bluuebunny/crossref_metadata_2025 huggingface dataset:
Sintering of Potassium Doped Hydroxy-Fluorapatite Bioceramics
Authors: Slimen Jihen Ben , Hidouri Mustapha , Ghouma Marwa , Salem Ezzedine Ben , Dorozhkin Sergey V.
Published: July 2021

The present study describes the influence of potassium and hydroxyl substitutions on the structural, thermal and mechanical properties of fluorapatite bioceramics. A set of non-stoichiometric ion-substituted compounds, with a chemical formula of Ca10−xKx(PO4)6F(2−2x)(OH)x with 0 ≤ x ≤ 1 synthesized by the wet precipitation method, were found to be single-phase apatites crystallizing in the hexagonal P63/m space group. The structural parameters, as well as the crystallite sizes, increased accordingly to the amount of added dopant-ions. The thermal behavior of these compounds, studied within the temperature range 500–1200 °C, indicated a partial decomposition of the apatitic phase and its transformation to tricalcium phosphate β-Ca3(PO4)2 at temperatures exceeding 750 °C. A relative density of the sintered samples achieved the highest value with x = 0.25 and reached about 95% after sintering at 1050 °C for 1 h. The microstructures of the sintered samples were of a trans-granular aspect and experienced an increase in the radius of their pores as x increased. The prepared bioceramic materials were mechanically characterized by means of Young’s modulus, flexural strength and fracture toughness measurements. The overall trend of these parameters evolved comparably to the relative density, and the maximum values obtained for x = 0.25 were measured to be 96 MPa, 47 MPa and 1.14 MPa·m1/2, respectively.
Improvement of Water Resistance of Vegetable Proteins by the Use of Synthetic Origin Additives: Trials with Resins and Metal Ions
Authors: Santoni Ilaria , Pizzo Benedetto
Published: July 2021

The adhesives industry is increasingly interested in products coming from natural and renewable resources. The aim of the present work was to improve the water resistance of soy-based proteins by using synthetic and formaldehyde-free additives. These include polyamide-amine epichlorohydrin (PAE), different types of isocyanates, and combinations of these cross-linkers between them and with other agents, including metal ions. In addition, the effect of both curing temperature and maturation time was assessed. Performances were evaluated by means of shear strength tests, solubility tests, and spectroscopic analysis. The obtained results showed that while isocyanates reacted completely but with water instead of proteins, tests with PAE were generally successful. In fact, the insoluble residue as well as the shear strength in wet conditions dramatically increased after PAE addition. Moreover, the wet performances of protein/PAE formulations appreciably increased gluing at 60 °C instead of room temperature. Furthermore, the maturation time had a positive effect on the formulations where metal ions were added, both for solubility and wet shear strength. Actually, for the very long conditioning time of 3 months, a significant and substantial increase of wet shear strength was observed for the series protein/PAE/aluminum.
α-MnO2 Nanowires as Potential Scaffolds for a High-Performance Formaldehyde Gas Sensor Device
Authors: Umar Ahmad , Ibrahim Ahmed , Kumar Rajesh , Algadi Hassan , Albargi Hasan , Ahmad Faheem , Zeng Wen , Akhtar M.
Published: July 2021

Herein, we report a chemi-resistive sensing method for the detection of formaldehyde (HCHO) gas. For this, α-MnO2 nanowires were synthesized hydrothermally and examined for ascertaining their chemical composition, crystal phase, morphology, purity, and vibrational properties. The XRD pattern confirmed the high crystallinity and purity of the α-MnO2 nanowires. FESEM images confirmed a random orientation and smooth-surfaced wire-shaped morphologies for as-synthesized α-MnO2 nanowires. Further, the synthesized nanowires with rounded tips had a uniform diameter throughout the length of the nanowires. The average diameter of the α-MnO2 nanowires was found to be 62.18 nm and the average length was ~2.0 μm. Further, at an optimized temperature of 300 °C, the fabricated HCHO sensor based on α-MnO2 nanowires demonstrated gas response, response, and recovery times of 19.37, 18, and 30 s, respectively.
Mechanistic Study on Gold-Like Luster Development of Solution-Cast Oligo(3-methoxythiophene) Film
Authors: Kubo Minako , Tachiki Minako , Mitogawa Terumasa , Saito Kota , Saito Ryota , Tsukada Satoru , Horiuchi Takahiko , Hoshino Katsuyoshi
Published: July 2021

Solution-cast coating films of perchlorate-doped oligo(3-methoxythiophene) exhibited a gold-like luster similar to that of metallic gold despite the involvement of no metals. However, the development mechanism of the luster remains ambiguous. To understand the mechanism, we performed scanning electron microscopic analysis, variable-angle spectral reflectance measurements, and ellipsometry measurements on ClO4−-doped oligo(3-methoxythiophene) cast film with a gold-like luster. The results revealed that the lustrous color of the film was not induced by the submicron-sized regular structures (structural color), nor by the high-density free electrons (reflective response based on Drude model), but by the large optical constants (refractive index and extinction coefficient) of the film, as speculated previously.
Alternating Direction Implicit (ADI) Methods for Solving Two-Dimensional Parabolic Interface Problems with Variable Coefficients
Authors: Li Chuan , Long Guangqing , Li Yiquan , Zhao Shan
Published: July 2021

