Scale Morphology Research Articles

Optimizing the High-Temperature Oxidation Resistance of Nb-Si-Based Alloys by Adding Different Ti/Mo/Hf Elements

As a candidate material for turbine blades in aerospace engines, Nb-Si-based alloys have attracted significant research attention due to their high melting point and low density. However, their poor high-temperature oxidation resistance limits practical applications. Different alloying elements, including Ti, Mo, and Hf, were added to Nb-Si-based alloys to study the microstructural evolution of alloys. Additionally, the oxidation behavior and the oxidation kinetics of different alloys, as well as the morphology and microstructure of oxide scale and interior alloys at 1523 K from 1 h to 20 h were analyzed systematically. The current findings indicated that the Mo element is more conducive to promoting the formation of high-temperature precipitates of β-Nb5Si3 than the Ti and Hf elements. Inversely, the Ti element tends to cause the transition from high-temperature-phase β-Nb5Si3 to low-temperature-phase α-Nb5Si3, while the Hf element improves the appearance of the γ-Nb5Si3 phase but inhibits the other phases and refines the primary Nbss effectively. Noteworthily, compared with the oxidation weight gain of different alloys, Nb-16Si-20Ti-5Mo-3Hf-2Al-2Cr alloy has excellent high-temperature oxidation resistance, in which the oxidation products are TiNb2O7, Nb2O5, SiO2, TiO2, and HfO2. It can be determined that in the oxidation process, the Ti element will preferentially form an oxide film of TiO2, thereby wrapping around the matrix phases, protecting the matrix, and improving the antioxidant capacity, while the Hf element can form an infinite solid solution with the matrix and consume the small number of oxygen atoms entering the matrix, so as to achieve the effect of improving the oxidation resistance.

Scale Surface Topography of a Vulnerable Cyprinid Fish, Schizothorax plagiostomus From Kashmir Himalayas Using Scanning Electron Microscopy (SEM).

Scanning electron microscopy (SEM) has significantly advanced morphological studies, particularly in the investigation of fish scale structures. This technique has unveiled intricate architectural details that are crucial for fish identification and classification. In this study, macro and microscopic analyses were employed to examine the scale morphology of Schizothorax plagiostomus, a vulnerable cyprinid fish from Kashmir, focusing on two body regions (region below dorsal fin and above lateral line). The general scale type observed in S. plagiostomus was cycloid. Two types of shapes, viz., polygonal and cordate, were reported in this species. The rostral margin of the scales displayed round and waved forms. The scales exhibited a small and round focus, which was antero-centrally positioned. The scales featured narrow or wide grooves (radii) categorized into three types: primary, secondary, and tertiary, present across all four scale fields (anterior, posterior, dorsal and lateral), forming a tetra-sectioned type. Circuli, arranged in circular patterns around the focus, were present, which were densely placed in the anterior and lateral fields and widely spaced in the posterior field. Notably, lepidonts on the circuli and chromatophores on the posterior margin were absent in this species. These scale characteristics and their morphologies offer a valuable tool for the identification, classification, and phylogenetic analysis of various freshwater fish species and genera.

Epidermal scale growth, allometry and function in non-avian dinosaurs and extant reptiles.

Epidermal scales in sauropsids perform a wide array of biological functions, which can relate to their shape and size. Accordingly, growth-related changes in scale morphology may reflect distinct functions between juvenile and adult individuals, such as use in mating interactions. Such patterns are poorly explored in both extant reptiles and non-avian dinosaurs, limiting functional interpretations. Here, we investigate scale growth in the ornithischian ceratopsid Chasmosaurus belli and hadrosaurid Prosaurolophus maximus by comparing scale morphologies between juveniles and adults of each taxon. Scale shape is generally consistent across growth stages in both taxa, and changes in C. belli feature scale length cannot reject isometry. However, there is a greater increase in C. belli feature scale width. In practical terms, the magnitude of these size differences rejects the hypothesis that feature scale morphology played a role in mating interactions, suggesting instead that their size was largely non-adaptive. To contextualise the patterns in the sampled dinosaurs, we assessed scale growth and allometry using an ecologically diverse sample of eight extant reptile species belonging to Crocodylidae, Scincidae, Elapidae and Pythonidae. While isometry is the overall most frequent pattern of scale growth in our sample of extant reptiles, most species demonstrate positive scale allometry in at least one area of their bodies, which is likely a response to changing body proportions. Scale shapes in the studied extant species, as in both dinosaurs, are largely retained through growth. This study provides the first detailed assessment of skin growth in non-avian dinosaurs, supporting morphological stasis in the growth of most of their scales.

