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NASA NTRS2022

Thermal Stress Weathering of Boulders on Airless Bodies

Rock boulders are considerably typical of airless rocky bodies throughout the inner solar system, so their environments prove useful to understanding the rates of surface-modification processes and “survival times” of these boulders. On the Moon, there are meter-sized boulders on the rims of small lunar carters of some known age, so modeling the rock destruction is applied. Interior and exterior stresses must be considered, including thermal day-night cycling of the regolith and sub-regolith, and solar wind.

Caitlin Ahrens↗

NASA NTRSDate not supplied

Comparison of the Bright Boulders on the Surface of the C-Type Asteroid Bennu with White Clasts in the Murchison CM Chondrite Breccia

Spectroscopic observations of asteroid Bennu suggest that the materials on the surface of the asteroid are most similar to aqueously-altered CM- or possibly CI-type carbonaceous chondrites [1], although a relationship with heated CM [2] or CR chondrites [1] is also possible. Recently, [3] detected unusually bright boulders (Fig. 1A) on the surface of Bennu. The band ratio indicates the presence of an absorption feature beyond 0.85μm and is consistent with the presence of mafic minerals such as pyroxene or olivine. The hyperspectral data suggest that the exogenic boulders have the same distinctive pyroxene composition as the howardite-eucrite-diogenite (HED) meteorites. However, similar mineralogical features were also observed in indigenous, thermally metamorphosed white clasts reported in samples of the Murchison CM2 (Fig. 2B; [4-5]) and is an alternative interpretation for the bright boulders observed on Bennu. In addition to detailed petrographic characteristics, we report here further chemistry, O, Cr, and Ti isotopes of the clasts in order to confirm their classification, and discuss their possible relationship to Bennu.

I. Kerraouch↗

DOE OSTI2012

Evaluation of Boulder, CO, SmartRegs Ordinance and Better Buildings Program

Under the SmartRegs ordinance in the city of Boulder, Colorado, all rental properties in the city must achieve an energy efficiency level comparable to a HERS Index of approximately 120 points or lower by the year 2019. The City of Boulder received a $12 million grant from the DOE’s Better Buildings initiative to create and incentivize their EnergySmart Program. In this report, the Consortium for Advanced Residential Buildings (CARB) describes its work with the program, including energy audits of rental properties, developing training programs for insulators and inspectors, and conducting interviews with property owners.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2018

Interdependencies and Risk to People and Critical Food, Energy, and Water Systems: 2013 Flood, Boulder, Colorado, USA

Abstract This paper examines the interdependencies mediating the cascading negative consequences triggered by the September 2013 flood, in Boulder, Colorado, USA. By illustrating the risks to people and critical food‐energy‐water systems of a low probability, high‐impact event, we draw lessons on what is likely to occur in the future. Other scholars have modeled the influence of interdependent infrastructures on cascading effects. But this is one of the first studies integrating stakeholders' understanding of the influence of interdependent actions, institutions, and infrastructures. These interdependencies create the conditions for vulnerability, which is a product of multiscale and dynamic sociodemographic, economic, technologic, environmental, and governance interactions. Political histories and historical decisions on where and how to design infrastructure exert a deep influence on short‐ and long‐term capacity to manage risk. Boulder's high socio‐institutional and learning capacity, while key, is not enough to influence integrative, transformative changes. Contrary to current approaches to nexus thinking, the regimes in which emergency and recovery actions are embedded are dynamically stable, thus imposing a logic for incremental change along established pathways of understanding and action. Our study offers some lessons on the challenges of bringing together diverse sectoral and jurisdictional sectors during and after an extreme event.

