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In this work, the kinetics of the growth of austenite grains upon heating, the features of the processes of dynamic and static recrystallization occurring at various temperature-deformation modes of plastic deformation are investigated. Phase transformations have been studied during continuous cooling of hotdeformed austenite in low-alloy “Arc”-steel with a yield point of at least 420 MPa. The studies carried out made it possible to determine the thermal deformation parameters that ensure the formation of a finely dispersed homogeneous ferrite-bainitic structure, on the basis of which technological recommendations for industrial production were developed and sheet products were manufactured. Presented are the structure and properties of sheet metal from shipbuilding “Arc”-strength category 420 MPa.

International audience; Ozone, PM10 and PM2.5 concentrations over Paris, France and Stockholm, Sweden were modeled at 4 and 1 \unit{km} horizontal resolutions respectively for the present and 2050 periods employing decade-long simulations. We account for large-scale global climate change (RCP-4.5) and fine resolution bottom-up emission projections developed by local experts and quantify their impact on future pollutant concentrations. Moreover, we identify biases related to the implementation of regional scale emission projections over the study areas by comparing modeled pollutant concentrations between the fine and coarse scale simulations. We show that over urban areas with major regional contribution (e.g., the city of Stockholm) the bias due to coarse emission inventory may be significant and lead to policy misclassification. Our results stress the need to better understand the mechanism of bias propagation across the modeling scales in order to design more successful local-scale strategies. We find that the impact of climate change is spatially homogeneous in both regions, implying strong regional influence. The climate benefit for ozone (daily average and maximum) is up to -5 % for Paris and -2 % for Stockholm city. The joined climate benefit on PM2.5 and PM10 in Paris is between -10 and -5 % while for Stockholm we observe mixed trends up to 3 % depending on season and size class. In Stockholm, emission mitigation leads to concentration reductions up to 15 % for daily average and maximum ozone and 20 % for PM and through a sensitivity analysis we show that this response is entirely due to changes in emissions at the regional scale. On the contrary, over the city of Paris (VOC-limited photochemical regime), local mitigation of NOx emissions increases future ozone concentrations due to ozone titration inhibition. This competing trend between the respective roles of emission and climate change, results in an increase in 2050 daily average ozone by 2.5 % in Paris. Climate and not emission change appears to be the most influential factor for maximum ozone concentration over the city of Paris, which may be particularly interesting in a health impact perspective.

In this study, a combined experimental, numerical and theoretical investigation is conducted on the penetration of semi-infinite 4340 steel targets by a homogeneous 93W rod and two types of jacketed rods with striking velocities of 0.9-3.3 km/s. The results show that the jacketed rods produced typical “co-erosion” damage at all test velocities, except for the 93W/1060Al jacketed rod, which switched from an early “bi-erosion” damage to later “co-erosion” damage at a striking velocity of 936 m/s. However, the homogeneous 93W rod always forms a large mushroom head during the penetration process. The damage mechanisms of these two types of jacketed rods differ for striking velocities of 0.9–2.0 km/s, but this difference gradually decreases with increased striking velocity. For velocities of 2.0–3.3 km/s, all three types of projectiles exhibit typical hydrodynamic penetration characteristics, and the damage mechanisms of the two types of jacketed rods are almost identical. For the same initial kinetic energy, the penetration performance of the jacketed rods is distinctly superior to that of the homogeneous 93W rods. Compared with jacket density, jacket strength shows a more significant influence on the damage mechanism and penetration performance of the jacketed rod. Finally, an existing theoretical prediction model of the penetration depth of jacketed rods on semi-infinite targets in the co-erosion mode is modified. It transpires that—in terms of penetration depth—the modified theoretical model is in good agreement with the experimental and numerical observations for 93W/TC4 and 93W/1060Al jacketed rods penetrating semi-infinite 4340 steel targets.

Research on two-dimensional (2D) materials is one of the most active fields in materials science and nanotechnology. Among the members of the 2D family, layered hydroxides (LHs) represent an exceptional case of study due to their unparalleled chemical versatility which allows the modulation of their physicochemical properties at will. Nowadays, LHs based on earth-abundant metals are key materials in the areas of energy storage and conversion, hybrid materials or magnetism. ɑ-Co hydroxides (Simonkolleite-like structures) are promising phases with tuneable electronic and magnetic properties by ligand modification. However, even in the simple case of ɑ-CoII hydroxychlorides, the preparation of well-defined large 2D crystals is not straightforward, hindering the development of fundamental studies. Herein, we present the synthesis of 2D hexagonal crystals with outstanding size-thickness relationship (diameter > 5 μm and thickness of 20 ± 7 nm) by a simple homogeneous synthesis taking place at room temperature. In structural terms, no differences are observed between our layered materials and those obtained hydrothermally. However, dynamic susceptibility measurements alert about different arrangements of the magnetic sublattices, which have been rationalized with structural DFT calculations. This work provides an extremely easy bottom-up method to obtain high-quality 2D crystals based on ɑ-CoII hydroxides, paving the way for the development of fundamental studies and applications. PNICTOCHEM 804110 (G.A.) PID2019-111742-GA-I00 CIDEGENT/2018/001

We present a complete algorithm that computes all hypergeometric solutions of homogeneous linear difference equations and rational solutions of parameterized linear difference equations in the setting of Π Σ ⁎ -fields. More generally, we provide a flexible framework for a big class of difference fields that are built by a tower of Π Σ ⁎ -field extensions over a difference field that enjoys certain algorithmic properties. As a consequence one can compute all solutions in terms of indefinite nested sums and products that arise within the components of a parameterized linear difference equation, and one can find all hypergeometric solutions of a homogeneous linear difference equation that are defined over the arising sums and products.

