Mathematical Modelling of Bioethanol Production from Raw Sugar Beet Cossettes in a Horizontal Rotating Tubular Bioreactor

Alternative to the use of fossil fuels are biofuels (e.g., bioethanol, biodiesel and biogas), which are more environmentally friendly and which can be produced from different renewable resources. In this investigation, bioethanol production from raw sugar beet cossettes (semi-solid substrate) by yeast Saccharomyces cerevisiae in a horizontal rotating tubular bioreactor (HRTB) was studied. Obtained results show that HRTB rotation mode (constant or interval) and rotation speed have considerable impact on the efficiency of bioethanol production in the HRTB. The main goal of this research was to develop a non-structural mathematical model of bioethanol production from raw sugar beet cossettes in the HRTB. The established mathematical model of bioethanol production in the HRTB describes substrate utilization and product formation (glycerol, ethanol and acetate) and presumes negative impact of high substrate concentration on the working microorganism (substrate inhibition) by using Andrews inhibition kinetics. All simulations of bioethanol production in the HRTB were performed by using Berkeley Madonna software, version 8.3.14 (Berkeley Madonna, Berkeley, CA, USA). The established non-structural bioprocess model describes relatively well the bioethanol production from raw sugar beet cossettes in the HRTB.

Kinetic modelling for concentration and toxicity changes during the oxidation of 4-chlorophenol by UV/H2O2

This work develops a kinetic model that allow to predict the water toxicity and the main degradation products concentration of aqueous solutions containing 4-chlorophenol oxidised by UV/H2O2. The kinetic model was developed grouping degradation products of similar toxicological nature: aromatics (hydroquinone, benzoquinone, 4-chlorocatechol and catechol), aliphatics (succinic, fumaric, maleic and malonic acids) and mineralised compounds (oxalic, acetic and formic acids). The degradation of each group versus time was described as a mathematical function of the rate constant of a second-order reaction involving the hydroxyl radical, the quantum yield of lump, the concentration of the hydroxyl radicals and the intensity of the emitted UV radiation. The photolytic and kinetic parameters characterising each lump were adjusted by experimental assays. The kinetic, mass balance and toxicity equations were solved using the Berkeley Madonna numerical calculation tool. Results showed that 4-chlorophenol would be completely removed during the first hour of the reaction, operating with oxidant molar ratios higher than R = 200 at pH 6.0 and UV = 24 W. Under these conditions, a decrease in the rate of total organic carbon (TOC) removal close to 50% from the initial value was observed. The solution colour, attributed to the presence of oxidation products as p-benzoquinone and hydroquinone, were oxidised to colourless species, that resulted in a decrease in the toxicity of the solutions (9.95 TU) and the aromaticity lost.

Assess transmissibility of different influenza subtypes: Based on a SEIABR model

Background: Influenza is a worldwide public health problem which causes a serious economic and health burden. In order to provide a scientific basis for improving the prevention and control level of influenza, using dynamic model to evaluate the infection rates of influenza different subtypes from 2010 to 2019 in China. Methods: This article established SEIABR model and calculated the infection rates of different influenza subtypes by using the Berkeley Madonna software. Results: The average infection rate of influenza was (7.95±1.27)×10-10 , and influenza A was (7.25±0.82) ×10-10, influenza B was (5.88±0.97)×10-10. In addition, the infection rates of A /H1N1, A/H3N2, B/Yamagata and B/Victoria were (7.25±0.82) ×10-10, (6.13±0.35) ×10-10, (6.01±0.52) ×10-10, (6.37±0.79) ×10-10. Conclusion: Between each year, flu transmission capacity had fluctuation. Influenza A was more transmissible than influenza B, and during the major subtypes, influenza A/H1N1 was the most transmissible.

