Hole Size Research Articles

Internal limiting membrane peel size and macular hole surgery outcome: a systematic review and individual participant data study of randomized controlled trials.

There is no consensus regarding the optimal internal limiting membrane (ILM) peel size during vitrectomy for idiopathic full thickness macular holes (iFTMH). A systematic review was performed to identify randomized controlled trials (RCTs) comparing vitrectomy with ILM peeling of differing sizes in adults with iFTMH. Individual participant data was obtained including relevant baseline variables. The effect of different ILM peel sizes, divided into "small" (1-disc diameter [DD] in radius or less) and "large" (>1-DD in radius) were analysed on primary hole closure and postoperative visual acuity (VA) at 6 months. A subgroup analysis analysing for the effect of macular hole size on the same outcomes was also performed. Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) was used to assess the certainty of evidence. Five RCTs with 370 eyes were included. Primary closure was achieved in 74.7% in small peel group compared to 84.8% in large peel group (p = 0.016). Multilevel logistic regression showed that a peel radius of >1-DD probably improved hole closure slightly with odds ratio (OR) of 1.20 (95% CI: 1.11-1.31, p < 0.001) and a number needed to treat (NNT) to benefit of 31 (95% CI: 21-53). ILM peel size likely did not affect VA. The mean difference in postoperative VA was a -0.05 logMAR gain (2-3 ETDRS letters) (95% CI: -0.13 to 0.02, p = 0.155) in vision with a large ILM peel radius. The GRADE certainty of evidence was moderate for both outcomes. A significantly higher closure rate was found in the large peel group for iFTMH >400 microns with an OR of 1.24 (95% CI: 1.11-1.38, p < 0.001) and NNT to benefit of 21 (95% CI: 17-50), but not in holes <400 microns (OR 1.05 (95% CI: 0.93-1.18, p = 0.396)). Performing ILM peel of more than 1-DD in radius likely improves closure rates for iFTMH although the effect size is relatively small. The effect is greater in holes >400 microns. ILM peel size probably has no significant effect on postoperative VA.

Comparative analysis of damage to the marine pipeline by linear shaped and blasting charges

The blow-up of the marine pipeline raised an international uproar. The destruction of the pipeline not only causes great economic losses but also has a significant impact on the ecological environment. In order to investigate the damage process of the marine pipeline, a fluid–structure interaction underwater explosion model based on the Arbitrary Lagrange Euler method is established. Damage effects of the blasting charge and linear-shaped charge (LSC) with equal charge (50 kg Rotary Deuterated eXchange) are compared and analyzed. The calculation results show that the steel pipes are mainly subject to localized shear damage and concave deformation. The penetration hole caused by blasting charge has a length of 530 mm and a width of 125 mm, while the size of the penetration hole caused by LSC is 1042 mm in length and 304 mm in width. In addition, the protective concrete layer appears different degrees of shedding and cracking. However, neither of the charges causes significant damage to the lower surface of the pipeline. Then the damage results for the two types of charge arranged on both sides of the pipeline are further compared and analyzed. Blasting charge form 579 mm long and 97 mm wide penetration holes on both sides of the pipeline. Concave deformation occurs near the penetration hole, but the outer sides of the pipeline are less deformed. As for LSC, it can form 881 mm long and 288 mm wide interconnected penetration holes on the pipeline, and the pipeline shows signs of overall fracture.

Study on the preparation and properties of lignin-based flexible polyurethane foams with NaCl as a medium.

