ALBERT

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The aim of our study was to determine how body mass affects home range size in carnivorous marsupials (dasyurids) and whether those species living in desert environments require relatively larger areas than their mesic counterparts. The movement patterns of two sympatric species of desert dasyurids (body mass 16 and 105 g) were investigated via radio-telemetry in southwestern Queensland and compared with published records for other Australian dasyurids. Both species monitored occupied stable home ranges. For all dasyurids, home range size scaled with body mass with a coefficient of 〉 1.2, almost twice that for metabolic rate. Generally, males occupied larger home ranges than females, even after accounting for the size dimorphism common in dasyurids. Of the three environmental variables tested, primary productivity and habitat, a categorical variable based on the 500 mm rainfall isopleth, further improved model performance demonstrating that arid species generally occupy larger home ranges. Similar patterns were still present in the dataset after correcting for phylogeny. Consequently, the trend towards relatively larger home ranges with decreasing habitat productivity can be attributed to environmental factors and was not a result of taxonomic affiliation. We therefore conclude that alternative avenues to reduce energy requirements on an individual and population level (i.e. torpor, basking and population density) do not fully compensate for the low resource availability of deserts demanding an increase in home range size.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The Vitruvian Man of Leonardo da Vinci is one of the most famous and most studied drawings over the world as well as one of the most reproduced ones, e.g. in coins (Italian euros), space suit patches (NASA), books and movies. The aim of the present work is to discuss the Vitruvian Man as a figurative representation of the Leonardo’s scientific method. Our analysis is based on scientific elements both present in the drawing and provided by Leonardo in his approach to this drawing. Our thesis is that the square symbolizes the measurable physical world and that the man inscribed within the square refers to the physics measurement process based on the operational definition of quantities, including the measurement unit system and the quantities conversion factors. Therefore, the measurement process is fundamental for the Leonardo’s approach to the scientific knowledge, albeit, the drawing also suggests that this latter does not correspond with the true knowledge. The circle, which has a different center with respect to the square, symbolizes the truth, to which the man inscribed in the square yearns, without ever achieving it, the truth being reachable only by the man inscribed within the circle.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Eco-friendly poly(butylenes succinate) (PBS)/bamboo carbon lubricant composites were designed and prepared by hot pressing. The hardness and wear properties of the designed PBS composites were studied. The results showed that the hardness of PBS composite containing 50% of the bamboo carbon lubricant increased by more than 150%. The composite material with 50% bamboo carbon lubricant had the lowest wear rate, which was up to 72% lower than that of pure PBS. The wear of neat PBS was harsh with severe cut and even partly melted points appearing on the worn surface. The wear modes of PBS bamboo carbon composite were abrasive wear and fatigue wear. While the worn surface of PBS bamboo carbon lubricant composite was with slight exfoliation, its wear mode was slight adhesive wear. It is concluded that the addition of bamboo carbon lubricant can broaden the application range of eco-friendly polymer of PBS in the engineering field of anti-wear requirements. 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Animals can evoke a wide range of emotions helping us to choose a quick and appropriate reaction towards them: approach or avoidance in general. This work has focused on disgust evoked by amphibians in humans as well as perceived beauty. Due to the high morphological variability of recent amphibian taxa, we examined humans’ cognitive categorisation of 101 amphibian photos and the effect of stimuli characteristics on disgust evaluation or beauty perception of individual groups/species. We also explored how respondents’ characteristics, e.g. gender, age and disgust sensitivity (DS-R) influence the disgust and beauty evaluation of picture stimuli on a 7-point Likert scale. The scores of disgust and beauty evaluation were strongly negatively correlated, representing the opposite ends of a single axis, further referred to as the index of preference. The most preferred amphibians belonged to anurans, whereas the least preferred ones were mostly worm-like, legless and small-eyed caecilians. Additional analyses of morphologically diverse anurans showed that species with a round body shape, short forelegs, small eyes, warts, pink and grey colouration, or dark and dull colouration were perceived as disgusting or ugly. The effect of gender and age were only marginal; however, people with higher disgust sensitivity rated amphibians as more disgusting and less beautiful, which might support the hypothesis of a possible disgust involvement in animal fears and phobias. This topic has implications not only for the nature conservation decisions of globally endangered amphibians but also for understanding the evolution of disgust and its generalisation to harmless animals.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In the present work, dynamical aspects of boundary layer flow of hydromagnetic fluid (suspended with microorganisms) are investigated near the stagnation region over a stretchable heated permeable sheet. Viscosity is taken as a linear function of temperature where the flow field accommodates diffusion processes due to temperature and concentration gradients (Soret/Dufour numbers). A system of partial differential equations is set up for the mathematical description of the related bio-physical phenomenon. Unit free conversions and analysis of symmetry are implemented to obtain nonlinear dimensional free differential equations setup which can be solved numerically via the Runge–Kutta–Fehlberg scheme. Results in the form of pictorial and tabulation representation reveal that velocity profile increases when viscosity is a function of temperature difference, but the velocity profile influences the fluid temperature in the opposite direction.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This article focuses on an experimental analysis of the performance of a mobile manipulator (MM) executing generalized point-to-point tasks. This leads to surpass constraints, depending on the mechanical structure of the robot, on the environment and on the task to be performed. The robotic system is made up of a robotic arm mounted on wheeled mobile robot. Polynomial trajectory planning method is applied to generate trajectories, assigned to a real robot. The experimentations deal with motion coordination, control and task execution problems. Different ways to execute generated trajectories on a real MM (RobuTER/ULM) are tested, and several parameters influencing the movement of the system are examined. 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Software testing is one of the most labor-intensive and crucial phases of the software development life cycle. It accounts for about 50–60% of the total cost of a project and requires a substantial amount of effort to ensure that the quality of the software is not compromised. Hence, optimizing the process of software testing has been of paramount importance in the IT industry. In recent times, there has been a significant shift toward software test automation to ensure the quality of the software while minimizing the cost and effort. This study proposes a statistical model analyzing the various factors that affect the testing cost, quality and effort by studying the behavioral pattern of professionals employed in the field of testing. The paper studies the factors, project duration, Software Complexity (SC), testing tools and automated test suite generation, while contrasting it with the overall software test automation, with the aim of finding a measure of how much automation affects the cost, quality and effort in practice. The results indicated that automation accounted for a variation of about 25% in each of the factors: cost, quality and effort much more than factors such as project duration, SC and testing tool . Further, the analysis indicated that the effect of SC on cost and effort was extremely low. This suggests that automation improved the quality while reducing the cost and effort irrespective of the complexity of the software being developed. 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Dispersal, movement leading to gene flow, is a fundamental but costly life history trait. The use of indirect social information may help mitigate these costs, yet we often know little about the proximate sources of such information, and how dispersers and residents may differ in their information use. Terrestrial molluscs, which have a high cost of movement and obligatorily leave information potentially exploitable by conspecifics during movement (through mucus trails), are a good model to investigate links between dispersal costs and information use. We studied whether dispersers and residents differed in their trail-following propensity in the snail 〈em〉Cornu aspersum〈/em〉. Dispersers followed mucus trails more frequently than expected by chance, contrary to non-dispersers. Trail-following by dispersers may reduce dispersal costs by reducing energy expenditure and helping snails find existing habitat or resource patches. Finally, we point that ignoring the potential for collective dispersal provided by trail-following may hinder our understanding of the demographic and genetic consequences of dispersal.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Software maintenance is an important software quality attribute. Many factors affect software maintenance, one of them being code cloning. Code clones are segments of code that are very similar. Software stability tends to measure the unchanged code elements. The objective of this paper is to find whether stability metrics can be used as an indicator of code structural similarity. I perform an empirical study to find the relationship between code similarity and stability at the class level. I also conduct clustering to classify stability and similarity metrics into different related groups. Finally, I perform principal component analysis to determine which class stability metrics have the strongest relationship with class similarity. In addition, I built a prediction model to predict class similarity using class stability metrics. The results show that the four investigated stability metrics have a significant relationship with similarity; however, the class stability metric (CSM) has the strongest correlation with code similarity. The clustering results also reveal that classes with high stability tend to have high similarity. In addition, I found that the CSM and class instability metric (CII) can both reveal 74.023% of class similarity. I conclude that stability metrics can be used as a good indicator of class similarity.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The looming threat of fossil fuel depletion coupled with its disastrous environmental effects has compelled researchers to look into alternative sources of energy that can provide two-way solution such as sustainability and environment protection. Biodiesel which is renewable in nature has emerged as a potential alternate to diesel that can be used in unmodified or little modified diesel engine. Biodiesel is commonly prepared by two-step esterification–transesterification chemical reactions. Biodiesel-fuelled engines are not as efficient as diesel-fuelled engines. Therefore, diesel engine systems must be modified suitably to get the desired power, efficiency with reduced fuel consumption and exhaust emissions to meet the customers’ requirements and strict emissions norms set by the legislations. To cater the above said demands, current research is an effort to make an efficient biodiesel engine with lower emissions by suitably modifying the piston that augments turbulence. The induced turbulence produced by modified piston makes a better quality of air–fuel mixture which in turn improved thermal efficiency and BSFC by 1.46% and 5%, respectively. The HC emissions were reduced by 6.7%, while CO reduced slightly. Expectedly, the formation of NOx was found to be increased from 5 to 7.4%.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Leachate is a very hazardous liquid, and it is considered as one of the major concerns regarding landfills. Landfill leachate is the result of water penetration from solid waste and oxidation of waste and parcels. The undeveloped landfills allow the leachate to cross easily through the soil. This can affect the soil engineering properties such as shear strength, soil compressibility and chemical properties (absorption and retention of heavy metals). This research has investigated the influence of the leachate resulted from municipal solid waste in Ardabil with different percentages and densities on the parameters of shear strength and compressibility of the soil around the site. Also, a test, which is called leachate column test, was carried out to study the environmental properties of the soil (the rate of pollutant absorption and pollutants transmission). The results indicate that with increasing leachate percentage, the internal friction angle decreases. Moreover, soil cohesion is significantly reduced and the compressibility results indicate that soil compressibility will also increase. Increasing the concentration of leachate reduces the cohesion and increases the internal friction angle as well as the compressibility, and changes the volumetric pressure of the soil. Also, the results of leachate test, which shows the rate of pollutants absorption and transmission in the sample placed in the chamber, indicate that the concentration of nickel and zing goes up by increasing the volume of the passing leachate.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉 Superalloys are generally considered to be difficult to machinability. In recent attempts to facilitate their machinability, minimum quantity lubrication (MQL) has been used due to its positive influence on cutting tool life, the environment and human health. This study focused on the tool life, wear behavior and surface roughness in the milling of nickel-based superalloy Waspaloy. Uncoated carbide tools, PVD (TiAlN)-coated tools and CVD (TiCN + Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 + TiN)-coated tools were used. Experiments were performed with different cooling methods which included dry, wet and MQL. SEM and EDX were used for tool wear behavior and mechanism analyses. A portable measuring instrument and a 3D optical profilometer were employed for surface roughness analyses. Results obtained from the tests showed that during the milling of the Waspaloy, adhesion and abrasion were effective wear mechanisms for the cutting tools. The main wear behaviors were flank wear, crater wear and BUE (built up edge). In addition to these results, reduction in the tool wear, the wet machining and machining with the MQL system provided improvement at the rates of 37.54% and 29.01%, respectively, when compared to the dry machining. 