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In this paper, the graphical method for solving linear programming is extended in fuzzy environment. Here, we dealt with the fully fuzzy linear programming (FFLP) which involves fuzzy constraints and fuzzy objective. Determining and visualizing the fuzzy feasible space in the geometrical space is one of the novel contributions of this study. Defining fuzzy constraints as fuzzy lines and finding the nature of the point of intersection between fuzzy lines are also studied. The fuzzy constraints divide the geometrical into fuzzy half planes. Intersection of such fuzzy half planes yields a fuzzy convex hull. The optimal solution of fuzzy linear programming problem is obtained at an extreme point of this fuzzy convex hull. The results obtained from the proposed method are compared with existing methodologies. [ABSTRACT FROM AUTHOR]

A Mueller matrix covers all the polarization information of the measured sample, however the combination of its 16 elements is sometimes not intuitive enough to describe and identify the key characteristics of polarization changes. Within the Poincaré sphere system, this study achieves a spatial representation of the Mueller matrix: the Global-Polarization Stokes Ellipsoid (GPSE). With the help of Monte Carlo simulations combined with anisotropic tissue models, three basic characteristic parameters of GPSE are proposed and explained, where the V parameter represents polarization maintenance ability, and the E and D† parameters represent the degree of anisotropy. Furthermore, based on GPSE system, a dynamic analysis of skeletal muscle dehydration process demonstrates the monitoring effect of GPSE from an application perspective, while confirming its robustness and accuracy. [ABSTRACT FROM AUTHOR]

We propose a graphical method for classifying phases in gas chromatography using a selectivity map, which is a two-dimensional diagram on the polarity–hydrophilicity coordinates, based on the theoretical description of the selectivity of liquid phases by three-parameter characteristics. The three-parameter characteristic method uses an expression of the intermolecular interaction energy in terms of the contributions of nonpolar, polar, and hydrogen bonds in an asymptotic approximation obtained using the theory of generalized charges and a new quantum-mechanical concept of the energy and probability of hydrogen bond formation. An advantage of the method is that the parameters used in the mathematical expressions have physical meaning, are portable, and can be found without experimentation. Relationships between the characteristics of stationary phases and their structure are revealed. The selectivity map as a classification method enables gas chromatographic liquid stationary phases to be considered in the range from low polarity/low hydrophilic to high polarity/high hydrophilic phases. On the other hand, applying the principle of the similarity of properties in combination with the selectivity map ensures the selection of the most selective phase for the given analytes. This selection can be made a priori, without experimentation. An example is given of choosing a selective stationary phase for separating substances with similar properties using a selectivity map. [ABSTRACT FROM AUTHOR]

Reinforced concrete beams lose resistance at high temperatures and so as to guarantee their good performance, it is mandatory to consider this accidental action in design. As an alternative to the methods proposed by the European and Brazilian standards, above all the tabular method that, despite its simple application, limits calculations to a few pre-defined values, a new tool for fire design of these beams is proposed herein. A graphical method was developed with the Temperature Calculation and Design (TCD) software, which performs transient bi-dimensional thermo-structural analysis using the finite element method. The main variable of this method consists of the resistance to the bending moment of a heated cross-section. For its validation, the moment of four rectangular sections was determined according to four simplified methods. These results were compared among themselves and to those obtained by a more advanced method. They were all verified to lead to similar results. With regard to the TCD, whose results were used for the preparation of the graphical method, the maximum difference compared to a more advanced method was approximately 2.5%. After validation, graphs that associate the ratio between the applied moment in fire and the resistance to bending moment at ambient temperature to the fire resistance for different beams were created. These graphs present design solutions for more than 2300 beam models with T-shaped cross-sections in assorted lengths, heights, covers and reinforcement arrangements, both positive and negative. In the application examples, the results from the graphical method were generally more economic when compared to the tabular method of the fire design standards. [ABSTRACT FROM AUTHOR]

This paper introduces a more streamlined and convenient graphical approach to investigate the stability of fractional-order dynamical systems comprehensively. In particular, we focus on the utilization of Kharitonov theorem, renowned for robust stability analysis of incommensurate fractional-order systems in the presence of uncertainty. A novel graphical framework is illustrated, promising to streamline the stability analysis of such systems, which leads to reducing the computational burden. Using the proposed method, we can achieve the least possible Kharitonov polynomials among the existing methods to analyze the robust stability of the incommensurate fractional-order systems. To validate our approach, we perform numerical simulations on four illustrative examples, demonstrating its effectiveness. Simulation results underscore the real-world utility of our methodology, emphasizing its potential significance in fractional-order system analysis. [ABSTRACT FROM AUTHOR]

It is known that the one-dimensional (1D) compression behavior is commonly represented by the e-logp' curve, which is obtained from the oedometer test. Five numbers of mathematical models were adopted to best fit the experimental data from the consolidation test. It is observed that Fredlund and Xing (1994)'s (FX) model, which is commonly used for the representation of the soil–water characteristic curve (SWCC), gives the best performance in best fitting the experimental data of e-logp' curves. Subsequently, the graphical method is adopted to determine the pre-consolidation pressure (Pc) by adopting FX model. Consequently, the equations are proposed for the determination of the Pc of the soil from the fitting parameters in FX model. The proposed method provides an alternative method for the determination of the Pc. [ABSTRACT FROM AUTHOR]

Issues are examined in the calculation of the secondary currents of an arc in the implementation of single-phase auto-reclosing (SPAR) for elimination of unstable single-phase faults of 500 and 750-kV ultra-high-voltage lines. Dependences are shown for the backfeed arc extinguishment time, and the SPAR currentless pause recommended in the references, on the amplitude of the forced component of the secondary arc current. A graphical method is proposed for the calculation of secondary arc currents in ultra-high-voltage lines under the condition of SPAR currentless pause. The adequacy of the modeling of a backfeed arc was confirmed by a comparison of the calculated and experimental data from a 750-kV 525-km line. Examples are presented of the application of the graphical method proposed in this article for calculation of secondary backfeed arc currents in 500 kV lines of various length. The features of the implementation of SPAR in 300 and 1000 km lines are noted, and in particular, the effect of zero-power reactors connected to the neutral of the shunt reactors. An example of the implementation of SPAR using automatic phase shunting (APS) in a 500 km line is also examined. [ABSTRACT FROM AUTHOR]

The optimal dimensional relations in machining the cap of the rotary mechanism in an Acros 585 combine may be calculated by a graphical method. That clearly shows the dimensional chains and their relationships; permits formalized calculation of the dimensions, margins, and tolerances; and permits selection of appropriate basing and coordination options. In addition, the best sequence of surface machining may be identified, and the optimal technological process may be established. [ABSTRACT FROM AUTHOR]

