bluuebunny/crossref_metadata_2025 huggingface dataset:
Vegetal-FRCM Failure under Partial Interaction Mechanism
Authors: Mendizabal Virginia , Martínez Borja , Mercedes Luis , Bernat-Maso Ernest , Gil Lluis
Published: December 2022

FRCM is a strengthening system based on composite material made of a cementitious matrix and fabrics. This strengthening system has been studied and researched, obtaining analytical predictive models where it is common to assume full composite action between components. Through using non-typical materials for these composites, it has been seen that, in some cases, the previous assumption cannot be taken. In this situation, traditional analytical models such as ACK or tri-linear ones do not offer a reasonable prediction. This work researches the behavior of synthetic and naturally coated vegetal-FRCM with partial interaction through the characterization of the materials through tensile tests. Yarns, meshes and different FRCM coupons were manufactured and mechanically tested using different types of coatings and fabrics. The use of colophony and Arabic gum as natural coatings provided similar mechanical properties to the cotton and hemp yarns and meshes conformed. Partial interaction was found when using epoxy as a natural resin to coat the reinforcement while maintaining the mechanical properties in the same order of magnitude. A new two-stage model is proposed to fit stress–strain mechanical test, and it is reliable and accurate for cotton specimens.
Moringa oleifera Lam. as a Bioflocculant for Harvesting Microalgae Grown on Agricultural Wastewaters for Feed Production
Authors: Konucu Merve , Tekdal Dilek , Eker Develi Elif , Meers Erik , Fernandes de Souza Marcella
Published: December 2022

Harvesting impacts the costs of microalgae production and affects the characteristics of the final product. Therefore, this study evaluated Moringa oleifera seed powder (MP) as a bioflocculant compared to two chemicals (Aluminium Sulphate—AS and Iron Chloride—IC) to harvest a mixed microalgae culture (Chlorella vulgaris and Desmodesmus sp.) grown on digestate. MP was the most stable flocculant but resulted in the lowest harvesting efficiency of 75%, compared to 94% for AS and 100% for IC. Process parameters such as pH, duration of mixing, grinding method for obtaining the powder, and granulometry had no significant effect on the harvesting efficiency of MP, reinforcing that this is a robust flocculant. The use of a water extraction step increased the harvesting efficiency of MP to 91%, albeit with the need for a higher dosage of flocculant. The algae harvested with MP complied with maximum tolerable levels for swine, cattle, and poultry regarding most trace elements. Nevertheless, all algae samples had Fe and Al contents above the recommended levels, possibly due to the entrapment of metal-rich digestate particles. Therefore, more attention should be paid to the final composition of algae when proposing flocculation as a harvesting method for feed production.
Dynamic Analysis and Fault Diagnosis for Gear Transmission of a Vibration Exciter of a Mine-Used Vibrating Screen under Different Conditions
Authors: Cheng Xiaohan , Li Zongwu , Cao Congjie , Wang Yazhou , Ding Nanqin , Wu Guangqiang
Published: December 2022

The helical gear pair of a box-type vibration exciter of a mine-used linear vibrating screen is subjected to complex excitation and prone to broken tooth failures. At present, investigation regarding the difference and particularity between gear transmission in vibrating screens (i.e., vibration machinery) and that in rotating machinery is still a challenge, which is the key to revealing the performance and failure mechanism of gear transmission in the premise of application to vibrating screens. In order to intuitively display the peculiarity of gear transmission on the exciter, an innovative virtual prototype model of a gear pair of a vibrating screen exciter is proposed. This model considers the effects of internal and external excitation, such as the friction and lubrication of the gear, strong alternating load produced by a large eccentric block, the reciprocating motion of the screen body, the large clearance of bearing and so on, and its correctness is verified. Based on the comparison, the inducement for the high fatigue rate of exciter gears is revealed. Models of a vibrating screen’s excitation system with different degrees of broken teeth are also established, and tooth fault features are proposed for fault detection. Sensitive indicators for the degradation degree of tooth damage are put forward, and the monitoring strategy is presented that with the increase of damage degree, the waveform index and pulse index of axial vibration acceleration increase. The analysis results provide powerful support for the optimal design of the vibrating screen’s exciter gears and fault diagnosis.
Development of Electrochemical Biosensor Platforms for Determination of Environmental Viral Structures
Authors: Ekici Rümeysa , Bozdoğan Betül , Denkbaş Emir Baki
Published: December 2022

