Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 110
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Fourteen symposia on early/lower vertebrates have taken place over the last 50 years, usually at about four year

intervals. An average 60 participants have taken part at these symposia, with over one hundred occasionally. The

results of the symposia have been published in proceedings. The symposia started honoring E. A:son Stensiö and

E. Jarvik. Honors were taken up at the 11th symposium in Uppsala again. Since the 13th symposium a Stensiö

award is also given to young researchers in the field.

Go to article

Authors and Affiliations

Hans-Peter Schultze
Download PDF Download RIS Download Bibtex

Abstract

The central question of the article is should Stanisław Lem be read as a futurologist? The main thesis is that more than in predicting the future Lem always has been more interested in exploration the conceptual limits of science and its technological offshoots.
Go to article

Authors and Affiliations

Peter Swirski
1

  1. Canadian scholar and novelist
Download PDF Download RIS Download Bibtex

Abstract

We are familiar with the grammar and logic of relational predicates in predicate calculus, chiefly as transmitted through Whitehead and Russell. In natural languages however, relations are frequently expressed using what Peirce called relatives, that is, expressions like brother, gift, head, effect, successor, which require completion by one or more definite terms to yield general names or terms. Peirce developed a logic of such relatives which influenced Schröder and Tarski. Later, Leśniewski used relative terms such as part, overlapper, class etc. to formulate his mereology, rather than the predicates and operators subsequently and more standardly used. In this paper I con-sider aspects of the grammar and logic of such relative terms, particularly in regard to several areas of general logico-philosophical interest: cardinality; functions; abstrac-tion; the order problem of relations; and Russell’s multiple relation theory of belief and judgment.

Go to article

Authors and Affiliations

Peter Simons
Download PDF Download RIS Download Bibtex

Abstract

This article traces the process by which Ricoeur establishes the character of the discipline of history as a form of narration which expresses the relation between the experience of ‘belonging-to-history’ and the capacity to place this experience at a distance and, thereby, to experience it reflectively.

Go to article

Authors and Affiliations

Peter Langford
Download PDF Download RIS Download Bibtex

Abstract

The Puck (Mrzezino) hoard and procedures of the Prussian Monarchy towards coin finds. Treasure legislation in the Prussian monarchy shared hoards between the finders and the owners of the ground. This regulation produced archival evidence dating back to the eighteenth century. The large gold hoard, found in what is nowadays Mrzezino in northern Poland in 1795, was reported to Berlin shortly after its discovery. In the beginning, mainly juridical questions were discussed, but in 1798, this moved to the discussion of what to do with the coins and where and to whom they should be sold. The archival reports reveal that the coins were mainly of Anastasius, some of Zeno’s and only a few of Leo, Basiliscus and Theodosius and, as their value was above intrinsic value, they were sold to the royal collection in Berlin as well as to collections in Prussia and Poland.

Go to article

Authors and Affiliations

Peter Ilisch
Download PDF Download RIS Download Bibtex

Abstract

This paper presents and compares microphone calibration methods for the simultaneous calibration of small electret microphones in a wave guide. The microphones are simultaneously calibrated to a reference microphone both in amplitude and phase. The calibration procedure is formulated on the basis of the damped plane wave propagation equation, from which the acoustics field along the wave guide is predicted, using several reference measurements. Different calibration models are presented and the methods were found to be sensitive to the formulation, as well as to the number of free parameters used during the reconstruction of the wave-field. The wave guide model based on five free parameters was found to be the preferred method for this type of calibration procedure.

Go to article

Authors and Affiliations

Péter Tóth
Christophe Schram
Download PDF Download RIS Download Bibtex

Abstract

In some areas of the United States (US), asthma prevalence has reached historically unprecedented highs. Three peer-reviewed studies in New York City found prevalence rates among children from 25% to 39%. That is not true in all places. For example, prevalence in Miami, Florida, was estimated to be only 6-10%. A recent study in major cities in Georgia found only 8.5%. One study in California found asthma prevalence was unrelated to local concentrations of criterion pollutants. In the US, all criterion pollutants, including PM2.5, show a downward trend over the last two decades. These facts argue against any significant influence of criterion pollutants in this crisis.These facts suggest that an unrecognized ambient pollutant may be the cause. One important study in southern California in mid-summer measured pulmonary function in children as it was related to outdoor ozone pollution. They found a negative association; higher levels of ozone were associated with improved respiratory function. We call this a "Paradoxical Ozone Association" (POA). Further evidence for a POA appears in seven other studies in Los Angeles, London, Scotland, and southeastern Canada.One plausible explanation for these observations would be the production of methyl nitrite (MN) as an exhaust product of MTB E in gasoline. Unlike ozone, MN is rapidly destroyed by sunlight. All of the POA studies were done in regions with significant methyl ether in gasoline. This explanation is strengthened by the observation that a POA has not been seen in regions without ether in gasoline.A previous A WMA paper proposed a plausible chemical model predicting that MTBE in gasoline will create MN in the exhaust. MN is highly toxic and closely related alkyl nitrites are known to induce respiratory sensitivity in humans. Funding to measure MN has not been available
Go to article

Authors and Affiliations

Peter M. Joseph
Download PDF Download RIS Download Bibtex

Abstract

Water is a sensitive and limited resource, mainly in intensively used agricultural areas in Austria, where groundwater is used as drinking water as well as for irrigation purposes. In order to guarantee a sustainable use of irrigation water, soil water measurement devices can be used to opti-mise irrigation, which means that controlling the soil water content in the entire root system may prevent water stress due to water deficiency on the one hand, and over wetting on the other hand. Furthermore, losses of nutrients due to leaching can be avoided. Several research studies on that topic were initiated during the last few years. The soil water status on selected fields planted with different crops (onions, carrots, sugar beets, sweet maize, zucchini) was monitored continuously by FDR (Fre-quency Domain Reflectometry) soil water measurement devices. Sensors in different depths measure the plant water uptake in the root zone under standard irrigation practices on different sites and dif-ferent soils, respectively. The deepest sensor is installed to avoid deep percolation caused by over irrigation. By means of these data, irrigation could be regulated based on the actual plant water re-quirements to keep the soil water content within an ideal range for crop development.