This paper attempts to expand the graphical analysis concept proposed by Chen and Abousleiman (Géotechnique, 2022. https://doi.org/10.1680/jgeot.21.00172) to deduce the undrained expansion solution of a cylindrical cavity in shear strain-hardening Drucker–Prager frictional soil. Based on the geometrical representation of the stress state/path and strain increments in the deviatoric planes, it is shown that the deviatoric stress-Lode angle stress path can be desirably determined by solving a first-order differential equation for the stress ratio (deviatoric stress over mean effective stress) in term of the Lode angle. The essential cavity expansion curve may also be readily constructed by calculating the internal cavity pressure and the corresponding expanded cavity radius, respectively, through simple numerical integrations with respect to the same variable of stress ratio. In particular, the ultimate cavity pressure can be easily evaluated by directly integrating the expression for cavity pressure with the stress ratio up to its limiting value. Some numerical results obtained from the proposed graphical method are presented to illustrate the impacts on the cavity responses of the earth pressure coefficient at rest, K 0 , and the key plasticity hardening parameters, which have also been compared with alternative solutions that require dealing with a system of coupled differential equations involving three principal effective stress components. [ABSTRACT FROM AUTHOR]

Comparing the differences in outcomes (that is, in "dependent variables") between two subpopulations is often most informative when comparing outcomes only for individuals from the subpopulations who are similar according to "independent variables." The independent variables are generally known as "scores," as in propensity scores for matching or as in the probabilities predicted by statistical or machine-learned models, for example. If the outcomes are discrete, then some averaging is necessary to reduce the noise arising from the outcomes varying randomly over those discrete values in the observed data. The traditional method of averaging is to bin the data according to the scores and plot the average outcome in each bin against the average score in the bin. However, such binning can be rather arbitrary and yet greatly impacts the interpretation of displayed deviation between the subpopulations and assessment of its statistical significance. Fortunately, such binning is entirely unnecessary in plots of cumulative differences and in the associated scalar summary metrics that are analogous to the workhorse statistics of comparing probability distributions—those due to Kolmogorov and Smirnov and their refinements due to Kuiper. The present paper develops such cumulative methods for the common case in which no score of any member of the subpopulations being compared is exactly equal to the score of any other member of either subpopulation. [ABSTRACT FROM AUTHOR]

Based on the nonlinear algorithmic theory, the R-SVM water source discrimination model and prediction method were established by using the piper qualitatively to compare the differences between the ionic components and R-type factor approximation indicator input dimensions. Taking the mine water samples of Zhaogezhuang Coal Mine as an example, according to the chemical composition analysis of the water samples from different monitoring points, six indexes of Na+, Ca2+, Mg2+, Cl–, SO42– and HCO3– were selected as the discrimination factors. According to the water characteristics of each aquifer and the actual needs of discrimination, the water inrush sources in the mining area were divided into four categories: The goaf water is class I, Ordovician carbonate is class II, Sandstone fracture water from the 13 coal system is class III, and Sandstone fracture water from the 12 coal system is class IV. Taking 56 typical water inrush samples as training samples, 11 groups for prediction samples, establish the input index as typical ion content, output as water source type, using SPSS statistics and MATLAB to realize the R-SVM water source discriminant analysis model, automatically establishing the mapping relationship between the water quality indexes and the evaluation standards, which can achieve the purpose of rapid and accurate discrimination of the water sample data. The results showed that the accuracy of the R-SVM model classification was 90.90% in the verification of the water source discrimination example of Zhaogezhuang mine and the coupled model has high accuracy, good applicability and discriminant ability, and has certain guiding significance for the prevention and control of water damage and the related field work. [ABSTRACT FROM AUTHOR]

Flood routing in natural channels is essential to predict the location and the physical properties of the flood waves, which is very important for the design of hydraulic structures and flood control processes and strategies. For example, the flood routing gives accurate information on flood peak and the period of water level rise. In this context, this study employed Muskingum's graphical method along with other numerical methods [least interpolation, nonlinear regression, classical fourth-order Runge–Kutta, and improved bat algorithm (IBA)] to conduct a flood routing in the Euphrates River at Husaybah region (near the Iraqi-Syrian borders). The IBA, which is based on the chaotic search tool and it improves the population homogeneity and periodicity, was employed in this study to optimize the estimated values of the Muskingum model. The flood routing in this study was developed using a big enough hydrological data (from 1993 to 2017) from the records of the Euphrates River. The collected data were processed and analyzed using the MATLAB software (version 9.6). The results of the analysis indicated that all the numerical methods can acceptably estimate the parameters of the Muskingum's graphical method, but the IBA was the best method as it fits the data with the minimum errors. In terms of the sum of squared differences between the observed and expected discharges (SSQ) were as follows (in a descending order): Nonlinear regression (2.46), Runge–kutta method (2.38), Least squares method (2.28), Graphical method (2.21), IBA (1.36). [ABSTRACT FROM AUTHOR]

We introduce a novel approach to compute Compton amplitudes involving a fermion pair inspired by Hopf algebra amplitude constructions. This approach features a recursive relation employing quasi-shuffle sets, directly verifiable by massive factorization properties. We derive results for minimal gauge invariant color-kinematic numerators with physical massive poles using this method. We have also deduced a graphical method for deriving numerators that simplifies the numerator generation and eliminates redundancies, thus providing several computational advantages. [ABSTRACT FROM AUTHOR]

The Bayesian approach is applied to estimation of the Weibull-power law process (WPLP) parameters as an alternative to the maximum likelihood (ML) method in the case when the number of events is small. For the process model considered we propose to apply the independent Jeffreys prior distribution and we argue that this is a useful choice. Comparisons were also made between the accuracy of the estimators obtained and those obtained by using other priors—informative and weakly informative. The investigations show that the Bayesian approach in many cases of a fairly broad collection of WPLP models can lead to the Bayes estimators that are more accurate than the corresponding ML ones, when the number of events is small. The problem of fitting the WPLP models, based on ML and Bayes estimators, to some real data is also considered. It is shown that the TTT-concept, used in the reliability theory, is not fully useful for the WPLP models, and it may be so for some other trend-renewal processes. In order to assess the accuracy of the fitting to the real data considered, two other graphical methods are introduced. [ABSTRACT FROM AUTHOR]

Background: Reservoir bank collapse in loess areas may lead to the siltation of reservoir and bank retreat. Therefore, the study of reservoir bank collapse has practical significance. Almost of the bank collapse width prediction method were based on the classical graphical method which do not consider the process of bank collapse. But practice shows that this method can overestimate the width of bank collapse. Meanwhile, there are few studies specifically focused on the collapse of loess bank slopes. Methods: To improve the prediction method of loss bank collapse width, the influence of water depth, dry density and bank slope angle on loess bank collapse was studied by physical modelling. The bank collapse width and the morphology of the bank slope were recorded during the experiment. Results: The bank collapse width increases with the increase of water depth, increases with the increase of slope angle, and decreases with the increase of dry density. The modeling process shows that the loess bank collapse occurs firstly underwater, the erosion niche will be formed underwater, and then the above water slope is damaged. This process is repeated until the underwater accumulation slope reaches the stable state, and then bank collapse stops. After the bank collapse, the above water slope is polyline, while the underwater slope is curved. When the slope angle is less than 27°, the bank collapse will not occur, and when the slope angle is between 27° and 40°, the bank collapse type is abrasion type. When the slope angle is greater than 40°, the bank collapse type is dumping type or shear type. Based on this, the improved balanced alluvial accumulation approach was proposed, which considers the mechanical equilibrium of above water bank slope and the morphology of underwater slope. The new method can reflect the stage characteristics of loess bank collapse, which is more reasonable than the empirical graphical method. Conclusions: The experimental results indicate that when predicting the width of loess bank collapse, it is necessary to combine the bank collapse width and process of bank collapse. The relevant conclusions have a certain role in exploring the mechanism of loess bank collapse and bank collapse prediction methods. [ABSTRACT FROM AUTHOR]

