bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation of Possibilities to Improve Filtration Efficiency of Tangential Inlet Return Cyclones by Modification of Their Design
Authors: Dziubak Tadeusz
Published: May 2022

It has been shown that tangential inlet return cyclones are commonly used for inlet air filtration of off-road vehicle engines. The wear of the engine elements, and thus their durability, is determined by the efficiency and accuracy of the inlet air filtration. It has been shown that the possibilities of increasing the separation efficiency or decreasing the pressure drop of a cyclone by changing the main dimensions of the cyclone are limited, because any arbitrary change in one of the dimensions of an already operating cyclone may cause the opposite effect. A literature analysis of the possibility of increasing the filtration efficiency of cyclones by modifying the design of selected cyclone components was conducted. In this paper, three modifications of the cyclone design with a tangential inlet of the inlet air filter of a military tracked vehicle were proposed and performed. The symmetrical inlet of the cyclone was replaced with an asymmetrical inlet. The cylindrical outlet tube was replaced with a conical tube, and the edges of the inlet opening were given an additional streamlined shape. The modification process was carried out on three specimens of the reversible cyclone with a tangential inlet. After each modification, an experimental evaluation of the modifications was carried out. The influence of the modifications on the cyclone’s efficiency characteristics and pressure drop was examined. Subsequent modifications of the cyclone were performed on the same specimen without removing the previous modifications. Tests were performed in the air flow range QG = 5–30 m3/h. Polydisperse “fine” test dust with grain size dpmax = 80 µm was used for testing. The dust concentration at the cyclone inlet was set at 1 g/m2. The performed modifications caused a slight (about 1%) increase in separation efficiency in the range of small (up to QG = 22 m3/h) flux values and about 30% decrease in pressure drop in the whole range of the QG flux, which positively influences the increase in engine filling and its power. There was a noticeable increase in filtration accuracy in the range of low and high values of QG flux, which results in a decrease in the wear of engine components, especially the piston-piston ring-cylinder (P-PR-C) association, and an increase in their durability.
Integrated Life Cycle Assessment Modelling of Densified Fuel Production from Various Biomass Species
Authors: Ibrahim Muazu Rukayya , Gadkari Siddharth , Sadhukhan Jhuma
Published: May 2022

This work presents new data on the life cycle impact assessment of various lignocellulosic biomass types in Mexico. A comparative life cycle assessment model of biomass densification systems was conducted. An integrated approach that incorporated various process variables, such as technology and variations in feed properties, within the analysis was employed to evaluate the environmental impact of producing 1 MJ of energy-containing densified fuel. The results show that the densification unit and curing (fuel drying) have the highest impact on the life cycle’s operational energy and the total life cycle energy, respectively. Of all the 33 biomass types from the 17 species sources considered in this study, sweet sorghum and sandbur grass have the highest global warming potential, 0.26 and 0.24 (kg CO2-eq), and human toxicity 0.58 and 0.53 (kg 1,4-dichlorobenzene-eq), respectively, while coffee pulp and cooperi pine wood have the least impact in both categories, with values of 0.08 and 0.09 (kg CO2-eq), and 0.17 and 0.16 (kg 1,4-dichlorobenzene-eq), respectively. Chichicaxtla sawmill slabs also have a low environmental impact, and cooperi pine and Ceiba wood have the lowest ozone depletion and ecotoxicity potential. A sensitivity analysis indicated the effects of the transportation system and energy source on the life cycle’s environmental impact. Adequate feed preparation, the blending of multiple feeds in the optimum ratio, and the careful selection of densification technology could improve the environmental performance of densifying some of the low-bulk-density feed biomass types.
Computational Study on Parametric Variation with Solar Heat Induction of an Entrained Flow Gasifier
Authors: Singh Anirudh , Dhar Atul , Kumar Parmod , Powar Satvasheel
Published: May 2022

Gasification has played an important role in the sustainable use of waste biomass, providing useful combustible gases in the process. Gasification has an important role in waste management and promotes energy independence for many oil-deficit countries. The gasification process has been studied by various researchers, and improvements have been achieved in its sub-processes such as devolatilization, feed input methods, and so on. We examined the influence of gasifier operation parameters, such as oxidizer content, moisture content in the feedstock, and solar flux input inside the gasifier, on the temperature distribution, velocity distribution, and product gas yields of the gasifier. The results indicate that inducing solar energy at different stages of the gasifier leads to different yields of product gas composition (CO and H2).
Performance Analysis of an Ammonia-Fueled Micro Gas Turbine
Authors: Bonasio Vittorio , Ravelli Silvia
Published: May 2022

