Micro-raman spectroscopic characterization of a CR-39 detector

Characterization by micro-Raman spectroscopy of polymeric materials used as nuclear track detectors reveals physico-chemical and morphological information on the material's molecular structure. In this work, the nuclear track detector poly(allyl diglycol carbonate), or Columbia Resin 39 (CR-39), was characterized according to the fluence of alpha particles produced by a 226Ra source and chemical etching time. Therefore, damage of the CR-39 chemical structure due to the alpha-particle interaction with the detector was analyzed at the molecular level. It was observed that the ionization and molecular excitation of the CR-39 after the irradiation process entail cleavage of chemical bonds and formation of latent track. In addition, after the chemical etching, there is also loss of polymer structure, leading to the decrease of the group density C-O-C (∼888 cm-1), CH=CH (∼960 cm -1), C-O (∼1110 cm-1), C-O-C (∼1240 cm -1), C-O (∼1290 cm-1), C-O (∼1741 cm -1), -CH2- (∼2910 cm-1), and the main band -CH2- (∼2950 cm-1). The analyses performed after irradiation and chemical etching led to a better understanding of the CR-39 molecular structure and better comprehension of the process of the formation of the track, which is related to chemical etching kinetics. Copyright © 2013 Society for Applied Spectroscopy.

Inversor Buck-Boost integrado para aplicações com micro-geradores eólicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seleção de micro-organismos fermentadores de xilose em etanol a partir de diferentes variedades da casca de uvas (Vitis spp)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese de nanoestruturas de ZnO por redução carbotérmica e hidrotermal, assistido por micro-ondas: caracterização como sensor

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Os custos socioeconômicos e ambientais dos impactos da urbanização de Imperatriz nos mananciais urbanos: um estudo de caso na micro-bacia do Riacho Bacuri

A análise tem como linha de pesquisa urbanização, cidades da Amazônia e meio ambiente. Foi realizado um levantamento histórico do potencial hidrográfico da região, onde está localizada atualmente a cidade de Imperatriz-MA, identificando geograficamente todas as nascentes, mananciais e afluentes do rio Tocantins. De posse desses dados e informações, foi possível traçar o perfil quantitativo e qualitativo dos riachos que cortam o perímetro urbano do município. O estudo faz uma abordagem também dos custos dos impactos provocados pelo processo da urbanização do município de Imperatriz-MA, contra a micro-bacia do riacho Bacuri. Análise do fato está focada na problemática da poluição do riacho, e as manifestações negativas adventícia do processo de degradação. Faz-se um levantamento sistematizado intertemporal dos elementos da fauna e da flora aquática que existiam e os que, ainda remanesce na localidade próxima a esse manancial, expondo os impactos socioeconômicos e ambientais, ocorrido ao longo dos anos, contra o homem e a natureza.

Polihidroxialcanoatos (PHAs): bioprospecção de micro-organismos e produção a partir de glicerol

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Micro-fungos de interesse para o setor de petróleo, gás e biocombustíveis

Oil is a hydrocarbon mixture of various sizes, including saturated and aromatic compounds. Natural gas is a mixture of gaseous hydrocarbons and its main component is methane. In our society, the great demand for these fuels requires fast extraction, transportation and refining, increasing the number of accidents that compromise the environment. Oil is a finite resource and it is necessary to reduce the problems related to the question concerning environmental pollution which has encouraged the search for alternative fuel sources in our country. So today we have two major biofuels: ethanol and biodiesel. Concurrently, many studies have been done directed toward the isolation of microorganisms capable of degrading petrochemical industrial wastes, most of them using as a source of isolation soil and water collected in a contaminated environment. Isolation from alternative substrates has emerged as a new strategy that has provided satisfactory results. In this work, we present the leaf-cutter ants of the Attini tribe as a source for the isolation of micro-fungi with the potential for hydrocarbon degradation. These insects have a social way of life and a highly specialized system of intra and interspecific communication, which is based on the recognition of individuals through volatile chemical compounds, the majority hydrocarbons, stored in their exoskeleton. The micro-environment exoskeleton of Attini ants (genus Atta) used in this work proved to be a rich source of microbial biodiversity, as other studies have found. The flotation isolation technique applied here allowed the achievement of 214 micro-fungi, 118 representatives of the dematiaceous fungi group and 96 hyaline filamentous fungi. They were submitted to toluene degradation tests and at least one strain of each genus presented good results, namely Teratosphaeria, Exophiala, Cladosporium, Penicillium, Aspergillus... (Complete abstract click electronic access below)

Citrus greening disease investigation using micro synchrotron radiation X-ray fluorescence in association with soft independent modelling of class analogy (SIMCA)

