EVALUATION OF A COUNTER-ROTATING ELECTRIC DUCTED FAN

The research and analysis presented in this study quantifies the benefits of a dual-stage counter-rotating electric ducted fan (EDF) that is optimized for high-speed operations. A thrust increase of 29% over a single rotor with the same frontal area was demonstrated. A custom thrust stand was developed to obtain these results and leave in place a capability to test future multi-stage EDF concepts. Commercial off-the-shelf components were modified to accommodate the proposed study. In addition, 3D scanning and reverse engineering techniques to create the necessary CAD models for computations studies were developed, which in turn allows for validation of the proposed EDF performance using three-dimensional fluid modeling software.Outstanding ThesisCivilian, Department of the NavyApproved for public release. Distribution is unlimited

Investigation and development of techniques for the characterisation of the synthetic/biological interface

The purpose of this study is to increase our knowledge of the nature of the surface properties of polymeric materials and improve our understanding of how these factors influence the deposition of proteins to form a reactive biological/synthetic interface. A number of surface analytical techniques were identified as being of potential benefit to this investigation and included in a multidisciplinary research program. Cell adhesion in culture was the primary biological sensor of surface properties, and it showed that the cell response to different materials can be modified by adhesion promoting protein layers: cell adhesion is a protein-mediated event. A range of surface rugosity can be produced on polystyrene, and the results presented here show that surface rugosity does not play a major role in determining a material's cell adhesiveness. Contact angle measurements showed that surface energy (specifically the polar fraction) is important in promoting cell spreading on surfaces. The immunogold labelling technique indicated that there were small, but noticeable differences, between the distribution of proteins on a range of surfaces. This study has shown that surface analysis techniques have different sensitivities in terms of detection limits and depth probed, and these are important in determining the usefulness of the information obtained. The techniques provide information on differing aspects of the biological/synthetic interface, and the consequence of this is that a range of techniques is needed in any full study of such a complex field as the biomaterials area

Systems and methods for delivering dissolved gases into force-main and gravity sewers

Disclosed are systems and methods for dissolving gases into a fluid that is passing through a force-main and gravity sewer system. The system includes a dissolution tank having a pressure vessel for containing a liquid and for providing a regulated gas head space above the liquid, an inlet that permits passage of wastewater into the gas head space, and an outlet that permits passage of treated wastewater out of the pressure vessel. The system also includes a gas source in communication with the pressure vessel; a pump for supplying wastewater from a force-main or sewer system sump into the pressure vessel under conditions effective to dissolve oxygen gas in the wastewater; and a discharge device in communication with the outlet of the dissolution tank assembly for discharging treated wastewater

Oil recovery through deemulsification research : separation of water from emulsified oil

In an effort to improve the environment, there is a need to recover and reuse the oil and water components of lubricating emulsions used in copper drawing and rolling processes. The Freeport-McMoRan Copper and Gold Inc. copper rod mill located in El Paso, TX was chosen as the site location for this project. It is one of the largest rolling and drawing operation facilities in the world, and it meets the established criteria set by Project ORDER. A large facility generates an average of 8,400 gallons of spent lubricant per day. The WERC emulsion sample contains 98 v% water and 2 v% lubricating oil and contains metal debris that would negatively impact water quality if it were discharged into surface waters. Oil and water are valuable resources and their maximum recoveries are desired. Project ORDER successfully recovers more than 90 v% of the water and essentially all of the oil. The recovered water could be recycled for fresh lubricant production within the facility, eliminating almost all water discharge and reducing water intake. The recovered oil will be sent to oil recyclers, lowering discharge expenses. Project ORDER has carefully evaluated several water recovery, oil recovery, and metal recovery technologies to design the commercial process. The first processing step of Project ORDER is an ultrafiltration (UF) membrane that recovers 90 v% of the water in the spent emulsion sample. As water permeates the membrane, the concentration of oil in the emulsion increases from about 2 v% to 30 v%. The second processing step removes essentially all of the water from the UF concentrate using an evaporator, which operates by passing low pressure steam through a jacketed, agitated vessel. The third processing step removes metal debris from the oil using a depth filter. The fourth processing step utilizes a reverse osmosis (RO) membrane to purify the UF permeate water for recycle. The fifth processing step reduces the amount of waste from the RO reject using an evaporator, which also operates by passing low pressure steam through a jacketed, agitated vessel. The evaporator removes essentially all of the water in the RO reject and the remaining waste is sent for disposal. The evaporated water from both evaporation units is condensed and combined with the RO permeate to be recycled. Based on a spent emulsion production rate of 8,400 gal/day, it costs $793, 000 per year for current disposal by incineration. For Project ORDER the fixed capital investment is$899,000, the yearly operating cost is $528,000, and the net present worth is$413,000 with a 24% discounted rate of return. After the initial investment is recovered, Project ORDER results in a net savings of $265,000 per year. This project is a promising process to achieve all the goals of Task 5. It produces oil with less than 3% water content, produces maximum water yield, minimizes waste solution, avoids the use of harmful materials and is cost and energy efficient. The health and safety of all individuals involved and the environmental impact of Project ORDER is of utmost importance throughout the construction and life of the project. The facility will ensure that all processes will comply with regulations outlined by the Environmental Protection Agency (EPA), Occupational Safety and Health Administration (OSHA), the Resource Conservation and Recovery Act (RCRA), and Texas State and El Paso County regulations. All operations and company procedures will comply with The Emergency Planning and Community Right-to-Know Act of 1986. The following report provides a detailed proposal for an oil and water recovery system, including experimental research results, process optimization, full-scale design, economic analysis, and environmental, health and safety considerations

