Milliwatt Generator Project

NASA Astrophysics Data System (ADS)

Latimer, T. W.; Rinehart, G. H.

1992-05-01

This report covers progress on the Milliwatt Generator Project from April 1986 through March 1988. Activities included fuel processing and characterization, production of heat sources, fabrication of pressure-burst test units, compatibility studies, impact testing, and examination of surveillance units. The major task of the Los Alamos Milliwatt Generator Project is to fabricate MC2893A heat sources (4.0 W) for MC2730A radioisotope thermoelectric generators (RTG's) and MC3599 heat sources (4.5 W) for MC3500 RTG's. The MWG Project interfaces with the following contractors: Sandia National Laboratories, Albuquerque (designer); E.I. du Pont de Nemours and Co. (Inc.), Savannah River Plant (fuel); Monsanto Research Corporation, Mound Facility (metal hardware); and General Electric Company, Neutron Devices Department (RTG's). In addition to MWG fabrication activities, Los Alamos is involved in (1) fabrication of pressure-burst test units, (2) compatibility testing and evaluation, (3) examination of surveillance units, and (4) impact testing and subsequent examination of compatibility and surveillance units.

Detection of fibrin generation alterations in dogs with haemangiosarcoma using resonance thrombography.

PubMed

Mischke, R; Wohlsein, P; Schoon, H-A

2005-01-01

The objective of the study was to examine the alterations of fibrin generation in dogs with haemangiosarcoma using resonance thrombography. The second objective was to evaluate the sensitivity of this method for the detection of hypofibrinogenaemia and/or increased fibrin(ogen) degradation product (FDP) concentration. Resonance thrombogram (RTG) measurements with two different instruments were performed in 30 unselected dogs with haemangiosarcoma, 14 of which had decreased fibrinogen and 28 of which had an increased FDP concentration (p<0.0001). The RTG-reaction time was less sensitive than the fibrin formation time (RTG-f) and fibrin amplitude (RTG-F). The RTG-f and RTG-F indicated reliably a decrease in fibrinogen concentration (sensitivity: 0.93). The sensitivity of detection of increased FDP levels was considerably higher than that of thrombin time. However, false-negative results were found even at FDP concentrations > or =120 mg/l, especially in cases with high fibrinogen level. Both machines showed similar sensitivity. The results of this study indicate that canine haemangiosarcoma is frequently associated with severe alterations of fibrin generation due to low fibrinogen and high FDP levels leading to distinct RTG abnormalities. The global test RTG reacts sensitively to a decreased fibrinogen level whereas its accuracy to detect FDP concentrations occurring under pathophysiological conditions is limited. A significant alteration of fibrin generation induced by FDPs may not occur until the serum FDP concentration exceeds 60 mg/l.

Visual imaging control systems of the Mariner to Jupiter and Saturn spacecraft

NASA Technical Reports Server (NTRS)

Larks, L.

1979-01-01

Design and fabrication of optical systems for the Mariner Jupiter Saturn (Voyager) mission is described. Because of the long distances of these planets from the sun, the spacecraft was designed without solar panels with the electricity generated on-board by radio-isotope thermal generators (RTG). The presence of RTG's and Jupiter radiation environment required that the optical systems be fabricated out of radiation stabilized materials. A narrow angle and a wide angle camera are located on the spacecraft scan platform, with the narrow angle lens a modification of the Mariner 10 lens. The optical system is described, noting that the lens was modified by moving the aperture correctors forward and placing a spider mounted secondary mirror in the original back surface of the second aperture corrector. The wide angle lens was made out of cerium doped, radiation stabilized optical glass with greatest blue transmittance, which would be resistant to RTG and Jupiter radiation.

Lack of effect of ezogabine/retigabine on the pharmacokinetics of digoxin in healthy individuals: results from a drug–drug interaction study

PubMed Central

Tompson, Debra J; Crean, Christopher S; Buraglio, Mauro; Arumugham, Thangam

2014-01-01

Introduction The potential for ezogabine/retigabine (EZG/RTG) and its N-acetyl metabolite (NAMR) to inhibit the transporter protein P-glycoprotein-(P-gp)-mediated digoxin transport was tested in vitro. EZG/RTG did not inhibit P-gp. However, NAMR inhibited P-gp in a concentration-dependent manner. Based on these in vitro results, NAMR had the potential to inhibit P-gp at therapeutic doses of EZG/RTG (600–1,200 mg/day). As digoxin has a narrow therapeutic index, inhibition of digoxin clearance may have an impact on its safety. Methods An open-label, single-center, two session, fixed-sequence study was conducted to assess the effect of co-administration of therapeutic doses of EZG/RTG on digoxin pharmacokinetics in healthy adults. In session 1, subjects received a single dose of digoxin 0.25 mg. In session 2, EZG/RTG was up-titrated over 6 weeks. Digoxin 0.25 mg was co-administered at EZG/RTG steady-state doses of 600, 900, and, based on tolerability, 1,050/1,200 mg/day. Blood samples were collected over 144 hours for determination of digoxin, EZG/RTG, and NAMR concentrations. Urine samples were collected over 48 hours for determination of digoxin concentrations. Results Of 30 subjects enrolled, 29 were included in the pharmacokinetic analysis. Compared with digoxin alone, co-administration with EZG/RTG led to small increases in the digoxin plasma area under the concentration–time curve (AUC)0–120 at doses of 600, 900, and 1,050/1,200 mg (geometric mean ratio 1.08, 90% confidence interval [CI] 1.01–1.15; 1.18, 90% CI 1.10–1.27; 1.13, 90% CI 1.05–1.21, respectively). Safety was consistent with previous repeat-dose studies of EZG/RTG in healthy subjects. Conclusion Co-administration of EZG/RTG across the therapeutic range resulted in small, non-dose-dependent and non-clinically relevant increases in digoxin systemic exposure, suggesting that digoxin dose adjustment is not necessary. PMID:25342921

Characteristics and Impact Factors of Renal Threshold for Glucose Excretion in Patients with Type 2 Diabetes Mellitus.

PubMed

Yue, Xiao Dan; Wang, Jing Yu; Zhang, Xin Rong; Yang, Ju Hong; Shan, Chun Yan; Zheng, Miao Yan; Ren, Hui Zhu; Zhang, Yi; Yang, Shao Hua; Guo, Zhen Hong; Chang, Bai; Chang, Bao Cheng

2017-04-01

Sodium glucose co-transporter 2 (SGLT-2) inhibitors are newly developed but promising medicine for type 2 diabetes. However, patients with a different renal threshold for glucose excretion (RT(G)) may have a different reaction to this medicine. Therefore, the objective of this study was to investigate the characteristics of RT(G) and its impact factors in patients with type 2 diabetes mellitus (T2DM). The clinical and laboratory data of 36 healthy individuals and 168 in-hospital patients with T2DM were collected and analyzed, RT(G) was calculated using blood glucose (BG) measured by dynamic BG monitoring, urinary glucose excretion (UGE) and estimated glomerular filtration rate (eGFR). The characteristics of RT(G) were investigated. The risk factors for high RT(G) were analyzed using non-conditional logistic regression analysis. Our results found that RT(G) of the T2DM group was higher than that of the healthy individuals (P < 0.05); and 22.22% from the healthy individuals group but 58.33% from the T2DM group had high RT(G). Age, duration of diabetes, body mass index (BMI), and homeostasis model assessment insulin resistance index (HOMA-IR) were independently associated with high RT(G) (P < 0.05). Further stratified analysis revealed that RT(G) in T2DM patients increased with age, duration of diabetes, and BMI. In conclusion, RT(G) is increased in patients with T2DM, especially in those with longer diabetic duration, higher BMI, and those who are older. Therefore, these patients may be more sensitive to SGLT-2 inhibitors. © 2017 The Korean Academy of Medical Sciences.

Anti-melanogenic effects of resveratryl triglycolate, a novel hybrid compound derived by esterification of resveratrol with glycolic acid.

PubMed

Park, Soojin; Seok, Jin Kyung; Kwak, Jun Yup; Choi, Yun-Hyeok; Hong, Seong Su; Suh, Hwa-Jin; Park, Woncheol; Boo, Yong Chool

2016-07-01

Resveratrol is known to inhibit cellular melanin synthesis by multiple mechanisms. Glycolic acid (GA) is used in skin care products for its excellent skin penetration. The purpose of this study was to examine the anti-melanogenic effects of resveratryl triglycolate (RTG), a novel hybrid compound of resveratrol and GA, in comparison with resveratrol, GA, resveratryl triacetate (RTA) and arbutin. Resveratrol, RTG, and RTA inhibited the catalytic activity human tyrosinase (TYR) more potently than arbutin or GA did. Their cytotoxic and anti-melanogenic effects were examined using murine melanoma B16/F10 cells and human epidermal melanocytes (HEMs). The cytotoxicity of RTG was similar to that of resveratrol and RTA. RTG at 3-10 μM decreased melanin levels and cellular TYR activities in α-melanocyte-stimulating hormone-stimulated B16/F10 cells, and L-tyrosine-stimulated HEMs. RTG also suppressed mRNA and protein expression of TYR, tyrosinase-related protein 1, L-3,4-dihydroxyphenylalanine chrome tautomerase, and microphthalmia-associated transcription factor (MITF) in HEMs stimulated with L-tyrosine. This study suggests that, like resveratrol and RTA, RTG can attenuate cellular melanin synthesis effectively through the suppression of MITF-dependent expression of melanogenic enzymes and the inhibition of catalytic activity of TYR enzyme. RTG therefore has potential for use as a cosmeceutical ingredient for skin whitening.

Developing the next Generation of Education Researchers: UCLA's Experience with the Spencer Foundation Research Training Grant

ERIC Educational Resources Information Center

Dorr, Aimee; Arms, Emily; Hall, Valerie

2008-01-01

Background/Context: In the early 1990s, the Spencer Foundation instituted an Institutional Research Training Grant (RTG) program to improve the preparation of the next generation of education researchers. UCLA received an RTG in the first round of competition. Purpose/Objective/Research Question/Focus of Study: UCLA's Spencer RTG program sought to…

Cost Comparison in 2015 Dollars for Radioisotope Power Systems -- Cassini and Mars Science Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Werner, James Elmer; Johnson, Stephen Guy; Dwight, Carla Chelan

Radioisotope power systems (RPSs) have enabled missions requiring reliable, long-lasting power in remote, harsh environments such as space since the early 1960s. Costs for RPSs are high, but are often misrepresented due to the complexity of space missions and inconsistent charging practices among the many and changing participant organizations over the years. This paper examines historical documentation associated with two past successful flight missions, each with a different RPS design, to provide a realistic cost basis for RPS production and deployment. The missions and their respective RPSs are Cassini, launched in 1997, that uses the general purpose heat source (GPHS)more » radioisotope thermoelectric generator (RTG), and Mars Science Laboratory (MSL), launched in 2011, that uses the multi-mission RTG (MMRTG). Actual costs in their respective years are discussed for each of the two RTG designs and the missions they enabled, and then present day values to 2015 are computed to compare the costs. Costs for this analysis were categorized into two areas: development of the specific RTG technology, and production and deployment of an RTG. This latter category includes material costs for the flight components (including Pu-238 and fine weave pierced fabric (FWPF)); manufacturing of flight components; assembly, testing, and transport of the flight RTG(s); ground operations involving the RTG(s) through launch; nuclear safety analyses for the launch and for the facilities housing the RTG(s) during all phases of ground operations; DOE’s support for NEPA analyses; and radiological contingency planning. This analysis results in a fairly similar 2015 normalized cost for the production and deployment of an RTG—approximately $118M for the GPHS-RTG and $109M for the MMRTG. In addition to these two successful flight missions, the costs for development of the MMRTG are included to serve as a future reference. Note that development costs included herein for the MMRTG do not include costs from NASA staff or facilities for their development efforts—they only include the amounts costed by DOE and DOE contractors. The 2015 value for MMRTG development is $83M. Both of the RPS types analyzed herein use the general purpose heat source (GPHS) module as the “heart of the RPS.” The estimates presented herein do not include development costs for the GPHS. These estimates also do not include the RPS infrastructure cost to maintain the facilities, equipment, and personnel necessary to enable the production of RPSs, except to the extent that the infrastructure is utilized during the production campaigns to provide RPSs for missions. It was not until after the Cassini mission that an RPS infrastructure funding structure was defined and funded separately from mission-specific elements. The information presented herein could allow for more accurate budget planning estimates for space missions being considered over the next decade and beyond.« less

Simulating the Gradually Deteriorating Performance of an RTG

NASA Technical Reports Server (NTRS)

Wood, Eric G.; Ewell, Richard C.; Patel, Jagdish; Hanks, David R.; Lozano, Juan A.; Snyder, G. Jeffrey; Noon, Larry

2008-01-01

Degra (now in version 3) is a computer program that simulates the performance of a radioisotope thermoelectric generator (RTG) over its lifetime. Degra is provided with a graphical user interface that is used to edit input parameters that describe the initial state of the RTG and the time-varying loads and environment to which it will be exposed. Performance is computed by modeling the flows of heat from the radioactive source and through the thermocouples, also allowing for losses, to determine the temperature drop across the thermocouples. This temperature drop is used to determine the open-circuit voltage, electrical resistance, and thermal conductance of the thermocouples. Output power can then be computed by relating the open-circuit voltage and the electrical resistance of the thermocouples to a specified time-varying load voltage. Degra accounts for the gradual deterioration of performance attributable primarily to decay of the radioactive source and secondarily to gradual deterioration of the thermoelectric material. To provide guidance to an RTG designer, given a minimum of input, Degra computes the dimensions, masses, and thermal conductances of important internal structures as well as the overall external dimensions and total mass.

Comparison of In Vivo and Ex Vivo MRI for the Detection of Structural Abnormalities in a Mouse Model of Tauopathy

PubMed Central

Holmes, Holly E.; Powell, Nick M.; Ma, Da; Ismail, Ozama; Harrison, Ian F.; Wells, Jack A.; Colgan, Niall; O'Callaghan, James M.; Johnson, Ross A.; Murray, Tracey K.; Ahmed, Zeshan; Heggenes, Morten; Fisher, Alice; Cardoso, M. Jorge; Modat, Marc; O'Neill, Michael J.; Collins, Emily C.; Fisher, Elizabeth M. C.; Ourselin, Sébastien; Lythgoe, Mark F.

2017-01-01

With increasingly large numbers of mouse models of human disease dedicated to MRI studies, compromises between in vivo and ex vivo MRI must be fully understood in order to inform the choice of imaging methodology. We investigate the application of high resolution in vivo and ex vivo MRI, in combination with tensor-based morphometry (TBM), to uncover morphological differences in the rTg4510 mouse model of tauopathy. The rTg4510 mouse also offers a novel paradigm by which the overexpression of mutant tau can be regulated by the administration of doxycycline, providing us with a platform on which to investigate more subtle alterations in morphology with morphometry. Both in vivo and ex vivo MRI allowed the detection of widespread bilateral patterns of atrophy in the rTg4510 mouse brain relative to wild-type controls. Regions of volume loss aligned with neuronal loss and pathological tau accumulation demonstrated by immunohistochemistry. When we sought to investigate more subtle structural alterations in the rTg4510 mice relative to a subset of doxycycline-treated rTg4510 mice, ex vivo imaging enabled the detection of more regions of morphological brain changes. The disadvantages of ex vivo MRI may however mitigate this increase in sensitivity: we observed a 10% global shrinkage in brain volume of the post-mortem tissues due to formalin fixation, which was most notable in the cerebellum and olfactory bulbs. However, many central brain regions were not adversely affected by the fixation protocol, perhaps due to our “in-skull” preparation. The disparity between our TBM findings from in vivo and ex vivo MRI underlines the importance of appropriate study design, given the trade-off between these two imaging approaches. We support the utility of in vivo MRI for morphological phenotyping of mouse models of disease; however, for subtler phenotypes, ex vivo offers enhanced sensitivity to discrete morphological changes. PMID:28408879

Comparison of In Vivo and Ex Vivo MRI for the Detection of Structural Abnormalities in a Mouse Model of Tauopathy.

PubMed

Holmes, Holly E; Powell, Nick M; Ma, Da; Ismail, Ozama; Harrison, Ian F; Wells, Jack A; Colgan, Niall; O'Callaghan, James M; Johnson, Ross A; Murray, Tracey K; Ahmed, Zeshan; Heggenes, Morten; Fisher, Alice; Cardoso, M Jorge; Modat, Marc; O'Neill, Michael J; Collins, Emily C; Fisher, Elizabeth M C; Ourselin, Sébastien; Lythgoe, Mark F

2017-01-01

With increasingly large numbers of mouse models of human disease dedicated to MRI studies, compromises between in vivo and ex vivo MRI must be fully understood in order to inform the choice of imaging methodology. We investigate the application of high resolution in vivo and ex vivo MRI, in combination with tensor-based morphometry (TBM), to uncover morphological differences in the rTg4510 mouse model of tauopathy. The rTg4510 mouse also offers a novel paradigm by which the overexpression of mutant tau can be regulated by the administration of doxycycline, providing us with a platform on which to investigate more subtle alterations in morphology with morphometry. Both in vivo and ex vivo MRI allowed the detection of widespread bilateral patterns of atrophy in the rTg4510 mouse brain relative to wild-type controls. Regions of volume loss aligned with neuronal loss and pathological tau accumulation demonstrated by immunohistochemistry. When we sought to investigate more subtle structural alterations in the rTg4510 mice relative to a subset of doxycycline-treated rTg4510 mice, ex vivo imaging enabled the detection of more regions of morphological brain changes. The disadvantages of ex vivo MRI may however mitigate this increase in sensitivity: we observed a 10% global shrinkage in brain volume of the post-mortem tissues due to formalin fixation, which was most notable in the cerebellum and olfactory bulbs. However, many central brain regions were not adversely affected by the fixation protocol, perhaps due to our "in-skull" preparation. The disparity between our TBM findings from in vivo and ex vivo MRI underlines the importance of appropriate study design, given the trade-off between these two imaging approaches. We support the utility of in vivo MRI for morphological phenotyping of mouse models of disease; however, for subtler phenotypes, ex vivo offers enhanced sensitivity to discrete morphological changes.

RTG Safety Tests

NASA Technical Reports Server (NTRS)

1989-01-01

The primary objective of STS-34 was to launch Galileo on its trip to Jupiter. The Galileo spacecraft contains two Radioisotope Thermoelectric Generators (RTG), which contains plutonium. This videotape shows and the accompanying material explains the tests that the RTG containment vessel has been subjected to, and the results of the tests. The videotape shows the trajectory of the Galileo spacecraft, a cutaway view of an RTG, the Plutonium-238 fuel capsule, and seven of the tests on the RTG.

Induction of antiviral genes, Mx and vig-1, by dsRNA and Chum salmon reovirus in rainbow trout monocyte/macrophage and fibroblast cell lines.

PubMed

DeWitte-Orr, Stephanie J; Leong, Jo-Ann C; Bols, Niels C

2007-09-01

The expression of potential antiviral genes, Mx1, Mx2, Mx3 and vig-1, was studied in two rainbow trout cell lines: monocyte/macrophage RTS11 and fibroblast-like RTG-2. Transcripts were monitored by RT-PCR; Mx protein by Western blotting. In unstimulated cultures Mx1 and vig-1 transcripts were seen occasionally in RTS11 but rarely in RTG-2. A low level of Mx protein was seen in unstimulated RTS11 but not in RTG-2. In both cell lines, Mx and vig-1 transcripts were induced by a dsRNA, poly inosinic: poly cytidylic acid (poly IC), and by Chum salmon reovirus (CSV). Medium conditioned by cells previously exposed to poly IC or CSV and assumed to contain interferon (IFN) induced the antiviral genes in RTS11. However, RTG-2 responded only to medium conditioned by RTG-2 exposed previously to CSV. In both cell lines, poly IC and CSV induced Mx transcripts in the presence of cycloheximide, suggesting a direct induction mechanism, independent of IFN, was also possible. For CSV, ribavirin blocked induction in RTS11 but not in RTG-2, suggesting viral RNA synthesis was required for induction only in RTS11. In both RTS11 and RTG-2 cultures, Mx protein showed enhanced accumulation by 24h after exposure to poly IC and CSV, but subsequently Mx protein levels declined back to control levels in RTS11 but not in RTG-2. These results suggest that Mx can be regulated differently in macrophages and fibroblasts.

Muscarinic Receptor-Dependent Long Term Depression in the Perirhinal Cortex and Recognition Memory are Impaired in the rTg4510 Mouse Model of Tauopathy.

PubMed

Scullion, Sarah E; Barker, Gareth R I; Warburton, E Clea; Randall, Andrew D; Brown, Jonathan T

2018-02-26

Neurodegenerative diseases affecting cognitive dysfunction, such as Alzheimer's disease and fronto-temporal dementia, are often associated impairments in the visual recognition memory system. Recent evidence suggests that synaptic plasticity, in particular long term depression (LTD), in the perirhinal cortex (PRh) is a critical cellular mechanism underlying recognition memory. In this study, we have examined novel object recognition and PRh LTD in rTg4510 mice, which transgenically overexpress tau P301L . We found that 8-9 month old rTg4510 mice had significant deficits in long- but not short-term novel object recognition memory. Furthermore, we also established that PRh slices prepared from rTg4510 mice, unlike those prepared from wildtype littermates, could not support a muscarinic acetylcholine receptor-dependent form of LTD, induced by a 5 Hz stimulation protocol. In contrast, bath application of the muscarinic agonist carbachol induced a form of chemical LTD in both WT and rTg4510 slices. Finally, when rTg4510 slices were preincubated with the acetylcholinesterase inhibitor donepezil, the 5 Hz stimulation protocol was capable of inducing significant levels of LTD. These data suggest that dysfunctional cholinergic innervation of the PRh of rTg4510 mice, results in deficits in synaptic LTD which may contribute to aberrant recognition memory in this rodent model of tauopathy.

Feasibility investigation of the Accelerated Skill Acquisition Program (ASAP): insights into reach-to-grasp coordination of individuals with postacute stroke.

PubMed

Tretriluxana, Jarugool; Runnarong, Nuttakarn; Tretriluxana, Suradej; Prayoonwiwat, Naraporn; Vachalathiti, Roongtiwa; Winstein, Carolee

2013-01-01

Skill acquisition, capacity building, and motivational enhancements are the basis of the Accelerated Skill Acquisition Program (ASAP) and form the foundation for effective incorporation of the paretic upper extremity into life activities. This is the first phase I trial to deliver ASAP during the postacute interval in mildly to moderately impaired stroke survivors and to include an assessment of paretic reach-to-grasp (RTG) coordination using RTG task and cross-correlation analyses. Two baseline and posttreatment evaluations consisted of RTG actions, the Wolf Motor Function Test (WMFT), and the Stroke Impact Scale (SIS). An individualized arm therapy program using ASAP principles was administered for a total of 30 hours, 2 hours per day, for 2 to 4 days per week over 5 weeks. Dependent measures were kinematics of RTG actions, RTG coordination, total time score of WMFT, and stroke recovery score of SIS. All participants tolerated ASAP well, and none reported any adverse effects during or after the protocol. When the 2 baseline evaluations were compared, there were no changes in any RTG kinematics or RTG coordination. In contrast, after 30 hours of ASAP, total movement time and deceleration time of RTG actions markedly decreased, maximum reach (transport) velocity strikingly increased, and time of maximum aperture was accomplished later. Additionally, the maximal RTG correlation coefficient increased with a shorter associated time lag. A similar pattern was observed for the clinical outcome measures of WMFT and SIS. The findings demonstrate the feasibility of using an ASAP protocol for patients 1 to 3 months post stroke. Under ASAP, WMFT tasks and RTG actions were performed faster with higher peak transport velocity and a more coordinated RTG pattern. The next step is to determine whether the immediate gains in the skilled RTG actions persist 6 months alter.

Divergent branches of mitochondrial signaling regulate specific genes and the viability of specialized cell types of differentiated yeast colonies.

PubMed

Podholová, Kristýna; Plocek, Vítězslav; Rešetárová, Stanislava; Kučerová, Helena; Hlaváček, Otakar; Váchová, Libuše; Palková, Zdena

2016-03-29

Mitochondrial retrograde signaling mediates communication from altered mitochondria to the nucleus and is involved in many normal and pathophysiological changes, including cell metabolic reprogramming linked to cancer development and progression in mammals. The major mitochondrial retrograde pathway described in yeast includes three activators, Rtg1p, Rtg2p and Rtg3p, and repressors, Mks1p and Bmh1p/Bmh2p. Using differentiated yeast colonies, we show that Mks1p-Rtg pathway regulation is complex and includes three branches that divergently regulate the properties and fate of three specifically localized cell subpopulations via signals from differently altered mitochondria. The newly identified RTG pathway-regulated genes ATO1/ATO2 are expressed in colonial upper (U) cells, the cells with active TORC1 that metabolically resemble tumor cells, while CIT2 is a typical target induced in one subpopulation of starving lower (L) cells. The viability of the second L cell subpopulation is strictly dependent on RTG signaling. Additional co-activators of Rtg1p-Rtg3p specific to particular gene targets of each branch are required to regulate cell differentiation.

Age-related decline in white matter integrity in a mouse model of tauopathy: an in vivo diffusion tensor magnetic resonance imaging study

PubMed Central

Sahara, Naruhiko; Perez, Pablo D.; Lin, Wen-Lang; Dickson, Dennis W.; Ren, Yan; Zeng, Huadong; Lewis, Jada; Febo, Marcelo

2016-01-01

Elevated expression of human hyperphosphorylated tau is associated with neuronal loss and white matter (WM) pathology in Alzheimer’s disease (AD) and related neurodegenerative disorders. Using in vivo diffusion tensor magnetic resonance imaging (DT-MRI) at 11.1 Tesla we measured age-related alterations in WM diffusion anisotropy indices in a mouse model of human tauopathy (rTg4510) and nontransgenic (nonTg) control mice at the age of 2.5, 4.5, and 8 months. Similar to previous DT-MRI studies in AD subjects, 8-month-old rTg4510 mice showed lower fractional anisotropy (FA) values in WM structures than nonTg. The low WM FA in rTg4510 mice was observed in the genu and splenium of the corpus callosum, anterior commissure, fimbria, and internal capsule and was associated with a higher radial diffusivity than nonTg. Interestingly, rTg4510 mice showed lower estimates for the mode of anisotropy than controls at 2.5 months suggesting that changes in this diffusivity metric are detectable at an early stage preceding severe tauopathy. Immunogold electron microscopy partly supports our diffusion tensor imaging findings. At the age of 4 months, rTg4510 mice show axonal tau inclusions and unmyelinated processes. At later ages (12 months and 14 months) we observed inclusions in myelin sheath, axons, and unmyelinated processes, and a “disorganized” pattern of myelinated fiber arrangement with enlarged inter-axonal spaces in rTg4510 but not in nonTg mice. Our data support a role for the progression of tau pathology in reduced WM integrity measured by DT-MRI. Further in vivo DT-MRI studies in the rTg4510 mouse should help better discern the detailed mechanisms of reduced FA and anisotropy mode, and the specific role of tau during neurodegeneration. PMID:24411290

Impact of High Resolution SST Data on Regional Weather Forecasts

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; Case, Jonathon; LaFontaine, Frank; Vazquez, Jorge; Mattocks, Craig

2010-01-01

Past studies have shown that the use of coarse resolution SST products such as from the real-time global (RTG) SST analysis[1] or other coarse resolution once-a-day products do not properly portray the diurnal variability of fluxes of heat and moisture from the ocean that drive the formation of low level clouds and precipitation over the ocean. For example, the use of high resolution MODIS SST composite [2] to initialize the Advanced Research Weather Research and Forecast (WRF) (ARW) [3] has been shown to improve the prediction of sensible weather parameters in coastal regions [4][5}. In an extend study, [6] compared the MODIS SST composite product to the RTG SST analysis and evaluated forecast differences for a 6 month period from March through August 2007 over the Florida coastal regions. In a comparison to buoy data, they found that that the MODIS SST composites reduced the bias and standard deviation over that of the RTG data. These improvements led to significant changes in the initial and forecasted heat fluxes and the resulting surface temperature fields, wind patterns, and cloud distributions. They also showed that the MODIS composite SST product, produced for the Terra and Aqua satellite overpass times, captured a component of the diurnal cycle in SSTs not represented in the RTG or other one-a-day SST analyses. Failure to properly incorporate these effects in the WRF initialization cycle led to temperature biases in the resulting short term forecasts. The forecast impact was limited in some situations however, due to composite product inaccuracies brought about by data latency during periods of long-term cloud cover. This paper focuses on the forecast impact of an enhanced MODIS/AMSR-E composite SST product designed to reduce inaccuracies due data latency in the MODIS only composite product.

Munitions Detection Using Unmanned Underwater Vehicles Equipped with Advanced Sensors

DTIC Science & Technology

2012-06-29

buried target. The RTG is a small passive magnetic sensor using fluxgate magnetometers measuring 3- orthogonal magnetic-field vector components at 3...surveys. Figure 6 shows the RTG magnetic sensor in both an open (showing the fluxgate magnetometers ) and enclosed state (mode for integration onto...7.6 Real-time Tracking Gradiometer (RTG) System The RTG is a small passive magnetic sensor using fluxgate magnetometers measuring 3- orthogonal

Nucleotide Sequence of the blaRTG-2 (CARB-5) Gene and Phylogeny of a New Group of Carbenicillinases

PubMed Central

Choury, Daniele; Szajnert, Marie-France; Joly-Guillou, Marie-Laure; Azibi, Kemal; Delpech, Marc; Paul, Gérard

2000-01-01

We determined the nucleotide sequence of the bla gene for the Acinetobacter calcoaceticus β-lactamase previously described as CARB-5. Alignment of the deduced amino acid sequence with those of known β-lactamases revealed that CARB-5 possesses an RTG triad in box VII, as described for the Proteus mirabilis GN79 enzyme, instead of the RSG consensus characteristic of the other carbenicillinases. Phylogenetic studies showed that these RTG enzymes constitute a new, separate group, possibly ancestors of the carbenicillinase family. PMID:10722515

GPHS-RTGs in support of the Cassini RTG Program

NASA Astrophysics Data System (ADS)

1995-04-01

The technical progress achieved during the period 26 Sep. 1994 - 2 Apr. 1995 on Contract DE-AC03-91SF-18852 Radioisotope Thermoelectric Generators and Ancillary Activities is described herein. Monthly technical activity for the period 27 Feb. - 2 Apr. 1995 is included in this progress report. The report addresses tasks, including: spacecraft integration and liaison; engineering support; safety; qualified unicouple production; ETG fabrication, assembly, and test; ground support equipment; RTG shipping and launch support; designs, reviews, and mission applications; project management, quality assurance, reliability, contract changes, CAGO acquisition (operating funds), and CAGO maintenance and repair; and CAGO acquisition (capital funds).

SNAP 19 Viking Program. Bimonthly technical progress report, April-May 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-01-01

Monitoring and evaluation of Viking Lander 1 power system data continued. The RTG series power range as measured at the PCDA was 65 to 67 watts at finroot temperatures between 280/sup 0/F and 310/sup 0/F. The Mars Lander performance history of Viking 1 include both the minimum and maximum data for each of the SOL days. Final available power system data for Viking Lander 2 are shown. Typical SOL day cycles for mission day 1193 are presented. The RTG series power ranged from 69 to 70 watts at finroot temperatures between 270/sup 0/F and 300/sup 0/F. The Mars Lander performancemore » history for Viking 2 is shown. Power system performance data for Pioneer 10 and Pioneer Saturn (initially designated Pioneer 11) were monitored through the reporting period. After adjusting for the telemetry characteristics, the estimated RTG system net power was 114 watts for both Pioneer 10 and Pioneer Saturn.« less

Computer predictions of ground storage effects on performance of Galileo and ISPM generators

NASA Technical Reports Server (NTRS)

Chmielewski, A.

1983-01-01

Radioisotope Thermoelectric Generators (RTG) that will supply electrical power to the Galileo and International Solar Polar Mission (ISPM) spacecraft are exposed to several degradation mechanisms during the prolonged ground storage before launch. To assess the effect of storage on the RTG flight performance, a computer code has been developed which simulates all known degradation mechanisms that occur in an RTG during storage and flight. The modeling of these mechanisms and their impact on the RTG performance are discussed.

Applicability of STEM-RTG and High-Power SRG Power Systems to the Discovery and Scout Mission Capabilities Expansion (DSMCE) Study of ASRG-Based Missions

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.; Cataldo, Robert L.

2015-01-01

This study looks at the applicability of utilizing the Segmented Thermoelectric Modular Radioisotope Thermoelectric Generator (STEM-RTG) or a high-power radioisotope generator to replace the Advanced Stirling Radioisotope Generator (ASRG), which had been identified as the baseline power system for a number of planetary exploration mission studies. Nine different Discovery-Class missions were examined to determine the applicability of either the STEM-RTG or the high-power SRG power systems in replacing the ASRG. The nine missions covered exploration across the solar system and included orbiting spacecraft, landers and rovers. Based on the evaluation a ranking of the applicability of each alternate power system to the proposed missions was made.

Modular Isotopic Thermoelectric Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schock, Alfred

1981-01-01

Advanced RTG concepts utilizing improved thermoelectric materials and converter concepts are under study at Fairchild for DOE. The design described here is based on DOE's newly developed radioisotope heat source, and on an improved silicon-germanium material and multicouple converter module under development at Syncal. Fairchild's assignment was to combine the above into an attractive power system for use in space, and to assess the specific power and other attributes of that design.

Virological and immunological responses to raltegravir and dolutegravir in the gut-associated lymphoid tissue of HIV-infected men and women.

PubMed

Weber, Michael D; Andrews, Elizabeth; Prince, Heather A; Sykes, Craig; Rosen, Elias P; Bay, Camden; Shaheen, Nicholas J; Madanick, Ryan D; Dellon, Evan S; De Paris, Kristina; Nelson, Julie Ae; Gay, Cynthia L; Kashuba, Angela Dm

2018-05-01

Raltegravir (RTG) and dolutegravir (DTG) have different pharmacokinetic patterns in the gastrointestinal tract. To determine if this results in pharmacodynamic differences, we compared HIV RNA, HIV DNA, and immunological markers in gut-associated lymphoid tissue (GALT) of HIV-infected participants receiving RTG or DTG with tenofovir+emtricitabine (TDF/FTC). GALT specimens from the terminal ileum, splenic flexure, and rectum were obtained by colonoscopy at a single time point in 20 adults treated with RTG (n=10) or DTG (n=10) with HIV RNA <50 copies/mL. Flow cytometry, drug concentrations, and HIV RNA and DNA were analyzed in tissue. CD4/8 + T cells were tested for γδ TCR, and markers of T cell activation and exhaustion. Data are reported as median (Q1,Q3). 15 men and 5 women were enrolled. There was no difference in time since HIV diagnosis for those on RTG [9.5 (4-22) yr] and DTG [17 (1-24) yr] (p = 0.6), although time on RTG [5.4 (2.3-6.7) yr] was greater than DTG [1.0 (0.1-1.5) yr] (P < 0.001). Concentrations of RTG and DTG in rectal tissue (RT) were similar to previous reports: median tissue:plasma ratio was 11.25 for RTG and 0.44 for DTG. RNA:DNA ratios were [1.14 (0.18-5.10)] for the RTG group and [0.90 (0.30-18.87)] for the DTG group (p = 0.95). No differences (p ≥ 0.1) between CD4 + and CD8 + T cell markers were found. RTG produced higher tissue exposures than DTG, but no significant differences in GALT HIV RNA, DNA, or most immunologic markers were observed.

The long-term performance degradation of a radioisotope thermoelectric generator using silicon germanium

NASA Technical Reports Server (NTRS)

Stapfer, G.; Truscello, V. C.

1976-01-01

The successful utilization of a radioisotope thermoelectric generator (RTG) as the power source for spaceflight missions requires that the performance of such an RTG be predictable throughout the mission. Several mechanisms occur within the generator which tend to degrade the performance as a function of operating time. The impact which these mechanisms have on the available output power of an RTG depends primarily on such factors as time, temperature and self-limiting effects. The relative magnitudes, rates and temperature dependency of these various degradation mechanisms have been investigated separately by coupon experiments as well as 4-couple and 18-couple module experiments. This paper discusses the different individual mechanisms and summarizes their combined influence on the performance of an RTG. Also presented as part of the RTG long-term performance characteristics is the sensitivity of the available RTG output power to variations of the individual degradation mechanisms thus identifying the areas of greatest concern for a successful long-term mission.

Computational modeling of Radioisotope Thermoelectric Generators (RTG) for interplanetary and deep space travel

NASA Astrophysics Data System (ADS)

Nejat, Cyrus; Nejat, Narsis; Nejat, Najmeh

2014-06-01

This research project is part of Narsis Nejat Master of Science thesis project that it is done at Shiraz University. The goals of this research are to make a computer model to evaluate the thermal power, electrical power, amount of emitted/absorbed dose, and amount of emitted/absorbed dose rate for static Radioisotope Thermoelectric Generators (RTG)s that is include a comprehensive study of the types of RTG systems and in particular RTG’s fuel resulting from both natural and artificial isotopes, calculation of the permissible dose radioisotope selected from the above, and conceptual design modeling and comparison between several NASA made RTGs with the project computer model pointing out the strong and weakness points for using this model in nuclear industries for simulation. The heat is being converted to electricity by two major methods in RTGs: static conversion and dynamic conversion. The model that is created for this project is for RTGs that heat is being converted to electricity statically. The model approximates good results as being compared with SNAP-3, SNAP-19, MHW, and GPHS RTGs in terms of electrical power, efficiency, specific power, and types of the mission and amount of fuel mass that is required to accomplish the mission.

Thermoelectric Outer Planets Spacecraft (TOPS)

NASA Technical Reports Server (NTRS)

1973-01-01

The research and advanced development work is reported on a ballistic-mode, outer planet spacecraft using radioisotope thermoelectric generator (RTG) power. The Thermoelectric Outer Planet Spacecraft (TOPS) project was established to provide the advanced systems technology that would allow the realistic estimates of performance, cost, reliability, and scheduling that are required for an actual flight mission. A system design of the complete RTG-powered outer planet spacecraft was made; major technical innovations of certain hardware elements were designed, developed, and tested; and reliability and quality assurance concepts were developed for long-life requirements. At the conclusion of its active phase, the TOPS Project reached its principal objectives: a development and experience base was established for project definition, and for estimating cost, performance, and reliability; an understanding of system and subsystem capabilities for successful outer planets missions was achieved. The system design answered long-life requirements with massive redundancy, controlled by on-board analysis of spacecraft performance data.

SNAP 19 Pioneer F and G. Final Report

DOE R&D Accomplishments Database

1973-06-01

The generator developed for the Pioneer mission evolved from the SNAP 19 RTG`s launched aboard the NIMBUS III spacecraft. In order to satisfy the power requirements and environment of earth escape trajectory, significant modifications were made to the thermoelectric converter, heat source, and structural configuration. Specifically, a TAGS 2N thermoelectric couple was designed to provide higher efficiency and improved long term power performance, and the electrical circuitry was modified to yield very low magnetic field from current flow in the RTG. A new heat source was employed to satisfy operational requirements and its integration with the generator required alteration to the method of providing support to the fuel capsule.

Design of multihundredwatt DIPS for robotic space missions

NASA Technical Reports Server (NTRS)

Bents, D. J.; Geng, S. M.; Schreiber, J. G.; Withrow, C. A.; Schmitz, P. C.; Mccomas, Thomas J.

1991-01-01

Design of a dynamic isotope power system (DIPS) general purpose heat source (GPHS) and small free piston Stirling engine (FPSE) is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to SEI precursor missions. These are multihundredwatt missions. The incentive for any dynamic system is that it can save fuel which reduces cost and radiological hazard. However, unlike a conventional DIPS based on turbomachinery converions, the small Stirling DIPS can be advantageously scaled to multihundred watt unit size while preserving size and weight competitiveness with RTG's. Stirling conversion extends the range where dynamic systems are competitive to hundreds of watts (a power range not previously considered for dynamic systems). The challenge of course is to demonstrate reliability similar to RTG experience. Since the competative potential of FPSE as an isotope converter was first identified, work has focused on the feasibility of directly integrating GPHS with the Stirling heater head. Extensive thermal modeling of various radiatively coupled heat source/heater head geometries were performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within safe operating limits under all conditions including shutdown of one engine. Based on these results, preliminary characterizations of multihundred watt units were established.

So What's an RTG and Are They Safe?

NASA Technical Reports Server (NTRS)

Barret, Chris; Hughes, R. W. (Technical Monitor)

2001-01-01

When one considers space missions to the outer edges of our solar system and far beyond, our sun cannot be relied on to produce the required spacecraft (s/c) power. Solar energy diminishes as the square of the distance from the Sun. At Mars it is only 43% of that at earth. At Jupiter, it falls off to only 3.6% of Earth's. By the time we get out to Pluto, solar energy is only .066% what it is on Earth. Beyond the orbit of Mars, it is not practical to depend on solar power for a s/c. However, the farther out we go the more power we need to heat the s/c and to transmit data back to Earth over the long distances. On Earth, knowledge is power. In the outer solar system, power is knowledge. Solar arrays only operate at 19% efficiency, are very vulnerable to damage from radiation and temperature extremes, and cannot be used for even nearby missions that operate in extended darkness, or under the surface of a planet or moon. Twenty-six U.S. space missions, from the Transit to Cassini, have used radioisotope power systems and heater units to take s/c to the far reaches of our solar system and have demonstrated an outstanding record of safety and reliability. Radioisotope thermoelectric generators (RTG's) have proven to be safe, reliable, maintenance-free, and capable of providing both thermal and electrical power for decades under the harsh environments of deep space. RTG's have no problem operating in the high radiation belts of space, the extreme temperatures, or the severe dust storms of Mars, and they have proven to be the most reliable power source ever flown on U.S. s/c. For example, the two Pioneer s/c operated for more than two decades and the Voyager s/c may last for 40 years. RTG's are not nuclear reactors, they serve only as power generators and are not involved in the propulsion of the s/c. They operate on the principle of thermoelectric generation that converts heat directly into electricity, they have no moving parts, are extremely reliable, and have met or exceeded all safety and performance expectations. Federal laws and regulations require analysis and evaluation of the safety risks and any potential environmental impacts. Extensive safety testing of RTG's and RTG components has been performed by the U.S. Department of Energy (DOE) to demonstrate the ability to survive accidents related to Space Shuttle launches and assure that the systems would be safe under all accident conditions, including accidents at or near the launch pad or during orbital reentry. Many design improvements have been made over the four decades that RTG's have been flown on space missions. This paper outlines the operation and safety standards of RTG's and the advanced developments expected to be used on future deep space missions such as the Europa Orbiter, Pluto/Kuiper Express, Solar Probe, Europa Lander, and Titan Explorer missions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrell, P.C.

This SARP describes the RTG Transportation System Package, a Type B(U) packaging system that is used to transport an RTG or similar payload. The payload, which is included in this SARP, is a generic, enveloping payload that specifically encompasses the General Purpose Heat Source (GPHS) RTG payload. The package consists of two independent containment systems mounted on a shock isolation transport skid and transported within an exclusive-use trailer.

Environmental analysis of the logistics of agricultural products from roof top greenhouses in Mediterranean urban areas.

PubMed

Sanyé-Mengual, Esther; Cerón-Palma, Ileana; Oliver-Solà, Jordi; Montero, Juan Ignacio; Rieradevall, Joan

2013-01-15

As urban populations increase so does the amount of food transported to cities worldwide, and innovative agro-urban systems are being developed to integrate agricultural production into buildings; for example, by using roof top greenhouses (RTGs). This paper aims to quantify and compare, through a life cycle assessment, the environmental impact of the current linear supply system with a RTG system by using a case study for the production of tomatoes. The main results indicate that a change from the current linear system to the RTG system could result in a reduction, per kilogram of tomatoes (the functional unit), in the range of 44.4-75.5% for the different impact categories analysed, and savings of up to 73.5% in energy requirements. These savings are associated with re-utilisation of packaging systems (55.4-85.2%), minimisation of transport requirements (7.6-15.6%) and reduction of the loss of product during transportation and retail stages (7.3-37%). The RTG may become a strategic factor in the design of low-carbon cities in Mediterranean areas. Short-term implementation in the city of Barcelona could result in savings of 66.1 tonnes of CO₂ eq. ha(-1) when considering the global warming potential, and of 71.03 t ha(-1) when considering that the transformation from woodland to agricultural land is avoided. Copyright © 2012 Society of Chemical Industry.

RTGs on Transit

NASA Astrophysics Data System (ADS)

Dassoulas, John; McNutt, Ralph L.

2007-01-01

Transit, the US Navy's Navigation Satellite System was conceived at the Applied Physics Laboratory in 1957 by observing the Doppler shift while tracking Sputnik I. As spacecraft development proceeded there was concern about the ability of batteries to maintain the hermetic seal over a 5-year operational life requirement; therefore, alternate energy sources were investigated. The radioisotope thermoelectric generator (RTG) concept was pursued and resulted in the launch of SNAP 3s, providing partial power on both Transit 4A and 4B. SNAP 9s provided full power on three Transit 5BNs. All launches occurred in the early 1960s. When the U.S. conducted the high altitude nuclear test from Johnson Island, several spacecraft were lost due to artificial enhancement of charged particles in the Earth's magnetosphere resulting in rapid degradation of solar cell power production. This led to the decision to have both an RTG and Solar cell/battery design for Transit power systems; hence, a new RTG design, with a separable heat source and radiative coupling to the thermoelectric elements, was flown on TRIAD. This pioneering effort provided the impetus for future RTGs on interplanetary spacecraft. This paper describes the origin and purpose of the Transit program and provides details on the five satellites in that program that were powered by the first American RTGs used in space. The rationale and some of the challenges inherent in that use are also described.

Improved techniques for predicting spacecraft power

NASA Technical Reports Server (NTRS)

Chmielewski, A. B.

1987-01-01

Radioisotope Thermoelectric Generators (RTGs) are going to supply power for the NASA Galileo and Ulysses spacecraft now scheduled to be launched in 1989 and 1990. The duration of the Galileo mission is expected to be over 8 years. This brings the total RTG lifetime to 13 years. In 13 years, the RTG power drops more than 20 percent leaving a very small power margin over what is consumed by the spacecraft. Thus it is very important to accurately predict the RTG performance and be able to assess the magnitude of errors involved. The paper lists all the error sources involved in the RTG power predictions and describes a statistical method for calculating the tolerance.

Hunting Sea Mines with UUV-Based Magnetic and Electro-Optic Sensors

DTIC Science & Technology

2010-06-01

assembly of four 3-axis fluxgate magnetometers and (c) magnetometer package for underwater deployment in flooded body section. data are automatically...features the Real-time Tracking Gradiometer (RTG), which is a multi-channel tensor gradiometer using conventional fluxgate technology. Also in this...integrated together into a Bluefin12 AUV [5]. A. RTG Sensor Technology The RTG is a multi-channel tensor gradiometer using conventional fluxgate

Gravitational Lens: Deep Space Probe Design

DTIC Science & Technology

2012-03-01

Lieutenant, USAF Approved: Timothy Lawrence, Col, USAF (Chairman) Date Carl Hartsfield, Lt Col, USAF (Member) Date Marc G. Millis (Member) Date Abstract A...23 RTG Radioisotope Thermoelectric Generators . . . . . . . . . . . . . . . . . 26 EOL End of Life...26 ASRG Advanced Stirling Radioisotope Generator . . . . . . . . . . . . . . . . 26 GPHS

Final safety analysis report for the Galileo Mission: Volume 2: Book 1, Accident model document

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The Accident Model Document (AMD) is the second volume of the three volume Final Safety Analysis Report (FSAR) for the Galileo outer planetary space science mission. This mission employs Radioisotope Thermoelectric Generators (RTGs) as the prime electrical power sources for the spacecraft. Galileo will be launched into Earth orbit using the Space Shuttle and will use the Inertial Upper Stage (IUS) booster to place the spacecraft into an Earth escape trajectory. The RTG's employ silicon-germanium thermoelectric couples to produce electricity from the heat energy that results from the decay of the radioisotope fuel, Plutonium-238, used in the RTG heat source.more » The heat source configuration used in the RTG's is termed General Purpose Heat Source (GPHS), and the RTG's are designated GPHS-RTGs. The use of radioactive material in these missions necessitates evaluations of the radiological risks that may be encountered by launch complex personnel as well as by the Earth's general population resulting from postulated malfunctions or failures occurring in the mission operations. The FSAR presents the results of a rigorous safety assessment, including substantial analyses and testing, of the launch and deployment of the RTGs for the Galileo mission. This AMD is a summary of the potential accident and failure sequences which might result in fuel release, the analysis and testing methods employed, and the predicted source terms. Each source term consists of a quantity of fuel released, the location of release and the physical characteristics of the fuel released. Each source term has an associated probability of occurrence. 27 figs., 11 tabs.« less

Magnetic gradiometer for underwater detection applications

NASA Astrophysics Data System (ADS)

Kumar, S.; Skvoretz, D. C.; Moeller, C. R.; Ebbert, M. J.; Perry, A. R.; Ostrom, R. K.; Tzouris, A.; Bennett, S. L.; Czipott, P. V.; Sulzberger, G.; Allen, G. I.; Bono, J.; Clem, T. R.

2006-05-01

We have designed and constructed a magnetic gradiometer for underwater mine detection, location and tracking. The United States Naval Surface Warfare Center (NSWC PC) in Panama City, FL has conducted sea tests of the system using an unmanned underwater vehicle (UUV). The Real-Time Tracking Gradiometer (RTG) measures the magnetic field gradients caused by the presence of a mine in the Earth's magnetic field. These magnetic gradients can then be used to detect and locate a target with the UUV in motion. Such a platform can also be used for other applications, including the detection and tracking of vessels and divers for homeland (e.g., port) security and the detection of underwater pipelines. Data acquired by the RTG in sea tests is presented in this paper.

Influence of society for academic emergency medicine grant mechanisms on postaward academic productivity.

PubMed

Safdar, Basmah; Paradise, Summer A; McMillian, Melissa; Holmes, James F

2015-02-01

The Society for Academic Emergency Medicine (SAEM) provides research training grants, but the future productivity of award recipients and nonrecipients is unclear. The study objective was to assess the association of the two SAEM research training mechanisms with scholarly productivity and rates of subsequent funding between nonrecipients and recipients. A secondary goal was to evaluate the productivity metrics for fellows trained at the Institutional Research Training Grant (IRTG) programs. The authors surveyed all 2002 through 2011 Research Training Grant (RTG; n = 64) and Institutional Research Training Grant (IRTG; n = 38) applicants. RTG outcomes were federal funding as a principal investigator (PI) or co-PI using National Institutes of Health RePORTER and scholarly productivity using PubMed. IRTG outcomes were SAEM-approved research fellowships and National Heart, Lung and Blood Institute K12 training awards. Sites applying for or receiving the IRTG multiple times were only counted once. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated. Over 10 years, nine of 64 (14%) RTG and 10 of 38 (26%) IRTG applications were funded (two sites received multiple awards). Federal funding was obtained by seven of nine (78%) RTG recipients and 22 of 55 (40%) RTG nonrecipients (RR = 1.94, 95% CI = 1.21 to 3.13). All nine (100%, 95% CI = 72% to 100%) of RTG recipients had at least one manuscript, compared to 48 of the 55 (87%, 95% CI = 76% to 95%) nonrecipients. All nine (100%, 95% CI = 72% to 100%) RTG recipients remained in academics versus 44 of 55 (80%, 95% CI = 67% to 90%) nonrecipients. For the IRTG, four of seven awardees (57%, 95% CI = 18% to 90%) versus 0 of the 16 (0%, 95% CI = 0 to 17%) nonrecipients received National Heart, Lung and Blood Institute K12 awards (RR = 19.1, 95% CI = 1.16 to 314.0). Additionally, five of seven (71%, 95% CI = 29% to 96%) institutions became SAEM-approved fellowships compared to one of 16 (6%, 95% CI = 0 to 30%) nonrecipients (RR = 11.4, 95% CI = 1.61 to 80.7). SAEM RTG recipients were more likely to obtain federal funding postaward than nonrecipients. IRTG recipients were more likely to develop successful research training programs than nonrecipients. © 2015 by the Society for Academic Emergency Medicine.

