Preparação e avaliação de resinas biocidas impregnadas com iodo a partir de resinas comerciais de estireno e divinilbenzeno

Neste trabalho, foram empregadas duas resinas comerciais de caráter fortemente básico. Ambas tendo como base copolímeros de estireno e divinilbenzeno (DVB), sendo que a VPOC 1950 contém em sua composição grupos quaternários de amônio do tipo 1, que apresentam três grupos metila e a VPOC 1960 grupos quaternários de amônio do tipo 2, que apresentam um grupo etanoíla e dois grupos metila. As resinas comerciais citadas foram escolhidas por apresentarem grande capacidade de troca iônica, estabilidade e grupos funcionais de interesse para a impregnação com iodo. As resinas foram impregnadas com iodo por meio de três metodologias distintas, uma solução metanólica de iodo 0,08 mol/L com e sem iodeto de potássio 0,14 mol/L, e iodo 0,08 mol/L em heptano. As resinas foram caracterizadas por área específica, volume do poro, grau de inchamento, microscopia ótica, espectrometria de infravermelho por transformada de Fourier (FTIR), análise elementar, termogravimetria, microscopia eletrônica de varredura e determinação do iodo fixado por iodometria. A avaliação da atividade biocida foi realizada através do método da contagem em placas, utilizando-se uma cepa de Escherichia coli ATCC11775 em concentrações de 103 a 107 células/mL. Todas as resinas impregnadas mostraram atividade bactericida significante devido à presença de iodo correlacionada às características da resina, tais como: grupos funcionais, tamanho e formato dos poros. Para efeito de comparação, foram realizados ensaios bactericidas com as resinas de partida para comprovação ou não da ação bactericida ser atribuída somente ao iodo

Caracterização e desenvolvimento de argilas para aplicação em nanocompósitos poliméricos

O Brasil é produtor de argilas e conta com grandes reservas deste recurso natural. Porém, grande parte da sua produção é comercializada seca e moída. O desenvolvimento de argilas para seu uso como reforço em nanocompósitos poliméricos constitui uma opção para os produtores desta matéria prima que teriam assim um produto com maior valor agregado. Este trabalho visa avaliar o potencial uso como nanocarga de duas argilas nacionais provenientes da Bacia de Taubaté, São Paulo, denominadas ALIGRA e SANTA FÉ. As frações de tamanho de partícula médio menor de 0,02 mm, obtidas por peneiramento á úmido da argila homogeneizada e seca, foram utilizadas no desenvolvimento do trabalho experimental. Os estudos de caracterização, envolvendo análise granulométrica, química, mineralógica, morfológica, térmica e textural, revelaram características muito semelhantes em ambas às argilas. Fração argila, maior de 70% em massa. Composição química conforme a definição química de uma argila e os teores de seus componentes mostram valores intermédios entre as apresentadas pelas bentonitas e argila caulinítica usadas com fins de comparação. Ressaltamse boas propriedades adsorventes. Área superficial específica BET ao redor de 120 m2/g, valor maior do que o apresentado por muitas bentonitas naturais (74,5 m2/g). Predominantemente mesoporosas, com poros, maiormente em forma de fenda, característicos da estrutura em camadas das argilas. Baixa capacidade de troca catiônica, 12 meq/100g. Difratogramas de raios-X revelaram a predominância do estratificado ilita/esmectita, caulinita e quartzo na argila ALIGRA, e de ilita, caulinita e quartzo na argila SANTA FÉ. Prosseguiu-se com a argila ALIGRA a preparação da argila organofílica. A argila organofílica foi obtida por troca catiônica com o sal quaternário de amônio: cloro cetril trimetil amônio, depois de homogeneizada em sódio com cloreto de sódio. Análises FTIR e TGA indicaram que houve inserção dos cátions orgânicos. Testes preliminares foram feitas, preparando misturas das argilas com matriz de polipropileno e usando como agente compatibilizante polipropileno enxertado com anidrido maleico. Resultados de ensaios de tração reportam algumas melhoras nas propriedades testadas com as composições preparadas com as argilas purificadas. Com as composições com argilas organofílicas somente foi melhorado o alongamento na rotura. Estudos ais aprofundados são recomendados.

