Growth history of fault-related folds and interaction with seabed channels in the toe-thrust region of the deep-water Niger delta

The deep-water fold and thrust belt of the southern Niger Delta has prominent thrusts and folds oriented perpendicular to the regional slope that formed as a result of the thin-skinned gravitational collapse of the delta above overpressured shale. The thrust-related folds have grown in the last 12.8 Ma and many of the thrusts are still actively growing and influencing the pathways of modern seabed channels. We use 3D seismic reflection data to constrain and analyse the spatial and temporal variation in shortening of four thrusts and folds having seabed relief in a study area of 2600 km2 size in 2200–3800 m water depth. Using these shortening measurements, we have quantified the variation in strain rates through time for both fault-propagation and detachment folds in the area, and we relate this to submarine channel response. The total amount of shortening on the individual structures investigated ranges from 1 to 4 km, giving a time-averaged maximum shortening rate of between 90 ± 10 and 350 ± 50 m/Myr (0.1 and 0.4 mm/yr). Fold shortening varies both spatially and temporally: The maximum interval shortening rate occurred between 9.5 Ma and 3.7 Ma, and has reduced significantly in the last 3.7 Ma. We suggest that the reduction in the Pliocene-Recent fold shortening rate is a response to the slow-down in extension observed in the up-dip extensional domain of the Niger Delta gravitational system in the same time interval. In the area dominated by the fault-propagation folds, the channels are able to cross the structures, but the detachment fold is a more significant barrier and has caused a channel to divert for 25 km parallel to the fold axis. The two sets of structures have positive bathymetric expressions, with an associated present day uphill slope of between 1.5° and 2°. However, the shorter uphill slopes of the fault-propagation folds and increased sediment blanketing allow channels to cross these structures. Channels that develop coevally with structural growth and that cross structures, do so in positions of recent strain minima and at interval strain rates that are generally less than −0.02 Ma−1 (−1 × 10−16 s−1). However, the broad detachment fold has caused channel diversion at an even lower strain rate of c. −0.002 Ma−1 (−7 × 10−17 s−1)

Financial Troubleshooting

This publication describes a simple framework that farmers, lenders, or extension specialists can use to identify the type of financial problem a farm business is experiencing, clarify the underlying causes, and list a number of management responses that could contribute to its resolution.

Regenerable biocide delivery unit

A method and apparatus are disclosed for maintaining continuous, long-term microbial control in the water supply for potable, hygiene, and experimental water for space activities, as well as treatment of water supplies on Earth. The water purification is accomplished by introduction of molecular iodine into the water supply to impart a desired iodine residual. The water is passed through an iodinated anion exchange resin bed. The iodine is bound as I-(sub n) at the anion exchange sites and releases I(sub 2) into the water stream flowing through the bed. The concentration of I(sub 2) in the flowing water gradually decreases and, in the prior art, the ion-exchange bed has had to be replaced. In a preferred embodiment, a bed of iodine crystals is provided with connections for flowing water therethrough to produce a concentrated (substantially saturated) aqueous iodine solution which is passed through the iodinated resin bed to recharge the bed with bound iodine. The bed of iodine crystals is connected in parallel with the iodinated resin bed and is activated periodically (e.g., by timer, by measured flow of water, or by iodine residual level) to recharge the bed. Novelty resides in the capability of inexpensively and repeatedly regenerating the ion-exchange bed in situ

Evaluation of Oil Extraction on Corn Dry-Milling Byproducts in Growing and Finishing Cattle Diets

