bluuebunny/crossref_metadata_2025 huggingface dataset:
Experiments on Heat Transfer of Supercritical Pressure Kerosene in Mini Tube under Ultra-High Heat Fluxes
Authors: Yan Jianguo , Liu Shouchun , Guo Pengcheng , Bi Qincheng
Published: March 2020

Heat transfer of supercritical-pressure kerosene is crucial for regenerative cooling systems in rocket engines. In this study, experiments were devoted to measure the heat transfer of supercritical-pressure kerosene under ultra-high heat fluxes. The kerosene flowed horizontally in a mini circular tube with a 1.0 mm inner diameter and was heated uniformly under pressures of 10–25 MPa, mass fluxes of 8600–51,600 kg/m2 s, and a maximum heat flux of up to 33.6 MW/m2. The effects of the operating parameters on the heat transfer of supercritical-pressure kerosene were discussed. It was observed that the heat transfer coefficient of kerosene increases at a higher mass flux and inlet bulk temperature, but is little affected by pressure. The heat transfer of supercritical-pressure kerosene is classified into two regions: normal heat transfer and enhanced heat transfer. When the wall temperature exceeds a certain value, heat transfer is enhanced, which could be attributed to pseudo boiling. This phenomenon is more likely to occur under higher heat flux and lower mass flux conditions. In addition, the experimental data were compared with several existing heat transfer correlations, in which one of these correlations can relatively well predict the heat transfer of supercritical-pressure kerosene. The results drawn from this study could be beneficial to the regenerative cooling technology for rocket engines.
Low Enthalpy Geothermal Systems in Structural Controlled Areas: A Sustainability Analysis of Geothermal Resource for Heating Plant (The Mondragone Case in Southern Appennines, Italy)
Authors: Iorio Marina , Carotenuto Alberto , Corniello Alfonso , Di Fraia Simona , Massarotti Nicola , Mauro Alessandro , Somma Renato , Vanoli Laura
Published: March 2020

In this study, the sustainability of low-temperature geothermal field exploitation in a carbonate reservoir near Mondragone (CE), Southern Italy, is analyzed. The Mondragone geothermal field has been extensively studied through the research project VIGOR (Valutazione del potenzIale Geotermico delle RegiOni della convergenza). From seismic, geo-electric, hydro-chemical and groundwater data, obtained through the experimental campaigns carried out, physiochemical features of the aquifers and characteristics of the reservoir have been determined. Within this project, a well-doublet open-loop district heating plant has been designed to feed two public schools in Mondragone town. The sustainability of this geothermal application is analyzed in this study. A new exploration well (about 300 m deep) is considered to obtain further stratigraphic and structural information about the reservoir. Using the derived hydrogeological model of the area, a numerical analysis of geothermal exploitation was carried out to assess the thermal perturbation of the reservoir and the sustainability of its exploitation. The effect of extraction and reinjection of fluids on the reservoir was evaluated for 60 years of the plant activity. The results are fundamental to develop a sustainable geothermal heat plant and represent a real case study for the exploitation of similar carbonate reservoir geothermal resources.
Plug-in Electric Vehicles for Grid Services Provision: Proposing an Operational Characterization Procedure for V2G Systems
Authors: Casaleiro Ângelo , Amaro e Silva Rodrigo , Serra João
Published: March 2020

Plug-in electric vehicles (PEVs) are expected to play a role as power grid ancillary service providers through vehicle-to-grid (V2G) chargers, enabling higher levels of renewable electricity penetration. However, to fully exploit the storage capacity of PEVs and fast responsiveness, it is crucial to understand their operational characteristics. This work proposes a characterization procedure for V2G systems providing grid services. It extends the existing literature on response time, AC/DC conversion and reactive power assessment. Illustrative results were obtained by implementing the procedure using a Nissan Leaf battery electric vehicle (BEV) connected to a remotely operated commercial V2G CHAdeMO charger. The V2G system was characterized as having a relative inaccuracy and variability of response inferior to 3% and 0.4%, respectively. Its average communication and ramping times are 2.37 s and 0.26 s/kW, respectively. Its conversion efficiency and power factor both showed degradation in the power values below 50% of the charger’s nominal power. Moreover, the proposed visualizations revealed that: i) the V2G system implements power requests for the DC power flow; ii) the power factor control algorithm was nonoperational; and iii) the acquired data can leverage statistical models that describe the operation of V2G systems (which is of extreme value for researchers and operators).
Multiplexed Supply of a MISO Wireless Power Transfer System for Battery-Free Wireless Sensors
Authors: Bouattour Ghada , Elhawy Mohamed , Naifar Slim , Viehweger Christian , Ben Jmaa Derbel Houda , Kanoun Olfa
Published: March 2020

