Method For Direct Measurement Research Articles

Studying Interstellar Turbulence Driving Scales Using the Bispectrum

We demonstrate the utility of the bispectrum, the Fourier three-point correlation function, for studying driving scales of magnetohydrodynamic (MHD) turbulence in the interstellar medium. We calculate the bispectrum by implementing a parallelized Monte Carlo direct measurement method, which we have made publicly available. In previous works, the bispectrum has been used to identify nonlinear scaling correlations and break degeneracies in lower-order statistics like the power spectrum. We find that the bicoherence, a related statistic which measures phase coupling of Fourier modes, identifies turbulence-driving scales using density and column density fields. In particular, it shows that the driving scale is phase-coupled to scales present in the turbulent cascade. We also find that the presence of an ordered magnetic field at large scales enhances phase coupling as compared to a pure hydrodynamic case. We therefore suggest the bispectrum and bicoherence as tools for searching for non-locality for wave interactions in MHD turbulence.

Towards the next generation of CERN radiation monitoring front end ASICs

Radiation monitoring using ionisation chambers spans a wide spectrum of radiation fields from environmental monitors to ambient dose monitors near particle accelerators. Hence the output generated by these sensors can vary from few femtoamperes to microamperes. They require specific front-end electronics that can accurately measure the generated current across a wide dynamic range. This work presents the design of an ASIC that can measure currents from −6 fA to −20 μA without any band switching. By employing two different current measurement methodologies — direct slope measurement method and charge balancing based current to frequency converter method, an accuracy of ±6% is achieved across the entire measurement range. The ASIC was fabricated in the 8 inch fab of TSMC 130 nm technology. The designed ASIC aims to replace the front end electronics of radiation monitors at CERN.

Estimation methods to define reference evapotranspiration: a comparative perspective

Abstract Evapotranspiration is a key variable for hydrologic, climatic, agricultural, and environmental studies. Given the non-availability of economically and technically easy to implement direct measurement methods, evapotranspiration is estimated primarily through the application of empirical and regression models, and machine learning algorithms that incorporate conventional meteorological variables. While the FAO-56 Penman-Monteith equation worldwide has been recognized as the most accurate equation to estimate the reference evapotranspiration (ETo), the number of required climatic variables makes its application questionable for regions with limited ground-based climate data. This note provides a summary of empirical and semi-empirical equations linked to its data requirement and the problems associated with these models (transferability and data quality), an overview of regression models, the potential of machine learning algorithms in regression tasks, trends of reference evapotranspiration studies, and some recommendations of the topics future research should address that would lead to a further improvement of the performance and generalization of the available models. The terminology used in this note is consistent in both the theoretical and practical field of evapotranspiration, which is often dispersed in the academic literature. The goal of this note is to provide some perspective to stimulate discussion.

Monitoring the Geometry of Tall Objects in Energy Industry

The landscape shaped by the energy industry is rich in various slender structures, such as smokestacks, cooling towers, and others. It is thus becoming increasingly important to effectively monitor the geometrical condition of all types of such structures. Slender structures are deformed elastically under loads due to wind. A proper analysis of the changes and deformations of such structures requires a continuous ground-based measurement system which allows the movement of the structure to be measured in two horizontal directions, from a significant distance and with a possibly reduced number of stations. For this purpose, two methods were implemented: a linear terrestrial laser scanning method (TLS) and an optical, direct distance measurement method—tachymetry (TCH). The least squares method was used to fit rings on various levels of the structure and then the centers of the rings were identified. The comparison of the identified ring centers enabled the axis of the structure to be measured for deviation in two perpendicular directions. The methods were verified on actual structures: a smokestack 110 m in height, a cooling tower 60 m in height, and a wind turbine with the rotor axis at 149 m. The measurement results were compared with respect to the measurement time and the obtained accuracies at which the point locations were identified on the structure. The proposed methods are an effective tool for monitoring the condition of slender objects both during their operating life and after it. Regular monitoring of the geometric condition of slender structures in the energy industry limits the risk of major or catastrophic events, and as a result allows the safe and uninterrupted delivery of electric energy to clients.

