bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Shrinking and Expanding Eastern Africa Rift Valley Lakes: The Case of Ethiopian and Kenyan Rift Valley Lakes: Review
Authors: Gebreegziabher Gizaw Abera Abera , Degefa Sileshi , Furi Wakgari 
Published: September 2023

Morphological study of lakes defines the sensitivity of their watershed. Moreover, it plays important role in safeguarding the lake’s ecosystem services through proper planning and utilization of the lakes’ resources. In the last few decades, the morphology of lakes in Ethiopian and Kenyan Rift (EKR) valley are experiencing contradicting morphological changes. Being in the same system, some are shrinking and others are expanding beyond their natural boundaries.
The objective of this review is to shed light on the trends in spatio-temporal water level fluctuation and their contributing factors for lakes to the academia and decision makers. Peer reviewed article journals, conference proceedings, thesis, and book chapters collected from online sources and supplied by authors on request formed a database of 346 documents where 226 are critically assessed.
The review indicated that lakes in Ethiopian rift are shrinking and expanding, while Kenyan lakes are expanding. The en-dorheic lakes suffered the most fluctuations due to anthropogenic factors at the expense of loss of forest and woodlands in their watershed. While the lakes’ water quality related to the morphological changes are given less attention, the predicted 12 m drop of Lake Turkana due to projects in the Omo catchment did not materialize.
A Failsafe Method of Preventing Voltage Generation During Installation and Pulling of ESPs with Permanent Magnet Motors
Authors: Ken Saveth , Charles Booth , Mauricio Oviedo , Dennis Harris 
Published: September 2023

Abstract
With the increased use of permanent magnet motors (PMM) versus less efficient induction motors (IM) comes an increased safety risk. While both the IM and PMM can generate power themselves if their shaft is turned by external forces, the induction motor cannot generate enough power to require additional safety procedures. The PMM when spinning at 2,000 rpm can generate up to 240 volts to create a tremendous safety risk when one considers voltage over 50 volts can be lethal.
The objectives/scope of this paper is to present an alternative method of preventing the shaft of a Permanent Magnet Motor (PMM) from rotating during the install and pull process. The result of implementing this method is the creation of safer working conditions for the field technician. The alternative method presented here utilizes a mechanical lock to physically secure the shaft thereby preventing it from rotating while the lock is in place.
The mechanical lock mechanism is secured to the top end of the equipment string with the lock engaged during the installation of the Electric Submersible Pump (ESP) string. Once the motor is powered, the force generated automatically unlocks the shaft to allow for the normal operation of the ESP. To engage the lock for the pulling of the ESP string, a heavy weight is lowered on top of the shaft lock.
The two present methods to prevent the pump shaft from rotating while installing or pulling are shunting of the cable and plugging the production tubing. Shunting involves tying all three phases of the cable together to short circuit the electrical system. However, the potential to rotate still exists, but requires an extremely large force. Plugging the production tubing contains the fluid column's potential energy from flowing back through the ESP, but this too has its completion and operational issues. The mechanical shaft lock method described in this paper uses shear pins that physically lock the shaft to prevent it from rotating. Only the mechanical motor horsepower has enough force to shear the pins loose; downhole pressure is not enough. Utilizing a PMM mechanical lock mechanism will physically prevent the shaft from rotating while installing or pulling a PMM-ESP string to provide a failsafe method to prevent potentially fatal conditions.
Exploratory Analysis of Electrical Submersible Pumps in Permian Unconventional Wells
Authors: Grohman Lonnie , Morgan Colter , Gamboa Jose 
Published: September 2023

Abstract
The aim of this study is to introduce a framework for the determination of ESP application ranges based on exploratory data analysis (EDA). EDA is carried out over a dataset that includes liquid rate, gas rate, oil rate, gas oil ratio (GOR), gas liquid ratio (GLR), and intake pressure among other variables from more than 100 wells that produce from 9 different reservoirs in the Midland Basin. The dataset contains production records from 30 different ESP pump arrangements. Details about the data cleaning process are provided, including outliner detection. Probability (PDF) and cumulative density functions (CDF) are presented, which are calculated for the entire ESP population and specific pumps models. The application range is determined from data quartile analysis. The results show that most data distribution is positive skew with long right tail, which implies that mean and standard deviation are not sufficient to describe the data range. The application range between different pump models is presented and time dependence of these ranges is demonstrated. K-means unsupervised classification method is then applied to group the data into six groups. Pump models are then identified in some of these groups from the analysis.
A Game Changer: Initiating a Massive Movement of Permanent Magnet Motor Application for ESP Design in Remote Area Operation, Sangasanga Oil Field Indonesia
Authors: Ridlah M. R. , Amal P. I. , Wibowo A. T. , Hidayat T. R. , Almadani N. , Prasetyo G. , Irawan G. , Hutomo T. 
Published: September 2023

