Deviation Of Curve Research Articles

Short communication: Comparison of 3 rapid methods for analysis of vitamin degradation compounds in fluid skim milk

Vitamin fortification of dairy products, including fluid milk and fortified whey protein beverages, is an industry standard but can lead to the development of off-flavor compounds that are difficult to extract and detect by instrumental methods. Previous work has identified these compounds and their specific role in off-flavors in skim milk, but efficient extraction and quantification of these compounds remains a challenge. Three rapid methods (stir bar sorptive extraction, solvent-assisted stir bar sorptive extraction, and solid-phase microextraction) were compared for their ability to effectively recover vitamin degradation volatiles from fluid skim milk. The performance of the 3 methods for detecting and quantifying vitamin degradation-related volatile compounds was determined by linear regression of standard curves prepared from spiked standards of 5 vitamin degradation volatiles, the reproducibility on the same day and between days as measured by the average relative standard deviation of each standard curve, and the limits of detection and quantitation. Measurement of vitamin degradation compounds in commercial pasteurized fortified skim milks was also conducted using each method. Detection of selected vitamin degradation volatiles was linear in skim milk (0.005-200 μg/kg). Coefficient of determination values differed between methods and compounds. Within-day and between-day percentage of relative standard deviation also varied with compound and method. Limits of detection and quantitation values for all methods except solid-phase microextraction were lower than concentrations of selected volatile compounds typically found in commercial milk. Solvent-assisted stir bar sorptive extraction with a 10-mL sample volume provided the most consistent detection of selected compounds in commercial milks. Based on linearity, relative standard deviation, and limits of detection and quantitation, cyclohexane solvent-assisted stir bar sorptive extraction with 10-mL sample volume is recommended for the quantitation of vitamin degradation-related volatiles in fluid skim milk.

Differentiation of glioblastoma from solitary brain metastases using radiomic machine-learning classifiers.

This study aimed to identify the optimal radiomic machine-learning classifier for differentiating glioblastoma (GBM) from solitary brain metastases (MET) preoperatively. Four hundred and twelve patients with solitary brain tumors (242 GBM and 170 solitary brain MET) were divided into training (n = 227) and test (n = 185) cohorts. Radiomic features extraction was performed with PyRadiomics software. In the training cohort, twelve feature selection methods and seven classification methods were evaluated to construct favorable radiomic machine-learning classifiers. The performance of the classifiers was evaluated using the mean area under the curve (AUC) and relative standard deviation in percentile (RSD). In the training cohort, thirteen classifiers had favorable predictive performances (AUC≥0.95 and RSD ≤6). In the test cohort, receiver operating characteristic (ROC) curve analysis revealed that support vector machines (SVM)+least absolute shrinkage and selection operator (LASSO) (AUC, 0.90) classifiers had the highest prediction efficacy. Furthermore, the clinical performance of the best classifier was superior to neuroradiologists in accuracy, sensitivity, and specificity. In conclusion, employing radiomic machine-learning technology could help neuroradiologist in differentiating GBM from solitary brain MET preoperatively.

Evaluation and measurement of heliostat misalignment in solar power plant using vector model.

Heliostat alignment evaluation is among the main issues in solar tower concentration plant operation and maintenance. This paper describes a novel method used to evaluate heliostat misalignment and its experimental verification. This method provides a different way of visualizing beam centroid pointing errors by generating the complete deviation curve for each axis. This, for example, would be useful for verifying a heliostat's correct alignment by using a measurement performed out of the receiver target, using these traces to calculate its reflection's expected location, given a known misalignment. This measurement could be performed during operation simply by including a reflective element in the heliostat and two detector arrays on the tower's surface. This model has been tested for various types of misalignments of a heliostat at different hours, dates, and heliostat locations. The simulation results have been validated by using an experimental setup at a scale of 1:100.

