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Based on analytical materials obtained in 2008 an the expedition of the R/V Akademik M.A. Lavrentiev along a regional gas-geochemical profile stretching 550 km from Billings Cape towards the underwater Mendeleev Ridge, the formational features in the composition of bottom sediment (pelitic aleurites and aleuritic pelites) in the eastern part of the East Siberian Sea were reconstructed. It was found that the studied set of samples for the Cr/Th, Th/Co, La/Sc values, as well as Eu/Eu* and (Eu/Sm)N values, consists of two groups. The first group includes samples recovered at stations 70–350 of the gas-geochemical profile. The second group includes samples recovered at stations 370–560. On the (La/Yb)N–Eu/Eu* and (La/Yb)N–(Eu/Sm)N diagrams, the sample data points are concentrated in the overlap zone of the compositional areas of aleuritic–pelitic sediments of large rivers and rivers, fed mainly by the erosion products of sedimentary rocks. The distribution of the data points of bottom sediments on these diagrams, as well as on the (La/Yb)N–Th diagram, differs from the distribution of data points for the Neoproterozoic amphibolites, granitoids, and rhyolites of Wrangel Island; therefore, the latter most likely could not have been sources of fine-grained aluminosiliciclastic material. The samples of the first group are quite close to the surface sediments of the East Siberian Sea in their Eu/Eu* and (Eu/Sm)N values and a number of other parameters. In contrast, the samples of the second group are closer to the bottom sediments of the Chukchi Sea. Apparently, the bottom sediments northwest of Wrangel Island formed under the influence of currents carrying fine-grained aluminosilicoclastic material from the Chukchi Sea. West of Wrangel Island, sediment composition is controlled mainly by material coming from the western and central regions of the East Siberian Sea.

An original method is proposed for rapidly differentiating between regional pink salmon runs with different timings of spawning and states of gonads (gonadosomatic indices, GSI). The results of differentiation obtained by the original and traditional methods are compared. The concept of spatial niches for various temporal groups of Sea of Okhotsk pink salmon in Pacific waters off the Kuril Islands is critically revised on the basis of the proposed new method. The existing concept is based on the traditional use of certain numerical markers (GSI) for samples at the sites of trawl hauls. The width of the spatial overlap zone in the distribution of temporal groups is shown. The method was tested using data of trawl surveys conducted aboard the R/V Professor Kaganovsky in May–July 2018, during the anadromous migration of pink salmon. It shows high agreement with the estimates of the proportions of the contribution that the regional pink salmon groups make to the runs and catches according to the official statistics on fishing and the escapement of spawners to rivers. The assumption on the tendency of the late-maturing pink salmon forms to migrate through the southern part of Pacific waters off the Kuril Islands is confirmed. The specific (along transects) and cumulative portion of early-maturing pink has been shown to increase with distance off the Kuril straits into Pacific waters.

At present, the research results on the stability and reinforcement range of the subgrade when the high-speed railway traverses the edge of a large goaf are still scarce. Taking Guinan high-speed railway traversing the edge of the mined-out area of the Dapan well as the research object, high-speed rail load transfer depth and height of goaf impact were analyzed, Researching the stability of high-speed railway subgrade and the reinforcement range of goaf. The results show that Mined-out edge cracks more obvious development, High-speed railway subgrade at the edge of the goaf is more harmful than when located directly above the goaf; On the No.1 well goaf, the overlap zone between the height of the caving fissure zone and the depth of influence of the high-speed railway load appears, but the height of the goaf in the extremely soft rock will extend to the surface; The high-speed railway subgrade is mainly affected by the residual deformation of the gob of the Dapan well. At last, the reasonable reinforcement range is given through the finite element numerical calculation.

The adhesive bonding process is widely used in the automobile industry because of sealing, insulation and good mechanical properties. In this study, the effects of surface treatments and joint parameters on shear strength and failure mode were investigated. Four different sandpaper treatments, overlap length and adhesive thickness were selected to carry out quasi-static shear test. The failure behaviour of aluminium alloy single-lap adhesive joints was analysed and a dimensionless parameters δ was introduced to quantitatively evaluate the effect of overlap length on joint strength. Results showed that the joint strength was enhanced by sandpaper grinding due to the change of surface roughness. The specimens with 90°/0° grinding direction using P360 sandpaper had the best performance rather than an excessively rough surface. The joint shear strength decreased with the increase of adhesive thickness but the effect of overlap length on joint strength was limited. The adhesive thickness had little impact on joint shear strength when the overlap length over 40 mm. In addition, the joint strength could be improved by increasing overlap length until δ below 0.95. However, with the decrease of δ, there was almost no effect on joint strength because of high peeling stress at the both ends of the long joints.

Albinism is a congenital disorder where misrouting of the optic nerves at the chiasm gives rise to abnormal visual field representations in occipital cortex. In typical human development, the left occipital cortex receives retinal input predominantly from the right visual field, and vice-versa. In albinism, there is a more complete decussation of optic nerve fibers at the chiasm, resulting in partial representation of the temporal hemiretina (ipsilateral visual field) in the contralateral hemisphere. In this study, we characterize the receptive field properties for these abnormal representations by conducting detailed fMRI population receptive field mapping in a rare subset of participants with albinism and no ocular nystagmus. We find a nasal bias for receptive field positions in the abnormal temporal hemiretina representation. In addition, by modelling responses to bilateral visual field stimulation in the overlap zone, we found evidence in favor of discrete unilateral receptive fields, suggesting a conservative pattern of spatial selectivity in the presence of abnormal retinal input.

The element/phase loss is undesirable but existing during selective laser melting (SLM) of materials with volatile element/phase, which not only changes the material composition but also affects the molten pool flow. In the previous researches, the effect of remelting on the element/phase loss was neglected during the SLM process, instead, laser energy density was thought to be uppermost. In fact, the SLM process fabricates the parts in a manner of line by line and layer by layer, i.e., additive character, and the remelting in the overlap zone occurs during the SLM process. In this paper, three different Al2O3 loss prediction models of SLM Al2O3–Al composite by considering the additive character of SLM and the distribution of the Al2O3 associated with the different molten pool driving forces were developed. By comparing with the experimental results and predicted results, it is found that the Al2O3 is distributed on both sides of the molten pool under the combined action of the Marangoni flow and the evaporation recoil pressure. This kind of Al2O3 distribution enhances the effect of the remelting on the Al2O3 loss, i.e., the remelting brings a logarithmic increase in the Al2O3 loss rate. This determines the final Al2O3 loss rate of the SLMed 3D samples. During this study, although the Al2O3 loss rate of the single-track is only 33%, the loss rate of SLMed 3D samples increases significantly to 97% when the hatching space of 60 μm and scanning speed of 200 mm/s are utilized, i.e., almost no Al2O3 in the 3D sample. Thus, it is more important to reduce the remelting, i.e., overlap rate for reducing the element/phase loss. This study is a benefit for understanding and reducing the element/phase loss in SLM.

