506 research outputs found
A Scale Model Investigation of Rocket Exhaust Effects on an Improved Saturn V Booster Utilizing Solid Propellant Strap-Ons
Missions currently being considered by NASA beyond the Apollo manned lunar landing will require a larger payload capability than is available with the current generation of Saturn boosters. An attractive method of achieving the desired payload increase consists of adding large solid propellant rocket motors (strap-ons) to existing boosters to augment the thrust from the basic booster liquidpropellant engines. The soundness of this approach has already been demonstrated by such vehicles as the Titan III-C and Thrust Augmented Thor/Delta, where significant performance increases have been obtained within current state of the art and at minimum cost, while simultaneously retaining the proven reliability characteristics of the previously developed basic booster.
The possibility of increasing the performance of the Saturn V booster through the addition of previously developed 120-inch solid-propellant rochet motor strap-ons to the S-IC first stage is currently being evaluated by the Marshall Space Flight Center of NASA. One of the items of concern with such a configuration is the possibility of a detrimental alteration in the base environment of the S-IC from that which will exist with only the basic complement of five F-l liquid propellant rockets. For example, interactions between the liquid propellant and/or solid propellant rocket exhaust plumes (a total of nine rocket exhausts are involved) may result in increased flow recirculation and attendant increases in base pressure and convective heating. Further, radiant heating to the base may also be significantly greater because of the presence of the aluminized solid propellant exhaust plumes.
In addition to these potential flight problems, consideration must also be directed toward the launch stand environment. Rocket exhaust recirculation from the flame deflector can produce a severe thermal environment in the booster base region during the ignition and lift-off sequence, Launch stand components must also be suitably protected to withstand the 5000 °F exhaust gas impingement as the booster lifts off
Better international relationships through the teaching of geography
This item was digitized by the Internet Archive. Thesis (Ed.M.)--Boston Universityhttps://archive.org/details/betterinternatio00hen
The ICIDH-2: Developments for a new era of outcomes research
ABSTRACT. Gray DB, Hendershot GE. The ICIDH-2: developments for a new era of outcomes research. Arch Phys Med Rehabil 2000;81 Suppl 2:S10-S14. This article reviews the important concepts that led to the development of the International Classification of Impairments, Disabilities, and Handicaps (ICIDH), explicates the International Classification of Functioning and Disability (ICIDH-2), and discusses implications of the ICIDH-2 as a conceptual framework for outcome measures. The original ICIDH opened the door to include factors outside the traditional classification boundaries of disease, illness, and functional limitations that have framed the concept of disability. The new factors in the ICIDH-2 include a dimension for participation in social activities and a listing of environmental factors that are important for understanding the complexity of disability. The ICIDH-2 offers an opportunity for building a consensus on the terms used to describe disability and on the scope of factors to include in studying disability
Targeted deletion of Hand2 in cardiac neural crest-derived cells influences cardiac gene expression and outflow tract development
AbstractThe basic helix–loop–helix DNA binding protein Hand2 has critical functions in cardiac development both in neural crest-derived and mesoderm-derived structures. Targeted deletion of Hand2 in the neural crest has allowed us to genetically dissect Hand2-dependent defects specifically in outflow tract and cardiac cushion independent of Hand2 functions in mesoderm-derived structures. Targeted deletion of Hand2 in the neural crest results in misalignment of the aortic arch arteries and outflow tract, contributing to development of double outlet right ventricle (DORV) and ventricular septal defects (VSD). These neural crest-derived developmental anomalies are associated with altered expression of Hand2-target genes we have identified by gene profiling. A number of Hand2 direct target genes have been identified using ChIP and ChIP-on-chip analyses. We have identified and validated a number of genes related to cell migration, proliferation/cell cycle and intracellular signaling whose expression is affected by Hand2 deletion in the neural crest and which are associated with development of VSD and DORV. Our data suggest that Hand2 is a multifunctional DNA binding protein affecting expression of target genes associated with a number of functional interactions in neural crest-derived cells required for proper patterning of the outflow tract, generation of the appropriate number of neural crest-derived cells for elongation of the conotruncus and cardiac cushion organization. Our genetic model has made it possible to investigate the molecular genetics of neural crest contributions to outflow tract morphogenesis and cell differentiation
Forages for Horses Revamped