Microstructural analysis, optical and magnetic properties of nanocrystalline Ni doped Dy2O3

Abstract Nanocrystalline samples of undoped dysprosium oxide (Dy2O3) and Ni2+ doped Dy2O3 (Dy1.90Ni0.10O3-δ/DNO) are prepared by co-precipitation method. X-ray diffraction (XRD) analysis by Maud software confirmed the desired crystallographic phase of both samples and also the substitution of Ni2+ ion in Dy2O3 lattice. Absence of impurity is confirmed from Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR) and high resolution transmission electron microscope (HRTEM) analysis. Magnetization vs. field (M-H) loop of DNO recorded at 5 and 10 K shows clear hysteresis loop with magnetization ∼138.71 emu/g at 5 K and ∼121.52 emu/g at 10 K with applied magnetic field of 5 T. The deviation of inverse susceptibility vs. temperature curve from Curie-Weiss fitting below ∼30 K and also the deviation of initial magnetization data of M-H loop recorded at 30 K from linear fitting suggests that the DNO is in mixed paramagnetic and ferromagnetic phase at and below ∼30 K. Defect mediated ferromagnetic ordering found in DNO at low temperature, is analyzed by bound magnetic polaron model.

Fabrication and temperature dependent magnetic properties of Co-Ni nanotube arrays

Parallel arrays of Co-Ni nanotubes with external diameter of 150 nm, wall thickness of 20 nm, and length of about 0.8 μm were successfully fabricated in ion-track etched polycarbonate (PC) templates by electrochemical deposition. The morphology and composition of the nanotubes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Temperature dependent magnetic analyses were performed with superconducting quantum interference device (SQUID) magnetometer which indicate that saturation magnetization of the nanotubes follows modified Bloch's law in the range 80–300 K. An abrupt deviation of the experimental curve (increase in magnetization) was observed from the modified Bloch's law below 80 K, which can be attributed to the disordered surface spins in the nanotubes due to the finite size effects. Finally, it was found that coercivity measured at different temperatures follows Kneller's law within the premises of Stoner–Wohlfarth model for ferromagnetic nanostructures.

Energy efficiency analysis of wet compression systems through thermo-fluid dynamic considerations

Wet compression systems are deployed in gas turbine power plants for energy savings in the compressor. The system works by injecting fine water droplets in the form of mist into the air stream ahead of the compressor. The water droplets evaporate both before entering the compressor and within the compressor and reduce the air temperature by absorbing latent heat of evaporation. In this study, an analysis is done on two-phase compression of air-water droplet mixture. The work is focused on understanding the fundamental concepts associated with two-phase compression. Hence, a simple piston-cylinder system is used as the domain to simulate the compression of air-water droplet mixture. During the processes, the pressure, temperature and relative humidity inside the cylinder have been monitored. Parametric studies are then performed for various values of starting relative humidity of the air, overspray percentage of water droplets, droplet diameter, and compression speed of the piston. In these studies, the deviation of PV and TV curves from the dry air compression curves, resulting from latent heat of vaporizing droplets are investigated. The studies show that smaller droplets, higher overspray and slower compression speeds significantly reduces the compressor work requirement, thereby increasing cost savings and environmental benefits of power generation. Interestingly, it is seen that the effect of initial relative humidity of the working fluid on energy savings is minimal. The corresponding efficiencies achieved through wet compression process are determined and tabulated.

On deviations and spreads of entire curves

We consider the influence that the number of separated maximum points of entire curves has on their growth and value distribution. We give upper estimates of Petrenko’s deviation of entire curves in terms of the number of separated maximum points and shar

Dental arch monitoring by splines fitting error during orthodontic treatment using 3D digital models