Multi-input single output wireless power transmission (MISO-WPT) systems have decisive advantages concerning flexible receiver position in comparison to single coil systems. However, the supply of the primary side brings a large uncertainty in case of variable positions of the secondary side. In this paper, a compact multiplexed primary side electronic circuit is proposed, which includes only one signal generator, a passive peak detector, a communication module, and a compensation capacitor. The novel approach has been studied and evaluated for a MISO-WPT system having a 16 coils on primary side and one coil on secondary side having the double diameter. Results show that a standard microcontroller, in this case an STM32, is sufficient for the control of the whole system, so that the costs and the energy consumption are significantly reduced. An activation strategy has been proposed, which allows to determine the optimal transmitting coil for each position of the receiving coil and to switch it on. The time-to-start-charging at different positions of the receiving coil and different number of neighbors has been determined. It remains in all cases under 2.5 s.
Electrodialytic Energy Storage System: Permselectivity, Stack Measurements and Life-Cycle Analysis
Authors: Krakhella Kjersti Wergeland , Morales Marjorie , Bock Robert , Seland Frode , Burheim Odne Stokke , Einarsrud Kristian Etienne
Published: March 2020

Reverse electrodialysis and electrodialysis can be combined into a closed energy storage system, allowing for storing surplus energy through a salinity difference between two solutions. A closed system benefits from simple temperature control, the ability to use higher salt concentrations and mitigation of membrane fouling. In this work, the permselectivity of two membranes from Fumatech, FAS-50 and FKS-50, is found to be ranging from 0.7 to 0.5 and from 0.8 to 0.7 respectively. The maximum unit cell open-circuit voltage was measured to be 115 ± 9 mV and 118 ± 8 mV at 25 ° C and 40 ° C, respectively, and the power density was found to be 1.5 ± 0.2 W m uc − 2 at 25 ° C and 2.0 ± 0.3 W m uc − 2 at 40 ° C. Given a lifetime of 10 years, three hours of operation per day and 3% downtime, the membrane price can be 2.5 ± 0.3 $ m − 2 and 1.4 ± 0.2 $ m − 2 to match the energy price in the EU and the USA, respectively. A life-cycle analysis was conducted for a storage capacity of 1 GWh and 2 h of discharging. The global warming impact is 4.53 · 10 5 kg CO2 equivalents/MWh and the cumulative energy demand is 1.61 · 10 3 MWh/MWh, which are 30% and 2 times higher than a lithium-ion battery pack with equivalent capacity, respectively. An electrodialytic energy storage system reaches a comparable global warming impact and a lower cumulative energy demand than a lithium-ion battery for an average life span of 20 and 3 years, respectively.
Power System Nonlinear Modal Analysis Using Computationally Reduced Normal Form Method
Authors: Ugwuanyi Nnaemeka Sunday , Kestelyn Xavier , Marinescu Bogdan , Thomas Olivier
Published: March 2020

Increasing nonlinearity in today’s grid challenges the conventional small-signal (modal) analysis (SSA) tools. For instance, the interactions among modes, which are not captured by SSA, may play significant roles in a stressed power system. Consequently, alternative nonlinear modal analysis tools, notably Normal Form (NF) and Modal Series (MS) methods are being explored. However, they are computation-intensive due to numerous polynomial coefficients required. This paper proposes a fast NF technique for power system modal interaction investigation, which uses characteristics of system modes to carefully select relevant terms to be considered in the analysis. The Coefficients related to these terms are selectively computed and the resulting approximate model is computationally reduced compared to the one in which all the coefficients are computed. This leads to a very rapid nonlinear modal analysis of the power systems. The reduced model is used to study interactions of modes in a two-area power system where the tested scenarios give same results as the full model, with about 70% reduction in computation time.
Disturbance Observer-Based Prescribed Performance Fault-Tolerant Control for a Multi-Area Interconnected Power System with a Hybrid Energy Storage System
Authors: Yu Dong , Zhang Weiming , Li Jianlin , Yang Weilin , Xu Dezhi
Published: March 2020

The goal of this study is to develop a disturbance observer-based prescribed performance fault-tolerant controller (PPFTC) for a multi-area interconnected power system (MIPS) with a hybrid energy storage system (HESS). The mathematical model of the MIPS with HESS is introduced first. Then the load disturbance estimation is obtained using a disturbance observer (DO) approach. By introducing two additional functions, the tracking error is bounded to achieve the desired response. The PPFTC is further developed based on the DO ensuring that the area control error (ACE) of the MIPS asymptotically converges to zero. Finally, the effectiveness of the given PPFTC and DO are inspected through the use of the Lyapunov theory and simulated results.
Road Test-Based Electric Bus Selection: A Case Study of the Nanjing Bus Company
Authors: Gong Jian , He Jie , Cheng Cheng , King Mark , Yan Xintong , He Zhixia , Zhang Hao
Published: March 2020

Globally, the use of electric vehicles, and in particular the use of electric buses, has been increasing. The city of Nanjing leads China in the adoption of electric buses, supported by city policies and infrastructure. To lower costs and provide a better service, vehicle selection is crucial, however, existing selection methods are limited. Accordingly, Nanjing Bus Company developed a test method based on road tests to select a bus. This paper presents a detailed description of the test method and a case study of its application. The method included an organization structure, selection of eight test vehicles (four 10 m length, four 8 m length) from four brands (a total of 32 test vehicles), selection of indicators and selection of routes. Data was collected from repeated drives by 65 drivers over an 8-week period. Indicators included power consumption, charging duration, failure duration and driving distance. It is concluded that the road test method designed and conducted by the Nanjing Bus Company provides a good framework for the selection of pure electric buses. Furthermore, subsequent experience with selected buses supports the validity and value of the model.
Stochastic Optimization of Microgrid Participating Day-Ahead Market Operation Strategy with Consideration of Energy Storage System and Demand Response
Authors: Zhao Huiru , Lu Hao , Li Bingkang , Wang Xuejie , Zhang Shiying , Wang Yuwei
Published: March 2020

