scholarly journals Application of the Cumulative Kinetic Model in the Comminution of Critical Metal Ores

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 925 ◽  
Author(s):  
Victor Ciribeni ◽  
Regina Bertero ◽  
Andrea Tello ◽  
Matías Puerta ◽  
Enzo Avellá ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Mathematical Models ◽  
Kinetic Parameters ◽  
Standard Procedure ◽  
Work Index ◽  
Critical Metal ◽  
Simulation Based ◽  
Simplified Procedure ◽  
Rock Analysis

Over the last decades, several reliable mathematical models have been developed for simulating ore comminution processes and determining the Work Index. Since Fred Chester Bond developed the Work Index standard procedure in 1961, numerous attempts have been made to find simpler, faster, and economically more advantageous alternative tests. In this paper, a Bond test simulation based on the cumulative kinetic model (CKM) has been checked on a spreadsheet. The research has been accomplished by conventionally determining the kinetic parameters for some Ag and Au ores and for three pure minerals and one rock that are common constituents of the gangue rock. Analysis of the results obtained allowed to develop a simplified procedure for calculating the kinetic parameters and their application to Work Index determination through simulation.

scholarly journals Unveiling the Link between the Third Law of Comminution and the Grinding Kinetics Behaviour of Several Ores

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1079
Author(s):  
Victor Ciribeni ◽  
Juan M. Menéndez-Aguado ◽  
Regina Bertero ◽  
Andrea Tello ◽  
Enzo Avellá ◽  
...  
Keyword(s):  
Standard Procedure ◽  
Research Work ◽  
Excellent Correlation ◽  
The Third ◽  
Work Index ◽  
Bond Work Index ◽  
Laboratory Procedures ◽  
Grinding Kinetics ◽  
Definition Of ◽  
Index Estimation

As a continuation of a previous research work carried out to estimate the Bond work index (wi) by using a simulator based on the cumulative kinetic model (CKM), a deeper analysis was carried out to determine the link between the kinetic and energy parameters in the case of metalliferous and non-metallic ore samples. The results evidenced a relationship between the CKM kinetic parameter k and the grindability index gbp; and also with the wi, obtained following the standard procedure. An excellent correlation was obtained in both cases, posing the definition of alternative work index estimation tests with the advantages of more straightforward and quicker laboratory procedures.

Epistemic Opacity

2019 ◽  
pp. 98-131
Author(s):  
Johannes Lenhard
Keyword(s):  
Mathematical Models ◽  
Simulation Models ◽  
Scientific Understanding ◽  
The Other ◽  
Weak Version ◽  
Simulation Based ◽  
Lower Standard ◽  
Epistemic Standards ◽  
Epistemic Opacity ◽  
Experimental Runs

This chapter shows that—and how—simulation models are epistemically opaque. Nevertheless, it is argued, simulation models can provide a means to control dynamics. Researchers can employ a series of iterated (experimental) runs of the model and can learn to orient themselves within the model—even if the dynamics of the simulation remain (at least partly) opaque. Admittedly, such an acquaintance with the model falls short of the high epistemic standards usually ascribed to mathematical models. This lower standard is still sufficient, however, when the aim is controlled intervention in technological contexts. On the other hand, opacity has to be accepted if the option for control is to remain in any way open. This chapter closes by discussing whether epistemic opacity restricts simulation-based science to a pragmatic—“weak”—version of scientific understanding.

Kinetic modelling of the photocatalytic inactivation of bacteria

2010 ◽  
Vol 61 (6) ◽  
pp. 1547-1553 ◽  
Author(s):  
Javier Marugán ◽  
Rafael van Grieken ◽  
Alberto E. Cassano ◽  
Orlando M. Alfano
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Catalyst Concentration ◽  
Kinetic Modelling ◽  
Kinetic Constant ◽  
Water Disinfection ◽  
Radiation Absorption ◽  
Simple Modification ◽  
Model Based ◽  
Photocatalytic Inactivation

This work analyzes the kinetic modelling of the photocatalytic inactivation of E. coli in water using different types of kinetic models; from an empirical equation to an intrinsic kinetic model including explicit radiation absorption effects. Simple empirical equations lead to lower fitting errors, but require a total of 12 parameters to reproduce the results of four inactivation curves when the catalyst concentration was increased. Moreover, these parameters have no physical meaning and cannot be extrapolated to different experimental conditions. The use of a pseudo-mechanistic model based on a simplified reaction mechanism reduces the number of required kinetic parameters to 6, being the kinetic constant the only parameter that depends on the catalyst concentration. Finally, a simple modification of a kinetic model based on the intrinsic mechanism of photocatalytic reactions including explicit radiation absorption effects achieved the fitting of all the experiments with only three parameters. The main advantage of this approach is that the kinetic parameters estimated for the model become independent of the irradiation form, as well as the reactor size and its geometrical configuration, providing the necessary information for scaling-up and design of commercial-scale photoreactors for water disinfection.

