bluuebunny/crossref_metadata_2025 huggingface dataset:
Avaliação da composição química e do potencial de inibição do óleo fúsel frente a diferentes microrganismos
Authors: Mascarenhas Santos Maria do Socorro , Castro Thiago Luis Aguayo de , Batistote Margareth , Cardoso Claudia Andrea Lima
Published: August 2020

O controle da contaminação no processo fermentativo é fundamental para garantir a produtividade. Para minimizar a carga de contaminantes são feitos o tratamento ácido e a adição de antibióticos.  Entretanto, no próprio processo de produção de etanol, são formados outros álcoois que resultam em uma mistura conhecida como óleo fúsel que pode ser empregado para minimizar a contaminação. Assim, este estudo visa analisar amostras de óleo fúsel, caracterizar e avaliar o potencial de inibição desta substãncia frente a diferentes microrganismos. Inicialmente, foi realizado um levantamento bibliográfico para identificar as biomassas e compreender as etapas de formação do óleo fúsel.  Concomitantemente, foram analisadas amostras de óleo fúsel com relação aos parâmetros físico-químicos e a composição química. O potencial de inibição do óleo fúsel foi avaliada com o teste do halo de inibição utilizando as leveduras Catanduva-1 (Cat-1) e FT-858 e as bactérias Salmonella tiffi (ATCC 14028), Escherichia coli (ATCC 25922), Stafilicoccus aureus (ATCC 25923) e Bacillus sp. A produção de óleo fúsel está diretamente relacionada com o metabolismo das leveduras. As amostras apresentaram diferenças nos parâmetros físico-químicos e ambas apresentaram alto teor de álcool isoamilico. As bactérias apresentaram sensibilidade ao óleo fúsel demonstrando que este subproduto pode ser usado como agente antisséptico e antibacteriano.
Mídia e promoção da saúde em tempos de COVID-19
Authors: Silva Eduardo de Sousa Martins e , Ono Ben Hur Vitor Silva , Souza José carlos , Menin Iris Bucker Froes
Published: August 2020

O acesso à informação é uma das formas mais importantes de se promover saúde. O entendimento das circunstâncias atuais ajuda a população a se posicionar e a enfrentar a pandemia de COVID-19. No entanto, a sobrecarga de notícias e dados, muitas vezes falsos, oferece riscos à saúde mental e ao bem-estar. Observa-se, fomentado por notícias tendenciosas as quais estimulam o pânico, um aumento global dos níveis de ansiedade, depressão, entre outros transtornos psíquicos. É necessário que os indivíduos sejam informados sobre a pandemia sem alarde. Desta forma, este artigo objetiva analisar como a mídia e as redes sociais relacionam-se com a promoção de saúde durante a pandemia de COVID-19 e as dificuldades geradas pela “infodemia”. Fez-se uma revisão bibliográfica integrativa usando-se artigos científicos dos últimos dez anos, das bases de dados PUBMED, com os descritores: Comunicação; Promoção; Pandemia; COVID-19; Saúde. Além dos livros “Comunicação e saúde” e “Health promotion practice”.
Ocorrência de formigas cortadeiras em campos de altitude no sul do Brasil
Authors: Giesel Alexandre , Boff Pedro , Boff Mari Inês Carissimi , Fernandes Patricia
Published: August 2020

Remanescentes do ecossistema Campos Altitude são encontrados na microrregião de "Campos de Lages", SC, sul do Brasil. O objetivo deste trabalho foi avaliar e identificar espécies de formigas cortadeiras que ocorrem em Campos de Altitude. O estudo foi realizado entre os meses de Agosto de 2012 e Dezembro de 2013, em 18 municípios da micro-região de "Campos de Lages", Santa Catarina, sul do Brasil. No total, 75 formigueiros de cortadeiras foram localizados, medidos e georreferenciados, apresentando 16 formigueiros pertencentes ao gênero Atta e  59 do gênero Acromyrmex. Amostras de formigas de diferentes castas foram recolhidas de cada formigueiro para identificação adequada. Uma espécie foi identificada no gênero Atta, A. sexdens piriventris e oito no gênero Acromyrmex, A. laticeps, A. heyeri, A. Iundii, A. crassispinus, A. ambiguus, A. aspersus, A. coronatus. As espécies Atta sexdens piriventris, Ac. laticeps e Ac. heyeri foram as mais frequentes. Espécies pertencentes ao gênero Acromyrmex foram localizadas em altitudes acima dos 1000 metros, e tamanho médio de formigueiros de 1,04 ± 0,93 m2. Formigueiros do gênero Atta foram localizados em altitudes de até 850 metros, e apresentaram um tamanho médio 132,75 ± 12,96 m2 de área total de superfície, considerando à área dos olheiros.
Impacto epidemiológico da Sífilis gestacional e congênita e sua relação com a mortalidade infantil no Estado do Piauí, Brasil
Authors: Oliveira Evaldo Hipólito de , Almeida Ana Tárcila Alves de , Marques Maria Crisnanda Almeida , Silva Eduarda Pereira da , Castro Isione Oliveira
Published: August 2020

