scholarly journals A model sensitivity analysis to determine the most important physicochemical properties driving environmental fate and exposure of engineered nanoparticles

2019 ◽  
Vol 6 (7) ◽  
pp. 2049-2060 ◽  
Author(s):  
J. A. J. Meesters ◽  
W. J. G. M. Peijnenburg ◽  
A. J. Hendriks ◽  
D. Van de Meent ◽  
J. T. K. Quik
Keyword(s):  
Sensitivity Analysis ◽  
Physicochemical Properties ◽  
Rate Constant ◽  
Environmental Fate ◽  
Engineered Nanoparticles ◽  
Sensitivity Analyses ◽  
Transformation Rate ◽  
Model Sensitivity ◽  
Attachment Efficiency ◽  
Transformation Rate Constant

Sensitivity analyses indicate attachment efficiency and transformation rate constant are most important in modeling environmental fate of engineered nanoparticles.

scholarly journals Multimedia environmental fate and speciation of engineered nanoparticles: a probabilistic modeling approach

2016 ◽  
Vol 3 (4) ◽  
pp. 715-727 ◽  
Author(s):  
J. A. J. Meesters ◽  
J. T. K. Quik ◽  
A. A. Koelmans ◽  
A. J. Hendriks ◽  
D. van de Meent
Keyword(s):  
Physicochemical Properties ◽  
Environmental Exposure ◽  
Environmental Fate ◽  
Probabilistic Modeling ◽  
Natural Variability ◽  
Engineered Nanoparticles ◽  
Modeling Approach ◽  
Exposure Estimation ◽  
Environmental Systems

The robustness of novel multimedia fate models in environmental exposure estimation of engineered nanoparticles (ENPs) is clarified by evaluating uncertainties in the emission, physicochemical properties and natural variability in environmental systems.

scholarly journals Crystallization Kinetics Analysis of the Amorphouse Mg72Zn24Ca4 Alloy at the Isothermal Annealing Temperature of 507 K

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2815
Author(s):  
Janusz Lelito
Keyword(s):  
Metallic Glass ◽  
Crystallization Kinetics ◽  
Rate Constant ◽  
Crystallization Process ◽  
Annealing Temperature ◽  
Isothermal Annealing ◽  
Avrami Exponent ◽  
Induction Melting ◽  
Transformation Rate ◽  
Transformation Rate Constant

This paper presents tests of metallic glass based on Mg72Zn24Ca4 alloy. Metallic glass was made using induction melting and further injection on a rotating copper wheel. A differential scanning calorimeter (DSC) was used to investigate the phase transformation of an amorphous ribbon. The tests were carried out at an isothermal annealing temperature of 507 K. The Kolmogorov-Johnson-Mahl-Avrami-Evans model was used to analyze the crystallization kinetics of the amorphous Mg72Zn24Ca4 alloy. In this model, both Avrami’s exponent n and transformation rate constant K were analyzed. Both of these kinetic parameters were examined as a function of time and the solid fraction. The Avrami exponent n value at the beginning of the crystallization process has value n = 1.9 and at the end of the crystallization process has value n = 3.6. The kinetic constant K values change in the opposite way as the exponent n. At the beginning of the crystallization process the constant K has value K = 9.19 × 10−7 s−n (ln(K) = −13.9) and at the end of the crystallization process has the value K = 6.19 × 10−9 s−n (ln(K) = −18.9). These parameters behave similarly, analyzing them as a function of the duration of the isothermal transformation. The exponent n increases and the constant K decreases with the duration of the crystallization process. With such a change of the Avrami exponent n and the transformation rate constant K, the crystallization process is controlled by the 3D growth on predetermined nuclei. Because each metallic glass has a place for heterogeneous nucleation, so called pre-existing nuclei, in which nucleation is strengthened and the energy barrier is lowered. These nuclei along with possible surface-induced crystallization, lead to rapid nucleation at the beginning of the process, and therefore a larger transformed fraction than expected for purely uniform nucleation. These sites are used and saturated with time, followed mainly by homogeneous nucleation. In addition, such a high value of the Avrami exponent n at the end of the crystallization process can cause the impingement effect, heterogeneous distribution of nuclei and the diffusion-controlled grain growth in the Mg72Zn24Ca4 metallic glassy alloy.

