Miracle-dz/UniFAR-FTUs huggingface dataset:
Design and analysis of a d15 mode piezoelectric energy generator using friction-induced vibration

Research works have been conducted on transverse and longitudinal mode piezoelectric energy generation to collect energy from ambient vibrations. However, the inconsistency with the frequency of the energy source and low output power density remain problems for high energy output. In this work, we propose a shear mode piezoelectric energy generator, which utilizes the friction-induced vibration (FIV) and high shear mode piezoelectric coefficient to improve the energy output. A piezoelectric coupled FIV mathematical model is developed to accurately calculate the dynamic vibration response and voltage output. The dynamic voltage response is validated by experiment, and it proves the possibility of continuous friction-induced high-frequency vibration. The energy generation process is evaluated by transient charging simulation of a storage capacitor through an iteration process, which was experimentally validated in the literature. Parameter studies have been conducted to investigate the influences of the piezoelectric patch dimensional parameters, vibration system parameters, friction model parameters, methods of electrical connections, and different piezoelectric materials on the energy generation performance to provide guidance for better design. Under ideal experiment conditions with proper parameters, a volume of 6.25×10−8 m3 PZT4 piezoelectric material indicates root mean square (RMS) charging power density of 5.38×103 Wm−3 and 4.70×103 Wm−3 with electrically in parallel and electrically in series, respectively. While using the same amount of material and structural setup, the single crystal PMN-PT piezoelectric material shows RMS charging power density of 2.72×104 Wm−3 and 2.58×104 Wm−3 with electrically in parallel and electrically in series, correspondingly. These promising results demonstrate that close to W-level RMS charging power output may be realized by structure optimization of energy generator design and incorporating multiple generators together for operation. Possible incorporation into vehicle braking systems can be considered to utilize the wasted friction energy, and it may offer an energy supply for low-power wireless devices.
Efforts to Improve Student Activities and Outcomes in Physics Learning Using the Two Stay Two Stray Technical Cooperative Learning Model at Senior High School

Purpose of the study: The research aims to increase students' activity and learning outcomes in Class X in Senior high school 10 Kota Jambi. Methodology: The research method used is mixed. This research is a Classroom Action Research carried out in three cycles. Retrieval of qualitative data using student activity observation sheets and teacher activity during the teaching and learning process. Retrieval of quantitative data in the form of objective tests held at the end of each learning cycle. Main findings: From the results of the study, it showed that there was an increase in learning outcomes for each cycle, namely, 59.53 for the cycle I to 69.38 for cycle II and 75.48 for cycle III. While increasing the average percentage of student activity. In cycle I was 47.24%, the average percentage of student activity increased to 60.17% in cycle II, and experienced another increase in cycle III to 70.87%. Novelty/Originality of this study: That research using the two stay two stray learning model to improve learning outcomes is very little done in high schools, mostly the application of the two stay two stray model is applied in elementary schools
Aerodynamic design optimization via reduced Hessian SQP with solution refining

An all-at-once reduced Hessian Successive Quadratic Programming (SQP) scheme has been shown to be efficient for solving aerodynamic design optimization problems with a moderate number of design variables. This paper extends this scheme to allow solution refining. In particular, we introduce a reduced Hessian refining technique that is critical for making a smooth transition of the Hessian information from coarse grids to fine grids. Test results on a nozzle design using quasi-one-dimensional Euler equations show that through solution refining the efficiency and the robustness of the all-at-once reduced Hessian SQP scheme are significantly improved.
Assessment of the Environmental Impact of Food Consumption in Ireland—Informing a Transition to Sustainable Diets

Dietary changes are required to mitigate the climatic impact of food consumption. Food consumption databases can support the development of sustainable food based dietary guidelines (SFBDG) when linked to environmental indicators. An improved knowledge base is crucial to the transition to sustainable diets, and multiple environmental indicators should be considered to ensure this transition is evidence based and accounts for trade-offs. The current study aimed to quantify the environmental impact of daily diets across population groups in Ireland. Nationally representative food consumption surveys for Irish children (NCFSII; 2017–2018), teenagers (NTFSII; 2019–2020), and adults (NANS; 2008–2010) were used in this analysis. Blue water use (L) and greenhouse gas emissions (GHGe; kgCO2eq) were assigned at food level to all surveys. Cropland (m2), nitrogen (kgN/t), and phosphorous use (kgP/t) were assigned at the agricultural level for adults. Multiple linear regressions, Spearman correlations, and ANCOVAs with Bonferroni corrections were conducted. Higher environmental impact diets were significantly associated with demographic factors such as age, education status, residential location, and sex, but these associations were not consistent across population groups. The median greenhouse gas emissions were 2.77, 2.93, and 4.31 kgCO2eq, and freshwater use per day was 88, 144, and 307 L for children, teenagers, and adults, respectively. The environmental impact of the Irish population exceeded the planetary boundary for GHGe by at least 148% for all population groups, however the boundary for blue water use was not exceeded. Meat and meat alternatives (27–44%); eggs, dairy, and dairy alternatives (15–21%); and starchy staples (10–20%) were the main contributors to GHGe. For blue water use, the highest contributors were meat and meat alternatives in children; savouries, snacks, nuts, and seeds in teenagers; and eggs, dairy, and dairy alternatives in adults (29–52%). In adults, cropland use, nitrogen use, and phosphorous use exceeded planetary boundaries by 277–382%. Meat, dairy, and grains were the main contributors to cropland, nitrogen, and phosphorous use (79–88%). The quantified environmental impact of Irish diets provides a baseline analysis, against which it will be possible to track progress towards sustainable diets, and the basis for the development of Sustainable Food Based Dietary Guidelines in Ireland.
Optimal hop-by-hop flow control in computer networks

