Lead Retention by Soils at Field Moisture Contents

The majority of studies pertaining to lead retention by clays and soils have examined the mechanisms, kinetics, and adsorption isotherms using the batch experiment technique that employs solid: water extracts of 1:10 and 1:20. Field soil deposits generally have much lower gravimetric water content ranging between 9 and 45%. Given the wide disparity in the solids: water ratio employed in the batch experiment technique and that prevailing in field deposits, this paper examines the lead retention characteristics of soils at field moisture contents (6%, 13%, and 25%) using artificially lead-contaminated soil specimens. A residually derived (i.e., formed by in-situ weathering of parent rock) red soil was used to prepare the artificially contaminated soil specimens. The impact of variations in clay content on lead retention was examined by diluting the residual soil with various amounts (0 to 60%) of river sand. Soil specimens remolded at 6 and 13% moisture contents produced very stiff to hard soils on compaction, while specimens remolded at 25% moisture content existed in the slurry state. The soil specimens were contaminated with low (30mg/kg) to high (2500mg/kg) concentrations of lead ions by remolding them with 160ppm to 10,000ppm ionic lead solutions. Lead retention by soils at field moisture contents was determined by extracting the lead from the soil using a water leach test. Experimental results showed that the bulk (71 to 99%) of the added lead was retained by the soil in insoluble form at the field moisture content. Correlations between the amount of lead retained and soil/solution parameters indicated that the amounts of Pb retained at field moisture content is a function of the initial Pb addition, total sand content, effective clay porosity, and soil pH.

LHC constraints on light neutralino dark matter in the MSSM

Light neutralino dark matter can be achieved in the Minimal Supersymmetric Standard Model if staus are rather light, with mass around 100 GeV. We perform a detailed analysis of the relevant supersymmetric parameter space, including also the possibility of light selectons and smuons, and of light higgsino- or wino-like charginos. In addition to the latest limits from direct and indirect detection of dark matter, ATLAS and CMS constraints on electroweak-inos and on sleptons are taken into account using a ``simplified models'' framework. Measurements of the properties of the Higgs boson at 125 GeV, which constrain amongst others the invisible decay of the Higgs boson into a pair of neutralinos, are also implemented in the analysis. We show that viable neutralino dark matter can be achieved for masses as low as 15 GeV. In this case, light charginos close to the LEP bound are required in addition to light right-chiral staus. Significant deviations are observed in the couplings of the 125 GeV Higgs boson. These constitute a promising way to probe the light neutralino dark matter scenario in the next run of the LHC. (C) 2013 Elsevier B.V. All rights reserved.

`Universal' recession curves and their geomorphological interpretation

The study of recession flows offers fundamental insights into basin hydrological processes and, in particular, into the collective behavior of the governing dominant subsurface flows and properties. We use here an existing geomorphological interpretation of recession dynamics, which links the exponent in the classic recession curve -dQ/dt - kQ(alpha) to the geometric properties of the time-varying drainage network to study the general properties of recession curves across a wide variety of river basins. In particular, we show how the parameter k depends on the initial soil moisture state of the basin and can be made to explicitly depend on an index discharge, representative of initial sub-subsurface storage. Through this framework we obtain a non-dimensional, event-independent, recession curve. We subsequently quantify the variability of k across different basins on the basis of their geometry, and, by rescaling, collapse curves from different events and basins to obtain a generalized, or `universal', recession curve. Finally, we analyze the resulting normalized recession curves and explain their universal characteristics, lending further support to the notion that the statistical properties of observed recession curves bear the signature of the geomorphological structure of the networks producing them. (C) 2014 Elsevier Ltd. All rights reserved.