scholarly journals IMMU-04. IMMUNE-RELATED ADVERSE EVENTS STRONGLY PREDICT SUPERIOR OUTCOMES IN BRAIN METASTASES PATIENTS RECEIVING LOCAL TREATMENT AND IMMUNE CHECKPOINT INHIBITORS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii105-ii105
Author(s):  
Alexander Hulsbergen ◽  
Asad Lak ◽  
Yu Tung Lo ◽  
Nayan Lamba ◽  
Steven Nagtegaal ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Adverse Events ◽  
Brain Metastases ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Local Treatment ◽  
Sensitivity Analyses ◽  
Immortal Time Bias ◽  
The Brain

Abstract INTRODUCTION In several cancers treated with immune checkpoint inhibitors (ICIs), a remarkable association between the occurrence of immune-related adverse events (irAEs) and superior oncological outcomes has been reported. This effect has hitherto not been reported in the brain. This study aimed to investigate the relation between irAEs and outcomes in brain metastases (BM) patients treated with both local treatment to the brain (LT; i.e. surgery and/or radiation) and ICIs. METHODS This study is a retrospective cohort analysis of patients treated for non-small cell lung cancer (NSCLC) BMs in a tertiary institution in Boston, MA. Outcomes of interest were overall survival (OS) and intracranial progression-free survival (IC-PFS), measured from the time of LT. Sensitivity analyses were performed to account for immortal time bias (i.e., patients who live longer receive more cycles of ICIs and thus have more opportunity to develop an irAE). RESULTS A total of 184 patients were included; 62 (33.7%) were treated with neurosurgical resection and 122 (66.3%) with upfront brain radiation. irAEs occurred in 62 patients (33.7%). After adjusting for lung-Graded Prognostic Assessment, type of LT, type of ICI, newly diagnosed vs. recurrent BM, BM size and number, targetable mutations, and smoking status, irAEs were strongly associated with better OS (HR 0.33, 95% CI 0.19 – 0.58, p < 0.0001) and IC-PFS (HR 0.41; 95% CI 0.26 – 0.65; p = 0.0001). Landmark analysis including only patients who received more than 3 cycles of ICI (n = 133) demonstrated similar results for OS and IC-PFS, as did sensitivity analysis adjusting for the number of cycles administered (HR range 0.36 – 0.51, all p-values < 0.02). CONCLUSIONS After adjusting for known prognostic factors, irAEs strongly predict superior outcomes after LT in NSCLC BM patients. Sensitivity analysis suggests that this is unlikely due to immortal time bias.

scholarly journals Stagnation point bionanofluid slip flow model: Sensitivity analysis

2021 ◽  
Vol 60 (6) ◽  
pp. 5227-5243
Author(s):  
Sze Qi Chan ◽  
Fazlina Aman ◽  
Syahira Mansur
Keyword(s):  
Sensitivity Analysis ◽  
Stagnation Point ◽  
Flow Model ◽  
Slip Flow ◽  
Model Sensitivity

Optimal tuned direct adaptive controller for seismic protecting of structures

2021 ◽  
pp. 1045389X2098878
Author(s):  
Amin Hosseini ◽  
Touraj Taghikhany ◽  
Milad Jahangiri
Keyword(s):  
Sensitivity Analysis ◽  
Adaptive Control ◽  
Optimization Problem ◽  
Adaptive Controller ◽  
Sensitivity Analyses ◽  
Building Structures ◽  
Building Structure ◽  
The Past ◽  
Innovative Method ◽  
Story Building

In the past few years, many studies have proved the efficiency of Simple Adaptive Control (SAC) in mitigating earthquakes’ damages to building structures. Nevertheless, the weighting matrices of this controller should be selected after a large number of sensitivity analyses. This step is time-consuming and it will not necessarily yield a controller with optimum performance. In the current study, an innovative method is introduced to tuning the SAC’s weighting matrices, which dispenses with excessive sensitivity analysis. In this regard, we try to define an optimization problem using intelligent evolutionary algorithm and utilized control indices in an objective function. The efficiency of the introduced method is investigated in 6-story building structure equipped with magnetorheological dampers under different seismic actions with and without uncertainty in the model of the proposed structure. The results indicate that the controller designed by the introduced method has a desirable performance under different conditions of uncertainty in the model. Furthermore, it improves the seismic performance of structure as compared to controllers designed through sensitivity analysis.