Dissertação de Mestrado Integrado em Engenharia Mecânica apresentada à Faculdade de Ciências e Tecnologia O interesse pela soldadura laser de metais dissimilares, para a produção de componentes de transmissão, tem vindo a aumentar no seio da indústria automóvel, uma vez que permite aliar excelentes propriedades e requisitos de projeto a custos reduzidos. As juntas dissimilares, apesar de atenderem a requisitos de projeto complexos, apresentam problemas de soldabilidade, relacionados com as diferenças nas propriedades físicas, químicas e mecânicas dos metais envolvidos na ligação.No fabrico das caixas de velocidades, é utilizada a ligação por soldadura para acoplar a coroa à caixa diferencial. A coroa é fabricada em aço 27MnCr5 sujeito a um tratamento térmico super profundo de carbonitruração. A caixa diferencial é maquinada em ferro fundido dúctil, FCS 600-3. O material de adição utilizado é uma liga de crómio-níquel, NiCr20Mn3Nb.Este estudo tem como objetivo otimizar o processo de soldadura laser das caixas diferenciais, bem como avaliar o fluxo de hidrogénio difusível no aço, antes de este ser soldado. O cordão de soldadura estudado apresenta uma geometria circular, havendo uma zona de sobreposição, designada por zona do recobrimento. Esta zona foi identificada como crítica e de elevada contribuição para o fenómeno da fissuração a frio, pelo que foi realizado um plano de ensaios recorrendo à soldadura de várias amostras e testando diferentes parametrizações do sistema de alimentação do material de adição. As amostras foram inspecionadas através de ultrassons e, posteriormente, recorrendo à análise destrutiva.Relativamente ao fluxo de hidrogénio difusível no aço, este foi medido durante o tratamento térmico de revenido com a finalidade de avaliar se o hidrogénio se difunde para o exterior do material durante o revenido, como é que essa difusão reage ao aumento da temperatura e se a duração de 3h de revenido é suficiente para reduzir o nível de hidrogénio abaixo do nível considerado crítico para evitar a fissuração a frio.Com a realização desta investigação foi possível concluir que a zona do recobrimento é propícia ao surgimento de defeitos de soldadura, nomeadamente fissuras. Conclui-se ainda que grandes quantidades de hidrogénio são absorvidas pelo aço durante o tratamento térmico de carbonitruração, que depois é libertado durante o revenido. Contudo, ao fim de 3h de revenido o fluxo de hidrogénio é superior a 1000 pL/s, que ainda assim, é prejudicial e favorece a fissuração a frio. The interest in laser welding of dissimilar metals, to produce transmission components, has been increasing within the automotive industry, since it allows to combine excellent properties and design requirements at reduced costs. Dissimilar joints, despite meeting complex design requirements, presents weldability problems related to differences between physical, chemical and mechanical properties of the metals involved in welded joint.In the manufacture of gearboxes, welding is used to attach the crown to the differential housing. The crown is made of 27MnCr5 steel subject to a carbonitriding heat treatment. The differential case is machined in cast iron, FCS 600-3. The filler material used is a chromium-nickel alloy, NiCr20Mn3Nb.This study aims to optimize the laser welding process of the differential boxes, as well as to evaluate the flux of diffusible hydrogen in steel before welding. The welding bead studied presents a circular geometry with an overlap zone. This area was identified as critical with a high contribution to the phenomenon of cold cracking, so a test plan was carried out using the welding of several samples and testing different parameterizations of the feeding system of the filler material. The samples were inspected by ultrasound and subsequently using destructive analysis.The diffusible hydrogen flux in steel was measured during tempering for the purpose of assessing whether hydrogen diffuses to the outside of the material during heat treatment, how this diffusion reacts to the temperature increase and whether the duration of 3h of tempering is sufficient to reduce the level of hydrogen below the level considered critical to avoid cold cracking.With this investigation, it was possible to conclude that the overlap zone is prone to the appearance of welding defects, more precisely, cold cracks. It is also concluded that large amounts of hydrogen are absorbed by steel during the heat treatment of carbonitriding and that it is then released during tempering. However, after 3 hours of tempering the hydrogen flux is greater than 1000 pL/s, which is prone to cold cracking.

Video retrieval using natural language queries requires learning semantically meaningful joint embeddings between the text and the audio-visual input. Often, such joint embeddings are learnt using pairwise (or triplet) contrastive loss objectives which cannot give enough attention to ‘difficult-to-retrieve’ samples during training. This problem is especially pronounced in data-scarce settings where the data is relatively small (10% of the large scale MSR-VTT) to cover the rather complex audio-visual embedding space. In this context, we propose to compensate for data scarcity by using domain knowledge to augment supervision. Specifically, in addition to the conventional three samples of a triplet (anchor, positive, and negative), we introduce a fourth term - a partial - to define a margin based partial-order loss. The partials are heuristically sampled such that they semantically lie in the overlap zone between the positives and the negatives, thereby resulting in broader embedding coverage. Our proposals consistently outperform the conventional max-margin and triplet losses and improve the state-of-the-art on MSR-VTT and DiDeMO datasets. To further evaluate our method in data-scarce and low-resource setting, we introduce Rudder - a multilingual video-text retrieval dataset that includes audio and textual captions in Marathi, Hindi, Tamil, Kannada, Malayalam and Telugu. We report benchmark results on Rudder while also observing significant gains using the proposed partial order loss, especially when the language specific retrieval models are jointly trained by availing the cross-lingual alignment across the language-specific datasets.1

An overlap auxiliary ventilation system is very often used for driving roadways in methane-rich coal seams. An overlap zone between the outlets of the forcing duct ends with a whirl flow air-duct (WFAD) and the exhaust duct ends with a dust scrubber that is created by applying the overlap system. This study examines the distribution of methane concentrations at various distances in the overlap zone. Maintaining a long overlap zone could increase the advance of the face. Therefore, the impact of overlap zone length on the methane concentration distribution, in and beyond the overlap zone, is investigated. The evaluation of methane concentrations is performed utilizing a well-established computational fluid dynamics (CFD) approach. The mathematical model of methane emissions into the roadway is adopted. Moreover, the CFD model is validated. A vortex of the return air, caused by the free airstream flowing out of the dust scrubber, is found. This air vortex is responsible for higher methane concentrations at the end of the overlap zone. Therefore, the conclusion can be drawn that maintaining the length of the overlap zone at 5 m to 10 m should be done to control permissible methane concentrations.

