Search Results (65)

Aluminum alloy, due to its low melting point and high thermal conductivity, deforms and contracts significantly during welding. To mitigate this and achieve full penetration in a single pass, this study uses GTAW (Gas Tungsten Arc Welding) additive manufacturing and optimizes welding groove parameters via the Box-Behnken Response Surface Methodology. The focus is on improving tensile strength and penetration depth by analyzing the effects of groove angle, root face width, and root gap. The results show that groove angle most significantly affects tensile strength and penetration depth. Hardness profiles exhibit a W-shape, with base material hardness decreasing and weld zone hardness increasing as groove angle rises. Root face width reduces hardness fluctuation in the weld zone, and an appropriate root gap compensates for thermal expansion, enhancing joint performance. The interaction between root face width and root gap most impacts tensile strength, while groove angle and root face width interaction most affects penetration depth. The optimal welding parameters for 7xxx aluminum alloy GTAW are a groove angle of 70.8°, root face width of 1.38 mm, and root gap of 0 mm. This results in a tensile strength of 297.95 MPa and penetration depth of 5 mm, a 90.38% increase in tensile strength compared to the RSM experimental worst group. Microstructural analysis reveals the presence of β-Mg₂Si and η-MgZn₂ strengthening phases, which contribute to the material’s enhanced mechanical properties. Fracture surface examination exhibits characteristic ductile fracture features, including dimples and shear lips, confirming the material’s high ductility. The coexistence of these strengthening phases and ductile fracture behavior indicates excellent overall mechanical performance, balancing strength and plasticity. Full article

Continental rifting is the process by which land masses separate and create new ocean basins. The emplacement of large igneous provinces (LIPs) is thought to have played a key role in (super) continental rifting; however, this relationship remains controversial due to the lack of a clearly established mechanism linking LIP emplacement to continental fragmentation. Here, we show that plume flow links LIP magmatism to continental rifting quantitatively. Our findings are further supported by the sedimentary record, as well as by the mineralogy and petrology of the rocks. This study analyzes the early Cretaceous separation of West Gondwana into South America and Africa. Prior to rifting, Jurassic hiatuses in the stratigraphic record of continental sediments from both continents indicate plume ascent and the resulting dynamic topography. Cretaceous mafic dyke swarms and sill intrusions are products of major magmatic events that coincided with continental rifting, leading to the formation of large igneous provinces in South America and Africa, including the Central Atlantic Magmatic Province, Equatorial Magmatic Province, Paraná–Etendeka, and Karoo. It has been suggested that dyke intrusions may weaken the lithosphere by reducing its mechanical strength, creating structural weaknesses that localize extensional deformation and facilitate rift initiation. The sedimentary analysis and petrological evidence from flood basalt magmas indicate that plumes may have migrated from the depths toward the surface during the Jurassic and erupted during the Cretaceous. It is thought that the resulting fast plume flow, induced by one or more mantle plumes, generated a dynamic force that, in combination with lithospheric weakening from dyke intrusion, eventually rifted the lithosphere of West Gondwana. Full article

Metal inert gas (MIG) brazing was used to join galvanized thin sheets with thicknesses in the range of 0.8 to 2 mm in a lap joint configuration using CuAl₈ wire as filler. The process was used to manufacture built-up cold-formed steel beams composed of corrugated steel webs and flanges made from thin-walled cold-formed steel lipped channel profiles. The effect of heat input and sheet thickness on joint properties, such as macro- and microstructure, wettability, and mechanical characteristics such as microhardness and tensile strength were investigated. The bead geometry was assessed by studying the wettability of the filler material. The microstructure was investigated by digital and scanning electron microscopy, and the composition in the heat-affected zone (HAZ), interface, and bead was determined by energy dispersive spectroscopy. Formation of Fe–Al intermetallics was observed in the bead at the bead–base material interface. Some pores were noticed that formed due to the evaporation of the zinc coating. The bead shape and mechanical properties were found to be the best when 1.2 and 2 mm sheets were brazed using a heat input of 121.4 J/mm. This suggests that not only the heat input but also the thickness of the sheet metal play a crucial role in the production of MIG brazed joints. Full article

