bluuebunny/crossref_metadata_2025 huggingface dataset:
Chromium (III) Ions Were Extracted from Wastewater Effluent Using a Synergistic Green Membrane with a BinaryCombination of D2EHPA and Kerosene
Authors: Sarfraz Sadaf , Abid Akmal Javed , Javed Mohsin , Iqbal Shahid , Aljazzar Samar O. , Zahra Manzar , Alrbyawi Hamad , Elkaeed Eslam B. , Somaily H. H. , Pashameah Rami Adel , Alzahrani Eman , Farouk Abd-ElAziem
Published: October 2022

This study used a supported liquid membrane system (SLM) using Celgard 2400 polypropylene as the support, di(2-ethylhexyl) phosphoric acid (D2EHPA) as the carrier, and kerosene as the diluent. To obtain the best carrier concentration, D2EHPA concentrations between 0.04 and 0.6 M were used. The Cr (III) solutions used in the feed phase had various ionic strengths and were adjusted with NaCl at concentrations ranging from 0.25 to 1.75 M. To maintain a constant pH (4) in the feed phase, a 0.2 M acetic acid–sodium acetate buffer was utilized. Because the rate of Cr (III)-carrier complex formation at the interface of the feed solution and membrane increased up to 20 × 10−4 mol/L, it was discovered that transport of Cr (III) rose with an increase in chromium content in the feeding phase. For the optimization of the various stripping agents, HCl concentration was employed, from 0.25 M to 1.75 M. It was observed that Cr (III) transport increased with the increase in HCl concentration because the transport was at a pH gradient, which was the main driving force. Because of the fact that at the feed phase-membrane contact, D2EHPA combined with chromium ions to form the Cr (III)-carrier complex and released H+ protons, in the feed phase, the Cr (III)-carrier complex was diffused into a stripping phase, wherein Cr (III) ions were stripped and the carrier was reversibly protonated again.
Low-Pt-Based Sn Alloy for the Dehydrogenation of Methylcyclohexane to Toluene: A Density Functional Theory Study
Authors: Obodo Kingsley Onyebuchi , Ouma Cecil Naphtaly Moro , Bessarabov Dmitri
Published: October 2022

Spin-polarized van der Waals corrected density functional theory calculations were applied to Sn–Pt alloys with Pt content ≤ 50% (referred to as low Pt alloys) to evaluate their catalytic activity towards the dehydrogenation of methylcyclohexane (MCH), with the formation of toluene as product. The calculated adsorption energies of MCH, its intermediates and toluene showed that these molecules bind on the considered Sn–Pt alloys. Sn–Pt alloys had the lowest dehydrogenation energetics, indicating that the activity of this catalytic material is superior to that of a pristine Pt catalyst. Desorption of the intermediate species was feasible for all Sn–Pt alloy configurations considered. The catalytic dehydrogenation reaction energetics for the various Sn–Pt alloy configurations were more favourable than that achieved with pristine Pt surfaces. The current study should motivate experimental realization of Sn–Pt alloys for the catalytic dehydrogenation reaction of MCH.
Increased Risk of Generalized Anxiety Disorder According to Frequent Sedentary Times Based on the 16th Korea Youth Risk Behavior Web-Based Survey
Authors: Song Hongsun , Lee Kihyuk
Published: October 2022

This study aimed to identify the association between sedentary behavior and anxiety disorders in 53,510 Korean adolescents. It analyzed data from the 16th (2020) Korea Youth Risk Behavior Web-based Survey (KYRBS). The dependent variable was the generalized anxiety disorder-7 (GAD-7). The GAD-7 scores were divided into normal, mild, moderate, and severe levels. The independent variables were sedentary time for learning, other sedentary times, total sedentary time, and regular physical activity. The confounding variables were sex, grade, stress, depression, substance abuse, suicidal thoughts, violent victimization, drinking, smoking, sleep satisfaction, and smartphone addiction. A chi-squared test, one-way analysis of variance, and logistic regression analysis were used for analysis. After adjusting for all confounding variables, the risk of severe level in GAD-7 increased by 1.045 times each time the sedentary time for learning based on increased by one hour. In other sedentary time and total sedentary time, the risk of severe level in GAD-7 increased by 1.025 times and 1.045 times per hour, respectively. However, in regular physical activity, after adjusting for the confounding variables, there was no significant association with the GAD-7 levels. Therefore, to prevent generalized anxiety disorders in Korean adolescents, it is necessary to reduce the overall sedentary times including sedentary time for learning.
Application of Electrochemically Reduced Water for New No-Rinse Shampoo: Design and Optimization Using Response Surface Methodology
Authors: Duangjit Sureewan , Sritananuwat Phaijit , Bumrungthai Sureewan , Ngawhirunpat Tanasait , Takayama Kozo
Published: October 2022

