Comparative analysis of triacylglycerols from Olea europaea L. fruits using HPLC and MALDI‐TOFMS

MALDI‐TOFMS and HPLC are two analytical methods that were used to characterize triacylglycerols (TAG) of the Meski, Sayali, and Picholine Tunisian olive varieties. The HPLC chromatograms of the oils showed the presence of 15 TAG species, among which triolein (OOO) was the most abundant (21–48%). In the Sayali cultivar, OOO was the predominant TAG species followed by POO and LOO. However, the minor TAG molecules were represented by LnLO and LnLP. MALDI mass spectra produced sodiated ([M + Na]⁺) and potassiated ([M + K]⁺) TAG molecules; only the major TAG were potassiated [OOO + K] ([OOO + K]⁺, [POO + K]⁺, and [LOO + K]⁺). In contrast to the HPLC chromatograms, the MALDI mass spectra showed 13 peaks of TAG. The major peak was detected at m/z 907, which corresponds to OOO with an Na⁺ adduct. The results from both HPLC and MALDI techniques predict the fatty acid composition and their percentages for each olive variety. Practical applications: TAG are the main components in vegetable oils. These biomolecules determine the physical, chemical, and nutritional properties of the oils. The nutritional benefits of TAG are related to DAG (moderate plasma lipid level) and esterified FA, which are intermediate biosynthetic molecules of TAG. TAG analysis is necessary to discriminate between oils of different origin, since some oils have similar FA profiles. Olive products, oils, and table olives, are the main diet sources of TAG in the Mediterranean countries. In this work, chromatographic and spectrometric methods were used for TAG analysis and characterization of Tunisian olive varieties.     

Crack deviation during trimming of aluminium automotive sheets

Crack propagation and deviation during trimming of aluminium sheet metal have been analysed experimentally and modelled by a finite element analysis (FEA). The experimental results may be summarized as follows. Two crack propagation mechanisms operate in aluminium sheet metal, i.e. either between adjacent voids or by multiple coalescence of micro-cracks. A fracture process-zone may be identified for both mechanisms. Outside this fracture process-zone, no damage is observed. The particular crack propagation mechanism does not influence the crack path. A mechanical model based on a two steps analysis is presented. In the first step, the overall stress strain field prior to cracking is determined by an explicit Arbitrary Lagrangian Eulerian (ALE) formulation based FEA. In the second step, dedicated to crack propagation, no remeshing is used. A cumulative damage model based on the equivalent plastic strain increment is shown to be very efficient. The damage variable is interpreted as bifurcation in the direction of the maximum plastic strain rate. Finally, the applications show the possibility of trimming aluminium sheet metal without sliver generation.     

OS-CFAR and CMLD threshold optimization in distributed systems using evolutionary strategies

This paper proposes an improvement of the threshold optimization in distributed ordered statistics constant false alarm rate and censored mean level detector using Evolutionary Strategies (ESs). The target is assumed to be Rayleigh distributed and the observations are independent from sensor to sensor. Two fusion rules; “AND” and “OR” were considered. An ES was tested and a comparison with a genetic algorithm improved by a tournament selection was also analyzed. Among a variety of evolution strategies, the most popular proposed in the literature are the strategy (μ, λ) and the strategy (μ + λ). We proposed an (μ + λ) evolution strategy, by which a self-adaptation mutation is used. The results showed that, although the ES is more difficult to implement and is in a certain manner slower than the GA, it improves the performance of the system.     

Experimental and numerical assessment of using coconut oil as a phase-change material for unconditioned buildings

The efficacy of integrating organic coconut oil (co-oil) phase-change material (PCM) into an unconditioned building with a lightweight envelope is explored experimentally and numerically for heat gain reduction. In what we think is the first test of its kind for co-oil PCM, twin side-by-side single-room buildings (with and without PCM) are constructed and studied experimentally under ambient weather conditions. The effects of the co-oil on the thermal performance of the buildings are investigated with respect to the window orientation (east, west, north and south). Furthermore, numerical simulation of the buildings is carried out to evaluate the contribution of the co-oil to their thermal performance and to determine the effect of the co-oil layer thickness on the heat storage capacity. Moreover, by employing a simplified heat transfer analysis, an approximate relation for the optimal thickness of co-oil PCM layer is developed. Experimental and numerical results show that co-oil PCM can be a promising solution to improve the indoor thermal environment. It is found that with a south-facing window equipped with co-oil PCM, the indoor temperature is lowered by 23.8% compared to the case without PCM, when an optimal PCM layer of ~4 cm in thickness is embedded in the wall.     

