H*(10) and neutron spectra around linacs

Neutron spectrum and ambient dose equivalent has been measured around two 10 MV linear accelerators. Measurements were carried out in Mevatron and Primus model linacs, both made by Siemens. Main differences between those models are the beam collimator and the vault room. Here, Bonner sphere spectrometer with a passive thermal neutron detector has been utilized to measure the neutron spectrum inside the vault. Using an active detector the neutron spectrum was measured at the vault’s door of both accelerators. With a neutron area monitor the dose equivalent was measured by the door at both vault doors. Neutron strength, total fluence rate and ambient dose equivalent were compared, from this was found that shielding conditions are better in the Primus model.     

cis/trans Isomerism of Hydroalumination and Hydrogallation Products—Reflections on Stability and Rearrangement Mechanism

Treatment of (silylalkynyl)benzenes with (Me₃C)₂Ga? H afforded stable cis‐addition products, for example, (Me₃C)₂Ga? C(SiMe₃)?C(H)? C₆H₅ ( 1 ), while spontaneous cis/trans rearrangement was observed for sterically less shielded gallium hydrides. The corresponding trans‐di(tert‐butyl)gallium compounds ( 13 , 14 ) were obtained by the reaction of C₆H_6?n[C(H)?C(SiMe₃)GaCl₂]_n ( 11 , 12 ) with LiCMe₃. In contrast, spontaneous isomerization took place upon reaction of (Me₃C)₂Al? H with phenyltrimethylsilylethyne. In this case the cis isomer ( 17 ) was detected only at low temperature, while the trans product ( 18 ) formed quantitatively above 0 °C. Quantum‐chemical calculations showed that the trans forms are thermodynamically favored, essentially caused by a better mesomeric interaction of the C?C double bonds with the phenyl groups, a smaller steric stress in the molecules, and a short bonding contact of the coordinatively unsaturated Al or Ga atoms to C? H bonds of the aromatic rings. The rotation about the C?C double bonds follows a zwitterionic mechanism, and the relatively small rotational barrier is further lowered by an interaction to a Lewis acidic lithium cation.     

Numerical solution of the St. Venant equations with the MacCormack finite-difference scheme

This paper describes the use of the MacCormack explicit time-spilitting scheme in the development of a two-dimensional (in plan) hydraulic simulation model that solves the St. Venant equations. Various tests devised to assess the performance of the method have been performed and the results are reported. Finally, two industrial applications of the model are presented. The method has been found to be computationally efficient and warrants further development.     

Transverse Polarization of Λ hyperons in relativistic Au−Au collisions at the AGS

We investigate the transverse polarization of A hyperons produced in 11.6 A GeV/c Au?Au collisions at the AGS. Experiment E896 yields results in two independent detector systems, a Silicon Drift Detector Array at midrapidity and a Distributed Drift Chamber at forward rapidity. In this article we focus on the mid-rapidity measurements. The results reveal a dependence of the polarization on the transverse momentum and Feynman-x of the A hyperons. The heavy-ion data are consistent with previous measurements in proton-proton and proton-nucleus collisions within statistical errors.     

Espaces metriques constitutes de classes de polytopes convexes lies aux problemes decomposition

We introduce in the space of translation classes of polytopes a metric which is related to the Minkowski decomposition of polytopes. In this metric space the connected components of topological dimension one are shown to coincide with the translation classes of indecomposable polytopes.     

Optimal Compensation Plans for Salesmen Who Trade-off Leisure Time Against Income

This paper discusses the minimum requirements for an adequate salesmen's compensation plan structure to lead to profit maximization by inducing non-income maximizing salesmen (1) to deploy the highest profitable activity level, and (2) to optimally allocate their time among various selling activities. It is found that a commission-quota-bonus plan is such a structure. These results hold under a large set of plausible behavioral patterns of salesmen's responses to financial incentives. In addition, the analysis supports the use of challenging sales quotas for improved sales force efficiency.     

Structure in excimer line shape

Recently monomer-like structured emission has been observed in the spectra of excimers both in solids and in solution. In a two-dimensional model potential an intramolecular mode is considered in addition to the relative degree of freedom. It is shown that under certain conditions structured line shapes are obtained.