bluuebunny/crossref_metadata_2025 huggingface dataset:
The Communication System and its Impacts on Line Current Differential Protection in Distributed Feeder Automation
Authors: Duan Yilong , Luo Longfu , Li Yong , Cao Yijia
Published: March 2020

As one of the core technologies of distributed feeder automation (DFA), line current differential protection (LCDP) can locate faults quickly and accurately and have the ability to cope with multi-directional flow. However, LCDP algorithm has high requirements for communication speed, and is sensitive to communication quality. In order to apply the LCDP algorithm to a real project, the communication system and its impacts on LCDP need to be studied in depth. In this paper, the design method of a communication system for LCDP, including communication mode, topology, communication protocol, and synchronization, is analyzed in detail. For better parameter determination, the communication models are investigated, and the impact of time delay, data loss, and jitter on LCDP are discussed. Further, the distribution network based on a real project is built in a cyber-physical co-simulation environment, and the impact of electrical fails and communication fails on LCDP are studied. The results show that the design method and parameters determination method proposed in this paper are effective.
Entropy, Entransy and Exergy Analysis of a Dual-Loop Organic Rankine Cycle (DORC) Using Mixture Working Fluids for Engine Waste Heat Recovery
Authors: Wang Shuang , Zhang Wei , Feng Yong-Qiang , Wang Xin , Wang Qian , Liu Yu-Zhuang , Wang Yu , Yao Lin
Published: March 2020

The exergy, entropy, and entransy analysis for a dual-loop organic Rankine cycle (DORC) using a mixture of working fluids have been investigated in this study. A high-temperature (HT) loop was used to recover waste heat from internal combustion engine in 350 °C, and a low-temperature loop (LT) was used to absorb residual heat of engine exhaust gas and HT loop working fluids. Hexane/toluene, cyclopentane/toluene, and R123/toluene were selected as working fluid mixtures for HT loop, while R245fa/pentane was chosen for LT loop. Results indicated that the variation of entropy generation rate, entransy loss, entransy efficiency, and exergy loss are insensitive to the working fluids. The entransy loss rate and system net power output present the same variation trends, whereas a reverse trend for entropy generation rate and entransy efficiency, while the exergy analysis proved to be only utilized under fixed stream conditions. The results also showed that hexane/toluene is the preferred mixture fluid for DORC.
Review of the Low-Enthalpy Lower Cretaceous Geothermal Energy Resources in Poland as an Environmentally Friendly Source of Heat for Urban District Heating Systems
Authors: Pająk Leszek , Tomaszewska Barbara , Bujakowski Wiesław , Bielec Bogusław , Dendys Marta
Published: March 2020

The paper presents a review of the geological and hydrogeological data of the Lower Cretaceous aquifer in the Polish Lowlands and discusses the possibilities for the utilisation of geothermal water resources in existing and new district heating systems. Based on experience related to the use of thermal waters in existing geothermal systems, and using data from the literature, assessments have been made of the energy and environmental effects of the application of low-enthalpy geothermal resources from the Lower Cretaceous aquifer as a source of heat for urban district heating systems. The authors concluded that the implementation of such solutions could result in the production of approximately 4 PJ of geothermal energy annually. To date, these resources have only been developed in three locations—Mszczonów, Uniejów and Poddębice—with the total amount of energy generated annually reaching 100 TJ/year. Similar district heating networks in 120 nearby localities have been also identified. Here, specified geological and hydrogeological conditions enable the extraction of heat from the investigated Lower Cretaceous aquifer, with the aim of using this for heating purposes. To achieve this goal, multiple measures are required, including the following: raising public awareness through appropriate education programmes aimed at the youngest school children; systemic, efficient energy management measures at the central, regional and local levels, and providing financial support and ensuring regulations and laws aimed at improving the development of geothermal resources.
Environmental Sustainability in City Logistics Measures
Authors: Rześny-Cieplińska Jagienka , Szmelter-Jarosz Agnieszka
Published: March 2020

Sustainable urban transport is fundamental not only for economic growth but also for the environmental protection, thus all logistics activities within the cities should be organized in a way to be environmentally friendly. The article aims at presenting the environmental sustainability of city logistics measures from different stakeholder perspectives. In the paper, a multi-method approach was implemented: literature review, text analysis, text mining, and statistical analysis. The paper presents how the stakeholders perceive urban logistics, if they see the need for coordination of its elements, who should be responsible for it, and what areas are the most important for them. The main task of this study is to recognize the priorities of different stakeholders. In consequence, the final effect of this article is an insight that is valuable not only for the local authorities but for many stakeholders, groups operating within the city that are and in many cases cooperating within the framework of creating sustainable urban mobility plans.
Application of Rough Set Theory (RST) to Forecast Energy Consumption in Buildings Undergoing Thermal Modernization
Authors: Szul Tomasz , Kokoszka Stanisław
Published: March 2020

