Note on internal ballistics with composite charge

In the present note, it has been pointed out that under certain conditions the internal ballistics of orthodox guns during the first stage of burning of a composite charge can be obtained with he help of Hunt-Hinds tables

Neutrino Mass Matrices in Models with Horizontal Symmetries

We have studied the most general neutrino mass matrices in models with SU(2) and SU(3) horizontal symmetries. Without going into the details of the models it is possible to write down the effective operators, which predict the structure of the Majorana neutrino mass matrices. Unlike other extensions of the standard model, the structure is now independent of the effective Yukawa couplings and depends entirely on the Higgs which gives mass to the other fermions. In the case of SU(3) symmetries the lowest dimensional operators are forbidden requiring a low mass scale for lepton number violation.Comment: 11 pages latex file, a few references added in 2nd versio

Surface plasmon resonance imaging detection of silver nanoparticle-tagged immunoglobulin

This article is available open access through the publisher’s website at the link below. Copyright @ 2011 The Royal Society.The detection sensitivity of silver nanoparticle (AgNP)-tagged goat immunoglobulin G (gIgG) microarrays was investigated by studying surface plasmon resonance (SPR) images captured in the visible wavelength range with the help of a Kretchmann-configured optical coupling set-up. The functionalization of anti-gIgG molecules on the AgNP surface was studied using transmission electron microscopy, photon correlation measurements and UV–visible absorption spectroscopy. A value of 1.3 × 107 M−1 was obtained for the antibody–antigen binding constant by monitoring the binding events at a particular resonance wavelength. The detection limit of this SPR imaging instrument is 6.66 nM of gIgG achieved through signal enhancement by a factor of larger than 4 owing to nanoparticle tagging with the antibody.The European Commissio

Electron charge transport in non-peripherally substituted copper phthalocyanine

Bottom-gate, bottom-contact organic thin film transistors (OTFTs) were fabricated using solvent soluble copper-1,4,8,11,15,18,22,25-octakis(hexyl)phthalocyanine as the active semiconductor layer. The compound was deposited as 70 nm thick spin-coated films onto gold source-drain electrodes supported on octadecyltrichlorosilane treated 250 nm thick SiO2 gate insulator. The analysis of experimental results showed the n-type field effect behaviour. Devices annealed at 100 oC under vacuum were found to exhibit the field-effect mobility of 0.0989 cm2 V-1 s-1, with an on/off current modulation ratio of ∼106, a reduced threshold voltage of 0.7 V and a sub-threshold swing of 2.12 V decade-1. The variations in surface morphology of the devices are found reflected considerably in the electrical measurements. The device contact resistance was found to be decreased as the gate bias increased and also with the annealing

Hybrid phthalocyanine/lead sulphide nanocomposite for bistable memory switches

Asimple, one-step method is employed to produce, at room temperature, a single layer of an organicinorganic nanocomposite containing non-aggregated lead sulphide (PbS) quantum dots (QDs) embedded in a 130 nmthick solution processed film of the organic semiconductor 6PcH2 (metal-free, non-peripherally substituted octahexyl phthalocyanine) on indium tin oxide. The mean size of PbS QDs is found from x-ray diffraction and transmission electron microscopy techniques to be much smaller than the Bohr radius. Further evidence of the quantum confinement effect is provided by a blue shift in the absorption spectrum and the increased band gap of 1.95 eV with respect to bulk PbS. The current–voltage characteristics of the hybrid and pristine 6PcH2 films, both in a sandwich configuration with the aluminium top electrode, exhibit bistable switching type hysteresis. The on-off ratio of the nanocomposite device is at least three orders of magnitude higher than that for 6PcH2 organic films, while both devices operate at a very low bias voltage of 0.5 V. The inclusion of the PbS QDs into the 6PcH2 film enhances the conductivity by nearly two orders of magnitude over that of a comparable pristine 6PcH2 film due to the formation of a charge transfer complex with PbS QDs and 6PcH2 acting as acceptors and donors of electrons, respectively

Rotation measurement with the use of a pulsed Er-doped fiber laser with integrated optic circuit: Proposal, simple theory, and experiment

