bluuebunny/crossref_metadata_2025 huggingface dataset:
Lidar Measurements of Dust Aerosols during Three Field Campaigns in 2010, 2011 and 2012 over Northwestern China
Authors: Zhou Tian , Xie Hailing , Bi Jianrong , Huang Zhongwei , Huang Jianping , Shi Jinsen , Zhang Beidou , Zhang Wu
Published: May 2018

Ground-based measurements were carried out during field campaigns in April–June of 2010, 2011 and 2012 over northwestern China at Minqin, the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) and Dunhuang. In this study, three dust cases were examined, and the statistical results of dust occurrence, along with physical and optical properties, were analyzed. The results show that both lofted dust layers and near-surface dust layers were characterized by extinction coefficients of 0.25–1.05 km−1 and high particle depolarization ratios (PDRs) of 0.25–0.40 at 527 nm wavelength. During the three campaigns, the frequencies of dust occurrence retrieved from the lidar observations were all higher than 88%, and the highest frequency was in April. The vertical distributions revealed that the maximum height of dust layers typically reached 7.8–9 km or higher. The high intensity of dust layers mostly occurred within the planetary boundary layer (PBL). The monthly averaged PDRs decreased from April to June, which implies a dust load reduction. A comparison of the relationship between the aerosol optical depth at 500 nm (AOD500) and the Angstrom exponent at 440–870 nm (AE440–870) confirms that there is a more complex mixture of dust aerosols with other types of aerosols when the effects of human activities become significant.
A Cardiac Cell Outgrowth Assay for Evaluating Drug Compounds Using a Cardiac Spheroid-on-a-Chip Device
Authors: Christoffersson Jonas , Meier Florian , Kempf Henning , Schwanke Kristin , Coffee Michelle , Beilmann Mario , Zweigerdt Robert , Mandenius Carl-Fredrik
Published: May 2018

Three-dimensional (3D) models with cells arranged in clusters or spheroids have emerged as valuable tools to improve physiological relevance in drug screening. One of the challenges with cells cultured in 3D, especially for high-throughput applications, is to quickly and non-invasively assess the cellular state in vitro. In this article, we show that the number of cells growing out from human induced pluripotent stem cell (hiPSC)-derived cardiac spheroids can be quantified to serve as an indicator of a drug’s effect on spheroids captured in a microfluidic device. Combining this spheroid-on-a-chip with confocal high content imaging reveals easily accessible, quantitative outgrowth data. We found that effects on outgrowing cell numbers correlate to the concentrations of relevant pharmacological compounds and could thus serve as a practical readout to monitor drug effects. Here, we demonstrate the potential of this semi-high-throughput “cardiac cell outgrowth assay” with six compounds at three concentrations applied to spheroids for 48 h. The image-based readout complements end-point assays or may be used as a non-invasive assay for quality control during long-term culture.
Mammary Stem Cells and Breast Cancer Stem Cells: Molecular Connections and Clinical Implications
Authors: Celià-Terrassa Toni
Published: May 2018

Cancer arises from subpopulations of transformed cells with high tumor initiation and repopulation ability, known as cancer stem cells (CSCs), which share many similarities with their normal counterparts. In the mammary gland, several studies have shown common molecular regulators between adult mammary stem cells (MaSCs) and breast cancer stem cells (bCSCs). Cell plasticity and self-renewal are essential abilities for MaSCs to maintain tissue homeostasis and regenerate the gland after pregnancy. Intriguingly, these properties are similarly executed in breast cancer stem cells to drive tumor initiation, tumor heterogeneity and recurrence after chemotherapy. In addition, both stem cell phenotypes are strongly influenced by external signals from the microenvironment, immune cells and supportive specific niches. This review focuses on the intrinsic and extrinsic connections of MaSC and bCSCs with clinical implications for breast cancer progression and their possible therapeutic applications.
Depression, Olfaction, and Quality of Life: A Mutual Relationship
Authors: Rochet Marion , El-Hage Wissam , Richa Sami , Kazour François , Atanasova Boriana
Published: May 2018

Olfactory dysfunction has been well studied in depression. Common brain areas are involved in depression and in the olfactory process, suggesting that olfactory impairments may constitute potential markers of this disorder. Olfactory markers of depression can be either state (present only in symptomatic phases) or trait (persistent after symptomatic remission) markers. This study presents the etiology of depression, the anatomical links between olfaction and depression, and a literature review of different olfactory markers of depression. Several studies have also shown that olfactory impairment affects the quality of life and that olfactory disorders can affect daily life and may be lead to depression. Thus, this study discusses the links between olfactory processing, depression, and quality of life. Finally, olfaction is an innovative research field that may constitute a new therapeutic tool for the treatment of depression.
Electron Nuclear Dynamics Simulations of Proton Cancer Therapy Reactions: Water Radiolysis and Proton- and Electron-Induced DNA Damage in Computational Prototypes
Authors: Teixeira Erico S. , Uppulury Karthik , Privett Austin J. , Stopera Christopher , McLaurin Patrick M. , Morales Jorge A.
Published: May 2018

