scholarly journals Asphaltene Formation Damage Stimulation by Ultrasound: An Analytical Approach Using Bundle of Tubes Modeling

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Arash Rabbani ◽  
Mohammad Hossein Ghazanfari ◽  
Mahmood Amani
Keyword(s):  
Present Model ◽  
Formation Damage ◽  
Model Parameters ◽  
Surface Deposition ◽  
Novel Approach ◽  
Time Period ◽  
Proposed Model ◽  
Stimulation Efficiency ◽  
Permeability Impairment

This study presents a novel approach for bundle of tubes modeling of permeability impairment due to asphaltene-induced formation damage attenuated by ultrasound which has been rarely attended in the available literature. Model uses the changes of asphaltene particle size distribution (APSD) as a function of time due to ultrasound radiation, while considering surface deposition and pore throat plugging mechanisms. The proposed model predicts the experimental data of permeability reduction during coinjection of solvent and asphaltenic oil into core with reasonable agreement. Viscosity variation due to sonication of crude oil is used to determine the fluid mobility applied in the model. The results of modeling indicate that the fluid samples exposed to ultrasound may cause much less asphaltene-induced damage inside the porous medium. Sensitivity analysis of the model parameters showed that there is an optimum time period during which the best stimulation efficiency is observed. The results of this work can be helpful to better understand the role of ultrasound prohibition in dynamic behavior of asphaltene deposition in porous media. Furthermore, the present model could be potentially utilized for modeling of other time-dependent particle induced damages.

Description and validation of a harmonised model of the growing pig for the optimisation of the utilisation and excretion of nutrients

2002 ◽  
Vol 2002 ◽  
pp. 26-26
Author(s):  
D. M. Green ◽  
C. T. Whittemore
Keyword(s):  
Model Parameters ◽  
Main Stream ◽  
Biochemical Processes ◽  
Protein Retention ◽  
Dietary Nutrients ◽  
Growing Pig ◽  
Proposed Model ◽  
Ideal Protein ◽  
The Cost

The proposed model may be considered as an advance upon previous models; giving a synthesis of the contemporary information base and having a structure with maximum flexibility and minimum usage of fixed coefficients. It is distinctive in that it includes: (1) linkage from dietary nutrients to tissue retention via algorithms for main-stream biochemical processes; (2) a unified driver allowing compatible calculation of (i) the nutrient costs of energy and of protein cycling, (ii) the nutrient costs of maintenance and protein retention, and (iii) the interactions between energy and protein usage; (3) prediction of the rate and composition of tissue retention during growth, and of the cost of thermoregulation; (4) reversal of the role of conventional model parameters such that they become out-turns, rather than inputs, of the model, including (i) the metabolisability of energy, (ii) the ideality of protein and the efficiency of use of ileal digested ideal protein, (iii) the efficiency of utilisation of energy (k) for maintenance (kM), for protein (kPr) and lipid (kLr) retention, which are accepted as variables derived from calculation of efficiencies of production of ATP.

Modeling of Road Network Capacity Research in Urban Central Area

2010 ◽  
Vol 40-41 ◽  
pp. 778-784 ◽  
Author(s):  
Hong Chen ◽  
Ji Biao Zhou ◽  
Yao Wu ◽  
Hui Fang Zhu ◽  
Yan Yong Guo
Keyword(s):  
Ming Dynasty ◽  
Traffic Management ◽  
Road Network ◽  
Central Area ◽  
Network Capacity ◽  
Model Parameters ◽  
City Wall ◽  
Novel Approach ◽  
Proposed Model ◽  
Level Model

The analysis and modeling of road network capacity provides a useful measure for urban planning and traffic management. Therefore, the primary purpose of this research is to construct a novel approach of modeling the capacity of road network, based on the theory of space and time consumption. Based on the analysis of model parameters, a bi-level model is proposed to determine and optimize the capacity of road network Meanwhile, this paper elaborates on solution algorithm for its upper and lower level model. Taking the area of Ming Dynasty City Wall in Xi’an, China into account as a case study, the effectiveness of this proposed model is verified. The results presents that the model’s validity is verified. The results show that the main road network capacity in city wall of Ming Dynasty is 721883 pcu/d.

scholarly journals The role of oxygen intake and liver enzyme on the dynamics of damaged hepatocytes: Implications to ischaemic liver injury via a mathematical model

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0230833
Author(s):  
Aditi Ghosh ◽  
Claire Onsager ◽  
Andrew Mason ◽  
Leon Arriola ◽  
William Lee ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Liver Injury ◽  
Real Time ◽  
The Body ◽  
Model Parameters ◽  
Oxygen Intake ◽  
Serum Aminotransferase ◽  
Time Dynamics ◽  
Novel Approach

