Port Size Research Articles

Artificial intelligence-driven analysis of dynamic melting in open shell-and-tube latent-heat storage: Effects of PCM inlet pressure, port geometry, and positioning

This numerical study explores dynamic melting as an enhancement strategy to improve heat transfer in thermal energy storage (TES) systems utilizing phase change materials (PCM) with openings. Optimizing such systems is crucial for advancing renewable energy storage and integration. A 3D model simulates RT35 PCM flowing through a shell-and-tube heat exchanger annulus. The effects of varying PCM inlet slot diameter (2.5–7.5 mm), inlet pressure (1–40 Pa), and inlet/outlet port positioning on melting fraction and temperature distributions are computationally evaluated. Results show that increasing slot diameter from 2.5 mm to 7.5 mm reduces melting time by 13.6 % (from 550 to 475 min). Raising inlet pressure from 10 Pa to 40 Pa cuts melting time by 43.8 % (from 400 to 225 min). However, varying inlet/outlet port positioning has negligible impact. Larger slot diameters and higher pressures produce more homogeneous melting across the radial width. A neural network approach revealed that port diameters around 5.5 mm maximized melting volume fraction at early stages, while increasing port size accelerated melting in later stages. This study provides quantitative data demonstrating that optimizing dynamic melting parameters through the annulus can substantially enhance heat transfer in open PCM-based TES systems. The novelty lies in systematically evaluating the effects of these design parameters on melting behavior and employing artificial intelligence to further analyze parameter interactions.

Factors influencing the adoption of circular economy practices in polish seaports: an analysis of determinants and challenges

The purpose of the article is to fill the research gap in identifying and prioritizing the factors that determine the choice of a port for handling circular supply chains (CSC). To this end, Polish seaports handling CSC cargo with an average turnover of at least 100,000 tons in the last 10 years were analyzed. The authors analyzed CSC cargo occurring in seaports, in two stages, both in terms of quantity and quality. The first stage involved an analysis of the literature and the European Commission’s programs on the development of the Circular Economy (CE), followed by an analysis of the relationship between the size of the port, measured by the average volume of cargo handled at the studied port, and the average share of CSC cargo in total cargo handling. On the other hand, in the second stage, based on face-to-face interviews, the factors that determine the choice of a particular port for handling CSC cargo were extracted. The study revealed a significant relationship between port size and the share of CSC cargo in total cargo handling. Furthermore, the research identified and prioritized key factors influencing the choice of ports for CSC, providing valuable insights for port authorities and policymakers. These findings can serve as a foundation for further academic research aimed at optimizing port operations within circular supply chains and advancing the theoretical framework of circular economy logistics. Port authorities and businesses can leverage these insights to enhance strategic decision-making, improve operational efficiency, and strengthen their competitive advantage in the circular economy landscape.

Numerical investigation on scroll compressor with intermediate discharge valve for VRF annual performance promotion

Over-compression of scroll compressor in variable refrigerant flow (VRF) system is a common problem in improving system efficiency because it operates in part load conditions for most of the year. By introducing intermediate discharge valves (IDVs) to allow gas bypass from compression chamber to discharge side during compression process, the over-compression loss can be eliminated. In this study, the characteristics of compression process in IDV compressor are analysed and the effects of IDV port location and port size on compressor efficiency are discussed based on the validated high fidelity scroll compressor model. It is found that the IDVs could be able to adjust gas bypass process in different compression ratio conditions and maintain high efficiency over wider compression ratio range than that of non-IDV compressor. In addition, the VRF system model is integrated to verify the system performance improvement by IDV compressor. It is found that VRF system performance is significantly improved in cooling conditions with the IEER enhanced by 23.9 %, while limited improvement is obtained in heating conditions as the operating compression ratios are relatively higher.