Proton cancer therapy (PCT) utilizes high-energy proton projectiles to obliterate cancerous tumors with low damage to healthy tissues and without the side effects of X-ray therapy. The healing action of the protons results from their damage on cancerous cell DNA. Despite established clinical use, the chemical mechanisms of PCT reactions at the molecular level remain elusive. This situation prevents a rational design of PCT that can maximize its therapeutic power and minimize its side effects. The incomplete characterization of PCT reactions is partially due to the health risks associated with experimental/clinical techniques applied to human subjects. To overcome this situation, we are conducting time-dependent and non-adiabatic computer simulations of PCT reactions with the electron nuclear dynamics (END) method. Herein, we present a review of our previous and new END research on three fundamental types of PCT reactions: water radiolysis reactions, proton-induced DNA damage and electron-induced DNA damage. These studies are performed on the computational prototypes: proton + H2O clusters, proton + DNA/RNA bases and + cytosine nucleotide, and electron + cytosine nucleotide + H2O. These simulations provide chemical mechanisms and dynamical properties of the selected PCT reactions in comparison with available experimental and alternative computational results.
Metal-Free Organocatalysis
Authors: Csákÿ Aurelio G.
Published: May 2018

Fostering research in fundamental organic transformations is of utmost importance for the development of science.[...]
Hearing Loss in Adult Survivors of Childhood Cancer Treated with Radiotherapy
Authors: Khan Amber , Budnick Amy , Barnea Dana , Feldman Darren R. , Oeffinger Kevin C. , Tonorezos Emily S.
Published: May 2018

The ototoxic effects of radiotherapy have been poorly characterized. We examined adult survivors of childhood cancer who were treated with radiotherapy, which included the head, before the age of 22 years and between 1952 and 2016. Those who received platinum chemotherapy were excluded. Demographic, diagnosis, and treatment outcomes were captured. Audiograms were graded using the Chang and International Society of Paediatric Oncology ototoxicity (SIOP) scales. Among 276 patients with a history of radiation to sites that included the brain, orbit, nasopharynx, and total body irradiation, the median age at treatment was 10.1 years and 59% were male. Of 51 survivors who had post-treatment audiograms, 19 demonstrated severe hearing impairment according to both the Chang and SIOP scales after a median follow-up of 16.6 years. Of those with severe impairment, 10 were using hearing aids. Among the 23 patients with more than one audiogram, five had normal hearing on the first audiogram but hearing loss upon subsequent study. Ototoxic effects of radiotherapy are present in a significant portion of survivors, but impairment may present over time, and our results suggest that many are not being screened. Further, among patients with severe hearing loss, use of hearing aids is not universal. Expansion of access to audiology testing and hearing interventions may be warranted.
Child Malnutrition in Pakistan: Evidence from Literature
Authors: Asim Muhammad , Nawaz Yasir
Published: May 2018

Pakistan has one of the highest prevalences of child malnutrition as compared to other developing countries. This narrative review was accomplished to examine the published empirical literature on children’s nutritional status in Pakistan. The objectives of this review were to know about the methodological approaches used in previous studies, to assess the overall situation of childhood malnutrition, and to identify the areas that have not yet been studied. This study was carried out to collect and synthesize the relevant data from previously published papers through different scholarly database search engines. The most relevant and current published papers between 2000–2016 were included in this study. The research papers that contain the data related to child malnutrition in Pakistan were assessed. A total of 28 articles was reviewed and almost similar methodologies were used in all of them. Most of the researchers conducted the cross sectional quantitative and descriptive studies, through structured interviews for identifying the causes of child malnutrition. Only one study used the mix method technique for acquiring data from the respondents. For the assessment of malnutrition among children, out of 28 papers, 20 used the World Health Organization (WHO) weight for age, age for height, and height for weight Z-score method. Early marriages, large family size, high fertility rates with a lack of birth spacing, low income, the lack of breast feeding, and exclusive breastfeeding were found to be the themes that repeatedly emerged in the reviewed literature. There is a dire need of qualitative and mixed method researches to understand and have an insight into the underlying factors of child malnutrition in Pakistan.
Use of Modified Colloids and Membranes to Remove Metal Ions from Contaminated Solutions
Authors: Mokhter Mohd Akmali , Magnenet Claire , Lakard Sophie , Euvrard Myriam , Aden Moumin , Clément Sébastien , Mehdi Ahmad , Lakard Boris
Published: May 2018