Infectious diseases caused by viruses (such as influenza, Zika, human immunodeficiency, Ebola, dengue, hepatitis, and COVID-19 virus) are diseases that have been on the agenda of the whole world for the last quarter of a century and have become one of the most important problems for people. Urgent identification of the people infected with a disease will allow these people who have contracted the disease to be treated effectively. In this context, the polymerase-chain-reaction (PCR)-based methods have been the most common and widely used method that responds with sensitivity. However, due to some disadvantages encountered in PCR applications (in particular, the test protocol is comprehensive, not fast in terms of time, not economical, requires user expertise, is not suitable for field/on-site measurements, etc.), a new generation (which can give fast results, are economical, sensitive, suitable for on-site application, etc.) of systems that can provide solutions are needed. On the subject of different test-diagnostic applications used in a large number of test-based analysis methods and techniques, electroanalytical systems have some advantages. Within the scope of this presentation, low-cost, miniaturized electrochemical platforms for surface-printed electrodes by using appropriate biochemical and viral structures of the electrode surfaces decorated with suitable agents are explained. These platforms can be used in the determination of some particular viral proteins for the understanding of viral pathogenic diseases. In this study, a copper-modified graphite electrode was developed and characterized with SEM. Afterwards, an antibody of the N protein of COVID-19 was decorated surrounding this electrode to measure the amount of that protein in the samples. The square wave voltammetry (SWV) technique was used for the electrochemical detection of SARS-CoV-2. When the results of the analyses were examined, the best analytical sensitivity and linearity were obtained by incubating the antibody-modified electrode and virus antigen for 10 min. The measurements showed linearity with a high correlation coefficient (R2 = 0.9917). The detection limit (LOD) was calculated as 508 pg/mL. The measurement limit (LOQ) was calculated as 1.54 ng/mL. With the pencil tip, which is an easily accessible material for the modified electrode system we designed, a very precise measurement was provided for the rapid detection of the N protein of the SARS-CoV-2 virus at very low concentrations.
Progressive Failure Analysis for 5MW-Class Wind Turbine Composite Blades with Debonding Damage based on CZM Method
Authors: Jang Yunjung , Kim Hakgeun , Kang Kiweon
Published: December 2022

Composite wind turbine blades may experience interlaminar damage, including adhesive failure, cracking, and interlaminar fracture failure, from manufacturing or external fatigue load. Among these, the adhesive failure of adhesive joints is critical. Therefore, it is important to identify the failure mechanism in the adhesive joints between the spar cap–shear web and trailing edge of composite blades. We calculated fracture toughness through Mode I, Mode II, and Mixed-mode tests for quantitative analysis of adhesive joints. Then, to select a modeling method for realizing the damage generated in the blade, the method was verified from the specimen level. A damage model was constructed, considering contact conditions of the spar cap–shear web and trailing edge for an NREL 5MW wind turbine blade. Finally, a damage model based on cohesive zone modeling was used to analyze the progressive failure behavior of debonding at adhesive joints according to the external force applied to the blade.
Visual Simulator for Mastering Fundamental Concepts of Machine Learning
Authors: Milakovic Adrian , Draskovic Drazen , Nikolic Bosko
Published: December 2022

Machine learning (ML) has become an increasingly popular choice of scientific research for many students due to its application in various fields. However, students often have difficulty starting with machine learning concepts due to too much focus on programming. Therefore, they are deprived of a more profound knowledge of machine learning concepts. The purpose of this research study was the analysis of introductory courses in machine learning at some of the best-ranked universities in the world and existing software tools used in those courses and designed to assist in learning machine learning concepts. Most university courses are based on the Python programming language and tools realized in this language. Other tools with less focus on programming are quite difficult to master. The research further led to the proposal of a new practical tool that users can use to learn without needing to know any programming language or programming skills. The simulator includes three methods: linear regression, decision trees, and k-nearest neighbors. In the research, several case studies are presented with applications of all realized ML methods based on real problems.
A Multi-Segment Expanded Anchor for Landslide Emergency Management
Authors: Yang Dong , Wang Quancheng , Jiang Zhaoqun , Yang Dongxu
Published: December 2022

Conventional mortar cemented anchors cannot meet the needs for landslide emergency management, as they can withstand loads only after mortar curing for 14–28 days. This study developed a multi-segment expanded anchor (MSEA) that expands using a sliding mechanism and rapidly bears loads using multiple load-bearing bodies by the frictional drag along the perforated wall, and the reaction force of the underreams’ platforms. Field tensile tests without grouting and the secondary tensile tests of six MSEAs, each with a length of 23 m, were carried out. The field tests show that the installed load-bearing bodies expanded steadily when the MSEAs were tensioned without grouting. In hard sandstones, the initial tensile force of each load-bearing body exceeded its design value of 150 kN, and the initial bearing capacity of each MSEA was greater than 300 kN, which exceeded the bearing capacity of the existing anchors regardless of grouting. The secondary tensile tests of the MSEAs were conducted after they were grouted for three days, and their lock-off load was greater than their design value of 600 kN. Based on the elastic mechanics and the stress process of the MSEAs, this study derived the theoretical equations of the ultimate bearing capacity of the MSEAs without grouting. The results calculated using the theoretical equations were roughly consistent with the field test results of the ultimate bearing capacity.
Investigation of Biofabricated Iron Oxide Nanoparticles for Antimicrobial and Anticancer Efficiencies
Authors: Mohandoss Nilavukkarasi , Renganathan Sangeetha , Subramaniyan Vijayakumar , Nagarajan Punitha , Elavarasan Vidhya , Subramaniyan Prathipkumar , Vijayakumar Sekar
Published: December 2022

