The structure of divalent and trivalent cation substituted β-tricalcium phosphate

Current methods of nuclear waste disposal are not suitable for the immobilisation of novel defence-based waste due to the high halogen content resulting from pyrochemical reprocessing. The objective of this thesis was to investigate β-tricalcium phosphate (β- TCP, Ca3(PO4)2) encapsulated in a sodium aluminoborophosphate glass (NABP) matrix as a potential host for this waste using a variety of structural probes. Samples were prepared to determine the structural changes in β-TCP as components of the simulated waste streams were substituted into the material. Zn, Mg, Al, and Ga incorporation was investigated. A combination of X-ray and neutron diffraction was used to determine the changes in long-range order as a function of Zn and Mg substitution up to 13% and 25% cation substitution respectively. Both Zn and Mg substitution caused a contraction of the unit cell up to complete substitution of the Ca(5) site, at which point the contraction ceased. Under further substitution on the Ca(4) site, the a lattice parameter continued to decrease, while the c lattice parameter increased, resulting in an unchanged unit cell volume. Evidence of tricalcium trimagnesium phosphate second phase was observed for the Mg-based compositions above Ca2:8Mg0:2(PO4)2, as has been previously documented, however single phase samples were observed for all Zn-based compositions, in contrast to previous studies. 31P NMR was used to confirm this Ca(5)-Ca(4) substitution model for the Zn-based β-TCP compositions by tightly constrained simulations as a function of composition. A combination of solid-state NMR techniques were used to identify the substitution mechanism of Al and Ga in β-TCP up to the composition Ca9M(PO4)7, where M is Al or Ga respectively. The 31P and 43Ca NMR spectra were simulated as with the divalent cations mentioned above to determine the origin of each resonance in the spectra. Subsequently, 27Al-f31Pg and 71Ga-f31Pg R3-HMQC experiments were performed to explicitly identify substitution on the Ca(5) site only. Studies were also performed to model the NABP:β-TCP interface formed as a result of the encapsulation process, for both pure β-TCP and Ga-substituted β-TCP. To simulate the range of compositions expected at this interface, calcium phosphate and NABP preparations were mixed in proportions from 10 wt:% to 80 wt:% (Ga-substituted) β- TCP. 31P NMR and Raman spectroscopy showed a progressive depolymerisation of the phosphorus network, consistent with the replacement of Al3+ and Na+ with Ca2+. The Al3+ was shown to exist primarily in a 4 coordinated state, showing a tendency to exist within the phosphorus network, whereas 11B NMR showed the B to move from a 4 coordinated site in NABP to a B-rich 3 coordinated environment. Differential thermal analysis showed an increase in the temperature of the two recrystallisation events as a function of both β-TCP and Ga-substituted β-TCP. Studies of the phases present after recrystallisation of the pure β-TCP-based samples showed calcium sodium phosphate and Na Al co-substituted β-TCP for the lower and higher crystallisation temperatures with β-TCP incorporation. For the Ga-containing samples, Na Al Ga co-substituted β-TCP was observed for both crystallisation temperatures. Critically, Ga was shown to displace Al in the β-TCP phase

Social network analysis workshop for water and resource management

April 2014.Includes bibliographical references.Social network analysis (SNA) is a system for studying relationships and transactions between people, organizations, countries, and other entities. The purpose of this CWI project was to research and apply SNA techniques, then develop materials to provide a Fall 2013 half-day introductory workshop in Social Network Analysis for Water and Natural Resources Management at Colorado State University (CSU). The SNA workshop introduced interested students and professionals in engineering, natural resources, agriculture, and other scientific disciplines to complimentary analysis for human dimensions of their work and research through SNA principles and techniques. Complex social-ecological systems cannot be well-studied by only relying on technical analysis of the natural systems. SNA can help analyze how humans interact with resources and their environment and how their ties affect management choices. Social network structure can then be improved to enhance cooperation and innovation. CSU TILT instructional designers were involved in periodic workshop materials review with focus on implementing Research-Based Instructional (RBI) design. The workshop was marketed intensively for three weeks prior to delivery. The most effective means of participant recruitment were word of mouth and group emails, rather than posted flyers or campus-wide online calendars and newsletters. Instead of a traditional classroom, the SNA workshop was held in a conference room that permitted all attendees to sit facing one another around a large oval table, which enhanced participation and shared learning. Expert speakers with real world experience and warnings helped attendees better understand SNA application context and nuance. Providing two smaller sessions, rather than one larger offering, also allowed all attendees to participate more fully, and post-workshop evaluations from the first session were used to improve the second session by most evaluation measures. Follow-up included posting an SNA software demo online using CSU Echo 360 software and expanding other resources and discussion at the SNA Workshop Collaborative website to serve as an ongoing source for learning and sharing. Although not in the scope of the original project, in the Spring of 2014, a half-hour panel brief, a shortened seminar for undergraduates, and SNA software training for graduate students were also tested for SNA technical education merit. The SNA workshop will continue to be refined and tailored to specific CSU departments and programs, and it may be offered to more academic institutions and for other groups and agencies statewide and nationwide. Since attendees felt more time was needed to cover the many related topics and better learn SNA software tools for different applications, the SNA workshop will also be developed into a semester-long course and related textbook

