Search results for "Mathematical modelling"
showing 10 items of 59 documents
Antibacterial drug release from a biphasic gel system: Mathematical modelling
2019
Bacterial infections represent an important drawback in the orthopaedic field, as they can develop either immediately after surgery procedures or after some years. Specifically, in case of implants, they are alleged to be troublesome as their elimination often compels a surgical removal of the infected implant. A possible solution strategy could involve a local coating of the implant by an antibacterial system, which requires to be easily applicable, biocompatible and able to provide the desired release kinetics for the selected antibacterial drug. Thus, this work focusses on a biphasic system made up by a thermo-reversible gel matrix (Poloxamer 407/water system) hosting a dispersed phase (…
Numerical Modelling of Room Thermal Comfort Conditions
2006
Particular heat transfer coefficients of building elements gives quantitative notion only about heat losses through this building element. Analysis of the overall heat balance and heat losses of complete building and study of particular contribution of building elements in overall balance allows one to figure out the state of the building and find the building elements of bounding construction with most significant heat losses. Project variants of the buildings (or rebuilding in case of renovation), which ensure the desirable economy of energy and proportions of investments can be find varying the proportions of the surface area of building elements (e.g., windows and doors). A lot of facto…
APPLICATION OF MATHEMATICAL MODELS FOR THE SIMULATION OF THERMAL COMFORT CONDITIONS IN A LIVING ROOM
2005
The paper deals with the distributions of temperature and averaged turbulent airflows in living rooms in 2D and 3D approximations using Ansys/Flotran and Ansys/CFX software respectively. The distributions are calculated depending on the placement and temperature of heaters, heat transfer coefficients of the building structures and ventilation conditions. The authors analyse the influence of these factors on the air circulation and the related heat flows through building structures. The thermal balance of a room and its dependence on various external factors is also considered. As thermal comfort conditions’ parameters are analysed, the airflow velocities and indoor temperatures with its gra…
Greenhouse gas emissions and the links to plant performance in a fixed-film activated sludge membrane bioreactor - Pilot plant experimental evidence
2017
The present study explores the interlinkages among the operational variables of a University of Cape Town (UCT) Integrated Fixed Film Activated Sludge (IFAS) membrane bioreactor (MBR) pilot plant. Specifically, dedicated experimental tests were carried out with the final aim to find-out a constitutive relationship among operational costs (OCs), effluent quality index (EQI), effluent fines (EF). Greenhouse gas (GHG) emissions were also included in the study. Results showed that the EQI increases at low flow rate likely due to the dissolved oxygen (DO) limitation in the biological processes. Direct GHGs increase with the increasing of the air flow due to the anoxic N2O contribution. Irreversi…
A parsimonious dynamic model for river water quality assessment
2010
Water quality modelling is of crucial importance for the assessment of physical, chemical, and biological changes in water bodies. Mathematical approaches to water modelling have become more prevalent over recent years. Different model types ranging from detailed physical models to simplified conceptual models are available. Actually, a possible middle ground between detailed and simplified models may be parsimonious models that represent the simplest approach that fits the application. The appropriate modelling approach depends on the research goal as well as on data available for correct model application. When there is inadequate data, it is mandatory to focus on a simple river water qua…
An integral approach to sludge handling in a WWTP operated for EBPR aiming phosphorus recovery: simulation of alternatives, LCA and LCC analyses
2020
[EN] As phosphorus is a non-renewable resource mainly used to produce fertilizers and helps to provide food all over the world, the proper management of its reserves is a global concern since it is expected to become scarcer in the near future. In this work we assessed two different sludge line configurations aiming for P extraction and recovery before anaerobic digestion and compared them with the classical configuration. This study has been performed by simulation with the model BNRM2 integrated in the software package DESASS 7.1. Configuration 1 was based on the production of a PO4-enriched stream from sludge via elutriation in the primary thickeners, while Configuration 2 was based on t…
Wastewater modification processes assessment in a stabilization reservoir.
2008
A semi-empirical mechanistic model able to simulate the dynamics of a stabilization reservoir was developed incorporating both settling of particulate components and chemical/biological processes. Several factors affecting the reservoir effluent quality were taken into account: hydraulics and hydrology, solar radiation, atmospheric reaeration, algae, zooplankton, organic matter, pathogen bacteria, and sediment-water interaction. The model quantifies the specific influence of each factor on effluent quality, evaluating the correlation between the different considered factors. State variables included in the model were: algae, dissolved oxygen, organic matter, zooplankton and indicator bacter…
A new plant wide modelling approach for the reduction of greenhouse Gas emission from wastewater treatment plants
2017
Recent studies about greenhouse gas (GHG) emissions show that sewer collection systems and wastewater treatment plants (WWTPs) are anthropogenic GHG potential sources. Therefore, they contribute to the climate change and air pollution. This increasing interest towards climate change has led to the development of new tools for WWTP design and management. This paper presents the first results of a research project aiming at setting-up an innovative mathematical model platform for the design and management of WWTPs. More specifically, the study presents the project’s strategy aimed at setting-up a plant-wide mathematical model which can be used as a tool for reducing/controlling GHG from WWTP.…
Sustainable development of apple snack formulated with blueberry juice and trehalose
2021
Novel products that carry concrete and relevant health benefits, with texture and flavor not substantially different from already available products, are generally well accepted by consumers. Vacuum impregnation is a non-thermal technology that allows the enrichment of fruit with different ingredients in solution. The characteristic of the resulting product is a combination of both the solid matrix and the impregnation solution. This work aimed at: (i) evaluating the effect of trehalose on anthocyanin retention after drying of apple snacks vacuum impregnated with blueberry juice
A heuristic model-based approach for compensating wind effects in ski jumping.
2021
Wind influences the jump length in ski jumping, which raises questions about the fairness. To counteract the wind problem, the International Ski Federation has introduced a wind compensation system in 2009: time-averaged wind velocity components tangential to the landing slope are obtained from several sites along the landing slope, and these data are used in a linear statistical model for estimating the jump length effect of wind. This is considered in the total score of the ski jump. However, it has been shown that the jump length effect estimates can be inaccurate and misleading. The present manuscript introduces an alternative mathematical wind compensation approach that is based on an …