bluuebunny/crossref_metadata_2025 huggingface dataset:
MENCARI FILOSOFI DI DUNIA KONTEMPORER DAN DI LINGKUNGAN AKADEMIS: SEBUAH OPINI
Authors: Dodi Sukmayadi
Published: January 2020

This paper posits an opinion that the state of philosophy in contemporary world including in academic milieu is quiet unsatisfying in terms of how it is formulated and perceived. Though only lightly touched here and there, similar situation happens in Indonesia. Philosophy has been notoriously accused of corrupting young generations, of continuously irritating establishments, or at best leaves the world unchanged. Con-sidering that even music, for example, which satisfies only a few human sense, could have such enormous effect to human life, philosophy which claims to cover all traces of human existence could basically do something much much more, rather than simply uninfluencial or harming humanity. By elucidating initial and a little further meaning of philosophy, this paper try to build a foundation for such claim. In between such elucidation, it is briefly mentioned certain reasons why philosophy has been, is and will exist as long as human being exist. All in all, however, this article is only a beginning or at least the first part to explain the existensial nature of philosophy. A further article is needed to expound that.
Dukungan Sosial Berhubungan Dengan Self Care Management Pada Lansia Hipertensi Di Puskesmas Sedayu II
Authors: Mahfud Mahfud , Barasila Bari , Indrayani Sofyan
Published: January 2020

Latar Belakang: Dukungan sosial dapat meningkatkan pengetahuan dan menstabilkan emosional pada pasien hipertensi.Untuk menjaga dan mengatasi hipertensi pada lansia perlu dilakukan dukungan sosial dengan self care managemen hipertensi.Tujuan Penelitian: Tujuan penelitian ini bertujuan untuk mengetahui hubungan dukungan sosial dengan self care manegement pada lansia hipertensi di Puskesmas Sedayu II Bantul Yogyakarta. Penelitian ini merupakan penelitian kuantitatif dengan rancangan penelitian cross sectional. Populasi dalam penelitian ini adalah lansia di Puskesmas  Sedayu II Kabupaten Bantul  yang berjumlah 45 orang.Metode: Instrumen penelitian menggunakan kuesioner dukungan sosial dan kuisioner self care management. Pengolahan data menggunakan uji statistik fisher’s Exact Test.Hasil Penelitian: Didapatkan bahwa dukungan sosial masuk dalam kategori baik yaitu.29 responden (70,7%), sedangkan self care management masuk dalam kategori baik yaitu 28 (69,3%). Hasil penelitian diperoleh nilai dukungan sosial dengan self care management hipertensi dengan p=0,000 dengan nilai keeratan hubungan  koefisien korelasi = 0,514 kategori sedang.Kesimpulan: Ada hubungan antara dukungan sosial dengan self care management pada lansia hipertensi di Puskesmas Sedayu II Bantul Yogyakarta dengan nilai signifikan 0,000 (p00.5).Kata Kunci: Dukungan sosial, self care management, lansia hipertensiBackground: Social support can increase knowledge and emotional stability in hypertensive patients. To maintain and overcome hypertension in the elderly, social support with self care management of hypertension needs to be done.Research Objectives: The purpose of this study aims to determine the relationship of social support with self care management in hypertensive elderly at Puskesmas Sedayu II Bantul Yogyakarta. This research is a quantitative study with cross sectional study design. The population in this study is the elderly in Puskesmas Sedayu II, Bantul Regency with a total of 45 people.Method: The research instrument used a social support questionnaire and a self care management questionnaire. Data processing using statistical fisher's Exact Test.Results: It was found that social support was included in the good category, 29 respondents (70.7%), while self care management was included in the good category, 28 (69.3%). The results obtained by the value of social support with hypertension self care management with p = 0,000 with the value of the correlation coefficient correlation = 0.514 medium category.Conclusion: There is a relationship between social support and self care management in hypertensive elderly in Puskesmas Sedayu II Bantul Yogyakarta with a significant value of 0,000 (p 00.5).Keywords: Social support, self care management, elderly hypertension
Active Disturbance Compensation Based Robust Control for Speed Regulation System of Permanent Magnet Synchronous Motor
Authors: Ma Yuxiang , Li Yunhua
Published: January 2020

This paper deals with the robust control method for permanent magnet synchronous motor (PMSM) speed-regulation system based on active disturbance compensation. Different from the classical PMSM disturbance compensation scheme, a novel disturbance feed-forward compensation based on extended state observer (ESO) is designed for speed loop and q-axis current loop of PMSM. The disturbances of current loop include unmodeled dynamics of back electromotive force and parameters variations of stator are considered as lumped disturbance to compensate actively. In this way, the dynamic response of q-axis current loop can be improved to guarantee the anti-disturbance ability. A composite controller using sliding mode control and ESO is designed as speed loop controller, and an ESO-based proportional-integral controller is designed for q-axis current loop. Moreover, a transition process of reference signal is introduced to replace the step reference signal, which reduces the initial error and increases the range of feedback gain to improve system robustness. Finally, simulations and experiments are given to demonstrate the effectiveness of the proposed strategy.
The Significance of Wind Turbines Layout Optimization on the Predicted Farm Energy Yield
Authors: Al-Addous Mohammad , Jaradat Mustafa , Albatayneh Aiman , Wellmann Johannes , Al Hmidan Sahil
Published: January 2020