Development of a New Generation of High-Temperature Thermoelectric Unicouples for Space Applications

NASA Technical Reports Server (NTRS)

Caillat, Thierry; Gogna, P.; Sakamoto, J.; Jewell, A.; Cheng, J.; Blair, R.; Fleurial, J. -P.; Ewell, R.

2006-01-01

RTG's have enabled surface and deep space missions since 1961: a) 26 flight missions without any RTG failures; and b) Mission durations in excess of 25 years. Future NASA missions require RTG s with high specific power and high efficiency, while retaining long life (> 14 years) and high reliability, (i.e. 6-8 W/kg, 10-15% efficiency). JPL in partnership with NASA-GRC, NASA-MSFC, DOE, Universities and Industry is developing advanced thermoelectric materials and converters to meet future NASA needs.

Analysis of tau post-translational modifications in rTg4510 mice, a model of tau pathology.

PubMed

Song, Lixin; Lu, Sherry X; Ouyang, Xuesong; Melchor, Jerry; Lee, Julie; Terracina, Giuseppe; Wang, Xiaohai; Hyde, Lynn; Hess, J Fred; Parker, Eric M; Zhang, Lili

2015-03-26

Microtubule associated protein tau is the major component of the neurofibrillary tangles (NFTs) found in the brains of patients with Alzheimer's disease and several other neurodegenerative diseases. Tau mutations are associated with frontotemperal dementia with parkinsonism on chromosome 17 (FTDP-17). rTg4510 mice overexpress human tau carrying the P301L FTDP-17 mutation and develop robust NFT-like pathology at 4-5 months of age. The current study is aimed at characterizing the rTg4510 mice to better understand the genesis of tau pathology and to better enable the use of this model in drug discovery efforts targeting tau pathology. Using a panel of immunoassays, we analyzed the age-dependent formation of pathological tau in rTg4510 mice and our data revealed a steady age-dependent accumulation of pathological tau in the insoluble fraction of brain homogenates. The pathological tau was associated with multiple post-translational modifications including aggregation, phosphorylation at a wide variety of sites, acetylation, ubiquitination and nitration. The change of most tau species reached statistical significance at the age of 16 weeks. There was a strong correlation between the different post-translationally modified tau species in this heterogeneous pool of pathological tau. Total tau in the cerebrospinal fluid (CSF) displayed a multiphasic temporal profile distinct from the steady accumulation of pathological tau in the brain. Female rTg4510 mice displayed significantly more aggressive accumulation of pathological tau in the brain and elevation of total tau in CSF than their male littermates. The immunoassays described here were used to generate the most comprehensive description of the changes in various tau species across the lifespan of the rTg4510 mouse model. The data indicate that development of tauopathy in rTg4510 mice involves the accumulation of a pool of pathological tau that carries multiple post-translational modifications, a process that can be detected well before the histological detection of NFTs. Therapeutic treatment targeting tau should therefore aim to reduce all tau species associated with the pathological tau pool rather than reduce specific post-translational modifications. There is still much to learn about CSF tau in physiological and pathological processes in order to use it as a translational biomarker in drug discovery.

Stirling Radioisotope Power System as an Alternative for NASAs Deep Space Missions

NASA Astrophysics Data System (ADS)

Shaltens, R. K.; Mason, L. S.; Schreiber, J. G.

2001-01-01

The NASA Glenn Research Center (GRC) and the Department of Energy (DOE) are developing a free-piston Stirling convertor for a Stirling Radioisotope Power System (SRPS) to provide on-board electric power for future NASA deep space missions. The SRPS currently being developed provides about 100 watts and reduces the amount of radioisotope fuel by a factor of four over conventional Radioisotope Thermoelectric Generators (RTG). The present SRPS design has a specific power of approximately 4 W/kg which is comparable to an RTG. GRC estimates for advanced versions of the SRPS with improved heat source integration, lightweight Stirling convertors, composite radiators, and chip-packaged controllers improves the specific mass to about 8 W/kg. Additional information is contained in the original extended abstract.

Preliminary assessment of rover power systems for the Mars Rover Sample Return Mission

NASA Technical Reports Server (NTRS)

Bents, D. J.

1989-01-01

Four isotope power system concepts were presented and compared on a common basis for application to on-board electrical prime power for an autonomous planetary rover vehicle. A representative design point corresponding to the Mars Rover Sample Return (MRSR) preliminary mission requirements (500 W) was selected for comparison purposes. All systems concepts utilize the General Purpose Heat Source (GPHS) isotope heat source developed by DOE. Two of the concepts employ thermoelectric (TE) conversion: one using the GPHS Radioisotope Thermoelectric Generator (RTG) used as a reference case, the other using an advanced RTG with improved thermoelectric materials. The other two concepts employed are dynamic isotope power systems (DIPS): one using a closed Brayton cycle (CBC) turboalternator, and the other using a free piston Stirling cycle engine/linear alternator (FPSE) with integrated heat source/heater head. Near-term technology levels have been assumed for concept characterization using component technology figure-of-merit values taken from the published literature. For example, the CBC characterization draws from the historical test database accumulated from space Brayton cycle subsystems and components from the NASA B engine through the mini-Brayton rotating unit. TE system performance is estimated from Voyager/multihundred Watt (MHW)-RTG flight experience through Mod-RTG performance estimates considering recent advances in TE materials under the DOD/DOE/NASA SP-100 and NASA Committee on Scientific and Technological Information programs. The Stirling DIPS system is characterized from scaled-down Space Power Demonstrator Engine (SPDE) data using the GPHS directly incorporated into the heater head. The characterization/comparison results presented here differ from previous comparison of isotope power (made for LEO applications) because of the elevated background temperature on the Martian surface compared to LEO, and the higher sensitivity of dynamic systems to elevated s

Quaternized Q-PEIPAAm-Based Antimicrobial Reverse Thermal Gel: A Potential for Surgical Incision Drapes.

PubMed

Bortot, Maria; Laughter, Melissa Ronni; Stein, Madia; Rocker, Adam; Patel, Vikas; Park, Daewon

2018-05-16

A quaternized reverse thermal gel (RTG) aimed at replacing current surgical incision drapes (SIDs) was designed and characterized. The antimicrobial efficacy of the quaternized RTG was analyzed using both in vitro and in vivo models and was compared to standard SIDs. Polymer characterization was completed using both nuclear magnetic resonance ( 1 H NMR) and lower critical solution temperature (LCST) analysis. Biocompatibility was assessed using a standard cell viability assay. The in vitro antimicrobial efficacy of the polymer was analyzed against four common bacteria species using a time-kill test. The in vivo antimicrobial efficacy of the polymer and standard SIDs were compared using a murine model aimed at mimicking surgical conditions. NMR confirmed the polymer structure and presence of quaternized groups and alkyl chains. The polymer displayed a LCST of 34 °C and a rapid rate of gelation, allowing stable gel formation when applied to skin. Once quaternized, the polymer displayed an increase in kill-rate of bacteria compared to unquaternized polymer. In experiments aimed at mimicking surgical conditions, the quaternized polymer showed statistically comparable bacteria-killing capacity to the standard SID and even surpassed the SID for killing capacity at various time points. A novel approach to replacing current SIDs was developed using an antimicrobial polymer system with RTG properties. The RTG properties of this polymer maintain a liquid state at low temperatures and a gel upon heating, allowing this polymer to form a tight coating when applied to skin. Furthermore, this polymer achieved excellent antimicrobial properties in both in vitro and in vivo models. With further optimization, this polymer system has the potential to replace and streamline presurgical patient preparations through its easy application and beneficial antimicrobial properties.

Validation Database Based Thermal Analysis of an Advanced RPS Concept

NASA Technical Reports Server (NTRS)

Balint, Tibor S.; Emis, Nickolas D.

2006-01-01

Advanced RPS concepts can be conceived, designed and assessed using high-end computational analysis tools. These predictions may provide an initial insight into the potential performance of these models, but verification and validation are necessary and required steps to gain confidence in the numerical analysis results. This paper discusses the findings from a numerical validation exercise for a small advanced RPS concept, based on a thermal analysis methodology developed at JPL and on a validation database obtained from experiments performed at Oregon State University. Both the numerical and experimental configurations utilized a single GPHS module enabled design, resembling a Mod-RTG concept. The analysis focused on operating and environmental conditions during the storage phase only. This validation exercise helped to refine key thermal analysis and modeling parameters, such as heat transfer coefficients, and conductivity and radiation heat transfer values. Improved understanding of the Mod-RTG concept through validation of the thermal model allows for future improvements to this power system concept.

Stratified Shear Flows In Pipe Geometries

NASA Astrophysics Data System (ADS)

Harabin, George; Camassa, Roberto; McLaughlin, Richard; UNC Joint Fluids Lab Team Team

2015-11-01

Exact and series solutions to the full Navier-Stokes equations coupled to the advection diffusion equation are investigated in tilted three-dimensional pipe geometries. Analytic techniques for studying the three-dimensional problem provide a means for tackling interesting questions such as the optimal domain for mass transport, and provide new avenues for experimental investigation of diffusion driven flows. Both static and time dependent solutions will be discussed. NSF RTG DMS-0943851, NSF RTG ARC-1025523, NSF DMS-1009750.

On thermal stress failure of the SNAP-19A RTG heat shield

NASA Technical Reports Server (NTRS)

Pitts, W. C.; Anderson, L. A.

1974-01-01

Results of a study on thermal stress problems in an amorphous graphite heat shield that is part of the launch-abort protect system for the SNAP-19A radio-isotope thermoelectric generators (RTG) that will be used on the Viking Mars Lander are presended. The first result is from a thermal stress analysis of a full-scale RTG heat source that failed to survive a suborbital entry flight test, possibly due to thermal stress failure. It was calculated that the maximum stress in the heat shield was only 50 percent of the ultimate strength of the material. To provide information on the stress failure criterion used for this calculation, some heat shield specimens were fractured under abort entry conditions in a plasma arc facility. It was found that in regions free of stress concentrations the POCO graphite heat shield material did fracture when the local stress reached the ultimate uniaxial stress of the material.

Small Stirling dynamic isotope power system for robotic space missions

NASA Technical Reports Server (NTRS)

Bents, D. J.

1992-01-01

The design of a multihundred-watt Dynamic Isotope Power System (DIPS), based on the U.S. Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE), is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. The incentive for any dynamic system is that it can save fuel and reduce costs and radiological hazard. Unlike DIPS based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled to multihundred-watt unit size while preserving size and mass competitiveness with RTG's. Stirling conversion extends the competitive range for dynamic systems down to a few hundred watts--a power level not previously considered for dynamic systems. The challenge for Stirling conversion will be to demonstrate reliability and life similar to RTG experience. Since the competitive potential of FPSE as an isotope converter was first identified, work has focused on feasibility of directly integrating GPHS with the Stirling heater head. Thermal modeling of various radiatively coupled heat source/heater head geometries has been performed using data furnished by the developers of FPSE and GPHS. The analysis indicates that, for the 1050 K heater head configurations considered, GPHS fuel clad temperatures remain within acceptable operating limits. Based on these results, preliminary characterizations of multihundred-watt units have been established.

Comparative studies of saxitoxin (STX) -induced cytotoxicity in Neuro-2a and RTG-2 cell lines: An explanation with respect to changes in ROS.

PubMed

Zhou, Zhongyuan; Tang, Xuexi; Chen, Hongmei; Wang, You

2018-02-01

Saxitoxin (STX), a paralytic shellfish toxin (PST) produced from toxic bloom-forming dinoflagellates, was selected to comparatively investigate the induction of cytotoxicity and apoptosis and a possible mechanism based on changes in the antioxidant defence system of two cellular strains: the mouse neuroblastoma cell line Neuro-2a and the rainbow trout fish cell line RTG-2. Increasing concentrations of STX (0-256 nM) presented little cytotoxic or apoptotic effects on the two cell lines. Measurements of cellular viability, lethal ratio and LDH leakage showed slight changes in Neuro-2a and RTG-2 cells (p > 0.05), and similar results were observed for cellular morphology and apoptotic rates. The contents of the main reactive oxygen species (ROS) components, superoxide anion (O 2 - ) and hydrogen peroxide (H 2 O 2 ), were markedly increased in Neuro-2a cell with STX exposure at middle (15 nM) and high (150 nM) concentrations (p < 0.05), and the simultaneous increase of the ratio of reduced/oxidized glutathione (GSH/GSSG) (p < 0.05) inferred the occurrence of oxidative stress. However, little difference was observed in all treated groups of RTG-2 cells. The activities of three antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), were significantly enhanced in Neuro-2a cells in the middle and high concentration groups (p < 0.05), while glutathione peroxidase (GPX) obviously decreased (p < 0.05) in all treated groups. Little change was found in RTG-2 cells with the same exposures. These results provided evidence that STX exposure altered the redox status of Neuro-2a cells and resulted in oxidative stress, but the same exposure exerted little effect on RTG-2 cells. Therefore, Neuro-2a cells are more sensitive than reproductive cells to STX exposure, and the antioxidant systems appears to be partly responsible for this differentiation response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rewiring AMPK and mitochondrial retrograde signaling for metabolic control of aging and histone acetylation in respiratory-defective cells.

PubMed

Friis, R Magnus N; Glaves, John Paul; Huan, Tao; Li, Liang; Sykes, Brian D; Schultz, Michael C

2014-04-24

Abnormal respiratory metabolism plays a role in numerous human disorders. We find that regulation of overall histone acetylation is perturbed in respiratory-incompetent (ρ(0)) yeast. Because histone acetylation is highly sensitive to acetyl-coenzyme A (acetyl-CoA) availability, we sought interventions that suppress this ρ(0) phenotype through reprogramming metabolism. Nutritional intervention studies led to the discovery that genetic coactivation of the mitochondrion-to-nucleus retrograde (RTG) response and the AMPK (Snf1) pathway prevents abnormal histone deacetylation in ρ(0) cells. Metabolic profiling of signaling mutants uncovered links between chromatin-dependent phenotypes of ρ(0) cells and metabolism of ATP, acetyl-CoA, glutathione, branched-chain amino acids, and the storage carbohydrate trehalose. Importantly, RTG/AMPK activation reprograms energy metabolism to increase the supply of acetyl-CoA to lysine acetyltransferases and extend the chronological lifespan of ρ(0) cells. Our results strengthen the framework for rational design of nutrient supplementation schemes and drug-discovery initiatives aimed at mimicking the therapeutic benefits of dietary interventions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Retigabine, a Kv7.2/Kv7.3-Channel Opener, Attenuates Drug-Induced Seizures in Knock-In Mice Harboring Kcnq2 Mutations.

PubMed

Ihara, Yukiko; Tomonoh, Yuko; Deshimaru, Masanobu; Zhang, Bo; Uchida, Taku; Ishii, Atsushi; Hirose, Shinichi

2016-01-01

The hetero-tetrameric voltage-gated potassium channel Kv7.2/Kv7.3, which is encoded by KCNQ2 and KCNQ3, plays an important role in limiting network excitability in the neonatal brain. Kv7.2/Kv7.3 dysfunction resulting from KCNQ2 mutations predominantly causes self-limited or benign epilepsy in neonates, but also causes early onset epileptic encephalopathy. Retigabine (RTG), a Kv7.2/ Kv7.3-channel opener, seems to be a rational antiepileptic drug for epilepsies caused by KCNQ2 mutations. We therefore evaluated the effects of RTG on seizures in two strains of knock-in mice harboring different Kcnq2 mutations, in comparison to the effects of phenobarbital (PB), which is the first-line antiepileptic drug for seizures in neonates. The subjects were heterozygous knock-in mice (Kcnq2Y284C/+ and Kcnq2A306T/+) bearing the Y284C or A306T Kcnq2 mutation, respectively, and their wild-type (WT) littermates, at 63-100 days of age. Seizures induced by intraperitoneal injection of kainic acid (KA, 12mg/kg) were recorded using a video-electroencephalography (EEG) monitoring system. Effects of RTG on KA-induced seizures of both strains of knock-in mice were assessed using seizure scores from a modified Racine's scale and compared with those of PB. The number and total duration of spike bursts on EEG and behaviors monitored by video recording were also used to evaluate the effects of RTG and PB. Both Kcnq2Y284C/+ and Kcnq2A306T/+ mice showed significantly more KA-induced seizures than WT mice. RTG significantly attenuated KA-induced seizure activities in both Kcnq2Y284C/+ and Kcnq2A306T/+ mice, and more markedly than PB. This is the first reported evidence of RTG ameliorating KA-induced seizures in knock-in mice bearing mutations of Kcnq2, with more marked effects than those observed with PB. RTG or other Kv7.2-channel openers may be considered as first-line antiepileptic treatments for epilepsies resulting from KCNQ2 mutations.

Underwater magnetic gradiometer for magnetic anomaly detection, localization, and tracking

NASA Astrophysics Data System (ADS)

Kumar, S.; Sulzberger, G.; Bono, J.; Skvoretz, D.; Allen, G. I.; Clem, T. R.; Ebbert, M.; Bennett, S. L.; Ostrom, R. K.; Tzouris, A.

2007-04-01

GE Security and the Naval Surface Warfare Center, Panama City (NSWC-PC) have collaborated to develop a magnetic gradiometer, called the Real-time Tracking Gradiometer or RTG that is mounted inside an unmanned underwater vehicle (UUV). The RTG is part of a buried mine hunting platform being developed by the United States Navy. The RTG has been successfully used to make test runs on mine-like targets buried off the coast of Florida. We will present a general description of the system and latest results describing system performance. This system can be also potentially used for other applications including those in the area of Homeland Security.

Development and Use of the Galileo and Ulysses Power Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, Gary L; Hemler, Richard J; Schock, Alfred

Paper presented at the 45th Congress of the International Astronautical Federation, October 1994. The Galileo mission to Jupiter and the Ulysses mission to explore the polar regions of the Sun required a new power source: the general-purpose heat source radioisotope thermoelectric generator (GPHS-RTG), the most powerful RTG yet flow. Four flight-qualified GPHS-RTGs were fabricated with one that is being used on Ulysses, two that are being used on Galileo and one that was a common spare (and is now available for the Cassini mission to Saturn). In addition, and Engineering Unit and a Qualification Unit were fabricated to qualify themore » design for space through rigorous ground tests. This paper summarizes the ground testing and performance predictions showing that the GPHS-RTGs have met and will continue to meet or exceed the performance requirements of the ongoing Galileo and Ulysses missions. There are two copies in the file.« less

Integration of the real-time tracking gradiometer (RTG) aboard the autonomous underwater vehicle (AUV) Morpheus

NASA Astrophysics Data System (ADS)

Allen, George I.; Matthews, Robert; Wynn, Michael

2001-10-01

In keeping with the Navy's policy to remove humans from harms way, the Autonomous Underwater Vehicle (AUV) is replacing human divers for many missions. The Advanced Marine Systems Lab at Florida Atlantic University (FAU) has developed a small, magnetically friendly, modular plastic AUV called Morpheus designed for coastal applications and especially suited for very shallow water (VSW) mine reconnaissance. Currently employed sensor technologies on AUVs have certain deficiencies and limitations when used across the wide gamut of naval targets and environments, and a strong requirement exists for a sensor or sensors to fill these niches. The Real-time Tracking Gradiometer (RTG) selected for this integration is truly such a niche sensor because its capabilities are not degraded by media interfaces or environmental conditions. It is an experimental prototype fluxgate magnetometer array developed by Quantum Magnetics for the Coastal Systems Station (CSS) and was designed to be man portable and self contained. While limited by physics in detection range, it is capable of detecting ferrous targets under the worst environmental conditions, even when the target is buried. While not having the range of sonar, the RTG does not respond to the false alarms that are indicated by sonar, and since it is capable of also providing range and bearing information, it provides an invaluable niche filling classification tool. The placing of any magnetic sensing system on a conventional AUV is a non-trivial problem. The standard AUV is designed around materials and components that were selected to maximize performance without regard to the magnetic properties of the materials used in its fabrication. To minimize the degradation of sensor performance caused by the platform, several steps must be taken. These include; the substitution of nonferrous components for ferrous, maximizing the separation between the sensor and magnetic field sources, minimizing current loops and using auxiliary current and field sensors capable of generating noise canceling signals. To maximize utility, the magnetic sensor systems should also provide range, bearing and magnetic target strength. While all data and results contained in this paper have been obtained with land-based testing, they are easily adapted to the underwater environment of the AUV. The RTG was recently attached to the Morpheus, and data collected with the unmodified Morpheus powered and undergoing simulated sea motion table. These tests indicate that integration, while not trivial, is indeed feasible, and work is continuing toward mounting the sensor internal to the AUV and implementing the required noise mitigation solutions.

[Cultivation of a permanent fish cell line in serum-free media special experiences with a cytotoxicity test for waste water samples

PubMed

Kohlpoth, Martin; Rusche, Brigitte

1997-01-01

The use of fetal calf serum (FCS) as standard medium additive for the cell cultivation must be regarded critically from the point of view of animal welfare as well as for scientific reasons and makes it necessary to look for alternatives. In the last years an in vitro cytotoxicity assay for the testing of industrial waste waters with the permanent fish cell line RTG-2 was established and pre-validated as an alternative to the fish test with the golden orfe. The application of FCS is also a special problem with regard to the testing of waste waters in a cytotoxicity test so that FCS-alternatives were tested. The RTG-2 cells were successfully adapted to the two solvents Basal Medium Supplement (BMS) and Ultroser-G (U-G) that are used to replace serum. The characterisation of these adapted cell lines showed no significant differences in growth rate, adhesion rate, viability and sensitivity to chemicals in comparison to the original RTG-2 cells. On the determination of the cytotoxicity of industrial waste waters the RTG-2 cells adapted to the BMS medium indicated a clearly higher toxicity of the waste water samples than the original RTG-2 cells. This result confirms the thesis that serum components react with waste water elements and thus change the bio-availability of toxic compounds.

Sfp1 and Rtg3 reciprocally modulate carbon source‐conditional stress adaptation in the pathogenic yeast Candida albicans

PubMed Central

Kastora, Stavroula L.; Herrero‐de‐Dios, Carmen; Avelar, Gabriela M.; Munro, Carol A.

2017-01-01

Summary The pathogenicity of the clinically important yeast, Candida albicans, is dependent on robust responses to host‐imposed stresses. These stress responses have generally been dissected in vitro at 30°C on artificial growth media that do not mimic host niches. Yet host inputs, such as changes in carbon source or temperature, are known to affect C. albicans stress adaptation. Therefore, we performed screens to identify novel regulators that promote stress resistance during growth on a physiologically relevant carboxylic acid and at elevated temperatures. These screens revealed that, under these ‘non‐standard’ growth conditions, numerous uncharacterised regulators are required for stress resistance in addition to the classical Hog1, Cap1 and Cta4 stress pathways. In particular, two transcription factors (Sfp1 and Rtg3) promote stress resistance in a reciprocal, carbon source‐conditional manner. SFP1 is induced in stressed glucose‐grown cells, whereas RTG3 is upregulated in stressed lactate‐grown cells. Rtg3 and Sfp1 regulate the expression of key stress genes such as CTA4, CAP1 and HOG1 in a carbon source‐dependent manner. These mechanisms underlie the stress sensitivity of C. albicans sfp1 cells during growth on glucose, and rtg3 cells on lactate. The data suggest that C. albicans exploits environmentally contingent regulatory mechanisms to retain stress resistance during host colonisation. PMID:28574606

Preliminary assessment of rover power systems for the Mars Rover Sample Return Mission

NASA Technical Reports Server (NTRS)

Bents, David J.

1989-01-01

Four isotope power system concepts were presented and compared on a common basis for application to on-board electrical prime power for an autonomous planetary rover vehicle. A representative design point corresponding to the Mars Rover Sample Return (MRSR) preliminary mission requirements (500 W) was selected for comparison purposes. All systems concepts utilize the General Purpose Heat Source (GPHS) isotope heat source developed by DOE. Two of the concepts employ thermoelectric (TE) conversion: one using the GPHS Radioisotope Thermoelectric Generator (RTG) used as a reference case, the other using an advanced RTG with improved thermoelectric materials. The other two concepts employed are dynamic isotope power systems (DIPS): one using a closed Brayton cycle (CBC) turboalternator, and the other using a free piston Stirling cycle engine/linear alternator (FPSE) with integrated heat source/heater head. Near term technology levels have been assumed for concept characterization using component technology figure-of-merit values taken from the published literature. For example, the CBC characterization draws from the historical test database accumulated from space Brayton cycle subsystems and components from the NASA B engine through the mini-Brayton rotating unit. TE system performance is estimated from Voyager/multihundred Watt (MHW)-RTG flight experience through Mod-RTG performance estimates considering recent advances in TE materials under the DOD/DOE/NASA SP-100 and NASA Committee on Scientific and Technological Information programs. The Stirling DIPS system is characterized from scaled-down Space Power Demonstrator Engine (SPDE) data using the GPHS directly incorporated into the heater head. The characterization/comparison results presented here differ from previous comparison of isotope power (made for Low Earth Orbit (LEO) applications) because of the elevated background temperature on the Martian surface compared to LEO, and the higher sensitivity of dynamic systems to elevated sink temperature. The mass advantage of dynamic systems is significantly reduced for this application due to Mars' elevated background temperature.

Safety and tolerability of different titration rates of retigabine (ezogabine) in patients with partial-onset seizures.

PubMed

Biton, Victor; Gil-Nagel, Antonio; Brodie, Martin J; Derossett, Sarah E; Nohria, Virinder

2013-11-01

Retigabine (RTG; international nonproprietary name)/ezogabine (EZG; US adopted name) is an antiepileptic drug (AED) that prolongs neuronal voltage-gated potassium-channel KCNQ2-5 (Kv 7.2-7.5) opening. This double-blind study evaluated different RTG/EZG dose-titration rates. Patients (N=73) with partial-onset seizures receiving concomitant AEDs were randomized to one of three titration groups, all of which were initiated at RTG/EZG 300mg/day divided into three equal doses. Fast-, medium-, and slow-titration groups received dose increments of 150mg/day every 2, 4, and 7 days, respectively, achieving the target dose of 1200mg/day after 13, 25, and 43 days, respectively. Safety assessments were performed throughout. Discontinuation rates due to treatment-emergent adverse events (TEAEs) were numerically higher in the fast- (10/23) and medium- (7/22) titration groups than in the slow-titration group (3/23) but statistical significance was achieved only for the high-titration group compared with the low-titration group (p=0.024). Stratified analysis, with concomitant AEDs divided into enzyme inducers (carbamazepine, phenytoin, oxcarbazepine) or noninducers, showed that the risk of discontinuation due primarily to TEAEs was significantly higher in the fast- (p=0.010) but not in the medium-titration group (p=0.078) when compared with the slow-titration group. Overall, the slow-titration rate appeared to be best tolerated and was used in further efficacy and safety studies with RTG/EZG. Copyright © 2013 Elsevier B.V. All rights reserved.

Progressive Pathological Changes in Neurochemical Profile of the Hippocampus and Early Changes in the Olfactory Bulbs of Tau Transgenic Mice (rTg4510).

PubMed

Kim, Jieun; Choi, In-Young; Duff, Karen E; Lee, Phil

2017-06-01

Tauopathies such as Alzheimer's disease and frontotemporal lobe degeneration (FTLD-tau) dementia, characterized by pathologic aggregation of the microtubule-associated tau protein and formation of neurofibrillary tangles, have been linked to neurodegeneration and cognitive decline. The early detection of cerebral abnormalities and the identification of biological contributors to the continuous pathologic processes of neurodegeneration in tauopathies critically hinge on sensitive and reliable measures of biomarkers in the living brain. In this study, we measured alterations in a number of key neurochemicals associated with tauopathy-induced neurodegeneration in the hippocampus and the olfactory bulbs of a transgenic mouse model of FTLD-tauopathy, line rTg4510, using in vivo 1 H magnetic resonance spectroscopy at 9.4 T. The rTg4510 line develops tauopathy at a young age (4-5 months), reaching a severe stage by 8-12 months of age. Longitudinal measurement of neurochemical concentrations in the hippocampus of mice from 5 to 12 months of age showed significant progressive changes with distinctive disease staging patterns including N-acetylaspartate, myo-inositol, γ-aminobutyric acid, glutathione and glutamine. The accompanying hippocampal volume loss measured using magnetic resonance imaging showed significant correlation (p < 0.01) with neurochemical measurements. Neurochemical alterations in the olfactory bulbs were more pronounced than those in the hippocampus in rTg4510 mice. These results demonstrate progressive neuropathology in the mouse model and provide potential biomarkers of early neuropathological events and effective noninvasive monitoring of the disease progression and treatment efficacy, which can be easily translated to clinical studies.

Progressive Functional Impairments of Hippocampal Neurons in a Tauopathy Mouse Model

PubMed Central

Ciupek, Sarah M.; Cheng, Jingheng; Ali, Yousuf O.; Lu, Hui-Chen

2015-01-01

The age-dependent progression of tau pathology is a major characteristic of tauopathies, including Alzheimer's disease (AD), and plays an important role in the behavioral phenotypes of AD, including memory deficits. Despite extensive molecular and cellular studies on tau pathology, it remains to be determined how it alters the neural circuit functions underlying learning and memory in vivo. In rTg4510 mice, a Tau-P301L tauopathy model, hippocampal place fields that support spatial memories are abnormal at old age (7–9 months) when tau tangles and neurodegeneration are extensive. However, it is unclear how the abnormality in the hippocampal circuit function arises and progresses with the age-dependent progression of tau pathology. Here we show that in young (2–4 months of age) rTg4510 mice, place fields of hippocampal CA1 cells are largely normal, with only subtle differences from those of age-matched wild-type control mice. Second, high-frequency ripple oscillations of local field potentials in the hippocampal CA1 area are significantly reduced in young rTg4510 mice, and even further deteriorated in old rTg4510 mice. The ripple reduction is associated with less bursty firing and altered synchrony of CA1 cells. Together, the data indicate that deficits in ripples and neuronal synchronization occur before overt deficits in place fields in these mice. The results reveal a tau-pathology-induced progression of hippocampal functional changes in vivo. PMID:26019329

Restricted growth of U-type infectious haematopoietic necrosis virus (IHNV) in rainbow trout cells may be linked to casein kinase II activity

USGS Publications Warehouse

Park, J.-W.; Moon, C.H.; Harmache, A.; Wargo, A.R.; Purcell, M.K.; Bremont, M.; Kurath, G.

2011-01-01

Previously, we demonstrated that a representative M genogroup type strain of infectious haematopoietic necrosis virus (IHNV) from rainbow trout grows well in rainbow trout-derived RTG-2 cells, but a U genogroup type strain from sockeye salmon has restricted growth, associated with reduced genome replication and mRNA transcription. Here, we analysed further the mechanisms for this growth restriction of U-type IHNV in RTG-2 cells, using strategies that assessed differences in viral genes, host immune regulation and phosphorylation. To determine whether the viral glycoprotein (G) or non-virion (NV) protein was responsible for the growth restriction, four recombinant IHNV viruses were generated in which the G gene of an infectious IHNV clone was replaced by the G gene of U- or M-type IHNV and the NV gene was replaced by NV of U- or M-type IHNV. There was no significant difference in the growth of these recombinants in RTG-2 cells, indicating that G and NV proteins are not major factors responsible for the differential growth of the U- and M-type strains. Poly I:C pretreatment of RTG-2 cells suppressed the growth of both U- and M-type IHNV, although the M virus continued to replicate at a reduced level. Both viruses induced type 1 interferon (IFN1) and the IFN1 stimulated gene Mx1, but the expression levels in M-infected cells were significantly higher than in U-infected cells and an inhibitor of the IFN1-inducible protein kinase PKR, 2-aminopurine (2-AP), did not affect the growth of U- or M-type IHNV in RTG-2 cells. These data did not indicate a role for the IFN1 system in the restricted growth of U-type IHNV in RTG-2 cells. Prediction of kinase-specific phosphorylation sites in the viral phosphoprotein (P) using the NetPhosK program revealed differences between U- and M-type P genes at five phosphorylation sites. Pretreatment of RTG-2 cells with a PKC inhibitor or a p38MAPK inhibitor did not affect the growth of the U- and M-type viruses. However, 100 μm of the casein kinase II (CKII) inhibitor, 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole (DRB), reduced the titre of the U type 8.3-fold at 24 h post-infection. In contrast, 100 μm of the CKII inhibitor reduced the titre of the M type only 1.3-fold at 48 h post-infection. Our data suggest that the different growth of U- and M-type IHNV in RTG-2 cells may be linked to a differential requirement for cellular protein kinases such as CKII for their growth.

The Sensorless Pore Module of Voltage-gated K+ Channel Family 7 Embodies the Target Site for the Anticonvulsant Retigabine.

PubMed

Syeda, Ruhma; Santos, Jose S; Montal, Mauricio

2016-02-05

KCNQ (voltage-gated K(+) channel family 7 (Kv7)) channels control cellular excitability and underlie the K(+) current sensitive to muscarinic receptor signaling (the M current) in sympathetic neurons. Here we show that the novel anti-epileptic drug retigabine (RTG) modulates channel function of pore-only modules (PMs) of the human Kv7.2 and Kv7.3 homomeric channels and of Kv7.2/3 heteromeric channels by prolonging the residence time in the open state. In addition, the Kv7 channel PMs are shown to recapitulate the single-channel permeation and pharmacological specificity characteristics of the corresponding full-length proteins in their native cellular context. A mutation (W265L) in the reconstituted Kv7.3 PM renders the channel insensitive to RTG and favors the conductive conformation of the PM, in agreement to what is observed when the Kv7.3 mutant is heterologously expressed. On the basis of the new findings and homology models of the closed and open conformations of the Kv7.3 PM, we propose a structural mechanism for the gating of the Kv7.3 PM and for the site of action of RTG as a Kv7.2/Kv7.3 K(+) current activator. The results validate the modular design of human Kv channels and highlight the PM as a high-fidelity target for drug screening of Kv channels. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

The Sensorless Pore Module of Voltage-gated K+ Channel Family 7 Embodies the Target Site for the Anticonvulsant Retigabine*

PubMed Central

Syeda, Ruhma; Santos, Jose S.; Montal, Mauricio

2016-01-01

KCNQ (voltage-gated K+ channel family 7 (Kv7)) channels control cellular excitability and underlie the K+ current sensitive to muscarinic receptor signaling (the M current) in sympathetic neurons. Here we show that the novel anti-epileptic drug retigabine (RTG) modulates channel function of pore-only modules (PMs) of the human Kv7.2 and Kv7.3 homomeric channels and of Kv7.2/3 heteromeric channels by prolonging the residence time in the open state. In addition, the Kv7 channel PMs are shown to recapitulate the single-channel permeation and pharmacological specificity characteristics of the corresponding full-length proteins in their native cellular context. A mutation (W265L) in the reconstituted Kv7.3 PM renders the channel insensitive to RTG and favors the conductive conformation of the PM, in agreement to what is observed when the Kv7.3 mutant is heterologously expressed. On the basis of the new findings and homology models of the closed and open conformations of the Kv7.3 PM, we propose a structural mechanism for the gating of the Kv7.3 PM and for the site of action of RTG as a Kv7.2/Kv7.3 K+ current activator. The results validate the modular design of human Kv channels and highlight the PM as a high-fidelity target for drug screening of Kv channels. PMID:26627826

Technical, analytical and computer support

NASA Technical Reports Server (NTRS)

1972-01-01

The development of a rigorous mathematical model for the design and performance analysis of cylindrical silicon-germanium thermoelectric generators is reported that consists of two parts, a steady-state (static) and a transient (dynamic) part. The material study task involves the definition and implementation of a material study that aims to experimentally characterize the long term behavior of the thermoelectric properties of silicon-germanium alloys as a function of temperature. Analytical and experimental efforts are aimed at the determination of the sublimation characteristics of silicon germanium alloys and the study of sublimation effects on RTG performance. Studies are also performed on a variety of specific topics on thermoelectric energy conversion.

Bone Density, Balance and Quality of Life of Postmenopausal Women Taking Alendronate Participating in Different Physical Activity Programs

PubMed Central

Borba-Pinheiro, Cláudio Joaquim; de Alencar Carvalho, Mauro César Gurgel; da Silva, Nádia Souza Lima; Drigo, Alexandre Janotta; Bezerra, Jani Cléria Pereira; Dantas, Estélio Henrique Martin

2010-01-01

Background: The objective of this study was to determine the effects of different physical activity (PA) programs on bone density, balance and quality of Life of postmenopausaL women taking concomitant aLendronate. A quasi-experimental study was conducted with 35 volunteers divided into four groups: practitioners of resistance training (RTG, n = 9, 49.8±4.2 years), judo (JUG, n= 11, 52.2 ±5.3 years), water aerobics (WAG, n = 8, 57.1 ±7.4 years) and the control group (CG, n = 7, 53.8±4.4 years). Methods: The following assessment tools were used: bone mineral density (BMD) measured by dual X-ray absorptiometry of the spine and proximal femur, the ‘Osteoporosis Assessment Questionnaire’ (OPAQ) and the ‘Static Balance Test with Visual Control’. The physical activities were planned for 12 months in cycles with different intensities. A two-way analysis of variance (ANOVA) was used for analysis between groups, and a Scheffe post-hoc test was used for multiple comparisons. Results: The multiple comparisons results showed that the RTG and JUG groups were significantly more efficient in the variables studied, including: Lumbar BMD (Δ% = 6.8%, p = 0.001), balance (Δ% = 21.4%, p = 0.01), OPAQ (Δ% = 9.1%, p = 0.005) and Lumbar BMD (Δ% = 6.4%, p = 0.003), balance (Δ% = U%, p = 0.02) and OPAQ (Δ% = 16.8%, p =0.000) compared with the CG. Furthermore, the RTG (Δ% = 4.8%, p =0.02) was significantly better than the WAG for the neck of femur BMD, and the JUG (Δ% = 16.8, p = 0.0003) also demonstrated superiority to the WAG in the OPAQ. Conclusions: The physical activities studied appear to improve BMD, balance and quality of Life of postmenopausaL women taking a bisphosphonate. In this small sample, the RTG and the JUG groups were superior to the other groups. PMID:22870446

Fluorine-19 magnetic resonance imaging probe for the detection of tau pathology in female rTg4510 mice.

PubMed

Yanagisawa, Daijiro; Ibrahim, Nor Faeizah; Taguchi, Hiroyasu; Morikawa, Shigehiro; Kato, Tomoko; Hirao, Koichi; Shirai, Nobuaki; Sogabe, Takayuki; Tooyama, Ikuo

2018-05-01

Aggregation of tau into neurofibrillary tangles (NFTs) is characteristic of tauopathies, including Alzheimer's disease. Recent advances in tau imaging have attracted much attention because of its potential contributions to early diagnosis and monitoring of disease progress. Fluorine-19 magnetic resonance imaging ( 19 F-MRI) may be extremely useful for tau imaging once a high-quality probe has been formulated. In this investigation, a novel fluorine-19-labeling compound has been developed as a probe for tau imaging using 19 F-MRI. This compound is a buta-1,3-diene derivative with a polyethylene glycol side chain bearing a CF 3 group and is known as Shiga-X35. Female rTg4510 mice (a mouse model of tauopathy) and wild-type mice were intravenously injected with Shiga-X35, and magnetic resonance imaging of each mouse's head was conducted in a 7.0-T horizontal-bore magnetic resonance scanner. The 19 F-MRI in rTg4510 mice showed an intense signal in the forebrain region. Analysis of the signal intensity in the forebrain region revealed a significant accumulation of fluorine-19 magnetic resonance signal in the rTg4510 mice compared with the wild-type mice. Histological analysis showed fluorescent signals of Shiga-X35 binding to the NFTs in the brain sections of rTg4510 mice. Data collected as part of this investigation indicate that 19 F-MRI using Shiga-X35 could be a promising tool to evaluate tau pathology in the brain. © 2017 Wiley Periodicals, Inc.

SNAP 19 Viking Program. Bimonthly technical progress report, October 1979-November 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-12-01

Monitoring and evaluation of Viking 1 Lander power system data continued. The RTG series power range as measured at the PCDA was 65 to 68 watts at fin root temperatures between 280/sup 0/F and 310/sup 0/F. The Mars landed performance history of Viking 1 include both the minimum and maximum data for each of the SOL days. Monitoring and evaluation of Viking 2 Lander power system data continued. The RTG series power range as measured at the PCDA was 71 to 72 watts at fin root temperatures between 230/sup 0/F and 260/sup 0/F. The Mars landed performance history of Vikingmore » 2 include both the minimum and maximum data for each of the SOL days. The performance of both power systems continues to be very satisfactory. Power system performance data for Pioneer 10 and Pioneer 11 spacecraft were monitored through the reporting period. The estimated RTG system net power was 116 watts for Pioneer 10 and 118 watts for Pioneer Saturn. The September 1 encounter with Saturn appears to have had no deleterious effect on the RTG's of the spacecraft power system. The telemetry signals from both spacecrafts remain satisfactory.« less

Termination of aquired and natural immunological tolerance with specific complexes

PubMed Central

1975-01-01

It was possible to terminate the induced unresponsive state to bovine serum albumin (BSA) and the natural unresponsive state to autologous thyroglobulin in rabbits (RTg) by immunization with complexes composed of heterologous cross-reacting antibody and the tolerated antigens. The unresponsive state was terminated in rabbits made unresponsive by neonatal injections of BSA and then 3 mo later injected with complexes composed of BSA and guinea pig antihuman serum albumin. This termination was manifested by the presence of anti-BSA plaque-forming cells. Similarly, the natural unresponsive state was terminated in adult rabbits injected with complexes between RTg and guinea pig antibovine thyroglobulin (BTg) in that thyroid lesions and circulating anti-RTg were produced. The results can be best explained by the presence of unresponsive T cells and competent B cells, where the guinea pig gamma globulin (antibody) activates T cells specific for the guinea pig gamma globulin portion of the complexes and thus permits stimulation of B cells competent to the exposed determinants of the tolerated (BSA or RTg) portion of the complexes. The detailed mechanism for the activation of B cells in tolerant animals is discussed. PMID:1095680

KSC-10941f07

NASA Image and Video Library

1997-05-27

Jet Propulsion Laboratory (JPL) technicians finish mounting a thermal model of a radioisotope thermoelectric generator (RTG) on the installation cart which will be used to install the RTG in the Cassini spacecraft at Level 14 of Space Launch Complex 40, Cape Canaveral Air Station. The technicians use the thermal model to practice installation procedures. The three actual RTGs which will provide electrical power to Cassini on its 6.7-mile trip to the Saturnian system, and during its four-year mission at Saturn, are being tested and monitored in the Radioisotope Thermoelectric Generator Storage Building in KSC's Industrial Area. The RTGs use heat from the natural decay of plutonium to generate electric power. RTGs enable spacecraft to operate far from the Sun where solar power systems are not feasible. The RTGs on Cassini are of the same design as those flying on the already deployed Galileo and Ulysses spacecraft. The Cassini mission is targeted for an October 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL

Reach-to-grasp movement as a minimization process.

PubMed

Yang, Fang; Feldman, Anatol G

2010-02-01

It is known that hand transport and grasping are functionally different but spatially coordinated components of reach-to-grasp (RTG) movements. As an extension of this notion, we suggested that body segments involved in RTG movements are controlled as a coherent ensemble by a global minimization process associated with the necessity for the hand to reach the motor goal. Different RTG components emerge following this process without pre-programming. Specifically, the minimization process may result from the tendency of neuromuscular elements to diminish the spatial gap between the actual arm-hand configuration and its virtual (referent) configuration specified by the brain. The referent configuration is specified depending on the object shape, localization, and orientation. Since the minimization process is gradual, it can be interrupted and resumed following mechanical perturbations, at any phase during RTG movements, including hand closure. To test this prediction of the minimization hypothesis, we asked subjects to reach and grasp a cube placed within the reach of the arm. Vision was prevented during movement until the hand returned to its initial position. As predicted, by arresting wrist motion at different points of hand transport in randomly selected trials, it was possible to halt changes in hand aperture at any phase, not only during hand opening but also during hand closure. Aperture changes resumed soon after the wrist was released. Another test of the minimization hypothesis was made in RTG movements to an object placed beyond the reach of the arm. It has previously been shown (Rossi et al. in J Physiol 538:659-671, 2002) that in such movements, the trunk motion begins to contribute to hand transport only after a critical phase when the shifts in the referent arm configuration have finished (at about the time when hand velocity is maximal). The minimization rule suggests that when the virtual contribution of the arm to hand transport is completed, guidance of hand aperture switches from the arm to the trunk control system. As a consequence, hand aperture changes can be halted by trunk arrests but only if they are prolonged beyond a critical phase. As predicted, hand transport and hand aperture in RTG movements beyond the reach of the arm were halted by trunk arrests only if they were prolonged beyond the time of peak hand velocity. Hand motion and aperture changes resumed only when the trunk was released. While supporting the minimization hypothesis, our findings imply that not only spatial but also temporal characteristics of each component, including the shortest, hand closure component of RTG movements, are controlled in a flexible, task-specific way.

Cassini RTG acceptance test results and RTG performance on Galileo and Ulysses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, C.E.; Klee, P.M.

Flight acceptance testing has been completed for the RTGs to be used on the Cassini spacecraft which is scheduled for an October 6, 1997 launch to Saturn. The acceptance test program includes vibration tests, magnetic field measurements, mass properties (weight and c.g.) and thermal vacuum test. This paper presents the thermal vacuum test results. Three RTGs are to be used, F-2, F-6, and F-7. F-5 is the backup RTG, as it was for the Galileo and Ulysses missions launched in 1989 and 1990, respectively. RTG performance measured during the thermal vacuum tests carried out at the Mound Laboratory facility metmore » all specification requirements. Beginning of mission (BOM) and end of mission (EOM) power predictions have been made based on these tests results. BOM power is predicted to be 888 watts compared to the minimum requirement of 826 watts. Degradation models predict the EOM power after 16 years is to be 640 watts compared to a minimum requirement of 596 watts. Results of small scale module tests are also shown. The modules contain couples from the qualification and flight production runs. The tests have exceeded 28,000 hours (3.2 years) and are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. All test results indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of over 5% are predicted. Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Telemetry data are also shown for the RTG on the Ulysses spacecraft which completed its planned mission in 1995 and is now in the extended mission.« less

Cassini RTG acceptance test results and RTG performance on Galileo and Ulysses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, C.E.; Klee, P.M.

Flight acceptance testing has been completed for the RTGs to be used on the Cassini spacecraft which is scheduled for an October 6, 1997 launch to Saturn. The acceptance test program includes vibration tests, magnetic field measurements, properties (weight and c.g.) and thermal vacuum test. This paper presents The thermal vacuum test results. Three RTGs are to be used, F-2, F-6, and F-7. F-5 is tile back-up RTG, as it was for the Galileo and Ulysses missions launched in 1989 and 1990, respectively. RTG performance measured during the thermal vacuum tests carried out at die Mound Laboratory facility met allmore » specification requirements. Beginning of mission (BOM) and end of mission (EOM) power predictions have been made based on than tests results. BOM power is predicted to be 888 watts compared to the minimum requirement of 826 watts. Degradation models predict the EOM power after 16 years is to be 640 watts compared to a minimum requirement of 596 watts. Results of small scale module tests are also showing. The modules contain couples from the qualification and flight production runs. The tests have exceeded 28,000 hours (3.2 years) and are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. All test results indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of over five percent are predicted. Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Telemetry data are also shown for the RTG on the Ulysses spacecraft which completed its planned mission in 1995 and is now in the extended mission.« less

Cassini RTG Acceptance Test Results and RTG Performance on Galileo and Ulysses

DOE R&D Accomplishments Database

Kelly, C. E.; Klee, P. M.

1997-06-01

Flight acceptance testing has been completed for the RTGs to be used on the Cassini spacecraft which is scheduled for an October 6, 1997 launch to Saturn. The acceptance test program includes vibration tests, magnetic field measurements, properties (weight and c.g.) and thermal vacuum test. This paper presents The thermal vacuum test results. Three RTGs are to be used, F 2, F 6, and F 7. F 5 is tile back up RTG, as it was for the Galileo and Ulysses missions launched in 1989 and 1990, respectively. RTG performance measured during the thermal vacuum tests carried out at die Mound Laboratory facility met all specification requirements. Beginning of mission (BOM) and end of mission (EOM) power predictions have been made based on than tests results. BOM power is predicted to be 888 watts compared to the minimum requirement of 826 watts. Degradation models predict the EOM power after 16 years is to be 640 watts compared to a minimum requirement of 596 watts. Results of small scale module tests are also showing. The modules contain couples from the qualification and flight production runs. The tests have exceeded 28,000 hours (3.2 years) and are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. All test results indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of over five percent are predicted. Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Telemetry data are also shown for the RTG on the Ulysses spacecraft which completed its planned mission in 1995 and is now in the extended mission.

An evaluation of some special techniques for nuclear waste disposal in space

NASA Technical Reports Server (NTRS)

Mackay, J. S.

1973-01-01

A preliminary examination is reported of several special ways for space disposal of nuclear waste material which utilize the radioactive heat in the waste to assist in the propulsion for deep space trajectories. These include use of the wastes in a thermoelectric generator (RTG) which operates an electric propulsion device and a radioisotope - thermal thruster which uses hydrogen or ammonia as the propellant. These propulsive devices are compared to the space tug and the space tug/solar electric propulsion combination for disposal of waste on a solar system escape trajectory. Such comparisons indicate that the waste-RTG approach has considerable potential provided the combined specific mass of the waste container - RTG system does not exceed approximately 150 kg/kw sub e. Several exploratory numerical calculations have been made for high earth orbit and Earth escape destinations.

Imaging the accumulation and suppression of tau pathology using multiparametric MRI

PubMed Central

Holmes, Holly E.; Colgan, Niall; Ismail, Ozama; Ma, Da; Powell, Nick M.; O'Callaghan, James M.; Harrison, Ian F.; Johnson, Ross A.; Murray, Tracey K.; Ahmed, Zeshan; Heggenes, Morton; Fisher, Alice; Cardoso, M.J.; Modat, Marc; Walker-Samuel, Simon; Fisher, Elizabeth M.C.; Ourselin, Sebastien; O'Neill, Michael J.; Wells, Jack A.; Collins, Emily C.; Lythgoe, Mark F.

