bluuebunny/crossref_metadata_2025 huggingface dataset:
Electronic and Thermal Properties of Graphene and Recent Advances in Graphene Based Electronics Applications
Authors: Sang Mingyu , Shin Jongwoon , Kim Kiho , Yu Ki Jun
Published: March 2019

Recently, graphene has been extensively researched in fundamental science and engineering fields and has been developed for various electronic applications in emerging technologies owing to its outstanding material properties, including superior electronic, thermal, optical and mechanical properties. Thus, graphene has enabled substantial progress in the development of the current electronic systems. Here, we introduce the most important electronic and thermal properties of graphene, including its high conductivity, quantum Hall effect, Dirac fermions, high Seebeck coefficient and thermoelectric effects. We also present up-to-date graphene-based applications: optical devices, electronic and thermal sensors, and energy management systems. These applications pave the way for advanced biomedical engineering, reliable human therapy, and environmental protection. In this review, we show that the development of graphene suggests substantial improvements in current electronic technologies and applications in healthcare systems.
A Facile Method for Batch Preparation of Electrochemically Reduced Graphene Oxide
Authors: Hung Yi-Fang , Cheng Chia , Huang Chun-Kai , Yang Chii-Rong
Published: March 2019

The electrochemical reduction of graphene oxide (GO) is an environmentally friendly and energy-saving method for improving the characteristics of GO. However, GO films must be coated on the cathode electrode in advance when usingthis technique. Thus, the formed electrochemically reduced GO (ERGO) films can be used only as sensing or conductive materials in devices because mass production of the flakes is not possible. Therefore, this study proposes a facile electrochemical reduction technique. In this technique, GO flakes can be directly used as reduced materials, and no GO films are required in advance. A 0.1 M phosphate buffered saline solution was used as the electrolyte, which is a highly safe chemical agent. Experimental results revealed that the as-prepared GO flakes were electrochemically reduced to form ERGO flakes by using a −10 V bias for 8 h. The ratio of the D-band and G-band feature peaks was increased from 0.86 to 1.12, as revealed by Raman spectroscopy, the π-π stacking interaction operating between the ERGO and GO has been revealed by UV-Vis absorption spectroscopy, and the C–O ratio was increased from 2.02 to 2.56, as indicated by X-ray photoelectron spectroscopy. The electrical conductivity of the ERGO film (3.83 × 10−1 S·cm−1) was considerably better than that of the GO film (7.92 × 10−4 S·cm−1). These results demonstrate that the proposed electrochemical reduction technique can provide high-quality ERGO flakes and that it has potential for large-scale production.
Phosphate Ion-Modified RuO2/Ti3C2 Composite as a High-Performance Supercapacitor Material
Authors: Zhao Jie , Liu Faqian , Li Weihua
Published: March 2019

Pseudocapitor materials, usually metal oxides, are used as active materials in an electrode to achieve high energy density. However, these kinds of materials often suffer from poor conductivity and high cost. Herein, a phosphate ion-modified RuO2/Ti3C2 composite is prepared via a chemical solution synthesis followed by an annealing process. In this composite material, Ti3C2 layers are introduced to improve the conductivity and the binary material is doped with phosphate ions into to increase the number of active reaction sites. As a result, the phosphate ion-modified RuO2/Ti3C2 delivers a high specific capacitance of 612.72 F g−1 at a current density of 2 A g−1 in H2SO4 electrolyte. What is more, the capacitance of the phosphate ion-modified RuO2/Ti3C2 can retain 97.95% (600.14 F g−1) of the original value even after 10,000 cycles at a current density of 2 A g−1.
microRNA Expression Profiles in the Ventral Hippocampus during Pubertal Development and the Impact of Peri-Pubertal Binge Alcohol Exposure
Authors: Asimes AnnaDorothea , Kim Chun K. , Rao Yathindar S. , Bartelt Kyle , Pak Toni R.
Published: March 2019

Adolescence is hallmarked by two parallel processes of sexual maturation and adult patterning of the brain. Therefore, adolescence represents a vulnerable postnatal period for neurodevelopment where exogenous factors can negatively impact adult brain function. For example, alcohol exposure during pubertal development can lead to long-term and widespread neurobiological dysfunction and these effects have been shown to persist even in the absence of future alcohol exposure. However, the molecular mechanisms mediating the persistent effects of alcohol are unclear. We propose that dysregulation of microRNAs (miR) could be a unifying epigenetic mechanism underlying these widespread long-term changes. We tested the hypothesis that repeated alcohol exposure during pubertal development would cause disruption of normal miR expression profiles during puberty and, subsequently, their downstream mRNA target genes in the ventral hippocampus using an established rat model of adolescent binge drinking. We found 6 alcohol-sensitive miRs that were all downregulated following alcohol exposure and we also investigated the normal age-dependent changes in those miRs throughout the pubertal period. Interestingly, these miRs were normally decreased throughout the process of puberty, but alcohol prematurely exacerbated the normal decline in miR expression levels. The work presented herein provides foundational knowledge about the expression patterns of miRs during this critical period of neurodevelopment. Further, this regulation of miR and mRNA expression by alcohol exposure presents a complex regulatory mechanism by which perturbation in this time-sensitive period could lead to long-term neurological consequences.
Human Gut Microbiome Response Induced by Fermented Dairy Product Intake in Healthy Volunteers
Authors: Volokh Olesya , Klimenko Natalia , Berezhnaya Yulia , Tyakht Alexander , Nesterova Polina , Popenko Anna , Alexeev Dmitry
Published: March 2019

