Gearless Drive for a Finish-Grind Mill with a Capacity of 160 t/h

The principle of the gearless drive has already been applied to some large mills. A synchronous motor is ``wrapped' directly around the mill cylinder and supplied by a thyristor frequency converter at approximately 10-percent system frequency. The drive thus operates at the low mill speed and dispenses with interposed gearing.     

DNA damage by PAH and repair in a marine sponge

The sponge Tethya lyncurium from the Northern Adriatic has been used as an experimental species.A method is outlined for preparation of DNA which yields a highly purified DNA with a double-strand (ds) molecular weight of 25 M-dalton between single-strand (ss) breaks, which when properly damaged can be cut opposite to ss-breaks with nuclease s₁. The molecular weights of the resulting ds-DNA pieces and their distribution has been evaluated by electron microscope photographs.Sponges exposed to benzo[a]pyrene (BaP) in the dark only incorporate BaP-derivatives (BaPD) in small amounts, if any. However, in the presence of light, derivatization to BaP derivatives enables effective coupling to occur, as shown previously (R. K. Zahn et al., 1981). Sponges were exposed to radiolabeled BaP in the presence of light. Coupling of BaPD to the DNA as well as the induction of ss-breaks were measured.Light-mediated coupling is concentration dependent from 0.01 – 20 ppb BaP with a correlation coefficient of r = 0.84.Under conditions of possible repair, ss-breaks completely disappear from sponge DNA in the course of three weeks while a substantial fraction of the BaP derivatives persists.Double label experiments show that substantial DNA synthesis occurs during this time. Pollution causes a decrease of the molecular weight of unnicked DNA, re-incubation in clean water an increase. A DNA species of 24 M-dalton seems to play a critical role. If its percentage in the DNA population drops below a critical level, recovery is not longer possible. DNA damage by PAH and repair in sponges seems to differ from that of most eucaryotes.     

Health and safety precautions in the relining of aluminum electrolysis cells

The risk of accidents when handling liquid metal and bath, the potential for explosions through reactions of gases, and electrical hazards all highlight the vital importance of safety in the cathode repair and cell restart processes. With respect to hygiene, refractory materials and reaction products must be handled carefully when repairing cathodes and when welding. Personnel therefore require appropriate clothing and protective equipment. This article reviews various procedures—short circuiting a cell, digging out the spent potlining, preparing the empty steel shell, fixing the steel bars to the cathode blocks, and general relining and start-up—in the context of both safety and health.     

Spatial Non-Cyclic Geometric Phase in Neutron Interferometry

We present a split-beam neutron interferometric experiment to test the non-cyclic geometric phase tied to the spatial evolution of the system: the subjacent two-dimensional Hilbert space is spanned by the two possible paths in the interferometer and the evolution of the state is controlled by phase shifters and absorbers. A related experiment was reported previously by some of the authors to verify the cyclic spatial geometric phase. The interpretation of this experiment, namely to ascribe a geometric phase to this particular state evolution, has met severe criticism. The extension to non-cyclic evolution manifests the correctness of the interpretation of the previous experiment by means of an explicit calculation of the non-cyclic geometric phase in terms of paths on the Bloch-sphere. The theoretical treatment comprises the cyclic geometric phase as a special case, which is confirmed by experiment.     

Unipolar Depression, Life Context Vulnerabilities, and Drinking to Cope.

This study followed baseline samples of 424 unipolar depressed patients and 424 community controls across 10 years to investigate the association between depression and alcohol-related coping and to examine how life context vulnerabilities underlie the risk for depressed individuals to rely on drinking to cope. Findings supported all hypotheses. Depressed patients engaged in more drinking to cope than did community controls. Within individuals, more negative life events and less family support were associated with more drinking to cope across the 4 observations. Depressed patients experienced more negative life events and less family support than did community controls. These underlying life context vulnerabilities explained the relationship between depressed patient status and drinking to cope. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Project organization and contract management

The conceptual set-up of project organizations before tendering and contracting and their development and review during contract fulfilment is much more than a primitive art, today. The project organization can be designed and tailored to the actual objectives, phase, services, works, contract partners, and environmental conditions. Highly qualified organizational work is adequate to the important tasks of quality assurance and to using human talents and effort effectively.