Optimal Flow Research Articles

Optimizing Microfluidic Channel Design with High-Performance Materials for Safe Neonatal Drug Delivery.

Designing the microfluidic channel for neonatal drug delivery requires proper considerations to enhance the efficiency and safety of drug substances when used in neonates. Thus, this research aims to evaluate high-performance materials and optimize the channel design by modeling and simulation using COMSOL multiphysics in order to deliver an optimum flow rate between 0. 3 and 1 mL/hr. Some of the materials used in the study included PDMS, glass, COC, PMMA, PC, TPE, and hydrogels, and the evaluation criterion involved biocompatibility, mechanical properties, chemical resistance, and ease of fabrication. The simulation was carried out in the COMSOL multiphysics platform and demonstrated the fog fluid behavior in different channel geometries, including laminar flow and turbulence. The study then used systematic changes in design parameters with the aim of establishing the best implementation models that can improve the efficiency and reliability of the drug delivery system. The comparison was based mostly on each material and its appropriateness in microfluidic usage, primarily in neonatal drug delivery. The biocompatibility of the developed materials was verified using the literature analysis and adherence to the ISO 10993 standard, thus providing safety for the use of neonatal devices. Tensile strength was included to check the strength of each material to withstand its operation conditions. Chemical resistance was also tested in order to determine the compatibility of the materials with various drugs, and the possibility of fabrication was also taken into consideration to identify appropriate materials that could be used in the rapid manufacturing of the product. The results we obtained show that PDMS, due to its flexibility and simplicity in simulation coupled with more efficient channel designs which have been extracted from COMSOL, present a feasible solution to neonatal drug delivery. The present comparative study serves as a guide on the choice of materials and design of microfluidic devices to help achieve safer and enhanced drug delivery systems suitable for the delicate reception of fragile neonates.

Exploring subaqueous bedforms and its relation to hydrodynamics in the Rio Grande Rise, Southwestern Atlantic

This study investigates the interplay between hydrodynamics, sediment dynamics, and topography in the Rio Grande Rise (RGR) area. It addresses bedforms found in five different regions, attributing their formation to the interaction between unconsolidated carbonatic substrate and bottom currents, particularly the M2 tidal flow, the primary lunar semidiurnal constituent. The bedforms are shaped by the interplay of the M2 tidal current and local topography, with the bottom mean flow also contributing to specific areas. Generally, bedforms are classified as subaqueous dunes/tidal banks. The environmental sectorization within the RGR, driven by variations in bottom velocities related to flow-topography interaction, delineates deposition and non-deposition areas. Bathymetric data reveal that bedforms are present in shallower, lower-flow energy zones, whereas FeMn crusts are located in more profound, higher-flow energy areas. They indicate that carbonate sediments are either being transported away from the crust regions or remobilized, leading to accumulation in the areas with bedforms. The flow velocity in FeMn crust areas is able to cause sediment bypassing, resulting in areas where deposition does not occur. Furthermore, these velocities exceed the optimal flow conditions for FeMn crust precipitation and could be eroding the previously formed FeMn crusts. These findings imply that FeMn crusts lie beneath the subaqueous dunes to some extent. This study highlights the complexity of the interaction of oceanic flow with the RGR substrate and its morphology, emphasizing the importance of local hydrodynamics and topography when analyzing these features.

Travel time prediction for an intelligent transportation system based on a data-driven feature selection method considering temporal correlation

Travel-time prediction is a critical component of Intelligent Transportation Systems (ITS), offering vital information for tasks such as accident detection, congestion management, and traffic flow optimisation. Accurate predictions are highly dependent on the selection of relevant features. In this study, a two-stage methodology is proposed which consists of two layers of Optimisation Algorithm and one Data-Driven method (OA2DD) to enhance the accuracy and efficiency of travel-time prediction. The first stage involves an offline process where interconnected optimisation algorithms are employed to identify the optimal set of features and determine the most effective machine learning model architecture. In the second stage, the real-time process utilises the optimised model to predict travel times using new data from previously unseen parts of the dataset. The proposed OA2DD method was applied to a case study on the M50 motorway in Dublin. Results show that OA2DD improves the convergence curve and reduces the number of selected features by up to 50%, leading to a 56% reduction in computational costs. Furthermore, using the selected features from OA2DD, reduced the prediction error by up to 29% compared to the full feature set and other feature selection methods, demonstrating the method's effectiveness and robustness.

