bluuebunny/crossref_metadata_2025_split huggingface dataset:
Report Outlines Knowledge Gained in Gas Hydrate Production Testing
Authors: Carpenter Chris 
Published: November 2020

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 29516, “Gas Hydrate Production Testing: Knowledge Gained,” by Timothy Scott Collett, SPE, US Geological Survey, prepared for the 2019 Offshore Technology Conference, Houston, 6-9 May. The paper has not been peer reviewed. Copyright 2019 Offshore Technology Conference. Reproduced by permission.
Gas hydrates are an important potential source of unconventional natural gas. Significant progress has been made with regard to understanding geologic and engineering limitations of the ultimate energy potential of gas hydrate; however, more work is required. The complete paper reviews the results of gas hydrate engineering and production testing studies associated with northern Canada and Alaska. The results of the marine gas hydrate producing testing efforts in Japan’s Nankai Trough and in the South China Sea are also summarized.
Mallik (Canada)
The Mallik gas hydrate research site in northern Canada has been the focus of three important gas hydrate field tests (in 1998, 2002, and 2007-08). The Mallik 2L-38 gas hydrate research well (part of the 1998 testing project) was drilled to evaluate the geologic controls on the occurrence of gas hydrate and to acquire specialized core and well data needed to characterize reservoir properties.
During the 2002 project, gas hydrate was produced for the first time by both depressurizing and heating the reservoir. Depressurization alone appeared to be the most-feasible method for producing gas hydrates. However, because of the limited nature and duration of the 2002 tests, it was determined that a longer duration test would be required, leading to the 2007-08 research program.
A 12-m-thick sand-rich hydrate-bearing reservoir was tested at a down-hole flowing pressure of approximately 7.3 MPa. The fact that gas hydrates can be produced by depressurization techniques was demonstrated. The winter 2006 operations included a 6-day depressurization flow, which was able to establish a sustained and stable gas flow rate averaging approximately 3000 m3/d. The total volume of gas and water produced over the duration of the test was approximately 13 000 and 100 m3, respectively.
Alaska North Slope (US)
The occurrence of gas hydrate on the Alaska North Slope is associated closely with well-characterized petroleum systems. The Mount Elbert gas hydrate test well, in 2007, showed a mobile water phase within hydrate-bearing reservoirs even at very high gas hydrate saturations. The recognition of the presence of a mobile water phase within gas hydrate reservoirs was an important development in that it provided the means, or pathway, to draw the pressure down on hydrate-bearing reservoirs. The PBU L-Pad area was identified as the optimal site for the subsequent Iġnik Sikumi gas hydrate production test.
Machine-Learning Image Recognition Enhances Rock Classification
Authors: Carpenter Chris 
Published: November 2020

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 196657, “Machine Learning for 3D Image Recognition To Determine Porosity and Lithology of Heterogeneous Carbonate Rock,” by Omar Al-Farisi, SPE, Hongtao Zhang, and Aikifa Raza, Khalifa University of Science and Technology, prepared for the 2019 SPE Reservoir Characterization and Simulation Conference and Exhibition, Abu Dhabi, 17-19 September. The paper has not been peer reviewed.
Automated image-processing algorithms can improve the quality and speed in classifying the morphology of heterogeneous carbonate rock. Several commercial products have produced petrophysical properties from 2D images and, to a lesser extent, from 3D images. Images are mainly microcomputed tomography (μCT), optical images of thin sections, or magnetic resonance images (MRI). However, most successful work is from homogeneous and clastic rocks. In the complete paper, the authors have demonstrated a machine-learning-assisted image-recognition (MLIR) approach to determine the porosity and lithology of heterogeneous carbonate rock by analyzing 3D images from µCT and MRI.
Introduction
The authors’ literature review has revealed the pressing need to perform 3D image processing instead of 2D. Achieving this goal requires an interdisciplinary approach. This study deployed new analysis and verification approaches, including 3D micromodels (3DMM) with various micropore sizes and uses 3DMM as an image-processing calibration reference. Additionally, a new image-resolution enhancement for quality segmentation is developed. Porosity was determined mainly using two methods. The first is a standalone image processing, in which image-information extraction was successful. The second is MLIR. The difference between image processing and image analysis is important. If image processing enables extraction of meaningful data, then image analysis is the ability to interpret this data through numerical analysis.
Technology Focus: Sand Management (October 2020)
Authors: Abbasy Imran 
Published: November 2020