2016-01-01

Mouse models of Alzheimer's disease have served as valuable tools for investigating pathogenic mechanisms relating to neurodegeneration, including tau-mediated and neurofibrillary tangle pathology—a major hallmark of the disease. In this work, we have used multiparametric magnetic resonance imaging (MRI) in a longitudinal study of neurodegeneration in the rTg4510 mouse model of tauopathy, a subset of which were treated with doxycycline at different time points to suppress the tau transgene. Using this paradigm, we investigated the sensitivity of multiparametric MRI to both the accumulation and suppression of pathologic tau. Tau-related atrophy was discernible from 5.5 months within the cortex and hippocampus. We observed markedly less atrophy in the treated rTg4510 mice, which was enhanced after doxycycline intervention from 3.5 months. We also observed differences in amide proton transfer, cerebral blood flow, and diffusion tensor imaging parameters in the rTg4510 mice, which were significantly less altered after doxycycline treatment. We propose that these non-invasive MRI techniques offer insight into pathologic mechanisms underpinning Alzheimer's disease that may be important when evaluating emerging therapeutics targeting one of more of these processes. PMID:26923415

Centaur in-tank explosion flow fields within STS and Titan 4 payload spaces

NASA Technical Reports Server (NTRS)

Eck, M.; Mukunda, M.

1988-01-01

Explosions are examined which result from the mixing of liquid hydrogen and liquid oxygen (LH2-LO2) such that the reactants are confined by the missile (CBM) body. Explosion which were confined by the ground surface (CBGS) were also studied, with results reported elsewhere. Initial attempts to predict the reported PYRO experimental results were unsuccessful. A new reaction energy addition hypothesis was then developed and tested. The results obtained provide reasonable agreement with the experiments both in the near and far field. Calculations were performed to predict the environment which would occur at the Galileo Radioisotope Thermoelectric Generator (RTG) location given a Centaur G' upper stage and an STS launch vehicle. It was concluded that the principle threat to the RTG in this environment would be the impact of a slug of LH2. No analyses were conducted to assess the response of the Galileo RTG to such an environment. It was shown that the flow field resulting from the failure of the Centaur G' tankage was benign. It was concluded that while the cryogen particle velocity was very high, the flow field density was extremely low. As a result, the dynamic pressure was a trivial eight psia.

Underwater (UW) Unexploded Ordnance (UXO) Multi-Sensor Data Base (MSDB) Collection

DTIC Science & Technology

2009-07-01

11 FIGURE 6 RTG SENSOR. FOUR SENSOR TRIADS ARE SHOWN, EACH WITH A 3-AXIS FLUXGATE MAGNETOMETER ...used by RTG to measure the gradients. Each triad includes a 3-axis fluxgate magnetometer and a set of feedback coils. The outputs of three triad...each with a 3-axis fluxgate magnetometer (internal, not clearly visible) and a set of 3 feedback coils. The upper triad 3-axis magnetometer

Summary of miscellaneous hazard environments for hypothetical Space Shuttle and Titan IV launch abort accidents

NASA Technical Reports Server (NTRS)

Eck, M.; Mukunda, M.

1989-01-01

The various analyses described here were aimed at obtaining a more comprehensive understanding and definition of the environments in the vicinity of the Radioisotope Thermal Generator (RTG) during certain Space Transportation System (STS) and Titan IV launch abort accidents. Addressed here are a number of issues covering explosion environments and General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) responses to those environments.

GPHS-RTGs in support of the Cassini Mission

NASA Astrophysics Data System (ADS)

1994-10-01

The progress on the radioisotope generators and ancillary activities is described. This report is organized by program task as follows: spacecraft integration and liaison; engineering support; safety; qualified unicouple fabrication; ETG fabrication, assembly, and test; ground support equipment; RTG shipping and launch support; design, reviews, and mission applications; project management, quality assurance and reliability, contract changes, non-capital CAGO acquisition, and CAGO maintenance; contractor acquired government owned property (CAGO) acquisition.

GPHS-RTGs in support of the Cassini mission

NASA Astrophysics Data System (ADS)

1992-04-01

The technical progress achieved during the period 30 Mar. - 27 Sep. 1992 is described. Topics covered include: spacecraft integration and liaison; engineering support; safety; qualified unicouple production, ETG fabrication, assembly, and test; ground support equipment; radioisotope thermoelectric generators (RTG) shipping and launch support; designs, reviews, and mission applications; project management, quality assurance, reliability, contract changes, non-capital contractor acquired government owned (CAGO) acquisitions, and CAGO maintenance; and CAGO acquisitions.

SCO-1, a Novel Plasmid-Mediated Class A β-Lactamase with Carbenicillinase Characteristics from Escherichia coli▿

PubMed Central

Papagiannitsis, C. C.; Loli, A.; Tzouvelekis, L. S.; Tzelepi, E.; Arlet, G.; Miriagou, V.

2007-01-01

A novel class A β-lactamase (SCO-1) encoded by an 80-kb self-transferable plasmid from Escherichia coli is described. The interaction of SCO-1 with β-lactams was similar to that of the CARB-type enzymes. Also, SCO-1 exhibited a 51% amino acid sequence identity with the RTG subgroup of chromosomal carbenicillinases (RTG-1, CARB-5, and CARB-8). PMID:17353248

Apollo 12 Mission image - Alan Bean unloads ALSEP RTG fuel element

NASA Image and Video Library

1969-11-19

AS12-46-6790 (19 Nov. 1969) --- Astronaut Alan L. Bean, lunar module pilot, is photographed at quadrant II of the Lunar Module (LM) during the first Apollo 12 extravehicular activity (EVA) on the moon. This picture was taken by astronaut Charles Conrad Jr., commander. Here, Bean is using a fuel transfer tool to remove the fuel element from the fuel cask mounted on the LM's descent stage. The fuel element was then placed in the Radioisotope Thermoelectric Generator (RTG), the power source for the Apollo Lunar Surface Experiments Package (ALSEP) which was deployed on the moon by the two astronauts. The RTG is next to Bean's right leg. While astronauts Conrad and Bean descended in the LM "Intrepid" to explore the Ocean of Storms region of the moon, astronaut Richard F. Gordon Jr., command module pilot, remained with the Command and Service Modules (CSM) "Yankee Clipper" in lunar orbit.

SNAP 19 Viking Program. Bimonthly technical progress report, February 1980-March 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-01-01

Viking 1 Lander power system data has not been available during this reporting period, but summary reports indicate no anomalies in performance. Monitoring and evaluation of Viking 2 Lander power system data continued. Temperature data were similar to those 23 months ago, but combined RTG output power was down by 7 watts from the 75 watts recorded in February of 1978. On February 7, 1980, during a scheduled relay transmission the Lander 2 battery voltage dropped below 26.5 volts. With the orbiter attitude control gas supply nearly depleted and the space network stations required for Voyager encounter with Saturn latermore » this year, the final relay from Viking Lander 2 had been scheduled to take place on April 11. The attempt was made but no data were received. Power system performance data for Pioneer 10 and Pioneer Saturn (initially designated Pioneer 11) were monitored. The estimated RTG system net power was 115 watts for both, Pioneer 10 and Pioneer Saturn. The telemetry signal quality from Pioneer Saturn remains excellent. Pioneer 10, for the first time, shows a loss of signal strength.« less

Space nuclear safety from a user's viewpoint

NASA Technical Reports Server (NTRS)

Campbell, R. W.

1985-01-01

The National Aeronautics and Space Administration (NASA) launched the Jet Propulsion Laboratory's (JPL) two Voyager spacecraft to Jupiter in 1977, each using three radioisotope thermoelectric generators (RTGs) supplied by the Department of Energy (DOE) for onboard electric power. In 1986 NASA will launch JPL's Galileo spacecraft to Jupiter equipped with two DOE supplied RTGs of an improved design. NASA and JPL are also responsible for obtaining a single RTG of this type from DOE and supplying it to the European Space Agency as part of its participation in the International Solar Polar Mission. As a result of these missions, JPL has been deeply involved in space nuclear safety as a user. This paper will give a brief review of the user contributions by JPL - and NASA in general - to the nuclear safety processes and relate them to the overall nuclear safety program necessary for the launch of an RTG. The two major safety areas requiring user support are the ground operations involving RTGs at the launch site and the failure modes and probabilities associated with launch accidents.

Thermal Energy Conversion Branch

NASA Technical Reports Server (NTRS)

Bielozer, Matthew C.; Schreiber, Jeffrey, G.; Wilson, Scott D.

2004-01-01

The Thermal Energy Conversion Branch (5490) leads the way in designing, conducting, and implementing research for the newest thermal systems used in space applications at the NASA Glenn Research Center. Specifically some of the most advanced technologies developed in this branch can be broken down into four main areas: Dynamic Power Systems, Primary Solar Concentrators, Secondary Solar Concentrators, and Thermal Management. Work was performed in the Dynamic Power Systems area, specifically the Stirling Engine subdivision. Today, the main focus of the 5490 branch is free-piston Stirling cycle converters, Brayton cycle nuclear reactors, and heat rejection systems for long duration mission spacecraft. All space exploring devices need electricity to operate. In most space applications, heat energy from radioisotopes is converted to electrical power. The Radioisotope Thermoelectric Generator (RTG) already supplies electricity for missions such as the Cassini Spacecraft. The focus of today's Stirling research at GRC is aimed at creating an engine that can replace the RTG. The primary appeal of the Stirling engine is its high system efficiency. Because it is so efficient, the Stirling engine will significantly reduce the plutonium fuel mission requirements compared to the RTG. Stirling is also being considered for missions such as the lunar/Mars bases and rovers. This project has focused largely on Stirling Engines of all types, particularly the fluidyne liquid piston engine. The fluidyne was developed by Colin D. West. This engine uses the same concepts found in any type of Stirling engine, with the exception of missing mechanical components. All the working components are fluid. One goal was to develop and demonstrate a working Stirling Fluidyne Engine at the 2nd Annual International Energy Conversion Engineering Conference in Providence, Rhode Island.

Long term behavior of silicon germanium thermoelectric generators

NASA Technical Reports Server (NTRS)

Shields, V.

1981-01-01

Results of tests of the long term performance of SiGe radioisotope thermoelectric generators (RTG) are presented. Three modules were monitored for 17,000-32,300 hr at hot junction temperatures of 1,085, 1,055, and 1,000 C; coating the unicouples with a 12,000 A thick layer of Si3N4 protected the modules from Si sublimation. Output degraded less than 0.3-0.4%/1,000 hr over the testing period. Life tests on a multihundredwatt (MHW) SiGe generator with 312 couples at a hot shoe temperature of 1,040 C dealt with power of 150 W at 30 V, with 0.5%/1,000 hr performance degradation. Si deposition on the insulation was found to enhance electrical conductance until a saturation point was reached. Disassembly of a test module after 16,750 hr revealed a Mo build-up, SiN4 coating deterioration, and Ti diffustion from the hot shoe to cooler regions of the junction. The presence of an Al2O3 insulator was recognized as preventing coating loss. Performance records from the Voyager and Les-8 satellites' RTG's are compared and show similar, 0.25%/1,000 hr degradation rates; RTG storage is judged to be feasible and the tests lead to projections of a 600,000 hr lifetime for a SiGe RTG.

GPHS-RTGs in support of the Cassini mission

NASA Astrophysics Data System (ADS)

1994-04-01

This report is organized by the program task structure as follows: (1) spacecraft integration and liaison; (2) engineering support; (3) safety; (4) qualified unicouple fabrication; (5) ETG fabrication, assembly, and test; (6) ground support equipment (GSE); (7) RTG shipping and launch support; (8) designs, reviews, and mission applications; (9) project management, quality assurance and reliability, contract changes, noncapital contractor acquired government owned property (CAGO) acquisition, and CAGO maintenance; and (10) CAGO acquisition.

Test and evaluation of the Navy half-watt RTG. [Radioisotope Thermoelectric Generator

NASA Technical Reports Server (NTRS)

Rosell, F. E., Jr.; Lane, S. D.; Eggers, P. E.; Gawthrop, W. E.; Rouklove, P. G.; Truscello, V. C.

1976-01-01

The radioisotope thermoelectric generator (RTG) considered is to provide a continuous minimum power output of 0.5 watt at 6.0 to 8.5 volts for a minimum period of 15 years. The mechanical-electrical evaluation phase discussed involved the conduction of shock and vibration tests. The thermochemical-physical evaluation phase consisted of an analysis of the materials and the development of a thermal model. The thermoelectric evaluation phase included the accelerated testing of the thermoelectric modules.

Radioisotope Thermoelectric Generators Emplaced in the Deep Ocean, Recover or Dispose in Situ

DTIC Science & Technology

1986-03-01

00 0 M! Technical Report 1106 Cll ) March 1986 Radioisotope Thermoelectric 00 Generators Emplaced in the Deep Ocean Recover or Dispose In Situ? 00...PROGRAM ELEMENT NO PROJECT NO8 TASK NO WORK UN IT NO NAV’COMPT 141 N� A8 WR00026 I I TITLE i,cmvd. Secunty CIaxssIoe,o’,) Radioisotope Thermoelectric ...disposal alternatives. . RTG DESCRIPTIONS Each RTG consists of a strontium-90 titanate heat source, thermoelectric generator, thermal insulation

Retrograde Signaling as a Mechanism of Yeast Adaptation to Unfavorable Factors.

PubMed

Trendeleva, T A; Zvyagilskaya, R A

2018-02-01

Mitochondria perform many essential functions in eukaryotic cells. Being the main producers of ATP and the site of many catabolic and anabolic reactions, they participate in intracellular signaling, proliferation, aging, and formation of reactive oxygen species. Mitochondrial dysfunction is the cause of many diseases and even cell death. The functioning of mitochondria in vivo is impossible without interaction with other cellular compartments. Mitochondrial retrograde signaling is a signaling pathway connecting mitochondria and the nucleus. The major signal transducers in the yeast retrograde response are Rtg1p, Rtg2p, and Rtg3p proteins, as well as four additional negative regulatory factors - Mks1p, Lst8p, and two 14-3-3 proteins (Bmh1/2p). In this review, we analyze current information on the retrograde signaling in yeast that is regarded as a stress or homeostatic response mechanism to changes in various metabolic and biosynthetic activities that occur upon mitochondrial dysfunction. We also discuss relations between retrograde signaling and other signaling pathways in the cell.

Apollo 12 Mission image - Modular Equipment Stowage Assemble (MESA) and the Fuel Cask on the Lunar Module (LM)

NASA Image and Video Library

1969-11-19

AS12-48-7034 (19 Nov. 1969) --- A close-up view of a portion of quadrant II of the descent stage of the Apollo 12 Lunar Module (LM), photographed during the Apollo 12 extravehicular activity (EVA). At lower left is the LM's Y footpad. The empty Radioisotope Thermoelectric Generator (RTG) fuel cask is at upper right. The fuel capsule has already been removed and placed in the RTG. The RTG furnishes power for the Apollo Lunar Surface Experiments Package (ALSEP) which the Apollo 12 astronauts deployed on the moon. The LM's descent engine skirt is in the center background. The rod-like object protruding out from under the footpad is a lunar surface sensing probe. Astronaut Richard F. Gordon Jr., command module pilot, remained with the Command and Service Modules (CSM) in lunar orbit while astronauts Charles Conrad Jr., commander; and Alan L. Bean, lunar module pilot, descended in the LM to explore the moon.

Design, fabricate, and provide engineering support for radiosotope thermoelectric generators for NASA'S CRHF and CASSINI missions

NASA Astrophysics Data System (ADS)

The technical progress achieved during the period 11 January through 31 March 1991 on Contract DE-AC03-91SF18852.000 Radioisotope Thermoelectric Generators and ancillary activities is described. The system contract consists of the following tasks: (1) Spacecraft Integration and Liaison; (2) Engineering Support; (3) Safety; (4) Qualify Unicouple Fabrication; (5) ETG Fabrication, Assembly and Test; (6) GSE; (7) RTG Shipping and Launch Support; (8) Designs, Reviews, and Mission Applications; (9) Project Management, Quality Assurance and Reliability; and (10) CAGO Acquisition (Capital Funds). The progress achieved is broken down into these tasks.

In vivo axonal transport deficits in a mouse model of fronto-temporal dementia

PubMed Central

Majid, Tabassum; Ali, Yousuf O.; Venkitaramani, Deepa V.; Jang, Ming-Kuei; Lu, Hui-Chen; Pautler, Robia G.

2014-01-01

Background Axonal transport is vital for neurons and deficits in this process have been previously reported in a few mouse models of Alzheimer's disease prior to the appearance of plaques and tangles. However, it remains to be determined whether axonal transport is defective prior to the onset of neurodegeneration. The rTg4510 mouse, a fronto-temporal dementia and parkinsonism-17 (FTDP-17) tauopathy model, over-express tau-P301L mutation found in familial forms of FTDP-17, in the forebrain driven by the calcium–calmodulin kinase II promoter. This mouse model exhibits tau pathology, neurodegeneration in the forebrain, and associated behavioral deficits beginning at 4–5 months of age. Animal model rTg4510 transgenic mice were used in these studies. Mice were given 2 μL of MnCl2 in each nostril 1 h prior to Magnetic Resonance Imaging (MRI). Following MnCl2 nasal lavage, mice were imaged using Manganese enhanced Magnetic Resonance Imaging (MEMRI) Protocol with TE = 8.5 ms, TR = 504 ms, FOV = 3.0 cm, matrix size = 128 × 128 × 128, number of cycles = 15 with each cycle taking approximately 2 min, 9 s, and 24 ms using Paravision software (BrukerBioSpin, Billerica, MA). During imaging, body temperature was maintained at 37.0 °C using an animal heating system (SA Instruments, Stony Brook, NY). Data analysis Resulting images were analyzed using Paravision software. Regions of interest (ROI) within the olfactory neuronal layer (ONL) and the water phantom consisting of one pixel (ONL) and 9 pixels (water) were selected and copied across each of the 15 cycles. Signal intensities (SI) of ONL and water phantom ROIs were measured. SI values obtained for ONL were then normalized the water phantom SI values. The correlation between normalized signal intensity in the ONL and time were assessed using Prism (GraphPad Software, San Diego, CA). Results Using the MEMRI technique on 1.5, 3, 5, and 10-month old rTg4510 mice and littermate controls, we found significant axonal transport deficits present in the rTg4510 mice beginning at 3 months of age in an age-dependent manner. Using linear regression analysis, we measured rates of axonal transport at 1.5, 3, 5, and 10 months of age in rTg4510 and WT mice. Axonal transport rates were observed in rTg4510 mice at 48% of WT levels at 3 months, 40% of WT levels at 5 months, and 30% of WT levels at 10 months of age. In order to determine the point at which tau appears in the cortex, we probed for phosphorylated tau levels, and found that pSer262 is present at 3 months of age, not earlier at 1.5 months of age, but observed no pathological tau species until 6 months of age, months after the onset of the transport deficits. In addition, we saw localization of tau in the ONL at 6 months of age. Discussion In our study, we identified the presence of age-dependent axonal transport deficits beginning at 3 months of age in rTg4510 mice. We correlated these deficits at 3 months to the presence of hyperphosphorylated tau in the brain and the presence within the olfactory epithelium. We observed tau pathology not only in the soma of these neurons but also within the axons and processes of these neurons. Our characterization of axonal transport in this tauopathy model provides a functional time point that can be used for future therapeutic interventions. PMID:24936422

In vivo axonal transport deficits in a mouse model of fronto-temporal dementia.

PubMed

Majid, Tabassum; Ali, Yousuf O; Venkitaramani, Deepa V; Jang, Ming-Kuei; Lu, Hui-Chen; Pautler, Robia G

2014-01-01

Axonal transport is vital for neurons and deficits in this process have been previously reported in a few mouse models of Alzheimer's disease prior to the appearance of plaques and tangles. However, it remains to be determined whether axonal transport is defective prior to the onset of neurodegeneration. The rTg4510 mouse, a fronto-temporal dementia and parkinsonism-17 (FTDP-17) tauopathy model, over-express tau-P301L mutation found in familial forms of FTDP-17, in the forebrain driven by the calcium-calmodulin kinase II promoter. This mouse model exhibits tau pathology, neurodegeneration in the forebrain, and associated behavioral deficits beginning at 4-5 months of age. rTg4510 transgenic mice were used in these studies. Mice were given 2 μL of MnCl2 in each nostril 1 h prior to Magnetic Resonance Imaging (MRI). Following MnCl2 nasal lavage, mice were imaged using Manganese enhanced Magnetic Resonance Imaging (MEMRI) Protocol with TE = 8.5 ms, TR = 504 ms, FOV = 3.0 cm, matrix size = 128 × 128 × 128, number of cycles = 15 with each cycle taking approximately 2 min, 9 s, and 24 ms using Paravision software (BrukerBioSpin, Billerica, MA). During imaging, body temperature was maintained at 37.0 °C using an animal heating system (SA Instruments, Stony Brook, NY). Resulting images were analyzed using Paravision software. Regions of interest (ROI) within the olfactory neuronal layer (ONL) and the water phantom consisting of one pixel (ONL) and 9 pixels (water) were selected and copied across each of the 15 cycles. Signal intensities (SI) of ONL and water phantom ROIs were measured. SI values obtained for ONL were then normalized the water phantom SI values. The correlation between normalized signal intensity in the ONL and time were assessed using Prism (GraphPad Software, San Diego, CA). Using the MEMRI technique on 1.5, 3, 5, and 10-month old rTg4510 mice and littermate controls, we found significant axonal transport deficits present in the rTg4510 mice beginning at 3 months of age in an age-dependent manner. Using linear regression analysis, we measured rates of axonal transport at 1.5, 3, 5, and 10 months of age in rTg4510 and WT mice. Axonal transport rates were observed in rTg4510 mice at 48% of WT levels at 3 months, 40% of WT levels at 5 months, and 30% of WT levels at 10 months of age. In order to determine the point at which tau appears in the cortex, we probed for phosphorylated tau levels, and found that pSer262 is present at 3 months of age, not earlier at 1.5 months of age, but observed no pathological tau species until 6 months of age, months after the onset of the transport deficits. In addition, we saw localization of tau in the ONL at 6 months of age. In our study, we identified the presence of age-dependent axonal transport deficits beginning at 3 months of age in rTg4510 mice. We correlated these deficits at 3 months to the presence of hyperphosphorylated tau in the brain and the presence within the olfactory epithelium. We observed tau pathology not only in the soma of these neurons but also within the axons and processes of these neurons. Our characterization of axonal transport in this tauopathy model provides a functional time point that can be used for future therapeutic interventions.

RTG performance on Galileo and Ulysses and Cassini test results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, C. Edward; Klee, Paul M.

Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Similar comparisons are made for the RTG on the Ulysses spacecraft which completed its planned mission in 1995. Also presented are test results from small scale thermoelectric modules and full scale converters performed for the Cassini program. The Cassini mission to Saturn is scheduled for an October 1997 launch. Small scale module test results on thermoelectric couples from the qualification and flight production runs are shown. These tests have exceeded 19,000more » hours are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. Test results are presented for full scale units both ETGs (E-6, E-7) and RTGs (F-2, F-5) along with mission power predictions. F-5, fueled in 1985, served as a spare for the Galileo and Ulysses missions and plays the same role in the Cassini program. It has successfully completed all acceptance testing. The ten years storage between thermal vacuum tests is the longest ever experienced by an RTG. The data from this test are unique in providing the effects of long term low temperature storage on power output. All ETG and RTG test results to date indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of at least five percent are predicted.« less

Effects of structured testing versus routine testing of blood glucose in diabetes self-management: A randomized controlled trial.

PubMed

Nishimura, Akiko; Harashima, Shin-Ichi; Fujita, Yoshihito; Tanaka, Daisuke; Wang, Yu; Liu, Yanyan; Inagaki, Nobuya

2017-01-01

To compare the effects of structured and routine testing regimens used in self-monitoring of blood glucose (SMBG) on glycemic control and diabetes self-management in insulin-naïve type 2 diabetes patients. Sixty-two outpatients with insulin-naïve type 2 diabetes were randomly allocated into two less-frequent SMBG usage groups: a structured testing group (STG) and a routine testing group (RTG). Subjects in STG measured 7-points on SMBG for 3 consecutive days once every two months without daily testing; subjects in RTG measured SMBG 3 times each week before breakfast on Monday and Friday and before dinner on Wednesday. The primary endpoint was HbA1c reduction. The secondary endpoints were change in body weight, blood pressure, treatment change, and self-management performance change. HbA1c levels were significantly decreased by 0.32% (3.50mmol/mol) in STG, partly because physicians changed medications more actively. In contrast, body weight and systolic/diastolic blood pressure were significantly reduced by 0.94kg and 6.8/4.7mmHg, respectively, in RTG, possibly related to the increased diet and exercise score in RTG. Structured testing without daily testing is beneficial for glycemic control; routine testing 3 times a week is more helpful for daily self-management. In low SMBG frequency usage, these two regimens can be utilized according to individual diabetic conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

Design of a nuclear isotope heat source assembly for a spaceborne mini-Brayton power module.

NASA Technical Reports Server (NTRS)

Wein, D.; Gorland, S. H.

1973-01-01

Results of a study to develop a feasible design definition of a heat source assembly (HSA) for use in nominal 500-, 1200-, or 2000-W(e) mini-Brayton spacecraft power systems. The HSA is a modular design which is used either as a single unit to provide thermal energy to the 500-W(e) mini-Brayton power module or in parallel with one or two additional HSAs for the 1200- or 2000-W(e) power module systems. Principal components consist of a multihundred watt RTG isotope heat source, a heat source heat exchanger which transfers the thermal energy from the heat source to the mini-Brayton power conversion system, an auxiliary cooling system which provides requisite cooling during nonoperation of the power conversion module and an emergency cooling system which precludes accidental release of isotope fuel in the event of system failure.

RTG resource book for western states and provinces: Final proceedings

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The Western Interstate Energy Board held a workshop and liaison activities among western states, provinces, and utilities on the formation of Regional Transmission Groups (RTGs). Purpose of the activities was to examine the policy implications for western states and provinces in the formation of RTGs in the West, the implications for western ratepayers and utilities of the RTG formation and potential impacts of RTGs on the western electricity system. The workshop contributed to fulfilling the transmission access and competition objectives of Title VII of the Energy Policy Act of 1992.

A Simple Technique for Creating Regional Composites of Sea Surface Temperature from MODIS for Use in Operational Mesoscale NWP

NASA Technical Reports Server (NTRS)

Knievel, Jason C.; Rife, Daran L.; Grim, Joseph A.; Hahmann, Andrea N.; Hacker, Joshua P.; Ge, Ming; Fisher, Henry H.

2010-01-01

This paper describes a simple technique for creating regional, high-resolution, daytime and nighttime composites of sea surface temperature (SST) for use in operational numerical weather prediction (NWP). The composites are based on observations from NASA s Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Aqua and Terra. The data used typically are available nearly in real time, are applicable anywhere on the globe, and are capable of roughly representing the diurnal cycle in SST. The composites resolution is much higher than that of many other standard SST products used for operational NWP, including the low- and high-resolution Real-Time Global (RTG) analyses. The difference in resolution is key because several studies have shown that highly resolved SSTs are important for driving the air sea interactions that shape patterns of static stability, vertical and horizontal wind shear, and divergence in the planetary boundary layer. The MODIS-based composites are compared to in situ observations from buoys and other platforms operated by the National Data Buoy Center (NDBC) off the coasts of New England, the mid-Atlantic, and Florida. Mean differences, mean absolute differences, and root-mean-square differences between the composites and the NDBC observations are all within tenths of a degree of those calculated between RTG analyses and the NDBC observations. This is true whether or not one accounts for the mean offset between the skin temperatures of the MODIS dataset and the bulk temperatures of the NDBC observations and RTG analyses. Near the coast, the MODIS-based composites tend to agree more with NDBC observations than do the RTG analyses. The opposite is true away from the coast. All of these differences in point-wise comparisons among the SST datasets are small compared to the 61.08C accuracy of the NDBC SST sensors. Because skin-temperature variations from land to water so strongly affect the development and life cycle of the sea breeze, this phenomenon was chosen for demonstrating the use of the MODIS-based composite in an NWP model. A simulated sea breeze in the vicinity of New York City and Long Island shows a small, net, but far from universal improvement when MODIS-based composites are used in place of RTG analyses. The timing of the sea breeze s arrival is more accurate at some stations, and the near-surface temperature, wind, and humidity within the breeze are more realistic.

RTG performance on Galileo and Ulysses and Cassini test results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, C.E.; Klee, P.M.

Power output from telemetry for the two Galileo RTGs are shown from the 1989 launch to the recent Jupiter encounter. Comparisons of predicted, measured and required performance are shown. Similar comparisons are made for the RTG on the Ulysses spacecraft which completed its planned mission in 1995. Also presented are test results from small scale thermoelectric modules and full scale converters performed for the Cassini program. The Cassini mission to Saturn is scheduled for an October 1997 launch. Small scale module test results on thermoelectric couples from the qualification and flight production runs are shown. These tests have exceeded 19,000more » hours are continuing to provide increased confidence in the predicted long term performance of the Cassini RTGs. Test results are presented for full scale units both ETGs (E-6, E-7) and RTGs (F-2, F-5) along with mission power predictions. F-5, fueled in 1985, served as a spare for the Galileo and Ulysses missions and plays the same role in the Cassini program. It has successfully completed all acceptance testing. The ten years storage between thermal vacuum tests is the longest ever experienced by an RTG. The data from this test are unique in providing the effects of long term low temperature storage on power output. All ETG and RTG test results to date indicate that the power requirements of the Cassini spacecraft will be met. BOM and EOM power margins of at least five percent are predicted. {copyright} {ital 1997 American Institute of Physics.}« less

Sustainable land management practices as providers of several ecosystem services under rainfed Mediterranean agroecosystems

NASA Astrophysics Data System (ADS)

Almagro, María; de Vente, Joris; Boix-Fayós, Carolina; García-Franco, Noelia; Melgares de Aguilar, Javier; González, David; Solé-Benet, Albert; Martínez-Mena, María

2015-04-01

Little is known about the multiple impacts of sustainable land management practices on soil and water conservation, carbon sequestration, mitigation of global warming, and crop yield productivity in semiarid Mediterranean agroecosystems. We hypothesized that a shift from intensive tillage to more conservative tillage management practices (reduced tillage optionally combined with green manure) leads to an improvement in soil structure and quality and will reduce soil erosion and enhance carbon sequestration in semiarid Mediterranean rainfed agroecosystems. To test the hypothesis, we assessed the effects of different tillage treatments (conventional (CT), reduced (RT), reduced tillage combined with green manure (RTG), and no tillage (NT)) on soil structure and soil water content, runoff and erosion control, soil CO2 emissions, crop yield and carbon sequestration in two semiarid agroecosystems with organic rainfed almond in the Murcia Region southeast Spain). It was found that reduction and suppression of tillage under almonds led to an increase in soil water content in both agroecosystems. Crop yields ranged from 775 to 1766 kg ha-1 between tillage 18 treatments, but we did not find a clear relation between soil water content and crop yield. RT and RTG treatments showed lower soil erosion rates and higher crop yields of almonds than under CT treatment. Overall, higher soil organic carbon contents and aggregate stability were observed under RTG treatment than under RT or CT treatment. It is concluded that conversion from CT to RTG is suitable to increase carbon inputs without enhancing soil CO2 emissions in semiarid Mediterranean agroecosystems.

Dopaminergic Modulation of Cortical Plasticity in Alzheimer's Disease Patients

PubMed Central

Koch, Giacomo; Di Lorenzo, Francesco; Bonnì, Sonia; Giacobbe, Viola; Bozzali, Marco; Caltagirone, Carlo; Martorana, Alessandro

2014-01-01

In animal models of Alzheimer's disease (AD), mechanisms of cortical plasticity such as long-term potentiation (LTP) and long-term depression (LTD) are impaired. In AD patients, LTP-like cortical plasticity is abolished, whereas LTD seems to be preserved. Dopaminergic transmission has been hypothesized as a new player in ruling mechanisms of cortical plasticity in AD. We aimed at investigating whether administration of the dopamine agonist rotigotine (RTG) could modulate cortical plasticity in AD patients, as measured by theta burst stimulation (TBS) protocols of repetitive transcranial stimulation applied over the primary motor cortex. Thirty mild AD patients were tested in three different groups before and after 4 weeks of treatment with RTG, rivastigmine (RVT), or placebo (PLC). Each patient was evaluated for plasticity induction of LTP/LTD-like effects using respectively intermittent TBS (iTBS) or continuous TBS protocols. Short-latency afferent inhibition (SAI) protocol was performed to indirectly assess central cholinergic activity. A group of age-matched healthy controls was recruited for baseline comparisons. Results showed that at baseline, AD patients were characterized by impaired LTP-like cortical plasticity, as assessed by iTBS. These reduced levels of LTP-like cortical plasticity were increased and normalized after RTG administration. No effect was induced by RVT or PLC on LTP. LTD-like cortical plasticity was not modulated in any condition. Cholinergic activity was increased by both RTG and RVT. Our findings reveal that dopamine agonists may restore the altered mechanisms of LTP-like cortical plasticity in AD patients, thus providing novel implications for therapies based on dopaminergic stimulation. PMID:24859851

Parametric Study of Radiator Concepts for a Stirling Radioisotope Power System Applicable to Deep Space Mission

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.; Tew, Roy C.; Thieme, Lanny G.

2000-01-01

The Department of Energy (DOE) and the NASA Glenn Research Center are developing a Stirling converter for an advanced radioisotope power system to provide spacecraft onboard electric power for NASA deep space missions. This high-efficiency converter is being evaluated as an alternative to replace the much lower efficiency radioisotope thermoelectric generator (RTG). The current power requirement (six years after beginning of mission (BOM) for a mission to Jupiter) is 210 W(sub e) (watts electric) to be generated by two separate power systems, one on each side of the spacecraft. Both two-converter and four-converter system designs are being considered, depending on the amount of required redundancy.

The Prestige oil spill: a laboratory study about the toxicity of the water-soluble fraction of the fuel oil.

PubMed

Navas, José M; Babín, Mar; Casado, Susana; Fernández, Carlos; Tarazona, José V

2006-07-01

The Prestige oil spill caused severe effects on the coastal fauna and flora due to direct contact of organisms with the fuel oil. However, the water soluble fraction (WSF) of the fuel oil can also provoke deleterious effects in the long term and even in regions not directly affected by the spill. Our objective was to determine the toxicity of the WSF using a battery of laboratory toxicity tests. To obtain a WSF in the laboratory, a sample of the spilled fuel was mixed with adequate medium, sonicated, agitated and filtered. No cytotoxic effects were detected in RTG-2 cells exposed to the WSF. In an algae growth inhibition test (OECD test guideline 201) the WSF did not affect the growth of Chlorella vulgaris. Furthermore, acute and reproductive toxicity tests (OECD test guideline 202) carried out using Daphnia magna did not indicate any deleterious effect of the WSF. In a bioassay designed in our laboratory, D. magna were fed with algae previously exposed to the fuel, but no toxic effects were detected. However, the WSF was able to induce a dose-dependent increase of ethoxyresorufin-O-deethylase activity in RTG-2 cells, indicating the presence of chemicals that could cause sub-lethal effects to organisms. After chemical analyses it was established that the final total quantity of polyaromatic hydrocarbons dissolved in medium was approximately 70 ng/ml. These low concentrations explain the observed lack of toxicity.

Nuclear space power safety and facility guidelines study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehlman, W.F.

1995-09-11

This report addresses safety guidelines for space nuclear reactor power missions and was prepared by The Johns Hopkins University Applied Physics Laboratory (JHU/APL) under a Department of Energy grant, DE-FG01-94NE32180 dated 27 September 1994. This grant was based on a proposal submitted by the JHU/APL in response to an {open_quotes}Invitation for Proposals Designed to Support Federal Agencies and Commercial Interests in Meeting Special Power and Propulsion Needs for Future Space Missions{close_quotes}. The United States has not launched a nuclear reactor since SNAP 10A in April 1965 although many Radioisotope Thermoelectric Generators (RTGs) have been launched. An RTG powered system ismore » planned for launch as part of the Cassini mission to Saturn in 1997. Recently the Ballistic Missile Defense Office (BMDO) sponsored the Nuclear Electric Propulsion Space Test Program (NEPSTP) which was to demonstrate and evaluate the Russian-built TOPAZ II nuclear reactor as a power source in space. As of late 1993 the flight portion of this program was canceled but work to investigate the attributes of the reactor were continued but at a reduced level. While the future of space nuclear power systems is uncertain there are potential space missions which would require space nuclear power systems. The differences between space nuclear power systems and RTG devices are sufficient that safety and facility requirements warrant a review in the context of the unique features of a space nuclear reactor power system.« less

In vitro cellular responses in the RTG-2 cell line to complex mixtures of dioxins and dioxin-like PCDDs, PCDFs and PCBs.

PubMed

Babín, María del Mar; Sanz, Paloma; Concejero, Miguel Angel; Martínez, María Angeles; Tarazona, José Vicente

2010-08-01

High-resolution gas chromatography/mass spectrometry (HRGC/MS) is the standard method for analysing dioxin, furan and polybrominated retardants in hazardous waste. Determination of dioxin-like compounds using in vitro bioassays such as ethoxyresorufin-O-deethylase (EROD) is an important tool to evaluate their Ah receptor-mediated toxic effects, because it detects all arylhydrocarbon receptor ligands in a variety of sample matrices. In the present work, we compared RTG-2 cell line EROD bioassay with HRGC/MS for assessing waste samples (liquid and solid) contaminated with polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls (dioxin-like PCBs) and other xenobiotics. For liquid samples, HRGC/MS-toxic equivalent (HRGC/MS-TEQ) values ranged from 273.26 to 5.84 ng TEQ l(-1) and correlated well (correlation coefficient 0.99) with values obtained by EROD-TEQ, which ranged from 128 to 2.5 ng TEQ l(-1). For solid samples, HRGC/MS-TEQ values ranged from 3.44 to 0.49 ng TEQ g(-1) and correlated less well than liquid samples (correlation coefficient 0.64) with values obtained by EROD-TEQ ranging from 2.27 to 0.93 ng TEQ g(-1). The overestimation of RTG-2 EROD-TEQ (1.2 +/- 0.92 of values established by HRGC/MS) and the absence of false-negative results may limit analytical costs by eliminating the need for follow-up GC/MS analysis on the negative samples. We suggest that RTG-2 EROD bioassay is an inexpensive means for preliminary dioxin and furan positive screenings of waste samples. (c) 2010 John Wiley & Sons, Ltd.

Radioisotopic energy conversion system (RECS): A new radioisotopic power cell, based on nuclear, atomic, and radiation transport principles

NASA Astrophysics Data System (ADS)

Steinfelds, Eric Victor

The topic of this thesis is the development of the Radioisotope Energy Conversion System (RECS) in a project which is utilizing analytical computational assisted design and some experimental Research in the investigation of fluorescers and effective transducers with the appropriate energy range choice for the conversion of energy. It is desirable to increase the efficiency in electrical power from the raw kinetic power available from the radioactive material within radioisotope power generators. A major step in this direction is the development and use of Radioisotope Energy Conversion Systems to supplement and ideally replace Radioactive Thermal Generators (RTG). It is possible to achieve electrical conversion efficiencies exceeding 25% for RECS power devices compared to only 9 percent efficiency for RTG's. The theoretical basis with existent materials for the potential achievability of efficiencies above 25% is documented within this thesis. The fundamental RECS consists of a radioisotope radiative source (C1), a mediating fluorescent gas (C2) which readily absorbs energy from the beta particles (or alpha's) and subsequently emits blue or UV photons, photovoltaic cells (C3) to convert the blue and UV photons into electrical energy [2], and electrical circuitry (C4). Solid State inspired component (C3), due to its theoretical (and attainable) high efficiency, is a large step ahead of the RTG design concept. The radioisotope flux source produces the beta(-) particles or alpha particles. Geometrically, presently, we prefer to have the ambient fluorescent gas surround the radioisotope flux source. Our fluorescer shall be a gas such as Krypton. Our specifically wide band-gap photovoltaic cells shall have gap energies which are slightly less than that of UV photons produced by the fluorescing gas. Diamond and Aluminum Nitride sample materials are good potential choices for photovoltaic cells, as is explained here in. Out of the material examples discussed, the highest electric power to mass ratio is found to be readily attainable with strontium-90 as the radiative source. Krypton-85 is indisputably the most efficient in RECS devices. In the conclusion in chapter VI, suggestions are given on acceptable ways of containing krypton-85 and providing sufficient shielding on deep space probes destined to use krypton-85 powered 'batteries'.

GPS Software Packages Deliver Positioning Solutions

NASA Technical Reports Server (NTRS)

2010-01-01

"To determine a spacecraft s position, the Jet Propulsion Laboratory (JPL) developed an innovative software program called the GPS (global positioning system)-Inferred Positioning System and Orbit Analysis Simulation Software, abbreviated as GIPSY-OASIS, and also developed Real-Time GIPSY (RTG) for certain time-critical applications. First featured in Spinoff 1999, JPL has released hundreds of licenses for GIPSY and RTG, including to Longmont, Colorado-based DigitalGlobe. Using the technology, DigitalGlobe produces satellite imagery with highly precise latitude and longitude coordinates and then supplies it for uses within defense and intelligence, civil agencies, mapping and analysis, environmental monitoring, oil and gas exploration, infrastructure management, Internet portals, and navigation technology."

In vitro screening of organotin compounds and sediment extracts for cytotoxicity to fish cells.

PubMed

Giltrap, Michelle; Macken, Ailbhe; McHugh, Brendan; McGovern, Evin; Foley, Barry; Davoren, Maria

2011-01-01

The present study reports an in vitro screening method for contaminants in sediment samples utilizing an RTG-2 cell line. This technique integrates cytotoxicity testing with analytical chemistry with the aim of achieving a toxicity evaluation of the sediment sample. The toxic effect of individual organotin (OT) compounds and their presence in the sediment sample is the focus of the present study; however, other contaminants are also discussed. The following OT compounds: tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenyltin (DPT), and a sediment solvent extract are exposed to the RTG-2 fish cell line. Both the alamar blue (AB) and neutral red (NR) assays are used to assess cytotoxicity after 24-h and 96-h exposure. Methodology for preparation of a sediment solvent extract suitable for biological testing and analytical determination is also described. With the RTG-2 cells, the AB and NR assays had comparable sensitivity for each individual OT compound exposure after 24 h, with TPT being the most toxic compound tested. The individual OT compound concentrations required to induce a 50% toxic effect on the cells (369 ng ml⁻¹ TBT, 1,905 ng ml⁻¹ DBT) did not equate to the concentrations of these contaminants present in the sediment extract that induced a 50% effect on the cells (294 ng ml⁻¹ TBT, 109 ng ml⁻¹ DBT). The solvent extract therefore exhibited a greater toxicity, and this suggests that the toxic effects observed were not due to OT compounds alone. The presence of other contaminants in the solvent extract is confirmed with chemical analysis, warranting further toxicity testing of contaminant mixtures and exposure to the cell line to further elucidate a complete toxicity evaluation. © 2010 SETAC.

Hybrid thermocouple development program

NASA Technical Reports Server (NTRS)

Garvey, L. P.; Krebs, T. R.; Lee, E.

1971-01-01

The design and development of a hybrid thermocouple, having a segmented SiGe-PbTe n-leg encapsulated within a hollow cylindrical p-SiGe leg, is described. Hybrid couple efficiency is calculated to be 10% to 15% better than that of a all-SiGe couple. A preliminary design of a planar RTG, employing hybrid couples and a water heat pipe radiator, is described as an example of a possible system application. Hybrid couples, fabricated initially, were characterized by higher than predicted resistance and, in some cases, bond separations. Couples made later in the program, using improved fabrication techniques, exhibited normal resistances, both as-fabricated and after 700 hours of testing. Two flat-plate sections of the reference design thermoelectric converter were fabricated and delivered to NASA Lewis for testing and evaluation.

Pump for delivering heated fluids

NASA Technical Reports Server (NTRS)

Sabelman, E. E. (Inventor)

1973-01-01

A thermomechanical pump particularly suited for use in pumping a warming fluid obtained from an RTG (Radioisotope Thermal Generator) through science and flight instrumentation aboard operative spacecraft is described. The invention is characterized by a pair of operatively related cylinders, each including a reciprocating piston head dividing the cylinder into a pressure chamber confining therein a vaporizable fluid, and a pumping chamber for propelling the warming fluid, and a fluid delivery circuit for alternately delivering the warming fluid from the RTG through the pressure chamber of one cylinder to the pumping chamber of the other cylinder, whereby the vaporizable fluid within the pair of pressure chambers alternately is vaporized and condensed for driving the associated pistons in pumping and intake strokes.

Differential growth of U and M type infectious haematopoietic necrosis virus in a rainbow trout–derived cell line, RTG-2

USGS Publications Warehouse

Kurath, Gael; Purcell, Maureen K.; Wargo, Andrew; Park, Jeong Woo; Moon, Chang Hoon

2010-01-01

Infectious haematopoietic necrosis virus (IHNV) is one of the most important viral pathogens of salmonids. In rainbow trout, IHNV isolates in the M genogroup are highly pathogenic, while U genogroup isolates are significantly less pathogenic. We show here that, at a multiplicity of infection (MOI) of 1, a representative U type strain yielded 42-fold less infectious virus than an M type strain in the rainbow trout–derived RTG-2 cell line at 24 h post-infection (p.i.). However, at an MOI of 10, there was only fivefold difference in the yield of infectious virus between the U and M strains. Quantification of extracellular viral genomic RNA suggested that the number of virus particles released from cells infected with the U strain at a MOI of 1 was 47-fold lower than from M-infected cells, but U and M virions were equally infectious by particle to infectivity ratios. At an MOI of 1, U strain intracellular viral genome accumulation and transcription were 37- and 12-fold lower, respectively, than those of the M strain at 24 h p.i. Viral nucleocapsid (N) protein accumulation in U strain infections was fivefold lower than in M strain infections. These results suggest that the block in U type strain growth in RTG-2 cells was because of the effects of reduced genome replication and transcription. The reduced growth of the U strain does not seem to be caused by defective genes, because the U and M strains grew equally well in the permissive epithelioma papulosum cyprini cell line at an MOI of 1. This suggests that host-specific factors in RTG-2 cells control the growth of the IHNV U and M strains differently, leading to growth restriction of the U type virus during the RNA synthesis step.

Electrical and Network Neuronal Properties Are Preferentially Disrupted in Dorsal, But Not Ventral, Medial Entorhinal Cortex in a Mouse Model of Tauopathy

PubMed Central

Booth, Clair A.; Ridler, Thomas; Murray, Tracey K.; Ward, Mark A.; de Groot, Emily; Goodfellow, Marc; Phillips, Keith G.; Randall, Andrew D.

2016-01-01

The entorhinal cortex (EC) is one of the first areas to be disrupted in neurodegenerative diseases such as Alzheimer's disease and frontotemporal dementia. The responsiveness of individual neurons to electrical and environmental stimuli varies along the dorsal–ventral axis of the medial EC (mEC) in a manner that suggests this topographical organization plays a key role in neural encoding of geometric space. We examined the cellular properties of layer II mEC stellate neurons (mEC-SCs) in rTg4510 mice, a rodent model of neurodegeneration. Dorsoventral gradients in certain intrinsic membrane properties, such as membrane capacitance and afterhyperpolarizations, were flattened in rTg4510 mEC-SCs, while other cellular gradients [e.g., input resistance (Ri), action potential properties] remained intact. Specifically, the intrinsic properties of rTg4510 mEC-SCs in dorsal aspects of the mEC were preferentially affected, such that action potential firing patterns in dorsal mEC-SCs were altered, while those in ventral mEC-SCs were unaffected. We also found that neuronal oscillations in the gamma frequency band (30–80 Hz) were preferentially disrupted in the dorsal mEC of rTg4510 slices, while those in ventral regions were comparatively preserved. These alterations corresponded to a flattened dorsoventral gradient in theta-gamma cross-frequency coupling of local field potentials recorded from the mEC of freely moving rTg4510 mice. These differences were not paralleled by changes to the dorsoventral gradient in parvalbumin staining or neurodegeneration. We propose that the selective disruption to dorsal mECs, and the resultant flattening of certain dorsoventral gradients, may contribute to disturbances in spatial information processing observed in this model of dementia. SIGNIFICANCE STATEMENT The medial entorhinal cortex (mEC) plays a key role in spatial memory and is one of the first areas to express the pathological features of dementia. Neurons of the mEC are anatomically arranged to express functional dorsoventral gradients in a variety of neuronal properties, including grid cell firing field spacing, which is thought to encode geometric scale. We have investigated the effects of tau pathology on functional dorsoventral gradients in the mEC. Using electrophysiological approaches, we have shown that, in a transgenic mouse model of dementia, the functional properties of the dorsal mEC are preferentially disrupted, resulting in a flattening of some dorsoventral gradients. Our data suggest that neural signals arising in the mEC will have a reduced spatial content in dementia. PMID:26758825

Radiation Measurements in Cruise and on Mars by the MSL Radiation Assessment Detector

NASA Astrophysics Data System (ADS)

Zeitlin, C. J.; Hassler, D.; Wimmer-Schweingruber, R. F.; Appel, J. K.; Boehm, E.; Boettcher, S.; Brinza, D.; Burmeister, S.; Cucinotta, F.; Ehresmann, B.; Guo, J.; Kohler, J.; Lohf, H.; Martin, C.; Posner, A.; Rafkin, S. C.; Reitz, G.; Team, M.

2013-12-01

The Radiation Assessment Detector (RAD) is one of ten science instruments on the Curiosity rover. The RAD team's science objectives include the measurement of radiation dose (a purely physical quantity) and dose equivalent (a derived quantity that can be related to cancer risk) on the surface of Mars. In addition, RAD acquired data for most of the cruise to Mars, from Dec. 2011 through July 2012, providing a measurement of the radiation environment under conditions similar to those expected on a human trip to Mars or other deep space destinations. The dose and dose equivalent measurements made during cruise have been published, but are presented in more detail here. Rates measured in cruise are compared to similar measurements made during Curiosity's first 269 sols on the surface of Mars. In the simplest picture, one expects rates to be a factor of two lower on the surface of a large airless body compared to free space, owing to the two-pi shielding geometry. The situation on Mars is complicated by the non-negligible shielding effects of the atmosphere, particularly in Gale Crater where diurnal variations in atmospheric column depth are significant. The diurnal variations - caused by the well-known thermal tides on Mars - result in reduced shielding of the surface in the afternoon as compared to the night and early morning hours. A major challenge in analyzing the surface data is the treatment of the background radiation dose coming from Curiosity's Radioisotope Thermoelectric Generator (RTG). Prior to launch, RAD acquired data in the full cruise configuration so that this background could be measured with only sea-level cosmic ray muons present - that is, almost all of what was measured was due to the RTG. Those effects could therefore be subtracted from the cruise measurements in a straightforward way. However, the situation on the surface is somewhat different than in cruise, in that the mass that was present above RAD - and caused scattering of particles into the detector - is no longer there. The RTG-induced dose rate in the surface configuration must therefore be less than it was in the cruise configuration, but there is no way to get a direct measurement of the background. Quantifying the change in RTG background is difficult but essential, as the subtraction affects every aspect of the dosimetry. Two approaches have been developed and yield roughly similar results. The differences allow us to estimate the uncertainties arising from the RTG subtraction, and propagate those into the dosimetry results.