The matched interface and boundary method (MIB) and ghost fluid method (GFM) are two well-known methods for solving elliptic interface problems. Moreover, they can be coupled with efficient time advancing methods, such as the alternating direction implicit (ADI) methods, for solving time-dependent partial differential equations (PDEs) with interfaces. However, to our best knowledge, all existing interface ADI methods for solving parabolic interface problems concern only constant coefficient PDEs, and no efficient and accurate ADI method has been developed for variable coefficient PDEs. In this work, we propose to incorporate the MIB and GFM in the framework of the ADI methods for generalized methods to solve two-dimensional parabolic interface problems with variable coefficients. Various numerical tests are conducted to investigate the accuracy, efficiency, and stability of the proposed methods. Both the semi-implicit MIB-ADI and fully-implicit GFM-ADI methods can recover the accuracy reduction near interfaces while maintaining the ADI efficiency. In summary, the GFM-ADI is found to be more stable as a fully-implicit time integration method, while the MIB-ADI is found to be more accurate with higher spatial and temporal convergence rates.
Distributed Interoperable Records: The Key to Better Supply Chain Management
Authors: Henninger Annegret , Mashatan Atefeh
Published: July 2021

The global supply chain is a network of interconnected processes that create, use, and exchange records, but which were not designed to interact with one another. As such, the key to unlocking the full potential of supply chain management (SCM) technologies is achieving interoperability across participating records systems and networks. We review existing research and solutions using distributed ledger technology (DLT) and provide a survey of its current state of practice. We additionally propose a holistic solution: a DLT-based interoperable future state that could enable the interoperable, efficient, reliable, and secure exchange of records with integrity. Finally, we provide a gap analysis between our proposed future state and the current state, which also serves as a gap analysis for many fractional DLT-based SCM solutions and research.
From Cosmetics to Innovative Cosmeceuticals—Non-Woven Tissues as New Biodegradable Carriers
Authors: Morganti Pierfrancesco , Morganti Gianluca , Gagliardini Alessandro , Lohani Alka
Published: July 2021

Due to pollution and climate-change fear, further increased by the COVID19 pandemic, consumers are looking for body and mind health by the request of more effective and safe products, including the anti-aging skincare cosmeceuticals.. The term “cosmeceuticals” was coined in 1962 as a fusion of cosmetic and pharmaceutical to cover a new class of products able to achieve aesthetic and drug-like benefits. They not only improve the skin’s appearance, but also treat different dermatological conditions, through a physiological activity, shown by in vitro and in vivo studies. This new category of cosmetics should contain no recognized drugs, but nonetheless have medicinal value. Consumers, in fact, are looking for products able to regenerate the skin and maintain not only a youthful appearance together with well-ness and well-being, but preserving the environment also. Consequently, they are searching for cosmetics and food made with high-quality natural ingredients, packaged with biodegradable materials and realized by sustainable technologies, possibly at zero waste. Consumers, in fact, are afraid of the pollution and plastics invading lands and oceans, causing many frequent disasters on our planet. New and smart tissues and films, made by polysaccharides and natural active ingredients, are proposed as innovative cosmeceuticals. These non-woven tissues, embedded by micro/nano complexes of chitin and lignin encapsulating different active ingredients, could represent a new category of vehicles that are characterized for their high effectiveness and safeness. Moreover, they do not induce allergic nor sensitizing phenomena, being biodegradable; skin- and environmentally friendly; and free of preservatives, emulsifiers, colors, fragrances and any kind of chemicals. Last but not least, polysaccharides, chitin and lignin may be obtained from industrial and agro-forestry waste, safeguarding the natural raw materials for the future generations.
On Modeling Concrete Compressive Strength Data Using Laplace Birnbaum-Saunders Distribution Assuming Contaminated Information
Authors: Alam Farouq Mohammad A. , Nassar Mazen
Published: July 2021

Compressive strength is a well-known measurement to evaluate the endurance of a given concrete mixture to stress factors, such as compressive loads. A suggested approach to assess compressive strength of concrete is to assume that it follows a probability model from which its reliability is calculated. In reliability analysis, a probability distribution’s reliability function is used to calculate the probability of a specimen surviving to a certain threshold without damage. To approximate the reliability of a subject of interest, one must estimate the corresponding parameters of the probability model. Researchers typically formulate an optimization problem, which is often nonlinear, based on the maximum likelihood theory to obtain estimates for the targeted parameters and then estimate the reliability. Nevertheless, there are additional nonlinear optimization problems in practice from which different estimators for the model parameters are obtained once they are solved numerically. Under normal circumstances, these estimators may perform similarly. However, some might become more robust under irregular situations, such as in the case of data contamination. In this paper, nine frequentist estimators are derived for the parameters of the Laplace Birnbaum-Saunders distribution and then applied to a simulated data set and a real data set. Afterwards, they are compared numerically via Monte Carlo comparative simulation study. The resulting estimates for the reliability based on these estimators are also assessed in the latter study.
From Bend to Splay Dominated Elasticity in Nematics
Authors: Revignas Davide , Ferrarini Alberta
Published: July 2021