Capparis zeylanica leaf extract was employed in this work to create iron oxide nanoparticles (α-Fe2O3) using anhydrous ferric chloride. The UV spectrum, XRD, FT-IR, and FE-SEM with EDX methods were used to characterize the fabricated nanoparticles. The iron oxide nanoparticles obtained were spherical in form, with an average crystallite size of 28.17 nm determined by XRD. The agar well diffusion method was used to assess the antimicrobial activity of the α-Fe2O3 nanoparticles created in this study against pathogenic organisms, Gram-negative bacteria (Escherichia coli and Pseudomonas aeroginosa), Gram-positive bacteria (Staphylococcus aureus and Streptococcus pyogenes), and fungi (Candida albicans and Aspergillus niger). Among the pathogens tested, S. pyogenes had the highest zones of inhibition (25 ± 1.26 mm), followed by S. aureus (23 ± 0.8 mm), E. coli (23 ± 2.46 mm), P. aeroginosa (22 ± 1.86 mm), C. albicans (19 ± 2.34 mm) and A. niger (17 ± 3.2 mm). The substance was further tested for anticancer activity against A549 (lung cancer) cells using the MTT assay. The cytotoxic reaction was found to be concentration-dependent. The present study, therefore, came to the conclusion that the bio-effectiveness of the manufactured α-Fe2O3 nanoparticles may result in applications in biomedical domains.
Impact of Carpets on Indoor Air Quality
Authors: Noorian Najafabadi Seyyed Abbas , Sugano Soma , Bluyssen Philomena M.
Published: December 2022

Interest in having a healthy and well-being environment has increased the awareness to improve indoor air quality (IAQ). Building materials influence the contribution of indoor air pollution, so understanding their behaviour on IAQ is essential. Among building materials, carpets cover surfaces of indoor environments and significantly impact IAQ due to their large surface area and multi-layers of materials components. This review aimed to consolidate what is known about how carpet impacts indoor volatile organic compounds (VOCs) concentrations and particulate matter (PM) distributions. The results showed that carpets are not only a source of primary emission but also can ad/absorb VOCs and emit VOCs through secondary emission, sink effects, and transformation reactions. The material composition of each carpet layer, environmental parameters (e.g., humidity, temperature, air velocity), and chamber size influence a carpets’ behaviour. Previous studies on the resuspension of PM from carpets mainly focused on the effects of human activities and humidity. Further studies are needed to enhance knowledge related to carpet behaviours in the indoor environment and on how the common materials of carpets should be designed and sustained to reduce exposure to harmful pollutants indoors while maintaining its benefits.
A Critical Perspective and Inclusive Analysis of Sustainable Road Infrastructure Literature
Authors: Alhjouj Ahmad , Bonoli Alessandra , Zamorano Montserrat
Published: December 2022

In response to the important environmental impacts produced by the road transport network during all its life cycle stages, a set of measurements to include sustainable principles have been identified between 1997–2021, analysed and mapped by applying SciMAT and VOSviewer. The results have shown the predominance of issues which analyse the life cycle assessment of road infrastructures in its both environmental and economic dimension as a way to mitigate their effects on climate change, including the reduction of resources and energy consumption, or of energy consumption and greenhouse gases emissions during the construction and operation stages, respectively. However, the incorporation of the social life cycle assessment dimension, their adaptation to climate change, and the use of smart roads are still in an early stage. Therefore, efforts to include these issues are necessary to address their design according to the resilience concept and ensuring a cleaner and more competitive and climate-neutral Europe.
Evaluation of Adsorbent’s Efficiency by Using Biomarker Approaches in Farm Animals: A Systematic Review
Authors: Freire Lucas Gabriel Dionisio , Ali Sher , de Oliveira Carlos Augusto Fernandes
Published: December 2022

The secondary metabolism of toxigenic fungi can produce mycotoxins, substances that are toxic for both humans and animals. Mycotoxins and their by-products found in various biological tissues are considered biomarkers, and concentrations of these substances are directly proportional to the level of exposure. Mineral adsorbents are substances that may prevent mycotoxin absorption. The aim of this review is to study the feasibility of biomarkers as tools to assess the efficiency of mineral adsorbents against mycotoxin absorption in farm animals. In the systematic review, data from the scientific literature between the 2001 and 2022 were searched based on established criteria selection and eligibility. A total of 22 articles were included. The most used species as animal models were poultry and cattle, while the most common biological samples were milk, serum, and liver. Biomarkers most frequently analyzed were aflatoxin M1 (AFM1) and unmetabolized aflatoxin B1 (AFB1). The most used analytical method was liquid chromatography tandem mass spectrometry. Biomarkers are adequate tools to assess the efficiency of mineral adsorbents against the aflatoxins and deoxynivalenol in farm animals, but further studies are needed to provide reliable biomarkers for other mycotoxins.
Evaluation and Testing System for Automotive LiDAR Sensors
Authors: Gomes Tiago , Roriz Ricardo , Cunha Luís , Ganal Andreas , Soares Narciso , Araújo Teresa , Monteiro João
Published: December 2022

