Transparent and flexible field emission display device based on single‐walled carbon nanotubes

A fully transparent and flexible field emission device (FED) has been demonstrated. Single‐walled carbon nanotubes (SWCNTs) coated on arylite substrate were used as electron emitters for the FED and a novel metavanadate phosphor coated on the SWCNTs/arylite film was used as transparent and flexible screen. The SWCNTs/arylite based emitters and the SWCNTs/arylite/metal‐vanadate‐based phosphor showed a transmittance value of 92.6% and 54%, respectively. The assembled device also showed satisfactory transparency and flexibility as well as producing significant current. Metavanadate phosphor is considered to be an excellent candidate due to its superior luminescence properties and easy fabrication onto transparent and flexible conductive substrate at room temperature while retaining reasonable transparency of the substrate. Thus, its transparency and flexibility will open the door to next‐generation FEDs. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Self-propagating assembly of a molecular-based multilayer

Accelerated growth of a molecular-based material that is an active participant in its continuing self-propagated assembly has been demonstrated. This nonlinear growth process involves diffusion of palladium into a network consisting of metal-based chromophores linked via palladium.     

Nonstatic perfect fluid sphere in higher-dimensional space-time

It is shown that in the case of a spherical nonstatic fluid distribution undergoing shear-free motion the field equations in higher dimensional space-time can be reduced to a single second-order differential equation involving an arbitrary function of the radial co-ordinate. This result extends to higher dimensions a similar one obtained by Wyman and Faulkes earlier for 4D space-time. Solving this differential equation a number of new solutions is found, and the dynamical behaviour of one of the models is briefly discussed. The ansatz is later generalised to include the electromagnetic field as well.     

Third harmonic generation in layered media in presence of optical bistability of the fundamental

We study third harmonic generation in layered configuration when the fundamental exhibits bistable response. We consider two geometries, namely, a Fabry-Perot cavity with reflection coatings and a distributed feedback structure with alternate nonlinear layers. In both the cases for suitable choice of frequency, the power response at the fundamental frequency is bistable. We show that bistability of the fundamental leads to a multivalued character of the generated third harmonic in both the forward and backward directions. Moreover, we study frequency response in the case of the Fabry-Perot cavity and show that additional structures arise in the generated third harmonic due to frequency bistability of the fundamental. Our calculations suggest the possibility of an all optical switch at third harmonic frequency controlled by the parameters (like intensity, frequency) of the fundamental.     

Direct measurement of fine structure changing collisional losses in cold trapped 85Rb

Using a technique that consists in ionizing atoms out of the 5P _1/2 fragments originated in the cold collision process, we have measured the contribution of the fine structure changing collision (FS) to the total trap loss rate of cold ⁸⁵Rb. Our results show that FS contribution is responsible for about 4% of the total trap loss. This result should stimulate new theoretical discussions involving exoergic cold collisions. Received 26 October 1998 and Received in final form 2 February 1999     

An economic and environmental comparison of a biochemical and a thermochemical lignocellulosic ethanol conversion processes

With the world’s focus on rapidly deploying second generation biofuels technologies, there exists today a good deal of interest in how yields, economics, and environmental impacts of the various conversion processes of lignocellulosic biomass to transportation fuels compare. Although there is a good deal of information regarding these conversion processes, this information is typically very difficult to use on a comparison basis because different underlying assumptions, such as feedstock costs, plant size, co-product credits or assumed state of technology, have been utilized. In this study, a rigorous comparison of different biomass to transportation fuels conversion processes was performed with standard underlying economic and environmental assumptions so that exact comparisons can be made. This study looked at promising second-generation conversion processes utilizing biochemical and thermochemical gasification technologies on both a current and an achievable state of technology in 2012. The fundamental finding of this study is that although the biochemical and thermochemical processes to ethanol analyzed have their individual strengths and weaknesses, the two processes have very comparable yields, economics, and environmental impacts. Hence, this study concludes that based on this analysis there is not a distinct economic or environmental impact difference between biochemical and thermochemical gasification processes for second generation ethanol production.     

Synthesis of highly functionalized indeno[1,2-b]furans

Some novel functionalized indeno[1,2-b]furans were synthesized from the reaction of indandione/indanone and aldehydes at room temperature followed by the reaction of the Knoevenagel condendensed intermediate with 4-hydroxycoumarins in the presence of iodine as catalyst in dimethyl sulfoxide (DMSO) under thermal conditions. The reaction involved in a condensation and Michael addition followed by lactone ring opening and intramolecular cyclization process to afford the product in high yield in easy work-up procedure.     

