Unique Experimental Method Research Articles

A STUDY OF THE MATURITY PROCESS OF RED GUTTY KETAN FOOD INGREDIENTS IN TERMS OF THE TASTE: EXTREMELY LOW FREQUENCY MAGNETIC FIELD RADIATION

This study explores the novel effect of an Extremely Low Frequency (ELF) magnetic field on the durability of glutinous tape food, a traditional Indonesian food made from fermented glutinous rice. ELF magnetic field is a spectrum of electromagnetic waves with frequencies less than 300 Hz that can influence microbial activity and the chemical changes in food. The study uses a unique experimental method that exposes 20 glutinous tape samples, divided into a control group and an experimental group, each with 10 samples, to an ELF magnetic field of 1,000μT intensity for 45 minutes. The study uses a Complete Randomized Design (RAL) and analyzes the data using the One Way Anova test with LSD and Kruskal-Wallis tests using IBM SPSS Statistics 23. The results show that the experimental group’s glutinous tape samples did not experience spoilage compared to the control group’s. The study proves the ELF magnetic field's effect on the durability of glutinous tape food and provides insights for developing new food preservation techniques. The study demonstrates the innovation and applicability of using the ELF magnetic field for food durability.

THE IMPACT OF LOW-FREQUENCY MAGNETIC FIELD ON KETAN TAPE MATURATION: pH, DENSITY, AND TASTE

This study explores the novel effect of Extremely Low Frequency (ELF) electromagnetic waves on the fermentation process of sticky rice tape, a traditional Indonesian food made from glutinous rice. ELF electromagnetic waves are waves consisting of magnetic fields and electric fields that do not require intermediaries in their propagation and have frequencies ranging from 0-300 Hz. The study uses a unique experimental method that exposes 2 kg of sticky rice tape, divided into 10 control and 10 experimental samples, each weighing 100 grams and wrapped in ziplock plastic, to ELF electromagnetic waves for two days. The study uses a device that generates ELF electromagnetic waves with a certain intensity and frequency. The study measures the changes in the pH, density, and taste of the sticky rice tape samples after the exposure. The results show that the experimental group’s sticky rice tape had a higher pH, higher density, and sweeter taste than the control group’s sticky rice tape. The study proves the effect of ELF electromagnetic waves on the fermentation process of sticky rice tape and provides insights for the development of new food processing techniques. The study demonstrates the applicability and innovation of using ELF electromagnetic waves for food fermentation.

A study on the sparking distance in the electrochemical discharging process

The electrostatic force affects the gas film formation and collapsing in the electrochemical discharge process. Experimental observation of the process using a side insulated tool shows that the gas bubble will collapse or depart from the tooltip at the removal of electrostatic force. This study investigates the relationship between the electrostatic force and the sparking distance. A unique experimental method is developed in this study to establish the distance of sparking. Within this distance the electrostatic force can attract the electrolyte to the tool and result in a spark. A mathematical model is developed to predict the sparking distance under the influence of electrostatic force. Experimental verification of the model revealed that the sparking distance could be reduced by decreasing the tool size and lowering the applied voltage. The model was able to predict the trend of the average sparking distance with less than 5% variation. Electrolyte concentration has a minor effect on the sparking distance but affects the voltage range for sparking.

Magnetic field effects in non-magnetic luminescent materials: from organic semiconductors to halide perovskites

Magnetic field effects (MFEs) are used to describe the changes of the photophysical properties (including photoluminescence, electroluminescence, injectedcurrent, photocurrent, etc.) when materials and devices are subjected to the external magnetic field. The MFEs in non-magnetic luminescent materials and devices were first observed in organic semiconductor. In the past two decades, the effects have been studied extensively as an emerging physical phenomenon, and also used as a unique experimental method to explore the processes such as charge transport, carrier recombination, and spin polarization in organic semiconductors. Recent studies have found that the MFEs can also be observed in metal halide perovskites with strong spin-orbital coupling. Besides, for expanding the research domain of MFEs, these findings can also be utilized to study the physical mechanism in metal halide perovskites, and then provide an insight into the improving of the performance of perovskite devices. In this review, we focus on the magnetic field effects on the electroluminescence and photoluminescence changes of organic semiconductors and halide perovskites. We review the mainstream of theoretical models and representative experimental phenomena which have been found to date, and comparatively analyze the luminescence behaviors of organic semiconductors and halide perovskites under magnetic fields. It is expected that this review can provide some ideas for the research on the MFEs of organic semiconductors and halideperovskites, and contribute to the research of luminescence in organic materials and halideperovskites.

