Hamza Kadiri | New York University (original) (raw)

Papers by Hamza Kadiri

Proceedings of the International Conference on Ground Improvement & Ground Control, 2012

ABSTRACT Lime treatment is an efficient way to stabilize soils. However, its efficiency is very l... more ABSTRACT Lime treatment is an efficient way to stabilize soils. However, its efficiency is very limited in sandy soil for which cement treatment is often more adapted. It is believed that very low clay content can be enough to drastically increase the properties of a sandy soil by lime treatment. Hence, adding a low quantity of clayey materials in addition to lime can make sand stabilization possible. In this context, this paper presents the preliminary results of an experimental program carried out on different sand-bentonite mixtures treated with lime and then compacted at normal optimum Proctor conditions. Lime-treated soils have been uniaxially compressed at different curing times (up to 56 days). The results show that the strength properties of lime-treated soils are considerably increased because of relatively low contents of bentonite added in pure sand. Also, beyond a given bentonite content, the soil strength starts to decrease when bentonite is further added. In parallel, a comparison is also made with the Proctor compaction curves. Starting from pure sand, the Proctor optimum density increases with the bentonite content, reaches a maximum density and then decreases with addition of clay.

ABSTRACT The nucleation mechanism of experimentally most commonly observed twinning in Mg crystal... more ABSTRACT The nucleation mechanism of experimentally most commonly observed twinning in Mg crystal initiating deformation process are studied using molecular dynamic simulation. We observed nucleation of radially growing 10-12 twinning under tensile loading in Mg rectangular wire system without artificial creation of an twinning. The twinning nucleation mechanism is very different from the conventional twinning mechanism in that the twin nucleates from a point source rather than the fault plane following the partial dislocation line in FCC crystal. The wire axis is normal to basal plane of Mg crystal. The tensile deformation in c-axis nucleates 10-12 twinning starting at the corner of square of cross section of the wire. The twin boundary is spherical at the beginning and become linear boundaries in 10-12 planes as time goes by.

RSC Adv., 2014

Synthesis of ultra-thin, well-aligned, monocrystalline, highly luminescent ZnO nanowires on polys... more Synthesis of ultra-thin, well-aligned, monocrystalline, highly luminescent ZnO nanowires on polystyrene beads as templates.

Bio tribune magazine, 2010

Résumé Introduction Les fibromatoses desmoïdes sont des tumeurs bénignes rares, localement agres... more Résumé Introduction Les fibromatoses desmoïdes sont des tumeurs bénignes rares, localement agressives, ayant tendance à récidiver mais ne disséminant pas à distance. Le diagnostic histologique peut être difficile. Un complément immunohistochimique est alors utile. Notre objectif a été d’étudier le profil immunohistochimique de ces tumeurs pour évaluer l’aide diagnostique que peut apporter cette technique. Matériels et méthodes 14 cas de fibromatoses extra-abdominales

Biomedical Engineering Research, 2014

Aim of the study: Immunohistochemical evaluation of WT1, E-cadherin, beta-catenin, EGFR and p53 o... more Aim of the study: Immunohistochemical evaluation of WT1, E-cadherin, beta-catenin, EGFR and p53 on Tissue MicroArray (TMA) of 43 Moroccan benign, borderline and invasive epithelial ovarian tumours. Materials and methods: All 43 cases were collected from the pathology department of the Institut National d'Oncologie in Rabat, Morocco, and comprised 34 carcinomas, 4 borderline serous and mucinous tumours and 5 benign tumours. Patients were between 20 and 74 years old with a mean age of 50 years. TMAs and the IHC study were supported by a grant from the IAAE (International Agency of Atomic Energy) and prepared in the pathology department of Columbia University in New York. 3 cores were selected from each case, and the peroxydase-anti peroxydase technique was used for the study of the different markers (DAKO Cytovision, Carpinteria CA). Results: 23.25% of the cases (10/43) were WT1 positive and were serous tumours (including one poorly differentiated adenocarcinoma). 72% of the cases (31/43) showed reduced (19/43) or no (12/43) membranous expression of E-cadherin, and all the tumours showed reduced membranous expression with cytoplasmic expression (5/43) or no expression (38/43) of beta-catenin. p53 overexpression (13/43) was exclusively observed in 58% (11/19) of the serous carcinomas and 2/3 poorly to moderately differentiated adenocarcinomas, of which 9/13 were EGFR + and 6/13 were E-cadherin +. 70% of the cases (30/43) showed EGFR membrane staining, and 2 cases were not interpretable. Conclusion: TMA is a feasible tool to study a large number of cases allowing comparative analysis of the expression of different biomarkers. To our knowledge, this is the first study of 5 biomarkers to be done on TMAs from 43 moroccan benign, borderline and invasive epithelial ovarian tumour samples. This would allow for larger studies with the aim of analyzing the significance of these biological markers and their impact in clinical trials.

