Moose Research Articles

Influence of biotic and economic-anthropogenic factors on the attendance of artificial salt licks and the sex-age structure of the flock of the European moose, Alces alces (Linnaeus, 1758), in the conditions of the North-West of Russia

The relationship between the attendance of artificial salt licks by European moose, Alces alces (Linnaeus, 1758), and biotic and economic-anthropogenic factors in the territory of the Leningrad Province was assessed. Data on the attendance of 19 mineral feeding sites obtained from automatic photo-video recorders (camera traps) were used in the analysis. Among the biotic factors that have a significant impact on attendance, the remoteness of the salt lick from the perennial water pool and the category of biotope according to the ground cover were revealed. Among the economic and anthropogenic factors – the remoteness of the salt lick from settlements with a population of more than 500 people. Similarly, the relationship between the sex-age structure of the registered moose flock with factors from the same categories was assessed. In addition, the effect of the recorded numbers of different sex-age groups on each other was assessed. A significant dependence of the registration of adult males on the area of wetlands and linear objects (power lines and gas pipelines) located within the boundaries of 1500 ha around the salt lick, as well as on remoteness from settlements, has been established. A significant dependence of the registration of yearling males on the area of wetlands around the salt lick and the number of registered adult males was established. A significant dependence of the number of registered adult females on the remoteness of the salt licks from a perennial water pool was noted. At the same time, the effect of any of the habitat groups on the recorded number of females has not been confirmed. Estimated population growth in sample areas depends on the sex ratio of registered individuals. The influence of limiting factors (predation, feed availability, hunting press) acting on moose populations in sample areas according to the methods used has not been revealed.

Influence of Al11Ce3 Size and Distribution on the Electrochemical Properties of Sonoprocessed Al-10 wt.% Ce Alloy

Solidification of Al–Ce alloys under ultrasonic vibrations (Sonoprocessing) has a significant effect on the refining of Al11Ce3 intermetallic, which plays a key role in controlling the properties of this group of high-performance characteristics. In the current research, a group of as-received Al-10 wt% Ce alloys that were sonoprocessed under different temperatures was characterized. The influence of Al11Ce3 intermetallic size and distribution on the electrochemical properties of these alloys was investigated. Polarization tests in 3.5% NaCl solution were carried out and the recorded Tafel and impedance curves were studied. The corrosion test results were related to the microstructure characteristics as affected by sonoprocessing. Investigation of the as-received samples showed that ultrasonic vibrations broke the long lath-shaped particles of Al11Ce3 and obviously decreased their size and increased their surface area fraction. Sonoprocessing at the optimum temperature, 655 °C, reduced the Al11Ce3 particles size by 90% and enhanced their distribution in the matrix. This in its turn resulted in significant effects on their electrochemical behavior. Polarization tests showed that the corrosion rate of the un-sonoprocessed specimen decreased from ~ 0.00068 to 0.00006 mm/year after processing at the optimum condition (655 °C), and the polarization resistance increased from ~ 71 to 343 kΩ. By increasing the temperature of ultrasonic treatment beyond 655 °C, and the corresponding coarsening of the intermetallic particles, the corrosion rate slowly increased again, and concurrently, the polarization resistance decreased. The size and distribution of the intermetallic particles also influenced the formation of the corrosion pits, where the optimum sample showed shallow pits compared to those observed in the unprocessed specimen. This emphasizes the role of sonoprocessing in controlling the microstructure features and hence the electrochemical properties of Al-10 wt% Ce alloys.

End of the road: Short-term responses of a large mammal community to forest road decommissioning

