Single photon initiated decomposition rearrangement reactions (SPIDRR) of organic molecules mediated by the Ni+ cation

The Bellert group at Baylor University has developed a novel method for performing single photon initiated decomposition rearrangement reactions (SPIDRR) of organic molecules mediated by a transition metal cation. The advantage that SPIDRR affords is the direct measurement of first order microcanonical rate constants, k(E), determined at resolved internal energies. Furthermore, the SPIDRR technique measures kinetic details of exothermic reactions where product production is limited only by submerged activation barriers (kinetic barriers that are at energies below the separated reactant limit). Thus, such reactions approach unit efficiency, are thermodynamically driven, and are of greater relevance to catalytic research. Direct measurements of k(E) values extend to isotopically labelled species that provide direct measurement of the kinetic isotope effect (KIE), furnishing unique insight into the mechanistic details of a reaction. This talk presents results from the visible photon initiated, Ni$^{+}$ induced decarbonylation reaction of propionaldehyde. Here a rather unique energy dependent behavior of the measured rate constants was observed and attributed to a dynamic competition between parallel reaction coordinates available to the photo-excited precursor. RRKM calculations in concert with high level DFT is used to support and further experimental results

Das OvSynch-Verfahren zur Behandlung von Kühen mit Azyklie oder Ovarialzysten

In this study the effects of the OvSynch procedure on ovarian function and fertility of acyclic cows and those with ovarian cysts were investigated and compared with cycling cows in an OvSynch programme. This field trial was conducted on 50 farms in a practice district in Upper Bavaria between November 2002 and November 2003 and included a total of 199 dairy cows. Cows were examined by rectal palpation and ultrasound before the OvSynch programme was initiated. In cases where ovarian cysts were detected (one or more follicles >2.5 cm), the OvSynch programme was started immediately (n = 89; Group III). If no ovarian cysts were present, a milk sample (Day -10) was collected for the determination of the progesterone concentration (enzyme-immuno-assay in skimmed milk) and the OvSynch programme was started 10 days later. All cows were treated with GnRH (Day 0), PGF2α (Day 7) and GnRH (Day 9) and inseminated 15-20 hours after the second injection of GnRH. Milk samples were collected from all cows on Day 0 and 7, on the day of artificial insemination and 10 days later. Cows without ovarian cysts were classified in two groups retrospectively according to the progesterone concentration on Day -10 and Day 0: Cows with low progesterone (< 0.5 ng/ml) on both occasions were considered to be acyclic (n = 39; Group II); all other cows were assumed to be cycling (n= 71; Group I). The percentage of cows with a high progesterone value at the first injection of GnRH was 73.2%, 0% and 13.5% in Groups I, II and III respectively. The percentage of cows with a high progesterone value was 45.1%, 36.8% and 57.3% on Day 7 and 84.5%, 92.3% and 82.9% 10 days after artificial insemination in Groups I, II and III respectively. The synchronization rate was 80.3%, 84.2% and 80.7% (Groups I, II and III). The conception rate during the OvSynch programme was 47.9% in cycling cows (Group I), 71.8% in acyclic cows (Group II), and 31.5% in cows with ovarian cysts (Group III). Judged by the progesterone levels, the results of this study show that it was possible to induce luteal function in a high number of acyclic cows. The results also suggest that this treatment can be applied successfully in cycling and acyclic cows when no ovarian cysts are present.Ziel dieser Arbeit war es, die Auswirkungen des OvSynch-Verfahrens auf die Ovarfunktion und die Fruchtbarkeit bei Kuehen mit Azyklie oder Ovarialzysten zu testen und diese mit denen zyklischer Kuehe in einem OvSynch-Programm zu vergleichen. Dazu wurden im Rahmen einer Feldstudie zwischen November 2002 und November 2003 in 50 landwirtschaftlichen Betrieben eines Praxisgebiets in Oberbayern 199 Milchkuehe mit dem OvSynch-Verfahren in ihrer Brunst synchronisiert. Vor Beginn des Ovsynch-Programms wurden alle Kuehe manuell rektal und ultrasonographisch untersucht. Wenn Ovarialzysten (ein oder mehrere Follikel > 2,5 cm) diagnostiziert wurden, wurde das OvSynch-Programm sofort gestartet (n=89; Gruppe III). Wenn keine Ovarialzysten vorhanden waren, wurde zur spaeteren Progesteronbestimmung (kompetitiver Enzymimmuntest aus Magermilch) eine Milchprobe (Tag -10) genommen und das OvSynch-Programm 10 Tage spaeter gestartet. Alle Tiere wurden mit GnRH (Tag 0), PGF2α (Tag 7) und GnRH (Tag 9) behandelt und 15-20 Stunden nach der zweiten GnRH-Applikation besamt. Milchproben wurden waehrend des OvSynch-Programms von allen Tieren am Tag 0 und 7, am Tag der kuenstlichen Besamung und 10 Tage danach genommen. Kuehe ohne Ovarialzysten wurden retrospektiv anhand der Progesteronkonzentrationen am Tag -10 und Tag 0 in zwei Gruppen eingeteilt: Kuehe mit niedrigem Progesteronwert (<0,5ng/ml) an beiden Tagen wurden als azyklisch eingestuft (n=39; Gruppe II), waehrend bei allen anderen Kuehen von einer Zyklizitaet ausgegangen wurde (n=71; Gruppe I). Der Prozentsatz der Tiere mit einem hohen Progesteronwert zum Zeitpunkt der ersten GnRH-Applikation betrug 73,2%, 0% und 13,5% in den Gruppen I, II und III. Der Anteil der Kuehe mit einem hohen Progesteronwert am Tag 7 lag bei 45,1%, 36,8% und 57,3% und am Tag 10 nach der kuenstlichen Besamung bei 84,5%, 92,3% und 82,9% in den Gruppen I, II und III. Damit wurden Synchronisationsraten von 80,3%, 84,2% und 80,7% fuer die Gruppen I, II und III erreicht. Der Erstbesamungserfolg nach dem OvSynch-Programm betrug 47,9% in Gruppe I (zyklische Tiere), 71,8% in Gruppe II (azyklische Tiere) und 31,5% in Gruppe III (Tiere mit Ovarialzysten). Basierend auf den Progesteronkonzentrationen zeigen die Ergebnisse, dass eine Gelbkoerperfunktion bei einer hohen Anzahl azyklischer Kuehe induziert werden konnte. Weiterhin deuten die Ergebnisse darauf hin, dass das OvSynch-Programm erfolgreich bei zyklischen und azyklischen Kuehen eingesetzt werden kann, wenn Ovarialzysten auszuschliessen sind