In the detection of corrosion under insulation (CUI) using pulsed eddy current testing (PECT) method, it is of great significance to reduce the footprint of the probe for improving the spatial resolution to local corrosion. This paper presents a novel method to reduce the probe footprint by modifying the excitation coil into multiple sub-coils and driving them with sequential pulses of different delay time. Finite element simulations are conducted to reveal the underlying mechanism. It is found that by using the sequential excitation scheme, the diffusion and decay of eddy currents in the test piece are regulated, and both the footprint reduction and signal enhancement can be achieved. Afterwards, the effects of the sequence and the delay amount of the applying pulses on the probe footprint are analyzed. Results show that the optimal excitation sequence is to apply pulses with increasing delay time to the sub-coils from outside to inside; the probe footprint decreases with the increase of the delay amount. Experimental work is finally performed to verify the simulation results. A graphical method for measuring the probe footprint is proposed by moving the probe on a step wedge plate and plotting the evaluated thickness against the probe position. Footprint measurement results of a conventional probe and the presented 4-subcoil probe are compared. The effectiveness of the proposed method are validated and the differences between experimental and simulation results are analyzed. [ABSTRACT FROM AUTHOR]

An extended search for anomaly free matter coupled N = (1, 0) supergravity in six dimension is carried out by two different methods which we refer to as the graphical and rank methods. In the graphical method the anomaly free models are built from single gauge group models, called nodes, which can only have gravitational anomalies. We search for anomaly free theories with gauge groups G1 × … × Gn with n = 1, 2, … (any number of factors) and G1 × … × Gn × U(1)R where n = 1, 2, 3 and U(1)R is the R-symmetry group. While we primarily consider models with the tensor multiplet number nT = 1, we also provide some results for nT ≠ 1 with an unconstrained number of charged hypermultiplets. We find a large number of ungauged anomaly free theories. However, in the case of R-symmetry gauged models with nT = 1, in addition to the three known anomaly free theories with G1 × G2 × U(1)R type symmetry, we find only six new remarkably anomaly free models with symmetry groups of the form G1 × G2 × G3 × U(1)R. In the case of nT = 1 and ungauged models, excluding low rank group factors and considering only low lying representations, we find all anomaly free theories. Remarkably, the number of group factors does not exceed four in this class. The proof of completeness in this case relies on a bound which we establish for a parameter characterizing the difference between the number of non-singlet hypermultiplets and the dimension of the gauge group. [ABSTRACT FROM AUTHOR]

In the present study, a polydentate Schiff base bis (salicylidene)-1,2-diaminopropane (H2L) was synthesized and characterized by elemental analysis, FTIR spectroscopy, 1H-NMR, and 13C-NMR spectroscopy. Then, the synthesized Schiff base has been used as a new extracting agent for copper (II) ions from aqueous to the organic phase. The effects of process parameters such as contact time, pH of aqueous phase, and bis (salicylidene)-1,2-diaminopropane concentration were investigated. Percentage extraction (%E) and distribution coefficient (D′) were calculated to determine the extracting capability of the bis (salicylidene)-1,2-diaminopropane upon copper ions Cu+2. The optimum conditions of copper extraction have been established. The stoichiometry of the extracted species was ascertained by the graphical method of slope analysis; their equilibrium constant is also calculated at constant temperature (T = 293.2 K). [ABSTRACT FROM AUTHOR]

The article discusses a proposed graphical method for assessing soil shrink-swell susceptibility in a specific region of the Brazilian Amazon. The method requires data from liquid and plastic limit tests, as well as grain size analysis. However, the discussers highlight that the method's validity for soils in other regions of Brazil is yet to be verified. They also argue that the literature review in the article is outdated and suggest using the Free Swell Ratio (FSR) method, which is a simple laboratory method that accurately identifies and classifies expansive soils based on their degree of swell potential and dominant clay mineral type. The discussers believe that the FSR method is more effective and cost-effective compared to the proposed graphical method. [Extracted from the article]

Reservoir bank collapse is a type of hydrogeological phenomena encountered in hydropower projects, and its prediction remains a challenge. The reservoir bank collapse width in the loess area of China is predicted based on the empirical graphical method established by scholars from the Soviet Union; however, the prediction results are quite different from the actual value. In this study, a field investigation was conducted on the bank slope topography after reservoir bank collapse in a loess area. The results showed that the water bank slope remained vertical after the bank collapse, and the accumulation form of the underwater bank slope followed an exponential curve. When the ratio of the water depth to the bank slope height after bank collapse was less than 0.3, there was an accumulation bank slope above the water. When this ratio was greater than 0.3, the accumulation slope was underwater. Based on the water depth and bank slope height after bank collapse, a formula to predict the topography of the underwater accumulation slope was established. Combined with the characteristics of the post-collapse bank slope, a prediction method for loess bank slope collapse was established. The topography of the bank slope predicted by this method was consistent with the field investigation results. The physical and mechanical properties of the bank slope loess and the characteristics of the bank slope were considered, thus overcoming the shortcomings of the conventional graphical method based on empirical parameters. This study has practical significance for prediction of loess bank collapse. [ABSTRACT FROM AUTHOR]

Atmospheric dustfall is solid air pollutant, has a major impact on the environment and human health. The objective of this study was to investigate the microscopic characteristics and sources of atmospheric dustfall in open-pit mining coal resource-based city in the arid desert area of Northwest China. The characteristics of size and shape factors, variation of shape factors with size distribution, types of individual particles, and sources of atmospheric dustfall, which were collected in the open-pit mining area and surrounding areas, were analyzed by X-ray diffraction (XRD) and scanning electron microscopy coupled with an energy dispersive spectrometer (SEM–EDS) combined with graphical method and shape factors. The results showed that the atmospheric dustfall in all functional areas was dominated by coarse-grained particles. The shape of the atmospheric dustfall deviated from spherical shape, and with decreasing particle size, the difference in shape factors increased in each functional area. The EDS and XRD analyses indicated the presence of 13 types of particles. The sources were mainly local and included soil dust from each functional area; industrial dust, construction dust, biogenic impurities, fossil fuel combustion, wear products of motor vehicle parts, motor vehicle exhaust emissions, and emission and excreta from biological activities in each functional area except the desert area; emissions from a steel plant in the industrial area; coal-associated ore, coal dust, coal gangue emissions, and emissions from the spontaneous combustion of coal gangue in the open-pit mining area; secondary chemical crystallization products in the industrial area and the open-pit mining area; dust generated by vehicles abrading the surface of the off-mine coal road and in the open-pit mining area. [ABSTRACT FROM AUTHOR]

