bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Study of Cuttings Transport with Non-Newtonian Fluid in an Inclined Well Using Visualization and Electrical Resistance Tomography Techniques
Authors: Huque Mohammad Mojammel , Imtiaz Syed , Zendehboudi Sohrab , Butt Stephen , Rahman Mohammad Azizur , Maheshwari Priyank 
Published: April 2021

Summary
Hole cleaning is a concern in directional and horizontal well drilling operations where drill cuttings tend to settle in the lower annulus section. Laboratory-scale experiments were performed with different non-Newtonian fluids in a 6.16-m-long, 114.3- × 63.5-mm transparent annulus test section to investigate cuttings transport behavior. This experimental study focused on understanding the cuttings transport mechanism in the annulus section with high-speed imaging technology. The movement of cuttings in the inclined annular section was captured with a high-speed camera at 2,000 frames/sec. Also, cuttings bed movement patterns at different fluid velocities and inner pipe rotations were captured with a digital single-lens reflex video camera. The electrical resistance tomography (ERT) system was used to quantify the cuttings volume fraction in the annulus. Different solid bed heights and cuttings movements were observed based on fluid rheology, fluid velocity, and inner pipe rotation. The mechanistic three-layer cuttings transport model was visualized with the experimental procedure. This study showed that solid bed height is significantly reduced with an increase in the inner pipe rotation. This study also identified that cuttings bed thickness largely depends on fluid rheology and wellbore inclination. The image from the high-speed camera identified a downward trend of some rolling particles in the annulus caused by gravitational force at a low mud velocity. Visual observation from a high-speed camera identified a helical motion of solid particles when the drillpipe is in contact with solid particles and rotating at a higher rev/min. Different cuttings movement patterns such as: rolling, sliding, suspension, helical movement, and downward movement were identified from the visualization of a high-speed camera.
Analyzing dispersion properties of hole and ring like photonic crystal waveguides by introducing systematic shift and twist
Authors: Pavan Vadapalli Durga Rama , Roy Sourabh 
Published: April 2021

Abstract
Dispersion engineering of photonic crystal waveguides is attractive due to their potential applications in linear and nonlinear phenomena. Here, we present a comprehensive and systematic study to achieve the increased control over the dispersion curve of the waveguide, operating at telecom wavelengths. The effect of the radius of air cylinders, and their lattice position on the dispersion features is studied chiefly in a line-defect photonic crystal waveguide. For this purpose, perturbations were introduced in the radius and position of the air cylinders. With the help of MIT Photonic Bands software, group index and dispersion coefficients were calculated to characterize the features of the waveguide. Ring like structures were introduced in the innermost rows to increase the impact to further level. With this systematic study, one can tune the waveguide with desired range of group index and bandwidth with controlled dispersion properties. Present study resulted with the flat group index in the range of 31.42 to 7.64 over a wavelength range of 7.97 nm to 30.41 nm with very low dispersion. The developed structures may find applications in optical delays, optical buffers and nonlinear applications.
Analyzing travel time belief reliability in road network under uncertain random environment
Authors: Yang Yi , Huang Siyu , Wen Meilin , Chen Xiao , Zhang Qingyuan , Liu Wei 
Published: April 2021

Abstract
It is necessary to understand the operation status of the urban road network, especially when the network is complicated and uncertain. Taking travel time data as the starting point, we have studied the shortcomings of existing travel time reliability indicators. Most of them simplify or even ignore the information of traffic performance thresholds. According to the characteristics of the real urban road network, by extracting the information of the subject and object of the traffic service, we proposed measurement of the reliability of travel time in an uncertain random environment, that is, the travel time belief reliability, which takes the impact of the epistemic and random uncertainty on reliability into account. Next, we established the belief reliability model of travel task under the uncertain random road environment. The model considers path selection, departure status and road conditions, and gives a path selection algorithm under time-varying road network. Besides, using the uncertainty regression analysis method, we explored the impact of road objective factors and driving state factors on the travel time threshold. Finally, we took the actual travel task in Beijing as an example to verify the feasibility and practicability of the model and algorithm.
Glutaraldehyde Enhancement by D-limonene for Mitigating Biocorrosion of Carbon Steel by An Oilfield Biofilm Consortium
Authors: Kijkla Pruch , Wang Di , Mohamed Magdy E. , Saleh Mazen A. , Kumseranee Sith , Punpruk Suchada , Gu Tingyue 
Published: April 2021