Backrgound/Aim. Researchers in the field of dentistry have been conducting research into modelling and defining dental arches equitations. Nowadays, when 3D digital modelling is commonly utilized in dentistry, the approach to modelling, analysis and synthesis has changed. Clinical researches are related to aesthetic and functional analysis. The aim of this study was to increase repeatability and accuracy of defining and determining the coordinate system of the jaw as well as to defining mathematical criteria for monitoring and evaluating orthodontic treatment. Methods. In this study, we used the plaster models of the jaw, optical scanner with structured light, 3D digital models, computer aided design (CAD) engineering tools adjusting the coordinate system, spline fitting of 3rd, 4th, 5th, 6th, 7th and 8th degrees. Results. Splines of 3rd, 4th, 5th, 6th, 7th and 8th degrees were fitted from the initial state (K0) in all 10 successive controls (K1, K2, K3,?, K10). All splines were fitted through 12 points, from the right to the left side of the jaw: 6-5-4-3-2-1-1-2-3-4-5-6. Tabular and graphic presentations of the maximum and average deviation of dental arch fitting curves in successive controls were given. Conclusion. The parameters of the maximum and average errors of fitting curves converge the dental arch values that are lower than the accuracy of the used optical scanners. The average error of fitting provides a general picture of the entire dental arch at each stage of treatment. Maximum error fitting points at a specified tooth where the largest deviation. <br><br><font color="red"><b> This article has been corrected. Link to the correction <u><a href="http://dx.doi.org/10.2298/VSP190515051E">10.2298/VSP190515051E</a><u></b></font>

Stability constants of Cu(II) and Zn(II) Metal complexes with Ethambutol hydrochloride and Alanine, Glycine, Isoleucine and Phenylalanine amino acids

Stability constants of binary and ternary complexes of Cu(II) and Zn(II) transition metal ions with ethambutol hydrochloride drug (L) and alanine, glycine, isoleucine and phenyl alanine amino acids(R) have been determined potentiometrically at 300C temperature and 0.1 M ionic strength(NaClO4) in aqueous solution. The formations of complexes were confirmed from deviation of curves. Stability of complexes was discussed in terms of different relative stability parameters.

Extensive Validation of Gas Chromatographic Method for Determination of Esters in Wines Using Monolithic Materials as Preconcentration Step

A comprehensive validation of a quantitative method is a critical issue for food analysis, which requires reliable estimation of uncertainties influencing measurements. Esters as important contributors to fruity aroma generally affect quality of wine and its organoleptic features. In this study, a full validation of the method developed for quantification of esters with uncommon silica monolithic discs and gas chromatographic analysis is presented. Two types of sorbent modification and a few desorption solvents were tested for ester removal from wine samples. Uncertainty contributions from mass balance tolerance, purity of chemicals, volume measurements, calibration curve deviation and extraction procedure were included in the calculation of the combined uncertainty. The expanded uncertainty of ester determination ranged from 15 to 37% and was mainly affected by uncertainty of calibration curve. The proposed method provided a limit of detection and a limit of quantification of 0.005–0.168 μg/L and 0.018–0.560 μg/L, respectively. Additional measurements revealed a recovery range of 70–111%, average reproducibility of instrument response less than 4%, and repeatability of the method below 16% for most of esters.

Mesenteric lymphadenopathy in children with chronic abdominal pain

Background: Mesenteric lymphadenopathy is a common finding described by abdominal ultrasonography in children.Objective: To estimate incidence and significance of mesenteric lymphadenopathy (MLN) in children with chronic abdominal pain (CAP) as compared to healthy children. Method: A prospective observational study was conducted in the paediatric department of a tertiary care hospital. Cases included children of age group 5–15 years with CAP who were subjected to abdominal ultrasonography during the study period. Controls included children in whom abdominal sonography was performed for reasons other than abdominal pain. Descriptive statistics were used for the analysis of baseline characteristics of the study group. For the variables following normal distribution curve, mean and standard deviation were computed. The presence of enlarged nodes,their location, size and other significant findings were Recorded.Pearson’s Chi-square test was used to analyse categorical variables between groups.Results: Three hundred and eighteen children were enrolled in the study. After excluding those who did not meet the criteria, the final study population included 110 cases and 138 controls. CAP was almost equal in both sexes with male: female ratio of 1:1.07. Mesenteric lymph nodes were detected by ultrasonography in 84 (72.1%) cases and in 41 (13.4%) controls. Significant MLN (≥5 mm short axis or >10mm long axis) was present in 62 (56.4%) of 110 children with CAP, in contrast to 16 (11.6%) of 138 controls (p <0.001). Most common location of the nodes was in the right iliac fossa (79%) followed by peri-umbilical location (77.4%) Conclusion: MLN, with lymph nodes more than 5mm on their short axis, is a significant finding in children presenting with CAP.

