bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Testing to Assess Suitability of Geological Storage Prospects and the Associated Risks of CO2 Hydrates During CO2Injection (III) – Assessment of Thermal Hydrate Inhibitors
Authors: Peat Stephnie , Mehraban Mohammad Fattahi , Boyde Daniel , Frigo Dario Marcello , Graham Gordon , Jellema Raymond , Perez-Fernandez Maria 
Published: June 2023

Abstract
Most emerging techniques for laboratory evaluation of Carbon Capture Utilization and Storage (CCUS) projects refer to traditional geoscience core analysis methods of porosity, permeability, mineralogy caprock integrity, etc. However, analytical programs must go beyond typical oil and gas reservoir evaluation workflows when assessing injectivity impairment and measurements to control it. This work aims to highlight key operational challenges related to CO2 injection into low-pressure target formations and provides a new approach to assessing injectivity impairment caused by CO2 hydrates formation in the near wellbore.
Newly built core flooding apparatus, designed specifically for low temperature conditions, has been used to measure permeability changes during injection of liquid or gaseous carbon dioxide across a range of formation water compositions, fluid saturations, temperatures (-25 °C to + 30 °C) and pressures to demonstrate the effect on injectivity of various formation damage mechanisms, including formation of CO2 hydrates, scale and ice. This work required design of a new test rig and approach for the range of conditions expected in CO2 injection into depressurized hydrocarbon reservoirs (mainly low-pressure gas fields). Controlled, repeatable generation of the damage mechanism is required to evaluate preventative and remediation options, such as chemical inhibitors.
Initial testing of the apparatus involved injection under hydrates-forming conditions by varying pressure while flowing CO2 into a core at various brine saturations, where severe blockages were observed to form. Altering the input parameters, enables the locus of CO2 hydrates to be located in this porous medium as well as determining their formation kinetics and likely plugging mechanism. Reproduction of injectivity impairment under a variety of conditions demonstrated the ability to form, dissipate and re-form hydrates, which then allowed the performance testing of inhibitors, which were shown either to limit or eliminate injectivity impairment. The current paper presents use of the equipment and methodologies to assess the application of the thermodynamic hydrate inhibitor, monoethylene glycol (MEG), to circumvent this impairment and to determine the minimum required dose of the inhibitor to prevent CO2 hydrates within a porous medium. By quantifying the MEG dose requirement in this manner, this hydrates-suppressing chemical can be used either to design well treatments using it either as an inhibitor or for remediation of a partial blockage caused by a CO2 hydrate in the near-wellbore of a CCUS well.
Modelling Drawdown Induced Salt Precipitation in Gas Producing Reservoirs: A Field Case Example
Authors: Ogundipe Oluwatosin Matthew , Mackay Eric James 
Published: June 2023

Abstract
Halite scaling in natural gas production systems may cause formation damage, particularly in zones immediately surrounding the well and perforations. The clogging of flow paths has induced the loss of productivity (and injectivity in CO2 injection wells) and, in some cases, total abandonment of wells. This paper captures the process of drawdown as the main driver of the salt precipitation phenomena under specific field conditions.
Calculations were performed using reactive transport compositional reservoir simulation software to model the impact of drawdown on the change in water solubility in the gas phase during low water-cut gas production in a specific field. 1D and 2D radial models with small near-well blocks and large outer blocks were developed to account for water vaporization at irreducible and mobile water saturations, considering capillary pressure effects (horizontal and vertical imbibition) and gravity segregation. Changes in the values of critical parameters such as absolute permeability, production rate, and initial reservoir pressures were inputted to test their impact on salt precipitation.
Calculations confirm that the steepest pressure gradients occur closest to the wellbore. Consequently, there is an increase in water solubility in the methane as the gas approaches the well, which causes an increase in the rate of evaporation and a greater propensity toward drying out in the near-wellbore region. For the 1D model at irreducible water conditions, the dry-out zone increases as the permeabilities, and initial reservoir pressures decrease. In contrast, there is reduced salt deposition as the production rate is reduced. Under mobile water conditions and horizontal imbibition, the dry-out zone is extended, but only a slight increase in formation damage occurs. Horizontal imbibition causes an increase in pressure gradient because it reduces gas mobility. The Kozeny-Carman porosity-permeability relationship meant a 16% reduction in porosity resulting in a ~35% reduction in permeability near the well. The 2D modelling suggests a similar trend to 1D, but with a much stronger localized effect in the lower parts of the well due to vertical imbibition, resulting in up to 95% porosity loss locally. In contrast to the horizontal imbibition, this is due to the vertical imbibition causing a greater mass of salt to be transported into the dry-out zone.
The information presented in this study provides a platform for operators by which the theory and concepts underlying salt precipitation may be better understood. Improved reservoir management decisions may then be made, and methods of optimally producing the wells in this field could be adequately deployed. Depending on economic considerations, reducing flow rates and managing well bottom hole pressures could be considered, in addition to the application of wash water treatments whilst the problem remains localized.
Lignosulfonate-Based Calcite Scale Inhibitors for Topside and Downhole Applications
Authors: Ganguly Sumit , Kelland Malcolm A , Ellis Ross J , Andresen Martin , Subramanian Sreedhar 
Published: June 2023