More and more attention has been paid to the development of renewable energy in the world. Microgrids with flexible regulation abilities provide an effective way to solve the problem of renewable energy connected to power grids. In this article, an optimization strategy of a microgrid participating in day-ahead market operations considering demand responses is proposed, where the uncertainties of distributed renewable energy generation, electrical load, and day-ahead market prices are taken into account. The results show that, when the microgrid implements the demand response, the operation cost of the microgrid decreases by 4.17%. Meanwhile, the demand response program can transfer the peak load of the high-price period to the low-price period, which reduces the peak valley difference of the load and stabilizes the load curve. Finally, a sensitivity analysis of three factors is carried out, finding that, with the increase of the demand response adjustable ratio or the maximum capacity of the electrical storage devices, the operation cost of the microgrid decreases, while, with the increase of the demand response cost, the operation cost of the microgrid increases and, finally, tends to the cost without the demand response. The sensitivity analysis reveals that the demand response cost has a reasonable pricing range to maximize the value of the demand response.
Optimization Design of an Axial Split-Phase Bearingless Flywheel Machine with Magnetic Sleeve and Pole-Shoe Tooth by RSM and DE Algorithm
Authors: Zhu Zhiying , Zhu Jin , Zhu Hailang , Zhu Xi , Yu Yajie
Published: March 2020

In order to improve the suspension and torque performance of a bearingless flywheel machine, a new type of axial split-phase bearingless flywheel machine with a magnetic sleeve and pole-shoe tooth is analyzed and optimized as described in this paper. Based on the basic structure and working characteristics of the machine, the response surface methodology (RSM) and differential evolution (DE) algorithm are adopted to further optimize the parameters of the stator teeth of the machine to improve the radial space utilization and motor output performance. Firstly, the Box–Behnken design (BBD) and finite element analysis (FEA) are combined to select the representative optimization parameter combinations to establish the sample data space, and the response surface models of machine torque and suspension force are established using the least square method. Besides this, the DE algorithm is employed to obtain the optimal tooth profile parameter configuration for the multi-objective optimization of machine performance. Finally, the output performances of the machine before and after optimization are compared under initial and optimized winding turns. The results show that, compared with the initial structure, the average torque and suspension force of the optimized machine increase by 36.46 % and 108.22% respectively, which demonstrates the effectiveness of the tooth profile optimization method. At the same time, an experimental prototype is also produced, laying the experimental foundation for further practical exploration.
Phase Synchronization Stability of Non-Homogeneous Low-Voltage Distribution Networks with Large-Scale Distributed Generations
Authors: Chen Shi , Zhou Hong , Lai Jingang , Zhou Yiwei , Yu Chang
Published: March 2020

The ideal distributed network composed of distributed generations (DGs) has unweighted and undirected interactions which omit the impact of the power grid structure and actual demand. Apparently, the coupling relationship between DGs, which is determined by line impedance, node voltage, and droop coefficient, is generally non-homogeneous. Motivated by this, this paper investigates the phase synchronization of an islanded network with large-scale DGs in a non-homogeneous condition. Furthermore, we explicitly deduce the critical coupling strength formula for different weighting cases via the synchronization condition. On this basis, three cases of Gaussian distribution, power-law distribution, and frequency-weighted distribution are analyzed. A synthetical analysis is also presented, which helps to identify the order parameter. Finally, this paper employs the numerical simulation methods to test the effectiveness of the critical coupling strength formula and the superiority over the power-law distribution.
The Nexus Between Electricity Consumption, Economic Growth, and CO2 Emission: An Asymmetric Analysis Using Nonlinear ARDL and Nonparametric Causality Approach
Authors: Chukwunonso Bosah Philip , Li Shixiang , Kwaku Minua Ampofo Gideon , Akwasi Asante Daniel , Wang Zhanqi
Published: March 2020

This article examines the asymmetric relationship between electric consumption, economic growth, and carbon dioxide emission in 15 countries over the period 1971–2014. We employed a nonlinear auto-regressive distribution Lag (NARDL) model approach to investigate the asymmetric cointegration between variables. Additionally, we applied the asymmetric causality approach to determine the causal relationship between variables. Results confirm nonlinear cointegration between variables in Cameroon, Congo Republic, Zambia, Canada, and the UK. The Wald test results confirm a long-run asymmetric link between electricity consumption, economic growth, and carbon emission in Canada and Cameroon, while a short-run asymmetric effect in the Congo Republic and the UK. Findings from the granger causality test are volatile across variables. The result provides strong support for the symmetric relationship between electric consumption, economic growth, and carbon emission in the short and long run. This study provides new evidence for policymakers to formulate country-specific policies to obtain better environmental quality while achieving sustainable economic growth.
North American Hardwoods Identification Using Machine-Learning
Authors: Verly Lopes Dercilio Junior , Burgreen Greg W. , Entsminger Edward D.
Published: March 2020