The effect of P–T on the reaction between tonalitic melt and mantle lherzolite at 2–4 GPa and implications for evolution of North China Cratonic Lithosphere and generation of High Mg# andesite

To assess the effects of reaction factors (mainly P and T) on the mineral assemblage and chemical composition of residual minerals and reacted melt in the reaction between andesitic melt and mantle peridotite, we conducted experimental reactions between tonalitic melt and mantle lherzolite using a DS-3600 six-anvil apparatus at 2–4 GPa and 1250 °C–1400 °C. The reaction products contain two types of reaction vein: orthopyroxene(r) [r means this mineral generated in melt-peridotite reaction and located at reaction rim] + garnet(r) and orthopyroxene(r). The mineral assemblages of the reaction veins are controlled by the reaction P and T, which can be determined via the empirical discriminant function: Y = 3.33 × 10−6 T2–2.17 × 10−3 T − 0.5 − P (T in °C, P in GPa; Y ≥ 0: Opx veins form; Y < 0: Opx + Grt veins form). These two types of reaction vein match those found in mantle xenoliths in Mesozoic and Cenozoic magmas from the North China Craton (NCC), indicating that they were formed by similar processes. The melt–peridotite reaction (including P and T) also influences the chemical composition of the residual minerals in the experimental products, with the major element variations being similar to those of NCC lithospheric mantle evolution from Palaeozoic to Cenozoic. Based on the experimental results, olivine in xenoliths from depths of ~100 km (~3 GPa) has higher SiO2 and lower NiO and MnO contents than olivine in xenoliths from depths of ~130 km (~4 GPa), and orthopyroxene in xenoliths from depths of ~100 km has higher Mg#, higher CaO content, and lower NiO content than orthopyroxene in xenoliths from depths of ~130 km. The reacted-mantle xenoliths contain clinopyroxene that originated from cold (<1300 °C) and deep (~135 km) lithospheric mantle. The P–T conditions also control the chemical composition of the reacted melt. An increasing reaction pressure increases the SiO2 content, whereas an increasing reaction temperature reduces the SiO2 content. In combination with the varying Na2O and K2O contents of the parental magma, the reacted melt can yield almost all types of intermediate magma with high Mg# (Mg# = mol[Mg/(Mg + ∑Fe)], Mg# > 0.45) character. This variation in major element of the reacted melt agrees with field observations of Mesozoic high-Mg# andesitic rocks from the NCC, indicating similar causes of the variation in the major element contents. With respect to the trace element content of the reacted melt, a garnet content of 15%–20% produces a right deviation of the heavy rare earth element partition curve (chondrite-normalized) and substantially elevates the Sr/Y and LaN/YbN ratios, indicating an adakite-like reacted melt.

Extended dynamometry: reference values.

Grip strength is used as a measure of capacity in disability and personal injury claims. Although seemingly an objective measure, it is widely recognized that it is fallible to the effects of sub-maximal effort. We have developed an extended test protocol that uses the five positions of a Jamar dynamometer. The protocol mitigates the effect of inconsistency while retaining the ability to detect sub-maximal effort. Dynamometry was undertaken in 242 volunteers (male:female, 124:118) with a median age of 39 years (range 18-89, interquartile range 29-52). Normative values for consistency, curve deviation and variation from the expected curve pattern are provided. None of these measures were significantly affected by laterality, hand dominance, sex or age despite the effects of these variables on grip strength. The study defines the methodology and reference values to allow assessment of both the capacity of a patient and the reliability of the test for use in medicolegal practice. Level of evidence: II.

