bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy and safety of topical finasteride spray solution for male androgenetic alopecia: a phase III, randomized, controlled clinical trial
Authors: Piraccini B.M. , Blume‐Peytavi U. , Scarci F. , Jansat J.M. , Falqués M. , Otero R. , Tamarit M.L. , Galván J. , Tebbs V. , Massana E. ,   the Topical Finasteride Study Group
Published: October 2021

Background

Oral finasteride is a well‐established treatment for men with androgenetic alopecia (AGA), but long‐term therapy is not always acceptable to patients. A topical finasteride formulation has been developed to minimize systemic exposure by acting specifically on hair follicles.

Objectives

To evaluate the efficacy and safety of topical finasteride compared with placebo, and to analyse systemic exposure and overall benefit compared with oral finasteride.

Methods

This randomized, double‐blind, double dummy, parallel‐group, 24‐week study was conducted in adult male outpatients with AGA at 45 sites in Europe. Efficacy and safety were evaluated. Finasteride, testosterone and dihydrotestosterone (DHT) concentrations were measured.

Results

Of 458 randomized patients, 323 completed the study and 446 were evaluated for safety. Change from baseline in target area hair count (TAHC) at week 24 (primary efficacy endpoint) was significantly greater with topical finasteride than placebo (adjusted mean change 20.2 vs. 6.7 hairs; P < 0.001), and numerically similar between topical and oral finasteride. Statistically significant differences favouring topical finasteride over placebo were observed for change from baseline in TAHC at week 12 and investigator‐assessed change from baseline in patient hair growth/loss at week 24. Incidence and type of adverse events, and cause of discontinuation, did not differ meaningfully between topical finasteride and placebo. No serious adverse events were treatment related. As maximum plasma finasteride concentrations were >100 times lower, and reduction from baseline in mean serum DHT concentration was lower (34.5 vs. 55.6%), with topical vs. oral finasteride, there is less likelihood of systemic adverse reactions of a sexual nature related to a decrease in DHT with topical finasteride.

Conclusion

Topical finasteride significantly improves hair count compared to placebo and is well tolerated. Its effect is similar to that of oral finasteride, but with markedly lower systemic exposure and less impact on serum DHT concentrations.
Reference value of hematologic, urologic, and organ weights of 2‐ to 4‐year‐old long‐tailed macaques (Macaca fascicularis fascicularis) in the context of toxicological studies
Authors: Rho Jinhyung , Lee Ju‐Yeon , Yang Mi‐Jin
Published: October 2021

Background

The long‐tailed macaque (Macaca fascicularis fascicularis) is an Old World species, which is one among the most commonly used monkeys for pharmaceutical research. However, most of the available background data are not suitable for good laboratory practice (GLP)‐regulated drug safety tests because the current reverence value covers fewer indices than necessary. Therefore, in this study, historical data for preclinical safety test were collected and managed.

Methods

Twenty‐five hematology, 20 clinical chemistry, 19 urine analysis, and 16 organ weights were evaluated in a drug safety test of 228 male and 140 female 2‐ to 4‐year‐old long‐tailed macaques at the Korea Institute of Toxicology under GLP regulations.

Results

The absolute and relative count of lymphocyte, basophil, and large unstained cell were higher, whereas neutrophil was lower in male than in female monkeys. In serum biochemistry, IP, GGT, ALP, and TCHO of male were higher than female.

Conclusion

Historical data suitable for preclinical safety analysis were determined.
A radical imagination for nursing: Generative insurrection, creative resistance
Authors: Dillard‐Wright Jessica
Published: October 2021

In the crucible of the pandemic, it has never before been clearer that, to ensure the relevance and even the survival of the discipline, nursing must cultivate a radical imagination. In the paper that follows, I trace the imperative for conjuring a radical imagination for nursing. In this fever dream for nursing futures, built on speculative visions of what could be, I draw on anarchist, abolitionist, posthuman, Black feminist, new materialist and other big ideas to plant seeds of generative insurrection and creative resistance. In thinking through a radical imagination, I unpack the significance of reparatory history for nursing, a discipline founded on normative whiteness. From there, I consider what it would take to shift the capitalist frame of healthcare to one of mutual aid, which requires the deep work of abolition. With a radical imagination that breaks down the enclosures that contain us through reparatory history, mutual aid and abolition, kinship becomes urgently possible.
Intermembrane Translocation of Photodynamically Generated Lipid Hydroperoxides: Broadcasting of Redox Damage†
Authors: Girotti Albert W. , Korytowski Witold
Published: October 2021