A forgotten technology: The production of artificial millstones for windmills in Sistan, southeastern Iran

The present study investigates for the first time a largely forgotten pyrotechnology for manufacturing artificial millstones for Persian windmills and querns from Islamic period Sistan, a region in southeastern Iran. The unusual characteristics of these materials result from melting a sand-clay mixture at high temperatures. A unique experimental and multianalytical method was developed to understand the heating-cooling regime for manufacturing artificial millstones and other technical details of their production. According to chemical and microstructural analyses, these materials were melted between 1150 °C and 1250 °C and kept there for a period of 14–20 h, to be subsequently cooled down by 10–50 °C/h. Our experimental results for reproducing the microstructure of these objects show that any other temperature regime would be unsuccessful for manufacturing a functional millstone for these huge windmills which are usually referred to as the first wind turbines in the history of technology.

Understanding near-surface polymer dynamics by a combination of grazing-incidence neutron scattering and virtual experiments.

Neutron spin-echo spectroscopy is a unique experimental method for the investigation of polymer dynamics. The combination of neutron spin-echo spectroscopy with grazing-incidence geometry (GINSES) opens the possibility to probe the dynamics of soft-matter materials in the vicinity of the solid substrate in the time range up to 100 ns. However, the usage of the GINSES technique has some peculiarities and, due to the novelty of the method and complexity of the scattering geometry, difficulties in further data analysis occur. The current work discusses how virtual experiments within the distorted-wave Born approximation using the BornAgain software can improve GINSES data treatment and aid the understanding of polymer dynamics in the vicinity of the solid surface. With two examples, poly(N-isopropyl acrylamide) brushes and poly(ethylene glycol) microgels on Si surfaces, the simulation as well as the application of the simulation to the GINSES data analysis are presented. The approach allowed a deeper insight to be gained of the background effect and scattering contribution of different layers.

Real-time visualization of impact damage in monolithic silicon carbide and fibrous silicon carbide ceramic composite

Impact resistance from foreign debris is a critical requirement for brittle ceramic and ceramic composite materials intended for use in the hot-section of gas turbine engines. A design to mitigate against such impact failures necessitates a detailed understanding of the driving failure mechanisms. The present study introduces a unique time-resolved experimental method which advances the latter effort. Specifically, a pulsed synchrotron X-ray source, in phase contrast imaging (PCI) configuration, is used as a medium, to visually characterize the evolution of damage inside the target materials during impact. As a proof of concept, two types of ceramic materials were tested: monolithic silicon carbide and fibrous silicon carbide composite. Impact was performed using a light-gas gun and 1.5 mm diameter spheres of partially stabilized zirconia (PSZ) and silicon nitride (Si3N4). The retrieved dynamic X-ray image sequences provided clear outlines of the damage features. In the case of the monolithic ceramic, the impact by a PSZ projectile initially produced a cone crack and complete failure resulted by extension of a median crack. By contrast, the fibrous composite deformed readily prior to cone crack formation. Nearly identical damage features were observed in the monolith for the Si3N4 projectile, with the exception of the added vertical tensile crack. For this same projectile, the fibrous ceramic showed very limited surface deformation and enhanced cone cracking and kinking of laminates along the crack path. The latter response is attributed to the change in projectile properties. Some of the target materials were recovered, and post-mortem analysis via scanning electron microscopy (SEM) showed correlation with observed X-ray damage profiles. Moreover, simple Hertzian contact was used to estimate damage for the elastic portion of impact. This approach was found to yield a reasonable match with experimental results for the surface displacement near the contact interface.

Effect of dynamic pseudo threshold pressure gradient on well production performance in low-permeability and tight oil reservoirs

Pseudo threshold pressure gradient (PTPG) is a significant parameter that characterizes fluid flow in low permeability and tight reservoirs, which would illustrate pressure derivative curves anomaly caused by low-velocity non-Darcy flow. During the development of low-permeability and tight reservoirs, PTPG is a dynamic parameter influenced by effective stress. A series of core flooding experiments have been conducted in this paper to conclude the relationship between effective stress and PTPG with the unique experimental method. In the experiment, the precision of pressure measurement is greatly improved by a novel device and the influence of the core-end effect and the defects of the core holder on the experimental results is eliminated. The results show that PTPG increase along with the increase of effective stress. Based on the conclusion, a dynamic PTPG model is established, and the corresponding parameters are derived by fitting the experimental data. The well performance of a vertical well estimated by this model shows the production rate and recovery factor of non-Darcy flow considering dynamic PTPG are smaller than that of Darcy flow but larger than that of conventional non-Darcy flow. The recovery factor of non-Darcy flow considering dynamic PTPG is 21.2% higher than that of conventional non-Darcy flow when the production time is 800 days. The production rate and recovery factor curves of different overburden pressure show that the higher the overburden pressure is, the worse the productivity of the well is. The recovery factor at an overburden pressure of 50 MPa is 11.1% lower than that at an overburden pressure of 30 MPa.

A Universal Dynamic Inflation Test for Soft Tissue, Tissue Analogues and Grafts

This paper presents a new dynamic inflation experiment method for identifying the viscoelastic parameters of blood vessels and grafts. The material parameters are estimated only from the recorded damped natural pressure oscillation and from the initial geometry of the tested specimens. The identified parameters are dynamic compliance, the damping ratio, fictitious fluid viscosity, frequency, and, for tubular samples, the elastic incremental modulus and the wall viscosity. Several experiments with latex tubular samples were performed to check the suitability of this unique experimental method, and to estimate the limits of its applicability (effects of operational parameters, e.g. the geometry of the samples and the viscosity of the working fluids).

Risk aversion in crop insurance program purchase decisions

PurposeThe purpose of this paper is to contribute to the aforementioned literature on the linkage between economic activity and human preference by estimating the cross-sectional determinants of farmers’ participation in participation in crop insurance programs (CIPs) and identifying the impediments preventing the remaining farmers from participating.Design/methodology/approachUsing the unique data sets of risk preference experiments and maize producer surveys pertaining to the maize production areas of China, this paper explores the determinants of farmers’ CIPs and scrutinizes the role of risk aversion in farmers’ CIP purchase decisions under the expected utility maximization framework. And a “non-zero threshold probit model” is used for the analysis.FindingsThe results show that risk aversion plays an important role in CIP purchase decision-making, not only in the form of its direct effect but also with regard to the interaction term and expected loss. Furthermore, if the insured amount is high enough, then risk aversion will no longer affect insurance purchase. Additionally, purchase experience, CIP environment (village purchase ratio), and contract items (insured amounts) are significant determinates in these decisions. There is no significant evidence to suggest that serious adverse selection exists in the sampling areas.Originality/valueOne theoretical model is established which considered not only general variables like farmers’ production and household information, but also conditions and terms in the insurance policies. The unique experimental method is used to measure farmers’ risk aversion. Both the role of risk aversion and its’ interaction terms with others in CIP participation are scrutinized to identify complicated influences under the context of real society.

Multistable perception of ambiguous melodies and the role of musical expertise.

Whereas visual demonstrations of multistability are ubiquitous, there are few auditory examples. The purpose of the current study was to determine whether simultaneously presented melodies, such as underlie the scale illusion [Deutsch (1975). J. Acoust. Soc. Am. 57(5), 1156-1160], can elicit multiple mutually exclusive percepts, and whether reported perceptions are mediated by musical expertise. Participants listened to target melodies and reported whether the target was embedded in subsequent test melodies. Target sequences were created such that they would only be heard if the listener interpreted the test melody according to various perceptual cues. Critically, and in contrast with previous examinations of the scale illusion, an objective measure of target detection was obtained by including target-absent test melodies. As a result, listeners could reliably identify target sequences from different perceptual organizations when presented with the same test melody on different trials. This result demonstrates an ability to alternate between mutually exclusive percepts of an unchanged stimulus. However, only perceptual organizations consistent with frequency and spatial cues were available and musical expertise did mediate target detection, limiting the organizations available to non-musicians. The current study provides the first known demonstration of auditory multistability using simultaneously presented melodies and provides a unique experimental method for measuring auditory perceptual competition.

