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11.
A. Baïri E. Zarco-Pernia J.-M. García de María J.-G. Bauzin N. Alilat N. Laraqi F. Gutiérrez 《Heat and Mass Transfer》2011,47(5):589-595
In the present study Nu-Ra-α correlations are proposed to calculate the steady-state natural convection heat transfer taking place in 2D air-filled cavities
of parallelogrammic section. The thermal conditions and the dimensions of the enclosures permit to cover a large range of
Rayleigh numbers, 1.7 × 103 ≤ Ra ≤ 3.0 × 109, suitable for diverse engineering applications. The two active walls of the cavities are kept vertical and isothermal at
hot and cold temperatures T
h
and T
c
respectively. Separated by a horizontal distance H, they have the same height H and are connected by a closed adiabatic channel whose upper and lower walls can be inclined at an angle α with respect to the horizontal, varying between −60° to +60°. That gives rise to a conducting or insulating cavity, in the
convective sense of the term (diode cavity). A computational model based on the finite volume method is used to solve the
governing equations. The large number of treated configurations led to propose Nu-Ra-α correlations for large ranges of Ra and α which can be applied to many engineering areas. The results of this numerical study have been successfully compared with
calculated and measured available data. 相似文献
12.
Hamid Najib Najate Bensari-Zizi Guy Guelachvili Claude Alamichel 《Journal of Molecular Spectroscopy》1985,114(2):321-335
The rotational analysis of the ν2 + ν3 band, centered around 1912 cm?1, and of both components 2ν6±2 and 2ν60, centered about 1912 and 1904 cm?1, respectively, has been carried out from a Fourier transform spectrum having a resolution limit of 0.005 cm?1. A standard deviation of about 0.001 cm?1 was obtained for about 750 lines of the unperturbed 2ν6±2 component for both isotopic species. The ν2 + ν3 band, stronger than 2ν6±2, is perturbed by two resonances: a Coriolis resonance with the very weak ν3 + ν5 band, no line of which has been observed, and an anharmonic resonance with 2ν60, only four K subbands of which have been observed. For both isotopic species, a standard deviation of about 0.002 cm?1 has been obtained for about 750 lines of ν2 + ν3 and 2ν60. 相似文献
13.
Let $$f : A \rightarrow B$$ be a ring homomorphism and J be an ideal of B. In this paper, we give a characterization of zero divisors of the amalgamation which is a generalization of Maimani’s and Yassemi’s work (see Maimani and Yassemi in J Pure Appl Algebra 212(1):168–174, 2008). Furthermore, we investigate the transfer of Prüfer domain concept to commutative rings with zero divisors in the amalgamation of A with B along J with respect to f (denoted by $$A\bowtie ^fJ),$$ introduced and studied by D’Anna et al. (Commutative algebra and its applications, Walter de Gruyter, Berlin, 2009, J Pure Appl Algebra 214:1633–1641, 2010). Our results recover well known results on duplications. The main applications constist in the construction of new original classes of Prüfer rings that are not Gaussian and Prüfer rings with weak global dimension strictly greater than 1. 相似文献
14.
Najib Mahdou 《代数通讯》2013,41(3):1066-1074
In this work, we give a sufficient condition to resolve Costa's first conjecture for each positive integer n and d with n ≥ 4. Precisely, we show that if there exists a local ring (A, M) such that λ A (M) = n, and if there exists an (n + 2)-presented A-submodule of M m , where m is a positive integer (for instance, if M contains a regular element), then we may construct an example of (n + 4, d)-ring which is neither an (n + 3, d)-ring nor an (n + 4, d ? 1)-ring. Finally, we construct a local ring (B, M) such that λ B (M) = 0 (resp., λ B (M) = 1) and so we exhibit for each positive integer d, an example of a (4, d)-ring (resp., (5, d)-ring) which is neither a (4, d ? 1)-ring (resp., neither a (5, d ? 1)-ring) nor a (2, d′)-ring (resp., nor a (3, d′)-ring) for each positive integer d′. 相似文献
15.
Farid Rachidi Mutale-joan Chanda Redouane Benhima Mernissi Najib EL Abderahime Aasfar Laila Sbabou Arroussi Hicham EL 《Applied biochemistry and biotechnology》2019,188(1):225-240
Applied Biochemistry and Biotechnology - Microalgae are photosynthetic microorganisms that produce several bioactive molecules that have received considerable attention in scientific and industrial... 相似文献
16.