The Measurement Uncertainty in Determining of Electrical Resistance Value by Applying Direct-Comparison Method

This paper considers the unknown electrical resistance (measurand) as the numerical result of the measurement that was carried out by means of the well-known direct comparison measurement method using an appropriate standard resistor and voltmeter. In the literature, this measurement method is also referred to as a series comparison method. This method of measurement is one of the indirect methods and is suitable for measuring low resistance. This paper presents two approaches for evaluating the unknown electrical resistance and its associated combined standard uncertainty. The entire process of evaluating the combined standard uncertainty that is associated with the measurand and the standard uncertainties that are associated with the analyzed input quantities has been entirely performed in accordance with the applicable international recommendations and guidelines for the uncertainty of measurement. The analyzed approaches for evaluating the combined standard uncertainty are designed to be universal and valid both for the mutually non-correlated input quantities and for the mutually correlated input quantities, which can be obtained from a single observation, or repeated observations or by other means. This paper can substantially contribute to the measurements in electrical engineering and education.

Preparation of Sb2Se3-based ceramics and glass-ceramics from native thin films deposited on Kapton foil

Amorphous Sb2Se3 thin films (200–1500 nm) deposited on Kapton foil were crystallized in controlled environment using the method of direct calorimetric measurement of thin films. X-ray diffraction was used to determine the intensity of the 1D (Sb4Sb6)n ribbons preferential orientation in dependence on the processing conditions: film thickness, energy flux during the pulsed laser deposition (PLD), heating rate, low and high temperature annealing. Lower PLD energy flux combined with higher deposited film thickness (1500 nm) led to increased orientation in the [2 2 1] direction, which is favorable for thin film solar cells application. Raman spectroscopy showed that thermally induced crystallization produces oxide-free Sb2Se3 thin films. Description of the crystallization kinetics led to very accurate kinetic predictions for the isothermal annealing conditions suitable for preparation of glass-ceramics with defined amount of crystalline phase – the predictions were accurate to ∼10% of the true (experimentally determined) value.

Development of a new high-precision friction test platform and experimental study of friction characteristics for pneumatic cylinders

In order to achieve high-precision pneumatic cylinder friction test, this paper proposes a new direct measurement method based on electric cylinder in which the axially acting forces from the compressed air in the two facing pneumatic cylinders cancel each other out and the detected value of the force transducer is just friction. For the sake of the implementation of the method, a new low-cost test method for identifying deadband of proportional directional valve was proposed, and a set of fuzzy PI constant pressure control system was designed to cope with a certain degree of leakage in the chamber. Based on the above, a friction test platform with two pneumatic cylinders facing each other was eventually built to study the influence of pressure, pressure difference, and piston speed on the friction of two commonly used different types of pneumatic cylinders. Through multiple sets of tests, it is found that when the lip seals are used in pairs between the piston and the inner wall of the cylinder, the friction between the piston and the cylinder is only related to the sum of the two chamber pressures, but not to the pressure difference between the two chambers. When the O-ring seal is used between the piston and the inner wall of the cylinder, the friction between the piston and the cylinder is related not only to the pressure of the two chambers, but also to the pressure difference between the two chambers. In addition, a series of comparative tests with the traditional single-cylinder friction test method directly demonstrate the effectiveness of the proposed new method.

Assessment of Cytotoxicity and Genotoxicity Potential of Effluents from Bahir Dar Tannery Using Allium cepa

