bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Iodine Doping on Carrier Behavior at the Interface of Perovskite Crystals: Efficiency and Stability
Authors: Liu Guilin , Liu Lang , Niu Xiuxiu , Zhou Huanping , Chen Qi
Published: April 2018

The interface related to the polycrystalline hybrid perovskite thin film plays an essential role in the resulting device performance. Iodine was employed as an additive to modify the interface between perovskite and spiro-OMeTAD hole transport layer. The oxidation ability of iodine significantly improved the efficiency of charge extraction for perovskite solar cells. It reveals that the Open Circuit Voltage (Voc) and Fill Factor (FF) of perovskite solar cells were improved substantially due to the dopant, which is mainly attributed to the interfacial improvement. It was found that the best efficiency of the devices was achieved when the dopant of iodine was in equivalent mole concentration with that of spiro-OMeTAD. Moreover, the long-term stability of the corresponding device was investigated.
Parametric Study of the Behavior of Longitudinally and Transversally Prestressed Concrete under Pure Torsion
Authors: Bernardo Luís , Andrade Jorge , Teixeira Mafalda
Published: April 2018

Among several analytical models to describe the behavior of reinforced concrete (RC) and longitudinally prestressed concrete (LPC) beams under torsion, the Modified Variable Angle Truss Model (MVATM) is particularly efficient to capture the behavioral states of the member until failure and agree well with experimental results. This article aims to extend the MVATM to cover transversally prestressed concrete (TPC) beams under torsion. The changes in the formulation and calculation procedure of the original VATM, in order to include the influence of transversal prestress, are presented. The extended MAVTM is then used to compute the global response of LPC and TPC beams under torsion with similar total prestress reinforcement ratios, namely the torque–twist curves. The obtained predictions are then compared and discussed. It is shown that for the ultimate loading, transversal prestress constitutes also an effective solution to improve the behavior of the beams under torsion. However, transversal prestress is less effective to delay the cracked state. Finally, it is also shown that when prestress is distributed in both longitudinal and transversal direction, the global response of the beams under torsion is further improved, namely the resistance torque and the torsional stiffness in the cracked state.
Exergy Analyses of Onion Drying by Convection: Influence of Dryer Parameters on Performance
Authors: Castro María , Román Celia , Echegaray Marcelo , Mazza Germán , Rodriguez Rosa
Published: April 2018

This research work is concerned in the exergy analysis of the continuous-convection drying of onion. The influence of temperature and air velocity was studied in terms of exergy parameters. The energy and exergy balances were carried out taking into account the onion drying chamber. Its behavior was analyzed based on exergy efficiency, exergy loss rate, exergetic improvement potential rate, and sustainability index. The exergy loss rates increase with the temperature and air velocity augmentation. Exergy loss rate is influenced by the drying air temperatures and velocities because the overall heat transfer coefficient varies with these operation conditions. On the other hand, the exergy efficiency increases with the air velocity augmentation. This behavior is due to the energy utilization was improved because the most amount of supplied energy was utilized for the moisture evaporation. However, the exergy efficiency decreases with the temperature augmentation due to the free moisture being lower, then, the moisture begins diffusing from the internal structure to the surface. The exergetic improvement potential rate values show that the exergy efficiency of onion drying process can be ameliorated. The sustainability index of the drying chamber varied from 1.9 to 5.1. To reduce the process environmental impact, the parameters must be modified in order to ameliorate the exergy efficiency of the process.
Virtual Network Embedding Based on Graph Entropy
Authors: Zhang Jingjing , Zhao Chenggui , Wu Honggang , Lin Minghui , Duan Ren
Published: April 2018

For embedding virtual networks into a large scale substrate network, a massive amount of time is needed to search the resource space even if the scale of the virtual network is small. The complexity of searching the candidate resource will be reduced if candidates in substrate network can be located in a group of particularly matched areas, in which the resource distribution and communication structure of the substrate network exhibit a maximal similarity with the objective virtual network. This work proposes to discover the optimally suitable resource in a substrate network corresponding to the objective virtual network through comparison of their graph entropies. Aiming for this, the substrate network is divided into substructures referring to the importance of nodes in it, and the entropies of these substructures are calculated. The virtual network will be embedded preferentially into the substructure with the closest entropy if the substrate resource satisfies the demand of the virtual network. The experimental results validate that the efficiency of virtual network embedding can be improved through our proposal. Simultaneously, the quality of embedding has been guaranteed without significant degradation.
Adjusted Empirical Likelihood Method in the Presence of Nuisance Parameters with Application to the Sharpe Ratio
Authors: Fu Yuejiao , Wang Hangjing , Wong Augustine
Published: April 2018

