bluuebunny/crossref_metadata_2025 huggingface dataset:
Habitat Partitioning and Overlap by Large Lacertid Lizards in Southern Europe
Authors: Escoriza Daniel , Amat Félix
Published: April 2021

South-western Europe has a rich diversity of lacertid lizards. In this study, we evaluated the occupancy patterns and niche segregation of five species of lacertids, focusing on large-bodied species (i.e., adults having >75 mm snout-vent length) that occur in south-western Europe (Italian to the Iberian Peninsula). We characterized the niches occupied by these species based on climate and vegetation cover properties. We expected some commonality among phylogenetically related species, but also patterns of habitat segregation mitigating competition between ecologically equivalent species. We used multivariate ordination and probabilistic methods to describe the occupancy patterns and evaluated niche evolution through phylogenetic analyses. Our results showed climate niche partitioning, but with a wide overlap in transitional zones, where segregation is maintained by species-specific responses to the vegetation cover. The analyses also showed that phylogenetically related species tend to share large parts of their habitat niches. The occurrence of independent evolutionary lineages contributed to the regional species richness favored by a long history of niche divergence.
The Prognostic Impact of HER2 Genetic and Protein Expression in Pancreatic Carcinoma—HER2 Protein and Gene in Pancreatic Cancer
Authors: Han Song-Hee , Ryu Ki Hyun , Kwon Ah-Young
Published: April 2021

Pancreatic ductal adenocarcinoma (PDAC) is a lethal and clinically heterogeneous disease with a limited benefit from human epidermal growth factor receptor 2 (HER2)-targeted therapy. Recently, some studies have addressed the antitumoral effect of novel anti-HER2 drugs in HER2 low-expressing tumors. However, there have been few studies on the significance of low HER2 expression and genetic heterogeneity in PDAC. Using immunohistochemistry and dual-color silver-enhanced in situ hybridization based on the Trastuzumab for a gastric cancer scoring scheme, we evaluated HER2 protein expression, gene amplification, and genetic heterogeneity in three groups (HER2-neg, HER2-low, HER2-pos) of 55 patients. Among the 55 cases, 41.8% (23/55) showed HER2 expression of any intensity. HER2 amplification independent of HER2 expression was 25.5% (14/55). Patients in both these groups had a shorter overall survival than did patients in the HER2-neg group. HER2 genetic heterogeneity was identified in 37 (70.9%) of the 55 cases, mainly in HER2-neg and HER2-low groups. HER2 genetic heterogeneity significantly correlated with worse survival in the HER2-low and HER2-neg groups of PDAC. These findings support the hypothesis that low-level HER2 expression and heterogeneity have significant clinical implications in PDAC. HER2 heterogeneity might indicate the best strategies of combination therapies to prevent the development of subdominant clones with resistance potential.
Percutaneous Microwave Ablation of Liver Lesions: Differences on the Sphericity Index of the Ablation Zone between Cirrhotic and Healthy Liver Parenchyma
Authors: Tsochatzis Athanasios , Mazioti Argyro , Iliadis Georgios , Velonakis Georgios , Efthymiou Evgenia , Kelekis Alexis , Kelekis Nikolaos , Filippiadis Dimitrios
Published: April 2021

To compare different parameters of the sphericity index of the ablation zone following microwave ablation (MWA) on cirrhotic- and healthy-liver parenchyma in a series of patients treated with the same MWA system. Institutional database research identified 46 patients (77 lesions) who underwent MWA. “Cirrhotic liver group” (CLG) included 35 hepatocellular carcinoma lesions; “healthy liver group” (HLG) included 42 metastatic lesions. The long axis (LAD), short axis 1 (SAD-1) and 2 (SAD-2), the mean SAD-1 and SAD-2 (mSAD) diameter (in mm) and the mean sphericity (mSPH) index of the ablation zones were evaluated for each treated lesion in both groups from baseline to follow-up. A mixed model analysis of variance reported significant main effect of group on SAD-1 (p = 0.023), SAD-2 (p = 0.010) and mSAD (p = 0.010), with HLG showing lower values compared to CLG. No differences were detected on the LAD (pFDR = 0.089; d = 0.45), and mSPH (pFDR = 0.148, d = 0.40) between the two groups. However, a significant main effect of time was found on LAD (p < 0.001), SAD-1 (p < 0.001), SAD-2 (p < 0.001) and mSAD (p < 0.001), with decreased values in all indices at follow-up compared to baseline. A significant group by time interaction was observed on mSPH (p = 0.044); HLG had significantly lower mSPH at follow-up where CLG did not show any significant change. Our findings indicate that although in cirrhotic liver short axis diameter of the MWA zone seems to be significantly longer, this has no effect on the sphericity index which showed no significant difference between cirrhotic vs. healthy liver lesions. On the contrary, on one month follow-up ablation zones tend to become significant more ellipsoid in healthy whilst remains stable in cirrhotic liver.
Effects of Transcranial Direct Current Stimulation Combined with Physiotherapy on Gait Pattern, Balance, and Functionality in Stroke Patients. A Systematic Review
Authors: Navarro-López Víctor , Molina-Rueda Francisco , Jiménez-Jiménez Samuel , Alguacil-Diego Isabel M , Carratalá-Tejada María
Published: April 2021