Basin Scale Water Resources Systems Modeling Under Cascading Uncertainties

Global change in climate and consequent large impacts on regional hydrologic systems have, in recent years, motivated significant research efforts in water resources modeling under climate change. In an integrated future hydrologic scenario, it is likely that water availability and demands will change significantly due to modifications in hydro-climatic variables such as rainfall, reservoir inflows, temperature, net radiation, wind speed and humidity. An integrated regional water resources management model should capture the likely impacts of climate change on water demands and water availability along with uncertainties associated with climate change impacts and with management goals and objectives under non-stationary conditions. Uncertainties in an integrated regional water resources management model, accumulating from various stages of decision making include climate model and scenario uncertainty in the hydro-climatic impact assessment, uncertainty due to conflicting interests of the water users and uncertainty due to inherent variability of the reservoir inflows. This paper presents an integrated regional water resources management modeling approach considering uncertainties at various stages of decision making by an integration of a hydro-climatic variable projection model, a water demand quantification model, a water quantity management model and a water quality control model. Modeling tools of canonical correlation analysis, stochastic dynamic programming and fuzzy optimization are used in an integrated framework, in the approach presented here. The proposed modeling approach is demonstrated with the case study of the Bhadra Reservoir system in Karnataka, India.

Air-pollution and economics: diesel bus versus electric bus

The Bangalore Metropolitan Transport Corporation (BMTC) took an initiative to check the overall benefits of introducing electric buses as a suitable replacement for the diesel buses to tackle the burgeoning pollution in the city of Bengaluru, India. For a trial run of three months, an electric bus was procured from a Chinese company `Build Your Dreams' (BYD). Data were collected by BMTC on the operation and maintenance of the bus. This new initiative, if rightly guided, could have a direct impact on the lives of those in the city. An economic analysis of the running as well as maintenance of the electric buses within the city limits was performed. For comparison, the same analysis was performed for the data from the existing diesel bus operating on the same route. On the basis of the study, it can be concluded that the introduction of electric buses as a means of public transport in the city would be beneficial both economically as well as environmentally. The electric bus also makes much less noise, thereby helping reduce noise pollution and makes less vibration when compared to the diesel bus. This results in a more comfortable journey for the passengers.

Nota acerca de una especimen del género Potamotrygon (Chondrichthyes, Potamotrygonidae).

Its deal with the study of a sample of "river ray" of the Potamotrygonidae family procured in the Colastiné river (Midle Paraná)showing an external morphology relating it closely to two species of said family: Potamotrygon falkneri Castex y Maciel, 1963 and P. menchacai Martínez Achembach, 1965.

Searches for new symmetries in pp collisions with the razor kinematic variables at √s = 7 TeV

The construction and LHC phenomenology of the razor variables M_R, an event-by-event indicator of the heavy particle mass scale, and R, a dimensionless variable related to the transverse momentum imbalance of events and missing transverse energy, are presented.  The variables are used  in the analysis of the first proton-proton collisions dataset at CMS  (35 pb^-1) in a search for superpartners of the quarks and gluons, targeting indirect hints of dark matter candidates in the context of supersymmetric theoretical frameworks. The analysis produced the highest sensitivity results for SUSY to date and extended the LHC reach far beyond the previous Tevatron results.  A generalized inclusive search is subsequently presented for new heavy particle pairs produced in √s = 7 TeV proton-proton collisions at the LHC using 4.7±0.1 fb^-1 of integrated luminosity from the second LHC run of 2011.  The selected events are analyzed in the 2D razor-space of M_R and R and the analysis is performed in 12 tiers of all-hadronic, single and double leptons final states in the presence and absence of b-quarks, probing the third generation sector using the event heavy-flavor content.   The search is sensitive to generic supersymmetry models with minimal assumptions about the superpartner decay chains. No excess is observed in the number or shape of event yields relative to Standard Model predictions. Exclusion limits are derived in the CMSSM framework with  gluino masses up to 800 GeV and squark masses up to 1.35 TeV excluded at 95% confidence level, depending on the model parameters. The results are also interpreted for a collection of simplified models, in which gluinos are excluded with masses as large as 1.1 TeV, for small neutralino masses, and the first-two generation squarks, stops and sbottoms are excluded for masses up to about 800, 425 and 400 GeV, respectively.