KSC-97PC1069

NASA Image and Video Library

1997-07-18

Jet Propulsion Laboratory (JPL) workers David Rice, at left, and Johnny Melendez rotate a radioisotope thermoelectric generator (RTG) to the horizontal position on a lift fixture in the Payload Hazardous Servicing Facility. The RTG is one of three generators which will provide electrical power for the Cassini spacecraft mission to the Saturnian system. The RTGs will be installed on the powered-up spacecraft for mechanical and electrical verification testing. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate far from the Sun where solar power systems are not feasible. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL

KSC-97PC1088

NASA Image and Video Library

1997-07-18

This radioisotope thermoelectric generator (RTG), at center, is ready for electrical verification testing now that it has been installed on the Cassini spacecraft in the Payload Hazardous Servicing Facility. A handling fixture, at far left, remains attached. This is the third and final RTG to be installed on Cassini for the prelaunch tests. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle

The Use of 2 Conditioning Programs and the Fitness Characteristics of Police Academy Cadets.

PubMed

Cocke, Charles; Dawes, Jay; Orr, Robin Marc

2016-11-01

 Police academy training must physically prepare cadets for the rigors of their occupational tasks to prevent injury and allow them to adequately perform their duties.  To compare the effects of 2 physical training programs on multiple fitness measures in police cadets.  Cohort study.  Police training academy.  We collected data from 70 male (age = 27.4 ± 5.9 years, body weight = 85.4 ± 11.8 kg) and 20 female (age = 30.5 ± 5.8 years, body weight = 62.8 ± 11.0 kg) police cadets and analyzed data from 61 male cadets (age = 27.5 ± 5.5 years, body weight = 87.7 ± 13.2 kg).  Participants completed one of two 6-month training programs. The randomized training group (RTG; n = 50), comprising 4 separate and sequential groups (n = 13, n = 11, n = 13, n = 13), completed a randomized training program that incorporated various strength and endurance exercises chosen on the day of training. The periodized group (PG; n = 11) completed a periodized training program that alternated specific phases of training.  Anthropometric fitness measures were body weight, fat mass, and lean body mass. Muscular and metabolic fitness measures were 1-repetition maximum bench press, push-up and sit-up repetitions performed in 1 minute, vertical jump, 300-m sprint, and 2.4-km run.  The RTG demonstrated improvements in all outcome measures between pretraining and posttraining; however, the improvements varied among the 4 individual RTGs. Conversely, the PG displayed improvements in only 3 outcome measures (push-ups, sit-ups, and 300-m sprint) but approached the level of significance set for this study (P < .01) in body weight, fat mass, and 1-repetition maximum bench press.  Regardless of format, physical training programs can improve the fitness of tactical athletes. In general, physical fitness measures appeared to improve more in the RTG than in the PG. However, this observation varied among groups, and injury rates were not compared.

Methylene blue does not reverse existing neurofibrillary tangle pathology in the rTg4510 mouse model of tauopathy.

PubMed

Spires-Jones, Tara L; Friedman, Taylor; Pitstick, Rose; Polydoro, Manuela; Roe, Allyson; Carlson, George A; Hyman, Bradley T

2014-03-06

Alzheimer's disease is characterized pathologically by aggregation of amyloid beta into senile plaques and aggregation of pathologically modified tau into neurofibrillary tangles. While changes in amyloid processing are strongly implicated in disease initiation, the recent failure of amyloid-based therapies has highlighted the importance of tau as a therapeutic target. "Tangle busting" compounds including methylene blue and analogous molecules are currently being evaluated as therapeutics in Alzheimer's disease. Previous studies indicated that methylene blue can reverse tau aggregation in vitro after 10 min, and subsequent studies suggested that high levels of drug reduce tau protein levels (assessed biochemically) in vivo. Here, we tested whether methylene blue could remove established neurofibrillary tangles in the rTg4510 model of tauopathy, which develops robust tangle pathology. We find that 6 weeks of methylene blue dosing in the water from 16 months to 17.5 months of age decreases soluble tau but does not remove sarkosyl insoluble tau, or histologically defined PHF1 or Gallyas positive tangle pathology. These data indicate that methylene blue treatment will likely not rapidly reverse existing tangle pathology. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Methylene blue does not reverse existing neurofibrillary tangle pathology in the rTg4510 mouse model of tauopathy

PubMed Central

Spires-Jones, Tara L; Friedman, Taylor; Pitstick, Rose; Polydoro, Manuela; Roe, Allyson; Carlson, George A; Hyman, Bradley T

2014-01-01

Alzheimer's disease is characterized pathologically by aggregation of amyloid beta into senile plaques and aggregation of pathologically modified tau into neurofibrillary tangles. While changes in amyloid processing are strongly implicated in disease initiation, the recent failure of amyloid-based therapies has highlighted the importance of tau as a therapeutic target. “Tangle busting” compounds including methylene blue and analogous molecules are currently being evaluated as therapeutics in Alzheimer's disease. Previous studies indicated that methylene blue can reverse tau aggregation in vitro after 10 minutes, and subsequent studies suggested that high levels of drug reduce tau protein levels (assessed biochemically) in vivo. Here, we tested whether methylene blue could remove established neurofibrillary tangles in the rTg4510 model of tauopathy, which develops robust tangle pathology. We find that 6 weeks of methylene blue dosing in the water from 16 months to 17.5 months of age decreases soluble tau but does not remove sarkosyl insoluble tau, or histologically defined PHF1 or Gallyas positive tangle pathology. These data indicate that methylene blue treatment will likely not rapidly reverse existing tangle pathology. PMID:24462887

Radioisotopic Thermoelectric Generator (RTG) Surveillance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulford, Roberta Nancy

2016-09-29

This lecture discusses stockpile stewardship efforts and the role surveillance plays in the process. Performance of the RTGs is described, and the question of the absence of anticipated He is addressed.

Astronaut John Young stands at ALSEP deployment site during first EVA

NASA Technical Reports Server (NTRS)

1972-01-01

Astronaut John W. Young, commander of the Apollo 16 lunar landing mission, stands at the Apollo Lunar Surface Experiments Package (ALSEP) deployment site during the first Apollo 16 extravehicular activity (EVA-1) at the Descartes landing site. The components of the ALSEP are in the background. The lunar surface drill is just behind and to the right of Young. The drill's rack and bore stems are to the left. The three sensor Lunar Surface Magnetometer is beyond the rack. The dark object in the right background is the Radioisotope Thermoelectric Generator (RTG). Between the RTG and the drill is the Heat Flow Experiment. A part of the Central Station is at the right center edge of the picture. This photograph was taken by Astronaut Charles M. Duke Jr., lunar module pilot.

Regulatory regions in the promoters of the Saccharomyces cerevisiae PYC1 and PYC2 genes encoding isoenzymes of pyruvate carboxylase.

PubMed

Menéndez, J; Gancedo, C

1998-07-15

We have identified regions in the promoters of the PYC1 and PYC2 genes from Saccharomyces cerevisiae involved in their regulation in different culture conditions. In the case of PYC1, a UAS in the region between -330/-297 and three repressing sequences with the common central core CCGCC at positions -457, -432 and -399 were identified. Specific binding of nuclear proteins to the -330/-214 DNA fragment was abolished in rtg mutants suggesting a role for the RTG genes in the control of PYC1 expression. In the case of the PYC2 promoter, elimination of a fragment from -417 to -291 brings about a two-fold decrease in the expression in repressed conditions and a similar increase in derepression.

Cassini's RTGs undergo mechanical and electrical verification tests in the PHSF

NASA Technical Reports Server (NTRS)

1997-01-01

This radioisotope thermoelectric generator (RTG), at center, is ready for electrical verification testing now that it has been installed on the Cassini spacecraft in the Payload Hazardous Servicing Facility. A handling fixture, at far left, remains attached. This is the third and final RTG to be installed on Cassini for the prelaunch tests. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle.

RANK/RANKL/OPG Signalization Implication in Periodontitis: New Evidence from a RANK Transgenic Mouse Model

PubMed Central

Sojod, Bouchra; Chateau, Danielle; Mueller, Christopher G.; Babajko, Sylvie; Berdal, Ariane; Lézot, Frédéric; Castaneda, Beatriz

2017-01-01

Periodontitis is based on a complex inflammatory over-response combined with possible genetic predisposition factors. The RANKL/RANK/OPG signaling pathway is implicated in bone resorption through its key function in osteoclast differentiation and activation, as well as in the inflammatory response. This central element of osteo-immunology has been suggested to be perturbed in several diseases, including periodontitis, as it is a predisposing factor for this disease. The aim of the present study was to validate this hypothesis using a transgenic mouse line, which over-expresses RANK (RTg) and develops a periodontitis-like phenotype at 5 months of age. RTg mice exhibited severe alveolar bone loss, an increased number of TRAP positive cells, and disorganization of periodontal ligaments. This phenotype was more pronounced in females. We also observed dental root resorption lacunas. Hyperplasia of the gingival epithelium, including Malassez epithelial rests, was visible as early as 25 days, preceding any other symptoms. These results demonstrate that perturbations of the RANKL/RANK/OPG system constitute a core element of periodontitis, and more globally, osteo-immune diseases. PMID:28596739

Disrupted hippocampal sharp‐wave ripple‐associated spike dynamics in a transgenic mouse model of dementia

PubMed Central

Witton, Jonathan; Staniaszek, Lydia E.; Bartsch, Ullrich; Randall, Andrew D.; Jones, Matthew W.

2015-01-01

Key points High frequency (100–250 Hz) neuronal oscillations in the hippocampus, known as sharp‐wave ripples (SWRs), synchronise the firing behaviour of groups of neurons and play a key role in memory consolidation.Learning and memory are severely compromised in dementias such as Alzheimer's disease; however, the effects of dementia‐related pathology on SWRs are unknown.The frequency and temporal structure of SWRs was disrupted in a transgenic mouse model of tauopathy (one of the major hallmarks of several dementias).Excitatory pyramidal neurons were more likely to fire action potentials in a phase‐locked manner during SWRs in the mouse model of tauopathy; conversely, inhibitory interneurons were less likely to fire phase‐locked spikes during SWRs.These findings indicate there is reduced inhibitory control of hippocampal network events and point to a novel mechanism which may underlie the cognitive impairments in this model of dementia. Abstract Neurons within the CA1 region of the hippocampus are co‐activated during high frequency (100–250 Hz) sharp‐wave ripple (SWR) activity in a manner that probably drives synaptic plasticity and promotes memory consolidation. In this study we have used a transgenic mouse model of dementia (rTg4510 mice), which overexpresses a mutant form of tau protein, to examine the effects of tauopathy on hippocampal SWRs and associated neuronal firing. Tetrodes were used to record simultaneous extracellular action potentials and local field potentials from the dorsal CA1 pyramidal cell layer of 7‐ to 8‐month‐old wild‐type and rTg4510 mice at rest in their home cage. At this age point these mice exhibit neurofibrillary tangles, neurodegeneration and cognitive deficits. Epochs of sleep or quiet restfulness were characterised by minimal locomotor activity and a low theta/delta ratio in the local field potential power spectrum. SWRs detected off‐line were significantly lower in amplitude and had an altered temporal structure in rTg4510 mice. Nevertheless, the average frequency profile and duration of the SWRs were relatively unaltered. Putative interneurons displayed significantly less temporal and phase locking to SWRs in rTg4510 mice, whilst putative pyramidal neurons showed increased temporal and phase locking to SWRs. These findings indicate there is reduced inhibitory control of hippocampal network events and point to a novel mechanism which may contribute to impairments in memory consolidation in this model of dementia. PMID:25480798

Disrupted hippocampal sharp-wave ripple-associated spike dynamics in a transgenic mouse model of dementia.

PubMed

Witton, Jonathan; Staniaszek, Lydia E; Bartsch, Ullrich; Randall, Andrew D; Jones, Matthew W; Brown, Jonathan T

2016-08-15

High frequency (100-250 Hz) neuronal oscillations in the hippocampus, known as sharp-wave ripples (SWRs), synchronise the firing behaviour of groups of neurons and play a key role in memory consolidation. Learning and memory are severely compromised in dementias such as Alzheimer's disease; however, the effects of dementia-related pathology on SWRs are unknown. The frequency and temporal structure of SWRs was disrupted in a transgenic mouse model of tauopathy (one of the major hallmarks of several dementias). Excitatory pyramidal neurons were more likely to fire action potentials in a phase-locked manner during SWRs in the mouse model of tauopathy; conversely, inhibitory interneurons were less likely to fire phase-locked spikes during SWRs. These findings indicate there is reduced inhibitory control of hippocampal network events and point to a novel mechanism which may underlie the cognitive impairments in this model of dementia. Neurons within the CA1 region of the hippocampus are co-activated during high frequency (100-250 Hz) sharp-wave ripple (SWR) activity in a manner that probably drives synaptic plasticity and promotes memory consolidation. In this study we have used a transgenic mouse model of dementia (rTg4510 mice), which overexpresses a mutant form of tau protein, to examine the effects of tauopathy on hippocampal SWRs and associated neuronal firing. Tetrodes were used to record simultaneous extracellular action potentials and local field potentials from the dorsal CA1 pyramidal cell layer of 7- to 8-month-old wild-type and rTg4510 mice at rest in their home cage. At this age point these mice exhibit neurofibrillary tangles, neurodegeneration and cognitive deficits. Epochs of sleep or quiet restfulness were characterised by minimal locomotor activity and a low theta/delta ratio in the local field potential power spectrum. SWRs detected off-line were significantly lower in amplitude and had an altered temporal structure in rTg4510 mice. Nevertheless, the average frequency profile and duration of the SWRs were relatively unaltered. Putative interneurons displayed significantly less temporal and phase locking to SWRs in rTg4510 mice, whilst putative pyramidal neurons showed increased temporal and phase locking to SWRs. These findings indicate there is reduced inhibitory control of hippocampal network events and point to a novel mechanism which may contribute to impairments in memory consolidation in this model of dementia. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

KSC-97PC1091

NASA Image and Video Library

1997-07-19

Lockheed Martin Missile and Space Co. employees Joe Collingwood, at right, and Ken Dickinson retract pins in the storage base to release a radioisotope thermoelectric generator (RTG) in preparation for hoisting operations. This RTG and two others will be installed on the Cassini spacecraft for mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed by NASA’s Jet Propulsion Laboratory

KSC-97PC1093

NASA Image and Video Library

1997-07-19

Supported on a lift fixture, this radioisotope thermoelectric generator (RTG), at center, is hoisted from its storage base using the airlock crane in the Payload Hazardous Servicing Facility (PHSF). Jet Propulsion Laboratory (JPL) workers are preparing to install the RTG onto the Cassini spacecraft, in background at left, for mechanical and electrical verification testing. The three RTGs on Cassini will provide electrical power to the spacecraft on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed by JPL

Astronaut John Young stands at ALSEP deployment site during first EVA

NASA Image and Video Library

1972-04-21

AS16-114-18388 (21 April 1972) --- Astronaut John W. Young, commander of the Apollo 16 lunar landing mission, stands at the Apollo Lunar Surface Experiments Package (ALSEP) deployment site during the first Apollo 16 extravehicular activity (EVA) at the Descartes landing site. The components of the ALSEP are in the background. The lunar surface drill is just behind and to the right of astronaut Young. The drill's rack and bore stems are to the left. The three-sensor Lunar Surface Magnetometer is beyond the rack. The dark object in the right background is the Radioisotope Thermoelectric Generator (RTG). Between the RTG and the drill is the Heat Flow Experiment. A part of the Central Station is at the right center edge of the picture. This photograph was taken by astronaut Charles M. Duke Jr., lunar module pilot.

Mitochondrial Energy and Redox Signaling in Plants

PubMed Central

Schwarzländer, Markus

2013-01-01

Abstract Significance: For a plant to grow and develop, energy and appropriate building blocks are a fundamental requirement. Mitochondrial respiration is a vital source for both. The delicate redox processes that make up respiration are affected by the plant's changing environment. Therefore, mitochondrial regulation is critically important to maintain cellular homeostasis. This involves sensing signals from changes in mitochondrial physiology, transducing this information, and mounting tailored responses, by either adjusting mitochondrial and cellular functions directly or reprogramming gene expression. Recent Advances: Retrograde (RTG) signaling, by which mitochondrial signals control nuclear gene expression, has been a field of very active research in recent years. Nevertheless, no mitochondrial RTG-signaling pathway is yet understood in plants. This review summarizes recent advances toward elucidating redox processes and other bioenergetic factors as a part of RTG signaling of plant mitochondria. Critical Issues: Novel insights into mitochondrial physiology and redox-regulation provide a framework of upstream signaling. On the other end, downstream responses to modified mitochondrial function have become available, including transcriptomic data and mitochondrial phenotypes, revealing processes in the plant that are under mitochondrial control. Future Directions: Drawing parallels to chloroplast signaling and mitochondrial signaling in animal systems allows to bridge gaps in the current understanding and to deduce promising directions for future research. It is proposed that targeted usage of new technical approaches, such as quantitative in vivo imaging, will provide novel leverage to the dissection of plant mitochondrial signaling. Antioxid. Redox Signal. 18, 2122–2144. PMID:23234467

DEVELOPMENT OF AN ENVIRONMENTAL ESTROGEN SCREEN USING TRANSIENTLY TRANSFECTED RAINBOW TROUT CELL LINES

EPA Science Inventory

Rainbow troutp hepatoma (RTH-149) and gonad cells (RTG-2) were used to develop a screening protocol for estrogen disrupting chemicals. Transfection of an estrogen-responsive luciferase reporter plasmid into...

Lethal and sublethal effects of marine sediment extracts on fish cells and chromosomes

NASA Astrophysics Data System (ADS)

Landolt, Marsha L.; Kocan, Richard M.

1984-03-01

The cost of conducting conventional chronic bioassays with every potentially toxic compound found in marine ecosystems is prohibitive; therefore short-term toxicity tests which can be used for rapid screening were developed. The tests employ cultured fish cells to measure lethal, sublethal or genotoxic effects of pure compounds and complex mixtures. The sensitivity of these tests has been proven under laboratory conditions; the following study used two of these tests, the anaphase aberration test and a cytotoxicity assay, under field conditions. Sediment was collected from 97 stations within Puget Sound, Washington. Serial washings of the sediment in methanol and dichloromethane yielded an organic extract which was dried, dissolved in DMSO and incubated as a series of dilutions with rainbow trout gonad (RTG-2) cells. The toxic effects of the extract were measured by examining the rate of cell proliferation and the percentage of damaged anaphase figures. Anaphase figures were considered to be abnormal if they exhibited non-disjunctions, chromosome fragments, or chromosome bridges. A second cell line (bluegill fry, BF-2) was also tested for cell proliferation and was included because, unlike the RTG-2 cell line, it contains little or no mixed function oxygenase activity. Of 97 stations tested, 35 showed no genotoxic activity, 42 showed high genotoxic activity (P≤.01) and the remainder were intermediate. Among the toxic sites were several deep water stations adjacent to municipal sewage outfalls and four urban waterways contaminated by industrial and municipal effluents. Extracts from areas that showed genotoxic effects also inhibited cell proliferation and were cytotoxic to RTG-2 cells. Few effects were noted in the MFO deficient BF-2 cells. Short term in vitro tests provide aquatic toxicologists with a versatile and cost effective tool for screening complex environments. Through these tests one can identify compounds or geographic regions that exhibit high cytotoxic or genotoxic potential.

Definition phase study of the grand tour missions

NASA Technical Reports Server (NTRS)

Simpson, J. A.; Meyer, P.

1972-01-01

The research to define an energetic particle experiment for the OPTGT-MJS missions is reported. The studies reported include: (1) the use of silicon dectectors for low energy, low flux level measurements in the presence of RTG radiation and trapped electrons, (2) high energy proton damage of lithium-drifted and surface barrier silicon detectors, (3) the gas Cerenkov counter, (4) systems for detection of trapped high-energy protons in the presence of trapped electrons, and (5) reliability and redundancy.

Materials property definition and generation for carbon-carbon and carbon phenolic materials

NASA Technical Reports Server (NTRS)

Canfield, A. R.; Mathis, J. R.; Starrett, H. S.; Koenig, J. R.

1987-01-01

A data base program to generate statistically significant material-property data for carbon-carbon and carbon phenolic materials to be used in designs of Space Shuttle is described. The program, which will provide data necessary for thermal and stress modeling of Shuttle nozzle and exit cone structures, includes evaluation of tension, compression, shear strength, shear modulus, thermal expansion, thermal conductivity, permeability, and emittance for both materials; the testing of carbon phenolic materials also includes CTE, off-gassing, pyrolysis, and RTG. Materials to be tested will be excised from Space Shuttle inlet, throat, and exit cone billets and modified involute carbon-carbon exit cones; coprocessed blocks, panels, and cylinders will also be tested.

Cassini's RTGs undergo mechanical and electrical verification tests in the PHSF

NASA Technical Reports Server (NTRS)

1997-01-01

Lockheed Martin Missile and Space Co. employees Joe Collingwood, at right, and Ken Dickinson retract pins in the storage base to release a radioisotope thermoelectric generator (RTG) in preparation for hoisting operations. This RTG and two others will be installed on the Cassini spacecraft for mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed by NASA's Jet Propulsion Laboratory.

KSC-97pc1065

NASA Image and Video Library

1997-07-18

Jet Propulsion Laboratory (JPL) workers prepare the installation cart (atop the platform) for removal of a radioisotope thermoelectric generator (RTG) from the adjacent Cassini spacecraft. This is the second of three RTGs being removed from Cassini after undergoing mechanical and electrical verification tests in the Payload Hazardous Servicing Facility. The third RTG to be removed is in background at left. The three RTGs will then be temporarily stored before being re-installed for flight. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate far from the Sun where solar power systems are not feasible. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL

RTG-History, the Curiosity, Voyager, and New Horizons

Science.gov Websites

solar system for many years. Prior to New Horizons, the Apollo missions to the Moon, the Viking missions Report, January 11, 1991--April 30, 1998, DOE Technical Report Download Adobe PDF Reader , August 1998

Pressurized Lunar Rover (PLR)

NASA Technical Reports Server (NTRS)

Creel, Kenneth; Frampton, Jeffrey; Honaker, David; Mcclure, Kerry; Zeinali, Mazyar; Bhardwaj, Manoj; Bulsara, Vatsal; Kokan, David; Shariff, Shaun; Svarverud, Eric

1992-01-01

The objective of this project was to design a manned pressurized lunar rover (PLR) for long-range transportation and for exploration of the lunar surface. The vehicle must be capable of operating on a 14-day mission, traveling within a radius of 500 km during a lunar day or within a 50-km radius during a lunar night. The vehicle must accommodate a nominal crew of four, support two 28-hour EVA's, and in case of emergency, support a crew of six when near the lunar base. A nominal speed of ten km/hr and capability of towing a trailer with a mass of two mt are required. Two preliminary designs have been developed by two independent student teams. The PLR 1 design proposes a seven meter long cylindrical main vehicle and a trailer which houses the power and heat rejection systems. The main vehicle carries the astronauts, life support systems, navigation and communication systems, lighting, robotic arms, tools, and equipment for exploratory experiments. The rover uses a simple mobility system with six wheels on the main vehicle and two on the trailer. The nonpressurized trailer contains a modular radioisotope thermoelectric generator (RTG) supplying 6.5 kW continuous power. A secondary energy storage for short-term peak power needs is provided by a bank of lithium-sulfur dioxide batteries. The life support system is partly a regenerative system with air and hygiene water being recycled. A layer of water inside the composite shell surrounds the command center allowing the center to be used as a safe haven during solar flares. The PLR 1 has a total mass of 6197 kg. It has a top speed of 18 km/hr and is capable of towing three metric tons, in addition to the RTG trailer. The PLR 2 configuration consists of two four-meter diameter, cylindrical hulls which are passively connected by a flexible passageway, resulting in the overall vehicle length of 11 m. The vehicle is driven by eight independently suspended wheels. The dual-cylinder concept allows articulated as well as double Ackermann steering. The primary power of 8 kW is supplied by a dynamic isotope system using a closed Brayton cycle with a xenon-hydrogen mixture as the working fluid. A sodium-sulfur battery serves as the secondary power source. Excess heat produced by the primary power system and other rover systems is rejected by radiators located on the top of the rear cylinder. The total mass of the PLR 2 is 7015 kg. Simplicity and low total weight have been the driving principles behind the design of PLR 1. The overall configuration consists of a 7-m-long, 3-m-diameter cylindrical main vehicle and a two-wheeled trailer. The cylinder of the main body is capped by eight-section, faceted, semi-hemispherical ends. The trailer contains the RTG power source and is not pressurized. The shell of the main body is constructed of a layered carbon fiber/foam/Kevlar sandwich structure. Included in the shell is a layer of water for radiation protection. The layer of water extends from the front of the rover over the crew compartment and creates a safe haven for the crew during a solar flare-up. The carbon fiber provides the majority of the strength and stiffness and the Kevlar provides protection from micrometeoroids. The Kevlar is covered with a gold foil and multi-layer insulation (MLI) to reduce radiation degradation and heat transfer through the wall. A thin thermoplastic layer seals the fiber and provides additional strength.

Pressurized Lunar Rover (PLR)

NASA Astrophysics Data System (ADS)

Creel, Kenneth; Frampton, Jeffrey; Honaker, David; McClure, Kerry; Zeinali, Mazyar; Bhardwaj, Manoj; Bulsara, Vatsal; Kokan, David; Shariff, Shaun; Svarverud, Eric

The objective of this project was to design a manned pressurized lunar rover (PLR) for long-range transportation and for exploration of the lunar surface. The vehicle must be capable of operating on a 14-day mission, traveling within a radius of 500 km during a lunar day or within a 50-km radius during a lunar night. The vehicle must accommodate a nominal crew of four, support two 28-hour EVA's, and in case of emergency, support a crew of six when near the lunar base. A nominal speed of ten km/hr and capability of towing a trailer with a mass of two mt are required. Two preliminary designs have been developed by two independent student teams. The PLR 1 design proposes a seven meter long cylindrical main vehicle and a trailer which houses the power and heat rejection systems. The main vehicle carries the astronauts, life support systems, navigation and communication systems, lighting, robotic arms, tools, and equipment for exploratory experiments. The rover uses a simple mobility system with six wheels on the main vehicle and two on the trailer. The nonpressurized trailer contains a modular radioisotope thermoelectric generator (RTG) supplying 6.5 kW continuous power. A secondary energy storage for short-term peak power needs is provided by a bank of lithium-sulfur dioxide batteries. The life support system is partly a regenerative system with air and hygiene water being recycled. A layer of water inside the composite shell surrounds the command center allowing the center to be used as a safe haven during solar flares. The PLR 1 has a total mass of 6197 kg. It has a top speed of 18 km/hr and is capable of towing three metric tons, in addition to the RTG trailer. The PLR 2 configuration consists of two four-meter diameter, cylindrical hulls which are passively connected by a flexible passageway, resulting in the overall vehicle length of 11 m. The vehicle is driven by eight independently suspended wheels. The dual-cylinder concept allows articulated as well as double Ackermann steering. The primary power of 8 kW is supplied by a dynamic isotope system using a closed Brayton cycle with a xenon-hydrogen mixture as the working fluid.

Nuclear energy technology

NASA Technical Reports Server (NTRS)

Buden, David

1992-01-01

An overview of space nuclear energy technologies is presented. The development and characteristics of radioisotope thermoelectric generators (RTG's) and space nuclear power reactors are discussed. In addition, the policy and issues related to public safety and the use of nuclear power sources in space are addressed.

Selenide isotope generator for the Galileo mission. Reliability program plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1978-10-01

The reliability program plan for the Selenide Isotope Generator (SIG) program is presented. It delineates the specific tasks that will be accomplished by Teledyne Energy Systems and its suppliers during design, development, fabrication and test of deliverable Radioisotopic Thermoelectric Generators (RTG), Electrical Heated Thermoelectric Generators (ETG) and associated Ground Support Equipment (GSE). The Plan is formulated in general accordance with procedures specified in DOE Reliability Engineering Program Requirements Publication No. SNS-2, dated June 17, 1974. The Reliability Program Plan presented herein defines the total reliability effort without further reference to Government Specifications. The reliability tasks to be accomplished are delineatedmore » herein and become the basis for contract compliance to the extent specified in the SIG contract Statement of Work.« less

Transcriptional regulation of respiration in yeast metabolizing differently repressive carbon substrates.

PubMed

Fendt, Sarah-Maria; Sauer, Uwe

2010-02-18

Depending on the carbon source, Saccharomyces cerevisiae displays various degrees of respiration. These range from complete respiration as in the case of ethanol, to almost complete fermentation, and thus very low degrees of respiration on glucose. While many key regulators are known for these extreme cases, we focus here on regulators that are relevant at intermediate levels of respiration. We address this question by linking the functional degree of respiration to transcriptional regulation via enzyme abundances. Specifically, we investigated aerobic batch cultures with the differently repressive carbon sources glucose, mannose, galactose and pyruvate. Based on 13C flux analysis, we found that the respiratory contribution to cellular energy production was largely absent on glucose and mannose, intermediate on galactose and highest on pyruvate. In vivo abundances of 40 respiratory enzymes were quantified by GFP-fusions under each condition. During growth on the partly and fully respired substrates galactose and pyruvate, several TCA cycle and respiratory chain enzymes were significantly up-regulated. From these enzyme levels and the known regulatory network structure, we determined the probability for a given transcription factor to cause the coordinated expression changes. The most probable transcription factors to regulate the different degrees of respiration were Gcr1p, Cat8p, the Rtg-proteins and the Hap-complex. For the latter three ones we confirmed their importance for respiration by quantifying the degree of respiration and biomass yields in the corresponding deletion strains. Cat8p is required for wild-type like respiration, independent of its known activation of gluconeogenic genes. The Rtg-proteins and the Hap-complex are essential for wild-type like respiration under partially respiratory conditions. Under fully respiratory conditions, the Hap-complex, but not the Rtg-proteins are essential for respiration.

Final safety analysis report for the Galileo Mission: Volume 2: Summary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) will be used as the prime source of electric power for the spacecraft on the Galileo mission. The use of radioactive material in these missions necessitates evaluations of the radiological risks that may be encountered by launch complex personnel and by the Earth's general population resulting from postulated malfunctions or failures occurring in the mission operations. The purpose of the Final Safety Analysis Report (FSAR) is to present the analyses and results of the latest evaluation of the nuclear safety potential of the GPHS-RTG as employed in the Galileo mission. Thismore » evaluation is an extension of earlier work that addressed the planned 1986 launch using the Space Shuttle Vehicle with the Centaur as the upper stage. This extended evaluation represents the launch by the Space Shuttle/IUS vehicle. The IUS stage has been selected as the vehicle to be used to boost the Galileo spacecraft into the Earth escape trajectory after the parking orbit is attained.« less

Hyperactivity with Agitative-Like Behavior in a Mouse Tauopathy Model.

PubMed

Jul, Pia; Volbracht, Christiane; de Jong, Inge E M; Helboe, Lone; Elvang, Anders Brandt; Pedersen, Jan Torleif

2016-01-01

Tauopathies, such as Alzheimer's disease (AD) and frontotemporal dementia (FTD), are characterized by formation of neurofibrillary tangles consisting of hyperphosphorylated tau. In addition to memory loss, patients experience behavioral symptoms such as agitation, aggression, depression, and insomnia. We explored the behavioral phenotype of a mouse model (rTg4510) carrying the human tau P301L mutation found in a familial form of FTD. We tested these mice in locomotor activity assays as well as in the Morris water maze to access spatial memory. In addition to cognitive impairments, rTg4510 mice exhibited a hyperactivity phenotype which correlated with progression of tau pathology and was dependent on P301L tau transgene expression. The hyperactive phenotype was characterized by significantly increased locomotor activity in a novel and in a simulated home cage environment together with a disturbed day/night cycle. The P301L-tau-dependent hyperactivity and agitative-like phenotype suggests that these mice may form a correlate to some of the behavioral disturbances observed in advanced AD and FTD.

Lunar Surface Stirling Power Systems Using Am-241

NASA Technical Reports Server (NTRS)

Schmitz, Paul C.; Penswick, L. Barry; Shaltens, Richard K.

2009-01-01

For many years NASA has used the decay of Pu-238 (in the form of the General Purpose Heat Source (GPHS)) as a heat source for Radioisotope Thermoelectric Generators (RTG), which have provided electrical power for many NASA missions. While RTG's have an impressive reliability record for the missions in which they have been used, their relatively low thermal to electric conversion efficiency (-5% efficiency) and the scarcity of Plutoinium-238 (Pu-238) has led NASA to consider other power conversion technologies. NASA is considering returning both robotic and human missions to the lunar surface and, because of the long lunar nights (14 earth days) isotope power systems are an attractive candidate to generate electrical power. NASA is currently developing the Advanced Stirling Radioisotope Generator (ASRG) as a candidate higher efficiency power system that produces greater than 160 watts with 2 GPHS modules at the beginning of life (BOL) (-30% efficiency). The ASRG uses the same Pu-238 GPHS modules, which are used in RTG, but by coupling them to a Stirling convertor provides a 4-fold reduction in the number of GPHS modules. This study considers the use of Americium 241 (Am-241) as a substitute for the Pu-238 in Stirling convertor based Radioisotope Power Systems (RPS) for power levels from 1 O's of watts to 5 kWe. The Am-241 is used as a replacement for the Pu-238 in GPHS modules. Depending on power level, different Stirling heat input and removal systems are modeled. It was found that substituting Am-241 GPHS modules into the ASRG reduces power output by about 1/5 while maintaining approximately the same system mass. In order to obtain the nominal 160 watts electrical output of the Pu-238 ASRG requires 10 Am-241 GPHS modules. Higher power systems require changing from conductive coupling heat input and removal from the Stirling convertor to either pumped loops or heat pipes. Liquid metal pumped loops are considered as the primary heat transportation on the hot end and water pumped loop/heat pipe radiator is considered for the heat rejection side for power levels above 1 kWe.

Venus high temperature atmospheric dropsonde and extreme-environment seismometer (HADES)

NASA Astrophysics Data System (ADS)

Boll, Nathan J.; Salazar, Denise; Stelter, Christopher J.; Landis, Geoffrey A.; Colozza, Anthony J.

2015-06-01

The atmospheric composition and geologic structure of Venus have been identified by the US National Research Council's Decadal Survey for Planetary Science as priority targets for scientific exploration; however, the high temperature and pressure at the surface, along with the highly corrosive chemistry of the Venus atmosphere, present significant obstacles to spacecraft design that have severely limited past and proposed landed missions. Following the methodology of the NASA Innovative Advanced Concepts (NIAC) proposal regime and the Collaborative Modeling and Parametric Assessment of Space Systems (COMPASS) design protocol, this paper presents a conceptual study and initial feasibility analysis for a Discovery-class Venus lander capable of an extended-duration mission at ambient temperature and pressure, incorporating emerging technologies within the field of high temperature electronics in combination with novel configurations of proven, high Technology Readiness Level (TRL) systems. Radioisotope Thermal Power (RTG) systems and silicon carbide (SiC) communications and data handling are examined in detail, and various high-temperature instruments are proposed, including a seismometer and an advanced photodiode imager. The study combines this technological analysis with proposals for a descent instrument package and a relay orbiter to demonstrate the viability of an integrated atmospheric and in-situ geologic exploratory mission that differs from previous proposals by greatly reducing the mass, power requirements, and cost, while achieving important scientific goals.

Venus High Temperature Atmospheric Dropsonde and Extreme-Environment Seismometer (HADES)

NASA Technical Reports Server (NTRS)

Boll, Nathan J.; Salazar, Denise; Stelter, Christopher J.; Landis, Geoffrey A.; Colozza, Anthony J.

2014-01-01

The atmospheric composition and geologic structure of Venus have been identified by the US National Research Council's Decadal Survey for Planetary Science as priority targets for scientific exploration, however the high temperature and pressure at the surface, along with the highly corrosive chemistry of the Venus atmosphere, present significant obstacles to spacecraft design that have severely limited past and proposed landed missions. Following the methodology of the NASA Innovative Advanced Concepts (NIAC) proposal regime and the Collaborative Modeling and Parametric Assessment of Space Systems (COMPASS) design protocol, this paper presents a conceptual study and initial feasibility analysis for a Discovery-class Venus lander capable of an extended-duration mission at ambient temperature and pressure, incorporating emerging technologies within the field of high temperature electronics in combination with novel configurations of proven, high Technology Readiness Level (TRL) systems. Radioisotope Thermal Power (RTG) systems and silicon carbide (SiC) communications and data handling are examined in detail, and various high-temperature instruments are proposed, including a seismometer and an advanced photodiode imager. The study combines this technological analysis with proposals for a descent instrument package and a relay orbiter to demonstrate the viability of an integrated atmospheric and in-situ geologic exploratory mission that differs from previous proposals by greatly reducing the mass, power requirements, and cost, while achieving important scientific goals.

NCEP SST Analysis

Science.gov Websites

Branches Global Climate & Weather Modeling Mesoscale Modeling Marine Modeling and Analysis Contact EMC , state and local government Web resources and services. Real-time, global, sea surface temperature (RTG_SST_HR) analysis For a regional map, click the desired area in the global SST analysis and anomaly maps

Results of an Internet-Based Dual-Frequency Global Differential GPS System

NASA Technical Reports Server (NTRS)

Muellerschoen, R.; Bertiger, W.; Lough, M.

2000-01-01

Observables from a global network of 18 GPS receivers are returned in real-time to JPL over the open Internet. 30 - 40 cm RSS global GPS orbits and precise dual-frequency GPS clocks are computed in real-time with JPL's Real Time Gipsy (RTG) software.

The Spencer Research Training Grant at the Penn Graduate School of Education: Implementation and Effects

ERIC Educational Resources Information Center

Kecskemethy, Thomas A.

2008-01-01

Background/Context: The Research Training Grant (RTG) program at the University of Pennsylvania's Graduate School of Education aimed to create strong research training experiences for predissertation fellows through generous financial aid, mentored research apprenticeships, and cocurricular experiences. Collectively these offerings sought to…

Individualized supervised resistance training during nebulization in adults with cystic fibrosis.

PubMed

Shaw, Ina; Kinsey, Janine E; Richards, Roxanne; Shaw, Brandon S

2016-01-01

Since dyspnea limits exercise adherence and intensity in cystic fibrosis (CF) patients, engaging in resistance training (RT), which causes less dyspnea than other exercise modalities, while using nebulizers could not only overcome this barrier, but also enhance long-term adaptations to treatment. The objective of this study was to examine the effects of RT during nebulization on spirometry, anthropometry, chest wall excursion, respiratory muscle strength and health-related quality of life (HRQOL). Fourteen male and female CF patients were assigned to a four-week, 20-minute, 5-day per week proof-of-concept RT group (RTG) (n=7) or non-exercising control group (CON) (n=7), with 3 CON patients later dropping out of the study. Patients performed whole body exercises for 3 sets of 10 reps using resistance bands, since such bands have previously demonstrated a greater effect on functional exercise capacity than conventional RT in lung patients. The RTG displayed significant (p≤0.05) increases in FEV 1 , FEV 1 /FVC, latissimusdorsi strength, pectoralis major clavicular portion strength, pectoralis major sternocostal portion strength and emotional and digestion HRQOL domains, while decreasing pectoralis minor strength on the left and social, body image and respiration HRQOL domains. This small scale proof-of-concept investigation demonstrates the multiple and simultaneous benefits of RT during nebulization in CF patients. The improvements in pulmonary measures are particularly promising especially since this study only made use of a four-week experimental period. This study provides an important alternative, time-saving treatment for the CF patient that does not add to the treatment burden of CF patients.

Comparative Cytotoxicity Study of Silver Nanoparticles (AgNPs) in a Variety of Rainbow Trout Cell Lines (RTL-W1, RTH-149, RTG-2) and Primary Hepatocytes

PubMed Central

Connolly, Mona; Fernandez-Cruz, Maria-Luisa; Quesada-Garcia, Alba; Alte, Luis; Segner, Helmut; Navas, Jose M.

2015-01-01

Among all classes of nanomaterials, silver nanoparticles (AgNPs) have potentially an important ecotoxicological impact, especially in freshwater environments. Fish are particularly susceptible to the toxic effects of silver ions and, with knowledge gaps regarding the contribution of dissolution and unique particle effects to AgNP toxicity, they represent a group of vulnerable organisms. Using cell lines (RTL-W1, RTH-149, RTG-2) and primary hepatocytes of rainbow trout (Oncorhynchus mykiss) as in vitro test systems, we assessed the cytotoxicity of the representative AgNP, NM-300K, and AgNO3 as an Ag+ ion source. Lack of AgNP interference with the cytotoxicity assays (AlamarBlue, CFDA-AM, NRU assay) and their simultaneous application point to the compatibility and usefulness of such a battery of assays. The RTH-149 and RTL-W1 liver cell lines exhibited similar sensitivity as primary hepatocytes towards AgNP toxicity. Leibovitz’s L-15 culture medium composition (high amino acid content) had an important influence on the behaviour and toxicity of AgNPs towards the RTL-W1 cell line. The obtained results demonstrate that, with careful consideration, such an in vitro approach can provide valuable toxicological data to be used in an integrated testing strategy for NM-300K risk assessment. PMID:26006119

Buried Object Classification using a Sediment Volume Imaging SAS and Electromagnetic Gradiometer

DTIC Science & Technology

2006-09-01

field data with simulated RTG data using AST’s in-house magnetic modeling tool EMAGINE . Given a set of input dipole moments, or pa- rameters to...approximate a moment by assuming the object is a prolate ellipsoid shell, EMAGINE uses Green’s func- tion formulations to generate three-component

The Impact of PERK on Posttraumatic Tauopathy in Alzheimer’s Disease

DTIC Science & Technology

2016-10-01

Complete imaging analyses (this work is completed continuously as injuries are performed) AIM2 4. Establish mouse cohorts for Aim 2 • rTg4510 transgenic ...animals to age to appropriate breeding age before we can perform any experiments. Changes that had a significant impact on expenditures No changes that

A Comparison of the Performance Capabilities of Radioisotope Energy Conversion Systems, Betavoltaic Cells, and other Nuclear Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinfelds, Eric V; Prelas, Mark A.; Sudarshan, Loyalka K.

2006-07-01

In this paper we compare the potential performance capabilities of several types of nuclear batteries to the Radioisotope Thermocouple Generators (RTG's) currently in use. There have been theoretical evaluations of, and some experimental testing of, several types of nuclear batteries including Radioisotope Energy Conversion Systems (RECS), Direct Energy Conversion (DEC) systems, and Betavoltaic Power Cells (BPC's). It has been theoretically shown, and to some extent experimentally demonstrated, that RECS, capacitive DEC systems, and possibly BPC's are all potentially capable of efficiencies well above the 9% maximum efficiency demonstrated to date in RTG's customized for deep space probe applications. Even thoughmore » RTG's have proven their reliability and have respectable power to mass ratios, it is desirable to attain efficiencies of at least 25% in typical applications. High fuel efficiency is needed to minimize the quantities of radioisotopic or nuclear fuels in the systems, to maximize power to mass ratios, and to minimize housing requirements. It has been shown that RECS can attain electric power generation efficiencies greater than 18% for devices which use Sr-90 fuel and where the accompanying material is less than roughly twice the mass of the Sr-90 fuel. Other radioisotopic fuels such as Pu-238 or Kr-85 can also be placed into RECS in order to attain efficiencies over 18%. With the likely exception of one fuel investigated by the authors, all of the promising candidates for RECS fuels can attain electric power to mass ratios greater than 15 W kg{sup -1}. It has been claimed recently [1] that the efficiency of tritium-fueled BPC's can be as high as 25%. While this is impressive and tritium has the benefit of being a 'soft' radioisotopic fuel, the silicon wafer that holds the tritium would have to be considerably more massive than the tritium contained within it and immediately adjacent to the wafer. Considering realistic mass requirements for the presence of silicon in the bulk of the wafer, a tritium cell would thus be limited to power to mass ratios <3 W kg{sup -1}. Even RECS designs with more energetic fuels and higher shielding burdens can attain >3 W kg{sup -1} and efficiencies exceeding 20%. Capacitive DEC systems can also offer significant benefits. With larger fuel quantities and larger dimensions, DEC systems can attain power efficiencies >50%. For small nuclear batteries of low or medium power, RECS appear highly desirable since the efficiency of a RECS does not vary with the amount of fuel present nor does it vary with temperature to any significant degree. (authors)« less

New Horizons Launch Contingency Effort

NASA Astrophysics Data System (ADS)

Chang, Yale; Lear, Matthew H.; McGrath, Brian E.; Heyler, Gene A.; Takashima, Naruhisa; Owings, W. Donald

2007-01-01

On 19 January 2006 at 2:00 PM EST, the NASA New Horizons spacecraft (SC) was launched from the Cape Canaveral Air Force Station (CCAFS), FL, onboard an Atlas V 551/Centaur/STAR™ 48B launch vehicle (LV) on a mission to explore the Pluto Charon planetary system and possibly other Kuiper Belt Objects. It carried a single Radioisotope Thermoelectric Generator (RTG). As part of the joint NASA/US Department of Energy (DOE) safety effort, contingency plans were prepared to address the unlikely events of launch accidents leading to a near-pad impact, a suborbital reentry, an orbital reentry, or a heliocentric orbit. As the implementing organization. The Johns Hopkins University Applied Physics Laboratory (JHU/APL) had expanded roles in the New Horizons launch contingency effort over those for the Cassini mission and Mars Exploration Rovers missions. The expanded tasks included participation in the Radiological Control Center (RADCC) at the Kennedy Space Center (KSC), preparation of contingency plans, coordination of space tracking assets, improved aerodynamics characterization of the RTG's 18 General Purpose Heat Source (GPHS) modules, and development of spacecraft and RTG reentry breakup analysis tools. Other JHU/APL tasks were prediction of the Earth impact footprints (ElFs) for the GPHS modules released during the atmospheric reentry (for purposes of notification and recovery), prediction of the time of SC reentry from a potential orbital decay, pre-launch dissemination of ballistic coefficients of various possible reentry configurations, and launch support of an Emergency Operations Center (EOC) on the JHU/APL campus. For the New Horizons launch, JHU/APL personnel at the RADCC and at the EOC were ready to implement any real-time launch contingency activities. A successful New Horizons launch and interplanetary injection precluded any further contingency actions. The New Horizons launch contingency was an interagency effort by several organizations. This paper describes JHU/APL's roles and responsibilities in the launch contingency effort, and the specific tasks to fulfill those responsibilities. The overall effort contributed to mission safety and demonstrated successful cooperation between several agencies.

Radioisotope thermal photovoltaic application of the GaSb solar cell

NASA Technical Reports Server (NTRS)

Morgan, M. D.; Horne, W. E.; Day, A. C.

1991-01-01

An examination of a RTVP (radioisotopic thermophotovoltaic) conceptual design has shown a high potential for power densities well above those achievable with radioisotopic thermoelectric generator (RTG) systems. An efficiency of 14.4 percent and system specific power of 9.25 watts/kg were predicted for a system with sixteen GPHS (general purpose heat source) sources operating at 1100 C. The models also showed a 500 watt system power by the strontium-90 isotope at 1200 C at an efficiency of 17.0 percent and a system specific power of 11.8 watts/kg. The key to this level of performance is a high-quality photovoltaic cell with narrow bandgap and a reflective rear contact. Recent work at Boeing on GaSb cells and transparent back GaAs cells indicate that such a cell is well within reach.

Toward a Vibrant Research Community in Education: Investing in Early-Career Scholars

ERIC Educational Resources Information Center

Young, Lauren Jones

2008-01-01

Background/Context: In 1994, the Spencer Foundation embarked on an ambitious experimental initiative to support the preparation of education researchers. Over the 13-year span of the Research Training Grant (RTG) program, the foundation made multiyear awards to more than a dozen leading institutions in the United States and South Africa. This…

Exploring the Investment: Four Universities' Experiences with the Spencer Foundation's Research Training Grant Program--A Retrospective

ERIC Educational Resources Information Center

Neumann, Anna; Pallas, Aaron; Peterson, Penelope

2008-01-01

Background: This article serves as a conclusion to a TCR special issue devoted to understanding the impact of the Spencer Foundation's Research Training Grant (RTG) initiative. We examine four case reports prepared by scholars at the University of Wisconsin-Madison, the University of Pennsylvania, the University of California at Los Angeles…

[Uncommon foreign body in a nose].

PubMed

Alagić-Smailbegović, Jasminka; Hadzić, Edina; Sutalo, Kamenko; Resić, Mudzahid

2007-01-01

Foreign body in the nose most frequently occurs in childhood. It could be of various origin, pieces of toys, paper and uncommon metal body. Consequences include one- sided nasal breathing problem, nasal secretion and in some cases pain and secretion become purulent. The aim of this paper is to present uncommon foreign body in the nose. RTG diagnosis and extraction are the methods of choice.

Development of a Multi-bus, Multi-source Reconfigurable Stirling Radioisotope Power System Test Bed

NASA Technical Reports Server (NTRS)

Coleman, Anthony S.

2004-01-01

The National Aeronautics and Space Administration (NASA) has typically used Radioisotope Thermoelectric Generators (RTG) as their source of electric power for deep space missions. A more efficient and potentially more cost effective alternative to the RTG, the high efficiency 110 watt Stirling Radioisotope Generator 110 (SRG110) is being developed by the Department of Energy (DOE), Lockheed Martin (LM), Stirling Technology Company (STC) and NASA Glenn Research Center (GRC). The SRG110 consists of two Stirling convertors (Stirling Engine and Linear Alternator) in a dual-opposed configuration, and two General Purpose Heat Source (GPHS) modules. Although Stirling convertors have been successfully operated as a power source for the utility grid and as a stand-alone portable generator, demonstration of the technology required to interconnect two Stirling convertors for a spacecraft power system has not been attempted. NASA GRC is developing a Power System Test Bed (PSTB) to evaluate the performance of a Stirling convertor in an integrated electrical power system application. This paper will describe the status of the PSTB and on-going activities pertaining to the PSTB in the NASA Thermal-Energy Conversion Branch of the Power and On-Board Propulsion Technology Division.

Thermoelectric generator testing and RTG degradation mechanisms evaluation. Progress report No. 33

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lockwood, A.; Stapfer, G.

1979-12-01

The n-type selenide legs after 10,600 hours continue to show agreement with the 3M Co. published data. In the ingradient testing after 11,378 hours the n-legs show comparable performance to the reported 3M data. The new design p-type legs were placed on test. The remaining MHW generator on test Q1-A has accumulated 19,567 hours and performance remains stable. Three 18 couple modules S/N-1, 2, and 3 previously tested at RCA were received for JPL test and evaluation. S/N-1 has 1700 hours testing at JPL with results indistinguishable from those at the end of RCA testing in 1977. The performances ofmore » LES 8/9 generators are following DEGRA predications after 31,824 hours. The performance of the Voyager 1 and 2 RTGs is reported after 19,577 hours and 20,122 hours of operation, respectively.« less

Realistic Specific Power Expectations for Advanced Radioisotope Power Systems

NASA Technical Reports Server (NTRS)

Mason, Lee S.

