The Constraints on Images of Rectangular Polyhedra

This paper discusses how polyhedron interpretation techniques are simplified if the objects are rectangular trihedral polyhedra. This restriction enables one to compute the spatial orientation of a given corner and its motion from its image in terms of polar coordinates, Eulerian angles, and quaternions. One can also interpret the shape and the face adjacency from local information only. The necessary constraints are listed, and some examples are given to compare the presented scheme to existing ones. The possible nonuniqueness of the interpretation is also discussed.     

The equilibrium oxygen pressure over the Cr-Y2O3-YCrO3 coexistence measured with the galvanic cell using stabilized ZrO2 solid electrolyte

The equilibrium oxygen pressure over the Cr-Y₂O₃-YCrO₃ coexistence has been measured by the following cells: Cr, Y₂O₃, YCrO₃∥ZrO₂∥Cr, Cr₂O₃ [I] Mn, MnO∥ZrO₂∥Cr, Y₂O₃, YCrO₃ [II] Moreover, the partial electronic conduction parameter,P _e, has been determined simultaneously, as the oxygen partial pressure where then-type electronic and ionic conductivities are equal in the stabilized ZrO₂. The equilibrium oxygen pressure,P _{O 2}, over the Cr-Y₂O₃-YCrO₃ coexistence andP _e are expressed as log (P_{O 2}/atm) = 10.6 − 4.39 × 10⁴1/T ± 0.1 (1385 to 1470 K) log ( P_e/atm = 8.86 − 4.21 x 10₄ 1/T ± 0.3 (1385 to 1470 K) From the equilibrium oxygen pressure and the standard Gibbs energy of formation of Y₂O₃, the standard Gibbs energy of formation of YCrO₃ is calculated as ΔG _o ^f /J mol^™1 = −1.58 x 10⁶ + 2.93 x 10² T ± 7 × 10³ (1385 to 1470 K)     

Shock compaction of silicon carbide powder

A series of shock compaction experiments on SiC powder were carried out over a wide range of shock pressures and shock temperatures up to 30 GPa and 3400 K. Large changes in some physical properties and a variety of unique microstructures were observed in the shock-treated samples with changes in impact conditions. For an iron plate impactor, the optimum impact condition, which depends on the initial density, is 2.5 km sec^–1 for 70% initial density and 2.0 km sec^–1 for 50%. The best-sintered compact of SiC with 97% density and micro-Vicker's hardness of 2700 kg mm^–2 was obtained under optimum conditions. Good compacts with high relative density and high strength exhibit the disruptive effects of the shock wave, which are indicated by microstrain increase and crystallite size reduction. The skin model is presented here in order to estimate the heterogeneous shock state which is realized under and after shock loading of the initial powder aggregates.     

Lightwave subscriber loop systems toward broad-band ISDN

The state-of-the-art of lightwave subscriber loop systems is reviewed. An approach is described for deriving an architecture for subscriber loop systems that can accommodate technological trends in broadband ISDN such as asynchronous transfer mode (ATM) and synchronous digital networks. Key component technology is discussed, namely, optical fibers and cables, splicing and connectors, and switching     

Parallel history matching and associated forecast at the center for interactive smart oilfield technologies

We have developed a parallel and distributed computing framework to solve an inverse problem, which involves massive data sets and is of great importance to petroleum industry. A Monte Carlo method, combined with proxies to avoid excessive data processing, is employed to identify reservoir simulation models that best match the oilfield production history. Subsequently, the selected models are used to forecast future productions with uncertainty estimates. The parallelization framework combines: (1) message passing for tightly coupled intra-simulation decomposition; and (2) scheduler/Grid remote procedure calls for model parameter sweeps. A preliminary numerical test has included 3,159 simulations on a 256-processor Intel Xeon cluster at the USC-CACS. The results provide uncertainty estimates of unprecedented precision.     

Simple assay method for endocrine disrupters by in vitro quail embryo culture: nonylphenol acts as a weak estrogen in quail embryos

Many chemicals that are not structurally related to estrogen have estrogen-like activity. In this study, we tried to apply a quail embryo culture system for assessing the in vivo effects of such chemicals on the development of quail embryos. Beta-estradiol induced feminization of the gonads of genetically male embryos, which was confirmed by the increase in the size of the left gonad and female-specific aromatase expression, while male-specific SOX9 expression was not affected. Nonylphenol, which has a weak estrogenic activity, reduced the viability and body weight of embryos. Simultaneously, several genetically male embryos were feminized in terms of gonadal size and aromatase expression. These results indicate that the avian embryo culture system was useful for evaluating endocrine disrupters.