Ecological Niche Modeling Approaches to Conservation of Endangered and Threatened Birds in Central and Eastern Europe

Comprehensive biodiversity surveys are unavailable for most Central and Eastern European countries. Although birds in general are well-studied, distributional information in the region is sparse and largely out-of of-date; I used museum specimen locality records and raster GIS data layers summarizing environmental dimensions to produce distributional hypotheses for the 36 threatened and endangered bird species in the region using ecological niche modeling. These ecological niche models were also used to predict likely future (2055) distributional shifts owing to global climate change. The entire suite of distributional information that resulted was used to evaluate strategies for conservation via simple heuristic place-prioritization algorithms based on complementarity and rarity considerations. These analyses identified priority areas in southern and eastern Romania, as well as other areas across the region, as priority targets for conservation action in the region

Per- and Polyfluoroalkyl Substances Mitigation From Contaminated Groundwater Using Halophyte and Cow Bone Biochars

Per- and polyfluoroalkyl substances (PFAS) groundwater contamination is a growing concern for the Brackish Groundwater National Desalination Research Facility. Two of the four wells onsite are contaminated with perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), and perfluorohexane sulfonic acid (PFHxS). The removal of PFAS by adsorption onto powder activated carbon (PAC) is promising, but the production of PAC is energy intensive and expensive. A potential cost-effective alternative to PAC is biochar. This study quantified the capacities of two halophyte biochars, cow bone biochar and PAC to adsorb PFOA, PFOS, and PFHxS from brackish groundwater. The three biochars were ineffective at adsorbing the PFAS compounds at low adsorbent doses (10-100 mg/L) because of their low surface area. Increasing the biochar adsorbent dose to 200, 500, and 1000 mg/L allowed for comparable PFAS absorption by one of the halophyte biochars

Analysis of a Twin Screw Expander for ORC Systems using Computational Fluid Dynamics with a Real Gas Model

With the increase in energy prices and environmental constraints, recovering the energy from low grade waste heat presents an important challenge. The Organic Ranke Cycles (ORCs) are widely used, but there is still need to improve their efficiency (especially for small scale energy production). This paper presents the Computational Fluid Dynamics (CFD) analysis of a twin screw expander which is used for power generation in an ORC system with refrigerant R245fa. The deforming mesh motion is handled by an in-house code which generates a block-structured grid with the help of the solutions of Laplace problems. The properties of refrigerant R245fa are derived from the Augnier Redlich-Kwong cubic equation of state which is incorporated in the computational model. From the results of a CFD analysis, the pressure-volume diagram, mass flow rates and power output for different pressure ratios and different designs were obtained. In order to evaluate the effects of individual clearance gaps on the performance of the expander, time dependent mass flow diagrams for each of them are provided and studied. It can be concluded that the influence of the leakage flows increases with decrease in rotational speed or with the increase in pressure ratio. To avoid losses during the filling, an optimized design of the inlet port is necessary

Effects of Temperature on Sound Production and Auditory Abilities in the Striped Raphael Catfish Platydoras armatulus (Family Doradidae)

Background: Sound production and hearing sensitivity of ectothermic animals are affected by the ambient temperature. This is the first study investigating the influence of temperature on both sound production and on hearing abilities in a fish species, namely the neotropical Striped Raphael catfish Platydoras armatulus. Methodology/Principal Findings: Doradid catfishes produce stridulation sounds by rubbing the pectoral spines in the shoulder girdle and drumming sounds by an elastic spring mechanism which vibrates the swimbladder. Eight fish were acclimated for at least three weeks to 22 degrees, then to 30 degrees and again to 22 degrees C. Sounds were recorded in distress situations when fish were hand-held. The stridulation sounds became shorter at the higher temperature, whereas pulse number, maximum pulse period and sound pressure level did not change with temperature. The dominant frequency increased when the temperature was raised to 30 degrees C and the minimum pulse period became longer when the temperature decreased again. The fundamental frequency of drumming sounds increased at the higher temperature. Using the auditory evoked potential (AEP) recording technique, the hearing thresholds were tested at six different frequencies from 0.1 to 4 kHz. The temporal resolution was determined by analyzing the minimum resolvable click period (0.3-5 ms). The hearing sensitivity was higher at the higher temperature and differences were more pronounced at higher frequencies. In general, latencies of AEPs in response to single clicks became shorter at the higher temperature, whereas temporal resolution in response to double-clicks did not change

Der Einfluss der Temperatur auf die Lautbildung und das Hörvermögen des Liniendornwelses Platydoras armatulus (Familie Doradidae)