In many regions, the heat used for space heating is a basic item in the energy balance of a building and significantly affects its operating costs. The accuracy of the assessment of heat consumption in an existing building and the determination of the main components of heat loss depends to a large extent on whether the energy efficiency improvement targets set in the thermal upgrading project are achieved. A frequent problem in the case of energy calculations is the lack of complete architectural and construction documentation of the analyzed objects. Therefore, there is a need to search for methods that will be suitable for a quick technical analysis of measures taken to improve energy efficiency in existing buildings. These methods should have satisfactory results in predicting energy consumption where the input is limited, inaccurate, or uncertain. Therefore, the aim of this work was to test the usefulness of a model based on Rough Set Theory (RST) for estimating the thermal energy consumption of buildings undergoing an energy renovation. The research was carried out on a group of 109 thermally improved residential buildings, for which energy performance was based on actual energy consumption before and after thermal modernization. Specific sets of important variables characterizing the examined buildings were distinguished. The groups of variables were used to estimate energy consumption in such a way as to obtain a compromise between the effort of obtaining them and the quality of the forecast. This has allowed the construction of a prediction model that allows the use of a fast, relatively simple procedure to estimate the final energy demand rate for heating buildings.
Numerical Study of the Winter–Kennedy Flow Measurement Method in Transient Flows
Authors: Baidar Binaya , Nicolle Jonathan , Gandhi Bhupendra K. , Cervantes Michel J.
Published: March 2020

This paper explores the possibility of using the Winter–Kennedy (WK) method for transient flow rate measurement in hydraulic turbines. Computational fluid dynamic (CFD) analysis of a numerical model of an axial turbine was carried out for accelerating and decelerating flows. Those were obtained by linearly opening and closing of the guide vanes, respectively, while retaining the inlet pressure constant during the simulations. The behavior of several WK configurations on a cross-sectional plane and along the azimuthal direction of the spiral casing was studied during the transients. The study showed that there are certain WK configurations that are more stable than others. The physical mechanism behind the stability (or instability) of the WK method during transients is presented. Using the steady WK coefficient obtained at the best efficiency point (BEP), the WK method could estimate the transient flow rate with a deviation of about 7.5% and 3.5%, for accelerating and decelerating flow, respectively.
An MPC Scheme with Enhanced Active Voltage Vector Region for V2G Inverter
Authors: Xia Lie , Xu Lianghui , Yang Qingbin , Yu Feng , Zhang Shuangqing
Published: March 2020

In this paper, a model predictive control (MPC) scheme with an enhanced active voltage vector region (AV2R) was developed and implemented to achieve better steady-state performance and lower total harmonic distortion (THD) of the output current for a vehicle-to-grid (V2G) inverter. Firstly, the existing MPC methods conducted with single vector and two vectors during one sampling period were analyzed and the corresponding AV2Rs were elaborated. Secondly, the proposed strategy was investigated, aiming at expanding the AV2R and improving the steady-state performance accordingly. A formal mathematical methodology was studied in terms of duty ratio calculation. Lastly, the proposed method was carried out through experimentation. For comparison, the experimental results of the three mentioned methods were provided as well, proving the effectiveness of the proposed algorithm.
High-Order AVO Inversion for Effective Pore-Fluid Bulk Modulus Based on Series Reversion and Bayesian Theory
Authors: Shi Lei , Sun Yuhang , Liu Yang , Cova David , Liu Junzhou
Published: March 2020

Pore-fluid identification is one of the key technologies in seismic exploration. Fluid indicators play important roles in pore-fluid identification. For sandstone reservoirs, the effective pore-fluid bulk modulus is more susceptible to pore-fluid than other fluid indicators. AVO (amplitude variation with offset) inversion is an effective way to obtain fluid indicators from seismic data directly. Nevertheless, current methods lack a high-order AVO equation for a direct, effective pore-fluid bulk modulus inversion. Therefore, based on the Zoeppritz equations and Biot–Gassmann theory, we derived a high-order P-wave AVO approximation for an effective pore-fluid bulk modulus. Series reversion and Bayesian theory were introduced to establish a direct non-linear P-wave AVO inversion method. By adopting this method, the effective pore-fluid bulk modulus, porosity, and density can be inverted directly from seismic data. Numerical simulation results demonstrate the precision of our proposed method. Model and field data evaluations show that our method is stable and feasible.
Optimum Organic Rankine Cycle Design for the Application in a CHP Unit Feeding a District Heating Network
Authors: Branchini Lisa , De Pascale Andrea , Melino Francesco , Torricelli Noemi
Published: March 2020