2006-01-01

Radioisotope Power Systems (RPS) are being considered for a wide range of future NASA space science and exploration missions. Generally, RPS offer the advantages of high reliability, long life, and predictable power production regardless of operating environment. Previous RPS, in the form of Radioisotope Thermoelectric Generators (RTG), have been used successfully on many NASA missions including Apollo, Viking, Voyager, and Galileo. NASA is currently evaluating design options for the next generation of RPS. Of particular interest is the use of advanced, higher efficiency power conversion to replace the previous thermoelectric devices. Higher efficiency reduces the quantity of radioisotope fuel and potentially improves the RPS specific power (watts per kilogram). Power conversion options include Segmented Thermoelectric (STE), Stirling, Brayton, and Thermophotovoltaic (TPV). This paper offers an analysis of the advanced 100 watt-class RPS options and provides credible projections for specific power. Based on the analysis presented, RPS specific power values greater than 10 W/kg appear unlikely.

Advanced Radioisotope Power System Enabled Titan Rover Concept with Inflatable Wheels

NASA Astrophysics Data System (ADS)

Balint, Tibor S.; Schriener, Timothy M.; Shirley, James H.

2006-01-01

The Decadal Survey identified Titan as one of the top priority science destinations in the large moons category, while NASA's proposed Design Reference Mission Set ranked a Titan in-situ explorer second, after a recommended Europa Geophysical Explorer mission. This paper discusses a Titan rover concept, enabled by a single advanced Radioisotope Power System that could provide about 110 We (BOL). The concept targets the smaller Flagship or potentially the New Frontiers mission class. This MSL class rover would traverse on four 1.5 m diameter inflatable wheels during its 3 years mission duration and would use as much design and flight heritage as possible to reduce mission cost. Direct to Earth communication would remove the need for a relay orbiter. Details on the strawman instrument payload, and rover subsystems are given for this science driven mission concept. In addition, power system trades between Advanced RTG, TPV, and Advanced-Stirling and Brayton RPSs are outlined. While many possible approaches exist for Titan in-situ exploration, the Titan rover concept presented here could provide a scientifically interesting and programmatically affordable solution.

ARPS Enabled Titan Rover Concept with Inflatable Wheels

NASA Technical Reports Server (NTRS)

Balint, Tibor S.; Schriener, Timothy M.; Shirley, James H.

2006-01-01

The Decadal Survey identified Titan as one of the top priority science destinations in the large moons category, while NASA's proposed Design Reference Mission Set ranked a Titan in-situ explorer second, after a recommended Europa Geophysical Observer mission. This paper discusses a Titan rover concept, enabled by a single advanced Radioisotope Power System that could provide about 110We (BOL). The concept targets the smaller Flagship or potentially the New Frontiers mission class. This MSL class rover would traverse on four 1.5 m diameter inflatable wheels during its 3 years mission duration and would use as much design and flight heritage as possible to reduce mission cost. Direct to Earth communication would remove the need for a relay orbiter. Details on the strawman instrument payload, and rover subsystems are given for this science driven mission concept. In addition, power system trades between Advanced RTG, TPV, and Advanced Stirling and Brayton Radioisotope Power Systems (RPS) are outlined. While many possible approaches exist for Titan in-situ exploration, the Titan rover concept presented here could provide a scientifically interesting and programmatically affordable solution.

Impact of Lake Okeechobee Sea Surface Temperatures on Numerical Predictions of Summertime Convective Systems over South Florida

NASA Technical Reports Server (NTRS)

Case, Jonathan L.; Splitt, Michael E.; Fuell, Kevin K.; Santos, Pablo; Lazarus, Steven M.; Jedlovec, Gary J.

2009-01-01

The NASA Short-term Prediction Research and Transition (SPoRT) Center, the Florida Institute of Technology, and the NOAA/NWS Weather Forecast Office at Miami, FL (MFL) are collaborating on a project to investigate the impact of using high-resolution, 2-km Moderate Resolution Imaging Spectroradiometer (MODIS) sea surface temperature (SST) composites within the Weather Research and Forecasting (WRF) prediction system. The NWS MFL is currently running WRF in real-time to support daily forecast operations, using the National Centers for Environmental Prediction Nonhydrostatic Mesoscale Model dynamical core within the NWS Science and Training Resource Center's Environmental Modeling System (EMS) software. Twenty-seven hour forecasts are run daily initialized at 0300, 0900, 1500, and 2100 UTC on a domain with 4-km grid spacing covering the southern half of Florida and adjacent waters of the Gulf of Mexico and Atlantic Ocean. The SSTs are initialized with the NCEP Real-Time Global (RTG) analyses at 1/12deg resolution. The project objective is to determine whether more accurate specification of the lower-boundary forcing over water using the MODIS SST composites within the 4-km WRF runs will result in improved sea fluxes and hence, more accurate e\\olutiono f coastal mesoscale circulations and the associated sensible weather elements. SPoRT conducted parallel WRF EMS runs from February to August 2007 identical to the operational runs at NWS MFL except for the use of MODIS SST composites in place of the RTG product as the initial and boundary conditions over water. During the course of this evaluation, an intriguing case was examined from 6 May 2007, in which lake breezes and convection around Lake Okeechobee evolved quite differently when using the high-resolution SPoRT MODIS SST composites versus the lower-resolution RTG SSTs. This paper will analyze the differences in the 6 May simulations, as well as examine other cases from the summer 2007 in which the WRF-simulated Lake Okeechobee breezes evolved differently due to the SST initialization. The effects on wind fields and precipitation systems will be emphasized, including validation against surface mesonet observations and Stage IV precipitation grids.

Radioisotope Stirling Generator Options for Pluto Fast Flyby Mission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schock, Alfred

The preceding paper described conceptual designs and analytical results for five Radioisotope Thermoelectric Generator (RTG) options for the Pluto Fast Flyby (PFF) mission, and the present paper describes three Radioisotope Stirling Generator (RSG) options for the same mission. The RSG options are based on essentially the same radioisotope heat source modules used in previously flown RTGs and on designs and analyses of a 75-watt free-piston Stirling engine produced by Mechanical Technology Incorporated (MTI) for NASA's Lewis Research Center. The integrated system design options presented were generated in a Fairchild Space study sponsored by the Department of Energy's Office of Specialmore » Applications, in support of ongoing PFF mission and spacecraft studies that the Jet Propulsion Laboratory (JPL) is conducting for the National Aeronautics and Space Administration (NASA). That study's NASA-directed goal is to reduce the spacecraft mass from its baseline value of 166 kg to ~110 kg, which implies a mass goal of less than 10 kg for a power source able to deliver 69 watts(e) at the end of the 9.2-year mission. In general, the Stirling options were found to be lighter than the thermoelectric options described in the preceding paper. But they are less mature, requiring more development, and entailing greater programmatic risk. The Stirling power system mass ranged from 7.3 kg (well below the 10-kg goal) for a non-redundant system to 11.3 kg for a redundant system able to maintain full power if one of its engines fails. In fact, the latter system could deliver as much as 115 watts(e) if desired by the mission planners. There are 2 copies in the file.« less

Reduced tillage and cover crops as a strategy for mitigating atmospheric CO2 increase through soil organic carbon sequestration in dry Mediterranean agroecosystems.

NASA Astrophysics Data System (ADS)

Almagro, María; Garcia-Franco, Noelia; de Vente, Joris; Boix-Fayos, Carolina; Díaz-Pereira, Elvira; Martínez-Mena, María

2016-04-01

The implementation of sustainable land management (SLM) practices in semiarid Mediterranean agroecosystems can be beneficial to maintain or enhance levels of soil organic carbon and mitigate current atmospheric CO2 increase. In this study, we assess the effects of different tillage treatments (conventional tillage (CT), reduced tillage (RT), reduced tillage combined with green manure (RTG), and no tillage (NT)) on soil CO2 efflux, aggregation and organic carbon stabilization in two semiarid organic rainfed almond (Prunus dulcis Mill., var. Ferragnes) orchards located in SE Spain Soil CO2 efflux, temperature and moisture were measured monthly between May 2012 and December 2014 (site 1), and between February 2013 and December 2014 (site 2). In site 1, soil CO2 efflux rates were also measured immediately following winter and spring tillage operations. Aboveground biomass inputs were estimated at the end of the growing season in each tillage treatment. Soil samples (0-15 cm) were collected in the rows between the trees (n=4) in October 2012. Four aggregate size classes were distinguished by sieving (large and small macroaggregates, free microaggregates, and free silt plus clay fraction), and the microaggregates occluded within macroaggregates (SMm) were isolated. Soil CO2efflux rates in all tillage treatments varied significantly during the year, following changes during the autumn, winter and early spring, or changes in soil moisture during late spring and summer. Repeated measures analyses of variance revealed that there were no significant differences in soil CO2 efflux between tillage treatments throughout the study period at both sites. Average annual values of C lost by soil respiration were slightly but not significantly higher under RT and RTG treatments (492 g C-CO2 m-2 yr-1) than under NT treatment (405 g C-CO2 m-2 yr-1) in site 1, while slightly but not significantly lower values were observed under RT and RTG treatments (468 and 439 g C-CO2 m-2 yr-1, respectively) than under CT treatment (399 g C-CO2 m-2 yr-1) in site 2. Tillage operations had a rapid but short-lived effect on soil CO2 efflux rates, with no significant influence on the annual soil CO2 emissions. The larger amounts of plant biomass incorporated into soil annually in the reduced tillage treatments compared to the conventional tillage treatment promoted soil aggregation and the physico-chemical soil organic carbon stabilization while soil CO2 emissions did not significantly increase. According to our results, reduced-tillage is strongly recommended as a beneficial SLM strategy for mitigating atmospheric CO2 increase through soil carbon sequestration and stabilization in semiarid Mediterranean agroecosystems.

Effects of two programs of exercise on body composition of adolescents with Down syndrome

PubMed Central

Seron, Bruna Barboza; Silva, Renan Alvarenga C.; Greguol, Márcia

2014-01-01

Objective: To investigate the effects of a 12 week aerobic and resistance exercise on body composition of adolescents with Down syndrome. Methods: A quasi-experimental study with 41 adolescents with Down syndrome, aged 15.5±2.7 years, divided into three groups: Aerobic Training Group (ATG; n=16), Resisted Training Group (RTG; n=15) and Control Group (CG; n=10). There were two types of training: aerobic, with intensity of 50-70% of the heart rate reserve 3 times/week, and resisted, with intensity of 12 maximum repetitions 2 times week. Both trainings were applied during a 12-week period. The percentage of fat evaluation was performed using plethysmography with Bod Pod(r) equipment. Waist circumference (WC), body weight and height were also measured. Paired t-test was used to compare variables before and after the exercise program. Results: The percentage of body fat did not change significantly for both groups that participated in the training intervention. However, CG showed a significant increase in this variable (31.3±7.2 versus 34.0±7.9). On the other hand, body mass index (BMI) and WC were significantly reduced for ATG (BMI: 27.0±4.4 and 26.5±4.2; WC: 87.3±11.1 and 86.2±9.7), while RTG and GC showed no differences in these variables. Conclusions: The aerobic and resisted training programs maintained body fat levels. ATG significantly reduced BMI and WC measures. Individuals who did not attend the training intervention increased their percentage of fat. PMID:24676196

Mars rover 1988 concepts

NASA Technical Reports Server (NTRS)

Pivirotto, Donna Shirley; Penn, Thomas J.; Dias, William C.

1989-01-01

Results of FY88 studies of a sample-collecting Mars rover are presented. A variety of rover concepts are discussed which include different technical approaches to rover functions. The performance of rovers with different levels of automation is described and compared to the science requirement for 20 to 40 km to be traversed on the Martian surface and for 100 rock and soil samples to be collected. The analysis shows that a considerable amount of automation in roving and sampling is required to meet this requirement. Additional performance evaluation shows that advanced RTG's producing 500 W and 350 WHr of battery storage are needed to supply the rover.

Vibration Testing of the Pluto/New Horizons Radioisotope Thermoelectric Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Charles D. Griffin

The Radioisotopic Thermal Generator (RTG) for the Pluto/New Horizons spacecraft was subjected to a flight dynamic acceptance test to demonstrate that it would perform successfully following launch. Seven RTGs of this type had been assembled and tested at Mound, Ohio from 1984 to 1997. This paper chronicles major events in establishing a new vibration test laboratory at the Idaho National Laboratory and the nineteen days of dynamic testing.

Development of advanced thermoelectric materials

NASA Technical Reports Server (NTRS)

1984-01-01

The development of an advanced thermoelectric material for radioisotope thermoelectric generator (RTG) applications is reported. A number of materials were explored. The bulk of the effort, however, was devoted to improving silicon germanium alloys by the addition of gallium phosphide, the synthesis and evaluation of lanthanum chrome sulfide and the formulation of various mixtures of lanthanum sulfide and chrome sulfide. It is found that each of these materials exhibits promise as a thermoelectric material.

Induction of EROD and BFCOD activities in tissues of barbel (Barbus callensis) from a water reservoir in Algeria.

PubMed

Habila, Safia; Leghouchi, Essaid; Valdehita, Ana; Bermejo-Nogales, Azucena; Khelili, Smail; Navas, José M

2017-08-01

EROD and BFCOD activities were measured in liver and gills of barbel (Barbus callensis, a native North African species) captured at Beni Haroun lake, the most important water reservoir in Algeria. This lake receives wastewater from different origins. Thus, we assessed the level of pollution through the induction of detoxification activities in tissues of barbel, evaluating simultaneously the suitability of this species to be used as a sentinel. Fish were collected between March 2015 and January 2016 at three locations taking into account the pollution sources and accessibility. In liver, EROD and BFCOD showed the highest induction in October specially in the location of the dam that received pollutants. In gills, only EROD, but not BFCOD, activity was detected. Maximal EROD induction was noted in samples from January. Fish cell lines (RTG-2 and PLHC-1) were exposed to sediments extracts collected at Beni Haroun lake and enzyme activities (EROD and BFCOD, respectively) were measured. Sediment extracts did not induce BFCOD activity. The EROD induction observed in RTG-2 cells was in line with the results observed in fish tissues. Our results suggest that the lake is at risk from pollution and that Barbus callensis is a good sentinel species. Copyright © 2017 Elsevier Inc. All rights reserved.

Bone structure regeneration after low induction magnetic field treatment in teeth chosen for extraction.

PubMed

Opalko, K; Dojs, A

2006-01-01

The aim of the work was to use and to evaluate the usefulness of the slow variable magnetic fields to aid the treatment of the teeth chosen for extraction. The marginal paradontium of periapical bone of teeth was in a state of extensive destruction. The teeth were chosen for extraction. 13 patients were chosen. 10 of them had with endo-perio changes and 3 suffered from full tooth luxation and had the teeth replanted. Those people were to have an extraction procedure or were declared as impossible to treat in other dental offices. Patients underwent non-aggressive skaling, endodontic treatment and were exposed to slow variable magnetic fields generated by Viofor JPS, accordingly to methods and parameters suggested by Department of Propaedeutics in Dentistry of Pomeranian Medical University in Szczecin. The process of healing of changes was evaluated radiologically. RTG done after 2 weeks and after 2 months were evaluated in respect of bone regeneration. They show the bone structure concentration. A RTG evaluation after half a year, two and three years show a preservation of the bone structure concentration. The use of slow variable magnetic fields contributed to bone structure regeneration and to preserve teeth with recorded endo-perio syndrome. Endodontic treatment of replanted teeth, aided with magnetostimulation has stopped the osteolisis process.

Logistical concepts associated with international shipments using the USA/9904/B(U)F RTG Transportation System (RTGTS)

NASA Astrophysics Data System (ADS)

Barklay, Chadwick D.; Miller, Roger G.; Pugh, Barry K.; Howell, Edwin I.

1997-01-01

Over the last 30 years, radioisotopes have provided heat from which electrical power is generated. For space missions, the isotope of choice has generally been 238PuO2, its long half-life making it ideal for supplying power to remote satellites and spacecraft like the Voyager, Pioneer, and Viking missions, as well as the recently launched Galileo and Ulysses missions, and the presently planned Cassini mission. Electric power for future space missions will be provided by either radioisotopic thermoelectric generators (RTG), radioisotope thermophotovoltaic systems (RTPV), alkali metal thermal to electrical conversion (AMTEC) systems, radioisotope Stirling systems, or a combination of these. The type of electrical power system has yet to be specified for the ``Pluto Express'' mission. However, the current plan does incorporate the use of Russian launch platforms for the spacecraft. The implied tasks associated with this plan require obtaining international certification for the transport of the radioisotopic power system, and resolving any logistical issues associated with the actual shipment of the selected radioisotopic power system. This paper presents a conceptual summary of the logistical considerations associated with shipping the selected radioisotopic power system using the USA/9904/B(U)F-85, Radioisotope Thermoelectric Generator Transportation System (RTGTS).

The Role of AhR in Breast Cancer Development

DTIC Science & Technology

2004-07-01

The renilla luciferase vectorphRL-TK (0.05 rtg) was co-transfected with firefly luciferase reporter constructs (0.1 ptg pGudLuc, 0.5-1.0 [tg wildtype...Glo Luciferase system (Promega, Madison, WI ) which allowed sequential reading of the firefly and renilla signals. Cells were lysed according to the...Madison, WI ). The renilla signal was read after quenching the firefly output, thus allowing normalization between sample wells. The normalized firefly

NEPP Update of Independent Single Event Upset Field Programmable Gate Array Testing

NASA Technical Reports Server (NTRS)

Berg, Melanie; Label, Kenneth; Campola, Michael; Pellish, Jonathan

2017-01-01

This presentation provides a NASA Electronic Parts and Packaging (NEPP) Program update of independent Single Event Upset (SEU) Field Programmable Gate Array (FPGA) testing including FPGA test guidelines, Microsemi RTG4 heavy-ion results, Xilinx Kintex-UltraScale heavy-ion results, Xilinx UltraScale+ single event effect (SEE) test plans, development of a new methodology for characterizing SEU system response, and NEPP involvement with FPGA security and trust.

Front End Analysis of Soldier Individual Power Systems

DTIC Science & Technology

1993-05-01

in the state-of-the-art MOD-GPHS-RTG, but with the fuel being polonium 210 , with a half life of 13.1.4 days, in the form of a gadolinium polonide (GdPo...allies, and industry to evaluate state-of-the-art technologies and integrate them into a system with synergistic improvement in combat effectiveness . The...Schemes ................................................... 79 Front End Analysis of Soldier Individual Power S LIST OF FIGURES I Effect of Mission

Temporal Expression Profiling Identifies Pathways Mediating Effect of Causal Variant on Phenotype

PubMed Central

Gupta, Saumya; Radhakrishnan, Aparna; Raharja-Liu, Pandu; Lin, Gen; Steinmetz, Lars M.; Gagneur, Julien; Sinha, Himanshu

2015-01-01

Even with identification of multiple causal genetic variants for common human diseases, understanding the molecular processes mediating the causal variants’ effect on the disease remains a challenge. This understanding is crucial for the development of therapeutic strategies to prevent and treat disease. While static profiling of gene expression is primarily used to get insights into the biological bases of diseases, it makes differentiating the causative from the correlative effects difficult, as the dynamics of the underlying biological processes are not monitored. Using yeast as a model, we studied genome-wide gene expression dynamics in the presence of a causal variant as the sole genetic determinant, and performed allele-specific functional validation to delineate the causal effects of the genetic variant on the phenotype. Here, we characterized the precise genetic effects of a functional MKT1 allelic variant in sporulation efficiency variation. A mathematical model describing meiotic landmark events and conditional activation of MKT1 expression during sporulation specified an early meiotic role of this variant. By analyzing the early meiotic genome-wide transcriptional response, we demonstrate an MKT1-dependent role of novel modulators, namely, RTG1/3, regulators of mitochondrial retrograde signaling, and DAL82, regulator of nitrogen starvation, in additively effecting sporulation efficiency. In the presence of functional MKT1 allele, better respiration during early sporulation was observed, which was dependent on the mitochondrial retrograde regulator, RTG3. Furthermore, our approach showed that MKT1 contributes to sporulation independent of Puf3, an RNA-binding protein that steady-state transcription profiling studies have suggested to mediate MKT1-pleiotropic effects during mitotic growth. These results uncover interesting regulatory links between meiosis and mitochondrial retrograde signaling. In this study, we highlight the advantage of analyzing allele-specific transcriptional dynamics of mediating genes. Applications in higher eukaryotes can be valuable for inferring causal molecular pathways underlying complex dynamic processes, such as development, physiology and disease progression. PMID:26039065

Acute cognitive impact of antiseizure drugs in naive rodents and corneal-kindled mice.

PubMed

Barker-Haliski, Melissa L; Vanegas, Fabiola; Mau, Matthew J; Underwood, Tristan K; White, H Steve

2016-09-01

Some antiseizure drugs (ASDs) are associated with cognitive liability in patients with epilepsy, thus ASDs without this risk would be preferred. Little comparative pharmacology exists with ASDs in preclinical models of cognition. Few pharmacologic studies exist on the acute effects in rodents with chronic seizures. Predicting risk for cognitive impact with preclinical models may supply valuable ASD differentiation data. ASDs (phenytoin [PHT]; carbamazepine [CBZ]; valproic acid [VPA]; lamotrigine [LTG]; phenobarbital [PB]; tiagabine [TGB]; retigabine [RTG]; topiramate [TPM]; and levetiracetam [LEV]) were administered equivalent to maximal electroshock median effective dose ([ED50]; mice, rats), or median dose necessary to elicit minimal motor impairment (median toxic dose [TD50]; rats). Cognition models with naive adult rodents were novel object/place recognition (NOPR) task with CF-1 mice, and Morris water maze (MWM) with Sprague-Dawley rats. Selected ASDs were also administered to rats prior to testing in an open field. The effect of chronic seizures and ASD administration on cognitive performance in NOPR was also determined with corneal-kindled mice. Mice that did not achieve kindling criterion (partially kindled) were included to examine the effect of electrical stimulation on cognitive performance. Sham-kindled and age-matched mice were also tested. No ASD (ED50) affected latency to locate the MWM platform; TD50 of PB, RTG, TPM, and VPA reduced this latency. In naive mice, CBZ and VPA (ED50) reduced time with the novel object. Of interest, no ASD (ED50) affected performance of fully kindled mice in NOPR, whereas CBZ and LEV improved cognitive performance of partially kindled mice. Standardized approaches to the preclinical evaluation of an ASD's potential cognitive impact are needed to inform drug development. This study demonstrated acute, dose- and model-dependent effects of therapeutically relevant doses of ASDs on cognitive performance of naive mice and rats, and corneal-kindled mice. This study highlights the challenge of predicting clinical adverse effects with preclinical models. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Final safety analysis report for the Galileo Mission: Volume 1, Reference design document

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The Galileo mission uses nuclear power sources called Radioisotope Thermoelectric Generators (RTGs) to provide the spacecraft's primary electrical power. Because these generators contain nuclear material, a Safety Analysis Report (SAR) is required. A preliminary SAR and an updated SAR were previously issued that provided an evolving status report on the safety analysis. As a result of the Challenger accident, the launch dates for both Galileo and Ulysses missions were later rescheduled for November 1989 and October 1990, respectively. The decision was made by agreement between the DOE and the NASA to have a revised safety evaluation and report (FSAR) preparedmore » on the basis of these revised vehicle accidents and environments. The results of this latest revised safety evaluation are presented in this document (Galileo FSAR). Volume I, this document, provides the background design information required to understand the analyses presented in Volumes II and III. It contains descriptions of the RTGs, the Galileo spacecraft, the Space Shuttle, the Inertial Upper Stage (IUS), the trajectory and flight characteristics including flight contingency modes, and the launch site. There are two appendices in Volume I which provide detailed material properties for the RTG.« less

GPHS-RTG performance on the Galileo mission

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hemler, R.J.; Cockfield, R.D.

The Galileo spacecraft, launched in October, 1989, is powered by two General Purpose Heat source-Radioisotope Thermoelectric Generator (GPHS-RTGs). These RTGs were designed, built, and tested by General Electric under contract from the Office of Special Applications of the Department of Energy (DOE). Isotope heat source installation and additional testing of these RTGs were performed at DOE's EG G Mound Facility in Miamisburg, Ohio. This paper provides a report on performance of the RTGs during launch and the early phases of the eight year Galileo mission.The effect of long term storage of the RTGs on power output, since the originally scheduledmore » launch data in May, 1986, will be dicussed, including the effects of helium buildup and subsequent purging with xenon. The RTGs performed as expected during the launch transient, met all specified power requirements for Beginning of Mission (BOM), and continue to follow prediced performance characteristics during the first year of the Galileo mission.« less

Solar cell design for avoiding LILT degradation. [low intensity, low temperature

NASA Technical Reports Server (NTRS)

Stella, P. M.; Ctorry, G. T.

1987-01-01

Growing concerns about radioisotope thermoelectric generator (RTG) performance potential, cost, safety, and availability have renewed interest in utilizing photovoltaic energy conversion for future JPL interplanetary missions such as the Mariner Mark II set. Although lightweight solar array technology has advanced to the point where it would appear to provide an alternative power source, anomalous silicon cell curve shape degradation at conditions of low intensity and low temperature (LILT) severely restricts photovoltaic applications for missions beyond 3 AU solar distance. In order to extend photovoltaic applications to distances of 5 AU, ways to minimize the deleterious impact of LILT cell degradation were investigated. These investigations have ranged from consideration of individual cell selection for LILT behavior to the examination of methods for reducing or eliminating cell LILT degradation by modifying the cell processing. Use of a partial oxide barrier between the cell n+ contacts and the silicon has been shown to reduce significantly both the occurrence and magnitude of the LILT degradation.

Preliminary test results from a free-piston Stirling engine technology demonstration program to support advanced radioisotope space power applications

NASA Astrophysics Data System (ADS)

White, Maurice A.; Qiu, Songgang; Augenblick, Jack E.

2000-01-01

Free-piston Stirling engines offer a relatively mature, proven, long-life technology that is well-suited for advanced, high-efficiency radioisotope space power systems. Contracts from DOE and NASA are being conducted by Stirling Technology Company (STC) for the purpose of demonstrating the Stirling technology in a configuration and power level that is representative of an eventual space power system. The long-term objective is to develop a power system with an efficiency exceeding 20% that can function with a high degree of reliability for up to 15 years on deep space missions. The current technology demonstration convertors (TDC's) are completing shakedown testing and have recently demonstrated performance levels that are virtually identical to projections made during the preliminary design phase. This paper describes preliminary test results for power output, efficiency, and vibration levels. These early results demonstrate the ability of the free-piston Stirling technology to exceed objectives by approximately quadrupling the efficiency of conventional radioisotope thermoelectric generators (RTG's). .

Thermal Expansion Studies of Selected High Temperature Thermoelectric Materials

NASA Technical Reports Server (NTRS)

Ravi, Vilupanur; Firdosy, Samad; Caillat, Thierry; Brandon, Erik; Van Der Walde, Keith; Maricic, Lina; Sayir, Ali

2008-01-01

Radioisotope thermoelectric generators (RTGs) generate electrical power by converting the heat released from the nuclear decay of radioactive isotopes (typically plutonium-238) into electricity using a thermoelectric converter. RTGs have been successfully used to power a number of space missions and have demonstrated their reliability over an extended period of time (tens of years) and are compact, rugged, radiation resistant, scalable, and produce no noise, vibration or torque during operation. System conversion efficiency for state-of-practice RTGs is about 6% and specific power less than or equal to 5.1 W/kg. Higher specific power would result in more on-board power for the same RTG mass, or less RTG mass for the same on-board power. The Jet Propulsion Laboratory has been leading, under the advanced thermoelectric converter (ATEC) project, the development of new high-temperature thermoelectric materials and components for integration into advanced, more efficient RTGs. Thermoelectric materials investigated to date include skutterudites, the Yb14MnSb11 compound, and SiGe alloys. The development of long-lived thermoelectric couples based on some of these materials has been initiated and is assisted by a thermo-mechanical stress analysis to ensure that all stresses under both fabrication and operation conditions will be within yield limits for those materials. Several physical parameters are needed as input to this analysis. Among those parameters, the coefficient of thermal expansion (CTE) is critically important. Thermal expansion coefficient measurements of several thermoelectric materials under consideration for ATEC are described in this paper. The stress response at the interfaces in material stacks subjected to changes in temperature is discussed, drawing on work from the literature and project-specific tools developed here. The degree of CTE mismatch and the associated effect on the formation of stress is highlighted.

Altered Intrinsic Pyramidal Neuron Properties and Pathway-Specific Synaptic Dysfunction Underlie Aberrant Hippocampal Network Function in a Mouse Model of Tauopathy

PubMed Central

Booth, Clair A.; Witton, Jonathan; Nowacki, Jakub; Tsaneva-Atanasova, Krasimira; Jones, Matthew W.; Randall, Andrew D.

2016-01-01

The formation and deposition of tau protein aggregates is proposed to contribute to cognitive impairments in dementia by disrupting neuronal function in brain regions, including the hippocampus. We used a battery of in vivo and in vitro electrophysiological recordings in the rTg4510 transgenic mouse model, which overexpresses a mutant form of human tau protein, to investigate the effects of tau pathology on hippocampal neuronal function in area CA1 of 7- to 8-month-old mice, an age point at which rTg4510 animals exhibit advanced tau pathology and progressive neurodegeneration. In vitro recordings revealed shifted theta-frequency resonance properties of CA1 pyramidal neurons, deficits in synaptic transmission at Schaffer collateral synapses, and blunted plasticity and imbalanced inhibition at temporoammonic synapses. These changes were associated with aberrant CA1 network oscillations, pyramidal neuron bursting, and spatial information coding in vivo. Our findings relate tauopathy-associated changes in cellular neurophysiology to altered behavior-dependent network function. SIGNIFICANCE STATEMENT Dementia is characterized by the loss of learning and memory ability. The deposition of tau protein aggregates in the brain is a pathological hallmark of dementia; and the hippocampus, a brain structure known to be critical in processing learning and memory, is one of the first and most heavily affected regions. Our results show that, in area CA1 of hippocampus, a region involved in spatial learning and memory, tau pathology is associated with specific disturbances in synaptic, cellular, and network-level function, culminating in the aberrant encoding of spatial information and spatial memory impairment. These studies identify several novel ways in which hippocampal information processing may be disrupted in dementia, which may provide targets for future therapeutic intervention. PMID:26758828

Altered Intrinsic Pyramidal Neuron Properties and Pathway-Specific Synaptic Dysfunction Underlie Aberrant Hippocampal Network Function in a Mouse Model of Tauopathy.

PubMed

Booth, Clair A; Witton, Jonathan; Nowacki, Jakub; Tsaneva-Atanasova, Krasimira; Jones, Matthew W; Randall, Andrew D; Brown, Jonathan T

2016-01-13

The formation and deposition of tau protein aggregates is proposed to contribute to cognitive impairments in dementia by disrupting neuronal function in brain regions, including the hippocampus. We used a battery of in vivo and in vitro electrophysiological recordings in the rTg4510 transgenic mouse model, which overexpresses a mutant form of human tau protein, to investigate the effects of tau pathology on hippocampal neuronal function in area CA1 of 7- to 8-month-old mice, an age point at which rTg4510 animals exhibit advanced tau pathology and progressive neurodegeneration. In vitro recordings revealed shifted theta-frequency resonance properties of CA1 pyramidal neurons, deficits in synaptic transmission at Schaffer collateral synapses, and blunted plasticity and imbalanced inhibition at temporoammonic synapses. These changes were associated with aberrant CA1 network oscillations, pyramidal neuron bursting, and spatial information coding in vivo. Our findings relate tauopathy-associated changes in cellular neurophysiology to altered behavior-dependent network function. Dementia is characterized by the loss of learning and memory ability. The deposition of tau protein aggregates in the brain is a pathological hallmark of dementia; and the hippocampus, a brain structure known to be critical in processing learning and memory, is one of the first and most heavily affected regions. Our results show that, in area CA1 of hippocampus, a region involved in spatial learning and memory, tau pathology is associated with specific disturbances in synaptic, cellular, and network-level function, culminating in the aberrant encoding of spatial information and spatial memory impairment. These studies identify several novel ways in which hippocampal information processing may be disrupted in dementia, which may provide targets for future therapeutic intervention. Copyright © 2016 Booth, Witton et al.

Characterization of Pu-238 Heat Source Granule Containment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richardson, Paul Dean II; Sanchez, Joey Leo; Wall, Angelique Dinorah

The Milliwatt Radioisotopic Themoelectric Generator (RTG) provides power for permissive-action links. Essentially these are nuclear batteries that convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of 238Pu, in the form of 238PuO 2 granules. The granules are contained by 3 layers of encapsulation. A thin T-111 liner surrounds the 238PuO 2 granules and protects the second layer (strength member) from exposure to the fuel granules. An outer layer of Hastalloy-C protects the T-111 from oxygen embrittlement. The T-111 strength member is considered the critical component in thismore » 238PuO 2 containment system. Any compromise in the strength member seen during destructive testing required by the RTG surveillance program is characterized. The T-111 strength member is characterized through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in the Secondary Electron mode to reveal possible grain boundary deformation and/or cracking in the region of the strength member weld. Deformation and cracking uncovered by SEM are further characterized by Metallography. Metallography sections are mounted and polished, observed using optical microscopy, then documented in the form of microphotographs. SEM mat further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray spectroscopy (EDS).« less

Dysphagia Causes Symptom Fluctuations after Oral L-DOPA Treatment in a Patient with Parkinson Disease.

PubMed

Sato, Hiromasa; Yamamoto, Toshiyuki; Sato, Masako; Furusawa, Yoshihiko; Murata, Miho

2018-01-01

The causes of "delayed-on" and "no-on" phenomena in Parkinson disease (PD) are thought to have some impact on the progress of L-DOPA from the time of ingestion until it reaches the brain and is converted to dopamine. Dysphagia can cause fluctuating symptom expression in L-DOPA therapy for PD. A 69-year-old man with PD presented with "delayed-on" and "no-on" phenomena. The patient developed a gait disorder at age 60 years, and he began coughing on his food during breakfast at age 64 years. Even though he was independent in daily life, he could not eat because of dysphagia in an "off" state. Videofluoroscopic examination of swallowing in an "off" state revealed bradykinesia of the tongue and the retention of tablets in the epiglottic vallecula. We trained him to keep his tongue in strong contact with the upper incisors before swallowing. After rehabilitation of dysphagia, the frequency of "delayed-on" and "no-on" phenomena decreased, and his peak L-DOPA plasma concentration was elevated. Additionally, transdermal rotigotine (RTG) was initiated at a maintenance dose of 9.0 mg. The patient reported improvement in swallowing, and the frequency of "no-on" phenomena decreased. In PD patients, the "no-on" phenomenon can be caused by posterior contractile dysfunction of the tongue, and it can be improved with training of the tongue and transdermal RTG administration.

Step length after discrete perturbation predicts accidental falls and fall-related injury in elderly people with a range of peripheral neuropathy.

PubMed

Allet, Lara; Kim, Hogene; Ashton-Miller, James; De Mott, Trina; Richardson, James K

2014-01-01

Distal symmetric polyneuropathy increases fall risk due to inability to cope with perturbations. We aimed to 1) identify the frontal plane lower limb sensorimotor functions which are necessary for robustness to a discrete, underfoot perturbation during gait; and 2) determine whether changes in the post-perturbed step parameters could distinguish between fallers and non fallers. Forty-two subjects (16 healthy old and 26 with diabetic PN) participated. Frontal plane lower limb sensorimotor functions were determined using established laboratory-based techniques. The subjects' most extreme alterations in step width or step length in response to a perturbation were measured. In addition, falls and fall-related injuries were prospectively recorded. Ankle proprioceptive threshold (APrT; p=.025) and hip abduction rate of torque generation (RTG; p=.041) independently predicted extreme step length after medial perturbation, with precise APrT and greater hip RTG allowing maintenance of step length. Injured subjects demonstrated greater extreme step length changes after medial perturbation than non-injured subjects (percent change = 18.5 ± 9.2 vs. 11.3 ± 4.57; p = .01). The ability to rapidly generate frontal plane hip strength and/or precisely perceive motion at the ankle is needed to maintain a normal step length after perturbation, a parameter which distinguishes between subjects sustaining a fall-related injury and those who did not. © 2014.

Fish cell lines as a tool for the ecotoxicity assessment and ranking of engineered nanomaterials.

PubMed

Bermejo-Nogales, A; Fernández-Cruz, M L; Navas, J M

2017-11-01

Risk assessment of engineered nanomaterials (ENMs) is being hindered by the sheer production volume of these materials. In this regard, the grouping and ranking of ENMs appears as a promising strategy. Here we sought to evaluate the usefulness of in vitro systems based on fish cell lines for ranking a set of ENMs on the basis of their cytotoxicity. We used the topminnow (Poeciliopsis lucida) liver cell line (PLHC-1) and the rainbow trout (Oncorhynchus mykiss) fibroblast-like gonadal cell line (RTG-2). ENMs were obtained from the EU Joint Research Centre repository. The size frequency distribution of ENM suspensions in cell culture media was characterized. Cytotoxicity was evaluated after 24 h of exposure. PLHC-1 cells exhibited higher sensitivity to the ENMs than RTG-2 cells. ZnO-NM was found to exert toxicity mainly by altering lysosome function and metabolic activity, while multi-walled carbon nanotubes (MWCNTs) caused plasma membrane disruption at high concentrations. The hazard ranking for toxicity (ZnO-NM > MWCNT ≥ CeO 2 -NM = SiO 2 -NM) was inversely related to the ranking in size detected in culture medium. Our findings reveal the suitability of fish cell lines for establishing hazard rankings of ENMs in the framework of integrated approaches to testing and assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

Step length after discrete perturbation predicts accidental falls and fall-related injury in elderly people with a range of peripheral neuropathy

PubMed Central

Allet, L; Kim, H; Ashton-Miller, JA; De Mott, T; Richardson, JK

2013-01-01

Aims Distal symmetric polyneuropathy increases fall risk due to inability to cope with perturbations. We aimed to 1) identify the frontal plane lower limb sensorimotor functions which are necessary for robustness to a discrete, underfoot perturbation during gait; and 2) determine whether changes in the post-perturbed step parameters could distinguish between fallers and non fallers. Methods Forty-two subjects (16 healthy old and 26 with diabetic PN) participated. Frontal plane lower limb sensorimotor functions were determined using established laboratory-based techniques. The subjects' most extreme alterations in step width or step length in response to a perturbation were measured. In addition, falls and fall-related injuries were prospectively recorded. Results Ankle proprioceptive threshold (APrT; p=.025) and hip abduction rate of torque generation (RTG; p=.041) independently predicted extreme step length after medial perturbation, with precise APrT and greater hip RTG allowing maintenance of step length. Fallers demonstrated greater extreme step length changes after medial perturbation than non fallers (percent change = 16.41±8.42 vs 11.0±4.95; p=.06) Conclusions The ability to rapidly generate frontal plane hip strength and/or precisely perceive motion at the ankle is needed to maintain a normal step length after perturbation, a parameter, which distinguishes between fallers and non fallers. PMID:24183899

A Multi-Season Study of the Effects of MODIS Sea-Surface Temperatures on Operational WRF Forecasts at NWS Miami, FL

NASA Technical Reports Server (NTRS)

Case, Jonathan L.; Santos, Pablo; Lazarus, Steven M.; Splitt, Michael E.; Haines, Stephanie L.; Dembek, Scott R.; Lapenta, William M.

2008-01-01

Studies at the Short-term Prediction Research and Transition (SPORT) Center have suggested that the use of Moderate Resolution Imaging Spectroradiometer (MODIS) sea-surface temperature (SST) composites in regional weather forecast models can have a significant positive impact on short-term numerical weather prediction in coastal regions. Recent work by LaCasse et al (2007, Monthly Weather Review) highlights lower atmospheric differences in regional numerical simulations over the Florida offshore waters using 2-km SST composites derived from the MODIS instrument aboard the polar-orbiting Aqua and Terra Earth Observing System satellites. To help quantify the value of this impact on NWS Weather Forecast Offices (WFOs), the SPORT Center and the NWS WFO at Miami, FL (MIA) are collaborating on a project to investigate the impact of using the high-resolution MODIS SST fields within the Weather Research and Forecasting (WRF) prediction system. The project's goal is to determine whether more accurate specification of the lower-boundary forcing within WRF will result in improved land/sea fluxes and hence, more accurate evolution of coastal mesoscale circulations and the associated sensible weather elements. The NWS MIA is currently running WRF in real-time to support daily forecast operations, using the National Centers for Environmental Prediction Nonhydrostatic Mesoscale Model dynamical core within the NWS Science and Training Resource Center's Environmental Modeling System (EMS) software. Twenty-seven hour forecasts are run dally initialized at 0300, 0900, 1500, and 2100 UTC on a domain with 4-km grid spacing covering the southern half of Florida and adjacent waters of the Gulf of Mexico and Atlantic Ocean. Each model run is initialized using the Local Analysis and Prediction System (LAPS) analyses available in AWIPS. The SSTs are initialized with the NCEP Real-Time Global (RTG) analyses at 1/12deg resolution (approx.9 km); however, the RTG product does not exhibit fine-scale details consistent with its grid resolution. SPORT is conducting parallel WRF EMS runs identical to the operational runs at NWS MIA except for the use of MODIS SST composites in place of the RTG product as the initial and boundary conditions over water, The MODIS SST composites for initializing the SPORT WRF runs are generated on a 2-km grid four times daily at 0400, 0700, 1600, and 1900 UTC, based on the times of the overhead passes of the Aqua and Terra satellites. The incorporation of the MODIS SST data into the SPORT WRF runs is staggered such that SSTs are updated with a new composite every six hours in each of the WRF runs. From mid-February to July 2007, over 500 parallel WRF simulations have been collected for analysis and verification. This paper will present verification results comparing the NWS MIA operational WRF runs to the SPORT experimental runs, and highlight any substantial differences noted in the predicted mesoscale phenomena for specific cases.

Awareness of Emerging Wireless Technologies: Ad-hoc and Personal Area Networks Standards and Emerging Technologies (Sensibilisation a l’emergence des technologies sans fil: technologies emergeantes et normes de reseaux personnels et ad-hoc)

DTIC Science & Technology

2007-04-01

for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data...Control Organization NRL Navy Research Laboratory nrtPS Non-real- time Polling Services OFDM Orthogonal frequency division multiplex OFDMA...Routeur IDentifier RTG RTO Task Group RTO Research & Technology Organization rtPS Real- time Polling Services SC Single-carrier modulation

Toward Intelligent Autonomous Agents for Cyber Defense: Report of the 2017 Workshop by the North Atlantic Treaty Organization (NATO) Research Group IST-152 RTG

DTIC Science & Technology

2018-04-18

Significant research is currently conducted on dynamic learning and threat detection. However, this work is held back by gaps in validation methods ...and network path rotation (e.g., Stream Splitting MTD). Agents can also employ various cyber-deception methods , including direct observation hiding...ARL-SR-0395 ● APR 2018 US Army Research Laboratory Toward Intelligent Autonomous Agents for Cyber Defense: Report of the 2017

Toward Intelligent Autonomous Agents for Cyber Defense: Report of the 2017 Workshop by the North Atlantic Treaty Organization (NATO) Research Group IST-152-RTG

DTIC Science & Technology

2018-04-01

Significant research is currently conducted on dynamic learning and threat detection. However, this work is held back by gaps in validation methods ...and network path rotation (e.g., Stream Splitting MTD). Agents can also employ various cyber-deception methods , including direct observation hiding...ARL-SR-0395 ● APR 2018 US Army Research Laboratory Toward Intelligent Autonomous Agents for Cyber Defense: Report of the 2017

Analysis, optimization, and assessment of radioisotope thermophotovoltaic system design for an illustrative space mission

NASA Astrophysics Data System (ADS)

Schock, A.; Mukunda, M.; Or, C.; Summers, G.

1995-01-01

A companion paper presented at this conference described the design of a Radioisotope Thermophotovoltaic (RTPV) Generator for an illustrative space mission (Pluto Fast Flyby). It presented a detailed design of an integrated system consisting of a radioisotope heat source, a thermophotovoltaic converter, and an optimized heat rejection system. The present paper describes the thermal, electrical, and structural analyses which led to that optimized design, and compares the computed RTPV performance to that of a Radioisotope Thermoelectric Generator (RTG) designed for the same mission. RTPVs are of course much less mature than RTGs, but our results indicate that—when fully developed—they could result in a 60% reduction of the heat source's mass, cost, and fuel loading, a 50% reduction of generator mass, a tripling of the power system's specific power, and a quadrupling of its efficiency. The paper concludes by briefly summarizing the RTPV's current technology status and assessing its potential applicability for the PFF mission. For other power systems (e.g., RTGs), demonstrating their flight readiness for a long mission is a very time-consuming process to determine the long-term effect of temperature-induced degradation mechanisms. But for the case of the described RTPV design, the paper lists a number of factors, primarily its cold (0 to 10 °C) converter temperature, that may greatly reduce the need for long-term tests to demonstrate generator lifetime. In any event, our analytical results suggest that the RTPV generator, when developed by DOE and/or NASA, would be quite valuable not only for the Pluto mission but also for other future missions requiring small, long-lived, low-mass generators.

[Compression fracture of a fragile lumbar vertebrae as a cause of low back pain].

PubMed

Ostojić, Zdenko; Ostojić, Ljerka; Pehar, Zoran; Ceramida, Meliha; Letica, Ludvih

2002-01-01

The patient felt sharp back lumbal pain while lifting heavy object in flexion position of the back. Rtg showed compressive fracture of L2. MRI showed secondary posttraumatic edema around compressive fracture of the body of L2. The compressive fracture was caused by intracorporal haemangiome of L2. After six months we had spontaneous sanation of heamgiome. Regarding to the therapy only electromagnetotherapy was used as well as programme of kinezitherapy given according to the condition of the body of L2.

The Science Behind 'The Martian' - Staying Warm on Mars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wham, Bob; Ulrich, George

Set in the not-too-distant future, “The Martian” is the story of an astronaut stranded on Mars who has to rely on his own wit and ingenuity to survive the planet’s hostile conditions. If Mark Watney’s mission were real, Oak Ridge National Laboratory would be playing a vital role in his survival, as it would be the sole source of the Plutonium-238 needed for the RTG, as well as the fuel’s containment material in the form of iridium clad vent sets.

Explicit Pore Pressure Material Model in Carbon-Cloth Phenolic

NASA Technical Reports Server (NTRS)

Gutierrez-Lemini, Danton; Ehle, Curt

2003-01-01

An explicit material model that uses predicted pressure in the pores of a carbon-cloth phenolic (CCP) composite has been developed. This model is intended to be used within a finite-element model to predict phenomena specific to CCP components of solid-fuel-rocket nozzles subjected to high operating temperatures and to mechanical stresses that can be great enough to cause structural failures. Phenomena that can be predicted with the help of this model include failures of specimens in restrained-thermal-growth (RTG) tests, pocketing erosion, and ply lifting

A nuclear localization of the infectious haematopoietic necrosis virus NV protein is necessary for optimal viral growth

USGS Publications Warehouse

Choi, M.K.; Moon, C.H.; Ko, M.S.; Lee, U.-H.; Cho, W.; Cha, S.J.; Do, J.W.; Heo, G.J.; Jeong, S.G.; Hahm, Y.S.; Harmache, A.; Bremont, M.; Kurath, G.; Park, J.-W.

2011-01-01

The nonvirion (NV) protein of infectious hematopoietic necrosis virus (IHNV) has been previously reported to be essential for efficient growth and pathogenicity of IHNV. However, little is known about the mechanism by which the NV supports the viral growth. In this study, cellular localization of NV and its role in IHNV growth in host cells was investigated. Through transient transfection in RTG-2 cells of NV fused to green fluorescent protein (GFP), a nuclear localization of NV was demonstrated. Deletion analyses showed that the 32EGDL35 residues were essential for nuclear localization of NV protein, and fusion of these 4 amino acids to GFP directed its transport to the nucleus. We generated a recombinant IHNV, rIHNV-NV-ΔEGDL in which the 32EGDL35 was deleted from the NV. rIHNVs with wild-type NV (rIHNV-NV) or with the NV gene replaced with GFP (rIHNV-ΔNV-GFP) were used as controls. RTG-2 cells infected with rIHNV-ΔNV-GFP and rIHNV-NV-ΔEGDL yielded 12- and 5-fold less infectious virion, respectively, than wild type rIHNV-infected cells at 48 h post-infection (p.i.). While treatment with poly I:C at 24 h p.i. did not inhibit replication of wild-type rIHNVs, replication rates of rIHNV-ΔNV-GFP and rIHNV-NV-ΔEGDL were inhibited by poly I:C. In addition, both rIHNV-ΔNV and rIHNV-NV-ΔEGDL induced higher levels of expressions of both IFN1 and Mx1 than wild-type rIHNV. These data suggest that the IHNV NV may support the growth of IHNV through inhibition of the INF system and the amino acid residues of 32EGDL35 responsible for nuclear localization are important for the inhibitory activity of NV.

Ecotoxicological evaluation of the additive butylated hydroxyanisole using a battery with six model systems and eighteen endpoints.

PubMed

Jos, Angeles; Repetto, Guillermo; Ríos, Juan Carlos; del Peso, Ana; Salguero, Manuel; Hazen, María José; Molero, María Luisa; Fernández-Freire, Paloma; Pérez-Martín, Jose Manuel; Labrador, Verónica; Cameán, Ana

2005-01-26

The occurrence and fate of additives in the aquatic environment is an emerging issue in environmental chemistry. This paper describes the ecotoxicological effects of the commonly used additive butylated hydroxyanisole (BHA) using a test battery, comprising of several different organisms and in vitro test systems, representing a proportion of the different trophic levels. The most sensitive system to BHA was the inhibition of bioluminescence in Vibrio fischeri bacteria, which resulted in an acute low observed adverse effect concentration (LOAEC) of 0.28 microM. The next most sensitive system was the immobilization of the cladoceran Daphnia magna followed by: the inhibition of the growth of the unicellular alga Chlorella vulgaris; the endpoints evaluated in Vero (mammalian) cells (total protein content, LDH activity, neutral red uptake and MTT metabolization), mitotic index and root growth inhibition in the terrestrial plant Allium cepa, and finally, the endpoints used on the RTG-2 salmonid fish cell line (neutral red uptake, total protein content, MTS metabolization, lactate dehydrogenase leakage and activity, and glucose-6-phosphate dehydrogenase activity). Morphological alterations in RTG-2 cells were also assessed and these included loss of cells, induction of cellular pleomorphism, hydropic degeneration and induction of apoptosis at high concentrations. The results from this study also indicated that micronuclei were not induced in A.cepa exposed to BHA. The differences in sensitivity for the diverse systems that were used (EC50 ranged from 1.2 to >500 microM) suggest the importance for a test battery approach in the evaluation of the ecological consequences of chemicals. According to the results, the levels of BHA reported in industrial wastewater would elicit adverse effects in the environment. This, coupled with its potential to bioaccumulate, makes BHA a pollutant of concern not only for acute exposures, but also for the long-term.

