Low-attenuation properties of corrugated rectangular waveguide

The attenuation coefficient of a corrugated rectangular waveguide is determined by the power-loss method, using approximations previously found to be successful. An error in earlier predictions by other workers is corrected, and the region identified in which the corrugated waveguide exhibits an attenuation advantage over comparable smooth-wall rectangular waveguide. However, the comparable circular corrugated waveguide is shown to be superior.     

Longitudinal coupling between elements in a disc-on-rod antenna array

A general expression is proposed for the coupling of surface wave antennas based on the equivalence principle and on the reciprocity theorem. A particular application is presented for disc-on-rod antennas, and the coupling coefficient is evaluated as a function of frequency, the array parameters and the element parameters. A physical explanation of the results is suggested.     

Compact antenna range at 35 GHz

The feasibility of operating a compact antenna test range at 35 GHz has been demonstrated. A compact range of simple construction has been shown to have a performance only slightly inferior to the performance at X-band. Diffracted rays from the edges of the source reflector can degrate the purity of the electric field. This has been investigated and sucessfully controlled by serrating the rim of the reflector.     

Compression Heating and Cooling in Elastohydrodynamic Contacts

In this study, the infrared temperature mapping technique, originally developed by Sanborn and Winer (Trans ASME J Tribol 93:262–271, 1971) and extended by Spikes et al. (Tribol Lett 17(3):593–605, 2004), has been made more sensitive and used to study the temperature rise of elastohydrodynamic contacts in pure rolling. Under such conditions lubricant shear heating within the contact is considered negligible and this allows temperature changes due to lubricant compression to be investigated. Pure rolling surface temperature distributions have been obtained for contacts lubricated with a range of lubricants, included a group I, and group II mineral oil, a polyalphaolefin (group IV), the traction fluid Santotrac 50 and 5P4E, a five-ring polyphenyl-ether. Resulting maps show the temperature rise in the contact increases in the inlet due to compression heating and then decreases and in most cases becomes negative in the exit region due to the effect of decompression. Temperature changes increase with entrainment speed but in the current tests are always very small, and less than 1 °C. Contact temperature rises from compression were compared to those from sliding contacts (where a slide-roll ratio of 0.5 was applied). Here the contribution to the contact temperature from compression is shown to decrease dramatically with entrainment speed. The lubricant 5P4E is found to behave differently from other lubricants tested in that it showed a peak in temperature at the outlet. This effect becomes more pronounced with increasing speed, and has tentatively been attributed to a phase change in the exit region. Using moving heat source theory, the measured temperature distributions have been converted to maps showing rate of heat input into each surface and the latter compared with theory. Qualitative agreement between theory and experiment is found, and a more accurate theoretical comparison is the subject of ongoing study.     

The long-term prediction of offender recidivism using diagnostic, personality, and risk/need approaches to offender assessment.

The present study examined the prediction of recidivism using diagnostic, personality, and risk/need approaches over a 10-year follow-up in a heterogeneous sample of 61 offenders (i.e., probationers and provincial and federal offenders). The Level of Service/Case Management Inventory (LS/CMI), Psychopathy Checklist-Revised (PCL-R), and DSM-III antisocial personality disorder (APD) were examined. The measures were highly correlated and demonstrated theoretically meaningful patterns of convergent validity. Although psychopathy was highly correlated with both LS/CMI and APD, the majority of the shared variance with LS/CMI and with APD was accounted for by Factor 2 and the criminality facet of the PCL-R. All three assessment measures predicted future violence, any future reincarceration upon release, and recidivism severity (as measured by aggregate sentence length). However, none of these measures made a significant incremental contribution to the prediction of recidivism beyond either of the other two measures. Differences between the predictive validities of the three measures were minimal. The results are discussed in terms of recent debates concerning the use of these instruments in the assessment of offender risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low-attenuation characteristics of dielectric-lined waveguide

A low-attenuation characteristic of the EH11 mode in dielectric-lined circular waveguide is explained in a manner similar to that reported by Carlin and D'Agostino for TM0m modes. It is shown that the longitudinal magnetic field of the hybrid mode has a low intensity at the wall in the regime of low attenuation.     

Radiation patterns of pyramidal dielectric waveguides

The radiation patterns of pyramidal dielectric waveguides excited by pyramidal metallic horns are predicted and compared with patterns measured at 9 GHz. Satisfactory agreement is obtained, especially in the region of the main beam. At wide angles, the pattern corresponds quite closely to that of the launcher alone.     

An open multicentre study of tropisetron for cisplatin-induced nausea and vomiting

1. P2X-receptors are ligand-gated ion channels which activate within milliseconds of agonist binding, causing rapid cellular depolarization and excitation. This makes them ideally suited to mediate the rapid neurotransmitter functions of adenosine 5'-triphosphate (ATP). 2. The initial postjunctional response of the vas deferens and most blood vessels to sympathetic nerve stimulation is a rapid, transient excitatory junction potential (EJP). With sufficient stimulation EJPs summate and the membrane depolarizes sufficiently to open voltage-dependent calcium channels, initiating a calcium action potential and contraction. 3. EJPs are inhibited by desensitization of the P2X-receptor by the stable agonist alpha, beta-methyleneATP (alpha, beta-meATP) and by the P2X-receptor antagonists ANAPP3, suramin and pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid, indicating that they are consequent upon activation of the P2X-receptor. 4. The P2X-receptor was originally defined by contractile studies in smooth muscle preparations, where a rank order of agonist potency of alpha, beta-meATP > > 2-methylthioATP (2-meSATP) > or = ATP was found. However, recent results show that the potency of ATP and 2-meSATP, but not alpha, beta-meATP, is decreased by 100-to 1000-fold by breakdown and when this is prevented, ATP and 2-meSATP are more potent than alpha, beta-meATP as agonists at the P2X-receptor. 5. This conclusion was supported by the cloning and functional expression of the P2X1-receptor from the rat bladder. A total of seven P2X-subunits have since been cloned and the P2X1-subunit is thought to be the predominant subunit expressed in vascular smooth muscle cells.     

Differential and Numerically Invariant Signature Curves Applied to Object Recognition

We introduce a new paradigm, the differential invariant signature curve or manifold, for the invariant recognition of visual objects. A general theorem of É. Cartan implies that two curves are related by a group transformation if and only if their signature curves are identical. The important examples of the Euclidean and equi-affine groups are discussed in detail. Secondly, we show how a new approach to the numerical approximation of differential invariants, based on suitable combination of joint invariants of the underlying group action, allows one to numerically compute differential invariant signatures in a fully group-invariant manner. Applications to a variety of fundamental issues in vision, including detection of symmetries, visual tracking, and reconstruction of occlusions, are discussed.