658 research outputs found
Some thoughts on slender all wing supersonic airliners
The design of slender wing, supersonic airliners has been
considered from the viewpoint of obtaining maximum space utilization,
A relationship between direct operating cost on trans-atlantic services
and space utilization has been established, which shows, as might be
expected, that the direct operating costs decrease as the utilization
factor increases.
A penalty associated with a high utility factor is a high wing
loading. This leads to the necessity of using auxiliary lift when high
utilization factors are obtained, It is shown that a propulsive engine
modified to give jet lift at landing and possibly take-off is likely to
be the best means of obtaining auxiliary lift.
The optimum cruise height is less than that corresponding to
maximum lift drag ratio because of the weight penalty associated with
providing adequate thrust.
The integrated layout is not suitable for airliners required to
carry less than a hundred passengers, but becomes extremely attractive
for a very large number of passengers In this case the central part of
the wing area should be of constant depth with a cabin of side by side
multi- bubble form.
The delta planform is not ideal for an integrated layout,
Better space utilization can be obtained using a pointed pear shaped
Planform. Approximate calculations suggest that direct operating costs
of a 120 seat airliner can be reduced by as much as 25% by using this
type of layout
Integrating Life Annuities and Long-Term Care Insurance: Theory, Evidence, Practice, and Policy
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Co-crystal structures of furosemide:urea and carbamazepine:indomethacin determined from powder x-ray diffraction data
Co-crystallization is a promising approach to improving both the solubility and the dissolution rate of active pharmaceutical ingredients. Crystal structure determination from powder diffraction data plays an important role in determining co-crystal structures, especially those generated by mechanochemical means. Here, two new structures of pharmaceutical interest are reported: a 1:1 co‑crystal of furosemide with urea formed by liquid-assisted grinding and a second polymorphic form of a 1:1 co‑crystal of carbamazepine with indomethacin, formed by solvent evaporation. Energy minimization using dispersion-corrected density functional theory was used in finalizing both structures. In the case of carbamazepine:indomethacin, this energy minimization step was essential in obtaining a satisfactory final Rietveld refinement
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CDASH: a cloud-enabled program for structure solution from powder diffraction data
The simulated annealing approach to crystal structure determination from powder diffraction data, as implemented in the DASH program, is readily amenable to parallelization at the individual run level. Very large scale increases in speed of execution can be achieved by distributing individual DASH runs over a network of computers. The CDASH program delivers this by using
scalable on-demand computing clusters built on the Amazon Elastic Compute Cloud service. By way of example, a 360 vCPU cluster returned the crystal structure of racemic ornidazole (Z0 = 3, 30 degrees of freedom) ca 40 times faster than a typical modern quad-core desktop CPU. Whilst used here specifically for DASH, this approach is of general applicability to other packages that are
amenable to coarse-grained parallelism strategies
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The principles underlying the use of powder diffraction data in solving pharmaceutical crystal structures
Solving pharmaceutical crystal structures from powder diffraction data is discussed in terms of the methodologies that have been applied and the complexity of the structures that have been solved. The principles underlying these methodologies are summarized and representative examples of polymorph, solvate, salt and cocrystal structure solutions are provided, together with examples of some particularly challenging structure determinations
Multistage and transmission-blocking targeted antimalarials discovered from the open-source MMV Pandemic Response Box
PTTG1 Levels Are Predictive of Saracatinib Sensitivity in Ovarian Cancer Cell Lines
Src kinase is recognized as a key target for molecular cancer therapy. However, methods to efficiently select patients responsive to Src inhibitors are lacking. We explored the sensitivity of ovarian cancer cell lines to the Src kinase inhibitor saracatinib to identify predictive markers of drug sensitivity using gene microarrays. Pituitary tumor transforming gene 1 (PTTG1) was selected as a potential biomarker as mRNA levels were correlated with saracatinib resistance, as well as higher PTTG1 protein expression. PTTG1 expression was correlated with proliferation, cell division, and mitosis in ovarian cancer tissues data sets. In sensitive cell lines, saracatinib treatment decreased PTTG1 and fibroblast growth factor 2 (FGF2) protein levels. Downregulating PTTG1 by siRNAs increased saracatinib sensitivity in two resistant cell lines. Our results indicate PTTG1 may be a valuable biomarker in ovarian cancer to predict sensitivity to saracatinib, and could form the basis of a targeted prospective saracatinib trial for ovarian cancer
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Encouraging independent thought and learning in first year practical classes
The transition from A-level to degree-level
practical classes then to a research project,
hence from dependent learner to independent
researcher, is a hurdle that all students face
when studying for a chemistry degree. This can
be daunting so any innovations that aid this
transition are of great value. At the University
of Reading, the first year practical course has
been redesigned to facilitate this transition by
embedding independent thought and
experimentation across all chemistry
disciplines (introductory, organic, inorganic
and physical). Examples of experiments that
provide opportunities for independent student
investigation, along with student perceptions of
the experiments of the course, are given. Using
this model for practical-class delivery, student
engagement, confidence, independence and
ultimately preparedness for year 2 were
improved
Community perceptions of bushfire risk
The public often view and evaluate risk differently from researchers and experts. Understanding
how the public construct their perceptions of risk can greatly improve risk communication,
and direct risk reduction strategies most appropriately.
This chapter explores the social construction of risk in two peri-urban bushfire-prone
communities in Queensland. These case studies were undertaken in 2005 using a multiplemethods
approach, which included group interviews with community and fire brigade
members, and a community survey.
While there are common factors that can similarly influence perceptions of bushfire risks
within and between communities, there are often local-based issues unique to a community
that have important implications for bushfire management. Through understanding and
clarifying fire issues in communities, fire managers can address problems affecting bushfire
risk mitigation in their local cOl1ullUnily. Engaging the community through a number of
means could help considerably. The community should be viewed as a resource - communities
have the capacity to act, despite vulnerabilities
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