Original Design Research Articles

A clinical comparative analysis using an optical tracking device versus conventional tracking device in the production of occlusal appliances.

Optical tracking devices (OTDs) hold promise for enhancing patient-centered prostheses, but their efficacy remains underexplored. This clinical study aimed to comprehensively evaluate differences in static and dynamic occlusions among occlusal appliances fabricated using optical tracking, conventional tracking, and average articulator values (AAVs), providing insights into their efficacy in clinical and research-based practices. Twelve dentate participants aged over 25 years, with Angle Class I and II occlusal relationships, were enrolled. Occlusal appliances were fabricated by different condylar guidance values obtained by the three systems. The condylar guidance values were measured by an OTD via MODJAW, a conventional tracking device (CTD) via Cadiax compact 2, and the AAV with Bennett angle 10°, immediate mandibular lateral translation 0.5mm, and sagittal condylar inclination (SCI) 35°. Occlusal appliances were designed using computer-aided design (CAD) software with the measured condylar guidance values from three systems. Subsequently, standard tessellation language (STL) files were transferred to computer-aided manufacturing (CAM) software for 3D printing with photopolymer resin. Each participant received three occlusal appliances fabricated using the three different systems. The accuracy of the systems was evaluated by accessing the clinical outcomes of the occlusal appliances. After placement, the number of contact points in maximal intercuspation position (MIP) and dynamic occlusion interferences were recorded, along with any discrepancies between designed and recorded contact points. Any anterior open bites at MIP with the appliance in place were measured from the maxillary incisal edge to the mandibular incisal edge. Statistical analysis included Kruskal-Wallis one-way analysis of variance (ANOVA) and Mann-Whitney tests with Bonferroni correction for pairwise comparisons (α=0.05). In assessing static occlusion, significant differences were found in contact point discrepancies at MIP. OTD exhibited the lowest mean discrepancy of contact points compared with the original design (1.833±0.312), followed by CTD (4.083±0.758) and AAV (4.833±1.389), with a statistical significance (p=0.047). At the final protrusive position, OTD (0.400±0.204) and CTD (1.400±0.438) methods showed significantly lower discrepancies compared with AAV (3.583±0.352) (p<0.001). Additionally, the OTD method demonstrated a statistically significant reduction in anterior open bite at MIP (0.115±0.044mm) compared with AAV (0.617±0.246mm) (p=0.049). In dynamic occlusion, OTD showed no interferences in all subjects during protrusive movement, significantly outperforming both CTD (0.917±0.474) and AAV (0.417±0.202) (p=0.033). No significant differences were observed among the methods for working and nonworking side laterotrusive movements. The OTD offers superior accuracy over traditional methods, with reduced discrepancies and interferences in occlusal appliance fabrication, signifying a substantial advancement in mandibular movement assessment and improving treatment efficiency and outcomes in clinical practice.

Design of a two-seater seaplane wing spar structure with composite materials

A two-seater, mono-wing seaplane was initially developed for survey and rescue operations, with an empty weight of 470 kg and a maximum takeoff weight of 650 kg. Fiber-reinforced composite materials, consisting of fiber reinforcement and thermosetting polymer, were used in this airframe to reduce weight because the structural properties can be customized by adjusting the orientation of the fiber fabric layup and removing redundant material, which is impossible with metal. This paper presents a comprehensive overview of the design process for the aircraft's primary I-beam wing spar, employing composite material. Before conducting design calculations, it is critical to consider the variability of characteristics of composite materials caused by fabrication conditions such as temperature, humidity, and defects. As a result, it is imperative to conduct thorough testing of carbon fiber-reinforced composites following many different testing requirements. The coupon tests capture critical characteristics such as strength, stiffness, and Poisson's ratio across several orientations. The wing spar I-beam structure was subsequently developed with three primary considerations: stiffness (maximum deflection), strength, and stability (structural buckling). Following preliminary sizing of the I-beam wing spar, a simple initial layup was recommended, with primary loading in each component. The initial design was then subjected to a more detailed calculation using classical lamination theory, which took into account distributed load along the wing, spar taper, ply-drops along the span, and composite layup guidelines in order to reduce structural weight while ensuring the main spar's ability to withstand operational loads effectively. The calculating results show that the spar with an optimized composite design has a lighter weight than the original design by around 43%, while it can withstand the same loads with no analytical failure.