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In the present paper, the potential of the progressive collapse of a reinforced concrete frame of a seven-storey building was evaluated by comparing the capacity curve and the M–N diagram of the beams. The advantage of this approach is that it captures the exact resistance mechanisms occurring during the progressive collapse of the structure such as flexural action, compressive arch action and catenary action. Furthermore, the overlapping of the capacity curves and the M–N diagram were proved to be an efficient tool to optimize the design of the resistance of structures to collapse. The modelling technique based on the Applied Element Method was validated by an experimental test. Consequently, numerical studies were performed according to General Services Administration guidelines using different scenarios implying the removal of one or two adjacent columns from the ground level. Additionally, the slabs were considered in the structural analysis and flexural action was identified as the main mechanism of action against total structural failure. 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, the distribution static compensator model based on the bond graph (BG) domain is presented. The methodology is applied to reactive power compensation in distribution systems where a traditional phase lock loop for sensing the AC grid frequency is not needed. The control law is developed using the inverse BG model, which is extracted using the bi-causality concept. In this way, it is possible to perform the distribution system analysis completely in the BG domain. This means that the graphical model is inverted by obtaining the open-loop control law structure, and then the close loop is formulated. The balanced and unbalance conditions are analyzed, generating a control structure that is robust and efficient. The efficacy of the proposed methodology is shown through: partial and complete system simulations in MATLAB/Simulink〈sup〉®〈/sup〉 (MATLAB r2015b, Natick, Massachusetts, 01760, USA), as well as experimental laboratory tests. Such tests use: the rapid control prototyping concept and the real-time simulator Opal-RT Technologies〈sup〉®〈/sup〉 (Montreal, QC, Canada). 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Brain tumor is considered as a fatal disease with low survival rate and has the highest cost of care per patient. This article proposes a computer-assisted system for the recognition of brain tumor image through magnetic resonance imaging based on the monogenic signal analysis. From different monogenic components, textural descriptors are obtained using completed local binary pattern and gray-level co-occurrence matrix. In the pre-processing step, various filtering for noise removal and contrast enhancement techniques are implemented. Local phase, energy and orientation components originated from the monogenic signal analysis method are used for textural feature extraction. Fisher score-based filter approach for feature selection is then employed to derive the discriminating feature set. Finally, the acquired optimal feature set is classified using the support vector machine classifier. Two benchmark MR image datasets, e-health laboratory and Harvard medical laboratory, have been used to validate the system performance. Overall detection accuracy obtained was above 99%. The experimental results demonstrate the effectiveness of the proposed approach and the potential to assist the medical experts in enhancing the detection rate. Furthermore, the presented approach delivers superior performance in brain tumor image recognition as compared to existing techniques.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This paper provides an historical perspective of the involvement of Prof. J.C. Legros in microgravity research during aircraft parabolic flights. Prof. Legros conducted 27 experiments during 33 campaign of microgravity research organised by the European Space Agency. Nearly all fields of fluid physics were investigated in microgravity by this indefatigable scientist. This paper gives a non-exhaustive summary of some experiments conducted by Prof. Legros during these 33 campaigns.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Erasure codes, in the recent past, have emerged as an alternative to data replication-based systems for storing big data. Efficient choice of code and data nodes from the numerous available storage nodes is the key to the performance of any storage system. This paper presents the Storage Node Allocation Problem for selecting the suitable set of nodes for holding data and code blocks by representing the storage systems as a complete bipartite graph. Additionally, the paper formally proves that the problem is NP-hard and proposes approximate solutions using greedy, ant colony optimization and clustering-based methods. The solutions accomplish efficient choice of storage nodes by utilizing parameters like bandwidth availability, distance between the nodes, computational load and disk space availability.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Natural enemies are one of the main mortality factors in bees and wasps attacking either immature stages or adults of their hosts. Dipterans of the genus 〈em〉Physocephala〈/em〉 (Diptera: Conopidae) are parasitoids that attack adult bees during their field activities, and the parasitoid larvae develop inside the host abdomen. However, little is known about the biology of these natural enemies and their interactions with their solitary bee hosts. This study is aimed at analyzing attacks by conopid flies in one of their hosts, the solitary bee species 〈em〉Centris analis〈/em〉 (Apidae: Centridini), and the consequences in the nesting behavior of this bee species. Higher incidences of parasitism occurred during the hot/wet season, and seven fly species attacking 〈em〉C. analis〈/em〉 were identified. Of the fifty-six females observed during their nesting activities, seven of them were parasitized. These females showed alterations in their nesting behavior, depositing extra oil on the plug of finished nests and building plugs in empty cavities. The behavioral changes observed in these females began during larval stage L1 of the parasitoid. In the last stages of parasitoid development (L3 PUP and pupa), the bees ceased their flight activities and entered cavities at the nesting site, remaining there until death.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Polyploidisation—and, additionally, agmatoploidy (concerted fission of chromosomes) in some plant groups—have significantly contributed to the diversification of alpine plant species. Both processes have driven the diversification of 〈em〉Luzula〈/em〉 sect. 〈em〉Luzula〈/em〉, leading to a number of different karyotypes, rendering it one of the most intricate plant groups in the Alps. For the Eastern Alps eight species with six karyotypes were reported, but their distribution is insufficiently known. A herbarium revision of 1044 specimens revealed that 〈em〉L. alpina〈/em〉, 〈em〉L. campestris〈/em〉, 〈em〉L. exspectata〈/em〉, 〈em〉L. multiflora〈/em〉 and 〈em〉L. sudetica〈/em〉 are widespread across the Eastern Alps; 〈em〉L. exspectata〈/em〉 is thus new for the Northern Alps and new for Germany, France and possibly Croatia. 〈em〉Luzula divulgata〈/em〉 is distributed in the easternmost Alps and adjacent areas, with only a few indications for the western Eastern Alps. 〈em〉Luzula divulgatiformis〈/em〉 is new for the Alps where it was recorded in the Southern Alps and southerly adjacent areas. 〈em〉Luzula campestris〈/em〉, 〈em〉L. divulgata〈/em〉 and 〈em〉L. divulgatiformis〈/em〉 are distributed from lowlands to the montane belt, 〈em〉L. alpina, L. exspectata〈/em〉 and 〈em〉L. sudetica〈/em〉 are high-elevation species and 〈em〉L. multiflora〈/em〉 occurs from lowlands to the alpine belt. Additionally, we estimated genome size (GS) and karyotypes for 20 populations and revealed four karyotypes corresponding to three ploidy levels. The GS of diploid 〈em〉L. exspectata〈/em〉 and 〈em〉L. sudetica〈/em〉 was 0.83 pg DNA, tetraploid 〈em〉L. alpina〈/em〉 had a double (1.63 pg) and hexaploid 〈em〉L. multiflora〈/em〉 a triple (2.48 pg) GS. Our study underlines the importance of large-scale herbarium revisions of intricate taxa, combined with cytological methods, even in well-studied mountain areas such as the Alps and poses new hypotheses regarding the evolution of this polyploid–agmatoploid group.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Gliomas are the most infiltrative and life-threatening brain tumors with exceptionally quick development. Gliomas segmentation using computer-aided diagnosis is a challenging task, due to irregular shape and diffused boundaries of tumor with the surrounding area. Magnetic resonance imaging (MRI) is the most widely used method for imaging structures of interest in human brain. In this study, a deep learning-based method that uses different modalities of MRI is presented for the segmentation of brain tumor. The proposed hybrid convolutional neural network architecture uses patch-based approach and takes both local and contextual information into account, while predicting output label. The proposed network deals with over-fitting problem by utilizing dropout regularizer alongside batch normalization, whereas data imbalance problem is dealt with by using two-phase training procedure. The proposed method contains a preprocessing step, in which images are normalized and bias field corrected, a feed-forward pass through a CNN and a post-processing step, which is used to remove small false positives around the skull portion. The proposed method is validated on BRATS 2013 dataset, where it achieves scores of 0.86, 0.86 and 0.91 in terms of dice score, sensitivity and specificity for whole tumor region, improving results compared to the state-of-the-art techniques. 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Although several researches have reported potential gender differences in adaptations during microgravity, the musculoskeletal alterations of different genders are still under debate. Besides, there were few researches which involved recovery phase after reloading. In the present study, we investigated the musculoskeletal alterations of rats hindlimb via tail-suspension in both genders, and analyzed the serum sex hormone at the same time. Thirty-two Sprague Dawley rats were equally divided by gender into four groups randomly: control of male (CONM), tail-suspension of male (TSM), control of female (CONF) and tail-suspension of female (TSF). The experiment consisted two phases, which were 21 days of tail suspension phase and 21 days’ reloading phase, and parameters of bone, muscle and serum were tested at the end point of each phase. The results indicated that during tail suspension phase, male rats showed a greater and earlier bone loss and microstructure deterioration compared with females, but they could maintain muscle strength much better. In addition, during reloading phase, male rats showed a slower bone recovery and some parameters could not recover until the end, while loss in muscle mass and strength in both genders could recover to control level.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The regimes of joint flows of the evaporating liquid and vapor-gas mixture in a 3D rectangular channel are studied with the help of a partially invariant solution for the convection equations. The effects of thermodiffusion and diffusive thermal conductivity in the gas–vapor phase are additionally taken into account in the governing equations and under interface conditions. A numerical simulation of the 3D fluid flows is carried out for the liquid–gas system like ethanol–nitrogen and HFE-7100–nitrogen under microgravity conditions. The influence of the thermal load, liquid layer thickness and heat-transfer liquid type on the structure of the fluid flows and evaporation characteristics is investigated. The solution allows one to describe the formation of longitudinal thermocapillary rolls observed in the experiments. The evaporative mass flow rate depends essentially on the thermophysical properties of the working liquid. Spatial size and a shape of thermal patterns are determined by the applied thermal load and they can be varied with the change in the liquid layer thickness. Topological structure of the flows (double or quadruple vortex composition) is defined by the combined influence of the thermocapillary and convective mechanisms and phase transition effects. The results discussed in the paper provide motivation for the development of a classification of the 3D flow regimes similar to the Napolitano’s classification for 2D flows.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Traditional reamer blade with double-row cutters and middle channel structure frequently encounters the cuttings deposition and balling when reaming the soft and sticky formation which is easy to hydration and collapsing. Balling causes were analyzed from the view of the cuttings’ properties and the hydraulic characteristics of the traditional reamer blade. Based on the analysis results, a new anti-balling reamer blade technology was presented to address this problem. Evaluations on the cutting force and working life of the new blade were conducted by comparison with the pilot polycrystalline diamond compact (PDC) bit. The theoretic working life of the new blade was about twice longer than that of pilot PDC bit. The hydrodynamic analysis results indicated that the disappearing of low-pressure region and turbulence combined with the lower differential pressure of the annulus fluid can significantly prevent the new reamer blade from cuttings deposition and balling.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Solubility parameters of supercritical water and methanol were probed by using molecular dynamics simulation. The computed solubility parameters agree well with the theoretical values for different temperatures and pressures within the supercritical region. The results show that the solubility parameter decreases with increasing temperature and increases with increasing the pressure. The polarity of the system increases at higher temperatures; therefore, the degree of molecular aggregation increases. Raising the pressure of the system reduces the degree of aggregation between molecules and increases the solubility parameter of the system.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The foremost difficulties related to the use of biodiesel in CI engine are lower BTE and insignificant smoke emissions. These difficulties related to using biodiesel can be resolved by inducting gaseous fuels simultaneously along with primary fuel in CI engine. This paper confers the effect of the compression ratio on the engine on the performance, combustion, and emission characteristics of Niger seed (〈em〉Guizotia abyssinica〈/em〉) oil methyl ester blend (B20) with simultaneous injection of hydrogen (gaseous fuel) at different flow rates. The studies were carried out on a variable-compression-ratio single-cylinder 4-stroke CI engine at 1500 rpm with three different compression ratios of 16, 17.5, and 18.5 and at three different hydrogen flow rates of 5 lpm, 10 lpm, and 15 lpm. The injection of hydrogen notably increased the brake thermal efficiency (BTE) with a significant reduction in brake-specific fuel consumption (BSFC). The combustion characteristics cylinder pressure (CP), net heat release rate (NHRR), and rate of pressure rise (RoPR) also increased drastically. Also, the emission of CO, UHC, and smoke opacity were reduced significantly with spike in NOx emissions. The comparable trends were followed at all the three compression ratios, and the CR 18.5 has shown improved results at a flow rate of 15 lpm. At 15 lpm and CR 18.5, the BTE, CP, NHRR, RoPR, and NOx values were increased by 7.3%, 7.68%, 12.36%, 21.08%, and 56.8%, respectively. Further, the BSFC, CO, UHC, and smoke opacity were reduced by 9.15%, 84.95%, 69.9%, and 59.78% respectively.