1000 resultados para Three Forks Shale
Resumo:
In the present diploma work optical inspection methods were used to investigate surface roughness of paper samples. A special measurement setup, which includes three laser light sources of three different wavelengths, photodetector and goniometer, was used to measure the reflected laser light properties. The intensity of the light reflected in specular direction was measured versus the laser incidence angle for reference metal sample. The value of roughness was estimated and compared to initially known value of metal sample roughness. Thus, the measurement equipment and method were validated. Then the reflected intensity was measured versus reflection angle at constant incidence angle for the same metal sample and paper samples under investigation. The final values of the surface roughness were obtained from the analysis of the reflected intensity dependence. The results are in good correlation with other research groups.
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The main purpose of this thesis is to investigate winner-loser performance when financial markets are facing crisis. This is examined through the idea that does the prior loser portfolios outperform the prior winner portfolios during the three major crises: The depression of the 1990s, the IT-Bubble and the Subprime -crisis. Firstly, the winner and loser portfolios superiority is counted by using the cumulative excess returns from the examination period. The portfolios were formed by counting the excess returns and locating them in to the order of superiority. The excess returns are counted by using one year pre-data before the actual examination period. The results of this part did not support the results of De Bondt & Thaler’s (1985) paper. Secondly, it is investigated how the Finnish and the US macroeconomic factors are seen to be affecting the stock market valuation in Finnish Stock Markets during economic crises. This is done to explain better the changes in the successes of the winner-loser performance. The crises included different amount of selected macro factors. Two latest crises involved as well few selected US macro factors. Exclusively the IT-Bubble -crisis had the most statistically significant results with the US factors. Two other crises did not receive statistically significant results. An extra research was produced to study do the US macro factors impact more significantly on Finnish stock exchange after lags. The selected lags were three, six, nine and twelve months. Three and six month lagged US macro factors during the IT-Bubble -crisis improved the results. The extra research did not improve the results of the Subprime -crisis.
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Understanding how marine predators interact is a scientific challenge. In marine ecosystems, segregation in feeding habits has been largely described as a common mechanism to allow the coexistence of several competing marine predators. However, little is known about the feeding ecology of most species of chondrichthyans, which play a pivotal role in the structure of marine food webs worldwide. In this study, we examined the trophic ecology of 3 relatively abundant chondrichthyans coexisting in the Mediterranean Sea: the blackmouth catshark Galeus melastomus , the velvet belly lanternshark Etmopterus spinax and the rabbit fish Chimaera monstrosa. To examine their trophic ecology and interspecific differences in food habits, we combined the analysis of stomach content and stable isotopes. Our results highlighted a trophic segregation between C. monstrosa and the other 2 species. G. melastomus showed a diet composed mainly of cephalopods, while E. spinax preyed mainly on shrimps and C. monstrosa on crabs. Interspecific differences in the trophic niche were likely due to different feeding capabilities and body size. Each species showed different isotopic niche space and trophic level. Specifically, C. monstrosa showed a higher trophic level than E. spinax and G. melastomus. The high trophic levels of the 3 species highlighted their important role as predators in the marine food web. Our results illustrate the utility of using complementary approaches that provide information about the feeding behaviour at short (stomach content) and long-term scales (stable isotopes), which could allow more efficient monitoring of marine food-web changes in the study area.
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We compute families of symmetric periodic horseshoe orbits in the restricted three-body problem. Both the planar and three-dimensional cases are considered and several families are found.We describe how these families are organized as well as the behavior along and among the families of parameters such as the Jacobi constant or the eccentricity. We also determine the stability properties of individual orbits along the families. Interestingly, we find stable horseshoe-shaped orbit up to the quite high inclination of 17◦
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From the boiler design point of view, it is imperative to know and understand the operation of the boiler. Since comprehensive measurement of a large furnace is impossible, the furnace can be modeled in order to study its behavior and phenomena. This requires the used model to be validated to correspond with the physical furnace behavior. In this thesis, a three dimensional furnace model is validated to match a bituminous coal utilizing, supercritical once-through circulating fluidized bed combustor based on measurement data. The validated model is used for analyzing the furnace heat transfer. Other heat transfer analysis methods are energy balance method based on tube surface temperature measurements and a method based on measured temperature difference between the tube crest and the fin. The latter method was developed in the thesis using Fluent-software. In the theory part, literature is reviewed and the fundamental aspects of circulating fluidized bed are discussed. These aspects are solid particle behavior in fluidization known as hydrodynamics, behavior of fuel and combustion and heat transfer. Fundamental aspects of modeling are also presented.
