Analysis of Contributions to NO2 Ambient Air Quality Levels in Madrid City (Spain) through Modeling. Implications for the Development of Policies and Air Quality Monitoring

As environmental standards become more stringent (e.g. European Directive 2008/50/EC), more reliable and sophisticated modeling tools are needed to simulate measures and plans that may effectively tackle air quality exceedances, common in large cities across Europe, particularly for NO2. Modeling air quality in urban areas is rather complex since observed concentration values are a consequence of the interaction of multiple sources and processes that involve a wide range of spatial and temporal scales. Besides a consistent and robust multi-scale modeling system, comprehensive and flexible emission inventories are needed. This paper discusses the application of the WRF-SMOKE-CMAQ system to the Madrid city (Spain) to assess the contribution of the main emitting sectors in the region. A detailed emission inventory was compiled for this purpose. This inventory relies on bottom-up methods for the most important sources. It is coupled with the regional traffic model and it makes use of an extensive database of industrial, commercial and residential combustion plants. Less relevant sources are downscaled from national or regional inventories. This paper reports the methodology and main results of the source apportionment study performed to understand the origin of pollution (main sectors and geographical areas) and define clear targets for the abatement strategy. Finally the structure of the air quality monitoring is analyzed and discussed to identify options to improve the monitoring strategy not only in the Madrid city but the whole metropolitan area.

Methodology of image analysis for study of the vertisols moisture content

The main problem to study vertical drainage from the moisture distribution, on a vertisol profile, is searching for suitable methods using these procedures. Our aim was to design a digital image processing methodology and its analysis to characterize the moisture content distribution of a vertisol profile. In this research, twelve soil pits were excavated on a ba re Mazic Pellic Vertisols ix of them in May 13/2011 and the rest in May 19 /2011 after a moderate rainfall event. Digital RGB images were taken from each vertisol pit using a Kodak? camera selecting a size of 1600x945 pixels. Each soil image was processed to homogenized brightness and then a spatial filter with several window sizes was applied to select the optimum one. The RGB image obtained were divided in each matrix color selecting the best thresholds for each one, maximum and minimum, to be applied and get a digital binary pattern. This one was analyzed by estimating two fractal scaling exponents box counting dimension D BC) and interface fractal dimension (D) In addition, three pre-fractal scaling coefficients were determinate at maximum resolution: total number of boxes intercepting the foreground pattern (A), fractal lacunarity (?1) and Shannon entropy S1). For all the images processed the spatial filter 9x9 was the optimum based on entropy, cluster and histogram criteria. Thresholds for each color were selected based on bimodal histograms.

Polymer interaction with macroscopic carbon nanotube fibres and fabrication of nanostructured composites

