Optimizing the features of the single-channel analyzer towards improvement of productivity of Mössbauer spectra

The statistical quality (productivity) of the Mössbauer spectra is one of the most important features characterizing the Mössbauer spectrometer. Optimizing the discrimination part of the spectrometer including the novel way of selection represents a route how to increase the spectrum productivity.     

Gewisse Segalsche Algebren auf lokalkompakten Gruppen

Ohne Zusammenfassung     

Programmable amplitude- and phase-modulated femtosecond laser pulses in the mid-infrared

We present a scheme to produce programmable phase- and amplitude-modulated femtosecond laser pulses in the mid-infrared regime of 3-10mum by difference frequency mixing. The 80-fs signal output of an optical parametric amplifier is shaped with a liquid-crystal mask and mixed in an AgGaS(2) crystal with a temporally stretched idler pulse. Without changing the mechanical alignment, we produce programmable amplitude modulations and chirped pulses at lambda=3mum with energy as high has thas 1muJ . This scheme, further, allows the generation of controllable pulse sequences. The results are in good agreement with theoretical simulations.     

On the Spectroscopic and Thermochemical Properties of ClO,BrO, IO,and Their Anions

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.     

On the flow around Glauert-Goldschmied body in the narrow channel and separation control strategy

Previously, there was tested a wire dielectric barrier discharge (DBD) plasma actuator to generate sufficiently strong ionic wind to affect freely developed boundary layer in the narrow channel. This paper will report about next step – to installation of actuator inside a streamlined body. The experiment will take place inside perspex rectangular (250 × 100 mm) channel and main task is to find the appropriate place for actuator fitting for three different flow regimes. Hence, the separation point and recirculation area will be investigated via PIV anemometry for base case and for active flow control methods (e.g. plasma actuator) as well as frequency spectrum of the flow will be evaluated to describe the nature of the flow. The measurement plane will be perpendicular to the bottom of the channel and in longitudinal level. These essential information will be used for actuator design, actuator embedding and to tune actuator frequency in order to suppress the recirculation area as much as possible. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Two‐photon excitation in chip electrophoresis enabling label‐free fluorescence detection in non‐UV transparent full‐body polymer chips

One of the most commonly employed detection methods in microfluidic research is fluorescence detection, due to its ease of integration and excellent sensitivity. Many analytes though do not show luminescence when excited in the visible light spectrum, require suitable dyes. Deep‐ultraviolet (UV) excitation (<300 nm) allows label‐free detection of a broader range of analytes but also mandates the use of expensive fused silica glass, which is transparent to UV light. Herein, we report the first application of label‐free deep UV fluorescence detection in non‐UV transparent full‐body polymer microfluidic devices. This was achieved by means of two‐photon excitation in the visible range (λ_ex = 532 nm). Issues associated with the low optical transmittance of plastics in the UV range were successfully circumvented in this way. The technique was investigated by application to microchip electrophoresis of small aromatic compounds. Various polymers, such as poly(methyl methacrylate), cyclic olefin polymer, and copolymer as well as poly(dimethylsiloxane) were investigated and compared with respect to achievable LOD and ruggedness against photodamage. To demonstrate the applicability of the technique, the method was also applied to the determination of serotonin and tryptamine in fruit samples.