An efficient process was developed allowing the removal of metal ions from polycontaminated aqueous solutions by combining modified colloids and membranes. Firstly, filtration experiments were performed using polyethersulfone membranes modified by a self-assembled multilayer film of polyelectrolytes. These polymer-modified membranes allowed the uptake of more than 90% of the metal ions initially present in the contaminated solutions (for solutions concentrated at 50 mg L−1). Secondly, adsorption experiments were carried out with colloidal silica encapsulated with carboxymethyl chitosan (SiO2-CMCS) or with mesoporous silica functionalized by grafting of 1,4,8,11-tetraazacyclotetradecane, i.e., cyclam (SiO2-cyclam). The adsorption capacity of these compounds was shown to be higher than numerous other literature-known adsorbents, reaching 68 and 61 mg g−1 towards Cu(II) for SiO2-CMCS and SiO2-cyclam, respectively. Finally, by coupling adsorption with ultrafiltration in the tangential mode, the removal of Cu(II), Ni(II) and Zn(II) ions was found to be improved, allowing to reach a removal efficiency of 99% towards Cu(II), Ni(II) and Zn(II) ions at a metal concentration of 50 mg L−1, and a promising removal efficiency around 70% at a very high metal concentration of 1200 mg L−1. The mechanisms involved in the capture of the metal ions by modified membranes and colloids are also discussed.
The Study of Characteristic Environmental Sites Affected by Diverse Sources of Mineral Matter Using Compositional Data Analysis
Authors: Speranza Antonio , Caggiano Rosa , Pavese Giulia , Summa Vito
Published: May 2018

Compositional data analysis was applied on mineral element concentrations (i.e., Al, Ti, Si, Ca, Mg, Fe, Sr) content in PM10, PM2.5 and PM1 simultaneous measurements at three characteristic environmental sites: kerbside, background and rural site. Different possible sources of mineral trace elements affecting the PM in the considered sites were highlighted. Particularly, results show that compositional data analysis allows for the assessment of chemical/physical differences between mineral element concentrations of PM. These differences can be associated with both different kinds of involved mineral sources and different mechanisms of accumulation/dispersion of PM at the considered sites.
Lu5Pd4Ge8 and Lu3Pd4Ge4: Two More Germanides among Polar Intermetallics
Authors: Freccero Riccardo , Solokha Pavlo , Proserpio Davide Maria , Saccone Adriana , De Negri Serena
Published: May 2018

In this study, two novel Lu5Pd4Ge8 and Lu3Pd4Ge4 polar intermetallics were prepared by direct synthesis of pure constituents. Their crystal structures were determined by single crystal X-ray diffraction analysis: Lu5Pd4Ge8 is monoclinic, P21/m, mP34, a = 5.7406(3), b = 13.7087(7), c = 8.3423(4) Å, β = 107.8(1), Z = 2; Lu3Pd4Ge4 is orthorhombic, Immm, oI22, a = 4.1368(3), b = 6.9192(5), c = 13.8229(9) Å, Z = 2. The Lu5Pd4Ge8 analysed crystal is one more example of non-merohedral twinning among the rare earth containing germanides. Chemical bonding DFT studies were conducted for these polar intermetallics and showing a metallic-like behavior. Gathered results for Lu5Pd4Ge8 and Lu3Pd4Ge4 permit to described both of them as composed by [Pd–Ge]δ– three dimensional networks bonded to positively charged lutetium species. From the structural chemical point of view, the studied compounds manifest some similarities to the Zintl phases, containing well-known covalent fragment i.e., Ge dumbbells as well as unique cis-Ge4 units. A comparative analysis of molecular orbital diagrams for Ge26– and cis-Ge10– anions with COHP results supports the idea of the existence of complex Pd–Ge polyanions hosting covalently bonded partially polarised Ge units. The palladium atoms have an anion like behaviour and being the most electronegative cause the noticeable variation of Ge species charges from site to site. Lutetium charges oscillate around +1.5 for all crystallographic positions. Obtained results explained why the classical Zintl-Klemm concept can’t be applied for the studied polar intermetallics.
Unveiling the History of a Peculiar Weevil-Plant Interaction in South America: A Phylogeographic Approach to Hydnorobius hydnorae (Belidae) Associated with Prosopanche americana (Aristolochiaceae)
Authors: Sequeira Andrea , Rocamundi Nicolás , Ferrer M. , Baranzelli Matias , Marvaldi Adriana
Published: May 2018

Interspecific interactions take place over both long and short time-frames. However, it is not completely understood if the interacting-partners persisted, migrated, or expanded in concert with Quaternary climate and landscape changes. We aim to understand whether there is concordance between the specialist weevil Hydnorobius hydnorae and its parasitic host plant, Prosopanche americana in space and time. We aim to determine whether Prosopanche had already established its range, and Hydnorobius later actively colonized this rare resource; or, if both host plant and herbivore expanded their range concomitantly. We performed population genetic, phylogeographic and Bayesian diffusion analysis of Cytochrome B sequences from 18 weevil localities and used paleodistribution models to infer host plant dispersal patterns. We found strong but uneven population structure across the range for H. hydnorae with weak signals of population growth, and haplotype network structure and SAMOVA groupings closely following biogeographic region boundaries. The ancestral areas for both Hydnorobius and Prosopanche are reconstructed in San Luis province within the Chaco Biogeographic province. Our results indicate a long trajectory of host-tracking through space and time, where the weevil has expanded its geographic range following its host plant, without significant demographic growth. We explore the past environmental changes that could underlie the boundaries between locality groups. We suggest that geographic dispersal without population growth in Hydnorobius could be enabled by the scarcity of the host plant itself, allowing for slow expansion rates and stable populations, with no need for significant demographic growth pulses to support range expansion.
RETRACTED: The Use of Tooth Particles as a Biomaterial in Post-Extraction Sockets. Experimental Study in Dogs
Authors: Calvo-Guirado José , Maté-Sánchez de Val José , Ramos-Oltra María , Pérez-Albacete Martínez Carlos , Ramírez-Fernández María , Maiquez-Gosálvez Manuel , Gehrke Sergio , Fernández-Domínguez Manuel , Romanos Georgios , Delgado-Ruiz Rafael
Published: May 2018

