bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrate Reduction by Redox-Modified Smectites Exchanged with Chitosan
Authors: Pentráková Martin , PentráKová Linda , Radian Adi , Mishael Yael G. , Stucki Joseph W.
Published: February 2015

The presence of nitrate and other redox-active anionic contaminants in terrestrial ecosystems poses a significant risk to humans and other forms of life on Earth. The purpose of the present study was to test a potential in situ system, using poly-(D) glucosamine (chitosan) adsorbed to mineral surfaces under redox-active conditions in order to degrade nitrate to lower oxidation states. Chitosan is a linear polysaccharide derived from the chitin found in the shells of shrimp and other shellfish. Five different loadings of chitosan (0, 0.075, 0.25, 0.50, and 1.0 g/L; labeled C0, C1, C2, C3, and C4, respectively) were adsorbed to ferruginous smectite (SWa-1) to form chitosan-SWa-1 composites (CSC) in the pH range 5.8–4. The CSC was then reduced by Na2S2O4 in a citrate-bicarbonate buffered dispersion and washed free of excess salts under inert-atmosphere conditions. Upon addition of the nitrate, the solution pH remained slightly acidic, ranging from 5.5 to 4.7. Samples were analyzed for Fe(II) content, reacted with a NaNO3 solution, and then re-analyzed for structural Fe(II) content. Supernatant solutions were analyzed for nitrate, nitrite, and ammonium. In samples C1 to C4, extensive concentrations of nitrite were observed in the supernatants with a corresponding increase in the reoxidation of structural Fe(II), proving that a coupled redox reaction had occurred between the nitrate and the structural Fe in the clay mineral. The most efficient loading, defined as the largest percentage of adsorbed nitrate reduced to nitrite, occurred in sample C1. The total amount of nitrate reduced and Fe(II) reoxidized followed the trend 0 = C0 < C2 < C3 < C4 ≈ C1. Chitosan showed the potential to reverse the surface charge of constituent clay minerals, thereby enabling the CSC to remove nitrate anions from aqueous mineral systems via redox reactions with structural Fe(II) in clay minerals.
F.I.S.E Small Gallery, Community art project in Hungary
Authors: Wolstenholme Neil , Ráthonyi Kinga
Published: February 2015

Over the past seventeen years the authors have been working together, creating and promoting community art projects. The main objective of these works has always been to shape the users visual environment, with maximum involvement of the local community. Participation in the projects has allowed people to share creative thoughts, production, ideas, and communicate. These have taken place on site in a communal environment which respects and appreciates the individual. People are free to work/talk/look or just be there. The following visual essay documents a recently completed project.
Personal images, collective journeys: Media and memory in I Travel Because I Have to, I Come Back Because I Love You
Authors: de Luca Tiago
Published: February 2015

This article intends to explore the intersections of personal and cultural memory as expressed and mediated by the Brazilian film Viajo porque preciso, volto porque te amo/I Travel Because I Have to, I Come Back Because I Love You by Karim Aïnouz and Marcelo Gomes (2009). Crossing the generic boundaries of the road movie, the essay film and observational documentary, I Travel Because I Have to, I Come Back Because I Love You stitches together images shot on Super-8, 35mm, 16mm, mini-DVs and even still photographs, all of which testifies to the directors’ own personal memories. The film further appropriates literary and filmic references that together situate it within the vast terrain of cultural memory associated with the backlands (the sertão) in the Brazilian imaginary. This article aims to excavate this kaleidoscope of personal and collective memories, and argues that their reflection provokes meditations on history, culture and the passing of time.
The long smouldering night: Sex, songs and the desi feminist noir
Authors: Shandilya Krupa
Published: February 2015

This article argues that the films Ishqiya/Romance (Chaubey, 2010) and Dedh Ishqiya/Romance 1.5 (Chaubey, 2014) by Abhishek Chaubey, represent a new genre of films, namely the ‘desi feminist noir’, which is characterized by all the elements of film noir, such as the murky distinction between good and evil, the lawlessness of the streets and the femme fatale. However, in these films the figure of the femme fatale is used to forward explicitly feminist trajectories of love, romance and sex. I give a brief history of romantic coupling in Hindi cinema, and analyse the films’ departure from these articulations of romance. Next, I focus on a song sequence from each of the films to explicate the desi feminist femme fatale’s subversion of the romantic conventions of the Hindi film song and her inauguration of a new aesthetic of romance. In conclusion, I consider the implications of this new genre for Bollywood cinema.
Down the rabbit hole: Five theses on the subject of retreat in the time of global capital
Authors: Lawless Kate
Published: February 2015

This article considers the role of retreat in the time of global capital through an exploration of some of the major themes arising during the Banff residency, The Retreat: A position of dOCUMENTA(13), held in August 2012. These themes include the retreats of mastery, subjectivity, the protagonist, historical time, and the return of totality in response to the so-called crisis of capitalism.
Finding a fire before it flames
Authors: Gomez Jason
Published: February 2015

A brief history on select environmental insignia.
'The spectre of form: Letters from an absent sovereign'
Authors: Pendakis Andrew
Published: February 2015