Trial Design of a Truss Bridge Prefabricated Using a Rectangular Steel Tube—Ultra-High-Performance Concrete Composite

In order to promote the development of bridge assembly technology and accelerate the application of rectangular steel-tube–concrete composite truss bridges, this study focuses on the Yellow River Diversion Jiqing Main Canal Bridge as the engineering example and conducts a numerical analysis of a rectangular steel-tube–concrete composite truss bridge. Based on the results of the analysis, structural optimization is achieved in three dimensions—structural design, construction methods, and force analysis—leading to the establishment of key design parameters for through-type ultra-high-performance rectangular steel-tube–concrete composite truss bridges. The results show that filling the hollow sections with ultra-high-strength concrete can significantly enhance the load-bearing capacity. Additionally, employing prestressed concrete components addresses the bending and tensile load capacity challenges of composite structures, thus maximizing the material strength advantages. The proposed preliminary design scheme incorporates prestressed PBL-reinforced tie rods filled with ultra-high-performance concrete with optimal design parameters, such as high span ratios, wide span ratios, and ideal segment lengths, are suggested to ensure that the strength, stiffness, and stability comply with relevant standards. While ensuring that the structure meets safety, applicability, and durability criteria, the preliminary design scheme reduces steel usage by 23.5%, concrete usage by 11.6%, and overall costs by 17.29% compared to the original design. The proposed design demonstrates distinct advantages over the original in terms of mechanical performance, construction efficiency, economic viability, and durability, highlighting its promising application potential.

Structural Evolution of an Optimized Highly Interconnected Hierarchical Porous Mg Scaffold under Dynamic Flow Challenges.

The development of Mg and its alloys as bone screws has garnered significant attention due to their exceptional biocompatibility and unique biodegradability. Notably, the controlled release of Mg2+ ions during degradation can positively influence bone fracture healing. The advantages of Mg raise appeal for application in bone tissue engineering. However, porous Mg scaffolds, while offering high surface areas, face challenges in maintaining slow degradation rates and preserving interconnectivity, which are crucial features for tissue ingrowth. To address these issues, this study introduces a highly interconnected hierarchical porous Mg scaffold and investigates its degradation behavior within a bioreactor, simulating body fluid flow rates to mimic the in vivo degradation performance at different implantation sites. The focus lies on elucidating the evolution of the porous structure, particularly the impact of degradation behavior on scaffold interconnectivity. Our findings reveal that the initial high interconnectivity of the scaffold is significantly influenced by the flow rate. The dynamic fluid flow modulates the transport of degradation byproducts and the deposition patterns. At lower flow rates, Mg2+ ions accumulate within pores, leading to the formation of substantial deposits that directly reduce porosity. Specifically, after 42 days, porosities decreased to 68.80 ± 2.31, 58.52 ± 2.53, and 41.25 ± 2.82% at flow rates of 2.0, 1.0, and 0.5 mL/min, respectively. This porosity reduction and pore space occlusion by deposits sequentially hinder the interconnectivity. The magnitude of decreased porosity could be used to evaluate the ability of the microarchitecture to maintain scaffold interconnectivity. Meanwhile, the long-term degradation deposition behavior of the highly interconnected hierarchical porous Mg scaffold potentially revealed the structural integrity loss from the original design to its in vivo degraded structure at different body fluid flow rates. The present work might bring valuable insight into the design of pore strut and interconnectivity characterization methods for the progress of a high-performance tissue engineering scaffold.

Design and Stability Study of a Distortion-Tolerant Axial Compressor Based on an Alternating Stator Layout

To effectively suppress flow separation in the corner regions of a compressor, improve aerodynamic performance, and enhance distortion tolerance, this study focuses on a single-stage high-load transonic axial flow compressor and introduces a novel and effective unconventional stator design known as an alternating stator (AS) vane layout. This study examines the relationship between the AS layout and the flow separation in the corner regions from a fluid dynamics perspective and investigates the enhancement effects of different AS designs on the compressor's aerodynamic performance and stability margin (SM). Numerical investigations indicate that the alternating layout scheme, which is developed by locally adjusting the inlet geometric angle of the stator vanes, can effectively improve the aerodynamic performance and stability of the compressor. Compared to the original compressor design, the scheme with a 12° adjustment in the blade tip's geometric angle significantly increases both the total pressure ratio and efficiency. This scheme also enhances the SM by 34.69%. With this alternating layout, the novel stator arrangement induces differentiation in the flow field structure among adjacent passages. Internally, an alternating separation forms at the top and root corner regions of the adjacent stator passages, effectively preventing extensive flow separation from occurring at the top or root corner regions of the compressor and thereby delaying a compressor stall. When this design is applied to the compressor stage with inlet distortion conditions, the AS scheme with a 12° adjustment in the blade tip's geometric angle effectively improves the compressor's aerodynamic performance and distortion tolerance and holds significant potential for expanding the stable operating range of the compressor with inlet distortion conditions. Relative to the original design, the SM of the AS compressor can be increased by 83.09%.

