The Alaska experience

The management responsibilities of the Alaska Department of Natural Resources are summarized and the establishment of a geoprocessor system is described. Specific capabilities were defined based on surveys of potential users and pre-existing systems. The procurement process, the initially purchased equipment, and system upgrading are described. Cost, installation and maintenance, site location, training, and staffing of the system are examined

A regional land use survey based on remote sensing and other data: A report on a LANDSAT and computer mapping project, volume 1

The author has identified the following significant results. New LANDSAT analysis software and linkages with other computer mapping software were developed. Significant results were also achieved in training, communication, and identification of needs for developing the LANDSAT/computer mapping technologies into operational tools for use by decision makers

A regional land use survey based on remote sensing and other data: A report on a LANDSAT and computer mapping project, volume 2

The author has identified the following significant results. The project mapped land use/cover classifications from LANDSAT computer compatible tape data and combined those results with other multisource data via computer mapping/compositing techniques to analyze various land use planning/natural resource management problems. Data were analyzed on 1:24,000 scale maps at 1.1 acre resolution. LANDSAT analysis software and linkages with other computer mapping software were developed. Significant results were also achieved in training, communication, and identification of needs for developing the LANDSAT/computer mapping technologies into operational tools for use by decision makers

An Amenity Assessment Model for Evaluating State Park Tourism Assets

Creative, quick and inexpensive assessment models based on sound methods that yield practical applications can be of great utility to the administrators of both public and private sector outdoor recreation resources in their decision-making tasks. This paper presents a case study on the development of a tourism amenity assessment model designed for application to state and regional parks and historic sites. The five-step process utilized in developing and applying the model is discussed. The findings yielded as a result of application of the model to state parks in southeastern Georgia (USA) are enumerated, and the recommendations made to Georgia Department of Natural Resources decision makers are presented. A concluding discussion identifies the wider managerial utility of the model

A regional land use survey based on remote sensing and other data: A report on a LANDSAT and computer mapping project, volume 3

For abstract, see N78-17444

First-principles analysis of the interplay between electronic structure and volume change in colquiriite compounds during Li intercalation

A main source of capacity fading in lithium-ion batteries is the degradation of the active cathode materials caused by the series of volume changes during charge and discharge cycles. The quaternary colquiriite-type fluorides Li$_x$CaFeF$\mathrm{_6}$ and Li$_x$CaCoF$\mathrm{_6}$ were reported to have negligible volume changes in specific Li concentration ranges, making the underlying colquiriite structure a promising candidate for so-called zero-strain behavior. Using first-principles electronic structure calculations based on density functional theory with a Hubbard-$U$ correlation correction on the transition-metal ions, we systematically investigate the equilibrium volumes of the colquiriite-type fluorides Li$_x$CaMF$\mathrm{_6}$ with M =Ti, V, Cr, Mn, Fe, Co, and Ni at the Li concentrations $x$=0, 1, and 2. We elucidate the connection between the total volume of the structures and the local volumes of fluorine coordinated octahedra around the cations, and we find trends along the series of the 3d transition-metal elements. In the lithiation step from $x$=1 to $x$=2 we find volume changes of about 10 %, and we discuss the discrepancy to the experimentally reported smaller value for Li$_x$CaFeF$\mathrm{_6}$. From $x$=0 to $x$=1 we describe the compensating structural mechanisms that lead to an exceptionally small volume change of Li$_x$CaMnF$\mathrm{_6}$. This compound is therefore a particularly promising zero-strain cathode material.Comment: 13 pages, 9 Figure

A modular magnetic anastomotic device for minimally invasive digestive anastomosis: proof of concept and preliminary data in the pig model.

