799 resultados para Aigua -- Conservació


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L'objecte del projecte és la construcció d'una hípica i el disseny de les seves instal•lacions utilitzant energies renovables i aprofitant al màxim els recursos d’una finca que està destinada principalment al cultiu de vinya i olivera. El terreny disposa d'una barraca de dues plantes de 36 metres quadrats cada una, una bassa d'aigua que només s'omple quan plou gràcies a un rec, un dipòsit d'aigua fet d'obra amb capacitat per a 50000 litres, un petit garatge de 10 metres quadrats i dos dipòsits metàl•lics de 25000 litres situats a una altura de 25 metres respecte el pla del terreny

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Disseny i muntatge d’un sistema de monitorització a temps real de la qualitat fisico-química de l’aigua en rius mediterranis, que sigui autònom telegestionat i de baix manteniment. Aquest sistema permet realitzar un seguiment de la dinàmica de la qualitat de l’aigua de riu, essent possible detectar episodis d’empitjorament sobtat de la qualitat. El desenvolupament de sensors per mesurar la qualitat de l’aigua en continu ha estat una realitat en la darrera dècada, millorant-ne la robustesa i baixant-ne els costos. Cada instrument cobreix diferents aplicacions dins el cicle de l’aigua, des d’aigües superficials de riu, aigües residuals o aigües potables. Actualment la dificultat no està en la sensorística, sinó en el desenvolupament d’estacions de monitorització autònomes i de baix manteniment

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Actualment en les industries farmacèutiques per aconseguir un producte amb unes condicionsespecifiques necessiten una sèrie de matèries primes per aconseguir-ho. L’aigua, es una de lesmes importants, d’aquí a la utilització d’una planta de tractament ja que ha de complir una sèriede requisit de qualitat determinats. Actualment en les industries farmacèutiques per aconseguir un producte amb unes condicionsespecifiques necessiten una sèrie de matèries primes per aconseguir-ho. L’aigua, es una de lesmes importants, d’aquí a la utilització d’una planta de tractament ja que ha de complir una sèriede requisit de qualitat determinats. Físicament, una planta d’aigua es podria descriure com un sistema estructurat de canonades idipòsits per on circula aigua i s’acumula mentre es depurada de forma continua. A mesura ques’aconsegueixen les condicions de puresa desitjades, el líquid es desvia a un altre anellanomenat llaç, en aquest s’acumula en un moviment circulatori constant mentre que les sevescaracterístiques es mantenen vigilades.Des de el llaç. L’aigua pura es distribueix per les diferents zones de la instal•lació, a unatemperatura determinada, a traves de sortidors anomenats punts d’us (POU) ((Point Of Use). El control es farà amb autòmat siemens S7-300 i una pantalla tàctil utilitzant comunicacióprofibus entre ells. Esta previst comunicació amb una scada existent, per intercanviar dadesnomés de visualització de l’estat de la planta. A partir d’un mòdul de teleservei serà possible lacomunicació amb el programa de l’autòmat via mòdem.La combinació de PLC mes pantalla tàctil esdevé una solució robusta i fiable, cosa quegaranteix una gran fiabilitat de la màquina

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Implementació d’un nou sistema de calefacció per a una granja d’engreix de pollastres. Es planteja el canvi de l’actual sistema de generació i distribució de calor (amb pantalles de gas propà), el qual és antic i ineficient pels seus anys de funcionament, per un sistema innovador mitjançant uns termoconvectors amb bescanvi aigua-aire. A més, la font de generació de calor serà amb una caldera de biomassa, aprofitant un combustible local i renovable: estella forestal. El canvi i la proposta d’instal•lació tenen dues finalitats ben diferenciades: millora en el maneig, la producció i el benestar animal dins de la nau dels pollastres d’engreix i estalvi econòmic potencial, fixat sobre el 70%, per millorar la rendibilitat de l’explotació i, a més, fomentant el consum d’un combustible renovable i de la zona, neutre en emissions de CO2. L’explotació ramadera es troba a Verges (Baix Empordà). L’empresa basa la seva activitat en l’engreix de pollastres i la producció extensiva de cereals

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The infilling of the river Ter Plain was produced by alluvial systems under the control of sea-level changes during the Quaternary. This paper describes the sedimentary evolution of the plain, and attemps to present a chronology of the recent geological events based on eustatic curves

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Drift has recived considerable attention in recent times as a method to collect chironomid pupal exuviae (COFFMAN, 1973; LAVILLE, 1979, 1981) for taxonomie as well as water pollution studies (WILSON, 1977).