Tannery effluent plays a significant role in increasing pollution in the environment; in particular, it contains toxic heavy metals which cause toxic effects on plant genetic materials. Among tannery effluent chemicals, chromium and lead have cytotoxicity and genotoxicity potentials on Allium cepa. This investigation was undertaken to assess the physicochemical properties of tannery wastewater and their effect on the genetic materials of A. cepa. Effluent’s physicochemical characteristics were investigated using digital instruments for direct measurement and standard methods of atomic absorption spectrophotometer colorimetric analysis. A series of six onion bulbs were grown in 0%, 20%, 40%, 60%, 80%, and 100% concentrations of wastewater (v/v) ratio, and root tips from each onion bulb were cut and processed for analysis by aceto-orcein squash technique. Most of effluent components were above the discharge limit standards set by Federal Environmental Protection Agency and Ethiopian Environmental Protection Authority. The cytotoxicity effect on the root growth showed a significant reduction at high concentration. Simple regression analysis showed that the results of mitotic index were statistically significant (P < 0.05) in different concentrations. A decrease in mitotic index with increasing concentration of the effluent was observed. The effluent had induced chromosomal abnormalities such as laggard, fragmentation, stickiness, bridge, micronucleus, and binucleated and morphologically changed nuclei in A. cepa root cells among others. The results showed that cytotoxicity, genotoxicity, and chromosomal aberrations were induced by the tannery effluent. Industries shall think of biological waste treatment methods.

A Method for Measuring Contact Points in Human-Object Interaction Utilizing Infrared Cameras.

This article presents a novel method for measuring contact points in human–object interaction. Research in multiple prehension-related fields, e.g., action planning, affordance, motor function, ergonomics, and robotic grasping, benefits from accurate and precise measurements of contact points between a subject’s hands and objects. During interaction, the subject’s hands occlude the contact points, which poses a major challenge for direct optical measurement methods. Our method solves the occlusion problem by exploiting thermal energy transfer from the subject’s hand to the object surface during interaction. After the interaction, we measure the heat emitted by the object surface with four high-resolution infrared cameras surrounding the object. A computer-vision algorithm detects the areas in the infrared images where the subject’s fingers have touched the object. A structured light 3D scanner produces a point cloud of the scene, which enables the localization of the object in relation to the infrared cameras. We then use the localization result to project the detected contact points from the infrared camera images to the surface of the 3D model of the object. Data collection with this method is fast, unobtrusive, contactless, markerless, and automated. The method enables accurate measurement of contact points in non-trivially complex objects. Furthermore, the method is extendable to measuring surface contact areas, or patches, instead of contact points. In this article, we present the method and sample grasp measurement results with publicly available objects.

Measurements of basal d-glucose transport through GLUT1 across the intact plasma membrane of isolated segments from single fast- and slow-twitch skeletal muscle fibres ofrat.

AimTo develop a method for direct measurement of the fluorescent d‐glucose analogue 2‐NBDG transport across the plasma membrane of single skeletal muscle fibres and derive the theoretical framework for determining the kinetic parameters for d‐glucose transport under basal conditions.MethodsA novel method is described for measuring free 2‐NBDG transport across plasma membrane of single rat muscle fibres at rest. The 2‐NBDG uptake was >90% suppressed by 100 µM cytochalasin B in both fast‐twitch and slow‐twitch fibres, indicating that the 2‐NBDG transport is GLUT‐mediated. Fibres were identified as fast‐twitch or slow‐twitch based on the differential sensitivity of their contractile apparatus to Sr2+.ResultsThe time course of 2‐NBDG uptake in the presence of 50 µM 2‐NBDG follows a one‐phase exponential plateau curve and is faster in fast‐twitch (rate constant 0.053 ± 0.0024 s‐1) than in slow‐twitch fibres (rate constant 0.031 ± 0.0021 s‐1). The rate constants were markedly reduced in the presence of 20 mM d‐glucose to 0.0082 ± 0.0004 s‐1 and 0.0056 ± 0.0002 s‐1 in fast‐twitch and slow‐twitch fibres respectively. 2‐NBDG transport was asymmetric, consistent with GLUT1 being the major functional GLUT isoform transporting 2‐NBDG in muscle fibres at rest. The parameters describing the transport kinetics for both 2‐NBDG and d‐glucose (dissociation constants, Michaelis–Menten constants, maximal rates of uptake and outflow) were calculated from the measurements made with 2‐NBDG.ConclusionFree 2‐NBDG and d‐glucose transport across the plasma membrane of single rat muscle fibres at rest is fast, conclusively showing that the rate‐limiting step in d‐glucose uptake in skeletal muscle is not necessarily the GLUT‐mediated transport of d‐glucose.

Evaluation of Sperm DNA Integrity by Mean Number of Sperm DNA Breaks Rather Than Sperm DNA Fragmentation Index.