The Sharpe ratio is a widely used risk-adjusted performance measurement in economics and finance. Most of the known statistical inferential methods devoted to the Sharpe ratio are based on the assumption that the data are normally distributed. In this article, without making any distributional assumption on the data, we develop the adjusted empirical likelihood method to obtain inference for a parameter of interest in the presence of nuisance parameters. We show that the log adjusted empirical likelihood ratio statistic is asymptotically distributed as the chi-square distribution. The proposed method is applied to obtain inference for the Sharpe ratio. Simulation results illustrate that the proposed method is comparable to Jobson and Korkie’s method (1981) and outperforms the empirical likelihood method when the data are from a symmetric distribution. In addition, when the data are from a skewed distribution, the proposed method significantly outperforms all other existing methods. A real-data example is analyzed to exemplify the application of the proposed method.
Vacuum Exhaust Process in Pilot-Scale Vacuum Pressure Swing Adsorption for Coal Mine Ventilation Air Methane Enrichment
Authors: Yang Xiong , Liu Yingshu , Li Ziyi , Zhang Chuanzhao , Xing Yi
Published: April 2018

Recovery and treatment of methane from coal mine ventilation air methane (VAM) with cost-effective technologies have been an ongoing challenge due to low methane concentrations. In this study, a type of coconut shell-based active carbon was employed to enrich VAM with a three-bed vacuum pressure swing adsorption unit. A new vacuum exhaust step for the VPSA process was introduced. The results show that the vacuum exhaust step can increase the methane concentration of the product without changing adsorption and desorption pressure. Under laboratory conditions, the concentration of product increased from 0.4% to 0.69% as the vacuum exhaust ratio increased from 0 to 3.1 when the feed gas concentration was 0.2%. A 500 m³/h pilot-scale test system for VAM enrichment was built rendering good correlation with the laboratory results in terms of the vacuum exhaust step. By using a two-stage three-bed separation unit, the VAM was enriched from 0.2% to over 1.2%.
Intrinsic Variability in the Degradation of a Batch of Commercial 18650 Lithium-Ion Cells
Authors: Devie Arnaud , Baure George , Dubarry Matthieu
Published: April 2018

The use of lithium batteries for power and energy-hungry applications has risen drastically in recent years. For such applications, it is necessary to connect the batteries in large assemblies of cells in series and parallel. With a large number of cells operating together, it is necessary to understand their intrinsic variabilities, not only at the initial stage but also upon aging. In this study, we studied a batch of commercial cells to address their initial cell-to-cell variations and also the variations induced by cycling. To do so, we not only tracked several metrics associated with cell performance, the maximum capacity, the resistance, and the rate capability but also the degradation mechanism via a non-invasive quantification of the loss of lithium inventory (LLI), the loss of active material (LAM) and the kinetic degradation on both electrodes. We found that, even with small initial cell-to-cell variations, significant variations will be observed upon aging because the cells degrade at a different pace. We also observed that these variations were not correlated with the initial variations.
An Enhanced Control Scheme Based on New Adaptive Filters for Cascaded NPC/H-Bridge System
Authors: Kang Jin-Wook , Lee Hoon , Hyun Seung-Wook , Kim Jintae , Won Chung-Yuen
Published: April 2018

This paper studies the voltage fluctuation of dc-link generated in a 13-level cascaded neutral point clamped (NPC)/h-bridge (CNHB) with single-phase active front end (AFE) at the input side of each cell. The voltage fluctuation may deteriorate the power factor (PF) and current harmonics in the system. In this paper, new adaptive filters are proposed to overcome the problem. The center frequency of the proposed filters can be automatically varied, which allows to eliminate the specific harmonics in the dc-link well rather than the conventional one. Therefore, it can reduce the fluctuation of dc-link and maintain high PF and low current harmonic distortion without additional circuits externally or the current harmonics injection technique. As a result, capacitance for the dc-link can be optimally designed, and even cost and volume of the system can be reduced. This paper analyzes reasons of increasing voltage fluctuation theoretically and the conventional filter and proposed two types of adaptive filters are compared. In addition, the optimal design method of the dc-link capacitor necessarily used in NPC/h-bridge is presented. To verify the principle and feasibility of the proposed control method, a simulation and experiment are implemented with the CNHB system.
Non-Equal Voltage Cell Balancing for Battery and Super-Capacitor Source Package Management System Using Tapped Inductor Techniques
Authors: Wang Xiaolin , Cheng Ka Wai Eric , Fong Yat Chi
Published: April 2018

The battery management system (BMS) is the key development for energy storage systems, and battery balancing is an important subsystem of the BMS. However, with rapid development of supercapacitors, future energy storage cells are not constrained by one type, while different types of cells may form a source package (SP). Furthermore, the introduction of second-life batteries from retired electric vehicles promotes the demand of effective balancing systems for SPs with hybrid cells, as well as the requirement that balancing should be extended to any preset ratio rather than 1:1. This paper proposes a novel tapped inductor balancing circuit that allows any ratio of voltage balancing for hybrid energy storage cells. The analysis of the circuit, simulation and experiment results are presented to demonstrate its effectiveness in handling hybrid source balancing.
Analysis of Particulate Matter (PM) Emissions in Diesel Engines Using Palm Oil Biodiesel Blended with Diesel Fuel
Authors: Yusop Ahmad Fitri , Mamat Rizalman , Yusaf Talal , Najafi Gholamhassan , Yasin Mohd Hafizil Mat , Khathri Akasyah Mohd
Published: April 2018

