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Notwithstanding the genus Italobdella has been hypothesized to have doubtful taxonomic value, we decided to update its diagnosis by describing the new species – Italobdella bieleckii sp. n. The leeches were collected from the stony bottom along the shore of the Danube River in Slovakia. In the study, we implemented the model of leech body form and the set of external and internal morphological characters to present the similarity of the new species to the other fish leeches. As a result, we were able to construct the key for determining leeches belonging to the genus Italobdella hoping that the species could be found and determined by other researchers. This would enrich our knowledge about the actual distribution of these leeches and strengthen their systematic position in the genus.

A new species of histiostomatid mite — Myianoetus sovat sp. n., based on the deutonymph, is described from the fly Gymnomus caesius. It differs from other species of Myianoetus by more characters of idiosomal morphometry, body and leg chaetotaxy, solenidiotaxy and shape of the adhering disc and its structures.

In the Czech part of the Labe River and the lower part of the Vltava River, we examined if the benthic macroinvertebrate composition changed from 1996 to 2005 due to expected improvements in water quality resulting from socioeconomic changes in the Czech Republic since the 1990s. Special attention was given to rare and alien species. The four biological metrics used (Number of taxa, BMWP, Number of sensitive taxa, and Number of EPT taxa) demonstrated that there was indeed an improvement in water quality as well as a slight improvement of the Labe microhabitats during the investigated period. An increasing Number of taxa over time was observed at most sites. Two main concurrent ecological processes are recently in progress in the Labe: a recovery of native species and an expansion of alien species, some of which are considered invasive. The caddisfly Setodes punctatus and the beetle Pomatinus substriatus, considered as regionally extinct in the Czech Republic until 2005, were rediscovered during our investigations. Findings of the crustacean Hemimysis anomala (invasive) and the chironomids Stenochironomus sp. and Lipiniella sp. were the first records of these taxa in the Czech Republic.

A simulation approach is presented which can be used to investigate electro-thermal behavior of power transistors in variety of operating conditions. The approach is discussed in detail and demonstrated using ANSYS simulator. The power transistor is considered as a distributed voltage controlled resistor consisting of many in parallel connected cells. Because every cell has individual gate– and drain–source voltage, 3-D effects depending on geometric configuration and used materials can be observed. This is shown on a simple power transistor model for three principal electrical operating points: below TCP (temperature compensated point), at TCP and above TCP. Additionally, a mix-mode operating point is showed. The simulation results show 3-D effect of current density distribution as a function of the operating points. The results showed very good agreement with the prediction from the theory and already published results achieved by 3-D modeling approaches.

The leech Dina punctata Johanson, 1927 inhabits various types of running waters. This species appeared in Slovakia probably after the first Rhine-Main-Danube canal was built. Because little is known about its ecology, the aim of our study was to analyze the life cycle, individual growth rate, reproduction parameters and food composition of D. punctata in the Vydrica Stream. Samples of leeches were taken mainly each month from April 2003 to November 2004. The leech D. punctata had maximal 2-year life cycle there. Mature leeches, which were recognized by the presence of clitella, were present from April to the end of August. The most individuals mature at the age of 1 year. The breeding season of D. punctata peaks in June. The number of eggs per one cocoon is from 3 to 12. The mean successfulness of development of egg to embryo is 58%. Larvae from the family Chironomidae (28%), Gammarus fossarum (20%) and oligochaetes from the subfamily Naidinae (17%) are the dominant components of the feeding niche. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The relevance of thermally non-linear silicon material models for transient thermal FEM simulations of smart power switches (SPS) is proved by a power silicon test device consisting of two power transistors and eleven integrated temperature sensors distributed over the silicon die. The test device is heated up by turning on an integrated power transistor in short-circuit for several milliseconds at two different initial temperatures. These thermal events correspond to a real situation that can occur in the application. The power dissipation in the power transistor is calculated from the measured source current and drain-source voltage, and subsequently used as an input to the FEM simulation. The temperature change on the test chip is measured by the integrated temperature sensors. An FEM model of the test chip encapsulated in a plastic package has been built in the FlexPDE simulator. The emphasis is put on the macroscopic modeling of the power transistor where an electro-thermal approach is reduced to a purely thermal one. Finally, the thermal events are simulated using FEM and compared to the temperature measurements. The results have shown that our modeling approach including non-linear properties of silicon can be used to investigate the thermal transients in SPS devices with high accuracy.

