Servi��os dos ecossistemas prestados pelos estu��rios : especia����o e capacidade de reten����o do f��sforo

O fator nutricional presente nos sapais n��o �� s�� importante para os organismos que nele habitam como tamb��m apresenta uma import��ncia ecol��gica a uma maior escala. Exemplifica-se este fato com a capacidade de reten����o do F��sforo (P) por parte das plantas podendo estas competir como produto qu��micos para sua imobiliza����o atrav��s da incorpora����o da sua fra����o biodispon��vel para cumprimento dos mecanismos b��sicos de sobreviv��ncia. O rizosedimento dessas plantas �� uma importante fonte de nutrientes necess��rios para garantia b��sica da perpetua����o de todos os servi��os (regula����o, provis��o, cultural) gerados pelo ambiente. A perda de ��reas de sapal foi o motivo principal para a elabora����o desta tese visto a preocupa����o em rela����o aos impactes que a perda de servi��os associados �� ��rea de estudo escolhida, o sistema lagunar da Ria de Aveiro, poder�� vir sofrer caso aconte��am altera����es h��dricas (naturais ou antr��picas) mais acentuadas no futuro. Essa tese assume como compromisso chamar a aten����o para essa quest��o como tamb��m investigar os mecanismos do ciclo do P este importante nutriente considerado essencial para a manuten����o da vida em nosso planeta. Para este estudo foram escolhidas 3 esp��cies de plantas hal��fitas representantes do sapal amostral, s��o elas: Bolbochenous maritimus, Spartina maritima e de Juncus maritimus. As quest��es levantadas buscam compreender o papel do P nas transforma����es que ocorrem no rizosedimento das hal��fitas em 3 diferentes contextos: (i) quando comparados os valores da biomassa de P associado ��s hal��fitas estudadas (estudo realizado nos sapais povoados por Spartina maritima e Juncus maritimus) em toda extens��o da Ria de Aveiro (ii) quando da disponibilidade de P perante a presen��a de poluentes inorg��nicos no Largo do Laranjo, que corresponde a uma zona historicamente contaminada por metais (estudo realizado no rizosedimento das esp��cies Bolbochenous maritimus e Juncus maritimus) e (iii) quanto �� intrus��o superficial da ��gua salgada da laguna (estudo focado na avalia����o da perda do P pr��ximo ��s ra��zes das hal��fitas que habitam a zona externa do dique do Baixo Vouga Lagunar (BVL) que corresponde �� zona de conflu��ncia do Rio Vouga com a Ria de Aveiro). Por meio da an��lise do rizosedimento e da biomassa das diferentes hal��fitas predominantes do sapal foi poss��vel verificar que, em rela����o �� carga nutritiva fosf��tica, de Norte (Canal de S��o Jacinto/Ovar) a Sul (Canal de Mira) da Ria de Aveiro, a cota do sapal �� mais importante do que a natureza espacial do sistema. Esta informa����o �� primordial para a assertividade de futuras medidas de cria����o e reabilita����o das ��reas de sapal na Ria de Aveiro. Os estudos realizados nas ��reas impactadas (Largo do Laranjo e BVL) incidiram na an��lise do perfil vertical rizosedimentar das hal��fitas pertencentes ao sapal m��dio-alto. Estes estudos revelaram que o rizosedimento dessas hal��fitas possui caracter��sticas peculiares que definem a din��mica do ciclo do P de forma bastante caracter��stica. O rizosedimento das hal��fitas presentes no Largo do Laranjo apresentaram teores biodispon��veis de P equivalentes ��queles presentes no rizosedimento de ��rea mais afastada da fonte pontual de contamina����o para as mesmas esp��cies. Numa vis��o otimista, os resultados revelam que ambos sapais, Largo de Laranjo e Cais do Bico, apresentam condi����es equipar��vel para perpetua����o dos servi��os por eles gerados, que nesse caso se tornam ainda mais valiosos devido a garantia da fitoestabiliza����o dos contaminantes (preven����o da entrada de contaminantes na coluna d�����gua e na cadeia alimentar). No Baixo Vouga Lagunar a an��lise espacial do sapal na zona exterior ao dique revelou a perda da diversidade das esp��cies bem como o aumento da ��rea de vasa e consequentemente a perda dos teores de P associados ao rizosedimento das hal��fitas mais expostas aos efeitos da compress��o costeira intensificados pelas a����es naturais e antr��picas a que a Ria est�� sujeita. Em geral, a degrada����o dessa ��rea de sapal devido aos fen��menos de assoreamento ou de eros��o n��o pode ser separada dos processos sedimentares na ��rea envolvente, principalmente no caso da Ria de Aveiro que tem sofrido constantes mudan��as para atender ��s necessidades das atividades humanas. Essa tend��ncia provavelmente n��o mudar�� no futuro pr��ximo. Consequentemente, a evolu����o da laguna ser�� principalmente dependente do resultado direto das a����es humanas que dever��o sempre encontrar formas de compensar os danos causados no ��mbito de interven����es de reabilita����o do sistema h��drico. A recria����o de ��reas de sapal pode ter lugar como medida mitigadora no ��mbito de interven����es de reabilita����o de ��reas degradadas e ainda poder�� servir como forma de captura de P para programas de utiliza����o de fertilizantes naturais (componente desej��vel para a agricultura moderna o que �� particularmente importante para as regi��es altamente dependentes do mercado de importa����o). Deste modo, recomenda-se que a recupera����o das ��reas de sapal seja enquadrada no ��mbito de interven����es mais amplas de valoriza����o dos sistemas estuarinos e lagunares.