Securing energy supply and diversifying the energy sources is one of the main goals of energy strategy for most countries. Due to climate change, wind energy is becoming increasingly important as a method of CO2-free energy generation. In this paper, a wind farm with five turbines located in Jerash, a city in northern Jordan, has been designed and analyzed. Optimization of wind farms is an important factor in the design stage to minimize the cost of wind energy to become more competitive and economically attractive. The analyses have been carried out using the WindFarm software to examine the significance of wind turbines’ layouts (M, straight and arch shapes) and spacing on the final energy yield. In this research, arranging the turbines facing the main wind direction with five times rotor diameter distance between each turbine has been simulated, and has resulted in 22.75, 22.87 and 21.997 GWh/year for the M shape, Straight line and Arch shape, respectively. Whereas, reducing the distance between turbines to 2.5 times of the rotor diameter (D) resulted in a reduction of the wind farm energy yield to 22.68, 21.498 and 21.5463 GWh/year for the M shape, Straight line and Arch shape, respectively. The energetic efficiency gain for the optimized wind turbines compared to the modeled layouts regarding the distances between the wind turbines. The energetic efficiency gain has been in the range between 8.9% for 5D (rotor diameter) straight layout to 15.9% for 2.5D straight layout.
Autophagy Inhibition Induces the Secretion of Macrophage Migration Inhibitory Factor (MIF) with Autocrine and Paracrine Effects on the Promotion of Malignancy in Breast Cancer
Authors: Cotzomi-Ortega Israel , Rosas-Cruz Arely , Ramírez-Ramírez Dalia , Reyes-Leyva Julio , Rodriguez-Sosa Miriam , Aguilar-Alonso Patricia , Maycotte Paola
Published: January 2020

Breast cancer is the main cause of cancer-related death in women in the world. Because autophagy is a known survival pathway for cancer cells, its inhibition is currently being explored in clinical trials for treating several types of malignancies. In breast cancer, autophagy has been shown to be necessary for the survival of cancer cells from the triple negative subtype (TNBC), which has the worst prognosis among breast cancers and currently has limited therapeutic options. Autophagy has also been involved in the regulation of protein secretion and, of importance for this work, the inhibition of autophagy is known to promote the secretion of proinflammatory cytokines from distinct cell types. We found that the inhibition of autophagy in TNBC cell lines induced the secretion of the macrophage migration inhibitory factor (MIF), a pro-tumorigenic cytokine involved in breast cancer invasion and immunomodulation. MIF secretion was dependent on an increase in reactive oxygen species (ROS) induced by the inhibition of autophagy. Importantly, MIF secreted from autophagy-deficient cells increased the migration of cells not treated with autophagy inhibitors, indicating that autophagy inhibition in cancer cells promoted malignancy in neighboring cells through the release of secreted factors, and that a combinatorial approach should be evaluated for cancer therapy.
Motor Program Transformation of Throwing Dart from the Third-Person Perspective
Authors: Tumialis Alexey , Smirnov Alexey , Fadeev Kirill , Alikovskaia Tatiana , Khoroshikh Pavel , Sergievich Alexander , Golokhvast Kirill
Published: January 2020

The perspective of perceiving one’s action affects its speed and accuracy. In the present study, we investigated the change in accuracy and kinematics when subjects throw darts from the first-person perspective and the third-person perspective with varying angles of view. To model the third-person perspective, subjects were looking at themselves as well as the scene through the virtual reality head-mounted display (VR HMD). The scene was supplied by a video feed from the camera located to the up and 0, 20 and 40 degrees to the right behind the subjects. The 28 subjects wore a motion capture suit to register their right hand displacement, velocity and acceleration, as well as torso rotation during the dart throws. The results indicated that mean accuracy shifted in opposite direction with the changes of camera location in vertical axis and in congruent direction in horizontal axis. Kinematic data revealed a smaller angle of torso rotation to the left in all third-person perspective conditions before and during the throw. The amplitude, speed and acceleration in third-person condition were lower compared to the first-person view condition, before the peak velocity of the hand in the direction toward the target and after the peak velocity in lowering the hand. Moreover, the hand movement angle was smaller in the third-person perspective conditions with 20 and 40 angle of view, compared with the first-person perspective condition just preceding the time of peak velocity, and the difference between conditions predicted the changes in mean accuracy of the throws. Thus, the results of this study revealed that subject’s localization contributed to the transformation of the motor program.
Preparation of Activated Carbon from Coffee Waste as an Adsorbent for the Removal of Chromium (III) from Water. Optimization for an Experimental Box-Behnken Design
Authors: Obaya Valdivia Adolfo , Montaño Osorio Carlos , Vargas Rodríguez Yolanda
Published: January 2020