The accuracy in analysis of wind speed is very critical to assess wind potential at any site. Wind power potential has been estimated using statistical distribution methods at numerous places around the world. The main aim of this article is to analyse wind potential and to compare between metaheuristic optimization algorithms and numerical approaches utilising the wind data at various places in India measured from masts and remote sensing technologies. The Weibull distribution fitness test is calculated using real-time wind data from various locations. The optimal Weibull parameters are estimated using numerical methods such as empirical method of Justus, maximum likelihood method, graphical method, modified maximum likelihood method and Wind Atlas Analysis and Application Program (WAsP). Furthermore, to assess Weibull distribution function for different sites (onshore, nearshore and offshore) in India, the social spider optimization is compared to particle swarm optimization and genetic algorithm. To examine the accuracy of various approaches, further goodness-of-fit method is estimated. The mean power density is maximum for offshore, followed by nearshore and onshore site with 452.32 W/m2, 431.53 W/m2, and 283 W/m2, respectively, at 120 m height. WAsP approach outperforms other numerical approaches used in this work. When compared to the genetic algorithm, the social spider optimization and particle swarm optimization were shown to be more efficient. The suggested method is more accurate than the numerical approaches utilised for wind potential assessment, according to the results. [ABSTRACT FROM AUTHOR]

A previous paper of the author introduced a graphical method, allowing anyone interested to form one's own opinion on data published in the form of computer-maps to re-compute the map data by means of a simple and efficient use of commonly available computer-graphic products. This was shown to allow a data re-analysis of sound metrological quality—there applied to a NASA video concerning the ice coverage on the Earth's surface. In the present paper, the same procedure shows an efficient way to (re-)compute the annual value of the so-called Global Mean Surface Temperature (GMST)—a parameter normally provided by dedicated International Organizations, such as the ONU-supported IPCC—from whole-Earth maps of different types, often obtaining different results. A cartographic reason for this is given and discussed, explaining the differences found, some of which might have remained implicit in the published information. [ABSTRACT FROM AUTHOR]

Time of Concentration (TC) is a widely utilized time variable in hydrological studies. Various approaches exist to estimate TC, including direct measurements, empirical relations, and graphical method (GM). The GM is commonly regarded as a standard by researchers. Nevertheless, this approach faces obstacles due to the scarcity of records in many watersheds.. This research explores a novel technique for TC estimation, focusing on the examination and recommendation of two-dimensional (2D) hydraulic modeling. The proposed method leverages available satellite data to obtain the necessary input for the 2D simulation. Additionally, several empirical relations were evaluated for TC determination. The GM served as reference point for evaluating the results obtained from empirical relations and hydraulic modeling. To accomplish this, analysis was conducted on four distinct watersheds in Iran, comprising a total of 28 recorded rainfall-runoff data.. In numerical modeling, TC was defined as the duration required for a water parcel to traverse from the headwater to the outlet of a basin. In all studied watersheds, the maximum relative error between the benchmark (GM) and the 2-D modeling was limited to less than 10%. This observation establishes the reliability of hydraulic modeling as a viable method for TC calculation, particularly in ungauged watersheds where the GM cannot be employed. [ABSTRACT FROM AUTHOR]

Adsorbed natural gas (ANG) storage is a promising solution to the problem of uneven supply and consumption of natural gas. ANG storages are relatively simple, safe and do not require complex infrastructure. The paper investigates the properties of activated carbon of wood origin synthesized by the method of chemical activation, as well as the theoretical capacity and thermodynamic properties of ANG storage facilities equipped with this adsorbent. An original graphical method for calculating the parameters and processes of ANG storage facilities is presented using the example of synthesized active carbon. Various types of ANG storage charging are considered: adiabatic processes of charging with compressed and liquefied gas, isothermal and pseudo-isothermal processes. So adiabatic charging with liquefied gas allows reaching a storage capacity of 150 m3/m3 at a pressure of 3.5 MPa. A number of recommendations were made regarding the choice of the charging type from the standpoint of the ANG storage facility design. [ABSTRACT FROM AUTHOR]

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Background: The level of quadriceps strength (QS) generated in the supine or seated position is not similar. For QS follow-up from intensive care unit (ICU) stay to recovery, getting comparable measures is essential. This study aimed to develop and validate new equations for estimating QS in a given position based on the measurement taken in another one. Methods and results: Isometric QS was measured using a handheld dynamometer and a standardized protocol in a supine and in a seated position. In a first cohort of 77 healthy adults, two QS conversion equations were developed using a multivariate model integrating independent parameters such as age, sex, body mass index (BMI) and baseline QS. These equations were tested in two cohorts for external validation, using the interclass correlation coefficient (ICC) and Bland–Altman graphical method. Only one was validated in the second cohort (62 different healthy adults): the ICC was 0.87 (95% CI 0.59–0.94) and the bias was − 0.49 N/Kg (limits of agreement: − 1.76–0.78 N/kg). However, this equation did not perform well in the third cohort (50 ICU survivors): the ICC was 0.60 (95% CI 0.24–0.78), and the bias was − 0.53 N/Kg (limits of agreement: − 1.01–2.07 N/kg). Conclusions: As no conversion equation has been validated in the present study, repeated QS measurements should be performed strictly in the same standardized and documented position. [ABSTRACT FROM AUTHOR]

We consider various aspects of interaction of vortices with a barotropic flow. When a vortex interacts with a flow, there exist three variants of the flow-core behavior: rotation, nutational oscillations, and unlimited stretching. In the first two cases, the vortex remains a localized formation, such that the ellipse semiaxes undergo oscillations near certain average values. In the third case, the shape of the vortex varies as follows: one horizontal axis increases indefinitely and the second horizontal axis tends to zero so that the vertical size of the vortex does not change and the vortex itself stretches into a filament in top view, remaining ellipsoidal. As a result, vortex formations, which are called filaments, emerge in the ocean. They emerge from the vortices which are initially almost circular in the horizontal plane and represent structures stretched in one direction and having nonzero vorticity. In this work, an analytical and graphical method for determining the regimes of behavior of three-dimensional ellipsoidal vortices is proposed for the first time for an inhomogeneous horizontal current which is linear with respect to the horizontal coordinates. Conditions for inevitable stretching of the vortices into filaments are studied. It is established that the vortex stretching is manifested in spots (domains) on 60–67% of the world ocean surface and the characteristic dimensions of these spots amount to about 200 km. The vortex stretching into filaments ensures energy pumping from mesoscale processes to submesoscale ones. According to the global oceanic reanalysis GLORYS12V1, the domain distributions in the World Ocean are plotted. It is shown that irrespective of the spatial-averaging scales, the integral area of regions in which the mesoscale vortices can stretch into filaments is dominant. [ABSTRACT FROM AUTHOR]