Coronavirus disease (COVID-19) cases are continuing to rise around the world, with more than 607 million confirmed cases and more than 6.51 million deaths as of September 2022. The World Health Organization (WHO) has emphasized the importance of hygiene in the ongoing COVID-19 pandemic, especially in elderly and bedridden patients. The use of no-rinse shampoo represents a simple change in hair-cleansing products. Daily hospital hair washing for the elderly, bedridden, and ICU patients would be more readily adopted. The objective of this study was to design and optimize a new no-rinse shampoo based on electrochemically reduced water (ERW) using response surface methodology. The relationship between coconut-based surfactant mixtures in a no-rinse shampoo and the resulting physicochemical properties, effectiveness (antibacterial and antifungal activity), and stability of the shampoo was investigated. The vesicle size, size distribution, zeta potential, conductivity, pH, foamability, wetting time, turbidity, and stability of the model formulation were optimized. The optimal formulation with the appropriate physicochemical properties and stability was selected. The effectiveness of the optimal formulation was compared to that of commercially available products. The dry shampoo (DS4) containing 3.5% of the mixed detergent with ERW may prevent infection by Escherichia coli, Staphylococcus epidermidis, Staphylococcus aureus, and Candida albicans. The no-rinse shampoo based on ERW successfully demonstrated good stability in addition to efficacy in terms of antibacterial and antifungal activity. The treated hair fiber was not significantly different from that of the intact hair fiber. Under the scanning electron microscopy (SEM) and the atomic force microscopy (AFM), the cuticle layer of the treated hair fiber was not damaged. Thus, no-rinse shampoos may reduce the time of hair rinsing and improve the quality of life of caregivers.
Melt-Pool Dynamics and Microstructure of Mg Alloy WE43 under Laser Powder Bed Fusion Additive Manufacturing Conditions
Authors: Soderlind Julie , Martin Aiden A. , Calta Nicholas P. , DePond Philip J. , Wang Jenny , Vrancken Bey , Schäublin Robin E. , Basu Indranil , Thampy Vivek , Fong Anthony Y. , Kiss Andrew M. , Berry Joel M. , Perron Aurélien , Nelson Weker Johanna , Stone Kevin H. , Tassone Christopher J. , Toney Michael F. , Van Buuren Anthony , Löffler Jörg F. , Risbud Subhash H. , Matthews Manyalibo J.
Published: October 2022

Magnesium-based alloy WE43 is a state-of-the-art bioresorbable metallic implant material. There is a need for implants with both complex geometries to match the mechanical properties of bone and refined microstructure for controlled resorption. Additive manufacturing (AM) using laser powder bed fusion (LPBF) presents a viable fabrication method for implant applications, as it offers near-net-shape geometrical control, allows for geometry customization based on an individual patient, and fast cooling rates to achieve a refined microstructure. In this study, the laser–alloy interaction is investigated over a range of LPBF-relevant processing conditions to reveal melt-pool dynamics, pore formation, and the microstructure of laser-melted WE43. In situ X-ray imaging reveals distinct laser-induced vapor depression morphology regimes, with minimal pore formation at laser-scan speeds greater than 500 mm/s. Optical and electron microscopy of cross-sectioned laser tracks reveal three distinct microstructural regimes that can be controlled by adjusting laser-scan parameters: columnar, dendritic, and banded microstructures. These regimes are consistent with those predicted by the analytic solidification theory for conduction-mode welding, but not for keyhole-mode tracks. The results provide insight into the fundamental laser–material interactions of the WE43 alloy under AM-processing conditions and are critical for the successful implementation of LPBF-produced WE43 parts in biomedical applications.
Herlyn-Werner-Wunderlich Syndrome: Case Report and Review of the Literature
Authors: Panaitescu Anca Maria , Peltecu Gheorghe , Gică Nicolae
Published: October 2022

Herlyn-Werner-Wunderlich (HWW) syndrome is a very rare congenital malformation of the urogenital tract involving both the müllerian and the wolffian ducts, and it consists of the association of didelphys uterus, ipsilateral obstructed hemivagina, and ipsilateral kidney agenesis. Its etiology is related to the abnormal development of two embryonic structures—mesonephros and paramesonephros—although its precise mechanism is not known, but theories involving signaling molecules and gene expression are studied for potential explanations. Because of its rarity, there is limited literature on this subject. We present a case diagnosed in our department and elaborate on management. In HWW syndrome, symptoms appear after menarche and include pelvic pain, with progressive intensity due to the developing of hematocolpos. Menstruation may be present or absent depending on the type of anomaly. The use of magnetic resonance imaging (MRI) is the most recommended method of investigation since, in most cases, at this age, sexual life has not started yet and transvaginal ultrasound cannot be used. Surgical treatment in our case consisted of an exploratory laparoscopy followed by a vaginal surgical approach to resect the vaginal septum of the obstructed hemivagina.
The Usefulness of Calcium/Magnesium Ratio in the Risk Stratification of Early Onset of Renal Replacement Therapy
Authors: Afonso Rita , Marques Roberto Calças , Borges Henrique , Cabrita Ana , Silva Ana Paula
Published: October 2022