Isochronicity corrections for isochronous mass measurements at the HIRFL-CSRe

Isochronous Mass Spectrometry (IMS) is a unique experimental method for mass measurement experiments on short-lived nuclei. Mass measurements of 78Kr projectile fragments were performed in HIRFL-CSRe at the Institute of Modern Physics (IMP), Chinese Academy of Sciences. The short-lived secondary beams were produced by bombarding a 15mm thick beryllium-target in the Radioactive Ion Beam Line (RIBLL2) and were then injected into the CSRe storage ring. The masses of stored ions were measured by employing the IMS technique, which is based on the determination of the ion revolution times. A dedicated time-of-flight (TOF) detector is used for the latter purpose. However, the isochronicity, and thus the mass resolving power, depends on the momentum spread and the transverse emittance of the injected beams, Here, we present the first-order isochronicity optimization, the chromaticity and second-order isochronicity corrections through the modification of the quadrupole and sextupole field strengths. With the help of these corrections, the mass resolution of Δm/m=10−6 can be achieved.

Thoracolumbar spinal ligaments exhibit negative and transverse pre-strain

The present work represents the first reported bi-axial spinal ligament pre-strain data for the thoracic and lumbar spine. Ligament pre-strain (in-situ strain) is known to significantly alter joint biomechanics. However, there is currently a lack of comprehensive data with regards to spinal ligament pre-strain. The current work determined the pre-strain of 71 spinal ligaments (30 anterior longitudinal ligaments, 27 supraspinous ligaments and 14 interspinous ligaments). The interspinous ligament and the anterior longitudinal ligament exhibited bi-axial pre-strain distributions, demonstrating they are not uniaxial structures. The supraspinous ligament frequently exhibited large amounts of negative pre-strain or laxity suggesting it makes no mechanical contribution to spinal stability near the neutral posture. Upon implementing multi-axial pre-strain results into a finite element model of the lumbar spine, large differences in spinal biomechanics were observed. These results demonstrate the necessity of accounting for ligament pre-strain in biomechanical models. In addition, the authors present a unique experimental method for obtaining ligament pre-strain that presents a number of advantages when compared to standard techniques.

The Effect of Homework on Exam Performance: Experimental Results from Principles of Economics

We assess the effect of the completion of online homework assignments on exam performance in “Principles of Economics” using a unique experimental method. For specific homework assignments we randomize students into two groups: those for whom the assignment is optional and those for whom it is required. This randomization, which affects incentives to complete the homework assignment for a particular topic, generates an instrument that helps identify the effect of homework completion on topic‐specific exam performance. Results of the instrumental variables analysis, as well as results of a variety of other analyses, indicate that the completion of the assigned homework is positively (if not always significantly) correlated with higher scores on the midterms but not on the final exam—indicating “decay” in the homework effect over the course of the semester.

Experimental investigation of muon-catalyzed t + t fusion

The muon-catalyzed fusion (μCF) process in tritium was studied by the μCF collaboration on the muon beam of the JINR Phasotron. The measurements were carried out with a liquid tritium target at the temperature 22 K and density approximately 1.25 of the liquid hydrogen density (LHD). Parameters of the μCF cycle were determined: the ttμ muonic molecule formation rate λttμ = 2.84(0.32) μs−1, the ttμ fusion reaction rate λf = 15.6(2.0) μs−1, and the probability of muon sticking to helium ωtt= 13.9(1.5)%. The results agree with those obtained earlier by other groups, but better accuracy was achieved due to our unique experimental method.

