7-parameter Model Research Articles

Theoretical and experimental study on the damage behavior of bolted joints under cyclic loads

This paper presents a quasi-static and dynamic experimental study on the damage behavior of bolted joints. It proposes a 7-parameter theoretical model to accurately describe the damage properties of bolted joints during both micro- and macro-slip stages under cyclic loads. Results from quasi-static experiments indicate that under the preload of 12.4 kN, a ratcheting effect is observed during the micro-slip stage, reflecting the cumulative plastic damage process at the bolted interface. The macro-slip force exhibits a linear decrease with increased loading cycles. In the initiation of macro-slip, energy dissipation exhibits unstable characteristics, manifested as an "S"-shaped curve in the energy dissipation-applied force relationship. The proposed model can well describe bolted joints' observed energy dissipation characteristics.

Uncertainty analysis of the electric vehicle potential for a household to enhance robustness in decision on the EV/V2H technologies

Electric vehicles (EVs) and vehicle-to-home (V2H) technologies are regarded as promising technologies for optimizing household energy management, particularly as valuable resources for optimizing the management of distributed photovoltaic (PV) generation. However, the potential of EVs and V2H for households is closely related to their usage behavior. As EVs and V2H technologies are big investments for a family, especially for families in rural area, their benefits for households need to be analyzed in an uncertain environment to obtain robust results and mitigate investment risks for households. To achieve this, this study builds a 7-parameter stochastic model to simulate random driving patterns and employs a mixed-integer linear programming model to derive the optimal solution for the household energy system. Subsequently, the potential value of EVs and V2H technologies for a household is assessed based on three key performance indicators: economic viability, carbon emissions reduction, and energy and power autonomy. The findings of this study demonstrate that the EV is a viable technology for significantly reducing household energy expenditures, lowering household carbon emissions, and enhancing household energy and power autonomy. Furthermore, the V2H technology can provide additional benefits by further reducing carbon emissions as well as increasing the autonomy of the household energy system. However, the impact of V2H technologies on household energy expenditures is limited. The above conclusions still hold when the EV travel behavior stochasticity is taken into account, but an unexpected finding is that EV travel behavior stochasticity has almost no effect on the economy and carbon emission indicators, while significantly affecting the autonomy of the household energy system. Further investigation uncovers that the external charging price plays a critical role in determining the potential of EV + V2H technology as both stationary and mobile energy storage for households. Additionally, it is observed that the impact of EV travel behavior stochasticity on household energy expenditures becomes pronounced as the external charging price decreases, which can assist families in making reasonable decisions on configuring emerging technologies, like EV and V2H.

Compact and accurate models for the diatomic potential energy

Two compact analytical models for the diatomic potential energy are presented and tested. The first (6-parameter) model represents a significant improvement on the extended Lennard-Jones (ELJ) function proposed by Hajigeorgiou [J. Mol. Spectrosc. 263, 101 (2010)], and the second (7-parameter) model is a modified Hulburt-Hirschfelder function. The adjustable parameters of the two functions can be determined either by an algebraic scheme that employs semiclassical expressions in terms of vibrational-rotational molecular constants, or by direct nonlinear least-squares fits to available numerical potential functions. Accuracy tests are carried out for a set of ground electronic states of 30 diatomic molecules. The two potential energy functions give accurate representations of the available numerical potential energy curves with average deviations over the 30 molecules of approximately 0.06% of D e, or 1 meV (∼ 8 cm−1). The best cases give average absolute deviations of 0.0002% of D e, or 0.007 meV (∼ 0.06 cm−1). Quantum-mechanical vibrational eigenvalues of the new potential representations are shown for selected molecules to agree very well with the experimental vibrational energies, with average absolute deviations of much less than 1 cm−1.

