New Method For Measurement Research Articles

New device for assessment of endothelial function: plethysmographic flow-mediated vasodilation (pFMD)

Measurement of flow-mediated vasodilation (FMD) in the brachial artery by using ultrasound is a well-established technique for evaluating endothelial function. To make the measurement quicker and simpler than the measurements of conventional ultrasound FMD (uFMD), we have developed a new noninvasive method, plethysmographic FMD (pFMD), to assess vascular response to reactive hyperemia in the brachial artery. The aim of this study was to determine the accuracy of measurement of pFMD in comparison to that of measurement of conventional uFMD. This study was a multi-center, cross-sectional study. We compared pFMD by a new device using cuff pressure and volume with conventional uFMD using ultrasound in 50 men (mean age, 41 ± 9 years). pFMD significantly correlated with conventional uFMD (β = 0.59, P < 0.001). In Bland–Altman plot analysis of pFMD and conventional uFMD, the mean difference of pFMD and conventional uFMD was 0.78%, and limits of agreement (mean difference ±2 standard deviations of the difference) ranged from −4.53% to 6.11%. We demonstrated validity of the new method for measurement of pFMD, which can automate the evaluation of endothelial function in a short time. Measurement of pFMD is simpler than measurement of conventional uFMD and may have reduced artificial bias compared to that of conventional uFMD measurement (URL for Clinical Trial: https://ethics.hiroshima-u.ac.jp/site/wp-content/uploads/2022/12/eki_giji20221213.pdf. Registration Number for Clinical Trial: E2022-0131).

A new method for solids residence time distribution measurement in continuous fluidized beds

Accurate measurement of solids residence time distribution (RTD) is an important and challenging issue in developing fluidized bed reactors with continuous solids feeding and discharging. In this study, we proposed a new method for measuring solids residence time distribution, where coked bulk material was used for solids tracer and high-precision element analyzers were used to determine solids tracer fraction. A calibration procedure was established to achieve high-accuracy measurement of solids tracer fraction. The following validation tests had successfully proved the pseudo-CSTR solids flow pattern under different operating conditions and the staging effect of an inserted horizontal baffle in a small laboratory-scale fluidized bed cold model, which demonstrate the feasibility and advantages of this new solids RTD measurement method.

Разработка нового метода измерения напряженности электрического поля на основе сдвоенного электроиндукционного датчика

A new method for measuring electric field strength is proposed. The method is based on the mean value measurement method, which uses a dual electroinduction spherical sensor. The use of the dual sensor for the method implementation allows to extend the functionality of the method by mean value. The method of measurement by the mean value assumes simultaneous measurement of two values of intensity E1 and E2 in one point of electric field with opposite sign errors. As the theory of construction of the new method has shown, it is possible to determine not only the measurement result as an average of two values of the strengths, but also to estimate the error of the measurement result and tentatively determine the distance to the field source. In order to determine the distance to the field source, a coefficient of the ratio of the two found strengths at each point of the field is introduced, by which the empirical dependence of the relative distance to the field source is found. The relative distance is the ratio between the radius of the spherical sensor and the distance to the field source. By determining the relative distance at each measuring point according to this relationship and substituting it into the known expression for the error, the error of the result at the measuring point is determined. The relative distance is also used to determine the distance to the field source. Thus, the new method of measurement allows to increase the accuracy of measurement of electric field strength, determined by the relative distance to the source of the field.