Water sorption and diffusional properties of a cured epoxy resin measured using alternating ionic liquids/aqueous electrolytes in electrochemical impedance spectroscopy

The protective quality of a coating is often measured by how long it delays the arrival of water to the substrate. The transport of water in, redistribution within, and eventually through a coating to the substrate has long been investigated through electrochemical impedance spectroscopy (EIS). EIS measurements employing alternating nonaqueous (room temperature ionic liquids, RTIL) and aqueous electrolytes elucidated the behavior of water within the coating. Diffusion coefficients could be measured and the redistribution of water into percolating paths identified. The use of RTIL alternating with aqueous electrolytes allows determination of intrinsic properties (water volume fraction at saturation and relative dielectric) and kinetic properties predicted by the Brasher Kingsbury formulation. This article focuses on the sensitivity of these intrinsic and kinetic properties to test duration in an unique experimental method.

Real-Time View of Mesoscopic Surface Diffusion

Photoemission electron microscopy is used to study the thermal decay of Ag islands grown epitaxially on Si(001) surfaces. (2 x 3) Ag reconstructed zones, due to migrating Ag atoms supplied to the surface by the decaying islands, surround each of the islands. The shape of these reconstructed zones depends on the degree of diffusion isotropy in the system. We demonstrate that the imaging of these reconstructed "isocoverage zones" constitutes a unique experimental method for directly observing diffusion fields in epitaxial systems. We describe the dynamics of the thermal decay of the islands and the isozones in the context of a continuum diffusion model.

Insight into protein dynamics from nuclear magnetic relaxation studies

Summary — In the review (63 references) the nuclear magnetic relaxation which is a unique experimental method giving insight into dynamic processes existing in proteins and covering a broad range of time scales was presented. This method, however, is demanding experimentally and theoretically. Exprimental methods limited to 15 N nuclei are briefly presented and their limitations discussed. Analysis of experimental relaxation data for proteins can be done in the frame of model-free approach or applying spectral density mapping. Both those approaches are difficult for the physical interpretation of results. Besides motional parameters, some structural parameters influence relaxation rates and have to be estimated or determined. Hopefully, many problems connected with the analysis of relaxation data in proteins can be overcome with relaxation measurements at multiple magnetic fields for different isotopes like 15 N, 13 C, and 2 H.

Investigation on the aerodynamic performance of an ejection seat

AbstractA unique experimental method is used, in combination with numerical calculation and engineering estimation, to study the aerodynamic performance of an ejection seat at M = 0·60, 0·90 and 1·20, angles-of-attack α = 0°~360°, and sideslip angles (β = 0°~–90°. Several basic characteristics of the aerodynamic performance are explored. The normal force of the ejection seat varies in a sinusoidal way and the axial force in a cosinoidal way, with the angle-of-attack. The model is statically unstable longitudinally at most attitude angles and the longitudinal stability could be improved by a stabiliser. These characteristics result from a large low pressure area caused by the leeward separation and the windward high pressure area in the ejection seat flow field, at all α, due to the blunt configuration. A set of engineering calculation formulae is deduced, based on the aerodynamic characteristics of the ejection seat.

Do reports of consciousness during cardiac arrest hold the key to discovering the nature of consciousness?

Perhaps the biggest challenge facing neuroscience at the dawn of the 21st century is understanding the relationship between mind, consciousness and the brain. Editorials in recent years have highlighted the difficulties faced by cognitive neuroscience in attempting to answer questions regarding the nature, as well as the mechanism by which subjective experiences and our sense of consciousness may arise through neuronal processes. Current scientific views regarding the origin of consciousness vary widely and range from an 'epiphenomenon' arising from neuronal networks, to neuronal quantum processes, to a separate undiscovered scientific entity. Although there has been a lack of experimental studies to test these theories, recent studies have indicated that the study of the human mind during cardiac arrest may hold the key to solving the mystery of consciousness. Four published prospective studies of cardiac arrest survivors have demonstrated that paradoxically human mind and consciousness may continue to function during cardiac arrest. This is despite the well demonstrated finding that cerebral functioning as measured by electrical activity of the brain ceases during cardiac arrest, thus raising the possibility that human mind and consciousness may continue to function in the absence of brain function. In this article the broad theories for the causation of consciousness are reviewed as well as a novel method to study consciousness during cardiac arrest. This may provide a unique experimental method to determine the nature of human mind and consciousness as well as its relationship with the brain.