In the past decade, much evidence has been provided for an unusually low cost for bend deformations in the nematic phase of bent-core mesogens and bimesogens (liquid crystal dimers) having a bent shape on average. Recently, an analogous effect was observed for the splay mode of bent-core mesogens with an acute apical angle. Here, we present a systematic computational investigation of the Frank elastic constants of nematics made of V-shaped particles, with bend angles ranging from acute to obtuse. We show that by tuning this angle, the elastic behavior switches from bend dominated (K33>K11) to splay dominated (K11>K33), with anomalously low values of the splay and the bend constant, respectively. This is related to a change in the shape polarity of particles, which is associated with the emergence of polar order, longitudinal for splay and transversal for bend deformations. Crucial to this study is the use of a recently developed microscopic elastic theory, able to account for the interplay of mesogen morphology and director deformations.
Microstructures and Mechanical Properties of Al-Ti-Zr-Nb-Ta-Mo-V Refractory High-Entropy Alloys with Coherent B2 Nanoprecipitation
Authors: Wang Zhenhua , Jin Dongming , Han Jincan , Wang Qing , Zhang Zhongwei , Dong Chuang
Published: July 2021

In this work, the microstructural evolution and mechanical properties of new body-centered cubic (BCC)-based Al-Ti-Zr-Nb-Ta-Mo-V refractory high-entropy alloys (RHEAs) with coherent B2 precipitation are investigated. These designed alloy ingots were solid-solutionized at 1573 K for 2 h and then aged at 873 K for 24 h, in which each treatment was followed by water quenching. It was found that there exists phase separation of BCC matrix, Ti/Zr-rich BCC1 and Nb/Ta-rich BCC2 in these alloys. Moreover, ultra-fine spherical B2 nanoparticles with a size of 3~5 nm were dispersed in BCC2 matrix. These B2 nanoparticles could be coarsened up to 25~50 nm after aging and the particle morphology also changes to a cuboidal shape due to a moderate lattice misfit (ε = 0.7~2.0%). Also, Zr5Al3 phase could coexist with the B2 phase, where the difference between them is that the Ti element is enriched in B2 phase, rather than in Zr5Al3. Among them, the solutionized Al2Ti5Zr4Nb2.5Ta2.5 RHEAs exhibit good compressive mechanical property with a high yield strength of 1240 MPa and a large plasticity, which is mainly attributed to the coherent precipitation in the BCC matrix.
Dealing with Randomness and Concept Drift in Large Datasets
Authors: Mwitondi Kassim S. , Said Raed A.
Published: July 2021

Data-driven solutions to societal challenges continue to bring new dimensions to our daily lives. For example, while good-quality education is a well-acknowledged foundation of sustainable development, innovation and creativity, variations in student attainment and general performance remain commonplace. Developing data -driven solutions hinges on two fronts-technical and application. The former relates to the modelling perspective, where two of the major challenges are the impact of data randomness and general variations in definitions, typically referred to as concept drift in machine learning. The latter relates to devising data-driven solutions to address real-life challenges such as identifying potential triggers of pedagogical performance, which aligns with the Sustainable Development Goal (SDG) #4-Quality Education. A total of 3145 pedagogical data points were obtained from the central data collection platform for the United Arab Emirates (UAE) Ministry of Education (MoE). Using simple data visualisation and machine learning techniques via a generic algorithm for sampling, measuring and assessing, the paper highlights research pathways for educationists and data scientists to attain unified goals in an interdisciplinary context. Its novelty derives from embedded capacity to address data randomness and concept drift by minimising modelling variations and yielding consistent results across samples. Results show that intricate relationships among data attributes describe the invariant conditions that practitioners in the two overlapping fields of data science and education must identify.
The Effect of Pooling on the Detection of the Nucleocapsid Protein of SARS-CoV-2 with Rapid Antigen Tests
Authors: Berking Tim , Lorenz Sabrina , Ulrich Alexander , Greiner Joachim , Kervio Eric , Bremer Jennifer , Wege Christina , Kleinow Tatjana , Richert Clemens
Published: July 2021

The COVID-19 pandemic puts significant stress on the viral testing capabilities of many countries. Rapid point-of-care (PoC) antigen tests are valuable tools but implementing frequent large scale testing is costly. We have developed an inexpensive device for pooling swabs, extracting specimens, and detecting viral antigens with a commercial lateral flow test for the nucleocapsid protein of SARS-CoV-2 as antigen. The holder of the device can be produced locally through 3D printing. The extraction and the elution can be performed with the entire set-up encapsulated in a transparent bag, minimizing the risk of infection for the operator. With 0.35 mL extraction buffer and six swabs, including a positive control swab, 43 ± 6% (n = 8) of the signal for an individual extraction of a positive control standard was obtained. Image analysis still showed a signal-to-noise ratio of approximately 2:1 at 32-fold dilution of the extract from a single positive control swab. The relative signal from the test line versus the control line was found to scale linearly upon dilution (R2 = 0.98), indicating that other pooling regimes are conceivable. A pilot project involving 14 participants and 18 pooled tests in a laboratory course at our university did not give any false positives, and an individual case study confirmed the ability to detect a SARS-CoV-2 infection with five-fold or six-fold pooling, including one swab from a PCR-confirmed COVID patient. These findings suggest that pooling can make frequent testing more affordable for schools, universities, and similar institutions, without decreasing sensitivity to an unacceptable level.
The Circumstances of Children with and without Disabilities or Significant Cognitive Delay Living in Ordinary Households in 30 Middle- and Low-Income Countries
Authors: Emerson Eric , Llewellyn Gwynnyth
Published: July 2021