Improvement of energy conversion efficiency in prime movers has become of fundamental importance in order to respect EU 2020 targets. In this context, hybrid power plants comprising combined heat and power (CHP) prime movers integrated with the organic Rankine cycle (ORC) create interesting opportunities to additionally increase the first law efficiency and flexibility of the system. The possibility of adding supplementary electric energy production to a CHP system, by converting the prime movers’ exhaust heat with an ORC, was investigated. The inclusion of the ORC allowed operating the prime movers at full-load (thus at their maximum efficiency), regardless of the heat demand, without dissipating not required high enthalpy-heat. Indeed, discharged heat was recovered by the ORC to produce additional electric power at high efficiency. The CHP plant in its original arrangement (comprising three internal combustion engines of 8.5 MW size each) was compared to a new one, involving an ORC, assuming three different layout configurations and thus different ORC off-design working conditions at user thermal part-load operation. Results showed that the performance of the ORC, on the year basis, strongly depended on its part-load behavior and on its regulation limits. Indeed, the layout that allowed to produce the maximum amount of ORC electric energy per year (about 10 GWh/year) was the one that could operate for the greatest number of hours during the year, which was different from the one that exhibited the highest ORC design power. However, energetic analysis demonstrated that all the proposed solutions granted to reduce the global primary energy consumption of about 18%, and they all proved to be a good investment since they allowed to return on the investment in barely 5 years, by selling the electric energy at a minimum price equal to 70 EUR/MWh.
Economic and Exergo-Advance Analysis of a Waste Heat Recovery System Based on Regenerative Organic Rankine Cycle under Organic Fluids with Low Global Warming Potential
Authors: Ochoa Guillermo Valencia , Isaza-Roldan Cesar , Duarte Forero Jorge
Published: March 2020

The waste heat recovery system (WHRS) is a good alternative to provide a solution to the waste energy emanated in the exhaust gases of the internal combustion engine (ICE). Therefore, it is useful to carry out research to improve the thermal efficiency of the ICE through a WHRS based on the organic Rankine cycle (ORC), since this type of system takes advantage of the heat of the exhaust gases to generate electrical energy. The organic working fluid selection was developed according to environmental criteria, operational parameters, thermodynamic conditions of the gas engine, and investment costs. An economic analysis is presented for the systems operating with three selected working fluids: toluene, acetone, and heptane, considering the main costs involved in the design and operation of the thermal system. Furthermore, an exergo-advanced study is presented on the WHRS based on ORC integrated to the ICE, which is a Jenbacher JMS 612 GS-N of 2 MW power fueled with natural gas. This advanced exergetic analysis allowed us to know the opportunities for improvement of the equipment and the increase in the thermodynamic performance of the ICE. The results show that when using acetone as the organic working fluid, there is a greater tendency of improvement of endogenous character in Pump 2 of around 80%. When using heptane it was manifested that for the turbine there are near to 77% opportunities for improvement, and the use of toluene in the turbine gave a rate of improvement of 70%. Finally, some case studies are presented to study the effect of condensation temperature, the pinch point temperature in the evaporator, and the pressure ratio on the direct, indirect, and fixed investment costs, where the higher investment costs were presented with the acetone, and lower costs when using the toluene as working fluid.
Physicochemical Properties of Biodiesel Synthesised from Grape Seed, Philippine Tung, Kesambi, and Palm Oils
Authors: Ong Hwai Chyuan , Mofijur M. , Silitonga A.S. , Gumilang D. , Kusumo Fitranto , Mahlia T.M.I.
Published: March 2020

The production of biodiesel using vegetable oil is an effective way to meet growing energy demands, which could potentially reduce the dependency on fossil fuels. The aim of this study was to evaluate grape seed (Vitis vinifera), Philippine tung (Reutealis trisperma), and kesambi (Schleichera oleosa) oils as potential feedstocks for biodiesel production to meet this demand. Firstly, biodiesels from these oils were produced and then their fatty acid methyl ester profiles and physicochemical properties were evaluated and compared with palm biodiesel. The results showed that the biodiesel produced from grape seed oil possessed the highest oxidation stability of 4.62 h. On the other hand, poor oxidation stability was observed for Philippine tung biodiesel at 2.47 h. The poor properties of Philippine tung biodiesel can be attributed to the presence of α-elaeostearic fatty acid. Furthermore, synthetic antioxidants (pyrogallol) and diesel were used to improve the oxidation stability. The 0.2 wt.% concentration of pyrogallol antioxidant could increase the oxidation stability of grape seed biodiesel to 6.24 h, while for kesambi and Philippine tung, biodiesels at higher concentrations of 0.3% and 0.4 wt.%, respectively, were needed to meet the minimum limit of 8 h. The blending of biodiesel with fossil diesel at different ratios can also increase the oxidation stability.
Privacy-Preserving Peer-to-Peer Energy Trading in Blockchain-Enabled Smart Grids Using Functional Encryption
Authors: Son Ye-Byoul , Im Jong-Hyuk , Kwon Hee-Yong , Jeon Seong-Yun , Lee Mun-Kyu
Published: March 2020

Advanced smart grid technologies enable energy prosumers to trade surplus energy from their distributed renewable energy sources with other peer prosumers through peer-to-peer (P2P) energy trading. In many previous works, P2P energy trading was facilitated by blockchain technology through blockchain’s distributive nature and capacity to run smart contracts. However, the feature that all the data and transactions on a blockchain are visible to all blockchain nodes may significantly threaten the privacy of the parties participating in P2P energy trading. There are many previous works that have attempted to mitigate this problem. However, all these works focused on the anonymity of participants but did not protect the data and transactions. To address this issue, we propose a P2P energy trading system on a blockchain where all bids are encrypted and peer matching is performed on the encrypted bids by a functional encryption-based smart contract. The system guarantees that the information encoded in the encrypted bids is protected, but the peer matching transactions are performed by the nodes in a publicly verifiable manner through smart contracts. We verify the feasibility of the proposed system by implementing a prototype composed of smart meters, a distribution system operator (DSO) server, and private Ethereum blockchain.
Improvement of Flow Distribution by New Inlet Header Configuration with Splitter Plates for Plate-Fin Heat Exchanger
Authors: Peng Xiang , Li Denghong , Li Jiquan , Jiang Shaofei , Gao Qilong
Published: March 2020