Construction of virtual airway model to assist surgical correction of velopharyngeal insufficiency with posterior pharyngeal flap

ObjectivePosterior pharyngeal flap (PPF) is one of the most common surgical technique to correct velopharyngeal insufficiency(VPI), during which controlling the sizes of the lateral pharyngeal ports(LPP) is the key to outcomes. One innovative procedure was developed to well control the size of LPP. Materials and methods40 patients with repaired cleft palate were collected from June 2022 to August 2023. All patients were diagnosed with VPI, and treated with modified PPF surgery. For each patient, upper airway model was reconstructed, and the virtual airway model of PPF was designed. The nasal valve area was measured as it was considered to be the narrowest part of the upper airway. The upper airway resistances under different sizes of LPP was predicted through computational fluid dynamics analysis. The minimum size of each lateral pharyngeal port without obviously increase of upper airway resistance was calculated through effect of lateral pharyngeal ports’ size on upper airway resistance. Postoperative follow-up was 6–18 months, including speech outcome and respiration outcome. Resting soft palate length (RVL), effective working length of soft palate (EWL) and angle of soft palate elevation (AVL) were measured and compared according to the lateral cephalometric radiograph. ResultsThere was a linear relationship between the threshold value and nasal valve (R = 0.62). Among the forty patients, the average size of nasal valve was 47.81 mm2, the average size of the threshold value of LPP was 31.63mm2. The proportion of velopharyngeal closure competence after surgery was 95 %. Compared with the preoperative measurements, there were significantly increase of RVL, EWL and AVL (P < 0.05). There were significantly difference in the nasal obstruction symptom evaluation score in long-term follow-up compared to short-term follow-up (P < 0.05), and no one needed flap revision. There was no significant difference in nasal respiration and nasal resistance before and after surgery (P > 0.05). ConclusionWith the help of computer fluid dynamics analysis, it is possible to predict the threshold size of lateral pharyngeal port without obviously increasing upper airway resistance and reduce the risk of suffering from airway obstruction for patients undergoing PPF surgery.

Vitrectomy for cases of diabetic retinopathy.

Microvascular complications of diabetic retinopathy (DR) may require surgical intervention in the form of vitrectomy. Since its inception, diabetic vitrectomy has evolved with introduction of better instruments, newer techniques, and smaller port sizes. Common indications for diabetic vitrectomy include nonresolving vitreous hemorrhage, tractional retinal detachment, epiretinal membrane, progression of fibrovascular membranes despite laser therapy, recalcitrant diabetic macular edema, and neovascular glaucoma. Preoperative systemic stabilization is essential prior to planning surgery. Surgical techniques commonly used in diabetic vitrectomy are segmentation, delamination, and rarely en-bloc dissection. Modification in surgical techniques such as chandelier-assisted bimanual dissection and pharmacological adjuvants improve surgical outcomes in these patients. Prognosis in these patients could be improved with early intervention. Studies evaluating the outcome of vitrectomy in patients with early proliferative DR are required to understand the appropriate time of intervention in patients. Treatment aimed at arresting the progression of DR and gene therapy are avenues that need further evaluation. The following review will focus on covering the epidemiology of DR, indications of vitrectomy, preoperative considerations, surgical procedures of diabetic vitrectomy, methods of membrane dissection, pharmacological adjuvants to vitrectomy, outcomes of diabetic vitrectomy, and future directions of diabetic vitrectomy.

Factors Influencing Greenhouse Gas Reduction Measures in European Ports: Implications for Sustainable Investing

European Union cargo and container ports are under pressure to reduce GHG emissions and achieve carbon neutrality by 2050, as mandated by the European Commission. The pace of progress varies among ports. This study examined the characteristics influencing GHG reduction measures in European cargo and container ports and their implications for sustainable investing. The methods used in this study, such as linear regression models to analyze predictive variables, can be applied in sustainable investing to assess which factors most strongly predict a company’s environmental, social, and governance performance. Using linear regression models to analyze data from the 33 busiest European ports, we identified five predictive variables: port size, cargo mix, surrounding population density, access to the sea, and the economic wealth of the host country. Our findings revealed that the port size significantly correlates with the adoption of measures to reduce scope 1, 2, and 3 emissions. This study underscores the importance of contextual and operational factors in evaluating sustainability efforts across sectors. The results contribute to drawing parallels with the field of sustainable investing within finance. This offers valuable insights for sustainable investing, emphasizing the importance of considering various contextual and operational factors when evaluating the sustainability efforts of entities in different sectors.