BACKGROUND: The aim of our study was to assess the feasibility of minimally invasive digestive anastomosis using a modular flexible magnetic anastomotic device made up of a set of two flexible chains of magnetic elements. The assembly possesses a non-deployed linear configuration which allows it to be introduced through a dedicated small-sized applicator into the bowel where it takes the deployed form. A centering suture allows the mating between the two parts to be controlled in order to include the viscerotomy between the two magnetic rings and the connected viscera. METHODS AND PROCEDURES: Eight pigs were involved in a 2-week survival experimental study. In five colorectal anastomoses, the proximal device was inserted by a percutaneous endoscopic technique, and the colon was divided below the magnet. The distal magnet was delivered transanally to connect with the proximal magnet. In three jejunojejunostomies, the first magnetic chain was injected in its linear configuration through a small enterotomy. Once delivered, the device self-assembled into a ring shape. A second magnet was injected more distally through the same port. The centering sutures were tied together extracorporeally and, using a knot pusher, magnets were connected. Ex vivo strain testing to determine the compression force delivered by the magnetic device, burst pressure of the anastomosis, and histology were performed. RESULTS: Mean operative time including endoscopy was 69.2 ± 21.9 min, and average time to full patency was 5 days for colorectal anastomosis. Operative times for jejunojejunostomies were 125, 80, and 35 min, respectively. The postoperative period was uneventful. Burst pressure of all anastomoses was ≥ 110 mmHg. Mean strain force to detach the devices was 6.1 ± 0.98 and 12.88 ± 1.34 N in colorectal and jejunojejunal connections, respectively. Pathology showed a mild-to-moderate inflammation score. CONCLUSIONS: The modular magnetic system showed enormous potential to create minimally invasive digestive anastomoses, and may represent an alternative to stapled anastomoses, being easy to deliver, effective, and low cost

Architecture of on- and off-axis magma bodies at EPR 9°37–40′N and implications for oceanic crustal accretion

Crustal accretion at fast-spreading mid-ocean ridges is believed to be concentrated in a narrow zone up to a few kilometers wide centered beneath the ridge axis. However, there is increasing evidence for off-axis magmatism occurring beyond this narrow zone. Here, we present 3D multichannel seismic (MCS) images from the East Pacific Rise 9°37–40′N extending to 11 km on the ridge flanks. In the axial region, two offset axial magma bodies underlie a small ridge-axis discontinuity at ∼9°37′N, displaying an overlapping geometry similar to that of the seafloor structures above. On the ridge flanks, a series of off-axis magma lenses (OAML) are imaged: they are located 2–10 km from the ridge axis, at 700 to 1520 ms two-way travel time below seafloor (bsf) (∼1.6 to 4.5 km bsf), with variable areas ranging from 0.5 km2 to 5.2 km2. The largest body is centered 4 km east of the ridge axis and is composed of a large, continuous, flat-topped lens and a series of small, discontinuous, westward-dipping bodies along its western edge. The flat crest of the OAML lies at approximately the same depth beneath layer 2A as the axial magma lens and we infer that this OAML has formed by aggregation of ascending melts that accumulate at the base of the sheeted dike section. A cluster of reflections underlying the OAML at 1260–1510 ms bsf are observed that may be deeper lenses feeding melts to the upper lens. This largest OAML is associated with Moho travel time anomalies of 120–260 ms within a zone that extends up to 2 km from the edge of the OAML, suggesting a lower crust that is partially molten with lower crustal velocities reduced by 8–18% and/or thicker than normal by up to 1 km. Local volcanic edifices are found above two of the three OAMLs imaged in our study area and are inferred to be the eruptive products of the OAMLs. From the volume of these edifices and the Moho travel time anomalies we estimate the potential contribution of off-axis magmatism to the total volume of the crust to be ∼0.01–3%. The OAMLs imaged in our study area are present over roughly the same distance range as the zone of formation of near-axis seamounts. We speculate that OAMLs and the volcanic edifices found above them are small-scale manifestations of the off-axis magmatism that gives rise to near-axis seamounts

Weak Gravity Conjecture and Holographic Dark Energy Model with Interaction and Spatial Curvature

In the paper, we apply the weak gravity conjecture to the holographic quintessence model of dark energy. Three different holographic dark energy models are considered: without the interaction in the non-flat universe; with interaction in the flat universe; with interaction in the non-flat universe. We find that only in the models with the spatial curvature and interaction term proportional to the energy density of matter, it is possible for the weak gravity conjecture to be satisfied.Comment: 14 pages, 7 figures, typographical errors are corrected; conclusin is unchange