bluuebunny/crossref_metadata_2025_split huggingface dataset:
Circular FPSO for Arctic Deepwater
Authors: Srinivasan Nagan , Sreedhar Meena S. 
Published: December 2011

Abstract
The areas north of the Arctic Circle 66.56 degree North Latitude have significant potential for oil and gas accumulations. This paper presents a state of the art production, drilling and storage facility support circular FPSO structure for the round the year operation for arctic offshore areas in the presence of permanent sea ice and oceanic deeper water depth. The paper addresses the cutting-edge technologies and innovative method to resist the ice sheets and ridges load. Extensive analytical and experimental studies had been conducted to evaluate the applicability of the concept structure for the typical extreme ice and wave loads of the arctic condition and the results are presented. The engineering analyses studied show that the new circular FPSO is meets the arctic class requirement for the round the year operation with self ice braking and station keeping feasibility and is also viable for applications.

Introduction
Circular FPSO for Arctic Deepwater is a high specification to operate, stand by and survive round the year in the arctic during summer and winter storm in water depths of 150 m and above. A self and inherent ice breaking capability is in built in the design of this circular FPSO. It is assumed that influence of an iceberg impacts on the circular FPSO is prevented, or managed or with least impact consequences by disconnecting the risers and mooring system with the help of the turret. The vessel is primarily designed to break ice sheets and ice floes continuously and thus reduces the ice forces on the vessel. The vessel could resist the kinetic energy of the drifting smaller ice bergs by means of the potential energy in mooring line tensioning and by rotating the circular vessel. Arctic developments are by far real challenges with their environment and the state of conditions.

Typical Arctic Requirements
Russia's Gazprom and Rosneft oil companies want to develop the Shtokman gas field in the Barents Sea and the Sakhalin V oil field, respectively. They both are severe arctic conditions during peak winter. Ice as thick as 1-2m may have a speed over 1 m/s with ridges as deep as 25m. In Barents Sea, severe ice bergs may pass through during in-between seasons. The present vessel is designed and shaped for these worst ice conditions in the deep arctic-ocean. Moreover, the Barents Sea with ice environment everywhere around does not have natural light in most days of the year and is generally dark. A round the year drilling and production needs a reliable and risk free vessel to operate in these fields. The non-ship-shaped FPSO is designed with the aim of being self-sufficient in ice breaking capability without the need of significant ice management. The initial design requirement set for this vessel is a severe arctic environment with water depth ranging from 120m to 500m. The lower limit of water depth is determined by the turret mooring system and its ability to disconnect and connect to the vessel.
The Use of PC Ice Rules in Azimuth Thruster Engineering
Authors: Rauti Timo , Lindborg Kurt 
Published: December 2011

Abstract
The number of azimuth thrusters configured for ice conditions is constantly increasing. This is due to the common tendency of widening the range of operation of a particular ship in terms of weather conditions, operating modes and geographical areas to achieve more business opportunities throughout the operating life of the ship. The other major factor is the large potential for oil and gas in the arctic waters. It is also estimated that the number of icebreakers using azimuth propulsion will increase in the near future as the existing fleet will be modernized and new vessels are built.
In general it will be increasingly important to be able to efficiently configure an azimuth thruster for ice operation. This work has to be done before the actual bidding process since in most cases the specification of ice requirements defines the size of the thruster.
Without clear and user friendly classification rules the definition and bidding of the thruster is difficult or even not possible at all. The main ice loads should be definable using simple formulas that contain only few parameters that are related to the thruster itself. These kind rules are very good for the bidding process and the design of a new thruster since very little iteration is needed.
The new PC rules have recently been introduced and that has changed the processes significantly. Although being clearly more accurate, the new rules require much more calculation work and have several parameters related to the thruster itself. This makes the processes considerably more iterative and thereby more time consuming.
The purpose of this presentation is to highlight the practical issues that the new PC rules have brought on. The intention is not to question the scientific content or correctness of the new rules.
Geomechanical Performance Analysis of Potential Long-Term Tests of Gas Production from Hydrate Deposits in North Slope, Alaska
Authors: Rutqvist J. , Moridis G.S. , Kim J. , Reagan M.T. 
Published: December 2011

