Long distance atomic teleportation with as good success as desired

Long distance atomic teleportation (LDAT) is of prime importance in long distance quantum communication. Scheme proposed by Bose et al. (1999) in principle enables us to have LDAT using cavity decay. However it gives message state dependent fidelity and success rate. Here, using interaction of entangled coherent states with atom–cavity systems and a two-step measurement, we show how, LDAT can be achieved with unit fidelity and as good success as desired under ideal conditions. The scheme is unique in that, the first measurement predicts success or failure. If success is predicted then second measurement gives perfect teleportation. If failure is predicted the message-qubit remains conserved therefore a second attempt may be started. We found that even in presence of decoherence due to dissipation of energy our scheme gives message state independent success rate and almost perfect teleportation in single attempt with mean fidelity of teleportation equal to 0.9 at long distances. However if first attempt fails, unlike ideal case where message-qubit remains conserved with unit fidelity, in presence of decoherence the message-qubit remains conserved to some degree, therefore mean fidelity of teleportation can be increased beyond 0.9 by repeating the process.     

An Efficient,Basic Resin-Mediated,One-Pot Synthesis of Dithiocarbazates Through Alcoholic Tosylates

A quick and efficient, one-pot synthesis of dithiocarbazates was accomplished in high yields by the reaction of various alcoholic tosylates of primary, secondary, and tertiary alcohols, with substituted hydrazines using an Amberlite IRA 400 (basic resin)/CS ₂ system. The reaction conditions are mild with simpler work-up procedures than previously reported methods.     

Hexavalent Chromium-Thioacetamide Redox System Initiated Polymerization of Acrylonitrile

Polymerization of acrylonitrile initiated by the Cr⁶⁺/thioacetamide redox system was studied in nitrogen atmosphere in the temperature range 35–45°C. The rate of polymerization and the rate of Cr⁶⁺ ion disappearance were measured. The effect of certain water-miscible organic solvents, neutral electrolytes, and complexing agents on the rate of polymerization was investigated. Chromic acid alone did not initiate the polymerization under deaerated and undeaerated conditions. Depending on the results obtained, a suitable kinetic scheme was proposed and various rate parameters were evaluated.     

The Synthesis of Poly(Dimethylsiloxane-b-Isobutylene-b-Dimethylsiloxane) and Poly-(Dimethylsiloxane-b-Isobutylene-b-Dimethylsiloxane) from Alcohol-Telechelic Polyisobutylenes

The purpose of these studies was to combine polydimethylsiloxane (PDMS) and polyisobutylene (PIB) sequences into novel triblock, PDMS-b-PIB-b-PDMS, and multiblock, (-PDMS-b-PIB-b-PDMS-)n, copolymers. The key toward syntheses was the definition of conditions for the initiation of living anionic polymerization of hexamethyl-cyclotrisiloxane (D₃) at the CH₂OLi termini of well-defined tele-chelic PIB sequences. Subsequent deactivation of living D₃ polymerization charges with Me₃ SiCl yielded the target triblock whereas stoichiometric amounts of Me₂ SiCl₂ gave the multiblock copolymer.     

Nanocomposite blend gel polymer electrolyte for proton battery application

A proton-conducting nanocomposite gel polymer electrolyte (GPE) system, [35{(25 poly(methylmethacrylate) (PMMA) + 75 poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP))?+?xSiO₂}?+?65{1 M NH₄SCN in ethylene carbonate (EC) + propylene carbonate (PC)}], where x?=?0, 1, 2, 4, 6, 8, 10, and 12, has been reported. The free standing films of the gel electrolyte are obtained by solution cast technique. Films exhibit an amorphous and porous structure as observed from X-ray diffractometry (XRD) and scanning electron microscopy (SEM) studies. Fourier transform infrared spectrophotometry (FTIR) studies indicate ion–filler–polymer interactions in the nanocomposite blend GPE. The room temperature ionic conductivity of the gel electrolyte has been measured with different silica concentrations. The maximum ionic conductivity at room temperature has been observed as 4.3?×?10^?3?S?cm^?1 with 2 wt.% of SiO₂ dispersion. The temperature dependence of ionic conductivity shows a typical Vogel-Tamman-Fulcher (VTF) behavior. The electrochemical potential window of the nanocomposite GPE film has been observed between ?1.6 V and 1.6 V. The optimized composition of the gel electrolyte has been used to fabricate a proton battery with Zn/ZnSO₄·7H₂O anode and PbO₂/V₂O₅ cathode. The open circuit voltage (OCV) of the battery has been obtained as 1.55 V. The highest energy density of the cell has been obtained as 6.11 Wh?kg^?1 for low current drain. The battery shows rechargeability up to 3 cycles and thereafter, its discharge capacity fades away substantially.     

Radical Photopolymerization of Vinyl Monomers

Abstract

Photopolymerization is the initiation by light of a chain polymerization process. In the more general sense, photopolymerization implies the increase of molecular weight caused by light. Photopolymerization is not only useful for the detection and identification of photochemically produced free radicals; since photopolymerization reactions can be started or stopped at will by the simple expedient of turning on or off light, a means is provided for studying the nonsteady-state kinetics of polymerization [1]. Photopolymerization also allows for the subtle control of molecular weight and molecular weight distribution by varying the intensity of light. Photopolymerization can be confined to local regions since the light can be spatially controlled. Photopolymerization can be carried out at very low temperatures. Hence, chain-transfer processes leading to branched macromolecules will be absent. Photopolymerization at low temperature yields the low-energy stereospecific polymeric species, namely the syndiotactic configuration of the polymer [2]. Certain monomers can only be polymerized at low temperature, i.e., they have low ceiling temperatures; the photopolymerization offers this possibility [3]. Because photopolymerization need not be carried out at elevated temperatures, it has applications to biochemistry. One important application of the method is in disk electrophoresis [4]. Photopolymerization played an important role in the early development of polymer chemistry. One of the first procedures for polymerizing vinyl monomers was to expose the monomer to sunlight. Blyth and Hoffman [5] reported the polymerization of styrene by this method in 1845.     

Triton-B-Catalyzed,Efficient, One-Pot Synthesis of Dithiocarbazates Through Alcoholic Tosylates

A quick, efficient, one-pot synthesis of dithiocarbazates was accomplished in high yields by the reaction of various tosylates of primary, secondary, and tertiary alcohols with a variety of substituted hydrazines using the benzyl–trimethylammonium hydroxide (Triton-B)/CS₂ system. The reaction conditions are mild with simpler workup procedures than the reported methods.     

Alkylation of Ethanolamines: An Approach to a Novel Class of Functional Surfactants

Some monomeric and dimeric surfactants with functional head groups have been synthesized from di- and triethanolamine synthons. The treatment of alkyl bromide with triethanolamine resulted in simultaneous N-alkylation and O-alkylation products. However, with diethanolamine, N-alkylated products were obtained, which were further used to synthesize various double-tailed surfactants and gemini surfactants.