bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Estimation of Carbon Dioxide Stored in CO2 EOR Operations for Screening Purposes
Authors: Carlino Andrea , Muggeridge Ann Helen , Smalley Philip Craig
Published: April 2022

We describe the development, testing, and first application of a rapid method for estimating the CO2 storage potential associated with CO2 enhanced oil recovery in both secondary and tertiary modes. The new method builds on various published empirical models for predicting incremental oil recovery (and hence CO2 storage) in solvent floods. It improves the representation of reservoir heterogeneity caused by depositional layering and fracturing. This is then combined with material balance to make site-specific estimates of the CO2 storage potential.

We cross-checked predictions from the new method against historical field data for major onshore CO2 floods with satisfactory results considering the very approximate nature of the estimation. We then applied the method to a selection of offshore oil reservoirs and found that, generally, the larger the remaining oil, which is a function of initial size and current recovery factor, the greater the CO2 storage potential. We also modelled the case of continued injection after ceasing oil production at, or after, CO2 breakthrough and observed that, as expected, the amount of CO2 stored at breakthrough depends on how early this occurs, which is affected by reservoir heterogeneity, whereas continued injection is limited by the headroom between current reservoir pressure and fracture pressure. The overall storage is the result of the interplay between these two mechanisms. In the studied fields/reservoirs, we demonstrated that large amounts of CO2 can be stored in terms of absolute mass and that storage of these quantities would represent significant abatement of the emissions generated by burning the incremental oil.

The new method can be used as a screening tool to identify and rank candidate oil fields for combined CO2 enhanced oil recovery and storage in regional, national, or corporate portfolios.
Novel Application of Polyethylene Oxide Polymer for EOR from Oil-Wet Carbonates
Authors: Trine Eric Brandon , Pope Gary Arnold , Britton Chris James , Dean Robert Matthew , Driver Jonathan William
Published: April 2022

The objective of this study was to test the performance of high-molecular weight polyethylene oxide (PEO) polymer in a low-permeability, oil-wet carbonate reservoir rock. Conventional HPAM polymers of similar molecular weight did not exhibit acceptable transport in the same rock, so PEO was explored as an alternative polymer. Viscosity, pressure drop across each section of the core, oil recovery, and polymer retention were measured. The PEO polymer showed good transport in the 23 mD reservoir carbonate core and reduced the residual saturation from 0.29 to 0.17. The reduction of residual oil saturation after polymer flooding using PEO was unexpected and potentially significant.
Methods to Improve Accuracy and Performance in a Fully Implicit Surfactant Flood Simulator
Authors: Shi Xundan , Han Choongyong , Wolfsteiner Christian , Chang Yih-Bor , Güyagüler Baris
Published: April 2022

Saturation distributions exhibiting unphysical "checkerboard" patterns, time-step size sensitivity, and slow convergence in certain instances are observed in a fully implicit surfactant simulator that is based on an industry-wide accepted formulation. In this paper, we discuss methods to address each of the above conditions and hereby achieve a robust algorithm with favorable convergence characteristics.

The proposed remedies are result of in-depth studies of the physics of micro-emulsion appearance and disappearance as well as detailed analysis of the numerical convergence difficulty. Our method considers wide ranges of solution variables in a typical surfactant flood simulator and critical key parameters identified by flash algorithm [Han, et al. 2017] and general non-linear solver. The details of the improved formulation are provided and should enable readers to replicate all these results.

Identifying grid cells in a reservoir model where and when the micro-emulsion phase appears is a key capability in the modeling of surfactant phase behavior. The Critical Micelle Concentration (CMC) is the commonly accepted triggering criterion for forming the micro-emulsion phase. We have observed unphysical "checkerboard" saturation patterns for several cases where water mobility is greater than oil mobility when using the conventionally accepted CMC calculation method. We have analyzed the reasons for this unphysical solution and propose a new CMC definition to ensure physically consistent simulation results. Typical CMC values for surfactant flood are in the range of 10-5 to 10-3. This requires surfactant concentration to be solved more accurately relative to other component concentrations as it directly affects micro-emulsion phase disappearance. The simulation results may vary with time-step sizes not only from the time-truncation errors but, more importantly, from the accuracy of the solved surfactant concentration for each time-step. Special treatments are introduced to reduce the time-step size sensitivity in our simulator. For cases with cation exchange, slow convergence is observed as the corresponding governing equations form an ill-conditioned matrix for cells with small surfactant concentration. An extra term is introduced into the formulation to speed up the convergence rate without changing the model behavior.
Revised Correlation for Accurate Estimation of CO2-Brine Interfacial Tension at Reservoir Conditions
Authors: Jerauld Gary Russell , Kazemi Nia Korrani Aboulghasem
Published: April 2022

A recently reported correlation of CO2−brine interfacial tension (IFT) for the full range of reservoir pressure, temperature, and formation water salinity necessary to evaluate CO2 sequestration in hydrocarbon reservoirs has been revised and simplified. The new CO2−brine correlation predicts CO2−brine IFT normalized by water surface tension from temperature, CO2-water density difference normalized by the density difference between water and it's vapor(function of pressure and temperature), and the valence-weighted molality of the cations. The correlation was derived from a database that covers 1298 CO2−brine IFT data including 484 for pure water. The revised CO2−brine IFT correlation accurately predicts available data for pure CO2−pure water IFT data with an average absolute relative error (AARE) of 2.4% and standard deviation (SD) of 3.1%. Similarly, for CO2−brine IFT correlation achieves an AARE of 2.4% and a SD of 3.5%.

