Typical Texture Research Articles

Impact of interfacial texture on failure behaviour of 8YSZ thermal barrier coatings under thermal cyclic loading

Thermal barrier coatings (TBCs) provide thermal protection for high-temperature components of aero-engines and steam turbines, but are susceptible to failure under thermal cyclic loads. The effective design of interfacial texture is one of the approaches to enhance the lifetime of ceramic TBCs. In this study, four types of interfacial textures were designed on the surface of substrates, and 8YSZ coatings of equal thickness were prepared using atmospheric plasma spraying, and thermal cycling tests were carried out. Meanwhile, the thermal cycle lifetime, microstructure evolution, residual stress, and energy release rate criterion were also studied. The optimal morphology and parameters of the texture are determined. It is found that the lifetime of the concave trapezoidal texture is the longest, with a deflection angle of 67°, diameter of 700 μm, depth of 500 μm, and spacing of 5 mm. This study can provide theoretical guidance for the interfacial texture design of ceramic TBCs.

Performance evaluation and comparison of different types of full and partial texture of hydrostatic bearings

To reveal the influence of the different types of surface microtexture on the performance of hydrostatic bearing, microtexture (square, cylindrical, and composite texture) on the inner surface of the bearing were designed. The finite element model of bearing with textures was established. Under the condition of considering the cavitation effect, the influence of the different types of microtexture on performance of the bearing is studied based on the N-S equation. The SEA9 spindle rotation error analyzer is used to determine the eccentricity of the spindle in the machining process and to verify the accuracy of the theoretical simulation. The results demonstrates that the microtexture enhances the performance of hydrostatic bearing, when the eccentricity is in the range of 0∼0.3, compared with square, cylindrica, and smooth bearing, the performance of composite texture bearing can effectively improve the load capacity and reduce the friction coefficient. When the eccentricity is larger than 0.3, the partial textured bearing is analyzed. The initial angle is 120°, the load capacity of the partial microtextured bearing are greater than full microtextured bearing and smooth bearing, which can be used to improve the performance of the bearing. The optimal combination of structural parameters for the performance of the partial composite texture is provided, which has important theoretical significance and practical value for expanding the application range of the spindle system.

Igneous intrusion contact metamorphic system and its reservoir characteristics: A case study of Paleogene Shahejie Formation in Nanpu sag of Bohai Bay Basin, China

Taking the Paleogene Shahejie Formation in Nanpu sag of Bohai Bay Basin as an example, this study comprehensively utilizes seismic, mud logging, well logging, physical property analysis and core thin section data to investigate the metamorphic reservoir formed by contact metamorphism after igneous rock intrusion. (1) A geological model of the igneous intrusion contact metamorphic system is proposed, which can be divided into five structural layers vertically: the intrusion, upper metamorphic aureole, lower metamorphic aureole, normal sedimentary layers on the roof and floor. (2) The intrusion is characterized by xenoliths indicating intrusive facies at the top, regular changes in rock texture and mineral crystallization from the center to the edge on a microscopic scale, and low-angle oblique penetrations of the intrusion through sedimentary strata on a macroscopic scale. The metamorphic aureole has characteristics such as sedimentary rocks as the host rock, typical palimpsest textures developed, various low-temperature thermal metamorphic minerals developed, and medium-low grade thermal metamorphic rocks as the lithology. (3) The reservoir in contact metamorphic aureole has two types of reservoir spaces: matrix pores and fractures. The matrix pores are secondary “intergranular pores” distributed around metamorphic minerals after thermal metamorphic transformation in metasandstones. The fractures are mainly structural fractures and intrusive compressive fractures in metamudstones. The reservoirs generally have three spatial distribution characteristics: layered, porphyritic and hydrocarbon impregnation along fracture. (4) The distribution of reservoirs in the metamorphic aureole is mainly controlled by the intensity of thermal baking. Furthermore, the distribution of favorable reservoirs is controlled by the coupling of favorable lithofacies and thermal contact metamorphism, intrusive compression and hydrothermal dissolution. The proposal and application of the geological model of the intrusion contact metamorphic system are expected to promote the discovery of exploration targets of contact metamorphic rock in Nanpu sag, and provide a reference for the study and exploration of deep contact metamorphic rock reservoirs in the Bohai Bay Basin.