International audience; Several tsunami record catalogues have been developed for extensive tsunami research. However, completeness analysis of tsunami catalogues, an important step in using these catalogues for tsunami research, has not received sufficient attention. This could result in many biases and incorrect results. In this study, two methods proposed are employed and applied to quantitatively, credibly, and accurately estimate the completeness of a global and regional tsunami catalogue. The results show that: (1) The tsunami runup catalogue for runup-height intervals 0.1 ~ 0.5, 0.5 ~ 1, 1 ~ 5, and 5 ~ 10 m, are complete and homogeneous since the 1950s, which coincides with the extensive development of tide-gauge technol- ogy. The catalogue for 10~20 is complete and homogeneous since the 1930s, which may be related to the end of the global economic crisis that occurred from 1928 to 1933. And the catalogue for 20 m and more is complete and homogenous since the 1890s, the begin- ning of the age of electricity. For runup-height heights from 0.1 to 5 m, the completeness starting time exhibits minimal variation among six regions (Europe region, Indian region, South America, North America, South Pacific, and East Asia), which is related to the rapid economic development period of the world and the establishment of tsunami warning sys- tems. For runup-height intervals, 5~10, 10~20, and 20~, the completeness starting time varies considerably among regions. The completeness starting time in the EU was earlier than that in other regions, which is related to the level of economic and political develop- ment after the Enlightenment of early Europe.

The conversion of light alkanes into bulk chemicals is becoming an important challenge as it effectively avoids the use of prefunctionalized alkylating reagents. The implementation of such processes is, however, hampered by their gaseous nature and low solubility, as well as the low reactivity of the C-H bonds. Efforts have been made to enable both polar and radical processes to activate these inert compounds. In addition, these methodologies also benefit significantly from the development of a suitable reactor technology that intensifies gas-liquid mass transfer. In this review, we critically highlight these developments, both from a conceptual and a practical point of view. The recent expansion of these mechanistically-different methods have enabled the use of various gaseous alkanes for the development of different bond-forming reactions, including C-C, C-B, C-N, C-Si and C-S bonds.

In this paper, motivated by considerations of server utilization and energy consumption in cloud computing, we investigate a homogeneous queueing system with a threshold-based workload control sche...

In the past decade, polymeric magnetic membranes have been used to investigate mechanical stimuli on adherent cells and cellular mechanotransduction. However, the homogeneity of these particles inside these membranes is often overlooked. In this study, magnetic polydimethylsiloxane (PDMS) membranes were prepared by using magnetite (Fe3O4) particles effectively dispersed inside PDMS for the assessment of possible cellular behavior changes. Magnetite particles were synthesized using the co-precipitation method. Magnetic-particle-embedded PDMS (mpPDMS) membranes were prepared by homogenizing magnetic particles with a PDMS elastomer before the curing process. The magnetization, molecular composition and mechanical properties of these mpPDMS membranes were analyzed by using vibrating-sample magnetometry, optical microscopy, Fourier transform infrared spectroscopy and rheometry. The biocompatibility, cell viability and morphology of human fetal osteoblast (hFOB) cells were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, alamarBlue cell proliferation assay and F-actin/4′,6-diamino-2-phenylindole staining. The results indicated that membranes fabricated using the presented methodology had increased magnetic particle homogeneity compared with those in previous studies and hFOB cells maintained their functionality on 0.5% (w/w) mpPDMS membranes. The methodology for the fabrication of mpPDMS reported here could be used in future studies for the investigation of cellular mechanotransduction pathways in a more controlled and repeatable manner on PDMS-based substrates.

This paper looks at how changes of coordinates on a pseudo-Riemannian manifold induce homogeneous linear transformations on its tangent spaces. We see that a pseudo-orthonormal frame in a given tangent space is the basis for a set of Riemann normal coordinates. A Lorentz subgroup of the general linear transformations preserves this pseudo-orthonormality. We borrow techniques from the methodology of non-linear realizations to analyze this group-subgroup structure. `Parallel maps' are used to relate tangent space at different points. `Parallelisms' across a finite region of the manifold may be built up from them. These are used to define Weitzenb\"{o}ck connections and Levi-Civita connections. This provides a new formulation of teleparallel gravity, in which the tetrad field is viewed as a field-valued group element relating the coordinate basis to the frame basis used in defining a parallelism. This formulation separates the metric degrees of freedom from those associated with the choice of parallelism. The group element can be combined by matrix multiplication with Lorentz transformations of frame or with other Jacobian matrices. We show how this facilitates a new understanding of inertial forces and local Lorentz transformations. The analysis is also applied to translations of the coordinates. If they are constant across spacetime, this has no effect on the tangent space bases. If the translation parameters become fields, they induce general linear transformations of the coordinate basis; however, the tetrad components can only be expressed in terms of translations on a flat spacetime., Comment: 36 pages, 1 figure. Electronic version of an article published as International Journal of Geometric Methods in Modern Physics (IJGMMP), Volume No. 18, Issue No. supp01, Article No. 2140008, Year 2021, 36 pages, doi.org/10.1142/S0219887821400089. Copyright World Scientific Publishing Company https://www.worldscientific.com/worldscinet/ijgmmp

We present a construction of C 1 piecewise quadratic hierarchical bases of Lagrange type on arbitrary polygonal domains Ω ⊂ R 2 . Properly normalized, these bases are Riesz bases for Sobolev spaces H s ( Ω ) , with s ∈ ( 1 , 5 2 ) . The method is applicable to arbitrary initial triangulations of polygonal domains, and does not require a checkerboard quadrangulation needed for earlier C 1 cubic hierarchical Lagrange bases. Homogeneous boundary conditions can be taken into account in a natural way, and lead to Riesz bases for Sobolev spaces H 0 s ( Ω ) , s ∈ ( 1 , 5 / 2 ) ∖ { 3 / 2 } , and H 00 3 / 2 ( Ω ) .