Currently, most polyols used in polyurethane foam (PUF) synthesis are derived from petrochemicals. However, lignin as the most abundant aromatic biopolymer rich in hydroxyl groups, is a suitable filler for synthesizing polyurethane foam. Therefore, in this study, Kraft lignin (KL) was utilized as a partial substitute for flexible polyethylene glycol 400 (PEG400). After adding 15 % KL, NaCl was introduced as a medium for synthesizing LFPUF and Polydimethylsiloxane (PDMS) was used as a foam stabilizer. Lignin-based flexible polyurethane foam (LFPUF) with high elasticity was synthesized. The aromatic ring structure of KL acted as a reinforcement for the foam, while the flexible PEG400 provided excellent flexibility to LFPUF. Na+ interacts with oxygen atoms in the long chain of PEG to form a cyclic crown ether structure. This promotes proximity and ordering of the hydroxyl groups, thereby facilitating proton transfer and optimising the cell size of the foam. Ultimately, the foam synthesized with 3 % NaCl (LFPUF-3%NaCl) exhibited an average cell size and hole size of 484.1 and 183.6 μm, respectively, significantly smaller than those of the foam synthesized without NaCl (843.5 and 249.3 μm, respectively). The foam resilience and elastic recovery of LFPUF-3%NaCl were 39.56 and 99.03 %, respectively, which was higher than that of the foam synthesized without NaCl (20.36 % and 97.08 %, respectively). In addition, LFPUF-3%NaCl maintained a high elastic recovery of 97.61 % after 20 cycles of compression. The egg drop test demonstrated that the foam effectively provided protective cushioning for fragile items.

Synthesis and Characterization of Diopside Nanoparticles for Drug Delivery by sol-gel

In this research, used the sol-gel method to prepare diopside from the raw materials, which include magnesium nitrate, calcium sulphate, and silicates with special solutions to mix them. After that, we used two stages of heating, a temperature stage of 120 Celsius for the purpose of getting rid of water and some volatile materials, then the second stage is a high-temperature sintering stage, which then. The material was crystallized and then calcined from 600 to 1100 degrees Celsius. The material was then tested with devices such as x-ray diffraction (XRD), Thermal gravimetric analysis (TGA ) and Differential thermal analyses (DTA), Fourier transition infrared (FTIR), Scanning emotion micro scoping (SEM), Brunauer –Emmett-Teller (BET) analysis Thus, we obtained a nano diopside material with an internal hole size of 3.5 nanometers, which is required as a drug delivery with high mesopours.

Study of High Performance Nanoscale Channel Length Vertical Transistors with a Self-Aligned Blocking Layer.

A transistor design employing all vertically stacked components has attracted considerable attention due to the simplicity of the fabrication process and the high conductivity easily realized by achieving nanolevel short channel lengths with two-dimensional current paths. However, fundamental issues, specifically the blocking of the gate electrical field to the semiconductive channel layer and high leakage current at the "off" state, have impeded this configuration in becoming a major transistor design. To address these issues, it has been proposed to introduce a blocking layer (BL) with embedded hole structures and source electrode with embedded hole structures, enhancing gate field penetration and carrier modulation. The hole structure embedded in the source and the BL on the drain induced a desirable combined effect of gate field penetration and carrier pathway modulation. The align accuracy and the hole size difference between BL and source electrode were confirmed as the most important design parameters for high performance of a transistor. We therefore proposed a self-aligning lithography method using a built-in mask that allows high alignment accuracy between the source hole structure and the BL hole structure on the drain over a large area without a high-resolution process system. This method also enables easy and fast fabrication of nanoscale channels with high performance. This design resulted in a transistor with an output of 28 mA/cm2 and an on-off ratio exceeding 106 at 1 mV of VDS. However, at 3 V of VDS, the off-current increased significantly due to short-channel effects in the all metal electrode design. To solve this issue, Fermi level-tunable graphene replaced metal electrodes, maintaining an off-current below 10 pA and an on-off ratio around 107 at 3 V. In addition, the device demonstrates robust electrical properties to light without any special treatment and is stable with a threshold voltage shift of less than 1 V under bias stress. This study demonstrates that the proposed vertical transistor design is a viable candidate as a new major transistor design for various applications.