Sperm DNA integrity is crucial for normal fertilization, implantation, and embryo development. Several assays are available to assess sperm DNA fragmentation but are limited by high price, complicated processes, and low accuracy. We developed a secondary amplification detection system based on terminal deoxynucleotidyl transferase and endonuclease IV, which could efficiently measure the number of 3'-OH (equivalent to the number of breakpoints). We applied this detection system in single stranded DNA with standard concentrations to obtain the standard curve. We then broke the double stranded genomic DNA by ultrasound and enzyme digestion and used the detection system to monitor the increase of DNA breakpoints. Finally, we used this method to measure the mean number of sperm DNA breakpoints (MDB) in 80 sperm samples. We successfully measured the number of 3'-OH in single stranded DNA with standard concentration and obtained the standard curve. The linear range for the number of DNA breakpoints was from 0.1 nM to 15 nM. The detection method was successfully validated on λ DNA and 80 human sperm samples. The results of real clinical samples revealed that the mean number of DNA breakpoints (MDB) had a stronger relevance with the sperm motility and clinical pregnancy outcomes than the commonly used parameter of DNA fragmentation index (DFI). We have developed a straight-forward method for direct measurement of the mean number of DNA breakpoints in sperms. The method has advantages of short time-consumption, simple operation, high analytical sensitivity, and low requirement for instrumentation, which makes it conducive to clinical application. The proposed new parameter (MDB) could be a more direct, accurate and clinically significant indicator for evaluating the sperm DNA integrity.

Simple Characterization Scheme for Optical Coherence Tomography Systems With Application to a Commercial and a Near-Isometric Resolution Fibre-Based System

Optical Coherence Tomography (OCT) is a rapidly growing imaging modality in biomedical optics. OCT can perform high-resolution, cross-sectional imaging of the microstructure of biological tissues by measuring the coherent spectrum from the backscattered light. OCT systems with broad spectral bandwidths are often constructed using free-space optics to avoid dispersion by fibre optic components. This paper presents a fibre-based OCT system at a centre wavelength of 1300 nm with an axial resolution of 3.8 µm in air, surpassing any previously reported values to the best of our knowledge. Despite the challenges in transporting a broadband spectrum using fibre-optics, the system investigation was motivated by the ever-increasing demand for commercialization of high-resolution OCT systems and simplification of construction. We also evaluate and demonstrate the direct measurement method for axial resolution using an air wedge. Imaging of biomedical and other samples is demonstrated using a high numerical aperture sample lens and compared with images from a commercial OCT system. We discuss the effect of the improved structural visibility by achieving image voxels closer to an isometric shape with a high NA sample lens.

The Effect Of Various Saturated Hydraulic Conductivity Of the Pitcher To Water Content In Sandy Loam Soil

Pitcher Irrigation is one of the artificial water supply techniques to overcome the lack of soil water content. The Pitcher Irrigation can save water so it is suitable for use on dry land. The research purposes was to determine the effect of various hydraulic conductivity of the picther on changes in soil water content around the pichter through program simulation. The methods used are direct measurement methods in the field and simulation methods. The measurement and simulation results are then calibrated with a solver and validated to obtain a small RMSE value and R2 was high. The results showed that the hydraulic conductivity of the picther had a significant effect on the soil water content. If the higher the hydraulic conductivity of the picther, the higher the water content around this pcther. And if the hydraulic conductivity of the picther is lower, the water content around the picther be lower. From the results of model validation, it can be said that the simulation program in this study is feasible to use because the value obtained R2 is 56.1%.

