Society Of Marine Science and TechnologyInternational Journal Of Coastal, Offshore And Environmental Engineering(ijcoe)2980-873111320260601Experimental study of gas flow regime criteria in underwater gas-saturated liquid blowouts11624841910.22034/ijcoe.2026.586849.1247ENMaryamBafandehDepartment of Physical Oceanography, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran0009-0008-3922-194XAbbas Ali Ali AkbarBidokhtiInstitute of Geophysics, University of Tehran, Tehran, Iran0000-0003-4841-2218MojtabaEzamDepartment of Physical Oceanography, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran0000-0002-1627-5741MajidGhodsi HasanabadDepartment of Mechanical Engineering, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran0000-0002-1683-0020SaraAllahyari BeykDepartment of Physical Oceanography, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran0000-0002-5911-5502Journal Article20260112In a series of laboratory experiments, CO2-saturated freshwater at different volumetric gas to liquid ratios (GLR) and different flow momentums was injected at the bottom of square cross-section open-top basins filled with homogeneous saltwater as well as stratified saltwater. Flow visualization of the experiments and comparison of different criteria for discerning the gas flow regimes showed that Wallis (1969) critical velocity criterion and Payne and Prince (1975) modified Froude number criterion are more suitable to distinguish the gas flow regimes in gas-saturated liquid blowouts. The other evaluated criteria of modified Froude number, Reynolds number, and modified Weber number, overestimate the ratio of inertia and bubble destructive forces to breakup resisting forces in gas-saturated liquid blowouts. It seems that off-source rapid formation of a huge number concentration of minute bubbles in the zone of flow establishment and momentum-driven region decreases the inertia and bubble destructive forces in gas-saturated liquid blowouts when compared to bubbly jets of similar GLR and flow rates.https://www.ijcoe.org/article_248419_443a96c4d35a29fd3fa4b0a395606655.pdfSociety Of Marine Science and TechnologyInternational Journal Of Coastal, Offshore And Environmental Engineering(ijcoe)2980-873111320260601Changes of Physical Parameters of the Water Column from the Indian Ocean to the Persian Gulf173324848610.22034/ijcoe.2026.517485.1164ENMahyarMajidi NikResearcher of the Department of Environmental Geography Studies, Madde Danesh Studies Center. 0000-0003-4062-1779ParvanehSobhaniAssistant Professor, Department of Environment, Faculty of Natural Resources, Lorestan University, Khorramabad, Iran0000-0001-9878-3768Journal Article20260129A comprehensive and complete understanding of how physical parameters and sound wave propagation change in different places and times is essential and inevitable. The present study examined and evaluated vertical and horizontal changes in temperature, salinity, and sound velocity parameters in the seas surrounding the country's south, including the Persian Gulf, the Strait of Hormuz, the Sea of Oman, and the northern Indian Ocean. The physical parameters of the water column in the two cold and warm seasons of the region have been monitored and analyzed at selected stations in the aforementioned seas from the surface to the bed using the international data of the World Ocean Atlas 2018. The results of the studies indicate the existence of a permanent thermocline layer in the deep regions of the Oman Sea and the northern Indian Ocean, due to which the propagation of sound waves is reduced by more than 30 units. In the Persian Gulf and the Strait of Hormuz, due to the shallowness of the region, the thermocline layer is created only in the warm season of the region, and as a result, a weak sound channel is formed at depths near the bed. It should be noted that in all the studied regions, the propagation speed of sound waves is strongly dependent on the temperature parameter and its resulting changes in the water column are similar to vertical temperature changes. Also, two-dimensional sections indicate the penetration of salty waters of the Persian Gulf into the Oman Sea in layers near the bed throughout the year.https://www.ijcoe.org/article_248486_9ce081f9adcb45bdb80c7fb50a46c9c0.pdfSociety Of Marine Science and TechnologyInternational Journal Of Coastal, Offshore And Environmental Engineering(ijcoe)2980-873111320260601Hybrid Intelligence for Coastal Pattern