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Experiences with the narrow gap undulator at MAX-lab

An undulator with short poles (period 24 mm) and extremely narrow gap (magnet gap 7.7 mm) using a squeezable vacuum chamber has been installed and is in operation at the MAX-lab 550 MeV storage ring. The device operates with a vacuum chamber aperture down to 6.2 mm. The behaviour of the storage ring concerning lifetime, emittance, tune shift and closed orbit is well described by conventional model

Positron production for ESRF

In this report, we first discuss some different pre-injector possibilities for the ESRF booster synchrotron, using estimated machine performances. We then focus on the commercially available linac schemes carrying out more detailed calculations. We also look into the possibility of recyling the particles through the linacs.

On the Gilbert-Varshamov distance of abelian group codes

The problem of the minimum Bhattacharyya distance of group codes over symmetric channels is addressed. Ensembles of ℤm-linear codes are introduced and their typical minimum distance characterized in terms of the Gilbert-Varshamov distances associated to the subgroups of ℤm. For the AWGN channel with 8-PSK as input it is shown that the typical ℤ8 -linear code achieves the Gilbert-Varshamov bound.

TMEM106B and ApoE polymorphisms in CHMP2B-mediated frontotemporal dementia (FTD-3)

Single-nucleotide polymorphisms in the TMEM106B gene have been identified as a risk factor in frontotemporal dementia (FTD). The major allele of SNP rs3173615 is a risk factor in sporadic FTD, whereas the minor allele seems protective in GRN- and C9orf72-mediated FTD. The role of apolipoprotein E (ApoE) in FTD is uncertain, though an established risk factor in Alzheimer's disease. In a unique Dani

Visual fields at different stages of diabetic retinopathy

Available studies on visual field disturbances in diabetic retinopathy have shown conflicting results, obtained with different and often non-comparable techniques. We have studied visual fields at different stages of diabetic retinopathy with modern sensitive computerized technique taking precautions to limit disturbing effects of random field variation and lack of perimetric experience. Sixty-thr

A clinical study of perimetric probability maps

Perimetric probability maps depict visual field results in terms of the frequency with which the measured findings are seen in a normal population. We tested clinically the importance of the model of the normal visual field used to calculate such maps. Forty-one eyes of 41 normal subjects and 58 eyes of 46 glaucomatous patients were studied. Probability maps were calculated by means of two differe

Resolving the heading-direction ambiguity in vertical-beam radar observations of migrating insects

Each year, massive numbers of insects fly across the continents at heights of hundreds of meters, carried by the wind, bringing both environmental benefits and serious economic and social costs. To investigate the insects' flight behavior and their response to winds, entomological radar has proved to be a particularly valuable tool; however, its observations of insect orientation are ambiguous wit

Requirements and potential for high performance cutting tools based on superhard phases in new applications

This work covers qualitative and quantitative requirements with regard to material propertiesfor cutting tools to be able to resist and balance the various interactive mechanisms that causethe wear of the cutting edge and put limits its tool life. In metal cutting, tool life T combinedwith the cutting data (cutting speed, feed and depth of cut) controls largely the manufacturingcost and related co