Telacebec: an investigational antibacterial for the treatment of tuberculosis (TB)

ABSTRACT Introduction Tuberculosis is an infectious disease that affected more than 50 million people and killed 6.7 million patients in the past 5 years alone. Additionally, rising incidence of treatment resistance threatens the global effort to eradicate this disease. With limited options available, additional novel antibiotics are needed for the treatment of multidrug-resistant tuberculosis (MDR-TB). Telacebec is a first-in-class antibiotic that targets the pathogen’s energy metabolism. Areas covered This paper provides an overview of the recent progress in the development and testing of telacebec. We discuss published clinical data and examine the design and setup of its clinical trials. We also offer insights on the therapeutic potential of telacebec and aspects of which should be evaluated in the future. Expert opinion The first phase 2a trial showed a correlation between dosage and bacterial load in patient sputum, which should be confirmed using a direct measurement method such as colony-forming unit counting. Its clinical efficacy, favorable pharmacokinetic properties, low arrhythmogenic risk, and activity against MDR-TB strains make telacebec a suitable candidate for further development. Future clinical testing in combination with approved second-line drugs will reveal its full potential against MDR-TB. Considering recent preclinical studies, we also recommend initiating clinical trials for Buruli ulcer and leprosy.

Catalase Activity in Hot-Air Dried Mango as an Indicator of Heat Exposure for Rapid Detection of Heat Stress

The growing market for dried fruits requires more attention to quality parameters. Mango and other tropical fruits are commonly dried at temperatures ranging from 40 °C to 80 °C. Convincing evidence suggests that the nutritional quality of dried fruits is best preserved when dried at low temperatures ≤50 °C, whereas increasing drying temperatures lead to the degradation of the most valuable nutrients inside the fruit. Currently, there is no system or direct measurement method that can assist in identifying the quality deterioration of dried fruits caused by excessive heat exposure during drying. From this perspective, the activity of the heat-sensitive enzyme ‘catalase’ was used for the first time to evaluate and compare mango slices dried at 40 °C, 60 °C and 80 °C. Various methods, including direct and indirect flotation tests and spectrophotometric measurements, were explored to measure the residual catalase activity in the dried samples. Results showed that the spectrophotometry and indirect flotation test produced the best results, revealing a significant difference (p < 0.05) in the catalase activity of mango slices dried at 40 °C, 60 °C and 80 °C, which the direct-dried mango flotation test failed to predict. Furthermore, this study demonstrates the potential applicability of catalase activity to indicate heat stress in dried mango slices processed at different temperatures.

Cover Image

The cover image is based on the Practice and Policy A novel computer‐aided method for direct measurements and visualization of gingival margin changes by Marko Kuralt et al., https://doi.org/10.1111/jcpe.13573. image

A comparative study of human glomerular basement membrane thickness using direct measurement and orthogonal intercept methods

IntroductionHere we report estimates of glomerular basement membrane (GBM) thickness in the Brazilian population performed using direct (DM) and orthogonal interception methods (OIM), and comment on potential sources of variation among estimates made by different laboratories.MethodologyA total of 38 patients, ranging from 3 to 78 years of age, 26 (68%) males and 12 (32%) females, were submitted to kidney biopsy procedures for renal disease diagnosis. Glomeruli were diagnosed with minor histological changes by conventional, immunofluorescence and electron microscopy. GBM thickness was estimated using both DM and OIM methods.ResultsEstimates of GBM thickness obtained using DM were higher than those obtained by OIM. However, the application of a correction for non-perpendicular membrane sectioning to DM estimates yielded similar results to those obtained under OIM. The estimated GMB thickness using DM after correction was 289 + 44 nm, versus 287 + 48 nm by OIM. No statistically significant differences were detected in GMB thickness, nor with respect to patient age or sex.ConclusionsGBM thickness in the studied Brazilian population measured approximately 290 nm. The application of criteria for estimating the shortest distance between the endothelial and podocyte cell membranes with correction for non-perpendicular membrane sectioning can increase the accuracy of GBM thickness estimates using DM and OIM.