Coffee grounds are an organic waste consisting of the ground, roasted and processed grain for the extraction of coffee, being of great volume the waste obtained, which, if not treated and preserved for a long time, emanates unpleasant aromas and becomes an optimal means for the proliferation of flies, and other pests. Activated carbon has the characteristic of being a material that has a large surface area; because of this, it is used in adsorption, which refers to the retention of atoms, ions, and molecules on its surface. In this paper, the production of activated carbon is presented by means of the physicochemical activation of coffee waste by calcining at 900 °C and subsequent activation with sulfuric acid, as well as the Box–Behnken design of three factors for chromium (III) adsorption optimization. It is determined that the optimal conditions for performing the adsorption are pH = 3 and a contact time of 140 min. According to the analysis of variance for the experimental design, it is determined that the initial chromium formation is not significant for the adsorption process. Under the optimal adsorb conditions of 96%, an application is given to the erasure of coffee for the production of activated carbon, which serves as the adsorbent agent applied to the removal of chromium (III) aqueous. The area of activated carbon obtained is 13657.89 ± 251.09 m2/g determined by the acetic acid adsorption isotherm method.
Perspective: Daylight Saving Time—An Advocacy for a Balanced View and against Fanning Fear
Authors: Blume Christine , Schabus Manuel
Published: January 2020

As experts, scientists must inform the public and political actors about relevant topics by providing a well-balanced analysis and overview of existing as well as missing scientific evidence. Particularly in cases where evidence is not solid, they must remain objective and not fan fear. Maintaining good scientific practice can be challenging, especially when a debate is emotionally charged and simple answers for complex issues are demanded. Recently, this was the case with the debate about (perennial) standard time vs. daylight saving time. In this publication, we address the common misconceptions and pitfalls for good scientific practice that accompany this discussion and deduce suggestions for future directions, which may help resolve them. Beyond this, we argue that it is not wise to simply “explain away” the public opinion or preference and we therefore recommend strategies that could support a discourse aiming at getting the public “on board”. Finally, we suggest that, in societies where the light environment is becoming increasingly complex, it may be time to reconsider the prevailing current relationships between solar and social clocks.
Effect of Zr Target Current on the Mechanical and Tribological Performance of MoS2–Zr Composite Lubricating Coatings
Authors: Song Wenlong , Xia Zixiang , Wang Shoujun , Zhang Qingge
Published: January 2020

To improve the tribological properties of pure MoS2 coating, the MoS2–Zr composite lubricating coatings were prepared on the WC/TiC/Co carbide surface utilizing radio frequency magnetron sputtering method combining with multiple arc ion plating technology. The effects of different Zr target currents on the surface morphologies, roughness, Zr content, adhesive force, thickness, microhardness and tribological behaviors of the composite coatings were systematically investigated. Results showed that the properties of MoS2 coating can be remarkably enhanced through co-deposition of a certain amount of Zr. As the Zr target current increased, the Zr content, surface roughness, thickness, and micro-hardness gradually increased, while the adhesive force of coatings increased first and then decreased. The friction behaviors and wear modes of the composite coatings both varied obviously with the increase of Zr current. The mechanism was mainly attributed to the different components and mechanical properties of the coatings caused by various Zr current.
Acknowledgement to Reviewers of Colloids and Interfaces in 2019
Authors:   Colloids and Interfaces Editorial Office
Published: January 2020

The editorial team greatly appreciates the reviewers who have dedicated their considerable time and expertise to the journal’s rigorous editorial process over the past 12 months, regardless of whether the papers are finally published or not [...]
Features of the Behavior of the Barocaloric Effect near Ferroelectric Phase Transition Close to the Tricritical Point
Authors: Mikhaleva E.A. , Flerov I.N. , Gorev M.V. , Bondarev V.S. , Bogdanov E.V.
Published: January 2020

A detailed study of the effect of temperature and pressure on heat capacity, entropy and hysteresis phenomena near the ferroelectric phase transition in ammonium sulfate (AS) was performed. An analysis of experimental results within the framework of the phenomenological theory showed that taking into account the temperature-dependent part of the anomalous entropy leads to a significant increase in the barocaloric effect (BCE). The maximum values of extensive and intensive BCE near the tricritical point are outstanding: Δ S B C E m a x ≈ 85 J/kgK, Δ T A D m a x ≈ 12 K and can be achieved at low pressure ∼0.5 GPa.
Creep of Heusler-Type Alloy Fe-25Al-25Co
Authors: Dobeš Ferdinand , Dymáček Petr , Friák Martin
Published: January 2020

Creep of an alloy based on the intermetallic compound Fe2AlCo was studied by compressive creep tests in the temperature range from 873 to 1073 K. The stress exponent n and the activation energy of creep Q were determined using the multivariable regression of the creep-rate data and their description by means of sinh equation (Garofalo equation). The evaluated stress exponents indicate that the dislocation climb controls creep deformation. The estimated apparent activation energies for creep are higher than the activation enthalpy for the diffusion of Fe in Fe3Al. This can be ascribed to the changes in crystal lattice and changing microstructure of the alloy.
Visual Analysis on Information Theory and Science of Complexity Approaches in Healthcare Research
Authors: Wang Xiaoyu , Zhao Wang , Wang Yongzhong , Zhao Qin , Yang Xuejie , Su Kaixiang , Gu Dongxiao
Published: January 2020