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In 1999, a set of coordinated projects and investments whose principal objective was to transform Barcelona into one of the main distribution points of southern Europe resulted in the relocation of the Llobregat River mouth. The mouth was relocated by draining the old river mouth and constructing a new one. The aim of this study was to characterise the physico-chemical properties and the aquatic macroinvertebrate communities of the new river mouth and to monitor the changes experienced by the estuarine environment during its creation. A sampling point was established in the river 1.8 km upstream from its connection with the new mouth, and two sampling points were established in the new mouth. Samples of water and macroinvertebrates were collected every two months from May 2004 to June 2005, covering the periods before (from May to September 2004) and after (from September 2004 to June 2005) the new mouth was connected to the river and the sea. During the period before its connection to the river and the sea, the new mouth was functionally similar to a lagoon, with clear waters, charophytes and a rich invertebrate community. After the connection was completed, seawater penetrated the river mouth and extended to the connection point with the river (approximately 3.9 km upstream). An increase in conductivity from 4-6 mS cm 1 to 24-30 mS cm 1 caused important changes in the macroinvertebrate community of the new mouth. An initial defaunation was followed by a colonisation of the new mouth by brackish-water and marine invertebrate species. Due to its design (which allows the penetration of the sea) and the decreased discharge from the lower part of the Llobregat River, the new mouth has become an arm of the sea

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Biological water quality changes in two Mediterranean river basins from a network of 42 sampling sites assessed since 1979 are presented. In order to characterize the biological quality, the index FBILL, designed to characterize these rivers" quality using aquatic macroinvertebrates, is used. When comparing the data from recent years to older ones, only two headwater sites from the 42 had improved their water quality to good or very good conditions. In the middle or low river basin sites or even in headwater localities were river flow is reduced, the important investment to build up sewage water treatment systems and plants (more than 70 in 15 years) allowed for a small recovery from poor or very poor conditions to moderate water quality. Nevertheless still a significant number (25 %) of the localities remain in poor conditions. The evolution of the quality in several points of both basins shows how the main problems for the recovery of the biological quality is due to the water diverted for small hydraulic plants, the presence of saline pollution in the Llobregat River, and the insufficient water depuration. In the smaller rivers, and specially the Besòs the lack of dilution flows from the treatment plants is the main problem for water quality recovery.

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Durante abril de 2005 se realizó una campaña de muestreo de la vegetación acuática macroscópica en las cuencas de los ríos Foix, Besòs y Llobregat, sumando un total de 68 estaciones de muestreo. El objetivo principal fue evaluar el estado trófico de dichas cuencas mediante el índice trófico generado en España denominado IVAM (Índice de Vegetación Acuática Macroscópica). Se identificaron un total de 44 táxones, 8 géneros de Cyanophyta, 5 de Rodophyta, 2 de Xantophyceae, 3 de Bacillariophyceae, 15 de Clorophyta, 8 de Spermatophyta, 1 liquen y 2 briófitos (musgos y hepáticas). La cuenca del Llobregat fue la más diversa (37 t´axones), seguida del Besós (33) y el Foix (25). Los táxones más frecuentes fueron Cladophora, Vaucheria, Oedogonium, Apium, Rorippa y Oscillatoria, además de los musgos. Las fanerógamas fueron escasas, destacando los g´eneros Ranunculus, Zannichellia y Potamogeton. Los táxones que alcanzaron una mayor puntuación del IVAM (valor de tolerancia, vt = 8), aunque poco frecuentes, fueron Ranunculus, Cymbella, Rivularia, Nostoc, Tolypothrix, Chroococcus y Lemanea, todos indicadores de aguas oligotr´oficas. En aguas de buena calidad pero algo eutrofizadas (aguas mesotróficas, vt = 6), los táxones más frecuentes fueron Chara, Monostroma y Hildenbrandia, además de las hepáticas y un liquen. Según la calificación de los tramos en clases de estado trófico realizada por el IVAM, el 38.2% de los tramos presentaron una buena calidad (clases I y II) mientras que el 61.8% presentaron un estado trófico alterado (clases III, IV y V). La respuesta del IVAM a la concentración de nutrientes (fosfato, amonio, nitrito y nitrato) fue siempre significativa, destacando la alta correlación alcanzada con el ión fosfato (r = 0.71, p < 0.001), superior a la alcanzada por otros índices de diatomeas y macrófitos de resolución taxonómica específica. Este hecho confirma la ventaja de utilizar el IVAM en la evaluación del estado trófico de los ríos, ya que sin necesidad de alcanzar un nivel taxonómico de especie se obtiene una respuesta adecuada a dicha perturbación.

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Se presentan los resultados de un estudio sobre la ultraestructura y la multiplicación asexual de Microspora quadrata Hazen (Microsporaceae, Chlorophyta) en muestras procedentes de los lagos prepirenaicos, de tipo cárstico, de Basturs y Estaña. M. quadrata presenta las características ultraestructurales propias de la familia Microsporaceae; sus filamentos producen dos tipos de zoosporas biflageladas: esféricas y elípticas. Se describe, asimismo, el proceso de elongación de las zoosporas y se discute su función.

