High-Q and temperature stable photonic biosensor based on grating waveguides

Optical and Quantum Electronics - Evaluation of polarization control by polarization attractor based on stimulated Raman scattering in optical fiber is presented. Performed simulations are...     

Rewetting analysis of hot surfaces with internal heat source by the heat balance integral method

A two region conduction-controlled rewetting model of hot vertical surfaces with internal heat generation and boundary heat flux subjected to constant but different heat transfer coefficient in both wet and dry region is solved by the Heat Balance Integral Method (HBIM). The HBIM yields the temperature field and quench front temperature as a function of various model parameters such as Peclet number, Biot number and internal heat source parameter of the hot surface. Further, the critical (dry out) internal heat source parameter is obtained by setting Peclet number equal to zero, which yields the minimum internal heat source parameter to prevent the hot surface from being rewetted. Using this method, it has been possible to derive a unified relationship for a two-dimensional slab and tube with both internal heat generation and boundary heat flux. The solutions are found to be in good agreement with other analytical results reported in literature.     

Existence of electrochromic reversibility at the 1000th cyclic voltammetry for spin coating WO3 film

Ionics - The precursor solutions prepared using sol-gel method are used for the synthesis of WO3 films by spin coating method. The onset of the crystalline phase of WO3 occurs at...     

On Inverse Limits and Direct Limits for Fuzzy Topological Spaces

Li has introduced the concepts of inverse system and direct system for fuzzy topological spaces and studied inverse limits and direct limits on such spaces by presenting the explicit constructions of these limits.In this paper some important concepts of fuzzy topology,such as,product fuzzy topology,quotient fuzzy topology,fuzzy continuity etc.,are used for further study of inverse limits and direct limits for fuzzy topological spaces.     

Concise synthesis of novel oxa-bridged compounds

[structures: see text] A stereoselective strategy for the replacement of the 1,2-dihaloalkene bridge of tetrahalonorbornyl derivatives by an oxygen bridge involving stepwise controlled oxidation, cleavage of the dione thus formed, and reiterative intramolecular S(N)2 displacement of two bridgehead halogens is devised. The synthesis of four highly strained pentacyclic bis-oxa-bridged derivatives 10, 27, 28, and 29 with interesting structural variations is presented. The two oxa bridges are syn to each other, separated by central cyclohexane and cycloheptane rings in 10 and 27, while they are anti to each other and are separated by central cyclopentane and furan rings in 28 and 29. In the case of the highly symmetric bis-oxa-bridged derivative 10 the two syn oxa bridges constrain the central cyclohexane ring into the boat form. The endo,anti,endo 2:1 bis adducts of 1,2,3,4-tetrahalo-5,5-dimethoxycyclopenta-1,3-diene with cyclopentadiene were prepared for the first time, while the reactivites of previously unexplored bis adducts derived from furan and cycloheptatriene were revealed.     

Method for determination of radium in seawater using MnO<Subscript>2</Subscript> co-precipitation technique

Radium is considered to be a useful tracer for studying various physical processes of seawater. There are several methods for analysis of radium; however, analysis of radium in seawater by those analytical techniques is a tedious job. Thus a new methodology was optimized for analysis of radium in sea water using MnO₂ co-precipitation followed by gamma spectrometry. The method produced good yield which ranged from 85–98%. The method is simple and requires less amounts of chemicals and no use of acids. Seawater from different western Indian coastal environments viz. Tarapur, Mumbai and Goa were collected and analysed for ²²⁶Ra and ²²⁸Ra using this method.     

Neutrino absorption by <Emphasis Type="Italic">W</Emphasis> production in the presence of a magnetic field

In this work we calculate the damping rate of the electron type neutrinos into W bosons and electrons in the presence of an external uniform magnetic field. The damping rate is calculated from the imaginary part of the W exchange neutrino self-energy diagram but in the weak field limit, and we compare our result with the existing one.     

TROSY-based z-exchange spectroscopy: application to the determination of the activation energy for intermolecular protein translocation between specific sites on different DNA molecules

A two-dimensional TROSY-based z-exchange 1H-15N correlation experiment for the quantitative analysis of kinetic processes in the slow exchange regime is presented. The pulse scheme converts the product operator terms Nz into 2NzHz and 2NzHz into -Nz in the middle of the z-mixing period, thereby suppressing the buildup of spurious semi-TROSY peaks arising from the different relaxation rates for the Nz and 2NzHz terms and simplifying the behavior of longitudinal magnetization for an exchanging system during the mixing period. Theoretical considerations and experimental data demonstrate that the TROSY-based z-exchange experiment permits quantitative determination of rate constants using the same procedure as that for the conventional non-TROSY 15Nz-exchange experiment. Line narrowing as a consequence of the use of the TROSY principle makes the method particularly suitable for kinetic studies at low temperature, thereby permitting activation energies to be extracted from data acquired over a wider temperature range. We applied this method to the investigation of the process whereby the HoxD9 homeodomain translocates between specific target sites on different DNA molecules via a direct transfer mechanism without going through the intermediary of free protein. The activation enthalpy for intermolecular translocation was determined to be 17 kcal/mol.