Spatiotemporal variability of modern precipitation δ18O in the central Andes and implications for paleoclimate and paleoaltimetry estimates

Understanding the patterns of rainfall isotopic composition in the central Andes is hindered by sparse observations. Despite limited observational data, stable isotope tracers have been commonly used to constrain modern‐to‐ancient Andean atmospheric processes, as well as to reconstruct paleoclimate and paleoaltimetry histories. Here, we present isotopic compositions of precipitation (δ18Op and δDp) from 11 micrometeorological stations located throughout the Bolivian Altiplano and along its eastern flank at ~21.5°S. We collected and isotopically analyzed 293 monthly bulk precipitation samples (August 2008 to April 2013). δ18Op values ranged from −28.0‰ to 9.6‰, with prominent seasonal cycles expressed at all stations. We observed a strong relationship between the δ18Op and elevation, though it varies widely in time and space. Constraints on air sourcing estimated from atmospheric back trajectory calculations indicate that continental‐scale climate dynamics control the interannual variability in δ18Op, with upwind precipitation anomalies having the largest effect. The impact of precipitation anomalies in distant air source regions to the central Andes is in turn modulated by the Bolivian High. The importance of the Bolivian High is most clearly observed on the southern Bolivian Altiplano. However, monthly variability among Altiplano stations can exceed 10‰ in δ18Op on the plateau and cannot be explained by elevation or source variability, indicating a nontrivial role for local scale effects on short timescales. The strong influence of atmospheric circulation on central Andean δ18Op requires that paleoclimate and paleoaltimetry studies consider the role of South American atmospheric paleocirculation in their interpretation of stable isotopic values as proxies.Key PointsFive‐year record of central Andes precipitation isotopic compositionPrecipitation isotopes are elevation dependent, but vary in space and timePrecipitation isotope variability is related to large‐scale climate dynamicsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111974/1/jgrd52161.pd

Morphological identification of Bighead Carp, Silver Carp, and Grass Carp eggs using random forests machine learning classification

Visual identification of fish eggs is difficult and unreliable due to a lack of information on the morphological egg characteristics of many species. We used random forests machine learning to predict the identity of genetically identified Bighead Carp Hypophthalmichthys nobilis, Grass Carp Ctenopharyngodon idella, and Silver Carp H. molitrix eggs based on egg morphometric and environmental characteristics. Family, genus, and species taxonomic-level random forests models were explored to assess the performance and accuracy of the predictor variables. The egg characteristics of Bighead Carp, Grass Carp, and Silver Carp were similar, and they were difficult to distinguish from one another. When combined into a single invasive carp class, the random forests models were ≥ 97% accurate at identifying invasive carp eggs, with a ≤5% false positive rate. Egg membrane diameter was the most important predictive variable, but the addition of ten other variables resulted in a 98% success rate for identifying invasive carp eggs from 26 other upper Mississippi River basin species. Our results revealed that a combination of morphometric and environmental measurements can be used to identify invasive carp eggs. Similar machine learning approaches could be used to identify the eggs of other fishes. These results will help managers more easily and quickly assess invasive carp reproduction

Urban Stream Burial Increases Watershed-Scale Nitrate Export

Nitrogen (N) uptake in streams is an important ecosystem service that reduces nutrient loading to downstream ecosystems. Here we synthesize studies that investigated the effects of urban stream burial on N-uptake in two metropolitan areas and use simulation modeling to scale our measurements to the broader watershed scale. We report that nitrate travels on average 18 times farther downstream in buried than in open streams before being removed from the water column, indicating that burial substantially reduces N uptake in streams. Simulation modeling suggests that as burial expands throughout a river network, N uptake rates increase in the remaining open reaches which somewhat offsets reduced N uptake in buried reaches. This is particularly true at low levels of stream burial. At higher levels of stream burial, however, open reaches become rare and cumulative N uptake across all open reaches in the watershed rapidly declines. As a result, watershed-scale N export increases slowly at low levels of stream burial, after which increases in export become more pronounced. Stream burial in the lower, more urbanized portions of the watershed had a greater effect on N export than an equivalent amount of stream burial in the upper watershed. We suggest that stream daylighting (i.e., uncovering buried streams) can increase watershed-scale N retention

Evidence of Strong Stabilizing Effects on the Evolution of Boreoeutherian (Mammalia) Dental Proportions

The dentition is an extremely important organ in mammals with variation in timing and sequence of eruption, crown morphology, and tooth size enabling a range of behavioral, dietary, and functional adaptations across the class. Within this suite of variable mammalian dental phenotypes, relative sizes of teeth reflect variation in the underlying genetic and developmental mechanisms. Two ratios of postcanine tooth lengths capture the relative size of premolars to molars (premolar–molar module, PMM), and among the three molars (molar module component, MMC), and are known to be heritable, independent of body size, and to vary significantly across primates. Here, we explore how these dental traits vary across mammals more broadly, focusing on terrestrial taxa in the clade of Boreoeutheria (Euarchontoglires and Laurasiatheria). We measured the postcanine teeth of N = 1,523 boreoeutherian mammals spanning six orders, 14 families, 36 genera, and 49 species to test hypotheses about associations between dental proportions and phylogenetic relatedness, diet, and life history in mammals. Boreoeutherian postcanine dental proportions sampled in this study carry conserved phylogenetic signal and are not associated with variation in diet. The incorporation of paleontological data provides further evidence that dental proportions may be slower to change than is dietary specialization. These results have implications for our understanding of dental variation and dietary adaptation in mammal