Design, optimization, simulation, and implementation of a 3D printed soft robotic peristaltic pump

Abstract This study presents an innovative approach to fluidic pumping using soft robotics, designed to circulate fluid through soft conduits for delicate environments like blood streams where traditional peristaltic pumps may not be feasible. A novel soft robotic peristaltic pump is optimized and implemented, featuring 3D printed ring-shaped actuators and a PDMS pipe housing a Newtonian fluid. The design includes a three-stage actuator ring structure, actuated sequentially for peristaltic motion. A parametric finite element model predicts the required pressure, and the Mooney-Rivlin 5 Parameters hyper-elastic material model ensures accurate material properties. Optimization uses response surface analysis in Minitab and MATLAB Simulink Simscape simulations to achieve maximum flow rate with minimal power and pressure. Experimental validation confirms the simulations, achieving an optimal flow rate of 0.27 ml s−1 at a 450 ms cycle, with minor discrepancies due to friction and measurement errors. This study demonstrates the scalability of linearly sequenced soft squeeze actuators into an effective pump, validated by both simulation and experiments. Future applications include medical devices addressing deep venous thrombosis, with further research exploring control theory for optimization and comparing performance with conventional pumps to enhance practical applicability.

The Effect of O2 Flow Rate on Nanostructured TiO2 Thin Films Prepared by Reactive DC Magnetron Sputtering with OAD Technique

In this project, we explored how different oxygen flow rates influenced the creation of TiO2 nanostructures in thin films using magnetron sputtering preparation with oblique angle deposition (OAD) technique. The experiment involved oxygen flow rates of 20, 40, 60, 80 and 100 sccm along with a constant argon flow at 20 sccm. Morphological analysis by FE-SEM was performed to determine film thickness and deposition rate. In a subsequent stage, thin films thickness was confirmed to be 100 nm. After coating, specimens were annealed at 300°C for 2 h using various O2 flow rates. FE-SEM revealed morphological changes, GIXRD to explore crystal structures, and UV-Vis spectrophotometry to measure light transmittance. The results showed an optimal oxygen flow rate at 60 sccm, with annealed specimens exhibiting anatase structure and promising light transmittance of 73-83%.

Abstract 4119250: Partial versus Full ECMO Support in Combined Cardiogenic and Septic Shock – ELSO Registry Analysis

Background: There remains paucity of data on patient outcomes with combined cardiogenic and septic shock requiring veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support. While guidelines exist on target VA-ECMO flow in cardiogenic shock patients, optimal (partial versus full) flow in combined shock remains largely unknown. Methods: We queried the Extracorporeal Life Support Organization registry to identify patients in combined cardiogenic and septic shock supported with VA-ECMO between 2017 and 2022. Patients were categorized into either partial or full ECMO support based on ECMO flow at 24 hours indexed to body surface area. Partial support was defined as < 2.2 liters/m2 while full support was ≥2.2 liters/m2. Patients with other forms of mechanical circulatory support, VA-ECMO as bridge to advanced therapies or discharged on VA-ECMO were excluded from the analysis. Primary outcome of interest was survival to discharge. Baseline characteristics including center volumes and Charlson co-morbidity index were compared between survivors and non survivors. Predictors of mortality were identified using multivariable logistical regression model. Results: A total of 452 patients with combined shock supported with VA-ECMO were identified. Overall mortality was 63%. Patients that survived to discharge were younger (46.3 vs 53 years, p < 0.001) and had lower BMI (29.3 vs 31.1, p = 0.041), Charlson co-morbidity index (1.4 vs 2.0, p = 0.01) and rates of pre-ECMO cardiac arrest (28.7% vs 39.4%, p = 0.023). Survivors were also more likely to be at high [> 25 ECMO runs per year] volume centers compared to low [≤ 10 ECMO runs per year] volume centers (62.3% vs 20.4%, p = 0.04). Patients receiving full ECMO support had a higher likelihood of survival to discharge than partial support (42.6% vs 33.8%, p = 0.063), although it did not reach statistical significance. [Table 1] Indexed VA-ECMO flow at 24 hours was also associated with improved outcomes when assessed as continuous variable. [ Figure 1] Advanced age [aOR 1.02, 95% CI 1.01-1.04, p < 0.001], pre-ECMO cardiac arrest [aOR 1.71, 95% CI 1.11-2.65, p = 0.016] and baseline Charlson co-morbidity index [aOR 1.13, 95% CI 1.01-1.28, p = 0.043] were all associated with increased mortality after adjustment for baseline differences. Conclusion: Mortality among patients requiring VA-ECMO for combined cardiogenic and septic shock is high. Full circulatory support may be associated with improved survival in this cohort.