Yeast aging from a dynamic systems perspective: Analysis of single cell trajectories reveals significant interplay between nuclear size scaling, proteasome dynamics, and mitochondrial morphology.

Yeast replicative aging is cell autonomous and thus a good model for mechanistic study from a dynamic systems perspective. Utilizing an engineered strain of yeast with a switchable genetic program to arrest daughter cells (without affecting mother cell divisions) and a high throughput microfluidic device, we systematically analyze the dynamic trajectories of thousands of single yeast mother cells throughout their lifespan, using fluorescent reporters that cover a range of biological processes, including some major aging hallmarks. We found that the markers of proteostasis stand out as most predictive of the lifespan of individual cells. In particular, nuclear proteasome concentration at middle age is a good predictor. We found that cell size (measured by area) grows linearly with time, and that nuclear size grows in proportion to maintain isometric scaling in young cells. As the cells become older, their nuclear size increases faster than linear and isometric size scaling breaks down. We observed that proteasome concentration in the nucleus exhibits dynamics very different from that in cytoplasm, with much more rapid decrease during aging; such dynamic behavior can be accounted for by the change of nuclear size in a simple mathematical model of transport. We hypothesize that the gradual increase of cell size and the associated nuclear size increase lead to the dilution of important nuclear factors (such as proteasome) that drives aging. We also show that perturbing proteasome changes mitochondria morphology and function, but not vice versa, potentially placing the change of proteosome upstream of the change of mitochondrial phenotypes. Our study produced large scale single cell dynamic data that can serve as a valuable resource for the aging research community to analyze the dynamics of other markers and potential causal relations between them. It is also a useful resource for building and testing physics/AI based models that identify early dynamics events predictive of lifespan and can be targets for longevity interventions.

Precise Control Over Crystallization Kinetics by Combining Nucleating Agents and Plasticizers for 20.1% Efficiency Organic Solar Cells

AbstractObtaining controllable active layer morphology plays a significant role in boosting the device performance of organic solar cells (OSCs). Herein, a quaternary strategy, which incorporates polymer donor D18‐Cl and small molecule acceptor AITC into the host D18:N3, is employed to precisely modulate crystallization kinetics for favorable morphology evolution within the active layer. In situ spectroscopic measurements during film‐formation demonstrate that while D18‐Cl works as a nucleator to promote aggregation of D18 and foster donor/acceptor intermixing, AITC has exactly the opposite impact on aggregation of N3 and intermixing kinetics of donor and acceptor, working as a plasticizer. The mutually compensational effect of the dual‐guests, as a result, enables synergistic control over fibrillar networks, multi‐length scale morphology, and vertical phase distribution, leading to optimized 3D morphology for greatly enhanced exciton dissociation and charge transfer, suppressed charge recombination, and reduced energy loss. Consequently, the quaternary OSCs based on D18:D18‐Cl:N3:AITC achieved an excellent power conversion efficiency of 20.1%, which represents one of the highest efficiencies for single‐junction OSCs. This work presents an effective strategy to precisely regulate crystallization kinetics toward advanced morphology control for high‐performance OSCs.

Effect of Surface Finish on CO2 Corrosion of Low-Alloy Steel in Simulated Sea Water and Well Environments

The study investigates the influence of surface finish on corrosion of a grade API L80 low-alloy steel. Samples of this steel with different surface finishes produced by rough mechanical grinding (RG sample) or by finer polishing (FP sample) have been studied after exposure to corrosive environments. It is found that the dissolution rate is one to two orders of magnitude higher for the RG sample with a rougher surface than for the FP samples with a smoother surface. Scanning electrochemical microscopy shows selective corrosion of the RG sample, while the FP sample undergoes slow uniform corrosion, followed by localized corrosion after long exposure. A detailed analysis of the corrosion process indicates that in a simulated well environment containing Fe2+ and Ca2+ ions, fast precipitation of CaCO3 on the rougher surface initially reduces the corrosion rate. However, once a protective scale starts forming on the surface, the effect of surface finish on corrosion resistance becomes less significant. The scale morphology and phase composition vary between the samples with the different surface finishes.

Patanwadi sheep wool profile: yield, morphology and physico-mechanical properties.

