bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of Surfactant-Based Shale Oil EOR Under High Confining Pressure Conditions
Authors: Tu Jiawei 
Published: September 2019

Abstract
Surfactant-based EOR has thus far been demonstrated to be a potentially effective solution to improve the hydrocarbon recovery from Unconventional Oil Reservoirs (UORs). The most discussed functions of a surfactant are either Interfacial Tension (IFT) reduction or Wettability (WTA) Alteration. However, studies of the accountable effects for the enhanced production are inadequate because of the peculiar properties of shale matrix, such as the extremely low permeability and initial wetness. In addition, the current studies mainly focused on the spontaneous imbibition (SI) because of the long experimental period and limited pressure applicability with the existing experimental apparatus.
This work is to study the process of shale oil EOR by adding surfactant additives with high confining pressures applied to an in-house designed set-up. The applied pressure was as high as 3000 psi and the surfactant was selected with a spectrum of IFT values. Two operational schemes were conducted: Forced Imbibition (FI) and Cyclic Injection (CI). For the forced imbibition study, constant pressure was applied to the experimental set-up throughout the whole experimental period. The final recovery was recorded at the end of each test. The cyclic injection is also referred to as ‘huff-n-puff’ technique. The pressure is applied and released with a periodic schedule and the recoveries were recorded after each cycle by volume.
The results were compared with that of regular SI experiments. It is noticed that oil productions through the CI technique is mostly effective and efficient. In addition, WTB-alteration is the dominating mechanism in both pressurized and atmospheric pressure cases, while surprisingly, IFT-reduction could be detrimental for the recovery enhancement due to the low capillary pressure. The results gave indicative suggestions on the selection of surfactant and engineering application design for a surfactant based EOR project in shale oil reservoirs.
Randomness of Geophysical Log Data – Fractal Approach
Authors: Figiel Michal 
Published: September 2019

Abstract
Geophysical data allows for measuring a change in petrophysical parameters thought a whole well length. They often exhibit a chaotic behaviour which is difficult to describe and finding a pattern is near impossible. A potential measure of this chaos – correlation dimension – has been examined in the study.
The research was carried out for the log data from Williston Basin, USA and the Norwegian Lille-Frigg oil field on the North Sea. Sonic log (DT), neutron porosity log (NPHI), deep resistivity log (LLD) as well as density log (RHOB) were utilised in the study. A python program has been written to measure the change in correlation dimension. Instead of calculating a one value of a correlation dimension for a whole log, a moving range algorithm was developed and implemented. It is based on defining a range for which the dimension is calculated and then moving the range on a geophysical log. In addition, a graph representing change of a correlation dimension with depth is drawn. The influence of data range and range shift were measured. Over 100 correlations have been carried out between rock properties and their dimension.
The results indicate that the correlation dimensions change throughout the whole geophysical log and correlate with themselves and other curves in a moderate degree. It allows for determining ranges where a data set is not chaotic. The research shows that properly set range should have a reasonable and representative amount of data points, while the shift should be small for accurate results. Presented analysis creates perspectives for a more precise rock formation description and possible correlation between different oil wells within a single reservoir.
Assessment of Data-Driven Ensemble Methods for Conserving Wellbore Stability in Deviated Wells
Authors: Tewari Saurabh 
Published: September 2019

