Study of bonding methods for flip chip and beam leaded devices

The results are presented of a comprehensive study and evaluation for the bonding of flip chip and beam leaded devices onto hybrid microcircuit substrates used in high reliability space applications. The program included the evaluation of aluminum flip chips, solder (silver/tin) bump chips, gold beam leaded devices, and aluminum beam leaded devices

NASA micromin computer Monthly progress letter, Jan. 1967

Microminiature circuit development for flight control computer

The First Naval War College Seapower Symposium

The following address was delivered by Vice Admiral Richard C. Colbert, President, Naval War College as the welcoming remarks to the U.S. Naval War College Seapower Symposium held in Newport, R.I. from 17 to 20 November 1969

Hydrogen adsorption and cohesive energy of single-walled carbon nanotubes

Hydrogen adsorption on crystalline ropes of carbon single-walled nanotubes (SWNT) was found to exceed 8 wt.%, which is the highest capacity of any carbon material. Hydrogen is first adsorbed on the outer surfaces of the crystalline ropes. At pressures higher than about 40 bar at 80 K, however, a phase transition occurs where there is a separation of the individual SWNTs, and hydrogen is physisorbed on their exposed surfaces. The pressure of this phase transition provides a tube-tube cohesive energy for much of the material of 5 meV/C atom. This small cohesive energy is affected strongly by the quality of crystalline order in the ropes

Observational Evidence for Intermediate-Mass Black Holes in Ultra-luminous X-ray Sources

Evidence is mounting that some Ultra-luminous X-ray sources (ULXs) may contain accreting intermediate-mass black holes (IMBHs). We review the current observational evidence for IMBH-ULXs. While low-luminosity ULXs with L_X <~ 10^39.5 erg/s (assuming isotropic emission) are consistent with mildly X-ray beamed high-mass X-ray binaries, there are a considerable number of ULXs with larger X-ray luminosities that are not easily explained by these models. Recent high-S/N XMM X-ray spectra are showing an increasing number of ULXs with ``cool disks'' -- accretion disks with multi-color blackbody inner disk temperatures kT_in ~ 0.1-0.2 keV, consistent with accreting IMBHs. Optical emission-line studies of ULX nebulae provide useful measurements of X-ray energetics, and can thus determine if the X-rays are emitted isotropically. Analysis of an optical spectrum of the Ho II ULX nebulae implies an X-ray energy source with ~10^40 erg/s is present, suggesting an isotropically-emitting IMBH. The spatial coincidence of ULXs with dense star clusters (young clusters and globular clusters) suggests that IMBHs formed in these clusters could be the compact objects in the associated ULXs. Quasi-periodic oscillations and frequency breaks in XMM power-density spectra of ULXs also suggest that the black hole masses are more consistent with IMBHs than stellar-mass black holes. Since _all_ of these ULXs with evidence for IMBHs are high-luminosity ULXs, i.e., L_X >~ 10^40 ergs, we suggest that this class of ULXs is generally powered by accreting IMBHs.Comment: Invited review talk at the Tenth Marcel Grossmann Meeting on General Relativity, Rio de Janeiro, July 20-26, 2003. Proceedings edited by M. Novello, S. Perez-Bergliaffa and R. Ruffini, World Scientific, Singapore, 2005. Full resolution version of this paper available at http://blackhole.phys.cua.edu/Colbert_MGX.pd

High-Molecular-Weight Human Epidermal Transglutaminase

Human stratum corneum was extracted in Tris-HCl containing EDTA and phenylmethylsulfonyl fluoride, separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transblotted to nitrocellulose papers and reacted with rabbit antihuman epidermal transglutaminase (ETG) antibody. Protein-bound antibody was detected with a multistep peroxidase procedure. Proteins with a molecular weight of 50,000 (50kDa) and 72,000 daltons (72kDa) were stained when anti-ETG Was used and not when second antibody alone or sera from nonimmunized animals were used. When ETG was treated with trypsin or organic solvents, there was no alteration in the mobility of the 50kDa ETC band, but there was complete disappearance of the 72kDa band. Antibody that bound 72kDa protein, when eluted from the blot, reacted with both 50kDa and 72kDa proteins; similarly, antibody that bound to the 50kDa protein, when eluted from the blot, reacted with both the 50kDa and 72kDa proteins. Partially purified 72kDa ETG activity was increased (3 to 16 times control levels) after heating at 56°C in the presence of calcium and dithiothreitol or by treatment with trypsin. These studies, in conjunction with the previous studies of ETG activation, are consistent with there being two forms of ETG. The different forms may play a role in regulating enzyme activity