Hot deformation behavior and extrusion temperature-dependent microstructure, texture and mechanical properties of Mg–1Mn alloy

Mg–1Mn alloy, extruded at a low temperature in our published protocol, contributed to the intensified basal texture and extremely refined microstructure with spheroidal nanoscale precipitates dispersing throughout the matrix and along the grain boundaries, consequently resulting in the excellent mechanical properties where the alloy exhibited a tensile yield strength of 204.3 MPa and a ductility of 38.8% at room temperature. Therefore, Mg–1Mn alloy was recommended as one of the potential materials for structural applications. In the present investigation, hot deformation behavior through constitutive analysis and extrusion temperature-dependent microstructure, texture and mechanical properties of as-extruded Mg–1Mn alloy were investigated, aiming at revealing how extrusion temperature affected microstructure, texture, and mechanical properties of as-extruded Mg–1Mn alloy. X-ray diffraction patterns demonstrated that phase components of the experimental alloys consisted of the α-Mg matrix and Mn precipitates. Optical microscopy images indicated a significant increase in average grain size of the alloys as the extrusion temperature increasing from 250 °C to 400 °C. Scanning electron microscopy graphics revealed that coarsened particles identified as Mn precipitates by EDS were observed within the matrix when extrusion temperature reached 400 °C. Inverse pole figure maps of the experimental samples subjected to different extrusion temperatures in the present work exhibited the typical basal texture, suggesting that basal slip was activated hardly during the tensile stress applied along the extrusion direction. Consequently, extrusion temperature displayed the significant impact on microstructure, texture, and mechanical properties of as-extruded Mg–1Mn alloy. The alloy extruded at both 250 °C and 300 °C exhibited the strong basal texture and refined microstructure with spheroidal nanoscale precipitates dispersing within the matrix and along the grain boundaries, which contributed to their excellent comprehensive mechanical properties. The alloy extruded at 400 °C possessed the typical basal texture and coarsened microstructure, leading to the extremely poor mechanical properties. Simultaneously, the constitutive model of the Arrhenius equation based on Zener-Hollomon parameters was also established in the present investigation. Therefore, optimizing the extrusion temperature to regulate the microstructure, grain orientation distribution, and morphology of precipitates was considered as one of the effective approaches for achieving the excellent mechanical properties of Mg alloys.

Drainage Practice of Rice Paddies as a Sustainable Agronomic Management for Mitigating the Emission of Two Carbon-Based Greenhouse Gases (CO2 and CH4): Field Pilot Study in South Korea

Rice is one of the staple foods in Asian countries, and rice paddies are significant sources of greenhouse gas (GHG) emissions in agricultural sectors. In addition, drainage practice has been recognized as a key factor influencing both rice production and GHG emissions. In this field pot study, the effect of drainage method (e.g., intermittent drainage (ID) and continuous flooding (CF)) on GHG (CO2 and CH4) emissions was determined from three Korean paddies (BG, MG, and JS series), varying soil properties such as soil texture, labile carbon, and mineral types. The emission of GHGs was evidently influenced by the drainage, depending on the paddy’s redox (Eh) shift upon flooding events. The Eh decline upon flooding was slower in JS pot, where pore-water concentration of ferric and sulfate ions is the highest (~up to 3-fold) among three paddies. MG pot was 2- to 3-fold more percolative than the others and the Eh drop during the flooding period was the smallest (staying above −50 mV). In ID treatment, CH4 emission (t CO2-eq ha−1 y−1) was reduced in a wide range by 5.6 for JS pot, 2.08 for BG pot, and 0.29 for MG pot relative to CF, whereas CO2 emissions (t CO2-eq ha−1 y−1) were increased by 1.25 for JS pot, 1.07 for BG pot, and 0.48 for MG pot due to the enhanced oxidation of labile carbon. Grain yield and aboveground biomass production from ID were no less than those from CF (p < 0.05). Consequently, the increase in global warming potential (Σ GWP) by ID varied as the order of JS (37%) > BG (14%) > MG (~0%) pots, and the negligible effect observed for MG pot is due to the equivalent trade-off between CO2 and CH4. The different benefits of drainage practices among paddy pots is due to the redox response of paddy systems. The findings will be helpful to promote the efficacy of drainage practice on mitigating GHG emissions for the sustainable agronomic management of rice paddies in response to climate change.

