From life cycle talking to taking action

Introduction - The biannual Life Cycle Management conference series aims to create a platform for users and developers of Life Cycle Assessment (LCA) and related tools to share their experiences. A key concern of the LCM community has been to move beyond the production of LCA reports toward using the developed knowledge. This paper reports and evaluates some of the main outcomes of the 4th International Life Cycle Management Conference (LCM 2009). Results - Conference focus: While the focus of the conference was LCM, LCA remains a main analytical tool for supporting LCM. This is clearly shown by the overall program in which roughly half of the contributions focused on or used LCA. Some products and resources and environmental themes were markedly represented in the presentation subjects. Conference participation: The 180 delegates included 40 South Africans, 20 from other African countries, and 140 from as far afield as Brazil, Sweden, Japan, and Australia. The surveyable number of delegates and conference rooms, in combination with the well-balanced scientific and social program, facilitated optimal professional exchange and discussion. Conference structure: LCM 2009 featured some 140 contributions from 47 leading environmental practitioners, consultants, and academic researchers. The interactive conference format included three plenary sessions and training workshops. Conclusions - LCM 2009 successfully engaged with the critical questions of what it means to manage (not merely shift) the environmental and social impacts of global economic activity, what this entails for industry and public services in emerging economies, and how supply chains, networks, and partnerships can be stimulated and managed to deliver truly sustainable practic

The effects of ground hydrology on climate sensitivity to solar constant variations

The effects of two different evaporation parameterizations on the climate sensitivity to solar constant variations are investigated by using a zonally averaged climate model. The model is based on a two-level quasi-geostrophic zonally averaged annual mean model. One of the evaporation parameterizations tested is a nonlinear formulation with the Bowen ratio determined by the predicted vertical temperature and humidity gradients near the earth's surface. The other is the linear formulation with the Bowen ratio essentially determined by the prescribed linear coefficient

The connection between metallicity and metal-line kinematics in (sub-)damped Lyman-alpha systems

A correlation between the metallicity, [M/H], and rest-frame MgII equivalent width, EW, is found from 49 DLAs and strong sub-DLAs drawn from the literature over the redshift range 0.2<z_abs<2.6. The correlation is significant at 4.2 sigma and improves to 4.7 sigma when the mild evolution of [M/H] with redshift is taken into account. Even when including only the 26 DLAs (i.e. excluding sub-DLAs) which have Zn metallicities and EW>0.7A, the correlation remains at >3 sigma significance. Since the MgII2796 transition is predominantly saturated in DLAs (which always have EW greater than 0.3A), EW is far more sensitive to the kinematic spread of the metal velocity components across the absorption profile than it is to [M/H]. Thus, the observed [M/H]--EW correlation points to a strong link between the absorber metallicity and the mechanism for producing and dispersing the velocity components. We also note that approximately half of the 13 known molecular hydrogen absorbers have very high EW and very broad velocity structures which show characteristics usually associated with outflows. Follow-up ultraviolet- and blue-sensitive high-resolution spectra of high-EW systems, initially identified in low-resolution spectra, may therefore yield a large number of new H_2 discoveries.Comment: 9 pages, 2 figures (3 EPS files). Accepted by MNRA

Performance characterization of a segmented anode arcjet thruster

A modular, 1 to 2 kW class arcjet thruster incorporating a segmented anode/nozzle was operated on a thrust stand to obtain performance characteristics of the device and further study its operating characteristics under a number of experimental conditions. The nozzle was composed of five axial conducting segments isolated from one another by boron nitride spacers. The electrical configuration allowed the current delivered to the arcjet to be collected at any combination of segments. Both the current collected by each segment, and the potential difference between the cathode and each segment were monitored throughout the test period. As in previous tests a similar device, current appeared to attach diffusely in the anode when all of the segments were allowed to conduct. Improvements to the device allowed long term (4 to 8 hour) operation at steady-state and operating characteristics were repeatable over extended periods. Performance characteristics indicated that the segmented anode reasonably simulates the behavior of solid anodes of similar geometry. Current distribution depended on flow rate as the arc attachment moved downstream in the nozzle with increases in the mass flow rate. The current level had little effect on current distribution on the anode segments. Thrust measurements indicated that the current distribution in the nozzle did not significantly affect performance of the device

Exploring the relationship between reflectance red edge and chlorophyll content in slash pine

