bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlling the Spatial Direction of Hydrothermally Grown Rutile TiO2 Nanocrystals by the Orientation of Seed Crystals
Authors: Kalb Julian , Dorman James A. , Siroky Stephan , Schmidt-Mende Lukas
Published: January 2019

Hydrothermally grown TiO2 nanorods are a key material for several electronic applications. Due to its anisotropic crystal structure, the electronic properties of this semiconductor depend on the crystallographic direction. Consequently, it is important to control the crystal orientation to optimize charge carrier pathways. So far, the growth on common polycrystalline films such as fluorine tin oxide (FTO) results in randomly distributed growth directions. In this paper, we demonstrate the ability to control the growth direction of rutile TiO2 nanocrystals via the orientation of the seed crystals. The control of the orientation of such nanocrystals is an important tool to adjust the electronic, mechanical, and chemical properties of nanocrystalline films. We show that each employed macroscopic seed crystal provides the growth of parallel nanofingers along the [001] direction under specific angles. The parallel growth of these nanofingers leads to mesocrystalline films whose thickness and surface structure depends on the crystal orientation of the seed crystal. In particular, the structure of the films is closely linked with the known inner structure of hydrothermally grown rutile TiO2 nanorods on FTO. Additionally, comprehensive 1D structures on macroscopic single-crystals are generated by branching processes. These branched nanocrystals form expanded 2D defect planes, which provide the opportunity of defect doping-induced two-dimensional electronic systems (2DES).
Magnetic and Electronic Properties of π-d Interacting Molecular Magnetic Superconductor κ-(BETS)2FeX4 (X = Cl, Br) Studied by Angle-Resolved Heat Capacity Measurements
Authors: Fukuoka Shuhei , Fukuchi Sotarou , Akutsu Hiroki , Kawamoto Atsushi , Nakazawa Yasuhiro
Published: January 2019

Thermodynamic picture induced by π-d interaction in a molecular magnetic superconductor κ-(BETS)2FeX4 (X = Cl, Br), where BETS is bis(ethylenedithio)tetraselenafulvalene, studied by single crystal calorimetry is reviewed. Although the S = 5/2 spins of Fe3+ in the anion layers form a three-dimensional long-range ordering with nearly full entropy of Rln6, a broad hump structure appears in the temperature dependence of the magnetic heat capacity only when the magnetic field is applied parallel to the a axis, which is considered as the magnetic easy axis. The scaling of the temperature dependence of the magnetic heat capacity of the two salts is possible using the parameter of |Jdd|/kB and therefore the origin of the hump structure is related to the direct magnetic interaction, Jdd, that is dominant in the system. Quite unusual crossover from a three-dimensional ordering to a one-dimensional magnet occurs when magnetic fields are applied parallel to the a axis. A notable anisotropic field-direction dependence against the in-plane magnetic field was also observed in the transition temperature of the bulk superconductivity by the angle-resolved heat capacity measurements. We discuss the origin of this in-plane anisotropy in terms of the 3d electron spin configuration change induced by magnetic fields.
Effect of the Gaseous Atmosphere in GaAs Films Grown by Close-Spaced Vapor Transport Technique
Authors: Cruz Bueno J. Jesús , García Salgado Godofredo , Balderas Valadez R. Fabiola , Luna López J. Alberto , Nieto Caballero F. Gabriela , Díaz Becerril Tomás , Rosendo Andrés Enrique , Coyopol Solís Antonio , Romano Trujillo Román , Morales Ruiz Crisóforo , Gracia Jiménez J. Miguel , Galeazzi Isasmendi Reina
Published: January 2019

The effect of the gaseous atmosphere in the growth of gallium arsenide (GaAs) films was studied. The films have been grown by close-spaced vapor transport (CSVT) technique in a home-made hot filament chemical vapor deposition (HFCVD) reactor using molecular hydrogen and molecular nitrogen as the transport agent. An important point about the gaseous atmosphere is the ease in creating volatile compounds when it makes contact with the GaAs source, this favors the transport of material in a CSVT system. Chemical reactions are proposed in order to understand the significant difference produced from the gaseous atmosphere. The films grown with hydrogen are (almost) continuous and have homogeneous layers with preferential orientation (111). The films grown with nitrogen are granular and rough layers with the coexistence of the orientations (111), (220) and (311) in the crystals. The incorporation of impurities in the films was corroborated by energy dispersive spectroscopy (EDS) showing traces of oxygen and nitrogen for the case of the samples obtained with nitrogen. Films grown in a hydrogen atmosphere show a higher band gap than those grown in a nitrogen atmosphere. With the results of XRD and micro-Raman we observe a displacement and broadening of the peaks, characteristic of a structural disorder. The calculations of the FWHM allow us to observe the crystallinity degree and determine an approximate crystallite size using the Scherrer’s equation.
An Entropy-Based Neighborhood Rough Set and PSO-SVRM Model for Fatigue Life Prediction of Titanium Alloy Welded Joints
Authors: Zou Li , Sun Yibo , Yang Xinhua
Published: January 2019

