bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Algorithm on Automatic Trimming for Helicopter Rotor Aerodynamic Loads
Authors: Yin Xinfan , Ma Hongxu , Peng Xianmin , Zhang Guichuan , An Honglei , Wang Liangquan
Published: February 2023

In order to simulate the flight state of the helicopter effectively, it is necessary to trim the helicopter during the forward flight in a wind tunnel test. Previously, due to the lack of an internal-control closed loop in the test rig, the helicopter-wind-tunnel-test trimming was carried out manually, with low test efficiency, unstable data quality, and high labor intensity. With the continuous development of computer technology and automatic control technology, the helicopter-wind-tunnel-test trimming technology has been developing in the direction of automation and intelligence. The helicopter wind tunnel test automatic trimming system is a typical multi-input–multi-output (MIMO), strongly coupled, and complex nonlinear system, involving data acquisition and a processing system, rotor control system, tail-supported mechanism control system, wind-tunnel-speed pressure control system, and other subsystems, which is difficult to describe with an accurate mathematical model. Therefore, in order to meet the needs of a 3 m diameter rotor model aerodynamic performance evaluation and noise characteristics research wind tunnel test, an error feedback variable step automatic trimming algorithm is proposed based on the fuzzy-control principle to realize automatic trimming of aerodynamic loads of rotor model in the forward flight state. To verify the effectiveness and reliability of the trimming strategy, a series of wind tunnel tests on a 3 m diameter scaled rotor model of a helicopter were conducted in the FL-17 aeroacoustics wind tunnel of China Aerodynamics Research and Development Center (CARDC) based on the Φ3m tail-supported helicopter rotor model wind tunnel test rig. The wind tunnel test’s results show that the proposed automatic trimming algorithm has the characteristics of fast trimming speed and high efficiency, which can realize the automatic trimming of rotor model aerodynamic loads under different test states in the wind tunnel test effectively and reliably and greatly improve the intelligence level of helicopter wind tunnel test.
Foliar Application of Salicylic Acid Mitigates Saline Stress on Physiology, Production, and Post-Harvest Quality of Hydroponic Japanese Cucumber
Authors: Oliveira Valeska Karolini Nunes , Silva André Alisson Rodrigues da , Lima Geovani Soares de , Soares Lauriane Almeida dos Anjos , Gheyi Hans Raj , de Lacerda Claudivan Feitosa , Vieira de Azevedo Carlos Alberto , Nobre Reginaldo Gomes , Garófalo Chaves Lúcia Helena , Dantas Fernandes Pedro , Antunes de Lima Vera Lúcia
Published: February 2023

Salicylic acid (SA) is a phenolic compound capable of inducing physiological and metabolic changes that enhance the tolerance of plants to saline stress associated with using a hydroponic system and enable the use of saline water in semi-arid regions. In this context, this assay aimed to evaluate the impact of the foliar application of SA on mitigating salt stress effects on Japanese cucumber cultivated in a hydroponic system. The experiment was carried out in a protected ambient (greenhouse), using the Nutrient Film Technique—NFT hydroponic system. A completely randomized design was performed in a 4 × 4 split-plot scheme, with four levels of electrical conductivity of the nutrient solution—ECns (2.1, 3.6, 5.1, and 6.6 dS m−1)—considered as plots and four SA concentrations (0, 1.8, 3.6, and 5.4 mM), regarded as subplots, with four replicates and two plants per plot. An increase in the ECns negatively affected the physiology, production components, and post-harvest quality of cucumber. However, the application of SA to leaves at concentrations between 1.4 and 2.0 mM reduced the deleterious effects of saline stress and promoted an increase in the production of and improvement in the post-harvest quality of cucumber fruits.
Quantitative Description and Classification of Growing Media Particle Morphology through Dynamic Image Analysis
Authors: Durand Stan , Jackson Brian E. , Fonteno William C. , Michel Jean-Charles
Published: February 2023

The physical properties of growing media are dependent on the morphological characteristics of the particles composing them. Thus, their characteristics can be more precisely altered for specific purposes by a better morphological design of materials to optimize the use of raw materials and increase water efficiency. There are many references on the relationship between basic particle size and physical properties, but the arrangement of the particles and the resulting physical properties are also affected by the shape of the particles. Growing media have seldom been characterized by shape criteria and, therefore, their influence remains unknown. A dynamic image analyzer, the QicPic device, was used to assess particle shape and size for a wide diversity of growing media constituents. As well as FeretMAX and ChordMIN diameters describing individual particle length and width, respectively, individual particle shape was analyzed in terms of several descriptors (aspect ratio, circularity, roundness, and convexity). A classification was established to discern different particle shapes and all materials were described accordingly. Correlations between particle morphology descriptors were reported, showing that the greater the particle length, the smaller the width/length ratio, circularity, roundness, and convexity. Circularity, roundness, particle length, and its associated relative span were identified as the most relevant parameters describing materials’ morphology. This work shows a large diversity in particle morphology of growing media constituents, which were categorized into four classes of materials. Three classes were mainly described according to their particle shapes, with a decreasing elongation and an increasing circularity, roundness, and convexity: (1) fine and coarse wood and coir fibers; (2) all Sphagnum white peats, milled or sod; and (3) black peats, sedge peat, coir pith, fresh and composted pine bark, green waste compost, and perlite. A fourth class was represented by coir medium (mixing pith and fibers) and was above all characterized by high diversity in particle length. These findings extend the characterization of the materials for a more thorough evaluation of the links between particle morphology and physical properties.
DIO1 Gene Polymorphism Is Associated with Thyroid Profiles and Reproductive Performance in Dairy Cows
Authors: Kostyunina Olga V. , Mityashova Olga S. , Bardukov Nikolay V. , Aleynikova Olga V. , Lebedeva Irina Y.
Published: February 2023

