Experimental Measurement Methods Research Articles

Impending Collision Judgment from an Egocentric Perspective in Real and Virtual Environments: A Review.

The human egocentric perception of approaching objects and the related perceptual processes have been of interest to researchers for several decades. This article gives a literature review on numerous studies that investigated the phenomenon when an object approaches an observer (or the other way around) with the goal to single out factors that influence the perceptual process. A taxonomy of metrics is followed by a breakdown of different experimental measurement methods. Thereinafter, potential factors affecting the judgment of approaching objects are compiled and debated while divided into human factors (e.g., gender, age, and driving experience), compositional factors (e.g., approaching velocity, spatial distance, and observation time), and technical factors (e.g., field of view, stereoscopy, and display contrast). Experimental findings are collated, juxtaposed, and critically discussed. With virtual-reality devices having taken a tremendous developmental leap forward in the past few years, they have been able to gain ground in experimental research. Therefore, special attention in this article is also given to the perception of approaching objects in virtual environments and put in contrast to the perception in reality.

Magnetic properties and vibration characteristics of amorphous alloy strip and its combination

Although the cores made with amorphous metal alloy have lowered no-load losses compared with the orientation silicon steel cores, a high cost and noise level are inevitable because the magnetostriction for amorphous metal alloy strip is larger than the ordinary one. This study mainly focused on the experimental systems and methods for magnetic properties measurement, vibration characteristics and noise level of amorphous alloy strip and combinations. The vibration characteristics and noise level of amorphous alloy composite strip were also studied. The influence of the annealing process on magnetic energy, vibration characteristics and noise level of amorphous alloy core were analysed in detail as well. All the testing results and analysis above are helpful for the transformer manufacturers, and they can replace the expensive amorphous alloy metal strip with the combinations to reduce the noise and cost of the cores.

Experimental and Numerical Investigations of Pipeline with Resonator

Abstract This article presents the current state of the art regarding the use resonators in straight pipes. There is considerable need to control and reduce pressure pulsation in pipelines supplied with pulsating flows. The use of a Helmholz resonator introduces an additional degree of freedom to the analysed dynamic system. Building on previous experimental investigations by the authors, which identified the nonlinear properties of straight pipes supplied with pulsating flows, this study describes an experimental test rig, measurement methods and mechanical analogies for one (1DOF) and two (2DOF) degrees of freedom. The results are presented in the form of a 3D map of amplitude-frequency characteristics, as a function of the resonator volume determined by piston height. The dynamic properties of the described system are presented as amplitude-phase characteristics, based on a comparison of the numerical and experimental results.

Electric field modulation of energy transfer along intermediate filaments isolated from porcine retina

We report an experimental method for simultaneous measurement of the electric properties and energy transfer by natural biological fibers. We found that energy transfer efficiency along intermediate filaments (IFs) isolated from porcine retina varied with the potential difference applied to these IFs. The maximum measured effect amounted to 25% of the transfer efficiency increase. The recorded I/U plots characteristic of the IFs demonstrate the behavior of a semiconductor with 0.62 eV band gap. These results show that the image signal might be modulated by the potential difference across the cell membrane, facilitating image contrast enhancement in the brain.

Experimental measurement and analysis methods of polycrystalline X-ray diffraction for lithium batteries

Experimental measurement and analysis methods of polycrystalline X-ray diffraction for lithium batteries

Influence of Burner Nozzle Parameters Analysis on the Aluminium Melting Process

The paper presents the results of the optimisation of burner nozzle diameters during the combustion of natural gas under the conditions of increasing oxygen concentrations in the oxidizer in aluminium melting processes in drum rotary furnaces. The optimisation of outlet nozzle diameters was performed employing the method of experimental measurements, the results of which can be used for aluminium melting in hearth furnaces. The measurements were carried out using an experimental upstream burner with 13.5 kW input power. The monitored oxygen concentrations in the oxidizer ranged from 21% to 50%. The measurements were performed and evaluated in two variations of the burner configuration (geometry). In the first study, the impact of the enriched oxidizer on the melting of aluminium ingots was evaluated with the defined diameter of the air nozzle, which resulted in a reduction of the aluminium charge melting time by 50% at 45.16% oxygen concentration in the oxidizer, thus achieving savings in the consumption of fuel used for melting. In the second study, the diameter was optimised depending on the combustion rate of the natural gas and oxidizer mixture. The optimisation of the nozzle parameters resulted in the reduction of the charge melting time by 23.66%, while the same 25% enriched oxidizer was used. With the rise of the enrichment level to 35%, further reduction by approximately 12% was observed. The measurement results prove considerable influence of the parameter (geometry) optimisation of the outlet nozzles and oxidizer enrichment. Appropriately selected parameters of the burner can contribute to achieving comparable results at a lower enrichment of the oxidizer. The obtained results demonstrate the intensification of the heat transfer in the current thermal aggregates. The research conclusions confirm that oxygen-enhanced combustion and modification of existing burners reduces the specific energy consumption on the process and reduces CO2 emissions.

