bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Surface Modification with Stearic Acid on the Dispersion of Some Inorganic Fillers in PE Matrix
Authors: Nguyen Thanh Tung , Nguyen Van Khoi , Pham Thi Thu Ha , Pham Thu Trang , Nguyen Trung Duc
Published: October 2021

To evaluate the effects of surface modification with stearic acid on the dispersion of some inorganic fillers in polyethylene (PE) matrix, masterbatches containing 20–40 wt% of stearic acid uncoated and coated inorganic fillers and the linear low-density polyethylene (LLDPE) films containing 3–7% stearic acid uncoated and coated inorganic fillers were prepared. Two types of inorganic fillers used in the masterbatch included bentonite and silica. The structural change of inorganic fillers, whose surface was modified with stearic acid, was studied using IR spectroscopy. The dispersion of inorganic fillers in LLDPE matrix was evaluated using scanning electron microscope (masterbatch samples) and optical microscope (film samples). Changes in the melting temperature of LLDPE in the presence of inorganic fillers were evaluated by using differential scanning calorimeter (DSC). The mechanical properties of the films were evaluated according to ASTM D882. Surface-treated fillers with stearic acid dispersed in the masterbatches and films better than untreated fillers did. Stearic acid did not change the melting temperature of the filler/PE masterbatches. The mechanical properties of the films containing stearic acid coated fillers were higher than those containing unmodified fillers.
Evaluation of Maraging Steel Produced Using Hybrid Additive/Subtractive Manufacturing
Authors: Sarafan Sheida , Wanjara Priti , Gholipour Javad , Bernier Fabrice , Osman Mahmoud , Sikan Fatih , Molavi-Zarandi Marjan , Soost Josh , Brochu Mathieu
Published: October 2021

Hybrid manufacturing is often used to describe a combination of additive and subtractive processes in the same build envelope. In this research study, hybrid manufacturing of 18Ni-300 maraging steel was investigated using a Matsuura LUMEX Avance-25 system that integrates metal additive manufacturing using laser powder bed fusion (LPBF) processing with high-speed machining. A series of benchmarking coupons were additively printed at four different power levels (160 W, 240 W, 320 W, 380 W) and with the integration of sequential machining passes after every 10 deposited layers, as well as final finishing of selected surfaces. Using non-contact three-dimensional laser scanning, inspection of the final geometry of the 18Ni-300 maraging steel coupons against the computer-aided design (CAD) model indicated the good capability of the Matsuura LUMEX Avance-25 system for net-shape manufacturing. Linear and areal roughness measurements of the surfaces showed average Ra/Sa values of 8.02–14.64 µm for the as-printed walls versus 0.32–0.80 µm for the machined walls/faces. Using Archimedes and helium (He) gas pycnometry methods, the part density was measured to be lowest for coupons produced at 160 W (relative density of 93.3–98.5%) relative to those at high power levels of 240 W to 380 W (relative density of 99.0–99.8%). This finding agreed well with the results of the porosity size distribution determined through X-ray micro-computed tomography (µCT). Evaluation of the static tensile properties indicated that the coupons manufactured at the lowest power of 160 W were ~30% lower in strength, 24% lower in stiffness, and more than 80% lower in ductility relative to higher power conditions (240 W to 380 W) due to the lower density at 160 W.
Beach Response to a Shoreface Nourishment (Aveiro, Portugal)
Authors: Mendes Diogo , Pais-Barbosa Joaquim , Baptista Paulo , Silva Paulo A. , Bernardes Cristina , Pinto Celso
Published: October 2021

In Aveiro (NW coast of Portugal), a coastal monitoring programme was carried out in sequence of a shoreface nourishment intervention (over than 2 M m3) performed in 2020. In this programme, almost one year of biweekly subaerial topographies and quarterly bathymetric surveys have been collected along a 10 km coastal stretch between June 2020 and June 2021. In this study, topographic and bathymetric surveys were analysed to assess the expectation that if the shoreface nourishment is located in sufficiently shallow water depths, its landward movement will feed adjacent beaches and, consequently, increase the subaerial beach volume. Results show that the subaerial beach volume is well correlated with the 1.05 m (above MSL) isoline displacement through time. While the seaward limit of the shoreface nourishment moved landwards about 200 m, the shoreline proxy (isoline of 1.05 m) displayed a maximum seaward displacement of 60 m. The displacement of the shoreline proxy was highly variable in space, along the 10 km coastal stretch, and also in time, during storm events. During such events, both landward and seawards displacement of the shoreline proxy took place, depending on the spatial position. Moreover, while beaches close to the initial shoreface nourishment intervention displayed faster accretion patterns than those located farther away, the well-defined onshore movement of the shoreface nourishment did not result in a considerable beach volume increase. The achieved results were also compared against case studies of shoreface nourishments with similar volumes performed worldwide.
The Development of a Transdisciplinary Framework to Overcome Energy Efficiency Barriers in Shipbuilding: A Case Study for an Iranian Shipyard
Authors: Vakili Seyed Vahid , Ölçer Aykut I. , Schönborn Alessandro
Published: October 2021

