Optimization of Mechanical Properties and Evaluation of Fatigue Behavior of Selective Laser Sintered Polyamide-12 Components.

In this paper, a comprehensive study of the mechanical properties of selective laser sintered polyamide components is presented, for various different process parameters as well as environmental testing conditions. For the optimization of the static and dynamic mechanical load behavior, different process parameters, e.g.

Are vipers prototypic fear-evoking snakes? A cross-cultural comparison of Somalis and Czechs.

Snakes are known as highly fear-evoking animals, eliciting preferential attention and fast detection in humans. We examined the human fear response to snakes in the context of both current and evolutionary experiences, conducting our research in the cradle of humankind, the Horn of Africa. This region is characterized by the frequent occurrence of various snake species, including deadly venomous viperids (adders) and elapids (cobras and mambas).

The bigger the threat, the longer the gaze? A cross-cultural study of Somalis and Czechs.

High fear reaction, preferential attention, or fast detection are only a few of the specific responses which snakes evoke in humans. Previous research has shown that these responses are shared amongst several distinct cultures suggesting the evolutionary origin of the response. However, populations from sub-Saharan Africa have been largely missing in experimental research focused on this issue.

Resurrection of Oxythyrea abigailoides Mikšić, 1978 (Coleoptera: Scarabaeidae: Cetoniinae) based on new morphological, morphometrical and molecular data.

Oxythyrea abigailoides Mikšić, 1978, resurrected species, is removed from synonymy with Oxythyrea dulcis Reitter, 1899 and regarded as a separate species. The differential diagnosis of both species is presented on the basis of clearly different morphological, morphometric and molecular characters. Complete chresonomy to both species is given and known geographical distribution to date is summarized and mapped.

Animals evoking fear in the Cradle of Humankind: snakes, scorpions, and large carnivores.

Theories explain the presence of fears and specific phobias elicited by animals in contemporary WEIRD (Western, educated, industrialized, rich, and democratic) populations by their evolutionary past in Africa. Nevertheless, empirical data about fears of animals in the Cradle of Humankind are still fragmentary. To fill this gap, we examined which local animals are perceived as the most frightening by Somali people, who inhabit a markedly similar environment and the region where humans have evolved.

 (Coleoptera, Scarabaeidae, Melolonthinae), a new species from Somaliland.

Bezděk & Sehnal, , from Somaliland is described and relevant diagnostic characters are illustrated. The new species is compared with the morphologically closely similar Kolbe, 1894 species. An updated checklist and an identification key to northeastern African species are provided.

Static and Dynamic Mechanical Behaviour of Hybrid-PBF-LB/M-Built and Hot Isostatic Pressed Lattice Structures.

We report on a comprehensive study of the mechanical properties of maraging steel body-centred cubic lattice structures fabricated by a hybrid additive manufacturing technology that combines laser powder bed fusion with in situ high-speed milling. As the mechanical properties of additive manufactured components are inferior to, e.g.

Factors influencing carrion communities are only partially consistent with those of deadwood necromass.

Research on decomposer communities has traditionally focused on plant litter or deadwood. Even though carrion forms highly nutrient-rich necromass that enhance ecosystem heterogeneity, the factors influencing saprophytic communities remain largely unknown. For deadwood, experiments have shown that different drivers determine beetles (i.

Do Spiders Ride on the Fear of Scorpions? A Cross-Cultural Eye Tracking Study.

Deep fear of spiders is common in many countries, yet its origin remains unexplained. In this study, we tested a hypothesis based on recent studies suggesting that fear of spiders might stem from a generalized fear of chelicerates or fear of scorpions. To this end, we conducted an eye tracking experiment using a spontaneous gaze preference paradigm, with spiders and scorpions (previously neglected but crucial stimuli) as threatening stimuli and grasshoppers as control stimuli.

A Case-Control Study of Distinguishing Between Stroke Mimics and True Strokes.

This study was conducted with the primary aim to distinguish patients with a true stroke versus a stroke mimic based on clinical features and imaging. We conducted a retrospective case-control study on 116 adult patients who received alteplase (tPA) to treat acute stroke at our hospital. We further analyzed 79 patients with a normal computed tomography angiography (CTA).

Dung-visiting beetle diversity is mainly affected by land use, while community specialization is driven by climate.

Dung beetles are important actors in the self-regulation of ecosystems by driving nutrient cycling, bioturbation, and pest suppression. Urbanization and the sprawl of agricultural areas, however, destroy natural habitats and may threaten dung beetle diversity. In addition, climate change may cause shifts in geographical distribution and community composition.

Bolbaffroides dhofarensis (Coleoptera: Bolboceratidae), a new species from Oman.

Bolbaffroides dhofarensis Krl, Hillert, Mencl Sommer, new species, from Dhofar Governorate in south-western Oman is described. Relevant diagnostic characters (e.g.

Tool Wear and Milling Characteristics for Hybrid Additive Manufacturing Combining Laser Powder Bed Fusion and In Situ High-Speed Milling.

