Experimental Overlay of Glazon over Two Bridge Decks

In accordance with a Personal Service Agreement entered into with the Glazon Industries, Inc., on July 2, 1971, the two subject decks were patched and overlayed with Glazon. On July 27, 1971, work started on RP 106-286-HG3, KY 395 bridge over I 64 in Shelby County. Work consisted of routing old concrete and sandblasting the surface (Figures 1 and 2). State personnel and equipment were used for all cleaning operations. The same procedures were followed to clean HM 99-1324A-MB3 in Powell County near Clay City. On July 28, 1971, Glazon personnel and equipment arrived at the work site in Shelby County. Glazon representatives judged the cleaning adequate and proceeded with patching the southbound lane (Figure 3). No accurate information is available as to the exact formulation of the Glazon used or proportions in the mix. Glazon Industries declined disclosure of such information since their material was not patented. Before patching, the holes were thoroughly dried. Shrinkage and cracking were noticed in the patches shortly after drying (Figure 4). Later, on other lanes, patch holes were primed with a Glazon liquid before patching (Figures 5 and 6). After a short drying period, the deck was sprayed with a Glazon mix similar to that for patching but more fluid (Figures 7 and 8). Some problems were encountered due to weak air supply, but were shortly overcome. The sprayed deck looked satisfactory to Glazon personnel who did most of the work in patching and overlaying the deck. The operation was moved to the Clay City bridge and the same procedures were followed in working the northbound lane. Two wingwalls on the Shelby County bridge were sprayed with a Glazon mix made with white cement. On August 3, 1971, both bridges were completed though work was interrupted by rain several times. On August 5, 1971, both bridges were reopened to two-lane traffic. This Division closely observed these operations from the beginning. It was later learned from the Division of Maintenance that the northbound lane of the Shelby County deck, which was badly deteriorating, had been repaired on September 15, 1971

Tunable exciton interactions in optical lattices with polar molecules

Rotational excitation of polar molecules trapped in an optical lattice gives rise to rotational excitons. Here we show that non-linear interactions of such excitons can be controlled by an electric field. The exciton--exciton interactions can be tuned to induce exciton pairing, leading to the formation of biexcitons. Tunable non-linear interactions between excitons can be used for many applications ranging from the controlled preparation of entangled quasiparticles to the study of polaron interactions and the effects of non-linear interactions on quantum energy transport in molecular aggregates.Comment: Some typos have been corrected in this versio

Spectral signatures of photosynthesis II: coevolution with other stars and the atmosphere on extrasolar worlds

As photosynthesis on Earth produces the primary signatures of life that can be detected astronomically at the global scale, a strong focus of the search for extrasolar life will be photosynthesis, particularly photosynthesis that has evolved with a different parent star. We take planetary atmospheric compositions simulated by Segura, et al. (2003, 2005) for Earth-like planets around observed F2V and K2V stars, modeled M1V and M5V stars, and around the active M4.5V star AD Leo; our scenarios use Earth's atmospheric composition as well as very low O2 content in case anoxygenic photosynthesis dominates. We calculate the incident spectral photon flux densities at the surface of the planet and under water. We identify bands of available photosynthetically relevant radiation and find that photosynthetic pigments on planets around F2V stars may peak in absorbance in the blue, K2V in the red-orange, and M stars in the NIR, in bands at 0.93-1.1 microns, 1.1-1.4 microns, 1.5-1.8 microns, and 1.8-2.5 microns. In addition, we calculate wavelength restrictions for underwater organisms and depths of water at which they would be protected from UV flares in the early life of M stars. We estimate the potential productivity for both surface and underwater photosynthesis, for both oxygenic and anoxygenic photosynthesis, and for hypothetical photosynthesis in which longer wavelength, multi-photosystem series are used.Comment: 59 pages, 4 figures, 4 tables, forthcoming in Astrobiology ~March 200

Constant amplitude and post-overload fatigue crack growth behavior in PM aluminum alloy AA 8009

A recently developed, rapidly solidified, powder metallurgy, dispersion strengthened aluminum alloy, AA 8009, was fatigue tested at room temperature in lab air. Constant amplitude/constant delta kappa and single spike overload conditions were examined. High fatigue crack growth rates and low crack closure levels compared to typical ingot metallurgy aluminum alloys were observed. It was proposed that minimal crack roughness, crack path deflection, and limited slip reversibility, resulting from ultra-fine microstructure, were responsible for the relatively poor da/dN-delta kappa performance of AA 8009 as compared to that of typical IM aluminum alloys

Comparison of baseline drinking practices, knowledge, and attitudes of adult s residing in communities taking part in the FAS prevention study in South Africa

Foetal Alcohol Syndrome (FAS) has been identified as among the most serious consequences associated with hazardous and harmful drinking in the Western Cape province, South Africa. Community surveys were conducted in two wine growing regions in this province to assess drinking behaviour, guide interventions and serve as a baseline for assessing the impact of population-level interventions. As part of a cross-sectional comparative study interviews were conducted with 384 and 209 randomly selected adults in the prevention (PC) and comparison communities (CC) respectively. Over 80% of respondents resided in urban areas, except inthe CC, where 61% of males resided on farms. Symptoms of hazardous or harmful drinking were reported by 16.0% of females and 32.5% of males in the PC, while 19.3% of females and 56.2% of males in the CC reported such drinking. Over two-thirds of respondents indicated that it was equally harmful for a woman to drink during any of the trimesters of pregnancy, but more than 30% of the women interviewed had never had a health worker speak to them about the effects of drinking during pregnancy. Over 10% had never heard of fetal alcohol syndrome. The findings reinforce the need for interventions to address hazardous/harmful use of alcohol inboth communities and also to address gaps in knowledge regarding the effects of drinking during pregnancy.Key Words: Alcohol, epidemiology, pregnancy, South Afric