ESTIMATION OF THE CLEANING TIME OF THE BOTTOM-HOLE ZONE OF WELLS IN CONDITIONS OF UNCERTAINTY

The aim of the work is to analyze changes in the maximum optimal flow rates of wells operating various groups of productive formations of the Volga-Ural oil and gas province under conditions of uncertainty of geological and field data. The relevance of the work is due to the deterioration of the structure of residual oil reserves and the need for the most efficient extraction of liquid hydrocarbon resources, optimization of design methods for various treatments of the bottomhole formation zone. Using geological and statistical modeling systems, the timing of cleaning the bottomhole zones of wells from drilling products was determined at the time they reached their maximum optimal flow rate in conditions of deposits confined to various stratigraphic horizons, and appropriate models of changes in productivity coefficients were constructed. The factors influencing the recovery time of the real properties of the reservoir at the point of opening it by the well, which, among other things, determines the profitability of the process of selecting residual oil reserves, have been established. Among them, the most relevant and necessary for the implementation of an integrated approach to computer support procedures for the development of oil fields are the productivity of wells, fracturing of formations, their proximity to a particular tectonic-stratigraphic complex, geological, physical and physico-chemical properties of formations and their saturating fluids. For the deposits of the Famensk tier of deposits of the Volga-Ural oil and gas province, a multiple decrease in the time of removal of reaction products after hydrochloric acid exposure at objects with low fracturing has been established. At the same time, additional processing of the bottomhole formation zone within areas with high drilling density does not affect the total cleaning time of the bottomhole zone of wells. Stimulation of the removal of drilling mud filtrate and additional products of formation reactions by injection of hydrochloric acid compositions under certain conditions can lead to a decrease in the actual productivity of wells due to the introduction of less developed and dead-end cracks into the drainage process. The existence of the specifics of the procedure for cleaning the bottomhole formation zone depending on the geological and physical parameters of productive formations is substantiated and various patterns of changes in the productivity coefficient depending on the time of wells reaching the maximum optimal flow rate are revealed. The results obtained make it possible to make informed technological decisions to improve the efficiency of oil production, including in conditions of uncertainty, which may be caused by the lack of the necessary volume of hydrodynamic studies of wells.

An Optimized Strategy for the Integration of Photovoltaic Systems and Electric Vehicles into the Real Distribution Grid

The increasing spread of photovoltaic systems for private households (PVs) and electric vehicles (EVs) in order to reduce carbon emissions significantly impacts operation conditions in existing distribution networks. Variable and unpredictable PVs can stress distribution network operation, mainly manifested in voltage violations during the day. On the other hand, variable loads such as EV chargers which have battery storage in their configuration have the ability of storying a surplus energy and, if it is necessary, support a distribution network with energy, commonly known as vehicle-to-grid concept (V2G), to help voltage stability network enhancement. This paper proposes an optimal power flow (OPF)-based model for EV charging to minimize power exchange between the superior-10 kV grid and the observed distribution feeder. The optimization procedure is realized using the co-simulation approach that connects power flow analysis software and optimization method. Three different scenarios are observed and analysed. The first scenario is referred to as a base case without optimization. The second and third scenarios include optimal EV charging and discharging patterns under different constraints. To test the optimization model, a 90-bus unbalanced distribution feeder modelled based on real-life examples is used. The obtained results suggest that this optimization model does not only significantly reduce the power exchange between an external network and the distribution feeder but also improves voltage stability and demand curve in the distribution feeder.

