Orchestina pavesii (Simon, 1873), an oonopid spider new to Slovakia (Araneae: Oonopidae)

Representatives of Oonopidae are tiny spiders, usually of a pale colour, with 6 oval eyes. Systematically, they belong to Dysderoidea, which include about 120 genera (CODDINGTON & LEVI 1991), but Oonopidae, alone, include 51 genera and more than 70 species (PLATNICK 1989). They are distributed all over the world, except for Antarctica, but most of the species come from the tropics. In Europe, there are 6 genera of oonopid spiders, represented by about 20 species (PLATNICK 1989). But only 6 species have been known from the Central Europe until recently (NENTWIG 1991). In Slovakia, only 2 species of oonopid spiders, Oonops domesticus Dalmas, 1916 and Triaeris stenaspis Simon, 1891, have been recorded so far (GAJDOS et al. 1999)

Study of surface roughness of machined polymer composite material

The aim of this paper is to evaluate the influence of selected cutting parameters (speed of rotation and feed rate) on the surface topography of drilled WPC material. Objective of the study is to establish dependence of the surface roughness of borehole walls (parameter —average maximum height) on the speed of rotation and feed rate of a drill bit. Technological parameters of experimental drilling were feed rate of 100–300 mm·min−1 and speed of rotation of 2000–6000 rpm.Web of Scienceart. no. 30351

Elevation gradient affects the distribution and host utilisation of Zatypota anomala (Hymenoptera, Ichneumonidae) associated with mesh web weaving spiders (Araneae, Dictynidae)

The spatial distribution of parasitoids is closely linked to the distribution and ecological requirements of their hosts. Several studies have documented changes in the fauna composition of parasitoids in response to elevation, but data on parasitoids associated with spiders are missing. The koinobiont ichneumonid wasp Zatypota anomala is strictly specialised on spiders of the genus Dictyna (Dictynidae) in Europe. We examined the distribution of spiders of the family Dictynidae in forest ecotones in central Europe across a broad elevation gradient (110–1466 m a.s.l.). We checked the spiders for parasitism by Z. anomala. It was most abundant at the mid-elevations (median 712 m a.s.l., range 179–870 m a.s.l.). We identified four dictynid spider species as Z. anomala hosts. These were Dictyna arundinacea, Dictyna uncinata, Nigma flavescens, and Nigma walckenaeri. All four species and the genus Nigma were recorded as hosts for the first time. The parasitoids strongly preferred juvenile instars of their hosts. The body length differed between parasitised Dictyna and Nigma spiders (medians: 1.95 mm and 2.55 mm, respectively). The distribution of Dictyna and Nigma spiders overlapped along the elevation gradient, but parasitism incidence significantly differed between spider genera along the elevation gradient. Nigma was parasitized at lower elevations between 179–254 m a.s.l. and Dictyna at higher elevations between 361–870 m a.s.l. The phenology of Z. anomala is closely tied to the univoltine life strategy of its host spiders. The parasitoid female oviposits in autumn, and its offspring overwinter as larvae on the host, reach adulthood during spring, and pass the summer as an adult

A novel method for detection of covered conductor faults in medium voltage overhead line systems

Although there aremany reasons whymedium voltage (MV) overhead lines with covered conductors (CCs) are used instead of aluminum-conductor steel-reinforced cables, the operation of CCs takes into account a difficult detection of faults, e.g., the contact of a tree branch with a CC. In this paper, we continue with the previous work on an electric voltage-based method enabling the detection of the CC faults; we introduce a new indicator of the faults based on the frequency of peaks in the signal of partial discharges. We mainly demonstrate the fault detection in a real MV distribution system, including a number of fault detectors; a fault is detected in 99.2% of occurrences within a long-term testing, although the cost of the detector is minimized in comparison with other similar fault detectors.Web of Science65155254