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In the late stages of stellar core-collapse, prior to core bounce, electron captures on medium-heavy nuclei drive deleptonization and simulations require the use of accurate reaction rates. Nuclei with neutron number near $N=50$, just above atomic number $Z=28$, play an important role, but rates used in astrophysical simulations rely primarily on a relatively simple single-state approximation. In order to improve the accuracy of astrophysical simulations, experimental data are needed to test the electron-capture rates and to guide the development of better theoretical models. This work presents the results of the $^{86}$Kr($t$,$^{3}$He+$\gamma$) experiment at the NSCL, from which an upper limit for the Gamow-Teller strength up to an excitation energy in $^{86}$Br of 5 MeV is extracted. The derived upper limit for the electron-capture rate on $^{86}$Kr indicates that the rate estimated through the single-state approximation is too high and that rates based on Gamow-Teller strengths estimated in shell-model and QRPA calculations are more accurate. The QRPA calculations tested in this manner were used for estimating the electron capture rates for 78 isotopes near $N=50$ and above $Z=28$. The impact of using these new electron-capture rates in simulations of supernovae instead of the rates based on the single-state approximation is investigated, indicating a significant reduction in the deleptonization that affects multi-messenger signals, such as the emission of neutrinos and gravitational waves., Comment: 15 pages, 10 figures

The Gamow-Teller strength distribution from ${}^{88}$Sr was extracted from a $(t,{}^{3}\text{He}+\gamma)$ experiment at 115 MeV/$u$ to constrain estimates for the electron-capture rates on nuclei around $N=50$, between and including $^{78}$Ni and $^{88}$Sr, which are important for the late evolution of core-collapse supernovae. The observed strength below an excitation energy of 8 MeV was consistent with zero and below 10 MeV amounted to $0.1\pm0.05$. Except for a very-weak transition that could come from the 2.231-MeV $1^{+}$ state, no $\gamma$ lines that could be associated with the decay of known $1^{+}$ states were identified. The derived electron-capture rate from the measured strength distribution is more than an order of magnitude smaller than rates based on the single-state approximation presently used in astrophysical simulations for most nuclei near $N=50$. Rates based on shell-model and quasiparticle random-phase approximation calculations that account for Pauli blocking and core-polarization effects provide better estimates than the single-state approximation, although a relatively strong transition to the first $1^{+}$ state in $^{88}$Rb is not observed in the data. Pauli unblocking effects due to high stellar temperatures could partially counter the low electron-capture rates. The new data serves as a zero-temperature benchmark for constraining models used to estimate such effects.

The $^{23}$Al($p,\gamma$)$^{24}$Si reaction is among the most important reactions driving the energy generation in Type-I X-ray bursts. However, the present reaction-rate uncertainty limits constraints on neutron star properties that can be achieved with burst model-observation comparisons. Here, we present a novel technique for constraining this important reaction by combining the GRETINA array with the neutron detector LENDA coupled to the S800 spectrograph at the National Superconducting Cyclotron Laboratory. The $^{23}$Al($d,n$) reaction was used to populate the astrophysically important states in $^{24}$Si. This enables a measurement in complete kinematics for extracting all relevant inputs necessary to calculate the reaction rate. For the first time, a predicted close-lying doublet of a 2$_2^+$ and (4$_1^+$,0$_2^+$) state in $^{24}$Si was disentangled, finally resolving conflicting results from two previous measurements. Moreover, it was possible to extract spectroscopic factors using GRETINA and LENDA simultaneously. This new technique may be used to constrain other important reaction rates for various astrophysical scenarios.

The $^{23}$Al($p,\gamma$)$^{24}$Si reaction is among the most important reactions driving the energy generation in Type-I X-ray bursts. However, the present reaction-rate uncertainty limits constraints on neutron star properties that can be achieved with burst model-observation comparisons. Here, we present a novel technique for constraining this important reaction by combining the GRETINA array with the neutron detector LENDA coupled to the S800 spectrograph at the National Superconducting Cyclotron Laboratory. The $^{23}$Al($d,n$) reaction was used to populate the astrophysically important states in $^{24}$Si. This enables a measurement in complete kinematics for extracting all relevant inputs necessary to calculate the reaction rate. For the first time, a predicted close-lying doublet of a 2$_2^+$ and (4$_1^+$,0$_2^+$) state in $^{24}$Si was disentangled, finally resolving conflicting results from two previous measurements. Moreover, it was possible to extract spectroscopic factors using GRETINA and LENDA simultaneously. This new technique may be used to constrain other important reaction rates for various astrophysical scenarios.