Analysis of Properties of Ramp Stress Relaxation Curves Produced by the Rabotnov Nonlinear Hereditary Theory

The possibilities and applicability limits of the Rabotnov physically nonlinear constitutive equation containing two arbitrary material functions for nonaging materials are investigated. Analytically examined are the general properties of the resulting stress relaxation curves with an initial stage of constant strain rate and their dependence on duration of the stage, strain rate, and characteristics of the two material functions. Investigated are the monotonicity and convexity intervals and asymptotics of the relaxation curves, the jump of stress derivative at the end of the initial stage, the character of convergence of the family of relaxation curves as duration of the initial stage tends to zero, and other properties. Found are estimates for the deviation of the relaxation curves with an initial stage from those obtained in an instantaneous loading, and it is proved that this deviation tends to zero if the time tends to infinity or duration of the initial stage approaches zero. Revealed are the necessary restrictions on both material functions that allow an adequate modeling of the typical properties of experimental stress relaxation curves. Indicated are the effects which principally cannot be described whatever the material functions used. The possibilities of the Rabotnov nonlinear constitutive equation are compared with those of the Boltzmann–Volterra linear viscoelasticity theory (which were generalized introducing a second material function), and the additional effects that can be described by the nonlinear theory owing to presence of the second material function in it.

Using Noise Level to Detect Frame Repetition Forgery in Video Frame Rate Up-Conversion

Frame repetition (FR) is a common temporal-domain tampering operator, which is often used to increase the frame rate of video sequences. Existing methods detect FR forgery by analyzing residual variation or similarity between video frames; however, these methods are easily interfered with by noise, affecting the stability of detection performance. This paper proposes a noise-level based detection method which detects the varying noise level over time to determine whether the video is forged by FR. Wavelet coefficients are first computed for each video frame, and median absolute deviation (MAD) of wavelet coefficients is used to estimate the standard deviation of Gaussian noise mixed in each video frame. Then, fast Fourier transform (FFT) is used to calculate the amplitude spectrum of the standard deviation curve of the video sequence, and to provide the peak-mean ratio (PMR) of the amplitude spectrum. Finally, according to the PMR obtained, a hard threshold decision is taken to determine whether the standard deviation bears periodicity in the temporal domain, in which way FR forgery can be automatically identified. The experimental results show that the proposed method ensures a large PMR for the forged video, and presents a better detection performance when compared with the existing detection methods.

Suppression of Dick Effect in Ramsey-CPT Atomic Clock by Interleaving Lock.

The Dick effect is one of the main limitations of short-term frequency stability for most atomic clocks operating in the pulsed mode. Rather than employing better local oscillators with ultralow phase noise, using the interleaving lock technique to eliminate the dead time is a promising approach to suppress the Dick effect. In this paper, we demonstrate the suppression of the Dick effect by the interleaving lock technique in a pulsed Ramsey-coherent population trapping clock with two identical Cs atomic ensembles. The Dick effect is expected to be reduced by a factor of 24 theoretically. The measured short-term Allan deviation is improved from at 1 s to at 1 s. What is even more remarkable is that the Allan deviation curve exhibits slope from 0.01 to 2 s.