The evolutionary and population demographic history of marine red algae in East Asia is poorly understood. Here, we reconstructed the phylogeographies of two upper intertidal species endemic to East Asia, Gelidiophycus divaricatus and G. freshwateri. Phylogenetic and phylogeographic inferences of 393 mitochondrial cox1, 128 plastid rbcL, and 342 nuclear ITS2 sequences were complemented with ecological niche models. Gelidiophycus divaricatus, a southern species adapted to warm water, is characterized by a high genetic diversity and a strong geographical population structure, characteristic of stable population sizes and sudden reduction to recent expansion. In contrast, G. freshwateri, a northern species adapted to cold temperate conditions, is genetically relatively homogeneous with a shallow population structure resulting from steady population growth and recent equilibrium. The overlap zone of the two species roughly matches summer and winter isotherms, indicating that surface seawater temperature is a key feature influencing species range. Unidirectional genetic introgression was detected at two sites on Jeju Island where G. divaricatus was rare while G. freshwateri was common, suggesting the occurrence of asymmetric natural hybrids, a rarely reported event for rhodophytes. Our results illustrate that Quaternary climate oscillations have left strong imprints on the current day genetic structure and highlight the importance of seawater temperature and sea level change in driving speciation in upper intertidal seaweed species.

This paper addresses the main problems in assessing the stratigraphy of superimpositions in rock art. When a petroglyph is overlain by one or several others, this may provide important information not only about single images but also about entire stylistic traditions. Existing methods used for evaluating the relative chronology of the parts of petroglyphic palimpsests are discussed, and a new approach is proposed, combining high-resolution three-dimensional visualization at the macro-level with traceological analysis. We focus on the characteristics of the pecked surface in the area outside the palimpsest and that in the overlap zone. The comparison of these parts makes it possible to reveal the traceologically informative features in the palimpsest areas, indicating the sequence of superimposed petroglyphs. This approach is instantiated by the analysis of one of the palimpsests in the Shalabolino rock gallery, the Krasnoyarsk Territory. Images representing various stylistic traditions are found in complicated stratigraphic relations. The sequence of three main fi gures (bear, bull, and elk) in this multilayered composition has been reconstructed. The results of the analysis cannot be used as an argument for attributing these petroglyphs to vastly different chronological periods. Rather, they provide new information relevant to the debate around the age of the Angara and Minusinsk petroglyphic styles in the Minusinsk Basin.

Aim : to аББевв dranges in liver pаrenсhymа in the еаг1у, tate аnd remote postoperative periods аfter сryodestruсtion (CD) of foсаl lesions by MRI with diffusion-weighted images (DWI). Mаteriаls аnd methods . Postoperative MRI monitoring wаs саrried out in 15 pаtients with mаlignаnt liver lesions. All pаtients were divided into two groups: with сomplete аnd inсumplete CD. All pаtients underwent MRI with dWi before surgery аnd in the postoperative period on the 1st dаy, 3 months, 6 аnd 12 months. Results. In group 1 - 100% “overlаp” of the pаthologiсаl foсus агеа of postoperative edemra ассording to T1WI аnd T2WI. Before surgery ~ ADC in the foсus wаs 0.86 mm 2 /s, in the 1st dаy - 1.00 mm 2 /s, 3 months - 1.03 mm 2 /s, 6 months - 1.30 mm 2 /s, 12 months - 1.30 mm 2 /s. Before surgery, the average size of the focus - 46 mm, in the 1st day - 57 mm, 3 months - 46 mm, 6 months - 45 mm, after 12 months - 39 mm. By the 12th month in group 1 ~ ADC in the focus increased by 51.20%, and the average size of the focus decreased by 16.00%. In group 2 - incomplete overlapping of the focus area of postoperative edema. Before surgery ~ ADC in the focus was 0.80 mm 2 /s, in the 1st day - 0.79 mm 2 / s, in 3 months -0.75 mm 2 /s, in 6 months - 0.66 mm 2 /s, in 12 months -0.55 mm 2 /s. Before surgery, the average size of the focus -44 mm, in the 1st day - 47 mm, in 3 months - 55 mm, in 6 months - 78 mm, after 12 months - 112 mm. 12 months after CD group 2 ~ ADC in the focus decreased by 31.30%, and the average size of the focus increased by 155.20% due to the continued growth of the tumor. Conclusion. MRI with DWI allows to assess changes in the liver and CD zone in the early, late and remote postoperative periods, to assess the completeness of the overlap zone of the CD focus and the dynamics of the continued growth of the tumor after incomplete CD.

The crack-free H13 block was deposited through additive manufacturing with the cold metal transfer technology. The internal 3D pore distribution, the microstructural evolution, and the mechanical performances were explored. A negligible porosity with dispersive-distribution and spherical-shape below 0.001% guaranteed a sound metallurgical bonding within the as-deposited part. The martensite laths growth direction varied dramatically with a very short position variation, as well as the block-like size-inconsistent δ-ferrite presence in the overlap zone, which were mainly generated by the thermal flux direction from the center to margin within a single arc track. Massive second-phase particles with morphology-diversity and size-nonuniformity were precipitated, indicating a strong dependency with the intrinsic heating treatment. The enhanced microhardness in the body zone was attributed to the martensite strengthening mechanism, while slightly low hardness was produced due to the soft δ-ferrite formation. When compared with the other zones, the enhanced ultimate tensile strength was obtained in the body zone at the expense of tensile ductility, revealing a positive relationship with the rise of hard martensite percentage. This work demonstrated that a crack-free H13 block with limited porosity and desirable mechanical properties was deposited using the present technology, despite the nonhomogeneous microstructures.

Purpose: There are several commercially approved stent grafts in Korea for the treatment of abdominal aortic aneurysms (AAAs). Each device has its advantages and disadvantages based on the patient’s anatomy and the clinical situation. The Zenith device allows accurate and precise endograft placement, whereas the Endurant device has improved flexibility and trackability. We reviewed 5 cases in which a combination of the Zenith main body and the Endurant iliac limb was used. Materials and Methods: From January 2010 to February 2015, 90 patients with AAA underwent endovascular aneurysm repair (EVAR) using the Zenith body at Daegu Catholic University Hospital. Among them, 5 patients who underwent EVAR with the Zenith body and Endurant iliac limb were included in this study. Results: The mean age of the patients was 74.20±3.35 years. All patients were men. The main reason for use of the Endurant iliac limb was aortoiliac angulation. Type III endoleak, stent migration, and stent kinking were not noted. Comparing 85 patients who received a Zenith endograft with 5 patients who received the hybrid endograft, there were no statistical differences in clinical characteristics, intraoperative details and post procedural complications. The mean admission duration was 19.00±13.60 days, and the mean follow-up duration was 1,018.11±925.34 days. In the hybrid endograft group, there was no mortality during the follow-up duration. Conclusion: Although the material, radial force, diameter, and length of the overlap zone differ between the two devices, EVAR with the hybrid endograft is safe and effective.