Through a systematic literature review and a holistic perspective, the study proposes a conceptual transdisciplinary framework to overcome energy efficiency barriers during the shipbuilding phase. The process of the proposed transdisciplinary framework consists of five steps of “goal formation”, “system analyzing”, “scenario construction”, “multi-criteria decision making assessment” and “strategy building” to identify and rank the energy efficiency barriers during ship construction based on decision makers’ priorities. The framework categorizes the barriers into five disciplines—operations, policies and regulations, technology and innovation, the human elements, and economics—and the framework is applied to an Iranian shipyard. The results show that the economic barriers have the greatest impact, while the human barriers have the least impact on the shipyard’s energy performance. Due to the generalized structure of the framework, it categorizes not only energy efficiency barriers according to the importance and priorities of stakeholders in the shipbuilding industry, but can also be applied to other phases of the ship life cycle and even to other industries. By applying the framework, decision-makers can make rational and optimal decisions to be able to invest in energy efficiency measures based on their priorities.
Capacity of the Weakly Absorbent Turbulent Ocean Channel with the Coaxial Double-Position Power Gaussian Vortex
Authors: Yan Qingze , Zhu Yun , Zhang Yixin
Published: October 2021

Turbulence and absorption of seawater are two important factors affecting the signal transmission quality of underwater optical communication link. Here, we study the channel capacity and bit error rate of an underwater extinction communication link with a coaxial double-position power Gaussian vortex carrier based on Rytov approximation theory. The study finds that channel capacity and bit error rate are the nonlinear functions of the dimensionless structural parameter and reach maximum and minimum values at |α| = 1, respectively. The seawater absorption has a great influence on the channel capacity but not bit error rate. The communication link with large receiving aperture, small transmitting beam diameter, long wavelength of light source in a seawater window, and more OAM channels has high channel capacity.
Dynamic Landing Control of a Quadrotor on the Wave Glider
Authors: Lyu Zhilin , Ding Weitao , Sun Xiujun , Sang Hongqiang , Zhou Ying , Yu Peiyuan , Zheng Lijun
Published: October 2021

Aiming at the problems of difficult attitude stabilization, low landing accuracy, large external disturbance and slow dynamic response during the quadrotor dynamic landing on the wave glider, an improved series active disturbance rejection control method for the quadrotor is proposed. The quadrotor controller with inner-loop attitude angular velocity control and outer-loop position control based on the active disturbance rejection controller (ADRC) is designed by analyzing the dynamic model of the quadrotor. A tracking differentiator (TD) is adopted to track the input signal, and an expansive state observer (ESO) is used to estimate the total disturbance. Moreover, a nonlinear law state error feedback (NLSEF) is used to generate the virtual control volume of the system to realize the control of the quadrotor, and the stability of the cascaded self-turbulent controller is verified by Lyapunov’s theory. The simulation verifies that the proposed controller can accurately control the attitude and the position with better anti-interference capability and faster tracking speed. According to the final sea trial, a combination of an active disturbance rejection controller optimized with improved crow search algorithm (ICADRC) and April Tag visual reference system is used to land the quadrotor efficiently and successfully even under the surface float attitude uncertainty.
MAT Loci Play Crucial Roles in Sexual Development but Are Dispensable for Asexual Reproduction and Pathogenicity in Rice Blast Fungus Magnaporthe oryzae
Authors: Wang Jiao-yu , Wang Shi-zhen , Zhang Zhen , Hao Zhong-na , Shi Xiao-xiao , Li Ling , Zhu Xue-ming , Qiu Hai-ping , Chai Rong-yao , Wang Yan-li , Li Lin , Liu Xiao-hong , Feng Xiao-xiao , Sun Guo-chang , Lin Fu-cheng
Published: October 2021

Magnaporthe oryzae, a fungal pathogen that causes rice blast, which is the most destructive disease of rice worldwide, has the potential to perform both asexual and sexual reproduction. MAT loci, consisting of MAT genes, were deemed to determine the mating types of M. oryzae strains. However, investigation was rarely performed on the development and molecular mechanisms of the sexual reproduction of the fungus. In the present work, we analyzed the roles of two MAT loci and five individual MAT genes in the sex determination, sexual development and pathogenicity of M. oryzae. Both of the MAT1-1 and MAT1-2 loci are required for sex determination and the development of sexual structures. MAT1-1-1, MAT1-1-3 and MAT1-2-1 genes are crucial for the formation of perithecium. MAT1-1-2 impacts the generation of asci and ascospores, while MAT1-2-2 is dispensable for sexual development. A GFP fusion experiment indicated that the protein of MAT1-1-3 is distributed in the nucleus. However, all of the MAT loci or MAT genes are dispensable for vegetative growth, asexual reproduction, pathogenicity and pathogenicity-related developments of the fungus, suggesting that sexual reproduction is regulated relatively independently in the development of the fungus. The data and methods of this work may be helpful to further understand the life cycle and the variation of the fungus.
Quantifying the Role of Ground Beetles for the Dispersal of Fusarium and Alternaria Fungi in Agricultural Landscapes
Authors: Heitmann Nadja , Glemnitz Michael , Lentzsch Peter , Platen Ralph , Müller Marina E. H.
Published: October 2021