Age determination using feldspar: Evaluating fading-correction model performance

The recent introduction of post-IR IRSL measurement protocols has prompted a resurgence in luminescence applications using feldspar, some of which are affected by anomalous fading related signal loss. Many fading-corrected feldspar ages are reported in the literature, however few of those ages have been corrected using the model of Huntley (2006) [Huntley, D.J., 2006. An explanation of the power-law decay of luminescence. Journal of Physics: Condensed Matter 18(4), 1359–1365]. Here we present a new R function that calculates fading-corrected ages using the model of Huntley (2006), implemented with either a single-saturating exponential (1EXP) or general-order kinetic (GOK) fit. We evaluate the performance of the model through (i) contrasting measured and modelled field saturation values for a suite of 41 published saturated samples, and (ii) through using the model to fading-correct feldspar ages of samples with independent age control. Our results indicate that when implemented with 1EXP this model has an accuracy of 10% for predicting sample saturation, but that independent ages may be overestimated when the model is used to fading-correct samples across a range of timescales. In contrast, providing that the dose response curve has been characterised beyond 600 Gy, implementing the Huntley (2006) model with a GOK fit yields accurate age estimations. Modelled age overestimation for 1EXP is associated with dose response curve deviation from a single-saturating exponential. Finally we contrast the laboratory measured light levels of a suite of 50 saturated samples with their corresponding fading rates. We show that these saturated samples may yield De values below 2D0, and thus that 2D0 is not an effective screening criterion for sample saturation where no anomalous fading correction is made.

A Modified Control Method of Robot Path Curve Deviation Based on Terminal Trajectory Tracking

The robot is affected by small disturbance in the path following motion, which can easily cause the path curve to deviate. A modified control method of robot path curve deviation based on terminal trajectory tracking is proposed. A path trajectory tracking grid model of robot is constructed in the hyperredundancy space, and the force control of the robot is analyzed by quantitative fusion. The adaptive admittance controller is used to correct the deviation of robot path curve, and the mechanical loading is carried out according to the robot and load transfer mechanism model, and the force closed loop is placed in the outer layer of the position control loop. The desired path trajectory is corrected by force feedback, and a linear interpolation optimization method is used to track the trajectory of robot path curve deviation, and the cubic spline curve is used to fit the control points. The robot path curve deviation correction control model is transformed into force following mode, and the robot path curve deviation correction is realized by using multi-degree-of-freedom coordinated control method. The simulation results show that, the proposed method has the advantages of high precision, good stability, good anti-disturbance ability, it can improve path optimization accuracy effectively.

Are LOD and LOQ Reliable Parameters for Sensitivity Evaluation of Spectroscopic Methods?

The limit of detection (LOD) and the limit of quantification (LOQ) are common parameters to assess the sensitivity of analytical methods. In this study, the LOD and LOQ of previously reported terbium sensitized analysis methods were calculated by different methods, and the results were compared with sensitivity parameters [lower limit of quantification (LLOQ)] of U.S. Food and Drug Administration guidelines. The details of the calibration curve and standard deviation of blank samples of three different terbium-sensitized luminescence methods for the quantification of mycophenolic acid, enrofloxacin, and silibinin were used for the calculation of LOD and LOQ. A comparison of LOD and LOQ values calculated by various methods and LLOQ shows a considerable difference. The significant difference of the calculated LOD and LOQ with various methods and LLOQ should be considered in the sensitivity evaluation of spectroscopic methods.

B-spline contour curve approximation and deformation analysis of complex ceramic core

Complex ceramic core is the critical part for manufacturing hollow turbine blade in the investment casting process. The complex geometry, small inner structures and high-precision requirements of ceramic cores make them difficult to fabricate, and the shape and dimensional accuracy of ceramic cores are very low in factory practice. To understand the deformation characteristics of ceramic cores, a noisy points recognition algorithm, an extraction method of measuring cross-section contour points and a B-spline iterative fitting algorithm using dominant points of chord deviation are proposed. First, the cross-section contour points were provided through registration, slicing and intersection methods. Second, the noisy points were deleted by convex noisy points and concave noisy points recognition algorithms. Third, the cross-section contour curve of the ceramic core was fitted through B-spline iterative fitting method with chord deviation dominant points. The curves fitted with chord deviation points and curves fitted with local maximum curvature points were compared with simulating data and scanning data, respectively, and the results show that B-spline fitting curve needs fewer chord deviation points than local maximum curvature points, 24.4% fewer in simulation validation and 12.5% fewer in experimental validation. In the end, the bending deformation, torsion deformation and shrinkage deformation errors of ceramic core are established by fitting contour curves of serial cross sections of the ceramic core.