Search Results (131)

The aperture of the towed horizontal line array is limited and the received signal is unstable in a complex ocean environment, making it difficult to distinguish the location of the sound source. To address this challenge, this paper presents a MoELocNet (Mixture of Experts Localization Network) for deep-sea sound source localization, leveraging interference structures in range-frequency domain signals from a towed horizontal line array. Unlike traditional correlation-based methods constrained by time-varying ocean environments and low signal-to-noise ratios, the model employs multi-expert and multi-task learning to extract interference periods from single-frame data, enabling robust estimation of source range and depth. Simulation results demonstrate its superior performance in the deep-sea shadow zone, achieving a range localization error of 0.029 km and a depth error of 0.072 m. The method exhibits strong noise robustness and delivers satisfactory results across diverse deep-sea zones, with optimal performance in shadow zones and secondary effectiveness in the direct arrival zone. Full article

The aim of this study was to determine the connection between oscillations in operating pressure values and the appearance of various irregularities on machined surfaces. Such oscillations are a consequence of the high water pressure generated during abrasive water jet machining. Oscillations in the operating pressure values are periodic, namely due to the cyclic operation of the intensifier and the physical characteristics of water. One of the most common means of reducing this phenomenon is installing an attenuator in the hydraulic system or a phased intensifier system. The main hypothesis of this study was that the topography of a machined surface is directly influenced by the inability of the pressure accumulator to fully absorb water pressure oscillations. In this study, we monitored changes in hydraulic oil pressure values at the intensifier entrance and their connection with irregularities on the machined surface—such as waviness—when cutting aluminum AlMg3 of different thicknesses. Experimental research was conducted in order to establish this connection. Aluminum AlMg3 of different thicknesses—from 6 mm to 12 mm—was cut with different traverse speeds while hydraulic oil pressure values were monitored. The pressure signals thus obtained were analyzed by applying the fast Fourier transform (FFT) algorithm. We identified a single-sided pressure signal amplitude spectrum. The frequency axis can be transformed by multiplying inverse frequency data with traverse speed; in this way, a single-sided amplitude spectrum can be obtained, examined against the period in which striations are expected to appear (in millimeters). In the lower zone of the analyzed samples, striations are observed at intervals determined by the dominant hydraulic oil pressure harmonics, which are transferred to the operating pressure. In other words, we demonstrate how the machined surface topography is directly induced by water jet pressure frequency characteristics. Full article

This study examined the relationship between microhardness, morphology, and phase composition of dental yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), which directly impact their long-term clinical performance and durability. The primary objective was to investigate the effects of yttria content and polishing on the surface properties and hardness of these materials. Samples from ZirCAD Prime, Cercon ht ML, ZIRCONIA YML, and ZirCAD LT were analyzed using Vickers hardness testing, Powder X-ray Diffraction (PXRD), and Scanning Electron Microscopy (SEM). SEM analysis revealed a gradual increase in grain size and porosity with higher yttria content in unpolished samples. Polishing resulted in a relatively uniform surface morphology with observable striations across all samples, subsequently leading to similar Vickers hardness values for all polished samples. PXRD and SEM analyses identified that these similar hardness values were likely due to the predominant monoclinic phase on the surface, induced by polishing. These findings underscore the significant influence of yttria content and polishing on Y-TZP microstructure and surface hardness, highlighting their critical role in the long-term success and clinical applicability of dental restorations. Full article

A small-sized shark was accidentally caught in the coastal waters of southeastern France and abandoned in the port of L’Estaque (Marseille) in May 2024. An autopsy revealed that it was a young female shortfin mako, Isurus oxyrinchus (Rafinesque, 1810). Numerous superficial wounds on the head, back, and flanks, in the form of parallel striations resulting from heavy friction, indicate meshing in a gillnet that provoked the animal’s death by asphyxiation. Its very small size (64.77 cm TL) suggests that this is a newborn individual, leading to the hypothesis that the waters off Marseille could be a nursery area for this species. This observation alone is not enough to prove this point, but it does suggest the need for closer monitoring to validate it. Should the area be proven to play this key role for this critically endangered species, measures to limit fishing pressure would be essential, particularly during the parturition period between February and May. Full article

Two new species of the genus Oxyopomyrmex are described from Spain (Iberian Peninsula). The first belongs to the magnus group—characterized by a head more wide than long—and is distinguished by strongly developed cephalic striations, pale coloration (light brown) and a relatively small body size. To date, it has been recorded in the provinces of Jaén and Granada. The second species is even smaller in size, with very faint cephalic striations and short, triangular propodeal spines—morphological features that clearly set it apart from all previously known species. Its current distribution appears to be restricted to the province of Huelva, near the Atlantic coast, including the iconic Doñana National Park. With these additions, the number of Oxyopomyrmex species known from Spain increases from two to four. To date, sampling efforts have only focused on the southern part of the country, suggesting that additional, undiscovered species may still exist. Full article