Background: A growing number of studies have reported a close relationship between high serum calcium (Ca)/low serum magnesium (Mg) and vascular calcification. Endothelial dysfunction and vascular inflammation seem plausible risk factors for the enhanced progression of kidney disease. The aim of this study was to evaluate the role of the Ca/Mg ratio as a predictor of the early onset of renal replacement therapy (RRT). Methods: This was a prospective study conducted in an outpatient low-clearance nephrology clinic, enrolling 693 patients with stages 4–5 of CKD. Patients were divided into two groups according to the start of renal replacement therapy (RRT). Results: The kidney’s survival at 120 months was 60% for a Ca–Mg ratio < 6 and 40% for a Ca–Mg ratio ≥ 6 (p = 0.000). Patients who started RRT had lower levels of Hb, Ca, Mg, albumin, and cholesterol and higher values of phosphorus, the Ca/Mg ratio, and PTH. High values of phosphorus and the Ca/Mg ratio and low levels of Mg and GFR were independent predictors of entry into RRT. A high Ca/Mg ratio, high phosphorus levels, and low levels of GFR were associated with a cumulative risk for initiation of RRT. Conclusions: In our population, the Ca/Mg ratio is an independent predictive factor for the initiation of a depurative technique.
Knowledge and Perceptions of Molar Incisor Hypomineralisation among General Dental Practitioners, Paediatric Dentists, and Other Dental Specialists in Indonesia
Authors: Dian Enrita , Budiardjo Sarworini Bagio , Ghanim Aghareed , Amir Lisa Rinanda , Maharani Diah Ayu
Published: October 2022

Molar incisor hypomineralisation (MIH) is a qualitative, dental enamel hypomineralisation defect affecting one to four first permanent molars, characterised by the present of asymmetries demarcated opacities, and is prevalent worldwide. An early diagnosis of MIH is crucial, to prevent further complications including the development of dental caries, hypersensitivity, pulp inflammation, and pain. Therefore, a thorough understanding of MIH is of clinical importance. This cross-sectional study aimed to evaluate the knowledge and perception of MIH among general dental practitioners (GD), paediatric dentists (PD), and other dental specialists (DS) in Indonesia using a self-administered questionnaire. Chi-square tests and Kruskal–Wallis tests were employed to analyse the data. A total of 266 dental practitioners—112 GD, 84 PD, and 60 DS—were included in this study and completed the online questionnaire. There were significant differences in the overall knowledge scores between GD, PD, and DS (p < 0.001). Specifically, the different between the tested groups were observed in the knowledge of caries pattern related to MIH and the aetiology of MIH. The majority of PD (83.3%) can differentiate the MIH-related caries pattern from the classic caries pattern. Moreover, the confident level in diagnosing and treating MIH teeth were higher in PD compared to GD and DS (p = 0.000). The majority of dental practitioners in all groups agreed on the necessity to obtain continuing education on MIH including the aetiology, diagnosis, and its treatment to improve their knowledge and confidence in MIH clinical management.
Which Demographic Quintile Benefits from Public Health Expenditure in Nigeria: A Marginal Benefit Analysis
Authors: Ogujiuba Kanayo K.
Published: October 2022

Policymakers concur that social investments are crucial, and that inequality must be decreased to accomplish long-term poverty reduction. Nigeria, one of the 20 poorest countries in the world, has a severely unequal society at the moment, with over 80% of the people living in deep, severe, and pervasive poverty, with an estimated 5% of the population possessing 85% of the country’s resources. This article’s focus is on how benefits are dispersed among various demographic groups. Previous data collection does not reflect the present realities of this topic. For this analysis, in southeast Nigeria, data sets from government agencies and for-profit service providers were utilized. The benefits of distinct quintiles were estimated using a marginal benefit incidence analysis. The results show that governmental spending in Nigeria is not pro-poor and that the country’s southeast governments supported spending for the wealthy rather than the poor. The results show, among other things, that investment in health is not well directed; benefits from primary education and primary healthcare appear to be disproportionately dispersed to the upper class in the states studied, as they are throughout Nigeria. The paper serves as an example of the value of benefit incidence analysis (BIA). This article recommends effective targeted discretionary spending to lower systemic poverty and inequality. If education and health spending were more pro-poor, better education and health outcomes, strong governance, high per capita income, and wider access to information would all be more likely.
Automatic Detection of Diseases in Tunnel Linings Based on a Convolution Neural Network and a Support Vector Machine
Authors: Hou Lili , Zhang Qian , Zhang Ruixue
Published: October 2022

The complexity of diseases in tunnel linings and the interference of clutter and the strong reflection of rebar in ground-penetrating radar (GPR) data are the important factors that lead to the low accuracy and poor automation of disease detection. As consequence, this paper carries out an automatic detection method for hidden lining diseases. Firstly, in order to suppress the interference of strong clutter, the state equation and measurement equation of GPR data are established, and the recursive formula of clutter suppression is deduced. Secondly, combined with a convolution neural network, the network which can suppress the strong reflection of rebar is built. Finally, the multi-dimensional characteristics of disease in the time domain, frequency domain, and time-frequency domain are extracted, and then the support vector machine (SVM) data set is established and the automatic detection method for diseases is formed. The proposed method can avoid the low efficiency of manual interpretation and the over-dependence of detection accuracy of relying upon the experience level of technicians.
FDI, Technology Spillovers, and Green Innovation: Theoretical Analysis and Evidence from China
Authors: Qin Bingtao , Gai Yulu , Ge Liming , Sun Pengbo , Yu Yongwei , Zheng Yi
Published: October 2022