The problem of hop-by-hop flow control in a computer network is formulated as a Markov decision process with a cost function composed of the delay of the messages and the buffer constraints. The optimal control is shown to be a linear truncated function of the state and the explicit form is found when the arrival process of the messages is a Bernoulli process. For a renewal arrival process, the long-rnn average cost of any policy with a linear truncated structure is expressed by a set of linear equations.
Generalized linear item response theory.

In this article generalized linear item response theory is discussed, which is based on the following assumptions: (a) A distribution of the responses occurs according to a given item format; (b) the item responses are explained by one continuous or nominal latent variable and p latent as well as observed variables that are continuous or nominal; (c) the responses to the different items of a test are independently distributed given the values ofthe explanatory variables; and (d) a monotone differentiable function g of the expected item response τ is needed such that a linear combination of the explanatory variables is a predictor of g(τ)
Review on Hybrid Reinforced Polymer Matrix Composites with Nanocellulose, Nanomaterials, and Other Fibers

The use of composite materials has seen many new innovations for a large variety of applications. The area of reinforcement in composites is also rapidly evolving with many new discoveries, including the use of hybrid fibers, sustainable materials, and nanocellulose. In this review, studies on hybrid fiber reinforcement, the use of nanocellulose, the use of nanocellulose in hybrid forms, the use of nanocellulose with other nanomaterials, the applications of these materials, and finally, the challenges and opportunities (including safety issues) of their use are thoroughly discussed. This review will point out new prospects for the composite materials world, enabling the use of nano- and micron-sized materials together and creating value-added products at the industrial scale. Furthermore, the use of hybrid structures consisting of two different nano-materials creates many novel solutions for applications in electronics and sensors.
Response of internal solitary waves to tropical storm Washi in the northwestern South China Sea

Based on in-situ time series data from an array of temperature sensors and an acoustic Doppler current profiler on the continental shelf of the northwestern South China Sea, a sequence of internal solitary waves (ISWs) were observed during the passage of tropical storm Washi in the summer of 2005, which provided a unique opportunity to investigate the ISW response to the tropical cyclone. The passing tropical storm is found to play an important role in affecting the stratification structure of the water column, and consequently leading to significant variability in the propagating features of the ISWs, such as the polarity reversal and amplitude variations of the waves. The response of the ISWs to Washi can be divided into two stages, direct forcing by the strong wind (during the arrival of Washi) and remote forcing via the near-inertial internal waves induced by the tropical storm (after the passage of Washi). The field observations as well as a theoretical analysis suggest that the variations of the ISWs closely coincide with the changing stratification structure and shear currents in accompanied by the typhoon wind and near-inertial waves. This study presents the first observations and analysis of the ISW response to the tropical cyclone in the South China Sea.
Identification of Stiffness Reductions Using Natural Frequencies

A technique is presented for the identification of localized reductions in the stiffness of a structure using natural frequency measurements. The sensitivities of the eigenvalues to localized changes in the stiffness have been developed as a set of underdetermined equations. These equations have been used as the constraints in an optimization problem, which minimizes one of three criteria: (1) the changes in the element stiffnesses; (2) the norm of the changes to the global stiffness matrix; or (3) the residuals of the eigenvalue problem. An additional constraint, which forces the stiffness to always decrease due to damage, places the optimization problem in the realm of nonlinear programming. The overall formulation has provided a useful method to identify damage with a small number of measured natural frequencies. Ten to 90% localized reduction in stiffness was successfully identified in a 10-story, two-bay steel frame. The method was verified using test data from an aluminum, cantilever beam.
Depolarization properties of offset reflector antennas