Background: The effectiveness of transcranial direct current stimulation (tDCS) together with conventional physiotherapy in motor rehabilitation after stroke has been widely studied. Despite this, few studies have focused on its application in gait and balance rehabilitation. This review aimed to determine the efficacy of transcranial direct current stimulation combined with conventional physiotherapy on gait, balance, and the functionality of the lower limb after stroke. Methods: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Four electronic databases were systematically searched for relevant articles. Randomized clinical trials in English or Spanish that evaluated the use of the transcranial direct current stimulation, combined with physiotherapy, to improve gait, balance, and lower limb functionality after stroke were included. Main results: 10 articles were included, with a total of 222 subjects. Data about population, assessment tools, protocols, sessions, and results were extracted. The methodological quality of the included studies ranged between 3 and 5. Conclusion: The use of transcranial direct current stimulation combined with physiotherapy improves gait parameters, static and dynamic balance, and lower limb functionality in stroke patients. Long-term effects have not yet been demonstrated.
Brain Dynamics Altered by Photic Stimulation in Patients with Alzheimer’s Disease and Mild Cognitive Impairment
Authors: Yu Wei-Yang , Low Intan , Chen Chien , Fuh Jong-Ling , Chen Li-Fen
Published: April 2021

Individuals with mild cognitive impairment (MCI) are at high risk of developing Alzheimer’s disease (AD). Repetitive photic stimulation (PS) is commonly used in routine electroencephalogram (EEG) examinations for rapid assessment of perceptual functioning. This study aimed to evaluate neural oscillatory responses and nonlinear brain dynamics under the effects of PS in patients with mild AD, moderate AD, severe AD, and MCI, as well as healthy elderly controls (HC). EEG power ratios during PS were estimated as an index of oscillatory responses. Multiscale sample entropy (MSE) was estimated as an index of brain dynamics before, during, and after PS. During PS, EEG harmonic responses were lower and MSE values were higher in the AD subgroups than in HC and MCI groups. PS-induced changes in EEG complexity were less pronounced in the AD subgroups than in HC and MCI groups. Brain dynamics revealed a “transitional change” between MCI and Mild AD. Our findings suggest a deficiency in brain adaptability in AD patients, which hinders their ability to adapt to repetitive perceptual stimulation. This study highlights the importance of combining spectral and nonlinear dynamical analysis when seeking to unravel perceptual functioning and brain adaptability in the various stages of neurodegenerative diseases.
Inclusive Education in Portugal: Teachers’ Professional Development, Working Conditions, and Instructional Efficacy
Authors: Lopes João Lamego , Oliveira Célia Regina
Published: April 2021

Inclusive education policies thin the boundaries of special and regular education as well as teachers’ roles and competencies. The present study, using data from TALIS 2018, aims to find out whether Portuguese teachers working in classes directed entirely or mainly to special education needs students (SENS) differ from teachers working in classes with few or no SENS in the following areas: (a) professional development needs in special education; (b) perceived barriers to professional development; and (c) teaching and work features related to SENS. The results show small but significant differences between teachers working and teachers not working entirely or mainly with SENS in professional development needs, perceived opportunities for professional development, and stress involved in modifying SENS lessons. No other significant differences were found. Still, the results show that both groups of teachers perceive significant professional development needs and barriers to professional development but are optimistic about the quality of professional development, job satisfaction, and self-efficacy in instruction. However, teachers of both groups are pessimistic about professional collaboration, a key element of inclusive education. Overall, it seems that some critical elements of inclusive education are still to be implemented in Portuguese schools.
A 6-Locking Cycles All-Digital Duty Cycle Corrector with Synchronous Input Clock
Authors: Kao Shao-Ku
Published: April 2021

This paper proposes an all-digital duty cycle corrector with synchronous fast locking, and adopts a new quantization method to effectively produce a phase of 180 degrees or half delay of the input clock. By taking two adjacent rising edges input to two delay lines, the total delay time of the delay line is twice the other delay line. This circuit uses a 0.18 μm CMOS process, and the overall chip area is 0.0613 mm2, while the input clock frequency is 500 MHz to 1000 MHz, and the acceptable input clock duty cycle range is 20% to 80%. Measurement results show that the output clock duty cycle is 50% ± 2.5% at a supply voltage of 1.8 V operating at 1000 MHz, the power consumed is 10.1 mW, with peak-to-peak jitter of 9.89 ps.
VLSI Implementation of a Cost-Efficient Loeffler DCT Algorithm with Recursive CORDIC for DCT-Based Encoder
Authors: Chung Rih-Lung , Chen Chen-Wei , Chen Chiung-An , Abu Patricia Angela R. , Chen Shih-Lun
Published: April 2021