This study has focused on the PM emissions of diesel engines. Diesel engines are attractive power units that are used widely in many fields and have become one of the larger contributors of total petroleum consumption. However, diesel engines are among the main contributors of emissions into the air, especially particulate matter (PM) and nitrogen oxides (NOx). PM is one of the major pollutants emitted by diesel engines and has adverse effects on human health. Accordingly, many studies have been conducted to find alternative fuels that are clean and efficient. Biodiesel, which produces less PM than diesel fuel, is preferred as an alternative source for diesel engines. Therefore, using palm oil methyl ester (POME) for diesel engines would be a more economical and sustainable solution. This study has focused on the PM emissions of diesel engines fuelled by a diesel and POME blend (B5, B10, B20, and B100). A comparison between diesel and the POME blend has been made which involves PM mass concentration and its components (soluble organic fraction (SOF) and dry soot (DS)). Combustion characteristics, such as in-cylinder pressure and rate of heat release of the engine, as well as gaseous emissions, have also been observed at different operating engine loads (0.05 MPa 20%, 0.4 MPa 40%, and 0.7 MPa 60%). The results show that PM emissions of B100 are lower than those of diesel fuel owing to the oxygen content of POME. With regard to the SOF concentration, B100 has a higher SOF value than diesel fuel at all engine loads. Meanwhile, the DS for B100 is lower than that of diesel fuel. Moreover, as the engine load increased, PM and SOF concentrations increased, while DS concentration decreased. The observation of in-cylinder pressure showed that the increment of pressure with the increasing POME blend, as well as the increasing engine load due to the high cetane number for B100, led to a short ignition delay. The engine brake thermal efficiency between the POME blend and mineral diesel was comparable. Furthermore, B100 fuels showed lower engine power at higher brake-specific fuel consumption compared to other tested fuels. In terms of gaseous emissions, increasing POME blends led to an increase in NOx emissions. Meanwhile, as the engine load increased, NOx also continued to increase. The effect of the POME blend on the PM-NOx trade-off observation showed that B100 simultaneously increased the NOx and decreased the PM emissions. It can be concluded that POME creates a lower PM concentration while giving some negative feedback to NOx.
Roof Strata Behavior and Support Resistance Determination for Ultra-Thick Longwall Top Coal Caving Panel: A Case Study of the Tashan Coal Mine
Authors: Guo Jun , Feng Guorui , Wang Pengfei , Qi Tingye , Zhang Xiaorong , Yan Yonggan
Published: April 2018

The Longwall Top Coal Caving (LTCC) method has greatly improved the production of ultra-thick underground coal resources. However, face fall and support closure have been becoming highly frequent accidents at the working face, and seriously threaten the safety of miners. The key to avoiding these problems is to reveal the structural evolution of the roof strata and then choose a reasonable working resistance for the hydraulic supports. According to physical modeling, theoretical analysis and field observation of the LTCC panel, four kinds of structural models can be found and defined, in consideration of the coincident movement of key strata (KS) and the mining activities of upper face in overburden strata. The KS are performed as cantilever structures, hinged structures and voussoir beam structures at three different positions in roof strata. The structural characteristics of the KS and its movement laws are shown in the four structural modes. The loads acting on the support in the four typical structural models are also analyzed. The structural instability of the broken roof strata on the upper caving panel caused by the lower ultra-thick coal seam mining is considered to be the main reason for its face’s falls and support failures. Consequently, a method is proposed for calculating the working resistance of the support in the LTCC face, which is verified by the mining pressure monitoring in practice.
Impact of Cyber Attacks on High Voltage DC Transmission Damping Control
Authors: Fan Rui , Lian Jianming , Kalsi Karanjit , Elizondo Marcelo A.
Published: April 2018

Hybrid AC/HVDC (AC-HVDC) grids have evolved to become huge cyber-physical systems that are vulnerable to cyber attacks because of the wide attack surface and increasing dependence on intelligent electronic devices, computing resources and communication networks. This paper, for the first time, studies the impact of cyber attacks on HVDC transmission oscillation damping control.Three kinds of cyber attack models are considered: timing attack, replay attack and false data injection attack. Followed by a brief introduction of the HVDC model and conventional oscillation damping control method, the design of three attack models is described in the paper. These attacks are tested on a modified IEEE New England 39-Bus AC-HVDC system. Simulation results have shown that all three kinds of attacks are capable of driving the AC-HVDC system into large oscillations or even unstable conditions.
Design Method of Controllable Blade Angle and Orthogonal Optimization of Pressure Rise for a Multiphase Pump
Authors: Liu Ming , Tan Lei , Cao Shuliang
Published: April 2018

