bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of cancer risk associated with 7‐nitroso‐3‐(trifluoromethyl)‐5,6,7,8‐tetrahydro[1,2,4] triazolo‐[4,3‐a]pyrazine‐contaminated sitagliptin use: A retrospective cohort study
Authors: Sugiyama Takehiro , Furuno Takashi , Ichinose Yuichi , Iwagami Masao , Ihana‐Sugiyama Noriko , Imai Kenjiro , Kakuwa Tamaki , Rikitake Ryoko , Ohsugi Mitsuru , Higashi Takahiro , Iso Hiroyasu , Ueki Kohjiro
Published: August 2024

Aims/Introduction

A recent US Food and Drug Administration report highlighted concerns over nitrosamine (7‐nitroso‐3‐(trifluoromethyl)‐5,6,7,8‐tetrahydro[1,2,4] triazolo‐[4,3‐a]pyrazine [NTTP]) impurities in sitagliptin, prompting investigations into its safety profile. The present study aimed to determine if the use of NTTP‐contaminated sitagliptin, in comparison with other dipeptidyl peptidase‐4 (DPP‐4) inhibitors, is associated with an increased cancer risk.

Materials and Methods

This retrospective cohort study secondarily used the National Database of Health Insurance Claims and Specific Health Checkups of Japan, encompassing data on >120 million individuals. The study involved patients who initiated DPP‐4 inhibitor therapy (sitagliptin or other DPP‐4 inhibitors) and continued its exclusive use for 3 years. Sitagliptin users were compared with other DPP‐4 inhibitor users for assessing the occurrence of cancers, as defined by diagnosis codes. Further analyses focused on specific types of cancer, using either diagnosis codes or a combination of diagnosis and procedure codes. We also carried out various sensitivity analyses, including those with different exposure periods.

Results

Sitagliptin users (149,120 patients, 388,356 person‐years) experienced 9,643 cancer incidences (2,483.0/100,000 person‐years) versus 12,621 incidences (2,504.4/100,000 person‐years) among other DPP‐4 inhibitor users (199,860 patients, 503,952 person‐years), yielding a minimal difference (incidence rate ratio 0.99, 95% confidence interval 0.97–1.02). A multiple Cox proportional hazards model showed no significant association between sitagliptin use and overall cancer incidence (hazard ratio 1.01, 95% confidence interval 0.98–1.04). Findings were also consistent across cancer types and sensitivity analyses.

Conclusions

We observed no evidence to suggest an increased cancer risk among patients prescribed NTTP‐contaminated sitagliptin, although continued investigation is needed.
Prevalence of adherence to oral antidiabetic drugs in patients with type 2 diabetes: A systematic review and meta‐analysis
Authors: Boonpattharatthiti Kansak , Songkla Pirune Na , Chantara Junpen , Koomsri Chanchanok , Krass Ines , Chaiyakunapruk Nathorn , Dhippayom Teerapon
Published: August 2024

Introduction

The treatment of type 2 diabetes requires multidimensional management, with medication adherence a crucial aspect of diabetes control. However, recent rigorous estimates of adherence to oral antidiabetic drugs (OAD) are lacking. The objective of this study is to determine the prevalence of adherence to OAD in type 2 diabetes patients.

Methods

A systematic search was performed in PubMed, EMBASE, PsycINFO, and CINAHL from July 2013 to April 2023. Cross‐sectional studies published in English were included if they met the following criteria: (1) reported the adherence to OAD using a validated measure; and (2) had a sample size of at least 385 patients with type 2 diabetes. The Joanna Briggs Institute critical appraisal for studies reporting prevalence data was used to assess the quality of the included studies. Pooled estimates of the prevalence of adherence to OAD were calculated as a percentage together with 95% confidence interval (95% CI) using a random‐effect model. All analyses were conducted using STATA 17.0; PROSPERO (CRD42023414264).

Results

Twenty‐six studies involving a total of 69,366 patients met the selection criteria and were included in the meta‐analysis. The overall estimated prevalence of adherence to OAD was 55.53% (95%CI: 44.22%–66.85%). Among the included studies, nine were deemed to be of high quality. A sensitivity analysis conducted using only the high‐quality studies revealed a prevalence of adherence to OAD at 52.24% (95% CI: 39.63%–64.85%).

Conclusions

The overall prevalence of adherence to OAD was remarkably low among type 2 diabetes patients worldwide. Healthcare practitioners and policy makers should employ appropriate approaches to improve adherence to OAD.
Efficacy of organic acids, lactic and formic acid, and peracetic acid in decontaminating process water and carcasses in chicken slaughter
Authors: Carstens Gesa , Roesler Uwe , Reich Felix , Friese Anika
Published: August 2024

