bluuebunny/crossref_metadata_2025 huggingface dataset:
CO2 Utilization: Converting Waste into Valuable Products
Authors: Berahim Nor Hafizah , Abu Seman Akbar
Published: October 2022

Carbon dioxide capture, utilization, and storage (CCUS), which includes conversion to valuable products, is a complex modern issue with many perspectives. In recent years, the idea of using carbon dioxide (CO2) as a feedstock for synthetic applications in the chemical and fuel sectors via reduction reactions has piqued interest. If the hydrogen is created using a renewable energy source, catalytic CO2 hydrogenation is the most viable and appealing alternative among the existing CO2-recycling solutions. CO2 hydrogenation has many chemical paths depending on the catalyst, and multiple value-added hydrocarbons can be generated. This research looks into a catalyst development for converting high CO2 gas field into methane and alcohols. The study focused on catalytic conversion of CO2 to methane over Ru based catalyst while in the case of alcohols using Cu based catalyst. Both catalysts were synthesized via impregnation techniques where the aqueous precursors’ solution were impregnated on the oxide supports, stirred, filtered and washed. The samples were then dried, ground and calcined. The synthesized catalysts were characterized using various analytical techniques (e.g., TPR, FESEM, N2 adsorption-desorption, XRD) for their physicochemical properties. The catalytic performance in CO2 hydrogenation was performed using a fixed bed reactor at various factors such as temperature, pressure, feed gas ratio and space velocity. The experimental findings indicate that conversion of CO2 to methane over Ru based catalyst resulted in >84% CO2 conversion with 99% methane selectivity in the range of temperature 280 – 320 °C and at atmospheric pressure. In the case of hydrogenation of CO2 to alcohols, the catalytic performance of Cu based catalyst exhibited CO2 conversion of >11% and selectivity towards alcohols, C1 and C2, both at 4% with reaction temperature of 250 °C and pressure 30 bar. These findings revealed that methane could easily be formed from CO2 as compared to alcohol. However, both technology conversions are dependent on the catalyst selection and its’ activity. Process parameters need to be optimized to maximize targeted product formation and suppress the side products.
Mitigating Sand Production by Polymer Injection in Indonesian Offshore Field
Authors: Zaitoun Alain , Salehi Nazanin , Bouillot Jerome , Hernando Louis , Wijaya Budi Rivai , Reynold Winner , Samosir Frans Samuel , Pradipta Adrianus , Witjaksono Arief , Kurniadi Wery
Published: October 2022

Several fields in South East Asia are suffering from excessive sand production due to clayey unstable reservoir rock. Sand production induces undesirable phenomena such as production loss due to sand accumulation in the well, damage of the pump and of the surface equipment, frequent well shut-in and heavy costs for cleanout jobs and pump changes. The operators are looking for an easy and cost-effective technique that could be deployed in the field, if possible rigless.

In a previous paper5, a pilot treatment consisting of specific water-soluble polymer injection showed good results in terms of sand production reduction and preservation of well performances. The polymer adsorbs strongly on the reservoir rock, forming a continuous film on pore walls. The film has a consistency of thin sticky gel stabilizing the rock. Moreover, the polymeric film acts as Relative Permeability Modifiers (RPM) and thus maintain oil permeability while reducing water permeability. This RPM property enables the deployment by bullhead injection into the whole open interval.

Field extension has been scheduled and similar treatments have been performed in 4 new wells. In the field, the polymer is injected by coiled tubing in each open interval selectively. The polymer is pushed in the formation by diesel/water postflush, which also re-saturates with oil the near-wellbore area and help production re-start. The feedback obtained so far can be listed as follows: No production loss occurred in all the treated wells.Sand-free production rate could be increased after the polymer treatmentSand production was totally stopped for a few months before coming back again after 4-12 months, at much lower rate than before.A re-treatment induced new period of sand-free production for several months.

Such results confirm the sustainability of the polymer technology. The field methodology has been optimized. It opens new perspectives and could become a new sand control system in the toolbox of the profession.
Successful Use of Novel Bio-Based Surfactant Internal Ketone Sulfonate (IKS) Chemistry for Indonesian High Temperature Reservoir: Formulation Development to Oil Recovery Efficiency in Native Reservoir Core
Authors: Fauzi Iqbal , Sulistiyani Sri , Permadi Imam , Prasetyo Arif Bagus , Miyondri Dodi , Utami Anis Nurrachmania , Pasarai Usman , Wangge Yohanes B Doi , Eni Hestuti , Roy Sayak , Vidaillac Cyril
Published: October 2022

Growing national demand and declining or maturing fields in Indonesia have pushed the country to increase and accelerate efforts to improve production from the maturing fields by engaging various tertiary recovery techniques as one of the strategic pillars in achieving national target of 1 MMBOPD oil production in 2030. Several fields are being considered and being studied strategically as potential for application of chemical EOR technologies. High temperature reservoirs in Limau block of South-Sumatran basin is an onshore mature field which has been identified as a potential chemical EOR candidate. Due to higher reservoir temperature (>100°C) it is always challenging to develop a surfactant-based chemical EOR solution due to pronounced issues in chemical compatibility.