Thyroid hormones mediate the interaction between the metabolic and reproductive systems, while their metabolism is controlled by different deiodinases. The present study aimed to search for associations of cow genotypes with SNPs in the deiodinase type 1 gene (DIO1) with thyroid profiles and reproductive traits. The blood was sampled from Russian black-and-white cows 2–6 weeks before calving and 1–13 weeks after calving to measure the hormonal levels by ELISA. RT-PCR analysis was performed for known mutations in the bovine DIO1 gene, and a polymorphism at position 13,149 was found. In animals with the CG genotype, the blood concentration of reverse triiodothyronine 6 weeks prepartum was higher and decreased much earlier than in animals with the CC genotype. Furthermore, 1 week after calving, the total triiodothyronine to reverse triiodothyronine ratio in cows with the CG genotype was higher than in cows with the CC genotype. A higher proportion of animals with better values of fertility traits was revealed in the CC group compared to the CG group. Thus, cows with the CC genotype of the DIO1 gene more often have a high reproductive ability, which may be associated with the rT3 profile features during the prepartum and early postpartum periods.
Biochar and Polyhalite Fertilizers Improve Soil’s Biochemical Characteristics and Sunflower (Helianthus annuus L.) Yield
Authors: Aziz Muhammad Abdullah , Wattoo Fahad Masoud , Khan Faheem , Hassan Zeshan , Mahmood Imran , Anwar Adeel , Karim Muhammad Fazal , Akram Muhammad Tahir , Manzoor Rabia , Khan Khalid Saifullah , Majrashi Mosaed A.
Published: February 2023

Biochar (BC) applications have multiple impacts on crops’ nutrient availability, growth and yield depending on the feedstock type and pyrolysis conditions. Pot and field experiments were conducted to examine the effects of biochars (BCs) prepared from three different feedstocks, Acacia modesta wood biochar (AWB), Dalbergia sissoo wood biochar (DWB) and poultry litter biochar (PLB), on soil’s nutrient availability, uptake by wheat (Triticum aestivum) and sunflower (Helianthus annuus) crops and their yield attributes. All BCs were applied at the rate of 10t ha−1 in each treatment in both experiments, and pot and field trials were designed according to a two-factor factorial completely randomized design (CRD) and two-factor factorial randomized complete block design (RCBD), respectively. The concentration of soil NO3-N, NH4-N, Olsen P and extractable K increased by 98.5, 296, 228 and 47%, respectively, in the pot experiment with the application of PLB+polyhalite (PH) treatments. Similarly, in field experiments, NO3-N, NH4-N and Olsen P contents increased by 91, 268 and 156% under the PLB+PH treatment, respectively. However, in both experiments, soil’s microbial biomass phosphorus (MBP) was significantly higher after AWB+PH treatment, and the increments were 127 and 109% while microbial biomass nitrogen (MBN) contents were 16 and 14% higher than the control under DWB+PH and AWB+PH treatments, respectively, in the field experiment. Similarly, combined PLB+PH increased the total organic carbon (TOC) of soil by 193%. Moreover, PLB+PH co-applications with PH significantly increased sunflower grain yields by up to 58% and the harvest index by 45%. Overall, no negative impact with respect to BCs was observed on the soil’s nutrient content and plant growth. Hence, for immediate crop benefits and soil health, using nutrient biochar (PLB) alone or in combination with chemical fertilizers is recommended.
Carriage of Extended Spectrum Beta Lactamase-Producing Escherichia coli: Prevalence and Factors Associated with Fecal Colonization of Dogs from a Pet Clinic in Lower Saxony, Germany
Authors: Werhahn Beining Marco , Hartmann Maria , Luebke-Becker Antina , Guenther Sebastian , Schaufler Katharina , Hille Katja , Kreienbrock Lothar
Published: February 2023