Abstract
Microbiologically influenced corrosion (MIC) is one of the corrosion threats in the oil and gas industry. It is caused by environmental biofilms. Glutaraldehyde is a popular green biocide for mitigating biofilms and MIC. This work investigated the enhancement of glutaraldehyde efficacy by food-grade green chemical D-limonene in the biofilm prevention and MIC mitigation using an oilfield biofilm consortium. After 7–d incubation at 37oC with enriched artificial seawater (EASW) in 125 mL anaerobic vials, the 100 ppm glutaraldehyde + 200 ppm D-limonene combination treatment reduced the sessile cell counts on C1018 carbon steel coupons by 2.1 − log, 1.7 − log, and 2.3 − log for SRB (sulfate reducing bacteria), APB (acid producing bacteria), and GHB (general heterotrophic bacteria), respectively in comparison with the untreated control. The treatment achieved 68% weight loss reduction and 78% pit depth reduction. The 100 ppm glutaraldehyde + 200 ppm D-limonene combination treatment was found more effective in biofilm prevention and MIC mitigation than glutaraldehyde and D-limonene used individually. Electrochemical tests corroborated weight loss and pit depth data trends.
Mercury Methylation Upon Coastal Sediment Resuspension: A Worst-case Approach Under Dark Conditions
Authors: Monte Christiane , Rodrigues Ana Paula , Galvão Petrus , Pontes Gabriela , Malm Olaf , Wasserman Júlio , Machado Wilson 
Published: April 2021

Abstract
Mercury behavior upon resuspension of sediments from two impacted areas of Guanabara Bay was evaluated to assess worst-case methylmercury (MeHg) responses, under dark experimental conditions. Total mercury (THg) and MeHg concentrations were determined along 24 hours experiments of sediment resuspension in the bay water. Fine-grained Meriti River estuary (MR) sediments had 8-times higher MeHg initial concentrations than sandy Rio the Janeiro Harbor (RJH) sediments (3.4 ± 0.29 vs. 0.41 ± 0.1 ng g− 1, respectively).THg contents were uncorrelated with resuspension time, while correlations of resuspension time with MeHg (r2 = 0.66) and %MeHg in relation to THg (r2 = 0.75) were observed only for RJH sediments. These findings correspond to a 2.8-times MeHg concentration increase (ΔMeHg = 0.75 ng g− 1) and 4.4-times increase in %MeHg (Δ%MeHg = 1.0%) for station RJH.This suggests that assessments of MeHg spatial-temporal variability can be limited if concentration changes due to sediment resuspension are not considered.
Strength Characteristics and Heavy Metal Leaching Behavior of Contaminated Mining Sludge at Extra High Water Content Solidified/Stabilized with Lime Activated GGBS or OPC
Authors: Fatah Traore Abdoul , Zhang Rong-Jun , Huang Xiao-Song , Miao Yu , Mastoi Aamir Khan 
Published: April 2021

Abstract
Sludge management is one of the major challenges in mining activities. The direct disposal of contaminated mining sludge can bring severe damages to the environment and community. Solidification/Stabilization (S/S) is a very efficient technology for the treatment of contaminated mining sludge because it not only improves the stability of sludge dumping sites but also reduces the leachability of contaminants. Very few studies investigate the S/S of mining sludge, especially with extra high water content. This paper investigated the effectiveness of S/S for the treatment of mining sludge at extra high water content by using quick lime (CaO) activated ground granulated blast furnace slag (GGBS) in comparison to ordinary Portland cement (OPC). To evaluate the mechanical, leaching, and microstructural behavior of mining sludge at extra high water content stabilized by lime activated GGBS and OPC, a series of laboratory experiments were performed, including unconfined compressive strength (UCS), toxicity characteristics leaching procedure (TCLP), X-Ray diffraction, and scanning electron microscopy (SEM) tests, etc. Experimental results indicated that increasing the binder content led to increased strength and decreased leachability of the heavy metal. In contrast, an increase in the water content of the mixture resulted in a decrease in compressive strength and an increase in leachability of heavy metals. On the other hand, lime activated GGBS had substantially better performance than OPC in the aspect of strength development of treated mining sludge and moreover showed comparable capability of heavy metal stabilization in contrast to OPC.
Grid based Energy-Efficient Cross-Layer Optimization Model in WSN Using Dual Mobile Sinks
Authors: D Vimala , K Manikandan 
Published: April 2021

