Comparison of responses of CR-39, PM-355, and CN track detectors to energetic hydrogen-, helium-, nitrogen-, and oxygen-ions

Samples made of the CR-39 and PM-355 plastic nuclear track detectors (NTDs) as well as of the CN films were irradiated with quasi-monoenergetic beams of protons, alphas, N⁺-, and O⁺-ions produced by various accelerators. For different samples an energy value of the particle beams was changed from several hundreds keV to 3 or 4.5 MeV. After irradiation the detector samples were etched chemically under controlled conditions during periods lasting from 2 hrs to 20 hrs. Every 2 hrs track diameters were measured by means of an optical microscope. Differences in the crater diameters in the detectors etched in steps, and those etched continously, have been found to be smaller than 10 percent. The paper results detailed calibration diagrams showing a dependence of track diameters on the ion energy value for different etching times.     

Structural studies of metal complexes containing amide ligands

Complexes of Mn(II), Fe(II), Co(II), Ni(II), Cu(II) and Pd(II) with di-N-phenyl pyromellitic diimide (PhPMDI) and di-N-pyridyl pyromellitic diimide (PyPMDI) were prepared and characterized based on analytical, molar conductance, magnetic, IR, PMR, electronic and ESR data. Based on analytical and molar conductance, the complexes have been formulated as [M(PhPMDA)(H₂O)₂]_n (M = Mn, Fe, Co, Ni), [Cu(PhPMDA)]_n [Pd₂(PhPMDA)Cl₂(H₂O)₂], [M(PyPMDA)]_n (M = Mn, Fe, Co, Ni and Cu) and [Pd₂(PyPMDA)Cl₂] In all these complexes PhPMDA acts as a mononegative bidentate ligand whereas PyPMDA acts as a mononegative tridentate one in the form of amide rather than imide. The geometries of the complexes have been proposed based on the electronic spectra. The various bonding parameters have been calculated from the ESR spectra of Cu(II) complexes.     

Enantiomeric separation of halocarboxylic acids by capillary gas chromatography

The direct determination of the enantiomeric purity of halocarboxylic acids is described. The method used involves gas chromatographic separation of the corresponding tert-butylamides on deactivated glass or fused-silica capillaries coated with Chirasil-Val. Both the influence of the amide moiety on enantiomeric resolution and tailing, and the racemization during formation of the amide derivatives were studied.     

Review of brookhaven nuclear transparency measurements (p,2p) reactions at largeQ 2

In this contribution we summarize the results of two experiments to measure the transparency of nuclei in the (p,2p) quasi-elastic scattering process near 90‡ in thepp center-of-mass. The incident momenta went from 6 to 14.4 GeV/c, corresponding to 4.8 <Q ² < 127 (GeV/c)². First, we describe the measurements with the newer experiment, E850, which has more complete kinematic definition of quasi-elastic events. E850 covers a larger range of incident momenta, and thus provides more information regarding the nature of the unexpected fall in the transparency above 9 GeV/c. Second, we review the techniques used in an earlier experiment, E834, and show that the two experiments are consistent for the carbon data. We use the transparencies measured in the five nuclei from Li to Pb to set limits on the rate of expansion for protons involved in quasi-elastic scattering at large momentum transfer.     

From isocyanides to trichloropyruvamides: application to a new preparation of oxamide derivatives

Isocyanides react readily with trichloroacetic acid anhydride forming stable hydrates of trichloropyruvamides. These compounds are valuable intermediates for obtaining oxamides by reaction with TMSCl/NEt₃ followed by addition of an amine.     

Synthesis of trisubstituted 1,3-oxazin-6-ones via base-catalyzed ring-opening annulation of cyclopropenones with N-(pivaloyloxy)amides

The base-catalyzed [3+3]-type annulation between cyclopropenones and N-(pivaloyloxy)amides is reported. The formal insertion of a 1,3-N,O-dipole into a cyclopropenone CC bond yields a six-membered azalactone structure. In the presence of catalytic K₂CO₃ at 60?°C in THF, the disubstituted cyclopropenone couples with benzamides, acrylamides, and a phenylacetamide to produce 2,4,5-trisubstituted 1,3-oxazin-6-ones in 23–99% yield.     

Efficient CO2/N2 separation by mixed matrix membrane with amide functionalized porous coordination polymer filler

A new Pebax-based mixed matrix membrane with amide functionalized PCP filler shows promising CO₂/N₂ separation at ambient temperature.     

Protonic and Oxygen Conduction of Perovskites ATi0.95M0.05O3 - α (A = Ca,Sr, Ba; M = Mg,Sc) in Humid Air

Measurements of the total conduction (450-1030°C) and transport numbers for ions and protons (450-850°C) of titanates ATi_0.95M_0.05O_{3 -} (A = Ca, Sr, Ba; M = Mg, Sc) in humid air are performed. Partial conductions (ionic, protonic, oxygen, hole) and their effective energies of activation are determined. The results are discussed within a model of separate transport of proton and oxygen ion.