El ensamblado de nanotubos de carbono (CNT) como una fibra macroscópica en la cual están orientados preferentemente paralelos entre sí y al eje de la fibra, ha dado como resultado un nuevo tipo de fibra de altas prestaciones derivadas de la explotación eficiente de las propiedades axiales de los CNTs, y que tiene un gran número de aplicaciones potenciales. Fibras continuas de CNTs se produjeron en el Instituto IMDEA Materiales mediante el proceso de hilado directo durante la reacción de síntesis por deposición química de vapores. Uno de los objetivos de esta tesis es el estudio de la estructura de estas fibras mediante técnicas del estado del arte de difracción de rayos X de sincrotrón y la elaboración de un modelo estructural de dicho material. Mediciones texturales de adsorción de gases, análisis de micrografías de electrones y dispersión de rayos X de ángulo alto y bajo (WAXS/SAXS) indican que el material tiene una estructura mesoporosa con una distribución de tamaño de poros ancha derivada del amplio rango de separaciones entre manojos de CNTs, así como una superficie específica de 170m2/g. Los valores de dimensión fractal obtenidos mediante SAXS y análisis Barrett-Joyner-Halenda (BJH) de mediciones texturales coinciden en 2.4 y 2.5, respectivamente, resaltando el carácter de red de la estructura de dichas fibras. La estructura mesoporosa y tipo hilo de las fibra de CNT es accesible a la infiltración de moléculas externas (líquidos o polímeros). En este trabajo se estudian los cambios en la estructura multiescala de las fibras de CNTs al interactuar con líquidos y polímeros. Los efectos de la densificación en la estructura de fibras secas de CNT son estudiados mediante WAXS/SAXS. El tratamiento de densificación junta los manojos de la fibra (los poros disminuyen de tamaño), resultando en un incremento de la densidad de la fibra. Sin embargo, los dominios estructurales correspondientes a la transferencia de esfuerzo mecánica y carga eléctrica en los nanotubos no son afectados durante este proceso de densificación; como consecuencia no se produce un efecto sustancial en las propiedades mecánicas y eléctricas. Mediciones de SAXS and fibra de CNT antes y después de infiltración de líquidos confirman la penetración de una gran cantidad de líquidos que llena los poros internos de la fibra pero no se intercalan entre capas de nanotubos adyacentes. La infiltración de cadenas poliméricas de bajo peso molecular tiende a expandir los manojos en la fibra e incrementar el ángulo de apertura de los poros. Los resultados de SAXS indican que la estructura interna de la fibra en términos de la organización de las capas de tubos y su orientación no es afectada cuando las muestras consisten en fibras infiltradas con polímeros de alto peso molecular. La cristalización de varios polímeros semicristalinos es acelerada por la presencia de fibras de CNTs alineados y produce el crecimiento de una capa transcristalina normal a la superficie de la fibra. Esto es observado directamente mediante microscopía óptica polarizada, y detectado mediante calorimetría DSC. Las lamelas en la capa transcristalina tienen orientación de la cadena polimérica paralela a la fibra y por lo tanto a los nanotubos, de acuerdo con los patrones de WAXS. Esta orientación preferencial se sugiere como parte de la fuerza impulsora en la nucleación. La nucleación del dominio cristalino polimérico en la superficie de los CNT no es epitaxial. Ocurre sin haber correspondencia entre las estructuras cristalinas del polímero y los nanotubos. Estas observaciones contribuyen a la compresión del fenómeno de nucleación en CNTs y otros nanocarbonos, y sientan las bases para el desarrollo de composites poliméricos de gran escala basados en fibra larga de CNTs alineados. ABSTRACT The assembly of carbon nanotubes into a macroscopic fibre material where they are preferentially aligned parallel to each other and to the fibre axis has resulted in a new class of high-performance fibres, which efficiently exploits the axial properties of the building blocks and has numerous applications. Long, continuous CNT fibres were produced in IMDEA Materials Institute by direct fibre spinning from a chemical vapour deposition reaction. These fibres have a complex hierarchical structure covering multiple length scales. One objective of this thesis is to reveal this structure by means of state-of-the-art techniques such as synchrotron X-ray diffraction, and to build a model to link the fibre structural elements. Texture and gas absorption measurements, using electron microscopy, wide angle and small angle X-ray scattering (WAXS/SAXS), and pore size distribution analysis by Barrett-Joyner-Halenda (BJH), indicate that the material has a mesoporous structure with a wide pore size distribution arising from the range of fibre bundle separation, and a high surface area _170m2/g. Fractal dimension values of 2.4_2.5 obtained from the SAXS and BJH measurements highlight the network structure of the fibre. Mesoporous and yarn-like structure of CNT fibres make them accessible to the infiltration of foreign molecules (liquid or polymer). This work studies multiscale structural changes when CNT fibres interact with liquids and polymers. The effects of densification on the structure of dry CNT fibres were measured by WAXS/SAXS. The densification treatment brings the fibre bundles closer (pores become smaller), leading to an increase in fibre density. However, structural domains made of the load and charge carrying nanotubes are not affected; consequently, it has no substantial effect on mechanical and electrical properties. SAXS measurements on the CNT fibres before and after liquid infiltration imply that most liquids are able to fill the internal pores but not to intercalate between nanotubes. Successful infiltration of low molecular weight polymer chains tends to expand the fibre bundles and increases the pore-opening angle. SAXS results indicate that the inner structure of the fibre, in terms of the nanotube layer arrangement and the fibre alignment, are not largely affected when infiltrated with polymers of relatively high molecular weight. The crystallisation of a variety of semicrystalline polymers is accelerated by the presence of aligned fibres of CNTs and results in the growth of a transcrystalline layer perpendicular to the fibre surface. This can be observed directly under polarised optical microscope, and detected by the exothermic peaks during differential scanning calorimetry. The discussion on the driving forces for the enhanced nucleation points out the preferential chain orientation of polymer lamella with the chain axis parallel to the fibre and thus to the nanotubes, which is confirmed by two-dimensional WAXS patterns. A non-epitaxial polymer crystal growth habit at the CNT-polymer interface is proposed, which is independent of lattice matching between the polymer and nanotubes. These findings contribute to the discussion on polymer nucleation on CNTs and other nanocarbons, and their implication for the development of large polymer composites based on long and aligned fibres of CNTs.

