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393 results on '"Mcafee, J."'

1. First Evidence of Axial Shape Asymmetry and Configuration Coexistence in $^{74}$Zn: Suggestion for a Northern Extension of the $N=40$ Island of Inversion

Author

Rocchini, M., Garrett, P. E., Zielinska, M., Lenzi, S. M., Dao, D. D., Nowacki, F., Bildstein, V., MacLean, A. D., Olaizola, B., Ahmed, Z. T., Andreoiu, C., Babu, A., Ball, G. C., Bhattacharjee, S. S., Bidaman, H., Cheng, C., Coleman, R., Dillmann, I., Garnsworthy, A. B., Gillespie, S., Griffin, C. J., Grinyer, G. F., Hackman, G., Hanley, M., Illana, A., Jones, S., Laffoley, A. T., Leach, K. G., Lubna, R. S., McAfee, J., Natzke, C., Pannu, S., Paxman, C., Porzio, C., Radich, A. J., Rajabali, M. M., Sarazin, F., Schwarz, K., Shadrick, S., Sharma, S., Suh, J., Svensson, C. E., Yates, D., and Zidar, T.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

The excited states of $N=44$ $^{74}$Zn were investigated via $\gamma$-ray spectroscopy following $^{74}$Cu $\beta$ decay. By exploiting $\gamma$-$\gamma$ angular correlation analysis, the $2_2^+$, $3_1^+$, $0_2^+$ and $2_3^+$ states in $^{74}$Zn were firmly established. The $\gamma$-ray branching and $E2/M1$ mixing ratios for transitions de-exciting the $2_2^+$, $3_1^+$ and $2_3^+$ states were measured, allowing for the extraction of relative $B(E2)$ values. In particular, the $2_3^+ \to 0_2^+$ and $2_3^+ \to 4_1^+$ transitions were observed for the first time. The results show excellent agreement with new microscopic large-scale shell-model calculations, and are discussed in terms of underlying shapes, as well as the role of neutron excitations across the $N=40$ gap. Enhanced axial shape asymmetry (triaxiality) is suggested to characterize $^{74}$Zn in its ground state. Furthermore, an excited $K=0$ band with a significantly larger softness in its shape is identified. A shore of the $N=40$ ``island of inversion'' appears to manifest above $Z=26$, previously thought as its northern limit in the chart of the nuclides.

Published
2023
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2. First Evidence of Axial Shape Asymmetry and Configuration Coexistence in Zn74: Suggestion for a Northern Extension of the N=40 Island of Inversion

Author

Rocchini, M, Garrett, PE, Zielińska, M, Lenzi, SM, Dao, DD, Nowacki, F, Bildstein, V, MacLean, AD, Olaizola, B, Ahmed, ZT, Andreoiu, C, Babu, A, Ball, GC, Bhattacharjee, SS, Bidaman, H, Cheng, C, Coleman, R, Dillmann, I, Garnsworthy, AB, Gillespie, S, Griffin, CJ, Grinyer, GF, Hackman, G, Hanley, M, Illana, A, Jones, S, Laffoley, AT, Leach, KG, Lubna, RS, McAfee, J, Natzke, C, Pannu, S, Paxman, C, Porzio, C, Radich, AJ, Rajabali, MM, Sarazin, F, Schwarz, K, Shadrick, S, Sharma, S, Suh, J, Svensson, CE, Yates, D, and Zidar, T

Subjects
Nuclear and Plasma Physics, Synchrotrons and Accelerators, Physical Sciences, Mathematical Sciences, Engineering, General Physics, Mathematical sciences, Physical sciences
Abstract

The excited states of N=44 ^{74}Zn were investigated via γ-ray spectroscopy following ^{74}Cu β decay. By exploiting γ-γ angular correlation analysis, the 2_{2}^{+}, 3_{1}^{+}, 0_{2}^{+}, and 2_{3}^{+} states in ^{74}Zn were firmly established. The γ-ray branching and E2/M1 mixing ratios for transitions deexciting the 2_{2}^{+}, 3_{1}^{+}, and 2_{3}^{+} states were measured, allowing for the extraction of relative B(E2) values. In particular, the 2_{3}^{+}→0_{2}^{+} and 2_{3}^{+}→4_{1}^{+} transitions were observed for the first time. The results show excellent agreement with new microscopic large-scale shell-model calculations, and are discussed in terms of underlying shapes, as well as the role of neutron excitations across the N=40 gap. Enhanced axial shape asymmetry (triaxiality) is suggested to characterize ^{74}Zn in its ground state. Furthermore, an excited K=0 band with a significantly larger softness in its shape is identified. A shore of the N=40 "island of inversion" appears to manifest above Z=26, previously thought as its northern limit in the chart of the nuclides.