Micro gas turbines fit perfectly with the energy roadmap to 2050: on-site, small scale power generation, combined with heat recovery from exhaust gas, offers an opportunity to deploy primary energy saving and pollutant emission reduction. Moreover, their flexibility enables fuel switching from natural gas (NG) to carbon-free fuels such as hydrogen and ammonia. This study aims to explore the potential of direct combustion of ammonia in a micro gas turbine (MGT), from a thermodynamic point of view. A modeling procedure was developed to simulate the behavior of a 100 kW MGT operating at full and part-load. After validation with NG as fuel, an increasing fraction of ammonia was fed to the combustor to predict performance variations in terms of electric, thermal and total efficiency, as well as exhaust gas composition, for a load range between 40% and 100%. Additional relevant details, related to the interaction between compressor and turbine in the single-shaft arrangement, were discussed through performance maps. Full replacement of NG with ammonia was found to reduce electric efficiency by about 0.5 percentage points (pp), whatever the power output, with a consequent improvement in exhaust gas heat recovery. Thus, total efficiency is maintained at a high level, with values ranging from 74.5% to 79.1% over the investigated load range. The benefit of zero CO2 emissions can be achieved provided that compressor–turbine matching is adjusted to compensate for the reduction in fuel calorific value: at rated power, when the largest fuel input is required, flow rates of air and flue gas decrease by 4.3% and 2.8%, respectively, with an increase in Brayton cycle pressure ratio of 2%.
Preliminary Study of Various Cross-Sectional Metal Sheet Shapes in Adiabatic Evaporative Cooling Pads
Authors: Prozuments Aleksejs , Brahmanis Arturs , Mucenieks Armands , Jacnevs Vladislavs , Zajecs Deniss
Published: May 2022

As the cooling requirement and the energy prices are increasing rapidly across the world, the need to develop highly efficient cooling equipment is rising as well. Adiabatic cooling employs evaporation to pre-cool the air flowing through a closed-loop coil. This study examines various adiabatic evaporative cooling pads in terms of their pre-cooling potential and advantages over currently available technological solutions through isolating three cross-sectional metal cooling pad shapes (W, Z and Z1). The results of the study suggest that the correlation between Δt↓ and RH↑ is somewhat close in all three cases; however, a slightly higher temperature drop is observed when using a W-shaped metal sheet. Pressure drop variability was negligible under current cooling pad configurations and experimental boundary conditions. Further studies focusing on measurement continuity, longevity and boundary conditions’ variability are recommended.
Application of EOR Using Water Injection in Carbonate Condensate Reservoirs in the Tarim Basin
Authors: Shen Fuxiao , Li Shiyin , Deng Xingliang , Liu Zhiliang , Guo Ping , Wu Guanghui
Published: May 2022

The largest carbonate condensate field has been found in the Tarim Basin, NW China. Different from sandstone condensate gas reservoirs, however, the conventional gas injection for pressure maintenance development is not favorable for Ordovician fracture-cave reservoirs. Based on this, in this paper, 21 sets of displacement experiments in full-diameter cores and a pilot test in 11 boreholes were carried out to study enhanced oil recovery (EOR) in complicated carbonate reservoirs. The experimental results show that the seepage channels of the gas condensate reservoirs are fractures, which are quite different from sandstone pore-throat structures. Condensate oil recovery using water injection was up to 57–88% in unfilled fractured caves and at ca. 52–80% in sand-filled fractured caves. These values are much higher than the 14–46% and 17–58% values obtained from the depletion and gas injection experiments, respectively. The water injection in 11 wells showed that the condensate oil recovery increased by 0–17.7% (avg. 3.1%). The effective EOR for residual oil replacement using water injection may be attributed to fractures, as the gas channel leads to an ineffective gas circulation and pipe flow in fracture-cave reservoirs, which is favorable for waterflood development. The complicated fracture network in the deep subsurface may be the key element in the varied and lower oil recovery rates obtained from the wells than from the experiments. This case study provides new insights for the exploitation of similar condensate gas reservoirs.
Surface-Related and Internal Multiple Elimination Using Deep Learning
Authors: Bao Peinan , Shi Ying , Wang Weihong , Xu Jialiang , Guo Xuebao
Published: May 2022

Multiple elimination has always been a key, challenge, and hotspot in the field of hydrocarbon exploration. However, each multiple elimination method comes with one or more limitations at present. The efficiency and success of each approach strongly depend on their corresponding prior assumptions, in particular for seismic data acquired from complex geological regions. The multiple elimination approach using deep learning encodes the input seismic data to multiple levels of abstraction and decodes those levels to reconstruct the primaries without multiples. In this study, we employ a classic convolution neural network (CNN) with a U-shaped architecture which uses extremely few seismic data for end-to-end training, strongly increasing the neural network speed. Then, we apply the trained network to predict all seismic data, which solves the problem of difficult elimination of global multiples, avoids the regularization of seismic data, and reduces massive amounts of calculation in traditional methods. Several synthetic and field experiments are conducted to validate the advantages of the trained network model. The results indicate that the model has the powerful generalization ability and high calculation efficiency for removing surface-related multiples and internal multiples effectively.
Tax or Clean Technology? Measuring the True Effect on Carbon Emissions Mitigation for Sweden and Norway
Authors: Bonilla David , Banister David , Nieto Uberto Salgado
Published: May 2022