The hydraulic design method of controllable blade angle for rotodynamic multiphase pump with impeller and diffuser is proposed. The distribution of blade angle along the meridional streamline is governed by the normalized fourth-order and first-order polynomial function for impeller and diffuser, respectively. The orthogonal optimization method with five factors and four levels is employed by numerical simulation to optimize the geometry parameters, including the shroud angle at the leading and trailing edge βIs0, βIs1, the blade difference at inlet ∆βI0, and the coefficients at hub and shroud kh, ks. According to orthogonal analysis, the influence of each factor on pressure rise is estimated, and the optimization values of for those parameters are determined. The pressure rise of optimization multiphase pump is increased by 12.8 kPa in comparison of the base pump. Results show that the distributions of gas volume fraction (GVF) and the pressure become more uniform after optimization, which improves the transporting performance of the multiphase pump.
Investigation of Stratified Thermal Storage Tank Performance for Heating and Cooling Applications
Authors: Karim Azharul , Burnett Ashley , Fawzia Sabrina
Published: April 2018

A large amount of energy is consumed by heating and cooling systems to provide comfort conditions for commercial building occupants, which generally contribute to peak electricity demands. Thermal storage tanks in HVAC systems, which store heating/cooling energy in the off-peak period for use in the peak period, can be used to offset peak time energy demand. In this study, a theoretical investigation on stratified thermal storage systems is performed to determine the factors that significantly influence the thermal performance of these systems for both heating and cooling applications. Five fully-insulated storage tank geometries, using water as the storage medium, were simulated to determine the effects of water inlet velocity, tank aspect ratio and temperature difference between charging (inlet) and the tank water on mixing and thermocline formation. Results indicate that thermal stratification enhances with increased temperature difference, lower inlet velocities and higher aspect ratios. It was also found that mixing increased by 303% when the temperature difference between the tank and inlet water was reduced from 80 °C to 10 °C, while decreasing the aspect ratio from 3.8 to 1.0 increased mixing by 143%. On the other hand, increasing the inlet water velocity significantly increased the storage mixing. A new theoretical relationship between the inlet water velocity and thermocline formation has been developed. It was also found that inlet flow rates can be increased, without increasing the mixing, after the formation of the thermocline.
Non-Destructive Failure Detection and Visualization of Artificially and Naturally Aged PV Modules
Authors: Eder Gabriele C. , Voronko Yuliya , Hirschl Christina , Ebner Rita , Újvári Gusztáv , Mühleisen Wolfgang
Published: April 2018

Several series of six-cell photovoltaic test-modules—intact and with deliberately generated failures (micro-cracks, cell cracks, glass breakage and connection defects)—were artificially and naturally aged. They were exposed to various stress conditions (temperature, humidity and irradiation) in different climate chambers in order to identify (i) the stress-induced effects; (ii) the potential propagation of the failures and (iii) their influence on the performance. For comparison, one set of test-modules was also aged in an outdoor test site. All photovoltaic (PV) modules were thoroughly electrically characterized by electroluminescence and performance measurements before and after the accelerated ageing and the outdoor test. In addition, the formation of fluorescence effects in the encapsulation of the test modules in the course of the accelerated ageing tests was followed over time using UV-fluorescence imaging measurements. It was found that the performance of PV test modules with mechanical module failures was rather unaffected upon storage under various stress conditions. However, numerous micro-cracks led to a higher rate of degradation. The polymeric encapsulate of the PV modules showed the build-up of distinctive fluorescence effects with increasing lifetime as the encapsulant material degraded under the influence of climatic stress factors (mainly irradiation by sunlight and elevated temperature) by forming fluorophores. The induction period for the fluorescence effects of the polymeric encapsulant to be detectable was ~1 year of outdoor weathering (in middle Europe) and 300 h of artificial irradiation (with 1000 W/m2 artificial sunlight 300–2500 nm). In the presence of irradiation, oxygen—which permeated into the module through the polymeric backsheet—bleached the fluorescence of the encapsulant top layer between the cells, above cell cracks and micro-cracks. Thus, UV-F imaging is a perfect tool for on-site detection of module failures connected with a mechanical rupture of solar cells.
A Novel Improved Cuckoo Search Algorithm for Parameter Estimation of Photovoltaic (PV) Models
Authors: Kang Tong , Yao Jiangang , Jin Min , Yang Shengjie , Duong ThanhLong
Published: April 2018

Parameter estimation of photovoltaic (PV) models from experimental current versus voltage (I-V) characteristic curves acts a pivotal part in the modeling a PV system and optimizing its performance. Although many methods have been proposed for solving this PV model parameter estimation problem, it is still challenging to determine highly accurate and reliable solutions. In this paper, this problem is firstly transformed into an optimization problem, and an objective function (OF) is formulated to quantify the overall difference between the experimental and simulated current data. And then, to enhance the performance of original cuckoo search algorithm (CSA), a novel improved cuckoo search algorithm (ImCSA) is proposed, by combining three strategies with CSA. In ImCSA, a quasi-opposition based learning (QOBL) scheme is employed in the population initialization step of CSA. Moreover, a dynamic adaptation strategy is developed and introduced for the step size without Lévy flight step in original CSA. A dynamic adjustment mechanism for the fraction probability (Pa) is proposed to achieve better tradeoff between the exploration and exploitation to increase searching ability. Afterwards, the proposed ImCSA is used for solving the problem of estimating parameters of PV models based on experimental I-V data. Finally, the proposed ImCSA has been demonstrated on the parameter identification of various PV models, i.e., single diode model (SDM), double diode model (DDM) and PV module model (PMM). Experimental results indicate that the proposed ImCSA outperforms the original CSA and its superior performance in comparison with other state-of-the-art algorithms, and they also show that our proposed ImCSA is capable of finding the best values of parameters for the PV models in such effective way for giving the best possible approximation to the experimental I-V data of real PV cells and modules. Therefore, the proposed ImCSA can be considered as a promising alternative to accurately and reliably estimate parameters of PV models.
Value-Added Performance and Thermal Decomposition Characteristics of Dumped Food Waste Compost by Pyrolysis
Authors: Lee Ye-Eun , Jo Jun-Ho , Kim I-Tae , Yoo Yeong-Seok
Published: April 2018

