bluuebunny/crossref_metadata_2025 huggingface dataset:
Post-Traumatic Intraparenchymal Renal Hemorrhages: Correlation between CT and DSA Vascular Findings for Superselective Embolization Procedures
Authors: Giurazza Francesco , Contegiacomo Andrea , Corvino Fabio , Rebonato Alberto , Castiglione Davide , Palmucci Stefano , Niola Raffaella , Basile Antonio
Published: July 2021

Background: This study aims to investigate the correlation between computed tomography (CT) and digital subtraction angiography (DSA) findings in patients affected by acute post-traumatic intraparenchymal renal hemorrhages and evaluate their conservative management with superselective embolization. Methods: This retrospective multicenter analysis focuses on patients affected by renal bleedings detected by contrast-enhanced CT and treated with superselective endovascular embolization. CT findings were compared to DSA. Embolization procedural data were analyzed and renal function was evaluated before and after the intervention. Results: Twenty-seven patients were retrospectively evaluated in one year. Compared to DSA, CT showed 96.3% diagnostic accuracy in terms of hemorrhage recognition; concerning the type of vascular lesion, there was discrepancy between CT and DSA in five cases. The technical success rate of embolization was 100%, while primary clinical success was 88.9%. The inferior parenchymal third was the most frequent site of renal injury. Microcoils were the most adopted embolics. Renal function did not change significantly before and after embolization. Conclusions: CT has elevated diagnostic accuracy in detecting post-traumatic intraparenchymal renal hemorrhages; in a small percentage, the type of vascular lesion may differ from the findings observed at DSA. In this scenario, superselective embolization presents high clinical success with a low complication rate.
A Systematic Review and Meta-Analysis of the Prognostic Impact of Pretreatment Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters in Patients with Locally Advanced Cervical Cancer Treated with Concomitant Chemoradiotherapy
Authors: Han Lu , Wang Qi , Zhao Lanbo , Feng Xue , Wang Yiran , Zou Yuliang , Li Qiling
Published: July 2021

Backgrounds: The purpose of this paper is to investigate the prognostic value of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) parameters in patients treated with concurrent chemoradiotherapy (CCRT) for locally advanced cervical cancer (LACC). Methods: Studies that met the following criteria were retrieved from PubMed and Embase: patients treated with CCRT for LACC; FDG PET/CT scans performed before CCRT treatment; and a detected relationship between the parameters of FDG PET/CT and the prognosis of patients. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to estimate the overall survival (OS) or event-free survival (EFS). Results: In total, 14 eligible studies with 1313 patients were included in this meta-analysis. Patients with a high maximum standardized uptake value (SUVmax) have a shorter OS than those with a low SUVmax (HR = 2.582, 95% = CI 1.936–3.443, p < 0.001). Primary tumor SUVmax values (HR = 1.938, 95% CI = 1.203–3.054, p = 0.004) were significantly correlated with EFS, with a relatively high heterogeneity (I2 = 84% and I2 = 69.4%, respectively). Based on the limited data, the combined HR for EFS with the highest primary tumor total lesion glycolysis (TLG) and metabolic tumor volume (MTV) was 1.843 (95% CI = 1.100–3.086, p = 0.02) and 2.06 (95% CI = 1.21–3.51, p = 0.007), respectively. Besides, the combined HR for OS with the highest nodal SUVmax was 2.095 (95% CI = 2.027–2.166, p < 0.001). Conclusion: A high primary SUVmax has a significant correlation with the OS and EFS of patients treated with CCRT for LACC and may therefore serve as a prognostic predictor. Due to the limited data, to explore the correlation between survival and TLG, MTV, and nodal SUVmax, further large-scale prospective studies are needed.
Dynapenia Rather Than Sarcopenia Is Associated with Metabolic Syndrome in Patients with Chronic Liver Diseases
Authors: Nishikawa Hiroki , Yoh Kazunori , Enomoto Hirayuki , Nishiguchi Shuhei , Iijima Hiroko
Published: July 2021

