Model-based spacecraft and mission design for the evaluation of technology

In order to meet the future vision of robotic missions, engineers will face intricate mission concepts, new operational approaches, and technologies that have yet to be developed. The concept of smaller, model driven projects helps this transition by including life-cycle cost as part of the decision making process. For example, since planetary exploration missions have cost ceilings and short development periods, heritage flight hardware is utilized. However, conceptual designs that rely solely on heritage technology will result in estimates that may not be truly representative of the actual mission being designed and built. The Laboratory for Spacecraft and Mission Design (LSMD) at the California Institute of Technology is developing integrated concurrent models for mass and cost estimations. The purpose of this project is to quantify the infusion of specific technologies where the data would be useful in guiding technology developments leading up to a mission. This paper introduces the design-to-cost model to determine the implications of various technologies on the spacecraft system in a collaborative engineering environment. In addition, comparisons of the benefits of new or advanced technologies for future deep space missions are examined

Flight Testing of Nap of-the-Earth Unmanned Helicopter Systems

This paper describes recent results from a partnership between the Sikorsky Aircraft Corporation and the Georgia Institute of Technology to develop, improve, and flight test a sensor, guidance, navigation, control, and real-time flight path optimization system to support high performance nap-of-the-Earth helicopter flight. The emphasis here is on optimization for a combination of low height above terrain/obstacles and high speeds. Multiple methods for generating the desired flight path were evaluated, including (1) a simple processing of each laser scan; and (2) a potential field based method. Simulation and flight test results have been obtained utilizing an onboard laser scanner to detect terrain and obstacles while flying at low altitude, and have successfully demonstrated obstacle avoidance in a realistic semi-urban environment at speeds up to 40 ft/s while maintaining a miss distance of 50 ft horizontally and vertically. These results indicate that the technical approach is sound, paving the way for testing of even lower altitudes, higher speeds, and more aggressive maneuvering in future work

StarRunner: A Single-Stage-to-Orbit, Airbreathing, Hypersonic Propulsion System

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference And Exhibit Fort Lauderdale, FL, July 11-14, 2004.In response to the request for proposal (RFP) for the 2003 AIAA Undergraduate Team Engine Design Competition, the FAS Propulsion Design team from the Georgia Institute of Technology presents StarRunner: A Single-Stage-to-Orbit (SSTO), Airbreathing, Hypersonic Propulsion System. Low-cost, highly reliable access to low-Earth orbit (LEO) and the International Space Station (ISS) is an area of continuing research and debate. StarRunner is proposed to supplement a notional Crew Transfer Vehicle through the ability to deliver a 25,000 lb payload to the ISS. The horizontal takeoff/horizontal landing (HTHL) vehicle makes use of a turbine-based combined cycle (TBCC) propulsion system consisting of 14 low-bypass-ratio turbofan engines and a dual-mode ramjet/scramjet propulsion system for high-speed flight. The vehicle also takes advantage of ultra-high-temperature ceramic thermal protection materials and uses hydrogen fuel for regenerative cooling of engine components. StarRunner is compatible with standard runways, with a gross takeoff weight of approximately 1,000,000 lbs, and has a cost per pound to orbit of approximately $825/lb. This advanced, fully reusable space transport vehicle and integrated propulsion system design demonstrates student efforts to understand issues facing the space launch community. Future enabling and enhancing technologies for TBCC SSTO launch vehicles are explored and analyzed. The final StarRunner design addresses and proposes several innovative solutions to traditional problems

Effect of Interface Structure on Mechanical Properties of Advanced Composite Materials

This paper deals with the effect of interface structures on the mechanical properties of fiber reinforced composite materials. First, the background of research, development and applications on hybrid composite materials is introduced. Second, metal/polymer composite bonded structures are discussed. Then, the rationale is given for nanostructuring the interface in composite materials and structures by introducing nanoscale features such as nanopores and nanofibers. The effects of modifying matrices and nano-architecturing interfaces on the mechanical properties of nanocomposite materials are examined. A nonlinear damage model for characterizing the deformation behavior of polymeric nanocomposites is presented and the application of this model to carbon nanotube-reinforced and reactive graphite nanotube-reinforced epoxy composite materials is shown