Energy Data Collection and Metering in Texas State Agencies

The State of Texas is probably the largest utility consumer in Texas. Each year, more than 130 separate agencies purchase some form of energy (electricity, natural gas, steam, and hot or chilled water). Annual energy bills for state agencies range from a few hundred dollars to over $20 million, and the total for all agencies is currently near$200 million. To keep pace with the trend of energy consumption in state facilities, the Governor's Energy Management Center (GEMC) requests agencies to mail in energy cost and consumption reports semiannually. This method of energy consumption reporting is proving inadequate, so the GEMC is investigating the use of computerized reporting to obtain this data from state facilities. Similarly, as energy retrofit projects at state facilities become funded, remote monitoring devices to track and document actual energy savings are being considered. A pilot project is underway in conjunction with a cogeneration feasibility study at Austin State Hospital in Austin, Texas. This paper will discuss past, present and future methods of energy data collection for state agencies, and the proposed method of monitoring retrofit projects

Commercial Use Of Wildlife For Conservation

In December 1990, at its General Assembly meeting in Perth, Western Australia, the World Conservation Union (IUCN) carried a resolution entitled "Conservation of wildlife through wise use as a renewable natural resource" (see Appendix). Running to two pages and comprising many clauses and caveats, the crucial part of the resolution is that given in Article 1 ". . . that ethical, wise and sustainable use of some wildlife can provide an alternative or supplementary means of productive land use, and can be consistent with and encourage conservation, where such is in accordance with adequate safeguards . . .". Article 5 refers to the need for the development of guidelines for such use. This was the origin of the workshop's goal. Wildlife can be defined as undomesticated native animals and uncultivated native plants. The commercial use of wildlife may be in the form of harvesting from the wild, ranching or farming. It can be consumptive or non-consumptive and involve a wide range of plant and animal taxa in both terrestrial and aquatic environments. Use can be made of live as well as dead products, both locally and as an export. Sustainability can be defined as the capacity for long-term maintenance of harvests that do not reduce the species' geographic range or existing patterns of genetic variability, or radically alter community structure and function. It should be noted that the commercial use of wildlife is in no way a novelty, with fisheries and forestry providing two striking examples of established commercial use. What is new (or newer), is the notion of identifying conservation benefits from wildlife harvesting, and the possible introduction of hitherto unexploited species for a conservation gain

Osmoregulation by the Broad-Snouted Caiman, "Caiman latirostris", in Estuarine Habitat in Southern Brazil

The broad-snouted caiman Caiman latirostris, of South America mostly frequents freshwater but occurs also in estuaries. Nothing of substance is known of its osmoregulatory physiology but, in the light of accumulating evidence that alligatorids lack specialised adaptations for life in hyperosmotic waters, we anticipated its physiology would be more similar to that of Alligator mississippiensis than the euryhaline Crocodylus porosus, which has both lingual salt glands and a more complex renal:cloacal system. This proved to be the case. Caiman captured in estuaries of the Ilha do Cardoso in southern Brazil were effective hypoosmotic osmoregulators in salinities of 0-24 ppt (seawater = 35 ppt). Plasma osmolarity, sodium and chloride were similar to those in other crocodilians and not influenced by salinity. Plasma urea was low and did not vary with salinity. We found no evidence of lingual or other salt glands. Urinary electrolyte concentrations varied considerably with salinity and in ways reminiscent of A. mississippiensis but very different from C. porosus. Ca. latirostris dehydrated in seawater more rapidly than C. porosus and had substantially higher integumental permeability to water. Caiman did not drink seawater but rehydrated rapidly when returned to freshwater (FW). We found small caiman (< 500 g) only in very low salinities (< 3 ppt) and larger caiman closer to the sea. We postulate that medium to large Ca. latirostris can take advantage of the feeding opportunities presented by the estuarine mangal despite lacking the physiological specialisations of crocodylids. Two individuals which we re-sighted by chance had traveled at least 600m in 2-3 days, showing that every caiman we captured or saw was within easy reach of FW. Most likely their habitation of the estuary and its mangal is achieved through a combination of low surface area:volume ratio, relatively impermeable skin, and periodic access to FW