We aimed to examine the association between sarcopenia-related factors and metabolic syndrome (Met-S) in patients with chronic liver diseases (CLDs, n = 582, average age = 59.5 years, 290 males, 168 liver cirrhosis cases). Met-S was determined based on the Japanese criteria. Sarcopenia was determined based on grip strength (GS) and skeletal muscle index (SMI) by bioelectrical impedance analysis. Our cohort was divided into the four groups: (A) sarcopenia (n = 44), (B) dynapenia (n = 45), (C) presarcopenia (n = 112), and (D) the control (n = 381). Impacts of GS and SMI on Met-S were investigated. In males, waist circumference (WC) ≥ 85 cm was observed in 199 patients (68.6%), while in females, WC ≥ 90 cm was observed in 94 patients (32.2%). Met-S was identified in 109 patients (18.7%). The proportion of Met-S in the group A, B, C and D were 18.2%, 48.9%, 8.0%, and 18.4% (A vs. B, p = 0.0033; B vs. C, p < 0.0001; C vs. D, p = 0.0081; A vs. C, p = 0.0867; A vs. D, p = 1.000, B vs. D, p < 0.0001; overall p value < 0.0001). Multivariate analysis revealed that age, gender, and group B (dynapenia) were significant factors linked to the presence of Met-S. In conclusion, dynapenia rather than sarcopenia is associated with Met-S in CLD patients.
Usefulness of PET/CT with 18F-FDG in Patients with Differentiated Thyroid Carcinoma after Radioiodine Therapy: An Italian Multicenter Study
Authors: Filippi Luca , Frantellizzi Viviana , Monari Fabio , Lodi Rizzini Elisa , Tabacchi Elena , Pirisino Riccardo , Marongiu Andrea , Nuvoli Susanna , Bagni Oreste , De Vincentis Giuseppe , Schillaci Orazio , Spanu Angela
Published: July 2021

Background: our aim was to assess the diagnostic performance and clinical impact of 18F-FDG PET/CT in patients with differentiated thyroid carcinoma (DTC), previously treated with surgery and radioiodine therapy (RAI). Methods: patients subjected to 18F-FDG PET/CT for suspected DTC recurrence in three Italian nuclear medicine units were evaluated. Two different clinical settings were identified: clinical setting 1 included patients (n = 40) that were enrolled according to the American Thyroid Association guidelines (i.e., negative 1311-WBS and Tg level > 10 ng/mL); and clinical setting 2, that encompassed subjects (n = 26) with serum Tg ≤ 10 ng/mL but morphological findings suspected of relapse. PET/CT’s impact was scored as significant if it provided an indication for surgery, or led to a novel therapeutic decision. Results: In total, 51/66 patients (77.3%) were 18F-FDG positive, while 15 (22.7%) were negative. PET/CT showed an overall sensitivity and specificity of 84.4% and 75%, respectively. Sensitivity was higher in clinical setting 1 (89.1%) as compared to clinical setting 2 (76.1%), although this difference was not statistically significant (p = 0.83). PET/CT influenced clinical management in 28 cases (42.4%), without a significant difference between the 2 groups of patients (p = 0.6). Conclusions: our preliminary data, although limited by the retrospective nature of the study and possible selection bias, suggest that 18F-FDG PET/CT may be utilized for the detection of DTC recurrence in different clinical settings, with a meaningful impact on clinical management.
Transparent Memory Tests Based on the Double Address Sequences
Authors: Mrozek Ireneusz , Yarmolik Vyacheslav N.
Published: July 2021

An important achievement in the functional diagnostics of memory devices is the development and application of so-called transparent testing methods. This is especially important for modern computer systems, such as embedded systems, systems and networks on chips, on-board computer applications, network servers, and automated control systems that require periodic testing of their components. This article analyzes the effectiveness of existing transparent tests based on the use of the properties of data stored in the memory, such as changing data and their symmetry. As a new approach for constructing transparent tests, we propose to use modified address sequences with duplicate addresses to reduce the time complexity of tests and increase their diagnostic abilities.
Information Theory Based Evaluation of the RC4 Stream Cipher Outputs
Authors: Madarro-Capó  Evaristo José , Legón-Pérez  Carlos Miguel , Rojas Omar , Sosa-Gómez Guillermo
Published: July 2021

This paper presents a criterion, based on information theory, to measure the amount of average information provided by the sequences of outputs of the RC4 on the internal state. The test statistic used is the sum of the maximum plausible estimates of the entropies H(jt|zt), corresponding to the probability distributions P(jt|zt) of the sequences of random variables (jt)t∈T and (zt)t∈T, independent, but not identically distributed, where zt are the known values of the outputs, while jt is one of the unknown elements of the internal state of the RC4. It is experimentally demonstrated that the test statistic allows for determining the most vulnerable RC4 outputs, and it is proposed to be used as a vulnerability metric for each RC4 output sequence concerning the iterative probabilistic attack.
Teaching and Learning during the COVID-19 Pandemic: A Topic Modeling Study
Authors: Vijayan Ranjit
Published: July 2021

