Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “BLAST”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Transition of Blast Furnace Slag from Silicate Based to Aluminate Based: Electrical Conductivity

The electrical conductivity of the CaO-SiO{sub 2}-Al{sub 2}O{sub 3}-MgO-TiO{sub 2} slag was determined using the four-electrode method. The effect of the Al{sub 2}O{sub 3} and Al{sub 2}O{sub 3}/SiO{sub 2} mass ratio on the electrical conductivity was studied. At a fixed CaO/SiO{sub 2} ratio of 1.20, the electrical conductivity decreases with increasing Al{sub 2}O{sub 3} from 16 mass pct to 24 mass pct because of the increased polymerization of aluminosilicate structures and the reduced amount of conductive ions. However, it increases with Al{sub 2}O{sub 3} of more than 24 mass pct because of the difference in the stable energy between [AlO{sub 4}]{sup 5−} and [SiO{sub 4}]{sup 4−}. Increasing the Al{sub 2}O{sub 3}/SiO{sub 2} ratio from 0.47 to 0.79 causes the electrical conductivity to increase and has an opposite effect when the ratio is greater than 0.79. Furthermore, Raman spectroscopy of the quenched slags was analyzed to understand the structural role of Al{sub 2}O{sub 3} and Al{sub 2}O{sub 3}/SiO{sub 2} mass ratio in the network. The Raman spectroscopy results indirectly supported the variations of electrical conductivity with the composition of the slags.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Accelerated carbonation and structural transformation of blast furnace slag by mechanochemical alkali-activation

Alternative cements and production routes are necessary to offset the considerable global CO 2 emissions of Portland cement production. The combination of alkali-activation and mechanochemical milling in a CO 2 rich atmosphere is a promising green direction for synthesizing cementitious material as it upcycles hazardous material (slag) while capturing wt% of CO 2 during synthesis. We investigate the resulting structural transformations incurred during synthesis and hydration using a suite of characterization techniques including solid-state 27 Al, 29 Si, and 13 C NMR. The local aluminosilicate network structure of the processed clinker is best described by a melilite-type structure. Upon hydration, the network polymerizes to form a calcium, sodium aluminosilicate hydrate gel. The synthesis route also creates various metastable carbonates and bicarbonates from captured CO 2 and alkali-additives that transform into stable carbonate phases like calcite, aragonite, and gaylussite, after hydration. These findings indicate accelerated carbonation reactions occur during clinker production and demonstrates novelty as a green cement technology.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Nuclear thermal source transfer unit, post-blast soil sample drying system

Los Alamos National Laboratory states that its mission is “To solve national security challenges through scientific excellence.” The Science Undergraduate Laboratory Internship (SULI) programs exists to engage undergraduate students in STEM work by providing opportunity to work at DOE facilities. As an undergraduate mechanical engineering intern under the SULI program at Los Alamos during the fall semester of 2016, I had the opportunity to contribute to the mission of the Laboratory while developing skills in a STEM discipline. I worked with Technology Applications, an engineering group that supports non-proliferation, counter terrorism, and emergency response missions. This group specializes in tool design, weapons engineering, rapid prototyping, and mission training. I assisted with two major projects during my appointment Los Alamos. The first was a thermal source transportation unit, intended to safely contain a nuclear thermal source during transit. The second was a soil drying unit for use in nuclear postblast field sample collection. These projects have given me invaluable experience working alongside a team of professional engineers. Skills developed include modeling, simulation, group design, product and system design, and product testing.

42 ENGINEERING↗
DOE OSTI2023

(U) Blast Tube Rehabilitation (Final Design Review) [Slides]

Saddle design is being proposed to improve overall response of facility. No plasticity predicted in tube sections buying down risk of a catastrophic failure. Plasticity is predicted in the support for loadings representing 190# C4. The design has been iterated to decrease localized plasticity and buy down risk. It is recommended that no amount of explosive driver be placed in A36 sections. Previous work suggests yielding can develop in the tube section causing rupture. J2 colleagues have reviewed analysis results. Outstanding question of additional plastic strain is developing from subsequent uses.

42 ENGINEERING↗