Accumulated data suggests that the gut microbiome can rapidly respond to changes in diet. Consumption of fermented dairy products (FDP) fortified with probiotic microbes may be associated with positive impact on human health. However, the extent and details of the possible impact of FDP consumption on gut community structure tends to vary across individuals. We used microbiome analysis to characterize changes in gut microbiota composition after 30 days of oral intake of a yoghurt fortified with Bifidobacterium animalis subsp. lactis BB-12. 16S rRNA gene sequencing was used to assess the gut microbial composition before and after FDP consumption in healthy adults (n = 150). Paired comparison of gut microbial content demonstrated an increase in presence of potentially beneficial bacteria, particularly, Bifidobacterium genus, as well as Adlercreutzia equolifaciens and Slackia isoflavoniconvertens. At a functional level, an increased capacity to metabolize lactose and synthesize amino acids was observed accompanied by a lowered potential for synthesis of lipopolysaccharides. Cluster analysis revealed that study volunteers segregated into two groups with post-intervention microbiota response that was dependent on the baseline microbial community structure.
Assessing Potentially Inappropriate Medications in Nursing Home Residents by NORGEP-NH Criteria
Authors: Halvorsen Kjell H. , Kucukcelik Sinan , Garcia Beate H. , Svendsen Kristian
Published: March 2019

Background: Nursing home residents often have several conditions that necessitate the use of multiple medicines. This study investigates the prevalence of potentially inappropriate medications (PIMs) and its associations with sex, age, number of medicines, and study location (rural/urban). Methods: A cross-sectional study of long-term care residents from six nursing homes. Data was collected from medical records. We identified PIMs by applying the NORGEP-NH criteria. We conducted a Poisson regression analysis to investigate the association between the number of PIMs and sex, age, number of medicines, and study location. Results: We included 103 (18.4%) of 559 residents (68.0% women; mean age 83.2 years, mean number of daily used medicines 7.2 (SD = 3.6)). We identified PIMs in 56% of the residents (mean number = 1.10, SD = 1.26). In adjusted analyses, residents ≥80 years had 0.43 fewer PIMs compared to residents <80 years (p < 0.05). Residents using 4–6, 7–9, and 10+ medicines had on average 0.73, 1.06, and 2.11 more PIMs compared to residents using 0–3 medicines (p < 0.001), respectively. Conclusion: PIM use is prevalent among nursing home residents and is significantly associated with age and number of medicines. Our findings suggest a modest decrease in residents using PIMs compared to previous studies. Nevertheless, prescribing quality in nursing home residents in both urban and rural areas is still of great concern.
Occurrence of Nine Pyrrolizidine Alkaloids in Senecio vulgaris L. Depending on Developmental Stage and Season
Authors: Flade Jens , Beschow Heidrun , Wensch-Dorendorf Monika , Plescher Andreas , Wätjen Wim
Published: March 2019

The contamination of phytopharmaceuticals and herbal teas with toxic plants is an increasing problem. Senecio vulgaris L. is a particularly noxious weed in agricultural and horticultural crops due to its content of toxic pyrrolizidine alkaloids (PAs). Since some of these compounds are carcinogenic, the distribution of this plant should be monitored. The amount of PAs in S. vulgaris is affected by various factors. Therefore, we investigated the occurrence of PAs depending on the developmental stage and season. A systematic study using field-plot experiments (four seasons, five developmental stages of the plants: S1 to S5) was performed and the PA concentration was determined via LC-MS/MS analysis. The total amount of PAs in the plant increased with the plant development, however, the total PA concentrations in µg/g dry matter remained nearly unchanged, whilst trends for specific PAs were observed. The concentrations of PA-N-oxides (PANOs) were much higher than that of tertiary PAs. Maximal amounts of the PA total were 54.16 ± 4.38 mg/plant (spring, S5). The total amount of PAs increased strongly until later developmental stages. Therefore, even small numbers of S. vulgaris may become sufficient for relevant contaminations set out by the maximal permitted daily intake levels recommended by the European Food Safety Authority (EFSA).
Influence of the On-time on the Ozone Production in Pulsed Dielectric Barrier Discharges
Authors: Montazersadgh Faraz , Wright Alexander , Ren Junchen , Shaw Alexander , Neretti Gabriele , Bandulasena Hemaka , Iza Felipe
Published: March 2019