Abstract
Scale inhibitors (SI) are widely used in upstream oil and gas industries to prevent insoluble inorganic salts from depositing near or inside the production well or in flow lines. Commercial scale inhibitors like polyacrylates or polyvinylsulfonate offer good calcite scale inhibition, but none of them belong to the PLONOR (PLONOR = Pose Little Or NO Risk) list of oilfield chemicals that can be discharged safely to the environment without any prior measure. Often commercial SIs also have problems like limited Ca-ion compatibility (polyacrylates) or thermal stability (polyaspartates). Sodium lignosulfonates (SLS) fall within the PLONOR list of chemicals but have poor inhibition efficiency towards calcite scaling. When modified by a cost-efficient, and environmentally-friendly method, the lignosulfonates showcased remarkable improvement towards calcite scale inhibition. The modified lignosulfonates achieved a 10-20 fold boost in inhibition efficiency compared to the parent SLS, as measured by a high-pressure dynamic tube blocking scale rig. The modified lignosulfonates also showed an appreciable level of Ca-ion tolerance and retained the same level of efficiency after anaerobic hydrothermal treatment at 130 ºC. In summary, we have developed a range of PLONOR-listed, thermally stable, brine compatible products derived from natural wood, which are suitable for both topside and downhole calcite scale inhibition applications.
Reduce Fresh Water Usage While Mitigating Scale
Authors: Vo Minh , Debenedictis Frances , Spurr Naima 
Published: June 2023

Abstract
Current seawater fluid systems were designed to reduce the usage of fresh water and the number of trips needed to transport the water. The composition of such fluids needed gel stabilizers to reduce the negative effects high salinity waters have on fluid performance. However, in solving one problem, another potential problem may have been overlooked. Sea water when met with the formation waters can cause scale production and formation damage. The damage is often worse when wells are shut in for extended periods of time. This paper will discuss the evaluation of a scale inhibitor package for immediate and long-term scale protection that can be delivered in the seawater fracturing operation without detrimental effects to fluid performance. Traditional and nontraditional screening methods were used to demonstrate the longevity of the scale inhibitor additive. Evaluation studies consisted of inhibitor compatibility studies, static bottle testing, and fluid rheology compatibility testing. Inhibitor compatibility studies were conducted to determine the inhibitors efficacy in high calcium environments at the pH of the fracturing fluid. Static bottle longevity testing was completed over 6 weeks using various inhibitor concentrations to optimize the scale inhibitor loading across varying seawater to formation water ratios. Fluid rheology studies were performed to determine compatibility with the inhibitor.
Various loadings of the scale inhibitor were evaluated to determine the best loading across varying ratios of seawater to formation water. The scale inhibitor demonstrated that it could effectively inhibit calcium and barium scale formation for at least 6 weeks. Results were confirmed with ICP testing showing more than 80% of the cations in solution as per industry standard. The scale inhibitor had no determinantal effects to the fracturing fluid stability compared to the baseline.
The data clearly shows the potential of using a scale inhibitor package with a seawater based fracturing fluid to fracture the formation while simultaneously inhibiting any scale formation. The inhibition was shown to last a minimum of 6 weeks at temperature to simulate shut in.
The novelty of this scale package is to decrease use of fresh water and carbon footprint while providing long term prevention of scale through scale control additives. The optimized fluid and additives can provide enhanced management and protection from damaging scale deposition in HTHP wells later in the life of the well.
Chemical Control of H2S for Unconventional Production: Performance Evaluation of Triazine and Non-Triazine H2S Scavengers in Challenging Environments
Authors: Leach David , Yan Chao , Wang Wei , Wei Wei 
Published: June 2023