The world is facing a great technological transformation towards fully autonomous vehicles, where optimists predict that by 2030 autonomous vehicles will be sufficiently reliable, affordable, and common to displace most human driving. To cope with these trends, reliable perception systems must enable vehicles to hear and see all their surroundings, with light detection and ranging (LiDAR) sensors being a key instrument for recreating a 3D visualization of the world in real time. However, perception systems must rely on accurate measurements of the environment. Thus, these intelligent sensors must be calibrated and benchmarked before being placed on the market or assembled in a car. This article presents an Evaluation and Testing Platform for Automotive LiDAR sensors, with the main goal of testing both commercially available sensors and new sensor prototypes currently under development in Bosch Car Multimedia Portugal. The testing system can benchmark any LiDAR sensor under different conditions, recreating the expected driving environment in which such devices normally operate. To characterize and validate the sensor under test, the platform evaluates several parameters, such as the field of view (FoV), angular resolution, sensor’s range, etc., based only on the point cloud output. This project is the result of a partnership between the University of Minho and Bosch Car Multimedia Portugal.
A Comparison of the Effects of Binaural Beats of Audible and Inaudible Frequencies on Brainwaves
Authors: Yi Jeong-Han , Kim Kyu-Beom , Kim Ye-Jin , Kim Ji-Su , Kim Hyung-Sik , Choi Mi-Hyun , Chung Soon-Cheol
Published: December 2022

The purpose of this study was to observe the effects of audible and inaudible binaural beat stimuli on alpha power elicitation and compare the differences in triggering effects depending on sound perception. Experiments were conducted on healthy male and female subjects (11 males and 10 females, mean age of 24.6 ± 1.8). To induce alpha waves, audible (250 Hz) or non-audible baseline sound frequencies (18,000 Hz) were presented to the left ear, and a frequency 10 Hz higher than the baseline was presented to the right ear. There were two experimental phases: a rest phase (5 min) in which no stimulus was presented and a stimulation phase (5 min) in which the binaural beat stimulus was presented. An electroencephalogram was measured at a sampling rate of 500 Hz, and relative alpha power values were calculated for each phase in each brain area. In the central regions, both baseline frequencies (audible and inaudible) increased the relative alpha power during the stimulation phase compared with the rest phase, and there were no differences between the two baseline frequencies. In the frontal and central regions, there was a greater increase in relative alpha power in the audible case compared with the inaudible case.
Extraction and Characterization of Fucoidan Derived from Sargassum ilicifolium and Its Biomedical Potential with In Silico Molecular Docking
Authors: Lakshmanan Archana , Balasubramanian Balamuralikrishnan , Maluventhen Viji , Malaisamy Arunkumar , Baskaran Rathinasamy , Liu Wen-Chao , Arumugam Maruthupandian
Published: December 2022

Fucoidan, a polymer derived from seaweed, poses a broad range of biological applications, and its potential medicinal benefits have been widely studied over the past decade. In this study, fucoidan was extracted from marine macroalga Sargassum ilicifolium and its bioactive potential for in silico molecular docking was investigated. Additionally, the computational in silico docking studies were applied on the fucoidan against anticancer and antioxidant target proteins by using Glide ligand docking, Schrodinger software. The FT-IR analysis revealed that fucoidan mainly consisted of the fucose residues (59.1%) and a few monosaccharides, such as uronic acid (11.7%) and sulphate (18.3%). The in vitro tests revealed that fucoidan possessed various antioxidative properties and anticoagulant activities. Fucoidans played an inhibitory role in the colony formation of HepG2 cells. The NADPH oxidase (−7.169 Kcal/mol) and cellular tumor antigen p53 protein (−6.205 Kcal/mol) exhibited the highest antioxidant and anticancer proteins, respectively. Overall, the present study results provide a theoretical foundation for broadening the application of fucoidan from S. ilicifolium as a pharmaceutical ingredient.
Special Issue on Laser Micro/Nano Machining Technology
Authors: Cui Jianlei
Published: December 2022

Through the interaction between lasers and materials, laser micro/nano machining technology changes the materials’ physical state and properties [...]
Special Issue on Advances in Robotics-Based Automation Systems
Authors: Lin Hsiung-Cheng , Bednarz Edward T.
Published: December 2022

Automation systems based on robotics have emerged as a multidisciplinary frontier of science and engineering [...]
Analysis of the Impact of the Coke Manufacturing Process on the Service Life of Siliceous Refractory
Authors: Álvarez López David , García García Manuel
Published: December 2022

In the manufacture of steel and foundry coke, there are a series of circumstances inherent to the process which can affect the life of the refractory material with which the ovens of the batteries are built. This article will deal with the impact of aspects such as sticky ovens and hard pushes on the refractory. For this purpose, data will be obtained from a Didier design coke plant built in the 1970s. In particular, the data comes from two batteries or groups of ovens over a period of two years. Of the types of refractories of which coke batteries are composed, we will only deal with silica material. This is the type of refractory with which the combustion and coking chambers of the ovens are almost exclusively built. Its characteristics and behavior make silica a major player in the service life of a coke battery. Therefore, any aspect of the process that is susceptible to damage during this refractory will have a great impact on the life of the coke manufacturing equipment. The results show that hard pushes and especially sticky ovens damage the silica refractory of the furnaces. Therefore, the proper management of production, focused in minimizing these effects, can contribute to reduce the maintenance cost and prolong the service life of the coke ovens.
Model Test Analysis of Subsurface Cavity and Ground Collapse Due to Broken Pipe Leakage
Authors: Tan Fei , Tan Wufeiyu , Yan Feifei , Qi Xin , Li Qinghua , Hong Zhikai
Published: December 2022

