A method for the analysis of the benefits and costs for aeronautical research and technology

A relatively simple, consistent, and reasonable methodology for performing cost-benefit analyses which can be used to guide, justify, and explain investments in aeronautical research and technology is presented. The elements of this methodology (labeled ABC-ART for the Analysis of the Benefits and Costs of Aeronautical Research and Technology) include estimation of aircraft markets; manufacturer costs and return on investment versus aircraft price; airline costs and return on investment versus aircraft price and passenger yield; and potential system benefits--fuel savings, cost savings, and noise reduction. The application of this methodology is explained using the introduction of an advanced turboprop powered transport aircraft in the medium range market in 1978 as an example

Optimizing Solvent Blends for a Quinary System

The Department of Polymer Engineering had received a grant from the Keck foundation to produce a process in which hundreds of copolymers can be formulated, synthesized, analyzed and then extrapolated to produce the optimal polymer for the desired material property. This process involves synthesizing approximately fifty polymers in a custom apparatus, none of which necessarily have the same monomer components. This leads to issue of which solvent or blend of solvents to use that would sufficiently dissolve both monomers and the resulting copolymer. If the monomers are not completely dissolved, a homogenous reaction will be impossible and if the copolymer is not soluble; it will precipitate out before the reaction is complete. My project is designing a computer program that will use the Hansen Solubility Parameters to predict the optimal blend of solvents that will sufficiently dissolve the monomers and resulting copolymers. The program will be written in C++ and executed in a Linux environment. The Hansen Solubility Parameters are derived purely from experimental data and are yet to have a strong theoretical basis. Despite this limitation, it is believed that these parameters will be sufficient for the needs of this project. The Hansen Solubility Parameters (HSP) describe monomers, polymers , and solvents as three dimensional shapes. For the sake of clarity one may consider these shapes as spheres, the center of which is described by HSP, and the radius is defined by the molar volume of the substance. All points that lie within these spheres describe a potential solvent for the given substance. The process of this optimization can take a human several minutes to complete, while a computer can accomplish the same task in fractions of a second. When designing a high throughput system, it is impractical to be spending multiple hours deciding which solvents to use for fifty polymer systems per iteration. This will eliminate an experimental bottleneck for the overall projec

3014 Meadowbridge Rd: A Community-Engaged Opportunity-Based Re-investment Action Plan

This plan is an asset-based community response for 7th Street Memorial Baptist Church CDC as a way to revitalize and uplift the Six Points neighborhood of Highland Park. This plan was designed to provide a template for community engagement that would reintroduce a legacy of service to the community while partnering with other community assets to reinvest into the community. The primary action that makes this a prime engagement opportunity is the restoration of 7th Street Memorial Baptist Church location at 3014 Meadowbridge Rd. Treating the building as an asset for the community and not only the church has enabled the future partnerships to be opportunity based. These partnerships will address: Education, Health and Housing needs of the community. With an abundance of empty buildings along the storefront of this historic neighborhood, this plan will make use of the most important assets in the neighborhood: the people. Utilizing best practices from all over the United States, this plan contains recommendations that bring together community assets to form partnerships that will address some of the barriers that led to this neighborhood’s current state of disinvestment. These recommendations address future partnerships that address long term employment, improved community engagement, improved higher education faculties among its student population and improved food access from and on a community level

Optimizing Solvent Blends for a Quinary System

The Department of Polymer Engineering had received a grant from the Keck foundation to produce a process in which hundreds of copolymers can be formulated, synthesized, analyzed and then extrapolated to produce the optimal polymer for the desired material property. This process involves synthesizing approximately fifty polymers in a custom apparatus, none of which necessarily have the same monomer components. This leads to issue of which solvent or blend of solvents to use that would sufficiently dissolve both monomers and the resulting copolymer. If the monomers are not completely dissolved, a homogenous reaction will be impossible and if the copolymer is not soluble; it will precipitate out before the reaction is complete. My project is designing a computer program that will use the Hansen Solubility Parameters to predict the optimal blend of solvents that will sufficiently dissolve the monomers and resulting copolymers. The program will be written in C++ and executed in a Linux environment. The Hansen Solubility Parameters are derived purely from experimental data and are yet to have a strong theoretical basis. Despite this limitation, it is believed that these parameters will be sufficient for the needs of this project. The Hansen Solubility Parameters (HSP) describe monomers, polymers , and solvents as three dimensional shapes. For the sake of clarity one may consider these shapes as spheres, the center of which is described by HSP, and the radius is defined by the molar volume of the substance. All points that lie within these spheres describe a potential solvent for the given substance. The process of this optimization can take a human several minutes to complete, while a computer can accomplish the same task in fractions of a second. When designing a high throughput system, it is impractical to be spending multiple hours deciding which solvents to use for fifty polymer systems per iteration. This will eliminate an experimental bottleneck for the overall projec