The coronavirus disease 2019 (COVID-19) pandemic caused significant disruption to teaching and learning activities at all levels. Faculty, students, institutions, and parents have had to rapidly adapt and adopt measures to make the best use of available resources, tools and teaching strategies. While much of the online teaching pedagogies have been theoretically and practically explored to a limited extent, the scale at which these were deployed was unprecedented. This has led a large number of researchers to share challenges, solutions and knowledge gleaned during this period. The main aim of this work was to thematically model the literature related to teaching and learning during, and about, COVID-19. Abstracts and metadata of literature were extracted from Scopus, and topic modeling was used to identify the key research themes. The research encompassed diverse scientific disciplines, including social sciences, computer science, and life sciences, as well as learnings in support systems, including libraries, information technology, and mental health. The following six key themes were identified: (i) the impact of COVID-19 on higher education institutions, and challenges faced by these institutions; (ii) the use of various tools and teaching strategies employed by these institutions; (iii) the teaching and learning experience of schools and school teachers; (iv) the impact of COVID-19 on the training of healthcare workers; (v) the learnings about COVID-19, and treatment strategies from patients; and (vi) the mental health of students as a result of COVID-19 and e-learning. Regardless of the key themes, what stood out was the inequities in education as a result of the digital divide. This has had a huge impact not only in middle- and low-income nations, but also in several parts of the developed world. Several important lessons have been learned, which, no doubt, will be actively incorporated into teaching and learning practices and teacher training. Nonetheless, the full effect of these unprecedented educational adaptions on basic education, expert training, and mental health of all stakeholders is yet to be fully fathomed.
Emergency Remote Teaching and Learning in Portugal: Preschool to Secondary School Teachers’ Perceptions
Authors: Seabra Filipa , Teixeira António , Abelha Marta , Aires Luísa
Published: July 2021

Emergency remote teaching and learning (ERTL) represent a critical and challenging time for teachers globally. To understand how Portuguese teachers interpreted their ERTL experiences of the first lockdown, we started by asking: What perspectives do teachers have about ERTL? Answering three open questions made available online between April and May of 2020, a sample of 305 preschool, basic, and secondary school teachers expressed their perspectives on (i) difficulties throughout ERTL; (ii) students’ constraints in participating in ERTL; (iii) the potential and benefits resulting from this exceptional period. Data were analyzed using content analysis. While Portuguese teachers perceived ERTL with concern, a majority also saw it as an opportunity. Workload, work conditions, and time management were the most frequently mentioned difficulties. Regarding students’ constraints, teachers emphasized participation, the role of parents, lack of contact, and autonomy. Despite the constraints and difficulties, teachers highlighted gains such as the development of digital competencies and the opportunity to transform teaching and learning. Only 18 teachers suggested there were no positive outcomes from this experience. Since this is an exploratory study, further studies are needed to triangulate the findings.
Working Methodology with Public Universities in Peru during the Pandemic—Continuity of Virtual/Online Teaching and Learning
Authors: Martín-Cuadrado Ana María , Lavandera-Ponce Silvia , Mora-Jaureguialde Begoña , Sánchez-Romero Cristina , Pérez-Sánchez Lourdes
Published: July 2021

This article describes the consultancy provided by the UTEC-UNED-TECSUP University Consortium to six national universities in Peru, during the COVID-19 state of emergency. This action aims to promote the techno-pedagogical change from a face-to-face to a virtual/online educational context. The process consists of three stages that ensured the continuity of the virtual/online educational service: diagnosis, design, and training, to strengthen instructional and digital competencies, support, and techno-pedagogical monitoring. It includes the basic principles of constructivist and constructionist learning theories for active and quality teaching and learning for the agents involved, and, in addition, the guidelines set by the emerging Peruvian regulations during the pandemic to move towards a digital university model according to the times. After a 157-day intervention, the analysis of the results raises some reflections: the importance of the socio-cultural context and its influence on the concept and development of the instructional act; the concept of distance learning in territories where connectivity is the main difficulty, and the university institution, in terms of a non-presential educational model with open and versatile methodologies, which anticipates a long process, involves a scheduled follow-up, requires fluid communication and demands continuous feedback.
Analyzing the Features Affecting the Performance of Teachers during Covid-19: A Multilevel Feature Selection
Authors: Saeed Alqahtani , Habib Raja , Zaffar Maryam , Quraishi Khurrum Shehzad , Altaf Oriba , Irfan Muhammad , Glowacz Adam , Tadeusiewicz Ryszard , Huneif Mohammed Ayed , Abdulwahab Alqahtani , Alduraibi Sharifa Khalid , Alshehri Fahad , Alduraibi Alaa Khalid , Almushayti Ziyad
Published: July 2021

COVID-19 is a profoundly contagious pandemic that has taken the world by storm and has afflicted different fields of life with negative effects. It has had a substantial impact on education which is evident from the transition from Face-to-Face (F2F) teaching to online mode of education and the rigid implementation of lockdown across the globe. This study examines the factors impacting the performance of teachers during the lockdown period of COVID-19 using various feature selection algorithms and Artificial Intelligence techniques. In this paper, we have proposed a novel multilevel feature selection for the prediction of the factors affecting the teachers’ satisfaction with online teaching and learning in COVID-19. The proposed multilevel feature selection is composed of the Fast Correlation Based Filter (FCBF), Mutual Information (MI), Relieff, and Particle Swarm Optimization (PSO) feature selection. The performance of the proposed feature selection approach is evaluated through the teachers’ benchmark dataset. We used a range of measures like accuracy, precision, f-measure, and recall to evaluate the performance of the proposed approach. We applied different machine learning approaches (SVM, LGBM, and ANN) with the proposed multilevel feature selection technique. The performance of the proposed approach is also compared with existing feature selection algorithms, and the results show the improvement in the performance of feature selection in terms of accuracy, precision, recall, and F-Measure. Proposed feature selection provides more than 80% accuracy with Light Weight Gradient Boosting Machine (LGBM).
Deep Convolutional Neural Network with RNNs for Complex Activity Recognition Using Wrist-Worn Wearable Sensor Data
Authors: Mekruksavanich Sakorn , Jitpattanakul Anuchit
Published: July 2021

