Value Of Factor Research Articles

Calculation of a conversion factor for estimating the glycolytic contribution in exercise from post-exercise blood lactate concentration.

Purpose: Often, the glycolytic contribution in a bout of heavy or severe intensity exercise is estimated by multiplying the increase in blood lactate concentration above resting levels that is engendered by the exercise (in mM) by 3.3 (or 3) mL·kg-1 per mM. Our purpose was to verify the value of this conversion factor, using methods that were completely different from those of the original studies. Methods: Six women (mean ± SD), age, 23 ± 1year; VO2max, 46 ± 4mL·kg-1·min-1) and three men (23 ± 0years; 54 ± 8mL·kg-1·min-1) completed 6min of heavy intensity exercise in conditions of normoxia and hypoxia (FIO2, ∼12%). VO2 was measured throughout the exercise and 7min of recovery. The increase in glycolytic contribution was estimated as the reduction in aerobic contribution in hypoxia, after correction for the effects of hypoxia on the oxygen demand and on the contribution from phosphocreatine. The peak post-exercise blood lactate concentration was measured in fingerstick blood samples. Results: The ratio between the increase in estimated glycolytic contribution (in mL·kg-1) in hypoxia and the increase in peak blood lactate concentration (in mM) yielded an oxygen equivalent of 3.4 ± 0.4mL·kg-1 per mM (range, 2.6mL·kg-1 per mM to 4.0mL·kg-1 per mM) for cycle ergometer exercise. Conclusion: These results generally support the use of a common conversion factor to calculate the glycolytic contribution from post-exercise blood lactate concentrations. However, there is some inter-individual variability in the conversion factor.

UIO-66-NH2 encapsulated polyoxometalate loaded on graphene oxide accommodated on mixed cellulose esters (MCE) paper for thin film microextraction of pesticides besides their quantification via high-performance liquid chromatography-ultraviolet detection

A POM@UIO-66-NH2/GO composite was designed and prepared via a facile in-situ synthesis method for microextraction purposes. The proper sizes (window size and pore size) of UIO-66-NH2 can effectively seal POM as a monomolecular active component and prevent POM leaching during the extraction. After that, a membrane containing POM@UIO-66-NH2/GO nanocomposite was synthesized and utilized in thin film microextraction (TFME) of various pesticides such as imidacloprid, tebuconazole, and propiconazole as the model analytes in different real samples such as cucumber, tomato, potato, head lettuce, and strawberry. It is worth mentioning that the introduction of GO can improve the electron transfer of the sorbent. The extracted model analytes were desorbed by a suitable organic solvent. The extracted analytes were quantified via high-performance liquid chromatography-ultraviolet detection (HPLC-UV). Under the optimized condition, the method's linear dynamic range (LDR) was obtained in the range of 1.0–200.0 μg L−1 for testing analytes. The obtained correlation coefficients (r2) were higher than 0.9918. The limits of detection (LODs) were also calculated to be between 0.31 and 0.34 μg L−1. The relative standard deviations (%RSDs) were obtained in the range of 2.06 to 4.11. The enrichment factor (EF) values for the studied analytes were also obtained in the range of 89–102. The obtained recoveries indicated that the presented method is useful for analyzing pesticides in various real samples.

Impact Resistance of Rubberized Alkali-Activated Concrete Incorporating Recycled Aggregate and Recycled Steel Fiber

Alkali-activated concrete (AAC) features excellent mechanical properties and sustainability. The incorporation of crumb rubber (CR), recycled concrete aggregates (RCAs), and recycled steel fibers (RSFs) can further enhance environmental sustainability. This paper mainly investigated the dynamic behaviors of a novel rubberized AAC incorporating RCAs and RSFs (RuAAC) through Split-Hopkinson Pressure Bar (SHPB) tests. The variables included three types of RSF content (1%, 2% and 3%), five types of rubber content (0%, 5%, 20%, 35% and 50%) and five impact pressures (0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa and 0.9 MPa). Dynamic stress–strain curves, dynamic strength, the dynamic increase factor (DIF), impact toughness and the synergistic effects of RSF and CR were discussed. The results show that increasing RSF and CR contents could improve the impact resistance of RuAAC under impact loading. The RuAAC exhibited significant strain rate sensitivity, and the sensitivity increased with larger contents of RSF and CR. The increase in strain rate sensitivity was more pronounced with higher CR contents, which was reflected in larger dynamic increase factor (DIF) values. Under high impact pressure, the impact toughness was obviously enhanced with higher RSF contents, while the contribution of increased CR content to impact toughness was not apparent, which may be attributed to the fact that this study only calculated the integral under the dynamic stress–strain curve before the peak stress to determine impact toughness, neglecting the potential contribution of CR particles after the peak point. The obvious strain sensitivity exhibited by the RuAAC in the SHPB tests indicated superior impact performance, making it particularly suitable for architectural structures prone to seismic or explosive impacts.