The high-temperature mechanical and dielectric properties of Si2N2O ceramics are often limited by the introduction of a sintering aid. Herein, dense Si2N2O was prepared at 1700 °C by hot-pressing oxidized amorphous Si3N4 powder without sintering additives. A homogeneous network with short-range order and a SiN3O structure was formed in the oxidized amorphous Si3N4 powder during the hot-pressing process. Si2N2O crystals preferentially nucleated at positions within the SiN3O structure and grew into rod-like and plate-like grains. Fully dense ceramics with mainly crystalline Si2N2O and some residual amorphous phases were obtained. The as-prepared Si2N2O possessed a good flexural strength of 311 ± 14.9 MPa at 1400 °C, oxidation resistance at 1500 °C, and a low dielectric loss tangent of less than 5 × 10−3 at 1000 °C.

Since the discovery of two-dimensional (2D) transition metal carbides and nitrides, known as MXenes, research on these wonder 2D inorganic compounds has become increasingly intensified with their members quickly expanding. MXenes' state-of-the-art applications are heavily dependent on their processing strategies and manufacturing methods. Nevertheless, the solution processing of MXenes has not been comprehensively reviewed. This review summarizes progress regarding solution processing of MXenes over the past decade as well as outlines key perspectives for future scalable manufacturing strategies. Etching of MAX phases and delamination of MXene are briefly introduced. Rheological properties of MXene dispersions and wetting of the MXene inks, which are crucial for the achievement of high-resolution printing and homogeneous coating, are discussed in detail. We have discussed the ink formulation strategies and fine-tuning of the ink properties to match with that of the targeted substrates to yield efficient yet high-quality printed/coated films/structures. As such, we demonstrate a “map of guidelines” for solution-based processing of MXenes toward high-performance applications, such as electrochemical energy storage, conductive electrodes, electromagnetic interference shielding, and so on.

Some Deep Neural Networks (DNN) have what we call lanes, or they can be reorganized as such. Lanes are paths in the network which are data-independent and typically learn different features or add resilience to the network. Given their data-independence, lanes are amenable for parallel processing. The Multi-lane CapsNet (MLCN) is a proposed reorganization of the Capsule Network which is shown to achieve better accuracy while bringing highly-parallel lanes. However, the efficiency and scalability of MLCN had not been systematically examined. In this work, we study the MLCN network with multiple GPUs finding that it is 2x more efficient than the original CapsNet when using model-parallelism. We introduce the load balancing problem of distributing heterogeneous lanes in homogeneous or heterogeneous accelerators and show that a simple greedy heuristic can be almost 50% faster than a naive random approach. Further, we show that we can generate MLCN models with heterogeneous lanes with a balanced fit for a given set of devices. We describe a Neural Architectural Search generating MLCN models matching the device's memory that are load balanced. This search discovered models with 18.6% better accuracy for CIFAR-10.

Improving both surface and space utilization of active carbon is crucial for compact supercapacitors. Herein, two activated carbons are prepared through homogeneous activation (HAC) and traditional outside-in activation (OIAC). Compared with OIAC with deep and branched porous structure, HAC shows an interconnected porous structure, leading to higher density, better gravimetric and volumetric capacitances, and improved rate performance. The results demonstrate that interconnected porous structure by homogeneous activation promotes high surface and space utilization as well as robust ion transport kinetics of activated carbon for capacitive energy storage.

Micro-perforated panels (MPPs) are one of the most promising alternatives to conventional porous sound-absorbing materials. Traditionally, the theory of the sound absorption properties of MPPs is based on the assumption that MPPs are a homogeneous material with identical pores at regular intervals. However, in recent years, some MPPs have not met these conditions, and although a variety of designs have been created, their properties and prediction methods were studied in only fewer works. In this paper, considering the wide variety of MPP designs, we made a trial production of heterogeneous MPPs, which are MPPs with holes of different diameters, and studied the prediction method applicable to these MPPs. We measured the normal incidence sound absorption characteristics of those MPPs, backed by a rigid backing and air-cavity in-between, in an impedance tube. The prediction method proposed in this work is to treat the heterogeneous MPPs as combinations of several homogeneous components, and to combine them after applying the existing theory on homogeneous MPPs to each component. As a result, except in a few cases, the measured and predicted values of the absorption properties agreed relatively well. We also found that the arrangement of the holes in the material and the depth of the back cavity affected the agreement between the measured and predicted results.

We formulate the generic τ-function of the homogeneous Painlevé II equation as a Fredholm determinant of an integrable (Its–Izergin–Korepin–Slavnov) operator. The τ-function depends on the isomonodromic time t and two Stokes parameters. The vanishing locus of the τ-function, called the Malgrange divisor is then determined by the zeros of the Fredholm determinant.

We report the sonochemically activated solid-state synthesis of BaTiO3 powders. Unlike conventional ball-mill mixing, coarse BaCO3 and fine TiO2 powders were sonochemically mixed in ethanol, requiring only 5 min for full mixing and activation. Significantly accelerated phase conversion to BaTiO3 via a solid-state reaction was achieved by the sonochemical mixing, and the process exhibited almost Arrhenius-type activation behavior depending on the ultrasonic power. The sonochemical activation was attributed to the preferential fragmentation of BaCO3 by the ultrasonic irradiation, which led to the particle size reduction and homogeneous mixing in the sonochemical mixtures. Based on the structural, dielectric, and ferroelectric characterizations, we suggest that the sonochemical mixing can replace the time-consuming ball-mill mixing for the solid-state synthesis of BaTiO3 powders and can also be applied to develop a time-saving, contamination-free, and cost-effective process for various ceramic industries.

