Different Methods Of Measurement Research Articles

Critical assessment of methods for measurement of temperature profiles and heat load history in microwave heating processes-A review.

Limitations of microwave processing due to inhomogeneities of power input and energy absorption have been widely described. Over- and underheated product areas influence reproducibility, product quality, and possibly safety. Although a broad range of methods is available for temperature measurement and evaluation of time/temperature effects, none of them is sufficiently able to detect temperature differences and thermally induced effects within the product caused by inhomogeneous heating. The purpose of this review is to critically assess different methods of temperature measurement for their suitability for different microwave applications, namely metallic temperature sensors, thermal imaging, pyrometer measurement, fiber optic sensors, microwave radiometry, magnetic resonance imaging, liquid crystal thermography, thermal paper, and biological and chemical time-temperature indicators. These methods are evaluated according to their advantages and limitations, method characteristics, and potential interference with the electric field. Special attention is given to spatial resolution, accuracy, handling, and purpose of measurement, that is, development work or online production control. Differences of methods and examples of practical application and failure in microwave-assisted food processing are discussed with a special focus on microwave pasteurization and microwave-assisted drying. Based on this assessment, it is suggested that infrared cameras for measuring temperature distribution at the product surface and partially inside the product in combination with a chemical time/temperature indicator (e.g., Maillard reaction, generating heat-induced color variations, depending on local energy absorption) appear to be the most appropriate system for future practical application in microwave food process control, microwave system development, and product design. Reliable detection of inhomogeneous heating is a prerequisite to counteracte inhomogeneity by a targeted adjustment of process and product parameters in microwave applications.

Review of net water uptake in the management of acute ischemic stroke.

CT densitometry-based methods to directly quantify net water uptake in ischemic brain tissue have been increasingly applied recently. There is potential for net water uptake to be used as an imaging biomarker for the pathophysiology of infarcted lesions. This review is aimed at summarizing the potential and current status of the application of net water uptake as a biomarker in the management of ischemic stroke and future directions in this context. Specifically, we provide a brief overview of the principle and different methods of net water uptake measurement, followed by a discussion of the role of net water uptake in predicting malignant brain edema and hemorrhagic transformation, evaluating lesion age, and predicting the efficacy of reperfusion therapy and long-term clinical prognosis. Artificial intelligence will help address the lack of automation and standardization in the measurement of net water absorption. Further validation of net water uptake in a prospective multicenter setting is necessary. KEY POINTS: • NWU can be used as a quantitative imaging biomarker for developing malignant brain edema in anterior and posterior circulation strokes. • The difference in NWU in edema arrest or reversibility suggests that rapid and successful revascularization can influence the progression of ischemic edema. • NWU can be used to predict the age of a lesion, with predictive power comparable to that of DWI/FLAIR mismatch.

Three-dimensional reconstruction and virtual reposition of fragments compared to two dimensional measurements of midshaft clavicle fracture shortening

BackgroundMidshaft clavicle fracture shortening measurement is a reported key element for indication to surgical management and reporting of clinical trials. Determination of pre-fracture clavicle length for shortening measurement remains an unresolved issue. The purpose of the study was to assess accuracy of a novel technique of three-dimensional reconstruction and virtual reposition of bone fragments (3D-VR) for determination of pre-fracture clavicle length and measurement of shortening.MethodsAccuracy of 3D-VR measurements was assessed using 5 synthetic bone clavicle fracture models. Measurements were compared between caliper and 3D-VR technique measurements. Correlation between 3D-VR and 2D measurements on standard radiographs was assessed on a cohort of 20 midshaft fractures. Four different methods for 2D measurements were assessed.ResultsMean difference between caliper measurements and 3D-VR was 0.74 mm (95CI = − 2.51;3.98) (p = 0.56) on synthetic fracture models. Mean differences between 3D-VR and standard radiograph shortening measurement methods were 11.95 mm (95CI = 7.44;16.46) for method 1 (Jeray et al.) and 9.28 mm (95CI = 4.77;13.79) for method 2 (Smekal et al.) (p < 0.05). Differences were − 1.02 mm (95CI = − 5.53;3.48) for method 3 (Silva et al.) and − 2.04 mm (95CI = − 6.55;2.47) for method 4 (own method). Interobserver correlation ranged between 0.85 and 0.99. A false positive threshold of 20 mm was measured by the two observers in 25% of the case according to method of method 1, 30–35% with method 2, 15% with method 3 et al. and 5–10% with the method 4.Conclusion3D VR is accurate in measuring midshaft clavicle fracture length and shortening. Two dimensional measurements may be used for approximation of clavicular shortening.