La arquitectura religiosa en Santiago de Chile 1850-1950: razones de las reminiscencias góticas

Históricamente la estrategia de localización de la infraestructura religiosa católica en Chile ha estado condicionada por intenciones destinadas a la captación y tutela de feligreses, proceso desarrollado a través de intervenciones que han generado externalidades difíciles de anticipar y posibles de visualizar en un marco temporal mayor. En este contexto la producción e instalación de los templos católicos en distintos lugares de la ciudad condicionaron los territorios y marcaron presencia en su afán por colonizar y mantener el dominio, mecanismo propio de la institución religiosa que se adaptó al medio y a las circunstancias político social para cumplir su misión y mantener el poder. En esta investigación se buscó identificar desde las edificaciones destinadas al culto, la relación escalar entre localización, modo de instalación y morfología que incluye la forma y técnica de construcción, reconociendo la manera cómo modifican los entornos, el efecto que provocan y las expectativas que abren a nuevas intervenciones. El escenario escogido para realizar el estudio correspondió a un período de la historia de la ciudad de Santiago de Chile no documentado en que las circunstancias políticas, económicas, sociales y culturales contribuyeron a que el modo de disposición de las edificaciones de culto condicionaron el desarrollo urbano y orientaron el crecimiento de la ciudad. El período en que se desarrolló el estudio correspondió a la época de mayor riqueza material y cultural de la historia del país y estuvo modelada por las intenciones y planes de desarrollo tendientes a consolidar lo que se ha denominado el modelo Republicano. Escenario en que el espacio público cobró interés y se transformó en el motor de los cambios e indicador de la escala de la ciudad, estableciendo las condiciones para que las distintas corrientes europeas se manifestaran en el hacer arquitectónico cambiando la imagen original de la ciudad colonial. Este proceso que ocurrió sobre la estructura existente, densificó la manzana a través de la subdivisión predial, que complementado con los avances tecnológicos permitieron mayores alturas de edificación, situación que dio origen a nuevas concepciones espaciales, posibles de desarrollar con los recursos materiales, intelectuales y técnicos disponibles. El estudio se centró en la centuria 1850-1950 analizando la forma como la infraestructura religiosa Católica se localizó en el tejido urbano adoptando distintas tipologías edilicias, en una época caracterizada por el eclecticismo arquitectónico. Específicamente se estudiaron las edificaciones que utilizaron reminiscencias góticas, identificando los casos más significativos, estableciendo el contexto en que se originaron e indagando en la significación que tuvieron por la función que cumplieron, considerando emplazamiento y conexión con el entorno construido, conformación, dimensiones, destino y patrocinios. El área de estudio se fundamentó por la concentración de construcciones con la tendencia historicista, producciones que en el corto y mediano plazo orientaron las transformaciones de la ciudad y por la presencia que conservan hasta estos días. Se observó la incidencia de la acción de la Iglesia Católica en las políticas de Estado, orientando las decisiones de planificación y ocupación del territorio, condicionando la localización de los templos a fin de conseguir las mayores coberturas de la población y el mayor rendimiento de las inversiones. En el contexto latinoamericano la construcción de iglesias, templos y catedrales con reminiscencias góticas fue una constante que caracterizó al último cuarto del siglo XIX y las tres primeras décadas del siglo XX. El estudio permitió conocer en términos cuantitativos y cualitativos la producción, destacando la morfología y materialidad caracterizada por la adopción de estrategias contemporáneas estructuralmente exigentes. Se observó la utilización de la arquitectura como un medio de acercamiento a la población, capaz de transformar a los edificios en símbolos barriales, que facilitaron la generación de identidad, al convertirse en los referentes materiales que se destacan, que se recuerdan y que asumen la representatividad de barrios, permaneciendo en el tiempo y convirtiéndose en íconos asociados a la cultura local. En síntesis, la instalación de las infraestructuras religiosas en la ciudad de Santiago fue consecuencia de un modo de producción, que entregó lugares de encuentro y símbolos para la ciudad, a través de la localización de los edificios que buscaron ocupar áreas visibles, relevantes y convocantes, lo que consiguieron mediante la instalación geográfica, central y equidistante de conglomerados residenciales consolidados o en vías de desarrollo, como también a través de edificaciones monumentales y siempre destacadas respecto de su entorno, lo que marcó exclusividad y dominio. La elección de tipos arquitectónicos fue coyuntural a los tiempos e inspirada en intelectuales y profesionales mayoritariamente foráneos que aportaron conocimientos y experiencia para auspiciar edificaciones que fueron reconocidas como señeras y precursoras de la época. La intensidad en el uso de los recursos que demandaron las exigentes estructuras obligó a la iglesia católica a establecer estrategias de financiación destinadas a suplir la falta de recursos provenientes del Estado. Para lo cual convocaron a distintos actores los que participaron desde sus fronteras y en función de sus intereses cubriendo desde el altruismo hasta la rentabilización de su patrimonio. La organización iglesia católica se comporta de la misma manera que cualquier otra organización: busca