Abstract
The application of electric submersible pumps by transforming kinetic energy into boosting pressure is widely recognized in optimizing well performance. However, it becomes challenging under remote area operations due to limited electric power supply resources. Power supply failures result in additional pump maintenance, thus shortening ESP run life and increasing operational costs eventually. This paper will introduce a solution to this challenge, i.e., innovative permanent magnet motor technology (PMM), and present successful PMM applications in the ESP system to reduce power consumption and prevent ESP failure in a mature oil field in Sangasanga, Indonesia.
Permanent magnet motor (PMM) technology is designed with magnetic material and unique apparatus fo r in-situ re-magnetize to generate a constant rotor magnetic field, thus resulting in greater torque and maximum pump rotation and ultimately reducing the power consumption. In addition, it works under high downhole temperatures of up to 480F without de-magnetization risk. In a three-year study, ESP design with PMM technology was implemented in several oil wells. ESP performance is evaluated and compared by parameters, i.e., annual power consumption, ESP run life, and production sustainability. The parameters are presented for three different case studies which compare three production wells equipped with conventional AM motor and PPM motor.
The campaign for PMM installation was started in 2019. Now, 40 % of ESP wells in the Sangasanga field have been equipped with PMM. With conventional AM motors, the average power consumption for ESPs is around 117,582 kWh a year. The number decreases by about 24-30% with PMM. Meanwhile, the operating cost decreases linearly accordingly. Moreover, the installation of PMM shows a promising result in securing production sustainability since it prevents unplanned shutdowns due to power shortages. As a result, the improvement has delivered an additional value of about $ 111,650 for each well annually. In addition, compared to the conventional AM motor, ESP's run life has increased from 2.5 years to 3.5 years by using PMM. The decrease in electricity usage also creates a domino effect on carbon emissions for better environmental sustainability.
The achievement in this study has triggered a massive campaign for a near future project to replace other remaining 60% of conventional AM motor ESPs with PMM technology. Furthermore, an additional power source must be provided to root the artificial lift conversion campaign from the Sucker Rod Pump to ESP to escalate oil production in Sangasanga Field.
New High Performance ESP Gas Separator
Authors: Nicholson Barry , Harryman Scott R. , Brown Donn J. , Sheth Ketan K. 
Published: September 2023

Abstract
This paper presents a new research method, design, and field testing of a new type of mechanical gas separator for electrical submersible pump systems (ESPs) that increases the operating flow range and separation efficiency while decreasing erosion problems and improving reliability.
A state-of-the-art test system was developed to view the internal workings and measure two-phase flow through mechanical separation devices to understand flow paths, recirculation, and separation efficiency, along with the collective and individual performance of various components of a gas separator. The result, a new "helical" design with optimized throughput, has a significant increase in total flow capacity, enhanced erosion protection, and improved gas locking prevention mechanisms.
Field tests of the new gas separators were conducted in conventional, unconventional, and CO2 flooded oil wells in the Permian Basin. Performance was evaluated by monitoring motor cooling, motor current fluctuations, intake pressure (drawdown), and wellhead pressure in wells with a high gas/liquid ratio (GLR) or gas volume fraction (GVF) and gas slugging. Cycling and continuous operations were compared for both conventional gas separators and the new gas separator to demonstrate the improved performance of the ESP in these well conditions.
The hydro-helical separator system is a new generation of downhole gas separator with a higher flow range, better gas separation efficiency, and reduced erosion, and has been proven to work in different types of wells.
ESP Continuous Deployment Monitoring System
Authors: Nicholson Barry , Yicon Carlos , Carreno Fernando , Navo Robert , Bodington Christian , Gutierrez Gibson 
Published: September 2023

Abstract
Electric submersible pumps (ESPs) using permanent magnet motors (PMMs) play a key role in lowering the cost of operations and reducing carbon footprint by reducing power consumption by 15 to 20%. As the use of PMMs becomes more prevalent, concerns about PMM safety are rising, especially during the installation and pull of the ESP system; hence, an automated method to monitor PMMs to safeguard personnel is essential. The ESP continuous deployment monitoring system (CDMS) prevents field personnel's exposure to electrical shock by acquiring and logging valuable downhole and surface measurements while installing or retrieving ESP systems. This tool both maintains the ESP system's electrical integrity and implements the two most important components of HSE: risk elimination and engineering control. Additionally, the device can alert the presence of any back electromotive force (BEMF) that may be generated. This system provides the ability to log the resistances between phases, between phase to ground, and downhole sensor readings without any physical contact with the ESP cable. In addition, this tool maintains the three phases of the ESP cable in short condition, reducing the chance of unplanned motor spinning. It also measures the ESP installation or retrieval operational efficiency. It eliminates the need to stop the operation regularly to measure the integrity of the ESP system. The CDMS is not intended to replace other safety considerations or procedures, but rather to complement them. This paper will illustrate the potential electrical hazards and the measures taken to ensure a safe ESP installation and retrieval during field tests and trials.
Trials of VSD Electrical Signature Analysis Technology for ESP Vibration in High Dog Leg Severity Wells at Surmont
Authors: Walters R. , Ehman K. , Olson K. , O'Reilly A. , Chacin J. , Nespor K. , Badkoubeh A. , Imanfard M. 
Published: September 2023