Machine learning approach for prediction of hole oversize using acoustic emission signal features in ultrasonic machining of inconel 718

ABSTRACT The material removal in the ultrasonic machining process is due to the fracture of the workpiece material. The fracture is owing to the energy transfer by vibrating abrasive particles. The vibrating particles impact the workpiece surface and machining takes place, leading to the size of the machining hole, which is of interest to understand to guarantee efficient machining with accuracy and precision. In the current investigation, the hole oversize (HOS) during the ultrasonic machining of Inconel 718 super alloy is attempted. An acoustic emission sensor is integrated with the machining setup, and signal information is extracted in the time and time-frequency domain. The features and process parameters are input to a support vector regression model to estimate HOS. The model developed for HOS prediction yields an accuracy of 97.87%. The developed model can be beneficial for the real-time monitoring of HOS during the ultrasonic machining process for industrial and remote applications.

High-resolution digital still camera-based nondestructive detection of blind holes in Plexiglas by thermal loading and phase-stepping shearography

We used the phase-stepping shearography technique to detect blind holes of various sizes and depths in a Plexiglas (PMMA or polymethyl methacrylate) plastic block. The block was strongly heated (raising the temperature by about 80C) from the back side by a low-cost infrared heater, and then cooled by convective cooling. Hole sizes down to 10 mm diameter and 15 mm remaining thickness (depth) were quickly detected from the other (blind) side during heating. The temperature profiles at different places on the block were monitored as functions of time for heating and cooling. The method, that exploits high spatial resolution of a digital still camera, suggests the detection of strain abnormalities by non-destructive testing of plastic components.

Hybrid hexa-octagonal photonic crystal fiber with excellent guiding properties for sensing and communication applications

Abstract A novel hybrid hexa-octagonal photonic crystal fiber (PCF) is designed by integrating a hexagonal arrangement of elliptical air holes in the core using soft glass and an octagonal lattice of circular air holes in the cladding. This study presents a comparative analysis of the fiber parameters, including confinement loss, non-linearity, effective area, birefringence, and chromatic dispersion, for two configurations: (i) hybrid hexa-octagonal PCF with a horizontal arrangement of air holes in the core, and (ii) hybrid hexa-octagonal PCF with a vertical arrangement of air holes in the core. Both configurations are examined by varying the pitch size, arrangement, and shape of air holes while maintaining identical design and operational features. Simulations are conducted using the full vector finite element method (FEM). Numerical results indicate that the confinement loss for vertically and horizontally arranged air holes is 1.098 × 10−5 dB km−1 and 1.0743 × 10−5 dB km−1, respectively. High birefringence values of 0.07366 and 0.00434, and chromatic dispersion values of −3404.665 ps nm−1 km and −3391.6705 ps nm−1 km, respectively, are obtained at an operating wavelength of 1.55 µm, making the fiber suitable for sensing and communication applications. The designed hexa-octagonal PCF has potential applications in the fiber optic sensing due to its assorted features.

Feasibility study of patient-specific four-dimensional in vivo tracking system for high-dose-rate brachytherapy: Experimental evaluation.