In order to obtain comprehensive assessment of the factors influencing fatigue life and to further improve the accuracy of fatigue life prediction of welded joints, soft computing methods, including entropy-based neighborhood rough set reduction algorithm, the particle swarm optimization (PSO) algorithm and support vector regression machine (SVRM) are combined to construct a fatigue life prediction model of titanium alloy welded joints. By using an entropy-based neighborhood rough set reduction algorithm, the influencing factors of the fatigue life of titanium alloy welded joints such as joint type, plate thickness, etc. are analyzed and the reduction results are obtained. Fatigue characteristic domains are proposed and determined subsequently according to the reduction results. The PSO-SVRM model for fatigue life prediction of titanium alloy welded joints is established in the suggested fatigue characteristic domains. Experimental results show that by taking into account the impact of joint type, the PSO-SVRM model could better predict the fatigue life of titanium alloy welded joints. The PSO-SVRM model indicates the relationship between fatigue life and fatigue life influencing factors in multidimensional space compared with the conventional least-square S-N curve fitting method, it could predict the fatigue life of the titanium alloy welded joints more accurately thus helps to the reliability design of the structure.
Seismicity Pattern Changes Prior to the 2008 Ms7.3 Yutian Earthquake
Authors: Huang Qinghua
Published: January 2019

Seismicity pattern changes that are associated with strong earthquakes are an interesting topic with potential applications for natural hazard mitigation. As a retrospective case study of the Ms7.3 Yutian earthquake, which was an inland normal faulting event that occurred on 21 March 2008, the Region-Time-Length (RTL) method is applied to the seismological data of the China Earthquake Administration (CEA) to analyze the features of the seismicity pattern changes before the Yutian earthquake. The temporal variations of the RTL parameters of the earthquake epicenter showed that a quiescence anomaly of seismicity appeared in 2005. The Yutian main shock did not occur immediately after the local seismicity recovered to the background level, but with a time delay of about two years. The spatial variations of seismic quiescence indicated that an anomalous zone of seismic quiescence appeared near the Yutian epicentral region in 2005. This result is consistent with that obtained from the temporal changes of seismicity. The above spatio-temporal seismicity changes prior to the inland normal faulting Yutian earthquake showed similar features to those reported for some past strong earthquakes with inland strike faulting or thrust faulting. This study may provide useful information for understanding the seismogenic evolution of strong earthquakes.
Stability Analysis for Memristor-Based Complex-Valued Neural Networks with Time Delays
Authors: Hou Ping , Hu Jun , Gao Jie , Zhu Peican
Published: January 2019

In this paper, the problem of stability analysis for memristor-based complex-valued neural networks (MCVNNs) with time-varying delays is investigated extensively. This paper focuses on the exponential stability of the MCVNNs with time-varying delays. By means of the Brouwer’s fixed-point theorem and M-matrix, the existence, uniqueness, and exponential stability of the equilibrium point for MCVNNs are studied, and several sufficient conditions are obtained. In particular, these results can be applied to general MCVNNs whether the activation functions could be explicitly described by dividing into two parts of the real parts and imaginary parts or not. Two numerical simulation examples are provided to illustrate the effectiveness of the theoretical results.
A Case Study on Optimization and Control Techniques for Entry Stability in Non-Pillar Longwall Mining
Authors: Yang Xiaojie , Wang Eryu , Ma Xingen , Zhang Guofeng , Huang Ruifeng , Lou Haopeng
Published: January 2019

In order to reduce large deformation failure occurrences in non-pillar longwall mining entries due to roof weighting behaviors, a case study in Halagou coal mine was conducted on optimization and control techniques for entry stability in non-pillar longwall mining. The Universal Discrete Element Code (UDEC) modeling was adopted to study entry stability in non-pillar mining, and the characteristics of deformation and stress and crack propagation were revealed. The large deformation transmission between the entry-immediate roof and the gob-immediate roof could be eliminated by optimizing the entry roof structure through a directional roof-cutting method. The localized tensile stresses generated in the entry-surrounding rock caused the generation of coalescent macroscopic fractures, which resulted in the instability of the entry. The tensile stress state could be inhibited by an active flexible support system through enhancing the confining pressure on the surrounding rock. Serious rotation subsidence occurs in the entry roof due to periodic weighting of the main roof, which could be greatly reduced by a passive rigid support pattern. The numerical and field test results both showed that the roof weighting pressure was offloaded by the technique and that the deformation of the entry surrounding the rock in non-pillar mining was quite small. Thus, the technique can effectively ensure the stability of the gob-side entry, which can provide references for entry stability control in non-pillar longwall mining.
Computational Intelligence on Short-Term Load Forecasting: A Methodological Overview
Authors: Fallah Seyedeh Narjes , Ganjkhani Mehdi , Shamshirband Shahaboddin , Chau Kwok-wing
Published: January 2019

Electricity demand forecasting has been a real challenge for power system scheduling in different levels of energy sectors. Various computational intelligence techniques and methodologies have been employed in the electricity market for short-term load forecasting, although scant evidence is available about the feasibility of these methods considering the type of data and other potential factors. This work introduces several scientific, technical rationales behind short-term load forecasting methodologies based on works of previous researchers in the energy field. Fundamental benefits and drawbacks of these methods are discussed to represent the efficiency of each approach in various circumstances. Finally, a hybrid strategy is proposed.
Maximizing the Economic Benefits of a Grid-Tied Microgrid Using Solar-Wind Complementarity
Authors: Naeem Aqsa , Ul Hassan Naveed , Yuen Chau , Muyeen S. M.
Published: January 2019

