Optical read out and feedback cooling of a nanostring optomechanical cavity

Optical measurement of the motion of a 940 kHz mechanical resonance of a silicon nitride nanostring resonator is demonstrated with a read out noise imprecision reaching 37 dB below that of the resonator's zero-point fluctuations. Via intensity modulation of the optical probe laser, radiation pressure feedback is used to cool and damp the mechanical mode from an initial room temperature occupancy of $\bar{n}_{b} = 6.5 \times 10^6$ ($T_{b}=295$K) down to a phonon occupation of $\langle n \rangle = 66 \pm 10$, representing a mode temperature of $T_{m} \approx 3$mK. The five decades of cooling is enabled by the system's large single-photon cooperativity $(C_{1} = 4)$ and high quantum efficiency of optical motion detection ($\eta_{t} = 0.27$).Comment: 13 pages, 13 figure

Viking orbiter stereo imaging catalog

The extremely long missions of the two Viking Orbiter spacecraft produced a wealth of photos of surface features. Many of which can be used to form stereo images allowing the earth-bound student of Mars to examine the subject in 3-D. This catalog is a technical guide to the use of stereo coverage within the complex Viking imaging data set. Since that data set is still growing (January, 1980, about 3 1/2 years after the mission began), a second edition of this catalog is planned with completion expected about November, 1980

Viking orbiter stereo imaging catalog

The extremely long mission of the two Viking Orbiter spacecraft produced a wealth of photos of surface features. Many of these photos can be used to form stereo images allowing the student of Mars to examine a subject in three dimensional. This catalog is a technical guide to the use of stereo coverage within the complex Viking imaging data set

Geology orbiter comparison study

Instrument requirements of planetary geology orbiters were examined with the objective of determining the feasibility of applying standard instrument designs to a host of terrestrial targets. Within the basic discipline area of geochemistry, gamma-ray, X-ray fluorescence, and atomic spectroscopy remote sensing techniques were considered. Within the discipline area of geophysics, the complementary techniques of gravimetry and radar were studied. Experiments using these techniques were analyzed for comparison at the Moon, Mercury, Mars and the Galilean satellites. On the basis of these comparative assessments, the adaptability of each sensing technique was judged as a basic technique for many targets, as a single instrument applied to many targets, as a single instrument used in different mission modes, and as an instrument capability for nongeoscience objectives

Studi Perbandingan Karakteristik Agregat Quarry Nangapanda Dan Quarry Aemau Untuk Lapis Pondasi Bawah (Sub Base)

Salah satu bahan penyusun perkerasan jalan adalah agregat,untuk itu perlu dilakukan penelitian terhadap karakteristik material agregat sebagai bahan dasar konstruksi jalan. Quarry Nangapanda dan quarry Aemau merupakan sumber material yang sering digunakan untuk pembangunan pekerjaan jalan di Kabupaten Ende dan Nagekeo. Tujuan Penelitian ini untuk mengetahui karakteristik agregat quarry Nangapanda dan quarry Aemau, serta perbandingan karakteristiknya untuk lapis pondasi bawah (sub base). Metode yang digunakan adalah Standar Nasional Indonesia (SNI). Hasil pengujian analisis saringan agregat dua quarry ini termasuk dalam tipikal gradasi seragam,berat jenis (bulk) quarry Nangapanda sebesar 2,53 dan quarry Aemau sebesar 2,84. Penyerapan (absorption) untuk quarry Nangapanda sebesar 2,81% dan quarry Aemau sebesar 1,60%,kadar air agregat quarry Nangapanda sebesar 1,51% dan quarry Aemau sebesar 1,075%,agregat yang lolos nomor 200 (0,075 mm) quarry Nangapanda sebesar 0,283% dan quarry Aemau sebesar 0,423%, keausan agregat quarry Nangapanda sebesar 18,30% dan quarry Aemau sebesar 12,06%. Hasil akhir agregat dua quarry ini sudah memenuhi syarat SNI dengan perbandingan karakteristik agregat quarry Aemau lebih baik dari agregat quarry Nangapanda

Complex conjugation and Shimura varieties

In this paper we study the action of complex conjugation on Shimura varieties and the problem of descending these to the maximal totally real field of the reflex field. We prove the existence of such descent for many Shimura varieties whose associated adjoint group has certain factors of type A or D. This includes a large family of Shimura varieties of abelian type. Our considerations and constructions are carried out purely at the level of Shimura data and group theory

Momentum and Heat Transfer in a Laminar Boundary Layer with Slip Flow

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77059/1/AIAA-22968-756.pd

The Keck Aperture Masking Experiment: Dust Enshrouded Red Giants

While the importance of dusty asymptotic giant branch (AGB) stars to galactic chemical enrichment is widely recognised, a sophisticated understanding of the dust formation and wind-driving mechanisms has proven elusive due in part to the difficulty in spatially-resolving the dust formation regions themselves. We have observed twenty dust-enshrouded AGB stars as part of the Keck Aperture Masking Experiment, resolving all of them in multiple near-infrared bands between 1.5 microns and 3.1 microns. We find 45% of the targets to show measurable elongations that, when correcting for the greater distances of the targets, would correspond to significantly asymmetric dust shells on par with the well-known cases of IRC+10216 or CIT6. Using radiative transfer models, we find the sublimation temperature of 1130 +- 90 K and 1170 +- 60 K for silicates and amorphous carbon respectively, both somewhat lower than expected from laboratory measurements and vastly below temperatures inferred from the inner edge of YSO disks. The fact that O-rich and C-rich dust types showed the same sublimation temperature was surprising as well. For the most optically-thick shells (tau > 2 at 2.2 microns), the temperature profile of the inner dust shell is observed to change substantially, an effect we suggest could arise when individual dust clumps become optically-thick at the highest mass-loss rates.Comment: accepted to Monthly Notices of the Royal Astronomical Societ

Coexistence of ferromagnetism and superconductivity in the hybrid ruthenate-cuprate compound RuSr_2GdCu_2O_8 studied by muon spin rotation (\mu SR) and DC-magnetization

We have investigated the magnetic and the superconducting properties of the hybrid ruthenate-cuprate compound RuSr_{2}GdCu_{2}O_{8} by means of zero-field muon spin rotation- (ZF-$\mu$SR) and DC magnetization measurements. The DC-magnetisation data establish that this material exhibits ferromagnetic order of the Ru-moments ($\mu (Ru) \approx 1 \mu_{B}$) below T_{Curie} = 133 K and becomes superconducting at a much lower temperature T_c = 16 K. The ZF-$\mu$SR experiments indicate that the ferromagnetic phase is homogeneous on a microscopic scale and accounts for most of the sample volume. They also suggest that the magnetic order is not significantly modified at the onset of superconductivity.Comment: improved version submitted to Phys. Rev.