135 research outputs found

    An improved stress corrosion test medium for aluminum alloys

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    A laboratory test method that is only mildly corrosive to aluminum and discriminating for use in classifying the stress corrosion cracking resistance of aluminum alloys is presented along with the method used in evaluating the media selected for testing. The proposed medium is easier to prepare and less expensive than substitute ocean water

    Improving the Success of Transfer Students: Responding to Risk Factors

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    How can learning communities be designed to reduce transfer student stress and enhance their learning? This study was designed to investigate the impact of the Criminal Justice Transfer Learning Community experience on its participants’ level of identified stressors over time and their means of coping with those stressors. The Criminal Justice Transfer Learning Community extended for two terms, and was designed to facilitate students’ integration into the university and the criminal justice community. Students in the learning community were asked on multiple occasions to identify stressors and rate their intensity. According to the students, the largest impact on stress reduction was the feeling of belonging to their learning community cohort and the university community

    Combined in situ experimentation and modelling approaches to disentangle processes involved in the earliest stage of community assembly

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    The ecological process of community assembly is described as the succession of three phases: colonization, regulation and segregation. Early colonization remains the least studied and quantified phase of assembly. In order to fill this gap, an approach combining in situ experiments and modelling was proposed to study colonization by a benthic macrofauna community in open microcosms containing a single, non-limiting resource. The experiment was three months long. A total of 51 taxa were observed in the microcosms, but data analyses of the species composition and abundances revealed that five species, Capitella spp., Gammaropsis maculata, Erichtionus punctatus, Nereiphylla paretti and Harmothoe mariannae, explained most of the observed variation in the assembly process. The population dynamics of these species were simulated taking into account functional traits that govern individual interactions. The dynamic model simulated a demographic stochasticity due to low population densities that result from the small size of the experimental microcosms. Using this combined approach of experiments and modelling, we showed that predation interactions alone can account for the abundances and species composition of primary consumers during the transient phase of early colonization

    Quantifying the impact of Psylliodes chrysocephala injury on the productivity of oilseed rape

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    BACKGROUND: Current European Union and United Kingdom legislation prohibits the use of neonicotinoid insecticidal seedtreatments in oilseed rape (OSR,Brassica napus). This ban, and the reduction in efficacy of pyrethroid insecticide sprays dueto resistance, has exacerbated pest pressure from the cabbage stemflea beetle (Psylliodes chrysocephala) in winter OSR. Wequantified the direct impact of P. chrysocephalainjury on the productivity of OSR. Leaf area was removed from young plantsto simulate differing intensities of adult feeding injury alone or in combination with varying larval infestation levels. RESULTS: OSR can compensate for up to 90% leaf area loss at early growth stages, with no meaningful effect on yield. Significant impacts were observed with high infestations of more thanfive larvae per plant; plants were shorter, produced fewerflowers and pods, with fewer seeds per pod which had lower oil content and higher glucosinolate content. Such effects werenot recorded whenfive larvae or fewer were present. CONCLUSION: These data confirm the yield-limiting potential of the larval stages ofP. chrysocephalabut suggest that the current action thresholds which trigger insecticide application for both adult and larval stages (25% leaf area loss andfive larvae/plant, respectively) are potentially too low as they are below the physiological injury level where plants can fully compensatefor damage. Further research infield conditions is needed to define physiological thresholds more accurately as disparity mayresult in insecticide applications that are unnecessary to protect yield and may in turn exacerbate the development and spread of insecticide resistance in P. chrysocephala

    Integrated pest management strategies for cabbage stem flea beetle (Psylliodes chrysocephala) in oilseed rape