The pressure drop increases along with the decrease in the flow maldistribution in the two-stage distributing inlet headers of a plate-fin heat exchanger. To solve this issue, we proposed a new inlet header configuration with splitter plates to decrease the flow maldistribution and pressure drop simultaneously. We used computational fluid dynamic technology to analyze the flow properties in the inlet header configuration and calculated the flow maldistribution degree of the outlet channels and the pressure drop in the inlet header. We performed a sensitivity analysis between the structural parameters, the flow maldistribution degree, and the pressure drop. We determined the optimum values of the structural parameters (the construction of transition duct, the number of splitter plates, the inclined angle of outermost plates, the height of splitter plates, the height of inlet header, etc.), and acquired the optimum configuration of the improved inlet header. Compared with the traditional inlet header, the flow maldistribution degree and pressure drop decreased by 91.5% and 40.9%, respectively, using the proposed improved inlet header with splitter plates, which performed better than the conventional two-stage distribution inlet header.
Computational Modeling of Flexoelectricity—A Review
Authors: Zhuang Xiaoying , Nguyen Binh Huy , Nanthakumar Subbiah Srivilliputtur , Tran Thai Quoc , Alajlan Naif , Rabczuk Timon
Published: March 2020

Electromechanical coupling devices have been playing an indispensable role in modern engineering. Particularly, flexoelectricity, an electromechanical coupling effect that involves strain gradients, has shown promising potential for future miniaturized electromechanical coupling devices. Therefore, simulation of flexoelectricity is necessary and inevitable. In this paper, we provide an overview of numerical procedures on modeling flexoelectricity. Specifically, we summarize a generalized formulation including the electrostatic stress tensor, which can be simplified to retrieve other formulations from the literature. We further show the weak and discretization forms of the boundary value problem for different numerical methods, including isogeometric analysis and mixed FEM. Several benchmark problems are presented to demonstrate the numerical implementation. The source code for the implementation can be utilized to analyze and develop more complex flexoelectric nano-devices.
Advanced Turbine Cycles with Organic Media
Authors: Piwowarski Marian , Kosowski Krzysztof
Published: March 2020

Organic Rankine Cycle (ORC) power plants have become very popular and have found their applications in systems with renewable sources of energy. So far their overall efficiencies are not very impressive and only for the upper temperature of about 300 °C do they exceed 20%. A drawback of these cycles is the limitation of the cycle upper temperature due to the heat exchanger technology and the materials used. However, it is possible to overcome these difficulties by certain modifications of the thermodynamic cycles, a proper choice of the working medium and the optimization of cycle parameters. In the paper the problems of choosing the working medium and the question of higher temperature at the turbine inlet have been discussed. Different modifications of the schemas of the thermodynamic cycles have also been taken into account. The variants of power plants with regenerators, reheaters and heat exchangers have been considered. The proposed increase in temperature (in some cases up to 600 °C or higher) and innovative modifications of the thermodynamic cycles allow to obtain the power plant efficiency of above 50%. The modified cycles have been described in detail in the paper. The proposed cycles equipped with regenerators and reheaters can have the efficiency even slightly higher than classical steam turbine plants with a reheater and regenerators. Appropriate cycle and turbine calculations have been performed for the micro power plants of turbine output in the range of 10 kW–300 kW (up to several MW in some cases). The best arrangements achieved very high values of the overall cycle efficiency.
Patterns of Density and Production in the Community Forests of the Sierra Madre Occidental, Mexico
Authors: Padilla-Martínez Jaime Roberto , Corral-Rivas José Javier , Briseño-Reyes Jaime , Paul Carola , López-Serrano Pablito Marcelo , v. Gadow Klaus
Published: March 2020

The Mexican Sierra Madre Occidental (SMO) represents a region where hundreds of plant species reach the limits of their northern or southern range. The SMO also features a unique cultural diversity, and many communities living within the forest or in its close vicinity depend on the products and services that these forests provide. Our study was based on a large set of remeasured field plots placed in the forests of Durango which are part of the SMO. Using hierarchical clustering, three distinctly different forest types were identified based on structural differences and the relation between stem density and basal area. Maximum forest densities were estimated using a 0.975th quantile regression. Forest production (expressed as current periodic volume increment per unit of area and time) was estimated based on number of stems, forest density, mean height, and forest diversity. Forest density is the principal factors affecting periodic volume production. The discussion presented recommendations for the sustainable use of this unique natural resource. Maintaining minimum levels of residual density is key to ensuring the continued viability of the forests of the Mexican SMO. Future research is needed to identify optimum residual structures, productive residual densities, and desirable levels of biodiversity.
Complete Chloroplast Genome Sequence and Phylogenetic Inference of the Canary Islands Dragon Tree (Dracaena draco L.)
Authors: Celiński Konrad , Kijak Hanna , Wiland-Szymańska Justyna
Published: March 2020