The spread by arthropods (zoochory) is an essential dispersal mechanism for many microorganisms, like plant pathogens. Carabid beetles are very abundant and mobile ground-dwelling insects. However, their role in the dispersal of economically relevant phytopathogens, like Fusarium and Alternaria fungi is basically unknown. We quantified the total fungal, Fusarium, and Alternaria load of carabid species collected in the transition zones between small water bodies and wheat fields by screening (i) their body surface for fungal propagules with a culture-dependent method and (ii) their entire bodies for fungal DNA with a qPCR approach. The analysis of entire bodies detects fungal DNA in all carabid beetles but Alternaria DNA in 98% of them. We found that 74% of the carabids carried fungal propagules on the body surface, of which only half (49%) carried Fusarium propagules. We identified eight Fusarium and four Alternaria species on the body surface; F. culmorum was dominant. The fungal, Fusarium and Alternaria, load differed significantly between the carabid species and was positively affected by the body size and weight of the carabids. Carabid beetles reveal a remarkable potential to disseminate different fungi. Dispersal by ground-dwelling arthropods could affect the spatial-temporal patterns of plant disease and microorganisms in general.
Make the Best from Comparing Conventional and Islamic Asset Classes: A Design of an All-Seasons Combined Portfolio
Authors: Delle Foglie Andrea , Pola Gianni
Published: October 2021

This paper aims to contribute to the existing literature in portfolio management and strategy by investigating the performance, diversification, and hedging benefits arising from integrating Sharia-compliant stocks into a conventional portfolio. Thus, this paper tests the performance of a Combined Portfolio, resulting from the combination of conventional Islamic instruments, covering different macroeconomic scenarios in the last decade (2010–2020). The strategic asset allocation was designed following the Global Macro Anima (GMA) strategy, solving a risk-parity optimisation problem using a specifically developed MATLAB™ algorithm. The findings will contribute to answering the question related to the possibility of including alternative instruments to increase diversification with hedging benefits by building asset allocations that perform well across different macroeconomic scenarios.
Self-Organising (Kohonen) Maps for the Vietnam Banking Industry
Authors: Ha Man , Gan Christopher , Nguyen Cuong , Anthony Patricia
Published: October 2021

This is the first study to use the self-organisation (Kohonen) map technique, an artificial neural network based on a non-supervised learning algorithm, to categorise Vietnamese banks into super-class groups. Drawing on unbalanced yearly data from 2008 to 2017, this study identifies two super-class groups (one and two). While group one consists of joint stock banks, group two consists of commercial state and joint stock banks. Using the non-structural indicator, the Lerner index, to capture market power, and the data enveloped analysis technique to measure bank performance, our result shows significant differences in Lerner scores (which represent bank market power) of the two groups of banks. Differences in the Lerner scores provide evidence of a group of strong banks that is isolated from other banks. This implies that this strong bank group has the potential to be monopolist and impairs Vietnam’s competitive banking environment. The reason is that group two banks may be more profitable due to greater market power, whereas group one banks may struggle to cut costs to remain viable. These findings provide a better understanding for bank executives, policymakers and regulators of the Vietnam banking industry, and ensure an efficient and competitive Vietnam banking environment.
Optimizing Beef Cow-Calf Grazing across Missouri with an Emphasis on Protecting Ecosystem Services
Authors: Aide Michael , Braden Indi , Murray Susan , Schabbing Collin , Scott Sophia , Siemers Samantha , Svenson Sven , Weathers Julie
Published: October 2021

Soil health is an emerging paradigm for which much research in row crop agriculture has been undertaken. Research involving grazing lands and soil health has not been as active, a feature partially attributed to (i) greater erosional rates in cropland, (ii) loss of soil organic matter and reduced soil structure attributed to annual tillage practices, (iii) cash flow from cropland is easier to visualize than the value-added nature of grazing lands, and (iv) there exists more competitive grant funding sources for croplands. Grazing lands do require soil quality augmentation and investment in soil health to optimize their ecosystem services potential. This manuscript, with an emphasis on beef cattle grazing in the central USA, attempts to survey the literature to (i) identify the influence of grazing on important ecosystem services provided by Mollisols and Alfisols, (ii) develop a listing of soil indicators that may be selected to quantify and credential soil quality, and (iii) develop guidelines that align soil indicators and changes in grazing management to support the restoration of ecosystem services.
Reconstruction of Residential Land Cover and Spatial Analysis of Population in Bursa Region (Turkey) in the Mid-Nineteenth Century
Authors: Ustaoglu Eda , Kabadayı Mustafa Erdem
Published: October 2021

The historic reconstruction of residential land cover is of significance to uncover the human-environment relationship and its changing dynamics. Taking into account the historical census data and cadastral maps of seven villages, this study generated residential land cover maps for the Bursa Region in the 1850s using a model based on natural constraints, land zoning, socio-economic factors and residential suitability. Two different historical reconstructions were generated; one based on a high density residential model and another based on a low density model. The simulated landcover information was used as an ancillary data to redistribute aggregated census counts to fine scale raster cells. Two different statistical models were developed; one based on probability maps and the other applying regression models including Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) models. The regression models were validated with historical census data of the 1840s. From regression models, socio-economic and physical characteristics, accessibility and natural amenities showed significant impacts on the distribution of population. Model validation analysis revealed that GWR is more accurate than OLS models. The generated residential land cover and gridded population datasets can provide a basis for the historical study of population and land use.
Obesity, Lifestyle Behaviors, and Dietary Habits of Saudi Adolescents Living in Riyadh (ATLS-2 Project): Revisited after a Ten-Year Period
Authors: Al-Hazzaa Hazzaa , Albawardi Nada
Published: October 2021