This study describes the use of micro synchrotron radiation X-ray fluorescence (µSR-XRF) to investigate citrus greening disease in sweet orange (Citrus sinensis) plants. An experiment using healthy plants as control and plants of the same variety infected with Candidatus Liberibacter asiaticus (CLas) was performed to verify variations of the mineral composition of citrus leaves. A µSR-XRF system using the D09B X-ray fluorescence beam line at the Brazilian Synchrotron Light Source (LNLS, Campinas, São Paulo State) was employed for this purpose. The data were analyzed using a chemometric tool called soft independent modelling of class analogy (SIMCA). The promising results from SIMCA models reinforce the evidence that plants infected by citrus greening (both asymptomatic and symptomatic) undergo alterations in their micro- and macronutrient compositions.

Application of Micro-Raman Spectroscopy to the Study of Yttria-Stabilized Tetragonal Zirconia Polycrystal (Y-TZP) Phase Transformation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Energetic exploitation from a hybrid PV-wind power micro-generation rural electrification

Hybrid system micro-generation integration of PV-wind power is presented by a form of energy in which problems resulting from variability in the intensity of wind and solar intensity are possible mitigation either by complementation between one source to another or the largest stability configured by the generate the system. Based on this context, this work aims to assessing the performance of a hybrid system PV-wind power energy small of a rural property for their electrification. The study has been developed at the Rural Laboratory Powering from Engineering Department of UNESP. In order to present this research, a hybrid system has been installed PV-wind power, composed of one 400Wp windmill and a 300 Wp PV-system. The results obtained allowed us to evaluate the solar and wind energy supplied ranked among 285 and 360 kWh electric power generated by the PV-wind power hybrid system stood between 25,5 and 31 kWh. At is to say achieving yield of approximately than 10% during one year observation period, i.e., it was concluded that the performance of the hybrid system depended essentially the energy received and generated by the PV-system and that there was complementation between generating wind power and PV-systems with regard to time of day and the annual seasons by confirming the technical feasibility of this kind system of micro-generation in small rural properties.

Biossorção & biodegradação de azo corante: desenvolvimento de processos utilizando resíduos como fonte de microorganismos = Azo dye biosorption & biodegradation : process development with residues as source of microorganisms

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Acúmulo de cádmio, crômio e níquel e isolamento de micro-organismos potenciais para biorremediação em área agrícola

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization of inclusions and their distribution in natural and artificial samples by synchrotron cryo-micro-tomography (SCXRT)

Zur geometrischen Vermessung und Beschreibung von Einschlüssen in natürlichen sowie im Labor geschaffenen Eispartikeln wurde ein neuartiger Versuchaufbau an der Tomographie-Endstation der Material Science Beam Line an der Swiss Light Source (SLS, Paul Scherrer Institut, Villigen, Schweiz) entwickelt. Dieser besteht aus einer Plexiglas-Tasse und einem doppelwandigen Kaptonfolien-Käfig, der wiederum auf die Düse eines CryojetXL (Oxford Instruments) montiert wurde. Abgesehen von dem hohen Maß an Flexibilit¨at bez¨uglich der Installation erlaubt es dieser Aufbau, die Temperatur des Experiments mit einer Genauigkeit von ± 1 K über einen Bereich von 271 K bis 220 K zu regeln. In den hier beschriebenen Experimenten wurde eine räumliche Auflösung von 1.4 µm erzielt.

Seismic sequences analysis for estimation of earthquake source parameters: corner frequency, stress drop, and seismic moment observations

The present study has been carried out with the following objectives: i) To investigate the attributes of source parameters of local and regional earthquakes; ii) To estimate, as accurately as possible, M0, fc, Δσ and their standard errors to infer their relationship with source size; iii) To quantify high-frequency earthquake ground motion and to study the source scaling. This work is based on observational data of micro, small and moderate -earthquakes for three selected seismic sequences, namely Parkfield (CA, USA), Maule (Chile) and Ferrara (Italy). For the Parkfield seismic sequence (CA), a data set of 757 (42 clusters) repeating micro-earthquakes (0 ≤ MW ≤ 2), collected using borehole High Resolution Seismic Network (HRSN), have been analyzed and interpreted. We used the coda methodology to compute spectral ratios to obtain accurate values of fc , Δσ, and M0 for three target clusters (San Francisco, Los Angeles, and Hawaii) of our data. We also performed a general regression on peak ground velocities to obtain reliable seismic spectra of all earthquakes. For the Maule seismic sequence, a data set of 172 aftershocks of the 2010 MW 8.8 earthquake (3.7 ≤ MW ≤ 6.2), recorded by more than 100 temporary broadband stations, have been analyzed and interpreted to quantify high-frequency earthquake ground motion in this subduction zone. We completely calibrated the excitation and attenuation of the ground motion in Central Chile. For the Ferrara sequence, we calculated moment tensor solutions for 20 events from MW 5.63 (the largest main event occurred on May 20 2012), down to MW 3.2 by a 1-D velocity model for the crust beneath the Pianura Padana, using all the geophysical and geological information available for the area. The PADANIA model allowed a numerical study on the characteristics of the ground motion in the thick sediments of the flood plain.