A prestressed anchor-grouting reinforcement method based on the novel HFQSME grouting material for deep high-stress fractured rock mass

In order to control the surrounding rock of deep high-stress roadways, a new prestressed anchor-grouting reinforcement method was proposed with an engineering background of the 1780 ventilation roadway of Shiyakou Coal Mine. A high-fluidity quick-setting micro-expansion (HFQSME) grouting material had been developed through superplasticizer, accelerator, and expansion agent. The results showed that the optimal ratio of HFQSME grouting material was superfine Portland cement of 95%, superplasticizer of 0.5%, accelerator agent of 0.5%, expansion agent of 5.0%, and water-binder ratio of 0.4. The fluidity, initial setting time and expansion rate of the grouting material were 47cm, 41minutes and 0.12%, respectively. The grouting reinforcement effect of superfine slurry and HFQSME grouting material on rock mass with different degrees of fragmentation was investigated. The peak strength of rock mass with two degrees of fragmentation reinforced by HFQSME grouting material was 166% and 233% higher than that of superfine slurry. The macro reinforcement effect of HFQSME grouting material on the surrounding rock of deep high-stress roadway was evaluated through industrial testing. The prestressed anchor grouting method was used to improve the original support design scheme, and data monitoring and analysis were conducted on site. Compared with the original supporting scheme, the deformation of the 1780 ventilation was significantly reduced. Therefore, HFQSME grouting material had good adaptability for the surrounding rock of deep high-stress roadways.

A study on the co-optimization design method of diesel engine in-cylinder combustion performance and steel piston heat transfer characteristics: A new pit array combustion chamber structure

Steel pistons have become the optimal solution for high-performance engines. However, the efficient design and widespread application of steel pistons are constrained by physical parameters such as high density and low thermal conductivity. In this paper, a parameterized structure of pit arrays on the center, bottom, and top surfaces of the combustion chamber was set up by utilizing the high mechanical strength of steel pistons. Subsequently, the diesel engine in-cylinder combustion performance and steel piston heat transfer characteristics were co-optimized for the design. Ultimately, the structure of the researched design with indicated specific fuel consumption and thermal stress control was obtained. The study results show that the top surface mass of the researched design can be reduced by 8.32 g. The researched design can exhibit better combustion and emissions performance. Moreover, the pit structure can allow the fuel to touch the wall with less energy loss, thereby alleviating the problems of fuel accumulation on the wall and wall-adhered combustion. In addition, the maximum thermal stress in the researched design decreases by 15.68 MPa, or 3.93 %, while increasing the highest temperature by only 2.30 °C compared to the original design.

Exploration of Obligations and Rights of the Positive and Negative Requirements for obtaining the Protection of a Colombian Designation of Origin for the coastal cheese of the Colombian Caribbean

Exploration of Obligations and Rights of the Positive and Negative Requirements for obtaining the Protection of a Colombian Designation of Origin for the coastal cheese of the Colombian Caribbean

Limitations of CDX and PDX methods using for cultivation of malignant ovarian neoplasms and their mathematical justification

The article presents information on the most popular methods of culturing human malignant neoplasms to implement the obtained fundamental knowledge into the basis of translational research in oncology. A brief description of each of them allows you to decide on the possibility of including the technique in experimental work. The first approximation to the formation of the logic of the mathematical justification of the design of an experiment on modeling human malignant neoplasms is given.Also, using the example of a brief description of the original design of the experiment of scientists from the Khanty-Mansiysk State Medical Academy and the Tyumen State Medical University, the logic of constructing the design of such an experiment as part of the research work is demonstrated. An idea is formed about the need to include fundamental and translational stages in clinical experimental work as part of a unified strategy for responding to the great challenges of personalized medicine. An idea is formed about the need to include fundamental and translational stages in clinical experimental work as part of a unified strategy for responding to the great challenges of personalized medicine.

