New Method For Measurement Research Articles

New Method of Measurement of Coefficient of Thermal Conductivity

Several conventional steady-state measuring methods of material coefficient of thermal conductivity was systemically compared and discussed. The limitations and shortcomings of the infinite flat layer method, the infinitely long cylinder method and the concentric spherical shell layer method were pointed out. A new method for measuring the material coefficient of thermal conductivity, standard sample method, was proposed. The measure principle, the preparation of standard sample, the measure process and the obtainment of the result were presented. The advantages and applicability of the standard sample method to measure coefficient of thermal conductivity were evaluated.

SU‐E‐I‐40: New Method for Measurement of Task‐Specific, High‐Resolution Detector System Performance

Purpose:Although generalized linear system analytic metrics such as GMTF and GDQE can evaluate performance of the whole imaging system including detector, scatter and focal‐spot, a simplified task‐specific measured metric may help to better compare detector systems.Methods:Low quantum‐noise images of a neuro‐vascular stent with a modified ANSI head phantom were obtained from the average of many exposures taken with the high‐resolution Micro‐Angiographic Fluoroscope (MAF) and with a Flat Panel Detector (FPD). The square of the Fourier Transform of each averaged image, equivalent to the measured product of the system GMTF and the object function in spatial‐frequency space, was then divided by the normalized noise power spectra (NNPS) for each respective system to obtain a task‐specific generalized signal‐to‐noise ratio. A generalized measured relative object detectability (GM‐ROD) was obtained by taking the ratio of the integral of the resulting expressions for each detector system to give an overall metric that enables a realistic systems comparison for the given detection task.Results:The GM‐ROD provides comparison of relative performance of detector systems from actual measurements of the object function as imaged by those detector systems. This metric includes noise correlations and spatial frequencies relevant to the specific object. Additionally, the integration bounds for the GM‐ROD can be selected to emphasis the higher frequency band of each detector if high‐resolution image details are to be evaluated. Examples of this new metric are discussed with a comparison of the MAF to the FPD for neuro‐vascular interventional imaging.Conclusion:The GM‐ROD is a new direct‐measured task‐specific metric that can provide clinically relevant comparison of the relative performance of imaging systems.Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation

Development of a New Method for Measurement of Neutron Detector Efficiency up to 20 MeV

A new approach to neutron detector efficiency detemination has been taken. A neutron detector has been calibrated with a 252Cf source at low energy. The calibration can be extended to energies above 8 MeV with accelerator-based neutron sources. This techniques uses the fact that the cross section for a symmetric reaction with nucleus of atomic number A yielding a final nucleus with atomic number (2A−1) and a neutron A+A→(2A−1)+n. This reaction must be symmetric about 90∘ in the center-of-mass system. The laboratory energies for the neutrons at the paired energies differ substantially. Thus, an efficiency known at one of the two angles can be used to determine the efficiency to higher energies or, for a negative Q, to lower neutron energies.

Issues and pitfalls in method comparison studies

Method comparison studies are needed for validation of new methods of measurements, for example, non-invasive blood pressure measurements against standard reference methods. After a brief introduction into method comparison studies, this paper is organized in three sections. The first section deals with the widely, though not always appropriately, used classical Bland-Altman plot with the limits of agreement and its extensions with non-constant bias and multiple observations. The second section comments on other statistical approaches including correlation coefficients, linear regressions and sensitivities and specificities which are sometimes seen in method comparison studies. The third section proposes the usage of linear mixed effects models as a flexible way to deal with questions associated with method comparison studies.