Development and testing of novel functionalized polymeric thin-films for equilibrium passive sampling of PFAS compounds in water

The demand for an accurate assessment of exposure and risk from the presence of per- and polyfluoroalkyl substances (PFAS) in the aquatic environment has created the need for new methods of measurements in water at sub-parts per trillion concentrations. We explored the concept of equilibrium passive sampling for PFAS using the strategy developed for other organic compounds. Equilibrium passive sampling should predict the concentration of the chemically labile fraction of PFAS in water based on equilibrium partitioning into the sampler, without the need for site-specific calibration. Our goals were to identify sampler materials with the potential to mimic PFAS partitioning into animals and sediments and provide reversible sorption in a time frame appropriate for in situ samplers. To achieve this goal, we tested a range of candidate materials, including three broad classes of polymers embedded with suitable sorbents for PFAS. The most promising synthesized thin films were activated carbon (AC) embedded in agarose, silica-bonded human serum albumin (s-HSA) embedded in Agarose, WAX embedded in cellulose acetate, and HLB embedded in PDMS, which yielded log sampler–water partition coefficients close to 3 for many PFAS compounds. Sampler equilibration time in water was approximately one week. Investigation of the isotherms suggested that the sorption can be described across the concentration range of interest, from the ng/L range commonly found in natural uncontaminated waters to the ug/L concentrations found in contaminated sites. Also, the selected films exhibited relatively rapid desorption of PFAS, indicating that the sorbents are capable of reversible, equilibrium measurements. The present study demonstrates a potential new approach to passive sampling of PFAS.

A new method for measurement of impulsive peak level attenuation of hearing protectors

ASA/ANSI S12.42-2010 contains the first standardized test method for measuring the performance of hearing protection devices (HPDs) with high-level impulsive noise. This standard defines the impulsive peak insertion loss (IPIL) as a time-domain metric that quantifies the reduction in peak sound pressure level provided by an HPD for impulsive noises. However, IPIL as defined in S12.42-2010 is dependent on the spectrum of the impulsive noise source used for measurements of HPDs. Recent studies of HPDs with impulsive noise have led to the investigation of frequency-domain metrics and calculation methods. Using frequency-domain calculations allows the impulsive peak level attenuation to be computed for a wide range of impulsive noises, not only those used for the measurement. Consequently, significant revisions to S12.42 are under consideration and a new standard, ISO 4869-7, is being developed in parallel with the ANSI revision. This presentation highlights key proposals and substantive changes including: measurement and calculation of the frequency-dependent impulsive insertion loss (IIL), incorporation of frequency-domain aspects such as real-ear attenuation at threshold (REAT) limits to attenuation, and a new impulsive peak level attenuation metric (IPLA) to be calculated from the REAT-bounded IIL.

Numerical analysis of bending property of bi-modulus materials and a new method for measurement of tensile elastic modulus

Numerical analysis of bending property of bi-modulus materials and a new method for measurement of tensile elastic modulus

Electrochemical-Shock Synthesis of Nanoparticles from Sub-femtoliter Nanodroplets

ConspectusNanoparticles have witnessed immense development in the past several decades due to their intriguing physicochemical properties. The modern chemist is interested not only in methods of synthesizing nanoparticles with tunable properties but also in the chemistry that nanoparticles can drive. While several methods exist to synthesize nanoparticles, it is often advantageous to put nanoparticles on a variety of conductive substrates for multiple applications (such as energy storage and conversion). Despite enjoying over 200 years of development, electrodeposition of nanoparticles suffers from a lack of control over nanoparticle size and morphology. There have been heroic efforts to address these issues over time. With an understanding that structure-function studies are imperative to understand the chemistry of nanoparticles, new methods are necessary to electrodeposit a variety of nanoparticles with control over macromorphology and also microstructure.This Account details our group's efforts in overcoming challenges of classical nanoparticle electrodeposition by electrodepositing nanoparticles from water nanodroplets. When a nanodroplet full of metal salt precursor is incident on the electrode biased sufficiently negative to drive electroplating, nanoparticles form at a fast rate (on the order of microseconds to milliseconds). We start with the general nuts-and-bolts of the experiment (nanodroplet formation and methods for electrodeposition). The deposition of new nanomaterials often requires one to develop new methods of measurement, and we detail new measurement tools for quantifying nanoparticle porosity and nanopore tortuosity within single nanoparticles. We achieve nanopore characterization by using Focused Ion Beam milling and Scanning Electron Microscopy. Owing to the small size of the nanodroplets and fast mass transfer (the contents of a femtoliter droplet can be electrolyzed in only a few milliseconds), the use of nanodroplets also allows the electrodeposition of high entropy alloy nanoparticles at room temperature.We detail how a deep understanding of ion transfer mechanisms can be used to expand the library of possible metals that can be deposited. Furthermore, simple ion changes in the dispersed droplet phase can decrease the cost per experiment by orders of magnitude. Finally, electrodeposition in aqueous nanodroplets can also be combined with stochastic electrochemistry for a variety of interesting studies. We detail the quantification of the growth kinetics of single nanoparticles in single aqueous nanodroplets. Nanodroplets can also be used as tiny reactors to trap only a few molecules of a metal salt precursor. Upon reduction to the zerovalent metal, electrocatalysis at very small metal clusters can be probed and evaluated with time using steady-state electrochemical measurements. Overall, this burgeoning synthetic tool is providing unexpected avenues of tunability of metal nanoparticles on conductive substrates.

