460 research outputs found
WARDJet Waterjet Cutting Head Actuator Design
In an effort to increase efficiency and productivity, WARDJet was seeking a better actuation method for the cutting head on their waterjets. Current actuation methods were, for the most part, purely mechanical, relying on compressed air, springs, and water pressure to open and close the valve to 60,000 psi of water. Increasing the speed of the on/off cycle times of the waterjet would allow for faster movements of the cutting head from one cut to the next, increasing the overall amount of products cut in a day, week, and year. This obviously points to increased sales, increased profit, and increased customer satisfaction when implemented
A new rhynchocephalian from the late jurassic of Germany with a dentition that is unique amongst tetrapods.
Rhynchocephalians, the sister group of squamates (lizards and snakes), are only represented by the single genus Sphenodon today. This taxon is often considered to represent a very conservative lineage. However, rhynchocephalians were common during the late Triassic to latest Jurassic periods, but rapidly declined afterwards, which is generally attributed to their supposedly adaptive inferiority to squamates and/or Mesozoic mammals, which radiated at that time. New finds of Mesozoic rhynchocephalians can thus provide important new information on the evolutionary history of the group.
A new fossil relative of Sphenodon from the latest Jurassic of southern Germany, Oenosaurus muehlheimensis gen. et sp. nov., presents a dentition that is unique amongst tetrapods. The dentition of this taxon consists of massive, continuously growing tooth plates, probably indicating a crushing dentition, thus representing a previously unknown trophic adaptation in rhynchocephalians.
The evolution of the extraordinary dentition of Oenosaurus from the already highly specialized Zahnanlage generally present in derived rhynchocephalians demonstrates an unexpected evolutionary plasticity of these animals. Together with other lines of evidence, this seriously casts doubts on the assumption that rhynchocephalians are a conservative and adaptively inferior lineage. Furthermore, the new taxon underlines the high morphological and ecological diversity of rhynchocephalians in the latest Jurassic of Europe, just before the decline of this lineage on this continent. Thus, selection pressure by radiating squamates or Mesozoic mammals alone might not be sufficient to explain the demise of the clade in the Late Mesozoic, and climate change in the course of the fragmentation of the supercontinent of Pangaea might have played a major role
Aerospace Fuels From Nonpetroleum Raw Materials
Recycling human metabolic and plastic wastes minimizes cost and increases efficiency by reducing the need to transport consumables and return trash, respectively, from orbit to support a space station crew. If the much larger costs of transporting consumables to the Moon and beyond are taken into account, developing waste recycling technologies becomes imperative and possibly mission enabling. Reduction of terrestrial waste streams while producing energy and/or valuable raw materials is an opportunity being realized by a new generation of visionary entrepreneurs; several relevant technologies are briefly compared, contrasted and assessed for space applications. A two-step approach to nonpetroleum raw materials utilization is presented; the first step involves production of supply or producer gas. This is akin to synthesis gas containing carbon oxides, hydrogen, and simple hydrocarbons. The second step involves production of fuel via the Sabatier process, a methanation reaction, or another gas-to-liquid technology, typically Fischer-Tropsch processing. Optimization to enhance the fraction of product stream relevant to transportation fuels via catalytic (process) development at NASA Glenn Research Center is described. Energy utilization is a concern for production of fuels whether for operation on the lunar or Martian surface, or beyond. The term green relates to not only mitigating excess carbon release but also to the efficiency of energy usage. For space, energy usage can be an essential concern. Another issue of great concern is minimizing impurities in the product stream(s), especially those that are potential health risks and/or could degrade operations through catalyst poisoning or equipment damage; technologies being developed to remove heteroatom impurities are discussed. Alternative technologies to utilize waste fluids, such as a propulsion option called the resistojet, are discussed. The resistojet is an electric propulsion technology with a powered thruster to vaporize and heat a propellant to high temperature, hot gases are subsequently passed through a converging-diverging nozzle expanding gases to supersonic velocities. A resistojet can accommodate many different fluids, including various reaction chamber (by-)products
The higher-level phylogeny of Archosauria (Tetrapoda:Diapsida)
Crown group Archosauria, which includes birds, dinosaurs, crocodylomorphs, and several extinct Mesozoic groups, is a primary division of the vertebrate tree of life. However, the higher-level phylogenetic relationships within Archosauria are poorly resolved and controversial, despite years of study. The phylogeny of crocodile-line archosaurs (Crurotarsi) is particularly contentious, and has been plagued by problematic taxon and character sampling. Recent discoveries and renewed focus on archosaur anatomy enable the compilation of a new dataset, which assimilates and standardizes character data pertinent to higher-level archosaur phylogeny, and is scored across the largest group of taxa yet analysed. This dataset includes 47 new characters (25% of total) and eight taxa that have yet to be included in an analysis, and total taxonomic sampling is more than twice that of any previous study. This analysis produces a well-resolved phylogeny, which recovers mostly traditional relationships within Avemetatarsalia, places Phytosauria as a basal crurotarsan clade, finds a close relationship between Aetosauria and Crocodylomorpha, and recovers a monophyletic Rauisuchia comprised of two major subclades. Support values are low, suggesting rampant homoplasy and missing data within Archosauria, but the phylogeny is highly congruent with stratigraphy. Comparison with alternative analyses identifies numerous scoring differences, but indicates that character sampling is the main source of incongruence. The phylogeny implies major missing lineages in the Early Triassic and may support a Carnian-Norian extinction event.Marshall Scholarship for study in the United KingdomJurassic FoundationUniversity of BristolPaleontological Societ