Anthropogenic disturbances are increasing worldwide, causing wildlife habitat loss, alteration, and fragmentation. In Canada, the decommissioning of linear anthropogenic structures is identified as a promising tool to restore the habitat of threatened populations of boreal caribou (Rangifer tarandus caribou) by reducing food availability for alternate prey and decreasing encounter probabilities with predators. In this study, we monitored the use of 40 km of decommissioned forest roads by caribou, gray wolves (Canis lupus), black bears (Ursus americanus), and moose (Alces americanus) 1–3 years after reclamation, using 232 motion-activated camera traps. We compared four additive treatments (meaning that each successive treatment included the treatment prior): closing the road to human access, decompacting its soil, planting black spruce (Picea mariana) trees, and adding enriched soil. We assessed the influence of treatments, use by other large mammals, and characteristics of the surrounding environment on road use by the four species. Caribou used the planted treatment (which also included closing and decompacting) more than the closed-only (reference) treatment, but treatments did not influence the use of decommissioned roads by bears and moose. We could not assess the use of treated roads by wolves because of low sample size. Road use by caribou declined with local moose density, but increased with local bear density. Caribou were observed more frequently on roads surrounded by regenerating and mature coniferous stands; caribou also preferentially used roads surrounded by wetlands. Our results suggest that the treatment combining road closure, soil decompaction, and tree planting could be beneficial to caribou, highlighting the relevance of including active restoration efforts in caribou conservation programs. We recommend that such a treatment be added to road decommissioning protocols for the conservation of caribou, alongside broad-scale habitat protection.

PARAFASCIOLOPSOSIS INFESTATION OF YOUNG MOOSE (<i>ALCES ALCES</i>) DEPENDING ON WEATHER CONDITIONS

Differentiated approach to the study of infestation with parafasciolopsosis of different age categories of the European moose has been used for the first time. The features of Parafasciolopsis fasciolaemorpha invasion in a group of young (1-year and 1.5-year-old) moose under conditions of alternating abnormally dry and rainy seasons in the east of the European part of Russia are shown. A significant increase in the prevalence of invasion (PI) of this helminth in the moose population (up to 76.5 %), and especially in young individuals (1-year-old up to 62.5 %, 1.5-year-old up to 100 %), was clearly manifested in 2009–2019. A high inverse correlation (r = –0.74, p ≤ 0.05) of the extensiveness of parafasciolopsous invasion in 1.5-year-old species on the humidity regime of summer seasons was revealed. The decrease in watering of the territory during dry seasons contributed to an increase in the density of the intermediate host ( Planorbarius corneus ) and the concentration of the invasive onset in large water bodies. A high correlation (r = 0.90, p ≤ 0.05) was established between the total PI of parafasciolopsis in the moose group and infection of 1-year-olds. Significant infestation of young individuals ( Alces alces ) can negatively affect the state of the entire moose population and lead to decrease in numbers.

Peptide Biomarkers Discovery for Seven Species of Deer Antler Using LC-MS/MS and Label-Free Approach.

Deer antler is a globally widely used precious natural medicine and the material of deer horn gelatin. However, identification of deer antler species based on traditional approaches are problematic because of their similarity in appearance and physical-chemical properties. In this study, we performed a comprehensive antler peptidome analysis using a label-free approach: nano LC-Orbitrap MS was applied to discover peptide biomarkers in deer adult beta-globin (HBBA), and HPLC-Triple Quadrupole MS was used to verify their specificity. Nineteen peptide biomarkers were found, on which foundation a strategy for antlers and a strategy for antler mixtures such as flakes or powder are provided to identify seven species of deer antler including Eurasian elk (Alces alces), reindeer (Rangifer tarandus), white-tailed deer (Odocoileus viginianus), white-lipped deer (Przewalskium albirostris), fallow deer (Dama dama), sika deer (Cervus nippon), and red deer (Cervus elaphus) simultaneously. It is worth noting that our search found that the HBBA gene of sika deer, red deer, and North American wapiti (Cervus canadensis) in China may have undergone severe genetic drifts.

Microstructure and thermomechanical properties of Al11Ce3

This study investigates the microstructure and thermomechanical properties of the intermetallic compound Al11Ce3, which strengthens Al–Ce based eutectic alloys. Arc-melted bulk Al11Ce3, consisting of coarse, elongated grains oriented along the solidifying direction with internal twins, is hard and brittle at ambient temperature, with a microhardness of 4.3 ± 0.3 GPa and indentation fracture toughness of 0.70 ± 0.09 MPa m1/2. The thermal expansion coefficient varies from 14 × 10−6/K (at 100 °C) to 32 × 10−6/K (at 600 °C). Al11Ce3 oxidation kinetics follow a parabolic law, with rates at/below 500 °C slow enough to enable long-term testing in air. Plastic creep deformation is extensive at 500 °C under uniaxial compressive loads; the strain rates follow a power-law with respect to stress with a stress exponent of 5.6, indicative of dislocation-controlled creep deformation, and with an activation energy of 276 ± 29 kJ/mol (measured between 450 and 600 °C). The creep resistance of Al11Ce3 at 500 °C is similar to that of L12-Al3Sc.