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Fenton-like processes have been widely studied in recent years and are considered promising for organic wastewater treatment. Enhancement of wastewater treatment performance involves the development of economical and environmental aspects of the process. The present work aims to investigate the degradation and mineralization of an organic model compound, namely patent blue V (PBV) in aqueous solution. The process adopted uses the Fenton-like mode enhanced by UV light, using a low amount of reagent at natural pH, which was close to neutral. Some key parameters including UV light, H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉 dosage, catalyst amount and initial dye concentration in the homogeneous Fenton-like processes were discussed. The complete degradation of 10 mg/L of PBV was obtained in 1 h with low reagent concentrations (0.98 mg/L and 39.1 mg/L of Fe〈sup〉3+〈/sup〉 and H〈sub〉2〈/sub〉O〈sub〉2〈/sub〉, respectively) at natural pH (6.4). The mineralization was justified through the determination of sulfates, nitrates and calcium formed during oxidation. The reaction obeys the pseudo-first-order and kinetic constants, namely the apparent rate constant, the half-life time and the catalytic efficiency, strongly depend on the catalyst concentration. The reutilization of the generated sludge in the photo-Fenton-like process was discussed. However, in spite of the decrease in the degradation efficiency, the possibility of recycling the catalyst Fe〈sup〉3+〈/sup〉 as sludge Fe(OH)〈sub〉3〈/sub〉 makes the process photo-Fenton-like, cheaper and environment friendly.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The NiO–YSZ/LSCF–YSZ dual-layer hollow fiber membrane receives increasing attention which is due liable to quick changes in properties during co-extrusion followed by the co-sintering method. The effect of mixed bore liquid of water + ethanol +〈em〉 n〈/em〉-methyl-2-pyrrolidone and co-sintering temperature on physical and chemical characteristics of the obtained membrane was systematically explored in this study. Here, the characterization of the membrane was inspected using scanning electron microscope–energy-dispersive X-ray, three-point bending, mercury porosimetry, X-ray diffraction and nitrogen tightness tests as well as the oxygen permeation test. Results indicated that membrane prepared using 100% water as a bore liquid produced a sandwich structure. On the contrary, by employing 40:10:50% of water/ethanol/NMP as a mixed bore liquid and sintering for 8 h at 1300 °C, an open-channel structure in the microstructure gives a good porosity as tested using mercury porosimetry, mechanical properties and nitrogen permeability with no secondary phases. In addition, the co-sintering effect was examined by increasing temperature to 1400 and 1500 °C. However, an impurity phase of LaZr〈sub〉2〈/sub〉O〈sub〉7〈/sub〉 was formed which is due to the chemical reaction of La and Sr into YSZ structure. Oxygen permeate concentration through the dual-layer membrane was found to be slightly different as compared to the single-layer hollow fiber membrane. The results further suggest that the outer layer should be tighter and thinner to enhance the oxygen ion diffusion.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Intermediate oxides are synthesized by heating fresh lead dioxide obtained from commercial positive plates of lead-acid batteries. These oxides are soaked in sulfuric acid with 1.28 s g under stirring for 1 h. The obtained powders are analyzed using X-ray diffraction and chemical analysis. The samples are discharged with a cathodic current of 1 mA in sulfuric acid with 1.28 s g, and the capacity is determined. It is found that lead dioxide obtained from PbO〈sub〉1.55〈/sub〉 is more active than the fresh sample. It shows an increase in capacity of 17%. This is due to the increase in the quantity of structural water as given by the chemical and thermal analyses.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Sand casting is the one of the oldest fabrication techniques, which has a number of important technological challenges with respect to improving productivity and quality of the castings. It is essential for the foundries to reduce or eliminate the casting defects if they need to survive in this highly competitive global market. This review arises from a strong industrial demand for understanding the physical and process parameters to improve the quality and soundness of the sand-cast products. The present article primarily reviews the investigations done by researchers on the usability of locally available silica sands and clays for casting both ferrous and non-ferrous alloys. The paper highlights the application of artificial intelligence techniques in predicting the sand mould quality and further optimizing the casting process parameters. This article also analyses the potentials and feasibility of three-dimensional printing in sand casting process. Further, the role of different additives on sand mould composition and different trace elements or inoculants on mechanical properties and microstructure of sand casting has been discussed. Finally, elaborations have been made about various types of hybrid sand casting processes along with metal matrix composites.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉A novel three-dimensional inverse method based on the time-accurate solution of Navier–Stokes equations for axial compressor design is proposed in this work. The main novelty lies in the derivation of an inverse design boundary condition established on the conservation of Riemann invariant in order to directly design the blade surface. Specifically, a dynamic mesh technique is employed to update the grids and reduce the computational costs. In addition, some restrictions are imposed on the blade surface movement in order to avoid unrealistic airfoil profiles and guarantee computational robustness. Two redesign procedures are presented, including shock wave strength restrain for the NASA Rotor 37 stage and integrated controlled diffusion airfoil concept design for the Stage 35. Results indicate that this novel inverse method is effective for detailed axial compressor design.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Spontaneous imbibition and displacement are important mechanisms in water flooding. This paper is aimed to evaluate the performance of water imbibition and injection in tight sandstone oil reservoir. Imbibition tests were first done to assess potential contributions to displacement and oil recovery. Then, a subsequent water injection at constant pressure was conducted in cores with permeability less than 0.1 mD and larger than 0.1 mD to explore the extent to which oil can be displaced and to evaluate fluid flow behavior. Finally, water injection at constant velocity was implemented to simulate displacement under reservoir condition and to analyze flow characters during injection. Results showed that water imbibition enhanced recovery more significant in cores with permeability less than 0.1 mD than that in cores with permeability larger than 0.1 mD. The recovery obtained was 19.2–26.7% and 6.7–7.6%, respectively. The subsequent water injection at constant pressure enhanced recovery further from 6.7–7.6% to 35.2–37.7% in cores with permeability larger than 0.1 mD. However, it did not make sense in cores with permeability less than 0.1 mD. There were a narrow area for oil/water co-flow and a sharp decrease in oil permeability at the initial stage. Meanwhile, the recovery during water injection at constant velocity was 57.7% and 42.9%, respectively. It presented high injection pressure in the upstream, and the quasi-threshold pressure gradient reached 80–200 MPa/m, which was hard to implement in reservoir. The injection pressure increased with the decrease in permeability. It also reveals that dominant channels exist and may lead to early water breakthrough which is negative for recovery enhancement.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉A new method of synthesis was developed for the preparation of sorbent basic bismuth nitrate [Bi〈sub〉6〈/sub〉O〈sub〉5〈/sub〉(OH)〈sub〉3〈/sub〉](NO〈sub〉3〈/sub〉)〈sub〉5〈/sub〉·2H〈sub〉2〈/sub〉O (BBN-EtOH). This electrochemical method includes electrodeposition from an acidic Bi(III) solution in 96% ethanol at a constant current density of 150.0 mA cm〈sup〉–2〈/sup〉. Final product was obtained by thermal treatment at 200 °C. Characterization of BBN-EtOH was conducted by employing XRD, FTIR, SEM–EDX as well as BET, and its pI was also determined. The analysis showed that the material obtained is pure [Bi〈sub〉6〈/sub〉O〈sub〉5〈/sub〉(OH)〈sub〉3〈/sub〉](NO〈sub〉3〈/sub〉)〈sub〉5〈/sub〉·2H〈sub〉2〈/sub〉O. Morphologically, it is composed of aggregates which were formed of several smaller particles of various shapes and sizes, some smaller than 100 nm. Electrochemically synthesized sorbent (BBN-EtOH) was used for the removal of the textile dye Reactive Blue 19 (RB19) from deionized water and model solution of river water, and it showed considerably superior sorption performance compared to other inorganic sorbents synthesized by conventional methods reported in the literature. Kinetic study suggests that the sorption process is both under reaction and diffusion control. Equilibrium of the sorption process was attained in several minutes, i.e., the sorption process is very fast. The sorption equilibrium data were well interpreted by the Langmuir, Sips and Brouers–Sotolongo isotherm. The maximum sorption performance was achieved at pH 2.0, and according to the Langmuir isotherm, it is 1344.99 mg g〈sup〉–1〈/sup〉.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this study, naturally heated clay (NHC) was complexed with synthesized ionic liquid (1-ethyl-3-methyl imidazolium bromide solution (EMIB)) to form NHC/EMIB composite. The effectiveness of NHC/EMIB composite in comparison with naturally heated clay (NHC) as an eco-friendly adsorbent for dephenolation of petroleum effluent was investigated. The adsorbents were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. Batch mode experiments were conducted to ascertain the effect of process variables on adsorption. Removal efficiencies of 81.70% and 91.7% were obtained for NHC and NHC/EMIB composite, respectively, at 25 min, 308 K, pH 4.0 and 150 µm. The linear and nonlinear isotherm data fitted best to the Langmuir model for both adsorbent, while the linear and nonlinear kinetic data fitted best to pseudo-second-order and pseudo-first-order models for both adsorbents. The estimated average thermodynamic parameters (Δ〈em〉G〈/em〉〈sup〉0〈/sup〉 = − 9.653 kJ/mol, Δ〈em〉H〈/em〉〈sup〉0〈/sup〉 = –28.295 kJ/mol and Δ〈em〉S〈/em〉〈sup〉0〈/sup〉 = –46.395 kJ/mol) revealed the feasibility, exothermic nature and spontaneity, respectively, of the studied adsorption system.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, the influence of natural cavities on the propagation of hydraulic fractures is investigated using the phase field method. The deflection behaviour of a fracture during its propagation is firstly verified against published experimental data. Then, a sensitivity analysis on the mechanical behaviour of fracture propagation near a cavity is conducted. The fracture deflection is quantified in terms of the deviation distance and deflection point. The influence of the Young’s modulus ratio between the cavity and rock mass (〈em〉E〈/em〉〈sub〉r〈/sub〉= 〈em〉E〈/em〉〈sub〉cave〈/sub〉/〈em〉E〈/em〉〈sub〉rock〈/sub〉), the differential stress (〈em〉S〈/em〉〈sub〉d〈/sub〉= 〈em〉S〈/em〉〈sub〉〈em〉x〈/em〉〈/sub〉 − 〈em〉S〈/em〉〈sub〉〈em〉y〈/em〉〈/sub〉) and the relative spatial position of the fracture and cavity (〈em〉l〈/em〉〈sub〉r〈/sub〉) on the propagation trajectory are considered. Simulation results show that with the decrease in 〈em〉E〈/em〉〈sub〉r〈/sub〉, crack path deviation becomes more prominent. With the increase in 〈em〉S〈/em〉〈sub〉d〈/sub〉, hydraulic fractures tend to propagate along the direction of maximum horizontal geostress. As 〈em〉l〈/em〉〈sub〉r〈/sub〉 varies, the deflection of the hydraulic fracture can be classified into three regimes: (1) the deflection is negligible; (2) the hydraulic fracture deflects and approaches the natural cavity, but does not connect with it; (3) the hydraulic fracture deflects and connects with the natural cavity. The results could be used as guidance for field design of stimulation scheme in carbonate oil/gas reservoirs.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉With the increasing of drilling depth, the working conditions of the drilling engineering are becoming more complicated. When drilling in the complex well structure, there are many new problems or challenges such as low rate of penetration (ROP), serious stick–slip phenomenon, or high risk of downhole tools failure. The most critical factor in solving these new challenges is improving rock breaking efficiency. Considering this, this paper proposed a new oscillator based on the positive displacement motor. Combining with new complex drilling conditions, the new structure was designed. The mathematical models were presented, including the working mechanism of the new design with its structure parameters. Furthermore, the theoretical models of dynamics under new conditions were analyzed, including the new bottom hole assembly. Based on this, we can get the vibration displacement, velocity, and the system vibration spectrum at different drill string positions. Compared with the results of a numerical example, the lab test was carried out. The two important parameters of vibration frequency and impact forces were compared with the theoretical results, which verified the correctness of the theoretical model and the accuracy of the solution method. Moreover, field experiments were also tested to verify the results, and the field experimental data showed that the new design could increase ROP obviously. The method and conclusions of the research can provide a new reference for the new downhole technology of enhancing the ROP or improving the rock breaking efficiency in complex well structure.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Deep saline aquifers are perhaps one of the most ubiquitous sites available for CO〈sub〉2〈/sub〉 sequestration. In this study, a compositional reservoir simulator was used to evaluate the effects of various CO〈sub〉2〈/sub〉 trapping mechanisms in a saline aquifer which includes structural, solubility and mineral trapping. CO〈sub〉2〈/sub〉 was injected at a rate of 4000 m〈sup〉3〈/sup〉/day at the bottom of the aquifer for 50 years. The results indicate that structural trapping dominated for initial 3 years, after which the maximum gas saturation and pressure was reached. During solubility trapping, the gas saturation decreased by more than 70% of the maximum saturation. Mineral trapping decreased saturation further by another 10%. In another approach, the effect of wastewater injection following injection of CO〈sub〉2〈/sub〉 was evaluated. The numerical simulations show reduction in both the amount of mobile CO〈sub〉2〈/sub〉 and its upward migration. Among the different trapping mechanisms, solubility trapping is found to be the most vital one. Multivariate analysis and optimization of the responses, viz. average gas saturation and average pressure rise, were carried out using response surface methodology. Optimized results were obtained for efficient CO〈sub〉2〈/sub〉 sequestration with lesser mobile CO〈sub〉2〈/sub〉 and pressure rise at lower values of injection rate (1000 m〈sup〉3〈/sup〉/day), injection time (50 years), vertical-to-horizontal permeability ratio, 〈em〉K〈/em〉〈sub〉v〈/sub〉/〈em〉K〈/em〉〈sub〉h〈/sub〉 (0.016), and residual gas saturation (0.4).〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This article presents quantitative assessment of drag models based on their effect on hydrodynamics of a circulating fluidized bed (CFB). Three-dimensional full-loop computational fluid dynamics simulation using Euler granular multiphase model is carried out. Six drag models (EMMS, Gibilaro, Gidaspow, Schiller–Naumann, Syamlal–O’Brien and Wen–Yu) were employed, and simulated results of time-averaged solid volume fraction, solid axial velocity and static pressure are compared with the experimental data. Furthermore, a quantitative analysis is carried out using statistical parameters and parity plots. It was concluded that EMMS model is the most suitable model for simulation of a CFB as it is the only model capable of predicting heterogeneity of the bed, and simulation results agree well with the experimental data.