Dracaena draco, which belongs to the genus Dracaena, is an endemic succulent of the Canary Islands. Although it is one of the most popular and widely grown ornamental plants in the world, little is known about its genomic variability. Next generation sequencing, especially in combination with advanced bioinformatics analysis, is a new standard in taxonomic and phylogenetic research. Therefore, in this study, the complete D. draco chloroplast genome (cp) was sequenced and analyzed in order to provide new genomic information and to elucidate phylogenetic relationships, particularly within the genus Dracaena. The D. draco chloroplast genome is 155,422 bp, total guanine-cytosine (GC) content is 37.6%, and it has a typical quadripartite plastid genome structure with four separate regions, including one large single copy region of 83,942 bp length and one small single copy region of 18,472 bp length, separated by two inverted repeat regions, each 26,504 bp in length. One hundred and thirty-two genes were identified, 86 of which are protein-coding genes, 38 are transfer RNAs, and eight are ribosomal RNAs. Seventy-seven simple sequence repeats were also detected. Comparative analysis of the sequence data of various members of Asparagales revealed mutational hotspots potentially useful for their genetic identification. Phylogenetic inference based on 16 complete chloroplast genomes of Asparagales strongly suggested that Dracaena species form one monophyletic group, and that close relationships exist between D. draco, D. cochinchinensis and D. cambodiana. This study provides new and valuable data for further taxonomic, evolutionary and phylogenetic studies within the Dracaena genus.
Improving the Modeling of the Height–Diameter Relationship of Tree Species with High Growth Variability: Robust Regression Analysis of Ochroma pyramidale (Balsa-Tree)
Authors: Zea-Camaño Jorge Danilo , Soto José R. , Arce Julio Eduardo , Pelissari Allan Libanio , Behling Alexandre , Orso Gabriel Agostini , Guachambala Marcelino Santiago , Eisfeld Rozane de Loyola
Published: March 2020

Ochroma pyramidale (Cav. ex. Lam.) Urb. (balsa-tree) is a commercially important tree species that ranges from Mexico to northern Brazil. Due to its low weight and mechanical endurance, the wood is particularly well-suited for wind turbine blades, sporting equipment, boats and aircrafts; as such, it is in high market demand and plays an important role in many regional economies. This tree species is also well-known to exhibit a high degree of variation in growth. Researchers interested in modeling the height–diameter relationship typically resort to using ordinary least squares (OLS) to fit linear models; however, this method is known to suffer from sensitivity to outliers. Given the latter, the application of these models may yield potentially biased tree height estimates. The use of robust regression with iteratively reweighted least squares (IRLS) has been proposed as an alternative to mitigate the influence of outliers. This study aims to improve the modeling of height–diameter relationships of tree species with high growth variation, by using robust regressions with IRLS for data-sets stratified by site-index and age-classes. We implement a split sample approach to assess the model performance using data from Ecuador’s continuous forest inventory (n = 32,279 trees). A sensitivity analysis of six outlier scenarios is also conducted using a subsample of the former (n = 26). Our results indicate that IRLS regression methods can give unbiased height predictions. At face value, the sensitivity analysis indicates that OLS performs better in terms of standard error of estimate. However, we found that OLS suffers from skewed residual distributions (i.e., unreliable estimations); conversely, IRLS seems to be less affected by this source of bias and the fitted parameters indicate lower standard errors. Overall, we recommend using robust regression methods with IRLS to produce consistent height predictions for O. pyramidale and other tree species showing high growth variation.
A Review of the Control Plane Scalability Approaches in Software Defined Networking
Authors: Abuarqoub Abdelrahman
Published: March 2020

Recent advances in information and communications cloud-based services hold the potential to overcome the scalability and complex maintenance limitations of traditional networks. Software Defined Networking (SDN) surfaced as a promising paradigm to mitigate such limitations while offering flexible networks management. Particularly, SDN separates the control plane from the data plane to achieve abstraction of lower-level functionality, hence, allowing more efficient network management and utilization. However, SDN suffers from various performance and scalability problems leading to significant research efforts on maximizing the scalability of the control plane. This paper aims at reviewing different SDN controller scalability, topology-based and mechanism-based approaches, as well as discussing and analyzing how they attempt to solve the scalability challenge. Furthermore, this paper elaborates on the promising research trends and challenges. Our insights are also discussed to stimulate further research efforts addressing the control plane scalability in SDN.
Wild Lactobacillus casei Group Strains: Potentiality to Ferment Plant Derived Juices
Authors: Bancalari Elena , Castellone Vincenzo , Bottari Benedetta , Gatti Monica
Published: March 2020

