A simple automatic phototitrator for the determination of total carbonate and total alkalinity of sea water

An automatic photometric analyser based on the reversed use of a conventional motor syringe buret and modern optoelectronic components is described. The buret serves as a photometric titration vessel into which sample and reagents are selectively drawn through a set of solenoid valves. It has been applied to the photometric titration of total alkalinity and total carbonate concentration of sea water, giving precisions of 0.10% and 0.13%, respectively.     

A Mössbauer spectroscopy study of polyol synthesized tavorite LiFeSO4F

The tavorite polymorph of LiFeSO₄F has attracted considerable attention as a cathode material for lithium ion batteries due to interesting structural and electrochemical characteristics. For the analysis of such iron-based electrode materials, Mössbauer spectroscopy has become an important and highly useful tool. In this work, we perform a detailed Mössbauer study of pristine tavorite LiFeSO₄F prepared by an optimized synthesis in tetraethylene glycol as reaction media. In contrast to many reported results, we demonstrate the use of an asymmetric fitting model for the inner doublet of the spectrum, which is coupled to the structural properties of the compound. Moreover, we discuss a new approach of ascribing the Fe^2?+?-doublets to the two distinct crystallographic iron sites of tavorite LiFeSO₄F by comparing the Mössbauer signal intensities with the expected f-factors for the corresponding iron atom.     

A field study of effects of road traffic and railway noise on polysomnographic sleep parameters

The aim of this study was to explore and compare the effect of noise from railway and road traffic on sleep in subjects habitually exposed to nocturnal noise. Forty young and middle aged healthy subjects were studied with polysomnography (PSG) during two consecutive nights in their own bedroom. Noise measurements and recordings were conducted concurrently outside of the bedroom fac?ade as well as inside the bedroom of each participant. Different noise exposure parameters were calculated (L(p,A,eq,night), L(p,A,Fmax,night), and L(AF5,night)) and analyzed in relation to whole-night sleep parameters. The group exposed to railway noise had significantly less Rapid eye movement, (REM) sleep than the group exposed to road traffic noise. A significant association was found between the maximum level (L(p,A,Fmax,night)) of railway noise and time spent in REM sleep. REM sleep was significantly shorter in the group exposed to at least a single railway noise event above 50 dB inside the bedroom. These results, obtained in an ecological valid setting, support previous laboratory findings that railway noise has a stronger impact than road traffic noise on physiological parameters during sleep, and that the maximum noise level is an important predictor of noise effects on sleep assessed by PSG, at least for railway noise.