Abstract
In this study, we analyzed geomechanical responses during potential future long-term tests of gas production from permafrost associated hydrate deposits at Mount Elbert and Prudhoe Bay L-Pad vicinity in North Slope, Alaska. At Mount Elbert we investigated a potential production test from a single 37 ft thick hydrate layer (the Unit D formation) that extends from a depth of 2023 to 2060 ft. At PBU-L106 we analyzed a potential production test within the C-layer, which extends 148 ft from a depth of 2226 to 2374 ft, and is characterized by two hydrate-bearing strata separated by a 30 ft shale interlayer. We use a coupled hydraulic, thermodynamic and geomechanical model simulating 3 years of production from single vertical or horizontal wells (constant pressure Pw = 3 MPa). The analysis shows that most stress changes occurs rapidly (within tens of days) near the wellbore and then progressively away from the wellbore along with the reservoir pressure depletion. Consequently, a few years long test would be sufficient for the stress changes to fully develop and would not change much further around the well bore region, even if the production would be continued for tens of years. The reservoir deformations and surface subsidence on the other hand progresses more gradually with time and is restricted by an arching effect of the overburden. The simulation results show larger subsidence for a production test at Prudhoe Bay L-Pad vicinity, because of a larger hydrate thickness. However, the results indicated about 5 cm compaction of reservoir intervals, which corresponds to a vertical strain of only about 0.2%, and a negligible ground surface subsidence suggesting little danger for the production well and no significant interference with nearby wells and facilities. The results also indicate limited shear failure in the formation around the well perforation which may require appropriate sand screens to prevent solid production.
Development of Performance-Based Testing Specifications for the Arkutun-Dagi Friction Pendulum Bearings
Authors: Fenz D.M. , Reed R. , Slatnick S. , Stewart H.R. , Constantinou M.C. 
Published: December 2011

Abstract
Friction Pendulum bearings (FPBs) are seismic isolation devices that reduce the lateral accelerations of the supported structure in an earthquake. This paper describes the application of probabilistic methods to establish criteria for qualification testing of reduced-size prototype bearings. The methodology is used to determine demands to impose during testing (displacements, velocities, etc.) that are representative of desired performance standards (probabilities of exceedence).
Previous test programs used in the offshore and onshore industry have used deterministic analysis based on lower bound and upper bound properties to establish demands for the test program. These follow from the deterministic analysis approach used in the global structural design. These methods establish maximum demands to target in the test, but do not give information on their actual probabilities of exceedence. Use of the methodology described in this paper allows engineers to test the FPBs at levels having probabilities of exceedence aligned with other major platform components, ensuring that the test conditions are not excessively conservative or unconservative. Rather, the test conditions comply with a specified probability of non performance of 2% in 50 years achieved with a particular level of confidence (90% generally and 99% for more critical parameters).
The performance-based (response-based) approach described in this paper can be applied to a broad range of seismically isolated platforms. These methods were originally developed for onshore seismic design of buildings. Hence, the underlying probabilistic framework is general and can be applied to structural design and qualification testing of other components.

Introduction
Friction Pendulum Bearings (FPBs) are specialized devices that will be used to isolate the topsides of the Arkutun-Dagi platform from earthquakes. The Arkutun-Dagi platform is part of the Sakhalin-I development which is located in an area of high seismicity. Offshore platforms located in the region require highly specialized design to balance the competing requirements of the harsh demands from earthquake, wave and ice loading. Structural design strategies that have been used in the region to protect structures from earthquakes include a tuned mass damper to protect the drilling derrick on the Orlan platform and Friction Pendulum seismic isolation on the Lunskoye-A and Piltun-Astokhskoye-B platforms.
Explosion Safety in Arctic Environment
Authors: Dalheim J. , Nodland S. 
Published: December 2011

Abstract
The harsh environment of the arctic requires specialized safety solutions. An important safety issue in the arctic is the need for additional enclosed modules. Enclosed modules are used to prevent: ice and snow from process equipment; cold climate from imposing an unduly harsh working environment on the operators. Enclosed mechanically ventilated process modules differ from the open naturally ventilated process modules normally used in offshore facilities. The explosion safety performance of the non-standard mechanically ventilated process modules has been studied in detail through an extensive program of CFD simulations. Mechanically ventilated modules have explosion risk drivers distinct from risk drivers in naturally ventilated modules. Significant factors which primarily impact the explosion risk levels on confined process modules are: module size; HVAC philosophy; ignition source isolation efficiency; and the use of pressure relief panels. The impacts of these factors on explosion risk are discussed in this paper, along with significant conclusions to consider with future development in the arctic climatic environment.