Studies of carbon emissions typically focus on price and tax effects or technology. We argue that the two are closely linked within an economy in disequilibrium. Our goals are twofold: (1) to examine the combined role of: low CO2 technology, fuel taxes and CO2 tax on taming CO2 emissions and (2) to build a counterfactual analysis by capturing anything else that causes emissions to diverge from the trend such as renewable energy, energy laws and the state of the economy. The equilibrium correction model (EqCM) suggests that emissions have a long-term relationship with economic growth, fossil fuel use, taxes and clean power sources. Both oil and gas extraction and economic growth raise Norway’s emissions, offsetting the mitigating effect of taxes. Sweden´s carbon fuel tax elasticity is 20%, a value far above Norway´s elasticity, even though these carbon taxes were phased-in under a period of macroeconomic instability, weakening their effectiveness. The income elasticity of emissions is negative for Norway and positive for Sweden. Emission cuts require (a) de-growth, (b) a higher tax on transport fuels and (c) electrification of transport. The effects of tax, technology, economic growth and those for the pre- and post-carbon tax era differ strongly in the two nations.
Coupling Analysis of Electromagnetic Vibration and Noise of FeCo-Based Permanent-Magnet Synchronous Motor
Authors: Hou Peng , Ge Baojun , Tao Dajun , Wang Yue , Pan Bo
Published: May 2022

Addressing the problem of the vibration and noise of a permanent-magnet synchronous motor (PMSM), this paper optimizes the structure of a permanent-magnet motor rotator, introduces the electromagnetic-structure-acoustic coupling calculation model, and optimizes the motor rotator to reduce the vibration and noise of a permanent-magnet motor. Using the theory of Maxwell’s stress equation, the radial electromagnetic force on the stator teeth of the permanent-magnet motor is deduced and analyzed, and the correctness of the analysis calculation is verified by using the finite element multi-physical field coupling method. Based on the deduced analytical expression of the radial electromagnetic force, the sources of the radial electromagnetic force for each order and the frequency of the permanent-magnet motor are summarized. A 12-slot, 8-pole, permanent-magnet motor is taken as an example. A calculation model considering the spatial distribution of the radial electromagnetic force and the electromagnetic vibration of an iron-cobalt-based stator is established. The harmonic response of the electromagnetic vibration of the motor is analyzed, and a modal analysis is carried out. The optimized acceleration vibration noise cascade of the FeCo-based permanent-magnet drive motor under load is given. The correctness and validity of the theoretical derivation and simulation are verified by experiments.
Integration of Heat Pumps in Buildings and District Heating Systems—Evaluation on a Building and Energy System Level
Authors: Ochs Fabian , Magni Mara , Dermentzis Georgios
Published: May 2022

The use of heat pumps in buildings is one of the best and often the only option for the decarbonization of the building stock. District heating seems a promising solution in urban areas and in existing buildings when the use of heat pumps is restricted and also technically and economically challenging (source exploitation, space restrictions, sound emissions, etc.). Heat pumps can be integrated in various ways in buildings and district heating systems: large central high-temperature heat pumps in district heating, medium-size heat pumps block- or building-wise or small heat pumps decentral apartment-wise. The best option depends on the individual district heating CO2 emissions and the electricity mix as well as on the perspective of the building owner versus that one of the district heating system and its future development. Austrian examples of district heating systems and different variants of integrating heat pumps are investigated in a comprehensive way by means of an energetic and environmental simulation-based analysis. This assessment includes a detailed investigation of the capabilities of the booster heat pump to increase the PV own-consumption and is also expanded to include various scenarios for the development of the electricity mix and the decarbonisation of district heating.
Contributions to Power Management in AC Microgrids Based on Concepts of Microeconomics Theory
Authors: Pinto Luís F. R. , Busarello Tiago D. C. , Bellinaso Lucas V. , Michels Leandro , Mezaroba Marcello
Published: May 2022

Renewable energy sources are growing in importance and reshaping power systems through microgrid (MG) networks. Some relevant issues in the management of an MG need to be addressed, such as voltage and frequency control, power balance between sources (sharing) and distributed loads, stability, security, power quality, etc. As a contribution, this manuscript presents a power management of AC MGs based on concepts of microeconomics theory for market equilibrium. The prices of active and reactive energy are informed through the AC voltage parameters such as magnitude, frequency and angle. This approach allows several sources and loads to operate with no extra communication interface. Experiments are provided to validate operation in many different operational scenarios using a hardware-in-the-loop environment.
Projecting the Thermal Response in a HTGR-Type System during Conduction Cooldown Using Graph-Laplacian Based Machine Learning
Authors: Ross Molly , Lin T-Ying , Gould Daniel , Das Sanjoy , Bindra Hitesh
Published: May 2022

