Étude de la dégradation d’une canalisation de conduite d’eau en béton armé

Dans ce travail nous nous sommes intéressés à l’étude des causes de dégradation d’une canalisation en béton armé dans la région de l’oriental au Maroc. Cet ouvrage est utilisé pour transporter de l’eau potable. L’altération de l’ouvrage n’a été constatée et de manière sévère que sur un tronçon bien situé. Dans ce cadre on a procédé à la détermination des causes de dégradation. Pour cela nous avons effectué un prélèvement d’échantillons du tronçon dégradé et de part et d’autre. Des échantillons témoins ont été réalisés à l’usine de fabrication des canalisations.Nous avons effectué le dosage de la teneur en chlorure et en ciment, étudié l’impact de la carbonatation et déterminé les pourcentages en silice et carbonates. Nous avons aussi mis au point la présence des ionschlorures en pourcentage assez important pouvant être responsable de la corrosion des aciers de frettage des tuyaux en béton précontraint et par conséquent des dégradations affectant ces tuyaux. La présence d’unenvironnement humide aurait favorisé la dégradation. Par ailleurs, la détermination de la teneur en chlorures par rapport à la masse de ciment a nécessité la détermination du pourcentage de ciment contenu dans le béton. Nous avons utilisé la méthode dite des inertes. La détermination de la teneur en anhydre carbonique CO2 a été réalisée par calcimétrie. Les résultats obtenus montrent que nous sommes en présence d’un béton ayant subi une légère carbonatation et contenant à la fois des teneurs en chlorures dépassant largement le seuil d’amorçage de la corrosion.Mots-clés : dégradation, canalisation, béton armé, corrosion, carbonatation

Mejora de la producción de lípidos de un prometedor hongo oleaginoso Aspergillus sp. cepa EM2018 para la formación de biodiesel: optimización de las condiciones de cultivo e identificación

Oleaginous fungi have recently gained increasing attention among different microorganisms due to their ability for lipid production for the preparation of biofuel. In the present study, a locally isolated fungus E45, identified genetically as Aspergillus sp. strain EM2018, was found to produce 25.2% of the total lipids content of its dry cell weight (DCW). Optimization of culture conditions was performed and lipid accumula­tion increased by about 2.4 fold (from 25.2% to 60.1% of DCW) when the fungus was grown for seven days in the potato dextrose (50 g/L) liquid medium at pH 5.0, incubation temperature at 30 ºC and inoculum size of 2 × 106 spore/mL. Supplementation of the medium with yeast extract and NaNO3 at a concentration of 0.05% as organic and inorganic nitrogen sources, respectively, increased lipid production (53.3% lipid/dry biomass). Gas chromatography analysis of fungal lipids revealed the presence of saturated (mainly palmitic acid C16:0 (33%) and lignoceric acid C24:0 (15%)) and unsaturated fatty acids in different proportions (mainly linoleic acid C18:2 (24.4%), oleica cid C18:1 (14%) and arachidonic C20:4 (7.4%). These findings suggest this new oleaginous fungus as a promising feedstock for various industrial applications and for the preparation of biodiesel.Los hongos oleagino­sos recientemente están ganando una creciente atención entre diferentes microorganismos debido a sus capaci­dades de producción de lípidos para la preparación de biocombustibles. En el presente estudio, se descubrió que un hongo E45 aislado localmente, identificado genéticamente como la cepa Aspergillus sp. EM2018, produce un 25,2% de lípidos totales de su peso de células secas (DCW). Se realizó la optimización de las condiciones de cultivo y la acumulación de lípidos se incrementó aproximadamente 2,4 veces (del 25,2% al 60,1% de DCW) cuando el hongo creció durante siete días en un medio líquido de dextrosa de papa (50 g/L) a pH 5.0, 30 °C de temperatura de incubación y 2 × 106 esporas/ml de tamaño de inóculo. La suplementación del medio con extracto de leva­dura y NaNO3 a una concentración de 0,05% como fuentes de nitrógeno orgánico e inorgánico, respectivamente, aumentó aún más la producción de lípidos (53,3% de lípidos/biomasa seca). El análisis mediante cromatografía de gases de los lípidos fúngicos reveló la presencia de ácidos grasos saturados (principalmente palmítico C16:0 (33%) y lignocérico C24:0 (15%)) y ácidos grasos insaturados en diferentes proporciones (principalmente linoleico C18:2 (24.4%), oleico C18:1 (14%) y araquidónico C20:4 (7,4%). Estos hallazgos sugieren que este nuevo hongo oleaginoso es una materia prima prometedora para diversas aplicaciones industriales y preparación de biodiésel