Urban ground collapse is a common geological disaster characterized by its invisible nature, particularly in China, and results in significant socioeconomic losses and even loss of life. Underground pipeline breakage is the most common factor leading to urban ground collapses. Hence, it is essential to study how different types of pipeline breakages initiate the collapse mechanism. In this study, an indoor model test was conducted to directly observe the process of collapse due to broken pipe leakage. A broken pipe was put into a model box and tested by an experimental device. The results showed that among the different pipeline breakage types, vertical damage had the greatest influence on the degree of cavity development and ground collapse. Similarities were observed in the patterns of cavity evolution development and the extent of ground collapse as well, further revealing the significance of the cavity evolution process in predicting ground collapses.
TOF Analysis of Ions Accelerated at High Repetition Rate from Laser-Induced Plasma
Authors: Russell Evan , Istokskaia Valeria , Giuffrida Lorenzo , Levy Yoann , Huynh Jaroslav , Cimrman Martin , Srmž Martin , Margarone Daniele
Published: December 2022

The generation, detection, and quantification of high-energy proton spectra that are produced from laser-target interaction methodologies is a field of increasingly growing popularity over the last 20 years. Generation methods such as target normal sheath acceleration or similar allow for collimated laminar ion beams to be produced in a compact environment through the use of short-burst terawatt lasers and are a growing field of investment. This project details the development and refinement of a python-based code to analyze time-of-flight ion spectroscopy data, with the intent to pinpoint the maximum proton energy within the incident beam to as reliable and accurate a value as possible within a feasible processing time. TOF data for 2.2 × 1016 W/cm2 intensity laser shots incident on a 2 mm Cu target that were gathered from the PERLA 1 kHz laser at the HiLASE center were used as training and testing data with the implementation of basic machine learning techniques to train these methods to the data being used. These datasets were used to ensure more widely applicable functionality, and accurate calculation to within 1% accuracy of an assumed correct value was seen to be consistently achievable for these datasets. This wider functionality indicates a high level of accuracy for previously unseen TOF datasets, regardless of signal/noise levels or dataset size, allowing for free use of the code in the wider field.
Additive Manufacturing of Glass-Ceramic Parts from Recycled Glass Using a Novel Selective Powder Deposition Process
Authors: Vasconcelos João , Sardinha Manuel , Vicente Carlos M. S. , Reis Luís
Published: December 2022

Additive manufacturing technologies have been in continuous growth due to their advantages over traditional manufacturing. The iro3d is a powder deposition machine designed to build metal parts. This research work proposed the adaptation of the iro3d selective powder deposition process to allow the production of glass-ceramic parts using recycled glass powders. Various specimens were produced using different deposition strategies such as build orientation and sintering holding times. Specimens were evaluated in terms of geometric distortions (shrinking and warping) and in terms of mechanical performance (flexural behavior and hardness). Two geometrically complex test parts were also produced to infer the minimum feature size capabilities of the process. The results denoted parts that displayed significant geometrical deviations, which could be correlated with some of the tested parameters. Through the addition of sand to the tested specimens, we demonstrated that distortions could be mitigated with proper control of the powder’s coalescence. In the end, the specimens’ fracture surfaces were examined, and the presence of porosities was correlated with their mechanical properties. The results demonstrated that the iro3d SPD process could be used to produce additively manufactured glass parts.
Effect of High-Mass Fraction of Aluminum on Catalytic Hybrid Rocket Motor
Authors: Tian Hui , Wang Zhongshuo , Zhu Hao , Lu Yudong , Gao Jingfei , Cai Guobiao
Published: December 2022

Catalytic hybrid rocket motors using hydrogen peroxide (HP) are easy and efficient to achieve multiple starts and stops, and hydroxyl-terminated polybutadiene (HTPB) grains are commonly used due to their excellent mechanical properties. The low regression rate of HTPB grains limits the application of hybrid rocket motors. Furthermore, the addition of solid aluminum particles can effectively improve the regression rate and performance of hybrid rocket motors. However, the experimental results of a high mass fraction of aluminum and hydrogen peroxide available at present are not sufficient. In this research, the impact of a high mass fraction of aluminum on the motor performance and ablation rate of nozzles is studied experimentally. A solution of 95% hydrogen peroxide and HTPB with an aluminum additive are adopted as propellants. The variation in the axial regression rate of the grains is obtained by computed tomography (CT) scans and pre-test parameter measurements. The instantaneous regression rate method is adopted to obtain the real-time regression rate of the motor. The surface appearance and composition of the front and the end of the grains after the tests are analyzed by electron microscopy. Carbon ceramic and tungsten-bronze nozzles are used to explore the effect of a high mass fraction of aluminum on nozzle ablation. The experimental results show that the addition of aluminum raises the specific impulse and decreases the optimal oxygen-to-fuel ratio of the propellant combination. The high mass fraction of the aluminum particles has a severe ablative effect on carbon ceramic nozzles, while the effect on tungsten-bronze nozzles is minimal for a hot test lasting four to five seconds. Our results can provide experimental guidance for the application of a high mass fraction of aluminum and hydrogen peroxide hybrid rocket motor.
Influence of Biosynthesized Nanoparticles Addition and Fibre Content on the Mechanical and Moisture Absorption Behaviour of Natural Fibre Composite
Authors: Lakshmaiya Natrayan , Ganesan Velmurugan , Paramasivam Prabhu , Dhanasekaran Seshathiri
Published: December 2022