Objectives: The objective of this study was to evaluate new bone formation derived from freshly crushed extracted teeth, grafted immediately in post-extraction sites in an animal model, compared with sites without graft filling, evaluated at 30 and 90 days. Material and Methods: The bilateral premolars P2, P3, P4 and the first mandibular molar were extracted atraumatically from six Beagle dogs. The clean, dry teeth were ground immediately using the Smart Dentin Grinder. The tooth particles obtained were subsequently sieved through a special sorting filter into two compartments; the upper container isolating particles over 1200 μm, the lower container isolated particles over 300 μm. The crushed teeth were grafted into the post-extraction sockets at P3, P4 and M1 (test group) (larger and smaller post-extraction alveoli), while P2 sites were left unfilled and acted as a control group. Tissue healing and bone formation were evaluated by histological and histomorphometric analysis after 30 and 90 days. Results: At 30 days, test site bone formation was greater in the test group than the control group (p < 0.05); less immature bone was observed in the test group (25.71%) than the control group (55.98%). At 90 days, significant differences in bone formation were found with more in the test group than the control group. No significant differences were found in new bone formation when comparing the small and large alveoli post-extraction sites. Conclusions: Tooth particles extracted from dog’s teeth, grafted immediately after extractions can be considered a suitable biomaterial for socket preservation.
Topological Structures on DMC Spaces †
Authors: Nasser Rajai
Published: May 2018

Two channels are said to be equivalent if they are degraded from each other. The space of equivalent channels with input alphabet X and output alphabet Y can be naturally endowed with the quotient of the Euclidean topology by the equivalence relation. A topology on the space of equivalent channels with fixed input alphabet X and arbitrary but finite output alphabet is said to be natural if and only if it induces the quotient topology on the subspaces of equivalent channels sharing the same output alphabet. We show that every natural topology is σ -compact, separable and path-connected. The finest natural topology, which we call the strong topology, is shown to be compactly generated, sequential and T 4 . On the other hand, the strong topology is not first-countable anywhere, hence it is not metrizable. We introduce a metric distance on the space of equivalent channels which compares the noise levels between channels. The induced metric topology, which we call the noisiness topology, is shown to be natural. We also study topologies that are inherited from the space of meta-probability measures by identifying channels with their Blackwell measures.
A New Local Fractional Entropy-Based Model for Kidney MRI Image Enhancement
Authors: Al-Shamasneh Ala’a R. , Jalab Hamid A. , Palaiahnakote Shivakumara , Obaidellah Unaizah Hanum , Ibrahim Rabha W. , El-Melegy Moumen T.
Published: May 2018

Kidney image enhancement is challenging due to the unpredictable quality of MRI images, as well as the nature of kidney diseases. The focus of this work is on kidney images enhancement by proposing a new Local Fractional Entropy (LFE)-based model. The proposed model estimates the probability of pixels that represent edges based on the entropy of the neighboring pixels, which results in local fractional entropy. When there is a small change in the intensity values (indicating the presence of edge in the image), the local fractional entropy gives fine image details. Similarly, when no change in intensity values is present (indicating smooth texture), the LFE does not provide fine details, based on the fact that there is no edge information. Tests were conducted on a large dataset of different, poor-quality kidney images to show that the proposed model is useful and effective. A comparative study with the classical methods, coupled with the latest enhancement methods, shows that the proposed model outperforms the existing methods.
Remote Sensing Extraction Method of Tailings Ponds in Ultra-Low-Grade Iron Mining Area Based on Spectral Characteristics and Texture Entropy
Authors: Ma Baodong , Chen Yuteng , Zhang Song , Li Xuexin
Published: May 2018

With the rapid development of the steel and iron industry, ultra-low-grade iron ore has been developed extensively since the beginning of this century in China. Due to the high concentration ratio of the iron ore, a large amount of tailings was produced and many tailings ponds were established in the mining area. This poses a great threat to regional safety and the environment because of dam breaks and metal pollution. The spatial distribution is the basic information for monitoring the status of tailings ponds. Taking Changhe Mining Area as an example, tailings ponds were extracted by using Landsat 8 OLI images based on both spectral and texture characteristics. Firstly, ultra-low-grade iron-related objects (i.e., tailings and iron ore) were extracted by the Ultra-low-grade Iron-related Objects Index (ULIOI) with a threshold. Secondly, the tailings pond was distinguished from the stope due to their entropy difference in the panchromatic image at a 7 × 7 window size. This remote sensing method could be beneficial to safety and environmental management in the mining area.
Time-Fractional Diffusion with Mass Absorption in a Half-Line Domain due to Boundary Value of Concentration Varying Harmonically in Time
Authors: Povstenko Yuriy , Kyrylych Tamara
Published: May 2018