Abstract
Accurate estimation of mud weight (MW) helps to conserve wellbore stability in real-time drilling operations. Determination of proper MW requires a correct understanding of the stress field, natural fractures, pore pressure, rock strength, borehole trajectories, etc. It is a problematic task especially in, highly inclined wells, deviated wells, and near salt formations due to uneven variations in wellbore stresses. Proper MWs are difficult to apply at target depths of the unstable formations because of uncertainties existing inside the wellbore. There are no reliable tools or techniques available that can precisely determine the optimum value of MW. This paper proposes a novel and more convenient approach to estimate the safe MW for deviated wells using surface measured data. In this study, Bagging and Random forest ensembles have been utilized to model the relationship between sensors measured variables and MW. The proposed framework has been trained and tested on real-time Norwegian post-drilling data. Artificial neural networks (ANNs) and support vector regression (SVR) have also been utilized in this study for comparison purposes. The analysis of prediction results clearly reveals that Random forest ensemble has acquired the highest coefficient of correlation and minimum estimation errors. The performance of Ensemble methods is found to be superior to the ANNs and SVR models. The proposed approach can be useful for the determination of MW required at different depths of reservoir formation and maintaining the wellbore stability during real-time operations.
Investigating Factors that May Impact the Success of Carbon Dioxide Enhanced Oil Recovery in Shale Reservoirs
Authors: Fakher Sherif 
Published: September 2019

Abstract
Carbon dioxide (CO2) injection has recently been applied as an enhanced oil recovery (EOR) method to increase oil recovery from unconventional shale reservoirs. Many interactions will impact the success or failure of this EOR method. This research experimentally investigates the impact of two of these interactions, including asphaltene pore plugging and CO2 adsorption, on the success of CO2 EOR in unconventional shale reservoirs. Two sets of experiments were designed to study the asphaltene pore plugging and CO2 adsorption. The impact of varying CO2 injection pressure, temperature, oil viscosity, and filter membrane pore size on asphaltene pore plugging was investigated. Pertaining to the adsorption experiments, the impact of varying CO2 injection pressure, temperature, and shale particle size was investigated. Asphaltene pore plugging was found to be extremely severe especially in the smaller pore sizes, which indicates that asphaltene poses a serious problem when producing from unconventional nanopores. As the oil viscosity decreased, the asphaltene concentration in the oil decreased as well which made the asphaltene pore plugging less severe in the lower viscosity oils. The thermodynamic conditions, including pressure and temperature, also had a strong impact on asphaltene stability and pore plugging. When undergoing the CO2 adsorption experiments, it was found that increasing the CO2 injection pressure resulted in an increase in adsorption capacity to a certain limit beyond which no further adsorption will be possible. Increasing the temperature resulted in the CO2 molecules becoming highly active which in turn resulted in a decrease in the adsorption capacity significantly. Since experiments were conducted using shale particles, as opposed to an actual shale core, it was important to investigate the accuracy of the results by varying the shale particle size. It was found that as long as the void space volume was measured accurately using helium, the shale particle size had a negligible effect on the adsorption values. This research systematically investigates the impact of two significant interactions on the success of CO2 injection in unconventional shale reservoirs, and studies the impact of several factors within these interactions to determine the extent to which they may influence the success of this EOR method.
An Inferable Machine Learning Approach to Predicting PVT Properties of Niger Delta Crude Oil using Compositional Data
Authors: Sola-Aremu Oluwapelumi 
Published: September 2019

Abstract
Reservoir fluid characterization is critical to understanding the nature and phase behavior of reservoir fluids. This process has typically been undertaken using laboratory analyses, a time-intensive and costly process which also provides compositional data. Over time, correlations have been developed to predict the PVT properties of crude oil based on parameters such as solution gas-oil ratio, saturation pressure, viscosity, and density. These correlations have had shortcomings such as utilizing a leave-one-out approach, or recently, focused on non-inferable methods such as Neural Networks. This work utilizes compositional data, hitherto neglected in PVT correlations, as input into an inferable machine learning algorithm which can be used to predict PVT properties of crude oil from the Niger Delta basin.
Data containing bubble point pressure, solution gas-oil ratio, and oil formation volume factor alongside composition were obtained and used to develop models. Machine learning model training techniques such as data preprocessing, transformation and hyper-parameter tuning were undertaken. The elastic net regression algorithm utilizing a cross-validation approach was used to develop the models. This ensured an adequate bias-variance tradeoff.
The resulting models were compared with established correlations such as Standing & Katz. Upon statistical analyses performed comparably. The bubble point pressure model, solution gas-oil ratio, oil formation volume factor achieved R-squared value of 0.87, 0.95 and 0.84 respectively on the validation dataset. The models are expressed in the form of equations which can be used in petroleum engineering calculations or implemented in reservoir simulation software. By implementing this approach, a framework for utilizing machine learning for Petroleum Engineering problems which produces inferable results is established. Given potential discoveries in the Niger Delta, upon obtaining compositional data, these set of equations can be used to predict the reservoir crude oil PVT properties, leading to savings in time, cost, and effort, while obtaining actionable and accurate results.
Determinants and Seasonality of Major Structural Birth Defects Among Newborns Delivered at Primary and Referral Hospital of East and West Gojjam Zones, North West Ethiopia 2017- 2018: Case- Control Study
Authors: Tsehay Binalfew , Shitie Desalegn , Lake Akilog , Abebaw Erimiyas , Taye Amisalu , Essa Enatinesh 
Published: September 2019