Tracking the attenuation and nonbreaking dissipation of swells using altimeters

A method for systematically tracking swells across oceanic basins is developed by taking advantage of high-quality data from space-borne altimeters and wave model output. The evolution of swells is observed over large distances based on 202 swell events with periods ranging from 12 to 18 s. An empirical attenuation rate of swell energy of about 4 �� 10���7 m���1 is estimated using these observations, and the nonbreaking energy dissipation rates of swells far away from their generating areas are also estimated using a point source model. The resulting acceptance range of nonbreaking dissipation rates is ���2.5 to 5.0 �� 10���7 m���1, which corresponds to a dissipation e-folding scales of at least 2000 km for steep swells, to almost infinite for small-amplitude swells. These resulting rates are consistent with previous studies using in-situ and synthetic aperture radar (SAR) observations. The frequency dispersion and angular spreading effects during swell propagation are discussed by comparing the results with other studies, demonstrating that they are the two dominant processes for swell height attenuation, especially in the near field. The resulting dissipation rates from these observations can be used as a reference for ocean engineering and wave modeling, and for related studies such as air-sea and wind-wave-turbulence interactions.

Desenvolvimento e valida����o de m��todo para determina����o do perfil graxo do biodiesel de Tungue e Blendas com soja empregando GC-MS