Este trabalho objetivou identificar e avaliar o perfil epidemiológico de casos de sífilis materna, congênita e consequentes óbitos infantis decorrentes desta infecção, no Estado do Piauí, notificados no período entre 2010 e 2018. Realizou-se um estudo retrospectivo, a partir de dados secundários do Núcleo de Informação e Análise em Saúde (DATASUS), através do Sistema Nacional de Agravos de Notificação (SINAN) e no Sistema de Informação sobre Mortalidade (SIM) da Secretaria de Estado da Saúde do Piauí (SESAPI). Foram correlacionados vários indicadores importantes para a doença, sendo observado um número crescente de casos ao longo dos anos, sendo observado o aumento concomitante com a taxa de incidência de sífilis gestacional e congênita. A quantidade de óbito se mostrou elevada, o pré-natal apresentou um bom percentual ao longo dos anos embora as evidências constatam a baixa qualidade desta assistência nos aspectos: diagnóstico especialmente tardio durante a gestação e do tratamento em boa parte dos casos realizado de forma inadequada . Todos esses fatores culminam para aumento de sífilis adquirida, com a possibilidade de relação com o aumento da mortalidade infantil. Diante disso, percebe-se que mesmo com os avanços na prevenção da sífilis, essa doença ainda acomete muitas mulheres, causando tanto sequelas como o aumento da mortalidade infantil.
Regression kriging to improve basal area and growing stock volume estimation based on remotely sensed data, terrain indices and forest inventory of black pine forests
Authors: Bolat Ferhat , Bulut Sinan , Günlü Alkan , Ercanlı İlker , Şenyurt Muammer
Published: August 2020

Background: The use of satellite imagery to quantify forest metrics has become popular because of the high costs associated with the collection of data in the field.Methods: Multiple linear regression (MLR) and regression kriging (RK) techniques were used for the spatial interpolation of basal area (G) and growing stock volume (GSV) based on Landsat 8 and Sentinel-2. The performance of the models was tested using the repeated k-fold cross-validation method.Results: The prediction accuracy of G and GSV was strongly related to forest vegetation structure and spatial dependency. The nugget value of semivariograms suggested a moderately spatial dependence for both variables (nugget/sill ratio approx. 70%). Landsat 8 and Sentinel-2 based RK explained approximately 52% of the total variance in G and GSV. Root-mean-square errors were 7.84 m2 ha-1 and 49.68 m3 ha-1 for G and GSV, respectively.Conclusions: The diversity of stand structure particularly at the poorer sites was considered the principal factor decreasing the prediction quality of G and GSV by RK.
PENGEMBANGAN PENGEMBANGAN LEMBAR KERJA SISWA UNTUK MENINGKATKAN PEMAHAMAN GEOMETRI BERBASIS PEMBELAJARAN COOPERATIVE INTEGRATED READING AND COMPOSITION
Authors: Andang Andang , Silviana Dewi , Merdekawati Arnasari
Published: August 2020

Tujuan penelitian ini adalah untuk menghasilkan perangkat pembelajaran berbentuk lembar kerja siswa dengan model pembelajaran Cooperative Integrated Reading and Composition guna meningkatkan pemahaman geometri dan mengetahui respon siswa terhadap lembar kerja siswa yang telah dikembangkan. Jenis penelitian ini merupakan penelitian pengembangan (Research and Development) dengan model Ploomp. Subjek uji coba lapangan meliputi 32 siswa kelas VIII-7 di SMP Negeri 1 Kota Bima. Instrumen penelitian yang digunakan terdiri dari lembar validasi, lembar observasi keterlaksanaan pembelajaran, lembar observasi aktivitas siswa, angket respons siswa, angket penilaian guru, dan tes pemahaman geometri. Hasil penilaian menunjukan bahwa perangkat pembelajaran dengan model Cooperative Integrated Reading and Composition (CIRC) pada materi geometri (lingkaran) di kelas VIII yang berbentuk LKS adalah valid dengan kategori sangat baik setelah dilakukan beberapa kali revisi, dinyatakan memenuhi kriteria kepraktisan setelah melalui tahap uji coba lapangan dengan rata-rata persentase aktivitas guru pada proses pembelajaran sebesar 4,38 atau berkategori baik dan respon siswa positif yang ditunjukan dengan minat dan ketertarikannya yang tinggi dalam mengikuti pembelajaran, dinyatakan efektif untuk digunakan dilihat dari tingkat pemahaman konsep siswa dengan ketuntasan klasikal 87,09%.
On the Triple Lauricella–Horn–Karlsson q-Hypergeometric Functions
Authors: Ernst Thomas
Published: August 2020

The Horn–Karlsson approach to find convergence regions is applied to find convergence regions for triple q-hypergeometric functions. It turns out that the convergence regions are significantly increased in the q-case; just as for q-Appell and q-Lauricella functions, additions are replaced by Ward q-additions. Mostly referring to Krishna Srivastava 1956, we give q-integral representations for these functions.
Fault Diagnosis for Rotating Machinery Using Multiscale Permutation Entropy and Convolutional Neural Networks
Authors: Li Hongmei , Huang Jinying , Yang Xiwang , Luo Jia , Zhang Lidong , Pang Yu
Published: August 2020

