bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite switching near heteroclinic networks
Authors: Castro S B S D , Garrido-da-Silva L 
Published: October 2023

Abstract
We address the level of complexity that can be observed in the dynamics near a robust heteroclinic network. We show that infinite switching, which is a path towards chaos, does not exist near a heteroclinic network such that the eigenvalues of the Jacobian matrix at each node are all real. Furthermore, for a path starting at a node that belongs to more than one heteroclinic cycle, we find a bound for the number of such nodes that can exist in any such path. This constricted dynamics is in stark contrast with examples in the literature of heteroclinic networks such that the eigenvalues of the Jacobian matrix at one node are complex.
Deep learning based MLC aperture and monitor unit prediction as a warm start for breast VMAT optimisation
Authors: Vandewinckele L , Reynders T , Weltens C , Maes F , Crijns W 
Published: October 2023

Abstract

Objective. Automated treatment planning today is focussed on non-exact, two-step procedures. Firstly, dose–volume histograms (DVHs) or 3D dose distributions are predicted from the patient anatomy. Secondly, these are converted in multi-leaf collimator (MLC) apertures and monitor units (MUs) using a generic optimisation to obtain the final treatment plan. In contrast, we present a method to predict volumetric modulated arc therapy (VMAT) MLC apertures and MUs directly from patient anatomy using deep learning. The predicted plan is then provided as initialisation to the optimiser for fine-tuning. Approach. 148 patients (training: 101; validation: 23; test: 24), treated for right breast cancer, are replanned to obtain a homogeneous database of 3-arc VMAT plans (PTVBreast: 45.57 Gy; PTVBoost: 55.86 Gy) according to the clinical protocol, using RapidPlanTM with automatic optimisation and extended convergence mode (clinical workflow). Projections of the CT and contours are created along the beam’s eye view of all control points and given as input to a U-net type convolutional neural networks (CNN). The output are the MLC aperture and MU for all control points, from which a DICOM RTplan is built. This is imported and further optimised in the treatment planning system using automatic optimisation without convergence mode, with clinical PTV objectives and organs-at-risk (OAR) objectives based on the DVHs calculated from the imported plan (CNN workflow). Main results. Mean dose differences between the clinical and CNN workflow over the test set are 0.2 ± 0.5 Gy at D
95% and 0.6 ± 0.4 Gy at D
0.035cc of PTVBreast and −0.4 ± 0.3 Gy at D
95% and 0.7 ± 0.3 Gy at D
0.035cc of PTVBoost. For the OAR, they are −0.2 ± 0.2 Gy for D
mean,heart and 0.04 ± 0.8 Gy for D
mean,ipsilateral lung. The mean computation time is 60 and 25 min respectively. Significance. VMAT optimisation can be initialised by MLC apertures and MUs, directly predicted from patient anatomy using a CNN, reducing planning time with more than half while maintaining clinically acceptable plans. This procedure puts the planner in a supervising role over an AI-based treatment planning workflow.
The Precursor of GRB211211A: A Tide-induced Giant Quake?
Authors: Zhou Enping , Gao Yong , Zhou Yurui , Lai Xiaoyu , Shao Lijing , Wang Weiyang , Xiong Shaolin , Xu Renxin , Yi Shuxu , Yim Garvin , Yue Han , Zhang Zhen 
Published: October 2023

Abstract
The equilibrium configuration of a solid strange star in the final inspiral phase with another compact object is generally discussed, and the starquake-related issue is revisited, for a special purpose to understand the precursor emission of binary compact star merger events (e.g., that of GRB211211A). As the binary system inspirals inward due to gravitational wave radiation, the ellipticity of the solid strangeon star increases due to the growing tidal field of its compact companion. Elastic energy is hence accumulated during the inspiral stage which might trigger a starquake before the merger when the energy exceeds a critical value. The energy released during such starquakes is calculated and compared to the precursor observation of GRB211211A. The result shows that the energy might be insufficient for binary strangeon-star case unless the entire solid strangeon star shatters, and hence favors a black hole-strangeon star scenario for GRB211211A. The timescale of the precursor as well as the frequency of the observed quasi-periodic-oscillation have also been discussed in the starquake model.
Disturbance Observer-based Pointing Control of Leighton Chajnantor Telescope
Authors: Chen Weirui , Wang Zheng 
Published: October 2023