Objective: Undesirable lifestyle behaviors are associated with many adverse health outcomes. This study revisited the lifestyle behaviors, dietary habits, and overweight/obesity status of Saudi adolescents from Riyadh during the year 2019/2020. We report on the rationale, design, and methodology of the current study and provide preliminary findings of the changes that occurred between the two cross-sectional studies within the span of a ten-year period. Methods: A comparison was made between two cross-sectional studies, one conducted in 2009/2010 and the other in 2019/2020, using the same design, methods, and instruments. A multistage stratified cluster random sampling technique was used to select adolescents attending public and private secondary schools. Measurements included demographics, weight, height, waist circumference, physical activity (using valid questionnaire and accelerometer), sedentary time, sleep duration, and dietary habits. Results: The total number of participants was 1262 adolescents, of which 52.4% were male, with a mean (SD) age of 16.4 ± 0.95 years. About 41% of paternal and 39.1% of maternal education levels were university degrees. Over 37% of the families earned more than SAR 20,000/month. Body mass index and waist circumference of males was larger than that of females and the overall prevalence of overweight/obesity was 40.5% with significance (p < 0.001) difference between males (47.3%) and females (32.8%). Between 2009/2010 and 2019/2020 datasets, there were significant changes in age (p < 0.001), waist circumference (p < 0.001), screen time (p < 0.001), moderate-intensity physical activity (p < 0.001), vigorous-intensity physical activity (p < 0.001), total physical activity (p < 0.001), and consumption of breakfast (p = 0.015) and fruits (p = 0.002). Conclusion: The most notable change between the two studies was a significant reduction in the prevalence of physical inactivity among Saudi adolescents, which was due to increased levels of moderate-intensity physical activity among Saudi females, as a result of recent positive sociopolitical changes occurring in the country over the past four years. The findings provided rich information that can be used to explore trends in overweight/obesity, lifestyle behaviors, and dietary habits among Saudi adolescents over the past ten-year period.
Computational Analysis of Mechanical Performance for Composite Polymer Biodegradable Stents
Authors: Donik Žiga , Nečemer Branko , Vesenjak Matej , Glodež Srečko , Kramberger Janez
Published: October 2021

Bioresorbable stents (BRS) represent the latest generation of vascular scaffolds used for minimally invasive interventions. They aim to overcome the shortcomings of established bare-metal stents (BMS) and drug-eluting stents (DES). Recent advances in the field of bioprinting offer the possibility of combining biodegradable polymers to produce a composite BRS. Evaluation of the mechanical performance of the novel composite BRS is the focus of this study, based on the idea that they are a promising solution to improve the strength and flexibility performance of single material BRS. Finite element analysis of stent crimping and expansion was performed. Polylactic acid (PLA) and polycaprolactone (PCL) formed a composite stent divided into four layers, resulting in sixteen unique combinations. A comparison of the mechanical performance of the different composite configurations was performed. The resulting stresses, strains, elastic recoil, and foreshortening were evaluated and compared to existing experimental results. Similar behaviour was observed for material configurations that included at least one PLA layer. A pure PCL stent showed significant elastic recoil and less shortening compared to PLA and composite structures. The volumetric ratio of the materials was found to have a more significant effect on recoil and foreshortening than the arrangement of the material layers. Composite BRS offer the possibility of customising the mechanical behaviour of scaffolds. They also have the potential to support the fabrication of personalised or plaque-specific stents.
Annealing Effect on the Characteristics of Co40Fe40W10B10 Thin Films on Si(100) Substrate
Authors: Liu Wen-Jen , Chang Yung-Huang , Chen Yuan-Tsung , Chang Chun-Yu , Lai Jian-Xin , Lin Shih-Hung , Wu Te-Ho , Chi Po-Wei
Published: October 2021

This research explores the behavior of Co40Fe40W10B10 when it is sputtered onto Si(100) substrates with a thickness (tf) ranging from 10 nm to 100 nm, and then altered by an annealing process at temperatures of 200 °C, 250 °C, 300 °C, and 350 °C, respectively. The crystal structure and grain size of Co40Fe40W10B10 films with different thicknesses and annealing temperatures are observed and estimated by an X-ray diffractometer pattern (XRD) and full-width at half maximum (FWHM). The XRD of annealing Co40Fe40W10B10 films at 200 °C exhibited an amorphous status due to insufficient heating drive force. Moreover, the thicknesses and annealing temperatures of body-centered cubic (BCC) CoFe (110) peaks were detected when annealing at 250 °C with thicknesses ranging from 80 nm to 100 nm, annealing at 300 °C with thicknesses ranging from 50 nm to 100 nm, and annealing at 350 °C with thicknesses ranging from 10 nm to 100 nm. The FWHM of CoFe (110) decreased and the grain size increased when the thickness and annealing temperature increased. The CoFe (110) peak revealed magnetocrystalline anisotropy, which was related to strong low-frequency alternative-current magnetic susceptibility (χac) and induced an increasing trend in saturation magnetization (Ms) as the thickness and annealing temperature increased. The contact angles of all Co40Fe40W10B10 films were less than 90°, indicating the hydrophilic nature of Co40Fe40W10B10 films. Furthermore, the surface energy of Co40Fe40W10B10 presented an increased trend as the thickness and annealing temperature increased. According to the results, the optimal conditions are a thickness of 100 nm and an annealing temperature of 350 °C, owing to high χac, large Ms, and strong adhesion; this indicates that annealing Co40Fe40W10B10 at 350 °C and with a thickness of 100 nm exhibits good thermal stability and can become a free or pinned layer in a magnetic tunneling junction (MTJ) application.
The Use of the ATD Technique to Measure the Gelation Time of Epoxy Resins
Authors: Smoleń Jakub , Olesik Piotr , Gradoń Paweł , Chudy Mateusz , Mendala Bogusław , Kozioł Mateusz
Published: October 2021

