- - Using an Interactive Whiteboard to Enhance Language Teaching in Higher Education: a Libyan EFL Teacher’s Perspective: Computer assisted language learning/Applied linguistics in action. Journal of languages faculty, Tripoli University, issue 13, 2016

Lean premixed swirl stabilised combustion is regarded as one of the most successful technologies for flame control and NOx reduction. The important characteristics of these flows are the good mixing, flame stability through the formation of a Central Recirculation Zone, and the low emissions at lean conditions as a consequence of temperature drop. Now the potential wide range of available fuels presents a problem in terms of variation of heating values, flame speeds and chemical reactivity. Process, refinery gases and gasified coal or biomass are just a few examples. The biggest challenge to fuel-flexibility of most combustors is the large differences between natural gas and the proposed replacement fuels which causes variations in the stability profiles of the combustion process. In this paper, lean premixed swirl combustion of CH 4 /H 2 /CO fuel mixtures was investigated experimentally and numerically to understand the impacts of these fuels on fundamental stability phenomena such as blowoff. The swirl burner used was operated at atmospheric pressure and ambient temperature using a moderate swirl number. Different nozzles were used to determine the impact of the blends on the Central Recirculation Zones. Methane content in the fuel was decreased from 50% to 0% (by volume) with the remaining amount split equally between carbon monoxide and hydrogen. Chemical kinetic analyses were carried out using PRO-CHEMKIN to determine flame speeds and chemical properties needed for CFD calculations. Experiments were done using a Phase Locked PIV system. The Central Recirculation Zone and its turbulence were measured and correlated providing details of the structure close to blowoff. The results show how the strength and size of the recirculation zone are highly influenced by the blend, with a shift of turbulence based on carbon-hydrogen ratio, nozzles effects on the shearing flow and Re numbers. Correlation with the phenomenon was also achieved using the k-cc SST CFD model, providing more information about the impact of the CRZ and the flame turbulent nature close to the blowoff limit.

In this paper, we first recall the definition of a family of Koenig’s root-

finding algorithms known as Koenig’s algorithms (𝐾௣,௡) for polynomials. In the whole

paper p has degree 𝑑 ≥ 2 with real coefficients and real (and simple) zeros 𝑥௞ , 1 ≤

𝑘 ≤ 𝑑 .

Now we want to discuss Koenig’s algorithms in details where

𝑛 = 4, (𝐾௉,ସ(𝑧)).

Corrugated composite plate with different profile may be of interest for energy absorption application due to their improved crashworthiness. In the current paper, square profile corrugated composite plates made of fiber glass reinforced plastic (FGRP) are introduced as energy absorption structure. Different arrangements of the corrugated plate are tested. In addition to that, the effect of placing a flat composite plate made from same material is studied experimentally. Multilayers (single, double, and triple layers) of the square profile corrugated composite plates have been fabricated and tested under the same condition. The tested specimens are subjected to quasi-static compression load. The well-known crashworthiness parameters are being recorded and used to compare the different configurations.

The article presents the effect of dimensions and geometry on the crushing behavior, energy absorption, failure mechanism, and failure mode of woven roving glass fiber/epoxy laminated composite tube. Three sizes (big CCT1, medium CCT2, and small CCT3) of cylindrical composite tubes (CCT) were fabricated and tested under the same conditions. Comprehensive experimental work was conducted that includes axial and lateral quasi-static crushing test to examine the influence of the design parameters on the energy absorption characteristics of CCT. Load–displacement curves and deformation histories were presented and discussed. Different parameters were obtained from studying of load–displacement curves, these parameters are: initial failure load, average crushing load, and total energy absorption.

The main objective of this article is to study composite structures as an energy absorption system. The method of approach has been to fabricate and test a series of composite plates with sinusoidal corrugation profile. These plates have been subjected to compression load. In order to achieve this aim, an extensive experimental as well as theoretical study has been conducted. Tested specimens were fabricated and tested in the same conditions. In addition to that, multi layers of composite plates with sinusoidal profiles were fabricated and tested. Results showed that the specific energy absorption and load carrying capacity increased with the increase of the number of corrugated plates. It has been found that, the relationship between the two factors is directly proportional.