The increasing use of intermittent, renewable energy sources (RESs) for electricity generation in microgrids (MGs) requires efficient strategies for reliable and economic operation. Complementarity between RESs provides good prospects for integrating several local energy sources and reducing the costs of MG setup and operations. This paper presents a framework for maximizing the economic benefits of a grid-tied MG by exploiting the spatial and temporal complementarity between solar and wind energies (solar-wind complementarity). The proposed framework considers the cost of energy production from different RESs and the cost of bi-directional energy exchange with the main grid. For a given RES mix, a minimum system power loss (SPL) threshold can also be determined. However, at this SPL threshold, MG energy exchange cost is not always minimized. The framework determines the optimized SPL value (above the threshold) at which MG energy exchange cost gets minimized. Through this framework, MG operator can decide appropriate RES mix and can achieve various tradeoffs according to the energy production cost, solar-wind complementarity of the site and its required economic objectives.
The Future Agricultural Biogas Plant in Germany: A Vision
Authors: Theuerl Susanne , Herrmann Christiane , Heiermann Monika , Grundmann Philipp , Landwehr Niels , Kreidenweis Ulrich , Prochnow Annette
Published: January 2019

After nearly two decades of subsidized and energy crop-oriented development, agricultural biogas production in Germany is standing at a crossroads. Fundamental challenges need to be met. In this article we sketch a vision of a future agricultural biogas plant that is an integral part of the circular bioeconomy and works mainly on the base of residues. It is flexible with regard to feedstocks, digester operation, microbial communities and biogas output. It is modular in design and its operation is knowledge-based, information-driven and largely automated. It will be competitive with fossil energies and other renewable energies, profitable for farmers and plant operators and favorable for the national economy. In this paper we discuss the required contribution of research to achieve these aims.
The Inhibition Effect of Gas–Solid Two-Phase Inhibitors on Methane Explosion
Authors: Wang Yan , Meng Xiangqing , Ji Wentao , Pei Bei , Lin Chendi , Feng Hao , Zheng Ligang
Published: January 2019

In order to study the inhibition effect of gas–solid two-phase inhibitors on a methane explosion, the influence of these parameters was investigated and compared with that of single-phase inhibitors. The results show that the inhibition effect of gas–solid two-phase inhibitors on a methane explosion is better than the added effect of two single-phase inhibitors, indicating that a synergistic effect can be obtained by gas–solid two-phase inhibitors. The two-phase inhibitors which are composed of NaHCO3 (BC) powders and inert gas have a better suppressing property than those composed of NH4H2PO4 (ABC) powders and inert gas. The two-phase inhibitors composed of CO2 and powders have a better suppressing property than those composed of N2 and powders. The 9.5% premixed methane–air mixture can be completely inhibited by 0.10 g/L BC powders mixed with 8% CO2. The suppression mechanisms of the gas–solid two-phase inhibitors on the methane explosion were discussed.
A Study on Improvement of Blockchain Application to Overcome Vulnerability of IoT Multiplatform Security
Authors: Kim Seong-Kyu , Kim Ung-Mo , Huh Jun-Ho
Published: January 2019

IoT devices are widely used in the smart home, automobile, and aerospace areas. Note, however, that recent information on thefts and hacking have given rise to many problems. The aim of this study is to overcome the security weaknesses of existing Internet of Things (IoT) devices using Blockchain technology, which is a recent issue. This technology is used in Machine-to-Machine (M2M) access payment—KYD (Know Your Device)—based on the reliability of existing IoT devices. Thus, this paper proposes a BoT (Blockchain of Things) ecosystem to overcome problems related to the hacking risk of IoT devices to be introduced, such as logistics management and history management. There are also many security vulnerabilities in the sensor multi-platform from the IoT point of view. In this paper, we propose a model that solves the security vulnerability in the sensor multi-platform by using blockchain technology on an empirical model. The color spectrum chain mentioned in this paper suggests a blockchain technique completed by using the multiple-agreement algorithm to enhance Thin-Plate Spline (TPS) performance and measure various security strengths. In conclusion, we propose a radix of the blockchain’s core algorithm to overcome the weaknesses of sensor devices such as automobile, airplane, and close-circuit television (CCTV) using blockchain technology. Because all IoT devices use wireless technology, they have a fundamental weakness over wired networks. Sensors are exposed to hacking and sensor multi-platforms are vulnerable to security by multiple channels. In addition, since IoT devices have a lot of security weaknesses we intend to show the authentication strength of security through the color spectrum chain and apply it to sensor and multi-platform using Blockchain in the future.
Coal Strength Development with the Increase of Lateral Confinement
Authors: Zhang Junwen , Li Yulin
Published: January 2019

The high stress environment brings many challenges in underground coal mining. In order to address the strength behavior of coal under various confining stresses and hence shed light on coal pillar design optimization, compressive tests were conducted under the lateral confinement of 0–8.0 MPa, and the strength enhancement mechanism was studied from the grain scale using PFC modeling. The results show that the coal strength and cumulative axial strain at failure increased with the confinement, while the Young’s modulus of coal is independent of confinement. However, this confinement-dependent strength property can be significantly weakened by existing cracks. Compared to the significant increase in peak compressive stress, the crack initiation stress slightly increased with the confinement. The strength component mobilized with the confinement enhancement. In the early stage of loading, the high confinement restrained the development of microcracks, while in the later stage, it enhanced the frictional resistance strength component. The two mechanism shifted the compressive strength of coal together and the latter one contributed to the strength component mobilization. The coal showed three failure modes sequentially with the increase of confinement, namely axial splitting, mixed failure and shear failure mode. With regard to failure envelope, the Mohr-Coulomb, Hoek-Brown and S-shaped failure criteria can generally represent the confinement-dependent coal strength with R-square larger than 0.9. The confinement of rapid strength promotion section of S-shape failure envelope falls in a range of 1.5–3.0 MPa. This leads to the difficulty of S-shaped failure envelope justification due to the soft nature and heterogeneity of coal.
Multi-Ejector Concept: A Comprehensive Review on its Latest Technological Developments
Authors: Gullo Paride , Hafner Armin , Banasiak Krzysztof , Minetto Silvia , Kriezi Ekaterini E.
Published: January 2019

The adoption of the EU F-Gas Regulation 517/2014 and the resulting development of the multi-ejector concept have led carbon dioxide to take center stage as the sole refrigerant (R744) in several applications. Therefore, a knock-on effect on the number of supermarkets relying on “CO2 only” refrigeration systems has been experienced. Additionally, a global consensus of commercial multi-ejector based R744 units is also intensifying as a consequence of both the promising results obtained and the other measures in force for environment preservation. Furthermore, the multi-ejector concept is expected to offer significant energy savings in other high energy-demanding buildings (e.g., hotels, gyms, spas) as well, even in warm climates. In this investigation, the evolution of R744 ejector supported parallel vapor compression system layouts for food retail applications was summed up. Furthermore, their technological aspects, the results related to the main theoretical assessments and some relevant field/laboratory measurements were summarized. Also, the experience gained in the adoption of the multi-ejector concept in transcritical R744 vapor-compression units aimed at other energy intensive applications was presented. Finally, the persistent barriers needing to be overcome as well as the required future work were brought to light.
District Cooling Versus Individual Cooling in Urban Energy Systems: The Impact of District Energy Share in Cities on the Optimal Storage Sizing
Authors: Dominković Dominik Franjo , Krajačić Goran
Published: January 2019

The energy transition of future urban energy systems is still the subject of an ongoing debate. District energy supply can play an important role in reducing the total socio-economic costs of energy systems and primary energy supply. Although lots of research was done on integrated modelling including district heating, there is a lack of research on integrated energy modelling including district cooling. This paper addressed the latter gap using linear continuous optimization model of the whole energy system, using Singapore for a case study. Results showed that optimal district cooling share was 30% of the total cooling energy demand for both developed scenarios, one that took into account spatial constraints for photovoltaics installation and the other one that did not. In the scenario that took into account existing spatial constraints for installations, optimal capacities of methane and thermal energy storage types were much larger than capacities of grid battery storage, battery storage in vehicles and hydrogen storage. Grid battery storage correlated with photovoltaics capacity installed in the energy system. Furthermore, it was shown that successful representation of long-term storage solutions in urban energy models reduced the total socio-economic costs of the energy system for 4.1%.
Study on the Coupled Dynamic Responses of a Submerged Floating Wind Turbine under Different Mooring Conditions
Authors: Le Conghuan , Li Yane , Ding Hongyan
Published: January 2019

A submerged floating offshore wind turbine (SFOWT) is proposed for intermediate water depth (50–200 m). An aero-hydro-servo-elastic-mooring coupled dynamic analysis was carried out to investigate the coupled dynamic response of the SFOWT under different mooring conditions subjected to combined turbulent wind and irregular wave environments. The effects of different parameters, namely, the tether length, pretension and the tether failure, on the performance of SFOWT were investigated. It is found that the tether length has significant effects on the motion responses of the surge, heave, pitch and yaw but has little effects on the tower fore-aft displacement and the tether tensions. The increased pretension can result in the increase of the natural frequencies of surge, heave and yaw significantly. The influence of tether failure on the SFOWT performance was investigated by comparing the responses with those of the intact mooring system. The results show that the SFOWT with a broken tether still has a good performance in the operational condition.
Mapping and Analysis of the Reactive Power Balance in the Danish Transmission Network
Authors: Nannestad Mads Øbro , Zhang Zhe , Jia Jundi , Jensen Emil Kjær , Randewijk Peter Jan
Published: January 2019

This paper investigates the reactive power balance of the Zealand side of the Danish transmission system (DK2) by using QV-curves. The study is performed in cooperation with Energinet, who is the Danish transmission system operator (TSO). Firstly, this paper aims to map the reactive power balance with the current challenges in the system, which appears due to a decision of changing overhead lines in the scenic area to cables. Secondly, a method is derived for obtaining a comprehensive overview of the impacts that future projects might have on the system. By dividing the transmission system into smaller areas, it is possible to analyze how the reactive power will affect the voltage; moreover, it is favorable to analyze and handle the challenges in the reactive power balance locally. This helps the TSO to quickly determine the lack of reactive power devices and issues that might occur in future expansions of the system. For this paper, a full-scale model of DK2 and SCADA-data has been utilized. It covers the period from 01-01-2016 to 20-08-2017 between the TSO and the Distribution System Operator (DSO). The studies have shown how the location of the wind production will create issues in the reactive power balance.
A Multi-objective Scheduling Optimization Model for Hybrid Energy System Connected with Wind-Photovoltaic-Conventional Gas Turbines, CHP Considering Heating Storage Mechanism
Authors: Wang Yao , Lu Yan , Ju Liwei , Wang Ting , Tan Qingkun , Wang Jiawei , Tan Zhongfu
Published: January 2019