For any economical surfactant-based chemical EOR process an optimized surfactant or surfactant-polymer formulation needs to be developed in a laboratory which depicts good thermal stability, compatibility with polymer or injection water, exhibits ultra-low interfacial properties (<10−2 mN/m) with crude oil and injection water brine, lower surfactant adsorption and higher production of residual oil from the native reservoir core using shorter slug (< 1 PV of SP injection). In this current study, a detailed workflow was followed to successfully achieve the above key performance indicators (KPIs) for developing a tailor-made surfactant-polymer formulation in a high temperature (107° C) Limau field, which is always a massive challenge.

A multi-component surfactant formulation using the novel bio-based surfactant internal ketone sulfonate (IKS) as the primary surfactant was designed for high-temperature Limau reservoir. The detailed laboratory analysis shows that surfactant formulation along with polymer is able to exhibit a robust behaviour at the challenging reservoir condition. The detailed laboratory screening concludes that the designed robust SP formulation is able to induce ultra-low IFT (~1×10−3 mN/m), excellent solubility and compatibility at the injection water salinity, high incremental oil recovery (>75% ROIP) with low surfactant retention in shorter SP slug injection in reservoir core.
Study of Casing Shielding Effect for Rotating Magnet Ranging in Non-Conventional Decommissioning Applications with Partial Access to a Target Well
Authors: Dorey Jamie , Ridgway Douglas
Published: October 2022

Regardless of their complexity, all wells must be properly plugged and abandoned at the end of their lifecycle to ensure a permanent seal between hydrocarbon-bearing layers, fresh-water zones, and the surface. In most cases, such a seal can be established via conventional well intervention where complete access to the target well is available.

Complex plug and abandonment techniques using access-independent magnetic ranging methods for subsurface well intervention are available for scenarios without access to the target well.

In some cases, the access to a target well may be available from the surface but restricted deeper down the well due to completion specifics, multi-wellbore structure, or well damage. In these cases, access-dependent magnetic ranging, such as the rotating magnet method, can be used to locate and follow the target well until the access restriction before employing access-independent techniques. This approach may significantly reduce the time and capital spending required for well abandonment.

This paper discusses the rotating magnet ranging method in application to the abandonment of wells with partial access. In these scenarios, magnetic ranging sensors are deployed in one or more concentric casing strings that cause a magnetic shielding effect and must be accounted for. The nature of this effect, its interference with the ranging measurements and correction techniques will be described.

A series of surface tests have been performed with the ranging sensor assembly placed within one, two, and three concentric casing strings to study the casing shielding effect on magnetic ranging measurements. The measurements were collected at different relative orientations and distances between the sensors and the signal source, simulating various downhole scenarios.

The results show that triple concentric casing reduces the cross-axis signal 30-fold, double casing – 8.5-fold, and single casing – 4-fold. However, even in the worst-case scenario, the signal stays strong enough to still be able to detect the source more than 20m away.

Access-dependent magnetic ranging methods can be employed in subsurface intervention decommissioning scenarios with partial access to the target well. The challenges associated with running magnetic sensors in a casing can be addressed allowing to minimize time and capital expenditures in non-conventional plug and abandonment.
Moving Rig Time Efficiency to Improve Operations, Reduce Non-Productive Time Rig and Emission Co2 Using on Trailer
Authors: Hidayat Teguh Rachman , Hariagung Erwin , Suharto Suharto , Kurniawan Fajar , Rosandi Didi , Riswandana Reza , Hidayat Rahmat Taufik , Irawan Gondo , Setiadhi Imam , Almadani Nadir Faisal
Published: October 2022

One of the efforts achieve Key Performance Indicator is to realize efficient organizational performance. Optimizing rig movement management is needed in PT. Pertamina Hulu Indonesia Sangasanga Field by reducing the duration of moving between wells and ensuring that the Rig cycle time kept to minimum. In real condition, all equipment in rig unit is still arranged on its own Skid with a large number of transport loads and in the activity of moving Rig/Hoist equipment between wells, all equipment transported is moved and rearranged at the next well location by using Winch Truck, Truck Crane, Flatbed truck and Crane. Moving activities with Winch Trucks and Truck Cranes accompanied by lifting activities have a high risk with 14 loading loads per moving rig. With far distance between sub working area and various obstacles such as river, bridge load limit, land and river transportation types resulting in long rig moving time. In 2019, to the second semester 2020 the loss when moving rigs reached USD 1,483 Million. The limited number of lifting and transporting equipment, the number of equipment and the loading-unloading process are the dominant cause for long moving rig time. To solve this problem, we modify the rig equipment into an On Trailer with the aim to arrange all Rig operational support equipment on the trailer both during operation and moving, and to reduce the number of loads, rig moving time and the risk of lifting. On Trailer is equipped with Handrail & walkway, sets of manual jacks, and trailer and prime mover connection including pneumatic line system. After the implementation of On Trailer, the frequency of loading, unloading and setting work drops to 9 times lower so the potential for tool damage decreases, moving rig time managed to decrease to 9.6 hours thus decrease rig personnel workload. By using On Trailer, it successfully reached cost efficiency of USD 1,354/well, the risk of work accidents due to lifting & rigging activities minimized to 9 times and reduce the CO2 emission is 2,487 Gj/year due to decrease of fossil fuel consumption.
Evaluation of Zonal Isolation Material for Low Temperature Shallow Gas Zone Application
Authors: Agista Madhan Nur , Khalifeh Mahmoud , Saasen Arild
Published: October 2022