Experimental and numerical simulation research on the transport process of bubble clusters in aeration system

Improving gas-liquid mass transfer efficiency in aeration systems contributes to energy savings, cost reduction, and enhanced efficiency in wastewater treatment. However, due to the complex nonlinear interactions among bubbles in turbulence, understanding the transport mechanisms of non-uniform bubble clusters in turbulence remains unclear. This study employs a combined approach of experimental research and numerical simulations to investigate the shape, diameter distribution, trajectory, and velocity of bubbles under different aeration port sizes and flow rates. The diameter distribution of bubble clusters exhibits a bimodal distribution. Bubble trajectories during ascent mainly exhibit two types of motion patterns: “Z” shaped and linear. Increasing aeration port size and flow rate both lead to an increase in the maximum bubble diameter. Higher initial flow rates and smaller port sizes induce greater lateral velocity fluctuations in bubbles. The proposed numerical simulation method serves as a reference for simulating the transport of non-uniform bubble clusters.

Design and performance analysis of asynchronous network on chip for streaming data transmission on FPGA

The majority of the system on chip (SoC) uses the network on chip (NoC) as routing ports for data transfer from node-to-node with minimal power consumption and low latency and high throughput. This paper concentrates on the ability to model the asynchronous NoCs on the asynchronous circuits on field programmable gate arrays (FPGAs). A 3×3 NoC and its universal asynchronous receiver transmitter (UART) protocol is designed and its simulation of the Verilog hardware description language (VHDL) code is done and tested on the Artix-7 FPGA kit, the testing processes in done using the Chipscope tool. In order to meet target requirements in terms of power consumption and latency, the label switching (LS) technique is used as routing. The proposed LS-NoC with level-encoded dual-rail (LEDR) encoding technique provides throughput by registering the packet between the different routers and it helps to improve throughput and speed. The effectiveness of the data transfer is measured and analyzed through a synthesis summary in terms of lookup table’s (LUT’s), slice registers, flip flops’s (FF’s), latency, and packet delivery ratio (PDR) for the traffic pattern generator. The proposed NoC is designed for 8×8 and each port size is 21 bits including ID’s of source and destination routers. The results can be justified by following results: improvement of LUTs is about 12%, flip-flops are 7%, improvement of throughput is 23% and delay is reduced by 26%.

The Importance of Dimensional Traceability in Microfluidic Systems

Dimensional measurements are fundamental in microfluidic device manufacturing and performance. The main focus of this study is the measurement of the connection port sizes in microfluidic devices and components and, accordingly, the possible existence of fluid leaks determined using the flow rate error. The sizes associated with three different microfluidic systems were determined using laser interferometry and through an optical measuring instrument, with metrological traceability to national length standards. It was possible to infer the method with the greatest accuracy and lowest measurement uncertainty for characterizing this kind of system. In conclusion, the results of this work directly address the current lack of dimensions measuring methods of microfluidic components by providing a comprehensive comparison of different protocols, ultimately suggesting a preferred option for immediate application within the microfluidic industry.

Analysis of the interactive effects of scavenge parameters on spark ignition two-stroke diesel engines

The scavenging efficiency of a two-stroke diesel engine affects the formation of the mixture in the engine cylinder, which in turn affects the engine’s performance. A one-dimensional simulation model of a two-stroke diesel engine is established using GT-POWER, and the model with original experimental data is calibrated as boundary conditions. Firstly, the influence of crankcase compression ratio on engine performance of the two-stroke engine was investigated to obtain an appropriate crankcase compression ratio; Then, based on the optimization index of scavenging efficiency, the optimal combination of engine air port structure and timing is obtained through orthogonal optimization calculation method. To achieve higher scavenging efficiency, when the phase of the air port remains unchanged, a scavenging port width ratio of 1.0 and an exhaust port width ratio of 0.8 can achieve a scavenging efficiency of 97.2%; When the air port size remains unchanged, the engine scavenging efficiency reaches 96.44% when the scavenging port timing is 123° CA and the exhaust port timing is 89° CA.