This paper presents a low-cost and high-quality, hardware-oriented, two-dimensional discrete cosine transform (2-D DCT) signal analyzer for image and video encoders. In order to reduce memory requirement and improve image quality, a novel Loeffler DCT based on a coordinate rotation digital computer (CORDIC) technique is proposed. In addition, the proposed algorithm is realized by a recursive CORDIC architecture instead of an unfolded CORDIC architecture with approximated scale factors. In the proposed design, a fully pipelined architecture is developed to efficiently increase operating frequency and throughput, and scale factors are implemented by using four hardware-sharing machines for complexity reduction. Thus, the computational complexity can be decreased significantly with only 0.01 dB loss deviated from the optimal image quality of the Loeffler DCT. Experimental results show that the proposed 2-D DCT spectral analyzer not only achieved a superior average peak signal–noise ratio (PSNR) compared to the previous CORDIC-DCT algorithms but also designed cost-efficient architecture for very large scale integration (VLSI) implementation. The proposed design was realized using a UMC 0.18-μm CMOS process with a synthesized gate count of 8.04 k and core area of 75,100 μm2. Its operating frequency was 100 MHz and power consumption was 4.17 mW. Moreover, this work had at least a 64.1% gate count reduction and saved at least 22.5% in power consumption compared to previous designs.
European Union Green Deal and the Opportunity Cost of Wastewater Treatment Projects
Authors: Vindel Jose M. , Trincado Estrella , Sánchez-Bayón Antonio
Published: April 2021

The European Union Green Deal aims at curbing greenhouse gas emissions and introducing clean energy production. But to achieve energy efficiency, the opportunity cost of different energies must be assessed. In this article, two different energy self-sufficient systems for wastewater treatment are compared. On the one hand, high-rate algal ponds system (HRAP) is considered; on the other hand, a conventional activated sludge system (AS) which uses photovoltaic power (PV) is studied. The paper offers a viability analysis of both systems based on the capacity to satisfy their energetic consumption. This viability analysis, along with the opportunity cost study, will be used in the article to compare these two projects devoted to the treatment of wastewater. In order to assess viability, the probability of not achieving the energy consumption threshold at least one day is studied. The results point that the AS+PV system self-sufficiency is achieved with much lesser land requirements than the HRAP system (for the former, less than 6500 m2, for the latter 40,000 m2). However, the important AS capital cost makes still the HRAP system more economic, although storage provides a great advantage for using the AS+PV in locations where a lot of irradiance is available.
Concrete Support Structures for Offshore Wind Turbines: Current Status, Challenges, and Future Trends
Authors: Mathern Alexandre , von der Haar Christoph , Marx Steffen
Published: April 2021

Today’s offshore wind turbine support structures market is largely dominated by steel structures, since steel monopiles account for the vast majority of installations in the last decade and new types of multi-leg steel structures have been developed in recent years. However, as wind turbines become bigger, and potential sites for offshore wind farms are located in ever deeper waters and ever further from the shore, the conditions for the design, transport, and installation of support structures are changing. In light of these facts, this paper identifies and categorizes the challenges and future trends related to the use of concrete for support structures of future offshore wind projects. To do so, recent advances and technologies still under development for both bottom-fixed and floating concrete support structures have been reviewed. It was found that these new developments meet the challenges associated with the use of concrete support structures, as they will allow the production costs to be lowered and transport and installation to be facilitated. New technologies for concrete support structures used at medium and great water depths are also being developed and are expected to become more common in future offshore wind installations. Therefore, the new developments identified in this paper show the likelihood of an increase in the use of concrete support structures in future offshore wind farms. These developments also indicate that the complexity of future support structures will increase due to the development of hybrid structures combining steel and concrete. These evolutions call for new knowledge and technical know-how in order to allow reliable structures to be built and risk-free offshore installation to be executed.
Conditions Driving Low-Carbon Innovation in a Medium-Sized European Country That Is Catching Up–Case Study of Poland
Authors: Świadek Arkadiusz , Gorączkowska Jadwiga , Godzisz Karolina
Published: April 2021

Studies on the determinants of low-carbon innovations in developed countries already exist. We test here the institutional environment in Poland (science–government–enterprise) as supporters of the technological change in industry towards a low-carbon economy. We will examine as well whether conclusions for well-developed countries are relevant for those catching up. The aim of the article is to assess the systemic nature and durability of the impact of internal and external conditions on the implementation of low-carbon technologies in Polish industry. In order to achieve the goal, two surveys were carried out for the periods 2007–2012 and 2013–2018, on sample sizes of 11,493 enterprises. To verify the hypotheses, a statistical multi–factor logit modelling was used to determine the chances of low-carbon innovations under the influence of various parallel circumstances. The results of this research point to other, often abrupt (unstable) phenomena occurring in the catching-up economy, which are the consequence of a long-term technological gap. The case of Poland shows the lack of cooperation between science, enterprises and the government in stimulating the development of low-carbon technologies, although enterprises do try to implement such technologies on their own in the absence of any external cooperation. Without Research and Development (R&D) support and government subsidies, the attempt to implement low-carbon technology fails. Thus, the institutional framework should distinguish between catching-up and developed countries due to the gaps in technological knowledge, cooperation and institutional barriers.
Modeling Near-Miscible Gas Foam Injection in Fractured Tight Rocks and Its Challenges
Authors: Luo Haishan , Mohanty Kishore K.
Published: April 2021