River Erme Fisheries Survey 1965

This is the River Erme Fisheries Survey, 1965 by the Devon River Authority. The survey was carried out during April and May 1965, with the principal object being the determination of the abundance and distribution of salmonid fish in the River Erme in relation to the discharge from Stowford Paper Mills, Ivybridge. It contains a brief introduction of general aspects of the catchment, chemistry, pollution, biology and fisheries in the river, methodology that looks at the selected transects and techniques for sampling, results and recommendations. It contains tables with totals of all salmonid fish found at each section, size distribution of trout, surface area of section and population density.

Avaliação microtomográfica de canais mesiais de molares inferiores preparados com sistemas rotatórios e reciprocantes

O objetivo do presente trabalho foi avaliar, em microtomografia computadorizada (CT), o preparo de canais de molares inferiores com diferentes sistemas acionados a motor. Foram selecionadas 58 raízes mesiais patentes, de diâmetro anatômico correspondente a #10. Para a avaliação em TC, um anel de aço inoxidável foi confeccionado nos moldes do suporte para amostra do microtomógrafo, para que servisse de fôrma para a inclusão das raízes em resina Duralay, a fim de padronizar a posição do espécime no escaneamento inicial e final. Os canais foram preparados com os sistemas Reciproc R25 (n=16); WaveOne Primary File (n=16); Twisted File (n=14), e HyFlex (n=12). Após serem escaneados, foram reconstruídos tridimensionalmente e avaliados quantitativamente quanto à variação de volume (mm3), área de superfície (mm2) e structure model index (SMI). Foi, ainda, realizada a avaliação qualitativa das seções transversais por terço e por quadrante (MV, ML, DV, DL), sendo avaliado o toque de paredes. Os dados paramétricos foram analisados estatisticamente pelos testes ANOVA e t para amostras pareadas (α=5%). Não foi observada diferença estatística nos parâmetros quantitativos avaliados para Reciproc (142,77 76,75; 42,22 19,22; e 14,68 17,69, respectivamente); WaveOne (105,09 64,82; 29,54 19,21; 14,81 9,10, respectivamente); Twisted File (111,83 43,09; 33,31 18,40; 9,16 6,57, respectivamente), e HyFlex (151,74 149,37; 43,08 41,44; 10,80 8,52, respectivamente) (p=0,423). Dentro de cada grupo, foi observada diferença significante entre os resultados pré e pós-operatórios. O teste não paramétrico de Kruskal Wallis foi aplicado para a avaliação relativa ao toque de paredes. Foi observado que o sistema HyFlex apresentou a maior porcentagem de toques (82,3 13,1), seguido por Reciproc (81,3 16,9), Twisted File (78,3 14,4) e, por fim, WaveOne (76,9 21,7) (p>0,05). Em relação aos terços não foi observada diferença significativa (p=0,424). Os resultados da avaliação dos quadrantes intergrupo não demonstraram diferenças, porém indicaram tendência do preparo em direção à parede distal no terço cervical. Ao final, pôde-se concluir que os sistemas testados se equivalem quanto ao preparo de canais mesiais de molares inferiores; porém, nenhuma das técnicas foi capaz de tocar completamente em todas as paredes do canal radicular.

Carbon nanotube array: a new MIP platform.

Here we demonstrate that a free-standing carbon nanotube (CNT) array can be used as a large surface area and high porosity 3D platform for molecular imprinted polymer (MIP), especially for surface imprinting. The thickness of polymer grafted around each CNT can be fine-tuned to imprint different sizes of target molecules, and yet it can be thin enough to expose every imprint site to the target molecules in solution without sacrificing the capacity of binding sites. The performance of this new CNT-MIP architecture was first assessed with a caffeine-imprinted polypyrrole (PPy) coating on two types of CNT arrays: sparse and dense CNTs. Real-time pulsed amperometric detection was used to study the rebinding of the caffeine molecules onto these CNT-MIPPy sensors. The dense CNT-MIPPy sensor presented the highest sensitivity, about 15 times better when compared to the conventional thin film, whereas an improvement of 3.6 times was recorded on the sparse CNT. However, due to the small tube-to-tube spacing in the dense CNT array, electrode fouling was observed during the detection of concentrated caffeine in phosphate buffer solution. A new I-V characterization method using pulsed amperometry was introduced to investigate the electrical characterization of these new devices. The resistance value derived from the I-V plot provides insight into the electrical conductivity of the CNT transducer and also the effective surface area for caffeine imprinting.