Home-based early intervention is a key component of strategic approaches to preventing the loss of developmental potential among young children in middle- and low-income countries. We undertook secondary analysis of nationally representative data collected in 30 middle- and low-income countries during Round 6 (2017-) of UNICEF’s Multiple Indicator Cluster Surveys. Our analyses, involving over 100,000 children with/without disabilities or significant cognitive delay, indicated that children with disabilities and/or significant cognitive delay were more likely than their peers to: be living in relative household poverty and in rural areas; have a mother with only primary level education; live in households where intimate partner violence was considered acceptable by the child’s mother; be less likely to be receiving any pre-school education; have a mother with disabilities; receive low levels of parental stimulation; be exposed to violent parental discipline. For many of these indicators of poorer home circumstances, the level of risk was notably higher for children with significant cognitive delay than for children with disabilities. Our study findings suggest the need to consider tailored, evidence-based approaches to reduce and (potentially) overcome the increased risks that young children with disabilities and young children with significant cognitive delay experience in middle- and low-income countries.
Drone Trajectory Segmentation for Real-Time and Adaptive Time-Of-Flight Prediction
Authors: Conte Claudia , de Alteriis Giorgio , Schiano Lo Moriello Rosario , Accardo Domenico , Rufino Giancarlo
Published: July 2021

This paper presents a method developed to predict the flight-time employed by a drone to complete a planned path adopting a machine-learning-based approach. A generic path is cut in properly designed corner-shaped standard sub-paths and the flight-time needed to travel along a standard sub-path is predicted employing a properly trained neural network. The final flight-time over the complete path is computed summing the partial results related to the standard sub-paths. Real drone flight-tests were performed in order to realize an adequate database needed to train the adopted neural network as a classifier, employing the Bayesian regularization backpropagation algorithm as training function. For the network, the relative angle between two sides of a corner and the wind condition are the inputs, while the flight-time over the corner is the output parameter. Then, generic paths were designed and performed to test the method. The total flight-time as resulting from the drone telemetry was compared with the flight-time predicted by the developed method based on machine learning techniques. At the end of the paper, the proposed method was demonstrated as effective in predicting possible collisions among drones flying intersecting paths, as a possible application to support the development of unmanned traffic management procedures.
An Exploratory Investigation of UAS Regulations in Europe and the Impact on Effective Use and Economic Potential
Authors: Alamouri Ahmed , Lampert Astrid , Gerke Markus
Published: July 2021

Unmanned aircraft systems (UAS) have rapidly become more common in various applications. At the same time, the need for a safe UAS operation is of great importance to minimize and avoid risks that could arise with the deployment of this technology. With these requirements, UAS regulators in the European Union (EU) are making large efforts to enable a reliable legal framework of conditions for UAS operation to keep up with new capabilities of this technology and to minimize the risk of property damage and, most importantly, human injury. A recent outcome of the mentioned efforts is that new EU drone regulations are into force since 1 January 2021. In this paper we aim to provide a sound overview of recent EU drone regulations and the main changes to the rules since the first wave of regulations adopted in 2017. We highlight how such new rules help or hinder the use of UAS technology and its economic potential in scientific and commercial sectors by providing an exploratory investigation of UAS legal frames in Europe. An example of the impact of legislation on the operation of one particular UAS in Germany is provided, which has been in use since 2013 for atmospheric research.
Between Academic Resilience and Burnout: The Moderating Role of Satisfaction on School Context Relationships
Authors: Romano Luciano , Consiglio Piermarco , Angelini Giacomo , Fiorilli Caterina
Published: July 2021

School burnout is considered an extreme form of maladjustment that can seriously undermine the academic path of students who are affected. Previous studies have focused on possible protective factors, highlighting the role of academic resilience, i.e., the ability to overcome chronic adversity in the school setting. Notwithstanding this, it is equally important to explore the role of the classroom environment and the satisfaction felt by the student toward relationships with teachers and classmates. Therefore, the purpose of the present study was to examine the relationship between academic resilience and burnout and to explore the moderating role of relationship satisfaction with teachers and classmates. A sample of 576 Italian students (Female = 53.1%), aged 14–18 (M = 15.73, SD = 1.56) were involved in the study. Correlations and moderated regressions analyses were conducted to test the hypotheses. The results show academic resilience and satisfaction as inversely related to school burnout. Furthermore, the satisfaction on the relationships with classmates moderated the relation between academic resilience and burnout. Findings were discussed by highlighting the importance of promoting both individual and contextual factors to prevent burnout risk.
Signal Classification Algorithms over Time Selective Channels
Authors: Marey Mohamed , Mostafa Hala
Published: July 2021