Unlocking oil from tight reservoirs remains a challenging task, as the existence of fractures and oil-wet rock surfaces tends to make the recovery uneconomic. Injecting a gas in the form of a foam is considered a feasible technique in such reservoirs for providing conformance control and reducing gas-oil interfacial tension (IFT) that allows the injected fluids to enter the rock matrix. This paper presents a modeling strategy that aims to understand the behavior of near-miscible foam injection and to find the optimal strategy to oil recovery depending on the reservoir pressure and gas availability. Corefloods with foam injection following gas injection into a fractured rock were simulated and history matched using a compositional commercial simulator. The simulation results agreed with the experimental data with respect to both oil recovery and pressure gradient during both injection schedules. Additional simulations were carried out by increasing the foam strength and changing the injected gas composition. It was found that increasing foam strength or the proportion of ethane could boost oil production rate significantly. When injected gas gets miscible or near miscible, the foam model would face serious challenges, as gas and oil phases could not be distinguished by the simulator, while they have essentially different effects on the presence and strength of foam in terms of modeling. We provide in-depth thoughts and discussions on potential ways to improve current foam models to account for miscible and near-miscible conditions.
Tourism in the Era of Covid-19 and Its Impact on the Environment
Authors: Nagaj Rafał , Žuromskaitė Brigita
Published: April 2021

The Covid-19 pandemic has affected all areas of socio-economic life around the world. Its impact concerns not only the health system and the health of the population, but also the economy. Tourism is one of the sectors hardest hit by the restrictions imposed by governments in the wake of the pandemic. The pandemic has resulted in restrictions and limitations on movement and travel, covering both domestic and international tourism, which raises the question of have these restrictions imposed on tourist activities also caused an environmental impact? The aim of this article is to examine what impact the COVID-19 pandemic has had on the environmental issues within the tourism sector in the Central and Eastern European (CEE) region. The research task is to investigate whether this impact has changed in the pandemic era compared to previous years, and whether it has been positive or negative. The research method is multiple regression analysis. The results of the study indicated that the COVID-19 pandemic caused a decrease in greenhouse gas emissions from tourism in all CEE countries. Such decreases are both relative to 2019 and the estimated level of emissions that would be achieved if the countries surveyed achieved economic growth in 2020 consistent with the European Commission’s projections for that year. The scale of the impact varies from country to country, while the relationship between tourism development and pollution levels is positive.
Spectrum Analysis for Condition Monitoring and Fault Diagnosis of Ventilation Motor: A Case Study
Authors: Shabbir Noman , Kütt Lauri , Asad Bilal , Jawad Muhammad , Iqbal Muhammad Naveed , Daniel Kamran
Published: April 2021

In modern power systems, since most loads are inductive by nature, there is an ongoing power quality issue and researchers’ interest in improving the power factor is widespread, as inductive loads have a low power factor that depletes the system’s capacity and has an adverse effect on the voltage level. The measurement and acute analysis of voltage- and current-level waveforms is essential to tackle power quality issues. This article presents a detailed case study and analysis of real-time data measured from a frequency converter, which is used to operate the motor of a ventilation system. The output of the frequency converter is a highly distorted current wave. A hybrid Fourier transform (FT)- and wavelet transform-based solution has been proposed here to diagnose and identify the causes of motor failure in the ventilation system. The traditional FT did not give a detailed analysis of this type of signal, which is highly contaminated by noise. Therefore, first, the signal is preprocessed for data denoising using the wavelet transform. Second, the Fourier analysis is performed on the filtered signal for frequency analysis and segregation of fundamental frequency components, higher-order harmonics, and suppressed noise. The spectrum analysis reveals that the noise is generated due to the rapidly switching circuits in the frequency converter and this unfiltered signal at the output of the frequency converter causes motor failure.
Influence of Thermal Aging on the Combustion Characteristics of Cables in Nuclear Power Plants
Authors: Kim Min Ho , Seo Hyun Jeong , Lee Sang Kyu , Lee Min Chul
Published: April 2021

