Schistosomiasis mansoni in an area of low transmission: I. impact of control measures

This work was undertaken in the municipality of Pedro de Toledo (São Paulo State, Brazil) in 1987, to clarify aspects related to the transmission levels of Schistosoma mansoni in a human population where the snail host is Biomphalaria tenagophila. Since 1980 a control programme has been undertaken in this municipality. Urban and rural populations (4,719 subjects) were submitted to faecal examinations (Kato-Katz method). The overall prevalence rate was 4.8% being higher in males (6.2%) and also in the rural zone (5.8%). The geometric mean of S. mansoni eggs was 35.1 eggs per gramme of faeces (epg). Approximately 80.0% of the carriers presented less than 100 epg and only 20 individuals (9.0%) eliminated more than half of total eggs. The highest index of potencial contamination (IPC) was in the age group of 5 to 20 years (57.6%). Two thirds of the investigated patients (207) were autochthonous of Pedro de Toledo. The geographical distribution of the carriers showed a clear aggregation of the autochthonous cases and a close association between human contact sites and breeding places of B. tenagophila. This study shows that schistosomiasis subjects were not randomly aggregated, the youngsters should be the main target in the prophylaxis, and the efficacy of the control programme.

Mechanical performance of concrete made with aggregates from construction and demolition waste recycling plants

This research aims at analysing the mechanical performance of concrete with recycled aggregates (RA) from construction and demolition waste (CDW) from various locations in Portugal. First the characteristics of the various aggregates (natural and recycled) used in the production of concrete were thoroughly analysed. The composition of the RA was determined and several physical and chemical tests of the aggregates were performed. In order to evaluate the mechanical performance of concrete, compressive strength (in cubes and cylinders), splitting tensile strength, modulus of elasticity and abrasion resistance tests were performed. Concrete mixes with RA from CDW from several recycling plants were evaluated, in order to understand the influence that the RA's collection point, and consequently their composition, has on the characteristics of the mixes produced. The analysis of the mechanical performance allowed concluding that the use of RA worsens most of the properties tested, especially when fine RA are used. On the other hand, there was an increase in abrasion resistance when coarse RA were used. In global terms, the use of this type of aggregates, in limited contents, is viable from a mechanical viewpoint. (C) 2015 Elsevier Ltd. All rights reserved.

Performance of concrete made with aggregates recycled from precasting industry waste: influence of the crushing process

The aim of this paper is to evaluate the influence of the crushing process used to obtain recycled concrete aggregates on the performance of concrete made with those aggregates. Two crushing methods were considered: primary crushing, using a jaw crusher, and primary plus secondary crushing (PSC), using a jaw crusher followed by a hammer mill. Besides natural aggregates (NA), these two processes were also used to crush three types of concrete made in laboratory (L20, L45 e L65) and three more others from the precast industry (P20, P45 e P65). The coarse natural aggregates were totally replaced by coarse recycled concrete aggregates. The recycled aggregates concrete mixes were compared with reference concrete mixes made using only NA, and the following properties related to the mechanical and durability performance were tested: compressive strength; splitting tensile strength; modulus of elasticity; carbonation resistance; chloride penetration resistance; water absorption by capillarity; water absorption by immersion; and shrinkage. The results show that the PSC process leads to better performances, especially in the durability properties.

Physical, chemical and mineralogical properties of fine recycled aggregates made from concrete waste

This paper assesses the physical, chemical and mineralogical characteristics of fine recycled aggregates obtained from crushed concrete waste, comparing them with two types of natural fine aggregates from different origins. A commercial concrete was jaw crushed, and the effect of different aperture sizes on the particle size distribution of the resulting aggregates was evaluated. The density and water absorption of the recycled aggregates was determined and a model for predicting water absorption over time is proposed. Both natural and recycled aggregates were characterized regarding bulk density and fines content. Recycled aggregates were additionally characterized by XRD, SEM/EDS and DTA/TG of individual size fractions. The results show that natural and recycled fine aggregates have very different characteristics. This should be considered in potential applications, both in terms of the limits for replacing amounts and of the rules and design criteria of the manufactured products. (C) 2015 Elsevier Ltd. All rights reserved.