Transcatheter bicuspid venous valve prostheses: fluid mechanical performance testing of artificial nonwoven leaflets

BackgroundChronic venous insufficiency (CVI) is a common disease with a high prevalence. Incompetent venous valves are considered as one of the main causes. Besides compression therapy, various surgical therapies are practiced, whereby the reconstruction of valves is of central importance. There is an unmet clinical need, no valve prosthesis is commercially available to date. This work introduces two versions of a patented prosthetic bicuspid valve design made of electrospun thermoplastic silicone polycarbonate polyurethane (TSPCU) nanofiber leaflets attached in a nitinol stent, and their performance in static and pulsatile operation.ResultsThe valves mainly fulfill the requirements widely accepted in literature. Valves of both versions were functional in the physiological pressure range up to 50 mmHg with design specific differences.ConclusionsThe here introduced design versions act as a platform technology and can be tailored for an intended implantation site. Evaluation of the original and modified valve concept demonstrated efficacy, with limitations at higher loads for original design. At the current state, the modification is preferable for fabrication, as one processing step is eliminated. Moreover, specific design recommendations could be drawn for valves of similar basic structure. Future work will focus on long-term performance and biocompatibility prior to the initiation of preclinical in vivo studies.

Optimum design of contra-rotating wind turbines with adjacent rotors

A downstream installed contrarotating rotor can efficiently extract the residual kinetic energy of a wind turbine wake, thus increasing the overall power coefficient. A significant interaction between the two rotors exists so that, to completely exploit the device potential, it is not advisable to adopt a classical design procedure conceived for a single-rotor configuration, as commonly seen in the existing literature. In particular, current approaches also oversimplify the design of the back rotor by merely mirroring the front rotor geometry, rather than optimising it for its power extraction duties. To fill this knowledge gap, the paper presents an original design strategy expressly conceived for contra-rotating wind turbines. This new approach optimises the geometry of both rotors, fully accounting for the interaction between them and the wake rotation at the outlet of the front wheel. The procedure adopts a calculus of variations approach aimed at maximising the overall power coefficient. It relies on a classical actuator disk model and is it valid for two adjacent rotors with the same diameter. As a result, the optimal chord and pitch distributions of the two rotors are evaluated for any combination of the front and back tip speed ratios. The procedure can be applied to marine turbines, too.

Increasing the operating time of pumping units of water-reducing wells through the use of self-cleaning filters

Relevance. At enterprises engaged in open-pit mining, water-reducing wells equipped with submersible installations of electric submersible pumps are widely used in drainage systems. A significant content of particles of mechanical impurities in the pumped-out well fluid causes intense hydro-abrasive wear of the working stages of the electric submersible pumps. Among the existing methods of combating hydro-abrasive wear of submersible pumps in water-reducing wells, the simplest, most economical and effective is the use of filters of various designs. An urgent task is to increase the operating time of submersible electric submersible pumps while reducing the time and costs for cleaning or replacing filters. Aim. Justification of the designs and operating parameters of a self-cleaning filter and tubing string extension included in the electric submersible pump assembly of a dewatering well. Methods. Static calculations of deformation of the tubing column and the tubing column extension under the influence of overpressure. Results and conclusions. The authors have carried out the analysis of an electric submersible pump functioning in the dewatering wells of quarries during the development of mineral deposits by the open method. It was revealed that the main reason for the failure of the electric submersible pumps is the hydro-abrasive wear of the working stages of the submersible pump. The authors propose a method to increase the operating time of the electric submersible pumps in dewatering wells complicated by intensive removal of particles of mechanical impurities by using a self-cleaning filter of the original design. It is noted that a promising direction of development of the drive for self-cleaning filters is the use of deformation of the tubing column. Based on the calculations carried out, it was concluded that the small depths of dewatering wells cause an insufficient amount of deformation of the tubing string to clean the filter element. To increase the length of the reciprocating movement of the electric submersible pumps relative to the production string of a dewatering well, it is proposed to use a tubing string extension of an original design. The operating parameters of the tubing string extension were calculated, which showed the possibility of providing the required amount of controlled reciprocating movement of the electric submersible pumps in the well to restore the throughput of a self-cleaning filter.

