Socialism versus communism: An ethical and psychological contrast

https://stars.library.ucf.edu/prism/1256/thumbnail.jp

ALS engine propellant effector system

This report summarizes analysis, design, and experimental testing done on the propellant effector (valve plus electromechanical actuator) for the Advanced Launch System (ALS) main engine

Portable propellant cutting assembly, and method of cutting propellant with assembly

A propellant cutting assembly and method of using the assembly to cut samples of solid propellant in a repeatable and consistent manner is disclosed. The cutting assembly utilizes two parallel extension beams which are shorter than the diameter of a central bore of an annular solid propellant grain and can be loaded into the central bore. The assembly is equipped with retaining heads at its respective ends and an adjustment mechanism to position and wedge the assembly within the central bore. One end of the assembly is equipped with a cutting blade apparatus which can be extended beyond the end of the extension beams to cut into the solid propellant

A New High-Resolution Map of World Mountains and an Online Tool for Visualizing and Comparing

Answers to the seemingly straightforward questions “what is a mountain?” and “where are the mountains of the world?” are in fact quite complex, and there have been few attempts to map the mountains of the earth in a consistent and rigorous fashion. However, knowing exactly where mountain ecosystems are distributed on the planet is a precursor to conserving them, as called for in Sustainable Development Goals 6 and 15 of the United Nations 2030 Agenda for Sustainable Development. In this article we first compare 3 characterizations of global mountain distributions, including a new, high-resolution (250 m) map of global mountains derived from terrain characteristics. We show how differences in conceptual definition, methodology, and spatial resolution of source data can result in differences in the extent and location of lands classed as mountains. For example, the new 250-m resource documents a larger global mountain extent than previous characterizations, although it excludes plateaus, hilly forelands, and other landforms that are often considered part of mountain areas. We then introduce the Global Mountain Explorer, a new web-based application specifically developed for exploration, visualization, and comparison of these maps. This new open-access tool is an intuitive and versatile resource suitable for a broad range of users and applications

A Global Assessment of Gold, Titanium, Strontium and Barium Pollution Using Sperm Whales (Physeter Macrocephalus) As an Indicator Species

This study provides a global baseline for barium, gold, titanium and strontium as marine pollutants using the sperm whale (Physeter macrocephalus) as an indicator species. Barium, gold, titanium and strontium are metals that are little studied in marine environments. However, their recent emergence as nanomaterials will likely increase their presence in the marine environment. Moreover, nanosized particles are likely to exhibit toxic outcomes not seen in macrosized particles. Biopsies from free ranging sperm whales were collected from around the globe. Total barium levels were measured in 275 of 298 sperm whales tested for barium and collected from 16 regions around the globe. The global mean for barium was 0.93 +/- 0.2ug/g with a detectable range from 0.1 to 27.9ug. Total strontium levels were measurable in all 298 sperm whales producing a global mean level of 2.2 +/- 0.1ug/g and a range from 0.2 to 11.5ug/g. Total titanium levels were also measured in all 298 sperm whales producing a global mean level of 4.5 +/- 0.25ug/g with a range from 0.1 to 29.8ug/g. Total gold levels were detected in 50 of the 194 sperm whales collected from 16 regions around the globe. Detectable levels ranged from 0.1 to 2.3ug/g tissue with a global mean level equal to 0.2 +/- 0.02ug/g. Previous reports of these metals were much lower than the mean levels reported here. The likely explanation is location differences and consistent with this explanation, we found statistically significant variation among regions. These data provide an important global baseline for barium, gold, titanium and strontium pollution and will allow for important comparisons to be made over time to assess the impact of nanomaterials on whales and the marine environment