The time-fractional diffusion equation with mass absorption is studied in a half-line domain under the Dirichlet boundary condition varying harmonically in time. The Caputo derivative is employed. The solution is obtained using the Laplace transform with respect to time and the sin-Fourier transform with respect to the spatial coordinate. The results of numerical calculations are illustrated graphically.
A Hybrid MCMC Sampler for Unconditional Quantile Based on Influence Function
Authors: Laghlal El Moctar , Ndoye Abdoul Aziz Junior
Published: May 2018

In this study, we provide a Bayesian estimation method for the unconditional quantile regression model based on the Re-centered Influence Function (RIF). The method makes use of the dichotomous structure of the RIF and estimates a non-linear probability model by a logistic regression using a Gibbs within a Metropolis-Hastings sampler. This approach performs better in the presence of heavy-tailed distributions. Applied to a nationally-representative household survey, the Senegal Poverty Monitoring Report (2005), the results show that the change in the rate of returns to education across quantiles is substantially lower at the primary level.
Music Education for All: The raison d’être of Music Schools
Authors: De Alba Baikune , Díaz-Gómez Maravillas
Published: May 2018

Music schools, centres of non-formal music education, bring music to people of all ages as they work to achieve their main objective of offering practical musical training, for both instruments and voice. Their activities are centred in the town or city in which they are located, and their impact extends beyond the educational sphere: music schools are also a social force whose activities stimulate the local cultural scene. This study explores the work carried out by these schools in the Basque Country (Spain), where they have been operating for over 20 years. The analysis focuses on the range of music education they offer, their ability to respond to different demands and needs and how they relate to their social and educational environment. Furthermore, the paper examines whether music schools see other potential areas for growth and development and explores the factors that could positively or negatively impact their ability to achieve their objectives. The study adopts a description-oriented empirical-analytical methodology and applies the SWOT system. A total of 67 schools were included in the study. The results reveal the relevance of this ever-evolving model of education and confirm music schools as a key force in both music education and the sociocultural sphere in this country.
Implementation of a Single-Phase SST for the Interface between a 13.2 kV MVAC Network and a 750 V Bipolar DC Distribution
Authors: Yun Hyeok-Jin , Jeong Dong-Keun , Kim Ho-Sung , Kim Myoungho , Baek Ju-Won , Kim Ju-Yong , Kim Hee-Je
Published: May 2018

This paper presents the implementation of a single-phase solid-state transformer (SST) for the interface between a 13.2 kV medium voltage alternative current (MVAC) network and a 750 V bipolar DC distribution. The SST has ten cascaded subunits in consideration of the device rating and modulation index (MI). Each subunit consists of an AC/DC stage and a DC/DC stage with a high frequency isolated transformer (HFIT). The AC/DC stage consists of cascaded H-bridges (CHBs) to cope with the MVAC. The DC/DC stage employs a triple active bridge (TAB) converter for bipolar DC distribution. Topology analysis and controller design for this specific structure are discussed. In addition, the insulation of HFIT used in DC/DC converters is also discussed. A simple balancing controller at the AC/DC stage and a current sharing controller at the DC/DC stage are used to prevent DC-link voltage unbalance caused by the cascaded structure. The discussions are validated using a 150 kW single-phase 21-level SST prototype at the laboratory level.
A Pathway to Reduce Energy Consumption in the Thermal Stabilization Process of Carbon Fiber Production
Authors: Nunna Srinivas , Maghe Maxime , Fakhrhoseini Seyed Mousa , Polisetti Bhargav , Naebe Minoo
Published: May 2018

Process parameters, especially in the thermal stabilization of polyacrylonitrile (PAN) fibers, play a critical role in controlling the cost and properties of the resultant carbon fibers. This study aimed to efficiently handle the energy expense areas during carbon fiber manufacturing without reducing the quality of carbon fibers. We introduced a new parameter (recirculation fan frequency) in the stabilization stage and studied its influence on the evolution of the structure and properties of fibers. Initially, the progress of the cyclization reaction in the fiber cross-sections with respect to fan frequencies (35, 45, and 60 Hz) during stabilization was analyzed using the Australian Synchrotron-high resolution infrared imaging technique. A parabolic trend in the evolution of cyclic structures was observed in the fiber cross-sections during the initial stages of stabilization; however, it was transformed to a uniform trend at the end of stabilization for all fan frequencies. Simultaneously, the microstructure and property variations at each stage of manufacturing were assessed. We identified nominal structural variations with respect to fan frequencies in the intermediate stages of thermal stabilization, which were reduced during the carbonization process. No statistically significant variations were observed between the tensile properties of fibers. These observations suggested that, when using a lower fan frequency (35 Hz), it was possible to manufacture carbon fibers with a similar performance to those produced using a higher fan frequency (60 Hz). As a result, this study provided an opportunity to reduce the energy consumption during carbon fiber manufacturing.
Photovoltaic Integrated Shunt Active Power Filter with Simpler ADALINE Algorithm for Current Harmonic Extraction
Authors: Mohd Zainuri Muhammad Ammirrul Atiqi , Mohd Radzi Mohd Amran , Che Soh Azura , Mariun Norman , Abd Rahim Nasrudin , Teh Jiashen , Lai Ching-Ming
Published: May 2018

