Search Results (1,050)

Background: Surface chemistry and cleanliness are widely regarded as important factors influencing the host response to titanium dental implants. Despite advances in manufacturing and sterilization, trace residues may persist at the nanoscale even in commercially sterile devices. This study provides a preliminary evaluation of premium-grade titanium dental implants using time-of-flight secondary ion mass spectrometry (ToF-SIMS) to assess surface chemical uniformity and trace contaminant distribution. Method: Two commercially available titanium implants from Schütz Dental were analyzed under static and dynamic ToF-SIMS modes using Bi₃⁺ and Cs⁺ ion beams. Both positive and negative ion spectra were collected to identify elemental and molecular species. Chemical mapping and depth profiling were performed to evaluate contaminant distribution and surface depth composition. Results: In the two implants analyzed, the surfaces were dominated by TiO⁺ and TiO₂⁺ species, consistent with a native titanium oxide layer. In both analyzed implants, localized contaminants—including fluorine, chlorine, sulfur, CN groups, and organic residues—were detected within the outermost ~0.1 µm. These signals showed heterogeneous distribution along the thread-related regions within the analyzed ROIs, compatible with residues originating from machining, surface treatments, packaging, and/or sterilization steps. Conclusions: The present data support only the descriptive finding that trace contaminants were detected on the two analyzed implants. ToF-SIMS enabled nanoscale chemical mapping and depth profiling of these residues, supporting the feasibility of this approach for trace-level surface auditing and hypothesis generation. Any biological/clinical implications remain speculative and require dedicated in vitro/in vivo validation on larger sample sets. Full article

The high rate of bike commuting around the globe has greatly transformed the mode of transportation in cities, but the high speeds of motorized cycling have contributed to a high rate of serious road trauma. Although conventional helmets offer necessary passive structural protection, they do not consider the most important aspect of the emergency response, which is the Golden Hour the time frame during which medical intervention can have the most significant impact. This paper is a development and validation of an autonomous, low-cost smart helmet architecture that is programmed to operate in real-time to detect accidents and autonomously inform the operator of accidents. The system is built up of an ESP32 microcontroller with a multi-modal sensor package, which comprises an inertial measurement unit (IMU), force-impact sensors, and MQ-3 alcohol sensors to conduct proactive safety screening. To overcome the single threshold limitation of unreliable systems, a time-windowed sensor-fusion algorithm was applied in order to distinguish between normal riding dynamics and bona fide collisions. This reasoning involves concurrent cues of high-G inertial rotations and physical impacting features over a time window of 500 ms to reduce spurious activations. The architecture of the system is completely self-sufficient and employs an in-built GPS-GSM module to send the geographical location through SMS without the need to have a smartphone connection. The prototype was also put through 150 experimental tests, with some conducted in laboratories, and real-world running tests in diverse terrains. The findings reveal an accuracy in detection of 93.7, a false positive rate (FPR) of 2.6 and a mean emergency alert latency of 2.8 s. In addition, it was found that structural integrity was confirmed at ECE 22.05 impact conditions using Finite Element Analysis (FEA), with a safety factor of 1.38. These quantitative results mean that the proposed system is an effective way to address a cultural shift between passive structural protection and active rescue intervention as a statistical and computationally efficient safety measure of modern micro-mobility. Full article

A mix of internal and external factors affect farmers’ recycling practices with regarding pesticide packaging waste. However, most of the research that has been done so far has concentrated on the individual effects of these elements rather than providing a clear explanation of the intricate mechanisms by which a variety of internal and environmental factors work together to drive recycling behavior. This study builds an integrated “internal–external” factor analysis framework based on Lewin’s Behavior Model, integrating Organizational Support Theory and the Theory of Planned Behavior to close this gap. We examine the many configurational pathways influencing farmers’ willingness to recycle pesticide packaging debris using fuzzy-set Qualitative Comparative Analysis (fsQCA). The results showed that there are four different configurational approaches that lead to a high readiness to recycle: the information–norm interaction-driven path, the capability–belief-driven path, the norm–emotion endogenous-driven path, and the psychology-driven dominant path. Farmers’ attitudes toward recycling were found to be a key component in all four routes, indicating that it is essential to attaining high recycling willingness. The findings of this study offered policy insights for encouraging recycling behavior and assisted in identifying the intricate causal processes of multi-factor synergy impacting farmers’ propensity to recycle pesticide packaging trash. Full article

