A theoretical study of the propagation and attenuation of acoustic waves in the lunar surface Interim report

Acoustic wave propagation and attenuation in lunar space environmen

Application of the SRI cloud-tracking technique to rapid-scan GOES observations

An automatic cloud tracking system was applied to multilayer clouds associated with severe storms. The method was tested using rapid scan observations of Hurricane Eloise obtained by the GOES satellite on 22 September 1975. Cloud tracking was performed using clustering based either on visible or infrared data. The clusters were tracked using two different techniques. The data of 4 km and 8 km resolution of the automatic system yielded comparable in accuracy and coverage to those obtained by NASA analysts using the Atmospheric and Oceanographic Information Processing System

Electrically Conductive Paints for Satellites

A program was conducted to develop and test electrically conductive paint coatings for spacecraft. A wide variety of organic and inorganic coatings were formulated using conductive binders, conductive pigments, and similar approaches. Z-93, IITRI's standard specification inorganic thermal control coating, exhibits good electrical properties and is a very space-stable coating system. Several coatings based on a conductive pigment (antimony-doped tin oxide) in silicone and silicate binders offer considerable promise. Paint systems using commercially available conductive polymers also appear to be of interest, but will require substantial development. Evaluations were made based on electrical conductivity, paint physical properties, and the stability of spectral reflectance in space environment testing

Application of an automatic cloud tracking technique to Meteosat water vapor and infrared observations

The automatic cloud tracking system was applied to METEOSAT 6.7 micrometers water vapor measurements to learn whether the system can track the motions of water vapor patterns. Data for the midlatitudes, subtropics, and tropics were selected from a sequence of METEOSAT pictures for 25 April 1978. Trackable features in the water vapor patterns were identified using a clustering technique and the features were tracked by two different methods. In flat (low contrast) water vapor fields, the automatic motion computations were not reliable, but in areas where the water vapor fields contained small scale structure (such as in the vicinity of active weather phenomena) the computations were successful. Cloud motions were computed using METEOSAT infrared observations (including tropical convective systems and midlatitude jet stream cirrus)

Coupling between static friction force and torque for a tripod

If a body is resting on a flat surface, the maximal static friction force before motion sets in is reduced if an external torque is also applied. The coupling between the static friction force and static friction torque is nontrivial as our studies for a tripod lying on horizontal flat surface show. In this article we report on a series of experiments we performed on a tripod and compare these with analytical and numerical solutions. It turns out that the coupling between force and torque reveals information about the microscopic properties at the onset to sliding.Comment: 7 pages, 4 figures, revte

Time-Averaged Adiabatic Potentials: Versatile traps and waveguides for ultracold quantum gases

We demonstrate a novel class of trapping potentials, time-averaged adiabatic potentials (TAAP) which allows the generation of a large variety of traps and waveguides for ultracold atoms. Multiple traps can be coupled through controllable tunneling barriers or merged altogether. We present analytical expressions for pancake-, cigar-, and ring- shaped traps. The ring-geometry is of particular interest for guided matter-wave interferometry as it provides a perfectly smooth waveguide of controllable diameter, and thus a tunable sensitivity of the interferometer.Comment: 5 pages, 3 figure

Evaluation of Two Commercially Available Cannabidiol Formulations for Use in Electronic Cigarettes

Since 24 states and the District of Columbia have legalized marijuana in some form, suppliers of legal marijuana have developed Cannabis sativa products for use in electronic cigarettes (e-cigarettes). Personal battery powered vaporizers, or e-cigarettes, were developed to deliver a nicotine vapor such that smokers could simulate smoking tobacco without the inherent pathology of inhaled tobacco smoke. The liquid formulations used in these devices are comprised of an active ingredient such as nicotine mixed with vegetable glycerin (VG) and/or propylene glycol (PG) and flavorings. A significant active ingredient of C. sativa, cannabidiol (CBD), has been purported to have anti-convulsant, anti-nociceptive, and anti-psychotic properties. These properties have potential medical therapies such as intervention of addictive behaviors, treatments for epilepsy, management of pain for cancer patients, and treatments for schizophrenia. However, CBD extracted from C. sativa remains a DEA Schedule I drug since it has not been approved by the FDA for medical purposes. Two commercially available e-cigarette liquid formulations reported to contain 3.3 mg/mL of CBD as the active ingredient were evaluated. These products are not regulated by the FDA in manufacturing or in labeling of the products and were found to contain 6.5 and 7.6 mg/mL of CBD in VG and PG with a variety of flavoring agents. Presently, while labeled as to content, the quality control of manufacturers and the relative safety of these products is uncertain

Apollo 7 retrofire and reentry of service propulsion module. Further study of Intelsat 2 F-2 apogee burn

Photography of Apollo 7 retrofire and service propulsion module reentry and apogee burn of Intelsat 2 F-2 satellit

Grain boundary energies and cohesive strength as a function of geometry

Cohesive laws are stress-strain curves used in finite element calculations to describe the debonding of interfaces such as grain boundaries. It would be convenient to describe grain boundary cohesive laws as a function of the parameters needed to describe the grain boundary geometry; two parameters in 2D and 5 parameters in 3D. However, we find that the cohesive law is not a smooth function of these parameters. In fact, it is discontinuous at geometries for which the two grains have repeat distances that are rational with respect to one another. Using atomistic simulations, we extract grain boundary energies and cohesive laws of grain boundary fracture in 2D with a Lennard-Jones potential for all possible geometries which can be simulated within periodic boundary conditions with a maximum box size. We introduce a model where grain boundaries are represented as high symmetry boundaries decorated by extra dislocations. Using it, we develop a functional form for the symmetric grain boundary energies, which have cusps at all high symmetry angles. We also find the asymptotic form of the fracture toughness near the discontinuities at high symmetry grain boundaries using our dislocation decoration model.Comment: 12 pages, 19 figures, changed titl