Abstract
Leighton Chajnantor Telescope (LCT), i.e., the former Caltech Submillimeter Observatory telescope, will be refurbished at the new site in Chajnantor Plateau, Chile in 2023. The environment of LCT will change significantly after its relocation, and the telescope will be exposed to large wind disturbances directly because its enclosure will be completely open during observation. The wind disturbance is expected to be a challenge for LCT’s pointing control since the existing control method cannot reject this disturbance very well. Therefore, it is very necessary to develop a new pointing control method with good capability of disturbance rejection. In this research, a disturbance observer—based composite position controller (DOB-CPC) is designed, in which an H∞ feedback controller is employed to compress the disturbance, and a feedforward linear quadratic regulator is employed to compensate the disturbance precisely based on the estimated disturbance signal. Moreover, a controller switching policy is adopted, which applies the proportional controller to the transient process to achieve a quick response and applies the DOB-CPC to the steady state to achieve a small position error. Numerical experiments are conducted to verify the good performance of the proposed pointing controller (i.e., DOB-CPC) for rejecting the disturbance acting on LCT.
Technical Feasibility Study for Development of Reference Material for Nitrate in Meat Product
Authors: de Oliveira M C , de Almeida M D , Osorio A C P , de Sena R C , Souza V 
Published: October 2023

Abstract
Nitrate measurement is a fundamental part of quality control in the meat products industries. Ensuring the technical validity of the results of these measurements can be achieved through the adoption of appropriate metrological tools such as reference materials. The technical feasibility for producing a nitrate reference material in a meat product was evaluated by preparing a batch of material on a small scale. The adequacy of the preparation procedure was evaluated by means of pertinent physicochemical and microbiological measurements. A batch of 175 units containing approximately 5 g of lyophilized cooked ham in each package was produced. The batch was submitted to preliminary studies to assess homogeneity and stability under transport conditions, in accordance with ISO 17034 and the applicable ISO guides.
A method to extend the calibration beyond the defined periodicity
Authors: Miqueleti S A , Costa-Félix R P 
Published: October 2023

Abstract
The assignment of calibration intervals shall be a formal process based on the results of previous calibrations. With the coronavirus pandemic, one means to avoid a non-conformity instrument and ensure an updated calibration program is to extend the calibration interval of laboratories equipment. The ILAC-G24 has published guidelines for that purpose. What can be done if an extension on the calibration validity is further than previously defined? This article presents a way to increase instrument uncertainty and extend the calibration period based on ISO Guide 35, applying a trend analysis and stability criteria of the reference material properties to the case of a measurement system.
Assessment of glycerol in biodiesel using an ultrasonic measurement method
Authors: Oliveira P A , Baesso R M , Alvarenga A V , Costa-Felix R P B 
Published: October 2023

Abstract
Biodiesel is a renewable fuel, biodegradable and alternative to diesel oil consisting chemically of fatty acid alkyl esters and obtained by the transesterification reaction. After transesterification, undesirable components may remain in biodiesel. The presence of these components negatively influences the properties and performance of biodiesel. This research aims to evaluate biodiesel quality, using the quantitative ultrasound technique to determine the presence of the contaminant glycerol in biodiesel samples. The blends used in this study consisted of biodiesel and glycerol varying from 0 % to 0.5 % of glycerol by mass. The measurement uncertainty was evaluated according to the Guide to the Expression of Uncertainty in Measurement. The speed of sound in biodiesel/glycerol blends was measured by the pulse-echo technique (@ 5 MHz) and was considered equivalent for the different concentrations studied. The maximum measurement uncertainty obtained was 2.2 m·s−1 (0.16 %).
Proposition of water meter for buildings based on a thin-film resistive sensor: electromechanical and thermal characterizations
Authors: Gonçalves L S , Medeiros K A R , Barbosa C R H 
Published: October 2023