Bruno Coulomb Fabien Robert-Peillard Najib Ben Ali Gam Salwa Sadok Jean-Luc Boudenne 《Molecules (Basel, Switzerland)》2021,26(19)
This paper presents the development and the application of a multisyringe flow injection analysis system for the fluorimetric determination of the major heat-stable known allergen in shrimp, rPen a 1 (tropomyosin). This muscle protein, made up of 284 amino acids, is the main allergen in crustaceans and can be hydrolyzed by microwave in hydrochloric acid medium to produce glutamic acid, the major amino acid in the protein. Glutamic acid can then be quantified specifically by thermal conversion into pyroglutamic acid followed by chemical derivatization of the pyroglutamic acid formed by an analytical protocol based on an OPA-NAC reagent. Pyroglutamic acid can thus be quantified between 1 and 100 µM in less than 15 min with a detection limit of 1.3 µM. The method has been validated by measurements on real samples demonstrating that the response increases with the increase in the tropomyosin content or with the increase in the mass of the shrimp sample. 相似文献
17.
Being able to bind, select, and transport species is central to a number of fields, including medicine, materials, and environmental science. In particular, recognizing a specific species from one phase and transporting it across, or into another phase, has obvious applications in environ-mental science, for example, removal of unwanted or toxic materials from an aqueous or organic phase. In this paper, we describe an approach that uses a functionalized dendritic polymer to bind and transport a small anionic molecule across an organic phase (and between two aqueous phases). The design was based on encapsulation principles borrowed from nature, where anions are bound and transported by proteins that have specific sites within their globular ordered structures. For the work reported here, a globular dendritic polymer functionalized with an isophthalamide-based receptor was used to replace the protein structure and anion-binding site. Along with control experiments, the binding and transport properties of two functionalized HBPs were assessed using a Pressman U tube experiment. Both HBPs demonstrated an enhanced ability to bind and transport anions (when compared to the anion-binding site used in isolation). Furthermore, optimum binding and transport occurred when the smaller of the two HBPs were used. This supports our previous observations regarding the existence of a dense packed limit for HBPs. 相似文献
18.
Abdillah Sani Bin Mohd Najib Xiaobo Peng Ayako Hashimoto Shusaku Shoji Takayuki Iida Yunxing Bai Hideki Abe 《化学:亚洲杂志》2019,14(16):2802-2805
Mesoporous precious metals with abundant active sites and high surface area have been widely recognized as high‐performance catalytic materials. However, the templated synthesis is complex and costly. Herein, we report a mesoporous rhodium (m‐Rh) that can be readily synthesized from entangled nanofibres of Rh and Y2O3 without templates. The entangled nanofibres, prepared from uniform Rh‐Y alloys under redox atmosphere, were the key precursor in the synthesis processes. Moreover, the m‐Rh efficiently catalyzed carbon dioxide reforming of methane (DRM) at a low reaction temperature of 683 K. Further, electrochemical methods of CO electro‐oxidation were innovatively used to demonstrate the stability of CO and oxygen species for the DRM reaction. 相似文献
19.
In this work, we analyse the influence of the sample shape on the experimental determination of the thermal diffusivity of
materials used in several engineering fields. By means of a simple method we obtain good estimations of the overall thermal
diffusivity for homogeneous or inhomogeneous materials. The method is based on the combination of simple temperature measurements
with the analytical solution of the 3D differential Fourier’s equation applied to cartesian geometry. The classical transient
analytical solution based on the separation of space and time variables is adapted to particular thermal boundary conditions.
By associating these solutions with the measurements obtained on a simple experimental bench, the thermal characterization
of materials can be achieved with a satisfactory precision. The present 3D study attempts to complete previous works dealing
with cartesian and cylindrical 1D and 2D models. Based on the same procedure, it sheds further light on the fast multidimensional
surface phenomena of heat exchange. Although we conclude that the 3D model does not provide the directional values typical
of anisotropic materials, our results revealed that thermal diffusivity can be useful in other respects, being advantageous
in the overall thermal characterization needed for sizing certain systems. 相似文献
20.
Bouchra Filali Baba Abdelali Kerbal Najib Bitit Brahim El‐Bali Jean Escudie Henry Ranaivonjatovo Michael Bolte 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(5):e205-e206
The title compound, C19H15NO6, contains a planar isoxazole ring. An intramolecular hydrogen bond is formed between the OH group attached to a phenyl ring and a carbonyl O atom. 相似文献