Effect of texture on the room temperature tensile and creep properties of Ti–6Al–4V plate with large thickness

Texture is inevitably generated during the rolling process of titanium alloys, which has a significant impact on mechanical properties. The relationship between microstructure, texture and mechanical properties of the rolled Ti–6Al–4V alloy plate with large thickness was systematically investigated in this study. The texture type varied with the thickness of the plate. The basal pole concentrated in the transverse direction (TD) at the surface of the plate and tilted from TD towards the rolling direction (RD) at the quarter thickness of the plate. For the center of the plate, the basal pole had peaks concentrated close to both TD and RD. Tensile tests indicated that TD samples not only have high strength but also maintain good plasticity compared with RD and the normal direction (ND) samples. The yield anisotropy could be explained by the difficulty of prismatic and basal dislocation slip. The cold creep behavior of the thick plate depended on both Schmid factor of dislocation slip and grain size. Moreover, the strain hardening exponent was positively correlated with cold creep strain. Abundant prismatic <a> and pyramidal <c+a> dislocations were activated, and slip transfer and cross-slip made the dislocation slip distance longer, which contributed to creep strain and thus reduced the creep resistance of ND sample.

Strain-induced martensite formation in cryorolled AISI 317 L stainless steel

AISI 317 L stainless steel replaces 316 L grade in some applications due to its superior mechanical strength and corrosion resistance. Aiming at expanding its applicability to structural applications, ongoing studies are dedicated to overcoming the trade-off between strength and ductility. The stacking fault energy decreases with deformation temperature and favors stacking faulting, (nano)twinning and strain-induced martensite (SIM) formation, resulting in severe microstructural fragmentation. The effect of temperature on deformation behavior of AISI 317 L steel was investigated in samples rolled at room temperature to thickness reductions of 50% and 85% and at 77 K to reductions in thickness of 10% and 50%. The microstructural evolution was followed by scanning electron microscopy, Vickers microhardness, X-ray diffraction, magnetization, electron backscatter diffraction (EBSD) and electron channeling contrast imaging (ECCI). The nucleation sites in the early stages of the transformation sequence γ → ε → α’ were identified in the 10% cryorolled sample. The highest volume fraction of α’-martensite reached 45.8% in the cryorolled steel to 50% rolling reduction. Much lower fractions were obtained for samples rolled to 10% reduction at 77 K (2%) and at room temperature to 50% (0.3%) and 85% reductions (1.6%). The texture components after cryorolling were Goss and Brass for austenite; rotated cube, α- and γ-fibers for δ-ferrite and α’-martensite. The ε-martensite presents the typical texture of hcp metals with a c/a ratio above the ideal value and 〈0001〉 − oriented tilted about 21° from the normal direction towards the rolling direction. The results show cryorolling as an effective method for enhancing SIM formation and promoting severe microstructural refinement in AISI 317 L stainless steel.

Estimating soil N2O emissions induced by organic and inorganic fertilizer inputs using a Tier-2, regression-based meta-analytic approach for U.S. agricultural lands