In this paper, we investigated the thermodynamics of the resin curing process, when it was a part of composition with graphite powder and cut carbon fibers, to precisely determine the time and temperature of gelation. The material for the research is a set of commercial epoxy resins with a gelation time not exceeding 100 min. The curing process was characterized for the neat resins and for resins with 10% by weight of flake graphite and cut carbon fibers. The results recorded in the analysis of temperature derivative (ATD) method unequivocally showed that the largest first derivative registered during the test is the gel point of the resin. The innovative approach to measuring the gelation time of resins facilitates the measurements while ensuring the stability of the curing process compared to the normative tests that introduce mechanical interaction. In addition, it was found during the research that the introduction of 10% by weight of carbon particles in the form of graphite and cut carbon fibers rather shortens the gelation time and lowers the temperature peak due to the effective absorption and storage of heat from the cross-linking system. The inhibiting (or accelerating) action of fillers is probably dependent on chemical activity of the cross-linking system.
Bioactive Hemp Clothing Modified with Cannabidiol (CBD) Cannabis sativa L. Extract
Authors: Zimniewska Malgorzata , Pawlaczyk Mariola , Romanowska Barbara , Gryszczyńska Agnieszka , Kwiatkowska Edyta , Przybylska Patrycja
Published: October 2021

Hemp fiber variety, Bialobrzeskie, contains phenolic acids in its chemical composition giving it inherent antioxidant and antibacterial activity. The use of this raw material in fabric manufacture allows the creation of functional clothing with a positive effect on human skin. The aim of the study was to develop biologically active functional clothing made of pure industrial hemp raw materials, where cannabidiol (CBD) extract applied on the fabric surface strengthened the fiber bioactivity. The design of the clothing technology was focused on keeping the hemp inherent properties on a steady level and avoiding the use of chemicals in each stage of the value chain from plant cultivation up to garment manufacture. The research covered the evaluation of phenolic acids content and The Ferric Ion Reducing Antioxidant Power FRAP antioxidant activity of the hemp fabric. The hemp fabric enriched with CBD was used for clothing preparation. The human trials covered wearing of the clothing by 15 volunteers for six weeks and evaluation of hemp garment effect on human skin. The skin parameters were tested twice, before and after six weeks of clothing wearing, according to the own methodology that included measurements of skin biophysical properties including tests of skin moisture, transepidermal water loss, and sebum. Also, the effect of the active substances present on the fabrics on the in vitro culture of human keratinocytes was evaluated. Results of the research proved, that the wearing of developed functional hemp clothing with CBD extracts applied on the fabric surface was safe and caused improvement of skin condition, which can have an influence on slowing down of skin aging. The invention covering the pure hemp functional clothing with hybrid bioactivity resulting from the joined activity of fiber and cannabidiol was applied for a patent, Patent Application No: P.438388, 2021.
Investigation of Electrical Properties of the Al/SiO2/n++-Si Resistive Switching Structures by Means of Static, Admittance, and Impedance Spectroscopy Measurements
Authors: Wiśniewski Piotr , Jasiński Jakub , Mazurak Andrzej , Stonio Bartłomiej , Majkusiak Bogdan
Published: October 2021

In this study, the resistive switching phenomenon in Al/SiO2/n++-Si structures is observed and studied by means of DC, small-signal admittance, and complex impedance spectroscopy measurements. Possible transport mechanisms in the high and low resistance states are identified. Based on the results of the applied measurement techniques, an electrical equivalent circuit of the structure is proposed. We discuss the effect of parasitic elements influencing the measurement results and show that a proper model can give useful information about the electrical properties of the device. A good agreement between the characteristics of the proposed equivalent circuit and the experimental data, based on different measurement procedures, confirms the validity of the used methodology and its applicability to the electrical characterization of RRAMs.
Mechanical Reinforcement of Polyamide 6 by Cold Hydrostatic Extrusion
Authors: Skorupska Monika , Kulczyk Mariusz , Przybysz Sylwia , Skiba Jacek , Mizeracki Jan , Ryszkowska Joanna
Published: October 2021

This paper presents the effect of severe plastic deformation obtained using the cold hydrostatic extrusion (HE) method on the mechanical and structural properties of polyamide 6 (PA6). As a result of the plastic strain, a significant increase in ultimate tensile strength and tensile modulus were observed. Tensile strength rose by almost 500%, up to the level of 508 MPa, whereas the tensile modulus rose by about 65%. Flexural modulus increase was also observed to 3230 MPa, i.e., by approx. 160%. As a result of high plastic deformation, the structure of the polyamide 6 changed significantly, as evidenced by its fibrous nature as presented in the results of the scanning electron microscopy inspection (SEM). The surface quality of products investigated was tested using profilometry.
Study on the Melting Temperature of CaF2-CaO-MgO-Al2O3-TiO2 Slag under the Condition of a Fixed Ratio of Titanium and Aluminum in the Steel during the Electroslag Remelting Process
Authors: Hou Dong , Pan Peng , Wang Deyong , Hu Shaoyan , Wang Huihua , Zhang Ganggang
Published: October 2021

