The cold-drought tolerance trade-off in temperate woody plants constrains range size, but not range filling

Interspecific differences in plant species' ranges are shaped by complex mechanistic interactions, which have so far remained largely beyond the reach of comprehensive models and explanations. Previous attempts to find underlying mechanisms by examining physiological tolerances to cold and heat separately have yielded contradictory results. Here we test the hypothesis that, instead of examining single stressors, abiotic stress tolerance syndromes that involve trade-offs between multiple abiotic stressors (namely drought, cold, waterlogging and shade), will provide reliable explanations. We compiled a dataset of actual range size and range filling (the ratio between actual and potential species range) as range metrics for 331 temperate woody plants species from Europe and North America. Tolerance syndromes were expressed as two PCA axes. One axis reflects a drought-cold/waterlogging tolerance trade-off (cold/wet-drought trade-off), the second axis represents a shade tolerance spectrum. Phylogenetic generalized linear mixed models were used to model the range metric vs. tolerance axes relationships using latitude as an additional main effect, and phylogeny and plant functional type as random effects. Actual range scaled negatively with the cold/wet-drought tolerance trade-off axis, mostly independently of latitude and continent. Thus, cold/wet-tolerant species had the largest ranges and drought tolerant species the smallest. The negative sign of the relationship was independent of phylogeny and plant functional type. In contrast, range filling depended on latitude. However, deciduous and evergreen species displayed different distributions of range metrics and tolerance syndromes. No significant relationships with the shade tolerance spectrum were found. Our findings demonstrate that the cold/wet-drought trade-off partly explains interspecific range size differences. However, this trade-off did not explain range filling. We also showed that fundamental adaptations of species also significantly influence range sizes, stress avoidance through the deciduous habit also explained interspecific differences in range size

Theoretical foundations for energy-efficient production of railway rails with improved performance properties

Dependence of plastic deformation resistance of chromiumalloyed rail steels on the thermomechanical parameters of deformation (degree, speed, and temperature of deformation) and chemical composition of the steels under consideration was obtained by hot mechanical tests for torsion and compression. According to the obtained data, an increase in rate and a decrease in deformation temperature cause an increase in resistance to plastic deformation. Effect of relative deformation on resistance to plastic deformation is nonlinear with an expressed maximum at deformation degree of the order of 0.25. Analysis of influence of chemical composition of 76KhF, 76KhSF and 90KhAF rail steels and their resistance to plastic deformation was carried out using methods of multiple regression analysis. It has shown that increasing of content of carbon, manganese, vanadium, nitrogen, sulfur and phosphorus in the actual range of changes in their concentration leads to an increase in their plastic deformation resistance. Mechanism of this effect was revealed. Approximation of the obtained data allowed us to determine interval of changes in deformation resistance when chemical composition varies within the actual range of changes in elements content. Value of specified interval was up to 19 % of the absolute value of deformation resistance. When varying content of chemical elements in the interval specified in state standard for production of railway rails, value of deformation resistance interval was up to 30 %. Checking adequacy of the obtained dependences was performed by oscillographing the stands drives engines of rail mill of JSC “EVRAZ ZSMK” when rolling billets of different chemical composition. This checking made it possible to confirm the revealed patterns.

Enhancement of power efficiency of evaporating-condensing heat exchangers

The aspects of heat transfer in evaporating-condensing heat exchangers conditioning their thermophysical merits and advantages as regards routine heat transferring devices are determined and analyzed. It is shown that implementation of one of these aspects which is transformation of heat flux density in its transferring from “hot” medium to “cold” one by changing the ratio of the lengths of the evaporation and condensation zones of evaporating-condensing heat transferring elements (positioning of tube plate separating the channels with heat exchanging media) allows studying optimization of the said ratio in respect to getting the minimal thermal and aerodynamic resistances of evaporating-condensing heat exchangers. Thus, the concerned work on one of the parts of such study is aimed to derive the correlations for optimal ratio of evaporation and condensation zones in gas-to-gas heat exchangers based on vertical transversely finned tubular thermosiphons to spend the minimal power required to pump heat-exchanging media under the specified conditions of heat transfer. As an objective function of optimization the dimensionless ratio of transferred heat flux to the sum of the powers provided to pump the heat-exchanging media through the heat-exchanger channels is accepted. This ratio is called a factor of heat exchanger power efficiency. In the concerned study the functional dependence of dimensionless power efficiency factor of evaporating-condensing heat exchanger upon dimensionless ratio of the lengths of evaporation and condensation zones is derived. The performed extremum research of the dependence revealed that it has an extremum for an actual range of the determining parameters and this extremum is the maximum. The study resulted in an equation of optimal relationship between the zone lengths (the heights of the channels occupied by flowing heat-exchanging media) that corresponds to the maximal factor of power efficiency.

GreenMaps: a Tool for Addressing the Wallacean Shortfall in the Global Distribution of Plants

The exponential growth of species occurrence data can facilitate dynamic biodiversity analyses. However, raw biodiversity data alone should not be used indiscriminately due to inherent sampling biases, impediments that contribute to Wallacean shortfall (i.e. the paucity of species’ geographic information). It has been suggested that Wallacean shortfall is a common phenomenon across taxa, however, there is no global assessment geared toward overcoming this impediment for plants, despite the fundamental role of plants in ecosystem stability, food security and biodiversity conservation. Here, I present GreenMaps, a new tool that will permit a rapid initial assessment of the Wallacean shortfall for plants by building base maps of species’ predicted distributions upon which citizen science participation could contribute to spatial validation of the actual range occupied by species. The initial stages of GreenMaps have now been accomplished, providing a massive dataset of modeled range maps for over 194,000 vascular plant species. This will make it the largest and only global assessment of geographic distributions for plant species at scales relevant to research and conservation. Ultimately, GreenMaps will interface with a mobile application to enable volunteers from any region of the world to validate predicted species distributions to be used for the generation of new and improved global map of plant distributions.