Lipid hydroperoxides (LOOHs), including cholesterol‐ and phospholipid‐derived species, are reactive intermediates that arise during photosensitized peroxidation of unsaturated lipids in biological membranes. These intermediates may appear in cancer cell membranes during anti‐tumor photodynamic therapy (PDT). Photodynamically generated LOOHs have several different fates, including (a) iron‐catalyzed one‐electron reduction to free radical species which trigger damaging chain peroxidation reactions, (b) selenoperoxidase‐catalyzed two‐electron reduction to redox‐inert alcohols (LOHs), and (c) spontaneous or protein‐mediated translocation to other lipid membrane compartments where (a) or (b) may take place. These different LOOH fates will be described in this review, but with special attention to category (c), which the authors were the first to describe and characterize. Seminal early findings on cholesterol hydroperoxide (ChOOH) translocation and its potential negative consequences will be discussed. In reviewing this work, we wish to congratulate Jean Cadet, for his many outstanding accomplishments as a photobiologist and P&P editor.
Turnover, Loyalty and Competence in the West Wing: The Trump White House in Historical Context
Authors: Dickinson Matthew J. , Reinmuth Kate
Published: October 2021

Pundits and scholars alike point to the high rates of administrative chaos and staff turnover in the Trump White House, but prior research has not been able to pin down the cause(s) empirically. In this paper, we develop a survival model and conduct a Bayesian latent trait analysis to examine the tenure rates of White House aides serving presidents Nixon through Trump. We find that, compared to his presidential predecessors, Trump′s White House stands out for its lack of personally loyal aides. This is not surprising given that his pre‐presidential career would not have allowed him to develop the cadre of political loyalists that typically accompanied his predecessors into the West Wing. Nonetheless, we show that it was this lack of personal loyalty among his staff, and not any shortcoming in competence, that led to high rates of turnover.
Evaluating pole cutting survival and growth for riparian forest restoration during invasion by polyphagous shot hole borer
Authors: Bennett Shelley K. , Lambert Adam M. , Carey Sean P. , Braman Charles A.
Published: October 2021

The investment to restore riparian systems necessitates employing data‐driven planning, implementation, and management. To evaluate the demography/growth of riparian plants established vegetatively, we measured 3 years of survival and biometrics for five tree/shrub species experimentally planted as pole cuttings within a large restoration program in a Mediterranean‐climate riparian system. During the experiment, a recently introduced ambrosia beetle,Euwallacea whitfordiodendrus(polyphagous shot hole borer), colonized pole cuttings, providing an opportunity to evaluate beetle establishment rates among species. Pole cutting survival varied significantly among species and reflected their relative ability to propagate vegetatively.Baccharis salicifoliahad over 90% survival, whileSalix lasiolepisandS. laevigatahad intermediate, andPopulus trichocarpaandP. fremontiihad low survival. Canopy growth reflected species life histories. The small tree/shrub,S. lasiolepis, had robust early growth, while slower growing, larger tree species (S. laevigata,P. trichocarpa, andP. fremontii) filled in canopy later. OnlyS. lasiolepiswas colonized byE. whitfordiodendrusduring the second year and had the greatest infestation rates in all years. All species exceptB. salicifoliawere infested by the third year. Beetles tended to colonize larger trees. Our observed survival and growth trends can serve as a guide for estimating planting density and vegetation structural development over time, and to inform adaptive management of riparian species of Mediterranean‐climate and other arid‐land systems. Ecosystem stressors, such as invasive insects and their impacts to plant growth, must be considered during restoration as introductions are anticipated to continue with increased severity with climate change.
The four novel HLA‐B alleles in unrelated Russian individuals: HLA‐B*38:01:18, ‐B*39:01:28, ‐B*40:484, ‐B*44:498
Authors: Ananeva Anastasiia , Sergeeva Iuliia , Shagimardanova Elena
Published: October 2021

Four new HLA‐B alleles, B*38:01:18, B*39:01:28, B*40:484, and B*44:498, alleles detected in Russian individuals.
Blood component use and injury characteristics of acute trauma patients arriving from the scene of injury or as transfers to a large, mature US Level 1 trauma center serving a large, geographically diverse region
Authors: Liu Zhinan , Ayyagari Rajiv C. , Martinez Monegro Edison Y. , Stansbury Lynn G. , Arbabi Saman , Bulger Eileen M. , Vavilala Monica S. , Hess John R.
Published: October 2021

Background

Advanced trauma care demands the timely availability of hemostatic blood products, posing special challenges for regional systems in geographically diverse areas. We describe acute trauma blood use by transfer status and injury characteristics at a large regional Level 1 trauma center.

Study design and methods

We reviewed Harborview Medical Center (HMC) Trauma Registry, Transfusion Service, and electronic medical records on acute trauma patients for demographics, injury patterns, blood use, and in‐hospital mortality, 2011–2019.

Results

Among 47,471 patients (mean age 45.2 ± 23.0 years; 68.3% male; Injury Severity Score 12.6 ± 11.1), 4.7% died and 8547 (18%) received at least one blood component through HMC. Firearms injuries were the most often transfused (690/2596, 26.6%) and the most urgently (39.9% ≥3 units in <1 h; 40.6% ≥5 units in <4 h), and had the highest mortality (case‐fatality, 12.2%) (all p < .001). From‐scene patients were younger than transfers (42.9 ± 21.0 vs. 47.2 ± 24.4), predominated among firearms injuries (68.2% from‐scene vs. 31.8% transfers), were more likely to receive blood (18.5% vs. 17.6%) more urgently (≥3 units first hour, 24.4% vs. 7.7%; ≥5 units first 4 h: 25.6% vs. 8.2%), were more likely to die of hemorrhage (15.5% vs. 4.3%) and from firearms injuries (310/1360, 22.8%) (all p < .001).