Spectroscopic characterization of the Zn(4s(2))center dot Ne[(1)Sigma(+)] and Zn(4s4p pi)center dot Ne[(1)Pi(1)] van der Waals states

The Zn(4s2)·Ne[1Σ+] and the Zn(4s4pπ)·Ne[1Π1] states have been characterized by laser-induced fluorescence spectroscopy. Bond lengths were determined from simulations of the partially-resolved rotational structure of the 1Π ← 1Σ+ transitions, while bond strengths were estimated from a Birge–Sponer extrapolation with allowance for consistent errors resulting from similar procedures in the analogous Cd·Ne and Hg·Ne transitions. The van der Waals bonding in these states is discussed briefly and compared to that in the analogous M·RG states, where M=Mg, Zn, Cd, Hg and RG=Ne, Ar, Kr, Xe

Laser Spectroscopic Studies of the E 1£+ State of the MgO Molecule

The E1Σ+ ‘Rydberg' state of 24Mg16O has been characterized by two-color resonance-enhanced two-photon ionization (R2PI) spectroscopy in the 36 000–40 000 cm−1 region. Several rotationally resolved bands, assigned consistently to 24Mg16O(E1Σ+←X1Σ+) vibronic transitions, have been analyzed. The effective Bv′(v′=0−8) constants determined exhibit an unusual variation with v′. Possible causes of this variation are discussed. Estimated spectroscopic constants for the E1Σ+ state are reported

Spectroscopic characterization of the Zn(4s(2))center dot Ne[(1)Sigma(+)] and Zn(4s4p pi)center dot Ne[(1)Pi(1)] van der Waals states

The Zn(4s2)·Ne[1Σ+] and the Zn(4s4pπ)·Ne[1Π1] states have been characterized by laser-induced fluorescence spectroscopy. Bond lengths were determined from simulations of the partially-resolved rotational structure of the 1Π ← 1Σ+ transitions, while bond strengths were estimated from a Birge–Sponer extrapolation with allowance for consistent errors resulting from similar procedures in the analogous Cd·Ne and Hg·Ne transitions. The van der Waals bonding in these states is discussed briefly and compared to that in the analogous M·RG states, where M=Mg, Zn, Cd, Hg and RG=Ne, Ar, Kr, Xe

Simulating Future Urban Expansion in Monastir, Tunisia, as an Input for the Development of Future Risk Scenarios

Under scenarios of urbanization coupled with increasing frequency and intensity of natural hazards, urban disaster risk is set to rise. Simulating future urban expansion can provide relevant information for the development of future exposure scenarios and the identification of targeted risk reduction and adaptation strategies. Here, we present an urban growth simulation for the coastal city of Monastir, Tunisia. The approach integrates local knowledge and a data-driven urban growth model to simulate urban sprawl up to 2030. A business-as-usual projection is used to predict the future growth of the city based on the historical trend. Thirteen Landsat images for the period 1975 to 2017 were used to delineate past changes in urban land cover following the European Urban Atlas standard, which served as the main input for the urban growth model. The simulation revealed that the city’s residential area is likely to grow by 127 ha to an overall size of 1,690 ha by 2030, corresponding to an increase of 8.1% compared to the urban footprint of 2017. The outcomes of the analysis presented here served as an input for the spatial simulation of future exposure to flash floods in the case study area

Theoretical study of M+ RG2: (M+= Ca, Sr, Ba and Ra; RG= He–Rn)

Ab initio calculations were employed to investigate M+ RG2 species, where M+ = Ca, Sr, Ba and Ra and RG= He–Rn. Geometries have been optimized, and cuts through the potential energy surfaces containing each global minimum have been calculated at the MP2 level of theory, employing triple-ζ quality basis sets. The interaction energies for these complexes were calculated employing the RCCSD(T) level of theory with quadruple-ζ quality basis sets. Trends in binding energies, De, equilibrium bond lengths, Re, and bond angles are discussed and rationalized by analyzing the electronic density. Mulliken, natural population, and atoms-in-molecules (AIM) population analyses are presented. It is found that some of these complexes involving the heavier Group 2 metals are bent whereas others are linear, deviating from observations for the corresponding Be and Mg metal-containing complexes, which have all previously been found to be bent. The results are discussed in terms of orbital hybridization and the different types of interaction present in these species