Plant derived beverages have recently gained consumers’ interest, particularly due to their intrinsic functional properties. They can also act as non-dairy carriers for probiotics and prebiotics, meeting the needs of lactose allergic/intolerant people and vegans. Direct fermentation of fruit and vegetables juices by probiotic lactic acid bacteria could be a tool to increase safety, shelf-life, nutrients bioavailability and to improve sensorial features of plant derived juices. This study aims to screen wild Lactobacillus casei-group strains isolated from dairy matrices for probiotic features, such as acid and bile salts resistance, and test them for the potentiality to ferment celery and orange juices. Strains’ ability to produce exopolysaccharides (EPS) in situ is also checked. These evaluations were performed for the first time in fruit and vegetables matrices by means of an impedometric analysis, recently shown to be a suitable and rapid method to measure microorganisms’ growth, acidification performances and EPS production. This study allowed the selection of three potentially probiotic L. casei-group wild strains able to ferment fruit and vegetable juices and also producing EPS. These strains with three-in-one abilities could be used to produce new functional fermented plant derived juices.
Current Advances in Meat Nutritional, Sensory and Physical Quality Improvement
Authors: Gagaoua Mohammed , Picard Brigitte
Published: March 2020

Meat is an important source of proteins, vitamins, minerals and fat, and these nutrients are important for their beneficial effects on human health. In recent years, meat quality has become a more relevant topic for consumers with regard to health and sensory characteristics, and for beef industry stakeholders because it affects their profitability. Therefore, the control of meat quality, including technological, sensory and nutritional quality traits, constitutes an important target for any farm animal production. What those qualities are and how we best evaluate them at the different levels of the continuum from the farm to fork are critical to understanding meat production and consumption patterns. However, despite the efforts of the industrials to control the eating and nutritional quality traits of meat and meat products, there remains a high level of variability, which is one reason for consumer dissatisfaction. This Special Issue focuses on the study of continuum aspects from farm to fork, which would have an impact on the control of the nutritional, sensory and technological aspects of carcass, muscle, meat and meat-product qualities. It groups fourteen original studies and one comprehensive review within five main topics that are (i) production systems and rearing practices, (ii) prediction of meat qualities, (iii) statistical approaches for meat quality prediction/management, (iv) muscle biochemistry and proteomics techniques and (v) consumer acceptability, development and characterisation of meat products.
Nanostructured Lipid-Based Delivery Systems as a Strategy to Increase Functionality of Bioactive Compounds
Authors: Gasa-Falcon Ariadna , Odriozola-Serrano Isabel , Oms-Oliu Gemma , Martín-Belloso Olga
Published: March 2020

Acquisition of a healthy lifestyle through diet has driven the food manufacturing industry to produce new food products with high nutritional quality. In this sense, consumption of bioactive compounds has been associated with a decreased risk of suffering chronic diseases. Nonetheless, due to their low solubility in aqueous matrices, high instability in food products during processing and preparation as well as poor bioavailability, the use of such compounds is sometimes limited. Recent advancements in encapsulation and protection of bioactive compounds has opened new possibilities for the development of novel food products. In this direction, the present review is attempting to describe encapsulation achievements, with special attention to nanostructured lipid-based delivery systems, i.e., nanoemulsions, multi-layer emulsions and liposomes. Functionality of bioactive compounds is directly associated with their bioavailability, which in turn is governed by several complex processes, including the passage through the gastrointestinal tract and transport to epithelial cells. Therefore, an overview of recent research on the properties of these nanostructured lipid-based delivery systems with a strong impact on the functionality of bioactive compounds will be also provided. Nanostructured lipid-based delivery systems might be used as a potential option to enhance the solubility, stability, absorption and, ultimately, functionality of bioactive compounds. Several studies have been performed in this line, modifying the composition of the nanostructures, such as the lipid-type or surfactants. Overall, influencing factors and strategies to improve the efficacy of encapsulated bioactive compounds within nanostructures have been successfully identified. This knowledge can be used to design effective targeted nanostructured lipid-based delivery systems for bioactive compounds. However, there is still a lack of information on food interactions, toxicity and long-term consumption of such nanostructures.
Genetically Modified Micro-Organisms for Industrial Food Enzyme Production: An Overview
Authors: Deckers Marie , Deforce Dieter , Fraiture Marie-Alice , Roosens Nancy H.C.
Published: March 2020

The use of food enzymes (FE) by the industrial food industry is continuously increasing. These FE are mainly obtained by microbial fermentation, for which both wild-type (WT) and genetically modified (GM) strains are used. The FE production yield can be increased by optimizing the fermentation process, either by using genetically modified micro-organism (GMM) strains or by producing recombinant enzymes. This review provides a general overview of the different methods used to produce FE preparations and how the use of GMM can increase the production yield. Additionally, information regarding the construction of these GMM strains is provided. Thereafter, an overview of the different European regulations concerning the authorization of FE preparations on the European market and the use of GMM strains is given. Potential issues related to the authorization and control of FE preparations sold on the European market are then identified and illustrated by a case study. This process highlighted the importance for control of FE preparations and the consequent need for appropriate detection methods targeting the presence of GMM, which is used in fermentation products.
Comparative Study on Mixing Behavior of Binary Mixtures of Cocoa Butter/Tristearin (CB/TS) and Cocoa Butter/Coconut Oil (CB/CO)
Authors: Joshi Bhagyashri L. , Zielbauer Birgitta I. , Vilgis Thomas A.
Published: March 2020