This study looks at how incorporating nanofiller into sisal/flax-fibre-reinforced epoxy-based hybrid composites affects their mechanical and water absorption properties. The green Al2O3 NPs are generated from neem leaves in a proportion of leaf extract to an acceptable aluminium nitrate combination. Both natural fibres were treated with different proportions of NaOH to eliminate moisture absorption. The following parameters were chosen as essential to achieving the objectives mentioned above: (i) 0, 5, 10, and 15% natural fibre concentrations; (ii) 0, 2, 4, and 6% aluminium powder concentrations; and (iii) 0, 1, 3, and 5% NaOH concentrations. Compression moulding was used to create the hybrid nanocomposites and ASTM standards were used for mechanical testing such as tension, bending, and impact. The findings reveal that combining sisal/flax fibre composites with nanofiller improved the mechanical features of the nanocomposite. The sisal and flax fibre hybridised successfully, with 10% fibres and 4% aluminium filler. The water absorption of the hybrids rose as the fibre weight % increased, and during the next 60 h, all of the specimens achieved equilibrium. The failed samples were examined using scanning electron Microscopic (SEM) images better to understand the composite’s failure in the mechanical experimentations. Al2O3 NPs were confirmed through XRD, UV spectroscope and HPLC analysis. According to the HPLC results, the leaf’s overall concentrations of flavonoids (gallocatechin, carnosic acid, and camellia) are determined to be 0.250 mg/g, 0.264 mg/g, and 0.552 mg/g, respectively. The catechin concentration is higher than the phenolic and caffeic acid levels, which could have resulted in a faster rate of reduction among many of the varying configurations, 4 wt.% nano Al2O3 particle, 10 wt.% flax and sisal fibres, as well as 4 h of NaOH with a 5 wt.% concentration, producing the maximum mechanical properties (59.94 MPa tension, 149.52 Mpa bending, and 37.9 KJ/m2 impact resistance). According to the results, it can be concluded that botanical nutrients may be used effectively in the manufacturing of nanomaterials, which might be used in various therapeutic and nanoscale applications.
An Analysis of Commercial Noni Juice: LC-MS/MS Phenolic Profiles and Cytotoxic Activity
Authors: Johnson Joel B. , Mani Janice S. , Naiker Mani
Published: December 2022

Fermented juice from the noni tree (Morinda citrifolia) is a traditional medicinal product used by South Pacific Islanders to treat a wide range of ailments, including cancer, inflammation and obesity, as well as improving overall wellbeing. Many of its bioactive properties have been suggested to arise from the high antioxidant capacity and phenolic content found in the juice. However, there have been limited investigations into the phenolic profiles of noni juice produced locally in the Pacific. This study aimed to investigate the chemical composition and bioactive properties of noni juice. The first phase of this study used liquid chromatography with tandem mass spectrometry (LC-MS/MS) to characterise the phenolic composition of five brands of commercial noni juice produced in the South Pacific region. A total of 21 phenolic compounds were putatively identified, with the most abundant generally being rutin, 4-hydroxybenzoic acid and gentisic acid. Vastly differing phenolic profiles were found between the noni juice brands. Significant differences were also found in their antioxidant capacities and total phenolic contents. Of the three major phenolic compounds identified, gentisic acid showed the highest antioxidant activity (640% higher than Trolox). Additionally, the noni juice showed no significant anti-acetylcholinesterase activity and no to moderate cytotoxicity against two cancer cell lines (HeLa and HT29). These results indicate that the phytochemical profiles—and hence, the expected bioactive properties—are likely to vary significantly between different noni juice brands. Furthermore, the anti-cancer activity of non-concentrated noni juice appears to be relatively low.
Novel Liposomal Formulation with Azelaic Acid: Preparation, Characterization, and Evaluation of Biological Properties
Authors: Pasca Paula Melania , Miere (Groza) Florina , Antonescu Angela , Fritea Luminita , Banica Florin , Vicas Simona Ioana , Laslo Vasile , Zaha Dana Carmen , Cavalu Simona
Published: December 2022