Foodborne pathogens pose a persistent threat in broiler chicken production, particularly during the slaughter process, where contamination with zoonotic pathogens remains a concern. This study focuses on the potential of organic acids, such as formic and lactic acid, and the oxidizing agent peracetic acid, to decontaminate scalding water and enhance the hygiene of chicken carcasses. We conducted suspension tests introducing various organic loads to mirror the conditions of practical scalding water. Additionally, the surface tests were performed on chicken skin. Both methods were further tested in an experimental slaughtering facility. In suspension tests, the organic acids achieved impressive decontamination, with a 5‐log10 reduction of the test organisms Enterococcus hirae, Salmonella Typhimurium and Campylobacter jejuni at minimal concentrations (between 0.04% and 2% for formic acid; between 0.1% and 4.5% for lactic acid). Peracetic acid also effectively sanitized model water and chicken skin, even when used in low concentrations (between 0.001% and 0.1%), both in the laboratory‐based testing and in the experimental slaughtering facility. These results suggest that the tested disinfectants can effectively sanitize process water, even under conditions mimicking practical scalding water with organic matter. Peracetic acid, in particular, proved highly effective in improving chicken skin hygiene even at low concentrations.
Atlas‐guided brain projection tracts: From regions of interest to tractography 3D rendering
Authors: Dauleac Corentin , Mertens Patrick , Frindel Carole , Jacquesson Timothée , Cotton François
Published: August 2024

The use of diffusion tensor imaging (DTI) has seen significant development over the last two decades, in particular with the development of the tractography of association tracts for preoperative planning of surgery. However, projection tracts are difficult to differentiate from one another and tractography studies have failed to reconstruct these ascending/descending pathways from/to the spinal cord. The present study proposes an atlas of regions of interest (ROIs) designed specifically for projection tracts tractography. Forty‐nine healthy subjects were included in this prospective study. Brain DTI was acquired using the same 3 T MRI scanner, with 32 diffusion directions. Distortions were corrected using the FSL software package. ROIs were drawn using the anterior commissure (AC)–posterior commissure (PC) line on the following landmarks: the pyramid for the corticospinal tract, the medio‐caudal part of the red nucleus for the rubrospinal tract, the pontine reticular nucleus for corticoreticular tract, the superior and inferior cerebellar peduncles for, respectively, the anterior and posterior spinocerebellar tract, the gracilis and cuneatus nucleus for the dorsal columns, and the ventro‐posterolateral nucleus for the spinothalamic tract. Fiber tracking was performed using a deterministic algorithm using DSI Studio software. ROI coordinates, according to AC–PC line, were given for each tract. Tractography was obtained for each tract, allowing tridimensional rendering and comparison of tracking metrics between tracts. The present study reports the accurate design of specific ROIs for tractography of each projection tract. This could be a useful tool in order to differentiate projection tracts at the spinal cord level.
Short‐term hyposalinity stress increases dissolved organic carbon (DOC) release by the macroalga Sargassum fallax (Ochrophyta)
Authors: Bennett Eloise , Paine Ellie R. , Hovenden Mark , Smith Gregory , Fitzgibbon Quinn , Hurd Catriona L.
Published: August 2024

Dissolved organic carbon (DOC) released by macroalgae supports coastal ocean carbon cycling and contributes to the total oceanic DOC pool. Salinity fluctuates substantially in coastal marine environments due to natural and anthropogenic factors, yet there is limited research on how salinity affects DOC release by ecologically important macroalgae. Here we determined the effect of short‐term salinity changes on rates of DOC release by the habitat‐forming fucalean seaweed Sargassum fallax (Ochrophyta). Lateral branches (~4 g) cut at the axes of mature individuals were incubated across a salinity gradient (4–46) for 24 h under a 12:12 light:dark cycle, and seawater was sampled for DOC at 0, 12, and 24 h. Physiological assays (tissue water content, net photosynthesis, respiration, tissue carbon, and nitrogen content) were undertaken at the end of the 24‐h experiment. Dissolved organic carbon release increased with decreasing salinity while net photosynthesis decreased. Dissolved organic carbon release rates at the lowest salinity tested (4) were ~3.3 times greater in the light than in the dark, indicating two potential DOC release mechanisms: light‐mediated active exudation and passive release linked to osmotic stress. Tissue water content decreased with increasing salinity. These results demonstrate that hyposalinity stress alters the osmotic status of S. fallax, reducing photosynthesis and increasing DOC release. This has important implications for understanding how salinity conditions encountered by macroalgae may affect their contribution to the coastal ocean carbon cycle.
Epidemiology and Outcomes of Hepatitis E Virus‐Associated Hospitalisations in the United States With a Focus on Pregnancy: A Nationwide Population Study, 1998–2020
Authors: Wasuwanich Paul , Wen Tony S. , Egerman Robert S. , Karnsakul Wikrom
Published: August 2024

Hepatitis E virus (HEV) is typically asymptomatic in developed countries but can be more severe in certain populations. We aim to describe the epidemiology of HEV‐associated hospitalisations from 1998 to 2020 in the United States, investigate risk factors for inpatient mortality and describe outcomes in pregnant women. We utilised the National Inpatient Sample and extracted cases of HEV‐associated hospitalisations using ICD‐9/10 diagnostic codes. Demographic, clinical and pregnancy data were extracted and analysed by chi‐square and logistic regression. We identified 3354 cases of HEV‐associated hospitalisations; 1689 (50.4%) were female and 1425 (42.5%) were non‐Hispanic White. The median age was 50 (IQR: 37–59) years. Hospitalisation rates for HEV ranged from 2.5 per 10,000,000 in 2008 to a peak of 9.6 per 10,000,000 people in the general U.S. population in 2004. The mortality rate was 5.2%. Age ≥ 40 years (OR: 7.73; 95% CI: 1.57–38.09; p = 0.012), HIV infection (OR: 4.63; 95% CI: 1.26–16.97; p = 0.021), and coagulopathy (OR: 7.22; 95% CI: 2.81–18.57; p < 0.001) were associated with increased odds of mortality within the HEV cohort. There were 226 pregnant women with HEV. Rates of maternal death, stillbirth and preterm birth were similar between HEV and non‐HEV pregnant cohorts. Hepatitis B and hepatitis C co‐infection were significantly more common in the HEV pregnant cohort (p < 0.05). HEV‐associated hospitalisations are uncommon in the United States, but likely underdiagnosed. Certain risk factors can be used to predict prognosis of these hospitalised patients. Pregnant women with HEV appear to have favourable maternal and fetal outcomes despite hepatitis B and C co‐infection.
Spatiotemporal plasticity of prey selection in the wolf
Authors: Belardi I. , Borkowski J. , Lazzeri L. , Banul R. , Pacini G. , Poerling A. , Ferretti F.
Published: August 2024

