Safety assessment method on pedestrian crossings near schools

Dużym zagrożeniem dla pieszych jest przekraczanie jezdni. Najczęstszym sposobem próby minimalizacji ryzyka z tym związanego jest stosowanie przejść dla pieszych. Jednak często przejścia nie spełniają warunków, które w pełni gwarantowałyby pieszemu bezpieczeństwo. Dorosły uczestnik ruchu jest w stanie obiektywnie ocenić, czy jest dostatecznie widoczny na przejściu, czy samochód zbliżający się do niego będzie w stanie zahamować. Nie jest to już takie oczywiste w przypadku dzieci, które przecież także, często same, uczestniczą w ruchu drogowym. Dlatego szczególnie ważna jest analiza bezpieczeństwa przejść dla pieszych w pobliżu szkół. Celem artykułu jest przedstawienie metody analizy bezpieczeństwa na przejściach dla pieszych ze znakiem T-27, czyli „Agatką”, który jest montowany na przejściach w pobliżu szkół. Jako poligon badawczy wykorzystano istniejące przejścia dla pieszych na drogach wojewódzkich znajdujących się w województwie pomorskim. W artykule przedstawiono proces budowy bazy danych, wyboru kryteriów oceny oraz dokonano oceny kilku przykładowych przejść dla pieszych.Pedestrian, also called vulnerable road user, is particularly exposed on the risk associated with participation in the traffic. Crossing the road is a big threat for pedestrian. The most common way to minimize this risk is an application of the pedestrian crossings. Pedestrian crossings often do not meet requirements of safety level. Safety on pedestrian crossings depends on many factors, like: traffic congestion, pedestrian congestion, crossing environment, geometry of roads, lighting, adequate labelling. Adult pedestrian is able to assess if he/she is visible enough, or if a car will be able to stop before the crossing. This is not so obvious with the children, who also often participate in traffic without adults. That is why it is very important to analyze the safety of pedestrian crossings near schools. The aim of this article is to present the methods of safety analysis on pedestrian crossings marked with the sign T-27 – so called "Agatka" – near the schools. Existing pedestrian crossings on provincial roads located in Pomorskie voivodeship will be training ground for research. This article presents process of development of a database, selection criteria for the evaluation and evaluation of exemplary of pedestrian crossings

Selected methods of induction motor bearings diagnostics based on the stator current measurement

W artykule zawarto przegląd wybranych metod diagnostyki łożysk silnika indukcyjnego, bazujących na pomiarach prądu zasilającego. Jedno z nowych rozwiązań zostało zaadaptowane przez autorów do stosowanego przez nich systemu diagnostycznego. Wstępne badania potwierdziły zalety tej metody. Diagnostyka silników indukcyjnych, prowadzona zdalnie poprzez pomiar prądu zasilającego, jest atrakcyjna szczególnie przy braku dostępu do silnika. Przedstawiona koncepcja ma szanse na wdrożenie w przemyśle.This paper provides an overview of a few selected solutions of induction motor bearings diagnostics based on current measurements, that have appeared in the literature in recent years. Bearing failure amount is greater than 40% of all engine failures, so their damage-free operation is crucial [1]. Diagnosis of induction motors, carried out remotely by measuring the supply current is convenient and often practical. It could be very useful especially in terms of difficult access to the engine such as mining industries or high voltage engines. Detection of eccentricity and bearings fault, using stator current and stray flux monitoring [2] is described in Section 2. Section 3 introduces the concept of using the Luenberger speed observer for bearings diagnostic purpose [3]. The fourth section shows the stator current and motor efficiency as diagnostic indicators [4]. A new current signal processing solution for bearings diagnostic [6] is described in Section 5. This method using Teager – Kaiser Energy Operator, was applied by the authors to an existing diagnostic system. The results of the preliminary simulation and experimental research showed that this solution gave more precise diagnosis. This experiment was carried out on the engine, with introduced slight damage of the bearings outer race. The presented concept may be implemented in the industry. The authors intend to pursue further studies using this method

Morfologia urediniów i urediniospor grzyba Melampsora larici-epitea Kleb. - groźnego patogena wierzby wiciowej (Salix viminalis L.) w Polsce

Rust (Melampsora spp.) is a damaging disease of willows (Salix spp.), including common osier (S. viminalis L.). So far, the pathogens of this species found in Europe were identified as M. larici-epitea Kleb. or M. ribesii-viminalis Kleb. Moreover, a stem infecting form (SIF), deprived of a sexual stage in its life cycle was reported. The aim of this study was to find out which species of the rust fungi cause disease symptoms on common osier in Poland. The isolates from common osier were compared to the ones originating from its putative hybrids with trembling aspen (Populus tremula L.) and Simon’s poplar (P. simonii Carr.). Fungal isolates were obtained in 2008–2010 from 15 different genotypes of willows, including seven varieties of common osier (4 Swedish and 3 Polish), two landraces of common osier and six putative hybrids with poplars. Fungal isolates originated from three experiment sites, including west (Wielkopolska and Lubuskie) and north-east (Warmia) regions of Poland. To ensure the genetic uniformity, the isolates were derived from single uredinia, obtained from natural infection conditions. In all collected samples the position of uredinia was always hypophyllous. The diameter of uredinia was measured by Sigma Scan Pro software, after inoculation of four standard genotypes, including two common osier and two willow hybrids. The studies proved that the main cause of common osier rust is Melampsora larici-epitea f. typica. All studied isolates, including the ones obtained on putative hybrids, were very similar according to the size of uredinia and the size and morphology of urediniospores. The average size of a uredinium was 1.1 mm diameter and slightly differed between the isolates (from 0.9 to 1.3 mm), depending on willow genotype, the quality of plant material used for artificial inoculations and infection conditions. The average size of a typical urediniospore was 12.4 x 10.5 μm, but the sizes varied from 9.8 to 13.2 μm. Urediniospores from common osier were slightly bigger and more oval (12.5 x 10.4 μm) as compared to spores from the putative hybrids Salix x Populus (12.3 x 10.6 μm), but the differences were statistically insignificant. The spores were ovoid, globoid or angular, evenly echinulated. The size of uredinia, as well as the size and morphology of urediniospores were in full agreement with literature data for M. larici-epitea f. typica