Supervisory control of a variable speed wind turbine with doubly fed induction generator

This paper is on an onshore variable speed wind turbine with doubly fed induction generator and under supervisory control. The control architecture is equipped with an event-based supervisor for the supervision level and fuzzy proportional integral or discrete adaptive linear quadratic as proposed controllers for the execution level. The supervisory control assesses the operational state of the variable speed wind turbine and sends the state to the execution level. Controllers operation are in the full load region to extract energy at full power from the wind while ensuring safety conditions required to inject the energy into the electric grid. A comparison between the simulations of the proposed controllers with the inclusion of the supervisory control on the variable speed wind turbine benchmark model is presented to assess advantages of these controls. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Error control on spectral data of four-wave mixing based on a-SiC technology

In this paper we exploit the nonlinear property of the SiC multilayer devices to design an optical processor for error detection that enables reliable delivery of spectral data of four-wave mixing over unreliable communication channels. The SiC optical processor is realized by using double pin/pin a-SiC:H photodetector with front and back biased optical gating elements. Visible pulsed signals are transmitted together at different bit sequences. The combined optical signal is analyzed. Data show that the background acts as selector that picks one or more states by splitting portions of the input multi optical signals across the front and back photodiodes. Boolean operations such as EXOR and three bit addition are demonstrated optically, showing that when one or all of the inputs are present, the system will behave as an XOR gate representing the SUM. When two or three inputs are on, the system acts as AND gate indicating the present of the CARRY bit. Additional parity logic operations are performed using four incoming pulsed communication channels that are transmitted and checked for errors together. As a simple example of this approach, we describe an all-optical processor for error detection and then provide an experimental demonstration of this idea. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optical processor based on a-SiC technology for spectral data error control

The SiC optical processor for error detection and correction is realized by using double pin/pin a-SiC:H photodetector with front and back biased optical gating elements. Data shows that the background act as selector that pick one or more states by splitting portions of the input multi optical signals across the front and back photodiodes. Boolean operations such as exclusive OR (EXOR) and three bit addition are demonstrated optically with a combination of such switching devices, showing that when one or all of the inputs are present the output will be amplified, the system will behave as an XOR gate representing the SUM. When two or three inputs are on, the system acts as AND gate indicating the present of the CARRY bit. Additional parity logic operations are performed by use of the four incoming pulsed communication channels that are transmitted and checked for errors together. As a simple example of this approach, we describe an all optical processor for error detection and correction and then, provide an experimental demonstration of this fault tolerant reversible system, in emerging nanotechnology.

On performance of distributed model predictive control in power system frequency regulation

This paper describes the implementation of a distributed model predictive approach for automatic generation control. Performance results are discussed by comparing classical techniques (based on integral control) with model predictive control solutions (centralized and distributed) for different operational scenarios with two interconnected networks. These scenarios include variable load levels (ranging from a small to a large unbalance generated power to power consumption ratio) and simultaneously variable distance between the interconnected networks systems. For the two networks the paper also examines the impact of load variation in an island context (a network isolated from each other).

Assessment and control of nanoparticles exposure in welding operations by use of a control banding tool

This paper describes the use of a Control Banding Tool to assess and further control of exposure of nanoparticles emitted during welding operations. The tool was applied to Metal Active Gas (MAG) arc welding of mild and stainless steel, providing semi-quantitative data on the process, so that protection measures could be derived, e.g. exhaust gas ventilation by hoods, local ventilation devices and containment measures. This tool is quite useful to compare and evaluate the characteristics of arc welding procedures so that more eco-friendly processes could be preferred over the more potentially noxious ones.

Choosing amine-based absorbents for CO2 capture

CO2 capture from gaseous effluents is one of the great challenges faced by chemical and environmental engineers, as the increase in CO2 levels in the Earth atmosphere might be responsible for dramatic climate changes. From the existing capture technologies, the only proven and mature technology is chemical absorption using aqueous amine solutions. However, bearing in mind that this process is somewhat expensive, it is important to choose the most efficient and, at the same time, the least expensive solvents. For this purpose, a pilot test facility was assembled and includes an absorption column, as well as a stripping column, a heat exchanger between the two columns, a reboiler for the stripping column, pumping systems, surge tanks and all necessary instrumentation and control systems. Some different aquous amine solutions were tested on this facility and it was found that, from a set of six tested amines, diethanol amine is the one that turned out to be the most economical choice, as it showed a higher CO2 loading capacity (0.982 mol of CO2 per mol of amine) and the lowest price per litre (25.70 ¤/L), even when compared with monoethanolamine, the benchmark solvent, exhibiting a price per litre of 30.50 ¤/L.

