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To fabricate heavier beef carcasses alternative fabrication methods for the chuck and round were evaluated. Carcasses (364 to 386 kg) were selected for forequarter (n=32) and hindquarter (n=30) evaluation. Forequarter breaks at the third/fourth and fifth/sixth rib, with the rib beginning at the sixth/seventh rib, were processed into whole muscles. Bone, lean trim, fat, and muscles were weighed and Longissimus dorsi (LD) steaks were subject to Warner-Bratzler Shear Force (WBS). Both subprimals had over 60% lean yield and no differences among WBS results (P=0.49, 0.39, respectively). To evaluate effects of modifying the chuck/rib break short rib subprimals (n=20) were aged for 21d post mortem at 2 ˚C. Subprimals (n=10) were weighed whole (kg) and each rib (ribs 2-12) separated. Each ribs bone, lean, and fat were separated and weighed (g). Ten short rib subprimals were sliced into 6 mm slices, cooked on an electric skillet, and served to a trained sensory panel. Ribs 5-7 were similar (PPP < 0.0001). Ribs 6-8 were rated highest for juiciness, and ribs 5 and 11 were least juicy (PBiceps femoris was removed. Extended sirloin caps (n=20) from each carcass were weighed (kg), vacuum packaged, and aged for 25 d at 2˚C. Steaks (2.54 cm) from caps were cut perpendicular (n=10) or parallel (n=10) to muscle fiber direction. Steaks were consumed in a sensory panel and/or subject to WBS evaluation. Steaks from the cranial portion of the cap, regardless of cutting method, had less connective tissue and were more juicy and tender compared to more caudal steaks (P < 0.0001). Steaks cut parallel were less tender (P < 0.0001) compared to perpendicular. With increasing carcass weights, alternative fabrication methods should be considered to add variety to beef cuts. Advisor: Chris R. Calkins

The sedimentary record from Bath Pond, a glacially-derived lake in northeastern Ohio, contains a record of the depositional history of the past twelve thousand years. Correlation of this high-resolution record with archaeological and historical records of human activity indicates that cultural transitions preserved in the archaeological record occur during climatic shifts recorded in the sediment record. Bath Pond is the largest (0.06 km2) of five ponds within Bath Nature Preserve(BNP). This study addresses the following questions: 1) how was Bath Pond formed and was it modified by human activity, 2) can we identify natural and anthropogenic land use changes within the depositional basin of the pond, 3) is Bath Pond similar to other ponds within BNP, and 4) what is the depositional history within Bath Pond for the past 4,000years? Bathymetric mapping of the basin indicates that Bath Pond has a single central basin with a small sub-basin along the western edge of the pond, near an outlet to the North Fork of Bath Creek. Based on geochemical analysis of water samples collected over a one-year period, Bath Pond is most similar to Garden Pond, a small natural pond in the eastern portion of BNP. Additionally, both water chemistry and temperaturerecords indicate that Bath Pond has distinct seasonality. During the last seventy years, land use within the drainage basin of Bath Pond, the majority of which is within BNP, has not changed significantly. However, during the same period, land use in the areasurrounding BNP has transitioned from a predominantly agriculture based land use to a modified residential land use. Additionally, analyses of glacial tills recovered from two terraces surrounding Bath Pond indicate that the pond was once several meters deeperthan at present. A three-meter sediment core was recovered from Bath Pond in September, 2008. This core was analyzed for dry bulk density, percent organic matter, percent carbonate, grain size, elemental composition and biological materials. The core retrieved from Bath Pond records several pre-historic burn events within the area surrounding BNP. These events are correlative with changes in pollen recordedin sediments previously studied from Silver Lake, Logan County, Ohio. The timing and duration of these events, as well as climatic conditions during this time period, coincides with rapid transitions in culture during the Woodland archaeological period in Ohio. These results represent the first geological study of the ponds within BNP and provide a high-resolution interpretation of environmental variation in northeast Ohio.

The deformation and breakup properties of liquid drops and round liquid jets in uniform crossflows were studied computationally, motivated by applications to the behavior of sprays in crossflows found in a variety of power and propulsion systems. The objective of the present investigation was to extend the parameter range of past deformation and breakup studies, by means of numerical computations, to conditions more representative of practical high-pressure spray combustion processes. The time-dependent, incompressible and two-dimensional Navier-Stokes equations were solved on a uniform, staggered grid using the projection method of Chorin (1968) and the Level Set method of Sussman et al. (1994). Numerical simulations of the effect of crossflows on the deformation and breakup of drops and round liquid jets were carried out for the following range of parameters to study the independent effects of four dimensionless variables that fully describe the problem: Weber numbers of 0.1--2,000,000, Ohnesorge numbers of 0.001--100, Reynolds numbers of 12.5--200 and liquid/gas density ratios of 2--infinity (the last by Richardson extrapolation). The present results were in good agreement with existing measurements of deformation and breakup properties of both liquid drops and round liquid jets at large liquid/gas density ratios and with wake and drag properties of spheres and cylinders in crossflows. Similar to past experimental observations, remarkable similarities were observed between the breakup properties of round liquid jets and liquid drops. The liquid/gas density ratio was found to have a relatively small effect on deformation and breakup. Effects of Reynolds number variations were also small for conditions where the drag coefficient is relatively independent of the Reynolds number. As the Stokes flow regime is approached, however, the Weber number (We) required for breakup increases significantly due to increased drag coefficients. At large Ohnesorge number (Oh) conditions, where liquid viscous forces dominate surface tension forces, breakup is best defined in terms of a critical ratio of drag forces to liquid viscous forces, We 1/2/Oh, and plotting We1/2 /Oh vs. 1/Oh yielded breakup regime boundaries that were relatively constant for large Oh and largely independent of other parameters of the flow.