Discussion

Early blood use, firearms injuries, and mortality were all greater among from‐scene patients, and firearms injuries had worse outcomes despite greater and more urgent blood use, but the role of survivor bias for transfer patients must be clarified. Future research must identify strategies for providing local hemostatic transfusion support, particularly for firearms injuries.
Un servicio peligroso. El mito de la brujería y las parteras en Nueva España
Authors: Ortiz Alberto , Ortiz Brenda
Published: October 2021

El presente texto pretende explicar la relación que hay entre la persecución inquisitorial, el mito de la brujería y el oficio de la partería. La época que abarca el virreinato de la Nueva España proporciona los ejemplos para reafirmar los peligros de esta relación cuando la Inquisición se hacía cargo de los casos; dado que el Tribunal del Santo Oficio estuvo interesado en las actividades médicas que parecían peligrosas para el adecuado funcionamiento de la fe y la moral. Obviamente, el oficio de partera ponía a sus practicantes en una situación delicada, tanto por la vinculación con el mito de la brujería como por la competencia contra la medicina autorizada.
De la sodomía a la superstición: el pasivo activo y transgresiones corporales en la Nueva España
Authors: Lewis Laura A.
Published: October 2021

Por medio de documentos primarios y debates académicos, este artículo examina una serie de prácticas en el México colonial que revelan cómo las ideologías de género informaban las políticas de disciplinamiento, así como una serie de comportamientos que iban desde la sexualidad atípica hasta el travestismo y la brujería. De este modo, nos habla de un mundo establecido ambiguamente entre las violaciones de las normas sociales y las incertidumbres de la cultura oficial, ya que examina prácticas heterodoxas, especialmente relacionadas con los indígenas.
Tramas cruzadas en el extraño caso de Juan Luis Martínez
Authors: Gutiérrez Plaza Arturo
Published: October 2021

En este artículo se hace una revisión de algunas tramas cruzadas en la obra de Juan Luis Martínez, particularmente en La nueva novela, relativas específicamente a 1) sus modos de inserción en el campo poético chileno, considerando especialmente las formas en las que se relacionan con las obras de Vicente Huidobro y la Nicanor Parra, que anteceden su obra; 2) sus estrategias de simulación, parodia y ocultamiento de la figura y de la identidad del autor, así como su paradójica vinculación con el legado borgiano; 3) las convergencias y divergencias entre el pensamiento oriental y occidental o la asunción de la imposibilidad del poema: el pajarístico atrapado en la red del ideograma.
Effect of Sucrose Catalyst in the Catalytic Converter on Performance and Emission of Spark Ignition Engine
Authors: Sathyanarayanan S. , Suresh S. , Sridharan M.
Published: October 2021

In this study, experimental attempts were made to reduce exhaust gas toxic emissions from the spark ignition (SI) engine. For this, a sucrose catalyst is coated inside the metallic substrate. The obtained emission level was compared with the results of commercial catalysts for lean-burn operations. The engine was operated at 20%, 40%, 60%, 80%, and 100% loads and the highest NOx conversion efficiency of 60.217% at 40% engine load and 70.732% of hydrocarbon (HC) conversion efficiency at 100% engine load was achieved. Exhaust emissions from the sucrose-coated catalytic converter are observed to be lower than the conventional commercial converter. Also, this paper attempts to predict the emission characteristics of both rigs kept under observation using a fuzzy logic expert system (FLES). Both the input and output responses from the real-time SI engine are used to train and test the proposed FLES. The FLES proposed in this study can predict the emission characteristics of both conventional and sucrose coated catalytic converters with an accuracy of 97%.
Cross-Sectional Design and Case Study for Flexible Pipe
Authors: Zuo Qian , Ali Liaqat , Bai Yong
Published: October 2021

Flexible pipes are compounded by many concentric layers, with different structural and operational functions. These layers are usually made of distinct materials, including metal and plastic. To accurately meet the working requirements of the pipes and reduce its production cost, the primary purpose of this paper is to present the cross-sectional design procedure and the case study for a specific unbonded flexible pipe is also illustrated. In this paper, the mathematical analysis and finite element analysis are employed to study the properties of pipe under different working conditions. A theoretical model for stresses and deformations of the pipe have been studied, and the obtained results have been compared with the ones from the FEM which is used to simulate the pipe under different working conditions. Additionally, the several models will be developed to study mechanical responses of pipes subjected to several loads. The results and FEA models can be useful for the designing structure of flexible pipes.
Initial Design and Analysis of a Compressed Natural Gas Transport System
Authors: Yin Decao , Ludvigsen Halgeir , Lie Halvor , Fylling Ivar
Published: October 2021

Offloading hoses/flexible pipes are used to transfer compressed natural gas (CNG) from an intermediate floating storage and offloading unit (FSO) to CNG vessel (GASVESSEL). The floating hoses are subjected to environmental loads that are mainly waves, current, and vessel motions from both the FSO and the CNG vessel.