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The scratch resistance and wear behavior at relatively high normal loads of binary (TiN, CrN) and ternary (Al〈sub〉0.50〈/sub〉Ti〈sub〉0.50〈/sub〉N, Al〈sub〉0.68〈/sub〉Cr〈sub〉0.32〈/sub〉N) coatings were comparatively investigated. Scratch test results showed that based on the adhesive strength the coatings can be ranked thus: CrN 〉 TiN 〉 Al〈sub〉0.68〈/sub〉Cr〈sub〉0.32〈/sub〉N 〉 Al〈sub〉0.50〈/sub〉Ti〈sub〉0.50〈/sub〉N. The binary coatings were found to possess superior adhesion strength mainly exhibiting a tensile cracking failure mechanism. In contrast, the ternary coatings failed more severely by through-thickness cracking with spallation. The ternary coatings exhibited an average of 68, 67 and 55% improvement in the wear resistance at 15, 20 and 25 N normal loads, respectively, over the binary coatings. Abrasive and oxidation wear were the main wear mechanisms of the binary coatings. The formation of protective tribo-oxide layers is associated with the improved wear resistance behavior of the ternary coatings. High surface roughness due to large amount of surface defects coupled with low plastic deformation resistance and high Al content are reasons for low wear resistance of Al〈sub〉0.68〈/sub〉Cr〈sub〉0.32〈/sub〉N in comparison with Al〈sub〉0.50〈/sub〉Ti〈sub〉0.50〈/sub〉N coating. 〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We present a novel approach to represent ecological systems using reaction networks, and show how a particular framework called chemical organization theory (COT) sheds new light on the longstanding complexity–stability debate. Namely, COT provides a novel conceptual landscape plenty of analytic tools to explore the interplay between structure and stability of ecological systems. Given a large set of species and their interactions, COT identifies, in a computationally feasible way, each and every sub-collection of species that is closed and self-maintaining. These sub-collections, called organizations, correspond to the groups of species that can survive together (co-exist) in the long-term. Thus, the set of organizations contains all the stable regimes that can possibly happen in the dynamics of the ecological system. From here, we propose to conceive the notion of stability from the properties of the organizations, and thus apply the vast knowledge on the stability of reaction networks to the complexity–stability debate. As an example of the potential of COT to introduce new mathematical tools, we show that the set of organizations can be equipped with suitable joint and meet operators, and that for certain ecological systems the organizational structure is a non-boolean lattice, providing in this way an unexpected connection between logico-algebraic structures, popular in the foundations of quantum theory, and ecology.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The complex agonistic repertoire between male lobster cockroaches (〈em〉Nauphoeta cinerea〈/em〉) makes this species an excellent model for aggression studies. During the establishment of dominance hierarchies, 3-hydroxy-2-butanone (3H-2B) functions as a suppression pheromone, keeping the rivals in a submissive state. In the present study, we evaluated the release of 3H-2B by dominant individuals across four different time phases within the 24-h photoperiod, i.e., early scotophase (ES), late scotophase (LS), early photophase (EP), and late photophase (LP). For each time phase, we collected volatile pheromones during a 60-min first-encounter fight to measure the level of released 3H-2B. Subsequently, the amount of 3H-2B remaining in the sternal glands of dominant and subordinate individuals was measured and compared to socially naïve male controls. Release of 3H-2B was relatively high during ES or LP first-encounter fights, compared to LS or EP encounters. The attack duration and aggressive posture intensity in dominant males were positively correlated with the amount of 3H-2B release in all four phases. A similar statistical distribution was found between the amount of 3H-2B released by dominant males and the amount of 3H-2B in the sternal glands of naïve male sternal during LS, EP, and LP. However, during ES, the statistical distribution of 3H-2B released by the dominant was significantly greater than the distribution of 3H-2B content in socially naïve male sternal glands. The observed phase-dependence of 3H-2B release might be due to variations in 3H-2B biosynthesis or the scotophase-specific behavior of naïve males, wherein an aggressive posture is spontaneously adopted with concomitant 3H-2B release.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Resource niche partitioning mediates the coexistence of similar species by reducing the chance of competitive encounters. For co-occurring species that share an ephemeral resource, contrasting activity in space and time may facilitate their persistence. Burying beetles (Silphidae: 〈em〉Nicrophorus〈/em〉) depend entirely on small vertebrate carcasses to reproduce. Given the unpredictability of this resource, and its value to congeners and other scavenger species, burying beetles likely endure intense competition to secure a carcass. Here, contrasting spatial and temporal niche patterns are explored as resource allocation strategies among five sympatric species of burying beetles (〈em〉N. americanus〈/em〉, 〈em〉N. marginatus〈/em〉, 〈em〉N. pustulatus〈/em〉, 〈em〉N. orbicollis〈/em〉, and 〈em〉N. tomentosus〈/em〉). Specifically, the space-use and daily activity patterns are measured, at a fine scale, across species pairs to extrapolate contrasting niche-use patterns within a nicrophorine-rich grassland community in North-Central Oklahoma, USA. The results of this study reveal an important interplay between space-use and daily temporal activity in mediating the scramble competition associated with carrion resources. Where spatial or temporal overlap between burying beetle species is high, direct competition is mediated along an alternative niche dimension. For instance, 〈em〉N. americanus〈/em〉 and 〈em〉N. orbicollis〈/em〉, a species dyad thought to be in direct competition, do overlap temporally but were found to have segregated space-use patterns. Our findings provide key insights into the competitive interactions within a necrophilous community and further inform our broader understanding of the spatial and temporal resource dimensions that drive the ecological niche.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Wildlife populations can respond to changes in climate conditions by either adapting or moving to areas with preferred climate regimes. We studied nesting responses of two bird species, western bluebird (〈em〉Sialia mexicana〈/em〉) and ash-throated flycatcher (〈em〉Myiarchus cinerascens〈/em〉), to changing climate conditions (i.e., rising temperatures and increased drought stress) over 21 years in northern New Mexico. We used data from 1649 nests to assess whether the two species responded to changing climate conditions through phenological shifts in breeding time or shifts in nesting elevation. We also examined changes in reproductive output (i.e., clutch size). Our data show that western bluebirds significantly increased nesting elevation over a 19-year period by approximately 5 m per year. Mean spring temperature was the best predictor of western bluebird nesting elevation. Higher nesting elevations were not correlated with hatch dates or clutch sizes in western bluebirds, suggesting that nesting at higher elevations does not affect breeding time or reproductive output. We did not observe significant changes in nesting elevation or breeding dates in ash-throated flycatchers. Nesting higher in elevation may allow western bluebirds to cope with the increased temperatures and droughts. However, this climate niche conservatism may pose a risk for the conservation of the species if climate change and habitat loss continue to occur. The lack of significant changes detected in nesting elevation, breeding dates, and reproductive output in ash-throated flycatchers suggests a higher tolerance for changing environmental conditions in this species. This is consistent with the population increases reported for flycatchers in areas experiencing dramatic climate changes.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Climate refugia are locations where plants are able to survive periods of regionally adverse climate. Such refugia may affect evolutionary processes and the maintenance of biodiversity. Numerous refugia have been identified in the context of Quaternary climate oscillations. With climate warming, there is an increasing need to apply insights from the past to characterize potential future refugia. Mountainous regions, due to the provision of spatially heterogeneous habitats, may contain high biodiversity, particularly important during climate oscillations. Here, we highlight the importance of mountaintops as climate refugia, using the example of high-mountain oaks which are distributed on the ranges of the Himalaya–Hengduan Mountains, and at high elevations in tropical rainforests. The occurrences of cold-adapted high-mountain oaks on mountaintops amidst tropical rainforest indicate that such locations are and will be climate refugia as global warming continues. We examine factors that predict the occurrence of future climate refugia on mountaintops using recognized historical refugia. Future research is needed to elucidate the fine-scale processes and particular geographic locations that buffer species against the rapidly changing climate to guide biodiversity conservation efforts under global warming scenarios.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The impacts of climate change on alpine summit floras have been widely investigated. However, only few studies included alpine grasslands and generally concluded that snowbeds, with a long snow cover duration and a short growing season, and windy ridges, with a short snow cover duration and strong winter frosts, are the most sensitive alpine grasslands. However, these habitats were mostly investigated in different regions, where local factors (e.g. nitrogen deposition, grazing) can co-vary with climate changes, potentially obscuring differences between habitats. Here, we focused on the Zermatt region (Swiss Alps) to investigate the impacts of climate change on snowbeds and windy ridges. Forty-three exhaustive historical plant inventories on windy ridges (acidophilic or basophilic) and 31 inventories in snowbeds (typical or wet) were repeated in quasi-permanent plots after approximately 23 years. Historical and recent records were compared with the Simpson index, Bray–Curtis dissimilarity, a PCA, ecological indicator values and the frequency and cover changes of species. There was a general increase in α-diversity and a decrease in β-diversity (homogenisation). Most of the new species in the plots were generalists from surrounding grasslands. The plant composition tended to be more thermophilous on acidophilic windy ridges and in typical snowbeds. The flora of acidophilic windy ridges became more similar to that of basophilic windy ridges and more eutrophic. We interpreted this as possibly arising from fertilisation by the aeolian dust deposition coming from the expanding glacial moraine in the valley. In snowbeds, the species indicated increasingly drier conditions, especially in wet snowbeds. Warming climate induces lower snowfall and earlier snowmelt, leading to a shorter snow cover duration. Hence, wet snowbeds are certainly among the most threatened plant communities by climate change in the Alps.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Leaf shape variations and developmental instability were examined for the first time in natural populations of 〈em〉Prunus avium〈/em〉 (L.) L. in the central Balkan region (Bosnia and Herzegovina) at different elevational points, from 230 to 1177 m. above sea level. Geometric morphometric tools were applied to assess the variability of leaf shapes and sizes, while a fluctuating asymmetry leaf index was used as a measure of leaf developmental instability. According to the results of canonical variate analysis for the symmetric component of shape variation and hierarchical analysis of variance for centroid size, the studied populations could be partially differentiated into three groups. The co-variation between leaf form (shape and size) and climate variables was significant, estimated by two-block partial least square analysis. Climate variables (the sum of precipitation in May and the De Martonne aridity index) mostly influenced leaf shape and size. A population situated at the highest elevation had the highest value for fluctuating asymmetry leaf index, which was an indication of developmental instability. High natural variability and interpopulation differences were observed for all studied leaf traits (leaf shape, centroid size, fluctuating asymmetry leaf index, leaf area, leaf length and width, petiole length). For well-known traditional morphometric measures (leaf area, leaf length, leaf width, and petiole length) in accordance with previous studies, intrapopulation variability was greater than interpopulation variability. For centroid size and the fluctuating asymmetry leaf index (measures used in geometric morphometrics) variability was higher among populations than within them. This indicates that geometric morphometrics could give new insights into infra-specific variability.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Microgravity and vacuum are two main environments in outer space. In the microgravity environment, vibration is a typical phenomenon, and it will induce a reciprocating sliding contact between a journal and a bearing in a clearance joint. In vacuum environment, the adhesion effects are severe, and the friction forces are much higher than the ground environment. Nanoscale textures can reduce the contact area and trap the wear particles, which are beneficial to the friction reduction. Most of the current studies focus on the single-pass sliding contact. Actually, considering the roughness of the contact surfaces, a multi-asperity tip should be more reasonable. In this paper, vibration induced reciprocating sliding contacts between nanoscale multi-asperity tips and a textured surface are investigated using a multiscale method, and the material is FCC copper. Six rigid tips are modelled with different cylindrical asperities and slid on the textured surface. Corresponding to the tips, the average friction forces are compared, and the effects of the tip radii are analyzed. The total average friction forces of the textured surface are compared with the case of a smooth surface, and the mechanism of the friction reduction is discussed. The results showed that the total average friction forces decrease as the increase of the asperity radii, and the textured surface can reduce friction forces effectively compared with the smooth surface. This work could contribute to reducing friction by designing the tip and the textured surface in vibration induced reciprocating sliding contacts under microgravity, which will be beneficial to prolong the life of components on the spacecraft.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In the aftermath of the modern science world scientists are still searching for some kind of ontological and epistemological common ground. In this paper I try to show that we, by the aid of Michael Polanyi’s concepts of knowledge, of personal as well as objective knowledge, and his descriptions of the tacit dimensions in the process of knowing, can take some substantial steps toward a better understanding of the contemporary scientific conduct.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Parasitoid researchers have generally thought that the body size of the mother parasitoid does not affect the fitness performance of the progeny during the immature stage, as long as the progeny develop in the same environment. We reveal for the first time that this is not true for the parasitoid 〈em〉Echthrodelphax fairchildii〈/em〉 (Hymenoptera: Dryinidae), which is parasitic on planthoppers. Large females ensured an increased survival rate for their progeny during the immature stage and a large body size at adult emergence. Maternal body size differentially affected the body sizes and survival rates of male and female progeny. Small females did not produce female progeny, and the survival rate of the female progeny increased more steeply with increasing maternal body size than that of the male progeny. Meanwhile, the body size of male progeny increased more steeply with increasing maternal body size. The influence of maternal body size on progeny survival to adult emergence has never been reported in insects before. In addition, large females were more likely to lay female eggs, suggesting that females control the sex ratio of progeny in response to their own body size.