22 research outputs found
A microsimulation-based analysis for driving behaviour modelling on a congested expressway
No full textRecently, simulation models have been widely used around the world to evaluate the performance of different traffic facilities and management strategies for efficient and sustainable transportation systems. One of the keys factors for ensuring the reliability of the models in reflecting local conditions is the calibration and validation of microsimulation models. The majority of the existing calibration efforts focus is on the experimental designs of driver behaviour and lane-changing parameters. Towards this end, this paper describes the necessary procedure for the calibration and validation of a microscopic model using the VISSIM software, during peak hours. The procedure is applied on Muscat Expressway in the Sultanate of Oman. The calibration parameters and the measure-of-effectiveness are identified by using multi-parameter sensitivity analysis. The optimum values for these parameters are obtained by minimising errors between simulated data and field data. In our proposed model, we used traffic volume and travel speed for model calibration, as well as average travel time for validation of the calibrated model. The achieved results showed that driving characteristics significantly impacted the merging/diverging traffic flow ratio in the merging area, the link length and the distance between on-ramps and off-ramps, as well as the percentage of heavy vehicles. The results also showed that having both the advanced merging and cooperative lane-change settings active, along with safety distance reduction factor, necessary lane change, minimum headway (front/rear), and emergency stop, had a significant influence on simulation precision, especially at on-ramps and off-ramps. Finally, our proposed model can be utilized as a base for future traffic strategy analysis and intelligent transportation systems evaluation to help decision makers with long-term and sustainable development decisionsFarrag, SG (corresponding author), Hasselt Univ, Transportat Res Inst, Hasselt, Belgium.
[email protected]; [email protected]; [email protected]; [email protected]; [email protected], SG (corresponding author), Hasselt Univ, Transportat Res Inst, Hasselt, Belgium.
[email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Corrigendum to "Investigations into structure-property relationships of novel Ru(II) dyes with N,N'-Diethyl group in ancillary ligand for dye-sensitized solar cells" [Dyes Pigments 171(2019) 107754-107762](S0143720819314639)(10.1016/j.dyepig.2019.107754)
No full textThe authors regret the typos in the author names and affiliations. The authors would like to apologize for any inconvenience caused. Correction: The correct author names and affiliations should read as follows: Saba Ashrafa,b,d, Rui Sud, Javeed Akhtarc, Humaira M. Siddiqib, Ahmed Shujae, Khalid Al-Saadf, Siham Y. Al-Qaradawif, Ahmed El-Shafeid*[email protected] aSulaiman Bin Abdullah Aba Al-Khail - Centre for Interdisciplinary Research in Basic Science (SA-CIRBS), International Islamic University, Sector H-10, Islamabad, Pakistan bDepartment of Chemistry, Quaid-I-Azam University, Islamabad, 45320, Pakistan cMaterials Laboratory, Department of Chemistry, Mirpur University of Science and Technology (MUST), Mirpur, 10250, AK, Pakistan dPolymer and Color Chemistry Program & Fiber and Polymer Science Program, North Carolina State University, Raleigh, NC, 27606, USA eCentre for Advanced Electronics and Photovoltaic Engineering (CAEPE), International Islamic University, Sector H-10, Islamabad, Pakistan fDepartment of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, QatarScopu
La politique de communication ou comment gérer son image par des règles partagées
No full textDans un environnement sociopolitique dynamique, les organisations sont soucieuses de développer une image publique appropriée. Cela ne peut se réaliser que par l’adoption d’une véritable politique de communication. Cet outil stratégique permet de contrôler les flux communicationnels tant à l’interne qu’à l’externe, notamment dans un contexte technologique influant sur la circulation de l’information. L’auteur expose les particularités de cette politique, les modalités de son élaboration et de sa mise en œuvre.In a constantly changing socio-political environment, organizations tend to develop and maintain a good public image. This can be done by adopting a communication policy. This strategic tool allows to control communication flows both internally and externally, notably in a technological context affecting the circulation of information. The author examines the properties of this policy, the methods of its elaboration and its implementation
Study of Moroccan Monumental Heritage Traditional for Valorization and Conservation of Collective Memory and for Socio-eco- Tourism Sustainable Development-case Kasbah Chellah, Rabat
No full textAbstractLike any historical monument flap and around the world, the archaeological site of Chellah named world heritage known chemical and physical degradation due to known natural agents: rainwater, runoff, temperature, humidity, ground movement, bacteria and air pollution. To remedy these degradations several actions were taken by the authorities concerned, but these actions were traditional, superficial and temporary and therefore they brought little lasting remedy to such degradation. To do this, we will try in the present work to analyze these factors degrading to better design the inventory of the monument Chellah
The Effect of Consciousness- Raising Tasks on Improving Algerian EFL Students’ Use of Discourse Markers in Speaking
No full textThe investigation described in this dissertation aims at studying some aspects of spoken discourse which are discourse markers, and will consider in particular the production of those devices by EFL students of English as well as the effect of consciousness-raising tasks on improving discourse competence and communicative language performance of non-native speakers of English in Algeria. In this context a quasi experimental research was adopted consisting of two groups of twenty (20) Algerian students each belonging to first year English LMD: one constitutes the experimental group while the other represents the control one. Theexperiment was conducted in three phases during which three techniques were adopted in the collection of the required data; i.e. we employed two written tests (a pre- test and a post- test), two interviews (from which we derived student corpora) and a questionnaire. The study reveals some development in the students’ discourse competence as far as the use of spoken discourse markers is concerned; nevertheless, a discrepancy is noticed in the frequency and use of those targeted features when compared with a subcorpus of native speakers’ talks containing 460,050 words, already employed by the author [15], selected from the whole CANCODE pedagogical corpus. Moreover, the investigation unveiled that some discourse markers were overused or underused whereas others were misused or not used at all