Estimating surface optical properties and thermal thrust for Galileo satellite body and solar panels

Precise orbit determination of GNSS (Global Navigation Satellite System) satellites requires accurate models of perturbing forces acting on the spacecraft, i.e., solar radiation pressure (SRP) and thermal radiation forces. With the officially published satellite metadata, the analytical box-wing model is usually used to describe most of the SRP accelerations and the rest is assumed to be compensated by estimating ECOM/ECOM2 (Empirical CODE Orbit Model) parameters. However, we find that the precision of Galileo satellite orbits shows notable degradation inside eclipse seasons for 3-day-arc solutions and 24-h predictions. For instance, the RMS (root-mean-square) of orbit misclosures increases by about a factor of two in the eclipse season when using the box-wing model as the a priori and the 5-parameter ECOM model on top. The reason is proven to be mostly due to ignoring imbalanced thermal radiation forces (i.e., radiator emission and thermal radiation of solar panels) as satellite thermal properties are unknown. These imbalanced thermal effects cannot be fully absorbed by the ECOM/ECOM2 parameters inside eclipse seasons because the earth’s shadowing of a satellite in orbit causes periodic changes of the thermal environment. To cope with this problem, we first estimate satellite optical and thermal parameters as part of orbit determination based on Galileo tracking data covering 1 year. Then, we add physical thermal radiation models for radiators and solar panels as part of the a priori model and evaluate the performance of different ECOM models in Galileo satellite orbit determination. As shown by orbit misclosures, 24-h orbit predictions and SLR (Satellite Laser Ranging) residuals, the 7-parameter ECOM2 model performs better than the 5-parameter ECOM and the 9-parameter ECOM2 model for Galileo satellites. When using the 7-parameter ECOM2 model on top, the impact of the radiator emission and the thermal radiation of solar panels on Galileo satellite orbits is about 1 and 2 cm, respectively, inside eclipse seasons for 3-day-arc solutions.

A Daily Water Balance Model Based on the Distribution Function Unifying Probability Distributed Model and the SCS Curve Number Method

A new daily water balance model is developed and tested in this paper. The new model has a similar model structure to the existing probability distributed rainfall runoff models (PDM), such as HyMOD. However, the model utilizes a new distribution function for soil water storage capacity, which leads to the SCS (Soil Conservation Service) curve number (CN) method when the initial soil water storage is set to zero. Therefore, the developed model is a unification of the PDM and CN methods and is called the PDM–CN model in this paper. Besides runoff modeling, the calculation of daily evaporation in the model is also dependent on the distribution function, since the spatial variability of soil water storage affects the catchment-scale evaporation. The generated runoff is partitioned into direct runoff and groundwater recharge, which are then routed through quick and slow storage tanks, respectively. Total discharge is the summation of quick flow from the quick storage tank and base flow from the slow storage tank. The new model with 5 parameters is applied to 92 catchments for simulating daily streamflow and evaporation and compared with AWMB, SACRAMENTO, and SIMHYD models. The performance of the model is slightly better than HyMOD but is not better compared with the 14-parameter model (SACRAMENTO) in the calibration, and does not perform as well in the validation period as the 7-parameter model (SIMHYD) in some areas, based on the NSE values. The linkage between the PDM–CN model and long-term water balance model is also presented, and a two-parameter mean annual water balance equation is derived from the proposed PDM–CN model.

A simplified 4-parameter model of volumetric capnograms improves calculations of airway dead space and slope of Phase III.

To evaluate a compact and easily interpretable 4-parameter model describing the shape of the volumetric capnogram, and the resulting estimates of anatomical dead space (VDAW) and Phase III (alveolar plateau) slope (SIII). Data from of 8 mildly-endotoxemic pre-acute respiratory distress syndrome sheep were fitted to the proposed 4-parameter model (4p) and a previously established 7-parameter model (7p). Root mean square error (RMSE) and Akaike information criterion (AIC), as well as VDAW and SIII derived from each model were compared. Confidence intervals for model's parameters, VDAW and SIII were estimated with a jackknife approach. RMSE values were similar (4p: 1.13 ± 0.01mmHg vs 7p: 1.14 ± 0.01mmHg) in the 791 breath cycles tested. However, the 7p overfitted the curve and had worse AIC in more than 50% of the cycles (p < 0.001). The large number of degrees of freedom also resulted in larger between-animal range of confidence intervals for 7p (VDAW: from 6.110-12 to 34ml, SIII: from 9.5310-7 to 1.80mmHg/ml) as compared to 4p (VDAW: from 0.019 to 0.15ml, SIII: from 3.910-4 to 0.011mmHg/ml). Mean differences between VDAW (2.1 ± 0.04ml) and SIII (0.047 ± 0.004mmHg/ml) from 7 and 4p were significant (p < 0.001), but within the observed cycle-by-cycle variability. The proposed 4-parameter model of the volumetric capnogram improves data fitting and estimation of VDAW and SIII as compared to the 7-parameter model of reference. These advantages support the use of the 4-parameter model in future research and clinical applications.