Understanding the production mechanisms of ozone and other reactive species in atmospheric pressure dielectric barrier discharges (DBDs) has become increasingly important for the optimization and commercial success of these plasma devices in emerging applications, such as plasma medicine, plasma agriculture, and plasma catalysis. In many of these applications, input power modulation is exploited as a means to maintain a low gas temperature. Although the chemical pathways leading to ozone production/destruction and their strong temperature dependence are relatively well understood, the effect of the on-time duration on the performance of these modulated DBDs remains largely unexplored. In this study, we use electrical and optical diagnostics, as well as computational methods, to assess the performance of a modulated DBD device. The well-established Lissajous method for measuring the power delivered to the discharge is not suitable for modulated DBDs because the transients generated at the beginning of each pulse become increasingly important in short on-time modulated plasmas. It is shown that for the same input power and modulation duty-cycle, shorter on-time pulses result in significantly enhanced ozone production, despite their operation at slightly higher temperatures. The key underpinning mechanism that causes this counter-intuitive observation is the more efficient net generation rate of ozone during the plasma on-time due to the lower accumulation of NO2 in the discharge volume.
Sensitivity Enhancement of Acetone Gas Sensor using Polyethylene Glycol/Multi-Walled Carbon Nanotubes Composite Sensing Film with Thermal Treatment
Authors: Chiou Jin-Chern , Wu Chin-Cheng , Lin Tse-Mei
Published: March 2019

There is a need to develop a chemiresistive gas sensor equipped with a thermostat over a wide area for the sensor, which can protect the sensor from the influence of ambient temperature due to the uniform temperature of the thermostat. In this paper, we demonstrated an acetone gas sensor based on a polyethylene glycol (PEG)/Multi-walled Carbon Nanotubes (MWCNTs) composite film, which was equipped with a thermostat. The sensor was operated at modest working temperatures for sensor sensitivity enhancement. The optimum design of the polyimide-based thermostat with widely uniform thermal distribution was investigated in detail. It was found that the temperature uniformity of the thermostat was achieved using double spiral geometry. The experimental results of the sensor response showed that the PEG/MWCNTs composite film with a moderate working temperature revealed a higher sensitivity than that without thermal treatment. Moreover, the sensing mechanisms of the PEG/MWCNTs composite gas sensor to acetone vapor were studied as well.
Analysis on Water Inrush Process of Tunnel with Large Buried Depth and High Water Pressure
Authors: Yang Weimin , Fang Zhongdong , Wang Hao , Li Liping , Shi Shaoshuai , Ding Ruosong , Bu Lin , Wang Meixia
Published: March 2019

In order to explore the catastrophic evolution process for karst cave water inrush in large buried depth and high water pressure tunnels, a model test system was developed, and a similar fluid–solid coupled material was found. A model of the catastrophic evolution of water inrush was developed based on the Xiema Tunnel, and the experimental section was simulated using the finite element method. By analyzing the interaction between groundwater and the surrounding rocks during tunnel excavation, the law of occurrence of water inrush disaster was summarized. The water inrush process of a karst cave containing high-pressure water was divided into three stages: the production of a water flowing fracture, the expansion of the water flowing fracture, and the connection of the water flowing fracture. The main cause of water inrush in karst caves is the penetration and weakening of high-pressure water on the surrounding rock. This effect is becoming more and more obvious as tunnel excavation progresses. The numerical simulation results showed that the outburst prevention thickness of the surrounding rock is 4.5 m, and that of the model test result is 5 m. Thus, the results of the two methods are relatively close to each other. This work is important for studying the impact of groundwater on underground engineering, and it is of great significance to avoid water inrush in tunnels.
An Experimental Approach on Industrial Pd-Ag Supported α-Al2O3 Catalyst Used in Acetylene Hydrogenation Process: Mechanism, Kinetic and Catalyst Decay
Authors: Dehghani Ourmazd , Rahimpour Mohammad Reza , Shariati Alireza
Published: March 2019

The current research presents an experimental approach on the mechanism, kinetic and decay of industrial Pd-Ag supported α-Al2O3 catalyst used in the acetylene hydrogenation process. In the first step, the fresh and deactivated hydrogenation catalysts are characterized by XRD, BET (Brunauer–Emmett–Teller), SEM, TEM, and DTG analyses. The XRD results show that the dispersed palladium particles on the support surface experience an agglomeration during the reaction run time and mean particle size approaches from 6.2 nm to 11.5 nm. In the second step, the performance of Pd-Ag supported α-Al2O3 catalyst is investigated in a differential reactor in a wide range of hydrogen to acetylene ratio, temperature, gas hourly space velocity and pressure. The full factorial design method is used to determine the experiments. Based on the experimental results ethylene, ethane, butene, and 1,3-butadiene are produced through the acetylene hydrogenation. In the third step, a detailed reaction network is proposed based on the measured compounds in the product and the corresponding kinetic model is developed, based on the Langmuir-Hinshelwood-Hougen-Watson approach. The coefficients of the proposed kinetic model are calculated based on experimental data. Finally, based on the developed kinetic model and plant data, a decay model is proposed to predict catalyst activity and the parameters of the activity model are calculated. The results show that the coke build-up and condensation of heavy compounds on the surface cause catalyst deactivation at low temperature.
Nigeria and the Organization of Islamic Cooperation: A Discourse in Identity, Faith and Development, 1969–2016
Authors: Faseke Babajimi Oladipo
Published: March 2019