Extended spectrum beta-lactamase (ESBL)-producing Escherichia coli are an emerging problem in veterinary and human medicine. Our study concentrated on the estimation of the prevalence and factors associated with the carriage of ESBL-producing E. coli in dogs who visited a veterinary clinic in northern Germany in 2017. For this reason, 1000 patients (healthy and sick dogs) were tested, resulting in 1000 samples originating from rectal swabs. Additional data were collected using a self-reported questionnaire that was completed by the dog owner. Factors associated with ESBL carriage were considered for further modeling if p < 0.05 using a two-sided Fisher test. Using a backward elimination procedure, the variables for the final multivariable logistic regression model were identified. In total, 8.9% of the dogs tested were positive for carriage of ESBL-producing E. coli. Seven factors were associated with the colonization of dogs with ESBL-E. coli within the multivariable model, namely husbandry system (p = 0.0019, OR = 3.00; 95% CI: 1.50–6.00), contact with puppies (p = 0.0044, OR = 2.43; 95% CI: 1.32–4.46), feeding of raw meat (p = 0.011, OR = 2.28; 95% CI: 1.21–4.31), food residues (p = 0.0151, OR = 2.31; 95% CI: 1.18–4.53) and food supplements (p = 0.0487, OR = 0.426; 95% CI: 0.18–0.96), and antibiotic treatments of dogs (p = 0.0005, OR = 3.030; 95% CI: 1.62–5.68) or owners (p = 0.041, OR = 2.74; 95% CI: 1.04–7.19) prior to the study. These factors refer to the animals themselves as well as to the owners and their habits or medical treatments. Although the causality and direction of transmission from owners to their dogs cannot be proven, the factor of antibiotic treatment of the owner is clearly associated with the dog’s status.
Evaluation of Single Nucleotide Polymorphisms (SNPs) Associated with Genetic Resistance to Bovine Paratuberculosis in Marchigiana Beef Cattle, an Italian Native Breed
Authors: Mazzone Piera , Di Paolo Antonella , Petrucci Linda , Torricelli Martina , Corneli Sara , Sebastiani Carla , Ciullo Marcella , Sebastianelli Martina , Costarelli Silva , Scoccia Eleonora , Sbarra Fiorella , Gabbianelli Federica , Chillemi Giovanni , Valentini Alessio , Pezzotti Giovanni , Biagetti Massimo
Published: February 2023

Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of paratuberculosis (PTB), a widespread chronic enteritis of ruminants. The progression of the infection depends on the containment action of innate and cell-mediated immunity (CMI), and it is related to environmental and genetic factors. In particular, PTB susceptibility seems to be associated with specific genes coding for immune regulators involved in the cell-mediated response during the infection. The aim of this preliminary study was to verify, in Italian beef cattle, an association between MAP infectious status and the presence of single nucleotide polymorphisms (SNPs) in candidate genes. To the best of our knowledge, this is the first investigation conducted on a native beef cattle breed, known as Marchigiana, reared in Central Italy. The present research, based on a longitudinal study, aimed to identify and correlate phenotypic and genetic profiles characteristic of the subjects potentially able to contrast or contain PTB. In a MAP-infected herd, ELISA, IFN-γ tests, qPCR, and cultures were performed at a follow-up, occurring within a period ranging from three to six years, to evaluate the individual state of infection. Animals testing positive for at least one test were considered infected. DNA samples of 112 bovines, with known MAP statuses, were analyzed to verify an association with SNPs in the genes encoding gamma-interferon (BoIFNG), interleukin receptor 10 (IL10RA), interleukin receptor 12 (IL12RB2), and toll-like receptors (TLR1, TLR2, TLR4). Regarding statistical analysis, the differences among target genes and pairs of alleles in the analyzed groups of animals, were evaluated at a significance level of p < 0.05. For IL10RA and for IL12RB2 genes, relevant differences in genotypic frequencies among the considered cattle groups were observed. For all candidate genes studied in this investigation, SNP genotypes already associated with PTB resistance were found more frequently in our population, suggesting potential resistance traits in the Marchigiana breed.
Prevalence and Features of Incidental Findings in Veterinary Computed Tomography: A Single-Center Six-Years’ Experience
Authors: Caspanello Tiziana , Masucci Marisa , Iannelli Diego , Iannelli Nicola Maria , De Majo Massimo
Published: February 2023

Computed tomography (CT) is an advanced imaging technique that may lead to detect “incidentalomas”, unexpected asymptomatic lesions found during unrelated examinations. Their clinical meaning and management are not clear for veterinarians, who risk unnecessary investigations that harm the patients. This study is a retrospective analysis that aims to investigate incidentalomas in CT exams and to describe their prevalence, location, types and follow-up, their correlations and associations with the species, breed, sex, and age of patients examined and with the kind and number of sites scanned. The reports of 561 CT scans performed in 512 dogs and 49 cats in a veterinary facility over six years were reviewed and compared to the clinical records of the patients. Eighty incidentalomas were found in 57 dogs and four cats. A significant positive correlation was found in dogs between age and the prevalence of incidentalomas. In dogs, the prevalence of incidentalomas was significantly higher in Boxers and in neck, thoracic, and abdominal scans. Spinal incidentalomas were the most common typologies in dogs. This study can represent a tool that allows clinicians to acquire greater awareness about incidentalomas and to carry out the evidence-based clinical management of them.
High Brightness Diode Laser Based on V-Shaped External Cavity and Beam-Waist Splitting Polarization Combining
Authors: Zhao Yufei , Tong Cunzhu , Wei Zhipeng , Feng Jian , Wang Lijie
Published: February 2023

A beam combining method to improve the brightness of diode lasers is proposed based on a V-shaped external cavity spectral beam and beam-waist splitting polarization combination. This design has the outstanding advantages of improving the beam quality, brightness, and versatility of the diode laser. Specifically, an output power over 16W with M2 factors of 1.79 × 3.92 (Beam Parameter Product BPP = 0.55 × 1.22 mm mrad) at 40 A in the fast and slow axis is demonstrated for a commercial standard cm-bar. Furthermore, the slow axis M2 of the combined laser is improved by 56% compared with that of a single emitter. Additionally, the brightness of 262 MW·cm−2·sr−1, 136% higher than that of spectral beam combining without using beam-waist splitting polarization, was realized.
The Influence of Interface Roughness on the Vibration Reduction Characteristics of an Under-Platform Damper
Authors: Hu Shijie , She Houxin , Yang Guang , Zang Chaoping , Li Chaofeng
Published: February 2023