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Human papillomavirus (HPV) infections in mothers are important to consider since pregnancy may affect the outcome of the infection and the mother may transmit HPV to the child. This thesis is part of the 3-year Finnish Family HPV Study on HPV infection dynamics within 329 families. The presence of maternal HPV antibodies and HPV DNA in placenta, umbilical cord blood and breast milk was examined. In addition, genital and oral HR-HPV carriage was studied among mothers with one or two pregnancies. At enrollment, seropositivity to HPV 6, 11, 16, 18 and 45 was recorded in 53 %, 21 %, 35 %, 21 % and 9 % of the mothers, respectively. Age at sexual debut, number of sexual partners, a history of genital warts and antibodies to LR/HR-HPV predicted HR/LR-HPV-seropositivity. During follow-up 27 %, 14 %, 17 %, 17 % and 7 % of the mothers seroconverted to the tested HPV-types, respectively. Decay of HPV-antibodies was rare. The mother’s new pregnancy was of minor impact in the outcome of oral and cervical HR-HPV infections. HPV-DNA was present in 4.2 % and 3.5 % of the placentas and umbilical cord blood samples, and in 4.5 % and 19.7 % of the breast milk samples collected at day 3 and month 2 postpartum, respectively. HPV-positivity in placenta/cord blood was related to a history of abnormal pap-smears or genital warts, and raised the risk of the neonate being HPV-positive at birth. The mode of delivery did not predict the HPVstatus of neonate, placenta, or cord blood. HPV DNA in breast milk was associated with oral HPV status of the father, but not with HPV status of the neonate. The results indicate that exposure to HPV is common and that part of the exposure might take place already early in life. Contrary to the common claim, pregnancy is not a risk factor for HPV.
Multisystem Developmental Disorder in Children from 2 to 6 Years Old : A Three Years Follow-Up Study
Resumo:
This research studied children who had been diagnosed with Multisystem Developmental Disorder (MSDD) (NC, 2002) under the Diagnostic Classifications of Mental Health and Developmental Disorders of Infancy and Early Childhood (DC: 0 - 3). They all showed, to a varying degree, difficulties in relating to others, play, affective interaction and severe delay in developing communication skills. Some studies have observed continuity in the diagnosis of autism during the first years of life. The objective of this study is to analyse the development of infants with MSDD whose diagnosis of autism was not confirmed. We also attempted to verify any possible psychomotor developmental differences based on, or related to, the severity and typology (B and C) of the MSDD. To enable us to do this we carried out a 3-year follow-up during which we assessed the infants (n = 15) and their parents. They are 2 - 4 years old. Results showed that type B children did present a greater impairment of psychomotor development in assessment tests. However, we did not observe any correlation between the degree of severity of the initial symptoms and later diagnoses. Conclusion: although our sample is small, we can conclude that there isn’t a clear evolution in the diagnosis, but we have found significant differences in the symptomatology between the type B and C
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Phytochemical investigations on three Brazilian Lauraceae species from the Cerrado region of São Paulo State, Ocotea corymbosa (Meins) Mez., O. elegans Mez. and Persea pyrifolia Nees & Mart. ex Nees resulted in the isolation of flavonoids, an ester of the 4-O-E-caffeoylquinic acid, an aromatic sesquiterpene besides furofuran lignans. This is the first chemical study on the leaves of Ocotea elegans and O. corymbosa as well as the first report of non-volatile compounds from Persea pyrifolia.
Resumo:
An analytical procedure to quantify 3-benzophenone, octylmethoxycinnamate and octylsalicylate was validated and employed to assess these ultraviolet filters in sunscreen formulations and from skin penetration studies. The effect of the vehicle on the skin retention of these filters was investigated. HPLC and extraction procedure were found to be reliable when obtaining data for the sunscreen formulations and for evaluation skin penetration. The results demonstrated that a cream gel generated higher epidermal concentrations of these filters than a lotion or cream-based formulation. Additionally, when comparing the skin retentions of each filter using the same formulation, 3-benzophenone showed the highest skin retention.
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A method using Liquid Phase Microextraction for simultaneous detection of citalopram (CIT), paroxetine (PAR) and fluoxetine (FLU), using venlafaxine as internal standard, in plasma by high performance liquid chromatography with fluorescence detection was developed. The linearity was evaluated between 5.0 and 500 ng mL-1 (r > 0.99) and the limit of quantification was 2.0, 3.0 and 5.0 ng mL-1 for CIT, PAR and FLU, respectively. Therefore, it can be applied to therapeutic drug monitoring, pharmacokinetics or bioavailability studies and its advantages are that it necessary relatively inexpensive equipment and sample preparation techniques.
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Selective papers of the workshop on "Development of models and forest soil surveys for monitoring of soil carbon", Koli, Finland, April 5-9 2006.