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Analysis of three different equations of state suitable for describing fluids near the thermodynamic critical point is performed. Numerical simulation of the piston effect (adiabatic heating) with the use of the equations of state is carried out. The range of temperature distances to the critical point in which the calculated time of the piston effect is equal to the analytical time is defined. The reasons of discrepancy between the calculated and analytical times of the piston effect beyond the range defined is discussed.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Supersonic mixing layers exist extensively in supersonic engineering applications. The rapid mixing of fuel and oxidant at short distances is of great importance, but makes it difficult to develop efficient propulsion systems. The plasma synthetic jet (PSJ) is regarded as a promising high-speed flow control technique. The characteristics of mixing enhancement achieved using a pulsed PSJ were investigated via experiments. Results showed that the PSJ is an effective method for mixing enhancement. Nanoparticle-based planar laser scattering (NPLS) was used to obtain flow structures in three directions. The velocity fields near the PSJ actuator orifice were measured by particle image velocimetry (PIV). Indexes of the fractal dimension and mixing layer thickness were applied to estimate the effect of the PSJ actuator on the supersonic mixing layers. The large-scale vortex structures induced by the pulsed PSJ in the supersonic mixing layers were successfully captured by NPLS. The effect of the PSJ on the supersonic mixing layers was remarkable. The mixing layer thickness under perturbation was larger than that under no perturbation in the downstream. The distribution of the fractal dimension suggests that perturbation of the PSJ cannot improve the fractal dimension values of the fully developed supersonic mixing layers.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉To enhance the bonding properties between ramie fiber and epoxy resin, the ramie fiber was modified using nano-silica grafting. Hydrophilic nano-silica treated with water-soluble sodium dodecyl sulfate (SDS) and organic silane coupling agents was grafted onto the surface of ramie fiber. The surface roughness of the fibers was considerably increased after grafting. The nano-silica particles on the fiber surface enhanced the mechanical and thermal properties of the fiber-epoxy composite plates. Based on an analysis of contact angle measurements and a water absorption study, it was determined that the hydrophilicity of the treated fiber was weakened.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this study, a linear stability analysis is performed for both monotonic and oscillatory modes within a horizontal polymer solution layer, which solely the solvent evaporates into air. The approach is based on general thermodynamic principles and also on the physics of the gas phase and its interactions with the liquid phase. Due to evaporation, the solvent mass fraction changes and cooling occurs at the liquid-gas interface. This can trigger solutal and thermal Rayleigh-Bénard-Marangoni instabilities in the system. For the monotonic mode, the effects of composition dependent diffusion coefficient and dynamic viscosity on the onset of Rayleigh-Bénard-Marangoni convection are studied. Moreover, the effect of different total heights of the liquid-gas system on the behavior of convection onset is considered. The results show that a variable diffusion coefficient and a variable viscosity can notably change the onset of instability for a polyisobutylene (PIB)/toluene solution. Our model for the monotonic mode is also satisfactorily compared with an experimental study. For the oscillatory mode, where the relaxation time is also composition dependent, we observe that very thin layers will be susceptible to an oscillatory instability when drying occurs in the system. Finally, an approximate model is derived exploiting the fact that the solutal Marangoni is by far the most dominant instability mechanism here. A negligible difference with respect to the full model confirms the predominance of the solutal Marangoni mechanism.〈/p〉

Beschreibung: 〈h3〉抽象〈/h3〉 〈span〉 〈h3〉目 的〈/h3〉 〈p〉在采用统计法估测非饱和渗透系数的过程中, 探 讨水-土特征曲线分段的不同方法和不同数量对 估测结果的影响。〈/p〉 〈/span〉 〈span〉 〈h3〉创新点〈/h3〉 〈p〉比较在体积含水量区间和土吸力区间分割水-土特 征曲线对估测非饱和渗透系数的影响; 最终建议 在土吸力区间分割水-土特征曲线。〈/p〉 〈/span〉 〈span〉 〈h3〉方 法〈/h3〉 〈p〉采用现有模型和数学公式, 对比不同类型土质 (单 峰和双峰水-土特征曲线) 估测和实验测量的非饱 和渗透系数。〈/p〉 〈/span〉 〈span〉 〈h3〉结论〈/h3〉 〈p〉1. 传统的在体积含水量区间分割水-土特征曲线会 造成对低吸力区域的非饱和渗透系数的估测不 够精确。 2. 综合比较单峰和双峰的水-土特征曲线 及 2 种不同分割水-土特征曲线的方法, 发现在分 段大于 40 片时, 估测结果非常接近实验结果。 因此, 在采用统计法估测土体的非饱和渗透系数 时, 建议在土吸力区间对水-土特征曲线进行分 割, 且分割数量应该大于40。〈/p〉 〈/span〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉There are many unresolved issues in Reynolds-averaged Navier-Stokes (RANS) calculations of marine propeller performance, especially in the treatment of complex flow phenomena such as boundary-layer development, scale effects, and tip and hub vortices. The particular focus of this study was to apply three scale-resolving simulation (SRS) methods, i.e. dynamic large eddy simulation (DLES), delayed detached-eddy simulation (DDES), and stress-blended eddy simulation (SBES), to improve the prediction of flow characteristics. Firstly, the effectiveness of the SRS methods was verified by comparing numerical results with experimental data. The external performance of rotating machinery is determined by internal flow structures. Particle image velocimetry (PIV) measurement is established as a visualization tool to analyze the wake evolution of a scaled propeller by velocity and vorticity contours in a specified cross-section plane. We found that SRS methods, especially the SBES model, performed well in predicting characteristic parameters and capturing flow field information via quantitative and qualitative analyses. The ability to accurately predict flow characteristics can make computational tools more effective in meeting the needs of modern propeller design and analysis.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉A non-rectangular frame panel usually contains an asymmetrical cross-bracing system with interrupted diagonals, leading to a more complicated buckling behavior than a symmetrical bracing system with continuous diagonals. There have been many studies of the stability theory of symmetrical cross-bracing systems, but few related to non-symmetrical systems. In this study, we analyzed elastic out-of-plane buckling of a general non-symmetrical cross-bracing system with a discontinuous diagonal. The discontinuous and continuous diagonals have different material and geometrical properties, and are not intersected at their mid-spans. A characteristic equation is presented to compute the critical loading of a non-symmetrical cross-bracing system when the supporting diagonal is under either compression or tension. The results show that the characteristic equation of a non-symmetrical bracing system can be transformed into a form the same as that of a geometrically mono-symmetrical system. To facilitate design applications, direct closed-form empirical equations of effective length factor are established for a general non-symmetrical cross-bracing case. The validity of the proposed empirical equations was verified by comparing predicted and theoretical results, and those from a stiffness approach.〈/p〉

Beschreibung: 〈h3〉抽象〈/h3〉 〈span〉 〈h3〉目 的〈/h3〉 〈p〉建立弹性地基参数的修正 Bayes 分析模型, 并获 得地基参数的变尺度优化结果。〈/p〉 〈/span〉 〈span〉 〈h3〉创新点〈/h3〉 〈p〉推求地基参数的变尺度梯度优化方法, 建立地基 参数的修正 Bayes 探索分析模型。〈/p〉 〈/span〉 〈span〉 〈h3〉方法〈/h3〉 〈p〉建立修正 Bayes 目标函数及弹性地基参数的修正 Bayes 探索分析模型, 并利用变尺度梯度搜索方 法进行参数的优化迭代计算。〈/p〉 〈/span〉 〈span〉 〈h3〉结论〈/h3〉 〈p〉地基参数的变尺度梯度搜索分析模型在优化过程 中能够稳定地收敛于地基参数的真值 (图 2)。 变尺度梯度优化理论能够适时地修正空间矩阵 尺度以产生新的搜索方向, 并有效地优化修正 Bayes 目标函数。〈/p〉 〈/span〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This study provides new insights into pore-scale displacement events during the simultaneous flow of a low-molecular-weight polymer solution and heavy oil through porous media. Rheological measurements were taken to examine the viscosifying ability of the utilized polymer. The efficiency of the employed solutions in enhancing heavy oil recovery was also investigated using a pore network micromodel. Both macroscopic and microscopic sweep efficiencies were evaluated by analyzing high-resolution pictures continuously captured during the multiphase flow experiments. The rheological measurements revealed that viscosity of the polymer solution is more sensitive to increasing polymer concentration than salinity. Oil recovery experiments disclosed that polymer flooding could yield a recovery factor of about 58% of original oil in-place (OOIP), while the ultimate recovery factor for water flooding is only 35% of OOIP. The macroscopic observations proved that dwindling the formation of viscous fingers during polymer flooding is one of the main responsible factors for the significant improvement of heavy oil recovery. Moreover, the microscopic observations unveiled the noticeable effect of the polymer solution on the enhancement of microscopic sweep efficiency and showed that pulling effects and stripping mechanisms are effective in reducing the saturation of heavy oil at dead ends and pore walls.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Twisted tape inserts were used as swirl generators in the flow through a tube for enhancing heat transfer. Twisted tapes have commonly been applied in many thermal applications used in industry. Several modified twisted tapes have been investigated for improving the thermal performance of heat exchangers. The effects in tubes with modified rectangular-cut twisted tape (RC-TT) inserts with various free-spacing ratios (〈em〉s/w〈/em〉 = 2.0, 2.5, 3.0, 3.5 and 4.0) and edge–width ratios (〈em〉t/W〈/em〉 = 0.1, 0.15, 0.2 and 0.25) on heat transfer and pressure losses are reported. The RC-TT used in this work had a fixed thickness of 1.2 mm, width of 60 mm, length of 2000 mm and twist ratio (〈em〉y/W〈/em〉) of 3.0. Experiments were performed over a range of Reynolds numbers, 10,000 ≤ 〈em〉Re〈/em〉 ≤ 20,000, using air as a test fluid. A tube with a classical/typical twisted tape was also tested for comparison. In all cases, the Nusselt number tended to increase with the Reynolds number, while the friction factor and thermal performance showed the opposite trend. For the rectangular-cut twisted tape inserts, the friction factor and Nusselt number decreased, while thermal performance increased with increasing free-spacing ratios (〈em〉s/w〈/em〉) and edge–width ratios (〈em〉t/W〈/em〉). Furthermore, the maximum thermal performance was achieved at the lowest free-spacing ratio (〈em〉s/w〈/em〉), edge–width ratio (〈em〉t/W〈/em〉) and Reynolds number (〈em〉Re〈/em〉).〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Diversity patterns of tropical alpine vegetation is poorly studied. We estimated vascular plant floristic richness for two typical afro-alpine communities in Mount Kenya using a series of nested plots sized from 25 to 100 m〈sup〉2〈/sup〉. The 〈em〉α〈/em〉-diversity was low for all plot sizes (4.8–7.8 and 12.8 species per one and 100 m〈sup〉2〈/sup〉, respectively). Comparative analysis of 〈em〉α〈/em〉-, 〈em〉β〈/em〉- and 〈em〉γ〈/em〉-diversity across 22 plant communities from five Mountain regions (Mount Kenya, European Alps, Caucasus, Tibet, New Zealand Alps) revealed that area of mountain system was the only significant variable shaping the local richness; this effect became stronger with increasing spatial scale. Beta-diversity, by contrast, showed neither latitudinal trends nor significant correlation with other geographical or climatic variables. We conclude that the total area of mountain system is one of the main factors determining the regional species pool and, ultimately, the local diversity of alpine plant communities (the “echo-effect”). Small area and isolation of Mt. Kenya are considered as the main reasons for low local richness of its afro-alpine vegetation.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this paper, we reject commonly accepted views on fundamentality in science, either based on bottom-up construction or top-down reduction to isolate the alleged 〈em〉fundamental entities〈/em〉. We do not introduce any new scientific methodology, but rather describe the current scientific methodology and show how it entails an inherent search for foundations of science. This is achieved by phrasing (minimal sets of) metaphysical assumptions into falsifiable statements and define as fundamental those that survive empirical tests. The ones that are falsified are rejected, and the corresponding philosophical concept is demolished as a prejudice. Furthermore, we show the application of this criterion in concrete examples of the search for fundamentality in quantum physics and biophysics.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The philosophical problem of 〈em〉personal identity〈/em〉 has been widely discussed in contemporary analytic philosophy. The disputes over identity throughout time abound in references to thought experiments, excluding any connection to practical problems or to scientific knowledge and biotechnological practices. Nevertheless, some real cases challenge the pure metaphysical formulation of the problem and also show how science has an indubitable impact on the issue of identity. I will discuss the case of approximately 500 children who were 〈em〉appropriated〈/em〉 during the most recent Argentinian dictatorship (1976–1983), as well as their 〈em〉restitution〈/em〉 thanks to 〈em〉Abuelas de Plaza de Mayo〈/em〉’s fight and certain genetics outcomes. I will examine an alleged notion of 〈em〉genetic identity〈/em〉 thought to have stemmed from the restitution phenomenon; and I will argue against some criticisms to that notion departing from contemporary philosophy of biology and philosophy of science. Particularly, I will discuss if a genetic stance of personal individual identity can be considered as supported by contemporary biological knowledge; and if a pluralistic perspective on scientific practice that appraises the role of values allows us to maintain the reference to DNA regarding identity but overcoming aforementioned criticisms.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉We use a lubrication-type approach to investigate the dynamics of moving contact lines observed during droplet evaporation in the constrained vapor bubble experimental set-up. The effects of capillarity, viscous flow, and disjoining pressure are considered, while gravity is neglected. The disjoining pressure is described by a two-component model. Direct comparisons to the experimental recordings of receding contact line dynamics for n-butanol in a quartz cuvette are made.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉An independently developed discrete element code, MatDEM, was used to simulate buried hill-controlled earth fissures. An initial cubic discrete element method (DEM) model was obtained by considering the gravity accumulation of particles. A 2D stratigraphic model can be constructed by importing an elevation table of different strata into a cubic model. A simplified fluid-structure interaction method was then introduced to this. The model was simulated by gradually lowering the water level and then calculating the compression deformation of strata. By comparing the calculated settlement to the monitoring data, the validity and accuracy of the MatDEM model were verified. The area prone to earth fissures was predicted based on the analysis of the particle connections and horizontal displacement. The formation mechanism of the buried hill-controlled earth fissures was also explained. Thus, MatDEM is a good numerical simulation method for studying discontinuous problems, such as rock and soil cracking, and can be a new tool with which to study earth fissures.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Plants growing along steep elevational gradients experience variations in abiotic conditions. The elevational gradient also affects the diversity and abundance of pollinators associated with these plants. As a result, plants may have locally adapted floral traits. However, detailed assessments of multiple floral traits along elevational gradients are often neglected despite the traits being important for plant sexual reproduction. We tested the association of floral traits with pollinators in response to elevation by identifying pollinators and measuring morphological and biochemical floral traits as well as studying the breeding systems of ten aggregated 〈em〉Rhododendron〈/em〉 species in the Sikkim Himalaya. Corolla length, nectar volume and distance between stamen and stigma significantly decreased with elevation. In contrast, nectar concentrations were positively associated with elevation. Birds, bumblebees and flies were the three dominant pollinator groups. Bird visits showed a strong negative association with elevation while visits by bumblebees and flies increased with elevation. Species with longer corollas and higher nectar volumes showed higher rates of bird visits, while bumblebees were associated with species that had higher nectar concentrations. Fruit set following cross-pollination was high compared to self-pollination, and higher pollen limitation and auto-fertility were observed among species in higher elevations. These observed patterns in the association between floral traits and pollinator groups in response to elevation may help generate testable hypotheses on alpine plant–pollinator responses to climate warming.〈/p〉