Published
2023

4. High-Precision Branching Ratio Measurement and Spin Assignment Implications for $^{62}$Ga Superallowed $\beta$ Decay

Author

MacLean, A. D., Laffoley, A. T., Svensson, C. E., Ball, G. C., Leslie, J. R., Andreoiu, C., Babu, A., Bhattacharjee, S. S., Bidaman, H., Bildstein, V., Burbadge, C., Bowry, M., Cheng, C., Cross, D. S., Diaz-Varela, A., Dillmann, I., Dunlop, M. R., Dunlop, R., Evitts, L. J., Finlay, P., Gillespie, S., Garnsworthy, A. B., Garrett, P. E., Gopaul, E., Griffin, C. J., Grinyer, G. F., Hackman, G., Henderson, J., Jigmeddorj, B., Leach, K. G., Kassanda, E., McAfee, J., Moukaddam, M., Natzke, C., Nittala, S., Olaizola, B., Park, J., Paxman, C., Pore, J. L., Porzio, C., Radich, A. J., Ruotsalainen, P., Saito, Y., Sharma, S., Smallcombe, J., Smith, J. K., Sultana, R., Turko, J., Williams, J., Yates, D., and Zidar, T.

Subjects
Nuclear Experiment
Abstract

A high-precision branching ratio measurement for the superallowed Fermi $\beta^{+}$ emitter $^{62}$Ga was performed with the Gamma-Ray Infrastructure for Fundamental Investigations of Nuclei (GRIFFIN) spectrometer at the Isotope Separator and Accelerator (ISAC) radioactive ion beam facility at TRIUMF. The high efficiency of the GRIFFIN spectrometer allowed 63 $\gamma$-ray transitions, with intensities down to $\approx$1 part per million (ppm) per $^{62}$Ga $\beta^{+}$ decay, to be placed in the level scheme of the daughter nucleus $^{62}$Zn, establishing the superallowed $\beta$ branching ratio for $^{62}$Ga decay to be 99.8577$^{+0.0023}_{-0.0029}\%$, a factor of 4 more precise than the previous world average. For several cascades, $\gamma-\gamma$ angular correlation measurements were performed to assign spins and/or determine the mixing ratios of transitions. In particular, the spin of the 2.342 MeV excited state in the daughter nucleus $^{62}$Zn was definitively assigned as $J = 0$. This assignment resolves a discrepancy between previous measurements and has important implications for the isospin symmetry breaking correction, $\delta_{C1}$, in $^{62}$Ga superallowed Fermi $\beta$ decay., Comment: A text label in Figure 12 has been corrected compared to the original submission

Published
2020
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6. First Evidence of Axial Shape Asymmetry and Configuration Coexistence in Zn74: Suggestion for a Northern Extension of the N=40 Island of Inversion

Author

Rocchini, M., Garrett, P. E., Zielińska, M., Lenzi, S. M., Dao, D. D., Nowacki, F., Bildstein, V., Maclean, A. D., Olaizola, B., Ahmed, Z. T., Andreoiu, C., Babu, A., Ball, G. C., Bhattacharjee, S. S., Bidaman, H., Cheng, C., Coleman, R., Dillmann, I., Garnsworthy, A. B., Gillespie, S., Griffin, C. J., Grinyer, G. F., Hackman, G., Hanley, M., Illana, A., Jones, S., Laffoley, A. T., Leach, K. G., Lubna, R. S., Mcafee, J., Natzke, C., Pannu, S., Paxman, C., Porzio, C., Radich, A. J., Rajabali, M. M., Sarazin, F., Schwarz, K., Shadrick, S., Sharma, S., Suh, J., Svensson, C. E., Yates, D., and Zidar, T.