Accurate prediction of an off-normal event in a nuclear reactor is dependent upon the availability of sensory data, reactor core physical condition, and understanding of the underlying phenomenon. This work presents a method to project the data from some discrete sensory locations to the overall reactor domain during conduction cooldown scenarios similar to High Temperature Gas-cooled Reactors (HTGRs). The existing models for conductive cooldown in a heterogeneous multi-body system, such as an assembly of prismatic blocks or pebble beds relies on knowledge of the thermal contact conductance, requiring significant knowledge of local thermal contacts and heat transport possibilities across those contacts. With a priori knowledge of bulk geometry features and some discrete sensors, a machine learning approach was devised. The presented work uses an experimental facility to mimic conduction cooldown with an assembly of 68 cylindrical rods initially heated to 1200 K. High-fidelity temperature data were collected using an infrared (IR) camera to provide training data to the model and validate the predicted temperature data. The machine learning approach used here first converts the macroscopic bulk geometry information into Graph-Laplacian, and then uses the eigenvectors of the Graph-Laplacian to develop Kernel functions. Support vector regression (SVR) was implemented on the obtained Kernels and used to predict the thermal response in a packed rod assembly during a conduction cooldown experiment. The usage of SVR modeling differs from most models today because of its representation of thermal coupling between rods in the core. When trained with thermographic data, the average normalized error is less than 2% over 400 s, during which temperatures of the assembly have dropped by more than 500 K. The rod temperature prediction performance was significantly better for rods in the interior of the assembly compared to those near the exterior, likely due to the model simplification of the surroundings.
The Politics of Market Change towards Sustainability: Revisiting Germany’s Policy Support Framework for Renewables
Authors: Pons-Seres de Brauwer Cristian
Published: May 2022

Legislative efforts for renewables-based energy decarbonisation hinge upon the support and commitment from different stakeholders holding often conflicting positions regarding disruptive processes of socio-technical transformation. However, the evolving acceptance of market actors on the policy-driven promotion of renewables over time remains under-scrutinised. Simultaneously, despite growing attention to power and politics in sustainability transitions, limited efforts remain invested for elucidating the political-economic nature of the market-based selection environments they are operationalised through, highlighting the need for a more systematic comprehension of the “politics of selection”. To address these shortcomings, this paper provides a more refined understanding of the role of policy-driven markets and its participating agents in facilitating/hindering innovation diffusion and broader (system-wide) sustainability transitions. To do so, it showcases a longitudinal case study of the politics underlying Germany’s evolving feed-in policy support framework for orchestrating a market-mediated diffusion of renewables (1980s–2020). Based on policy analysis and semi-structured interviews, the study traces the changing acceptance and ensuing strategic (re)actions of market actors to the emergence and evolution of Germany’s market for electricity from renewable energy sources. Results show how different market participants effectively shape the selection environments they operate in by proactively contesting/deluding the design features of the support policies organising their economised relations (e.g., market entry conditions, exchange rules, remuneration levels, pricing schemes, etc.). Such efforts are undertaken through legal means and market framing strategies targeting the affordability of policy support costs, coupled with the strategic use of policy instrumentation as a vehicle to further expand/retain their market shares to the detriment of competing actors.
Effects of Volumetric Property Models on the Efficiency of a Porous Volumetric Solar Receiver
Authors: Ni Xuewei , Liu Tiening , Liu Dong
Published: May 2022

A porous volumetric receiver is the key component in concentrated solar power systems. In this paper, we investigate the effects of volumetric parameter models on the heat collection efficiency of the volumetric receiver by numerical simulations with the combination of local thermal non-equilibrium and discrete ordinate methods. Seven volumetric convective heat transfer coefficient models and three extinction coefficient models were investigated. The efficiencies calculated using these models were compared among each other. The results show that volumetric convective heat transfer coefficient models have significant effects with a maximum difference of 27.7% in receiver efficiency for these models. Extinction coefficient models have less effects on receiver efficiency with a maximum difference of 7.3%.
Performance Analysis of Ship Exhaust Gas Temperature Differential Power Generation
Authors: Liu Xiaoyu , Zhao Chong , Guo Hao , Wang Zhongcheng
Published: May 2022

In addition to the use of waste heat from the vessel’s exhaust gas to save energy onboard, reduce the carbon emissions of the ship, and combine the characteristics of ship waste heat, mathematical modeling and testing of ship waste heat temperature difference power generation were carried out in this study. Finally, an experimental platform for temperature differential power generation was established to assess the impact of influencing agents on the efficiency of temperature differential power generation. The results show that the effect of different thermally conductive greases on the efficiency of temperature differential power generation tablets is basically the same. In addition, the rate of flow of cooling water, the cooling plate area, and the heat source temperature have more significant effects on the open-circuit voltage and maximum output power. The results show that the maximum power output growth rate increases with increasing cooling water flow, reaching 8.26% at 4 L/min. Likewise, increasing the heat source temperature enhances the maximum output power growth rate by 15.25% at 220 °C. Conversely, the maximum output power of the temperature difference power generation device decreases as the cooling plate area increases, and the maximum output power reduction rate is 15.25% when the cooling plate area is 80 × 200 mm2 compared to the case of using a cooling plate area of 80 × 80 mm2. Moreover, the maximum output power of the temperature differential power generation device reaches 13.6 W under optimal conditions. Assuming that the temperature difference power generation plate is evenly distributed on the tailpipe of the 6260ZCD marine booster diesel engine, it could save approximately 5.44 kW·h electric power per hour and achieve a reduction in CO2 emissions of 0.3435 kg per hour.
Recent Progress in Electromagnetic Interference Shielding Performance of Porous Polymer Nanocomposites—A Review
Authors: Pai Avinash R. , Puthiyaveettil Azeez Nizam , Thankan Binumol , Gopakumar Nandakumar , Jaroszewski Maciej , Paoloni Claudio , Kalarikkal Nandakumar , Thomas Sabu
Published: May 2022