Recognition: ANFIS-Based Prediction of Multi-Level Beach Cusp Spacing344723712510.22034/ijcoe.2025.523922.1171ENAzadehValipourDepartment of Marine Science and Technology, Jouybar Branch, Islamic Azad University, Jouybar, Iran0000-0003-4345-0928HosseinShirgahiDepartment of Computer Engineering, Jouybar Branch, Islamic Azad University, Jouybar, Iran0000-0001-9034-3549Journal Article20260224Given the necessity of understanding coastal dynamics and predicting erosion in coastal areas, this research employs the Adaptive Neuro-Fuzzy Inference System as a machine learning model for predicting beach cusp spacing and subsequently optimizing coastal management. ANFIS has the advantage over other techniques to model the more complex nonlinear relationships involved in beach cusp formation. It learns from existing data, adapts to new information varying with coastal hydrodynamic conditions, and gives back to the user interpretability by showing underlying rules dictating cusp dynamics. This paper discusses implementing ANFIS to predict beach cusp spacing and examines its performance against a neural network. In this way, different ANFIS configurations were tested, and the effect of membership functions on the performance of the fuzzy system was investigated. The main outcomes of this research indicate that even though optimized Artificial Neural Network (ANN) models perform reasonably well for the upper beach face, the optimized ANFIS (trimf) model performs better in accuracy and stability for the middle and lower beach faces. This study effectively highlights the importance of selecting the optimal model tailored to each beach section's specific conditions and characteristics.https://www.ijcoe.org/article_237125_3cd18e369c2257824b409b7803b4e255.pdfSociety Of Marine Science and TechnologyInternational Journal Of Coastal, Offshore And Environmental Engineering(ijcoe)2980-873111320260601Numerical simulation of bottom outlet valve openings and reverse slope transition to control downstream pressure drop in pipeline of effluent discharge to sea485524848710.22034/ijcoe.2026.587384.1249ENSaeedMadadyariDepartment of Civil Engineering, Na.C., Islamic Azad University, Najafabad, IranMehdiNezhadnaderiDepartment of Civil Engineering, To.C., Islamic Azad University, Tonekabon, Iran.0000-0003-1160-358XBabakFazli MalidarehDepartment of Civil Engineering, Bab.C., Islamic Azad University, Babol, Iran.0000-0001-8916-7015Journal Article20260227Bottom outlets are a set of structures used to transfer water from the dam reservoir to the downstream. Therefore, due to the importance of this part of the dam, the study of the cavitation phenomenon is particularly sensitive. In the downstream bottom outlets, the flow is transferred at high speed, and due to the separation of the flow and its sudden transformation from a pressurized state to a free state, a sharp drop in the pressure values downstream of the valve occurs. The flow passing under the valve creates a swirling flow downstream of it, the main characteristic of which is a sharp pressure drop. The drop created is a function of the valve opening, the water head behind the valve, and the geometry of the channel. On the other hand, severe pressure fluctuations cause a decrease in local pressure in that area, and due to the high flow velocity, the potential for cavitation increases. How to minimize the negative pressures created downstream of the valve is one of the important issues that are raised in the case of valves. The negative pressures created will ultimately lead to damage to the downstream structure and the valve itself. Cavitation is one of the most unpleasant hydrodynamic phenomena that occurs as a result of such negative pressures created downstream of the valve. In this paper, the governing equations of flow in the two-dimensional case in the physical model of the bottom outlet of the Narmashir dam were solved using appropriate turbulence models to calculate the flow and turbulence pattern. The pressure values were obtained from the numerical solution and then the pressure values on the bottom outlet and the surface in front of the bottom outlets were investigated for 30, 50, and 80 percent opening. The results show that the pressure values obtained from the numerical model follow a similar pattern as the results of physical model. With greater opening, the pressures on the bottom and top of the bottom outlet decrease. In this study, by