Methane gas leaks from shallow gas zone have been reported in some areas in the North Sea. In the North Sea, shallow gas zones can have temperatures below 25°C with relatively low pore pressure. It is necessary to prevent the flow of this gas behind casings by performing proper zonal isolation with cementitious materials. A series of experiments were performed on three different types of industrially used and state-of-the-art cementitious materials and a rock-based geopolymer to evaluate their performance for shallow gas zonal isolation. Neat class G Portland cement, industrial rapid-hardening cement, gas-tight cement, and granite-based geopolymer were the selected materials. The research aims to reveal the performance of these zonal isolation materials and their potential shortcomings due to the low-temperature effect. Material characterizations were performed on three states of the materials: liquid-state, gel phase, and solid-state. Rheological properties and consistency are evaluated at the liquid state of the materials. Static gel strength tests were performed to evaluate the strength of gel structure and transition time. The compressive strength of samples was evaluated using an ultrasonic cement analyzer (UCA) and unconfined compressive strength (UCS). In addition, the scanning electron microscopy (SEM) technique was utilized to reveal microstructure of the materials. To have a similar hydration process as in the low-temperature shallow gas zone, slurries were mixed and pre-conditioned at temperatures of 4 and 25°C. The experiment shows that the hydration process of the cement is less optimum in the low-temperature condition, which affects the gel strength development of the cement during the transition from liquid to a solid phase. It also resulted in the lower final compressive strength of the cured specimens.
Correcting for Base Oil Contamination in Gas Condensate PVT Samples – An Improved Approach
Authors: Bon Jan , Ortega Alexander Jesus , Nalepa Wojciech , Do Giang Thanh Thi , Apolloni Rodmy Gerardo
Published: October 2022

PVT samples collected by wireline formation testers in wells drilled with Oil Based Mud or Synthetic Based Mud (OBM/SBM) can suffer from contamination due to the base oil in the drilling fluid. This is particularly a problem for lean gas condensate reservoir fluids. This study focused on improving decontaminated compositions by adjusting the subtraction factor for each OBM/SBM component.

To demonstrate the concept, a series of static condition laboratory PVT tests were performed using methane only and methane plus CO2 together with an SBM to determine what quantity of each component from the SBM vaporizes into the synthetic reservoir fluid. This was done by adding an excess volume of SBM to a PVT cell with pure methane and establishing equilibrium in order to saturate the fluid at reservoir sampling conditions, and then repeating with addition of 10 mol% CO2 to the gas stream. The subsequent composition was then analyzed to determine what quantity of each component from the base oil vaporized into the reservoir fluid.

Correction methods exist for compositional analyses that involve mathematical subtraction of the base oil contamination from measured compositions. These are spreadsheet exercises, since physically cleaning the samples any more than that achieved already during the sampling process itself is not possible. These correction methods assume either a logarithmic1 or gamma2 distribution to correct the C7+ fraction of the reservoir fluid.

During this process it is often noted that the OBM components do not vaporize equally into the reservoir fluid. We demonstrate through analyses that lighter hydrocarbon components from the OBM/SBM vaporize more easily than heavier components, and that the relationship correlates to the molecular weight of the OBM/SBM component. A linear subtraction process can therefore be improved with a volatility adjustment to each component, which we demonstrate is a function of the equilibrium ratio (K-value). Nagarajan et al. (2010)3 has previously suggested a K-value based correction method, however the novel approach outlined here is the calculation of the quantities in which base oil components will vaporize, giving a ‘pseudo vapor composition’ of the base oil, and using this stream as the first step in the subtraction process.
Fines Migration and Production in CSG Reservoirs: Laboratory & Modelling Study
Authors: Hashemi Abolfazl , Borazjani Sara , Nguyen Cuong , Loi Grace , Badalyan Alexander , Dang-Le Bryant , Bedrikovetsky Pavel
Published: October 2022

Fines detachment is an important component of methane production from Coal Bed Methane reservoirs. Production of coal fines is widely observed during dewatering and simultaneous gas-water production. The theory for fines detachment by drag against electrostatic attraction, model of the transport of those detrital fines, and their validation by laboratory test is widely used for planning and design of Coal Seam Gas developments. However, clay particles that naturally grow on coal grains and asperous parts of coal surfaces (authigenic and potential coal fines) are detached by breakage. To the best of our knowledge, the analytical theory for detachment of authigenic and potential coal fines is not available. The present paper fills the gap. Based on Timoshenko's beam theory, we derive failure conditions for breakage of authigenic and potential coal fines of the rock surface. It allows defining maximum retention function for fines breakage. The maximum retention is incorporated into transport equation of mobilized fines, allowing developing analytical models for linear flow of core flooding and radial flow of well inflow performance. Matching of laboratory coreflood data from four laboratory studies show high agreement. The model coefficients obtained by treatment of laboratory data allow predicting skin growth in production wells under fines migration.
Analytical and Numerical Sand Production Prediction Calibrated with Field Data, Example from High-Rate Gas Wells
Authors: Asadi Sadegh , Khaksar Abbas
Published: October 2022

