Engineering Commons^™

Modelling And Fault Diagnosis Approach For Proton Exchange Membrane Fuel Cell Systems Incorporating Ambient Conditions, Saad Saleem Khan

Dissertations

Proton exchange membrane fuel cell (PEMFC), as a source of electrical power, provides numerous benefits such as zero carbon emission and high reliability as compared to wind and solar energy. PEMFC operates at very low temperature, high power density, and has very high durability as compared to other fuel cells. Being a non-linear power source with high sensitivity to ambient conditions variation, the prediction of PEMFC voltage and temperature is a complicated issue. The most common PEMFC models are classified as mechanistic models, semi-empirical models, and purely empirical methods. The mechanistic models are complex and require differential equations to predict …

Fib Model Code 2020 – Durability Design And Through Life Management Of New And Existing Structures, Frank Papworth, S Matthews

International Conference on Durability of Concrete Structures

Work has recently started in fib (Fédération Internationale du Béton) on the preparation of a new fib Model Code for Concrete Structures, under the working title of Model Code 2020 (MC2020). This will be a single code dealing with both new and existing concrete structures, that is both the design of new structures and all the activities associated with the assessment, interventions and the through-life management and care of existing concrete structures. Numerous goals relating to durability and service life design have been identified, including that ideally MC2020 should incorporate:

• Better models for deterioration processes addressing issues such as …

Activation Of Biochar From Olive Residues: A Predictive Model For Yield And Surface Area, Franco Berruti, Anastasia Colomba, Cedric Briens

Bio-Char II: Production, Characterization and Applications

A great amount of work in the literature is dedicated to the kinetic modelling of gasification reactions, while a limited number of authors have paid attention to the evolution of physical parameters, which are very important in the case in which the reaction is applied to the production of activated carbons. The Volume reaction model (VRM) [1], the Shrinking core model (SCM) [2], and the Random pore model (RPM) [3] are unable to provide a relationship between kinetics and the physical properties of the activated carbon and, particularly, between yield and surface area.

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Modelling In Vitro Dissolution And Release Of Sumatriptan Succinate From Polyvinylpyrrolidone-Based Microneedles Aided By Iontophoresis, James Paul Ronnander

Dissertations

A novel dissolving microneedle array system is developed to investigate permeation of a sumatriptan succinate formulations through the skin aided by iontophoresis. Three formulations consisting of hydrophilic, positively charged drug molecules encapsulated in a water-soluble biologically suitable polymer, polyvinylpyrrolidone (PVP), have been accepted by the U.S. Food and Drug Administration (FDA). The microneedle systems are fabricated with 600 pyramid-shaped needles, each 500 µm tall, on a 0.785-cm² circular array. In vitro transdermal studies with minipig skin and vertical Franz diffusion cells show > 68% permeation of sumatriptan over a 24-hour period. A combination of microneedle and electrical current density ranging …

Comparison Of Modelling Approaches For Development Of Discharge Rating Curves For Spillway/Bridge Combinations, Nathan Young

International Junior Researcher and Engineer Workshop on Hydraulic Structures

When estimating spillway discharge rating curves, engineers can use a variety of methods such as empirical equations, one- (1D) or two-dimensional (2D) hydraulic computer models, or a combination thereof; however, conservative assumptions are often applied to such methods. The use of three-dimensional (3D) computational fluid dynamics (CFD) models is an alternative modelling approach that can often better estimate spillway discharge rating curves, especially for complex flow situations. In this study, the results of 3D CFD models are compared to estimates of spillway discharge rating curves developed with a combination of empirical equations and other hydraulic computer models for spillway/bridge combinations. …

Challenges And Progresses Made On The Microkinetic Description Of Lignin Liquefaction: Application Of Group Contribution Methods, Manuel Garcia-Perez, Evan Terrell, Linda Broadbelt

Pyroliq 2019: Pyrolysis and Liquefaction of Biomass and Wastes

In this presentation a comprehensive microkinetic modelling framework and experimental tools are used to describe product yield and composition of direct lignin liquefaction processes with and without solvents (See Figure 1). With the framework proposed we aim to develop a unified theory and models capable of describing both dry (pyrolysis) and wet (hydrothermal and solvolysis) lignin liquefaction processes. An important phenomenon that has been shown to occur during lignin pyrolysis (as well as cellulose) is the formation of a liquid intermediate phase, and subsequent ejection of heavy products (>~250 Da) as aerosols from this intermediate. In our presentation we …