Beschreibung: 〈h3〉摘要〈/h3〉 〈span〉 〈h3〉目 的〈/h3〉 〈p〉污染物质的存在会引起海底环境中的许多经济和 生态问题. 本文以遥控无人潜水器 (ROV) 为基 础承载平台, 实现基于空化喷射清洗技术的水下 结构表面附着物清洗.〈/p〉 〈/span〉 〈span〉 〈h3〉创新点〈/h3〉 〈p〉将空化射流清洗技术与 ROV 结合, 并利用空化 泡在清洗表面区域溃灭产生的微射流冲击, 以达 到清理水下表面附着物和污垢层的目的.〈/p〉 〈/span〉 〈span〉 〈h3〉方 法〈/h3〉 〈p〉1. 通过计算流体动力学 (CFD) 仿真与实验, 针 对 ROV 水下喷射模型, 在不同状态和不同参数 下对水下射流的规律进行测试与比较. 2. 实验对 比验证在不同喷射距离下所设计的空化射流清〈/p〉 〈/span〉 〈span〉 〈h3〉结 论〈/h3〉 〈p〉1. 当入口压力 〈em〉P〈/em〉=30 MPa, 孔径 〈em〉d〈/em〉=2 mm, 出口长 度 〈em〉L〈/em〉=16 mm 和出口直径 〈em〉D〈/em〉=16 mm 时, 水下喷嘴 具有更高的清洁度和清洁效率, 可以满足清洁要 求. 2. ROV 喷嘴离水下泥浆越远, 冲刷深度越浅. 3. 所设计的 ROV 空化喷射清洁装置与目标的距 离越近, 清洗强度越高; 然而, 当压力恒定且距 离太近时, 过度阻力会削弱冲洗强度. 洗装置清理海底生物的能力.〈/p〉 〈/span〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Mosses are a dominant ground cover in a wide array of ecosystems, especially in those developing under cold-stressed environments such as arctic and alpine ice-melting glacial forelands. Consequently, mosses may influence the performance and distribution of other plants. Here, we assessed the nature of interactions between vascular plants and cushion-forming mosses in three alpine communities in the northern Patagonian Andes. We recorded species richness, plant abundance and cover of vascular plants within and outside moss cushions, measuring also patch area and moss layer depth. To determine the effect of mosses on vascular plant assemblages, we calculated the relative interaction index (RII) in terms of richness, abundance and cover of all vascular plants, and of individual species. Moss-cushion patches showed higher species richness, plant abundance and cover in comparison with bare ground areas. Overall, the diversity of vascular plants increased with both moss-cushion area and layer depth. Species-specific RII values revealed that the effects of moss cushions on neighboring vascular plants were predominantly positive for all three plant communities surveyed. These results highlight the role of mosses as nurse plants in alpine ice-melting glacial forelands and, thus, as ecosystem engineers that can be key in maintaining vascular plant diversity.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Wings with large aspect ratio have large bending moment and torque, so the poor flexural and torsional stiffness are noteworthy. The application of composite materials in wing structure can improve the performance of wing. In the design process of the wing with high aspect ratio, the design parameters of the wing are preliminarily set. Then, the wing configuration is determined according to the force characteristics referring to the indexes of the Predator unmanned aerial vehicle (UAV), and on the basis of the composite material mechanics and finite element theory, the finite element model of the wing is designed as well. Next, we carry out the aerodynamic analysis in FLUENT. At last, we use ANSYS Composite Pre/Post (ACP) module to establish the static analysis of the wing, and two improvement schemes are proposed to deal with the problem that the wing with high aspect ratio would encounter.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Continuity as appears to us immediately by intuition (in the flow of time and in motion) differs from its current formalization, the 〈em〉arithmetical continuum〈/em〉 or equivalently the set of real numbers used in modern mathematical analysis. Motivated by the known mathematical and physical problems arising from this formalization of the continuum, our aim in this paper is twofold. Firstly, by interpreting Chaitin’s variant of Gödel’s first incompleteness theorem as an inherent uncertainty or fuzziness of the arithmetical continuum, a formal set-theoretic entropy is assigned to the arithmetical continuum. Secondly, by analyzing Noether’s theorem on symmetries and conserved quantities, we argue that whenever the four dimensional space-time continuum containing a single, stationary, asymptotically flat black hole is modeled by the arithmetical continuum in the mathematical formulation of general relativity, the hidden set-theoretic entropy of this latter structure reveals itself as the entropy of the black hole (proportional to the area of its “instantaneous” event horizon), indicating that this apparently physical quantity might have a pure set-theoretic origin, too.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Concentration-induced convection of a binary metal melt in a rectangular crucible has been studied numerically in the case of a mixture with a eutectic phase diagram. The calculations are performed for realistic parameters which correspond to the pair of metals Sn-Pb. A solid rod with non-wettable boundaries and a non-uniform longitudinal temperature distribution on the surface is immersed into the melt vertically at the center of the crucible. The condition of complete non-wetting allows us to consider the interface between the melt and the rod to be free. The temperature non-uniformity leads to inhomogeneity of the surface tension. As a result, the thermocapillary force generates a steady convective flow first on the surface of the rod and then in the volume. Due to this motion, the heavy component of the alloy is transferred along the rod’s surface to the butt-end. At the boundary patches with the excess of concentration it has been extracted into the volume by means of the desorption mechanism. In the presence of weak convection in the volume, this component is partially accumulated near the bottom of the crucible under the butt-end. Thus, there takes place a process of separation of heavy admixture for the two-component metal melts.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This paper refers to a subjective approach to Ecosystems, referred to as Impure Systems to capture a set of fundamental properties. There are four main phenomenological components: directionality, intensity, connection energy and volume. A fundamental question in this approach to Impure Systems is the intensity or forces of a relation. Concepts as the system volume, and propose a system thermodynamic theory based in the Law of Zipf and the temperature of information are introduced. It hints at the possibility of adapting the fractal theory by introducing the fractal dimension of the system.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Early 20th century philosopher Henri Bergson posited an initial push that propelled the diversity of life forward into a varied, novel future: The 〈em〉élan vital〈/em〉, a necessary force or impulse that animated life’s progress and development. His idea had largely been abandoned by mid-century. Even so, much of the conceptual and explanatory work this impulse targeted is yet in want of an explanation. In particular, Bergson’s derelict ideas on evolution addressed three areas that have once again become relevant in the effort to unite evolutionary genetics, biological development, and ecological context (often shortened to evo/devo/eco): (1) the purposeful nature of individual organisms and their parts; (2) the integrative, holistic, non-linear emergent dynamics seen in evolutionary processes; and (3) how genuine novelty emerges into the universe (Ellegren and Galtier in Nat Rev Genet 17(7):422, 〈span〉2016〈/span〉; Simondon et al. in On the mode of existence of technical objects. Univocal series, Univocal Publishing LLC, Minneapolis, 〈span〉2017〈/span〉; Bang, in: Winther-Lindqvist, Bang, Valsiner (eds) Nothingness: philosophical insights into psychology, Transaction Publishers, Somerset, 〈span〉2016〈/span〉; Moreno and Mossio in Biological autonomy: a philosophical and theoretical enquiry. History, philosophy and theory of the life sciences, Springer, Dordrecht, 〈span〉2015〈/span〉). In this paper I argue that Bergson’s ideas may yet be relevant to these questions, and his work warrants a reexamination in light of current problems in evolutionary biology. This is not a call to ‘return’ to Bergson, nevertheless his notions about complexity suggest ways of looking at current biological problems in ways that offer a heuristic insight worth entertaining. Bergson’s Nobel Prize-winning book, 〈em〉Creative Evolution〈/em〉, provided a strikingly prescient early 20th century framework for understanding how Darwinian evolution acts as an engine for generating new forms (Bergson in Creative evolution (M. Vaughan, trans., vol. 231), University Press of America, Lanham, Bergson 〈span〉1911〈/span〉).〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉When two bodies collide with each other, they change their motion. Many physics textbooks explain that the change in motion is 〈em〉caused〈/em〉 by the force or impulse exerted on the body during the collision. This is not the whole story, I argue, in case the bodies are 〈em〉rigid〈/em〉. In this case, the change in motion cannot be causally explained solely by how the bodies are configured before and during the collision but instead should be explained partly by what happens after the collision. That is, the collision between rigid bodies should better be interpreted as a case of 〈em〉retrocausation〈/em〉 where the future causally affects the past or present. This retrocausal interpretation of the collision does not suffer a general problem raised against retrocausation, known as the 〈em〉bilking〈/em〉 argument. And how the influence of the cause propagates backward in time to the effect in the collision is no more mysterious than how a body moves continuously in classical mechanics or how the future affects the past in proposed retrocausal models for the EPR thought experiment in quantum mechanics.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The aim of the paper is to argue for the cognitive unity of the mathematical results ascribed by ancient authors to Thales. These results are late ascriptions and so it is difficult to say anything certain about them on 〈em〉philological grounds〈/em〉. I will seek characteristic features of the cognitive unity of the mathematical results ascribed to Thales by comparing them with Galilean physics. This might seem at a first sight a rather unusual move. Nevertheless, I suggest viewing the process of turning geometry into an axiomatic-deductive science as a 〈em〉process of idealization in mathematics〈/em〉 that is parallel to the process of idealization in physics. In Kvasz (Acta Phys Slovaca 62:519–614, 2012) I offered an epistemological reconstruction of the process of idealization in physics during the scientific revolution of the seventeenth century. In the present paper I try to employ these epistemological insights in the 〈em〉process of idealization in physics〈/em〉 and propose a reconstruction of the cognitive unity of the mathematical results ascribed to Thales, who can, on the basis of these ascriptions, be seen as one of the initiators of idealization in mathematics.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Liquid degassing takes place in several space processes (cooling and lubrication of hardware, combustion of liquid propellants etc.) during launching and re-orbiting of rockets and workstations. The present work studies the effect of hypergravity acceleration on the two phase flow that is developed during the degassing of a liquid jet. Liquid is initially saturated with dissolved gas at 200 kPa and 400 kPa and is then injected at the bottom of a liquid column having its top open to atmospheric pressure. Due to the sudden decompression inside the column, the liquid jet becomes supersaturated with dissolved gas, thus triggering the formation of degassing bubbles within its volume. The local liquid flow pattern inside the column is tracked by recording the motion of bubbles. Experiments are conducted at 1 g, 2 g and 8 g accelerations, using the Large Diameter Centrifuge (LDC) facility of the Technology Center (ESTEC) of the European Space Agency (ESA). The liquid flow behavior registered at varying hypergavity conditions is quite interesting. For an injection pressure of 200 kPa the liquid velocity magnitude increases with acceleration level possibly because of the inertial shear force. Increasing the injection pressure to 400 kPa, not only the magnitude, but also the direction of liquid velocity varies possibly due to the larger effect of Coriolis force induced by the increased liquid velocities.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Discrete element simulation on ballasted beds is an important method to study the service characteristics of ballasted tracks; an effective simulation should be based on proper ballast parameters. Ballast contact parameter, which exhibits a high discreteness affected by factors such as material, shape, and gradation, can effectively be calibrated by an angle of repose test. Based on the testing principles of a multi-parameter response surface method, the Box-Behnken method is adopted to design the angle of repose test under the influence of restitution, static friction, and rolling friction coefficients; laboratory-measured results are combined with the simulation; regression analyzed angle of repose is considered as the goal; parameters optimization and ballasted bed resistance simulations are verified for multiple parameters. The results demonstrate that Chinese special-grade ballasts exhibit an average laboratory-measured angle of repose of (39.78±1.27)°, and the optimal combination of parameters in this discrete element simulation based on the response surface method are as follows: the restitution coefficient is 0.72, the static friction coefficient is 0.56, and the rolling friction coefficient is 0.27. The results of the lateral resistance simulation are in accordance with the laboratory test, indicating that the optimal parameters are usable. The multi-parameter response surface method effectively helps calibrate the parameters of the discrete element simulation on ballasted beds.