Control of predators in industrial scale microalgae cultures with Pulsed Electric Fields.

This work describes the utilization of Pulsed Electric Fields to control the protozoan contamination of a microalgae culture, in an industrial 2.7m3 microalgae photobioreactor. The contaminated culture was treated with Pulsed Electric Fields, PEF, for 6h with an average of 900V/cm, 65μs pulses of 50Hz. Working with recirculation, all the culture was uniformly exposed to the PEF throughout the assay. The development of the microalgae and protozoan populations was followed and the results showed that PEF is effective on the selective elimination of protozoa from microalgae cultures, inflicting on the protozoa growth halt, death or cell rupture, without affecting microalgae productivity. Specifically, the results show a reduction of the active protozoan population of 87% after 6h treatment and 100% after few days of normal cultivation regime. At the same time, microalgae growth rate remained unaffected. © 2014 Elsevier B.V.

The prolonged use of niclosamide as a molluscicide for the control of Schistosoma mansoni

Applications of niclosamide at three-monthly intervals were undertaken for 14 years in foci of Biomphalaria glabrata in the water sources of Peri-Peri (Capim Branco, MG). All the residents of the area were submitted to an annual fecal examination (Kato/Katz) and those individuals eliminating Schistosoma mansoni eggs were treated with oxamniquine. A malacological survey was undertaken at three-monthly intervals by means of ten scoops with a perforated ladle each ten metres along the two banks of the ditches and streams of the region. Where snails were found, molluscicide was applied by means of dripping or aspersion using a 3 ppm aqueous suspension of niclosamide. Initially, a mean of 14.3% of snails in the region were found to be eliminating cercariae. Following the first four applications of molluscicide, this was reduced to 0.0% and maintained at about 1.5% throughout the program. Thus, there was a continued possibility of schistosomiasis transmission in the area and it was observed that the population of snails reestablished itself within three months of molluscicide application. The results obtained in this study do not encourage the continual use of niclosamide as the only method of control of schistosomiasis.

A municipal level approach to the management of schistosomiasis control in Peri-Peri, MG, Brazil

A schistosomiasis control program was implemented between 1974/87 in Peri-Peri,. MG (622 inhabitants). Molluscicide (niclosamide) was applied at three monthly intervals in water sources with Biomphalaria glabrata, and individuals eliminating Schistosoma mansoni eggs in the feces were treated annually with oxamniquine. From 1974 to 1983 the control measures were undertaken by staff of the "René Rachou" Research Center FIOCRUZ (CPqRR), and from 1984 to 1987 these measures were included in the Capim Branco basic health network activities. During both periods, the prevalence, incidence, intensity of infection and hepatosplenic form as well as the number of infected snails decreased significantly. The prevalence decreased from 43.5 to 4.4%, the incidence from 19.0 to 2.9%, the overall intensity of S. mansoni from 281 to 87 and of the hepatosplenic form from 5.9 to 0.0%. The results obtained suggest that the municipal management of control measures was as effective as the vertical program conducted by CPqRR staff.

Prevalência do consumo de drogas ilícitas nas Forças Armadas estudo epidemiológico num dos ramos

