Unveiling optimal operating conditions for an epoxy polymerization process using multi-objective evolutionary computation

The optimization of the epoxy polymerization process involves a number of conflicting objectives and more than twenty decision parameters. In this paper, the problem is treated truly as a multi-objective optimization problem and near-Pareto-optimal solutions corresponding to two and three objectives are found using the elitist non-dominated sorting GA or NSGA-II. Objectives, such as the number average molecular weight, polydispersity index and reaction time, are considered. The first two objectives are related to the properties of a polymer, whereas the third objective is related to productivity of the polymerization process. The decision variables are discrete addition quantities of various reactants e.g. the amount of addition for bisphenol-A (a monomer), sodium hydroxide and epichlorohydrin at different time steps, whereas the satisfaction of all species balance equations is treated as constraints. This study brings out a salient aspect of using an evolutionary approach to multi-objective problem solving. Important and useful patterns of addition of reactants are unveiled for different optimal trade-off solutions. The systematic approach of multi-stage optimization adopted here for finding optimal operating conditions for the epoxy polymerization process should further such studies on other chemical process and real-world optimization problems

Wild-Type and mutated laccases for a green industry

In the frame of white biotechnology, enzymes attract an enormous attention both for their potential and for the recent social and economical interest in green chemistry. Thanks to the improved knowledge of production biochemistry, fermentation processes, and recovery methods, an increasing number of enzymes can be affordably produced. The majority of currently used industrial enzymes are the hydrolytic ones, being used for the degradation of various natural substances. Also, various oxidative enzymes, primarily laccases are used in industries such as the starch, textile, detergent and baking industries, and they represent a second important group of enzymes. This project has been focused on the recombinant expression of the industrially attractive laccase POXA1b from Pleurotus ostreatus in Pichia pastoris and on exploiting its industrial application in order to substitute some chemical industrial processes with a better eco-friendly ones. An economical analysis of the recombinant POXA1b laccase production process, in terms of productivity and cost has been evaluated. Furthermore, computational analysis and site-specific mutagenesis of the POXA1b were performed to increase the enzymatic performances towards selected substrates. A POXA1b laccase immobilization process was optimized by statistic methods (Response Surface Methodology) in order to increment the operational stability of the enzyme in specific processes. Applications of the recombinant enzyme were then developed: (i) reduction of the phenol contents inside the fruit juices by immobilized laccase POXA1b; (ii) synthesis of a new eco-friendly dyes for the staining of different textile materials (nylon, cotton and wool) and (iii) synthesis of a new eco-friendly dye for proteins visualization on the polyacrilamide gels; (iv) cotton fiber functionalization with an anti-adhesive and anti-oxidant dye polymer

Applications of Monte Carlo Methods in Biology, Medicine and Other Fields of Science

This volume is an eclectic mix of applications of Monte Carlo methods in many fields of research should not be surprising, because of the ubiquitous use of these methods in many fields of human endeavor. In an attempt to focus attention on a manageable set of applications, the main thrust of this book is to emphasize applications of Monte Carlo simulation methods in biology and medicine

Proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress

Published proceedings of the 2018 Canadian Society for Mechanical Engineering (CSME) International Congress, hosted by York University, 27-30 May 2018

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

Exploring communication and collective behaviour between spatially organised inorganic protocell communities