The Gamow-Teller strength distribution from ${}^{88}$Sr was extracted from a $(t,{}^{3}\text{He}+\gamma)$ experiment at 115 MeV/$u$ to constrain estimates for the electron-capture rates on nuclei around $N=50$, between and including $^{78}$Ni and $^{88}$Sr, which are important for the late evolution of core-collapse supernovae. The observed strength below an excitation energy of 8 MeV was consistent with zero and below 10 MeV amounted to $0.1\pm0.05$. Except for a very-weak transition that could come from the 2.231-MeV $1^{+}$ state, no $\gamma$ lines that could be associated with the decay of known $1^{+}$ states were identified. The derived electron-capture rate from the measured strength distribution is more than an order of magnitude smaller than rates based on the single-state approximation presently used in astrophysical simulations for most nuclei near $N=50$. Rates based on shell-model and quasiparticle random-phase approximation calculations that account for Pauli blocking and core-polarization effects provide better estimates than the single-state approximation, although a relatively strong transition to the first $1^{+}$ state in $^{88}$Rb is not observed in the data. Pauli unblocking effects due to high stellar temperatures could partially counter the low electron-capture rates. The new data serves as a zero-temperature benchmark for constraining models used to estimate such effects.

In the late stages of stellar core-collapse, prior to core bounce, electron captures on medium-heavy nuclei drive deleptonization and simulations require the use of accurate reaction rates. Nuclei with neutron number near $N=50$, just above atomic number $Z=28$, play an important role, but rates used in astrophysical simulations rely primarily on a relatively simple single-state approximation. In order to improve the accuracy of astrophysical simulations, experimental data are needed to test the electron-capture rates and to guide the development of better theoretical models. This work presents the results of the $^{86}$Kr($t$,$^{3}$He+$\gamma$) experiment at the NSCL, from which an upper limit for the Gamow-Teller strength up to an excitation energy in $^{86}$Br of 5 MeV is extracted. The derived upper limit for the electron-capture rate on $^{86}$Kr indicates that the rate estimated through the single-state approximation is too high and that rates based on Gamow-Teller strengths estimated in shell-model and QRPA calculations are more accurate. The QRPA calculations tested in this manner were used for estimating the electron capture rates for 78 isotopes near $N=50$ and above $Z=28$. The impact of using these new electron-capture rates in simulations of supernovae instead of the rates based on the single-state approximation is investigated, indicating a significant reduction in the deleptonization that affects multi-messenger signals, such as the emission of neutrinos and gravitational waves., Comment: 15 pages, 10 figures

Gamow-Teller (GT) strength distributions (B(GT)) in electron-capture (EC) daughters stemming from the parent ground state are computed with the shell-model in the full pf-shell space, with quasi-particle random-phase approximation (QRPA) in the formalism of Krumlinde and M\"oller and with an Approximate Method (AM) for assigning an effective B(GT). These are compared to data available from decay and charge-exchange (CE) experiments across titanium isotopes in the pf-shell from A=43 to A=62, the largest set available for any chain of isotopes in the pf-shell. The present study is the first to examine B(GT) and the associated EC rates across a particular chain of isotopes with the purpose of examining rate sensitivities as neutron number increases. EC rates are also computed for a wide variety of stellar electron densities and temperatures providing concise estimates of the relative size of rate sensitivities for particular astrophysical scenarios. This work underscores the astrophysical motivation for CE experiments in inverse kinematics for nuclei away from stability at the luminosities of future Radioactive Ion Beam Facilities., Comment: 12 pages, 9 figures, submitted to Physical Review C

Gamow-Teller (GT) strength distributions (B(GT)) in electron-capture (EC) daughters stemming from the parent ground state are computed with the shell-model in the full pf-shell space, with quasi-particle random-phase approximation (QRPA) in the formalism of Krumlinde and M\"oller and with an Approximate Method (AM) for assigning an effective B(GT). These are compared to data available from decay and charge-exchange (CE) experiments across titanium isotopes in the pf-shell from A=43 to A=62, the largest set available for any chain of isotopes in the pf-shell. The present study is the first to examine B(GT) and the associated EC rates across a particular chain of isotopes with the purpose of examining rate sensitivities as neutron number increases. EC rates are also computed for a wide variety of stellar electron densities and temperatures providing concise estimates of the relative size of rate sensitivities for particular astrophysical scenarios. This work underscores the astrophysical motivation for CE experiments in inverse kinematics for nuclei away from stability at the luminosities of future Radioactive Ion Beam Facilities., Comment: 12 pages, 9 figures, submitted to Physical Review C

Windows CE 3.0, also known as Pocket PC for palm-sized devices, is becoming increasingly popular among professionals and corporate enterprises. It is estimated that by 2004 Windows CE will have a share of 40% of the marketplace for palm-sized devices. The documented vulnerabilities against a major competitor of WinCE, Palm, and the proliferation of palm-sized devices highlight the need for security for these small-scale systems. This thesis is part of a larger project to enhance the security in WinCE. This thesis analyzed the threads and processes in WinCE, and discusses authentication, public key infrastructure (PKI) and future technologies as each relates to WinCE. The research discovered that Talisker, the next generation of WinCE, supports Kerberos an authentication protocol, and it also supports PKI (a key management system) components. Results of this thesis show that security can be enhanced in WinCE without requiring a change to its code base., http://archive.org/details/analyzingthreads109451794, US Marine Corps (USMC) author