Net-zero targets are not likely to be achievable without the use of negative emission technologies (NETs). Various energy planning tools rarely consider NETs for net-zero emissions planning. Marginal abatement cost (MAC) curves, which plot different emissions reduction options based on specific cost and cumulative emissions reduction, are popular tools for communication and decision support. However, this graphical approach is tedious and hard to use for the calculation of the total system cost. Hence, the automated marginal abatement cost (AMAC) method was recently developed to overcome the limitation of the graphical method. The AMAC was based on the MAC curve but implemented on an optimization platform, which allows it to set rigorous performance targets. In this work, the AMAC is extended for multi-period net-zero emissions planning. The methodology is illustrated with a case study of multiple fossil fuel power plants and two NETs (biochar and bioenergy with carbon capture and storage) with a three-decade planning horizon. In the baseline scenario, it is not possible to achieve net zero due to a deficit of 4.38 Mt CO2/y of negative emissions. The rest of the scenarios achieved net-zero emissions during their target period. Targeting net-zero emissions in every period is at a higher risk of obtaining extreme values of the total system cost ($ 13,824–32,046 M) compared to targeting net-zero emissions only in the last period ($ 10,312–27,116 M). Multi-period decision support models are critical because of the dynamic nature of inputs needed to achieve net-zero emissions. [ABSTRACT FROM AUTHOR]

This study aims to assess the climate change impact on the rainfall and temperature data of the Vadodara-Chhotaudepur district of India and to focus on the environmental challenges related to the rainfall and temperature in the present state of development, land use, industrialization, and urbanization. The study utilized nine trend analysis methods, namely linear regression (LR), Sen's robust slope estimator (SS), Mann–Kendall test (MK), Spearman's rank correlation (SRC), the trend-free pre-whitening (TFPW), variance correction approach by Hamed and Rao (1998) with MK test (MK-CF1), variance correction approach by Yue and Wang (2004) with MK test (MK-CF2), block bootstrap with MK test (BBS-MK), and graphical method as innovative trend analysis (ITA), applied on monthly, annual, and seasonal scales. Additionally, the study also employed four homogeneity analysis methods, including Pettitt's test, standard normal homogeneity test (SNHT), Buishand's test, and Von Neumann Ratio test (VNRTs). The IMD (Indian meteorological department) gridded long-term rainfall data from 1901 to 2019 and temperature data from 1951 to 2019 are used in the present study to assess the homogeneity and trends of the data series. Results showed a warming trend of maximum temperature (MaxT) and minimum temperature (MinT) at the monthly, annual, and seasonal time scale and significant (at 5%) warming trend in annual MinT in the entire study area. Annual rainfall showed negative trend in the study area with significant (at 5%) negative trend in eastern deforested area western industrial and area adjacent to thermal power station. The change point is detected in annual rainfall time series in eastern forest area in 1959 and western area in 1983, i.e., after development of the industries and commissioning of thermal power station in the western study area. The trend rate of MaxT and MinT has been recognized as 0.004 °C/year and 0.019 °C/year, respectively, for the data period of 1951 to 2019. The annual rainfall trend rate has been observed as −0.743 mm/year for the data range 1901 to 2019. All trend analysis methods revealed consistent results except MK-CF2 method, which portraits greater number of significant trends in trend analysis methods. [ABSTRACT FROM AUTHOR]

Seawater intrusion is a global phenomenon that affects the groundwater quality in coastal aquifers due to extensive urban developments associated with over-exploitation of groundwater resources for the activities such as drinking, industrial, and agricultural. Seawater intrusion poses a challenging environment for the freshwater management in coastal areas. Hence, present study is carried out in the coastal region of Mangaluru city, Karnataka, India, to investigate the possibility of the seawater intrusion. The study area is divided into six zones from the coast to inland and 35 groundwater samples were collected during each season of post-monsoon (Dec 2018–Jan 2019) and pre-monsoon (Mar 2020). Groundwater samples were analyzed for both in situ and laboratory water quality parameters. The seawater intrusion is assessed using the hydrochemical methods such as ionic ratio, index method, and graphical method. As per the results of Gibbs plot, hydrogeochemistry of the samples is influenced by rock-water interaction. The modified Piper identifies dominance of freshwater (Ca-HCO3 water type) in the inland areas (zones 3 to 6) and identifies slight intrusion (Na-Cl water type) in the near to the coastal line (zones 1 and 2). Further, the results of ionic ratio (Na/Cl; Ca/Mg; Ca/(HCO3 + SO4); and Cl/(HCO3 + CO3)), index method (BEX index), and graphical methods (EC v/s Cl plot, hydrochemical facies evaluation diagram) identify the influence of salinization due to seawater intrusion up to 2 km (zone 2) from coastal line. The findings of study help to establish a supportive base for the decision-makers for the improved coastal groundwater management. [ABSTRACT FROM AUTHOR]

Wind potential estimation is generally evaluated using two-parameter (k, c) Weibull distribution. Root Mean Square Error (RMSE), Coefficient of Determination (R2) and Relative Error (RE) are computed in order to comparatively analyse fourteen methods of determining Weibull parameters. They are the Graphical Method, the Standard Deviation Method, the Empirical Method of Justus, the Empirical Method of Lysen, the Energy Pattern Factor Method, the Maximum Likelihood Method, the Modified Maximum Likelihood Method, the Alternative Maximum Likelihood Method, the Least Square Method, the Weighted Least squares Method, the Curve Fitting Method, the Wind Variability Method, the Moroccan Method and the Median and Quartile Method. These methods have been applied on three different windy sites (slightly, moderately and very windy sites) with hourly wind data over a period of 10 years (2005–2014), measured at 10 m height. As a result, compared to the other methods, Energy Pattern Factor method is the more suitable method applicable to assess the Weibull parameters for all wind speeds. However, the values obtained from RMSE, R2 and RE tests revealed that the WVM and MoroM methods are not suitable while all other methods are acceptable for the estimation of k and c. parameters. The determination of the wind power density and the gap between the predicted standard deviation by each method and the measured standard deviation for all the sites highlighted the relevance of EPFM method and the others methods. Moreover, this work reveals that the Weibull shape factor k decrease with height above ground level, while that of the scale factor c increase with height. [ABSTRACT FROM AUTHOR]

The accurate selection of the wind speed distributions is crucial for a better utilisation of wind energy. The Weibull distribution is most commonly used distribution and hence its parameters need to be optimized. In this study five numerical methods, namely, maximum likelihood method (MLM), graphical method (GM), empirical method of Justus (EMJ), modified maximum likelihood method (MMLM) and wind atlas analysis and application program (WAsP) and three metaheuristic optimization algorithms, namely, social spider optimization (SSO), particle swarm optimization (PSO) and genetic algorithm (GA) are applied for estimating Weibull distribution parameters at three different locations (onshore—Kayathar, nearshore—Jafrabad and offshore—Gulf of Khambhat (GOK) in India and also comparison of numerical and optimization methods are employed to tune the optimal parameters. The accuracy of the methods was evaluated using three different statistical analysis techniques. As per the results, GOK has the maximum wind power density of 450.2 W/m2 compared to Jafrabad and Kayathar. It was observed that among the five methods used for Weibull parameters estimation, WAsP method presented a better curve fit with the histogram of the wind speed. The results shows that SSO and PSO presents a comparably better performance than GA in the term of accuracy on the basis of closeness to converged solution. [ABSTRACT FROM AUTHOR]

Tropical sapric peat originates from highly decomposed woods. It consists of organic particles with colloidal microstructure and jelly-like texture. The complex fabric influences the permeability and the rate of pore water dissipation. The objective of this paper is to measure the permeability of tropical sapric peat using the flexible wall permeameter procedure. A special preparation method is presented, where each specimen was isotropically compressed under different effective stresses using a modified triaxial apparatus and monitored for 2 days-long permeability tests. The results showed that the permeability decreases with time following a negative power function, indicating gradual progress from the transient to semi-steady states. A graphical method is proposed to separate the transient state and the semi-steady state flow phases and to determine a representative coefficient of permeability. The time taken to achieve the semi-steady state was correlated with the level of compression. There is a good statistical correlation between the coefficient of permeability and the log of effective stress. The tropical sapric peat reported in this study has a lower permeability-to-effective stress ratio when compared to the amorphous sapric peat data from the literature. The findings of this paper offer excellent measurements for academic and engineers to better understand the permeability behavior of tropical sapric peat. [ABSTRACT FROM AUTHOR]

The olive tree is one of the oldest fruit tree cultivars in the ancient world and is the primary source of edible oils and olives. Like many other plants, the olive tree is susceptible to cold stress, one of the most significant environmental stresses that can lead to reduced plant yield or cell death. In this study, the researchers implemented a graphical analysis of the genotype-by-trait (GT) biplot for the first time to identify cold-tolerant olive genotypes. The study was conducted at the Tarom Olive Research Station on 16 olive genotypes with 15 physiological and biochemical traits. According to the GT biplot, the first and second components explained 40% and 20%, and 60% of the total variance, respectively. Concerning the correlation between traits and proline as a criterion, the biplot ranking of different genotypes based on proline content revealed that Zard, Grossane, Abou-satl, Picual, Konservolia, Cornicabra, and Amin cultivars exhibited above-average proline content. Furthermore, Grossane, Cornicabra, Abou-satl, Picual, Zard, and Kaissy cultivars were simultaneously identified as superior based on a pair of proline and stomatal conduction traits. In contrast, the Koroneiki, Meshkat, and Direh cultivars ranked lowest when these two traits were evaluated simultaneously. The hypothetical ideal genotype indicated the genotype with the highest values based on all variables according to the biplot graphic method. Other genotypes were ranked based on their distance from this genotype; the cultivar closest to the hypothetical ideal genotype was Grossane, a cold-tolerant genotype. Next in line were the Abou-satl, Zard, Picual, Konservolia, Cornicabra, and Amin cultivars. This study demonstrates that the graphical method of GT biplot can be used effectively to identify superior genotypes for simultaneously improving several traits. [ABSTRACT FROM AUTHOR]

The production of powders with predetermined particle sizes is an important task in various branches of powder metallurgy and is especially relevant in additive manufacturing, where powders with an equivalent particle diameter smaller than 50 μm are used. The following parameters were calculated in the paper: theoretical gas flow speed to produce particles of required size by gas atomization of superheated fluid metal; specific flow rate of the metal flowing out of the metal tundish, and atomization nozzle parameters (such as critical and outlet cross-sectional areas and their ratio). Gas dynamics methods, being widespread in aviation engineering, were used to calculate the nozzle. The supersonic Laval nozzle parameters and gas dynamic parameters for atomization of the molten 10R6M5 tool steel were calculated at gauge gas pressures ranging from 0.5 to 2.0 MPa, allowing fine powders to be produced, including those with a particle size smaller than 50 μm. Graphical dependences were plotted to illustrate the theoretical speed at which particles of required size formed and the gas speed calculated as a function of the gas pressure before the atomization nozzle. A graphical method for determining the cross-sectional areas of the Laval nozzle and the inert gas flow speed for a given gauge pressure in the studied range was proposed. The following parameters for the production of 10R6M5 tool steel powders with a particle size smaller than 50 μm by gas atomization were established: gas flow speed at the nozzle outlet of 525 m/sec, temperature of –140°C, and pressure higher than 16.8 MPa. The calculated critical and outlet cross-sectional areas of the Laval nozzle were 110 and 290 mm2 and their ratio was 0.379. [ABSTRACT FROM AUTHOR]

This study analyzes the wind speed characteristics, compares the six different methods (graphical, method of moment, wind energy pattern factor, empirical method of Justus and Lysen, and maximum likelihood method) of estimating Weibull parameters and calculates wind power density using daily mean wind speed data collected, at a height of 2 m, over a period of seven and eight years for Jumla and Okhaldhunga, respectively. Wind data were estimated at a height of 50 m to calculate average wind speed, Weibull parameters, and wind power density. Based on the results, Jumla has an average monthly maximum wind speed of 9.78 m/s in June and minimum wind speed of 6.71 m/s in December, whereas Okhaldhunga has an average monthly maximum wind speed of 10.95 m/s in April and minimum wind speed of 4.52 m/s in October. Jumla has an average annual wind speed of 8.11 m/s while Okhaldhunga has an average annual wind speed of 6.89 m/s. The accuracy of estimation methods was statistically tested using root mean square error and coefficient of determination. The empirical method of Justus and Lysen was found to be the best performing while the graphical method performed the poorest. By using the best method, an average wind power density has been estimated as 336.07 W/m 2 and 326.73 W/m 2 for Jumla and Okhaldhunga, respectively, indicating that both locations belong to wind power class III and have a moderate potential for wind energy harvesting. [ABSTRACT FROM AUTHOR]

The traditional simplified model for ground pressure calculation is widely used in the anti-seismic design of shallow tunnels. However, it presents two obvious deficiencies, which are related to the block equilibrium and the additional seismic load respectively. A modified calculation model is proposed in this article by introducing the concept of slip angle, so that the deflection of potential slip planes and the distribution of ground pressure can be considered and further discussed. By combining the horizontal slice method and graphical method, a series of explicit formulas for calculating ground pressure are presented so that the vertical ground pressure, the rupture angle, and the lateral thrust can be calculated more accurately. The proposed modified model is compared with the existing model to validate the correctness of calculation results. The results show that the explicit formula of modified model could be reduced to Liu's formula when the potential slip planes are assumed to be vertical. Additionally, the sensitivity analyses on the vertical ground pressure, block volume, and distribution pattern of the lateral thrust are carefully investigated. The lateral thrusts acting on the left and right wedges distribute logarithmically and exponentially respectively, which implies that the distribution pattern is mainly affected by the direction of earthquake inertia force, while the cohesion and the friction angle merely influence the magnitude of lateral thrust to some extent. [ABSTRACT FROM AUTHOR]

In this paper, the distribution network reconfiguration with simultaneous capacitor switching, in the presence of wind generators, by Simulated Annealing is presented. IEEE 69 bus network is analyzed which has 69 nodes including the slack one and 73 branches, all of which can commutate. Following assumptions are made: load in nodes is changed according to Gauss distribution and wind generator power with Weibull one, every hour, then there are two wind generators of 200 kW maximum power each (10% of total, nominal active power load) and they can be allocated to any node but the slack one. The same is valid for the capacitor banks regarding allocation. This switching logic is unrealistic. On its basis more realistic one was issued with fixed nodes for allocation of wind generators and capacitor banks (the most frequently visited nodes), by Monte Carlo graphical method. Input power factor is to be greater than 0.85 which is not fulfilled with commencing configuration (from the start) so that allocation of capacitor banks is mandatory. Another constraint is that the network should not be overcompensated. Four realistic scenarios are investigated. In the first one only network with wind generators is analyzed and the rest are dedicated to all possible combinations of the regulation. The programme is automated indicating the price of configuration, generated banks, input data (active and reactive load, power and location of wind generators) and savings which change on an hourly basis. The wind generators are uniformly distributed in accordance with nodes (for the less realistic scenario) and generate only active power complying with Weibull distribution. The graphical results are presented for a 1008-h operation (operation in one thousand and eight hours, every hour different) and the analysis is done for a thousand and eight-hour work. The presented method shows that considerable savings can be achieved by simultaneous application of reconfiguration method and capacitor switching with already allocated wind generators. [ABSTRACT FROM AUTHOR]