Abstract
In recent days, wireless sensor network (WSN) gained more attention among researchers as well as industries. It is composed with massive number of sensors which are independently organized cooperate with one another for collecting, processing and transmitting data to the base station (BS) or sink. Since sensors undergo random deployment in harsh environment, it is difficult or not even possible to replace the batteries. So, energy efficient clustering and routing techniques are preferable to reduce the dissipation of energy and improve the network lifetime. This paper introduces a new Grid based Energy-Efficient Cross-Layer Optimization Model in WSN Using Dual Mobile Sink (GEECLO). The proposed method involves three main processes namely grid partitioning, clustering and routing. Initially, the entire network is partitioned into different zones and then sub zones. Then, type II FL process gets executed to select the CHs and construct the clusters. Finally, dolphin swarm optimization algorithm (DSOA) based routing process takes place to select the optimal path for inter-cluster communication. A detailed simulation analysis takes place to ensure the betterment of the GEECLO algorithm. The obtained experimentation outcome depicted that the GEECLO model offers maximum energy efficiency and network lifetime.
Continuity of Essential Sexual and Reproductive Health Services During Covid-19 Pandemic in the Who African Region
Authors: Otieno George Ochieng , Ouedraogo Leopold , Nkurunziza Triphonie , Asmani Chilanga , Elamin Hayfa , Muriithi Assumpta , Onyiah Pamela Amaka , Conombo Ghislaine , Kidula Nancy , Tall Fatim , Sekpon Ameyo , Adegboyega Ayotunde Adenola 
Published: April 2021

Abstract
Background: The COVID-19 pandemic has had a major impact on the capacity of health systems to continue the delivery of essential health services. While health systems around the world are being challenged by increasing demand for care of COVID-19 patients, it is critical to all other services including sexual reproductive health services. Countries are expected to ensure optimal balance between fighting the COVID-19 pandemic and maintenance of essential health services like sexual reproductive health. The purpose of this report was to assess and document continuity of sexual and reproductive health services with a focus on safe abortion, post abortion care and family planning services during the COVID -19 pandemic in selected countries of the World Health Organization Africa Region.Methods: A descriptive survey using a simplified and user-friendly virtual web based rapid needs assessment through a questionnaire was filled in by key informants drawn from the ministries of health from 30 countries in July 2020. The questionnaires were filled in by the World Health Organization staff in charge of sexual reproductive health services in collaboration with their counterparts in the ministries of health and uploaded in excel data sheets and categorized in to thematic areas for analysis.Results: Responses were received from 17 countries out of the 30 countries that received the questionnaires. Of the 17 countries, only 2 (12%) countries reported that sexual and reproductive health services are not integrated in the essential health services package. All the sexual reproductive health elements-family planning/contraception and comprehensive abortion care, including post abortion care are integrated in the essential health services package in 12 (80%) of the 15 countries that have sexual reproductive health integrated. Also,14(82%) countries reporting having ongoing awareness raising campaigns/communication messages about family planning, comprehensive abortion care and post abortion care during the COVID pandemic. 9(59%) of the countries reported reduction in the use of family planning services, 6(35%) indicated no changes in the use of family planning services with only 2(12%) countries providing no response. Conclusion: The survey provides information on the weak health systems of the participating member states of the WHO Africa Region and the magnitude of disruptions of sexual reproductive health services in selected countries. Further, strategies adopted by countries to ensure continuity of sexual reproductive health services amidst COVID -19 like communications, Countries finally identified key areas that need to be supported in family planning/contraception, comprehensive abortion care and post abortion care during the COVID-19 pandemic.
Adaptive Asymptotic Fault Tolerant Tracking of Uncertain Nonlinear Systems with Unknown Control Directions
Authors: Yang Jinzi , Li Yuan-Xin , Tong Shaocheng 
Published: April 2021