The effect of intensive line fishing on the virgin biomass of a tropical deepwater snapper, the crimson jobfish (Pristipomoides filamentosus)

An intensive commercial hook-and-line fishing operation targeted the demersal fisheries resources at Saya de Malha Bank in the Southwest Indian Ocean. Fishing was conducted with 12 dories that were equipped with echo sounders and electric fishing reels and supported by a refrigerated mothership. Over a 13-day period in the 55–130 m depth range, a total of 74.3 metric tons (t) of fish were caught, of which the crimson jobfish (Pristipomoides filamentosus) represented 80%. Catch rates decreased with time and could not be attributed to changes in location, climatic conditions, fishing depth, fishing method, or bait type. The initial virgin biomass of P. filamentosus available to a line fishery at the North Western promontory of Saya de Malha Bank was estimated at 72.6 t through application of the Leslie model to daily catch and effort data. Biomass densities of 2364 kg/km2 and 1206 kg/km were obtained by applying the initial biomass estimates to the surface area and to the length of the dropoff that was fished. The potential sustainable yield prior to exploitation was estimated at 567 kg/km2 per year. The quantity of P. filamentosus caught by the mother-ship-dory fishing operation represented 82% of the initial biomass available to a hook-and-line fishery, equivalent to more that three times the estimated maximum sustainable yield. The results of the study are important to fisheries managers because they demonstrate that intensive line fishing operations have the potential to rapidly deplete demersal fisheries resources.

Multiple-proxy lacustrine record of moisture transport over western North America from 24,000 to 12,000 YBP, Lake Estancia, New Mexico [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Pluvial Lake Estancia in central New Mexico experienced large and rapid fluctuations in surface area and elevation during the build-up to and termination of the last glacial maximum (LGM). Due to continuous groundwater discharge, a minimum pool covering about 400 square kilometers was maintained in the central basin until about 12,000 years ago, ensuring a continuous depositional sequence even during low stands of the lake. ... The sensitive response to fluctuations in climate by several independent proxies at Estancia show that transport of Pacific moisture over western North America changed dramatically during the last Ice Age, perhaps comparable to the large and rapid changes in climate documented from high-latitude ice and North Atlantic marine sediments for the LCM and its transitions.

THEORETICAL ROAD DAMAGE DUE TO DYNAMIC TYRE FORCES OF HEAVY VEHICLES. PART 2: SIMULATED DAMAGE CAUSED BY A TANDEM-AXLE VEHICLE.

The literature relating to road surface failure and design is briefly reviewed and the conventional methods for assessing the road damaging effects of dynamic tire forces are examined. A new time domain technique for analyzing dynamic tire forces and four associated road damage criteria are presented. The force criteria are used to examine the road damaging characteristics of a simple tandem-axle vehicle model for a range of speed and road roughness conditions. It is concluded that for the proposed criteria, the theoretical service life of road surfaces that are prone to fatigue failure may be reduced significantly by the dynamic component of wheel forces. The damage done to approximately five per cent of the road surface area during the passage of a theoretical model vehicle at typical highway speeds may be increased by as much as four times.

Modeling of unsteady transitional boundary layers

In turbomachinery, a considerable proportion of the blade surface area can be covered by transitional boundary layers. This means that accurate prediction of the profile loss and boundary layer behavior in general depends on the accurate modeling of the transitional boundary layers, especially at low Reynolds numbers. This paper presents a model for determining the intermittency resulting from the unsteady transition caused by the passage of wakes over a blade surface. The model is founded on work by Emmons (1951) who showed that the intermittency could be calculated from a knowledge of the behavior of randomly formed turbulent spots. The model is used to calculate the development of the boundary layer on the rotor of a low Reynolds number single-stage turbine. The predictions are compared with experimental results obtained using surface-mounted hot-film anemometers and hot-wire traverses of the rotor midspan boundary layer at two different rotor-stator gaps. The validity and limitations of the model are discussed.