Groundwater is an important water source for domestic, industrial, and agricultural use in the western part of Zoucheng, China. Understanding its hydrochemical characteristics and formation mechanisms is important for the sustainable development and utilization of groundwater. In this study, 36 water samples were collected during the wet and dry seasons, respectively, and the hydrochemical components such as K+, Na+, Ca2+, Mg2+, Cl−, SO42−, HCO3−, NO3−, F−, TH, and TDS were analyzed. A graphical method, correlation analysis, and principal component analysis were applied to explore the hydrochemical characteristics and evolution mechanisms of groundwater in the study area. The results show that the orders of the anion and cation concentrations of karst groundwater and pore groundwater are Ca2+ > Na+ > Mg2+ > K+ and HCO3− > SO42− > Cl− > NO3− > F−, respectively. On the whole, the karst groundwater quality is better than the pore groundwater quality, which in turn is better than the surface water quality. In addition, water quality in the dry season is better than water quality in the wet season for all the three water sources. The hydrochemical types of groundwater are complex and changeable. Compared with dry seasons, HCO3 and SO4 type water increase during the wet seasons, while the Cl type and Mg type water decrease. Na type is significantly more prevalent in pore groundwater than in karst groundwater. The chemical formations of karst groundwater and pore groundwater in the dry and wet seasons are mainly affected by water–rock interactions and human activities. [ABSTRACT FROM AUTHOR]

Nanosecond pulsed laser ablation (NPLA) is widely used in micromachining. However, during the machining process, the radial heat-affected zone (RHAZ) will deteriorate the machining quality and accuracy of the microgroove, which is the basic unit of the ridge surface used to reduce frictional resistance in spacecraft walls. Its effective prediction is crucial for the processing precision control of microgrooves to ensure the drag reduction performance of the ridge surface. For this reason, this paper proposes an effective method to predict the RHAZ width. TC4 titanium alloy, commonly used in aerospace, is the target material in this work. By comprehensively considering the thermal accumulation effect of laser pulses and the superimposability of the temperature field, and based on the point heat source method, a dynamic temperature distribution model in NPLA is established. Then, the RHAZ width is initially predicted by combining the graphical method and the definition of the heat-affected zone. Finally, to improve the prediction accuracy of the RHAZ width, a correction factor is obtained by the NPLA of microgrooves on TC4. The relative error between the predicted RHAZ width and observed values is less than 7% after introducing the correction factor, verifying the reliability and validity of the proposed prediction method for the RHAZ width. Furthermore, the RHAZ width in NPLA of TC4 is on the order of hundreds of microns, which should be considered to ensure its processing quality when the ridge surface is designed on TC4. The research method in this paper will guide the design of high-density functional patterns and their high-precision preparation and has significant engineering practical value. [ABSTRACT FROM AUTHOR]

The article discusses tectonic stresses determined in the West Sakhalin terrain using different tectonophysical methods. The reconstruction of the stress field in coal fields in Sakhalin is implemented using the graphical method of orientation finding of stress axes in fractures and faults (at 16 observation points). The supplementary on-site tectonophysical studies made it possible to estimate the preferred orientation of the main slickensides of different kinematics and to reconstruct on this basis the local stress tensors at 53 observation points. The typical stress state of the West Sakhalin terrain is horizontal tension. [ABSTRACT FROM AUTHOR]

Photocatalysed degradation of environmental contaminants is one of the most fashionable technologies in the purification of water because the method converts toxic products to nontoxic ones. In this study, a method has been developed to synthesize novel nanocomposites of Na-Ca-Al-Si oxides for the first time. The average surface area, pore volume and pore size for the novel product were 1742.55 m2/g, 0.3499 cc/g and 3.197 nm respectively. The crystal parameters were a = 7.1580 Å, b = 7.4520 Å, c = 7.7160 Å, α = 115.0600, β = 107.3220, γ = 100.4380, density (calculated) = 2.0 × 103g/cm3 and cell volume = 332.7 Å3 respectively. The average crystalline size deduced from the Scherrer equation (i.e. 6.9393 nm) was higher than the value of 1.024 nm obtained from the graphical method. The FTIR and UV spectra of the nanocomposites were unique and provided baseline information that characterises the new product. XRD profiling of the new product reveals the existent of a silica framework consisting of NaAlSi3O3 and CaAl2Si2O8 The synthesized nanocomposites is an effective photocatalyst for the degradation of methyl orange dye in water, with aoptimum efficiency of 96% at an initial dye concentration of 10 ppm, the adsorbent dosage of 0.5 g,contact time of 90 min and pH of 2.5. The Langmuir-Hinshelwood, modified Freundlich and pseudo-second kinetic models were significant in the description of the photocatalytic kinetics of the degraded dye molecules. [ABSTRACT FROM AUTHOR]

The author’s recent research papers, “Cumulative deviation of a subpopulation from the full population” and “A graphical method of cumulative differences between two subpopulations” (both published in volume 8 of Springer’s open-access Journal of Big Data during 2021), propose graphical methods and summary statistics, without extensively calibrating formal significance tests. The summary metrics and methods can measure the calibration of probabilistic predictions and can assess differences in responses between a subpopulation and the full population while controlling for a covariate or score via conditioning on it. These recently published papers construct significance tests based on the scalar summary statistics, but only sketch how to calibrate the attained significance levels (also known as “P-values”) for the tests. The present article reviews and synthesizes work spanning many decades in order to detail how to calibrate the P-values. The present paper presents computationally efficient, easily implemented numerical methods for evaluating properly calibrated P-values, together with rigorous mathematical proofs guaranteeing their accuracy, and illustrates and validates the methods with open-source software and numerical examples. [ABSTRACT FROM AUTHOR]

Composites with the (Bi, Fe, ◻)2(Fe, W)2O6O'δ composition (pyrochlore, hereinafter BFWO)/amorphous phase were obtained by hydrothermal-microwave synthesis in the Bi2O3–Fe2O3–WO3–(H2O) system and characterized. The degree of the amorphous phase transformation into crystalline BFWO was found to increase from ~0.08 to ~0.82 with an increase in isothermal exposure duration at 180°C from 1 s to 5 min. The type of this dependence correlates well with the nature of the change in the BFWO phase crystallites average size (estimated by the Williamson–Hall graphical method), which increases from 270(20) to ~600 nm. It is shown that two morphological motifs are found in all samples, one of which is represented by particles whose average size correlates with the average size of the BFWO phase crystallites, and the other is represented by agglomerates sized at ~100 nm and composed of particles of the amorphous phase. Large particles have a core-shell type structure, in which BFWO crystallites form the core, and the shell is composed of the amorphous phase. The band gap (Eg) of the obtained composite materials for direct allowed electronic transitions is in the range of 2.26‒2.40 eV and decreases with an increase in the fraction of the BFWO crystal phase in the composite. [ABSTRACT FROM AUTHOR]