We report on milling and tool wear characteristics of hybrid additive manufacturing comprising laser powder bed fusion and in situ high-speed milling, a particular process in which the cutter mills inside the powder bed without any cooling lubricant being applicable. Flank wear is found to be the dominant wear characteristic with its temporal evolution over utilization period revealing the typical s-shaped dependence. The flank wear land width is measured by microscopy and correlated to the achievable surface roughness of milled 3D-printed parts, showing that for flank wear levels up to 100 μm a superior surface roughness below 3 μm is accessible for hybrid additive manufacturing.

Design Rules for Hybrid Additive Manufacturing Combining Selective Laser Melting and Micromilling.

We report on a comprehensive study to evaluate fundamental properties of a hybrid manufacturing approach, combining selective laser melting and high speed milling, and to characterize typical geometrical features and conclude on a catalogue of design rules. As for any additive manufacturing approach, the understanding of the machine properties and the process behaviour as well as such a selection guide is of upmost importance to foster the implementation of new machining concepts and support design engineers. Geometrical accuracy between digitally designed and physically realized parts made of maraging steel and dimensional limits are analyzed by stripe line projection.

Cation-translocation based isomerism offers a tool for the expansion of compressed helicates.

A series of compressed M[Li313Ti2] (M = Li, Na, K, Rb, Cs) and expanded helicates M4[13Ti2] has been obtained. The helicates Li3[M13Ti2] or M4[13Ti2] with M = Na+, K+, Rb+, or Cs+ adopt the expanded structure in solution. By crystallization the compressed structures M[Li313Ti2] (M = Na, Rb) are obtained.

Carcasses at Fixed Locations Host a Higher Diversity of Necrophilous Beetles.

In contrast to other necromass, such as leaves, deadwood, or dung, the drivers of insect biodiversity on carcasses are still incompletely understood. For vertebrate scavengers, a richer community was shown for randomly placed carcasses, due to lower competition. Here we tested if scavenging beetles similarly show a higher diversity at randomly placed carcasses compared to easily manageable fixed places.

emOiceoptoma/em emtangi/em (Coleoptera: Silphidae: Silphinae), a new species of carrion beetle from eastern China.

A new species, Oiceoptoma tangi Sommer, Růžička, Nishikawa Schneider, new species, from Zhejiang Province, China, is described and illustrated. The new species is closely related to O. subrufum (Lewis, 1888), distributed in Central and North-eastern China, the Korean Peninsula, Far East of Russia and Japan, and to O.

Bolbelasmus (Bolbelasmus) zagrosensis (Coleoptera: Scarabaeoidea: Bolboceratidae), a new species from Iran, along with an updated key to the western Palaearctic species of the subgenus.

Bolbelasmus (Bolbelasmus) zagrosensis Sommer, Hillert, Hrůzová Král, new species, from Iran is described, illustrated and compared with its congeners known from the western Palaearctic region. An updated key to the western Palaearctic species of the nominotypical subgenus is provided. New country record of B.

Pachnoda iskuulka (Coleoptera: Scarabaeidae: Cetoniinae), a new species from Somaliland, including description of its mature larva.

Pachnoda iskuulka Král, Sommer Šípek, new species from the Sanaag region of north-eastern Somaliland is described. The new species is compared with the morphologically similar taxa Pachnoda abyssinica abyssinica Reiche, 1847, P. a.

Characterization and Reduction of In-Use CH Emissions from a Dual Fuel Marine Engine Using Wavelength Modulation Spectroscopy.

In-use exhaust stream CH emissions from two dual fuel marine engines were characterized and strategies for CH reduction were identified and evaluated. For this, a low-cost, portable, wavelength modulation spectroscopy (WMS) system was developed. The performance of the developed WMS sensor was assessed using gas standards and demonstrated on a heavy-duty, diesel pilot ignited, direct-injection natural gas research engine through comparison to a flame ionization detector.

Estimation of inferior-superior vocal fold kinematics from high-speed stereo endoscopic data in vivo.

Despite being an indispensable tool for both researchers and clinicians, traditional endoscopic imaging of the human vocal folds is limited in that it cannot capture their inferior-superior motion. A three-dimensional reconstruction technique using high-speed video imaging of the vocal folds in stereo is explored in an effort to estimate the inferior-superior motion of the medial-most edge of the vocal folds under normal muscle activation in vivo. Traditional stereo-matching algorithms from the field of computer vision are considered and modified to suit the specific challenges of the in vivo application.

Intraparenchymal cyst development after deep brain stimulator placement.

Following deep brain stimulation (DBS) surgery, a variety of potential mechanical or functional complications ranging from perioperative events to hardware malfunction may occur. We present 2 patients who developed a unique complication of cyst formation at the tip of the DBS electrode in the absence of infection. One patient had a unilateral ventral intermediate lead placement for essential tremor, and the other had bilateral subthalamic nucleus (STN) placement for Parkinson's disease.