There exists experimental evidence that the dilution of a submerged point source discharge achieved in the radial spreading flow after impingement on a horizontal surface is considerably greater than that predicted for only the submerged jet portion of the flow field. Although previous studies presented data and developed a conceptual model that qualitatively described the experimental results, they do not provide sufficient results to completely understand this phenomenon and disagree on how to model it. In this research, velocity and concentration profiles at various radial distances within the radially spreading flow field were gathered simultaneously with an Acoustic Doppler Velocimeter and an electronic conductivity probe. The experimental setup consisted of a negatively buoyant jet impinging on a submerged plate in a large tank. The purpose was to both identify the deficiencies in the previously proposed model formulation and to perform specific types of experiments that would independently validate the conceptual basis behind the model formulation. Measurements gathered in this study confirmed the existence of a critical flow downstream of the near field mixing zone. By adding a specific downstream control, namely a weir, in the far field zone of the flow, the critical flow control was removed. This resulted in a reduction in the Froude number and the dilution as well, emphasizing the significance of downstream controls on mixing. Experiments involving the submergence of the buoyant jet demonstrated the role of the two layer dynamics on the overall mixing. In the plume case, the upper layer does not contribute to the Froude number or the momentum balance and the experimental results show the dilution to be independent of total depth. Increasing the source momentum increases the influence of the upper layer on the flow dynamics and experiments for this case show that increasing the total depth increases dilution. Numerical model was proposed that is capable of predicting average dilution and average layer thickness at the end of the near field mixing zone and the radial extent of this zone.

An experimental and theoretical study of round buoyant turbulent plumes in still and unstratified environment was conducted, emphasizing self-preserving conditions. The experiments involved downward flowing round negatively-buoyant turbulent plumes created by injecting carbon dioxide and sulfur hexafluoride into still and unstratified air. The mixture fraction and velocity properties were measured using laser-induced iodine fluorescence (LIF) and laser-Doppler velocimetry (LDV), respectively, while the combined mixture fraction/velocity properties were measured using combined LIF/LDV. The present measurements were exploited to evaluate k-$\varepsilon$-g and Reynolds stress models of buoyant turbulent flows, by direct comparisons between model approximations and measurements. In addition, predictions of the models for the self-preserving region of round buoyant turbulent plumes were compared with measurements in order to assess overall model performance. The self-preserving conditions of round buoyant turbulent plumes were observed relatively far from the source under the present test conditions: $\rm (x - x\sb0)/d = 87\sim151$ and $\rm (x - x\sb0)/{\it l}\sb{M} =12\sim43.$ Present measurements yielded distributions of mean mixture fractions and streamwise velocities in the self-preserving region that were up to 40% narrower, with appropriately scaled values near the axis up to 30% larger than earlier measurements in the literature, indicating that the earlier measurements actually involved transitional plumes. Large mixture fraction fluctuations and turbulence mass fluxes were observed in the self-preserving region due to the strong correlation between mixture fraction and velocity fluctuations. However, present measurements of velocity fluctuations and the Reynolds stress were similar to round nonbuoyant turbulent jets. Other properties reported include: probability density functions and temporal power spectral densities of mixture fraction and velocity fluctuations, integral time and length scales, two-point correlations of mixture fractions, and high-order moments of velocities and combined mixture fraction/velocity statistics. In addition, turbulence kinetic energy dissipation, mixture fraction variance dissipation, pressure/strain and pressure/mixture-fraction-fluctuation-gradient correlations were obtained from budget analysis. Evaluations of the widely used k-$\varepsilon$-g turbulence model revealed that while mean properties were predicted reasonably well, there were deficiencies of corresponding turbulence properties. For example, streamwise turbulence and momentum fluxes exhibited countergradient diffusion. In addition, the turbulent Prandtl/Schmidt number, the ratio of the characteristic velocity and mixture fraction time scales and the coefficient of the radial gradient diffusion approximation for the Reynolds stress, all exhibited variations across the flow rather than remaining constant as prescribed by k-$\varepsilon$-g model. Evaluations of the Reynolds stress model also revealed some deficiencies, especially somewhat poorer predictions of mean properties and a need to improve the model for the pressure/mixture-fraction-fluctuation-gradient correlation.