Reusable rocket engine turbopump condition monitoring

Significant improvements in engine readiness with attendant reductions in maintenance costs and turnaround times can be achieved with an engine condition monitoring system (CMS). The CMS provides real time health status of critical engine components, without disassembly, through component monitoring with advanced sensor technologies. Three technologies were selected to monitor the rotor bearings and turbine blades: the isotope wear detector and fiber optic deflectometer (bearings), and the fiber optic pyrometer (blades). Signal processing algorithms were evaluated and ranked for their utility in providing useful component health data to unskilled maintenance personnel. Design modifications to current configuration Space Shuttle Main Engine (SSME) high pressure turbopumps and the MK48-F turbopump were developed to incorporate the sensors

Nonintrusive shaft speed sensor

Reusable rocket engines such as the Space Shuttle Main Engines (SSME), the Orbital Transfer Vehicles (OTV), etc., have throttling capabilities that require real-time, closed-loop control systems of engine propellant flows, combustion temperatures and pressures, and turbopump rotary speeds. In the case of the SSME, there are four turbopumps that require real-time measurement and control of their rotary speeds. Variable-reluctance magnetic speed sensors were designed, fabricated, and tested for all four turbopumps, resulting in the successful implementation and operation of three of these speed sensors during each of the 12 Shuttle flights

OTVE combustor wall condition monitoring

Conventional ultrasonics, eddy current, and electromagnetic acoustic transduction (EMAT) technologies were evaluated to determine their capability of measuring wall thickness/wear of individual cooling channels in test specimens simulating conditions in the throat region of an OTVE combustion chamber liner. Quantitative results are presented for the eddy current technology, which was shown to measure up to the optimum 20-mil wall thickness with near single channel resolution. Additional results demonstrate the capability of the conventional ultrasonics and EMAT technologies to detect a thinning or cracked wall. Recommendations for additional eddy current and EMAT development tests are presented

DNA methylation and gene deletion analysisof brain metastases in melanoma patients identifies mutually exclusive molecular alterations

Background: The brain is a common target of metastases for melanoma patients. Little is known about the genetic and epigenetic alterations in melanoma brain metastases (MBMs). Unraveling these molecular alterations is a key step in understanding their aggressive nature and identifying novel therapeutic targets. Methods: Genome-wide DNA methylation analyses of MBMs (n = 15) and normal brain tissues (n = 91) and simultaneous multigene DNA methylation and gene deletion analyses of metastatic melanoma tissues (99 MBMs and 43 extracranial metastases) were performed. BRAF and NRAS mutations were evaluated in MBMs by targeted sequencing. Results: MBMs showed significant epigenetic heterogeneity. RARB, RASSF1, ESR1, APC, PTEN, and CDH13 genes were frequently hypermethylated. Deletions were frequently detected in the CDKN2A/B locus. Of MBMs, 46.1% and 28.8% had BRAF and NRAS missense mutations, respectively. Compared with lung and liver metastases, MBMs exhibited higher frequency of CDH13 hypermethylation and CDKN2A/B locus deletion. Mutual exclusivity between hypermethylated genes and CDKN2A/B locus deletion identified 2 clinically relevant molecular subtypes of MBMs. CDKN2A/B deletions were associated with multiple MBMs and frequently hypermethylated genes with shorter time to brain metastasis. Conclusions: Melanoma cells that colonize the brain harbor numerous genetically and epigenetically altered genes. This study presents an integrated genomic and epigenomic analysis that reveals MBM-specific molecular alterations and mutually exclusive molecular subtypes.Fil: Marzese, Diego Matías. John Wayne Cancer Institute. Department of Molecular Oncology; Estados UnidosFil: Scolyer, Richard A.. Melanoma Institute Australia; Australia. Royal Prince Alfred Hospital; Australia. University of Sydney; AustraliaFil: Roque Moreno, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Cienicas Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Vargas Roig, Laura Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Huynh, Jamie L.. John Wayne Cancer Institute. Department of Molecular Oncology; Estados UnidosFil: Wilmott, James S.. University of Sydney; Australia. Melanoma Institute Australia; AustraliaFil: Murali, Rajmohan. Memorial Sloan-Kettering Cancer Center; Estados UnidosFil: Buckland, Michael E.. University of Sydney; Australia. Royal Prince Alfred Hospital; AustraliaFil: Barkhoudarian, Garni. Saint John's Health Center; Estados UnidosFil: Thompson, John F.. Royal Prince Alfred Hospital; Australia. University of Sydney; AustraliaFil: Morton, Donald L.. John Wayne Cancer Institute. Department of Molecular Oncology; Estados UnidosFil: Kelly, Daniel F.. Saint John's Health Center; Estados UnidosFil: Hoon, Dave S. B.. John Wayne Cancer Institute. Department of Molecular Oncology; Estados Unido

The Minimal Clinically Important Difference of the Anterior Skull Base Nasal Inventory-12.

BACKGROUND: The minimal clinically important difference (MCID) is defined as the smallest change in health-related quality of life (QOL) that patients consider meaningful. The MCID is essential for determining clinically significant changes, rather than simply statistically significant changes, in QOL scores. The Anterior Skull Base Nasal Inventory-12 (ASK Nasal-12), a site-specific sinonasal QOL instrument, has emerged as a standard instrument for assessing QOL in patients who have undergone endonasal transsphenoidal surgery. OBJECTIVE: To determine the MCID for the ASK Nasal-12. METHODS: Distribution- and anchor-based methods were used to determine the MCID for the ASK Nasal-12 based on raw data from a multicenter prospective QOL study of 218 patients. RESULTS: Two distribution-based statistical methods, the one-half standard deviation method and the effect-size method, both yielded MCIDs of 0.37 (medium effect). The first anchor-based method, using the 2-wk postoperative overall nasal functioning item as the anchor, yielded an MCID of 0.31. The second anchor-based method, using the 2-wk postoperative Short Form Health Survey 8 bodily pain item as the anchor, yielded an MCID of 0.29. CONCLUSION: The largest MCID obtained for the ASK Nasal-12 using 4 statistical methods 2 wk postoperatively was 0.37. This information provides clinicians with an essential context for determining the clinical significance of changes in QOL scores after interventions. Our results will help clinicians better interpret QOL scores and design future studies that are powered to detect meaningful QOL changes