409 research outputs found

    Recovery of Alumina From Coal Fly Ash By High Temperature Chlorination

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    The recovery of metals from low value sources will help reduce our national demand for foreign resources. The ash from bituminous type coals contains about 20 percent aluminum oxide and 20 percent iron oxides by weight. Recovery of these metals would provide an alternate source to the ores now used. The iron and aluminum materials in fly ash are recoverable by high temperature chlorination. Passing dry chlorine gas through a bed of nonmagnetic fly ash maintained at 850 to 900 degrees C. chlorinates the iron and aluminum constituents forming volatile compounds which are carried from the bed by the exit gas stream. In exploratory runs, 55 percent of the aluminum has been recovered as aluminum chloride in a nearly silica-free state

    The Magnetic Fraction of Coal Fly Ash: Its Separation, Properties, and Utilization

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    A laboratory-size electromagnetic device has been built to separate the high-iron magnetic fraction from coal fly ash. Fly ash, the fine particulate matter produced when pulverized coal is burned, contains an average of 18 wt. percent iron expressed as Fe2O3 found in a distinctive fraction of finely divided, dense, largely spheroidal particles of high magnetic susceptibility. Seventy to eighty percent of the iron in bituminous coal fly ash is found in this fraction which represents about 20 weight percent or 10 volume percent of the fly ash. In this work the iron-rich fraction has been characterized as to particle size, composition, and density. It appears to have a market potential as a material for preparation of high-density media used in coal washing and other mineral dressing processes. Dense-media material, which costs about $100 per metric ton, is being utilized in increasingly large quantities as the demand for washed coal expands. The magnetic fraction also appears to have potential as a source of iron. If further processing can reduce the silica level found in the fraction as it is separated from the ash, pellets with a composition similar to taconite can be prepared for use as blast furnace feed. Separation and use of this fraction of the coal ash could be profitable for utility companies and could be the beginning of the utilization of the large amount of ash which now constitutes a waste disposal problem

    Measurement of turbulent diffusion at short observation times using spin-echo NMR

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    Functional outcomes of patients undergoing anterolateral versus anteromedial approaches of the ankle for pilon fractures

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    Pilon fractures of the distal tibia remain a treatment challenge to orthopedists. Careful preoperative planning is crucial to achieving desirable clinical outcomes, but currently the literature does not reach a consensus on which surgical approach is optimal. This study examines functional outcomes of two of the most common surgical approaches for pilon fractures, the traditional anteromedial approach and the more recently described anterolateral approach. The anterolateral approach is thought to produce better outcomes because of the greater amount of visualization into the articular surface and greater soft tissue coverage for the implant

    The Role of Pathological Aging in Cardiac and Pulmonary Fibrosis

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    Aging promotes a range of degenerative pathologies characterized by progressive losses of tissue and/or cellular function. Fibrosis is the hardening, overgrowth and scarring of various tissues characterized by the accumulation of extracellular matrix components. Aging is an important predisposing factor common for fibrotic heart and respiratory disease. Age-related processes such as senescence, inflammaging, autophagy and mitochondrial dysfunction are interconnected biological processes that diminish the regenerative capacity of the aged heart and lung and have been shown to play a crucial role in cardiac fibrosis and idiopathic pulmonary fibrosis. This review focuses on these four processes of aging in relation to their role in fibrosis. It has long been established that the heart and lung are linked both functionally and anatomically when it comes to health and disease, with an ever-expanding aging population, the incidence of fibrotic disease and therefore the number of fibrosis-related deaths will continue to rise. There are currently no feasible therapies to treat the effects of chronic fibrosis therefore highlighting the importance of exploring the processes of aging and its role in inducing and exacerbating fibrosis of each organ. The focus of this review may help to highlight potential avenues of therapeutic exploration</p

    Household-level predictors of the presence of servants in Northern Orkney, Scotland, 1851–1901

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    Servants were an important part of the northwestern European household economy in the preindustrial past. This study examines household-level characteristics that are predictive of the presence of rural servants using data from Orkney, Scotland. The number of servants present in a household is related to household composition, landholding size, and the marital status of the household head. In addition, the sex of the particular servant hired reveals that the labor of male and female servants is not fungible. The sex of the servant hired is related to the ratio of male and female household members of working age, the occupation of the head, household composition, and the size of the household\u27s landholding

