Study of dependence between two types of most abundant natural clays in Bejaad province (Central Morocco) using a statistical approach

This work proposes the studying of characterization analysis of two natural Moroccan clays (RC and GC) in the same location from Bejaad (Province of Khouribga, Morocco) and to know the relationship dependence between them. The values obtained during the determination of a few parameters (density, pH, conductivity, dry matter - moisture content, organic matter-mineral matter) show that the two materials RC and GC studied have the same physical-chemical properties. The all characterization of the two clays was carried out by XRD, XRF, FTIR, SEM/EDX and TGA. The results obtained show that the two materials have very irregular and microporous structures, a heterogeneity of the pore forms and they are contain a mixture of Kaolinite, Illite, Quartz, Calcite, and Dolomite, with the presence of Hematite only in clay RC. On the other hand, The statistical approach applied to determine the dependence relationship between the two clays was based on two tests: Student's t-test (Comparison of two means for physical-chemical parameters) and Pearson's test (contingency table for XRF analysis) in order to prove that the two materials studied are the same chemical and physical-chemical characteristics

The influence of layer defect in the Ferroelectric films

Using the modified transverse Ising model, and the effective field theory based on the probability distribution technique, the phase transition temperature, the polarization and susceptibility for ferroelectric thin films with structural defects are studied. It is shown that the defect layers in ferroelectric thin films can induce strong increase or decrease of the critical temperature of ferroelectric phase transition due to different exchange interactions in the defect layers. The obtained results are in qualitative agreement with experimental data for thin ferroelectric film with different thickness.Using the modified transverse Ising model, and the effective field theory based on the probability distribution technique, the phase transition temperature, the polarization and susceptibility for ferroelectric thin films with structural defects are studied. It is shown that the defect layers in ferroelectric thin films can induce strong increase or decrease of the critical temperature of ferroelectric phase transition due to different exchange interactions in the defect layers. The obtained results are in qualitative agreement with experimental data for thin ferroelectric film with different thickness

ZnTe/CdSe type-II core/shell spherical quantum dot under an external electric field

International audienceWe have investigated in the framework of the envelope function approximation and taking into account the dependence of the electron effective mass on radius the energy of an electron inside a ZnTe/CdSe core/shell spherical quantum dot. In order to make the problem more realistic, we describe the conduction band-edge alignment between core and shell materials by a finite height barrier. By applying the Ritz variational principle the effect of the electric field on the electronic states was also examined. Our numerical results show the opportunity to control the energy states position of the charge carriers inside our core/shell nanostructures by controlling the size (core radius, shell thickness) of the nanostructure and the strength of the external electric field

Coronavirus and Nutrition: Approach for Boosting Immune System in Morocco

The Covid-19 pandemic is a pandemic of an emerging infectious disease, the 2019 coronavirus disease Covid-19, caused by the SARS-CoV-2 coronavirus. The essential protective measures recommended by WHO (2020) to limit the spread of the Coronavirus (Covid-19) limited in the suppression of travel, quarantine and containment. In the first part of this review, we will examine the origin of the coronavirus, the modes of spread and their adverse effects on human health. We will include in our analysis the nutritional importance of the different approaches based on mechanisms to boost the immune system and therefore good viral defense. The immune system helps protect the host against environmental agents such as pathogenic microorganisms (bacteria, fungi and viruses), thus preserving the integrity of the organism. To preserve the defense mechanisms of the organisms, an adequate nutritional state must be maintained with adequate intakes of calories, vitamins, minerals and water which must be continuously provided by a healthy diet. In addition, it is necessary to have nutritional information that will help boost the immune system of people in the fight against Covid-19, nutritional diagnosis and early nutritional management of affected patients must be integrated into the overall therapeutic strategy. Several clinical data have shown that micronutrients like vitamins, including vitamins A, C, D, E, B12, B6 and folic acid; trace elements like iron, zinc, copper, magnesium, selenium, and omega-3 fatty acids like docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) play a major role in supporting the immune system

Morphological and chemical characterization of carob pulps collected from four moroccan regions