Freshwater leeches (Annelida: Clitellata: Hirudinida) of the Czech Republic were studied on the basis of recent literature, information in selected databases, and results of recent surveys conducted by the authors. The objectives of this study were to summarize recent taxonomic information, and to update the check-list of leeches using records collected during an eleven-year study (1998 through 2008). Altogether, twenty-four species representing 12 genera and five families are reported for the Czech Republic, including the first reports of Piscicola cf. haranti Jarry, 1960 and Dina punctata Johansson, 1927 for the country. A detailed description of the distributions of rare species and characterization of localities from which they are reported are presented. Plausible modes of dispersal and propagation of species in Central Europe are discussed. According to recent records, leech species are divided into three groups: indigenous species with stable and strong populations (12 species), indigenous species with weak populations known from a limited number of localities (9 species), and species only recently recorded in the Czech Republic (3 species). For scarce or rare species, a category of threat in the Czech Republic according to the International Union for Conservation of Nature is recommended. Most of threatened species are inhabitants of lowland wetlands and lowland larger rivers—habitats that are negatively impacted, often catastrophically, by human activities throughout Central Europe. The protection of suitable habitats is the most effective way to protect extant populations of endangered leech species. Six species of leeches are recommended for permanent addition to the Red list of threatened species in the Czech Republic.

A calibrated system for power metal reliability analysis in smart power technology chips is presented. This system is mainly designed for temperature evaluation during temperature-cycling experiments. Infrared camera measurements under single shot high energy pulses are correlated with electro-thermal finite element simulation and failure analysis. A special test structure, containing poly-silicon heaters, is used to produce thermal stress. The location of a hot spot agrees well with the position of degraded power metal.

Active cycle stress testing of smart power switches is conventionally performed either with current pulses of constant amplitude or with waveforms derived by switching inductive loads. A flexible test system is introduced that is capable of generating arbitrary current pulse shapes, which is verified experimentally on a typical smart power switch. It is demonstrated by a test run that pulses with different shape and amplitude but equal thermal stress derived from thermal simulation lead to comparable cycle life time.

When performing electro-thermal simulations of power semiconductors, usually the FEM model of the device does not include small geometrical features in order to limit the computational effort. In this paper we propose a method to replace the detailed elementary cell structure of a power Trench MOSFET by thermally equivalent homogenous layers with averaged anisotropic material properties. The impact of equivalent material models on the device behavior is evaluated and compared to an isotropic model by means of electro-thermal simulations.

Electro-thermal simulators are useful tools for introducing design and technology improvements during the design process of power MOSFET transistors. They are also helpful to predict the device behavior when operating under extreme electrical and temperature conditions and thus to predict its thermal robustness. Such simulators have to correctly take into account interactions between electrical and thermal behavior. In this paper we propose a new method to perform electro-thermal simulations of power MOSFETs using ANSYS simulator. The electrical and the thermal problem are fully coupled and iteratively solved using the FEM method. By means of a test chip, simulations and comparison with measurement have been performed in order to validate the simulation approach.

This paper presents a method for the compact modeling, simulation and experimental verification of digital protection functions of smart power switches consisting of a digital controller and a power MOSFET with analog driving circuitry. We focus on short circuit events in an automotive environment where high power dissipation and thermal stress severely affect device reliability. For accurate temperature calculation, a non-linear thermal network including coupling between power transistor channels is used. A digital strategy for over current limitation, short circuit detection and over-temperature shutdown is modeled using SystemC-AMS and verified experimentally using a hardware-in-the-loop system.

in this contribution we show how the joint use of finite elements (FEM) thermal simulations together with validation through a state-of-art experimental setup which is capable of detecting temperature transients with 100 kHz equivalent bandwidth capability allows for an optimal comprehension of the electro-thermal interactions taking place in low-voltage Smart Power MOSFETs. In particular, we propose the usage of an experimentally validated numerical simulator to foresee the maximum temperature swing occurring on the device area in order to evaluate mechanical stresses at bond wire joints that can lead to reduced reliability of the device and, eventually, to failure.

Cycle life testing of smart power switches requires significant hardware effort to provide the required ohmic-inductive load patterns. A new reliability test system for research purposes is therefore introduced that generates arbitrary current waveforms to emulate inductive switching behavior. This allows flexible cycle stress testing of integrated power switches under arbitrary application conditions. The current drivers of the proposed "ARCTIS" test system are protected from thermal overload in case of failure of a stressed device using a combination of case temperature sensing and a thermal equivalent circuit. Therefore the power MOSFETs in the output stage may be utilized to the limits of their dynamical safe operating area. All devices under test are continuously monitored for short circuit and open load failures. The respective waveforms and failure events are digitally recorded by the PXI-based control system to obtain a statistical basis for the evaluation of cycle life time.

We present the comparison of optical properties of semiconductor stripe lasers including monolayer InAs/GaAs short period superlattice active layers with and without vertical resonant cavity, respectively. The differences between the performances of the conventional laser with vertical cavity indicate a positive influence of the microcavity on the stability of mode spectra as well as decreasing of threshold current density and their temperature dependence. For the first time the stimulated emission from these combined longitudinal and vertical resonant cavity structures was investigated which is highly interesting for potential device applications.