In order to explore the knowledge base, research hotspot, development status, and future research direction of healthcare research based on information theory and complex science, a total of 3031 literature data samples from the core collection of Web of Science from 2003 to 2019 were selected for bibliometric analysis. HistCite, CiteSpace, Excel, and other analytical tools were used to deeply analyze and visualize the temporal distribution, spatial distribution, knowledge evolution, literature co-citation, and research hotspots of this field. This paper reveals the current development of healthcare research field based on information theory and science of complexity, analyzes and discusses the research hotspots and future development that trends in this field, and provides important knowledge support for researchers in this field for further relevant research.
Energy and Exergy Evaluation of a Two-Stage Axial Vapour Compressor on the LNG Carrier
Authors: Poljak Igor , Orović Josip , Mrzljak Vedran , Bernečić Dean
Published: January 2020

Data from a two-stage axial vapor cryogenic compressor on the dual-fuel diesel–electric (DFDE) liquefied natural gas (LNG) carrier were measured and analyzed to investigate compressor energy and exergy efficiency in real exploitation conditions. The running parameters of the two-stage compressor were collected while changing the main propeller shafts rpm. As the compressor supply of vaporized gas to the main engines increases, so does the load and rpm in propulsion electric motors, and vice versa. The results show that when the main engine load varied from 46 to 56 rpm at main propulsion shafts increased mass flow rate of vaporized LNG at a two-stage compressor has an influence on compressor performance. Compressor average energy efficiency is around 50%, while the exergy efficiency of the compressor is significantly lower in all measured ranges and on average is around 34%. The change in the ambient temperature from 0 to 50 °C also influences the compressor’s exergy efficiency. Higher exergy efficiency is achieved at lower ambient temperatures. As temperature increases, overall compressor exergy efficiency decreases by about 7% on average over the whole analyzed range. The proposed new concept of energy-saving and increasing the compressor efficiency based on pre-cooling of the compressor second stage is also analyzed. The temperature at the second stage was varied in the range from 0 to −50 °C, which results in power savings up to 26 kW for optimal running regimes.
Permutation Entropy and Statistical Complexity in Mild Cognitive Impairment and Alzheimer’s Disease: An Analysis Based on Frequency Bands
Authors: Echegoyen Ignacio , López-Sanz David , Martínez Johann H. , Maestú Fernando , Buldú Javier M.
Published: January 2020

We present one of the first applications of Permutation Entropy (PE) and Statistical Complexity (SC) (measured as the product of PE and Jensen-Shanon Divergence) on Magnetoencephalography (MEG) recordings of 46 subjects suffering from Mild Cognitive Impairment (MCI), 17 individuals diagnosed with Alzheimer’s Disease (AD) and 48 healthy controls. We studied the differences in PE and SC in broadband signals and their decomposition into frequency bands ( δ , θ , α and β ), considering two modalities: (i) raw time series obtained from the magnetometers and (ii) a reconstruction into cortical sources or regions of interest (ROIs). We conducted our analyses at three levels: (i) at the group level we compared SC in each frequency band and modality between groups; (ii) at the individual level we compared how the [PE, SC] plane differs in each modality; and (iii) at the local level we explored differences in scalp and cortical space. We recovered classical results that considered only broadband signals and found a nontrivial pattern of alterations in each frequency band, showing that SC does not necessarily decrease in AD or MCI.
Entropy-Based Image Fusion with Joint Sparse Representation and Rolling Guidance Filter
Authors: Liu Yudan , Yang Xiaomin , Zhang Rongzhu , Albertini Marcelo Keese , Celik Turgay , Jeon Gwanggil
Published: January 2020

Image fusion is a very practical technology that can be applied in many fields, such as medicine, remote sensing and surveillance. An image fusion method using multi-scale decomposition and joint sparse representation is introduced in this paper. First, joint sparse representation is applied to decompose two source images into a common image and two innovation images. Second, two initial weight maps are generated by filtering the two source images separately. Final weight maps are obtained by joint bilateral filtering according to the initial weight maps. Then, the multi-scale decomposition of the innovation images is performed through the rolling guide filter. Finally, the final weight maps are used to generate the fused innovation image. The fused innovation image and the common image are combined to generate the ultimate fused image. The experimental results show that our method’s average metrics are: mutual information ( M I )—5.3377, feature mutual information ( F M I )—0.5600, normalized weighted edge preservation value ( Q A B / F )—0.6978 and nonlinear correlation information entropy ( N C I E )—0.8226. Our method can achieve better performance compared to the state-of-the-art methods in visual perception and objective quantification.
Generalized Independence in the q-Voter Model: How Do Parameters Influence the Phase Transition?
Authors: Abramiuk Angelika , Sznajd-Weron Katarzyna
Published: January 2020

We study the q-voter model with flexibility, which allows for describing a broad spectrum of independence from zealots, inflexibility, or stubbornness through noisy voters to self-anticonformity. Analyzing the model within the pair approximation allows us to derive the analytical formula for the critical point, below which an ordered (agreement) phase is stable. We determine the role of flexibility, which can be understood as an amount of variability associated with an independent behavior, as well as the role of the average network degree in shaping the character of the phase transition. We check the existence of the scaling relation, which previously was derived for the Sznajd model. We show that the scaling is universal, in a sense that it does not depend neither on the size of the group of influence nor on the average network degree. Analyzing the model in terms of the rescaled parameter, we determine the critical point, the jump of the order parameter, as well as the width of the hysteresis as a function of the average network degree ⟨ k ⟩ and the size of the group of influence q.
Green Synthetic Fuels: Renewable Routes for the Conversion of Non-Fossil Feedstocks into Gaseous Fuels and Their End Uses
Authors: Rozzi Elena , Minuto Francesco Demetrio , Lanzini Andrea , Leone Pierluigi
Published: January 2020

Innovative renewable routes are potentially able to sustain the transition to a decarbonized energy economy. Green synthetic fuels, including hydrogen and natural gas, are considered viable alternatives to fossil fuels. Indeed, they play a fundamental role in those sectors that are difficult to electrify (e.g., road mobility or high-heat industrial processes), are capable of mitigating problems related to flexibility and instantaneous balance of the electric grid, are suitable for large-size and long-term storage and can be transported through the gas network. This article is an overview of the overall supply chain, including production, transport, storage and end uses. Available fuel conversion technologies use renewable energy for the catalytic conversion of non-fossil feedstocks into hydrogen and syngas. We will show how relevant technologies involve thermochemical, electrochemical and photochemical processes. The syngas quality can be improved by catalytic CO and CO2 methanation reactions for the generation of synthetic natural gas. Finally, the produced gaseous fuels could follow several pathways for transport and lead to different final uses. Therefore, storage alternatives and gas interchangeability requirements for the safe injection of green fuels in the natural gas network and fuel cells are outlined. Nevertheless, the effects of gas quality on combustion emissions and safety are considered.
Collective Renewable Energy Prosumers and the Promises of the Energy Union: Taking Stock
Authors: Horstink Lanka , Wittmayer Julia M. , Ng Kiat , Luz Guilherme Pontes , Marín-González Esther , Gährs Swantje , Campos Inês , Holstenkamp Lars , Oxenaar Sem , Brown Donal
Published: January 2020

A key strategy in the European Union’s ambition to establish an ‘Energy Union’ that is not just clean, but also fair, consists of empowering citizens to actively interact with the energy market as self-consumers or prosumers. Although renewable energy sources (RES) prosumerism has been growing for at least a decade, two new EU directives are intended to legitimise and facilitate its expansion. However, little is known about the full range of prosumers against which to measure policy effectiveness. We carried out a documentary study and an online survey in nine EU countries to shed light on the demographics, use of technology, organisation, financing, and motivation as well as perceived hindering and facilitating factors for collective prosumers. We identified several internal and external obstacles to the successful mainstreaming of RES prosumerism, among them a mismatch of policies with the needs of different RES prosumer types, potential organisational weaknesses as well as slow progress in essential reforms such as decentralising energy infrastructures. Our baseline results offer recommendations for the transposition of EU directives into national legislations and suggest avenues for future research in the fields of social, governance, policy, technology, and business models.
Characteristic Analysis of Torrefied Pellets: Determining Optimal Torrefaction Conditions for Agri-Byproduct
Authors: Park Sunyong , Kim Seok Jun , Oh Kwang Cheol , Cho La Hoon , Kim Min Jun , Jeong In Seon , Lee Chung Geon , Kim Dae Hyun
Published: January 2020

This study considers the possibility of utilizing agri-byproducts as energy sources via pelletization and torrefaction. Pellets were placed in a capsule and torrefied in an electrical furnace. Subsequently, they were cooled for 30 min, and their mass loss was measured. To investigate the resulting changes in fuel characteristics, ultimate and proximate analyses were performed, and calorific values were measured. To estimate the water absorption of the pellets, hygroscopicity evaluations were conducted. Based on the experimental results, the energy yield, lower heating value, and exergy were calculated to determine the optimum conditions for torrefaction. The calculation was performed by utilizing the useful exergy and standards applied to biomass power plants. We determined that torrefaction for agro-pellets should be conducted under low-to-intermediate temperatures (210–250 °C) within a period of 50 min. Under these conditions, 7–55% mass reductions were observed, the higher heating value increased from 4110 to 6880 kcal kg−1, and the lower heating value changed from 3780 to 6520 kcal kg−1 owing to reduced hygroscopicity. So, Agro-byproducts can contribute to the practical application by improving the heating value through torrefaction as an alternative to wood pellets.
Homogeneous Flux Distribution in High-Flux Solar Furnaces
Authors: Pereira José Carlos Garcia , Rodríguez José , Fernandes Jorge Cruz , Rosa Luís Guerra
Published: January 2020

Comparisons between experimental data and ray-tracing simulation results are presented for the high-flux SF60 solar furnace available at the Plataforma Solar de Almeria, Spain, which has an estimated thermal power of 60 kW. Since an important issue in many applications of solar concentrated radiation is to obtain a radiation distribution that is as homogeneous as possible over the central working area, so-called radiation homogenisers were also used but the degree of success achieved is just satisfactory, as the results show. Finally, further modelling studies using ray-tracing simulations aiming to attain a homogenous distribution of flux by means of double reflexion using two paraboloid surfaces are presented.
Load-Frequency Control of Multi-Area Power System Based on the Improved Weighted Fruit Fly Optimization Algorithm
Authors: Wang Nian , Zhang Jing , He Yu , Liu Min , Zhang Ying , Chen Chaokuan , Gu Yerui , Ren Yongheng
Published: January 2020

With the development and application of large-scale renewable energy sources, the electric power grid is becoming huge and complicated; one of the most concerning problems is how to ensure coordination between a large number of varied controllers. Differential games theory is used to solve the problem of collaborative control. However, it is difficult to solve the differential game problem with constraints by using conventional algorithm. Furthermore, simulation models established by existing research are almost linear, which is not conducive to practical engineering application. To solve the above problem, we propose a co-evolutionary algorithm based on the improved weighted fruit fly optimization algorithm (IWFOA) to solve a multi-area frequency collaborative control model with non-linear constraints. Simulation results show that the control strategy can achieve system control targets, and fully utilize the various characteristics of each generator to balance the interests of different areas. Compared with a co-evolutionary genetic algorithm and a collaborative multi-objective particle swarm optimization algorithm, the co-evolutionary algorithm based on the IWFOA has a better suppression effect on the frequency deviation and tie-line power deviation caused by the disturbance and has a shorter adjustment time.
Systems Analysis of SO2-CO2 Co-Capture from a Post-Combustion Coal-Fired Power Plant in Deep Eutectic Solvents
Authors: McGaughy Kyle , Reza M. Toufiq
Published: January 2020

In this study, CO2 and SO2 captures from post-combustion flue gas from a pulverized coal-fired power plant were evaluated using deep eutectic solvents (DES) to replace existing mono-ethanol amine (MEA) and CanSolv technologies. The system design of the DES-based CO2 and SO2 capture was based on the National Energy Technology Laboratory’s (NETL) 550 MWe pulverized coal-fired power plant model using Illinois #06 coal. Two of the most studied DES (choline chloride and urea at a 1:2 molar ratio and methyltriphenylphosphonium bromide (METPB) and ethylene glycol at a 1:3 molar ratio) for CO2 and SO2 capture were evaluated for this system analysis. Physical properties of DES were evaluated using both density functional theory (DFT)-based modeling as well as with documented properties from the literature. A technoeconomic assessment (TEA) was completed to assess DES ability to capture CO2 and SO2. Both solvents were able to fully dissolve and capture all SO2 present in the flue gas. It was also found from the system analyses that choline chloride and urea outperformed METPB and ethylene glycol (had a lower final cost) when assessed at 10–30% CO2 capture at high operating pressures (greater than 10 bar). At high system sizes (flow rate of greater than 50,000 kmoles DES per hour), choline chloride:urea was more cost effective than METPB:ethylene glycol. This study also establishes a modeling framework to evaluate future DES for physical absorption systems by both thermophysical and economic objectives. This framework can be used to greatly expedite DES candidate screening in future studies.
Mathematical Model of Carbon Dioxide Injection into a Porous Reservoir Saturated with Methane and Its Gas Hydrate
Authors: Khasanov Marat K. , Rafikova Guzal R. , Musakaev Nail G.
Published: January 2020

In this paper, the process of methane replacement in gas hydrate with carbon dioxide during CO2 injection into a porous medium is studied. A model that takes into account both the heat and mass transfer in a porous medium and the diffusion kinetics of the replacement process is constructed. The influences of the diffusion coefficient, the permeability and extent of a reservoir on the time of full gas replacement in the hydrate are analyzed. It was established that at high values of the diffusion coefficient in hydrate, low values of the reservoir permeability, and with the growth of the reservoir length, the process of the CH4-CO2 replacement in CH4 hydrate will take place in the frontal regime and be limited, generally, by the filtration mass transfer. Otherwise, the replacement will limited by the diffusion of gas in the hydrate.
A Two-Stage Industrial Load Forecasting Scheme for Day-Ahead Combined Cooling, Heating and Power Scheduling
Authors: Park Sungwoo , Moon Jihoon , Jung Seungwon , Rho Seungmin , Baik Sung Wook , Hwang Eenjun
Published: January 2020

Smart grid systems, which have gained much attention due to its ability to reduce operation and management costs of power systems, consist of diverse components including energy storage, renewable energy, and combined cooling, heating and power (CCHP) systems. The CCHP has been investigated to reduce energy costs by using the thermal energy generated during the power generation process. For efficient utilization of CCHP and numerous power generation systems, accurate short-term load forecasting (STLF) is necessary. So far, even though many single algorithm-based STLF models have been proposed, they showed limited success in terms of applicability and coverage. This problem can be alleviated by combining such single algorithm-based models in ways that take advantage of their strengths. In this paper, we propose a novel two-stage STLF scheme; extreme gradient boosting and random forest models are executed in the first stage, and deep neural networks are executed in the second stage to combine them. To show the effectiveness of our proposed scheme, we compare our model with other popular single algorithm-based forecasting models and then show how much electric charges can be saved by operating CCHP based on the schedules made by the economic analysis on the predicted electric loads.
Configuration Optimization Model for Data-Center-Park-Integrated Energy Systems under Economic, Reliability, and Environmental Considerations
Authors: Liu Zhiyuan , Yu Hang , Liu Rui , Wang Meng , Li Chaoen
Published: January 2020