Published
2023

11. High-precision branching ratio measurement and spin assignment implications for Ga-62 superallowed beta decay

Author

MacLean, AD, Laffoley, AT, Svensson, CE, Ball, GC, Leslie, JR, Andreoiu, C, Babu, A, Bhattacharjee, SS, Bidaman, H, Bildstein, V, Burbadge, C, Bowry, M, Cheng, C, Cross, DS, Diaz-Varela, A, Dillmann, I, Dunlop, MR, Dunlop, R, Evitts, LJ, Finlay, DP, Gillespie, S, Garnsworthy, AB, Garrett, PE, Gopaul, E, Griffin, CJ, Grinyer, GF, Hackman, G, Henderson, J, Jigmeddorj, FB, Leach, KG, Kassanda, E, McAfee, J, Moukaddam, M, Natzke, C, Nittala, S, Olaizola, B, Park, J, Paxman, C, Pore, JL, Porzio, C, Radich, AJ, Ruotsalainen, P, Saito, KY, Sharma, S, Smallcombe, J, Smith, JK, Sultana, R, Turko, J, Williams, J, Yates, D, and Zidar, T

Published
2020

13. High-precision branching ratio measurement and spin assignment implications for Ga62 superallowed β decay

Author

MacLean, A. D., primary, Laffoley, A. T., additional, Svensson, C. E., additional, Ball, G. C., additional, Leslie, J. R., additional, Andreoiu, C., additional, Babu, A., additional, Bhattacharjee, S. S., additional, Bidaman, H., additional, Bildstein, V., additional, Burbadge, C., additional, Bowry, M., additional, Cheng, C., additional, Cross, D. S., additional, Diaz-Varela, A., additional, Dillmann, I., additional, Dunlop, M. R., additional, Dunlop, R., additional, Evitts, L. J., additional, Finlay, P., additional, Gillespie, S., additional, Garnsworthy, A. B., additional, Garrett, P. E., additional, Gopaul, E., additional, Griffin, C. J., additional, Grinyer, G. F., additional, Hackman, G., additional, Henderson, J., additional, Jigmeddorj, B., additional, Leach, K. G., additional, Kassanda, E., additional, McAfee, J., additional, Moukaddam, M., additional, Natzke, C., additional, Nittala, S., additional, Olaizola, B., additional, Park, J., additional, Paxman, C., additional, Pore, J. L., additional, Porzio, C., additional, Radich, A. J., additional, Ruotsalainen, P., additional, Saito, Y., additional, Sharma, S., additional, Smallcombe, J., additional, Smith, J. K., additional, Sultana, R., additional, Turko, J., additional, Williams, J., additional, Yates, D., additional, and Zidar, T., additional

Published
2020
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16. Surface Composition of Mars: Results from a New Atmospheric Compensation Technique Applied to TES

Author

Kirkland, L. E, Herr, K. C, Ward, J, Keim, E. R, Hackwell, J. H, and McAfee, J. M

Subjects
Lunar And Planetary Science And Exploration
Abstract

Before TES (Thermal Emission Spectrometry) spectra can be used to model surface compositions, they must have a strong atmospheric compensation applied. We explore a very different atmospheric retrieval process, and compare results and implications for the derived surface composition. Additional information is contained in the original extended abstract.

Published
2002

20. CREATING HIGH-DENSITY LARGE SQUARE BALES BY RECOMPRESSION.

Author

McAfee, J. R., Shinners, K. J., Friede, J. F., and Walters, C. P.