Analysis of the vibration reduction characteristics of shock absorbers is crucial for engines. In this study, the fractal theory was applied to the contact surface of an under-platform damper (UPD), and the influence of the excitation force in the same and opposite directions on the roughness of the contact surface was studied. First, based on fractal geometry theory (FGT), the roughness characterization method of a UPD contact surface was proposed. Then, the friction mechanical model of the rough contact surface was established by combining it with a 3D contact mechanical model. Furthermore, a finite element dynamic model of a blade with a UPD structure was set up. Next, the harmonic balance method was used to calculate the nonlinear response characteristics of a blade under different levels of contact surface roughness. Finally, the influence of the contact surface roughness on the vibration reduction ability of a UPD under different excitation modes was analyzed. According to the simulation results, as the contact surface became rougher, the vibration suppression ability of the UPD on the blade became stronger and stronger. With the change in the centrifugal force of the UPD and the amplitude of the same/reverse excitation force, the influencing law of the contact surface roughness on the vibration suppression ability of the UPD remained unchanged, indicating that the rougher the contact surface roughness, the better the vibration suppression effect.
Improved Surrounding Rock Classification Method for the Middle Rock Pillar of a Small Clear-Distance Tunnel
Authors: Wang Jianxiu , Cao Ansheng , Wu Zhao , Liu Xuezeng , Li Zonghai , Lin Lihua , Liu Xiaotian , Li Huboqiang , Sun Yuanwei
Published: February 2023

In tunnel design and construction, proper and accurate classification of rock surrounding tunnels is needed to ensure tunnel construction safety, guarantee construction quality, and reduce project costs. With rapid urbanization, numerous small clear-distance tunnels have been constructed in dense urban road networks. Compared with ordinarily separated tunnels, the construction scale and difficulty of small clear-distance tunnels are greater, and the requirements for the classification of rock surrounding tunnels are accordingly higher. A small clear-distance tunnel in an urban super large and complex underground interchange hub of the Xiamen Haicang Evacuation Channel was selected as the background, and the classification method of the middle rock pillar in a small clear-distance tunnel is presented based on the general classification standard of surrounding rocks. Based on the geometric, physical, and mechanical factors of the middle rock pillar, six indices affecting the stability and quality of the middle rock pillar were selected, and the classification index system of the middle rock pillar was established from the two dimensions of the basic and auxiliary indices. The basic and auxiliary indices were scored using the scoring method, and the different grades of the middle rock pillar were divided according to different scores. The middle rock pillar classification standard was applied to the quality assessment of the middle rock pillar, which provided a basis for the on-site assessment of the quality of the middle rock pillar and proved the accuracy and superiority of the improved classification standard. The newly established classification standard can provide a reference for selecting the correct construction method and supporting structure type for small clear-distance tunnels.
The Concurrent Validity and Test-Retest Reliability of Possible Remote Assessments for Measuring Countermovement Jump: My Jump 2, HomeCourt & Takei Vertical Jump Meter
Authors: Chow Gary Chi-Ching , Kong Yu-Hin , Pun Wai-Yan
Published: February 2023

Mobile applications and portable assessments make remote self-assessment of the countermovement jump (CMJ) test possible. This study aimed to investigate the concurrent validity and test–retest reliability of three portable measurement systems for CMJ. Thirty physically active college students visited the laboratory twice, with two days in between, and performed three jumps each day. All jumps were recorded by My Jump 2, HomeCourt, and the Takei Vertical Jump Meter (TVJM) simultaneously. Results indicated significant differences among the three systems (p < 0.01). HomeCourt tended to present the highest jump height mean value (46.10 ± 7.57 cm) compared with TVJM (42.02 ± 8.11 cm) and My Jump 2 (40.85 ± 7.86 cm). High concurrent validities among assessments were found (r = 0.85–0.93). Good to excellent reliability of jump assessments was demonstrated (ICC3,1 = 0.80–0.96). Reliable coefficients of variation were shown in all measurements (2.58–5.92%). Significant differences were revealed among the three apparatuses while they demonstrated high intra-device test–retest reliability. TVJM was the most reliable, and average jump heights were recommended for analysis.
Urban Congestion Avoidance Methodology Based on Vehicular Traffic Thresholding
Authors: Stan Ioan , Ghere Daniel Alexandru , Dan Paula Iarina , Potolea Rodica
Published: February 2023

Vehicular traffic in urban areas faces congestion challenges that negatively impact our lives. The infrastructure associated with intelligent transportation systems provides means for addressing the associated challenges in urban areas. This study proposes an effective and scalable vehicular traffic congestion avoidance methodology. It introduces a traffic thresholding mechanism to predict and avoid vehicular traffic congestion during route computation. Our methodology was evaluated and validated by employing four road network topologies, three vehicular traffic density levels and various traffic light configurations, resulting in 26 urban traffic scenarios. Using our approach, the number of vehicles that can run in free flow can be increased by up to 200%, whereas for traffic congestion scenarios, the time spent in traffic may be reduced by up to 69% and CO2 emissions by up to 61%. To the best of our knowledge, in the vehicular traffic flow prediction domain, this is the first approach that covers a set of road network topologies and a large and representative set of scenarios for simulated urban traffic congestion testing. Moreover, the comparative analysis with different other solutions in the domain, showed that we obtained the best driving time and CO2 emission reduction.
Phase I Analysis of Nonlinear Profiles Using Anomaly Detection Techniques
Authors: Cheng Chuen-Sheng , Chen Pei-Wen , Wu Yu-Tang
Published: February 2023

