A trajectory generation and system characterization model for cislunar low-thrust spacecraft. Volume 2: Technical manual

The documentation of the Trajectory Generation and System Characterization Model for the Cislunar Low-Thrust Spacecraft is presented in Technical and User's Manuals. The system characteristics and trajectories of low thrust nuclear electric propulsion spacecraft can be generated through the use of multiple system technology models coupled with a high fidelity trajectory generation routine. The Earth to Moon trajectories utilize near Earth orbital plane alignment, midcourse control dependent upon the spacecraft's Jacobian constant, and capture to target orbit utilizing velocity matching algorithms. The trajectory generation is performed in a perturbed two-body equinoctial formulation and the restricted three-body formulation. A single control is determined by the user for the interactive midcourse portion of the trajectory. The full spacecraft system characteristics and trajectory are provided as output

The Effects of Sex-Sorted Semen on Southern Dairy Farms

This paper examines the impact of sex-sorted semen adoption on dairy farm level economics. Representative dairies are used to simulate the financial impacts of moving to this new technology. Key economic, financial and herd dynamics will be compared among dairies to show how the uses of sex-sorted semen will affect dairy farms. All seven of the representative dairies that were analyzed sold surplus replacement heifers using sex-sorted semen. The increase use of sex-sorted semen can have very positive impacts on dairies throughout the Southern United States.Dairy production, sex sorted semen, production economics, scenario analysis, Agribusiness, Farm Management, Livestock Production/Industries, Production Economics,

Investigation of the Influence of Molecular Structure at Interfaces in Polymer Photovoltaic Devices.

Organic photovoltaic devices embody the promise of inexpensive renewable energy. However, before these devices can become commercially successful a stronger understanding of the relationships between material structure, properties and device performance must be built. Interfaces within polymer photovoltaic devices are sites of processes critical to effective device function and are thus the focal point for ongoing research. We systematically investigated the effect of placing molecular spacers at the donor-acceptor interface. As we increased the thickness of the spacer layer we observed suppressed charge transfer, reduced dark current and reduced polaron binding which contributed to a decrease in current density and an increase in open circuit voltage. This result guides the design of materials which seek to mitigate the interfacial distance dependent trade-offs between charge transfer and recombination in order to improve device performance. We also investigated the influence of the molecular structure of the electrode-active layer interface. We found that insulating interfacial layers ensure diode rectification by breaking percolative-active material contact between non-selective electrodes. We also found that strong active layer-electrode interaction leads to charge blocking phase separation in the devices which deleteriously effects performance. This unwanted phase separation can be avoided by inserting a non-interacting interlayer. We also observed that acid- or base-like moieties can be used to modify the work function of ITO in order to achieve good electrical contact with the active layers of a device. These results provide molecular design guidelines for the fabrication of materials for the electrode interface of high performance devices. Besides the interface issues, the low charge carrier mobility of conjugated polymers (CPs) intrinsically limits the thickness, absorption, and performance of photovoltaic devices. We made aligned poly(3-hexylthiophene) films with an epitaxially directing additive and an off-center spincasting technique in order to take advantage of their anisotropic charge carrier mobility. These aligned films are applied in novel in-plane devices where the charge transport direction is abutted with the polymer alignment, providing large enhancements in the open circuit voltage. These results motivate the continued pursuit of CP alignment in devices in order to correlate molecular orientation with device performance.PHDMaterials Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107045/1/bilbydav_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/107045/2/bilbydav_2.pd

Exploring the response of a resistive soot sensor to AC electric excitation

The resistive particulate matter sensor is a simple device that transduces the presence of soot through impedance change across inter-digital electrodes (IDEs). We investigate the information provided by impedance spectroscopy over the frequency range from 100 Hz to 10 kHz for two purposes. The first is to investigate the opportunities for an improved sensor response to particulate matter (PM), based on the additional information provided by the measurement of both the in-phase (resistive) and out-of-phase (capacitive) components of the change in impedance over this frequency range as compared to DC resistance measurement only. Secondly, the origin of the capacitive response of the device is investigated from the perspective that soot on the device is in the form of bendable dendrites that grow in three dimensions. An IDE structure with the housing acting as an additional suspended electrode for introducing a controllable vertical electric field component has been used for this purpose. The formation of dipoles, due to bending of the charged dendrites, is found to be the source of the capacitive response. Simulation of electrostatic soot deposition reinforces dendritic self-assembly mechanisms, driven by charged particle trajectories along electric field lines. Optical microscopy confirms that dendrites growing out of the substrate plane are sensitive to electric and flow forces, bending when force balances are appropriate. We also apply impedance spectroscopy under varying electric field strengths, showing that capacitive response is only observed when conditions are conducive to dendrite bending in response to the applied AC electric fields

Self-Cleaning Micro-Windows for In-Tailpipe Optical Exhaust Gas Measurements

Exhaust gas measurement in the harsh environment of the tailpipe of a combustion engine by optical techniques is a highly robust technique, provided that optical access is maintained in the presence of particulate matter (PM). The considerations are presented for the systematic design of membranes with integrated heaters in SiC-on-Si technology for generating a well-defined lateral temperature profile with peak temperatures above 600 \ub0C. Periodically raising the temperature of the membranes to such a level is demonstrated to keep the surface transparent by oxidation of soot deposits. This paper is about continuous heating of the membrane to a temperature slightly higher than that of the exhaust gas. At such temperatures thermophoretic repulsion of PM allows allows long-term optical measurement in the exhaust without the thermo-mechanical loading by repetitive thermal cycling

Maintaining transparency of a heated MEMs membrane for enabling long-term optical measurements on soot-containing exhaust gas