Sensor-based human activity recognition (S-HAR) has become an important and high-impact topic of research within human-centered computing. In the last decade, successful applications of S-HAR have been presented through fruitful academic research and industrial applications, including for healthcare monitoring, smart home controlling, and daily sport tracking. However, the growing requirements of many current applications for recognizing complex human activities (CHA) have begun to attract the attention of the HAR research field when compared with simple human activities (SHA). S-HAR has shown that deep learning (DL), a type of machine learning based on complicated artificial neural networks, has a significant degree of recognition efficiency. Convolutional neural networks (CNNs) and recurrent neural networks (RNNs) are two different types of DL methods that have been successfully applied to the S-HAR challenge in recent years. In this paper, we focused on four RNN-based DL models (LSTMs, BiLSTMs, GRUs, and BiGRUs) that performed complex activity recognition tasks. The efficiency of four hybrid DL models that combine convolutional layers with the efficient RNN-based models was also studied. Experimental studies on the UTwente dataset demonstrated that the suggested hybrid RNN-based models achieved a high level of recognition performance along with a variety of performance indicators, including accuracy, F1-score, and confusion matrix. The experimental results show that the hybrid DL model called CNN-BiGRU outperformed the other DL models with a high accuracy of 98.89% when using only complex activity data. Moreover, the CNN-BiGRU model also achieved the highest recognition performance in other scenarios (99.44% by using only simple activity data and 98.78% with a combination of simple and complex activities).
Contribution of Voltage Support Function to Virtual Inertia Control Performance of Inverter-Based Resource in Frequency Stability
Authors: Orihara Dai , Kikusato Hiroshi , Hashimoto Jun , Otani Kenji , Takamatsu Takahiro , Oozeki Takashi , Taoka Hisao , Matsuura Takahiro , Miyazaki Satoshi , Hamada Hiromu , Mori Kenjiro
Published: July 2021

Inertia reduction due to inverter-based resource (IBR) penetration deteriorates power system stability, which can be addressed using virtual inertia (VI) control. There are two types of implementation methods for VI control: grid-following (GFL) and grid-forming (GFM). There is an apparent difference among them for the voltage regulation capability, because the GFM controls IBR to act as a voltage source and GFL controls it to act as a current source. The difference affects the performance of the VI control function, because stable voltage conditions help the inertial response to contribute to system stability. However, GFL can provide the voltage control function with reactive power controllability, and it can be activated simultaneously with the VI control function. This study analyzes the performance of GFL-type VI control with a voltage control function for frequency stability improvement. The results show that the voltage control function decreases the voltage variation caused by the fault, improving the responsivity of the VI function. In addition, it is found that the voltage control is effective in suppressing the power swing among synchronous generators. The clarification of the contribution of the voltage control function to the performance of the VI control is novelty of this paper.
Feeder Topology Configuration and Application Based on IEC 61850
Authors: Ge Haotian , Xu Bingyin , Zhang Xinhui , Bi Yongjian , Zhao Zida
Published: July 2021

Distribution automation (DA) and Internet of Things (IoT) all need the topology information of power distribution network to support some applications, such as fault diagnosis, network reconfiguration and optimization. IEC 61850 is a general communication model and standard for information exchange between intelligent electronic devices (IEDs). However, it has no mechanism for feeder topology information exchange. This paper solves this problem by developing the corresponding information model. Firstly, a feeder model is established as a container of the equipment along a distribution line. Secondly, logical models, such as terminal and connection nodes, are added to describe the physical connection relationship between the electrical equipment. Taking a circuit breaker as an example, this paper introduces how to add the terminal attribute to an existing logical node (XCBR). The physical connection between the circuit breaker and other electrical equipment is described by adding the logic node LCNN. Then, a new logical node LTPN is added to describe the logical connection between the devices. A new logical node, FTPA, is added to describe the status of the topology analysis and the topology results. Based on these new logical nodes, this paper proposes the mechanism of topology information exchange between IEDs. Three IEDs and the IEEE 13-node model are used to build an experimental environment. The result verifies the effectiveness of this method. More distributed applications can be used to test the validity and interoperability of the proposed model.
Techno-Economic Modelling of Micro-Hydropower Mini-Grids in Nepal to Improve Financial Sustainability and Enable Electric Cooking
Authors: Clements William , Pandit Surendra , Bajracharya Prashanna , Butchers Joe , Williamson Sam , Gautam Biraj , Harper Paul
Published: July 2021

