611 research outputs found

    Rolling moments in a trailing vortex flow field

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    Pressure distributions are presented which were measured on a wing in close proximity to a tip vortex of known structure generated by a larger, upstream semispan wing. Overall loads calculated by integration of these pressures are checked by independent measurements made with an identical model mounted on a force balance. Several conventional methods of wing analysis are used to predict the loads on the following wing. Strip theory is shown to give uniformly poor results for loading distribution, although predictions of overall lift and rolling moment are sometimes acceptable. Good results are obtained for overall coefficients and loading distribution by using linearized pressures in vortex-lattice theory in conjunction with a rectilinear vortex. The equivalent relation from reverse-flow theory that can be used to give economic predictions for overall loads is presented

    Assessment of a wake vortex flight test program

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    A proposed flight test program to measure the characteristics of wake vortices behind a T-33 aircraft was investigated. A number of facets of the flight tests were examined to define the parameters to be measured, the anticipated vortex characteristics, the mutual interference between the probe aircraft and the wake, the response of certain instruments to be used in obtaining measurements, the effect of condensation on the wake vortices, and methods of data reduction. Recommendations made as a result of the investigation are presented

    On Followership

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    Followers are an essential but underrepresented part of leadership. Without a strong group of followers, leaders cannot possibly be successful. Followers can, and often do, think independently and critically, and are active workers. They do not simply wait to be told what to do. level followers courageous Instead, there are various followership styles. At the most exemplary provide are fully relationship constructive, competent with leaders although not partners wherein in an they always positive, organization. are able feedback. to They openly Effective maintain disagree leaders a and work with followers, not above them, and empower them to take risks. Organizations should maintain a culture that recognizes the value that followers bring to achieving the overall goals of the organization. This literature review presents several models and theories that focus on followership and offers recommendations to organizations, leaders, and followers that assist stakeholders at all levels of an organization in sustaining a culture of followership

    Grinding-induced metallurgical alterations in the binder phase of WC-Co cemented carbides

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    The metallic binder phase dictates the toughening behavior of WC-Co cemented carbides (hardmetals), even though it occupies a relative small fraction of the composite. Studies on deformation and phase transformation of the binder constituent are scarce. Grinding represents a key manufacturing step in machining of hardmetal tools, and is well-recognized to induce surface integrity alterations. In this work, metallurgical alterations of the binder phase in ground WC-Co cemented carbides have been assessed by a combination of electron back scattered diffraction and transmission electron microscopy techniques. The Co-base binder experiences a martensitic phase transformation from fcc to hcp crystal structure, predominantly in the first 5 µm below the surface. The hcp fraction decreases gradually along a depth of 10 µm. Surface Co displays severe plastic deformation under the highest strain, resulting in formation of nanocrystalline grains in the first micrometer below the surface. Microstructural refinement within the binder phase is observed even at greater depth. Stacking faults were detected in most of the refined grains. The metallurgical alterations of the binder phase modify the local stress distribution during grinding, which affects the discerned subsurface microcracking. The resulting residual stress profile is the sum of multiple subsurface changes, such as phase transformation, severe plastic deformation and grain refinement, where it is discerned that the depth profile of the transformed hcp-Co fraction coincides with the grinding-induced residual stress profile.Peer ReviewedPostprint (author's final draft

    The HERMES Back Drift Chambers

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    The tracking system of the HERMES spectrometer behind the bending magnet consists of two pairs of large planar 6-plane drift chambers. The design and performance of these chambers is described. This description comprises details on the mechanical and electronical design, information about the gas mixture used and its properties, results on alignment, calibration, resolution, and efficiencies, and a discussion of the experience gained through the first three years of operation.Comment: 21 pages, LaTex, 16 figures include

    Generic Modal Cut Elimination Applied to Conditional Logics

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    We develop a general criterion for cut elimination in sequent calculi for propositional modal logics, which rests on absorption of cut, contraction, weakening and inversion by the purely modal part of the rule system. Our criterion applies also to a wide variety of logics outside the realm of normal modal logic. We give extensive example instantiations of our framework to various conditional logics. For these, we obtain fully internalised calculi which are substantially simpler than those known in the literature, along with leaner proofs of cut elimination and complexity. In one case, conditional logic with modus ponens and conditional excluded middle, cut elimination and complexity were explicitly stated as open in the literature

    Long-lifetime, reliable liquid metal ion sources for boron, arsenic, and phosphorus

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    Operation of liquid–metalion sources based on palladium alloys that contain boron, arsenic, and phosphorus (singly or in combination) was studied. These sources, when run on refractory metal needles and heater ribbons, have exhibited high angular intensity (1.5–5 μA/sr), long lifetime (\u3e150 h), low energy spread (eV), and stable operation with extracted currents down to 2 μA

    Identification of SOX2 as a novel glioma-associated antigen and potential target for T cell-based immunotherapy