A new method for measurement of ACE2 activity in tissues using fluorescent angiotensin peptides (779.9)

The carboxypeptidase ACE2 is a key enzyme of the renin‐angiotensin system, being primarily responsible for the formation of Ang ‐(1‐7 ) by cleavage of the carboxy‐terminal end of Ang II as well as the degradation of Angiotensin A to alamandine. The aim of this study was to develop a new method for measurement of ACE2 activity using the fluorecent Ang A and Ang II and HPLC. To evaluate the activity of ACE2, we used samples of heart, kidney and lung of FVBN wild type mice. Samples were homogenized in buffer for optimal activity of ACE2. Initially, we optimized the conditions of the assay using different concentrations of recombinant human enzyme rhACE2 at different incubation times with the substrate Ang II or Ang A. After the assay optimization, our results showed a linear formation of Ang‐(1‐7) or Alamandine linear with the concentration of RhACE2 and time of incubation. The homogenates of the tissues and the cocktail of inhibitors used for the incubation did not produce fluorescence. With the addition of the protease inhibitors Z ‐prolyl‐ prolinal , Captopril Chymostatin, Phosphoramidon , DL Thiorphan , Amastatin , Bestatin , Benzilsuccinaeo and PCMB, it was possible to inhibit the enzymes related to the SRA except ACE2 ,ensuring the reproducibility of the assay. Losartan also used to prevent the binding of the substrates to AT1 receptors present in homogenates. The ACE2 inhibitor MLN4760,abolished the formation of Ang‐(1‐7) or Alamandine by the homogenates. However, as described previously, DX600 was not able to inhibit ACE2 in mice tissue homogenate. The sensitivity of the assay was higher with the use of Ang A as substrate. This novel non‐isotopic, HPLC‐based method can be used for studies on the functional role of ACE2 in physiological and pathological conditions.Grant Funding Source: INCT‐CNPq, CAPES, FAPEMIG

Bone-seeking superparamagnetic iron oxide nanoparticles (SPIONs) for magnetic resonance imaging of bone turnover in early osteoarthritis

Bone-seeking superparamagnetic iron oxide nanoparticles (SPIONs) for magnetic resonance imaging of bone turnover in early osteoarthritis

Characterization of early cartilage degeneration associated with anterior cruciate ligament injury using T1-rho mapping magnetic resonance imaging

Characterization of early cartilage degeneration associated with anterior cruciate ligament injury using T1-rho mapping magnetic resonance imaging

Stochastic Measurement of Power Grid Frequency Using a Two-Bit A/D Converter

This paper presents a new method for measurement of power grid frequency based on the use of three complementary strategies: stochastic A/D conversion, finite impulse response filtering and signal frequency estimation using zero-crossing detection. Although such an amalgamated concept offered great flexibility in choice of system parameters, this paper presents the variant with the two-bit A/D converter, which requires the simplest hardware. It is shown that this solution is highly robust against signal distortions, even when harmonic distortion factors have a value of 100%.

How Cells Feel: Stochastic Model for a Molecular Mechanosensor

Understanding mechanosensitivity (i.e., how cells sense the stiffness of their environment) is very important, yet there is a fundamental difficulty in understanding its mechanism: to measure an elastic modulus one requires two points of application of force—a measuring and a reference point. The cell in contact with substrate has only one (adhesion) point to work with, and thus a new method of measurement needs to be invented. The aim of this theoretical work is to develop a self-consistent physical model for mechanosensitivity, a process by which a cell detects the mechanical stiffness of its environment (e.g., a substrate it is attached to via adhesion points) and generates an appropriate chemical signaling to remodel itself in response to this environment. The model uses the molecular mechanosensing complex of latent TGF-β attached to the adhesion point as the biomarker. We show that the underlying Brownian motion in the substrate is the reference element in the measuring process. The model produces a closed expression for the rate of release of active TGF-β, which depends on the substrate stiffness and the pulling force coming from the cell in a subtle and nontrivial way. It is consistent with basic experimental data showing an increase in signal for stiffer substrates and higher pulling forces. In addition, we find that for each cell there is a range of stiffness where a homeostatic configuration of the cell can be achieved, outside of which the cell either relaxes its cytoskeletal forces and detaches from the very weak substrate, or generates an increasingly strong pulling force through stress fibers with a positive feedback loop on very stiff substrates. In this way, the theory offers the underlying mechanism for the myofibroblast conversion in wound healing and smooth muscle cell dysfunction in cardiac disease.