In rural Nepal, micro-hydropower plant mini-grids provide renewable electricity to thousands of communities but the plants often have poor financial sustainability. Widespread uptake of electric cooking in such communities is currently not feasible due to high peak loads and limited capacity. In this paper, we develop a Remote-Areas Multi-Energy Systems Load Profiles (RAMP)-based stochastic techno-economic model for evaluating the economic viability of off-grid communities and improving their financial sustainability by introducing new appliances, productive end uses, and demand-side management measures. The model can be used to understand community electricity demand, assess economic status, determine equitable and profitable tariff structures, and plan new connections including electric cooking promotion or new industrial machines. Detailed electric cooking load modelling functionality was developed to represent Nepali cooking practices, scalable to approximate widespread uptake of electric cooking, and adaptable to other cookers and contexts. The model showed that a payment structure based on electricity consumption rather than a flat tariff could increase the income of a case study community in Eastern Nepal by 400%, although increased monthly payments for certain households from NPR 110 (USD 0.93) to NPR 500–1100 (USD 4.22–9.29) could present difficulty. However, households could reduce their electricity consumption and a more equitable tariff structure could be chosen while preserving plant profitability. The number of industrial machines such as mills could be doubled and up to 40 households provided with electric cookers if demand-side management measures were introduced.
Digital Twin Concepts with Uncertainty for Nuclear Power Applications
Authors: Kochunas Brendan , Huan Xun
Published: July 2021

Digital Twins (DTs) are receiving considerable attention from multiple disciplines. Much of the literature at this time is dedicated to the conceptualization of digital twins, and associated enabling technologies and challenges. In this paper, we consider these propositions for the specific application of nuclear power. Our review finds that the current DT concepts are amenable to nuclear power systems, but benefit from some modifications and enhancements. Further, some areas of the existing modeling and simulation infrastructure around nuclear power systems are adaptable to DT development, while more recent efforts in advanced modeling and simulation are less suitable at this time. For nuclear power applications, DT development should rely first on mechanistic model-based methods to leverage the extensive experience and understanding of these systems. Model-free techniques can then be adopted to selectively, and correctively, augment limitations in the model-based approaches. Challenges to the realization of a DT are also discussed, with some being unique to nuclear engineering, however most are broader. A challenging aspect we discuss in detail for DTs is the incorporation of uncertainty quantification (UQ). Forward UQ enables the propagation of uncertainty from the digital representations to predict behavior of the physical asset. Similarly, inverse UQ allows for the incorporation of data from new measurements obtained from the physical asset back into the DT. Optimization under uncertainty facilitates decision support through the formal methods of optimal experimental design and design optimization that maximize information gain, or performance, of the physical asset in an uncertain environment.
Estimation of Carbon Footprint of Residential Building in Warm Humid Climate of India through BIM
Authors: Kurian Rosaliya , Kulkarni Kishor Sitaram , Ramani Prasanna Venkatesan , Meena Chandan Swaroop , Kumar Ashok , Cozzolino Raffaello
Published: July 2021

In recent years Asian Nations showed concern over the Life Cycle Assessment (LCA) of their civil infrastructure. This study presents a contextual investigation of a residential apartment complex in the territory of the southern part of India. The LCA is performed through Building Information Modelling (BIM) software embedded with Environmental Product Declarations (EPDs) of materials utilized in construction, transportation of materials and operational energy use throughout the building lifecycle. The results of the study illustrate that cement is the material that most contributes to carbon emissions among the other materials looked at in this study. The operational stage contributed the highest amount of carbon emissions. This study emphasizes variation in the LCA results based on the selection of a combination of definite software-database combinations and manual-database computations used. For this, three LCA databases were adopted (GaBi database and ecoinvent databases through One Click LCA software), and the ICE database was used for manual calculations. The ICE database showed realistic value comparing the GaBi and ecoinvent databases. The findings of this study are valuable for the policymakers and practitioners to accomplish optimization of Greenhouse Gas (GHG) emissions over the building life cycle.
On the Physical Nature of Frequency Control Problems of Induction Motor Drives
Authors: Vladimir Kodkin , Alexander Anikin
Published: July 2021

This article considers the possibility of connecting the problems of the engineering synthesis of frequency control systems for induction motor drives (IMD) with the theory of the identification of IMD based on the equations of a generalized AC electric machine. The article presents experimental studies of load parrying in IMD with vector (VC) and scalar (SC) controls. These results indicate the absence of fundamental advantages in a drive with VC. This advantage should manifest in a more efficient formation of the moment and fast transients. A method was proposed for describing IMD by nonlinear transfer functions, making it possible to formulate the principle of the correction of IMD and a method for assessing their efficiency. The article shows that the correction based on the proposed nonlinear transfer functions of the induction motor is much more efficient than the traditional VC, which was confirmed by detailed experiments and modeling. The most important results are given in the article. An assumption was made that the efficiency advantage was due to more accurate identification of the dynamics of an IMD with a gear function instead of vector equations.
Possibilities of Limiting Migration of Natural Gas in Boreholes in the Context of Laboratory Studies
Authors: Kremieniewski Marcin , Wiśniowski Rafał , Stryczek Stanisław , Orłowicz Grzegorz
Published: July 2021

