Highlights of 10th plasma chemistry meeting

The chemical structure is given of a film formed by plasma polymerization from pyridine monomers. The film has a hydrophilic chemical structure, its molecular weight is 900, and the molecular system is C55H50N10O3. The electrical characteristics of a plasma polymerized film are described. The film has good insulating properties and was successfully applied as video disc coating. Etching resistance properties make it possible to use the film as a resist in etching. The characteristics of plasma polymer formed from monomers containing tetramethyltin are discussed. The polymer is in film form, displays good adhesiveness, is similar to UV film UV 35 in light absorption and is highly insulating

Hydrophobic coating of solid materials by plasma-polymerized thin film using tetrafluoroethylene

Glass slides were coated with plasma-polymerized tetrafluoroethylene films of different thickness using the glow discharge technique in a tube-shaped chamber, and the plasma conditions, film growth rates, light permeability of the polymer films, and particle bond strength in the polymer films were studied. Ashed sections of mouse organs and ashed bacillus spores were also coated to give them hydrophobic treatment without damaging their shapes or appearance. The hydrophobic coating of the specimens was successful, and the fine ash patterns were strongly fixed onto the glass slides, making permanent preparations

Geomagnetic field variations at the equatorial electrojet station in Sri Lanka, Peredinia

The paper discusses the variations of the horizontal (<i>H</i>), vertical (<i>Z</i>) and eastward (<i>Y</i>) components of the geomagnetic field at Peredinia (PRD), an electrojet station in Sri Lanka, with the time of the day, season, sudden commencement (SSC) and during geomagnetic storms. The daily variation of <i>H</i> showed a large peak around midday. The daily variation of <i>Z</i> appeared to be almost a time gradient curve of the daily variation of <i>H</i>, showing a maximum around 09:00 LT (75° EMT) when the <i>H</i> field was increasing fastest and not at noon when Δ <i>H</i> was the maximum. Storm time variation of <i>H</i> resembled the variation of the <i>D<sub>st</sub></i> index but that of <i>Z</i> showed a large minimum about 2-3h before the time of minimum <i>D<sub>st</sub></i> or at the time of maximum time gradient of <i>D<sub>st</sub></i> variation. These features are compared with corresponding variations at the equatorial stations Trivandrum (TRD) in India, and remarkable similarity in all observations is noticed at PRD and TRD. It is suggested that the observed abnormal features of <i>Z</i> variations at electrojet stations in India-Sri Lanka are due to (i) direct effect of the ionospheric electrojet current (ii) the induction effect of the image current by the average spatially extended conductivity region and (iii) the induction current in the local subsurface conductor. It is suggested that the conductor responsible for the observed features in <i>Z</i> in India and Sri Lanka has to have extended spatial domain to latitudes well south of India, rather than confined to narrow Palk Strait

Semiconductor effective charges from tight-binding theory

We calculate the transverse effective charges of zincblende compound semiconductors using Harrison's tight-binding model to describe the electronic structure. Our results, which are essentially exact within the model, are found to be in much better agreement with experiment than previous perturbation-theory estimates. Efforts to improve the results by using more sophisticated variants of the tight-binding model were actually less successful. The results underline the importance of including quantities that are sensitive to the electronic wavefunctions, such as the effective charges, in the fitting of tight-binding models.Comment: 4 pages, two-column style with 2 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/index.html#jb_t

Protein-crystal growth experiment (planned)

To evaluate the effectiveness of a microgravity environment on protein crystal growth, a system was developed using 5 cubic feet Get Away Special payload canister. In the experiment, protein (myoglobin) will be simultaneously crystallized from an aqueous solution in 16 crystallization units using three types of crystallization methods, i.e., batch, vapor diffusion, and free interface diffusion. Each unit has two compartments: one for the protein solution and the other for the ammonium sulfate solution. Compartments are separated by thick acrylic or thin stainless steel plates. Crystallization will be started by sliding out the plates, then will be periodically recorded up to 120 hours by a still camera. The temperature will be passively controlled by a phase transition thermal storage component and recorded in IC memory throughout the experiment. Microgravity environment can then be evaluated for protein crystal growth by comparing crystallization in space with that on Earth

High Angular Resolution, Sensitive CS J=2-1 and J=3-2 Imaging of the Protostar L1551 NE: Evidence for Outflow-Triggered Star Formation ?

High angular resolution and sensitive aperture synthesis observations of CS ($J=2-1$) and CS ($J=3-2$) emissions toward L1551 NE, the second brightest protostar in the Taurus Molecular Cloud, made with the Nobeyama Millimeter Array are presented. L1551 NE is categorized as a class 0 object deeply embedded in the red-shifted outflow lobe of L1551 IRS 5. Previous studies of the L1551 NE region in CS emission revealed the presence of shell-like components open toward L1551 IRS 5, which seem to trace low-velocity shocks in the swept-up shell driven by the outflow from L1551 IRS 5. In this study, significant CS emission around L1551 NE was detected at the eastern tip of the swept-up shell from $V_{\rm{lsr}}$ = 5.3 km s$^{-1}$ to 10.1 km s$^{-1}$, and the total mass of the dense gas is estimated to be 0.18 $\pm$ 0.02 $M_\odot$. Additionally, the following new structures were successfully revealed: a compact disklike component with a size of $\approx$ 1000 AU just at L1551 NE, an arc-shaped structure around L1551 NE, open toward L1551 NE, with a size of $\sim 5000$ AU, i.e., a bow shock, and a distinct velocity gradient of the dense gas, i.e., deceleration along the outflow axis of L1551 IRS 5. These features suggest that the CS emission traces the post-shocked region where the dense gas associated with L1551 NE and the swept-up shell of the outflow from L1551 IRS 5 interact. Since the age of L1551 NE is comparable to the timescale of the interaction, it is plausible that the formation of L1551 NE was induced by the outflow impact. The compact structure of L1551 NE with a tiny envelope was also revealed, suggesting that the outer envelope of L1551 NE has been blown off by the outflow from L1551 IRS 5.Comment: 29 pages, 12 figures, Accepted for Publication in the Astrophysical Journa

Raman signatures of classical and quantum phases in coupled dots: A theoretical prediction

We study electron molecules in realistic vertically coupled quantum dots in a strong magnetic field. Computing the energy spectrum, pair correlation functions, and dynamical form factor as a function of inter-dot coupling via diagonalization of the many-body Hamiltonian, we identify structural transitions between different phases, some of which do not have a classical counterpart. The calculated Raman cross section shows how such phases can be experimentally singled out.Comment: 9 pages, 2 postscript figures, 1 colour postscript figure, Latex 2e, Europhysics Letters style and epsfig macros. Submitted to Europhysics Letter