In this study, the combustion characteristics and emission of toxic gases of a non-class 1E cable in a nuclear power plant were investigated with respect to the aging period. A thermal accelerated aging method was applied using the Arrhenius equation with the activation energy of the cables and the aging periods of the cables set to zero, 10, 20, 30 and 40 years old by considering the lifetime of a nuclear power plant. According to ISO 5660-1 and ISO 19702, the cone calorimeter Fourier transform infrared spectroscopy test was performed to analyze the combustion characteristics and emission toxicity. In addition, scanning electron microscopy and an energy dispersive X-ray spectrometer were used to examine the change in the surface of the sheath and insulation of the cables according to the aging periods. To compare quantitative fire risks at an early period, the fire performance index (FPI) and fire growth index (FGI) are derived from the test results of the ignition time, peak heat release rate (PHRR) and time to PHRR (tPHRR). When comparing FPI and FGI, the fire risks decreased as the aging period increased, which means that early fire risks may be alleviated through the devolatilization of both the sheath and insulation of the cables. However, when comparing heat release and mass loss, which represent the fire risk at the mid and late period, fire intensity and severity increased with the aging period. The emission of toxic gases coincided with the results obtained from the heat release rate, which confirms that the toxicity of non-aged cables is higher than that of aged cables. From the results, it can be concluded that the aging period significantly affects both the combustion characteristics and toxicity of the emission gas. Therefore, cable degradation with aging should be considered when setting up reinforced safety codes and standards for cables and planning proper operation procedures for nuclear power plants.
An Efficient Hybrid Algorithm for Energy Expenditure Estimation for Electric Vehicles in Urban Service Enterprises
Authors: Izdebski Mariusz , Jacyna Marianna
Published: April 2021

The article deals with the decision problems of estimating the energy expenditure of low-emission fleets in urban service companies due to environmental safety. One of the most important problems of today’s transport policy of many city authorities is the ecological safety of its inhabitants. The basic measures are aimed at banning high-emission vehicles from city centers and promoting the introduction of zero-emission vehicles, such as electric or hybrid cars. The authors proposed an original approach to the decision model, in which the energy expenditure from the use of electric vehicles was defined as a criterion function. The boundary conditions took into account limitations typical of an electric vehicle, e.g., maximum range or battery charging time. To solve the problem, the authors proposed an efficient hybrid algorithm based on ant colony algorithm and genetic algorithm. The verification was made for the example of a utility company serving a medium-sized city in the eastern part of Poland.
Technological Solutions and Tools for Circular Bioeconomy in Low-Carbon Transition: Simulation Modeling of Rice Husks Gasification for CHP by Aspen PLUS V9 and Feasibility Study by Aspen Process Economic Analyzer
Authors: Almpantis Diamantis , Zabaniotou Anastasia
Published: April 2021

This study explored the suitability of simulation tools for accurately predicting fluidized bed gasification in various scenarios without disturbing the operational system, and dedicating time to experimentation, in the aim of benefiting the decision makers and investors of the low-carbon waste-based bioenergy sector, in accelerating circular bioeconomy solutions. More specifically, this study aimed to offer a customized circular bioeconomy solution for a rice processing residue. The objectives were the simulation and economic assessment of an air atmospheric fluidized bed gasification system fueled with rice husk, for combined heat and power generation, by using the tools of Aspen Plus V9, and the Aspen Process Economic Analyzer. The simulation model was based on the Gibbs energy minimization concept. The technological configurations of the SMARt-CHP technology were used. A parametric study was conducted to understand the influence of process variables on product yield, while three different scenarios were compared: (1) air gasification; (2) steam gasification; and (3) oxygen-steam gasification-based scenario. Simulated results show good accuracy for the prediction of H2 in syngas from air gasification, but not for the other gas components, especially regarding CO and CH4 content. It seems that the RGIBBS and Gibbs free minimization concept is far from simulating the operation of a fluidized bed gasifier. The air gasification scenario for a capacity of 25.000 t/y rice husk was assessed for its economic viability. The economic assessment resulted in net annual earnings of EUR 5.1 million and a positive annual revenue of EUR 168/(t/y), an excellent pay out time (POT = 0.21) and return of investment (ROI = 2.8). The results are dependent on the choices and assumptions made.
System Parameter Based Performance Optimization of Solar PV Systems with Perturbation Based MPPT Algorithms
Authors: Angadi Sachin , Yaragatti Udaykumar R. , Suresh Yellasiri , Raju A. B.
Published: April 2021

Maximum power point tracking (MPPT) algorithms are invariably employed to utilize solar photovoltaic (PV) systems effectively. Perturbation based MPPT algorithms are popular due to their simplicity and reasonable efficiency. While novel MPPT algorithms claim increased energy utilization over classic perturbation techniques, their performance is governed by the choice of optimal algorithm parameters. Existing guidelines for parameter optimization are mathematically laborious and are not generic. Hence, this paper aims to provide simple and comprehensive guidelines to ensure optimal performance from the perturbation based MPPT technique. For an illustration of proposed claims, a solar PV fed boost converter is investigated to examine the effect of input capacitor, digital filter cut-off frequency, system time constant and sampling time on implementing a classic Perturb and Observe (P and O) algorithm. The readers will be presented with two simple step tests (to determine the effective system time constant) and proposed guidelines to choose the optimal performance sampling time. Necessary laboratory experiments show that an appropriate choice of sampling time could increase efficiency and ensure system stability. This investigation’s learnings can be easily extended to any power electronics converter, loads and all perturbation-based algorithms used in solar PV systems. The results of appropriate tests on the system’s mathematical model and the laboratory prototype are presented in detail to support this research’s claims.
Improving the Solar Reliability Factor of a Dual-Axis Solar Tracking System Using Energy-Efficient Testing Solutions
Authors: Jurj Sorin Liviu , Rotar Raul , Opritoiu Flavius , Vladutiu Mircea
Published: April 2021