Introduction
The primary difference between enclosed and open modules is that any gas leak will be trapped inside the enclosed module. Only the HVAC system can extract the gas from an enclosed module (open module gas leaks can be directed out of the module, with accumulated flammable gas negligible). For all leaks (except smallest) in a confined module, the gas will accumulate relatively fast to flammable concentration levels and greater in large portions of the module. After the leak has stopped and the gas is slowly vented out of the module by the HVAC system, the rich gas will pass through flammable concentrations and form a large flammable gas cloud. This secondary peak of flammable volumes (first peak occurs soon after the leak with the growing gas cloud) is usually significantly larger and persists longer than the first peak. Safety systems which control the transient of the secondary peak (and the ignition intensity in this period) are seen to be significant in controlling the explosion risk.
Assessment of noise levels in 200 Mosques in Riyadh, Saudi Arabia
Authors: Al Shimemeri S A , Patel Chirag B , Abdulrahman Al Fayez 
Published: December 2011

Abstract
Introduction: Noise-induced hearing loss (NIHL) is a recognized concern within the context of occupational and general health. However, noise levels are seldom studied at nonworkplace and nonabode sites that are visited regularly, e.g., places of worship. The purpose of this study was to assess the noise levels inside and outside of mosque prayer rooms and to compare the levels with established noise tolerance limits. Materials and Methods : A portable digital sound level meter was used to determine the noise level (measured in dB) inside and outside of mosque prayer rooms. The highest (peak) and lowest noise levels from each recording were tabulated. Statistical analysis was performed using a two-tailed Student′s t-test(alpha = 0.05). Results : Noise levels were measured at 200 mosque prayer rooms from all 15 municipal districts of Riyadh, Saudi Arabia. Of these, 151 prayer rooms (75.5%) had both inside and outside noise measurements and the remaining 49 prayer rooms (24.5%) had only inside noise measurements. There was significantly greater noise outside compared to inside the prayer rooms, for both the highest noise level (outside: 87.8 ± 4.8 dB compared to inside: 85.8 ± 5.4 dB, P < 0.0001) and lowest noise level (outside: 58.4 ± 3.8 dB compared to inside: 56.6 ± 3.6 dB, P < 0.00001). In all, 112 of the inside highest level measurements (56%) and 113 of the outside highest level measurements (74.8%) were greater than 85 dB, the sound level at which NIHL has been shown to occur in occupational settings. Conclusion : A large proportion (56%) of mosque prayer rooms with inside peak noise measurements were above acceptable levels (85 dB), however, prayers certainly do not last for 8 continuous hours. Therefore, the level of noise at mosques is acceptable and in compliance with international norms of hearing safety; moreover, it does not present any risk to hearing in the long run.
Trending toward gero‐electroceuticals that target membrane potential for reprogramming aging and lifespan
Authors: Tabibzadeh Siamak , Brown Olen R. 
Published: June 2024

AbstractIon gradients across cell membranes generate voltage potentials that are involved in a wide range of biological processes. According to the membrane hypothesis of aging, aging is inextricably linked to a decrease in resting membrane potential (Vmem). Alterations in ion channel activity and membrane fluidity caused by aging disrupt bioelectric homeostasis, increase intracellular calcium and potassium concentrations, induce abnormal mechanistic target of rapamycin (MTOR)‐ and AMPK‐regulated metabolism and energy dissipation, and decrease proliferation and regeneration. Failure to maintain ion channel activity and membrane potential leads to cell senescence or death. There is evidence that by manipulating ion channel activities, a cryptic memory can be recalled to restore lost proliferative or regenerative abilities. Reversal or prevention of senescence, aging phenotypes, and longevity may be achieved by fine‐tuning mitochondrial membrane polarization. Therefore, there is optimism that deciphering the bioelectric codes that govern cell functions will lead to the development of new gero‐electroceuticals that restore cell function and prevent tissue loss during aging.
Self‐Gelling Quinone‐Based Wearable Microbattery
Authors: Bertaglia Thiago , Kerr Emily F. , Sedenho Graziela C. , Wong Andrew A. , Colombo Rafael N. P. , Macedo Lucyano J. A. , Iost Rodrigo M. , Faria Luana C. I. , Lima Filipe C. D. A. , Teobaldo Gabriel B. M. , Oliveira Cristiano L. P. , Aziz Michael J. , Gordon Roy G. , Crespilho Frank N. 
Published: June 2024

