Stratigraphic Excavations within the Gournia Palace 2011-2014

Gallimore, S., and K.T. Glowacki. “Stratigraphic Excavations within the Gournia Palace 2011-2014.” Abstract of paper read at the 119th Annual Meeting of the Archaeological Institute of America, Boston, Massachusetts, January 7, 2018.Recent excavations within the Gournia palace have revealed much new evidence for the occupation of the site prior to the construction of the Neopalatial complex and for the formation processes, ritual activities, and architectural development and phasing of the palace itself. In the central portion of the palace (rooms 18, 19, 20, 20a), a deep early Protopalatial (MM IB) fill of pebbles retained by a large terrace wall covered an even earlier, Protopalatial, boulder-paved area. Immediately on top of the fill levels, a small room was first established and later filled with secondary and tertiary cultural deposits, all still within the early Protopalatial period. Although in situ finds do not allow us to establish the room’s function with certainty, architectural details such as a series of low, narrow benches that lined the room’s interior and exterior facades may suggest some type of non-domestic, perhaps ritual, purpose for the enigmatic enclosure. In the southern and southwestern portions of the Neopalatial complex (rooms 13-18b), excavation immediately below the levels reached by Hawes discovered a number of important cultural levels that shed new light on this part of the structure. Significant findings include evidence for initial construction of the palace in the early Neopalatial period (MM III) along with major renovations at the beginning of LM IB. Systematic excavations have also revealed at least two LM IB destruction levels, important ceremonial and feasting deposits in Rooms 13 and 17, the first Linear A tablet to be recovered from Gournia, and detailed evidence for the function (e.g., storage, ritual, access) of these various spaces within the palace

Stratigraphic Excavations within the Gournia Palace 2011-2014

Gallimore, S., and K.T. Glowacki. “Stratigraphic Excavations within the Gournia Palace 2011-2014.” Abstract of paper read at the 119th Annual Meeting of the Archaeological Institute of America, Boston, Massachusetts, January 7, 2018.Recent excavations within the Gournia palace have revealed much new evidence for the occupation of the site prior to the construction of the Neopalatial complex and for the formation processes, ritual activities, and architectural development and phasing of the palace itself. In the central portion of the palace (rooms 18, 19, 20, 20a), a deep early Protopalatial (MM IB) fill of pebbles retained by a large terrace wall covered an even earlier, Protopalatial, boulder-paved area. Immediately on top of the fill levels, a small room was first established and later filled with secondary and tertiary cultural deposits, all still within the early Protopalatial period. Although in situ finds do not allow us to establish the room’s function with certainty, architectural details such as a series of low, narrow benches that lined the room’s interior and exterior facades may suggest some type of non-domestic, perhaps ritual, purpose for the enigmatic enclosure. In the southern and southwestern portions of the Neopalatial complex (rooms 13-18b), excavation immediately below the levels reached by Hawes discovered a number of important cultural levels that shed new light on this part of the structure. Significant findings include evidence for initial construction of the palace in the early Neopalatial period (MM III) along with major renovations at the beginning of LM IB. Systematic excavations have also revealed at least two LM IB destruction levels, important ceremonial and feasting deposits in Rooms 13 and 17, the first Linear A tablet to be recovered from Gournia, and detailed evidence for the function (e.g., storage, ritual, access) of these various spaces within the palace

Optical processing for distributed sensors in control of flexible spacecraft

A recent potential of distributed image processing is discussed. Applications in the control of flexible spacecraft are emphasized. Devices are currently being developed at NASA and in universities and industries that allow the real-time processing of holographic images. Within 5 years, it is expected that, in real-time, one may add or subtract holographic images at optical accuracy. Images are stored and processed in crystal mediums. The accuracy of their storage and processing is dictated by the grating level of laser holograms. It is far greater than that achievable using current analog-to-digital, pixel oriented, image digitizing and computing techniques. Processors using image processing algebra can conceptually be designed to mechanize Fourier transforms, least square lattice filters, and other complex control system operations. Thus, actuator command inputs derived from complex control laws involving distributed holographic images can be generated by such an image processor. Plans are revealed for the development of a Conjugate Optics Processor for control of a flexible object

Structural development of laminar flow control aircraft chordwise wing joint designs