Dry-milling ethanol plants produce distillers grains (DG) and condensed distillers solubles (CDS). Before thin stillage is evaporated to CDS, corn oil is removed via centrifugation, producing de-oiled CDS. Depending on plant availability, CDS can be marketed or combined with DG to produce de-oiled distillers grains plus solubles (DGS). Currently, there are no data available on animal performance when corn oil is removed via centrifugation of the solubles stream. Therefore, two finishing experiments, a metabolism experiment, and a growing experiment were conducted to evaluate the effects of corn oil removal on cattle performance, carcass characteristics, and the effects on nutrient digestibility. Oil concentration had no effect on DMI, ADG, G:F, and carcass characteristics in finishing cattle fed de-oiled or normal DGS or CDS. Regardless of oil concentration, steers fed DGS or CDS had greater ADG and were more efficient than the corn-based control. Diets containing normal CDS had greater fat digestibility compared to de-oiled CDS, while there was no difference for DGS. The growing experiment suggested that there were no differences in ending BW, DMI, or ADG for the main effects of oil concentration. At lower concentration of dietary CDS, G:F improved 13.6% for normal CDS compared to de-oiled CDS. However, when CDS increased to 40% inclusion, G:F differed by only 1% which could be a result of hindered fiber digestion for normal CDS. In finishing diets, oil removal via centrifugation had no effect on animal performance or carcass characteristics. However, in growing trials, normal CDS fed at low inclusions resulted in improved G:F compared to de-oiled CDS with no difference observed at greater inclusions. Advisors: Galen E. Erickson and Terry J. Klopfenstei

Evaluation of Oil Extraction on Corn Dry-Milling Byproducts in Growing and Finishing Cattle Diets

Dry-milling ethanol plants produce distillers grains (DG) and condensed distillers solubles (CDS). Before thin stillage is evaporated to CDS, corn oil is removed via centrifugation, producing de-oiled CDS. Depending on plant availability, CDS can be marketed or combined with DG to produce de-oiled distillers grains plus solubles (DGS). Currently, there are no data available on animal performance when corn oil is removed via centrifugation of the solubles stream. Therefore, two finishing experiments, a metabolism experiment, and a growing experiment were conducted to evaluate the effects of corn oil removal on cattle performance, carcass characteristics, and the effects on nutrient digestibility. Oil concentration had no effect on DMI, ADG, G:F, and carcass characteristics in finishing cattle fed de-oiled or normal DGS or CDS. Regardless of oil concentration, steers fed DGS or CDS had greater ADG and were more efficient than the corn-based control. Diets containing normal CDS had greater fat digestibility compared to de-oiled CDS, while there was no difference for DGS. The growing experiment suggested that there were no differences in ending BW, DMI, or ADG for the main effects of oil concentration. At lower concentration of dietary CDS, G:F improved 13.6% for normal CDS compared to de-oiled CDS. However, when CDS increased to 40% inclusion, G:F differed by only 1% which could be a result of hindered fiber digestion for normal CDS. In finishing diets, oil removal via centrifugation had no effect on animal performance or carcass characteristics. However, in growing trials, normal CDS fed at low inclusions resulted in improved G:F compared to de-oiled CDS with no difference observed at greater inclusions. Advisors: Galen E. Erickson and Terry J. Klopfenstei

On the state space geometry of the Kuramoto-Sivashinsky flow in a periodic domain

The continuous and discrete symmetries of the Kuramoto-Sivashinsky system restricted to a spatially periodic domain play a prominent role in shaping the invariant sets of its chaotic dynamics. The continuous spatial translation symmetry leads to relative equilibrium (traveling wave) and relative periodic orbit (modulated traveling wave) solutions. The discrete symmetries lead to existence of equilibrium and periodic orbit solutions, induce decomposition of state space into invariant subspaces, and enforce certain structurally stable heteroclinic connections between equilibria. We show, on the example of a particular small-cell Kuramoto-Sivashinsky system, how the geometry of its dynamical state space is organized by a rigid `cage' built by heteroclinic connections between equilibria, and demonstrate the preponderance of unstable relative periodic orbits and their likely role as the skeleton underpinning spatiotemporal turbulence in systems with continuous symmetries. We also offer novel visualizations of the high-dimensional Kuramoto-Sivashinsky state space flow through projections onto low-dimensional, PDE representation independent, dynamically invariant intrinsic coordinate frames, as well as in terms of the physical, symmetry invariant energy transfer rates.Comment: 31 pages, 17 figures; added references, corrected typos. Due to file size restrictions some figures in this preprint are of low quality. A high quality copy may be obtained from http://www.cns.gatech.edu/~predrag/papers/preprints.html#rp