With the discovery of a new boson by the CMS and ATLAS experiments in the γ-γ and 4 lepton final states, the identity of the putative Higgs candidate must be established through the measurements of its properties. The spin and quantum numbers are of particular importance, and we describe a method for measuring the J^PC of this particle using the observed signal events in the H to ZZ^* to 4 lepton channel developed before the discovery. Adaptations of the razor kinematic variables are introduced for the H to WW^* to 2 lepton/2 neutrino channel, improving the resonance mass resolution and increasing the discovery significance. The prospects for incorporating this channel in an examination of the new boson J^PC is discussed, with indications that this it could provide complementary information to the H to ZZ^* to 4 lepton final state, particularly for measuring CP-violation in these decays.

Advancing EDL technologies for future space missions : from ground testing facilities to ablative heatshields

Motivated by recent MSL results where the ablation rate of the PICA heatshield was over-predicted, and staying true to the objectives outlined in the NASA Space Technology Roadmaps and Priorities report, this work focuses on advancing EDL technologies for future space missions.

Due to the difficulties in performing flight tests in the hypervelocity regime, a new ground testing facility called the vertical expansion tunnel is proposed. The adverse effects from secondary diaphragm rupture in an expansion tunnel may be reduced or eliminated by orienting the tunnel vertically, matching the test gas pressure and the accelerator gas pressure, and initially separating the test gas from the accelerator gas by density stratification. If some sacrifice of the reservoir conditions can be made, the VET can be utilized in hypervelocity ground testing, without the problems associated with secondary diaphragm rupture.

The performance of different constraints for the Rate-Controlled Constrained-Equilibrium (RCCE) method is investigated in the context of modeling reacting flows characteristic to ground testing facilities, and re-entry conditions. The effectiveness of different constraints are isolated, and new constraints previously unmentioned in the literature are introduced. Three main benefits from the RCCE method were determined: 1) the reduction in number of equations that need to be solved to model a reacting flow; 2) the reduction in stiffness of the system of equations needed to be solved; and 3) the ability to tabulate chemical properties as a function of a constraint once, prior to running a simulation, along with the ability to use the same table for multiple simulations.

Finally, published physical properties of PICA are compiled, and the composition of the pyrolysis gases that form at high temperatures internal to a heatshield is investigated. A necessary link between the composition of the solid resin, and the composition of the pyrolysis gases created is provided. This link, combined with a detailed investigation into a reacting pyrolysis gas mixture, allows a much needed consistent, and thorough description of many of the physical phenomena occurring in a PICA heatshield, and their implications, to be presented.

Through the use of computational fluid mechanics and computational chemistry methods, significant contributions have been made to advancing ground testing facilities, computational methods for reacting flows, and ablation modeling.

Water quality objectives as a management tool for sustainability

The aim of this paper is to explore the potential role that quality objectives, particularly when backed by statutory force, may play in the sustainable management of river water quality. Economic valuation techniques are discussed, as well as the theory of "critical natural capital". A brief history of water quality legislation includes the implementation of the National Water Council classification in 1979, and the statutory water quality objectives introduced under the Water Resources Act 1991.

Valley evolution by meandering rivers

Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing—which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them—including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these terraces from terraces formed by externally forced pulses of vertical incision. In a separate study, Chapter 5 utilizes image and topographic data from the Mars Reconnaissance Orbiter to quantitatively identify spatial structures in the polar layered deposits of Mars, and identifies sequences of beds, consistently 1-2 meters thick, that have accumulated hundreds of kilometers apart in the north polar layered deposits.

Upland hill farming for water, wildlife and food

The economic, environmental and social benefits of more sensitive land use practices that protect or restore the natural functions of river catchments have been widely discussed. Changing land use has implications for a wide range of other biological communities. Some studies have already been undertaken on the benefits of sensitive farming at the catchment scale in England and Wales. However, there is a gap in these studies at the local scale, and particularly for upland farms from which headwaters arise. This article documents a case study relating to a successful partnership in Cumbria, UK, set within the wider context of catchment management. Whilst the case study is not highly detailed, and some costs have been described in outline only to protect confidentiality and commercial sensitivity, it provides some generic lessons and may therefore be useful in informing more sustainable policy-making. High Hullockhowe Farm near Haweswater, which was used a the case study highlighting changes in farm practise, costs and benefits, water resources and biodiversity. The authors relate the case study to wider policy implications.

