Ring fragmentation processes resulting from acid catalysed diazo ketone cyclisations

The initial products from the cyclisation of hexahydrophenanthryl diazo ketones with participation by either the alkene bonds or the aromatic ring (Ar_1,4) undergo rearrangement by 1,2 bond shifts or unexpected bond fission. Benzocyclo-octanyl ketones were formed from the latter process.     

Cost of power—the user's perspective

With the advent of fiber in the loop, transmission of power ceases to be through the traditional communications medium, and the objective of powering voice lines over fiber with the same reliability goals as plain old telephone service (POTS) raises several technological, regulatory, and business issues. In order to power the optical network unit (ONU) and provide backup power for it during commercial power outages, three strategies are identified: 1) providing loop powering from a -48 volt CO/CEV power plant; 2) providing power and backup power locally, from or near the end of the loop in proximity to the OW; and 3) providing power from the curb or a power node. This paper constructs economic models to determine the worth of a watt at the 5-volt logic level at an ONU for each of the powering strategies. By normalizing all costs to the worth of a watt, comparisons can be made and appropriate architectures can be selected for various applications.     

Freeze-out conditions in ultrarelativistic heavy-ion collisions

We present recent results on single particle transverse momentum distributions of pions, kaons and protons, measured in CERN Experiment NA44, of 200 AGeV/c S+S and 158 AGeV/c Pb+Pb central collisions. By comparing these data with thermal and transport models, freeze-out parameters like the temperatureT _fo and the chemical potentials (μ _q ,μ _s ) are extracted and discussed.     

Specific heat and electrical resistivity of CeCu6 below 1 k

Results of measurements of the electrical resistivity ? between 0.04 and 1 K and the specific heat c_p between 0.06 and 1 K of annealed polycrystalline CeCu₆ are reported. ? varies proportional to T² below 0.1 K but is linear in T above 0.6 K. The specific heat is proportional to T below 0.5 K and the electronic specific-heat parameter $\text{γ = 1.53}\text{J}\text{mole}\text{K}{}^2$.     

A measurement of direct photon production at large pT at the CERN ISR

We have measured direct photon production in pp collisions at the CERN intersecting storage rings for c.m. energies 31 < √s < 63 GeV and transverse momenta up to 9GeV/c, using segmented lead/liquid-argon calorimeters. The ratio of direct photon to π⁰ production is significantly larger than zero, starting at p_T ≈ 4 GeV/c and increasing to values of about 0.4 at 9GeV/c. No significant √s dependence is seen.