The tungsten inert gas welded P91 steel welded joints were subjected to the two different type of heat treatments including the postweld direct tempering (PWDT) and re-austenitizing based tempering (PWNT) treatment. The microstructure of weld fusion and heat affected zone (HAZ) were characterized in different heat treatment conditions using optical microscope and scanning electron microscope. For as-welded joint, a great heterogeneity was observed in microstructure and mechanical properties across the weldments. The Charpy toughness of the as-welded joint was measured much lower than the minimum recommended value of 47 J and it was measured 8 ± 5 J. The PWHTs have found a beneficial effect in decreasing the microstructure heterogeneity across the welded joint and improving the mechanical properties. The PWDT resulted in a drastic improvement in the Charpy impact toughness of the welded joint and it was measured 59 ± 5 J which was higher than the minimum required value of 47 J but still inferior than the base metal. The δ ferrite still remained in overlap zone of the weld fusion zone. The PWNT treatment resulted in homogeneous microstructure and hardness variation across the welded joint in transverse direction and Charpy impact toughness (149 ± 6 J) exceeded than that achieved in base metal.

Electron Beam Melting (EBM), one of the powder bed-based additive manufacturing processes that is able to produce complex geometrical metal parts directly, has many application possibilities in various fields. However, an issue has been raised when we apply the EBM technology to fabricate medium volume components. Lack of energy when the scanning line is longer than 100 mm results in the lack-of-fusion pores, which degrades the mechanical properties of the printed part dramatically. Therefore, we propose an in situ welding process to overcome the issue. In order to further understand the microstructure and mechanical properties resulting from the in situ welded process with various overlap distances, we evaluate a series of overlap distances and successfully fabricate a big plate with dimensions of 200 × 200 × 4 mm3. It is suggested that the defects and microstructure vary according to the overlap distance. Optimized overlap distances are 0.25–0.75 mm for Ti-6Al-4V. Within this range, no microstructural variation is observed which results in constant microhardness and superior mechanical properties of the EBM-built component. An overlap distance ≥1.5 mm results in microstructure coarsening and mechanical property degradation in the overlap zone. Furthermore, the localized deformation mechanism is discussed based on the findings of the tensile properties and digital image correlation analysis.

To investigate the influence of island scanning on the microstructures and mechanical properties of direct laser-deposited Ti–6Al–4V structures, two samples are prepared using island scanning and orthogonal successive scanning, respectively. The microstructures, relative density, and mechanical properties of the samples prepared using these two scanning strategies are compared. Each sample exhibits columnar β-grain morphology and basket-weave microstructure characterization. The grains of the sample prepared using island scanning are significantly finer than that prepared by orthogonal successive scanning due to faster cooling during deposition. However, the relative density of the sample prepared using island scanning was slightly smaller due to the concentration of lack-of-fusion pores at the overlap zone of the island. Tensile testing at room temperature indicates that the ultimate tensile strength and yield strength of the sample prepared using island scanning is enhanced due to finer grains, while the ductility of the sample is weakened due to defects.

The existing phonon Monte Carlo (MC) for ballistic-diffusive heat conduction are limited to small and simple structures owing to the huge time cost following with the increasing scale. This article presents a new hybrid phonon Monte Carlo-diffusion method for ballistic-diffusive heat conduction, which successfully characterizes the ballistic effect with significantly reducing the computational cost. Based on the idea that the phonon-boundary scattering mainly affects the regions adjacent to the boundaries when the system is considerably large, the whole system is divided into three zones: the boundary MC zone and the middle diffusion zone, between which is the overlap zone. By using an alternating method and setting virtual phonon bath or specular reflection as the boundary condition for the MC zones, the results of the phonon tracing MC and diffusion equation can be coupled and converge at the overlap zone. To verify, the cross-plane and in-plane film heat conduction, where slip boundary conditions are the major characteristics of the ballistic-diffusive regime, are simulated by the hybrid method as well as standard phonon tracing MC which works as a benchmark. It is found that the hybrid method can accurately predict the distributions of temperature and heat flux in the system with nearly the same precision as the phonon tracing MC while the computation time can reduce up to 90%, validating its potential use for larger and more complex structures.

The Green Odorous Frog (Odorrana margaretae) around the Sichuan Basin of western China displays a ring-shaped distributional pattern and possesses multiple replicate contact zones between lineages at various levels of differentiation. To understand its unique speciation history and mechanisms, we obtained 1,540 SNPs from 29 populations and 227 individuals using ddRAD sequencing. Population structure analysis revealed three groups within the species: The West, the North & South, and the East groups. These groups were initially isolated at ~2.03 million years ago, and subsequent post-glacial expansion produced the current ring-shaped distribution around Sichuan Basin with three contact zones. Hybridization in those zones involved lineages with different levels of divergence and produced greatly different outcomes. Both the hybrid zones at southwest (S-W) and southeast (E-NS) of the Basin have extensive admixture and less barrier effect. Consequently, the southern region has the highest genetic diversity and becomes an ‘evolutionary melting pot’. In contrast, the hybrid zone at northwestern corner (N-W), which resembles the overlap zone between two expansion terminals of a ring species, has limited admixture with a narrow geographic cline, suggesting partial reproductive isolation between the northern and western populations. The three hybrid zones likely resemble three time points along a speciation continuum; while both E-NS and S-W hybrid zones are merging, the N-W zone may have passed the ‘tipping point’ and is destined for a complete reproductive isolation over time.

Muscle contraction activated by calcium ion is the key to reveal that honeybee abdomen can achieve various physiological activities through flexible exercises and contributes to a powerful mechanical function of muscle fibers. To investigate the stimulating effect of calcium ion on muscle fibers of honeybee abdomen, atomic force microscopy was used to measure the morphology structure and mechanical properties of muscle fibers from honeybee abdomen in different calcium ion solutions. The periodic morphology structure of muscle fibers stimulated by different calcium ion concentration changed greatly, and the sarcomere length contracted from 6.53 μm to 4.29 μm as the calcium ion concentration increased from 0.11 mM to 10 mM. The mechanical measurement showed that the elastic modulus of Z-line reached the maximum, followed by M-line, overlap zone and I-band in sequence at the same calcium ion concentration, and was approximately 3.636, 2.450, 2.284, 2.748 times that of I-band from 0.11 mM to 10 mM calcium ion concentration. Combining the experimental analysis, the calcium ion threshold range was obtained based on the response surface method. This work adequately elucidates biological structure and biomechanics of muscle fibers from honeybee abdomen and could provide reference for other similar muscle system.