Rotating black hole orbit functionals in the frequency domain

In many astrophysical problems, it is important to understand the behavior of functions that come from rotating (Kerr) black hole orbits. It can be particularly useful to work with the frequency domain representation of those functions, in order to bring out their harmonic dependence upon the fundamental orbital frequencies of Kerr black holes. Although, as has recently been shown by W. Schmidt, such a frequency domain representation must exist, the coupled nature of a black hole orbit's $r$ and $\theta$ motions makes it difficult to construct such a representation in practice. Combining Schmidt's description with a clever choice of timelike coordinate suggested by Y. Mino, we have developed a simple procedure that sidesteps this difficulty. One first Fourier expands all quantities using Mino's time coordinate $\lambda$. In particular, the observer's time $t$ is decomposed with $\lambda$. The frequency domain description is then built from the $\lambda$-Fourier expansion and the expansion of $t$. We have found this procedure to be quite simple to implement, and to be applicable to a wide class of functionals. We test the procedure using a simple test function, and then apply it in a particularly interesting case, the Weyl curvature scalar $\psi_4$ used in black hole perturbation theory.Comment: 16 pages, 2 figures. Submitted to Phys Rev D. New version gives a vastly improved algorithm due to Drasco for computing the Fourier transforms. Drasco has been added as an author. Also fixed some references and exterminated a small herd of typos; final published versio

A First Estimate Of The X-Ray Binary Frequency As A Function Of Star Cluster Mass In A Single Galactic System

We use the previously-identified 15 infrared star-cluster counterparts to X-ray point sources in the interacting galaxies NGC 4038/4039 (the Antennae) to study the relationship between total cluster mass and X-ray binary number. This significant population of X-Ray/IR associations allows us to perform, for the first time, a statistical study of X-ray point sources and their environments. We define a quantity, \eta, relating the fraction of X-ray sources per unit mass as a function of cluster mass in the Antennae. We compute cluster mass by fitting spectral evolutionary models to K_s luminosity. Considering that this method depends on cluster age, we use four different age distributions to explore the effects of cluster age on the value of \eta and find it varies by less than a factor of four. We find a mean value of \eta for these different distributions of \eta = 1.7 x 10^-8 M_\sun^-1 with \sigma_\eta = 1.2 x 10^-8 M_\sun^-1. Performing a \chi^2 test, we demonstrate \eta could exhibit a positive slope, but that it depends on the assumed distribution in cluster ages. While the estimated uncertainties in \eta are factors of a few, we believe this is the first estimate made of this quantity to ``order of magnitude'' accuracy. We also compare our findings to theoretical models of open and globular cluster evolution, incorporating the X-ray binary fraction per cluster.Comment: 20 pages, 6 figures, accepted by Ap

Far-ultraviolet imaging of the Hubble Deep Field-North: Star formation in normal galaxies at z < 1

We present far-ultraviolet (FUV) imaging of the Hubble Deep Field-North (HDF-N) taken with the Solar Blind Channel of the Advanced Camera for Surveys (ACS SBC) and the FUV MAMA detector of the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope. The full WFPC2 deep field has been observed at 1600 Å. We detect 134 galaxies and one star down to a limit of FUV_(AB) ~ 29. All sources have counterparts in the WFPC2 image. Redshifts (spectroscopic or photometric) for the detected sources are in the range 0 < z < 1. We find that the FUV galaxy number counts are higher than those reported by GALEX, which we attribute at least in part to cosmic variance in the small HDF-N field of view. Six of the 13 Chandra sources at z < 0.85 in the HDF-N are detected in the FUV, and those are consistent with starbursts rather than active galactic nuclei. Cross-correlating with Spitzer sources in the field, we find that the FUV detections show general agreement with the expected L_(IR)/L_(UV) versus β relationship. We infer star formation rates (SFRs), corrected for extinction using the UV slope, and find a median value of 0.3 M_☉ yr^(-1) for FUV-detected galaxies, with 75% of detected sources having SFR < 1 M_☉ yr^(-1). Examining the morphological distribution of sources, we find that about half of all FUV-detected sources are identified as spiral galaxies. Half of morphologically selected spheroid galaxies at z < 0.85 are detected in the FUV, suggesting that such sources have had significant ongoing star formation in the epoch since z ~ 1