular position of the mutual orbital nodes.Comment: 36 pages, 11 figures, 3 tables; Accepted to Celestial Mechanics and Dynamical Astronom

    Physicochemical, traction and tribofilm formation properties of three octanoate-, laurate- and palmitate-anion based ionic liquids

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    Three new ionic liquids with different anions and the same cation were synthesized from fatty acids through a metathesis reaction.All the ionic liquidswere identified viaNMRand FTIR and several properties (density, viscosity, thermal, and environmental) were measured. Traction tests were performed under different entrainment speeds (10–2000 mm/s), at slide-roll ratio (SRR) of 50% and 30 N-load, and at different temperatures (40, 60, 80 and 100 °C) using a mini-traction machine (MTM). Tribofilm formation tests were also made in the MTM at 50 N-load, 150 mm/s of entrainment speed, at SRR of 50% and temperature of 100 °C, for 60 min. This work showed that the alkyl chain length in the anion affects properties such as viscosity, toxicity, biodegradability and lubrication. Viscosity decreased with increasing alkyl chain length but only below 60 °C, at higher temperatures the viscosity values of the ionic liquids converge. The toxicity increases with the alkyl chain length; whereas, biodegradability shows the opposite behavior. These novel ionic liquids are much better from both toxicity and biodegradability points of view than the [N8881][TFSI] ionic liquid, which contains the same cation and anion not coming from fatty acids. The ionic liquids at low temperature (40 °C) performed under elastohydrodynamic lubrication and changed to mixed lubrication at higher temperatures and decreasing speeds, according to the alkyl chain length of each anion. All ionic liquids adsorbed on the steel surfaces, and the tribofilm thickness and the kinetics of formation were different

    Narrow-band photodetection based on M-plane GaN films

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    Rapid identification of a range of hazardous airborne biological and chemical agents requires simultaneous detection at several specific wavelengths, and consequently a set of photodetectors with very narrow-band spectral responsivity. We demonstrate two ultraviolet photodetection configurations based on strained M-plane GaN films on LiAlO2(100) substrates grown by molecular-beam epitaxy with a detection bandwidth below 8 nm. The optical band gap of the film depends on the orientation of the linear polarization of the incident light relative to the c-axis of GaN, which lies in the film plane. The first configuration consists of a polarizationsensitive planar Schottky photodetector and a filter. An orthogonal alignment of the c-axis of the photodetector and the filter produces a detection system with a peak responsivity at 360 nm and a bandwidth of 6 nm. The second one consists of two planar Schottky photodetectors with their c-axes oriented perpendicular to each other. The difference signal between the two photodetectors produces a peak responsivity at 358 nm and a bandwidth of 7.3 nm

    Characterization and wear performance of boride phases over tool steel substrates

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    This research work was conducted to characterize boride phases, obtained from the powder-pack process, on AISI H13 and D2 steel substrates, and investigate their tribological behavior. The boriding was developed at a temperature of 1273 K with an exposure time of 8 h. X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were conducted on the borided material to characterize the presence of the FeB, Fe2B, and CrB phases and the distribution of heavy elements on the surface of the substrates. The adherence of the boride layers was evaluated, in a qualitative form, through the Daimler-Benz Rockwell-C indentation technique. Sliding wear tests were then performed using a reciprocating wear test machine. All tests were conducted in dry conditions at room temperature. A frequency of 10 Hz and 15-mm sliding distance were used. The applied Hertzian pressure was 2.01 GPa. Scanning electron microscopy was used to observe and analyze the wear mechanisms. Additionally, the variation of the friction coefficient versus the number of cycles was obtained. Experimental results showed that the characteristic wear mechanism for the borided surface was plastic deformation and mild abrasive wear; for unborided substrates, cracking and spalling were observed

    Establishing a governance threshold in small-scale fisheries to achieve sustainability

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    The lack of effective governance is a major concern in small-scale fisheries. The implementation of governance that encompasses the three pillars of sustainability (social, economic, and ecological) is still a worldwide challenge. We examined nine stalked barnacle fisheries (Pollicipes pollicipes) across Southwest Europe to better understand the relationship between governance elements and sustainability. Our results show that nested spatial scales of management, the access structure, co- management, and fisher’s participation in monitoring and surveillance promote sustainability. However, it is not the mere presence of these elements but their level of implementation that drives sustainability. Efforts should be placed in the accomplishment of a minimum combination of local scales of management, access rights through individual quotas, instructive-consultative co- management and functional participation. Surpassing this threshold in future governance structures will start to adequately promote social, economic and ecologically sustainability in small-scale fisheries
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