Under an optimal foraging scenario, prey selection would be expected to occur when food resources are abundant. A positive frequency‐dependent prey selection would elicit prey switching when the abundance of main food resources decreases, potentially favouring community resilience to the effects of intensive, selective predation on a single prey. We assessed whether a positive frequency‐dependent prey selection by the wolf Canis lupus occurred in two areas hosting abundant populations of wild ungulates, one in northern (Słowiński National Park, Poland) and the other one in southern (Maremma Regional Park, Italy) Europe, throughout a cold semester. In Słowiński, ungulate community was dominated by red deer Cervus elaphus (57% availability) over wild boar Sus scrofa (35%) and roe deer Capreolus capreolus (8%); wild boar and fallow deer Dama dama (43–37%) were more abundant than roe deer (20%) in Maremma. In both areas, wolf diet was dominated by wild ungulates, with a major use of red deer in Słowiński and wild boar in Maremma. Prey selection occurred in both areas, and it was addressed towards the most abundant prey in Słowiński, that is, the red deer, but only towards the wild boar in Maremma, where the fallow deer was used according to availability. In Slowinski, high red deer density may have driven wolf prey selection, while the shifting of activity rhythms of the fallow deer in the Maremma as antipredator response to wolf presence may have reduced predation. Despite its comparable densities between the two areas, the wild boar was selected in Maremma and under‐used in Słowiński. Results provide partial support to positive frequency‐dependent selection, emphasising the spatiotemporal plasticity of wolf–prey relationships. The relative role of prey density and other factors (e.g., antipredator behavioural responses) should be assessed at longer temporal scales.
Analyzing prejudice against immigrants in sending countries: The Brazilian case
Authors: Guimarães Feliciano de Sá , Fernandes Ivan Filipe
Published: August 2024

Prejudice against immigrants has been widely studied in the literature, but analyzing immigrant‐receiving countries is not the same as analyzing sending countries, where the number of immigrants is very low. To address this gap, we examine the case of Brazil, a country that has witnessed numerous anecdotal episodes of prejudice against immigrants despite having a very low flow of migrants and therefore minimal material effects on the local population. Our study focuses on the levels of discrimination against immigrants in Brazil, with a specific analysis of four groups—Haitians, Germans, Venezuelans, and internal migrants known as nordestinos. We consider three policy‐related scenarios—housing, health care, and job training. To mitigate social desirability bias, we employ a combination of list and endorsement survey experiments in a face‐to‐face national sample of 1850 respondents conducted in January 2019. The results reveal a widespread negative perception of all groups of foreigners across all scenarios except the local group of migrants. The findings suggest that the Brazilian public's discrimination against foreigners is linked to a pervasive misperception of the social and economic threat immigrants allegedly pose to the nation.
Molecular mechanisms of enteric neuropathies in high‐fat diet feeding and diabetes
Authors: Cingolani Francesca , Balasubramaniam Arun , Srinivasan Shanthi
Published: August 2024

Background

Obesity and diabetes are associated with altered gastrointestinal function and with the development of abdominal pain, nausea, diarrhea, and constipation among other symptoms. The enteric nervous system (ENS) regulates gastrointestinal motility. Enteric neuropathies defined as damage or loss of enteric neurons can lead to motility disorders.

Purpose

Here, we review the molecular mechanisms that drive enteric neurodegeneration in diabetes and obesity, including signaling pathways leading to neuronal cell death, oxidative stress, and microbiota alteration. We also highlight potential approaches to treat enteric neuropathies including antioxidant therapy to prevent oxidative stress‐induced damage and the use of stem cells.
Tribulus (Zygophyllaceae) as a case study for the evolution of C2 and C4 photosynthesis
Authors: Leung Arthur , Patel Ria , Chirachon Varosak , Stata Matt , Macfarlane Terry D. , Ludwig Martha , Busch Florian A. , Sage Tammy L. , Sage Rowan F.
Published: August 2024