This study presents a unique melting strategy in electron beam-powder bed fusion of Alloy 718 to tailor the grain morphology from the typical columnar to equiaxed morphology. For this transition, a specific combination of certain process parameters, including low scanning speeds (400-800 mm/s), wide line offsets (300-500 mu m) and a high number of line order (#10) was selected to control local solidification conditions in each melt pool during the process. In addition, secondary melting of each layer with a 90. rotation with respect to primary melting induced more vigorous motions within the melt pools and extensive changes in thermal gradient direction, facilitating grain morphology tailoring. Four different types of microstructures were classified according to the produced grain morphology depending on the overlap zone between two adjacent melt pools, i.e., fully-columnar (overlap above 40 %), fully-equiaxed (overlap below 15 %), mixed columnar-equiaxed grains, and hemispherical melt pools containing mixed columnar-equiaxed grains (overlap similar to 20-25 %). The typical texture was ; however, the texture was reduced significantly through the transition from the columnar to equiaxed grain morphology. Along with all four different microstructures, shrinkage defects and cracks were also identified which amount of them reduced by a reduction in areal energy input. The hardness was increased through the transition, which was linked to the growth of the.” precipitates and high grain boundary density in the fully-equiaxed grain morphology. Funding from the “European Regional Development Fund,” the “Simulation and Control of Material affecting Processes” (SiCoMap), and the “Sustainable Manufacturing Through Next-Generation Additive Process” (SUMAN-Next) projects, with funding from the KK foundation, are highly acknowledged

The aim of this study is to develop the retrofitting details, which will increase axial ultimate load capacity, stiffness, displacement ductility ratios, and energy dissipation capacities of short reinforced concrete (RC) low-slenderness columns to avoid adverse effects on earthquake performance. The main variables examined in the experimental study are the Carbon Reinforced Fiber Polymer (CFRP) strip width used for retrofitting, the distance between CFRP strips, the use of the anchor at the overlap zone in the CFRP strips, and the placement of the CFRP strips horizontally or vertically to the column axis. For these purposes, eleven square short RC columns with a dimension of 150x150x500 mm (with low slenderness ratio: λ = 11.5) were produced. The columns were damaged up to 50% of their axial load carrying capacity, then retrofitted with CFRP strips in different ways. The short RC columns with low slenderness ratio were tested under monotonic axial loading until they failure. By obtaining the axial load–displacement graphs of the test specimens, the ultimate axial load capacity, initial stiffness value, displacement-ductility ratios, and energy dissipation capacities are calculated and interpreted. It has been found that the most successful retrofitting detail is obtained when CFRP strips are placed perpendicular to the column axis, and CFRP fan-type anchors are used in the strip overlap region.

Collagen type I is one of the major structural proteins in mammals, providing tissues such as cornea, tendon, bone, skin, and dentin with mechanical stability, strength, and toughness. Collagen fibrils are composed of collagen molecules arranged in a quarter-stagger array that gives rise to a periodicity of 67 nm along the fibril axis, with a 30 nm overlap zone and a 37 nm gap zone. The formation of such highly organized fibrils is a self-assembly process where electrostatic and hydrophobic interactions play a critical role in determining the staggering of the molecules with 67 nm periodicity. While collagen self-assembly has been extensively studied, not much is known about the mechanism, and in particular, the nature of the nuclei that initially form, the different stages of the aggregation process, and how the organization of the molecules into fibrils arises. By combining time-resolved cryo-transmission electron microscopy with molecular dynamics simulations, we show that collagen assembly is a multistep process in which the molecules first form filaments which self-organize into fibrils with a disordered structure. The appearance of the D-band periodicity is gradual and starts with the alignment of adjacent filaments at the N-terminal end of the molecules, first leading to bands with a periodicity of 67 nm and then to the formation of gap and overlap regions.

Mechanical properties, including tensile properties and fatigue crack growth behaviors, and their relationships with macrostructures at different thickness positions in plates of laser melting deposited Ti–5Al–5Mo–5V–1Cr–1Fe, are experimentally investigated in this paper. It is observed that there display obvious differences in macrostructure features between overlap zones and non-overlap zones along thickness direction, which leads to anisotropies and heterogeneities of tensile properties including yield stress, tensile strength and total elongation. In fatigue crack growth tests with thin compact tension specimens at different thickness positions, crack paths are deviated from mode I with varying angles and fatigue crack growth rates display obvious fluctuations, which are mainly caused by the macrostructure features in overlap zone. In the end, evaluation methods are discussed for fatigue crack growth behaviors from the perspective of mechanics-materials interactive mechanisms, which helps strive for the future processing-material-structure-property-evaluation paradigm for additively manufactured metal structures.

The Fabric Reinforced Cementitious Matrices (FRCMs) and Steel Reinforced Grout (SRG) are a promising strengthening solution for existing masonry since inorganic matrix is considerably compatible with historical substrates. The present paper is focused on a Finite Element (FE) analysis of masonry columns confined with FRCM composites developed by Abaqus-code. The masonry columns were modelled using a macro model approach. The model was performed by using the following functions Concrete Damage Plasticity (CDP) and the Plastic (P) in order to describe the constitutive laws of material for masonry columns and external reinforcement, respectively. Typical failures of FRCM-systems are slippage of the fibers within the embedding matrix, instead for SRG-systems are detachment of the composite strip at the fabric-matrix interface and fiber rupture. In addition, perfect bond was considered for the interaction between the masonry column and in the overlap zone the bond slip law was modelled on the base of the failure mode. Results of an experimental investigation on FRCM and SRG clay brick masonry columns are used to calibrate the numerical model.

