An Investigation on the Influence of a Biofilm Fertilizer on Plant Growth and Soil Geophysical Properties

A biofilm is a grouping of one or more types of microorganisms in which cells stick together. Atmospheric nitrogen (N2) can be converted into ammonia (NH3) by organisms in a process called biological nitrogen fixation, becoming more bioavailable for plants to use. Anabaena cylindrica is a non-toxic nitrogen-fixing cyanobacteria (NFC) that has been proposed for use as a biofertilizer.https://digitalcommons.mtech.edu/urp_aug_2017/1009/thumbnail.jp

An investigation of sand transport phenomena in the Rappahannock River estuary, Virginia

Quantitative evidence supplied by bottom sediment textural analysis, Fourier grain-shape analysis and Q-mode factor analysis indicate that river-borne sand-sized sediment originating in the upper reaches of the Rappahannock is actively transported downstream and ultimately delivered to the estuarine sediment regime. Current velocity observations in the upper estuary as well as suspended sediment concentrations measured at stream gaging stations, indicate that short-term extreme hydrological events such as periodic river flooding provide a plausible transport mechanism to move river-borne sands into the estuarine sediment regime.Events of this nature can disrupt average partly-mixed estuarine circulation patterns by displacing the salt-wedge to a more seaward position, increase stratification and create a net-seaward river-type flow within the affected portions of the estuary; thus, allowing high concentrations of river-borne sediments associated with the high freshwater inflow to move into the estuary and become incorporated into the estuarine sediment regime. Bottom sediment textural analysis indicates that the two major landward sources of sand-sized sediment to the Rappahannock Estuary are the Piedmont-derived river sands and sand-sized sediment derived from the constant denudation of fastland bluff sediments which directly outcrop along certain reaches of the Rappahannock River. Sand-sized sediment is consistently present within all the bottom sediment samples taken from the estuary channel as well as along its flanking shoals. Fourier grain-shape analysis serves to differentiate the Piedmont-derived river sands from the fastland bluff sands in that the sand-sized sediment derived from each of these provenances possess highly contrastable shape attributes. Based upon the distribution of Fourier harmonic amplitudes of ninety-four sand-shape samples over a defined range Fourier harmonic amplitude class intervals, it is found that the river sands and fastland bluff sands represent two statistically non-similar sand-shape populations. The distribution of Fourier harmonic amplitudes also suggests that these two non-similar sand-shape populations mix together within the river\u27s active transport system landward of the Rappahannock Estuary. The proportional mixing of these two sand-shape populations and subsequent downriver transport results in the delivery of both shape populations into the estuarine sediment regime where they may become deposited and/or redistributed within the estuarine sediments. Q-mode factor analyis is employed in order to determine the relative extent of the proportional mixing of the two non-similar sand-shape populations within the active transport system of the Rappahannock River-Estuary via the grain-shape information supplied by Fourier analysis. Qmode analysis determined that three compositionally distinct end-members, or factor components, are sufficient enough to encompass 98.5% of the total grain-shape variance contained within the distribution of Fourier harmonic amplitudes for the ninetyfour sand-shape samples. Based upon the distribution these samples within the defined factor (variable) space, it is quantitatively determined that various percentages of the Piedmont-derived river sands are present within the bottom sediments of the Rappahannock Estuary both in the estuary channel as well as along its flanking shoal areas. Thus, Fourier grain-shape analysis proves as a useful geological tool in that it quantitatively determines that river-borne sand-sized sediment is present within the Rappahannock estuarine sediment regime

16-inch gun-launched anti-satellite weapon

This thesis determined the feasibility of developing a 16-inch, gun-launched anti-satellite weapon. The general performance capability of rocket-and scramjet-boosted, gun-launched vehicles is examined with regards to propelling a miniature homing vehicle to a satellite intercept altitude. Rocket and scramjet boost vehicle performance is modeled and optimum trajectories are determined. A low gun elevation at launch and a pop-up manuever are required to maximize the scramjet boost vehicle acceleration potential. The rocket boost vehicle is capable of intercepting a low altitude satellite without a pop-up manuever from a gun elevation of 45 degrees. Both boost methods provide apogees consistent with the intercept of known Soviet Electronic Intelligence Ocean Reconnaissance satellites, EORSAT, and Radar Ocean Reconnaissance satellites, RORSAT.http://archive.org/details/inchgunlaunchedn1094530406Approved for public release; distribution is unlimited