Design and performance of radioisotope space power systems based on OSC multitube AMTEC converter designs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schock, A.; Noravian, H.; Or, C.

1997-12-31

This paper extends the analytical procedure described in another paper in these proceedings to analyze a variety of compact and light-weight OSC-designed radioisotope-heated generators. Those generators employed General Purpose Heat Source (GPHS) modules and a converter containing sixteen AMTEC cells of OSC`s revised five-tube design with enhanced cell wall reflectivity described in a companion paper in these proceedings. OSC found that the performance of the generator is primarily a function of the thermal insulation between the outside of the generator`s 16 cells and the inside of its wall. After examining a variety of insulation options, it was found that themore » generator`s performance is optimized by employing a hybrid insulation system, in which the space between the cells is filled with fibrous Min-K insulation, and the generator walls are lined with tapered (i.e., graded-length) multifoil insulation. The OSC design results in a very compact generator, with eight AMTEC cells on each end of the heat source stack. The choice of the five-tube cells makes it possible to expand the BASE tube diameter without increasing the cell diameter. This is important because the eight cells mate well with the stacked GPHS modules. The OSC generator design includes a compliant heat source support and preload arrangement, to hold the heat source modules together during launch, and to maintain thermal contact conductance at the generator`s interfaces despite creep relaxation of its housing. The BOM and EOM (up to 15 years) performances of the revised generators were analyzed for two and three GPHS modules, both for fresh fuel and for aged fuel left over from a spare RTG (Radioisotope Thermoelectric Generator) fueled in 1982. The resulting power outputs were compared with JPL`s latest EOM power demand goals for the Pluto Express and Europa Orbiter missions, and with the generic goals of DOE`s Advanced Radioisotope Power System (ARPS) study. The OSC AMTEC designs yielded system efficiencies three to four times as high as present-generation RTGs.« less

Digital control and data acquisition for high-value GTA welding

NASA Astrophysics Data System (ADS)

George, T. G.; Franco-Ferreira, E. A.

Electric power for the Cassini space probe will be provided by radioisotope thermoelectric generators (RTG's) thermally driven by General-Purpose Heat Source (GPHS) modules. Each GPHS module contains four, 150-g, pellets of Pu-238O2, and each of the four pellets is encapsulated within a thin-wall iridium-alloy shell. GTA girth welding of these capsules is performed at Los Alamos National Laboratory (LANL) on an automated, digitally-controlled welding system. Baseline design considerations for system automation and strategies employed to maximize process yield, improve process consistency, and generate required quality assurance information are discussed. Design of the automated girth welding system was driven by a number of factors which militated for precise parametric control and data acquisition. Foremost among these factors was the extraordinary value of the capsule components. In addition, DOE order 5700.6B, which took effect on 23 Sep. 1986, required that all operations adhere to strict levels of process quality assurance. A detailed technical specification for the GPHS welding system was developed on the basis of a joint LANL/Westinghouse Savannah River Company (WSRC) design effort. After a competitive bidding process, Jetline Engineering, Inc., of Irvine, California, was selected as the system manufacturer. During the period over which four identical welding systems were fabricated, very close liason was maintained between the LANL/WSRC technical representatives and the vendor. The level of rapport was outstanding, and the end result was the 1990 delivery of four systems that met or exceeded all specification requirements.

Characterization of Pu-238 heat source granule containment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richardson Ii, P D; Thronas, D L; Romero, J P

2008-01-01

The Milliwatt Radioisotopic Thermoelectric Generator (RTG) provides power for permissive-action links. These nuclear batteries convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of {sup 238}Pu, in the form of {sup 238}PuO{sub 2} granules. The granules are contained in 3 layers of encapsulation. A thin T-111 liner surrounds the {sup 238}PuO{sub 2} granules and protects the second layer (strength member) from exposure to the fuel granules. The T-111 strength member contains the fuel under impact condition. An outer clad of Hastelloy-C protects the T-111 from oxygen embrittlement. Themore » T-111 strength member is considered the critical component in this {sup 238}PuO{sub 2} containment system. Any compromise in the strength member is something that needs to be characterized. Consequently, the T-111 strength member is characterized upon it's decommissioning through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in Secondary Electron mode to reveal possible grain boundary deformation and/or cracking in the region of the strength member weld. Deformation and cracking uncovered by SEM are further characterized by Metallography. Metallography sections are mounted and polished, observed using optical microscopy, then documented in the form of photomicrographs. SEM may further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray Spectroscopy (EDS). This paper describes the characterization of the metallurgical condition of decommissioned RTG heat sources.« less

Thermal Analysis of Step 2 GPHS for Next Generation Radioisotope Power Source Missions

NASA Astrophysics Data System (ADS)

Pantano, David R.; Hill, Dennis H.

2005-02-01

The Step 2 General Purpose Heat Source (GPHS) is a slightly larger and more robust version of the heritage GPHS modules flown on previous Radioisotope Thermoelectric Generator (RTG) missions like Galileo, Ulysses, and Cassini. The Step 2 GPHS is to be used in future small radioisotope power sources, such as the Stirling Radioisotope Generator (SRG110) and the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). New features include an additional central web of Fine Weave Pierced Fabric (FWPF) graphite in the aeroshell between the two Graphite Impact Shells (GIS) to improve accidental reentry and impact survivability and an additional 0.1-inch of thickness to the aeroshell broad faces to improve ablation protection. This paper details the creation of the thermal model using Thermal Desktop and AutoCAD interfaces and provides comparisons of the model to results of previous thermal analysis models of the heritage GPHS. The results of the analysis show an anticipated decrease in total thermal gradient from the aeroshell to the iridium clads compared to the heritage results. In addition, the Step 2 thermal model is investigated under typical SRG110 boundary conditions, with cover gas and gravity environments included where applicable, to provide preliminary guidance for design of the generator. Results show that the temperatures of the components inside the GPHS remain within accepted design limits during all envisioned mission phases.

Disposable Multi-Sensor Unattended Ground Sensor Systems for Detecting Personnel (Systemes de detection multi-capteurs terrestres autonome destines a detecter du personnel)

DTIC Science & Technology

2015-02-01

du personnel » (SET-158 RTG) identifient et accèdent aux technologies potentielles de détection des personnes, qui améliorent la sécurité par...croissante de systèmes de détection à distance, qui soient robustes et de haute performance afin d’assurer la surveillance et l’acquisition des ...les caméras basse et haute résolution. Dans la seconde phase, des approches de phénoménologie des capteurs et de traitement du

Management of Heat and Cold Stress -- Guidance to NATO Medical Personnel (Gestion des contraintes thermiques (chaleur et froid) Conseils aux personnels medicaux de I’OTAN)

DTIC Science & Technology

2013-12-01

de la performance de leurs troupes; b) d’importants écarts scientifiques / de capacités existent en ce qui concerne la susceptibilité, le... La HFM/RTG-187 avait pour but de : a) comparer et évaluer les ressources techniques qui sont actuellement utilisées pour un « système de gestion des ...d’une doctrine et de programmes d’enseignement intégrés pour la gestion des risques thermiques afin de garantir le maintien

The Science Behind 'The Martian' - Staying Warm on Mars

ScienceCinema

Wham, Bob; Ulrich, George

2018-06-21

Set in the not-too-distant future, “The Martian” is the story of an astronaut stranded on Mars who has to rely on his own wit and ingenuity to survive the planet’s hostile conditions. If Mark Watney’s mission were real, Oak Ridge National Laboratory would be playing a vital role in his survival, as it would be the sole source of the Plutonium-238 needed for the RTG, as well as the fuel’s containment material in the form of iridium clad vent sets.

Modular Stirling Radioisotope Generator

NASA Technical Reports Server (NTRS)

Schmitz, Paul C.; Mason, Lee S.; Schifer, Nicholas A.

2015-01-01

High efficiency radioisotope power generators will play an important role in future NASA space exploration missions. Stirling Radioisotope Generators (SRG) have been identified as a candidate generator technology capable of providing mission designers with an efficient, high specific power electrical generator. SRGs high conversion efficiency has the potential to extend the limited Pu-238 supply when compared with current Radioisotope Thermoelectric Generators (RTG). Due to budgetary constraints, the Advanced Stirling Radioisotope Generator (ASRG) was canceled in the fall of 2013. Over the past year a joint study by NASA and DOE called the Nuclear Power Assessment Study (NPAS) recommended that Stirling technologies continue to be explored. During the mission studies of the NPAS, spare SRGs were sometimes required to meet mission power system reliability requirements. This led to an additional mass penalty and increased isotope consumption levied on certain SRG-based missions. In an attempt to remove the spare power system, a new generator architecture is considered which could increase the reliability of a Stirling generator and provide a more fault-tolerant power system. This new generator called the Modular Stirling Radioisotope Generator (MSRG) employs multiple parallel Stirling convertor/controller strings, all of which share the heat from the General Purpose Heat Source (GPHS) modules. For this design, generators utilizing one to eight GPHS modules were analyzed, which provide about 50 to 450 watts DC to the spacecraft, respectively. Four Stirling convertors are arranged around each GPHS module resulting in from 4 to 32 Stirling/controller strings. The convertors are balanced either individually or in pairs, and are radiatively coupled to the GPHS modules. Heat is rejected through the housing/radiator which is similar in construction to the ASRG. Mass and power analysis for these systems indicate that specific power may be slightly lower than the ASRG and similar to the MMRTG. However, the reliability should be significantly increased compared to ASRG.

KSC-2011-6731

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the trailer transporting the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission arrives at the RTG storage facility (RTGF). The MMRTG is returning to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6732

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- At the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida, preparations are under way to offload the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission from the MMRTG trailer. The MMRTG is returning to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6744

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- The multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission is uncovered in the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida. The MMRTG was returned to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

TransFormers for Ensuring Long-Term Operations in Lunar Extreme Environments

NASA Technical Reports Server (NTRS)

Mantovani, J. G.; Stoica, A.; Alkalai, L.; Wilcox, B.; Quadrelli, M.

2016-01-01

"Surviving Extreme Space Environments" (EE) is one of NASA's Space Technology Grand Challenges. Power generation and thermal control are the key survival ingredients that allow a robotic explorer to cope with the EE using resources available to it, for example, by harvesting the local solar energy or by utilizing an onboard radioisotope thermoelectric generator (RTG). TransFormers (TFs) are a new technology concept designed to transform a localized area within a harsh extreme environment into a survivable micro-environment by projecting energy to the precise location where robots or humans operate. For example, TFs placed at a location on the rim of Shackleton Crater, which is illuminated by solar radiation for most of the year, would be able to reflect solar energy onto robots operating in the dark cold crater. TFs utilize a shape transformation mechanism to un-fold from a compact volume to a large reflective surface, and to control how much-and where-the energy is projected, and by adjusting for the changing position of the sun. TFs would enable in-situ resource utilization (ISRU) activities within locations of high interest that would normally be unreachable because of their extreme environment

Viking Lander 1's U.S. Flag on Mars Surface

NASA Technical Reports Server (NTRS)

1976-01-01

The flag of the United States with the rocky Martian surface in the background is seen in this color picture taken on the sixth day of Viking Lander 1 on Mars (July 26). The flag is on the RTG (Radioisotope Thermoelectric Generator) wind screen. Below the flag is the bicentennial logo and the Viking symbol which shows an ancient Viking ship. This Viking symbol was designed by Peter Purol of Baltimore, winner of the Viking logo contest open to high school science students. To the right is the Reference Test Chart used for color balancing of the color images. At the bottom is the GCMS Processor Distribution Assembly with the wind screens unfurled demonstrating that the GCMS cover was deployed properly. The scene in the background is looking almost due west on Mars. The lighter zone at the far horizon is about 3 km (nearly 2 miles) from the Lander. The darker line below this is a hill crest much closer to the Lander (about 200 m or about 650 feet). The picture was taken at local Mars Time of 7:18 A.M., hence the relatively dark sky and the far horizon illuminated by the sun just rising behind the Lander.

KSC-2011-6730

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission, secured inside the MMRTG trailer, makes its way between the Payload Hazardous Servicing Facility (PHSF) and the RTG storage facility. The MMRTG is being moved following a fit check on MSL's Curiosity rover in the PHSF. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

A Deep Space Power System Option Based on Synergistic Power Conversion Technologies

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.

2000-01-01

Deep space science missions have typically used radioisotope thermoelectric generator (RTG) power systems. The RTG power system has proven itself to be a rugged and highly reliable power system over many missions, however the thermal-to-electric conversion technology used was approximately 5% efficient. While the relatively low efficiency has some benefits in terms of system integration, there are compelling reasons why a more efficient conversion system should be pursued. The cost savings alone that are available as a result of the reduced isotope inventory are significant. The Advanced Radioisotope Power System (ARPS) project was established to fulfill this goal. Although it was not part of the ARPS project, Stirling conversion technology is being demonstrated with a low level of funding by both NASA and DOE. A power system with Stirling convertors. although intended for use with an isotope heat source. can be combined with other advanced technologies to provide a novel power system for deep space missions. An inflatable primary concentrator would be used in combination with a refractive secondary concentrator (RSC) as the heat source to power the system. The inflatable technology as a structure has made great progress for a variety of potential applications such as communications reflectors, radiators and solar arrays. The RSC has been pursued for use in solar thermal propulsion applications, and it's unique properties allow some advantageous system trades to be made. The power system proposed would completely eliminate the isotope heat source and could potentially provide power for science missions to planets as distant as Uranus. This paper will present the background and developmental status of the technologies and will then describe the power system being proposed.

A Rover Concept for Exploring the Surface of Titan

NASA Astrophysics Data System (ADS)

Balint, T. S.; Shirley, J. H.; Schriener, T. M.

2005-12-01

Titan is one of the premier targets for future in-situ exploration in the outer solar system, as unique "pre-biotic" organic chemical processes may be presently occurring at its surface. A mission to the surface of Titan is not as technically difficult as one to Europa; Titan's atmosphere allows for aerobraking descents, the radiation environment is not a mission-critical factor, and the organic materials we want to sample should be widely distributed (and easily accessible). The recent Titan landing by the Huygens Probe has focused considerable scientific interest on this remarkable body, and future missions to Titan are under consideration. We evaluated a Titan Rover mission concept that would have the capability to survive on Titan's surface for a period of 3 terrestrial years. This long mission lifetime is enabled by employing a radioisotope power system (RPS). To minimize costs and use as much flight heritage as possible, we began by assuming that system masses, dimensions, and instrumentation would be comparable to those of the Mars Surface Lander (MSL). We found that a rover configuration with a 110 W (electric) power system and four 1.5 m diameter inflatable wheels could potentially enable traverse distances up to ~500 km, depending on science and mission requirements, surface environments, and the capability of the autonomous navigation system employed. Direct to Earth communication would simplify the mission by removing the need for a relay orbiter. We will describe our strawman instrument payload and rover subsystems. Trades between the potentially available RPS systems (RTG, Advanced RTG, TPV, SRG, Advanced Stirling and Brayton RPSs) will be outlined. While many possible approaches exist for Titan in-situ exploration, the Titan rover concept presented here could provide a scientifically interesting and programmatically affordable solution.

Tau depletion prevents progressive blood-brain barrier damage in a mouse model of tauopathy.

PubMed

Blair, Laura J; Frauen, Haley D; Zhang, Bo; Nordhues, Bryce A; Bijan, Sara; Lin, Yen-Chi; Zamudio, Frank; Hernandez, Lidice D; Sabbagh, Jonathan J; Selenica, Maj-Linda B; Dickey, Chad A

2015-01-31

The blood-brain barrier (BBB) is damaged in tauopathies, including progressive supranuclear palsy (PSP) and Alzheimer's disease (AD), which is thought to contribute to pathogenesis later in the disease course. In AD, BBB dysfunction has been associated with amyloid beta (Aß) pathology, but the role of tau in this process is not well characterized. Since increased BBB permeability is found in tauopathies without Aß pathology, like PSP, we suspected that tau accumulation alone could not only be sufficient, but even more important than Aß for BBB damage. Longitudinal evaluation of brain tissue from the tetracycline-regulatable rTg4510 tau transgenic mouse model showed progressive IgG, T cell and red blood cell infiltration. The Evans blue (EB) dye that is excluded from the brain when the BBB is intact also permeated the brains of rTg4510 mice following peripheral administration, indicative of a bonafide BBB defect, but this was only evident later in life. Thus, despite the marked brain atrophy and inflammation that occurs earlier in this model, BBB integrity is maintained. Interestingly, BBB dysfunction emerged at the same time that perivascular tau emerged around major hippocampal blood vessels. However, when tau expression was suppressed using doxycycline, BBB integrity was preserved, suggesting that the BBB can be stabilized in a tauopathic brain by reducing tau levels. For the first time, these data demonstrate that tau alone can initiate breakdown of the BBB, but the BBB is remarkably resilient, maintaining its integrity in the face of marked brain atrophy, neuroinflammation and toxic tau accumulation. Moreover, the BBB can recover integrity when tau levels are reduced. Thus, late stage interventions targeting tau may slow the vascular contributions to cognitive impairment and dementia that occur in tauopathies.

Riverine ecosystem services and the thermoelectric sector: strategic issues facing the Northeastern United States

NASA Astrophysics Data System (ADS)

Miara, A.; Vorosmarty, C. J.; Stewart, R.; Wollheim, W. M.; Rosenzweig, B.

2013-12-01

Major strategic issues facing the global thermoelectric sector include environmental regulation, climate change and increasing electricity demand. We have addressed such issues by modeling thermoelectric generation in the Northeastern United States that is reliant on cooling under five sensitivity tests to evaluate losses/gains in power production, thermal pollution and suitable aquatic habitat, comparing the contemporary baseline (2000-2010) with potential future states. Integral to the analysis, we developed a methodology to quantify river water availability for cooling, which we define as an ecosystem service. Projected climate conditions reduce river water available for efficient power plant operations and the river's capacity to absorb waste heat, causing a loss of regional thermoelectric generation (RTG) (2.5%) in some summers that, compared to the contemporary baseline, is equal to the summertime electricity consumption of 1.3 million Northeastern US homes. Vulnerabilities to warm temperatures and thermal pollution can be alleviated through the use of more efficient natural gas (NG) power plants that have a reduced reliance on cooling water. Conversion of once-through (OT) to cooling tower (CT) systems and the Clean Water Act (CWA) temperature limit regulation, both of which reduce efficiencies at the single plant level, show potential to yield beneficial increases in RTG. This is achieved by obviating the need for large volumes of river water, thereby reducing plant-to-plant interferences through lowering the impact of upstream thermal pollution and preserving a minimum standard of cooling water. The results and methodology framework presented here, which can be extrapolated to other regional assessments with contrasting climates and thermoelectric profiles, can identify opportunities and support decision-making to achieve more efficient energy systems and riverine ecosystem protection.

Riverine ecosystem services and the thermoelectric sector: strategic issues facing the Northeastern United States

NASA Astrophysics Data System (ADS)

Miara, Ariel; Vörösmarty, Charles J.; Stewart, Robert J.; Wollheim, Wilfred M.; Rosenzweig, Bernice

2013-06-01

Major strategic issues facing the global thermoelectric sector include environmental regulation, climate change and increasing electricity demand. We have addressed such issues by modeling thermoelectric generation in the Northeastern United States that is reliant on cooling under five sensitivity tests to evaluate losses/gains in power production, thermal pollution and suitable aquatic habitat, comparing the contemporary baseline (2000-2010) with potential future states. Integral to the analysis, we developed a methodology to quantify river water availability for cooling, which we define as an ecosystem service. Projected climate conditions reduce river water available for efficient power plant operations and the river’s capacity to absorb waste heat, causing a loss of regional thermoelectric generation (RTG) (2.5%) in some summers that, compared to the contemporary baseline, is equal to the summertime electricity consumption of 1.3 million Northeastern US homes. Vulnerabilities to warm temperatures and thermal pollution can be alleviated through the use of more efficient natural gas (NG) power plants that have a reduced reliance on cooling water. Conversion of once-through (OT) to cooling tower (CT) systems and the Clean Water Act (CWA) temperature limit regulation, both of which reduce efficiencies at the single plant level, show potential to yield beneficial increases in RTG. This is achieved by obviating the need for large volumes of river water, thereby reducing plant-to-plant interferences through lowering the impact of upstream thermal pollution and preserving a minimum standard of cooling water. The results and methodology framework presented here, which can be extrapolated to other regional assessments with contrasting climates and thermoelectric profiles, can identify opportunities and support decision-making to achieve more efficient energy systems and riverine ecosystem protection.

Potential civil mission applications for space nuclear power systems

NASA Technical Reports Server (NTRS)

Ambrus, J. H.; Beatty, R. G. G.

1985-01-01

It is pointed out that the energy needs of spacecraft over the last 25 years have been met by photovoltaic arrays with batteries, primary fuel cells, and radioisotope thermoelectric generators (RTG). However, it might be difficult to satisfy energy requirements for the next generation of space missions with the currently used energy sources. Applications studies have emphasized the need for a lighter, cheaper, and more compact high-energy source than the scaling up of current technologies would permit. These requirements could be satisfied by a nuclear reactor power system. The joint NASA/DOD/DOE SP-100 program is to explore and evaluate this option. Critical elements of the technology are also to be developed, taking into account space reactor systems of the 100 kW class. The present paper is concerned with some of the civil mission categories and concepts which are enabled or significantly enhanced by the performance characteristics of a nuclear reactor energy system.

A study of nuclear structure for 244Cm, 241Am, 238Pu, 210Po, 147Pm, 137Cs, 90Sr and 63Ni nuclei used in nuclear battery

NASA Astrophysics Data System (ADS)

Artun, Ozan

2017-07-01

In this paper, we intend to extend the nuclear data of 244Cm, 241Am, 238Pu, 210Po, 147Pm, 137Cs, 90Sr and 63Ni nuclei used in nuclear battery technology, because, these nuclei are quite important for space investigations in radioisotope thermoelectric generator (RTG) and for microelectronic technologies in betavoltaic batteries. Therefore, the nuclear structure properties of nuclei such as separation energies, neutron skin thicknesses, proton, charge and neutron density distributions as a function of radius, the root mean square (rms) proton, charge and neutron radii, binding energies per particle, have been investigated by Hartree-Fock with eight different Skyrme forces. The obtained results have been compared with the experimental data in literature and relativistic mean field theory (RMFT) results.

Mission applications for advanced photovoltaic solar arrays

NASA Technical Reports Server (NTRS)

Stella, Paul M.; West, John L.; Chave, Robert G.; Mcgee, David P.; Yen, Albert S.

1990-01-01

The suitability of the Advanced Photovoltaic Solar Array (APSA) for future space missions was examined by considering the impact on the spacecraft system in general. The lightweight flexible blanket array system was compared to rigid arrays and a radio-isotope thermoelectric generator (RTG) static power source for a wide range of assumed future earth orbiting and interplanetary mission applications. The study approach was to establish assessment criteria and a rating scheme, identify a reference mission set, perform the power system assessment for each mission, and develop conclusions and recommendations to guide future APSA technology development. The authors discuss the three selected power sources, the assessment criteria and rating definitions, and the reference missions. They present the assessment results in a convenient tabular format. It is concluded that the three power sources examined, APSA, conventional solar arrays, and RTGs, can be considered to complement each other. Each power technology has its own range of preferred applications.

Shuttle data book: SRM fragment velocity model. Presented to the SRB Fragment Model Review Panel

NASA Technical Reports Server (NTRS)

1989-01-01

This study was undertaken to determine the velocity of fragments generated by the range safety destruction (RSD) or random failure of a Space Transportation System (STS) Solid Rocket Motor (SRM). The specific requirement was to provide a fragment model for use in those Galileo and Ulysses RTG safety analyses concerned with possible fragment impact on the spacecraft radioisotope thermoelectric generators (RTGS). Good agreement was obtained between predictions and observations for fragment velocity, velocity distributions, azimuths, and rotation rates. Based on this agreement with the entire data base, the model was used to predict the probable fragment environments which would occur in the event of an STS-SRM RSD or randon failure at 10, 74, 84 and 110 seconds. The results of these predictions are the basis of the fragment environments presented in the Shuttle Data Book (NSTS-08116). The information presented here is in viewgraph form.

KSC-97PC1068

NASA Image and Video Library

1997-07-18

Jet Propulsion Laboratory (JPL) workers Dan Maynard and John Shuping prepare to install a radioisotope thermoelectric generator (RTG) on the Cassini spacecraft in the Payload Hazardous Servicing Facility (PHSF). The three RTGs which will provide electrical power to Cassini on its mission to the Saturnian system are undergoing mechanical and electrical verification testing in the PHSF. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate far from the Sun where solar power systems are not feasible. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL

Power Supplies for Space Systems Quality Assurance by Sandia Laboratories

DOE R&D Accomplishments Database

Hannigan, R. L.; Harnar, R. R.

1976-07-01

The Sandia Laboratories` participation in Quality Assurance programs for Radioisotopic Thermoelectric Generators which have been used in space systems over the past 10 years is summarized. Basic elements of this QA program are briefly described and recognition of assistance from other Sandia organizations is included. Descriptions of the various systems for which Sandia has had the QA responsibility are presented, including SNAP 19 (Nimbus, Pioneer, Viking), SNAP 27 (Apollo), Transit, Multi Hundred Watt (LES 8/9 and MJS), and a new program, High Performance Generator Mod 3. The outlook for Sandia participation in RTG programs for the next several years is noted.

Performance testing of thermoelectric generators including Voyager and LES 8/9 flight results

NASA Technical Reports Server (NTRS)

Garvey, L.; Stapfer, G.

1979-01-01

Several thermoelectric generators ranging in output power from 0.5 to 155 W have been completed or are undergoing testing at JPL. These generators represent a wide range of technologies, using Bi2Te3, PbTe and SiGe thermoelectric materials. Several of these generators are of a developmental type, such as HPG S/N2, and others are representative of Transit and Multi-Hundred Watt (MHW) Technology. Representative flight performance data of LES 8/9 and Voyager RTG's are presented and compared with the DEGRA computer program based on the data observed from tests of SiGe couples, modules and MHW generators.

KSC-05pd2542

NASA Image and Video Library

2005-12-01

KENNEDY SPACE CENTER, FLA. - Inside NASA Kennedy Space Center’s Payload Hazardous Servicing Facility, workers push the newly arrived third stage, or upper stage for the New Horizons spacecraft, into position for uncovering. The third stage is a Boeing STAR 48 solid-propellant kick motor. The Atlas V is the launch vehicle for NASA’s New Horizons spacecraft, scheduled to launch from Cape Canaveral Air Force Station, Fla., during a 35-day window that opens Jan. 11 and fly through the Pluto system as early as summer 2015. New Horizons will be powered by a single radioisotope thermoelectric generator (RTG), provided by the Department of Energy, which will be installed shortly before launch.

KSC-05pd2539

NASA Image and Video Library

2005-12-01

KENNEDY SPACE CENTER, FLA. - Before dawn, the third stage, or upper stage for the New Horizons spacecraft, arrives at NASA Kennedy Space Center’s Payload Hazardous Servicing Facility. The third stage is a Boeing STAR 48 solid-propellant kick motor. The Atlas V is the launch vehicle for NASA’s New Horizons spacecraft, scheduled to launch from Cape Canaveral Air Force Station, Fla., during a 35-day window that opens Jan. 11 and fly through the Pluto system as early as summer 2015. New Horizons will be powered by a single radioisotope thermoelectric generator (RTG), provided by the Department of Energy, which will be installed shortly before launch.

KSC-05pd2541

NASA Image and Video Library

2005-12-01

KENNEDY SPACE CENTER, FLA. - The third stage, or upper stage for the New Horizons spacecraft, is moved toward the open door of NASA Kennedy Space Center’s Payload Hazardous Servicing Facility. The third stage is a Boeing STAR 48 solid-propellant kick motor. The Atlas V is the launch vehicle for NASA’s New Horizons spacecraft, scheduled to launch from Cape Canaveral Air Force Station, Fla., during a 35-day window that opens Jan. 11 and fly through the Pluto system as early as summer 2015. New Horizons will be powered by a single radioisotope thermoelectric generator (RTG), provided by the Department of Energy, which will be installed shortly before launch.

KSC-05pd2540

NASA Image and Video Library

2005-12-01

KENNEDY SPACE CENTER, FLA. - The third stage, or upper stage for the New Horizons spacecraft, is moved toward the open door of NASA Kennedy Space Center’s Payload Hazardous Servicing Facility. The third stage is a Boeing STAR 48 solid-propellant kick motor. The Atlas V is the launch vehicle for NASA’s New Horizons spacecraft, scheduled to launch from Cape Canaveral Air Force Station, Fla., during a 35-day window that opens Jan. 11 and fly through the Pluto system as early as summer 2015. New Horizons will be powered by a single radioisotope thermoelectric generator (RTG), provided by the Department of Energy, which will be installed shortly before launch.

KSC-05pd2543

NASA Image and Video Library

2005-12-01

KENNEDY SPACE CENTER, FLA. - Inside NASA Kennedy Space Center’s Payload Hazardous Servicing Facility, workers remove the protective cover from around the newly arrived third stage, or upper stage for the New Horizons spacecraft. The third stage is a Boeing STAR 48 solid-propellant kick motor. The Atlas V is the launch vehicle for NASA’s New Horizons spacecraft, scheduled to launch from Cape Canaveral Air Force Station, Fla., during a 35-day window that opens Jan. 11 and fly through the Pluto system as early as summer 2015. New Horizons will be powered by a single radioisotope thermoelectric generator (RTG), provided by the Department of Energy, which will be installed shortly before launch.

Space Science

NASA Image and Video Library

1997-07-18

Jet Propulsion Research Lab (JPL) workers use a borescope to verify the pressure relief device bellow's integrity on a radioisotope thermoelectric generator (RTG) that has been installed on the Cassini spacecraft in the Payload Hazardous Servicing Facility. The activity is part of the mechanical and electrical verification testing of RTGs during prelaunch processing. RTGs use heat from the natural decay of plutonium to generate electrical power. The three RTGs on Cassini will enable the spacecraft to operate far from the Sun where solar power systems are not feasible. They will provide electrical power to Cassini on it seven year trip to the Saturnian system and during its four year mission at Saturn.

Antimicrobial and host cell-directed activities of Gly/Ser-rich peptides from salmonid cathelicidins.

PubMed

D'Este, Francesca; Benincasa, Monica; Cannone, Giuseppe; Furlan, Michela; Scarsini, Michele; Volpatti, Donatella; Gennaro, Renato; Tossi, Alessandro; Skerlavaj, Barbara; Scocchi, Marco

2016-12-01

Cathelicidins, a major family of vertebrate antimicrobial peptides (AMPs), have a recognized role in the first line of defense against infections. They have been identified in several salmonid species, where the putative mature peptides are unusually long and rich in serine and glycine residues, often arranged in short multiple repeats (RLGGGS/RPGGGS) intercalated by hydrophobic motifs. Fragments of 24-40 residues, spanning specific motifs and conserved sequences in grayling or brown, rainbow and brook trout, were chemically synthesized and examined for antimicrobial activity against relevant Gram-positive and Gram-negative salmonid pathogens, as well as laboratory reference strains. They were not active in complete medium, but showed varying potency and activity spectra in diluted media. Bacterial membrane permeabilization also occurred only under these conditions and was indicated by rapid propidium iodide uptake in peptide-treated bacteria. However, circular dichroism analyses indicated that they did not significantly adopt ordered conformations in membrane-like environments. The peptides were not hemolytic or cytotoxic to trout cells, including freshly purified head kidney leukocytes (HKL) and the fibroblastic RTG-2 cell line. Notably, when exposed to them, HKL showed increased metabolic activity, while a growth-promoting effect was observed on RTG-2 cells, suggesting a functional interaction of salmonid cathelicidins with host cells similar to that shown by mammalian ones. The three most active peptides produced a dose-dependent increase in phagocytic uptake by HKL simultaneously stimulated with bacterial particles. The peptide STF(1-37), selected for further analyses, also enhanced phagocytic uptake in the presence of autologous serum, and increased intracellular killing of live E. coli. Furthermore, when tested on HKL in combination with the immunostimulant β-glucan, it synergistically potentiated both phagocytic uptake and the respiratory burst response, activities that play a key role in fish immunity. Collectively, these data point to a role of salmonid cathelicidins as modulators of fish microbicidal mechanisms beyond a salt-sensitive antimicrobial activity, and encourage further studies also in view of potential applications in aquaculture. Copyright © 2016 Elsevier Ltd. All rights reserved.

KSC-2011-6737

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- Department of Energy workers position mobile plexiglass radiation shields around the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission upon its arrival in the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida. The shields are designed to minimize the employees' radiation exposure. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is returning to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

Assessment of the disinfection capacity and eco-toxicological impact of atmospheric cold plasma for treatment of food industry effluents.

PubMed

Patange, Apurva; Boehm, Daniela; Giltrap, Michelle; Lu, Peng; Cullen, P J; Bourke, Paula

2018-08-01

Generation of wastewater is one of the main environmental sustainability issues across food sector industries. The constituents of food process effluents are often complex and require high energy and processing for regulatory compliance. Wastewater streams are the subject of microbiological and chemical criteria, and can have a significant eco-toxicological impact on the aquatic life. Thus, innovative treatment approaches are required to mitigate environmental impact in an energy efficient manner. Here, dielectric barrier discharge atmospheric cold plasma (ACP) was evaluated for control of key microbial indicators encountered in food industry effluent. This study also investigated the eco-toxicological impact of cold plasma treatment of the effluents using a range of aquatic bioassays. Continuous ACP treatment was applied to synthetic dairy and meat effluents. Microbial inactivation showed treatment time dependence with significant reduction in microbial populations within 120 s, and to undetectable levels after 300 s. Post treatment retention time emerged as critical control parameter which promoted ACP bacterial inactivation efficiency. Moreover, ACP treatment for 20 min achieved significant reduction (≥2 Log 10 ) in Bacillus megaterium endospores in wastewater effluent. Acute aquatic toxicity was assessed using two fish cell lines (PLHC-1 and RTG-2) and a crustacean model (Daphnia magna). Untreated effluents were toxic to the aquatic models, however, plasma treatment limited the toxic effects. Differing sensitivities were observed to ACP treated effluents across the different test bio-assays in the following order: PLHC-1 > RTG-2 ≥ D. magna; with greater sensitivity retained to plasma treated meat effluent than dairy effluent. The toxic effects were dependent on concentration and treatment time of the ACP treated effluent; with 30% cytotoxicity in D. magna and fish cells observed after 24 h of exposure to ACP treated effluent for concentrations up to 5%. The findings suggest the need to employ wider variety of aquatic organisms for better understanding and complete toxicity evaluation of long-term effects. The study demonstrates the potential to tailor ACP system parameters to control pertinent microbial targets (mono/poly-microbial, vegetative or spore form) found in complex and nutritious wastewater effluents whilst maintaining a safe eco-toxicity profile for aquatic species. Copyright © 2018 Elsevier B.V. All rights reserved.

KSC-2011-6745

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- The multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission is position behind mobile plexiglass radiation shields in the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida. The MMRTG was returned to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The generator will remain in the RTGF until is moved to the pad for integration on the rover. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6651

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- The multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission, enclosed in a shipping cask, rolls into the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6658

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, a crane lifts the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission from its transportation pallet. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

Base flow investigation of the Apollo AS-202 Command Module

NASA Astrophysics Data System (ADS)

Walpot, Louis M. G.; Wright, Michael J.; Noeding, Peter; Schrijer, Ferry

2012-01-01

A major contributor to the overall vehicle mass of re-entry vehicles is the afterbody thermal protection system. This is due to the large acreage (equal or bigger than that of the forebody) to be protected. The present predictive capabilities for base flows are comparatively lower than those for windward flowfields and offer therefore a substantial potential for improving the design of future re-entry vehicles. To that end, it is essential to address the accuracy of high fidelity CFD tools exercised in the US and EU, which motivates a thorough investigation of the present status of hypersonic flight afterbody heating. This paper addresses the predictive capabilities of afterbody flow fields of re-entry vehicles investigated in the frame of the NATO/RTO-RTG-043 task group. First, the verification of base flow topologies on the basis of available wind-tunnel results performed under controlled supersonic conditions (i.e. cold flows devoid of reactive effects) is performed. Such tests address the detailed characterization of the base flow with particular emphasis on separation/reattachment and their relation to Mach number effects. The tests have been performed on an Apollo-like re-entry capsule configuration. Second, the tools validated in the frame of the previous effort are exercised and appraised against flight-test data collected during the Apollo AS-202 re-entry.

KSC-2011-6647

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- The multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission, enclosed in a shipping cask, is seen through the open door of the MMRTG trailer that delivered it to the RTG storage facility at NASA's Kennedy Space Center in Florida. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6650

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- Workers use a forklift to transport the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission to the door of the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6648

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- Workers use a forklift to offload the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission from the MMRTG trailer that delivered it to the RTG storage facility at NASA's Kennedy Space Center in Florida. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6653

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, measurements are taken to determine the level of radioactivity emitted from the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission, enclosed in a shipping cask in the background. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6662

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, Department of Energy contractor employees remove the external and internal protective layers of the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6663

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, the external and internal protective layers of the shipping cask are lifted from around the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6659

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the RTG storage facility at NASA's Kennedy Space Center in Florida, the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission is lowered to the floor of the high bay in preparation for lifting the cask from around the MMRTG. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6649

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- Workers use a forklift to offload the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission from the MMRTG trailer that delivered it to the RTG storage facility at NASA's Kennedy Space Center in Florida. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6660

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission is lifted from around the MMRTG using guide rods installed on the support base. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

Unbundling of electric power and energy services

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keith, D.M.; Lewis, B.R.

1996-12-31

The world-wide movement to restructure the electric and power and energy industry is now well underway in the United States. The most recent thrust came this year, with the Federal Energy Regulatory Commission`s (FERC`s) issuance on April 24th of new regulations designed to open the interconnected transmission grid to all qualified wholesale users. Other movements have been in the many forms of earlier statutes and regulations promulgated in 1978 to make more efficient use of fuels burned; utility diversification efforts; utility creation of affiliate and subsidiary organizations and operations; introduction into the market of private non-utility power developers; utilities obtainingmore » clearance from the Securities and Exchange Commission (SEC) to venture in international markets; massive mergers and acquisitions; bankruptcies; the entry into the market of nonutility power marketers and brokers, including entities from the gas and securities industries not previously involved in the electric power and energy industry; additional congressional consideration of outright repeal of Holding Company legislation dating back to 1935; some states entering into an era of abandoning the control past in favor of complete re-regulation of the industry on the basis of performance; the coming of Independent System Operators (ISO`s), Regional Transmission Groups (RTG`s), and the possible coming of Capacity Reservation Tariffs (CRT`s), to name a few.« less

KSC-97PC1066

NASA Image and Video Library

1997-07-18

Jet Propulsion Laboratory (JPL) engineers examine the interface surface on the Cassini spacecraft prior to installation of the third radioisotope thermoelectric generator (RTG). The other two RTGs, at left, already are installed on Cassini. The three RTGs will be used to power Cassini on its mission to the Saturnian system. They are undergoing mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate far from the Sun where solar power systems are not feasible. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL

KSC-97PC1090

NASA Image and Video Library

1997-07-19

Workers in the Payload Hazardous Servicing Facility remove the storage collar from a radioisotope thermoelectric generator (RTG) in preparation for installation on the Cassini spacecraft. Cassini will be outfitted with three RTGs. The power units are undergoing mechanical and electrical verification tests in the PHSF. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle

CTEF 2.0 - Assessment and Improvement of Command Team Effectiveness: Verification of Model and Instrument (CTEF 2.0 - Diagnostic et Amelioration de l’Efficacite d’un Team de Commandement: Verification du Modele et de l’Instrument)

DTIC Science & Technology

2010-09-01

what level of detail is needed to build their teams, and they can add more detailed items from the model in order to tap deeper in the performance of...of a project on ‘Command Team Effectiveness’ by Task Group 127 for the RTO Human Factors and Medicine Panel (RTG HFM-127). Published...vérification du modèle et de l’instrument) This Technical Report documents the findings of a project on ‘Command Team Effectiveness’ by Task Group

Emitted radiation characteristics of plutonium dioxide radioisotope thermoelectric generators

NASA Technical Reports Server (NTRS)

Gingo, P. J.; Steyn, J. J.

1971-01-01

The nuclear and emitted radiation characteristics of the radioisotope elements and impurities in commercial grade plutonium dioxide are presented in detail. The development of the methods of analysis are presented. Radioisotope thermoelectric generators (RTG) of 1575, 3468 and 5679 thermal watts are characterized with respect to neutron and gamma photon source strength as well as spatial and number flux distribution. The results are presented as a function of detector position and light element contamination concentration for fuel age ranging from 'fresh' to 18 years. The data may be used to obtain results for given O-18 and Pu-236 concentrations. The neutron and gamma photon flux and dose calculations compare favorably with reported experimental values for SNAP-27.

High temperature material interactions of thermoelectric systems using silicon germanium.

NASA Technical Reports Server (NTRS)

Stapfer, G.; Truscello, V. C.

1973-01-01

The efficient use of silicon germanium thermoelectric material for radioisotope thermoelectric generators (RTG) is achieved by operation at relatively high temperatures. The insulation technique which is most appropriate for this application uses multiple layers of molybdenum foil and astroquartz. Even so, the long term operation of these materials at elevated temperatures can cause material interaction to occur within the system. To investigate these material interactions, the Jet Propulsion Laboratory is currently testing a number of thermoelectric modules which use four silicon germanium thermoelectric couples in conjunction with the multifoil thermal insulation. The paper discusses the results of the ongoing four-couple module test program and correlates test results with those of a basic material test program.

238PuO 2 Fuel and Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayo, Douglas R.; Rawool-Sullivan, Mohini; Garner, Scott Edward

2016-06-01

238Pu is an ideal material for use as a heat source with its half-life of 87.7 years and copious particle emissions. 238Pu radioisotope thermoelectric generators (RTGs) have found use for pacemakers, Apollo Space missions, Mars rovers, and Voyager spacecraft. In evaluating the dose to personnel and components near a 238Pu-based RTG, a number of additional nuclides and their daughter products must be considered to get an accurate estimate for γ-dose, and the amount of 17O and 18O for the neutron-dose must be considered. This paper looks at the contributing nuclides and their daughter products that add the most to themore » dose rates.« less

U.S. Space Radioisotope Power Systems and Applications: Past, Present and Future

NASA Technical Reports Server (NTRS)

Cataldo, Robert L.; Bennett, Gary L.

2011-01-01

Radioisotope power systems (RPS) have been essential to the U.S. exploration of outer space. RPS have two primary uses: electrical power and thermal power. To provide electrical power, the RPS uses the heat produced by the natural decay of a radioisotope (e.g., plutonium-238 in U.S. RPS) to drive a converter (e.g., thermoelectric elements or Stirling linear alternator). As a thermal power source the heat is conducted to whatever component on the spacecraft needs to be kept warm; this heat can be produced by a radioisotope heater unit (RHU) or by using the excess heat of a radioisotope thermoelectric generator (RTG). As of 2010, the U.S. has launched 41 RTGs on 26 space systems. These space systems have ranged from navigational satellites to challenging outer planet missions such as Pioneer 10/11, Voyager 1/2, Galileo, Ulysses, Cassini and the New Horizons mission to Pluto. In the fall of 2011, NASA plans to launch the Mars Science Laboratory (MSL) that will employ the new Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) as the principal power source. Hundreds of radioisotope heater units (RHUs) have been launched to provide warmth to Apollo 11, used to provide heating of critical components in a seismic experiment package, Pioneer 10/11, Voyager 1/2, Galileo, Cassini, Mars Pathfinder, MER rovers, etc. to provide temperature control to critical spacecraft electronics and other mechanical devices such as propulsion system propellant valves. A radioisotope (electrical) power source or system (RPS) consists of three basic elements: (1) the radioisotope heat source that provides the thermal power, (2) the converter that transforms the thermal power into electrical power and (3) the heat rejection radiator. Figure 1 illustrates the basic features of an RPS. The idea of a radioisotope power source follows closely after the early investigations of radioactivity by researchers such as Henri Becquerel (1852-1908), Marie Curie (1867-1935), Pierre Curie (1859-1906) and R. J. Strut. Almost 100 years ago, in 1913, English physicist H. G. J. Moseley (1887-1915) constructed the first nuclear battery using a vacuum flask and 20 mCi of radium (Corliss and Harvey, 1964, Proceedings of the Royal Society, 1913). After World War II, serious interest in radioisotope power systems in the U.S. was sparked by studies of space satellites such as North American Aviation s 1947 report on nuclear space power and the RAND Corporation s 1949 report on radioisotope power. (Greenfield, 1947, Gendler and Kock, 1949). Radioisotopes were also considered in early studies of nuclear-powered aircraft (Corliss and Harvey, 1964). In 1951, the U.S. Atomic Energy Commission (AEC) signed several contracts to study a 1-kWe space power plant using reactors or radioisotopes. Several of these studies, which were completed in 1952, recommended the use of RPS. (Corliss and Harvey, 1964). In 1954, the RAND Corporation issued the summary report of the Project Feedback military satellite study in which radioisotope power was considered (Lipp and Salter, 1954, RAND). Paralleling these studies, in 1954, K. C. Jordan and J. H. Birden of the AEC s Mound Laboratory conceived and built the first RTG using chromel-constantan thermocouples and a polonium-210 (210Po or Po-210) radioisotope heat source (see Figure 2). While the power produced (1.8 mWe) was low by today s standards, this first RTG showed the feasibility of RPS. A second thermal battery was built with more Po-210, producing 9.4 mWe. Jordan and Birden concluded that the Po-210 thermal battery would have about ten times the energy of ordinary dry cells of the same mass (Jordan and Birden, 1954). The heat source consisted of a 1-cm-diameter sphere of 57 Ci (1.8 Wt) of Po-210 inside a capsule of nickel-coated cold-rolled steel all inside a container of Lucite. The thermocouples were silver-soldered chromel-constantan. The thermal battery produced 1.8 mWe.

Non-Cooled Power System for Venus Lander

NASA Technical Reports Server (NTRS)

Salazar, Denise; Landis, Geoffrey A.; Colozza, Anthony J.

2014-01-01

The Planetary Science Decadal Survey of 2013-2022 stated that the exploration of Venus is of significant interest. Studying the seismic activity of the planet is of particular importance because the findings can be compared to the seismic activity of Earth. Further, the geological and atmospheric properties of Venus will shed light into the past and future of Earth. This paper presents a radioisotope power system (RPS) design for a small low-power Venus lander. The feasibility of the new power system is then compared to that of primary batteries. A requirement for the power source system is to avoid moving parts in order to not interfere with the primary objective of the mission - to collect data about the seismic activity of Venus using a seismometer. The target mission duration of the lander is 117 days, a significant leap from Venera 13, the longest-lived lander on the surface of Venus, which survived for 2 hours. One major assumption for this mission design is that the power source system will not provide cooling to the other components of the lander. This assumption is based on high-temperature electronics technology that will enable the electronics and components of the lander to operate at Venus surface temperature. For the proposed RPS, a customized General Purpose Heat Source Radioisotope Thermoelectric Generator (GPHSRTG) is designed and analyzed. The GPHS-RTG is chosen primarily because it has no moving parts and it is capable of operating for long duration missions on the order of years. This power system is modeled as a spherical structure for a fundamental thermal analysis. The total mass and electrical output of the system are calculated to be 24 kilograms and 26 Watts, respectively. An alternative design for a battery-based power system uses Sodium Sulfur batteries. To deliver a similar electrical output for 117 days, the battery mass is calculated to be 234 kilograms. Reducing mission duration or power required will reduce the required battery mass. Finally, the advantages and disadvantages of both power systems with regard to science return, risk, and cost are briefly compared. The design of the radioisotope power system is considerably riskier because it is novel and would require additional years of further refinement, manufacturing, safety analysis, and testing that the primary batteries do not need. However, the lifetime of the radioisotope power system makes its science return more promising.

Effect of turpentine oil on C-reactive protein (CRP) production in rainbow trout (Oncorhynchus mykiss).

PubMed

Liu, Youchang; Iwasaki, Tadashi; Watarai, Shinobu; Kodama, Hiroshi

2004-09-01

The effect of turpentine oil on C-reactive protein (CRP) production was studied in rainbow trout (Oncorhynchus mykiss). Serum CRP concentration was estimated by sandwich enzyme-linked immunosorbent assay using anti-rainbow trout CRP monoclonal antibody (mAb) AC4 and polyclonal antibody. Intracellular CRP was demonstrated by flow cytometry using anti-trout CRP mAb. Hepatocytes, head kidney macrophages, spleen lymphocytes and peripheral blood lymphocytes showed reaction against AC4, but RTG-2 fibroblastic line cells, derived from rainbow trout gonad did not. This is the first report on the detection of intracellular CRP in fish. CRP levels decreased significantly 1 day after intramuscular injection of turpentine oil and remained low for 14 days. Significant decreases in the expression of CRP in hepatocytes, head kidney macrophages and spleen lymphocytes after injection of turpentine oil were found. The reduction of serum CRP concentration after turpentine oil injection may be attributed to decreases in intracellular CRP synthesis.

Cassini's RTGs undergo mechanical and electrical verification testing in the PHSF

NASA Technical Reports Server (NTRS)

1997-01-01

Jet Propulsion Laboratory (JPL) engineers examine the interface surface on the Cassini spacecraft prior to installation of the third radioisotope thermoelectric generator (RTG). The other two RTGs, at left, already are installed on Cassini. The three RTGs will be used to power Cassini on its mission to the Saturnian system. They are undergoing mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate far from the Sun where solar power systems are not feasible. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL.

KSC-97PC1067

NASA Image and Video Library

1997-07-18

This radioisotope thermoelectric generator (RTG), at center, will undergo mechanical and electrical verification testing now that it has been installed on the Cassini spacecraft in the Payload Hazardous Servicing Facility. A handling fixture, at far left, is still attached. Three RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate far from the Sun where solar power systems are not feasible. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by the Jet Propulsion Laboratory

Modeling of 1.5 μm range gated imaging for small surface vessel identification

NASA Astrophysics Data System (ADS)

Espinola, Richard L.; Steinvall, Ove; Elmquist, Magnus; Karlsson, Kjell

2010-10-01

Within the framework of the NATO group (NATO SET-132/RTG-72) on imaging ladars, a test was performed to collect simultaneous multi-mode LADAR signatures of maritime objects entering and leaving San Diego Harbor. Beside ladars, passive sensors were also employed during the test which occurred during April 2009 from Point Loma and the harbor in San Diego. This paper will report on 1.5 μm gated imaging on a number of small civilian surface vessels with the aim to present human perception experimental results and comparisons with sensor performance models developed by US Army RDECOM CERDEC NVESD. We use controlled human perception tests to measure target identification performance and compare the experimental results with model predictions.

Cassini's RTGs undergo mechanical and electrical verification tests in the PHSF

NASA Technical Reports Server (NTRS)

1997-01-01

Workers in the Payload Hazardous Servicing Facility remove the storage collar from a radioisotope thermoelectric generator (RTG) in preparation for installation on the Cassini spacecraft. Cassini will be outfitted with three RTGs. The power units are undergoing mechanical and electrical verification tests in the PHSF. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle.