This technical note determines the feasibility of using an InceptionV4_ResNetV2 convolutional neural network (CNN) to correctly identify hardwood species from macroscopic images. The method is composed of a commodity smartphone fitted with a 14× macro lens for photography. The end-grains of ten different North American hardwood species were photographed to create a dataset of 1869 images. The stratified 5-fold cross-validation machine-learning method was used, in which the number of testing samples varied from 341 to 342. Data augmentation was performed on-the-fly for each training set by rotating, zooming, and flipping images. It was found that the CNN could correctly identify hardwood species based on macroscopic images of its end-grain with an adjusted accuracy of 92.60%. With the current growing of machine-learning field, this model can then be readily deployed in a mobile application for field wood identification.
Site Index Models for Main Forest-Forming Tree Species in Poland
Authors: Socha Jarosław , Tymińska-Czabańska Luiza , Grabska Ewa , Orzeł Stanisław
Published: March 2020

Site index is the most commonly used measure of potential site productivity, providing key information for forest management practices. It is determined using species-specific site index models that take into account climatic and edaphic factors. To reliably estimate the site index, appropriate models are necessary. In Poland, however, outdated guidelines, i.e., yield tables, are used to determine site classes, which result in the inappropriate estimation of height growth and increments of stands. Therefore, the aim of this study is to develop new site index models for the main forest forming tree species in Poland, in a total of eight species. For the development of site index models, we used growth trajectories of 3052 sample trees, representing the whole range of geographic locations and site conditions. Five dynamic models were selected and parametrized to develop the site index models. The models were evaluated using quantitative measures of goodness of fit (MAE, R2, and AIC), the analysis of residuals, and the assessment of how the model reflects the biological phenomena of height growth. Results showed that depending on the species, different models have the highest predictive ability. There are significant differences in results using traditional yield tables and developed site index models. For most of the species, the largest differences characterized either the youngest or the oldest age classes. These differences can be attributed to the changes in growth conditions from the time when yield tables were developed. Growth dynamics of forest stands may also show spatial variability, thus, in future research additional site variables and, regional variability should be taken into account.
Genome-Wide Identification of the VQ Protein Gene Family of Tobacco (Nicotiana tabacum L.) and Analysis of Its Expression in Response to Phytohormones and Abiotic and Biotic Stresses
Authors: Liu Cuihua , Liu Hai , Zhou Changyong , Timko Michael P.
Published: March 2020

VQ motif-containing proteins (VQ proteins) are transcriptional regulators that work independently or in combination with other transcription factors (TFs) to control plant growth and development and responses to biotic and abiotic stresses. VQ proteins contain a conserved FxxhVQxhTG amino acid motif that is the main element of its interaction with WRKY TFs. We identified 59 members of the tobacco (Nicotiana tabacum L.) NtVQ gene family by in silico analysis and examined their differential expression in response to phytohormonal treatments and following exposure to biotic and abiotic stressors. NtVQ proteins clustered into eight groups based upon their amino acid sequence and presence of various conserved domains. Groups II, IV, V, VI, and VIII contained the largest proportion of NtVQ gene family members differentially expressed in response to one or more phytohormone, and NtVQ proteins with similar domain structures had similar patterns of response to different phytohormones. NtVQ genes differentially expressed in response to temperature alterations and mechanical wounding were also identified. Over half of the NtVQ genes were significantly induced in response to Ralstonia solanacearum infection. This first comprehensive characterization of the NtVQ genes in tobacco lays the foundation for further studies of the NtVQ-mediated regulatory network in plant growth, developmental, and stress-related processes.
Spatial Variability of Health Inequalities of Older People in China and Related Health Factors
Authors: Yang Mengqi , Rosenberg Mark W. , Li Jie
Published: March 2020

China is facing serious population aging issues because of many unintended consequences of the economic reforms that began in the 1980s and with social policies such as the “one child” policy. Understanding the spatial distribution of the health status of older people has attracted more and more attention in many countries, including China. By employing descriptive analysis, this study uses data from the Chinese Population Censusand Statistical Year Bookto explore the health inequalities of older people at the national level. Based on the Getis-Ord Gi*, this study finds that the uneven spatial distribution of socio-economic status results in health inequalities for older people at the national level. The geographic distribution of life expectancy was correlated with a number of important demographic, socio-economic, and environmental variables. For further research, investigations should be conducted among individuals at micro-geographic scales.
Neutrophil-To-Lymphocyte and Platelet-To-Lymphocyte Ratios as Prognostic Markers of Survival in Patients with Head and Neck Tumours—Results of a Retrospective Multicentric Study
Authors: Szilasi Zsuzsanna , Jósa Valéria , Zrubka Zsombor , Mezei Tünde , Vass Tamás , Merkel Keresztély , Helfferich Frigyes , Baranyai Zsolt
Published: March 2020

Background: The neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) may be useful for drawing conclusions about the survival of head and neck squamous cell carcinoma (HNSCC) patients. Methods: Clinical data of 156 patients managed for HNSCC at two head and neck surgery centres were analyzed retrospectively. We studied the relationships between survival and PLR as well as NLR. Results: With regards to 5-year survival, the difference between the two groups with PLR values lower or higher than the threshold was statistically significant (p = 0.004), and we found the same for disease-free survival (p = 0.05), and tumour-specific mortality (p = 0.009). Concerning NLR, the difference in tumour-specific survival was statistically significant (p = 0.006). According to the multivariate analysis, NLR values higher than the threshold indicated an enhanced risk for overall as well as for tumour-specific mortality. Conclusion: In HNSCC patients, a high NLR may be considered as an independent risk factor for 5-year overall survival.
Maternal Exposure to Ambient Air Pollution and Risk of Preeclampsia: A Population-Based Cohort Study in Scania, Sweden
Authors: Mandakh Yumjirmaa , Rittner Ralf , Flanagan Erin , Oudin Anna , Isaxon Christina , Familari Mary , Hansson Stefan Rocco , Malmqvist Ebba
Published: March 2020

The aim of this study was to investigate the risk of developing preeclampsia (PE) associated with gestational exposure to ambient air pollutants in southern Sweden, a low-exposure area. We used a cohort of 43,688 singleton pregnancies and monthly mean exposure levels of black carbon (BC), local and total particulate matter (PM2.5 and PM10), and NOX at the maternal residential address estimated by Gaussian dispersion modeling from 2000 to 2009. Analyses were conducted using binary logistic regression. A subtype analysis for small-for-gestational age (SGA) was performed. All analyses were adjusted for obstetrical risk factors and socioeconomic predictors. There were 1286 (2.9%) PE cases in the analysis. An adjusted odds ratio (AOR) of 1.35 with a 95% confidence interval (CI) of 1.11–1.63 was found when comparing the lowest quartile of BC exposure to the highest quartile in the third trimester The AOR for PE associated with each 5 µg/m3 increase in locally emitted PM2.5 was 2.74 (95% CI: 1.68, 4.47) in the entire pregnancy. Similar patterns were observed for each 5 µg/m3 increment in locally emitted PM10. In pregnancies complicated by PE with SGA, the corresponding AOR for linear increases in BC was 3.48 (95% CI: 1.67, 7.27). In this low-level setting, maternal exposure to ambient air pollution during gestation was associated with the risk of developing PE. The associations seemed more pronounced in pregnancies with SGA complications, a finding that should be investigated further.
A Cohort Study of Exposure to Antihyperglycemic Therapy and Survival in Patients with Lung Cancer
Authors: Danila Edvardas , Linkevičiūtė-Ulinskienė Donata , Zablockis Rolandas , Gruslys Vygantas , Cicėnas Saulius , Smailytė Giedrė
Published: March 2020

We evaluated the effect of antihyperglycemic therapy on the survival of patients with lung cancer (LC). The analysis included patients with LC and concomitant type 2 diabetes. 15,929 patients were classified into five groups: metformin users, insulin users, metformin and insulin users, sulphonylurea users and non-diabetic group. A multivariate analysis showed that exposure to either metformin or to insulin was associated with a lower risk of LC-specific mortality, and this approached statistical significance (HR 0.82, 95% CI 0.72–92 for metformin and HR 0.65, 95% CI 0.44–95 for insulin). When deaths from all causes were considered, only metformin exposure was associated with a significantly lower risk of death (HR 0.82, 95% CI 0.73–0.92). Users of sulphonylurea were at a higher risk of LC-specific and overall mortality (HRs 1.19, 95% CI 0.99–1.43 and 1.22, 95% CI 1.03–1.45). Our study shows a positive effect of metformin on the survival of patients with LC. Moreover, our results show that exposure to insulin was associated with a lower risk of LC-specific mortality, but not with deaths from all causes. The study results suggested that users of sulphonylurea may be at a higher risk of LC-specific and overall mortality.
Quality of Vermicompost and Microbial Community Diversity Affected by the Contrasting Temperature during Vermicomposting of Dewatered Sludge
Authors: Zhang Hongwei , Li Jianhui , Zhang Yingying , Huang Kui
Published: March 2020

This study aimed to investigate the effects of temperature on the quality of vermicompost and microbial profiles of dewatered sludge during vermicomposting. To do this, fresh sludge was separately vermicomposted with the earthworm Eisenia fetida under different temperature regimes, specifically, 15 °C, 20 °C, and 25 °C. The results showed that the growth rate of earthworms increased with temperature. Moreover, the lowest organic matter content along with the highest electrical conductivity, ammonia, and nitrate content in sludge were recorded for 25 °C indicating that increasing temperature significantly accelerated decomposition, mineralization, and nitrification. In addition, higher temperature significantly enhanced microbial activity in the first 30 days of vermicomposting, also exhibiting the fastest stabilization at 25 °C. High throughput sequencing results further revealed that the alpha diversity of the bacterial community was enhanced with increasing temperature resulting in distinct bacterial genera in each vermicompost. This study suggests that quality of vermicompost and dominant bacterial community are strongly influenced by the contrasting temperature during vermicomposting of sludge, with the optimal performance at 25 °C.
The Roles of Individual and Psychosocial Factors in Predicting Quality of Life Among Working Women in Shanghai
Authors: Xiao Yi , Zhang Tao , Gu Xiangli , Lee Joonyoung , Wang Hongying
Published: March 2020