Prediction of incident heart failure by serum amino-terminal pro-B-type natriuretic peptide level in a community-based cohort.

We investigated which serum amino-terminal pro-B-type-natriuretic peptide (NT-proBNP) levels inform heart failure (HF) risk in a community-based population at increased cardiovascular disease (CVD) risk. Inclusion criteria were age ≥ 60 years with one or more of self-reported hypertension, diabetes, heart disease, abnormal heart rhythm, cerebrovascular disease, or renal impairment. Exclusion criteria were known HF, ejection fraction (EF) < 50%, or more than mild valve abnormality. NT-proBNP levels were measured in 3842 participants on enrolment. HF was diagnosed in 162 participants at a median of 4.5 (interquartile range 2.7-5.4) years after enrolment, 73 with HF with preserved EF (HFpEF), 53 with HF with reduced EF (HFrEF), and 36 with valvular HF (VHF). Areas under the receiver operating characteristic curve (AUC) for 5-year prediction of total HF were similar for NT-proBNP alone (0.79, 95% confidence interval 0.74-0.83) and a 7-parameter multivariable model (0.82, 0.77-0.86, P = 0.035). NT-proBNP cut-points of 11, 16, and 25 pmol/L for individuals aged 60-69, 70-79, and ≥ 80 years, respectively, achieved sensitivities > 76% and specificities of 47-69% for 5-year prediction of total HF in men and women in all three age groups. Sensitivities were ≥ 75% in most subgroups according to body mass index, estimated glomerular filtration rate, and the presence or absence of atrial fibrillation, pacemaker, or CVD, and for the prediction of HFpEF, HFrEF and VHF. Age-specific serum NT-proBNP levels inform prognosis, and hence therapeutic decisions, regarding HF risk in individuals at increased CVD risk.

Robust Landsat-based crop time series modelling

Reliable satellite monitoring of agriculture is often difficult because surface variations occur rapidly compared to the cloud-free satellite observation frequency. Harmonic time series models, i.e., superimposed sequences of sines and cosines, have an established provenance for fitting satellite vegetation index time series to coarse resolution satellite data, but their application to medium resolution Landsat data for crop monitoring has been limited. Non-linear harmonic models have been shown to perform well over agricultural sites using single-year Moderate Resolution Imaging Spectroradiometer (MODIS) time series, but have not been explored with Landsat data. The 2017 availability of Landsat Analysis Ready Data (ARD) over the United States provides the opportunity to investigate the utility of temporally rich Landsat data for 30 m pixel-level crop monitoring. In this paper, the capability of 5- and 7-parameter linear harmonic models and a 5-parameter non-linear harmonic model applied to a year of Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+) ARD is investigated. The analysis is undertaken over six sites, each defined by a 5000 × 5000 30 m pixel ARD tile, that together include the major conterminous United States (CONUS) crops identified by inspection of the United States Department of Agriculture (USDA) Cropland Data Layer (CDL). The model fits are evaluated as the root mean square difference (RMSD) between the fitted and the observed Landsat data. Considering locations with at least 21 annual Landsat observations, the 7-parameter linear harmonic model (tile mean crop NDVI RMSD values ranging from 0.052 to 0.072) and the 5-parameter non-linear harmonic model (tile mean crop NDVI RMSD values ranging from 0.054 to 0.074) are shown to be able to fit annual Landsat NDVI time series for most CONUS crops, whereas the 5-parameter linear harmonic model cannot (tile mean crop NDVI RMSD values ranging from 0.072 to 0.099). If there are between 15 and 20 annual Landsat observations, the 5-parameter non-linear harmonic model is recommended for fitting annual NDVI crop time series, and if there are ≥21 observations, then either the 5-parameter non-linear or the 7-parameter linear model can be used. The 7-parameter model had marginally smaller mean NDVI RMSD values but larger standard deviations than the 5-parameter non-linear model, likely due to the relative robustness of the non-linear model to over-fitting and oscillations. None of the models could reliably fit crops with multiple stages, such as alfalfa, that are insufficiently sampled using combined Landsat 5 TM and Landsat 7 ETM+ time series. Given the utility of the growing season peak NDVI for crop yield applications, the date and magnitude of the model fitted peak NDVI are compared to quantify model reporting differences. The differences between the 7-parameter linear and the 5-parameter non-linear harmonic models are not large. For each ARD tile, the mean absolute differences in the estimated peak NDVI days varied from <2 days in the northern ARD tiles, which had short growing seasons and similar crops, to less than a week for the other tiles except for nearly 10 days for the California tile that had longer growing seasons and more diverse crops including crops with multiple stages. The paper concludes with a discussion and recommendations for future research.

