bluuebunny/crossref_metadata_2025 huggingface dataset:
From Enabling to Optimizing with Controlled Mud Level MPD
Authors: Lutnes S. , Lasrado A. G.
Published: August 2024

The Controlled Mud Level (CML) MPD technique is described focusing on the development of its utilization. Initially CML MPD was used as an enabling technology holding a Constant Bottom Hole Pressure (CBHP) to "Drill the Undrillable" and to manage losses by adjusting the fluid level according to actual well conditions. Today, the approach is more based upon reducing well cost, improving safety, and increasing production.

The CML method creates a dual gradient effect when lowering the riser level. By moving the hydrostatic column towards the seabed, the pressure profiles are lower at shallow depths and increasing towards sectional TD following the same trend common for operating windows. Utilizing this effect enables longer sections to be drilled within narrow, or even negative, margins - in some cases even when drilling conventionally. The result can reduce the number of sections required in well design, thus reducing the well cost.

A CML system can use the riser as the trip tank for instant notification of volume changes in the well. Keeping the fluid level below the telescopic joint eliminates effects from rig motion. The detection sensors are positioned subsea providing earlier and clearer notification of volume changes. In addition to the volume control for all operations, tripping in and out also becomes a safer and faster process without spending time on displacements, by adjusting the riser level to mitigate the surge and swab effect.

For depleted reservoirs the drilling approach can start holding the initial virgin pressure and then reduce the wellbore pressure according to the actual degree of depletion. Managed Pressure Gravel Pack has become an established approach ensuring the Alpha and Beta waves go all the way from the toe to the heel without inducing losses. Improving the completion methods and optimizing the execution leads to better production.

The development has progressed to where wells are being planned with CML for purposes beyond the CBHP approach. It is used actively in conventional drilling for regular tasks to optimize operations and enhance safety. Since the CML method enables pressure management regardless of pipe size it is utilized for running casings, wireline operations and completion.

This paper describes the methodology of the CML technique and refers to field cases to exemplify how this method is used for extending sections, tripping safer and faster, and increasing production through Managed Pressure Completion.
Embracing the Plug and Abandonment Challenge in Deepwater Malaysia
Authors: Samuel E. , Lee C. H. , Selamat K. , Nopsiri N. , Chan L. , Tan K. M. , Caldow S. , Faiz A. , Idris S. , Singh K. , Woods J. , Khong C. K. , Nicholas L. , Alias S.
Published: August 2024

As oil and gas fields near the end of their productive life, the focus shifts towards decommissioning facilities and ensuring permanent well abandonment. The primary objective of permanent abandonment (P&A) is to securely isolate potential flow of hydrocarbon sources, with no intention of resuming well activities. Operators face numerous challenges in fulfilling this objective, particularly as the wellbore conditions towards the end of a well's life introduce many uncertainties. Issues such as aging facilities, reduced internal diameters due to corrosion and previous sand production, derated equipment tensile strength, and deteriorated well barriers significantly complicate the P&A operations. Moreover, the industry has witnessed stringent regulations for well P&A over the past few years, amplifying the cost of regulatory-compliant P&A execution. Another dimension of the P&A complexity is the growing competition for resources and qualified personnel between the worldwide growing P&A scopes and the continuous wells development programs. With all these concerns, selecting the appropriate P&A techniques and implementing contingencies to ensure uninterrupted progress while performing a P&A operation is crucial.

PTTEP Malaysia has deepwater wells as part of the existing asset portfolio, and some of these wells near the end of their life cycle, the challenge of devising and executing an efficient P&A program for a deepwater environment has been undertaken. This paper aims to delve into the intricacies of designing a deepwater P&A program, exploring potential uncertainties, and outlining necessary contingencies for a successful permanent abandonment. The paper also shed light on the operational strategies employed by PTTEP Malaysia during the execution of the first deepwater well P&A in Sabah waters. This includes discussions on tubing intervention techniques, validation of cement bonds, characterization of behind-casing fluids, management of fluid compatibility, and the establishment of well barriers in alignment with local and international regulations. Furthermore, it will analyze lessons learned and identify areas for improvement to foster continuous learning for future guidance.
Pinocchio Tool as an Innovative Approach of Reactivating Idle Wells With Partially-Open SCSSV Flapper
Authors: Abdillah Mohammad Izzatul Akmal , Ho Yap Yin , Dasan Larissa Manyie , Leong Chua Hing , Mokhtar Mohd Khaidir Bin Mohd , Xiong Choi Yee
Published: August 2024

The Pinocchio Tool is an innovative quick fix in reactivation of idle wells with partially open TR-SCSSV flapper, specifically for cases where the flapper is unable to be opened due to unidentified hindrance accumulating behind the flapper. The Pinocchio Tool methodology has been proven to be a success from a recently completed idle well reactivation campaign.

The Pinocchio Tool was an idea that stemmed out from a problematic well with TR-SCSSV issue whereby the flapper was unable to be operated due to two-way leak in its control line, and further diagnosis indicated that the flapper was only partially opened due to mechanical hindrance behind the flapper. Cycling tests and lock open had been attempted to no success. Prior to resorting to large-scale solutions such as CTU/Eline milling, the team came up with the Pinocchio Tool - a steel device that mechanically pushes down and holds open the flapper, allowing hydrocarbon from the well to flow through. The design of the tool consists of a thin prong extending from a larger-OD body made up of four hollow sections. The prong pushes and holds open the flapper down, while the upper body connects to an installation extension (of matching design as the existing upper completion) and set with a standard lock mandrel. Well barrier, at the absence of a SCSSV, is then established with a nipple-less storm choke.

Upon installation of the Pinocchio Tool, the well was able to flow as per desired parameter. This has proven the tool to be a reliable temporary fix for wells with similar problems while detailed plannings can be done for the more resource-heavy solutions such as CTU, e-line or workover, preventing prolonged close-in of the affected wells - safeguarding both process safety and business needs.

The Pinocchio Tool is the first in the world of its kind - an effective simple solution which only requires minimal fabrication and deployment via slickline.
Contractor Ownership of MPD Systems to Increase Availability and Use of MPD Methods
Authors: Johnson A. , Fraczek J.
Published: August 2024

Objectives/Scope

The goal of this paper is to provide a detailed analysis of factors affecting the permanent integration of managed pressure drilling (MPD) on jackup rigs. This paper highlights approaches that have eliminated or reduced barriers to adoption and improved the availability and use of MPD methods in deepwater and jackup drilling operations.

Methods, Procedures, Process

This paper assesses a variety of factors affecting the permanent adoption of MPD on jackup rigs. The paper begins with an overview of MPD adoption offshore in shallow and deepwater environments. Factors impacting the decision to permanently install MPD on deepwater versus jackup rigs are discussed. The focus of the paper then shifts to the factors affecting utilization of MPD including user mindsets regarding when and how to apply MPD. Finally, solutions to remove the barriers to MPD use are discussed, particularly relating to crew competencies, equipment readiness, and retention of best practices.

Results, Observations, Conclusions

Early on, the availability of MPD services allowed operators to reach through extremely narrow drilling windows to targets that would not otherwise be technically or economically feasible. Today, MPD has grown beyond the initial foothold and is increasingly used to improve drilling performance even in less challenging well sections. In deepwater, several wells have been drilled using MPD to avoid contingencies in applications where the drilling window does not necessarily require MPD. In other deepwater wells, ready availability has enabled operators to reach difficult targets by turning on the MPD system even on a very short-term basis. A shift toward contractor ownership of MPD systems has made many of these cases possible, but this trend has been slower to develop in the jackup segment. There, key constraints must be addressed such as aligning competencies between MPD and rig crews, retaining best practices, ensuring a favorable balance of tradeoffs, and enabling a greater degree of equipment utilization for non-MPD applications. Early results with contractor-owned MPD systems show permanently integrated MPD is possible in the jackup segment and that contractors enhance the overall MPD service when given the right tools and know-how.

Novel/Additive Information

Mindsets around MPD are a key factor affecting permanent integration. Attitudes on utilization represent one facet of a mindset. Some MPD users may use it often, while others use it only in certain cases. These may be described on a spectrum as high-utilization and low-utilization mindsets. Both are MPD promoters in different ways. Mindsets may shift with new technology, moving a user from one mindset to another.
Non-Explosive Tubing Puncher for Well Plug and Abandonment Operation
Authors: Panoot S. , Marut D.
Published: August 2024

This paper details the inaugural implementation of a novel non-explosive tubing puncher in well plug and abandonment (P&A) operations in Thailand, marking a significant evolution in operational safety by circumventing the use of explosives. The industry's historical reliance on non-explosive punchers, while reducing explosive risks, faced limitations in efficiency, flow area capabilities, and need the electric line units. Addressing these constraints, the new technology puncher integrates a hydraulic press system with electronic control powered by an alkaline battery, enabling slickline operations and negating the need for electric lines.

The tool's multi-punch head design introduces unparalleled flexibility, allowing for the adjustment of the flow area and punch hole phasing. This precision is achieved through an activated battery triggered by slickline motion, initiating the puncher's function and ensuring completion within a predefined timeline. Operational risk and the necessity for stringent personal zone management are drastically reduced, streamlining the P&A process. The non-explosive puncher requires approximately 40 minutes at punch depth, with reduced surface preparation time, offering a competitive overall operation duration compared to traditional methods.

Notably, the cement pumping operations through six of 0.5-inch punch holes align with the flow area specifications of explosive punchers, maintaining standard pumping rates and pressures across variable well depths. The barrier integrity, rigorously tested, met industry standards throughout the trials.

The introduction of this advanced non-explosive puncher signifies a breakthrough in safety and operational efficiency. It enhances personnel safety by facilitating offline tubing punch activities, thereby simplifying the P&A process. This innovative approach not only reduces operational risks but also represents a paradigm shift in well abandonment methodology, contributing significantly to the body of knowledge in P&A operations.
Novel Downhole Annular Barrier Solution for Water Shut Off – Kuwait Case Study
Authors: Koch Jonathan , Al-Gharib Majed , Al-Ajmi Ali , Olsen Jonathan Eugen , Leiknes Tom-Morten , Al-Harbi Majed
Published: August 2024

Globally, significant numbers of wells are impaired by poor cement quality in well annuli leading to inadequate sealing of zones and reduced well integrity. Subsequent undesired flow in well annuli such as from connected water sources can result in both significant "locked in" production potential and environmental risk. Downhole Annular Barrier (DAB) (or Downhole Annular Repair (DAR)) systems can be employed via well intervention to correct integrity and conformance control issues and extend the productive life of wells in a safe and cost-effective manner. New and emergent DAB technologies can provide novel solutions to difficult well annuli problems, where traditional remediation solutions such as annular remedial cementing would not be appropriate, efficient, or otherwise have a low chance of success.

This paper will review the planning and successful execution of one such novel DAB intervention by Kuwait Oil Company (KOC) for Water Shut Off (WSO) in an onshore conventional oil well. The intervention objective was isolation of the poorly cemented casing / wellbore annulus to prevent, or significantly reduce, water flow due to OWC (Oil Water Contact) rising across the open production perforations. WSO was successfully achieved utilizing the pinpoint injected resin technology. This technology entailed injecting epoxy resin into the annular space at desired isolation depth, forming a 360-degree pressure barrier. This was world's first application of the service company product technology (CS) for WSO in a sandstone oil well.
Novel Cementing Technology for Deep Water Development Wells in South China Sea
Authors: Zhang H. , Cui C. , Feng Y. T. , Qi Y. , Li Y. , Wang Y. W. , Wen D. Y. , Zhang F. M. , Tian J. , Huang F. , Feng Q. H. , Chen Z. M. , Tang Y. T. , Zhao J. , Zhao H. , Xiao W. , Yu B. , Fang E. L. , Dai D.
Published: August 2024

In South China Sea Block X, a deep water promising gas reservoir more than 100 billion m3 was discovered. Unlike onshore or shallow water wells, cementing operations in deep water development wells face tougher challenges. Low temperature and shallow hazards limit conventional cement slurries, especially when these issues coexist. Besides, temperature prediction and oil-based mud (OBM) removal also add to the complexity of the cementing operations. A novel cementing technology for deep water development wells has been developed in order to ensure long-term isolation. This paper will describe in detail how to design the cement slurry parameters, how to apply the hydrate decomposition simulation, how to predict the temperature and how to remove the OBM. With the novel technology, cementing operations in Block X have been successfully carried out for 11 wells, achieving the desired objective of well bore integrity. Cement bond logging (CBL) evaluation has shown excellent bonding result. This successful cement operation helped to establish record for the biggest deep water gas field in South China Sea.
Innovative Placement for Epoxy Sealant to Cure Casing Sustained Annulus Pressure – Implementation in Gulf Area.
Authors: Zhukin A. , Al Dahmani S. , Yugay A. , Tawfik F. G. , Alkarbi M. , Olsen J. E.
Published: August 2024

More than 30% of the wells worldwide are reported to have unplanned Sustained Casing Pressure (SCP) / Sustained Annulus Pressure (SAP) based on recent data1. The issue greatly impacts production methods of field development with subsequently large impact on well expenditure. Several techniques are available to repair SCP/SAP however, they are mostly limited by rate of circulation and injectivity during squeezing and placing cementitious material behind casing. The objective of this paper is to demonstrate and share experience gained in the Gulf region to apply innovative placement methods of an alternative material (epoxy) for well repair of SAP in cases of no injectivity to cure fluid migration behind casing.

The most common and widely used practice to cure SAP/SCP behind casing is conventional casing milling and / or perforation with subsequent cement lock-up squeeze with subsequent pumping cementitious material from surface to the annulus. Unfortunately, this practice has a low success rate. Circulation cementing squeeze is not practical in many cases since we conduct primary cement job with cement to the surface and in many cases conduct subsequent "top up" job. There is an advanced solution using PWC-Perforate, Wash and Cement with special tool, that delivers reliable results, however it requires to have interval with poor cement isolation. The proposed advanced Downhole Annular Repair method has been utilized in the Gulf region country to cure sustained annulus pressure behind production casing. The method allows a single wireline run to accomplish successful SAP curing with following major steps: Positioning/anchoring tool at desired depth; gain access behind casing via a set of radial perforations and placement of epoxy resin using internal pump in the hesitation injection over the extended period of time.

The 4 wells have been treated using the innovative placement and alternative material to cure SAP behind production casing. Sealant has been injected using hesitation mode for a period of 10-20 hrs until initial setting time is reached. Well commissioning results demonstrated successful SAP treatment on 4 wells.
Revolutionary Pre-Set Well Design: Removing an Entire Section, Speeding Up Well Delivery by Six Days
Authors: Agarwal Rohit , Essmat Nooruldeen Zeyad , Paz Daniel , Alismail Ahmed , Lopez Gustavo , Diaz Leonardo , Levario Jesus Alvidrez , Corona Mauricio
Published: August 2024

The conventional pre-set well design involves landing the well at high inclination (50 – 60 degree) on top of the reservoir using six (6) casing policy followed by drilling of multi-laterals across the reservoir using under-balance coiled tubing drilling (UBCTD). A novel well design is presented in this paper which eliminates one complete casing string without compromising the well's objectives. The 8-3/8-in. hole section is drilled across a highly charged formation and secured with a 7-in. liner. Consequently, a 5-7/8-in. section is then drilled and landed on top of reservoir. The well is later completed using 4-1/2-in. cemented liner, which is mandatory as per well requirement. In this paper, the critical design criteria are explored while combining these two (2) sections, considering well control requirements, and cementing methodologies to ensure proper separation of highly charged layers from the reservoir.

This optimization has resulted in a time saving of six (6) days which enabled the well under study to set a record as the fastest well delivered in this category. This concept has been adopted in consecutive wells and is emerging as a new standard for the specific type of well.

By combining the last two (2) sections in a single hole size, the time for running the 7-in. liner, 5-7/8-in. cleanout trip and drilling the short 5-7/8-in. hole is saved which results in a direct time savings for the operation. The paper details how the last section was drilled as an 8-3/8-in. hole and cased off with 7-in. × 4-1/2-in. liner tapered string using fit for purpose centralizers. Furthermore, to ensure the integrity of this solution, a clean-out bottom hole assembly (BHA) combined with inflow test assembly was run in hole and the shoe track was drilled till 20ft above shoe simultaneously. The integrity of cement job and liner top packer was validated by performing inflow test. The well is then completed with upper completions, production tree installed and well is temporary abandoned where the Coil Tubing Drilling (CTD) rig will come later in future to drill the remaining cement in shoe track and reservoir.

The optimized well design explores the design criteria for combining of two (2) sections and presents a novel solution to explore such possibilities in other well designs.
Unprecedented Design and Deployment of Advanced Lower Completions in an Extremely Challenging Environment in the Middle East
Authors: AlHosni F. , AlRomaihi A. , Arias M. , AbdulRahim S. , Uslu M. , Yasari A. , Rojas L. , Handoko L. , Centeno M.
Published: August 2024

Deploying advanced lower completion in long lateral big bore carbonates sections in one of the Middle East giant fields has presented a considerable challenge due to various factors such as well designs, extreme hole conditions, high friction factors, risk of getting stuck, severe loss circulation, to a premature setting of packers. This manuscript outlines the innovative initiatives and solutions that resulted in a pathbreaking deployment of a complex lower completions assembly in the subject field.

On offset wells, several complications were encountered in running big bore Limited Entry Liner (LEL) with inner string to the setting depth due to high friction factors, hanger capacity limitations, lost circulation, and packers’ restrictions, which increased the complexity and led to long non-productive times (NPT). During the drilling phase, initiatives were taken to optimize the connection practices, conditioning the wellbore, and devise an effective fluids displacement strategy. Pioneering solutions were developed and implemented with the LEL hanger system and liner centralization and deployed with engineered reservoir-friendly completion fluids having remarkably reduced friction factors.

To deploy the advanced lower completions safely without encountering issues, as seen in the offset wells, several new engineered solutions were introduced on the subject well through a multi-level risk assessment to identify all the risks and hazards involved during the execution and eliminate or mitigate them in the backdrop of a thorough analysis of the offset wells. The change in connection practices and wellbore conditioning while drilling ensured a smooth lateral section to run in the hole lower completions. Innovative modifications were made to the liner hanger system allowed the removal of a dedicated inner displacement string. Further, the friction factors were still high. With the risk of getting stuck and lost circulation, the low friction factor, displacement, and loss control strategies of the reservoir-friendly completions fluid with improved centralization of the lower completions assembly not only eliminated the sticking tendency but also eliminated the need for friction reduction tools, leading to a safe deployment of the advanced lower completions with swellable packers, successfully meeting the early production objectives in a record time compared to previous similar jobs performed.

This paper covers the existing gap in knowledge related to the deployment of advanced lower completions assembly in challenging downhole conditions and complex well design that led to making the pavement for all upcoming similar applications in the subject field. The solutions and lessons learned presented in this study have the potential for global replication, offering valuable guidance for similar projects worldwide.
Chronic gut inflammation differentially modulates mitochondrial and antioxidant transcriptional programs in limbic brain structures
Authors: MATISZ Chelsea E , LAPOINTE Valerie , BEEKMAN Kaylen , HAIGHT Travis , SUTHERLAND Robert J , ZOVOILIS Athanasios , GRUBER Aaron J
Published: August 2024

Chronic inflammatory diseases are frequently comorbid with depression and anxiety, often persisting during periods of inflammatory remission. This suggests functional changes to neural circuits involved in the contextual regulation of motivation and threat processing. Here, we test how chronic gut inflammation evoked by dextran sodium sulfate (DSS) affects gene expression in several limbic brain structures associated with these functions. We assessed post-mortem expression of mRNA transcripts in the anterior cingulate cortex (ACC), CA1 hippocampus, nucleus accumbens (NAc), and primary motor cortex (M1) as a non-limbic control. The levels of mRNA associated with mitochondrial function, inflammation, and synaptic connectivity were altered in DSS-treated animals, but the specific pattern of changes was heterogeneous among brain structures. Chronic gut inflammation affected transcript expression in the CA1 and NAc more so than in the ACC and M1. These differences involved genes related to antioxidant systems and mitochondrial function. For example, expression of the cytochrome oxidase 1 gene mt-co1, which is necessary for oxidative phosphorylation, was reduced in ACC and NAc of DSS animals, suggesting reduced capacity for ATP production in these regions. Markers of gut inflammation correlated with expression of several transcripts in the ACC, including markers of synapses and GABA synthesis. The NAc showed strong correlations of mitochondrial function and measures of mitochondrial fission, inflammation, synaptic connectivity, and GABA synthesis. In sum, these data indicate neuroinflammatory processes in the brain evoked by chronic relapsing gut inflammation are heterogeneous among brain structures, and possess complex relationships between mitochondrial function, antioxidants, neurotransmission and gut inflammation.
Event-based mapping and spatial pattern analysis of landslides in parts of central Vietnam
Authors: Das Raja , Wegmann Karl William , Tien Pham Van
Published: August 2024

Systematic inventorying after large triggering events is essential for understanding the spatio-temporal dynamics of landslides and enabling advanced predictive analysis. The landslide inventories triggered by typhoon Ketsana, tropical storm Podul, and typhoonMolave in the highlands of central Vietnam are presented to better understand the spatial interaction (i.e., clustering, dispersion, or independence) among these landslide events using a global clustering indicator Ripley’s K. A total of 8,744, 915, and 10,257 landslides were mapped and attributed to typhoons Ketsana, Podul, and Molave, respectively, utilizing high-resolution RapidEye (5m/px) and PlanetScope (3m/px) satellite imagery. The inhomogeneous Ripley’s K and cross K-functions were employed for intra-inventory and inter-inventory landslide distribution analyses to assess the clustering, dispersion, or randomness of landslide occurrences at various distances. The findings reveal pronounced clustering among landslides triggered by typhoons Ketsana and Molave. In contrast, tropical storm Podul caused landslide clustering up to 22.5 km, after which a strong aversion was observed. Interactions between landslides from the Ketsana and Molave inventories exhibited clustering within the 0–8.1 km range and repulsion beyond 8.6 km. Conversely, landslides from the Ketsana and Podul events displayed repulsion at all distances, indicating the absence of clustering. Subsequently, a Spatial Kolmogorov-Smirnov test was conducted on seven continuous covariates—elevation, topographic slope, topographic aspect, Topographic Position Index, drainage density, annual average rainfall, and distance from mapped geologic faults. A Chi-square test was applied to lithology as a categorical covariate. These analyses aimed to evaluate the spatial independence of landslide distribution concerning these covariates. A statistically significant p-value in these tests indicated a non-random spatial association between landslide occurrences and the covariates, signifying spatial dependency among them.
Multi-target quantum compilation algorithm
Authors: Binho Le , Hai Vu Tuan , Viet Nguyen Tan , Urbaneja Jesus , Linh Nguyen Vu , Lan Tran Nguyen
Published: August 2024

In quantum computing, quantum compilation transforms a target unitary into a trainable unitary represented by a quantum circuit. Traditional quantum compilation optimizes circuits for a single target. However, many quantum systems require simultaneous optimization of multiple targets. To address this, we developed a multi-target quantum compilation algorithm to enhance the performance and flexibility of simulating multiple quantum systems. Our benchmarks and case studies demonstrate the algorithm’s effectiveness, highlighting the significance of multi-target optimization in advancing quantum computing. This work establishes the foundation for further development and evaluation of multi-target quantum compilation algorithms.
Optimization of fly ash and cement for stabilizing clay soil
Authors: H Nur Md. Robiul , Islam Shriful , Ray Sourav , Sarker Shuva , Islam Junaidul
Published: August 2024

Fly ash and cement are commonly used as soil stabilizers, offering environment friendly solutions for soil improvement. This study aims to determine the ideal combination of fly ash and cement to improve the geotechnical behavior of clay soil collected from a future building construction project in Sylhet, Bangladesh. Strength development in soil was assessed across a wide range of fly ash (0–25%) and cement (0–18%) during 3-, 7-, 14-, and 28-day curing periods. Tests included in this research are: Atterberg limits test, standard Proctor tests, unconfined compressive strength (UCS) and scanning electron microscopy tests. Incorporating fly ash, cement, or both decreased maximum dry density (MDD) and increased optimum moisture content (OMC) of the soil, while soil classification remained consistent. The investigation revealed that fly ash initially had a higher reduction rate in MDD of the mixtures up to around 7% binder content, before cement took precedence. Optimal soil-binder strength was achieved at 5% fly ash and 8% cement after curing for 28 days individually. However, the optimal combination of the binders was identified as 6% (3% fly ash and 3% cement), yielding a 99.51% increase in UCS compared to untreated soil after 28 days. Scanning electron microscopy tests show that the compactness of clay soil increases due to the addition of fly ash and cement. This binder combination (3% fly ash and 3% cement) could be suitable for stabilizing clay soil beneath the shallow foundation of a residential building in the study area.
Data-driven non-intrusive reduced order modelling of selective laser melting additive manufacturing process using proper orthogonal decomposition and convolutional autoencoder
Authors: Chaudhry Shubham , Abdedou Azzedine , Soulaimani Azzeddine
Published: August 2024

Two data-driven, non-intrusive, reduced-order models (ROMs): a convolutional autoencoder-multilayer perceptron (CAE-MLP) and a combined proper orthogonal decomposition-artificial neural network (POD-ANN) are proposed and compared for additive manufacturing (AM) processes. The CAE-MLP uses a 1D convolutional autoencoder for spatial dimension reduction of a high-fidelity snapshot matrix constructed from high-fidelity numerical simulations. The reduced latent space after compression is projected to the input variables using a multilayer perceptron (MLP) regression model. The POD-ANN uses proper orthogonal decomposition-based, reduced-order modeling with the artificial neural network to construct a surrogate model between the snapshot matrix and the input parameters. The accuracy and efficiency of both models are compared based on the thermo-mechanical analysis of an AM-built part. A comparison between the statistical moments from the high-fidelity simulations results and the ROMs predictions reveals a good correlation. Additionally, the predictions are compared with the experimental results at different locations. While both models show good comparison with the experimental results, the CAE-MLP predictions have proven to be better performing than those of the POD-ANN.
Analyzing the Experiences of Buruli Ulcer Disease Patients in Nigeria Using the Socioecological Model of Health: A Qualitative Cross-Sectional Study
Authors: Azubuike Precious Chidozie , Onyekachi Ebuka Light , Enyam Michael Obule , Ogbonna Chimankpam Kingsley , Timothy Promise Nmesomachi , Uchegbu Eberechukwu Ruth , Abuo James , Akinreni Temidayo
Published: August 2024

Introduction Buruli Ulcer Disease (BUD) is a debilitating neglected tropical disease caused by “Mycobacterium ulcerans”, predominantly affecting marginalized populations in tropical and subtropical regions, including Nigeria. This study utilizes the socioecological model of health to explore the complex interplay of individual, interpersonal, community, and societal factors shaping the experiences of BUD patients in Nigeria. Previous research has primarily focused on biomedical aspects, often neglecting the sociocultural and environmental dimensions crucial to patient experiences and outcomes.Methods A qualitative cross-sectional descriptive research design was employed, focusing on selected BUD endemic communities in Enugu State, Nigeria. Ethical approval was obtained from the Enugu State University Teaching Hospital’s Research and Ethics Committee. Data collection involved one Focus Group Discussion (FGD) with eight discussants and six Key Informant Interviews (KII), encompassing a diverse group of BUD patients. The WHO Quality of Life-BREF was adapted for data collection, which was conducted by a trained team. Data were analyzed using content analysis to inductively code themes and identify overarching categories.Results At the individual level, participants reported significant physical and psychological impacts, including pain, discomfort, disfigurement, and stigmatization. Interpersonal experiences highlighted social rejection, loss of social roles, and abandonment by family members. Organizational challenges included job loss, reduced productivity, and financial dependence, while community-level experiences ranged from supportive actions to social isolation and discrimination. Participants noted a lack of comprehensive community support, often exacerbated by misconceptions about the disease.Conclusion BUD patients in Nigeria endure considerable negative psychosocial experiences, particularly at the interpersonal and community levels. Enhancing community awareness and support is crucial to mitigating these impacts. Further research should explore family-level psychosocial experiences and other contributing factors to provide a more comprehensive understanding and inform effective intervention strategies.
Seroprevalence of West Nile, Usutu and Tick borne encephalitis viruses in equids from southwestern France in 2023
Authors: Chevalier Noémie , Migné Camille Victoire , Mariteragi-Helle Teheipuaura , Dumarest Marine , De Mas Margaux , Chevrier Manon , Queré Emilie , Marcillaud-Pitel Christel , Lupo Coralie , Bigeard Clément , Touzet Thierry , Leblond Agnès , Durand Benoit , Depecker Marianne , Gonzalez Gaëlle
Published: August 2024

The circulation of West Nile virus (WNV), Usutu virus (USUV) and Tick-borne encephalitis virus (TBEV) was investigated in southwestern France within the first six months of 2023 following the emergence of WNV in equids in Gironde county in 2022. Blood samples were collected from 494 horses located in Gironde County divided into three zones: the Confluence, the Intermediate zone and the Arcachon basin and tested for WNV, USUV and TBEV specific antibodies. An overall seroprevalence of 14% (95% CI [11%-18%]) for orthoflavivirus antibody was detected in Gironde county. The highest seroprevalence rate for WNV and USUV were detected in the Confluence zone (9%, 95% CI, [6%-13%] and 5%, 95% CI, [3%-8%] respectively). The type of housing (animals kept in pasture only) and the distance to the nearest bird special protection area (SPA) were identified as risk factors for WNV seropositivity. This paper presents the first seroprevalence study investigating WNV, USUV and TBEV infections, conducted in equids located on the Atlantic coast of France and demonstrates an intense circulation of WNV in this region of France as well as equine USUV specific infection.
Hierarchical carbon nanofiber/NiCo2O4 composites as electrode for high-performance supercapacitors
Authors: Zhuo Qiqi , Lv Yalou , Wu Hanzhao , Jiang Jintian , Tang Jijun , Yan Chao
Published: August 2024

Carbon Nanofibers (CNFs)/transition metal oxides (TMOs) composites have obtained much attention as supercapacitor electrode with benefits from the superior electrical conductivity of carbon materials and high capacity of TMOs. However, nano-size TMOs is prone to agglomeration and hard to grow efficiently and uniformly on CNFs due to the surface of CNFs lack effective targets, which limits its performance. In this paper, different hierarchical structures of CNFs-NiCo2O4 were prepared and assembled as supercapacitor electrode. The results showed that CNFs-NiCo2O4 prepared by treatment of potassium permanganate exhibited a high capacitance of 1175 F g− 1 at a current density of 1 A g− 1 and long-term cycling stability, with 93% capacitance retention after 3000 cycles. The excellent electrochemical performance could be attributed to that more active sites were introduced on the CNFs after solvent treatment, which were beneficial for NiCo2O4 to grow uniformly on CNFs. This approach provides a new strategy for controllable design and synthesis of homogeneous hierarchical CNFs/TMOs composites.
Bottleneck factors impacting nurses’ workflow and the opportunity to prioritize improvement efforts: Factor analysis
Authors: Al-Moteri Modi , Aljuaid Jamil , Alsufyani Bander , Alghamdi Amnah , Althobiti Ensherah Saeed , Althagafi Abdulslam
Published: August 2024

Purpose
Minimizing delays in delivering nursing care is paramount for enhancing the overall quality of care. Certain bottleneck variables restrict the workflow of nurses, resulting in extended shift times. This study is designed to pinpoint and analyze the principal factors contributing to bottleneck issues in nursing workflow, to direct improvement endeavors. This study seeks to provide insights into the key variables contributing to nurses' extended shift times, with the ultimate goal of prioritizing efforts for improvement.
Methods
A descriptive multicenter cross-sectional study was conducted. A scale was developed for this study by the authors after conducting a literature review, subsequently validated, and its reliability was assessed.
Results
Among the 31 bottleneck variables, 29 were retained under three bottleneck factors: (1) Nurse staffing— This pertains to the availability of sufficient nursing staff at all times across the continuum of care; (2) Working environment and quality of care—This refers to the availability of necessary skills and resources for nurses to perform their duties effectively and; (3) Medical devices— This factor concerns the availability of fully functional medical devices required for providing care.
Conclusion
Efforts aimed at enhancing the overall healthcare system should concentrate on addressing bottleneck factors. This may involve the implementation of a healthcare workforce management system, the establishment of standards for a conducive and supportive working environment, and the utilization of a standardized system for the management of medical equipment. The outcomes of this study can be utilized by nurses and policymakers to devise comprehensive strategies for improvement.
Let us Unveil Network Intrusion Features: Enhancing Network Intrusion Detection Systems via XAI-based Feature Selection
Authors: Arreche Osvaldo , Guntur Tanish , Abdallah Mustafa
Published: August 2024

Explainability and evaluation of AI models are crucial parts of the security of modern intrusion detection systems (IDS) in the network security field, yet they are lacking. Accordingly, feature selection is essential for such parts in IDS because it identifies the most paramount features, enhancing attack detection and its description. In this work, we tackle feature selection problem for IDS via suggesting new ways of applying eXplainable AI (XAI) methods for this problem. We identify the crucial attributes originated by distinct AI methods in tandem with novel five attribute selection methods. We then compare many state-of-the-art feature selection strategies with our XAI-based feature selection methods, showing that most AI models perform better when using the XAI-based approach proposed in this work. By providing novel feature selection techniques and establishing the foundation for several XAIbased strategies, this research aids security analysts in the AI decision-making reasoning of IDS by providing them with a better grasp of critical intrusion traits. Furthermore, we make the source codes available, thus the community may develop additional models on top of our foundational XAI-based feature selection framework.
Effects of wind speed, spacing distance and length-width ratio of burner on flame merging and heat transfer of two-line fires
Authors: Huang Xinjie , Hu Junjie , Ding Hailong
Published: August 2024

This paper investigates the effects of wind speed(V=0.25, 0.5 and 0.75 m/s), length-width ratio(n=5,8,10,15,20,25,30 and 40) and spacing distance(0, 10, 20 and 30 cm) on the burning and flame merging characteristics of two-line fires fueled by n-heptane. Experimental results indicate that the flame merging probability Pm decreases gradually with the increasing length-width ratio. Meanwhile, Pm shows an increasing trend with the groove length(L).The correlation between P m with n and L is found. On the other hand, it is found that,flame height and length decrease with the increasing length-width ratio.The flame height and length of upstream flame are smaller than those of downstream flame for different length-width ratios, at the same n and V. With the length-width ratio increase, the flame inclination angle will increase, and that of upstream flame is consistently smaller than that of downstream flame. Based on heat transfer analysis, under the influence of wind speed, the m '' is closely related to (L+W)/LW, showing an increasing trend with length-width ratio.With the increase of spacing distance, the ṁ '' of downstream flame will be larger, equal and then smaller than that of upstream flame.
Fusing Deep Separable Networks for Emotion Recognition in Complex Environments
Authors: Wan Zheng-Hao , Wu Chun-Lei , Tong Si-Yuan , Qiu Shi-Yu
Published: August 2024

This research is dedicated to addressing the challenges of model training and application implementation in the field of traditional face emotion recognition. The proposed scheme is a lightweight facial emotion recognition system based on deep separable networks. The scheme optimizes the Xception network structure in three stages. Initially, the residual module and the deep separable module are combined in order to enhance the efficiency of feature extraction. Subsequently, global average pooling is employed in lieu of the traditional fully connected layer, thereby reducing the number of parameters. Finally, the channel information is integrated through the 2×2 convolution and the point-by-point convolution, which effectively minimizes the loss of information while retaining more valuable feature information. The solution employs the Fer2013 dataset from the Kaggle platform for training with the objective of enhancing the accuracy of emotion recognition in diverse and complex environments within a simulated real-world setting. Furthermore, the objective is to develop a lightweight model that can be deployed in practical applications. The recognition accuracy has now reached an industry-leading level. Moreover, the project has developed a face emotion recognition system that has been validated through the construction of a real-time vision system. This system is capable of completing the tasks of face detection and emotion classification in complex environments, thus providing a solid foundation for the practical application of emotion recognition technology. The source code for the proposed method will be available at https://github.com/Alex-star-arch/Fusing-Deep-Separable-Networks-for-Emotion-Recognition-in-Complex-Environments.
Prediction of Yearly Mean Sunspot Number using Machine Learning Methods
Authors: Paraskakis Nikolaos , Hristopulos Dionissios T.
Published: August 2024

The number of sunspots is an important indicator of solar activity, which has an impact on space weather and the Earth’s climate. Hence, sunspot number prediction is an integral part of solar cycle monitoring for the National Aeronautics and Space Administration, the European Space Agency and other space and environmental agencies. The advent of novel machine learning tools creates new opportunities for modeling and prediction of time series datasets. This paper compares predictions of the yearly sunspot number with three different machine learning methods in terms of prediction performance, computational speed, and interpretability. The methods explored involve a stochastic approach (Gaussian process regression), a method based on decision trees (Light gradient boosting machine), and a long-short-term memory neural network. The relative strengths and weaknesses of each method are discussed.
Immunomodulatory effects of albendazole, trichlorobendazole and wortmannilactone F on Clonorchis sinensis infection
Authors: Duan Guihua , Zhang Baoyue , Gong Xiarong , Xun Linting , Zhao Xueru , Li Yongli , Song Zhengji
Published: August 2024

Background
Albendazole, trichlorobendazole and wortmannilactone F are widely used anti-trematode drugs to treat fluke worm infections. However, their immunomodulatory effects and hepatic toxicity in Clonorchis sinensis infection treatment are unknown. This study evaluated the regulatory effects of these anti-helminthic drugs on hepatic fibrosis and immune responses in the rat model of Clonorchis sinensis infection.
Methods
Sprague-Dawley rats were infected by Clonorchis sinensis thorough gavage. Hematoxylin and Eosin (H&E) and Masson staining were performed to examine the degree of hepatic injury and fibrosis. Plasma levels of glutamic-pyruvic transaminase and albumin were analyzed by ELISA. Flow cytometry was used to detect the frequency of immune cells in the blood sample upon different drug treatments.
Results
Fecal examination showed that the administration of trichlorobendazole and wortmannilactone F could effectively eliminate the parasites, and albendazole was also able to reduce the parasite load. Albendazole had little damage to the liver tissues, while wortmannilactone and triclorobendazole could induce severe hepatic damages. Masson staining further revealed high level of hepatic fibrosis after wortmannilactone F and triclorobendazole treatment, which was accompanied by the increased CK-19 keratin expression after wortmannilactone F treatment. Albendazole administration was able to reduce the plasma level of IL-2 and decrease the proportion of CD4 + and CD8 + T lymphocytes in the blood, while the other two drugs failed to do so.
Conclusion
Wortmannilactone F and triclorobendazole showed strong anti-parasitic effect against Clonorchis sinensis infection, but induced severe liver damages. Albendazole could reduce parasite load and also showed immunomodulatory effect.