Bi-doped low-silver Sn-Ag-Cu solders are increasingly gaining attention in advanced electronic packaging due to their cost-effectiveness and enhanced mechanical properties. However, the thermo-mechanical reliability mechanisms of such modified solders, particularly Sn-0.3Ag-0.7Cu-3Bi (SAC0307-3Bi) within Ball Grid Array (BGA) assemblies, remain insufficiently understood. To address this gap, this research proposes a comprehensive assessment framework integrating constitutive parameter calibration with finite element analysis (FEA) to accurately characterize the mechanical behavior and fatigue durability of SAC0307-3Bi solder joints under cyclic thermal loads. The Anand viscoplastic parameters were first calibrated via the Norton creep law and virtual tensile tests. Subsequently, a 3D quarter-symmetry model was constructed to replicate thermal cycling conditions between 25 °C and 125 °C. Simulation data reveal a strong correlation between stress concentration and the Distance to Neutral Point (DNP), pinpointing the chip-side interface of the corner joint as the critical failure site. Moreover, creep strain was observed to accrue in a “step-wise” pattern, predominantly during the heating and cooling ramps, reflecting distinct temperature sensitivity. Utilizing the Syed model, the fatigue life was estimated at approximately 2239 cycles. These insights serve as a crucial benchmark for designing robust packages using Bi-doped, low-silver lead-free solders. Full article

This study investigates the thermodynamic and experimental aspects of producing a chromium–manganese ligature under high-temperature smelting conditions using low-grade iron–manganese ore and ferrosilicochrome (FeSiCr) dust as both a reducing agent and a chromium source. Thermodynamic modeling of the multicomponent Fe–Cr–Mn–Si–Al–Ca–Mg–O system was carried out using the HSC Chemistry 10 and FactSage 8.4 software packages to substantiate the temperature regime, reducing agent consumption, and conditions for the formation of a stable metal–slag system. The calculations indicated that efficient reduction of manganese oxides and formation of the metallic phase are achieved at a smelting temperature of 1600 °C with a reducing agent consumption of approximately 50 kg. Experimental smelting trials conducted in a laboratory Tammann furnace under the calculated parameters confirmed the validity of the thermodynamic predictions and demonstrated the feasibility of obtaining a concentrated chromium–manganese ligature. The resulting metallic product exhibited a high total content of alloying elements and had the following chemical composition (wt.%): Fe 35.41, Cr 41.10, Mn 8.15, and Si 4.31. SEM–EDS microstructural analysis revealed a uniform distribution of chromium and manganese within the metallic matrix, indicating stable reduction behavior and favorable melt crystallization conditions. The obtained results demonstrate the effectiveness of an integrated thermodynamic–experimental approach for producing chromium–manganese ligatures from low-grade mineral raw materials and industrial by-products and confirm the potential applicability of the proposed process for complex steel alloying. Full article