On the determination of transformation parameters between different ITRS realizations using Procrustes approach in Turkey

Abstract The International Terrestrial Reference Frame (ITRF) solutions that are published by the International Earth Rotation and Reference Systems Service (IERS) are annual realizations of the ITRS (International Terrestrial Reference System). The results expressed in two different ITRS realizations can be compared using the transformation parameters that provide a link between different ITRF solutions. Generally, the 7-parameter (the three translation parameters, three rotation parameters and one scale factor) Helmert transformation is employed to compute the transformation parameters. However, the number of transformation parameters can be increased for better understanding. For example, 3 different scale factors may be computed instead of one scale factor. In this paper, the 9-parameter (the three translation parameters, three rotation parameters and three scale factors) transformation model and its solution by Procrustes approach is considered. Transformation parameters between ITRF 05 and ITRF 08 for Turkey have been computed in both 7-parameter model and 9-parameter model and a numerical example has been given to understand the difference between two models in a better way. An explanation about the proposed methodology as a flow chart also has been shown in appendix.

A single-scan protocol for absolute D2/3 receptor quantification with [123I]IBZM SPECT

PurposeMolecular imaging of the D2/3 receptor is widely used in neuropsychiatric research. Non-displaceable binding potential (BPND) is a very popular quantitative index, defined as the product of the receptor concentration (Bavail) and the radiotracer affinity for the receptor (1/appKd). As the appKd is influenced by parameters such as the endogenous neurotransmitter dynamics, it often constitutes a confounding factor in research studies. A simplified method for absolute quantification of both these parameters would be of great interest in this context. Here, we describe the use of a partial saturation protocol that permits to produce an in vivo Scatchard plot and thus estimate Bavail and appKd separately, through a single dynamic SPECT session. To validate this approach, a multi-injection protocol is used for the full kinetic modeling of [123I]IBZM using a 3-tissue compartment, 7-parameter model (3T-7k). Finally, more “classic” BPND estimation methods are also validated against the results of the 3T-7k. MethodsTwenty-nine male rats were used. Binding parameters were estimated using the 3T-7k in a multi-injection protocol. A partial saturation protocol was applied at the region- and voxel-level and results were compared to those obtained with the 3T-7k model. The partial saturation protocol was applied after an adenovirus-mediated D2 receptor striatal overexpression and in an amphetamine-induced dopamine release paradigm. The Simplified Reference Tissue Model (SRTM), the Logan's non-invasive graphical analysis (LNIGA) and a simple standardized uptake ratio (SUR) method were equally applied. ResultsThe partial saturation experiments gave similar values as the 3T-7k both at the regional and voxel-level. After adenoviral-mediated D2-receptor overexpression, an increase in Bavail by approximately 18% was observed in the striatum. After amphetamine administration, a 16.93% decrease in Bavail (p<0.05) and a 39.12% increase (p<0.01) in appKd was observed. BPND derived from SRTM, LNIGA and SUR correlated well with the Bavail values from the 3T-7k (r=0.84, r=0.84 and r=0.83, respectively, p<0.0001 for all correlations). ConclusionA partial saturation protocol permits the non-invasive and time-efficient estimation of Bavail and appKd separately. Given the different biological phenomena that underlie these parameters, this method may be applied for the in-depth study of the dopaminergic system in translational molecular imaging studies. It can detect the biological variations in these parameters, dissociating the variations in receptor density (Bavail) from affinity (1/appKd), which reflects the interactions of the receptor with its endogenous ligand.

