Compression of α-MnS (alabandite) and a new high-pressure phase

The compressibility of -Mns (alabandite) was determined by x-ray analysis using a Mao-Bell type diamond anvil cell. The zero pressure bulk modulus (K₀) is 74±2 GPa with the pressure derivative of the bulk modulus (K_o) fixed at four. Allowing (K_o) to vary yielded a statistically better fit with K₀ = 88±6 GPa and k₀ = 2.2±0.6. Our data combined with the data of McCammon (1991) gave K_o = 73±1 GPa with k_o fixed at four. A fit with k_o allowed to vary yielded k_o = 75±2 GPa and k_o = 3.7±0.4. Alabandite transformed from the B1 structure (NaCl-type) to an unknown high-pressure phase at 26 GPa. The high-pressure phase has lower than hexagonal symmetry and it is stable to at least 46±4 GPa.Also affiliated with the James Franck Institute, University of Chicago     

On the wavelength dependency of solar limb darkening (λλ303 to 1099 nm)

The limb-darkening data published by Neckel and Labs (1994) (5th-order polynomials P ₅(), = cos ) are used to represent the limb darkening by the functions L _n(), proposed first by Kourganoff (1949a). When plotted against wavelength, the coefficients of these functions show a rather low scatter and appear to be linear functions of either ^–1 or ^#x2212;5.     

Improved data of solar spectral irradiance from 0.33 to 1.25μ

The conversion of our centre of disk intensities published in 1968/70 into mean disk intensities has been repeated, using more accurate data for the centre-to-limb variation of both continuous radiation and strong absorption lines.The random observational mean error of the new irradiance data very likely is not larger than 1.5% in the UV and not larger than 1% in the visible and infrared. Comparison with the fluxes of Sun-like stars observed by Hardorp (1980) confirms these errors and seems to exclude the possibility of a systematic, wavelength-dependent scale error which would correspond to a temperature difference larger than 50 K.The resulting integral value of the irradiance between 0.33 and 1.25 is 1.060, the corresponding value of the solar constant lies between 1.368 and 1.377 kWm^-2.Proceedings of the 14th ESLAB Symposium on Physics of Solar Variations, 16–19 September 1980, Scheveningen, The Netherlands.     

Variations of ‘wavelengths’ and ‘bisector indices’ of 70 solar spectral lines between 3300 and 3960 Å in Kitt Peak FTS spectra

Wavelengths and bisector indices (a special measure for the asymmetry of a line near its bottom) are determined for 70 lines in each of 47 high-dispersion spectra. The spectra were obtained with the Fourier Transform Spectrograph connected to the McMath Telescope at Kitt Peak National Observatory; they all cover the same spectral range from 3200 to 4000 Å and concern either the full disk (19 disk spectra), or the disk center (9 center spectra), or two areas at sin = 0.85 on the west- and east-side of the disk (19 limb spectra). The main observing seasons were June 1986, June 1987, April and June/July 1988. The - relative - position of an individual line in one spectrum can be established with a precision of about 4 m s^-1, the precision of one bisector index is 1–2 m s^-1.Wavelengths and bisector indices show of course the typical characteristics which result from the familiar effects known as blueshift, limb effect and line asymmetry. However, concerning their variations in time, unexpected results are obtained:(1) Even in disk spectra the time-scales of the wavelength variations are often in the order of one hour or less. (2) For all 3 types of spectra (disk, center, limb) the variations depend not only on the known parameters such as line depth and - occasionally - excitation potential, but also - often even primarily - on wavelength. (3) In center spectra, the wavelength differences between strong and faint lines can vary by as much as 500 m s^-1, in disk spectra short-time variations of wavelength differences can amount to more than 50 m s^-1. (4) For most spectra there is not only a very pronounced and narrow correlation between line shift and line temperature (a special measure for the line depth), but also a significant correlation between line shift and variation of the bisector index.Clearly, the observed effects must be attributed to variations of the velocity fields in the upper photosphere/lower chromosphere (super-granulation cells, overshooting, oscillations), which either influence the line wavelengths directly via the Doppler-effect, or indirectly by changing the contrast between the blue-shifted granules and the red-shifted intergranular lanes. Because of the snapshot character of the observations, no reliable conclusions can be drawn on the actual time-dependency.     