This paper presents an improved mathematical model for calculating the solar test factor (STF) and solar reliability factor (SRF) of a photovoltaic (PV) automated equipment. By employing a unified metrics system and a combined testing suite encompassing various energy-efficient testing techniques, the aim of this paper is to determine a general fault coverage and improve the global SRF of a closed-loop dual-axis solar tracking system. Accelerated testing coupled with reliability analysis are essential tools for assessing the performance of modern solar tracking devices since PV system malfunctioning is directly connected to economic loss, which is an important aspect for the solar energy domain. The experimental results show that the unified metrics system is potentially suitable for assessing the reliability evaluation of many types of solar tracking systems. Additionally, the proposed combined testing platform proves efficient regarding fault coverage (overall coverage of 66.35% for all test scenarios), test time (an average of 275 min for 2864 test cycles), and power consumption (zero costs regarding electricity consumption for all considered test cases) points of view.
Evaluating Profitability of Individual Timber Deliveries in the US South
Authors: Conrad Joseph L.
Published: April 2021

Timber transportation is an essential and often unprofitable segment of the wood supply chain. This study evaluated the profitability of individual timber deliveries for log truck owners in the US South. Origin and destination data were collected from 909 deliveries from 257 harvest sites. Travel time and distance were estimated using ArcGIS and GPS tracking. Monte Carlo Simulation was used to calculate 1000 unique combinations of payload, harvest site turn-time, mill turn-time, and percent-loaded km, yielding a dataset of 909,000 deliveries. Hauling costs and revenues for each delivery were estimated using published estimates. Driver wages were estimated in two ways: an hourly wage of $30.60 (USD) and 30% of the gross revenue from the load being delivered. Logistic regression was used to evaluate the relationship between six dependent variables and profitability. Only 14% of deliveries were profitable when the driver was paid an hourly wage versus 42% when the driver was paid 30% of gross revenue. Deliveries with one-way haul distances between 49 and 113 km (31–70 mi) were least likely to be profitable. Many deliveries could be profitable if logging businesses and mills reduced turn-times to under 20 min at mills and 30 min at harvest sites.
Chinese Traditional Fermented Soy Sauce Exerts Protective Effects against High-Fat and High-Salt Diet-Induced Hypertension in Sprague-Dawley Rats by Improving Adipogenesis and Renin-Angiotensin-Aldosterone System Activity
Authors: Zhong Bao , Mun Eun-Gyung , Wang Jin-Xi , Cha Youn-Soo
Published: April 2021

Although high-fat and high-salt diets are considered risk factors for hypertension, the intake of salty soybean-based fermented foods has beneficial effects. This study explored the potential of Chinese traditional fermented soy sauce (CTFSS) in preventing hypertension by analyzing its effects on adipogenesis and the renin-angiotensin-aldosterone system (RAAS). Male Sprague-Dawley (SD) rats were divided into four groups (n = 6): normal diet (ND), high-fat diet (HD), high-fat diet with saline (HDS, NaCl-8%), and high-fat diet with Chinese traditional soy sauce (HDCTS, NaCl-8%). Each group is administrated 12 weeks by oral gavage as 10 mL/kg dose, respectively. CTFSS supplementation resulted in significantly lower body weight, epididymal fat weight, and systolic blood pressure. Additionally, it decreased the serum total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), renin, angiotensin II (Ang II), angiotensin-converting enzyme (ACE), and aldosterone levels. It also increased the urinary volume and improved sodium and potassium ion balance. The gene levels showed significant enhancements in the mRNA levels of renin-angiotensin-aldosterone system-related and adipogenesis-related genes. In addition, CTFSS may prevent hypertension-associated kidney injury. Therefore, this study demonstrates that CTFSS has no harmful effects on hypertension. In contrast, the beneficial effects of CTFSS intake in ameliorating hypertension were shown.
Effects of Mesh Generation on Modelling Aluminium Anode Baking Furnaces
Authors: Libreros Jose , Trujillo Maria
Published: April 2021

Anode baking is critical in carbon anode production for aluminium extraction. Operational and geometrical parameters have a direct impact on the performance of anode baking furnaces (ABF), and hence on the resulting anode quality. Gas flow patterns, velocity field, pressure drop, shear stress and turbulent dissipation rate are the main operational parameters to be optimised, considering a specific geometry that is discretised as a mesh. Therefore, this paper aims to establish the need to generate an appropriate mesh to perform accurate numerical simulations of three-dimensional turbulent flow in a single section of an ABF. Two geometries are considered for generating three meshes, using COMSOL and cfMesh, with different refinement zones. The three meshes are used for creating nine incompressible isothermal turbulent flow models, with varying operational parameters. Velocity field, convergence and turbulent viscosity ratio in the outlet of fuel inlet pipes are the quantification criteria. Quantification criteria have shown that a better physical representation is obtained by refining in the whole combustion zone. COMSOL Multiphysics’ built-in mesh generator allows quadrilateral, tetrahedron and hexahedron shapes. Adaptive cell sizes and shapes have a place within modelling, since refining a mesh in appropriate zones brings the Peclet number down when the incompressible isothermal turbulent flow is simulated.
Physico-Chemical and Sensory Profiles of Enriched Linz Biscuits
Authors: Hlaváčová Zuzana , Ivanišová Eva , Harangozo Ľuboš , Petrović Ana , Kušteková Denisa , Gálik Branislav , Hlaváč Peter , Božiková Monika , Vozárová Vlasta
Published: April 2021