Application of spectral elements method to calculation of stress-strain state of anisotropic laminated shells

A model of a high-order triangular spectral shell element is presented to calculate a stress-strain state of a shell construction under small deformations considering the material inhomogeneity. Consideration of shear deformations, changes in the thickness of a shell is implemented through the use of 7-parameter model of shell elements. The results of problems solving are to illustrate the possibilities of the element.

A new twelve-parameter spectral/hp shell finite element for large deformation analysis of composite shells

In this paper, a new 12-parameter shell finite element for large deformation analysis of composite shell structures is developed using third-order thickness stretch kinematics. The continuum shell element is utilized in the numerical simulations of laminated composite and functionally graded materials, using a high-order spectral/hp approximations. The results obtained from the 12-parameter shell element are compared with those obtained from the 7-parameter shell element to bring out the differences. Deflections and maximum stresses are computed using the two models. The results show that the responses predicted by the two formulations (and models) are consistent with each other, with the 12-parameter model showing slight difference from those predicted by the 7-parameter model.

Geoid determination for the area of Poland by the least squares modification of Stokes_s formula

Previous geoid/quasigeoid models calculated for the area of Poland were based on the traditional “remove-compute-restore” procedure. One of the modifications of this method is the least squares modification of Stokes’ formula with additive corrections method (LSMSA), which was developed at the Royal Institute of Technology (KTH) in Stockholm in Sweden. The modified Stokes integral combines the regional terrestrial gravity data with a global geopotential model (GGM) giving the approximate geoid heights. To obtain the gravimetric geoid, four additive corrections, topographic, downward continuation, atmospheric and ellipsoidal, are calculated and applied. This paper presents the results of computation of a new gravimetric geoid model for Poland using the KTH method. In computations terrestrial gravity anomalies derived from nine different gravimetric data sets, global geopotential model EGM2008 and global elevation data SRTM v. 4.1 were used. The determined gravimetric geoid model was evaluated with GPS/levelling points of the Polish ASG-EUPOS network. After fitting the geoid model to the GPS/levelling data using a 7-parameter model, the standard deviation of differences was estimated to 2 cm. ARTICLE INFO

On computational shells with scale effects

The paper deals with the computations of so-called geometrically exact shells with scale effects. These type of computations are relevant to thin-walled structures at small scales (e.g. thin films, nanotubes etc.). The shell formulation exhibits higher order gradients and is developed following some author’s recent work on generalised continua. The framework has been modified as to account for two-dimensional surfaces as well. The shell formulation reduces to a standard one upon disregarding the higher gradient terms. The classical part of the formulation is a well known 7-parameter model previously developed by one of the authors which takes thickness change into account. The numerical treatment is based on a meshfree formulation which provides the necessary C1 continuity. As possible applications, dynamic buckling of cylindrical and spherical shells is investigated and some results for various states of loading and scale parameters are presented. The examples include also nanotubes of different dimensions where scale effects matter. The influence of the extra gradients is well demonstrated resulting in different buckling behaviours.

Abstract B215: Correlation of PSMA ADC exposure with reduction in tumor growth rate determined using serial PSA measurements from a Phase I clinical trial.