Sand production prediction is essential from the early stages of field development planning for well completion design and later for production management. Unconsolidated and weakly consolidated sandstones are prone to fail at low flowing bottom hole pressures during hydrocarbon production. To predict the sand-free drawdown, a robust sand prediction model that integrates near-wellbore and in-situ stresses, rock mechanical properties, well trajectory, reservoir pressure, production and depletion trends is required. Sanding prediction models should be calibrated with field data such as production and well tests observation. In the absence of field data, numerical techniques can provide a reliable estimate on potential onset and severity of sanding at various reservoir pressures.

In this study, analytical and finite-element numerical models are independently used to predict the onset of sanding and volume of produced sand from high rate has wells with weakly consolidated sandstone reservoirs in onshore, Western Australia. The analytical method uses a poro-elastic model and core-calibrated log-derived rock strength profiles with an empirical effective rock strength factor (ESF). In the study, the ESF was calibrated against documented field sanding observation from a well test extended flow period at the initial reservoir pressure under a low drawdown pressure. The numerical method uses a poro-elasto-plastic model defined from triaxial core tests. The rock failure criterion in the numerical method is based on a critical strain limit (CSL) corresponding to the failure of the inner wall of thick-walled cylinder core tests that can also satisfy the existing wells sanding observations. To verify the onset and severity of sanding predicted by the analytical model, numerical simulations for an identical sandstone interval are developed to investigate the corresponding CSL.

This combined analytical and numerical modelling calibrated with field data provided high confidence in the sanding evaluation and their application for future well completion and sand management decisions. The analytical model was finally used for sanding assessment over field life pressure condition because of its processing simplicity, speed and flexibility in assessing various pressure and rock strength scenarios with sensitivity analysis over the whole production interval in compared with the numerical method which is more suitable for single-depth, single pressure condition and well and perforation trajectory modelling.
Stiff String Casing Design with 3D Orientated Casing Wear
Authors: Nobbs Benjamin , Aichinger Florian
Published: October 2022

The forces and stresses along a casing string are modelled using a stiff string torque and drag model. A post analysis of casing loads and stresses, considering wellbore tortuosity and centralisation is performed in addition to the effect of 3D orientated casing wear. A post analysis case study is presented to show the resulting effect on axial, burst, collapse and VME safety factor as well as VME body and connection design envelopes.

While running in hole (RIH) a tubular, the industry standard is to assume a smooth wellbore when performing a torque and drag calculation. The drilling process can cause significant local doglegs and ultimately increase the tortuosity of the wellbore. When applying a soft-string torque and drag model, it is possible that the stiffness, radial clearance, and high frequency surveys are not directly considered. The stiff string torque and drag and buckling model can model these effects, as well as the addition of rigid and flexible centralisers. This study involves the comparison of different casing design load cases, using the actual tortuosity of a drilled wellbore considering a 3D orientated casing wear.

The results show that there can be noticeable differences in overall axial stress with the addition of tortuosity. The stiff string model can directly calculate the additional bending stresses experienced by the tubular and this additional stress can be particularly prevalent while RIH casing with centralisers and high tortuosity. The reduction in API and VME stress envelope is also quantified using a 3D orientated casing wear model. A better understanding of axial stress state reduces risk of well integrity issues and can pinpoint areas along the casing in which special care must be taken during well intervention.

This paper will show the benefits of using a stiff string torque and drag model during casing design. Highly tortuous wellbores, especially ERD and HPHT wells, may exhibit stresses that are vastly different than assumed during preplanning phase. The design API/VME envelope may also be reduced due to casing wear.
Effects of mini-clinical evaluation exercise (Mini-CEX) on training the community outpatient medical interviewing ability among general medicine resident physicians
Authors: wang yuanmei , Wang Zhihong , Zou Wusong , Wang Shiqi , Jiang Fan , Li Haiyan
Published: October 2022

Background: To evaluate the effects of mini-clinical evaluation exercise (Mini-CEX) on the training of community outpatient medical interviewing ability among general medicine resident physicians.
Methods: Eighty general medicine resident physicians rotating at the Changqing Garden Community Health Service Center in Wuhan Fourth Hospital were recruited as study participants. The participants were randomized into an experimental group and a control group, with 40 participants per group. Both groups received the same 20 training sessions. However, the experimental group received Mini-CEX evaluation and feedback regarding their community outpatient medical interviewing ability after 10 training sessions. After 20 training sessions, community outpatient medical interviewing ability was evaluated in both groups.
Results: The outpatient medical interviewing ability score of the experimental group was higher than that of the control group (P<0.05). Stratified analysis based on cohort was performed, and the scores of the year 1 and year 3 cohorts in the experimental group were higher than in the control group (P<0.05). A questionnaire survey was carried out on all participants, and 87.5% were supportive of addition of Mini-CEX in the course.
Conclusions: Mini-CEX evaluation in standardized residents training can improve their medical interviewing ability. Residents were receptive of this teaching model.
COVID-19 immunity after vaccination in the population of the Portuguese province Beira Baixa
Authors: Ribeiro Ines , Santos Adriana , Martins Manuel , Liberal Joana , Coelho Patricia , Gavinhos Catarina , Carrondo Cristina , Rodrigues Francisco
Published: October 2022

Introduction

The high emergency in the control of the pandemic has determined that the scientific community is dedicated to the production of effective vaccines for immunization against SARS-CoV-2. With the emergence of new variants of SARS-CoV-2, there was a need to increase immunity in the vaccinated population through a booster dose. The booster dose is allowed to increase the immunity of individuals and, consequently, reduce the probability of reinfection, as well as severe symptoms associated with COVID-19.