The urge to develop high-speed data transfer technologies for futuristic electronic and communication devices has led to more incidents of serious electromagnetic interference and pollution. Over the past decade, there has been burgeoning research interests to design and fabricate high-performance porous EM shields to tackle this undesired phenomenon. Polymer nanocomposite foams and aerogels offer robust, flexible and lightweight architectures with tunable microwave absorption properties and are foreseen as potential candidates to mitigate electromagnetic pollution. This review covers various strategies adopted to fabricate 3D porous nanocomposites using conductive nanoinclusions with suitable polymer matrices, such as elastomers, thermoplastics, bioplastics, conducting polymers, polyurethanes, polyimides and nanocellulose. Special emphasis has been placed on novel 2D materials such as MXenes, that are envisaged to be the future of microwave-absorbing materials for next-generation electronic devices. Strategies to achieve an ultra-low percolation threshold using environmentally benign and facile processing techniques have been discussed in detail.
Experimental Investigation of the Cooperation of Wind Turbines
Authors: Wiklak Piotr , Kulak Michal , Lipian Michal , Obidowski Damian
Published: May 2022

The article discusses the wind tunnel experimental investigation of two turbines (the downstream unit placed fully in the wake of the upstream one) at various turbulence intensity levels and wind turbine separation distances, at a Reynolds number of approximately 105. The velocity deficit due to the upstream turbine operation is reduced as the wake mixes with the undisturbed flow, which may be enhanced by increasing the turbulence intensity. In a natural environment, this may be provoked by natural wind gusts or changes in the wind inflow conditions. Increased levels of turbulence intensity enlarge the plateau of optimum wind turbine operation—this results in the turbine performance being less prone to variations of tip speed ratio. Another important set of results quantifies the influence of the upstream turbine operation at non-optimal tip speed ratio on the overall system performance, as the downstream machine gains more energy from the wake flow. Thus, all power output maximisation analyses of wind turbine layout in a cluster should encompass not only the locations and distances between the units, but also their operating parameters (TSR, but also pitch or yaw control of the upstream turbine(s)).
A Fractional Step Method to Solve Productivity Model of Horizontal Wells Based on Heterogeneous Structure of Fracture Network
Authors: Xiong Shengchun , Liu Siyu , Weng Dingwei , Shen Rui , Yu Jiayi , Yan Xuemei , He Ying , Chu Shasha
Published: May 2022

The existing productivity models of staged fractured horizontal wells in tight oil reservoir are mainly linear flow models based on the idealized dual-medium fracture network structure, which have a certain limitation when applied to the production prediction. Aiming at the difficulty in describing the shape of the complex fractal fracture network, a two-dimensional heterogeneous structure model of the fracture network is proposed in this paper. Considering the deformation characteristics of porous media and the characteristic of non-Darcy fluid flow, a three-zone steady-state productivity model with the combination of radial and linear flow is established. To eliminate strong nonlinear characteristics of the mathematical model, a fractional step method is employed to deduce the production formulas of staged fractured horizontal wells under infinite and finite conductivity fractures. The established productivity model is verified with the actual data of three horizontal wells in different blocks of S oilfield, and the error between the model calculation results and the actual production data is less than 4%. The analysis results of productivity sensitive factors show that production of horizontal wells is primarily influenced by the reservoir physical properties and fracturing parameters. The steady-state productivity model established in this study can be applied to effectively predict the average production of a horizontal well in stable stage of production, and it has theoretical and practical application value for improving the development effect of tight oil reservoir.
Multi-Energy System Demonstration Pilots on Geographical Islands: An Overview across Europe
Authors: Gabderakhmanova Tatiana , Marinelli Mattia
Published: May 2022

Smart integration of different energy sectors on islands could serve as a key to achieve their energy independence and carbon neutrality goals and facilitate the large-scale penetration of renewables. Demonstration projects play a vital role in testing innovative sector-coupling solutions and exploring their synergies in the real-life environment. They also help to build the required market confidence and awareness, verify and enhance the societal acceptance, and identify and prevent unnecessary risks and complications. The aim of this paper is to provide the reader with a comprehensive review of 19 research projects, which concern the demonstration of sector-coupling technologies on European islands. The projects are funded by the European Commission and started between 2010 and 2020. The review focuses on the exploration of various technical aspects of 28 demo pilots. In addition, it addresses objectives, contributions, and novelty of the demonstrations and analyses barriers, challenges, risks, and success factors reported by project stakeholders. The paper intends to support the decision-makers on the identification, adoption, and replication of successful technologies. Moreover, it provides researchers and other interested parties with lessons learnt to ensure the successful project execution and technology demonstration in future projects.
Algorithm for Rapid Estimation of the Performance of Small Rooftop Solar PV Use by Households
Authors: Stopochkin Artem , Sytnik Inessa
Published: May 2022