In order to meet the user’s electricity demand and make full use of distributed energy, a hybrid energy system (HES) was proposed and designed, including wind turbines (WTs), photovoltaic (PV) power generation, conventional gas turbines (CGTs), incentive-based demand response (IBDR), combined heat and power (CHP) and regenerative electric (RE) boilers. Then, the collaborative operation problem of HES is discussed. First, the paper describes the HES’ basic structure and presents the output model of power sources and heating sources. Next, the maximum operating income and minimum load fluctuation are taken as the objective function, and a multi-objective model of HES scheduling is proposed. Then an algorithm for solving the model is proposed that comprises two steps: processing the objective functions and constraints into linear equations and determining the optimal weight of the objective functions. The selected simulation system is a microgrid located on an eastern island of China to comparatively analyze the influence of RE-heating storage (RE-HS) and price-based demand response (PBDR) on HES operation in relation to four cases. By analyzing the results, the following three conclusions are drawn: (1) HES can comprehensively utilize a variety of distributed energy sources to meet load demand. In particular, RE technology can convert the abandoned energy of WT and PV into heat during the valley load time, to meet the load demand combined with CHP; (2) The proposed multi-objective scheduling model of HES operation not only considers the maximum operating income but also considers the minimum load fluctuation, thus achieving the optimal balancing operation; (3) RE-HS and PBDR have a synergistic optimization effect, and when RE-HS and PBDR are both applied, an HES can achieve optimal operation results. Overall, the proposed decision method is highly effective and applicable, and decision makers could utilize this method to design an optimal HES operation strategy according to their own actual conditions.
A Distributed Demand Side Energy Management Algorithm for Smart Grid
Authors: He Min-fan , Zhang Fu-xing , Huang Yong , Chen Jian , Wang Jue , Wang Rui
Published: January 2019

This paper proposes a model predictive control (MPC) framework-based distributed demand side energy management method (denoted as DMPC) for users and utilities in a smart grid. The users are equipped with renewable energy resources (RESs), energy storage system (ESSs) and different types of smart loads. With the proposed method, each user finds an optimal operation routine in response to the varying electricity prices according to his/her own preference individually, for example, the power reduction of flexible loads, the start time of shift-able loads, the operation power of schedulable loads, and the charge/discharge routine of the ESSs. Moreover, in the method a penalty term is used to avoid large fluctuation of the user’s operation routines in two consecutive iteration steps. In addition, unlike traditional energy management methods which neglect the forecast errors, the proposed DMPC method can adapt the operation routine to newly updated data. The DMPC is compared with a frequently used method, namely, a day-ahead programming-based method (denoted as DDA). Simulation results demonstrate the efficiency and flexibility of the DMPC over the DDA method.
Life Cycle Assessment of Large-scale Compressed Bio-natural Gas Production in China: A Case Study on Manure Co-digestion with Corn Stover
Authors: Yang Yang , Ni Ji-Qin , Zhu Wanbin , Xie Guanghui
Published: January 2019

Compressed bio-natural gas (CBG) production from large-scale systems has been recognized as promising because of the abundance of manure and crop residue feedstocks and its environmental friendliness. This study is a life cycle assessment using the local database of an operating large-scale CBG system of manure co-digestion with corn stover in China and eBalance software. The results showed that the system’s Primary Energy Input to Output (PEIO) ratio was 20%. Its anaerobic digestion process was the main contributor to energy consumption, accounting for 76%. Among the six environmental impacts investigated in this study, the global warming potential (GWP) was the major environmental impact, and the digestate effluent management process was the main contributor to the GWP, accounting for 60%. The mitigation potential of the system, compared with reference case for GWP, was 3.19 kg CO2-eq for 1 m3 CBG production. In the future, the GWP mitigation could be 479 × 106 metric tons CO2-eq with 150 × 109 m3 yr−1 CBG production from the entire China. This study provides a reference on large-scale CBG production system for establishing a localized life cycle assessment inventory database in China.
Virtual Sensors to Drive Anaerobic Digestion under a Synergetic Controller
Authors: Bouchareb Hanane , Semcheddine Samia , Harmas Mohamed Naguib , M’sirdi Kouider Nacer , Naamane Aziz
Published: January 2019