Nigeria is both a multi-ethnic and multi-religious society, with Islam and Christianity being the dominant religions. The Organisation of Islamic Cooperation (OIC) is therefore an institution that the Muslim segment of the country can readily identify with. However, there is the question of the secular posture of the country, which Christians within the polity use as an excuse to distance the country from an institution they perceive to be exclusively for Muslims. However, despite being an organization that emerged from Muslim solidarity, the OIC transcends faith to provide economic and political opportunities for member nations. The fact that Islam remains a rallying point within the OIC, however, made Nigeria’s relationship with the organization tenuous for the most part. It is against this backdrop that the paper traces the origins and evolution of Nigeria’s involvement with the OIC, identifying its cost and benefits. The essay argues that Nigeria will be the better for it if both the Christian and Muslim segments of the population embrace the OIC as a whole or are unanimous in discarding it. The divisive tendency that Nigeria’s membership breeds, however, will be detrimental to the nation’s unity and development.
Religious Freedom and the Limits of Propagation: Conversion in the Constituent Assembly of India
Authors: Claerhout Sarah , De Roover Jakob
Published: March 2019

In discussions about religious freedom in India, the country’s conflict regarding conversion plays a central role. The Constitution’s freedom of religion clause, Article 25, grants the right “freely to profess, practise and propagate religion,” but this has generated a dispute about the meaning of the right ‘to propagate’ and its relation to the freedom to convert. The recognition of this right is said to be the result of a key debate in the Constituent Assembly of India. To find out which ideas and arguments gave shape to this debate and the resulting religious freedom clause, we turn to the Assembly’s deliberations and come to a surprising conclusion: indeed, there was disagreement about conversion among the Assembly members, but this never took the form of a debate. Instead, there was a disconnect between the member’s concerns, objections, and comments concerning the draft article on the one hand, and the Assembly’s decision about the religious freedom clause on the other. If a key ‘debate’ took this form, what then could the ongoing dispute concerning conversion in India be about? We first examine some recent historiographical accounts of the Indian conflicts about conversion and proselytization. Then we develop a hypothesis that aims to make sense of this enduring conflict by identifying a blindness at its core: people reasoning against the background of Indian traditions see ‘propagation of religion’ as the human dissemination of tradition; this is incompatible with a religious conception where conversion and propagation of faith are seen in terms of God’s intervention. These two ways of seeing ‘propagation’ generate two conflicting experiences of the Indian dispute about religious freedom and conversion.
Machine Learning in Banking Risk Management: A Literature Review
Authors: Leo Martin , Sharma Suneel , Maddulety K.
Published: March 2019

There is an increasing influence of machine learning in business applications, with many solutions already implemented and many more being explored. Since the global financial crisis, risk management in banks has gained more prominence, and there has been a constant focus around how risks are being detected, measured, reported and managed. Considerable research in academia and industry has focused on the developments in banking and risk management and the current and emerging challenges. This paper, through a review of the available literature seeks to analyse and evaluate machine-learning techniques that have been researched in the context of banking risk management, and to identify areas or problems in risk management that have been inadequately explored and are potential areas for further research. The review has shown that the application of machine learning in the management of banking risks such as credit risk, market risk, operational risk and liquidity risk has been explored; however, it doesn’t appear commensurate with the current industry level of focus on both risk management and machine learning. A large number of areas remain in bank risk management that could significantly benefit from the study of how machine learning can be applied to address specific problems.
Complex-Valued Convolutional Autoencoder and Spatial Pixel-Squares Refinement for Polarimetric SAR Image Classification
Authors: Shang Ronghua , Wang Guangguang , A. Okoth Michael , Jiao Licheng
Published: March 2019

Recently, deep learning models, such as autoencoder, deep belief network and convolutional autoencoder (CAE), have been widely applied on polarimetric synthetic aperture radar (PolSAR) image classification task. These algorithms, however, only consider the amplitude information of the pixels in PolSAR images failing to obtain adequate discriminative features. In this work, a complex-valued convolutional autoencoder network (CV-CAE) is proposed. CV-CAE extends the encoding and decoding of CAE to complex domain so that the phase information can be adopted. Benefiting from the advantages of the CAE, CV-CAE extract features from a tiny number of training datasets. To further boost the performance, we propose a novel post processing method called spatial pixel-squares refinement (SPF) for preliminary classification map. Specifically, the majority voting and difference-value methods are utilized to determine whether the pixel-squares (PixS) needs to be refined or not. Based on the blocky structure of land cover of PolSAR images, SPF refines the PixS simultaneously. Therefore, it is more productive than current methods worked on pixel level. The proposed algorithm is measured on three typical PolSAR datasets, and better or comparable accuracy is obtained compared with other state-of-the-art methods.
Temporal Convolutional Neural Network for the Classification of Satellite Image Time Series
Authors: Pelletier Charlotte , Webb Geoffrey , Petitjean François
Published: March 2019