The present study extends the previous work which was concerned with the identification of damage in GFRP composite plates by damage detection algorithms such as the Normalized Curvature Damage Factor (NCDF), Strain Energy Difference (SED), and Damage Index (DI), using a novel damage (crack) modeling technique called the ‘Node-Releasing Technique’ (NRT) in Finite Element Analysis (FEA) for modeling and detecting perpendicular and slant partial-depth cracks in GFRP composite beams. This study explores the sensitivity of the damage modeling technique NRT in damage detection for composite beams using the NCDF algorithm, since it was concluded in the previous work that the NCDF performs better compared to the other methods when detecting both perpendicular and slant partial-depth cracks. This study also examines the variations in the Frequency Response Function (FRF) as another novel tool for identifying even small-scale damage. Most prior research in this domain has focused on variations in natural frequency, displacement mode shape, and damping as indicators for detecting and localizing structural damage through various experimental, theoretical, and computational approaches. However, these conventional parameters often lack the sensitivity required to detect small-scale damage and, still, there exists a gap in the use of the node-releasing technique in FEA to model the partial-depth perpendicular and slant crack damage in laminated composite structures, such as beam-like structures. To fill this gap, the present study attempts to use Curvature Mode Shapes (CMS)-based NCDF, obtained from numerical modal analysis, and variations in the Frequency Response Function (FRF), obtained through harmonic analysis, as more sensitive indicators for damage detection in laminated composite beams. FEA simulations are performed using the commercial FEA software package ANSYS 2021 R1 to obtain the first five flexural natural frequencies and the corresponding displacement mode shapes of both the intact and damaged composite beams. The curvature mode shapes are obtained from the displacement mode shapes data using the central difference approximation method to compute the NCDF. Simultaneously, GFRP composite beams were fabricated by the hand lay-up method, and Experimental Modal Analysis (EMA) was employed to substantiate the FE model and the validity of the numerical results. By combining both numerical and experimental methods, we proved that NCDF and FRF are reliable tools to determine and locate structural damage, even at a comparatively small scale. In general, the results indicate that NCDF is a stable and practically applicable parameter to locate cracks in laminated composite beams and provide meaningful information to be used as guidelines in applications of vibration-based structural health monitoring. Full article

Contamination of drinking water by potentially toxic elements (PTEs) remains a critical public-health concern in Uganda. This systematic review compiled and harmonized quantitative concentrations (mg/L) for key PTEs, lead (Pb), cadmium (Cd), arsenic (As), chromium (Cr), mercury (Hg), copper (Cu), zinc (Zn), nickel (Ni), cobalt (Co), manganese (Mn), and iron (Fe), across various potable and informal water sources used for drinking, including municipal tap water, boreholes, protected and unprotected springs, wells, rainwater, packaged drinking water, rivers, lakes, and wetlands. A comprehensive search of different databases and key institutional repositories yielded 715 records; after screening and eligibility assessment, 161 studies met the inclusion criteria, and were retained for final synthesis. Reported PTE concentrations frequently exceeded WHO and UNBS drinking water guidelines, with Pb up to 8.2 mg/L, Cd up to 1.4 mg/L, As up to 25.2 mg/L, Cr up to 148 mg/L, Fe up to 67.3 mg/L, and Mn up to 3.75 mg/L, particularly in high-risk zones such as Rwakaiha Wetland, Kasese mining affected catchments, and Kampala’s urban springs and drainage corridors. These hotspots are largely influenced by mining activities, industrial discharges, agricultural runoff, and corrosion of aging water distribution infrastructure, while natural geological conditions contribute to elevated background Fe and Mn in several regions. The review highlights associated health implications, including neurological damage, renal impairment, and cancer risks from chronic exposure, and identifies gaps in regulatory enforcement and routine monitoring. It concludes with practical recommendations, including stricter effluent control, expansion of low-cost adsorption and filtration options at household and community level, and targeted upgrades to water-treatment and distribution systems to promote safe-water access and support Uganda’s progress toward Sustainable Development Goal 6. Full article

With the widespread application of high-power thick-film-substrate light-emitting diode (LED) packages, the performance of high-power LED modules has been continuously improved, making thermal management an increasingly critical issue. To enhance the heat dissipation performance of LED modules, this study investigates the effects of different heat dissipation structures on the temperature field using a finite element-based thermal simulation method, based on the thermal management enhancement characteristics of the LED. A thermal simulation model of the LED was established, and the thermal characteristics and temperature field characterization of its components were analyzed. Our results revealed significant temperature differences at various positions of the LED, particularly near the bottom surface of the heat sink and the contact surface with the LED chips, where the heat flux density exhibited notable variations. Properly adjusting the spacing between LEDs effectively reduced the maximum temperature of the module, with the optimal spacing determined to be approximately 19 mm. To further improve heat dissipation, pin-fin arrays were added to the heat sink, leading to a reduction of 8.79 K in the maximum temperature and 9.67 K in the minimum temperature of the LED module, which significantly enhanced the heat dissipation performance. The optimization measures effectively improved the temperature field characterization of the LED, contributing to enhanced performance and an extended lifespan of the LED module. Full article