Reliability of cerebral autoregulation using different measures of perfusion pressure in patients with subarachnoid hemorrhage.

Dynamic cerebral autoregulation to spontaneous fluctuations in cerebral perfusion pressure (CPP) is often assessed by transcranial Doppler (TCD) in the time domain, yielding primarily the mean flow index (Mx), or in the frequency domain using transfer function analysis (TFA), yielding gain and phase. For both domains, the measurement of blood pressure is critical. This study assessed the inter‐method reliability of dynamic cerebral autoregulation using three different methods of pressure measurement. In 39 patients with aneurysmal subarachnoid hemorrhage, non‐invasive arterial blood pressure (ABP), invasive ABP (measured in the radial artery) and CPP were recorded simultaneously with TCD. Intraclass correlation coefficient (ICC) was used to quantify reliability. Mx was higher when calculated using invasive ABP (0.39; 95% confidence interval [95% CI]: 0.33; 0.44) compared to non‐invasive ABP, and CPP. The overall ICC showed poor to good reliability (0.65; 95% CI: 0.11; 0.84; n = 69). In the low frequency domain, the comparison between invasively measured ABP and CPP showed good to excellent (normalized gain, ICC: 0.87, 95CI: 0.81; 0.91; n = 96; non‐normalized gain: 0.89, 95% CI: 0.84; 0.92; n = 96) and moderate to good reliability (phase, ICC: 0.69, 95% CI: 0.55; 0.79; n = 96), respectively. Different methods for pressure measurement in the assessment of dynamic cerebral autoregulation yield different results and cannot be used interchangeably.

Comparison of four methods to -determine cage width in tibial tuberosity advancement.

The objective of this study was to test a method for determining the width of the tibial tuberosity advancement (TTA) cage without the need for extension of the stifle joint, while producing preoperative radiographs. TTA cage size was determined by applying 4 different methods using radiograph images in mediolateral direction of fully extended stifles of dogs (n=43), with and without naturally occurring cranial cruciate ligament disease: parallel shift (PS) method, common tangent (CT) method, «2,1» method (cage size = 2,1 × tibia plateau length - tibial tuberosity width), and margo cranialis (MC) method (cage size = length of MC/6*1,75). Two new methods, «2,1», and MC were compared to the existing CT and PS methods. All 4 methods resulted in reliable cage sizes. Intraclass correlation coefficients showed an excellent reliability of the CT and PS to the «2,1» method and a good reliability in regards to the MC method. In conclusion, TTA cage size of the tibia anatomy alone can be determined on radiographs without the need of full extension of the stifle joint. Based on the results, two different methods of cage size measurement are recommended in order to increase diagnostic accuracy and to prevent the insertion of suboptimal cages.

Laboratory assessment in ABO-incompatible renal transplant

Background: In ABO-incompatible renal transplants, reliable ABO antibody titre measurements are crucial in managing humeral rejection and graft failure. There is a paucity of published studies comparing the different laboratory methods of pre-transplant ABO antibody titre measurement.

Overview Of Measurement And Evaluation Methods Of Wind Farm And System Inertia Under Large-scale Wind Power Grid Connection

With the large-scale development of new energy, large-scale wind power is incorporated into the power grid, the inertia level of the power system continues to decrease, the system regulation ability continues to weaken, and the system stability is seriously challenged. The evaluation of inertia has become a hot research issue for scholars. Firstly, this paper introduces the basic concept and components of power system inertia. Then, the different methods of inertia measurement and evaluation of wind farm and power system are reviewed. Finally, the future research directions in the field of power system inertia evaluation are summarized.