Azelaic acid (AA), as a natural product, was proven to be effective in targeting multiple causes of acne and related dermatological conditions, as it is well tolerated using different classical formulations (gel, cream, etc.). However, its limited aqueous solubility and inadequate penetration across the stratum corneum might be related to different possible side effects such as itching and burning. The aim of our work was to elaborate a novel liposomal formulation based on azelaic acid, with enhanced biocompatibility, bio-availability, antimicrobial, antigenotoxic, and anti-inflammatory properties. The liposomal formulations were prepared by the lipid film hydration method with different concentrations of azelaic acid (15%, 20%, 25%) and characterized in terms of morphological features, physico-chemical properties, antimicrobial, cytotoxic, and in vitro wound healing effect. Successful encapsulation with 80.42% efficiency, with a size of up to 500 nm and good stability, was achieved, as demonstrated by FTIR spectroscopy (Fourier Transform Infrared Spectroscopy), DLS (dynamic light scattering), and zeta-potential measurements. In terms of antibacterial activity, all the liposomal formulations exhibited a better effect compared to free AA solution against Staphylococcus aureus and Enterococcus faecalis. Cytotoxicity assays and an in vitro “scratch” test performed with normal human dermal fibroblasts revealed an accelerating healing effect, while a comet assay evidenced the protective effect of AA liposomal formulations against hydrogen-peroxide-induced DNA damage in fibroblasts. The optimum formulation in terms of both the antimicrobial and wound healing effect was AALipo20% (liposomes with 20% azelaic acid included).
Problematizing the Adoption of Formal Methods in the 4IR–5IR Transition
Authors: van der Poll John Andrew
Published: December 2022

The adoption of formal methods (FMs) as a software development methodology remains low. Advocates of FMs point to the advantages to be gained by producing highly dependable systems, while critics refer to the steep learning curve required to master the underlying mathematics and logic. The situation was similar for artificial intelligence (AI), but the advent of 4IR–5IR technologies has recently made AI a feasible technology for computing. We believe that the same could hold for FMs. In this article, we considered both the advantages and disadvantages of the use of FMs and unpacked them by problematizing the aspects that need to be considered in the 4IR–5IR worlds to facilitate the use of FMs as a viable software development methodology. We made the case that the 5IR embedding of harmonious collaboration between humans and machines could assist with difficult FM interfaces, similar to how human–computer interaction (HCI) has influenced technical and inflexible systems in the past. Since we view FMs as a technology, we further considered the role to be played by technology adoption, exemplified by the various technology adoption models, e.g., the TOE framework. This article culminates in the formulation of a problematization framework for the adoption of FMs in 4IR–5IR.
Lightning Identification Method Based on Deep Learning
Authors: Qian Zheng , Wang Dongdong , Shi Xiangbo , Yao Jinliang , Hu Lijun , Yang Hao , Ni Yongsen
Published: December 2022

In this study, a deep learning method called Lightning-SN was developed and used for cloud-to-ground (CG) lightning identification. Based on artificial scenarios, this network model selects radar products that exhibit characteristic factors closely related to lightning. Advanced time of arrival and direction lightning positioning data were used as the labeling factors. The Lightning-SN model was constructed based on an encoder–decoder structure with 25 convolutional layers, five pooling layers, five upsampling layers, and a sigmoid activation function layer. Additionally, the maximum pooling index method was adopted in Lightning-SN to avoid characteristic boundary information loss in the pooling process. The gradient harmonizing mechanism was used as the loss function to improve the model performance. The evaluation results showed that the Lightning-SN improved the segmentation accuracy of the CG lightning location compared with the traditional threshold method, according to the 6-minute operating period of the current S-band Doppler radar, exhibiting a better performance in terms of lightning location identification based on high-resolution radar data. The model was applied to the Ningbo area of Zhejiang Province, China. It was applied to the lightning hazard prevention in the hazardous chemical park in Ningbo. The composite reflectivity and radial velocity were the two dominant factors, with a greater influence on the model performance than other factors.
A Descriptive Assessment of Household Air Pollution in Rural Kitchens in Kenya
Authors: Musyoka Dennis , Muindi Kanyiva
Published: December 2022

Efforts to ensure households transition to modern fuels are expected to reduce household air pollution. However, exposure to toxic particles and gases in fuel stacking households remains under-researched. We implemented a household survey to identify household energy sources and assess exposure to particulate matter with diameter of ≤5 microns (PM2.5), ≤10 microns (PM10) and select polluting gases (Sulfur Dioxide (SO2), Total Volatile Organic Compounds (TVOCs), Carbon Dioxide (CO2), Nitrogen Dioxide (NO2), Carbon Monoxide (CO)) in a rural community. Wood was the main cooking fuel in 94.2% (1615/1703) households with fuel stacking reported in 86.1% (1462/1703) of total households. Daily time-weighted average concentrations of PM2.5 and PM10 were beyond World Health Organization (WHO) limits in wood-using households (189.53 (Standard deviation (SD) = 268.80) µg/m3 and 592.38 (SD = 623) µg/m3, respectively) and Liquid Petroleum Gas (LPG) -using households (57.2 (SD = 53.6) µg/m3 and 189.86 (SD = 168) µg/m3, respectively). Only daily average CO and TVOC concentration in wood-using households exceeded recommended levels. Household socio-economic status, education level of the head of household, use of a separate kitchen and household size influenced household energy choices. Rural households using wood as the main cooking fuel are exposed to high levels of particulate matter, carbon monoxide and total volatile organic compounds. LPG-using households may not realize health benefits if stacking with polluting fuels is practiced.
Heteroscedastic Characteristics of Precipitation with Climate Changes in China
Authors: Qian Zhonghua , Wang Luyao , Chen Xin , Zhang Hui , Li Zimeng
Published: December 2022