Foreign direct investment (FDI) technology spillovers play an increasingly important role in a host country’s development. Evaluating the positive effect of FDI inflows on green innovation is essential for correct city design. Based on the panel data of 262 cities in China from 2004 to 2018, we first analyzed the impact of FDI technology spillovers on green innovation in Chinese cities and then tested the threshold effect in four absorptive capacity factors: environmental regulation, economic growth, human capital, and industry size. Finally, we compared the time and space of two types of cities crossing the threshold from the perspective of innovative and non-innovative cities. The results show that FDI can significantly promote green innovation in Chinese cities and the promoting effect of FDI on green innovation has nonlinear characteristics, namely, such effects only make sense when absorptive capacity is above the threshold points. Additionally, among the four absorptive capacity factors, the development degrees of innovative cities are ahead of non-innovative cities; in particular, there is a significant difference between them in terms of economic growth. Local governments should develop reasonable policy combination tools according to the absorptive capacity characteristics of different cities to effectively promote the technology spillover effect of FDI and achieve coordinated ecological and economic development.
Dimensioning Microgrids for Productive Use of Energy in the Global South—Considering Demand Side Flexibility to Reduce the Cost of Energy
Authors: Kraft Johann , Luh Matthias
Published: October 2022

Microgrids using renewable energy sources play an important role in providing universal electricity access in rural areas in the Global South. Current methods of system dimensioning rely on stochastic load profile modeling, which has limitations in microgrids with industrial consumers due to high demand side uncertainties. In this paper, we propose an alternative approach considering demand side management during system design which we implemented using a genetic scheduling algorithm. The developed method is applied to a test case system on Idjwi Island, Democratic Republic of the Congo (DRC), which is to be powered by a micro hydropower plant (MHP) in combination with a photovoltaic (PV) system and a battery energy storage system (BESS). The results show that the increased flexibility of industrial consumers can significantly reduce the cost of electricity. Most importantly, the presented method quantifies the trade-off between electricity cost and consumer flexibility. This gives local stakeholders the ability to make an informed compromise and design an off-grid system that covers their electricity needs in the most cost-efficient way.
Self-Derived Wavelet Compression and Self Matching Reconstruction Algorithm for Environmental Data in Complex Space of Coal Mine Roadway
Authors: Xue Xusheng , Wang Chuanwei , Ma Hongwei , Mao Qinghua , Cao Xiangang , Zhang Xuhui , Zhang Guangming
Published: October 2022

A crucial assurance for coal mine safety production, prevention and control, and rescue, which is the fundamental tenet of implementing intelligent coal mining, is the safety, stability, and quick transmission of coal mine roadways. However, because of the complex structure of the roadway environment, such as limited and variable space and numerous pieces of equipment, the wireless communication network is affected by the environment, the data transmission channel characteristics are complex and variable, and the existing data transmission methods are weak in adapting to the changing channel. These factors result in poor stability of the transmission of coal mine roadway environment detection data in the wireless communicative network. As a result, this article investigates the wireless communication systems’ real-time transmission in the intricate environmental setting of a coal mine. Based on the application of multiscale wavelet theory in data compression and reconstruction, an adaptive multiscale wavelet compression model based on the wireless data transmission channel is proposed, with an improved Huffman data compression coding algorithm derived from the multiscale wavelet, so that the environmental data meet the wireless communication channel transmission capability. The proposed algorithm boosts the compression ratio and adaptability of environmental data. A self-matching wavelet reconstruction algorithm is developed to achieve real-time and accurate data reconstruction following self-driven wavelet decomposition. The compression and reconstruction experiment performed during real-time wireless transmission of gas concentration data reveals that the original signal’s compression ratio reaches 74% with minor error and high fidelity. The algorithm provides the theoretical foundation for compression and reconstruction in complex coal mine environments for accurate, stable, and real-time data transmission. It is critical for ensuring reliable data transmission in safe production, prevention and control, rescue, and other operations, and it provides theoretical and technical support for intelligent coal mining.
Medium-Temperature Phosphate Glass Composite Material as a Matrix for the Immobilization of High-Level Waste Containing Volatile Radionuclides
Authors: Frolova Anna V. , Vinokurov Sergey E. , Gromyak Irina N. , Danilov Sergey S.
Published: October 2022

The search for matrices and technological solutions for the reliable immobilization of volatile radionuclides and high-level waste (HLW) components is an actual radiochemical problem. Methods of obtaining of sodium alumino-iron phosphate (NAFP) and iron phosphate (FP) glass composite materials synthesized at temperatures of 450–750 °C, their structure and hydrolytic stability were investigated in this paper. The structure of the samples was studied by XRD and SEM-EDS. It was shown that, in the case of FP materials, the phase composition varies depending on the synthesis temperature, while NAFP materials have a complex multiphase composition at all crystallization temperatures. It has been established that the samples of the obtained glass composite materials have a high hydrolytic stability. At the same time, FP material obtained at 650 °C are the most stable, which makes this medium-temperature method of synthesis promising for the immobilization of volatile HLW components.
LCOE-Based Optimization for the Design of Small Run-of-River Hydropower Plants
Authors: Amougou Claude Boris , Tsuanyo David , Fioriti Davide , Kenfack Joseph , Aziz Abdoul , Elé Abiama Patrice
Published: October 2022