Performance of liquid–liquid hydrocyclone (LLHC) for treating produced water from surfactant flooding produced water

Purpose The purpose of this study is to investigate the performance of the fabricated liquid–liquid hydrocyclone (LLHC) with dimensions similar to those of one of the Malaysian oilfields with the presence of an anionic surfactant, S672. The effect of salinity and initial oil concentration were also investigated following the actual range concentration. Design/methodology/approach The current control system’s pressure drop ratio (PDR) does not necessarily lead to an efficient LLHC. Therefore, rather than using the PDR, the efficiency of the LLHC was analyzed by comparing the concentration of oil in the effluents with the concentration of oil at the feed of the LLHC. An LLHC test rig was developed at Centre of Enhanced Oil Recovery, Universiti Teknologi PETRONAS. Emulsions were prepared by mixing the brines, S672 and oil by using Ultra Turrax ultrasonic mixer. The emulsion was pumped into the LLHC at different feed flowrate and split ratio. The brines concentration, initial oil concentration and S672 concentration were also varied in this study. Samples were taken at the underflow of the LLHC and the oil in water concentration analysis was done for the samples using TD-500D equipment. Findings It was found that the efficiency of oil removal decreased with an increase in S672 concentration but increased with the increase in salinity and initial oil concentration. Originality/value The optimum feed flowrate for the LLHC of 45 mm diameter and length of 1,125 mm with the presence of S672 surfactant was found to be 40 L/min with a split ratio of 14%. This study can be used as a guidance for future optimization of the LLHC in the presence of the surfactant.

Media i geopolityki późnej nowoczesności. Naturalizacja i nostalgia jako horyzont wspólnot wyobrażonych.

Contemporary media organize exchange by means of Internet, bridges, convergences, double addressing… The result is overproduction of hybrids with mixed weak ontology and inclusion of digital augments into living space. Implementation of technology makes people face a change and requires domestication of innovations and subsequent products of the language of mathematics. Adaptation is slower than the technological change. What counts is an actual range of transformations and cultural content. It is about proxemic schemes characteristic of numerical media and schemes according to which media space is perceived, presented, understood and created. Experiencing a place and recording human reactions to a digital place lead to geopoetics. Virtual geographies and patterns of home and route… repeated by media result in questions about imagined communities and content which is able to integrate them nowadays. Two strategies of being-in-the-world dominate in late modernity: naturalization and nostalgia. In the context of them people still live in the horizon of home and of encountering the others, and a global culture still remains a question of time.

Investigation on Range Anxiety and Safety Buffer of Battery Electric Vehicle Drivers

Drivers tend to have more range anxiety compared with driving traditional fuel vehicles if they are driving battery electric vehicle (BEV) with a long trip. Range anxiety could potentially have negative effect on driver’s emotions and behaviors. In order to understand this behavior and improve the related safety issues, this paper will focus on BEV drivers’ study in China. A survey on BEV drivers’ actual range anxiety as well as the effect of range anxiety on drivers’ behaviors is conducted in this research. Levels of feelings and attitudes of the interviewees are quantized with Likert scales using mathematical tools of the relationship. Safety buffer is defined as a measurement of the period given range anxiety starting to significantly intervene in driver’s operation. The research reveals the proportional quotative relationship between BEV drivers’ safety buffer and the mileage of trip. Factors, including driving experience, satisfactory level of recharge accessibility, and resistibility to emotions, are found to be significant contributing factors to influence the perceived range anxiety level of BEV drivers. This research will provide implications to the future study on the interface design of BEV.

Projektarbejde og akademisk IT-skoling

Artiklen redegør for en kortlægning i 2015 af de studerendes brug af IT-værktøjer i forbindelse med projektarbejde på Roskilde Universitet. På grundlag af en spørgeskemaundersøgelse samt interviews med 12 studerende forklares anvendelsen af IT-værktøjer i projektarbejdets forskellige faser. Som ramme for undersøgelsen diskuteres begrebet ”akademisk digital skoling”, og der trækkes linjer til internationale undersøgelser, som synes at bekræfte, at studerende reelt bruger et fåtal af IT-værktøjer, og at disse i hovedsagen ikke er udviklet til akademiske formål. Undersøgelsens resultater sammenholdes med det udvalg af IT-værktøjer, universitetet stiller til rådighed for ansatte og studerende. Afslutningsvis diskuteres de mulige årsager til tingenes tilstand, samt hvordan det vil være muligt at hæve niveauet af den akademiske digitale skoling. This paper introduces a 2015 survey of Roskilde University students' use of IT-tools in project work. Based on a survey and qualitative interviews, the use of IT-tools in various phases of project work is illustrated and discussed. The concept "academic digital competence" is introduced as a framework for the study, and parallels are drawn to international research confirming that students tend to use only a limited number of IT-tools, the majority of which were not developed for academic purposes. The survey results are compared to the actual range of IT-tools that the university offers freely to faculty and students. In conclusion, the authors discuss the reasons for the state of affairs and how to strengthen academic digital competences.