International Journal of Number Theory, 2012

Let K be a number field, nK be its degree, and dK be the absolute value of its discriminant. We p... more Let K be a number field, nK be its degree, and dK be the absolute value of its discriminant. We prove that, if dK is sufficiently large, then the Dedekind zeta function ζK(s) has no zeros in the region: [Formula: see text], [Formula: see text], where log M = 12.55 log dK + 9.69nK log |ℑ𝔪 s| + 3.03 nK + 58.63. Moreover, it has at most one zero in the region:[Formula: see text], [Formula: see text]. This zero if it exists is simple and is real. This argument also improves a result of Stark by a factor of 2: ζK(s) has at most one zero in the region [Formula: see text], [Formula: see text].

Journal of Biomedical Science and Engineering, 2013

Aim of the study: Immunohistochemical evaluation of hormone receptors, Her2/neu, CK5/6, E-cadheri... more Aim of the study: Immunohistochemical evaluation of hormone receptors, Her2/neu, CK5/6, E-cadherin, beta-catenin, p53 and PTEN on Tissue Micro Array (TMA) of 46 Moroccan invasive breast carcinomas. Materials and Methods: The cases comprised 40 invasive ductal carcinomas, 4 invasive lobular carcinomas, 1 mixed carcinoma and 1 invasive colloid carcinoma. TMA paraffin blocs were prepared with the Beecher manual arrayer and immunostaining was performed using standard immunoperoxidase techniques. Results: 58.69% of the cases were ER positive. 43.18% (19/44) were triple negative breast cancers (TNBC) of which 15.78% (3/19) were of the basal phenotype expressing CK5/6. On the other hand, 72.22% (13/18) of the TNBC cases were IDC grade 3. Of the 18 IDC grade 3, 22.22% (4/18) were CK5/6 positive. 41.30% and 10.86% of the cases showed reduced expression of E-cadherin and beta-catenin respectively. Beta-catenin nuclear and cytoplasmic staining was noted in 20% and 97.82% respectively. p53 was overexpressed in 10.86% of the cases whereas PTEN loss or reduced expression was noted in 86.95% of the cases. Conclusion: The aim of our study was to introduce TMA technique in our hospital which is considered a reference institution for cancer in Morocco. Although no statistical study was performed to look for any significance of the results obtained, we found good correlation with some of the data in the literature. To determine the molecular characteristics, if any, of the Moroccan patient, larger multidisciplinary and prospective studies would be interesting in the aim to personalize therapeutic decisions.

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Mathematics of Computation, 2014

In this article we provide new explicit Chebyshev's bounds for the prime counting function ψ(x). ... more In this article we provide new explicit Chebyshev's bounds for the prime counting function ψ(x). The proof relies on two new arguments: smoothing the prime counting function which allows to generalize the previous approaches, and a new explicit zero density estimate for the zeros of the Riemann zeta function.

Beilstein Journal of Nanotechnology, 2014

Our aim was to elaborate a novel method for fully controllable large-scale nanopatterning. We inv... more Our aim was to elaborate a novel method for fully controllable large-scale nanopatterning. We investigated the influence of the surface topology, i.e., a pre-pattern of hydrogen silsesquioxane (HSQ) posts, on the self-organization of polystyrene beads (PS) dispersed over a large surface. Depending on the post size and spacing, long-range ordering of self-organized polystyrene beads is observed wherein guide posts were used leading to single crystal structure. Topology assisted self-organization has proved to be one of the solutions to obtain large-scale ordering. Besides post size and spacing, the colloidal concentration and the nature of solvent were found to have a significant effect on the self-organization of the PS beads. Scanning electron microscope and associated Fourier transform analysis were used to characterize the morphology of the ordered surfaces. Finally, the production of silicon molds is demonstrated by using the beads as a template for dry etching.

Journal De Physique, 1988

Amorphous ribbons with general formula Fel-y-,Cr, (PCSi), , (0.004 < y < 0.12), (0.08 < z < 0.22)... more Amorphous ribbons with general formula Fel-y-,Cr, (PCSi), , (0.004 < y < 0.12), (0.08 < z < 0.22) have been studied. Cr seems responsible for the decrease of saturation moment, Curie temperature and mean hyperline field. The hyperline field distribution exhibits some particular structure when Cr content is increased. A low Avrami exponent has been found from crystallization studies.

These de doctorat, Université Lille I, 2002

Physica B: Condensed Matter, 2002

Random anisotropy and spin-wave studies on amorphous Fe 100ÀyÀz Cr y (PCSi) z , (4pyp11, 19pzp22)... more Random anisotropy and spin-wave studies on amorphous Fe 100ÀyÀz Cr y (PCSi) z , (4pyp11, 19pzp22), have been performed. The behavior, as a function of temperature, of the magnetization, anisotropy and exchange parameters has been studied. The spin-wave stiffness constant and the average mean-square range, /r 2 S, of the exchange interaction have been evaluated, and the results obtained have been discussed.

