bluuebunny/crossref_metadata_2025 huggingface dataset:
Conceptual Design of a Novel Unmanned Ground Effect Vehicle (UGEV) and Flow Control Integration Study
Authors: Papadopoulos Charalampos , Mitridis Dimitrios , Yakinthos Kyros
Published: January 2022

In this study, the conceptual design of an unmanned ground effect vehicle (UGEV), based on in-house analytical tools and CFD calculations, followed by flow control studies, is presented. Ground effect vehicles can operate, in a more efficient way, over calm closed seas, taking advantage of the aerodynamic interaction between the ground and the vehicle. The proposed UGEV features a useful payload capacity of 300 kg and a maximum range of 300 km cruising at 100 kt. Regarding the aerodynamic layout, a platform which combines the basic geometry characteristics of the blended wing body (BWB), and box wing (BXW) configurations is introduced. This hybrid layout aims to incorporate the most promising features from both configurations, while it enables the UGEV to operate under adverse flight conditions of the atmospheric boundary layer of the earth. In order to enhance the performance characteristics of the platform, both passive and active flow control techniques are studied and incorporated into the conceptual design phase of the vehicle. For the passive flow control techniques, the adaptation of tubercles and wing fences is evaluated. Regarding the active flow control techniques, a wide range of morphing technologies is investigated based on performance and integration criteria. Finally, stability studies are conducted for the proposed platform.
Inferring a Property of a Large System from a Small Number of Samples
Authors: Hernández Damián G. , Samengo Inés
Published: January 2022

Inferring the value of a property of a large stochastic system is a difficult task when the number of samples is insufficient to reliably estimate the probability distribution. The Bayesian estimator of the property of interest requires the knowledge of the prior distribution, and in many situations, it is not clear which prior should be used. Several estimators have been developed so far in which the proposed prior us individually tailored for each property of interest; such is the case, for example, for the entropy, the amount of mutual information, or the correlation between pairs of variables. In this paper, we propose a general framework to select priors that is valid for arbitrary properties. We first demonstrate that only certain aspects of the prior distribution actually affect the inference process. We then expand the sought prior as a linear combination of a one-dimensional family of indexed priors, each of which is obtained through a maximum entropy approach with constrained mean values of the property under study. In many cases of interest, only one or very few components of the expansion turn out to contribute to the Bayesian estimator, so it is often valid to only keep a single component. The relevant component is selected by the data, so no handcrafted priors are required. We test the performance of this approximation with a few paradigmatic examples and show that it performs well in comparison to the ad-hoc methods previously proposed in the literature. Our method highlights the connection between Bayesian inference and equilibrium statistical mechanics, since the most relevant component of the expansion can be argued to be that with the right temperature.
Immunity in the ABM-DSGE Framework for Preventing and Controlling Epidemics—Validation of Results
Authors: Kaszowska-Mojsa Jagoda , Włodarczyk Przemysław , Szymańska Agata
Published: January 2022

The COVID-19 pandemic has raised many questions on how to manage an epidemiological and economic crisis around the world. Since the beginning of the COVID-19 pandemic, scientists and policy makers have been asking how effective lockdowns are in preventing and controlling the spread of the virus. In the absence of vaccines, the regulators lacked any plausible alternatives. Nevertheless, after the introduction of vaccinations, to what extent the conclusions of these analyses are still valid should be considered. In this paper, we present a study on the effect of vaccinations within the dynamic stochastic general equilibrium model with an agent-based epidemic component. Thus, we validated the results regarding the need to use lockdowns as an efficient tool for preventing and controlling epidemics that were obtained in November 2020.
Gamification as a Teaching Method to Improve Performance and Motivation in Tertiary Education during COVID-19: A Research Study from Mexico
Authors: Rincon-Flores Elvira G. , Mena Juanjo , López-Camacho Eunice
Published: January 2022

Gamification is usually understood as a pedagogical strategy that favors student engagement and motivation. Traditionally it is composed of dynamics, mechanics, and components. The purpose of this study was to compare Engineering and Economics and Social Sciences undergraduate students in their performance (grades), motivation, quality of assignments, participation, and emotion when their teachers used gamification as an innovative teaching method during the COVID-19 pandemic. Pearson correlations, Principal Component Analysis (PCA), and Mann–Whitney test were conducted. Additionally, four students were interviewed to describe the emotional downside of the lockdown. The main results indicate that there are higher positive relationships among variables in the Engineering undergraduate students rather than in Economics and Social Sciences and show that emotion poorly correlates with performance, especially for the Economics and Social Sciences students, as many have a negative attitude toward learning mathematics. Additionally, gender and scholarship status are not differential factors. Gamification proved to be a useful pedagogical strategy to promote participation and enhance motivation among undergraduate students, particularly in a context of academic confinement. This study gives teachers an idea of the benefits and extent to which gamification can be used in the classroom.
What Do Preschool Teachers and Parents Think about the Influence of Screen-Time Exposure on Children’s Development? Challenges and Opportunities
Authors: Monteiro Rita , Fernandes Sandra , Rocha Nuno
Published: January 2022

