M-idempotent and self-dual morphological filters

In this paper, we present a comprehensive analysis of self-dual and m-idempotent operators. We refer to an operator as m-idempotent if it converges after m iterations. We focus on an important special case of the general theory of lattice morphology: spatially variant morphology, which captures the geometrical interpretation of spatially variant structuring elements. We demonstrate that every increasing self-dual morphological operator can be viewed as a morphological center. Necessary and sufficient conditions for the idempotence of morphological operators are characterized in terms of their kernel representation. We further extend our results to the representation of the kernel of m-idempotent morphological operators. We then rely on the conditions on the kernel representation derived and establish methods for the construction of m-idempotent and self-dual morphological operators. Finally, we illustrate the importance of the self-duality and m-idempotence properties by an application to speckle noise removal in radar images.     

Phenolic Composition,Essential Oil,and Antioxidant Activity in the Aerial Part of Artemisia Herba-Alba from Several Provenances: A Comparative Study

This study characterized the phenolic, aroma compositions, and antioxidant capacities of four Artemisia herba alba accessions collected from north and center regions in Tunisia in order to select valuable origin with optimal bioactive compounds production. The total polyphenol and flavonoid contents varied between accessions with maxima contents observed in center regions. Kaempherol, apigenin, naringenin, p-coumaric, trans-cinnamic, and caffeic acids were the most abundant compounds with percentage varying depending on the considered accession. Significant changes on essential oil yields (0.4–1.2%) were found between accessions and three different oil chemotypes were distinguished: camphor, fenchol/α-thujone, and α-thujone/camphor. Cluster analysis of volatile and phenolic compositions grouped the accessions on different groups. Antioxidant activities of extracts were found to be higher than essential oils for the four provenances. The results suggested that the center regions have high potential for selecting varieties rich on essential oil, antioxidant phenolic acids, and flavonoids.     

Chemical Composition and Antioxidant Activities of Tunisian Thymus capitatus L. Methanolic Extract

Thymus capitatus has traditionally been considered as an anthelmintic, antispasmodic, carminative, emmenagogue, expectorant, rubefactient, sedative, stimulant, and tonic. This work was carried out to determine total polyphenol and total flavonoids chemical composition of phenolics and to evaluate the antioxidant activities of the methanolic extract. Total phenolic contents were assayed using the Folin–Ciocalteu reagent, total flavonoid content was measured spectrophotometrically and phenolics were analyzed by reverse phase–high performance liquid chromatography. The 1,1-diphenyl-2-picrylhydrazyl and reducing power were calculated. Total phenols and total flavonoids varied significantly among the studied regions. Chromatographic analysis by reverse phase–high performance liquid chromatography showed that phenolic acids: tannic, gallic, chlorogenic hemihydrate, caffeic, syringic, ferulic, p-coumaric acid, and trans-cinnamic rosmarinic were the main compounds. The anti-radical activity was region-dependent and could be summarized as follows in ascending order: Boukornine > Kef > Bizerte > Grombelia. Reducing power in the four studied regions was stronger than positive control (ascorbic acid). From these results we have conclude that thyme methanolic extract may have a role in pharmaceutical preparations and preservatives as an antioxidant.     

No-wait scheduling of a two-machine flow-shop to minimise the makespan under non-availability constraints and different release dates

In this paper, we consider the two-machine no-wait flow-shop scheduling problem, when every machine is subject to one non-availability constraint and jobs have different release dates. The non-availability intervals of the machines overlap and they are known in advance. We aim to find a non-resumable schedule that minimises the makespan. We propose several lower bounds and upper bounds. These bounding procedures are used in a branch-and-bound algorithm. Computational experiments are carried out on a large set of instances and the obtained results show the effectiveness of our method.     

Protein Communication System: Evolution and Genomic Structure

We develop a mathematical model of the genetic information storage and transmission system and investigate its properties. Breaking with tradition, whereas the genetic information storage and transmission apparatus is conventionally modelled as an engineering communication system with the DNA sequence as the input and the amino acid chain as the output, in this paper the genetic communication model is viewed as one between proteins. A connection in a series of protein communication systems is equivalent to a channel through time: the Channel of Evolution. We investigate the dynamics of the channel of evolution in both cases of a constant and time-variant point mutation rates. We prove that the distribution of amino acids converges geometrically to a specific distribution which matches nearly perfectly an estimate of the natural abundance of amino acids in Nature today. Moreover, based on the highly redundant structure of the encoded genetic message (i.e., DNA), we demonstrate that the role of introns in eukaryotic genomes is to maintain a fine balance between two competing yet complementary forces: stability and adaptability. The stability role is evaluated by showing that introns play the role of a decoy in absorbing mutations. We derive the optimal exon length distribution, which minimizes the probability of error in eukaryotic genomes. Furthermore, to understand how Nature can physically achieve such a distribution, we propose a diffusive random walk model for exon generation throughout evolution. This model results in an alpha stable distribution, which is asymptotically equivalent to the optimal distribution. Experimental results on various eukaryotic organisms spanning the phylogenetic tree from unicellular organisms to plants to vertebrates show that both distributions accurately fit the biological data.     

Mass transfer measurements and modeling in a microchannel photocatalytic reactor

The main objective of this paper was to evaluate the influence of mass transfer on the photocatalytic efficiency at a low flow rate in the order of several mL per hour. Several continuous flow microchannel reactors have been used to study the degradation of salicylic acid (SA) taken as a model pollutant. The photocatalytic degradation of salicylic acid, under UV illumination of 1.5 mW cm⁻², was assessed from the outlet concentration measured by liquid chromatography HPLC. It was shown that the degradation of SA by UV was limited by mass transfer. Numerical simulations have allowed establishing a relationship of the Sherwood number valuable for all the microchannel geometries. Computational fluid dynamics with Comsol Multiphysics is useful for predicting the degradation yield for a given geometry of the microreactor. The best representation of the experimental data is obtained by introducing a kinetic law taking into account mass transfer limitation.     

A 3‐D numerical heat and mass transfer model for simulating the vibration effects on drying process

The high‐energy costs in the drying process highlight the employment of vibration which is a promising way to intensify this process. This work presents a three‐dimensional (3‐D) numerical version that exhibits the coupled heat and mass transfer phenomena posed by the external vibrating flow of hot air during the drying process. In order to simulate 3‐D vibrating drying, a 3‐D unstructured control volume finite element method is developed to analyze the heat and mass transfer during unsaturated porous media drying. Numerical simulation results, which depict the effects of the external vibrating flow which forces the drying process to occur more rapidly and intensively than ever before, are presented and analyzed.