Background: Hypokinetic dysarthria is a speech disorder observed in almost 90% of PD patients that can appear at any stage of the disease, usually worsening as the disease progresses. Today, speech therapy intervention in PD is seen as a possible therapeutic option to alleviate and slow down the progression of symptoms. This study aims to investigate the validity of traditional speech therapy in dysarthria with the aim of improving the quality of life of PD patients, by comparing subjective clinical assessment with objective instrumental measures (IOPI and voice analysis). Methods: This is an observational study of 30 patients with hypokinetic dysarthria due to PD. The patients underwent speech therapy treatment with a frequency of three times per week for 12 consecutive weeks. Patients were evaluated at the time of enrollment (T0), at the start of treatment (T1), and at the end of the same (T2). Six months after the end of treatment (T3), a follow-up was performed based on disability and phonatory evaluation. Results: This study showed significant improvements (<0.001) from the start (T1) to the end of treatment (T2), with increases in the Barthel Index score, Robertson Dysarthria Profile, and IOPI measurements for tongue and lip strength, along with enhanced phonometer scores and tongue endurance. Correlations highlighted that tongue endurance decreased with age, CIRS, and MDS-UPDRS, while showing a positive association with MoCA scores. Conclusions: Significant improvements were observed in tongue and lip strength, phonatory duration, intensity, and vocal quality between pre- (T1) and post-treatment (T2). This study underscores the importance of early and continuous speech therapy treatment for comprehensive speech function enhancement. Full article

Understanding others correctly is of great importance for maintaining effective communication. Factors such as hearing difficulties or environmental noise can disrupt this process. Lip reading offers an effective solution to these challenges. With the growing success of deep learning architectures, research on lip reading has gained momentum. The aim of this study is to create a lip reading dataset for Turkish digit recognition and to conduct predictive analyses. The dataset has divided into two subsets: the face region and the lip region. CNN, LSTM, and 3DCNN-based models, including C3D, I3D, and 3DCNN+BiLSTM, were used. While LSTM models are effective in processing temporal data, 3DCNN-based models, which can process both spatial and temporal information, achieved higher accuracy in this study. Experimental results showed that the dataset containing only the lip region performed better; accuracy rates for CNN, LSTM, C3D, and I3D on the lip region were 67.12%, 75.53%, 86.32%, and 93.24%, respectively. The 3DCNN-based models achieved higher accuracy due to their ability to process spatio-temporal data. Furthermore, an additional 1.23% improvement was achieved through ensemble learning, with the best result reaching 94.53% accuracy. Ensemble learning, by combining the strengths of different models, provided a meaningful improvement in overall performance. These results demonstrate that 3DCNN architectures and ensemble learning methods yield high success in addressing the problem of lip reading in the Turkish language. While our study focuses on Turkish digit recognition, the proposed methods have the potential to be successful in other languages or broader lip reading applications. Full article

This study conducted experiments to investigate the flexural behavior of steel–concrete composite beams with U-shaped sections, utilizing cold-formed lipped channels as web components. To enhance both flexural and shear performance, trapezoidal plates were added to the lower sides of the composite beams. A total of ten specimens were fabricated, with variables defined according to the following criteria: presence of bottom tension reinforcement and bottom studs, thickness of the trapezoidal side plates (6 mm and 8 mm), and the welding method. Four-point bending tests were conducted, and all specimens exhibited typical flexural failure at the ultimate state. Specimens with bottom tension reinforcement, specifically those in the H5-T6 and H5-T8 series, demonstrated increases in ultimate load of 28.8% and 33.5%, respectively, compared to specimens without tension reinforcement. The use of lipped channels enabled full composite action between the concrete and the steel web components, eliminating the need for stud anchors. Additionally, it was confirmed that the plastic neutral axis, reflecting the material test strengths, was located within the concrete slab as intended. This study also compared the design flexural strengths, calculated using the yield stress distribution method from structural steel design standards such as AISC 360 and KDS 14, with the experimental flexural strengths. The comparison was used to evaluate the applicability of current design standards. Full article