The comparative study between the mixing behavior of two binary mixtures of cocoa butter (CB)/tristearin (TS) and cocoa butter (CB)/coconut oil (CO) was investigated by using differential scanning calorimetry (DSC). The DSC profile for CB/TS blends resulted in a monotectic temperature–concentration (T–X) phase diagram, whereas a phase diagram of eutectic type was observed for CB/CO blends at 65 wt % of CO and 35 wt % CB; this suggests that the eutectic crystal can be formed when the saturated fat (blue = CO) is smaller in size compared to monounsaturated fat (orange = CB), whereas, for similar and larger size (red = TS) to CB, phase separation under crystallization is likely to occur (as shown in the graphical abstract). In order to understand the interaction between the binary systems, the profile of the phase diagram was fitted with Bragg–Williams approximation for estimation of the nonideality mixing parameter. Moreover, the morphology of the two different systems by polarized light microscopy (PLM) also depicted the variations in phase behavior by showing a significant change in CB morphology from spherulitic, grainy to granular and needlelike after the addition of TS and CO, respectively. Our findings emphasize the fundamental understanding of the interaction of bulk fat/fat and fat/oil system.
Effects of Boswellia Serrata and Whey Protein Powders on Physicochemical Properties of Pork Patties
Authors: Yang Fengqi , Cho Won-Young , Lee Nayeon , Kim Da-Hee , Lee Jihye , Lee Hyun-Jin , Seo Han Geuk , Lee Chi-Ho
Published: March 2020

Processed meat products are prone to oxidative damage and quality decline during storage; however, these problems can be mitigated by the proper formulation of meat productions. This study evaluated the effects of natural anti-oxidants found in Boswellia serrata (B), whey protein powder (W), and their combination on pork patties during storage, exploring changes in textural properties and lipid oxidation susceptibility. The 2% whey-added group exhibited a higher crude protein content than the untreated control group. The highest water-holding capacity and lowest cooking losses were observed in mixed-additive groups (WB1 (2% W/0.5% B) and WB2 (2% W/1.0% B), and the highest sensory scores for overall acceptability were obtained for WB1. Adding B. serrata can neutralize the hardness caused by whey powder, thereby improving palatability. From 7 d (days 7), the extents of lipid oxidation, determined using 2-thiobarbituric acid-reactive substances (TBARS) analysis, for the WB1 and WB2 groups were significantly lower than that of the control group. The WB1 and WB2 groups exhibited substantially suppressed total bacterial colony and Escherichia coli counts relative to the control group. Our findings suggest that the additive combination of B. serrata and whey protein powders can suppress lipid oxidation, improve storage stability, and enhance textural properties in the production of functional pork patties.
Production of Probiotic Passion Fruit (Passiflora edulis Sims f. flavicarpa Deg.) Drink Using Lactobacillus reuteri and Microencapsulation via Spray Drying
Authors: Santos Monteiro Shênia , Albertina Silva Beserra Yolanda , Miguel Lisboa Oliveira Hugo , Pasquali Matheus
Published: March 2020

Probiotic foods offer many benefits to human health, causing increased interest in the development of new food products that exploit such benefits. However, traditional dairy foods are being replaced by other non-dairy foods to provide additional sources of benefits provided by bioactive molecules. Therefore, the objective of the present work was to study the production process of a probiotic fruit drink and then microencapsulate the probiotic pulp to stabilize the drink further. Passion fruit pulp (Passiflora edulis Sims f. flavicarpa Deg.) was fermented with Lactobacillus reuteri under different temperature conditions in combination with different pHs to find the best fermentation conditions. Different from dairy sources, the optimal conditions for the growth of Lactobacillus reuteri in the passion fruit pulp were found to be 30 °C at pH 3.18, where phenolic compounds could also be used as a secondary metabolic pathway. Spray-drying was performed using different conditions for microencapsulation. Process yields and Lactobacillus reuteri survival showed the dependency of droplet sizes, whereas phenolic compound retention was increased when higher amounts of gelatin were used. Therefore, the development of a new food product comprising a powdered fruit pulp rich in probiotic and phenolic compounds was possible.
Transcriptomic Profiling of DAF-7/TGFβ Pathway Mutants in C. elegans
Authors: Hu Muhan , Crossman David , Prasain Jeevan K. , Miller Michael A. , Serra Rosa A.
Published: March 2020