Latest remote sensing sensors are capable of acquiring high spatial and spectral Satellite Image Time Series (SITS) of the world. These image series are a key component of classification systems that aim at obtaining up-to-date and accurate land cover maps of the Earth’s surfaces. More specifically, current SITS combine high temporal, spectral and spatial resolutions, which makes it possible to closely monitor vegetation dynamics. Although traditional classification algorithms, such as Random Forest (RF), have been successfully applied to create land cover maps from SITS, these algorithms do not make the most of the temporal domain. This paper proposes a comprehensive study of Temporal Convolutional Neural Networks (TempCNNs), a deep learning approach which applies convolutions in the temporal dimension in order to automatically learn temporal (and spectral) features. The goal of this paper is to quantitatively and qualitatively evaluate the contribution of TempCNNs for SITS classification, as compared to RF and Recurrent Neural Networks (RNNs) —a standard deep learning approach that is particularly suited to temporal data. We carry out experiments on Formosat-2 scene with 46 images and one million labelled time series. The experimental results show that TempCNNs are more accurate than the current state of the art for SITS classification. We provide some general guidelines on the network architecture, common regularization mechanisms, and hyper-parameter values such as batch size; we also draw out some differences with standard results in computer vision (e.g., about pooling layers). Finally, we assess the visual quality of the land cover maps produced by TempCNNs.
Application of Mathematical Morphological Filtering to Improve the Resolution of Chang’E-3 Lunar Penetrating Radar Data
Authors: Zhang Jianmin , Zeng Zhaofa , Zhang Ling , Lu Qi , Wang Kun
Published: March 2019

As one of the important scientific instruments of lunar exploration, the Lunar Penetrating Radar (LPR) onboard China’s Chang’E-3 (CE-3) provides a unique opportunity to image the lunar subsurface structure. Due to the low-frequency and high-frequency noises of the data, only a few geological structures are visible. In order to better improve the resolution of the data, band-pass filtering and empirical mode decomposition filtering (EMD) methods are usually used, but in this paper, we present a mathematical morphological filtering (MMF) method to reduce the noise. The MMF method uses two structural elements with different scales to extract certain scale-range information from the original signal, at the same time, the noise beyond the scale range of the two different structural elements is suppressed. The application on synthetic signals demonstrates that the morphological filtering method has a better performance in noise suppression compared with band-pass filtering and EMD methods. Then, we apply band-pass filtering, EMD, and MMF methods to the LPR data, and the MMF method also achieves a better result. Furthermore, according to the result by MMF method, three stratigraphic zones are revealed along the rover’s route.
Automatic Ship Detection Based on RetinaNet Using Multi-Resolution Gaofen-3 Imagery
Authors: Wang Yuanyuan , Wang Chao , Zhang Hong , Dong Yingbo , Wei Sisi
Published: March 2019

Independent of daylight and weather conditions, synthetic aperture radar (SAR) imagery is widely applied to detect ships in marine surveillance. The shapes of ships are multi-scale in SAR imagery due to multi-resolution imaging modes and their various shapes. Conventional ship detection methods are highly dependent on the statistical models of sea clutter or the extracted features, and their robustness need to be strengthened. Being an automatic learning representation, the RetinaNet object detector, one kind of deep learning model, is proposed to crack this obstacle. Firstly, feature pyramid networks (FPN) are used to extract multi-scale features for both ship classification and location. Then, focal loss is used to address the class imbalance and to increase the importance of the hard examples during training. There are 86 scenes of Chinese Gaofen-3 Imagery at four resolutions, i.e., 3 m, 5 m, 8 m, and 10 m, used to evaluate our approach. Two Gaofen-3 images and one Constellation of Small Satellite for Mediterranean basin Observation (Cosmo-SkyMed) image are used to evaluate the robustness. The experimental results reveal that (1) RetinaNet not only can efficiently detect multi-scale ships but also has a high detection accuracy; (2) compared with other object detectors, RetinaNet achieves more than a 96% mean average precision (mAP). These results demonstrate the effectiveness of our proposed method.
Superpixel based Feature Specific Sparse Representation for Spectral-Spatial Classification of Hyperspectral Images
Authors: Sun He , Ren Jinchang , Zhao Huimin , Yan Yijun , Zabalza Jaime , Marshall Stephen
Published: March 2019

To improve the performance of the sparse representation classification (SRC), we propose a superpixel-based feature specific sparse representation framework (SPFS-SRC) for spectral-spatial classification of hyperspectral images (HSI) at superpixel level. First, the HSI is divided into different spatial regions, each region is shape- and size-adapted and considered as a superpixel. For each superpixel, it contains a number of pixels with similar spectral characteristic. Since the utilization of multiple features in HSI classification has been proved to be an effective strategy, we have generated both spatial and spectral features for each superpixel. By assuming that all the pixels in a superpixel belongs to one certain class, a kernel SRC is introduced to the classification of HSI. In the SRC framework, we have employed a metric learning strategy to exploit the commonalities of different features. Experimental results on two popular HSI datasets have demonstrated the efficacy of our proposed methodology.
Long-Term Trends of Atmospheric CH4 Concentration across China from 2002 to 2016
Authors: Wu Xiaodi , Zhang Xiuying , Chuai Xiaowei , Huang Xianjin , Wang Zhen
Published: March 2019

