2,195 research outputs found
XP : good for anything other than software development?
No full textThe author implemented XP practices in both hardware and software development projects as well as using them as guidelines for general department management. This paper describes the reasoning behind this decision and the most important results
Transient effect on ideally plastic stationary crack-tip fields
No full textThis paper analyses the transient effect on ideally plastic stationary crack tip fields under mode I plane strain conditions, when the inertial forces are not negligible. It is shown that the governing equation for such a problem can be expressed in formal simplicity when referred to a system of moving curvilinear coordinates, which is a generalization of the system defined by the slip-line field in quasi-static plasticity. A perturbation method of solving the equations is described and illustrated by application to problems of ideally plastic stationary crack tip fields when the inertial forces are not negligible
Extracting stellar emissivity via a machine learning analysis of MSX and LAMOST catalog data
No full textMany astronomical studies model stars like radiating blackbodies with
unit emissivity. Their conclusions should be reconsidered if the stellar
spectral emissivity, epsilon lambda, were to be proven to be appreciably
smaller. However, determining epsilon lambda from raw observational data
poses serious technical challenges. Here, using a machine learning
technique, we implemented an inverse model for calculating the stellar
spectral radiation flux in a given spectral band emissivity. Radiation
flux data in some spectral bands serve as input to determine the unknown
model parameters. To this purpose, we chose 411 stars (361 from the
Midcourse Space Experiment (MSX) catalog and 50 from the Large Sky Area
Multi-Object Fiber Spectroscopic Telescope (LAMOST) catalog) as training
samples of a stochastic particle swarm optimization algorithm. The mean
values of the emissivity estimates thus obtained deviate significantly
from the ideal blackbody value. Knowledge of the model parameters then
enabled us to calculate the radiation fluxes in other spectral bands to
compare with the existing observational data and thus validate our
approach. Finally, based on the trained algorithm, we discuss our
predictions for spectral bands where astronomical data are unavailable.
Besides providing direct evidence against modeling stars as emitting
blackbodies, our conclusions also call for more direct investigations of
the stellar emissivity
Photocleavable fluorescent nucleotides for DNA sequencing on a chip constructed by site-specific coupling chemistry
No full textDNA sequencing by synthesis on a solid surface offers new paradigms to overcome limitations of electrophoresis-based sequencing methods. Here we report DNA sequencing by synthesis using photocleavable (PC) fluorescent nucleotides [dUTP-PC-4,4-difluoro-4-bora-3alpha,4alpha-diaza-s-indacene (Bodipy)-FL-510, dCTP-PC-Bodipy-650, and dUTP-PC-6-carboxy-X-rhodamine (ROX)] on a glass chip constructed by 1,3-dipolar azide-alkyne cycloaddition coupling chemistry. Each nucleotide analogue consists of a different fluorophore attached to the base through a PC 2-nitrobenzyl linker. We constructed a DNA microarray by using the 1,3-dipolar cycloaddition chemistry to site-specifically attach azido-modified DNA onto an alkyne-functionalized glass chip at room temperature under aqueous conditions. After verifying that the polymerase reaction could be carried out successfully on the above-described DNA array, we then performed a sequencing reaction on the chip by using a self-primed DNA template. In the first step, we extended the primer using DNA polymerase and dUTP-PC-Bodipy-FL-510, detected the fluorescent signal from the fluorophore Bodipy-FL-510, and then cleaved the fluorophore using 340 nm UV irradiation. This process was followed by extension of the primer with dCTP-PC-Bodipy-650 and the subsequent detection of the fluorescent signal from Bodipy-650 and its photocleavage. The same procedure was also performed by using dUTP-PC-ROX. The entire process was repeated five times by using the three fluorescent nucleotides to identify 7 bases in the DNA template. These results demonstrate that the PC nucleotide analogues can be incorporated accurately into a growing DNA strand during polymerase reaction on a chip, and the fluorophore can be detected and then efficiently cleaved using near-UV irradiation, thereby allowing the continuous identification of the template sequence.National Science Foundation Sensing and Imaging Initiative Grant 0097793, a Packard Fellowship for Science and Engineering, Center of Excellence in Genomic Science Grant P50 HG002806 from National Institutes of Healt
The pragmatic effects of Macedonian li: An empirical study