During the process of electroslag remelting (ESR) of steel containing titanium and aluminum, the activity ratio between titania and alumina in CaF2-CaO-MgO-Al2O3-TiO2 slag must be fixed in order to guarantee the titanium and aluminum contents in the ESR ingots. Under the condition of fixed activity ratio between titania and alumina in the slag, the melting temperature of slag should be investigated to improve the surface quality of ESR ingots. Therefore, this paper focuses on finding a kind of slag with low melting temperature that can be used for producing steel containing titanium. In the current study, the thermodynamic equilibrium of 3[Ti] + 2(Al2O3) = 4[Al] + 3(TiO2) between SUS321 steel and the two slag systems (CaF2:MgO:CaO:Al2O3:TiO2 = 46:4:25:(25 − x):x and CaF2:MgO:CaO:Al2O3:TiO2 = 46:4:(25 − 0.5 x):(25 − 0.5 x):x) are studied in an electrical resistance furnace based on Factsage software. After obtaining the equilibrium slag with fixed activity ratio between titania and alumina, the melting temperatures of the two slag systems are studied using slag melting experimental measurements and phase diagrams. The results show that the slag systems CaF2:MgO:CaO:Al2O3:TiO2 = 46:4:25:(25 − x):x, which consists of pre-melted slag S0 (CaF2:MgO:CaO:Al2O3 = 46:4:25:25) and pre-melted slag F1 (CaF2:MgO:CaO:TiO2 = 46:4:25:25), can not only control the aluminum and titanium contents in steel, but also have the desired low melting temperature property.
Key-Phase-Free Blade Tip-Timing for Nonstationary Test Conditions: An Improved Algorithm for the Vibration Monitoring of a SAFRAN Turbomachine from the Surveillance 9 International Conference Contest
Authors: Daga Alessandro Paolo , Garibaldi Luigi , He Changbo , Antoni Jerome
Published: October 2021

A turbomachine is a fundamental engineering apparatus meant to transfer energy between a rotor and a fluid. Turbomachines are the core of power generation in many engineering applications such as electric power generation plants, aerospace, marine power, automotive etc. Their relevance makes them both mission critical and safety critical in many fields. To foster reliability and safety, then, continuous monitoring of the rotor is more than desirable. One promising monitoring technique is, with no doubt, the Blade Tip-Timing, which, being simple and non-invasive, can be easily implemented on many different rotors. Blade Tip-Timing is based on the recording of the time of arrival of the blades passing in front of a probe located at a fixed angular position. The non-contact nature of the measurement prevents influences on the measured vibration, that can be recovered for all the blades simultaneously, possibly even online. In this regard, a novel algorithm is presented in this paper for obtaining a good estimate of the vibration of the blades with minimum system complexity (i.e., only one Blade Tip-Timing probe) and minimum computational effort, so to create a simple vibration monitoring system, potentially implementable online. The methodology was tested on a dataset from a SAFRAN turbomachine made available during the Surveillance 9 international conference for a diagnostic contest.
Development of a Magnetic Fluid Heating FEM Simulation Model with Coupled Steady State Magnetic and Transient Thermal Calculation
Authors: Vizjak Jakob , Beković Miloš , Jesenik Marko , Hamler Anton
Published: October 2021

Magnetic fluid hyperthermia has gained much attention in recent years due to its potential in cancer treatment. Magnetic fluid is a colloidal liquid made of nanoscale magnetic particles suspended in a carrier fluid. The properties of a commercial magnetic fluid consisting of maghemite (γ-Fe2O3) particles suspended in mineral oil were used in the scope of our research. The paper deals with a novel approach to the development of a magnetic fluid FEM model of a laboratory setup, with consideration of the electromagnetic steady state and thermal transient calculation soft coupling. Also, adjustment of the mathematical model was added in such a way that it enables a link between the magnetic and thermal calculations in commercial software. The effective anisotropy’s influence on the calculations is considered. The simulation was done for different magnetic field parameters. The initial temperature was also varied so that a direct comparison could be made between the simulation and the measurements. A good indicator of the accuracy of the simulation are the SAR values. The relative differences in SAR values were in the range from 4.2–24.9%. Such a model can be used for assessing the heating performance of a magnetic fluid with selected parameters. It can also be used to search for the optimal parameters required to design an optimal magnetic fluid.
Association of N-acetyltransferases 1 and 2 Polymorphisms with Susceptibility to Head and Neck Cancers—A Meta-Analysis, Meta-Regression, and Trial Sequential Analysis
Authors: Mohammadi Hady , Roochi Mehrnoush Momeni , Sadeghi Masoud , Garajei Ata , Heidar Hosein , Ghaderi Bayazid , Tadakamadla Jyothi , Meybodi Ali Aghaie , Dallband Mohsen , Mostafavi Sarton , Mostafavi Melina , Salehi Mojtaba , Sadeghi-Bahmani Dena , Brand Serge
Published: October 2021