As a refractory transition-metal diboride, monolithic TiB2 oxidizes at temperatures below 400 °C. Here, we performed detailed microstructural investigations to study the low-temperature oxidation mechanism of monolithic TiB2. An anomalous rapid oxidation behavior is observed at ∼ 500 °C, where the oxidation rate is much higher than that at a higher temperature of 650 °C. The anomalous rapid oxidation behavior originates from an unreported bi-layer oxide scale consisting of outer homogeneous B2O3/TiO2 mixed layer with a supra-nanometre-sized dual-phase amorphous-crystal microstructure and inner unstable Ti-B-O amorphous layer. By contrast, the oxide scale changes from homogeneous mixed microstructure to a laminated configuration at 650 °C, restoring the superior oxidation resistance. Our experimental results indicate that it is the configuration of the oxide scale that determines primarily the oxidation behavior of TiB2, which has been seldom envisaged in previous studies.

Nanocrystalline metals with high Gibbs free energy have a strong tendency towards thermally driven grain growth, thus understanding the critical size or temperature of grain growth is vital for their applications. The investigations of thermal stability were usually conducted on the materials with a homogeneous structure; however, these methods are time-consuming and expensive. In the present work, we reveal a high-throughput experimental strategy to characterize the size-dependent thermal stability via annealing the gradient structured Ni. Employing this method, the critical size of grain growth (dc) at a given annealing temperature was rapidly determined. The critical size of grain growth was ∼95 nm when annealed at 503 K for 3 h, which is consistent with the value reported in the homogeneous structured Ni. Furthermore, this critical size was found to be identical in three types of gradient structured Ni, i.e., independent on the gradient structure. Our present work demonstrates a high-throughput strategy for exploring the critical size of grain growth and size-dependent thermal stability of metals.

This study aimed to determine the discriminatory power of textural features to differentiate the sorghum grains subjected to normal, mild deficit, and severe deficit irrigation. The studies were carried out with the use of image processing, discrimination analysis, analysis of variance and cluster analysis using the selected texture parameters calculate for images from individual color channels L, a, b, R, G, B, U, V, S, X, Y and Z. The results indicated that different levels of irrigation can discriminate the sorghum grain with an accuracy of up to about 100%. Most of the genotypes for each level of irrigation were different in the terms of values of textural features and formed separate homogeneous groups. Drought is one of the limiting factors contributing to a decrease in sorghum grain productivity and nutritional quality, especially when it is cultivated in a marginal area. Therefore, low-quality grains produced under water stress should be recognized before they enter into the food and feed chain. The application of image analysis based on textures of sorghum grain images proved to be useful for the discrimination of sorghum grains subjected to drought stress. The applied procedure provided the fast, objective results that may be applied in practice for screening distinguishing the sorghum grains with different irrigation levels.

Understanding the historical context of an area enables an incoming conservationist to reflect on their role in communities and to better position themselves both politically and socially within them. Here, we explore how outside agencies and institutions, including a former colonial power, have affected and influenced local communities who share their landscape with Barbary macaques (Macaca sylvanus) in Bouhachem forest, north Morocco. In the context of initiating Barbary macaque conservation activities, we interviewed representatives from local governmental and nongovernmental organizations, city dwellers, and villagers about the historical, political, and social context of the study site. We found that villages around Bouhachem were politically and socially marginalized and discriminated against by the state and urban society. The existence of these divisions and the outside agencies’ simplistic view of villages as homogeneous communities negatively influenced conservation interventions, because people resisted initiatives imposed on them without prior consultation. We found that Bouhachem villagers have been, and still are, excluded from meaningful participation in the conservation of the forest and this finding encouraged us to decolonize our own practice. We engaged meaningfully with members of the surrounding communities and responded to news of erroneous stories about our activities by developing a project working in three villages that included all households. Based on our experiences, we recommend that all conservationists conduct historical and qualitative research to gain a deeper, more nuanced understanding of the communities they work in. This understanding should encourage conservationists to recognize their own social and cultural biases and to decolonize their practice. Attending to our own position may help us to avoid underestimating and alienating people who view conservation actions through a very different but equally valid lens.التخلص من التداعيات الاستعمارية في المحافظة على الرئيسيات :دراسة حالة من شمال المغربخلاصة : إن فهم السياق التاريخي لمنطقة معينة، يمكّن المحافظ البيئي الوافد من التفكير في دوره في المجتمعات، ولانسجامٍ سياسيٍ واجتماعي أفضل داخلها. هنا نكتشف كيف أثرت الوكالات والمؤسسات الخارجية ، بما في ذلك القوة الاستعمارية السابقة، على المجتمعات المحلية التي تتعايش مع قرود المكاك البربري (Macaca sylvanus) في غابة بوهاشم شمال المغرب. في سياق بدء أنشطة الحفاظ على المكاك البربري، أجرينا مقابلات مع ممثلين من المنظمات الحكومية وغير الحكومية المحلية وسكان المدن والقرويين حول السياق التاريخي والسياسي والاجتماعي لموقع الدراسة. وجدنا أن القرى المحيطة بغابة بوهاشم كانت مهمشة و معرضة للتمييز ضدها سياسياً واجتماعياً من قبل الدولة والمجتمع الحضري. و أثر بشكل سلبي وجود هذه الانقسامات والنظرة السطحية للوكالات الخارجية للقرى على أنها مجتمعات متجانسة، على تدخلات الحفظ البيئي، لأن الناس رفضوا أي مبادرة مفروضة عليهم دون استشارة مسبقة. و وجدنا أن القرويين في بوهاشم كانوا ولا يزالون مستبعدين من المشاركة الهادفة في الحفاظ على الغابة، وهذا الاكتشاف شجعنا على التخلص من التداعيات الاستعمارية في ممارستنا. لقد تواصلنا بشكل هادف بأعضاء من المجتمعات المحيطة، واستجبنا لأخبار القصص الخاطئة حول أنشطتنا من خلال تطوير مشروع يعمل في ثلاث قرى شمل جميع الأسر. بناءً على تجاربنا، نوصي جميع دعاة الحفاظ على البيئة بإجراء بحث تاريخي ونوعي لاكتساب فهم أعمق وأكثر دقة للمجتمعات التي يعملون فيها. يجب أن يشجع هذا الفهم دعاة الحفاظ على البيئة على التعرف على التحيزات الاجتماعية والثقافية الخاصة بهم، والتخلص من التداعيات الاستعمارية في ممارساتهم.قد يساعدنا الاهتمام بموقفنا الخاص على تجنب الإبعاد و التقليل من شأن الأشخاص، الذين ينظرون إلى إجراءات الحفاظ على البيئة من منظور مختلف تمامًا لكن عادل .