This short essay will respond to a photographic series produced by artist Maria Whiteman during her Studio Time residency at Banff. These photos consist of two diptychs each of which contrasts an image of the gardens of Versailles with one taken of a desolately mined oil sand's landscape; a single fifth photograph reveals an unfinished road, a major future piece in the oil infrastructure of Alberta, stretching off into an empty horizon. In the proposed article I read these photos as provocative reflections on the historical fate of sovereign reason; the issues they raise pertain to that which remains vital or stillborn in the ability of the human mind to shape and alter its environment and future. The gardens of Versailles have historically functioned as emblems of a highly aestheticized sovereignty (both political and epistemological); they have more recently become a shorthand for the violence of 'Enlightenment' reason, for the brutal capture of nature by mathematics and logic. Whiteman's series complicates this contemporary reading: there is a verdure, stillness and elegance to these re-contextualized gardens, one which at the same time does not discount the possibility that the desertified zone of extraction is simply a direct extension of rationalist control gone awry. I will argue that there is a quiet call within these photos to a return to form, to a political humanism of the willed effect and to the strength and vigour of a now almost antiquated political act. A nostalgia, however, that at the same time utterly concedes the way in which contemporary politics and economics are both forms of the same tragic fantasy of centrality, the bad hubris of anthropocentrism.
Ownership and culture
Authors: Szeman Imre
Published: February 2015

Even in an era when images have become omnipresent, art practices continue to carry out critique of a kind that is invaluable to our comprehension of our social and political condition. Amongst the most significant issues art and cultural production more generally draw attention to, are the operations of ownership and property, especially in connection to culture. Property continues to name a limit and blockage in our current social configuration. How, why and what are the consequences of property today? And how might we retreat from property through the articulation of a new social commons?
Afterword
Authors: Jim Alice Ming Wai
Published: February 2015

Afterword for special issue of PUBLIC on The Retreat: A Position of dOCUMENTA (13) reflects on author's participation in the Banff residency through personal vignettes and keywords that connect essays in the issue. The second half of the article examines Hong Kong-born Canadian artist Yam Lau's recent projection-based art installation. It considers contemporary implications for retreat as model in relation to the historic literati retreat of seventeenth century China and the Buddhist metaphor of Indra's Net, arguing the impossibility of both profound withdrawal and retreat into indifference.
..., ..., ..., ..., ..., ..., (Exile)
Authors: Boisjoly Raymond
Published: February 2015

Exploring the politics of representation, … … … … … … (Exile) is comprised of abstracted film stills created through the productive misuse of technology. Sourced from Kent Mackenzie's film, The Exiles (1961), These images are made by scanning the film while it is being played on a portable digital video player: turning moving images into still ones. The documentary style film follows a small group of Indigenous people living in Los Angeles. Over a twelve-hour period, the film records their candid discussions of home, community and future.
The Conspiracy Called Movement
Authors: Berardi Franco 'Bifo'
Published: February 2015

In this essay Berardi proclaims that we need to llimit the possibilities for retreat, rather than expand them. Looking optimistically to social movement and a rising collective consciousness against exploitation and austerity, Bifo calls for the generation of "a common sphere of sensibility" that will inform a politics that serves the interests of all, rather than just a few. For Bifo, a technology-induced retreat is at least partially to blame: this is the techno-alienation experienced by today's cognitive labourers, who are also "the first generation of people who have learned more words from a machine than from their mother."
‘Take the toys from the boys’: Gender, generation and anarchist intent in the work of Poison Girls
Authors: Cross Rich
Published: February 2015

Alongside Crass, Poison Girls were the central catalysts for the emergent anarcho-punk movement of the late 1970s and early 1980s. Although the work of Crass has been subject to an increasing degree of retrospective scrutiny in recent years, the singular contribution of Poison Girls to the anarcho-punk rubric has remained largely unexplored. Poison Girls shared the anarchist impulses of Crass, but refracted their anti-capitalist perspectives through a distinctive anarcha-feminist prism. Reflected throughout the canon of the band’s work was a twin focus on the politics of gender and of generation which was arguably unique amongst their punk contemporaries. After a short and intensive period of close collaboration with Crass, Poison Girls opted for renewed independence and (as the wider anarchist punk movement expanded and diversified) began to explore a very different approach to the practice of being an anarchist band from the model established by Crass. Willing to break with the ‘shibboleths’ of anarchist punk, Poison Girls nevertheless retained a strong fidelity to its underlying principles even as they moved away from its more stringent, ‘outsider’ DIY assumptions. Poison Girls’ own punk practice provides an illuminating counter-point to the experience of Crass, and puts into sharp relief the tensions raised by the attempt to be anarchist interlopers in the musical mainstream.
Making sense of punk in Cuba/making sense of Cuba through punk
Authors: Astley Thomas
Published: February 2015

Rock music in its broadest definition, though still potentially problematic, has grown exponentially in contemporary Cuba, particularly since the economic and social crises of the 1990s. However, the subgenre distinctions that make sense of rock music in an Anglo-American context are not quite so apposite in defining a rock culture in Cuba that is happy to meld subgenres together with elements of Cuban traditional music, in a continuation of the process of ‘transculturaltion’, which many interpret as a founding element of Cuban cultural identity. This article, then, begins with a comment on the ways in which Cuba has made sense of a culturally loaded term such as punk. For the small but significant punk population on the island, many of the aesthetic elements of punk they utilize may serve to ostracize them from both the state and other subcultural groups. However, because of this process of ‘transculturation’, many of these punk traits are used to reflect a sense of contemporary Cuban cultural identity. This article examines the use of ‘classical’ punk cultural motifs of appropriation of cultural symbols, DIY aesthetic, destruction and bricolage in the work of Cuban punk band Porno Para Ricardo, to address the ways in which punk might be used to make sense of Cuba.
The Space Density of Magnetic and Non-magnetic Cataclysmic Variables, and Implications for CV Evolution
Authors: Pretorius M. L.
Published: February 2015