In various industries, the process or product quality is evaluated by a functional relationship between a dependent variable y and one or a few input variables x, expressed as y=fx. This relationship is called a profile in the literature. Recently, profile monitoring has received a lot of research attention. In this study, we formulated profile monitoring as an anomaly-detection problem and proposed an outlier-detection procedure for phase I nonlinear profile analysis. The developed procedure consists of three key processes. First, we obtained smoothed nonlinear profiles using the spline smoothing method. Second, we proposed a method for estimating the proportion of outliers in the dataset. A distance-based decision function was developed to identify potential outliers and provide a rough estimate of the contamination rate. Finally, PCA was used as a dimensionality reduction method. An outlier-detection algorithm was then employed to identify outlying profiles based on the estimated contamination rate. The algorithms considered in this study included Local Outlier Factor (LOF), Elliptic Envelope (EE), and Isolation Forest (IF). The proposed procedure was evaluated using a nonlinear profile that has been studied by various researchers. We compared various competing methods based on commonly used metrics such as type I error, type II error, and F2 score. Based on the evaluation metrics, our experimental results indicate that the performance of the proposed method is better than other existing methods. When considering the smallest and hardest-to-detect variation, the LOF algorithm, with the contamination rate determined by the method proposed in this study, achieved type I errors, type II errors, and F2 scores of 0.049, 0.001, and 0.951, respectively, while the performance metrics of the current best method were 0.081, 0.015, and 0.899, respectively.
Health Risk Assessment of Metals in African Aphrodisiacs: A Case Study of Aqueous Concoctions from Johannesburg and Durban Herbal Markets, South Africa
Authors: Dube Siphesihle , Makhubela Nkosinathi , Madikizela Lawrence Mzukisi , Mongalo Nkoana Ishmael , Pakade Vusumzi Emmanuel , Maseko Bethusile Rejoice , Ncube Somandla
Published: February 2023

Consumption of aphrodisiacs is a common practice in South Africa. Hence, determining the levels of trace metals as potential pollutants is necessary to protect consumers’ health. The current study reports a health risk assessment due to metals in aphrodisiacs collected from herbal markets in Johannesburg and Durban, South Africa. Samples were digested using microwave-assisted digestion followed by inductively coupled plasma-optical emission spectrometry analysis. The results showed that the concentrations of common metals (Na, K, Mg, and Ca) were within the guideline limits for human consumption, while the trace metals (Ni, Cr, Co, As, Cd, and Pb) were above the limits, recording values of 0.132–0.268, 0.209–0.308, 0.224–0.405, 0.0884–0.230, 0.0402–1.11, and 0.146–0.207 mg L−1, respectively. The source of the trace metals was traced to the tap water probably collected from dilapidated buildings where the water systems are ailing. A strong correlation for metals with similar sources was observed, notably for Pb and Cd that leach from water pipes. The aphrodisiacs had low consumption rates, and the health risk assessment gave a hazard quotient of 0.225 as a total for all studied metals. The group of aphrodisiacs investigated in the current study therefore poses minimal health risks and can be consumed without fear of metal contamination. More inclusive studies are, however, needed to have a better understanding of aphrodisiacs with the aim of potentially commercializing them like the other commercialized herbal concoctions currently distributed in South African markets and pharmacies.
Stability Analysis of Surrounding Rock of an Underground Cavern Group and Excavation Scheme Optimization: Based on an Optimized DDARF Method
Authors: Ma Hai-Ping , Daud Nik Norsyahariati Nik , Yusof Zainuddin Md , Yaacob Wan Zuhairi , He Hu-Jun
Published: February 2023

The surrounding rock stability of an underground cavern group is an important issue in the process of cavern excavation, which has the characteristics of large displacement, discontinuity and uneven deformation, so the calculation and analysis are very complicated. The optimized discontinuous deformation analysis for rock failure method was adopted to analyze the stability of the surrounding rock of a real underground engineering cavern group under different excavation schemes. The cracking process of surrounding rock under different excavation schemes, the depth of crack expansion and the vertical displacement of the arch and bottom floor were obtained, and the following conclusions are drawn: (a) After the completion of the excavation, the stability problems mainly appeared in the surrounding rocks of the arch, left wall, right wall and bottom floor of the main powerhouse, in the surrounding rocks of the arch, left wall and bottom floor of the main transformer chamber and in the surrounding rocks of the arch, right wall and bottom floor of the tailrace surge tank. (b) Fault f2 has an influence on the stability of the surrounding rock of the tailrace surge tank, while fault f1 has no influence on the stability of the cave group. (c) The scheme of simultaneous excavation of three caverns shows the advantages in the crack propagation depth of surrounding rock and vertical displacements of caverns.
HPLC Analysis of Polyphenolic Compounds in Lysimachia nummularia L. and Comparative Determination of Antioxidant Capacity
Authors: Suciu Felicia , Stoicescu Iuliana , Lupu Elena , Musuc Adina , Popescu Antoanela , Mititelu Magdalena , Roșca Adrian , Dumitrescu Denisa-Elena , Badea Florin , Caraiane Aureliana , Badea Victoria
Published: February 2023