expandirse, concentrar, controlar y administrar. Busca codificar todo su entorno (Raffestin, 2011), busca trascender y materialmente lo logra desde sus construcciones. ABSTRACT Historically the location strategies of the catholic religious infrastructure in Chile has been conditioned by intentions aimed at attracting and guardianship of parishioners, process developed through interventions that have generated externalities difficult to anticipate and possible to visualize in a in a major temporary frame. In this context, the production and installation of the catholic churches in different places in the city determined the territories and marked presence in their quest to colonize and maintain domain, mechanism of the religious institution that was adapted to the environment and in the political and social circumstances to fulfill its mission and maintain power. This research sought to identify from the buildings intended for worship in a multi-scale relationship between location, the placement mode, morphology and shape and construction technique and the effect caused by them, the way how they alter the environments and the expectations that are open to new interventions. The chosen scenario for the study corresponded to a not documented period in the history of the city of Santiago de Chile in which political, economic, social and cultural circumstances contributed to the form of disposition of the buildings of worship that determined the urban development and guided the growth of the city. The study period was the epoch of largest material and cultural wealth of Chile history and it was modeled by the intentions and development plans tending to consolidate what has been named the Republican ideal. Scenario in which public space gained interest and became the engine of change and indicator of the scale of the city, establishing the conditions for the various European trends manifested themselves in transforming the original image of the colonial city. This process that took place on the existing structure, produced a higher density of the original blocks through the predial compartimentation, which supplemented with technological advances enabled greater building heights, a situation that gave rise to new spatial conceptions, possible of developing with the material resources, intellectuals and technicians available at the moment. The study focused on the century 1850-1950 by analyzing how the Catholic religious infrastructure was located in the urban fabric by adopting different typologies locality, in an epoch characterised by architectural eclecticism. Specifica lly, it is studied the buildings that used gothic reminiscences, identifying the most significant cases, establishing the context in which they originated and inquiring about the significance that they had for the role it played, considering location and connection to the built environment, shaping, dimensions, destination, and sponsorships. The study area was established by the concentration of buildings with this historicist trend, productions that in the short and medium term guided the transformation of the city and the presence that keeps up to these days. It was noted the incidence of the of the Catholic Church actions in guiding State policies, planning decisions and occupation of the territory, as well as conditioning the location of the temples in order to achieve greater coverage of the population and the greatest return on investment. In the context of Latin America the construction of churches, temples and cathedrals with reminiscences gothic was a constant that characterized the last quarter of the nineteenth century and the first three decades of the twentieth century. The study allowed to know in quantitative and qualitative terms the production of the period, highlighting the morphology and materiality characterized by contemporary and structurally challenging strategies. It was noted the use of architecture as a means of approaching to the population, able to transform buildings into neighborhood symbols, which facilitated the production of identity, to become the reference materials that stand out, that will be remembered and that assume the representativeness of neighborhoods, remaining in the time and becoming icons associated with the local culture. In synthesis, the installation of religious infrastructure in the city of Santiago was result of a mode of production, that provided meeting places and symbols for the city, through the location of buildings that sought to occupy visible, relevant and summoning areas, what they obtained by means of the geographical, central and equidistant installation of consolidated residential conglomerates cluster or about to development, as also through always outstanding and monumental buildings with respect to its surroundings, which marked uniqueness and domain. The choice of architectural types was related to the time and inspired by intellectuals and professionals mostly outsiders who contributed with expertise and experience to sponsor buildings were recognized as outstanding and precursor of the time. The intensity of use of the resources that requested the demanding structures forced to the Catholic church to establish funding strategies designed to compensate for the lack of funds from the State. For which convened to different actors who participated from their borders and depending on their interests covering from the altruism up to the rentabilización of its patrimony. The Catholic Church organization behaves the same way as any other organization: seeks to expand, focus, control and manage. Looking for coding the entire environment (Raffestin, 2011), seeks to transcend and succeeds materially from its building.

