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P- and n-doped bismuth telluride (Bi2Te3) polycrystalline nanostructures were prepared on structured PECVD-oxide-layers using magnetron sputtering and a lithography independent deposition and back-etching step. The resulting polycrystalline spacer-structures have adjustable dimensions with heights of 350 to 450 nm, a widths of 200 to 220 nm and a fix length of 1240 μm and 4020 μm. This paper presents the production of Bi2Te3 structures and how annealing affects the electrical conductivity in order to improve their potential in thermoelectric applications. In addition to temperature variation and multiple annealing the influence of different atmospheres during the annealing step has been investigated. It is shown that the electrical conductivity of the p-doped material increases by a factor of 1.8, while it decreases for the n-doped material.

Thin-film thermoelectric generators (TFTEGs) can provide energy for ultra-low power devices such as microscale heaters, cooling-units, and autonomous sensors and actuators. Of particular interest are micro- and nano-structured thermoelectric materials deposited on organic substrates, which allow fabrication of ultra-fast Peltier elements, mechanically flexible TFTEGs, and integration of TFTEGs in transparent microfluidic cells. In this study we report on an integration process of bismuth telluride based cross-plane TFTEGs on polyimide as a model material for organic substrates by adapting a well-established planar technology method. The main advantage of this approach is that the length of the thermopiles is independent on the thickness of the thermoelectric materials, which allows for fabrication of TFTEGs with high aspect ratio.

The Rotliegend saline lake periodically covered wide areas of the Southern Permian Basin in Northwest Europe during the Permian. The sedimentology, mineralogy and geochemistry of lake deposits were studied to document very high frequency lake level fluctuations and to evaluate their triggers. Increased precipitation and marine ingressions into the basin resulted in lake extension. Increased run-off is documented by intercalated fluvial deposits in low-salinity deposits of the lake. Because lake deposits reflect mainly deposition in relatively wet climate phases, they are not correlatable to halite deposits in other basin areas. Decreased precipitation is followed by shrinkage of the lake, desiccation at its margins, and higher lake salinity due to concentration of the brine. Carbonate and anhydrite contents of lake deposits increased considerably before the areas fell dry, but halite is not preserved in the study area. Falling lake level is also reflected by the occurrence of wave ripples, reflecting decreased water depth and finally by desiccation and formation of evaporite crusts. Not only the mineralogical content, but also the colour of lake claystones changes with varying salinity. Anhydrite- and carbonate-free red claystones were replaced by violet to green and grey anhydritic and calcareous claystone or marls with increasing salinity. The amount of boron adsorbed on illite also corresponds to changes in salinity and can therefore be used as a palaeosalinity indicator. Rare earth element concentrations within lake deposits do not reflect variations in salinity but different palaeogeographical settings. Marine ingressions into the lake are neither reflected by the amount of boron adsorbed onto illite nor by rare earth element contents of the lake deposits. Highly saline deposits are partly characterised by intensive deformation, which can be interpreted as seismites or dissolution breccias.

Methods permitting to test the influence of the matrix as well as of its local and temporal distribution on the plasma conditions in laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) are developed. For this purpose, the MS interface is used as plasma probe allowing to investigate the average plasma condition within the ICP zone observed in terms of temporal and spatial distribution of the matrix. Inserted matrix particles, particularly when being atomized and ionized, can cause considerable changes in both electron density and plasma temperature thus influencing the ionization equilibrium of the individual analytes. In this context, the plasma probe covers a region of the plasma for which no local thermodynamic equilibrium can be assumed. The differences in temperature, identified within the region of the plasma observed, amounted up to 3000 K. While in the central region conditions were detected that would not allow efficient atomization and ionization of the matrix, these conditions improve considerably towards the margin of the area observed. Depending on the nature as well as on the temporally and locally variable density of the matrix, this can lead to varying intensity ratios of the analytes and explain fractionation effects. By means of a derived equation it is shown that the deviation of the intensity ratio from the concentration ratio turns out to be more serious the higher the difference of the ionization potential of the analytes observed, the lower the plasma temperature and the higher the matrix concentration within the area observed.