Abstract

Objectives/Scope
Production of hydrogen sulfide (H2S) in O&G wells is a major issue for the industry due to concerns about toxicity, corrosion risks, and H2S takeaway limits that can result in well shut-in. One of the primary methods to manage sulfide production is to use H2S scavengers, with triazines being the most common. The scope of this work was to evaluate non-triazine alternative chemistries head-to-head with incumbent products under challenging high H2S and CO2 conditions.

Methods, Procedures, Process
In this study, monoethanolamine (MEA) triazine was tested head-to-head against five alternative chemical products in challenging lab conditions for accelerated product reaction (25 mol % H2S, 16 mol % CO2, balance CH4). Alternatives included an experimental triazine derivative product, an amine/hemiacetal product, a methyleneamine complex product, and two different methylene bis-oxazolidine (MBO) products. Lab performance testing was done by sour gas bubbling through product liquid at a controlled flow rate and ambient pressure and temperature, with constant H2S monitoring until breakthrough and scavenger exhaustion. Scavenger efficiency, process compatibility, pH of scavengers, and solid byproducts were evaluated.

Results, Observations, Conclusions
As expected, MEA triazine showed the highest raw efficiency for H2S consumption. However, under full exhaustion conditions, the standard triazine formulation produced high levels of solid byproducts that could not be dissolved or removed by various solvents, and it showed high pH before and after reaction demonstrating likely incompatibility with field water chemistries. Other products showed promising application-specific advantages: an experimental triazine derivative showed significantly less solids with good scavenging efficiency, and the hemiacetal and methyleneamine products showed almost no solid byproducts and lower impact on scaling risk from reduced pH. Surprisingly, both MBO products showed undesirable performance under high CO2 and H2S conditions tested, with extremely high insoluble solids production (&gt; 6 lbs/gal) containing large amounts of carbon, oxygen, and sulfur. These results provide useful performance knowledge and guidance for optimized usage of H2S scavenger products in field applications, especially in challenging high CO2 production environments.

Novel/Additive Information
This study provided testing methods and novel conditions for triazine and non-triazine H2S scavengers, an area of critical importance for safe and economical management of sour O&G production. Our experiments showed key advantages and limitations of some alternative oilfield chemistries in terms of product efficiency, intractable solids production, and impact on scaling risk. These results underscore the importance of application-specific performance testing to validate chemical solutions for production reliability.
An innovative 3D wave channel design for boosting the dynamic response of proton exchange membrane fuel cell stack
Authors: Fan Zhaohu , Xie Xiaofeng , Fan Zhaohu , Li Zijun 
Published: June 2023

Abstract
The dynamic response of proton exchange membrane fuel cell (PEMFC) is an appropriate metric for evaluating the vehicle’s PEMFC system. In this study, we compare the experimental results of two stacks, each with an effective area of 102.66 cm2 (14.5cm×7.08cm), and bipolar plates featuring parallel two-dimensional straight channel (2D) and three-dimensional wave channel (3D). We specifically investigate the effects of load mode, load change, stoichiometric ratio, temperature, back pressure, and humidity on the output performance of both stacks, using polarization curve and electrochemical impedance spectroscopy (EIS). The 3D wave channel outperforms the 2D straight channel in terms of reaction gas dispersion, enhancement of diffusion and mass transfer to the diffusion layer, reduction of concentration polarization in the PEMFC, and improved self-humidification under low humidity conditions. More importantly, our results show that the implementation of a 3D wave channel results in both an enhanced steady-state performance and improved dynamic response for the PEMFC.
The structural basis for 2’-5’/3’-5’-cGAMP synthesis by cGAS
Authors: Wu Shuai , Gabelli Sandra , Sohn Jungsan 
Published: June 2023