Propriedades superficiais de filmes à base de gelatina

O objetivo do presente trabalho foi caracterizar as propriedades superficiais de filmes à base de gelatina. Para o qual foram elaborados filmes de: (i) Gelatina plastificado com glicerol (G) (gelatina: 5 g/100 g SFF; glicerol: 30 g/100 g de gelatina), (ii) Gelatina reforçado com montmorilhonita (G/MMT) (gelatina: 5 g/100 g SFF; glicerol: 30 g/100 g de gelatina; MMT: 5 g/100 g de gelatina) e Gelatina plastificado com citrato de acetiltributila (G/ATB) (gelatina: 5 g/100 g SFF; ATB: 50 g/100 de gelatina; lecitina de soja: 60 g/100 g de ATB; etanol: 20 g/100 g SFF). Os filmes foram produzidos mediante o uso de um aplicador automático de filmes \"Spreading\". Logo, os filmes foram submetidos a testes para determinação da espessura, umidade e propriedades óticas (brilho, cor e opacidade). Também foi caracterizada a microestrutura por microscopia eletrônica de varredura (MEV) e microscopia de força atômica (AFM); às imagens obtidas por MEV foi aplicado um analise de imagem mediante o programa Image J, para obter o valor da dimensão fractal (DF). Depois foram caracterizadas as propriedades superficiais de ângulo de contato (AC), molhabilidade ou coeficiente de espalhamento (Se), e energia livre superficial (ELS) mediante a medida do ângulo de contato pelo método da gota séssil (água: 5 µL e 1-Bromonaftaleno: 3 µL). Para o cálculo da ELS também foi aplicado o método de Owens-Wendt. Estas caracterizações foram feitas em ambos os lados do filme, lado ar e lado placa. A natureza do filme de G/ATB influenciou na umidade e as propriedades óticas, enquanto que os filmes de G e G/MMT apresentaram características similares. Em relação à microestrutura e rugosidade, o filme de G apresentou a superfície mais homogênea e lisa, contrario ao observado no filme de G/MMT, que apresentou a maior rugosidade seguida do filme de G/ATB. Foi observado que houve uma relação entre os valores de rugosidade e DF. De acordo com o valor do AC, os filmes apresentaram um caráter hidrofóbico, pois seus valores foram superiores a 65° (em ambos os lados dos filmes), na seguinte ordem: G/MMT > G > G/ATB; sendo que o Se seguiu a mesma tendência. Cabe mencionar também que não foi encontrada uma correlação significativa entre os valores de AC e rugosidade. Em função dos valores de AC, Se e ELS (especificamente a componente polar), o filme de G/ATB apresentou o menor caráter hidrofóbico, pois apresentou menores valores de AC e maiores valores de Se em comparação com os outros dois filmes. Os valores da componente polar da G/ATB foram os maiores, explicando de melhor maneira o caráter menos hidrofóbico deste filme. Pode-se concluir que os filmes à base de gelatina elaborados no presente trabalho têm propriedades hidrofóbicas (AC>65°), sendo a G/MMT o filme com melhores características hidrofóbicas.