Ischaemic Hepatitis (IH) or Hypoxic Hepatitis (HH) also known as centrilobular liver cell necrosis is an acute liver injury characterized by a rapid increase in serum aminotransferase. The liver injury typically results from different underlying medical conditions such as cardiac failure, respiratory failure and septic shock in which the liver becomes damaged due to deprivation of either blood or oxygen. IH is a potentially lethal condition that is often preventable if diagnosed timely. The role of mechanisms that cause IH is often not well understood, making it difficult to diagnose or accurately quantify the patterns of related biomarkers. In most patients, currently, the only way to determine a case of IH is to rule out all other possible conditions for liver injuries. A better understanding of the liver’s response to IH is necessary to aid in its diagnosis, measurement, and improve outcomes. The goal of this study is to identify mechanisms that can alter associated biomarkers for reducing the density of damaged hepatocytes, and thus reduce the chances of IH. We develop a mathematical model capturing dynamics of hepatocytes in the liver through the rise and fall of associated liver enzymes aspartate transaminase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) related to the condition of IH. The model analysis provides a novel approach to predict the level of biomarkers given variations in the systemic oxygen in the body. Using IH patient data in the US, novel model parameters are described and then estimated for the first time to capture real-time dynamics of hepatocytes in the presence and absence of IH condition. The results may allow physicians to estimate the extent of liver damage in an IH patient based on their enzyme levels and receive faster treatment on a real-time basis.

A novel systematic product ideation model using technology trends

2020 ◽  
Vol 12 (3) ◽  
pp. 303-321
Author(s):  
Muhammad Ahmad Tauqeer ◽  
Knut Erik Bang
Keyword(s):  
Product Innovation ◽  
Product Life Cycle ◽  
Present Model ◽  
Idea Generation ◽  
Content Type ◽  
Product Innovations ◽  
Novel Approach ◽  
Proposed Model ◽  
Practical Implications ◽  
Technology Trends

Purpose This study aims to present a novel approach of using technology trends to trigger product ideas. It is primarily addressed to product ideation where limited applied approaches are available. Design/methodology/approach The model is built by extending the theoretical framework of ideation study. It comprises morphological analysis with product breakdown as primary and technological trends as a secondary dimension to prompt product ideas from user’s intuition. The approach is multidisciplinary using insights from the areas of cognition, management strategy and project management. The model is further tested in two different test configurations with university students (n = 81). Findings The results indicate that this systematic model can increase the quality and number of ideas generated by the students compared to generally practised approaches. It is shown that this approach increases the chances of triggering ideas. Research limitations/implications The testing of the present model is comprehensive and in no means exhaustive. Practical implications Because of the shrinking product life cycle, organisations have a need for systematic product ideation models that can assist in innovating their product ranges. It is important to study idea generation for products to not only assist product innovation but also comprehensively understand the process of creativity. The proposed model is primarily addressed to product innovation projects where limited practical tools are available for product ideation. The present model is easy to apply and has the tendency to generate novel product ideas that can lead to successful product innovations. Originality/value Product innovation currently has limited systematic ideation tools where this study contributes.

scholarly journals Two-step Homogenization of Poroelastic Properties of a Limestone

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Hung Truong Trieu ◽  
Nguyen NGOC BIEN ◽  
Pham DUC THO ◽  
Vu MINH NGOC ◽  
Do NGOC ANH ◽  
...  
Keyword(s):  
Transition Zone ◽  
Porous Matrix ◽  
Homogenization Method ◽  
Interfacial Transition Zone ◽  
Second Step ◽  
Model Parameters ◽  
Composite Sphere ◽  
Proposed Model ◽  
Self Consistent

This study aims at deriving the effective poroelastic properties of the oolitic limestones based on the Hashin composite sphere assemblage (CSA) micromechanical theory. The microstructure of oolitic limestones generally exhibits an assemblage of grains (oolites) surrounded by a matrix. Grain and matrix are linked via the interfacial transition zone (ITZ). Pores exist in these three material phases (oolite, ITZ and matrix). A two-step homogenization method is proposed. The first step consists of upscaling the properties of each porous phase (i.e. porous oolite, porous ITZ and porous matrix) in which each phase contains two sub-phases including pore and solid. The differential self-consistent scheme is used for the first step. At the second step, the three different porous constituents (oolite, ITZ and matrix) are assembled in a CSA model. A mathematical analogy between thermoelasticity and poroelasticity is used to obtain the effective poroelastic properties. A comparison between the proposed model and test data on the oolitic limestone from Bourgogne (France) helps to calibrate the model parameters and to highlight the role of ITZ phase.