We also examine simple methods for predicting the interfacial tension between water and mixtures of CO2 and other gases. We find that while under ideal conditions the mole-fraction weighted average is a viable approximation to the mixture interfacial tension, it typically overstates IFT in many situations. We propose a minor generalization of Kashefi's (2012) method which has better qualitative behavior and improves predictions with an AARE of approximately 5%.
A New Logistically Simple Solution for Implementing ASP/ACP in Difficult Environments – Evaluation of Concept with High TAN Viscous Crude Oil
Authors: Southwick Jeffrey George , Upamali Karasinghe Nadeeka , Fazelalavi Mina , Weerasooriya Upali Peter , Britton Chris James , Dean Robert Matthew
Published: April 2022

Research on alkali assisted chemical EOR technology with high TAN crude oils have led to developments with liquid organic alkalis and co-solvents (Southwick J., et al., 2020) (Fortenberry, et al., 2015) (Schumi, et al., 2019) (Upamali, et al., 2018). Both concepts afford potential significant cost reduction in field operations but to date it has not been demonstrated that these two concepts can work together.

Monoethanolamine (MEA) alkali and a wide variety of liquid co-solvents are evaluated with high TAN (total acid number) crude oil. Formulations are found that give ultra-low interfacial tension (IFT) at a specified injection salinity. Fine tuning the formulation to different injection salinities can be done by choosing alternate co-solvents (or a co-solvent blend). A formulation comprising 1% MEA and a novel high molecular weight (3,152 g/gmol) co-solvent, 0.5% Glycerin alkoxylate with 30 moles propylene-oxide and 35 moles ethylene-oxide (Glycerin-30PO-35EO), gave ultra-low IFT in 21,000 TDS injection brine and gave 100% oil recovery in Bentheimer sandstone with 3500 ppm FP 3630 as mobility control agent. All oil was produced clean, no separation of emulsion was needed to measure oil recovery.

Alkali consumption tests were also performedwith a high permeability reservoir sandstone. Results confirmed earlier data published with Boise outcrop sandstone (Southwick J., et al., 2020) showing low alkali consumption with MEA. On a mass basis, only 12% of the amount of MEA is consumed relative to sodium carbonate. This reduces the logistical challenges of shipping chemicals to remote locations. MEA is also a low viscosity liquid which further simplifies field handling.
A Visualization Study of Low-Tension Polymer Flood for Viscous Oil Reservoirs
Authors: Guo Yujia , Song Haofeng , Mohanty Kishore K.
Published: April 2022

Polymer flood improves the sweep efficiency of viscous oil recovery over water flood. The low-tension polymer (LTP) flood has the potential to improve the displacement efficiency due to low interfacial tension without sacrificing sweep efficiency. The objective of this research is to evaluate the performance of LTP floods as a function of IFT for a viscous oil in a 2D sand pack. Over 20 non-ionic surfactants/co-solvents were tested. A series of sandpack flooding experiments were conducted in a custom-designed 2D visualization cell. The results show that short-hydrophobic surfactants 2EH-xPO-yEO can reduce the IFT to as low as 0.05 dynes/cm. Flooding experiments were performed in sandpacks with and without connate water saturation. For the experiments with connate water saturation, the sandpack was water-wet/intermediate-wet. A base-case polymer flood (without any surfactant) with a viscosity ratio of 10 showed a stable displacement and 82% OOIP oil recovery at the first pore volume injected (PVI).LTP flood with an IFT of 0.1 dynes/cm also showed stable displacement front, but ahigher oil recovery at 1 PVI (90% OOIP).Further reduction in IFT to 0.05 dynes/cm resulted in an unstable displacement and a lower recovery of 65% OOIP. For the experiments without connate water saturation, sandpack was oil-wet, the base-case polymer flood at a viscosity ratio of 10 showed severe fingering and a low oil recovery at 1 PVI (58% OOIP). Adding the nonionic surfactants did not improve displacement efficiency nor oil recovery in oil-wet sandpacks.
First Nanoparticle-Based EOR Nano-EOR Project in Japan: Laboratory Experiments for a Field Pilot Test
Authors: Kaito Yutaro , Goto Ayae , Ito Daisuke , Murakami Satoru , Kitagawa Hirotake , Ohori Takahiro
Published: April 2022

"Nanoparticle-based enhanced oil recovery (Nano-EOR)" is an improved waterflooding assisted by nanoparticles dispersed in the injection water. Many laboratory studies have revealed the effectiveness of Nano-EOR. An evaluation of the EOR effect is one of the most critical items to be investigated. However, risk assessments and mitigation plans are as essential as investigation of its effectiveness for field applications. This study examined the items to be concerned for applying Nano-EOR to the Sarukawa oil field, a mature field in Japan, and established an organized laboratory and field tests workflow. This paper discusses a laboratory part of the study in detail.