STCO: Enhancing Training Efficiency via Structured Sparse Tensor Compilation Optimization

Network sparsification serves as an effective technique to accelerate Deep Neural Network (DNN) inference. However, existing sparsification techniques often rely on structured sparsity, which yields limited benefits. This is primarily due to the significant memory and computational overhead introduced by numerous sparse storage formats during address generation and gradient updates. Additionally, many of these solutions are tailored solely for the inference phase, neglecting the crucial training phase. In this article, we introduce STCO, a novel Sparse Tensor Compilation Optimization technique that significantly enhances training efficiency through structured sparse tensor compilation. Central to STCO is the Tensorization-aware Index Entity (TIE) format, which effectively represents structured sparse tensors by eliminating redundant indices and minimizing storage overhead. The TIE format plays a pivotal role in the Address-carry flow (AC flow) pass, which optimizes the data layout at the computational graph level. This pass leverages the TIE format to enhance the efficiency of tensor representations, enabling more compact and efficient sparse tensor storage. Meanwhile, a shape inference pass utilizes the AC flow to derive optimized tensor shapes, further refining the performance of sparse tensor operations. Moreover, the Address-Carry TIE Flow dynamically tracks nonzero addresses, extending the benefits of sparse optimization to both forward and backward propagation. This seamless integration into the training pipeline enables a smooth transition to sparse tensor compilation without significant modifications to existing codebases. To further boost training performance, we implement an operator-level AC flow optimization pass tailored for structured sparse tensors. This pass generates efficient addresses, ensuring minimal computational overhead during sparse tensor operations. The flexibility of STCO allows it to be efficiently integrated into various frameworks or compilers, providing a robust solution for enhancing training efficiency with structured sparse tensors. Experiments demonstrated that STCO achieved impressive speedups of 3.64×, 5.43×, 4.89×, and 3.91× when compared to state-of-the-art sparse formats on VGG16, ResNet-18, MobileNetV1, and MobileNetV2, respectively. These findings underscore the efficiency and superiority of our proposed approach in leveraging unstructured sparsity for DNN inference acceleration.

Calculation model of enjoyment of dust particles by swirking flow in gas flowes

An analysis of the reasons for the formation of deposits in the flue ducts of aspiration systems was carried out. Problems have been noted in removing deposits with compressed air. The purpose of the work is to solve the problems of aspiration systems and reduce the formation of dust deposits in gas ducts. This is possible due to the swirling of the compressed air flow when purging the gas duct. Despite significant pressure losses when organizing flow swirl, compressed air consumption is reduced by 20–40%. A computational model of the entrainment of dust particles by a swirling flow in gas ducts is presented. To describe the physical model of the movement of a dust particle in a swirling gas flow flowing in a gas duct with a circular cross-section, polar coordinates are used. Dependencies have been deter-mined to determine the value of the average axial velocity of the swirling flow required to move a particle along the gas duct. A diagram of the coordinate axes and forces acting on the particle is presented. The forces acting on the dust particle and its connections with the inner surface of the flue are replaced by the reaction of the flue wall. By decomposing the wall reaction into tangential and normal components, differential equations were obtained that describe the motion of the particle. The dust particle is significantly influenced by the forces of resistance to flow around the gas flow Fμ, the friction force on the wall of the gas duct Ffr, the weight of the particle P, the normal reaction of the wall of the gas duct N. Analysis of the fractional composition of various dusts contained in gases aspirated from the equipment of the metallurgical industry and the production of electrode materials showed that For these dusts, the optimal flow is a weak swirl of intensity W*= 0.5–0.8. This swirling intensity can be achieved by introducing a flow of compressed air when blowing at an angle of 36–48°.

What are the minimal criteria of goal-directed perfusion (GDP) in adult cardiac surgery?