No Brasil o biodiesel �� utilizado em misturas com ��leo diesel em propor����es de 5%, sem que haja modifica����es nos motores. Com o intuito de diversificar a utiliza����o de oleaginosas n��o comest��veis no ramo dos biocombust��veis, e ainda vincular a produ����o com agricultura sustent��vel, uma alternativa para o RS �� a utiliza����o do ��leo de tungue para a produ����o de biodiesel. A caracteriza����o e quantifica����o de ��cidos graxos do biodiesel de tungue, torna-se importante devido �� seu exclusivo perfil graxo. Neste trabalho, foi estudado o desenvolvimento e valida����o de m��todo para a determina����o do perfil graxo do biodiesel met��lico de tungue e blendas com soja utilizando GC-MS. Os par��metros de valida����o considerados foram: curva anal��tica, linearidade, seletividade, limite de detec����o e quantifica����o, robustez, precis��o e exatid��o. Para determinar as melhores condi����es cromatogr��ficas, foram testadas diferentes programa����es de temperatura no forno cromatogr��fico; fluxo de g��s; temperatura do injetor, detector e interface; e modo de inje����o. As condi����es do GCMS ap��s a otimiza����o foram: inje����o de 1 ��L com inje����o em alta press��o (300 kPa), T do injetor: 250 ��C, inje����o split 1:30, fluxo de 1 mL min-1, coluna Rtx-5MS com dimens��es 30 m x 0,25 mm x 0,25 ��m, T forno: isoterma de 2 min a 130 ��C, aumento de 20 ��C/min at�� 220 ��C, aumento de 0,5��C/min at�� 223��C, aumento de 7 ��C/min at�� 250 ��C e isoterma em 250 ��C por 3 min, resultando em 20 min de an��lise. A temperatura da fonte e interface foram de 200 ��C e 250 ��C, respectivamente, com o MS no modo full scan, ioniza����o por impacto eletr��nico a 70 eV, e intervalo de massas de 30 a 500 u.m.a. A identifica����o do ��-eleoste��rico foi baseada na fragmenta����o caracter��stica do composto, pela compara����o com o espectro do ��cido linol��nico, e ainda pelo tempo de reten����o do composto. Na valida����o, as curvas anal��ticas apresentaram valores de r maiores que 0,99. O LD e LQ foram adequados, permitindo a quantifica����o de ��steres na concentra����o m��nima de 0,6%. Os valores de exatid��o ficaram entre 86 e 117%, com RSD% menores que 8%. O efeito matriz tamb��m foi avaliado, sendo que esse efeito foi considerado m��dio para a maioria dos compostos, ficando entre �� 20 e 50%. Durante a aplica����o do m��todo, o mesmo se mostrou adequado para amostras de biodiesel met��lico de tungue e blendas com soja, nas propor����es de 15:85, 20:80 e 25:75 (T:S, v/v). A aplicabilidade do m��todo tamb��m foi testada para o biodiesel de soja, obtendo resultados satisfat��rios, mostrando-se assim, al��m de tudo, ser um m��todo robusto.

Recent educational changes at higher educational level in Pakistan: English language teachers' perceptions and practices

Higher Education Institutes (HEIs) of any country could be a source of providing professionals to the country in many fields. By doing so, HEIs could play a pivotal role in the economic growth of the country. In Pakistan, it seems that, in the wake of this realization, steps have been taken to reform Higher Education. Drawing on the Triple I model of educational change covering Initiation, Implementation and Institutionalization (Fullan, 2007) this study focuses on the planning and implementation of reforms in the Education system of Pakistan at higher education level that have been introduced by the Higher Education Commission (HEC) since its inception in 2002. Kennedy���s model of hierarchical subsystems affecting innovation and Chin and Benne���s (1985) description of strategies for implementing change also provided guidelines for analyzing the changes in education in the country to highlight the role that the authorities expect the language teacher to play in the process of implementing these changes. A qualitative method is followed in this study to gather data from English language teachers at three universities of the Khyber Pakhtunkhwa province of Pakistan. A questionnaire was developed to look into the perceptions of English language teachers regarding the impact of these reforms. This was followed up by interviews. Responses from 28 teachers were received through questionnaire out of which 9 teachers were interviewed for detailed analysis of their perceptions. Thematic Content analysis was used to analyze and interpret the data. Some of the most significant changes that the respondents reported knowledge of included the introduction of Semester System, extending the Bachelors degree to four years from two years, promotion of research culture, and increased teachers��� autonomy in classroom practices. Implications of these reforms for English teachers��� professional development were also explored. The data indicate that the teachers generally have a positive attitude towards the changes. However, the data also show concerns that teachers have about the practical effectiveness of these changes in improving English language teaching and learning in Pakistani Universities. Some of the areas of concern are worries regarding resources, the assessment system, the number of qualified teachers, and instability in the educational policy. They are concerned about the training facilities and quality of the professional training available to them. Moreover, they report that training opportunities for their professional development are not available to all the teachers equally. Despite the HEC claims of providing regular training opportunities, the majority of the teachers did not receive any formal training in the last three years, while some teachers were able to access these opportunities multiple times. Through the recent reforms HEC has empowered the teachers in conducting the learning/teacher processes but this extra power has reduced their accountability and they can exercise these powers without any check on them. This empowerment is limited to the classroom and there appears to be no or minimal involvement in decision making at the top level of policy making. Such lack of involvement in the policy decisions seems to be generating a lack of sense of ownership among the teachers (Fullan 2003a:6). Although Quality Enhancement Cells have been developed in the universities to assure the desired quality of education, they might need a more active role to contribute in achieving the level of enhancement in education expected from them. Based on the perceptions of the respondents of this study and the review of the relevant literature, it is argued that it is unlikely for the reforms to be institutionalized if teachers are not given the right kind of awareness at the initiation stage and are not prepared at the implementation stage to cope with the challenge of a complex process. The teachers participating in this study, in general, have positive and enthusiastic attitudes towards most of the changes, in spite of some reservations. It could also be interesting to see if the power centers of the Pakistani Higher Education appreciate this enthusiasm and channel it for a strong Higher Education system in the country.

