LANDSAT D local user terminal study

The effect of the changes incorporated in the LANDSAT D system on the ability of a local user terminal to receive, record and process data in real time was studied. Alternate solutions to the problems raised by these changes were evaluated. A loading analysis was performed in order to determine the quantities of data that a local user terminal (LUT) would be interested in receiving and processing. The number of bits in an MSS and a TM scene were calculated along with the number of scenes per day that an LUT might require for processing. These then combined to a total number of processed bits/day for an LUT as a function of sensor and coverage circle radius

Use of remote sensing techniques for geological hazard surveys in vegetated urban regions

The feasibility of using aerial photography for lithologic differentiation in a heavily vegetated region is investigated using multispectral imagery obtained from LANDSAT satellite and aircraft-borne photography. Delineating and mapping of localized vegetal zones can be accomplished by the use of remote sensing because a difference in morphology and physiology results in different natural reflectances or signatures. An investigation was made to show that these local plant zones are affected by altitude, topography, weathering, and gullying; but are controlled by lithology. Therefore, maps outlining local plant zones were used as a basis for lithologic map construction

Electrostatics in wind-blown sand

Wind-blown sand, or "saltation," is an important geological process, and the primary source of atmospheric dust aerosols. Significant discrepancies exist between classical saltation theory and measurements. We show here that these discrepancies can be resolved by the inclusion of sand electrification in a physically based saltation model. Indeed, we find that electric forces enhance the concentration of saltating particles and cause them to travel closer to the surface, in agreement with measurements. Our results thus indicate that sand electrification plays an important role in saltation.Comment: 4 journal pages, 5 figures, and supplementary material. Article is in press at PR

Indonesian Throughflow as a preconditioning mechanism for submarine landslides in the Makassar Strait

This work was completed as part of a Scottish Funding Council (SFC) Global Challenges Research Fund (GCRF) pump-priming project at Heriot Watt University (PI Nicholson). We would like to thank our partners at Bandung Institute of Technology, and the members of the Indonesian Marine Geological Institute and Geological Survey of Indonesia for their discussion and contribution to this research. We thank TGS and Multiclient Geophysical for permission to publish seismic and multibeam data respectively. D.R. Tappin publishes with the permission of the Executive Director of the BGS (United Kingdom Research and Innovation).Peer reviewedPublisher PD

Delineation of geological problems for use in urban planning

Activities of the University of Alabama in support of state and local planning commissions are reported. Demonstrations were given of the various types of remotely sensed images available from U-2, Skylab, and LANDSAT; and their uses and limitations were discussed. Techniques to be used in determining flood prone areas were provided for environmental studies. A rapid, inexpensive method for study was developed by which imagery is copied on 35 mm film and projected on existing topographic maps for measuring delta volume and growth

Impact of Molecular Architecture and Adsorption Density on Adhesion of Mussel-Inspired Surface Primers with Catechol-Cation Synergy.

Marine mussels secrete proteins rich in residues containing catechols and cationic amines that displace hydration layers and adhere to charged surfaces under water via a cooperative binding effect known as catechol-cation synergy. Mussel-inspired adhesives containing paired catechol and cationic functionalities are a promising class of materials for biomedical applications, but few studies address the molecular adhesion mechanism(s) of these materials. To determine whether intramolecular adjacency of these functionalities is necessary for robust adhesion, a suite of siderophore analog surface primers was synthesized with systematic variations in intramolecular spacing between catechol and cationic functionalities. Adhesion measurements conducted with a surface forces apparatus (SFA) allow adhesive failure to be distinguished from cohesive failure and show that the failure mode depends critically on the siderophore analog adsorption density. The adhesion of these molecules to muscovite mica in an aqueous electrolyte solution demonstrates that direct intramolecular adjacency of catechol and cationic functionalities is not necessary for synergistic binding. However, we show that increasing the catechol-cation spacing by incorporating nonbinding domains results in decreased adhesion, which we attribute to a decrease in the density of catechol functionalities. A mechanism for catechol-cation synergy is proposed based on electrostatically driven adsorption and subsequent binding of catechol functionalities. This work should guide the design of new adhesives for binding to charged surfaces in saline environments

Can vaccination roll-out be more equitable if population risk is taken into account?