installing a reverse slope transition after the valves and a larger diameter pipe after the transition, the negative pressure at the end of the pipe after the valve can be reduced. By opening the valve up to 50%, this negative pressure is reduced and the possibility of wastewater returning to the pipe is reduced. Also, the risk of cavitation due to direct impact of the jet with the seabed is reduced. A very strong jet may cause: sediment erosion, local mud, pollution, bed erosion and damage to benthic habitats near the seabed. Therefore, installing a reverse slope transition and an end pipe with a larger diameter than the transfer pipe can be a good idea to reduce the risk of the jet impacting the seabed.https://www.ijcoe.org/article_248487_edf5394f0ab276b24b84292202538ca4.pdfSociety Of Marine Science and TechnologyInternational Journal Of Coastal, Offshore And Environmental Engineering(ijcoe)2980-873111320260601Data-Driven Assessment and Forecasting of Port Services Demand: A Case Study of Shahid Rajaee Port566824848810.22034/ijcoe.2026.585298.1242ENPouriaRafatiSchool of Civil Engineering, College of Engineering, University of Tehran, Tehran, Iran0009-0004-5117-1421Seyede MasoomeSadaghiRoad, Housing & Urban Development Research Center, Tehran, Iran0000-0003-4227-1725AliFakherSchool of Civil Engineering, University of Tehran, Tehran, Iran0000-0001-6036-2212Journal Article20260318Ports play a vital role in maritime transport and international trade, and port services—as a critical component of the maritime supply chain—significantly influence overall port efficiency. Accordingly, accurately forecasting port service demand in relation to economic fluctuations, trade constraints, and infrastructural conditions is essential for operational planning and infrastructure development. This study aims to analyze various categories of port services and to forecast service demand, with a specific focus on Shahid Rajaee Port. For this purpose, real operational data—including maritime and land-side traffic information and key performance indicators—were collected, refined, and analyzed using regression, time-series and moving-average models. The results indicate that variables such as cargo handling volume, number of incoming vessels, duration of marine service operations, truck and rail flows, economic and political conditions have a decisive impact on port service demand. The findings of this research provide valuable guidance for managers in resource allocation, capacity development, congestion management, and enhancing port operations in line with sustainable development objectives.https://www.ijcoe.org/article_248488_f1d2e17c7c4d64be68159351562a2fa8.pdfSociety Of Marine Science and TechnologyInternational Journal Of Coastal, Offshore And Environmental Engineering(ijcoe)2980-873111320260601A Critical Review of Challenges and opportunities in Using Remote Sensing and Image Processing for Rip Current Studies698523712110.22034/ijcoe.2025.516768.1161ENAzadehValipourDepartment of Marine Science and Technology, Jouybar Branch, Islamic Azad University, Jouybar, Iran0000-0003-4345-0928Journal Article20260331Rip currents, often appearing as mushroom-shaped features within the surf zone, are a primary cause of swimmer drownings along beaches worldwide. Due to their transient nature, the application of advanced remote sensing and computer vision techniques for localized detection of these phenomena significantly mitigates the limitations traditionally associated with their study. In addition to these methods, the emergence of machine learning and artificial intelligence (AI) techniques provides powerful tools for a more precise investigation of rip currents, offering substantial support to remote sensing approaches and enhancing the efficiency of coastal lifeguard operations on larger scales. This study aims to present a comprehensive review of the relevant literature from 2014 to 2023, evaluating both traditional and modern approaches to analyzing the behavior of these coastal currents. Particular emphasis is placed on examining the conducted studies, including details on the categorization of research objectives, comparison of various tools, and exploration of associated opportunities and challenges.https://www.ijcoe.org/article_237121_ae4e5fa179c6bdcbc7a6ad3416977421.pdfSociety Of Marine Science and TechnologyInternational Journal Of Coastal, Offshore And Environmental Engineering(ijcoe)2980-873111320260601The