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In this paper we use a Terahertz (THz) time-domain system to image and analyze the structure of an artwork attributed to the Spanish artist Goya painted in 1771. The THz images show features that cannot be seen with optical inspection and complement data obtained with X-ray imaging that provide evidence of its authenticity, which is validated by other independent studies. For instance, a feature with a strong resemblance with one of Goya"s known signatures is seen in the THz images. In particular, this paper demonstrates the potential of THz imaging as a complementary technique along with X-ray for the verification and authentication of artwork pieces through the detection of features that remain hidden to optical inspection.

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Water is vital to humans and each of us needs at least 1.5 L of safe water a day to drink. Beginning as long ago as 1958 the World Health Organization (WHO) has published guidelines to help ensure water is safe to drink. Focused from the start on monitoring radionuclides in water, and continually cooperating with WHO, the International Standardization Organization (ISO) has been publishing standards on radioactivity test methods since 1978. As reliable, comparable and"fit for purpose" results are an essential requirement for any public health decision based on radioactivity measurements, international standards of tested and validated radionuclide test methods are an important tool for production of such measurements. This paper presents the ISO standards already published that could be used as normative references by testing laboratories in charge of radioactivity monitoring of drinking water as well as those currently under drafting and the prospect of standardized fast test methods in response to a nuclear accident.

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Several methods and approaches for measuring parameters to determine fecal sources of pollution in water have been developed in recent years. No single microbial or chemical parameter has proved sufficient to determine the source of fecal pollution. Combinations of parameters involving at least one discriminating indicator and one universal fecal indicator offer the most promising solutions for qualitative and quantitative analyses. The universal (nondiscriminating) fecal indicator provides quantitative information regarding the fecal load. The discriminating indicator contributes to the identification of a specific source. The relative values of the parameters derived from both kinds of indicators could provide information regarding the contribution to the total fecal load from each origin. It is also essential that both parameters characteristically persist in the environment for similar periods. Numerical analysis, such as inductive learning methods, could be used to select the most suitable and the lowest number of parameters to develop predictive models. These combinations of parameters provide information on factors affecting the models, such as dilution, specific types of animal source, persistence of microbial tracers, and complex mixtures from different sources. The combined use of the enumeration of somatic coliphages and the enumeration of Bacteroides-phages using different host specific strains (one from humans and another from pigs), both selected using the suggested approach, provides a feasible model for quantitative and qualitative analyses of fecal source identification.

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Water soluble perchlorinated trityl (PTM) radicals were found to be effective 95 GHz DNP (dynamic nuclear polarization) polarizers in ex situ (dissolution) 13C DNP (Gabellieri et al., Angew Chem., Int. Ed. 2010, 49, 3360). The degree of the nuclear polarization obtained was reported to be dependent on the position of the chlorine substituents on the trityl skeleton. In addition, on the basis of the DNP frequency sweeps it was suggested that the 13C NMR signal enhancement is mediated by the Cl nuclei. To understand the DNP mechanism of the PTM radicals we have explored the 95 GHz EPR characteristics of these radicals that are relevant to their performance as DNP polarizers. The EPR spectra of the radicals revealed axially symmetric g-tensors. A comparison of the spectra with the 13C DNP frequency sweeps showed that although the solid effect mechanism is operational the DNP frequency sweeps reveal some extra width suggesting that contributions from EPR forbidden transitions involving 35,37Cl nuclear flips are likely. This was substantiated experimentally by ELDOR (electron-electron double resonance) detected NMR measurements, which map the EPR forbidden transitions, and ELDOR experiments that follow the depolarization of the electron spin upon irradiation of the forbidden EPR transitions. DFT (density functional theory) calculations helped to assign the observed transitions and provided the relevant spin Hamiltonian parameters. These results show that the 35,37Cl hyperfine and nuclear quadrupolar interactions cause a considerable nuclear state mixing at 95 GHz thus facilitating the polarization of the Cl nuclei upon microwave irradiation. Overlap of Cl nuclear frequencies and the 13C Larmor frequency further facilitates the polarization of the 13C nuclei by spin diffusion. Calculation of the 13C DNP frequency sweep based on the Cl nuclear polarization showed that it does lead to an increase in the width of the spectra, improving the agreement with the experimental sweeps, thus supporting the existence of a new heteronuclear assisted DNP mechanism.

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Fruit d"un projecte multidisciplinar que aborda estudis dels materials del retaule de l"altar major del monestir de Santa Maria de Poblet des dels vessants històric, de conservació-restauració i geològic, en aquest treball es presenta una part dels resultats d"aquest projecte. L"anàlisi petrològica, física i química de les taques ocre-vermelloses que cobreixen part de la superfície de l"alabastre ha permès caracteritzarles i determinar-ne els possibles orígens.