scholarly journals The Prediction of CMDB Propellant lifetime Based on Arrhenius accelerated model, Berthelot’s equation and Multi-step Prout-Tompkins Model

2021 ◽  
Vol 2083 (3) ◽  
pp. 032018
Author(s):  
Qiong Wang ◽  
Yan Gu ◽  
Jiao Jiao Du ◽  
Lin Jia ◽  
Lin Jun Zhang
Keyword(s):  
Kinetic Model ◽  
General Model ◽  
Reaction Order ◽  
Accelerated Aging ◽  
Original Data ◽  
Lifetime Estimation ◽  
Vital Parameter ◽  
Safe Storage

Abstract Different models were provided to predict the storage lifetime of propellants more accurately. The stabilizer was recognized as a vital parameter for double based propellants’ storage lifetime estimation. The stabilizer contents of a certain RDX-CMDB propellant were traced during the accelerated aging tests. Based on that, the safe storage lifetime of this propellant were predicted using the Berthelot’s equation, Arrhenius accelerated equation and the advanced kinetic model, respectively. The predicted results were compared and the causes were analysed. It found that the biggest disadvantage of Berthelot’s equation and Arrhenius accelerated equation is that the predicted results are significantly affected by the original data. In details, the minor difference of original data will bring tremendous errors when extrapolating to normal temperature. The general model which can be used to depict complex reactions adopted in AKTS software was preferred compared to reaction order (RO) model and Prout-Tompkins (PT) model.

scholarly journals Physiological quality of soybean seeds stored after industrial treatments with different chemicals

2021 ◽  
Vol 10 (2) ◽  
pp. e6310212279
Author(s):  
Renata Cristiane Pereira ◽  
Lucas Caiubi Pereira ◽  
Alessandro Lucca Braccini ◽  
Larissa Vinis Correia ◽  
Murilo Fuentes Pelloso ◽  
...  
Keyword(s):  
Block Design ◽  
Accelerated Aging ◽  
Storage Period ◽  
Original Data ◽  
Soybean Seeds ◽  
Randomized Block Design ◽  
Seedling Length ◽  
Physiological Quality ◽  
Main Components

This study aimed to relate the smallest set of variables that compose the quality of soybean seeds lot under study, as well as to evaluate the influence of four industrial seed treatments and their respective slurry volumes on the physiological potential. The experiment was carried out in a completely randomized block design with 4 replicates and 24 treatments. The chemical treatments were: control (T1), micronutrient + polymer + drying powder (T2), bioregulator + polymer + drying powder (T3) and micronutrient + bioregulator + polymer + drying powder (T4). The seeds were stored for periods of 0, 15, 30, 45, 60 and 90 days and were subsequently evaluated for their physiological potential. In each storage period, the variable germination, first count, accelerated aging, emergence speed index, final emergence in the sand substrate, aerial part length, root length and total seedling length were evaluated. The main components of the standard germination test and first count were the ones that most contributed to explaining the variability of the original data. Increasing the volume of the slurry in the industrial seed treatment reduces the physiological quality of soybean seeds during storage.

scholarly journals Kinetic study on iso-concentration hydrogen peroxide bleaching of poplar chemi-thermomechanical pulp by the process of continuous chemical supplement

BioResources ◽  
2018 ◽  
Vol 13 (3) ◽  
pp. 5408-5415
Author(s):  
Xianqi Sun ◽  
Qingxi Hou ◽  
Haizhen Shi ◽  
Lichun Zhou
Keyword(s):  
Kinetic Model ◽  
Initial Phase ◽  
Reaction Rate ◽  
Reaction Order ◽  
Slow Phase ◽  
Thermomechanical Pulp ◽  
Bleaching Process ◽  
Peroxide Bleaching ◽  
Bleached Pulp ◽  
Continuous Chemical

In the authors’ previous studies, a bleaching process based on continuous chemical supplementation (CCS) was proposed to improve the effectiveness of peroxide bleaching of chemi-thermomechanical pulp (CTMP). In this study, the kinetic model of the CCS process of peroxide bleaching was applied to poplar CTMP to explore how the bleaching rate was affected. The model was based on the rate of chromophore elimination characterized by the brightness gains of bleached pulp. The reaction rate of chromophore destruction proceeded via a rapid initial phase followed by a slow phase. The equation of reaction rate was confirmed. The value of reaction order was -3.62, and the activation energy was 288.8 kJ/mol. The developed kinetic model was a good fit for the experimental results.

scholarly journals A Kernel Based Neighborhood Discriminant Submanifold Learning for Pattern Classification

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Xu Zhao
Keyword(s):  
Discriminant Analysis ◽  
Pattern Classification ◽  
General Model ◽  
Original Data ◽  
Face Database ◽  
Kernel Space ◽  
Criterion Function ◽  
Locality Preserving ◽  
Novel Method ◽  
Class Representation

We propose a novel method, called Kernel Neighborhood Discriminant Analysis (KNDA), which can be regarded as a supervised kernel extension of Locality Preserving Projection (LPP). KNDA nonlinearly maps the original data into a kernel space in which two graphs are constructed to depict the within-class submanifold and the between-class submanifold. Then a criterion function which minimizes the quotient between the within-class representation and the between-class representation of the submanifolds is designed to separate each submanifold constructed by each class. The real contribution of this paper is that we bring and extend the submanifold based algorithm to a general model and by some derivation a simple result is given by which we can classify a given object to a predefined class effectively. Experiments on the MNIST Handwritten Digits database, the Binary Alphadigits database, the ORL face database, the Extended Yale Face Database B, and a downloaded documents dataset demonstrate the effectiveness and robustness of the proposed method.