The cross polarized radiation for linearly polarized excitation and the beam displacement for circularly polarized excitation have been investigated for offset reflector antennas. Numerical calculations are given to illustrate the dependence upon the angle \theta_{0} between the feed axis and the reflector axis as well as upon the half-angle \theta_{c} subtended at the focus by the reflector. In the case \theta_{0} = \theta_{c} = 45\deg , measured results have been obtained for both linearly and circularly polarized excitations with a dual mode feed illuminating an offset paraboloid. The cross polarized radiation of horn reflector and open Cassegrainian antennas rises sharply to rather high values off the beam axis; however, in general, the maximum cross polarized radiation of offset reflector antennas can be made small by using a small angle between the feed and reflector axes. The cross polarization caused by offset is compared with that caused by an unbalanced feed pattern. The effect of the longitudinal current distribution and of departure of the surface from a paraboloid on cross polarization are also examined. The clarification of these cross polarization properties is found to be valuable in the design of reflector antennas.
Determination Levels of Caffeine Isolated from Robusta Coffee Beans from Pagar Alam in Wistar Rat Blood

Coffee provides a genuine source of caffeine. Caffeine can have a variety of pharmacological effects on both central and peripheral nervous systems and most of these effects are related to the antagonistic mechanism at adenosine receptors. The most prominent effect of caffeine remains stimulation of brain function, improving mood and physical performance. Robusta coffee obtains an intense level of caffeine and Pagar Alam City is one of the cities in Indonesia that produces robusta coffees. This study aims to identify and characterize caffeine isolated from Pagar Alam robusta coffee beans using thin-layer chromatography methods, UV-Visible spectrophotometry and to determine caffeine levels in wistar rat blood using the ELISA method. This method is cost-effective, familiar to perform and has a considerable degree of accuracy and reproducibility. The isolated samples have similar characteristics to standard caffeine with an Rf value of 0.77, a maximum wavelength at 273 nm with the absorbance of 1.3 and from caffeine profile in the blood sample we obtained the maximum sample concentration in blood 0.582 ± 0.249 μg/ml and the time needed to reach the maximum concentration is 30 minutes.
Topology optimization of muffler internal partitions for improving acoustical attenuation performance

The internal partition configuration of an expansion chamber muffler affects significantly its acoustical transmission characteristics, but the use of systematic optimization methods to muffler design problems is rare. The main objective of this research is to maximize the transmission loss at target frequencies by optimizing partition layouts inside a muffler chamber by formulating an acoustical topology optimization problem. The selected target frequencies include the deep frequencies of a nominal muffler in order to see the critical effects of partition configurations on the acoustical transmission characteristics. The effects of partition volume constraint ratios are also investigated and physics behind the optimized layouts is investigated. Numerical results show that mufflers with optimized partition layouts outperform nominal mufflers considerably, but the shapes and locations of the optimized partitions should be much different from those of conventional partitions. Copyright © 2009 John Wiley & Sons, Ltd.
Soil Organic Matter Molecular Composition Shifts Driven by Forest Regrowth or Pasture after Slash-and-Burn of Amazon Forest

Slash-and-burn of Amazon Forest (AF) for pasture establishment has increased the occurrence of AF wildfires. Recent studies emphasize soil organic matter (SOM) molecular composition as a principal driver of post-fire forest regrowth and restoration of AF anti-wildfire ambience. Nevertheless, SOM chemical shifts caused by AF fires and post-fire vegetation are rarely investigated at a molecular level. We employed pyrolysis–gas chromatography–mass spectrometry to reveal molecular changes in SOM (0–10, 40–50 cm depth) of a slash-burn-and-20-month-regrowth AF (BAF) and a 23-year Brachiaria pasture post-AF fire (BRA) site compared to native AF (NAF). In BAF (0–10 cm), increased abundance of unspecific aromatic compounds (UACs), polycyclic aromatic hydrocarbons (PAHs) and lipids (Lip) coupled with a depletion of polysaccharides (Pol) revealed strong lingering effects of fire on SOM. This occurs despite fresh litter deposition on soil, suggesting SOM minimal recovery and toxicity to microorganisms. Accumulation of recalcitrant compounds and slow decomposition of fresh forest material may explain the higher carbon content in BAF (0–5 cm). In BRA, SOM was dominated by Brachiaria contributions. At 40–50 cm, alkyl and hydroaromatic compounds accumulated in BRA, whereas UACs accumulated in BAF. UACs and PAH compounds were abundant in NAF, possibly air-transported from BAF.
Identify Key Genes Correlated to Ischemia-Reperfusion Injury in Aging Livers