Abstract
Objective: Although infant mortality because of birth defect has increased in both developed and developing countries, had not got attention like other health issues at national, regional, or local levels. Documenting the risk factors that influence the occurrence of birth defects and its seasonality will help to inform the community and to develop preventive strategies for the country.
Results: Factors associated with higher likelihood of a major structural birth defects included maternal age; neonates born from women living in urban; and in Dega; history of fever during pregnancy; intake of herbal medicine; and drinking alcohol. Counselling for pregnancy preparation and folic acid supplementation was found protective for the likelihood of birth defect.
Key words: Birth defect, maternal illness, maternal medication use, environmental exposure
Identifying asymptomatic Leishmania infections in non-endemic villages in Gedaref state, Sudan.
Authors: Mohamed Nouh Saad , Osman Hussam A. , Muneer Mohamed S. , Samy Abdallah M. , Ahmed Ayman , Mohammed Anwar O. , Siddig Emmanuel Edwar , Hamid Muzamil M. Abdel , Ali Mohamed Siralkhatim , Omer Rihab Ali , Elaagip Arwa H. 
Published: September 2019

Abstract
Objectives: Infection with the causative agent of visceral leishmaniasis (VL) may be either symptomatic or asymptomatic. In this study we aimed at investigating the prevalence of asymptomatic infections of leishmania in non-endemic villages in Gedaref state, Sudan. A descriptive cross-sectional study conducted during September and October 2014. Blood samples were collected for serological and molecular analysis. Sticky-traps, knockdown spray and CDC-miniature light traps were used for the collection of sandflies.
Results: Ninety-Five participants were included; 52 from Abukishma, 15 Algadamblia Tirfa, 25 Abualnaja and 3 were from Algadamblia Aljabal . Females constituted 56 (58.9%) of the study participants while males were 39 (41.1%). The most frequent age group was >40-years (54.7%). Balanites/Acacia trees were the most planted tree inside the houses; 78 (82.1%). Also, 85 (89.5%) of the participants breed animals inside the house. DAT test revealed 5 positive participants (5.2%). 4/5 DAT positive were past VL infection. PCR detected 35 (36.8%) positive participants. A total of 31/35 was considered asymptomatic infections based on PCR. Households planted Balanites/Acacia trees or breed domestic animals were found in high percentages with L. donovani PCR positive participants (60.1%, 91.4%). No statistically significant was found for VL associated risk factors and VL asymptomatic participants.
Transcriptome analysis of low phosphate stress response in the roots of masson pine (Pinus massoniana) seedlings
Authors: Pan Xiaocheng , Hu Haibo 
Published: September 2019