Children’s exposure to screens has been increasing in recent years and so has the concern about its impact on children’s development. This study aims to analyze preschool teachers’ and parents’ views on the influence of screen-time exposure on children’s development. Semi-structured interviews with preschool teachers (n = 9), as well as data from a previous quantitative study, based on an online questionnaire applied to parents of children in preschool (n = 266) were used for data collection. For this study, eminently of qualitative nature, the following dimensions were analyzed: children’s habits of exposure to screens at home, changes in children’s play habits at school, strategies/methodologies used by preschool teachers, use of technologies at school and children’s language development. The results from the study with parents show that screen-time exposure of children is between 1 h to 2 h of television per day, mostly to watch cartoons. Parents also report that most of the children use vocabulary in other languages at home. Most preschool teachers agreed that children are changing their play habits and mainly their behaviors and attitudes, influenced by screen-time exposure. They believe that language development is also changing, mentioning more language problems in children. Changes in pedagogic strategies and specialized training on educational technology are needed to get closer to children’s interests.
Local and Global Feature Aggregation-Aware Network for Salient Object Detection
Authors: Da Zikai , Gao Yu , Xue Zihan , Cao Jing , Wang Peizhen
Published: January 2022

With the rise of deep learning technology, salient object detection algorithms based on convolutional neural networks (CNNs) are gradually replacing traditional methods. The majority of existing studies, however, focused on the integration of multi-scale features, thereby ignoring the characteristics of other significant features. To address this problem, we fully utilized the features to alleviate redundancy. In this paper, a novel CNN named local and global feature aggregation-aware network (LGFAN) has been proposed. It is a combination of the visual geometry group backbone for feature extraction, an attention module for high-quality feature filtering, and an aggregation module with a mechanism for rich salient features to ease the dilution process on the top-down pathway. Experimental results on five public datasets demonstrated that the proposed method improves computational efficiency while maintaining favorable performance.
Sensitivity Analysis for Vulnerability Mitigation in Hybrid Networks
Authors: Ur-Rehman Attiq , Gondal Iqbal , Kamruzzaman Joarder , Jolfaei Alireza
Published: January 2022

The development of cyber-assured systems is a challenging task, particularly due to the cost and complexities associated with the modern hybrid networks architectures, as well as the recent advancements in cloud computing. For this reason, the early detection of vulnerabilities and threat strategies are vital for minimising the risks for enterprise networks configured with a variety of node types, which are called hybrid networks. Existing vulnerability assessment techniques are unable to exhaustively analyse all vulnerabilities in modern dynamic IT networks, which utilise a wide range of IoT and industrial control devices (ICS). This could lead to having a less optimal risk evaluation. In this paper, we present a novel framework to analyse the mitigation strategies for a variety of nodes, including traditional IT systems and their dependability on IoT devices, as well as industrial control systems. The framework adopts avoid, reduce, and manage as its core principles in characterising mitigation strategies. Our results confirmed the effectiveness of our mitigation strategy framework, which took node types, their criticality, and the network topology into account. Our results showed that our proposed framework was highly effective at reducing the risks in dynamic and resource constraint environments, in contrast to the existing techniques in the literature.
Capacitor Voltage Balancing of a Grid-Tied, Cascaded Multilevel Converter with Binary Asymmetric Voltage Levels Using an Optimal One-Step-Ahead Switching-State Combination Approach
Authors: Kuder Manuel , Kersten Anton , Marques-Lopez Jose-Luis , Estaller Julian , Buberger Johannes , Schwitzgebel Florian , Thiringer Torbjörn , Lesnicar Anton , Marquardt Rainer , Weyh Thomas , Eckerle Richard
Published: January 2022

This paper presents a novel capacitor voltage balancing control approach for cascaded multilevel inverters with an arbitrary number of series-connected H-Bridge modules (floating capacitor modules) with asymmetric voltages, tiered by a factor of two (binary asymmetric). Using a nearest-level reference waveform, the balancing approach uses a one-step-ahead approach to find the optimal switching-state combination among all redundant switching-state combinations to balance the capacitor voltages as quickly as possible. Moreover, using a Lyapunov function candidate and considering LaSalle’s invariance principle, it is shown that an offline calculated trajectory of optimal switching-state combinations for each discrete output voltage level can be used to operate (asymptotically stable) the inverter without measuring any of the capacitor voltages, achieving a novel sensorless control as well. To verify the stability of the one-step-ahead balancing approach and its sensorless variant, a demonstrator inverter with 33 levels is operated in grid-tied mode. For the chosen 33-level converter, the NPC main-stage and the individual H-bridge modules are operated with an individual switching frequency of about 1 kHz and 2 kHz, respectively. The sensorless approach slightly reduced the dynamic system response and, furthermore, the current THD for the chosen operating point was increased from 3.28 to 4.58 in comparison with that of using the capacitor voltage feedback.
Designing a Monitoring System to Observe the Innovative Single-Wire and Wireless Energy Transmitting Systems in Explosive Areas of Underground Mines
Authors: Kianfar Amir Ehsan , Sherikar Mrityunjaya , Gilerson Andre , Skora Marcin , Stankiewicz Krzysztof , Mitra Rudrajit , Clausen Elisabeth
Published: January 2022