In view of the limitations of existing rotating machine fault diagnosis methods in single-scale signal analysis, a fault diagnosis method based on multi-scale permutation entropy (MPE) and multi-channel fusion convolutional neural networks (MCFCNN) is proposed. First, MPE quantitatively analyzes the vibration signals of rotating machine at different scales, and obtains permutation entropy (PE) to construct feature vector sets. Then, considering the structure and spatial information between different sensor measurement points, MCFCNN constructs multiple channels in the input layer according to the number of sensors, and each channel corresponds to the MPE feature sets of different monitored points. MCFCNN uses convolutional kernels to learn the features of each channel in an unsupervised way, and fuses the features of each channel into a new feature map. At last, multi-layer perceptron is applied to fuse multi-channel features and identify faults. Through the health monitoring experiment of planetary gearbox and rolling bearing, and compared with single channel convolutional neural networks (CNN) and existing CNN based fusion methods, the proposed method based on MPE and MCFCNN model can diagnose faults with high accuracy, stability, and speed.
On the Complementarity of the Harmonic Oscillator Model and the Classical Wigner–Kirkwood Corrected Partition Functions of Diatomic Molecules
Authors: Buchowiecki Marcin
Published: August 2020

The vibrational and rovibrational partition functions of diatomic molecules are considered in the regime of intermediate temperatures. The low temperatures are those at which the harmonic oscillator approximation is appropriate, and the high temperatures are those at which classical partition function (with Wigner–Kirkwood correction) is applicable. The complementarity of the harmonic oscillator and classical integration over the phase space approaches is investigated for the CO and H2+ molecules showing that those two approaches are complementary in the sense that they smoothly overlap.
Thermalization in a Quantum Harmonic Oscillator with Random Disorder
Authors: Hsueh Ya-Wei , Hsueh Che-Hsiu , Wu Wen-Chin
Published: August 2020

We propose a possible scheme to study the thermalization in a quantum harmonic oscillator with random disorder. Our numerical simulation shows that through the effect of random disorder, the system can undergo a transition from an initial nonequilibrium state to a equilibrium state. Unlike the classical damped harmonic oscillator where total energy is dissipated, total energy of the disordered quantum harmonic oscillator is conserved. In particular, at equilibrium the initial mechanical energy is transformed to the thermodynamic energy in which kinetic and potential energies are evenly distributed. Shannon entropy in different bases are shown to yield consistent results during the thermalization.
Computer Assisted Wargame for Military Capability-Based Planning
Authors: Hodický Jan , Procházka Dalibor , Baxa Fabian , Melichar Josef , Krejčík Milan , Křížek Petr , Stodola Petr , Drozd Jan
Published: August 2020

Capability-based planning as an approach to defense planning is an almost infinitely complex engineered system with countless nodes and layers of interdependency, influenced by state and non-state diplomatic activities, information, military and economic actions creating secondary and third order effects. The main output of capability-based planning is the set of capability requirements needed to achieve the expected end-state. One revitalized qualitative technique that allows us to gain insights into unstructured and fuzzy problems in the military is wargaming—in its simplest form this involves manual wargaming. At the same time, there has been a push to bring computer assistance to such wargaming, especially to support umpire adjudication and move more generally towards full automation of human elements in wargames. However, computer assistance in wargaming should not be pushed, regardless of cost, towards quantitative techniques. The objective complexity of a problem often does not allow us to replicate the operational environment with the required fidelity to get credible experimental results. This paper discusses a discovery experiment aiming to verify the concept of applying a qualitative expert system within computer assisted wargaming for developing capability requirements in order to reduce umpire bias and risk associated with their decisions. The innovation here lies in applying system dynamics modelling and simulation paradigms when designing the theoretical model of capability development, which forms the core of the expert system. This new approach enables qualitative comparisons between different sets of proposed capability requirements. Moreover, the expert system allows us to reveal the effects of budget cuts on proposed capability requirement solutions, which the umpire was previously unable to articulate when comparing individual solutions by relying solely on his own knowledge. Players in the wargame validated the proposed concept and suggested how the study might be developed going forward: namely, by enabling users to define their own capabilities and not being limited by a predefined set of capabilities.
A Fuzzy-Based Product Life Cycle Prediction for Sustainable Development in the Electric Vehicle Industry
Authors: Tsang Yung Po , Wong Wai Chi , Huang G. Q. , Wu Chun Ho , Kuo Y. H. , Choy King Lun
Published: August 2020