Nozzle structure optimisation in a photovoltaic irrigation system

AbstractOn the basis of the significant impact of the sprinkler nozzle structure in photovoltaic irrigation systems, the nozzle parameters are optimised to improve sprinkler adaptability and irrigation uniformity under different light intensities. An experimental test and numerical simulation were conducted to analyse the influence of nozzles with distinct parameters on the spray irrigation effect. Taking the irrigation uniformity coefficient as the optimisation goal and the nozzle outlet shape, outlet area and straight flow channel length as the optimisation variables, an orthogonal experimental design was employed, and the optimal solution was obtained via range analysis. The experimental results indicate that the sprinkler performs best when the outlet shape is circular, the nozzle outlet area is 7 mm2 and the flow channel length is 2 mm. The optimal nozzle characteristics were tested and compared with those of the original design, and numerical simulation was used to demonstrate the optimised internal flow mechanism. The results demonstrate that the optimised flow rate and spray range are improved, and the working pressure and rotation period are significantly reduced, enabling the system to adapt to a more extensive range of light intensities. The radial water distribution structure is better, and the combined application rate and uniformity coefficient are also significantly improved. In addition, the sprinkler outlet speed is more consistent, and the area of the high‐speed zone in the spray plate increases, which is conducive to reducing energy loss and enhancing sprinkler irrigation uniformity.

Mechanism and Control Strategies for Current Sharing in Multi-Chip Parallel Automotive Power Modules

Multi-chip parallel power modules are highly favored in applications requiring high capacity and high switching frequency. However, the dynamic current imbalance between parallel chips caused by asymmetric layouts limits the available capacity. This paper presents a method to optimize dynamic current distribution by adjusting the lengths and connection points of bond wires. For the first time, a response surface model and nonlinear constraint optimization algorithm are introduced, along with parameter analysis based on finite element methods, to establish the response surface models for the parasitic inductance of bond wires and DBC (direct bonded copper). By leveraging the optimization goals for parasitic inductance and the analytical expressions of all response surfaces, the dynamic current sharing issue was transformed into a nonlinear constrained optimization problem. The solution to this optimization problem identified the optimal connection points for the bond wires, enhancing dynamic current sharing performance. Simulations and experiments were conducted, revealing that the optimized automotive-grade module exhibited a significant reduction in current differences between parallel branches, from 41.7% to 5.03% compared with the original design. This indicated that the proposed optimization scheme for adjusting bond wire connection points could significantly mitigate current disparities, thereby markedly improving current distribution uniformity.

Effect of multiple appendages on maritime surveillance ship resistance at various ship speeds

Resistance is a critical factor affecting the operational performance and economic efficiency of marine surveillance ships. To enhance the enforcement efficiency of marine surveillance ships, this study investigates the impact of five types of appendages on ship resistance performance. In this study, resistance experiments and numerical simulation calculation on the ship model were carried out. Based on Computational Fluid Dynamics (CFD) and the Volume of Fluid (VOF) method, the study captures the variations in ship resistance and the free surface Cases around the hull. A comparative analysis was then conducted on the resistance effects of different appendages installed on the ship model. It was found that the installation of stern shaft brackets, bilge keels, and ductkeel increased the ship's resistance. In contrast, the installation of spray rails reduced resistance by approximately 2.5%. However, the effectiveness of the spray rails diminished at high speeds due to their inability to prevent wave overtopping. Since stern flaps are commonly used drag-reducing appendages, this study improved the original design. Comparative analysis revealed that the modified curved structural design of the stern flaps exhibited enhanced drag reduction capabilities.

Dynamic blade tip clearance control of aero-engine by the integration of cooling air with fuel thermal management system

In advanced aero-engines, the precise control of tip clearance and thermal management of the fuel system are two important measures to improve the transient performance of the aero-engine. In order to optimize the overall performance of an aero-engine during a full-flight mission, this paper proposed a novel architecture integrating active clearance control system and aero-engine fuel thermal management system, which utilizes fuel heat sink to achieve indirect regulation of the tip clearance. Furthermore, a set of critical optimization criteria for the new architecture was derived to achieve dynamic heat distribution in the fuel thermal management system. Subsequently, the transient performance was tested under a complete flight mission with a duration of 10,000 s. The calculation results indicate that the new architecture effectively raises the fuel temperature to its maximum allowable value during low thermal load phases, which increases heat dissipation capability of the system. The new architecture exhibits a significant effect on the control of the tip clearance during the ground idle, cruise, and engagement phases, resulting in a maximum increase of 1.86% in the relative efficiency of the high-pressure turbine. The new architecture also prevents the engine from experiencing excessively narrow tip clearance during acceleration. Ultimately, the new architecture achieves a 2.59% reduction in total fuel consumption compared to the original design. The new architecture has significant potential to improve engine efficiency and increase operational safety.