In this work, we propose a general framework to design a signal classification algorithm over time selective channels for wireless communications applications. We derive an upper bound on the maximum number of observation samples over which the channel response is an essential invariant. The proposed framework relies on dividing the received signal into blocks, and each of them has a length less than the mentioned bound. Then, these blocks are fed into a number of classifiers in a parallel fashion. A final decision is made through a well-designed combiner and detector. As a case study, we employ the proposed framework on a space-time block-code classification problem by developing two combiners and detectors. Monte Carlo simulations show that the proposed framework is capable of achieving excellent classification performance over time selective channels compared to the conventional algorithms.
Recurrent Neural Network for Human Activity Recognition in Embedded Systems Using PPG and Accelerometer Data
Authors: Alessandrini Michele , Biagetti Giorgio , Crippa Paolo , Falaschetti Laura , Turchetti Claudio
Published: July 2021

Photoplethysmography (PPG) is a common and practical technique to detect human activity and other physiological parameters and is commonly implemented in wearable devices. However, the PPG signal is often severely corrupted by motion artifacts. The aim of this paper is to address the human activity recognition (HAR) task directly on the device, implementing a recurrent neural network (RNN) in a low cost, low power microcontroller, ensuring the required performance in terms of accuracy and low complexity. To reach this goal, (i) we first develop an RNN, which integrates PPG and tri-axial accelerometer data, where these data can be used to compensate motion artifacts in PPG in order to accurately detect human activity; (ii) then, we port the RNN to an embedded device, Cloud-JAM L4, based on an STM32 microcontroller, optimizing it to maintain an accuracy of over 95% while requiring modest computational power and memory resources. The experimental results show that such a system can be effectively implemented on a constrained-resource system, allowing the design of a fully autonomous wearable embedded system for human activity recognition and logging.
Lumped Parameter Modeling Based Power Loop Analysis Technique of Power Circuit Board with Wide Conduction Area for WBG Semiconductors
Authors: Lee Gi-Young , Cho Min-Shin , Kim Rae-Young
Published: July 2021

With the development of wide-bandgap (WBG) power semiconductor technology, such as silicon carbide (SiC) and gallium nitride (GaN), the technology of power converters with high efficiency and high-power density is rapidly developing. However, due to the high rate-of-rise of voltage (dv/dt) and of current (di/dt), compared to conventional Si-based power semiconductor devices, the reliability of the device is greatly affected by the parasitic inductance component in the switching loop. In this paper, we propose a power loop analysis method based on lumped parameter modeling of a power circuit board with a wide conduction area for WBG power semiconductors. The proposed analysis technique is modeled based on lumped parameters, so that power loops with various current paths can be analyzed; thus, the analysis is intuitive, easy to apply and realizes dynamic power loop analysis. Through the proposed analysis technique, it is possible to derive the effective parasitic inductance component for the main points in the power circuit board. The effectiveness of the lumped parameter model is verified through PSpice and Ansys Q3D simulation results.
Interference Mitigation and Power Minimization in 5G Heterogeneous Networks
Authors: Osama Mayada , El Ramly Salwa , Abdelhamid Bassant
Published: July 2021

Macro cells’ (MCs) densification with small cells (SCs) is one of the promising solutions to cope with the increasing demand for higher data rates in 5G heterogeneous networks (HetNets). Unfortunately, the interference that arises between these densely deployed SCs and their elevated power consumption have caused huge problems facing the 5G HetNets. In this paper, a new soft frequency reuse (SFR) scheme is proposed to minimize the interference and elevate the network throughput. The proposed scheme is based on on/off switching the SCs according to their interference contribution rate (ICR) values. It solves the interference problem of the densely deployed SCs by dividing the cell region into center and edge zones. Moreover, SCs on/off switching tackles the elevated power consumption problem and enhances the power efficiency of the 5G network. Furthermore, our paper tackles the irregular nature problem of 5G HetNets and compares between two different proposed shapes for the center zone of the SC: circular, and irregular shapes. Additionally, the optimum radius of the center zone, which maximizes the total system data rate, is obtained. The results show that the proposed scheme surpasses the traffic and the random on/off switching schemes, as it decreases the outage probability and enhances the total system data rate and power efficiency. Moreover, the results demonstrate the close performance of both the irregular and circular shapes for the center zone.
Design of Low Cross-Polarization Tri-Reflector CATR with Standard Quadric Surfaces Working in Terahertz
Authors: Li Zhi , Yao Yuan , Chen Tianyang , Yu Junsheng , Chen Xiaodong
Published: July 2021

