Franz Holawe

UV Exposition During Typical Lifestyle Behavior in an Urban Environment

In this study the personal exposure to solar UV radiation in an urban environment was measured. Lifestyle in an urban environment is characterized by staying indoors during most of the day. Furthermore, the ambient UV radiation is mitigated by shadowing by buildings. The aim of the study was to find out activities which may contribute to UV‐induced health risk in a low exposure environment. Exposure was measured during typical outdoor activities: shopping, walking, sitting in a sidewalk café, cycling, sightseeing and at an open‐air pool (solar elevation: 10°–70°). Measurements were taken with an optoelectronic device which was fixed on the chest. Besides the UV Index we used the sun burn time (SBT) for risk assessments. Generalization of our results was made by calculating ratios of personal exposure to the ambient UV radiation. UV exposure was by far the highest when our study subject stayed at the swimming pool. The SBT was around 30 min for melano‐compromised skin type. For all other activities, except shopping, the SBT range up to 1 h. With respect to photodamage we found that at high solar elevation (>45°) photoprotective measures should be applied for certain activities even within a city.

Daily weather observations in sixteenth-century Europe

Thirty-two weather diaries written in astronomical calendars in central Europe in the late fifteenth and sixteenth centuries are presented and discussed. Systematic weather observations were promoted by the rise of planetary astronomy and its application in astro-meteorology. The practice of keeping weather diaries spread from Cracow (Poland) to Ingolstadt (Germany) and from there to other universities. The data obtained from these sources provided the backbone for setting up series of precipitation indices for Poland, Germany and Switzerland. Monthly statistics of days with precipitation, snowfall and frost were computed by counting the relevant entries in the most important diaries. The results were compared with either those obtained from instrumental measurements in the same place or with those from modem instrumental measurements in a neighbouring place. The final results show that autumn was considerably colder in the early sixteenth century. April was considerably drier and July was wetter during the period 1508–1531 than during 1901–1960. In order to highlight the impact of weather patterns on grain prices in a year of crisis, the timing of wet and dry spells in southern Poland and southern Germany is compared for the year 1529. Winters became 1.7°C colder from 1564 to 1576 and the month of July tended to be wetter than in 1901–1960. Details noted in the diaries kept between 1585 and 1600 by the astronomers Brahe (near Copenhagen) and Fabricius (in the Ostfriesland region of northwestern Germany) closely agree. It rained more often in June and July and temperatures dropped. The winter months were more frequently dominated by winds from easterly directions, the frequency of snowfall was higher and a deficit occurred in precipitation. This points to a higher frequency of high pressure in the Fennoscandian area with cold air advection from the east or northeast.

Quicklime application instantly increases soil aggregate stability

Abstract Agricultural intensification, especially enhanced mechanisation of soil management, can lead to the deterioration of soil structure and to compaction. A possible amelioration strategy is the application of (structural) lime. In this study, we tested the effect of two different liming materials, ie limestone (CaCO3) and quicklime (CaO), on soil aggregate stability in a 3-month greenhouse pot experiment with three agricultural soils. The liming materials were applied in the form of pulverised additives at a rate of 2 000 kg ha−1. Our results show a significant and instantaneous increase of stable aggregates after quicklime application whereas no effects were observed for limestone. Quicklime application seems to improve aggregate stability more efficiently in soils with high clay content and cation exchange capacity. In conclusion, quicklime application may be a feasible strategy for rapid improvement of aggregate stability of fine textured agricultural soils.

An inexpensive and reliable atmometer for estimating evaporation from sandy surfaces

SummaryA modern modification to an inexpensive atmometer, of long-standing design, is demonstrated. In field experiments, Cantoni atmometers were observed to respond sharply to variations in solar radiation. Furthermore, this inexpensive instrument correlates well with the more expensive Livingston atmometer, and has proved to be a reliable indicator of potential evaporation from small pots of wet sand, mounted as micro-lysimeters.

Determination of the received daily visible and UV radiation dose as a function of weather, environment, and activity

The determination of UV- and light doses received by people as a function of their activities and their environment, for present and future conditions, is the aim of the presented study. In this paper we present first preliminary results. Measurements of the total daily UV dose received by horizontal and vertical parts of the human body were performed on three chosen days in the region of Vienna, Austria. The measurements were performed in the UV and in the visible spectral range using ultraviolet selective sensors and sensors adapted to human eye sensitivity. Data acquisition was performed by using dataloggers. In this way it was also possible to determine the UV intensity and dose as a function of time and location. The UV intensity was determined for typical outdoor and indoor activities such as walking in a street, in a forest or in flat unobstructed areas. Indoors the determination of UV doses is more straightforward, the determination of the visible dose is however much more complex. A software was developed to determine the total daily dose received by the human body as a function of day and occupation.