High-dose-rate (HDR) brachytherapy using Iridium-192 as a radiation source is widely employed in cancer treatment to deliver concentrated radiation doses while minimizing normal tissue exposure. In this treatment, the precision with which the sealed radioisotope source is delivered significantly impacts clinical outcomes. This study aims to evaluate the feasibility of a new four-dimensional (4D) in vivo source tracking and treatment verification system for HDR brachytherapy using a patient-specific approach. A hardware system was developed for the experiments, featuring a high-resolution compact gamma camera with a redesigned diverging collimator, enhanced detector, and precision control system. The collimator was redesigned to improve spatial resolution by reducing the hole size and increasing the hole array, while reducing the pixel size of the detector and increasing the number of pixels. The performance was evaluated using Monte Carlo simulations, which demonstrated significant improvements in spatial resolution. Experiments were conducted in a controlled setup using a phantom to simulate clinical conditions. The phantom was positioned at various distances from the gamma camera (327.30, 377.30, and 427.30mm) and imaged at multiple angles. The accuracy of the system was tested in four different cases: three with fixed distances and one employing a multi-focusing method. The multi-focusing method allows the gamma camera to adjust its focus based on the anatomical characteristics of individual patients, thereby enhancing source-tracking accuracy. The performance of the system was evaluated under these four different scenarios. The Euclidean distance and three-dimensional gamma analysis were used to evaluate tracking accuracy and dose distribution. The redesigned collimator demonstrated significant improvements (compared to the previous design) in the spatial resolution of the gamma camera, showing 34.21% and 23.46% enhancements in the horizontal and vertical profiles, respectively. These improvements in gamma camera resolution are crucial for enhancing the tracking system's accuracy. The experimental results demonstrated varying degrees of accuracy across different cases, reflecting the performance of the system under different conditions. The average Euclidean distance errors were Case 1 (327.30mm): 1.358mm; Case 2 (377.30mm): 1.731mm; Case 3 (427.30mm): 1.973mm; and Case 4 (multi-focusing): 1.527mm. The gamma pass rates for the four cases were:- Case 1: 86.39%; Case 2: 75.28%; Case 3: 72.22%; and Case 4: 81.67% (1mm/1%). For the 2mm/2% criterion, the gamma pass rates were 97.11, 94.72, 92.38, and 96.78% for Cases 1, 2, 3, and 4, respectively. Case 4 (multi-focusing) showed an improvement over Case 3, with a 22.6% reduction in the average Euclidean distance error and a 13.1% increase in the gamma pass rate (1mm/1%). These results demonstrate that the new 4D in vivo source tracking and treatment verification system for HDR brachytherapy is feasible and has potential clinical benefits.

Surgeon's perceptions and preferences in the management of idiopathic macular hole.

The management of idiopathic macular holes (iMH) has evolved over time with various modifications in surgical approach. The study aimed to survey the surgeons' preferences in the management of iMH in current times. Cross-sectional descriptive survey. A 12-item questionnaire addressing the key aspects of iMH management was sent, between October 2022 to November 2022, by personal correspondence to 104 vitreoretinal specialists, actively practicing and performing iMH surgeries at various institutes in India. The responses were gathered till January 2023 and analyzed as per appropriate statistical methods. Ninety-one retina specialists responded to the survey (response rate of 87.5%) with a median annual surgical load of 30 cases (range: 5-150). Most respondents had similar views on patient selection, combined phaco-vitrectomy, internal limiting membrane (ILM) staining, ILM peel initiation and propagation, tamponade, postoperative positioning, and prognostic factors. The preferred approach for peel initiation was "pinch and peel," but "scrape and peel" was equally recommended for beginners. Most respondents considered iMH >600 microns in size as large and used additional surgical maneuvers for large and failed cases such as ILM flap, large flap, macular detachment, platelet-rich plasma application, and amniotic membrane graft. The three most important visual prognostic factors were duration, preoperative vision, and MH size. The practice of surveyed surgeons performing iMH surgery was uniform in several aspects. There is a need to create consensus on the preferred ILM peel technique among trainee surgeons, revisit the iMH size classification, and standardize the surgical approach as per hole size and characteristics.

Beyond periodicity: tailoring Tamm resonances in plasmonic nanohole arrays for multimodal lasing

Abstract Extraordinary optical transmission (EOT) through metal nanohole arrays (NHAs) and Tamm plasmon (TP) states have been investigated in plasmonic devices since 1998 and 2007, respectively. Since their introduction, various potential applications for structures that support these phenomena have been reported, including plasmonic absorbers, lasing cavities, and narrowband filters. The performance of EOT- and TP-based devices is significantly influenced by the sizes and patterns of the holes in the NHA. While the effects of hole size and shape on EOT have been extensively studied, similar research on TP structures involving metal NHAs is still lacking. Particularly, the impact of gradually introducing randomness into the metal NHA on TP modes has yet to be explored. In this work, we modify the hole sizes and arrangements of the metal NHA and examine the effects on EOT and Tamm resonances. We investigate three scenarios: the bare metal NHA, a passive Tamm resonant cavity, and a Tamm plasmonic laser. We observe that multiple Tamm resonances appear as the periodicity of the holes increases. However, these resonances vanish when the hole arrangement shifts from a regular array to a pseudo-periodic random array, which is defined as a collection of holes placed randomly within a periodically repeating square unit cell. These multiple resonances can be attributed to the folding of dispersion lines in a periodically patterned TP cavity. The dispersion characteristics of the NHA array-based structures are calculated and analyzed to understand better the multiple resonances in the transmission and lasing emission patterns.