Gas migration through fresh and hardened cement slurry is an ongoing problem in the oil industry. In order to eliminate this unfavourable phenomenon, research is being conducted on new compositions of slurries for gas wells. The article presents the results of research for slurries with low and high resistance to gas migration. The proper selection of the quantity and quality of components makes it possible to design slurry with the required static structural strength values. In addition, the cement sheath of such anti-migration slurry has low porosity and a very low proportion of large pore spaces. Additionally, the mechanical parameters do not decrease during long-term deposition in borehole-like conditions. By obtaining these results, it was possible to design slurry whose cement sheath has high corrosion resistance. The new slurry has a lower water-cement ratio. Additionally, GS anti-migration copolymer, anti-filter additive and latex are used. The presence of n-SiO2 aqueous solution and microcement allows for sealing the microstructure of the hardened cement slurry. Such modifications significantly improve the technological parameters of the cement slurry and the cement coat formed from it.
Transition to Zero Energy and Low Carbon Emission in Residential Buildings Located in Tropical and Temperate Climates
Authors: Nematchoua Modeste Kameni , Orosa José A. , Ricciardi Paola , Obonyo Esther , Sambatra Eric Jean Roy , Reiter Sigrid
Published: July 2021

Different methods to achieve zero-energy and low carbon on the scale of a building are shown by most of the research works. Despite this, the recommendations generally offered by researchers do not always correspond to the realities found during the construction of new buildings in a determined region. Therefore, a standard may not be valid in all climate regions of the world. Being aware of this fact, a study was carried out to analyse the design of new buildings respecting the “zero-energy and low carbon emission” concept in tropical climatic regions when they are compared with a base case of temperate regions. To reach this objective, the comparison between real and simulated data from the different buildings studied was developed. The results showed that the renovation of existing residential buildings allows for reducing up to 35% of energy demand and a great quantity of CO2 emissions in both climate types. Despite this, the investment rate linked to the construction of zero-energy buildings in tropical zones is 12 times lower than in temperate zones and the payback was double. In particular, this effect can be related to the efficiency of photovoltaic panels, which is estimated to be, at least, 34% higher in tropical zones than temperate zones. Finally, this study highlights the interest and methodology to implement zero-energy buildings in tropical regions.
Linkages between Energy Delivery and Economic Growth from the Point of View of Sustainable Development and Seaports
Authors: Szaruga Elżbieta , Kłos-Adamkiewicz Zuzanna , Gozdek Agnieszka , Załoga Elżbieta
Published: July 2021

This paper presents the synchronisation of economic cycles of GDP and crude oil and oil products cargo volumes in major Polish seaports. On the one hand, this issue fits into the concept of sustainable development including decoupling; on the other hand, the synchronisation may be an early warning tool. Crude oil and oil products cargo volumes are a specific barometer that predicts the next economic cycle, especially as they are primary sources of energy production. The research study applies a number of TRAMO/SEATS methods, the Hodrick–Prescott filter, spectral analysis, correlation and cross-correlation function. Noteworthy is the modern approach of using synchronisation of economic cycles as a tool, which was described in the paper. According to the study results, the cyclical components of the cargo traffic and GDP were affected by the leakage of other short-term cycles. However, based on the cross-correlation, it was proved that changes in crude oil and oil products cargo volumes preceded changes in GDP by 1–3 quarters, which may be valuable information for decision-makers and economic development planners.
Evaluation of Soda Lignin from Wheat Straw/Sarkanda Grass as a Potential Future Consolidant for Archaeological Wood
Authors: Łucejko Jeannette J. , de Lamotte Anne , Andriulo Fabrizio , Kutzke Hartmut , Harding Stephen , Phillips-Jones Mary , Modugno Francesca , Slaghek Ted M. , Gosselink Richard J. A. , Braovac Susan
Published: July 2021

This work is part of a larger study, which aims to use soda lignin from straw as the starting point for a non-aqueous consolidant for highly degraded archaeological wood from the Oseberg collection. This wood was treated with alum salts in the early 1900s, is actively degrading and exists in varying states of preservation. Non-aqueous consolidants are an option to stabilize this wood mechanically in cases where it is too deteriorated to undergo aqueous-based retreatments, for example using polyethylene glycol. The aim of this study was to compare the extent of penetration of two soda lignin preparations in low- to medium-degraded archaeological pine. The soda lignins were dissolved in ethyl acetate and had two molecular weight groups: P1000 (molecular weight Mw of~3 kDa) and the ethyl acetate fraction FB01 (Mw of ~1 kDa). Penetration after immersion was evaluated by infrared spectroscopy and analytical pyrolysis. Treated specimens were also evaluated using weight and dimensional change and scanning electron microscopy. Both lignins penetrated into sample cores, but P1000 did not penetrate as well as FB01. This may be due to differences in their molecular weights, but also differences in polarity due to the presence of different functional groups.
Global Tree Taper Modelling: A Review of Applications, Methods, Functions, and Their Parameters
Authors: Salekin Serajis , Catalán Cristian Higuera , Boczniewicz Daniel , Phiri Darius , Morgenroth Justin , Meason Dean F. , Mason Euan G.
Published: July 2021