Inadvertent Earth Reentry Breakup Analysis for the New Horizons Mission

NASA Technical Reports Server (NTRS)

Ling, Lisa M.; Salama, Ahmed; Ivanov, Mark; McRonald, Angus

2007-01-01

The New Horizons (NH) spacecraft was launched in January 2006 aboard an Atlas V launch vehicle, in a mission to explore Pluto, its moons, and other bodies in the Kuiper Belt. The NH spacecraft is powered by a Radioisotope Thermoelectric Generator (RTG) which encases multiple General Purpose Heat Source (GPHS) modules. Thus, a pre-launch vehicle breakup analysis for an inadvertent atmospheric reentry in the event of a launch failure was required to assess aerospace nuclear safety and for launch contingency planning. This paper addresses potential accidental Earth reentries analyzed at the Jet Propulsion Laboratory (JPL) which may arise during the ascent to parking orbit, resulting in a suborbital reentry, as well as a departure from parking orbit, resulting in an orbital reentry.

Perspectives of The Interagency Nuclear Safety Review Panel (INSRP) on future nuclear powered space missions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, L.B.; Pyatt, D.W.; Sholtis, J.A.

1993-01-10

The Interagency Nuclear Safety Review Panel (INSRP) has provided reviews of all nuclear powered spacecraft launched by the United States. The two most recent launches were Ulysses in 1990 and Galileo in 1989. One reactor was launched in 1965 (SNAP-10A). All other U.S. space missions have utilized radioisotopic thermoelectric generators (RTGs). There are several missions in the next few years that are to be nuclear powered, including one that would utilize the Topaz II reactor purchased from Russia. INSRP must realign itself to perform parallel safety assessments of a reactor powered space mission, which has not been done in aboutmore » thirty years, and RTG powered missions.« less

KSC-2011-6727

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a forklift lifts the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission into the MMRTG trailer. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is being moved to the RTG storage facility following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6667

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission is enclosed in a protective mesh container, known as the "gorilla cage," for transport to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6722

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- In the airlock of the Payload Hazardous Servicing Facility (PHSF) at NASA's Kennedy Space Center in Florida, t he multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission awaits transport to the RTG storage facility. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG was in the PHSF for a fit check on MSL's Curiosity rover. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6726

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- A forklift transfers the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission from the airlock of the Payload Hazardous Servicing Facility (PHSF) at NASA's Kennedy Space Center in Florida to the MMRTG trailer. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is being moved to the RTG storage facility following a fit check on MSL's Curiosity rover in the PHSF. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6735

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- A forklift moves the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission into the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is returning to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6652

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- Workers reconnect the coolant hoses to the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission upon its arrival in the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida. Coolant flows through the hoses to dissipate any excess heat generated by the MMRTG. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6734

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- A forklift moves the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission from the MMRTG trailer to the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is returning to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6725

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- A forklift carrying the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission backs away from the airlock of the Payload Hazardous Servicing Facility (PHSF) at NASA's Kennedy Space Center in Florida. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is being moved to the RTG storage facility following a fit check on MSL's Curiosity rover in the PHSF. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6736

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- Department of Energy workers park the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission in the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is returning to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6743

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida, the mesh container enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission is lifted from around the MMRTG. The container, known as the "gorilla cage," protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. The cage is being removed following the return of the MMRTG to the RTGF from a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6666

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the RTG storage facility at NASA's Kennedy Space Center in Florida, the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission, with guide rods still installed on its support base, has been uncovered on the high bay floor. The MMRTG no longer needs supplemental cooling since any excess heat generated can dissipate into the air in the high bay. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6721

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- A forklift approaches the airlock of the Payload Hazardous Servicing Facility (PHSF) at NASA's Kennedy Space Center in Florida where the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission awaits transport to the RTG storage facility. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG was in the PHSF for a fit check on MSL's Curiosity rover. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6723

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- A forklift moves into position to lift the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission from the floor of the Payload Hazardous Servicing Facility (PHSF) airlock at NASA's Kennedy Space Center in Florida. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is being transported to the RTG storage facility following a fit check on MSL's Curiosity rover in the PHSF. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6733

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- The multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission is lifted from the MMRTG trailer at the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is returning to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6717

NASA Image and Video Library

2011-07-13

CAPE CANAVERAL, Fla. -- In the airlock of the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, Department of Energy employees prepare the support base of the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission for installation of the mesh container, known as the "gorilla cage." The cage, in the background at right, protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. Transport of the MMRTG to the RTG storage facility follows the completion of the MMRTG fit check on the Curiosity rover. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Kim Shiflett

KSC-2011-6665

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, the external and internal protective layers of the shipping cask are lifted away from the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission. The MMRTG no longer needs supplemental cooling since any excess heat generated can dissipate into the air in the high bay. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6646

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- The multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission, enclosed in a shipping cask in the MMRTG trailer, arrives at the RTG storage facility at NASA's Kennedy Space Center in Florida. During transport, coolant flows through hoses connected to the cask to dissipate any excess heat generated by the MMRTG. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6724

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- A forklift moves into position to lift the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission from the floor of the Payload Hazardous Servicing Facility (PHSF) airlock at NASA's Kennedy Space Center in Florida. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is being moved to the RTG storage facility following a fit check on MSL's Curiosity rover in the PHSF. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6728

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, a forklift lifts the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission into the MMRTG trailer. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is being moved to the RTG storage facility following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6675

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Outside the RTG storage facility at NASA's Kennedy Space Center in Florida, the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission, enclosed in the protective mesh container known as the "gorilla cage," is strapped down inside the MMRTG trailer for transport to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6654

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, Innovative Health Applications employee Mike McPherson measures the level of radioactivity emitted from the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission, enclosed in a shipping cask at right. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6661

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, Innovative Health Applications employee David Lake measures the level of radioactivity emitted from the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission as the external protective layer of the shipping cask is removed. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6656

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, Department of Energy contractor employees attach cables to the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission during preparations to lift it from its transportation pallet. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6655

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, preparations are under way to attach the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission to the cables that will lift it from its transportation pallet. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6657

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, a Department of Energy contractor employee attaches a crane to the shipping cask enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission during preparations to lift it from its transportation pallet. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6729

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, preparations are under way to secure the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission in the MMRTG trailer. The MMRTG is enclosed in a mesh container, known as the "gorilla cage," which protects it during transport and allows any excess heat generated to dissipate into the air. The MMRTG is being moved to the RTG storage facility following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

High efficiency radioisotope thermophotovoltaic prototype generator

NASA Technical Reports Server (NTRS)

Avery, James E.; Samaras, John E.; Fraas, Lewis M.; Ewell, Richard

1995-01-01

A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, we present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. We compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. We find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. We propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter. The Jet Propulsion Laboratory will design and build the thermal cavity, and JX Crystals will fabricate the gallium antimonide cells, dielectric filters, and resultant receiver panels. With 250 Watts of heat input, we expect this prototype to produce over 300 Watts of electrical energy output for a system energy conversion efficiency of over 12%. This low risk, near term design provides advances relative to present radioisotope thermophotovoltaic generators and has the additional advantage of allowing component and system development and testing to begin immediately. Improved cells and filters can easily be incorporated in this baseline system if they should become available in the future.

High efficiency radioisotope thermophotovoltaic prototype generator

NASA Astrophysics Data System (ADS)

Avery, James E.; Samaras, John E.; Fraas, Lewis M.; Ewell, Richard

1995-10-01

A radioisotope thermophotovoltaic generator space power system (RTPV) is lightweight, low-cost alternative to the present radioisotope thermoelectric generator system (RTG). The fabrication of such an RTPV generator has recently become feasible as the result of the invention of the GaSb infrared sensitive photovoltaic cell. Herein, we present the results of a parametric study of emitters and optical filters in conjuction with existing data on gallium antimonide cells. We compare a polished tungsten emitter with an Erbia selective emitter for use in combination with a simple dielectric filter and a gallium antimonide cell array. We find that the polished tungsten emitter is by itself a very selective emitter with low emissivity beyond 4 microns. Given a gallium antimonide cell and a tungsten emitter, a simple dielectric filter can be designed to transmit radiant energy below 1.7 microns and to reflect radiant energy between 1.7 and 4 microns back to the emitter. Because of the low long wavelength emissivity associated with the polished tungsten emitter, this simple dielectric filter then yields very respectable system performance. Also as a result of the longer wavelength fall-off in the tungsten emissivity curve, the radiation energy peak for a polished tungsten emitter operating at 1300 K shifts to shorter wavelengths relative to the blackbody spectrum so that the radiated energy peak falls right at the gallium antimonide cell bandedge. The result is that the response of the gallium antimonide cell is well matched to a polished tungsten emitter. We propose, therefore, to fabricate an operating prototype of a near term radioisotope thermophotovoltaic generator design consisting of a polished tungsten emitter, standard gallium antimonide cells, and a near-term dielectric filter. The Jet Propulsion Laboratory will design and build the thermal cavity, and JX Crystals will fabricate the gallium antimonide cells, dielectric filters, and resultant receiver panels. With 250 Watts of heat input, we expect this prototype to produce over 300 Watts of electrical energy output for a system energy conversion efficiency of over 12%. This low risk, near term design provides advances relative to present radioisotope thermophotovoltaic generators and has the additional advantage of allowing component and system development and testing to begin immediately. Improved cells and filters can easily be incorporated in this baseline system if they should become available in the future.

Mars vertical axis wind machines: The design of a tornado vortex machine for use on Mars

NASA Technical Reports Server (NTRS)

Carlin, Daun; Dyhr, Amy; Kelly, Jon; Schmirler, J. Eric; Carlin, Mike; Hong, Won E.; Mahoney, Kamin

1994-01-01

Ever since Viking 1 and 2 landed on the surface of Mars in the summer of 1976, man has yearned to go back. But before man steps foot upon the surface of Mars, unmanned missions such as the Martian Soft Lander and Martian Subsurface Penetrator will precede him. Alternative renewable power sources must be developed to supply the next generation of surface exploratory spacecraft, since RTG's, solar cells, and long-life batteries all have their significant drawbacks. One such alternative is to take advantage of the unique Martian atmospheric conditions by designing a small scale, Martian wind power generator, capable of surviving impact and fulfilling the long term (2-5 years), low-level power requirements (1-2 Watts) of an unmanned surface probe. After investigation of several wind machines, a tornado vortex generator was chosen based upon its capability of theoretically augmenting and increasing the available power that may be extracted from average Martian wind speeds of approximately 7.5 m/s. The Martian Tornado Vortex Wind Generator stands 1 meter high and has a diameter of 0.5 m. Martian winds enter the base and shroud of the Tornado Vortex Generator at 7.5 m/s and are increased to an exit velocity of 13.657 m/s due to the vortex that is created. This results in a rapid pressure drop of 4.56 kg/s(exp 2) m across the vortex core which aids in producing a net power output of 1.1765 Watts. The report contains the necessary analysis and requirements needed to feasibly operate a low-level powered, unmanned, Martian surface probe.

Mars vertical axis wind machines: The design of a tornado vortex machine for use on Mars

NASA Astrophysics Data System (ADS)

Carlin, Daun; Dyhr, Amy; Kelly, Jon; Schmirler, J. Eric; Carlin, Mike; Hong, Won E.; Mahoney, Kamin; Ralston, Michael

1994-06-01

Ever since Viking 1 and 2 landed on the surface of Mars in the summer of 1976, man has yearned to go back. But before man steps foot upon the surface of Mars, unmanned missions such as the Martian Soft Lander and Martian Subsurface Penetrator will precede him. Alternative renewable power sources must be developed to supply the next generation of surface exploratory spacecraft, since RTG's, solar cells, and long-life batteries all have their significant drawbacks. One such alternative is to take advantage of the unique Martian atmospheric conditions by designing a small scale, Martian wind power generator, capable of surviving impact and fulfilling the long term (2-5 years), low-level power requirements (1-2 Watts) of an unmanned surface probe. After investigation of several wind machines, a tornado vortex generator was chosen based upon its capability of theoretically augmenting and increasing the available power that may be extracted from average Martian wind speeds of approximately 7.5 m/s. The Martian Tornado Vortex Wind Generator stands 1 meter high and has a diameter of 0.5 m. Martian winds enter the base and shroud of the Tornado Vortex Generator at 7.5 m/s and are increased to an exit velocity of 13.657 m/s due to the vortex that is created. This results in a rapid pressure drop of 4.56 kg/s(exp 2) m across the vortex core which aids in producing a net power output of 1.1765 Watts. The report contains the necessary analysis and requirements needed to feasibly operate a low-level powered, unmanned, Martian surface probe.

Evaluation of Aqueous and Powder Processing Techniques for Production of Pu-238-Fueled General Purpose Heat Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2008-06-01

This report evaluates alternative processes that could be used to produce Pu-238 fueled General Purpose Heat Sources (GPHS) for radioisotope thermoelectric generators (RTG). Fabricating GPHSs with the current process has remained essentially unchanged since its development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the fields of chemistry, manufacturing, ceramics, and control systems. At the Department of Energy’s request, alternate manufacturing methods were compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product. An expert committee performed the evaluationmore » with input from four national laboratories experienced in Pu-238 handling.« less

KSC-97PC1092

NASA Image and Video Library

1997-07-19

Jet Propulsion Laboratory (JPL) worker Mary Reaves mates connectors on a radioisotope thermoelectric generator (RTG) to power up the Cassini spacecraft, while quality assurance engineer Peter Sorci looks on. The three RTGs which will be used on Cassini are undergoing mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed by JPL

KSC-97PC1070

NASA Image and Video Library

1997-07-18

Jet Propulsion Laboratory (JPL) workers use a borescope to verify pressure relief device bellows integrity on a radioisotope thermoelectric generator (RTG) which has been installed on the Cassini spacecraft in the Payload Hazardous Servicing Facility. The activity is part of the mechanical and electrical verification testing of RTGs during prelaunch processing. RTGs use heat from the natural decay of plutonium to generate electric power. The three RTGs on Cassini will enable the spacecraft to operate far from the Sun where solar power systems are not feasible. They will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL

KSC-97PC1064

NASA Image and Video Library

1997-07-18

Jet Propulsion Laboratory (JPL) workers carefully roll into place a platform with a second radioisotope thermoelectric generator (RTG) for installation on the Cassini spacecraft. In background at left, the first of three RTGs already has been installed on Cassini. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. The power units are undergoing mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate far from the Sun where solar power systems are not feasible. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL

Impact of MODIS High-Resolution Sea-Surface Temperatures on WRF Forecasts at NWS Miami, FL

NASA Technical Reports Server (NTRS)

Case, Jonathan L.; LaCasse, Katherine M.; Dembek, Scott R.; Santos, Pablo; Lapenta, William M.

2007-01-01

Over the past few years,studies at the Short-term Prediction Research and Transition (SPoRT) Center have suggested that the use of Moderate Resolution Imaging Spectroradiometer (MODIS) composite sea-surface temperature (SST) products in regional weather forecast models can have a significant positive impact on short-term numerical weather prediction in coastal regions. The recent paper by LaCasse et al. (2007, Monthly Weather Review) highlights lower atmospheric differences in regional numerical simulations over the Florida offshore waters using 2-km SST composites derived from the MODIS instrument aboard the polar-orbiting Aqua and Terra Earth Observing System satellites. To help quantify the value of this impact on NWS Weather Forecast Offices (WFOs), the SPoRT Center and the NWS WFO at Miami, FL (MIA) are collaborating on a project to investigate the impact of using the high-resolution MODIS SST fields within the Weather Research and Forecasting (WRF) prediction system. The scientific hypothesis being tested is: More accurate specification of the lower-boundary forcing within WRF will result in improved land/sea fluxes and hence, more accurate evolution of coastal mesoscale circulations and the associated sensible weather elements. The NWS MIA is currently running the WRF system in real-time to support daily forecast operations, using the National Centers for Environmental Prediction Nonhydrostatic Mesoscale Model dynamical core within the NWS Science and Training Resource Center's Environmental Modeling System (EMS) software; The EMS is a standalone modeling system capable of downloading the necessary daily datasets, and initializing, running and displaying WRF forecasts in the NWS Advanced Weather Interactive Processing System (AWIPS) with little intervention required by forecasters. Twenty-seven hour forecasts are run daily with start times of 0300,0900, 1500, and 2100 UTC on a domain with 4-km grid spacing covering the southern half of Florida and the far western portions of the Bahamas, the Florida Keys, the Straights of Florida, and adjacent waters of the Gulf of Mexico and Atlantic Ocean. Each model run is initialized using the Local Analysis and Prediction System (LAPS) analyses available in AWIPS, invoking the diabatic. "hot-start" capability. In this WRF model "hot-start", the LAPS-analyzed cloud and precipitation features are converted into model microphysics fields with enhanced vertical velocity profiles, effectively reducing the model spin-up time required to predict precipitation systems. The SSTs are initialized with the NCEP Real-Time Global (RTG) analyses at l/12 degree resolution (approx. 9 km); however, the RTG product does not exhibit fine-scale details consistent with its grid resolution. SPoRT is conducting parallel WRF EMS runs identical to the operational runs at NWS MIA in every respect except for the use of MODIS SST composites in place of the RTG product as the initial and boundary conditions over water. The MODIS SST composites for initializing the SPoRT WRF runs are generated on a 2-km grid four times daily at 0400, 0700, 1600, and 1900 UTC, based on the times of the overhead passes of the Aqua and Terra satellites. The incorporation of the MODIS SST composites into the SPoRTWRF runs is staggered such that the 0400UTC composite initializes the 0900 UTC WRF, the 0700 UTC composite initializes the 1500 UTC WRF, the 1600 UTC composite initializes the 2100 UTC WRF, and the 1900 UTC composite initializes the 0300 UTC WRF. A comparison of the SPoRT and Miami forecasts is underway in 2007, and includes quantitative verification of near-surface temperature, dewpoint, and wind forecasts at surface observation locations. In addition, particular days of interest are being analyzed to determine the impact of the MODIS SST data on the development and evolution of predicted sea/land-breeze circulations, clouds, and precipitation. This paper will present verification results comparing the NWS MIA forecasts the SPoRT experimental WRF forecasts, and highlight any substantial differences noted in the predicted mesoscale phenomena.

Power System for Venus Surface Exploration

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Mellott, Kenneth

2002-01-01

A radioisotope power and cooling system is designed to provide electrical power for a probe operating on the surface of Venus. Most foreseeable electronics devices and sensors cannot operate at the 450 C ambient surface temperature of Venus. Because the mission duration is substantially long and the use of thermal mass to maintain an operable temperature range is likely impractical, some type of active refrigeration may be required to keep electronic components at a temperature below ambient. The fundamental cooling parameters are the cold sink temperature, the hot sink temperature, and the amount of heat to be removed. In this instance, it is anticipated that electronics would have a nominal operating temperature of 300 C. Due to the highly thermal convective nature of the high-density (90 bar CO2) atmosphere, the hot sink temperature was assumed to be 50 C, which provided a 500 C temperature of the cooler's heat rejecter to the ambient atmosphere. The majority of the heat load on the cooler is from the high temperature ambient surface environment on Venus, with a small contribution of heat generation from electronics and sensors. Both thermoelectric (RTG) and dynamic power conversion systems were analyzed, based on use of a standard isotope (General-purpose heat source, or GPHS) brick. For the radioisotope Stirling power converter configuration designed, the Sage model predicts a thermodynamic power output capacity of 478.1 watts, which slightly exceeds the required 469.1 watts. The hot sink temperature is 1200 C, and the cold sink temperature is 500 C. The required heat input is 1740 watts. This gives a thermodynamic efficiency of 27.48 %. It is estimated that the mechanical efficiency of the power converter design is on the order of 85 %, based on experimental measurements taken from 500-watt power class, laboratory-tested Stirling engines. The overall efficiency is calculated to be 23.36 %. The mass of the power converter is estimated at approximately 21.6 kg. Additional information is included in the original extended abstract.

Nitrogen chemistry on dust grains: the formation of hydroxylamine, precursor to glycine

NASA Astrophysics Data System (ADS)

Vidali, Gianfranco; Lemaire, Jean Louis; Shi, Jianming; Hopkins, Tyler; Garrod, Rob; He, Jiao

2015-08-01

In ices coating dust grains in molecular clouds, nitrogen-containing molecules - mostly NH3 - are present in sizable quantity, up to 15-20% with respect to water ice, the largest component. We studied the oxidation of ammonia in a series of experiments using beams of oxygen and ammonia in various configurations (co-deposition and sequential deposition with various NH3:O ratios). We detected the formation of hydroxylamine (NH2OH) and other products, depending on the degree of oxidation. A simulation of a dense cloud with input from experimental data shows that on and in ices at 14 K and with modest activation energy for reaction, NH2OH is easily formed and its abundance never falls below a tenth of the NH3 abundance. Strategies for detection of hydroxylamine in the ISM will be presented.This work is supported by the NSF Astronomy and Astrophysics Division (grant No.1311958 to G.V.). R.T.G. acknowledges the support of the NASA Astrophysics Theory Program (grant No. NNX11AC38G).

Selective clearance of aberrant tau proteins and rescue of neurotoxicity by transcription factor EB.

PubMed

Polito, Vinicia A; Li, Hongmei; Martini-Stoica, Heidi; Wang, Baiping; Yang, Li; Xu, Yin; Swartzlander, Daniel B; Palmieri, Michela; di Ronza, Alberto; Lee, Virginia M-Y; Sardiello, Marco; Ballabio, Andrea; Zheng, Hui

2014-09-01

Accumulating evidence implicates impairment of the autophagy-lysosome pathway in Alzheimer's disease (AD). Recently discovered, transcription factor EB (TFEB) is a molecule shown to play central roles in cellular degradative processes. Here we investigate the role of TFEB in AD mouse models. In this study, we demonstrate that TFEB effectively reduces neurofibrillary tangle pathology and rescues behavioral and synaptic deficits and neurodegeneration in the rTg4510 mouse model of tauopathy with no detectable adverse effects when expressed in wild-type mice. TFEB specifically targets hyperphosphorylated and misfolded Tau species present in both soluble and aggregated fractions while leaving normal Tau intact. We provide in vitro evidence that this effect requires lysosomal activity and we identify phosphatase and tensin homolog (PTEN) as a direct target of TFEB that is required for TFEB-dependent aberrant Tau clearance. The specificity and efficacy of TFEB in mediating the clearance of toxic Tau species makes it an attractive therapeutic target for treating diseases of tauopathy including AD. © 2014 The Authors. Published under the terms of the CC BY 4.0 license.

Stirling Engine Controller

NASA Technical Reports Server (NTRS)

Blaze, Gina M.

2004-01-01

Stirling technology is being developed to replace RTG s (Radioisotope Thermoelectric Generators), more specifically a stirling convertor, which is a stirling engine coupled to a linear alternator. Over the past three decades, the stirling engine has been designed to perform different functions. Stirling convertors have been designed to decrease fuel consumption in automobiles. They have also been designed for terrestrial and space applications. Currently NASA Glenn is using the convertor for space based applications. A stiring converter is a better means of power for deep space mission and "dusty" mission, like the Mars Rovers, than solar panels because it is not affected by dust. Spirit and Opportunity, two Mars rovers currently navigating the planet, are losing their ability to generate electricity because dust is collecting on their solar panels. Opportunity is losing more energy because its robotic arm has a heater with a switch that can not be turned off. The heater is not needed at night, but yet still runs. This generates a greater loss of electricity and in turn diminishes the performance of the rover. The stirling cycle has the potential to provide very efficient conversion of heat energy to electric a1 energy, more so than RTG's. The stirling engine converts the thermal energy produced by the decaying radioisotope to mechanical energy; the linear alternator converts this into electricity. convertor. Since the early 1990's tests have been performed to maximize the efficiency of the stirling converter. Many months, even years, are dedicated to preparing and performing tests. Currently, two stirling convertors #'s 13 and 14, which were developed by Stirling Technology Company, are on an extended operation test. As of June 7th, the two convertors reached 7,500 hours each of operation. Before the convertors could run unattended, many safety precautions had to be examined. So, special instrumentation and circuits were developed to detect off nominal conditions and also safely shutdown the engines. The test will last for a period of 8000 to 9000 hours. Other types of tests that have been performed are: performance mapping, controller development, launch environment, and vibration emissions testing. Currently, the thermo-mechanical system branch is housing a RG-350, a stirling convertor. The convertor was used in previous tests such as a Hall Thruster test, world s first integrated test of a dynamic power system with electric propulsion. Another test performed was to conclude if free piston stirling convertors can be synchronized for vibration balancing, with no thermodynamic or electrical connections and not cause both to shutdown if one failed. The ability to reduce vibration by synchronizing convertor operation but still be able to operate when one partner fails is pertinent in space and terrestrial applications. The convertor is now being brought back into operation and a controller is in the process of being developed. This convertor will be used as a testbed for new controllers. I worked with Mary Ellen Roth on the electric engineering aspects of the RG-350. My main goal was to enhance the data collection process. I worked on different aspects of the RG-350, with a main focus on the engine controller. I drew a schematic of the wire connections in the engine controller, using PCB Express, so that a plan could be devised to connect the power meter properly between the output of the engine and the engine controller. I measured the power using two different instruments: Valhalla Scientific power meter and Ohio Semitronics power measurement device. The convertor is connected to an Agilent 34970A Data Acquisition/Switch Unit, which allows the user to measure, record, and monitor voltage, current, frequency, and temperature. I assisted in preparing the Data Acquisition for general operation. I also helped test a panel of transducers, which will be placed in the rack that powers and monitors the convertor.

Cassini's RTGs undergo mechanical and electrical verification tests in the PHSF

NASA Technical Reports Server (NTRS)

1997-01-01

Jet Propulsion Laboratory (JPL) worker Mary Reaves mates connectors on a radioisotope thermoelectric generator (RTG) to power up the Cassini spacecraft, while quality assurance engineer Peter Sorci looks on. The three RTGs which will be used on Cassini are undergoing mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed by JPL.

KSC-97PC1094

NASA Image and Video Library

1997-07-19

Jet Propulsion Laboratory (JPL) employees bolt a radioisotope thermoelectric generator (RTG) onto the Cassini spacecraft, at left, while other JPL workers, at right, operate the installation cart on a raised platform in the Payload Hazardous Servicing Facility (PHSF). Cassini will be outfitted with three RTGs. The power units are undergoing mechanical and electrical verification tests in the PHSF. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed by JPL

Structured Doctoral Education in Hannover - Joint Programme IMPRS-GW and geo-Q RTG

NASA Astrophysics Data System (ADS)

Kawazoe, Fumiko; Bruns, Sandra

2018-02-01

Two structured doctoral programmes that we have in Hannover, the IMPRS on Gravitational Wave Astronomy and SFB on relativistic geodesy and gravimetry with quantum sensors geo-Q, have not only become major resources for education in each field but have also started to provide substantial synergy to members of both programmes. Our strong crossdisciplinary approach to create a joint programme has received excellent feedback not only from researchers inside the programme but also from various external committee. Building on experience that we have acquired over the last decade, we propose to set up a common doctoral programme within the international gravitational wave astronomy and physics. We envisage that with a common doctoral programme we will create a strong team of young researchers who will carry on building a strong network of third generation gravitational wave detectors and observatories.

INTERNATIONAL COOPERATION ON RADIOLOGICAL THREAT REDUCTION PROGRAMS IN RUSSIA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landers, Christopher C.; Tatyrek, Aaron P.

Since its inception in 2004, the United States Department of Energy’s Global Threat Reduction Initiative (GTRI) has provided the Russian Federation with significant financial and technical assistance to secure its highly vulnerable and dangerous radiological material. The three program areas of this assistance are the removal of radioisotope thermoelectric generators (RTG), the physical protection of vulnerable in-use radiological material of concern, and the recovery of disused or abandoned radiological material of concern. Despite the many successes of the GTRI program in Russia, however, there is still a need for increased international cooperation in these efforts. Furthermore, concerns exist over howmore » the Russian government will ensure that the security of its radiological materials provided through GTRI will be sustained. This paper addresses these issues and highlights the successes of GTRI efforts and ongoing activities.« less

Cassini's RTGs undergo mechanical and electrical verification testing in the PHSF

NASA Technical Reports Server (NTRS)

1997-01-01

Jet Propulsion Laboratory (JPL) workers carefully roll into place a platform with a second radioisotope thermoelectric generator (RTG) for installation on the Cassini spacecraft. In background at left, the first of three RTGs already has been installed on Cassini. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. The power units are undergoing mechanical and electrical verification testing in the Payload Hazardous Servicing Facility. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate far from the Sun where solar power systems are not feasible. The Cassini mission is scheduled for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed for NASA by JPL.

Marketing practitioner’s tacit knowledge acquisition using Repertory Grid Technique (RTG)

NASA Astrophysics Data System (ADS)

Azmi, Afdhal; Adriman, Ramzi

2018-05-01

The tacit knowledge of Marketing practitioner’s experts is excellent resources and priceless. It takes into account their experiential, skill, ideas, belief systems, insight and speculation into management decision-making. This expertise is an individual intuitive judgment and personal shortcuts to complete the work efficiently. Tacit knowledge of Marketing practitioner’s experts is one of best problem solutions in marketing strategy, environmental analysis, product management and partner’s relationship. This paper proposes the acquisition method of tacit knowledge from Marketing practitioner’s using Repertory Grid Technique (RGT). The RGT is a software application for tacit acquisition knowledge to provide a systematic approach to capture and acquire the constructs from an individual. The result shows the understanding of RGT could make TKE and MPE get a good result in capturing and acquiring tacit knowledge of Marketing practitioner’s experts.

Partial view of the deployed Apollo Lunar Surface Experiments Package

NASA Image and Video Library

1972-04-21

AS16-113-18347 (21 April 1972) --- A partial view of the Apollo 16 Apollo Lunar Surface Experiments Package (ALSEP) in deployed configuration on the lunar surface as photographed during the mission's first extravehicular activity (EVA), on April 21, 1972. The Passive Seismic Experiment (PSE) is in the foreground center; Central Station (C/S) is in center background, with the Radioisotope Thermoelectric Generator (RTG) to the left. One of the anchor flags for the Active Seismic Experiment (ASE) is at right. While astronauts John W. Young, commander; and Charles M. Duke Jr., lunar module pilot; descended in the Apollo 16 Lunar Module (LM) "Orion" to explore the Descartes highlands landing site on the moon, astronaut Thomas K. Mattingly II, command module pilot, remained with the Command and Service Modules (CSM) "Casper" in lunar orbit.

Potential health risks from postulated accidents involving the Pu-238 RTG on the Ulysses solar exploration mission

NASA Technical Reports Server (NTRS)

Goldman, Marvin; Hoover, Mark D.; Nelson, Robert C.; Templeton, William; Bollinger, Lance; Anspaugh, Lynn

1991-01-01

Potential radiation impacts from launch of the Ulysses solar exploration experiment were evaluated using eight postulated accident scenarios. Lifetime individual dose estimates rarely exceeded 1 mrem. Most of the potential health effects would come from inhalation exposures immediately after an accident, rather than from ingestion of contaminated food or water, or from inhalation of resuspended plutonium from contaminated ground. For local Florida accidents (that is, during the first minute after launch), an average source term accident was estimated to cause a total added cancer risk of up to 0.2 deaths. For accidents at later time after launch, a worldwide cancer risk of up to three cases was calculated (with a four in a million probability). Upper bound estimates were calculated to be about 10 times higher.

Real life pharmaceutical treatment patterns for adult patients with focal epilepsy in Germany: a longitudinal and cross-sectional analysis of recently approved anti-epileptic drugs

PubMed Central

Groth, Antje; Wilke, Thomas; Borghs, Simon; Gille, Patrick; Joeres, Lars

2017-01-01

Objectives: The aim of this study was to investigate the antiepileptic drug (AED) treatment of adults suffering from focal epilepsies (FE) in Germany. Of special interest was the number and percentage of the patients 16 years and older receiving no treatment with an AED, treatment with one AED (monotherapy), treatment with more than one AED, and treatment with a novel AED. The definition for “novel” was newly approved at the time of market entry since 2006 (last 10 years): eslicarbazepine (ESL), lacosamide (LCM), perampanel (PER), and retigabine (RTG). Methods: The analysis was based on a claims data set covering the years 2007 to 2014, provided by AOK PLUS, a German statutory health insurance. Two patient samples were defined: (1) prevalent patients suffering from FE (at least one in- or outpatient diagnosis of FE and at least one prescription of an AED), and (2) incident FE patients (first in- or outpatient diagnosis of FE without any previous diagnoses/AED prescriptions in the preceding 6 months). Patient observation started at date of first observed inpatient or outpatient focal epilepsy diagnosis within the analyzed period. Each patient was classified as a “no AED therapy”, “AED monotherapy” or “more than one AED therapy”. Patients were analyzed by number and type of concomitantly prescribed AEDs in yearly tranches (no, one, two, three, four, more than four AEDs; novel versus non-novel AEDs). Results: A total of 34,422 patients diagnosed with FE aged 16 year or older (mean age 59.6 years, 48.7% female) were identified. The mean follow-up period was 1,891 days (5.2 years) since first confirmed diagnosis. The percentage of prevalent patients diagnosed with FE who received one AED (monotherapy) was stable overall and ranged between a minimum of 66.2% (2007) and a maximum of 68.9% (2010). The percentage of patients who received two AEDs ranged from 23.6% (2012) to 25.8% (2007). The remaining patients received therapies with three (6.0% in 2010 to 6.7% in 2007), four (1.0% in 2010 to 1.2% in 2009) or more than four AEDs (0.1% in 2014 to 0.3% in 2013). Between 8.1%–16.6% (2007; 2014) of the patients received no AED therapy in the observed period. In the first year after the diagnosis of FE (incident patients), 9.7% of patients didn’t receive any AED therapy. Of those treated with at least one AED, 80.0% received one AED (monotherapy) only, 17.0% received therapy with two AEDs, 2.6% with three AEDs, 0.3% with four AEDs, and 0.1% with >4 AEDs during the respective observation time window and remained stable throughout the four-year follow-up period. Of prevalent patients with a diagnosis of FE, 1,889 (5.5%) received at least one prescription of a novel AED during the observation period; 98.6% of these patients received the novel AED in combination with at least one other AED. Of those patients, 269 (14.2%) received >1 novel AED. The analysis of the patients receiving novel AEDs by the time from the first confirmed diagnosis of FE until the prescription of a novel AED resulted in a mean duration of 4.0 years (SD 2.0) for ESL, 3.6 years (SD 2.2) for LCM, 5.7 years (SD 1.2) for PER, and 4.6 years (SD 0.8 years) for RTG. The mean number of AEDs prescribed before the novel AEDs were 3.2 for ESL, 2.4 for LCM, 5.0 for PER and 5.2 for RTG. Conclusions: Most patients aged 16 years or older, suffering from focal seizures, received AED monotherapy. Novel AEDs were prescribed in a small proportion of patients (<6%) and relatively late in the treatment course. These results are consistent with the recommendations of the German Society for Epileptology (Deutsche Gesellschaft für Epileptologie, DGfE) which suggests a number of monotherapy options – these options do not include the novel AEDs described in this study. PMID:28638313

KSC-2011-6674

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Outside the RTG storage facility at NASA's Kennedy Space Center in Florida, the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission, enclosed in the protective mesh container, known as the "gorilla cage," is positioned inside the MMRTG trailer that will transport it to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6738

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- A crane is positioned over the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission in the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida. Preparations are under way to lift the mesh container, known as the "gorilla cage," from the support base on which the MMRTG is resting. The cage protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. The MMRTG is returning to the RTGF following a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6664

NASA Image and Video Library

2011-06-30

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, a Department of Energy contractor employee guides the external and internal protective layers of the shipping cask as they are lifted from around the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory mission. The MMRTG no longer needs supplemental cooling since any excess heat generated can dissipate into the air in the high bay. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for evidence on whether Mars has had environments favorable to microbial life, including chemical ingredients for life. The unique rover will use a laser to look inside rocks and release its gasses so that the rover’s spectrometer can analyze and send the data back to Earth. Launch of MSL aboard a United Launch Alliance Atlas V rocket is scheduled for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station in Florida. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Frankie Martin

KSC-2011-6719

NASA Image and Video Library

2011-07-13

CAPE CANAVERAL, Fla. -- In the airlock of the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, Department of Energy employees lower the mesh container, known as the "gorilla cage," toward the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission. The mobile plexiglass radiation shields in the foreground help minimize the employees' radiation exposure. The cage protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. Transport of the MMRTG to the RTG storage facility follows the completion of the MMRTG fit check on the Curiosity rover. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Kim Shiflett

KSC-2011-6741

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida, Department of Energy workers guide the mesh container enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission as it is lifted by a crane. The container, known as the "gorilla cage," protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. The cage is being removed from around the MMRTG following it return to the RTGF from a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6673

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Outside the RTG storage facility at NASA's Kennedy Space Center in Florida, a forklift positions the protective mesh container, known as the "gorilla cage," enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission inside the MMRTG trailer that will transport it to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6739

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida, Department of Energy workers attach a crane to the mesh container enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission. The container, known as the "gorilla cage," protects it during transport and allows any excess heat generated to dissipate into the air. The cage is being removed from around the MMRTG following it return to the RTGF from a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6720

NASA Image and Video Library

2011-07-13

CAPE CANAVERAL, Fla. -- In the airlock of the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, a Department of Energy employee positions the mesh container, known as the "gorilla cage," on the support base of the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission. The mobile plexiglass radiation shields, in the foreground at right, helps minimize the employees' radiation exposure. The cage protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. Transport of the MMRTG to the RTG storage facility follows the completion of the MMRTG fit check on the Curiosity rover. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Kim Shiflett

KSC-2011-6676

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Outside the RTG storage facility at NASA's Kennedy Space Center in Florida, the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission, enclosed in the protective mesh container known as the "gorilla cage," is strapped down inside the MMRTG trailer and ready for transport to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6670

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Outside the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida, a forklift picks up the protective mesh container, known as the "gorilla cage," enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission for its move to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6669

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Department of Energy contractor employees roll the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission, enclosed in a protective mesh container known as the "gorilla cage," toward a forklift outside the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida for its move to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6672

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Outside the RTG storage facility at NASA's Kennedy Space Center in Florida, a forklift carries the protective mesh container, known as the "gorilla cage," enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission toward the MMRTG trailer that will transport it to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6668

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Department of Energy contractor employees roll the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission, enclosed in a protective mesh container known as the "gorilla cage," out of the high bay of the RTG storage facility at NASA's Kennedy Space Center in Florida for its move to the Payload Hazardous Servicing Facility (PHSF). The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. In the PHSF, the MMRTG temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6718

NASA Image and Video Library

2011-07-13

CAPE CANAVERAL, Fla. -- In the airlock of the Payload Hazardous Servicing Facility at NASA's Kennedy Space Center in Florida, Department of Energy employees lower the mesh container, known as the "gorilla cage," toward the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission. The employees are standing behind mobile plexiglass radiation shields to help minimize the employees' radiation exposure. The cage protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. Transport of the MMRTG to the RTG storage facility follows the completion of the MMRTG fit check on the Curiosity rover. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Kim Shiflett

Small space reactor power systems for unmanned solar system exploration missions

NASA Technical Reports Server (NTRS)

Bloomfield, Harvey S.

1987-01-01

A preliminary feasibility study of the application of small nuclear reactor space power systems to the Mariner Mark II Cassini spacecraft/mission was conducted. The purpose of the study was to identify and assess the technology and performance issues associated with the reactor power system/spacecraft/mission integration. The Cassini mission was selected because study of the Saturn system was identified as a high priority outer planet exploration objective. Reactor power systems applied to this mission were evaluated for two different uses. First, a very small 1 kWe reactor power system was used as an RTG replacement for the nominal spacecraft mission science payload power requirements while still retaining the spacecraft's usual bipropellant chemical propulsion system. The second use of reactor power involved the additional replacement of the chemical propulsion system with a small reactor power system and an electric propulsion system. The study also provides an examination of potential applications for the additional power available for scientific data collection. The reactor power system characteristics utilized in the study were based on a parametric mass model that was developed specifically for these low power applications. The model was generated following a neutronic safety and operational feasibility assessment of six small reactor concepts solicited from U.S. industry. This assessment provided the validation of reactor safety for all mission phases and generatad the reactor mass and dimensional data needed for the system mass model.

U-series Chronology of volcanoes in the Central Kenya Peralkaline Province, East African Rift

NASA Astrophysics Data System (ADS)

Negron, L. M.; Ma, L.; Deino, A.; Anthony, E. Y.

2012-12-01

We are studying the East African Rift System (EARS) in the Central Kenya Peralkaline Province (CKPP), and specifically the young volcanoes Mt. Suswa, Longonot, and Menengai. Ar dates by Al Deino on K-feldspar phenocrysts show a strong correlation between older Ar ages and decreasing 230Th/232Th, which we interpret to reflect the age of eruption. This system has been the subject of recent research done by several UTEP alumni including Antony Wamalwa using potential field and magnetotelluric (MT) data to identify and characterize fractures and hydrothermal fluids. Also research on geochemical modeling done by John White, Vanessa Espejel and Peter Omenda led to the hypothesis of possible disequilibrium in these young, mainly obsidian samples in their post eruptive history. A pilot study of 8 samples, (also including W-2a USGS standard and a blank) establish the correlation that was seen between the ages found by Deino along with the 230/232Th ratios. All 8 samples from Mt. Suswa showed a 234U/238U ratio of (1) which indicates secular equilibrium or unity and that these are very fresh samples with no post-eruptive decay or leaching of U isotopes. The pilot set was comprised of four samples from the ring-trench group (RTG) with ages ranging from 7ka-present, two samples from the post-caldera stage ranging from 31-10ka, one sample from the syn-caldera stage dated at 41ka, and one sample from the pre-caldera stage dated at 112ka. The young RTG had a 230/232Th fractionation ratio of 0.8 ranging to the older pre-caldera stage with a 230/232Th ratio of 0.6. From this current data and research of 14C ages by Nick Rogers, the data from Longonot volcano was also similar to the 230/232Th ratio we found. Rogers' data places Longonot volcano ages to be no more than 20ka with the youngest samples also roughly around 0.8 disequilibrium. These strong correlations between the pilot study done for Mt. Suswa, 40Ar ages by Deino, along with 14C ages from Rogers have led to the exploration of present U-series data set of the youngest samples from the rest of the CKPP volcanoes including: Menengai, more from Longonot, and Olkaria. And since it is observed that there is the presence of lateral migration along an axial dike swarm that has operated in other parts of the EARS, we have chosen to run samples from the adjacent mafic fields of Elmenteita, Tandamara, and Ndabibi to see if there is a trend in the correlation of the 230/232Th ratios at the time of eruption as well as observing how close these samples get to unity. This would answer questions as to whether similar 230/232Th ratios imply that the mafic fields feed the calderas.

Cassini's RTGs undergo mechanical and electrical verification tests in the PHSF

NASA Technical Reports Server (NTRS)

1997-01-01

Jet Propulsion Laboratory (JPL) employees bolt a radioisotope thermoelectric generator (RTG) onto the Cassini spacecraft, at left, while other JPL workers, at right, operate the installation cart on a raised platform in the Payload Hazardous Servicing Facility (PHSF). Cassini will be outfitted with three RTGs. The power units are undergoing mechanical and electrical verification tests in the PHSF. The RTGs will provide electrical power to Cassini on its 6.7-year trip to the Saturnian system and during its four-year mission at Saturn. RTGs use heat from the natural decay of plutonium to generate electric power. The generators enable spacecraft to operate at great distances from the Sun where solar power systems are not feasible. The Cassini mission is targeted for an Oct. 6 launch aboard a Titan IVB/Centaur expendable launch vehicle. Cassini is built and managed by JPL.

Sublimation behavior of silicon nitride /Si3N4/ coated silicon germanium /SiGe/ unicouples. [for Radioisotope Thermoelectric Generators

NASA Technical Reports Server (NTRS)

Stapfer, G.; Truscello, V. C.

1975-01-01

For the Multi-Hundred Watt (MHW) Radioisotope Thermoelectric Generator (RTG), the silicon germanium unicouples are coated with silicon nitride to minimize degradation mechanisms which are directly attributable to material sublimation effects. A program is under way to determine the effective vapor suppression of this coating as a function of temperature and gas environment. The results of weight loss experiments, using Si3N4 coated hot shoes (SiMo), operating over a temperature range from 900 C to 1200 C, are analyzed and discussed. These experiments were conducted both in high vacuum and at different pressures of carbon monoxide (CO) to determine its effect on the coating. Although the results show a favorable vapor suppression at all operating temperatures, the pressure of the CO and the thickness of the coating have a decided effect on the useful lifetime of the coating.

Fish Rhabdovirus Cell Entry Is Mediated by Fibronectin

PubMed Central

Bearzotti, Monique; Delmas, Bernard; Lamoureux, Annie; Loustau, Anne-Marie; Chilmonczyk, Stefan; Bremont, Michel

1999-01-01

Three monoclonal antibodies (MAbs) generated against rainbow trout gonad cells (RTG-2) have been selected for their ability to protect cells from the viral hemorrhagic septicemia virus (VHSV) infection, a salmonid rhabdovirus. Protection from infection was restricted to the salmonid-derived cell lines indicating species specificity of the blocking MAbs. Surprisingly, the blocking activity of these MAbs was also effective against other nonantigenically related fish rhabdoviruses. Indirect immunofluorescence and immunoelectron microscopy observations demonstrated that the three MAbs were all directed against an abundant cell plasma membrane component, and immunoprecipitation studies indicated that the target consisted of a heterodimeric complex with molecular masses of 200 and 44 kDa. Biochemical data provided the following evidence that fibronectin is part of this complex and that it could represent the main receptor for fish rhabdoviruses. (i) An antiserum generated against the 200-kDa protein reacted against the recombinant rainbow trout fibronectin expressed in Escherichia coli. (ii) The purified rainbow trout fibronectin was able to bind specifically to VHSV. To our knowledge, this is the first identification of a cellular component acting as a primary receptor for a virus replicating in lower vertebrates and, more interestingly, for viruses belonging to the Rhabdoviridae family. PMID:10438860

Heave and Flow: Understanding the role of resonance and shape evolution for heaving flexible panels

NASA Astrophysics Data System (ADS)

Hoover, Alexander; Cortez, Ricardo; Tytell, Eric; Fauci, Lisa

2017-11-01

Many animals that swim or fly use their body to accelerate the fluid around them, transferring momentum from their bodies to the surrounding fluid. The emergent kinematics from this transfer are a result of the coupling between the fluid and the material properties of the body. Here we present a computational study of a 3-dimensional flexible panel that is heaved at its leading edge in an incompressible, viscous fluid. These high-fidelity numerical simulations enable us to examine the role of resonance, fluid forces, and panel deformations have on swimming performance. Varying both the passive material properties and the heaving frequency of the panel, we find peaks in trailing edge amplitude and forward swimming speed are determined by a dimensionless quantity, the effective flexibility. Modal decompositions of panel deflections reveal that the strength of each mode is related to the effective flexibility and peaks in the swimming speed and trailing edge amplitude correspond to peaks in the contributions of different modes. Panels of different material properties but with similar effective flexibilities have modal contributions that evolve similarly over the phase of the heaving cycle and agreement in dominant vortex structures generated by the panel. NSF RTG 1043626.

SAGA complex and Gcn5 are necessary for respiration in budding yeast.

PubMed

Canzonetta, Claudia; Leo, Manuela; Guarino, Salvatore Rocco; Montanari, Arianna; Francisci, Silvia; Filetici, Patrizia

2016-12-01

In budding yeast, growth through fermentation and/or respiration is dependent on the type of carbon source present in the medium. SAGA complex is the main acetylation complex and is required, together with Rtg factors, for nucleus-mitochondria communication and transcriptional activation of specific nuclear genes. Even though acetylation is necessary for mitochondria activity and respiratory pathways the direct role of histone acetyltransferases and SAGA complex has never been investigated directly. In this study we demonstrate, for the first time, that Gcn5 and SAGA are needed for respiratory metabolism and oxygen consumption. According to a central role for acetylation in respiration we find that the Gcn5 inhibitor CPTH2 had higher efficacy on cells grown in glycerol containing media. We also demonstrated that the opposing activities of Gcn5 and Hda1 modify selectively H3-AcK18 and are essential for respiration. Taken together our results suggest a novel paradigm coupling acetyltransferase activity to respiratory metabolism. Correspondingly we propose the selective utilization of KAT inhibitor CPTH2, combined to the modulation of the respiratory metabolism of the cell, as a promising novel tool of intervention in cancer cells. Copyright © 2016 Elsevier B.V. All rights reserved.

Mars Science Laboratory Rover Integrated Pump Assembly Bellows Jamming Failure

NASA Technical Reports Server (NTRS)

Johnson, Michael R.; Johnson, Joel; Birur, Gajanana; Bhandari, Pradeep; Karlmann, Paul

2012-01-01

The Mars Science Laboratory rover and spacecraft utilize two mechanically pumped fluid loops for heat transfer to and from the internal electronics assemblies and the Radioisotope Thermo-Electric Generator (RTG). The heat transfer fluid is Freon R-11 (CFC-11) which has a large coefficient of thermal expansion. The Freon within the heat transfer system must have a volume for safe expansion of the fluid as the system temperature rises. The device used for this function is a gas-over-liquid accumulator. The accumulator uses a metal bellows to separate the fluid and gas sections. During expansion and contraction of the fluid in the system, the bellows extends and retracts to provide the needed volume change. During final testing of a spare unit, the bellows would not extend the full distance required to provide the needed expansion volume. Increasing the fluid pressure did not loosen the jammed bellows either. No amount of stroking the bellows back and forth would get it to pass the jamming point. This type of failure, if it occurred during flight, would result in significant overpressure of the heat transfer system leading to a burst failure at some point in the system piping. A loss of the Freon fluid would soon result in a loss of the mission. The determination of the source of the jamming of the bellows was quite elusive, leading to an extensive series of tests and analyses. The testing and analyses did indicate the root cause of the failure, qualitatively. The results did not provide a set of dimensional limits for the existing hardware design that would guarantee proper operation of the accumulator. In the end, a new design was developed that relied on good engineering judgment combined with the test results to select a reliable enough solution that still met other physical constraints of the hardware, the schedule, and the rover system.

In vitro evaluation of cellular responses induced by ZnO nanoparticles, zinc ions and bulk ZnO in fish cells.

PubMed

Fernández, Dolores; García-Gómez, Concepción; Babín, Mar

2013-05-01

Zinc oxide nanoparticles (ZnO-NPs) are inevitably released into the environment and are potentially dangerous for aquatic life. However, the potential mechanisms of cytotoxicity of zinc nanoparticles remain unclear. Studying the toxicity of ZnO-NPs with In vitro systems will help to determine their interactions with cellular biomolecules. The aim of this study was to evaluate the cytotoxic potentials of ZnO-NPs in established fish cell lines (RTG-2, RTH-149 and RTL-W1) and compare them with those of bulk ZnO and Zn(2+) ions. Membrane function (CFDA-AM assay), mitochondrial function (MTT assay), cell growth (KBP assay), cellular stress (β-galactosidase assay), reductase enzyme activity (AB assay), reactive oxygen species (ROS), total glutathione cellular content (tGSH assay) and glutathione S-transferase (GST) activities were assessed for all cell lines. ZnO-NPs cytotoxicity was greater than those of bulk ZnO and Zn(2+). ZnO-NPs induced oxidative stress is dependent on their dose. Low cost tests, such as CFDA-AM, ROS, GST activity and tGSH cell content test that use fish cell lines, may be used to detect oxidative stress and redox status changes. Particle dissolution of the ZnO-NPs did not appear to play an important role in the observed toxicity in this study. Published by Elsevier B.V.

