Gamble mode: Resonance contact mode in atomic force microscopy

Active noise reduction has been accomplished in atomic force microscopy by applying a high frequency, low amplitude vibration to the cantilever while it is in contact with a surface. The applied excitation (>~ 200 kHz; ~ 1 nm) is acoustically coupled to the tip and dampens the resonance Q factors of the system. The applied frequency is well above the bandwidth of the acquisition system (50 kHz). We call this mode "gamble mode" or "resonance contact.

The 1980 land cover for the Puget Sound region

Both LANDSAT imagery and the video information communications and retrieval software were used to develop a land cover classifiction of the Puget Sound of Washington. Planning agencies within the region were provided with a highly accurate land cover map registered to the 1980 census tracts which could subsequently be incorporated as one data layer in a multi-layer data base. Many historical activities related to previous land cover mapping studies conducted in the Puget Sound region are summarized. Valuable insight into conducting a project with a large community of users and in establishing user confidence in a multi-purpose land cover map derived from LANDSAT is provided

Noise reduction in atomic force microscopy: Resonance contact mode

Noise reduction has been accomplished in atomic force microscopy by applying a high frequency, low amplitude vibration to the cantilever while it is in contact with a surface. The applied excitation (>~200 kHz; ~1 nm) is acoustically coupled to the tip and dampens the resonance Q factors of the system. The applied frequency is well above the bandwidth of the acquisition system (50 kHz). We call this mode "resonance contact" mode. The nonlinear behavior of the tip–sample interaction allows the high frequency excitation to effectively broaden the frequency response of the system resonances

Quartification with T' Flavor

In the simplest (non-quiver) unified theories, fermion families are often treated sequentially and a flavor symmetry may act similarly. As an alternative with non-sequential flavor symmetry, we consider a model based on the group (T'*Z_2)_global * [SU(3)^4]_local which combines the predictions of T' flavor symmetry with the features of a unified quiver gauge theory. The model accommodates the relationships between mixing angles separately for neutrinos, and for quarks, which have been previously predicted with T'. This quiver unification theory makes predictions of several additional gauge bosons and bifundamental fermions at the TeV scale.Comment: 8 pages, LaTex; added references and clarifie

Measurements and calculations of the Coulomb cross section for the production of direct electron pairs by energetic heavy nuclei in nuclear track emulsion

Measurements and theoretical predictions of the Coulomb cross section for the production of direct electron pairs by heavy ions in emulsion have been performed. Nuclear track emulsions were exposed to the 1.8 GeV/amu Fe-56 beam at the Lawrence Berkeley Laboratory bevalac and to the 60 and 200 GeV/amu O-16 and the 200 GeV/amu S-32 beam at the European Center for Nuclear Research Super Proton Synchrotron modified to accelerate heavy ions. The calculations combine the Weizsacker-Williams virtual quanta method applicable to the low-energy transfers and the Kelner-Kotov relativistic treatment for the high-energy transfers. Comparison of the measured total electron pair yield, the energy transfer distribution, and the emission angle distribution with theoretical predictions revealed a discrepancy in the frequency of occurrence of the low-energy pairs (less than or = 10 MeV). The microscope scanning criteria used to identify the direct electron pairs is described and efforts to improve the calculation of the cross section for pair production are also discussed

New calculations and measurements of the Coulomb cross-section for the production of direct electron pairs by high energy nuclei

Recently, new calculations were made of the direct Coulomb pair cross section that rely less in arbitrary parameters. More accurate calculations of the cross section down to low pair energies were made. New measurements of the total direct electron pair yield, and the energy and angular distribution of the electron pairs in emulsion were made for O-16 at 60 and 200 GeV/amu at S-32 at 200 GeV/amu which give satisfactory agreement with the new calculations. These calculations and measurements are presented along with previous accelerator measurements made of this effect during the last 40 years. The microscope scanning criteria used to identify the direct electron pairs is described. Prospects for application of the pair method to cosmic ray energy measurements in the region 10 (exp 13) to 10 (exp 15) eV/amu are discussed

Searching for axion stars and QQ-balls with a terrestrial magnetometer network

Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q-balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q-balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown that a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q-ball could be detected over a broad range of unexplored parameter space

An On-the-Road Comparison of In-Vehicle Navigation Assistance Systems

We compared system performance and driver opinion of 3 in-vehicle navigation aids - two advanced traveler information systems (ATISs; Ali-Scout and TetraStar) and written instructions - when used on the road concurrently under identical conditions. Few drivers in the study had difficulty finding initial routes or became lost. Users of Ali-Scout, an ATIS that utilizes traffic information in routing, drove longer-distance routes, got lost more frequently, and gave their system less positive ratings than did TetraStar users. Users of the 2 ATISs traversed routes that were significantly shorter in duration than those driven by users of written instructions. The time savings benefit of the advanced technology systems over written instructions was greatest during peak traffic conditions. Drivers who were familiar with the road network, overall, had less difficulty finding destinations and drove shorter-duration routes than drivers who were unfamiliar with the road network. Actual or potential applications of this research include improving the design of technologies that provide navigation assistance to travelers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67382/2/10.1518_001872099779591222.pd