The development of electric vehicles (EVs) has drawn considerable attention to the establishment of sustainable transport systems to enable improvements in energy optimization and air quality. EVs are now widely used by the public as one of the sustainable transportation measures. Nevertheless, battery charging for EVs create several challenges, for example, lack of charging facilities in urban areas and expensive battery maintenance. Among various components in EVs, the battery pack is one of the core consumables, which requires regular inspection and repair in terms of battery life cycle and stability. The charging efficiency is limited to the power provided by the facilities, and therefore the current business model for EVs is not sustainable. To further improve its sustainability, plug-in electric vehicle battery pack standardization (PEVBPS) is suggested to provide a uniform, standardized and mobile EV battery that is managed by centralized service providers for repair and maintenance tasks. In this paper, a fuzzy-based battery life-cycle prediction framework (FBLPF) is proposed to effectively manage the PEVBPS in the market, which integrates the multi-responses Taguchi method (MRTM) and the adaptive neuro-fuzzy inference system (ANFIS) as a whole for the decision-making process. MRTM is formulated based on selection of the most relevant and critical input variables from domain experts and professionals, while ANFIS takes part in time-series forecasting of the customized product life-cycle for demand and electricity consumption. With the aid of the FPLCPF, the revolution of the EV industry can be revolutionarily boosted towards total sustainable development, resulting in pro-active energy policies in the PEVBPS eco-system.
A Distributed Optimization Method for Energy Saving of Parallel-Connected Pumps in HVAC Systems
Authors: Wang Xuetao , Zhao Qianchuan , Wang Yifan
Published: August 2020

Motivated by the importance and challenges of the energy saving problem of parallel-connected pumps in heating, ventilation, and air-conditioning (HVAC) systems, we propose a distributed optimal control algorithm for on-off status and flow rate set points of parallel-connected pumps in HVAC systems. The proposed algorithm consists of two parts: First, in order to process the network information, we apply the breadth first search algorithm to construct a tree for exchanging messages. Second, all nodes coordinate with each other and randomly sample the speed ratios. To our best knowledge, the algorithm proposed in this paper is the first effort to address the challenges of existing studies at the same time. The algorithm solves the pump optimization problem in a distributed manner, achieves the minimum pump energy consumption and has the convergence guarantee. Even if some of the pumps break down, the whole system can still be working and have great flexibility. Simulation experiments on six parallel-connected pumps are provided for different working cases to demonstrate the effectiveness of the proposed algorithm and compare with the other four methods. The results show that our algorithm strictly satisfies the demand constraints and presents good energy saving potential, the convergence guarantee, and flexibility. The maximum energy saving can be up to 29.92%.
Deep Reinforcement Learning-Based Voltage Control to Deal with Model Uncertainties in Distribution Networks
Authors: Toubeau Jean-François , Bakhshideh Zad Bashir , Hupez Martin , De Grève Zacharie , Vallée François
Published: August 2020

This paper addresses the voltage control problem in medium-voltage distribution networks. The objective is to cost-efficiently maintain the voltage profile within a safe range, in presence of uncertainties in both the future working conditions, as well as the physical parameters of the system. Indeed, the voltage profile depends not only on the fluctuating renewable-based power generation and load demand, but also on the physical parameters of the system components. In reality, the characteristics of loads, lines and transformers are subject to complex and dynamic dependencies, which are difficult to model. In such a context, the quality of the control strategy depends on the accuracy of the power flow representation, which requires to capture the non-linear behavior of the power network. Relying on the detailed analytical models (which are still subject to uncertainties) introduces a high computational power that does not comply with the real-time constraint of the voltage control task. To address this issue, while avoiding arbitrary modeling approximations, we leverage a deep reinforcement learning model to ensure an autonomous grid operational control. Outcomes show that the proposed model-free approach offers a promising alternative to find a compromise between calculation time, conservativeness and economic performance.
Optimal Sizing and Scheduling of Hybrid Energy Systems: The Cases of Morona Santiago and the Galapagos Islands
Authors: Benalcazar Pablo , Suski Adam , Kamiński Jacek
Published: August 2020

Hybrid energy systems (HESs) generate electricity from multiple energy sources that complement each other. Recently, due to the reduction in costs of photovoltaic (PV) modules and wind turbines, these types of systems have become economically competitive. In this study, a mathematical programming model is applied to evaluate the techno-economic feasibility of autonomous units located in two isolated areas of Ecuador: first, the province of Galapagos (subtropical island) and second, the province of Morona Santiago (Amazonian tropical forest). The two case studies suggest that HESs are potential solutions to reduce the dependence of rural villages on fossil fuels and viable mechanisms to bring electrical power to isolated communities in Ecuador. Our results reveal that not only from the economic but also from the environmental point of view, for the case of the Galapagos province, a hybrid energy system with a PV–wind–battery configuration and a levelized cost of energy (LCOE) equal to 0.36 $/kWh is the optimal energy supply system. For the case of Morona Santiago, a hybrid energy system with a PV–diesel–battery configuration and an LCOE equal to 0.37 $/kWh is the most suitable configuration to meet the load of a typical isolated community in Ecuador. The proposed optimization model can be used as a decision-support tool for evaluating the viability of autonomous HES projects at any other location.
Ferrocene Derivatives Functionalized with Donor/Acceptor (Hetero)Aromatic Substituents: Tuning of Redox Properties
Authors: Manfredi Norberto , Decavoli Cristina , Boldrini Chiara L. , Coluccini Carmine , Abbotto Alessandro
Published: August 2020