Abstract
Background: Masson pine (Pinus massoniana) is primarily present within subtropical and tropical areas in China, and a number of these regions have a severe deficiency in inorganic phosphate (Pi). As a macronutrient, phosphorus plays a crucial role in plant development. Although several studies have studied the responses of masson pine to Pi starvation at the global level using RNA-Seq and comparative proteomic analyses, the detailed features in the roots that primarily respond to low Pi stress have not yet been studied. Results: This study examined the masson pine of the response of masson pine roots to a deficiency in Pi. Approximately 1,117 unigenes were shown to respond to Pi-deficiency by differential expression when analyzed using RNA-Seq. A total of 819 and 298 of these transcripts were up- and down-regulated, respectively. The results identified several phosphate transporters (PHT1, PHO88), ABC transporters and metal transporters. In particular, the ethylene response factor (ERF) was the most abundant transcription factor. Analyses of these genes, including gene ontology enrichment and the KEGG pathway analysis, indicated that the metabolic processes are the most enriched under abiotic stresses, including Pi-deficiency. Conclusions: This study provided abundant transcriptomic information to functionally dissect the response of masson pine roots to a deficiency of Pi, which will provide additional aid to elucidate the biological regulatory mechanisms that the pines use to respond to low Pi stress.
Transcript profiles of stria vascularis in models of Waardenburg syndrome
Authors: Chen Linjun , Wang Yi , Chen Lei , Wang Fangyuan , Ji Fe , Sun Wei , Zhao Hui , Han Weiju 
Published: September 2019

Abstract
Background: Waardenburg syndrome is a common syndromic hereditary deafness disease caused by stria vascularis dysfunction. However, the genetic pathway affecting stria vascularis development is still not clear. In this paper, the transcript profile of stria vascularis of Waardenburg syndrome was studied using Mitf-M mutant pigs and mice models. GO analysis was performed to identify the differential gene expression caused by Mitf-M mutation. Results: There were over than one hundred genes mainly found in tyrosine metabolism, melanin formation and ion transportations showed significant changes in both models. In addition, there were some spiced specific gene changes in the stria vascularis in the mouse and porcine models. The expression of tight junction-associated genes, including Cadm1, Cldn11, Pcdh1, Pcdh19 and Cdh24 genes, were significantly higher in porcine models compared to mouse models. Vascular-related and ion channel-related genes in the stria vascularis were also shown significantly difference between the two species. The expression of Col2a1, Col3a1, Col11a1 and Col11a2 genes were higher and the expression of Col8a2, Cd34 and Ncam genes were lower in the porcine model compared to mouse model. In both models, Trpm1, Kcnj13, and Slc45a2 genes were both affected by the Mitf-M mutation. In the pig models, the expression of Kcnn1, Clcn2 and Trpm4 genes were higher than the mouse model; whereas the expression of Trpm7, Kcnq1 and Kcnj8 genes were higher in the mouse models than the pig models. However, there was no significant difference in the morphology of the stria vascularis between these two models. Conclusions: Our data suggests that there is a significant difference on the gene expression and function between these two models.
The efficacy of superior oblique posterior tenotomy in the treatment of A-pattern strabismus without ocular intorsion: A retrospective study
Authors: Wei Yan , Dong Ling-Yan , Kang Xiao-li 
Published: September 2019