Preliminary design of loading/unloading system and dynamic positioning system has been performed. Dynamic analysis of the loading/offloading hose and positioning analysis of the FSO and CNG vessel have been carried out numerically in this study.

It is verified that the designed loading/unloading system and positioning system of the two vessels (FSO and CNG vessel) are able to operate safely under the sea-state Hs = 6 m within the defined ESD1 zone.
Effects of Temperature and Chemical Admixtures on the Properties of Rock-Based Geopolymers Designed for Zonal Isolation and Well Abandonment
Authors: Chamssine Fawzi , Khalifeh Mahmoud , Eid Elsayed , Minde Mona Wetrhus , Saasen Arild
Published: October 2021

In this paper, the impact of temperature and admixture-based salts on the mechanical and rheological properties, and composition of geopolymers was studied. Neat geopolymer and Class-G cement, manufactured by Dyckerhoff, were used as reference samples at elevated temperatures. To enhance the additive properties of the geopolymer slurry, a combination of K and Zn was examined with a variety of K:Zn ratio ranging from ∼0.15 to ∼0.25. The workability of samples was tested by using an atmospheric consistometer, while other rheological properties were examined by running fluid loss test, and rotational viscometer test. The sample with the best workability was cured for 1, 3, and 7 days at bottomhole static temperatures of 70 and 80°C and pressure of 140 MPa where the mechanical properties were examined by ultrasonic cement analyzer and uniaxial compressive strength test. X-ray diffraction was used to analyze the composition of samples at different curing times and temperatures.

The obtained results showed that the salt derivative admixtures have a significant impact on the oligomerization and polycondensation phases, where it distinctively elongated the setting time, enhanced strength, and strength development. On the other hand, the temperature effect was clearly observed by reducing rheological properties, while maintaining similar mechanical properties.
Use of a Transient Model for Studying Kick Migration Velocities and Build-Up Pressures in a Closed Well
Authors: Ngoc Tat Thea Hang , Gomes Dalila , Fjelde Kjell Kåre
Published: October 2021

The objective of the paper is to show that using pressure build-up curves for estimating kick migration velocities can be unreliable. This will be demonstrated by using a transient flow model where different flow patterns including suspended gas are considered. Suspended gas will occur in Non-Newtonian drilling fluids. This can also be the reason why there is reported large discrepancies in literature about what the gas kick migration velocities can be.

A transient flow model based on the drift flux model supplemented with a gas slip relation will be used. The model will be solved by an explicit numerical scheme where numerical diffusion has been reduced. Different flow patterns are included i.e. suspended gas, bubble flow, slug flow and transition to one-phase gas. Kick migration in a closed well will be studied to study how pressure build-ups evolve. A sensitivity analysis will be performed varying kick sizes, suspension limits and changing the transition intervals between the flow patterns.

It is seen in literature that the slope of the pressure build-up for a migrating kick in a closed well has been used for estimating what the kick velocity is. It has been reported earlier that this can be an unreliable approach.

In the simulation study, it is clearly demonstrated that the suspension effect will have a significant impact of reducing the slopes of the pressure build-ups from the start of the kick onset. In some severe cases, the pressure builds up but then it reaches a stable pressure quite early. In these cases, the kick has stopped migrating in the well. However, in the cases where the kicks are still migrating, it seems that the bulk of the kick moves at the same velocity even though the degree of suspension is varied and gives different slopes for the pressure build-up. Hence, it seems impossible to deduce a unique gas velocity from different pressure build-up slopes. However, abrupt changes in the slope of the pressure build-up indicate flow pattern transitions.
The Impacts of Climate Change on the Windows of Offshore Operations
Authors: Acton Caroline
Published: October 2021

Ocean renewable energy has a central role to play in decarbonizing the global energy system. The emergence of new technologies such as floating wind farms will significantly increase offshore wind deployment by providing access to large areas of the seabed that are not suitable for fixed bottom turbines. Operations and Maintenance (O&M) is estimated to contribute 50% to an offshore wind farm’s total operational cost. The ability to improve the efficiency of O&M activities will enable offshore wind to compete with traditional fossil-based and onshore-renewable generation methods. To achieve this, an accurate characterization of the metocean environment is a mechanism of reducing delays and costs across the entire project lifecycle. One of the most significant costs associated with offshore operations is accessing a site with vessels. Site access is determined using vessels constraints in the maximum allowable meteorological and ocean (metocean) conditions and is defined as weather window analysis. However, industry guidelines and standards rely on historical data and do not consider the impact of climate change on the marine climate and the associated vessel operability. This requires the use of climate projection data. The opportunity to use an existing industry metric such as weather windows will tailor the climate projection data to the end-users needs. This paper’s findings suggest that climate change will alter the metocean environment and vessel operability for the case study location investigated. The findings demonstrate the value of site-specific assessment of the future wave climate to inform operational decision making. The main conclusion is that longer-term planning will require the offshore wind sector to consider the impact of climate change on O&M activities.
Underdeck Wave Slamming Model Tests for a Drilling Semi-Submersible Unit
Authors: Xu Lixin , Teng Xiaoqing , Wang Jinguang , Lee Sing-Kwan , Liu Jiancheng , Guo Yinghao , Xiao Longfei
Published: October 2021

Negative air gap and wave slamming load on the deck box of drilling semi-submersible units in severe storm have received a great deal of attention, due to the COSL Innovator accident in 2015. Equally important is vertical slamming load on the MODU underdeck, which is less reported in the literature. The present paper attempts to derive characteristic vertical slamming pressure on the deck bottom, based on an extensive model test program for a drilling semi-submersible unit, CM-SD1000.