The present research is included in a strategy of conservation and management of genetic resources for Carob tree (Ceratonia Siliqua L.) in Morocco. It has as one of its objectives, the evaluation of the morphological and chemical characteristics of four Moroccan ecotypes of carob pulps. The study related to morphological characterization reveals that there was a significant difference between the four populations from Meknes, Fez, Khemisset and Marrakech collected in 2018 and 2019. The lipid profile of carob pulp extracts analyzed by GC-MS is constituted of fatty acids, hydrocarbons, non-oxygenated compounds, sterols and tocopherols. The concentration of these compounds varies according to the population and year of collection. According to the results, the fatty acid contents are relatively high in 2019 with the dominance of palmitic acid. Additionally, our study approved the dominance of 1-Hexacosene, Tetracosane, Heptadecane. 1-iodo Hexadecane, 1-chloro Octadecane and 1, 54-dibromo Tetrapentacontane. Furthermore, it is noted that Stigmasterol, gamma-Sitosterol, beta-Sitosterol, alpha-Tocospiro A, alpha-Tocospiro B and Vitamin E are present in the samples. Moreover, the hierarchical analysis based on the results of the morphological and chromatographic characterization of the four populations’ pulps identify three groups. The first group included populations P3 and P4 respectively from Marrakech and Khemisset. The second group presented by the population P1 from Meknes. The population P2 from Fez constituted the third group

Impact of composts prepared from olive waste on the growth and production parameters of some fruit trees

In agriculture, the use of organic amendments allows a better sustainability and productivity of the crop by improving the quality and structure of the soil, due to their richness in organic matter and nutrients such as phosphorus, nitrogen, potassium, etc. This study aims to evaluate the effect of two composts of different compositions on the growth and yield of three types of trees: peach, pear and orange. The experimental design used is a randomized block with three replications. The treatment of trees was carried out by four types of amendments which were composts with olive waste (OW), olive mill wastewater (OMW), manure (M) and NPK fertilizer (F) of type 10-15-12. Their fertilizing power was evaluated by monitoring the morphological parameters of plant growth: height, trunk diameter, number of branches, and those of production including size, weight of fruit and yield. The obtained outcomes reveal that the two composts have a very highly significant effect on the investigated parameters. The production was recorded only in peach trees with a total yield of 31.5 t/ha; 25.5 t/ha; 22.5 t/ha; 18.5 t/ha, respectively for OW, OMW, F and M

What effects does an organic amendment to olive waste have on the soil and crop yield?

Intensive agriculture or phenomena such as pollution, compaction, and/or erosion lead to a decrease in the amounts of organic matter of soils; thus, causing a decrease in their fertility. The use of an organic amendment in agriculture could combat soil degradation. In this sense, two organic amendments with olives waste (OW) and olive mill wastewater (OMW) have been manufactured.  The objective of this work is to examine the capacity of these amendments to improve soil quality in comparison with manure (M). Three types of soil were tested: the first has been amended for two years with a compost of similar composition (S1), the second not amended (S2), and the third corresponds to an agricultural soil that is amended with chemical fertilizer (S3). All the trials were carried out on two vegetable gardens: potato and radish. The ANOVA shows that the amendment effect was highly significant on all the physicochemical parameters studied except humidity. In conclusion, this product could be an alternative to chemical fertilizers and considered as a perennial solution adapted to the context of sustainable development to the recovery of olive waste

Agronomic valorization of the composts with olive waste

In the Mediterranean countries, olive waste, a co-product of the olive oil trituration process, presents a serious environmental problem because of their polyphenol charge, given the quantities rejected each year. In previous works, this waste has been co-composted with other substrates and has been transformed into non-phytotoxic substances in conformity with the French standard NFU44-051 due to their composition in nutritional elements like soluble sugars, proteins and mineral elements. This study examines the efficacy of these substances on radish and potato crops. To do this, seeds were sown on the plot. For each crop, 4 plots were planned: land amended with manure (M), NPK fertilizer (F), the vegetable water substance (VW) and the olive-pomace substance (OP) in addition to the vegetable water. The first three substances served as controls. A statistical study of correlation between the latter and those that characterize the soil after amendment was carried out.  The obtained results showed that there are two strong correlations between pH, organic matter, dry matter and soil moisture amended by the OW compost and, on the one hand, the morphological growth parameters of the two crops and, on the other hand, the parameters of their production

Magnetic properties in ferroelectric superlattices described by a transverse spin-1/2 Ising model

The temperature dependence of the longitudinal magnetization as well as the longitudinal susceptibility of a ferroelectric superlattice described by a transverse spin-1/2 Ising model are studied using the effective field theory with a probability distribution technique that accounts for the self-spin correlations. When the slab thicknesses are larger, the temperature dependence of the magnetization shows a steplike structure. The susceptibility becomes infinite at the critical temperature T-c and shows a finite peak corresponding to the rapid decrease in the magnetization near the bulk critical temperature of slab B. The height of the finite peak decreases with the decrease in the slab thicknesses. When they become so thin that the magnetization profiles are predominantly controlled by the interface, the finite peak in the susceptibility as well as the steps in magnetization disappear. (C) 2002 Elsevier Science B.V. All rights reserved