What gass did not say: how many ways to create a macular hole

Thanks to Dr. Gass' proposal for staging macular holes, we could have insights into the pathogenesis and progression of idiopathic macular holes back in the era without optical coherence tomography (OCT). This staging system is based on the foveal appearance, the size of the macular hole, and the presence or absence of vitreous separation as observed through biomicroscopy. According to the staging progression, anteroposterior traction from the posterior hyaloid plays a significant role in the development of a macular hole. Although most of Dr. Gass' descriptions remain relevant after the development of OCT, we have observed some cases of macular holes that do not fit into the Gass’ classification. The International Vitreomacular Traction Study (IVTS) Group has developed a new classification system based on OCT findings, such as macular hole size and the vitreomacular relationship. However, this system still considers partial or complete vitreomacular separation a necessary condition for the development of a macular hole. Interestingly, we have noticed that in some cases, there is no vitreomacular separation at the macular area, whereas in others, the macular hole develops only after posterior hyaloid detachment. These observations suggest that some macular holes might not develop through the classical route described by Dr. Gass. The traction force resulting in macular hole formation may be tangential, originating either from the undetached posterior hyaloid, the internal limiting membrane, or the epiretinal membrane. In this talk, we will explore aspects of the pathogenesis of idiopathic macular holes that Dr. Gass did not say.

Letter to the Editor Regarding "Effectiveness of Burr Hole Sizes on Midline Shift and Hematoma Thickness in the Treatment of Chronic Subdural Hematoma".

Letter to the Editor Regarding "Effectiveness of Burr Hole Sizes on Midline Shift and Hematoma Thickness in the Treatment of Chronic Subdural Hematoma".

Comprehensive Review on the Studies on Castellated Beam

The numerous studies on castellated beams, a kind of steel beam that is frequently employed in structural engineering due to its exceptional strength-to-weight ratio and aesthetic appeal, are examined in this thorough literature review. Standard Ibeams are split and reassembled to form web apertures in castellated beams, which preserve structural strength while using less material. Important subjects covered in the paper include the structural performance of castellated beams under bending, shearing, and axial loads, among other loading situations. Important design considerations are also covered, such as how hole size, shape, and placement affect beam efficiency. Research on castellated beams' buckling properties, fatigue durability, and failure modes is reviewed, as are methods for improving their design to strike a compromise between cost and performance. Furthermore, the paper highlights advancements in computational methods, particularly the use of software for finite element analysis (FEA), such as Abaqus, which has emerged as a crucial tool for simulating the complex behaviours of castellated beams. The significance of experimental studies in confirming analytical models and expanding our understanding of castellated beam behavior in real-world scenarios is also included in the review. In order to keep up with the latest developments in castellated beam design and technology, engineers and researchers can benefit greatly from consulting this survey of the literature.