The Patanwadi sheep breed, an indigenous species from Gujarat, India, is primarily reared for wool, mutton, and household milk production. Patanwadi wool attracts lower prices mainly because of its coarseness. However, complete wool profiling of Patanwadi sheep has remained unknown to date. This study comprehensively analyzes clean fiber (scouring) yield, morphology, elements, and physico-mechanical properties of Patanwadi wool. The physico-mechanical properties determined include fiber diameter, staple length, crimp per centimeter, color, bundle strength, elongation, and modulus. Scanning electron microscopy analysis reveals distinct fiber scale morphology, with sharper scales in male sheep wool compared to female counterparts. Additionally, energy-dispersive X-ray analysis confirmed the presence of sulfur and trace levels of calcium within Patanwadi wool fibers. Results indicate a statistically significant effect (P < 0.05) of animal sex on the physico-mechanical parameters, including elongation, modulus, moisture content, and moisture regain. Given its coarse nature and high medullation, Patanwadi wool is less suited for fine apparel but holds promise as an insulation material and in other innovative coarse wool applications. This research broadens the utility of Patanwadi coarse wool for value-added practical end uses, ensuring sustainability and yielding better realization of the wool.

Phenotypic Variation in Cone Scales and Seeds as Drivers of Seedling Germination Dynamics of Co-Occurring Cedar and Fir Species

The intraspecific trait variations in the reproductive structures and early growth of seedlings may be critical in determining further regeneration. However, modularly built organisms, such as trees, challenge our notion of the phenotype concept, as the arrays of nonidentical homologous organs, such as seed-bearing cone scales and seeds, depending on the individual capacity to produce phenotypically variable arrangements, but they also reflect abiotic selective effects. We investigated the variability in cone scale morphology, seed traits, and germination dynamics in coexisting fir (Abies marocana) and cedar (Cedrus atlantica) trees from northern Morocco. We quantified the degree of trait overlap in two co-occurring populations of both species, as a measure of population/species functional similarity. Cone scale size and seedling growth rate were species-dependent traits, as 70%–80% of the variance was explained by the species, while only 0%–2% was explained by the population. Conversely, seed weight was a tree-dependent trait, as 70% of the variation was observed among trees, while the species only explained 20% of the variation, and the contribution of the population was negligible. Species and populations showed the same characteristics in the correlations between variables, supporting different magnitudes but a constant relationship. Substantial variations in seed weight and early seedling growth occur concurrently among cones of a single tree, independently of the tree species or population. Further studies should consider both phenotype selection and inheritance of traits’ variance on the establishment, survival, and growth of seedlings in A. marocana and C. atlantica in nurseries and reforestation sites to improve adaptive capacity to changing environmental conditions.

Exploring the factors shaping microscopic morphological traits: insights from the chrysophycean genus Synura (Stramenopiles)

ABSTRACT Synura represents a common freshwater protist genus known for producing morphologically diverse silica scales with species-specific secondary structures. In this study, we analysed 19 scale-bearing morphological traits across over 700 genetically verified records, spanning a broad environmental gradient in Europe. Focusing on Synura from section Petersenianae, we identified 29 species-level lineages, 13 of which had not been previously described. Interestingly, while species diversity increased northwards, morphological trait diversity exhibited the opposite trend, being higher in southern Europe. This suggests that abiotic factors play a significant role in shaping these traits, which are differently responsive to gradients than taxonomic diversity. We observed non-random distribution of scale morphological traits, influenced by abiotic factors such as temperature, precipitation and pH. Scale elongation appears to be an adaptation for living in oligotrophic waters with reduced sunlight availability, while the increasing distance between struts likely reflects an adaptation to low silica concentrations. Notably, specific morphological traits may provide more informative insights into environmental drivers than taxonomic units. The study sheds light on the intricate relationship between environmental conditions and the morphology of silica scales, emphasizing the importance of considering both taxonomic and morphological diversity in ecological research.

Visual target tracking based on fractional – order bidirectional hybrid attentional feature fusion

This paper mainly designs and implements target tracking based on fractional – order feature fusion to solve tracking drift and tracking box jumping in complex scenes. Firstly, the starting point and overall structure of the model design were introduced. Secondly, in response to the low information utilization of the feature extraction network in the target tracking framework at the local scale of the target, a fractional – order node function based attention CNN hybrid attention extraction module was proposed to improve the robustness of target tracking. Finally, overall performance was quantitatively and qualitatively evaluated on multiple evaluation datasets with various advanced trackers. The results showed that the algorithm proposed in this paper had a high tracking advantage under severe changes in scale morphology, dynamic blurring, and similar interference attributes.