Cerium Oxide Nanoparticles Protect Cardiac Progenitor Cells from Oxidative Stress
Cardiac progenitor cells (CPCs) are a promising autologous source of cells for cardiac
regenerative medicine. However, CPC culture in vitro requires the presence of microenvironmental
conditions (a complex array of bioactive substance concentration, mechanostructural
factors, and physicochemical factors) closely mimicking the natural cell surrounding in vivo,
including the capability to uphold reactive oxygen species (ROS) within physiological levels
in vitro. Cerium oxide nanoparticles (nanoceria) are redox-active and could represent a potent
tool to control the oxidative stress in isolated CPCs. Here, we report that 24 h exposure to 5, 10,
and 50 !g/mL of nanoceria did not a!ect cell growth and function in cardiac progenitor cells,
while being able to protect CPCs from H2O2-induced cytotoxicity for at least 7 days, indicating
that nanoceria in an e!ective antioxidant. Therefore, these "ndings con"rm the great
potential of nanoceria for controlling ROS-induced cell damage
Determination of interfacial shear strength in epoxy/glass composites by multi-fiber fragmentation test (MFFT)
Guidelines of the Brazilian Association of Studies on Alcohol and Other Drugs (ABEAD) for diagnoses and treatment of psychiatric comorbidity with alcohol and other drugs dependence
Recently, several studies have focused on comorbity psychiatric disorders with alcohol and other substance dependence. The Brazilian Association of Studies on Alcohol and Other Drugs proposed the Brazilian Guidelines project. This study review diagnostic and therapeutic criteria to the most prevalent psychiatric comorbidities. Randomized clinical trials, epidemiological, animal studies and other forms of research are reviewed. The main psychiatric comorbidities are studied based on guidelines adopted by other countries and the literature data resumed. Epidemiological aspects, diagnoses, integrated treatment and service organization, as well as specific psychotherapic and pharmacological treatment are discussed. The Brazilian Association of Studies on Alcohol and Other Drugs Guidelines reassures the importance of adequate diagnoses and treatment regarding alcoholic and drug dependent patients suffering of comorbid psychiatric disorders.O diagnóstico e tratamento de comorbidade psiquiátrica e dependência de álcool e outras substâncias tem sido objeto de inúmeros estudos nos últimos anos. A Associação Brasileira de Estudos do Álcool e Outras Drogas desenvolveu o projeto Diretrizes. Este trabalho visa o desenvolvimento de critérios diagnósticos e terapêuticos atualizados para as comorbidades psiquiátricas mais prevalentes. Ensaios clínicos randomizados, estudos epidemiológicos, com animais e outros estudos são revisados. As principais comorbidades psiquiátricas são estudadas e os dados de literatura resumidos, tendo como referência diretrizes adotadas em outros países. São abordados aspectos epidemiológicos, critérios diagnósticos, tratamento integrado e organização de serviço especializado, assim como especificidades do tratamento psicoterápico e farmacológico. As Diretrizes da Associação Brasileira de Estudos do Álcool e Outras Drogas reforçam a importância da abordagem adequada do dependente químico portador de comorbidade psiquiátrica.Universidade Federal de Santa Catarina Núcleo de PsiquiatriaInstituto de Psiquiatria de Santa CatarinaUniversidade Federal de São Paulo (UNIFESP) Unidade de Pesquisa em Álcool e DrogasSanta Casa de Misericórdia de São Paulo Unidade de Álcool e DrogasUniversidade de São Paulo Faculdade de Medicina Hospital das ClinicasCentro de Atendimento Médico e SocialHospital de Clínicas de Porto AlegreHospital Israelita Albert EinsteinSanta Casa do Rio de Janeiro Setor de Dependência QuímicaUniversidade Gama FilhoUNIFESP, Unidade de Pesquisa em Álcool e DrogasSciEL
Determination of interfacial shear strength in epoxy/glass composites by multi-fiber fragmentation test (MFFT)
The mechanical strength of a structural composite is strongly affected by the strength and toughness of the interface achieved between the continuous matrix phase, or resin, and the reinforcing phase, normally consisting of multiple arrays of carbon or glass fibers. Interfacial shear strength (IFSS) is the accepted parameter for quantifying the strength of the matrix-fiber interface. However, the value of IFSS is not directly accessible by measurement and must be approximated indirectly from other dat
An examination of psychopathology among men who have suspended the use of violence in their intimate relationships
It is well established that personality pathology has been associated with the onset and continued perpetration of intimate partner violence, yet if and how this relates to the cessation of such behaviours remains unclear. The aim of this study was to determine whether personality pathology differentiated 37 intimate partner violent men who had suspended the use of violence against their intimates (‘desisters’), 50 persisters, and 49 non-violent controls using the Millon Clinical Multiaxial Inventory-III subscales. Cluster A and Cluster B disorders at a diagnostic level were more often reported in men who had used violence against intimates compared to men in the control group. The rates and percentages of clinically meaningful traits and disorders were lower for the desisters than the persisters, with the desisters more like the controls than the persisters. The findings suggest that the initial stage of the desistance process may be related to personality pathology
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