A living system profoundly relies on mass, information and energy interactions through cell-cell and cell-environment networks. As a step towards understanding such interactions, it is beneficial to design and create bottom-up artificial living systems from non-living components, with a specific focus on synergistic interactivity between artificial cells (protocells) and their local environment. Although there are several routes for fabricating protocellular systems, we recognise key challenges associated with a) developing protocellular models with high levels of organisational tunability, b) achieving cell-environment bilateral communication, and c) realising autonomous self-assembly and regulation of protocell systems. The aim of this thesis is thus to review some matrix-based and matrix-free methods of inorganic protocell (colloidosome) 3D-spatial organisation, as judicious system designs capable of cell-cell and cell-environment communication, collective behaviours, and dynamic self-assembly, in close relation with local environments.The first experimental chapter details assembly of colloidosomes within hydrogel or coacervate-based matrices. A droplet microfluidic technique is employed as a novel method for encapsulating segregated colloidosome colonies within alginate hydrogel microspheres. The technique exploits high tunability for customisable size, ratio, microscale geometry, and 3D-patterning parameters. Benefiting from the versatility associated with such matrix-based systems, the second experimental chapter develops 3D-organised colloidosomes for collective signalling and emergent behaviours. Notably, spatially segregated colonies show proximity-mediated chemical communication with increased kinetics compared to analogous homogenous arrangements. This proximity-enhanced colloidosome signalling is exploited, alongside segregated ionic/covalent crosslinking transitions in the environment, to obtain simultaneous structural degradation and resilience of hydrogel hemispheres as a programmable mechanism for protocell ejection. Colloidosomes are also employed as simple signalling hotspots within coacervate-matrix systems. The final experimental chapter aims to re-imagine colloidosome organisation into a matrix-free system, capable of dynamic self-assembly and self-sorting via electrostatically-active membrane appendages. Alginate-coated and chitosan-coated colloidosomes are either co-assembled or self-sorted, in response to varied pH environments. Again, these systems are highly coordinated with their environment and as such, can be spatially pattered according to temporal pH changes through endogenous enzyme catalysis. Furthermore, a spatiotemporal effect on the rate of colloidosome communication in the presence of a hostile guest molecule is demonstrated. <br/

Non-covalent interactions in organotin(IV) derivatives of 5,7-ditertbutyl- and 5,7-diphenyl-1,2,4-triazolo[1,5-a]pyrimidine as recognition motifs in crystalline self- assembly and their in vitro antistaphylococcal activity

Non-covalent interactions are known to play a key role in biological compounds due to their stabilization of the tertiary and quaternary structure of proteins [1]. Ligands similar to purine rings, such as triazolo pyrimidine ones, are very versatile in their interactions with metals and can act as model systems for natural bio-inorganic compounds [2]. A considerable series (twelve novel compounds are reported) of 5,7-ditertbutyl-1,2,4-triazolo[1,5-a]pyrimidine (dbtp) and 5,7-diphenyl- 1,2,4-triazolo[1,5-a]pyrimidine (dptp) were synthesized and investigated by FT-IR and 119Sn M\uf6ssbauer in the solid state and by 1H and 13C NMR spectroscopy, in solution [3]. The X-ray crystal and molecular structures of Et2SnCl2(dbtp)2 and Ph2SnCl2(EtOH)2(dptp)2 were described, in this latter pyrimidine molecules are not directly bound to the metal center but strictly H-bonded, through N(3), to the -OH group of the ethanol moieties. The network of hydrogen bonding and aromatic interactions involving pyrimidine and phenyl rings in both complexes drives their self-assembly. Noncovalent interactions involving aromatic rings are key processes in both chemical and biological recognition, contributing to overall complex stability and forming recognition motifs. It is noteworthy that in Ph2SnCl2(EtOH)2(dptp)2 \u3c0\u2013\u3c0 stacking interactions between pairs of antiparallel triazolopyrimidine rings mimick basepair interactions physiologically occurring in DNA (Fig.1). M\uf6ssbauer spectra suggest for Et2SnCl2(dbtp)2 a distorted octahedral structure, with C-Sn-C bond angles lower than 180\ub0. The estimated angle for Et2SnCl2(dbtp)2 is virtually identical to that determined by X-ray diffraction. Ph2SnCl2(EtOH)2(dptp)2 is characterized by an essentially linear C-Sn-C fragment according to the X-ray all-trans structure. The compounds were screened for their in vitro antibacterial activity on a group of reference staphylococcal strains susceptible or resistant to methicillin and against two reference Gramnegative pathogens [4] . We tested the biological activity of all the specimen against a group of staphylococcal reference strains (S. aureus ATCC 25923, S. aureus ATCC 29213, methicillin resistant S. aureus 43866 and S. epidermidis RP62A) along with Gram-negative pathogens (P. aeruginosa ATCC9027 and E. coli ATCC25922). Ph2SnCl2(EtOH)2(dptp)2 showed good antibacterial activity with a MIC value of 5 \u3bcg mL-1 against S. aureus ATCC29213 and also resulted active against methicillin resistant S. epidermidis RP62A