Determining peanut moisture content by scattering coefficient

Moisture content is a fundamental parameter in peanut production and storage. Moisture content information is essential for crop analysis. Crop analysis is significant for production planning and improving yield. Thus, developing a moisture content measurement system with high precision and low cost can benefit peanut production, processing, and storage. To achieve accurate and rapid nondestructive testing of shelled peanuts and peanut pods, this study proposes a new method for measuring moisture content based on the microwave scattering coefficient. The microwave free-space method was used to measure the scattering parameters of peanut samples with different moisture contents (8.11–45.59% wet basis) at different temperatures and sample thicknesses. Moreover, a peanut moisture measurement model using S-parameters was developed. Using the amplitude, phase, and real part and imaginary part combinations of the S11 and S21 parameters of the peanut samples as the input and peanut moisture content as the output, moisture content and S-parameter prediction models based on the gradient boost regression trees (GBRT), extreme gradient boost (XGBoost), and fully connected deep neural network (FC-DNN) were established. Test results verified that the FC-DNN-based model had the best prediction performance, with a coefficient of determination (R2) = 0.9998, mean absolute error (MAE) = 0.0891, mean square error (MSE) = 0.0254, and root mean square error (RMSE) = 0.1593. This study provides a new method for the nondestructive measurement of moisture content during peanut production and storage. Moreover, the proposed model can be applied for moisture content measurement of other agricultural products in the food processing industry.

A new method for measurement and calculation of unit width suspended sediment transport rate

Abstract The unit width suspended sediment transport rate is the basis for calculating river sediment flux, which provides an important measure of river hydrology and morpho-dynamics. By integrating the vertical distribution of the suspended sediment concentration and logarithmic flow velocity, the formula for unit width suspended sediment transport rate is presented. Based on this formula, the calculation of the near-bed relative transport rate missing in field measurement is given. Moreover, a new stratified water sampling device is invented for suspended sediment transport rate measurement by the six-point method at Mengsheng hydrological station in the Lancang River basin. Results of 24 sets of measurements show that the near-bed relative sediment transport rate ranges from 3.4 to 10.7% and is significantly positively correlated with the suspension index. The unit width suspended sediment transport rate measured by the traditional depth integrating method is on average 15.0% smaller than that calculated by the theoretical formula, which can be a reference for correcting the sediment transport rate based on the traditional method. This work provides a new device and a new method for the measurement and calculation of the unit width transport rate of suspended sediment, which has theoretical and practical significance.

Development of Measurement Method for Temperature and Velocity Field with Optical Fiber Sensor.

