Josef Zeman

Impact of evapotranspiration on discharge in small catchments

Abstract We apply the Linear Storage Model (LSM) to simulate the influence of the evapotranspiration on discharges. High resolution discharge data from two small catchments in the Czech Republic, the Teply Brook and the Starosuchdolsky Brook catchment are used. The results show the runoff process is simpler in a deeper valley of the Starosuchdolsky catchment where the soil zone is deeper and the valley bottom recharges runoff even during very dry periods. Two-soil zone model is adequate to simulate the diurnal runoff variability. Three-soil zone model is needed in the Teply Brook catchment due to the absence of water transport in the most-upper soil zone. Time delays between minimum and maximum discharge during the day reach up to about 20 hours. Evapotranspiration and hydraulic resistances are as high as 14% of catchment daily runoff in the urbanized Starosuchdolsky Brook catchment and 25% of catchment daily runoff in the forested, less impacted Teply Brook catchment

The Evaluation of the Tremor: Signal Database of Healthy Control Subjects

A tremor an involuntary rhythmic oscillatory movement of a part of the body—belongs to one of the most disabling features of multiple sclerosis (MS). In clinical practice, the tremor is currently classified according to clinical scales. Unfortunately, this approach is fully subjective in principle, and the objective classification is still missing. As is shown in the literature, the tremor can be investigated by accelerometers and gyroscopes based on the frequency analysis and other advanced methods of signal processing. A condition of the successful development of these methods is an existence of a signal database of healthy subjects. This paper concerns with the collecting of the signal database of healthy control subjects. The signals were acquired on the group of healthy subjects aged from 18 to 50 years (20 subjects). For each patient, one-minute records of postural tremor (for both right and left hand, with and without closed eyes; 4 records together) have been acquired, and also several clinical tests have been passed (a measurement of a strength by a handgrip, a pinch key, and a trippod test, a nine-hole peg test, a coin rotation task test, and a tip pinch test). All records have been supplemented by anamnestic data.

Stream Level Stabilization by Algae of the Genus Cladophora

Abstract Investigations in the Pryský brook experimental catchment revealed that the vegetation of the stream channel stabilizes water level depth in the measured profile. The explored brook has been heavily overgrown by algae of the genus Cladophora due to a strong pollution by nitrates. It seems that if the algae average length exceeds the midsize of the stones paving the bed (ca. 30 ± 7 cm in diameter, escribed circle to pentagon or heptagon), the water level stagnates in the flowrate range of 60–180 l s−1. This totally blocks the streamflow daily oscillation (in summer months in a purely stone bed reaching up to 15%, along with tidal phenomena). The article analyzes one of possible explanations of this effect due to the dependence of the algae thickness layer modifying the channel bed cross-section on the speed of flowing water.

Design and realization of measuring device for tremor evaluation

Tremor as an involuntary rhythmic oscillatory movement of a body part belongs to one of the most disabling features of multiple sclerosis. Our research presented in this paper deals with the developing of an evaluation system of tremor. The system which was designed and realized consists of the portable telemetry units with accelerometers and the base station. The system is able to store 3 axes accelerometry data in the dynamic range of ± 8 g and the sample frequency of 50 Hz. The system allows storing raw data for further processing in PC. The device was verified in the experiment with the gravitational acceleration. The illustration of results from pilot study are presented in the result section. These results show the system ability to trace various types of tremors and distinguish between them.