How do we begin to connect to those who are no longer living, those who have been historically si... more How do we begin to connect to those who are no longer living, those who have been historically silenced, and those whose memory becomes a faint existence in our modern, colonial imaginary? Within Decolonial Feminist Research: Haunting, Rememory, and Mothers, Jeong-eun Rhee, a qualitative educational researcher, examines the tension that often accompanies the implementation of decolonial feminist knowledges, methodologies, and epistemologies, especially when these theoretical perspectives challenge the academic canon rooted in modernity and social scientific empirical realities. This review addresses Rhee’s major theoretical conceptualizations such as Rememory, M/others and Haunting throughout the various processes that often connect individuals through death and grieving. Rhee demonstrates that the production of knowledge being constructed through the rememory of those who have since passed, not only provides existence to their stories, but makes their lives, histories, and memories...
Objetivo: la investigación tuvo como objetivo determinar cómo la aplicación del Software Geogebra... more Objetivo: la investigación tuvo como objetivo determinar cómo la aplicación del Software Geogebra influye en el aprendizaje de los triángulos y sus medidas en los estudiantes del cuarto grado del nivel secundario
, an affirmative actionlequal opportunlty employer, is operated by the University of California f... more , an affirmative actionlequal opportunlty employer, is operated by the University of California for the U.S. Department of Energy under contract W-7405-ENG-36. By acceptance of this articlu, the publisher recognizes that the US. Government retains a nonexclusive, royaltyfree license to publish or reproduce the published form of this contribution, or to allow others to do so, for U.S. Government purposes. Los Alamos National Laboratory requests that the publisher identify this artlcle as work performed under the auspices of the US. Department of Energy. Los Alamos National Laboratory strongly supports academic freedom and a researcher's right to publish; as an institution, howover, the Laboratory does not endorse the viewpoint of a publication or guarantee its technical correctness.
The neutron-proton differential cross section has been measured at 63.1 MeV. The data span an ang... more The neutron-proton differential cross section has been measured at 63.1 MeV. The data span an angular range from 8, =40' to 165' with a relative precision of 3.0%. .A different angular behavior is observed in the present results as compared to that in the data between 55 and 65 MeV currently used in phase parameter analyses.
Radial thermal explosion experiments have been run using different HMX based formulations. The re... more Radial thermal explosion experiments have been run using different HMX based formulations. The reaction violence of the different HMX based formulations under identical boundary conditions varies dramatically. In this talk, PBX 9501 and PBX N9 deflagrations will be ...
We have completed a series of thermal explosion experiments on PBX 950 I and PBXN-9 and investiga... more We have completed a series of thermal explosion experiments on PBX 950 I and PBXN-9 and investigated their mechanism using proton radiography. In this paper we review the past five years of experiments utilizing radiographic techniques to study the mechanisms of intemal burning in thermal explosions in these HMX based formulations. Experimental details of trigger timing and synchronization are given. Radiographic images collected using both protons and x-rays are discussed. Comparisons of experiments with varying size, case confinement, binder, and synchronization are presented. Analytical techniques for quantifying the data in the images are presented and a mechanism for post-ignition bw-n propagation in a thermal explosion is discussed. From these experiments, we have observed a mechanism for sub-sonic deflagration that involves both gas phase convective and solid phase conductive bw-ning within the solid. The convective front velocity is directly measured trom the radiographic im...
Submitted for the SHOCK11 Meeting of The American Physical Society Radiography of the pre-ignitio... more Submitted for the SHOCK11 Meeting of The American Physical Society Radiography of the pre-ignition thermal decomposition of Energetic Materials LAURA SMILOWITZ, BRYAN HENSON, JERRY ROMERO, DAVID OSCHWALD, LANL-We have designed a small scale radiography experiment to image the density evolution of energetic materials during heating to ignition. The signal to noise of the system allows for sensitivity on the order of 1% change in density. We have used this apparatus to study the density evolution in several different HMX and RDX based formulations and can watch phase transitions and material flow. During the final seconds leading up to the ignition event, the loss of solid density can be observed. A summary of results to date will be presented.