Food waste compost has a high Na content, which interferes with plant growth when used as a soil enhancer and therefore makes it difficult to use. And, compared to the amount of compost produced every day, the amount of consumption required in farms is smaller, and the rest is buried underground, which releases greenhouse gases and pollutes underground water. This research compared and analyzed thermal degradation behavior, calorific value, and gas spectrometry during the pyrolysis between food waste compost and sawdust to suggest producing food waste compost biochar by pyrolysis as a new alternative solution to utilize the massive amount of food waste compost. Biochar from pyrolysis of food waste compost had a high carbon content of 51% at 300 °C, and the carbon content decreased as the pyrolysis temperature increased. According to the thermogravimetric analysis (TGA) and derivative thermo-gravimetric (DTG) analysis results, compost showed the largest weight reduction from 240 °C to 365 °C. The weight reduction temperature ranges for compost and sawdust were quite similar. This occurred because food waste of the compost was degraded, but sawdust of compost remained nearly during the composting process. A gas chromatography and mass spectrometry (GC-MS) analysis found that the gases were fragments of fatty acids, protein, and hemi-cellulose. These results could also have been caused by degradation of microorganisms involved in the composting process, sawdust, and small fragments of food waste. In the calorific value of biochar, the highest value (24.33 kJ/g) was obtained 300 °C. At a low pyrolysis temperature, carbon fixation occurred easily since the food waste in compost was degraded by microorganism, and the volatilization of sawdust, which plays an important role in determining the calorific value, was also small. That is why the highest calorific value was shown at 300 °C, not 400 °C or 500 °C. Hence, it seems that food waste compost can be used as a promising alternative fuel at a low pyrolysis temperature, as other lignocellulosic refuse-derived fuels (RDF).
Chromosome Synapsis and Recombination in Male-Sterile and Female-Fertile Interspecies Hybrids of the Dwarf Hamsters (Phodopus, Cricetidae)
Authors: Bikchurina Tatiana , Tishakova Katerina , Kizilova Elena , Romanenko Svetlana , Serdyukova Natalya , Torgasheva Anna , Borodin Pavel
Published: April 2018

Hybrid sterility is an important step in the speciation process. Hybrids between dwarf hamsters Phodopus sungorus and P. campbelli provide a good model for studies in cytological and genetic mechanisms of hybrid sterility. Previous studies in hybrids detected multiple abnormalities of spermatogenesis and a high frequency of dissociation between the X and Y chromosomes at the meiotic prophase. In this study, we found that the autosomes of the hybrid males and females underwent paring and recombination as normally as their parental forms did. The male hybrids showed a significantly higher frequency of asynapsis and recombination failure between the heterochromatic arms of the X and Y chromosomes than the males of the parental species. Female hybrids as well as the females of the parental species demonstrated a high incidence of centromere misalignment at the XX bivalent and partial asynapsis of the ends of its heterochromatic arms. In all three karyotypes, recombination was completely suppressed in the heterochromatic arm of the X chromosome, where the pseudoautosomal region is located. We propose that this recombination pattern speeds up divergence of the X- and Y-linked pseudoautosomal regions between the parental species and results in their incompatibility in the male hybrids.
Spatial Bricolage: The Art of Poetically Making Do
Authors: Roberts Les
Published: April 2018

This paper provides an introductory overview to the Humanities special issue on ‘spatial bricolage’. The individual contributions that make up the special issue are outlined and salient themes pulled out that address and respond to some the wider discussion points raised throughout this introduction. These are closely focused around the central concept of bricolage and the idea of the researcher as bricoleur. Some background context on the anthropological underpinnings to bricolage is provided, alongside methodological reflections that relate the concept to ideas of ‘gleaning’ as a creative and performative engagement with everyday spaces as they are ‘found’ and rehearsed in practice. A core focus on questions of method, and of autoethnographic approaches in particular, is presented alongside questions of research ethics and the policing thereof by institutional structures of disciplining and audit in the neoliberal academy. It is argued that bricolage is, among other things, a practical response to a field of practice that at times constrains as much as it allows space to roam, unimpeded, across disciplinary boundaries. From the overarching purview of spatial humanities and spatial anthropology, it is shown that discussions of bricolage and the researcher as bricoleur can help make explicit the poetics and affects of space, as well as the ethical and procedural frameworks that are brought to bear on how space is put into practice.
Mobile Exergaming in Adolescents’ Everyday Life—Contextual Design of Where, When, with Whom, and How: The SmartLife Case
Authors: Schwarz Ayla , DeSmet Ann , Cardon Greet , Chastin Sebastien , Costa Ruben , Grilo António , Ferri Josue , Domenech Jorge , Stragier Jeroen
Published: April 2018