Additive manufacturing (AM), especially vat photopolymerization processes such as digital light processing (DLP), enables the production of highly detailed and complex geometries with precise material structure control. In this study, the influence of internal structure on the mechanical properties of PLA resin specimens produced using a DLP 3D printer is investigated. Two designs were analyzed: a fully solid structure and a shell with a Voronoi pattern. Tensile and bending tests revealed that solid specimens exhibited higher strength, while Voronoi structures performed better under bending loading despite lower load-bearing capacity due to their porosity ratio. The developed numerical model, analyzed through different numerical simulations using the Ansys 2025R01 Software package and validated by experimental results, showed a strong correlation between experimental and numerical results that confirmed the reliability of the developed models for preliminary design verification. These models hold significant potential for the design of mechanical and biomedical components, including orthopedic immobilization devices. Microscopic analysis revealed brittle fracture in solid specimens with striations and bubble-shaped irregularities, while Voronoi specimens exhibited fragmented surfaces with clean, brittle failure along structural voids. Based on the results obtained, this research demonstrates how additive manufacturing enables the optimization of mechanical properties and material efficiency through precise control of internal structures. In the future, validated numerical models can be used to check the preliminary designs of different components, which will significantly reduce development costs. Full article

The influence of intrinsic impurities on the formation of band-like inhomogeneities in ZGP single crystals containing two highly volatile elements has been analyzed. It has been shown that the formation of growth bands occurs due to the accumulation of binary phosphides at the crystallization front and is accompanied by the formation of pores in the near-wall region of the ingot. A connection between near-wall pore formation and the presence of growth bands in ZGP has been established. X-ray spectrometry revealed differences in the chemical compositions of “light” and “dark” growth striations, with significant deviations from stoichiometry in these regions. The dark bands exhibited a higher phosphorus content compared to the light bands and showed an increased germanium content in the light bands. Differences in the orientation of crystallographic axes were observed between the light and dark regions. It has been shown that samples containing inclusions of band-like inhomogeneity significantly distort the profile of the radiation passing through and generated in the crystal and lead to pronounced astigmatism. However, in contrast to the extremely negative influence of banded inhomogeneity on the optical properties of single crystals, the influence of growth striations on the radiation resistance of crystals is minimal. Full article

This study systematically investigated the influence of aging temperature variations on the evolution of Cu-rich precipitates and dislocation distribution characteristics in 17-4PH stainless steel through comprehensive electrochemical testing and microstructural characterization. The mechanism by which microstructural features govern electrochemical corrosion behavior was elucidated. Experimental results demonstrated that within the aging temperature range of 480–620 °C, matrix dislocations consistently maintained non-uniform distribution characteristics, though their regional heterogeneity exhibited a decreasing trend with increasing temperature. The precipitation behavior of copper followed an evolutionary sequence: transitioning from dispersed copper precipitates to finely distributed Cu-rich precipitates with high numerical density, ultimately progressing to coarsening and agglomeration. The corrosion resistance of the material initially improved before subsequent degradation, accompanied by a morphological transition of surface corrosion features from characteristic elongated striations to elliptical patterns. Samples aged at 580 °C for 4 h exhibited optimal corrosion resistance. Mechanistic analysis revealed that reduced dislocation density heterogeneity effectively minimized electrochemical potential differences between micro-regions, while elemental segregation induced by Cu-rich precipitates coarsening intensified local electrochemical inhomogeneity. These two mechanisms cooperatively regulated the overall corrosion resistance evolution of the material. Full article

Biodegradable films are a viable alternative to conventional plastics, thereby contributing to environmental pollution reduction. This study investigates the impact of substrate type on the properties of starch-based films produced using a plasticizer-assisted casting method. Four different substrates, namely, glass, copper, copper-free laminate, and Teflon^®, were evaluated, addressing a research gap in which previous studies primarily focused on film composition. The films were analyzed for color, tensile strength, surface free energy, and surface morphology using optical and electron microscopy. The results demonstrated a substrate-dependent impact on surface properties, particularly optical transparency, surface roughness, and adhesion. The films cast on glass and laminate exhibited higher transparency and lower roughness, while copper substrate induced micro-striations and strong adhesion. Teflon^® substrates replicated surface imperfections, which may be advantageous for optical applications, but caused film delamination. Tensile strength did not show statistically significant differences across substrates, although reduced elongation was observed for the films cast on Teflon^®. Water vapor permeability was also not significantly affected, indicating a dominant role of bulk material properties. It averaged 25 kg per day per square meter, which means high vapor permeability. Surface free energy analysis revealed marked variations between top and bottom layers, with values ranging from 35 to 70 mJ·m⁻² depending on the substrate. These findings confirm that the type of casting substrate plays a critical role in determining the surface and optical properties of starch-based films, even at the laboratory scale. This study provides new insights into substrate–film interactions and establishes a foundation for optimizing biodegradable film fabrication for industrial and application-specific needs. Full article