Our industry currently is challenged with developing more and more complex and difficult-to-produce reservoirs. Exploration and production companies are now compelled to develop assets that were not deemed viable in the past. Deepwater, remote, deep, hot, and viscous oil comes to mind; however, sand-producing reservoirs also rank high on this list. As reservoirs age, sand production becomes more difficult to manage, and is perhaps one of the most-difficult tasks engineers face today.
Sand control has evolved over the years; however, the fundamentals of screen sizing have not changed. Particle-size distribution remains the basis for most designs. Laser diffraction has provided better definition of fines, and greater focus is placed now on particle-shape characterization. For those of you interested in delving into these topics, paper SPE 199335 provides a good overview. Testing remains a key element of any sand-control endeavor. Several derivatives of screens are now on the market; however, the original wire-wrapped screens are still used extensively. The so-called segmented completions are a relatively new addition to the engineer’s arsenal. Splitting the wellbore into several sections, along with flow-control devices, offers benefits where heterogeneities are prevalent. Several operators have attempted through-tubing sand remediations - consolidation, gravel pack, straddle screens - with mixed results. Suffice to say, every job is unique and must be engineered as such. Job planning is the key.
Technology trends that hold promise include materials that conform to the borehole behind screens (i.e., shape-memory polymer) and downhole wireline logs to identify sand-producing intervals. To date, these technologies are not as mature as one would like. During my time as a production technologist, I craved these tools and did not have them. I’m glad to see this is beginning to change.
A final thought: Keep your sand control simple if you can. Complex is not necessarily better. I have managed to flow unconsolidated sands with simple slotted liners with great success.
Special Considerations for Well Tubular Design at Elevated Temperatures
Authors: Tao Gang , Matthews Cam , Adams Adrian 
Published: November 2020

Summary
Understanding of material properties for tubular design under high-pressure/high-temperature (HP/HT) conditions goes well beyond the basics of the classic methods routinely used in the industry. Coupon test results of high-strength tubulars commonly used in HP/HT wells are presented to demonstrate the temperature and strain-rate dependencies of the stress-strain response. Based on the coupon test results, analytical equations and advanced nonlinear Finite Element Analysis (FEA) are used to illustrate the substantial impact that the temperature and rate-dependent material properties have on pipe body and connection performance in HP/HT applications. This paper raises an awareness of the importance of strain-rate effects, and recommendations are made on a few special considerations to account for these effects in well tubular design for elevated temperature applications. In addition, the findings also provide the basis for a critical discussion of the applicable American Society for Testing and Materials (ASTM)/American Petroleum Institute (API) test standards and the need to understand the effect of different strain/loading rates that may be used in material characterization and full-scale testing of tubular products at elevated temperatures. Collectively the information and results presented in the paper are expected to be very useful to the new generation of engineers charged with the tubular design for challenging well applications involving elevated temperature and severe load conditions.
Pregnancy outcomes of Chinese women undergoing IVF with embryonic cryopreservation as compared to natural conception
Authors: wang jingxue , liu qiwei , Deng Boer , chen fang , liu xiaowei , cheng jiumei 
Published: November 2020