In this paper, a tri-reflector compact antenna test range (CATR) consisting of a main parabolic reflector with a square aperture of 3 m in side length and two sub-reflectors of rotationally standard quadric surfaces working in terahertz is proposed. By using the equivalent paraboloid theory and cross-polarization elimination conditions and then combining with the appropriate shaped feed, the low cross-polarization and good quiet zone (QZ) performance of the system are achieved. The simulated results demonstrate that a cross-polarization isolation of >37 dB and a peak-to-peak amplitude (phase) ripple of <1.8 dB (13°) can be achieved on the principal cuts of the QZ at 100–500 GHz. At the same time, the QZ usage ratio of the CATR can reach 75%. The proposed tri-reflector CATR composed of standard quadric surfaces not only exhibits good quiet zone performance but also greatly reduces the manufacturing difficulty of the sub-reflectors and the construction cost of the system.
An Extended Semantic Interoperability Model for Distributed Electronic Health Record Based on Fuzzy Ontology Semantics
Authors: Adel Ebtsam , El-Sappagh Shaker , Barakat Sherif , Hu Jong-Wan , Elmogy Mohammed
Published: July 2021

Semantic interoperability of distributed electronic health record (EHR) systems is a crucial problem for querying EHR and machine learning projects. The main contribution of this paper is to propose and implement a fuzzy ontology-based semantic interoperability framework for distributed EHR systems. First, a separate standard ontology is created for each input source. Second, a unified ontology is created that merges the previously created ontologies. However, this crisp ontology is not able to answer vague or uncertain queries. We thirdly extend the integrated crisp ontology into a fuzzy ontology by using a standard methodology and fuzzy logic to handle this limitation. The used dataset includes identified data of 100 patients. The resulting fuzzy ontology includes 27 class, 58 properties, 43 fuzzy data types, 451 instances, 8376 axioms, 5232 logical axioms, 1216 declarative axioms, 113 annotation axioms, and 3204 data property assertions. The resulting ontology is tested using real data from the MIMIC-III intensive care unit dataset and real archetypes from openEHR. This fuzzy ontology-based system helps physicians accurately query any required data about patients from distributed locations using near-natural language queries. Domain specialists validated the accuracy and correctness of the obtained results.
Single-Shunt Three-Phase Current Measurement for a Three-Level Inverter Using a Modified Space-Vector Modulation
Authors: Kovačević Haris , Korošec Lucijan , Milanovič Miro
Published: July 2021

This article presents a single-shunt measurement of a three-level inverter using a modified space-vector modulation to reconstruct the three-phase load current. The proposed method was implemented on a digital signal processor (DSP), and the algorithm was verified in the laboratory experiment. Through the work, it was proven that the single-shunt three-phase current measurement could be performed using the space-vector modulation for three-level inverters in an analogous way to ordinary three-phase inverters. Three-phase current reconstruction for ordinary three-phase inverters was performed using the ordinary space-vector modulation with eight vectors, but for three-level inverters, 21 vectors were available. When the inverter was working on the edges between two vectors, the modulation disturbances appeared as current spikes. This problem was solved using the modified SVM performed by shifting the SVM signals. Carefully designed signal shifting (vector injection) demonstrated an excellent reconstruction of the three-phase load currents that were single-shunt measured.
Climate Connectivity of European Forests for Species Range Shifts
Authors: Han Qiyao , Keeffe Greg , Cullen Sean
Published: July 2021

Forest connectivity is important for the range shifts and long-term persistence of forest-dependent species, especially in the context of climate change. This study assessed the climate connectivity of European forests for species to track suitable climate conditions as the climate warms. Here, climate connectivity was calculated as the temperature difference between each forest patch and the coolest patch that can be reached along temperature gradients. We found that, overall, about 36% of the total forested area in Europe has achieved successful climate connectivity under the moderate emission scenario (SSP245), whereby species range shifts could circumvent the impact of climate warming. The percentage is much lower under the highest emission scenario (SSP585), which is only 12%. To identify forest areas of high importance for climate connectivity, we further evaluated the potential of each forest patch to serve as a stepping stone for species range shifts. Our results showed that about 94% of the European forested area is expected to experience species range shifts. Our study identified sites of high conservation value for improving and sustaining forest connectivity to facilitate climate-driven range shifts and thus could provide information for climate-smart management of European forests.
Felled and Lure Trap Trees with Uncut Branches Are Only Weakly Attractive to the Double-Spined Bark Beetle, Ips duplicatus
Authors: Šotola Vojtěch , Holuša Jaroslav , Kuželka Karel , Kula Emanuel
Published: July 2021

Bark beetles are the most important forest pests in the Northern Hemisphere. The range of Ips duplicatus, an invasive bark beetle in central Europe, has been steadily expanding, and it is now responsible for a high proportion of the spruce wood infested by bark beetles. Apart from searching for and eliminating infested trees, there is no effective control method. The aim of this study was to determine whether trap trees with a pheromone evaporator can be used to capture I. duplicatus. Felled trap trees with branches and with pheromone lures (ID Ecolure®) were infested by I. duplicatus, at a median density of 1 nuptial chambers per 0.1 m2 (median); similar trees without lures and lying at a distance of 1, 5, or 10 m from the lure trees were rarely infested by I. duplicatus. The entire surface of the lure trees could capture <400 beetles per tree. The results indicate that lure trap trees (felled and with branches attached) could only be used in a limited number of situations; one such situation would involve forests that suffered wind damage and contained very high numbers of I. duplicatus.
Marked Differences in Butterfly Assemblage Composition between Forest Types in Central Amazonia, Brazil
Authors: Oliveira Isabela Freitas , Baccaro Fabricio Beggiato , Werneck Fernanda P. , Zacca Thamara , Haugaasen Torbjørn
Published: July 2021

