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1

Rola grawitacji w ewolucji pola stężeń roztworów elektrolitów w układzie membranowym

Ślęzak Andrzej, Bajdur Wioletta M.

Przemysł Chemiczny

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2019

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T. 98, nr 12

1952--1955

PL

Zbadano wpływ stężenia poszczególnych składników roztworów oraz konfiguracji układu membranowego na wartość objętościowych strumieni osmotycznych (Jr vi) w układzie jednomembranowym, w którym membrana polimerowa usytuowana w płaszczyźnie horyzontalnej rozdziela wodę i roztwór składający się z wody, etanolu i/lub CuSO4. Na podstawie otrzymanych wyników pomiarów obliczono współczynnik asymetrii (ki) oraz współczynnik osmotycznej polaryzacji stężeniowej (ζ r i ). Współczynnik ζ r i , poprzez grubość stężeniowej warstwy granicznej (δr i, związano ze stężeniową liczbą Rayleigha (Rr C), tj. parametrem sterującym przejściem ze stanu bezkonwekcyjnego do konwekcyjnego. Wykazano, że liczba ta pełni również funkcję przełącznika między stanami konwekcyjnym i bezkonwekcyjnym. Funkcjonowanie tego przełącznika świadczy o regulatorowej roli grawitacji ziemskiej w odniesieniu do transportu membranowego.

EN

Two cylindrical vessels connected with a horizontally placed membrane were used to det. the osmotic fluxes of aq. and aq.-alc. CuSO4 solns. at 295 K. The tested solns. and water were placed alternately in the upper or lower tank to det. an effect of gravitational acceleration on the osmotic fluxes. Location of the tested solns. in the upper cylinder resulted in an increase in osmotic flux compared to the inverse option. The asymmetry coeffs. of osmotic fluxes and concn. polarization as well as the values of Rayleigh nos. for both types of solns. were calcd.

2

Membrane Systems with Qualitative Evolution Rules

Kleijn J., Koutny M.

Fundamenta Informaticae

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2011

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Vol. 110, nr 1-4

217-230

EN

In membrane systems, biochemical reactions taking place in the compartments of a cell are abstracted to evolution rules that specify which and how many objects are consumed and produced. The recently proposed reaction systems also investigate processes carried by biochemical reactions, but the resulting computational model is remarkably different. A key difference is that in reaction systems, biochemical reactions are modeled using a qualitative rather than a quantitative approach. In this paper, we introduce so-called set membrane systems, a variant of membrane systems with qualitative evolution rules inspired by reaction systems. We then relate set membrane systems to Petri nets which leads to a new class of Petri nets: set-nets with localities. This Petri net model provides a faithful match with the operational semantics of set membrane systems.

3

Multiset-Based Self-Assembly of Graphs

Bernardini F., Brijder R., Rozenberg G., Zandron C.

Fundamenta Informaticae

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2007

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Vol. 75, nr 1-4

49-75

EN

We present a model for self-assembly of graphs based on multisets and the formalism of membrane systems. The model deals with aggregates of cells which are defined as undirected graphs where a multiset over a fixed alphabet is assigned to each vertex. The evolution of these aggregates is determined by an application of multiset-based aggregation rules to enlarge the current structure as well as an application of membrane-systems-based communication rules to enable cells to exchange objects alongside the edges of the graph. We compare the generative power of self-assembly membrane systems with and without communication rules, and we characterise properties of the sets of graphs generated by these systems. We also introduce two notions of stability for self-assembly processes that capture the idea of having produced a stable structure. Finally, we investigate self-assembly membrane systems where the alphabet is a singleton.

4

Dynamic Meaning Membrane Systems: An Application to the Description of Semantic Change

Bel-Enguix G., Jiménez-López M.D.

Fundamenta Informaticae

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2007

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Vol. 76, nr 3

219-237

EN

An application of membrane systems to natural languages study is presented. Specifically, we show how language change can be explained by using a new variant of membrane systems: Dynamic Meaning Membrane Systems (DMMS). By using DMMS, we model the main concepts of semantics and explain the three basic types of changes in meaning: broadening, narrowing and shift. Finally, we relate the membrane systems' application to language evolution with the suggested application of the so-called cultural grammar systems to the same topic. Collaboration between the two frameworks may provide a useful formalism that, due to its naturalness and simplicity, might offer interesting results in a discipline traditionally far away from any formalization.

5

Time and Synchronization in Membrane Systems

Cavaliere M., Sburlan D.