Abstract
Background: To examine differences in the maternal characteristics and pregnancy outcomes of Chinese women with various causes of infertility who underwent in vitro fertilization (IVF) with embryonic cryopreservation treatment.Methods: Cases were pregnancies after IVF-ET with embryonic cryopreservation; controls were spontaneously conceived pregnancies. Subgroup analysis was carried out according to etiology of infertility. The IVF treatment group was divided into 5 subgroups according to infertility etiology as follows: ovulation disorder, tubal disease, male infertility, endometriosis, and mixed infertility. Data on demographic characteristics, medical history, laboratory tests, and delivery were reviewed. Logistic regression analysis was performed for pregnancy and perinatal complications and neonatal outcomes. The multivariable model was adjusted for potential confounders.Results: Among singleton pregnancies, compared with spontaneous pregnancies, IVF pregnancies were associated with significant increases in the rates of the following: gestational diabetes mellitus (GDM) (aOR 1.76[95% CI 1.33-2.33]), preeclampsia (2.60[1.61-4.20]), preterm preeclampsia (4.52[2.03-10.06]), postpartum hemorrhage (1.57[1.04-2.36]), intrahepatic cholestasis of pregnancy (3.84[1.06-13.94]), preterm premature rupture of membranes (2.11[1.17-3.81]), preterm birth (1.95[CI 1.26-3.01]), low birthweight (1.90[1.13-3.20]), macrosomia (1.53[1.03-2.27]), and neonatal intensive care unit (NICU) admission (1.69[1.22-2.34]) in the ovulation disorder group; GDM (1.50[1.21-1.86]), placenta previa (2.70[1.59-4.59]), placenta accreta (1.78[1.10-2.89]), postpartum hemorrhage (1.61[1.19-2.18]), macrosomia (1.60[1.21-2.13]) and 5-minute Apgar score ≤7 (4.09[1.04-16.08]) in the tubal disease group; placenta previa (9.33[4.22-20.62]), small for gestational age (2.29[1.04-5.08]), macrosomia (2.00[1.02-3.95]) and NICU admission (2.35[1.35-4.09]) in the endometriosis group; placenta previa (4.14[2.23-7.68]) and placenta accreta (2.05[1.08-3.87]) in the male infertility group; and GDM (1.85[1.15-2.98]), placenta previa (4.73[1.83-12.21]), placental abruption (3.39[1.20-9.56]), chorioamnionitis (2.93[1.04-8.26]), preterm birth (2.69[1.41-5.15]), and 1-minute Apgar score ≤7 (4.68[1.62-13.51]) in the mixed infertility group. Among multiple pregnancies, most of the differences that were significant in singleton pregnancies were less extensive or had disappeared.Conclusions: Infertility etiology within the IVF population was found to affect maternal and neonatal outcomes among all births. During the perinatal period, infertility etiology appears to be an additional risk factor for abnormal pregnancy outcomes besides the use of IVF techniques compared with spontaneous pregnancies. Higher risk was found for ovulation disorders, and lower risk was found for male infertility.
Geriatricians’ Standpoint of the Informed Consent Process Among Patients with Alzheimer's Disease: The Lebanese Context
Authors: Fakhro MPH DPT PT Mohammed Ali 
Published: November 2020

Abstract
BackgroundDespite the existence of laws that ensure that patients’ capacity to consent is assessed systematically, many gray areas remain with that regard. As dementia progresses, some patients lose their capacity to make decisions. This study aimed to investigate the geriatricians’ understanding of the principle of autonomy and their perception of the decision-making capacity (DMC) testing as part of the informed consent (IC) process among patients with AD. Proposing an algorithm for a reliable, comprehensive, and valid assessment of DMC was the secondary aim of this study.MethodsA cross-sectional descriptive study was designed to empirically collect data via an e-survey. Accordingly, a comprehensive list of geriatricians was provided by the Lebanese Order of Physicians. Geriatricians were approached via a phone call, to provide them with study-specific information. Those who accepted to participate received a link to the study’s survey via an e-mail.ResultsAmong the eligible geriatricians, 75% had completed the e-survey, with a mean of 14.7 ± 9.6 years of experience. More than half of the geriatricians failed to recognize that assessing the patients’ DMC is an integral component of the informed consent (IC) process. Yet, 88.9% assessed the DMC of their patients with AD using different modalities. However, the majority were unable to justify their judgment of DMC based on the tools they have selected.ConclusionLebanese geriatricians have demonstrated a poor understanding of the concept of autonomy and failed to recognize the need for the DMC assessment as a component of the IC’s process. Moreover, they were unable to select adequate tools to assess and judge the DMC of their patients with AD.
Characteristics of Resting-State Functional Connectivity in Older Adults after the PICMOR Intervention Program: A Preliminary Report
Authors: Sugimoto Hikaru , Kawagoe Toshikazu , Otake-Matsuura Mihoko 
Published: November 2020