Non-Markovian stochastic description of quantum transport in photosynthetic systems

We analyze several aspects of the transport dynamics in the LH1-RC core of purple bacteria, which consists basically in a ring of antenna molecules that transport the energy into a target molecule, the reaction center, placed in the center of the ring. We show that the periodicity of the system plays an important role to explain the relevance of the initial state in the transport efficiency. This picture is modified, and the transport enhanced for any initial state, when considering that molecules have different energies, and when including their interaction with the environment. We study this last situation by using stochastic Schr{\"o}dinger equations, both for Markovian and non-Markovian type of interactions.Comment: 21 pages, 5 figure

Atomic Force Microscopy of DNA, Nucleoproteins and Cellular Complexes: The Use of Functionalized Substrates

Progress towards rapid and simple characterization of biomolecular samples by scanning probe microscopy is impeded mainly by limitations of the current approach to sample preparation. We are working on approaches based on chemical functionalization of mica. Treatment of mica with aminopropyltriethoxy silane (APTES) makes the surface positively charged (AP-mica) and able to hold DNA in place for imaging, even in water. We have shown that AP-mica is an appropriate substrate for numerous nucleoprotein complexes as well. The AFM images of the complex of DNA with RecA protein are stable and indicate a structural periodicity for this filament. AP-mica holds strongly such large DNA complexes as kinetoplast DNA (kDNA) and is an appropriate substrate for their imaging with AFM. We have further develop this approach for making hydrophobic substrates. Silylation of mica surface with hexamethyldisilazane (Me-mica) allowed us to get AFM images of chlorosomes, an antenna complex isolated from green photosynthetic bacteria. Me-mica may be converted into a positively charged substrate after treatment with water solutions of tetraethylammonium bromide or cetyltrimethylammonium bromide. These activated surfaces show high activity towards binding the DNA molecules

Distribution of entanglement in light-harvesting complexes and their quantum efficiency

Recent evidence of electronic coherence during energy transfer in photosynthetic antenna complexes has reinvigorated the discussion of whether coherence and/or entanglement has any practical functionality for these molecular systems. Here we investigate quantitative relationships between the quantum yield of a light-harvesting complex and the distribution of entanglement among its components. Our study focusses on the entanglement yield or average entanglement surviving a time scale comparable to the average excitation trapping time. As a prototype system we consider the Fenna-Matthews-Olson (FMO) protein of green sulphur bacteria and show that there is an inverse relationship between the quantum efficiency and the average entanglement between distant donor sites. Our results suggest that longlasting electronic coherence among distant donors might help modulation of the lightharvesting function.Comment: Version accepted for publication in NJ

Long-lived quantum coherence in photosynthetic complexes at physiological temperature

Photosynthetic antenna complexes capture and concentrate solar radiation by transferring the excitation to the reaction center which stores energy from the photon in chemical bonds. This process occurs with near-perfect quantum efficiency. Recent experiments at cryogenic temperatures have revealed that coherent energy transfer - a wavelike transfer mechanism - occurs in many photosynthetic pigment-protein complexes (1-4). Using the Fenna-Matthews-Olson antenna complex (FMO) as a model system, theoretical studies incorporating both incoherent and coherent transfer as well as thermal dephasing predict that environmentally assisted quantum transfer efficiency peaks near physiological temperature; these studies further show that this process is equivalent to a quantum random walk algorithm (5-8). This theory requires long-lived quantum coherence at room temperature, which never has been observed in FMO. Here we present the first evidence that quantum coherence survives in FMO at physiological temperature for at least 300 fs, long enough to perform a rudimentary quantum computational operation. This data proves that the wave-like energy transfer process discovered at 77 K is directly relevant to biological function. Microscopically, we attribute this long coherence lifetime to correlated motions within the protein matrix encapsulating the chromophores, and we find that the degree of protection afforded by the protein appears constant between 77 K and 277 K. The protein shapes the energy landscape and mediates an efficient energy transfer despite thermal fluctuations. The persistence of quantum coherence in a dynamic, disordered system under these conditions suggests a new biomimetic strategy for designing dedicated quantum computational devices that can operate at high temperature.Comment: PDF files, 15 pages, 3 figures (included in the PDF file

Sensitivities of Low Energy Reactor Neutrino Experiments

The low energy part of the reactor neutrino spectra has not been experimentally measured. Its uncertainties limit the sensitivities in certain reactor neutrino experiments. The origin of these uncertainties are discussed, and the effects on measurements of neutrino interactions with electrons and nuclei are studied. Comparisons are made with existing results. In particular, the discrepancies between previous measurements with Standard Model expectations can be explained by an under-estimation of the low energy reactor neutrino spectra. To optimize the experimental sensitivities, measurements for \nuebar-e cross-sections should focus on events with large ($>$1.5 MeV) recoil energy while those for neutrino magnetic moment searches should be based on events $<$100 keV. The merits and attainable accuracies for neutrino-electron scattering experiments using artificial neutrino sources are discussed.Comment: 25 pages, 9 figure