This manuscript presents a significant work in improving the current harmonics extraction algorithm and indirectly improving the injection current produced by a single-phase Photovoltaic Shunt Active Power Filter (PV SAPF). Improvement to the existing adaptive linear neuron (ADALINE) technique has been carried out, leading to the formation of a simpler ADALINE; it is expected to perform as fast as the current harmonics extraction algorithm. Further analysis on the DC link capacitor control algorithm, called “self-charging with step size error cancellation”, was also done to inspect the performance of the algorithm in a single-phase photovoltaic shunt active power filter system. Both algorithms, configured in single-phase PV SAPF, were simulated in MATLAB/Simulink (R2012b). A laboratory prototype was developed, and the algorithms were computed on a TMS320F28335 Digital Signal Processing (DSP) board for hardware implementation purposes. From the acquired results, the simpler ADALINE algorithm has effectively performed with lower total harmonic Distortion (THD) and outstanding compensation. The established algorithm of self-charging with step size error cancellation works well with single-phase PV SAPF and has shown less overshoot, a fast response time, and minimal energy losses.
Influencing Factors and Decoupling Elasticity of China’s Transportation Carbon Emissions
Authors: Wang Yong , Zhou Yu , Zhu Lin , Zhang Fei , Zhang Yingchun
Published: May 2018

Transportation is an important source of carbon emissions in China. Reduction in carbon emissions in the transportation sector plays a key role in the success of China’s energy conservation and emissions reduction. This paper, for the first time, analyzes the drivers of carbon emissions in China’s transportation sector from 2000 to 2015 using the Generalized Divisia Index Method (GDIM). Based on this analysis, we use the improved Tapio model to estimate the decoupling elasticity between the development of China’s transportation industry and carbon emissions. The results show that: (1) the added value of transportation, energy consumption and per capita carbon emissions in transportation have always been major contributors to China’s carbon emissions from transportation. Energy carbon emission intensity is a key factor in reducing carbon emissions in transportation. The carbon intensity of the added value and the energy intensity have a continuous effect on carbon emissions in transportation; (2) compared with the increasing factors, the decreasing factors have a limited effect on inhibiting the increase in carbon emissions in China’s transportation industry; (3) compared with the total carbon emissions decoupling state, the per capita decoupling state can more accurately reflect the relationship between transportation and carbon emissions in China. The state of decoupling between the development of the transportation industry and carbon emissions in China is relatively poor, with a worsening trend after a short period of improvement; (4) the decoupling of transportation and carbon emissions has made energy-saving elasticity more important than the per capita emissions reduction elasticity effect. Based on the conclusions of this study, this paper puts forward some policy suggestions for reducing carbon emissions in the transportation industry.
Synthesis of Heat-Integrated Water Allocation Networks: A Meta-Analysis of Solution Strategies and Network Features
Authors: Kermani Maziar , Kantor Ivan D. , Maréchal François
Published: May 2018

Industries consume large quantities of energy and water in their processes which are often considered to be peripheral to the process operation. Energy is used to heat or cool water for process use; additionally, water is frequently used in production support or utility networks as steam or cooling water. This enunciates the interconnectedness of water and energy and illustrates the necessity of their simultaneous treatment to improve energy and resource efficiency in industrial processes. Since the seminal work of Savulescu and Smith in 1998 introducing a graphical approach, many authors have contributed to this field by proposing graphically- or optimization-based methodologies. The latter encourages development of mathematical superstructures encompassing all possible interconnections. While a large body of research has focused on improving the superstructure development, solution strategies to tackle such optimization problems have also received significant attention. The goal of the current article is to study the proposed methodologies with special focus on mathematical approaches, their key features and solution strategies. Following the convention of Jeżowski, solution strategies are categorized into: decomposition, sequential, simultaneous, meta-heuristics and a more novel strategy of relaxation/transformation. A detailed, feature-based review of all the main contributions has also been provided in two tables. Several gaps have been highlighted as future research directions.
Tolerance Sensitivity Analysis and Robust Optimal Design Method of a Surface-Mounted Permanent Magnet Motor by Using a Hybrid Response Surface Method Considering Manufacturing Tolerances
Authors: Jun Cha-Seung , Kwon Byung-Il , Kwon Ohbong
Published: May 2018