Update on the applications and limitations of alpha-fetoprotein for hepatocellular carcinoma.

Alpha-fetoprotein (AFP) is an oncofetal glycoprotein that has been used as a tumor marker for hepatocellular carcinoma (HCC) in combination with ultrasound and other imaging modalities. Its utility is limited because of both low sensitivity and specificity, and discrepancies among the different methods of measurements. Moreover, its accuracy varies according to patient characteristics and the AFP cut-off values used. Combination of AFP with novel biomarkers such as AFP-L3, Golgi specific membrane protein (GP73) and des-gamma-carboxyprothrombin significantly improved its accuracy in detecting HCC. Increased AFP level could also signify severity of hepatic destruction and subsequent regeneration and is commonly observed in patients with acute and chronic liver conditions and cirrhosis. Hereditary and other non-hepatic disorders can also cause AFP elevation.

Quality of life of diabetes patients in North India

Background: India is witnessing a dramatic rise in the prevalence of diabetes mellitus. In this study, quality of life (QOL) of patients with diabetes and its determinants were assessed. Second, the valuation of QOL using different methods of measurement was examined. Methods: A community-based survey comprising 306 adults diagnosed with diabetes was undertaken in an urban slum area of Chandigarh city. Direct methods of QOL assessment such as time trade-off (TTO) and Visual Analog Scale (VAS) along with indirect like EuroQol 5-Dimensional 5-Level Instrument (EQ-5D-5L) and the QOL Instrument for Indian Diabetes Patients (QOLID) were used. Multiple linear regression was used to compute coefficients to assess point estimate of QOL using the Indian QOLID tool. Results: Overall, health utility scores for a person with diabetes were 0.68 (with TTO method), 0.60–0.64 (with VAS) analog scale, and EQ-5D-5L method, respectively. Valuation of QOL using direct methods yielded utility values which were significantly higher than indirect methods (EQ-5D-5L). Conclusion: Overall, this study found that diabetes is responsible for physical, psychological, and social role disturbance among the patients. In addition, choice of using direct or indirect methods of utility estimation may have practical implications while calculating incremental cost-effectiveness ratios.

The role of the audit committee in accounting and finance expertise on earnings quality

This study aims at examining the effect of the audit committee with accounting and finance expertise on the earnings quality of manufacturing companies in Indonesia. The earnings quality measurement uses the absolute value of discretionary accrual. This study uses three measurements of discretionary accruals, the Jones model (Jones, 1991), the modified Jones (Dechow, Sloan, &amp; Sweeney, 1995), and the Kasznik models (Kasznik, 1999). Further, the current study refers to Badolato, Donelson, and Ege (2014) to identify the audit committee expertise. The data were collected from the Indonesia Stock Exchange (IDX) between 2015 and 2017 with 331 observations. The results showed that audit committees’ characteristics with both accounting and finance expertise have a negative effect on discretionary accrual. Thus, audit committees’ members with both accounting and finance expertise have reduced the level of discretionary accruals. The result is consistent using three measurements of discretionary accruals. Therefore, the audit committee members with both accounting and finance expertise have a positive effect on improving the quality of firms’ earnings. Our result is robust to different methods of discretionary accrual measurement. This study may be very helpful for those audit committees seeking to improve their composition and way of working. In other words, the findings of this study are potentially relevant to both audit committees and policy-makers

Evolution of Middle Ear Modelling Techniques: A Review.

This review article attempts to analyze the various research studies conducted in developing the models to evaluate the anatomy of the middle ear, its biomechanics, and the applications of these models in normal and diseased states.Various studies conducted over the past 50-60 years have been critically analyzed. We also discuss the various advantages and disadvantages of different methods of measurement of middle ear parameters. Beginning from anatomical modelling to histopathological sections and the latest three-dimensional (3D) reconstruction with finite element modelling, various methods of middle ear measurements have been critically analyzed.At the end of this review, we have concluded that the best and most effective method of middle ear modelling is the 3D reconstruction using high-resolution computed tomography and finite element modelling.

