An assessment of the micrometeoritic component in the Martian soil

Particles in the mass range from 10 to the minus 7th power to 10 to the minus 3rd power grams contribute 80 percent of the total mass influx of meteoritic material in the 10 to the minus 13th power to 10 to the 6th power gram mass range at Earth (Hughes, 1978). On Earth atmospheric entry, all but the smallest particles in the 10 to the minus 7th power to 10 to the minus 3rd power gram mass range, about 60 to 1200 micrometers in diameter, are heated sufficiently to melt and vaporize. Mars, because of its lower escape velocity and larger atmospheric scale height, is a much more favorable site for unmelted survival of micrometeorites on atmospheric deceleration. Researchers calculate that a significant fraction of particles throughout the 60 to 1200 micrometer diameter range will survive atmospheric entry unmelted. Thus returned Mars soils may offer a resource for sampling micrometeorites in a size range uncollectable in unaltered form at Earth. The addition of meteoritic material to the Mars soils should perturb their chemical composition, as has been detected using the soils on the Moon (Anders, et al., 1973). Using measured mass influx at Earth and estimates of the Mars/Earth flux ratio, researchers estimate a mass influx at Mars of between 2,700 and 202,000 metric tons per year

Atmospheric entry heating of cosmic dust

A computer simulation of the atmospheric entry deceleration and heating for micrometeorites into a planetary atmosphere was developed. The results of this model were compared to an earlier model. The major difference between the extent of heating experienced in the two models results from an underestimation of the atmospheric density at altitudes above 130 km in the earlier model. Thus the earlier model systematically overestimates the peak temperature reached on atmospheric entry. The discrepancies are small for near vertical entry and/or high density particles, where little deceleration is experienced at high altitudes. For particles entering at grazing incidence and/or of low density the discrepancies are more pronounced. Gravitational enhancement, which is a function of geocentric velocity at the collection opportunity, was found to bias near Earth cosmic dust collections in favor of low velocity particles. The effect is to increase the proportion of low velocity dust, predominately from asteroids, in the stratospheric cosmic dust collections and on Earth orbiting spacecraft impact surfaces over its proportion in the interplanetary dust cloud

The decline and end of the lead mining industry in the northern Pennines 1865 - 1914: a socio-economic comparison between Wensleydale, Swaledale and Teesdale

In 1865, the United Kingdom began importing more lead metal than it exported and by 1885 the domestic lead mining industry had halved. This industry had been in the vanguard of the Industrial Revolution but was also at the forefront of industrial decline. Lead was cheaper as a foreign import, with the supply easily outstripped the rising demand, forcing the price of lead to fall and contributing to the fall of the industry. This thesis examines and contrasts the contributing factors that caused the decline and end of the industry in the three valleys and the effects this had on the local community. The lead mines in Wensleydale and Swaledale had already exhausted the lead deposits. The mines in Wensleydale closed down but Swaledale was under the control of a local landowner and mining company entrepreneur, Sir George Denys, who wasted money on ventures. Lead mining dominated Swaledale and the fall of the industry decimated the valley causing a large drop in population. Wensleydale had an agricultural economic base, with smaller industries providing employment, so the end of the mining industry had less effect. Teesdale was also dominated by lead mining. The main employer was the London (Quaker) Lead Company. There were still mineral resources to be exploited and the company made efforts to improve efficiency before finally being liquidated in 1905. The company invested in mining and improvements, trained its staff, provided career opportunities and had a social policy for the well being of the community, all contrasting strongly with Swaledale. In 1865, there was no alternative employment to lead mining but, when the company folded, other minerals were being extracted, quarrying and the building of reservoirs provided other sources of employment in the locality, so there was less effect than in Swaledale

Trace Element Abundance Measurements on Cosmic Dust Particles

The X-Ray Microprobe on beamline X-26A at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was used to determine the abundances of elements from Cr through Sr in individual interplanetary dust particles (IDPs) collected from the Earth's stratosphere and the Scanning Transmission X-ray Microscope (STXM) on beamline X-1A at the NSLS was used to determine the carbon abundances and spatial distributions in IDPs. In addition, modeling was performed in an attempt to associate particular types of IDPs with specific types of parent bodies, and thus to infer the chemistry, mineralogy, and structural properties of those parent bodies