Utilizing the lignocellulosic fibers from Pineapple Crown Leaves extract for enhancing TiO2 interfacial bonding in dye-sensitized solar cell photoanodes

AbstractThe crown leaves of pineapple possess a wealth of smooth and glossy silk medium-length fibers, primarily composed of cellulose and lignin, accompanied by constituents such as fats, waxes, pectin, uronic acid, anhydride, pentosan, color pigments, and inorganic substances. These fibers exhibit an anisotropic nature and are characterized by hydrogen bonding interactions, rendering them effective in conjunction with semiconductor oxide (TiO2) through their cellulosic fibrils. The dye extracted from Pineapple Crown Leaves (PCL) using ethanol was subjected to FTIR and UV–visible spectroscopy. The FTIR analysis revealed absorption peaks at 3268 cm−1 and 2922 cm−1, confirming the presence of –OH and –CH stretching attributed to the fibrils within the dye. UV–visible spectroscopy further demonstrated absorption within the visible region of the electromagnetic spectrum. Additionally, a photoluminescence study of the dye showcased emission within the visible range of the electromagnetic spectrum. Subsequently, a solar cell incorporating this dye underwent JV characterization, yielding an efficiency of 1.0034%, along with fill factor, open-circuit voltage, and short-circuit current density values of 0.40644, 0.7058 V, and 3.4906 mA/cm2, respectively. To gain deeper insights and facilitate optimization for large-scale installations, a simulation model utilizing PC1D was proposed to explore the influential parameters of the Dye-sensitized solar cell (DSSC).

Analysis of coated samples containing hydroxyapatite/multiwalled carbon nanotubes on 2205 DSS substrate

For biomedical applications, hydroxyapatite and carbon nanotubes are currently being applied over duplex stainless steel (DSS) alone in order to increase corrosion resistance and biocompatibility. A composite of hydroxyapatite and multi-walled carbon nanotubes was used to improve biocompatibility, osseointegration, and corrosion resistance on 2205 DSS using electrophoretic deposition. The study investigates the effects of potential and time on the properties of the deposited layer in order to determine electrophoretic deposition factor values that are appropriate. The coating properties and effective groups of the phase resulting from this process are determined by Fourier transform infrared spectroscopy and X-ray diffraction. The antibacterial properties of E. coli bacterial strains are investigated for the coated layer. The adhesion between the hydroxyapatite and multi-walled carbon nanotube layers on the 2205 duplex stainless steel substrate was qualitatively evaluated using the adhesive tape test. It was found that the optimal suspension, which consists of 65 weight percent hydrogen acetate and 35 weight percent multi-walled carbon nanotubes, had a homogeneous morphology, a thick structure, and no cracks when coated at 50 V for two minutes.

MRI-based parameters and clinical risk factors to predict lymph node metastasis in patients with ypT0 rectal cancer after neoadjuvant chemoradiotherapy.