This paper presents a robust optimal design method using a hybrid response surface method (H-RSM) which directly finds an optimal point satisfying a target Z-value or a probability of failure. Through three steps, this paper achieves the goal that is to increase the open-circuit airgap flux (OCAF) in a surface-mounted permanent magnet motor and decrease its variation caused by variations of the airgap lengths including an additional one between permanent magnets and rotor back yoke. First, the OCAF equation is derived from the magnetic equivalent circuit (MEC) considering the additional airgap. Then, the equation is validated by comparing its results with those of the finite element method (FEM) modeled by the slotless stator. Next, the tolerance sensitivity analysis, using the partial derivative of the OCAF equation with respect to the airgap length, is performed to investigate the effects of design variables on the OCAF. It is shown that increasing the magnet thickness is effective for both increasing mean of the OCAF and reducing its variation. Finally, robust optimal design is performed using the H-RSM, in which all data are obtained from the FEM modeled by the slotted stator. The results of the robust optimal design are verified using the FEM.
Use of Water Balance and Tracer-Based Approaches to Monitor Groundwater Recharge in the Hyper-Arid Gobi Desert of Northwestern China
Authors: Akiyama Tomohiro , Kubota Jumpei , Fujita Koji , Tsujimura Maki , Nakawo Masayoshi , Avtar Ram , Kharrazi Ali
Published: May 2018

The groundwater recharge mechanism in the hyper-arid Gobi Desert of Northwestern China was analyzed using water balance and tracer-based approaches. Investigations of evaporation, soil water content, and their relationships with individual rainfall events were conducted from April to August of 2004. Water sampling of rainwater, groundwater, and surface water was also conducted. During this period, 10 precipitation events with a total amount of 41.5 mm, including a maximum of 28.9 mm, were observed. Evaporation during the period was estimated to be 33.1 mm. Only the soil water, which was derived from the heaviest precipitation, remained in the vadose zone. This is because a dry surface layer, which was formed several days after the heaviest precipitation event, prevented evaporation. Prior to that, the heaviest precipitation rapidly infiltrated without being affected by evaporation. This is corroborated by the isotopic evidence that both the heaviest precipitation and the groundwater retained no trace of significant kinetic evaporation. Estimated δ-values of the remaining soil water based on isotopic fractionation and its mass balance theories also demonstrated no trace of kinetic fractionation in the infiltration process. Moreover, stable isotopic compositions of the heaviest precipitation and the groundwater were very similar. Therefore, we concluded that the high-intensity precipitation, which rapidly infiltrated without any trace of evaporation, was the main source of the groundwater.
Species- and Elevation-Dependent Growth Responses to Climate Warming of Mountain Forests in the Qinling Mountains, Central China
Authors: Liu Bo , Liang Eryuan , Liu Kang , Camarero J. Julio
Published: May 2018

Climate warming is significantly affecting the composition and function of forest ecosystems. However, the forest responses to climate change in sub-humid and temperate areas are understudied compared with cold and semi-arid areas. Here, we investigate the radial-growth responses of two subalpine conifer species along an elevational gradient located in the Qinling Mountains, a sub-humid and temperate area situated in central China. Three sites dominated by larch (Larix chinensis Beissn.) and two other sites dominated by fir (Abies fargesii Franch.) located at different elevations were sampled. L. chinensis at a higher elevation showed more common and stronger climatic signals than A. fargesii at a lower elevation. The radial growth of L. chinensis was limited by low pre-growing season temperatures and showed an increasing growth trend in the last few years. On the other hand, A. fargesii growth was limited by summer water shortage and it was characterized by a declining trend in the most recent decade. Consequently, L. chinensis would benefit from climate warming, whereas A. fargesii could be regarded as a vulnerable tree species to warming-induced drought stress.
Changes in Soil Enzyme Activities and Microbial Biomass after Revegetation in the Three Gorges Reservoir, China
Authors: Ren Qingshui , Song Hong , Yuan Zhongxun , Ni Xilu , Li Changxiao
Published: May 2018

Soil enzymes and microbes are central to the decomposition of plant and microbial detritus, and play important roles in carbon, nitrogen, and phosphorus biogeochemistry cycling at the ecosystem level. In the present study, we characterized the soil enzyme activity and microbial biomass in revegetated (with Taxodium distichum (L.) Rich. and Cynodon dactylon (L.) Pers.) versus unplanted soil in the riparian zone of the Three Gorges Dam Reservoir (TGDR), in order to quantify the effect of revegetation on the edaphic microenvironment after water flooding in situ. After revegetation, the soil physical and chemical properties in revegetated soil showed significant differences to those in unplanted soil. The microbial biomass carbon and phosphorus in soils of T. distichum were significantly higher than those in C. dactylon and unplanted soils, respectively. The microbial biomass nitrogen in revegetated T. distichum and C. dactylon soils was significantly increased by 273% and 203%, respectively. The enzyme activities of T. distichum and C. dactylon soils displayed no significant difference between each other, but exhibited a great increase compared to those of the unplanted soil. Elements ratio (except C/N (S)) did not vary significantly between T. distichum and C. dactylon soils; meanwhile, a strong community-level elemental homeostasis in the revegetated soils was found. The correlation analyses demonstrated that only microbial biomass carbon and phosphorus had a significantly positive relationship with soil enzyme activities. After revegetation, both soil enzyme activities and microbial biomasses were relatively stable in the T. distichum and C. dactylon soils, with the wooded soil being more superior. The higher enzyme activities and microbial biomasses demonstrate the C, N, and P cycling and the maintenance of soil quality in the riparian zone of the TGDR.
Ecological Impacts of Emerald Ash Borer in Forests at the Epicenter of the Invasion in North America
Authors: Klooster Wendy S. , Gandhi Kamal J. K. , Long Lawrence C. , Perry Kayla I. , Rice Kevin B. , Herms Daniel A.
Published: May 2018