Isosteric Heat: Comparative Study between Clausius–Clapeyron, CSK and Adsorption Calorimetry Methods

This work presents the calorimetric study of five adsorbents with different chemical and textural characteristics: MOF-199, MCM-41, SBA-15, activated carbon prepared from corn cob (GACKP) and graphite. These solids were used to establish the differences between isosteric heats evaluated by three different methods: Clausius–Clapeyron (C-C), Chakraborty, Saha and Koyama (CSK) and Adsorption Calorimetry (A-Cal). The textural characterization results show solids that have values of specific surface area between 2271 m2·g−1 for the MOF-199 and 5.2 m2·g−1 for the graphite. According to the results obtained for the isosteric heats for each sample, the magnitude varies depending on the coverage of the adsorbate and the textural characteristics of each adsorbent. Solids with an organized structure have isosteric heat values that are coincident among the three methods. Meanwhile, heterogeneous solids such as activated carbon values evaluated by the CKS and C-C have a high dispersion method regarding the adsorption calorimetry method. The results obtained show that the adsorption calorimetry, being a direct experimental measurement method, presents less dispersed data. At low quantities, the isosteric heat of nitrogen adsorption decreased in the order MOF-199, GACKP, MCM-41, SBA-15 and Graphite. The order for the isosteric heats values was coherent with the surface characteristics of each of the solids, especially with the pore size distribution. Finally, throughout the coverage examined in this work, the isosteric heats for nitrogen adsorption determined by adsorption calorimetry (A-Cal) were larger than the evaluated by C-C and CSK indirect methods of vaporization. According to the results, it is shown that the adsorption calorimetry allows values of the isosteric heats of adsorption with an error of less than 2% to be established and also reveals the complex nature of the heterogeneity or homogeneity of the adsorbent.

Soft-Acting, Noncontact Gripping Method for Ultrathin Wafers Using Distributed Bernoulli Principle

The handling of ultrathin wafers ( $ thickness) is a challenging task since these are among the thinnest and most fragile materials. This paper provides a soft-acting and noncontact gripping technology for ultrathin wafer based on the distributed Bernoulli principle, and also proposes an experimental measurement method for evaluating the performance. A distributed Bernoulli gripper for ultrathin wafers is designed, and the characteristics of the gripper are studied via theoretical analysis and experiments. Three performance indices for evaluating the properties of the soft gripping: deformation, vibration, and stress are presented. Through measurement experiments, the effects of the key operational parameters consisting of air flow rate and gap height on the performance indices are investigated. Based on the experimental data, the appropriate parameters settings are obtained. The comparison to present grippers reveals that the proposed gripping technology is superior in soft gripping thin and fragile materials. This paper provides guidance for implementing the distributed Bernoulli principle in practical applications of soft-acting and noncontact gripping for thin and fragile materials. Note to Practitioners —This research of developing a new soft-acting and noncontact gripper was motivated by the problem of gripping of fragile workpieces like ultrathin wafers. The traditional contact handling method often leads to defective products including cracks, contact contamination, or mechanical wears, and the existing Bernoulli gripper has the shortcoming of resulting in large deformation as the impact of center negative pressure force, and the collision of wafer onto the gripper as the sharp lifting force curve. In this paper, we propose a soft-acting and noncontact gripper for ultrathin wafer based on the distributed Bernoulli principle. A systematic approach which consists of modeling, measurement, and evaluation is provided for the gripping techniques. We present three performance indices for evaluating the characteristics of soft gripping, and experimentally study the effect of supply flow rate and the gap height on the performance of deformation, vibration, and stress in the thin and fragile wafers. It is found that an optimal value exists. We then verify the merit in gripping ultrathin wafers softly with a small deformation or stress via comparison with two Bernoulli grippers and a combined gripper. The new gripper plays an important role in handling thin and fragile materials.