The purpose of the research presented in this paper was to develop an analytical instrument for measuring the efficiency of investing in renewable energy sources suitable for use by the average single-family homeowner. The paper develops an algorithm to quickly estimate the efficiency of small rooftop solar photovoltaic (PV) systems use by households. The algorithm is developed on the basis of the MS Excel software package. It is easy to use and allows estimation of the maximum efficiency of the installation of a photovoltaic system, taking into account the preferences of the household, the technical characteristics of the photovoltaic system, and the parameters of the building and location. The validation of the algorithm was carried out on the example of Opole Province (Poland). The selection of photovoltaic panels is based on 17 types of panels made in different technologies, which allows rational choice of modules based on consumer preferences according to the price/quality ratio. The practical use of the developed application should increase the level of informed consumer decision-making in the process of designing a photovoltaic installation and concluding a contract with the installation company.
Design of Moiré-Inspired Metasurface Lens for Focusing Electromagnetic Power in Fresnel Near-Field Region
Authors: Lim Tae-Heung , Kim Hyunsoo , Seo Chulhun , Choo Hosung
Published: May 2022

This paper proposes a Moiré-inspired metasurface lens system to focus electromagnetic power in the Fresnel near-field region. The proposed metasurface lens (MSL) system is composed of two MSLs and a square patch antenna source. The MSLs are modeled based on the transmit phase distributions of Moiré lens theory, and each unit cell structure (patch shape and Jerusalem cross slot shape) is determined to fit the calculated transmit phase distributions at each location. When changing the unit cell structure, phase and transmittance variations are achieved over 330° and −3 dB. The square patch antenna source is then designed to excite the field to the MSLs. The measured reflection coefficients are below −10 dB at 5.8 GHz while rotating the second MSL. The focal length can be adjusted from a minimum of 38 cm to a maximum of 110 cm according to the rotation angle of the second MSL. The proposed MSL system can be employed for wireless power transmission applications to focus electromagnetic power at various locations in the near-field region.
Study of the Thermal Insulation and Flow Field of Vehicle Front Exhaust Pipe
Authors: Li Yuanhong , Han Qing , Xia Dianxiu , Gao Linyu , Hu Jialei , Wang Hongyan , Yi Bin
Published: May 2022

Exhaust is generated by engine flows through a turbocharger, front exhaust pipe, and selective catalytic reduction (SCR) post-treatment device. The structure of the front exhaust pipe affects the temperature, velocity, and turbulent kinetic energy of exhaust and the Sauter Mean Diameter (SMD) of urea water solution (UWS). A high temperature and turbulent kinetic energy in the exhaust will promote the decomposition of UWS, and further accelerate the evaporation and atomization effect of the UWS droplets. Therefore, in order for the exhaust to reach a high temperature and turbulent kinetic energy, a double-layered pipe structure with air insulation was designed. The flow field and the atomization of UWS in the double-layered pipe based on hydroforming processing was investigated through numerical simulation. The thermal insulation simulation was verified by the temperature measurement system and the temperature drops between the double-layered pipe and the volcanic rock-wrapped pipe were also compared. The results indicate that the temperature at the outlet of the designed double-layered pipe was 3.5% higher than that of a single-layered pipe with the same structure, and the velocity at the outlet of the exhaust of the double-layered pipe was 16.1% higher than that of a single-layered pipe. The maximum turbulent kinetic energy in the double-layered pipe was 71 times that of the single-layered pipe. The design is not only conducive to the mixing of UWS and exhaust, but can also improve the atomization performance of UWS.
A Tool for Long-Term Forest Stand Projections of Swedish Forests
Authors: Eriksson Ljusk Ola , Bergh Johan
Published: May 2022

The analysis of forest management strategies at landscape and regional levels forms a vital part of finding viable directions that will satisfy the many services expected of forests. This article describes the structure and content of a stand simulator, GAYA, which has been adapted to Swedish conditions. The main advantage of the GAYA implementation compared to other resources is that it generates a large number of management programmes within a limited time frame. This is valuable in cases where the management programmes appear as activities in linear programming (LP) problems. Two methods that are engaged in the projections, a climate change response function and a soil carbon model, are designed to complement other methods, offering transparency and computational effectiveness. GAYA is benchmarked against projections from the Heureka system for a large set of National Forest Inventory (NFI) plots. The long-term increment for the entire NFI set is smaller for GAYA compared with Heureka, which can be attributed to different approaches for modelling the establishment of new forests. The carbon pool belonging to living trees shows the same trend when correlated to standing volume. The soil carbon pool of GAYA increases with increased standing volume, while Heureka maintains the same amount over the 100-year projection period.
Protein Recovery of Tra Catfish (Pangasius hypophthalmus) Protein-Rich Side Streams by the pH-Shift Method
Authors: Nguyen Hang Thi , Bao Huynh Nguyen Duy , Dang Huong Thi Thu , Tómasson Tumi , Arason Sigurjón , Gudjónsdóttir María
Published: May 2022

