Unit commitment-based load uncertainties based on improved particle swarm optimisation

This paper presents an intelligent method based on Improved Particle Swarm Optimisation to solve a unit commitment problem that takes into account the uncertainty in the demand. This uncertainty is included in the optimisation problem as a joint chance constraint that bounds the minimum value of the probability to jointly meet the deterministic power balance constraints. The demand is modelled as a multivariate, normally distributed, random variable and the correlation among different time periods is also considered. To demonstrate the effectiveness and robustness of the proposed algorithm, a system with 10 thermal and wind units with various conditions is simulated. The results and numerical experiments are compared with other methods to provide valuable information for both operational and planning problems.     

Morphology-dependent properties and swelling-induced transition in ‘sodium-alginate/urea’ thin films

The paper investigates the competing and morphology-dependent wetting and imbibition behaviours of ‘sodium-alginate/urea’ films that are currently used as thickeners in inkjet printing processes, dealing specifically with the structural changes of the coating within the swelled spot of the contacting (wetting) liquid drop. Depending on the initial morphology of the coating, the re-drying of the swelled wetting spot was found to lead to re-crystallization morphologies that are qualitatively different in both their texture and physicochemical properties. Well beyond the investigated ‘alginate/urea’ mixture, these results well highlight the critical influence that swelling-induced morphological re-constructions might have on interface phenomena in general, and in particular, on the wetting, impregnation and adhesion of solvent-processed polymeric assemblies.     

The Design of a Generic Intrusion-Tolerant Architecture for Web Servers

Nowadays, more and more information systems are connected to the Internet and offer Web interfaces to the general public or to a restricted set of users. Such openness makes them likely targets for intruders, and conventional protection techniques have been shown insufficient to prevent all intrusions in such open systems. This paper proposes a generic architecture to implement intrusion-tolerant Web servers. This architecture is based on redundancy and diversification principles, in order to increase the system resilience to attacks: usually, an attack targets a particular software, running on a particular platform, and fails on others. The architecture is composed of redundant proxies that mediate client requests to a redundant bank of diversified COTSfootnote{Commercial Off The Shelf.} application servers. The redundancy is deployed here to increase system availability and integrity. To improve performance, adaptive redundancy is applied: the redundancy level is selected according to the current alert level. The architecture can be used for static servers, i.e., for Web distribution of stable information (updated off-line), as well as for fully dynamic systems where information updates are executed immediately on an on-line database. The feasibility of this architecture has been demonstrated by implementing an example of a travel agency Web server.     

A review on zeolite imidazole frameworks: synthesis,properties, and applications

Journal of Porous Materials - Zeolitic imidazolate frameworks (ZIFs) consist of transition metal ions (Zinc or Cobalt) and imidazolate (Im) linkers in tetrahedral coordination surrounded by...     

Effect of finishing resins on mechanical and surface properties of cotton Denim fabrics

The effect of two famous finishing resins; acrylic resin (Resacryl M), and Glyoxal resin (Resinol AM), applied by the same Pad Dry Cure Process PDC but according to various conditions, on the mechanical and surface properties of different cotton denim fabrics is studied in this paper. The treated samples which are characterized at two steps of the treatment process: before and after washing (BW and AW) were characterized in terms of surface morphology observations by SEM, geometrical roughness measurements with Kawabata Evaluation System KES, thickness and Dry crease recovery angle DCRA measurements, and mechanical testing properties. It resulted that Resinol AM improves dry crease recovery angle, but causes a loss of strength in the warp direction. Nevertheless, Resacryl M improves handless and preserves the mechanical properties fabric before and after washing. Studying the effect of resins type, concentrations and curing temperature on the mechanical behavior and surface of the cotton fabrics is very important in textile laundering, because it allows choosing the best finishing agents and conditions. Furthermore, the results of this report will be in workable data to predict the properties of the treated fabrics after resin finishing.     

Antioxidant, antiacetylcholinesterase and antimicrobial activities of Cymbopogon schoenanthus L. Spreng (lemon grass) from Tunisia

Aqueous extract, proanthocyanidin rich extract, and organic extracts of Cymbopogon schoenanthus L. Spreng (lemon grass) shoots from three different locations in South Tunisia were screened for their antioxidant, acetylcholinesterase and antimicrobial activities. In addition to the evaluation of these activities, the contents of flavonoids and total phenolic compounds were determined.Antioxidant activity measured by DPPH assay showed that the proanthocyanidin extract exhibited higher antioxidant activity than the aqueous extract. Extract concentration providing 50% inhibition (IC₅₀) ranged from 16.4 ± 6.8 μg/mL to 26.4 ± 6.8 μg/mL. The antioxidant activity was also determined using the β-carotene/linoleic acid bleaching test. The best results (IC₅₀ = 0.11 ± 0.10 mg/mL) were obtained with the proanthocyanidin extract of the plants collected from the desert region (Dhibat).The greatest acetylcholinesterase inhibitory activity (IC₅₀ = 0.23 ± 0.04 mg/mL) was exhibited by the ethyl acetate and methanol extracts of the plants collected from the mountainous region. It seems that extracts obtained with more polar solvents gave better results.The proanthocyanidin extracts showed a good antimicrobial activity against Streptococcus sobrinus at low concentration (MIC = 4 mg/mL). Therefore, these extracts could be used to prevent carious lesions by inhibiting S. sobrinus growth.