Mathematics of Computation, 2008

For any > 0 and any non-exceptional modulus q ≥ 3, we prove that, for x large enough (x ≥ α log 2... more For any > 0 and any non-exceptional modulus q ≥ 3, we prove that, for x large enough (x ≥ α log 2 q), the interval e x , e x+ contains a prime p in any of the arithmetic progressions modulo q. We apply this result to establish that every integer n larger than exp(71 000) is a sum of seven cubes.

Journal of Number Theory, 2012

Journal of Number Theory, 2003

We prove that every interval xð1 À D À1 Þ; x contains a prime number with D ¼ 28 314 000 and prov... more We prove that every interval xð1 À D À1 Þ; x contains a prime number with D ¼ 28 314 000 and provided xX10 726 905 041: The proof combines analytical, sieve and algorithmical methods.

Biological Trace Element Research, 2007

The effects of chronic exposure to cadmium (Cd) on some selected biochemical parameters, as well ... more The effects of chronic exposure to cadmium (Cd) on some selected biochemical parameters, as well as the possible protective role of aqueous extracts of Hibiscus sabdariffa L petal were studied in 12-wk-old male Wistar albino rats. Exposure to Cd caused a significant increase in plasma l-alanine aminotransferases (ALT) only but with a corresponding decrease in liver l-alanine and l-aspartate aminotransferases

Hyperfine Interactions, 1989

Gastroentérologie Clinique et Biologique, 2009

Introduction Malgre leur relative rarete les lymphomes non hodgkiniens (LNH) a grandes cellules p... more Introduction Malgre leur relative rarete les lymphomes non hodgkiniens (LNH) a grandes cellules primitifs de l’estomac localises suscitent un interet constant dans la litterature et leur prise en charge optimale reste controversee. En particulier, la place de la gastrectomie doit etre clarifiee. L’objectif de ce travail est de comparer une exerese chirurgicale suivi d’une polychimiotherapie a une polychimiotherapie seule. Patients et Methodes Nous avons revu facon retrospective tous les dossiers cliniques des patients presentant un LNH primitif gastrique et pris en charge a l’institut national d’oncologie de Rabat au Maroc entre janvier 1999 et decembre 2006. Les patients eligibles devaient avoir (a) un lymphome a grandes cellules primitif gastrique, (b) des informations cliniques completes et une preuve anatomopathologique, (c) un stade localise I et II selon AnnArbor modifie par Musshoff [1], (d) ayant recu soit une resection chirurgicale suivi d’une polychimiotherapie adjuvante a base d’anthracycline dans le groupe I soit une polychimiotherapie seule a base d’anthracycline dans le groupe II. Resultats Nous avons colliges respectivement 30 patients dans le groupe I et 52 patients dans le groupe II. Les caracteristiques cliniques et pathologiques etaient similaires dans les deux groupes en dehors de l’atteinte ganglionnaire locoregionale qui etaient plus importantes dans le groupe II (P Conclusion Les resultats de cette etude retrospective suggerent que l’exerese chirurgicale suivi d’une polychimiotherapie n’ameliore pas les resultats therapeutiques du LNH gastrique a grandes cellules localise par rapport a une polychimiotherapie seule et que celle-ci peut constituer une alternative therapeutique raisonnable a proposer aux malades qui gardent une qualite de vie meilleure mais ceci doit etre verifier dans une etude randomisee prospective a large effectif qui devrait evaluer aussi l’apport du Rituximab dans cette localisation lymphomateuse.

Computational Materials Science, 2013

ABSTRACT In the last few decades, the phase field method has shown tremendous capabilities of pre... more ABSTRACT In the last few decades, the phase field method has shown tremendous capabilities of predicting microstructure evolutions at the mesoscale scale. This method was widely used for modeling martensitic phase transformation, where the displacive character was a challenging problem for the counterpart sharp interface approach. Martensitic phase transformation, which is an invariant plane stress twinning, drives a myriad of phase transition phenomena of paramount importance to many structural applications. This article provides a literature review of the past phase field modeling studies used to capture the formation and growth of martensite.

Journal africain du …, 2011

Page 1. ORIGINAL ARTICLE / ARTICLE ORIGINAL Soft tissue sarcomas and therapeutic management: is t... more Page 1. ORIGINAL ARTICLE / ARTICLE ORIGINAL Soft tissue sarcomas and therapeutic management: is there a place for systemic chemotherapy in an adjuvant setting? Gestion thérapeutique des sarcomes de parties molles : existe-il une place à la chimiothérapie adjuvante ? ...