A systematic scoping review of approaches to teaching and assessing empathy in medicine

10.1186/s12909-021-02697-6BMC Medical Education21129

Microsecond Isomer at the N=20 Island of Shape Inversion Observed at FRIB

Excited-state spectroscopy from the first Facility for Rare Isotope Beams (FRIB) experiment is reported. A 24(2)-$\mu$s isomer was observed with the FRIB Decay Station initiator (FDSi) through a cascade of 224- and 401-keV $\gamma$ rays in coincidence with $^{32}\textrm{Na}$ nuclei. This is the only known microsecond isomer ($1{\text{ }\mu\text{s}}\leq T_{1/2} < 1\text{ ms}$) in the region. This nucleus is at the heart of the $N=20$ island of shape inversion and is at the crossroads of spherical shell-model, deformed shell-model, and ab initio theories. It can be represented as the coupling of a proton hole and neutron particle to $^{32}\textrm{Mg}$, $^{32}\textrm{Mg}+\pi^{-1} + \nu^{+1}$. This odd-odd coupling and isomer formation provides a sensitive measure of the underlying shape degrees of freedom of $^{32}\textrm{Mg}$, where the onset of spherical-to-deformed shape inversion begins with a low-lying deformed $2^+$ state at 885 keV and a low-lying shape-coexisting $0_2^+$ state at 1058 keV. We suggest two possible explanations for the 625-keV isomer in $^{32}$Na: a $6^-$ spherical shape isomer that decays by $E2$ or a $0^+$ deformed spin isomer that decays by $M2$. The present results and calculations are most consistent with the latter, indicating that the low-lying states are dominated by deformation.Comment: 7 pages, 5 figures, accepted by Physical Review Letter

The Importance of Sex Stratification in Autoimmune Disease Biomarker Research: A Systematic Review

The immune system is highly dynamic and regulated by many baseline characteristic factors. As such, significant variability may exist among different patient groups suffering from the same autoimmune disease (AD). However, contemporary research practices tend to take the reductionist aggregate approach: they do not segment AD patients before embarking on biomarker discovery. This approach has been productive: many novel AD biomarkers have recently been discovered. Yet, subsequent validation studies of these biomarkers tend to suffer from a lack of specificity, sensitivity, and reproducibility which hamper their translation for clinical use. To enhance reproducibility in validation studies, an optimal discovery-phase study design is paramount: one which takes into account different parameters affecting the immune system biology. In this systematic review, we highlight need for stratification in one such parameter, i.e., sex stratification. We will first explore sex differences in immune system biology and AD prevalence, followed by reported sex-bias in the clinical phenotypes of two ADs—one which more commonly affects females: systemic lupus erythematosus, and one which more commonly affects males: ankylosing spondylitis. The practice of sex stratification in biomarker research may not only advance the discovery of sex-specific AD biomarkers but more importantly, promote reproducibility in subsequent validation studies, thus easing the translation of these novel biomarkers from bench to bedside to improve AD diagnosis. In addition, such practice will also promote deeper understanding for differential AD pathophysiology in males and females, which will be useful for the development of more effective interventions for each sex type

A marketing plan for Eight O\u27Clock Powdered Juice Drink

The powdered juice industry is not something new to the Philippine market. Eight O Clock is a local product and has been around since the 1980\u27s, initially owned by Sugarland International Products. It is now manufactured and sold by Coca-Cola Bottlers Philippines, Inc. This marketing plan targets socio-economic classes C2 and D, with its primary target market of Filipino mothers, ages 25 to 45 years old. The secondary target market would be children ages 4 to 12. The objectives are (1) to increase top-of-mind awareness to 65%, (2) increase product trial to 90%, and (3) to increase sales by 35%. To be able to achieve these objectives, a re-segmentation of the brand, which will be done through a combination of above-the-line and below-the-line advertising, trade and consumer promotions, and public relations programs, will be implemented to be able to cater to the target market. This one-year marketing plan will require a total of Php64,717,346, which will yield an estimated sales revenue of Php1,093,794,330.50