Lanthanide Ionization Energies and the Sub-Shell Break. Part 2. The Third and Fourth Ionization Energies

By interpolating a 4fq6s → 4fq7s transition within the sequence f1 → f14 rather than between f0 and f14, revised third and fourth ionization energies of the lanthanides have been obtained. The revised values, together with the second ionization energies calculated in a previous paper, are used to calculate values of the standard enthalpies of formation of the gaseous tripositive ions, ΔfHƟ(M3+,g), and of the lattice and hydration enthalpies of some lanthanide compounds and ions in the trivalent and tetravalent states. The displacements of f0 values from nearly smooth f1 → f14 variations exceed 30 kJ mol-1 and indicate substantial subshell breaks

Valencies of the lanthanides

The valencies of the lanthanides vary more than was once thought. In addition to valencies associated with a half-full shell, there are valencies associated with a quarter- and three-quarter-full shell. This can be explained on the basis of Slater’s theory of many-electron atoms. The same theory explains the variation in complexing constants in the trivalent state (the “tetrad effect”). Valency in metallic and organometallic compounds is also discussed

Scale as a Transaction Cost Variable in the U.S. Biopower Industry

With increasing interest in renewable energy from agriculture, including biopower and cellulose ethanol, several aspects of the industry must be understood. Study of the organization of the biopower industry represents an under researched area and a new application of transaction cost theory to an emerging industry. Refinement of the theory can also result from challenging applications. This article provides an application of transaction cost economics to the existing United States biopower industry while challenging the empirical convention of excluding production cost variables from transaction cost analysis. Utilizing survey data from 53 biopower generators, scale is modeled as a transaction cost variable in explaining the choice of organizational from. Consistent with transaction cost theory, the probability of observing internal organization is found to be negatively correlated to scale. Given this evidence, this article reconsiders the impact of scale and transaction costs on the choice of organizational from.Resource /Energy Economics and Policy,

Holocene Paleohydrology of the St. Elias Mountains, British Columbia and Yukon

The evolution of the Holocene paraglacial environment of the St. Elias Mountains has been dominated by hydrological variations which modify the direct glacial depositional environment and trigger instabilities in valley side glacial and talus deposits. Data from the Kaskawulsh Glacier demonstrate how discharge and sediment transport regimes vary through the season, as sediment is flushed out of the system, and a marginal to subglacial drainage change of the Grizzly Creek Glacier illustrates the effects of extraordinary events in transporting large volumes of sediment. A multiple glacier fluctuation model applied to the region produces rapid temporal changes in discharge and sediment regimes throughout the Holocene. The effect of these variations is enhanced by the occurrence of surges of many of the glaciers of the St. Elias Mountains and by sequences of glacier dammed lake formation and drainage in the region.L'évolution de l'environnement paraglaciaire des monts Saint-Élie, à l'Holocène, sous le contrôle des variations du régime hydrologique qui ont à la fois modifié le milieu immédiat de dépôt de sédiments glaciaires et provoqué l'instabilité des dépôts et des éboulis sur les versants des vallées. Les données recueillies au glacier de Kaskawulsh ont permis de constater que les régimes d'écoulement et du transport des sédiments varient au cours d'une saison donnée, pendant que les sédiments sont évacués hors de l'appareil. De plus, le passage d'un drainage de type juxtaglaciaire à un drainage de type sous-glaciaire le long du glacier de Grizzly Creek illustrent bien les effets des variations excessives de volume de sédiments transportés. L'application à la région à l'étude d'un modèle de fluctuations multiples explique les changements rapides qu'ont connus les régimes d'écoulement et du transport des sédiments, survenus tout au long de l'Holocéne. L'impact de ces changements a été accentué par l'avancée rapide de nombreux glaciers des monts Saint-Élie et par la formation d'une série de lacs de barrage glaciaire et de leur vidange.Die Entwicklung der paraglazialen Umgebung der St. Elias Mountains im Holozàn war von hydrologischen Variationen beherrscht, welche das direkte glaziale Ablagerungs-Milieu verândert haben und die Unstabilitât der Eis- und Halden-Ablagerungen an den Talseiten ausgelôst haben. Daten vom Kaskawulsh-Gletscher zeigen, wie die Verhâltnisse des Fliefiens und des Sediment-transports innerhalb einer Saison variieren, wàhrend Sediment aus dem System herausgespùlt wird; und ein Wechsel von Rand-Entwàsserung zu subglazialer Entwàsserung am Gizzly Creek Gletscher illustriert die Auswirkungen von auperordentlichen Ereignissen beim Transport von gropen Sediment-Volumen. Ein auf die Region angewendetes Modell multipler Gletscher-Fluktuation weist schnelle zeitliche Wechsel auf im FlieBen und im Sediment-Transport wàhrend des ganzen Holozàn. Die Auswirkung dieser Variationen wird durch Fluten vieler Gletscher der St. Elias Mountains verstàrkt und durch Serien von durch Gletscher-Stau gebildeten Seen und ihrer Entwàsserung