This study investigated the effect and potential risks of the Nano-EOR through laboratory experiments based on the workflow. The laboratory tests used surface-modified nanosilica dispersion, synthetic brine, injection water, and crude oil. The oil and injection water were sampled from a wellhead and injection facility, respectively, to examine the applicability of the EOR at the Sarukawa oil field. The items of the risk assessment involved the influence on an injection well's injectivity, poor oil/water separation at a surface facility, and contamination of sales oil.

A series of experiments intended for the Sarukawa oil field showed that 0.5 wt. % nanofluid was expected to contribute to significant oil recovery and cause no damage on an injection well for the reservoir with tens of mD. This is considered a favorable result for applying Nano-EOR to Sarukawa oil field because it contains layers of tens mD. Furthermore, the experiments also showed that 0.5 wt.% nanofluid did not lead to poor oil/water separation and contamination of sales oil. Thus, field tests are designed with this concentration.

This paper introduces the entire study workflow and discusses the detailed procedure and results of experiments investigating the Nano-EOR effect and potential risks.
Modeling of High Pressure and Temperature Microemulsion Experiments using HLD-NAC Based Equation of State
Authors: Magzymov Daulet , Johns Russell T. , Hashim Hafsa , Dindoruk Birol
Published: April 2022

Surfactant flooding is a promising technique that can reduce interfacial tension (IFT) between oil and water to ultra-low values, mobilizing previously trapped oil. For reservoirs at moderate to high pressures, understanding and modeling how pressure affects the phase behavior of a surfactant-brine-oil system is important to the design and implementation of an efficient/cost-effective surfactant flooding project. Typically, however, phase behavior experiments and models of that phase behavior are made only at low pressures. The main objective of this paper is to show how to model experimental data in a unified way for a large range of pressure, temperature, and other parameters, using hydrophilic-lipophilic deviation (HLD) and net-average curvature (NAC) based equation-of-state (EoS).

Pressure and temperature scans show that pressure has a significant effect on the surfactant microemulsion phase behavior, shifting it from an optimal three-phase system at low pressure to a non-optimal two-phase system at high pressure. Further, multiple scans at different oil-water ratios show a shift in the optimum indicating that phase behavior partitioning of the various components is changing with oil saturation. We obtained good fits of all experimental data including all two and three-phase regions using a single tuned HLD-NAC EoS. This is the first attempt to model such complex phase behavior with a large variation in T, P, and compositions, which also demonstrates the type of data needed for an accurate EoS. When input into a numerical simulator, the tuned EoS improves the predictions of the resulting phase behavior (size and shape of the two-phase lobes and three-phase regions) and IFTs with changing pressure, temperature, salinity, oil-water ratios, and surfactant/alcohol concentrations.
Review of Offshore Chemical Flooding Field Applications and Lessons Learned
Authors: Han Ming , Ayirala Subhash , Al-Yousef Ali
Published: April 2022

This paper presents an overview of both research advancements and field applications of offshore chemical flooding technologies. Along with offshore oilfield development strategies that require maximization of oil production in a short development cycle, chemical flooding can become a potential avenue to accelerate oil production in secondary oil recovery mode. This makes it different from onshore chemical flooding processes that mostly focus on enhanced oil recovery in matured or maturing reservoirs. The advancements of offshore chemical flooding field applications are reviewed and analyzed. By summarizing offshore application cases, it also assesses the chemical formulations applied or studied and injection/production facilities required in the offshore environments. Main technical challenges are presented for scaling up the applications on offshore platforms or floating production storage and offloading (FPSO) systems.

The technologies reviewed include polymer flooding, surfactant-polymer flooding, and alkaline-surfactant-polymer flooding. By assessing the technology readiness level of these technologies, this study presents their perspectives and practical relevance for offshore chemical flooding applications. It has been long realized that chemical flooding, especially polymer flooding, can improve oil recovery in offshore oil fields. The applications in Bohai Bay (China), Dalia (Angola), and Captain (North Sea) provide the know-how workflows for offshore polymer flooding from laboratory to full field applications. It is feasible to implement offshore polymer injection either on platform or FPSO system. It is recommended to implement polymer flooding at early stage of reservoir development in order to maximize the investment of offshore facilities. By tuning the chemistry of polymer products, they can present very good compatibility with seawaters. Therefore, choosing a proper polymer is no longer a big issue in offshore polymer flooding.

There are also some interesting research findings reported on the development of novel surfactant chemistries for offshore applications. The outcome from a number of small-scale trials including the single well tracer tests on surfactant, alkaline-surfactant, surfactant-polymer in offshore Malaysia, Abu Dhabi, Qatar, and South China Sea provided valuable insights for the feasibility of chemical flooding in offshore environments. However, the technology readiness levels of surfactant-based chemical flooding processes are still low partially due to their complex interactions with subsurface fluids and lack of much interest in producing residual oil from matured offshore reservoirs. Based on the lessons learned from offshore applications, it can be concluded that several major challenges still need to be overcome in terms of large well spacing, reservoir voidage, produced fluid treatment, and high operational expense to successfully scale up surfactant based chemical flooding processes for offshore applications.
Chronic cough in postmenopausal women and its associations to climacteric symptoms
Authors: Ziller Volker , Oppermann Thea Sophie , Cassel Werner , Hildebrandt Olaf , Kroidl Rolf , Koehler Ulrich
Published: April 2022

