Differential Thermal Analysis Investigation of the High-Low Cristobalite Inversion Under Hydrostatic Pressure to 7 Kbar

The high-low inversion in polycrystalline cristobalite, synthesized from quartz at 1500°C, was investigated by differential thermal analysis to 7 kbar in hydrostatic apparatus. A region of anomalous curvature ( d²T/dp² >0) exists to ∼1 kbar; at higher pressure, the low→high and high→low transition temperatures vary linearly with pressure, with slopes of ∼51.₁ and 53. ₆ deg kbar⁻¹, respectively. Extrapolated 1-bar intercepts are ∼232° and ∼209°C, respectively. It is concluded that high cristobalite is less compressible than low cristobalite near the inversion. The hysteresis between the high→low and low→high transition temperatures decreases with increasing pressure.     

Automated tracing and volume measurements of neurons from 3-D confocal fluorescence microscopy data

Three-dimensional (3-D) image analysis algorithms and experimental results that demonstrate the feasibility of fully automated tracing of neurons from fluorescence confocal microscopy data are presented. The input to the automated analysis is a set of successive optical slices that have been acquired using a confocal scanning laser microscope. The output of the system is a labelled graph representation of the neuronal topology that is spatially aligned with the 3-D image data. A variety of topological and metric analyses can be carried out using this representation. For instance, precise measurements of volumes, lengths, diameters and tortuosities can be made over specific portions of the neuron that are specified in terms of the graph representation. The effectiveness of the method is demonstrated for a set of sample fields featuring selectively stained neurons. Additional work will be needed to refine the method for unsupervised use with complex data involving multiple intertwined neurons and extremely fine dendritic structures.     

Wigner equation of motion for time-dependent potentials

The equation of motion is obtained for the Wigner distribution for time-dependent potentials. It is shown that one cannot obtain an equation of motion for the standard Wigner distribution but one can do so for the fourdimensional distribution of the variables position, momentum, time, and frequency. Three forms are given and it is shown that for time-independent potentials the new form reduces to the equations originally obtained by Wigner and Moyal.     

POWER-LAW FLUIDS IN POROUS MEDIA

An analysis is presented to describe the parallel flow of power-law fluids within a channel bounded by porous media. It is shown that there is an excess flow above the Darcy's law prediction for the porous medium region adjacent to the channel/ porous medium boundary. This also leads to a higher flow rate in the channel. The excess flow increases with a decreasing value of the power law index, and with increasing permeability. The excess flow is found to reach a maximum at an intermediate value of the dimensionless channel width (=½H/K^½and it vanishes in the limit of h→∞and h→0. Experimental evidence is also presented to demonstrate the excess flow. The experimental data are found to be in reasonable agreement with the proposed flow model.     

Estimating the age and structure of forests in a multi-ownership landscape of western Oregon,U.S.A.

Forests of the Pacific Northwest region of the U.S.A. are part of an ongoing political debate that focuses on the trade-offs between commodity and non-commodity values. A key issue in this debate is the location and extent of closed canopy mature and old-growth forest remaining in the region. Remote sensing can play a major part in locating mature and old-growth forests, but. several challenges must be overcome to do so with acceptable accuracy. Conifer forests of the region have high leaf area indices. Thus, most incident solar energy is absorbed, making these forests difficult targets for discrimination of classes. Additionally, spectral characteristics can be affected more by the effects of steep topography than condition of the closed canopy forest.

Experimenting with a number of techniques, we estimated and mapped forest age and structure in 1988 over a 1 237 482 ha area on the west side of the Oregon Cascade Range with an overall accuracy of 82 per cent. Unsupervised classification enabled several forest classes to be defined in terms of per cent cover: open (0-30 per cent), semi-open (30-85 per cent), closed mix (> 85 per cent, of which at least 10 percent is comprised of non-conifer species), and closed conifer (> 85 per cent, of which less than 10 per cent is non-conifer). These classes represented nearly distinct spectral groups. Within the closed canopy conifer class, between two and three age and structural classes could be distinguished using regression analysis (e.g., young, mature, and old-growth). Defining more classes seriously degraded map accuracies. The Tasseled Cap wetness index was not sensitive to topography, and yielded more accurate results in closed canopy conifer stands than Tasseled Cap brightness or greenness, even when regression models using these indices were based on solar incidence angle stratification.

The multi-ownership study area consisted of 76 per cent forestland. Of the total forestland, 70 per cent was closed canopy conifer, with 42 per cent being in a mature or old-growth state. Forests administered by the USD1 Bureau of Land Management (BLM) and the USDA Forest Service, but protected by congressional and administrative mandates from harvest, were 10 per cent of the total forestland. Of the protected category, only 60 per cent was mature and old-growth forest, Unprotected BLM and Forest Service lands accounted for 53 per cent of the forestland in this study (8 and 45 per cent, respectively). Of the unprotected category, the BLM had 63 per cent, and the Forest Service had 49 per cent, respectively, of their holdings in a pre-canopy closure and young conifer condition. Thirty-five per cent of the forestland was privately owned, and consisted of 73 per cent pre-canopy closure and young conifer forest stands. Of all mature and old-growth forest, 22 per cent was found on private land, 7 per cent on unprotected BLM land, 55 per cent on unprotected Forest Service land, and 15 per cent on protected land.     

PERSONALITY AND TIME ATTITUDES.

ADMINISTERED SETS OF PERSONALITY AND TIME-ATTITUDE ITEMS TO 100 HOSPITALIZED PSYCHIATRIC PATIENTS, 100 PSYCHIATRIC PATIENTS IN A MENTAL HYGIENE CLINIC AND 116 COLLEGE MALES AND 192 FEMALES. THE SETS WERE SEPARATELY FACTOR ANALYZED IN THE TOTAL SAMPLE, AND THE DATA FACTOR SCORED. SUBSTANTIAL RELATIONSHIPS WERE FOUND BETWEEN PERSONALITY AND TIME-ATTITUDE FACTOR SCORES WITHIN SAMPLES, AND MODERATE RELATIONSHIPS OF BOTH KINDS WITH DIAGNOSTIC AND DEMOGRAPHIC VARIABLES. RESULTS EMPIRICALLY SUPPORT THE CONJECTURE THAT ATTITUDES TOWARD TIME REFLECT BASIC FEATURES OF THE INDIVIDUAL PERSONALITY. (24 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

OPTIMAL OPERATION OF MULTIQUALITY WATER SUPPLY SYSTEMS-III: THE Q-C-H MODEL

A new technique for optimal operation of multiquality water supply systems is proposed. The technique, which is known as a Q-C-H (flow-quality-head) model, combines previously developed Sow-quality (Q-C) and flow-head (Q-H) models for optimal operation of water supply systems. The decision variables in the model are the operation of treatment plants, pumps and valves. The model minimizes the cost of water at sources, treatment, energy, and loss of agricultural yield when water quality is low. The model uses an iterative modified projected gradient method combined with the Complex method. As in the Q-C and Q-H models, the solution method is based on decomposition, dis-aggregation/aggregation approach, involving internal and external optimization. The decision variables of the external model are the flows in the loops of the network and the removal ratios at the treatment plants. The operation of the pumps and valves are the decision variables of the internal model. The method is demonstrated by application to an example problem.