Subjects
*ENERGY crops, *DENSITY
Abstract

Creating high-density biomass bales would reduce the number of bales handled, stored, and transported to biorefineries, thereby reducing costs. Recompression of large square bales is one approach to increase bale density; however, recompression research on large bales is limited. Recompression of common biomass crops in 80 cm × 90 cm nominal cross-section bales was used to quantify pressure-density and stress relaxation relationships as well as restraining forces required to maintain compressed densities. Linear, power, and exponential models were fit to the pressure-density data, with the linear model providing the best representation of the recompression process. When bales were recompressed soon after bale formation, density increased by an average of 134%, and the target dry-basis density of 205 kg m-3 was exceeded at the end of recompression with all crops. While still compressed, bales were wrapped with four steel cables configured with load cells to measure the restraining force after release of pressure followed by bale re-expansion. Total restraining forces ranged from 18 to 40 kN. Bale density decreased by an average of 17% due to re-expansion after pressure was released. Strain relief induced by allowing the bale to re-expand by approximately 10% before placing the cables around the bales reduced the required restraining force by an average of 35%. Although the forces applied were great (>560 kN), the dry-basis specific energy requirements were comparatively low (0.18 to 0.29 kWh Mg-1) because recompression took place over a relatively long duration of approximately 20 to 25 s. Recompressing large square bales is a low-energy method to achieve bale densities that should ensure weight-limited biomass transport. [ABSTRACT FROM AUTHOR]

Published
2019
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25. Contributors

Author

Adelman, Julie P., Albergotti, William G., Alleyne, Brendan, Alper, Cuneyt M., Anne, Samantha, Antonio, Stephanie Moody, Arriaga, Moises A., Aydin, Canset, Azadarmaki, Roya, Azbell, Christopher, Barnes, Christie, Barry, Rachel, Bauer, Richard, III, Bikhazi, Nadim, Blair, Elizabeth A., Bluestone, Charles D., Bonilla, Arturo, Boyce, Brian J., Bruni, Margherita, Buchman, Craig A., Bumpous, Jeffrey, Butrymowicz, Anna M., Byrd, J. Kenneth, Carroll, Thomas L., Carrau, Ricardo L., Cass, Nathan, Cass, Stephen P., Chai, Raymond, Chambers, Michael D., Chang, C.Y. Joseph, Chen, Douglas A., Chi, David H., Chiffer, Rebecca, Chin, Christopher J., Chiu, Robert J., Choby, Garret, Choi, Sukgi, Chou, Courtney T., Christie, Neil A., Christopoulos, Apostolos, Chung, William, Cognetti, David M., Cohen, Michael S., Colley, Patrick, Costantino, Peter D., Costello, Bernard J., Cunningham, Michael, DeAlmeida, John R., Dedhia, Kavita, Dedhia, Raj C., Dehdashti, Amir R., DeKlotz, Timothy, Deleyiannis, Frederic W.B., Derkay, Craig, Dhima, Matilda, Dohar, Joseph E., Dreifuss, Stephanie E., Duvvuri, Umamaheswar, Eibling, David E., Eu, Donovan, Fagan, Johan, Ferguson, Berrylin