We have made radiometric temperature measurements on a microsecond time scale during the compress... more We have made radiometric temperature measurements on a microsecond time scale during the compression and flow of PBX 9501 subsequent to impact. A cylindrical sample was fired into a sapphire window normal to the cylinder axis at velocities on the order of several hundred meters per second. Cylindrically symmetric flow resulted which led to the classic circular ignition pattern at the outermost radial distance from the center at times of a few to tens of microseconds and temperatures on the order of 800 degrees Celsius. We also observed a difference in ignition pattern for samples of beta or delta PBX 9501. We report the times and temperatures of ignition and relate them to our model of PBX 9501 decomposition kinetics. We also discuss these results in the context of various other methods of thermally and mechanically heating PBX 9501 and note the invariance of the decomposition kinetics of HMX to the method of heating.
We have made spatially and temporally resolved temperature measurements internal to a thermal exp... more We have made spatially and temporally resolved temperature measurements internal to a thermal explosion in PBX9501, which is a plastic bonded explosive composed of 95% HMX and 2.5% estane mixed with 2.5% nitroplasticizer (BDNPA/F). In order to study the evolution of ignition in a thermally treated piece of explosive, we have pushed the time resolution of several different temperature diagnostics.
The study of solid-solid phase transformations is hindered by the difficulty of finding a volumet... more The study of solid-solid phase transformations is hindered by the difficulty of finding a volumetric probe to use as a progress variable. Solids are typically optically opaque and heterogeneous. Over the past several years, second harmonic generation (SHG) has been used as a kinetic probe for a solid-solid phase transition in which the initial and final phases have different symmetries.
We have used a variety of observables to study the response of HMX based energetic m aterials fo ... more We have used a variety of observables to study the response of HMX based energetic m aterials fo rmulations to thermal stimuli. In this paper, we compare the response of PBX 9501 and PBX-9 to a temperature of 205°C. Both undergo thermal runaway at this boundary condition with similar preignition behavior. However, the post-ignition bum propagations of the two formulations are very di fferent with the final reaction violence significantly lower for PBX N-9 than for PBX 950 I.
How do we begin to connect to those who are no longer living, those who have been historically si... more How do we begin to connect to those who are no longer living, those who have been historically silenced, and those whose memory becomes a faint existence in our modern, colonial imaginary? Within Decolonial Feminist Research: Haunting, Rememory, and Mothers, Jeong-eun Rhee, a qualitative educational researcher, examines the tension that often accompanies the implementation of decolonial feminist knowledges, methodologies, and epistemologies, especially when these theoretical perspectives challenge the academic canon rooted in modernity and social scientific empirical realities. This review addresses Rhee’s major theoretical conceptualizations such as Rememory, M/others and Haunting throughout the various processes that often connect individuals through death and grieving. Rhee demonstrates that the production of knowledge being constructed through the rememory of those who have since passed, not only provides existence to their stories, but makes their lives, histories, and memories...
Objetivo: la investigación tuvo como objetivo determinar cómo la aplicación del Software Geogebra... more Objetivo: la investigación tuvo como objetivo determinar cómo la aplicación del Software Geogebra influye en el aprendizaje de los triángulos y sus medidas en los estudiantes del cuarto grado del nivel secundario
, an affirmative actionlequal opportunlty employer, is operated by the University of California f... more , an affirmative actionlequal opportunlty employer, is operated by the University of California for the U.S. Department of Energy under contract W-7405-ENG-36. By acceptance of this articlu, the publisher recognizes that the US. Government retains a nonexclusive, royaltyfree license to publish or reproduce the published form of this contribution, or to allow others to do so, for U.S. Government purposes. Los Alamos National Laboratory requests that the publisher identify this artlcle as work performed under the auspices of the US. Department of Energy. Los Alamos National Laboratory strongly supports academic freedom and a researcher's right to publish; as an institution, howover, the Laboratory does not endorse the viewpoint of a publication or guarantee its technical correctness.
The neutron-proton differential cross section has been measured at 63.1 MeV. The data span an ang... more The neutron-proton differential cross section has been measured at 63.1 MeV. The data span an angular range from 8, =40' to 165' with a relative precision of 3.0%. .A different angular behavior is observed in the present results as compared to that in the data between 55 and 65 MeV currently used in phase parameter analyses.