Theoretical molecular studies of astrophysical interest

When work under this grant began in 1974 there was a great need for state-to-state collisional excitation rates for interstellar molecules observed by radio astronomers. These were required to interpret observed line intensities in terms of local temperatures and densities, but, owing to lack of experimental or theoretical values, estimates then being used for this purpose ranged over several orders of magnitude. A problem of particular interest was collisional excitation of formaldehyde; Townes and Cheung had suggested that the relative size of different state-to-state rates (propensity rules) was responsible for the anomalous absorption observed for this species. We believed that numerical molecular scattering techniques (in particular the close coupling or coupled channel method) could be used to obtain accurate results, and that these would be computationally feasible since only a few molecular rotational levels are populated at the low temperatures thought to prevail in the observed regions. Such calculations also require detailed knowledge of the intermolecular forces, but we thought that those could also be obtained with sufficient accuracy by theoretical (quantum chemical) techniques. Others, notably Roy Gordon at Harvard, had made progress in solving the molecular scattering equations, generally using semi-empirical intermolecular potentials. Work done under this grant generalized Gordon's scattering code, and introduced the use of theoretical interaction potentials obtained by solving the molecular Schroedinger equation. Earlier work had considered only the excitation of a diatomic molecule by collisions with an atom, and we extended the formalism to include excitation of more general molecular rotors (e.g., H2CO, NH2, and H2O) and also collisions of two rotors (e.g., H2-H2)

Calculation of molecular excitation rates

State-to-state collisional excitation rates for interstellar molecules observed by radio astronomers continue to be required to interpret observed line intensities in terms of local temperatures and densities. A problem of particular interest is collisional excitation of water which is important for modeling the observed interstellar masers. In earlier work supported by a different NASA Grant, excitation of water in collisions with He atoms was studied; after many years of successively more refined calculations that problem now seems to be well understood, and discrepancies with earlier experimental data for related (pressure broadening) phenomena are believed to reflect experimental errors. Because of interstellar abundances, excitation by H2, the dominant interstellar species, is much more important than excitation by He, although it has been argued that rates for excitation by these are similar. Under the current grant theoretical study of this problem has begun which is greatly complicated by the additional degrees of freedom which must be included both in determining the interaction potential and also in the molecular scattering calculation. We have now computed the interaction forces for nearly a thousand molecular geometries and are close to having an acceptable global fit to these points which is necessary for the molecular dynamics calculations. Also, extensive modifications have been made to the molecular scattering code, MOLSCAT. These included coding the rotational basis sets and coupling matrix elements required for collisions of an asymmetric top with a linear rotor. A new method for numerical solution of the coupled equations has been incorporated. Because of the long-ranged nature of the water-hydrogen interaction it is necessary to integrate the equations to rather large intermolecular separations, and the integration methods previously available in MOLSCAT are not ideal for such cases. However, the method used by Alexander in his HIBRIDON code is particularly suited for such cases. We have obtained this code and incorporated that part which solves the coupled differential equations as an option in the MOLSCAT program

Knock! Knock! Who Is There? Investigating Data Leakage from a Medical Internet of Things Hijacking Attack

The amalgamation of Medical Internet of Things (MIoT) devices into everyday life is influencing the landscape of modern medicine. The implementation of these devices potentially alleviates the pressures and physical demands of healthcare systems through the remote monitoring of patients. However, there are concerns that the emergence of MIoT ecosystems is introducing an assortment of security and privacy challenges. While previous research has shown that multiple vulnerabilities exist within MIoT devices, minimal research investigates potential data leakage from MIoT devices through hijacking attacks. The research contribution of this paper is twofold. First, it provides a proof of concept that certain MIoT devices and their accompanying smartphone applications are vulnerable to hijacking attacks. Second, it highlights the effectiveness of using digital forensics tools as a lens to identify patient and medical device information on a hijacker’s smartphone