24,278 research outputs found
Developments in steady and unsteady aerodynamics for use in aeroelastic analysis and design
A review is given of seven research projects which are aimed at improving the generality, accuracy, and computational efficiency of steady and unsteady aerodynamic theory for use in aeroelastic analysis and design. These projects indicate three major thrusts of current research efforts: (1) more realistic representation of steady and unsteady subsonic and supersonic loads on aircraft configurations of general shape with emphasis on structural-design applications, (2) unsteady aerodynamics for application in active-controls analyses, and (3) unsteady aerodynamics for the frequently critical transonic speed range. The review of each project includes theoretical background, description of capabilities, results of application, current status, and plans for further development and use
Access courses as a site of engagement: a research project
This research project was funded by the Greater Manchester Strategic Alliance and Aimhigher Research Network North West. A database of Access students was held at the University of Salford that included students from 1998-2006. The names of the students were gathered by the Access Unit from their Enrichment Programme over the period. Ethical approval for the research was sought from the IRIS Director and advice on the Data Protection Act sought from the manager responsible within the university. The database contained information on name, age, address, telephone contact, gender, ethnicity, college and Access course attended. There were approximately 6000 entries on the database.
“Access to higher education courses offer a route into higher education (HE) for those who do not have the educational qualifications which are usually required for entry. These courses provide the underpinning knowledge and skills needed for university-level study, and lead to the award of the Access to HE qualification, which is of an equivalent standard to Level 3 qualifications, such as A levels.” UCAS website.
Individuals can study a range of courses in different subject areas such as health, science or humanities. Access courses can be studied over one year as a full time course or over two-three years as a part time course. The starting point for the study is the view that to enrol on an Access to HE course means that a major decision or turning point in an adult’s life has taken place and that the individual wants to change direction. This change of direction is important and suggests that individuals may have missed an opportunity earlier in their lives or do not wish to continue in the same employment situation or in the case of many women who are carers their circumstances have changed. The engagement in learning is an agentic act on the part of the individual that may be prompted by others in the immediate family or friends. However, a necessary aspect of this engagement is the provision of Access courses as a means to enter higher education or change employment
Mapping CS in Starburst Galaxies: Disentangling and Characterising Dense Gas
Aims. We observe the dense gas tracer CS in two nearby starburst galaxies to
determine how the conditions of the dense gas varies across the circumnuclear
regions in starburst galaxies. Methods. Using the IRAM-30m telescope, we mapped
the distribution of the CS(2-1) and CS(3-2) lines in the circumnuclear regions
of the nearby starburst galaxies NGC 3079 and NGC 6946. We also detected the
formaldehyde (H2CO) and methanol (CH3OH) in both galaxies. We marginally detect
the isotopologue C34S. Results. We calculate column densities under LTE
conditions for CS and CH3OH. Using the detections accumulated here to guide our
inputs, we link a time and depth dependent chemical model with a molecular line
radiative transfer model; we reproduce the observations, showing how conditions
where CS is present are likely to vary away from the galactic centres.
Conclusions. Using the rotational diagram method for CH3OH, we obtain a lower
limit temperature of 14 K. In addition to this, by comparing the chemical and
radiative transfer models to observations, we determine the properties of the
dense gas as traced by CS (and CH3OH). We also estimate the quantity of the
dense gas. We find that, provided that there are a between 10^5 and 10^6 dense
cores in our beam, for both target galaxies, emission of CS from warm (T = 100
- 400 K), dense (n(H2) = 10^5-6 cm-3) cores, possibly with a high cosmic ray
ionisation rate (zeta = 100 zeta0) best describes conditions for our central
pointing. In NGC 6946, conditions are generally cooler and/or less dense
further from the centre, whereas in NGC 3079, conditions are more uniform. The
inclusion of shocks allows for more efficient CS formation, leading to an order
of magnitude less dense gas being required to replicate observations in some
cases.Comment: 14 pages, 10 figures, accepted to A&
Identification of novel chondroitin proteoglycans in Caenorhabditis elegans: embryonic cell division depends on CPG-1 and CPG-2.
Vertebrates produce multiple chondroitin sulfate proteoglycans that play important roles in development and tissue mechanics. In the nematode Caenorhabditis elegans, the chondroitin chains lack sulfate but nevertheless play essential roles in embryonic development and vulval morphogenesis. However, assignment of these functions to specific proteoglycans has been limited by the lack of identified core proteins. We used a combination of biochemical purification, Western blotting, and mass spectrometry to identify nine C. elegans chondroitin proteoglycan core proteins, none of which have homologues in vertebrates or other invertebrates such as Drosophila melanogaster or Hydra vulgaris. CPG-1/CEJ-1 and CPG-2 are expressed during embryonic development and bind chitin, suggesting a structural role in the egg. RNA interference (RNAi) depletion of individual CPGs had no effect on embryonic viability, but simultaneous depletion of CPG-1/CEJ-1 and CPG-2 resulted in multinucleated single-cell embryos. This embryonic lethality phenocopies RNAi depletion of the SQV-5 chondroitin synthase, suggesting that chondroitin chains on these two proteoglycans are required for cytokinesis
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