Photobioreactor Limnospira indica Growth Model: Application From the MELiSSA Plant Pilot Scale to ISS Flight Experiment

Bioregenerative life support systems (BLSS) are the foundation stone to self-sustainable manned space missions. The MELiSSA is a BLSS concept that has evolved through a mechanistic engineering approach designed to acquire both theoretical and technical knowledge on each subsystem independently and, therefore, produces the necessary knowledge and experience needed to co-integrate all the subsystems together with a high level of control. One of the subsystems is a photobioreactor colonized by an axenic culture of the cyanobacterium Limnospira indica PCC8005 for revitalizing the air for the crew. This subsystem was extensively studied, and a mass balanced mechanistic model was developed to describe, predict, and control the photobioreactor. The model was based on a light transfer limitation model coupled to a kinetic model for the cyanobacteria growth through a Linear Thermodynamics of Irreversible Processes (LTIP) approach, including substrate limitation. The model was integrated into several hydrodynamic models adapted to several photobioreactors design and experiments, from a 100 L airlift pilot scale ground photobioreactor to a 50 ml membrane photobioreactor for ISS flight. Through this article we detail the principles of this mechanistic model and their application to different photobioreactor scales for predictive and descriptive simulations.

ON QUADRATIC FORMS WITH A STATIONARY HYPERPLANE

A critical analysis (with specific numerical examples) of the conclusions following from Onsager’s theory in the classical linear thermodynamics of irreversible processes shown the insufficiency of conditions that guarantee the non-negativity and equality to zero of the entropy production. In order to understand the reasons for such a situation, the article introduces the concept of a quadratic form with a stationary hyperplane and compiles a system of nonlinear equations of a special form, in which a Boolean vector is unknown. Their precise definitions are given. The theorem is formulated and proved as a criterion, the fulfillment of the conditions of which is necessary and sufficient for a quadratic form to be a form with a stationary hyperplane. It is also shown that the quadratic form with a stationary hyperplane as applied to the production of the entropy gives quite correct explanations for the discrepancies that occur in Onsager’s theory. Instead, those explanations do not contradict the second law of thermodynamics. Thus, a quadratic form with a stationary hyperplane can be considered as a completely adequate mathematical model for studying a certain class of issues in the classical linear thermodynamics of irreversible processes. It is shown as well that every quadratic form with a stationary hyperplane is reducible to a perfect square and is a positive semidefinite form. So quadratic forms with a stationary hyperplane can be used in the educational process in the course of algebra when studying the topic “Quadratic forms”.

Resolution of Complex Issues in Genome Regulation and Cancer Requires Non-Linear and Network-Based Thermodynamics

The apparent lack of success in curing cancer that was evidenced in the last four decades of molecular medicine indicates the need for a global re-thinking both its nature and the biological approaches that we are taking in its solution. The reductionist, one gene/one protein method that has served us well until now, and that still dominates in biomedicine, requires complementation with a more systemic/holistic approach, to address the huge problem of cross-talk between more than 20,000 protein-coding genes, about 100,000 protein types, and the multiple layers of biological organization. In this perspective, the relationship between the chromatin network organization and gene expression regulation plays a fundamental role. The elucidation of such a relationship requires a non-linear thermodynamics approach to these biological systems. This change of perspective is a necessary step for developing successful ‘tumour-reversion’ therapeutic strategies.

Geochemical barriers as structural components of the geochemical systems evolution

The term “geochemical barrier” (GCB) has been widely used in the Russian geochemical literature as a key concept of the distribution of elements and substances theory (incl. pollutions)although in the world research practice this term is not particularly represented. The assessment of the functional role of the geochemical barriers in relation to the properties and evolution of the geochemical systems (GCS)is demonstrated.The foundations of Haken synergy, the foundations of self-organization of systems and non-equilibrium (non-linear) thermodynamics of I. Prigogine and his school are used as a methodological framework. From the authors’ point of view, GCB are considered as self-organizing components of GCS, in which physical and chemical processes are activated, leading to the transformation of atomic and molecular structures, chemical associations and individual chemical elements under the impact of active media (processes). They can be the defining phenomenon of the emergence and evolution of GCS. The concept of geochemical barriers is the foundation for technologies that are actively implemented for cleaning and protecting soils, groundwater and surface water, and the geological environment in general.

Towards a dual ontology: duality, a case study

The main aim of this work is to depict the interconnection of the most relvantformal concepts of modal logic and category theory, i.e., bisimulation andduality, arising from the mathematical analysis of physical processes and toshow their relevance with respect to some foundational issues related to the actual ontological debates. Current foundamental physics concerns the non-linear thermodynamics of the quantum eld, whose range is made of far from equilibrium systems and whose basic mechanism of symmetries (patterns) formation supposes the spontaneous breaking of symmetries (SBS). SBS implies that such systems reach unpredictable states. Thus, evolutive and/or far from equilibrium systems are to be conceived primarily as processes and just in a secondary way as objects, for the information they display is always incomplete with respect to their evolution. Formally, this is due to their non-linear mathematical behaviour.This make a question about the ontology of such systems, given thatthe actual most widespread ontologies conceive existent entities just as objects(actualist ontologies). It is claimed that the fundamental dierence and advantage of category theoretic approach to foundation is that, instead of considering objects and operations for what they 'are', as it is in set theory, in and through category theory we are considering them for what they 'do'. This, of course, would constitute a signicative shifting in mathematical philosophy and in foundationof mathematical physics: from a Platonic to an Aristotelian ontology ofmathematics (and, then, of physics). Actually, providing a contribution to thisvery shift is what this paper want to be focused on. In fact, the implicit pointthe present investigation is concerned with is how to treat the potential innite:the modalization of the existence of each object of the domain of quanticationmeans a potentially innite variation of the domain of quantication. The Aristotelian notion of potentiality diers with the usual one (employed by Platonism and/or formalism and/or conceptualism) inasmuch it does not presupposes any actuality. For instance, it is well known that the Platonic presupposition of set theory consists in the fact "that each potential innite, if it is rigorously applicable mathematically, presupposes an actual innite" [Hallett (1984, p. 25)]. In turn, the formalist notion of (absolute) completeness derives directly from that, if only for the actuality of the information a formal system was intended to dispaly.