Probabilistic life cycle analysis model for evaluating electric power infrastructure risk mitigation investments

One effect of climate change may be increased hurricane frequency or intensity due to changes in atmospheric and geoclimatic factors. It has been hypothesized that wetland restoration and infrastructure hardening measures may improve infrastructure resilience to increased hurricane frequency and intensity. This paper describes a parametric decision model used to assess the tradeoffs between wetland restoration and infrastructure hardening for electric power networks. We employ a hybrid economic input–output life-cycle analysis (EIO-LCA) model to capture: construction costs and life-cycle emissions for transitioning from the current electric power network configuration to a hardened network configuration; construction costs and life-cycle emissions associated with wetland restoration; and the intrinsic value of wetland restoration. Uncertainty is accounted for probabilistically through a Monte Carlo hurricane simulation model and parametric sensitivity analysis for the number of hurricanes expected to impact the project area during the project cycle and the rate of wetland storm surge attenuation. Our analysis robustly indicates that wetland restoration and undergrounding of electric power network infrastructure is not preferred to the “do-nothing” option of keeping all power lines overhead without wetland protection. However, we suggest a few items for future investigation. For example, our results suggest that, for the small case study developed, synergistic benefits of simultaneously hardening infrastructure and restoring wetlands may be limited, although research using a larger test bed while integrating additional costs may find an enhanced value of wetland restoration for disaster loss mitigation.     

Biogeochemical cycles of carbon, sulfur, and free oxygen in a microbial mat

Complete budgets for carbon and oxygen have been constructed for cyanobacterial mats dominated by Microcoleus chthonoplastes from the evaporating ponds of a salt works located in Guerrero Negro, Baja California Sur, Mexico. Included in the budget are measured rates of O2 production, sulfate reduction, and elemental exchange across the mat/brine interface, day and night, at various temperatures and times of the year. We infer from this data the various sinks for O2, as well as the sources of carbon for primary production. To summarize, although seasonal variability exists, a major percentage of the O2 produced during the day did not diffuse out of the mat but was used within the mat to oxidize both organic carbon and the sulfide produced by sulfate reduction. At night, most of the O2 that diffused into the mat was used to oxidize sulfide, with O2 respiration of minor importance. During the day, the internal mat processes of sulfate reduction and O2 respiration generated as much or more inorganic carbon (DIC) for primary production as diffusion into the mat. Also, oxygenic photosynthesis was the most important process of carbon fixation, although anoxygenic photosynthesis may have been important at low light levels during some times of the year. At night, the DIC lost from the mat was mostly from sulfate reduction. Elemental fluxes across the mat/brine interface indicated that carbon with an oxidation state of greater than zero was taken up by the mat during the day and liberated from the mat at night. Overall, carbon with an average oxidation state of near zero accumulated in the mat. Both carbon fixation and carbon oxidation rates varied with temperature by a similar amount. These mats are thus closely coupled systems where rapid rates of photosynthesis both require and fuel rapid rates of heterotrophic carbon oxidation.     

Dynamics of magma in a volcanic conduit — Special emphasis on viscosity of magma with bubbles

A possible dynamic process for magma flow in a volcanic conduit is briefly described. In many of the governing equations, viscosity of magma is involved, and hence, the effective viscosity of magma with small concentration of bubbles was calculated under the assumption of small Reynolds number. The result is $$\eta _\ell = \eta _u (1 + \Phi ),$$ where η_o is the viscosity of a liquid and ? is the volume concentration of bubbles. Thus, the effective viscosity increases with nucleation of gas bubbles in magma. This result reduces the effect of a thermal feedback evele which is postulated as a possible thermodynamical process in viscous magma in a volcanic conduit.     

Zinc content in otoliths of mackerel from the Aegean

The zinc content in otoliths of the mackerel (Scomber japonicus colias) has been determined by instrumental neutron activation analysis. Six groups each of twelve specimens of the same age selected from three areas of the Aegean sea have been analysed. The zinc content was found to be a linear function of the age and body length.     