An introduction to alysidal algebra (V): phenomenological components

Purpose – This paper aims to refer to a subjective approach to a type of complex system: human ecosystems, referred to as deontical impure systems (DIS) to capture a set of properties fundamental to the distinction between human and natural ecosystems. There are four main phenomenological components: directionality, intensity, connection energy and volume. The paper establishes thermodynamics of deontical systems based on the Law of Zipf and the temperature of information. Design/methodology/approach – Mathematical and logical development of human society structure. Findings – A fundamental question in this approach to DIS is the intensity or forces of a relation. Concepts are introduced as the system volume and propose a system thermodynamic theory. It hints at the possibility of adapting the fractal theory by introducing the fractal dimension of the system. Originality/value – This paper is a continuation of other previous papers and developing the theory of DIS.

The current challenges of Color Physics and Chemistry

Day of Chemistry, Invited conference, San Alberto Magno 2014

Particel size distribution and microstructures of sediments from ODP Leg 205 sites (Table 1)

Ocean Drilling Program Legs 170 and 205 offshore Costa Rica provide structural observations which support a new model for the geometry and deformation response to the seismic cycle of the frontal sedimentary prism and decollement. The model is based on drillcore, thin section, and electron microscope observations. The decollement damage zone is a few tens of meters in width, it develops mainly within the frontal prism. A clear cm-thick fault core is observed 1.6 km from the trench. The lower boundary of the fault core is coincident with the lithological boundary between the frontal prism and the hemipelagic and pelagic sediment of the Cocos plate. Breccia clast distributions in the upper portion of the decollement damage zone were studied through fractal analysis. This analysis shows that the fractal dimension changes with brecciated fragment size, implying that deformation was not accommodated by self-similar fracturing. A higher fractal dimensionality correlates with smaller particle size, which indicates that different or additional grain-size reduction processes operated during shearing. The co-existence of two distinct fracturing processes is also confirmed by microscopic analysis in which extension fracturing in the upper part of the damage zone farthest from the fault core is frequent, while both extension and shear fracturing occur approaching the fault core. The coexistence of extensional and shear fracturing seems to be best explained by fluid pressure variations in response to variations of the compressional regime during the seismic cycle. During the co-seismic event, sub-horizontal compression and fluid pressure increase, triggering shear fracturing and fluid expulsion. Fractures migrate upward with fluids, contributing to the asymmetric shape of the decollement, while slip propagates. In the inter-seismic interval the frontal prismrelaxes and fluid pressure drops. The frontal prismgoes into diffuse extension during the intervalwhen plate convergence is accommodated by creep along the ductile fault core. The fault core is typically a barrier to deformation, which is explained by its weak, but impermeable, nature. The localized development of a damage zone beneath the fault core is characterized by shear fracturing that appears as the result of local strengthening of the detachment.

