Implementing Local Search with Membrane Computing

Local search is currently one of the most used methods for finding solution in real-life problems. In this paper we present an implementation of local search with Membrane Computing techniques applied to the N-queens problem as a case study. A CLIPS program inspired in the Membrane Computing design has been implemented and several experiments have been performed.Ministerio de Ciencia e Innovación TIN-2009-13192Junta de Andalucía P08-TIC-0420

On Distributed Solution to SAT by Membrane Computing

Tissue P systems with evolutional communication rules and cell division (TPec, for short) are a class of bio-inspired parallel computational models, which can solve NP-complete problems in a feasible time. In this work, a variant of TPec, called $k$-distributed tissue P systems with evolutional communication and cell division ($k\text{-}\Delta_{TP_{ec}}$, for short) is proposed. A uniform solution to the SAT problem by $k\text{-}\Delta_{TP_{ec}}$ under balanced fixed-partition is presented. The solution provides not only the precise satisfying truth assignments for all Boolean formulas, but also a precise amount of possible such satisfying truth assignments. It is shown that the communication resource for one-way and two-way uniform $k$-P protocols are increased with respect to $k$; while a single communication is shown to be possible for bi-directional uniform $k$-P protocols for any $k$. We further show that if the number of clauses is at least equal to the square of the number of variables of the given boolean formula, then $k\text{-}\Delta_{TP_{ec}}$ for solving the SAT problem are more efficient than TPec as show in \cite{bosheng2017}; if the number of clauses is equal to the number of variables, then $k\text{-}\Delta_{TP_{ec}}$ for solving the SAT problem work no much faster than TPec

Membrane Based intensification of ammonia removal from wastewater

The aim of this research was to study a novel membrane based oxygen intensification system to enhance a biological wastewater treatment process for ammonia removal. Specifically, this work is concerned with the biological nitrification process which occurs in ion exchange packed columns during ammonia removal from wastewater. Two types of commercial clinoptilolite were used, namely KMI and BIT, as ion exchangers. Removal of ammonium ion by ion exchange offers a number of advantages such as the capability to handle shock loadings and to purify wastewater to a very high specification. Also, ion exchangers can be used to provide a solid surface for bacterial growth which enhances performance. The uptake removal rates of ammonium ions onto KMI and BIT clinoptilolite using DI water, RO water, and filtered tap water were examined. The presence of major metal ions that normally exist in wastewater such as K+, Ca++, and Mg++ and their impact on ammonia adsorption was tested. The experimental data were fitted using Langmuir and Freundlich isotherms and compared to related works done previously. KMI clinoptilolite exhibited the highest uptake capacity, and KMI clinoptilolite preference for the metal ions was found to be in the order Mg++¡ÖK+Ca++. The kinetics of the ammonium ion removal were studied at bench scale using KMI and BIT clinoptilolite. The process variables include: initial ammonia concentration, amount of clinoptilolite in contact with the solution, clinoptilolite particle size, and mixing speed. To model the kinetics removal rates two types of diffusion was assumed to be possible rate limiting steps, namely the external film diffusion and the intraparticle diffusion. Two models were selected to fit the controlled diffusion resistances, Furusawa-Smith to model the external film resistance and McKay model to model the intraparticle film resistance. The values of the external and internal mass transfer coefficients were calculated and tabulated. Five air permeable membranes were used, four porous membranes and a dense membrane. The porous membranes were Polyethersulfone (PES), Polytetrafluoroethylene (PTFE), Polypropylene (PP), and Nylon. The dense membrane was a silicon tube membrane. All membranes were assessed for aeration. The overall mass transfer coefficients were calculated using the two-film theory model. The highest oxygen transfer rate was observed in PTFE membrane, and in the following order of lower performance PP PES Nylon silicon tube. For the column studies, different loading rates were used, 0.96, 0.25, and 0.03 Kg N/(m3day) depending on the type of the experiment. For the bacteria-free silicon membrane column, the inlet ammonia concentration, bed height, and inlet flowrate were examined. Biologically activated silicon membrane column exhibited no difference in the ammonia removal comparing to bacteria-free column under the same operating conditions. The porous membrane columns were designed to enhance the aeration for the combined biologically active ion exchanger packed bed column. It was found that the porous membrane columns were significantly enhanced by introducing the nitrifying bacteria into the columns. For example, the uptake capacity of PP membrane column was increased from 0.43 to 0.67 meq/g by introducing the biological material into the PP column. The breakthrough bed volumes (BVs) were estimated and the uptake column capacities were calculated for all the used columns. The breakthrough curves were modeled using the Bohart-Adams and Thomas models. To assess the bio-regeneration as an alternative to the chemical regeneration, nitrifying bacteria circulated in PP and PES columns to treat exhausted KMI clinoptilolite. The results showed that some regeneration may be achieved, but complete regeneration would require higher concentrations of biomass which is recommended for future study

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 145

This bibliography lists 301 reports, articles, and other documents introduced into the NASA scientific and technical information system in August 1975

52nd Rocky Mountain Conference on Analytical Chemistry

Final program, abstracts, and information about the 52nd annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Snowmass, Colorado, August 1-5, 2010

Insights from Animal Reproduction

The chapters in this volume of "Insights from Animal Reproduction" address several, particular hot topics in the field of reproduction. The book begins with a comprehensive overview of the cryopreservation of sheep-produced embryos. The following chapter revises the assisted reproductive techniques available for South American wild mammals. Chapter 3 presents the technical procedures necessary to produce transgenic goats. Chapter 4 provides a comprehensive revision of the major molecular determinants of litter size in prolific species. Chapter 5 examines the germ cell determinant transmission, segregation, and function using the zebrafish as a model for germ cell specification in the embryo. Chapter 6 summarizes the current understanding of the molecular and cellular mechanisms regulating the early stages of folliculogenesis. Chapter 7 examines the sperm motility regulatory proteins as a tool to enhance sperm quality in cryopreservation processes. Chapter 8 discusses contemporary knowledge on the effects of extremely low frequency magnetic fields (ELF-MF) on male reproductive function in rodents. Chapter 9 highlights the importance of the cytogenetic evaluation in searching for causes of infertility of phenotypically normal animals, as well as individuals with an abnormal sex development. The last chapter provides evidence that other uterine diseases may be hidden behind the clinical diagnosis of pyometra that in some case may have a poor outcome