Run-of-river hydropower plants are a cost-efficient technology that produce a power output proportional to the instantaneous flow of water diverted from the exploited stream by exploiting several mechanical, hydraulic, and electric devices. However, as no storage is available, its design and operation is tailored according to the unpredictability of its power generation. Hence, the modelling of this type of power plants is a necessity for the promotion of its development. Accordingly, based on models from the literature, this study proposes a comprehensive methodology for optimally designed small run-of-river hydropower plants based on a levelized cost of energy (LCOE). The proposed methodology aims at facilitating a faster design for more cost-effective and energy-efficient small hydropower plants. Depending on the average daily flow rates and the gross head of a given site, the model proposed in this study calculates the diameter, thickness, and length of a penstock; it also suggests the optimal selection of a turbine, determines the admissible suction head of a turbine for its optimal implementation, and determines the optimal number of turbines, all in order to minimize the LCOE of the proposed project. The model is tested to design a small run-of-river hydropower plant with a capacity of 6.32 MW exploiting the river Nyong in Mbalmayo. The results confirm the profitability of the investment with an LCOE of around 0.05 USD/kWh, which is the lowest limit value of the LCOE range for small hydropower plants, as presented in the IPCC (Intergovernmental Panel on Climate Change) report, assuming a project lifespan of 50 years and a discount rate of 12.5%. These results also show that it may be worth to provide the energy sector with a small hydropower design tool with a graphical interface. In addition, it would be appropriate to use a similar method in an off-grid context where a hydropower plant, with or without storage, is combined with another source to meet the electrical needs of a given population.
Multi-Objective Optimal Design of SPMSM for Electric Compressor Using Analytical Method and NSGA-II Algorithm
Authors: Jo Seong-Tae , Kim Woo-Hyeon , Lee Young-Keun , Kim Yong-Joo , Choi Jang-Young
Published: October 2022

In contrast to internal combustion engine vehicles, electric vehicles (EVs) obtain the power required for the compressor of air conditioning system from an electric source. Therefore, an optimal design for electric motor, the main component of an electric compressor, is essential for improving EV mileage. A multi-objective optimal design is required because the characteristics of the motor are in a trade-off relationship with each other. When the finite element method (FEM) is used, multi-objective optimal designs for the motor take a significant amount of time because of the diversity analyses required for the optimal-model search. To solve this problem, in this study, a multi-objective optimal design method of an SPMSM for an EVs air conditioner system compressor was proposed and applied using the NSGA-II and an analytical method. The validity of the proposed method was confirmed by comparing the characteristics of the optimal design model with those of the initially designed model.
Determinants of Electricity Prices in Turkey: An Application of Machine Learning and Time Series Models
Authors: Ertuğrul Hasan Murat , Kartal Mustafa Tevfik , Depren Serpil Kılıç , Soytaş Uğur
Published: October 2022

The study compares the prediction performance of alternative machine learning algorithms and time series econometric models for daily Turkish electricity prices and defines the determinants of electricity prices by considering seven global, national, and electricity-related variables as well as the COVID-19 pandemic. Daily data that consist of the pre-pandemic (15 February 2019–10 March 2020) and the pandemic (11 March 2020–31 March 2021) periods are included. Moreover, various time series econometric models and machine learning algorithms are applied. The findings reveal that (i) machine learning algorithms present higher prediction performance than time series models for both periods, (ii) renewable sources are the most influential factor for the electricity prices, and (iii) the COVID-19 pandemic caused a change in the importance order of influential factors on the electricity prices. Thus, the empirical results highlight the consideration of machine learning algorithms in electricity price prediction. Based on the empirical results obtained, potential policy implications are also discussed.
Analysis of a New Super High Temperature Hybrid Absorption-Compression Heat Pump Cycle
Authors: Sun Jian , Wang Yinwu , Wu Kexin , Ge Zhihua , Yang Yongping
Published: October 2022

Utilization of high-temperature energy in industrial production processes is often exhausted by huge low-temperature waste heat without recovery. Thus, energy efficiency is quite limited. Heat pumps are widely used as a high-efficiency waste heat recovery system and are divided into vapor compression cycle, driven by electricity, and absorption type, driven by steam or hot water. However, compression heat pumps are quite difficult to reach more than 100 °C due to the temperature and compression limits of compressors and the working medium. Meanwhile, the COP (coefficient of performance) of an absorption heat pump is quite low due to the thermodynamic cycle characteristics. In order to increase the outlet temperature and COP significantly, a new type of compression-absorption hybrid heat pump cycle is presented and simulated. Compared with traditional cycles, this heat pump can reach the heat sink temperature of 200 °C with a highly satisfactory COP. This heat pump could reach the optimal COP of 3.249 when the pressure ratio of the compressor is 6.5, the coupling temperature of the low-pressure stage is 55 °C and the coupling temperature of the high-pressure stage is 73 °C. Exergy analysis shows that evaporators and condensers show better efficiency. This heat pump could be promising in different kinds of heat recovery.
Numerical Simulation of Kelvin–Helmholtz Instability and Boundary Layer Stripping for an Interpretation of Melt Jet Breakup Mechanisms
Authors: Kim Min-Soo , Bang Kwang-Hyun
Published: October 2022