The aim of the present study was to determine the physico-chemical properties (dry matter content, combustion heat, electrical properties, total protein, ash, fat and crude fibre contents, selected amino acids, and trace elements), antioxidant content, and sensory profile of Linz biscuits. They were enriched by the addition of powdered carrot, nettle leaves and elderberry fruit, which is 3% of the product. For comparison of results, a control variant without the addition of these components was also prepared. The enriched biscuits showed slightly higher total ash and crude fibre contents in comparison to the control samples. Results for the antioxidant activity and total polyphenol, flavonoid, and phenolic acid contents of the enriched biscuits were higher in all observed parameters than in the control sample with the best results obtained for Linz biscuits enriched with elderberry and nettle powder. In enriched biscuits, higher contents of iron, zinc, and manganese were measured, especially in biscuits with nettle. Linz biscuits with nettle had higher combustion heat values than control samples; the other two sample types had lower values. We found that the resistance, capacitance, and relative permittivity of the enriched biscuits decreased with frequency according to the power regression function. On the contrary, the conductivity increased with an increasing frequency. Electrical properties were mainly influenced by the water content but also by added components.
Local Convergence and Dynamical Analysis of a Third and Fourth Order Class of Equation Solvers
Authors: Sharma Debasis , Argyros Ioannis K. , Parhi Sanjaya Kumar , Sunanda Shanta Kumari
Published: April 2021

In this article, we suggest the local analysis of a uni-parametric third and fourth order class of iterative algorithms for addressing nonlinear equations in Banach spaces. The proposed local convergence is established using an ω-continuity condition on the first Fréchet derivative. In this way, the utility of the discussed schemes is extended and the application of Taylor expansion in convergence analysis is removed. Furthermore, this study provides radii of convergence balls and the uniqueness of the solution along with the calculable error distances. The dynamical analysis of the discussed family is also presented. Finally, we provide numerical explanations that show the suggested analysis performs well in the situation where the earlier approach cannot be implemented.
The Arabidopsis JMJ29 Protein Controls Circadian Oscillation through Diurnal Histone Demethylation at the CCA1 and PRR9 Loci
Authors: Lee Hong Gil , Seo Pil Joon
Published: April 2021

The circadian clock matches various biological processes to diurnal environmental cycles, such as light and temperature. Accumulating evidence shows that chromatin modification is crucial for robust circadian oscillation in plants, although chromatin modifiers involved in regulating core clock gene expression have been limitedly investigated. Here, we report that the Jumonji C domain-containing histone demethylase JMJ29, which belongs to the JHDM2/KDM3 group, shapes rhythmic changes in H3K4me3 histone marks at core clock loci in Arabidopsis. The evening-expressed JMJ29 protein interacts with the Evening Complex (EC) component EARLY FLOWERING 3 (ELF3). The EC recruits JMJ29 to the CCA1 and PRR9 promoters to catalyze the H3K4me3 demethylation at the cognate loci, maintaining a low-level expression during the evening time. Together, our findings demonstrate that interaction of circadian components with chromatin-related proteins underlies diurnal fluctuation of chromatin structures to maintain circadian waveforms in plants.
Online Problem-Based Learning in Clinical Dental Education: Students’ Self-Perception and Motivation
Authors: Morgado Mariana , Mendes José João , Proença Luís
Published: April 2021

The physical closure of higher education institutions due to coronavirus disease 2019 (COVID-19) shed a brighter light on the need to analyze, explore, and implement strategies that allow the development of clinical skills in a distance learning situation. This cross-sectional study aims to assess dental students’ self-perception, motivation, organization, acquired clinical skills, and knowledge using the online problem-based learning method, through the application of a 41-item questionnaire to 118 senior students. Answers were subjected to descriptive and inferential statistics analysis. Further, a principal component analysis was performed, in order to examine the factor structure of the questionnaire. Results show that online problem-based learning can be considered a relevant learning tool when utilized within the specific context of clinical dental education, displaying benefits over the traditional learning strategy. Overall, dental students prefer a hybrid system over the conventional one, in a distance learning context, and assume self-responsibility for their own learning, while knowledge thoroughness is perceived as inferior. This online active learning method is successful in improving information and clinical ability (visual/spatial and auditory) advancement in the scope of dental education, with similar results to presential settings. Further studies are required to assess clinical skill development through active learning methods, in a distance learning context.
Effect of Line-Magnet Stimulation on HRV: A Double-Blind, Randomized, Crossover Trial
Authors: Jo Han-Gue
Published: April 2021