RESUMO: Desde 1976 que as Forças Armadas desenvolvem acções de prevenção do consumo de drogas e álcool. Na década de 80 foi criada capacidade laboratorial e deu-se início a um programa de rastreios toxicológicos. No quinquénio 2001 a 2005, as proporções de resultados positivos, associando todos os tipos de rastreio, variaram entre 3,7% e 1,5%. De Outubro de 2006 a Julho de 2007 realizou-se um estudo analítico transversal, para estimar a prevalência do consumo de drogas (canabinóides, opiáceos, cocaína e anfetaminas) num dos Ramos das Forças Armadas, com base nos despistes realizados pelo seu laboratório. Foi utilizada uma amostra aleatória simples de 1039 militares, profissionais (QP) e contratados (RC), no activo e de ambos os sexos. Desde a nomeação dos militares a rastrear, passando pela cadeia de custódia das amostras até à obtenção do resultado foi utilizado apoio informático específico. O processo de pesquisa utilizou duas técnicas de triagem por imunoensaio e tecnologia de confirmação por GC/MS, de acordo com as recomendações europeias, permitindo estabelecer uma metodologia standard para organizações e empresas. A prevalência estimada, de consumidores de droga, foi de 3,8/1.000, para um erro de 0,37%. O número de casos registado (4) não permitiu a utilização de testes estatísticos que conduzissem à identificação de características determinantes da positividade, mas não deixou de revelar aspectos inesperados. A observação de séries de casos e a realização regular de estudos epidemiológicos, que ajudem a redefinir grupos alvo e a perceber a dimensão, as determinantes e as consequências do consumo de drogas é sugerida, em conclusão.--------------------------------------- RÉSUMÉ: Depuis 1976, les Forces Armées mettent au point des mesures visant à prévenir la consommation de drogues et d'alcool. En 1980, fut créé capacité laboratoriel et ont ensuite commencé un programme de dépistage toxicologique. Au cours des cinq années allant de 2001 à 2005, les proportions de consommateurs, impliquant tous les types de dépistage, allaient de 3,7% à 1,5 %. D'octobre 2006 à juillet 2007, une étude analytique transversale a été organisée pour évaluer la prévalence de l’usage de drogues (cannabis, opiacés, cocaïne et amphétamines) dans une branche de les Forces Armées, basée sur les dépistages faites par un laboratoire militaire, à l'aide d'un échantillon aléatoire de 1039 militaires, professionnels (QP) et sous contract (RC), à l’actif et des deux sexes. Tout au long du procès, de la nomination des donneurs, en passant par la chaine de garde des échantillons, jusqu’à obtention du résultat, il fut employé un appui informatique sécurisé. Le processus de recherche employa deux techniques de tri par imunoessay et la technologie de confirmation GC/MS, selon les recommandations européennes, permettant d'établir une méthodologie standard pour les organisations et les entreprises. La prévalence estimée fut de 3,8/1.000 pour une marge d’erreur de 0,37%. Le nombre de cas enregistrés (4) n'autorise pas l'utilisation de testes statistiques de menant à l'identification de caractéristiques déterminant de la positivité, mais il permet à révéler des aspects inattendus. L'observation de séries de cas et la tenue régulière d’études épidémiologiques, qui contribuent à redéfinir les groupes cibles et de comprendre l'ampleur, les déterminants et les conséquences de l'usage de drogues, est suggéré, en fin de compte.--------------------------------------- ABSTRACT: Since 1976, the Armed Forces, have been developing measures to prevent the use of drugs and alcohol. In 1980, was created laboratory facility which then started a program of toxicological screenings. In the five years running from 2001 to 2005, the proportions of consumers, involving all types of screening, ranged from 3,7% to 1,5%. From October 2006 to July 2007, a cross-sectional study was held to estimate the prevalence of drug use (cannabinoids, opiates, cocaine and amphetamines) in one branch of the Portuguese Armed Forces, based on laboratory screenings, using a random sample of 1039 military, professional (QP) and enlisted (RC), active-duty and of both sexes. Specific computer support was used all the way, from the appointment, including the chain of custody of samples, to the obtaining of the result. The process of search used two techniques for sorting by immunoassay and confirmation technology GC/MS, according to European recommendations, allowing to establish a standard methodology for organizations and companies. The estimated prevalence of drug users was 3.8/1.000 for a 0.37% error (95% confidence interval). The number of cases registered (4) does not permit use of statistical testing leading to the identification of characteristics weighing in the establishing to extrapolate for the population, but it allows revealing unexpected aspects. The observation of series of cases and the regular holding of epidemiological studies, which help redefine target groups and to understand the extent, the determinants and consequences of drug use, is suggested, in conclusion.