We propose a novel pulsed fiber laser rotation sensor with a LiNbO 3 integrated optic circuit, Sagnac fiber loop, Er-doped fiber, and semiconductor pumping lasers. A simple analysis is completed and the output equation is derived. The variance of the output pulse when rotation occurs is also analyzed. In addition, we also conducted a related experiment for rotation measurement. When the gain of the fiber amplifier is over the round-trip loss and the phase modulation frequency satisfies the total round-trip time, this optical system produces the laser emission in a pulse state. The rotation rate is measured from the shift of the peak position of the output pulse. It is shown that the resolution of rotation measurement increases if we use a smaller phase modulation depth. But the sharpness of the optical pulse must be maintained by reducing the losses (or increasing the gain of optical amplifier) in the whole optical system. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 15: 311–315, 1997.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/35041/1/12_ftp.pd

Channel Length Dependent Characterisations of Organic Thin Film Transistors with Solution Processable Gadolinium Phthalocyanine Derivatives

Spin-coated 52-nm-thick films of newly synthesised gadolinium liquid crystalline bisphthalocyanine sandwich (GdPc 2) complexes with octyl chains non-peripheral positions have been successfully employed as active layers for bottom-gate organic field effect transistors having both short (5μm) and long (20μm) channels. The scaling down of the channel length (L) decreases the field effect mobility due to the increase in the contact resistance between the gold electrodes and the GdPc 2 semiconducting layer. Values of on–off ratio and sub-threshold voltage swing are higher nearly one order of magnitude for L=5μm than those for L=20μm

Newly Synthesised Gadolinium bis-Phthalocyanine Sandwich Complex: Ambipolar Organic Semiconductor

Time of flight (TOF) photocurrent transient studies on 5µm thick solution processed films of novel non-peripherally octa-octyl-substituted liquid crystalline gadolinium bis-1,4,8,11,15,18,22,25-octakis(octyl) phthalocyanines (8GdPc2) provide a quantitative analysis of the intrinsic ambipolar charge transport relative to mesomorphic structure of this lanthanide compound. Characteristic liquid crystalline phases of these molecules have been identified from differential scanning calorimetry supported by observation from the UV-visible absorption, showing crystal-columnar mesophase and columnar mesophase-isotropic liquid transitions at 64.2°C and 162°C, respectively. The TOF carrier mobility is found to be structure dependent and highest values of 4.73×10−6m2/Vs and 1.6×10−6m2/Vs have been estimated for hole and electron mobilities for hexagonally packed, columnar structures of the spin-coated films. These results are exploitable for development of single molecule based all organic complimentary analogue and digital circuits with tunable field effect performance

"The fruits of independence": Satyajit Ray, Indian nationhood and the spectre of empire

Challenging the longstanding consensus that Satyajit Ray's work is largely free of ideological concerns and notable only for its humanistic richness, this article shows with reference to representations of British colonialism and Indian nationhood that Ray's films and stories are marked deeply and consistently by a distinctively Bengali variety of liberalism. Drawn from an ongoing biographical project, it commences with an overview of the nationalist milieu in which Ray grew up and emphasizes the preoccupation with colonialism and nationalism that marked his earliest unfilmed scripts. It then shows with case studies of Kanchanjangha (1962), Charulata (1964), First Class Kamra (First-Class Compartment, 1981), Pratidwandi (The Adversary, 1970), Shatranj ke Khilari (The Chess Players, 1977), Agantuk (The Stranger, 1991) and Robertsoner Ruby (Robertson's Ruby, 1992) how Ray's mature work continued to combine a strongly anti-colonial viewpoint with a shifting perspective on Indian nationhood and an unequivocal commitment to cultural cosmopolitanism. Analysing how Ray articulated his ideological positions through the quintessentially liberal device of complexly staged debates that were apparently free, but in fact closed by the scenarist/director on ideologically specific notes, this article concludes that Ray's reputation as an all-forgiving, ‘everybody-has-his-reasons’ humanist is based on simplistic or even tendentious readings of his work