Increasing protein demand has led to growing attention being given to the full utilization of proteins from side streams in industrial fish processing. In this study, proteins were recovered from three protein-rich side streams during Tra catfish (Pangasius hypophthalamus) processing (dark muscle; head-backbone; and abdominal cut-offs) by an optimized pH-shift process. Physicochemical characteristics of the resulting fish protein isolates (FPIs) were compared to industrial surimi from the same raw material batch. The pH had a significant influence on protein extraction, while extraction time and the ratio of the extraction solution to raw material had little effect on the protein and dry matter recoveries. Optimal protein extraction conditions were obtained at pH 12, a solvent to raw material ratio of 8, and an extraction duration of 150 min. The resulting FPI contained <10% of the fat and <15% of the ash of the raw material, while the FPI protein recovery was 83.0–88.9%, including a good amino acid profile. All FPIs had significantly higher protein content and lower lipid content than the surimi, indicating the high efficiency of using the pH-shift method to recover proteins from industrial Tra catfish side streams. The FPI made from abdominal cut-offs had high whiteness, increasing its potential for the development of a high-value product.
Improving Nutritional and Health Benefits of Biscuits by Optimizing Formulations Based on Sprouted Pseudocereal Grains
Authors: Paucar-Menacho Luz , Simpalo-López Wilson , Castillo-Martínez Williams , Esquivel-Paredes Lourdes , Martínez-Villaluenga Cristina
Published: May 2022

A mixture design (MD) was used to evaluate the effect of replacing wheat flour (WF) with sprouted cañihua (Chenopodium pallidicaule Aellen), kiwicha (Amarathus caudatus L.), and quinoa (Chenopodium quinoa Willd.) flours (SCF, SKF, and SQF, respectively) on the content of phytic acid (PA), γ-aminobutyric acid (GABA), total soluble phenolic compounds (TSPC), and antioxidant activity (AA) in biscuits. Generally, sprouted pseudocereal flours contained lower amounts of starch and protein, comparable fat, ash, PA content, and increased levels of bioactive compounds (GABA and TSPC) and AA compared with wholegrain flours. Moreover, it was confirmed that sprouted pseudocereal flours were nutritionally superior to refined WF. MD allowed the modeling of target parameters showing that PA, GABA, TSPC, and AA were positively influenced by the proportion of flours in the biscuit. The models that better described the variation in nutritional parameters as a function of the formulation displayed typically linear and binary interactions terms. SKF exerted the highest influence on the increased content of PA. Therefore, to increase mineral bioavailability, the use of SCF and SQF in the formulation of biscuits was suggested. SCF and SQF positively influenced in GABA, TSPC, and AA in biscuits. The optimal ternary blends of flours that maximize the content of bioactive compounds and AA of biscuits and simultaneously minimize PA content were identified. To study the fate of biscuits in digestion, the optimal formulation for biscuits containing SQF/SCF was selected. For this type of baked product, reduced starch digestibility and glycemic index was observed compared with the control (100% WF). Moreover, the amounts of bioaccessible GABA, TSPC, and AA were higher in gastric and intestinal digests compared with control biscuit. Overall, these results highlighted the nutritional and health benefits of incorporation of flours from sprouted Andean grains in the production of biscuits.
Application of Xanthan-Gum-Based Edible Coating Incorporated with Litsea cubeba Essential Oil Nanoliposomes in Salmon Preservation
Authors: Cui Haiying , Yang Mei , Shi Ce , Li Changzhu , Lin Lin
Published: May 2022

Salmon is prone to be contaminated by Vibrio parahaemolyticus (V. parahaemolyticus), leading to the deterioration of salmon quality and the occurrence of food-borne diseases. In this study, we aimed to develop a novel xanthan-gum-based edible coating embedded with nano-encapsulated Litsea cubeba essential oil (LC-EO) for salmon preservation at 4 °C. First, the results of the growth curves and scanning electron microscopy (SEM) showed that LC-EO displayed potent antibacterial activity against V. parahaemolyticus; the optimal concentration of LC-EO in the liposomes was 5 mg/mL, and the maximal encapsulation efficiency (EE) was 37.8%. The particle size, polydispersity coefficient (PDI), and zeta potential of the liposomes were 168.10 nm, 0.250, and −32.14 mV, respectively. The rheological test results of xanthan-gum-based edible coatings incorporating liposomes showed that the prepared coating was suitable for applying on food surfaces. The results in the challenge test at 4 °C demonstrated that the treatment of 1:3 (liposome: xanthan gum, v/v) coating performed the best preservative properties, the coating treatment delayed the oxidation of salmon, and controlled the growth of V. parahaemolyticus. These findings suggest that the coatings formulated in this study could be used as a promising approach to control V. parahaemolyticus contamination and maintain salmon quality.
Changes in Physico-Chemical and Storage Properties of Dry-Aged Beef Loin Using Electric Field Refrigeration System
Authors: Kang Kyu-Min , Lee Sol-Hee , Kim Hack-Youn
Published: May 2022