A robust synergetic controller using different observers is developed to drive an anaerobic digestion biogas plant. The latter, a highly nonlinear process requires prohibitive cost sensors. Furthermore, some variables are downright immeasurable rendering control an intricate challenge. Only biogas flow which can be effectively measured, due to an easily integrated low cost sensor, will be considered available and used in this work. The proposed synergetic controller depends on immeasurable system states, thus observers will be used for state estimation. Substrate and biomass concentrations required in the synergetic control law will be obtained via three virtual sensors developed for a one stage fermentation process model. The model, used in this paper, consider the mechanization phase responsible for the biogas production because the objective is to improve the amount of methane produced. A simulation study of the biogas plant control with the proposed technique is compared to a classic PID (Proportional, Integral and Derivative) approach. Comparative studies are provided for observation and control via computer simulations.
Financial Analysis of International Energy Trade: A Strategic Outlook for EU-15
Authors: Yüksel Serhat , Dinçer Hasan , Meral Yurdagül
Published: January 2019

This study aims to analyse the international energy trade in EU-15. Within this context, 6 items of international transport and energy trade have been selected to evaluate the performance of European Union (EU) 15 countries. For this purpose, a comparative analysis has been applied by including and excluding the data of energy trade in international transport for the years between 2013 and 2016. In this framework, interval type-2 fuzzy decision-making trial and evaluation laboratory (DEMATEL) and technique for order preference by similarity to ideal solution (TOPSIS) approaches are considered. The findings show that road and sea have the highest importance for international transport and energy trade. However, pipeline and electricity, which represent the energy trade, take place on the last ranks. Another important conclusion is that there is almost no difference in the ranking of international transport performance including and excluding energy trade. While considering these issues, it is recommended that that European countries should take some actions to increase the energy production. The main reason is that it has a positive influence on both international trade volume and industrial production. Thus, they can focus on renewable energy production which leads to lower cost in this process.
A Novel Direct-Drive Permanent Magnet Synchronous Motor with Toroidal Windings
Authors: Gao Caixia , Gao Mengzhen , Si Jikai , Hu Yihua , Gan Chun
Published: January 2019

A direct-drive motor has the merits of low speed, high torque, and elimination of mechanical deceleration mechanisms, and is widely used in various fields. A novel direct-drive permanent magnet synchronous motor is presented herein, in which all coils are wrapped around the stator yoke in the same orientation. The structure of the novel direct-drive permanent magnet synchronous motor with toroidal windings (N-TWDDPMSM) is introduced and its operating principle is analyzed by describing the variation in the armature magnet field versus time. Furthermore, based on the same power grade and mechanical size, several finite-element models of motors with different windings are established using Magnet software to analyze the distribution of magnetic field, back-electromotive force (back-EMF), power-angle characteristics, loss characteristics, etc. Compared with the traditional permanent magnet synchronous motor (T-PMSM), the traditional permanent magnet synchronous motor with toroidal windings (T-TWPMSM), and the N-TWDDPMSM, the N-TWDDPMSM shows advantages of low speed and high torque, and the feasibility and superiority of the N-TWDDPMSM are verified.
Biogas Production by Co-Digestion of Canteen Food Waste and Domestic Wastewater under Organic Loading Rate and Temperature Optimization
Authors: Rattanapan Cheerawit , Sinchai Lalita , Tachapattaworakul Suksaroj Thunwadee , Kantachote Duangporn , Ounsaneha Weerawat
Published: February 2019

The objective of this study was to characterize biogas production performance from the co-digestion of food waste and domestic wastewater under mesophilic (35 ± 1 °C) and thermophilic (55 ± 1 °C) conditions. The food waste used as a co-substrate in this study was collected from a main canteen at the Hatyai campus of Prince of Songkla University, Songkhla Province, Thailand. The optimum co-digestion ratio and temperature conditions in a batch experiment were selected for a semi-continuous experiment. Organic loading rates (OLRs) of 0.66, 0.33, and 0.22 g volatile solid (VS) L−1 d−1 were investigated in a semi-continuous experiment by continuously stirring a tank reactor (CSTR) for biogas production. The highest biomethane potential (BMP, 0.78 ml CH4 mg−1 VS removal) was achieved with a ratio of food waste to domestic wastewater of 10:90 w/v at a mesophilic temperature. An OLR of 0.22 g VS L−1 d−1 of co-digestion yielded positive biogas production and organic removal. The findings of this study illustrate how biogas production can be used for operating feed conditions and control for anaerobic co-digestion of domestic wastewater and food waste from a university canteen.
De Novo Transcriptome Analysis of Dalbergia odorifera T. Chen (Fabaceae) and Transferability of SSR Markers Developed from the Transcriptome
Authors: Liu Fu-Mei , Hong Zhou , Yang Zeng-Jiang , Zhang Ning-Nan , Liu Xiao-Jin , Xu Da-Ping
Published: January 2019

