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1.
The clinical and bacteriologic efficacy of topically applied ciprofloxacin was studied in 60 patients with chronic suppurative otitis media. Two hundred fifty and 125 microg/ml concentrations of ciprofloxacin solutions were given to two groups of patients. The duration of therapy was determined according to the clinical cure at follow-up. More than 21 days of therapy was not needed in any patient. The clinical cure rate with 250 microg/ml ciprofloxacin was 78.1% at 14 days and with 125 microg/ml it was 83.3%. However, a 100% clinical cure rate and complete bacteriologic eradication was obtained in 21 days in both groups. In each group only one patient had otomycosis by the fourteenth day of therapy, although ear discharge had ceased. It was concluded that 125 microg/ml ciprofloxacin could be applied as successfully as 250 microg/ml, and the duration of therapy had to be at least 14 days. This new dosage regimen can be adopted as an optimal dosage for ototopical application of ciprofloxacin in chronic suppurative otitis media. It will also obviously decrease the expense of therapy. 相似文献
2.
3.
WSNs (wireless sensor networks) consist of thousands of tiny nodes having the capability of sensing, computation, and wireless communications. Unfortunately these devices are limited energy devices, that is means we must save energy as much as possible, to increase network life time as long as possible. In this paper we introduce NEER--normalized energy efficient routing protocol that increases network life time through switching between AODV protocol that depends on request-reply routing, and MRPC that depends on residual battery in routing. 相似文献
4.
Zarife Sibel Şahin Mehmet Demir Tuğrul Yıldırım Ömer Yurdakul Dursun Ali Köse 《International Journal of Hydrogen Energy》2021,46(54):27631-27642
Four novel metal organic framework (MOF) structures containing acesulfame (ace) and 1,10-phenanthroline (phen) ligands of Co2+, Ni2+, Cu2+ and Zn2+ metal cations were synthesized. The crystal structure analysis of three compounds (1, 2, and 3) was also performed. The structural formula for complex 4 is proposed based on spectroscopic and thermal analysis data. It has been determined that structures 1, 2, and 4 are in a distorted octahedral geometry. It has been suggested that the charge balance of the coordination sphere with 2+ is provided by two monoanionic ace ligands located outside the coordination sphere as counter-ion. In structure 3, there are two CuII metal cations, two phen ligands coordinated as bidentate to each metal cation and ace ligand that provides monoanionic-monodentate coordination. The Cu2+ cation has distorted bipyramidal geometry. The maximum hydrogen gas adsorption has been found 1.4575 mL/g (0.046 wt%) for the Ni complex. 相似文献
5.
In this paper, we report the transmission electron microscopy (TEM) observations on the incorporation of Ti transition metal element into β-SiAlON crystal structure in a bulk β-SiAlON–TiN composite material. Considering our energy dispersive X-ray (EDX) and electron energy loss (EEL) spectroscopy results acquired by using nanometre-scale focused electron probe in scanning transmission electron microscopy (STEM) mode, the Ti-K characteristic X-ray lines and Ti-L3,2 edges were detected in the chemical composition of the β-SiAlON grains. These results clearly reveal that Ti can enter into the β-SiAlON crystal structure. It is anticipated that this data will provide the new engineering insights on the production of transition metal element doped SiAlON-based materials for different applications. 相似文献
6.
UV-Visible (UVV) technique used to monitor powder coating and its dissolution processes from hard latex particles. Three sets
of latex coatings were prepared from poly(methyl methacrylate) (PMMA) particles. The first set of coatings was annealed at
elevated temperatures in various time intervals during which reflected photon intensity, Irf, was measured. The second set of coatings was annealed at various temperatures in 10 min time intervals during which transmitted
intensity, Itr, was measured. Irf first decreased and then increased as the annealing temperature was increased. Decrease in Irf was explained with the void closure mechanism due to viscous flow. Increase in Itr and Irf against time and temperature were attributed to an increase in crossing density at the junction surface. The activation energy
of viscous flow, ΔH, was measured and found to be around 8 kcal/mol and the back and forth activation energies (ΔErf and ΔEtr) were measured and found to be around 49 and 53 kcal/mol for a reptating polymer chain across the junction surface. Diffusion
of solvent molecules (chloroform) into the annealed latex coatings was followed by desorption of PMMA chains for the third
set of films. Desorption of pyrene, P, labeled PMMA chains was monitored in real-time by the absorbance change of pyrene in
the polymer-solvent mixture. A diffusion model with a moving boundary was employed to quantify real-time UVV data. Diffusion
coefficients of desorbed PMMA chains were measured and found to be between 2 and 0.6 × 10−11 cm2 s−1 in the 100 and 275°C temperature range.