Go to article

Authors and Affiliations

Peter Cepuder
Reinhard Nolz
Download PDF Download RIS Download Bibtex

Abstract

The irrigation system control is identified as a complex hierarchical process of stochastic nature, at the head of which the uncertainties, caused by random variations of meteorological factors (climate) and diversion capacity regime from irrigation canals, were laid.

Under such conditions application of the determinate methods for irrigation system control regarding the effectiveness surrenders to the formalistic and empirical methods.

The most appropriate method is the developed by us, method of preventive control.

As a result of retrospective analysis, to each system status, for example, diversion capacity, it is fixed the factors which lead to its changes, for example, rain layer or total evaporation. To every consequence “factor – system status” it is fixed the indicator and it is determined the probability of its exceeding in retrospective series.

The control is in following of such indicator dynamics, forecasting of the most probably changes within system status and adjustment of the water delivery regime to canal reaches with diversion capacity regime from irrigation canals by means of standard preventive graphical chats of water flow control within hydraulic structures and pumping stations.

Use of such control method allows to minimize the uncertainty influence, also it does not require the major modifications in the design and engineering infrastructure.

As an exception can be the measures, directed to the increase of self-regulating qualities of irrigation systems, namely the ability of on-line water volume control, which is regulated in the idle capacities, provided in canal beds or special reservoirs.

The example of such decision in practice is the Kakhovskaya irrigation system in the South of Ukraine. The use factor of water resources on this system reaches 0.85, the technological discharge water does not exceed 7%, the deficit of productive moisture reserve in soil at the end of interirrigation period does not exceed 20% and all these data were obtained under adverse weather conditions.

Go to article

Authors and Affiliations

Peter Kovalenko
Yuri Mikhaylov
Download PDF Download RIS Download Bibtex

Abstract

Since the digitalization of terrestrial television, many countries have discontinued television broadcasting in the UHF band. The freed-up frequencies are now available as digital dividends for mobile and fixed wireless access communication networks (MFCN), particularly for 4G/5G and public safety services in broadband called BBPPDR. Since cable TV still uses the UHF band, leakage from cable TV networks is the most common cause of interference in MFCN networks. Insufficient containment of the radio frequency signals transmitted through a cable system results in cable signal leakage. This article investigates the significance of controlling electromagnetic signal leaks from cable TV networks and how they impact authorized and standardized MFCN networks in the digital dividend bands. The periodic drivetest approach to detect and measure electromagnetic leakage from a cable TV system in the 700 MHz band at a site is detailed. The causes of the detected leaks and offered the appropriate procedure to repair them are also discussed. Additionally, the current measures taken in Hungary to address cable television signal leakage in the digital dividend bands are also discussed and alternative strategies for the adopted test drive approach are proposed.
Go to article

Authors and Affiliations

Hussein Taha
1
Péter Vári
2

  1. Doctoral School of Multidisciplinary Engineering Sciences, Széchenyi István University, Győr, Hungary
  2. Department of Telecommunications, Széchenyi István University, Győr, Hungary
Download PDF Download RIS Download Bibtex

Abstract

Amongst the early variations of the so-called Otto-Adelheid-pennies are coins with five pellets within the church. They exist in two varieties in respect of the distribution of the four letters ODDO in the cross angles. It can be shown that both are from the same unlocalised mint. The number of dies is rather small and that the variety with O-O-D-D precedes O-D-D-O. Issuing must have started soon after 983/984 and probably was ended before c. 993.
Go to article

Authors and Affiliations

Peter Ilisch
1

  1. Westfälische Wilhelms-Universität Münster
Download PDF Download RIS Download Bibtex

Abstract

Amongst the first imported silver coins from western Europe in hoards in the territories of the western Slavs after the decline of silver import from Central Asia are issues anonymous in both respect of ruler and mint which have been in discussion since the early nineteenth century. In research they have been called by various names such as Sachsenpfennige, Hochrandpfennige, Kreuzpfennige (German) or krzyżówki (Polish) and must originate from mint(s) in Eastern Saxony bordering Slavs. They are of importance for the understanding of the use and chronology of coined silver in Slavic lands, especially in Poland and eastern Germany. The example of the Strandby hoard in Denmark, where these occur in a larger number, are well documented and to a larger part are unfragmented, allows us to show that the hitherto used dating (Kilger 2000) is incorrect. All known varieties must have been struck before 983/984 and not up to c. 1000. There is no continuation to younger series with hammered edge appearing since early eleventh century.
Go to article

Authors and Affiliations

Peter Ilisch
1

  1. Westfälische Wilhelms-Universität Münster

This page uses 'cookies'. Learn more