The aim of this study was to assess the significant risk factors that predict lymph node metastasis in ypT0 patients with locally advanced rectal cancer following chemoradiotherapy (CRT). Additionally, the study aimed to identify high-risk groups who would not be suitable candidates for a rectal-preserving strategy, despite achieving a complete tumour response. Between 2013 and 2021, 226 ypT0 patients with stages II/III rectal cancer underwent CRT and radical surgery were enrolled. Two groups of patients were evaluated: those with lymph nodes metastasis and those without. The selection of variables for multivariable logistic regression was conducted through bivariate logistic regression analysis. Furthermore, the determination of optimal cutoff values for risk factors was achieved using ROC curve analysis. Nearly 8% (18/226) of patients with ypT0 had positive lymph nodes (LN) on final pathology. Four variables resulted as being independent factors of LN metastasis: pre-CRT tumour movability (OR = 8.618, P = 0.003), pre-CRT maximal LN size (OR = 28.474, P = 0.004), post-CRT tumour vertical length (OR = 1.492, P = 0.050), post-CRT anaemia (OR = 10.288, P = 0.001). The optimal cutoff point of pre-CRT maximal LN size and post-CRT tumour vertical length was 7.50 mm and 3.05 cm, respectively. The prevalence of lymph node metastasis remains at 8% among patients who achieve pathological complete regression of the primary tumour. In instances where patients are considered appropriate candidates for a rectal-preserving strategy after clinical complete remission, careful consideration should be given to the selection of this strategy if specific risk factors are present. These risk factors encompass a maximal LN size surpassing 7.50 mm prior to CRT, a fixed tumour prior to CRT, a tumour vertical length exceeding 3.05 cm after CRT, and the existence of anaemia subsequent to CRT.

The magnitude of perinatal depression and associated factors among women in Kutaber woreda public health institution and Boru Meda general hospital, Ethiopia, 2022: a cross-sectional study.

Perinatal depression, characterized by the presence of depressive symptoms during pregnancy and/or within the first 12 months postpartum, poses a significant global public health concern. It contributes to a multitude of health risks for mothers, their infants, and their families. Understanding of perinatal depression and its associated factors is crucial for effective prevention and intervention strategies. However, there is a lack of comprehensive research on this topic in Ethiopia. Therefore, this study aims to determine the prevalence and factors contributing to perinatal depression among Ethiopian women. An institutional-based cross-sectional study was conducted, involving 552 women receiving perinatal services at Kutaber district health institution and Boru Meda General Hospital. Study participants were selected through systematic random sampling techniques. Perinatal depression was assessed using the Depression, Anxiety, and Stress Scale-21 (DASS-21). The associations between various determinants and perinatal depression were examined using binary logistic regression, and factors with a p-value of less than 0.2 were included in the multiple logistic regression analysis. A p-value less than 0.05 was considered statistically significant. The prevalence of perinatal depression was found to be 32.2%. The prevalence of perinatal depression was found to be 32.2%. Factors significantly associated with perinatal depression included being a student [adjusted odds ratio (AOR) = 4.364, 95% confidence interval (CI): 1.386, 13.744], experiencing excessive pregnancy-related concerns (AOR = 1.886, 95% CI: 1.176, 3.041), past substance use (AOR = 2.203, 95% CI: 1.149, 4.225), the presence of anxiety symptoms (AOR = 3.671, 95% CI: 2.122, 6.352), experiencing stress symptoms (AOR = 6.397, 95% CI: 3.394-12.055), and daytime sleepiness (AOR = 2.593, 95% CI: 1.558, 4.316). The findings of this study indicate a relatively high prevalence and valuable factors associated with perinatal depression. It highlights the need for a comprehensive approach to perinatal mental health that takes into account not only the biological aspects of pregnancy but also the psychological, social, and lifestyle factors that can impact a person's mental well-being during this critical period.

Statistical Analysis of the Role of Cavity Flexibility in Thermostability of Proteins.

Conventional statistical investigations have primarily focused on the comparison of the simple one-dimensional characteristics of protein cavities, such as number, surface area, and volume. These studies have failed to discern the crucial distinctions in cavity properties between thermophilic and mesophilic proteins that contribute to protein thermostability. In this study, the significance of cavity properties, i.e., flexibility and location, in protein thermostability was investigated by comparing structural differences between homologous thermophilic and mesophilic proteins. Three dimensions of protein structure were categorized into three regions (core, boundary, and surface) and a comparative analysis of cavity properties using this structural index was conducted. The statistical analysis revealed that cavity flexibility is closely related to protein thermostability. The core cavities of thermophilic proteins were less flexible than those of mesophilic proteins (averaged B' factor values, -0.6484 and -0.5111), which might be less deleterious to protein thermostability. Thermophilic proteins exhibited fewer cavities in the boundary and surface regions. Notably, cavities in mesophilic proteins, across all regions, exhibited greater flexibility than those in thermophilic proteins (>95% probability). The increased flexibility of cavities in the boundary and surface regions of mesophilic proteins, as opposed to thermophilic proteins, may compromise stability. Recent protein engineering investigations involving mesophilic xylanase and protease showed results consistent with the findings of this study, suggesting that the manipulation of flexible cavities in the surface region can enhance thermostability. Consequently, our findings suggest that a rational or computational approach to the design of flexible cavities in surface or boundary regions could serve as an effective strategy to enhance the thermostability of mesophilic proteins.