J., Ferris, Robert L., Filho, Pedro Andrade, Fraioli, Rebecca E., Fu, Roxana, Galati, Lisa, Gardner, Paul A., Garland, Catharine B., Gastman, Brian, Geltzeiler, Mathew, Gillman, Grant S., Godin, Morgan R., Goldberg, Andrew N., Goldman, Richard A., Goldstein, Jesse, Goyal, Amit, Granados, Emiro Caicedo, Hackman, Trevor, Hamilton, Steven, Hanna, Ehab, Hao, Sheng-Po, Hargreaves, Michele, Hathaway, Bridget C., Hatten, Kyle, Hetzler, Laura, Hildrew, Douglas M., Hirsch, Barry E., Hodnett, Benjamin L., Hosal, Sefik A., Hotaling, Jeffrey, Howard, Brittany, Huyett, Phillip, Inglis, Andrew F., Jr., Jabbour, Noel, Jackson, Neal M., Jang, David, Johnson, David M., Johnson, Jonas T., Kadakia, Sameep, Kass, Jason I., Keamy, Don, Jr., Kejner, Alexandra, Kent, David, Kim, Cherine H., Kim, Seungwon, Kitsko, Dennis J., Kost, Karen M., Krishna, Priya, Kundaria, Summit, Kwon, Daniel, Kwon, Tack-Kyun, Lango, Miriam N., Lee, Brian, Lee, Stella E., Lee, Steve, Leong, Paul, Lewis, Andrea, Light, Benjamin W., Lim, Chwee M., Lin, R. Jun, Liss, Jason A., Liu, Yuan F., Losee, Joseph, MacDonald, Charles B., MacIsaac, Zoe M., Man, Li-Xing, Mandell, David, Mandell-Brown, Mark, Manders, Ernest K., Maniakas, Anastasios, Manning, Scott, Maxwell, Jessica H., McAfee, J. Seth, McCall, Andrew A., McJunkin, Jonathan L., Mehta, Vikas, Mifsud, Matthew, Mims, Mark, Moskowitz, Howard S., Myers, Eugene N., Myers, Jeffrey N., Nance, Melonie, Nayak, Jayakar, Newman, Jason G., Nuss, Daniel W., O’Malley, Bert, Jr., Ordemann, Allison, Otto, Bradley A., Pant, Harshita, Park, Joshua S., Park, Renee E., Parnes, Steven, Parker, David W., II, Patel, Anju K., Patel, Chirag R., Petruzzelli, Guy, Piastro, Kristina, Pinheiro-Neto, Carlos D., Pitman, Karen, Pollack, Aron Z., Pou, Anna M., Prasad, Sanjay, Prevedello, Daniel M., Rassekh, Christopher H., Raz, Yael, Reeves, Travis, Reyes, Camilo, Richards, Nikisha Q., Rimell, Franklin L., Rivero, Alexander, Rodriguez, Kenneth D., Roehm, Pamela, Rosen, Clark A., Rowan, Nicholas R., Sahu, Nivedita, Sappington, Joshua M., Schaitkin, Barry M., Schell, Amy, Senchenkov, Alex, Shah, Gaurav A., Shohet, Jack A., Shtraks, Julie P., Siegel, Bianca, Silver, Natalie L., Simental, Alfred A., Jr., Simons, Jeffrey P., Smith, Libby J., Snyderman, Carl H., Solares, Arturo, Solari, Mario G., Song, John, Soose, Ryan, Sreenath, Satyan B., Stapleton, Amanda L., Stefko, Tonya, Steitz, Jeffrey, Tassler, Andrew, Tennant, Paul A., Terella, Adam, Thamboo, Andrew, Thekdi, Apurva, Thorp, Brian D., Thottam, Prasad John, Toh, Elizabeth, Tsang, Raymond K., Tschetter, Amanda J., Tummala, Ramachandra P., Turner, Meghan T., Ungkanont, Kitirat, Urquhart, Andrew C., Vescan, Allan D., Vivas, Esther X., Vosler, Peter S., Walgama, Evan S., Walker, David D., Walsh, Jonathan, Walvekar, Rohan R., Wang, Eric W., Weber, Peter, Wei, William I., Whitaker, Mark, Wilson, Meghan N., Wine, Todd M., Wood, Joshua W., Yellon, Robert, Ying, Yu-Lan (Mary), Yoshikawa, Noriko, Young, Vyvy, Zanation, Adam M., Zdanski, Carlton J., Zimmer, Lee A., and Zitelli, John