New material of the Early Devonian sarcopterygian Styloichthys changae illuminates the origin of cosmine

The Early Devonian sarcopterygian Styloichthys changae provides substantial information to resolve the phylogenetic relationships of early sarcopterygians. Its dermal bones show a cosmine surface with relatively large pores and a unique histological condition, which is essential to understanding the early evolution of the dermoskeleton in sarcopterygians. However, more detailed histological information on this taxon is needed. Here, we present new data about the morphology and histology of dermal bones and scales of S. changae based on two semi-articulated specimens. The scales bear parallel ridges and relatively large pores on their external surface resembling those of the dermal bones, showing an intermediate condition between stem sarcopterygians and crown sarcopterygians. We recognize three stages in the growth series of S. changae scales. The growth pattern of the cosmine layer undergoes two significant changes: from a superpositional pattern to a continuous areal pattern and then to a discontinuous areal pattern. In addition, the new data indicate that the pore-canal system predates the enamel-dentine complex of cosmine. This work supports the hypothesis that the cosmine arose step by step in sarcopterygians and provides more details on the evolutionary development pattern of cosmine.

Species of the thecate dinoflagellate genus Heterocapsa (Dinophyceae; Heterocapsaceae) from the tropical Mexican Pacific, with special reference to two new records in the area and the ultrastructure of Heterocapsa borneoensis

Background: The thecate dinoflagellate genus Heterocapsa encompasses marine planktonic species, which have been poorly studied in the Mexican Pacific coasts. Question: Is it possible to extend the knowledge of the genus Heterocapsa in the Mexican Pacific by means of different study techniques? Study sites: Acapulco Bay, Guerrero, Mexico During November 2021 and March 2024. Methods: Establishment of cultures, morphological analysis by light microscopy and molecular identification using the region D1-D2 (LSU rDNA) Results: Five strains belonging to species of the genus Heterocapsa were established. The strains were identified as H. borneoensis, H. iwatakii and Heterocapsa sp., respectively. Each strain was morphologically characterized by light microscopy, highlighting characters such as the overall shape of the cell, proportion of the episome and hyposome, shape and position of the nucleus and number and position of the pyrenoids. Additionally, the morphology of the body scales and the ultrastructure of H. borneoensis were studied. Molecular identification of two species was confirmed by analysing the D1-D2 region (LSU rDNA). The phylogeny showed that sequences obtained in this study clustered with previous sequences of H. borneoensis and H. iwatakii. Conclusion: This study confirmed the first record of H. borneoensis and H. iwatakii from the eastern Pacific Ocean.

A novel anti-scaling and protection coating based on hollow periodic mesoporous organosilica encapsulated with scale inhibitor

A novel anti-scaling and protection coating based on hollow periodic mesoporous organosilica encapsulated with scale inhibitor

Scale pattern of five species of Zeiformes (Teleostei)

AbstractThe order Zeiformes comprises a small order of predominantly deep‐sea fishes. However, little information is available on their morphology, such as squamation. Therefore, in the present study, we analysed and described the squamation pattern and scale morphology of five species of Zeiformes occurring on the Brazilian coast: Allocyttus verrucosus, Grammicolepis brachiusculus, Xenolepidichthys dalgleishi, Zenion hololepis and Zenopsis conchifer. Our analysis revealed greater morphological diversity than previously reported for this order. All species, except the scaleless Zenopsis conchifer, presented cycloid scales of spinoid subtype. Grammicolepis and Zenion presented exclusively scales of the spinoid subtype, whereas both Allocyttus and Xenolepidichthys also displayed true cycloid subtype. A. verrucosus is characterised by two distinct groups of scales of different sizes that form scale clusters. G. brachiusculus and X. dalgleishi presented a unique vertically elongated scale covering most of the body. Small bony plates were observed at the dorsal‐ and anal‐fin bases of G. brachiusculus, X. dalgleishi and Z. hololepis. The variation observed is putatively useful for the systematics of the order.

Ревизия таксономического статуса Mallomonas multiunca var. pocosinensis на основании ультраструктуры кремнеземных покровов клетки, Mallomonas pocosinensis comb. et stat. nov.

The ultrastructure of the silica scales and bristles of two morphologically similar taxa, Mallomonas multiunca var. multiunca and M. multiunca var. pocosinensis, was compared. Based on the revealed differences in the morphology of scales and bristles, the taxonomic status of the species M. multiunca var. pocosinensis was revised and a new taxonomic combination, Mallomonas pocosinensis comb. stat. nov., was proposed. Аn updated description and original SEM micrographs are provided.

A century later: a new species of Mastigoceras Handschin, 1924 (Collembola, Orchesellidae), with morphological and systematic updates on the genus.