A total of 96 3-hour wave impact tests were conducted including 4 sea states selected along the DNV steepness criterion curve in 3 wave headings. Two critical sea states were identified and each was tested with 16 random realizations in both the head and the beam waves. 8 force panels were installed on the under-deck to capture vertical wave impact events. It is found that the peak slamming pressures obtained can be fitted well with both Weibull and Gumbel probability function. The extreme vertical impact pressure predicted are of the same order of magnitude as the extreme horizontal impact pressure.

The present study also shows that rise velocities of the wave surface relative to the deck bottom have a remarkable correlation with the wave slamming pressure in terms of probability distribution. The relative rise velocities can be properly derived from wave probe measurements. This offers an alternative approach to estimate the vertical impact pressure without resort to force panels.

In contrast to horizontal wave slamming, the magnitude and frequency of vertical ones simply increases with significant wave height and wave steepness has much less effect. It is found that the extreme vertical impact pressure can be approximated well by a linear function of the significant wave height. The linear relationship, if validated by more tests, may help evaluate structural strength of the deck bottom before wave basin model testing.
Numerical Simulation of Model Test in Pre-Sawn Ice by CFD-DEM Coupled Method
Authors: Seo Dong Cheol , Wang Jungyong
Published: October 2021

Arctic shipping activities have been steadily increased due to global warming and economic benefit. As a result, there are more demands to estimate the ship performance in various ice conditions at the early design stage. In this paper, a CFD-DEM coupled approach was applied to estimate the ice resistance and broken ice behavior around the hull including hydrodynamic interactions. For the simulation, the moving ship in the stationary ice field was implemented using the overset grid technique. The estimated ice resistance as well as ice behaviors around the hull from the simulations were compared with model test results and underwater videos of the same vessel in a similar ice condition. The results demonstrated good agreement with model test measurements and further improvement for actual application was discussed in the paper.
Condition Monitoring of Ship Propulsion Systems: State-of-the-Art, Development Trend and Role of Digital Twin
Authors: Nejad Amir R. , Purcell Etienne , Valavi Mostafa , Hudak Roman , Lehmann Benjamin , Gutiérrez Guzmán Francisco , Behrendt Felix , Bõhm Angelo Mario , von Bock und Polach Franz , Nickerson Brendon M. , Bekker Anriëtte , Drazyk Withold
Published: October 2021

This paper describes the current implementations and development trends of condition monitoring as it pertains to ship propulsion systems. In terms of total incidents in the shipping industry in the last five years, failures relating to the propulsion system represent the majority. Condition monitoring offers effective early detection of failure which translates to increased reliability and decreased maintenance costs. Current industrial practices are often limited to performance monitoring rather than condition monitoring. Special focus is afforded to how condition monitoring is implemented on board ships, which regulatory codes are relevant and the summary of state-of-the-art research in marine machinery. Moreover, operation and monitoring in extreme environmental conditions, such as the Arctic and Antarctic with ice impact on the propulsion has been discussed. The new developments, in particular, digital twin approaches in health and condition monitoring have been highlighted, considering its pros and cons and potential challenges.
On the Role That the End Shape of an Underwater Vehicle Plays on Wave-Induced Heave Forces
Authors: Suriben Kristia M. , Klamo Joseph T. , Yeager Kathryn I. , Kwon Young W.
Published: October 2021

This paper investigates the error incurred by predicting the wave-induced heave forces on a submerged body using a mathematically simple flat face bow and stern rather than the typical curved ones. We examine both theoretically and experimentally how the heave force changes when flat end faces replace hemispheric end caps. We consider bodies with various length-to-diameter ratios to identify the influence that the ratio of the end cap length to the total body length plays on the heave forces. We also consider bodies with forward speed to identify if heave forces are affected by leading edge separation around the blunt front face which is not present for the hemispheric end cap. The theoretical predictions are from an existing potential flow analytical solution while the experimental results were collected in a towing tank with wavemaking capability. The theoretically predicted percent increase in the heave forces caused by the flat end face was confirmed by the experimental results. Finally, the theoretical predictions also showed that the percent increase in the heave force is independent of the forward speed of the body. This was also confirmed with the experimental results.
A Concept for Floating Offshore Wind Mooring System Integrity Management Based on Monitoring, Digital Twin and Control Technologies
Authors: Puras Trueba Alberto , Fernández Jonathan , Garrido-Mendoza Carlos A. , La Grotta Alessandro , Basurko Jon , Fonseca Nuno , Arrabi Iratxe , Savenije Feike , Pourmand Payam
Published: October 2021