We present constraints on the space densities of non-magnetic and magnetic cataclysmic variables, and discuss some implications for models of the evolution of CVs. The high predicted non-magnetic CV space density is only consistent with observations if the majority of these systems are extremely faint in X-rays. The data cannot rule out the very simple model where long-period IPs evolve into polars and account for the entire short-period polar population. The fraction of
WDs that are strongly magnetic is not significantly higher for CV primaries than for isolated WDs. Finally, the space density of IPs is high enough to explain the bright, hard X-ray source population seen in the Galactic Centre.
Simultaneous UBVRI Observations of the AE Aquarii Blobs
Authors: Latev G. , Zamanov R. , Boeva S. , Stoyanov K.
Published: February 2015

We summarize the results of our study of the cataclysmic variable AE Aqr on the basis of simultaneous UBV RI observations. For the flares, we estimated the average risetime of about 300 sec, and colours (U−B)0~1.1 and (B−V )0~0.1. We also calculated temperatures, sizes, masses and expansion velocities of a few individual fireballs. In a single night (16.08.2012), we detected ~ 8 min quasi-periodic modulation.
Model Atmosphere Spectrum Fit to the Soft X-Ray Outburst Spectrum of SS Cyg
Authors: Suleimanov V. F. , Mauche C. W. , Zhuchkov R. Ya. , Werner K.
Published: February 2015

The X-ray spectrum of SS Cyg in outburst has a very soft component that can be interpreted as the fast-rotating optically thick boundary layer on the white dwarf surface. This component was carefully investigated by Mauche (2004) using the Chandra LETG spectrum of this object in outburst. The spectrum shows broad ( ≈5 °A) spectral features that have been interpreted as a large number of absorption lines on a blackbody continuum with a temperature of ≈250 kK. Because the spectrum resembles the photospheric spectra of super-soft X-ray sources, we tried to fit it with high gravity hot LTE stellar model atmospheres with solar chemical composition, specially computed for this purpose. We obtained a reasonably good fit to the 60–125 °A spectrum with the following parameters: Teff = 190 kK, log g = 6.2, and NH = 8 · 1019 cm−2, although at shorter wavelengths the observed spectrum has a much higher flux. The reasons for this are discussed. The hypothesis of a fast rotating boundary layer is supported by the derived low surface gravity.
SS Cygni Revisited
Authors: Smith R. C. , Echevarrıa J. , Hernandez J. V. , Szkody P.
Published: February 2015

New spectroscopic and photometric observations of SS Cygni, the brightest dwarf nova system, have been obtained, with the aim of mapping starspots on the surface of the secondary star. Four nights of echelle spectroscopy in quiescence have been obtained using the 2.2-m telescope at San Pedro Martir (Mexico) in August 2012 and another two nights at the 3.5-m telescope at Apache Point Observatory, USA, in September 2012, but these data are still being reduced. Simultaneous CCD photometry was also obtained at the two sites, and the Mexican photometry was extended into the subsequent long outburst. This presentation reveals some interesting photometric behaviour in that outburst, but further data will be necessary before the nature of the behaviour can be determined.
Study of Photometric Variability of Selected SU UMa Dwarf Novae
Authors: Voloshina I. , Metlov V.
Published: February 2015

In this work we present time-resolved photometry of several poorly-studied dwarf novae during recent superoutbursts. Observations were made with a CCD, mounted on 50- and 60-cm telescopes of the Sternberg Astronomical Institute in Crimea in April - May and October 2012 and June - July 2013. Superhumps were detected in light curves of all the dwarf novae. The amplitudes and periods of detected light variations were calculated. Superhumps evolution was also followed up for all systems and classification is improved.
Superoutburst of a New Sub-Period-Minimum Dwarf Nova CSS130418 in Hercules
Authors: Chochol D. , Shugarov S. , Katysheva N. , Volkov I. , Zharova A. , Pavlenko E. , Pit N. , Zvagelsky R. , Antoniuk O. , Baklanov A. , Borisov N. , Gabdeev M.
Published: February 2015

Multicolour photometry of a new dwarf nova CSS130418 in Hercules, which underwent superoutburst on April 18, 2013, allow to classified it as a WZ Sge-type dwarf nova. The phase light curves for different stages of superoutburst are presented. The early superhumps were used to determine the orbital period Porb = 64.84(1) minutes, which is shorter than the period minimum ~78 minutes for normal hydrogen-rich cataclysmic variables. We found the mean period of ordinary superhumps Psh = 65.559(1) minutes. The quiescent spectrum is rich in helium, showing double peaked emission
lines of H I and He I from accretion disk, so the dwarf nova is in a late stage of stellar evolution.
The Hidden Population of AM CVn Binaries in the Sloan Digital Sky Survey
Authors: Carter P. J. , Marsh T. R. , Steeghs D. , Breedt E. , Copperwheat C. M. , Gansicke B. T. , Groot P. J. , Nelemans G.
Published: February 2015

We present results from a spectroscopic survey designed to uncover AM Canum Venaticorum (AM CVn) binaries hidden in the photometric database of the Sloan Digital Sky Survey (SDSS). The discovery of only 7 new AM CVns in the observed part of our sample suggests a lower space density than previously predicted. Based on the complete g≤19 sample, we calculate an observed space density for AM CVns of (5 ± 3) × 10−7 pc−3. We also compare the cataclysmic variables (CVs) discovered via this survey to those found in the SDSS spectroscopy, and we discuss SBSS 1108+574, an unusually helium-rich CV that has a spectroscopically confirmed orbital period of 55 minutes, well below the CV period minimum (~80 min). SBSS 1108+574 may represent an AM CVn forming via the ‘evolved CV’ formation channel.
The Recurrent Eclipsing Nova U Sco: A Short Review
Authors: González-Riestra R.
Published: February 2015