We have developed a new method for measuring temperature and velocity at a high spatial resolution (minimum 2.56 mm pitch along an optical fiber). The developed method uses the same principle as a hot wire anemometer, where the velocity perpendicular to an optical fiber is estimated as a function of the cooling curve of a gold-coated layer on the optical fiber Joule-heated intermittently. The developed optical fiber sensor demonstrated the ability to acquire a transient velocity profile in airflow experiments with high repeatability and accuracy. This paper describes optical fiber-based velocity measurement in the velocity range of approximately 0-7 m/s with an error of approximately 10% compared to a hot wire anemometer and a new method for simultaneous temperature and velocity measurements. Applicability to velocity distribution measurements and seconds transient velocity changes are also described.

CO2 quantification in silicate glasses using µ-ATR FTIR spectroscopy

Abstract A new method for measurements of high-CO2 concentrations in silicate glasses was established using micro–attenuated total reflectance (µ-ATR) Fourier transform infrared (FTIR) spectroscopy in the mid-IR (MIR) region. We studied two glass/melt compositions, namely leucitite and granite, to cover samples in which CO2 is dissolved as carbonate ions (CO32−) or as CO2 molecules (CO3mol). In the leucitite glasses a carbonate absorption doublet with maxima at 1510 and 1430 cm–1 has shown to clearly separate from aluminosilicate lattice vibrations at lower wavenumbers. Due to the lower sensitivity of the µ-ATR method, we were able to measure high-CO2 contents (cCO2 &amp;gt;0.5 wt%) in experimental silicate glasses that would only be measurable with great difficulties using established transmission MIR measurements due to detector linearity limit effects even with very thin sample wafers. The peak heights of the 1430 cm–1 ATR band (A1430), normalized to the integral of the T-O lattice vibrations (T = Si, Al, Fe) at about 930 cm–1 (Int930) show a linear trend with CO2 contents in the range 0.2–4.3 wt%, yielding a linear correlation with cCO2 (wt%) = 0.4394 ± 0.006·A1430·10000/Int930. The normalization of the CO2 related band to a lattice vibration accounts for variations in the quality of contact between ATR crystal and sample, which has a direct effect on signal intensity. In granitic glasses, where CO2 is dissolved as CO3mol only, the asymmetric stretching vibration at 2350 cm–1 overlaps with the signal of atmospheric, gaseous CO2. As the ATR signal of dissolved CO2 is very weak, the atmospheric signal may dominate the spectrum. Since the absorbance spectrum is calculated by division of the single-channel sample spectrum by a single-channel reference spectrum measured in air, keeping the laboratory and spectrometer atmosphere as constant as possible during spectral acquisition can resolve the problem. Nonetheless, a procedure to subtract the signal of remaining atmospheric CO2 may still be required for the spectral evaluation. We studied a series of 5 granitic glasses with CO3mol contents of 0.08 to 0.27 wt% and found an excellent linear relation between CO2 concentration and lattice vibration normalized ATR intensity of the 2350 cm–1 band: cCO2 (wt%) = 0.2632 ± 0.0016·A2350·10000/Int990. Although the CO3mol concentrations in our granitic glass series can still be analyzed without major difficulties by conventional transmission IR spectroscopy, our data demonstrate the potential of the ATR method for samples with higher CO2 contents or for samples where a high spatial resolution is required (melt inclusions, vesicular or partially crystallized glasses). The lower limits of the ATR method are approximately 0.2 wt% CO2 dissolved as carbonate groups or 0.1 wt% CO2 (or slightly less) dissolved in molecular form.

Reliability and Validity Analysis of Pelvic Sagittal Inclination Calculated by Inverse Cosine Function Method on Pelvic Anteroposterior Radiographs.