Efficient operation of mooring systems is of paramount importance to reduce floating offshore wind (FOW) energy costs. MooringSense is an R&D project which explores digitization to enable the implementation of more efficient integrity management strategies (IMS) for FOW mooring systems. In this work, the MooringSense concept is presented. It includes the development of several enablers such as a mooring system digital twin, a smart motion sensor, a structural health monitoring (SHM) system and control strategies at the individual turbine and farm levels. The core of the digital twin (DT) is a high-fidelity fully coupled numerical model which integrates simulation tools to allow predictive operation and maintenance (O&M). Relevant parameters of the coupled model are updated as physical properties evolve due to damages or degradation. The DT assimilates information coming from the physical asset and environmental sensors. Besides, a smart motion sensor provides feedback of the attitude, position, and velocity of the floater to allow the computation of virtual loads in the mooring lines, the detection of damages by the SHM system and the implementation of closed-loop control strategies. Finally, the IMS takes advantage of the mooring system updated condition information to optimize O&M, reduce costs and increase energy production.
A Numerical Study of the Hydrodynamics of an Offshore Fish Farm Using REEF3D
Authors: Wang Gang , Martin Tobias , Huang Liuyi , Bihs Hans
Published: October 2021

In this paper, the CFD framework REEF3D is utilized to investigate the hydrodynamics of a large offshore fish farm in waves. The solver consists of a rigid body dynamics solver for the frame structure coupled to a fluid solver including the shielding effects of the nets. The solver and the grid independence are validated using a 2D numerical wave tank, a free decay test, and a study of the wave loads on a rigid net panel. Then, the effects of regular wave parameters, the thickness of the vertical outer columns of the structure, and varies aspect ratios on the loads, response and maximum mooring tensions are investigated. It is concluded that the response is sensitive to the wave period rather than the wave height and that the net system accounts for about 30% of the total drag but does not influence the structural response to a larger extend. The effect of the aspect ratio on the hydrodynamics is more distinct than that of the frame thickness especially. Thus, the first step towards a systemic evaluation of the importance of different structural parts of an offshore fish cage for the expected responses is presented in this paper.
Numerical Simulation of Wave Interaction With a Pair of Fixed Large Tandem Cylinders Subjected to Regular, Non-Breaking Waves
Authors: Mohseni M. , Guedes Soares C.
Published: October 2021

The wave interaction with cylinders placed in proximity results in significant modification of the wave field, wave-induced processes, and wave loading. The evaluation of such a complex wave regime and accurate assessment of the wave loading requires an efficient and accurate numerical model. Concerning the wave scattering types identified by Swan et al. (2015) and lateral progressive edge waves, this paper presents the application of a two-phase Computational Fluid Dynamics (CFD) model to carry out a detailed investigation of nonlinear wave field surrounding a pair of columns placed in the tandem arrangement in the direction of wave propagation and corresponding harmonics. The numerical analysis is conducted using the Unsteady Reynolds-Averaged Navier-Stokes/VOF model based on the OpenFOAM framework combined with the olaFlow toolbox for wave generation/absorption. For the simulations, the truncated cylinders are assumed vertical and surface piercing with a circular cross-section subjected to regular, non-breaking fifth-order Stokes waves propagating with moderate steepness in deep water. Primarily, the numerical model is validated with experimental data provided by ITTC (OEC)[1] for a single cylinder. Future, the given simulations are conducted for different centre-to-centre distances between the tandem large cylinders. The results show the evolution of a strong wave diffraction pattern and consequently high wave amplification harmonics around cylinders are apparent.
Tank Test and Numerical Simulation of Spar Type Floating OTEC
Authors: Hirao Shunka C. , Umeda Jun , Kokubun Kentaroh , Fujiwara Toshifumi
Published: October 2021

National Maritime Research Institute, NMRI, had been studying the analytical method on safety assessments of floating power generation facilities for ten years more. As a part of these studies, an Ocean Thermal Energy Conversion (OTEC) was also studied in our institute.

The OTEC normally has a very long and thick Cold-Water Pipe (CWP) with an unanchored end to pump up a large amount of cold-water continuously. From the viewpoints of the safety assessments of the OTEC operation, it is noteworthy to confirm the effect of the existing long pipe against a floating unit/body and an effect of internal flowing water. It is necessary, moreover, to consider the Vortex Induced Vibration (VIV) effect for floater motions and structural analysis of the pipe itself and a connecting point of the floating structure.