Abstract
ESPs operating in high dog leg severity (DLS) wells are prone to bending loads and vibration levels that may contribute to early failure modes such as shorted motor stators, rotor strikes and shaft breaks. Electrical signature analysis (ESA) has recently shown potential to identify the operating state of an ESP by analyzing high frequency data (current and voltage) captured at the variable speed drive (VSD).
This paper shows how ESA helped identify the vibration under bending state on three ESPs installed sequentially in a well where the two previous ESP installs had failed prematurely. The premature failures occurred at a high DLS pump setting depth due to rotor strikes under bending. ESA contributed to an enhanced understanding of the operating conditions of ESPs and, in conjunction with other changes (such as ESP length, pump setting depth and operating frequency), helped to significantly extend the runtime of ESPs in this challenging well.
Fighting, Mitigating, and Surviving Againstasphaltenes with a Special Electrical Submersible Pump Design
Authors: Leon C. H. , Escobar Ardila C. H. , Perez L. M. 
Published: September 2023

Abstract
Over the years, Electric submersible pumps have been proven to be a reliable artificial lift method in different fields of the world for a broad range of flow production and different well fluid types. However, harsh environment such as heavy oil, high temperature, asphaltene formation and severe fluid properties generate problems inside the equipment reducing their operating run life.
During the normal operation of the ESP, asphaltenes formation inside protectors are one of the major problems that the operators suffer and due to this, premature failure could occur. This failure usually follows the same pattern and consist in formation and accumulation of solids inside chambers, bags will collapse due to incorrect function of expansion and contraction of the oil due to temperatures (due to frequent shutdowns), and contamination though all internal chambers reaching thrust one, usually resulting in mechanical failure due to a shaft fatigue at the runner level or in an electrical failure due to motor contamination with well fluid. Chemical injection and low drop pressures have been considered to control this effect, however, there is not an ESP configuration developed to mitigate and combat to the presence of asphaltenes inside protector chambers.
The main objective of this paper is to share the results and conclusions of a full study that considers the main reasons for formation, accumulation, and mitigation of asphaltene effects inside ESP systems. This study explains in detail all the root failure analysis, laboratory investigation, R&D process and new ESP design solution, proved at laboratory and in field, that will allows the customerto extend the run life of the ESP systems.
A Review of Polymer Gel Utilization in Carbon Dioxide Flow Control at the Core and Field Scale
Authors: Brattekås Bergit , Seright Randall 
Published: September 2023

Summary
Polymer gel has been used for water conformance control for several decades and may have significant potential in remediating unfavorable carbon dioxide (CO2) flow in the subsurface. High-mobility CO2 may channel quickly through sedimentary reservoirs, where unfavorable displacements are worsened in the presence of heterogeneities. Flow diversion technology targeting and withstanding CO2 is therefore essential to improving sweep efficiency and increasing storage potential. Polymer gel treatments have been demonstrated to remediate CO2 channeling in several enhanced oil recovery (EOR) field applications and have been proposed as a means to remediate wellbore and seal leakage during carbon sequestration. The goal of this review is to assess CO2 conformance control by polymer gel in published laboratory work related to both storage and EOR operations. Although field implementation of polymer gel has been successful in reducing CO2 flow, supporting experimental work on the laboratory scale is scattered, with both results and parameters varied. This paper summarizes the available literature and proposes a framework for future experimental work to aid more systematic assessment.
Age-dependent topic modelling of comorbidities in UK Biobank identifies disease subtypes with differential genetic risk
Authors: Jiang Xilin 
Published: September 2023

Abstract
Age-dependent topic modelling (ATM) is a method for inferring comorbidity profiles for individuals at Biobank Scale. Details of the Method is available in the paper Age-dependent topic modelling of comorbidities in UK Biobank identifies disease subtypes with differential genetic risk.