Réaction oscillante de Belousov. 2. Etude d'un nouveau modèle cinétique

1977 ◽  
Vol 55 (17) ◽  
pp. 3147-3155 ◽  
Author(s):  
Guy Schmitz
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Analog Computer ◽  
Limiting Cycle ◽  
Oscillating Reaction

On the basis of our results dealing with the bromate-cerous reaction we propose and discuss a new kinetic model for the Belousov–Zhabotinskii oscillating reaction. The existence of a limiting cycle is shown with an analog computer for a set of semi-empirically chosen kinetic parameters.

scholarly journals Simulation of the Oxidation and Combustion of Mixed Diesel-Biodiesel Fuel

2018 ◽  
Vol 156 ◽  
pp. 03008
Author(s):  
Yuswan Muharam ◽  
Danny Leonardi ◽  
Alisya P Ramadhania
Keyword(s):  
Kinetic Model ◽  
Kinetic Models ◽  
Equivalence Ratio ◽  
Biodiesel Fuel ◽  
Ignition Delay Times ◽  
Simulation Based ◽  
Delay Times ◽  
Set Up ◽  
Biodiesel Fuels ◽  
Good Agreement

A comparative simulation-based research has been set up to obtain valid kinetic models of the oxidation and combustion of biodiesel surrogate and diesel surrogate, as well as mixed diesel-biodiesel surrogates which is used to predict their ignition delay times (IDT). The research consists of the development of the detailed kinetic models of the oxidation and combustion of biodiesel surrogate and diesel surrogate, the validation of the two models with the corresponding experimental IDT data, the merging and the validation of the two models for mixed diesel-biodiesel surrogates. The biodiesel surrogate kinetic model was validated with the experimental IDT data of methyl 9-decenoate at 20 atm and three equivalence ratios. The diesel surrogate kinetic model was validated with the experimental IDT data of n-hexadecane at the pressure ranging from 2 atm to 5 atm and the equivalence ratio of 1.0. The diesel-biodiesel surrogate kinetic model was validated with the experimental IDT data of real diesel-biodiesel fuels for four compositions and at 1.18 atm. The validation results of all models show that the models and the experiments are in good agreement.

Kinetics and Modelling of Bulk and Solution Diallyl Terephthalate Polymerization

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Iztok Hace
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Rate Constants ◽  
Chain Transfer ◽  
Average Molecular Weight ◽  
Propagation Rate ◽  
Reaction Conditions ◽  
Diffusion Limitations ◽  
Kinetics Of ◽  
Dicyclohexyl Peroxydicarbonate

Free radical polymerization kinetics of diallyl terephthalate (DAT) in solution was investigated with two different peroxide initiators: dicyclohexyl peroxydicarbonate (CHPC) and benzoyl peroxide (BPO) in temperature range from 50°C to 110°C, where ortho-xylene was used as a solvent. Conversion points were measured using Fourier Transform Infrared (FTIR) measurements. Previously developed kinetic model for bulk DAT polymerization, was extended to solution DAT polymerization. The ratio of solvent chain - transfer rate constants to propagation rate constants of the polymerization system were found between 1.25 10-4 to 1.68 10-4 for various reaction conditions. They were obtained using the calculated initial polymerization rates and the number average molecular weight measurements made by GPC. The effect of different solvent fractions and initiator concentrations on the diffusion limitations were investigated. Only two kinetic parameters, kpd0 and ktd0 were obtained by fitting the kinetic model onto measured conversions for various reaction conditions at 0.2, 0.5 and 0.8 solvent fractions. Thus obtained kpd0 and ktd0 kinetic parameters were extrapolated to zero solvent fractions and from obtained values of kinetic parameters the conversion points for bulk DAT polymerization were calculated and compared to measured conversion points.