Objective

To evaluate the acquired immunity to COVID-19 through vaccination, and to verify the influence of the booster dose on the antibody’s concentration.

Materials and Methods

Data were collected from 965 individuals of both genders and vaccinated for COVID-19.

Results

91.8% of the sample had neutralizing antibodies against SARS-CoV-2, and the group of fully vaccinated individuals had a higher percentage of neutralized antibodies compared to individuals who did not have a booster dose (53.2% vs. 38 .7%).

Discussion

Neutralizing antibodies were found in 91.8% of the sample, which demonstrates the effectiveness of vaccination in the production of antibodies. The results demonstrated the effectiveness of the booster dose in the production of neutralizing antibodies against SARS-CoV-2.

Conclusion

Vaccination was quite effective in producing neutralizing antibodies. In addition, booster vaccination increased humoral immunity.
UDE-based adaptive dynamic surface control for attitude-constrained reusable launch vehicle
Authors: Mo Ran , Li Wenting , Su Shanwei
Published: October 2022

This paper presents an adaptive dynamic surface control (DSC) scheme for vertical takeoff and landing reusable launch vehicles (VTLVs) with unknown disturbances, model uncertainties, and an attitude constraint to achieve exact attitude tracking control in the aerodynamic descent phase. First, the six degree-of-freedom dynamic model of the VTLV is established. Next, the unknown disturbances and mod

el uncertainties in the VTLV model are considered as the total disturbances, which are estimated by employing an uncertainty and disturbance estimator (UDE) to compensate the controller, thereby enhancing the control accuracy of the system. Moreover, a symmetric time-varying barrier Lyapunov function (BLF) is utilized to cope with the attitude-constrained problem. Finally, the high tracking performance of the proposed adaptive dynamic surface controller is verifified by numerical simulation results.
Development and validation of TCM prediction model of diabetic peripheral neuropathy among type 2 diabetes mellitus population in Tianjin, China
Authors: Tian Zhikui , Fan Yadong , Sun Xuan , Wang Dongjun , Guan Yuanyuan , Zhang Ying , Zhang Zhaohui , Guo Jing , Bu Huaien , Wu Zhongming , Wang Hongwu
Published: October 2022

Aims: To determine the clinical predictors of symptoms of TCM and tongue features in type 2 diabetes mellitus (T2DM) with diabetic peripheral neuropathy (DPN), in further to verify whether these parameters of TCM can be used to develop a clinical model for predicting onset of DPN among T2DM.
Methods: We collect information from a standardized questionnaire. The questionnaire survey was performed on 3590 T2DM, participants were randomly divided the training group (n = 3297) and the validation group (n = 1246). Symptoms of TCM and tongue features had used to evaluate the risk to develop DPN in T2DM. The least absolute shrinkage and selection operator (LASSO) regression analysis method and logistic regression analysis had used to optimize variable selection by running 5-fold cross-validation in the training group. Multi-factor logistic regression analysis was used to establish a predictive model. The nomogram had been developed based on the relevant risk factors. A receiver operating characteristic curve (ROC), calibration plot and decision curve analysis (DCA) were used to assess the model in training group and validation group.
Results: A total of eight predictors were found to be independently associated with the DNP in multivariate logistic regression analyses, namely such as advanced age of grading (OR 1.575, 95% CI 1.236–2.006, p = 0.000), smoke (OR 2.815, 95% CI 2.079–3.811, p = 0.000), insomnia (OR 0.557, 95% CI 0.408–0.761, p = 0.000), sweating (OR 0.535, 95% CI 0.362–0.791, p = 0.002), loose teeth (OR1.713, 95% CI 1.258–2.331, p = 0.001), dry skin (OR1.831, 95% CI 1.303–2.574, p = 0.000), purple tongue (OR 2.278, 95% CI 1.514–3.428, p = 0.000) and dark red tongue (OR 0.139, 95% CI 0.044–0.441, p = 0.001). The model constructed with using these eight predictors exhibited medium discriminative capabilities, with an area under the ROC of 0.727 in the training group and 0.744 in the validation group. The calibration plot is shown that the model possesses satisfactory in goodness-of-fit.
Conclusions: Introducing age of grading, purple tongue and symptoms of TCM into the risk model increased its usefulness for predicting DPN risk in patients with T2DM.
Delay-guaranteed Mobile Augmented Reality Task Offloading in Edge-assisted Environment
Authors: Hao Jia , Gan Jianhou
Published: October 2022