AN ASSESSMENT OF BALLAST SOURCE'S QUALITY AND LOCATIONS WITH RESPECT TO MDOT'S UPGRADE OF THE WOLVERINE RAILROAD LINE FOR HIGH SPEED RAIL USEAGE

The Michigan Department of Transportation is evaluating upgrading their portion of the Wolverine Line between Chicago and Detroit to accommodate high speed rail. This will entail upgrading the track to allow trains to run at speeds in excess of 110 miles per hour (mph). An important component of this upgrade will be to assess the requirement for ballast material for high speed rail. In the event that the existing ballast materials do not meet specifications for higher speed train, additional ballast will be required. The purpose of this study, therefore, is to investigate the current MDOT railroad ballast quality specifications and compare them to both the national and international specifications for use on high speed rail lines. The study found that while MDOT has quality specifications for railroad ballast it does not have any for high speed rail. In addition, the American Railway Engineering and Maintenance-of-Way Association (AREMA), while also having specifications for railroad ballast, does not have specific specifications for high speed rail lines. The AREMA aggregate specifications for ballast include the following tests: (1) LA Abrasion, (2) Percent Moisture Absorption, (3) Flat and Elongated Particles, (4) Sulfate Soundness test. Internationally, some countries do require a highly standard for high speed rail such as the Los Angeles (LA) Abrasion test, which is uses a higher standard performance and the Micro Duval test, which is used to determine the maximum speed that a high speed can operate at. Since there are no existing MDOT ballast specification for high speed rail, it is assumed that aggregate ballast specifications for the Wolverine Line will use the higher international specifications. The Wolverine line, however, is located in southern Michigan is a region of sedimentary rocks which generally do not meet the existing MDOT ballast specifications. The investigation found that there were only 12 quarries in the Michigan that meet the MDOT specification. Of these 12 quarries, six were igneous or metamorphic rock quarries, while six were carbonate quarries. Of the six carbonate quarries four were locate in the Lower Peninsula and two in the Upper Peninsula. Two of the carbonate quarries were located in near proximity to the Wolverine Line, while the remaining quarries were at a significant haulage distance. In either case, the cost of haulage becomes an important consideration. In this regard, four of the quarries were located with lake terminals allowing water transportation to down state ports. The Upper Peninsula also has a significant amount of metal based mining in both igneous and metamorphic rock that generate significant amount of waste rock that could be used as a ballast material. The main drawback, however, is the distance to the Wolverine rail line. One potential source is the Cliffs Natural Resources that operates two large surface mines in the Marquette area with rail and water transportation to both Lake Superior and Lake Michigan. Both mines mine rock with a very high compressive strength far in excess of most ballast materials used in the United States and would make an excellent ballast materials. Discussions with Cliffs, however, indicated that due to environmental concerns that they would most likely not be interested in producing a ballast material. In the United States carbonate aggregates, while used for ballast, many times don't meet the ballast specifications in addition to the problem of particle degradation that can lead to fouling and cementation issues. Thus, many carbonate aggregate quarries in close proximity to railroads are not used. Since Michigan has a significant amount of carbonate quarries, the research also investigated using the dynamic properties of aggregate as a possible additional test for aggregate ballast quality. The dynamic strength of a material can be assessed using a split Hopkinson Pressure Bar (SHPB). The SHPB has been traditionally used to assess the dynamic properties of metal but over the past 20 years it is now being used to assess the dynamic properties of brittle materials such as ceramics and rock. In addition, the wear properties of metals have been related to their dynamic properties. Wear or breakdown of railroad ballast materials is one of the main problems with ballast material due to the dynamic loading generated by trains and which will be significantly higher for high speed rails. Previous research has indicated that the Port Inland quarry along Lake Michigan in the Southern Upper Peninsula has significant dynamic properties that might make it potentially useable as an aggregate for high speed rail. The dynamic strength testing conducted in this research indicate that the Port Inland limestone in fact has a dynamic strength close to igneous rocks and much higher than other carbonate rocks in the Great Lakes region. It is recommended that further research be conducted to investigate the Port Inland limestone as a high speed ballast material.