Abstract
Notoriously, measurement proves to be essential to encourage water conservation. Thus, this work characterizes two thin-film resistive sensors (bend sensors) with different coatings aiming at their application to measure water consumption. For this, the individual water measurement system is presented and discussed briefly. Then, resistive sensor parameters and operating principles are detailed, as well as the mathematical formulation of the correlation of the sensor resistance with the flow velocity. Methodologically, the system developed for the electromechanical and thermal characterization of the sensor is presented. The results allowed obtaining a quadratic relationship between the sensor deflection angle and the resistance. Furthermore, it was observed that the polyester-coated sensor presented a low hysteresis value when subjected to temperature variation, obtaining a negative linear relationship between the sensor resistance and temperature. In turn, the polyimide-coated sensor did not show low hysteresis when exposed to temperature change and flexed at 50° and 70° angles. Finally, it is proposed for future work computer simulations and experimental tests to confirm the applicability of the sensor for water measurement.
Study on the reproducibility of the ice point realization at the Thermometry Laboratory of Inmetro
Authors: Pereira Neto M A , Diniz P H F , Torres A G , Oliveira A R , Quelhas K N 
Published: October 2023

Abstract
Despite being classified today as a secondary reference point of temperature, the ice point (0.0 °C) is still very important in many thermometry applications due to its simplicity, effectiveness, reproducibility and low cost. Uncertainties as low as some hundreds of microkelvin can be achieved, but it depends on the level of care of the experimental procedure practiced by the laboratory. The Thermometry Laboratory of Inmetro (Later) has adopted for a long time a conservative value available in literature for the uncertainty of the ice point. In order to reach more realistic results, in line with the specific equipment and experimental procedure of the lab, a study on the reproducibility of the ice point realization was conducted, enabling a significant reduction of the uncertainty previously adopted. In addition, from the uncertainty analysis performed, it was possible to show the great importance of the standardization of the ice bath preparation procedure for the achievement of better results.
The importance of proper storage of agar phantom on the water-glycerol-benzalkonium chloride mixture to maintain the ultrasonic group velocity
Authors: Souza R M , Costa-Félix R P B , Alvarenga A V 
Published: October 2023

Abstract
The present paper studied the metrological impact on the ultrasound group velocity in not storing the agar phantoms in the water-glycerol-benzalkonium chloride maintenance mixture. The ultrasonic velocity and the phantom’s thickness were measured by the pulse-echo technique seven times within 44 days, whereas four replicates were carried out under repeatability conditions. The phantom’s thickness did not differ statistically along the days since the normalized error was less than 1.0. Based on the results obtained, one can conclude that the ultrasound group velocity decreased in a logarithmic function along the days.
Validation of a Bovine Viral Diarrhea Virus (BVDV) absolute quantification method by digital droplet PCR (ddPCR).
Authors: Henrique M R F , Ramos-Júnior J L P , Flatschart R B , Barroso S P C , Heinemann M B , da Fonseca F G , Granjeiro J M , de Souza V , Folgueras-Flatchart A V 
Published: October 2023

Abstract
A increasingly common way for the diagnostics of viral agents is to carry out PCR from biological samples, which can detect their nucleic acid during the acute phase of the disease. Taking into account the need for quality control of PCR tests in laboratories accredited by ISO/IEC 17025:2017, we intend to carry out feasibility studies for the production of Reference Materials (MR) for these molecular tests, using BVDV in the matrix serum as a model. The first step for this goal was the validation of an analytical method for quantification of viral RNA to characterize the material under study. Primers and probe from a commercial qualitative assay kit designed for Real Time RT-PCR (VetMax Gold BVDV - Thermo Fisher) were used for quantification of BVDV by ddPCR. The technique was optimized and a Detection Limit of 13 copies/μL was determined, allowing a Quantification Limit of 38 copies/μL. The method showed to be linear over two orders of magnitude. The method will be used in the homogeneity study and long-term stability tests for the pilot batch of BVDV in Fetal Bovine Serum MR, a model for the production of MR intended for PCR of BVDV and other Flaviviridae.
Digital enhancement of OCT images toward better diagnostic of precursor cancer lesions in the uterine colon
Authors: Malinovski I , Couceiro I B , Alvarenga A D , Cordes A H , de Andrade C V , Russomano F B , von der Weid J P 
Published: October 2023