Renal cell carcinoma in children: Case report and literature review

Renal cell carcinoma is infrequent in children; consequently it is important to communicate its diagnosis and follow up. The behaviour of this type of tumor is better characterized in adults and in this setting the treatment of choice is surgical resection. However, the place of chemo- and radiotherapy has not been well defined. Here, we present a 9-year-old boy with renal cell carcinoma demonstrating only hematuria without any pathological physical examination findings. The mass was described by abdominal ultrasonography and computed tomography in the left kidney. After the left nephroureterectomy, the patient was given no adjuvant therapy

Time-Resolved IR Spectroscopy Reveals a Mechanism with TiO2 as a Reversible Electron Acceptor in a TiO2 - Re Catalyst CO2 Photoreduction System

Attaching the phosphonated molecular catalyst [Re$^{I}$Br(bpy)(CO)₃]⁰ to the wide-band gap semiconductor TiO₂ strongly enhances the rate of visible-light driven reduction of CO₂ to CO in dimethyl formamide (DMF) with triethanolamine (TEOA) as sacrificial electron donor. Herein, we show by transient mid-IR spectroscopy that the mechanism of catalyst photoreduction is initiated by ultrafast electron injection into TiO₂, followed by rapid (ps-ns) and sequential two-electron oxidation of TEOA that is coordinated to the Re center. The injected electrons can be stored in the conduction band (CB) of TiO₂ on a ms-s time scale, and we propose they lead to further reduction of the Re-catalyst and completion of the catalytic cycle. Thus, the excited Re catalyst gives away one electron and would eventually get three electrons back. The function of an electron reservoir would represent a role for TiO₂ in photo-catalytic CO₂ reduction that has previously not been considered. We propose that the increase in photocatalytic activity upon heterogenisation of the catalyst to TiO₂ is due to the slow charge recombination and the high oxidative power of the ReII species after electron injection, as compared to the excited MLCT state of the unbound Re catalyst or when immobilized on ZrO₂, which results in a more efficient reaction with TEOA.Knut and Alice Wallenberg Foundation, Swedish Energy Agency, Swedish Research Council, Austrian Christian Doppler Research Association, OMV Grou

DFT, TD-DFT and biological activity studies of some maleanilic acid derivatives ligands and their organometallic complexes

1564-1573This study is a complementary study to our previous study that included the synthesis and characterization of some maleanilic acid derivative ligands (L1-4) and their metal carbonyl complexes (2-4)a-d as effective compounds for cancer cell growth inhibition against three cancer cell lines: HCT-116, HepG-2 cells and MCF-7. The activity data has manifested that the p-nitrophenyl maleanilic acid ligand (L2) and its chromium complex (2b) inhibited the tested cancer cells more effectively than the other complexes. Additionally, DFT and TD-DFT studies are performed to investigate their frontier molecular orbital (FMO), optical properties, and the correlation between the structure and biological activity. The calculated optical energy gap (Eg) is in the range of 1.78- 2.13 eV, and electron cloud delocalization of HOMO/LUMO levels revealed that all complexes show effective charge separation. The DFT results show a strong relation between Eg values of the carbonyl complexes and their experimental biological activity, where it is obvious that complex (2b) with the lowest Eg value has the greatest inhibitory potency against cancer cells. In contrast, complex (2d) with the highest Eg value exhibits the lowest inhibition potency. These findings translate the inverse relationship between Eg values of the complexes and the inhibition potency against cancer cells

DFT, TD-DFT and Biological Activity Studies of Some Maleanilic Acid Derivatives Ligands and Their Organometallic Complexes