Suspended monorails are a common mode of transportation for materials and personnel in underground mines. The goal of the EU-funded project “Innovative High Efficiency Power System for Machines and Devices, Increasing the Level of Work Safety in Underground Mining Excavations (HEETII)” is to introduce a single-wire energy transmission system combined with a capacitive-coupling-based wireless transmission system to power the suspended tractor, along with a monitoring system that will monitor the energy network and additional environmental parameters of the mine. Additionally, the monitoring system acts as the wireless communication backbone, allowing for data transmission to surface headquarters, where the data are processed and logged in a central database. This enables operators to detect and take preemptive measures to prevent potential hazards in the mine, improving the overall efficiency of the energy transmission system. This paper describes the additional considerations required for electrical systems in underground mines with potentially explosive atmospheres, as well as the design of the energy transmission system and the monitoring system.
Investigation of Suction Flow Control on Centrifugal Compressor with Vaned Diffuser
Authors: Ak Suleyman , Cadirci Sertac
Published: January 2022

In this study, the effect of suction flow control on a centrifugal compressor at operation and stall flow rates was investigated using computational fluid dynamics (CFD). The compressor geometry was reconstructed from available open source profile data and the CFD analyses have been performed on this geometry using the appropriate mesh. To validate the CFD results, the compressor performance line was acquired and compared with the experimental results obtained at the design rotational speed. Then, suction flow control was employed at various suction slot positions with different suction flow rates to improve the performance of the compressor at operation and stall flow rates. As a result of the suction flow control trials, 0.85% increase in pressure ratio and 0.8% increase in adiabatic efficiency were achieved while the compressor was running at operation flow rate. The performance improvements corresponding to the stall flow rate of the compressor were 2.5% increase in pressure ratio and 2% increase in adiabatic efficiency.
Efficiency of PBT Impellers with Different Blade Cross-Sections
Authors: Stelmach Jacek , Musoski Radosław , Kuncewicz Czesław , Jirout Tomas , Rieger Frantisek
Published: January 2022

In this study, the mixing power and the axial and radial velocity distributions were determined for the standard PBT45-6 impeller with inclined blades and for three NACA impellers with airfoil blades. On the basis of the velocity distributions obtained by means of PIV techniques, the pumping efficiency and the size of the secondary circulation for the tested impellers were determined. The next stage was to calculate the efficiency of the impeller operation, in which the comparative criteria were the values of the mixing energy in the form of a dimensional and dimensionless criterion. The lowest mixing energy was obtained for impellers with symmetrical profiled NACA0021 blades, which was 20% lower than the similar mixing energy obtained for the standard PBT45-6 impeller.
Utilization of Electric Vehicles for Vehicle-to-Grid Services: Progress and Perspectives
Authors: Ravi Sai Sudharshan , Aziz Muhammad
Published: January 2022

With every passing second, we witness the effect of the global environmental impact of fossil fuels and carbon emissions, to which nations across the globe respond by coming up with ambitious goals to become carbon-free and energy-efficient. At the same time, electric vehicles (EVs) are developed as a possible solution to reach this ambitious goal of making a cleaner environment and facilitating smarter transportation modes. This excellent idea of shifting towards an entirely EV-based mobility industry and economy results in a range of issues that need to be addressed. The issues range from ramping up the electricity generation for the projected increase in consumption to developing an infrastructure that is large enough to support the higher demand for electricity that arises due to the market penetration of EVs. Vehicle to grid (V2G) is a concept that is largely in a testing phase in the current scenario. However, it appears to offer a solution to the issues created by a mobility sector that the constantly growing EV fleet will dominate. Furthermore, the integration of EVs with the grid seems to offer various cost-wise and environment-wise benefits while assisting the grid by tapping into the idle energy of parked EVs during peak hours. This review aims to present some of the possible ancillary service potentials of such a system while also discussing the potential challenges, impacts, and future market penetration capabilities of V2G technology.
Determinants of Demand Response Program Participation: Contingent Valuation Evidence from a Smart Thermostat Program
Authors: Kaczmarski Jesse , Jones Benjamin , Chermak Janie
Published: January 2022