Effect of micro-alloyed Ce on the microstructure evolution and mechanical properties of rolled Mg–0.6Al–0.5Mn–0.2Ca alloy sheets

In this study, the effect of minor Ce addition (0, 0.1, and, 0.3 wt.%) on the microstructure evolution and mechanical properties of rolled Mg–0.6Al–0.5Mn–0.2Ca (AMX100) alloy sheets is systematically investigated under different annealing processes. With 0.1 wt.% Ce addition, partial Al8Mn5 phases turn into Al8Mn4Ce. With 0.3 wt.% Ce addition, the number of the Al8Mn4Ce further increases and the Al–Ce phases are observed. The single-stage annealed alloys exhibit similar uniform fine-grained structures (∼6 μm) regardless of the Ce content, while the grain sizes of the two-stage annealed alloys increase obviously (∼10.9–11.9 μm). Especially, the abnormal grain growth occurs in the two-stage annealed AMX100-0.3Ce alloy. After the aging treatment, the yield strength (YS) of the two-stage annealed alloys is increased by ∼25–45 MPa, which is greatly higher than that of the single-stage annealed alloys (∼1–8 MPa). Note that the two-stage annealed AMX100–0.1Ce alloy displays a significant age-hardening response with the ultimate tensile strength (UTS) of ∼272 MPa and the elongation to failure (EF) of ∼14%, which is attributed to the formation of Al and Ca enriched Guinier-Preston (G.P.) zones. This work sheds light on the design and fabrication of low-cost dilute magnesium alloys with admirable age-hardening ability.

Robust Algorithms for Drone-Assisted Monitoring of Big Animals in Harsh Conditions of Siberian Winter Forests: Recovery of European elk (Alces alces) in Salair Mountains.

Simple SummaryForest animals can be used as a sensitive indicator of the real state of biodiversity. The research objective was to study the potential of drone planes equipped with thermal infrared imaging cameras for large animal monitoring in the conditions of Siberian winter forests with snow background at temperatures of −5 °C to −30 °C. The surveyed territory included the Salair State Nature Reserve in the Kemerovo Region, Russia. Drone planes were effective in covering large areas, while thermal infrared cameras provided accurate information in the harsh winter conditions of Siberia. The research featured the population of the European elk (Alces alces), which is gradually deteriorating due to poaching and deforestation. The designed technical methods and analytic algorithms are cost-efficient and they can be applied for monitoring large areas of Siberian, Canadian and Alaskan winter forests.There are two main reasons for monitoring the population of forest animals. First, regular surveys reveal the real state of biodiversity. Second, they guarantee a prompt response to any negative environmental factor that affects the animal population and make it possible to eliminate the threat before any permanent damage is done. The research objective was to study the potential of drone planes equipped with thermal infrared imaging cameras for large animal monitoring in the conditions of Siberian winter forests with snow background at temperatures −5 °C to −30 °C. The surveyed territory included the Salair State Nature Reserve in the Kemerovo Region, Russia. Drone planes were effective in covering large areas, while thermal infrared cameras provided accurate statistics in the harsh winter conditions of Siberia. The research featured the population of the European elk (Alces alces), which is gradually deteriorating due to poaching and deforestation. The authors developed an effective methodology for processing the data obtained from drone-mounted thermal infrared cameras. The research provided reliable results concerning the changes in the elk population on the territory in question. The use of drone planes proved an effective means of ungulate animal surveying in snow-covered winter forests. The designed technical methods and analytic algorithms are cost-efficient and they can be applied for monitoring large areas of Siberian and Canadian winter forests.