Optimization Of Processing Parameters Of Nanocomposite Film For Fresh Sliced Okra Packaging, Adeshina Fadeyibi Phd, Zinash Delebo Osunde Phd, Professor, Mohammed Gana Yisa Professor

Journal of Applied Packaging Research

Nanocomposite film can be regarded as an active packaging material which is capable of curtailing microbial growth and keeping food for an extended life. In this research, the optimum processing parameters of cassava starch-zinc nanocomposite film was determined for packaging fresh-sliced okra. Samples of the films, with thickness ranging between 15– 17µm, were developed from the blends of 24g of cassava starch, 0–2 % zinc nanoparticles (NP) and 45–55 % glycerol in 600 ml distilled water. The ideal film was determined by optimizing the film processing parameters using Box-Behnken Design in Surface Response Methodology. It was subsequently used to package …

Why Modeling Complex Dynamic Systems Using Fuzzy Cognitive Maps?, Peter P. Groumpos

International Journal of Business and Technology

The difficult problem of modeling Complex Dynamic Systems (CDS) is carefully reviewed. Main characteristics of CDS are considered and analyzed. Today’s mathematical models and approaches cannot provide satisfactory answers to the challenging problems of the society. The key problem of complex dynamic systems and control theory consists in the development of methods of qualitative analysis of the dynamics and behavior of such systems and in the construction of efficient control algorithms for their efficient operation. The purpose of control to bring the system to a point of its phase space which corresponds to maximal or minimal value of the chosen …

Natural Source Zone Depletion Of Lnapl: A Critical Review Supporting Modelling Approaches, Kaveh Sookhak Lari, Greg B. Davis, John L. Rayner, Trevor P. Bastow, Geoffrey J. Puzon

Research outputs 2014 to 2021

Natural source zone depletion (NSZD) of light non-aqueous phase liquids (LNAPLs) includes partitioning, transport and degradation of LNAPL components. NSZD is being considered as a site closure option during later stages of active remediation of LNAPL contaminated sites, and where LNAPL mass removal is limiting. To ensure NSZD meets compliance criteria and to design enhanced NSZD actions if required, residual risks posed by LNAPL and its long term behaviour require estimation. Prediction of long-term NSZD trends requires linking physicochemical partitioning and transport processes with bioprocesses at multiple scales within a modelling framework. Here we expand and build on the knowledge …

Consequence Modelling Of Co2 Pipeline Failure, Xiong Liu, Ajit R. Godbole, Cheng Lu, Guillaume Michal, Valerie M. Linton

Faculty of Engineering and Information Sciences - Papers: Part B

This paper describes the experimental investigation and Computational Fluid Dynamics (CFD) simulations of the dispersion of CO2 following high-pressure dense phase CO2 pipeline failure. A full-scale burst test was carried out to simulate a CO2 pipeline failure in the real world. The atmospheric dispersion of the CO2 following the explosive release was measured. The CFD models were validated against the experimental data. The models were then used to estimate the consequence distances related to CO2 dispersion following failure of pipelines with various diameters under different wind speeds. This approach provides a predictive formula for the consequence distances of CO2 transmission …

Improved Performance Of Ballasted Tracks At Transition Zones: A Review Of Experimental And Modelling Approaches, Buddhima Indraratna, Muhammad Babar Sajjad, Ngoc Trung Ngo, A Correia, Richard B. Kelly

Faculty of Engineering and Information Sciences - Papers: Part B

Track transitionssuch as bridge approaches, road crossings and shifts from slab track to ballasted track are common locations wheretrack degradation accelerates due to dynamic and high impact forces; as a consequence there is higher differential settlement. Thesetypes of discontinuities cause an abrupt change in the structural responseof the track due mainly tovariations in stiffness and track damping. Track transitionzones are prone to an accelerated deterioration of track material and geometrythat leads to increased maintenance costs.Track deteriorationalso leads to vehicle degradation due to enhanced acceleration, low frequency oscillation, and high frequency vibrations. While ballastdeterioration is amajor factor affecting thestability and longevity …