Report of the Frame Survey of Lake Albert conducted in May 2012

Lake Albert and Albert Nile are a major source of fisheries resources sustaining the riparian communities in Uganda and the Democratic Republic of Congo (DRC). Like all shared bodies of Uganda Lake Albert and Albert Nile fisheries are faced with immense exploitation pressure one time described as the tragedy of the commons. In Uganda, the lake is shared by five riparian districts namely: Buliisa, Bundibugyo, Hoima, Kibaale and Nebbi. The lake covers a total estimated surface area of 5,270 square kilometers with approximately 60% within Ugandan waters. It is located in the western part of the great rift-valley at an altitude of 618 m above Sea level. The central parts of the lake are characterized by steep escarpments whereas the northern and southern parts lie in a plain of the rift valley. The plains are gently sloping, resulting in shallow swampy inshore waters in many places. The major inflowing rivers are the Semliki and Kafu in the south, and the Victoria Nile at the northern tip. The lake has a diverse fish fauna with a gradient of multi-species fisheries in different parts of the lake. The overall objective of the Frame Survey was to provide information on the facilities and services at landing sites and the composition, magnitude and distribution of fishing effort to guide development and management of the fisheries resources of Lake Albert and Albert Nile. The specific objectives were to provide information on: a) The number of fish landing sites; b) The facilities available at the fish landing sites to service the sector including accessibility; c) The service providers especially fisheries staff at fish landing sites; d) The number of fishers; e) The number and types of fishing crafts and their mode of propulsion; f) The number, types and sizes of fishing gears used on the lake and their mode of operation.

The establishment of a commercial fishery for Haplochromis in the Uganda waters of Lake Victoria

Lake Victoria, straddling the Equator, is the second largest lake in the world, with a surface area of approximately 26,000 square miles (41,500 square kilometers) and a maximum depth of about 300 feet. Uganda possesses most of the north end of the lake which consists of a long, indented coastline and a chain of offshore islands on the edge of a 'continental shelf' separating relatively shallow sheltered inshore waters from the deeper open waters of the lake. At the present time the lake is harvested mainly by a native gill net fishery confined almost entirely to the shallow sheltered inshore waters. The annual production of all species from Uganda waters is in the region of 24,000 tons per annum, and Tilapia(Cichlidae)is commercially the most important genus. Haplochromis, a close relative of Tilapia, but generally much smaller, contributes only a small amount to this annual production; see Table 1, although they are probably the most abundant group of fish present in the lake. Through international aid programmes Uganda has been offered a canning plant and it is thought that Haplochromis is the most suitable type of fish to be utilized by such a plant. The Uganda Fisheries Department are conducting research into processing techniques and marketing and the East African Freshwater Fisheries Research Organization was asked to conduct a survey of the Haplochromis stocks of the lake with a view to estimating the ability or otherwise of these stocks to support a commercial canning industry.

Application of a laminar flamelet model to confined explosion hazards

The majority of computational studies of confined explosion hazards apply simple and inaccurate combustion models, requiring ad hoc corrections to obtain realistic flame shapes and often predicting an order of magnitude error in the overpressures. This work describes the application of a laminar flamelet model to a series of two-dimensional test cases. The model is computationally efficient applying an algebraic expression to calculate the flame surface area, an empirical correlation for the laminar flame speed and a novel unstructured, solution adaptive numerical grid system which allows important features of the solution to be resolved close to the flame. Accurate flame shapes are predicted, the correct burning rate is predicted near the walls, and an improvement in the predicted overpressures is obtained. However, in these fully turbulent calculations the overpressures are still too high and the flame arrival times too low, indicating the need for a model for the early laminar burning phase. Due to the computational expense, it is unrealistic to model a laminar flame in the complex geometries involved and therefore a pragmatic approach is employed which constrains the flame to propagate at the laminar flame speed. Transition to turbulent burning occurs at a specified turbulent Reynolds number. With the laminar phase model included, the predicted flame arrival times increase significantly, but are still too low. However, this has no significant effect on the overpressures, which are predicted accurately for a baffled channel test case where rapid transition occurs once the flame reaches the first pair of baffles. In a channel with obstacles on the centreline, transition is more gradual and the accuracy of the predicted overpressures is reduced. However, although the accuracy is still less than desirable in some cases, it is much better than the order of magnitude error previously expected.