The aim of this study is to establish the dry aging period of beef loin in an electric field refrigeration system. Beef loins (Korea quality grade 2) were dry aged at 0, −1, and −2 °C temperature in an electric field refrigeration system (air velocity, 5 ± 2 m/s) and aging stopped as the value of TPC reached 7 log CFU/g. Samples were examined by aging yield, trimming yield, pH, color, water holding capacity (WHC), cooking yield, shear force, total plate count (TPC), 2-thiobarbituric acid reactive substances (TBARS), and volatile basic nitrogen (VBN). The results for aging yield, trimming yield, redness, yellowness, and chroma decreased with increasing the dry aging period. Contrariwise, those for pH, lightness, hue angle, WHC, and cooking yield increased with the dry aging period. In shear force, the lowest value occurred at four weeks at all temperatures. The results for TPC, TBARS, and VBN increased with aging period, and VBN at 6 weeks at 0 °C and 9 weeks at −1 °C exceed the standard value (20 mg/100 g), while dry aging temperature had an effect on physico-chemical and storage properties by lower temperatures showed slower progress. Therefore, dry aging on an electric field refrigerate system can be used until 4 weeks at 0 °C, 8 weeks at −1 °C, and 10 weeks at −2 °C. However, considering physico-chemical properties, 4 weeks at every temperature is suitable for manufacturing soft dry-aged beef loin.
Editorial Overview on Emerging Thermal Food Processing Technologies
Authors: Gavahian Mohsen , Majzoobi Mahsa , Farahnaky Asgar
Published: May 2022

In many cases, thermal processing technologies are necessary to provide safe food products [...]
Phytochemical Characterization of Citrus-Based Products Supporting Their Antioxidant Effect and Sensory Quality
Authors: Pieracci Ylenia , Pistelli Laura , Cecchi Massimiliano , Pistelli Luisa , De Leo Marinella
Published: May 2022

The increasing attention on the impact of food on human and environmental health has led to a greater awareness about nutrition, food processing, and food waste. In this perspective, the present work deals with the investigation of the chemical non-volatile and volatile profiles of two Citrus-based products, produced through a conscious process, using Citrus peels as natural gelling agents. Moreover, the total polyphenol content (TPC) and the antioxidant properties were evaluated, as well as their sensorial properties. Chemical and antioxidant results were compared with those of Citrus fresh fruits (C. reticulata, C. sinensis, and C. limon). Concerning the non-volatile fingerprint, the two samples showed a very similar composition, characterized by flavanones (naringenin, hesperetin, and eriodyctiol O-glycosides), flavones (diosmetin and apigenin C-glucosides), and limonoids (limonin, nomilinic acid, and its glucoside). The amount of both flavonoids and limonoids was higher in the Lemon product than in the Mixed Citrus one, as well as the TPC and the antioxidant activity. The aroma composition of the two samples was characterized by monoterpene hydrocarbons as the main chemical class, mainly represented by limonene. The sensorial analysis, finally, evidenced a good quality of both the products. These results showed that the most representative components of Citrus fruits persist even after the transformation process, and the aroma and sensorial properties endow an added value to Citrus preparations.
Wheat Amylase Trypsin Inhibitors Aggravate Intestinal Inflammation Associated with Celiac Disease Mediated by Gliadin in BALB/c Mice
Authors: Yu Tian , Hu Shuai , Min Fangfang , Li Jingjing , Shen Yunpeng , Yuan Juanli , Gao Jinyan , Wu Yong , Chen Hongbing
Published: May 2022

Celiac disease (CD) is an autoimmune intestinal disorder caused by the ingestion of gluten in people who carry the susceptible gene. In current celiac disease research, wheat gluten is often the main target of attention, neglecting the role played by non-gluten proteins. This study aimed to describe the effects of wheat amylase trypsin inhibitors (ATI, non-gluten proteins) and gliadin in BALB/c mice while exploring the further role of relevant adjuvants (cholera toxin, polyinosinic: polycytidylic acid and dextran sulfate sodium) intervention. An ex vivo splenocyte and intestinal tissue were collected for analysis of the inflammatory profile. The consumption of gliadin and ATI caused intestinal inflammation in mice. Moreover, the histopathology staining of four intestinal sections (duodenum, jejunum, terminal ileum, and middle colon) indicated that adjuvants, especially polyinosinic: polycytidylic acid, enhanced the villi damage and crypt hyperplasia in co-stimulation with ATI and gliadin murine model. Immunohistochemical results showed that tissue transglutaminase and IL-15 expression were significantly increased in the jejunal tissue of mice treated with ATI and gliadin. Similarly, the expression of inflammatory factors (TNF-α, IL-1β, IL-4, IL-13) and Th1/Th2 balance also showed that the inflammation response was significantly increased after co-stimulation with ATI and gliadin. This study provided new evidence for the role of wheat amylase trypsin inhibitors in the pathogenesis of celiac disease.