LANDSAT/coastal processes

The author has identified the following significant results. Correlations between the satellite radiance values water color, Secchi disk visibility, turbidity, and attenuation coefficients were generally good. The residual was due to several factors including systematic errors in the remotely sensed data, errors, small time and space variations in the water quality measurements, and errors caused by experimental design. Satellite radiance values were closely correlated with the optical properties of the water

Combination of geodetic observations and models for glacial isostatic adjustment fields in Fennoscandia

We demonstrate a new technique for using geodetic data to update a priori predictions for Glacial Isostatic Adjustment (GIA) in the Fennoscandia region. Global Positioning System (GPS), tide gauge, and Gravity Recovery and Climate Experiment (GRACE) gravity rates are assimilated into our model. The technique allows us to investigate the individual contributions from these data sets to the output GIA model in a self-consistent manner. Another benefit of the technique is that we are able to estimate uncertainties for the output model. These are reduced with each data set assimilated. Any uncertainties in the GPS reference frame are absorbed by reference frame adjustments that are estimated as part of the assimilation. Our updated model shows a spatial pattern and magnitude of peak uplift that is consistent with previous models, but our location of peak uplift is slightly to the east of many of these. We also simultaneously estimate a spatially averaged rate of local sea level rise. This regional rate (similar to 1.5 mm/yr) is consistent for all solutions, regardless of which data sets are assimilated or the magnitude of a priori GPS reference frame constraints. However, this is only the case if a uniform regional gravity rate, probably representing errors in, or unmodeled contributions to, the low-degree harmonic terms from GRACE, is also estimated for the assimilated GRACE data. Our estimated sea level rate is consistent with estimates obtained using a more traditional approach of direct "correction" using collocated GPS and tide gauge site

Student Government and the University Administrative Agenda Alignment

Within institutions of higher education, shared governance is an essential component to a healthy functionality. Among the many stakeholders at these institutions, students are the largest in number and hold primacy. Participation in student governance establishes a sense of shared ownership over their communities while also providing a unique avenue for students to gain wisdom and develop critical skill sets. Senior administrators at these institutions have many inherent challenges due to an organization that is largely decentralized and autonomous. The purpose for conducting this study was to analyze Student Government Associations (SGA) at 8 select land-grant institutions of higher education in order to establish the extent of administrative agenda alignment after reviewing policy priorities for SGAs and their respective presidents. The study ultimately found minimal agenda alignment between student body presidents and university presidents. Student body presidents indicated that they did not necessarily anticipate alignment given the differences in their constituencies and most indicated positive relationships. These findings emphasize the importance of shared governance within these institutions. Positive relationships between SGAs and their presidents emphasize constructive communication and reciprocity between the subjects which leads to more buy-in by stakeholders and innovative ideas

Force distribution for double-walled carbon nanotubes

Advances in technology have led to the creation of many nano-scale devices and carbon nanotubes are representative materials to construct these devices. Double-walled carbon nanotubes with the inner tube oscillating can be used as gigahertz oscillators and form the basis of possible nano-electronic devices. Such gigahertz oscillating devices made from carbon nanotubes might be instrumental in the micro-computer industry, which is predominantly based on electron transport phenomena. There are many experiments and molecular dynamics simulations which show that a wave is generated on the outer cylinder by the oscillation of the carbon nanotubes and that the frequency of this wave is also in the gigahertz range. However, conventional applied mathematical modelling techniques are generally lacking. In order to analyse and model such devices, it is necessary to estimate accurately the resultant force distribution due to the inter-atomic interactions. Here, we find the van der Waals force using the Lennard-Jones potential to calculate the oscillation frequency using Newton\u27s second law for double-walled carbon nanotubes of any length of the inner and the outer tubes, 2L1 and 2L2, respectively. These results are based on work by the present authors derived in (Baowan and Hill)

Mathematical modelling in nanotechnology

The interaction of nano particles with conventional materials dramatically changes all the physical parameters, which usually characterize the bulk material. The nano particles constitute highly reactive isolated sites to the extent that it leads to a change in the electronic structure of the nano composite, and accordingly all the physical properties, such as thermal, mechanical and electrical properties become different from those of the bulk material. To successfully exploit nano composites as components and devices, this fundamental shift of physical properties must be properly understood and accurately modelled. While experimentation is crucial, a theoretical understanding is also necessary and with changed physical parameters, existing continuum theories may still be able to capture critical phenomena. This paper provides an introduction to some of the issues and the theoretical developments in nanotechnology involving the three topics of the enhanced thermal conductivity of nanofluids, electrorheological fulids and the mechanics of carbon nanotubes. It is presented with a view to identifying those areas where applied mathematical modelling might yield important insights