    Paternal obesity is associated with IGF2 hypomethylation in newborns: results from a Newborn Epigenetics Study (NEST) cohort

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    Data from epidemiological and animal model studies suggest that nutrition during pregnancy may affect the health status of subsequent generations. These transgenerational effects are now being explained by disruptions at the level of the epigenetic machinery. Besides in vitro environmental exposures, the possible impact on the reprogramming of methylation profiles at imprinted genes at a much earlier time point, such as during spermatogenesis or oogenesis, has not previously been considered. In this study, our aim was to determine associations between preconceptional obesity and DNA methylation profiles in the offspring, particularly at the differentially methylated regions (DMRs) of the imprinted Insulin-like Growth Factor 2 (IGF2) gene

    Common genetic variants, acting additively, are a major source of risk for autism

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    Abstract Background Autism spectrum disorders (ASD) are early onset neurodevelopmental syndromes typified by impairments in reciprocal social interaction and communication, accompanied by restricted and repetitive behaviors. While rare and especially de novo genetic variation are known to affect liability, whether common genetic polymorphism plays a substantial role is an open question and the relative contribution of genes and environment is contentious. It is probable that the relative contributions of rare and common variation, as well as environment, differs between ASD families having only a single affected individual (simplex) versus multiplex families who have two or more affected individuals. Methods By using quantitative genetics techniques and the contrast of ASD subjects to controls, we estimate what portion of liability can be explained by additive genetic effects, known as narrow-sense heritability. We evaluate relatives of ASD subjects using the same methods to evaluate the assumptions of the additive model and partition families by simplex/multiplex status to determine how heritability changes with status. Results By analyzing common variation throughout the genome, we show that common genetic polymorphism exerts substantial additive genetic effects on ASD liability and that simplex/multiplex family status has an impact on the identified composition of that risk. As a fraction of the total variation in liability, the estimated narrow-sense heritability exceeds 60% for ASD individuals from multiplex families and is approximately 40% for simplex families. By analyzing parents, unaffected siblings and alleles not transmitted from parents to their affected children, we conclude that the data for simplex ASD families follow the expectation for additive models closely. The data from multiplex families deviate somewhat from an additive model, possibly due to parental assortative mating. Conclusions Our results, when viewed in the context of results from genome-wide association studies, demonstrate that a myriad of common variants of very small effect impacts ASD liability.http://deepblue.lib.umich.edu/bitstream/2027.42/112370/1/13229_2012_Article_55.pd

    Common Genetic Variants, Acting Additively, Are a Major Source of Risk for Autism

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    Background: Autism spectrum disorders (ASD) are early onset neurodevelopmental syndromes typified by impairments in reciprocal social interaction and communication, accompanied by restricted and repetitive behaviors. While rare and especially de novo genetic variation are known to affect liability, whether common genetic polymorphism plays a substantial role is an open question and the relative contribution of genes and environment is contentious. It is probable that the relative contributions of rare and common variation, as well as environment, differs between ASD families having only a single affected individual (simplex) versus multiplex families who have two or more affected individuals. Methods: By using quantitative genetics techniques and the contrast of ASD subjects to controls, we estimate what portion of liability can be explained by additive genetic effects, known as narrow-sense heritability. We evaluate relatives of ASD subjects using the same methods to evaluate the assumptions of the additive model and partition families by simplex/multiplex status to determine how heritability changes with status. Results: By analyzing common variation throughout the genome, we show that common genetic polymorphism exerts substantial additive genetic effects on ASD liability and that simplex/multiplex family status has an impact on the identified composition of that risk. As a fraction of the total variation in liability, the estimated narrow-sense heritability exceeds 60% for ASD individuals from multiplex families and is approximately 40% for simplex families. By analyzing parents, unaffected siblings and alleles not transmitted from parents to their affected children, we conclude that the data for simplex ASD families follow the expectation for additive models closely. The data from multiplex families deviate somewhat from an additive model, possibly due to parental assortative mating. Conclusions: Our results, when viewed in the context of results from genome-wide association studies, demonstrate that a myriad of common variants of very small effect impacts ASD liability
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