Presented at the 2000 Spring Meeting of the PMSE Div. of the American Chemical Society, March 26–30, 2000, San Francisco,
CA.
Dept. of Physics, Maslak 80626 Istanbul, Turkey.
Dept. of Physics, 22030 Edirne, Turkey. 相似文献
7.
This study focuses on the fabrication of poly(vinyl alcohol)/ poly(vinyl pyrrolidone)-Iodine nanofibers via electrospinning. Electrospun fibers were characterized by FT-IR, DSC and SEM techniques. DSC results indicated that the thermal stability of nanofibers were improved after the addition of chitosan and poloxamer 188. SEM images showed that the spongiform structure is much more compact and fibrous in the case of added chitosan, with an average fiber diameter of 374 nm, whereas the addition of poloxamer 188 resulted in a more porous and beaded composition, with average fiber diameter of 489 nm. 相似文献
8.
Mixed surfactant solutions consisting of cationic/nonionic surfactants were prepared in different compositions of the components
in aqueous solution in order to determine the surface properties. The critical micelle concentration (CMC) of aqueous solutions
of the individual surfactants cetyl trimethyl ammonium bromide (CTAB) and polysorbate nonionics, and their mixtures are determined
at different proportions. The results show that there is synergistic behavior in mixtures at higher mole fraction of nonionic
surfactant. The effect of the alkyl chain on the CMC is also determined. 相似文献
9.
Emel Ozel Hilmi Yurdakul Servet Turan Matteo Ardit Giuseppe Cruciani Michele Dondi 《Journal of the European Ceramic Society》2010,30(16):3319-3329
Cobalt-doped willemite is a promising blue ceramic pigment, but some important aspects concerning crystal structure, optical properties and technological behaviour are still undisclosed. In order to get new insight on these features, willemite pigments (Zn2?xCoxSiO4, 0 < x < 0.3) were synthesized by the ceramic route and characterized from the structural (XRPD with Rietveld refinement), optical (DRS and colorimetry), microstructural (SEM, STEM, TEM, EDX, EELS) and technological (simulation of the ceramic process) viewpoints. The incorporation of cobalt in the willemite lattice, taking preferentially place in the Zn1 tetrahedral site, induces an increase of unit-cell parameters, metal–oxygen distances, and inter-tetrahedral tilting. It causes shifting and enhanced splitting of spin-allowed bands of Co2+ in tetrahedral coordination, implying slight changes of crystal field strength Dq and Racah B parameter, but increasing spin-orbit coupling parameter λ. Willemite pigments impart deep blue hue to ceramic glazes and glassy coatings with a colouring performance better than commercial Co-bearing colorants in the 800–1200 °C range. Detailed SEM-TEM investigation and microanalysis proved that no diffusion phenomena occur at the pigment–glassy coating interface and that willemite pigments are chemically inert during firing at 1050 °C. 相似文献
10.
Black iron-chromium (Fe-Cr) bearing oxide pigments are generally utilised as effective colourants in a wide variety of applications. However, in the case of their use within ZnO-containing glazes, they yield an undesirable brown colour instead of expected black colour. In order to understand the colour change in this system, we report the use of focused ion beam (FIB) sample preparation technique followed by the use of analytical transmission electron microscopy (TEM) characterisation techniques. According to the results, the formation of a reaction layer between the pigment and glaze was identified with an average composition of Zn0.48Fe0.79Cr1.32O4. Additionally, the valance of Fe was determined as 3+ in the pigment grain, whereas 2+ in the reaction layer and the glaze, respectively. Therefore, it was concluded that the colour change is occurring as result of the valence variation of Fe, the formation of Zn0.48Fe0.79Cr1.32O4 compound and the outward diffusion of Fe into the glaze. 相似文献