Working women are at a high risk of suffering from occupational stress and burnout, which can result in reducing Quality of Life (QoL). Guided by the QoL construct and Luban et al.’s conceptual framework, this study aimed to (a) investigate the roles of individual factors (i.e., age) and psychosocial factors (i.e., occupational stress, burnout) on QoL among working women, and (b) examine the age differences among study variables (young versus middle-aged groups). Participants were 375 working women (Mage = 42.06) recruited in Shanghai, China. They completed previously validated questionnaires assessing their occupational stress, burnout (emotional exhaustion, cynicism, and reduced professional efficacy), and QoL (physical health, psychological health, social relationship, and living environment). Confirmatory factor analysis, Pearson product-moment correlation, hierarchical regressions, and factorial multivariate analyses of variance (MANOVA) were used to examine the relationships and differences between occupational stress, burnout, and QoL among working women. Correlation and regression analyses indicated that occupational stress and burnout were significantly associated with QoL among these participants. Two one-factor MANOVAs demonstrated that young-aged working women had higher occupational stress and burnout, but lower levels of QoL than middle-aged women. These results suggest that adopting specific coping strategies to reduce or prevent occupational stress and burnout are needed to improve QoL among working women.
Is Raising Your Grandchild Bad for Your Health? The Association Between Custodial Grandparent Status and Health Biomarkers in Taiwanese Grandparents
Authors: Fokakis Zoe , Nadorff Danielle , McKay Ian
Published: March 2020

Data from two waves of the Social Environment and Biomarkers of Aging Study in Taiwan were analyzed to determine the effects of custodial grandparenting on health in a longitudinal sample. Self-reported measures on respondents’ perception of their health, six health biomarkers, the presence of twelve diseases, and a measure of stress were included. Custodial Grandparents (CGPs) were significantly more likely to report worse health than their peers. However, there were no significant differences in biomarkers, and CGPs were only significantly different from non-custodial grandparents (nCGPs) regarding lower respiratory disease. Results suggest that CGPs do not have significantly worse health than nCGPs, but report feeling less healthy. This disparity is suspected to be due to energy levels or stress sources not assessed by the variables in the original study. These results and their implications based upon the stress-coping model elucidate the need to design interventions that incorporate the East Asian cultural values and practices in order to promote better health outcomes for CGP populations overall.
Effects of Neuromuscular Training on Motor Competence and Physical Performance in Young Female Volleyball Players
Authors: Trajković Nebojša , Bogataj Špela
Published: March 2020

Although neuromuscular training (NMT) emphasizes injury prevention training, there is little information about its effects on performance in young athletes. This study aimed to investigate the effects of eight-weeks NMT on motor competence and physical performance in 10- to 12-year-old female volleyball players. Sixty-six participants (mean ± SD; 11.05 ± 0.72 years) were randomized into either the NMT group (NTG; n = 32) or control group (CON; n = 34). Sprint on 10-m, modified T-test, plank, vertical jump, and medicine ball throw tests were used to assess the physical performance. The Körperkoordinationstest für Kinder (KTK) was used to assess the subjects’ motor competence. The NMT was performed twice a week during the first 30 min of each regularly scheduled 90-minute volleyball training. Participants in the CON group attended only their regular volleyball training. A significant group x time interaction was found for Motor Quotient KTK (MQKTK) (p < 0.001), KTK lateral jumps (p < 0.001), and KTK shifting platforms (p < 0.01). There was a significant interaction for modified T-test results (p < 0.001) and vertical jump (p = 0.04). No change was observed in both groups for plank performance (p > 0.05). The NMT promoted significant gains in motor competence and physical performance in youth female volleyball players.
The Level and Development of Unemployment before Disability Retirement: A Retrospective Study of Finnish Disability Retirees and Their Controls
Authors: Laaksonen Mikko , Blomgren Jenni
Published: March 2020

A weakening work ability may lead to a higher risk of gradual exclusion from working life, which may be manifested in increasing levels of unemployment. This study examined development of unemployment prior to disability retirement by educational level and occupational class in different diagnostic groups. The study population comprised 70% of Finnish residents aged 25–64 years who retired due to disability in 2011–2015 (n = 54,387). Growth curve models were used to analyze the level and development of pre-retirement unemployment among the retirees due to mental disorders, musculoskeletal diseases and all other somatic diseases and their gender- and age-matched controls drawn from the non-retired population. During six pre-retirement years, disability retirees had on average 39 annual excess unemployment days compared to their non-retiring controls. Excess unemployment was particularly high among those retiring due to mental disorders. On average, unemployment increased by 5.5 days per each year of approaching disability retirement, after controlling for aging and secular trends. The increase was largest among those who retired due to mental disorders. Excess unemployment was higher among the less educated and among manual workers, in particular among those retiring due to mental disorders or somatic diseases other than musculoskeletal diseases. Increased efforts to maintain and improve work ability among the unemployed is crucial in diminishing disability retirement at the population level. As the level of unemployment is elevated already several years before disability retirement, work ability problems among the unemployed should be tackled in the early stages.
Comparison of Azithromycin Removal from Water Using UV Radiation, Fe (VI) Oxidation Process and ZnO Nanoparticles
Authors: Talaiekhozani Amirreza , Joudaki Sahar , Banisharif Farhad , Eskandari Zeinab , Cho Jinwoo , Moghadam Ghasem , Rezania Shahabaldin
Published: March 2020