Deformation and fracture behaviour of alumina-zirconia multi-material nanocomposites reinforced with graphene and carbon nanotubes

An effort to improve the low fracture toughness of monolithic alumina (Al2O3) ceramic demands microstructural manipulation with nanostructured materials such as zirconia (ZrO2), Graphene (GN) and Carbon Nanotubes (CNTs). Despite these attempts, the fundamental understanding of the mechanical properties and deformation behaviour of multiple combinations of these second-phase additives within the advanced Al2O3 structure are still being explored. In this respect, Al2O3-based nanocomposites reinforced with optimum amounts of ZrO2(10 wt%), GN(0.5 wt%) and CNTs(2 wt%) were evaluated via hot-pressing at 1600 °C, preceding colloidal mixing of the Al2O3 matrix and nanostructured additives. Mechanical properties such as fracture toughness (KIC) and bending strength (σf) measured using three-point bending techniques including single edge notched beam (SENB) test, and direct crack measurement (DCM) methods were calculated from the near-dense fabricated multi-material nanocomposites and benchmarked against the monolithic Al2O3 material under similar experimental conditions. From the conventional SENB test, the fracture toughness values increased by up to 60% on the addition of only 10 wt%ZrO2 to the monolithic Al2O3, whilst a drastic increase by up to 159% was achieved with the incorporation of both GN and CNTs within the Al2O3–ZrO2 structure, as compared to the monolithic Al2O3. The KIC values obtained from SENB tests were typically lower than the DCM method, but similar trend in the toughness behaviour were realized regardless. Bending strength of the prepared monolithic Al2O3 was also increased by up to 46% with the combined additions of ZrO2, GN and CNTs. Toughening and strengthening mechanisms including pull-outs by GN and CNTs, crack arrest and cack bridging were identified as the main source of enhancement in the mechanical properties of the multi-material nanocomposites. The addition of carbon additives also influenced monoclinic and tetragonal ZrO2 phase transformations, which also contributed to the overall mechanical behaviour of the Al2O3-10 wt%ZrO2 nanocomposites.

ЭКСПЕРТИЗА КАЧЕСТВА НАНОМАТЕРИАЛОВ ПРИ РАЗРАБОТКЕ И ПРИМЕНЕНИИ ОБОРОТНЫХ РЕСУРСОВ В СТРОИТЕЛЬСТВЕ

the advantage of the equality indicator is the relative simplicity of definition and the possibility of periodic moni-toring. According to the equality indicator, it is possible to assign repairs and predict the service life, assess the condition of the road surface. Experimental studies have proved that there is a connection between the evenness of the coating and the strength of the pavement, which opens up the possibility of determining the structural strength of non-rigid pavement, which provides a given evenness of the coating for the last year of operation be-fore major repairs. The question of assessing the impact of the unevenness of the road surface on the processes of development and accumulation of deformations, changes in the evenness of the coating during operation remain largely open. This is due to the multifactorial nature of the problem of predicting the equality of coverage, so it is advisable to use approaches based on direct measurement methods. Most of the existing models of interaction of a pneumatic or rigid wheel with a coating are designed for problems of pavement mechanics or car theory, therefore they cannot be unambiguously applied to determine the value of the dynamism coefficient. A significant disad-vantage of these solutions is insufficient consideration of the deformative properties (modulus of elasticity) of the pavement.

Measurement Uncertainty in Voltage Coefficients for Compressed-Gas Capacitor Based on a Simplified Tilting Method

High-voltage compressed-gas capacitor is a type of precision equipment commonly used in high voltage laboratories. The voltage dependence of capacitance, in other words, the voltage coefficient of capacitance, is an important factor to ensure the measurement accuracy of capacitors. The simplified tilting method derived from PTB, which provides a solution for measuring the voltage coefficient of the high-voltage capacitor with compressed-gas coaxial cylindrical electrodes structure. However, it is not an easy work for most laboratories. In order to evaluate the voltage coefficient based on the simplified tilting method, a special experimental platform was developed. The high-voltage capacitor installed on the platform can be tilted and rotated at high voltage and be remote-controlled. Base on the developed platform, the voltage coefficient of a 350 kV high-voltage capacitor was measured. In order to verify, it was re-measured by the direct measurement method with a dummy high-voltage capacitor, and before that, the voltage coefficient of the dummy capacitor was calibrated with a near zero-voltage-coefficient capacitor. The results show a good agreement, the consistency of the measurement results is better than 1.2×10^-6 between the two methods. Furthermore, the evaluation of measurement uncertainty in the voltage coefficient determination of capacitor based on simplified tilting method is introduced in detail. The evaluation results show that the expanded uncertainty is significantly better than 2.0×10^-6, k=2.