In this paper, the results of model tests and numerical simulations of a spar type floating OTEC with a single CWP in waves and currents are presented. The CWP model was made of material fitting the scaling law for a planned full scale OTEC. The specific and unique phenomena of the floating OTEC were confirmed from the model test results. Based on the results of the tank tests and the numerical simulations, we confirmed the necessary items and arrangements for safety evaluations. In detail, the internal flow increased the bending moment at the connection point.
Simplified Formulation of Coupled System Between Moored Ship and Elastic Pipe for OTEC Plantship
Authors: Hisamatsu Ryoya , Utsunomiya Tomoaki
Published: October 2021

A commercial-scale Ocean Thermal Energy Conversion (OTEC) floating platform will require a large diameter Cold Water Pipe (CWP) to be attached. Several studies have analyzed the dynamic behavior of the coupled system between the floating platform and the CWP. However, the characteristic of the coupled behavior has not yet been fully understood. This study aims to formulate the coupled system of an OTEC floating plant and simplify the formula to clarify the characteristic of the coupled behavior. The formula is suitable for validation of the numerical simulation results and the preliminary design of an OTEC plant. In the first section of this paper, we derive the equation of motion and equilibrium of the direct moored floating body and an elastic pipe hanged off from the floating body. In the second section, we verify the formula for a 100MW OTEC plantship with 800m length and 12m diameter CWP. The Response Amplitude Operator (RAO) is calculated by solving the equation of motion and statistics responses in 3 hours are compared with a numerical simulation by OrcaFlex. As the result of the comparison, we observed that the present formula is applicable in the early stage of the practical design loop.
Development and Implementation of an Arctic Sea Route Search System
Authors: Sugimura Takeshi , Yamaguchi Hajime , Yabuki Hironori
Published: October 2021

With the reduction in extent of Arctic Ocean sea ice in recent years, commercial use of Arctic Sea shipping routes has attracted increasing attention. An urgent task for promoting the use of safe and cost-efficient routes in the Arctic Sea is the construction of a navigation support system. Such a system is essential not only for monitoring and forecasting the extent of sea ice but also for integrating such information in determination of the optimal route. This research developed an Arctic Sea Route Search System that has been published as a web application on the Arctic Data archive System website. Ship speed is calculated based on an approximate expression of actual Automatic Identification System data and an Ice Index, which is an index that reflects the ease of navigation based on ice type and the ship’s ice class. The A* algorithm searches for the optimal route using a search graph that places nodes at the grid positions of input data. Comparison of several test calculations using different parameters confirmed that the route search system provides reasonable results.
Efficient Calculation of Spatial and Temporal Evolution of Hydrodynamic Loads on Offshore Wind Substructures
Authors: Pakozdi Csaba , Kamath Arun , Wang Weizhi , Martin Tobias , Bihs Hans
Published: October 2021

Estimation of the hydrodynamic loads based on strip theory with the Morrison equation provides a fast and inexpensive method for load estimation for the offshore industry. The advantage of this approach is that it requires only the undisturbed wave kinematics along with inertia and viscous force coefficients. Over the recent years, the development in numerical wave tank simulations makes it possible to simulate nonlinear three-hour sea states, with computational times in the order of real time. This provides an opportunity to calculate loads using wave spectrum input in numerical simulations at reasonable computational time and effort. In the current paper, the open-source fully nonlinear potential flow model REEF3D::FNPF is employed for the wave propagation calculations. Here, the Laplace equation for the velocity potential is solved on a sigma-coordinate mesh with the nonlinear free surface boundary conditions to close the system. A technique to calculate the total acceleration on the sigma-coordinate grid is introduced which makes it possible to apply strip theory in a moving grid framework. With the combination of strip theory and three-hour wave simulations, a unique possibility to estimate the hydrodynamic loads in real time for all discrete positions in space within the domain of the numerical wave tank is presented in this paper. The numerical results for inline forces on an offshore wind mono-pile substructure are compared with measurements, and the new approach shows good agreement.
Validation of Forced Heave Simulations on a Planing Hull
Authors: Husser Nicholas , Judge Carolyn , Brizzolara Stefano
Published: October 2021

Advances in nonlinear modeling techniques have created opportunities for more robust modeling of planing hull dynamics than previous techniques relying on linear assumptions. These techniques rely on the imposition of complex, coupled forced motions on a hull. RANSE CFD provides a distinct advantage over experimentation when imposing complicated forced motions because mechanical limitations of the forced motion mechanism and uncertainty in the prescribed motion are eliminated, though the accuracy of the simulations needs to be validated. In this work, a series of sinusoidal forced heave experiments on a planing craft are used to validate the force response predicted by simulation for the same forced motion. The accuracy of the predicted force response is evaluated relative to the experiments with the experimental setup uncertainty considered. Within the experimental setup uncertainty, the force response is predicted well by RANSE CFD and is found to be reasonably accurate. The dynamic trim angle is found to have a major impact on the dynamic force response with variations on the order of half a degree having substantial impacts on the measured forces.
Experimental Investigation of Large Particle Slurry Transport in Vertically Oscillating Pipe for Subsea Mining
Authors: Masanobu Sotaro , Takano Satoru , Kanada Shigeo , Ono Masao
Published: October 2021