With the introduction of augmented reality (AR) technology into mobile devices, it becomes a trend to develop mobile AR applications in various fields. However, the limited mobile hardware resources, like the CPU frequency, memory capacity, etc., makes it difficult to guarantee the delay of resource-intensive AR applications. In response to this challenge, we propose a mobile AR offloading method under the edge-assisted environment. Firstly, we divide an AR task into multiple consecutive subtasks, and then collect the features of hardware, software, configuration, and runtime environments of edge servers to be offloaded. With the features, we construct an AR subtask Execution delay Prediction Bayesian Network (EPBN) to predict the execution delay of different subtasks on each edge platform. Based on the prediction, we model the AR task offloading as the NP-hard Traveling Salesman Problem (TSP), and then propose a PSO-GA based solution by adopting the heuristic algorithm of Particle Swarm Optimization (PSO) to encode the offloading strategy and using Genetic Algorithm (GA) for particle update. The extensive experiments prove that our proposed method can optimize the AR task offloading strategy with the lowest delay and outperform the other baselines.
An Energy-Dense and High-Power Li-Cl2 Battery by Reversible Interhalogen Bonds
Authors: Li Pei , Li Xinliang , Guo Ying , Chen Ao , Zhang Rong , Hou Yue , Huang Zhaodong , Wang Yanbo , Chen Ze , Zhu Jiaxiong , Zhu Minshen , Zhi Chunyi
Published: October 2022

Anionic redox reactions would achieve a high capacity than typical transition-metal-oxide cathodes, offering a low-cost chemistry to advance the energy storage capability of lithium-ion batteries. Li-Cl2 chemistry using anionic redox reactions of Cl0/−1 shows superior operation voltage (~ 3.8 V) and capacity (756 mAh g− 1). However, a redox-active and reversible chlorine cathode has not been developed in organic electrolytes-based lithium-ion batteries. Chlorine ions bonded by ionic bonding hardly dissolve in organic electrolyte, imposing a thermodynamic barrier for redox reactions. Meanwhile, chlorine gas is easily formed during oxidation. Herein, we report an interhalogen compound, iodine trichloride (ICl3), as the cathode to address these two issues. In-situ and ex-situ spectroscopy data and calculations reveal that reduced Cl− ions are partially dissolved in the electrolyte, and oxidized Cl0 is anchored by forming interhalogen bonds with I. A reversible Li-Cl2 at room temperature is developed, which delivers a specific capacity of 302 mAh g− 1 at 425 mA g− 1, and a 73.8% capacity retention at 1250 mA g− 1. The demonstration of reversible interhalogen bonds enabled rechargeable Li-Cl2 battery opens a new avenue to develop halogen compound cathodes.
Differences in diagnosis in patients with atraumatic knee complaints between general practitioners and orthopedic surgeons: a retrospective cohort study
Authors: Evers Bob J. , Schers Henk J. , Ende Cornelia H. M. , Thurlings Rogier , Koëter Sander
Published: October 2022

Background
knee complaints are one of the most common reasons to consult the general practitioners in the Netherlands and contribute to the increasing burden on general practitioners. A proportion of patients that are referred to orthopedic outpatient clinics are potentially referred unnecessarily. We believe osteoarthritis is not always considered by general practitioners as the cause of atraumatic knee complaints. This may impede early recognition and timely care of osteoarthritis complaints and lead to unnecessary referrals.
Methods
the aim of this study was to compare the frequency of (differential) diagnosis of osteoarthritis mentioned in referral letters of general practitioners with the frequency of osteoarthritis mentioned as orthopedic diagnosis at the outpatient clinic. Therefore we conducted a retrospective cohort study based on data collected from referral letters and the corresponding outpatient clinic reports of patients with atraumatic knee complaints of 45 years or older referred to a regional hospital in Nijmegen, The Netherlands in the period from 1-6-2019 until 1-01-2020.
Results
a total of 292 referral letters were included. In the younger aged patients (45–54 years) osteoarthritis was mentioned less frequent and meniscal lesions were mentioned more frequent in referral letters when compared to diagnoses made at the outpatient clinic. Matching diagnoses were present in 58.2% when all referral letters were analyzed and 75.2% when only referrals containing a (differential) diagnosis were analyzed (n = 226). Matching diagnoses were present in 21.4% in the younger age categories (45–54 years).
Conclusions
Osteoarthritis was less frequently mentioned in general practitioner referral letters among the differential diagnosis then it was diagnosed at the outpatient clinic, especially in younger patients (45–54 years). Also matching diagnoses in younger patients were evidently lower than in older patients, possibly explained by underdiagnosing of osteoarthritis in younger patients in this cohort. Better recognition of osteoarthritis in younger patients and changing the diagnostic approach of general practitioners might improve efficacy in knee care. Future research should focus on the effectiveness of musculoskeletal triage, the need for multidisciplinary educational programs for patients and promotion of conservative treatment modalities among general practitioners.
A critical appraisal on antibody detector-serodiagnostics for Bovine Tuberculosis
Authors: Soliman Rafik , Waheeb Neven , Nasr Essam , El-hariri Mahmoud , Abo-Elyazeed Heidy , Aboul-Ella Hassan
Published: October 2022