Background
Postmenopausal women often have chronic cough, which is likely caused by hormonal changes affecting lung function and the mucous membrane of the airways, causing hypersensitivity of the cough reflex. Therefore, postmenopausal hormonal changes could play a key role in the association between increased cough and menopause. The aim of this study is to evaluate the relation of chronic cough and postmenopausal symptoms.
Methods
We performed a questionnaire-based cohort study in generally healthy postmenopausal women (age 45–65 years). Women with cough of known origin were excluded. Comorbidities, medication and baseline data were collected. The Menopause Rating Scale II (MRS II) was combined with the Leicester Cough Questionnaire (LCQ). Groups were divided in chronic cough versus non-coughing participants, chronic cough was defined as ‘symptoms for over 8 week’. We performed correlations and logistic regression for predicting cough based on postmenopausal symptoms.
Results
66 of 200 women (33%) reported mild to heavier symptoms of chronic cough for over 8 weeks. No significant differences in baseline data (age, BMI, onset of menopause, years since menopause, concomitant diseases, and medication) were found between coughing and non-coughing women. The MRS II showed higher menopausal symptoms in patients with cough, with significant differences in 2 of the 3 MRS-domains (urogenital (p < 0.001) and somato-vegetative (p < 0.001)). Climacteric symptoms strongly correlated with parameters of cough (p < 0.001). On the basis of the MRS total score (p < 0.001) and the somato-vegetative and urogenital domains (p < 0,05), the prediction for respiratory complaints could be shown.
Discussion
Chronic cough was significantly associated with menopausal symptoms. Therefore chronic cough as a possible climacteric symptom and its underlying mechanisms should be further explored.
Neuropathology of Yellow Fever Autopsy Cases
Authors: Frassetto Fernando , Rosemberg Sergio
Published: April 2022

Objective: We analyzed morphologically and immunohistochemically the brains of yellow fever patients who underwent autopsy, in order to identify and characterize neuropathological changes, which have few descriptions in the literature. The data were compared with brains collected from individuals without the disease, as a control group. Both cases and controls were subdivided according to the presence or absence of co-concurrent septic shock, in order to exclude changes of the sepsis associated encephalopathy.Results: All cases and controls presented, at least focally, neuropathological changes, which included edema, meningeal and parenchymal inflammatory infiltrate and hemorrhages, and perivascular inflammatory infiltrate. We did not find an unequivocal aspect of encephalitis. The only parameter that, after statistical analysis, can be attributed to the presence of yellow fever, was the perivascular inflammatory infiltrate. Since most of the parameters evaluated did not show statistically significant differences between cases and controls, an explanation for the presence of neuropathological findings may be the vascular changes, consequent to shock induced endotheliopathy, associated with stimulation of the immune system inherent to systemic infectious processes.
Constraint-Following Control for Uncertain Mechanical Systems: An Intelligent Multi-Agent Game-Theoretic Approach
Authors: Yu Rongrong , Wang Guofeng , Bai Jindong , Chen Ye-Hwa , Zhang Qiang
Published: April 2022

Practically all performance requirement of systems can be formulated as constraints. In engineering, systems are tasked, via proper control design, to follow the constraints. There are however two major challenges. The first is that the system possesses uncertainty, which may be (possibly fast) time-varying. The second is that systems are mostly nonlinear, due to effects such as nonlinear elasticity, etc. To resolve the challenges, a novel performance measure β^ is introduced as a dynamic depiction of the constraint-following error. A new control design is proposed based on this measure. The control design procedure includes two phases. The first phase is to design a control scheme, based on a feasible parameter (meaning the parameter only needs to be selected within a certain range), which renders guaranteed performance regardless of the uncertainty. After that, the second phase is to seek an optimal design for the control parameters. This task is resolved by an intelligent multi-agent game-theoretic approach. We consider there are multi-agents in the design process, each addresses a design consideration. However these considerations are opposite: with one's decrease (or increase) will increase (or decrease) the other. Agents are to cooperate with each other intelligently to reach the optimal choice of the design parameters. The design is applied to an active suspension system and the performance is verified.
Predicting the potential global distribution of an invasive alien pest Trioza erytreae (Del Guercio) (Hemiptera: Triozidae)
Authors: Aidoo Owusu Fordjour , Souza Philipe Guilherme Corcino , Silva Ricardo Siqueira , Júnior Paulo Antonio Santana , Picanço Marcelo Coutinho , Kyerematen Rosina , Sètamou Mamoudou , Ekesi Sunday , Borgemeister Christian
Published: April 2022

The impact of invasive alien pests on agriculture, food security, and biodiversity conservation has been worsened by climate change caused by the rising earth’s atmospheric greenhouse gases. The African citrus triozid, Trioza erytreae (Del Guercio; Hemiptera: Triozidae), is an invasive alien pest of all citrus species. It vectors the phloem-limited bacteria “Candidatus Liberibacter africanus” and “Ca. L. asiaticus”, the causal agents of citrus greening disease or huanglongbing (HLB). Understanding the global distribution of T. erytreae is critical for surveillance, monitoring, and eradication programs. Therefore, we combined geospatial and physiological data of T. erytreae to predict its global distribution using the CLIMEX model. The model’s prediction matches T. erytreae present-day distribution and shows that large areas in the Mediterranean region are suitable for the pest. The model predicts habitat suitability in the major citrus-producing countries, such as Brazil, China, India, and the USA. In the SRES A1B and A2 scenarios, the model predicts a reduction in habitat suitability from the current time to 2070. The findings show that global citrus production will continue to be threatened by T. erytreae. However, our study provides relevant information for biosecurity and risk assessment.
Daily average relative humidity forecasting with LSTM neural network and ANFIS approaches
Authors: Ozbek Arif , Ünal Şaban , Bilgili Mehmet
Published: April 2022

