The g-factors of short-lived isomeric states in 108Ag and 110Ag

Short-lived isomeric states in ¹⁰⁸Ag and ¹¹⁰Ag were populated by means of (p, n) and (d, p) reactions. The nuclear g-factors of these states were determined with the pulsed beam DPAD method to be $\text{g(}{}^{108}\text{Ag}\text{; 215}\text{keV}\text{) = 1.294(6)}\text{and}\text{g(}{}^{110}\text{Ag}\text{; 119}\text{keV}\text{) = 1.277(15)}$. The results indicate a spin and parity I^π = 2⁺ for ¹⁰⁸Ag and I^π = 3⁺ for ¹¹⁰Ag.     

Study of Kπ scattering using the reactions K±p → K±π+nand K±p → K±π−Δ ++at 13 GeV

An elastic Kπ partial-wave analysis is presented. It is based on high statistics data for the reactions $\text{K}{}^{\mathrm{\pm }}\text{p}\text{→}\text{K}{}^{\mathrm{\pm }}\text{π}{}^{\mathrm{+}}\text{n}\text{and K}{}^{\mathrm{\pm }}\text{p}\text{→}\text{K}{}^{\mathrm{\pm }}\text{π}{}^{\mathrm{?}}\text{Δ}{}^{\mathrm{++}}\text{at}\text{13}\text{GeV}$ obtained in a spectrometer experiment performed at SLAC. For each reaction, a t-dependent parametrization of the production amplitudes provides information on both the Kπ mass dependence of the production mechanisms and on Kπ scattering. Knowledge of the t-dependence then allows a calculation of the Kπ partial-wave amplitudes for Kπ masses from 0.7 to 1.9 GeV. The results of such analyses using data for (i) the neutral recoil reactions, (ii) the Δ⁺⁺ recoil reactions, and (iii) both neutron and Δ⁺⁺ recoil reactions simultaneously, are presented. Besides the leading J^P = 1^?, 2⁺, and 3^? resonances at M_Kπ = 0.896, 1.434, and 1.78 GeV, there is evidence in two of the four possible partial-wave solutions for a broad P-wave resonant-like structure in the region of 1700 MeV. The $\text{I =}\text{1}\text{2}$ S-wave magnitude rises slowly and smoothly to a maximum near 1400 MeV, but then decreases rapidly between 1400 and 1600 MeV. This structure is strongly indicative of an S-wave resonance near 1450 MeV. The charge-two Kπ reaction is dominated by S-wave scattering with a total cross section decreasing from 4 mb at 0.9 GeV to 2 mb at 1.5 GeV. Both the $\text{I =}\text{1}\text{2}$ S-wave below 1400 MeV and the $\text{I =}\text{3}\text{2}$ S-wave are well described by an effective range parametrization.     

Legendre Curves and the Singularities of Ruled Surfaces Obtained by Using Rotation Minimizing Frame

Ukrainian Mathematical Journal - We represent Legendre curves in unit tangent bundle by using rotation minimizing vector fields. Ruled surfaces corresponding to these curves are specified. The...     

Reveromycins revealed: new polyketide spiroketals from Australian marine-derived and terrestrial Streptomyces spp. A case of natural products vs. artifacts

Chemical analysis of fermentation products from two Australian Streptomyces isolates yielded all four known and twelve new examples of the rare reveromycin class of polyketide spiroketals, including hemi-succinates, hemi-fumarates and hemi-furanoates. Reveromycins were identified with the aid of HPLC-DAD-MS and HPLC-DAD-SPE-NMR methodology, and structures were assigned by detailed spectroscopic analysis. The structural and mechanistic requirements for an unprecedented hemi-succinate?:?ketal-succinyl equilibrium were defined and provided a basis for proposing that reveromycin 4'-methyl esters and 5,6-spiroketals were artifacts. A plausible reveromycin polyketide biosynthesis is proposed, requiring a 2-methylsuccinyl-CoA starter unit, with flexible incorporation of a C(6-8) polyketide chain extension and diacid esterification units. Structure activity relationship investigations by co-metabolites were used to assess the anticancer, antibacterial and antifungal properties of reveromycins.     

Analysis of K−K+ and π−π+ final states in 13 GeV K−p interactions

The differential cross sections and density matrix elements for the φ and ?⁰ mesons have been measured in the reactions K^?p → K^?K⁺ (Λ, Σ⁰) and K^?p → π^?π⁺ (Λ, Σ⁰) at 13 GeV using a wire chamber spectrometer. The analysis shows that while the vector meson production is dominated by the natural parity exchange amplitude, some unnatural parity exchange is also required. Furthermore the φ and ? natural exchange cross sections are identical in shape and have the 2:1 relative strength expected in the quark model with K¹ and K⁷ exchange degeneracy. The analysis of the clear peak-dip ?^0?ω interference pattern observed in the π^?π⁺ data indicates that the ω production is in phase with the ? and of similar magnitude. Both the S¹ and f′ meson are clearly observed in this experiment. The S¹ data are found to be consistent with S¹ parameters deduced from ππ scattering analyses. The f′ density matrix elements and a new limit of the f′ → π^?π⁺ branching ratio are presented.     

Determination of the K(1800) spin parity

A spherical harmonic moment analysis of the reactions K⁻p → K⁻π⁺n and K⁺p → K⁺π⁻Δ⁺⁺ at 13 GeV/c demonstrates the existence of a broad K^* state with mass in the vicinity of 1800 MeV and spin parity 3⁻.     

High resolution Ne-Auger spectrum produced in 4.2 MeV H+-Ne collisions

Auger electrons resulting from 4.2 MeV proton impact on Ne were measured by 1.2 eV spectroscopic resolution. The proton-induced Auger spectrum was found to be identical to the spectra previously observed by electron and photon bombardment.     

An image deblurring method using diffraction gratings

A method of image deblurring is described, in which the restoration filter is derived from Ronchi rulings. Although two-dimensional spatial filtering is used, the method employs a line source, resulting in significant noise reduction. Experimental results are given.