Abstract
In the article, the issues of asymptotic adaptive tracking control for the uncertain nonlinear systems in the presence of actuator faults and unknown control directions are investigated. By using the properties of Nussbaum function and backstepping technique, the problems resulted from the unknown signs of the nonlinear control functions are circumvented successfully. Moreover, a new adaptive asymptotic tracking control method is presented with the fault tolerant control framework, which is capable of realizing zero-tracking performance. The stability of the controlled system is ensured through fractional Lyapunov stability analysis. Finally, the validity of the raised scheme is verified by a simulation example.
Engineering Properties of Sandy soil Improvement with Bacillus Simplex
Authors: Bagriacik Baki , Sani Zahrettin Kabir , Uslu Fatima Masume , Yigittekin Esra Sunduz , Dincer Sadik 
Published: April 2021

Abstract
Purpose: Stabilization of weak soil can be achieved through different methods, some of which include: jet column, cement stabilization and fly ash stabilization. Unfortunately, the use of the aforementioned methods of soil improvement affects the environment negatively thereby leading to environmental degradation. With the aforesaid impediment in mind, the need for devising methods of weak soil improvement becomes pertinent. Methods: Bacillus sp. - a non-pathogenic organism found abundantly in soil - was investigated in this study as a potential agent of soil improvement. The usability of Bacillus sp. in soil improvement was investigated with direct shear tests and permeability tests under optimum conditions in this study.Result: Time-dependent study on the effect of the ureolytic bacteria Bacillus simplex induced calcium carbonate precipitation shows reduction in permeability and increase in the strength of the soil under study. On exhaustion of the available nutrients in the soil however, the strength of the soil is not negatively impacted.Conclusion: Microbially induced calcium precipitation by Bacillus sp. is effective in soil improvement as such it may serve as substitute for conventional soil stabilisation techniques. The ability of the bacteria to precipitate calcium carbonate in the soil leads to reduction in the permeability and increase in the shear strength of the soil.
The impact of the SARS-Cov 2 pandemic on pro-health attitudes, psychophysical condition, and the quality of life of students
Authors: Bogut Bożena , Kuciel-Lewandowska Jadwiga , Kasperczak Michał 
Published: April 2021

Abstract
Background: Young people follow a healthy lifestyle by undertaking various forms of physical activity. The emergence of pandemics and changes in the organization of society’s life have caused fear and anxiety about health and life. The objective of the study was the assessment of the impact of the SARS-COV-2 pandemic on pro-health attitudes, psychophysical condition, and quality of life of students. Methods: The study included 150 students aged 22 attending Polish Universities. The study utilized the original questionnaire. The questionnaire included questions about mental state, quality, and frequency of meals, hours of sleep, need for physical activity, and the impact of these factors on the quality of life during the pandemic. Results: The pandemic and the closure of sports venues didn’t significantly decrease the quality of life in the study group. Many students used their free time spent at home to sleep, eat healthily, and became interested in various forms of physical activity, which positively influenced their quality of life. Conclusions: The pandemic and associated restrictions haven’t had an impact on the psychophysical condition of the students and weren’t the cause of the abandonment of physical activity. Positive changes in the students’ quality of life were observed.
Predictive physico-chemical model for soil quality index in a long-term green manure farming system at tropical conditions, North-eastern Brazil
Authors: Nascimento Gislaine dos Santos , Souza Tancredo , Silva Lucas Jónatan Rodrigues da , Laurindo Lídia Klestadt , Santos Djail 
Published: April 2021

