5,349 research outputs found
Design spectra for 6-regular graphs with 12 vertices
The design spectrum of a simple graph is the set of positive integers
such that there exists an edgewise decomposition of the complete graph
into copies of . We compute the design spectra for
7788 6-regular graphs with 12 vertices.Comment: 261 pages. The paper without the appendix will be submitted to a
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Folding model analysis of alpha radioactivity
Radioactive decay of nuclei via emission of particles has been
studied theoretically in the framework of a superasymmetric fission model using
the double folding (DF) procedure for obtaining the -nucleus
interaction potential. The DF nuclear potential has been obtained by folding in
the density distribution functions of the nucleus and the daughter
nucleus with a realistic effective interaction. The M3Y effective interaction
has been used for calculating the nuclear interaction potential which has been
supplemented by a zero-range pseudo-potential for exchange along with the
density dependence. The nuclear microscopic -nucleus potential thus
obtained has been used along with the Coulomb interaction potential to
calculate the action integral within the WKB approximation. This subsequently
yields microscopic calculations for the half lives of decays of
nuclei. The density dependence and the exchange effects have not been found to
be very significant. These calculations provide reasonable estimates for the
lifetimes of radioactivity of nuclei.Comment: 7 pages including 1 figur
Sensitivity-analysis method for inverse simulation application
An important criticism of traditional methods of inverse simulation that are based on the Newton–Raphson algorithm is that they suffer from numerical problems. In this paper these problems are discussed and a new method based on sensitivity-analysis theory is developed and evaluated. The Jacobian matrix may be calculated by solving a sensitivity equation and this has advantages over the approximation methods that are usually applied when the derivatives of output variables with respect to inputs cannot be found analytically. The methodology also overcomes problems of input-output redundancy that arise in the traditional approaches to inverse simulation. The sensitivity- analysis approach makes full use of information within the time interval over which key quantities are compared, such as the difference between calculated values and the given ideal maneuver after each integration step. Applications to nonlinear HS125 aircraft and Lynx helicopter models show that, for this sensitivity-analysis method, more stable and accurate results are obtained than from use of the traditional Newton–Raphson approach
Geometry and Structural Modeling for High-Fidelity Aircraft Conceptual Design Optimization
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140431/1/6.2014-2041.pd
Femtosecond visible transient absorption spectroscopy of Chlorophyll f-containing Photosystem I
Photosystem I (PSI) from Chroococcidiopsis thermalis PCC 7203 grown under far-red light (FRL; >725 nm) contains both chlorophyll a and a small proportion of chlorophyll f. Here, we investigated excitation energy transfer and charge separation using this FRL-grown form of PSI (FRL-PSI). We compared femtosecond transient visible absorption changes of normal, white-light (WL)-grown PSI (WL-PSI) with those of FRL-PSI using excitation at 670 nm, 700 nm, and (in the case of FRL-PSI) 740 nm. The possibility that chlorophyll f participates in energy transfer or charge separation is discussed on the basis of spectral assignments. With selective pumping of chlorophyll f at 740 nm, we observe a final ∼150 ps decay assigned to trapping by charge separation, and the amplitude of the resulting P700+•A1−• charge-separated state indicates that the yield is directly comparable to that of WL-PSI. The kinetics shows a rapid 2 ps time constant for almost complete transfer to chlorophyll f if chlorophyll a is pumped with a wavelength of 670 nm or 700 nm. Although the physical role of chlorophyll f is best supported as a low-energy radiative trap, the physical location should be close to or potentially within the charge-separating pigments to allow efficient transfer for charge separation on the 150 ps timescale. Target models can be developed that include a branching in the formation of the charge separation for either WL-PSI or FRL-PSI
Relationship between brachycephalic airway syndrome and gastrointestinal signs in three breeds of dog
Objectives: To assess the breed-specific prevalence of, and effects of corrective airway surgery on, gastrointestinal signs in French bulldogs, English bulldogs and pugs presenting with brachycephalic airway syndrome to a referral teaching hospital.
Materials and Methods: In this retrospective study, ptyalism, regurgitation and vomiting were graded at presentation using a previously established scoring system. Staphylectomy and nares resection were performed on all dogs. Gastrointestinal signs were re-assessed via telephone follow-up at least 6 weeks after surgery.
Results: Ninety-eight dogs were included: French bulldogs (n=43), English bulldogs (n=12) and pugs (n=43). Overall population prevalence of all gastrointestinal signs was 56%. Breed-specific prevalence for French bulldogs was 93%, English bulldogs 58% and pugs 16%. There was post-surgical clinical improvement in gastrointestinal signs for the whole study population, especially in French bulldogs.
Clinical Significance: The prevalence of gastrointestinal signs in dogs presenting with brachycephalic airway syndrome and improvement in these clinical signs following corrective surgery may vary between breeds
Improving functional annotation for industrial microbes: a case study with Pichia pastoris.
The research communities studying microbial model organisms, such as Escherichia coli or Saccharomyces cerevisiae, are well served by model organism databases that have extensive functional annotation. However, this is not true of many industrial microbes that are used widely in biotechnology. In this Opinion piece, we use Pichia (Komagataella) pastoris to illustrate the limitations of the available annotation. We consider the resources that can be implemented in the short term both to improve Gene Ontology (GO) annotation coverage based on annotation transfer, and to establish curation pipelines for the literature corpus of this organism.We gratefully acknowledge funding from the Wellcome Trust (PomBase and Canto; WT090548MA to SGO), and the EU 7th Framework Programme (BIOLEDGE Contract No: 289126 to SGO).This is the published version distributed under a Creative Commons Attribution License 2.0, which can also be found on the publisher's website at: http://www.sciencedirect.com/science/article/pii/S0167779914001061
Comparison of microanalytical methods for estimating H20 contents of silicic volcanic glasses
Three methods of estimating H20 contents of geologic glasses are compared: (1) ion
microprobe analysis (secondary ion mass spectrometry), (2) Fourier-transform infrared
spectroscopy (FTIR), and (3) electron microprobe analysis using the Na decay-curve method.
Each analytical method has its own advantages under certain conditions, depending
on the relative importance of analytical accuracy, precision, sensitivity, spatial resolution,and convenience, and each is capable of providing reasonably accurate estimates of the H20, or total volatile, content of geologic glasses. The accuracy of ion microprobe analyses
depends critically on the availability of well-characterized hydrous standard glasses. Precision is often better than 0,2 wt% (10). The method provides good spatial resolution (-15
#m) and the capability to determine simultaneously the abundance of other volatile species of interest (e.g., F, B). FTIR spectroscopy provides excellent analytical sensitivity (-10
ppm), accuracy and precision «0.1 wt%), and the capability to determine the abundance
of H20 and C02 species (H20, OH-, C02' eOj-) in analyzed glasses, although the spatial
resolution (> 25-35 #m) is not as good as that of the ion microprobe. The main advantages
of the estimation of H20 contents of hydrous glasses using the electron microprobe are
excellent spatial resolution (- 10 #m) and analytical convenience. The disadvantages are
that accuracy and precision (>0.5 wt%) are not as good as those associated with the other
methods, but, for certain applications, these uncertainties may be acceptable for the estimation of H20 contents of H20-rich (> 1 wt%) samples
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