The analysis of energy configuration in the planning of data-center-park-integrated energy systems (DCP-IESs) has become an enormous challenge, owing to multi-energy complementarity, energy cascade use, and energy security. In this study, a configuration model of DCP-IESs was established to obtain the economic and low-carbon energy uses of the data centers, based on mixed integer linear programming. In the model, carbon emissions were converted to economic indicators through carbon pricing. Then, the configuration model was modified according to the security of the proposed device switching logic, and the Markov-based reliability estimation method was used to ensure the redundant design of the configuration. Using the new energy configuration method, the DCP-IES configuration scheme could be obtained under economical, low-carbon, and high reliability conditions. A data center park in Shanghai was selected as a case study, and the results are as follows: it will only take 2.88 years for the economics of DCP-IES to reach those of traditional data center energy systems. Additionally, the use of configuration model in DCP-IES would result in a reduction in annual carbon emissions of 39,323 tons, with a power usage effectiveness of 1.388, whereas an increase in reliability results in an increasingly faster increase in the initial investment cost.
Real-Time Minimization Power Losses by Driven Primary Regulation in Islanded Microgrids
Authors: Tran Quynh T.T , Riva Sanseverino Eleonora , Zizzo Gaetano , Di Silvestre Maria Luisa , Nguyen Tung Lam , Tran Quoc-Tuan
Published: January 2020

Islanded microgrids are small networks that work independently from the main grid. The frequency and voltage in islanded microgrids are affected directly by the output power of distributed generators and power demand variations. In this work, a real-time driven primary regulation, which relies on optimized P-f droop coefficients, is proposed. In all operating conditions, it minimizes the power losses for islanded microgrids. The proposed configuration will allow the optimization modules to interact with each other and adjust parameters producing a suitable power sharing among generators. The methodology is tested based on a hardware-in-the-loop experimental set-up where distributed generators are connected to a group of loads. A parametric analysis is implemented for verification of the effectiveness of the proposed configuration as well as the improvement of the system reliability.
Spatial Characteristic of Coal Production-Based Carbon Emissions in Chinese Mining Cities
Authors: Lin Gang , Jiang Dong , Dong Donglin , Fu Jingying , Li Xiang
Published: January 2020

The objective of this paper is to investigate CO2 emissions in the production of coal sources at the prefecture level and to analyze their spatial distribution and regional differences based on the spatial autocorrelation and standard deviational ellipse analysis. The results indicate that Chinese coal production from 2018 will most likely generate 485.23 million tons of CO2 emissions, and there still exists an obvious gap between the five coal development districts in terms of their CO2 emissions. A significant clustering pattern and positive spatial autocorrelation are revealed in the coal production-based carbon emissions in China. In addition, the spatial pattern of coal production-based CO2 emissions has an obvious central tendency and directional trend, and the ellipse direction is quite consistent with the Aihui–Tengchong Line. Our findings suggest that energy policy-makers should be concerned about the carbon emission effect when implementing regional coal development plans and actively guide the formation of a low-carbon spatial strategic pattern of coal production with a directional distribution of CO2 emissions perpendicular to the Aihui–Tengchong Line.
Improved Position Control for an EGR Valve System with Low Control Frequency
Authors: Kim Hyeong-Jin , Son Yung-Deug , Kim Jang-Mok
Published: January 2020

An exhaust gas recirculation (EGR) valve position control system requires fast response without overshoot, but the low control frequency limits control bandwidth and results in poor position response. A novel EGR valve position control scheme is proposed to improve the position response at low control frequency. This is based on the feedforward controller, but the feedforward control loop is implemented without the position pattern generator or derivative. The proposed method estimates the acceleration command through the relationship between the position controller output, the speed command and the speed limiter, and compensates the cascaded proportional-proportional integral (P-PI) controller. In this method, many operations are not required and noise due to derivative is not generated. This method can improve the position response without much computation and derivative noise at the low control frequency. Experimental results are presented to verify the feasibility of the proposed position control algorithm.
Silver Decorated Reduced Graphene Oxide as Electrocatalyst for Zinc–Air Batteries
Authors: Poolnapol Laksanaporn , Kao-ian Wathanyu , Somwangthanaroj Anongnat , Mahlendorf Falko , Nguyen Mai Thanh , Yonezawa Tetsu , Kheawhom Soorathep
Published: January 2020

Due to their low cost and very high energy density, zinc–air batteries (ZABs) exhibit high potential for various energy applications. The electrochemical performance of the air-cathode has a decisive impact on the discharge performance of ZABs because the sluggish oxygen reduction reaction (ORR) kinetics increase the overpotential of the air-cathode and hence the performance of ZABs. In this work, reduced graphene oxide decorated with silver nanoparticles (AgNP/rGO) is synthesized using simultaneous reduction of graphene oxide and silver ions. Different amounts of silver loading are examined for the synthesis of AgNP/rGO. The synthesized AgNP/rGO samples are analyzed using a rotating disk electrode in order to investigate ORR activity. Then, the synthesized AgNP/rGO electrocatalyst is applied on a tubular designed zinc–air battery in order to study the performance of the zinc–air battery. Results demonstrate that AgNP/rGO is an efficient and cost-effective ORR electrocatalyst for its practical application in ZABs.
Influence of Critical Wall Roughness on the Performance of Double-Channel Sewage Pump
Authors: He Xiaoke , Zhang Yingchong , Wang Chuan , Zhang Congcong , Cheng Li , Chen Kun , Hu Bo
Published: January 2020