Antibiotics are resistant to biodegradation, and their removal by biological processes is difficult. The purpose of this study was to investigate the removal of azithromycin from water using ultraviolet radiation (UV), Fe (VI) oxidation process and ZnO nanoparticles. The effect of different parameters such as pH, temperature, hydraulic retention time (HRT), the concentration of Fe (VI) and ZnO nanoparticles and UV intensity on the removal of azithromycin from water was investigated. The optimal conditions for the removal of azithromycin were a pH of 2, a temperature of 25 °C, a HRT of 15 min, and a ratio of ZnO nanoparticles to the initial concentration of azithromycin (A/P) of 0.00009 which was fitted by Langmuir isotherm. In addition, the optimal conditions for the removal of azithromycin using UV radiation were a pH of 7, a temperature of 65 °C, a HRT of 60 min, and UV radiation power of 163 mW/cm2. For the Fe (VI) oxidation process, the optimal conditions were a pH of 2, a temperature of 50 °C and a HRT of 20 min. Also, the optimal ratio of Fe (VI) to the initial concentration of antibiotic was between 0.011 and 0.012. The results of this study showed that the Fe (VI) oxidation process, UV radiation, and ZnO nanoparticles were efficient methods for the removal of azithromycin from water.
Identifying Driving Forces of Built-Up Land Expansion Based on the Geographical Detector: A Case Study of Pearl River Delta Urban Agglomeration
Authors: Liu Yongwei , Cao Xiaoshu , Li Tao
Published: March 2020

Understanding the driving forces behind built-up land expansion is crucial in urban planning and management. Using the Pearl River Delta urban agglomeration as research area, four landscape metrics were used to analyze landscape characteristics of urban expansion from 1990 to 2015. Spatial autocorrelation analysis was used to study the characteristics of built-up land expansion, while geographical detector was employed to identify the driving forces of urban land growth and their interactions. The results show the extent of built-up land has been increasing, the structure has become more complex, the level of fragmentation has been increasing, and the aggregation degree is in decline. The built-up landscape index shows spatial heterogeneity occurring in the core and peripheral towns of cities, as well as in the core and peripheral areas of the entire region. Also, changes in the built-up landscape index indicate increased spatial aggregation occurring in the past 25 years. Results from the geographical detector show natural, socio-economic, and transportation-related factors have substantial influence on built-up land expansion. Elevation, slope, population density, change in population density, and road network density were shown to have high influencing power. The influencing powers of slope and change in population density were also found to be different from other factors, highlighting their important role in urban development. Also, there were two types of interactions found, enhance nonlinear and enhance bivariate interactions, indicating the compounding influence of interactions between significant determinants. This study provides a new perspective and methodological approach in evaluating the driving forces behind built-up land expansion and their interactions.
Relationship of Salivary Microbiome with the Worsening of the Periodontal Health Status in Young Adults: A 3-Year Cohort Study
Authors: Islam Md Monirul , Ekuni Daisuke , Toyama Naoki , Kobayashi Terumasa , Fujimori Kohei , Uchida Yoko , Fukuhara Daiki , Taniguchi-Tabata Ayano , Kataoka Kota , Iwasaki Yoshiaki , Morita Manabu
Published: March 2020

The purpose of this prospective cohort study was to investigate the influence of the salivary microbiome on the worsening of the periodontal health status among Japanese young adults. We assessed the data of systemically healthy and non-smoking young (18–22 years) university students (n = 457) from Okayama University at baseline (2013) and follow-up (2016). The worsening group was defined based on an increase in the percentage of bleeding on probing (%BOP) or an increase in probing pocket depth (PPD) from <4 mm to ≥4 mm. Unstimulated saliva samples were randomly collected from 69 students for microbiome analysis at follow-up. The salivary microbiome was assessed through 16S rRNA metagenomic sequencing. The type of community in the salivary microbiome clustered by statistical analysis and diversity was not significantly associated with the worsening of the periodontal health status in cases of increasing %BOP and PPD (p > 0.05). The prevalence of some species was significantly higher in the worsening group than in the non-worsening group (p < 0.05) in both cases. The worsening of the periodontal health status was associated with some species, but not the type of community and diversity in the salivary microbiome among Japanese young adults.
Concentrations, Possible Sources and Health Risk of Heavy Metals in Multi-Media Environment of the Songhua River, China
Authors: Li Kunyang , Cui Song , Zhang Fuxiang , Hough Rupert , Fu Qiang , Zhang Zulin , Gao Shang , An Lihui
Published: March 2020