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The Annonaceae family is distributed throughout Neotropical regions of the world. In Brazil, it covers nearly all natural formations particularly Annona, Xylopia and Polyalthia and is characterized chemically by the production of sources of terpenoids (mainly diterpenes), alkaloids, steroids, polyphenols and, flavonoids. Studies from 13C NMR data of diterpenes related with their botanical occurrence were used to generate self-organizing maps (SOM). Results corroborate those in the literature obtained from morphological and molecular data for three genera and the model can be used to project other diterpenes. Therefore, the model produced can predict which genera are likely to contain a compound.
Resumo:
Coal, natural gas and petroleum-based liquid fuels are still the most widely used energy sources in modern society. The current scenario contrasts with the foreseen shortage of petroleum that was spread out in the beginning of the XXI century, when the concept of "energy security" emerged as an urgent agenda to ensure a good balance between energy supply and demand. Much beyond protecting refineries and oil ducts from terrorist attacks, these issues soon developed to a portfolio of measures related to process sustainability, involving at least three fundamental dimensions: (a) the need for technological breakthroughs to improve energy production worldwide; (b) the improvement of energy efficiency in all sectors of modern society; and (c) the increase of the social perception that education is a key-word towards a better use of our energy resources. Together with these technological, economic or social issues, "energy security" is also strongly influenced by environmental issues involving greenhouse gas emissions, loss of biodiversity in environmentally sensitive areas, pollution and poor solid waste management. For these and other reasons, the implementation of more sustainable practices in our currently available industrial facilities and the search for alternative energy sources that could partly replace the fossil fuels became a major priority throughout the world. Regarding fossil fuels, the main technological bottlenecks are related to the exploitation of less accessible petroleum resources such as those in the pre-salt layer, ranging from the proper characterization of these deep-water oil reservoirs, the development of lighter and more efficient equipment for both exploration and exploitation, the optimization of the drilling techniques, the achievement of further improvements in production yields and the establishment of specialized training programs for the technical staff. The production of natural gas from shale is also emerging in several countries but its production in large scale has several problems ranging from the unavoidable environmental impact of shale mining as well as to the bad consequences of its large scale exploitation in the past. The large scale use of coal has similar environmental problems, which are aggravated by difficulties in its proper characterization. Also, the mitigation of harmful gases and particulate matter that are released as a result of combustion is still depending on the development of new gas cleaning technologies including more efficient catalysts to improve its emission profile. On the other hand, biofuels are still struggling to fulfill their role in reducing our high dependence on fossil fuels. Fatty acid alkyl esters (biodiesel) from vegetable oils and ethanol from cane sucrose and corn starch are mature technologies whose market share is partially limited by the availability of their raw materials. For this reason, there has been a great effort to develop "second-generation" technologies to produce methanol, ethanol, butanol, biodiesel, biogas (methane), bio-oils, syngas and synthetic fuels from lower grade renewable feedstocks such as lignocellulosic materials whose consumption would not interfere with the rather sensitive issues of food security. Advanced fermentation processes are envisaged as "third generation" technologies and these are primarily linked to the use of algae feedstocks as well as other organisms that could produce biofuels or simply provide microbial biomass for the processes listed above. Due to the complexity and cost of their production chain, "third generation" technologies usually aim at high value added biofuels such as biojet fuel, biohydrogen and hydrocarbons with a fuel performance similar to diesel or gasoline, situations in which the use of genetically modified organisms is usually required. In general, the main challenges in this field could be summarized as follows: (a) the need for prospecting alternative sources of biomass that are not linked to the food chain; (b) the intensive use of green chemistry principles in our current industrial activities; (c) the development of mature technologies for the production of second and third generation biofuels; (d) the development of safe bioprocesses that are based on environmentally benign microorganisms; (e) the scale-up of potential technologies to a suitable demonstration scale; and (f) the full understanding of the technological and environmental implications of the food vs. fuel debate. On the basis of these, the main objective of this article is to stimulate the discussion and help the decision making regarding "energy security" issues and their challenges for modern society, in such a way to encourage the participation of the Brazilian Chemistry community in the design of a road map for a safer, sustainable and prosper future for our nation.
Resumo:
An effective method for the rapid separation and purification of three stilbenes from the radix of Polygonum cillinerve (Nakai) Ohwl by macroporous resin column chromatography combined with high-speed counter-current chromatography (HSCCC) was successfully established. In the present study, a two-phase solvent system composed of chloroform-n-butanol-methanol-water (4:1:4:2, v/v/v/v) was used for HSCCC separation. A one-step separation in 4 h from 150 mg of crude extract produced 26.3 mg of trans-resveratrol-3-O-glucoside, 42.0 mg of pieceid-2"-O-gallate, and 17.9 mg of trans-resveratrol with purities of 99.1%, 97.8%, and 99.4%, respectively, as determined by high-performance liquid chromatography (HPLC). The chemical structures of these compounds were identified by nuclear magnetic resonance (NMR) spectroscopy.