Romero‐Lankao, Patricia↗

DOE OSTI2014

Meeting report for the 1st skin microbiota workshop, Boulder, CO, October 15-16, 2012

This report details the outcome of the 1st Skin Microbiota Workshop, Boulder, CO, held on October 15th-16th 2012. The workshop was arranged to bring Department of Defense personnel together with experts in microbial ecology, human skin physiology and anatomy, and computational techniques for interrogating the microbiome to define research frontiers at the intersection of these important areas. The workshop outlined a series of questions and created several working groups to address those questions, specifically to promote interdisciplinary activity and potential future collaboration. The US Army provided generous grant support and the meeting was organized and hosted by the University of Colorado at Boulder. A primary forward vision of the meeting was the importance of understanding skin microbial communities to improve the health and stealth of US Army warfighters.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2025

AmeriFlux US-UR1 Boulder - UCRB

This is the AmeriFlux version of the carbon flux data for the site US-UR1 Boulder - UCRB. Site Description - This site is located in Boulder, Wyoming, in a high-altitude grassland ecosystem. The region experiences cold winters and mild summers, with relatively low precipitation throughout the year. Snowfall is common during the winter months, contributing to the seasonal water availability. The landscape is primarily covered by grass vegetation, with some areas supported by a center pivot irrigation system, which helps sustain plant growth in the dry environment.

Neale, C. U. [Daugherty Water for Food Global Inst↗

DOE OSTI2012

Evaluation of Boulder, CO, SmartRegs Ordinance and Better Buildings Program

Under the SmartRegs ordinance in the city of Boulder, Colorado, all rental properties in the city must achieve an energy efficiency level comparable to a HERS Index of approximately 120 points or lower by the year 2019. The City of Boulder received a $\$$12 million grant from the DOE's Better Buildings initiative to create and incentivize their EnergySmart Program. In this report, the Consortium forAdvanced Residential Buildings (CARB) describes its work with the program, including energy audits of rental properties, developing training programs for insulators and inspectors, and conducting interviews with property owners.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2013

Evaluation of a Multifamily Retrofit in Climate Zone 5, Boulder, Colorado (Fact Sheet)

In 2009, a 37-unit apartment complex located in Boulder, Colorado, underwent an energy retrofit to comply with Boulder SmartRegs Ordinance, a mandate that requires all rental properties to meet certain energy efficiency standards by 2018. The Consortium of Advanced Residential Buildings (CARB), a U.S. Department of Energy Building America team, worked with city planners and building owners to evaluate this program and recently completed a case study evaluating the effectiveness of a collection of retrofit measures.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2013

Predicted Versus Actual Savings for a Low-Rise Multifamily Retrofit in Boulder, Colorado

To determine the most cost-effective methods of improving buildings, accurate analysis and prediction of the energy use of existing buildings is essential. However, multiple studies confirm that analysis methods tend to over-predict energy use in poorly insulated, leaky homes and thus, the savings associated with improving those homes. In NREL's report titled 'Assessing and Improving the Accuracy of Energy Analysis of Residential Buildings,' researchers propose a method for improving the accuracy of residential energy analysis methods. A key step in this process involves the comparisons of predicted versus metered energy use and savings. In support of this research need, CARB evaluated the retrofit of a multifamily building in Boulder, CO. The updated property is a 37 unit, 2 story apartment complex built in 1950, which underwent renovations in early 2009 to bring it into compliance with Boulder, CO's SmartRegs ordinance. Goals of the study were to: 1) evaluate predicted versus actual savings due to the improvements, 2) identify areas where the modeling assumptions may need to be changed, and 3) determine common changes made by renters that would negatively impact energy savings. In this study, CARB seeks to improve the accuracy of modeling software while assessing retrofit measures to specifically determine which are most effective for large multifamily complexes in the cold climate region. Other issues that were investigated include the effects of improving building efficiency on tenant comfort, the impact on tenant turnover rates, and the potential market barriers for this type of community scale project.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2013

Predicted Versus Actual Savings for a Low-Rise Multifamily Retrofit in Boulder, Colorado

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

NASA NTRS1973

New evidence for interplanetary boulders?

The method of detection, the magnitude and the rate of occurrence of sudden disturbances in the motions of some short period comets are discussed. The disturbances have recently been suggested as potential indicators of collisions between the comets and interplanetary boulders - minor objects whose existence was predicted. The character of explosive phenomena, caused by an impact of such a boulder on a comet's nuclear surface, depends significantly on the surface texture of the target body. A method is suggested which supplies a good deal of the missing information about the structure and optical properties of nuclear surfaces from precise photometric observations of cometary nuclei at large solar distances.