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Water channeling of fractured carbonate rocks seriously restricts oil well production and is particularly prominent in the Troyes oilfield, located in the north of Kazakhstan. A nanometer particulate matter (PM) solution was used to evaluate the plugging ability of matrix and fractured core in a fractured carbonate model. Results showed that PM had good dispersion and swelling ability in simulated formation water. The swelling rate reached more than 300% in 3 d. PM had a perfect deep plugging effect in both matrix core and fractured core. The residual resistance coefficient of matrix and fractured core after plugging reached between 3.29 and 5.88, and the plugging rate was between 69.58% and 83.01%. The higher the residual resistance coefficient, the higher the plugging rate. PM has a good selective plugging effect on oil/water. The oil/water selection coefficient 〈em〉R〈/em〉〈sup〉w/o〈/sup〉 was less than 1.0 and close to 0, mainly because of the different mechanisms of oil/water and PM. Scanning electron microscope (SEM) imaging results showed that the plugging mechanism of PM in the throat and fractures was manifested mainly in three aspects: adsorptive retention, mechanical trapping, and agglomeration plugging. The mechanism was further verified by energy disperse spectroscopy (EDS) elemental analysis technology.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉I investigate the construction of the mathematical concept of quaternion from a methodological and heuristic viewpoint to examine what we can learn from it for the study of the advancement of mathematical knowledge. I will look, in particular, at the 〈em〉inferential microstructures〈/em〉 that shape this construction, that is, the study of both the very first, 〈em〉ampliative〈/em〉 inferential steps, and their tentative outcomes—i.e. small ‘structures’ such as provisional entities and relations. I discuss how this paradigmatic case study supports the recent approaches to problem-solving and philosophy of mathematics, and how it suggests refinements of them. In more detail, I argue that the inferential micro-structures enable us to shed more light on the informal, heuristic side of mathematical practice, and its inferential and rational procedures. I show how they enable the generation of a problem, the construction of its conditions of solvability, the search for a hypothesis to solve it, and how these processes are representation-sensitive. On this base, I argue that: 〈/p〉 〈ol〉 〈li〉 〈p〉the recent development of the philosophy of mathematics was right in moving 〈em〉from〈/em〉 Lakatos’ initial investigation of the formal side of a mathematical proof 〈em〉to〈/em〉 the investigation of the semi-formal (or informal), heuristic side of the mathematical practice as a way of understanding mathematical knowledge and its advancement.〈/p〉 〈/li〉 〈li〉 〈p〉The investigation of mathematical practice and discovery can be improved by a finer-grained study of the inferential micro-structures that are built during mathematical problem-solving.〈/p〉 〈/li〉 〈/ol〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The capillary driven seepage in porous media under microgravity conditions is investigated. Experiments on the flow of a liquid in an inhomogeneous artificial porous medium are presented. A non-stationary mathematical model of the flow of a multiphase fluid in a sample of a porous medium is described. The experimental data are compared with the results of a three-dimensional numerical simulation of the multiphase seepage process. The behavior of the imbibition front when passing through a boundary of medias with different permeability is investigated.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The nervous system is made of a large number of neurons. Time-varying balance between excitatory and inhibitory neurons is important to activate appropriate modes of electrical activity. A realistic biological neuron is complex, often presenting various electrophysiological activities and diffusive propagation of ions in the cell. Therefore, the physical effects of electromagnetic induction become very important and should be considered when estimating signal encoding and mode selection. Synaptic plasticity and anatomical structure have been developed to enhance the self-adaption of neurons. Thus, the electrical mode with the most effective links and weights can be selected to benefit information encoding and signal propagation between neurons in the network. As a result, the demand for metabolic energy can be greatly reduced. In this review, neuron model setting with biophysical effects, modulation of astrocytes, autapse formation and biological function, synaptic plasticity, memristive synapses, and field coupling between neurons and networks are reviewed briefly to provide guidance in the field of neurodynamics.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉One cause of thrombocytopenia in astronauts after spaceflight is decreased platelet production. To increase our understanding of thrombopoiesis in humans while in space, we investigated the effects of simulated microgravity, achieved using a random positioning machine (RPM), on megakaryoblastic cells (MEG-01 cell line). Exposure of MEG-01 cells to simulated microgravity for up to one week significantly increased cellular apoptosis compared to the static group (1 g-control). Flow cytometry analysis of the cell cycle revealed a significant increase in the percentage of cells in the G0/G1 phase after one week of RPM-exposure compared to the static group. Additionally, after one week, a difference in morphology was detected between the cells of the static group and the cells exposed to microgravity conditions. The expression of the CD33 surface marker was significantly decreased after a one week of microgravity exposure compared to the 1 g-control. We, therefore, concluded that in MEG-01 cells, simulated microgravity induces apoptosis, inhibits cell cycle progression of cells from G0/G1 into S phase, decreases cell proliferation, and decreases the expression of surface markers. We believe that, with insufficient physiological compensation, these changes under microgravity conditions may lead to disorders of megakaryocytes differentiation and/or decreased platelet production. It should also be noted that the human cell line MEG-01 could be a useful model for studying the effects of simulated microgravity on platelet production because of their ability to generate platelet-like particles.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The cavities of bamboos (Poaceae) are used by various animals. Most of the animals access these cavities either by existing cracks or by excavating bamboos with soft walls or small, thin-walled bamboos. Only a few animals excavate into the cavities of large and thick- and hard-walled internodes of mature bamboos. We studied two lizard beetle species (Coleoptera: Erotylidae: Languriinae), 〈em〉Doubledaya ruficollis〈/em〉 and 〈em〉Oxylanguria acutipennis〈/em〉, that excavate into large internode cavities of recently dead mature bamboos and have morphological modifications. We observed that females of 〈em〉D. ruficollis〈/em〉 used their mandibles to bore oviposition holes on 〈em〉Schizostachyum〈/em〉 sp. (mean wall thickness = 3.00 mm) and 〈em〉O. acutipennis〈/em〉 did so on 〈em〉Dendrocalamus〈/em〉 sp. (3.37 mm) bamboos. Previous studies suggested that the markedly asymmetrical mandibles and needle-like ovipositors of females in the genus 〈em〉Doubledaya〈/em〉 are adaptive traits for excavating hard-walled bamboos for oviposition. Therefore, we measured their mandibular lengths and ovipositor lengths. 〈em〉D. ruficollis〈/em〉 females had greater asymmetry in the mandibles and shorter and less-sclerotized ovipositors than females of congeners using small bamboos. In contrast, 〈em〉O. acutipennis〈/em〉 females had slightly asymmetrical mandibles and elongated, well-sclerotized ovipositors. Oviposition holes of 〈em〉D. ruficollis〈/em〉 were cone-shaped (evenly tapering), whereas those of 〈em〉O. acutipennis〈/em〉 were funnel-shaped (tube-like at the internal apex). This suggests that 〈em〉D. ruficollis〈/em〉 females excavate oviposition holes using the mandibles only, and 〈em〉O. acutipennis〈/em〉 females use both the mandibles and ovipositors. These differences suggest different oviposition-associated morphological specialization for using large bamboos: the extremely asymmetrical mandibles in 〈em〉D. ruficollis〈/em〉 and elongated, needle-like ovipositors in 〈em〉O. acutipennis〈/em〉.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉An influence of a spatial temperature modulation of the heat release/consumption at the interface on nonlinear convective flows in the 47v2 silicone oil - water system, has been investigated. Two types of boundary conditions on lateral walls: periodic boundary conditions corresponding to laterally infinite two-layer system and rigid heat-insulated lateral walls corresponding to the closed cavity, have been considered. It is shown that the spatial modulation can change the sequence of bifurcations and lead to the appearance of new oscillatory regimes. Specifically, pulsating traveling waves changing the direction of propagation, as well as regimes corresponding to period doubling, period-four and period-eight bifurcations, have been obtained.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The model of water vapor condensation on a composite V-shaped surface with multi wettability gradients was built and the condensation process with different gravity was studied by molecular dynamics to find out whether this model could control the condensation mode and accelerate the condensate drainage from the micro-perspective. With the absence of gravity, the simulation results indicated that the condensation mode could be controlled as a dropwise condensation. What’s more, the movement of condensate nano-droplet also could be controlled, which was helpful for increasing the efficiency of condensate drainage. The temperature of hot wall was largest while it was smallest for cold wall. The temperature of water was in the middle. The result was in accordance with the law of energy conservation. However, the condensation process was different with the effect of gravity. It can be concluded that the condensation process was much quicker with greater gravity, leading to the larger condensation rate. The temperature of cold wall and water were larger than that of hot wall, especially for greater gravity. It was because the part of energy generated by gravity transferred to the thermal energy of water and cold wall, and the other part transferred to the kinetic energy of water. The gravitational potential energy and kinetic energy increased with greater gravity, while the thermal energy increased first and then decreased, corresponding well with the final temperature of condensation process with different gravity. The results will provide a microcosmic mechanism for space experiment and guidance for space system drainage.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Owing to their excellent theoretical capacity, Li-Si alloys have been extensively investigated as potential Lithium-ion batteries. Knowledge of the mechanical, acoustical, and optical properties of Li-Si alloys is important in order to improve battery performance. In the present study, we calculated the mechanical, acoustical, and optical properties of several Li-Si alloys theoretically. Our investigation confirms the mechanical stability of these Li-Si alloys. With increasing lithium content, Li-Si alloys become increasingly vulnerable to shape deformation as the number of Si-Si bonds decreases. The analysis of elastic moduli shows that the bulk modulus increases with the increase of lithium contents. Li〈sub〉22〈/sub〉Si〈sub〉5〈/sub〉 has the strongest anisotropic Young’s modulus. The sequence of degree of anisotropic Young’s modulus is Li〈sub〉22〈/sub〉Si〈sub〉5〈/sub〉〉Li〈sub〉15〈/sub〉Si〈sub〉4〈/sub〉〉LiSi〉Li〈sub〉17〈/sub〉Si4〉Li〈sub〉12〈/sub〉Si〈sub〉7〈/sub〉〉Li〈sub〉13〈/sub〉Si〈sub〉4〈/sub〉. From an analysis of the anisotropy of acoustic velocity, the transverse velocities are shown to be less than the corresponding longitudinal acoustic velocities. The longitudinal wave of the cubic system is the fastest along the [111] direction, while it is the fastest along the [001] direction for the orthorhombic system and the [010] direction for the tetragonal system. In addition, all the studied Li-Si alloys have relatively low thermal conductivities and show a higher anisotropy when photon energies are lower than 20 eV. We conclude that the studied Li-Si alloys are promising dielectric materials.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Fluid-elastic instability of tube bundles is the main cause of vibration failure of heat exchangers. To establish more reasonable and reliable design guidelines for fluid-elastic instability of tube bundles subjected to two-phase cross flow, we investigated experimentally the effects of the flow conditions of the two-phase flow and the geometrical characteristics of the tube bundles on damping, vibration, and fluid-elastic instability. Moreover, we proposed recommended values of the instability constant based on the conductivity difference measurement (CDM) model and the classification of tube bundle arrangements. The reliability of these values was also verified. The results indicated that the damping ratio in the lift direction was smaller than that in the drag direction and fluid-elastic instability was more prone to occur. The order of stability of the four tube bundle arrangements from high to low was normal triangular, normal square, rotated square, and rotated triangular. Thus, to avoid fluid-elastic instability, the normal triangular tube bundle is recommended for large shell-and-tube heat exchangers subjected to two-phase cross flow. In addition, for normal square and normal triangular tube bundles, the recommended instability constant is 4.0. For rotated square and rotated triangular tube bundles, the recommended instability constant is 1.1 when the mass damping parameter is less than or equal to 0.54, otherwise the value is 1.5.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The influence of gravity (including 0 G, 0.16 G, 0.38 G, 1 G and 1.8 G) on the antisolvent crystallization of 〈em〉L〈/em〉-histidine was investigated in a self-designed micro-channel crystallizer on a zero-G flight, which was successfully launched on June 13th, 2018. The stable form of 〈em〉L〈/em〉-histidine was obtained under microgravity, while only the metastable form can be observed in the ground experiments with the same inlet conditions. The possible reason is the extremely ordered flow field of the system in microgravity environment. A large amount of small particles aggregated at 1.8 G due to the enhanced micromixing, which favors nucleation. Bigger particles crystalized at Moon gravity (0.16 G) without the excessive consumption of the supersaturation by explosive nucleation and with moderate convection of the system. It is concluded that both nucleation and crystal growth were influenced by the micromixing status in the system due to the altered gravity extent.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Birds which fly in coordinated cluster-flocks can benefit through the formation of group-level structures and patterns which can deter predators by visual confusion. Though unlike V-formation flight, cluster-flocking increases the energetic cost of flight, particularly in denser flocks. Cluster formations therefore provide a unique opportunity to investigate trade-offs between increased work rate (e.g. higher flap frequency) and other benefits of flocking. As part of a routine 9-km training flight release, a flock of six homing pigeons (〈em〉Columba livia〈/em〉) with 5 Hz GPS and 200 Hz accelerometer biologgers attached flew an alternative trajectory totalling 177 km and 256 min of flight. We provide the first evidence that during a long-duration flight, pigeons’ pairwise and group-level distances increased (i.e. group structure changed), while flap frequency decreased over time. This implies that as birds tire during long-duration flight, the ultimate functions of cluster-flocking—primarily anti-predator benefits—are overridden by the proximate costs of flying close to conspecifics.