Experimental Study of Adsorption Effects on Shale Permeability

CH4 adsorption plays an important role in the permeability evolution of unconventional gas reservoirs. In this paper, an experimental method for simultaneous measurement of rock adsorption and permeability has been developed. For this experimental method, the CH4 adsorption amounts were obtained using a volumetric method. The permeability was measured by considering gas diffusion from the reference chamber to the core sample, under the pressure difference. A set of adsorption-permeability experiments were conducted on shale samples from lower Silurian Longmaxi Formation in the Sichuan Basin. The experimental results show that both the adsorption and swelling behavior of shale can be well described by the Langmuir equation. The effects of adsorption on permeability are influenced by two factors: (1) adsorption-induced storage, which causes an incremental in apparent porosity, leading to a significant error in permeability measurement if true porosity is used; and (2) adsorption-induced swelling, which potentially closes the existing natural fractures and reduces the intrinsic permeability. The adsorption storage effects are more significant at low pressure and are influenced by the experimental configurations (ratio of chamber volume to pore volume). With the increase in adsorption-induced swelling strain, the permeability declines by a cubic function during the adsorption process. Since swelling strain is linearly proportional to the amount of CH4 adsorbed, the behaviors of permeability and the amount of adsorbing gas follow similar trends.

Measurement of radiation heat transfer in supercritical carbon dioxide medium

In this work, a novel experimental method for measurement of radiation emitted by supercritical carbon dioxide (s-CO2) at high pressure and high temperature is presented. Due to high pressure conditions, use of conventional spectroscopic methods to measure radiative properties of s-CO2 is challenging. In the present method, supercritical conditions are created in a shock tube by using carbon dioxide (CO2) as the driven gas. The radiative emission by s-CO2 is measured using a platinum based thin film sensor. The total emissivity for s-CO2 is estimated and the value compares favourably with that predicted theoretically using a standard method available in literature. It is estimated that the total emissivity value of supercritical conditions is nearly 0.2 for the conditions studied, implying that s-CO2 acts as a participating medium for radiation heat transfer. The outcome of this study will have significant impact on the design of heat transfer equipment such as solar thermal receivers and heat exchangers typically used in s-CO2 based closed Brayton cycle, for which participating medium radiation heat transfer has been neglected traditionally.

COMPETENCY CONCEPTS ANALYSIS IN THE SYSTEM OF COMPUTER MODELING OF EDUCATIONAL TASKS

The article discusses the necessity of creating competency based tasks for computer educational models. This requires clarification of competency concept as well as the methods of its measurement. Several approaches to understanding competency and its definition have been analyzed. It is obvious that the majority of those do not describe development of measurement instruments for competency levels. Some of the discussed approaches make it possible to split the competency into separate components and consider the activities leading to upgraded competencies. The author provides definitions of competency and competency level. Competency is a mental construct which is a certain unity of a person’s skills required within definite context of activity for a definite set of possible tasks. Competency always describes “unity of two” – 1) set of tasks in the context; 2) the performer. Competency level is an index, characterizing the probability of successful performing of the task (on the given level) out of a definite set (variety) of tasks in the defined context by the definite performer. The experimental and indirect methods of competency measurement have been described. It is possible to view the construction of the competency from two different points: which parts (ingredients) and which components it includes. Parts (ingredients) are knowledge, skills, behaviours, attitudes, etc. Components are minor competencies aimed to solve minor auxiliary tasks. Thus, in order to solve a competency task it is necessary to solve a few easier tasks which would complete some zones of competency. The proposed approach describes the theory of competency level and structure measurement being a basis for competencies forming management. The mentioned approach requires more detailed development which is viewed as the matter of further research and publications.