Creep properties and microstructure evolution at 260–300 °C of AlSi10Mg manufactured via laser powder-bed fusion

The aging behavior and creep resistance of eutectic AlSi10Mg (Al–10Si-0.6Mg, wt.%) manufactured by laser powder bed fusion (L-PBF) are studied at 260 and 300 °C. The Si phase, which forms a fine interconnected network of 100–200 nm filaments in the as-printed alloy, coarsens into blocky, 2–3 μm particles after 1 month exposure at 260 and 300 °C, with hardness decreasing following a power-law with exponent n = 0.06–0.08. AlSi10Mg with ∼1 μm Si particles (achieved by aging at 300 °C for 96 h) exhibits creep resistance at 260 and 300 °C, for test durations of a few days, comparable to those of (i) cast alloys: hypereutectic Al–Si alloys with coarse Si particles and eutectic Al–Ce, Al–Ce–Ni with much finer, and more coarsening-resistant eutectics phases (e.g., Al11Ce3, Al3Ni); and (ii) L-PBF Al–Mg–Zr alloys. At 260 and 300 °C, our L-PBF AlSi10Mg shows a power-law creep behavior with high apparent stress exponents (na = 10–13, higher than n = 4.0 for Al–Mg) for strain rates between ∼10−8 and ∼10−4 s−1. Also, a high apparent creep activation energy Qa = 256 kJ/mol is measured between 200 and 320 °C at 45 MPa, compared to Q = 142 kJ/mol for Al. These high apparent stress exponent and activation energy are consistent with power-law dislocation creep with a threshold stress, originating from load-transfer from the creeping Al(Mg) matrix to non-creeping Si particles.

Orientation relationships and interface structure between Al11Ce3 and Al in Al–Ce eutectic

Al–Ce eutectic alloy has attracted much attention due to its excellent heat resistance and castability. A large number of interfaces are contained in the Al–Ce eutectic alloy. As an intermediary connecting the aluminum matrix and the Al11Ce3 reinforcement phase, the interfaces play an important role in enhancing the strength and toughness of the alloy. In this paper, eutectic Al–Ce alloy was prepared, the orientation relationship at the Al11Ce3/Al interface and the interface structure were investigated. Classification of orientation relationship was proposed, and three orientation relationships were observed: OR1, [010]Al11Ce3//[001]Al, (00 1¯)Al11Ce3//(010)Al, (100)Al11Ce3//(1¯ 00)Al; OR2, [5 2¯ 0]Al11Ce3//[1 2¯ 1]Al, (001)Al11Ce3//(111)Al; OR3, [1¯ 13]Al11Ce3//[011]Al, (110)Al11Ce3//(100)Al, of which OR3 is a new orientation relationship reported for the first time. First-principle calculations suggest that Al11Ce3 is combined with Al through a Ce-terminated surface of (001)Al11Ce3. The electronic structure indicates that the interface between Al and Al11Ce3 are chemical adsorptions, and the two-phase interface has strong interaction. The strong interface between the reinforcing phase and Al matrix can effectively enhance the load transfer, thereby improving the strength of the material.

Trophic niche partitioning between two prey and their incidental predators revealed various threats for an endangered species.

Documenting trophic niche partitioning and resource use within a community is critical to evaluate underlying mechanisms of coexistence, competition, or predation. Detailed knowledge about foraging is essential as it may influence the vital rates, which, in turn, can affect trophic relationships between species, and population dynamics. The aims of this study were to evaluate resource and trophic niche partitioning in summer/autumn between the endangered Atlantic‐Gaspésie caribou (Rangifer tarandus caribou) population, moose (Alces americanus) and their incidental predators, the black bear (Ursus americanus) and coyote (Canis latrans), and to quantify the extent to which these predators consumed caribou. Bayesian isotopic analysis showed a small overlap in trophic niche for the two sympatric ungulates suggesting a low potential for resource competition. Our results also revealed that caribou occupied a larger isotopic niche area than moose, suggesting a greater diversity of resources used by caribou. Not surprisingly, coyotes consumed mainly deer (Odocoileus virginianus), moose, snowshoe hare (Lepus americanus), and occasionally caribou, while bears consumed mainly vegetation and, to a lesser extent, moose and caribou. As coyotes and bears also feed on plant species, we documented trophic niche overlap between caribou and their predators, as searching for similar resources can force them to use the same habitats and thus increase the encounter rate and, ultimately, mortality risk for caribou. Although the decline in the Gaspésie caribou population is mostly driven by habitat‐mediated predation, we found evidence that the low level of resource competition with moose, added to the shared resources with incidental predators, mainly bears, may contribute to jeopardize the recovery of this endangered caribou population. Highlighting the trophic interaction between species is needed to establish efficient conservation and management strategies to insure the persistence of endangered populations. The comparison of trophic niches of species sharing the same habitat or resources is fundamental to evaluate the mechanisms of coexistence or competition and eventually predict the consequences of ecosystem changes in the community.