Introduction: Nowadays, many cardiac surgery teams are adopting the goal-directed perfusion (GDP) strategy in their practice to maintain optimal perfusion during cardiac surgeries and improve patient outcomes. Furthermore, it plays an indispensable role as a quality control tool to monitor both perfusionists’ practice and equipment (in addition to disposables used in the surgery. Objectives: To identify the role and the elements of GDP that facilitate better surgical outcomes. In addition, to compare between GDP and the traditional conventional perfusion strategy (CP) in terms of perfusion adequacy and surgical outcomes. Finally, to recognize challenges that may prevent the effective application of GDP and finding possible applicable solutions. Methods: A systematic literature review was conducted from three different databases PubMed, SpringerLink, and ScienceDirect. The selected studies were in English from the USA and Europe with a time frame starting from 2005. Results: The findings highlight the crucial role of the GDP strategy in protecting and preserving end-organ function after on-bypass cardiac surgery procedures. Furthermore, a clear understanding of the GDP implementation component and criteria was obtained. Alternatively, a satisfactory GDP level can be achieved by the optimal utilization of available resources. Discussion: Dismantling the GDP strategy into practically recognized components to ease the implementation at different levels of perfusion practice. Conclusion: The GDP approach involves the intensive monitoring of respiratory-related parameters to enhance surgical outcomes. The process includes blood preservation, optimal flow and intraoperative parameters management. Monitoring is the key element of GDP, which can be applied by using the sophisticated technology or the proper use of existing resources to develop protocols within the international guidelines and recommendations. Achieving an optimal perfusion requires concerted efforts of organizational, safety, and practical measurements.

PCA-Kriging-Based Oscillating Jet Actuator Optimization and Wing Separation Flow Control

In order to improve the separation control effect of an oscillating jet, the external flow field of the actuators and the wing wake are obtained via hot-wire measurements to optimize the actuator and achieve wing separation flow control. The optimization objectives are to improve the sweeping uniformity and range of the jet. In the present study, the PCA method is used for the modal decomposition of the velocity distribution. The modal-based actuator evaluation parameters are proposed, and the kriging surrogate models of the modal coefficients (principal components) on the actuator parameters are established. The multi-objective genetic algorithm was utilized to complete the optimization of the actuator, and the effect of flow separation control on the wing was verified. The results show that three patterns exist in the time-averaged velocity distribution of the external flow field: unimodal, broad and bimodal, from unimodal to bimodal, the degree of the jet sweeping uniformity gradually decreases, and the sweeping range gradually increases. The pattern of the velocity distribution modals affects the degree of jet sweeping uniformity, while the distance of the modal peaks affects the jet sweeping range. The two evaluation parameters are negatively correlated: insufficient sweeping range or poor sweeping uniformity of the jet are not conducive to wing separation flow control, and the two must be coordinated to achieve the optimal control effect.

Numerical modeling and parameter optimization of the combustion chamber in a tower-type zinc refining furnace

With the implementation of “coal-to-gas” projects, the tower-type zinc refining furnace (TZRF) has encountered a mismatch between high-calorific value fuel and the primary combustion system. To address this issue, this study conducted a full-scale modeling of the combustion and heat transfer processes in the TZRF combustion chamber using computational fluid dynamics. An in-depth analysis and condition diagnosis of the TZRF were performed, elucidating the key causes of deteriorating furnace conditions, reduced efficiency, and decreased production capacity following fuel replacement. This study shows that the flow ratios of gas outlets are unevenly distributed, leading to poor mixing of natural gas and air, resulting in an uneven temperature field in the TZRF. A low-temperature zone is clearly observed below the second-layer burner, where significant accumulation of natural gas fails to combust completely. Although tilting the first-layer burner upward slightly enhances the overall heat transfer performance of the tray, it detrimentally affects the overall combustion of natural gas in the TZRF. The deployment of third-layer air outlets substantially eliminates low-temperature zones, expands the range of high-temperature zones, and significantly improves the furnace condition. The optimal flow ratio of the third-layer air outlets is 29.57 %.