Consistent methods are essential for generating country and region-specific estimates of greenhouse gas (GHG) emissions used for reporting and policymaking. The estimates of direct N2O emissions from U.S. agricultural soils have primarily relied on the use of emission factors (EFs, Tier-1) and process-based models (Tier-3). However, Tier-1 estimates are relatively crude while Tier-3 calculations can be costly. This work addressed this gap by developing a Tier-2, regression-based approach by leveraging a meta-database containing 1883 field N2O observations together with environmental and management covariates from 139 studies. Our results estimated higher monthly soil N2O emissions (N2Om, kg N/ha) during the growing season (0.38) than the fallow period (0.15), highlighting the importance of considering measurement periods when utilizing meta-databases for analyzing N2O drivers. Significantly different N2Om were found for tillage practices (conventional > no-till: 0.42 > 0.27), fertilizer type (liquid > solid manure: 0.55 > 0.32), and soil texture (fine > coarse: 0.36 > 0.22). The comparisons of the influence of crop type and rotation, water management, and soil order on N2O emissions are complicated by regional data availability and interactions among different factors. Additionally, the finding that N2O emissions reported based on area (N2Om), N input rate (EF), or yield can alter treatment rankings underscores the need to establish transparent criteria for rewarding or discouraging regionally-based management practices using N2O metrics. Finally, we show how General Linear Models (GLMs) can be used to estimate country and regional Tier-2 N2Om using a suite of covariates. Our GLMs identified tillage, water management, N input type and rate, soil properties, and elevation as the most influential covariates for the conterminous U.S. The limited accuracy of regional-scale GLMs, however, suggests the need to further improve the quality and availability of GHG and covariate data through concerted efforts in data collection.

Microstructural comparison of hot isostatically pressed Mo[sbnd]10Nb alloys before and after hot rolling

In this work, hot isostatic pressing (HIP) and HIP followed by hot rolling (HIP+HR) were employed to process high-performance Mo10Nb alloys, respectively. The relative density, O content, oxide types, grain size and shape, and texture type of HIP-processed Mo10Nb alloys before and after HR were systematically investigated. The results indicate that the relative densities of Mo10Nb alloys prepared by the two methods are both over 98%. The oxygen content of HIP-processed and (HIP+HR)-processed Mo10Nb alloys is 638 ± 38 ppm and 2297 ± 152 ppm, respectively. X-ray photoelectron spectrometry (XPS) confirms that the main oxides in HIP-processed Mo10Nb alloys are MoO2, MoO3, NbO and Nb2O5 while those in (HIP+HR)-processed Mo10Nb alloys are stable MoO3 and Nb2O5 resulting from the oxygen contamination during HR. More importantly, HR crushes large Nb-rich phase particles and elongates equiaxed grain in HIP-processed Mo10Nb alloys. The high temperature during HR leads to the moderate growth of grains. Noteworthy, two weak textures along {001}〈110〉 and {111}<110 > orientations were found in HIP-processed Mo10Nb alloys after HR, which could be caused by the incomplete development of deformation textures and recrystallization textures. This work helps us to clarify the microstructure difference of HIP-processed Mo10Nb alloys before and after HR, which can provide some valuable science and technology guidance for fabrication of refractory alloys by powder metallurgy and the following plastic deformation.

Efficient coding of natural images in the mouse visual cortex

How the activity of neurons gives rise to natural vision remains a matter of intense investigation. The mid-level visual areas along the ventral stream are selective to a common class of natural images—textures—but a circuit-level understanding of this selectivity and its link to perception remains unclear. We addressed these questions in mice, first showing that they can perceptually discriminate between textures and statistically simpler spectrally matched stimuli, and between texture types. Then, at the neural level, we found that the secondary visual area (LM) exhibited a higher degree of selectivity for textures compared to the primary visual area (V1). Furthermore, textures were represented in distinct neural activity subspaces whose relative distances were found to correlate with the statistical similarity of the images and the mice’s ability to discriminate between them. Notably, these dependencies were more pronounced in LM, where the texture-related subspaces were smaller than in V1, resulting in superior stimulus decoding capabilities. Together, our results demonstrate texture vision in mice, finding a linking framework between stimulus statistics, neural representations, and perceptual sensitivity—a distinct hallmark of efficient coding computations.