Laser cladding represents an advanced repair and modification technology for the failed parts and high-performance parts of controlled the surface onto the needing area. When the cylinder geometry or complex geometry which has circular and partition fusion is required, maybe there appears an overlap in poles of the laser clad track and linear or circular clad edge zone, and in Start/Stop zone of the laser clad track. When the distance of the overlap is not attached importance, the unsuitable height of the overlapping region may result in the defect of the coatings and even the failure of the parts. This paper establishes T-shape overlapping model and Start-Stop overlapping model, and reports several overlap strategies that are used to verify the model and tested to solve the overlapping problem. The 500W IPG fiber laser was used to perform laser cladding experiments, 45 steel substrate size: 100 × 100 × 10 mm and coating powder: YCF101 alloy powder. 3D measuring laser microscope was used to study the height of overlapping zone by different overlapping strategies. These strategies were designed according to different combinations of the poles and clad edge. Coating height inside the overlap zone was identified and overlapping formula was verified for YCF101alloy.

This paper presents the experimental results of a study on the occurrence of debonding along the overlap length of fiber reinforced polymer (FRP) confined concrete prior to rupture of the FRP jacket. Plain concrete cylinders, twenty-six with 152 mm diameter and 305 mm height, and four with 100 mm diameter and 200 mm height, with cylinder compressive concrete strength 19 MPa, were wrapped with carbon- and glass-FRP jackets and tested under monotonic axial compression. Different overlap configurations and different FRP application methods were investigated. The parameters found to most significantly affect the bond resistance along the overlap zone are the type of the FRP material and the curing age of the resin when dry lay-up application is used.

The mechanical evolution of transpression zones affected by fault interactions is investigated by a 3D elasto-plastic mechanical model solved with the finite-element method. Ductile transpression between non-rigid walls implies an upward and lateral extrusion. The model results demonstrate that a, transpression zone evolves in a 3D strain field along non-coaxial strain paths. Distributed plastic strain, slip transfer, and maximum plastic strain occur within the transpression zone. Outside the transpression zone, fault slip is reduced because deformation is accommodated by distributed plastic shear. With progressive deformation, the σ3 axis (the minimum compressive stress) rotates within the transpression zone to form an oblique angle to the regional transport direction (∼9°–10°). The magnitude of displacement increases faster within the transpression zone than outside it. Rotation of the displacement vectors of oblique convergence with time suggests that transpression zone evolves toward an overall non-plane strain deformation. The slip decreases along fault segments and with increasing depth. This can be attributed to the accommodation of bulk shortening over adjacent fault segments. The model result shows an almost symmetrical domal uplift due to off-fault deformation, generating a doubly plunging fold and a ‘positive flower’ structure. Outside the overlap zone, expanding asymmetric basins subside to ‘negative flower’ structures on both sides of the transpression zone and are called ‘transpressional basins’. Deflection at fault segments causes the fault dip fall to less than 90° (∼86–89°) near the surface (∼1.5 km). This results in a pure-shear-dominated, triclinic, and discontinuous heterogeneous flow of the transpression zone.

Recently developed tissue-hydrogel methods for specimen expansion now enable researchers to perform super-resolution microscopy with ∼65 nm lateral resolution using ordinary microscopes, standard fluorescent probes, and inexpensive reagents. Here we use the combination of specimen expansion and the optical super-resolution microscopy technique structured illumination microscopy (SIM) to extend the spatial resolution to ∼30 nm. We apply this hybrid method, which we call ExSIM, to study the cytoskeleton of the important human pathogen Giardia lamblia including the adhesive disc and flagellar axonemes. We determined the localization of two recently identified disc-associated proteins, including DAP86676 , which localizes to disc microribbons, and the functionally unknown DAP16263 , which primarily localizes to dorsal microtubules of the disc overlap zone and the paraflagellar rod of ventral axonemes. Based on its strong performance in revealing known and unknown details of the ultrastructure of Giardia, we find that ExSIM is a simple, rapid, and powerful super-resolution method for the study of fixed specimens, and it should be broadly applicable to other biological systems of interest.

Joining of nanostructured metals by conventional processes, such as welding, often destroys the functionality of the material by disrupting its microstructure within the heat-affected zone. We present a lithography-based approach to joining of magnetron sputtered, nano-layered Cu/Nb composites without compromising the integrity of the nano-layered architecture by using a microstructure-preserving lap joint. We characterize the lap joint using scanning electron microscopy and nanoindentation, exploring potential variations in structure and mechanical properties within the parent material, overlap zone, and gap zone. Our work advances future applications of nanocomposite materials by paving the way towards practical, microstructure-preserving methods of joining them.

The finless porpoise (genus Neophocaena) is a poorly known cetacean of great conservation concern. Within its range, from western Pacific to northwestern Indian Ocean, there are currently two species recognized (N. asiaeorientalis and N. phocaenoides), thought to be reproductively isolated since last glacial maximum, with the only sympatric overlap zone in Taiwan Strait. However, the genetic variation across the genus’ distribution has not yet been extensively studied, especially in the Indian Ocean. We performed an exhaustive review of molecular data of the finless porpoise across its range. Neighbor-net networks analyses based on two mitochondrial loci (control region/CR and cytochrome b/cyt b) suggest that finless porpoises from the Indian and Pacific Ocean constitute two distinct clades, well-defined by fixed mutations at both loci. A molecular clock analyses indicate early split (CR: 13.1 Ma, cyt b: 12.9 Ma) between these two oceanic lineages, while spatial genetic analyses further suggest that in the Pacific the divergence was primarily due to the taxon from Japanese waters rather than inter-species divergence across the Taiwan Strait. As extinction risks can be substantially underestimated if threatened species are pooled together with non-threatened, especially in the absence of long-distance migration, we suggest that the present 2-species taxonomy of the genus Neophocaena should be given further examination, with concerted sampling effort in the Western Indian Ocean. More research effort and genomic information is needed before taxonomic revisions can be considered; such further studies are strongly recommended as they may affect the current status classification of the species constituting the genus Neophocaena. Most notably, the narrow-ridged finless porpoise off Japan merits urgent conservation attention.

A three-scale diffusion model for textiles was given in Goessens etźal. (2015): consisting of a fiber, yarn and room model. To analyze and simplify the model, its characteristic times were investigated in Goessens etźal. (2015) 8, 9. At these times the fiber and yarn model, and the yarn and room model, respectively, tend to reach a partial equilibrium concentration. Here an addition will be made to the model based upon the previous work. An overlap zone is considered between the yarn and room level. Then the overlapping domain decomposition technique is used to calculate the exchange of active ingredient from one level to another in this zone. The mass balance for the system with the overlap zone is calculated and tested in C-language.