U Scorpii is the recurrent nova with the shortest inter-outburst period, only ten years. The last active phase took place at the beginning of 2010, and it provided a large amount of data from both ground-based and space observatories. This paper reviews some of the more relevant recent findings and points out some, still unanswered, questions.
Rotation of the Mass Donors in High-mass X-ray Binaries and Symbiotic Stars
Authors: Stoyanov K. , Zamanov R.
Published: February 2015

Our aim is to investigate the tidal interaction in High-mass X-ray Binaries and Symbiotic stars in order to determine in which objects the rotation of the mass donors is synchronized or pseudosynchronized with the orbital motion of the compact companion. We find that the Be/X-ray binaries are not synchronized and the orbital periods of the systems are greater than the rotational periods of the mass donors. The giant and supergiant High-mass X-ray binaries and symbiotic stars are close to synchronization. We compare the rotation of mass donors in symbiotics with the projected rotational velocities of field giants and find that the M giants in S-type symbiotics rotate on average 1.5 times faster than the field M giants. We find that the projected rotational velocity of the red giant in symbiotic star MWC 560 is v sin i= 8.2±1.5 km.s−1, and estimate its rotational period to be Prot<>/sub = 144 - 306 days. Using the theoretical predictions of tidal interaction and pseudosynchronization, we estimate the orbital eccentricity e = 0.68 − 0.82.
Team work at its best – TAPL and its two domains
Authors: Zollmann Tina , Bock Christoph , Graab Philipp , Abele Rupert
Published: February 2015

The transporter associated with antigen processing (TAPL, ABCB9) is a homodimeric ABC transporter, shuttling cytosolic polypeptides into the lumen of lysosomes energized by ATP hydrolysis. Here we give a short overview of the superfamily of ABC transporters and summarize the current state of knowledge on TAPL in detail. The architecture of TAPL and its substrate specificity are described and we discuss the function of an extra N-terminal transmembrane domain, called TMD0, in respect of subcellular targeting and interaction with proteins, contributing to long-term stability. As TAPL shows – besides a ubiquitous basal expression – an elevated expression in antigen presenting cells, we present models of TAPL function in adaptive immunity.
Self-assembly of zinc(II) tetraaza macrocyclic complex and 1,3,5-cyclohexanetricarboxylic acid
Authors: Lim In-Taek , Choi Ki-Young
Published: February 2015

The self-assembly of [Zn(L)(H
Crystal structure of (E)-3-(4-methoxyphenyl)-1-(thiophen-2-yl)-2- tosylprop-2-en-1-one, C21H18O4S2
Authors: Abdel-Aziz Hatem A. , Ghabbour Hazem A. , Fun Hoong-Kun
Published: February 2015

C21H18O4S2, orthorhombic, Pbca (no. 61), a = 8.2038(3) Å, b = 19.8810(7) Å, c = 24.0661(8) Å, V = 3925.2 Å3, Z = 8, Rgt(F) = 0.0490, wRref(F2) = 0.1426, T = 293 K.
Numerical Solution of a Plane Jet Impingement on an Infinite Flat Surface
Authors: Arora S. , Irfan Nagma
Published: February 2015

In this paper numerical solution of the unsteady plane incompressible viscous jet impinging on to an infinite flat surface are presented for Re=450. In the present study, all calculations have been done by using Dufort Frankel scheme and over relaxation scheme. Result and graphs have been obtained by using MATLAB programming. The obtained results explain the flow of water after exhaling from nozzle and the streamlines and vorticity of flow ofwater after striking with flat infinite surface. The solutions obtained by proposed method indicate that this approach is easy to implement and computationally very attractive and the results of our investigation are in qualitative agreement with those available in the literature [1, 9]. This method is capable of greatly reducing the size of calculations while still maintaining high accuracy of the numerical solution.
Characteristic X-ray Production in Thin Crystals
Authors: Cherns D. , Howie A. , Jacobs M. H.
Published: February 2015

The dependence of the characteristic X-ray production on electron beam orientation is studied using very thin epitaxially grown single crystals. In crystals of Ag and Pd of thickness ~100 Å the L shell yield can change by more than a factor of 2 for small changes in orientation near the [111] direction. Theoretical analysis of the results shows that the different Bloch waves do not produce X-rays independently but that interference effects occur. The significance of these observations is discussed.
The Energy Flow of X-Rays in Germanium Single Crystals
Authors: Gerward L.
Published: February 2015

The energy flow of the X-ray wave fields set up by diffraction in a germanium single crystal has been studied by shadow sharpness measurements. The shadow has been produced by an absorbing wire close to the X-ray entrance surface of the crystal. Intensity profiles have been observed in the wavelength range from 1.541 Å to 0.709 Å, including the K absorption edge of germanium at 1.117 Å. It is shown that the angular divergence of the energy flow is almost independent of the wavelength on each side of the absorption edge. The angular divergence is considerably reduced when passing the absorption edge from the low-energy side to the high-energy side, the thickness of the crystal being kept constant.
A Comparison of Diffuse Scattering by Defects Measured in Anomalous Transmission and Near Bragg Reflections
Authors: Larson Bennett C. , Young F. W.
Published: February 2015