Homogeneous Spatial Units (HSU) - a Pan-European geographical basis for environmental and socio-economic modelling

The spatial data set delineates areas with similar environmental properties regarding soil, terrain morphology, climate and affiliation to the same administrative unit (NUTS3 or comparable units in size) at a minimum pixel size of 1km2. The scope of developing this data set is to provide a link between spatial environmental information (e.g. soil properties) and statistical data (e.g. crop distribution) available at administrative level. Impact assessment of agricultural management on emissions of pollutants or radiative active gases, or analysis regarding the influence of agricultural management on the supply of ecosystem services, require the proper spatial coincidence of the driving factors. The HSU data set provides e.g. the link between the agro-economic model CAPRI and biophysical assessment of environmental impacts (updating previously spatial units, Leip et al. 2008), for the analysis of policy scenarios. Recently, a statistical model to disaggregate crop information available from regional statistics to the HSU has been developed (Lamboni et al. 2016). The HSU data set consists of the spatial layers provided in vector and raster format as well as attribute tables with information on the properties of the HSU. All input data for the delineation the HSU is publicly available. For some parameters the attribute tables provide the link between the HSU data set and e.g. the soil map(s) rather than the data itself. The HSU data set is closely linked the USCIE data set.

Analyzation of marine snow and fecal pellets collected in sediment trap CBi-2 off Cape Blanc, Mauritania

We analyzed size-specific dry mass, sinking velocity, and apparent diffusivity in field-sampled marine snow, laboratory-made aggregates formed by diatoms or coccolithophorids, and small and large zooplankton fecal pellets with naturally varying content of ballast materials. Apparent diffusivity was measured directly inside aggregates and large (millimeter-long) fecal pellets using microsensors. Large fecal pellets, collected in the coastal upwelling off Cape Blanc, Mauritania, showed the highest volume-specific dry mass and sinking velocities because of a high content of opal, carbonate, and lithogenic material (mostly Saharan dust), which together comprised ~80% of the dry mass. The average solid matter density within these large fecal pellets was 1.7 g cm**-3, whereas their excess density was 0.25 ± 0.07 g cm**-3. Volume-specific dry mass of all sources of aggregates and fecal pellets ranged from 3.8 to 960 µg mm**-3, and average sinking velocities varied between 51 and 732 m d**-1. Porosity was >0.43 and >0.96 within fecal pellets and phytoplankton-derived aggregates, respectively. Averaged values of apparent diffusivity of gases within large fecal pellets and aggregates were 0.74 and 0.95 times that of the free diffusion coefficient in sea water, respectively. Ballast increases sinking velocity and, thus, also potential O2 fluxes to sedimenting aggregates and fecal pellets. Hence, ballast minerals limit the residence time of aggregates in the water column by increasing sinking velocity, but apparent diffusivity and potential oxygen supply within aggregates are high, whereby a large fraction of labile organic carbon can be respired during sedimentation.

The comparative characterization of structural heterogeneity of mesoporous activated carbon fibers (ACFs)

The comparative analysis of the most widely used methods of mesoporosity characterization of two activated carbon fibers is presented. Not only the older methods are used, i.e. Barrett, Joyner and Halenda (BJH), Dubinin (the so-called first variant-D-1ST and the so-called second variant-D-2ND), Dollimore and Heal (DH), and Pierce (P) but the recently developed ones, i.e. the method of Nguyen and Do (ND) and that developed by Do (Do) are also applied. Additionally, the method of the characterization of fractality is put to use (fractal analog of FHH isotherm). The results are compared and discussed. (C) 2002 Elsevier Science B.V. All fights reserved.

Impacts of morphological, physical and chemical properties of sludge flocs on dewaterability of activated sludge

This study examined how the floc characteristics affect dewaterability of activated sludge. The floc properties were characterized by morphological parameters (floc size distribution, fractal dimension and filament index), physical properties (flocculating ability, surface charge, relative hydrophobicity and viscosity), and chemical constituents in sludge and extracted extracellular polymeric substances (EPS), including the polymeric compounds protein, humic substances, carbohydrates and the ions Ca2+, Mg2+, Fe3+ and Al3+. The dewaterability was defined in terms of the bound water content and capillary suction time (CST). The bound water and CST corresponded to a similar indication with respect to dewaterability of activated sludge. The floc physical parameters were the most important factors which effect significantly on the water binding ability of the sludge flocs. The morphological characteristics had relatively weak impact on the dewaterability. The polymeric components protein and carbohydrate had a significant contribution to enhance the water binding ability of the sludge flocs. The effect of humic substances in the sludge on the dewaterability was, however, insignificant. The CST had good statistical correlations with the polymeric constituents measured in both sludge and the extracted EPS, and the bound water was only correlated well with the individual polymers measured in the sludge. High concentration of Ca2+, Mg2+, Fe3+ and Al3+ had significant improvement for dewaterability. (C) 2003 Elsevier B.V. All rights reserved.