Stairway to heaven or highway to hell? How characteristics of forest roads shape their use by large mammals in the boreal forest

Decades of expansion of industrial resource extraction in boreal forests have resulted in the legacy of thousands of kilometers of linear features (seismic lines, forest roads) that have fragmented several wildlife habitats. The decommissioning of anthropogenic linear features and the restoration of suitable habitat are top priorities for the recovery of several species at risk, among which, the threatened populations of boreal caribou (Rangifer tarandus caribou). However, the decommissioning of linear features found in caribou range is expensive, and determining which characteristics make them more beneficial to caribou predators and competitors could assist in prioritizing those that may be most critical for boreal caribou habitat restoration. We thus aimed to determine how fine-scale forest road characteristics influence their use by gray wolf (Canis lupus), black bear (Ursus americanus), moose (Alces americanus) and caribou. We used camera traps and generalized linear mixed models to test the effect of road-scale characteristics on the use of forest roads by wolves, bears and moose while also considering larger-scale covariates. Wolves had a greater probability of using roads that were surrounded by wetlands and had a low lateral cover density. For bears, the intensity of use was lower on 20+ year-old roads when compared to 0–10-year-old roads, and higher on roads surrounded by coniferous stands. Moose intensity of use was higher on 11–20-year-old roads and lower on 30+ year-old roads, and decreased on roads surrounded by clearcuts and with a lower number of deciduous stems growing on them. We could not test for caribou use as we did not capture enough events. Nevertheless, by showing which forest roads are more used by caribou predators (wolves and bears) and its apparent competitor (moose), our study highlights the importance of considering both road-scale characteristics and the landscape context in which roads are built to prioritize the most detrimental roads to caribou conservation and guide efficient restoration efforts of its habitat.

Update of model for wild ruminant abundance based on occurrence and first models based on hunting yield at European scale

In a previous report, ENETWILD proposed a generic model framework to predict habitat suitability and likely occurrence for wild ruminant species using opportunistic presence data (occurrence records for wild ungulate species from the Global Biodiversity Information Facility). In this report, for the first time, we develop models based on hunting yield data (HY) for the most widely distributed wild ruminant species in Europe: roe deer (Capreolus capreolus) and red deer (Cervus elaphus). We also update models based on occurrence (roe deer, red deer, fallow deer (Dama dama), European moose (Alces alces) and muntjac (Muntiacus reevesi), evaluate the performance of both approaches, and compare outputs. As for HY models, we could not conduct one model per bioregion as there are not enough data for modelling in some bioregions, and therefore, we calibrated a unique model, including eco-geographical variables as predictors. The calibration plots for HY models showed a good predictive performance for red deer in the Eastern bioregion and roe deer at Eastern and Western. The abundance distribution pattern of red deer HY was widely scattered over all Europe, as expected for a widely distributed species which shows high ecological plasticity, and roe deer presented the highest abundance in Atlantic and Eastern Europe, progressively decreasing towards Northern Mediterranean bioregions. Overall, calibration plot did not perform well in the Northern region, which could be due to the low availability of data for both species in this bioregion. As for occurrence data models, performances using our revised approach for most species showed similarly moderate predictive accuracy. To sum, HY model projections showed good patterns where good quality data was provided, while worst predictions are found in neighbouring countries/bioregions. Two approximations to be explored for next models are: (i) modelling HY per bioregion providing more flexibility to the models, even if data projection is done at lower resolution scales, and (ii), modelling HY by accounting the fact that certain countries provide most data, to avoid that these areas overinform the model. As for occurrence data model, next steps for data acquisition and occurrence data modelling are: (i) review target group definitions for each species, (ii) revise definitions of “true” absence for model testing for better parity with fitting, and (iii) either replace principal component analysis with variance inflation factor analysis to remove co-correlates and model calibration for variable selection or develop post-model analysis to recover environmental dependencies.