Heavy metal pollution in the river environment has been a source of widespread interest due to potential threats to human health and ecosystem security. Many studies have looked at heavy metal pollution in the context of single source-pathway-receptor relationships, however few have sought to understand pollution from a more wholistic multi-media perspective. To investigate potential risks in a more wholistic way, concentrations of six heavy metals (Cd, Cr, Ni, Cu, Zn and Pb) were detected in multi-media (water, sediment and riparian soil) collected from 14 sampling sites in the main stream of the Songhua River. Chemical analyses indicated that the average concentration of heavy metals in water followed: Zn > Cr > Cu > Pb > Ni > Cd, with a different trend observed in sediments and riparian soil: Zn > Cr > Ni > Pb > Cu > Cd. The potential risk was evaluated using the heavy metal pollution index (HPI), Nemerow pollution index (PN), hazard index (HI) and carcinogenic risk (CR) metrics. Results showed that all HPI values were lower than the critical level of 100 indicating that the levels of these targeted heavy metals were within drinking water safety limits. The PN indicated that both sediment (2.64) and soil (2.95) could be considered “moderately polluted”, with Cd and Zn providing the most significant contributions. A human health risk assessment suggested that the non-carcinogenic risks were within acceptable levels (HI < 1), as was the cancer risk associated with dermal adsorption (CR <10−6). However, the CR associated with ingestion exposure (4.58 × 10−6) exceeded the cancer risk threshold (10−6) indicative of elevated cancer incidence in exposed populations. Health-risk estimates were primarily associated with Cd in the Songhua River. Source apportionment was informed by Pearson correlation analysis coupled with principal component analysis (PCA) which indicated that Cu was mainly derived from natural (geogenic) sources; Cr and Ni were associated with industrial emissions; Pb might be derived from agricultural and transportation sources; Zn might be from industrial, agricultural activities and transportation; while Cd is likely from industrial and agricultural emissions. The source apportionment information could provide the basis for a risk-management strategy focused on reducing Cd and Zn emissions to the riverine environment. Results from this study will provide the scientific knowledge that is needed for measuring and controlling heavy metals sources and pollution characteristics, and identifying the potential cancer risk with different exposure pathways, as well as making effective environmental management policies at catchment or regional scales.
A 15 Year Evaluation of West Nile Virus in Wisconsin: Effects on Wildlife and Human Health
Authors: Uelmen Johnny A. , Brokopp Charles , Patz Jonathan
Published: March 2020

West Nile virus (WNV) is the most important and widespread mosquito-borne virus in the United States (U.S.). WNV has the ability to spread rapidly and effectively, infecting more than 320 bird and mammalian species. An examination of environmental conditions and the health of keystone species may help predict the susceptibility of various habitats to WNV and reveal key risk factors, annual trends, and vulnerable regions. Since 2002, WNV outbreaks in Wisconsin varied by species, place, and time, significantly affected by unique climatic, environmental, and geographical factors. During a 15 year period, WNV was detected in 71 of 72 counties, resulting in 239 human and 1397 wildlife cases. Controlling for population and sampling efforts in Wisconsin, rates of WNV are highest in the western and northwestern rural regions of the state. WNV incidence rates were highest in counties with low human population densities, predominantly wetland, and at elevations greater than 1000 feet. Resources for surveillance, prevention, and detection of WNV were lowest in rural counties, likely resulting in underestimation of cases. Overall, increasing mean temperature and decreasing precipitation showed positive influence on WNV transmission in Wisconsin. This study incorporates the first statewide assessment of WNV in Wisconsin.
LY75 Ablation Mediates Mesenchymal-Epithelial Transition (MET) in Epithelial Ovarian Cancer (EOC) Cells Associated with DNA Methylation Alterations and Suppression of the Wnt/β-Catenin Pathway
Authors: Mehdi Sadia , Bachvarova Magdalena , Scott-Boyer Marie-Pier , Droit Arnaud , Bachvarov Dimcho
Published: March 2020

Growing evidence demonstrates that epithelial–mesenchymal transition (EMT) plays an important role in epithelial ovarian cancer (EOC) progression and spreading; however, its molecular mechanisms remain poorly defined. We have previously shown that the antigen receptor LY75 can modulate EOC cell phenotype and metastatic potential, as LY75 depletion directed mesenchymal–epithelial transition (MET) in EOC cell lines with mesenchymal phenotype. We used the LY75-mediated modulation of EMT as a model to investigate for DNA methylation changes during EMT in EOC cells, by applying the reduced representation bisulfite sequencing (RRBS) methodology. Numerous genes have displayed EMT-related DNA methylation patterns alterations in their promoter/exon regions. Ten selected genes, whose DNA methylation alterations were further confirmed by alternative methods, were further identified, some of which could represent new EOC biomarkers/therapeutic targets. Moreover, our methylation data were strongly indicative for the predominant implication of the Wnt/β-catenin pathway in the EMT-induced DNA methylation variations in EOC cells. Consecutive experiments, including alterations in the Wnt/β-catenin pathway activity in EOC cells with a specific inhibitor and the identification of LY75-interacting partners by a proteomic approach, were strongly indicative for the direct implication of the LY75 receptor in modulating the Wnt/β-catenin signaling in EOC cells.