Background and Clinical Significance: The current paper presents a retrospective case of a 79-year-old female patient admitted to the Dermatology Clinic of Emergency City Hospital in Timisoara, Romania, in January 2022, reporting intense pruritus and burning sensation of the skin exacerbated at night. Case Presentation: The previously mentioned symptoms appeared approximately six months prior, with gradual and continuous progression. Clinical examination revealed widespread hyperkeratosis on diffuse erythematous background across the entire body, accompanied by crusted lesions predominantly on the arms and legs. Laboratory values showed elevated absolute eosinophil count as well as a positive culture swab to Staphylococcus aureus. Two incisional skin biopsies were performed. Microscopic examination in Hematoxylin–Eosin staining revealed thickened stratum corneum with numerous oval-shaped mites with exoskeleton and striations and moderate perivascular lympho-eosinophilic infiltrate in the superficial dermis, leading to a positive diagnosis of crusted scabies. Following etiological treatment, the patient’s evolution was undulating and on the 10th day of hospitalization presented marked dyspnea, followed by cardiorespiratory arrest, leading to the patient’s death. Conclusions: The patient’s outcome could be explained by a Th2-mediated allergic response to Sarcoptes scabiei allergens, in addition to the presence of Staphylococcus aureus on the damaged skin, as dysbiosis can further support an uncontrolled Th2 reaction, leading to anaphylaxis. Full article

The reproductive cycle in domestic dogs involves prolonged phases of hormonal activity, making the endometrial tissue vulnerable to degenerative changes. One common result of these changes is cystic endometrial hyperplasia (CEH), which often leads to pyometra. Another, though rarer, condition is pseudo-placentational endometrial hyperplasia (PEH), characterized by abnormal proliferation of the endometrial glands and stroma, forming placental-like structures without the presence of pregnancy. Case presentation: An 8-year-old female Golden Retriever, healthy and intact, was presented for a routine ultrasound examination to confirm pregnancy after natural breeding 25 days earlier. Two previous pregnancies of this bitch have resulted in small but live litters. The ultrasound examination revealed multiple bilateral thickenings of the uterine horns, with ampullary-shaped enlargements measuring approximately 2.5 × 3.0 cm 25 days after breeding. The endometrium was conspicuously thickened, hypoechogenic, and either homogeneous or with scattered hyperechoic markings and faint striations. The mucosal surface ranged from regular to slightly irregular, and a small amount of hyperechoic condensed fluid was present in the lumen of the horns. No embryos were observed. Based on these findings, two primary diagnoses were considered: PEH or embryonic resorption sites, with a possible segmental uterine inflammation. A diagnosis suggestive of PEH was established through histopathological examination of the uterus after ovariohysterectomy, supported by consistent ultrasound findings that showed no progression or changes over time. Full article

A rare polygonal gold assemblage from the Bodaibo mining district (Russia) was analyzed in this study. It resembles cubic native gold from the same area described as a gold pseudomorph after pyrite. The polygonal assemblage differs from these cubic gold samples by the absence of striations, its stepped morphology, and the presence of euhedral pyrite. It was analyzed with non-destructive techniques (SEM, VSI, and X-ray CT) in order to preserve the integrity of this exceptional sample. The experimental data allowed us to understand how this rare sample could be formed. A formation of secondary deposits, i.e., eluvial placers, is compatible with the mobilization and precipitation of gold by surface effects on primary pyrite, as well as oxidation episodes producing iron oxides/hydroxides. The redox condition in the geological environment caused the pyrite dissolution and release of gold in its structure, leading to the formation of a thin layer of gold on pyrite by epitaxy rather than pseudomorphism. Full article