ANTI-INFLAMMATORY ACTIVITY OF BAWANG DAYAK (ELEUTHERINE BULBOSA (MILL. URB.))ETHANOL BULB EXTRACTS

Background: Inflammation is a normal process in response to injury, but causes problems for the patient, including the appearance of pain, swelling, or fever. Anti-inflammatory agents generally used for those conditions, have several side effects to patients. Purpose: The objective of this research was to find alternative anti-inflammatory agents, especially from natural sources. Eleutherine bulbosa (Mill.) Urb. knew as “Bawang Dayak” belong to family Iridaceae is one of the natural sources for anti-inflammatory agents. This plant is known as traditional medicine in East Kalimantan and used as material in this research. Method: The experimental method of anti-inflammatory measurement using membrane stabilization activity for E. Bulbosa ethanol bulbs extracts. Result: The results showed that significant differences of EC50(p < 0.05) were achieved between indomethacin (26.39 ± 2.91) as the positive control with E. Bulbosa (52.87 ± 2.29). EC50 of E. bulbosa showed the potential anti-inflammatory activities with similar effectiveness to half indomethacin concentration. Conclusion: It could be concluded that E. bulbosa could be further developed as a new natural source of the anti-inflammatory agents.

The Effectiveness of Proposed Consensual Exercises to Correct the Error Associated with the Performance of the Layup Scoring Skill of Beginner's Basketball

The use of harmonized exercises in learning locomotives has an effective effect in the educational process because of its benefits. It remains in great need for the teacher and the good coach as it is assigned to perform its task well. Despite the many studies that specialized in teaching scoring through a few exercises, Of studies have used these harmonics exercises in the teaching of basic basketball skills, which may help to accelerate the process of learning as a result of short time and the construction of a true motor perception. The researchers used the experimental method of tribal measurement and telemetry to suit the nature of research.

Experimental Device for Monitoring Dentists’ Posture during Work

Abstract Despite the long term efforts, the muscular-skeletal injuries are still a major issue for the society. Several studies indicated a close relationship with the professional factors. Dental medicine characterized by its technical and technological specificity, especially strains the muscular-skeletal system, mainly the vertebral axis and the upper limbs. The present research aims at examining the dentists’ posture during their work using an experimental and original measurement method of the body position.

Experimental Study of Laminar Cooling Process on Temperature Field of the Heavy Plate

Laminar cooling is the key to hot rolling and controlled cooling. It can improve the performance of steel by changing the grain transformation. The key to improve product quality is that the laminar cooling process model can calculate the cooling strategy accurately. The conventional empirical formula calculation method can’t guarantee the accuracy of the water cooling heat transfer coefficient, which is the critical parameters of laminar cooling process. Therefore, an experimental study like this is needed. In this paper, the temperature measurement experiment of laminar cooling is carried out by the method of experimental temperature measurement. The experimental design stage uses COMSOL software to simulate the temperature field temperature to determine the diameter and depth of the measurement. Then the laminar cooling experiment is carried out and collects the temperature measurement data under different conditions. The error of the measured temperature field is less than 0.1% under the final experimental conditions. The heat transfer coefficient is obtained by experimental data and input in heat transfer model, the surface temperature is calculated, and the temperature is compared with the experimental data, the relative error is less than 20°C.

Experimental Measurement Method for Contact Stress of Elastic Metal Sealing Ring Based on Pressure Sensitive Paper

As a basic mechanical component, the sealing ring is widely used in industrial, aerospatial, and other fields. In this study, an elastic metal C-shaped sealing ring with a wave structure was taken as an example, and its performance was analyzed theoretically and measured experimentally. First, an experimental study was performed on the C-ring seal. The proposed method for experimental measurement of the contact stress of the C-ring seal involved innovative use of a universal electronic testing machine and pressure sensitive paper, in conjunction with the hue–saturation–brightness (HSB) method. Based on the discoloration of the pressure sensitive paper after contact stress, computer software was used for analysis, the discoloration was digitized, and the contact stress was established. Second, a theoretical calculation model of the C-ring seal was established using ANSYS software, and a finite element theoretical calculation of the mechanical properties of the sealing ring was established. Finally, the contact stress results were compared with the model calculation results of the C-ring seal. The error between the two was small (4.8%), which proved the validity of the calculation model and the scientificity of the experimental method.

Study on experiment measurement method of braking force of muzzle brake for vibration analysis

The braking force of the muzzle brake affects not only the strength of the connection thread of the muzzle brake, but also the vibration response of the artillery structure. Due to the complex formation process of the braking force of the muzzle brake, the current theoretical calculation method is used to estimate. This paper presents an experimental measurement method for artillery force of muzzle brake, which describes the measurement principle and deduces the calculation formula. The small-caliber cannon with muzzle brake is selected as the test object. A verification shooting experiment is carried out to obtain the size of the artillery force of the muzzle brake. The measurement values of the artillery force are basically consistent with the theoretical ones. The measurement method and principle introduced in this paper can be applied in the actual artillery force measurement of the muzzle brake. In this paper, the strain measurement principle is used to complete the experimental test of the braking force of the muzzle brake. This paper innovatively proposes a new method for testing the braking force, which has the advantages of simple operation, no need to manufacture special tooling, and low cost.