Most previous studies on orofacial muscle strength have focused on older adults with conditions associated with sensorimotor deficits, such as stroke. However, the modifiable oral health factors that directly impact orofacial muscle strength and swallowing ability in healthy older adults remain unexplored. This pilot study explored the potential factors associated with orofacial muscle strength, particularly oral health conditions, in 70 healthy adults aged ≥65 years living independently without any diseases that cause dysphagia or sensorimotor deficits. The Iowa Oral Performance Instrument (IOPI) was used to assess orofacial muscle strength (tongue elevation, and cheek and lip compression). Statistical analyses were conducted using an independent t-test, one-way ANOVA, and multivariate linear regression. In the final regression models after adjustment, older age and fewer remaining teeth were significantly associated with reduced tongue and cheek strengths (p < 0.05). Socio-demographic factors, such as age, and oral health conditions, such as discomfort in pronunciation or mastication due to oral problems, poor self-rated oral health, and reduced salivary flow, were associated with tongue, cheek, and lip muscle strengths (p < 0.05). Early active oral health interventions can help prevent a decline in orofacial muscle strength in healthy older adults. Full article

Background/Objectives: Health management in workers in the taxi industry is particularly challenging due to irregular working hours and the need to prevent fatal accidents. In addition, drivers in Japan are aging, and the early prevention of age-related deterioration in oral health is an increasingly important issue. The aim of this cross-sectional study was to investigate the relationships between oral diadochokinesis (OD), tongue pressure, and lip-seal strength in Japanese male taxi workers. Methods: Measurements of tongue pressure and lip-seal strength were performed by dentists using specialized equipment. OD was measured using the number of consecutive “Pa”, “Ta”, and “Ka” vocalizations that could be produced in 5 s. We performed multiple regression analysis to examine the effects of lip-seal strength and tongue pressure on OD. Results: The study included 437 participants, excluding 17 who could not complete all oral cavity measurements. Tongue pressure showed a significant positive correlation with “Pa”, “Ta”, and “Ka” (correlation coefficients: 0.527–0.680). Lip-seal strength was not significantly correlated with OD. Tongue pressure showed a significant positive correlation with “Pa”, “Ta”, and “Ka”. In the results of multiple regression analyses without the elderly participants, tongue pressure was associated with “Pa” (β[95% confidence interval]: 0.574[0.304, 0.843]), “Ta” (0.436[0.231, 0.640]), and “Ka” (0.424[0.210, 0.639]), and lip-seal strength was associated with “Pa” (0.128[0.032, 0.224]) and “Ka” (0.083[0.006, 0.160]). Conclusions: OD may be associated with lip-seal strength and tongue pressure even without including elderly workers. Regardless of age, maintaining good OD may help maintain lip-seal strength and tongue pressure, which may play a role in reducing the risk of age-related oral disorders. Full article

To enhance the efficiency of irrigation water utilisation, China is progressively converting irrigation ditches into pipelines. The water distribution outlets in irrigation zones are predominantly right-angled, and there are typically occurrences of erosion, sedimentation, and structural deterioration in the surrounding areas. This article employs a synthesis of indoor physical model experiments and theoretical analysis to examine the distribution of channel flow velocity and variations in water surface profile, pipeline flow rate, diversion ratio, circulation intensity, and turbulence energy across different relative water depths. The experimental results indicate that the water surface adjacent to the main canal wall demonstrates a pattern of initial decline, followed by an increase and subsequently another decline; furthermore, as the water level in the main channel rises, the magnitude of this fluctuation progressively diminishes. In some sections of the canal, the water surface elevation progressively increases, albeit with minimal amplitude. With a constant relative water depth, an increase in main channel flow results in a corresponding increase in pipeline flow; however, the diversion ratio is inversely related to the main channel flow. Conversely, when the main channel flow rate is constant, the diversion ratio increases as relative water depth rises. The vertical flow velocity near the water diversion outlet has a negative value, signifying the existence of a backflow zone, while the horizontal flow velocity varies considerably, facilitating the formation of circulation and resulting in localised deposition and erosion. The water flow near the pipe inlet downstream of the lower lip of 0.5 times the pipe diameter is impacted by the return zone, which has a higher turbulence energy and circulation strength and is more susceptible to siltation. The turbulence energy of the water flow is higher in the range of 0.5 times the pipe diameter upstream and downstream of the pipe inlet. This research is highly significant in facilitating the conversion of irrigation channels into pipelines. Full article