AbstractWearable power sources are envisioned since their development promises to speed up the widespread application of wearable devices in different areas, such as healthcare, smart‐city management, and robotics. Here, the 4′‐((9,10‐anthraquinone‐2‐yl)oxy)butyrate (2‐BEAQ), an anthraquinone derivative, is synthesized, and further applied for producing a redox‐active shear‐thinning hydrogel (BEAQ‐gel). The gel comprises cylindrical aggregates of 2‐BEAQ molecules dispersed within a water matrix, interconnected through ionic, ion‐dipole, and hydrogen bonding interactions. BEAQ‐gel also presents interesting rheological characteristics and composition tunability since it can be produced in a large range of concentrations. This improved redox 3D hierarchical network also makes the network capable of retaining high quantities of potassium hydroxide, thereby enhancing conductivity. By coupling BEAQ‐gel with Ferricyanide the development of a wearable battery is demonstrated, which exhibits an output voltage of 0.89 V even when bent at a 180° angle, making it suitable for powering wearable devices. This work presents an innovative alternative for the production of wearable devices, from the design of the anode and cathode materials to the wearable casing and demonstrates the use of redox‐active low‐molecular‐weight‐gel (LMWG) as an active material of a microbattery giving a valuable glimpse to the further development of wearable energy storage devices.
Spatial and Chemical Dual Nano‐Confined Ultrastable Perovskite Quantum Dots Glass Manifesting Exciton Modulation
Authors: Wang Pengwei , Hu Zhiping , Cong Peixi , Zhou Fengxian , Yue Qi , Xue Zixiao , Lin Chenfang , Jiang Ying , Du Juan , Pan Anlian , Zhang Long , Cui Jiabin , He Jin 
Published: June 2024

AbstractNano‐confined synthesis of perovskite quantum dots (QDs) in solid matrix is emerging as a promising route to solve their long‐standing stability problem. Utilizing sol‐gel derived nanoporous glass as matrix that has high flexibility in chemical composition and pore size, a novel spatial and chemical dual nano‐confined strategy is presented for the synthesis of ultrastable perovskite QDs with tunable composition and bandgap in glass. The findings reveal that the Pb─O bonding is formed at perovskite QDs/glass interface during a nano‐confined chemical vapor deposition (CVD) reaction. In particular, the presence of interfacial chemical bonding is discovered to be critical for passivating surface traps and stabilizing the perovskite QDs during the final densification process (related photoluminescence intensity maintained ≈100% after immersed in aqueous solution for 30 days). Series optical spectroscopy unravels the exciton modulation (80 meV) of perovskite QDs in nanoporous and densified glass related to the unique combination of dual physical and chemistry nano‐confined effect. By shedding light on the nano‐confined growth of functional nanocrystals, the research offers the key paths for fabricating high‐performance perovskite devices.
Enhancing Electronic and Magnetic Properties in Eu‐Doped GaN Nanowires via p‐f Hybridization of Eu‐Defect Complexes
Authors: Gudelli Vijay Kumar , Aravindh S Assa , Roqan Iman S. 
Published: June 2024

AbstractDensity functional theory (DFT) is employed based on the generalized gradient approximation (GGA), including the Hubbard (U) parameter, to investigate the modification of the electronic properties of GaN nanowires (NWs) by Eu dopants introduced via Eu‐associated defect complexes to explore the origin of magnetic characteristics. These findings show that incorporating Eu dopants, including Eu‐intrinsic defect complexes, in GaN NWs leads to a significant change in the electronic properties of GaN, as evident from p‐f state hybridization, resulting in unique magnetic characteristics. However, while Ga‐vacancies (VGa) in Eu‐doped GaN NWs impart a significant magnetic moment on N atoms, N‐vacancies (VN) produce a negligible effect on the magnetic properties of NWs. To predict the magnetic exchange effect, two Eu3+ ions are introduced in the NWs, showing that the complex with two Eu atoms and Ga‐vacancy (2Eu‐VGa) induces stable ferromagnetism above room temperature.
Photochemical Action Plots Map Orthogonal Reactivity in Photochemical Release Systems
Authors: Michenfelder Rita T. , Pashley‐Johnson Fred , Guschin Viktor , Delafresnaye Laura , Truong Vinh X. , Wagenknecht Hans‐Achim , Barner‐Kowollik Christopher 
Published: June 2024