Transportation ontology definition and application for the content personalization of user interfaces

Ontologies have been largely exploited in many domains and studies. In this paper, we present a new application of a domain ontology for generating personalized user interfaces for transportation interactive systems. The concepts, relationships and axioms of transportation ontology are exploited during the semi-automatic generation of personalized user interfaces. Personalization deals with the capacity of adaptation of a user interface, reflecting what is known about the user and the domain application. It can be performed on the interface container presentation (e.g., layout, colors, sizes) and in the content provided in their input/output (e.g., data, information, document). In this paper, the transportation ontology is used to provide the content personalization. This paper presents the ontology and how it is used for the personalization of user interfaces for developing transportation interactive systems by model-driven engineering.     

Experimental investigation of a new solar desalination prototype using the humidification dehumidification principle

This paper tackles an experimental investigation of a new solar desalination prototype using the humidification dehumidification principle at the weather conditions of Sfax City, Tunisia. The prototype is designed and constructed at the national engineering school of Sfax to conduct this experimental investigation under different meteorological and operating parameters. It is composed of a flat plate solar air collector, a flat plate solar water collector, a humidifier, an evaporation tower and a condensation tower. An economic analysis was conducted, since it affects the final cost of produced water, to determine both the cost of fresh water production and the payback period of the experimental setup. Although a system may be technically very efficient, it may not be economic. The experimental investigation of the dynamic behaviour of the solar desalination unit during summer season (June, July and August) and during a typical day in July was carried to study the temporal evolutions of the temperature of air and water and the relative humidity at the inlet and the outlet of each component of the system.     

A new non-overlapping block processing technique for realizing linear phase two-pass recursive digital filters

A technique is presented to realize recursive digital filters with a linear phase and arbitrary magnitude characteristics. It is based on a well-known non-causal two-pass forward/backward filtering; where, a non-overlapping segmentwise processing is involved for a real-time implementation. Initial conditions of the backward pass are calculated recursively instead of a direct computation in the previous Arias-de-Reyna and Acha?s non-overlapping method. Additionally, a single first in, first out memory (FIFO) is introduced to organize samples into a data queue structure, and it allows filtering in real-time sample-by-sample. These improvements over the prior non-overlapping method can reduce delays and data storage capacities, and get similar computational complexity and phase linearity precision in passband.We show through the proposed non-overlapping technique that the forward/backward scheme can be a good alternative and competitive over the Powell and Chau?s backward/forward realization. We get better data storage capacities and phase linearity precision in passband, with approximately the same delays. Simulation of group delay precision in agreement with our contributions is illustrated.     

A generalized switching CFAR processor based on test cell statistics

In this paper, a new constant false alarm rate (CFAR) thresholding algorithm which is a generalisation of the switching CFAR (S-CFAR) that takes into account the statistics of the sample in the test cell for reference sample selection is proposed. It employs a composite approach based on the switching CFAR and the order statistic CFAR (OS-CFAR). A mathematical analysis in a homogeneous environment is provided for this detector. The results obtained show that the detection performance of the generalised S-CFAR (GS-CFAR) is improved both in homogenous background and non-homogenous environment caused by interfering targets and clutter edge.     

Development and Characterization of Peptidic Fusion Inhibitors Derived from HIV‐1 gp41 with Partial D‐Amino Acid Substitutions

Interactions between C34 and N36 : Synthetic peptides with D ‐amino acid substitutions that mimic the human immunodeficiency virus (HIV) gp41 HR2 region may lead to new peptidic anti‐HIV‐1 drugs that retain potent antiviral activity while being more resistant to proteolytic degradation.