A detailed research for determination of Bi/Ga partial substitution effect in Bi-2212 superconducting matrix on crucial characteristic features

This multidisciplinary study paves way to investigate the crucial of fundamental characteristic properties including the bulk density, electrical, superconducting, flux pinning mechanism, crystal structure quality and strength quality of interaction between the superconducting grains in the Bi2.1Sr2.0Ca1.1Cu2.0Oy (Bi-2212) superconducting materials with the partial replacement of gallium foreign impurity by bismuth nanoparticles in the crystal structure. Characterizations of polycrystalline ceramic materials prepared by standard ceramic route in the atmospheric air are performed by means of conventional experimental measurement methods such as powder X-ray diffraction, Archimedes water displacement, dc electrical resistivity versus temperature and critical current density examinations. All the bulk Bi-site Ga partial replaced materials exhibit the Bi-2212 superconducting phase within the different fraction levels (%73.1–94.8), moderate self-field critical current densities 54–96 A/cm2 and wide-ranging offset and onset critical transition temperature range of 45.65 K–84.52 K and 70.06 K-85.00 K. As for the experimental findings of bulk density and related degrees of granularity (porosity) parameters, the bulk density parameter is found to be between 5.76 g/cm3 and 6.12 g/cm3 when the corresponding residual porosity value is also obtained to be in a range of 8.57 %–2.86%. Moreover, the mobile hole carrier concentrations in the short-range-ordered antiferromagnetic CuO2 layers are found to be in the range from 0.085 until 0.152. Additionally, the role of Ga/Bi partial substitution in the crystal lattice on the normal state resistivity, residual resistivity, residual resistivity ratio, vibrational mode intensities, texturing, superconducting volume fractions, mobile hole carrier concentrations, average crystallite sizes, Lotgering indices and cell parameters are discussed in details. All the experimental results and theoretical approaches show that the characteristic properties tend to improve regularly with the increment in the Ga foreign impurity level until x = 0.05 due to the increment in the crystal structure quality and interaction between the superconducting grains. After the critical Ga/Bi substitution level of x = 0.05, every feature degrades considerably.

Energy Dissipated in Tapping Mode Atomic Force Microscopes due to Humidity

Phase imaging is an important imaging model of atomic force microscopes (AFMs). It provides many sample properties that the height image does not. The phase information reflects the energy dissipation of the probe and sample interactions. Therefore, the energy dissipation between the tip and sample in the tapping mode is of great significance for understanding the mechanism of phase imaging experimentally and theoretically. In this paper, we propose a new method for measuring energy dissipation in tapping mode AFMs. The formation and rupture processes of liquid bridges are studied by this method. Finally, the experimental results are compared with the theoretical model. The comparison shows that the method of experimental measurement and the formation mechanism of liquid bridges in the tapping mode are reliable.

Experimental Demonstration of a 0.34-THz Backward-Wave Oscillator With a Sinusoidally Corrugated Slow-Wave Structure

The design and experimental demonstration of a 0.34-THz backward-wave oscillator (BWO) with a sinusoidally corrugated circular waveguide is presented. The dimensions of the sinusoidally corrugated structure are at the submillimeter scale. Particle-in-cell simulations have predicted that this miniature slow-wave structure (SWS) should be capable of 0.34-THz radiation. The miniature SWS was successfully fabricated using high precision computer numerical control machining and electric discharge machining. In experimental tests, the resulting BWO produced pulse radiation with a peak RF power of ~600 kW and a pulsewidth of 1.66 ns when driven by a 100-kV, 900-A weakly relativistic electron beam. The measured frequency was in the range of 0.32–0.36 THz and the device achieved stable operation at a pulse repetition rate of 10 Hz. We describe the experimental measurement methods of pulsewidth, frequency, and power for the high-power nanosecond terahertz signal. The work is a proof-of-principle demonstration of BWO frequency extension to above 300 GHz through structure miniaturization and precision machining.