A simple model of cardiac muscle was designed for multiscale simulation of heart mechanics. Relaxed cardiac muscle was described as a transversally isotropic hyperelastic material. Active tension caused by actin-myosin crossbridges depends on the ensemble averaged strain of myosin heads bound to actin. Calcium activation was modeled by Ca2+ binding to troponin-C. To account for the dependence of troponin affinity for Ca2+ on myosin heads strongly bound to actin, the kinetics of troponin binding to Ca2+ in the overlap zone of the thin and thick filaments and outside it were separated. The changes in the length of these zones during muscle shortening or lengthening were accounted for explicitly. Simplified version of the model contains only 5 ordinary differential equations (ODE). Model parameters were estimated from a limited set of experiments with skeletal and cardiac muscle. Simulations have shown that model reproduces qualitatively a number of experimental observations: steady-state force-velocity and stiffness-velocity relations; mechanical responses to step changes in muscle length or load; steep Ca2+-tension relationship and its dependence on sarcomere length tension (the Frank-Starling mechanism); tension, shortening and Ca2+-transients in twitch isometric and isotonic contractions, tension development and redevelopment upon fast change in Ca2+ concentration or muscle release followed by re-stretch. We believe that the model can be effectively used for modeling contraction and relaxation of the heart.

The paper deals with the interface behavior of a smart patch/layer lightweight structure subjected to combined time harmonic mechanical loading, electric field and environmental conditions. The applied dynamic shear-lag and Fourier method refer to the overlap zone of the considered structure. It gives a possibility to obtain solutions in a closed form for axial and shear stresses of the structure. The types of solutions obtained depend mainly on the adherends’ thickness, the frequency interval of applied dynamic loading and the shear modulus of the used adhesive. At a given constant ratio of thicknesses of the adherends, the frequency interval of the dynamic load can change drastically the type of solution of the considered system of ordinary differential equations. Theoretical predictions for single debond length of patch/layer structure at an elastic-brittle interface behavior are provided. The influence of the ratio of thicknesses of the adherends in PZT-5H/CFRP patch/layer structure and the frequency range of applied dynamic mechanical loading on the interface delamination is investigated. All results are illustrated in figures and tables and are discussed.

This paper presents a quantitative assessment of the aging process in the occupational neurotoxicosis. Acceleration rate of biological aging has been demonstrated in trained workers of a chemical factory exposed to vinylchloride, metallic mercury vapor in patients with newly proven diagnosis - chronic elemental mercury intoxication and chronic elemental mercury intoxication in the long-term period in 1.9; 2.8; 7.2; 7.5 times compared to the rate of a control group. Six-time increase in the proportion of patients with acceleration rate of aging compared to the norm (70 % vs. 12 %) has been found out among fireman-liquidators. To study the interdependence of indicators characterizing the state of cognitive sphere and the rate of biological aging in patients with occupational neurointoxication a correlation analysis of the data of neuropsychological and clinical and physiological studies has been carried out. Raising of biological age and acceleration rate of biological aging in patients with neurointoxications are accompanied by disorders of categoric, conceptual, analytical - synthetical thinking, audio-verbal (short-term) and the visual image memory, spatial and dynamic praxis, objective gnosis, impressive and expressive speech, caused by deficiency of functioning of the frontal, parietal-temporal, parietal-occipital lobes, premotor and parietal regions of the left brain, overlap zone (tertiary temporo-parietal-occipital cortex).

The Broadly Rifted Zone (BRZ) is a ~ 315 km wide zone of extension in southern Ethiopia. It is located between the Southern Main Ethiopian Rift and the Eastern Branch of the East African Rift System (EARS) represented by the Kenya-Turkana Rift. The BRZ is characterized by NE-trending ridges and valleys superimposed on regionally uplifted (~ 2 km average elevation) terrain. Previous studies proposed that the BRZ is an overlap zone resulted from northward propagation of the Kenya-Turkana Rift and southward propagation of the Southern Main Ethiopian Rift. To understand the relationship between the BRZ's extensional style and its crustal and upper mantle structures, this work first estimated the Moho depth using the two-dimensional (2D) radially-averaged power spectral analysis of the World Gravity Map. Verification of these results was accomplished through lithospheric-scale 2D forward gravity models along E-W profiles. This work found that the Moho topography beneath the BRZ depicts a dome-like shape with a minimum depth of ~ 27 km in the center of the dome. This work proposes that the Moho doming, crustal arching underlying the BRZ and associated topographic uplift are the result of asthenospheric mantle upwelling beneath the BRZ. This upwelling changed to a NE-directed lateral mantle flow at shallower depth. This is supported by seismic tomography imaging which shows slow S-wave velocity anomaly at lithospheric depth of 75 km to 150 km stretching in a NE-SW direction from beneath the BRZ to the Afar Depression. This work proposes that the asthenospheric upwelling created gravitationally unstable dynamic topography that triggered extensional gravitational collapse leading to the formation of the BRZ as a wide rift within the narrow rift segments of the EARS.

Errors in the estimates of changes in the area of individual water bodies and their groups have been studied in the central part of Yamal Peninsula based on Landsat satellite imagery. For the first time, the overlap zone of two satellite images along satellite trajectory has been proposed for the choice of the most efficient algorithm for identifying water surfaces and estimating the errors in water body area measurements. Empirical equations have been derived to describe the relationship between the error in estimates of changes in the areas of individual water bodies and their groups and the areas themselves. The seasonal and many-year variations in water body areas have been identified in the zone of intense construction of facilities at the Bovanenkovskoe oil-gas condensate field.

In this study, we present inter-, co- and post-seismic displacements observed in the 2015 Illapel earthquake area by Global Positioning System (GPS) and Synthetic Aperture Radar Interferometry (InSAR). RADARSAT-2, ALOS-2 and Sentinel-1A interferograms capture the co- and post-seismic displacements due to the Illapel earthquake. Based on a layered Earth structure, we modeled both co- and post-seismic faulting behaviors on the subduction interface of central Chile. The best-fit model shows that the coseismic rupture broke a 200 km × 200 km area with a maximum slip of 10 m at a depth of 20 km. Two distinct slip centers, likely controlled by local ramp-flat structure, are revealed. The total coseismic geodetic moment is 2.76 × 10 21 N m , equivalent to a moment magnitude 8.3. The accumulated afterslip in the first two months after the mainshock is observed on both sides of the coseismic rupture zone with both ascending and descending Sentinel-1A interferograms. A limited overlap zone between co- and post-seismic slip models can be observed, suggesting partitioning of the frictional properties within the Illapel earthquake rupture zone. The total afterslip releases ∼ 5.0 × 10 20 N m geodetic moment, which is equivalent to an earthquake of M w 7.7. The 2010 M w 8.8 Maule earthquake that occurred ∼400 km away from the Illapel earthquake epicenter could have exerted certain effects on the seismic cycle of the Illapel earthquake area. The seismic records from 2000 to 2015 imply that the rate of annual seismic moment release in the Illapel earthquake area dropped from 0.4 to 0.2 × 10 19 N m / yr after the Maule earthquake. Based on the forward modeling with the best-fit slip models determined in this study, we reproduce the local surface displacements before, during and after the Illapel earthquake. A rough deformation cycle, 105 ± 29 yr , calculated by using the coseismic displacements and interseismic rate is basically identical with the revisit interval of M8 events in the adjacent areas of the Illapel earthquake, suggesting that elastic rebound theory is applicable for the long-term prediction in this region.