Abstract

Cyclic G/AMP synthase (cGAS) activates innate immune responses against cytosolic double-stranded (ds)DNA. Here, by determining crystal structures of cGAS at various reaction stages, we report a unifying catalytic mechanism. apo-cGAS assumes an ensemble of inactive conformations and binds NTPs nonproductively. Dimerization-coupled dsDNA-binding then affixes the active site into a rigid lock for productive metal•substrate binding. A web-like network of protein•NTP, intra-NTP, and inter-NTP interactions ensures the stepwise synthesis of 2’-5’/3’-5’-linked cGAMP while discriminating against noncognate NTPs and off-pathway intermediates. One divalent metal is sufficient for productive substrate binding, and capturing the second divalent metal is tightly coupled to nucleotide and linkage specificities, a process which Mn2+ is preferred over Mg2+ by 100-fold. Additionally, we elucidate how mouse cGAS achieves more stringent NTP and linkage specificities than human cGAS. Together, our results reveal that an adaptable, yet precise lock-and-key-like mechanism underpins cGAS catalysis.
Study on the Structure Parameters and Design Method Optimization of Blade-Type Screw Steel Pipe Pile
Authors: Zhang Xianjiang , Li Jianhua 
Published: June 2023

Abstract

The rationality of structure parameters of the blade-type screw steel pipe pile is the major factor in determining the safety, applicability and economy of pile foundation, but the existing design methods have not defined the specific approaches to calculate structure parameters of blades and steel pipes. To solve this problem, through the strength theory analysis on spatial helical blades, the ratio a of blade width to steel pipe radius was clarified as the core index to do the structure parameters design of blade-type screw steel pipe pile, and the mathematical calculation model between the vertical bearing capacity of single pile and a was established. By numerical calculation, the rational value of a is 2.0 ~ 3.0. Through the force analysis on the synergy between blades and steel pipes, the correlation between blade thickness and wall thickness of steel pipes was determined and then the structure parameters design method of blade-type screw steel pipe pile with coordinated parameters was proposed. The rationality and superiority of this design method was verified by the comparison between the existing test data and the finite element simulative analysis. Based on this design method and the current specifications such as Technical Code for Building Pile Foundations, a safe, applicable and economical optimization design method and flow of blade-type screw steel pipe piles were further proposed for engineering design reference.
Overhead line insulator defect detection method based on improved YOLOv5s
Authors: Zhang Qiang , Li Shanjie , Li Ying , Feng Dongdong 
Published: June 2023

Abstract
Target defect detection on overhead lines is critical for safe and reliable grid operation. When targeting line images with complex backgrounds, there are significant challenges in detecting defective insulators. A detection model of overhead line insulators with an improved YOLOv5s network is proposed to improve the detection efficiency of target defects. First, MobileNetV3 is used to lighten the YOLOv5s backbone network and reduce the network parameters; second, an improved ASFF adaptive feature fusion structure is used to equalize the inconsistency of different feature layers; then a CBAM attention mechanism is added to the head network to increase the weight of the target information to improve the model accuracy; finally, the edge loss function is adopted as EIOU_Loss loss function, to accelerate the convergence of the network. The experimental results show that the GFLOPs of the improved YOLOv5s algorithm is 11.6G, which is 1.3% higher compared with the YOLOv5s algorithm, and the Map_0.5 is 97%, which is 0.2 percentage point higher than the YOLOv5s algorithm, so the proposed improved YOLOv5s algorithm has higher detection speed while ensuring the model detection accuracy, and can meet the requirements of detection accuracy in light-weight target detection scenarios.
SLIViT: a general AI framework for clinical-feature diagnosis from limited 3D biomedical-imaging data
Authors: Avram Oren , Durmus Berkin , Rakocz Nadav , Corradetti Giulia , An Ulzee , Nitalla Muneeswar , Rudas Ákos , Wakatsuki Yu , Hirabayashi Kazutaka , Velaga Swetha , Tiosano Liran , Corvi Federico , Verma Aditya , Karamat Ayesha , Lindenberg Sophiana , Oncel Deniz , Almidani Louay , Hull Victoria , Fasih-Ahmad Sohaib , Esmaeilkhanian Houri , Wykoff Charles , Rahmani Elior , Arnold Corey , Zhou Bolei , Zaitlen Noah , Gronau Ilan , Sankararaman Sriram , Chiang Jeffrey , Sadda Srinivas , Halperin Eran 
Published: June 2023

