Effect of shear stresses on the deflection and optimal configuration of a rectangular FGM structure

Ayoub El Amrani,Hafid Mataich,Jaouad El-Mekkaoui,Bouchta El Amrani Techno-Press 2023 Coupled systems mechanics Vol.12 No.4

This paper presents a static study of a rectangular functional graded material (FGM) plate, simply supported on its four edges, adopting a refined higher order theory that looks for, only,four unknowns,without taking into account any corrective factor of the deformation energy with the satisfaction of the zero shear stress conditions on the upper and lower faces of the plate. We will have determined the contribution of these stresses in the transverse deflection of the plate, as well as their effects on the axial stress within the interfaces between the layers(to avoid any problem of imperfections such as delamination) and on the top and bottom edges of the plate in order to take into account the fatigue phenomenon when choosing the distribution law of the properties used during the design of the plate. A numerical statement, in percentage, of the contribution of the shear effect is made in order to show the reliability of the adopted theory. We will also have demonstrated the need to add the shear effect when the aspect ratio is small or large. Code routines are programmed to obtain numerical results illustrating the validity of the model proposed in the theory compared to those available in the literature.

Lack of Association between CYP1A1 M2 and M4 Polymorphisms and Breast Carcinoma in Jordanian Women: a Case-Control Study

Amrani, Iman,Bulatova, Nailya,Awidi, Abdalla,Yousef, Al-Motassem,Melhem, Jamal Masad,Al-Masri, Mahmoud,Tahoun, Laila Abu Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.1

Background: CYP1A1 is a candidate gene for low-penetrance breast cancer susceptibility, as it plays an important role in the metabolism of carcinogens and estrogens. Purpose: The objective of this study was to assess the association between M2 (A2455G, Ile462Val) and M4 (C2453A, Thr461Asn) polymorphisms in CYP1A1 and breast cancer risk among Jordanian women and in subgroups stratified by menopausal status and smoking history. Materials and Methods: Blood samples were collected from 112 breast cancer female patients and 115 age-matched controls who underwent breast cancer screening with imaging and showed negative results (BI-RADS I or BI-RADS II). Genotyping was performed using the PCR-RFLP technique. Results: No statistically significant overall association was found between breast cancer risk and CYP1A1 M2 genotypes (p= 0.55; OR = 0.77; 95% CI= 0.32 - 1.83) nor with the M4 polymorphism (p= 0.95; OR= 0.95; 95% CI= 0.51 - 1.88). Analysis of subgroups defined by menopausal status or smoking history also revealed no association with these polymorphisms. Furthermore, the four identified haplotypes (AC; AA; GC and GA) were equally distributed among cases and controls, and haplotype analysis showed a strong linkage disequilibrium of both studied loci in either cases or controls (D'=1). Conclusions: Based on the study results, CYP1A1 M2 and M4 polymorphisms do not seem to play a major role in breast cancer risk among Jordanian females.

Protein Kinase and HDAC Inhibitors from the Endophytic Fungus <i>Epicoccum nigrum</i>

El Amrani, Mustapha,Lai, Daowan,Debbab, Abdessamad,Aly, Amal H.,Siems, Karsten,Seidel, Carole,Schnekenburger, Michael,Gaigneaux, Anthoula,Diederich, Marc,Feger, Daniel,Lin, Wenhan,Proksch, Peter American Chemical Society and American Society of 2014 Journal of natural products Vol.77 No.1

<P>A chemical investigation of the endophytic fungus <I>Epicoccum nigrum</I> isolated from leaves of <I>Mentha suaveolens</I> collected in Morocco resulted in the isolation of five new polyketides, epicocconigrones A and B (<B>1</B> and <B>2</B>), 3-methoxyepicoccone B (<B>3</B>), 3-methoxyepicoccone (<B>4</B>), and 2,3,4-trihydroxy-6-(methoxymethyl)-5-methylbenzaldehyde (<B>5</B>), together with five known compounds (<B>6</B>–<B>10</B>). The structures of the new compounds were unambiguously determined by extensive analysis of the 1D and 2D NMR and mass spectroscopic data. Compounds <B>1</B> and <B>10</B> showed potent inhibition of at least 15 protein kinases with IC<SUB>50</SUB> values ranging from 0.07 to 9.00 μM. Moreover, compounds <B>1</B> and <B>10</B> inhibited histone deacetylase (HDAC) activities with IC<SUB>50</SUB> values of 9.8 and 14.2 μM, respectively. A preliminary structure–activity relationship is discussed. Interestingly, compounds <B>1</B> and <B>10</B> exert mainly cytostatic effects in human lymphoma RAJI and U-937 cell lines.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jnprdf/2014/jnprdf.2014.77.issue-1/np4005745/production/images/medium/np-2013-005745_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/np4005745'>ACS Electronic Supporting Info</A></P>

Investigation of rapid thermal oxide/ silicon nitride passivation stack of nþ emitter

A. El Amrani,R. Si Kaddour,M. Maoudj,A. El Kechai,S. Mezghiche 한국물리학회 2015 Current Applied Physics Vol.15 No.12

To anticipate the initial phosphorus diffusion parameters of silicon solar cells process fabrication, we report in this paper an overview of our experiments on silicon nþ-emitters passivation by means of rapid thermal silicon oxide/silicon nitride stack. The process-induced changes have been evaluated and explained.We found that 900 C and 80 s were the appropriate process parameters to grow 10 nm silicon oxide. Investigation of the effect of this oxidation on nþ multicrystalline silicon emitters revealed a large decrease (more than 25%) of the sheet resistance and around 12% increase of the junction depth. The experiments also revealed that the passivation effect of the optimal silicon oxide/silicon nitride stack is efficient only for higher emitter quality. In addition, we found that this stack reduces the surface reflection more than the optimal single silicon nitride layer.