A New Method for Measurement of Low-Frequency Noise of MOSFET

In this paper, we present a new method for measuring the low-frequency noise of MOSFET transistors. A closed-loop structure is used in order to bias the MOSFET under test. This method eliminates the need for I-V characteristics of the MOSFET device, transconductance measurement, current source, and current amplifier which are required in a conventional gate-referred low-frequency noise measurement. The proposed method simplifies the low-frequency noise measurement and reduces the cost of the measurement test setup significantly. The proposed method directly measures the gate-referred noise of MOSFET in contrast to the conventional method which measures drain current noise of MOSFET and divides it by MOSFET transconductance. Therefore, the need for accurate measurement of I-V characteristics of the MOSFET is eliminated, leading to the better accuracy of the measured noise. Circuit implementation of the test setup is presented in this paper. Results of this measurement method are compared to those of the conventional measurement method. It has been shown that the results using two methods are comparable.

Nonlinear propagation effects on measurement of backscatter coefficient of tissue-mimicking materials

Measurement of the ultrasonic backscatter coefficient (BSC) holds great promise in providing quantitative diagnostic information on various diseases. Many clinical studies utilize the reference phantom method. In this method, the measured BSC is the ratio of the power spectrum of the scattered sound from the patient to the power spectrum from the reference phantom multiplied by the known BSC of the reference and an attenuation correction factor. In these studies, nonlinear propagation has been ignored. Nonlinear propagation causes changes in the power spectrum as incident energy is converted to harmonics and the acoustic signal undergoes nonlinear attenuation. This study characterized the effects of nonlinear propagation on reference phantom measurements of BSC from four tissue-mimicking samples in the frequency range from 2 to 20 MHz and incident pressure from 1 to 10 MPa (measured in water) using single element focused transducers. Samples consisted of glass microspheres suspended in a mixture of agar and concentrated milk. The resulting BSC varied by up to a factor of 30 depending on the incident pressure. Substantial changes in the overall shape of the BSC vs frequency were also observed. New methods of measurement of BSC that account for nonlinear propagation are explored.

Current Trends in Webometrics Research

Webometrics is the quantitative analysis of Web phenomena. The growth of Web technologies has opened new avenues for Web researchers for measurement and analyses of the phenomenon. Webometrics is traditionally used for quantifying Web data related to footprints of researchers or institutions on the Web measured in terms of their research publications and other parameters. The paper looks at the recent developments in webometrics research in light of emergence of social Web and big data, and their applications in new research fronts and future perspective of webometrics research. The paper also discusses about the recent developments in research techniques in webometrics such as query splitting and virtual memetics in the social network sites. It is observed that the growth of Web technologies has possibly posed new challenges for traditional citation databases which have been extensively used so far for measuring research impact of universities, institutions or individual researchers. The new trend has shown that impact measures are in the verge of acceptance as new method for measurement of academic and research contributions. One notable example for this is altmetrics. In the nutshell the paper gives an overview of the emerging trends and impact measuring techniques used in webometrics research.

A new method for measurement of placental elasticity: Acoustic radiation force impulse imaging

IntroductionThe velocities of the lateral shear waves (Vs; m s−1) generated by an acoustic radiation force impulse (ARFI) correlate with Young's modulus. Therefore, ARFI can be used as a new method to evaluate tissue elasticity. The aim of this study was to investigate the safety of ARFI imaging and the differences in placental elasticity in complicated cases. MethodsThe study population included 115 patients between 26 and 41 weeks gestation, who were divided into three groups, namely normal, fetal growth restriction (FGR) and pregnancy-induced hypertension (PIH). After delivery, the Vs values of the placenta were measured ex vivo. After ARFI imaging, microscopic examination was performed, the Vs values were compared among the three groups and the relationship between the Vs values and neonatal birthweight Z-score was investigated. ResultsNo histological changes were noted even after ARFI imaging. The Vs values in the FGR group were significantly higher than those in the normal group (1.94 ± 0.74 and 1.31 ± 0.35 m s−1, respectively; p < 0.05). The Vs values demonstrated a significant negative correlation with the Z-score. Moreover, as the Z-score became lower, the Vs values became higher in the range of Z-scores under −0.5 standard deviation (SD). DiscussionWe speculate that the increased Vs values in the FGR group may have been caused by histological changes, and that a more severe FGR might result in increased Vs values. ConclusionARFI imaging was observed to have no apparent histological damage to the placental tissue. Ex vivo placentas from the FGR group were significantly more firm. Moreover, Vs values and Z-scores of birthweight had a significant negative correlation. Additional investigations are needed about the utility of this method for the evaluation of placental function in vivo.