A mathematical model for heat transfer in grain store microclimates

Australia's reputation as a supplier of insect-free grain is being threatened by Psocids ( Liposcelis spp.), an insect pest which is wreaking havoc within the Australian grain industry. These pests are very mobile and appear to move in and out of infested grain bulks in response to variations in temperature. This movement is the cause of much difficulty in controlling these insects so an understanding of what happens to the heat transfer at the surface of the grain bulk would allow a better understanding of the observed behaviour by these insects. Here we examine the heat transfer at the grain store surface and the grain bulk surface. A heat transfer variant of the theory of "double-diffusivity" is developed, which is a mathematical model that assumes two separate diffusion paths; one for high-diffusivity and one for regular-diffusivity. This approach takes into consideration the fact that the rate of heat transfer through the grain is different to that through the interstitial air surrounding the grain. Based on a heat-balance approach, approximate analytical results are obtained from which the overall variation in temperature close to the grain store wall may be calculated. The behaviour for typical parameter values is shown graphically

Generalised Einstein mass-variation formulae: II Superluminal relative frame velocities

AbstractIn part I of this paper we have deduced generalised Einstein mass variation formulae assuming relative frame velocities v<c. Here we present corresponding new expressions for superluminal relative frame velocities v>c. We again use the notion of the residual mass m0(v) which for v>c is defined by the equation m(v)=m0(v)[(v/c)2-1]-1/2 for the actual mass m(v). The residual mass is essentially the actual mass with the Einstein factor removed, and we emphasise that we make no restrictions on m0(v). Using this formal device we deduce corresponding new mass variation formulae applicable to superluminal relative frame velocities, assuming only the extended Lorentz transformations and their consequences, and two invariants that are known to apply in special relativity. The present authors have previously speculated a dual framework such that both the rest mass m0∗ and the residual mass at infinite velocity m∞∗ (by which we mean p∞∗/c, assuming finite momentum at infinity) are equally important parameters in the specification of mass as a function of its velocity, and the two arbitrary constants can be so determined. The new formulae involving two arbitrary constants may also be exploited so that the mass remains finite at the speed of light, and two distinct mass profiles are determined as functions of their velocity with the rest mass assumed to be alternatively prescribed at the origin of either frame. The two profiles so obtained (M(U),m(u)) and (M∗(U),m∗(u)) although distinct have a common ratio M(U)/M∗(U)=m(u)/m∗(u) that is a function of v>c, indicating that observable mass depends upon the frame in which the rest mass is prescribed

Electronic properties of silicon nanotubes with distinct bond lengths

We analyze the band structure of a silicon nanotube with sp^3 bonds and variable bond lengths. This nanotube has many similarities with a carbon nanotube including a band gap at half-filling and conducting behavior which is dependent on structure. We derive a simple formula which predicts when the nanotube is metallic. We discuss our results in the context of a nanotube subject to small applied strains as this provides a means of distorting bond lengths in a predictable way and may be tested experimentally. The affects of strain on nanotube conductance has important implications for sensor technology

Characterization of site-specific GPS errors using a short-baseline network of braced monuments at Yucca Mountain, southern Nevada

We use a short-baseline network of braced monuments to investigate site-specific GPS effects. The network has baseline lengths of ∼10, 100, and 1000 m. Baseline time series have root mean square (RMS) residuals, about a model for the seasonal cycle, of 0.05–0.24 mm for the horizontal components and 0.20–0.72 mm for the radial. Seasonal cycles occur, with amplitudes of 0.04–0.60 mm, even for the horizontal components and even for the shortest baselines. For many time series these lag seasonal cycles in local temperature measurements by 23–43 days. This could suggest that they are related to bedrock thermal expansion. Both shorter-period signals and seasonal cycles for shorter baselines to REP2, the one short-braced monument in our network, are correlated with temperature, with no lag time. Differences between REP2 and the other stations, which are deep-braced, should reflect processes occurring in the upper few meters of the ground. These correlations may be related to thermal expansion of these upper ground layers, and/or thermal expansion of the monuments themselves. Even over these short distances we see a systematic increase in RMS values with increasing baseline length. This, and the low RMS levels, suggests that site-specific effects are unlikely to be the limiting factor in the use of similar GPS sites for geophysical investigations