Investigating the Social Capital Variability of Highschool Students in Taiwan, Focusing on Gender Differences

This research investigated the variation in Social Capital (SC) among high school students in Taiwan, focusing on gender disparities. The study involved 853 students from seven randomly selected high schools in central Taiwan, with 509 girls and 344 boys participating. The researcher utilized a 24-item questionnaire developed by Khodadady and Zabihi (2011) after making some adjustments. The survey covered five overarching factors of SC: 1) “Parental & Family Consultation/Support”, 2) “Family-School Interaction”, 3) “School & Social Activities”, 4) “Peer Interaction”, and 5) “Family Bonds”. Using a Pearson Chi-square test (α ≤ 0.05), each of the 24 survey items was analyzed. The findings indicated that the viewpoints of Taiwanese high school boys and girls regarding their social capital status were highly similar, with some items being identical. The only statistically significant difference observed were items 1, 3, 10, 16, and 23. These results implied that, except for Item 1, boys tended to perceive slightly higher SC benefits compared to girls. Additionally, and based on the descriptive rubrics devised by the author, girls displayed slightly higher values than boys in Factor 2, whereas boys exhibited slightly higher values in Factor 1 and Factor 3. Both genders provided nearly equal responses for Factors 4 and 5.

Data-driven strategies for accurate volume-to-biomass conversions

ABSTRACT This document presents a method for estimating conversion factors from volume to green weight and from volume to oven dry weight using ratio and linear and nonlinear regression estimators, and the results of its use in nine raw materials, including roundwood from harvest and sawmill offcuts. Although no differences were detected in either the value or accuracy of the linear factors, the linear estimator tended to have slightly higher accuracy than the ratio estimator. Linear conversion factors obtained using regression through the origin were accurate, especially those for roundwood. In general, the conversion factors from volume to green weight were more precise than those from volume to dry weight. Conversion factors from volume to dry weight are useful only in situations in which the moisture range of application is like that used for obtaining those average factors. In addition, given that the green volume-weight factor can be adjusted to the observed moisture in the raw material for which dry weight is intended to be determined, it is advisable to concentrate efforts on this type of factor in future studies. Nonlinear regression estimators are an alternative to linear regression estimators through the origin for determining conversion factors from volume to dry weight. In all the analyzed raw materials, a decrease in the conversion factor from volume to dry weight was observed as the moisture content increased. This is an unexpected outcome that cannot be explained by the variables recorded in this study.

Influence of fin length and width on flow and heat transfer performance of miniature heat sinks

Miniature heat sinks are employed in electronic cooling applications owing to greater heat transfer characteristics and better surface-to-volume ratio. Pin fins are typically used to further enhance the thermal-hydraulic performance of such heat sinks. The present numerical investigation analyses the effect of both relative height (Hr = h/hc) as well as relative width (Wr = w/wc) of pinfin for the channel having a rectangular cross-section of 1.5 mm and 1 mm in width (wc) and height (hc) respectively while keeping the flow laminar. Five models having different Hr (0.2 to 1.0) and five models having different Wr(0.066 to 0.333) are investigated and the results are compared with the rectangular channel without fin. Findings indicate significant enhancement of thermal-hydraulic performance with increasing fin relative height as well as relative width which tends to increase flow resistance. Relative height on fins improves the Nusselt number by 11.40 %–84.81 %, while relative width increases it by 14.92 %–94.32 % for the examined range of Reynolds numbers. The microchannel that has the highest value of thermal performance factor (1.46) in the model has Hr = 0.8 and Wr = 0.333.

