Numerical Study on Improving Indoor Thermal Comfort Using a PCM Wall

A one-dimensional mathematical model was developed in order to analyze and optimize the latent heat storage wall. The governing equations for energy transport were developed by using the enthalpy method and discretized with volume control scheme. The resulting algebraic equations were next solved iteratively by using TDMA algorithm. A series of numerical investigations were conducted in order to examine the effects of the thickness of the PCM layer on the thermal behavior of the proposed heating system. Results are obtained for thermal gain and temperature fluctuation. The charging discharging process was also presented and analyzed

NEUROPSYCHOLOGICAL APPROACH OF FACTORS AGGRAVATING THE READING LEARNING DIFFICULTIES AMONG MOROCCAN ARABIC-SPEAKING STUDENTS WITH DEVELOPMENTAL DYSLEXIA PROFILE

Dyslexia is the most common learning disability in school and the most devastating in terms of academic performance. In interaction with the socio-cultural environment, several and various factors can aggravate the difficulties of reader acquisition in dyslexic children. Identifying these factors and interpreting them according to the neuropsychological approach, in the Moroccan context, was the objective of this study Socio-economic data was collected from 626 children, aged 9 to 15 years with an average age of 11,95 years, enrolled in public educational establishments in the Beni Mellal-Khenifra region, located in central Mo- rocco. Among all the participants, 41 had a profile of dyslexia, 13 of whom had reading attitudes evoking "severe dyslexia". Subjects underwent a cognitive assessment. the others were normal-readers and classified as good readers (n=481) and weak readers (n=104). To follow our purpose, we have determined socio-cultural and cognitive variables that may discriminate between students in the "severely dyslexic" group and their "dyslexic" peers. The performance gap was significant in favor of "dyslexic" students in the reading test of pseudowords, rapid naming of images, and the deletion of the initial phoneme. These data reinforce the hypothesis that the phonological deficit is at the root of developmental dyslexia. On the socio-cultural domain, the results showed that preschool attendance and early exposure to written language activity discriminate the participants with a "severe dyslexia" profile from their peers in the "dyslexic" group. We believe that these two factors were responsible for the moderate intensity of the disorder observed in the "dyslexic" group. Our study also showed that bilingualism raises the degree of learning reading difficulties among students with this disorder. These results are consistent with those described in the literature, it suggests that dyslexics can implement compensation strategies both at the behavioral and neuronal level. They call on those in charge of the Moroccan education system to recognize the existence of learning disabilities of neurobiological origin in order to address the necessary care for children who suffer from them

Experimental and Numerical Investigations on Conductive Drying of Phosphate Washing Waste Clay

Morocco is the leading producer of phosphate and its derivatives in the world with a total production of 35 Mt. However, the extraction and the valorization of this mine generate huge quantities of phosphate washing waste clay (PHWWC) that constitute a main environmental and economic concern. To facilitate this waste clay storage and handling, it is necessary to decrease its moisture content that represents 80% of PHWWC. The present paper is devoted to studying the conductive drying of PHWWC. Drying experiments were conducted in a laboratory pilot. Afterwards, the experiment results were implemented in a one-dimensional numerical model of heat and mass transfer in a porous media to identify the drying parameters and performances. It was found that most of the water contained in PHWWC is free water that is removed with a constant drying rate. The volume reduction with a marked cracks phenomenon attained 65% without any significant effect of drying temperature and sample thickness. The effective moisture diffusivity of the PHWWC for a conductive drying process is ranged between 10−9 and 1.1 × 10−8 m2·s−1. The thermal efficiency of the drying system is up to 86%. The results could be used for the purpose of design and scale-up of the industrial dryer based on laboratory-scale experiments