Amazonia comprises a mosaic of contrasting habitats, with wide environmental heterogeneity at local and regional scales. In central Amazonia, upland forest (terra firme) is the predominant forest type and seasonally flooded forests inundated by white- and black-water rivers (várzea and igapó, respectively) represent around 20% of the forested areas. In this work, we took advantage of a natural spatial arrangement of the main vegetation types in central Amazonia to investigate butterfly assemblage structure in terra firme, várzea and igapó forests at the local scale. We sampled in the low- and high-water seasons, combining active and passive sampling with traps placed in both the understory and canopy. Terra firme supported the highest number of butterfly species, whereas várzea forest provided the highest number of butterfly captures. The high species richness in terra firme may reflect that this forest type is floristically richer than várzea and igapó. Várzea is a very productive environment and may thus support a higher number of butterfly individuals than terra firme and igapó. Most butterfly species (80.2%) were unique to a single forest type and 17 can be considered forest type indicator species in this landscape. Floodplain forest environments are therefore an important complement to terra firme in terms of butterfly species richness and conservation in Amazonia.
Professionals’ Feedback on the PEFC Fair Supply Chain Project Activated in Italy after the “Vaia” Windstorm
Authors: Negro Francesco , Espinoza Omar , Brunori Antonio , Cremonini Corrado , Zanuttini Roberto
Published: July 2021

In the fall of 2018, the “Vaia” windstorm grounded around 8.5 million m3 of timber in northeastern Italy. Soon after, the Programme for the Endorsement of Forest Certification (PEFC) Italy activated a project called “fair supply chain” to promote the purchase of timber from the damaged areas at a reasonable price. The initiative was addressed at forest owners, forest and processing enterprises, retailers, and supporting organizations. This study reports the results of a survey performed to assess the effectiveness of the project two years after its launch. The survey, in the form of a questionnaire submitted to all adhering organizations, investigated different aspects such as motivations for adherence to the project, satisfaction with the project, sale of the labeled material, and promotion of the specific label. The results provide a detailed outline of the above aspects. Through the various findings, the project is perceived as effective in supporting the region, enhancing an organizations’ image, and limiting price fall. Yet, further efforts should be aimed at increasing networking and business opportunities. Some recommendations are also offered for similar projects in the future, as forest disturbances are increasing worldwide in frequency and intensity due to climate change.
Phenotypic Variability and Differences in the Drought Response of Norway Spruce Pendula and Pyramidalis Half-Sib Families
Authors: Budeanu Marius , Apostol Ecaterina Nicoleta , Besliu Emanuel , Crișan Vlad Emil , Petritan Any Mary
Published: July 2021

In a changing climate, forest managers need to select productive and climate-change-resilient tree species and provenances. Therefore, assessing the growth response of provenances growing in field trials to climate provides useful information for identifying the more appropriate provenance or variety. To determine the genetic gain through selection of the most productive and resilient families and to decipher the role of crown forms of Norway spruces (Picea abies (L.) Karst.), we used 24 families with a classical crown (pyramidalis) and 24 with a narrow crown (pendula) from eight provenances, growing in a 25-year-old comparative trial. The annual wood characteristics (ring width and early- and latewood), the wood resistance (expressed by latewood proportion (LWP)), and the growth response to climate of the two spruce crown forms were investigated. No significant differences between the two spruce forms were found regarding the ring width characteristics. However, three pendula families of Stâna de Vale I provenance exhibited the highest LWP and could be included in a future selection strategy, the respective trait having also high heritability. Radial growth was positively and significantly correlated with previous September and current July precipitation and negatively with current June temperature. Both spruce forms showed good recovery capacity after a drought event.
Bioclimatic Suitability of Actual and Potential Cultivation Areas for Jacaranda mimosifolia in Chinese Cities
Authors: Xie Chunping , Zhang Guowu , Jim Chiyung , Liu Xuefeng , Zhang Peijian , Qiu Jianhuang , Liu Dawei
Published: July 2021

Jacaranda mimosifolia is regarded as a prized ornamental tree in the urban landscape with attractive, abundant and long-lasting violet-colored flowers and graceful tree form. It has been widely cultivated in recent years in many Chinese cities. However, the lack of scientific and practical guidance to cultivate the exotic species has brought about planting failures in some areas, incurring substantial economic losses and landscape decline. A comprehensive understanding of the current spatial pattern and climatic conditions of J. mimosifolia in China can inform species choice, planting and management. We collected data on the geographical coordinates of 257 planting cities and acquired additional information from the literature and field surveys. The limiting factors for cultivation were investigated using principal component analysis (PCA) of 19 bioclimatic parameters of the sampled sites. The potentially suitable habitats were predicted by BIOCLIM modeling using eight selected ecological-important climatic parameters. We found that the present cultivated areas were focused in the low-altitude parts of the subtropical zone, mainly covering the provinces of Yunnan, Sichuan, Guangxi, Guangdong and Fujian. The PCA results indicated that temperature was the clinching determinant of the current cultivation patterns, especially annual mean temperature, the minimum temperature of the coldest month and the mean temperature of the warmest quarter. Moisture was a necessary but not critical secondary factor. The predicting model for potential habitats was graded as “excellent” by objective validation measures. The findings can provide science-based evidence to plan the expansion of the biogeographical range of cultivation into hitherto unplanted cities and rationalize urban tree introduction and management practices.
Utilization of Yeast Waste Fermented Citric Waste as a Protein Source to Replace Soybean Meal and Various Roughage to Concentrate Ratios on In Vitro Rumen Fermentation, Gas Kinetic, and Feed Digestion
Authors: Suriyapha Chaichana , Cherdthong Anusorn , Suntara Chanon , Polyorach Sineenart
Published: July 2021