Allylpalladium (II) complexes with dichalcogenoimidodiphosphinate ligands: Synthesis, structure, spectroscopy and their transformation into palladium chalcogenides

The synthesis, characterization and thermal behavior of new monomeric allylpalladium (II) complexes with dichalcogenoamidodiphosphinate anions are reported. The complexes [R = H, R′ = Prⁱ, E = S (1a); R = H, R′ = Prⁱ, E = Se (1b); R = H, R′ = Ph, E = S (1c); R = H, R′ = Ph, E = Se (1d); R = Me, R′ = Prⁱ, E = S (2a); R = Me, R′ = Prⁱ, E = Se (2b); R = Me, R′ = Ph, E = S (2c); R = Me, R′ = Ph, E = Se (2d)] have been prepared by room temperature reaction of [Pd(η³-CH₂C(R)CH₂)(acac)] (acac = acetylacetonate) with dichalcogenoimidodiphosphinic acids in acetonitrile solution. The complexes have been characterized by multinuclear NMR (¹H, ¹³C{¹H}, ³¹P{¹H}, ⁷⁷Se{¹H}), FT-IR and elemental analyses. The crystal structures of complexes 1a, 1d and 2d have been reported and they consist of a six-membered PdE₂P₂N ring (E = S for 1a and Se for 1d and 2d) and an allyl group, C₃H₄R(R = H for 1a and 1d and Me for 2d). Thermogravimetric studies have been carried out for few representative complexes. The complexes thermally decompose in argon atmosphere to leave a residue of palladium chalcogenides, which have been characterized by PXRD, SEM and EDS.     

Model Compounds for Iron Proteins. Structures and Magnetic, Spectroscopic, and Redox Properties of Fe(III)M(II) and [Co(III)Fe(III)](2)O Complexes with (&mgr;-Carboxylato)bis(&mgr;-phenoxo)dimetalate and (&mgr;-Oxo)diiron(III) Cores

A series of heterobimetallic complexes of the type [Fe(III)M(II)L(&mgr;-OAc)(OAc)(H(2)O)](ClO(4)).nH(2)O (2-5) and [{Fe(III)Co(III)L(&mgr;-OAc)(OAc)}(2)(&mgr;-O)](ClO(4))(2).3H(2)O (6) where H(2)L is a tetraaminodiphenol macrocyclic ligand and M(II) = Zn(2), Ni(3), Co(4), and Mn(5) have been synthesized and characterized. The (1)H NMR spectrum of 6 exhibits all the resonances between 1 and 12 ppm. The IR and UV-vis spectra of 2-5 indicate that in all the cases the metal ions have similar coordination environments. A disordered crystal structure determined for 3 reveals the presence of a (&mgr;-acetate)bis(&mgr;-phenoxide)-Ni(II)Fe(III) core, in which the two metal ions have 6-fold coordination geometry and each have two amino nitrogens and two phenolate oxygens as the in-plane donors; aside from the axial bridging acetate, the sixth coordination site of nickel(II) is occupied by the unidentate acetate and that of iron(III) by a water molecule. The crystal structure determination of 6 shows that the two heterobinuclear Co(III)Fe(III) units are bound by an Fe-O-Fe linkage. 6 crystallizes in the orthorhombic space group Ibca with a = 17.577(4) ?, b = 27.282(7) ?, c = 28.647(6) ?, and Z = 8. The two iron(III) centers in 6 are strongly antiferromagnetically coupled, J = -100 cm(-1) (H = -2JS(1).S(2)), whereas the other two S(1) = S(2) = (5)/(2) systems, viz. [Fe(2)(III)(HL)(2)(&mgr;-OH)(2)](ClO(4))(2) (1) and the Fe(III)Mn(II) complex (5), exhibit weak antiferromagnetic exchange coupling with J = -4.5 cm(-1) (1) and -1.8 cm(-1) (5). The Fe(III)Ni(II) (3) and Fe(III)Co(II) (4) systems, however, exhibit weak ferromagnetic behavior with J = 1.7 cm(-1) (3) and 4.2 cm(-1) (4). The iron(III) center in 2-5 exhibits quasi-reversible redox behavior between -0.44 and -0.48 V vs Ag/AgCl associated with reduction to iron(II). The oxidation of cobalt(II) in 4 occurs quasi-reversibly at 0.74 V, while both nickel(II) and manganese(II) in 3 and 5 undergo irreversible oxidation at 0.85 V. The electrochemical reduction of 6 leads to the generation of 4.