Appraisal of open software for finite element simulation of 2D metal sheet laser cut.

FEA simulation of thermal metal cutting is central to interactive design and manufacturing. It is therefore relevant to assess the applicability of FEA open software to simulate 2D heat transfer in metal sheet laser cuts. Application of open source code (e.g. FreeFem++, FEniCS, MOOSE) makes possible additional scenarios (e.g. parallel, CUDA, etc.), with lower costs. However, a precise assessment is required on the scenarios in which open software can be a sound alternative to a commercial one. This article contributes in this regard, by presenting a comparison of the aforementioned freeware FEM software for the simulation of heat transfer in thin (i.e. 2D) sheets, subject to a gliding laser point source. We use the commercial ABAQUS software as the reference to compare such open software. A convective linear thin sheet heat transfer model, with and without material removal is used. This article does not intend a full design of computer experiments. Our partial assessment shows that the thin sheet approximation turns to be adequate in terms of the relative error for linear alumina sheets. Under mesh resolutions better than 10e���5 m , the open and reference software temperature differ in at most 1 % of the temperature prediction. Ongoing work includes adaptive re-meshing, nonlinearities, sheet stress analysis and Mach (also called ���relativistic���) effects.

Macroeconomic rates of return of public and private investment : crowding-in and crowding-out effects

Using annual data from 14 European Union countries, plus Canada, Japan and the United States, we evaluate the macroeconomic effects of public and private investment through VAR analysis. From impulse response functions, we are able to assess the extent of crowding-in or crowding-out of both components of investment. We also compute the associated macroeconomic rates of return of public and private investment for each country. The results point mostly to the existence of positive effects of public investment and private investment on output. On the other hand, the crowding-in effects of public investment on private investment vary across countries, while the crowding-in effect of private investment on public investment is more generalised.

De la captaci��n ilegal de dinero en Colombia. An��lisis de la pol��tica y protecci��n de la Superintendencia Financiera

45 p.

Ecologia do fitopl��ncton em ��reas de cultivo de Til��pia do Nilo, Oreochromis niloticus, em tanques-rede no a��ude Ministro Jo��o Alves, Parelhas, Rio Grande do Norte