The numerical method on a double-channel sewage pump was studied, while the corresponding experimental result was also provided. On this basis, the influence of wall roughness on the pump performance was deeply studied. The results showed that there was a critical value of wall roughness. When the wall roughness was less than the critical value, it had a great influence on the pump performance, including the head, efficiency, and shaft power. As the wall roughness increased, the head and efficiency were continuously reduced, while the shaft power was continuously increased. Otherwise, the opposite was true. The effect of wall roughness on the head and hydraulic loss power was much smaller than that on the efficiency and disk friction loss power, respectively. With the increase of wall roughness, mechanical efficiency and hydraulic efficiency reduced constantly, leading to the decrement of the total efficiency. With the increase of flow rate, the effect of wall roughness on the head and efficiency gradually increased, while the influence on the leakage continuously reduced. The influence of the flow-through component roughness on the pump performance was interactive.
Development of Experimental Apparatus for Fire Resistance Test of Rechargeable Energy Storage System in xEV
Authors: Jung Hyuk , Moon Bohyun , Lee Gwang Goo
Published: January 2020

To secure the safety of xEV (all types of electrical vehicles), the United Nations released Global Technical Regulation No. 20, “Global Technical Regulations on the EVS (Electric Vehicle Safety)” in March 2018. The fire resistance test of the rechargeable energy storage system (REESS) describes an experimental procedure to evaluate the safety performance—specifically, whether passengers would have sufficient time to escape from the xEV before the explosion of the battery in a fire. There are two options for component-based REESS fire resistance tests: a gasoline pool fire and a liquefied petroleum gas (LPG) burner. This study describes the process for optimizing the specifications of the fire resistance test apparatus for xEV batteries using an LPG burner, which was first proposed by the Republic of Korea. Based on the results of the measurement and a computational fluid dynamics analysis of the prototype test apparatus, new equipment designs were proposed by determining the nozzle spacing and number, fuel flow rate, and experimental conditions. To cover a wide range of xEV battery sizes, a final test apparatus consisting of 625 burners was selected. For three different battery sizes, it was possible to satisfy the temperature requirements, ranging from 800 to 1000 °C, of the GTR fire resistance test. The final apparatus design developed in the present study has been included in GTR No. 20 for EVS since March 2018.
Forks in the Road to E-Mobility: An Evaluation of Instrument Interaction in National Policy Mixes in Northwest Europe
Authors: Dijk Marc , Iversen Eric , Klitkou Antje , Kemp René , Bolwig Simon , Borup Mads , Møllgaard Peter
Published: January 2020

This paper evaluates how policy shaped the emergence of electric mobility in three countries, Norway, the Netherlands and Denmark, between 2010 and 2015. Whereas previous studies have looked at the effects of separate policy instruments, this paper gives insights in the interaction effects of instruments on the diffusion of battery electric cars between five policy areas. Based on analysis of synergetic, contradictory and pre-conditional effects, we find that an effective policy mix includes: fiscal incentives that mirror the actual carbon footprint of the respective vehicles; non-fiscal demand-side incentives; centrally financed and/or coordinated charging infrastructure; clarity regarding the choice of technology that will be supported. Moreover, development of a domestic, e-mobility-related industry and a high share of renewable energy strengthens the legitimization of e-mobility support. The findings help designing policy mixes in the transition to electric mobility.
An Energy Optimal Dispatching Model of an Integrated Energy System Based on Uncertain Bilevel Programming
Authors: Song Xueying , Lin Hongyu , De Gejirifu , Li Hanfang , Fu Xiaoxu , Tan Zhongfu
Published: January 2020

An integrated energy system (IES) involving a large number of decision-makers causes problems of bad coordination between energy sub-networks and the IES and it is not able to fully consider the multi-energy complementarity among multiple decision-makers. In this context, firstly, this paper constructs an energy optimal dispatching model of an IES based on uncertain bilevel programming. The upper model takes the transformation matrix of energy hubs as the upper decision-maker, taking the minimum operation cost of the IES in the form of confidence as the objective function; the lower model takes each optimal operation plan of the electric power sub-network, the thermal energy sub-network, and the gas energy sub-network as the lower decision-makers, aiming at the operation economy of each sub-network and considering their operation as necessary constraints. Secondly, a firefly algorithm with chaotic search and an improved light intensity coefficient is designed to improve the proposed model. An empirical analysis was conducted on a pilot area of an integrated energy system in Hebei Province. The results show the following: (1) The typical daily operating cost of the integrated energy system in winter is lower than that in summer; (2) under the same load level, the typical winter and summer running costs of the integrated energy system are lower than that of the traditional microgrid; (3) compared with the particle swarm optimization algorithm, the improved firefly algorithm proposed in the paper has obvious advantages both in terms of running cost and solution time; and (4) when the confidence of the objective function and the constraints increases, the operating cost of various schemes also increase. The above results validate the effectiveness of the energy optimal dispatching model of the IES and the economy of the system operation under the multiple decision-maker hierarchy.