Pebble flow in the HTR-PM reactor core by GPU-DEM simulation: Effect of friction

The high-temperature gas-cooled reactor (HTGR) with spherical fuel elements contains complex pebble flow. The flow behavior of pebbles is influenced by various factors, such as pebble density, friction coefficient, wall structure, and discharge port size. Using a GPU-DEM numerical model, the effects of the friction coefficient on the cyclic loading and unloading of pebbles in the full-scale HTR-PM are studied. Numerical simulations with up to 420,000 spherical pebbles are conducted. Four sets of friction coefficient values are determined for comparative analysis based on experimental measurements. Discharging speed, residence time, stress, porosity, and velocity distribution are quantitatively analyzed. In addition, a comparison with the CT-PFD experiment is carried out to validate the numerical model. The results show that near-wall retention phenomena are observed in the reactor core only when using large friction coefficients. However, using friction coefficient values closer to the measured experimental values, the pebble bed in HTR-PM exhibited good flow characteristics. Furthermore, the friction coefficient also influences the porosity and velocity distribution of the pebble bed, with lower friction coefficients resulting in lower overall stress in the bed. The discharge outlet's influence varies with different friction coefficient values. In summary, this study demonstrates that the value of the friction coefficient has a complex influence on the pebble flow in HTR-PM, which provides important insights for future numerical and experimental studies in this field.

Camera sheath with transformable head for minimally invasive surgical instruments

Introduction This paper presents a camera sheath that can be assembled to various minimally invasive surgical instruments and provide the localized view of the instrument tip. Material and methods The advanced transformable head structure (ATHS) that overcomes the trade-off between the camera resolution and the instrument size is designed for the sheath. Design solutions to maintain the alignment between the camera’s line of sight and the instrument tip direction during the transformation of the ATHS are derived and applied to the prototype of the sheath. Results The design solution ensured proper alignment between the line of sight and the tip direction. The prototype was used with the curved micro-debrider blades in simulated functional endoscopic sinus surgery (FESS). Deep regions of the sinus that were not observable with the conventional endoscopes was accessed and observed using the prototype. Conclusions The presented camera sheath allows the delivery of the instrument and camera to the surgical site with minimal increase in port size. It may be applied to various surgeries to reduce invasiveness and provide additional visual information to the surgeons.

Changes in efficiency and physical size of container ports: An integration of genetic matching and stochastic data envelopment analysis

Benchmarking container ports of different physical sizes and figuring out the relationship between size and efficiency is complex due to the heterogeneous environment. In dealing with heterogeneity, the selection bias is often overlooked. Therefore, this study proposes an integrated multivariate genetic matching and stochastic DEA algorithm to evaluate the efficiency of container ports. It paves the way for container ports that differ in a selected feature, such as size, to be benchmarked using well-balanced clusters. Thus, the port managers can identify the most similar-featured peers in benchmarking with DEA or alternative models to acquire robust estimates without dependence on a longitudinal data set. The results of the model applied to international container ports imply the increase in size impacts efficiency negatively, while connectivity does positively, which contradicts the commonly held perception of stakeholders that the larger the container ports, the more efficient. That is, well-managed small container ports can also be as efficient. Therefore, it is concluded that the results of integrating genetic matching into the performance measurement provide beneficial inferences. In future research, clustering the observed container ports according to a specific feature and balancing clusters with multivariate genetic matching can provide valuable insights into the industry.

The Impact of Port Total Factor Productivity on Carbon Dioxide Emissions in Port Cities: Evidence from the Yangtze River Ports

This paper investigates the relationship between port productivity and carbon dioxide (CO2) emissions in port cities. The study initially employs the global Malmquist productivity index (MPI) to measure productivity growth in 16 major inland ports along the Yangtze River, obtaining data on the ports’ total factor productivity (TFP). Through an analysis using the panel data model with two-way fixed effects, we find a positive correlation between the improvement of port TFP and the increase in CO2 emissions in port cities. Further panel quantile regression analysis reveals the heterogeneity of this impact, especially in cities with medium and higher CO2 emissions, where the positive effects of TFP on carbon emissions are particularly significant. The study also indicates a threshold effect of port size in the relationship between TFP and CO2 emissions: in smaller ports, the impact of TFP improvement on CO2 emissions is less significant; however, once the port size exceeds a certain threshold, the growth in TFP significantly promotes an increase in CO2 emissions. These findings provide theoretical justification and decision-making references for policymakers to adopt effective measures to mitigate the growth of CO2 emissions while promoting the efficiency of port production.