C2 photosynthesis is a photosynthetic pathway in which photorespiratory CO2 release and refixation are enhanced in leaf bundle sheath (BS) tissues. The evolution of C2 photosynthesis has been hypothesized to be a major step in the origin of C4 photosynthesis, highlighting the importance of studying C2 evolution. In this study, physiological, anatomical, ultrastructural, and immunohistochemical properties of leaf photosynthetic tissues were investigated in six non‐C4 Tribulus species and four C4 Tribulus species. At 42°C, T. cristatus exhibited a photosynthetic CO2 compensation point in the absence of respiration (C*) of 21 µmol mol−1, below the C3 mean C* of 73 µmol mol−1. Tribulus astrocarpus had a C* value at 42°C of 55 µmol mol−1, intermediate between the C3 species and the C2 T. cristatus. Glycine decarboxylase (GDC) allocation to BS tissues was associated with lower C*. Tribulus cristatus and T. astrocarpus allocated 86% and 30% of their GDC to the BS tissues, respectively, well above the C3 mean of 11%. Tribulus astrocarpus thus exhibits a weaker C2 (termed sub‐C2) phenotype. Increased allocation of mitochondria to the BS and decreased length‐to‐width ratios of BS cells, were present in non‐C4 species, indicating a potential role in C2 and C4 evolution.
The novel HLA allele, HLA‐DQB1*02:211, identified in a Brazilian bone marrow donor
Authors: Molinari Isabella Fantini , de Oliveira Anthony Marçal Leão , Massi Fernanda Pelisson , de Lima Neto Quirino Alves , Visentainer Jeane Eliete Laguila
Published: August 2024

HLA‐DQB1*02:211 allele differs from DQB1*02:02:01:02 by change of C → A in exon 2.
Characterisation of a novel HLA‐A*33:33:02 allele in two members of a North Indian family
Authors: Agarwal Samir , Kumari Shikha , Jaiswal Nisha , Kumar Vineeth , Kumar Rajnesh
Published: August 2024

HLA‐A*33:33:02 differs from HLA‐A*33:33:01 by one synonymous nucleotide change C>T in exon 3 (TCC>TCT).
Identification of novel HLA‐C*17:78 allele in North Indian individuals
Authors: Agarwal Samir , Kumari Shikha , Jaiswal Nisha , Kumar Vineeth , Kumar Rajnesh
Published: August 2024

HLA‐C*17:78 differs from HLA‐C*17:03:01:03 by one nucleotide change C>T in exon 3 (GCG>GTG).
Bien Dong Pipeline Field Observation After Span Rectification by Burial
Authors: Teh Thiam Chuan , Zhang Zhishen , Le Duong D. , Nguyen Tam T. , Ly Dao V. , Nguyen Nghiem T.
Published: August 2024

Bien Dong Petroleum Operating Company (BDPOC) corrected spans for a 20-inch 44km-long pipeline in 2014, 2015 and 2016 by placing grout bags under spans that were too long and could be at risk of excessive fatigue damage. Despite three successful correction campaigns, a 2017 survey revealed more spans needing rectification. This posed ongoing challenges for grout bag corrections throughout the pipeline’s lifespan. To reduce future annual span correction costs, BDPOC decided to lower and bury the pipeline in 2018. This was considered a cost-effective long-term solution to avoid ongoing span corrections. However, the recent surveys from 2019 to 2023 revealed that this was not always the case. Many pipeline sections had become exposed, and in some places, free spans had developed, exceeding the allowable span lengths. This paper explores span reappearance after pipeline lowering and burial. It analyzes free span characteristics along Bien Dong 20-inch pipeline over the years, including new span formation, the disappearance of existing spans, and changes in span length. It also compares the span characteristics measured from 2013 to 2017 prior to the pipeline burial event. The paper proposes a span evolution mode map and path. It also validates the hypothesis of span correcting itself naturally on the mobile and sandy seabed.
Sustainability Assessment of Offshore Aquaculture System With Self-Sufficient Energy and Feed
Authors: Peng Yixing , Tabeta Shigeru , Duan Fengjun
Published: August 2024

Aquaculture is attracting considerable attention due to market growth and potential environmental benefits but traditional coastal aquaculture systems create pollution and threaten marine ecosystems. Hence, there’s a need for more environmentally-friendly aquaculture approaches. Also, the prices of fish feed are rising, impacting the cost of conventional aquaculture systems as well as energy price fluctuation. The multi-purpose platform integrating marine renewable energy production, fish aquaculture, microalgae cultivation, and processing facilities has been designed to be economically viable in subtropical regions. The platform ensures year-round electricity supply by using ocean thermal energy conversion technology and producing hydrogen during surplus electricity periods. The Inclusive Impact Index (Triple-I) is employed to evaluate the sustainability of the multi-purpose platform in comparison to conventional aquaculture. The results reveal that while conventional aquaculture may be more profitable, the Triple-I evaluation indicates its unsustainability. In contrast, the multi-purpose platform offers a substantial environmental advantage, despite its higher initial investment cost.
Response of Perforated Tubular Members Repaired With CFRP to Bending Moment
Authors: Hernández Irving D. , Vaz Murilo A. , Cyrino Julio C. R. , Torres Victor D. , Martinez Jorge L. , Perrut Valber A. , De Paula Gustavo G.
Published: August 2024

In corrosive environments, like the ocean, offshore steel tubular structures operate for long periods without proper protection. Therefore, they are susceptible to perforation damage as consequence of concentrated corrosion, which compromises their structural integrity and increases the risk of progressive collapse. As an alternative to traditional hot-works, composite laminates are being considered for strengthening perforated steel tubular members. However, there is a lack of research on the structural capacity recovered for composite laminate repair for given damage dimensions and geometrical characteristics of tubular members subjected to bending loads. Studying the repair performance on structures subjected to bending loads is relevant because tubular members in offshore units constantly experience combinations of loads. Depending on the structure’s slenderness and damage extension, the bending moment may represent the dimensioning load for repair sizing. This study proposes to experimentally repair and test, under bending load, 1:3 scale samples of flare-boom offshore tubular structures with perforation damage using carbon fiber composite laminates. The responses from experiments and numerical models are compared to investigate strengthening performance and define a suitable patch size through a simplified parametric expression. The results indicate that simulated samples, whose repair was sized by the proposed expression, recovered the bending moment capacity, suggesting the feasibility of the repair and dimensioning procedure.
Static and Fatigue Strength Assessment of Composite Patch Repair
Authors: Paboeuf Stéphane , Deydier Maxime , Sourisseau Quentin , Leprêtre Emilie , Chataigner Sylvain , Chapeleau Xavier
Published: August 2024