Dalbergia odorifera T. Chen (Fabaceae), indigenous to Hainan Island, is a precious rosewood (Hainan hualimu) in China. However, only limited genomic information is available which has resulted in a lack of molecular markers, limiting the development and utilization of the germplasm resources. In this study, we aim to enrich genomic information of D. odorifera, and develop a series of transferable simple sequence repeat (SSR) markers for Dalbergia species. Therefore, we performed transcriptome sequencing for D. odorifera by pooling leaf tissues from three trees. A dataset of 138,516,418 reads was identified and assembled into 115,292 unigenes. Moreover, 35,774 simple sequence repeats (SSRs) were identified as potential SSR markers. A set of 19 SSR markers was successfully transferred across species of Dalbergia odorifera T. Chen, Dalbergia tonkinensis Prain, and Dalbergia cochinchinensis Pierre ex Laness. In total, 112 alleles (3–13 alleles/locus) were presented among 60 Dalbergia trees, and polymorphic information content ranged from 0.38 to 0.75. The mean observed and mean expected heterozygosity was 0.34 and 0.40 in D. odorifera, 0.27 and 0.32 in D. tonkinensis, and 0.29 and 0.33 in D. cochinchinensis, respectively. The cluster analysis classified these 60 trees into three major groups according to the three Dalbergia species based on the genetic similarity coefficients, indicating these newly developed transferable markers can be used to explore the relationships among Dalbergia species and assist genetic research. All these unigenes and SSR markers will be useful for breeding programs in the future.
Bioenergy Production on Degraded Land: Landowner Perceptions in Central Kalimantan, Indonesia
Authors: Artati Yustina , Jaung Wanggi , Juniwaty Kartika Sari , Andini Sarah , Lee Soo Min , Segah Hendrik , Baral Himlal
Published: January 2019

Bioenergy production from degraded land provides an opportunity to secure a new renewable energy source to meet the rapid growth of energy demand in Indonesia while turning degraded land into productive landscape. However, bioenergy production would not be feasible without landowner participation. This study investigates factors affecting landowners’ preferences for bioenergy production by analyzing 150 landowners with fire experience in Buntoi village in Central Kalimantan using Firth’s logistic regression model. Results indicated that 76% of landowners preferred well-known species that have a readily available market such as sengon (Albizia chinensis (Osb.) Merr.) and rubber tree (Hevea brasiliensis Müll.Arg.) for restoration on degraded land. Only 8% of preferred nyamplung (Calophyllum inophyllum L.) for bioenergy production; these particular landowners revealed a capacity to handle the uncertainty of the bioenergy market because they had additional jobs and income, had migrated from Java where nyamplung is prevalent, and preferred agricultural extension to improve their technical capacity. These results contribute to identifying key conditions for a bottom-up approach to bioenergy production from degraded land in Indonesia: a stable bioenergy market for landowners, application of familiar bioenergy species, and agricultural extension support for capacity building.
Diversity and Genetic Structure Inferred with Microsatellites in Natural Populations of Pseudotsuga menziesii (Mirb.) Franco (Pinaceae) in the Central Region of Mexico
Authors: Montiel Castelán Paulina , Cortés-Cruz Moisés , Mendoza-Castillo Ma. , Cruz-Izquierdo Serafín , López-Upton Javier , Sandoval Padilla Isaac , Guerra de la Cruz Vidal
Published: January 2019

The amount and structure of the genetic diversity in Mexican populations of Pseudotsuga menziesii (Mirb.) Franco, is almost unknown, since most genetic studies have been carried out on populations from Canada and the United States. Here, we applied a set of 12 microsatellite markers to 12 populations (234 trees) from the central region of Mexico in order to determine values of genetic diversity and differentiation. Seventy-three different alleles were identified: an average number of alleles per locus (Na) of 6.083, effective number of alleles (Ne) of 2.039, observed heterozygosity (Ho) of 0.229, and expected heterozygosity (Ht) of 0.417. Genetic differentiation was high: the coefficient of differentiation (θ) was 0.270, while the coefficient of structure (Φst) was 0.278. Bayesian analysis identified two genetic groups in central Mexico. The PCoA and the dendrogram were in concordance with the two genetic groups. The results of the analysis of molecular variance (AMOVA) indicate that genetic variation exists mainly within populations (72.149%). Therefore, conservation efforts should focus on as many individuals within populations as possible, to maintain this variation.
Effects of Sucrose, Boric Acid, pH, and Incubation Time on in Vitro Germination of Pollen and Tube Growth of Chinese fir (Cunnighamial lanceolata L.)
Authors: Fragallah Seif Aldin Dawina Abdallah , Lin Sizu , Li Nuo , Ligate Elly Josephat , Chen Yu
Published: January 2019

In vitro pollen germination provides a novel approach and strategy to accelerate genetic improvement of tree breeding. Studies about pollen germination and tube growth of Chinese fir are limited. Therefore, this study aimed to investigate the effects of sucrose, boric acid, pH, and time of incubation on pollen germination and tube growth. Pollen from 9 clones were selected. In vitro germination was performed in basic media as control, and in different concentrations of sucrose (0, 10 and 15%), boric acid (0.01, 0.1 and 0.2%), and pH levels (4.5, 5 and 7). Pollen germination rates and tube growth were recorded periodically at 1, 12, 24, and 48 h. The results showed that sucrose imposes significant effects on pollen germination and tube growth. The effects are most obvious at concentration of 15%. Boric acid significantly promoted germination and tube growth. The promotion was most notable in lower concentration of 0.01%. The media adjusted to pH 7.0 boosted the germination and pollen tube growth. The optimum time of incubation was 24 and 48 h for pollen germination and tube growth, respectively. Sucrose, pH, and time of incubation were positively correlated, whereas boric acid negatively correlated with pollen germination and tube growth. This study provided experimental evidences for selecting viable pollens for Chinese fir breeding.
Soil Fungal Community in Norway Spruce Forests under Bark Beetle Attack
Authors: Veselá Petra , Vašutová Martina , Edwards-Jonášová Magda , Cudlín Pavel
Published: January 2019