Mass Movement Processes in Metalline Creek, Southwest Yukon Territory

In Metalline Creek, a small valley in the Kluane Range of the southwest Yukon Territory, the glacial deposits and the talus material have been affected by mass movement processes promoted by the occurrence of glacier ice and ice formed from avalanche snow. In addition, minor periglacial mass movement processes occur in the valley. Variations in the type of process are attributed to altitudinal changes, to aspect, and to change in the height of the regional snow line during the Neoglacial period

Eurasian watermilfoil biomass associated with insect herbivores in New York

A study of aquatic plant biomass within Cayuga Lake, New York spans twelve years from 1987-1998. The exotic Eurasian watermilfoil ( Myriophyllum spicatum L.) decreased in the northwest end of the lake from 55% of the total biomass in 1987 to 0.4% in 1998 and within the southwest end from 50% in 1987 to 11% in 1998. Concurrent with the watermilfoil decline was the resurgence of native species of submersed macrophytes. During this time we recorded for the first time in Cayuga Lake two herbivorous insect species: the aquatic moth Acentria ephemerella , first observed in 1991, and the aquatic weevil Euhrychiopsis lecontei , first found in 1996 . Densities of Acentria in southwest Cayuga Lake averaged 1.04 individuals per apical meristem of Eurasian watermilfoil for the three-year period 1996-1998. These same meristems had Euhrychiopsis densities on average of only 0.02 individuals per apical meristem over the same three-year period. A comparison of herbivore densities and lake sizes from five lakes in 1997 shows that Acentria densities correlate positively with lake surface area and mean depth, while Euhrychiopsis densities correlate negatively with lake surface area and mean depth. In these five lakes, Acentria densities correlate negatively with percent composition and dry mass of watermilfoil. However, Euhrychiopsis densities correlate positively with percent composition and dry mass of watermilfoil. Finally, Acentria densities correlate negatively with Euhrychiopsis densities suggesting interspecific competition

Python bindings for the open source electromagnetic simulator Meep

Meep is a broadly used open source package for finite-difference time-domain electromagnetic simulations. Python bindings for Meep make it easier to use for researchers and open promising opportunities for integration with other packages in the Python ecosystem. As this project shows, implementing Python-Meep offers benefits for specific disciplines and for the wider research community

Scale and Transaction Costs in the U.S. Biopower Industry

Includes bibliographical references.With increasing interest in renewable energy from agriculture, including biopower and cellulose ethanol, there is a need for better understanding of the economic organization of this emerging industry. Study of the organization of the biopower industry represents an under-researched area and a new application of transaction cost theory to an emerging industry. Refinement of the theory can also result from challenging applications. This article provides an application of transaction cost economics to the existing United States biopower industry while challenging the empirical convention of excluding production cost variables from transaction cost analysis. Utilizing survey data from 53 biopower generators we study the relationship between physical asset specificity, site specificity, and scale in explaining firms' decisions to procure inputs internally, externally, or to use both methods. Consistent with transaction cost theory, both site specificity and scale are good predictors of organizational form. Given this evidence, this article reconsiders the impact of scale and transaction costs on the choice of organizational form