Bovine tuberculosis is a worldwide disease that causes great economic losses to the dairy industry and constitutes a serious human public health hazard. In the present study, two types of commercially available immunochromatographic lateral flow kits, namely, IQRT Anigen Rapid Bovine TB Ab kit and Ubio quick VET Bovine Tuberculosis Antibody kit were evaluated for their sero-diagnostic sensitivity and specificity of bovine tuberculosis through the detection of Mycobacterium bovis-specific antibodies in tested serum samples. The results obtained by these kits were compared with the ELISA test, bacteriological examination, and tuberculin skin testing. In this study, out of 3750 dairy cattle tested by single intradermal tuberculin skin test, 69 (1.8%) animals reacted positively. From the slaughtered tuberculin-positive cattle 51 animals (73.9%) showed visible lesions on postmortem examination while the remaining 18 animals (26.1%) showed no visible lesions. Using bacteriological examination of tissue specimens collected, 48 out of the 69 positive tuberculin reactor animals (69.6%) were positive and M. bovis was successfully isolated. Using ELISA for serological examination of serum samples collected prior to skin testing from the 69 positive tuberculin reactors, only 26 cases (37.7%) were positive. The serodiagnosis of bovine tuberculosis using the IQRT Anigen lateral flow kit, which employed recombinant M. bovis MPB70 antigen as capture and detector, could identify only 21 positive cases, which represent 43.8% of 48 bacteriologically identified cases and 30.44% out of the 69 tuberculin positive cases. On the other hand, the Ubio quick VET kit has detected zero% of bovine tuberculosis-positive cattle. It is concluded that the use bovine tuberculosis Antibody Rapid Test Kit alone may be unreliable for the detection of tuberculosis-infected cattle.
Life Cycle Assessment of Sugar Production in Sudan: Green-House Gases Emissions and Energy Usage
Authors: Ibrahim Tageldeen Saeed Tageldeen , Workneh Tilahun Seyoum
Published: October 2022

A Life Cycle Assessment used to analyse the Sudanese sugar production environmental impact. The systems studied include sugarcane production, fertilizers, and herbicides manufacturing, sugarcane harvesting and transportation, and sugar milling. The study used SimaPro Software Version 9.0.0.49 and the methods of ReCiPe 2016 and Intergovernmental Panel for Climate Change (IPCC) 2007. Sugarcane production was the most consumer (39%) of fossil fuel (2166 MJ t− 1 sugar), followed by sugar processing (26.6%), sugarcane cultivation (20.7%) and sugarcane harvesting with transportation (13.7%). The green-house gases emissions were 271.2 kg CO2-equivalent t− 1 sugar and 59% of this is from sugarcane production. However, 51% of the global warming potential was from sugar processing, sugarcane production. The principal contributor to ozone depletion was sugarcane production (44%). Sugar processing has contributed significantly to eutrophication, acidification, particulate matter, and ecotoxicity. The study has recommended enhancement on the sugar industry operations that would substantially improve environmental performance.
The Technological Barrier in the World of Disability: The Wall to Tear Down
Authors: Kerras Hayet , Bautista Susana , Perea Danilo Santos Piñeros , De-Miguel María Dolores
Published: October 2022

Digital transformation is a reality that is having a greater impact on the lives of each person. However, its achievement depends on the accessibility and use of Information and Communication Technologies (ICTs), regardless of gender, age, race, geographical area, or disability. People with disabilities and especially women are faced with digital gaps that harm them in their daily lives. The objective of this work is to investigate, through a survey, the perception of this community about their availability and technological skills and to evaluate the contribution of technologies at a personal, professional, educational, and social level. The results of this study show that there is a very visible digital gender gap, especially in terms of the use of technology, which affects the improvement of the lives of people with disabilities. Finally, measures are proposed that allow a change in the current situation to avoid the limitations suffered by these people.
Explainable Machine Learning model reveals its decision-making process in identifying patients with paroxysmal atrial fibrillation at high risk for recurrence after catheter ablation
Authors: Ma Yibo , Zhang Dong , Xu Jian , Pang Huani , Hu Miaoyang , Li Jie , Zhou Shiqiang , Guo Lanyan , Yi Fu
Published: October 2022