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    Oilseed rape (OSR) is the second largest source of vegetable oil globally and the most important biofuel feedstock in the European Union (EU) but production of this important crop is threatened by a small insect; Psylliodes chrysocepaha – the cabbage stem flea beetle (CSFB). The EU ban on use of neonicotinoid seed treatments and resistance of CSFB to pyrethroid insecticides have left farmers with limited control options resulting in drastic reductions in production. Integrated pest management (IPM) may offer a solution. We review the lifecycle of CSFB and the current options available, or in the research pipeline, for the eight IPM principles of the EU Sustainable Use of Pesticides Directive (Directive-2009/128/EC). A full IPM strategy for CSFB barely exists. Although there are a range of preventative measures these require scientific validation; critically, resistant/tolerant OSR cultivars are not yet available. Existing monitoring methods are time consuming and there are no commercial models to enable decision support based on predictions migration timing or population size. Available thresholds are not based on physiological tolerances of the plant making it hard to adapt them to changing market prices for the crop and costs of control. Non-synthetic alternatives tested and registered for use against CSFB are lacking, making resistance management impossible. CSFB control is therefore dependent upon conservation biocontrol. Natural enemies of CSFB are present, but quantification of their effects is needed and habitat management strategies to exploit their potential. Although some EU countries have local initiatives to reduce insecticide use and encourage use of ‘greener’ alternatives, there is no formal process for ranking these and little information available to help farmers make choices. We summarise the main knowledge gaps and future research needed to improve measures for CSFB control and to facilitate development of a full IPM strategy for this pest -and sustainable oilseeds production

    Overview of C/C-SiC Composite Development for the Orion Launch Abort System

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    Past and present efforts by the authors to further understanding of the ceramic matrix composite (CMC) material used in the valve components of the Orion Launch Abort System (LAS) Attitude Control Motor (ACM) will be presented. The LAS is designed to quickly lift the Orion Crew Exploration Vehicle (CEV) away from its launch vehicle in emergency abort scenarios. The ACM is a solid rocket motor which utilizes eight throttleable nozzles to maintain proper orientation of the CEV during abort operations. Launch abort systems have not been available for use by NASA on manned launches since the last Apollo ]Saturn launch in 1975. The CMC material, carbon-carbon/silicon-carbide (C/C-SiC), is manufactured by Fiber Materials, Inc. and consists of a rigid 4-directional carbon-fiber tow weave reinforced with a mixed carbon plus SiC matrix. Several valve and full system (8-valve) static motor tests have been conducted by the motor vendor. The culmination of these tests was the successful flight test of the Orion LAS Pad Abort One (PA ]1) vehicle on May 6, 2010. Due to the fast pace of the LAS development program, NASA Marshall Space Flight Center assisted the LAS community by performing a series of material and component evaluations using fired hardware from valve and full ]system development motor tests, and from the PA-1 flight ACM motor. Information will be presented on the structure of the C/C-SiC material, as well as the efficacy of various non ]destructive evaluation (NDE) techniques, including but not limited to: radiography, computed tomography, nanofocus computed tomography, and X-ray transmission microscopy. Examinations of the microstructure of the material via scanning electron microscopy and energy dispersive spectroscopy will also be discussed. The findings resulting from the subject effort are assisting the LAS Project in risk assessments and in possible modifications to the final ACM operational design

    Debate for Civic Learning

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    Yhteisön intressien ja tutkimustavoitteiden integroiminen yhteisötoimintatutkimuksissa

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    Summary: Community action research projects: integrating community interests and research agenda in multicomponent iniatives

    Disciplined into good conduct : Gender constructions of users in a municipal psychiatric context in Sweden

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    Aims and objectives To examine how gendered discursive norms and notions of masculinity and femininity were (re)produced in professional conversations about users of long‐term municipality psychiatric care. Focus is on the staff’s use of language in relation to gender constructions. Background Psychiatric care in Sweden has undergone tremendous changes in recent decades from custodian care in large hospitals to a care mainly located in a municipal context. People who need psychiatric care services often live in supporting houses. In municipal psychiatric care, staff conduct weekly professional meetings to discuss daily matters and the users’ needs. Official reports of the Swedish government have shown that staff in municipal care services treat disabled women and men differently. Studies exploring gender in relation to users of long‐term psychiatric care in municipalities have problematised the care and how staff, through language, construct users’ gender. Therefore, language used by staff is a central tool for ascribing different gender identities of users. Design The content of speech derived from audio recordings were analysed using Foucauldian discursive analysis. The COREQ checklist was used in this article. Results The results indicate that by relying on gender discourses, staff create a conditional care related to how the users should demonstrate good conduct. In line with that, an overall discourse was created: Disciplined into good conduct. It was underpinned by three discourses inherent therein: The unreliable drinker and the confession, Threatened dignity, Doing different femininities. Conclusion The community psychiatric context generates a discourse of conduct in which staff, via spoken language (re)produces gendered patterns and power imbalances as a means to manage daily work routines. Such practices of care, in which constant, nearly panoptic, control despite the intention to promote autonomy, urgently require problematising current definitions of good conduct and normality.Peer reviewe
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