Induced structure and its gradient design on energy absorption properties and failure behavior of aluminum/carbon fiber reinforced polypropylene super hybrid tube

AbstractThe metal/fiber super hybrid tube is a mixture of pure metal and carbon fiber structure, featuring both stable energy dissipation of the metal and good energy absorption efficiency of the composite, with greatly improved lightweight. However, the failure mode of the hybrid tube is unstable and prone to Eulerian buckling, which affects its energy absorption performance. In this work, aluminum alloy/carbon fiber reinforced polypropylene super hybrid tube (Al/CFPP super hybrid tube) have been obtained through the addition of an induced structures, which aims at reducing the maximum peak load generated during collision. The effects of induced grooves and holes structure (number of holes, diameter and row number) on the damage and energy absorption were discussed. The results showed that the initial peak load can be effectively reduced by adding an induction groove structure. When the number of induction holes is 4, the diameter is 5 mm, and the number of rows is 1, the initial peak load decreases by 14.06%, and the total energy absorption is basically unchanged. Additionally, the gradient design of the hole diameter and spacing significantly helped guide the gradual failure of the structure, with the initial peak load decreased by 21.98% and the total absorption energy increased by 20.26%.Highlights Super hybrid structures were developed to improve crashworthiness. The effect of induced grooves energy absorption was analyzed. The effect of hole size and quantity energy absorption were analyzed. A gradient design of hole size and spacing was proposed. The combined of the induction hole and trigger angle was demonstrated.

Microbial Contamination and Isolator Gloves: If It All Came Down to the Size of a Hole?

Isolators play a critical role in protecting both the product and the environment, as well as the personnel involved in pharmaceutical manufacturing, analytical procedures, and sterility testing. Gloves attached to the windows and doors of the isolator are designed to facilitate intervention, testing, and safety. However, due to their inherent characteristics and vulnerability to puncture or loss of integrity, they are recognized as a significant potential source of contamination. In addition to the possible pathways of contamination transfer, the size of glove holes plays a critical role in determining the risk of contamination. In this study, chlorosulphonated polyethylene (CSM) gloves were exposed to an aerosol containing Bacillus subtilis or Staphylococcus aureus This assessment aimed to ascertain the integrity of the gloves' seal. It was postulated that, below a certain aperture size, gloves used in isolator systems could establish an effective seal even if the external surface of the gloves exhibited modifications. Calibrated holes of different diameters (0.3, 0.5, 1, and 1.5 mm) were created using a femtosecond laser drilling technology. The holes were located on the tip of the middle finger. Based on the context of our study, passage of microorganisms through glove holes of a certain size does occur. Under the experimental conditions chosen, the cutoff for passage was determined to be a 0.5-mm hole, regardless of the microorganism evaluated. Although this study has some limitations, including the lack of a panel of microorganisms evaluated and the investigation of a single glove type called CSM, the high level of "worst case" challenge conditions provides compelling data to support our results. It would now be interesting to carry out studies at different production sites to assess their risk of contamination and relate this to their glove failure.

Design and Preparation of a Self-Inhaling Internal Cooling Grinding Wheel with a Leaf Order Arrangement Structure

Grinding wheels are important tools for precision machining. Traditional grinding wheels have issues such as high grinding forces and temperatures on the machined surface, and excessive use of grinding fluids often leads to significant waste. To solve such problems, this paper proposes a self-inhaling internal cooling structured grinding wheel with a leaf order arrangement based on laser cladding technology, by which the “air barrier effect” in grinding is avoided. In this study, the structure of the grinding wheel substrate, as well as the arrangement of abrasive grain clusters, were optimized. The internal flow field and grinding zone flow field of the grinding wheel were simulated using the computational fluid dynamics method. To ensure stable grinding performance, the effects of different cooling hole positions and sizes on fluid motion were revealed, and the influence of grinding wheel rotational speed and coolant pressure on outlet velocity were analyzed. The results show that uniform coolant outlet velocity distribution can be achieved via matching the grinding wheel’s rotational speed with the initial pressure of the cooling fluid inside the grinding wheel. This study further explored the fluid motion patterns in the grinding zone for four differently structured surfaces. The advantages of using leaf order theory to arrange abrasive clusters were verified. Additionally, orthogonal experiments and range analysis were conducted to study the laser cladding preparation process of grinding wheels. With the optimal process parameters, a self-inhaling internal cooling grinding wheel with a leaf order arrangement structure was fabricated.