Automated tracking of animal movement allows analyses that would not otherwise be possible by providing great quantities of data. The additional capability of tracking in realtime - with minimal latency - opens up the experimental possibility of manipulating sensory feedback, thus allowing detailed explorations of the neural basis for control of behavior. Here we describe a new system capable of tracking the position and body orientation of animals such as flies and birds. The system operates with less than 40 msec latency and can track multiple animals simultaneously. To achieve these results, a multi target tracking algorithm was developed based on the Extended Kalman Filter and the Nearest Neighbor Standard Filter data association algorithm. In one implementation, an eleven camera system is capable of tracking three flies simultaneously at 60 frames per second using a gigabit network of nine standard Intel Pentium 4 and Core 2 Duo computers. This manuscript presents the rationale and details of the algorithms employed and shows three implementations of the system. An experiment was performed using the tracking system to measure the effect of visual contrast on the flight speed of Drosophila melanogaster. At low contrasts, speed is more variable and faster on average than at high contrasts. Thus, the system is already a useful tool to study the neurobiology and behavior of freely flying animals. If combined with other techniques, such as `virtual reality'-type computer graphics or genetic manipulation, the tracking system would offer a powerful new way to investigate the biology of flying animals., Comment: pdfTeX using libpoppler 3.141592-1.40.3-2.2 (Web2C 7.5.6), 18 pages with 9 figures

Windows CE 3.0, also known as Pocket PC for palm-sized devices, is becoming increasingly popular among professionals and corporate enterprises. It is estimated that by 2004 Windows CE will have a share of 40% of the marketplace for palm-sized devices, The documented vulnerabilities against a major competitor of WinCE, Palm, and the proliferation of palm-sized devices highlight the need for security for these small- scale systems. This thesis is part of a larger project to enhance the security in WinCE. This thesis analyzed the threads and processes in WinCE, and discussed authentication, public key infrastructure (PKI) and future technologies as each relates to WinCE. The research discovered that Talisker, the next generation of WinCE, supports Kerberos an authentication protocol, and it also supports PKI (a key management system) components. Results of this thesis show that security can be enhanced in WinCE without requiring a change to its code base., The original document contains color images.

Windows CE 3.0, also known as Pocket PC for palm-sized devices, is becoming increasingly popular among professionals and corporate enterprises. It is estimated that by 2004 Windows CE will have a share of 40% of the marketplace for palm-sized devices. The documented vulnerabilities against a major competitor of WinCE, Palm, and the proliferation of palm-sized devices highlight the need for security for these small-scale systems. This thesis is part of a larger project to enhance the security in WinCE. This thesis analyzed the threads and processes in WinCE, and discusses authentication, public key infrastructure (PKI) and future technologies as each relates to WinCE. The research discovered that Talisker, the next generation of WinCE, supports Kerberos an authentication protocol, and it also supports PKI (a key management system) components. Results of this thesis show that security can be enhanced in WinCE without requiring a change to its code base.

This investigation was initiated to determine the insulating value of .040 inch 91-LD fibreglass bonded to a stainless steel sheet. The shear strengths of PR-1421 adhesive which was employed to bond the laminate to the steel became a critical factor in the study. Test coupons were prepared and subjected to high temperature flames directed against bare steel coupons and against the laminate protected samples. The ability of the laminate to remain intact and protect the steel skin was measured. The effect of the high temperatures upon the adhesive was also measured. The temperature rise was followed by thermocouples and recording millivoltmeters. It was found that the initial rate of rise of temperature of the bare steel was about ten times as fast as the steel protected with laminate. A large number of photographs, tables and graphs present the information visually. The shear strength of the adhesive was measured at the temperatures from ambient to that which were found to exist during the flame heating. (Author)

The Weather and Surface Radiation Prediction Unit commenced preliminary weather observations at the SHOAL Site in August 1962. Sufficient data was collected to insure statistical significance. Commencing on D-30, a complete weather analysis and forecasting unit was in operation at the SHOAL site. The weather facilities, observation schedules, detailed pre-shot weather and radiation forecasts, and their verification are discussed., Rept. on Vela Uniform, Proj. Shoal, Fallon, Nev., 26 Oct 1963. Sponsored also by the Atomic Energy Commission, Washington, D. C. Legibility of this document is in part unsatisfactory. Reproduction has been made from best available copy.

Documentation of meteorological parameters occurring just prior to, during, and for a period after each of the four events of the series was the primary object of Project 2.4 (Micro-meteorological measurements). The meteorological parameters desired were wind speeds and directions from the surface to 3,000 ft above it, temperature profile in the same layer, and turbulence measurements. The wind data and temperature data were required to be continuously monitored at the control point during each event. This required various types of telemetering and communications. Surface wind data were collected using sensors on 30-ft towers at locations in the downwind array. M-33 radars sited along the border of each array, with remote release points down the array centerlines, were used to obtain event winds-aloft profiles. Two 120-ft United Kingdom (UK) towers near each GZ supplied additional wind data at the 60-ft and 120-ft levels plus gustmeter data for turbulence evaluation. Pibal crews obtained gross scale wind features for use by event weather briefers. A tethered United Kingdom balloon with sensors at 100-ft intervals obtained vertical temperature profiles. Also at each event shot time, United States Weather Bureau (USWB) personnel obtained a temperature sounding using modified rawinsonde equipment. (Author), Report on Operation Roller Coaster, Project 2.4.