Lysimachia nummularia L. is a perennial herbaceous plant rich in bioactive compounds, which can be utilized for medicinal purposes. The present work aims to analyze the phenolic compounds from different parts of the Lysimachia nummularia L. plant using the HPLC technique: Lysimachiae radix (the root part), Lysimachiae herba (the aerial part), Lysimachiae flores (flowers). In order to determine the phenolic compounds, extraction from the three categories of vegetable products was performed with ethanol 70% (v/v) using three extraction methods: (i) Soxhlet extraction, (ii) maceration and (iii) ultrasonic-assisted extraction. The content of polyphenols was determined by the Folin–Ciocalteu method, and the antioxidant activity was evaluated by the DPPH, ABTS, FRAP and CUPRAC methods. The antioxidant activity was correlated with the content of phenolic compounds in the analyzed extracts. The following phenolic compounds were separated, identified and quantified: 3-O-methylgallic, gallic, ferulic, caffeic, chlorogenic, p-coumaric acids and trans-resveratrol. According to the experimental data, the highest content of total polyphenols was observed in the hydroethanolic extract from Lysimachiae flores (22.10 ± 1.48 mg gallic acid/g), which also presented remarkable antioxidant activity.
Bearing Fault Diagnostics Based on the Square of the Amplitude Gains Method
Authors: Grądzki Rafał , Bartoszewicz Błażej , Martínez José Emiliano
Published: February 2023

The article presents an adaptation of a parametric diagnostic method based on the square of the amplitude gains model, which was tested in experimental studies on bearing damage detection (outer race, inner race, bearing balls damage). The described method is based on the shaft displacement signal analysis, which is affected by vibrations coming from the bearings. The diagnostic model’s parameters are determined by processing the signal from the time domain to the frequency domain in a few steps. Firstly, the recorded signal is divided into two observation periods, next the analytical autocorrelation functions are determined and approximated by a polynomial. Then, the diagnostic thresholds are adopted, and the model parameters are converted into damage maps that are easy to interpret and assess the technical condition of the bearings. The presented method shows the technical condition of bearings in a qualitative way. Depending on the received color damage maps, it is possible to determine their level of wear. Green and blue indicate poor wear or no damage, red indicates increased wear, and black clearly indicates a damaged bearing.
Designing a Vertical Handover Algorithm for Security-Constrained Applications
Authors: Khattab Omar , Khan Murad , Alothman Basil
Published: February 2023

In heterogeneous networks (HetNets), the vertical handover (VHO) is an essential process for mobile users (MUs) aiming to secure ubiquitous connectivity and maintain the highest quality of service (QoS) across various types of radio access technology (RAT), such as wireless fidelity (Wi-Fi), the global system for mobile communication (GSM), and the universal mobile telecommunications system (UMTS). In the literature, many recent VHO research works have been proposed in which a number of critical issues still arise when performing seamless vertical handover, including VHO packet loss, VHO delay, and VHO throughput. Moreover, the security aspect of triggering VHO has not been carefully considered, particularly when an MU intends to use a payment application. In this paper, we present a comprehensive performance evaluation for a new secure VHO algorithm, taking into account all the above issues, for co-located Wi-Fi and UMTS networks. The simulation results are compared with the media independent handover (MIH) IEEE 802.21 standard, which facilitates the seamless transfer of connection among heterogeneous networks. We show that the proposed algorithm outperforms the MIH standard in terms of VHO delay, VHO packet loss, and VHO throughput in providing uninterrupted connection to security-constrained applications.
A Time-Domain Planning Method for Surface Rescue Process of Amphibious Aircraft for Medium/Distant Maritime Rescue
Authors: Yang Lu , Yin Rong , Xue Yuanbo , Tian Yongliang , Liu Hu
Published: February 2023

Medium/distant maritime rescue is significantly important in the development of maritime business. For typical medium/distant maritime rescue, the range limitation of helicopters and many difficulties between helicopter and ship cooperation lead to unsatisfactory rescue results. Compared to helicopters and ships, amphibious aircrafts could effectively solve the problems faced by helicopters and ships and meet the medium/distant maritime rescue demands with their long cruise range, high speed, high rescue capability and surface landing capability. Therefore, a time-domain planning method (TPM) based on the k-means* clustering algorithm and the genetic algorithm* is proposed in this study for the surface rescue process (SRP) of amphibious aircrafts in medium/distant maritime rescue. To simulate the SRP of amphibious aircrafts, an agent-based simulation environment of medium/distant maritime rescue was constructed based on the Python platform. Finally, a case study was carried out to verify its effectiveness and applicability. The results show that the TPM exhibits satisfactory rescue results for the SRP of the amphibious aircraft and that less than 1 h of delay time is recommended for the amphibious aircraft to rescue the persons in distress by using TPM.
Identification of Large-Scale Travelling Ionospheric Disturbances (LSTIDs) Based on Digisonde Observations
Authors: Tsagouri Ioanna , Belehaki Anna , Koutroumbas Konstantinos , Tziotziou Konstantinos , Herekakis Themistocles
Published: February 2023