Ensuring optical transparency over a wide spectral range of a window with a view into the tailpipe of the combustion engine, while it is exposed to the harsh environment of sootcontaining exhaust gas, is an essential pre-requisite for introducing optical techniques for long-term monitoring of automotive emissions. Therefore, a regenerable window composed of an optically transparent polysilicon-carbide membrane with a diameter ranging from 100 \ub5m up to 2000 \ub5m has been fabricated in microelectromechanical systems (MEMS) technology. In the first operating mode, window transparency is periodically restored by pulsed heating of the membrane using an integrated resistor for heating to temperatures that result in oxidation of deposited soot (600–700 \ub0C). In the second mode, the membrane is kept transparent by repelling soot particles using thermophoresis. The same integrated resistor is used to yield a temperature gradient by continuous moderate-temperature heating. Realized devices have been subjected to laboratory soot exposure experiments. Membrane temperatures exceeding 500 \ub0C have been achieved without damage to the membrane. Moreover, heating of membranes to ΔT = 40 \ub0C above gas temperature provides sufficient thermophoretic repulsion to prevent particle deposition and maintain transparency at high soot exposure, while non-heated identical membranes on the same die and at the same exposure are heavily contaminated

Work Function Modification via Combined Charge‐Based Through‐Space Interaction and Surface Interaction

Work function modification of electrodes is an important factor to achieve high performance in organic electronics. However, a clear explanation of the origin of work function modification has remained elusive. Here, it is investigated how the work function of electrodes is affected by the charge‐based through‐space interaction with the well‐known surface interaction. The studies reveal that the formation of a surface dipole leads to a work function shift, even when the work function modifying layer and substrate are separated. A work function shift is also demonstrated by electrophoretic deposition of ionic polyelectrolytes while the same polyelectrolytes do not cause any work function shift when they are spin cast. More noteworthy is that a neutral (nonionic) polymer which has no specific surface‐interacting functional groups can induce work function shift of its substrate by a charge‐based through‐space interaction when deposited by electrospraying. These results provide a more comprehensive understanding of work function modification and motivate the design and selection of a wide range of effective work function modifying layers for organic electronics.Work function modification of indium tin oxide (ITO) by thin‐layer polymer coating is investigated with a set of representative polyelectrolytes. The studies reveal that while direct surface interaction is the major factor affecting work function modification, charge‐based through‐space interaction has also a significant effect on modifying the work function of electrodes by building opposite charges on ITO.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145536/1/admi201800471-sup-0001-S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145536/2/admi201800471.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145536/3/admi201800471_am.pd

Exploring Alternative Terrain in the Rehabilitation and Treatment of Offenders: Findings from a Prison-based Music Project

The arts in prison settings have provided an alternative or complimentary component to rehabilitation. Despite increased interest, studies capturing the voice of offenders participating in projects and the long-term impact are limited. Data from semistructured interviews with 18 men who had taken part in a music-based project while incarcerated, including one group of five participants who were tracked for 18 months with supplemented data from correctional staff and official documentation, is presented. Participants of the art-based projects comment on changes they believe to have derived from participating in the project, particularly relating to emotions, self-esteem, self-confidence, communication and social skills. An exoffender sample of participants reported that participation in art projects provide experiences that promote beneficial skills that have been useful for post prison life

Research, Monitoring, and Evaluation of Fish and Wildlife Restoration Projects in the Columbia River Basin: Lessons Learned and Suggestions for Large- Scale Monitoring Programs

El ano 2006 representa en dos sentidos una fecha critica para la cuenca del Rio Columbia y para los esfuerzos de recuperacion del salmon y la trucha arcoiris en la region Pacifico Noroeste: el 25 aniversario de la creacion del Consejo para la Conservacion y Poder del Noroeste y el 10 degree aniversario de la enmienda al Acto de Poder del Noroeste, que formaliza el arbitraje cientifico del Programa de Pesca y Vida Silvestre de dicho consejo, asi como de sus proyectos individuales. Durante la ultima decada, los autores del presente trabajo fungieron como arbitros de estos proyectos. Los esfuerzos de recuperacion en el Rio Columbia constituyen una iniciativa muy importante en cuanto a la rehabilitacion de pesquerias y ecosistemas. En este articulo se examinan algunas lecciones aprendidas durante el proceso de revision de investigacion, monitoreo y evaluacion de proyectos y su repercusion sobre el avance del conocimiento (manejo adaptativo) en el Programa de Pesca y Vida Silvestre de la Cuenca del Rio Columbia, uno de los programas de recuperacion mas ambiciosos y de mas largo plazo en los Estados Unidos de Norteamerica.The year 2006 marked two milestones in the Columbia River Basin and the Pacific Northwest region's efforts to rebuild its once great salmon and steelhead runs -- the 25th anniversary of the creation of the Northwest Power and Conservation Council and the 10th anniversary of an amendment to the Northwest Power Act that formalized scientific peer review of the council's Fish and Wildlife Program and its varied individual projects. The authors of this article served as peer reviewers in the last decade. Restoration efforts in the Columbia River constitute a massive long-term attempt at fisheries and ecosystem restoration. In this article we examine some of the lessons we learned in reviewing the research, monitoring, and evaluation efforts of projects and their effects on advancing knowledge (i.e., adaptive management) in the Columbia River Basin Fish and Wildlife Program, one of the most ambitious and expensive long-term ecological restoration programs in the United States.Keywords: Restoration, Monitoring, Fishery Management, Columbia River BasinKeywords: Restoration, Monitoring, Fishery Management, Columbia River Basi