Fabric handling evaluation of woven shirting fabrics by the fabric touch tester

A fabric touch tester is a novel instrument with fabric handling properties. Its principal advantage is that the device has integrated modules for compression, surface friction, and thermal and bending properties. This module integration simplifies the testing process, and provides an efficient measurement method, and a comprehensive physical index. This study focused on woven fabrics for dress shirts. The fabric samples comprised three groups with various yarn compositions – that is, cotton, polyester, and wool. Sample group 1 was composed of cotton, polyester, and blended yarns; sample group 2 mainly compared the effect of twist yarns on the fabric touch; and sample group 3 was composed of wool and blended yarns with polyester. The handling properties were assessed by compression work and the compression recovery rate for the compression attributes. The results revealed that fabric (T100p1) with high twist-level yarns had a higher value of compression work (242.56 gf*mm2), and the texture type may affect the compression characteristics more significantly than the blending ratio. The fabric touch tester can also distinguish small changes in the compression properties of samples (0.43–0.71), the maximum heat flux and surface roughness amplitude for the thermal and surface roughness properties. The results revealed that the maximum heat flux value of all the samples in this study was 1109 Wm−2, the sample C100 using pure cotton yarn had the highest maximum heat flux value (1270 Wm−2). Moreover, the sample W100 with 100% wool fiber yarn had the highest surface roughness amplitude in the warp direction (81 μm) and surface roughness amplitude in the weft direction (67 μm). Finally, the bending average rigidity was used to assess the bending performance of the fabric samples. These fabric touch tester indicators were applied to analyze the fabric handling characteristics of woven shirting fabrics, and perform cross-analysis among samples.

Agroclimate‐centric irrigation water quality guidelines

AbstractThe suitability of a given water source for irrigation warrants the diagnosis of potential salinity, sodicity and toxicity hazards. Region‐specific irrigation water quality standards and guidelines formulated worldwide are too conservative. After a comprehensive assessment of newer insights from re‐analysis of the available data and examination of the associated evidence covering diversified conditions of saline water use, existing guidelines are updated to adjust for site‐specific conditions. The updated versions for rating both saline and alkali waters include the chemical composition of irrigation waters, soil type (texture, clay mineralogy), salt tolerance rating of crops and rainfall for broader adaptability. As modified by soil texture and rainfall, crop salt tolerance is the decisive factor for fixing upper salinity limits in hyper‐arid, arid, semi‐arid and semi‐humid regions. The customized recommendations include conjunctive use, leaching/rainfall management, irrigation methods, ionic ratios, fertilizers and manures. Guidelines for sodic/alkali waters are based on both crop responses and sodicity‐induced water infiltration problems. The amendment requirements stand defined. In view of the increasing water scarcity, the established guidelines are expected to promote saline and alkali water irrigation in arid and semi‐arid regions while safeguarding the environment.

F. Schubert's Vocal Cycle “Die schöne müllerin” as Teaching Aid for the Professional Training of Concert Pianists

The article analyzes F. Schubertʼs vocal cycle Die schöne Müllerin from the point of view of its potential for professional training of pianists-accompanists. We are talkind about the development of an artistic concept of performing interpretation, the relationship between poetic and musical components, between vocal and piano parts, the types of ensemble texture and development of the ensemble qualities of a vocalist and pianist. It is concluded that the piano part plays not only the role of voice support here, but is also an important constructive component of the composition. The elements of instrumental figurativeness give to music visibility and tangible reality. They are associated with the show of the image of the Brook, as well as the reproduction of various sounds. Accompaniment is also important from the viewpoint of the ladoarmonic and thematic processes of the cycle. Highlighting the most expressive short melody on the piano, then Schubert develops it into the vocal part. The accompaniment with its own intonative material sometimes seems relatively dependent of the vocalist's part, offering only harmonic support although, often the piano part contains intonative material, equivalent to the vocal one. Work on the proposed cycle, gives to pianists-acompanists an excellent opportunity to develop technical and working qualities in ensemble, stimulate their imagination, etc. Piano accompaniment is likewise important from the outlook of the modal-harmonic and thematic processes of the cycle.