A series of functionalized ferrocene derivatives carrying electron-donor and electron-withdrawing (hetero)aromatic substituents has been designed as potential alternative electrolyte redox couples for dye-sensitized solar cells (DSSC). The compounds have been synthesized and fully characterized in their optical and electrochemical properties. A general synthetic approach that implies the use of a microwave assisted Suzuki coupling has been developed to access a significative number of compounds. The presence of different electron-rich and electron-poor substituents provided fine tuning of optical properties and energy levels. HOMO and LUMO energy values showed that the substitution of one or two cyclopentadienyl rings of ferrocene can be successfully exploited to increase the maximum attainable voltage from a standard DSSC device using TiO2 as a semiconductor, opening the way to highly efficient, non-toxic, and cheap redox shuttles to be employed in solar energy technologies.
An Energy Efficient Message Dissemination Scheme in Platoon-Based Driving Systems
Authors: Kim Taeyoon , Song Taewon , Pack Sangheon
Published: August 2020

With the development of the convergence of IT and automotive technology, platoon-based driving systems are getting more attention and how to disseminate messages in the platoon is an important issue. In this paper, to enhance the energy efficiency and traffic throughput (e.g., average velocity) while meeting transmission deadlines, we propose an energy efficient message dissemination scheme (EMDS) in platoon-based driving systems, which also provides proper power control and relay selection. To find out the optimal policy to balance the probability of successful message dissemination and transmission power cost in EMDS, we formulate a Markov decision process (MDP) problem that considers the velocity of the vehicles in the platoon. To evaluate the performance of EMDS, we analyze the outage probability, the average velocity, and the expected power consumption using the discrete-time Markov chain (DTMC) model. Evaluation results demonstrate EMDS with the optimal policy improves the average velocity and the energy efficiency of message dissemination compared with the conventional message dissemination schemes, while reducing the message dissemination failure rate.
Study of a Hybrid Solar Absorption-Cooling and Flash-Desalination System
Authors: Velázquez-Limón Nicolás , López-Zavala Ricardo , Hernández-Callejo Luis , Aguilar-Jiménez Jesús A. , Ojeda-Benítez Sara , Ríos-Arriola Juan
Published: August 2020

In this work, the analysis of a hybrid LiBr/H2O absorption-cooling and flash-desalination system, using solar thermal energy as heat source, is presented. An absorption open-cycle with three pressure levels is used in combination with a single-stage flash-desalination process to use the coolant as product water, resulting in an increase in cooling and desalination efficiency. For the application, a 20-room coastal hotel complex in San Felipe, Baja California, Mexico, is taken as a case study and the sizing of the solar collection and storage system is carried out for the operation of the proposed hybrid system, during the summer operative period. The operational dynamics during the week with the highest ambient temperatures are presented. The dimensioning of the solar collector’s area and the energy storage resulted in a collection area of 620 m2 with 30 m3, respectively, reaching a solar fraction of 69%. The absorption-cooling subprocess showed an increase of 13.88% in the average coefficient of performance (COP) compared to conventional LiBr/H2O absorption systems. Also, considering that the system provides cooling and desalination simultaneously, the average COPG is 1.64, which is 2.27 times higher than the COP of conventional LiBr/H2O single-effect absorption units. During the critical week, the system presented a desalinated water production of 16.94 m3 with an average performance ratio (PR) of 0.83, while the average daily water production was 2406 kg/day; enough to satisfy the daily water requirements of four people in a coastal hotel in Mexico or to cover the basic services of 24 people according to the World Health Organization.
Using Load Forecasting to Control Domestic Battery Energy Storage Systems
Authors: Koskela Juha , Mutanen Antti , Järventausta Pertti
Published: August 2020

The profitability of domestic battery energy storage systems has been poor and this is the main barrier to their general use. It is possible to increase profitability by using multiple control targets. Market price-based electricity contracts and power-based distribution tariffs alongside storage of surplus photovoltaic energy make it possible to have multiple control targets in domestic use. The battery control system needs accurate load forecasting so that its capacity can be utilized in an optimally economical way. This study shows how the accuracy of short-term load forecasting affects cost savings by using batteries. The study was conducted by simulating actual customers’ load profiles with batteries utilized for different control targets. The results of the study show that knowledge of customers’ load profiles (i.e., when high and low peaks happen) is more important that actual forecast accuracy, as measured by error criteria. In many cases, the load forecast based on customers’ historical load data and the outdoor temperature is sufficient to be used in the control system, but in some cases a more accurate forecast can give better cost savings.
A Review of Uncertain Decision-Making Methods in Energy Management Using Text Mining and Data Analytics
Authors: Tavana Madjid , Shaabani Akram , Javier Santos-Arteaga Francisco , Raeesi Vanani Iman
Published: August 2020

The managerial and environmental studies conducted in the energy research area reflect its substantial importance, particularly when optimizing and modifying consumption patterns, transitioning to renewable sources away from fossil ones, and designing plans and systems. The aim of this study is to provide a systematic review of the literature allowing us to identify which research subjects have been prioritized in the fields of energy and sustainability in recent years, determine the potential reasons explaining these trends, and categorize the techniques applied to analyze the uncertainty faced by decision-makers. We review articles published in highly ranked journals through the period 2003–2020 and apply text analytics to cluster their main characteristics; that is, we rely on pre-processing and text mining techniques. We analyze the title, abstract, keywords, and research methodology of the articles through clustering and topic modeling and illustrate what methods and fields constitute the main focus of researchers. We demonstrate the substantial importance of fuzzy-related methods and decision-making techniques such as the Analytical Hierarchy Process and Technique for Order Preferences by Similarity to Ideal Solutions (TOPSIS). We also show that subjects such as renewable energy, energy planning, sustainable energy, energy policy, and wind energy have gained relevance among researchers in recent years.
Modeling the Impact of Electric Vehicle Charging Systems on Electric Power Quality
Authors: Baraniak Joanna , Starzyński Jacek
Published: August 2020