Few classes of natural products rival the structural audacity of oligosaccharides. Their complexity, however, has stood as an immense roadblock to translational research, as access to homogeneous material from nature is challenging. Thus, while carbohydrates are critical to the myriad functional and structural aspects of the biological sciences, their behavior is largely descriptive. This challenge presents an attractive opportunity for synthetic chemistry, particularly in the area of human milk science. First, there is an inordinate need for synthesizing homogeneous human milk oligosaccharides (HMOs). Superimposed on this goal is the mission of conducting syntheses at scale to enable animal studies. Herein, we present a personalized rumination of our involvement, and that of our colleagues, which has led to the synthesis and characterization of HMOs and mechanistic probes. Along the way, we highlight chemical, chemoenzymatic, and synthetic biology based approaches. We close with a discussion on emergent challenges and opportunities for synthesis, broadly defined, in human milk science.

We introduce a multigrid method that is homogeneous in the sense that it uses the same hybridizable discontinuous Galerkin (HDG) discretization scheme for Poisson’s equation on all levels. In particular, we construct a stable injection operator and prove optimal convergence of the method under the assumption of elliptic regularity. Numerical experiments underline our analytical findings.

The classical results by J. Fell, J. Tomiyama, M. Takesaki describe n-homogeneous С*-algebras as algebras of all continuous sections for an appropriate algebraic bundle. By using this realization, several authors described the set of n-homogeneous С*-algebras with different spaces of primitive ideals. In 1974 F. Krauss and T. Lawson described the set of all n-homogeneous С*-algebras whose space Prim of primitive ideals is homeomorphic to the sphere S2. Suppose the space PrimA of primitive ideals is homeomorphic to the sphere S3 for some n-homogeneous С*-algebra A. In this case, these authors showed that the algebra A is isomorphic to the algebra C(S3,Cn×n). If n ≥ 2 then there are countably many pairwise non-isomorphic n-homogeneous С*-algebras A such that PrimA ≅ S 4. Further, let n ≥ 3. There is only one n-homogeneous С*-algebra A such that PrimA ≅ S 5. There are two non-isomorphic 2-homogeneous С*-algebras A and B with space PrimA ≅ S 5. On the other hand, algebraic bundles over the torus T 2 are described by a residue class [p] in Z/nZ = π1(PUn). Two such bundles with classes [pi] produce isomorphic С*-algebras if and only if [p1] = ±[p2]. An algebraic bundle over the torus T 3 is determined by three residue classes in Z/nZ. Anatolii Antonevich and Nahum Krupnik introduced some structures on the set of algebraic bundles over the sphere S2. Algebraic bundles over the compact connected two-dimensional oriented manifolds were considered by the author. In this case, the set of non-equivalent algebraic bundles over such space is like the set of algebraic bundles over the torus T2. Further advances could be in describing the set of algebraic bundles over the 3-dimensional manifolds.

We prove a generalization of the Fulton–Hansen connectedness theorem, where $${\mathbb {P}}^n$$ P n is replaced by a normal variety on which an algebraic group acts with a dense orbit.

Software packages for computing seismic traveltimes and raypaths in an isotropic, spherically symmetric, Earth model are well known and widely used. However, even though the theory for transversely isotropic (TI), spherically symmetric, models has been known since the late 1960s, readily available programs for traveltime calculations are restricted to isotropic models. We have developed a new software package, ANISOtime, for computing seismic traveltimes and raypaths in laterally homogeneous, TI, spherical media. This package calculates traveltime tables for both immediate and subsequent use. ANISOtime has both graphical user interface and command-line interface modes. The package is available for free public download. As it offers cross-platform compatibility through Java 8, it runs on Windows, macOS, Unix, and Linux.

In this paper, a numerical study is presented to investigate wave force on the connections of main parts of a side-anchored straight floating bridge concept for the Bjørnafjorden fjord crossing. The floating bridge is supported by 18 pontoons, and three groups of mooring lines are employed to restrain the bridge against horizontal loads and increase its transverse stiffness. The created wave forces at the connections of pontoon-column and column-girder of the floating bridge considering the effects of short-crested and long-crested waves, varying wave direction, hydrodynamic interaction between pontoons, and mooring system are analyzed. It is found that short-crested and long-crested waves depending on their direction decrease or increase the wave forces on the joints. Considering that the effect of hydrodynamic interaction between pontoons can increase or reduce the wave forces and moments created in the joints, which means the neglect of the hydrodynamic interaction effects between the pontoons to simplify the modeling of this type of floating bridge, may be unacceptable. Moreover, the results showed that the bridge mooring system does not merely reduce the wave forces and moments at joints along the bridge.

A model of the magnitude of the stresses of the tip of the cutting blades of a thread-forming tool based on the theory of a homogeneous body is proposed. A model of second-order materials is considered. A description of the stress state is given using two stress tensors independent of each other.

Pursuit-evasion is the problem of capturing mobile targets with one or more pursuers. We use deep reinforcement learning for pursuing an omni-directional target with multiple, homogeneous agents that are subject to unicycle kinematic constraints. We use shared experience to train a policy for a given number of pursuers that is executed independently by each agent at run-time. The training benefits from curriculum learning, a sweeping-angle ordering to locally represent neighboring agents and encouraging good formations with reward structure that combines individual and group rewards. Simulated experiments with a reactive evader and up to eight pursuers show that our learning-based approach, with non-holonomic agents, performs on par with classical algorithms with omni-directional agents, and outperforms their non-holonomic adaptations. The learned policy is successfully transferred to the real world in a proof-of-concept demonstration with three motion-constrained pursuer drones., Published in RA-L and ICRA

In this paper, our aim is to build generalized homogeneous q-difference equations for q-polynomials. We also consider their applications to generating functions and fractional q-integrals by using the perspective of q-difference equations. In addition, we also reveal relevant relations of various special cases of our main results involving some known results.