First occurrence of dumortierite in Croatia: its chemical composition and appearance as an igneous mineral in leucogranite-hosted pegmatite

In this article, dumortierite from Croatia is described for the first time. Dumortierite formed in a pegmatite dyke cutting through Cretaceous two-mica leucogranite of the magmatic-metamorphic complex of Mt. Moslavačka Gora. The pegmatite dyke shows a magmatic mineral association of coarse-grained quartz, orthoclase, microcline and albite, less abundant muscovite, biotite, pinkish andalusite and blue-coloured prismatic dumortierite I crystals. Subsequent alteration by titanium-rich hydrothermal fluids led to partial replacement of dumortierite I and andalusite by secondary fibrous to acicular purple dumortierite II enriched in Mg and Ti. During temperature decrease perthite developed in feldspars and at a still later stage, sericite partially replaced not only feldspars but also andalusite and both types of dumortierite along grain boundaries and cracks. Final alteration at very low temperatures caused formation of clay minerals at the expense of feldspars. According to mineral chemical analyses, the feldspars are represented by albite and K-feldspar with a low albite component. Biotite corresponds to annite and its subhedral shape and chemical composition point to magmatic crystallisation from a peraluminous melt derived from a crustal source. Coarse muscovite flakes contain 1.31-1.48 wt.% FeO and 0.56-0.70 wt.% TiO2. Their Na/(Na+K) ratios (0.08–0.09) prove a magmatic origin, whereas lower ratios in sericite (0.04–0.06) indicate formation during retrogression. Magmatic muscovite is in textural equilibrium with andalusite, also implying an igneous origin for the latter, which belongs to the S3 textural type of andalusite in felsic igneous rocks. Electron microprobe analyses clearly show a strong positive correlation between Si tetrahedral deficiency (3-Si) and the sum of Al+Ti, (R2= 0.85) in both types of dumortierite, implying Al replacement by Ti. However, Al replacement by Ti is not restricted to Al in the octahedral position, as generally accepted, but most probably also in the tetrahedral position. Distinct pleochroic colours in dumortierite are usually explained by the [Fe/(Fe+Ti)]x100 factor, but according to this study, elevated Mg contents stabilize red to violet coloured dumortierite at higher [Fe/(Fe+Ti)] x100 factors than those previously suggested.

A biocompatible NPK+Fe+Zn slow release fertilizer: synthesis and its evaluation in tomato plant growth improvement

Slow-release fertilizers (SRFs) play an essential and necessary role in sustainable agriculture. Using slow-release and environment friendly fertilizers can increase the growth of plants and reduce the loss of nutrients. Considering the deficiency of iron (Fe) and zinc (Zn) in calcareous soils, a slow-release fertilizer was prepared based on the polymeric nanocomposite, which contains NPK, Fe, and Zn. Its potential was evaluated on tomato plant growth by conducting an experiment in a factorial completely randomized design with three replications. Two levels of salinity (2 and 5 ds m−1, two types of soil texture) clay loam and sandy loam) and five levels of fertilizers were examined in the experiment. To this, the graphene oxide-chitosan coated-humic acid@Fe3O4 nanoparticles (Fe3O4@HA@GO-Cs), and the graphene oxide-chitosan coated-ammonium zinc phosphate (AZP@GO-Cs) were used as Fe and Zn sources, respectively. Then, the optimal Fe and Zn fertilizers in the presence of urea, phosphorus, and potassium slow- release fertilizers (SRF) were investigated under greenhouse conditions. The results indicated that the best improvement in growth and nutrient uptake in plants was achieved by using the SRF. Notably, in the shoots of tomato plants, the nitrogen, phosphorus, potassium, Fe, and Zn concentration increased by 44, 66, 46, 75, and 74% compared to the control. The use of nanofertilizer can be an effective, biocompatible, and economical option to provide Fe and Zn demand in plants.

Unveiling the dynamic of nitrogen through migration and transformation patterns in the groundwater level fluctuation zone of a different hyporheic zone sediment

This study investigates the impact of water levels and soil texture on the migration and transformation of nitrate (NO3−-N) and ammonium (NH4+-N) within a soil column. The concentrations of NO3−-N gradually decreased from an initial concentration of 34.19 ± 0.86 mg/L to 14.33 ± 0.77 mg/L on day 70, exhibiting fluctuations and migration influenced by water levels and soil texture. Higher water levels were associated with decreased NO3−-N concentrations, while lower water levels resulted in increased concentrations. The retention and absorption capacity for NO3−-N were highest in fine sand soil, followed by medium sand and coarse sand, highlighting the significance of soil texture in nitrate movement and retention. The analysis of variance (ANOVA) confirmed statistically significant variations in pH, dissolve oxygen and oxidation–reduction potential across the soil columns (p < 0.05). Fluctuating water levels influenced the migration and transformation of NO3−-N, with distinct patterns observed in different soil textures. Water level fluctuations also impacted the migration and transformation of NH4+-N, with higher water levels associated with increased concentrations and lower water levels resulting in decreased concentrations. Among the soil types considered, medium sand exhibited the highest absorption capacity for NH4+-N. These findings underscore the significant roles of water levels, soil texture, and soil type in the migration, transformation, and absorption of nitrogen compounds within soil columns. The results contribute to a better understanding of nitrogen dynamics under varying water levels and environmental conditions, providing valuable insights into the patterns of nitrogen migration and transformation in small-scale soil column experiments.