Signal equations basing on dispersion functions describing the measured temporal intensity distribution for laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) used in scanning and drilling mode are developed. Variable ablation rates due to either varying focussing conditions typical for drilling mode and due to the changes of physical and chemical properties in inhomogeneous samples as typically investigated in scanning mode are considered for. The model accounts for intermixing of the sample aerosol within the sampling chamber, the influence of transport in a cylindrical transport channel and the fact that normally not the entire vapour generated and transported to the ICP can be observed. The absolute signal response is influenced by the actually ablated, transported and observed analyte mass. The dispersion functions describing the relative signal response depend on sample chamber volume, the volume of the transport channel, the laser shot frequency, the carrier gas flow rate and the part of observable cross-section at the MS interface compared to the entire cross-section filled by the vapour. All these parameters depend on the experimental set-up and the selected operating conditions only. Using the signal equation the influence of all mentioned parameters on signal course is shown both theoretically and experimentally. The signal equation can be used for calculation of optimal experimental conditions. On this basis, an algorithm is proposed providing the relative temporal distribution of any analyte with significantly higher temporal resolution than the measured temporal intensity distribution itself. Furthermore, usage of dispersion functions for investigation of a given transport system, for explanation of typical signal deviations, for the proof of homogeneous regions in a heterogeneous sample, for examination of changes in ablation rate and for investigation of fractionation effects is shown.

A transport model is proposed that describes the temporal intensity distribution observed in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) in single-shot mode using quantitative signal equations. Calculations aim on the deduction of the dispersion function describing the time-dependent part of the signal equation. The dispersion function depends on transport time in the centre of the transport tube, as related to carrier gas flow rate and tube volume and on the relation between carrier gas flow rate and ablation chamber volume. The equations describing the signal shape standardize signals from different systems and allow quantitative optimization of the ablation chamber, the transport tube and the detector. Application of the model to ICP-MS shows that only a part of the area filled by the transported vaporization product and thus only a part of the transported vaporization product can be observed at the detector. The model is able to quantify both fractions. As was calculated, the observed fraction of analyte is always higher than the observed fraction of the sample containing cross section and depends on the chosen transport parameters characterising the dispersion function. Thus, the determination of the signal integrals in the usual way can lead to systematic errors if the parameters influencing the dispersion function are variable. Therefore, a different method of analysis based on signal equations is proposed and demonstrated. By this method of data treatment, all important system parameters influencing the dispersion function could be calculated and matched with theoretical ones. Furthermore, a complete integral of the transient signal including its statistical variation can be generated from a limited number of measurement points. For example, this can be applied to signals detected incompletely because of detector saturation and enables the use of high-abundance elements as internal standards. Furthermore, the method can be used to monitor system performance, to identify the flow regime inside the ablation chamber, to take into account the sample volume for quantitative analysis and finally, to detect anomalous signal distributions that would lead to systematic errors. The prospects and limitations of the model are discussed for LA-ICP-MS in single shot mode.

Rapid sequential atomic emission spectrometry with the ‘Zig Zag’ acquisition system (ISA Jobin Yvon, France) in the case of the inductively coupled plasma is described. The ‘Zig Zag’ system is shown to enable the application of spectral stripping, as both the reproducibility of the intensities measured, for several lines of Fe, and the reproducibilty of the wavelength positioning (errors below 3 pm in the 2nd order and 5 pm in the 1st order) were found to be high. Using an integration time of only 2.5 ms/point, the precision of the intensities expressed as the relative standard deviation is below 5%. These features are shown to allow spectrum stripping from the contribution of a Zr matrix, which has a rather line-rich atomic emission spectrum. Spectrum stripping was applied in the wavelength range from 237.9 to 241.1 nm, where 10 of the most sensitive emission lines of Fe were found. For sample solutions with 500 mg/l Zr only, 10 mg/l Fe only, 500 mg/l Zr as well as 10 mg/l Fe, and for a blank solution, respectively, five spectral scans were averaged and the averaged spectral scan for a blank solution was subtracted. The spectral scan obtained for a solution containing 500 mg/l Zr only was subtracted from the one obtained for the solution containing both 500 mg/l Zr and 10 mg/l Fe. The result of spectral stripping is comparable to the experimentally obtained spectral scan for the solution containing 10 mg/l Fe only after blank subtraction. The recovery for Fe was found to be 93±2% and is therefore comparable to the one obtained by chemical separation methods using solvent extraction. When using an integration time of 50 ms per measurement point instead of 0.5 ms/point, as it is possible in the case of the ‘Zig Zag’ approach, the detection limit for Fe in the measurement solutions can be improved from 20 down to 3 μg/l, or from 40 to 6 μg/g Zr, respectively.