Sekanina, Z.↗

NASA NTRS1974

Preliminary results of experiments to duplicate Boulder textures by thermal sintering of powders

Experiments seem to indicate that at the low pressures characteristic of an ejecta blanket, sintering or sintering/devitrification could have lithified boulder 1 matrix materials and produced the textural types observed in 72255 and 72275. This very preliminary conclusion is consistent with other observations that granitic clasts have undergone a slight degree of partial melting (and have therefore experienced temperatures on the order of 1000 C). It is concluded that maskelynite in the boulder is completely devitrified.

Hallam, M. E.↗

NASA NTRS1975

The Boulder

The external morphologies of Boulder 1, Station 2, and of the four samples taken from it by the Apollo 17 crew, are briefly described. The boulder is a polymict breccia, containing the following principal materials as clasts: gray competent breccias, black competent breccias, anorthositic breccias, pigeonite basalt, and coarse norite. All are enclosed in a matrix of light-colored friable breccia.

Marvin, U. B.↗

NASA NTRS1975

Major and trace element chemistry of Boulder 1 at Station 2, Apollo 17

Twenty-seven samples from Boulder 1 at Station 2 are analyzed for major and trace elements by atomic absorption spectrophotometry and neutron activation analysis. Two types of matrix and several types of clast materials are characterized on the basis of their chemistry. It is shown that one matrix type is a common material at the Apollo 17 site, while the other is probably exotic to that site. The most unusual clast materials found are coarse norite (an old rock no longer found in millimeter fragments at the site) and pigeonite basalt (possibly a highland volcanic rock). It is concluded that the boulder-forming process combined materials from at least two different localities or vertical strata.

Blanchard, D. P.↗

NASA NTRS1976

Texture and compositions of metal particles in Apollo 17, Station 6 boulder samples

Eighteen sections representing five matrix samples - 76015, 76215, 76275, 76295, and 76315 - from the Station 6 boulder were examined with emphasis on the textures and compositions of their native FeNi metal particles. It is found that many of the complex multiphase structures of the metal particles observed in the study cannot be explained by a continuous two-stage cooling of the impact-melt sheet. It is suggested that at least locally the boulder samples must have experienced multistage cooling and heating.

Misra, K. C.↗

NASA NTRS1976

Petrology and origin of Boulders no. 2 and no. 3, Apollo 17 Station 2

The paper presents petrographic and mineralogical data for five samples from Boulder 2 (72315, 72335, 72355, 72375, and 72395) and sample 72435 from Boulder 3 at Apollo 17 Station 2. All the samples were found to consist of a few percent megaclasts set in a fine-grained matrix, which is comprised of microclasts and a poikilitic to subophitic-textured groundmass that crystallized from a melt. The samples have similar modal mineralogies, mineral compositions, and bulk-chemical compositions.

Dymek, R. F.↗

NASA NTRS1977

Apollo 16 white boulder consortium samples 67455 and 67475 - Petrologic investigation

The paper describes Apollo 16 samples 67455 and 67475 from a white boulder which seems to be an ejecta block that represents a major lithology of the ejecta stratigraphic section penetrated by the North Ray cratering event. The characteristics of 67455, a polymict white feldspathic impact ejecta breccia, might possibly indicate that this and other samples from near the North Ray Crater rim come from a different source area or at least a different part of the same source area than do other Apollo 16 light matrix breccias. Sample 67475 is an impact melt probably produced by the same event that produced 67455. The transport of this assemblage and the relation of the white boulder to ejecta from the Nectaris event are considered.

Minkin, J. A.↗

NASA NTRS1975

Thermal regimes in impact melts and the petrology of the Apollo 17 Station 6 boulder

A progress report is presented on the petrologic study of the Station 6 boulder, taking into account the implications of its petrographic and geochemical studies to the understanding of the processes of formation and crystallization of impact melts. The interpretation of the data from the boulder suggests processes that appear reasonable for a petrogenetic model of impact events large enough to produce a layer of melt a kilometer or more wide and at most a few tens of meters thick. A summary of the model is presented. The primary difference between the new model and the previous models of Warner et al. (1973, 1974) and Simonds et al. (1973, 1974) is that melt and clasts are derived from distinctly different parts of the cratering regime. The cooling is modeled in two steps, first the rapid equilibration between clasts and matrix, and second, the much slower loss of heat to the surroundings.

Simonds, C. H.↗