The transforming growth factor beta superfamily encompasses a large family of ligands that are well conserved across many organisms. They are regulators of a number of physiological and pathological processes. The model nematode Caenorhabditis elegans has been instrumental in identifying key components of the transforming growth factor beta (TGFβ) pathway. In C. elegans, the TGFβ homolog DAF-7 signals through the DAF-1 Type I and DAF-4 Type II receptors to phosphorylate downstream R-SMADs DAF-8 and DAF-14. These R-SMADs translocate into the nucleus to inhibit Co-SMAD DAF-3. Many of the roles of the canonical DAF-7 pathway, involving both DAF-1 and DAF-3, have been identified using targeted genetic studies. Few have assessed the global transcriptomic changes in response to these genes, especially in adult animals. In this study, we performed RNA sequencing on wild type, daf-1, and daf-1; daf-3 adult hermaphrodites. To assess the overall trends of the data, we identified differentially expressed genes (DEGs) and performed gene ontology analysis to identify the types of downstream genes that are differentially expressed. Hierarchical clustering showed that the daf-1; daf-3 double mutants are transcriptionally more similar to wild type than daf-1 mutants. Analysis of the DEGs showed a disproportionally high number of genes whose expression is increased in daf-1 mutants, suggesting that DAF-1 acts as a general repressor of gene expression in wild type animals. Gene ontology analysis of the DEGs produced many significantly enriched terms, including Molting Cycle, Response to Topologically Incorrect Protein, and Response to Biotic Stimulus. Understanding the direct and indirect targets of the DAF-7 TGFβ pathway through this RNA-seq dataset can provide insight into novel roles of the multifunctional signaling pathway, as well as identify novel genes that may participate in previously reported functions of TGFβ signaling.
The Role of Olfactory Genes in the Expression of Rodent Paternal Care Behavior
Authors: Rymer Tasmin L.
Published: March 2020

Olfaction is the dominant sensory modality in rodents, and is crucial for regulating social behaviors, including parental care. Paternal care is rare in rodents, but can have significant consequences for offspring fitness, suggesting a need to understand the factors that regulate its expression. Pup-related odor cues are critical for the onset and maintenance of paternal care. Here, I consider the role of olfaction in the expression of paternal care in rodents. The medial preoptic area shares neural projections with the olfactory and accessory olfactory bulbs, which are responsible for the interpretation of olfactory cues detected by the main olfactory and vomeronasal systems. The olfactory, trace amine, membrane-spanning 4-pass A, vomeronasal 1, vomeronasal 2 and formyl peptide receptors are all involved in olfactory detection. I highlight the roles that 10 olfactory genes play in the expression of direct paternal care behaviors, acknowledging that this list is not exhaustive. Many of these genes modulate parental aggression towards intruders, and facilitate the recognition and discrimination of pups in general. Much of our understanding comes from studies on non-naturally paternal laboratory rodents. Future studies should explore what role these genes play in the regulation and expression of paternal care in naturally biparental species.
Inferring Effective Population Size and Divergence Time in the Lithuanian Population According to High-Density Genotyping Data
Authors: Urnikytė Alina , Molytė Alma , Pranckevičienė Erinija , Kučinskienė Zita Aušrelė , Kučinskas Vaidutis
Published: March 2020

The prehistory of the Lithuanian population and genetic relationship to other populations are poorly studied. Thus, the Lithuanian population, as an object of study, is interesting due to its partial isolation with genetic distinctiveness within the European context and with preserved ancient genetic composition. The main objects of this study was to infer demographic parameters, effective population size (Ne), and divergence time using high-density single nucleotide polymorphism (SNP) genotyping data generated with the Illumina HumanOmmiExpress-12v1.1 array in 295 individuals from the Lithuanian population and to compare our data with other populations from the Human Genome Cell Line Diversity Panel (HGDP-CEPH). We also aimed to reconstruct past events between the main ethnolinguistic regions—Aukštaitija and Žemaitija of Lithuania. Historically, these regions probably developed as two independent Baltic tribes. Our results of Ne in the Lithuanian population through time demonstrated a substantial reduction of Ne over the 150,000–25,000 years before present (YBP). The estimated long-term Ne of the Lithuanian population is quite low—it equals 5404, which likely is a consequence of the bottlenecks associated with the last glacial period of 25,000–12,000 YBP in Europe. The obtained divergence time estimates between the study populations are in agreement with recent studies. The reconstructed past events in Aukštaitija and Žemaitija showed significant differences between these two regions of Lithuania.
Dissecting the Genetic Basis of Variation in Drosophila Sleep Using a Multiparental QTL Mapping Resource
Authors: R. Smith Brittny , J. Macdonald Stuart
Published: March 2020

There is considerable variation in sleep duration, timing and quality in human populations, and sleep dysregulation has been implicated as a risk factor for a range of health problems. Human sleep traits are known to be regulated by genetic factors, but also by an array of environmental and social factors. These uncontrolled, non-genetic effects complicate powerful identification of the loci contributing to sleep directly in humans. The model system, Drosophila melanogaster, exhibits a behavior that shows the hallmarks of mammalian sleep, and here we use a multitiered approach, encompassing high-resolution QTL mapping, expression QTL data, and functional validation with RNAi to investigate the genetic basis of sleep under highly controlled environmental conditions. We measured a battery of sleep phenotypes in >750 genotypes derived from a multiparental mapping panel and identified several, modest-effect QTL contributing to natural variation for sleep. Merging sleep QTL data with a large head transcriptome eQTL mapping dataset from the same population allowed us to refine the list of plausible candidate causative sleep loci. This set includes genes with previously characterized effects on sleep and circadian rhythms, in addition to novel candidates. Finally, we employed adult, nervous system-specific RNAi on the Dopa decarboxylase, dyschronic, and timeless genes, finding significant effects on sleep phenotypes for all three. The genes we resolve are strong candidates to harbor causative, regulatory variation contributing to sleep.