Exergames, more specifically console-based exergames, are generally enjoyed by adolescents and known to increase physical activity. Nevertheless, they have a reduced usage over time and demonstrate little effectiveness over the long term. In order to increase playing time, mobile exergames may increase potential playing time, but need to be engaging and integrated in everyday life. The goal of the present study was to examine the context of gameplay for mobile exergaming in adolescents’ everyday life to inform game design and the integration of gameplay into everyday life. Eight focus groups were conducted with 49 Flemish adolescents (11 to 17 years of age). The focus groups were audiotaped, transcribed, and analyzed by means of thematic analysis via Nvivo 11 software (QSR International Pty Ltd., Victoria, Australia). The adolescents indicated leisure time and travel time to and from school as suitable timeframes for playing a mobile exergame. Outdoor gameplay should be restricted to the personal living environment of adolescents. Besides outdoor locations, the game should also be adaptable to at-home activities. Activities could vary from running outside to fitness exercises inside. Furthermore, the social context of the game was important, e.g., playing in teams or meeting at (virtual) meeting points. Physical activity tracking via smart clothing was identified as a motivator for gameplay. By means of this study, game developers may be better equipped to develop mobile exergames that embed gameplay in adolescents’ everyday life.
Social Network Analysis Applied to a Historical Ethnographic Study Surrounding Home Birth
Authors: Andina-Diaz Elena , Ovalle-Perandones Mª Antonia , Ramos-Vidal Ignacio , Camacho-Morell Francisca , Siles-Gonzalez Jose , Marques-Sanchez Pilar
Published: April 2018

Safety during birth has improved since hospital delivery became standard practice, but the process has also become increasingly medicalised. Hence, recent years have witnessed a growing interest in home births due to the advantages it offers to mothers and their newborn infants. The aims of the present study were to confirm the transition from a home birth model of care to a scenario in which deliveries began to occur almost exclusively in a hospital setting; to define the social networks surrounding home births; and to determine whether geography exerted any influence on the social networks surrounding home births. Adopting a qualitative approach, we recruited 19 women who had given birth at home in the mid 20th century in a rural area in Spain. We employed a social network analysis method. Our results revealed three essential aspects that remain relevant today: the importance of health professionals in home delivery care, the importance of the mother’s primary network, and the influence of the geographical location of the actors involved in childbirth. All of these factors must be taken into consideration when developing strategies for maternal health.
Effect of Drought on Agronomic Traits of Rice and Wheat: A Meta-Analysis
Authors: Zhang Jinmeng , Zhang Shiqiao , Cheng Min , Jiang Hong , Zhang Xiuying , Peng Changhui , Lu Xuehe , Zhang Minxia , Jin Jiaxin
Published: April 2018

Drought has been one of the most important limiting factors for crop production, which deleteriously affects food security worldwide. The main objective of the present study was to quantitatively assess the effect of drought on the agronomic traits (e.g., plant height, biomass, yield, and yield components) of rice and wheat in combination with several moderators (e.g., drought stress intensity, rooting environment, and growth stage) using a meta-analysis study. The database was created from 55 published studies on rice and 60 published studies on wheat. The results demonstrated that drought decreased the agronomic traits differently between rice and wheat among varying growth stages. Wheat and rice yields decreased by 27.5% and 25.4%, respectively. Wheat grown in pots showed greater decreases in agronomic traits than those grown in the field. Rice showed opposite growing patterns when compared to wheat in rooting environments. The effect of drought on rice increased with plant growth and drought had larger detrimental influences during the reproductive phase (e.g., blooming stage, filling stage, and maturity). However, an exception was found in wheat, which had similar decreased performance during the complete growth cycle. Based on these results, future droughts could produce lower yields of rice and wheat when compared to the current drought.
Do Low Income Youth of Color See “The Bigger Picture” When Discussing Type 2 Diabetes: A Qualitative Evaluation of a Public Health Literacy Campaign
Authors: Schillinger Dean , Tran Jessica , Fine Sarah
Published: April 2018