Predicting overall survival (OS) and overall response (OR) following durvalumab treatment in patients with multiple cancer types using a hybrid modeling strategy.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e15161-e15161
Author(s):  
Ting Chen ◽  
Yanan Zheng ◽  
Lorin Roskos ◽  
Donald E Mager
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Rate Constant ◽  
Tumor Size ◽  
Hybrid Modeling ◽  
Tumor Growth Rate ◽  
Growth Rate Constant ◽  
Model Parameters ◽  
Cancer Types ◽  
Modeling Strategy

e15161 Background: This study aimed to predict OS/OR and identify key predictors in patients with diverse cancer types treated with durvalumab, a PD-L1 targeting monoclonal antibody, using a hybrid modeling strategy that combines population pharmacodynamic (PD) modeling and machine learning (ML) algorithms. Methods: Individual longitudinal tumor size measurements and OS/OR data were available for 855 patients who received durvalumab therapy (10 mg/kg Q2W or 20 mg/kg Q4W; NCT01693562). Nine cancer types included non-small cell lung cancer (NSCLC), bladder cancer (BC), microsatellite instability-high (MSI-H) cancer, hepatocellular carcinoma (HCC), squamous cell carcinoma of the head and neck (SCCHN), gastroesophageal cancer (GEC), ovarian cancer (OC), pancreatic adenocarcinoma (PDAC) and triple-negative breast cancer (TNBC). A tumor kinetic model was developed to characterize diverse temporal profiles using a population-based modeling approach. Individual estimated tumor kinetic model parameters and patient demographic/physiological factors were used as inputs for predicting OS/OR using several ML approaches. Results: The final tumor kinetic model with liver metastasis (LM), neutrophil/lymphocyte ratio (NLR), tumor size at baseline (TBSL) and cancer types as covariates characterized the temporal tumor size data well. HCC and MSI-H cancer have the slowest tumor growth rate constant (kg), while GEC, SCCHN and TNBC have the fastest kg. BC, NSCLC and OC have the highest tumor killing rate constant. The most important predictors of OS identified by ML approach were tumor kinetic parameters (kg, fraction of drug-sensitive cells, time-delay in immune response), along with baseline disease factors, including hemoglobin (HGBBL), albumin (ALB), and NLR. Decision tree-based algorithms showed the best performance in predicting OR with accuracy above 90%. In addition to tumor kinetic parameters, PD-L1 expression on tumor cells (TC) and ALB were the most important predictors of OR. Conclusions: A combined population PD/ML approach showed good predictions of OS/OR in patients with different cancer types treated with durvalumab. LM, NLR,TBSL and cancer types were found to be important factors for tumor kinetics. In addition to tumor kinetic parameters, HGBBL, ALB, and NLR were found to be important predictors of OS, and TC and ALB were found to be important predictors of OR. These findings could provide a guidance on patient selection in future clinical trials.

Second-Order Kinetic Model for the Sorption of Cu(II) Ions in Aqueous Solutions of Zeolite NaA

2012 ◽  
Vol 560-561 ◽  
pp. 1174-1177 ◽  
Author(s):  
Dimitar Petrov Georgiev ◽  
Bogdan Iliev Bogdanov ◽  
Yancho Hristov ◽  
Irena Markovska
Keyword(s):  
Kinetic Model ◽  
Aqueous Solutions ◽  
Kinetic Parameters ◽  
Linear Equations ◽  
Linear Method ◽  
Second Order ◽  
Order Kinetic ◽  
Zeolite Naa ◽  
Order Kinetic Model ◽  
Pseudo Second Order

In this study, the sorption of Cu(II) ions in aqueous solutions of Zeolite NaA by performing batch kinetic sorption experiments. The equilibrium kinetic data were analyzed using the pseudo-second-order kinetic model. A comparison was made of the linear least-squares method and nonlinear method of the widely used pseudo-second-order kinetic model for the sorption of Cu(II) ions of Zeolite . Four pseudo-second-order kinetic linear equations are discussed. Kinetic parameters obtained from the four kinetic linear equations using the linear method differed but they were the same when using the non-linear method. Kinetic parameters obtained from four kinetic linear equations using the linear method differed. Equation type 1 pseudo-second-order kinetic model very well represented the kinetic of the adsorption Cu(II) ions by Zeolite NaA. Equation type 4 exhibited the worst fit. Present investigation showed that the non-linear method may be a better way to determine the kinetic parameters.

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