Recently, there has been dynamic development of electromobility. This trend is predicted to grow exponentially, which will contribute to the creation of an extensive infrastructure of electric car charging points. For distribution network operators, this implies that in addition to the increase in demand for power and electricity, the number of converter systems connected to their networks will also increase. It is therefore necessary to determine the potential impact of electric vehicle charging systems on electricity quality. To this end, the authors of the present study developed simulation models based on measurements of the actual charger and the data provided by the manufacturers of the equipment and using simulation models widely described in the literature. On the basis of the study results, the impact of electric car chargers on electric power quality was assessed, and attention was given to the opportunities offered by the development of charging systems with vehicle-to-grid (V2G) functionality. Changes in technical standards aimed at selecting power supply cables by considering their heating under the influence of higher current harmonics generated by converter systems were proposed.
Energy Intensity and Long- and Short-Term Efficiency in US Manufacturing Industry
Authors: Badunenko Oleg , Kumbhakar Subal C.
Published: August 2020

We analyze energy use efficiency of manufacturing industries in US manufacturing over five decades from 1960 to 2011. We apply a 4-component stochastic frontier model, which allows disentangling efficiency into a short- and long-term efficiency as well as accounting for industry heterogeneity. The data come from NBER-CES Manufacturing Industry Database. We find that relative to decade-specific frontiers, the overall efficiency of manufacturing industries, which is a product of transient and persistent efficiencies has deteriorated greatly in the 1970s and rebounded only in the 2000s. The industries are very efficient in the short-term and this has not changed over five decades. The high level of overall inefficiency is almost completely due to the structural inefficiency which can be explained by what is referred to as the “energy paradox”. Finally, higher energy-intensive industries perform worse in terms of energy use efficiency than their low energy-intensity counterparts.
Design and Development of Non-Isolated Modified SEPIC DC-DC Converter Topology for High-Step-Up Applications: Investigation and Hardware Implementation
Authors: Premkumar Manoharan , Subramaniam Umashankar , Haes Alhelou Hassan , Siano Pierluigi
Published: August 2020

A new non-isolated modified SEPIC front-end dc-dc converter for the low power system is proposed in this paper, and this converter is the next level of the traditional SEPIC converter with additional devices, such as two diodes and splitting of the output capacitor into two equal parts. The circuit topology proposed in this paper is formulated by combining the boost structure with the traditional SEPIC converter. Therefore, the proposed converter has the benefit of the SEPIC converter, such as continuous input current. The proposed circuit structure also improves the features, such as high voltage gain and high conversion efficiency. The converter comprises one MOSFET switch, one coupled inductor, three diodes, and two capacitors, including the output capacitor. The converter effectively recovers the leakage energy of the coupled inductor through the passive clamp circuit. The operation of the proposed converter is explained in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The required voltage gain of the converter can be acquired by adjusting the coupled inductor turn’s ratio along with the additional devices at less duty cycle of the switch. The simulation of the proposed converter under CCM is carried out, and an experimental prototype of 100 W, 25 V/200 V is made, and the experimental outcomes are presented to validate the theoretical discussions of the proposed converter. The operating performance of the proposed converter is compared with the converters discussed in the literature. The proposed converter can be extended by connecting voltage multiplier (VM) cell circuits to get the ultra-high voltage gain.
Tests of an Absorption Cooling Machine at the Gijón Solar Cooling Laboratory
Authors: Suárez López María-José , Prieto Jesús-Ignacio , Blanco Eduardo , García David
Published: August 2020

Final energy consumption in the residential sector is increasing, even in countries with favourable climate conditions and technological capacity to promote the use of renewable resources and energy efficiency. Air conditioning systems based on absorption cycles are common solutions in solar assisted installations. In this paper, the main characteristics of the Gijón Solar Cooling Laboratory (GSCL) are summarized, showing its ability to test cooling machines with a variety of heat sources and sinks, as well as different technologies and strategies. An absorption machine with internal energy storage in LiCl salts has been tested at the GSCL, measuring power and temperatures as a function of time during several charging and discharging cycles. During the charging cycles, the operation of the machine was analysed for various hot temperatures and power values. In the discharging cycles, special attention was paid to the refrigeration capacity produced for various chilled water temperatures. The results led to coefficient of performance COP values that are in line with those expected for this technology. Satisfactory operation of the system seems difficult at activation temperatures below 75 °C. For low levels of insolation, this limitation could lead to an increase in auxiliary energy consumption.
MMC-Based PV Single-Phase System with Distributed MPPT
Authors: Barcellona Simone , Barresi Marzio , Piegari Luigi
Published: August 2020