A mathematical expression for depth-light curves of therapeutic proton beams in a quenching scintillator

Purpose: Recently, there has been increasing interest in the development of scintillator-based detectors for the measurement of depth-dose curves of therapeutic proton beams1 . These detectors allow the measurement of single beam parameters such as the proton range or the reconstruction of the full three-dimensional dose distribution. Thus, scintillation detectors could play an important role in beam quality assurance, on-line beam monitoring, and proton imaging. However, the light output of the scintillator as a function of dose deposition is subject to quenching effects due to the high specific energy loss of incident protons, particularly in the Bragg peak. The aim of this work is to develop a model that describes the percent depth-light (PDL) curve in a quenching scintillator and allow the extraction of information about the beam range and the strength of the quenching. Methods: A mathematical expression of a depth-light curve, derived from a combination of Birks’ law2 and Bortfeld’s Bragg curve3 that is termed a “quenched Bragg” curve, is presented. The model is validated against simulation and measurement. Results: A fit of the quenched Bragg model to simulated depth-light curves in a polystyrenebased scintillator shows good agreement between the two, with a maximum deviation of 2.5% at the Bragg peak. The differences are larger behind the Bragg peak and in the dose build-up region. In the same simulation, the difference between the reconstructed range and the reference proton range is found to be always smaller than 0.16 mm. The comparison with measured data shows that the fitted beam range agrees with the reference range within their respective uncertainties. Conclusions: The quenched Bragg model is, therefore, an accurate tool for the range measurement from quenched depth-dose curves. Moreover, it allows the reconstruction of the beam energy spread, the particle fluence and the magnitude of the quenching effect from a measured depth-light curve

EVALUATION OF ALPHA AMYLASE CONTAINING CORN ON FINISHING CATTLE PERFORMANCE AND DIGESTIBILTY

One digestion and four finishing trials were conducted to evaluate the effect of a new corn hybrid containing an α-amylase trait, Syngenta Enogen Feed Corn (SYT-EFC) on site and extent of digestion, ruminal fermentation parameters, and feedlot performance. Experiments utilized corn containing the enzymatic gene compared to controls, the near isoline parental corn (NEG) or commercially available corn grain (CON), processed as dry-rolled corn (DRC) or high moisture corn (HMC) in diets with dry [distillers grains plus solubles (DGS)] or wet (Sweet Bran) milling byproducts. The corn grain of the experimental diets were fed as the sole grain source, comprising 100% of the concentrate in the diet. Cattle fed SYT-EFC, processed as DRC with Sweet Bran had increased G:F resulting in feeding values ranging from 103 to 116% of CON or NEG. Steers fed SYT-EFC, processed as DRC with DGS had increased G:F resulting in feeding values ranging from 101 to 107% of CON or 105% of NEG. However, when processed as HMC, feeding SYT-EFC resulted in 96 and 102% that of NEG when fed with Sweet Bran or DGS, respectively. Marbling and 12th rib fat thickness data were mixed among trials with being increased in cattle fed SYT-EFC or observing no detectable difference among treatments. Cattle fed SYT-EFC had greater postruminal starch digestibility compared to NEG resulting in a 2.2 and 6.3% increase in total tract starch digestibility in DGS and Sweet Bran diets, respectively. Overall, feeding corn containing an α-amylase trait as DRC would suggest a slight improvement in feed efficiency. Advisors: James C. MacDonald and Galen E. Erickso

When the Crp Ends: A Look at Production Alternatives for Highly Erodible Land in Southern Iowa

This report examines the potential use of land currently under CRP contract in a three-county region in southern Iowa. The objectives are twofold: first, to inventory or assess the productivity and ownership characteristics of CRP land in this region and, second, to predict the possible use for these land resources should the CRP cease to exist. In particular, we are concerned with the impact that changing economic conditions, agricultural policy, and technology might have on this transition. The broader consequences of CRP termination in terms of rural economic activity or environmental quality in the region will be examined indirectly, reflected primarily in terms of changes in farm income, land use, and potential rates of soil erosion.