Assessment of the prevention and control effects on the outbreak of COVID-19 in Hunan, China: Based on a SEIAR Dynamic Model

Background A new infectious disease, Coronavirus disease 2019 (COVID-19) has been first reported during December 2019 in Wuhan, China, cases have been exported to other cities and abroad rapidly. Hunan is the neighboring province of Wuhan, a series of preventive and control measures were taken to control the outbreak of COVID-19. It is critical to assess these measures on the epidemic progression for the benefit of global expectation.Method: A Susceptible-exposed-infections/asymptomatic-removed (SEIAR) model was established to evaluate the effect of preventive measures. Berkeley Madonna 8.3.18 was employed for the model simulation and prediction, and the curve-fitting problem was solved by Runge-Kutta fourth-order method.Results In this study, we found that Rt was 2.71 from January 21 to 27 and reduced to 0.21 after January 27, 2020. If measures have not been fully launched, patients in Hunan would reach the maximum (8.96 million) on March 25, 2020, and end in about 208 days; when measures have been fully launched, patients in Hunan would just reach the maximum (699) on February 9, 2020, and end in about 56 days, which was very closed to the actual situation.Conclusion The outbreak of COVID-19 in Hunan, China has been well controlled under current measures, full implementation of measures could reduce the peak value, short the time to peak and duration of the outbreak effectively, which could provide a reference for controlling of COVID-19 for other countries.

Stoichiometry and Kinetics of Sequential Dimethacrylate Enzymolysis

The increasing use of methacrylate-based materials in tissue engineering and dental restorations demands detailed evaluation of enzymolysis of these materials due to toxicity, durability, and biocompatibility concerns. The objective of this study is to develop tools for assessing and ranking the enzymolysis kinetics of dimethacrylate (DMA) compounds. Triethyleneglycol DMA and diurethane DMA are employed as model DMAs for kinetic studies of 2-step enzymolysis by 2 esterases, pseudocholine esterase and cholesterol esterase. In addition, the intermediate hydrolysis products, mono-methacrylates (mono-MAs), are prepared via esterases. The kinetics of DMA enzymolysis are evaluated per the concentrations of DMA. The enzymolysis products are quantified by high-performance liquid chromatography. Additionally, stoichiometric analysis and a Berkeley Madonna model are employed to compare the efficacy of esterases in DMA enzymolysis. The chemical structure of mono-MAs is verified by proton and heteronuclear single quantum coherence (2D 1H-13C) nuclear magnetic resonance spectroscopy and mass spectrometry. In evaluating the ratio of sequential and simultaneous degradations of DMA and mono-MA, the stoichiometric analysis draws the same conclusions without using [mono-MA] as the experimental observation using [mono-MA]. The majority of the 4 esterase-DMA combinations undergo the sequential enzyme-catalyzed hydrolysis, from DMA to mono-MA to diol. However, cholesterol esterase is more effective than pseudocholine esterase in maintaining sequential degradation until >90% of DMA is decomposed. Both enzymolysis steps are first-order reactions. The mono-MAs are more hydrolysis resistant than DMAs. Moreover, esterase efficacy and selectivity on DMA enzymolysis are presented. The stoichiometric analysis provides valuable tools in assessing DMA enzymolysis when mono-MA is difficult to be obtained. The resistance of mono-MAs to enzymolysis suggests a need for thorough toxicity evaluations of these intermediate compounds. It also advocates the alternative approaches in designing and developing durable and biocompatible materials.

687. Modeling the Impact of Introduction of Influenza Vaccination on ILI Cumulative Case Count in Cameroon

Background Influenza illness can range from mild to severe, with serious outcomes occurring in children and the elderly. Flu has been studied extensively in geographies where vaccine is often plentiful. The burden of influenza is not well known in tropical regions where vaccine coverage is scant. Our study examines the impact of introducing flu vaccination on cumulative incidence in a Cameroonian population with <0.2% influenza vaccine utilization Methods The data consists of 1 year of flu surveillance from patients presenting with influenza-like-illness at clinics in Cameroon. Samples underwent RT-PCR influenza screening. Analysis was performed in Berkeley Madonna. We developed ordinary differential equations (ODE)s under the SEIR compartmental model and calculated R0. We estimated the proportion of cases the clinics observed to make inferences to the catchment population of these health facilities. We developed another set of ODEs to introduce vaccination using a pulse function with a 50% efficacy and 45% vaccination coverage. Results We observed 82.9% reduction in flu cases by introducing vaccination at 45% coverage (US average). Cameroon would likely achieve reduced coverage. Therefore, we examined introducing vaccination with 10% coverage, and observed that flu cases were cut by over one third. Conclusion This analysis demonstrates that introducing vaccination in Cameroon clinics would reduce influenza cases substantially even with only a small proportion of the population vaccinated. Flu vaccination campaigns should be strongly considered as they can reduce case count which may reduce the likelihood of transmitting flu to those who are at risk the most severe outcomes. Disclosures All authors: No reported disclosures.