Abstract

We present SLIViT, a deep-learning framework that accurately measures disease-related risk factors in volumetric biomedical imaging, such as magnetic resonance imaging (MRI) scans, optical coherence tomography (OCT) scans, and ultrasound videos. To evaluate SLIViT, we applied it to five different datasets of these three different data modalities tackling seven learning tasks (including both classification and regression) and found that it consistently and significantly outperforms domain-specific state-of-the-art models, typically improving performance (ROC AUC or correlation) by 10-40%. Notably, compared to existing approaches, SLIViT can be applied even when only a small number of annotated training samples is available, which is often a constraint in medical applications. When trained on less than 700 annotated volumes, SLIViT obtained accuracy comparable to trained clinical specialists while reducing annotation time by a factor of 5,000 demonstrating its utility to automate and expedite ongoing research and other practical clinical scenarios.
Satellite navigation spoofer localization based on Kalman filter from LEO satellites
Authors: Wang Ying , Yan Tao , Bian Lang , Meng Yansong 
Published: June 2023

Abstract
With the wide application of satellite navigation services, satellite navigation interference has increasingly become an important factor affecting the normal use of user terminals. Research shows that navigation jamming and spoofing have occurred in conflict areas, civil airports and highways. They have affected normal transportation. Because the landing power of the satellite navigation spoofing signal is generally only 3~10dB higher than the normal navigation signal and it is still below the noise, it is difficult to detect spoofing by general methods such as TOA and FOA. In addition, since the navigation spoofer camouflages the Doppler and signal delay of the normal satellite signal, it is difficult for the normal receiver to locate itself normally even if it recognizes the spoofing attack, let alone locate spoofer. This paper proposes a satellite navigation spoofer location method based on Kalman filter from LEO sensing satellites. Using high dynamic LEO sensing satellites, the antenna receives normal GNSS signals and positioning, and another antenna receives spoofer’s signal and positioning. Using Kalman filter combined Doppler and pseudorange measurement, the spoofer’s position and clock offset are estimated. The simulation results show that the accuracy depends on the satellite spatial distribution and clock characteristics of the spoofer.
Awareness of newborn danger signs among mothers of under-9 months old children at Gondar University Comprehensive Specialized Hospital, Northwest Ethiopia, 2022.
Authors: Ayichew Zelalem , Alemnew Wllelign 
Published: June 2023

Abstract
Purpose: This study aims to assess awareness of mothers of under - 9 months old child on newborn danger signs and the associated factors.
Methods: An Institution-based cross-sectional study was conducted in Gondar University Comprehensive Specialized hospital from November 2021 to January; 2022 on 249 mothers. The data were collected using an interviewer-administered questionnaire. Both bivariate and multivariate logistic regression was used to observe the effects of independent variables on the outcome variable.
Result: Out of the 249 participants, only 114 (45.78%) were found to have good knowledge about neonatal danger signs. Mother’s aged 35-49 (AOR =4.69, 95% CI 1.19- 31.85), ability to read and write (AOR =22.19, 95% CI 2.42-202.86) having primary education (AOR= 10.75, 95% CI 1.24- 92.61), being merchant (AOR=3.85, 95% CI 1.12-13.17), parity of 2-4 (AOR =3.53, 95% CI 1.01- 12.32) and >4 (AOR= 24.61, 95% CI 1.87- 322.79) and having information on neonatal danger signs (AOR=3.23, 95% CI 1.57-6.67) were found to be significantly associated with good maternal knowledge of NDS.
Conclusion for practice: The awareness of mothers of under 9-month-old children attending pediatric immunization unit at Gondar University Comprehensive Specialized Hospital on neonatal danger signs is low. Increased maternal age, having formal education, increased parity, and getting information on neonatal danger signs during antenatal care were found to increase awareness. Educating women and providing adequate information on neonatal danger signs during antenatal care (ANC) and post-partum periods can increase their knowledge thereby decreasing neonatal mortality.