The acupuncture point mapped into the body meridian line has been the subject of extensive research; however, the scientific basis of the body meridian line remains unknown. In the present study, a pair of line-magnets was attached along the heart meridian line between HT4 and HT6 (intervention), and heart rate variability (HRV) was examined in a double-blind, randomized, crossover trial. Forty-five healthy young adults were randomly assigned into two groups and received two interventions in a different order. The only difference between the interventions was that the magnet pole was swapped. The results showed that the frequency-domain (LF, LF/HF) properties of HRV, which reflects underlying autonomic nervous system activity, changed when the magnetic pole’s direction along the heart meridian line was changed. This finding suggests that a line-magnet attached along to the heart meridian line may affect the cardiovascular system.
Multiple Amino Acids Inhibit Postharvest Senescence of Broccoli
Authors: Sohail Muhammad , Wills Ron , Bowyer Michael , Pristijono Penta
Published: April 2021

The function of free amino acids in protein synthesis, as a source of energy and unique roles in catabolism have been well studied in plant development but their function in postharvest fruit and vegetables has received little attention. This study evaluated 11 amino acids—arginine, alanine, aspartic acid, glutamic acid, glycine, ornithine, phenylalanine, serine, tyrosine, tryptophan and valine—on the development of senescence of broccoli. Broccoli florets were dipped in 5 mM solution of amino acids, then stored at 10 °C in air containing 0.1 µL L−1 ethylene. Senescence was assessed by green life, ethylene production, respiration rate and ion leakage. Green life was increased by all the amino acids except valine. Similarly, ethylene production and ion leakage were decreased by all the amino acids except valine, while respiration rate was reduced by all amino acids. It is speculated that the early reduction in ethylene production could be the mechanism by which the amino acids delayed senescence. The beneficial effect of naturally occurring amino acids in inhibiting senescence has potential commercial relevance, as the amino acids have Generally Recognised As Safe (GRAS) status which should assist gain regulatory approval, and gain acceptance by consumers wary of synthetic chemicals on foods.
Impact of the COVID-19 Pandemic on Teacher Quality of Life: A Longitudinal Study from before and during the Health Crisis
Authors: Lizana Pablo A. , Vega-Fernadez Gustavo , Gomez-Bruton Alejandro , Leyton Bárbara , Lera Lydia
Published: April 2021

Background: Prior to the COVID-19 pandemic, teachers were already reporting a low quality of life (QoL) perception, with a significant impact on mental and physical health due to various stress factors associated with work overload. The objective of this study was to evaluate the QoL impact on Chilean teachers before and during the COVID-19 pandemic. The analysis was performed following a longitudinal design on a sample of 63 Chilean teachers in pre-pandemic and COVID-19 pandemic timeframes. QoL perception, along with teachers’ sociodemographic data, was evaluated via the Short-Form 36 Health Survey (SF-36) questionnaire. Sociodemographic variables presented no significant variations in pre-pandemic and pandemic comparisons. QoL, however, showed a significant decrease during the pandemic compared to the pre-pandemic measurement (p < 0.01). In each gender, there were significant differences between pre-pandemic and pandemic timeframes, with a greater impact among women in the mental and physical component summary variables and seven of the eight QoL scales (p < 0.01). Between age categories, people under 45 presented significant differences (p < 0.05) between pre-pandemic and pandemic timeframes in all summary dimensions and measurements. In conclusion, Chilean teachers’ QoL perception has been affected by the COVID-19 pandemic. These findings could be related to work overload due to teleworking or feelings of uncertainty, loneliness, and fear that the pandemic and its associated confinements will worsen.
Evolution and Efficiency Assessment of Pesticide and Fertiliser Inputs to Cultivated Land in China
Authors: Zhan Xuesong , Shao Chaofeng , He Rong , Shi Rongguang
Published: April 2021

Excessive use of pesticides and fertilisers has been a key issue limiting sustainable agricultural development. China is a typical pesticide- and chemical-fertiliser-dependent agricultural production area. We have matched the target indicators related to sustainable agricultural development (SDG1 and SDG2) and analysed the gap between China and four developed countries in terms of fertiliser and pesticide use intensity and efficiency from 2002 to 2016. We have used an improved Logarithmic Mean Divisia Index model and cluster analysis to identify the factors and effects driving increased pesticide and fertiliser inputs in China, and we discuss the exploratory effects of different provinces in reducing pesticide and fertiliser application and increasing efficiency. The findings reveal that (1) China is a typical pesticide- and fertiliser-dependent agricultural production area. The average combined fertiliser application efficiency in China from 2002 to 2016 was only 28% of that of the Netherlands, and the country’s average combined pesticide application efficiency was only 35% of that of the USA. (2) The most important of the three main drivers of the increase in pesticide and fertiliser inputs in China is the value added of the primary industry, contributing 56% for the period 2007–2016. (3) Further analysis at the provincial level according to four types—high-intensity high-yield type, high-intensity low-yield type, low-intensity high-yield type, and low-intensity low-yield type—clarified the provinces that should be focused on at the national level in terms of pesticide and fertiliser application reduction and efficiency increase in the future.