Abstract
Background: Superior oblique weakening is a common method to treat A-pattern strabismus. This study aim to evaluate the surgical results of superior oblique posterior tenotomy procedures to treat A-pattern strabismus patients who had bilateral superior oblique overaction without ocular objective intorsion.Methods: The records of 18 consecutive patients who underwent surgery of superior oblique posterior tenotomy close to its insertion with superior oblique overaction (SOOA)-associated A-pattern strabismus between September 1, 2015 and August 31, 2018 were retrospectively reviewed. Ocular alignment, objective torsion, A-pattern and ocular motility were assessed. Ocular alignment was measured in the primary position, 25° upgaze, and 25° downgaze using the prism bar cover test, and torsion was measured using fundus photographs. Results: A total of 18 patients (mean age: 15 years; 6 female, 12 male) underwent bilateral superior oblique posterior tenotomy and simultaneous horizontal rectus muscle surgery were included. The mean preoperative A-pattern deviation was 15 PD and the mean postoperative A-pattern deviation was 2.25 PD with a mean reduction of 12.75 PD. The mean preoperative superior oblique overaction was 2.28 and the mean postoperative superior oblique overaction was 0.43 with a mean reduction of 1.85. There was no significant correlation between the ocular torsional, vertical and horizontal alignment change and the superior oblique posterior tenotomy procedure. Conclusions: Superior oblique posterior tenotomy surgery selectively improved the A-pattern and superior oblique overaction but not affect the primary position vertical and horizontal deviation, as well as the ocular torsion. So it is an effective procedure to treat the mild to moderate superior oblique overaction (SOOA)-associated A pattern strabismus without ocular intorsion.
3D printing navigation template used in total hip arthroplasty for developmental dysplasia of the hip
Authors: yan liang , Wang Peng , Zhou Haibing 
Published: September 2019

Abstract
Background: It is difficult to locate the real acetabulum in the total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH), The goal of this study was to explore the application of 3D printing navigation template used in total hip arthroplasty (THA) for developmental dysplasia of the hip. Methods: Between February 2017 and May 2018, THAs were performed in 25 patients with DDH, all patients (12 cases undergoing THA with 3D printing navigation template, 13 cases undergoing traditional THA) were followed-up for an average of 14.6 months. Surgical information and outcomes treated with different approaches were compared. Results: The 3D printing group provided shorter operation time, lower intra- and post-operative hemorrhage and higher post-operative Harris scores. postoperative infection and prosthetic loosening were 0 in two groups. There were no significant differences in anteversion angle, abduction angle and the distance from rotation center to the ischial tuberosity connection between ipsilateral and contralateral sides in 3D printing group. The abduction angle and the distance from rotation center to the ischial tuberosity connection were significantly different between the two sides in the traditional group. Conclusion: The finding suggests that 3D printing navigation template used in total hip arthroplasty is an individualized, accurate technology. Keywords: 3D printing technology, total hip arthroplasty, developmental dysplasia of the hip, navigation template
Knockdown of integrin subunit α 7 inhibits cell proliferation, invasion and promotes apoptosis via downregulating FAK/PI3K signaling pathway in hepatocellular carcinoma
Authors: Sun Jiangyang , Ying Chengcheng , Zheng Xiaolin , Cai Changchun 
Published: September 2019

Abstract
Background The study aimed to explore the effect of integrin subunit α 7 (ITGA7) knockdown on cell proliferation, apoptosis, invasion, and regulation of FAK/PI3K pathway in hepatocellular carcinoma (HCC).Methods ITGA7 mRNA and protein expressions were detected in HCC tumor tissues, adjacent tissues, HCC cell lines (including: Hep G2, BEL-7402, SMMC-7721, Huh-7 cell lines) and human liver epithelial cell line (THLE-3). The effect of ITGA7 knockdown on cell proliferation, apoptosis, invasion, expressions of FAK and PI3K were detected after transfection of ITGA7 small interfering RNA (siRNA) and control siRNA into Huh-7 cells.Results ITGA7 was upregulated in HCC tumor tissues compared with adjacent tissues, and increased in Hep G2, SMMC-7721 and Huh-7 cell lines while unchanged in BEL-7402 cell line compared with THLE-3 cell line. As for cell activities, ITGA7 knockdown inhibited cell proliferation, invasion but promoted apoptosis in Huh-7 cells. In addition, ITGA7 knockdown decreased the expressions of FAK and PI3K in Huh-7 cells, implying that ITGA7 knockdown might reduce HCC progression via inhibition of FAK/PI3K pathway in HCC.Conclusions ITGA7 is upregulated, and its knockdown inhibits cell proliferation, invasion but promotes apoptosis via suppression of FAK/PI3K signaling pathway in HCC, which implies that ITGA7 might serve as a potential treatment target for HCC.