Bark beetle infestation is a widespread phenomenon in temperate forests, which are facing significant weather fluctuations accompanying climate change. Fungi play key roles in forest ecosystems as symbionts of ectomycorrhizal trees, decomposers, or parasites, but the effect of severe disturbances on their communities is largely unknown. The responses of soil fungal communities following bark beetle attack were determined using Illumina sequencing of soil samples from 10 microsites in a mature forest not attacked by bark beetle, a forest attacked by bark beetle, a forest destroyed by bark beetle, and a stand where all trees were removed after a windstorm. The proportion of ITS2 sequences assigned to mycorrhizal fungal species decreased with increased intensity of bark beetle attack (from 70 to 15%), whereas the proportion of saprotrophs increased (from 29 to 77%). Differences in the ectomycorrhizal (ECM) fungal community was further characterized by a decrease in the sequence proportion of Elaphomyces sp. and Russula sp. and an increase in Piloderma sp., Wilcoxina sp., and Thelephora terrestris. Interestingly, the species composition of the ECM fungal community in the forest one year after removing the windstorm-damaged trees was similar to that of the mature forest, despite the sequence proportion attributed to ECM fungi decreased.
A Continuum Model for Complex Flows of Shear Thickening Colloidal Solutions
Authors: Green Joseph A. , Ryckman Daniel J. , Cromer Michael
Published: February 2019

Colloidal shear thickening fluids (STFs) have applications ranging from commercial use to those of interest to the army and law enforcement, and the oil industry. The theoretical understanding of the flow of these particulate suspensions has predominantly been focused through detailed particle simulations. While these simulations are able to accurately capture and predict the behavior of suspensions in simple flows, they are not tractable for more complex flows such as those occurring in applications. The model presented in this work, a modification of an earlier constitutive model by Stickel et al. J. Rheol. 2006, 50, 379–413, describes the evolution of a structure tensor, which is related to the particle mean free-path length. The model contains few adjustable parameters, includes nonlinear terms in the structure, and is able to predict the full range of rheological behavior including shear and extensional thickening (continuous and discontinuous). In order to demonstrate its capability for complex flow simulations, we compare the results of simulations of the model in a simple one-dimensional channel flow versus a full two-dimensional simulation. Ultimately, the model presented is a continuum model shown to predict shear and extensional thickening, as observed in experiment, with a connection to the physical microstructure, and has the capability of helping understand the behavior of STFs in complex flows.
Example of a Finite Game with No Berge Equilibria at All
Authors: Pykacz Jarosław , Bytner Paweł , Frąckiewicz Piotr
Published: January 2019

The problem of the existence of Berge equilibria in the sense of Zhukovskii in normal-form finite games in pure and in mixed strategies is studied. The example of a three-player game that has Berge equilibrium neither in pure, nor in mixed strategies is given.
Correction: Marques, A. et al. Evolution of Plant B Chromosome Enriched Sequences. Genes 2018, 9, 515
Authors: Marques André , Klemme Sonja , Houben Andreas
Published: January 2019

The authors wish to make the following modification in their review [...]
Determination of Genetic Effects of LIPK and LIPJ Genes on Milk Fatty Acids in Dairy Cattle
Authors: Shi Lijun , Han Bo , Liu Lin , Lv Xiaoqing , Ma Zhu , Li Cong , Xu Lingna , Li Yanhua , Zhao Feng , Yang Yuze , Sun Dongxiao
Published: January 2019

In our previous genome-wide association study (GWAS) on milk fatty acids (FAs) in Chinese Holstein, we discovered 83 genome-wide significant single nucleotide polymorphisms (SNPs) associated with milk FAs. Two of them were close to lipase family member K (LIPK) and lipase family member J (LIPJ), respectively. Hence, this study is a follow-up to verify whether the LIPK and LIPJ have significant genetic effects on milk FAs in dairy cattle. By re-sequencing the entire exons, and 3 kb of 5′ and 3′ flanking regions, two and seven SNPs were identified in LIPK and LIPJ, respectively, including a novel SNP, ss158213049726. With the Haploview 4.1 software, we found that five of the SNPs in LIPJ formed a haplotype block (D′ = 0.96 ~ 1.00). Single-locus association analyses revealed that each SNP in LIPK and LIPJ was significantly associated with at least one milk FA (p = < 1.00 × 10−4 ~ 4.88 × 10−2), and the haplotype-based association analyses showed significant genetic effects on nine milk FAs (p = < 1.00 × 10−4 ~ 3.98 × 10−2). Out of these SNPs, the missense mutation in LIPK gene, rs42774527, could change the protein secondary structure and function predicted by SOPMA, SIFT, and PROVEAN softwares. With the Genomatix software, we predicted that two SNPs, rs110322221 in LIPK and rs211373799 in LIPJ, altered the transcription factors binding sites (TFBSs), indicating their potential regulation on promoter activity of the genes. Furthermore, we found that both LIPK and LIPJ had relatively high expressions in the mammary gland. In conclusion, our research is the first to demonstrate that LIPK and LIPJ genes have significant associations with milk FAs, and the identified SNPs might be served as genetic markers to optimize breeding programs for milk FAs in dairy cattle. This research deserves in-depth verification.