This study introduces a novel approach for the diagnosis of Cleft Lip and/or Palate (CL/P) by integrating Vision Transformers (ViTs) and Siamese Neural Networks. Our study is the first to employ this integration specifically for CL/P classification, leveraging the strengths of both models to handle complex, multimodal data and few-shot learning scenarios. Unlike previous studies that rely on single-modality data or traditional machine learning models, we uniquely fuse anatomical data from ultrasound images with functional data from speech spectrograms. This multimodal approach captures both structural and acoustic features critical for accurate CL/P classification. Employing Siamese Neural Networks enables effective learning from a small number of labeled examples, enhancing the model’s generalization capabilities in medical imaging contexts where data scarcity is a significant challenge. The models were tested on the UltraSuite CLEFT dataset, which includes ultrasound video sequences and synchronized speech data, across three cleft types: Bilateral, Unilateral, and Palate-only clefts. The two-stage model demonstrated superior performance in classification accuracy (82.76%), F1-score (80.00–86.00%), precision, and recall, particularly distinguishing Bilateral and Unilateral Cleft Lip and Palate with high efficacy. This research underscores the significant potential of advanced AI techniques in medical diagnostics, offering valuable insights into their application for improving clinical outcomes in patients with CL/P. Full article

The verification of a column made from a lipped cold-formed channel section, subjected to pure axial compression relative to the gross cross-section, often results in a combined verification of bending and compression due to the appearance of a shift of the centroid of its effective cross-section. Following Eurocode 3 rules, this requires the determination of two distinct effective cross-sections and various interaction factors. This paper, based on an analytic approach, offers a modification to the actual buckling curve, based on Ayrton–Perry formulation, to include the second-order effects raised by the eventual shift of the effective centroid due to local buckling of the compressed web plate. This eliminates the need to use an interaction formula. The modified buckling curve is verified based on a GMNIA analysis performed on a numerical parametric model, which was previously validated by laboratory tests. In addition, the results are compared with strength results provided by appropriate Eurocode 3 formulas and AISI Direct Strength Method for global-local interaction and with classic experimental results. Full article

Background/Objectives: An association between oral function and physical fitness, including walking capacity, has been reported. However, the association between masticatory behaviors and walking ability—both of which represent patterns of movement in daily life—has not been clarified. This study aimed to investigate the association between masticatory behaviors, oral function, and walking capacity in older people. Methods: One hundred community-dwelling older people (31 men, 69 women, mean age 75.7 ± 6.3 years) were selected to participate in this study. Age, sex, masticatory behaviors, oral functions (tongue pressure, tongue–lips motor function, occlusal force, and masticatory performance), and walking capacity were assessed. Masticatory behaviors were assessed during the consumption of one rice ball (100 g) using a wearable chewing counter, and the number of chews, chewing rate, the number of chews per bite, and meal time were recorded. Walking capacity was assessed using the timed up and go test (TUG). Spearman’s rank correlation coefficients were calculated to assess the strength and direction of the association. Results: Moderate negative correlations were observed between TUG time and tongue pressure and between TUG time and tongue–lips motor function (/ta/ and /ka/) (rs = −0.33, −0.21, −0.28, respectively). In addition, moderate negative correlations between TUG time and chewing rate (rs = −0.22) and between TUG time and meal time (rs = 0.33) were observed, suggesting that lower walking capacity was associated with slower chewing rate and longer meal times. Conclusions: In community-dwelling older people, declines in mastication speed and dexterity and tongue strength are associated with lower walking capacity. Full article

With the startup of the aero-engine, the ground vortex is formed between the ground and the engine intake. The ground vortex leads to total pressure and swirl distortion, which reduces the performance of the engine. The inhalation of the dust and debris through a ground vortex can erode the fan blade, block the seals and degrade turbine cooling performance. As the diameter of the modern fan blade becomes larger, the clearance between the intake lip and the ground surface is smaller, which enhances the strength of the ground vortex. Though considerable numerical studies have been conducted with the predictions of the ground vortex, it is noted that the accurate simulation of the ground vortex is still a tough task. This paper presents authors’ simulation work of the ground vortex into an intake model with different crosswind speeds. This paper tackles the challenge with a parametric study to provide useful guidelines on how to obtain a good match with the experimental data. The influence of the mesh density, performance of different turbulence models and how the boundary layer thickness affects the prediction results are conducted and analysed. The detailed structure of the flow field with ground vortex is presented, which can shed light on the experimental observations. A number of suggestions are presented that can pave the road to the accurate flow field simulations with strong vorticities. Full article