Background
A number of models have been reported for predicting atrial fibrillation (AF) recurrence after catheter ablation. Although many machine learning (ML) models were developed among them, black-box effect existed widely. It was always difficult to explain how variables affect model output. We sought to implement an explainable ML model and then reveal its decision-making process in identifying patients with paroxysmal AF at high risk for recurrence after catheter ablation.
Methods
Between January 2018 and December 2020, 471 consecutive patients with paroxysmal AF who had their first catheter ablation procedure were retrospectively enrolled. Patients were randomly assigned into training cohort (70%) and testing cohort (30%). The explainable ML model based on Random Forest (RF) algorithm was developed and modified on training cohort, and tested on testing cohort. In order to gain insight into the association between observed values and model output, Shapley additive explanations (SHAP) analysis was used to visualize the ML model.
Results
In this cohort, 135 patients (14.2/100 patient-years) experienced tachycardias recurrence. With hyperparameters adjusted, the ML model predicted AF recurrence with an area under the curve (AUC) of 66.7% in the testing cohort. Based on SHAP analysis, the ML model's decision-making process was revealed: (i) summary plot listed the top 15 features in descending order and preliminary showed the association between features and outcome prediction; (ii) dependence plots combined with force plots showed the impact of single feature on model output, and helped determine high risk cut-off points; (iii) decision plot recognized significant outliers.
Conclusion
An explainable ML model effectively revealed its decision-making process in identifying patients with paroxysmal atrial fibrillation at high risk for recurrence after catheter ablation. Physicians can combine model output, visualization of model and clinical experience to make better decision.
Are pristine and functionalized fullerenes genuine constituents of airborne aerosols?
Authors: Santos Fábio N. dos , Nascimento Madson M. , Rocha Gisele , de Andrade Jailson
Published: October 2022

We investigated if pristine and functionalized fullerenes could be actual constituents of fine atmospheric aerosols. Comprehensive profiles of fullerenes from 1 µL extracts were made through matrix laser desorption ionization Time-of-Flight Mass Spectrometry (MALDI-MS) within a few minutes. Using 1 µL of α-cyano-4-hydroxycinnamic acid matrix solution spotted over the dried extracts, the ion with m/z 720, corresponding to [C60]-•, was identified as fullerene. The ions with the m/z corresponding to C70, C76, C78, C84, C100, C118, C128, and C130 were also attributed to other fullerene species detected within the samples. The fullerene derivative diethyl methano[60]fullerene dicarboxylate was observed as the ion m/z 878. Since ions of fragmented fullerene molecules were not detected even at high laser energies, we considered the fullerenes’ occurring as original constituents of real atmospheric particle matrices instead of being formed as artifacts of the laser action on samples. Therefore, this protocol would be helpful in the understanding of the distribution of either pristine or functionalized fullerenes in the environment and their participation in atmospheric chemistry under typical conditions, as well as to be applied in vitro and in vivo (eco)toxicity studies.
The Rna-binding Protein Fus/tls Interacts With Spo11 and Provides a Link With Prdm9-dependent Recombination Hotspots
Authors: Giannattasio Teresa , Testa Erika , Palombo Ramona , Chellini Lidia , Crevenna Álvaro , Petkov Petko , Paronetto Maria Paola , Barchi Marco
Published: October 2022

In mammals, meiotic recombination is initiated by the introduction of DNA double strand breaks (DSBs) into narrow segments of the genome, defined as hotspots, which is carried out by the SPO11/TOPOVIBL complex. A major player in hotspots specification is PRDM9, a histone methyltransferase that following sequence-specific DNA binding generates trimethylation on lysine 4 (H3K4me3) and lysine 36 (H3K36me3) of histone H3, thus defining the hotspots. PRDM9 activity is key to successful meiosis, as in its absence DSBs are redirected to functional sites, and synapsis between homologous chromosomes fails. One protein factor recently implicated in guiding PRDM9 activity at hotspots is EWS, a member of the FET family of proteins that also includes TAF15 and FUS/TLS. Here, we demonstrate that FUS/TLS partially co-localizes with PRDM9 on meiotic chromosome axes, marked by the synaptonemal complex component SYCP3, and physically interacts with PRDM9. Furthermore, we show that FUS/TLS also interacts with REC114, one of the axis-bound SPO11-auxiliary factors essential for DSBs formation. This finding suggests FUS/TLS as a component of the protein complex that promotes meiotic recombination initiation. Accordingly, we document that FUS/TLS co-immunoprecipitates with SPO11 in vitro and in vivo. The interaction occurs with both Spo11β and Spo11α splice isoforms, which are thought to play distinct functions in DSB formation onto autosomes and male sex chromosomes, respectively. Finally, by using chromatin immunoprecipitation experiments, we show that FUS/TLS localizes at H3K4me3-marked hotspots onto autosomes and in the pseudo autosomal region, the site of genetic exchange between the XY chromosomes.
Gender Gaps and Family Policies in Latin America
Authors: Galván Estefanía , Parada Cecilia , Querejeta Martina , Salvador Soledad
Published: October 2022

Gender equality in the labor market remains a difficult challenge in Latin America and recent literature shows that child penalties play an important role in explaining these gaps. While policies to address gaps related to parenthood were introduced in recent decades, evidence of its effects is still scarce. This paper presents comparable evidence on the adoption of family legislation in 15 Latin American countries and discusses its relationship with the evolution of the gender gaps in the labor market and the prevailing gender norms. We document that from 2000 to 2019 almost all countries increased the weeks covered by maternity, paternity, or parental leaves. Following a similar approach to that of Olivetti and Petrongolo (2017), we exploit the variations over time and control for country and year-fixed effects to study the relationship between the extension of family leaves and women's outcomes. We find that these policies are successful in increasing female employment and reducing employment gaps in countries departing from a worse situation in terms of leave coverage or with more traditional perceptions of gender roles. On the other hand, for countries which have more egalitarian gender perceptions, our results suggest that the extension of family leaves contributes to reduce the income gaps.