In this paper we analyze Digisonde observations obtained in the European region to specify the effects of large-scale travelling ionospheric disturbances (LSTIDs) on the ionospheric characteristics that define the conditions in the bottomside ionosphere. While this type of disturbances affects all frequency ranges in the F region, the most pronounced effect is detected in the foF2 critical frequency, where the density is the highest. During LSTID activity, a significant uplifting of the F2 layer is observed to accompany an oscillation pattern in the foF2. Concurrent variations in the height of the peak electron density hmF2 and the corresponding scale height, Hm are also observed. These findings are used to propose a new methodology for the identification of LSTIDs, comprising a combination of different criteria. The efficiency of the proposed methodology is tested at middle latitudes during geomagnetically quiet and disturbed intervals as well as during time periods of lower atmosphere forcing affecting the ionosphere.
Analysis of Large-Scale Environmental Features during Maximum Intensity of Tropical Cyclones Using Reanalysis Data
Authors: Gorja Mohan Murali Krishna , Gulakaram Venkata Sai , Vissa Naresh Krishna , Viswanadhapalli Yesubabu , Tyagi Bhishma
Published: February 2023

The present study investigates the variation in large-scale environments during the maximum intensity of tropical cyclones (TCs) formed in the Bay of Bengal. TC tracks are classified into four groups based on their direction of movement using the k-means clustering technique. Results from the pressure level and azimuthal-averaged radial-height wind fields near the vortex centre show weak deep layer wind shear (WS) and abundant moisture in all clusters. However, large-scale environmental differences in the northwest quadrant are identified with a contrasting combination of WS and humid environment between clusters. The composites of OLR are also analyzed during maximum intensities of TCs. Results show that anomalous high OLR in the west–northwest direction from the vortex centre, along with the low OLR around the vortex centre, signify the formation of a strong OLR dipole during TC peak intensity. Furthermore, OLR dipole metrics, such as magnitude, orientation, and distance, are observed by having mean of 235 Wm−2, 147, and 1782 km along with standard deviation of 14 Wm−2, 34°, and 492 km, respectively. The identified large-scale environmental fields from this study could provide valuable insights for predicting the intensity and movement of TCs.
Spatiotemporal Evolution and Drivers of the Four Ionospheric Storms over the American Sector during the August 2018 Geomagnetic Storm
Authors: Zhai Changzhi , Chen Yutian , Cheng Xiaoyun , Yin Xunzhe
Published: February 2023

The spatiotemporal variations and mechanisms of the ionospheric storms over the American sector during the August 2018 geomagnetic storm are investigated. One positive and one negative ionospheric storm occurred in North America and two positive storms were observed in South America. The ionosphere showed prominent hemispheric asymmetries during the four storms. The maximum VTEC (vertical total electron content) variation was more than 15 TECU during the positive storms and about −10 during the negative storm. The GUVI (Global Ultraviolet Imager) oxygen (O) to nitrogen (N2) column density ratio (∑O/N2) and SuperDARN (Super Dual Auroral Radar Network) polar cap potential results showed that the electric field variations played a decisive role in generating the North American negative storm while the thermspheric composition changes were responsible for the North American positive storm and the two South America positive storms.
Deep Learning-Based PM2.5 Long Time-Series Prediction by Fusing Multisource Data—A Case Study of Beijing
Authors: Niu Meng , Zhang Yuqing , Ren Zihe
Published: February 2023

Accurate air quality prediction is of great significance for pollution prevention and disaster prevention. Effective and reliable prediction models are needed not only for short time prediction, but are even more important for long time-series future predictions. In the long time series, most of the current models might not function as accurately as in the short period and thus a new model is required. In this paper, the new PM2.5 predictor is proposed to achieve accurate long time series PM2.5 prediction in Beijing. The predictor simplifies the input parameters through Spearman correlation analysis and implements the long time series prediction through Informer. The results show that AQI, CO, NO2, and PM10 concentrations are selected from the air quality data, and Dew Point Temperature (DEWP) and wind speed are incorporated from two meteorological data to better improve the prediction efficiency by almost 27%. By comparing with LSTM and attention-LSTM models, the model constructed in this paper performs well in different prediction time periods, with at least 21%, 19%, 28%, and 35% improvement in accuracy in four prediction time series: 48 h, 7 days, 14 days, and 30 days. In conclusion, the proposed model is proved to solve the problem of predicting long time series PM2.5 concentrations in the future, which can make up for the shortcomings of the currently existing models and have good application value.
How Cochlear Implant Rehabilitation Impacts the Therapeutic Strategy for Vestibular Schwannoma
Authors: Iannacone Francesco P. , Visconti Francesca , Zanoletti Elisabetta
Published: February 2023

Background: Since both surgery and more conservative treatments show long-term outcomes in patients with VS, the current challenge in its therapeutic strategy is to offer a cure with lower functional morbidity in terms of facial and hearing preservation or the possibility of hearing rehabilitation with a cochlear implant. Methods: PubMed and Scopus databases were searched from 2017 to November 2022. Fifteen articles met our selection criteria: (1) patients with a diagnosis of VS, either sporadic or NF2-related; (2) simultaneous or sequential cochlear implantation; (3) specified audiological test results and follow-up timing. Conclusions: Although the level of evidence for the presently included studies is low due to either the study design or the lack of treatment consensus, CI rehabilitation is a promising option, especially in small VS with compromised hearing and as a salvage option after a failed attempt at hearing preservation surgery.
Radio-Controlled Intelligent UGV as a Spy Robot with Laser Targeting for Military Purposes
Authors: Rahman Muhammad Zia Ur , Raza Umair , Akbar Muhammad Azeem , Riaz Muhammad Tanveer , Gumaei Abdu H. , Ahmad Nasir
Published: February 2023