The principal objective of the present work is to realize thermodynamic modeling and analysis of the Proton Ceramic Fuel Cell (PCFC); particular attention is given to evaluate and optimize the power density generated by PCFCs according to the electrolyte, anode, and cathode thicknesses, water content in the oxidant and fuel, operating temperature, current density, and voltage. To implement the thermodynamic model, the PCFC voltage is represented by the difference between the Nernst potential and the total voltage loss generated in the electrolyte and electrodes (ohmic, activation, and concentration overpotentials) during PCFC operation. A FORTRAN program is developed to study the impact of these parameters on PCFC power density. After comparing the obtained results in this investigation to those of literature that are measured experimentally, they are presented a good concordance with root mean square error (RMSE) and mean bias error of 0.0572 and 0.0058, respectively. The conducted optimization, in this work, is realized based on the graphical method. The most important conclusions are summed in two points, PCFC power density is proportional to the operating temperature, and it is inversely proportional to the electrolyte and electrodes thicknesses and fuel and air humidification. [ABSTRACT FROM AUTHOR]

The purpose of this study is to identify and characterize individual sources of pollutants such as PM10, SO2, NOx, and CO in the urban area in Karadeniz (Turkey) using the bivariate polar plots method. In addition, the relationship between the meteorological conditions and the pollutants was determined based on correlation analysis in the region. Bivariate polar plots are a graphical method used to demonstrate the dependence of pollutant concentrations on wind direction measured at stations. Thanks to these graphics, resource types and properties can be determined. Wind flow and pollution data were used to provide information on wind and pollutant interactions in the study area. As a result of the study, it was founded that the main source of pollutants is intensive anthropogenic activities such as urban, street traffic, agricultural activities, and natural resources. It has been concluded that the highway in the region is not an important source of pollutants. In addition, the pollutant relations were examined with meteorological data, and it was discovered that temperature and relative humidity were effective for all pollutants. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate a three-compartmental semi-physiological model for analysis of uptake clearance and efflux from brain tissue of the hydrophilic markers sucrose and mannitol, compared to non-compartmental techniques presuming unidirectional uptake. Methods: Stable isotope-labeled [13C]sucrose and [13C]mannitol (10 mg/kg each) were injected as IV bolus into the tail vein of awake young adult mice. Blood and brain samples were taken after different time intervals up to 8 h. Plasma and brain concentrations were quantified by UPLC-MS/MS. Brain uptake clearance (Kin) was analyzed using either the single-time point analysis, the multiple time point graphical method, or by fitting the parameters of a three-compartmental model that allows for symmetrical exchange across the blood-brain barrier and an additional brain efflux clearance. Results: The three-compartment model was able to describe the experimental data well, yielding estimates for Kin of sucrose and mannitol of 0.068 ± 0.005 and 0.146 ± 0.020 μl.min−1.g−1, respectively, which were significantly different (p < 0.01). The separate brain efflux clearance had values of 0.693 ± 0.106 (sucrose) and 0.881 ± 0.20 (mannitol) μl.min−1.g−1, which were not statistically different. Kin values obtained by single time point and multiple time point analyses were dependent on the terminal sampling time and showed declining values for later time points. Conclusions: Using the three-compartment model allows determination of Kin for small molecule hydrophilic markers with low blood-brain barrier permeability. It also provides, for the first time, an estimate of brain efflux after systemic administration of a marker, which likely represents bulk flow clearance from brain tissue. [ABSTRACT FROM AUTHOR]

Purpose: 4-18F-Fluoro-m-hydroxyphenethylguanidine (18F-4F-MHPG) and 3-18F-fluoro-p-hydroxyphenethylguanidine (18F-3F-PHPG) were developed for quantifying regional cardiac sympathetic nerve density using tracer kinetic analysis. The aim of this study was to evaluate their performance in cardiomyopathy patients. Methods: Eight cardiomyopathy patients were scanned with 18F-4F-MHPG and 18F-3F-PHPG. Also, regional resting perfusion was assessed with 13N-ammonia. 18F-4F-MHPG and 18F-3F-PHPG kinetics were analyzed using the Patlak graphical method to obtain Patlak slopes Kp (mL/min/g) as measures of regional nerve density. Patlak slope polar maps were used to evaluate the pattern and extent of cardiac denervation. For comparison, "retention index" (RI) values (mL blood/min/mL tissue) were also calculated and used to assess denervation. Perfusion polar maps were used to estimate the extent of hypoperfusion. Results: Patlak analysis of 18F-4F-MHPG and 18F-3F-PHPG kinetics was successful in all subjects, demonstrating the robustness of this approach in cardiomyopathy patients. Substantial regional denervation was observed in all subjects, ranging from 25 to 74% of the left ventricle. Denervation zones were equal to or larger than the size of corresponding areas of hypoperfusion. The two tracers provided comparable metrics of regional nerve density and the extent of left ventricular denervation. 18F-4F-MHPG exhibited faster liver clearance than 18F-3F-PHPG, reducing spillover from the liver into the inferior wall. 18F-4F-MHPG was also metabolized more consistently in plasma, which may allow application of population-averaged metabolite corrections. Conclusion: The advantages of 18F-4F-MHPG (more rapid liver clearance, more consistent metabolism in plasma) make it the better imaging agent to carry forward into future clinical studies in patients with cardiomyopathy. Trial registration: Registered at the ClinicalTrials.gov website (NCT02669563). URL:https://clinicaltrials.gov/ct2/show/NCT02669563 [ABSTRACT FROM AUTHOR]

Left-truncated data are often encountered in epidemiological cohort studies, where individuals are recruited according to a certain cross-sectional sampling criterion. Length-biased data, a special case of left-truncated data, assume that the incidence of the initial event follows a homogeneous Poisson process. In this article, we consider an analysis of length-biased and interval-censored data with a nonsusceptible fraction. We first point out the importance of a well-defined target population, which depends on the prior knowledge for the support of the failure times of susceptible individuals. Given the target population, we proceed with a length-biased sampling and draw valid inferences from a length-biased sample. When there is no covariate, we show that it suffices to consider a discrete version of the survival function for the susceptible individuals with jump points at the left endpoints of the censoring intervals when maximizing the full likelihood function, and propose an EM algorithm to obtain the nonparametric maximum likelihood estimates of nonsusceptible rate and the survival function of the susceptible individuals. We also develop a novel graphical method for assessing the stationarity assumption. When covariates are present, we consider the Cox proportional hazards model for the survival time of the susceptible individuals and the logistic regression model for the probability of being susceptible. We construct the full likelihood function and obtain the nonparametric maximum likelihood estimates of the regression parameters by employing the EM algorithm. The large sample properties of the estimates are established. The performance of the method is assessed by simulations. The proposed model and method are applied to data from an early-onset diabetes mellitus study. [ABSTRACT FROM AUTHOR]