Spatiotemporal variations of atmospheric CH4 from 2002 to 2016 across China were detected, based on the Atmospheric Infrared Sounder (AIRS) sixth-layer CH4 concentration. The CH4 concentration showed good consistency with the ground measurements of surface CH4 concentration from the World Data Centre for Greenhouse Gases (WDCGG) (R2 = 0.83, p < 0.01), indicating that the remotely-sensed CH4 reflected the spatial and temporal variations of surface CH4 concentration. Across China, three hotspots of CH4 concentration were found in northern Xinjiang, the northeast of Inner Mongolia/Heilongjiang, and the Norgay plateau in northwest Sichuan. The CH4 concentration showed obviously seasonal variations, with the maximum CH4 concentration occurring in summer, followed by the autumn, winter, and spring. Furthermore, the CH4 concentration showed significantly increasing trends across China, with the rate of increase ranging from ~0.29 to 0.62 ppb·month−1, which would bring a 0.0019~0.014 mK potential rise in surface temperature response over China. In particular, the most rapidly increasing rates occurred in the Qinghai-Tibet plateau, while relatively low rates occurred in southeast China.
A High-Precision, Real-Time, and Robust Indoor Visible Light Positioning Method Based on Mean Shift Algorithm and Unscented Kalman Filter
Authors: Xie Zekun , Guan Weipeng , Zheng Jieheng , Zhang Xinjie , Chen Shihuan , Chen Bangdong
Published: March 2019

Visible light positioning (VLP) is a promising technology for indoor navigation. However, most studies of VLP systems nowadays only focus on positioning accuracy, whereas robustness and real-time ability are often overlooked, which are all indispensable in actual VLP situations. Thus, we propose a novel VLP method based on mean shift (MS) algorithm and unscented Kalman filter (UKF) using image sensors as the positioning terminal and a Light Emitting Diode (LED) as the transmitting terminal. The main part of our VLP method is the MS algorithm, realizing high positioning accuracy with good robustness. Besides, UKF equips the mean shift algorithm with the capacity to track high-speed targets and improves the positioning accuracy when the LED is shielded. Moreover, a LED-ID (the identification of the LED) recognition algorithm proposed in our previous work was utilized to locate the LED in the initial frame, which also initialized MS and UKF. Furthermore, experiments showed that the positioning accuracy of our VLP algorithm was 0.42 cm, and the average processing time per frame was 24.93 ms. Also, even when half of the LED was shielded, the accuracy was maintained at 1.41 cm. All these data demonstrate that our proposed algorithm has excellent accuracy, strong robustness, and good real-time ability.
Hybrid Fiber Optic Sensor, Based on the Fabry–Perot Interference, Assisted with Fluorescent Material for the Simultaneous Measurement of Temperature and Pressure
Authors: Jiang Xiaofeng , Lin Chun , Huang Yuanqing , Luo Kan , Zhang Jianhuan , Jiang Qingshan , Zhang Chentao
Published: March 2019

Herein we design a fiber sensor able to simultaneously measure the temperature and the pressure under harsh conditions, such as strong electromagnetic interference and high pressure. It is built on the basis of the fiber-optic Fabry–Perot (F–P) interference and the temperature sensitive mechanism of fluorescent materials. Both halogen lamps and light-emitting diodes (LED) are employed as the excitation light source. The reflected light from the sensor contains the low coherent information of interference cavity and the fluorescent lifetime. This information is independent due to the separate optical path and the different demodulation device. It delivers the messages of pressure and temperature, respectively. It is demonstrated that the sensor achieved pressure measurement at the range of 120–400 KPa at room temperature with a sensitivity of 1.5 nm/KPa. Moreover, the linearity of pressure against the cavity length variation was over 99.9%. In the meantime, a temperature measurement in the range of 25–80 °C, with a sensitivity of 0.0048 ms/°C, was obtained. These experimental results evince that this kind of sensor has a simple configuration, low-cost, and easy fabrication. As such, it can be particularly applied to many fields.
A Room Temperature Gas Sensor Based on Sulfonated SWCNTs for the Detection of NO and NO2
Authors: Ionete Eusebiu Ilarian , Spiridon Stefan Ionut , Monea Bogdan Florian , Stratulat Elena
Published: March 2019