As Type 2 diabetes spikes among minority and low-income youth, there is an urgent need to tackle the drivers of this preventable disease. The Bigger Picture (TBP) is a counter-marketing campaign using youth-created, spoken-word public service announcements (PSAs) to reframe the epidemic as a socio-environmental phenomenon requiring communal action, civic engagement and norm change. Methods: We examined whether and how TBP PSAs advance health literacy among low-income, minority youth. We showed nine PSAs, asking individuals open-ended questions via questionnaire, then facilitating a focus group to reflect upon the PSAs. Results: Questionnaire responses revealed a balance between individual vs. public health literacy. Some focused on individual responsibility and behaviors, while others described socio-environmental forces underlying risk. The focus group generated a preponderance of public health literacy responses, emphasizing future action. Striking sociopolitical themes emerged, reflecting tensions minority and low-income youth experience, such as entrapment vs. liberation. Conclusion: Our findings speak to the structural barriers and complexities underlying diabetes risk, and the ability of spoken word medium to make these challenges visible and motivate action. Practice Implications: Delivering TBP content to promote interactive reflection has potential to change behavioral norms and build capacity to confront the social, economic and structural factors that influence behaviors.
The Status of Musculoskeletal Disorders and Its Influence on the Working Ability of Oil Workers in Xinjiang, China
Authors: Ge Hua , Sun Xuemei , Liu Jiwen , Zhang Chen
Published: April 2018

The purpose of this study was to investigate the status of musculoskeletal disorders (MSDs) and its influence on the working ability of oil workers, and to provide a theoretical basis for helping lessen the burden of MSDs and improve the man-machine environment of oil workers. The cluster sampling method was used to study 2000 workers who had been employed for more than 1 year in this field. We investigated the prevalence rate and the work ability index (WAI). A total of 1935 valid questionnaires were collected, a response rate of 96.75%. There were 1639 people who had suffered from MSDs in the past year, a prevalence rate of 84.7%. The damage detection rate in female oil workers was higher than in males, and the damage detection rate in workers aged 30 to 45 years was higher than that in the other two age groups. The detection rate in less highly-educated oil workers was higher than that in more highly-educated workers. The detection rate in divorced workers was higher than that in other groups. The detection rate in workers between the number of working years of 18 to 25 years was higher than in the other two groups. The detection rate in workers with a high professional title was significantly higher than that in lower-titled workers (p < 0.05). The results showed that the WAI scores of the subjects with MSDs were significantly lower than for subjects without MSDs (p < 0.05). In a logistic regression analysis, sex, number of working years and WAI index all had an impact on MSDs. We concluded that due to the demands of their role, the oil workers had serious MSDs that influenced their working ability.
Maternal Vaccination as an Essential Component of Life-Course Immunization and Its Contribution to Preventive Neonatology
Authors: Bergin Naomi , Murtagh Janice , Philip Roy K.
Published: April 2018

Maternal immunisation schedules are increasingly coming under the spotlight as part of the development of lifetime immunisation programmes for the role that they play in improving maternal, foetal, and neonatal health. Maternally-acquired antibodies are critical in protecting infants during the first months of their lives. Maternal immunisation was previously overlooked owing to concerns regarding vaccinations in this untested and high-risk population but is now acknowledged for its potential impact on the outcomes in many domains of foetal and neonatal health, aside from its maternal benefits. This article highlights the role that maternal immunisation may play in reducing infections in preterm and term infants. It explores the barriers to antenatal vaccinations and the optimisation of the immunisation uptake. This review also probes the part that maternal immunisation may hold in the reduction of perinatal antimicrobial resistance and the prevention of non-infectious diseases. Both healthcare providers and expectant mothers should continue to be educated on the importance and safety of the appropriate immunizations during pregnancy. Maternal vaccination merits its deserved priority in a life-course immunization approach and it is perhaps the only immunization whereby two generations benefit directly from a single input. We outline the current recommendations for antenatal vaccinations and highlight the potential advances in the field contributing to “preventive neonatology”.
Gender and Body-Fat Status as Predictors of Parental Feeding Styles and Children’s Nutritional Knowledge, Eating Habits and Behaviours
Authors: Lipowska Małgorzata , Lipowski Mariusz , Jurek Paweł , Jankowska Anna M. , Pawlicka Paulina
Published: April 2018

The home food environment is critically important for the development of children’s health-related practices. By managing dietary restrictions, providing nutritional knowledge and demonstrating eating behaviours, parents contribute to children’s food preferences and eating patterns. The present study examined nutritional knowledge, eating habits and appetite traits among 387 Polish five-year-old healthy and overfat boys and girls in the context of parental feeding styles and body-fat status. We observed that girls presented healthier eating habits than boys; however, overfat boys had better nutritional knowledge. Children’s body-fat percentage (%BF) was found to be linked with eating behaviours such as low satiety responsiveness and increased food responsiveness in girls as well as low emotional undereating and increased emotional overeating in boys. Our results revealed that overfat mothers, who were more prone to use the encouragement feeding style, rarely had daughters with increased %BF. Parents of overfat girls, however, were less likely to apply encouragement and instrumental feeding styles. Contrary to popular belief and previous studies, overfat women do not necessarily transmit unhealthy eating patterns to their children. Parents’ greater emphasis on managing the weight and eating habits of daughters (rather than sons) probably results from their awareness of standards of female physical attractiveness.
Observance of Sterilization Protocol Guideline Procedures of Critical Instruments for Preventing Iatrogenic Transmission of Creutzfeldt-Jakob Disease in Dental Practice in France, 2017
Authors: Bourgeois Denis , Dussart Claude , Saliasi Ina , Laforest Laurent , Tramini Paul , Carrouel Florence
Published: April 2018

