[en] Contemporary marketing measures focus on recruiting new customers as a means of boosting sales. As the share of the market occupied by natural gas increases, the more probable it is that there will be dissatisfied customers who are prepared to switch to other energy sources. Systematic customer care measures are therefore a necessity ServicePro is a customer care concept that has been developed in response to this need. Its three modules are technical, contractual and general customer care. Practical local implementation is assisted by database software and a manual containing tools and examples. Customer care activities also strengthen customer relations and improve the gas utility's image. (au)

[en] Some of the difficulties encountered in the approximation of Green's functions are reviewed with particular emphasis on the self-consistent polarization propagator. Some new basic theorems are presented, involving a general procedure, which lead to both a derivation and alternate prescriptions for the computations. The authors results establish a natural relationship between hermiticity, completeness, non-redundance of operator manifolds with stationarity and killer conditions. (Auth.)

[en] Oxygen is quantitatively separated from oxygen-nitrogen gas mixtures by gas chromatography and adsorbed at a molecular sieve at liquid nitrogen temperature. After the desorption of oxygen from the molecular sieve the liberated oxygen can be converted to carbon dioxide. This is achieved by heating a graphite disk through focusing the radiation of a halogen lamp onto its surface. It is shown that the isotopic composition of oxygen is not altered during the gas chromatographic separation and the following adsorption which is of interest for direct mass spectrometric isotope ratio measurements of oxygen. (author)

[en] The family of all Hartree-Fock-Bogoliubov (HFB) states for a given set of r isosopin-spin orbitals form a set of coherent states. The set of antisymmetrized geminal power (AGP) states for a given set of r isospin-spin orbitals form a set of charge-projected coherent states, with the number of particles n as the ''charge'' and the HFB coherent state as the generating function. Both these coherent states are associated with the group SO(2r). The approximate time evolution of the system generated by restricting the quantum mechanical evolution to the family of HFB and AGP coherent states is described as a classical dynamics with the energy of the coherent state as hamiltonian function. The phase space is isomorphic to the coset space SO(2r)/U(r). The random phase approximation based on HFB and AGP states is derived by considering the harmonic approximation to the hamiltonian function. This work generalizes the group theoretical approaches to Hartree-Fock, and time-dependent Hartree-Fock theory by the use of non-number-conserving (HFB) and correlated (AGP) states. (orig.)

[en] In situ phase-modulated ellipsometry was employed to monitor the nucleation and growth processes of diamond thin films fabricated by chemical vapor deposition. The effective extinction coefficient (k) at 1.96 eV was used as a basis for dividing the deposition process into intervals. The film growth was aborted at various k values yielding diamond film samples that represent snapshots of the growth process at different stages. Ex situ characterization of the films was performed using Raman spectroscopy, scanning electron microscopy, and x-ray diffraction. The results indicate that the diamond film deposition process consists of various stages in which the crystalline quality, the net compressive stress, and the relative amount of non-sp³ carbon follow different trends. A correlation between the effective k value measured in situ and the film microstructure characterized ex situ was established which enables the monitoring of the diamond film growth process in real time

[en] We use deep and wide near infrared (NIR) imaging from the Palomar telescope combined with DEEP2 spectroscopy and Hubble Space Telescope (HST) and Chandra Space Telescope imaging to investigate the nature of galaxies that are red in NIR colors. We locate these 'distant red galaxies' (DRGs) through the color cut (J - K)_vega > 2.3 over 0.7 deg², where we find 1010 DRG candidates down to K_s = 20.5. We combine 95 high quality spectroscopic redshifts with photometric redshifts from BRIJK photometry to determine the redshift and stellar mass distributions for these systems, and morphological/structural and X-ray properties for 107 DRGs in the Extended Groth Strip. We find that many bright (J - K)_vega > 2.3 galaxies with K_s < 20.5 are at redshifts z < 2, with 64% between 1 < z < 2. The stellar mass distributions for these galaxies is broad, ranging from 10⁹ - 10¹² M_· , but with most z > 2 systems massive with M_* > 10¹¹ M_·. HST imaging shows that the structural properties and morphologies of DRGs are also diverse, with the majority elliptical/compact (57%), and the remainder edge-on spirals (7%), and peculiar galaxies (29%). The DRGs at z < 1.4 with high quality spectroscopic redshifts are generally compact, with small half-light radii, and span a range in rest-frame optical properties. The spectral energy distributions for these objects differ from higher redshift DRGs: they are bluer by one magnitude in observed (I - J) color. A pure IR color selection of high redshift populations is not sufficient to identify unique populations, and other colors, or spectroscopic redshifts are needed to produce homogeneous samples