As renewable electricity generation continues to increase in the United States (US), considerable effort goes into matching heterogeneous supply to demand at a subhour time-step. As a result, some electric providers offer incentive-based programs for residential consumers that aim to reduce electric demand during high-demand periods. There is little research into determinants of consumer response to incentive-based programs beyond typical sociodemographic characteristics. To add to this body of literature, this paper presents the findings of a dichotomous choice contingent valuation (CV) survey targeting US ratepayers’ participation in a direct-load-control scheme utilizing a smart thermostat designed to reallocate consumer electricity demand on summer days when grid stress is high. Our results show approximately 50% of respondents are willing to participate at a median willingness-to-accept (WTA) figure of USD 9.50 (95% CI: 3.74, 15.25) per month that lasts for one summer (June through August)—or slightly less than USD 30 per annum. Participation is significantly affected by a respondent’s attitudes and preferences surrounding various environmental and institutional perspectives, but not by sociodemographic characteristics. These findings suggest utilities designing direct-load-control programs may improve participation by designing incentives specific to customers’ attitudes and preferences.
Using Machine Learning to Identify the Potential Marginal Land Suitable for Giant Silvergrass (Miscanthus × giganteus)
Authors: Hao Mengmeng , Chen Shuai , Qian Yushu , Jiang Dong , Ding Fangyu
Published: January 2022

Developing biomass energy, seen as the most important renewable energy, is becoming a prospective solution in attempting to deal with the world’s sustainability-related challenges, such as climate change, energy crisis, and carbon emission reduction. As one of the most promising second-generation energy crops, giant silvergrass (Miscanthus × giganteus) is highly valued for its high potential for biomass production and low maintenance requirements. Mapping the potential global distribution of marginal land suitable for giant silvergrass is an essential prerequisite for the development of giant silvergrass-based biomass energy. In this study, a boosting regression tree was used to identify the marginal land resources for giant silvergrass cultivation using influencing factors, which include climate conditions, soil conditions, topography conditions, and land use. The results indicate that there are 3068.25 million hectares of land resources worldwide suitable for giant silvergrass cultivation, which are mainly located in Africa (902.05 million hectares), Asia (620.32 million hectares), South America (547.60 million hectares), and North America (529.26 million hectares). Among them, countries with the most land resources, Russia and Brazil, have the first- and second-highest amounts of suitable marginal land for giant silvergrass, with areas of 373.35 and 332.37 million hectares, respectively. Our results also rank the involved factors by their contribution. Climatic conditions have the greatest influence on the spatial distribution of giant silvergrass, with an average contribution of 74.38%, followed by land use, with a contribution of 17.38%. The contribution of the soil conditions is 7.26%. The results of this study provide instructive support for future biomass energy policy development.
Communicating the Values and Benefits of Home Solar Prosumerism
Authors: Wuebben Daniel , Peters Jens
Published: January 2022

Clearly and accurately communicating the economic, environmental, and social benefits of solar PV prosumerism poses significant challenges. Previous research shows that government policies and public engagement campaigns can positively impact solar prosumerism; however, little is known about the quality and accuracy of information exchanged between rooftop solar installers and potential prosumers. This study addresses part of this gap with a mixed methods approach. First, a multimodal discourse analysis of installation proposals from seven home solar installers in Madrid shows accurate and reasonable financial benefits alongside incongruent social and environmental benefits. Second, the calculated efficiency of the seven proposed solar installations is compared with the efficiency of four different PVSC solar arrays using actual load and generation profiles. The results show that (i) the high variability of actual household demand on the minute-by- minute level significantly decreases self-consumption rate and profitability in comparison with the rates estimated using hourly or monthly, and (ii) the grouping of households into solar communities should significantly increase self-consumption and profitability. Therefore, using minute by minute time series in home solar estimations would reveal an added value and social benefit that is commonly overlooked. We conclude with recommendations for future research and multimodal communication campaigns that balance benefits of individual prosumerism and community solar.
Measurement of Infrasound Components Contained in the Noise Emitted during a Working Wind Turbine
Authors: Boczar Tomasz , Zmarzły Dariusz , Kozioł Michał , Nagi Łukasz , Wotzka Daria , Nadolny Zbigniew
Published: January 2022

The research reported in this paper involves the development and refinement of methods applicable to the measurement and analysis of infrasound signals generated by the operation of wind turbines. In particular, the presentation focuses on the use of a new system that is applied for simultaneous recording of acoustic signals in the low-frequency range emitted by wind farms in three independent and identical measurement setups. A comparative analysis of the proposed new system was made with the Brüel & Kjaer measurement, a commonly used methodology, which meets the requirements of the IEC 61400-11 standard. The paper focuses on the results of frequency and time-frequency analysis of infrasound signals recorded throughout the operation of a wind turbine with a rated capacity of 2 MW. The use of a correlated system with three simultaneous measurement systems can be a new and alternative measurement method that will eliminate the drawbacks of previous approaches.
Numerical and Experimental Study of a Novel Additively Manufactured Metal-Polymer Composite Heat-Exchanger for Liquid Cooling Electronics
Authors: Kailkhura Gargi , Mandel Raphael Kahat , Shooshtari Amir , Ohadi Michael
Published: January 2022