Chlorophyll is a key indicator of the physiological status of a forest canopy. However, its distribution may vary greatly in time and space, so that the estimation of chlorophyll content of canopies or branches by extrapolation from leaf values obtained by destructive sampling is labor intensive and potentially inaccurate. Chlorophyll content is related positively to the point of maximum slope in vegetation reflectance spectra which occurs at wavelengths between 690–740 nm and is known as the “red edge.” The red edge of needles on individual slash pine (Pinus elliottii Engelm.) branches and in whole forest canopies was measured with a spectroradiometer. Branches were measured on the ground against a spectrally flat reflectance target and canopies were measured from observation towers against a spectrally variable understory and forest floor. There was a linear relationship between red edge and chlorophyll content of branches (R2 = 0.91). Measurements of the red edge and this relationship were used to estimate the chlorophyll content of other branches with an error that was lower than that associated with the calorimetric (laboratory) method. There was no relationship between the red edge and the chlorophyll content of whole canopies. This can be explained by the overriding influence of the understory and forest floor, an influence that was illustrated by spectral mixture modeling. The results suggest that the red edge could be used to estimate the chlorophyll content in branches, but it is unlikely to be of value for the estimation of chlorophyll content in canopies unless the canopy cover is high

The role of proton precipitation in Jovian aurora: Theory and observation

It was proposed that the Jovian auroral emissions observed by Voyager spacecraft could be explained by energetic protons precipitating into the upper atmosphere of Jupiter. Such precipitation of energetic protons results in Doppler-shifted Lyman alpha emission that can be quantitatively analyzed to determine the energy flux and energy distribution of the incoming particle beam. Modeling of the expected emission from a reasonably chosen Voyager energetic proton spectrum can be used in conjunction with International Ultraviolet Explorer (IUE) observations, which show a relative lack of red-shifted Lyman alpha emission, to set upper limits on the amount of proton precipitation taking place in the Jovian aurora. Such calculations indicate that less than 10 percent of the ultraviolet auroral emissions at Jupiter can be explained by proton precipitation

History of the Development of Liquid-Applied Coatings for Protection of Reinforced Concrete

Corrosion of reinforcing steel in concrete is an insidious problem for structures at Kennedy Space Center (KSC). KSC is located on the coast of Florida in a highly corrosive atmosphere. Launch pads, highway bridge infrastructure, and buildings are strongly affected. To mitigate these problems, NASA initiated a development program for a Galvanic Liquid-Applied Coating System (GLACS). A breakthrough in this area would have great commercial value in transportation, marine and construction industry infrastructures. The patented NASA GLACS system has undergone considerable testing to meet the needs of commercialization. A moisture-cure coating gives excellent adhesion with ease of application compared to existing galvanic products on the market. The latest development, GalvaCori; can be sprayed or hand applied to almost any structure shape. A self-adhesive conductive tape system has been devised to simplify current collection within the coating areas. In testing programs, millivolt potential and milliamp output per square foot of anode have been closely studied at actual test sites. These two parameters are probably the most challenging items of a resin-based, room-temperature-applied, galvanic coating. Extensive re-formulation has resulted in a system that provides the needed polarization for catholic protection of reinforcing steel in concrete in a variety of structure environments. The rate of corrosion of rebar in concrete is greatly affected by the environment of the structure. In addition to this, for any given concrete structure; moisture level, carbonization, and chloride contamination influences the rate of rebar corrosion. Similarly, the cathodic protection level of galvanic systems is also dependent on the moisture level of the concrete. GalvaCorr is formulated to maintain galvanic activity as the moisture level of the structure declines. GalvaCorr is available as a three-part kit. The mixing step requires about ten minutes. The viscosity can be easily adjusted to meet the application needs. The pot or working life is four to six hours, depending on the temperature. GalvaCorr can be thought of as a spray-on coating, battery ready to provide up to -1.4 volts (relative to CSE) of cathodic protection (CP) potential

Complex Decapod Burrows and Ecological Relationships in Modern and Pleistocene Intertidal Carbonate Environments, San Salvador Island, Bahamas