Background With the intensification of population aging, the proportion of aging livers in the donor pool is increasing rapidly. Compared with young livers, aging livers are more susceptible to ischemia-reperfusion injury (IRI) during liver transplantation, which greatly affects the utilization rate of aging livers. The potential risk factors associated with IRI in aging livers have not been fully elucidated. Methods In this work, five human liver tissue expression profiling datasets (GSE61260, GSE107037, GSE89632, GSE133815, and GSE151648) and a total of 28 young and aging liver tissues of human (N = 20) and mouse (N = 8) were used to screen and verify the potential risk factors associated with aging livers being more prone to IRI. DrugBank Online was used to screen drugs with potential to alleviate IRI in aging livers. Results The gene expression profile and immune cell composition between young and aging livers had significant differences. Among the differentially expressed genes, aryl hydrocarbon receptor nuclear translocator-like (ARNTL), BTG antiproliferation factor 2 (BTG2), C-X-C motif chemokine ligand 10 (CXCL10), chitinase 3-like 1 (CHI3L1), immediate early response 3 (IER3), Fos proto-oncogene, AP-1 transcription factor subunit (FOS), and peroxisome proliferative activated receptor, gamma, coactivator 1 alpha (PPARGC1A), mainly involved in the regulation of cell proliferation, metabolism, and inflammation, were also dysregulated in liver tissues suffered from IRI and could form a FOS-centered interaction network. Nadroparin was screened out with the potential to target FOS in DrugBank Online. In addition, the proportion of dendritic cells (DCs) was significantly upregulated in aging livers. Conclusions We combined the expression profiling datasets of liver tissues and samples collected in our hospital for the first time to reveal that the changes in the expression of ARNTL, BTG2, CXCL10, CHI3L1, IER3, FOS, and PPARGC1A and the proportion of dendritic cells may be associated with aging livers being more prone to IRI. Nadroparin may be used to mitigate IRI in aging livers by targeting FOS, and regulation of DC activity may also reduce IRI.
Internet follow-up can improve the compliance of sublingual immunotherapy in children with allergic rhinitis: a retrospective cohort study

Background Sublingual immunotherapy (SLIT) is an effective approach for treating allergic rhinitis in children. Although the curative effect of SLIT is significant, the compliance of patients is poor because of the long treatment time. How to improve patients’ compliance with SLIT is an important clinical problem faced by otolaryngology clinicians. At present, there are few studies on SLIT compliance. The present study aimed to analyze the related factors affecting SLIT compliance in children with allergic rhinitis (AR). Methods In total, 153 patients with AR who received SLIT were selected as the study objects. Seventeen patients were excluded from this study.The patients’ demographic, follow-up methods, complications efficacy, compliance data, etc. were collected, and all patients were followed-up regularly. Patients were considered to have poor compliance when they stop taking medication of SLIT. Univariate and multivariable regression analyses were performed to analyze the independent factors influencing SLIT compliance. The odds ratios (ORs) and 95% confidence intervals (CIs) were computed by logistic regression. Results A total of 136 patients were enrolled in this study. The baseline clinical factors of the two groups of follow-up methods were balanced and comparable. Among these, 35 patients (25.7%) ceased SLIT. There was a significant difference in compliance between the Internet follow-up group and the traditional follow-up group (P<0.001). Univariate logistic regression analysis showed that SLIT compliance was significantly related to residence (P<0.001), the caregiver’s education level (P<0.001), follow-up methods (P<0.001), and whether the patient also had asthma (P<0.002). In the multivariate regression analysis, it was found that the follow-up methods (OR =7.60, 95% CI: 2.20–26.21, P=0.001) and caregiver’s education level (OR =8.54, 95% CI: 3.04–23.95, P<0.001) were independent factors influencing SLIT compliance after adjusting for residence and whether the patient also had asthma. Conclusions Our study found that the follow-up methods and the education level of caregivers were independent factors affecting SLIT compliance in children with AR. This study suggested that we should use the Internet follow-up method for children treated with SLIT in the future, and provides a basis for how to improve the compliance of SLIT in children with AR.
Prediction in linear mixed models

Following estimation of effects from a linear mixed model, it is often useful to form predicted values for certain factor/variate combinations. The process has been well defined for linear models, but the introduction of random effects into the model means that a decision has to be made about the inclusion or exclusion of random model terms from the predictions. This paper discusses the interpretation of predictions formed including or excluding random terms. Four datasets are used to illustrate circumstances where different prediction strategies may be appropriate: in an orthogonal design, an unbalanced nested structure, a model with cubic smoothing spline terms and for kriging after spatial analysis. The examples also show the need for different weighting schemes that recognize nesting and aliasing during prediction, and the necessity of being able to detect inestimable predictions.
Robust H2 filtering of linear systems with time delays

The problem of robust H2 estimation of a combination of states of a stationary linear system with time delays is considered. Since the problem is infinite dimensional in nature, an attempt is being made to develop finite dimensional methods that will guarantee a preassigned estimation accuracy. The approach of minimizing the trace of a matrix that overbounds the exact covariance of the estimation error is considered. Sufficient conditions are given in the form of linear matrix inequalities (LMIs). The results are illustrated by a numerical example. Copyright © 2003 John Wiley & Sons, Ltd.