Glucagon is a 29-amino acid peptide released from α-cells within pancreatic islets of Langerhans to help raise blood glucose levels. While a plethora of methodologies have been developed for quantitative measurement of insulin released from islets, such methods are not well developed for glucagon despite its importance in blood sugar regulation. In this work, a simple yet robust microfluidic device was developed for holding human pancreatic islets and perfuse them with glucose. The perfusate was collected into 2 min fractions and glucagon quantified using a homogeneous time-resolved Förster resonance energy transfer (TR-FRET) sandwich immunoassay. Simulation of fluid flow within the microfluidic device indicated the device produced low amounts of shear stress on islets, and characterization of the flow with standard glucagon solutions revealed response times within 2 fractions (, A microfluidic device was designed to hold human pancreatic islets of Langerhans for monitoring glucagon secretion using a homogeneous immunoassay.

The Mongolians are mainly distributed in the modern state of Mongolia, China, Russia, and other countries. While the historic and archaeological records of the rise and fall of the Mongol Empire are well documented, little has been known about the genetic legacy of modern Mongolian populations. Here, 611 Mongolian individuals from Hohhot, Hulunbuir, and Ordos of China were genotyped via the 47 Insertion/Deletion markers. Forensically statistical parameters indicated that this InDel system could be applied to forensic investigation in Mongolian populations. The comprehensive population comparisons indicated that targeted Mongolian populations are a homogeneous population, which kept close genetic proximity with geographically northern East Asians. The findings of the model-based clustering analysis revealed a southern East Asian-specific ancestral component, which was maximized in Hainan Li, and Mongolian populations harbored relatively less Hainan Li-related ancestry and more northern East Asian-related ancestry compared with reference Tai-Kadai, Austroasiatic and Sinitic people.

The flexibility of molecular catalysts is highly coveted for the electrochemical reduction of carbon dioxide (CO2) to carbon monoxide (CO) in both homogeneous and heterogeneous systems. While the electrocatalytic activity of molecular catalysts has been widely studied in H-cells; their less studied capabilities in more efficient flow cell reactors have the potential to rival that of heterogeneous catalysts. In this work, a comparative study of amino functionalized iron-tetraphenylporphyrins (amino-Fe-TPPs) immobilized onto carbonaceous materials in both H-cells and flow cells was conducted to selectively reduce CO2 to CO. In a flow cell set up operating in alkaline media, the resulting hybrid catalyst exhibits 87% faradaic efficiency (FE) with extraordinary current density (j) of 119 mA/cm2 and turnover frequency (TOF) of 14 s−1 at −1.0 V vs. RHE. This remarkable catalytic activity was achieved through thoughtful combination of molecular and flow cell design that provides an effective strategy for future immobilized heterogeneous approaches toward CO2 reduction reactions (CO2RRs).

Proton Exchange Membrane Electrolysis of Water (PEMWE) stands out as a scalable, CO2-free process to produce H2 for energy delivery and industrial applications. Due to the limited Ir and Ru worldwide availability, one of the main challenges for the GW-scale PEMWE implementation is the loading reduction of these metals in the anodic catalytic layer. Here, Ir–Ru loading (5 wt%Ir-40 wt%Ru) was deposited through their impregnation over TiO2, followed by a thermal-oxidative treatment, obtaining IrRuOx/TiO2 catalyst. SEM-EDS and HR-TEM confirmed the homogeneous dispersion of IrRuOx on TiO2. The supported catalyst showed a 1.4-fold higher mass activity (85 mA/mg Ir–Ru) for the oxygen evolution reaction (OER) than a mechanical mixture of IrO2–RuO2 1:3 (54 mA/mgIr+Ru) in H2SO4 0.5 M, at 1.52 V/RHE. Furthermore, the supported catalyst retains 90% of its catalytic activity after 100 reaction cycles suggesting the RuO2 intermediate species stabilization by IrOx, which can avoid its irreversibly transform into hydrous RuOx.

In this article, we introduce and study the intersection graph of graded ideals of a graded ring. The intersection graph of $ G- $graded ideals of a graded ring $ R $, denoted by $ Gr_G(R) $, is undirected simple graph defined on the set of nontrivial graded left ideals of $ R $, such that two left ideals are adjacent if their intersection is not trivial. We study properties for these graphs such as connectivity, regularity, completeness, domination numbers, and girth. We also present several results on the intersection graphs related to faithful grading, strong grading, and graded idealization.

Aim: A pH-induced homogeneous liquid–liquid microextraction (HLLME) using a new switchable deep eutectic solvent has been used for the extraction of three antiepileptic drugs from breast milk samples. Methodology: This method is based on phase separation by changing pH. An ammonia solution and a phosphocholine chloride: hexanoic acid: p-aminophenol deep eutectic solvents were used as the phase separation agent and extraction solvent, respectively. Results: Significant factors were studied and the detection limits and enrichment factors were in the ranges of 0.009–0.19 ng ml-1 and 182–212 for the analytes, respectively. Also, linear ranges were wide (0.63–500 ng ml-1) and the method precision was acceptable. Conclusion: The introduced method was successfully applied for the determination of the analyte concentrations in breast milk samples.

We prove existence of solutions and study the nonlocal-to-local asymptotics for nonlocal, convective, Cahn-Hilliard equations in the case of a W 1 , 1 convolution kernel and under homogeneous Neumann conditions. Any type of potential, possibly also of double-obstacle or logarithmic type, is included. Additionally, we highlight variants and extensions to the setting of periodic boundary conditions and viscosity contributions, as well as connections with the general theory of evolutionary convergence of gradient flows.