The role of telescopic stray light in limb-darkening scans obtained in April 1981 (and later)

The suspicion of Elste (1990), that telescopic stray light together with imperfect collimation of telescope and spectrograph could be a possible explanation for the systematic differences and variations found by Neckel and Labs (1987) in many limb-darkening scans, proves to be unfounded for the following reasons: (1)The collimation was performed very precisely; (2) the telescope mirrors remained fixed in position and direction during most of the observing period; (3) stray light effects depending on hour angle were not detectable; (4) in the same collimation status, also many almost symmetric scans had been recorded; (5) the observed east-west differences in the solar intensities are partly even larger than the total amount of stray light (from telescope and sky!) observed as sky-background just outside the limb; (6) any east-west differences in the sky-background near the limb are just a few 0.01% of the disk center intensity; (7) the differences of the average intensities along eastern and western radius appear to be correlated with the east-west differences of the intensity's R.M.S.     

Halogenation processes linked to red wood ant nests (<Emphasis Type="Italic">Formica</Emphasis> spp.) and tectonics

We investigated and evaluated the occurrence of fault zone tracer gases (CO₂, He, Rn), volatile organohalogens (CH₃Cl, CHCl₃, CHBr₃), alkanes and limonene in soil and nest gases of red wood ants (RWA) in comparison to ambient air, in a seismically active area. In this new approach, we compared RWA-free areas to RWA-areas by combining different investigation and analytical methods. In soil gas, the fault zone tracer gas Rn was surprisingly highly correlated to limonene, suggesting a combination of biotic production of limonene and abiotic degassing of Rn in a seismically active area; moderate correlations were found with trihalomethanes and other halocarbons. In RWA nests a variety of elevated concentrations of haloforms were found, while remaining below the atmospheric background values in RWA-free areas. The evidence of CHCl₃ in RWA nests is the first record. Its average concentrations in nests of F. rufa and F. polyctena were up to 3 fold higher than atmospheric background and up to 28–70 fold higher compared to e.g. volcanic emissions being considered as one of its main geogenic sources. Thus, RWA nests could possibly be an additional source for CHCl₃ liberation. Consequently, apart from RWA being bioindicators for seismically active degassing faults, they might also be used as bioindicators for CHCl₃ formation in forest soils. Although we cannot yet differentiate between a geogenic/abiotic and a biotic formation. RWA nests will have to be reconsidered for halocarbon formation in future quantifications of geochemical cycles at global scale, since they impact organic soil chemistry through biotic and/or abiotic pathways. Therefore, further larger-scale research in different tectonic settings but also in well-known CHCl₃ “hot spot” study areas such as the Klosterhede area (Denmark) should focus directly on gas sampling from confirmed active fault systems. Nests of other ant species should be addressed to compare seasonal, diurnal and nocturnal variations of degassing procedures in relation to earth tides, different geologic settings, and tectonic events such as earthquakes and on quantifying the fluxes to the atmosphere.     

Neue Mineralvorkommen aus den Ostalpen

Zusammenfassung Bei den hier beschriebenen Mineralfunden handelt es sich teils um Neubearbeitungen alter Stücke aus Museums- oder Privatsammlungen, teils um neue Aufsammlungen.Cölestin von Kreuth bei Bleiberg.Slavikit undFibroferrit bei Rennweg.Pyrargyrit von Ruden bei Völkermarkt. Ein auffallend schönerZinnoberkristall vom steir. Erzberg.- und-Schwefel aus dem Köflach-Voitsberger Braunkohlengebiet. NetteRealgarkristalle vom Mischlinggraben im Lavanttal.Lansfordit undNesquehonit aus dem Serpentingebiet von Kraubat.Valentinit- undArsenolitkristalle, Symplesit undFerrisymplesit vom Hüttenberger Erzberg (Österreichs mineralartenreichster Lagerstätte). Insgesamt eine kleine Auswahl mineralogischer Neuentdeckungen (1947/49) aus dem Ostalpenraum, die zeigen, daß die mineralogische Durchforschung auch hier noch lange nicht abgeschlossen ist. Weitere Mitteilungen sollen folgen.     

