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1.
In this paper we use real analysis techniques to establish a new real Paley-Wiener theorems for the Fourier-Bessel transform associated with the Weinstein operator. More precisely we characterize the C ∞-functions whose image under the Fourier-Bessel transform are functions with compact support through an L p growth condition, p ∈ [1, +∞] and we give another version of the real Paley-Wiener theorem for L 2-functions. 相似文献
2.
Johannes Ruck Yamen Othmani Tanja Lube Iyas Khader Andreas Kailer Thomas Böhlke 《PAMM》2015,15(1):147-148
Modeling the damage of brittle materials is of great importance considering a variety of structural components. Prominent examples are high strength engineering ceramics. The present work is concerned with silicon nitride, a material with increasing relevance in industrial applications. In the sense of a hierarchical model structure, effective properties of micromechanical simulations were applied to macroscopic, phenomenological damage models for monotonous and cyclic loading. In the following, both models are introduced and the application of the cyclic damage model to a four point bending test is discussed. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
3.
Hanen Khadhraoui Abdelhak Othmani Abdessalem Kouki Mouldi Zouaoui 《Electroanalysis》2021,33(1):152-159
In this work we report an easy and efficient way to fabricate nanostructured cobalt oxide (Co3O4) thin films as a non-enzymatic sensor for H2O2 detection. Co3O4 thin films were grown on ITO glass substrates via the sol-gel method and characterized with several techniques including X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and optical absorbance. The Co3O4 thin films’ performance regarding hydrogen peroxide detection was studied in a 0.1 M NaOH solution using two techniques, cyclic voltammetry (CV) and amperometry. The films exhibited a high sensitivity of 1450 μA.mM−1.cm−2, a wide linear range from 0.05 μM to 1.1 mM, and a very low detection limit of 18 nM. Likewise, the Co3O4 thin films produced showed an exceptional stability and a high selectivity. 相似文献
4.
H. Othmani R. Ben Said N. Terzi N.-E. Jaidane M. Mogren Al Mogren A. Elmarghany 《Molecular physics》2019,117(13):1589-1603
ABSTRACTIn many cases, 5-fluorouracil (5-FU) is the first-line drug used in combined chemotherapy and radiotherapy treatments due to its radio-sensitization properties. It could participate in a tautomerization process similar to that of uracil, where 5-FU may couple to adenine in DNA. At present, we performed structural and spectroscopic studies using quantum chemical methods of neutral and cationic isolated 5-FU anticarcinogenic drug tautomers, either interacting with a water molecule or embedded into an implicit water solvent. Also, we determined the stationary points (both stable structures and transition states) on their ground potential energy surfaces playing a role during the tautomerization processes. For neutral and ionic species in the gas phase and in solvent, the ordering of the tautomers is found to be the same, where the di-keto form of 5-FU is the most stable structure, followed by the keto–enol and di-enol structural forms. The energy barriers for tautomerization are strongly reduced in solvent (< 0.5?eV) compared to isolated species (~2?eV). The patterns of their lowest electronic states are also computed. Our data may help for the identification of these species in vivo and in the laboratory. 相似文献
5.
Uncertainty Principles for the Generalized Fourier Transform Associated with Spherical Mean Operator
The aim of this paper is to establish an extension of qualitative and quantitative uncertainty principles for the Fourier transform connected with the spherical mean operator. 相似文献
6.
Yamen Othmani Laurent Delannay Issam Doghri 《International Journal of Solids and Structures》2011,48(24):3326-3335
Starting from Eshelby’s solution of the equivalent inclusion problem, an approximate solution is proposed in order to model interface debonding of a spherical inhomogeneity isolated in a uniform matrix. Both phases are linear elastic but the interface traction-separation law is non-linear. A semi-analytical incremental model is developed which is suitable for any type of loading. For computational efficiency, the model relies on two simplifying assumptions: (i) the eigenstrain is uniform inside the inhomogeneity and (ii) the interface compliance is averaged over inhomogeneity’s surface when computing the average strain within the inhomogeneity. An extensive parametric study is conducted for three loading modes and 144 combinations of non-dimensional parameters. The predictions are assessed against full-field finite element solutions based on two error measures of the mean stress field inside the inhomogeneity. The results show that the mean error value is acceptable in all cases and indicate the parameter ranges for which the model is most accurate. 相似文献
7.
8.
Chokri Othmani Mohamed Taktak Ali Zein Taissir Hentati Tamer Elnady Tahar Fakhfakh Mohamed Haddar 《Applied Acoustics》2016
Agricultural residues present a challenge to the environment. Most of these residues are burnt in the farm causing several pollution hazards to the environment. There has been a lot of interest to find applications for these residues instead of burning them. One application can be using them as acoustic materials. This paper presents the results of the evaluation of the acoustic performance of the sugarcane wastes based material. This evaluation is made by measuring two acoustic parameters: the flow resistivity and the acoustic absorption coefficient. The manufacturing of multiple samples with different physical properties (sample thickness, fiber size, and resin content) allowed evaluating the effect of each property on the acoustical performance of the studied material. A comparison between experimental and theoretical results showed good agreement. 相似文献
9.
In this work, recursive formulas facilitating the computation of very complex tensor integrals over the unit circle, are obtained by making use of the divergence theorem and mathematical induction. Using these formulas, the integrals over the unit circle of polynomials with any high degree are easily computed. 相似文献
10.
Jesse O. Omamogho Elaine M. Stack Apichai Santalad Supalax Srijaranai Jeremy D. Glennon Helen Yamen Klaus Albert 《Analytical and bioanalytical chemistry》2010,397(6):2513-2524
This study describes the use of stationary phases with polar functionality suitable for the chemical analysis of carbamates
pesticides and comparing with conventional alkyl C8 and C18 phases. The emphasis of this study was to compare the selectivity
and retention of the pesticides on different stationary phases, bonded onto 1.7 μm partially porous silica particles under
isocratic separation condition. Four stationary phases including: phenylaminopropyl (PAP) phase, bidentate propylurea-C18
(BPUC18), C8 and C18, were successfully bonded on the partially porous silica spheres as evidenced by 29Si and 13C solid-state NMR analysis. The phenylaminopropyl phase exhibited smaller retentivity and enhanced selectivity compared to
the alkyl C8 phase; the analysis time to run separation of the six carbamate pesticides (i.e., methomyl, propoxur, carbofuran,
carbaryl, isoprocarb, and promecarb) on the PAP phase was threefold faster than alkyl C8 phase. In a similar manner, the BPUC18 phase shows similar selectivity to that of the PAP phase, but with longer retentivity; although the BPUC18 phase is characterized with a lesser degree of retentivity for the carbamate pesticides than the conventional alkyl C18 phase.
We propose that π–π and weak polar interactions between the carbamate pesticides and the PAP phase dominates the separation
mechanism and providing a superior selectivity; faster separation time was also achieved as a result of smaller retentivity.
Whereas the C8 and C18 bonded phases exhibits only hydrophobic interactions with the pesticides, leading to larger retentivity.
The BPUC18 phase is shown to interact via polar–polar interactions in addition to hydrophobic interactions with the pesticides, providing
similar selectivity with the PAP phase but with larger retentivity. 相似文献