With global warming, previous studies have found nonuniformity responses of precipitation because of regional differences. However, climate change affects the mean, extreme, and data structure of precipitation. Quantile regression, which can reflect every part of the trends of data, was used to detect responses of each part of precipitation in China. The V2.0 dataset of daily precipitation grid data (0.5° × 0.5°) from 1961 to 2020 in China was used as practical observation data. Daily precipitation in 2015–2100 from the China Model BCC-CSM2-MR of scenarios SSP2-4.5 and SSP5-8.5 were chosen as future climate changes with moderate and high radiative forcing, respectively. On the basis of the sign consistency of the slope coefficients with quantile regression, the results of quantiles q = 0.3, 0.5, 0.7 and 0.9 were selected to represent low, median, high and flood precipitation, respectively. Precipitation in four seasons was separately analyzed to observe seasonal characteristics in China. For the observation data, precipitation had obviously different responses in the low and high percentiles and was present in mainly spring and summer. In spring, in the middle and lower Yangtze Plains, the low and median precipitation increased, whereas the high and flood precipitation significantly decreased. In summer, Heilongjiang Province and northern Inner Mongolia showed decreasing trends in the low quantile and increasing trends in the high quantile, indicating a completely opposite trend adjustment. These regions deserve more attention. However, obviously different responses in low and high percentiles were not so evident in future climate changes. Self-consistency in model data may weaken the heteroscedastic characteristics of precipitation.
A Step to Develop Heat-Health Action Plan: Assessing Heat Waves’ Impacts on Mortality
Authors: Çulpan Hazal Cansu , Şahin Ümit , Can Günay
Published: December 2022

Climate change is one of the biggest health threats facing humanity and can directly affect human health through heat waves. This study aims to evaluate excess deaths during heat waves between the summer months of 2004 and 2017 in Istanbul and to determine a definition of heat waves that can be used in the development of an early warning system, a part of prospective urban heat-health action plans. In this study, heat waves were determined using the Excess Heat Factor, an index based on a three-day-averaged daily mean temperature. The death rates during heat waves and non-heat wave days of the summer months were compared with a Z test of the difference of natural logarithms. Thirty heat waves were recorded in Istanbul during the summer months of 2004–2017. In 67% of the heat waves, the death rate was significantly higher than the reference period and 4281 excess deaths were recorded. The mortality risk was especially higher during heat waves of higher intensity. The study showed an excess risk of mortality during heat waves in Istanbul, and the findings suggest that the Excess Heat Factor could be an appropriate tool for an early warning system in Istanbul.
Effects of Sea-Surface Temperature, Cloud Vertical Structure and Wind Speed on Temperature Change between Hiatus and Post-Hiatus Periods in Tropical Western Pacific
Authors: Su Chien-Han , Kiang Jean-Fu
Published: December 2022

A region in the tropical western Pacific is selected to study the notable change in temperature between the recent warming hiatus period and the post-hiatus period. In total, three probable factors, namely sea-surface temperature (SST), cloud vertical structure (CVS) and wind speed, which may account for the temperature change are found to exhibit noticeable differences between these two periods. A one-dimensional atmospheric radiative transfer model, incorporating convective adjustment and energy exchange with the ocean, is developed to simulate the diurnal pattern of temperature profile under the influence of the three probable factors in the two concerned periods. Virtual profiles of sea-surface temperature, cloud vertical structure and wind speed in both periods are developed from data available in the literature. Diurnal patterns of temperatures near the air–sea interface are computed with the proposed model over a sufficient number of days. The simulated temperatures under different combinations of factors, in either the hiatus or post-hiatus period, are statistically analyzed to gain insights about the separate and combined effects of these three factors on causing climate change.
Estimation of Atmospheric Fossil Fuel CO2 Traced by Δ14C: Current Status and Outlook
Authors: Yu Ming-Yuan , Lin Yu-Chi , Zhang Yan-Lin
Published: December 2022

Fossil fuel carbon dioxide (FFCO2) is a major source of atmospheric greenhouse gases that result in global climate change. Quantification of the atmospheric concentrations and emissions of FFCO2 is of vital importance to understand its environmental process and to formulate and evaluate the efficiency of carbon emission reduction strategies. Focusing on this topic, we summarized the state-of-the-art method to trace FFCO2 using radiocarbon (14C), and reviewed the 14CO2 measurements and the calculated FFCO2 concentrations conducted in the last two decades. With the mapped-out spatial distribution of 14CO2 values, the typical regional distribution patterns and their driving factors are discussed. The global distribution of FFCO2 concentrations is also presented, and the datasets are far fewer than 14CO2 measurements. With the combination of 14C measurements and atmospheric transport models, the FFCO2 concentration and its cross-regional transport can be well interpreted. Recent progress in inverse methods can further constrain emission inventories well, providing an independent verification method for emission control strategies. This article reviewed the latest developments in the estimation of FFCO2 and discussed the urgent requirements for the control of FFCO2 according to the current situation of climate change.