Prospective Memory Development Across the Lifespan

2020 ◽  
Vol 25 (3) ◽  
pp. 162-173 ◽  
Author(s):  
Sascha Zuber ◽  
Matthias Kliegel
Keyword(s):  
Prospective Memory ◽  
Healthy Aging ◽  
Present Model ◽  
Current Knowledge ◽  
Well Being ◽  
The Elderly ◽  
Cognitive Factors ◽  
Everyday Functioning ◽  
Integrative Framework

Abstract. Prospective Memory (PM; i.e., the ability to remember to perform planned tasks) represents a key proxy of healthy aging, as it relates to older adults’ everyday functioning, autonomy, and personal well-being. The current review illustrates how PM performance develops across the lifespan and how multiple cognitive and non-cognitive factors influence this trajectory. Further, a new, integrative framework is presented, detailing how those processes interplay in retrieving and executing delayed intentions. Specifically, while most previous models have focused on memory processes, the present model focuses on the role of executive functioning in PM and its development across the lifespan. Finally, a practical outlook is presented, suggesting how the current knowledge can be applied in geriatrics and geropsychology to promote healthy aging by maintaining prospective abilities in the elderly.

In-Plane Flexible Ring Tire Model—Part 1: Modeling and Parameter Identification

2018 ◽  
Vol 46 (3) ◽  
pp. 174-219 ◽  
Author(s):  
Bin Li ◽  
Xiaobo Yang ◽  
James Yang ◽  
Yunqing Zhang ◽  
Zeyu Ma
Keyword(s):  
Static Load ◽  
Model Parameters ◽  
Tire Model ◽  
Test Results ◽  
Lumped Mass ◽  
Virtual Test ◽  
Proposed Model ◽  
Particle Swarm Method ◽  
Vehicle Dynamic Simulation ◽  
Flexible Ring

ABSTRACT The tire model is essential for accurate and efficient vehicle dynamic simulation. In this article, an in-plane flexible ring tire model is proposed, in which the tire is composed of a rigid rim, a number of discretized lumped mass belt points, and numerous massless tread blocks attached on the belt. One set of tire model parameters is identified by approaching the predicted results with ADAMS® FTire virtual test results for one particular cleat test through the particle swarm method using MATLAB®. Based on the identified parameters, the tire model is further validated by comparing the predicted results with FTire for the static load-deflection tests and other cleat tests. Finally, several important aspects regarding the proposed model are discussed.

Application of an Element-free Galerkin Method to Water Wave Propagation Problems

2014 ◽  
Vol 60 (1-4) ◽  
pp. 87-105 ◽  
Author(s):  
Ryszard Staroszczyk
Keyword(s):  
Wave Propagation ◽  
Galerkin Method ◽  
Present Model ◽  
Free Surface Elevation ◽  
Element Free Galerkin Method ◽  
Plane Flow ◽  
Element Free Galerkin ◽  
Proposed Model ◽  
Sloping Bed ◽  
Element Free

Abstract The paper is concerned with the problem of gravitational wave propagation in water of variable depth. The problem is solved numerically by applying an element-free Galerkin method. First, the proposed model is validated by comparing its predictions with experimental data for the plane flow in water of uniform depth. Then, as illustrations, results of numerical simulations performed for plane gravity waves propagating through a region with a sloping bed are presented. These results show the evolution of the free-surface elevation, displaying progressive steepening of the wave over the sloping bed, followed by its attenuation in a region of uniform depth. In addition, some of the results of the present model are compared with those obtained earlier by using the conventional finite element method.

EXPONENTIATED HALF-LOGISTIC LOMAX DISTRIBUTION WITH PROPERTIES AND APPLICATION

2019 ◽  
Vol XVI (2) ◽  
pp. 1-11
Author(s):  
Farrukh Jamal ◽  
Hesham Mohammed Reyad ◽  
Soha Othman Ahmed ◽  
Muhammad Akbar Ali Shah ◽  
Emrah Altun
Keyword(s):  
Real Data ◽  
Continuous Model ◽  
Model Parameters ◽  
Data Set ◽  
Lomax Distribution ◽  
Mathematical Properties ◽  
Proposed Model ◽  
Probability Weighted Moment ◽  
Record Statistics ◽  
Maximum Likelihood Criterion

A new three-parameter continuous model called the exponentiated half-logistic Lomax distribution is introduced in this paper. Basic mathematical properties for the proposed model were investigated which include raw and incomplete moments, skewness, kurtosis, generating functions, Rényi entropy, Lorenz, Bonferroni and Zenga curves, probability weighted moment, stress strength model, order statistics, and record statistics. The model parameters were estimated by using the maximum likelihood criterion and the behaviours of these estimates were examined by conducting a simulation study. The applicability of the new model is illustrated by applying it on a real data set.

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