Purpose: Facial paralysis results from congenital or acquired facial nerve damage, leading to significant cosmetic and functional deficits. Surgical resection of parotid and midface tumors can cause facial paralysis, necessitating effective treatment strategies. This review addresses the challenge of restoring movement and function in late-stage facial paralysis, focusing on dynamic repair techniques involving nerve and muscle transplantation. Methods: The review encompasses studies on dynamic repair surgery for late facial paralysis, including techniques such as local muscle flap with pedicle transfer, vascularized nerve flap with pedicle transfer, and multiple muscle flap procedures. A systematic literature search was conducted using PubMed, Web of Science, and Google Scholar, covering studies from 2000 to 2024. Keywords included “dynamic repair”, “late-stage facial paralysis”, “nerve and muscle transplantation”, “muscle flap”, and “tendon transposition”. Included were clinical studies, systematic reviews, and meta-analyses reporting surgical outcomes. Exclusion criteria included studies with insufficient data and non-peer-reviewed articles. Results: Dynamic repair techniques involving nerve and muscle transplantation are essential for treating late-stage facial paralysis. Each surgical method has strengths and limitations. The masseter muscle flap demonstrates high success rates, although it can cause horizontal tension and jaw contour issues. The temporalis muscle flap is effective for smile restoration but may lead to temporal concavity. The gracilis muscle flap is widely used, especially with dual nerve innervation, showing high success in spontaneous smiles but requiring a longer recovery period. The latissimus dorsi flap is effective but can cause edema and shoulder issues. The serratus anterior free flap offers flexibility with precise vector positioning but may not achieve adequate lip elevation and can cause cheek swelling. Combined multi-flap surgeries provide more natural facial expressions but increase surgical complexity and require advanced microsurgical skills. Conclusions: Dual nerve innervation shows promise for restoring spontaneous smiles. One-stage surgery offers faster recovery and reduced financial burden. Comprehensive patient evaluation is crucial to select the most suitable surgical method. Dynamic repair techniques involving nerve and muscle transplantation provide effective solutions for restoring function and aesthetics in late-stage facial paralysis. Future research should focus on long-term outcomes, patient satisfaction, and standardizing surgical protocols to optimize treatment strategies. Full article

Owing to the paucity of research on synchronous mafic rocks in the Tarim Basin, the late Paleozoic–early Mesozoic tectonic development of this region is not well defined. The Halaqi region is situated on Tarim’s northwest edge, and numerous mafic dikes can be found cross-cutting the Permian strata. The whole-rock geochemistry, zircon U–Pb age, and Sr–Nd isotopic signature of these mafic rocks have never been reported before, and this contribution can offer geochronological and petrogenetic investigations that provide fresh insight into the geodynamic development of the area. Major oxide contents in the Halaqi mafic rocks vary, including SiO₂ (45.74–50.31 wt.%), Al₂O₃ (13.28–14.8 wt.%), FeO^T (16.48–19.19 wt.%), MgO (7.58–10.32 wt.%), CaO (7.19–12.39 wt.%), Na₂O (2.97–4.50 wt.%), K₂O (0.24–0.63 wt.%), TiO₂ (1.11–1.29 wt.%), MnO (0.14–0.16 wt.%), and P₂O₅ (0.13–0.17 wt.%). The mafic rocks are enriched in high-field-strength elements (e.g., Zr and Hf) and large-ion lithophile elements (e.g., Sr, Th, and U) but depleted in Nb, Ta, and P. The total REEs in the rocks are lower (ΣREE = 72.80–86.85 ppm), and HREEs are somewhat depleted in comparison to LREEs, with positive Eu anomalies (Eu/Eu* = 1.05–1.17) but weak negative Ce anomalies (Ce/Ce* = 0.91–0.93). Zircon U–Pb ages of 201–247 Ma were obtained from a total of 18 magmatic zircon grains found in the mafic rocks that were studied. These results point to a middle-to-late Triassic emplacement. The mafic dikes exhibit somewhat enriched Nd isotopic compositions (ε_Nd(t) = –1.6~–0.2) and an older Nd model age (T_DM = 1.24–1.37 Ga). The Halaqi middle–late Triassic mafic dikes are thought to have originated from the same tectonic background as the Permian Tarim Large Igneous Province, along with similar geochemical and isotopic compositions. This suggests that they are all products of the interaction between asthenospheric and lithospheric mantles in an intraplate extensional environment. Research indicates that the Triassic mafic magmatism in northwest Tarim could be the product of the continuous thermal pulse of the Tarim mantle plume and be a part of the Tarim LIP. Full article