Additive manufacturing (AM) refers to advanced technologies for building 3D objects by adding material layer upon layer using either electron beam melting (EBM) or selective laser melting. AM allows us to produce lighter and more complex parts. However, various defects are created during the AM process, which severely affect fatigue behavior. In the current research, the effects of the anisotropic microstructure in the in-plane and out-of-plane orientations and defects on the fatigue crack propagation rate (FCPR) and crack path were studied. A resonance machine was used to determine the fatigue crack propagation rate (da/dN vs. ΔK) from the near-threshold up to the final fracture, accompanied by in situ Acoustic Emission (AE) monitoring. Micro-Computerized Tomography (µCT) enabled us to characterize surface and microstructural defects. Metallography was used to determine the microstructure vs. orientations and fractography to classify the fatigue fracture propagation modes. Calculations of the local stress distribution were performed to determine the interactions of the cracks with the defects. In the out-of-plane direction, the material exhibited high fatigue fracture toughness accompanied by a slightly lower fatigue crack propagation rate as compared to in-plane orientations. The near-threshold stress intensity factor was slightly higher in the out-of-plane orientation as compared to that in the in-plane one, accompanied by a lower exponent of the Paris law regime. The threshold decreased with an increasing load ratio as expected for both orientations. The crack propagation direction that crosses the elongated grains plays an important role in increasing fatigue resistance in the out-of-plane direction. In the in-plane directions, the crack propagates parallel to the grain boundary, interacts with more defects and exhibits more brittle striations on the fracture surface, resulting in lower fatigue resistance. Full article

The pine leafhopper genus Pinopona Viraktamath & Sohi was previously classified within the tribe Grypotini. In a recognized classification system, it has been categorized as the subtribe Grypotina of the tribe Koebeliini within Deltocephalinae, based on morphological characteristics such as a crown exhibiting few transverse fine striations along the anterior margin; short antennae measuring less than 1.5 times the head length but not extending to half or more of body length; ocelli positioned below the anterior margin of the crown and not visible from above, with a considerable distance from the eyes; and an anteclypeus that is narrow and tapered beyond the anterior margin of gena, alongside metatarsomere I presenting platellae on the plantar surface. Two new species, Pinopona gongshanensis and Pinopona daliensis spp. nov., are described herein from Yunnan Province and illustrated accordingly. This study also provides a checklist and key for all species within this genus. Full article

This study assessed the possible pharmacological effects of Chlorella vulgaris (Cg), Spirulina platensis (St), and silymarin (Sl) against thioacetamide (TA)-induced cardiotoxicity in rats, with a focus on their antioxidant, cardioprotective, and anti-inflammatory properties. The following is the random grouping of sixty male rats into six groups of ten animals each: the control (negative control), TA-intoxicated group (positive control; 300 mg/kg body weight (BW)), Sl + TA group (100 mg Sl/kg BW + TA), St + TA group (400 mg St/kg BW + TA), Cg + TA (400 mg Cg/kg BW + TA), and St + Cg + TA group (400 St + 400 Cg mg/kg BW + TA) were all administered for 30 days. At the start of the study, groups 2 through 6 were administered TA intraperitoneally at a dosage of 300 mg/kg BW for two consecutive days, with a 24 h gap between each dose, to induce cardiac damage. Blood samples were obtained to measure hematological parameters and perform biochemical assays, including lipid profiles and cardiac enzymes. For histopathology and immunohistochemistry determination, tissue samples were acquired. The current findings showed that TA injection caused hematological alterations and cardiac injury, as evidenced by greater serum levels of troponin I, creatine kinase-MB, and total creatine kinase (p < 0.05), as well as significantly elevated serum malondialdehyde and decreased serum total antioxidant capacity (p < 0.05) concentrations. Moreover, an increase in blood low-density lipoprotein and total cholesterol concentration (p < 0.05) was recorded in the TA group. There were alterations in the heart tissue’s histological structure of the TA group compared to the control ones. These alterations were characterized by vacuolar degeneration of myocytes, loss of cross striation, coagulative necrosis, and fibrosis of interstitial tissue, which was ameliorated by the supplementation of SI, St, and Cg. The TA-intoxicated group showed weak expression of B-cell lymphoma protein 2 (p < 0.05) and strong immunoreactivity of tumor necrosis factor-α and B-cell lymphoma protein 2-associated X (p < 0.05). However, the groups receiving Sl, St, and Cg experienced the opposite. The administration of Sl, St, Cg, and St + Cg along with TA significantly improved and restored (p < 0.05) erythrogram indices, including RBCs, hemoglobin, total leukocytic count, lymphocytes, and monocyte, to the normal control values. The administration of Sl, St, and Cg alleviated the cardiotoxicity caused by TA via reducing oxidative stress, inflammatory markers, and apoptosis in heart tissue. In summary, the current findings suggest that the treatment with Sl, St, and Cg was beneficial in ameliorating and reducing the cardiotoxicity induced by TA in rats. Full article