In order to meet increasing power-dissipation requirements of the electronics industry, compact, low-cost, and lightweight heat exchangers (HXs) are desired. With proper design, materials, and manufacture, polymer composite heat exchangers could meet these requirements. This paper presents a novel crossflow air-to-water, low-cost, and lightweight metal-polymer composite HX. This HX, which is entirely additively manufactured, utilizes a novel cross-media approach that provides direct heat exchange between air and liquid sides by using connecting fins. A robust numerical model was developed, which includes the dimensional effects of additive manufacturing. The study consists of a simplified 3D CFD model based on ellipsoidal-shaped staggered tube banks for the laminar range. It then uses an analytical approach to compute entire HX performance. The model is validated experimentally within 8% for thermal performance, 12% for air-side impedance, and 18% for water-side impedance. Finally, HX is compared with a conventional CPU radiator and performs within 10% of the conventional unit for reasonable flow rates and pressure-drop ranges. Moreover, HX also provides added design and cost advantages over the conventional unit, which makes the HX a potential candidate for electronic cooling applications.
Enantiomers and Their Resolution
Authors: Santos Rodrigo , Pontes Karen V. , Nogueira Idelfonso B. R.
Published: January 2022

Enantiomers share the same chemical formula but have different chemical structures, i.e., type of isomers. Enantiomers are present in several drugs, perfumes, food, and are a fundamental part of biomolecules. This subject is highly important for pharmaceutical companies. Enantiomeric drugs present different actuation in the human body; depending on the compound, one might combat the symptom, whereas its pair might cause damage. The separation of pairs of enantiomers requires a chiral environment that provokes a structural imbalance that conventional methods cannot provide. Enantioresolution is one of the most promissory studies that benefit several areas, such as pharmaceutical, biotechnology, food industry, and fine chemistry. Its resolution is of great importance, therefore, its main mechanisms of resolution will be explained herein.
Soil Compaction after Increasing the Number of Wheeled Tractors Passes on Forest Soils in West Carpathians
Authors: Allman Michal , Dudáková Zuzana , Jankovský Martin , Vlčková Mária , Juško Vladimír , Tomčík Daniel
Published: January 2022

Soil disturbance and compaction are inherent in ground-based harvesting operations. These changes are affected by numerous factors, related mainly to the technical parameters of the machines, soil conditions, and the technology used. This study aimed to analyze the changes of surface layers of soil caused by skidder traffic without loads on the Cambisols of Western Carpathians. We observed changes in the soil bulk density and penetration resistance. The results showed that only machine traffic caused a 0.32 to 0.35 (g cm−3) increase in soil bulk density. Besides machine traffic, bulk density was affected by soil moisture content. Penetration resistance of soil increased by 0.15 to 1.04 (MPa) after traffic of 40 machines. Penetration resistance showed a lower increase after traffic, and regression and correlation analysis proved a relationship between penetration resistance, skeleton content, and penetration depth, besides the number of machine passes (r = 0.33–0.55). Observing the changes in the physical properties of soils caused by machine traffic allows for a more detailed view of the effects of forest harvesting machinery on forest soils.
Effects of Dietary Enterococcus faecalis YFI-G720 on the Growth, Immunity, Serum Biochemical, Intestinal Morphology, Intestinal Microbiota, and Disease Resistance of Crucian Carp (Carassius auratus)
Authors: Xu Yan , Li Yiqun , Xue Mingyang , Xiao Zidong , Fan Yuding , Zeng Lingbing , Zhou Yong
Published: January 2022

Diseases of crucian carp (Carassius auratus) are closely related to intestinal parameters. Enterococcus faecalis has strong colonization ability in the intestinal tract, and produces natural antibiotics, bacteriocin, and other bacteriostatic substances, which can effectively inhibit some pathogenic bacteria and improve the intestinal microenvironment. This study aimed to assess the effects of E. faecalis YFI-G720 which was isolated from the intestinal of crucian carp on the growth, immunity, intestinal health, and disease resistance of crucian carp. Fish (48.16 ± 0.55 g) were fed four diets, commercial diet or diet containing E. faecalis at 105 CFU/g (EF1), 106 CFU/g (EF2), or 107 CFU/g (EF3) for 28 days. The results showed that supplementation of E. faecalis significantly improved the weight gain ratio (WGR) and the specific growth rate (SGR) compared with control group (p < 0.05). Intestinal mucosal epithelial cells in EF2 were intact and normal, but there was obvious vacuolation in CG. Compared with CG, serum C3 and IgM in EF2 were significantly increased at the end of the experiment (p < 0.05), and serum alkaline phosphatase was significantly higher in all experimental groups (p < 0.05). Among studied immune-related genes, expression was detected by qPCR, C3, IgM, and IL-1βwere upregulated in all experimental groups to varying degrees from 14 days, with highest expression in EF2 at 28 days. Intestinal microbiota structure analyzed through high-throughput sequencing, and the results showed that the relative abundance of Aeromonas and Acinetobacter decreased while Cetobacterium increased in all experimental groups, with the greatest changes in EF2. Challenge tests showed that fish fed E. faecalis were more resistant to Aeromonas veronii (p < 0.05). In conclusion, dietary E. faecalis YFI-G720 at 106 CFU/g can improve the health status, immune parameters, intestinal microbiota composition, and disease resistance of crucian carp.
A Multidisciplinary Approach Evaluating Soybean Meal-Induced Enteritis in Rainbow Trout Oncorhynchus mykiss
Authors: Seibel Henrike , Chikwati Elvis , Schulz Carsten , Rebl Alexander
Published: January 2022