Research on Cable Force Testing Method of Cable-Stayed Bridge Model Test

A new method of measurement of the cable force in cable-stayed bridge model test is introduced. Pressure ring sensor is used as the main component in this method and the tension of the stay cables can be measured real-time and in time. It is vertified that this method is exact and credible by model test and can be used in actual cable-stayed bridge. The static measurements for the test model are conducted. The testing results are compared with the numerical results of finite element model developed for the test model. A platform is established for the future researchs.

A New Method for Measurement of the Vitrification Rate of Earthenware Texture by Scanning Electron Microscope

A new method for determining the vitrification rate of pottery depending on the firing temperature was devised using secondary electron images (SEI) of scanning electron microscope (SEM). Several tests were performed to establish the appropriate operating conditions of SEM and reproducibility as well as to examine the applicability of the method. The grayscale values converted from each pixel of SEI were used to determine the vitrification rate of pottery, which in our study were artificially fired specimens composed of three types of clay. A comparison between the vitrification rate value and appearance temperature of minerals shows that mullite formation starts at 1,100°C, during which the vitrification rate rapidly increases by over 10%. In consequence, the result presented here demonstrates that the new method can be applied to estimate the firing temperature of pottery.

Analysis of a new method of measurement and visualization of indoor conditions by infrared thermography

We present a new tool of measurement and visualization of the indoor ambient parameters (air temperature, air speed, and mean radiant temperature) by infrared thermography. The theoretical fundamentals are discussed. They include a design stage, the mathematical modeling, the measurement procedure, and the performance evaluation through error analysis. The measuring system consists of a set of auxiliary devices (targets) arranged on a measurement grid. An infrared camera measures their temperature histories. From each temperature chronology, the three ambient parameters are locally deduced together by solving an inverse heat transfer problem. The results are then mapped to provide a 2D or 3D visualization. The question of identifiability is addressed leading to a robust parameter estimation algorithm. The robustness of the algorithm is tested for a wide range of noisy data during a numerical experiment. The numerical data are built by varying the air speed from 0 ms(-1) to 2 ms(-1) with a step of 0.2 ms(-1), the air temperature from 15 °C to 30 °C with a step of 3 °C and the mean radiant temperature from 15 °C to 30 °C with a step of 3 °C. It appears that stability and repeatability are guaranteed by the presented method for the range of ambient parameters and accuracy usually found and needed in indoor conditions. Brief illustrative experimental results are given as an initial validation of the method. Since the spatial distributions of these ambient parameters are obtained qualitatively and quantitatively, the method is suitable for indoor microclimate mapping, visualization of air patterns, building inspection, thermal comfort assessment, etc.

A new method for measurement of air–fuel ratio based on the response time of binary-type exhaust gas oxygen (BEGO) sensor for application in small spark ignition (SI) engines

A binary-type exhaust gas oxygen (BEGO) sensor that is usually used to maintain the air–fuel ratio (AFR) at stoichiometric conditions in current spark ignition (SI) engines is significantly lower in cost compared with the universal exhaust gas oxygen sensor. However, it can only switch from a high state (≈0.7 V) to a low state (≈0.1 V) when the mixture goes from richer to leaner than stoichiometric conditions or vice versa. Thus, it cannot indicate the actual AFR. A novel method of estimating the AFR of an SI engine using a BEGO sensor has been demonstrated in this work for leaner than stoichiometric mixtures. Experiments were conducted on a single-cylinder, manifold-injection SI engine. The air–fuel mixture was initially kept at a richer than stoichiometric level while the engine was maintained at constant speed and throttle. The mixture was suddenly changed to a leaner than stoichiometric level. The switching time of the BEGO sensor during this operation was noted. This was repeated for different initial and final AFRs. A relationship between the switching time and change in AFR was obtained for different initial AFRs. A look-up table to determine the AFR was made and used under test conditions. The error is less than 5% in the estimated AFR. The system was also incorporated on a low-cost microcontroller-based engine management system and tested under laboratory conditions.

The risks of using REDD+ to manage rich socio-ecological systems

REDD+ is an important development in environmental and social justice policy instruments. However, its success depends on a network of complex contingencies, and the achievement of difficult governance transformations in countries that are under severe economic pressure. It ought be obvious that there are significant risks associated with this endeavour, but overt risk management, using standard approaches, is not evident. This paper highlights some of the many risks that the governance of REDD+ (in common with most environmental policy innovations) needs to pay attention to in order to avoid policy failure. There are eight distinct elements that have to work for the REDD+ program to achieve its public policy goals, and each of these carries its own risk. These are: securitisation of carbon sequestration; protection for complex non-carbon values, ensuring the integrity of the supply of credit; multi-level administration and aggregation of tradeable carbon interests; managing the social and economic imbalance of interests; deploying new methods for measurement and securitisation of interests; ensuring a platform of rules, administrative and enforcement systems, teams and intelligence networks; and achieving price and ‘brand’ competitiveness in a crowded carbon offsets marketplace. Although the issues listed in this paper are not comprehensive, they highlight major concerns and support the argument that a comprehensive and systematic approach to policy risk is likely to add value to the REDD+ implementation. The paper suggests that good management practice would separate risk management from policy or instrument development, and embed this aspect of good governance with a sufficient level of authority to ensure that the negative potentials are managed with a degree of vigour consistent with the importance of the issues.

METHOD COMPARISON STUDIES IN MEDICINE

INTRODUCTION AND OBJECTIVE:Most of important variables measured in medicine are in numerical forms or continuous in nature. New instruments and tests are constantly being developed for the purpose of measuring various variables, with the aim of providing cheaper, non-invasive, more convenient and safe methods. When a new method of measurement or instrument is invented, the quality of the instrument has to be assessed. Agreement and reliability are both important parameters in determining the quality of an instrument. This article will discuss some issues related to methods comparison study in medicine for the benefit of medical professional and researcher.METHOD:This is a narrative review and this article review the most common statistical methods used to assess agreement and reliability of medical instruments that measure the same continuous outcome. The two methods discussed in detail were the Bland-Altman Limits of Agreement, and Intra-class Correlation Coefficient (ICC). This article also discussed some issues related to method comparison studies including the application of inappropriate statistical methods, multiple statistical methods, and the strengths and weaknesses of each method. The importance of appropriate statistical method in the analysis of agreement and reliability in medicine is also highlighted in this article.CONCLUSION:There is no single perfect method to assess agreement and reliability; however researchers should be aware of the inappropriate methods that they should avoid when analysing data in method comparison studies. Inappropriate analysis will lead to invalid conclusions and thus validated instrument might not be accurate or reliable. Consequently this will affect the quality of care given to a patient.

Application of a He3Ne infrared laser source for detection of geometrical dimensions of cracks and scratches on finished surfaces of metals

In this study, the authors addressed a new method of measurement for microscratches and cracks on finished metallic surfaces. The technology proposed here can be used in aviation, automobile, machine-tools, bearings, electrical and thermal devices (detection of electrical and thermal contact resistance), and many other industrial fields where finished surfaces have to be inspected for quality before use. The technology is based on the application of He3Ne laser optics. This measurement method allows for the inspection of geometrical parameters such as depth and width of scratches and cracks and consists of a low-energy He3Ne red laser beam (wavelength 633nm) with a cross-section of 0.48mm, beam expander with special designed slit, multi-axis stage with sample holder and CCD (charge-coupled device) visual detection system. Using experimental data, a mathematical algorithm was created in order to calculate the depths and widths of the scratches and cracks where the method of center of gravity (centroid) of the imaged area was used. The results showed a good correlation between the experimental and calculated values of the dimensions of the scratches. Future work will deal with the determination of the geometrical dimensions of microcracks.