Dietary inclusion of fibrous corn silages reduces gastric mucosa damage in fattening heavy pigs

BackgroundSeveral surveys conducted at slaughter sites have highlighted that gastric lesions are a widespread issue in fattening pigs, mainly due to feeding regimes. Diets with small particle sizes and low fibre contents guarantee high digestibility and performance but generate more rapid stomach emptying with a negative effect on gastric mucosa integrity. Providing fattening pigs with fibrous materials (e.g., straw provided in racks) or coarse fibrous ingredients (e.g., coarse silages) reduced the presence of gastric ulcers. The present research compares a traditional corn-soy-based diet with an experimental diet where bran and a portion of corn meal was substituted with whole ear and whole plant corn silages at the maximum dosages permitted by new Protected Designation of Origin for Italian dry-cured ham (20 and 10% of DM, respectively). This study aimed to examine the impact of the inclusion of corn silages in the diet on the productive performance of heavy Italian pigs and their ability to mitigate gastric mucosa damage.ResultsThe growth performances were satisfactory (750–800 g/d) given the advanced interval of growth of animals (from 120 to 180 kg). However, the inclusion of corn silages tended to reduce the growth rate by 5–6% due to the reduction of organic matter digestibility, without compromising the slaughter traits or the back-fat fatty acid profile. The experimental diet substantially affected both stomach development and mucosal integrity. The first consequence was an increase in stomach weight of approximately 6% (P < 0.01) but the most notable advantage of coarse feeding was a reduction in stomach damage severity, with a low number of cases with higher scores in animals fed coarse materials (P < 0.01).ConclusionsThe dietary inclusion of corn silages (30% of diet DM) decrease effectivelly the severity of stomach damage in finishing heavy pigs. Based on the feeding trial performances, the perspective of feeding heavy pigs corn silage should consider specific agronomic and harvesting techniques to improve digestibility and not reduce the growth rate.

Design principles for accurate folding of DNA origami

We describe design principles for accurate folding of three-dimensional DNA origami. To evaluate design rules, we reduced the problem of DNA strand routing to the known problem of shortest-path finding in a weighted graph. To score candidate DNA strand routes we used a thermodynamic model that accounts for enthalpic and entropic contributions of initial binding, hybridization, and DNA loop closure. We encoded and analyzed new and previously reported design heuristics. Using design principles emerging from this analysis, we redesigned and fabricated multiple shapes and compared their folding accuracy using electrophoretic mobility analysis and electron microscopy imaging. Redesigned shapes showed 6- to 30-fold improvements in yield compared to original designs. We demonstrate accurate folding can be achieved by optimizing staple routes using our model and provide a computational framework for applying our methodology to any design.

Understanding bimodal seas, shingle beach response and flood risk at Hayling Island, UK

Beach management through nourishment and annual recycling has been applied for over 37 years to manage flood and coastal erosion risk to 1700 properties at Eastoke, Hayling Island, UK. This form of natural flood risk management has proved successful in avoiding the annual flooding that blighted this area previously. However, there have been unexpected storm events that have caused beach erosion and localised flooding. Using long-term nearshore wave datasets and state-of-the-art statistical methods, new multi-variate extreme wave conditions were derived and applied to assess beach performance. Eastoke beach was found to meet its original design criteria of a 0.5% AEP standard of protection for unimodal wave conditions. However, it experiences greater rollback erosion, wave overwash and therefore flood inundation under certain (but not all) bimodal wave conditions, causing uncertainty around the future standard of protection. Communicating these inconsistencies to practitioners and a non-specialist audience is challenging as we tend to oversimplify, despite every beach and storm being unique. Better understanding of mixed beaches, both in situ and through parametric and numerical models, would reduce uncertainty to ensure communities are resilient to climate change.

ANÁLISE DE FALHA DAS TUBULAÇÕES DO GRELHADO DA FORNALHA DE UMA CALDEIRA INDUSTRIAL A VAPOR

This study addresses a comprehensive analysis of the failure mechanism in the grill tubes of a mixed boiler used to generate saturated steam in a manufacturing plant. After a renovation in 2020, early pipe failure in 2021 raised concerns. Methods such as liquid penetrants, thickness measurement and computer simulation were used in this study. Results indicated that the work regime, thermal cycles and mechanical flexural loading contributed to the failures. Deviations in the original design, such as the lack of reinforcements and the reduction in recommended tube thicknesses, were also identified. The multidisciplinary analysis strengthened the evidence of the failure mechanism due to corrosion, fatigue and cracking. The study identified causes and also provided valuable information to improve boiler reliability and performance.