The presence and evolution of static power converters in electric grids are growing on a daily basis. Starting from the most used voltage source converter (VSC), passing through the use of multilevel converters, the most recent configuration is the so-called modular multilevel converter (MMC). Because of its intrinsic advantages, it is used not only in high-voltage systems but also in low- and medium-voltage ones to interface renewable energy sources such as photovoltaic (PV) panels. Several configurations and maximum power point tracker (MPPT) algorithms have been proposed and analyzed for MMC-PV-based systems. However, when using distributed MPPTs, partial shading conditions cause a problem. The PV panel can be directly connected to the MMC using its dc link or submodule. Based on this configuration, this paper proposes a novel control strategy that tracks both the ac grid current and ac circulating current for a single-phase low-voltage system to obtain the maximum power under any irradiance condition. The effectiveness of the proposed control strategy is demonstrated through time-domain simulation results.
Smart Grid Monitoring by Wireless Sensors Using Binary Logistic Regression
Authors: Manoharan Hariprasath , Teekaraman Yuvaraja , Kirpichnikova Irina , Kuppusamy Ramya , Nikolovski Srete , Baghaee Hamid Reza
Published: August 2020

This article focuses on addressing the data aggregation faults caused by the Phasor Measuring Unit (PMU) by installing Wireless Sensor Networks (WSN) in the grid. All data that is monitored by PMU should be sent to the base station for further action. But the data that is sent from PMU does not reach the main server properly in many situations. To avoid this situation, a sensor-based technology has been introduced in the proposed method for sensing the values that are monitored by PMU. Also, the basic parameters that are necessary for determining optimal solutions like energy consumption, distance and cost have been calculated for wireless sensors, whereas, for PMU optimal placements with cost analysis have been restrained. For analyzing and improving the accuracy of the proposed method, an effective Binary Logistic Regression (BLR) algorithm has been integrated with an objective function. The sensor will report all measured PMU values to an Online Monitoring System (OMS). To examine the effectiveness of the proposed method, the examined values are visualized in MATLAB and results prove that the proposed method using BLR is more effective than existing methods in terms of all parametric values and the much improved results have been obtained at a rate of 81.2%.
Thermogravimetric Kinetics of Selected Energy Crops Pyrolysis
Authors: Matusiak Magdalena , Ślęzak Radosław , Ledakowicz Stanisław
Published: August 2020

The main purpose of this paper was to compare the pyrolysis kinetics of three types of energy crops: Miscanthus giganteus, Sida hermaphrodita, and Sorghum Moench. Studies were conducted in thermobalance. Feedstock samples were heated up from ambient temperature to 600 °C under an inert argon atmosphere. Three heating rates of β = 5, 10, and 20 °C/min were applied. Reactions occurring in the given temperature ranges were grouped together into so-called lumps identified by the deconvolution of derivative thermogravimetry (DTG) curves that corresponded to biomass compositions (hemicellulose, cellulose, and lignin). For the estimation of the activation energy and pre-exponential factor, the Friedman and Ozawa–Flynn–Wall methods were used. The final kinetic parameters were determined by nonlinear regression assuming that thermal decomposition proceeded via three parallel independent reactions of the nth order. The activation energy of hemicellulose, cellulose and lignin was determined to be in the range of 92.9–97.7, 190.1–192.5, and 170–175.2 kJ/mol, respectively. The reaction order was in the range of 3.35–3.99 for hemicellulose, 1.38–1.93 for cellulose, and 3.97–3.99 for lignin. The obtained results allow us to estimate the pyrolytic potential of energy crops selected for this study, and can be used in designing efficient pyrolizers for these materials.
Insight into Foam Pore Effect on Phase Change Process in a Plane Channel under Forced Convection Using the Thermal Lattice Boltzmann Method
Authors: Mabrouk Riheb , Naji Hassane , Dhahri Hacen , Younsi Zohir
Published: August 2020

In this work, the two-dimensional laminar flow and the heat transfer in an open-ended rectangular porous channel (metal foam) including a phase change material (PCM; paraffin) under forced convection were numerically investigated. To gain further insight into the foam pore effect on charging/discharging processes, the Darcy–Brinkmann–Forchheimer (DBF) unsteady flow model and that with two temperature equations based on the local thermal non-equilibrium (LTNE) were solved at the representative elementary volume (REV) scale. The enthalpy-based thermal lattice Boltzmann method (TLBM) with triple distribution function (TDF) was employed at the REV scale to perform simulations for different porosities (0.7≤ε≤0.9) and pore per inch (PPI) density (10≤PPI≤60) at Reynolds numbers (Re) of 200 and 400. It turned out that increasing Re with high porosity and PPI (0.9 and 60) speeds up the melting process, while, at low PPI and porosity (10 and 0.7), the complete melting time increases. In addition, during the charging process, increasing the PPI with a small porosity (0.7) weakens the forced convection in the first two-thirds of the channel. However, the increase in PPI with large porosity and high Re number limits the forced convection while improving the heat transfer. To sum up, the study findings clearly evidence the foam pore effect on the phase change process under unsteady forced convection in a PCM-saturated porous channel under local thermal non-equilibrium (LTNE).
Comparative Study of Tubular Solar Stills with Phase Change Material and Nano-Enhanced Phase Change Material
Authors: Thalib M. Mohamed , Manokar Athikesavan Muthu , Essa Fadl A. , Vasimalai N. , Sathyamurthy Ravishankar , Garcia Marquez Fausto Pedro
Published: August 2020