Heterogeneous Fenton Degradation of Methyl Orange Using Fe–Al–Ce Bentonite As Catalyst

Heterogeneous Fenton Degradation of Methyl Orange Using Fe–Al–Ce Bentonite As Catalyst

Beneficial effects of Sc/Zr addition on hypereutectic Al–Ce alloys: Modification of primary phases and precipitation hardening

Al–Ce alloys possess desirable elevated-temperature performance due to the high stability of Al11Ce3 phases. The morphology and size of the Al11Ce3 phases play a significant role in determining the strengthening effect in Al–Ce alloys. In this paper, the effect of Sc/Zr addition on the microstructure, mechanical properties, and thermal stability of a hypereutectic cast Al–Ce alloy was investigated. The results demonstrated that Sc and Zr atoms could adsorb on the Al11Ce3 phase surfaces and control the growth process in the 0.13 wt % Sc-0.06 wt % Zr addition alloy, along with the size of primary Al11Ce3 phases was refined from ∼79 μm to ∼56 μm. As the total Sc/Zr content increased, the formation of primary Al3(Sc, Zr) phases could significantly refine the primary Al11Ce3 phases by acting as heterogeneous nucleation sites. Therefore, in 0.23 wt % Sc-0.16 wt % Zr and 0.49 wt % Sc-0.23 wt % Zr alloys, the modification effect on primary Al11Ce3 phases was based upon the interaction of adsorption effect and heterogeneous nucleation. The sizes of primary Al11Ce3 phases were refined to ∼37 μm and ∼32 μm, leading to a significant improvement in ultimate tensile strength (from ∼117 MPa to ∼182 MPa), yield strength (from ∼75 MPa to ∼145 MPa) and elongation (from ∼1.4% to ∼3.4%) in the 0.49 wt % Sc-0.23 wt % Zr alloy compared to the unmodified alloy. The Sc and Zr atoms that were dissolved in the matrix as a decomposed solid solution precipitated the L12-Al3(Sc, Zr) phases after thermal exposure, which maintained full coherency with the Al matrix, leading to a hardness increase, rather than a decrease, after 300 °C and 400 °C thermal exposure. Therefore, Al–15Ce-(Sc–Zr) alloys open a new alloy system for engineering materials useable in high-temperature applications.

Dental microwear foraging ecology of a large browsing ruminant in Northern Hemisphere: The European moose (Alces alces)

Years of studies have already highlighted the complex combination, in moose feeding ecology, of a marked selectivity coupled with a significant dietary adaptability toward changes in the local resource availability. Dental textures resulting from masticatory movements and the properties of ingested food items constitute a link between the animal, its ecology and the environment it occupies. This approach is efficient to decipher subtle variations in diet, at the interspecific but also intra-populational scales. In this study, we explore inter and intra population dietary variations among six Northern European moose populations using DMTA. We show that moose feeding ecology spans a continuum between a diet dominated by tender leaves and a diet consisting of lignified tissues. The structure of habitats is the main driver of these dietary differences between populations. The absence of significant variation between males and females or between seasons is interpreted as a reflection of the food selectivity of this deer on a finer scale. The moose has a long common history with humans, constituting at certain times and in certain places the main food resource of these populations, adapting in other contexts and at other times to the repercussions of increasing anthropization and global climate change. We aim here at characterizing the dental microwear texture diversity hidden within the “browsing” dietary category. This work is also intended to be used as a reference for future paleontological or archeological investigations. We believe that it will contribute to a better understanding of the(paleo)ecology of the species and of the variations in its feeding ecology through time.