Die Lauterzeugung und das Hörvermögen ektothermischer Tiere werden von der Umgebungstemperatur beeinflusst. Die aktuelle Studie hat den Einfluss der Außentemperatur auf die Lautparameter und das Hörvermögen des neotropischen Liniendornwelses Platydoras armatulus untersucht. Welse der Familie Doradidae (Dornwelse) produzieren einerseits Stridulationslaute durch das Reiben der Dornfortsätze der Brustflosse im Schultergürtel und andererseits Trommellaute mit Hilfe des Springapperates, der die Schwimmblase in Vibration versetzt. Die Versuchstiere wurden mindestens drei Wochen zuerst an 22° C akklimiert, dann an 30° C und anschließend wieder an 22° C akklimiert. Die Laute der Welse wurden in Stresssituationen, in denen sie in der Hand gehalten wurden, aufgenommen. Die Stridulationslaute wurden bei höherer Temperatur kürzer, während die Anzahl der Pulse, die kleinste und die größte Pulsperiode, der Schalldruckpegel und die Hauptfrequenz sich nicht mit der Temperatur veränderten. Auf der anderen Seite erhöhte sich die Grundfrequenz und die durchschnittliche Pulsperiode der Trommellaute verkürzte sich mit steigender Temperatur. Mittels der Auditory Evoked Potential (AEP) Recording Methode wurde die Hörempfindlichkeit bei insgesamt sechs verschiedenen Frequenzen zwischen 0.1 bis 4 kHz getestet. Das zeitliche Auflösungsvermögen des Hörvermögens wurde durch die minimale auflösbare Klickperiode (0.3 – 5 ms) bestimmt und die Latenzen der Antwort als Verzögerungen auf den präsentierten Klick gemessen. Das Hörvermögen verbesserte sich zwischen 0.5 und 4 kHz mit steigender Umgebungstemperatur, während das zeitliche Auflösungsvermögen als Antwort auf Doppelklicks nicht von der Temperatur beeinflusst wurde. Die Latenzen der AEPs verkürzte sich in drei von insgesamt vier Peaks bei höherer Temperatur. Diese Daten lassen daraus schließen, dass die Hörempfindlichkeit mit zunehmender Temperatur steigt. Die biologischen Gegebenheiten, die sich auf das Hörvermögen bei unterschiedlichen Temperaturen anders auswirken, können selbst nach langer Akklimierungsperiode nicht kompensiert werden. Da einige Lautparameter ebenfalls temperaturabhängig waren, lautet die Schlussfolgerung, dass die Umgebungstemperatur direkt die akustische Orientierung und die Kommunikation des neotropischen Liniendornwelses P. armatulus beeinflusst.Sound production and hearing sensitivity of ectothermic animals are affected by the ambient temperature. The present study investigates the influence of temperature on sound characteristics and the hearing ability in the neotropical Lined Raphael catfish Platydoras armatulus. Doradid catfishes produce stridulation sounds by rubbing the pectoral spines in the shoulder girdle and drumming sounds by an elastic spring mechanism which vibrates the swimbladder. Fish were acclimated for at least three weeks to 22°, then to 30° and again to 22° C. Sounds were recorded in distress situations when fish were hand-held. The stridulation sounds became shorter at the higher temperature, whereas the pulse number, the minimum and maximum pulse period, the sound pressure level and dominant frequency did not change with temperature. On the other hand, the fundamental frequency increased and the mean pulse period of drumming sounds decreased at the higher temperature in drumming sounds. Using the auditory evoked potential (AEP) recording technique, the hearing thresholds of eight specimens were tested at six different frequencies from 0.1 to 4 kHz. The temporal resolution was determined by analyzing the minimum resolvable click period (0.3 - 5 ms). Auditory sensitivity increased from 0.5 to 4 kHz with rising temperature, whereas temporal resolution in response to double-clicks did not change with temperature. Latencies of AEPs in response to single clicks decreased in three out of four peaks at higher temperature. These data indicate that hearing sensitivity increases with temperature at higher frequencies. Constraints imposed on hearing sensitivity at different temperatures cannot be compensated even by longer acclimation periods. As sound characteristics also change with temperature, it is suggested that the ambient temperature directly affects acoustic orientation and communication in the neotropical catfish P. armatulus

Nonlinear elastic-viscoplastic constitutive equations for aging facial tissues

This paper reports on the initial stages of a project to simulate the nonlinear mechanical behavior of an aging human face. A cross-section of the facial structure is considered to consist of a multilayered composite of tissues with differing mechanical behavior. The constitutive properties of these tissues are incorporated into a finite element model of the three-dimensional facial geometry. Relatively short time (elastic-viscoplastic) behavior is governed by equations previously developed which are consistent with mechanical tests. The long time response is controlled by the aging elastic components of the tissues. An aging function is introduced which, in a simplified manner, captures the observed loss of stiffness of these aging elastic components due to the history of straining as well as other physiological and environmental influences. Calculations have been performed for 30years of exposure to gravitational forces. Progressive gravimetric soft tissue descent is simulated, which is regarded as the main indication of facial aging. Results are presented for the deformations and stress distributions in the layers of the soft tissue