The diffuse scattering from neutron-irradiation-produced defects in copper was measured in anomalous transmission and near the 111 Bragg reflection. The results were related through the theory of Dederichs, and the intensities and forms of the scattering curves obtained from the two measurements were found to be in good agreement over a wide range of defect concentrations and sizes. It was shown that the intercept of a plot of the diffuse scattering intensity Is (q0) vs In (q0) is at q0=e1/2/R for defects of uniform radius R and at q0 ≌1/R0 e for an exponential size distribution of average size R0 .
Ab Initio-Rechnungen zum F2-Molekül/ Different ab-initio calculations for the ground-state and some excited states of the F2-molecule
Authors: Kasseckert E.
Published: February 2015

For the ground-state and the lower lying excited states of the fluorine-molecule VB -CI calculations with Slater-type orbitals and SCF -CI calculations with contracted Gauß-Lobe functions have been carried out. The SCF -CI method yields a fairly good description of the ground-state. But it is rather difficult to decide whether the SCF -CI calculations of the excited states are accurate or not. The discussion of the potential-curves of some higher excited states leads to the conjecture that the experimentally observed orange band-systems may belong to two transitions

1Σg
-→ 1Πu and 1Σu
+ → 1Πg.

But this should be checked in further calculations which must include higher orbitals as basis functions.
On the Statistics of Many Interacting Waves far from Thermal Equilibrium
Authors: Wonneberger W. , Lempert J.
Published: February 2015

The intensity distribution function P(I) for the incoherent superposition of interacting stationary waves far from thermal equilibrium and coupled to many other waves e. g. in active photon and phonon systems is determined analytically for a specific interaction model. The model consists of Nm ⪢ 1 equivalent waves concentrated in a small frequency band which interact through their intensities alone. P{I) refers to Nm′′＜ Nm of these waves. The remaining Nm′=Nm-Nm′′ waves then act as a reservoir. P(l) is shown to be asymptotically given by a Beta-distribution for Nm′⪢ 1. It is found that the interactions thermalize each individual wave which otherwise would be laser like concerning its statistical properties. The photon counting distribution associated with P(l) is also discussed. For Nm′′ comparable to Nm , it can differ significantly from the photon counting distribution of Nm′′ independent thermal waves.
Notizen: Desorientierung von optisch ausgerichteten Na-Atomen durch Stöße mit gesättigten Kohlenwasserstoffen/Disorientation of Optically Oriented Na-atoms in Collisions with Saturated Hydrocarbons
Authors: Soboll H.
Published: February 2015

Cross sections for collisionally induced disorientation of of the Na (3 2S½) sublevels have been measured for the C1 - C4 saturated hydrocarbons. The strong increase of the cross sections with the number of buffer gas electrons can be explained by using the model of spin-orbit-relaxation.
Notizen: Helixinversion in einem binären Mischsystem nematisch/cholesterisch/Helical Inversion of a Binary System of a Nematic and a Cholesteric Mesophase
Authors: Finkelmann H. , Stegemeyer H.
Published: February 2015

In a binary system of a nematic and a cholesteric liquid crystal an inversion of the helix - sense has been observed at a definite composition xn by measurements of circular dichroism and optical rotatory power. The inversion is accompanied by a decrease of the helical twisting power approaching zero at xn .
The Temperature Dependence of the Viscomagnetic Effect
Authors: Burgmans A. L. J. , Ditzhuyzen P. G. van , Knaap H. F. P. , Beenakker J. J. M.
Published: February 2015

A study is presented of the effect of a magnetic field on the viscosity of HD, N2, CO and CH4 . The temperature dependence of this viscomagnetic effect has been measured in the range between 300 K and the boiling point of these gases. The results are presented in terms of effective cross sections which depend directly on the angle dependent part of the intermolecular potential. The cross sections for reorientation of angular momentum have been compared with those obtained from N.M.R. measurements.
Zur Theorie der NMR-Spektren von symmetrischen Spinsystemen mit I = ½ / On the Theory of NMR-Spectra of Symmetrical Spin Systems with I = ½
Authors: Kleindienst Heinz
Published: February 2015

In this paper a group theoretical method for the determination of the optimal factorization of the Hamiltonian matrix is presented.
Molekulare Schwingungsexzitonen in Fliissigkeiten
Authors: Döge G.
Published: February 2015

The intermolecular coupling of molecular vibrations in molecular crystals is usually treated by the exciton concept. This is identical with the assumption that a potential, which describes the interaction of a vibrating molecule with its neighbours, perturbs the isolated molecule energies and thereby couples the motions of molecules. In most cases this potential will be the transition-dipoletransition- dipole interaction. If one assumes validity of the pair interaction approximation this concept should be able to describe the effects in the liquid state, too. The aim of these considerations is to show, how collective excitation can influence the shape of vibrational bands. Because dipoledipole interaction is strongly orientation dependent, molecular reorientations perturb the coupling of the vibrations and cause motional narrowing. The behaviour of the shapes of the vibration bands of CH3J is discussed on the basis of these considerations. One finds that the band shape of ν2 is mainly broadened by vibration coupling. As expected a distinct motional narrowing is observed, if one increases the temperature from the melting point to the boiling point.
Interactions of CO and O2 with Ir(110)Surfaces
Authors: Christmann K. , Ertl G.
Published: February 2015