No full textIn this paper we provide empirical data concerning the pragmatics of the particle li following nominal phrases in polar questions in Macedonian. Since in previous literature li has been analyzed as a focus particle, we put forward two hypotheses on its effect in questions that can follow from focus marking: (i) that li signals uniqueness of the entity that is denoted by the constituent it is attached to or (ii) that li signals surprise about the entity denoted by the constituent it is attached to. We have conducted an online survey that shows that polar questions in which li is adjacent to a fronted XP are felicitous in contexts containing surprise, regardless of whether that XP is unique or not. We account for these findings using questions under discussion and alternative semantics
Data file for the paper: Jun Wu, Peng Li, Andres Parra-Puerto, Shuang Wu, Xiaoqian Lin, Denis Kramer, Shengli Chen, Anthony Kucernak, "Controllable heteroatom doping effects of CrxCo2-xP Nanoparticles: A Robust Electrocatalyst for Overall Water Splitting in Alkaline Solutions"
No full textThe data in this spreadsheet was used to produce the figures in the paper
Authors:Jun Wu,Peng Li,Andres Parra-Puerto,Shuang Wu,Xiaoqian Lin,Denis Kramer,Shengli Chen,Anthony Kucernak
Title:Controllable heteroatom doping effects of CrxCo2-xP Nanoparticles: A Robust Electrocatalyst for Overall Water Splitting in Alkaline Solutions
Journal:Acs Applied Materials & Interfaces
DOI: 10.1021/acsami.0c10441
Please cite the above reference if you wish to use this data
DOI of this data:10.5281/zenodo.406785
Measurement of co(n,xp) cross sections by a surrogate method
No full textThe cross sections for Co(n,xp) reactions have been determined in the equivalent neutron energy range of 11.7–16.8 MeV by employing the surrogate reaction ratio method and using the cross-section values for the reference reaction Ni(n,xp) from the literature. The transfer reactions Fe(Li,) at = 37 MeV and Co(Li,) at = 33 MeV, are used to populate compound nuclei Co (surrogate of n+Co) and Ni (surrogate of n+Ni), respectively, at similar excitation energies. The evaporated protons at backward angles measured in coincidence with the projectile-like fragment alpha provide the proton decay probabilities of the compound nuclei. The cross sections estimated using the nuclear-reactions-model code taly
Strain-induced modifications of the band structure of InxGa1-xP–In0.5Al0.5P multiple quantum wells
No full textThe effect of strain on the band structure of InxGa1-xP-In0.5Al0.5P multiple quantum wells (MQW's) has been investigated from high-pressure and low-temperature photoluminescence measurements. The biaxial strain in the wells was varied between +0.6% compressive to -0.85% tensile strain by changing the well composition x from 0.57 to 0.37. Strain increases the valence band offsets in either tensile or compressively strained structures. Whereas relatively insensitive to tensile strain, the valence band offsets showed a strong dependence on the magnitude of the compressive strain. Good agreement is found between the measured valence band offsets and those predicted by the model solid theory, except for the largest compressively strained MQW's, for which the model calculations underestimate the measured valence band offset. Strain and the associated variations in composition also modified the separation among the well states associated with Γ1c, L1c, and X1c. From these results, the bandgaps of each conduction band extrema were calculated in InxGa1-xP for 0.37 < x < 0.57 and compared with the predictions of the model solid theory.This work was supported by the National Science Foundation under Grant DMR 9321422 and Grant ECS-9502888, and by the AFOSR under Contract F49620-93-1-0021
Three angiotensin-converting enzyme inhibitors from Rabdosia coetsa
No full textThe EtOAc extract of Rabdosia coetsa showed angiotensin-converting enzyme (ACE) inhibitory activity. Bioassay-guided isolation of this extract yielded ethyl caffeate (1), rosmarinic acid (2) and methyl rosmarinate (3), which inhibited ACE activity by 32.42%, 55.19% and 39.50% respectively, at the concentration of 10 mu g/ml. (c) 2007 Elsevier GmbH. All rights reserved
3-dimensional transient wave response in a cracked elastic solid
No full textThe three-dimensional transient wave response problem is presented for an infinite elastic medium weakened by a plane crack of infinite length and finite width. Tractions are applied suddenly to the crack, which simulates the case of impact loading. The integral transforms are utilized to reduce the problem to a standard Fredholm integral equation in the Laplace transform variable and sequentially invert the Laplace transforms of the stress components by numerical inversion method. The dynamic mode I stress intensity factors at the crack tip are obtained and some numerical results are presented in graphical form
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