scholarly journals Sensitivity analysis of a coupled hydrodynamic-vegetation model using the effectively subsampled quadratures method (ESQM v5.2)

2017 ◽  
Vol 10 (12) ◽  
pp. 4511-4523 ◽  
Author(s):  
Tarandeep S. Kalra ◽  
Alfredo Aretxabaleta ◽  
Pranay Seshadri ◽  
Neil K. Ganju ◽  
Alexis Beudin
Keyword(s):  
Sensitivity Analysis ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Aquatic Vegetation ◽  
Three Dimensional ◽  
Sensitivity Analyses ◽  
Stem Density ◽  
Sobol Indices ◽  
Plant Stem ◽  
Wave Induced

Abstract. Coastal hydrodynamics can be greatly affected by the presence of submerged aquatic vegetation. The effect of vegetation has been incorporated into the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) modeling system. The vegetation implementation includes the plant-induced three-dimensional drag, in-canopy wave-induced streaming, and the production of turbulent kinetic energy by the presence of vegetation. In this study, we evaluate the sensitivity of the flow and wave dynamics to vegetation parameters using Sobol' indices and a least squares polynomial approach referred to as the Effective Quadratures method. This method reduces the number of simulations needed for evaluating Sobol' indices and provides a robust, practical, and efficient approach for the parameter sensitivity analysis. The evaluation of Sobol' indices shows that kinetic energy, turbulent kinetic energy, and water level changes are affected by plant stem density, height, and, to a lesser degree, diameter. Wave dissipation is mostly dependent on the variation in plant stem density. Performing sensitivity analyses for the vegetation module in COAWST provides guidance to optimize efforts and reduce exploration of parameter space for future observational and modeling work.

COST-EFFECTIVENESS ANALYSIS OF IVABRADINE IN TREATMENT OF PATIENTS WITH HEART FAILURE IN IRAN

2018 ◽  
Vol 34 (6) ◽  
pp. 576-583 ◽  
Author(s):  
Saeed Taheri ◽  
Elham Heidari ◽  
Mohammad Ali Aivazi ◽  
Mehran Shams-Beyranvand ◽  
Mehdi Varmaghani
Keyword(s):  
Heart Failure ◽  
Sensitivity Analysis ◽  
Cost Effectiveness ◽  
Incremental Cost ◽  
Transition Probabilities ◽  
Drug Acquisition ◽  
Sensitivity Analyses ◽  
Baseline Heart Rate ◽  
Life Years ◽  
The Cost

Objectives:This study aimed to assess the cost-effectiveness of ivabradine plus standard of care (SoC) in comparison with current SoC alone from the Iranian payer perspective.Methods:A cohort-based Markov model was developed to assess the incremental cost-effectiveness ratio (ICER) over a 10-year time horizon in a cohort of 1,000 patients. The baseline transition probabilities between New York Heart Association (NYHA), mortality rate, and hospitalization rate were extracted from the literature. The effect of ivabradine on mortality, hospitalization, and NYHA improvement or worsening were retrieved from the SHIFT study. The effectiveness was measured as quality-adjusted life-years (QALYs) using the utility values derived from Iranian Heart Failure Quality of Life study. Direct medical costs were obtained from hospital records and national tariffs. Deterministic and probabilistic sensitivity analyses were conducted to show the robustness of the model.Results:Ivabradine therapy was associated with an incremental cost per QALY of USD $5,437 (incremental cost of USD $2,207 and QALYs gained 0.41) versus SoC. The probabilistic sensitivity analysis showed that ivabradine is expected to have a 60 percent chance of being cost-effective accepting a threshold of USD $6,550 per QALY. Furthermore, deterministic sensitivity analysis indicated that the model is sensitive to the ivabradine drug acquisition cost.Conclusions:The cost-effectiveness model suggested that the addition of ivabradine to SoC therapy was associated with improved clinical outcomes along with increased costs. The analysis indicates that the clinical benefit of ivabradine can be achieved at a reasonable cost in eligible heart failure patients with sinus rhythm and a baseline heart rate ≥ 75 beats per minute (bpm).

scholarly journals OPERA models for predicting physicochemical properties and environmental fate endpoints

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Kamel Mansouri ◽  
Chris M. Grulke ◽  
Richard S. Judson ◽  
Antony J. Williams
Keyword(s):  
Physicochemical Properties ◽  
Environmental Fate
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