AbstractThe wavelength‐by‐wavelength resolved photoreactivity of two photo‐caged carboxylic acids, i. e. 7‐(diethylamino)‐coumarin‐ and 3‐perylene‐modified substrates, is investigated via photochemical action plots. The observed wavelength‐dependent reactivity of the chromophores is contrasted with their absorption profile. The photochemical action plots reveal a remarkable mismatch between the maximum reactivity and the absorbance. Through the action plot data, the study is able to uncover photochemical reactivity maxima at longer and shorter wavelengths, where the molar absorptivity of the chromophores is strongly reduced. Finally, the laser experiments are translated to light emitting diode (LED) irradiation and show efficient visible‐light‐induced release in a near fully wavelength‐orthogonal, sequence‐independent fashion (λLED1 = 405 nm, λLED2 = 505 nm) with both chromophores in the same reaction solution. The herein pioneered wavelength orthogonal release systems open an avenue for releasing two different molecular cargos with visible light in a fully orthogonal fashion.
Stabilized Carbon‐Centered Radical‐Mediated Carbosulfenylation of Styrenes: Modular Synthesis of Sulfur‐Containing Glycine and Peptide Derivatives
Authors: Yang Zihui , Liu Jia , Xie Lan‐Gui 
Published: June 2024

AbstractSulfur‐containing amino acids and peptides play critical roles in organisms. Thiol‐ene reactions between the thiol residues of L‐cysteine and the alkenyl fragments in the designed coupling partners serve as primary tools for constructing C─S bonds in the synthesis of unnatural sulfur‐containing amino acid derivatives. These reactions are favored due to the preference for hydrogen transfer from thiol to β‐sulfanyl carbon radical intermediates. In this paper, the study proposes utilizing carbon‐centered radicals stabilized by the capto‐dative effect, generated under photocatalytic conditions from N–aryl glycine derivatives. The aim is to compete with the thiol hydrogen, enabling radical C─C bond formation with β‐sulfanyl carbon radicals. This protocol is robust in the presence of air and water, offers significant potential as a modular and efficient platform for synthesizing sulfur‐containing amino acids and modifying peptides, particularly with abundant disulfides and styrenes.
Regulating Water Activity for All‐Climate Aqueous Zinc‐Ion Batteries
Authors: Wang Yifan , Mo Li'e , Zhang Xianxi , Ren Yingke , Wei Tingting , He Yi , Huang Yang , Zhang Hong , Tan Peng , Li Zhaoqian , Zhou Jiang , Hu Linhua 
Published: June 2024

AbstractSuppressing the water activity is challenging to achieve high‐performing aqueous zinc ion batteries (AZIBs), especially for its practical climate adaptability. Reconstructing the H‐bond network and repealing the solvation water can effectively reinforce the covalency inside water molecular. Here, a hydrogel electrolyte formula utilizing ClO4− anions and hydrophilic ─NH2 on polyacrylamide chains is shown to bond with water molecules, while the zincophilic glucose preferentially regulate Zn2+ solvation. The multifunctional hydrogel structure can effectively disrupt the intrinsic H‐bond network and inhibit the interface side‐reactions induced by active water. Finally, the delayed freezing point and expanded voltage stability window are realized, which promotes the ZIBs steady operate in a wide temperature range. When operating at 70 and −30 ˚C, the Zn//NVO battery achieves high specific capacity of 488 and 254 mAh g−1, respectively, surpassing most of the previously reported results. Remarkably, the pouch battery delivers the state‐of‐the‐art specific capacity of 438.1 mAh g−1 and realizes a capacity retention of 76.3% after 400 cycles at 200 mA g−1.