Untersuchungen mit der Elektronenmikrosonde über die natiirlichen Mischkristallbereiche der Skutterudite

This paper demonstrates with approximately 140 electron micro probe analyses of minerals from the classic localities the areas of solid solution in the ternary diagram of the natural iron-cobalt-nickel-skutterudites. The skutterudites analyses show a. much more scattered pattern over all the diagram than presumed by the analyses or by the experimental determined areas of solid solution in the recent literature. Furthermore, a fluctuation in the metalarsenic-ratio between 1:1.9 to 1:3.3 was ascertained for this mineral type. The iron-skutterudites favour the lower metal-arsenic-ratios, the cobalt-skutterudites and respectively the cobalt-nickel-skutterudites more the medium, and the nickel-skutterudites more the higher ratios.With solely microscopic determination of the iron-skutterudite mineral phase an error could be possible, whereas the determination of the nearly pure nickee-skutterudite (which is a new mineral phase) seems certain to the author.Finally, the author tries to explain the extreme fluctuation of stochiometry in the same structure to be caused by a chiefly metalic bond in an alloy type.Zusammenfassung Anhand von über 140 Mikrosondenanalysen von Mineralien der klassischen Vorkommen wird in dieser Arbeit versucht die Mischkristallfelder im Dreieckdiagramm der natütlichen Eisen-Kobalt-Nickel-Skutterudite zu ermitteln. Dabei zeigte sick einmal eine wesentlich größere Streuung der Skutteruditanalysen, als dies aus den Analysenangaben und den experimentell bestimmten Mischkristallfeldern der bisherigen Literatur zu vermuten war. Weiterhin konnte ein außergewohnliches Schwanken des Metall-Arsenverhaltnisses zwischen etwa 1:1,9 bis 1: 3,3 bei dieser Mineralart festgestellt werden. Es zeigte sich, daß die niederen Metall-Arsenverhältnisse bevorzugt an die Eisen-Skutterudite, die mittleren mehr an die Kobalt-Skutterudite bzw. an die Kobalt-Nickel-Skutterudite und die höheren bevorzugt an die eigentlichen Nickel- Skutterudite gebunden sind.Während bei den Eisen-Skutteruditen aufgrund der rein mikroskopischen Bestimmung die Möglichkeit eineir Fehldiagnose nicht völlig ausgeschlossen werden kann, erscheint der Nachweis eines fast reinen Nickel- Skutterudites dem Verfasser als gesichert.Das kristallchemisch interessante Problem, wie these großen Stöchiometrie-schwankungen in ein und derselben Struktur ohne wesentliehe Änderungelr auftreten können, versucht der Verfasser durch eine vorwiegend metallische Bindung in einem Legierungstyp zu erklären.

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Diese Arbeit wurde auszugsweise am 9. September 1964 vor der Deutschen Mineralogischen Gesellschaft auf deren Jahrestagung in Wiesbaden vorgetragen.     

THE TROPICS: ENVIRONMENTS AND HUMAN IMPACTS UNDERSTOOD AND REINTERPRETED

In the 1950s, few people had travelled widely through different parts of the tropics and interpretations on tropical landforms, soils, vegetation and climate largely rested on impressions gained from residence or long sojourns in particular tropical countries. Most academic geography on the tropics was then written by expatriates and lacked the perspective gained from long experience of tropical regions. Particular problems of understanding arose as people attempted to extrapolate from one part of the tropics to another. Since then, understanding has advanced enormously, largely through the efforts of tropical scientists working in their own institutions and through the greater technological ability to study tropical lands both remotely and through easier field access. The establishment of a number of field stations, aimed primarily at the biological sciences, but also facilitating the work of geographers, has been a major stimulus to this effort. Concerns over practical issues, particularly local development and global climatic change have prompted new avenues of research, many of which have been assisted by the great increase in data collection in tropical countries. For the future, South-South dialogue between tropical physical geographers is needed to improve their ability to ask meaningful questions so that they can contribute to teach the rest of their discipline more about serious applied and applicable geography.