Taper functions are important tools for forest description, modelling, assessment, and management. A large number of studies have been conducted to develop and improve taper functions; however, few review studies have been dedicated to addressing their development and parameters. This review summarises the development of taper functions by considering their parameterisation, geographic and species-specific limitations, and applications. This study showed that there has been an increase in the number of studies of taper function and contemporary methods have been developed for the establishment of these functions. The reviewed studies also show that taper functions have been developed from simple equations in the early 1900s to complex functions in modern times. Early taper functions included polynomial, sigmoid, principal component analysis (PCA), and linear mixed functions, while contemporary machine learning (ML) approaches include artificial neural network (ANN) and random forest (RF). Further analysis of the published literature also shows that most of the studies of taper functions have been carried out in Europe and the Americas, meaning most taper equations are not specifically applicable to tropical tree species. Developing well-conditioned taper functions requires reducing the variation due to species, measurement techniques, and climatic conditions, among other factors. The information presented in this study is important for understanding and developing taper functions. Future studies can focus on developing better taper functions by incorporating emerging remote sensing and geospatial datasets, and using contemporary statistical approaches such as ANN and RF.
Influence of Prescribed Burning on a Pinus nigra subsp. Laricio Forest: Heat Transfer and Tree Vitality
Authors: Ferrat Lila , Morandini Frédéric , Lapa Gauthier
Published: July 2021

Surface fuel removal is crucial to facilitate the mitigation of severe fires in forests. Prescribed burning is often used by forest managers, thanks to its low cost and high efficiency in hard-to-reach areas. The determination of heat transfer between fires and trees has rarely been carried out on living species and consequently, their long-term effects on tree physiology are still not fully understood. In this study, a multidisciplinary approach was conducted to evaluate the impact of a late spring (June) prescribed burning on a Mediterranean pine forest (Pinus nigra subsp. laricio). The surface fuels consisted of a 656 g m−² needle litter, mixed with a few scattered living herbaceous strata. During the fire spread, measurements of the inner and outer trunk temperatures were made at the base of 12 trees with an average bark thickness of 19.4 ± 7.0 mm. The fireline intensity and flame residence time were in the range of 110–160 kW m−1 and 220–468 s, respectively. Despite a maximum heating rate at the cambial area of 4.37 °C min−1, the temperature of these tissues remained below 60 °C, a critical threshold above which thermal damage will occur. In addition, prior- and post-fire physiological monitoring was performed over a long time period (2.5 years) on 24 trees, using sap flow, chlorophyll fluorescence and gas exchange measurements. All parameters remain highly correlated and indicate that the burned trees did not suffer physiological damage. Moreover, drought resistance strategies were not altered by the prescribed burning. The thermal insulation capability of the bark allowed the functional tissues to experience low heat stress that did not affect tree vitality.
Aerodynamic Characteristics of a Single Airfoil for Vertical Axis Wind Turbine Blades and Performance Prediction of Wind Turbines
Authors: Mitchell Samuel , Ogbonna Iheanyichukwu , Volkov Konstantin
Published: July 2021

The design of wind turbines requires a deep insight into their complex aerodynamics, such as dynamic stall of a single airfoil and flow vortices. The calculation of the aerodynamic forces on the wind turbine blade at different angles of attack (AOAs) is a fundamental task in the design of the blades. The accurate and efficient calculation of aerodynamic forces (lift and drag) and the prediction of stall of an airfoil are challenging tasks. Computational fluid dynamics (CFD) is able to provide a better understanding of complex flows induced by the rotation of wind turbine blades. A numerical simulation is carried out to determine the aerodynamic characteristics of a single airfoil in a wide range of conditions. Reynolds-averaged Navier–Stokes (RANS) equations and large-eddy simulation (LES) results of flow over a single NACA0012 airfoil are presented in a wide range of AOAs from low lift through stall. Due to the symmetrical nature of airfoils, and also to reduce computational cost, the RANS simulation is performed in the 2D domain. However, the 3D domain is used for the LES calculations with periodical boundary conditions in the spanwise direction. The results obtained are verified and validated against experimental and computational data from previous works. The comparisons of LES and RANS results demonstrate that the RANS model considerably overpredicts the lift and drag of the airfoil at post-stall AOAs because the RANS model is not able to reproduce vorticity diffusion and the formation of the vortex. LES calculations offer good agreement with the experimental measurements.
Hemp (Cannabis sativa L.) Seed Protein–EGCG Conjugates: Covalent Bonding and Functional Research
Authors: Pang Xin-Hui , Yang Yang , Bian Xin , Wang Bing , Ren Li-Kun , Liu Lin-Lin , Yu De-Hui , Yang Jing , Guo Jing-Chun , Wang Lei , Zhang Xiu-Min , Yu Han-Song , Zhang Na
Published: July 2021