Evaluation of intraventricular flow by multimodality imaging: a review and meta-analysis

BackgroundThe aim of this systematic review was to evaluate current inter-modality agreement of noninvasive clinical intraventricular flow (IVF) assessment with 3 emerging imaging modalities: echocardiographic particle image velocimetry (EPIV), vector flow mapping (VFM), and 4-dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR).MethodsWe performed a systematic literature review in the databases EMBASE, Medline OVID and Cochrane Central for identification of studies evaluating left ventricular (LV) flow patterns using one of these flow visualization modalities. Of the 2224 initially retrieved records, 10 EPIV, 23 VFM, and 25 4D flow CMR studies were included in the final analysis.ResultsVortex parameters were more extensively studied with EPIV, while LV energetics and LV transport mechanics were mainly studied with 4D flow CMR, and LV energy loss and vortex circulation were implemented by VFM studies. Pooled normative values are provided for these parameters. The meta- analysis for the values of two vortex morphology parameters, vortex length and vortex depth, failed to reveal a significant change between heart failure patients and healthy controls.ConclusionAgreement between the different modalities studying intraventricular flow is low and different methods of measurement and reporting were used among studies. A multimodality framework with a standardized set of flow parameters is necessary for implementation of noninvasive flow visualization in daily clinical practice. The full potential of noninvasive flow visualization in addition to diagnostics could also include guiding medical or interventional treatment.

Оцінка вимірювання pH водного розчину та електролітними методами в окультурених ґрунтах Непалу

Soil pH is most routinely measured parameter among all others in soil chemistry laboratory. There are various methods developed for pH measurement, although we using only distilled water from the beginning. In Nepal, there do not have database for showing performance of the methods. The three methods namely; H2O, KCl and CaCl2 with their soil:solution ratios (1:1, 1:2 and 1:2.5) were used. The total 115 samples were collected randomly at a depth of 0-20 cm from the hill and terai regions of Nepal. The collected samples were analyzed following mentioned methods, separately. The various statistical tests (F-test, mean separation, correlation, and regression model) were performed for comparison. Moreover, model validation parameters were also calculated for relating H2O with electrolyte method. The three models linear, quadratic and cubic were used for this task. The result revealed the effect of methods on pH measurement was significantly different in the entire ratio. The pHH2O was 0.57, 0.56 and 0.67 units higher than pHCaCl2 in 1:1, 1:2 and 1:2.5 ratios, respectively. Whereas, 1.24, 0.99 and 0.95 units higher than pHKCl in respective ratio. Moreover, regarding timing to reach stable during measurement were in the order pHH2O (89.44 sec) &gt; pHCaCl2 (54.29 sec) &gt; pHKCl (33.08 sec). Similarly, relating modeling quadratic and cubic model showed nearly equal performance (lower RMSE, MAE and higher R2 and d) for predicting pHCaCl2 and pHKCl from the pHH2O in each soil solution ratio. The determined database can be useful for comparing used three different methods of soil pH measurement under Nepalese context.

Mechanisms of Neutralizing Anti-drug Antibody Formation and Clinical Relevance on Therapeutic Efficacy of Enzyme Replacement Therapies in Fabry Disease.

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by mutations in the α-galactosidase A (AGAL/GLA) gene. The lysosomal accumulation of the substrates globotriaosylceramide (Gb3) and globotriaosylsphingosine (lyso-Gb3) results in progressive renal failure, cardiomyopathy associated with cardiac arrhythmia, and recurrent strokes, significantly limiting life expectancy in affected patients. Current treatment options for FD include recombinant enzyme-replacement therapies (ERTs) with intravenous agalsidase-α (0.2 mg/kg body weight) or agalsidase-β (1 mg/kg body weight) every 2 weeks, facilitating cellular Gb3 clearance and an overall improvement of disease burden. However, ERT can lead to infusion-associated reactions, as well as the formation of neutralizing anti-drug antibodies (ADAs) in ERT-treated males, leading to an attenuation of therapy efficacy and thus disease progression. In this narrative review, we provide a brief overview of the clinical picture of FD and diagnostic confirmation. The focus is on the biochemical and clinical significance of neutralizing ADAs as a humoral response to ERT. In addition, we provide an overview of different methods for ADA measurement and characterization, as well as potential therapeutic approaches to prevent or eliminate ADAs in affected patients, which is representative for other ERT-treated lysosomal storage diseases.