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    Prognosis for patients suffering from malignant glioma has not substantially improved. Specific immunotherapy as a novel treatment concept critically depends on target antigens, which are highly overexpressed in the majority of gliomas, but the number of such antigens is still very limited. SOX2 was identified by screening an expression database for transcripts that are overexpressed in malignant glioma, but display minimal expression in normal tissues. Expression of SOX2 mRNA was further investigated in tumour and normal tissues by real-time PCR. Compared to cDNA from pooled normal brain, SOX2 was overexpressed in almost all (9 out of 10) malignant glioma samples, whereas expression in other, non-malignant tissues was almost negligible. SOX2 protein expression in glioma cell lines and tumour tissues was verified by Western blot and immunofluorescence. Immunohistochemistry demonstrated SOX2 protein expression in all malignant glioma tissues investigated ranging from 6 to 66% stained tumour cells. Human leucocyte antigen-A*0201-restricted SOX2-derived peptides were tested for the activation of glioma-reactive CD8+ cytotoxic T lymphocytes (CTLs). Specific CTLs were raised against the peptide TLMKKDKYTL and were capable of lysing glioma cells. The abundant and glioma-restricted overexpression of SOX2 and the generation of SOX2-specific and tumour-reactive CTLs may recommend this antigen as target for T-cell-based immunotherapy of glioma

    When Can Employees Have a Family Life? The Effects of Daily Workload and Affect on Work-Family Conflict and Social Behaviors at Home

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    This article presents a longitudinal examination of antecedents and outcomes of work-to-family conflict. A total of 106 employees participating in an experience-sampling study were asked to respond to daily surveys both at work and at home, and their spouses were interviewed daily via telephone for a period of 2 weeks. Intraindividual analyses revealed that employees ’ perceptions of workload predicted work-to-family conflict over time, even when controlling for the number of hours spent at work. Workload also influenced affect at work, which in turn influenced affect at home. Finally, perhaps the most interesting finding in this study was that employees ’ behaviors in the family domain (reported by spouses) were predicted by the employees ’ perceptions of work-to-family conflict and their positive affect at home

    The influence of abiotic factors on the presence of European corn borer (Ostrinia nubilalis Hübner)

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    Istraživanja su provedena tijekom trogodišnjeg razdoblja (2012. – 2014.) u poljskim uvjetima s prirodnom zarazom kukuruznoga moljca, na Poljoprivrednom institutu u Osijeku. Cilj istraživanja bio je utvrditi utjecaj različitih varijanti navodnjavanja i gnojidbe i utjecaj genotipa na pojavu i oštećenost biljki od kukuruznoga moljca te povezanost ishrane gusjenica s koncentracijom dušika, silicija i C/N odnosa u listu kukuruza. Na kraju svake vegetacijske sezone zabilježena je masa klipa (g), dužina oštećenja stabljike (cm), oštećenje drške klipa (cm), broj gusjenica u stabljici kukuruza, broj gusjenica u dršci klipa, te ukupan broj gusjenica po biljci. U 2014. godini kada su bile niže temperature, a veća količina oborina utvrđen je značajno niži napad u odnosu na druge dvije ispitivane godine. Uz pomoć feromonskih mamaca utvrđena je dominantnost Z-tipa kukuruznoga moljca na području istočne Slavonije. Povišenom razinom sadržaja vode u tlu utvrdilo se manje oštećenje biljke, a povećanjem razine gnojidbe utvrđeno je veće oštećenje na biljkama kao posljedica ishrane gusjenica. Utvrđena je različita otpornost hibrida u odnosu na oštećenje od gusjenica te se hibrid C4 izdvojio kao najotporniji, dok je C1 bio najosjetljiviji. Koncentracija dušika i silicija u listu kukuruza u negativnoj su korelaciji kao i koncentracija dušika i C/N odnos. Otpornost kod hibrida nije isključivo ovisila o koncentracijama dušika i silicija iako se pokazalo kod većine hibrida pri povećanoj koncentraciji dušika veće oštećenje, a kod povećane koncentracije silicija utvrđeno je manje oštećenje.Field experiments with natural population of ECB were conducted in three vegetation seasons (2012-2014) at the Agricultural Institute in Osijek. The aim of this study was to determine the effect of different levels of irrigation and nitrogen fertilization and various genotypes on the occurrence and damage of maize plants from European corn borer larvae and relationship with nitrogen and silicon content as well as C/N ratio. At the end of each growing season were determined ear weight (g), tunnel length (stalk) (cm), ear shank damage (cm), the number of larvae in corn stalk, number of larvae in the ear shank, and total number of larvae in plant. In 2014, with lower temperatures and higher amount of precipitate compared to the previous years, a significantly lower ECB attack was determined. Dominance of Z-type European corn borer on pheromone traps in the area of eastern Slavonia was determined. Increasing the level of soil water content damage from larvae was reduced and increasing the level of nitrogen fertilization feeding activity was increased. We have confirmed different hybrid resistance in regards to damage from larvae, so C4 genotype was the most resistant while C1 was the most susceptible. Concentration of nitrogen and silicon in a maize leaf were in negative correlation as well as nitrogen concentration and C/N ratio. Hybrid resistance didn't entirely depend on nitrogen and silicon concentrations, even though there was greater damage at most hybrids with higher concentration of nitrogen, while damage was reduced with higher concentration of silicon
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