Published
2018
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27. A major determinant of hnRNP C protein binding to RNA is a novel bZIP-like RNA binding domain

Author

McAfee, J G, Shahied-Milam, L, Soltaninassab, S R, and LeStourgeon, W M

Subjects
Leucine Zippers, Binding Sites, Base Sequence, Molecular Structure, Sequence Homology, Amino Acid, Protein Conformation, Heterogeneous-Nuclear Ribonucleoprotein Group C, Molecular Sequence Data, Heterogeneous-Nuclear Ribonucleoproteins, Recombinant Proteins, DNA-Binding Proteins, Basic-Leucine Zipper Transcription Factors, G-Box Binding Factors, Ribonucleoproteins, Mutagenesis, Humans, Nucleic Acid Conformation, RNA, Amino Acid Sequence, Research Article, HeLa Cells, Sequence Deletion, Transcription Factors
Abstract

The C protein tetramer of hnRNP complexes binds approximately 150-230 nt of RNA with high cooperativity (McAfee J et al., 1996, Biochemistry 35:1212-1222). Three contiguously bound tetramers fold 700-nt lengths of RNA into a 19S triangular intermediate that nucleates 40S hnRNP assembly in vitro (Huang M et al., 1994, Mol Cell Biol 14:518-533). Although it has been assumed that the consensus RNA recognition motif (RRM) of C protein (residues 8-87) is the primary determinant of RNA binding, we report here that a recombinant construct containing residues 1-115 has very low affinity for RNA at physiological ionic strength (100 mM NaCl). Moreover, we demonstrate that an N-terminal deletion construct lacking the consensus RRM but containing residues 140-290 binds RNA with an affinity sufficient to account for the total free energy change observed for the binding of intact protein. Like native C protein, the 140-290 construct is a tetramer in solution and binds RNA stoichiometrically in a salt-resistant manner in 100-300 mM NaCl. Residues 140-179 of the N-terminal truncated variant contain 11 basic and 2 acidic residues, whereas residues 180-207 specify a leucine zipper motif that directs dimer assembly. Elements within the 50-residue carboxy terminus of C protein are required for tetramer assembly. A basic region followed by a leucine zipper is identical to the domain organization of the basic-leucine zipper (bZIP) class of DNA binding proteins. Sequence homologies with other proteins containing RRMs and the bZIP motif suggest that residues 140-207 represent a conserved bZIP-like RNA binding motif (designated bZLM). The steric orientation of four high-affinity RNA binding sites about rigid leucine zipper domains may explain in part C protein's asymmetry, its large occluded site size, and its RNA folding activity.

Published
1996

31. Martian topography from the Mariner 6 and 7 infrared spectra

Author

Herr, K. C, Horn, D, Mcafee, J. M, and Pimentel, G. C

Subjects
Space Sciences
Abstract

Mars topography from Mariner 6 and 7 IR spectra, discussing geographical resolution, surface carbon dioxide pressure, depressions, ridges and valleys

Published
1970

32. Lateral flow in the exosphere.

Author

Mcafee, J. R

Subjects
Geophysics
Abstract

Hydrogen and helium lateral flow in collisionless exosphere calculated on model for various sinusoidal temperature and concentration variations over exobase surface

Published
1967
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33. The composition of the Martian atmosphere - Minor constituents.

Author

Horn, D, Mcafee, J. M, Winer, A. M, Herr, K. C, and Pimentel, G. C

Subjects
Space Sciences
Abstract

The Mariner 6 and 7 infrared spectrometers provided data which, in principle, determine upper limits on the possible atmospheric abundance of every gaseous substance that was undetected but which has recognized absorptions in the accessible spectral region, 1.9 to 14.4 microns. Through supporting laboratory determinations of curves of growth under pressure-broadening conditions appropriate to Mars, upper limits can be specified (expressed first in cm-atm, STP, for a vertical column and then in parts per million) for NO2, NH3, C3O2, SO2, OCS, NO, O3, CH4, N2O, HCL, HBr, and H2S. In addition, considerations of band contours, moments of inertia, and experimental absorption coefficients make it possible to place useful upper limits on 27 additional substances that were not detected and for which curves of growth have not been measured.

Published
1972
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35. VIOLENT COOKOFF REACTIONS IN HMX-BASED EXPLOSIVES IN DDT TUBES: TRACKING LUMINOUS WAVES WITH STREAK IMAGING.

Author

Parker, G. R., Dickson, P., Asay, B. W., Smilowitz, L. B., Henson, B. F., and McAfee, J. M.

Subjects
EXPLOSIVES, IMAGING systems, CHEMICAL reactions, CAMCORDERS, HIGH-speed photography, IMAGE databases
Abstract

Recent implementation of modern high-speed video cameras has permitted the experimental flexibility needed to revisit classic deflagration-to-detonation (DDT) tube experiments and capture novel and valuable results displaying the progression of luminous reaction from a cookoff event. The authors present select data from a series of experiments where the HMX-based high explosives PBX 9501 and LX-07 were heated above 180°C for various durations to impose damage (i.e. phase transitions and void generation) before being driven to cook off. These two explosives have different polymeric binders, HMX mass fractions and cookoff responses and a comparison between the two offers mechanistic insights on how thermal explosions evolve. From this series, results will be displayed indicating a wide range of violence from somewhat mild pressure bursts, to intermediate-power compressive burns, to high-violence DDT. Image data from high temperature DDT tube experiments, where the explosive was ignited on one end, were also collected and will be included for comparison. [ABSTRACT FROM AUTHOR]

Published
2012
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