Influence of variability in hygrothermal properties on analytical results of simultaneous heat and moisture transfer in porous materials

Depending on the data source used, the material hygrothermal properties that are used in the numerical analysis of simultaneous heat and moisture transfer will not be consistent. Differences in measurement methods and the individuality of specimens account for this. It is necessary to choose values from these different physical property sets to conduct a numerical calculation, which can cause the calculated results to differ. The subsequent range of variation in the calculated results should be quantitatively evaluated. In this study, the physical properties of several types of porous building materials were first gathered from four databases. The data were then categorized based on the kind of material and compared in terms of each physical property (density, porosity, specific heat, moisture capacity, thermal conductivity, and vapor permeability). The density, porosity, and specific heat varied by 10% on average, and the moisture capacity, thermal conductivity, and vapor permeability varied by 20% or more for all types of materials. In particular, the vapor permeability of plywood and moisture capacity of gypsum board differed by 50%. The influence that these physical property value variations had on hygrothermal calculation results was then quantitatively demonstrated for moisture and heat flow rate under a step change in the relative humidity or temperature of indoor air for a single layer wall. The moisture and heat flow rate into a single layer wall fluctuated by approximately 10%–40% due to differences in the vapor permeability and moisture capacity of the materials. For all types of materials, moisture was transferred more slowly than heat. Therefore, differences in moisture property values, such as vapor permeability and moisture capacity, influenced the results more significantly. Moreover, the moisture flow was accompanied by a phase change. The differences in moisture property values thus affected the heat flow.

Temperature Difference Measurement of Metal Surfaces at Normal Temperatures Under Sunlight by Differential Chromatic Features of Visible Images

The temperature of metal surfaces at normal temperatures under sunlight can be measured by combining visible images with machine learning (ML). But this method is susceptible to illumination conditions, which causes large errors. To solve this problem, a method of temperature difference measurement based on visible images’ differential chromatic features (DCFs) between two metal surfaces, which are at different temperatures but the same illumination, is proposed in this paper. Through experiments, temperature difference image libraries of brass surfaces under varying illumination are established. DCFs of each image are extracted, and temperature difference between two surfaces is used as the label. Models that can predict the temperature difference between two surfaces are trained by ML. Prediction results show that the mean absolute error of this temperature difference measurement method can be as low as 1.6, decreasing by 42% at most compared with those of simply measuring the surface temperature. The effect of temperature and illumination on visible images’ gray levels is analyzed. And it is concluded that the introduction of a temperature-constant surface provides a reference item for illumination, which helps to weaken the influence of illumination changes and filter out the interference caused by them. This is why the prediction accuracy can be improved by the temperature difference measurement method.

Measurement of capillary refill time with a handheld prototype device: a comparative validation study in healthy volunteers.

