Optical Solitons in Fiber Bragg Gratings with Polynomial Law Nonlinearity and Cubic–Quartic Dispersive Reflectivity

Optics and Spectroscopy - Optical solitons with fiber Bragg gratings and polynomial law of nonlinear refractive index are addressed in the paper. The auxiliary equation approach together with an...     

Generalized submaximal spaces

The notion of generalized submaximal spaces is introduced and studied. Properties and characterizations of generalized submaximal spaces are discussed.     

More on θ-compact fuzzy topological spaces

Recently, El-Naschie has shown that the notion of fuzzy topology may be relevant to quantum particle physics in connection with string theory and ε^∞ theory. In 2005, Caldas and Jafari have introduced θ-compact fuzzy topological spaces. The purpose of this paper is to investigate further properties of θ-compact fuzzy topological spaces. Moreover, the notion of θ-closed fuzzy topological spaces is introduced and properties of it are obtained.     

Colour naming

An experimental study exploring colour ranges corresponding to different colour names has been conducted. Available colour terms in Turkish language have been identified and the most frequently known or used colour terms have been attained. Using the Munsell Color System, colour ranges reflecting the colour naming and colour perception of Turkish people, have been constructed for each colour term. The discussion of the findings and observations during the research are also included.     

High Enrichment of MMP-9 and Carboxypeptidase A by Tweezing Adsorptive Bubble Separation (TABS)

Tweezing adsorptive bubble separation (TABS) was used as a method for the enrichment of matrix metalloproteinases (92-kDa type IV, gelatinase B (MMP-9)) and carboxypeptidase A (CPA) from dilute aqueous solutions. The method is based on the chelation of metalloenzymes applying 2-(carbamoylmethyl-(carboxymethyl)amino)acetic acid (ADA) coupled with an octyl part to form a surface active unit. MMP-9 could be enriched with an enrichment ratio of 12.0 and a recovery of 87.3%, and CPA could be enriched 18.8-fold and with 95.3% recovery. Both enzymes were enriched without significant losses of enzymatic activity. To verify that the enzymes were tweezed by ADA-C8 without abstraction of the zinc ions from the active center, TABS trials were additionally conducted with zinc ions in complex with ADA-C8, which revealed only negligible enrichment ratios of the enzymes (2.2 for MMP-9 and 0.2 for CPA). The results obtained impressively demonstrate that zinc-containing proteases can be enriched selectively and efficiently by TABS.     

Enrichment of the glycoalkaloids alpha-solanine and alpha-chaconine from potato juice by adsorptive bubble separation using a pH gradient

For the first time, the solanidine alkaloids alpha-solanine and alpha-chaconine could be quantitatively enriched from potato juice by Adsorptive Bubble Separation (ABS) with a pH gradient. The enrichment into the foam was influenced by the pH value, bubble size, and gas flow rate. The efficiency was highest on using diluted samples with a concentration between 2 and 6 mg L(-1) of the alkaloids at pH 6.0. The experiments with a standard solution of each alkaloid confirmed that these substances can be quantitatively enriched into the 'spumat' without surface active potato proteins. The transfer into the foam fraction under these conditions was similar to that from the aqueous potato extract.     

Thermal Analysis of Gold Nanorods Heated with Femtosecond Laser Pulses

We present an axisymmetric computational model to study the heating processes of gold nanoparticles, specifically nanorods, in aqueous medium by femtosecond laser pulses. We use a two-temperature model for the particle, a heat diffusion equation for the surrounding water to describe the heat transfer processes occurring in the system, and a thermal interface conductance to describe the coupling efficiency at the particle/water interface. We investigate the characteristic time scales of various fundamental processes, including lattice heating and thermal equilibration at the particle/surroundings interface, the effects of multiple laser pulses, and the influence of nanorod orientation relative to the beam polarization on energy absorption. Our results indicate that the thermal equilibration at the particle/water interface takes approximately 500 ps, while the electron-lattice coupling is achieved at approximately 50 ps when a 48×14 nm gold nanorod is heated to a maximum temperature of 1270 K with the application of a laser pulse having 4.70 J/m(2) average fluence. Irradiation by multiple pulses arriving at 12.5 ns time intervals (80 MHz repetition rate) causes a temperature increase of no more than 3 degrees during the first few pulses with no substantial changes during the subsequent pulses. We also analyze the degree of the nanorods' heating as a function of their orientation with respect to the polarization of the incident light. Lastly, it is shown that the temperature change of a nanorod can be modeled using its volume equivalent sphere for femtosecond laser heating within 5-15% accuracy.