The electrical response of sulfonated single-walled carbon nanotubes (SWCNTs) to NO and NO2, for gas sensing applications, at room temperature, is reported in this work. A specific configuration based on SWCNT deposition between double pair configuration gold electrodes, supported on a substrate, was considered for the sensing device; employed characterization technique where FTIR and SEM. The experimental results showed a p-type response of the sulfonated SWCNTs, with decrease in resistance, under exposure to NO gas (40–200 ppb) and NO2 (40–200 ppb). Also, the sensor responses to successive exposures at NO2 800 ppb together with investigation of long term stability, at 485 ppb for NO, are reported. The reaction mechanism in case of NO and NO2 detection with sulfonated SWCNTs is presented.
Eavesdropping and Jamming Selection Policy for Suspicious UAVs Based on Low Power Consumption over Fading Channels
Authors: Wang Xiaoming , Li Demin , Guo Chang , Zhang Xiaolu , Kanhere Salil S. , Li Kai , Tovar Eduardo
Published: March 2019

Traditional wireless security focuses on preventing unmanned aerial vehicle (UAV) communications from suspicious eavesdropping and/or jamming attacks. However, there is a growing need for governments to keep malicious UAV communications under legitimate surveillance. This paper first investigates a new surveillance paradigm for monitoring suspicious UAV communications via jamming suspicious UAVs. Due to the power consumption limitation, the choice of eavesdropping and jamming will reflect the performance of the UAVs communication. Therefore, the paper analyses the UAV’s eavesdropping and jamming models in different cases, and then proposes the model to optimize the data package in the constraints of lower power consumption, which can be solved by the proposed selection policy. The simulation results validate our proposed selection policy in terms of power consumption and eavesdropped packets. In different fading models, power consumption increases with time, regardless of distances, and our proposed policy performs better in Weibull fading channels in terms of eavesdropped packets.
Reconceptualising Children’s Agency as Continuum and Interdependence
Authors: Abebe Tatek
Published: March 2019

Although the idea that children are social actors is well-recognised within childhood studies, the structural contexts shaping child agency and the everyday practices that manifest in children’s social relationships with other generations are not fully elucidated. This article identifies and discusses multiple and often contradictory concepts of agency as well as a framework for re-conceptualizing it as a continuum, and as interdependent. The central argument I make is that there is a need to go beyond the recognition that children are social actors to reveal the contexts and relational processes within which their everyday agency unfolds. It is also vital to ask what kind of agency children have, how they come by and exercise it, and how their agency relates them to their families, communities, and others. The article draws on research and ongoing debates on the life worlds of children in diverse African contexts in order to critically demonstrate how their agency is intersected by experience, societal expectations, gender, geography, stage of childhood, and social maturity. In so doing, the contextualized discussions and reflections have implications to rethink childhood and child agency elsewhere.
A Qualitative Investigation of Music Use among Amateur and Semi-Professional Golfers
Authors: Gabana Nicole T. , Hutchinson Jasmin , Beauchemin James , Powless Matthew , Cawthra Julia , Halterman Aaron , Steinfeldt Jesse
Published: March 2019

Music use in golf receives minimal attention from both applied and empirical perspectives. Golfers, coaches, and sport psychology practitioners alike may benefit from understanding and utilizing music within their work. Since music use in golf has become an increasingly common practice, the purpose of the current study was to investigate current music use among golfers using a qualitative approach. Researchers aimed to identify potential psychological and physiological effects derived from music use during golf practice and pre-performance, given the limited empirical research in this area to date. Semi-structured interviews were conducted with ten amateur and semi-professional golfers (five male, five female, Mage = 22.9 years, SD = 5.04 years). Consensual qualitative research (CQR) methodology was used to analyze the interview data. Six domains emerged from the CQR analysis regarding participants’ self-reported music use in golf: tempo, attention, physiological regulation, psychological regulation, effects of music on performance perceptions, and context (to use or not to use). Given the capacity of carefully selected music to elicit profound affective, neurophysiological, and behavioral responses, there is clear potential for mental performance consultants to utilize music in working with golfers in training contexts. Implications, caveats, and future research recommendations are provided.
Phosphorus Demand for Food Security: A Case Study of a Food-Deficient Country
Authors: Kamal Thabiti Soudjay , Huang Yunfeng , Xu Su , Islam Imranul , Cui Shenghui
Published: March 2019

The modern global food production system relies heavily on a considerable input of phosphorus. Sustainable food and agriculture need integrated phosphorus management, especially in phosphorus-scarce and food-deficient countries. This study aimed to investigate the phosphorus requirements to meet the future food demand for a phosphorus-scarce and food-deficient country, Comoros, as a case study. With its rapid population growth, domestic food production is far from meeting the food demand in Comoros, and the country relies on imported foods to satisfy the national needs; it is currently a net food importer, an import-dependent nation. We first calculated the virtual and embedded phosphorus flows through food trade in Comoros, from 1991 to 2013, and then estimated the phosphorus requirements for the future food demand under two scenarios. We found that the total virtual and embedded phosphorus through imported food increased from 163,313 to 493,190.97 kg and 53,190.12 to 143,009.62 kg in 1991 and 2013, respectively. Whereas, the embedded phosphorus through exported food shifted from 2548.75 to 1334.5 kg in 1991 and 2013, respectively. In addition, the Self-Sufficiency Ratio (SSR) analysis found that Comoros’s SSR is far below 100%; it varied from 46.27% in 1991 to 29.70% in 2013, indicating that the capacity of domestic production to cover domestic consumption fell by 16.57% during that period. In terms of phosphorus requirements, Comoros will require approximately 3,003,435.09 kg of phosphorus to reach 90% of the SSR or 3,337,150.10 kg to achieve 100% of the SSR, by 2030. These amounts could allow farmers to domestically produce the entire volume of food crops and livestock products that would otherwise be imported from trade.
Internet Penetration and the Environmental Kuznets Curve: A Cross-National Analysis
Authors: Zhang Zhenbo , Meng Xiaohua
Published: March 2019