Abstract Background: PSMA ADC is a fully humanized antibody to PSMA conjugated to the potent microtubule disrupting agent monomethyl auristatin E (MMAE). The safety and PK of PSMA ADC as well as changes in PSA levels were evaluated in a Phase I dose escalation study in patients with taxane-refractory metastatic castration-resistant prostate cancer (mCRPC) (PSMA ADC 1301). Stein et al. (2010) has previously demonstrated correlation between growth rate derived from serial PSA measurements with survival in patients with mCRPC and suggested that growth rate could serve as a novel endpoint indicative of response to therapy and overall survival. Methods: The PK parameters for PSMA ADC, Total antibody (Ab) and free MMAE obtained from PSMA ADC Study 1301 (N=52) were calculated using non-compartmental analysis. The final data set contains 253 longitudinal PSA observations from 52 subjects dosed with 0.4-2.8 mg/kg PSMA ADC. The Stein model was re-expressed as a 7-parameter population model to describe the longitudinal PSA data which includes: Baseline PSA level (Y0), PSA decrease rate (D), PSA increase rate (G), inter-patient variability for Y0, G and D respectively, and residual variance. Model parameters were estimated using Phoenix/NLME®. Exposure-efficacy relationships and correlation between G and covariates were determined. Results: PSMA ADC, Total Ab, and MMAE exposure increased linearly with increasing PSMA ADC dose. Longitudinal PSA data were correctly fitted to the re-expressed Stein model. G continuously decreased with increasing PSMA ADC exposure, suggesting an exposure dependent drug effect. There was no apparent saturation of this effect at the maximum observed exposure, and no influence of age, baseline albumin and ALT/AST levels on G was evident. Conclusions: In a Phase I study where PSMA ADC (0.4-2.8 mg/kg) was administered to patients with mCRPC, we observed a correlation of PSMA ADC exposure with the reduction of G, suggesting that PSMA ADC may provide dose-dependent therapeutic benefit to subjects with mCRPC. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B215. Citation Format: Yakov Rotshteyn, F Mercier, R Bruno, Nancy Stambler, Robert J. Israel, Vivien Wong. Correlation of PSMA ADC exposure with reduction in tumor growth rate determined using serial PSA measurements from a Phase I clinical trial. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B215.

Dynamic crack propagation in elastoplastic thin‐walled structures: Modelling and validation

SUMMARYIn this paper, a method to analyse and predict crack propagation in thin‐walled structures subjected to large plastic deformations when loaded at high strain rates—such as impact and/or blast—has been proposed. To represent the crack propagation independently of the finite element discretisation, an extended finite element method based shell formulation has been employed. More precisely, an underlying 7‐parameter shell model formulation with extensible directors has been extended by locally introducing an additional displacement field, representing the displacement discontinuity independently of the mesh. Of special concern in the paper has been to find a proper balance between, level of detail and accuracy when representing the physics of the problem and, on the other hand, computational efficiency and robustness. To promote computational efficiency, an explicit time step scheme has been employed, which however has been discovered to generate unphysical oscillations in the response upon crack propagation. Therefore, special focus has been placed to investigate these oscillations as well as to find proper remedies. The paper is concluded with three numerical examples to verify and validate the proposed model.Copyright © 2013 John Wiley &amp; Sons, Ltd.

Correlation of PSMA ADC exposure with reduction in tumor growth rate determined using serial PSA measurements from a phase I clinical trial.

e16047 Background: PSMA ADC is a fully humanized antibody to PSMA conjugated to the potent microtubule disrupting agent monomethyl auristatin E (MMAE). The safety and PK of PSMA ADC as well as changes in PSA levels were evaluated in a phase I dose escalation study in patients with taxane-refractory metastatic castration-resistant prostate cancer (mCRPC) (PSMA ADC 1301). Stein et al. (2010) has previously demonstrated correlation between growth rate derived from serial PSA measurements with survival in patients with mCRPC and suggested that growth rate could serve as a novel endpoint indicative of response to therapy and overall survival. Methods: The PK parameters for PSMA ADC, Total antibody (Ab) and free MMAE obtained from PSMA ADC Study 1301 (N=52) were calculated using non-compartmental analysis. The final data set contains 253 longitudinal PSA observations from 52 subjects dosed with 0.4-2.8 mg/kg PSMA ADC. The Stein model was re-expressed as a 7-parameter population model to describe the longitudinal PSA data which includes: Baseline PSA level (Y0), PSA decrease rate (D), PSA increase rate (G), inter-patient variability for Y0, G and D respectively, and residual variance. Model parameters were estimated using Phoenix/NLME. Exposure-efficacy relationships and correlation between G and covariates were determined. Results: PSMA ADC, Total Ab, and MMAE exposure increased linearly with increasing PSMA ADC dose. Longitudinal PSA data were correctly fitted to the re-expressed Stein model. G continuously decreased with increasing PSMA ADC exposure, suggesting an exposure dependent drug effect. There was no apparent saturation of this effect at the maximum observed exposure, and no influence of age, baseline albumin and ALT/AST levels on G was evident. Conclusions: In a phase I study where PSMA ADC (0.4-2.8 mg/kg) was administered to patients with mCRPC, we observed a correlation of PSMA ADC exposure with the reduction of G, suggesting that PSMA ADC may provide dose-dependent therapeutic benefit to subjects with mCRPC.