Abstract
Soil quality index shed light on soil health and its capacity to sustain high primary production. It also can assist decision-making in farming systems by integrating this valuable product into soil management planning. However, the currently existing models are based on rather local data, and thus, there is a lack of predictive tools to monitor soil quality on farming systems at tropical conditions. We characterized soil physico-chemical properties, plant biomass production under a 6-year experiment in a sandy soil from Tropical ecosystem, using ten treatments: Brachiaria decumbens, Canavalia ensiformis, Crotalaria juncea, Crotalaria ochroleuca, Crotalaria spectabilis, Lablab purpureus, Mucuna pruriens, Neonotonia wightii, Pennisetum glaucum, and Stilozobium aterrimum. We found that most of the soil physico-chemical properties were correlated with each other by Pearson’s correlation analysis. On the other hand, RDA illustrated that shoot dry biomass was related to soil C stock, K+, macro- and microporosity. Soil pH, Al3+, Ca2+, Mg2+, K+, Olsen’s P, Na+, soil C stock, bulk density, microporosity, macroporosity, and permanent wilting point were the main factors driving primary production in our long-term study. Our findings suggest that: 1) a consecutive green manure practice without any input of fertilizers after 6 years changed positively by increasing soil fertility (e.g., Ca2+, Mg2+, K+ and Olsen’s P), and improving plant growth and soil quality in tropical savanna climate conditions; and 2) the 33 multivariate predictive models may provide a deeper view about the benefits of using plant species as green manure by creating positive plant-soil feedback thus promoting soil quality.
Developing a Single-Item General Self-Efficacy Scale: An Initial Study
Authors: Di Weiwei , Nie Youyan , Chua Bee Leng , Chye Stefanie , Teo Timothy 
Published: April 2021

Abstract
Purpose General self-efficacy represents a global sense of personal capability across various situations and tasks. The aims of present study were to develop and validate a single-item general self-efficacy scale which balances the practical demands and psychometric concerns. Methods The psychometric properties of the proposed Single-Item General Self-Efficacy Scale (GSE-SI) was examined among 231 Singaporean adults. GSE-SI was selected through experts and four statistical methods. Besides, the reliability, criterion-related, construct-related validity and discriminative power of GSE-SI were examined. Results Three reliability tests demonstrated a good reliability of GSE-SI (.594 .607 and .726, respectively, M = .642), comparing with other single item scales. It also showed a satisfactory criterion-related validity (i.e. correlation with a multiple-item general self-efficacy scale, r = .795). The construct-related validity was supported by the correlations between general self-efficacy and six relevant constructs (i.e. positive correlations with life satisfaction and positive emotions, negative correlations with negative emotions, task and perceived stress and illness symptoms). Importantly, GSE-SI and multiple-item scale showed consistent correlation patterns with relevant constructs. GSE-SI also performed similar discriminations across three respondent clusters divided based on six constructs, in accordance with the multiple-item scale. Conclusions GSE-SI is a reliable and valid measurement of general self-efficacy and could be recommended in future research.
Assessing Agri-Environmental Indicators and Pollution Impacts on Environmental Performance Index and Agri-Economic Indicators in EU and ME countries: A Bayesian Network Based Model
Authors: Firoozzare Ali , Naghavi somayeh 
Published: April 2021

Abstract
Agricultural sector has a key role in relation to poverty reduction and improving food security.One of important challenges in the agriculture sector is to feed population that is increasing in the world. Agriculture has significant and negative impacts on the environment and earth ecosystems.The agricultural sector growth has made pollution and pollution has restricted increasing production in agricultural. Climate change has led researchers to pay close attention to environmental performance. Bayesian networks are relatively well recognized to be an advantageous method for different types of environmental model. This study was designed a Bayesian network model to investigate the relation between agri-economic-environmental indicators and Environmental performance Index in the EU countries compared to Middle East countries, in 2018. we showed relations between variables of model based on expert interview and previous researches. The results indicated land productivity is directly affected by node Agriculture area certified organic.We predicted with developing Agriculture area certified organic and conservation agricultural area, and productivity can be increased in EU Countries. Also, our findings showed with decreasing N2O and CH4 emissions indicators, increased Enivironmental performance index in EU countries and decreasesd in Middle East countries.Terefore, EU countries is improved agricultural practices and pesticides and fertilizer, But ME countries have not been successful in improving the environmental performance index and sustainable development objectives. Modelling of agri-environmental indicators can help to policymakers about the changes of agro-ecosystem and can use for international reviews.