Abstract
We present a combination of image processing operations, which improve the quality of OCT images. The sequence is: (1) Gaussian blur, (2) Enhance Local Contrast (CLAHE), (3) FFT based band-pass filter, (4) Background Subtraction, (5) adjustment of the contrast of the image with light saturation (Enhance Contrast) and finally (6) reassignment of the palette such as to enhance the bright part of the images. The multi-step treatment reduces pixel-to-pixel noise, improves the homogeneity of the contrast, supresses vertical strips, reduces cosmetic distractions, equalizes contrast across a collection of images, and uses the pallet to emphasise areas of greater intensity. The enhanced images show a significant improvement in their quality, with details that do not appear in the original OCT image. The processing of these images and the comparison with untreated OCT images are shown throughout the paper.
Glass campanula effects on measurement results in high capacity mass comparator
Authors: Beatrici A. 
Published: October 2023

Abstract
The calibrations or checking of mass standards with nominal values greater than 10 kg and high accuracy class require special attention to the environmental conditions stability due to the their volume. The equipment used to calibrate this kind of mass standards usually has a weighing chamber (in this case a glass campanula or bell jar) to avoid, at least to reduce, the effects of environmental changes. In this study will be present the effects of these weighing campanulas on the standard deviations and in mass measurements results using only the internal tare (without weights in the balance plate) and using two 10 kg test weights.
Inmetro’s participation in SIM kilogram dissemination project (SKDP) Mass stability analysis of the SIM21 mass standard (1 kg) over three years in the SIM Kilogram Dissemination Project (SKDP)
Authors: Cacais F L , Loayza V M , Beatrici A , Quintão D , Rebelo A S 
Published: October 2023

Abstract
Inmetro’s mass laboratory (Lamas) participated in SIM Kilogram Dissemination Project (SKDP). The assessment of mass stability of the SIM21 1 kg stainless steel mass standard was carried out between 2018 and 2021. The results show a typical variability for a weighing system but not clear trend in measurements. Therefore one can say no mass drift for SIM21 mass standard was observed along this period.
A software to calibrate low-current meters in the range of picoamperes to microamperes
Authors: Pinto M V V , Ventura R V F , Landim R P , David R P 
Published: October 2023

Abstract
Among the main pillars of industry 4.0 are big data, artificial intelligence, and the industrial internet of things (IIoT) which, together with industrial automation, allow for significant operational advances. In the field of calibration, where processes and procedures must be standardized, automation diminishes the variability caused by human intervention. In addition, the process is no longer limited to the time the technician is present, speeding up deliveries and improving laboratory efficiency and productivity. In this work, a software for the calibration of low current meters is presented. Also, a mathematical model and uncertainty analysis related to the adopted calibration method is presented. It was possible to calibrate an electrometer in a fully automated way, with minimal intervention by the technician. This software was successfully validated through an intralaboratory comparison.
Bilateral comparison of dc voltage at 10 V between UTE and INMETRO
Authors: Slomovitz D , Landim R P , de Souza H , Trigo L 
Published: October 2023

Abstract
A bilateral comparison between the Instituto Nacional de Metrologia, Qualidade e Tecnología (INMETRO) and the Administración Nacional de Usinas y Trasmisiones Eléctricas (UTE) was performed during 2019 and 2020. The National Laboratory Standards used were two Josephson Voltage Standards at INMETRO (a CJVS and a PJVS), and a bank of multiple Zeners at UTE, both at 10 V level. The traveling standards were two commercial Zener based sources. The INMETRO was the pilot laboratory and the comparison error was (-1.79 ± 2.55) parts in 107, k=2.
Development of an upgraded E-field strength probe to be used as a transfer standard for metrological proposes
Authors: Mateus Sánchez Juan C. , Meng Donglin 
Published: October 2023