In response to the challenge of achieving highly reliable interface fabrication in the fields of microelectronics and micro-electromechanical system (MEMS) packaging, this study harnesses the superior characteristics of solid-state bonding inherent in explosive welding (EXW) technology. This study investigates the precise EXW of milligram-scale metallic foils by employing focused laser energy to control the explosion behavior of liquid energetic materials, thereby generating shockwaves that induce high-velocity oblique collisions between metallic foils and base plates. Laser-focused energy was utilized to regulate energetic materials for conducting precision EXW experiments on Al/Cu couples. The technical feasibility and interfacial quality of this method for fabricating Al/Cu bonding interfaces were systematically evaluated through in situ observation of the dynamic welding process, comprehensive analysis of interfacial microstructures, and numerical simulations. The results reveal distinct Al/Cu elemental diffusion at the bonding interface, confirming the technical viability of the approach. However, an unloading rebound phenomenon is observed at the interface, which is inherently associated with the dynamic impact process, indicating the need for further optimization in the precise control of impact loading. Full article

A simple self-decoupling approach using only a shorting pin is proposed to effectively reduce mutual coupling in multiple-input multiple-output patch antennas. By loading a shorting pin along the polarization direction on one side of the patch antenna, the equivalent inductance of the corresponding source is altered, thereby changing the initial phase of the slot source. This modification, in conjunction with the path effect, creates a mutual coupling null by counteracting the electric fields at the adjacent patch’s feeding position, achieving a reduced mutual coupling level. The simplicity of this decoupling method enables flexibility in practical applications, facilitating adaptation to diverse packaging environments and substrates. Furthermore, the proposed method effectively suppresses mutual coupling between adjacent and non-adjacent elements in multi-element linear arrays, as well as between elements arranged along E-planes and H-planes in planar arrays. To validate the effectiveness of this self-decoupling technique, a two-element decoupled antenna was fabricated and measured. Experimental results demonstrate a decrease in mutual coupling from −22 dB to below −40 dB across the effective frequency range of 4.809 GHz to 4.984 GHz. Full article

This study addresses the critical packaging requirements of implantable pressure sensors concerning measurement accuracy and environmental stability. We propose a solid/liquid composite packaging technique based on Parylene-C and silicone oil. Utilizing liquid silicone oil as an intermediate medium, this method effectively decouples solid/solid interface shear forces, thereby mitigating measurement errors caused by mechanical coupling. Furthermore, the superior hydrophobic properties of silicone oil and its defect-filling capability are employed to slow the infiltration rate of water molecules at the interface, ensuring long-term stability. The influence of the solid/liquid composite layer on the mechanical properties of the sensor’s sensitive element was analyzed through finite element simulation. The experimental results demonstrate the efficacy of this approach: after adding a liquid silicone oil layer between the Parylene coating and the sensitive element, the sensor’s accuracy improved to 0.5 mmHg within the pressure range encountered in clinical human applications. In simulated bodily fluids, it demonstrated exceptional long-term stability, with drift values consistently below 2 mmHg over a 30-day period. This research provides a feasible and straightforward solution for the packaging design of high-performance implantable pressure sensors. Full article

In the context of Poland’s commitments under the European Union’s climate policy, including the European Green Deal and the Fit for 55 package, as well as the decision to ban imports of hard coal from Russia and Belarus, ensuring the stability of the domestic market for energy commodities is becoming a key challenge. The response to these needs is the Coal Platform concept developed by the KOMAG Institute of Mining Technology (KOMAG), which aims to integrate data on hard coal resources, production, and demand. The most important problem is not the just-in-time (JIT) strategy itself, but the lack of accurate, up-to-date data and the high technological and organizational inertia on the production side. The JIT strategy assumes an ability to predict future demand well in advance, which requires advanced analytical tools. Therefore, the Coal Platform project analyses the use of artificial intelligence algorithms to forecast demand and adjust production to actual market needs. The developed mathematical model (2024–2030) takes into account 12 variables, and the tested forecasting methods (including ARX and FLNN) exhibit high accuracy, which together make it possible to reduce overproduction, imports, and CO₂ emissions, supporting the country’s responsible energy transition. This article describes approaches to issues related to the development of the Coal Platform and, above all, describes the concept, preliminary architecture, and data model. As an additional element, a mathematical model and preliminary results of research on forecasting methods in the context of historical data on hard coal production and consumption are presented. The core innovation lies in integrating the just-in-time (JIT) philosophy with AI-driven forecasting and scenario-based planning within a cloud-ready Coal Platform architecture, enabling dynamic resource management and compliance with decarbonization targets. Full article