Caracterização espaço-temporal de plumas de sedimentos por sensoriamento remoto: um estudo de caso na foz do rio Paraíba do Sul.

Sedimentos em suspensão representam um dos principais fatores que afetam a qualidade dos sistemas aquáticos no mundo; influenciam os processos geomórficos de construção da paisagem e podem indicar problemas de erosão e perda de solo na bacia hidrográfica contribuinte. O seu monitoramento espacial e temporal é fundamental nas atividades de gestão ambiental de áreas costeiras. Nesse sentido, a hipótese básica desta pesquisa é que o padrão espacial e temporal de plumas de sedimentos costeiras associado ao regime hidrológico do rio pode ser caracterizado a partir de imagens orbitais de média resolução espacial. Para comprová-la, elegeu-se a foz do rio Paraíba do Sul como área de estudo para definição e teste metodológico, e formulou-se como principal objetivo mapear qualitativamente a pluma costeira deste rio a partir de imagens Landsat 5 e CBERS-2, ao longo do período compreendido entre 1985 e 2007. As datas avaliadas foram criteriosamente definidas através de três estratégias de análise, totalizando cinqüenta imagens. Pesquisa bibliográfica e avaliação da resposta espectral da feição de interesse nas imagens selecionadas consistiram nas etapas principais da definição da metodologia. As plumas foram então identificadas, mapeadas e extraídas; posteriormente, suas características espaciais e temporais foram analisadas por intermédio de sistemas de informação geográfica e avaliadas em conjunto com dados históricos de vazão. Os resultados indicam que a banda do vermelho forneceu uma melhor discriminação interna da pluma, sendo, portanto, utilizada como base para as análises realizadas neste trabalho. Com exceção do procedimento de correção atmosférica, a metodologia proposta consiste na utilização de técnicas simples de processamento digital de imagens, baseadas na integração de técnicas semi-automáticas e de análise visual. A avaliação do padrão dos sedimentos e dos mapas temáticos qualitativos de concentração de sedimentos em suspensão indica a forte diferenciação existente entre cenários representativos de épocas de cheia e seca do rio. Análises espaciais do comportamento da pluma contribuem ainda para um maior conhecimento do espaço geográfico, fornecendo subsídios aos mais variados setores do planejamento e gestão ambiental.

Using RIVPACS for studies on conservation and biodiversity

Invertebrate conservation relies not only on public support and political will, but also on possessing an adequate understanding of the distribution and ecology of invertebrate species and communities. In the UK, RIVPACS is making an important contribution to assessing the conservation importance of river invertebrate assemblages. So far, work has largely centred on using RIVPACS as an integral part of SERCON (System for Evaluating Rivers for Conservation), in which data collected using the standard RIVPACS method are interpreted with reference to conservation criteria such as species richness and representativeness. Applications of RIVPACS to other areas of conservation - whether providing information on the ecological requirements of rare species, monitoring the success of river restoration projects, or making broader assessments of sustainability - are probably more limited, but merit further examination. It is important to develop closer links between RIVPACS and techniques such as SERCON and RHS (River Habitat Survey) in order to maximise the benefit each can bring tostudies on conservation and biodiversity. It should also be recognised that there are limitations in transferring such systems to other countries where approaches to nature conservation may be very different.

Estudo do efeito das cargas de nutrientes no reservatório APM-Manso: uma abordagem através da modelagem numérica tridimensional.