Analysis of the thermal instability of laminated composite plates

H. Mataich,A. El Amrani,B. El Amrani Techno-Press 2024 Coupled systems mechanics Vol.13 No.2

In this paper, we will analyse the thermo-elastic behavior of the plate element of a structure arranged in a climatically aggressive environment (extreme temperature), we use a refined four-variable thick plate theory to take the shear effect into consideration, the proposed theory less computationally expensive and more accurate so that it incorporates the shear effect into the formulation. The plate is assumed to be simply supported on its four edges, so exact (closed-form) solutions are found according to the Navier expansion, and the governing stability equations and associated boundary conditions of the problem are obtained via the virtual works principle. The plate studied ismade of laminated composite materials, so a parametric study is needed to see the effect of different types of parameters and coupling on the critical temperature value causing thermo-elastic instability of the plate and also on the natural frequency of free vibration, as well as for other parameters such as anisotropy, slenderness and aspect ratio of the plate and finally the lamination angle. Numerical results are obtained for specially orthotropic and antisymmetrical plates and are compared with those obtained by othertheoriesin the literature to validate the analysis approach used.

EXPLORING CUSTOMER EXPERIENCE WITH TABLETS IN M-COMMERCE: THE CASE OF WINE AND LUXURY BRANDS

PELET Jean-Eric,LECAT Benoît,El Amrani Redouane,Papadopoulou Panagiota 글로벌지식마케팅경영학회 2015 Global Fashion Management Conference Vol.2015 No.06

Tablets and the omnipresent mobile environment create opportunities and challenges for m-commerce (mobile commerce) vendors, seeking to increase their profits. Understanding factors that affect that consumer behavior, positively and negatively, in tablets is essential for vendors in order to provide a fruitful m-commerce customer experience. The objective of this paper is to facilitate the understanding of consumers’ perceptions and behavior in m-commerce and social media on tablets and explore the potential of tablets for m-commerce purposes. The paper reports the findings of two exploratory research studies on wine and luxury goods. The first study examines consumer perceptions of the use of tablets and social media, in the context of m-commerce of wine. The second study relates to selling of luxury goods through the Internet. The results of our qualitative analysis show that user experience and design aspects, such as ease-of-use, are important factors for tablet adoption and use for m-commerce and social media. Adapting web content to tablets is, therefore, critical to enable effective m-commerce on this popular device. Business opportunities enabled by tablets and social media in m-commerce and how these can be leveraged in the wine and the wider luxury goods context are discussed.

Equilibrium modeling for adsorption of NO₃^- from aqueous solution on activated carbon produced from pomegranate peel

Rouabeh, I.,Amrani, M. Techno-Press 2012 Advances in environmental research Vol.1 No.2

Nitrate removal from aqueous solution was investigated using $ZnCl_2$ and phosphoric acid activated carbon developed from pomegranate peel with particle size 0.4 mm. Potassium nitrate solution was used in batch adsorption experiments for nitrate removal from water. The effects of activated carbon dosage, time of contact, and pH were studied. The equilibrium time was fond to be 45 min. Two theoretical adsorption isotherms namely Langmuir and Freundlich were used to describe the experimental results. The Langmuir fit the isotherm with the theoretical adsorption capacity ($q_t$) was fond 78.125 mg g-1. Adsorption kinetics data were modeled using the pseudo-first, pseudo-second order, and intraparticle diffusion models. The results indicate that the second-order model best describes adsorption kinetic data. Results show activated carbon produced from pomegranate is effective for removal of nitrate from aqueous solution.

A NOTE ON DISCRETE SEMIGROUPS OF BOUNDED LINEAR OPERATORS ON NON-ARCHIMEDEAN BANACH SPACES

Blali, Aziz,Amrani, Abdelkhalek El,Ettayb, Jawad Korean Mathematical Society 2022 대한수학회논문집 Vol.37 No.2

Let A ∈ B(X) be a spectral operator on a non-archimedean Banach space over an algebraically closed field. In this note, we give a necessary and sufficient condition on the resolvent of A so that the discrete semigroup consisting of powers of A is uniformly-bounded.

Optimizing the Computing of Pairing with Miller’s Algorithm

Siham Ezzouak,Mohammed El Amrani,Abdelmalek Azizi 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.4

Elemental chlorine-free bleaching halfa pulp

Baya Bouiri,Moussa Amrani 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.4

Halfa, also known as Stipa tenacissima, is grown in North Africa and south Spain. Due to its short fiber length, paper of halfa remains bulk and takes the block letters well. In this study halfa was evaluated for bleached pulp production. Two cellulose pulps with different chemical compositions were pulped by conventional Kraft process: one from the original halfa material and the other from halfa pretreated by diluted acid. The pulp produced from halfa pretreated by diluted acid was bleached by elemental chlorine-free sequences, DEPD and DEDP. Yield, Kappa number, brightness and a-cellulose contents of bleached and unbleached pulps were evaluated. The results show that during the chemical pulping process, treated halfa was easily cooked than that original halfa. Treated halfa pulp also showed very good bleaching, showing brightness level of 94.8% ISO, yield 93.6% and a-cellulose content 96.8% with DEDP bleaching sequence compared to 83.2% ISO brightness level, 92.8% yield and 95.1% a-cellulose content for bleached pulp with DEPD bleaching sequence. On the other hand, the physicomechanical properties of pulp were not notably reduced by the bleaching process. Breaking length, tear and burst index of paper sheets were acceptable. Therefore, this halfa material could be a worthwhile choice for cellulosic fiber supply.