LEED/Auger studies with Ir(110) revealed that the clean surface is reconstructed to a 1X2- structure, whereas the normal 1X1-structure can be stabilized by small amounts of carbon impurities. Carbon monoxide adsorbs with a mean heat of adsorption of 37 kcal/mole and forms a 2X1- structure without affecting the substrate "extra" diffraction spots. Adsorbed oxygen forms 2X2- and c2X2-structures, whereby the diffraction features of the 1X2-structure disappear indicating that oxygen atoms cause place exchange process of the Ir surface atoms which is not the case with adsorbed CO. Carbon monoxide tends to dissociate at elevated temperatures. The catalytic oxidation of CO proceeds in a manner similar to that found with Pd and Pt surfaces.
Der Jahn-Teller-Effektdes Cu2+-Ions in tetraedrischer Sauerstoffkoordination
Authors: Reinen D. , Grefer J.
Published: February 2015

The ligand field reflectance spectra of tetrahedrally coordinated Cu2+-ions in different oxidic host structures (several spinel compounds, Ca2ZnSi2O7 , Zn2SiO4 , several garnets, ZnO) and at different temperatures (300 °K - 4 °K) are analysed. For Cu2+-ions in compressed tetrahedra with D2d-symmetry the two expected bands: 2B2(2T2) → 2E (2T2) [t1] and 2A1 (2E) [t3] respectively were found, while in cases of lower symmetry the transition 2B2(2T2) → 2B1(2E) [t2] is observed in addition. For the spinel mixed crystal series [Zn1-xCux] (4) [Cr2] (6)O4 (0≦x ≦ 1,0) a first order transition from the cubic to a tetragonal (c/a < 1) structure occurs at :r = 0.47. The transitions t1 and t3 show a remarkable UV-shift for x>0,47, indicating an increasing Jahn-Teller distortion of the CuO4- tetrahedra with increasing x. The Jahn-Teller-splitting of the 2T2-groundstate [t1] was found to range between ≈ 3000 cm-1 and 8500 cm-1 for the different compounds. The bands could be fitted using "angular overlap" parameters eλ (λ = σ, π⊥, π||). Finally the spectrum of Cu2+-doped ZnO could be analysed on the basis of trigonally compressed CuO4-tetrahedra with a 2T2-groundstate splitting of ≈ 3000 cm-1.
Rotationskonstante und Kernquadrupolkopplungskonstante des Trimethylehlorsilans, bestimmt aus Mikrowellenspektren / Rotational Constant and Nuclear Quadrupole Coupling Constant of Trimethylchlorosilane, Determined by Microwave Spectrum
Authors: Zeil Werner , Haas Bernhard
Published: February 2015

The microwave spectrum of trimethylchlorosilane has been investigated between 8 and 20 GHz. The quadrupole splitting of the K = 0 lines of the transitions J = 2 → 3 and 3 → 4 have been determined. The quadrupole coupling constant of the Cl-35 atom is determined to -34.701 MHz, and the rotational constant is determined to B0 = 2197.382 MHz.
Miscibility Gaps in Fused Salts
Authors: Margheritis Chiara , Flor Giorgio , Sinistri Cesare
Published: February 2015

Twelve systems formed with lithium fluoride and alkali halides were studied in order to put into evidence possible demixing phenomena. Liquiddiquid equilibra were found in the seven mixtures containing KBr, KI, RbBr, Rbl, CsCl, CsBr, and Csl; however, the miscibility gaps could be fully detected only for LiF + CsCl, LiF + KBr and LiF + RbBr.

The tendency to demix in these systems, formed by typically ionic components, agrees with the reciprocal Coulomb effect rule.

On the basis of the solid liquid and liquiddiquid equilibria, the LiF excess potentials were evaluated and compared with those calculated according to current theories.
Lumineszenzspektroskopische Eigenschaften von Circobiphenyl / Luminescence Properties of Circobiphenyl
Authors: Zander M.
Published: February 2015

Fluorescence, phosphorescence and E-type delayed fluorescence of circobiphenyl (II) has been studied. Besides coronene (I) circobiphenyl as yet is the only known polycyclic aromatic hydrocarbon which displays E-type delayed fluorescence.
Non-Lorentzian Shape of the Depolarized Rayleigh Line and the Correlation Function of the Tensor Polarization
Authors: Hess S. , Vestner H.
Published: February 2015

The correlation function of the tensor polarization relevant for the depolarized Rayleigh line of a gas of rotating linear molecules is calculated for the pressure broadening regime. Point of depar­ture is the Waldmann-Snider equation for the distribution function of the gas. Due to the collisional coupling between the tensor polarization and other moments of the distribution function the cor­relation function turns out to be a sum of exponential functions. Consequently the depolarized Rayleigh line has a non-Lorentzian shape.
Solution of the Dirac Equation for Scalar Potentials and its Implications in Atomic Physics
Authors: Soff Gerhard , Müller Berndt , Rafelski Johann , Greiner Walter
Published: February 2015

The Dirac equation is solved for mixed vector-scalar potentials. The limits on the scalar coupling constant are set by precision atomic experiments, We obtain the maximal size of the scalar coupling constant α' = 2.5·10-8 per charge unit. Deviations from the Mott scattering are also determined.
First Order Perturbation Theory in the Study of Molecular Vibrations: Isotopic Rules and Properties of the Different Approximations
Authors: Alix A. , Mohan N. , Midler A. , Rai S. N.
Published: February 2015

The first order perturbation expressions for various molecular constants such as isotopic shifts (⊿λi, ⊿λi/λi), inverse isotopic shifts (⊿σi, ⊿σi/σi), Coriolis coupling constants (Δξij)and mean amplitudes of vibration (Δ∑ij) obtained using different equations and approximations are given in detail.