This study is intended to investigate and analyze the operational performances of the Conventional Tubular Solar Still (CTSS), Tubular Solar Still with Phase Change Material (TSS-PCM) and Tubular Solar Still with Nano Phase Change Material (TSS-NPCM). Paraffin wax and graphene plusparaffin wax were used in the CTSS to obtain the modified solar still models. The experimental study was carried out in the three stills to observe the operational parameters at a water depth of 1 cm. The experiment revealed that TSS-NPCM showed the best performance and the highest yield in comparison to other stills. The distillate yield from the CTSS, TSS-PCM and TSS-NPCM was noted to be 4.3, 6.0 and 7.9 kg, respectively, the daily energy efficiency of the stills was observed to be 31%, 46% and 59%, respectively, and the daily exergy efficiency of the stills was recorded to be 1.67%, 2.20% and 3.75%, respectively. As the performance of the TSS-NPCM was enhanced, the cost of freshwater yield obtained was also low in contrast to the other two types of stills.
Sustainable Rehabilitation of Surface Coal Mining Areas: The Case of Greek Lignite Mines
Authors: Pavloudakis Francis , Roumpos Christos , Karlopoulos Evangelos , Koukouzas Nikolaos
Published: August 2020

Surface lignite mines of the Balkan Peninsula face growing pressure due to the CO2 emissions reduction initiatives, rapidly increasing renewable-power capacity, and cheap natural gas. In this frame, the development of a modern mine land rehabilitation strategy is considered as a prerequisite for mitigating the social and economic impacts for the local communities. In the case of western Macedonia lignite mines, these prospects are investigated based on a PEST (political, economic, social, technological) analysis of seven alternative land uses. Urban (industrial) development, green houses, and industrial heritage parks are considered as the most appropriate land uses for mitigating the socioeconomic impacts due to the loss of employments. For the land uses occupying large areas (i.e., agriculture, forestry, livestock farming, and photovoltaic parks), an optimisation algorithm is proposed for determining the mix of land uses that maximise revenue, equity, and natural conservation and minimise investment. The algorithm was applied using the opinions of 10 experts, who were involved in mine land reclamation projects carried out in the western Macedonia region in the recent past. According to the results obtained, photovoltaic parks are rated as a more attractive investment than extensive agriculture, as regards the anticipation of revenues, while livestock farming and forests are necessary to safeguard the ecosystem’s functions.
Assessment of the External Costs of Life Cycle of Coal: The Case Study of Southwestern China
Authors: Wang Xiaonan , Wang Licheng , Chen Jianping , Zhang Shouting , Tarolli Paolo
Published: August 2020

Coal will continue to be the main energy source in China for the immediate future, although the environmental pollution and ecological impacts of each stage in the full life cycle of coal mining, transportation, and combustion generate large quantities of external costs. The Late Permian coals in southwestern (SW) China usually contain high amounts of fluorine (F), arsenic (As), and ash, which together with high-F clays cause abnormally high levels of endemic fluorosis, As poisoning, and lung cancer in areas where coal is mined and burned. In this paper, we estimate the external costs of the life cycle of coal. The results show that the externalities of coal in SW China are estimated at USD 73.5 billion or 284.3 USD/t, which would have accounted for 6.5 % of the provincial GDP in this area in 2018. The external cost of human health accounts for 87.2% of the total external costs, of which endemic skeletal fluorosis diseases and related lung cancers have the most important impact. Our study provides a more precise estimate of externalities compared with its counterparts in other provinces in China. Therefore, several policy recommendations would be proposed to internalize the external cost.
Distinct Associations of Hedonic and Eudaimonic Motives with Well-Being: Mediating Role of Self-Control
Authors: Zeng Zhijia , Chen Hezhi
Published: August 2020

The pursuit of hedonia and eudaimonia are two ways to fulfill the goal of a “good life”. While some studies report that both hedonic and eudaimonic motives improve well-being, others suggest that hedonic motives are counterproductive, raising the question of whether and why eudaimonic motives are more positively associated with well-being. We aimed to identify the distinct associations of hedonic and eudaimonic motives with well-being and investigate whether they are partly mediated by self-control. A total of 2882 college freshmen (1835 females, 1047 males, mean age 18.16 years) completed measures assessing hedonic and eudaimonic motives, self-control, life satisfaction, positive and negative affect, and eudaimonic well-being. Eudaimonic motives were associated with higher life satisfaction, more positive affect, less negative affect, and better eudaimonic well-being. In contrast, hedonic motives were positively associated with life satisfaction, while also being correlated with a greater degree of negative affect and impaired eudaimonic well-being. Self-control mediated the relationships between hedonic and eudaimonic motives and well-being. Eudaimonic and hedonic motives were positively and negatively related to self-control, respectively. Further, high self-control was associated with greater life satisfaction, positive affect, and eudaimonic well-being and lower negative affect. Thus, eudaimonic motives can lead to a better life than hedonic motives because the former enhance self-control, while the latter lower it.