Because hurricanes, droughts, floods, and heat waves are all important factors in measuring environmental changes, they can all result from changes in atmospheric air temperature and relative humidity (RH). Besides, climate, weather, industry, human health, and plant growth are all affected by RH. Accurately and consistently forecasting RH is a challenge due to its non-linear nature. The present study tried to predict one day ahead of RH in determined provinces from different climatic regions of Turkey (Ankara, Erzurum, Samsun, Diyarbakır, Antalya, and Bilecik) using long short-term memory (LSTM) and adaptive neuro-fuzzy inference system (ANFIS) with fuzzy c-means (FCM) based machine learning models. As evaluation criteria, root mean square error (RMSE), mean absolute error (MAE), and correlation coefficient (R) were employed. The outcomes from the forecasting models were also validated using observed data. During the testing stage, the smallest MAE and RMSE values were discovered to be 5.76% and 7.51%, respectively, in Erzurum province, with an R-value of 0.892 when using the LSTM method. Moreover, the smallest MAE and RMSE values were obtained to be 5.95% and 7.67% respectively, in Erzurum province with an R-value of 0.887 using the ANFIS model according to the hourly RH prediction. The results indicate that both the LSTM and ANFIS approaches performed well in daily RH prediction, with the LSTM and ANFIS approaches producing nearly identical results.
Effect of pituitary adenoma consistency on surgical outcomes in patients undergoing endonasal endoscopic transsphenoidal surgery
Authors: Cancela Alberto Acitores , Rodríguez Berrocal V , Pian Héctor , Díez Juan José , Iglesias Pedro
Published: April 2022

Background: Most pituitary adenomas (PAs) are considered to have a soft tumor consistency. However, there is a non-negligible percentage (5-13%) of tumors presenting or exhibiting a fibrous consistency that would entail a more difficult and complicated surgical excision with higher surgical morbidity and mortality rates.Purpose: To analyze the clinical consequences of PA tumor consistency on the surgical outcomes in patients undergoing endonasal endoscopic transsphenoidal (EET) pituitary surgery.Methods: An ambispective study of patients with PAs operated on through an EET approach in two Spanish tertiary hospitals over the last 12 years. A total of 226 consecutive interventions were carried out in the Neurosurgery Departments of the Hospital Universitario Ramón y Cajal (HURC) and the Hospital Universitario Puerta del Sur by the same neurosurgeon. PAs were grouped into soft (n = 150) and fibrous (n = 76). All patients underwent hormonal and magnetic resonance imaging (MRI) studies before and after surgery. In addition, neurosurgical complications were recorded in each patient.Results: Fibrous adenomas were independently associated with lower resection rates compared to soft adenomas (fibrous gross total resection [GTR] rate 48.7% vs. 76.3%, p < 0.001), even in those adenomas without invasion of the cavernous sinus (Knosp grades 0, I, and II). There were more intraoperative cerebrospinal fluid (CSF) leaks in patients with fibrous PAs. Moreover, fibrous PAs showed higher rates of postoperative hypopituitarism, permanent diabetes insipidus (DI) and postoperative treatments (hormonal treatment and radiotherapy). The excision of a fibrous PA required a longer surgical time (22.5 minutes more than soft PAs, p = 0.014), regardless of other factors.
Theoretical Assessments, Optical and Electrochemical Properties of the Alkoxylated Bischalcone as Emissive Material in Single Layer OLED
Authors: Saidin Syaharil , Khairul Wan M. , Rahamathullah Rafizah , Mohammed Mas , Yusoff Farhanini , Sarih Norazilawati Muhamad
Published: April 2022

A new bischalcone consisting hexyloxy (-C6H2n + 1) chain based on ‘Donor (D)-π-Donor (D)’ scheme was successfully designed and synthesized to demonstrate as emitting material for single layer OLEDs. Density functional theory assessment (DFT) at B3LYP/6–31G(d,p) were computed to obtain frontier molecular orbitals (FMO), chemical reactivity and molecular electrostatic potential (MEP). The utilization of alkoxy towards the chalcone moiety has increased the solubility and contributed to HOMO-LUMO gap energy level 3.473 eV by UV–vis spectroscopy and were found to have good agreement with theoretical calculations. The investigation on their optical, electrochemical and thermal behaviour also were conducted via UV-Vis, cyclic voltammetry (CV), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The entitled alkoxylated bischalcone (CSAB) revealed good thermal stability up to 300˚C and showed high glass transition temperatures. At positive potential, a quasi-reversible oxidation (Eox 1/2) peak at 2.40 V and negative potentials exhibited reduction peak at 0.78 V, respectively. The application of CSAB was tested in the form thin film in respect of their conductivity of electrical current and electroluminescence behaviour. It gave an intense yellow emission has provided the fundamental understanding on its potentiality featuring alkoxylated bischalcone moiety as solution-processed OLEDs material in optoelectronic interest.
Enhancing the multi-encoder-based cutting force estimation along the stationary axis of a machine tool with multiple inertia dynamics
Authors: Yamamoto Keisuke , Kamba Aya , Takeuchi Kazuhiro , Fujita Jun , Fujimagari Yusuke , Kakinuma Yasuhiro
Published: April 2022

Wideband cutting force sensing is a key technology for process monitoring. Sensorless cutting force estimation using the internal servo information of a machine tool with ball-screw-driven stages has been studied owing to its high maintainability and ease of introduction. In the motor current-based method, the cutting force estimation along the stationary axis is challenging, and the estimation bandwidth is significantly limited owing to the low sensitivity of the motor current in the high-frequency range. The dual-inertia model-based load-side disturbance observer (LDOB) can estimate the cutting force along the stationary axis using the relative position obtained from the rotary encoder and linear encoder, which is installed relatively near the cutting point and has a high sensitivity in the high-frequency range. However, this approach is not applicable to machine tools with complicated structural dynamics. To address this challenge, we propose a cutting force estimation method along the stationary axis using the Kalman filter (KF) based on a multiple inertia model derived solely from the relative position signal. The dynamics, depending on the stage position of the feed drive, were modeled using linear interpolation. Through end milling tests, we confirmed that the cutting force estimation accuracy along the stationary axis of a machine tool with multiple inertia dynamics was significantly improved by the proposed method compared to the current and LDOB-based methods. Additionally, the wideband cutting force could be estimated using the proposed method for bandwidths up to 1000 Hz.
Machine Learning Based Regional Epidemic Transmission Risks Precaution in Digital Society
Authors: Shi Zhengyu , Qian Haoqi , Li Yao , Wu Fan , Wu Libo
Published: April 2022

The contact and interaction of human is considered to be one of the important factors affecting the epidemic transmission, and it is critical to model the heterogeneity of individual activities in epidemiological risk assessment. In digital society, massive data makes it possible to implement this idea on large scale. Here, we use the mobile phone signaling to track the users’ trajectories and construct contact network to describe the topology of daily contact between individuals dynamically. We show the spatiotemporal contact features of about 7.5 million mobile phone users during the outbreak of COVID-19 in Shanghai, China. Furthermore, the individual feature matrix extracted from contact network enables us to carry out the extreme event learning and predict the regional transmission risk, which can be further decomposed into the risk due to the inflow of people from epidemic hot zones and the risk due to people close contacts within the observing area. This method is much more flexible and adaptive, and can be taken as one of the epidemic precautions with high efficiency and low cost.
Paleohydrological change during the Early-Middle Eocene: Insights from Long-lived Green River Formation
Authors: Kuma Ryusei , Hasegawa Hitoshi , Whiteside Jessica H. , Elson Amy L. , Yamamoto Koshi , Mimura Koichi
Published: April 2022

The evolution of Earth’s climate and oceans during the Early Eocene Climatic Optimum (EECO) has been a focus of extensive research, but the continental response to global climate change in this warmer than modern world is poorly understood. This study quantitatively reconstructs terrestrial paleoenvironment and paleohydrological changes as recorded in the early–middle Eocene (52.7‒43.8 Ma) lacustrine sedimentary succession of the Green River Formation exposed in Indian Canyon, Uinta Basin, northern Utah, USA. Detailed lithofacies variations and whole rock elemental and mineralogical data reflect lake level changes over the 1000 m-thick succession. By comparing the lithofacies and the major element compositions and clay mineralogies, we show that Ca/Al ratio can be utilized as a proxy of lake level, Mn/Fe ratio as a proxy of lake bottom-water redox conditions, and K/Al ratio and kaolinite abundance as proxies of chemical weathering rates. Based on principal component analysis of the major elements and mineralogy, the first principal component is interpreted to represent paleo-hydrological changes, involving variations in the lake level and degree of chemical weathering. Comparison of this record of paleohydrological change for the mid-latitude region of North America with stable δ18O and δ13C data for benthic foraminifera, which reflect global climatic change, indicates wetter periods correspond to intervals of lighter δ18O and heavier δ13C values, and vice versa. These results show that the extremely organic-rich “Mahogany Zone” in this sequence corresponds to the transitional period between the EECO and cooler middle Eocene (ca. 48.7 Ma). This implies that climatic instability and resultant environmental stress during this transitional climate state led to massive blooms of Botryococcus green algae in Lake Uinta, the remains of which are the source of organics preserved in the Mahogany Zone.
Amphoterin-Induced Gene and Open Reading Frame 2 (AMIGO2) Interacts with CAPN2 and Promotes the Proliferation and Migration of Hypopharyngeal Cancer Cell
Authors: Gu Wei , Niu Yanyan , Huo Hong , Yang Dahai , Jin Xiaofeng , Wang Jian
Published: April 2022

Background: Amphoterin-induced gene and open reading frame 2 (AMIGO2) has been reported to play a detrimental role in multiple cancer types. However, the precise role of AMIGO2 in hypopharyngeal squamous cell carcinoma (HPSCC) remains elusive. Methods: Bioinformatic analysis was employed to identify the differential expression and prognostic value of AMIGO2 in the head and neck cancer. Proliferation, apoptosis, and migration assays were then conducted after short hairpin RNA-mediated knockdown of AMIGO2 in FaDu cell line and in xenograft mouse model. Co-immunoprecipitation and mass spectrometry analysis were performed to determine the protein interaction between AMIGO2 and CAPN2. Rescue experiments with respect to the overexpression of CAPN2 were also performed. RNA sequencing after AMIGO2 knockdown with and without CAPN2 overexpression were conducted, followed by pathway enrichment analysis.Results: AMIGO2 expression was up-regulated in head and neck cancer and correlated with a poor prognosis. Functionally, HPSCC cell proliferation and migration were significantly inhibited in vivo and in vitro upon AMIGO2 knockdown. AMIGO2 binds to CAPN2 in cell context, and overexpression of CAPN2 could effectively reverse the inhibition from AMIGO2 knockdown. Bioinformatics analysis based on RNA sequencing indicated that the interaction between AMIGO2 and CAPN2 might be involved in multiple signaling pathways.Conclusions: Our work suggests that AMIGO2 promotes the proliferation and migration of HPSCC by interacting with CAPN2, implying that AMIGO2 can be therapeutically targeted to treat HPSCC.
Multi-scale chirp sparse representation for autonomous system non-stationary signal with Fast Varying Instantaneous Frequency
Authors: Yan Lu , Juan Du
Published: April 2022

Autonomous system is an emerging AI technology based on latest advances in intelligence, cognition, computing and systems science without human intervention, which is widely applied in the field of Internet of things, mechanical condition monitoring system and so on. With the rapid development of industry 4.0, autonomous system’s natural characteristic and application field determine that its corresponding signal presents multi-component, modulation coupling, non-stationary feature with fast time-varying instantaneous frequency (IF). Considering non-stationary signal contains system state information, how to effectively compute IF and realize signal decoupling separation plays an important role in autonomous system perception and making decision. In this paper, a sparse representation method called multi-scale chirp sparse representation (MSCSR) is introduced to to identify, extract and trend IF for achieving a highly concentrated time-frequency energy comparable to the standard IF estimation methods, simulation demonstrates that the proposed method performs better than traditional Hilbert-Huang transform and variational mode decomposition(VMD) combination with synchrosqueezing wavelet transform. Furthermore, an adaptive time-varying filter is constructed using the extracted instantaneous frequency to decouple non-stationary fast signal. Ultimately, by rapid instantaneous frequency fluctuation experiment, the effectiveness of proposed method for fast strong time-varying signal is validated, it can effectively extract rapid oscillation instantaneous frequency, and the error is less than 5%.
Celsr3 inactivation in the brainstem impairs spinal-descending axon development and mouse behaviors in motor coordination and mechanic-induced response
Authors: Chen Boli , Li Fuxiang , Jia Bin , So Kwok-Fai , Wei Ji-An , Liu Yuchu , Qu Yibo , Zhou Libing
Published: April 2022

Inactivation of Celsr3 in the forebrain results in defects of longitudinal axonal tracts such as the corticospinal tract. In this study, we inactivated Celsr3 in the brainstem using En1-Cre mice (Celsr3 cKO) and analyzed axonal and behavioral phenotypes. Celsr3 cKO animals showed an 83% reduction of rubrospinal axons and 30% decrease of corticospinal axons in spinal segments, associated with increased branching of dopaminergic fibers in the ventral horn. A decrease of spinal motoneurons, neuromuscular junctions and electromyographic signal amplitude of the biceps were also found in mutant animals. Mutant mice had impaired motor coordination and defective response to heavy mechanical stimulation, but no disability in walking and food-pellet handling. Transsynaptic tracing demonstrated that rubrospinal axons synapse on spinal neurons in the deep layer of the dorsal horn, and mechanical stimulation of hindpaws induced strong calcium signal of red nuclei in control mice, which was less prominent in mutant mice. In conclusion, Celsr3 regulates development of spinal-descending axons and the motor-network in cell and non-cell autonomous manners, and the maturation of the rubrospinal system is required for motor coordination and response to mechanical stimulation.
An Optimal Operation Method for Parallel Hydropower Systems Combining Reservoir Level Control and Power Distribution
Authors: Wu Xinyu , Lei Yuan , Cheng Chuntian , Ying Qilin
Published: April 2022

Parallel hydropower systems encounter a high risk of spillage in flood periods. Therefore, controlling spillage should be considered when hydropower systems increase power generation and satisfy power grid demand. To meet multiple operation targets, an effective operation method needs to precisely control reservoir level and quickly adjust power schedule based on real-time load changes. In this paper, an optimal operation method for parallel hydropower systems combining reservoir level control and power distribution is proposed. The method generates reservoir level control rules using a multi-objective simulation method for no gird demands operation, and obtain power distribution schedule considering spill risk and non-storage losses for gird demands. Taking a parallel system in southwest China as an example, the results show that the method can product annual power generation of 55.2 billion kWh, which has a 6.1% improvement compared to regular method. And it has the ability to precisely control daily water level and quickly adjust power distribution. It can be applied to parallel systems and has favorable results in power generation, peak shaving, and especially spillage reducing.
Chemical composition of Artemesia herba alba essential oil and its larvicidal and pupicidal effects against Culex pipiens (Diptera; Culicidae)
Authors: Abdelali Salma kaoutar , Souttou Karim , Elhassani Mohamed Kacimi , Aissaoui Linda
Published: April 2022

Aretemisia herba alba Asso (A.herba alba) (Asteraceae) is widely used in herbal medicine it has a real mine of natural molecules like davanone which is a very interesting product on the international market. The present research proposes a method for controlling the pre-imaginary stages of Culex pipiens (L4 and pupae) based on essential oil of Artemisia herba alba. The aerial part of this plant was extracted by hydrodistillation which gave a yield of 1.5. Then it was analyzed by gas chromatography coupled to the mass spectrometry (CPG / SM) for the determination of its chemical composition. The results of the analysis showed that the oil of A.herba alba is a davanone chemotype which consists mainly of davanone (48.8%). Three concentrations (1µl/ml, 5µl/ml and 10µl/ml) are prepared and directly tested on larvae (L4) and pupae. The results show that the essential oils have an important larvicidal and pupicidal activity. This efficiency is expressed by the calculated toxicological parameters which are successively LC50 and LC90, for larvae 3.278 µl/ml and 7.573 µl/ml, and for pupae 1.213 µl/ml and 2.288 µl/ml.
Failure mode classification for condition-based maintenance in a bearing ring grinding machine
Authors: Ahmer Muhammad , Sandin Fredrik , Marklund Pär , Gustafsson Martin , Berglund Kim
Published: April 2022

Technical failures in machines are major sources of unplanned downtime in any production and result in reduced efficiency and system reliability. Despite the well established potential of Machine Learning techniques in condition-based maintenance (CBM), the lack of access to failure data in production machines has limited the development of a holistic approach to address machine-level CBM. This paper presents a practical approach for failure mode prediction using multiple sensors installed in a bearing ring grinder for process control as well as condition monitoring. Bearing rings are produced in a set of 7 experimental runs, including 5 frequently occurring production failures in the critical subsystems. An advanced data acquisition setup, implemented for CBM in the grinder, is used to capture information about each individual grinding cycle. The dataset* is pre-processed and segmented into grinding cycle stages before time and frequency domain feature extraction. A sensor ranking algorithm is proposed to optimize feature selection for failure classification and the installation cost. Random forest models, bench-marked as best performing classifiers, are trained in a two-step classification framework. The presence of failure mode is predicted in the first step and the failure mode type is identified in the second step using the same feature set. Defining the feature set in the failure detection step improves the predictor generalization with the classifiers' performance accuracy of 99% on the test dataset. The presented approach demonstrates an efficient failure mode classification by selecting crucial sensors resulting in a cost effective CBM implementation in a bearing ring grinder
Synthesis and in vitro SAR evaluation of natural vanillin-based chalcones tethered quinolines as antiplasmodial agents
Authors: Andhare Nitin H. , Anas Mohammad , Rastogi Sumit K. , Manhas Ashan , Thopate Yogesh , Srivas Kumkum , Kumar Niti , Sinha Arun Kumar
Published: April 2022

In pursuit of antimalarial drug, to overcome the drug resistance and the risk of drug-drug interactions, the chalcone hybrids and their structure-activity relationship for the antimalarial activity studied against chloroquine sensitive as well as multi-drug resistant strain of Plasmodium falciparum. Our study has revealed that 7- Chloro quinoline groups on chalcone increase anti-malarial potency, while the positional interchange of these groups decreases the efficacy. Particularly, chloro-substituent provided potent analogues which were easily derived from naturally available vanillin. The most active compounds were relatively non-toxic and structure-activity relationship study suggested that 7-chloroquinoline group when attached with triazole linkage increased the antimalarial potential of the compound against both chloroquine-sensitive and multidrug resistant strain.
Occupational health and safety: a study on worker illness
Authors: Magalhães Lídia Maria Costa Araújo , Costa Ketyllem Tayanne da Silva , Capistrano Gustavo Nepomuceno , Leal Maryanna Damasceno , de Andrade Fábia Barbosa
Published: April 2022

Background: This study aimed to evaluate and describe the indicators of occupational health, with a focus on the medical expertise and periodic medical examination. Methods: This is exploratory-descriptive, cross-sectional, documentary, quantitative, and retrospective research, in the historical series: 2011 to 2015. Results: The number of lost days of work per worker and the frequency of licenses increased despite the decrease in the Absenteeism Duration Index and stabilization of the Frequency of Medical Workers. As for the adhesion of the workers to the Periodic Medical Examinations, it was decreasing, with a higher percentage in the year 2012 (35.3%). During the analyzed period, 5,186 workers performed the Periodic Medical Examination, and the majority (60.6%) presented non-ideal weight, 41.1% were sedentary, 33.2% had dyslipidemia, 29.0% were alcoholic, 3.2% were smokers, 5.9% had diabetics, and 16.4% reported high noise in the workplace, 27.8% inadequate lighting and 35.9% inadequate work furniture. Conclusions: The results highlight the need to maintain and strengthen the Worker Health and Safety Policy with emphasis on surveillance, aiming at the promotion and protection of the health of the workers, based on the elaboration of the epidemiological profile of health and, consequently, the implementation of positive impact strategies.