The present study is aimed at investigating the ability of a CFD modeling of liquid–liquid jet breakup to resolve the principal mechanisms relevant to jet breakup as well as submillimeter-scale drop size. It is generally known that jet leading edge breaks up by boundary layer stripping (BLS), and jet lateral surface breaks up by Kelvin–Helmholtz instability (KHI). The jet breakup rate as well as the resulting particle size are important parameters that would largely govern the intensity of a steam explosion in severe reactor accidents. First, a two-dimensional simulation of KHI along the melt-liquid coolant interface was performed using the VOF model in ANSYS Fluent with fine meshes as small as 0.02 mm. The dominant wavelength obtained by FFT analysis of calculated melt volume fractions showed that the fastest growing wavelength from the linear analysis of KHI is seen only at the very early development of the instability, and it increases gradually. Second, a three-dimensional simulation of BLS was performed, and the shapes and sizes of the melt particles were obtained. The particle size distributions from KHI and BLS simulations were compared with COLDJET experimental data of Woods metal and water, and it showed that the finer drops of one millimeter or smaller are produced by Kelvin–Helmholtz instability, and the drops of a few millimeters in diameter are mainly produced by boundary layer stripping.
Research Progress of Applying Distributed Fiber Optic Measurement Technology in Hydraulic Fracturing and Production Monitoring
Authors: Wang Yilin , Wu Zhuoping , Wang Fuyong
Published: October 2022

With the exploration and development of unconventional oil and gas resources, downhole environmental monitoring and data-analysis technologies are becoming more and more important. Distributed fiber optic measurement technology, as a new monitoring technology to obtain accurate data, has a wide range of applications in hydraulic fracturing and production monitoring. It mainly includes: distributed fiber optic temperature sensors (DTSs) to monitor gas lift, identify in-flow fluid types, interpret flow profiles and monitor production enhancement operations; distributed fiber optic acoustic sensors (DASs) to monitor low frequency strain and microseismic and hydraulic fracturing operations; and distributed fiber optic stress sensors (DSSs) to characterize fractures in the near-well area, which have been well applied in the field. This paper describes the current application status of DASs and DSSs in hydraulic fracturing and production monitoring, respectively, from the principle of distributed fiber optic measurement technology. It also points out the limitations of these measurement technologies and the direction of future development. Distributed fiber optic measurement technology has been making technical breakthroughs in recent years, providing strong technical support for the development of unconventional oil and gas resources.
Application of Exergy Analysis in Flue Gas Condensation Waste Heat Recovery System Evaluation
Authors: Zhang Le , Zhai Huixing , He Jiayuan , Yang Fan , Wang Suilin
Published: October 2022

Flue gas condensation heat recovery technology has a good technical and economic performance in industrial exhaust gas waste heat recovery. Thermal efficiency analysis is the traditional analysis method for the flue gas condensation heat recovery system but it cannot reflect the recovered heat degree. Exergy analysis, which can reflect the recovered energy heat degree, was first applied to the evaluation of a flue gas condensation waste heat recovery system in this paper. The calculation method of wet flue gas exergy is more complex as both a heat and mass transfer is presented. Flue gas waste heat exergy efficiency (EE) and the flue gas waste heat exergy utilization rate (EUR) were proposed as the evaluation indexes for exergy analysis. The exergy analysis method was applied to the comparative evaluation of three recovery schemes in a practical project. The results show that when the water vapor content of wet flue gas is less than 10%, the condensed water exergy can be neglected when calculating EE. The EUR could be used as a comprehensive index for comparing different waste heat recovery schemes, and EE could be used to judge whether the energy grade of heat exchange equipment was seriously decreased. Exergy analysis could effectively make up for the deficiency of thermal efficiency analysis that could not reflect the waste heat grade utilization. Exergy analysis and thermal efficiency analysis are recommended to be used simultaneously to make a more comprehensive analysis and evaluation of the system.
Effective Harmonic Cancellation Technique for a Three-Phase Four-Wire System
Authors: Sahoo Buddhadeva , Alhaider Mohammed , Rout Pravat
Published: October 2022

An excess non-linear and unbalanced load application increases the power quality (PQ) problem by injecting harmonic current. The avoidance of neutral current control creates additional PQ problems due to excess circulating current in modern 3φ4W applications. Therefore, this manuscript suggests improved αβ transform-based voltage and current control approaches for both 3φ3W and 3φ4W shunt active filter (SAF) applications. In the proposed approach, a novel combined voltage and current (NCVC) control approach is presented for modern 3φ3W systems by using voltage and closed-loop current controllers. However, due to the absence of a neutral current, the NCVC is not sufficient for 3φ4W system application. Therefore, by considering the current reference parameter generated from the NCVC, a novel harmonic compensation technique (NHCT) is proposed with proper mathematical expressions for the 3φ4W application. To show the importance of NHCT over traditional P-Q-R control, the developed MATLAB/Simulink model is tested by using different 1φ and 3φ nonlinear/unbalanced load conditions. The comparative results indicate that, by using NHCT, the 3φ4W system contains a lesser total harmonic distortion (THD) and harmonic mitigation ratio (HMR), less ripple frequency, an improved power factor, a lesser neutral current, and a balanced active/reactive power condition. From the above comparative analysis results, it is found that the overall improvement percentage is 66.78%. The above findings justify the significance of the NCVC and NHCT approach during both unbalanced and non-linear load-based 3φ4W applications.
The Effect of Pine Wood Nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle on Intestinal Bacterial Community of Insect Vector Monochamus saltuarius (Coleoptera: Cerambycidae)
Authors: Wang Xi-Zhuo , Wang Xiang , Zhang Su-Fang , Zhang Yan-Long , Cao Ye-Fan , Wang Lai-Fa
Published: October 2022

