48 research outputs found
The Coastal Data Information Program, a Successful Federal, State and University Cooperation
International audienceThermal management and heat prediction are essential to improve the Li-ion battery operation life and performance, especially in Energy Storage System (ESS) for electric vehicles. Variation of cells temperatures of a battery pack can cause damage if not managed. In this paper, an electrochemical-thermal battery pack of three parallel-connected cylindrical Li-ion cells is modelled using COMSOL Multi-physics. The battery pack is cooled using air cooling approach with different inlet velocity to investigate its impact on the model temperature evolution , and the developed thermal model was then, charged/discharge at different temperatures to generate the essential data needed to model an electric-thermal model and identify its parameters in Matlab/Simulink software
Toxicological evaluation of Thymelaea hirsuta and protective effect against CCl4-induced hepatic injury in rats
The aerial part of Thymelaea hirsuta (TH) is used as decoction in the treatment of different pathologies in folk medicine in Morocco. The present investigation was carried out to evaluate the potential of toxicity of an aqueous extract of TH and its hepatoprotective activity against CCl4-induced hepatic injury in rats. In the acute study, there were no signs of toxicity observed after oral administration of single dose of the extract (5g/kg body weight). In the sub-chronic dose study, (given by gavages (4 ml/kg) to Wistar rats daily at: 0.0 g/kg, 0.5g/kg, 1 g/kg or 2 g/kg body weight for 4 weeks) no variation on biochemical parameters; serum glucose, creatinine and urea levels was observed compared to the control group. However, the serum levels of alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) were markedly decreased (P < 0.05 and P<0.001 respectively) as compared to the controls. There were no significant differences in red blood cells count (p<0.05), in Hemoglobin and Hematocrit serum levels but a significant increase in white blood cells count (p<0.001) and in platelets (p< 0.05) for all doses tested. Histopathological examination of the liver, spleen and kidneys tissues at the end of the study showed normal architecture. The elevated serum enzymatic activities of ALAT and ASAT, due to carbon tetrachloride treatment (1 ml/kg CCl4 every 72 h during 15 days) were restored towards normalization by the plant extracts. The biochemical observations were supplemented with histopathological examination of liver sections. The results indicate that this plant possesses no toxicity effects but hepatoprotective properties.Keywords: Thymelaea hirsuta, Wistar rats, Toxicity, Histopathology, hepatoprotective action, Folk medicin
Teachers’ Perceptions on Women in STEM: Breaking the Stereotypes
Drawing on an online professional development modular course that addressed critical approaches to the issues of race, immigration, English Language Learners (ELLs)/Emerging Bilinguals (EBs), and gender and sexual orientation, this paper reports teachers’ perceptions on gender stereotypes in Science, Technology, Engineering, and Mathematics (STEM) education. In particular, building on the course readings, we discuss teachers’ emergent approaches to address gender stereotypes in teaching practice that improve girls\u27 participation in STEM fields. Data is collected from a pre-course survey and teachers’ discussions during the course. Centering on the course readings from theoretical and empirical research that address gender issues, discussion prompts were used to elicit teachers’ insights on gender stereotypes in education. A thematic analysis method was then employed to discuss strategies for challenging gender stereotypes in teaching practice from teachers’ discussion posts. Teachers recognize that gender stereotypes have been embedded in the social norms that influence teachers’ practice in an underlying way. Three promising strategies are identified to address gender stereotypes in STEM education, including integrating role models into the curriculum, developing a growth mindset, and promoting justice classroom discourse. We also discussed ways to support teachers in addressing gender stereotypes in their practices
Teaching Emergent Bilinguals: How In-service Teachers’ Perception of First Language Acquisition Theories Inform Practice
Different writers, linguists, and researchers present nuances in language acquisition theories. However, few studies explore in-service teachers’ voices in such discourses. It is, therefore, imperative to explore the voices of in-service teachers in such narratives as they teach emergent bilinguals (EBs) and culturally and linguistically diverse students. This paper examined how in-service teachers perceive First Language Acquisition (FLA) theories and how those perceptions influence teaching EBs and informing classroom practice. Centering on Freeman and Freeman’s discussion of five FLA theories (imitation, reinforcement, behaviorist, social interaction, active construction, connectionist), we argue that in-service teachers’ perceptions of first language acquisition theories impact how they teach and engage EBs in their classrooms. Findings show that in-service teachers consider the social interaction theory most beneficial to students’ language development. However, the precariousness of FLA theories makes it challenging for them to determine the best approach to teaching EBs. Additionally, teacher education programs and critical professional development (PD) courses are instrumental in fostering understanding and robust pedagogical mindsets and preparing teachers to meet the needs of emergent bilinguals.  