Radial thermal explosion experiments have been run using different HMX based formulations. The re... more Radial thermal explosion experiments have been run using different HMX based formulations. The reaction violence of the different HMX based formulations under identical boundary conditions varies dramatically. In this talk, PBX 9501 and PBX N9 deflagrations will be ...
We have completed a series of thermal explosion experiments on PBX 950 I and PBXN-9 and investiga... more We have completed a series of thermal explosion experiments on PBX 950 I and PBXN-9 and investigated their mechanism using proton radiography. In this paper we review the past five years of experiments utilizing radiographic techniques to study the mechanisms of intemal burning in thermal explosions in these HMX based formulations. Experimental details of trigger timing and synchronization are given. Radiographic images collected using both protons and x-rays are discussed. Comparisons of experiments with varying size, case confinement, binder, and synchronization are presented. Analytical techniques for quantifying the data in the images are presented and a mechanism for post-ignition bw-n propagation in a thermal explosion is discussed. From these experiments, we have observed a mechanism for sub-sonic deflagration that involves both gas phase convective and solid phase conductive bw-ning within the solid. The convective front velocity is directly measured trom the radiographic im...
Submitted for the SHOCK11 Meeting of The American Physical Society Radiography of the pre-ignitio... more Submitted for the SHOCK11 Meeting of The American Physical Society Radiography of the pre-ignition thermal decomposition of Energetic Materials LAURA SMILOWITZ, BRYAN HENSON, JERRY ROMERO, DAVID OSCHWALD, LANL-We have designed a small scale radiography experiment to image the density evolution of energetic materials during heating to ignition. The signal to noise of the system allows for sensitivity on the order of 1% change in density. We have used this apparatus to study the density evolution in several different HMX and RDX based formulations and can watch phase transitions and material flow. During the final seconds leading up to the ignition event, the loss of solid density can be observed. A summary of results to date will be presented.
We have made radiometric temperature measurements on a microsecond time scale during the compress... more We have made radiometric temperature measurements on a microsecond time scale during the compression and flow of PBX 9501 subsequent to impact. A cylindrical sample was fired into a sapphire window normal to the cylinder axis at velocities on the order of several hundred meters per second. Cylindrically symmetric flow resulted which led to the classic circular ignition pattern at the outermost radial distance from the center at times of a few to tens of microseconds and temperatures on the order of 800 degrees Celsius. We also observed a difference in ignition pattern for samples of beta or delta PBX 9501. We report the times and temperatures of ignition and relate them to our model of PBX 9501 decomposition kinetics. We also discuss these results in the context of various other methods of thermally and mechanically heating PBX 9501 and note the invariance of the decomposition kinetics of HMX to the method of heating.
We have made spatially and temporally resolved temperature measurements internal to a thermal exp... more We have made spatially and temporally resolved temperature measurements internal to a thermal explosion in PBX9501, which is a plastic bonded explosive composed of 95% HMX and 2.5% estane mixed with 2.5% nitroplasticizer (BDNPA/F). In order to study the evolution of ignition in a thermally treated piece of explosive, we have pushed the time resolution of several different temperature diagnostics.
The study of solid-solid phase transformations is hindered by the difficulty of finding a volumet... more The study of solid-solid phase transformations is hindered by the difficulty of finding a volumetric probe to use as a progress variable. Solids are typically optically opaque and heterogeneous. Over the past several years, second harmonic generation (SHG) has been used as a kinetic probe for a solid-solid phase transition in which the initial and final phases have different symmetries.
We have used a variety of observables to study the response of HMX based energetic m aterials fo ... more We have used a variety of observables to study the response of HMX based energetic m aterials fo rmulations to thermal stimuli. In this paper, we compare the response of PBX 9501 and PBX-9 to a temperature of 205°C. Both undergo thermal runaway at this boundary condition with similar preignition behavior. However, the post-ignition bum propagations of the two formulations are very di fferent with the final reaction violence significantly lower for PBX N-9 than for PBX 950 I.
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Papers by Jerry Romero