The traditional compensation model to explain the high resistivity properties of CdTe is based on the presence of a deep acceptor level of the cadmium vacancy in the middle of the band gap. A new compensation model based on a deep intrinsic donor level is presented. The compensation model is used together with an appropriate segregation model to calculate axial distributions of resistivity which are compared with spatially resolved resistivity measurements. The Te-antisite defect is discussed as a possible origin cause of this intrinsic defect, which is also supported by theoretical calculations.

The aquatic application of the eddy correlation (EC) technique is growing more popular and is gradually becoming a standard method for resolving benthic O 2 fluxes. By including the effects of the local hydrodynamics, the EC technique provides greater insight into the nature of benthic O 2 exchange than traditional methods (i.e., benthic chambers and lander microprofilers). The growing popularity of the EC technique has led to a greater demand for easily accessible and robust EC instrumentation. Currently, the EC instrumentation is limited to two commercially available systems that are still in the development stage. Here, we present a robust, open source EC picoamplifier that is simple in design and can be easily adapted to both new and existing acoustic Doppler velocimeters (ADV). The picoamplifier has a response time of < 0.1 ms and features galvanic isolation that ensures very low noise contamination of the signal. It can be adjusted to accommodate varying ranges of microelectrode sensitivity as well as other types of amperometric microelectrodes. We show that the extracted flux values are not sensitive to reduced microelectrode operational ranges (i.e., lower resolution) and that no signal loss results from using either a 16-or 14-bit analog-to-digital converter. Finally, we demonstrate the capabilities of the picoamplifier with field studies measuring both dissolved O 2 and H 2 S EC fluxes. The picoamplifier presented here consistently acquires high-quality EC data and provides a simple solution for those who wish to obtain EC instrumentation. The schematic of the amplifier's circuitry is given in the Web Appendix.

Investigation of human diet during the Neolithic has often been limited to a few archaeological cultures or single sites. In order to provide insight into the development of human food consumption and husbandry strategies, our study explores bone collagen carbon and nitrogen isotope data from 466 human and 105 faunal individuals from 26 sites in central Germany. It is the most extensive data set to date from an enclosed geographic microregion, covering 4,000 years of agricultural history from the Early Neolithic to the Early Bronze Age. The animal data show that a variety of pastures and dietary resources were explored, but that these changed remarkably little over time. In the human δ15N however we found a significant increase with time across the different archaeological cultures. This trend could be observed in all time periods and archaeological cultures (Bell Beaker phenomenon excluded), even on continuously populated sites. Since there was no such trend in faunal isotope values, we were able largely to exclude manuring as the cause of this effect. Based on the rich interdisciplinary data from this region and archaeological period we can argue that meat consumption increased with the increasing duration of farming subsistence.In δ13C, we could not observe any clear increasing or decreasing trends during the archaeological time periods, either for humans or for animals, which would have suggested significant changes in the environment and landscape use. We discovered sex-related dietary differences, with males of all archaeological periods having higher δ15N values than females, and an age-related increasing consumption of animal protein. An initial decrease of δ15N-values at the age of 1–2 years reveals partial weaning, while complete weaning took place at the age of 3–4 years.

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The transition-metal ion vanadium in CdTe is studied using electron paramagnetic resonance ͑EPR͒ and photo-EPR. Based on the observation of central hyperfine interaction, the EPR measurements identify two vanadium related defects. They are assigned to V 3ϩ and V 2ϩ , both substitutional for Cd. Whereas V 3ϩ shows the classic isotropic EPR spectrum, the V 2ϩ spectrum features triclinic symmetry caused by a strong Jahn-Teller coupling to both 2 and ⑀ vibronic modes. By means of photo-EPR the V 2ϩ /V 3ϩ -donor level is determined at 0.67 eV below the conduction band.