The dams are limnic ecosystems of great importance for its multiple uses, among them, water supply for the public and to culture of artisanal fish are most relevant. The aim of the present study is to evaluate the physical-chemical characteristics and the phytoplankton community in two chosen sites (Point 1 littoral zone of point source; Point 2 pelagic zone of non-point source) of the Minister Jo��o Alves dam, which is also known as Boqueir��o de Parelhas/RN. This represents the spatial distribution of the phytoplankton species in order to understand any possible alterations of the water quality and the phytoplankton composition in relation to the water quality originating from the impact of the tilapia, Oreochromis niloticus, culture. The study period also encompasses temporal variations exhibited in two seasons of an annual cycle, one during the dry season (Oct, Nov and Dec of 2008 and Jan of 2009), and the other rainy season (Mar, Apr, May and June of 2008) to extend the observation. The physicalchemical parameters, such as pH, temperature, electrical conductivity, concentration of dissolved oxygen were measured in situ and the values of the inorganic nutrients (nitrate, ammonium and orto-phosfato) and chlorophyll in the laboratory. The quali-quantitative analyses of the phytoplankton had been carried through sedimentation technique and the enumeration of the random of 400 cells, colonies and filaments counted using Sedgwick-Rafter counting chamber. The results of pH varied widely from the acidic to alkaline range with the minimum of 5.8 (�� 0.8) and the maximum of 9.2 (�� 0.7-0.8), at point 1 and 2. The dissolved oxygen content was higher in the rainy period than that in the dry period. The maximum electrical conductivity was of 1409 ��Scm-1 in point 1 and 431 minim of ��Scm-1, in point 2. There was a considerable alteration in the levels of inorganic nutrients such as nitrate-nitrogen, ammoniacal nitrogen and orthophosphate during the two cycles of study period. Phytoplankton assemblages presented a picture of alternate dominance among species Cyanobacteria, Bacillariophyceae and Chlorophyceae. The trophic state index diagnosed to the category of mesotrophic, which is based on the values of chlorophyll, total phosphorus and Secchi-disc measurements. The wind driven turbulence of the water column and the fresh inflow of water (flushing and dilution) during rainy season acted as constraint and did-not allow an exaggerated growth of the species of cyanobacteria. On the basis of the present we conclude that the culture of tilapias in cage-culture fails to produce pollution load that could compromise the quality of the water of the dam, probably be due to small dimension of the culture in relation to the size, volume of the water and the reservoir capacity support its own environment

Hydro-Physical Characterization of Media Used in Agricultural Systems to Develop the Best Management Practices for operation of an Environmentally Sustainable Agricultural Enterprise

Florida is the second leading horticulture state in the United States with a total annual industry sale of over $12 Billion. Due to its competitive nature, agricultural plant production represents an extremely intensive practice with large amounts of water and fertilizer usage. Agrochemical and water management are vital for efficient functioning of any agricultural enterprise, and the subsequent nutrient loading from such agricultural practices has been a concern for environmentalists. A thorough understanding of the agrochemical and the soil amendments used in these agricultural systems is of special interest as contamination of soils can cause surface and groundwater pollution leading to ecosystem toxicity. The presence of fragile ecosystems such as the Everglades, Biscayne Bay and Big Cypress near enterprises that use such agricultural systems makes the whole issue even more imminent. Although significant research has been conducted with soils and soil mix, there is no acceptable method for determining the hydraulic properties of mixtures that have been subjected to organic and inorganic soil amendments. Hydro-physical characterization of such mixtures can facilitate the understanding of water retention and permeation characteristics of the commonly used mix which can further allow modeling of soil water interactions. The objective of this study was to characterize some of the locally and commercially available plant growth mixtures for their hydro-physical properties and develop mathematical models to correlate these acquired basic properties to the hydraulic conductivity of the mixture. The objective was also to model the response patterns of soil amendments present in those mixtures to different water and fertilizer use scenarios using the characterized hydro-physical properties with the help of Everglades-Agro-Hydrology Model. The presence of organic amendments helps the mixtures retain more water while the inorganic amendments tend to adsorb more nutrients due to their high surface area. The results of these types of characterization can provide a scientific basis for understanding the non-point source water pollution from horticulture production systems and assist in the development of the best management practices for the operation of environmentally sustainable agricultural enterprise

Properties of a method of fundamental solutions for the parabolic heat equation

We show that a set of fundamental solutions to the parabolic heat equation, with each element in the set corresponding to a point source located on a given surface with the number of source points being dense on this surface, constitute a linearly independent and dense set with respect to the standard inner product of square integrable functions, both on lateral- and time-boundaries. This result leads naturally to a method of numerically approximating solutions to the parabolic heat equation denoted a method of fundamental solutions (MFS). A discussion around convergence of such an approximation is included.