Observation of plaid-like spin splitting in a noncoplanar antiferromagnet.

Spatial, momentum and energy separation of electronic spins in condensed-matter systems guides the development of new devices in which spin-polarized current is generated and manipulated1-3. Recent attention on a set of previously overlooked symmetry operations in magnetic materials4 leads to the emergence of a new type of spin splitting, enabling giant and momentum-dependent spin polarization of energy bands on selected antiferromagnets5-10. Despite the ever-growing theoretical predictions, the direct spectroscopic proof of such spin splitting is still lacking. Here we provide solid spectroscopic and computational evidence for the existence of such materials. In the noncoplanar antiferromagnet manganese ditelluride (MnTe2), the in-plane components of spin are found to be antisymmetric about the high-symmetry planes of the Brillouin zone, comprising a plaid-like spin texture in the antiferromagnetic (AFM) ground state. Such an unconventional spin pattern, further found to diminish at the high-temperature paramagnetic state, originates from the intrinsic AFM order instead of spin-orbit coupling (SOC). Our finding demonstrates a new type of quadratic spin texture induced by time-reversal breaking, placing AFM spintronics on a firm basis and paving the way for studying exotic quantum phenomena in related materials.

FLATTENING COMPLEX ARCHITECTURAL SURFACES: PHOTOGRAMMETRIC 3D MODELS CONVERTED INTO 2D MAPS

Abstract. The paper describes a workflow to flatten 3D photogrammetric models of undevelopable surfaces into unfragmented 2D texture maps. The aim is to create a texture map with reduced fragmentation compared to typical photogrammetric texture files associated with 3D models. Geometric reformatting of the mesh is required to achieve an unfragmented final texture image with enough visual quality to allow for its use in 2D editing software (e.g., Photoshop, Illustrator, etc.). With a lighter model and defragmented texture, graphic documentation of conditions, treatments, or other relevant information can be performed directly. The approach considers both simple and complex architectural surfaces, with particular attention to elements that cannot be developed without introducing distortions. In the case of historic buildings, such surfaces constitute the majority, especially in the case of decorative elements and irregular vaulted systems. The approach extends to full 3D models, particularly those where orthomosaics would result in stretched details. We will discuss two methods: the first is particularly suitable when the photogrammetric project (oriented images) is still available, and the second applies to generic 3D models without the availability of the original images.

Synergetic effect of oleophilic textured surfaces and MoS2 on the tribological properties of Ti-6Al-4V alloy under dry and lubricated sliding conditions

Abstract In the present work, surface modification of Ti-6Al-4V alloy was carried out using Laser surface texturing (LST). The investigation aims to explore the synergetic impact of LST and molybdenum disulfide (MoS2), as a solid lubricant, on the tribological properties of Ti-6Al-4V alloy. Three types of LST textures (Circular, triangular, and square textures) were created on the Ti6Al4V alloy. Subsequently, tribological tests were conducted on a universal tribometer (ball-on-disc), at a load of 20 N with a frequency of 15 Hz. The worn surface was analyzed using various methods, including optical microscopy, 3D-profilometer, FESEM, EDAX analysis, and Raman spectroscopy. The study compared the coefficient of friction (COF) and wear behavior of un-textured surfaces (UTS) with those of textured surfaces (TS) under both dry sliding conditions (DSC) and lubricated sliding conditions (LSC). The results demonstrated a significant reduction in the COF and wear coefficients on the TS. Specifically, the circular texture exhibited significant results with a 10.30%, 10.42%, and 28.80% decrease in COF and a remarkable reduction of 39.22%, 47.51%, and 77.90% in wear coefficients compared to the UTS tested under DSC and LSC (using PAO-4 and PAO-4 + 1% wt MoS2). Severe abrasion, adhesion, and delamination as the primary wear mechanisms were observed on the UTS and TS under DSC, while the LSC was characterized by mild adhesive and delamination wear on the UTS and TS. The carbon layer formation and concentration of Mo and S particles resulted in lower friction and wear coefficients for the UTS, and TS under LSC (PAO-4 + 1% wt MoS2). The analysis indicated that the use of LST and solid lubricant nanoparticles on a Ti-6Al-4V alloy would result in improved service life and better endurance in cutting tools and tribo-mating parts.

