Awakened oscillations in coupled consumer-resource pairs

The paper concerns two interacting consumer-resource pairs based on chemostat-like equations under the assumption that the dynamics of the resource is considerably slower than that of the consumer. The presence of two different time scales enables to carry out a fairly complete analysis of the problem. This is done by treating consumers and resources in the coupled system as fast-scale and slow-scale variables respectively and subsequently considering developments in phase planes of these variables, fast and slow, as if they are independent. When uncoupled, each pair has unique asymptotically stable steady state and no self-sustained oscillatory behavior (although damped oscillations about the equilibrium are admitted). When the consumer-resource pairs are weakly coupled through direct reciprocal inhibition of consumers, the whole system exhibits self-sustained relaxation oscillations with a period that can be significantly longer than intrinsic relaxation time of either pair. It is shown that the model equations adequately describe locally linked consumer-resource systems of quite different nature: living populations under interspecific interference competition and lasers coupled via their cavity losses.Comment: 31 pages, 8 figures 2 tables, 48 reference

Quotients of fake projective planes

Recently, Prasad and Yeung classified all possible fundamental groups of fake projective planes. According to their result, many fake projective planes admit a nontrivial group of automorphisms, and in that case it is isomorphic to \bbZ/3\bbZ, \bbZ/7\bbZ, $7:3$, or (\bbZ/3\bbZ)^2, where $7:3$ is the unique non-abelian group of order 21. Let $G$ be a group of automorphisms of a fake projective plane $X$. In this paper we classify all possible structures of the quotient surface $X/G$ and its minimal resolution.Comment: 16 pages, with minor change of the expositio

Gene expression for simulation of biological tissue

BioDynaMo is a biological processes simulator developed by an international community of researchers and software engineers working closely with neuroscientists. The authors have been working on gene expression, i.e. the process by which the heritable information in a gene - the sequence of DNA base pairs - is made into a functional gene product, such as protein or RNA. Typically, gene regulatory models employ either statistical or analytical approaches, being the former already well understood and broadly used. In this paper, we utilize analytical approaches representing the regulatory networks by means of differential equations, such as Euler and Runge-Kutta methods. The two solutions are implemented and have been submitted for inclusion in the BioDynaMo project and are compared for accuracy and performance

On M2M Micropayments : A Case Study of Electric Autonomous Vehicles

The proliferation of electric vehicles has spurred the research interest in technologies associated with it, for instance, batteries, and charging mechanisms. Moreover, the recent advancements in autonomous cars also encourage the enabling technologies to integrate and provide holistic applications. To this end, one key requirement for electric vehicles is to have an efficient, secure, and scalable infrastructure and framework for charging, billing, and auditing. However, the current manual charging systems for EVs may not be applicable to the autonomous cars that demand new, automatic, secure, efficient, and scalable billing and auditing mechanism. Owing to the distributed systems such as blockchain technology, in this paper, we propose a new charging and billing mechanism for electric vehicles that charge their batteries in a charging-on-the-move fashion. To meet the requirements of billing in electric vehicles, we leverage distributed ledger technology (DLT), a distributed peer-to-peer technology for micro-transactions. Our proof-of-concept implementation of the billing framework demonstrates the feasibility of such system in electric vehicles. It is also worth noting that the solution can easily be extended to the electric autonomous cars (EACs)

Catalytic transformation of oxygen containing compounds into valuables : effect of ceria redox properties

The focus of this thesis is the investigation of sustainable routes for the production of commercially valuable oxygen containing compounds through the application of ceria-based catalysts. The catalytic transformation of levulinic acid (to γ-valerolactone), CO2, methanol and nitrobenzene (to methyl-N-phenyl carbamate), 1butanol (to 1-butene) and 1,3-butanediol (to 3-buten-2-ol) have been examined. Taking the conversion of levulinic acid as a model system, it was established that the surface oxygen vacancies, formed during temperature programmed reduction of reducible oxides, activate levulinic acid for reaction. Process sustainability has been examined in terms of full hydrogen utilisation with 100% yield of the target γ-valerolactone under stoichiometric conditions over supported Au catalysts. The production of the carbamate directly from CO2 was initially optimised towards dimethyl carbonate formation as a reaction intermediate, where the highest reported rate has been achieved. It was shown that total surface area of CeO2 is not a determining parameter for catalytic performance, while a decrease in Ce3+ content upon calcination improves CO2 activation. Dehydration of 1-butanol/1,3-butanediol revealed the requirement for the strong Lewis acid sites on the surface of the catalyst to form an alkene. The results presented in this thesis demonstrate direct participation of the ceria in the catalytic dehydration and carboxylation reactions

The supply chain management role as an economic reform to overcome the problem of regional imbalances, in Republic of Tatarstan

Abstract— The aim of this paper is to investigate how supply chain integration affects company performance. The paper considers the supply chain role in economy and regional disproportions between regions and federal districts in the Russian Federation. In the course of the proposed economic reform (fiscal space), we discovered that within 5 years, the least developed municipal entities that are part of the subject of Russia - the Republic of Tatarstan - will be able to receive up to $ 200 thousand (US Dollars), which could become the foundation for the further socio-economic transformations in the territory, and also act as an instrument for the formation of a more favorable investment climate. These distribution effects, both across and within countries, are likely to affect trade policy, and consequently, the evolution of supply chains