Fundamenta Informaticae

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2005

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Vol. 64, nr 1-4

65-77

EN

Membrane systems are parallel computational devices inspired from the cell functioning. Since the original definition, a standard feature of membrane systems is the fact that each rule of the system is executed in exactly one time-unit. However, this hypothesis seems not to have a counterpart in real world. In fact, in cells, chemical reactions might take different times to be executed. Therefore, a natural step is to associate to each rule of a membrane system a certain time of execution. We are interested in membrane systems, called time-free, working independently from the assigned execution time of the rules. A basic and interesting problem in time-free membrane systems consists in the synchronization of different rules, running in parallel, and having unknown execution times. Here, we present different ways to approach this problem within the framework of membrane systems. Several research proposals are also suggested.

6

Tree operations in P systems and [lambda]-calculus

Jonoska N., Margenstern M.

Fundamenta Informaticae

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2004

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Vol. 59, nr 1

67-90

EN

In this paper we introduce a membrane system (named lP systems) in which the computation is performed through certain operations on the tree structure of the membranes. The objects within the membranes play the role of catalysts for the operations. The result of the computation is the final configuration of the system. We show that lP systems can simulate pure l-calculus and so they have universal computational power. We also show that NP-complete problems can be solved in polynomial time in this way by showing that 3SAT is solvable in linear time with linear input.

7

Membrane Systems with Coupled Transport: Universality and Normal Forms

Martin-Vide C., Paun A., Paun G., Rozenberg G.

Fundamenta Informaticae

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2002

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Vol. 49, nr 1-3

1-15

EN

This paper continues research on membrane systems which function by communication only, meaning that there are no evolving rules for molecules. The whole computation process relies on passage of molecules through membranes - this provides communication between regions of the membrane system. Next to transport of single molecules through membranes (uniport) we also study a coupled transport of molecules, with two molecules passing either in the same direction (symport) or in opposite directions (antiport). We study the computational power of such membrane systems and prove that using only symport one gets Turing universality. Moreover, we prove that five membranes suffice to get Turing universality, and the number of membranes can be decreased to three if forbidding context conditions for transport are used.

8

DNA and Membrane Algorithms for SAT

Manca V.

Fundamenta Informaticae

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2002

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Vol. 49, nr 1-3

205-221

EN

Some DNA algorithms proposed in the literature for propositional satisfiability (SAT) are analyzed. In the class of `extract model' the two sub-classes of `literal string' and `clause string' algorithms are compared and a new formulation of these algorithms is given in terms of membrane systems. Then, the duality between literal string and clause string formulation of SAT is expressed by means of `singleton matrices' that introduce another membrane algorithm for SAT. The analysis developed suggests the perspective of membrane systems as problem-solving agents based on molecule localization, transformation, and propagation.

9

Evaluation of cation exchange membranes for pertraction processes

Szczepański P., Wódzki R.

Zeszyty Naukowe. Chemia / Politechnika Śląska

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2001

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z. 146

235-238

PL

Przedmiotem badań był wpływ fizykochemicznych właściwości kationowymiennych membran polimerowych (CEM) na pertrakcję kationów w wielomembranowym układzie hybrydowym (MHS). Układ składał się z sekwencji membran kationowymiennych z kwasowymi grupami sulfonowymi oraz membrany ciekłej (BLM): CEM-BLM-CEM. Membranę ciekłą stanowił roztwór kwasu di-(2-etyloheksylo) fosforowego w nafcie. Podstawą oceny membran były strumienie kationów Zn2+, Cu2+, Ca2+, Mg2+, K+, Na+ osiągane w procesie transportu konkurencyjnego.

10

Design of integrated membrane system with liquid and polymer membranes

Wódzki R., Szczepańska G.

Zeszyty Naukowe. Chemia / Politechnika Śląska

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2001

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z. 146

231-234

PL

Opracowano nowy zintegrowany układ membranowy DD-MHS[FLM-PV] wykorzystujący jednocześnie: proces dializy Donnana (DD), pertrakcji w układzie hybrydowym z przepływową membraną ciekłą (FLM) oraz perwaporacji wody akumulowanej w FLM. Działanie układu zintegrowanego porównano z działaniem jego poszczególnych składowych z osobna. Podstawą porównania były strumienie oraz współczynniki separacji takich kationów, jak: Zn2+, Cu2+, Ca2+, Mg2+, K+ oraz Na+.