Mastigocerascamponoti Handschin, the sole member of its genus and the Mastigocerini tribe, exhibits unusual dorsal chaetotaxy compared to other Orchesellidae. This includes a reduction in dorsal macrochaetotaxy and a secondary covering of fusiform scales intermixed with ciliate microchaetae. Despite three redescriptions, Mastigoceras chaetotaxy remains poorly understood, with no data on tergal sensilla patterns or dorsal macrochaetae homology. Here, the genus is revisited by describing a new Brazilian species a century after the original description of M.camponoti, based on morphological depiction combined with the use of DNA barcoding, Mastigocerashandschini Rodrigues, Souza & Bellini, sp. nov. The two species are differentiated by a few and unusual aspects of the dorsal chaetotaxy, especially scales distribution, and may be considered as pseudocryptic taxa. Our study of tergal sensilla formula, scales morphology, and distribution in Mastigoceras reveals no clear morphological support for placing Mastigocerini within Heteromurinae.

Description of the new species Mallomonas okhapkinii (Synurales, Chrysophyceae) based on morphological and molecular data

This paper describes a new species of Mallomonas discovered in a swamp area in Russia. The species was identified based on scale morphology, examined using scanning and transmission electron microscopy, and subjected to molecular analysis. The new species, Mallomonas okhapkinii sp. nov., belongs to the section Planae and is most similar in scale and bristle ultrastructure to M. matvienkoae sensu stricto. Phylogenetic analysis, performed using a concatenated dataset of nuclear-encoded small subunit rRNA and plastid-encoded rbcL genes, revealed that the strains of the new species form a distinct clade with high statistical support, closely related to the clade of M. paragrandis and M. sorohexareticulata. This species was found in only one habitat.

Synthesis and evaluation of an environmentally friendly phosphorus-free and nitrogen-free polymer as a scale and corrosion inhibitor

Synthesis and evaluation of an environmentally friendly phosphorus-free and nitrogen-free polymer as a scale and corrosion inhibitor

Water vapor oxidation of SiC layer of tristructural isotropic particles

AbstractTristructural isotropic (TRISO) fuel particles, developed for use in high‐temperature gas‐cooled nuclear reactors, can be subjected to oxidizing environments in off‐normal accident scenarios. In this study, surrogate TRISO fuel particles were oxidized at 1000–1350°C for 4 h in 20 kPa water vapor atmosphere balanced with ultrahigh‐purity helium gas. The oxide scale morphology and thickness were studied via scanning electron microscopy, focused ion beam, and transmission electron microscopy. The oxide thickness increased as the oxidation temperature was increased. Although the oxide scale at 1000°C was completely amorphous, pockets of crystalline oxide were observed on particles oxidized at 1200 and 1300°C. Kinetic analysis was performed to deduce the oxidation mechanism by determining the apparent activation energy using linear regression analysis. The oxidation mechanism was consistent for temperatures from 1000 to 1200°C with an activation energy of 412.4 ± 8.8 kJ/mol. The activation energy then dropped to approximately 201 ± 7.1 kJ/mol for temperatures 1200–1350°C. Therefore, there is a change in oxidation mechanism at ∼1200°C. This change is attributed to the existence of a network of significant bubbles in the oxide layer at higher temperatures, which serve as rapid diffusion pathways for the transport of oxidants from the surface to the SiC/SiO2 interface, instead of relying on the bulk diffusion through the SiO2 layer at lower temperatures where only small bubbles are present along the SiC/SiO2 interface.

Mallomonas enigmata sp. nov. (Synurales, Chrysophyceae), an Eocene fossil species with a second and unique scale morphotype attached to its cyst

ABSTRACT A new and intriguing fossil Mallomonas species, M. enigmata, was uncovered from 10 strata in the Eocene Giraffe Pipe locality. The new species represents an ancient member of the section Punctiferae, and based on scale and bristle morphology is most closely related to the modern congener, M. nieringii. M. nieringii is a rare species known from a suite of acidic waterbodies on the Cape Cod peninsula, Massachusetts, USA. Only a few modifications of the body scales differ between M. enigmata and M. nieringii, and the new taxon was uncovered from a section of the Giraffe Pipe maar lake representing a shallow and acidic waterbody. Cysts of M. enigmata are oval, with a small pore surrounded by a narrow hyaline zone. The anterior ~ ¼ of the cyst surrounding the hyaline zone consists of a series of small, closely spaced, rimmed holes that penetrate the wall. Otherwise, the cyst wall is smooth and unornamented. Unlike any known modern species in the genus, a second type of body scale is produced, but found only attached to the cyst. It is hypothesized that these scales may represent unfinished body scales that became fused to the cyst during its development.