[en] This paper describes the Maryland-Magellan Tunable Filter (MMTF) on the Magellan-Baade 6.5 m telescope. MMTF is based on a 150 mm clear aperture Fabry-Perot (FP) etalon that operates in low orders and provides transmission bandpass and central wavelength adjustable from ∼5 A to ∼15 A and from ∼5000 A to over ∼9200 A, respectively. It is installed in the Inamori Magellan Areal Camera and Spectrograph and delivers an image quality of ∼0.''5 over a field of view of 27' in diameter (monochromatic over ∼10'). This versatile and easy-to-operate instrument has been used over the past three years for a wide variety of projects. This paper first reviews the basic principles of FP tunable filters, and then provides a detailed description of the hardware and software associated with MMTF and the techniques developed to observe with this instrument and reduce the data. The main lessons learned in the course of the commissioning and implementation of MMTF are highlighted next, before concluding with a brief outlook on the future of MMTF and of similar facilities which are soon coming on line.

[en] The supersonic short-pulse helium atomic beam and its metastables were studied. A pulsed high-density helium atomic beam was ejected from a nozzle, collimated by a skimmer and then flowed through a penning-type discharge device. After discharging, the metastable density of the pulsed helium atomic beam was up to 1.24x10¹¹ cm^-3. Excellent symmetry of atomic beam profile was obtained. The deviation of angle of the atomic beam with respect to the axis was less than 0.14 deg.. The mean diffusion angle of the pulsed beam was 4 deg., and a mean velocity of atomic beam was up to 1350 ms^-1. Laser induced fluorescence of metastable atoms has been studied

[en] We demonstrate estimating the total infrared luminosity, L(TIR), and star formation rates (SFRs) of star-forming galaxies at redshift 0 < z < 2.8 from single-band 24 μm observations, using local spectral energy distribution (SED) templates without introducing additional free parameters. Our method is based on characterizing the SEDs of galaxies as a function of their L(TIR) surface density, which is motivated by the indications that the majority of IR luminous star-forming galaxies at 1 < z < 3 have extended star-forming regions, in contrast to the strongly nuclear concentrated, merger-induced starbursts in local luminous and ultraluminous IR galaxies. We validate our procedure for estimating L(TIR) by comparing the resulting L(TIR) with those measured from far-IR observations, such as those from Herschel in the Extended Chandra Deep Field South (ECDFS) and Hubble Deep Field North (HDFN), as well as L(TIR) measured from stacked far-IR observations at redshift 0 < z < 2.8. Active galactic nuclei were excluded using X-ray and 3.6-8.0 μm observations, which are generally available in deep cosmological survey fields. The Gaussian fits to the distribution of the discrepancies between the L(TIR) measurements from single-band 24 μm and Herschel observations in the ECDFS and HDFN samples have σ < 0.1 dex, with ∼10% of objects disagreeing by more than 0.2 dex. Since the 24 μm estimates are based on SEDs for extended galaxies, this agreement suggests that ∼90% of IR galaxies at high z are indeed much more physically extended than local counterparts of similar L(TIR), consistent with recent independent studies of the fractions of galaxies forming stars in the main-sequence and starburst modes, respectively. Because we have not introduced empirical corrections to enhance these estimates, in principle, our method should be applicable to lower luminosity galaxies. This will enable use of the 21 μm band of the Mid-Infrared Instrument on board the James Webb Space Telescope to provide an extremely sensitive tracer of obscured SFR in individual star-forming galaxies across the peak of the cosmic star formation history.

[en] Diamond has many potential electronic applications, but the diamond seeding methods are generally harsh on the substrates rendering them unsuitable for integration in electronics. We report a non-abrasive, scalable and economic process of diamond film seeding using kitchen-wrap polyethylene employing hot filament chemical vapour reaction of H₂S/CH₄/H₂ gas mixtures on Cu substrates. The fabricated diamond films were characterized with scanning electron microscopy, transmission electron microscopy and Raman spectroscopy, which confirm that the deposited film consists of a microcrystalline diamond of size in the range 0.5-1.0 μm. The synthesized diamond films exhibit a turn-on field of about 8.5 V μm^-1 and long-term stability. Diamond film synthesis using polyethylene will enable the integration of diamond heat sinks into high-power and high-temperature electronic devices.