This study evaluated a diverse range of markers of feeding stress to obtain a more precise assessment of the welfare of rainbow trout in relation to inadequate husbandry conditions. A feeding stress model based on dietary soybean meal was employed to identify suitable minimally invasive “classical” stress markers, together with molecular signatures. In a 56-day feeding experiment, rainbow trout were fed diets containing different levels of soybean meal. The impact of these different soybean meal diets on rainbow trout was assessed by water quality analyses, clinical health observations, classic growth and performance parameters, gut histopathology, blood-parameter measurements and multigene-expression profiling in RNA from whole blood. Soybean meal-induced enteritis was manifested phenotypically by an inflammatory reaction in the posterior section of the intestine and by diarrhoea in some trout. These inflammatory changes were associated with decreased supranuclear vacuolation. The haematocrit values and the levels of plasma cortisol and circulating lymphocytes in the blood were increased in trout that had consumed high amounts of SBM. Notably, the increased haematocrit depended significantly on the bodyweight of the individual trout. The transcript levels of certain genes (e.g., MAP3K1, LYG, NOD1, STAT1 and HSP90AB) emerged as potentially useful indicators in the blood of rainbow trout providing valuable information about inadequate nutrition. The expression-profiling findings provide a basis for improved, minimally invasive monitoring of feeding regimens in trout farming and may stimulate the development of practical detection devices for innovative aquaculture operations.
Instability and Transition of a Boundary Layer over a Backward-Facing Step
Authors: Teng Ming , Piomelli Ugo
Published: January 2022

The development of secondary instabilities in a boundary layer over a backward-facing step is investigated numerically. Two step heights are considered, h/δo*=0.5 and 1.0 (where δo* is the displacement thickness at the step location), in addition to a reference flat-plate case. A case with a realistic freestream-velocity distribution is also examined. A controlled K-type transition is initiated using a narrow ribbon upstream of the step, which generates small and monochromatic perturbations by periodic blowing and suction. A well-resolved direct numerical simulation is performed. The step height and the imposed freestream-velocity distribution exert a significant influence on the transition process. The results for the h/δo*=1.0 case exhibit a rapid transition primarily due to the Kelvin–Helmholtz instability downstream of step; non-linear interactions already occur within the recirculation region, and the initial symmetry and periodicity of the flow are lost by the middle stage of transition. In contrast, case h/δo*=0.5 presents a transition road map in which transition occurs far downstream of the step, and the flow remains spatially symmetric and temporally periodic until the late stage of transition. A realistic freestream-velocity distribution (which induces an adverse pressure gradient) advances the onset of transition to turbulence, but does not fundamentally modify the flow features observed in the zero-pressure gradient case. Considering the budgets of the perturbation kinetic energy, both the step and the induced pressure-gradient increase, rather than modify, the energy transfer.
Environmental Impact of Meals: How Big Is the Carbon Footprint in the School Canteens?
Authors: Volanti Mirco , Arfelli Francesco , Neri Esmeralda , Saliani Aurora , Passarini Fabrizio , Vassura Ivano , Cristallo Gianluca
Published: January 2022

The inhabitants of the world are expected to grow by two billion in the next two decades; as population increases, food demand rises too, leading to more intensive resource exploitation and greater negative externalities related to food production. In this paper the environmental impact of meals provided in school canteens are analysed through the Life Cycle Assessment methodology, in order to evaluate the GHGs emissions released by food production. Meals, and not just individual foods, have been considered so as to include in the analysis the nutritional aspects on which meals are based. Results shows that meat, fish and dairy products are the most impacting in terms of greenhouse gas emissions, with values that shift from 31.7 and 24.1 kg CO2 eq for butter and veal, to 2.37 kg CO2 eq for the octopus, while vegetables, legumes, fruit and cereals are less carbon intensive (average of 3.71 kg CO2 eq for the considered vegetables). When the environmental impact is related to the food energy, the best option are first courses because they combine a low carbon footprint with a high energy content. The results of the work can be used both by the consumer, who can base the meal choice on environmental impact information, and by food services, who can adjust menus to achieve a more sustainable production.
Identifying Consumer Groups and Their Characteristics Based on Their Willingness to Engage with Cultured Meat: A Comparison of Four European Countries
Authors: Boereboom Anouk , Mongondry Philippe , de Aguiar Luis K. , Urbano Beatriz , Jiang Zheng (Virgil) , de Koning Wim , Vriesekoop Frank
Published: January 2022