Marine and Offshore industries are looking for rapid, efficient and qualified repair solutions for damaged or corroded structures. Patch made in composite materials can offer such qualities as confirmed by the Joint Industry Project StrengthBond Offshore (JIP SBO) led by Bureau Veritas. Indeed, since 2019, Bureau Veritas, in collaboration with its partners, studied and analyzed the strength behaviour of composite patch repairs based on a large numerical and experimental testing campaign.

The JIP SBO consortium designed a layered composite patch composed of an epoxy resin with glass and carbon fibres, and proposed an installation procedure. Small-scale and large-scale specimens were tested in static and fatigue, and numerical simulations were done in order to develop a robust methodology for the strength assessment of composite patch repairs.

This paper first presents the comparison of two patch designs, one with a long scarf at the ends of the bonded composite patch, and the other one with a short scarf. In addition, two manufacturing processes, infusion and hand lay-up, are compared for long scarf specimens. The static resistance of the two patch designs and manufacturing processes is determined by tensile and bending tests. The results show that long scarf specimens have a higher resistance and that the manufacturing process has little influence. Finally, fatigue tests on long scarf specimens, and for the two studied manufacturing processes, are detailed and compared with a FPSO (Floating Production Storage Offloading) histogram.
Torpedo Piles and Suction Piles: Geotechnical Analysis and Installation Experiences in Seek for Optimal Anchoring System in Deepwater Clay Soils
Authors: Castillo Garcia Pablo , Branco L. Fernandes Bernardo , Tsetoulidis Charilaos , Mader Marcello , Orejuela Daniel , Serra Edy , Panayides Stylianos
Published: August 2024

Torpedo piles have emerged as a compelling alternative to conventional suction piles for anchoring floating facilities in deepwater developments. Gaining momentum in the offshore industry over the last decade, their design has been enhanced through specialised laboratory tests and the application of analytical and numerical tools. However, compared to suction piles, there is limited field data on torpedo piles, as their primary use has been in offshore Brazil.

This study is the first step of a series of analysis on torpedo piles aiming at further developing design and installation. Various aspects of the torpedo pile solution need to be thoroughly studied, should this concept prove pivotal in competing with conventional suction piles in offshore frontier acreage. Elements such as anchor dimensions and thus holding capacity, fabrication, transportation and installation costs need to be evaluated in search of the most optimal solution.

Leveraging recent installation feedback from Subsea7 on torpedo piles T-120 and existing literature, this paper presents an interdisciplinary assessment and comparison of suction and torpedo piles. It also includes an analysis of the novel finned pile design, currently applied in an ongoing Subsea7 project in Brazil.

The paper comprises finite element analysis (FEA) to compare holding capacities and offers insights into installation, transportation and fabrication costs of both anchoring systems.
Dynamic Simulations of Influence of Ship Rolling Motion on Aerodynamic Flow Field and Helicopter Loading Under Helicopter-Ship Coupling
Authors: Guo Daming , Chen Zhanyang , Duan Fang
Published: August 2024

The six degrees of freedom (6-DOF) motions of the ship is an important factor for helicopter landing on a ship safely, especially the rolling motion of ships has a short period and large magnitude. This study aims to investigate the changes in the aerodynamic flow field and the influence on the helicopter loading when landing on a ship under rolling motion conditions. In previous studies, the coupled aerodynamic flow field and helicopter loading during helicopter hover on a ship have been analyzed, however, the dynamic process of helicopter landing on a ship has not been adequately analyzed. Hence, a dynamic simulation scheme for the entire landing process of the helicopter is proposed in this study. By comparing the existing static research scheme with the proposed dynamic simulation scheme, the differences between the two methods will be analyzed, and the optimal scheme will be selected to study the coupling between ship and dynamic helicopter landing. The aim is to gain a comprehensive understanding of the landing issues of helicopters on ships under rolling conditions, and to explore the variations in helicopter loading caused by rolling motion. This study will contribute to enhancing the safety and stability of helicopter landing on ships, providing crucial guidance and reference for the design and operation of shipborne helicopters.
Ship As a Buoy: RAO-Driven Heading Adjustment Strategy Based on Restricted Isometry Property
Authors: Zhang Taiyu , Chen Shangyuan , Ma Can , Ren Zhengru
Published: August 2024