Syngas production at a near-unity H2/CO ratio from photo-thermo-chemical dry reforming of methane on a Pt decorated Al2O3–CeO2catalyst

At 700 °C under 30-sun equivalent irradiation, the Pt–Al–Ce catalyst shows a high DRM efficiency and a near-unity H2/CO ratio. The concentrated sunlight facilitates photocatalytic reactant activation and leads to enhanced catalytic efficiency.

Microstructure and creep properties of cast near-eutectic Al–Ce–Ni alloys

This study investigates the as-cast and aged microstructures, thermal stability, ambient temperature strengthening, and creep resistance of three ternary Al–Ce–Ni alloys (wt%): near-eutectic Al–10Ce–5Ni (with both eutectic and hypoeutectic regions), hypoeutectic Al-7.5Ce-3.75Ni (with numerous primary Al dendrites), and hypereutectic Al-12.5Ce-6.25Ni (with coarse, blocky primary Al3Ni and Al11Ce3 precipitates and some primary Al dendrites). Depending on the alloy composition and local solidification conditions, the following eutectic morphologies are found: (i) coarse Al–Ce eutectic colonies where Al11Ce3 is in the form of “Chinese script”, (ii) intermingled regions of binary Al–Ce and Al–Ni eutectic colonies, with finer Al3Ni and Al11Ce3 fibers, (iii) large ternary eutectic colonies, where the binary Al3Ni and Al11Ce3 phases are alternating or intertwining within the individual, fine fibers (diameters of ∼60–170 nm, depending on solidification rates), and (iv) ternary eutectic zones (between primary Al dendrites), where fine Al3Ni and Al11Ce3 build up a 3D-interconnected network. The high volume fraction of intermetallic phases and extremely fine eutectic spacing/fiber diameter both contribute to high ambient strengthening (higher as-cast microhardness than binary Al–Ce or Al–Ni), and also provide enhanced creep resistance at 300 and 350 °C. The alloys are coarsening-resistant up to 425 °C for extended periods, with a gradual decrease in microhardness. The alloys aged at 400 °C to 1050 h show fiber fragmentation and coarsening of the resulting particles, with the faster-diffusing Ni driving more rapid coarsening of the Al3Ni particles which engulf finer, more stable Al11Ce3 particles. Severe overaging (performed at 590 °C for 24 h) leads to Al3Ni and Al11Ce3 spheroids which remain submicron-sized in eutectic colonies, but micron-sized at colony boundary and at Al dendrite-eutectic interface. Creep resistance at 300 °C of overaged Al–10Ce–5Ni remains substantial, consistent with load-transfer based composite strengthening being an important strengthening mechanism in these alloys, making them excellent candidates for replacement of heavier steel or titanium parts operating under stress up to 300 °C.

Al–Ca, Al–Ce, and Al–La Eutectic Aluminum Alloys Processed by High‐Pressure Torsion

A systematic study of structure and hardening of two‐phase Al–8% Ca, Al–10% Ce, and Al–10% La eutectic aluminum alloys under high‐pressure torsion (HPT) has been carried out. HPT leads to an increase in microhardness as a result of the formation of a nanocrystalline structure with a high density of crystal defects in the Al–8% Ca alloy and a nano‐ and submicrocrystalline structure with a low density of crystal defects in the Al–10% Ce and Al–10% La alloys, as well as the eutectic particle refinement in all alloys. The predominant crystallite sizes after HPT through five turns are 70–210, 60–120, and 25–45 nm, respectively, in the Al–10% La, Al–10% Ce, and Al–8% Ca alloys. The change in the shape of the curve of the microhardness distribution over the samples’ surface with an increase in the number of turns from 1 to 5 is different for three alloys. The results demonstrate the ultrafine‐grained microstructure development varied depending on the binary alloy systems. Initial as‐cast eutectic particles have a significant effect on the structure and hardening of alloys through their morphology, volume fraction, hardness, and orientational ratio with the aluminum base.

The salt licking activity of the European Moose (Alces alces Linnaeus, 1758) in the Leningrad region of Russia: temporal and behavioral aspects

The salt licking activity of the European Moose (Alces alces Linnaeus, 1758) in the Leningrad region of Russia: temporal and behavioral aspects