Abstract
Background: The present study aimed to provide a basis for future research examining the neural mechanisms that underlie the beneficial effect of an intervention program, Photo-Integrated Conversation Moderated by Robots (PICMOR), on verbal fluency in older adults as identified in our previous randomized controlled trial. In this preliminary report, we conducted an additional experiment using resting-state functional magnetic resonance imaging (rsfMRI) after the intervention period. Specifically, we investigated the resting-state functional connectivity (rsFC) characteristics of the intervention group (INT) compared to the control group (CONT). Methods: rsfMRI data were acquired from 31 and 30 participants in INT and CONT, respectively, after the intervention. In the analyses, two of the most important regions in verbal fluency, the left inferior and middle frontal gyri, were selected as seed regions, and the rsFCs were compared between groups. We also conducted regression analyses for rsFCs using the difference in individual phonemic verbal fluency task (PVFT) scores between the pre- and post-intervention periods (i.e., post- minus pre-intervention) as an independent variable. Results: We found higher rsFC in INT than in CONT between the left inferior frontal gyrus as a seed region and the temporal pole and middle frontal gyrus. The rsFC strength between the left inferior frontal gyrus and temporal pole positively correlated with an increased PVFT score between the pre- and post-intervention periods. In contrast, we found lower rsFC in INT than in CONT between the left middle frontal gyrus as a seed region and the posterior cingulate cortex, precuneus, and postcentral gyrus. Conclusions: Our findings suggest that the beneficial intervention effect of PICMOR on verbal fluency is characterized by enhanced rsFC of the left inferior frontal gyrus with semantic and executive control-related regions and suppressed rsFC between the left middle frontal gyrus and posterior cortical midline structures. No definitive conclusions can be made because of a lack of rsfMRI data before the intervention. However, this pilot study provides the candidates for rsFCs, reflecting the beneficial effects of PICMOR on the brain network involved in verbal fluency. Trial registration: The trial was retrospectively registered at the UMIN Clinical Trials Registry (UMIN000036667) (May 7th, 2019).
Optical coherence tomography angiography evaluation of the effects of phacoemulsification cataract surgery on macular hemodynamics in Chinese normal eyes
Authors: Jia Xinyu , Wei Yinjuan , Song Hui 
Published: November 2020

Abstract
Background: To quantitatively evaluate the possible effects of phacoemulsification cataract surgery on macular hemodynamics using optical coherence tomography angiography (OCTA). Methods: This was a prospective observational study. Superficial and deep macular vascular densities, as well as parameters of foveal avascular zone (FAZ), were measured preoperatively (baseline) and at 1 day, 1 week, and 4 weeks postoperatively in normal eyes (≥22 mm and ≤24 mm) of patients scheduled for phacoemulsification cataract surgery with intraocular lens implantation. The correlations between the rate of change of pre- and post-operative vascular densities and surgical parameters were analyzed. Results: A total of 123 eyes of 107 patients were included in this study. Compared to the baseline measurements, no statistically significant variation was found in macular vascular densities at 1 day after the surgery (P>0.05). Both superficial and deep macular vascular densities were significantly increased postoperatively at weeks 1 and week 4 (P<0.05; P<0.05), however no statistically significant differences were detected in any of the FAZ parameters between the baseline measurements and the entire follow-up period (P>0.05 for all). Also, no statistically significant correlations were established between main surgical parameters and macular vascular densities changes. Conclusions: In normal eyes, macular blood perfusion gradually increased after phacoemulsification cataract surgery and was stabilized in one week. The foveal avascular zone was stabilized before and after the surgery. The main parameters and intraoperative perfusion of phacoemulsification surgery may not be the key factors affecting macular hemodynamics.
The role of chalcogen vacancies for atomic defect emission in MoS2
Authors: Mitterreiter Elmar , Schuler Bruno , Barthelmi Katja , Cochrane Katherine , Kiemle Jonas , Sigger Florian , Klein Julian , Wong Ed , Barnard Edward , Refaely-Abramson Sivan , Qiu Diana , Lorke Michael , Jahnke Frank , Watanabe Kenji , Taniguchi Takashi , Finley Jonathan , Schwartzberg Adam , Holleitner Alexander , Weber-Bargioni Alexander , Kastl Christoph 
Published: November 2020