Multi-Objective Optimal Power Flow Analysis Incorporating Renewable Energy Sources and FACTS Devices Using Non-Dominated Sorting Kepler Optimization Algorithm

In the rapidly evolving landscape of electrical power systems, optimal power flow (OPF) has become a key factor for efficient energy management, especially with the expanding integration of renewable energy sources (RESs) and Flexible AC Transmission System (FACTS) devices. These elements introduce significant challenges in managing OPF in power grids. Their inherent variability and complexity demand advanced optimization methods to determine the optimal settings that maintain efficient and stable power system operation. This paper introduces a multi-objective version of the Kepler optimization algorithm (KOA) based on the non-dominated sorting (NS) principle referred to as NSKOA to deal with the optimal power flow (OPF) optimization in the IEEE 57-bus power system. The methodology incorporates RES integration alongside multiple types of FACTS devices. The model offers flexibility in determining the size and optimal location of the static var compensator (SVC) and thyristor-controlled series capacitor (TCSC), considering the associated investment costs. Further enhancements were observed when combining the integration of FACTS devices and RESs to the network, achieving a reduction of 6.49% of power production cost and 1.31% from the total cost when considering their investment cost. Moreover, there is a reduction of 9.05% in real power losses (RPLs) and 69.5% in voltage deviations (TVD), while enhancing the voltage stability index (VSI) by approximately 26.80%. In addition to network performance improvement, emissions are reduced by 22.76%. Through extensive simulations and comparative analyses, the findings illustrate that the proposed approach effectively enhances system performance across a variety of operational conditions. The results underscore the significance of employing advanced techniques in modern power systems enhance overall grid resilience and stability.

Application of Nano Bubble Aeration Technology in Domestic Wastewater Treatment: Optimization of Gas Flow and Reaction Time

Nano bubble aeration is an emerging technology with significant potential in wastewater treatment, particularly for removing suspended solids and organic matter. This study investigates the application of nano bubble aeration in the treatment of domestic wastewater, focusing on the reduction of chemical oxygen demand (COD) and total suspended solids (TSS). Nano bubbles, with diameters ranging from tens of nanometers to a few micrometers, exhibit slower rising velocities and prolonged stability in water due to their negatively charged surfaces. Various nano bubble air flow rates were tested over 90-minute intervals to determine the optimal treatment conditions. The results indicate that a flow rate of 2 liters per minute achieves the highest treatment efficiency, reducing COD by 84.73% and TSS by 77.51%. Increasing the flow rate beyond this level showed minimal improvement, demonstrating that 2 liters per minute is the optimal flow rate for efficient wastewater treatment using nano bubble aeration. This research highlights the advantages of nano bubble technology in enhancing the treatment efficiency of suspended solids and organic matter in wastewater.

Prediction and optimisation of solidification structure growth and transformation behaviour in microalloy chamfered continuous casting slab

The solidification structure of complex chamfered slabs of microalloyed steel was analysed and controlled. A computational model of solidified structures was applied and the model was verified. The research results show that there are differences in the solidification structure inside the slab. The slab successively produces fine-grained areas, large-size columnar grain areas, CET (columnar to equiaxed grain transition), and equiaxed grain areas. The effects of different carbon contents on the solidification structure were analysed. As the c content decreases from 0.23% to 0.20%, the tip growth fitting coefficient a3 increases from 4.077172e-06 to 5.403274e-06, which increases the grain growth rate. Considering the different sensitivities of grain growth in the lateral direction, a lateral zoning water supply strategy is used to flexibly control the uniformity of grain growth. By simulating different water flow ratios in the corners and centre areas, the optimal nozzle water flow density ratio is 0.840. Superheat can effectively control grain distribution. The proportion of central equiaxed grains increases with decreasing superheat. The study found that the proportion of equiaxed grains has different sensitivities affected by different degrees of superheat. The superheat degree ranges of strong sensitivity and weak sensitivity were obtained. In the production practice of superheat adjustment to control particle distribution, the adjustment effect is better within the strong sensitivity range.