The objective of this study was to determine the application of citric waste fermented yeast waste (CWYW) obtained from an agro-industrial by-product as a protein source to replace soybean meal (SBM) in a concentrate diet. We also determined the effect of various roughage to concentrate ratios (R:C) on the gas production kinetics, ruminal characteristics, and in vitro digestibility using an in vitro gas production technique. The experiment design was a 3 × 5 factorial design arranged in a completely randomized design (CRD), with three replicates. There were three R:C ratios (60:40, 50:50, and 40:60) and five replacing SBM with CWYW (SBM:CWYW) ratios (100:0, 75:25, 50:50, 25:75, and 0:100). The CWYW product’s crude protein (CP) content was 535 g/kg dry matter (DM). There was no interaction effect between R:C ratios and SBM:CWYW ratios for all parameters observed (p > 0.05). The SBM:CWYW ratio did not affect the kinetics and the cumulative amount of gas. However, the gas potential extent and cumulative production of gas were increased with the R:C ratio of 40:60, and the values were about 74.9 and 75.0 mL/0.5 g, respectively (p < 0.01). The replacement of SBM by CWYW at up to 75% did not alter in vitro dry matter digestibility (IVDMD), but 100% CWYW replacement significantly reduced (p < 0.05) IVDMD at 24 h of incubation and the mean value. In addition, IVDMD at 12 h and 24 h of incubation and the mean value were significantly increased with the R:C ratio of 40:60 (p < 0.01). The SBM:CWYW ratio did not change the ruminal pH and population of protozoa (p > 0.05). The ruminal pH was reduced at the R:C ratio of 40:60 (p < 0.01), whereas the protozoal population at 4 h was increased (p < 0.05). The SBM:CWYW ratio did not impact the in vitro volatile fatty acid (VFA) profile (p > 0.05). However, the total VFA, and propionate (C3) concentration were significantly increased (p < 0.01) by the R:C ratio of 40:60. In conclusion, the replacement of SBM by 75% CWYW did not show any negative impact on parameters observed, and the R:C ratio of 40:60 enhanced the gas kinetics, digestibility, VFA, and C3 concentration.
The Effect of pH and Storage Temperature on the Stability of Emulsions Stabilized by Rapeseed Proteins
Authors: Östbring Karolina , Matos María , Marefati Ali , Ahlström Cecilia , Gutiérrez Gemma
Published: July 2021

Rapeseed press cake (RPC), the by-product of rapeseed oil production, contains proteins with emulsifying properties, which can be used in food applications. Proteins from industrially produced RPC were extracted at pH 10.5 and precipitated at pH 3 (RPP3) and 6.5 (RPP6.5). Emulsions were formulated at three different pHs (pH 3, 4.5, and 6) with soy lecithin as control, and were stored for six months at either 4 °C or 30 °C. Zeta potential and droplet size distribution were analyzed prior to incubation, and emulsion stability was assessed over time by a Turbiscan instrument. Soy lecithin had significantly larger zeta potential (−49 mV to 66 mV) than rapeseed protein (−19 mV to 20 mV). Rapeseed protein stabilized emulsions with smaller droplets at pH close to neutral, whereas soy lecithin was more efficient at lower pHs. Emulsions stabilized by rapeseed protein had higher stability during storage compared to emulsions prepared by soy lecithin. Precipitation pH during the protein extraction process had a strong impact on the emulsion stability. RPP3 stabilized emulsions with higher stability in pHs close to neutral, whereas the opposite was found for RPP6.5, which stabilized more stable emulsions in acidic conditions. Rapeseed proteins recovered from cold-pressed RPC could be a suitable natural emulsifier and precipitation pH can be used to monitor the stability in emulsions with different pHs.
An Unofficial Account of the Beginnings of VLBI Polarimetry: From Jodrell Bank to the Event Horizon Telescope
Authors: Wardle John
Published: July 2021

I offer a brief and personal history of the development of polarization sensitive observations with widely separated antennas. The story starts at Jodrell Bank in the late 1960s with a 24 km baseline radio linked (but not phase stable) interferometer and reaches to the present Event Horizon Telescope (with global span and independent atomic clocks) which has just published an image of the linearly polarized radiation surrounding the black hole shadow of M87*. I was privileged to be witness to many of the developments along the way, either as an instigator, a bystander, or an unindicted co-conspirator. I am most interested in the technical developments that enabled these increasingly sophisticated observations, and in the ideas that advanced the data analysis and imaging.