Viscoplasticity and large-scale chain relaxation in glassy-polymeric strain hardening

A simple theory for glassy polymeric mechanical response which accounts for large scale chain relaxation is presented. It captures the crossover from perfect-plastic response to strong strain hardening as the degree of polymerization $N$ increases, without invoking entanglements. By relating hardening to interactions on the scale of monomers and chain segments, we correctly predict its magnitude. Strain activated relaxation arising from the need to maintain constant chain contour length reduces the $N$ dependence of the characteristic relaxation time by a factor $\sim \dot\epsilon N$ during active deformation at strain rate $\dot\epsilon$. This prediction is consistent with results from recent experiments and simulations, and we suggest how it may be further tested experimentally.Comment: The theoretical treatment of the mechanical response has been significantly revised, and the arguments for coherent relaxation during active deformation made more transparen

Strain Hardening in Polymer Glasses: Limitations of Network Models

Simulations are used to examine the microscopic origins of strain hardening in polymer glasses. While traditional entropic network models can be fit to the total stress, their underlying assumptions are inconsistent with simulation results. There is a substantial energetic contribution to the stress that rises rapidly as segments between entanglements are pulled taut. The thermal component of stress is less sensitive to entanglements, mostly irreversible, and directly related to the rate of local plastic arrangements. Entangled and unentangled chains show the same strain hardening when plotted against the microscopic chain orientation rather than the macroscopic strain.Comment: 4 pages, 3 figure

Conceptual analysis of a lunar base transportation system

Important to the planning for a lunar base is the development of transportation requirements for the establishment and maintenance of that base. This was accomplished as part of a lunar base systems assessment study conducted by the NASA Langley Research Center in conjunction with the NASA Johnson Space Center. Lunar base parameters are presented using a baseline lunar facility concept and timeline of developmental phases. Masses for habitation and scientific modules, power systems, life support systems, and thermal control systems were generated, assuming space station technology as a starting point. The masses were manifested by grouping various systems into cargo missions and interspersing manned flights consistent with construction and base maintenance timelines. A computer program that sizes the orbital transfer vehicles (OTV's), lunar landers, lunar ascenders, and the manned capsules was developed. This program consists of an interative technique to solve the rocket equation successively for each velocity correction (delta V) in a mission. The delta V values reflect integrated trajectory values and include gravity losses. As the program computed fuel masses, it matched structural masses from General Dynamics' modular space-based OTV design. Variables in the study included the operation mode (i.e., expendable vs. reusable and single-stage vs. two-stage OTV's), cryogenic specific impulse, reflecting different levels of engine technology, and aerobraking vs. all-propulsive return to Earth orbit. The use of lunar-derived oxygen was also examined for its general impact. For each combination of factors, the low-Earth orbit (LEO) stack masses and Earth-to-orbit (ETO) lift requirements are summarized by individual mission and totaled for the developmental phase. In addition to these discrete data, trends in the variation of study parameters are presented

A five year outbreak of methicillin-susceptible Staphylococcus aureus phage type 53,85 in a regional neonatal unit

We identified a 5-year outbreak of a methicillin-susceptible Staphylococcus aureus (MSSA) strain, affecting 202 babies on a neonatal unit, by routine weekly phage typing all S. aureus isolates. Multiple staged control measures including strict emphasis on hand hygiene, environmental and staff surveillance sampling, and application of topical hexachlorophane powder failed to end the outbreak. S. aureus PT 53,85 (SA5385) was found on opened packs of Stomahesive®, used as a neonatal skin protectant. Only following the implementation of aseptic handling of Stomahesive®, and the use of topical mupirocin for staff nasal carriers of SA5385, and for babies colonized or infected with S. aureus, did the isolation rate of SA5385 decline. DNA fingerprinting indicated that [gt-or-equal, slanted]95% of SA5385 isolates were clonal. In vitro death rates of SA5385 on Stomahesive® with human serum were significantly lower than on Stomahesive® alone (P = 0·04), and on cotton sheet with serum (P = 0·04), highlighting the potential of this material as a survival niche. Phage typing remains a valuable, inexpensive and simple method for monitoring nosocomial MSSA infection

Integrating Time Into Family Business Research: Using Random Coefficient Modeling to Examine Temporal Influences on Family Firm Ambidexterity

Organizational ambidexterity refers to a firm’s ability to pursue both exploitation and exploration orientations. Despite research that suggests ambidexterity is a critical phenomenon in family firms, few studies directly examine the role of ambidexterity over time in family business. This study examines how family firm ambidexterity changes over time as a result of temporal-, firm-, and industry-level factors. We find that family firm ambidexterity is stable over time, punctuated by dramatic changes. We also find that the level of innovation required to compete in an industry is a predictor of changes in exploration versus exploitation over time among family firms.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline