bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lessons Learned Using a Next Generation Active Sealing Device for Deepwater MPD Operations
Authors: Johnson Austin , Sundaramoorthy Saravanan , Ameen Kareem , Nichols Jess , MacGregor Alex , Fraczek Justin 
Published: March 2021

Abstract
This paper shares results from the first year of deepwater operations using an active sealing device purpose built for deepwater Managed Pressure Drilling (MPD). The active sealing device is a clean-sheet design approach. The first use of the system was performed in a narrow margin deepwater well in the Black Sea with subsequent wells in the Gulf of Mexico. This paper shares lessons learned from first year of operations.
This paper discusses field operations, lessons learned, and post run evaluation of system performance. An overview of the design introduces system elements and briefly discusses system testing measures taken prior to field deployment. An overview of operations from the first year is provided, highlighting lessons learned, action items taken, and solutions implemented between wells. Analysis of the link between the testing and field results demonstrates the novel approach to testing and validity of assumptions made during the testing phase. Furthermore, methods of evaluating seal performance are discussed.
The paper shares conclusions from the first year of active sealing device deployment. A non-rotating seal sleeve element design eliminates multiple high-wear rotating control device (RCD) components such as bearings and rotary seal as well as their associated failure modes.Redundant, active seal elements ensure wellbore seal quality throughout the seal assembly life.Active seal condition monitoring alerts the rig crew prior to failure to replace the seal assembly.Multi-modal seal control provides crew methods to reach total depth in contingency mode.Full-scale simulated drilling testing included the use of client equipment prior to first use.Testing procedures were designed to simulate drilling to mirror system use in a live well.First MPD well completed in 2019 in the Black Sea with subsequent wells in the Gulf of Mexico.Lessons learned from operations to applied in continuous improvement program.Novel approaches to assessing performance have been developed in order to provide consistent metrics.Learnings have been applied in subsequent wells to improve technology transfer to drilling contractors.
The paper discusses other aspects of the program such as drilling contractor ownership vs. use of third (3rd) party systems, integration of the MPD equipment into the rig, and network architecture. Further, an algorithm has been developed to analyze system performance from electronic drilling recorder data to better characterize the effect of usage patterns of seal wear. These data demonstrate the validity of assumptions made during the development of the test procedures.
Simple but Effective: A Case History Demonstrating Enhanced Performance and Simplified Logistics from New Rotary Steerable
Authors: Aburto Perez Marco A , Yadav Anurag S , Farley Steven R 
Published: March 2021

Abstract
Based on input from key operators in the Middle East region, a new rotary steerable system (RSS) was launched after a compressed development schedule. This paper describes the development and introduction of the larger tool sizes needed for both onshore and offshore hole sections, including hole sizes from 12 in. and up, in the Middle East. It also outlines the deliberate design of the tool for local assembly and repair.
Large diameter (9-1/2 and 11 in.) RSS designs used an existing, smaller design for Middle East applications in both offshore and onshore wells as a basis. When designing these new sizes, engineers took note of lessons learned with smaller sizes of the tool and incorporated design elements for local manufacturing, assembly, and repair. The resulting simple, modular construction enables increased levels of local content and provides for significant reductions in transportation, and therefore associated emissions.
Of course, although local content and sustainability are highly desirable, performance is essential, and this paper describes case histories demonstrating how well the new tool worked in real-world Middle East applications.
In one notable example, the newly introduced 9 1/2-in. diameter RSS was used to drill an offshore section in the Gulf of Arabia. The tool was mobilized after two older generation RSS had become stuck for days. Consisting primarily of argillaceous limestone, the formation had a history of stuck-pipe events. The new RSS was recommended for this application because of a slicker construction, with a fully rotational bias unit, minimal bottom hole assembly (BHA) stabilization, and an optimized junk slot area, which together help to reduce stuck-pipe risks. The tool drilled to the target depth in a single run, thereby achieving all directional requirements. Notably, after reaching the target depth, the assembly was tripped out of the hole without any requirement for backreaming. This seamless exit, in turn, indicated achieving a smooth wellbore.
Other case histories demonstrate results with both new sizes of this tool. The paper also discusses in detail the ability to repair locally and engage the local supply chain.
Specifically with Middle East applications in mind, a new, simple RSS design in large diameter versions has demonstrated success in offshore and onshore applications across the region. The design has also proven capabilities for manufacturing and repair local to operations, which enables maximizing in-country value, optimizing use of the tools, and energizing local supply chains.
Borehole Disposal of Nuclear Waste
Authors: Kristiansen Håvard , Aadnøy Bernt Sigve 
Published: March 2021

Abstract
Approximately 370 000 tons of high-level radioactive waste exists. Some nations have mature projects for disposing of such waste in mined repositories hundreds of meters below ground. Emplacement in boreholes of greater depth could be a cost-efficient and fast alternative, particularly for nations with relatively small amounts of waste. A borehole repository could be developed via an iterative process, which would ultimately end with the completion of a comprehensive safety case and a fully operational disposal facility which would be sealed and decommissioned in a reliable manner. Each design should be adapted to the properties of the waste in question, site-specific geological conditions, and regulatory requirements. This variability causes designs and cost estimates to differ. Overall, borehole disposal of high-level radioactive waste is an opportunity for the drilling industry to expand its service portfolio in a way that is beneficial to the environment and the safety of current and future generations.
When Slick is Not Smooth: Bottom-Hole Assembly Selection and Its Impact on Wellbore Quality
Authors: Willerth Marc , Dodson Briana , McCue Kelton , Farrag Mahmoud 
Published: March 2021

Abstract
Appropriate selection of a bottom-hole assembly (BHA) is critical to the success of a drilling operation. In US Land drilling, these assemblies are often selected using local heuristics rather than rigorous analysis. These heuristics are frequently derived from the incentives of the directional contractor as opposed to incentives for the operator. Large motor bends enable more rotation though the curve and reduce the possibility of tripping for build rates. Unstabilized motors are believed to aid sliding and tool face control. Both of these practices lead to drilling a more tortuous wellbore and may cause problems later in the well’s life. This study quantifies the impact of these practices and proposes alternatives that can balance the needs of directional companies with the desire of operators for high-quality wellbores.
Over 60 conventional motor assemblies used to drill curves in the Eagle Ford and Permian were analyzed for directional performance using commercial drillstring analysis software. The sliding and rotary tendencies were modelled through the curve across a range of potential drilling conditions. Expected build-rate models were validated by comparison to the maximum achieved doglegs in the directional surveys. When available, additional validation was performed using motor yields calculated from slide sheets. The validated models were compared to the dogleg severity requirements for each assembly’s respective well plan. Comparisons of slide ratios and slide/rotate tendencies of the BHAs were used to estimate the impact on wellbore quality using the tortuosity metric proposed by Jamieson (2019).
Typical well plans for both basins had curves of 10 degrees/100ft with no well plan greater than 12 degrees/100ft. Typical bottom hole assemblies were capable of &gt;15 degrees/100ft under normal sliding conditions, with some assemblies capable of &gt;20 degrees/100ft of build. Predicted build rates were validated by slide sheets and observed dogleg severities. Common characteristics among assemblies with excess capacity were high bend angles (&gt;=2 degrees) and minimal stabilization. These slick assemblies also had a strong drop tendency in rotation at low inclinations. The combination of high-build rate with rotary drop greatly increases tortuosity, particularly in the early stages of well. A minority of the assemblies used a lower motor bend angle (&lt;2 degrees) combined with multiple stabilizers. These assemblies had a more consistent directional capability throughout the curve and held angle in rotation. The success of these assemblies confirms that a higher quality wellbore with an improved BHA design is technically achievable.
As increasing attention is afforded to the topic of wellbore quality it is important to have methods available to technically achieve high-quality wellbores. In addition to the management of drilling practices, it is also important to have an appropriate BHA design that can enable those practices
Energy Efficiency and Emissions of a Natural-Draft Wood Pellets Gasifier Compared to Charcoal Cookstoves in Kenya
Authors: Gituku Benjamin Mwondwe , Khisa Kevin , Bogonko Nathan , Mesa Cicilia 
Published: March 2021

Abstract
The conversion of biomass to make charcoal fuel is an inefficient process that leads to immense energy losses along the value chain. We compared the energy efficiency and emissions of Gastov206, a natural draft TLUD gasifier cookstove using two sizes of wood pellets, as an alternative to two contemporary charcoal stoves in Kenya. A laboratory test showed that more energy in the fuel was lost by the charcoal cookstoves (69%) compared to the pellet gasifier cookstove (31%). The pellet gasifier cookstove had high thermal efficiency and cooking power (65–73%, 0.95–1.13 kW) compared to the charcoal cookstoves (27–35%, 0.68–0.89 kW). During the test, Gastov206 converted pellets-to-char at a ratio of 25% and a rate of 3 g/min. These findings indicate that when biomass is converted to pellets rather than charcoal, and cooking continues over the burning char generated by the gasifier cookstove, energy currently being wasted converting wood-to-charcoal can be avoided. Gastov206 using pellets showed lower CO emission (4.46–5.47 g/MJd and 0.27–0.39 g/min) compared to charcoal cookstoves (20.82–24.36 g/MJd and 0.89–1.35 g/min). PM2.5 emission by Gastov206 (52.35–61.50 mg/MJd and 3.21–4.37 mg/min) was not significant different compared to charcoal stoves (40.81–41.13 mg/MJd and 1.69–2.35 mg/min). Laboratory results show that natural-draft gasifier cookstoves using pellets can be studied further in kitchens as an alternative to charcoal cookstoves since they are potentially more energy-efficient.
Knowledge, Attitude and Practice Among Caregivers Towards Pressure Ulcer in Spinal Cord Injury at Rehabilitation Center in Bangladesh
Authors: Tharu Niraj , Alam Monzurul , Bajracharya Shristi , Kabir Mohammad 
Published: March 2021

Abstract
Study design:
A quantitative cross-sectional survey study.
Objective

To determine the knowledge, attitude and practice (KAP) among caregivers regarding prevention and care of pressure ulcer in patients with spinal cord injury and relationship between KAP.
Setting:

Centre for Rehabilitation of Paralysed, Dhaka, Bangladesh.
Methods

A descriptive correlational design with modified semi-structured questionnaire implemented through convenient sampling procedure. McDonald’s standard of learning outcome measured criteria was used to categorize caregivers’ level of knowledge and practice while, the total scores of attitude were categorized into three levels based on mean percentage and standard deviation: negative attitude below (mean ± 1 SD), neutral level (mean ± 1 SD), and positive attitude above (mean ± 1 SD). The pearson product-moment correlation coefficient (r) was used to examine the relationships between caregivers’ KAP and p- value of 0.05 or less was considered as statistically significant.
Results

Our results suggest that caregivers had a moderate level of knowledge (M = 73.68%, SD = 6.43), neutral level of attitude (M = 70.32%, SD = 6.89), and moderate level of practice (M = 74.77%, SD = 9.08). There was a positive correlation between caregivers’ knowledge and attitude (r = 0.30, p < 0.01), and between knowledge and practice (r = 0.37, p < 0.01). However, no correlation existed between attitude and practice (r = 0.12, p > 0.05).
Conclusion

The study findings suggests that caregivers need to develop a positive attitude and increase their knowledge in order to improve their practice.
The causes and frequency of kidney allograft failure in a low-resource setting: Data from Iraqi Kurdistan
Authors: Ali Alaa Abbas , Almukhtar Safaa E , Abd Kais H , Saleem Zana Sidiq M , Sharif Dana A , Hughson Michael D 
Published: March 2021

Abstract
Background
In the developing world, transplantation is the most common long-term treatment for patients with end-stage renal disease, but rates and causes of graft failure are uncertain.
Methods
In 2019, in Iraqi Kurdistan, 301 of 871 renal transplant patients had indicated graft biopsies. Outcomes were followed over the subsequent year of 2020.
Results
The post-transplantation time ranged from one day to 18 years. All donors were living. Approximately 15% of transplants were preemptive. Pretransplant hemodialysis (HD) was twice weekly and less than one year. The median recipient age was 39 (IQR 28 to 48) years. 5.5% of recipients had previous transplants; 3.7% had pretransplant donor-specific antibodies (DSA). The Kaplan-Meier estimated graft failure rates for all-cause, return to HD, and death with functional graft (DWFG) were 9.1%, 6.3%, and 2.9% at one year and 23.8%, 6.3%, and 7.4% at five years. The median death-censored graft survival was 15 years. The most frequent biopsy diagnoses associated with graft failure were interstitial fibrosis and tubular atrophy (IF/TA) (23.1%), transplant glomerulopathy (13.7%), and acquired active antibody-mediated rejection (11.1%). The significant predictors of graft loss were C4d + biopsies (P < 0.01) and advanced IF/TA (P < 0.001).
Conclusions
These Iraqi patients had estimated graft failure rates similar to the United States (US) Renal Data System living-donor outcomes reported for the year 2000. The inability to approach recent US graft survivals may owe to inadequate pretransplant dialysis. Nevertheless, prolonged survival made chronic disorders and acquired DSA the leading causes of graft failure and is creating a need for second transplants.
Acceptability of mentor mother peer support for women living with HIV in North-Central Nigeria: A qualitative study
Authors: Odiachi Angela , Al-Mujtaba Maryam , Torbunde Nguavese , Erekaha Salome , Afe Abayomi J. , Adejuyigbe Ebun , Galadanci Hadiza S. , Jasper Tongdiyen L. , Cornelius Llewellyn J. , Sam-Agudu Nadia A. 
Published: March 2021

Abstract
Background: Mentor mothers provide psychosocial and other support to pregnant and post-partum women living with HIV (WLHIV), which has been shown to enhance maternal-infant outcomes in the prevention of mother-to-child transmission of HIV (PMTCT). Our objective was to assess the acceptability of mentor mothers as a PMTCT intervention, and to explore opinions on mentor mother program composition and delivery among stakeholders in North-Central Nigeria.Methods: We conducted nine focus group discussions and 31 in-depth interviews with 118 participants, including WLHIV, pregnant women, male partners, health workers, traditional birth attendants, community leaders, PMTCT program implementers, and policymakers. Participants were purposively recruited from health facilities and surrounding communities in the Federal Capital Territory and Nasarawa State. Transcripts were manually analysed using a Grounded Theory approach, where theory was derived from the data collected.Results: Most participants were female (n=78, 67%), and married (n=110, 94%). All participant groups found MMs acceptable, as women providing care to pregnant and postpartum women, and as WLHIV supporting other WLHIV. Mentor mothers were uniquely relatable as role models for WLHIV because they were women, living with HIV, and had achieved an HIV-negative status for their HIV-exposed infants. Mentor mothers were recognized as playing major roles in maternal health education, HIV treatment initiation, adherence, and retention, HIV prevention for male partners and infants, and couple HIV disclosure. Most WLHIV preferred to receive mentor mothers’ services at health facilities rather than at home, due to concerns about HIV-related stigma and discrimination through association with mentor mothers. Key mentor mother needs were identified as training, remuneration, and validation as lay health workers.Conclusions: Mentor mothers are an acceptable PMTCT intervention among stakeholders in North-Central Nigeria. However, stigma and discrimination for both mentor mothers and their clients remain a critical challenge, and mentor mother needs such as training, pay, and a sustainably supported niche in health systems require focused attention. Trial registration: Clinicaltrials.gov registration number NCT 01936753, registered on September 3, 2013 (retrospectively registered).
Genomic markers for the biological responses of Triclosan stressed hatchlings of Labeo rohita
Authors: Sharma Sunil , Dar Owias Iqbal , Singh Kirpal , Thakur Sharad , Kesavan Anup Kumar , Kaur Arvinder 
Published: March 2021

Abstract
Triclosan (TCS) used commonly in pharmaceuticals and personal care products has become the most common pollutant in water. Three days old hatchlings of an indegenous fish, Labeo rohita were given 96h exposure to an environmentally relevant (0.06mg/L) and two moderately lethal concentrations (0.067 and 0.097 mg/L) of TCS and kept for 10 days of recovery for recording transcriptomic alterations in antioxidant/detoxification (SOD, GST, CAT, GPx, GR, CYP1a and CYP3a), metabolic (LDH, ALT and AST) and neurological (AchE) genes and DNA damage. The data were subjected to Principal Component Analysis (PCA) for obtaining biomarkers for the toxicity of TCS. Hatchlings were highly sensitive to TCS (96h LC 50 = 0.126mg/L and risk quotient = 40.95), 96h exposure caused significant induction of CYP3a, AChE and ALT but suppression of all other genes. However, expression of all the genes increased significantly (except for a significant decline in ALT) after recovery. Concentration dependent increase was also observed in DNA damage [Tail Length (TL), Tail Moment (TM), Olive Tail Moment (OTM) and Percent Tail DNA (TDNA)] after 96h. The damage declined significantly over 96h values at 0.06 and 0.067 mg/L after recovery, but was still several times more than control. TCS elicited genomic alterations resulted in 5-11% mortality of exposed hatchlings during the recovery period. It is evident that hatchlings of L. rohita are a potential model and PCA shows that OTM, TL, TM, TDNA, SOD and GR (association with PC1 during exposure and recovery) are the biomarkers for the toxicity of TCS.
External Assessment of the EUROMACS Right-Sided Heart Failure Risk Score
Authors: Shah Hirak , Murray Thomas , Schultz Jessica , John Ranjit , Martin Cindy , Thenappan Thenappan , Cogswell Rebecca 
Published: March 2021

Abstract
The EUROMACS Right-Sided Heart Failure Risk Score was developed to predict right ventricular failure (RVF) after left ventricular assist device (LVAD) placement. The predictive ability of the EUROMACS score has not been tested in other cohorts. We performed a single center analysis of a continuous-flow (CF) LVAD cohort (n = 254) where we calculated EUROMACS risk scores and assessed for right ventricular heart failure after LVAD implantation. Thirty-nine percent of patients (100/254) had post-operative RVF, of which 9% (23/254) required prolonged inotropic support and 5% (12/254) required RVAD placement. For patients who developed RVF after LVAD implantation, there was a 45% increase in the hazards of death on LVAD support (HR 1.45, 95 % CI 0.98–2.2, p = 0.066). Two variables in the EUROMACS score (Hemoglobin and Right Atrial Pressure to Pulmonary Capillary Wedge Pressure ratio) were not predictive of RVF in our cohort. Overall, the EUROMACS score had poor external discrimination in our cohort with area under the curve of 58% (95 % CI 52–66%). Further work is necessary to enhance our ability to predict RVF after LVAD implantation.
Effect of Biochar on Transformation of Dissolved Organic Matter and&nbsp;DTPA-Extractable Cu and Cd During Sediment Composting
Authors: Zhao Meihua , Cai Caiyuan , Yu Zhen , Rong Hongwei , Zhang Chaosheng , Zhou Shungui 
Published: March 2021

Abstract
This study investigated the influence of biochar on temperature, pH, organic matter (OM), seed germination (GI), the fluorescent components of dissolved organic matter (DOM), and bioavailability of DTPA-extractable Cu and Cd during composting and analyzed the relation between DTPA-extractable metals with pH, OM, and the fluorescent components of DOM. Results showed that the addition of biochar shortened the thermophilic phase, reduced the pH at maturation period, accelerated the decomposition of OM, and raised GI. Besides, it promoted the formation of components with benzene ring in FA and HyI and the degradation of protein-like organic-matters in FA and HA, which was mainly related with the decrease of DTPA-extractable Cd and the increase of DTPA-extractable Cu. After composting, DTPA-extractable Cd in pile A and pile B were decreased by 37.15% and 27.54%, respectively, while the bioavailability of Cu in pile A and pile B were increased by 65.71% and 68.70%, respectively. All these findings demonstrate positive and negative impact produced by biochar into various heavy metals and the necessary of optimization measures with biochar in sediment composting.