Double folding model analysis of 7Li scattering

Elastic scattering angular distributions have been measured for the scattering of ⁷Li by ⁴⁴Ca, ⁵⁶Fe and ^{58, 60}Ni at $\text{E(}{}^7\text{Li}\text{) = 34}\text{MeV}$. These data are well described by the optical model using volume Woods-Saxon potentials. These and previously measured ⁷Li scattering data also have been analyzed with a double-folding real potential which employs the nucleon-nucleon potential of Bertsch et al. The overall best fit to the experimental data down to σ/σ_R ~ 10^?3 is obtained when the DF potential is multiplied by approximately 0.6. However, the best fit for the peripheral data alone (σ/σ_R ～ 10^?1 is obtained without any renonnalization.     

The Maximum Number of Complete Subgraphs of Fixed Size in a Graph with Given Maximum Degree

In this article, we make progress on a question related to one of Galvin that has attracted substantial attention recently. The question is that of determining among all graphs G with n vertices and , which has the most complete subgraphs of size t, for . The conjectured extremal graph is , where with . Gan et al. (Combin Probab Comput 24(3) (2015), 521–527) proved the conjecture when , and also reduced the general conjecture to the case . We prove the conjecture for and also establish a weaker form of the conjecture for all r.     

Space-charge effects in liquid metal ion sources of different geometries

The current work considers the effect of geometry, other than the ideal Taylor cone, on space charge and axial fields of liquid metal ion sources. Solutions of the spacecharge equation for the concentric sphere and hyperboloidal-planar models of a liquid emitter demonstrate a rather dramatic dependence of the space charge and axial fields on the geometry of the emitting surface.This research was supported in part by the NATO Research Grants Division, Grant No. 1902, Scientific Affairs Division, Brussels, BelgiumAltoona Campus     

Arabidopsis P-glycoprotein19 participates in the inhibition of gravitropism by gravacin

ATP-binding cassette (ABC) transporters have been implicated in a multitude of biological pathways. In plants, some ABC transporters are involved in the polar transport of the plant hormone auxin and the gravitropic response. We previously identified Gravacin as a potent inhibitor of gravitropism in Arabidopsis thaliana. We demonstrate that P-glycoprotein19 (PGP19) is a target for Gravacin and participates in its inhibition of gravitropism. Gravacin inhibited the auxin transport activity of PGP19 and PGP19-PIN complexes. Furthermore, we identified E1174 as an important residue for PGP19 activity and its ability to form active transport complexes with PIN1. Gravacin is an auxin transport inhibitor that inhibits PGPs, particularly PGP19, which can be used to further dissect the role of PGP19 without the inhibition of other auxin transporters, namely PIN proteins.     

One-step multiple component isolation from the oil of Crinitaria tatarica (Less.) Sojak by preparative capillary gas chromatography with characterization by spectroscopic and spectrometric techniques and evaluation of biological activity

Gas chromatographic analysis revealed that the oil of Crinitaria tatarica was rich in sabinene (32.1%), β-pinene (8.8%), and two unknown (M+200) compounds (I) and (II) (21.4% and 3.4%). One-step multiple fractionation of the oil and separation of two unknown constituents were performed using preparative capillary gas chromatography connected to preparative fraction collector system. This combination allowed separation and recover of sufficient quantities of two unknown compounds with high purity from complex oil matrix. Separation conditions (column temperature, cooling temperature, flow rate, injection volume, cut time) were optimized to achieve the best isolation and successful collection. The target compounds were separated from the oil using a HP Innowax (Walt & Jennings Scientific, Wilmington, DE, USA) preparative capillary column in rapid one-step manner with 95.0% purity. Trapping of the isolated compounds in collector system was facilitated by cooling with liquid nitrogen. Structure determination was accomplished by spectral analysis including ultraviolet, nuclear magnetic rezonance, and high-resolution electrospray ionization mass spectrometry. Z- (I) and E-artemidin (II) were isolated for the first time from this species. Crinitaria tatarica oil and Z- (I) and E-artemidin (II) were evaluated for biological activity.     

Synthesis and biological activity of tetralone abscisic acid analogues

Bicyclic analogues of the plant hormone abscisic acid (ABA) were designed to incorporate the structural elements and functional groups of the parent molecule that are required for biological activity. The resulting tetralone analogues were predicted to have enhanced biological activity in plants, in part because oxidized products would not cyclize to forms corresponding to the inactive catabolite phaseic acid. The tetralone analogues were synthesized in seven steps from 1-tetralone and a range of analogues were accessible through a second route starting with 2-methyl-1-naphthol. Tetralone ABA 8 was found to have greater activity than ABA in two bioassays. The absolute configuration of (+)-8 was established by X-ray crystallography of a RAMP hydrazone derivative. The hydroxymethyl compounds 10 and 11, analogues for studying the roles of 8- and 9-hydroxy ABA 3 and 6, were also synthesized and found to be active.     

WIDECARS spectra fitting in a premixed ethylene–air flame

WIDECARS measures temperature and mole fractions of most of the major species in ethylene–air flames. One of the issues in implementing this technique is fitting the experimental spectra to theory to obtain flame conditions (temperature, species mole fractions). Individual spectra contain many species resonances, and theory is slow to compute. Libraries of precalculated spectra can be used, but a library of sufficient density for accurate interpolation is large given the many variables. A new fitting algorithm is presented which utilizes a less‐dense library, and additional spectra are calculated during fitting to maintain accuracy. The iterative convergence method converts the problem of minimizing fit error, which converges slowly, to a zero finding problem, which converges reliably, rapidly, and accurately to best fit. Various practical fitting issues, such as the effects of dye laser mode noise and variability, phase‐matching efficiency, and shifts of the spectrum on the spectrometer are addressed. The technique is demonstrated in the analysis of experimental measurements in an equivalence ratio 2.1 ethylene–air flame above the surface of a McKenna burner. Precision errors because of experimental and fitting effects are discussed. Copyright © 2015 John Wiley & Sons, Ltd.     

Use of optical fibres in Raman spectroscopy

A detailed study of the parameters governing the design of an optical fibre system for use in Raman spectroscopy is described. The results have led to the design and construction of a flexible fibre optic remote sampling system which is easily adaptable for use on most commercial instruments. A variety of samples were used to evaluate the performance of the system and have been classified in terms of the efficiency of the new technique relative to more conventional methods of excitation and collection.