Origin of quartz and its implications for different phase fluids in lacustrine shales from the Qingshankou Formation, southern Songliao Basin, China

Quartz, an important mineral that occurs in lacustrine shales, can be of different types and origins. Yet, only few studies have investigated how quartz from different sources contribute to phase fluids, such as adsorbed and free fluids present within shale matrix pores. This study integrates various experimental techniques, including X-ray diffraction analysis, geochemical analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and high-frequency two-dimensional nuclear magnetic resonance analysis to quantitatively characterize the different phase fluids associated with various types of quartz occurring in the Qingshankou Formation shale. The characterization results indicated four distinct quartz types: silt-sized quartz, microcrystalline quartz linked with clay minerals, organism-skeletal quartz, and quartz aggregates comprising multiple crystals. The Fe–Al–Mn ternary diagram and SiO2 versus Zr scatter plot indicate that terrigenous clastic material is the primary source of SiO2 in shale quartz. Smectite-to-illite transition plays a pivotal role in authigenic quartz formation. Based on quartz concentration data obtained using major element analysis, we estimated the ranges of terrigenous clastic quartz, diagenetic quartz formed by the smectite-to-illite transition, and biogenic quartz concentrations to be from 55.49% to 92.03% (average 84.70%), 6.67%–20.30% (average 13.12%), and 0%–24.21% (average 2.17%), respectively. The solid organic matter in shale is affected by both terrigenous detrital quartz and authigenic quartz transformed from the clay in the basin. Authigenic quartz, formed by the smectite-to-illite transition, considerably enhances the development of solid organic matter in the Qingshankou Formation. By contrast, an abundance of terrigenous detrital quartz can lead to a dilution of the solid organic matter. Thus, this study provides the first direct evidence that along with a high value of bio-organic matter yield factor, the source of quartz plays a significant role in controlling organic matter abundance.

The influence of the environmental factors on the accumulation patterns of toxic elements in Plantago lanceolata sampled in the area under strong anthropopressure

The study aims to explore the environmental factors which activate accumulation abilities of Plantago lanceolata in the research area under strong anthropopressure resulting from the long-term pollution originating from copper mining-metallurgical activities in Southeastern Europe. Sampling was performed at the most endangered sites regarding its proximity to the major and/or secondary pollution sources, as well at the control site. The content of toxic elements (Al, Cu, Fe, Mn, Ni, Pb and Zn) was determined in the roots, leaves, stalks and flowers of P. lanceolata. The anthropogenic origin of environmental contamination was denoted through the high concentrations of Cu, Pb and Zn in the leaves of P. lanceolata, reaching toxic levels, combined with the enrichment of plant parts (Enrichment factor >2), especially with Cu (as well as with Al, Fe, Ni and Zn) in samples from the immediate proximity to the copper smelter or at the prevailing wind directions. Biomonitoring potential, assessed through the correlations between toxic element content, as well as the values of Enrichment factor, was indicated for roots (in the case of Cu), all the aboveground plant parts (Fe) and stalks (Zn). The results have shown that the contents of toxic elements in plant parts as well as phytoremediation of P. lanceolata were dependent on soil element content, soil physico-chemical properties and soil enzyme activities, which were regarded as the main environmental drivers affecting phytoremediation ability. The analysis of biological factors (bioconcentration, translocation and bioaccumulation factor) indicated exclusion strategy and possible usage of P. lanceolata in phytostabilization of Zn. The results indicated that the study area is 'environmental hotspot' with potential threat to human health due to the high levels of bioaccumulation of the investigated toxic elements in P. lanceolata parts.

Pulsed low dose rate radiation to mitigate tumor-permissive responses in pancreatic cancer-associated fibroblasts: Introducing the HOST-factor.