Cultured meat, as a product of recent advancement in food technology, might become a viable alternative source of protein to traditional meat. As such, cultured meat production is disruptive as it has the potential to change the demand for traditional meats. Moreover, it has been claimed it can be more sustainable regarding the environment and that it is, perhaps, a solution to animal welfare issues. This study aimed at investigating associations between the consumer groups and demographic and psychographic factors as well as identifying distinct consumer groups based on their current willingness to engage with cultured meat. Four European countries were studied: the Netherlands (NL), the United Kingdom (UK), France (FR) and Spain (ES). A sample of 1291 responses from all four countries was collected between February 2017 and March 2019. Cluster analysis was used, resulting in three groups in the NL and UK, and two groups in FR and ES. The results suggest that Dutch consumers are the most willing to engage with cultured meat. Food neophobia and food technology neophobia seem to distinguish the groups the clearest. Moreover, there is some evidence that food cultural differences among the four countries seem to be also influencing consumers’ decision.
Soil Colour and Plant-Wax Markers: Application in Forensic Investigations under Urban Subtropical Environments
Authors: Testoni Samara , Dawson Lorna , Melo Vander , Lopes-Mazzetto Josiane , Ramalho Bruna , Salvador Fábio
Published: January 2022

Most cases involving soil in criminal investigations in Brazil have focused on the chemical and mineralogical analyses of soil fractions without including the organic matter. The organic fraction contains plant-wax markers which may be useful to “fingerprint” forensic soils due to their chemical diversity, relative longevity and resistant nature. The aim of this study was to test the long- (kilometre), medium- (metre) and short- (centimetre) scale variability of plant-wax biomarkers in a forensic context in anthropised urban soils and soils developed under subtropical conditions. Two areas from the Curitiba municipality and two areas from the Colombo municipality, Paraná State, South Brazil, were selected. Soil colour analysis was carried out to obtain reflectance data over the 360–740 nm wavelength range. Furthermore, plant-wax marker compounds (n-alkanes and fatty-alcohols) were assessed by extraction and separation into different classes and an analysis of the compounds by gas chromatography (GC/MS). The compositions of the wax-marker profiles were different in samples collected side-by-side, showing sensitivity to local variations under subtropical conditions and in areas under intense human urban disturbance. Under these conditions, biomarkers may be used in real crime scenes, even on a micrometric scale of variation.
A Langevin-Type q-Variant System of Nonlinear Fractional Integro-Difference Equations with Nonlocal Boundary Conditions
Authors: Agarwal Ravi P. , Al-Hutami Hana , Ahmad Bashir
Published: January 2022

We introduce a new class of boundary value problems consisting of a q-variant system of Langevin-type nonlinear coupled fractional integro-difference equations and nonlocal multipoint boundary conditions. We make use of standard fixed-point theorems to derive the existence and uniqueness results for the given problem. Illustrative examples for the obtained results are also presented.
Zinc- and Copper-Loaded Nanosponges from Cellulose Nanofibers Hydrogels: New Heterogeneous Catalysts for the Synthesis of Aromatic Acetals
Authors: Riva Laura , Lotito Angelo Davide , Punta Carlo , Sacchetti Alessandro
Published: January 2022

Herein we report the synthesis of cellulose-based metal-loaded nano-sponges and their application as heterogeneous catalysts in organic synthesis. First, the combination in water solution of TEMPO-oxidized cellulose nanofibers (TOCNF) with branched polyethyleneimine (bPEI) and citric acid (CA), and the thermal treatment of the resulting hydrogel, leads to the synthesis of an eco-safe micro- and nano-porous cellulose nano-sponge (CNS). Subsequently, by exploiting the metal chelation characteristics of CNS, already extensively investigated in the field of environmental decontamination, this material is successfully loaded with Cu (II) or Zn (II) metal ions. Efficiency and homogeneity of metal-loading is confirmed by scanning electron microscopy (SEM) analysis with an energy dispersive X-ray spectroscopy (EDS) detector and by inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis. The resulting materials perform superbly as heterogeneous catalysts for promoting the reaction between aromatic aldehydes and alcohols in the synthesis of aromatic acetals, which play a fundamental role as intermediates in organic synthesis. Optimized conditions allow one to obtain conversions higher than 90% and almost complete selectivity toward acetal products, minimizing, and in some cases eliminating, the formation of carboxylic acid by-products. ICP-OES analysis of the reaction medium allows one to exclude any possible metal-ion release, confirming that catalysis undergoes under heterogeneous conditions. The new metal-loaded CNS can be re-used and recycled five times without losing their catalytic activity.
Wnt Pathway Extracellular Components and Their Essential Roles in Bone Homeostasis
Authors: Martínez-Gil Núria , Ugartondo Nerea , Grinberg Daniel , Balcells Susanna
Published: January 2022