As a packaging material, molded pulp has experienced sustained growth in demand because of its high recyclability and biodegradability. However, refined structural modeling of their behavior during transportation remains limited. This study established finite element representations of molded pulp packaging structural cells and developed a spring–mass dynamic model that incorporates the parameters of the packaged product. The proposed model can predict the combined modal characteristics of molded pulp packaging and the protected item while significantly reducing the computational requirements compared with traditional FEM (finite element method) analyses. Experimental validation shows that the prediction error of the first order modal frequency is approximately 6%, which meets the actual needs. The model provides a foundation for the subsequent optimization of molded pulp structures under road transport conditions. Full article

Introduction: Patients with colorectal cancer who undergo ileostomy surgery confront multifaceted challenges that significantly impact their daily lives and cause symptoms of anxiety and depression. The aim of this study was to explore the anxiety and depression experienced by colorectal cancer patients undergoing ileostomy with three assessments. Materials and Methods: This longitudinal study included 96 patients with newly diagnosed colorectal cancer who underwent scheduled ileostomy surgery at two public hospitals in Attica. The Hospital Anxiety and Depression Scale (HADs) was used, which included patients’ characteristics. Measurements were collected at three distinct time points: preoperatively (Time 1), postoperatively between the 12th and 14th day (Time 2), and after stoma closure, approximately one year later (Time 3). Statistical analysis was performed using the SPSS 26.0 statistical package and the statistical significance level was set at p < 0.05. Results: The proportion of participants reporting moderate levels of anxiety (scores 8–10) was 15.6% at Time 1, which increased to 27.1% at Time 2, and had a slight increase to 28.1% at Time 3. The increase was statistically significant between Time 1 and Time 2 and at Time 1 and Time 3 (p < 0.001). Regarding high levels of anxiety (scores >11), the percentage of affected individuals increased from 13.5% at Time 1 to 17.7% at Time 2 and reached 15.6% at Time 3. The comparison between Time 1 and Time 2 revealed a statistically significant increase (p = 0.016), while the subsequent decrease between Time 2 and Time 3 was not statistically significant (p = 0.508). In terms of depression, at Time 1, 84.4% of patients had low depression, which decreased significantly to 56.3% at Time 2 and 39.6% at Time 3 (p < 0.001 for all comparisons). The percentage of patients who were moderately depressed at Time 1 was 9.4%; this percentage increased significantly to 32.3% at Time 2 and remained high, reaching 29.2% at Time 3. Finally, the proportion of patients who had high levels of depression at Time 1 was 6.3%, a figure that rose to 11.5% and 31.3% for Time 2 and Time 3, respectively. Conclusions: Anxiety and depression experienced by colorectal cancer patients undergoing ileostomy surgery escalate postoperatively and remain at high levels after ileostomy closure. Understanding these mental health challenges is crucial for providing comprehensive patient care. Further research is needed on the early recognition and management of these emotional difficulties, which are key elements of holistic oncology care. Full article

Energetic powder processing includes comminution, sieving, drying, conveying, mixing, and packaging, all of which determine product performance and safety. With growing requirements for efficiency and reliability, numerical simulation has become essential for analyzing mechanisms, optimizing parameters, and supporting equipment design. This review summarizes recent progress in simulation techniques such as the discrete element method (DEM), computational fluid dynamics (CFD), and multi-scale coupling while also evaluating their predictive capabilities and limitations across various unit operations and safety concerns such as electrostatic hazards. It, thus, establishes the core “property–parameter–performance” relationships and clarifies mechanisms in multiphase flow, energy transfer, and charge accumulation, and highlights the role of symmetry in improving simulation efficiency. By highlighting persistent challenges, this work lays a foundation for future research, guiding the development of theoretical frameworks and practical solutions for advanced powder processing. Full article