Abstract
For two-dimensional (2D) layered semiconductors, control over atomic defects and understanding of their electronic and optical functionality represent major challenges towards developing a mature semiconductor technology using such materials. Here, we correlate generation, optical spectroscopy, atomic resolution imaging, and ab-initio theory of chalcogen vacancies in monolayer MoS2. Chalcogen vacancies are selectively generated by in-vacuo annealing, but also focused ion beam exposure. The defect generation rate, atomic imaging and the optical signatures support this claim. We discriminate the narrow linewidth photoluminescence signatures of vacancies, resulting predominantly from localized defect orbitals, from broad luminescence features in the same spectral range, resulting from adsorbates. Vacancies can be patterned with a precision below 10 nm by ion beams, show single photon emission, and open the possibility for advanced defect engineering of 2D semiconductors at the ultimate scale.
Disentangling water, ion and polymer dynamics in an anion exchange membrane
Authors: Foglia Fabrizia , Berrod Quentin , Gebel Gérard , Sakai V. , Appel Markus , Zanotti Jean-Marc , Tyagi Madhu Sudan , Mahmoudi Najet , Clancy Adam , Miller Thomas , Smith Keenan , Brett Dan , Shearing Paul , Lyonnard Sandrine , McMillan Paul 
Published: November 2020

Abstract
Fuel cells that generate electrical power by the direct electrochemical conversion of fuel to electricity are expected to become important sustainable energy sources for transportation and stationary applications. Polymer electrolyte membrane fuel cell (PEMFC) systems operating with oxygen and hydrogen or bio-derived fuels require an ion exchange membrane to transport H+ or OH- ions between the anode and cathode. Proton conduction in Nafion membranes is well studied. However these PEMFC systems rely on noble metal electrocatalysts due to the corrosive nature of the acidic electrolyte. An alkaline electrolyte allows non-noble catalysts to be used at the cathode, leading to reduced cost and enhanced sustainability. Understanding OH- transport and how it influences water management and polymer dynamics in anion exchange membranes (AEMs) is a critical design challenge and design parameter. Here, neutron scattering is used to disentangle the water, polymer relaxation and OH- diffusion dynamics in a commercial AEM system
Acceptance and Completion of Rifapentine-Based TB Preventive Therapy (3HP) Among People Living with HIV (PLHIV) in Kampala, Uganda – Patient and health Worker Perspectives.
Authors: Semitala Fred C , Musinguzi Allan , Ssemata Jackie , Welishe Fred , Nabunje Juliet , Kadota Jillian L. , Berger Christopher A. , Katamba Achilles , Kiwanuka Noah , Kamya Moses R. , Dowdy David , Cattamanchi Adithya , Katahoire Anne R. 
Published: November 2020

Abstract
BackgroundA 12-dose, once-weekly regimen of isoniazid and rifapentine (3HP) is effective in preventing tuberculosis (TB) among people living with HIV (PLHIV). We sought to identify potential barriers to and facilitators of 3HP implementation from the perspective of PLHIV and health workers in a routine HIV care setting in Kampala, Uganda.MethodsWe conducted semi-structured interviews with 25 PLHIV and 10 health workers at an HIV/AIDS clinic in Kampala, Uganda. For both groups, we explored their understanding and interpretations of TB and TB preventive therapy (TPT), and perceptions about social and contextual factors that might influence willingness of PLHIV to initiate and complete 3HP. We analyzed the data using an inductive thematic approach and aligned the emergent themes to the Behavior Change Wheel framework to identify sources of behavior and targeted behavior change interventions.ResultsFacilitators for uptake and completion of 3HP among PLHIV were fear of contracting TB, awareness of being potentially at risk of getting TB, willingness to take TPT, trust in health workers, and the perceived benefits of DOT and SAT. Barriers included inadequate understanding of TPT, fear of potential side effects, concerns about effectiveness of 3HP as well as the perceived challenges of DOT or SAT. Among health workers, perceived facilitators included knowledge that TB is a common cause of mortality, fear of getting TB, patient trust in their health workers, potential for once-weekly dosing and the benefits of TPT delivery. Health workers perceived potential barriers for PLHIV as being: inadequate understanding of TB and TPT, TB associated stigma, potential side effects, pill burden and challenges of taking TPT. Additional barriers included a lack of experience among health workers with the use of digital technology to monitor patient care.Conclusions Using a formative qualitative and comprehensive theoretical approach, we identified key sources of behavior that could be used to guide selection of appropriate intervention to optimize 3HP scale up among PLHIV in high burden settings.