Pine wilt disease (PWD) has caused extensive mortality in pine forests worldwide. The longicorn beetle Monochamus saltuarius, as the vector of the invasive species Bursaphelenchus xylophilus, plays an important role in the infection cycle. Although the gut microbiota and its contribution to health and disease have been extensively documented, it is unclear whether B. xylophilus affects the longicorn gut microbiota because of a lack of understanding of potential temporal changes in the microbial composition of the vector beetles. In this study, we collected beetles at the emergence and mating stages, and divided them into two groups according to whether they carried nematodes. Based on 16S rDNA sequence analysis, 174 bacterial species were identified that belonged to 112 genera, 53 families, and 8 phyla. Bursaphelenchus xylophilus increased the microflora abundance and diversity of the infected M. saltuarius. In addition, Firmicutes and Bacteroidetes were more abundant in infected M. saltuarius at the same developmental stage. Some of the bacteria in these two phyla were the key species in the co-occurrence network of intestinal flora and represented a unique module in the co-occurrence network of infected M. saltuarius. We found some high abundance colonies in the intestinal tract of infected M. saltuarius during the emergence period that were mostly related to metabolism. Compared with the emergence period, there were more similar microorganisms in the intestinal tract of M. saltuarius during the mating period. With the change in growth environment and continuous feeding, the intestinal microorganisms gradually stabilized and became single species.
Introducing New Index in Forest Roads Pavement Management System
Authors: Heidari Mohammad Javad , Najafi Akbar , Borges Jose G.
Published: October 2022

Forest road pavement needs an evaluation methodology based on a comprehensive assessment of road conditions. This research was conducted to evaluate the performance of a method for rating the surface condition of forest roads and eventually to adapt the method to the situation prevailing in a forest road network. The rating method selected as the basis for this experiment was the pavement condition index (PCI) developed by the U.S. Army Corps of Engineers for urban roads. In addition, unpaved road condition index (URCI) that has a good index for unpaved road evaluation used for comparison. A 53 km of forest roads were selected containing the most influential factors and variability of conditions. Eventually, 201 road segments were delineated between 150–300 m in length. Within the given segments, sample plots were set 20 m in length consecutively. It was concluded that the panel scores for distress and surface condition of sample unit and section differed from the forest road pavement condition index (FRPCI), URCI, and PCI. Linear regression was used to derive equations between distress and URCI and PCI scores to determine effective FRPCI parameters that provide a numerical rating for the condition of road segments within the road network, where 0 worlds are the worst possible condition, and 100 is the best possible condition best. In addition, regression analysis showed that the FRPCI model with a 0.77 correlation for the total of the road is a performance index used for the first time in forest roads. This study showed a range of FRPCI from 7.8 to 96.3, different from PCI and URCI ratings (0.85–45 and 1.2–53). The FRPCI index helps forest managers in road maintenance, harvesting, and planning to use road information.
Natural Language Processing and Cognitive Networks Identify UK Insurers’ Trends in Investor Day Transcripts
Authors: Claus Stefan , Stella Massimo
Published: October 2022

The ability to spot key ideas, trends, and relationships between them in documents is key to financial services, such as banks and insurers. Identifying patterns across vast amounts of domain-specific reports is crucial for devising efficient and targeted supervisory plans, subsequently allocating limited resources where most needed. Today, insurance supervisory planning primarily relies on quantitative metrics based on numerical data (e.g., solvency financial returns). The purpose of this work is to assess whether Natural Language Processing (NLP) and cognitive networks can highlight events and relationships of relevance for regulators that supervise the insurance market, replacing human coding of information with automatic text analysis. To this aim, this work introduces a dataset of NIDT=829 investor transcripts from Bloomberg and explores/tunes 3 NLP techniques: (1) keyword extraction enhanced by cognitive network analysis; (2) valence/sentiment analysis; and (3) topic modelling. Results highlight that keyword analysis, enriched by term frequency-inverse document frequency scores and semantic framing through cognitive networks, could detect events of relevance for the insurance system like cyber-attacks or the COVID-19 pandemic. Cognitive networks were found to highlight events that related to specific financial transitions: The semantic frame of “climate” grew in size by +538% between 2018 and 2020 and outlined an increased awareness that agents and insurers expressed towards climate change. A lexicon-based sentiment analysis achieved a Pearson’s correlation of ρ=0.16 (p<0.001,N=829) between sentiment levels and daily share prices. Although relatively weak, this finding indicates that insurance jargon is insightful to support risk supervision. Topic modelling is considered less amenable to support supervision, because of a lack of results’ stability and an intrinsic difficulty to interpret risk patterns. We discuss how these automatic methods could complement existing supervisory tools in supporting effective oversight of the insurance market.
Production of Marine Shrimp Integrated with Tilapia at High Densities and in a Biofloc System: Choosing the Best Spatial Configuration
Authors: Holanda Mariana , Wasielesky Wilson , de Lara Gabriele Rodrigues , Poersch Luís H.
Published: October 2022