Zur Qualität des Peilminimums beim Funkpeilen

Zusammenfassung Es wird gezeigt, wie neben dem für die Praxis wichtigen subjektiven Peilbefund durch vergleichende Messungen ein objektiver Befund mit quantitativem Gewicht erhalten werden kann. Die sich daraus ergebenden Folgerungen werden diskutiert.

---

On the quality of the minimum intensity in radio-goniometry

Summary In the following paper it is pointed out how it is possible to obtain, in addition to the usual subjective results which are important in practice, objective results of quantitative weight by means of comparative measurements. The consequences resulting therefrom are discussed.

---

Quelques remarques sur la qualité du minimum d'intensité en radiogoniométrie

Résumé On montre dans ce traité comment il est possible d'obtenir, outre les résultats usuels subjectifs qui sont d'importance dans la pratique, des résultats objectifs à poids quantitatif par des mesures comparatives, Les conséquences en résultant sont discutées.

     

Zur Biologie vonSphaerotilus natans Kützing

Zusammenfassung Unter Zuhilfenahme eines festen N?hrbodens gelang die Reinkultur vonCladothrix dichotoma. Eine überführung vonCladothrix in die alsSphaerotilus natans bekannte Form gelang bei Kultivierung in einem flüssigen N?hrsubstrat nach Zusatz von Asparagin und bei h?ufiger Erneuerung des N?hrsubstrates. Dabei war es gleichgültig, ob als Ausgangsmaterial die natürliche Standortsform vonCladothrix oder die vonSphaerotilus gew?hlt wurde. Auf festen N?hrb?den stellte sich stets typischesCladothrixwachstum ein. Ebenso l?sst sich eine auf obige Weise erhalteneSphaerotilusausbildung bei Drosselung des N?hrstoffangebotes in eineCladothrixausbildung zurückführen. Die Frage nach der Verwandtschaft vonCladothrix undSphaerotilus kann danach dahingehend beantwortet werden, dassSphaerotilus natans als ?üppigkeitsform? vonCladothrix dichotoma aufzufassen sein dürfte. Beobachtungen anderer Autoren (zum BeispielKolkwitz, 1926, undPringsheim, 1951, 1952), würden damit eine Best?tigung erfahren. Durch die Annahme, dassSphaerotilus natans eine physiologisch bedingte Form vonCladothrix dichotoma darstellt, w?re zugleich eine Erkl?rung für die schlagartige Ausbreitung desSphaerotilus natans in Vorflutern mit Zuckerfabrikabw?ssern gegeben. Eine Zusammenstellung aller uns erreichbaren Literatur überSphaerotilus undCladothrix wird angefügt.     

An overview of the city of Gweru,Zimbabwe’s water supply chain capacity: towards a demand-oriented approach in domestic water service delivery

Following complaints about water shortages in some areas of Gweru, the paper assessed the availability of enabling capacities to efficiently and sufficiently deliver water to the residents of Gweru in line with the existing level of demand. The key inspected capacity aspects were infrastructure, human resources, finances and physical availability of raw water at source. Purposively selected informants from Zimbabwe National Water Authority (ZINWA) and Gweru city council (GCC) provided data on the infrastructural, financial and human resources situation of GCC. Dam levels data for Gweru’s three supply dams were obtained from ZINWA records through the assistance of Sanyati Catchment Hydrologist. The raw water availability was assessed with the aid of Mann–Kendall test using a 10 years period data set from 2003 to 2012 for trend analysis. Findings revealed that the water sources were not experiencing major changes in water levels, to be precise, the changes were insignificant. However, given the increase in population and demand, any slightest negative change in the supply chain would further widen the gap between supply and demand. The study also uncovered that GCC had challenges in terms of the infrastructure, mainly due to financial constraints. Notably, GCC was not experiencing high staff turnover, but it was however, seriously under staffed and failing to effectively monitor water use in the city. Therefore, strong financial injection is required to support staff and resuscitate the reticulation system. Given the perpetual water shortages in Gweru and the status quo in the supply chain, water demand management strategies, wastewater use and consumer education are consequently proposed as measures that would ensure continuous water supply for all needs in the city.