Liquid Atomization in Rotary Slinger Injectors: Role of Liquid Delivery Manifold

In rotary injectors, the method of liquid delivery can play an important role in the quality of liquid atomization. In slingers, which are employed in small gas turbine engines, the liquid delivery manifold is a key component in the atomizer assembly, which not only delivers the liquid to the atomizer but also acts as a fuel metering device. In the present work, we investigate the liquid atomization in a slinger atomizer with a focus on the effect of the number of liquid delivery ports and port size in the static manifold. Different optical diagnostics are employed to visualize primary liquid breakup and measure droplet size. The results showed that, at a low liquid feed rate, a smaller number of injection ports or port size promotes supercritical breakup (annular liquid exit and disintegration) at an orifice exit such that the breakup length and droplet size are smaller. Also, hole-to-hole variation in the liquid breakup mode is noticed, which refers to different breakup mechanisms in adjacent slinger orifices. On the other hand, Coriolis-induced film breakup is promoted when the liquid feed rate increases. The present study highlights that the design of the delivery manifold can potentially influence spray performance in slinger injectors.

Robotic Approach to Paediatric Gastrointestinal Diseases: A Systematic Review.

The use of minimally invasive surgery (MIS) for paediatric surgery has been on the rise since the early 2000s and is complicated by factors unique to paediatric surgery. The rise of robotic surgery has presented an opportunity in MIS for children, and recent developments in the reductions in port sizes and single-port surgery offer promising prospects. This study aimed to present a systematic overview and analysis of the existing literature around the use of robotic platforms in the treatment of paediatric gastrointestinal diseases. In accordance with the PRISMA Statement, a systematic review on paediatric robotic gastrointestinal surgery was conducted on Pubmed, Cochrane, and Scopus. A critical appraisal of the study was performed using the Newcastle Ottawa Scale. Fifteen studies were included, of which seven were on Hirschsprung's disease and eight on other indications. Included studies were heterogeneous in their populations, age, and sex, but all reported low incidences of intraoperative complications and conversions in their robotic cohorts. Only one study reported on a comparator cohort, with a longer operative time in the robotic cohort (180 vs. 152 and 156 min, p < 0.001), but no significant differences in blood loss, length of stay, intraoperative complications, postoperative complications, or conversion. Robotic surgery may play a role in the treatment of paediatric gastrointestinal diseases. There is limited data available on modern robotic platforms and almost no comparative data between any robotic platforms and conventional minimally invasive approaches. Further technological developments and research are needed to enhance our understanding of the potential that robotics may hold for the field of paediatric surgery.

Effects of location of nano-enhanced PCM-packed bed on the process of heat transfer and phase transition in a nonuniform magnetic field

The phase change and thermal process intensification under nonuniform magnetic field (MGF) effects during hybrid nanofluid (NF) convection are investigated in this study using various arrangements of phase change material (PCM)-packed bed (PB) in a vented cavity. The PCM-PB is is considered as a triangular shape. The numerical research is done using the finite element method for different Reynolds numbers (Re between 200 and 600), inlet port sizes (between 0.5 and 2.5), Hartmann numbers (Ha between 0 and 60), nonuniform MGF component amplitudes (between 0 and 1), and different locations of the triangle PCM-PB zone. The process of phase change is accelerated by increasing the Re and port size, and the entire transition time (tf ) is reduced by 63% and 76%, respectively, when mix/max Re and min/max port sizes are considered. By using NF, the phase change is improved even further, and tf is further reduced by 17.6%–31.5%. When MGF strength and amplitude of the nonuniform component are increased, tf is reduced by about 13% and 6%. At the highest Ha, the average heat transfer (HT) drops by about 59%. The flow patterns, phase transition, and thermal performance are all significantly impacted by the placement of the PCM-PB zone. In terms of phase change process, configuration C2 by using NF at Ha = 60 is the best case while case at Ha = 0 by using only water is the worst case. The tf value is reduced by about 82.6% at the best case. When phase change and HT processes are considered, the optimal design of triangular PCM-PB zones alters.