Molecular diagnostics for verification of pleural tuberculosis in Morocco
Pleural tuberculosis (pTB) is a very common form of extrapulmonary tuberculosis (TB). pTB diagnostics represents a major burning challenge worldwide due to the limitations of available conventional diagnostic tools. These latter include microscopic examination of the pleural fluid for acid-fast bacilli, mycobacterial culture of pleural fluid in solid or liquid media, sputum or pleural tissue, and histopathological examination of pleural tissue; these tests have recognized limitations for clinical use. Hence, to overcome these limitations, attention has been devoted to new nucleic acid amplification (NAA) diagnostic tests such as the polymerase chain reaction (PCR) and real-time PCR (RT-PCR), owing to their accuracy, rapidity, high sensitivity and specificity. Within this context, this prospective study was conducted to evaluate the performance of molecular diagnosis methods for differentiation between tuberculosis and non-tuberculosis pleural effusions. Fifty patients with pleural effusion were enrolled in this prospective study in Rabat, Morocco. The efficacy of conventional polymerase chain reaction (PCR) in the diagnostics of tuberculous pleurisy by targeting IS6110 and mycobacterial internal transcribed spacer (MYITS) was evaluated compared to histopathologic examination and culture data. Our results showed that IS6110 PCR could “rule in” pTB, the sensitivity and specificity being 41.6% and 85.7%, respectively. Therefore, the findings confirmed that molecular tests exert a relatively high specificity in EPTB but lower sensitivity, thus a positive test is considered as a pTB case whereas negative one cannot exclude the disease. Although the study was limited by a small sample size, it adds to the body of evidence of usefulness of molecular testing as adjuncts to histopathologic examination for accurate diagnosis of pTB, to treat timely and to avoid the emergence and spread of drug resistant pTB. However, further efforts should be made to increase the sensitivity of NAA methods and to identify the best molecular targets to be useful in clinical practice
Bench- and Pilot-Scale Studies of Reaction and Regeneration of Ni–Mg–K/Al2O3 for Catalytic Conditioning of Biomass-Derived Syngas
Electro-thermal coupled battery model : State of charge, core and surface temperatures estimation
International audienceSince their emergence, lithium-ion batteries have played a major role in the growing market of electric vehicles thanks to their characteristics in term of power and energy density. However, the battery expected lifetime is still under investigation since it is influenced by State of charge, temperature and current rates. Which makes battery states prediction and thermal management essential to improve the Li-ion battery performance. Combining a three-state equivalent circuit model and a two-state thermal model, this paper proposes a coupled electro-thermal battery model capturing the State of Charge (SOC), the battery surface and core temperatures. Aiming to control the battery usage and avoid heating, the model is expressed in a state space form in order to allow state estimation and then SOC and thermal effects prediction. A simple state observer and a Robust Non Linear state estimator for SOC estimation are presented and compared. Then a nonlinear observer design for core and surface temperature is modeled, and the results obtained are discussed
Electro-thermal coupled battery model : State of charge, core and surface temperatures estimation
International audienceSince their emergence, lithium-ion batteries have played a major role in the growing market of electric vehicles thanks to their characteristics in term of power and energy density. However, the battery expected lifetime is still under investigation since it is influenced by State of charge, temperature and current rates. Which makes battery states prediction and thermal management essential to improve the Li-ion battery performance. Combining a three-state equivalent circuit model and a two-state thermal model, this paper proposes a coupled electro-thermal battery model capturing the State of Charge (SOC), the battery surface and core temperatures. Aiming to control the battery usage and avoid heating, the model is expressed in a state space form in order to allow state estimation and then SOC and thermal effects prediction. A simple state observer and a Robust Non Linear state estimator for SOC estimation are presented and compared. Then a nonlinear observer design for core and surface temperature is modeled, and the results obtained are discussed
Electro-thermal coupled battery model : State of charge, core and surface temperatures estimation
International audienceSince their emergence, lithium-ion batteries have played a major role in the growing market of electric vehicles thanks to their characteristics in term of power and energy density. However, the battery expected lifetime is still under investigation since it is influenced by State of charge, temperature and current rates. Which makes battery states prediction and thermal management essential to improve the Li-ion battery performance. Combining a three-state equivalent circuit model and a two-state thermal model, this paper proposes a coupled electro-thermal battery model capturing the State of Charge (SOC), the battery surface and core temperatures. Aiming to control the battery usage and avoid heating, the model is expressed in a state space form in order to allow state estimation and then SOC and thermal effects prediction. A simple state observer and a Robust Non Linear state estimator for SOC estimation are presented and compared. Then a nonlinear observer design for core and surface temperature is modeled, and the results obtained are discussed