In order to make HPI have a wide application prospect in the food industry, we used EGCG to modify HPI. In this study, we prepared different concentrations (1, 2, 3, 4, and 5 mM) of (−)-epigallocatechin gallate (EGCG) covalently linked to HPI and use methods such as particle size analysis, circular dichroism (CD), and three-dimensional fluorescence spectroscopy to study the changes in the structure and functional properties of HPI after being covalently combined with EGCG. The particle size data indicated that the covalent HPI-EGCG complex was larger than native HPI, and the particle size was mainly distributed at about 200 μm. CD and three-dimensional fluorescence spectroscopy analyses showed that the conformation of the protein was changed by conjugation with EGCG. The β-sheet content decreased from 82.79% to 66.67% after EGCG bound to the protein, and the hydrophobic groups inside the protein were exposed, which increased the hydrophobicity of the protein and changed its conformation. After HPI and 1 mM of EGCG were covalently bonded, the solubility and emulsifying properties of the covalent complex were improved compared with native HPI. These results indicated that HPI-EGCG conjugates can be added in some foods.
Influence of the Initial Cell Number on the Growth Fitness of Salmonella Enteritidis in Raw and Pasteurized Liquid Whole Egg, Egg White, and Egg Yolk
Authors: Guillén Silvia , Marcén María , Álvarez Ignacio , Mañas Pilar , Cebrián Guillermo
Published: July 2021

Salmonella growth in egg and egg products has been widely studied, but there are still some aspects that are not fully known. The objective of this work was to study the influence of the initial cell number on the growth fitness of Salmonella Enteritidis in raw and pasteurized egg products. Growth curves of five Salmonella Enteritidis strains in raw and pasteurized egg products, starting from different initial numbers, were obtained and fitted to the Baranyi and Roberts model. The results revealed that lower initial numbers led to longer lag phases (λ) and lower maximum specific growth rates (μmax) in raw liquid whole egg. Similar results were observed in raw egg white (except for one strain). Conversely, no influence (p > 0.05) of the initial concentration on Salmonella growth parameters in raw egg yolk was observed. On the other hand, no influence of the initial number of cells on Salmonella growth fitness in commercial pasteurized liquid whole egg was observed. The results obtained demonstrate that the disappearance of this initial-dose dependency phenomenon was dependent on the intensity of the thermal treatment applied. Finally, the influence of the initial number was, in general, lower in pasteurized than in raw egg white, but large differences among strains were observed.
Consumer Acceptance of a Ready-to-Eat Meal during Storage as Evaluated with a Home-Use Test
Authors: Montero Maria Laura , Garrido Dolores , Gallardo R. Karina , Tang Juming , Ross Carolyn F.
Published: July 2021

A home-use test (HUT) is one method that provides a measure of ecological validity as the product is consumed in home under common daily use circumstances. One product that benefits from being evaluated in-home are ready-to-eat (RTE) meals. This study determined consumer acceptance of microwave-thermally-pasteurized jambalaya, a multi-meat and vegetable dish from American Cajun cuisine, and a control (cooked frozen jambalaya) through an on-line home-use test (HUT) over a 12-week storage period. Paralleling the HUT, an online auction determined consumers’ willingness to pay. The study also explored how the social environment may impact the liking of the meals when a partner of the participants joined the sensory evaluation of the meals. Consumers (n = 50) evaluated microwave-processed jambalaya stored at 2 °C and a control (cooked frozen jambalaya stored at −31 °C) after 2, 8 and 12 weeks of storage. Consumer liking of different sensory attributes was measured. Participants could choose to share the meals with a partner as a way to enhance ecological validity. The responses from 21 partners to the sensory-related questions were collected. After the sensory evaluation, the participants bid on the meal they had just sampled. Results showed that processing method (microwave vs. control) did not significantly influence the measured sensory attributes. Only flavor liking decreased over storage time (p < 0.05). The inclusion of partners significantly increased (p = 0.04) the liking of the appearance of the meals. The mean values of the bids for the meals ranged from $3.33–3.74, matching prices of commercially available jambalaya meals. This study found suggests that the shelf- life of microwave-processed meals could be extended up to 12 weeks without changing its overall liking. The study also shows the importance of exploring HUT methodology for the evaluation of consumers’ acceptance of microwave-processed jambalaya and how including a partner could contribute to enhance ecological validity.