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101.
Erdal Karapınar Salvador Romaguera Kenan Taş 《Central European Journal of Mathematics》2013,11(3):552-560
We prove a fixed point theorem for cyclic orbital generalized contractions on complete metric spaces from which we deduce, among other results, generalized cyclic versions of the celebrated Boyd and Wong fixed point theorem, and Matkowski fixed point theorem. This is done by adapting to the cyclic framework a condition of Meir-Keeler type discussed in [Jachymski J., Equivalent conditions and the Meir-Keeler type theorems, J. Math. Anal. Appl., 1995, 194(1), 293–303]. Our results generalize some theorems of Kirk, Srinavasan and Veeramani, and of Karpagam and Agrawal. 相似文献
102.
103.
Volkan Murat Yılmaz Tuğba Tunç Parlak Kenan Yıldız 《Journal of Thermal Analysis and Calorimetry》2018,133(1):135-176
The review consists of four parts. Part I is about the thermal transformation in clay minerals under firing and about the properties of fired clay. The transformations in the clay are expressed quantitatively with the extent of conversion, α, which is the function of two parameters of firing process, time t and temperature T: α?=?f(t, T). Part II is about the estimation of firing temperature after the analysis of the products of firing clays. All the estimations are speculative, without mathematical equations. It is impossible to derive the value of only one variable T from α?=?f(t,T), the function of two variables. Part III is about the long-term inverse transformation in fired ceramic paste under ambient conditions. The mass gain as a function of time is used for the evaluation of the time elapsed from the ancient firing, t. Part IV is about the visualization of the extent of conversion of the clay in the paste after all direct and reverse reactions, i.e., α. 相似文献
104.
105.
In order to envision the radiation exposure during Neutron Activation Analysis (NAA) experiments, a software called Activity
Predictor is developed using JavaTM programming language. The Activity Predictor calculates activities, exposure rates and gamma spectra of activated samples
for NAA experiments performed at Radiation Science and Engineering Center (RSEC), Penn State Breazeale Reactor (PSBR). The
calculation procedure for predictions involves both analytical and Monte Carlo methods. The Activity Predictor software is
validated with a series of activation experiments. It has been found that Activity Predictor software calculates the activities
and exposure rates precisely. The software also predicts gamma spectrum for each measurement. The predicted spectra agreed
partially with measured spectra. The error in net photo peak areas varied from 4.8 to 51.29%, which is considered to be due
to simplistic modeling, statistical fluctuations and unknown contaminants in the samples. 相似文献
106.
Kenan DJ Walsh EB Meyers SR O'Toole GA Carruthers EG Lee WK Zauscher S Prata CA Grinstaff MW 《Chemistry & biology》2006,13(7):695-700
Amphiphilic macromolecules containing a polystyrene-adherent peptide domain and a cell-repellent poly(ethylene glycol) domain were designed, synthesized, and evaluated as a cytophobic surface coating. Such cytophobic, or cell-repellent, coatings are of interest for varied medical and biotechnological applications. The composition of the polystyrene binding peptide domain was identified using an M13 phage display library. ELISA and atomic force spectroscopy were used to evaluate the binding affinity of the amphiphile peptide domain to polystyrene. When coated onto polystyrene, the amphiphile reduced cell adhesion of two distinct mammalian cell lines and pathogenic Staphylococcus aureus strains. 相似文献
107.
Determination of tree ring chemistry using Neutron Activation Analysis (NAA) is part of an ongoing research between Penn State
University (PSU) and Cornell University, The Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology.
Tree-ring chemistry yields valuable data for environmental event signatures. These signatures are a complex function of elemental
concentration. To be certain about concentration of signature elements, it is necessary to perform the measurements and corrections
with the lowest error and maximum accuracy possible. Accurate and precise values of energy dependent neutron flux at dry irradiation
tubes and detector efficiency for tree ring sample are calculated for Penn State Breazeale Reactor (PSBR). For the calculation
of energy dependent and self shielding corrected neutron flux, detailed model of the TRIGA Mark III reactor at PSU with updated
fuel compositions was prepared using the MCNP utility for reactor evolution (MURE) libraries. Dry irradiation tube, sample
holder and sample were also included in the model. The thermal flux self-shielding correction factors due to the sample holder
and sample for were calculated and verified with previously published values. The Geant-4 model of the gamma spectroscopy
system, developed at Radiation Science and Engineering Center (RSEC), was improved and absolute detector efficiency for tree-ring
samples was calculated. 相似文献
108.
K. Bourenane A. Keffous G. Nezzal A. Boukezzata S. Naama 《Surface and interface analysis : SIA》2007,39(5):392-396
In this work, an experimental study on the etching of p‐type hot‐pressed silicon carbide (SiC) was carried out in HF/K2S2O8 solutions. The SiC wafers used in this work were p‐type polycrystalline materials, supplied by Goodfellow, with an acceptor concentration of 2.31 × 1012 cm?3. The SiC substrate was a hot‐pressed material, the latter realized from a mixture of 1 part of SiO2 with 3 parts of C (carbon) ‘1SiO2 + 3C’ heated in an oven at 2500 °C. In order to facilitate the chemical etching of the SiC substrate, a thin aluminium film was deposited on the SiC substrate. The morphology of the etched surface was examined with varying K2S2O8 concentration. The surfaces of the etched samples were analysed using secondary ions mass spectrometry (SIMS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT‐IR) and photoluminescence (PL). The surface morphology of the samples etched in HF/K2S2O8 is shown to depend on the solution composition. The investigation of the effect of the HF/K2S2O8 solution on SiC samples shows that as K2S2O8 concentration increases, the chemical etching reveals defects with random geometry. Finally, chemical etching of p‐type SiC induces a decrease in the PL intensity, which indicates clearly the defects on the polycrystalline SiC surface. In addition, the result is very interesting, as to date no chemical etching solution at low temperature (<100 °C) has been developed for SiC. Finally, we have proposed a dissolution mechanism of SiC in 2HF/1K2S2O8 solutions. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
109.
Hindered primary amines that resist other reagents can be converted to carbamoylphosphonates by means of 4-nitrophenoxycarbonylphosphonate diesters in high yields and under mild conditions. 相似文献
110.
May Korachi Zi?an Turan Kenan ?entürk Fikrettin ?ahin Necdet Aslan 《Journal of Electrostatics》2009,67(4):678-685
A newly developed, low cost plasma system that works at atmospheric pressure and operates with both DC or AC high voltage power supplies was presented. This system was tested for its biocidal effect on a wide range of micro-organisms in water. Optimal killing parameters such as time, temperature and AC and DC high voltage power levels were tested for bacteria (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus mutans, Bacillus subtilis), yeast (Candida albicans), fungi (Aspergillus niger) and green algae. Results show this system to have a very efficient biocidal effect on most bacteria, algae and fungi in water. 相似文献