We review research on ecological impacts of emerald ash borer (EAB)-induced ash mortality in the Upper Huron River watershed in southeast Michigan near the epicenter of the invasion of North America, where forests have been impacted longer than any others in North America. By 2009, mortality of green, white, and black ash exceeded 99%, and ash seed production and regeneration had ceased. This left an orphaned cohort of saplings too small to be infested, the fate of which may depend on the ability of natural enemies to regulate EAB populations at low densities. There was no relationship between patterns of ash mortality and ash density, ash importance, or community composition. Most trees died over a five-year period, resulting in relatively simultaneous, widespread gap formation. Disturbance resulting from gap formation and accumulation of coarse woody debris caused by ash mortality had cascading impacts on forest communities, including successional trajectories, growth of non-native invasive plants, soil dwelling and herbivorous arthropod communities, and bird foraging behavior, abundance, and community composition. These and other impacts on forest ecosystems are likely to be experienced elsewhere as EAB continues to spread.
Use of Stereology in Forest Inventories—A Brief History and Prospects for the Future
Authors: Lynch Thomas B. , Ståhl Göran , Gove Jeffrey H.
Published: May 2018

Several forest inventory techniques utilize approaches that are similar to stereological approaches often applied in microscopy and other fields. Stereology is characterized by the description and estimation of properties of objects based on samples of lower dimension than the object, e.g., 2-dimensional slices from 3-dimensional objects, 1-dimensional probes from 3-dimensional or 2-dimensional objects and dimensionless points from higher dimensional objects. The stereological character of many forest inventory methods was historically developed independently of recognition of a relationship with stereology. Strip sampling of forests, common in the late 19th and early 20th century, can be considered as a sterelogical approach if the strip centerline is viewed as a 1-dimensional probe of tree inclusion zones on a land area. The stereological character of plot sampling and Bitterlich sampling becomes evident if one views these methods as samples of 1-dimensional probes for volume within tree inclusion zones, or dimensionless points sampling for basal area in inclusion zones. Traditional methods of estimation of tree stem volume include samples of 2-dimensional cross-sectional area at fixed points along the tree stem to estimate 3-dimensional volume. Though these traditional methods usually use a shape assumption (e.g., parabolic frustum) for short stem segments, we show how a random-systematic start estimator of stem cross-sections can provide a design-unbiased estimate of stem volume without using any stem shape assumptions. Monte Carlo integration estimators of tree volume such as importance sampling that are designed to depend on only a few (usually one or two) tree upper-stem height or cross-sectional samples can also be viewed as stereological methods. Several forest inventory methods such as Matern’s individual tree basal area estimator and sector sampling can be viewed as local stereology, in which sample lines or slices pass through a central point. Finally, we suggest potential applications of stereological principles in the emerging “big data” era characterized by lidar and other remote sensing data and the assemblage of large tree and stand datasets. We suggest a new stem volume estimator which may have potential for future use with terrestrial lidar.
Separating Tree Photosynthetic and Non-Photosynthetic Components from Point Cloud Data Using Dynamic Segment Merging
Authors: Wang Di , Brunner Jasmin , Ma Zhenyu , Lu Hao , Hollaus Markus , Pang Yong , Pfeifer Norbert
Published: May 2018

Many biophysical forest properties such as wood volume and leaf area index (LAI) require prior knowledge on either photosynthetic or non-photosynthetic components. Laser scanning appears to be a helpful technique in nondestructively quantifying forest structures, as it can acquire an accurate three-dimensional point cloud of objects. In this study, we propose an unsupervised geometry-based method named Dynamic Segment Merging (DSM) to identify non-photosynthetic components of trees by semantically segmenting tree point clouds, and examining the linear shape prior of each resulting segment. We tested our method using one single tree dataset and four plot-level datasets, and compared our results to a supervised machine learning method. We further demonstrated that by using an optimal neighborhood selection method that involves multi-scale analysis, the results were improved. Our results showed that the overall accuracy ranged from 81.8% to 92.0% with an average value of 87.7%. The supervised machine learning method had an average overall accuracy of 86.4% for all datasets, on account of a collection of manually delineated representative training data. Our study indicates that separating tree photosynthetic and non-photosynthetic components from laser scanning data can be achieved in a fully unsupervised manner without the need of training data and user intervention.