Background COVID-19 vaccination in many countries, including England, has been prioritised primarily by age. However, people of the same age can have very different health statuses. Frailty is a commonly used metric of health and has been found to be more strongly associated with mortality than age among COVID-19 inpatients. Methods We compared the number of first vaccine doses administered across the 135 NHS Clinical Commissioning Groups (CCGs) of England to both the over 50 population and the estimated frail population in each area. Area-based frailty estimates were generated using the English Longitudinal Survey of Ageing (ELSA), a national survey of older people. We also compared the number of doses to the number of people with other risk factors associated with COVID- 19: Atrial fibrillation, chronic kidney disease, diabetes, learning disabilities, obesity and smoking status. Results We estimate that after 79 days of the vaccine program, across all Clinical Commissioning Group areas, the number of people who received a first vaccine per frail person ranged from 4.4 (95% CI 4.0-4.8) and 20.1 (95% CI 18.3-21.9). The prevalences of other risk factors were also poorly associated with the prevalence of vaccination across England. Conclusions Vaccination with age-based priority created area-based inequities in the number of doses administered relative to the number of people who are frail or have other risk factors associated with COVID-19. As frailty has previously been found to be more strongly associated with mortality than age for COVID-19 inpatients, an age-based priority system may increase the risk of mortality in some areas during the vaccine roll-out period. Authorities planning COVID-19 vaccination programmes should consider the disadvantages of an age-based priority system

DATA REPORT

INTRODUCTION Ocean Drilling Program (ODP) Leg 116 cored the distal part of the Bengal Fan at three closely spaced sites (717-719). The recovered sediments consisted dominantly of turbidites that varied in thickness between a few centimeters and 2 m or more. A number of different facies have been identified in the sequence and are described by Stow et al. (this volume). Representative examples of these facies types were selected and sampled for grain-size analysis. The results of these analyses are tabulated in this data report. METHODS Sediment samples of approximately 2-g dry weight were placed in 50-cm 3 beakers and disaggregated in a solution of 10% Calgon. To assist in complete disaggregation of the sediment, an ultrasonic probe was used for approximately 2 min. on each sample. Suspended sample concentrations were of the order of 20 g/L. The prepared suspensions were stored in 150-cm 3 plastic bottles. The grain-size analyses were performed by laser diffraction using Malvern particle sizers, models 35OOD and 2600C. The principles of particle-size analysis by laser diffraction are described by The Malvern laser-sizers consist of a laser source, beam expander, sample chamber, focusing lens, ring detector, and a microcomputer. In this study each analysis used a 100-mm focal length focusing lens yielding data consisting of 15 size classes between 1.9 and 188 µm. A percentage of sample outside of this range above and below these limits is also given. The grain-size distribution was computed using the model-independent program option. The sample suspension is introduced into a small ultrasonic tank from which the suspension is continuously pumped through the sample chamber in the path of the laser. The main attraction of laser diffraction analysis for this study was the relatively small sample size required for analysis. Only 2-5 cm 3 of the prepared suspensions are required for each analysis. Several repeat analyses can therefore be performed even on very small original samples. An additional advantage is the speed with which analyses can be performed, generally about 10 min per sample. For many of the samples, duplicate or triplicate analyses were performed to test the reproducibility of the results. 1 Cochran, J. R., Stow, D.A.V., et al., 1990. Proc. ODP, Sci. Results, 116: College Station, TX (Ocean Drilling Program)

Drop Splashing on a Dry Smooth Surface

The corona splash due to the impact of a liquid drop on a smooth dry substrate is investigated with high speed photography. A striking phenomenon is observed: splashing can be completely suppressed by decreasing the pressure of the surrounding gas. The threshold pressure where a splash first occurs is measured as a function of the impact velocity and found to scale with the molecular weight of the gas and the viscosity of the liquid. Both experimental scaling relations support a model in which compressible effects in the gas are responsible for splashing in liquid solid impacts.Comment: 11 pages, 4 figure