ObjectiveEvaluation of sagittal pelvic tilt is significant for hip surgeons. However, the accurate measurement of pelvic sagittal inclination (PSI) is still a challenge. The objective of this study is to propose a new method for measurement of PSI from pelvic anteroposterior radiograph based on the inverse cosine function obtained from individualized pelvic model.MethodsCollecting the imaging data of 30 patients with both pelvic CT and full‐length spine radiographs. Establishing pelvic model by customized 3D reconstruction software. The length of three groups of longitudinal and transverse line segments (A′p and B′) were measured from full‐length spine anteroposterior radiographs. The corresponding anatomical parameters, including A, B, b, ∠α, ∠γ, were measured and calculated on the same patient's pelvic model. The estimated PSI (ePSI) based on three groups of anatomical landmarks, including ePSI‐1, ePSI‐2, and ePSI‐3, were calculated by equation, ePSI=arccosA′pb*B′−∠α, and compared with the actual PSI (aPSI) measured by Surgamap software. For the reliability and validation evaluation, three observers measured these parameters in two rounds. Intra‐class correlation and inter‐class correlation were both calculated. Bland–Altman method was used to evaluate the consistency between the estimated PSI (ePSI) and the actual PSI (aPSI).ResultsePSI‐1 and ePSI‐2 showed excellent intra‐observer reliability (0.921–0.997, p < 0.001) and inter‐observer reliability (0.801–0.977, p < 0.001). ePSI‐3 had a fair inter‐observer reliability (0.239–0.823, p < 0.001). ePSI‐1 showed the strongest correlation with aPSI (r = 0.917, p < 0.001). Mean (maximum) absolute difference of ePSI‐1, ePSI‐2, and ePSI‐3 is 2.62° (7.42°), 4.23° (13.78°), and 7.74° (31.47°), respectively. The proportion of cases with absolute difference less than 5° in three groups were 86.7% (ePSI‐1), 66.7% (ePSI‐2), 56.7% (ePSI‐3).ConclusionThis new method based on inverse cosine function has good reliability and validity when used in the evaluation of PSI on pelvic anteroposterior radiographs.

Media and Women Elite Athletes in the Arab World: Current Status and Perspectives for Developments

Media coverage of elite sport dates back to the 1960s, and ever since, media coverage of sport has been highly prevalent. This significant relationship has an impact on many factors including the social status of elite athletes. Thus, this paper first highlights the growth of media popularity in elite sport, and then proposes a new method of measurement of the media popularity of recognized sports, based on the methodology of the World Ranking of Countries in Elite Sport. This innovative index will allow the identification of the most popular sports around the world within the Arab context. After providing this data, this paper seeks to evaluate whether the popular sports indeed provide social advantages to the elite athletes who practice them, and to estimate accurately the impact that media have on the development of elite sport. These concepts extend to show the disparities between media coverage of male and female athletes and its wider impact on the athlete, sport, and/or culture. Recommendations for development of media practices are noted, including the proposition to refer in media contexts to sportspersons as athletes, as opposed to the use of terms which reinforce stereotypical divisions (male vs. female) thus challenging the reinforcing of gender stereotypes within the media.

MATH MODEL OF RUNNING INDEX FOR EVALUATION AND CONTROL OF SPECIFIC EFFICIENCY AND TRACING THE FATIGUE LEVEL IN LONG-DISTANCE RUNNING

The aim of this case study was to develop and verify a math model of running index (RI) for evaluation and control of specific efficiency and tracing the fatigue level in long-distance running. The suggested RI was modeled on the basis of polynomial function between the running velocity and the change in heart rate frequency (V=f(HR)). The method was designed in such a way that the influence of denivelation of the terrain was removed when calculating RI. The research was done among 19 highly qualified athletes competing in long-distance running events (16 men and 3 women), with a mean age of 28 years (SD±8), BMI 20 (SD±2), maximum oxygen consumption 67 ml/min/kg (SD ±5). The participants in the research were subjected to two lab and two terrain surveys. In a period of one week after the testing, RI was traced and calculated on the basis of the data taken from the major training loads. The model was verified only for the studied subjects - highly qualified competitors in long-distance running. RI was tested for validity through comparing the values obtained from the lab and terrain tests. The obtained results showed there was no significant difference between the values of RI measured during the lab testing and the terrain testing compared to the values of the velocity of ventilatory and lactate anaerobic threshold (VAnT). The results from this research revealed that the suggested method for calculation of the running index is more accurate than the previous ones. This manuscript discusses the possible implications of this new method for measurement of RI. Future scientific research is needed to prove its efficiency and applicability in sports.