Reverse-engineering biological networks from large data sets

Much of contemporary systems biology owes its success to the abstraction of a network, the idea that diverse kinds of molecular, cellular, and organismal species and interactions can be modeled as relational nodes and edges in a graph of dependencies. Since the advent of high-throughput data-acquisition technologies in fields such as genomics, metabolomics, and neuroscience, the automated inference and reconstruction of such interaction networks directly from large sets of activation data, commonly known as reverse-engineering, has become a routine procedure. Whereas early attempts at network reverse-engineering focused predominantly on producing maps of system architectures with minimal predictive modeling, reconstructions now play instrumental roles in answering questions about the statistics and dynamics of the underlying systems they represent. Many of these predictions have clinical relevance, suggesting novel paradigms for drug discovery and disease treatment. While other reviews focus predominantly on the details and effectiveness of individual network inference algorithms, here we examine the emerging field as a whole. We first summarize several key application areas in which inferred networks have made successful predictions. We then outline the two major classes of reverse-engineering methodologies, emphasizing that the type of prediction that one aims to make dictates the algorithms one should employ. We conclude by discussing whether recent breakthroughs justify the computational costs of large-scale reverse-engineering sufficiently to admit it as a mainstay in the quantitative analysis of living systems.Fil: Natale, Joseph J.. University of Emory; Estados UnidosFil: Hofmann, David. University of Emory; Estados UnidosFil: Hernández Lahme, Damián Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina. University of Emory; Estados UnidosFil: Nemenman, Ilya. University of Emory; Estados Unido

Immediate and time dependent compression of tire derived aggregate

Journal of Geotechnical and Geoenvironmental Engineering, 133(3): pp. 245-256.This paper examines immediate and time-dependent compression of tire derived aggregate (TDA)and TDA-soil composites. To accommodate large particle sizes, modified experimental devices were developed and used to test tire chips and tire shreds. Immediate compression of TDA, which results almost entirely from the reduction of pore volume, increases with TDA content and tire particle size. The secant constrained modulus (Msec ) of TDA defined over the stress range of 0–50 kPa varied from a low of 255 kPa (100% tire shreds )to a high of 1,320 kPa (50% tire chips). A characteristic relationship between strain and time exists for TDA and TDA composites under one-dimensional confined compression. Time-dependent deformation is well described by the modified secondary compression index (Cae) which ranged from 0.0010 (50% tire chips) to 0.0074 (100% tire chips). Time-dependent deformation was inversely proportional to sand content, with the most significant changes resulting from the addition of 15% sand. Both applied stress and tire particle size appear to have a negligible effect on time-dependent compression of TDA. Based on the findings of this study it is recommended that practitioners assess time-dependent settlement when designing a TDA structure and if necessary incorporate design features to accommodate these settlements

Turbulent molecular gas and star formation in the shocked intergalactic medium of Stephan's Quintet

We report on single-dish radio CO observations towards the inter-galactic medium (IGM) of the Stephan's Quintet (SQ) group of galaxies. Extremely bright mid-IR H2 rotational line emission from warm molecular gas has been detected by Spitzer in the kpc-scale shock created by a galaxy collision. We detect in the IGM CO(1-0), (2-1) and (3-2) line emission with complex profiles, spanning a velocity range of 1000 km/s. The spectra exhibit the pre-shock recession velocities of the two colliding gas systems (5700 and 6700 km/s), but also intermediate velocities. This shows that much of the molecular gas has formed out of diffuse gas accelerated by the galaxy-tidal arm collision. A total H2 mass of 5x10^9 Msun is detected in the shock. The molecular gas carries a large fraction of the gas kinetic energy involved in the collision, meaning that this energy has not been thermalized yet. The turbulent kinetic energy of the H2 gas is at least a factor of 5 greater than the thermal energy of the hot plasma heated by the collision. The ratio between the warm H2 mass derived from Spitzer IRS spectroscopy and the H2 mass derived from CO fluxes is ~0.3 in the IGM of SQ, which is 10-100 times higher than in star-forming galaxies. In the shocked region, the ratio of the PAH-to-CO surface luminosities, commonly used to measure the star formation efficiency of the H2 gas, is lower (up to a factor 75) than the observed values in star-forming galaxies. We suggest that turbulence fed by the galaxy-tidal arm collision maintains a high heating rate within the H2 gas. This interpretation implies that the velocity dispersion on the scale of giant molecular clouds in SQ is one order of magnitude larger than the Galactic value. The high amplitude of turbulence may explain why this gas is not forming stars efficiently. [abridged version]Comment: Revised abstract and small editing to match published version. 15 pages, 5 figures. Accepted for publication in Ap