682 Background: Pancreatic ductal adenocarcinoma (PDAC) features a distinctive tumor microenvironment comprising cancer-associated fibroblasts (CAFs) and their self-produced extracellular matrix (ECM), forming functional CAF units (CAF u). The current total neoadjuvant therapy (TNT), involving conventional chemoradiotherapy (CRT), yields suboptimal responses while promoting a tumor-permissive CAF u state. To address this, we explored pulsed low dose rate radiation (PLDR)-based TNT, as an alternative to CRT, to treat three-dimensional in vivo-like human PDAC CAF u cultures. We assessed gemcitabine combined with PLDR versus CRT using theHOST Factor, a “harmonized output of stroma traits” factor, comprising several established CAF u functional indicators, which inform on the functional status of the PDAC microenvironment. Methods: The unique CAF u functional values used corresponded to: i) ECM anisotropy; ii) persistent cell-ECM signaling; iii) sustained cytokine-induced activation; iv) cytoskeletal bundling; and v) systemic features of fibroblastic activation. The validity of the resultant HOST factor was assessed using the unit’s ECM ability to elicit fibroblastic activation, indicated by a high αSMA/F-actin ratio value. Results: Ex-vivo CRT led to a HOST factor that was 2-fold greater than chemotherapy alone (p=0.6), which was functionally gauged as a tumor-permissive CAF u. In contrast, PLDR averted CRT-induced tumor-permissive response and established a 6-fold lower HOST factor, suggestive of a “normalized” CAF u, when compared to the HOST factor value established when using conventional TNT (P=0.0016 vs. CRT, and P= 0.0086 vs. gemcitabine alone). The multi-parameter HOST factor validity was confirmed as CRT treated CAF u’s ECM activated human pancreatic fibroblasts (αSMA/F-actin = 70% ± 29) while PLDR-treated CAF u's ECM failed to do so (αSMA/F-actin = 32% ± 26), reaching a 30% mean rank difference (P <0.0001). Conclusions: PLDR mitigates conventional CRT-based TNT-induced tumor-permissive responses, restoring the fibroblastic units' tumor-suppressive function. These results lend support to a phase 1 trial designed to evaluate whether radiation with PLDR-based TNT, constitutes a safe and more effective treatment for PDAC patients. The novel HOST factor is being used to appraise specimens from NCT04452357.

Sommerfeld enhancement for puffy self-interacting dark matter

We examine the Sommerfeld enhancement effect for the puffy self-interacting dark matter. We find out two new parameters to classify the self-scattering cross section into the Born, the resonance and the classical regimes for the puffy dark matter. Then we observe that the resonance peaks for the puffy dark matter self-scattering and for the Sommerfeld enhancement effect have the same locations. Further, we find that for a large ratio between Rχ (radius of a puffy dark matter particle) and 1/mϕ (force range), the Sommerfeld enhancement factor approaches to 1 (no enhancement). Finally, for the puffy SIDM scenario to solve the small-scale problems, the values of the Sommerfeld enhancement factor are displayed in the allowed parameter regions.

Assessing the safety and efficacy of DIY-homemade sunscreens with natural, aromatic and herbal ingredients

Sunscreen products are widely used during the summer months to protect against increased sunlight exposure. While there have been advancements in the effectiveness and safety of commercial sunscreens, there is a growing interest in "completely natural" and homemade skincare products, including sunscreens. These homemade alternatives often incorporating aromatic and medicinal herbal preparations, are being touted as safe alternatives on online social media platforms and alternative health websites. It is essential to recognize that scientific research has primarily focused on evaluating the effectiveness and safety of commercially available sunscreen products. Concerns have arisen regarding the potential risks associated with non-commercial sunscreens, particularly those labeled as "homemade" or "completely natural." Therefore, it is crucial to investigate whether these DIY sunscreen products, advertised as natural and additive-free, pose any health threats due to their inadequate sun protection properties. This study aims to examine the formulations of these proposed homemade sunscreen products, specifically evaluating their durability, protection against ultraviolet A and B (UVA and UVB) radiation, and average sun protection factor (SPF) values from a toxicological perspective. Emphasizing the importance of safety in sunscreen products is paramount, as the use of unsafe sunscreens can lead to serious health risks, including skin cancer, premature aging, and other skin disorders.

Analysis of the Effects of Parameters on the Performance of Resonators Based on a ZnO/SiO2/Diamond Structure