This paper is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta, Part B (SAB). This hardcopy text, comprising the main body and an appendix, is accompanied by a disk with programs, data files and a brief manual. The main body discusses purpose, design principle and usage of the computer software for modelling the evaporation behaviour of particles in inductively coupled plasma atomic emission spectrometry (ICP-AES). Computer software has been developed in FORTRAN 77 language in order to simulate the evaporation behaviour of particles of refractory materials such as encountered in the analysis of advanced ceramic powders by slurry nebulization inductively coupled argon plasma atomic spectrometry. The program simulates the evaporation of single particles in the inductively coupled plasma and also enable it to calculate on the base of a given particle size distribution the evaporation behaviour of all the particles contained in a sample. In a so-called “intensity concept”, the intensity is calculated as a function of the observation height in order to determine recovery rates for slurries compared with aqueous solutions. This yields a quick insight whether a calibration with aqueous solutions can be used for analysis of slurries of a given powder by slurry nebulization ICP-AES and also is a help in determining the optimal parameters for analyses of powders by means of slurry nebulization ICP-AES. Applications for the evaporation of Al 2 O 3 and SiC powders document the usefulness of the model for the case of a 1.5 kW argon ICP of which the temperature at 8 mm above the load coil has been determined to be 6100 K. The model predicts the maximum particle size for SiC and Al 2 O 3 that can be transported (10–15 μm) and evaporated for a given efficiency under given experimental conditions. For both Al 2 O 3 and SiC, two ceramic powders of different grain size were investigated. The median particle sizes cover the range typical of ceramic powders. Investigations were made for SiC A 10 (median particle size 2.2 μm), SiC F1200 (4.3 μm) and Al 2 O 3 AKP 30 ( μ m) and Al 2 O 3 Cilas 715 (3.0 μm), respectively, in which particles with diameters of up to 23 μm still are found.

This paper describes the East German energy sector and its fate after 1990 with particular emphasis on environmental regulation. Unification turned the enlarged Federal Republic of Germany into a rather dirty country and the world's largest producer of brown coal. While primary energy demand in the West rose by almost 10% in 1991, it fell by about 30% in the East and demand was not expected to return to its pre-Wende (U-turn) value until 2005, in spite of advancing privatization and energy price rises to Western values. In late 1991 Esso expected a permanent decline. During 1991 upheavals and uncertainty dominated life in the former German Democratic Republic; by mid-1992, bitterness described the public mood and first signs of a political separatism could be detected. Optimists had hoped that by the year 2000 at the latest, a planned economy devoted to energy self-sufficiency would have become fully integrated into the West with the achievement of similar living standards. Evidence so far supports the pessimists who observe rapid industrial decline and the relative impoverishment of large sectors of the population, possibly leading to political destabilization. The ability of market forces to transform communism is being tested, as is the ability of society to shed its socialist inheritance without psychological disintegration. The process itself is as bewildering as it is fascinating. Its outcomes surely hold lessons for developments elsewhere, especially for the role of government in transitional economies and the capacity of environmental regulation to facilitate macroeconomic change.

In three quarters of those patients with lymphoreticular tumors (reticulum cell sarcoma and lymphoreticular sarcoma) the disease begins in lymph nodes and in one quarter of the cases in extranodular organs. If patients are suffering from primary lymph node involvement, the disease tends to be widespread. In patients with primary organ involvement the disease remains limited to local regions for a longer time and shows a greater tendency towards a continuous rather than a discontinuous spread. Patients with primary lymph node and organ involvement have almost the same prognosis when receiving the same treatment: In stages I and II the 5 year survival rates for primary lymph node involvement is 50% , for primary organ-involvement, 59% . The corresponding percentage rates of permanent cure are 48% and 45% . Under present therapy conditions, the prognosis of both forms in the advanced stages III and IV is very unfavourable. Comparative prognosis renders it possibly advisable to classify patients with primary lymph node and organ involvement together.