Comparison of three-port versus four-port laparoscopic cholecystectomy

Background: In the era of laparoscopic surgery, early recovery and less post-operative pain are major goals to improve patient care and cut down cost. Several studies have demonstrated less post-operative pain and early recovery with the reduction in size and number of ports. Aims and Objectives: To compare three-port laparoscopic cholecystectomy (LC) with four-port LC in chronic calculous cholecystitis patients. We compared the feasibility of the procedure, total operative time, intraoperative difficulties, post-operative pain, incidence of complications, and cosmetic results. Materials and Methods: The study was done in Maharani Laxmi Bal Medical College, Jhansi, between April 2021 and November 2022, including 2 groups of patients (Group A-50 patients of three-port LC and Group B-50 patients of four-port LC). Results: Most of the participants were from 18 to 30 years (32%, 38%) and 31 to 40 years (30%, 12%) in both the groups. The mean duration of surgery in three-port and four-port group was 41.64±6.972 and 42.22±13.784 min, respectively (p=0.79). Hospital stay was three-port and four-port group was 3.33±0.789 and 3.86±0.707 days, respectively (p=0.0001). 100 patients were included, with 2085 patients. The mean age of the studied patients was 46.38 years with female preponderance. The mean operative time for three ports was 66.90 min and for four ports, it was 75.45 min. The mean duration of post-operative stay for three-port was 4.66, and for the conventional group, it was 5.30. Conclusion: Three-port lap cholecystectomy can be advocated to be better than the 4-port technique, but especially in experienced hands, and 4-port LC is better for beginners.

Study on the Influence of Urban Water Supply Pipeline Leakage on the Scouring Failure Law of Cohesive Soil Subgrade

Urban water supply pipelines serve as vital lifelines for urban operations. However, the occurrence of underground pipeline leakage, caused by various factors, results in significant water loss and gives rise to safety hazards such as pavement collapse due to the erosive action of leaking water on the overlying soil. To conduct a more comprehensive investigation into the erosion characteristics of the leaking jet on the soil, this study employed a custom-built soil-test system to investigate the erosive effects of leakage from the water supply pipe network on the clay roadbed above. The study considered water flow rate, leakage port size, and leakage angle as influential factors. The experimental results demonstrated that reducing the water flow rate significantly enhances the soil’s erosion resistance. There is a positive correlation between the caliber of pipe leakage, pipe diameter, and the erosion rate of the soil cavity. Under identical conditions, the erosion rate of the specimen increased consistently with an increase in the leakage port angle. The study also investigated and summarized the curve depicting the formation of soil cavities. The aforementioned findings offer valuable insights for the implementation of reinforcement measures using fine-grained cohesive soil backfill in urban water supply pipelines.

Estimating recreational trap‐fishing effort for crayfish from zig‐zag line transects, drone surveys and enforcement surveys

AbstractEstimates of recreational fishing effort and catch are needed to inform fisheries management, but such estimates can be challenging to obtain. We combined a zig‐zag line transect survey of buoys, a fisheries enforcement survey and a drone survey to estimate recreational effort in the open‐access trap fishery for signal crayfish (Pacifastacus leniusculus) in the sixth largest lake in Europe, Lake Vättern, Sweden. Using supporting variables such as size of nearby ports and bathymetry, our model‐assisted estimate of total effort was 6400 (±4300 CI) buoys during the three‐weekend season. Using the frequency of buoys to traps as a constant, the total number of crayfish traps was estimated to be 25,500 (±17,000 CI). The sampling design and methods presented are useful for ecologists and resource managers to design future multi‐source surveys of recreational trap fishing effort.