For laminar flow to be achieved, any protuberances on the surface must be small enough to avoid transition to turbulent flow. However, the surface must have joints between the structural components to allow assembly or replacement of damaged parts, although large continuous surfaces can be utilized to minimize the number the number of joints. Aircraft structural joints usually have many countersunk bolts or rivets on the outer surface. To maintain no mismatch on outer surfaces, it is desirable to attach the components from the inner surface. It is also desirable for the panels to be interchangeable, without the need for shims at the joint, to avoid surface discontinuities that could cause turbulence. Fabricating components while pressing their outer surfaces against an accurate mold helps to ensure surface smoothness and continuity at joints. These items were considered in evaluating the advantages and disadvantages of the joint design concepts. After evaluating six design concepts, two of the leading candidates were fabricated and tested using many small test panels. One joint concept was also built and tested using large panels. The small and large test panel deflections for the leading candidate designs at load factors up to +1.5 g's were well within the step and waviness requirements for avoiding transition.The small panels were designed and tested for compression and tension at -65 F, at ambient conditions, and at 160 F. The small panel results for the three-rib and the sliding-joint concepts indicated that they were both acceptable. The three-rib concept, with tapered splice plates, was considered to be the most practical. A modified three-rib joint that combined the best attributes of previous candidates was designed, developed, and tested. This improved joint met all of the structural strength, surface smoothness, and waviness criteria for laminar flow control (LFC). The design eliminated all disadvantages of the initial three-rib concept except for unavoidable eccentricity, which was reduced and reacted satisfactorily by the rib supports. It should also result in a relatively simple low-cost installation, and makes it easy to replace any panels damaged in the field

Investigation of Channel Interactions in Nested Hall Thruster

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143065/1/1.B36352.pd

A direct image of the obscuring disk surrounding an active galactic nucleus

Active galactic nuclei (AGN) are generally accepted to be powered by the release of gravitational energy in a compact accretion disk surrounding a massive black hole. Such disks are also necessary to collimate powerful radio jets seen in some AGN. The unifying classification schemes for AGN further propose that differences in their appearance can be attributed to the opacity of the accreting material, which may obstruct our view of the central region of some systems. The popular model for the obscuring medium is a parsec-scale disk of dense molecular gas, although evidence for such disks has been mostly indirect, as their angular size is much smaller than the resolution of conventional telescopes. Here we report the first direct images of a pc-scale disk of ionised gas within the nucleus of NGC 1068, the archetype of obscured AGN. The disk is viewed nearly edge-on, and individual clouds within the ionised disk are opaque to high-energy radiation, consistent with the unifying classification scheme. In projection, the disk and AGN axes align, from which we infer that the ionised gas disk traces the outer regions of the long-sought inner accretion disk.Comment: 14 pages, LaTeX, PSfig, to appear in Nature. also available at http://hethp.mpe-garching.mpg.de/Preprint

Strongly Non-Equilibrium Bose-Einstein Condensation in a Trapped Gas

We present a qualitative (and quantitative, at the level of estimates) analysis of the ordering kinetics in a strongly non-equilibrium state of a weakly interacting Bose gas, trapped with an external potential. At certain conditions, the ordering process is predicted to be even more rich than in the homogeneous case. Like in the homogeneous case, the most characteristic feature of the full-scale non-equilibrium process is the formation of superfluid turbulence.Comment: 4 pages, revtex, no figures. Submitted to PR

Parametric investigation of orifice aspect-ratio on low current hollow cathode power consumption

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76725/1/AIAA-1998-3345-942.pd

A Hall probe diagnostic for low density plasma accelerators

A Hall probe diagnostic was developed for use with plasma thrusters. The Hall generators were mounted at the end of a stainless steel tube heat exchanger. Ceramic cement and a Pyrex tube were used as radiation and particle flux shields, respectively. A thermocouple was used to monitor the temperature of the Hall generator. The low voltage output from the probe was amplified within one meter of the transducer to minimize the effect of noise pick up. A National Institute of Standards and Technology traceable Gaussmeter provided an absolute reference for calibration, and relative calibrations were performed both in a strong electric field and in situ during thruster operation to approximate the conditions in the discharge. The overall accuracy of the diagnostic was ±6 G.±6G. The probes were tested with a Hall-effect thruster, and provided sufficiently accurate data to estimate the magnitude of the closed-drift electron current. © 1998 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69868/2/RSINAK-69-6-2546-1.pd

Development of laminar flow control wing surface porous structure

It was concluded that the chordwise air collection method, which actually combines chordwise and spanwise air collection, is the best of the designs conceived up to this time for full chord laminar flow control (LFC). Its shallower ducting improved structural efficiency of the main wing box resulting in a reduction in wing weight, and it provided continuous support of the chordwise panel joints, better matching of suction and clearing airflow requirements, and simplified duct to suction source minifolding. Laminar flow control on both the upper and lower surfaces was previously reduced to LFC suction on the upper surface only, back to 85 percent chord. The study concludes that, in addition to reduced wing area and other practical advantages, this system would be lighter because of the increase in effective structural wing thickness