Experimental and numerical investigations of liquid cooling plates for pouch lithium-ion batteries considering non-uniform heat generation

Ensuring the thermal safety of lithium-ion batteries requires efficient and reliable thermal management systems. However, the non-uniform heat generation of lithium-ion batteries results in uneven temperature distribution, which complicates the comprehension of the flow pattern design and operating parameter optimization in liquid-based battery thermal management, especially under extreme conditions. This study evaluates the thermal management performance of four classic liquid cooling plate designs for pouch batteries by considering their non-uniform heat generation through the electrochemical-thermal coupled model. Through experiment and numerical simulation, the optimal flow pattern is identified. Subsequently, the capability of the thermal management system, utilizing the best flow design, is further assessed under varying operating conditions. The results indicate that while a higher flow rate marginally enhances cooling, the coolant inlet temperature exerts a more substantial impact on the cooling performance. In addition, the recommended parameter settings for cell-level liquid cooling systems are outlined under extreme conditions. With a 5 C discharge rate and an initial temperature of 35 °C, the recommended coolant temperature range and coolant flow rate range are 20–30 °C and 60–100 mL min−1, respectively. As a typical example of computer-aided engineering, this study reveals the impact of battery non-uniform heat generation on battery temperature performance and provides a critical reference for the optimization of liquid-based battery thermal management systems.

L-Shaped Scapular and Parascapular Combined Flap forReconstruction of a Large Surface Defect After SarcomaResection Using ICG Angiography: A Case Seriesof6 Patients.

Soft tissue sarcomas (STS) pose challenges in management due to large defects following wide resection. Reconstructive options are often limited, especially in patients with large circular defects below the gluteal region. This article addresses the question of how to effectively reconstruct such defects while minimizing donor-site morbidity. We present our experience with using an L-shaped combined scapular and parascapular flap after STS resection, highlighting the novelty of employing indocyanine green (ICG) angiography to ensure optimal blood flow and surgical safety. We retrospectively reviewed patients who underwent STS resection and immediate reconstruction using an L-shaped scapular and parascapular combined flap between October 2022 and April 2024. The feasibility of the procedure was assessed by analyzing the patient demographics, tumor characteristics, defect and flap sizes, operative time, and postoperative outcomes, including donor-site complications and shoulder function. Six patients underwent reconstruction using an L-shaped combined flap with no donor-site complications or significant shoulder dysfunction. The average sizes were 15.7 × 13.7 cm for the defect, 20 × 7 cm for the scapular flap, and 23 × 7.3 cm for the parascapular flap. The average operative time was 7 h and 9 min. The average follow-up period was 10.2 months. Except for one case of partial flap necrosis, all flaps survived completely, highlighting the reliability of the procedure. L-shaped combined scapular and parascapular flaps are promising reconstructive techniques for large surface defects after STS resection with low donor-site morbidity and preservation of shoulder function. The novel application of these flaps for large circular defects below the gluteal region, combined with the use of ICG angiography to ensure flap viability and enhance surgical safety, are key contributions of this study.

THE TECHNIQUES OF ESTABLISHING RAPPORT BETWEEN HEALTHCARE PROFESSIONALS AND PATIENTS IN THE MATERNITY AMBULANCE

The study presents communication techniques used in a specific area of medical care, namely in obstetric care. Adequate communication is crucial in the relationship between the midwife and the expectant mother, as it facilitates optimal information flow, understanding, and the development of mutual trust between the parties. By applying effective communication techniques, the midwife can clearly and comprehensibly convey information, respond to questions, and emotionally support the laboring woman. This, in turn, can help the expectant mother understand the process of labor and make informed decisions. Empathy and attention towards the expectant mother can also be expressed through communication. Research on the communication between midwives and expectant mothers (Rijnders et al. 2008; Rowe et al. 2002) has found that the quality of communication with healthcare professionals significantly influences patients’ satisfaction (Dahlberg et al. 2016). In my research, after analyzing transcripts of recorded audio from the maternity ambulance, I summarize the communication techniques employed by midwives in establishing a connection with expectant mothers. Understanding the communication techniques used by midwives can help improve communication between the parties and make the support of expectant mothers more effective.

Flow channel simulation and optimization design of pervaporation membrane pool based on heat-mass-flow coupling

Flow channel simulation and optimization design of pervaporation membrane pool based on heat-mass-flow coupling