The mathematical and physical properties of the different approximations are discussed extensively. Incidentally some isotopic rules obtained using the first order perturbation theory are presented.
Coupling to the Lower-hybrid Resonance
Authors: Puri S. , Tutter M.
Published: February 2015

The transmission coefficient of a plane electromagnetic wave into a cold, inhomogeneous, mag­netized, deuterium plasma half-space and its eventual absorption at the lower-hybrid layer is com­puted numerically for a wide range of parameters. It is found that TM (transverse magnetic) waves incident at small angles with the vacuum-plasma interface couple into the plasma provided that ω/ωci ≲ 20. Assuming that coupling to the lower-hybrid resonance in the cold-plasma approxima­tion is an indication of accessibility to the ion-cyclotron-harmonic waves in the hotplasma case, an alternative statement of the results obtained is that efficient coupling is possible from the second till the twentieth harmonic of the ion gyrofrequency using an antenna that launches TM waves at an approximately grazing incidence on the plasma surface. Simple configurations for coupling rf energy into thermonuclear plasma are suggested.
Permittivität TiO2-rcicher Bariumtitanatkeramik / Permittivity of TiO2-enriched barium titanate ceramics
Authors: Hoffmann B. , Lauer R.
Published: February 2015

In nonstoichiometric barium titanate ceramics an excess of TiO2 leads to the formation of a second phase completely covering the individual grains. For that reason even a small amount of the second phase causes a strong decrease of the permittivity of the ceramic material.
Quantum States with Maximum Information Entropy. II
Authors: Ochs W. , Bayer W.
Published: February 2015

We examine the conditions which a given information of the form “Tr(W Ar) = mr;r = 1,...,h” must satisfy in order to determine a unique quantum state with maximum information entropy. Special consideration is given to the case of commuting Ar which is most important for statistical thermodynamics.
Compressible Jeffery-Hamel Flow of a Plasma
Authors: Wilhelm H. E.
Published: February 2015

A similarity transformation is given, which reduces the partial, nonlinear differential equations describing a compressible, polytropic plasma flow across an azimuthal magnetic field in a duct with plane inclined walls to an ordinary nonlinear differential equation of second order. The latter is solved rigorously in terms of a hyperelliptic integral. The form of the plasma flow fields in pure outflows (diffuser) is discussed analytically in dependence of the Reynolds (R) and Hartmann (H) numbers and the polytropic coefficient (γ) for given duct angles θ0 . The realizable Mach numbers are shown to be eigenvalues of the nonlinear boundary-value problem, M=MX{R, H, γ, θ0). The flow solutions are different in type for Hartmann numbers H 1) below and 2) above a critical Hartmann number Hc defined by Hc
2= [2(γ - 1)/(γ +1)]R+ [2 γ/(γ +1)]2. Some of the eigenvalues Mx are calculated and the associated velocity profiles are represented graphically for prescribed flow parameters.
LX-ray Spectra and E2 Internal Conversion Coefficients in Radon and Radium
Authors: Pinho A. G. de , Weksler M.
Published: February 2015

The X-ray spectra resulting from the internal conversion of electric quadrupole transitions following the alpha decay of Th230 and Ra226 were analysed with a Si (Li) spectrometer. From the knowledge of the Coster-Kronig and fluorescence yields, the internal conversion coefficients of the E2 transitions from the first excited states in Ra226 and Rn222 could be deduced. Results are in good agreement with theoretical values.
Stueckelberg-Landau-Zener-(SLZ)-Modell für atomare Stoßprozesse / Stueckelberg-Landau-Zener-(SLZ) Model for Atomic Scattering Processes
Authors: Raabe G.-P.
Published: February 2015

Scattering processes of atoms, molecules and ions with two crossing electronic potentials may be treated in the Stueckelberg-Landau-Zener-(SLZ) model. In this paper the WKB-solutions for the radial wave functions, given by Stueckelberg are used to calculate differential cross sections. The effects on the cross sections are explained in a semiclassical picture, following the procedures of Ford and Wheeler, and Berry. In the scattering of H+ by rare gases, some effects in the elastic cross sections are observed which can be explained by the influence of the potential of the chargeexchanged particles, using the SLZ-model. The structure in the elastic cross sections for H2
+-Kr can be explained as a rainbow structure with superimposed Stueckelberg oscillations.
Berechnung von Ladungsverteilungen in Elektronenstrahl-Plasma-Hochladungsionenquellen / Calculation of charge state densities in electron beam multiply charged ion sources
Authors: Hertenberger G. , Roch K. , Winter H.
Published: February 2015

Regarding both step by step and direct ionization by electron impact, and including losses from radiative recombination and charge exchange, a simple model for calculation of charge state densities in electron beam multiply charged ion sources has been developed. The diffusion of the created charged particles out of the ionization volume is included in the model. A monoenergetic electron beam of high current density interacts with a gas at a pressure range from 10-6 to 10-4 Torr. The calculations were performed for Argon, Krypton and Xenon with an impact energy from 2 keV to 10 keV. Influences of several elementary processes were discussed in regard to developments of new types of multiply charged ion sources.
Strahlungslose Übertragung der Anregungsenergie in lumineszierenden Lösungen verschiedener Konzentrationsverhältnisse von Donor zu Akzeptor / Non-Radiative Excitation Energy Transfer in Luminescent Solutions at Different Ratios of Donor to Acceptor Concentration
Authors: Bojarski C. , Burak F. , Grabowska E.
Published: February 2015

Photoluminescence (PL) quantum yields (η/η0) of Na-fluoresceine (donor) in dependence on phloxin (acceptor) concentration in glycerin-water solutions at ratios of donor to acceptor concentration CD/CA equal to 48.2, 14.5 and 2.4 have been measured.