Background and objective:N-acetyltransferases 1 and 2 (NAT1 and NAT2) genes have polymorphisms in accordance with slow and rapid acetylator phenotypes with a role in the development of head and neck cancers (HNCs). Herein, we aimed to evaluate the association of NAT1 and NAT2 polymorphisms with susceptibility to HNCs in an updated meta-analysis. Materials and methods: A search was comprehensively performed in four databases (Web of Science, Scopus, PubMed/Medline, and Cochrane Library until 8 July 2021). The effect sizes, odds ratio (OR) along with 95% confidence interval (CI) were computed. Trial sequential analysis (TSA), publication bias and sensitivity analysis were conducted. Results: Twenty-eight articles including eight studies reporting NAT1 polymorphism and twenty-five studies reporting NAT2 polymorphism were involved in the meta-analysis. The results showed that individuals with slow acetylators of NAT2 polymorphism are at higher risk for HNC OR: 1.22 (95% CI: 1.02, 1.46; p = 0.03). On subgroup analysis, ethnicity, control source, and genotyping methods were found to be significant factors in the association of NAT2 polymorphism with the HNC risk. TSA identified that the amount of information was not large enough and that more studies are needed to establish associations. Conclusions: Slow acetylators in NAT2 polymorphism were related to a high risk of HNC. However, there was no relationship between NAT1 polymorphism and the risk of HNC.
Study on Sulfide Oxidation in a Clay Matrix by the Hyphenated Method
Authors: Zumaquero Eulalia , Gilabert Jessica , Díaz-Canales Eva María , Gazulla María Fernanda , Gómez-Tena María Pilar
Published: October 2021

The requirement of a ceramic product with high technical and aesthetic performance makes it necessary to select and control raw materials to avoid losses caused by low-quality products. Many defects have their origin in impurities present in clay minerals such as sulfides and sulfates. It is important to study the oxidation, decomposition, and pyrolysis reactions that affect these minerals and their dependence on environment conditions (humidity and temperature) during the extraction and beneficiation of clay minerals in an open pit mine. The development of hyphenated techniques coupling mass spectrometry with a thermal analysis instrument provides information that is not available from either technique alone, such as decomposition behavior and the determination of emissions with a lower limit of detection. The evolution of sulfur dioxide from the oxidation of different sulfides provides information on the in situ oxidation and decomposition reactions that happen when a thermal treatment is applied. The results obtained show important differences in the reactions that take place in sulfides when they are stored under different environmental conditions. Specifically, the general tendency is that the sulfurs stored under high relative humidity show a decrease in the intensity of the emission as well as changes in the onset of the peak emission.
Unambiguous NMR Structural Determination of (+)-Catechin—Laccase Dimeric Reaction Products as Potential Markers of Grape and Wine Oxidation
Authors: Deshaies Stacy , le Guernevé Christine , Suc Lucas , Mouls Laetitia , Garcia François , Saucier Cédric
Published: October 2021

(+)-Catechin—laccase oxidation dimeric standards were hemi-synthesized using laccase from Trametes versicolor in a water-ethanol solution at pH 3.6. Eight fractions corresponding to eight potential oxidation dimeric products were detected. The fractions profiles were compared with profiles obtained with two other oxidoreductases: polyphenoloxidase extracted from grapes and laccase from Botrytis cinerea. The profiles were very similar, although some minor differences suggested possible dissimilarities in the reactivity of these enzymes. Five fractions were then isolated and analyzed by 1D and 2D NMR spectroscopy. The addition of traces of cadmium nitrate in the samples solubilized in acetone-d6 led to fully resolved NMR signals of phenolic protons, allowing the unambiguous structural determination of six reaction products, one of the fractions containing two enantiomers. These products can further be used as oxidation markers to investigate their presence and evolution in wine during winemaking and wine ageing.
Marine Brominated Tyrosine Alkaloids as Promising Inhibitors of SARS-CoV-2
Authors: El-Demerdash Amr , Hassan Afnan , Abd El-Aziz Tarek Mohamed , Stockand James D. , Arafa Reem K.
Published: October 2021

There have been more than 150 million confirmed cases of SARS-CoV-2 since the beginning of the pandemic in 2019. By June 2021, the mortality from such infections approached 3.9 million people. Despite the availability of a number of vaccines which provide protection against this virus, the evolution of new viral variants, inconsistent availability of the vaccine around the world, and vaccine hesitancy, in some countries, makes it unreasonable to rely on mass vaccination alone to combat this pandemic. Consequently, much effort is directed to identifying potential antiviral treatments. Marine brominated tyrosine alkaloids are recognized to have antiviral potential. We test here the antiviral capacity of fourteen marine brominated tyrosine alkaloids against five different target proteins from SARS-CoV-2, including main protease (Mpro) (PDB ID: 6lu7), spike glycoprotein (PDB ID: 6VYB), nucleocapsid phosphoprotein (PDB ID: 6VYO), membrane glycoprotein (PDB ID: 6M17), and non-structural protein 10 (nsp10) (PDB ID: 6W4H). These marine alkaloids, particularly the hexabrominated compound, fistularin-3, shows promising docking interactions with predicted binding affinities (S-score = −7.78, −7.65, −6.39, −6.28, −8.84 Kcal/mol) for the main protease (Mpro) (PDB ID: 6lu7), spike glycoprotein (PDB ID: 6VYB), nucleocapsid phosphoprotein (PDB ID: 6VYO), membrane glycoprotein (PDB ID: 6M17), and non-structural protein 10 (nsp10) (PDB ID: 6W4H), respectively, where it forms better interactions with the protein pockets than the native interaction. It also shows promising molecular dynamics, pharmacokinetics, and toxicity profiles. As such, further exploration of the antiviral properties of fistularin-3 against SARS-CoV-2 is merited.
Wound Healing-Promoting and Melanogenesis-Inhibiting Activities of Angelica polymorpha Maxim. Flower Absolute In Vitro and Its Chemical Composition
Authors: Lee Su-Yeon , Won Kyung-Jong , Kim Do-Yoon , Kim Mi-Jung , Won Yu-Rim , Kim Nan-Young , Lee Hwan-Myung
Published: October 2021