With the development of communications technology, surface acoustic wave (SAW) and bulk acoustic wave (BAW) devices have become hotspots of the competitive research in the frequency band above GHz. It imposes higher requirements on the operating frequency, temperature coefficient of frequency (TCF), and electromechanical coupling coefficient (k2) of SAW devices. In this work, we reported on a novel ZnO/SiO2/diamond-layered resonator structure and systematically investigated its propagation characteristics by using finite element methods. A comparative study and analysis of k2 and acoustic velocity (vp) for both the excited Rayleigh mode and the Sezawa mode were conducted. By selecting the appropriate ZnO piezoelectric film, SiO2, and electrode thickness, the Sezawa mode was chosen as the main mode, effectively improving both k2 and vp. It was observed that the k2 of the Sezawa mode is 7.5 times that of the excited Rayleigh mode and nearly 5 times that of piezoelectric single-crystal ZnO; vp is 1.7 times that of the excited Rayleigh mode and nearly 1.5 times that of piezoelectric single-crystal ZnO. Furthermore, the proposed multilayer structure achieves a TCF close to 0 while maintaining a substantial k2. In practical applications, increasing the thickness of SiO2 can compensate for the device’s TCF reduction caused by the interdigital transducer (IDT). Finally, this study explored the impact of increasing the aperture width and IDT pairs on the performance of the single-port resonator, revealing the changing patterns of quality factor (Q) values. The results reported here show that the structure has great promise for the fabrication of high-frequency and low-TCF SAW devices.

Hyper-Heuristic Approach for Tuning Parameter Adaptation in Differential Evolution

Differential evolution (DE) is one of the most promising black-box numerical optimization methods. However, DE algorithms suffer from the problem of control parameter settings. Various adaptation methods have been proposed, with success history-based adaptation being the most popular. However, hand-crafted designs are known to suffer from human perception bias. In this study, our aim is to design automatically a parameter adaptation method for DE with the use of the hyper-heuristic approach. In particular, we consider the adaptation of scaling factor F, which is the most sensitive parameter of DE algorithms. In order to propose a flexible approach, a Taylor series expansion is used to represent the dependence between the success rate of the algorithm during its run and the scaling factor value. Moreover, two Taylor series are used for the mean of the random distribution for sampling F and its standard deviation. Unlike most studies, the Student’s t distribution is applied, and the number of degrees of freedom is also tuned. As a tuning method, another DE algorithm is used. The experiments performed on a recently proposed L-NTADE algorithm and two benchmark sets, CEC 2017 and CEC 2022, show that there is a relatively simple adaptation technique with the scaling factor changing between 0.4 and 0.6, which enables us to achieve high performance in most scenarios. It is shown that the automatically designed heuristic can be efficiently approximated by two simple equations, without a loss of efficiency.

Research on Modulation Signal Denoising Method Based on Improved Variational Mode Decomposition

In order to further analyze the micro-motion modulation signals generated by rotating components and extractmicro-motion features, a modulation signal denoising algorithm based on improved variational mode decomposition (VMD)is proposed. To improve the time-frequency performance, this method decomposes the data into narrowband signalsand analyzes the internal energy and frequency variations within the signal. Genetic algorithms are used to adaptivelyoptimize the mode number and bandwidth control parameters in the process of VMD. This approach aims to obtain theoptimal parameter combination and perform mode decomposition on the micro-motion modulation signal. The optimalmode number and quadratic penalty factor for VMD are determined. Based on the optimal values of the mode numberand quadratic penalty factor, the original signal is decomposed using VMD, resulting in optimal mode number intrinsicmode function (IMF) components. The effective modes are then reconstructed with the denoised modes, achieving signaldenoising. Through experimental data verification, the proposed algorithm demonstrates effective denoising of modulationsignals. In simulation data validation, the algorithm achieves the highest signal-to-noise ratio (SNR) and exhibits the bestperformance.

Analyzing the Automatic Power Level Control Effect of a Signal Generator in RF Power Sensor Calibration by a Direct Comparison Transfer Method and a Millimeter Wave Application.

Most calibration laboratories prefer the Direct Comparison Transfer Method (DCTM) for a reliable and accurate calibration of power sensors in the radio frequency (RF) scope. Most studies suggest using this calibration method, with its automatic power level control (APLC) of RF signal generators. The APLC is preferred to keep the output power level of the signal generator the same, while the power sensor is calibrated and the reference power sensor is connected to the measurement system. The known APLC mechanisms are also explained for the DCTM, and a comparison of the calibration factor values carried out with and without the automatic power level control process in the DCTM is also given in this study. RF power sensor calibrations with coaxial and waveguide connector types are examined with DCTM in this study as well. This study shows that the DCTM, unless with APLC, should be applied for the waveguide power sensor's calibration at millimeter wave frequencies.