Determination of standard target water quality in the Nakdong River basin for the total maximum daily load management system in Korea

This study suggests methods to improve the total maximum daily loads management system currently being regulated in Korea. The TANK model which is a conceptual rainfall-runoff model including the river routing function and the evapotranspiration process is adapted to simulate daily stream flows, and the 7-parameter log-linear model combined with the minimum variance unbiased estimator is used to calculate daily stream contaminant loads. Based on these methods, Load Duration Curves (LDCs) for each unit watershed are constructed. Using LDCs of all unit watersheds, representative specific LDC of Nakdong River is derived to indicate the average contaminant status of the whole river basin in terms of water quality items. Using representative specific LDCs, appropriate target water qualities with respect to reference flow conditions are assigned to all of unit watersheds, and point sources or non-point sources priority management areas of 40 unit watersheds of the Nakdong River basin are identified.

A hierarchic family of isogeometric shell finite elements

A hierarchic family of isogeometric shell finite elements based on NURBS shape functions is presented. In contrast to classical shell finite element formulations, inter-element continuity of at least C1 enables a unique and continuous representation of the surface normal within one NURBS patch. This does not only facilitate formulation of Kirchhoff–Love type shell models, for which the standard Galerkin weak form has a variational index of 2, but it also offers significant advantages for shear deformable (Reissner–Mindlin type) shells and higher order shell models. For a 5-parameter shell formulation with Reissner–Mindlin kinematics a hierarchic difference vector which accounts for shear deformations is superimposed onto the rotated Kirchhoff–Love type director of the deformed configuration. This split into bending and shear deformations in the shell kinematics results in an element formulation which is free from transverse shear locking without the need to apply further remedies like reduced integration, assumed natural strains or mixed finite element formulations. The third member of the hierarchy is a 7-parameter model including thickness change and allowing for application of unmodified three-dimensional constitutive laws. The phenomenon of curvature thickness locking, coming along with this kinematic extension, again is automatically avoided by the hierarchic difference vector concept without any further treatment. Membrane locking and in-plane shear locking are removed by two different approaches: firstly elimination via the Discrete Strain Gap (DSG) method and secondly removal of parasitic membrane strains using a hybrid-mixed method based on the Hellinger–Reissner variational principle. The hierarchic kinematic structure of the three different shell formulations allows a straightforward combination of these elements within one mesh and is thus the ideal basis for a model adaptive approach.

In-line near-infrared spectroscopy for the characterization of dispersion in polymer-clay nanocomposites

In-line Near-Infrared spectroscopy (NIR) is used to monitor clay dispersion in the polymer matrix during the preparation of polymer nanocomposites by melt-mixing in a batch mixer. Based on chemometrics principles, various single parameter calibration models employing data obtained from widely used nanocomposite dispersion characterization techniques are developed and their quality tested. Given the generally unsatisfactory outcome, multi-parameter calibration models are then assessed, a 7-parameter model encompassing factors derived from oscillatory rheometry, FT-IR and thermomechanical data yielding good results. Since the validity of the model outside the material/equipment/operating boundaries that were used to generate it was shown to be quite restricted, a second 7-parameter model is derived from a broader set of experimental data. Finally, the model is successfully applied to monitor in real time the evolution of clay dispersion with mixing time.