The internet has revolutionized the pattern of economic growth and its environmental effects. We investigate the ways in which internet penetration influences the relationship between income and the environment using data from 1996 to 2014 on CO2 emissions from 115 countries with multiple levels of per capita GDP and internet penetration. Empirical results document the existence of the Environmental Kuznets Curve (EKC) and reveal that internet penetration does generally reduce the actual income level beyond which pollution begins to decrease. Further tests, based on the division of income and period, indicate an increasing negative influence of internet penetration on emissions reduction, with income growth and the environmental effect of the internet evolving from direct and indirect to systemic. We discuss this study’s contributions to further research on income-environment paths and implications for the role of the internet in emissions reduction.
Carbon Emission Allocation in a Chinese Province-Level Region Based on Two-Stage Network Structures
Authors: Jin Xi , Zou Bin , Wang Chan , Rao Kaifeng , Tang Xiaowen
Published: March 2019

With the increasingly severe global environment and climate change, the growing social attention toward the environmental problems has prompted local governments to make policy adjustments. The formulation of the carbon emission right allocation scheme is important for policy-makers. Many researchers have studied the problem of carbon emission right allocation by using data envelopment analysis (DEA) models. However, the existing literature using traditional models consider each Decision-Making Unit (DMU) as a “black box” without taking the internal structure into account, but in fact, it is more accurate for formulating the scheme when considering the inner operation of DMUs. This paper investigates the allocation plan of carbon emission right among each province in China from 2007–2016 based on a two-stage DEA model. The results indicate that, first, there is no space for carbon emission in the north, northeast, and northwest from 2007–2016, while in the southern regions, it always exists. In addition, the carbon emission permits of the southern and eastern regions are increasing, but in the southwestern regions, the carbon emission space barely fluctuated during this decade. Second, the potential of carbon emission reduction of each region tends to be stable after 2014, and in the north and northwest, it fluctuated greatly from 2007–2016. Besides, the northwest region has had the potential of emission reduction since 2010, while it also exists in the northern region after 2014.
Environmental Variations in Mycobacterium ulcerans Transcriptome: Absence of Mycolactone Expression in Suboptimal Environments
Authors: Sanhueza Daniel , Guégan Jean-François , Jordan Heather , Chevillon Christine
Published: March 2019

Buruli ulcer is a neglected tropical infectious disease, produced by the environmentally persistent pathogen Mycobacterium ulcerans (MU). Neither the ecological niche nor the exact mode of transmission of MU are completely elucidated. However, some environmental factors, such as the concentration in chitin and pH values, were reported to promote MU growth in vitro. We pursued this research using next generation sequencing (NGS) and mRNA sequencing to investigate potential changes in MU genomic expression profiles across in vitro environmental conditions known to be suitable for MU growth. Supplementing the growth culture medium in either chitin alone, calcium alone, or in both chitin and calcium significantly impacted the MU transcriptome and thus several metabolic pathways, such as, for instance, those involved in DNA synthesis or cell wall production. By contrast, some genes carried by the virulence plasmid and necessary for the production of the mycolactone toxin were expressed neither in control nor in any modified environments. We hypothesized that these genes are only expressed in stressful conditions. Our results describe important environmental determinants playing a role in the pathogenicity of MU, helping the understanding of its complex natural life cycle and encouraging further research using genomic approaches.
Gender Mainstreaming in Waste Education Programs: A Conceptual Framework
Authors: dos Muchangos Letícia Sarmento , Vaughter Philip
Published: March 2019

Gender issues are present in waste management, from daily handling activities through to decision-making processes. In waste education programs, the disregard for views of and contribution by women has resulted in strategies that do not comprehensively address the waste issue, preventing long-standing and sustainable outcomes, while increasing existing gender inequities. Three critical waste matters on education and gender were identified: (1) lack of meaningful involvement and participation of women (and other vulnerable groups) throughout the decision-making processes; (2) lack of inclusion of gender-specific designs and gender-sensitive approaches in the information and education materials; and (3) tendency to devise strategies directed to women only, while exempting the other stakeholders from their responsibilities. This paper presents a closer look into the relationship between waste education and gender, with a proposal of a participatory framework for gender mainstreaming in waste education programs. It includes components to assess the promoting entity of the waste education program and all stages of the program. The framework represents a novel theory and practice contribution for waste education development, to support academics, practitioners, and policymakers, in the quest of achieving equitable and sustainable waste management systems for all.