16 research outputs found
Rainwater propagation through snowpack during rain-on-snow sprinkling experiments under different snow conditions
The mechanisms of rainwater propagation and runoff generation during
rain-on-snow (ROS) events are still insufficiently known. Understanding storage and transport of liquid water in natural snowpacks is crucial, especially for
forecasting of natural hazards such as floods and wet snow avalanches. In
this study, propagation of rainwater through snow was investigated by
sprinkling experiments with deuterium-enriched water and applying an
alternative hydrograph separation technique on samples collected from the
snowpack runoff. This allowed us to quantify the contribution of rainwater,
snowmelt and initial liquid water released from the snowpack. Four field
experiments were carried out during winter 2015 in the vicinity of Davos,
Switzerland. Blocks of natural snow were isolated from the surrounding
snowpack to inhibit lateral exchange of water and were exposed to artificial
rainfall using deuterium-enriched water. The experiments were composed of
four 30 min periods of sprinkling, separated by three 30 min breaks. The
snowpack runoff was continuously gauged and sampled periodically for the
deuterium signature. At the onset of each experiment antecedent liquid water
was first pushed out by the sprinkling water. Hydrographs showed four
pronounced peaks corresponding to the four sprinkling bursts. The
contribution of rainwater to snowpack runoff consistently increased over the
course of the experiment but never exceeded 86 %. An experiment conducted
on a non-ripe snowpack suggested the development of preferential flow paths
that allowed rainwater to efficiently propagate through the snowpack limiting
the time for mass exchange processes to take effect. In contrast,
experiments conducted on ripe isothermal snowpack showed a slower response
behaviour and resulted in a total runoff volume which consisted of less than
50 % of the rain input
Significance of the acrosome reaction and sperm agglutinating antibodies in human semen. acrosome RE
We commpared results of the acrosome reaction and sperm agglutinating antibodies in human semen samples
Balkán a migrace: Na křižovatce antropologických perspektiv
The collective monograph Balkans and migration includes five chapters written by anthropologically oriented researchers (L. Budilová, G. Fatková, L. Hanus, M. Jakoubek, M. Pavlásek) practicing a long-term research in the Balkan territory. In addition to general parameters of anthropological optics and an anthropological field research in the Balkans those particular studies are connected by study transversal theme of migration. While, however, the Balkans and anthropology in the publication are invariant framework guaranteeing the unity of the whole volume, the migration represent in this respect the constant variable. The given phenomenon is studied in case of various groups (Bulgarian and Romanian Czechs, Karakachans), and we can observe some aspects of its heterogeneous nature (post-war migration within the re-emigrant interstate agreements, seasonal labor migration, migration of farmers for the land, leaving the homeland because of religious disputes, etc.). The ambition of the monograph is to justify the relevance to attend to the fieldwork based research in the Balkans, and show why the new generation of anthropologists and other social scientists, practitioners, should pay their professional attention to the Balkan peninsula. Although Western anthropologists have been already focused on the Balkans for few decades, in Czech environment was this theme ignored by anthropologists and ethnographers. They yielded this interest to the political scientists, historians, travelers, and television reporters. This monograph is going to rectify this situation by a series of analyses applying different perspectives of the research. Those analyses are based on the interpretation of ethnographic data collected during the long-term field research. The Balkan peninsula and this terrain inhabiting populations are presented as a stimulating field for Czech anthropological researchers. An attractive topic reflected in those five chapters is the Czech expatriate presence in the Balkans. Until the present time there live several enclaves of Czech compatriots, who actively claim their Czech origin. Those enclaves adapt dynamically to the global political and economic changes. Not only the authors of this monograph have noticed that the science paradigm in the second half of the twentieth century, which is based on a priori national categorization, is not able to capture new social and cultural formations of minority groups living outside their „homeland“. An attempt to overcome the nationalistic classification of Czech (e) migration could be applied and grounded in many identification strategies taking place in the distant past. It seems that the time has come to revise the still dominant scientific approaches to expatriate minorities and expand their attention to the dimensions of collective life reflecting the changes in the last twenty years. The transformation of strategies of Czech expatriate minorities in topologically, economically and politically open Europe (hence the global environment) is a useful platform, where certain phenomena can be observed. Those phenomena produce inspiring issues of sustainability and transformation of collective identities in the contemporary world. Certain marginality of the region including more difficulties in accessibility of resources force the marginal populations to adapt to difficult conditions. These minorities are a good example for monitoring the development of organic solidarity patterns (in Durkheim sense) into more complex social structures, often „aside“ all scientific concepts of collective identification
The European project on high temperature measurement solutions in industry (HiTeMS) - a summary of achievements
High temperature measurement in industry is subject to large uncertainties due to the non-ideal measurement conditions; for example unknown emissivity and window transmission for radiation thermometry, sensor contamination and ageing causing unpredictable drift in contact thermometry. This paper gives an overview of a European Metrology Research Programme (EMRP) project “High Temperature Metrology for Industrial Applications” (HiTeMS) whose objective was to address, on a broad front, a number of unsolved measurement challenges in the domain of high temperatures (above 1000 °C) both in non-contact and contact thermometry. It brought together a total of 15 partner organisations; National Metrology Institutes (NMIs) (10), industrial companies (4) and a Fraunhofer Institute. The project started in September 2011 and was completed August 2014. Significant progress has been made in all the temperature measurement challenges tackled