124 research outputs found

    Evaluation of the impact of wastewater in the rural commune of Jmaa Moulblad on the bacteriological water quality of the Grou River (Rabat region, Morocco)

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    In the region of Rabat, shallow watercourses are currently threatened by the magnitude of urban and industrial discharges, mainly due to its growing demography and the continuous development of the agricultural and industrial sectors. This study aims to evaluate the impact of wastewater from the rural commune of Jmaa Moulblad on the bacteriological water qualityof the Grou River. In order to measure the pollution levels of this watercourse, our study focused on the enumeration of fecal contamination indicator bacteria such as total coliforms (TC), faecal coliforms (FC) and intestinal enterococci (EI), as well as the detection of salmonella. Water samples were taken by season during the 2016/2017 period at four stations on the Grou River. The results obtained describe a worrying state of the watercourse, particularly at the S2 station located directly at the mouth of the wastewater of the rural commune of Jmaa Moulblad which is rejected without prior treatment. If protective measures are not taken, the perpetual degradation of the quality of these waters would certainly lead to the loss of this watercourse, which is of paramount importance in the region.

    Physicochemical and microbiological quality of the treated wastewater of the Marrakech WWTP for irrigation

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    The urban district of Marrakech has a wastewater treatment plant of activated sludge type. Water treated by this WTTP is intended for the irrigation of golf courses. Tertiary treatment can extract any undesirable substance not removed by the steps before. The aim of this work is to characterize the physico-chemical and microbiological quality of the treated water  and to assess the effectiveness of tertiary treatment. The pH varies between 7.1 and 7.7 which is in the range recommended by both the Moroccan and the USEPA standards. The COD content fluctuates between 24.87 and 52.33 mg O2 / l, which is below the limit value of 60 mg O2 / l recommended by the French legislation. Concentrations of BOD5 range is between 1.1 and 4.21 mg O2 / l which is widely below the standard of 30 mg O2 / l recommended by the WHO and USEPA for the reuse of treated wastewater. For the SM, the value of 30 mg / l is the threshold set by both the WHO, USEPA and French law. The values ​​of SM fluctuate between 2.86 and 8.46 mg / l which are perfectly in accordance with the recommended standard. The content of nitrates does not exceed 5 mg N / l is lower than the limit set by WHO and the Moroccan standard of 30 mg N / l. The TP content is between 1,88 and 6,23 mg P / L compared with the range 6-20 mg / l agreed by WHO. The microbiological analysis, including research faecal coliforms show that the values ​​obtained are below standard 200, 250 and 1000 UF / l respectively recommended by the USEPA, the French legislation and concomitantly the Moroccan standard and WHO . However, the parasitology examination especially of nematodes attests their total absence, showing the effectiveness of the tertiary treatment. Finally, the water at the outlet of the WWTP of Marrakech, destinated for irrigation has a physicochemical and microbiological quality compliant for irrigation.

    Superspin glass aging behavior in textured and nontextured frozen ferrofluid

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    The effect of magnetic anisotropy-axis alignment of individual nanoparticles on the collective aging behavior in the superspin glass state of a frozen ferrofluid has been investigated. The ferrofluid studied here consists of maghemite nanoparticles (\gamma-Fe2O3, mean diameter = 8.6 nm) dispersed in glycerin at a volume fraction of ~15%. The low temperature aging behavior has been explored through 'zero-field cooled magnetization' (ZFCM) relaxation measurements using SQUID magnetometry. The ZFCM response functions were found to scale with effective age of the system in both textured and non-textured superspin glass states, but with markedly different scaling exponents, \mu. The value of {\mu} was found to shift from ~0.9 in non-textured case to ~ 0.6 in the textured case, despite the identical cooling protocol used in both experiments

    Produtos de hidratação em argamassas geopoliméricas à base de argila da Tunísia para reparação de estruturas de concreto

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    A reparação de estruturas degradadas de concreto representa uma oportunidade para a indústria da construção mas também um desafio para a comunidade científica. O desenvolvimento de novas argamassas de reparação constitui por isso uma importante área de investigação. Os geopolímeros são ligantes inovadores alternativos ao cimento Portland pelo que as argamassas à base destes materiais, geopolíméricas, apresentam algumas potencialidades no campo da reparação das estruturas de concreto. O presente artigo apresenta resultados de uma investigação sobre o desenvolvimento de argamassas geopoliméricas à base de uma argila da Tunísia sujeita a tratamento térmico. É incluída uma análise da argila e também dos produtos de hidratação da argamassa os quais apresentam fases geopoliméricas típicas

    Clique-Finding for Heterogeneity and Multidimensionality in Biomarker Epidemiology Research: The CHAMBER Algorithm

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    Commonly-occurring disease etiology may involve complex combinations of genes and exposures resulting in etiologic heterogeneity. We present a computational algorithm that employs clique-finding for heterogeneity and multidimensionality in biomedical and epidemiological research (the "CHAMBER" algorithm).This algorithm uses graph-building to (1) identify genetic variants that influence disease risk and (2) predict individuals at risk for disease based on inherited genotype. We use a set-covering algorithm to identify optimal cliques and a Boolean function that identifies etiologically heterogeneous groups of individuals. We evaluated this approach using simulated case-control genotype-disease associations involving two- and four-gene patterns. The CHAMBER algorithm correctly identified these simulated etiologies. We also used two population-based case-control studies of breast and endometrial cancer in African American and Caucasian women considering data on genotypes involved in steroid hormone metabolism. We identified novel patterns in both cancer sites that involved genes that sulfate or glucuronidate estrogens or catecholestrogens. These associations were consistent with the hypothesized biological functions of these genes. We also identified cliques representing the joint effect of multiple candidate genes in all groups, suggesting the existence of biologically plausible combinations of hormone metabolism genes in both breast and endometrial cancer in both races.The CHAMBER algorithm may have utility in exploring the multifactorial etiology and etiologic heterogeneity in complex disease

    Lack of association between polymorphisms of the IL18R1 and IL18RAP genes and cardiovascular risk: the MORGAM Project

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    <p>Abstract</p> <p>Background</p> <p>Interleukin-18 is a pro-inflammatory cytokine suspected to be associated with atherosclerosis and its complications. We had previously shown that one single nucleotide polymorphism (SNP) of the <it>IL18 </it>gene was associated with cardiovascular disease (CVD) through an interaction with smoking. As a further step for elucidating the contribution of the IL-18 pathway to the etiology of CVD, we here investigated the association between the genetic variability of two IL-18 receptor genes, <it>IL18R1 </it>and <it>IL18RAP</it>, with the risk of developing CVD.</p> <p>Methods</p> <p>Eleven tagging SNPs, 5 in <it>IL18R1 </it>and 6 in <it>IL18RAP</it>, characterizing the haplotypic variability of the corresponding genes; were genotyped in 5 European prospective CVD cohorts including 1416 cases and 1772 non-cases, as part of the MORGAM project. Both single-locus and haplotypes analyses were carried out to investigate the association of these SNPs with CVD.</p> <p>Results</p> <p>We did not find any significant differences in allele, genotype and haplotype frequencies between cases and non-cases for either of the two genes. Moreover, the search for interactions between SNPs located in different genes, including 5 <it>IL18 </it>SNPs previously studied in the MORGAM project, and between SNPs and environmental factors remained unfruitful.</p> <p>Conclusion</p> <p>Our analysis suggests that the variability of <it>IL18R1 </it>and <it>IL18RAP </it>genes are unlikely to contribute to modulate the risk of CVD.</p
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