Similar measurements have been made on acriflavine (donor) and rhodamine B (acceptor) in methanol for CD/CA = 10 and 0.4. In all systems investigated it was found that the PL-yield η/η0 of the donor at a fixed value of CA is the smaller the bigger is the value of CD/CA. The experimental results have been compared with a theory (Z. Naturforsch. 25 a, 1760 [1970], Acta Phys. Hung. 30, 145 [1971]) describing concentrational changes of the PL-quantum yield. Full agreement of theory with experiment is found and the possibility of multi-step non-radiative excitation energy transfer from donor to acceptor has been proved.
Nuclear (14N, H) Spin Relaxation of 3,5-Dichloropyridine in Solution
Authors: Žaucer M. , Perko J. , Jagodic F. , Ažman A.
Published: February 2015

14N and H spin-lattice relaxations have been measured. Various contributions to the protons spin-lattice relaxations are determined. The spin-rotation and the scalar relaxation, through quadrupole relaxation of N. contribute considerably.
MHD-Instabilitäten im Verdampfungsstadium elektrisch stoßaufgeheizter Drähte
Authors: Jäger H. , Siebke H. J.
Published: February 2015

The well known striation effect observable during the evaporation process of exploding wires is of MHD-origin even in cases of very fine striation structures. This has been proved by application of an axial magnetic field which has a considerable influence on the effect.
Verdampfungsgleichgewicht und thermodynamisehe Funktionen des flüssigen Systems Wasser + Essigsäure / Vapour-Liquid. Equilibrium and Thermodynamic Functions of the Liquid System Water + Acetic Acid
Authors: Haase R. , Pehlke M. , Dücker K.-H.
Published: February 2015

Vapour pressures and vapour compositions of the liquid system water + acetic acid have been measured at 25 °C, 30 °C, 35 °C, 40 °C, and 45 °C in the whole range of compositions. The dimerization of acetic acid in the vapour being taken into account, the molar excess Gibbs function ḠE is derived from the measurements. Earlier measurements of the molar excess enthalpy HE are combined with the -GE values to give the molar excess entropy SE. The “symmetry rule” (Haase, 1951) concerning the composition dependence of ḠE, -HE, and S̄E has been confirmed.
Über der Kopplung von Schwingungsfreiheitsgraden an die Koordinate intramolekularer Umlagerungen / Coupling of Vibrational Degrees of Freedom lo the Coordinate of Intramolecular Rearrangements
Authors: Brickmann J.
Published: February 2015

Intramolecular rearrangements A ⇌ B are investigated, which can be described in terms of the motion of an effective quantum mechanical ‘‘particle’’ on an energy surface with at least two minima. We regard the energy surface as a function of a limited number of relevant internal degrees of freedom. The rate of isomerization is calculated from the matrix elements of a transition operator W with respect to the localized quantum states of the two isomers, and the coupling to the inter- and intramolecular degrees of freedom, not explizitely considered in the energy surface. It is shown that the matrixelements of W be reduced to integrals over functions of the adiabatic reaction coordinate of the isomerization, and selection rules for the vibrational quantum numbers for the motion perpendicular to this coordinate. The degrees of freedom not relevant for the reaction are summarily taken into account by introducing a heath bath in thermodynamic equilibrium and a simple damping term. Applications are discussed.
A New Approach to Thermodynamics of Simple Mixtures
Authors: Müller Ingo
Published: February 2015

A general entropy principle is utilized to derive restrictions on the constitutive relations for simple mixtures. The absolute temperature and chemical potentials are introduced in a novel manner and the equality of the coefficients of thermal diffusion and of the diffusion-thermo coefficients is proved for a subclass of simple mixtures by use of macroscopic arguments.
Phenomenological Theory of the Ferroelectric Dispersion and Microwave Investigations of Colemanite
Authors: Brosowski G. , Luther G. , Petersson J.
Published: February 2015

The ferroelectric dispersion of the dielectric constant of colemanite is investigated by a coaxial equipment between -15 °C and +15 °C. In the entire temperature range the dispersion is of the mono-dispersive Debyc type. In a first approximation both the relaxation time τε and the static dielectric constant can be represented by a Curie-Weiß law. The relaxation time of the non-inter- action dipole system shows a characteristic temperature dependence. The phenomenological theory assumes a non-linear coupling between certain quantities of state, and thus it constitutes a generalization of a known linear thermodynamic theory of relaxation phenomena. By this theory various material quantities which are temperature dependent are related to each other. The theory may be applied to all those ferroelectric crystals with a phase transition of the second order which are not piezoelectric in the paraelectric phase. The experimental results obtained for colemanite agree with the predictions of the theory.
Berechnung der Spin-Spin-Koppelkonstante von HD mit nichtsingulärem Kontaktoperator / Calculation of the NMR Coupling Constant in HD by Using a Nonsingitlar Contact Operator
Authors: Sänger W. , Voitländer J.
Published: February 2015

The Fermi contact contribution to the nuclear spin-spin coupling constant of HD is calculated variationally. Instead of the delta-function a modified nonsingular contact spatial part is used. The self-coupling energy becomes finite and the variation of the whole second-order energy due to a non- singular first-order perturbed trial function can be carried out.