Burrowing by thalassinidean shrimp in modern tropical, shallow-subtidal to intertidal carbonate environments is widespread and a powerful agent of bioturbation, particularly within sandy substrates. Deep and intense burrowing by callianassids commonly occurs along the intertidal margins of hypersaline lagoons throughout the Bahamas, such as Pigeon Creek on San Salvador Island, where the sediments of extensive sand flats are thoroughly bioturbated by Glypturusacanthochirus. In addition to dominating the deep-tier infauna, G. acanthochirus is a true ecosystem engineer, and its prodigious burrowing activity results in a highly mounded topography. On sand flats, individual sediment cones commonly coalesce with time to form large composite mounds with surfaces stabilized by the development of microbial mats. This unique, biogenetically produced topography sets the stage for colonization by shallow-tier burrowers, particularly the upogebiid shrimp Upogebia vasquezi and several species of fiddler crabs. Burrow systems of U. vasquezi are distinctive and complex. They typically consist of a pair of U-shaped burrows in close proximity or criss-crossing, with knobs or short tunnels at their bases. The entire U-burrow pair is lined by a thick, externally pelleted wall. Inside burrow diameters range from 0.2 to 1 cm, and burrow depths are 10^15 cm, in contrast to the much deeper callianassid burrows. These complex upogebiid burrows also occur as trace fossils in late Pleistocene lagoon-margin facies of the Grotto Beach Formation on San Salvador. Initially reported as fragmentary burrow fills, whole burrow systems virtually identical to the modern upogebiid burrows recently have been found at several localities. These fossil burrows are most abundant in beds lying immediately below a terra rossa paleosol that marks the late Pleistocene^Holocene stratigraphic boundary, and the beds likely were deposited with sea-level stillstand and regression associated with the onset of Wisconsinan glaciation. With their high potential for preservation, these complex upogebiid trace fossils may prove useful as both paleoenvironmental and sea-level position indicators in the study of Quaternary carbonate sequences throughout the Bahamas and other geologically similar regions

Shallow-water reefs in transition: Examples from Belize and the Bahamas

The plight of coral reefs throughout the Caribbean region has been widely reported by reef scientists. A variety of causes has lead to reefal decline, particularly in shallow waters. This study compares the responses of shallow-water reefs in Belize and the Bahamas to outbreaks of white­ band disease (WBD) and traces changes on these reefs to the early 2000s. Prior to the mid-1980s, reef ridges of the Pelican Cays of Belize were constructed of luxu­ riant stands of Acropora cervicomis. As else­ where, this species suffered massive mortality in mid-1980s owing to WBD, and dead A. cervicor­ nis substrates were quickly colonized by Agaricia tenuifolia. Subsequently, A. tenuifolia on the reef ridges was severely affected by the intense El Nino-Southern Oscillation (ENSO)-related bleaching event of 1998. Our surveys showed that \u3e90% of A. tenuifolia colonies died following bleaching. More recent survey data indicate that sponges are aggressively colonizing the coral sub­ strata. In the early 1980s, Telephone Pole Reef on San Salvador Island, Bahamas, had numerous thickets of Acropora cervicomis along with large colonies of Montastraea annularis species com­ plex. By the mid-l 980s, virtually all A. cervicor­ nis colonies were dead, presumably from WBD. Following the demise of the A. cervicomis thick­ ets, an increase in Porites porites colonies quickly occurred. P. porites was opportunistic in coloniza­ tion and showed preference for A. cervicomis substrates. By the early 1990s, P. porites was a dominant coral on Telephone Pole Reef, with col­ ony sizes commonly greater than 1 min diameter. Reef surveys in 1998 and 2000 indicated signifi­ cant decline in the health of P. porites, and in early 2002 continued deterioration was noted, with virtually all larger colonies overgrown by fleshy green macroalgae and/or encrusted by coralline algae. These two examples are similar in that both shallow-water reefs are in rapid transition to domination by non-coral groups that impede set­ tlement of coral larval recruits: sponges in Belize and macro- and coralline algae in the Bahamas. Depending on how widespread similar transitions may be, the future of shallow-water coral reefs throughout the wider Caribbean is problematic. Turnover events such as these have been de­ scribed as unprecedented for coral reefs, and pa­ leontologists should examine the Cenozoic coral reef record in greater detail to explore these claims

How Much Ecological Information is Preserved in Fossil Coral Reefs and How Reliable is it?

The coral reef fossil record is the exclusive database from which analyses of the response of coral communities to environmental change over geological time scales may be gauged. However, few studies have attempted to ascertain whether the reef fossil record is a reasonably accurate representation of a once living coral community. To address this issue, we have performed a systematic comparison of the taxonomic composition and diversity present in exposure of Pleistocene patch reef and reef tract facies found in the Bahamas to that observed for life and death assemblages currently present in analogous modern reefs of the Florida Keys. Results reveal that both modern death assemblages and fossil assemblages preserve the zonation observed on living reefs. However, the taxonomic composition of living reef communities is more closely matched by the fossil assemblages than by the death assemblages. We conclude that the Quaternary record of Caribbean reefs does preserve a reliable account of the long term responses of coral communities to environmental change