A Simple Membrane Computing Method for Simulating Bio-Chemical Reactions

There are two formalisms for simulating spatially homogeneous chemical system; the deterministic approach, usually based on differential equations (reaction rate equations) and the stochastic approach which is based on a single differential-difference equation (the master equation). The stochastic approach has a firmer physical basis than the deterministic approach, but the master equation is often mathematically intractable. Thus, a method was proposed to make exact numerical calculations within the framework of the stochastic formulation without having to deal with the master equation directly. However, its drawback remains in great amount of computer time that is often required to simulate a desired amount of system time. A novel method that we propose is Deterministic Abstract Rewriting System on Multisets (DARMS), which is a deterministic approach based on an approximate procedure of an exact stochastic method. DARMS can produce significant gains in simulation speed with acceptable losses in accuracy. DARMS is a class of P Systems in which reaction rules are applied in parallel and deterministically. The feasibility and utility of DARMS are demonstrated by applying it to the Oregonator, which is a well-known model of the Belousov-Zhabotinskii (BZ) reaction. We also consider 1-dimensional and 2-dimensional cellular automata composed of DARMS and confirm that it can exhibit typical pattern formations of the BZ reaction. Since DARMS is a deterministic approach, it ignores the inherent fluctuations and correlations in chemical reactions; they are not so significant in spatially homogeneous chemical reactions but significant in bio-chemical systems. Thus, we also propose a stochastic approach, Stochastic ARMS (SARMS); SARMS is not an exact stochastic approach, but an approximate procedure of the exact stochastic method

Designing a Residence in Sweden

The project was to design a home for the Nordstroms, a family who lived in Sweden. The challenge was to design a home for the family of four with a maximum square footage of 1100 square feet using the codes and space allocations required for another country. Meeting the needs of the client required much research. RESEARCH included studying the regional climate, the municipal building codes, and city regulations. Thorough research of building construction framing methods, insulation types and installation methods, site planning, materials and finishes were also essential for completing the project

Suppressing the effect of lithium dendritic growth by the addition of magnesium bis(trifluoromethanesulfonyl)amide

Practical applications of Li-S and Li-air batteries require the morphology of the Li metal negative electrode during charge/discharge (i.e., Li-deposition/dissolution) cycling to be precisely controlled. Herein, we used magnesium bis(trifluoromethanesulfonyl)amide [Mg(TFSA)(2)] as an electrolyte additive to suppress the growth of Li dendrites, utilizing the occurrence of an alloying reaction between the initially substrate-deposited Mg and the subsequently deposited Li. Notably, no metallic Mg formation and no change in Li deposition morphology were observed at an electrolyte composition of 0.1 M Mg(TFSA)(2) + 0.9 M LiTFSA/triglyme, irrespective of the applied potential. In contrast, increasing the Mg salt concentration to 0.5 M resulted in the deposition of interconnected granules, reflecting a dramatic morphology improvement. X-ray diffraction analysis revealed the occurrence of the abovementioned alloying, which finally afforded a deposit composition of Li0.9Mg0.1 via the formation of an intermediate Li0.14Mg0.86 phase. Importantly, the deposits obtained under various applied potentials were relatively smooth, with no needle-like morphology observed.ArticlePHYSICAL CHEMISTRY CHEMICAL PHYSICS.20(2):1127-1133(2018)journal articl

Scattering of dislocated wavefronts by vertical vorticity and the Aharonov-Bohm effect II: Dispersive waves

Previous results on the scattering of surface waves by vertical vorticity on shallow water are generalized to the case of dispersive water waves. Dispersion effects are treated perturbatively around the shallow water limit, to first order in the ratio of depth to wavelength. The dislocation of the incident wavefront, analogous to the Aharonov-Bohm effect, is still observed. At short wavelengths the scattering is qualitatively similar to the nondispersive case. At moderate wavelengths, however, there are two markedly different scattering regimes according to wether the capillary length is smaller or larger than $\sqrt{3}$ times depth. The dislocation is characterized by a parameter that depends both on phase and group velocity. The validity range of the calculation is the same as in the shallow water case: wavelengths small compared to vortex radius, and low Mach number. The implications of these limitations are carefully considered.Comment: 30 pages, 11 figure