ATM assigns to each individual topic weights for several disease topics; each disease topic reflects a set of diseases that tend to co-occur as a function of age, quantified by age-dependent topic loadings for each disease. The model assumes that for each disease diagnosis, a topic is sampled based on the individual’s topic weights (which sum to 1 across topics, for a given individual), and a disease is sampled based on the individual’s age and the age-dependent topic loadings (which sum to 1 across diseases, for a given topic at a given age). The model generalises the latent dirichlet allocation (LDA) model by allowing topic loadings for each topic to vary with age.

The ATM model is implemented as an R package, which is available for download at https://github.com/Xilin-Jiang/ATM/tree/main. We provide example simulated data so that users could easily test before formatting their data.
Optimization of microplate-based phenol-sulfuric acid method and application to the multi-sample measurements of cellulose nanofibers
Authors: Ogura Isamu , Sugiyama Miyuki , Tai Rie , Mano Hiroyuki , Matsuzawa Tomohiko 
Published: September 2023

Abstract
The phenol-sulfuric acid (PSA) method is a widely used colorimetric method for determining the total saccharides. Microplate-based PSA methods have been developed to handle a large number of samples and reduce the use of hazardous chemicals. However, the optimal procedures and measurement conditions for this method have not yet been fully established. To address this gap, we investigated the optimal procedure for microplate-based PSA. In addition to glucose (Glc), two types of cellulose nanofibers (CNFs) were also evaluated as they are a new type of nanomaterial, and a technique to quantify the concentration of CNFs is required in their safety assessment. The results showed that the thermal reaction with sulfuric acid before the addition of phenol resulted in a higher coloration than was shown after the addition of phenol. Furthermore, the longer the resting time after shaking with phenol, the greater the coloration and the smaller the variation, with a resting time of 60 min or longer being optimal. This research provides valuable insights into improving the reliability and efficiency of the PSA method, which can facilitate the analysis of saccharides and other substances in a range of applications.
Sakahanda: a Farming Management System Designed for Small-scale Crop Productions in the Municipality of San Ildefonso
Authors: Batoon Jayson , Raymundo Erika , Cruz Red Johnpaul , Custodio Eunice , Perez Timothy Ryeyn , Cabrito Khyla Nicole 
Published: September 2023

Abstract

Crop production is critical to the country's agricultural sector's growth, however, urban development and natural adversities such as typhoons, droughts, and pest infestations all pose a risk to crop production and the livelihood of small-scale farmers. With that, projects harnessing the potential of digital agriculture technologies are highly relevant. Due to this, the researchers developed SAKAHANDA, a farming management system consisting of an Android mobile app for the farmers and an administrative web app for the Municipal Agriculture Office of the Municipality of San Ildefonso. For the development, the developers adopted the agile software development methodology using the Kanban framework. Through the mobile application, farmers can manage their crops through farm management features partnered with smart weather forecasting, pest infestation reporting, and crops library with pest map. On the other hand, the admin web application has features designed to improve the efficiency of crop production in the municipality with features like farm monitoring, farm geotagging, farmer management, pest infestation management, and crops management. The results show a future for digital agriculture and other similar endeavors in the country. Furthermore, according to the evaluation based on Software Quality ISO 25010 standards, the results indicate that evaluators find the developed system and its features acceptable. It can help the farmers improve their crop production yields and help the MAO manage the municipal farming industry more effectively.
Prevalence and factors associated with respiratory symptoms in an urban population: findings from BOLD study in Karachi, Pakistan
Authors: Nafees Asaad Ahmed , Khan Adeel Ahmed , Rabbani Unaib , Zahidie Aysha , Ul Rooman , Irfan Muhammad , Amaral Andre FS 
Published: September 2023

Abstract
Background
Our study investigated the prevalence and risk factors of respiratory symptoms (RS) in an adult population aged ≥ 40 years in Karachi, Pakistan.
Methods
A population based cross-sectional study was conducted. Multi-stage cluster random sampling technique was used to enroll 1052 participants. Questionnaire based on the Burden of Obstructive Lung Disease (BOLD) study protocol was used to assess chronic cough, chronic phlegm, wheezing and shortness of breath (SOB). Logistic regression analyses were conducted to determine the risk factors associated with RS.
Results
The overall weighted prevalence of RS in our study was; chronic cough: 12%, chronic phlegm: 11.8%, wheezing in last 12 months: 11.5%, and shortness of breath (SOB): 30.4%. Increasing age and ever smoker were significant risk factors for all RS. Females had higher risk of chronic cough. Lower level of education and higher BMI were associated with wheezing and SOB. Exposure to passive smoking was found to be significant risk factor for SOB.
Conclusion
We found a higher prevalence of respiratory symptoms among adult population in Karachi, specifically about one-third of the population had shortness of breath (SOB). Certain preventable risk factors were identified. These modifiable risk factors can be addressed by targeted public health and educational interventions in order to reduce the burden of respiratory symptoms.