Calculation of orientation factors for crystalline polymers from X-ray pole figure intensities

Summary The characterization of polymer orientation is discussed by expanding the orientation distribution function (ODF) for the crystalline phase into a series of generalized spherical harmonics (GSH) or into a series of symmetric generalized spherical harmonics (SGSH). A transformation relation is derived between the two expansions. By means of this transformation the orientation factors (moments of the ODF) can be calculated from the SGSH series expansion coefficients. As an example, this transformation is demonstrated for crystals of hexagonal symmetry and fiber texture.     

CMOS analog front end of a transceiver with digital echocancellation for ISDN

A CMOS analog front-end which contains a novel pulse-shaping circuit, an extremely linear-line-driver state, an oversampling second-order noise-shaping coder, and a wake-up signal detector is discussed. An analog front-end for 4B 3T coded signals is realized in a 2.5-μm CMOS technology and operates up to 4.5 km with 0.4-mm-diameter lines, needing only one 5-V power supply. It is possible to transmit 2B 1Q coded signals also, using a modified pulse-shaping circuit     

Pharmacokinetics of the PDGF-antagonist trapidil in patients with and without renal impairment

BACKGROUND: From July 1989 to February 1996, 130 patients underwent stereotactic radiosurgery. We report the results of the first 50 patients eligible for a minimum of three years of follow-up. METHODS: Twenty women and 30 men, (mean age: 37.5 years) were treated by dynamic rotation on a 6 MV linear accelerator. Prior treatment was embolization in seventeen, surgery in three and embolization and surgery in six. All had DSA and enhanced CT scanning, while some had MRI. Forty-seven treatments used a single isodose. Restricting eloquent normal tissue to 15 Gy, margin doses (at 50-90% isodose) were 12 Gy (one patient); 15 Gy (sixteen patients); 20 Gy (31 patients); 25 Gy (two patients). Maximum diameters were: < 1.5 cm (12 patients); < 2.0 cm (nine patients); < 2.5 cm (twelve patients); < 3.0 cm (thirteen patients; 3.0 cm (four patients). RESULTS: Forty-five patients were evaluable at three years, with thirty-nine having angiography. Twenty-five had angiographically confirmed obliterations; two had parenchymal AVMs obliterated but with residual dural components; four had MRI evidence of obliteration (refused angiography). One patient acutely had a seizure; one patient (with hemorrhages, resection, and embolizations preceding two applications of radiosurgery, separated by 3.5 years) had worsening of memory. CONCLUSIONS: Our uncorrected (five patients unevaluable at three years) and corrected angiographically confirmed obliteration rates are 54% and 60% respectively. Our follow-up (98% accounting of cohort; 78% angiographic rate) and explicit derivation of denominators help delineate the efficacy of radiosurgery at these doses.     

The prevalence and implications of ocular hypertension and glaucoma in thyroid-associated orbitopathy

Experiments are carried out on 3400 mice, irradiated in dose 8 Gy (LD97/30). beta-Ketoanalogs of adrenaline (adrenalone, 50-150 mumol/kg), m,p-dipivaloyladrenaline (20 mumol/kg) and phenylephrine (but at 2070 mumol/kg) have the high radioprotective effect (survival is 60-100%), beta-ketoanalogs of isoprenaline and m-benzoylphenylephrine have the middle RPE (50-60%). Their effective doses (except dipivaloyladrenalone) are considerably bigger (in 9-76 times), than beta-hydroxysubstances doses, but the toxicity of benzoylphenylephrone, dipivaloyladrenalone and especially adrenalone is by far lower (consequently in 3, 8, 2, 7 and 136 times). Therapeutic indexes of beta-ketosubstances achieve 35-100.     

Fodel microresistors––processing and basic electrical properties

The dimensions of discrete passives, passive integrated components (arrays, networks) and embedded integral ones should be significantly reduced in the nearest future. For example, passive components with 01005 package size will be commercially available in 2010. This means that the effective length of resistor in/on such package should be approximately two times smaller than the package length. This paper presents fabrication and preliminary electrical characterisation of Fodel microresistors fabricated from EP E-93350-153 (1 kΩ/□) photopatternable resistor ink and Ag-based DP 6453 Fodel conductors. Two versions of microresistors––screen-printed and made in full Fodel process––were made and compared. The effective resistor dimensions varied from 50×50 to 800×200 μm². The processing achievements and problems are presented and discussed. The relation between designed and fabricated patterns is compared for both technological versions. The sheet resistance, hot temperature coefficient of resistance and long-term stability at elevated temperature are characterised as a function of resistor geometry and related to length and width of microresistors. Also normalised temperature dependencies of resistance in a wide temperature range (between −170 and 130 °C) are presented and analysed.     

Fish passes design discharge requirements for successful operation

Longitudinal connectivity is one of the prime issues addressed in river restoration our days. At the same time, mitigation of climate change impacts by modes of renewable energy increasingly puts pressure on the remaining free flowing river stretches for hydroelectricity production. At the site level, this trade‐off manifests in the negotiation of water for upstream and downstream fish passage versus losses for hydroelectricity production. This study has compiled and analysed 193 studies evaluating fish passes designed to provide upstream migration for all species and size classes of the respective river system. The overall assessment of functioning and discharge dedicated to fish pass maintenance, site, and river characters were provided by the studies. The main objective here was deriving general guidance for the minimum amount of water needed for fully functioning upstream fish passage in relation to river size. There was a significant correlation between functionality and design discharge of a fish pass. Fully functioning fish passes (N = 92) had median design discharge of 5% of the mean average discharge of the river, restrictedly functioning of 1.1% and not functioning of 0.22%. A power model could be derived of design discharge needs in relation to river discharge, which is inversely related to river size. In large rivers, a rather small share of mean discharge is sufficient, whereas in small rivers, it cannot be further downscaled due to dimensions. This model might provide first guidance in adjusting needs for both hydroelectricity generation and fish conservation in regulated rivers.     

Synthesis and characterization of a water-soluble rigid-rod polymer

Water-soluble polyaramides have been prepared from 2,5-diaminobenzene-sulphonic-acid activated by TMSCl and terephthalic-acid-chloride. Using this method, we achieved molecular weights of our polymers up to 18,000 g mol⁻¹. Two model compounds were synthesized in order to establish the effect of trimethylsilyl-chloride, which was used as the activating agent for this reaction. The resulting sulphonated poly-aramides were characterized by: inherent viscosity measurements, size exclusion chromatography (SEC), DMA, TGA, flame absorbance atomic spectroscopy (FAAS), NMR spectroscopy and optical polarisation microscopy. In all cases, the polymers were easily soluble in hot water up to concentrations of 20 wt%. Upon cooling lyotropic alignment of molecular aggregates is observed at low polymer concentrations, typically 2–5 wt%. Polymers with low molecular weights do not show this behaviour. Films made from these sulphonated aramide polymers showed good thermal stability, and have interesting mechanical properties. Our results indicate the presence of a structure consisting of molecular aggregates.     

Laboratory evaluation of plastic pipe from a gas service field-test installation

This article presents the background and results of the first two-year interval test of a projected 10 or more years field gas service test of various types of plastic pipes. The study is part of a program to establish the suitability of plastic pipes for gas distribution uses. A number of short-term laboratory tests were used to characterize the condition of the pipe after the first two-year exposure period some, like the cursh test, are recognized and accepted methods; others, like the ring-tensile, tensile-impact, and the tear-propagation tests were developed or modified for this stdy. The results show that comparatively little change had taken place in this test period; the possible exception being in the ductility of two kinds of pipe subsequent evaluation should confirm or deny this behavior.