Angelica polymorpha Maxim. (APM) is used in traditional medicine to treat chronic gastritis, rheumatic pain, and duodenal bulbar ulcers. However, it is not known whether APM has epidermis-associated biological activities. Here, we investigated the effects of APM flower absolute (APMFAb) on responses associated with skin wound healing and whitening using epidermal cells. APMFAb was obtained by solvent extraction and its composition was analyzed by GC/MS. Water-soluble tetrazolium salt, 5-bromo-2′-deoxyuridine incorporation, Boyden chamber, sprouting, and enzyme-linked immunosorbent assays and immunoblotting were used to examine the effects of APMFAb on HaCaT keratinocytes and B16BL6 melanoma cells. APMFAb contained five compounds and induced keratinocyte migration, proliferation, and type IV collagen synthesis. APMFAb also induced the phosphorylations of ERK1/2, JNK, p38 mitogen-activated protein kinase, and AKT in keratinocytes. In addition, APMFAb decreased serum-induced B16BL6 cell proliferation and inhibited tyrosinase expression, melanin contents, and microphthalmia-associated transcription factor expression in α-melanocyte-stimulating hormone-stimulated B16BL6 cells. These findings demonstrate that APMFAb has beneficial effects on skin wound healing by promoting the proliferation, migration, and collagen synthesis of keratinocytes and on skin whitening by inhibiting melanin synthesis in melanoma cells. Therefore, we suggest that APMFAb has potential use as a wound healing and skin whitening agent.
Mesoporous Zn/MgO Hexagonal Nano-Plates as a Catalyst for Camelina Oil Biodiesel Synthesis
Authors: Man Lai-Fan , Kwong Tsz-Lung , Wong Wing-Tak , Yung Ka-Fu
Published: October 2021

A novel mesoporous Zn/MgO hexagonal-nano-plate catalyst was synthesized by a simple template-free hydrothermal method and applied in the base-catalyzed transesterification of Camelina oil for biodiesel synthesis. The Zn/MgO catalyst calcinated at 873 K exhibited the highest catalytic activity with a yield of 88.7%. This catalytic reaction was performed using 3% w/w of the catalyst with a methanol-to-oil molar ratio of 24:1 at 393 K in 8 h. The excellent catalytic performance is possibly attributed to its favorable textural features with relatively high surface area (69.1 m2 g−1) and appropriate size of the mesopores (10.4 nm). In addition, the as-synthesized catalyst demonstrated a greater basic sites density than single mesoporous MgO, which might have been promoted by the addition of Zn, leading to a synergetic interaction that enhanced its catalytic activity. This catalytic system demonstrated high stability for five catalytic runs and catalytic activity with over 84% yield.
Tip-Viscid Electrohydrodynamic Jet 3D Printing of Composite Osteochondral Scaffold
Authors: Li Kai , Wang Dazhi , Zhang Fangyuan , Wang Xiaoying , Chen Hairong , Yu Aibing , Cui Yuguo , Dong Chuanhe
Published: October 2021

A novel method called tip-viscid electrohydrodynamic jet printing (TVEJ), which produces a viscous needle tip jet, was presented to fabricate a 3D composite osteochondral scaffold with controllability of fiber size and space to promote cartilage regeneration. The tip-viscid process, by harnessing the combined effects of thermal, flow, and electric fields, was first systematically investigated by simulation analysis. The influences of process parameters on printing modes and resolutions were investigated to quantitatively guide the fabrication of various structures. 3D architectures with high aspect ratio and good interlaminar bonding were printed, thanks to the stable fine jet and its predictable viscosity. 3D composite osteochondral scaffolds with controllability of architectural features were fabricated, facilitating ingrowth of cells, and eventually inducing homogeneous cell proliferation. The scaffold’s properties, which included chemical composition, wettability, and durability, were also investigated. Feasibility of the 3D scaffold for cartilage tissue regeneration was also proven by in vitro cellular activities.
High-Uniform and High-Efficient Color Conversion Nanoporous GaN-Based Micro-LED Display with Embedded Quantum Dots
Authors: Huang Yu-Ming , Chen Jo-Hsiang , Liou Yu-Hau , James Singh Konthoujam , Tsai Wei-Cheng , Han Jung , Lin Chun-Jung , Kao Tsung-Sheng , Lin Chien-Chung , Chen Shih-Chen , Kuo Hao-Chung
Published: October 2021

Quantum dot (QD)-based RGB micro-LED technology is seen as one of the most promising approaches towards full color micro-LED displays. In this work, we present a novel nanoporous GaN (NP-GaN) structure that can scatter light and host QDs, as well as a new type of micro-LED array based on an NP-GaN embedded with QDs. Compared to typical QD films, this structure can significantly enhance the light absorption and stability of QDs. As a result, the green and red QDs exhibited light conversion efficiencies of 90.3% and 96.1% respectively, leading to improvements to the luminous uniformity of the green and red subpixels by 90.7% and 91.2% respectively. This study provides a viable pathway to develop high-uniform and high-efficient color conversion micro-LED displays.