Mean-field study of the synergic effect of the CO–NO reaction on a heterogeneous substrate of interconnected sectors

2010 ◽  
Vol 88 (4) ◽  
pp. 383-392
Author(s):  
Joaquín Cortés ◽  
Eliana Valencia
Keyword(s):  
Field Theory ◽  
Activation Energy ◽  
Kinetic Model ◽  
Bimetallic Catalyst ◽  
Reaction Order ◽  
Mean Field Theory ◽  
Mean Field ◽  
Reduction Reaction ◽  
Synergic Effect ◽  
Heterogeneous Catalytic

A mean-field theory study is made of the behaviour of a kinetic model of the reduction reaction of NO by CO catalyzed by a surface with simple heterogeneity consisting of two interconnected sectors that differ in their NO dissociation activation energy. A synergistic effect is manifested in the activity, apparent activation energy, and reaction order of the system. This situation, analogous to that observed in the literature in the case of a heterogeneous catalytic particle, is used in the paper to analyze a real case of a bimetallic catalyst.

Stability of detonations for an idealized condensed-phase model

2008 ◽  
Vol 595 ◽  
pp. 45-82 ◽  
Author(s):  
M. SHORT ◽  
I. I. ANGUELOVA ◽  
T. D. ASLAM ◽  
J. B. BDZIL ◽  
A. K. HENRICK ◽  
...  
Keyword(s):  
Normal Mode ◽  
Condensed Phase ◽  
General Model ◽  
Reaction Rate ◽  
Reaction Order ◽  
Phase Model ◽  
Mode Analysis ◽  
Scaling Analysis ◽  
Neutral Stability ◽  
Two Dimensional

The stability of travelling wave Chapman–Jouguet and moderately overdriven detonations of Zeldovich–von Neumann–Döring type is formulated for a general system that incorporates the idealized gas and condensed-phase (liquid or solid) detonation models. The general model consists of a two-component mixture with a one-step irreversible reaction between reactant and product. The reaction rate has both temperature and pressure sensitivities and has a variable reaction order. The idealized condensed-phase model assumes a pressure-sensitive reaction rate, a constant-γ caloric equation of state for an ideal fluid, with the isentropic derivative γ=3, and invokes the strong shock limit. A linear stability analysis of the steady, planar, ZND detonation wave for the general model is conducted using a normal-mode approach. An asymptotic analysis of the eigenmode structure at the end of the reaction zone is conducted, and spatial boundedness (closure) conditions formally derived, whose precise form depends on the magnitude of the detonation overdrive and reaction order. A scaling analysis of the transonic flow region for Chapman–Jouguet detonations is also studied to illustrate the validity of the linearization for Chapman–Jouguet detonations. Neutral stability boundaries are calculated for the idealized condensed-phase model for one- and two-dimensional perturbations. Comparisons of the growth rates and frequencies predicted by the normal-mode analysis for an unstable detonation are made with a numerical solution of the reactive Euler equations. The numerical calculations are conducted using a new, high-order algorithm that employs a shock-fitting strategy, an approach that has significant advantages over standard shock-capturing methods for calculating unstable detonations. For the idealized condensed-phase model, nonlinear numerical solutions are also obtained to study the long-time behaviour of one- and two-dimensional unstable Chapman–Jouguet ZND waves.

A Finite Element Model for Oven Aged Tires

2005 ◽  
Vol 33 (2) ◽  
pp. 103-119 ◽  
Author(s):  
K. R. J. Ellwood ◽  
J. Baldwin ◽  
D. R. Bauer
Keyword(s):  
Finite Element ◽  
Kinetic Model ◽  
Mass Transport ◽  
Finite Element Model ◽  
Transport Properties ◽  
Oxygen Content ◽  
Crosslink Density ◽  
Accelerated Aging ◽  
Element Model ◽  
Derived Data

Abstract A finite element kinetic model has been developed to interpret issues related to accelerated aging of tires. The model is based on the Basic Autoxidation Scheme and incorporates mass transport limitations related to diffusion of oxygen into the layered elastomer system. The effect of aging on transport properties, such as diffusivity, due to changes in crosslink density is also considered in the model. The extent of oxidation is calculated at different locations within the tire as a function of time, temperature, and inflation media. The extent of oxidation predicted by the model is compared to experimentally derived data such as oxygen content, crosslink density, elongation-to-break, and modulus variation.

Sign in / Sign up

Export Citation Format

Share Document