Intermolecular hydrogen bonding in isostructural pincer complexes [OH-(t-BuPOCOPt-Bu)MCl] (M = Pd and Pt)

In the crystal structure of the isostructural title compounds, namely {2,6-bis[(di-tert-butylphosphanyl)oxy]-4-hydroxyphenyl}chloridopalladium(II), [Pd(C22H39O3P2)Cl], 1, and {2,6-bis[(di-tert-butylphosphanyl)oxy]-4-hydroxyphenyl}chloridoplatinum(II), [Pt(C22H39O3P2)Cl], 2, the metal centres are coordinated in a distorted square-planar fashion by the POCOP pincer fragment and the chloride ligand. Both complexes form strong hydrogen-bonded chain structures through an interaction of the OH group in the 4-position of the aromatic POCOP backbone with the halide ligand

Are we there yet? Australian road safety targets and road traffic crash fatalities

Background: Road safety targets are widely used and provide a basis for evaluating progress in road safety outcomes against a quantified goal. In Australia, a reduction in fatalities from road traffic crashes (RTCs) is a public policy objective: a national target of no more than 5.6 fatalities per 100,000 population by 2010 was set in 2001. The purpose of this paper is to examine the progress Australia and its states and territories have made in reducing RTC fatalities, and to estimate when the 2010 target may be reached by the jurisdictions. Methods. Following a descriptive analysis, univariate time-series models estimate past trends in fatality rates over recent decades. Data for differing time periods are analysed and different trend specifications estimated. Preferred models were selected on the basis of statistical criteria and the period covered by the data. The results of preferred regressions are used to determine out-of-sample forecasts of when the national target may be attained by the jurisdictions. Though there are limitations with the time series approach used, inadequate data precluded the estimation of a full causal/structural model. Results: Statistically significant reductions in fatality rates since 1971 were found for all jurisdictions with the national rate decreasing on average, 3% per year since 1992. However the gains have varied across time and space, with percent changes in fatality rates ranging from an 8% increase in New South Wales 1972-1981 to a 46% decrease in Queensland 1982-1991. Based on an estimate of past trends, it is possible that the target set for 2010 may not be reached nationally, until 2016. Unsurprisingly, the analysis indicated a range of outcomes for the respective state/territory jurisdictions though these results should be interpreted with caution due to different assumptions and length of data. Conclusions: Results indicate that while Australia has been successful over recent decades in reducing RTC mortality, an important gap between aspirations and achievements remains. Moreover, unless there are fairly radical ("trend-breaking") changes in the factors that affect the incidence of RTC fatalities, deaths from RTCs are likely to remain above the national target in some areas of Australia, for years to come

A Comparative Study on the Thermodynamics of Halogen Bonding of Group 10 Pincer Fluoride Complexes

The thermodynamics of halogen bonding of a series of isostructural Group 10 metal pincer fluoride complexes of the type [(3,5-R2-tBuPOCOPtBu)MF] (3,5-R2-tBuPOCOPtBu=κ3-C6HR2-2,6-(OPtBu2)2 with R=H, tBu, COOMe; M=Ni, Pd, Pt) and iodopentafluorobenzene was investigated. Based on NMR experiments at different temperatures, all complexes 1-tBu (R=tBu, M=Ni), 2-H (R=H, M=Pd), 2-tBu (R=tBu, M=Pd), 2-COOMe (R=COOMe, M=Pd) and 3-tBu (R=tBu, M=Pt) form strong halogen bonds with Pd complexes showing significantly stronger binding to iodopentafluorobenzene. Structural and computational analysis of a model adduct of complex 2-tBu with 1,4-diiodotetrafluorobenzene as well as of structures of iodopentafluorobenzene in toluene solution shows that formation of a type I contact occurs

X‐ray reflection properties of annealed silicon single crystals

We present a series of x‐ray reflectivity measurements performed on annealed Czochralski grown silicon (ACS) crystals in the energy range E<50 keV using sealed tube sources. To analyze the origin of the enhanced reflectivity of this material compared to perfect, FZ‐grown silicon, double and triple crystal diffractometer measurements were carried out. The results are discussed with regard to the application of ACS for monochromatization of synchrotron radiation in the mentioned energy range

Multilayer optics for intense synchrotron x‐ray beams: Recent results on their performance

Present‐day synchrotron x‐ray beams are very demanding in terms of thermal, mechanical, and radiation stability of any optical element to be inserted in the beam. A set of multilayers was recently exposed and could resist to an x‐ray power density in excess of 7.5 W/mm2, which is comparable to the one expected for the multilayers to be used at ESRF. Such a power density was obtained by setting the multilayers at a grazing angle of about 2° in a focused wiggler beam of 4.6 keV critical energy. The specimen, W/B4C and W/Si multilayers, were cooled either at room temperature or down to liquid nitrogen temperature during an 8–16 h exposure time

Der Zubau von Kraft-Waerme-Kopplungsausruestungen in bestehende Heizwerke der neuen Bundeslaender

While in condensing power plants an efficiency of about 40% can be attained for power generation this can be increased to 85% with combined heat and power generation in cogeneration plants. The primary aim is to find suitable technological solutions for existing heating stations with 6.5 t/h, 10 t/h and 40 t/h steam generators (pressure 1.3 MPa, superheater outlet temperature 220 C) in order to realize primary energy savings, an additional effective possibility to generate electric energy as well as a reduction of environmental loads and finally a competitive plant by retrofitting the plant with cogeneration units (steam turbines, gas turbines, combustion engines). The study aims at comparing the additional expenses on the one hand and the improvements, particularly the reduction of energy consumption and environmental loads, on the other. In order to solve this task for a number of varied conditions (fuel, steam parameters, circuit parameters) the resulting total costs from construction and operation of the heat-generating plant were determined for one heat unit and compared to each other. (orig.)Waehrend bei einer Stromerzeugung in einem Kondensationskraftwerk ein Wirkungsgrad von etwa 40% erreicht wird, laesst sich dieser bei gemeinsamer Erzeugung von Strom und Waerme in einem Heizkraftwerk auf bis zu 85% steigern. Primaer gilt es, fuer die bestehenden Heizwerke mit 6,5 t/h, 10 t/h und 40 t/h-Dampferzeugern (Druckstufe 1,3 MPa, 220 C Ueberhitzer-Austrittstemperatur) geeignete technologische Loesungen zu erarbeiten, um durch Zubau von KWK-Anlagen (Dampfturbinen, Gasturbinen, Verbrennungsmotoren) eine Einsparung von Primaerenergie, eine zusaetzliche effektive Elektroenergieerzeugung sowie einen guenstigen Beitrag zur Umweltentlastung und letztlich eine wettbewerbsfaehige Anlage zu erreichen. (orig.)Available from TIB Hannover: D.Dt.F. AC 1000(45,46) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman