36,522 research outputs found
Study of infrared evaluation in qualification and failure analysis of semiconductor devices Final report, 28 Jun. 1967 - 10 Jun. 1969
Techniques for providing infrared data for use in failure analysis of semiconductor device
Climate in Earth history
Complex atmosphere-ocean-land interactions govern the climate system and its variations. During the course of Earth history, nature has performed a large number of experiments involving climatic change; the geologic record contains much information regarding these experiments. This information should result in an increased understanding of the climate system, including climatic stability and factors that perturb climate. In addition, the paleoclimatic record has been demonstrated to be useful in interpreting the origin of important resources-petroleum, natural gas, coal, phosphate deposits, and many others
The study of infrared evaluation in qualification and failure analysis of semiconductor devices Interim progress report, 28 Apr. - 28 Jul. 1968
Infrared display techniques and acceptance criteria for microcircuit qualification and semiconductor device failure analysi
A Modified Version of the Waxman Algorithm
The iterative algorithm recently proposed by Waxman for solving eigenvalue
problems, which relies on the method of moments, has been modified to improve
its convergence considerably without sacrificing its benefits or elegance. The
suggested modification is based on methods to calculate low-lying eigenpairs of
large bounded hermitian operators or matrices
Thermal neutron image intensifier tube provides brightly visible radiographic pattern
Vacuum-type neutron image intensifier tube improves image detection in thermal neutron radiographic inspection. This system converts images to an electron image, and with electron acceleration and demagnification between the input target and output screen, produces a bright image viewed through a closed circuit television system
New camera tube improves ultrasonic inspection system
Electron multiplier, incorporated into the camera tube of an ultrasonic imaging system, improves resolution, effectively shields low level circuits, and provides a high level signal input to the television camera. It is effective for inspection of metallic materials for bonds, voids, and homogeneity
Distribution of carbonate in surface sediments of the Pacific Ocean
The distribution of carbonate on the floor of the Pacific has been remapped on the basis of 1313 points from 80 references stored in the World Ocean Sediment Data Bank of Scripps Institution of Oceanography. Percent distribution maps and carbonate versus depth diagrams generally agree with previously published information and reflect the major controlling factors of carbonate sedimentation (depth, hydrography, fertility, and sedimentary processes). While carbonate distributions are of limited use in attempting to construct dissolution profiles, major trends are identifiable. In particular, the degree of lowering of the equatorial calcite compensation depth (CCD) together with an estimate of the differences in supply rates between the equator and the subtropical gyre can be used to estimate dissolution rate increase below the lysocline. There is considerable variation in the sharpness of the ‘CCD transition’ a concept defined here. This variation is thought to reflect both geographic differences in dissolution rate gradients and redeposition processes (carbonate, deep-sea sediments, calcite, and compensation depth)
Ontong Java Plateau, Leg 130: Synopsis of major drilling results
Sixteen holes were drilled at five sites on the northeastern flank of Ontong Java Plateau during Leg 130 (Sites 803 through 807). All of these sites are near the equator, but are at different depths (803: 02°26.0\u27N, 3410 m; 804: 01°00.3\u27N, 3861 m; 805: 01°13.7\u27N, 3188 m; 806: 00°19.1\u27N, 2520 m; and 807: 03°36.4\u27N, 2805 m). One of our goals was to obtain a depth transect of Neogene carbonate deposition for reconstructing the history of ocean climate, chemistry, and productivity, and for understanding the origin of acoustic reflectors. Another goal was to achieve considerable penetration into basement for elucidating the origin of the plateau. All sites yielded multiple Neogene sequences, which were cored using the advanced hydraulic piston corer (APC) to the ooze-chalk transition (10-14 Ma) and with the extended core barrel (XCB) below that. Sites 803 and 807 were drilled to basement and yielded incomplete Paleogene and Cretaceous sections. Penetration into basement was 25 m at Site 803 and 149 m at Site 807; 98 m of basalt was recovered. In all, we cored 5889 m, taking 639 cores. Of the record 4822 m recovered, 55% was taken with the APC, 39% with the XCB, and 6% with the rotary core barrel (RCB). All sites except Site 804 were logged. Neogene sedimentation rates were found to vary by more than a factor of 2, with a striking maximum in the latest Miocene to early Pliocene and a strong minimum in the Pleistocene. Fluctuations in carbonate content on the millionyear scale are highly coherent among depths over the last 12 m.y., perhaps less so before that. Many acoustic reflectors appear synchronous with carbonate reduction events (CREs) and other paleoceanographic events. Other reflectors are tied to diagenesis (e.g., the ooze-chalk transformation, which is diachronous). Recovery of the Cretaceous/Tertiary (K/T) boundary at Sites 803 and 807 demonstrates the presence of a deep carbonate-compensation depth (CCD) across the transition: one sequence is calcareous, the other is not. Because the K/T sections occur below and above major hiatuses, we postulate that special conditions for preservation existed during the transition. In addition, there is evidence of volcanic activity at that time. The basalts cored at Sites 803 and 807 are predominantly olivine-bearing and were erupted during the mid-Cretaceous. At Site 807, pillow lavas buried sediments. One thick flow (at about 28 m) was penetrated here, apparently a flood basalt. Magnetic paleolatitudes suggest that the Ontong Java Plateau has moved coherently with the Pacific Plate since the Early Cretaceous
Improving the Convergence of an Iterative Algorithm Proposed By Waxman
In the iterative algorithm recently proposed by Waxman for solving eigenvalue
problems, we point out that the convergence rate may be improved. For many
non-singular symmetric potentials which vanish asymptotically, a simple
analytical relationship between the coupling constant of the potential and the
ground state eigenvalue is obtained which can be used to make the algorithm
more efficient
Ni3TeO6 - a collinear antiferromagnet with ferromagnetic honeycomb planes
We report a comprehensive study of magnetic properties of Ni3TeO6. The system
crystallizes in a noncentrosymmetric rhombohedral lattice, space group R3.
There are three differently coordinated Ni atoms in the unit cell. Two of them
form an almost planar honeycomb lattice, while the third one is placed between
the layers. Magnetization and specific heat measurements revealed a single
magnetic ordering at TN = 52 K. Below TN the susceptibility with the magnetic
field parallel to the c-axis drops towards zero while the perpendicular
susceptibility remains constant, a characteristic of antiferromagnetic
materials. Neutron diffraction confirmed that the system is antiferromagnet
below TN with ferromagnetic ab-planes stacked antiferromagnetically along the
c-axis. All Ni moments are in the S = 1 spin state and point along the c-axis.Comment: accepted for publication in Journal of Physics Condensed Matte
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