failure probability of reinforced concrete marine structures and cost optimization of maintenance869724848910.22034/ijcoe.2026.585601.1243ENAbdolhosseinMoahammad RahimiDepartment of Marine Engineering, Chabahar maritime university, Shahid Rigi Ave, Chabahar, Iran0000-0001-7560-6400AfshinGhasriDepartment of Maritime Engineering, Amirkabir University of Technology, Hafez Ave, Tehran, IranMesbahSayebaniDepartment of Maritime Engineering, Amirkabir University of Technology, Hafez Ave, Tehran, Iran0000-0002-9482-3248AkbarEsfandiariDepartment of Maritime Engineering, Amirkabir University of Technology, Hafez Ave, Tehran, Iran0000-0002-1358-2754Journal Article20260402Due to the increased life of marine structures in the world, repair and maintenance of low cost and high reliability are of concern in this industry. In this paper, the corrosion-induced crack width of reinforced concrete (RC) structure in the marine environment is estimated according to the experimental data, laboratory results, and numerical formulas. Symptom-based Weibull function distribution and Bayesian theory have been used to predict the structural reliability in different modes (without repair and maintenance, with maintenance, and with repair and maintenance) and the probability of failure was assessed before and after maintenance to predict the appropriate time for its implementation using Bayesian theory. Bi-objective optimization was utilized to provide the client with optimal decisions regarding the probability of structural failure as well as the type of repair and maintenance strategies. The results showed the effectiveness of the proposed method in predicting performance, improving life service, and optimizing repair and maintenance costs of the marine structure.https://www.ijcoe.org/article_248489_c99604698f81b2454389e8e3b6d3520b.pdfSociety Of Marine Science and TechnologyInternational Journal Of Coastal, Offshore And Environmental Engineering(ijcoe)2980-873111320260601The Role of Standards in Maritime-Based Development: An Analysis of Challenges in Iran’s Maritime Industry9810524849010.22034/ijcoe.2026.574249.1223ENAmir NezamBaratiAssistant Professor of Law, Department of Law, Imam Khomeini Maritime Science University, Mazandaran, Iran0000-0002-0129-6670MeysamBaliAssistant Professor, Faculty of Marine Engineering, Amirkabir University of Technology, Tehran, Iran0009-0004-8602-6953AliAlimohamadpour4 Assistant Professor, Department of Economic and Accounting, Imam Khomeini Maritime Science University, Mazandaran, Iran0000-0002-0129-6670Journal Article20260413Abstract<br><br>Maritime-based development has emerged as a critical pathway for achieving sustainable economic growth, particularly for coastal states whose industries depend on safe, efficient, and environmentally responsible maritime operations. Despite its strategic maritime position, Iran faces significant challenges in aligning its maritime sector with international standards. This study examines the role of technical, legal, and operational standards in shaping maritime-based development, with a focus on identifying structural barriers within Iran’s maritime industry. Employing a comparative qualitative methodology, the research analyzes international benchmarks—including key IMO conventions such as SOLAS, MARPOL, and STCW—and compares them with Iran’s existing regulatory framework, institutional capacities, and enforcement practices.<br><br>The findings reveal several critical gaps, including outdated regulatory instruments, weak and fragmented inspection mechanisms, insufficient adherence to IMO-mandated safety and environmental standards, and limited integration of global best practices in maritime education and training. Additionally, the study identifies institutional overlap and lack of inter-agency coordination as major obstacles to effective implementation.The research concludes that Iran can significantly enhance its maritime competitiveness by updating national regulations, strengthening port and vessel inspection systems, adopting a unified maritime governance structure, and fully harmonizing its educational programs with STCW requirements. These reforms are essential for enabling Iran to transition toward a modern, safe, and globally competitive maritime economy, thereby leveraging its maritime geography for sustainable national development.https://www.ijcoe.org/article_248490_278adcdfd909dbab402ab2227d0d1beb.pdf