The safety and efficiency of marine operations heavily rely on external environmental conditions. Waves emerge as the most crucial factor influencing floating structures, which can be described by the directional wave spectrum. However, real-time in situ wave spectrum measurement are often lacking due to limitations involve in traditional approaches. To address this, estimating the sea state using ship motion responses has emerged as a cost-effective and viable method, known as the wave buoy analogy (WBA). Nevertheless, the performance of WBA varies due to ship’s inherent hydrodynamic properties, i.e., response amplitude operators (RAOs). The performance deterioration can lead to inaccurate estimations of the current sea state, potentially resulting in severe consequences. In this study, an adaptive ship heading adjustment strategy was proposed to circumvent inaccurate ship estimates in certain sea states and ascertain the optimal heading angle. The restricted isometry property was employed to determine the direction where ship can offer a better estimate. The involvement of heading adjustment strategy improved the accuracy and robustness of sea state estimation. Numerical simulations were conducted to validate the effectiveness of the proposed algorithm.
Analysis of the Dynamic Responses of a Barge-Type Platform With Multiple Wind Turbines
Authors: S. A. Vighneshwar , Saha Nilanjan , Rajendran Suresh
Published: August 2024

In recent years, there has been significant growth in ocean exploration. Energy production is an essential component of a multi-purpose platform. Wind turbines are the most space-efficient power-generating systems. This work proposes a barge-type VLFS (Very Large Floating Structure) with multiple wind turbines for the bays or breakwater-protected regions. The current project uses two 1.5 MW WindPACT NREL (National Renewable Energy Laboratory) wind turbines and VLFS utilized in the planning phase of Tokyo’s floating airport. Here, the length of the VLFS is sufficient to hold two wind turbines in cross-wind directions. Developing a fully coupled code that works with multiple wind turbines is difficult, as the modelling of wake interactions is challenging. As a result, this study uses a partially coupled methodology. This method uses a fully coupled code for a single wind turbine to estimate the loads at the tower bottom of the wind turbine. As a preliminary step, the fully coupled and partially coupled methods are verified for various load cases. Different ways of placement of wind turbines on the platform are studied for the two wind turbines. Three such configurations are proposed in the study, highlighting their various advantages over one another. These configurations are examined for their hydrodynamic performance.
A New Approach to Evaluate the Inflow Profile Heterogeneity of Lower Completion Horizontal Well in N Oilfield Middle East
Authors: Shi Shuzhe , Wu Bohong , Nie Zhen , Li Yong , Meng Lei , Zhang Yanna , Cui Weixiang , Zhang Lufeng
Published: August 2024

Horizontal well is one of the main technologies applied in carbonate reservoir development, and open-hole completion is widely adopted in the horizontal wells of Oilfields Middle East. However, the open-hole completion faces several challenges during the well production life. For example, the water or gas breakthrough caused by the uneven production profile will decrease the oil production, increase the surface equipment cost to transport produced gas/water and have a negative influence on the final recovery factor. Therefore, the well-designed lower completion configuration and evaluation for the inflow profiles need to be studied for the purpose of a higher cumulative oil production and a higher recovery factor.

In the present work, the inflow profile heterogeneity calculation approach is proposed, including two coefficients, inflow variation coefficient Cv and inflow Lorenz coefficient CL. Then, coupled model simulation is carried out to determine the optimal lower completion configurations with high efficiency. A production well case with a heterogeneity profile is presented, using the new approach to calculate the inflow variation coefficient Cv and inflow Lorenz coefficient CL between open-hole completion and well-designed lower completion under the coupled-model simulation, the result shows the inflow profile heterogeneity of open-hole completion is larger than the heterogeneity of well-designed lower completion. Therefore, by adopting the optimal lower completion configuration, the homogeneous profile can be achieved and will result in better production performance and a higher oil recovery factor.

This approach was successfully verified by the simulation case, which makes a quantitative evaluation of the inflow profile heterogeneity and provides guidance to the lower completion configuration design and reservoir development.
Statistical Uncertainty of Ship Response to Waves As a Function of Test Duration
Authors: van Essen Sanne , Bunnik Tim , Scharnke Jule
Published: August 2024

Wave-induced ship responses have a natural statistical variability, due to the nature of the ocean waves. This needs to be accounted for in ship design. The uncertainty and extreme values of the ship motions and loads depend on the test or simulation duration. This paper presents the experimental relation between uncertainty of root-mean-square (RMS) and most probable maximum (MPM) response values and the test duration, for a sailing ferry in steep bow-quartering waves. The RMSE uncertainty of the RMS of heave, pitch and relative wave elevation was 2–3% after 0.5 h test duration, reducing to 1% after 1 h. The uncertainty of the measured significant wave height was similar. For MPM values with a low uncertainty you need to perform longer tests. The RMSE uncertainty of the MPM of heave and pitch motions was 12% after 2 h, reducing to 5% after 5 h. This uncertainty is lower for relative wave elevation (2–6% after 2 h; 1–3% after 5 h), and higher for green water force on the accommodation (55–65% after 2 h; 20–40% after 5 h). We cannot use linear simulations to predict the RMS or MPM response values themselves, but we can use them to predict the required experimental duration for a given error tolerance of the RMS of (relative) motions.
Simple Estimation for Extreme Value Distribution of Nonlinear Roll Motion of Ship by RTP Method
Authors: Matsui Sadaoki
Published: August 2024

In a previous study, the author proposed a new RAO-based Translation Process (RTP) method for simple estimation of extreme value distribution (EVD) of narrowband nonlinear responses, and the method can estimate the EVD of wave-induced hull girder sectional forces (including body nonlinearity) with sufficient accuracy.