For subsea mining, it is important to predict the pressure loss in oscillating pipes for the safe and reliable operation of ore lifting as well as the design of lifting system. In the present paper, the authors focused on the internal flow in vertical lifting pipe oscillating in the axial direction and carried out slurry transport experiment to investigate the effects of pipe oscillation on the pressure loss. The spherical alumina beads and glass beads were used as the solid particles in the experiment, and the oscillating periods and amplitudes of pipe model as well as the solid concentrations and the mean slurry velocities were varied. The time-averaged components of hydraulic gradient calculated by the prediction method for the steady flow proposed in the past by the authors agreed well with the experimental ones. As for the fluctuating components of hydraulic gradient, the calculation results using a homogeneous mixture model were compared with the experimental data. The comparison result indicated that the homogeneous mixture model would be applicable to the prediction of pressure loss in the vertical pipe oscillating in the axial direction.
Comparison of Fatigue Crack Growth Rates Between Different Specimen Geometries
Authors: Zhang Yan-Hui , Doré Matthew
Published: October 2021

Most engineering components are subjected to cyclic loading in service and design against fatigue failure is often a key consideration in design. For fracture mechanics fatigue analysis, fatigue crack growth (FCG) tests are often required to determine the relevant Paris power law parameters for the material under the environment concerned. Standards allow use of different specimen geometries for FCG tests such as compact tension (CT), centre crack tension (CCT), single edge notch bend (SENB) and single edge notch tension (SENT). However, when selecting specimen geometry for fatigue crack growth rate (FCGR) testing, there is often doubt about which specimen geometry is more appropriate and whether they give similar FCGR. There is limited work to compare the FCGR between different specimen geometries.

This paper first briefly introduces the guidance on FCG test specimen geometries in standards and compares the advantages and disadvantages of these specimen geometries. A comprehensive literature review is carried out to compare the FCGR data between different specimen geometries. FCGR tests are conducted on SENB, SENT and CCT specimens of C-Mn steel to investigate any effects of specimen symmetry/asymmetry and crack constraint on FCGR. Based on the literature review and test data, it is concluded that FCGR is independent of the specimen geometries examined.
Early-Phase Offshore Hydrocarbon Field Planning Considering Environmental Factors and Using Integrated Asset Modeling
Authors: Moon Seok Ki , Stanko Milan
Published: October 2021

This work discusses methods to quantify environmental indicators of development alternatives during the early design phase of offshore fields and how to include them in the selection process.

The goal is to develop a decision-support method to: 1) evaluate field development alternatives of reduced environmental impact and 2) dealing with conflicting indicators such as economic value and environmental performance. A value chain model of a synthetic field located in the Norwegian Continental Shelf (NCS) was created using an integrated asset modeling tool. The model computes the net present value (NPV) of the project and the amount of CO2 emissions based on the hydrocarbon production profile and the field energy consumption.

Several cases and field development power supply alternatives such as open-cycle gas turbine (OCGT), combined-cycle gas turbine (CCGT), power from shore and offshore wind farms are analyzed. It has been assumed that the gas turbine generates most of the CO2 and that the amounts of CO2 produced is a function of the field power consumption. The effect of the CO2 tax is included and studied.

Results show that there are development alternatives that provide fair economic value while having low CO2 emissions. For the cases studied, the solutions with gas turbines have higher economic value than the solutions with power from shore and offshore wind farms, but emit large amounts of CO2. For solutions using gas turbine, a combined-cycle has less CO2 emission intensity (kgCO2/boe) than open-cycle, however, the energy intensity (kWh/boe) depended mainly on the amount of gas recycled and is highest for 75%. These indicators could allow field planners to evaluate and compare different field development concepts. Breakeven values of CO2 tax were determined for which the economic value of development with the gas turbine is equal to that of development with power from shore or offshore wind farms.
Fatigue Reliability-Based Inspection Planning Methodology for Corroded Mooring Chain Links
Authors: Rezende Filipe A. , Simão Marina L. , Gomes Ricardo S. , Videiro Paulo M. , Sagrilo Luis V. S.
Published: October 2021

Mooring systems are responsible to limit the offsets of oil and gas floating production systems due to environmental actions. Therefore, they are extremely important for the overall safety of the floating unit and of the risers system connected to it. Mooring lines are subjected to pre-tension and environmental loads effects and must be designed to comply with the ultimate, accidental and fatigue limit state criteria. In general, floating units mooring lines are composed by a top chain segment, a rope segment, and a bottom chain segment. Most of the accounted failures in mooring lines are related to fatigue damage in the chain links of the top or bottom segments. Material degradation due to corrosion effects plays an important role in this failure mechanism.

Engineering practice usually recommends that a constant corrosion rate model is to be adopted in the design. Periodic inspections are to be carried out in the mooring lines in order to assess the corrosion effects and other issues during the operational life of the floating system. However, corrosion is a complex phenomenon, which behavior is difficult to predict. Adopting a deterministic corrosion rate can lead to non-realistic results, compromising the system safety and the inspection planning.

Therefore, to consider the problem uncertainties and comply with standards guidance, this work proposes a time-dependent fatigue reliability-based method to update the inspection planning using the results of previous inspections. The method is applied in a case study of a corroded chain segment of a mooring line, assuming a continuously-updated corrosion rate model and the S-N curve fatigue approach.

Results show that the proposed method, based on solid safety assumptions, is a feasible and more reasonable way to define inspection dates, avoiding the mooring system to operate in unacceptable levels of risk.