National Agricultural Research Organisation. Fisheries Resources Research Institute Annual Report 2002/2003

One of the avenues through which the Government objective of poverty eradication in Uganda can be achieved is Fisheries development and management. Up to 20% of Uganda’s surface area is covered by aquatic systems i.e. lakes, rivers, streams and swamps and to a large extent, all these are interconnected. The large lakes: Victoria, Albert, Kyoga, George and Edward are sites of the more important commercial fisheries, but even the smaller water bodies, rivers (e.g. the Rivers Nile and Kagera) and the surrounding swamps provide sources of livelihood to rural areas. Fish is an important source of high quality food, employment revenue and is currently the second most important export commodity next to coffee generating approximately US $ 80 million annually. Fish exports to regional markets are worth at least US $ 20 million annually. Fish flesh is rich in proteins, which are superior to those of beef and poultry. Fish flesh contains an anticholesterol which assists in reducing heart diseases. Some fishes are of medicinal value e.g. haplochromines (Nkejje) are used to treat measles. Most of the fish in Uganda is got from lakes Victoria, Kyoga, Albert and Albert Nile, Edward and George production systems as well as from the 160 minor lakes and rivers and the associated wetland systems. Capture fisheries based in these systems contribute up to 99% of the fish production in Uganda but aquaculture is also picking up. The fishing industry employs up to one million Ugandans

National Agricultural Research Organisation. Fisheries Resources Research Institute Annual Report 2003/2004

About 18% of Uganda’s surface area is covered with water from which 300,000 metric tonnes of fish are produced. Fish are currently the second most important export commodity generating approximately US$100 million. Fish provides 50% of protein diet for the 20 million people translating into per capita consumption of 12 kg. Close to the production system, this figure rises to 50 – 100 kg. It is estimated that fishery-related activities employ at least one million people countrywide (i.e. 5% of the population). Fish is an important source of high quality food, employment, and revenue and it is currently the second most important export commodity next to coffee generating approximately US $ 80 million annually. Fish exports to regional markets are worth at least US $ 20 million annually. Fish flesh is rich in proteins, which are superior to those of beef and poultry. Fish flesh contains an anticholesterol which assists in reducing heart diseases. Some fishes are of medicinal value e.g. haplochromines (Nkejje) are used to treat measles. Most of the fish in Uganda is got from lakes Victoria, Kyoga, Albert and Albert Nile, Edward and George production systems as well as from the 160 minor lakes and rivers and the associated wetland systems. Capture fisheries based in these systems contribute up to 99% of the fish production in Uganda but aquaculture is also picking up. The fishing industry employs up to one million Ugandans.

National Agricultural Research Organisation. Fisheries Resources Research Institute Annual Report 2004/2005

About 18% of Uganda’s surface area is covered with water from which about 300,000 metric tonnes of fish are produced. Fish are currently the second most important export commodity generating approximately US$100 million annually. Fish provides 50% of protein diet for the 20 million people translating into per capita consumption of 12 kg. Close to the production system, this figure rises to 50 – 100 kg. It is estimated that fishery-related activities employ at least one million people countrywide (i.e. 5% of the population). Fish exports to regional markets are worth at least US $ 20 million annually. Fish flesh contains an anticholesterol which assists in reducing heart diseases. Some fishes are of medicinal value e.g. haplochromines (Nkejje) are used to treat measles. Most of the fish in Uganda is got from lakes Victoria, Kyoga, Albert and Albert Nile, Edward and George production systems as well as from the 160 minor lakes and rivers and the associated wetland systems. Capture fisheries based in these systems contribute up to 99% of the fish production in Uganda but aquaculture is also picking up. The fishing industry employs up to one million Ugandans