A feasibility study on using inkjet technology, micropumps, and MEMs as fuel injectors for bipropellant rocket engines

Control over drop size distributions, injection rates, and geometrical distribution of fuel and oxidizer sprays in bi-propellant rocket engines has the potential to produce more efficient, more stable, less polluting rocket engines. This control also offers the potential of an engine that can be throttled, working efficiently over a wide range of output thrusts. Inkjet printing technologies, MEMS fuel atomizers, and piezoelectric injectors similar in concept to those used in diesel engines are considered for their potential to yield a new, more active injection scheme for a rocket engine. Inkjets are found to be unable to pump at sufficient pressures, and have possibly dangerous failure modes. Active injection is found to be feasible if high pressure drop along the injector plate are used. A conceptual design is presented and its basic behavior assessed

The hypoxic transcription factor KlMga2 mediates the response to oxidative stress and influences longevity in the yeast Kluyveromyces lactis

Hypoxia is defined as the decline of oxygen availability, depending on environmental supply and cellular consumption rate. The decrease in O2 results in reduction of available energy in facultative aerobes. The response and/or adaptation to hypoxia and other changing environmental conditions can influence the properties and functions of membranes by modifying lipid composition. In the yeast Kluyveromyces lactis, the KlMga2 gene is a hypoxic regulatory factor for lipid biosynthesis-fatty acids and sterols-and is also involved in glucose signaling, glucose catabolism and is generally important for cellular fitness. In this work we show that, in addition to the above defects, the absence of the KlMGA2 gene caused increased resistance to oxidative stress and extended lifespan of the yeast, associated with increased expression levels of catalase and SOD genes. We propose that KlMga2 might also act as a mediator of the oxidative stress response/adaptation, thus revealing connections among hypoxia, glucose signaling, fatty acid biosynthesis and ROS metabolism in K. lactis

Alternative strategies for the extraction of compounds from natural resources

Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Exploitable compounds from natural resources include polysaccharides, proteins and peptides, gum exudates, lipids, polyphenols and other secondary metabolites. Traditional-water extraction (TWE) of polysaccharides is a time-consuming process that requires high solvent and energy consumptions and generates large amounts of waste. Other bioactive compounds are traditionally extracted with organic solvents or mixtures of organic solvents and water, with or without heat. Subcritical water extraction and hydrolysis have been used as an alternative to traditional solvent extraction for many compounds in different matrices (1). Advantages include absence of chemical solvents, lower solvent costs, lower extraction times at moderate operational conditions, resulting in higher quality extracts. Furthermore, water is a solvent with very interesting properties in subcritical conditions. As temperature increases hydrogen bonds break, significantly decreasing the dielectric constant and the polarity, thus increasing solubility of more hydrophobic compounds. On the other hand water ionization increases (thus increasing H+ and OH- ions concentration), meaning that reactions catalysed by acids or bases, like biomass hydrolysis, are accelerated. [...]info:eu-repo/semantics/publishedVersio

Synergistic association of resveratrol and histone deacetylase inhibitors as treatment in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with motor neuron degeneration, progressive paralysis and finally death. Despite the research efforts, currently there is no cure for ALS. In recent years, multiple epigenetic mechanisms have been associated with neurodegenerative diseases. A pathological role for histone hypoacetylation and the abnormal NF-κB/RelA activation involving deacetylation of lysines, with the exclusion of lysine 310, has been established in ALS. Recent findings indicate that the pathological acetylation state of NF-κB/RelA and histone 3 (H3) occurring in the SOD1(G93A) murine model of ALS can be corrected by the synergistic combination of low doses of the AMP-activated kinase (AMPK)-sirtuin 1 pathway activator resveratrol and the histone deacetylase (HDAC) inhibitors MS-275 (entinostat) or valproate. The combination of the epigenetic drugs, by rescuing RelA and the H3 acetylation state, promotes a beneficial and sexually dimorphic effect on disease onset, survival and motor neurons degeneration. In this mini review, we discuss the potential of the epigenetic combination of resveratrol with HDAC inhibitors in the ALS treatment

