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91.
Andrew W. Smyth Sami F. Masri Elias B. Kosmatopoulos Anastassios G. Chassiakos Thomas K. Caughey 《International Journal of Non》2002,37(8):378-1451
Adaptive estimation procedures have gained significant attention by the research community to perform real-time identification of non-linear hysteretic structural systems under arbitrary dynamic excitations. Such techniques promise to provide real-time, robust tracking of system response as well as the ability to track time variation within the system being modeled. An overview of some of the authors’ previous work in this area is presented, along with a discussion of some of the emerging issues being tackled with regard to this class of problems. The trade-offs between parametric-based modeling and non-parametric modeling of non-linear hysteretic dynamic system behavior are discussed. Particular attention is given to (1) the effects of over- and under-parameterization on parameter convergence and system output tracking performance, (2) identifiability in multi-degree-of-freedom structural systems, (3) trade-offs in setting user-defined parameters for adaptive laws, and (4) the effects of noise on measurement integration. Both simulation and experimental results indicating the performance of the parametric and non-parametric methods are presented and their implications are discussed in the context of adaptive structures and structural health monitoring. 相似文献
92.
93.
94.
Unoccupied titanium 3d states due to subcluster formation in stoichiometric TiO2 nanoparticles 下载免费PDF全文
Sami Auvinen Matti Lahti Matti Alatalo 《International journal of quantum chemistry》2015,115(17):1175-1180
The source of unoccupied Ti 3d states in the case of stoichiometric anatase structured (TiO2)n clusters has been investigated using ab initio methods. These unoccupied gap states appear for example in the case of a stoichiometric (TiO2)38 cluster. We show that the origin of these gap states is related to effective subcluster formation which gives rise to empty defect‐like gap states, when these states are split off from conduction band. © 2015 Wiley Periodicals, Inc. 相似文献
95.
Zouhaier Bouallagui Mohamed Bouaziz Salwa Lassoued Jean Marc Engasser Mohamed Ghoul Sami Sayadi 《Applied biochemistry and biotechnology》2011,163(5):592-599
We previously reported the production of high yields of hydroxytyrosol through the bioconversion of tyrosol. In the present
work, hydroxytyrosol was subjected to the lipase catalyzed acylation aiming for the recovery of more lipophilic esters that
might be easily incorporated in cosmetic and food preparations. Hydroxytyrosyl acetate and hydroxytyrosyl oleate were produced
with respective molar esterification yields of 98% and 78%. DPPH free radical quenching potency demonstrated that the acylation
of hydroxytyrosol did not alter its antioxidant activity. The acylated esters were shown to be more effective than the natural
antioxidant: caffeic acid and two synthetic ones as BHA and BHT. Antiproliferative activity on human cervical cells (HeLa)
resulted in IC50 values of 0.46, 0.42 and 0.33 mM for hydroxytyrosol and its acetyl and oleyl esters, respectively. Additionally, when used
at a non-cytotoxic concentration (100 μM), these compounds showed significant effectiveness in preventing iron-induced oxidative
stress, resulting in a reduction of 30%, 36% and 38% in thiobarbituric acid-reactive substance production, respectively. 相似文献
96.
97.
Abdelhalim B. Mahmoud Shereen Abd Algaffar Wendy van de Sande Sami Khalid Marcel Kaiser Pascal Mser 《Molecules (Basel, Switzerland)》2021,26(13)
Redox-active drugs are the mainstay of parasite chemotherapy. To assess their repurposing potential for eumycetoma, we have tested a set of nitroheterocycles and peroxides in vitro against two isolates of Madurella mycetomatis, the main causative agent of eumycetoma in Sudan. All the tested compounds were inactive except for niclosamide, which had minimal inhibitory concentrations of around 1 µg/mL. Further tests with niclosamide and niclosamide ethanolamine demonstrated in vitro activity not only against M. mycetomatis but also against Actinomadura spp., causative agents of actinomycetoma, with minimal inhibitory concentrations below 1 µg/mL. The experimental compound MMV665807, a related salicylanilide without a nitro group, was as active as niclosamide, indicating that the antimycetomal action of niclosamide is independent of its redox chemistry (which is in agreement with the complete lack of activity in all other nitroheterocyclic drugs tested). Based on these results, we propose to further evaluate the salicylanilides, niclosamide in particular, as drug repurposing candidates for mycetoma. 相似文献
98.
The approximate solutions of Dirac equation with Morse potential in the presence of Coulomb-like tensor potential are obtained by using Laplace transform (LT) approach. The energy eigenvalue equation of the Dirac particles is found and some numerical results are obtained. By using convolution integral, the corresponding radial wave functions are presented in terms of confluent hypergeometric functions. 相似文献
99.
Six new, sterically demanding bis(benzimidazolium) salts (2a–f) as NHC precursors have been synthesized and characterized. These salts, in combination with palladium acetate, provide active catalysts for the cross‐coupling of aryl chlorides and bromides under mild conditions in aqueous media. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
100.
B. S. Yilbas 《Heat and Mass Transfer》1998,33(5-6):495-505
The use of a Fourier heating model in high intensity laser material processing is limited due to the assumptions made in
the model. An electron-kinetic theory may offer an alternative solution to the problem. Consequently, in the present study
an electron-kinetic theory approach is introduced to model the 3-dimensional laser heating process. The phase change and conduction
effects are encountered when driving the governing equations. To simulate the moving heat source, a scanning velocity of the
laser beam is considered, in this case, the laser beam scans the workpiece surface with a constant velocity. The governing
heat transfer equation is in the form of integro-differential equation, which does not yield the analytical solution. Therefore,
a numerical method employing an explicit scheme is introduced to discretize the governing equations. To validate the theoretical
predictions, an experiment is conducted to measure the surface temperatures of the workpiece substrate during Nd YAG laser
heating process. It is found that the rapid increase in temperature occurs in surface vicinity due to the successive electron-lattice
site atom collisions. The depth of melting zone increases as the heating progresses and the temperature remains almost constant
at the melting temperature of the substrate in the surface vicinity. In addition, the theoretical predictions agree well with
the experimental findings.
Received on 4 August 1997 相似文献