Os gestores de recursos hídricos estão encarregados da gestão de longo prazo, a regulação e a proteção dos recursos hídricos. No entanto, reconhece-se que a estes gestores devem levar em conta a multiplicidade de usos dos recursos hídricos que são apresentadas pelas partes interessadas, tais como agricultores, fornecedores de água e grupos de ambientalistas. Dada a complexidade do sistema hidrológico, o desenvolvimento e a utilização de modelos matemáticos são muitas das vezes necessários. Neste contexto a modelagem ambiental é frequentemente realizada para avaliar os impactos da degradação do ecossistema devido à ação humana. Essa aplicação orientada a investigações proporciona um importante meio pelo qual os cientistas podem interagir e influenciar nas políticas a nível local, regional, nacional e internacional. No Mato Grosso, durante a implantação da hidroelétrica de Aproveitamento Múltiplo de Manso foram adotadas medidas de mitigação dos impactos socioeconômicos causados. Essas medidas geram uma tendência de aumento populacional associado a uma mudança das características sócio-econômicas, para toda a região do entorno do Reservatório, o que agrava o problema de poluição por nutrientes e denota que existe uma necessidade proeminente de estudos do impacto que estas cargas causariam no ecossistema do reservatório. Utilizando o modelo hidrodinâmico e termodinâmico tridimensional ELCOM, associado ao modelo biogeoquímico Caedym, este trabalho tem a finalidade de criar uma modelagem representativa das cargas dos principais nutrientes causadores da eutrofização cultural, sendo eles: a amônia (NH4), o nitrato (NO3) e o Ortofosfato (PO4), com a finalidade de estudar os efeitos das dinâmicas espaciais e temporais destas cargas no estado trófico deste reservatório no em torno dos pontos de lançamento de esgoto e na sua totalidade.

A degradação ambiental de bacias hidrográficas urbanas e as políticas públicas no Município de São Gonçalo/RJ

No presente trabalho, buscou-se identificar os conflitos de interesses existentes nos três níveis do poder executivo que dificultam a gestão integrada de políticas públicas voltadas para a recuperação ambiental dos rios urbanos, considerando-se, como área de estudo, o Município de São Gonçalo (RJ). A pesquisa exploratória consistiu em revisão bibliográfica e trabalho empírico. No referencial teórico de análise, abordou-se a formação do Estado brasileiro, as políticas públicas e as relações de poder entre os agentes na tomada de decisão e na administração da coisa pública. Através de revisão na literatura, levantou--se o contexto histórico da ocupação e da degradação dos rios de São Gonçalo e da Baixada Fluminense, os planos e projetos para o setor de saneamento da região, bem como se empreendeu a compilação das normas legais pertinentes à gestão do território, aos recursos hídricos e ao saneamento. O trabalho de campo consistiu em levantamento de dados sobre a degradação das bacias hidrográficas no Município de São Gonçalo e das inter-relações existentes nas políticas públicas referentes à Região Hidrográfica da Bacia da Baía de Guanabara, onde o município em comento se insere. O estudo do caso evidenciou que a degradação dos rios urbanos é resultante, entre outros fatores, da falta de articulação das três esferas de governo, da descontinuidade das ações públicas, de interesses políticos e financeiros desarticulados das demandas socioambientais, da falta de infraestrutura técnica e financeira dos municípios, da pouca participação social no planejamento e tomada de decisões face às relações desiguais de poder, além da inconsistência e desarticulação dos planos e projetos governamentais, a exemplo dos planos diretores de uso ocupação do solo. Conclui-se ser fundamental o fortalecimento dos comitês de bacia e das instituições que os integram, possibilitando a articulação entre as políticas públicas municipais e as do governo estadual e federal, em relação às condicionantes ambientais, bem como ao uso do solo e ao saneamento. A solução dos problemas relativos aos rios urbanos só será possível através da gestão integrada e participativa, envolvendo efetivamente os diferentes setores usuários da bacia hidrográfica. O controle social das ações é imprescindível para manter a coerência, a efetividade, a eficácia e a continuidade dos planos, projetos e políticas do Estado. Assim, poderá ser contido o processo contínuo de degradação ambiental, em particular, dos recursos hídricos em bacias urbanas como acontece no Município de São Gonçalo e em diversos outros municípios brasileiros. Espera-se que esse estudo contribua para o aprimoramento do conhecimento e de soluções no que concerne à morte iminente dos rios urbanos do país.