This paper confirms the applicability of the RTP method to a nonlinear roll motion of ships with nonlinear damping. The RTP method transforms a linear response into a nonlinear response based on the wave height-dependent RAO, and it is important to determine (A) what is considered as a linear response and (B) how to determine the correspondence between a linear and a nonlinear response. Regarding the former (A), if the response at small wave height is regarded as a linear response as in the case of wave loads, the linear response may be overestimated because there can be cases where the linear damping force is close to zero. Therefore, in this paper, the equivalent linearized response of the roll motion in irregular waves is considered as the linear response. For the latter (B), the linear-nonlinear relationship was determined based on the peaks of wave height-dependent RAO in the previous study, but it was found that applying this to the roll motion overestimates the nonlinear effect too strongly. Therefore, the author newly proposes a method to determine the linear-nonlinear relationship based on the standard deviation of the wave height-dependent response spectrum. This method was confirmed to be in good agreement with the time domain simulation results for both high and low damping cases, and for both blunt and sharp exciting moment spectrum cases.
Engineering Critical Assessment for Alternative Materials to IGC Code for LCO2 Carriers Type-C Tanks
Authors: Conti Fabien , Aubert Jean-Michel
Published: August 2024

With the developing market of Carbon Capture, Utilisation and Storage (CCUS), large volumes of CO2 need to be transported over large distances. To this end, a cost-effective solution is to consider the maritime transportation of liquefied CO2 (LCO2). Within the LCO2 carriers, the LCO2 can be contained in large diameter type-C tanks under high pressure / low temperature conditions, typically 19bara at −30°C but with now considering alternates with lower pressures (10bara @−50°C). The consideration of such pressures together with the intended tank diameter leads to the use of high strength steel grades, which are not covered by the International Maritime Organization regulations (IGC Code) governing the design of type-C tanks in liquefied gas carriers. Furthermore, the high strength steel grades intended for this application are known to exhibit a ductile to brittle transition at moderately low temperature, contrary to the materials usually used for transport of liquefied gases which can exhibit a ductile behaviour at very low temperatures. Therefore, in order to quantify the toughness requirements of these high strength steel grades for application on type-C tanks on LCO2 carriers, engineering critical assessment (ECA) have been carried out taking into account various design parameters such as the design pressure, the plate thickness or the stress relief method. In order to allow a continuity with the IGC Code requirements and maintain its inherent safety level, the IGC Code building assumptions were kept whenever possible and complemented otherwise with guidance from BS7910 standard. The analyses allowed defining minimum required CTOD toughness levels and provide useful guidance for steel manufacturers and construction yards for the material selection, the welding procedures and associated NonDestructive Testing procedures.
Numerical Investigation on the Cavitation Evolution and Trajectory Behaviors of High-Speed Oblique Water Entry of Projectiles
Authors: Chang Xing , Xin Jianjian , Chen Weimin
Published: August 2024

The high-speed water entry is of great significance in the development of the cross-media equipment. In this paper, the high-speed oblique water entry of a conical projectile is numerically investigated with particular emphasis on the local fluid field and trajectory behaviors. The numerical model is based on the Reynolds average Navier-Stokes (RANS) method with the Volume of Fluid (VOF) approach for capturing complicated multiphase flow characteristics. The present method is validated against the published experimental data by simulating a case of high-speed oblique water entry. The highspeed oblique water entry of the conical projectile under different impact velocities are investigated. The comprehensive process of the water entry, including the initial impact, formation, development, contraction, closure and collapse of the open cavity, have been reproduced. The flow evolution process of the high-speed water entry, which involves the cavity shape and the cavitation evolution, is analyzed comprehensively. Furthermore, the variation trends of the impulsive load, the projectile attitude and the trajectory stability are examined. The study is expected to enhance the understanding of the cavitation evolution, and is helpful for the design of the cross-media equipment.
Wave Loads on a Hollow Circular Cylinder in Open and Icy Waters
Authors: Li Hongtao , Gedikli Ersegun Deniz , Cheng Zhengshun , Sawamura Junji , Lubbad Raed
Published: August 2024

Arctic offshore structures are subject to combined wave-ice actions. However, the underlying mechanisms governing the interaction between waves ice and these structures remain inadequately understood. Performing well-controlled laboratory experiments is a fundamental approach to acquiring insights into such complicated physical processes.

This paper builds on analyzing the laboratory data that were obtained from the HYDRALAB+ Transnational Access project: Loads on Structure and Waves in Ice (LS-WICE), and studies the inline wave forces on a model-scale, stationary, vertical, semi-submerged, bottomless circular cylindrical shell structure, both with and without the presence of ice. In the experiment, the structure was exposed to unidirectional monochromatic waves with increasing heights at prescribed periods under open-water and ice-infested conditions. In the latter case, the ice field comprised uniformly sized and densely packed rectangular ice floes.

Various data analysis techniques, including Prony, dynamic mode decomposition, fast Fourier transform, Tikhonov regularization-based denoising, and Singular Spectrum Analysis, are applied to obtain a reliable estimate of wave amplitudes and the magnitudes of wave loads.