AUTOESTIMA E MOTIVAÇÃO

Pensar nos processos de trabalho e o que está atrelado ao seu desenvolvimento é um desafio diário aos gestores, independente da área que estejam atuando. Ao pensar nos fatores que estão implícitos ao desenvolvimento de um processo de trabalho, pode-se pensar primeiramente nas pessoas que desenvolvem determinada atividade, o que está relacionado ao seu sucesso ou não na realização da tarefa. Neste trabalho, buscou-se compreender, junto a uma equipe de uma Unidade Básica de Saúde (UBS), as dimensões que o trabalho abarca quanto à motivação e à autoestima nas atividades que o indivíduo realiza em seu local de trabalho. É um relato de experiência realizado durante o nono semestre do Curso de Psicologia na disciplina de Tópicos Avançados em Psicologia da Saúde II. Para a compreensão desses fatores, utilizou-se uma ferramenta em que os colaboradores pudessem expor suas vivências e os fatores desencadeadores da motivação para o trabalho. A atividade foi realizada com uma equipe de 12 pessoas, resultando no entendimento de que um trabalho em equipe se faz como diferencial na realização das tarefas de todos e não apenas de um colaborador. A área da saúde é um espaço interdisciplinar e abarca diferentes percepções a respeito do desenvolvimento laboral, o que suscita diferentes entendimentos acerca da motivação e autoestima do colaborador, portanto, sugerem-se novas investigações a respeito do tema.Palavras-chave: Autoestima. Motivação. Desenvolvimento

Testing Mass Determinations of Supermassive Black Holes via Stellar Kinematics

We investigate the accuracy of mass determinations M_BH of supermassive black holes in galaxies using dynamical models of the stellar kinematics. We compare 10 of our M_BH measurements, using integral-field OASIS kinematics, to published values. For a sample of 25 galaxies we confront our new M_BH derived using two modeling methods on the same OASIS data.Comment: 4 pages, 4 figures, LaTeX. To appear in "Hunting for the Dark: The Hidden Side of Galaxy Formation", Malta, 19-23 Oct. 2009, eds. V.P. Debattista and C.C. Popescu, AIP Conf. Ser., in pres

Structural basis of membrane disruption and cellular toxicity by α-synuclein oligomers.

Oligomeric species populated during the aggregation process of α-synuclein have been linked to neuronal impairment in Parkinson's disease and related neurodegenerative disorders. By using solution and solid-state nuclear magnetic resonance techniques in conjunction with other structural methods, we identified the fundamental characteristics that enable toxic α-synuclein oligomers to perturb biological membranes and disrupt cellular function; these include a highly lipophilic element that promotes strong membrane interactions and a structured region that inserts into lipid bilayers and disrupts their integrity. In support of these conclusions, mutations that target the region that promotes strong membrane interactions by α-synuclein oligomers suppressed their toxicity in neuroblastoma cells and primary cortical neurons

Efficient vacuum deposited p-i-n and n-i-p perovskite solar cells employing doped charge transport layers

Methylammonium lead halide perovskites have emerged as high performance photovoltaic materials. Most of these solar cells are prepared via solution-processing and record efficiencies (>20%) have been obtained employing perovskites with mixed halides and organic cations on (mesoscopic) metal oxides. Here, we demonstrate fully vacuum deposited planar perovskite solar cells by depositing methylammonium lead iodide in between intrinsic and doped organic charge transport molecules. Two configurations, one inverted with respect to the other, p-i-n and n-i-p, are prepared and optimized leading to planar solar cells without hysteresis and very high efficiencies, 16.5% and 20%, respectively. It is the first time that a direct comparison between these two opposite device configurations has been reported. These fully vacuum deposited solar cells, employing doped organic charge transport layers, validate for the first time vacuum based processing as a real alternative for perovskite solar cell preparation

Additively manufactured custom load-bearing implantable devices

BackgroundAdditive manufacturing technologies are being enthusiastically adopted by the orthopaedic community since they are providing new perspectives and new possibilities. First applications were finalised for educational purposes, pre-operative planning, and design of surgical guides; recent applications also encompass the production of implantable devices where 3D printing can bring substantial benefits such as customization, optimization, and manufacturing of very complex geometries. The conceptual smoothness of the whole process may lead to the idea that any medical practitioner can use a 3D printer and her/his imagination to design and produce novel products for personal or commercial use.AimsOutlining how the whole process presents more than one critical aspects, still demanding further research in order to allow a safe application of this technology for fully-custom design, in particular confining attention to orthopaedic/orthodontic prostheses defined as components responding mainly to a structural function.Methods Current knowledge of mechanical properties of additively manufactured components has been examined along with reasons why the behaviour of these components might differ from traditionally manufactured components. The structural information still missing for mechanical design is outlined.Results Mechanical properties of additively manufactured components are not completely known, and especially fatigue limit needs to be examined further.ConclusionAt the present stage, with reference to load-bearing implants subjected to many loading cycles, the indication of custom-made additively manufactured medical devices should be restricted to the cases with no viable alternative