The Wnt pathway is involved in several processes essential for bone development and homeostasis. For proper functioning, the Wnt pathway is tightly regulated by numerous extracellular elements that act by both activating and inhibiting the pathway at different moments. This review aims to describe, summarize and update the findings regarding the extracellular modulators of the Wnt pathway, including co-receptors, ligands and inhibitors, in relation to bone homeostasis, with an emphasis on the animal models generated, the diseases associated with each gene and the bone processes in which each member is involved. The precise knowledge of all these elements will help us to identify possible targets that can be used as a therapeutic target for the treatment of bone diseases such as osteoporosis.
Effects of BPA, BPS, and BPF on Oxidative Stress and Antioxidant Enzyme Expression in Bovine Oocytes and Spermatozoa
Authors: Nguyen Mimi , Sabry Reem , Davis Ola S. , Favetta Laura A.
Published: January 2022

Bisphenol A (BPA) and its analogs, bisphenol S (BPS) and bisphenol F (BPF), might impact fertility by altering oxidative stress pathways. Here, we hypothesize that bisphenols-induced oxidative stress is responsible for decreased gamete quality. In both female (cumulus-oocyte-complexes—COCs) and male (spermatozoa), oxidative stress was measured by CM-H2DCFDA assay and key ROS scavengers (SOD1, SOD2, GPX1, GPX4, CAT) were quantified at the mRNA and protein levels using qPCR and Western blot (COCs)/immunofluorescence (sperm). Either gamete was treated in five groups: control, vehicle, and 0.05 mg/mL of BPA, BPS, or BPF. Our results show elevated ROS in BPA-treated COCs but decreased production in BPS- and BPF-treated spermatozoa. Additionally, both mRNA and protein expression of SOD2, GPX1, and GPX4 were decreased in BPA-treated COCs (p < 0.05). In sperm, motility (p < 0.03), but not morphology, was significantly altered by bisphenols. SOD1 mRNA expression was significantly increased, while GPX4 was significantly reduced. These results support BPA’s ability to alter oxidative stress in oocytes and, to a lesser extent, in sperm. However, BPS and BPF likely act through different mechanisms.
Effect of Geometric Parameters and Construction Sequence on Ground Settlement of Offset Arrangement Twin Tunnels
Authors: Islam Md Shariful , Iskander Magued
Published: January 2022

A parametric study that examines the ground surface settlement due to the excavation of shallow offset arrangement twin tunnels is presented. Offset arrangement tunnels are those that run parallel to each other, but at different elevations. The study focuses on the influence of both the construction sequence and various geometric parameters on the induced soil settlement. A series of three-dimensional finite element analyses was carried out to investigate the settlement behavior and interactions between offset arrangement twin tunnels excavated in clay using a simplified mechanized excavation method. Analyses were carried out for three cover-to-diameter (C/D) ratios, three possible construction sequences, five angular relative positions, and five angular spacings. In addition, settlement data were also investigated by varying horizontal and vertical spacings while keeping the angular spacing constant. The total settlement of the excavated twin tunnels and the settlement induced solely by the new second tunnel are both presented, and special attention was paid to identifying the dominant geometric parameters. The observed data trends from this study are generally consistent with the limited data available in the literature. This study confirmed a few perceived behaviors. First, angular relative position better describes the settlement behavior in comparison to angular spacing. Second, the effect of the vertical distance is noticeably more significant than that of the horizontal distance between the two tunnels. Third, excavation of the lower tunnel at first induces higher total ground settlement than when the upper tunnel is excavated first or when both tunnels are excavated concurrently. Fourth, settlement due to the construction of the newer tunnel decreases with the increase in the cover depth. In addition, two design charts have been proposed to calculate the settlement induced from a new second tunnel excavation and the eccentricity of the maximum total settlement relative to the center of the new tunnel.
Happy Existentialist Metaphors: Merleau-Ponty’s Flesh of the World and the Chandos Complex
Authors: Dufourcq Annabelle
Published: January 2022

This article investigates the meaning of Merleau-Ponty’s concept of the flesh of the world. This concept brings a cosmological tone to existentialist phenomenology and challenges the grim and gnostic approach that prevails in Heidegger’s and Sartre’s works in particular. Is horror the key mood in ontology as argued by Malabou? This article contends that bright metaphors and magic realism are at least as fundamental, but under one condition: ontology must come to terms with what the author has coined as the “Chandos complex”, namely a form of ambivalence and oscillation between Gnosticism and holism that makes both positions fake and hollow. Dreaming of being one with the world and fantasizing an estrangement from nature work hand in hand and are equally staged. Merleau-Ponty’s philosophy occasionally falls prey to the Chandos complex, which makes his concept of the flesh of the world vulnerable to criticism. This article examines the claim put forward by Renaud Barbaras that “the flesh of the world” is a failed metaphor. It argues that this blissful metaphor is ontologically fundamental as soon as its intrinsic paradoxes are recognized and accepted: the Chandos complex then becomes the key to an ontology that recognizes the imaginary as an essential dimension of being. At stake is an essential link between ontology on the one hand and, on the other hand, metaphors as well as myth-building and narrative-building processes.