The experimental results suggest that the wave loads on the hollow cylinder, when surrounded by a fragmented ice cover, decrease by up to 27% in comparison to the ice-free water condition. This reduction results primarily from the attenuation of waves in an ice field.
The Influence of Wave Diffraction on the Motion of a Crew Transfer Vessel Behind a Monopile
Authors: Meyer Jannik , Grotebrune Thilo , Wynants Mareile , Hildebrandt Arndt , Schlurmann Torsten
Published: August 2024

In this experimental study, the incidence of wave diffraction behind monopile foundations and their influence on the motion response of a CTV are investigated. The model tests were conducted in the wave flume Schneiderberg (German: Wellenkanal Schneiderberg, WKS) in a scale of 1/40. The water depth was fixed to 40 m (all following quantities are given in prototype scale). Four sets of tests were conducted: (i) Wave-only tests without vessel or monopile to measure the undisturbed wave, (ii) Vessel-only tests without monopile to measure the reference motion response of the vessel, (iii) monopile-only tests without the vessel to measure the wave field behind the monopile, which will subsequently cause the motion response of the vessel behind the monopile. This is investigated in test set (iv): monopile-vessel tests to measure the motion response of the vessel behind the monopile. Monopiles with different diameters D of 6.4 m, 8 m and 10 m were tested, while the distance between vessel bow and monopile had three fixed values of 10 m, 18 m and 40 m as well. Regular waves with wave periods T between 5 s and 10 s were generated, while the wave height H was set to 1 m, 2 m, and 3 m. The results show that the expected diffraction effects occur behind the monopiles, especially for short period waves and large diameter monopiles, leading to a large diffraction parameter ka. These diffraction effects have a significant influence on the vessel’s motion response. However, further analyses indicate that other hydrodynamic interactions (e.g., vessel’s radiated wave interacts with monopile’s diffracted wave) are important for an accurate prediction of vessel motion during CTV-based maintenance operations. The incorporation of these hydromechanic coupling effects in planning tools as well as real-time systems could lead to an significant increase in technician safety as well as maintenance efficiency.
Validation of a Mooring System With Clump Weights for a Spar Floating Wind Turbine Model Using OpenFAST
Authors: Lopez-Olocco Tomas , González Gutiérrez Leo M. , Thiagarajan Krish
Published: August 2024

This research focuses on analyzing three different mooring systems for a FWT mounted on a spar-buoy platform. Building on an initial realistic two-segment catenary mooring system, we introduce two innovative mooring configurations that incorporate the use of a clump weight at two different locations: one close to the seabed and the other close to the fairlead. The mooring configurations are evaluated under wave-only conditions. To assess these different mooring systems, we conducted 1:47 scale model experiments at the CEHIPAR ocean basin. These experiments are compared with a set of OpenFAST numerical simulations, where MoorDyn is implemented to model the mooring dynamics. The results demonstrate a good agreement of OpenFAST with MoorDyn compared to the experimental data in terms of platform motions, but small differences are found when comparing the mooring tensions. A discussion of the difficulty of scaling the axial stiffness of the line material is presented. With the inclusion of clump weights, the maximum tension in the lines under extreme conditions decreases by around 6% while maximum allowable motion limits remain acceptable. This research contributes significantly to the estimation of the change in FWT sea-keeping performance when these devices are attached to mooring lines.
Embracing Uncertainties: Stochastic Decision-Making in Subsea Pipeline Decommissioning
Authors: Da Silva Távora Giselle , Durange De Carvalho Infante Carlos Eduardo , Ribeiro Nicolosi Eduardo , Violante Ferreira Claudio , Lourenço de Souza Marcelo Igor , Caprace Jean-David
Published: August 2024

As Brazil’s offshore fields age, the need for decommissioning subsea structures is intensifying. While the importance of decommissioning is well understood, the current literature lacks a detailed stochastic approach for the decommissioning of subsea pipelines. This paper fills the gap by presenting a stochastic multi-criteria decision analysis (MCDA) to aid in determining the most appropriate decommissioning option. The method includes a way to handle data variability and incorporates decision-makers’ preferences using MCDA techniques. Through a case study of a rigid pipeline in Brazil’s Cação field, various decommissioning strategies are evaluated against criteria like safety, social, environmental impact, and cost. The study considers various decommissioning alternatives, including leaving the pipeline in place, rock deposition at the pipeline ends, total removal by cutting and lifting sections, and complete removal by reverse reel lay. The study, using Monte Carlo simulations to account for data uncertainties, concludes that leaving the pipeline in place is the preferable choice. This research provides a comprehensive tool for transparent decommissioning decision making in the face of uncertainties, demonstrating its effectiveness in practical scenarios.
Maneuvering Prediction of a Surface Combatant in Calm Water With a CFD-Informed Mathematical Model
Authors: Aram Shawn , Wundrow David W.
Published: August 2024

A modular based mathematical model is adopted to predict the maneuvering performance of surface ships in calm water. The model coefficients are determined from a series of captive model simulations performed with computational fluid dynamics. The accuracy of the mathematical model is evaluated for turning circle and zig-zag maneuvers by comparison against free running model test data and high-fidelity simulations. Reasonable agreement in predicted maneuvering characteristics is obtained between the mathematical model and model test data; 3–5% averaged relative error in trajectory parameters for 25° and 35° turning circle and 20-20 zig-zag maneuvers. Sensitivity of the mathematical model to a set of propeller-rudder interaction parameters is demonstrated by 5–7% deviations about the mean in turning circle characteristics. Sensitivity of the zig-zag maneuver to the interaction parameters is less pronounced. Influence of the propeller side force on the maneuvering performance is examined and over 20% reduction in the steady turn diameter is found in absence of the side force. Importance of the propeller side force in the zig-zag maneuver is also described.