This study is a complementary study to our previous study that included the synthesis and characterization of some maleanilic acid derivatives ligands (L1-4) and their metal carbonyl complexes (2-4)a-d as effective compounds for cancer cell inhibition against three cancer cell lines: HCT-116 (colon cancer), HepG-2 cells (Hepatocellular cancer) and MCF-7 (breast cancer). The activity data manifested that p-nitrophenyl maleanilic acid ligand (L2) and its chromium complex (2b) showed higher inhibitory than the other complexes against the tested cancer cells. Additionally, DFT and TD-DFT studies were performed to investigate their frontier molecular orbital (FMO), optical properties, and the correlation between the structure and biological activity. The calculated optical energy gap (Eg) was in the range of 1.78- 2.13 eV, and electron cloud delocalization of HOMO/LUMO levels revealed that all complexes show effective charge separation. DFT results show a great relation between Eg values of the carbonyl complexes and their experimental biological activity. Where it was obvious that complex (2b) with the lowest (Eg) value exhibits the highest inhibition potency against cancer cells. In contrast, complex (2d) with the highest (Eg) value exhibits the lowest inhibition potency. These results translate the reverse relationship between Eg values of the complexes and the inhibition potency against cancer cells

Tailoring hyper-heuristics to specific instances of a scheduling problem using affinity and competence functions

Hyper-heuristics are high level heuristics which coordinate lower level ones to solve a given problem. Low level heuristics, however, are not all as competent/good as each other at solving the given problem and some do not work together as well as others. Hence the idea of measuring how good they are (competence) at solving the problem and how well they work together (their affinity). Models of the affinity and competence properties are suggested and evaluated using previous information on the performance of the simple low level heuristics. The resulting model values are used to improve the performance of the hyper-heuristic by tailoring it not only to the specific problem but the specific instance being solved. The test case is a hard combinatorial problem, namely the Hybrid Flow Shop scheduling problem. Numerical results on randomly generated as well as real-world instances are included

Combined quay crane assignment and quay crane scheduling with crane inter-vessel movement and non-interference constraints

Integrated models of the quay crane assignment problem (QCAP) and the quay crane scheduling problem (QCSP) exist. However, they have shortcomings in that some do not allow movement of quay cranes between vessels, others do not take into account precedence relationships between tasks, and yet others do not avoid interference between quay cranes. Here, an integrated and comprehensive optimization model that combines the two distinct QCAP and QCSP problems which deals with the issues raised is put forward. The model is of the mixed-integer programming type with the objective being to minimize the difference between tardiness cost and earliness income based on finishing time and requested departure time for a vessel. Because of the extent of the model and the potential for even small problems to lead to large instances, exact methods can be prohibitive in computational time. For this reason an adapted genetic algorithm (GA) is implemented to cope with this computational burden. Experimental results obtained with branch-and-cut as implemented in CPLEX and GA for small to large-scale problem instances are presented. The paper also includes a review of the relevant literature

Risk factors of osteoporosis in healthy Moroccan men

<p>Abstract</p> <p>Background</p> <p>Although not as common as in women, osteoporosis remains a significant health care problem in men. Data concerning risk factors of osteoporosis are lacking for the male Moroccan population. The objective of the study was to identify some determinants associated to low bone mineral density in Moroccan men.</p> <p>Methods</p> <p>a sample of 592 healthy men aged 20-79 years was recruited from the area of Rabat, the capital of Morocco. Measurements were taken at the lumbar spine and proximal femurs using DXA (Lunar Prodigy Vision, GE). Biometrical, clinical, and lifestyle determinants were collected. Univariate, multivariate, and logistic regression analyses were performed.</p> <p>Results</p> <p>the mean (SD) age of the patients was 49 (17.2) years old. The prevalence of osteoporosis and osteopenia were 8.7% and 52.8%, respectively. Lumbar spine and hip BMD correlated significantly with age, weight and BMI. When comparing the subjects according to the WHO classification, significant differences were revealed between the three groups of subjects for age, weight and BMI, prevalence of low calcium intake and low physical activity. The multiple regression analysis found that only age, BMI, and high coffee consumption were independently associated to the osteoporotic status.</p> <p>Conclusion</p> <p>ageing and low BMI are the main risk factors associated with osteoporosis in Moroccan men.</p