Effective sterilization of reusable instruments contaminated by Creutzfeldt–Jakob disease in dental care is a crucial issue for public health. The present cross-sectional study investigated how the recommended procedures for sterilization were implemented by French dental practices in real-world settings. A sample of dental practices was selected in the French Rhône-Alpes region. Data were collected by a self-questionnaire in 2016. Sterilization procedures (n = 33) were classified into 4 groups: (1) Pre-sterilization cleaning of reusable instruments; (2) Biological verification of sterilization cycles—Monitoring steam sterilization procedures; (3) Autoclave performance and practitioner knowledge of autoclave use; (4) Monitoring and documentation of sterilization procedures—Tracking and tracing the instrumentation. Answers were provided per procedure, along with the global implementation of procedures within a group (over 80% correctly performed). Then it was verified how adherence to procedure groups varied with the size of the dental practice and the proportion of dental assistants within the team. Among the 179 questionnaires available for the analyses, adherence to the recommended procedures of sterilization noticeably varied between practices, from 20.7% to 82.6%. The median percentages of procedures correctly implemented per practice were 58.1%, 50.9%, 69.2% and 58.2%, in Groups 1, 2, 3 and 4, respectively (corresponding percentages for performing over 80% of the procedures in the group: 23.4%, 6.6%, 46.6% and 38.6%). Dental practices ≥ 3 dental units performed significantly better (>80%) procedures of Groups 2 and 4 (p = 0.01 and p = 0.002, respectively), while no other significant associations emerged. As a rule, practices complied poorly with the recommended procedures, despite partially improved results in bigger practices. Specific training regarding sterilization procedures and a better understanding of the reasons leading to their non-compliance are needed.
Association between Sleep Duration and Overweight/Obesity at Age 7–18 in Shenyang, China in 2010 and 2014
Authors: Sun Qi , Bai Yinglong , Zhai Lingling , Wei Wei , Jia Lihong
Published: April 2018

This study was designed to examine the association between sleep duration and being overweight/obese in primary, middle, and high school students. This was a multiple cross-sectional study using data from the 2010 and 2014 National Survey on Students’ Constitution and Health (CNSSCH). A total of 23,602 students aged 7–18 years were enrolled in this study. The prevalence of being overweight and obese—stratified by age, gender, and sleep duration—in 2010 and 2014 were compared. Sleep duration was categorized as <7 h, ≥7 to 8 h, ≥8 to 9 h, and ≥9 h. Overweight and obesity were defined according to the cut-point criteria in China. Multivariable logistic regression results in 2010 and 2014 revealed that students sleeping <7 h and aged 7–12 years had an increased risk of becoming overweight/obese. In 2010, the adjusted prevalence ratios of overweight for 7–12-year-old students sleeping <9 h was 1.196 (95%CI: 1.004–1.424) and 13–15-year-old students sleeping <8 h was 1.265 (95%CI: 1.023–1.565). In 2014, the adjusted prevalence ratios of overweight and obesity for 7–12-year-old students sleeping <9 h were 1.295 (95%CI: 1.091–1.537) and 1.231 (95%CI: 1.045–1.449); 16–18-year-old students sleeping <7 h were 1.530 (95%CI: 1.239–1.888) and 1.585 (95%CI: 1.270–2.081). Our study revealed that different levels of sleep curtailment increased the risk of becoming overweight/obesity in different age groups of students.
LiDAR—A Technology to Assist with Smart Cities and Climate Change Resilience: A Case Study in an Urban Metropolis
Authors: Garnett Ryan , Adams Matthew
Published: April 2018

In this paper, we demonstrate three unique use cases of LiDAR data and processing, which can be implemented in an urban metropolis to determine the challenges that are associated with climate change. LiDAR data for the City of Toronto were collected in April 2015 with a density of 10 points/m2. We utilized both a digital terrain model and a bare earth digital elevation model in this work. The first case study estimated storm water, in which we compared flow accumulation values and catchment areas generated with a 20-m DEM and a 1-m LiDAR DEM. The finer resolution DEM demonstrated that the urban street features play a significant role in flow accumulation by directing flows. Urban catchment areas were found to occur on spatial scales that were smaller than the 20-m DEM cell size. For the second case study, the solar potential in the City of Toronto was calculated based on the slope and aspect of each land parcel. According to area, 56% of the city was found to have high solar potential, with 33% and 11% having medium and low solar potential. For the third case study, we calculated the building heights for 16,715 high-rise buildings in Toronto, which were combined with ambulance and fire emergency response times required to reach the base of the building. All buildings that had more than 17 stories were within a 5-min response time for both fire and ambulance services. Only 79% and 88% of these buildings were within a 3-min response time for ambulance and fire emergencies, respectively. LiDAR data provides a highly detailed record of the built urban environment and can provide support in the planning and assessment of climate change resilience activities.