Integrating marine shrimp and tilapia has been shown to be a viable alternative in a system based on bioflocs, but there is no consensus on the spatial arrangement of farmed animals. The present study aims to (1) compare the performance of shrimp and fish in high density when subjected to polyculture (species in the same tank) and multitrophic (species in different tanks) arrangements, and (2) effects on water quality, especially on organic matter (biofloc). The experiment was carried out for 30 days, and three treatments with bioflocs were evaluated in triplicate: control: shrimp monoculture, polyculture: shrimp and tilapia in the same tank, and multitrophic: shrimp and tilapia in separate tanks. The results show that the best product configuration is the multitrophic system, where the biological control of bioflocs took place, and the best performance of the Pacific white shrimp L. vannamei and Nile tilapia O. niloticus was obtained. Tilapia, as an organic consumer, was effective in controlling bioflocs.
Real-Time Monitoring of the Quality Changes in Shrimp (Penaeus vannamei) with Hyperspectral Imaging Technology during Hot Air Drying
Authors: Xu Wenya , Zhang Fan , Wang Jiarong , Ma Qianyun , Sun Jianfeng , Tang Yiwei , Wang Jie , Wang Wenxiu
Published: October 2022

Hot air drying is the most common processing method to extend shrimp’s shelf life. Real-time monitoring of moisture content, color, and texture during the drying process is important to ensure product quality. In this study, hyperspectral imaging technology was employed to acquire images of 104 shrimp samples at different drying levels. The water distribution and migration were monitored by low field magnetic resonance and the correlation between water distribution and other quality indicators were determined by Pearson correlation analysis. Then, spectra were extracted and competitive adaptive reweighting sampling was used to optimize characteristic variables. The grey-scale co-occurrence matrix and color moments were used to extract the textural and color information from the images. Subsequently, partial least squares regression and least squares support vector machine (LSSVM) models were established based on full-band spectra, characteristic spectra, image information, and fused information. For moisture, the LSSVM model based on full-band spectra performed the best, with residual predictive deviation (RPD) of 2.814. For L*, a*, b*, hardness, and elasticity, the optimal models were established by LSSVM based on fused information, with RPD of 3.292, 2.753, 3.211, 2.807, and 2.842. The study provided an in situ and real-time alternative to monitor quality changes of dried shrimps.
Phycocyanin Protects against High Glucose High Fat Diet Induced Diabetes in Mice and Participates in AKT and AMPK Signaling
Authors: Hao Shuai , Li Fannian , Li Qiancheng , Yang Qi , Zhang Wenjing
Published: October 2022

Phycocyanin is a type of marine natural product and functional food additive. Studies have demonstrated that phycocyanin has potential regulatory effects on glycometabolism, while its function and mechanism, especially in type 2 diabetes mellitus (T2DM), is still unclear. The aim of this study was to investigate the antidiabetic roles and underlying mechanism of phycocyanin in a high glucose high fat diet induced model of T2MD in C57BL/6N mice and a high-insulin-induced insulin-resistant model of SMMC-7721 cells. The results indicated that phycocyanin reduced high glucose high fat diet induced hyperglycemia as well as ameliorated glucose tolerance and histological changes in the liver and pancreas. Meanwhile, phycocyanin also significantly decreased the diabetes-induced abnormal serum biomarker variations, including triglyceride (TG), total cholesterol (TC), aspartate transaminase (AST), and glutamic-pyruvic transaminase (ALT), and increased the superoxide dismutase (SOD) content. Furthermore, the antidiabetic function of phycocyanin was exerted through activating the AKT and AMPK signaling pathway in the mouse liver, which was also verified in the insulin-resistant SMMC-7721 cells due to increased glucose uptake and activated AKT and AMPKα expression. Thus, the present study is the first to indicate that phycocyanin mediates antidiabetic function via activating the AKT and AMPK pathway in high glucose high fat diet induced T2DM mice and insulin-resistant SMMC-7721 cells, which lays a scientific theoretical basis for the potential treatment of diabetes and the utilization of marine natural products.
Mixed Convection of Fractional Nanofluids Considering Brownian Motion and Thermophoresis
Authors: Chen Mingwen , Tian Yefan , Yang Weidong , Chen Xuehui
Published: October 2022

In this paper, the mixed convective heat transfer mechanism of nanofluids is investigated. Based on the Buongiorno model, we develop a novel Cattaneo–Buongiorno model that reflects the non-local properties as well as Brownian motion and thermophoresis diffusion. Due to the highly non-linear character of the equations, the finite difference method is employed to numerically solve the governing equations. The effectiveness of the numerical method and the convergence order are presented. The results show that the rise in the fractional parameter δ enhances the energy transfer process of nanofluids, while the fractional parameter γ has the opposite effect. In addition, the effects of Brownian motion and thermophoresis diffusion parameters are also discussed. We infer that the flow and heat transfer mechanism of the viscoelastic nanofluids can be more clearly revealed by controlling the parameters in the Cattaneo–Buongiorno model.