Investigation of the effects of NaOH dopant level on the physical and mechanical properties of carbon/phenolic composite material

The near-catastrophic erosion of the STS-8A solid rocket booster nozzle was the instigating factor in the recent, and on-going, intensive investigation of carbon/phenolic composite materials. Much of this effort has been focused on the effect of sodium contamination on the carbon fibers. It is known that sodium acts as a catalyst in the oxidation of the fibers at elevated temperatures. A study was undertaken to determine what changes were caused by variation in sodium content. Investigations were conducted in three areas: (1) phenolic resin; (2) carbon/phenolic prepreg; and (3) cured laminates. Due to the exploratory nature of the studies, a variety of tests in addition to those normally run in production facilities were considered. The experimental methodologies and results of these experiments are discussed, and recommendations for improving techniques and extending the research program are presented

NASA Perspective and Initiatives in Additive Manufacturing

No abstract availabl

Overview of NASA Initiatives in 3D Printing and Additive Manufacturing

No abstract availabl

Advanced Sensors for NASA's Exploration Missions

This paper presents a variety of advanced sensors needed for NASA's space exploration. The topics include: 1) The vision of the President of the United States of America for Space Exploration; 2) The report of the President's Commission on Implementation of United States Space Exploration Policy; 3) Exploration Systems Interim Report; 4) Major areas of sensor needs; 5) Classes of material; and 6) Variety of Sensors for Space Exploration

Additive Manufacturing for Human Space Exploration

NASAs In Space Manufacturing Initiative (ISM): The Case for ISM - Why; ISM Path to Exploration; In Space Robotic Manufacturing and Assembly (IRMA). Additive Manufacturing (AM) Development For Liquid Rocket Engine Space Flight Hardware. MSFC (Marshall Space Flight Center) Standard and Specification For Additively Manufactured Space Flight Hardware

Ketamine for Refractory Headache: A Retrospective Analysis.

BACKGROUND AND OBJECTIVES: The burden of chronic headache disorders in the United States is substantial. Some patients are treatment refractory. Ketamine, an N-methyl-D-aspartate antagonist, provides potent analgesia in subanesthetic doses in chronic pain, and limited data suggest it may alleviate headache in some patients. METHODS: We performed a retrospective study of 61 patients admitted over 3 years for 5 days of intravenous therapy that included continuous ketamine to determine responder rate and patient and ketamine infusion characteristics. Pain ratings at 2 follow-up visits were recorded. An immediate responder was a patient with decrease of 2 points or greater in the numerical rating scale (0-10) from start to final pain in the hospital. Sustained response at office visits 1 and 2 was determined based on maintaining the 2-point improvement at those visits. Patients were assessed daily for pain and adverse events (AEs). RESULTS: Forty-eight (77%) of the 61 patients were immediate responders. There were no differences regarding demographics, opioid use, or fibromyalgia between immediate responders and nonresponders. Maximum improvement occurred 4.56 days (mean) into treatment. Sustained response occurred in 40% of patients at visit 1 (mean, 38.1 days) and 39% of patients at visit 2 (mean, 101.3 days). The mean maximum ketamine rate was 65.2 ± 2.8 mg/h (0.76 mg/kg per hour). Ketamine rates did not differ between groups. Adverse events occurred equally in responders and nonresponders and were mild. CONCLUSIONS: Ketamine was associated with short-term analgesia in many refractory headache patients with tolerable adverse events. A prospective study is warranted to confirm this and elucidate responder characteristics

The Impact of Family Rituals and Maternal Depressive Symptoms on Child Externalizing Behaviors: An Urban–Rural Comparison

Background The association between maternal depression and child negative behavior outcomes has been well established in the literature. However, understanding how maternal depression is associated with child behaviors will have important implications for research and intervention strategies. Objective We used samples from two distinct family contexts: urban, middle-class families (N = 454); and rural, low-income families (N = 240), to compare the impact of family rituals and maternal depressive symptoms on child externalizing behaviors. We also examined the impact of maternal depressive symptoms on family rituals. Methods Structural equation modeling and multiple group analyses were conducted. Child age, child gender, mother age, mother education, mother partner status, family income, and family size served as control variables. Indirect effect tests and incremental validity tests were performed. Results Depressive symptoms were linked to externalizing behaviors in both samples. The impacts of family rituals on child externalizing behaviors were more context-specific. For urban, middle-class families, vacations played a particularly helpful intermediate role. Also, in these families, maternal depressive symptoms were associated with less involvement in religious holidays. For rural, low-income families, involvement in annual celebrations was associated with less child externalizing behaviors, although maternal depressive symptoms did not impact involvement in any family rituals. Conclusions Results suggest that family context matters in determining the impacts of maternal depression on the practice of family rituals, as well as the benefits of family rituals for child behaviors, and that certain family rituals can do more than others to reduce child externalizing behaviors (e.g., vacation)

In Space and for Space Additive Manufacturing Initiatives at NASA Marshall Space Flight Center

No abstract availabl