Dielectric and free volume of Poly methyl methacrylate/silver nanoparticles- polyhydroxybutyrate nanocomposites (PMMA- AgNP/PHB): positron annihilation lifetime study

Abstract Solution casting technique was used successfully to prepare Poly methyl methacrylate/silver nanoparticles-polyhydroxybutyrate blend with different polyhydroxybutyrate (PHB) concentrations. FTIR results assure and confirm the good compatibility between the two polymers. X-ray results of the PHB/PMMA-AgNP blend show an increase in crystallinity with increasing PHB loading. A non-destructive Positron annihilation lifetime measurements were conducted at room temperature as a function of PHB concentration. Dielectric measurements were performed in the frequency range of 50 Hz to 50 MHz at RT. It was observed that O-Ps lifetime, τ3, O-Ps intensity, I3, free volume hole size, FV, and fractional free volume, FFV, were found to decrease with increasing PHB percentage. The dielectric constant ε/ showed a declined behaviour with increasing PHB content. The fabricated blend shows anomalous behaviour regarding the dielectric properties and free volume properties, assuming that blending PMMA with PHB alters the blend polarization behaviour in an external electric field.&amp;#xD;

Quantitative Risk Assessment of Hydrotreated Vegetable Oil at an Oil and Gas Company

Introduction: An oil and gas refinery operates various equipment with specific functions for different processes. Each piece of equipment has potential hazards that can damage the equipment and injure or kill workers. This study focuses on the hydrotreated vegetable oil (HVO) export facility from the jetty loading area at an oil and gas company that processes flammable liquid using various equipment. Methods: The HAZOP method determined the hazardous spots, and the probability of each equipment failure corresponding to the system was also determined using fault tree analysis (FTA). Furthermore, every event tree analysis (ETA) output probability was also determined. The probability and radius of pool fire varied for different leak hole scenarios. The final steps are individual risk per annum and potential loss of life to measure the risk level of the system. Results: Based on HAZOP deviation scenarios, every operating equipment can potentially cause a pool fire. In FTA, scenarios were developed based on different leakage hole sizes, ranging from 1-3 mm, 3-10 mm, 10-50 mm, 150 mm, and &gt;150 mm. The results indicated that leakage could occur across all operating equipment. Similarly, the ETA applied the same bore size scenarios. The consequence analysis yielded a worst-case outcome of pool fire and a best-case outcome of un-ignited fluid release. Subsequently, the pool fire output was modeled using ALOHA, which resulted in three heat flux zones: the red zone (10 kW/m²), the orange zone (5 kW/m²), and the yellow zone (2 kW/m²). Smaller leak holes had a higher probability but smaller pool fire radius. The initial risk of the export facility was unacceptable. Furthermore, insufficient safeguards contribute significantly to the resulting high-risk level. Two mitigations were implemented: adding safeguards and reducing worker hours. Conclusion: The final results showed that for every piece of equipment, the overall risk of the export facility became acceptable after mitigation..

Dynamic characteristics of micro-perforated complex beam structures

This paper discusses research concerning the fluctuating dynamic characteristics of various micro-beams featuring intricate designs and perforated surfaces across their entire operational faces. The complex beam structures consist of different types: folded beam, V-shaped beam, and crab-shaped beam with different boundary conditions: fixed-free, fixed-fixed for the simple single beam, and fixed-guided for the rest. The types of holes on the body of the beams are choice in square and circle-shaped for common. In addition, the methodology to determine the dynamic characteristics of the perforated beam is also proposed based on using FEM simulation software. The results show that the dynamic characteristics of the beam in which the holes are distributed depend on the size and shape of perforated holes. As the size or quantity of holes on the surface of the beam in perforated micro-beams grows, the equivalent stiffness drops noticeably. Consequently, the fundamental frequencies of the MEMS systems that include these micro-beams also diminish. The damping coefficient also reduces thanks to the occurrence of these holes. The maximum decrease in damping coefficient reaches 84% in the ideal case for the crab-shaped beam with square holes. These results can be used to optimize the MEMS structures in future research.