The main objective of this unmanned ground vehicle is to deal with the security issues like terrorist activities across the border and in various remote combat missions by reducing the involvement of soldiers. This unmanned ground robot comprises a wireless high-definition camera that can transfer live streams from the robot to headquarters using Wi-Fi. The robot’s movement can be controlled with two modes; one of them is a radio controller working on 2.4 GHz frequency with seven independent channels. Secondly, its movement can also be controlled using a Python-based GUI application. Nowadays, different techniques have been used for face recognition; in our remotely piloted robot, we have used Haar-cascade classifiers in combination with the LBPH algorithm to implement real-time facial recognition. The robot uses a rack and pinion driving mechanism and an ATMEL Cortex-M3 CPU as a controller with 32-bit/s processing speed. In addition, a laser is installed on the turret to shoot the targets down, which can be used in an autonomous mode based on facial recognition results, or it can be used manually either through an RF controller or Python-based GUI. The turret moves in 2-DOF with the help of metallic geared servo motors. Both servo motors can rotate up to 180°. The driving mechanism of the robotic tank is just like DDR, with one difference, the two DC gear motors of the robot are connected diagonally.
Interaction of Virus in Cancer Patients: A Theoretical Dynamic Model
Authors: Shakhmurov Veli B. , Kurulay Muhammet , Sahmurova Aida , Gursesli Mustafa Can , Lanata Antonio
Published: February 2023

This study reports on a phase-space analysis of a mathematical model of tumor growth with the interaction between virus and immune response. In this study, a mathematical determination was attempted to demonstrate the relationship between uninfected cells, infected cells, effector immune cells, and free viruses using a dynamic model. We revealed the stability analysis of the system and the Lyapunov stability of the equilibrium points. Moreover, all endemic equilibrium point models are derived. We investigated the stability behavior and the range of attraction sets of the nonlinear systems concerning our model. Furthermore, a global stability analysis is proved either in the construction of a Lyapunov function showing the validity of the concerned disease-free equilibria or in endemic equilibria discussed by the model. Finally, a simulated solution is achieved and the relationship between cancer cells and other cells is drawn.
WiFi-Based Detection of Human Subtle Motion for Health Applications
Authors: Chen Hui-Hsin , Lin Chi-Lun , Chang Chun-Hsiang
Published: February 2023

Neurodegenerative diseases such as Parkinson’s disease affect motor symptoms with abnormally increased or reduced movements. Symptoms such as tremor and hand movement disorders can be subtle and vary daily such that the actual condition of the disease may not fully present in clinical sessions. Health examination and monitoring, if available in the living space, can capture comprehensive and quantitative information about a patient’s motor symptoms, allowing physicians to make a precise diagnosis and devise a more personalized treatment. WiFi-based sensing is a potential solution for passively detecting human motion in a contactless way that collects no personally identifiable information. This study proposed an approach for human micromotion detection using the WiFi channel state information, which can be realized in a regular-sized room for home health monitoring and examination. Three types of motion were tested to evaluate the proposed method in quantifying micromotion using single and multiple WiFi links. The results show that micromotion could be captured at all distributed locations in the experimental environment (4.2 m × 7.9 m). Our computer algorithm computed the frequency and duration of simulated hand tremors with an average accuracy of 90.9% (single WiFi link)—95.7% (multiple WiFi links).
Aldanella attleborensis (Mollusca) from Cambrian Stage 2 of the Three Gorges Area and Its Stratigraphic Implications
Authors: Qiang Yaqin , Guo Junfeng , Li Guoxiang , Song Zuchen , Peng Jiaxin , Sun Jie , Han Jian , Zhang Zhifei
Published: February 2023

Some small shelly fossils are important index fossils for global stratigraphic subdivisions and correlations of the Cambrian Terreneuvian. The first appearance datum (FAD) of the cosmopolitan mollusk Aldanella attleborensis has been suggested as one of the potential markers for defining the base of Cambrian Stage 2. Aldanella fossils were uncommon in South China, and if occurring, were often described as Aldanella yanjiaheensis, A. attleborensis, or indeterminate species in the literature, while A. yanjiaheensis was often taken as a junior synonym of A. attleborensis. Nevertheless, a detailed taxonomic revision of A. yanjiaheensis based on material from its type locality awaits to be made. In this study, we systematically re-evaluated A. yanjiaheensis based on the numerous specimens collected from the base of Member 5 of the Yanjiahe Formation in the Three Gorges area, western Hubei Province of South China. Detailed taxonomic comparison further substantiates that A. yanjiaheensis is a junior synonym of A. attleborensis, signifying its strong potential for a global correlation across paleocontinents. Morphological parameter analyses indicate that the length and width of shell tube of A. attleborensis shows allometric growth. The nearly cosmopolitan distribution and characteristic morphology of A. attleborensis indicate that it can play a significant role in the subdivision and correlation of Cambrian Stage 2. The co-occurrence of A. attleborensis and Watsonella crosbyi from the base of Member 5 of the Yanjiahe Formation corroborates that Member 5 belongs to Cambrian Stage 2.