Development of a New Related Substance by HPLC Method for Vildagliptin for Quantification of Purity

Using a simple, quick, precise, and cost-effective approach, a new method for measurement of Vildagliptin in Active Pharma Ingredient (API) besides its relative substance was developed and validated. This method is simple, rapid, exact and cost-effective. With isocratic elution of buffer acetonitrile and methanol in the proportions of (87:10:3 v/v/v), the chromatographic separation was done on an ODS-4 C18 column (3 m 250 4.6 mm) using a 4.6-millimeter ODS-4 C18 column. Using a photodiode array (PDA) detector, we measured the flow rate of one milliliter per minute (ml/min), the column temperature of fifty degrees Celsius, and the detection wavelength of two hundred and ten nanometers (nm). Vildagliptin has a theoretical plate of 8000 and a tailing factor of 1.38, making it one of the most potent drugs available. The approach was validated in compliance with the International Conference on Harmonization (ICH) and the Food and Drug Administration (FDA) requirements. Precision, accuracy, and resilience were all high on the list of desirable characteristics.

A new “practical" plane for Eustachian tube measurements and its application in predicting middle ear dysfunction in patient with acquired cholesteatomas

SettingThe Eustachian tube plays a vital role in middle ear physiology. There has been evidence that Eustachian tube (ET) and angle are correlated with middle ear function. The measurements of these Eustachian tube features are now made possible with computed tomography and multiplanar reconstruction techniques. However, there has not been a standardised protocol devised to these measurements in limited window cone-beam CT scans of temporal bones.ObjectiveThe primary object of the present study is to establish and validate a new landmark in closer proximity to the middle ear that is consistently captured, thereby allowing ET angle and length to be measured from the majority of cone-beam CT scans. Secondarily, the ET anatomies of patients with middle ear dysfunction manifesting as acquired cholesteatoma are analysed with this new method of measurement.MethodsThis study undertook a step-by-step method to first validate the methods of ET measurement with Reid’s standard plane, then identifying an alternative landmark, thus a new plane visible on limited window cone-beam CT scans of temporal bones and lastly, validating the application of this new plane in the measurements of ET angle and length. This new method of measurement was coined the Ku-Copson plane and was applied to 30 cochlear implant patients and 30 patients with acquired cholesteatomas. Their ET anatomies were analysed and compared.ResultsIt was found that the new Ku-Copson mandibular fossa plane was a reliable and accurate plane for the measurement of ET angle and length. Furthermore, it was found that patients with acquired cholesteatomas have statistically significant smaller ET angles and shorter ET lengths when compared with patients with cochlear implants, of normal middle ear function.ConclusionThe newly proposed method utilising the right mandibular fossa as an anatomical landmark for ET angles and lengths measurement appears to be viable. The close proximity of this landmark to the middle ear means that it is highly likely to be captured in most cone-beam CT scans of the petrous temporal bones. This enables the retrospective examination ET angles and lengths to be conducted on CB CT scans. This study reports statistically significant difference in ET anatomy in patients with middle ear dysfunction.

Functionalization of an extended-gate field-effect transistor (EGFET) for bacteria detection

Traditional sensing technologies have drawbacks as they are time-consuming, cost-intensive, and do not attain the required accuracy and reproducibility. Therefore, new methods of measurements are necessary to improve the detection of bacteria. Well-established electrical measurement methods can connect high sensitive sensing systems with biological requirements. One approach is to functionalize an extended-gate field-effect transistor’s (EGFET) sensing area with modified porphyrins containing two different linkers. One linker connects the electrode surface with the porphyrin. The other linker bonds bacteria on the functional layer through a specific peptide chain. The negative charge on the surface of the cells regulates the surface potential which has an impact on the electrical behavior of the EGFET. The attendance of attached bacteria on the functionalized sensing area could successfully be detected.