Validity and reproducibility of clinical capillary refill time (CRT) measurement depend on many factors in daily routine practice. We conducted a prospective validation study of an automatized handheld prototype device providing standardized CRT assessment (DiCART™) in 20 healthy volunteers. Three different methods of CRT measurement were compared before and during dynamic circulatory changes induced by venous and arterial occlusion tests at both upper and lower limb levels: CRTCLIN corresponding to basic clinical assessment and considered as the reference method; CRTVIDEO corresponding to off-line videos reviewed by investigators recorded by DiCART™; and CRTDiCART corresponding to on-line videos analysed by a built-in proprietary mathematical algorithm included in DiCART™. Five subjects were excluded because of a DiCART™ dysfunction. ROCAUC to detect arterial occlusion test changes at the upper limb level were 1.00 (95%CI 1.00; 1.00), 0.96 (95%CI 0.88; 1.00), and 0.92 (95%CI 0.79; 1.00) for CRTCLIN, CRTVIDEO, and CRTDiCART, respectively. Precision of CRTCLIN and CRTVIDEO were significantly better than CRTDiCART (0.18 and 0.20 vs. 0.28; P < 0.05). Percentages of error were 76% and 87% for CRTVIDEO and CRTDiCART, respectively. DiCART™ had an excellent discrimination to detect major changes in CRT induced by arterial ischemia. However, the perfectible precision, the poor agreement with clinical assessment and numerous device dysfunctions give leads to the development of a further version of the prototype before promoting its use in clinical practice.Trial registration clinicaltrial.gov. Identifier: NCT04538612.

Two senses of human limb position: methods of measurement and roles in proprioception

The sense of position of the body and its limbs is a proprioceptive sense. Proprioceptors are concerned with monitoring the body's own actions. Position sense is important because it is believed to contribute to our self-awareness. This review discusses recent developments in the debate about the sources of peripheral afferent signals contributing to position sense and describes different methods of measurement of position sense under conditions where vision does not participate. These include pointing to or verbal reporting of the perceived position of a hidden body part, alignment of one body part with the perceived position of another, or using memory-based repositioning tasks. The evidence suggests that there are at least two different mechanisms involved in the generation of position sense, mechanisms using different central processing pathways. The principal sensory receptor responsible for position sense is believed to be the muscle spindle. One criterion for identifying mechanism is whether position sense can be manipulated by controlled changes in spindle discharge rates. Position sense measured in two-limb matching is altered in a predictable way by such changes, while values for pointing and verbal reporting remain unresponsive. It is proposed that in two-limb matching the sensation generated is limb position in postural space. In pointing or verbal reporting, information is provided about limb position in extrapersonal space. Here vision is believed to play a role. The evidence suggests that we are aware, at the same time, of sensations of limb position in postural space as well as in extrapersonal space.

High-Resolution Multi-Channel Frequency Standard Comparator Using Digital Frequency Measurement.

The rapid improvement accuracy of the atomic frequency standard puts forward higher requirements for the measurement resolution of the atomic frequency standard comparison system. To overcome the defect that the single zero-crossing point detection is sensitive to noise in the traditional dual mixer time difference measurement method, a digital frequency measurement method is proposed. This method combines sinusoidal beat technology, multi-channel synchronous acquisition technology, and digital frequency measurement technology, and uses differential compensation of system error to realize the precision measurement of atomic frequency standard. The frequency measurement accuracy is less than 2.5 × 10−14 and the noise floor is better than 6.5 × 10−15/τ = 1 s. The system has a high frequency measurement accuracy and a low noise floor, which can realize the precise measurement of a highly stable frequency source.

From Frequency Domain to Time Transient Methods for Halide Perovskite Solar Cells: The Connections of IMPS, IMVS, TPC, and TPV.

The correlation of different methods of measurement can become an important tool to identify the dominant physical elements that govern the electronic and ionic dynamics in perovskite solar cells. The diverse phenomena underlying the response of halide perovskite materials to different stimuli are reflected in time-domain measurements, where transients appear with time scales spanning orders of magnitude, from nanoseconds to hours. We discuss the connection between different frequency- and time-domain methods to probe the voltage and current response of halide perovskite solar cells to different small perturbations. To solve the frequency-to-time transformation, we start from models of the transfer function of intensity-modulated photocurrent spectroscopy (IMPS) and derive the associated impulse response function, the transient photocurrent (TPC), in response to a short light pulse. Similarly, we determine the transient photovoltage (TPV) starting from the intensity-modulated photovoltage spectroscopy (IMVS) transfer function. We also discuss the open-circuit voltage decays (OCVD). We first show the response of simple equivalent circuit models, and then we treat the full model for generation–diffusion–recombination of electrons that shows a spiraling loop in IMPS. This model gives rise to overshoots in the time domain.