Abstract
This paper describes the development of an E-field strength sensor probe based on schottky diode technology to be used as a transfer standard for metrological proposes. This sensor probe was designed in a joint project between the National Metrology Institutes of Brazil (Inmetro) and China (NIM China) to bring traceability to many facilities generating E-field strength of both Institutes. The developed sensor allows transferring the E-field traceability from a μ-TEM Cell used as a primary standard to secondary standards like TEM and G-TEM Cells in the frequency range of 500 kHz to 2 GHz and at E-field intensities from 3 V/m to 70 V/m, with low uncertainty and a good dynamic range. The working principle of the new measuring system is similar to an old system that is not manufactured anymore, but it was re-designed in order to improve its performance and characteristics obtaining, as a result, a reduction in size of more than 10 times. Stability test results are also presented, showing that the new sensor is suitable for future inter-comparisons.
Review on Drone application methodologies in agriculture precision
Authors: Wadod Mohammed M. , Mohammed Faisel G. 
Published: October 2023

Abstract
In recent times, Drone use has increased significantly in the field of precise agriculture. These aircraft, which are equipped with thermal and multi-spectrum cameras, allow us to increase agricultural production in proportion to the increasing demand of the population and monitor crops grown in large areas, which is a very difficult task given the large areas of fields and the standards required for the successful cultivation of the crop in terms of soil moisture and fertility, proximity to water sources, and the possibility of its delivery In a way that reduces the waste of this water. Fields are at risk of crop damage due to diseases to crops caused by insects and pests, as drones can be used to spray pesticides and fertilizers in a way that reduces the health risks to people when spreading them manually. In this research paper, we will address several previous research related to the use of sensor and drone techniques in the field of precision agriculture and their efficiency in helping to sustain production and increase crop yields.
Principal Component Analysis of Selective Bands for Digital Satellite Imagery Classification
Authors: Al-Ani Laith A. , Mohammed Alyaa H. 
Published: October 2023

Abstract
Principal Component Analysis technique was applied to correlated multispectral data to convert it into uncorrelated data for the purpose of benefiting from its use in the automatic classification process.This project aims to classify multispectral satellite images using selective thematic Mapper (TM) spectral bands, and principal component (PC) images. The supervised classification method with maximum likelihood is adopted to perform the classification process.This technique was implemented using banding images and PC’s images. The results showed that the classification accuracy of the three spectral bands with the highest contrast was 86.9%, compared to the classification accuracy of the first three PC’s (89.08%). This value represents the highest classification accuracy obtained among the classification accuracy values for the spectral bands or PC images alone or in combination.
The results show the advantages of feature selection in the PC’s, for every value of n-components, the 1stprincipal is the best choice. Moreover at low values of n-PC’s contain more information about the discriminability of classes than for any combination of n-original spectral channels.
The Quantitative Morphometric Analysis of the Biggest Basin in Western Plateau of Iraq
Authors: Mohammed Maryam J. , Jawad Laith A. 
Published: October 2023

Abstract
The integrative utilization of the remotely sensed extracted data with geographic information system analyzing capabilities is the optimal approach to determine the shape of rivers and valleys basins realistically and to know their morphological and geomorphological characteristics, so it gives an accurate perception of ways to exploit surface or groundwater resources for these basins.
The concerned region is the western plateau which located between (38° 45’ 31˝) and (48° 17’ 12.58) eastern longitudes; (34 ° 30’ 10.77) and (29 0’ 38) northern latitudes. The hydrological analysis based on the geographic information system of the region basins showed that the Houran valley basin is the largest basin in the western plateau that described as a fourth-order drain basin that has dendritically and sometimes paralleled drain network.
The quantitative analysis of the morphological features showed that longitudinal drain density was 0.1698 km / km2, which reflects a soil quality with high permeability plus a desert climate of arid to semi-arid weather. The circulation ratio is 0.08566, which indicates that the basin is in an early geomorphological stage and that the linear structures control the pattern of its drainage network. The elongation ratio is 0.112, which means that there are significant differences in the hardness of its geological structure, and this would help the use of groundwater in the process of sustainable development of the region. The adoption of quantitative methods based on spatial analysis in hydrological studies supports the optimal use of water resources (from accurate identification of dam sites to realistic planning of irrigation projects), especially in areas with scarce water.