Comparison of upper body alignment assessment in traditional and Aston paradigm

Introduction: From the past until now, many different methods have been tried to measure upper body abnormalities. The Aston evaluation model is one of these new methods of measurement. The purpose of this study is to compare the evaluation of upper body alignment in two traditional and Aston evaluation models. Materials and Methods: 60 students between 13 and 17 participated in this study. The craniovertebral method was used to evaluate forward head posture, the flexible ruler method was used to evaluate kyphosis and lordosis, and the Scoliometer was used to evaluate uneven shoulder and Scoliosis. A camera was also used to assess the upper direction of the trunk using the Aston model evaluation method. In this study, a non-parametric chi-square test was used to compare evaluations in the two methods. Results: The results of this study indicate that There is no significant difference between traditional and Aston measurements in assessing the alignment of the thoracic and lumbar spine in the sagittal and frontal plane. However, there is a significant difference between the two measurement methods in assessing the cervical spine and shoulder.

Measurement of the magnification and distortion of high-precision imaging system using dual-fiber point diffraction interferometer

Magnification and distortion are two important parameters for high-precision imaging systems. Point diffraction interferometers (PDIs) can measure the magnification, distortion, and wavefront aberration of imaging systems with high precision. However, determining the precise pinhole alignment of the classical PDI is difficult. A new method for measurement of the magnification and distortion based on a dual-fiber point diffraction interferometer (DFPDI) is proposed. The end faces of two fibers are placed on the object plane of the optics under test and imaged to the image plane. The distance between the image points in the x and y directions are proportional to the Z2 and Z3 Zernike coefficients of the wavefront measurement result, respectively. The measurements of the image placement shift and precise alignment of the point diffraction pinhole are realized rapidly with high accuracy. The feasibility of the method is verified experimentally. The wavefront aberration, magnification, and distortion of a 5 × reduction lens with numerical aperture (NA) of 0.3 is measured jointly. The measurement uncertainties (3σ) of the magnification in the x and y directions and distortion are 756 ppm, 793 ppm, and 0.233 μm, respectively. Error analysis shows that the position error of the object- and image-plane stages is the main error source. An improved measurement scheme with a pinhole–pinhole pairs array in the object plane and a pinhole–window pairs array in the image plane is proposed. The influence of the position errors of the stages is eliminated with optimized measurement procedure. The DFPDI’s measurement repeatability (3σ) of the Z2 and Z3 coefficients is 0.65 and 0.33 nm, respectively, corresponding measurement uncertainties (3σ) of the magnification (in the x and y directions) and distortion can reach 1.88 ppm, 1.69 ppm, and 0.812 nm, respectively.

Effect of Thickness on Fluorescence of Some Clinical Dental Ceramics.

Objectives: This study aimed to develop a new method for measurement of florescence and compare the fluorescence of some clinical dental ceramics in different thicknesses. Materials and Methods: Forty-eight samples of feldspathic (Vita VM9, A2), IPS e.max (Ivoclar HT, A2), zirconia (Korox Zircostar, A2) and Enamic (Vita A2) ceramics were used in this study in 0.5 and 1 mm thicknesses. The fluorescence of the samples was measured by using a developed technique. The results were analyzed by two-way ANOVA and Duncan post-hoc test. P<0.05 was considered significant. Results: Enamic, feldspathic and e.max ceramics had significantly different fluorescence in descending order (P=0.000). Fluorescence of ceramics increased with an increase in their thickness from 0.5 to 1 mm (P=0.007). Conclusion: The results confirmed the applicability of the presented method for measurement of fluorescence of dental ceramics. While, the thickness of restoration determines the concentration of the fluorescent agent, some additional technical information is required for justification of the observed trend in the studied ceramics.