Indexing and integrating multiple features for WWW images

In this paper, we present a novel indexing technique called Multi-scale Similarity Indexing (MSI) to index image's multi-features into a single one-dimensional structure. Both for text and visual feature spaces, the similarity between a point and a local partition's center in individual space is used as the indexing key, where similarity values in different features are distinguished by different scale. Then a single indexing tree can be built on these keys. Based on the property that relevant images have similar similarity values from the center of the same local partition in any feature space, certain number of irrelevant images can be fast pruned based on the triangle inequity on indexing keys. To remove the dimensionality curse existing in high dimensional structure, we propose a new technique called Local Bit Stream (LBS). LBS transforms image's text and visual feature representations into simple, uniform and effective bit stream (BS) representations based on local partition's center. Such BS representations are small in size and fast for comparison since only bit operation are involved. By comparing common bits existing in two BSs, most of irrelevant images can be immediately filtered. To effectively integrate multi-features, we also investigated the following evidence combination techniques-Certainty Factor, Dempster Shafer Theory, Compound Probability, and Linear Combination. Our extensive experiment showed that single one-dimensional index on multi-features improves multi-indices on multi-features greatly. Our LBS method outperforms sequential scan on high dimensional space by an order of magnitude. And Certainty Factor and Dempster Shafer Theory perform best in combining multiple similarities from corresponding multiple features.

Advanced computing for systems biology

Systems biology is based on computational modelling and simulation of large networks of interacting components. Models may be intended to capture processes, mechanisms, components and interactions at different levels of fidelity. Input data are often large and geographically disperse, and may require the computation to be moved to the data, not vice versa. In addition, complex system-level problems require collaboration across institutions and disciplines. Grid computing can offer robust, scaleable solutions for distributed data, compute and expertise. We illustrate some of the range of computational and data requirements in systems biology with three case studies: one requiring large computation but small data (orthologue mapping in comparative genomics), a second involving complex terabyte data (the Visible Cell project) and a third that is both computationally and data-intensive (simulations at multiple temporal and spatial scales). Authentication, authorisation and audit systems are currently not well scalable and may present bottlenecks for distributed collaboration particularly where outcomes may be commercialised. Challenges remain in providing lightweight standards to facilitate the penetration of robust, scalable grid-type computing into diverse user communities to meet the evolving demands of systems biology.

From point defects to plate tectonic faults

Understanding and explaining emergent constitutive laws in the multi-scale evolution from point defects, dislocations and two-dimensional defects to plate tectonic scales is an arduous challenge in condensed matter physics. The Earth appears to be the only planet known to have developed stable plate tectonics as a means to get rid of its heat. The emergence of plate tectonics out of mantle convection appears to rely intrinsically on the capacity to form extremely weak faults in the top 100 km of the planet. These faults have a memory of at least several hundred millions of years, yet they appear to rely on the effects of water on line defects. This important phenomenon was first discovered in laboratory and dubbed ``hydrolytic weakening''. At the large scale it explains cycles of co-located resurgence of plate generation and consumption (the Wilson cycle), but the exact physics underlying the process itself and the enormous spanning of scales still remains unclear. We present an attempt to use the multi-scale non-equilibrium thermodynamic energy evolution inside the deforming lithosphere to move phenomenological laws to laws derived from basic scaling quantities, develop self-consistent weakening laws at lithospheric scale and give a fully coupled deformation-weakening constitutive framework. At meso- to plate scale we encounter in a stepwise manner three basic domains governed by the diffusion/reaction time scales of grain growth, thermal diffusion and finally water mobility through point defects in the crystalline lattice. The latter process governs the planetary scale and controls the stability of its heat transfer mode.