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Ecological light pollution alters an environment’s light cycle, potentially affecting photoperiod-controlled behavior. Anurans, for example, generally breed nocturnally, and the influence of light pollution on their natural history may therefore be especially strong. In this study, we tested this hypothesis by measuring male calling behavior of anuran communities in natural wetlands in southern Brazil exposed or not exposed to street lights. We recorded seasonal and diel calling activity and calling response to a light pulse. The peak calling season differed between continuously lit and unlit locations with most species in illuminated wetlands shortening their calling season and calling earlier in the year. In unlit breeding sites, 〈em〉Boana pulchella〈/em〉, 〈em〉Pseudis minuta〈/em〉, and 〈em〉Pseudopaludicola falcipes〈/em〉 confined their calling activity to well-defined hours of the night, but in continuously lit areas, these species called more continuously through the night. A 2-minute light pulse inhibited calling, but only in unlit wetlands. After a light pulse, frogs quickly resumed calling—suggesting acclimatization to brief artificial light exposure. Our field experiment presents a convincing example of ecological light pollution showing that artificial light alters the seasonal and diel calling time of some South American wetland anurans. It also documents their acclimatization to brief lighting when being continuously exposed to light.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The tension–tension fatigue performance of T700/MTM46 composite laminates after hygrothermal aging was investigated and compared with those of virgin T700/MTM46 laminates. The most significant failure mode of the moisture-saturated fatigue specimens is still severe delamination, and the stiffness degradation of moisture-saturated fatigue specimens can be divided into two distinct stages. However, the hygrothermal conditions will aggravate the stiffness degradation of the composite laminates during fatigue. Damage evolution was studied by the edge view of the specimens. The degree of damage of the saturated specimens is more serious than that of the virgin specimens at the same percentage of fatigue life during the fatigue process, especially in the initial stage. The distribution of fatigue life in each stress level was determined. The 〈em〉p〈/em〉-〈em〉γ〈/em〉-〈em〉S〈/em〉-〈em〉N〈/em〉 surfaces were established to predict a reliable fatigue life. The results show that the reliable fatigue life of the moisture-saturated specimens is much lower than that of the virgin specimens under the same conditions. Although the hygrothermal environment does not show a significant effect on the static tensile properties of the T700/MTM46 composite laminates, the fatigue performance is significantly degenerated.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉This paper aims to study the damage mechanisms and mechanical responses of a Type III composite vessel by considering the effect of autofrettage. Firstly, damage models using Hashin failure criteria and 3D strain-based damage evolution laws for composite layers are implemented by implicit finite element codes using ABAQUS-UMAT (user material subroutine module). Secondly, the appropriate autofrettage pressure is determined by finite element analysis (FEA), in which the fiber stress ratio and the generated residual stress in the aluminium liner are investigated according to the related regulations. Finally, the effects of the autofrettage process on the internal pressure-displacement curves and damage evolution behaviors for matrix and fiber are discussed. For a composite vessel after autofrettage, the stresses in the composite layers and aluminium liner are also explored. Results show that the progressive damage evolution behaviors of the composite vessel with autofrettage and without autofrettage are basically consistent except there is some difference during the unloading process and the repressurization process in respect of matrix damage.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉To provide a theoretical basis for the flow diversion control of a bifurcate tunnel, the flow separation characteristics and local loss model at the tunnel bifurcation were analyzed by combining numerical simulation and theoretical derivation. The results showed that the sudden change of boundaries interrupts uniform flow when air flows through a tunnel bifurcation, causing changes in flow velocity and direction. When the diversion ratio 〈em〉β〈/em〉 is small, the flow is separated on the downstream mainline tunnel sidewall close to the bifurcation point and the ramp sidewall away from bifurcation point; when 〈em〉β〈/em〉 is large, the flow is separated on the downstream mainline sidewall away from bifurcation point and the ramp sidewall close to bifurcation point. The local loss on flow division is caused mainly by velocity gradient changes and flow deflection and separation. When the air flux ratio 〈em〉q〈/em〉 of the downstream mainline tunnel to that of the ramp is equal to their cross-sectional area ratio 〈em〉ϕ〈/em〉, local loss coefficients are at their minimum; when 〈em〉q〈/em〉〉〈em〉ϕ〈/em〉, the loss coefficients decrease with the increase of 〈em〉β〈/em〉, but the loss coefficient for the ramp increases as the bifurcation angle rises. When 〈em〉q〈/em〉〈〈em〉ϕ〈/em〉, the loss coefficients increase with the increase of 〈em〉β〈/em〉, but the loss coefficient for the ramp declines as the bifurcation angle rises. Finally, a theoretical formula to predict the dividing flow local loss coefficient of a bifurcate tunnel is established based on the airflow deflection angle assumption. The proposed model has a higher precision in prediction than other formulas.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉In this study, Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉-water nanofluids flowing through a micro-scale T45-R type Tesla valve was investigated numerically. Both forward and reverse flows were investigated based on a verified numerical model. The effects of nanofluids flow rate, temperature, and nanoparticle volume fraction on fluid separation in the bifurcated section and the pressure drop characteristics were analyzed. It was found that most of the nanofluids flow into the straight channel of the bifurcated section when flowing forward, and into the arc channel when flowing reversely. The percentage of the main flow increases with flow rate, temperature, and nanoparticle volume fraction. Additionally, the jet flow from the arc channel leads to a larger pressure drop than forward flow. Finally, the diodicity was found most affected by flow rate, and a correlation used to predict the change in diodicity with the flow rate was proposed.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The hydraulic properties of soil (i.e. soil-water characteristic curve (SWCC) and coefficient of permeability) govern the moisture flow in it. Previous research has indicated that the hydraulic properties of soil are dependent on its pore-size distribution. An improved capillary model is now proposed to explain the concept of the pore-size distribution in soil and its relationship to SWCC. A new model, the “valve model”, is also proposed as the explanation for water flow in unsaturated soil. The pore-size distribution function is incorporated in the “valve model” and is used to calculate the relative coefficient of permeability for unsaturated soil. In this paper, the role of the pore-size distribution function in the estimation of SWCC and the permeability function are explained. Equations are proposed for estimating the pore-size distribution function from the experimental data of relative coefficient of permeability. The results from the proposed equations agree with the experimental data from laboratory measurement and published data.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉The highly invasive knotweeds (Reynoutria spp.) are still infrequent in mountain regions. Despite their current low abundance, they may represent a significant threat for high elevation ecosystems if their population dynamics remain as aggressive as in lowlands during their range expansion to higher elevation. The aim of this study is to assess the knotweed’s invasion potential in mountainous regions by studying patch dynamics along an elevational gradient (between 787 and 1666 m a.s.l.) and by reviewing existing literature on their presence and performance in mountains. The outlines of 48 knotweed patches located in the French Alps were measured in 2008 and in 2015 along with biotic, abiotic and management variables. Based on these variables, knotweed’s cover changes and patch density were predicted using mixed models. Results showed that elevation has no effect on knotweeds dynamics along the studied elevational gradient. It appeared that the local expansion of knotweed patches is essentially controlled by the patches’ initial size and the distance to roads and rivers, i.e. to obstacles and sources of disturbance. Shade and patches’ size also impact knotweed patch density, probably through an effect on the species’ clonal reproduction and foraging strategies. Interestingly, patches seemed insensitive to the gradient of mowing frequency sampled in this study (between zero and five times per year). All evidences indicate that the knotweed complex is able to colonize and thrive in mountains areas. However, due to the particularities of its spatial dynamics, adequate and timely actions could easily be undertaken to prevent further invasion and associated impacts and reduce management costs.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Dioecious plants often exhibit deviations from expected 1:1 sex ratios. Genus 〈em〉Salix〈/em〉 is a notable example of the female-biased sex ratio. Quite surprisingly, there are very few studies retesting observed bias patterns from the different parts of the species range. We have determined whether isolated subalpine populations of 〈em〉Salix lapponum〈/em〉 exhibit a biased secondary sex ratio, measured the size of the plants, and tested the spatial and ecological correlations of the bias at fine and broad scales. Males were generally taller than females, suggesting that a different allocation of resources may occur in both sexes. Despite this, we found consistent female bias with females on average twice as common as males in most populations studied. No correlations of sex ratio with elevation as a proxy of environmental harshness and proportion of non-flowering individuals were found. Additionally, no differences in spatial sex segregation and microhabitat preferences were found between males and females at a fine scale within the studied populations. Our results suggest that the biased sex ratio in 〈em〉S. lapponum〈/em〉 is not environment-dependent and probably originates during early stages of ontogenetic development (seeds).〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Exceptional natural phenomena, such as those that occur during a total solar eclipse, provide unique opportunities to study animal behavior outside the naturally evolved context, which can be informative in more general terms. Circumstantial descriptions of abnormal animal behavior during solar eclipses abound, although scientific studies conducted during an eclipse are relatively rare due to inherent logistical difficulties. Here, honey bee foraging and homing behavior were studied during the total solar eclipse of August 21, 2017. In the first experiment, we studied foraging behavior of honey bees during the progression of the solar eclipse and found that the foraging activity drastically decreased but did not completely cease during the totality of the eclipse, in contrast to previous reports of complete cessation. The data indicate that the level of ambient light can largely overrule the internal circadian rhythm of foraging honey bees. Furthermore, colonies with a higher need for foraging decreased their foraging activity less than satiated colonies, consistent with the hypothesis that individual foraging decisions may be influenced by colony state, which affects cost-benefit analyses. In a second experiment, the temporal dynamics of homing of released workers and drones was compared in periods before, during, and after the solar eclipse. During the totality of the eclipse, very few bees arrived back at their hive, while homing before the total eclipse was accelerated, particularly in drones. The results suggest that, while the homing abilities of honey bees are not compromised until the sun is completely eclipsed, they may still interpret the diminishing light as an indicator of deteriorating flight conditions. Our unique study provides some insight into the control of honey bee foraging behavior when external cues and internal circadian rhythms are at odds, lent support to the notion that food deprivation can lead to riskier foraging, and indicated that homing in honey bees is possible even with very small amounts of sunlight.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉Aggressive behaviour plays a fundamental role in the distribution of limiting resources. Thereby, it is expected to have consequences for fitness. Here, we explored the relationship between aggression and fitness in a long-term database collected in a wild population of the collared flycatcher (〈em〉Ficedula albicollis〈/em〉). We quantified the aggression of males during nest-site defence by conducting simulated territorial intrusions in the courtship period. We estimated the fitness of males based on their pairing success, breeding output and survival to next year. Earlier arriving and older males had a higher probability to establish pair-bond, and males that started to breed earlier fledged more young. Aggression did not predict pairing and breeding performances. However, the probability of a male to return in the next year was significantly related to aggression in an age-dependent manner. Among subadult males, more aggressive individuals had higher chances to return, while among adult males, less aggressive ones did so. This finding is in harmony with our general observation that subadult collared flycatcher males behave more aggressively than adult males when confronted with a conspecific intruder. Subadult males may be socially inexperienced, so they should be more aggressive to be successful. In contrast, if adult males suffer from higher physiological costs, a lower level of aggression may be more advantageous for them. Our study shows that aggressive behaviour can be a fitness-related trait, and to understand its role in determining fitness, age should be taken into account.〈/p〉

Beschreibung: 〈h3〉Abstract〈/h3〉 〈p〉While conservation management has made tremendous strides to date, deciding where, when and how to invest limited monitoring budgets is a central concern for impactful decision-making. New analytical tools, such as environmental DNA (eDNA), are now facilitating broader biodiversity monitoring at unprecedented scales, in part, due to time, and presumably cost, of methodological efficiency. Genetic approaches vary from conventional PCR (cPCR; species presence), to metabarcoding (community structure), and qPCR (relative DNA abundance, detection sensitivity). Knowing when to employ these techniques over traditional protocols could enable practitioners to make more informed choices concerning data collection. Using 12 species-specific primers designed for cPCR, eDNA analysis of the Yangtze finless porpoise (YFP; 〈em〉Neophocaena asiaeorientalis asiaeorientalis〈/em〉), a critically endangered aquatic mammal within the Yangtze River, we validated and optimized these primers for use in qPCR. We tested repeatability and sensitivity to detect YFP eDNA and subsequently compared the cost of traditional (visual and capture) sampling to eDNA tools. Our results suggest cPCR as the least expensive sampling option but the lack of PCR sensitivity suggests it may not be the most robust method for this taxon, predominately useful as a supplementary tool or with large expected populations. Alternatively, qPCR remained less expensive than traditional surveys, representing a highly repeatable and sensitive method for this behaviorally elusive species. Cost comparisons of surveying practices have scarcely been discussed; however, given budgetary constraints particularly for developing countries with limited local oversight but high endemism, we encourage managers to carefully consider the trade-offs among accuracy, cost, coverage, and speed for biodiversity monitoring.〈/p〉