SAFARI optical system architecture and design concept

SpicA FAR infrared Instrument, SAFARI, is one of the instruments planned for the SPICA mission. The SPICA mission is the next great leap forward in space-based far-infrared astronomy and will study the evolution of galaxies, stars and planetary systems. SPICA will utilize a deeply cooled 2.5m-class telescope, provided by European industry, to realize zodiacal background limited performance, and high spatial resolution. The instrument SAFARI is a cryogenic grating-based point source spectrometer working in the wavelength domain 34 to 230 ��m, providing spectral resolving power from 300 to at least 2000. The instrument shall provide low and high resolution spectroscopy in four spectral bands. Low Resolution mode is the native instrument mode, while the high Resolution mode is achieved by means of a Martin-Pupplet interferometer. The optical system is all-reflective and consists of three main modules; an input optics module, followed by the Band and Mode Distributing Optics and the grating Modules. The instrument utilizes Nyquist sampled filled linear arrays of very sensitive TES detectors. The work presented in this paper describes the optical design architecture and design concept compatible with the current instrument performance and volume design drivers.

Iowa Nutrient Reduction Strategy 2013-2014 annual progress report (From Strategy Release through May 30th, 2014)

The Nutrient Reduction Strategy Annual Progress Report is assigned to the Water Resources Coordinating Council and follows the Iowa Nutrient Reduction Strategy (NRS) ( nutrientstrategy.iastate.edu ) framework that is based on EPA recommendations provided in their March 16, 2001 memo, ���Working in Partnership with States to Address Phosphorus and Nitrogen Pollution through Use of a Framework for State Nutrient Reduction.��� The annual report provides progress updates on point source and nonpoint source efforts related to the action items listed in the elements of the strategy and updates on implementation activities to achieve reductions in nitrogen and phosphorus loads.

Iowa Nutrient Reduction Strategy 2014-2015 annual progress report. Reporting period: June 1, 2014 through May 30, 2015

The Nutrient Reduction Strategy Annual Progress Report is compiled by the three lead agencies (Iowa Department of Agriculture and Land Stewardship, Iowa Department of Natural Resources and Iowa State University) of the Iowa Nutrient Reduction Strategy and presented to the Water Resources Coordinating Council. The report follows the Iowa Nutrient Reduction Strategy (NRS) (nutrientstrategy.iastate.edu) framework that is based on EPA recommendations provided in their March 16, 2011 memo, ���Working in Partnership with States to Address Phosphorus and Nitrogen Pollution through Use of a Framework for State Nutrient Reduction.��� The annual report provides progress updates on point source and nonpoint source efforts related to the action items listed in the elements of the strategy and updates on implementation activities to achieve reductions in nitrogen and phosphorus loads.

Characterization of verdete rock as a potential source of potassium

Potassium is a nutrient found at low levels in Brazilian soils, requiring large inputs of fertilizers to achieve satisfactory crop yields. Brazil has high external dependence and limited reserves of soluble K mineral, which is traditionally exploited for the production of fertilizers. On the other hand, it is common the occurrence in the country of potassium-rich silicate minerals which are not commercially exploited. This study aimed to characterize mineralogically and chemically samples of verdete rock separated into size fractions and evaluate its potential as potassium fertilizer. The mineral composition of verdete rock is based on glauconite, quartz and feldspar. The total K2O content in verdete rock ranged from 5.18 to 9.0 dag/kg. The K content extracted in water or 2% citric acid was 2.4% below the total of K, indicating low reactivity of verdete rock and limitations for direct use as K source. The processes of physical fractionation and sedimentation in water are inefficient to promote the concentration of K in the different verdete rock fractions. The total K content in some samples are considerable and may enable the use of this rock as raw material for production of more reactive potassium fertilizers.

Predictive control of a current-source inverter for solar photovoltaic grid interface

Solar photovoltaic systems are an increasing option for electricity production, since they produce electrical energy from a clean renewable energy resource, and over the years, as a result of the research, their efficiency has been increasing. For the interface between the dc photovoltaic solar array and the ac electrical grid is necessary the use of an inverter (dc-ac converter), which should be optimized to extract the maximum power from the photovoltaic solar array. In this paper is presented a solution based on a current-source inverter (CSI) using continuous control set model predictive control (CCS-MPC). All the power circuits and respective control systems are described in detail along the paper and were tested and validated performing computer simulations. The paper shows the simulation results and are drawn several conclusions.