The Role of Peritectic Biotite for the Chemical and Mechanical Differentiation of Felsic Plutonic Rocks (Western Adamello, Italy)

Abstract The volcanic–plutonic connection plays a fundamental role for magmatic systems, linking crystallising plutons, volcanic activity, volatile exsolution and ore deposits. Nonetheless, our understanding of the nature of these links is limited by the scarcity of continuous outcrops exhibiting clear relationships between the plutonic roots that feed its volcanic counterpart. One way to better characterise the volcanic–plutonic connection is to quantify the amount of melt segregation within crystallising tonalitic to granodioritic plutonic rocks, and to compare those with recent silicic eruptions. Here we investigate the processes of interstitial melt segregation in the calc-alkaline Western Adamello pluton (Italy). The Western Adamello tonalite exhibits a coarse-grained, equigranular texture and is mainly composed of hornblende partially replaced by biotite, plagioclase, quartz and alkali feldspar. Within the tonalites, several types of schlieren textures, crystal accumulation zones and dikes are found, comprising: (i) hornblende-biotite-gabbros, spatially related to (ii) plagioclase- and quartz-rich leucotonalites; and (iii) quartz-, albite- and alkali-feldspar-rich domains forming aplitic to pegmatitic dikes indicative of melt segregation and extraction. Hornblende, biotite and plagioclase phenocrysts have essentially the same compositional range in the tonalites, gabbros and leucotonalites. Together with field observations, this indicates that deformation-driven crystal–melt segregation controls the modal variation within the host tonalite. The calculated melt in equilibrium with the primitive amphiboles has the same trace element composition as the host tonalite to within 5% to 10%, indicating that the tonalite did not experience substantial melt loss. Quantitative modal compositions and crystallisation–differentiation calculations suggest that the evolution of the tonalite is controlled by plagioclase and hornblende crystallisation followed by a biotite-forming peritectic reaction. This peritectic reaction can be written as melt1 + amphibole = melt2 + biotite + quartz + plagioclase and decreases the remaining interstitial melt fraction from 40% to 15% in a small temperature interval (~50°C), therefore, reducing the temperature window for large-scale melt segregation. The biotite-forming reaction initiates in weakly corundum-normative compositions in low to intermediate K calc-alkaline differentiation (e.g. Western Adamello and Peninsular Ranges Batholith, California), whereas it seems absent in intermediate to high K, clinopyroxene-normative melts (e.g. Tuolumne Intrusive Suite, California). This difference is likely controlled by the initial aluminium saturation index and the differentiation path of the parental melt within the middle to lower crust. Textural observations and mass balance models indicate that 75% to 88% plagioclase and quartz and 30% to 70% interstitial melt was mechanically removed from the Western Adamello tonalite to form hornblende-biotite-gabbros, whereas the leucotonalites result from the accumulation of 40% to 80% plagioclase and quartz. Of the emplaced 300 to 400 km3 of Western Adamello tonalite, only about 0.8 to 2.4 km3 represent rock types related to physical segregation processes, indicating limited melt extraction. Such crystal–melt segregation processes in tonalitic to granodioritic plutons are observed worldwide and facilitate the extraction of granitic liquids. This mechanism as observed in the Western Adamello tonalite potentially contributes to the accumulation of crystal-poor rhyolites and the segregation of metal-rich brines.