Five closely spaced Au or Ag NPs are linearly arranged in analogy with Newton's cradle, forming various homogeneous and heterogeneous NP chains. Using small NPs, the Au–Ag–Ag–Ag–Au heterochain has the lowest propagation loss (17.6%) at short resonance wavelengths. When the NP diameter is increased to 80 nm, the dominant resonance is shifted to longer wavelengths. As low as 6% of the total energy dissipates in the intermediate NP component, and there seems to be little difference between the Au–Ag–Ag–Ag–Au heterochain and the Ag–Ag–Ag–Ag–Ag homochain. Besides the wavelength-dependent intrinsic loss (i.e., the imaginary part of the permittivity) in metals, the real part of the permittivity also plays a critical role in determining the propagation loss. Considering the high fabrication cost of the heterochain, the homochain composed of moderately large Ag NPs (

We rework the Mori-Mukai classification of Fano 3-folds, by describing each of the 105 families via biregular models as zero loci of general global sections of homogeneous vector bundles over products of Grassmannians., Comment: Minor changes. To appear in Rev. Mat. Complut

The picking of one or more objects from an unsorted pile continues to be non-trivial for robotic systems. This is especially so when the pile consists of a granular material (GM) containing individual items that tangle with one another, causing more to be picked out than desired. One of the key features of such tangle-prone GMs is the presence of protrusions extending out from the main body of items in the pile. This work characterises the role the latter play in causing mechanical entanglement and their impact on picking consistency. It reports experiments in which picking GMs with different protrusion lengths (PLs) results in up to 76% increase in picked mass variance, suggesting PL to be an informative feature in the design of picking strategies. Moreover, to counter this effect, it proposes a new spread-and-pick (SnP) approach that significantly reduces tangling, making picking more consistent. Compared to prior approaches that seek to pick from a tangle-free point in the pile, the proposed method results in a decrease in picking error (PE) of up to 51%, and shows good generalisation to previously unseen GMs.

espanolLos estudios de la visibilidad de monumentos preteritos cuentan con larga tradicion en el campo arqueologico, siendo una de las aplicaciones de los metodos SIG mas importantes en la actualidad. Este trabajo analiza la visibilidad como factor locacional en las concentraciones megaliticas gallegas de Monte Penide y Serra do Galineiro, utilizando los Sistemas de Informacion Geografica y la estadistica espacial. La investigacion tiene por objetivo analizar si fue la visibilidad hacia los monumentos, desde ellos, o una explicacion conjunta, el elemento que determino el valor espacial de dichas estructuras megaliticas. Para ello, se analiza el territorio geografico en el que se situan los megalitos –visualscapes– y las lineas de horizonte; se realiza un estudio del tamano de sus cuencas visuales y otro combinado entre las rutas de transito natural y la visibilidad de los tumulos. Los resultados apuntan a una complejidad locacional de dicha variable que, con elevada probabilidad, fue crucial a la hora de escoger el emplazamiento de los tumulos megaliticos. Se defiende la idea de que una presencia visual homogenea del tumulo megalitico pudo haber sido uno de los elementos que marcaron la conformacion de estructuras espaciales en las comunidades neoliticas, es decir, sus territorios. EnglishThe analysis of the visual role of ancient monuments has a long tradition in the archaeological field, being one of the most important applications of GIS methods today. This paper analyses the visibility as a locational factor in the megaliths of Monte Penide and Serra do Galineiro, using Geographic Information Systems and spatial statistics. The research aims to analyse if it was the view from the mounds, the view to them, or a joint explanation among both factors, the element which determined the spatial value of the megalithic structures. To this end, the geographic territory in which the megaliths are located –visualscapes– and the horizon lining of the landscape is analysed; a study of the size of the visual basins of the megaliths and the visibility from the natural transit routes is also carried out. The results point out the complexity of this locational variable which, with high probability, was crucial in the choice of the location of the megalithic barrows. We argue that a homogeneous visual presence of the megalithic mound may have been one of the elements that marked the conformation of spatial structures in Neolithic communities, i.e. their territories.

Miniaturization of liquid-liquid extraction is a growing field of sample preparation to reduce solvent consumption, protect the environment, and preserve operators' health. In this work, four different modes of liquid-liquid microextraction have been compared including dispersive liquid-liquid microextraction, binary and ternary salting-out, and sugaring-out induced liquid-liquid microextraction. The extraction efficiency was evaluated by the enrichment factors of 14 different drugs from three pharmacological classes. Compared with the other modes, sugaring-out induced liquid-liquid microextraction was found to be the most efficient and, thus, it was applied for sample preparation of the antivirals in human plasma. Method optimization was performed using response surface methodology for the sugar type and amount (in mg), the sample pH, the equilibration time (in min), and the extractant volume (in µL). The method was then validated and found linear in the concentration range of 0.10-10 µg/mL for daclatasvir, 0.05-10 µg/mL for velpatasvir, and 0.20-10 µg/mL for ledipasvir, with correlation coefficients in the range 0.996-0.999. These results shows that sugaring-out induced liquid-liquid microextraction could be a more efficient microextraction mode for preparation of biological samples. Compared with other types of microextraction, sugaring-out induced liquid-liquid microextraction is greener, simpler, and cost-effective, with less tendency to affect the sample pH.

In skin-pass rolling, which is the last stage of cold rolling, the roughness is transferred to the surface of sheet materials by means of specially roughened rolls. Sheet material becomes ready for use at the end of the skin-pass rolling process. In terms of dyeing and shaping capability of the material, the surface is desired to have an optimum roughness profile. In this study, HC420LA grade sheet material was used from HSLA (high strength low alloy) steels, which has been recently used in the automobile industry to reduce the weight of vehicles and fuel consumption due to its high strength feature. From the rolling parameters, the effects of reduction ratio, rolling speed, roll roughness, and lubricating condition on roughness transfer were investigated experimentally. It was observed that roughness transfer ratio increases as the reduction ratio increases. Roughness transfer ratio decreased as the roll roughness increased and when lubricant was used. In addition, there was no observed effect of the increase in the rolling speed on the roughness transfer ratio. With the use of lubricant, a more homogeneous roughness distribution was obtained compared to the dry conditions. It was concluded that increasing the reduction ratio, roll roughness, and rolling speed disrupted the homogeneous roughness distribution.

Due to the widespread use of copper wires in electrical power transmission, the need for raw materials with a homogeneous structure and high strength while maintaining their conductive properties is of high importance. The present study investigates the production of copper wire with improved mechanical properties and homogeneous microstructure due to its nanometre-sized structure. Therefore, the commercial pure copper specimens were subjected to severe plastic deformation (SPD) by means of equal channel angular pressing (ECAP) during four steps at ambient temperature. Due to the creation of a structure with elongated grains in the ECAP process, the deformed specimens were subjected to the direct extrusion operations; thus, a more homogeneous structure was created in them due to the appearance of a secondary radial strain. The obtained results indicate that by applying the simultaneous effects of SPD and direct extrusion on the microstructure, the mechanical properties such as strength and hardness have improved significantly, while the electrical conductivity of pure copper decreased slightly. The outcome can be used as an alternative to current methods for producing high-strength copper wires with suitable electrical conductivity properties.

Under mild conditions (room temperature, 80 psi of H(2)) Cp*Rh(2-(2-pyridyl)phenyl)H catalyzes the selective hydrogenation of the C═C bond in α,β-unsaturated carbonyl compounds, including natural product precursors with bulky substituents in the β position and substrates possessing an array of additional functional groups. It also catalyzes the hydrogenation of many isolated double bonds. Mechanistic studies reveal that no radical intermediates are involved, and the catalyst appears to be homogeneous, thereby affording important complementarity to existing protocols for similar hydrogenation processes.

The performance of operational extended range forecast (ERF) issued by IMD is evaluated for the southwest monsoon 2019, which is one of the excess monsoon years. The delayed onset of monsoon over southern tip of India, sluggish progress northward and delayed withdrawal of monsoon from Northwest India are very well captured in the ERF with two to three weeks lead time. The revival of monsoon towards the end of June & first week of July, weak phase during 2nd/3rd weeks of July, transition into active phase of monsoon during last week of July & first half of August and very active monsoon conditions in September are also very well captured in the ERF. Quantitatively, over the country as a whole and over the four homogeneous regions of India the ERF provided useful guidance with the country as a whole, the central India and the monsoon zone of India indicating more promising results with the correlation coefficient (CC) between observed and forecast rainfall is significant up to three weeks. Over the Northwest India and South Peninsula, it shows useful skill up to two weeks. Northeast India shows significant skill up to one week only followed by weaker CC in week 2 and again increases in week 3. During the 2019 monsoon season the transition of monsoon from above normal to below normal in July month is well captured in the ERF in smaller spatial scales of meteorological subdivision level forecasts, which is being used widely for agrometeorological advisory purposes up to two weeks.

We report a general strategy to develop injectable welded nanofibers to facilitate the outgrowth and extension of neurites. In this case, nonwoven mats of uniaxially aligned poly(caprolactone)(PCL) nanofibers were firstly cut into several small pieces with fixed fiber lengths of 25, 50 and 100 µm, respectively, using a cryotome. A tissuelyser was employed to homogenize and disperse the short nanofibers to a homogeneous suspension. By tuning treatment duration from 100 s to 400 s, the temperature of the suspension was brought close to the melting point of PCL. As such, the short nanofibers were welded at their cross points while the fibers far away from the cross points remain the original structures. We showed that the viability of neuroblastoma SH-SY5Y cells and their neurite outgrowth and extension were enhanced with the use of such welded short nanofibers. Taken together, this study provides a simple way to generate injectable welded nanofibers, holding potential in affecting neurite outgrowth and extension for nerve repair, in particular, in the central nervous system.

Creep deformation can be classified as homogeneous flow and inhomogeneous flow in bulk metallic glass (BMG). In order to understand the conversion conditions of the two types of creep deformation, the effect of loading rate on the creep behavior of a Ti40Zr10Cu47Sn3 (at.%) BMG at ambient temperature was investigated using nanoindentation and molecular dynamic simulation. Results indicate that at low loading rates, many serrations appear in loading stage, leading to inhomogeneous serrated flow in the creep stage. When the loading rate is high enough, the creep deformation tends to be homogeneous. The related mechanism responsible for the rate-dependent creep behavior is attributed to the number of pre-existing major shear bands which is influenced significantly by the loading rate.

In this paper, the process of a drop rebounding from a hydrophobic and chemically heterogeneous surface is investigated using the multiphase lattice Boltzmann method. The bounce behavior of drops is dependent on the degree of hydrophobicity and heterogeneity of the surface. When the surface is homogeneous, the drop rebounds vertically and the height increases with the enhancement of the surface hydrophobicity. For the heterogeneous surface with two different hydrophobic parts, the drop rebounds laterally toward the lower hydrophobic side. Because the high hydrophobic side exerts the stronger unbalanced Young's force on the contact line compared with the low hydrophobic side, the difference of the forces results in the asymmetrical rebound. A phase diagram displays the rebound numbers of a drop impacting on the various chemically homogeneous and heterogeneous surfaces. A simply quantitative estimation is made to predict the rebound heights and flying times through the contact angles of the surface. This work promotes the understanding of the rebound mechanism of a drop impacting on a chemically heterogeneous surface and provides a guiding strategy for the precise control of the lateral behavior of rebounding drops by hydrophobic and heterogeneous surfaces.