In this study a two-dimensional simplified stress function method describing the interfacial stress transfer in adhesively-bonded monolayered graphene/polymer nanocomposite subjected to static extension load is presented. The application of 2D stress function method, combined with minimization of complementary strain energy functional and developing of governing ODE for 2 or even 4 unknown functions, to obtain 2D stresses in adhesively bonded lap joints or laminates can be seen in Hashin, 1985 and Kumar&Tampi, 2016. The governing forth order ordinary differential equation with constant coefficients for the axial (longitudinal) stress in the first graphene layer of nanocomposite structure is obtained using a variational method. Its analytical solution depends mainly on the geometry of the structure, the properties of used materials and tensile loading. A proper criterion for prediction of the interface debond length along the overlap zone of the structure is applied. The analytical results for a case of monolayered graphene/SU-8/PET structure are illustrated in figures and tables. The influence of the static load and the geometry on the stresses and debond length in the considered structure is analyzed.

The present paper presents multiscale modelling via coupling of the discrete and finite element methods. Theoretical formulation of the discrete element method using spherical or cylindrical particles has been briefly reviewed. Basic equations of the finite element method using the explicit time integration have been given. The micr-macro transition for the discrete element method has been discussed. Theoretical formulations for macroscopic stress and strain tensors have been given. Determination of macroscopic constitutive properties using dimensionless micro-macro relationships has been proposed. The formulation of the multiscale DEM/FEM model employing the DEM and FEM in different subdomains of the same body has been presented. The coupling allows the use of partially overlapping DEM and FEM subdomains. The overlap zone in the two coupling algorithms is introduced in order to provide a smooth transition from one discretization method to the other. Coupling between the DEM and FEM subdomains is provided by additional kinematic constraints imposed by means of either the Lagrange multipliers or penalty function method. The coupled DEM/FEM formulation has been implemented in the authors’ own numerical program. Good performance of the numerical algorithms has been demonstrated in a number of examples.

Various techniques for producing fixed joints in solid using electromagnetic fields are considered; basic diagrams, physics, features, and technical capabilities of each method are described. It is shown that thin-walled tubular irregular structures can be obtained under the magnetic-pulse moulding welding that joins the combined actions of induced currents passing through the overlap zone and magnetic pressure for apposing the weldable edges and for shaping in accordance with the matrix configuration. Obtaining joints from dissimilar materials and structures of different thicknesses is implemented due to shock pulse capacitor welding with magnetic pulse drive. The series connection of the weldable parts enables to synchronize the current flow and force impact on the weld junction. Depending on the combination of the weldable products, three techniques of shock pulse capacitor welding with magnetic pulse drive are proposed. To intensify the quality improvement of the female connectors obtained, it is proposed to use the magnetic-pulse welding in vacuum instead of the diffusion welding. Preheating of the complete unit in vacuum allows for the pre-activation of the connectable surfaces. A unique feature of the implemented diagram is a remote action on the telescopic joints of dissimilar alloys heated in vacuum to the pre-melting temperatures through a quartz glass.

In this work, H13 buildups were produced through wire-arc additive manufacturing based on cold metal transfer technology. Four different deposition strategies were employed for the fabrication and the microstructural evolution and mechanical properties of the corresponding buildups were compared. A bimodal microstructure for all buildups produced in the overlap zone (OZ) and body zone (BZ), respectively, despite a mixture of lath-shaped martensites and blocky δ-ferrites in the OZ and a slightly coarser but still fine martensites in the BZ. The as-deposited mechanical properties were evidently superior to the properties of the base metal after annealing, but slightly inferior to that after quenching and tempering. Compared with the components with different deposition patterns between adjacent layers, the relatively enhanced hardness and wear-resistance properties were acquired for the ones with the same scanning strategies, being responsible for the smaller retained δ-ferrite size in the OZ and slightly refined martensites in the BZ. The deposition strategy had a negligible influence on the wear surface hardness, all decreasing gradually from the wear zone to the transient zone and finally keeping stable as a result of the locally martensitic evolution. As the in-situ thermal history was influenced by the deposition strategies, both of the microstructural distribution and mechanical performances were affected by the deposition strategies. Besides, the applied strategies, characterized by the different scanning directions between adjacent tracks, had a negligible influence on microstructures and mechanical properties following comparison with the counterparts with the different directions between adjacent layers.

The taxonomy of Tursiops truncatus in the western South Atlantic is not resolved. Two different hypotheses have been proposed: (1) offshore and coastal ecotypes with a parapatric distribution, and (2) two species, T. truncatus and T. gephyreus, living in sympatry. To test these hypotheses, we examined a total of 100 physically mature skulls and 35 vertebral columns from the suggested overlap zone in southern Brazil. In all skulls, 24 measurements, four alveoli counts and two categorical variables were analyzed. Vertebral formula was determined and five measurements were taken from selected vertebrae. Multivariate analyses were conducted for skull and vertebral data. Results revealed the presence of two well-separated groups. Specimens of Group1 had smaller skulls and shorter body lengths, but more vertebrae, than Group2. The morphological characteristics of each group corresponded well with two ecotypes of common bottlenose dolphins reported in other ocean basins. Therefore, we assigned the specimens of Group1 to the offshore ecotype, and Group2 to the coastal ecotype. Differences in the geographic locations and ratio of strandings supported the parapatric hypothesis. The significant morphological differentiation observed suggests the presence of different subspecies, but an additional independent line of evidence is needed to hypothesize whether they represent different species.

This study investigated the properties and microstructures of EH46 microalloyed steel following double-sided friction stir welding. The partially welded material was reversed, completing the weld. Yield strength, elongation and toughness of the weld were similar to those of the base material. During welding, the ferrite-pearlite in the base material transformed to mainly upper bainite, but the overlap or interference zone in the centre of the weld consisted predominantly of 0.5–3 µm recrystallised ferrite grains. The microhardness increased from 240 HV in the base material to 350 HV in bainite but decreased 200–240 HV in the overlap zone. These substantially differing microstructures suggest that the overlap or interference zone was processed at a lower temperature than the remainder of the weld, probably in ferrite.