The nonlocal model of porewater irrigation: Limits to its equivalence with a cylinder diffusion model

Burrows maintained by animals in aquatic sediments ventilate the sediment and can substantially alter the rates and pathways of biologically-mediated decomposition reactions. A well known and effective way of modeling the impact of such bioirrigation in sediment diagenetic models is to assume that solutes diffuse into an annulus of sediment surrounding the burrow; the reaction diffusion equations are represented in cylindrical polar co-ordinates. More commonly, bioirrigation of sediments is represented by one-dimensional nonlocal irrigation models. Their use is typically justified by the assertion that a nonlocal model is equivalent to a radially-integrated two-dimensional diffusion model in cylindrical-polar co-ordinates. In this paper we highlight limits to this equivalence, drawing on examples from both single-species and multiple-species reaction diffusion models. A modified derivation of the nonlocal model using a higher order Taylor series approximation was tested but found to provide little improvement over the original model. We suggest some approaches for choosing nonlocal coefficients and identify particular limitations to be alert to when applying the nonlocal model

Energy Cost Reduction Measures Identified for Texas State Agencies

According t o energy auditors, state-owned facilities in Texas on the average consume over twice the energy of comparable facilities in the private sector. In 1984 and 1986 as part of the Texas Energy Cost Containment Program, two extensive energy audit programs examined a total of 35.3 million square feet of state-owned space. Energy cost reduction measures with paybacks of four years or less were identified. The purpose of this paper is to present the projects identified in 1986. Most relate to lighting, HVAC, and energy management systems. The type of facilities audited include colleges and universities, health science centers, state schools and centers, hospitals, and office buildings. The relation between the facility type and the energy cost reduction measures identified is discussed. In addition, the energy and dollar savings derived from the identified measures at the different facilities are presented. The total savings of the projects identified in both energy audit programs amount to $23.7 million annually

Diversity of Zoanthids (Anthozoa: Hexacorallia) on Hawaiian Seamounts: Description of the Hawaiian Gold Coral and Additional Zoanthids

The Hawaiian gold coral has a history of exploitation from the deep slopes and seamounts of the Hawaiian Islands as one of the precious corals commercialised in the jewellery industry. Due to its peculiar characteristic of building a scleroproteic skeleton, this zoanthid has been referred as Gerardia sp. (a junior synonym of Savalia Nardo, 1844) but never formally described or examined by taxonomists despite its commercial interest. While collection of Hawaiian gold coral is now regulated, globally seamounts habitats are increasingly threatened by a variety of anthropogenic impacts. However, impact assessment studies and conservation measures cannot be taken without consistent knowledge of the biodiversity of such environments. Recently, multiple samples of octocoral-associated zoanthids were collected from the deep slopes of the islands and seamounts of the Hawaiian Archipelago. The molecular and morphological examination of these zoanthids revealed the presence of at least five different species including the gold coral. Among these only the gold coral appeared to create its own skeleton, two other species are simply using the octocoral as substrate, and the situation is not clear for the final two species. Phylogenetically, all these species appear related to zoanthids of the genus Savalia as well as to the octocoral-associated zoanthid Corallizoanthus tsukaharai, suggesting a common ancestor to all octocoral-associated zoanthids. The diversity of zoanthids described or observed during this study is comparable to levels of diversity found in shallow water tropical coral reefs. Such unexpected species diversity is symptomatic of the lack of biological exploration and taxonomic studies of the diversity of seamount hexacorals