The Forages for Horses program began in Ohio in1998 as a collaboration between the Ohio Forages & Grasslands Council and Ohio State University Extension. Over time, additional collaborations with the Natural Resources Conservation Service, Ohio Department of Agriculture and local Soil and Water Conservation Districts expanded the program. At its inception, one to three educators would partner to provide eight hours of in-person lectures followed by a pasture walk to better the management practices of equine enthusiasts. From 2021 through 2022, the curriculum was adapted for a hybrid classroom and included three 90-minute live webinars featuring nine different presentations followed by online social events. The modifications to the curriculum were made to improve access to equine resources and grazing education across Ohio. The Forages for Horses resources were also updated as part of the process. Learning modules posted in Canvas (an online learning management system) provided additional information that expanded upon the original curriculum. In 2022, 41 students from Ohio and surrounding states registered for the online course and webinars. Participants were able to hear directly from educators - more than in past iterations of the program– to expand their depth of knowledge and increase opportunities for participation without the location of the class posing a barrier for attendance. This program will continue to be revised over the coming years to remain relevant and accessible to Ohioans
Biomarker Testing to Estimate Under-Reported Heavy Alcohol Consumption by Persons with HIV Initiating ART in Uganda
Alcohol affects the transmission and treatment of HIV, yet may be under-reported in resource-limited settings. We compared self-reported alcohol consumption with levels of plasma carbohydrate-deficient transferrin (%CDT), a biomarker of heavy alcohol consumption, in persons initiating antiretroviral therapy in Uganda. Almost seven percent (6.7%) of persons reporting abstaining and 10% reporting consuming 1–40 drinks in the prior month tested positive for %CDT, and actual under-report may be higher due to low sensitivity of %CDT. These results suggest likely under-report in those reporting abstaining and current drinking. Improved identification of heavy alcohol consumption is needed for research and clinical purposes
Ohio Pastures for Profit Online
The Pastures for Profit program is an established course created through a collaboration between Ohio State University Extension, Central State University, USDA-Natural Resources Conservation Service, Ohio Federation of Soil and Water Conservation Districts, Ohio Department of Agriculture, and the Ohio Forage and Grasslands Council. In 2021, due to COVID-19, the Pastures for Profit curriculum was adapted to a virtual classroom setting and was offered again in 2022. The virtual experience consisted of three live webinars pairing with corresponding modules in Scarlet Canvas. Enrolled students were also mailed traditional course materials for personal use. Module content was newly developed and compiled to compliment the traditional materials and included videos, quizzes, additional presentations, and technical resources. The course materials were organized and taught by a team of over 50 collaborators. During the three live webinars, nearly 20 speakers presented on topics including the basics of grazing, plant and animal science, and grazing plans. A total of 168 people enrolled in Scarlet Canvas in the two-year time frame from over 15 states and included producers, educators, technical service providers, and government agency staff. Each live session was recorded and made available to the class for access at their convenience. Those who completed the course obtained a signed certificate of completion. This platform allowed for an expanded audience reach than in the past
Aortic Complications Associated With Pregnancy in Marfan Syndrome: The NHLBI National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC)
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139073/1/jah31693.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139073/2/jah31693_am.pd
GenTAC registry report: Gender differences among individuals with genetically triggered thoracic aortic aneurysm and dissection
Previous data suggest women are at increased risk of death from aortic dissection. Therefore, we analyzed data from the GenTAC registry, the NIH‐sponsored program that collects information about individuals with genetically triggered thoracic aortic aneurysms and cardiovascular conditions. We performed cross‐sectional analyses in adults with Marfan syndrome (MFS), familial thoracic aortic aneurysm or dissection (FTAAD), bicuspid aortic valve (BAV) with thoracic aortic aneurysm or dissection, and subjects under 50 years of age with thoracic aortic aneurysm or dissection (TAAD <50 years). Women comprised 32% of 1,449 subjects and were 21% of subjects with BAV, 34% with FTAAD, 22% with TAAD <50 years, and 47% with MFS. Thoracic aortic dissections occurred with equal gender frequency yet women with BAV had more extensive dissections. Aortic size was smaller in women but was similar after controlling for BSA. Age at operation for aortic valve dysfunction, aneurysm or dissection did not differ by gender. Multivariate analysis (adjusting for age, BSA, hypertension, study site, diabetes, and subgroup diagnoses) showed that women had fewer total aortic surgeries (OR = 0.65, P < 0.01) and were less likely to receive angiotensin converting enzyme inhibitors (ACEi; OR = 0.68, P < 0.05). As in BAV, other genetically triggered aortic diseases such as FTAAD and TAAD <50 are more common in males. In women, decreased prevalence of aortic operations and less treatment with ACEi may be due to their smaller absolute aortic diameters. Longitudinal studies are needed to determine if women are at higher risk for adverse events. © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97193/1/35836_ftp.pd
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