SPECTROSCOPIC STRUCTURAL INVESTIGATIONS OF CHARGE-TRANSFER COMPLEXES OF n-DONORS AND SIGMA- AND PI-ACCEPTORS
No full textAuthor Institution: Department of Chemistry and Earth Sciences, Qatar University, P.O.Box 2713 Doha, QatarMolecular charge transfer complexes of n-electron donors such as amines, pyridines and polynitrogen cyclic bases with both sigma- and pi-acceptors have been studied spectrophotometrically in chloroform. The reaction stoichiometries were determined using photometric titration methods. The formed CT-complexes are characterized and formulated based on electronic and infrared spectra as well as elemental and thermal measurements
Determination of the structural and optoelectronic properties of InTe cubic monochalcogenide using the WIEN2k code for its application in photovoltaics
No full textThe present study aims to investigate the structural and optoelectronic properties of the InTe cubic monochalcogenide for its application in the field of photovoltaics as a solar reflector, owing to its high optical reflectivity in the visible and ultraviolet range. We focused on this material due to its limited exploration in the literature. These studies were conducted using density functional theory (DFT), employing the WIEN2k software and the full-potential linearized augmented plane wave (FP-LAPW) method. The Local Density Approximation (LDA) was used as an approximation for considering the electron exchange-correlation energy. We optimized the volume to obtain the optimized cell structure based on the minimum energy criterion, which will be used in subsequent calculations. The calculated structural parameters closely align with experimental values. The band structure and density of states (DOS) calculations indicate that the InTe cubic monochalcogenide is metallic, with a total density (TDOS) at the Fermi level of approximately 1.2 states/eV. Optical properties were also calculated for radiations up to 14 eV. The results suggest that this material could be employed as an efficient solar reflector to mitigate heating effects from solar radiation, thereby improving the efficiency of photovoltaic installations through the judicious use of InTe reflective material
The Sidi Moussa-Oualidia wetland complex A Bird Paradise between land and sea
No full textThe Sidi Moussa-Oualidia wetland complex is a unique natural ecosystem of significant national and international importance, as designated by the Ramsar Convention. Located in the Moroccan Atlantic zone between El Jadida and Oualidia, this wetland fulfils many functions. The most important are the rich biodiversity, ecological, hydrological, and economic functions are the most important. Regular censuses, carried out during winter between 1993 and 2022 in the Sidi Moussa-Oualidia lagoon complex, made it possible to determine the composition of the waterbird population that frequents this site and to define the status of the various encountered species. Emphasis was also made on the value of this complex, particularly for breeding, based on monitoring work and our unpublished observations. Ninety-six (96) species frequented the site, 51 of which are regular. Waders represent the most dominant group, followed by Laridae and Anatidae. The remaining groups, poorly represented in numbers, total some 29 species, of which twelve (12) are accidental or rare, and nine (9) are mainly observed outside the wintering period. However, some species are particularly interesting, such as the Greater Flamingo, the Eurasian Spoonbill, and the Red-knobbed Coot. Of the 51 regular species in the site, 16 are breeding ones, including species classified as threatened or near-threatened on the global red list (Marbled Teal, Ferruginous Duck) and others considered threatened in Morocco (Purple Swamphen, Red-crested Pochard), rare (Little Tern) or remarkable (Red-knobbed Coot). Despite this ornithological richness, the site is subject to multiple constraints. Creating a specific administrative structure similar to an 'Agency for the development of the Sidi Moussa-Oualidia complex' could be a potential solution for the control, rational management, and sustainable local development
First-Principles study of high-temperature thermoelectric performance induced by hydrogenation of ZnAs and CdAs monolayers
No full textMotivated by the improved electronic properties of the isostructural hydrogenated ZnSb monolayers, we investigate the thermoelectric efficiency in the hydrogenated ZnAs and CdAs monolayers (i.e., ZnAsH and CdAsH) at temperatures of 300 K and 900 K using Boltzmann transport theory while accounting for multiple carrier scattering mechanisms. Our results reveal that hydrogenation modifies the band structures of ZnAsH and CdAsH, inducing a transition from metallic to semiconducting behavior (1.89 eV for ZnAsH and 1.23 eV for CdAsH. The cohesive energy, formation energy, phonon spectrum, ab initio molecular dynamics (AIMD), and elastic constants confirm their robust stability. The electronic transport analysis shows that p-type ZnAsH and CdAsH exhibit high Seebeck coefficient of 225.42μV/K and 409.45μV/K respectively, along with high electrical conductivity. Small group velocity, strong anharmonicity, and high scattering rates lead to ultralow lattice thermal conductivities of 3.36(3.74) W/mK for the ZnAsH monolayer and 0.23(0.35) W/mK for the CdAsH monolayer in the x(y) directions. The electronic part of the thermal conductivity is consistent with predictions from the Wiedemann–Franz law. Combining the excellent electronic transport with ultralow lattice thermal conductivity, we achieve optimal ZTs of 0.53 for ZnAsH and 3.72 for CdAsH in the x-direction. These findings suggest that hydrogenated monolayers are promising candidates for thermoelectric (TE) technology