KSC-2011-6742

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida, the mesh container enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission is lifted from around the MMRTG. The container, known as the "gorilla cage," protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. The cage is being removed following the return of the MMRTG to the RTGF from a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The workers at right are observing the operation from behind a mobile plexiglass radiation shield to minimize their radiation exposure. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

KSC-2011-6671

NASA Image and Video Library

2011-07-12

CAPE CANAVERAL, Fla. -- Outside the RTG storage facility at NASA's Kennedy Space Center in Florida, a plexiglass shield has been installed on the forklift enlisted to move the protective mesh container, known as the "gorilla cage," enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission. The shield minimizes the amount of debris dispersed by the wheels of the forklift that can contact the gorilla cage. The cage protects the MMRTG and allows any excess heat generated to dissipate into the air. The MMRTG is being moved to the Payload Hazardous Servicing Facility (PHSF) where it temporarily will be installed on the MSL rover, Curiosity, for a fit check but will be installed on the rover for launch at the pad. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. Curiosity, MSL's car-sized rover, has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is planned for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Cory Huston

KSC-2011-6740

NASA Image and Video Library

2011-07-14

CAPE CANAVERAL, Fla. -- In the high bay of the RTG storage facility (RTGF) at NASA's Kennedy Space Center in Florida, Department of Energy workers guide the mesh container enclosing the multi-mission radioisotope thermoelectric generator (MMRTG) for NASA's Mars Science Laboratory (MSL) mission as it is lifted by a crane. The container, known as the "gorilla cage," protects the MMRTG during transport and allows any excess heat generated to dissipate into the air. The cage is being removed from around the MMRTG following it return to the RTGF from a fit check on MSL's Curiosity rover in the Payload Hazardous Servicing Facility (PHSF). The workers at right are observing the operation from behind a mobile plexiglass radiation shield to minimize their radiation exposure. The MMRTG will generate the power needed for the mission from the natural decay of plutonium-238, a non-weapons-grade form of the radioisotope. Heat given off by this natural decay will provide constant power through the day and night during all seasons. MSL's components include a compact car-sized rover, Curiosity, which has 10 science instruments designed to search for signs of life, including methane, and help determine if the gas is from a biological or geological source. Waste heat from the MMRTG will be circulated throughout the rover system to keep instruments, computers, mechanical devices and communications systems within their operating temperature ranges. Launch of MSL aboard a United Launch Alliance Atlas V rocket is targeted for Nov. 25 from Space Launch Complex 41 on Cape Canaveral Air Force Station. For more information, visit http://www.nasa.gov/msl. Photo credit: NASA/Troy Cryder

Suppression of KV7/KCNQ potassium channel enhances neuronal differentiation of PC12 cells.

PubMed

Zhou, Najing; Huang, Sha; Li, Li; Huang, Dongyang; Yan, Yunli; Du, Xiaona; Zhang, Hailin

2016-10-01

Membrane potential shift driven by electrical activity is critical in determining the cell fate of proliferation or differentiation. As such, the ion channels that underlie the membrane electrical activity play an important role in cell proliferation/differentiation. KV7/KCNQ potassium channels are critical in determining the resting membrane potentials in many neuronal cells. However, the role of these channels in cell differentiation is not well studied. In the present study, we used PC12 cells as well as primary cultured rat cortical neurons to study the role and mechanism of KV7/KCNQ in neuronal differentiation. NGF induced PC12 cell differentiation into neuron-like cells with growth of neurites showing typical growth cone-like extensions. The Kv7/KCNQ blocker XE991 promoted NGF-induced neurite outgrowth, whereas Kv7/KCNQ opener retigabine (RTG) inhibited outgrowth. M-type Kv7 channels are likely involved in regulating neurite growth because overexpression of KCNQ2/Q3 inhibited neurite growth whereas suppression of KCNQ2/Q3 with shRNA promoted neurite growth. Membrane depolarization possibly underpins enhanced neurite growth induced by the suppression of Kv7/KCNQ. Additionally, high extracellular K(+) likely induced membrane depolarization and also promoted neurite growth. Finally, T-type Ca(2+) channels may be involved in membrane-depolarization-induced neurite growth. This study provides a new perspective for understanding neuronal differentiation as well as KV7/KCNQ channel function. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

(abstract) PV Technology for Low Intensity, Low Temperature (LILT) Applications

NASA Technical Reports Server (NTRS)

Stella, Paul M.; Pool, Frederick S.; Nicolet, Marc A.; Iles, Peter A.

1994-01-01

As a result of the recent NASA emphasis on smaller, lower cost space missions, PV is now being considered for a number of missions operating at solar distances of 3 AU or greater. In the past, many of these missions would utilize an RTG (radioisotope thermoelectric generator). Historically, silicon solar cell behavior at these distances has been compromised by a number of mechanisms including shunting, nonohmic back contacts, and the 'broken knee' curve shape. The former two can usually be neglected for modern silicon cells, but the latter has not been eliminated. This problem has been identified with localized diffusion at the top contact/silicon interface which leads to structural changes at the local junction. This is believed to create a resistive metal-semiconductor-like (MSL) interface in parallel with the junction which results in the characteristic forms of the LILT (low intensity, low temperature) 'broken knee'. This paper discusses a TaSiN contact barrier that will prevent the MSL structure in the junction.

PV Technology for Low Intensity, Low Temperature (LILT) Applications

NASA Technical Reports Server (NTRS)

Stella, Paul M.; Pool, Frederick S.; Nicolet, Marc A.; Iles, Peter A.

1994-01-01

As a result of the recent NASA emphasis on smaller, lower cost space missions, PV is now being considered for a number of missions operating at solar distances of 3 AU or greater. In the past, many of these missions would utilize an RTG (radioisotope thermoelectric generator). Historically, silicon solar cell behavior at these distances has been compromised by a number of mechanisms including shunting, nonohmic back contacts, and the 'broken knee' curve shape. The former two can usually be neglected for modern silicon cells, but the latter has not been eliminated. This problem has been identified with localized diffusion at the top contact/silicon interface which leads to structural changes at the local junction. This is believed to create a resistive metal-semiconductor-like (MSL) interface in parallel with the junction which results in the characteristic forms of the LILT (low intensity, low temperature) 'broken knee'. This paper discusses a TaSiN contact barrier that will prevent the MSL structure in the junction.

Management experience of an international venture in space The Ulysses mission

NASA Technical Reports Server (NTRS)

Yoshida, Ronald Y.; Meeks, Willis G.

1986-01-01

The management of the Ulysses project, a probe which will fly a solar polar orbit, is described. The 5-yr mission will feature a flyby of Jupiter to deflect the spacecraft into a high-inclination orbit. Data on the solar corona, solar wind, the sun-wind interface, the heliospheric magnetic field, solar and nonsolar cosmic rays, etc., will be gathered as a function of the solar latitude. NASA will track and control the probe with the Deep Space Network. JPL provides project management for NASA while the Directorate of Scientific Programs performs ESA management functions. The DOE will provide a radioisotope thermoelectric generator while NASA and ESA each supply half the scientific payload. A NASA-ESA Joint Working Group meets about twice per year to monitor the project and discuss the technical and scientific requirements. Safety issues and measures which are being addressed due to the presence of the Pu-238 heat source for the RTG are discussed.

Small Stirling dynamic isotope power system for multihundred-watt robotic missions

NASA Technical Reports Server (NTRS)

Bents, David J.

1991-01-01

Free Piston Stirling Engine (FPSE) and linear alternator (LA) technology is combined with radioisotope heat sources to produce a compact dynamic isotope power system (DIPS) suitable for multihundred watt space application which appears competitive with advance radioisotope thermoelectric generators (RTGs). The small Stirling DIPS is scalable to multihundred watt power levels or lower. The FPSE/LA is a high efficiency convertor in sizes ranging from tens of kilowatts down to only a few watts. At multihundred watt unit size, the FPSE can be directly integrated with the General Purpose Heat Source (GPHS) via radiative coupling; the resulting dynamic isotope power system has a size and weight that compares favorably with the advanced modular (Mod) RTG, but requires less than a third the amount of isotope fuel. Thus the FPSE extends the high efficiency advantage of dynamic systems into a power range never previously considered competitive for DIPS. This results in lower fuel cost and reduced radiological hazard per delivered electrical watt.

Small Stirling dynamic isotope power system for multihundred-watt robotic missions

NASA Technical Reports Server (NTRS)

Bents, David J.

1991-01-01

Free piston Stirling Engine (FPSE) and linear alternator (LA) technology is combined with radioisotope heat sources to produce a compact dynamic isotope power system (DIPS) suitable for multihundred watt space application which appears competitive with advanced radioisotope thermoelectric generators (RTGs). The small Stirling DIPS is scalable to multihundred watt power levels or lower. The FPSE/LA is a high efficiency convertor in sizes ranging from tens of kilowatts down to only a few watts. At multihundred watt unit size, the FPSE can be directly integrated with the General Purpose Heat Source (GPHS) via radiative coupling; the resulting dynamic isotope power system has a size and weight that compares favorably with the advanced modular (Mod) RTG, but requires less than a third the amount of isotope fuel. Thus the FPSE extends the high efficiency advantage of dynamic systems into a power range never previously considered competitive for DIPS. This results in lower fuel cost and reduced radiological hazard per delivered electrical watt.

Mutants of Saccharomyces Cerevisiae with Defects in Acetate Metabolism: Isolation and Characterization of Acn(-) Mutants

PubMed Central

McCammon, M. T.

1996-01-01

The two carbon compounds, ethanol and acetate, can be oxidatively metabolized as well as assimilated into carbohydrate in the yeast Saccharomyces cerevisiae. The distribution of acetate metabolic enzymes among several cellular compartments, mitochondria, peroxisomes, and cytoplasm makes it an intriguing system to study complex metabolic interactions. To investigate the complex process of carbon catabolism and assimilation, mutants unable to grow on acetate were isolated. One hundred five Acn(-) (``ACetate Nonutilizing'') mutants were sorted into 21 complementation groups with an additional 20 single mutants. Five of the groups have defects in TCA cycle enzymes: MDH1, CIT1, ACO1, IDH1, and IDH2. A defect in RTG2, involved in the retrograde communication between the mitochondrion and the nucleus, was also identified. Four genes encode enzymes of the glyoxylate cycle and gluconeogenesis: ICL1, MLS1, MDH2, and PCK1. Five other genes appear to be defective in regulating metabolic activity since elevated levels of enzymes in several metabolic pathways, including the glyoxylate cycle, gluconeogenesis, and acetyl-CoA metabolism, were detected in these mutants: ACN8, ACN9, ACN17, ACN18, and ACN42. In summary, this analysis has identified at least 22 and as many as 41 different genes involved in acetate metabolism. PMID:8878673

Effect of high fluence neutron irradiation on transport properties of thermoelectrics

NASA Astrophysics Data System (ADS)

Wang, H.; Leonard, K. J.

2017-07-01

Thermoelectric materials were subjected to high fluence neutron irradiation in order to understand the effect of radiation damage on transport properties. This study is relevant to the NASA Radioisotope Thermoelectric Generator (RTG) program in which thermoelectric elements are exposed to radiation over a long period of time in space missions. Selected n-type and p-type bismuth telluride materials were irradiated at the High Flux Isotope Reactor with a neutron fluence of 1.3 × 1018 n/cm2 (E > 0.1 MeV). The increase in the Seebeck coefficient in the n-type material was partially off-set by an increase in electrical resistivity, making the power factor higher at lower temperatures. For the p-type materials, although the Seebeck coefficient was not affected by irradiation, electrical resistivity decreased slightly. The figure of merit, zT, showed a clear drop in the 300-400 K range for the p-type material and an increase for the n-type material. Considering that the p-type and n-type materials are connected in series in a module, the overall irradiation damages at the device level were limited. These results, at neutron fluences exceeding a typical space mission, are significant to ensure that the radiation damage to thermoelectrics does not affect the performance of RTGs.

Low Intensity Low Temperature (LILT) measurements and coefficients on new photovoltaic structures

NASA Technical Reports Server (NTRS)

Schelman, David A.; Jenkins, Philip P.; Brinker, David J.; Appelbaum, Joseph

1995-01-01

Past NASA missions to Mars, Jupiter, and the outer planets were powered by radioisotope thermal generators (RTG's). Although these devices proved to be reliable, their high cost and highly toxic radioactive heat source has made them far less desirable for future planetary missions. This has resulted in a renewed search for alternate energy sources, some of them being photovoltaic (PV) and thermophotovoltaic (TPV). Both of these alternate energy sources convert light/thermal energy directly into electricity. In order to create a viable PV and TPV data base for planetary mission planners and cell designers, we have compiled low temperature low intensity (LILT) I-V data on single junction and multi-junction high efficiency solar cells. The cells tested here represent the latest photovoltaic technology. Using this LILT data to calculate dI(sub SC)/dT, dV(sub OC)/dT, dFF/dT, and also as a function of intensity, an accurate prediction of cell performance under the AMO spectrum can be determined. When combined with QUantum efficiency at Low Temperature (QULT) data, one can further enhance the data by adding spectral variations to the measurements. This paper presents an overview of LILT measurements and is only intended to be used as a guideline for material selection and performance predictions. As single junction and multi-junction cell technologies emerge, new test data must be collected. Cell materials included are Si, GaAs/Ge, GainP/GaAs/Ge, InP, InGaAs/InP, InP/InGaAs/InP, and GainP. Temperatures range as low as -175 C and intensities range from 1 sun to .02 suns.

Project ECHO: Electronic Communications from Halo Orbit

NASA Technical Reports Server (NTRS)

Borrelli, Jason; Cooley, Bryan; Debole, Marcy; Hrivnak, Lance; Nielsen, Kenneth; Sangmeister, Gary; Wolfe, Matthew

1994-01-01

The design of a communications relay to provide constant access between the Earth and the far side of the Moon is presented. Placement of the relay in a halo orbit about the L2 Earth-Moon Lagrange point allows the satellite to maintain constant simultaneous communication between Earth and scientific payloads on the far side of the Moon. The requirements of NASA's Discovery-class missions adopted and modified for this design are: total project cost should not exceed $150 million excluding launch costs, launch must be provided by Delta-class vehicle, and the satellite should maintain an operational lifetime of 10 to 15 years. The spacecraft will follow a transfer trajectory to the L2 point, after launch by a Delta II 7925 vehicle in 1999. Low-level thrust is used for injection into a stationkeeping-free halo orbit once the spacecraft reaches the L2 point. The shape of this halo orbit is highly elliptical with the maximum excursion from the L2 point being 35000 km. A spun section and despun section connected through a bearing and power transfer assembly (BAPTA) compose the structure of the spacecraft. Communications equipment is placed on the despun section to provide for a stationary dual parabolic offset-feed array antenna system. The dual system is necessary to provide communications coverage during portions of maximum excursion on the halo orbit. Transmissions to the NASA Deep Space Network 34 m antenna include six channels (color video, two voice, scientific data from lunar payloads, satellite housekeeping and telemetry and uplinked commands) using the S- and X-bands. Four radioisotope thermoelectric generators (RTG's) provide a total of 1360 W to power onboard systems and any two of the four Hughes 13 cm ion thrusters at once. Output of the ion thrusters is approximately 17.8 mN each with xenon as the propellant. Presence of torques generated by solar pressure on the antenna dish require the addition of a 'skirt' extending from the spun section of the satellite for balance. Total mass of the satellite is approximately 900 kg at a cost of $130 million FY99.

Evaluation of zinc oxide nanoparticle toxicity in sludge products applied to agricultural soil using multispecies soil systems.

PubMed

Fernández, María Dolores; Alonso-Blázquez, María Nieves; García-Gómez, Concepción; Babin, Mar

2014-11-01

To study the environmental impact of nanoparticles, the sludges of wastewater (WWTS) and water treatment (WTS) plants enriched with ZnO nanoparticles were added to agricultural soil, and the toxic effects of the nanoparticles were studied using a microcosm system based on the soil. The WWTS treated soils were characterised by statistically significant decreases (p<0.05) in Vicia sativa germination at the lowest (76.2%) and medium (95.2%) application rates, decreases in the fresh biomass for Triticum aestivum (19.5%), Raphanus sativus (64.1%), V. sativa (37.4%) and Eisenia fetida (33.6%) at the highest application rate and a dose-related significant increase (p<0.05) in earthworm mortality. In WTS amended soils, significant reductions (p<0.05) of the fresh biomass (17.2%) and the chlorophyll index (24.4%) for T. aestivum and the fresh biomass for R. sativus (31.4%) were only recorded at the highest application doses. In addition, the soil phosphatase enzymatic activity decreased significantly (p<0.05) in both WWTS (dose related) and WTS treatments. For water organisms, a slight inhibition of the growth of Chlorella vulgaris was observed (WWTS treated soils), along with statistically significant dose-related inhibition responses on total glutathione cell content, and statistically significant dose-related induction responses on the glutathione S-transferase enzyme activity and the reactive oxygen species generation on the RTG-2 fish cell line. Copyright © 2014 Elsevier B.V. All rights reserved.

Advanced Controller for the Free-Piston Stirling Convertor

NASA Technical Reports Server (NTRS)

Gerber, Scott S.; Jamison, Mike; Roth, Mary Ellen; Regan, Timothy F.

2004-01-01

The free-piston Stirling power convertor is being considered as an advanced power conversion technology to be used for future NASA deep space missions requiring long life radioisotope power systems. This technology has a conversion efficiency of over 25%, which is significantly higher than the efficiency of the Radioisotope Thermal-electric Generators (RTG) now in use. The NASA Glenn Research Center has long been recognized as a leader in Stirling technology and is responsible for the development of advanced technologies that are intended to significantly improve key characteristics of the Stirling convertor. The advanced technologies identified for development also consider the requirements of potential future missions and the new capabilities that have become available in the associated technical areas. One of the key areas identified for technology development is the engine controller. To support this activity, an advanced controller is being developed for the Stirling power convertor. This controller utilizes active power factor correction electronics and microcontroller-based controls. The object of this paper is to present an overview of the advanced controller concept with modeling, simulation and hardware test data.

Metallic Junction Thermoelectric Device Simulations

NASA Technical Reports Server (NTRS)

Duzik, Adam J.; Choi, Sang H.

2017-01-01

Thermoelectric junctions made of semiconductors have existed in radioisotope thermoelectric generators (RTG) for deep space missions, but are currently being adapted for terrestrial energy harvesting. Unfortunately, these devices are inefficient, operating at only 7% efficiency. This low efficiency has driven efforts to make high-figure-of-merit thermoelectric devices, which require a high electrical conductivity but a low thermal conductivity, a combination that is difficult to achieve. Lowered thermal conductivity has increased efficiency, but at the cost of power output. An alternative setup is to use metallic junctions rather than semiconductors as thermoelectric devices. Metals have orders of magnitude more electrons and electronic conductivities higher than semiconductors, but thermal conductivity is higher as well. To evaluate the viability of metallic junction thermoelectrics, a two dimensional heat transfer MATLAB simulation was constructed to calculate efficiency and power output. High Seebeck coefficient alloys, Chromel (90%Ni-10%Cr) and Constantan (55%Cu-45%Ni), produced efficiencies of around 20-30%. Parameters such as the number of layers of junctions, lateral junction density, and junction sizes for both series- and parallel-connected junctions were explored.

Hsp90 activator Aha1 drives production of pathological tau aggregates

PubMed Central

Shelton, Lindsey B.; Baker, Jeremy D.; Zheng, Dali; Sullivan, Leia E.; Solanki, Parth K.; Webster, Jack M.; Sun, Zheying; Sabbagh, Jonathan J.; Nordhues, Bryce A.; Koren, John; Ghosh, Suman; Blagg, Brian S. J.; Dickey, Chad A.

2017-01-01

The microtubule-associated protein tau (MAPT, tau) forms neurotoxic aggregates that promote cognitive deficits in tauopathies, the most common of which is Alzheimer’s disease (AD). The 90-kDa heat shock protein (Hsp90) chaperone system affects the accumulation of these toxic tau species, which can be modulated with Hsp90 inhibitors. However, many Hsp90 inhibitors are not blood–brain barrier-permeable, and several present associated toxicities. Here, we find that the cochaperone, activator of Hsp90 ATPase homolog 1 (Aha1), dramatically increased the production of aggregated tau. Treatment with an Aha1 inhibitor, KU-177, dramatically reduced the accumulation of insoluble tau. Aha1 colocalized with tau pathology in human brain tissue, and this association positively correlated with AD progression. Aha1 overexpression in the rTg4510 tau transgenic mouse model promoted insoluble and oligomeric tau accumulation leading to a physiological deficit in cognitive function. Overall, these data demonstrate that Aha1 contributes to tau fibril formation and neurotoxicity through Hsp90. This suggests that therapeutics targeting Aha1 may reduce toxic tau oligomers and slow or prevent neurodegenerative disease progression. PMID:28827321

Muscle function in aged women in response to a water-based exercises program and progressive resistance training.

PubMed

Bento, Paulo Cesar Barauce; Rodacki, André Luiz Felix

2015-11-01

The purpose of the present study was to determine the effects of a water-based exercise program on muscle function compared with regular high-intensity resistance training. Older women (n = 87) were recruited from the local community. The inclusion criteria were, to be aged 60 years or older, able to walk and able to carry out daily living activities independently. Participants were randomly assigned to one of the following groups: water-based exercises (WBG), resistance training (RTG) or control (CG). The experimental groups carried out 12 weeks of an excise program performed on water or on land. The dynamic strength, the isometric peak, and rate of torque development for the lower limbs were assessed before and after interventions. The water-based program provided a similar improvement in dynamic strength in comparison with resistance training. The isometric peak torque increased around the hip and ankle joints in the water-based group, and around the knee joint in the resistance-training group (P < 0.05). The rate of torque development increased only in the water-based group around the hip extensors muscles (P < 0.05). Water-based programs constitute an attractive alternative to promote relevant strength gains using moderate loads and fast speed movements, which were also effective to improve the capacity to generate fast torques. © 2014 Japan Geriatrics Society.

The Influence of Ocean on Typhoon Nuri (2008)

NASA Astrophysics Data System (ADS)

Sun, J.; Oey, L. Y.; Xu, F.; Lin, Y.; Huang, S. M.; Chang, R.

2014-12-01

The influence of ocean on typhoon Nuri (2008) is investigated in this study using the WRF numerical model. Typhoon Nuri formed over the warm pool of the western North Pacific. The storm traversed west-northwestward and became a Category 3 typhoon over the Kuroshio east of the Luzon Strait and weakened as it moved across South China Sea. Three types of SST: NCEP RTG_SST (Real-time，global，sea surface temperature) GHRsst (Group for High Resolution Sea Surface Temperature) and SST from the ATOP North Pacific ocean model [Oey et al 2014, JPO] are used in WRF to test the effect of ocean on the intensity of typhoon Nuri. The typhoon intensity and track are also compared with simulations using different microphysics schemes but with fixed SST. The results show that thermodynamic control through ocean response is the dominant factor which determines Nuri's intensity. The simulated intensity agrees well with the observed intensity when ATOP SST is used, while using NCEP SST and GHRsst yield errors both in intensity and timing of maximum intensity. Over the Kuroshio, the thicker depth of 26 ℃ from ATOP provides stronger heating for the correct timing of intensification of Nuri. In South China Sea, the storm weakened because of cooled SST through ocean mixing by inertial resonance. A new way of explaining typhoon intensification though PV is proposed.

Transduction of cultured fish cells with recombinant baculoviruses.

PubMed

Leisy, Douglas J; Lewis, Teresa D; Leong, Jo-Ann C; Rohrmann, George F

2003-05-01

Five fish cell lines were tested for their ability to be transduced by Ac-CAlacZ, a recombinant baculovirus that is capable of expressing a beta-galactosidase reporter gene from the CAG promoter (consisting of a cytomegalovirus enhancer element, a chicken actin promoter and rabbit beta-globin termination sequences). TO (Tilapia ovary), EPC (carp), CHH-1 (Chum salmon heart fibroblast) and CHSE-214 (chinook salmon embryo) cells were transducible, as demonstrated by an in situ beta-galactosidase assay, whereas RTG-2 (rainbow trout gonad) cells were not. The EPC cell line was used for more detailed studies on baculovirus transduction. The transduction frequency was found to be higher at 28 degrees C than at 21 degrees C. Addition of the histone deacetylase inhibitor sodium butyrate increased the number of blue cells detected 5- to 7-fold. The m.o.i. was positively correlated with transduction frequency, although the relationship did not appear to be strictly linear, as has been observed with mammalian cells. The temperature at which baculoviruses were adsorbed to EPC cells did not affect levels of beta-galactosidase expression. We also examined expression levels of beta-galactosidase in EPC cells after infection with a baculovirus construct that overexpresses the vesicular stomatitis virus G protein and displays it on the virion surface. Expression levels with this virus were approximately 15-fold higher than were observed with Ac-CAlacZ.

Quantitative Comparison of Dense-Core Amyloid Plaque Accumulation in Amyloid-β Protein Precursor Transgenic Mice.

PubMed

Liu, Peng; Reichl, John H; Rao, Eshaan R; McNellis, Brittany M; Huang, Eric S; Hemmy, Laura S; Forster, Colleen L; Kuskowski, Michael A; Borchelt, David R; Vassar, Robert; Ashe, Karen H; Zahs, Kathleen R

2017-01-01

There exist several dozen lines of transgenic mice that express human amyloid-β protein precursor (AβPP) with Alzheimer's disease (AD)-linked mutations. AβPP transgenic mouse lines differ in the types and amounts of Aβ that they generate and in their spatiotemporal patterns of expression of Aβ assemblies, providing a toolkit to study Aβ amyloidosis and the influence of Aβ aggregation on brain function. More complete quantitative descriptions of the types of Aβ assemblies present in transgenic mice and in humans during disease progression should add to our understanding of how Aβ toxicity in mice relates to the pathogenesis of AD. Here, we provide a direct quantitative comparison of amyloid plaque burdens and plaque sizes in four lines of AβPP transgenic mice. We measured the fraction of cortex and hippocampus occupied by dense-core plaques, visualized by staining with Thioflavin S, in mice from young adulthood through advanced age. We found that the plaque burdens among the transgenic lines varied by an order of magnitude: at 15 months of age, the oldest age studied, the median cortical plaque burden in 5XFAD mice was already ∼4.5 times that of 21-month-old Tg2576 mice and ∼15 times that of 21-24-month-old rTg9191 mice. Plaque-size distributions changed across the lifespan in a line- and region-dependent manner. We also compared the dense-core plaque burdens in the mice to those measured in a set of pathologically-confirmed AD cases from the Nun Study. Cortical plaque burdens in Tg2576, APPSwePS1ΔE9, and 5XFAD mice eventually far exceeded those measured in the human cohort.

Quantitative Comparison of Dense-Core Amyloid Plaque Accumulation in Amyloid-β Precursor Protein Transgenic Mice

PubMed Central

Liu, Peng; Reichl, John H.; Rao, Eshaan R.; McNellis, Brittany M.; Huang, Eric S.; Hemmy, Laura S.; Forster, Colleen L.; Kuskowski, Michael A.; Borchelt, David R.; Vassar, Robert; Ashe, Karen H.; Zahs, Kathleen R.

2016-01-01

There exist several dozen lines of transgenic mice that express human amyloid-β precursor protein (AβPP) with Alzheimer’s disease (AD)-linked mutations. AβPP transgenic mouse lines differ in the types and amounts of Aβ that they generate and in their spatiotemporal patterns of expression of Aβ assemblies, providing a toolkit to study Aβ amyloidosis and the influence of Aβ aggregation on brain function. More complete quantitative descriptions of the types of Aβ assemblies present in transgenic mice and in humans during disease progression should add to our understanding of how Aβ toxicity in mice relates to the pathogenesis of AD. Here, we provide a direct quantitative comparison of amyloid plaque burdens and plaque sizes in four lines of AβPP transgenic mice. We measured the fraction of cortex and hippocampus occupied by dense-core plaques, visualized by staining with Thioflavin S, in mice from young adulthood through advanced age. We found that the plaque burdens among the transgenic lines varied by an order of magnitude: at 15 months of age, the oldest age studied, the median cortical plaque burden in 5XFAD mice was already ~4.5 times that of 21-month Tg2576 mice and ~15 times that of 21–24-month rTg9191 mice. Plaque-size distributions changed across the lifespan in a line- and region-dependent manner. We also compared the dense-core plaque burdens in the mice to those measured in a set of pathologically-confirmed AD cases from the Nun Study. Cortical plaque burdens in Tg2576, APPSwePS1ΔE9, and 5XFAD mice eventually far exceeded those measured in the human cohort. PMID:28059792

Using a transportable optical clock for chronometric levelling

NASA Astrophysics Data System (ADS)

Lisdat, Christian; Sterr, Uwe; Koller, Silvio; Grotti, Jacopo; Vogt, Stefan; Häfner, Sebastian; Herbers, Sofia; Al-Masoudi, Ali

2016-07-01

With their supreme accuracy and precision, optical clocks in combination with new methods of long-distance frequency transfer can be used to determine height differences by measuring the gravitational red shift between two clocks without accumulation of measurement errors, as in classical levelling. We are developing transportable optical clocks for this purpose that will also serve for the technology development regarding optical clocks in Space and for international comparisons between optical clocks that cannot be linked with sufficient accuracy otherwise. In this talk we will focus on the transportable strontium lattice clock that we are developing and its first evaluation. Presently, we achieve a fractional frequency instability of 3 × 10^{-17} after 1000 s averaging time, which is equivalent to a height resolution of 30 cm. The first uncertainty evaluation of the system yielded 7 × 10^{-17}. We expect rapid improvements to an uncertainty of a few parts in 10^{17}. The clock is now located within a car trailer, which requires compact and rugged lasers systems and physics package. Special care has been taken in the design of the ultra-frequency stable interrogation laser that has to achieve fractional frequency instabilities of considerably below 10^{-15}. Typical laboratory constructions of the reference resonator system used to pre-stabilize the laser frequency are not compatible with the requirement of transportability. In an actual levelling campaign, this clock will be connected via a stabilized optical fibre link with another, stationary frequency standard. The measured gravitational red shift will be compared with the ones calculated from potential differences derived with state of the art geodetic data and models. We will discuss the status of measurements of geodetic relevance with optical clocks and give an outlook on our next steps. This work is supported by QUEST, DFG (RTG 1729, CRC 1128), EU-FP7 (FACT) and EMRP (ITOC). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.

Preparing for Operational Use of High Priority Products from the Joint Polar Satellite System (JPSS) in Numerical Weather Prediction

NASA Astrophysics Data System (ADS)

Nandi, S.; Layns, A. L.; Goldberg, M.; Gambacorta, A.; Ling, Y.; Collard, A.; Grumbine, R. W.; Sapper, J.; Ignatov, A.; Yoe, J. G.

2017-12-01

This work describes end to end operational implementation of high priority products from National Oceanic and Atmospheric Administration's (NOAA) operational polar-orbiting satellite constellation, to include Suomi National Polar-orbiting Partnership (S-NPP) and the Joint Polar Satellite System series initial satellite (JPSS-1), into numerical weather prediction and earth systems models. Development and evaluation needed for the initial implementations of VIIRS Environmental Data Records (EDR) for Sea Surface Temperature ingestion in the Real-Time Global Sea Surface Temperature Analysis (RTG) and Polar Winds assimilated in the National Weather Service (NWS) Global Forecast System (GFS) is presented. These implementations ensure continuity of data in these models in the event of loss of legacy sensor data. Also discussed is accelerated operational implementation of Advanced Technology Microwave Sounder (ATMS) Temperature Data Records (TDR) and Cross-track Infrared Sounder (CrIS) Sensor Data Records, identified as Key Performance Parameters by the National Weather Service. Operational use of SNPP after 28 October, 2011 launch took more than one year due to the learning curve and development needed for full exploitation of new remote sensing capabilities. Today, ATMS and CrIS data positively impact weather forecast accuracy. For NOAA's JPSS initial satellite (JPSS-1), scheduled for launch in late 2017, we identify scope and timelines for pre-launch and post-launch activities needed to efficiently transition these capabilities into operations. As part of these alignment efforts, operational readiness for KPPs will be possible as soon as 90 days after launch. The schedule acceleration is possible because of the experience with S-NPP. NOAA operational polar-orbiting satellite constellation provides continuity and enhancement of earth systems observations out to 2036. Program best practices and lessons learned will inform future implementation for follow-on JPSS-3 and -4 missions ensuring benefits and enhancements during the system's design life.

Operational Readiness Review Plan for the Radioisotope Thermoelectric Generator Materials Production Tasks

DOE R&D Accomplishments Database

Cooper, R. H.; Martin, M. M.; Riggs, C. R.; Beatty, R. L.; Ohriner, E. K.; Escher, R. N.

1990-04-19

In October 1989, a US shuttle lifted off from Cape Kennedy carrying the spacecraft Galileo on its mission to Jupiter. In November 1990, a second spacecraft, Ulysses, will be launched from Cape Kennedy with a mission to study the polar regions of the sun. The prime source of power for both spacecraft is a series of radioisotope thermoelectric generators (RTGs), which use plutonium oxide (plutonia) as a heat source. Several of the key components in this power system are required to ensure the safety of both the public and the environment and were manufactured at Oak Ridge National Laboratory (ORNL) in the 1980 to 1983 period. For these two missions, Martin Marietta Energy Systems, Inc. (Energy Systems), will provide an iridium alloy component used to contain the plutonia heat source and a carbon composite material that serves as a thermal insulator. ORNL alone will continue to fabricate the carbon composite material. Because of the importance to DOE that Energy Systems deliver these high quality components on time, performance of an Operational Readiness Review (ORR) of these manufacturing activities is necessary. Energy Systems Policy GP 24 entitled "Operational Readiness Process" describes the formal and comprehensive process by which appropriate Energy Systems activities are to be reviewed to ensure their readiness. This Energy System policy is aimed at reducing the risks associated with mission success and requires a management approved "readiness plan" to be issued. This document is the readiness plan for the RTG materials production tasks.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yokoo, Masako; Fujita, Ryosuke; Innate Immunity Laboratory, Graduate School of Life Science and Creative Research Institution, Hokkaido University, Sapporo 001-0021

Highlights: •The baculovirus vector infiltrates the cells of economic important fishes. •Drosophila Mos1 transposase expressed in fish cells maintains its ability to localize to the nucleus. •The baculoviral vector carrying Mos1 is a useful tool to stably transform fish cells. -- Abstract: Drosophila Mos1 belongs to the mariner family of transposons, which are one of the most ubiquitous transposons among eukaryotes. We first determined nuclear transportation of the Drosophila Mos1-EGFP fusion protein in fish cell lines because it is required for a function of transposons. We next constructed recombinant baculoviral vectors harboring the Drosophila Mos1 transposon or marker genes locatedmore » between Mos1 inverted repeats. The infectivity of the recombinant virus to fish cells was assessed by monitoring the expression of a fluorescent protein encoded in the viral genome. We detected transgene expression in CHSE-214, HINAE, and EPC cells, but not in GF or RTG-2 cells. In the co-infection assay of the Mos1-expressing virus and reporter gene-expressing virus, we successfully transformed CHSE-214 and HINAE cells. These results suggest that the combination of a baculovirus and Mos1 transposable element may be a tool for transgenesis in fish cells.« less

AIRS Science Accomplishments Version 4.0/Plans for Version 5

NASA Technical Reports Server (NTRS)

Pagano, Thomas S.; Aumann, Hartmut; Elliott, Denis; Granger, Stephanie; Kahn, Brain; Eldering, Annmarie; Irion, Bill; Fetzer, Eric; Olsen, Ed; Lee, Sung-Yung;

General-Purpose Heat Source Safety Verification Test Program: Edge-on flyer plate tests

NASA Astrophysics Data System (ADS)

George, T. G.

1987-03-01

The radioisotope thermoelectric generator (RTG) that will supply power for the Galileo and Ulysses space missions contains 18 General-Purpose Heat Source (GPHS) modules. The GPHS modules provide power by transmitting the heat of Pu-238 alpha-decay to an array of thermoelectric elements. Each module contains four Pu-238O2-fueled clads and generates 250 W(t). Because the possibility of a launch vehicle explosion always exists, and because such an explosion could generate a field of high-energy fragments, the fueled clads within each GPHS module must survive fragment impact. The edge-on flyer plate tests were included in the Safety Verification Test series to provide information on the module/clad response to the impact of high-energy plate fragments. The test results indicate that the edge-on impact of a 3.2-mm-thick, aluminum-alloy (2219-T87) plate traveling at 915 m/s causes the complete release of fuel from capsules contained within a bare GPHS module, and that the threshold velocity sufficient to cause the breach of a bare, simulant-fueled clad impacted by a 3.5-mm-thick, aluminum-alloy (5052-TO) plate is approximately 140 m/s.

NASA/DOD Aerospace Knowledge Diffusion Research Project. Report No. 36: The Technical Communications Practices of US Aerospace Engineers and Scientists: Results of the Phase 1 NASA Langley Research Center Mail Survey

NASA Technical Reports Server (NTRS)

Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M.

1995-01-01

The U.S. government technical report is a primary means by which the results of federally funded research and development (R&D) are transferred to the U.S. aerospace industry. However, little is known about this information product in terms of its actual use, importance, and value in the transfer of federally funded R&D. To help establish a body of knowledge, the U.S. government technical report is being investigated as part of the NASA/DOD Aerospace Knowledge Diffusion Research Project. In this report, we summarize the literature on technical reports and provide a model that depicts the transfer of federally funded aerospace R&D via the U.S. government technical report. We present results from our investigation of aerospace knowledge diffusion vis-a-vis the U.S. government technical report, and present the results of research that investigated aerospace knowledge diffusion vis-a-vis the technical communications practices of U.S. aerospace engineers and scientists who were assigned to the Research and Technology Group (RTG) at the NASA Langley Research Center in September 1995.

Dynamic Radioisotope Power System Development for Space Explorations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qualls, A L

Dynamic power conversion offers the potential to produce radioisotope power systems (RPS) that generate higher power outputs and utilize the Pu-238 radioisotope more efficiently than Radioisotope Thermoelectric Generators (RTG). Additionally, dynamic systems also offer the potential of producing generators with significantly reduced power degradation over the course of deep space missions so that more power will be available at the end of the mission when it is needed for both powering the science and transmitting the results. The development of dynamic generators involves addressing technical issues not typically associated with traditional thermoelectric generators. Developing long-life, robust and reliable dynamic conversionmore » technology is challenging yet essential to building a suitable generator. Considerations include working within existing handling infrastructure where possible so that development costs can be kept low and integrating dynamic generators into spacecraft, which may be more complex than integration of static systems. Methods of interfacing to and controlling a dynamic generator must be considered and new potential failure modes must be taken into account. This paper will address some of the key issues of dynamic RPS design, development and adaption.Dynamic power conversion offers the potential to produce Radioisotope Power Systems (RPS) that generate higher power outputs and utilize the available heat source plutonium fuel more efficiently than Radioisotope Thermoelectric Generators. Additionally, dynamic systems offer the potential of producing generators with significantly reduced power degradation over the course of deep space missions so that more power would be available at the end of the mission, when it is needed most for both powering science instruments and transmitting the resulting data. The development of dynamic generators involves addressing technical issues not typically associated with traditional thermoelectric generators. Developing long-life, robust, and reliable dynamic conversion technology is challenging yet essential to building a suitable flight-ready generator. Considerations include working within existing hardware-handling infrastructure, where possible, so that development costs can be kept low, and integrating dynamic generators into spacecraft, which may be more complex than integration of static thermoelectric systems. Methods of interfacing to and controlling a dynamic generator must also be considered, and new potential failure modes must be taken into account. This paper will address some of the key issues of dynamic RPS design, development, and adaption.« less

A Nature of Gravitation and the Problem of the Laboratory Gravitational Waves Generation

NASA Astrophysics Data System (ADS)

Kanibolotsky, Valentyn

2010-01-01

This work sheds light on nature of gravitation and vacuum structure to offer new possibilities for the laboratory HFGWs generation, since neither Einstein's GR nor any another theory of gravity not make answer on this question. Well-known hypothesis about non-materiality of gravitation field unambiguously leads to representation that the elemental particles (EPs) are gravitational stabilized substance. By their nature EPs would constitute microscopic black holes with extreme curved space-time into their bulk and in the vicinity. Since EPs birth take place at interaction of photons with polarized vacuum, this latter represents medium consisting from massless gravitational skeletons of known EPs. So the particle can be not born without its antiparticle and vacuum is gravitationally neutral, particle and antiparticle skeleton, must possess gravitation and antigravitation, correspondingly. GWs would be represented oscillations of the EPs gravitational and antigravitational skeletons around the common centre and in consequence they would be transverse. The high penetrating ability of GWs is a result that neither vacuum, in which HFGWs are propagated, nor HFGWs, does not have mass (energy). In the concept frameworks a new RTG, which must be confirmed these representations, is developed. However, already the fact by itself the laboratory generation of GWs is the direct proof of correctness of these representations.

Coccygodynia - pathogenesis, diagnostics and therapy. Review of the writing.

PubMed

Dampc, Bogumiła; Słowiński, Krzysztof

2017-08-31

Coccygodynia is a problem with a small percentage (1%) of the population suffering from musculoskeletal disorders. This pain is often associated with trauma, falling on the tailbone, long cycling, or by women after childbirth. The reason for the described problem can be the actual morphological changes. Idiopathic coccygodynia causes therapeutic difficulties to specialists of many fields. Unsatisfactory treatment, including coccygectomy tends to seek new solutions. They belong to them techniques exploited in the manual therapy which in their spectrum hold: direct techniques - per rectum as well as indirect techniques taking into account distant structures of the motor organ, remaining in dense interactions with the coccygeal part. Idiopathic coccygodynia is a result perhaps from exaggerated tension the muscle of the levator ani, coccygeus and gluteus maximus as well as from irritating soft tissue structures surrounding the coccyx: of sacrococcygeum, sacrospinale, and sacrotuberale ligament. Unfortunately we can't see them in objective examinations so as: the RTG, MR or TK, therefore constitute the both diagnostic and therapeutic problem. For describing the problem a writing of the object was used both from the field of the surgery and of manual therapy. Detailed and multifaceted knowledge about causes of the described problem allows more accurately to categorize the patient to the appropriate group and helps to select the best procedure of treatment.

Spectral Cloud-Filtering of AIRS Data: Non-Polar Ocean

NASA Technical Reports Server (NTRS)

Aumann, Hartmut H.; Gregorich, David; Barron, Diana

2004-01-01

The Atmospheric Infrared Sounder (AIRS) is a grating array spectrometer which covers the thermal infrared spectral range between 640 and 1700/cm. In order to retain the maximum radiometric accuracy of the AIRS data, the effects of cloud contamination have to be minimized. We discuss cloud filtering which uses the high spectral resolution of AIRS to identify about 100,000 of 500,000 non-polar ocean spectra per day as relatively "cloud-free". Based on the comparison of surface channels with the NCEP provided global real time sst (rtg.sst), AIRS surface sensitive channels have a cold bias ranging from O.5K during the day to 0.8K during the night. Day and night spatial coherence tests show that the cold bias is due to cloud contamination. During the day the cloud contamination is due to a 2-3% broken cloud cover at the 1-2 km altitude, characteristic of low stratus clouds. The cloud-contamination effects surface sensitive channels only. Cloud contamination can be reduced to 0.2K by combining the spectral filter with a spatial coherence threshold, but the yield drops to 16,000 spectra per day. AIRS was launched in May 2002 on the Earth Observing System (EOS) Aqua satellite. Since September 2002 it has returned 4 million spectra of the globe each day.

Draft environmental impact statement for the Galileo Mission (Tier 2)

NASA Technical Reports Server (NTRS)

1988-01-01

This Draft Environmental Impact Statement (DEIS) addresses the environmental impacts which may be caused by the preparation and operation of the Galileo spacecraft, including its planned launch on the Space Transportation System (STS) Shuttle and the alternative of canceling further work on the mission. The launch configuration will use the STS/Inertial Upper Stage (IUS)/Payload Assist Module-Special (PAM-S) combination. The Tier 1 EIS included a delay alternative which considered the Titan 4 launch vehicle as an alternative booster stage for launch in 1991 or later. However, the U.S. Air Force, which procures the Titan 4 for NASA, could not provide a Titan 4 vehicle for the 1991 launch opportunity because of high priority Department of Defense requirements. The only expected environmental effects of the proposed action are associated with normal Shuttle launch operations. These impacts are limited largely to the near-field at the launch pad, except for temporary stratospheric ozone effects during launch and occasional sonic boom effects near the landing site. These effects have been judged insufficient to preclude Shuttle launches. In the event of: (1) an accident during launch, or (2) reentry of the spacecraft from earth orbit, there are potential adverse health and environmental effects associated with the possible release of plutonium dioxide from the spacecraft's radioisotope thermoelectric generators (RTG).

Outbreak of infectious pancreatic necrosis virus (IPNV) in farmed rainbow trout in China.

PubMed

Zhu, Ling; Wang, Xingli; Wang, Kaiyu; Yang, Qian; He, Jie; Qin, Zhenyang; Geng, Yi; Ouyang, Ping; Huang, Xiaoli

2017-06-01

Infectious pancreatic necrosis virus (IPNV) is a member of the Aquabirnavirus genus, which caused mass mortality (nearly 100%) in farmed rainbow trout (Oncorhynchus mykiss) in aquaculture farms in 2016, China. Major clinical signs included decreased appetite, mucous-like stools, and darkened pigmentation. Pathological changes in moribund fish were observed, such as marked vacuolar degeneration of the pancreatic cells with pyknotic nucleus and decreased zymogen granules, severe hemorrhage in the liver, and tumidness of respiratory epithelium in gills. In addition, the tissue fluid of diseased fish could produce a cytopathic effect (CPE) in RTG-2 cells. The presence of specific 206bp fragments by the reverse transcription-polymerase chain reaction (RT-PCR) using tissue homogenate of diseased fish and supernatant of infected cells revealed that IPNV could be confirmed. The pathogenicity test of cell culture supernatant detected cumulative mortality of 80%, and the clinical symptoms observed in the moribund and dead fish were similar to the naturally infected fish. Furthermore, the sequence analysis of VP2 gene showed that the isolated virus strain belonged to genogroup 1, and 97% homology with the Mexican IPNV isolate was found. To our knowledge, this is the first report on IPNV natural infection in the southwest of China. Copyright © 2017 Elsevier B.V. All rights reserved.

Isometric immersions and self-similar buckling in elastic sheets.

NASA Astrophysics Data System (ADS)

Gemmer, John

The edges of torn elastic sheets and growing leaves often display hierarchical self-similar like buckling patterns. On the one hand, such complex, self similar patterns are usually associated with a competition between two distinct energy scales, e.g. elastic sheets with boundary conditions that preclude the possibility of relieving in plane strains, or at alloy-alloy interfaces between distinct crystal structures. On the other hand, within the non-Euclidean plate theory this complex morphology can be understood as low bending energy isometric immersions of hyperbolic Riemannian metrics. In particular, many growth patterns generate residual in-plane strains which can be entirely relieved by the sheet forming part of a surface of revolution or a helix. In this talk we will show that this complex morphology (i) arises from isometric immersions (ii) is driven by a competition between the two principal curvatures, rather than between bending and stretching. We identify the key role of branch-point (or monkey-saddle) singularities, in complex wrinkling patterns within the class of finite bending energy isometric immersions. Using these defects we will give an explicit construction of strain-free embeddings of hyperbolic surfaces that are fractal like and have lower elastic energy than their smooth counterparts US-Israel BSF Grant 2008432. NSF Grant DMS-0807501. NSF-RTG Grant DMS-1148284.

Utilizing Radioisotope Power System Waste Heat for Spacecraft Thermal Management

NASA Technical Reports Server (NTRS)

Pantano, David R.; Dottore, Frank; Tobery, E. Wayne; Geng, Steven M.; Schreiber, Jeffrey G.; Palko, Joseph L.

2005-01-01

An advantage of using a Radioisotope Power System (RPS) for deep space or planetary surface missions is the readily available waste heat, which can be used for a number of beneficial purposes including: maintaining electronic components within a controlled temperature range, warming propulsion tanks and mobility actuators, and maintaining liquid propellants above their freezing temperature. Previous missions using Radioisotope Thermoelectric Generators (RTGs) dissipated large quantities of waste heat due to the low efficiency of the thermoelectric conversion technology. The next generation RPSs, such as the 110-Watt Stirling Radioisotope Generator (SRG110) will have higher conversion efficiencies, thereby rejecting less waste heat at a lower temperature and may require alternate approaches to transferring waste heat to the spacecraft. RTGs, with efficiencies of 6 to 7 percent, reject their waste heat at the relatively high heat rejection temperature of 200 C. This is an advantage when rejecting heat to space; however, transferring heat to the internal spacecraft components requires a large and heavy radiator heat exchanger. At the same time, sensitive spacecraft instruments must be shielded from the thermal radiation of the RTG. The SRG110, with an efficiency around 22 percent and 50 C nominal housing surface temperature, can readily transfer the available waste heat directly via heat pipes, thermal straps, or fluid loops. The lower temperatures associated with the SRG110 avoid the chances of overheating other scientific components, eliminating the need for thermal shields. This provides the spacecraft designers more flexibility when locating the generator for a specific mission. A common misconception with high-efficiency systems is that there is not enough waste heat for spacecraft thermal management. This paper will dispel this misconception and investigate the use of a high-efficiency SRG110 for spacecraft thermal management and outline potential methods of waste heat utilization in several conceptual missions (Lunar Rover, Mars Rover, and Titan Lander). The advantages associated with the SRG110 as they relate to ease of assembly, less complex interfaces, and overall mass savings for a spacecraft will be highlighted.

Genome-scale analyses of butanol tolerance in Saccharomyces cerevisiae reveal an essential role of protein degradation

PubMed Central

2013-01-01

Background n-Butanol and isobutanol produced from biomass-derived sugars are promising renewable transport fuels and solvents. Saccharomyces cerevisiae has been engineered for butanol production, but its high butanol sensitivity poses an upper limit to product titers that can be reached by further pathway engineering. A better understanding of the molecular basis of butanol stress and tolerance of S. cerevisiae is important for achieving improved tolerance. Results By combining a screening of the haploid S. cerevisiae knock-out library, gene overexpression, and genome analysis of evolutionary engineered n-butanol-tolerant strains, we established that protein degradation plays an essential role in tolerance. Strains deleted in genes involved in the ubiquitin-proteasome system and in vacuolar degradation of damaged proteins showed hypersensitivity to n-butanol. Overexpression of YLR224W, encoding the subunit responsible for the recognition of damaged proteins of an ubiquitin ligase complex, resulted in a strain with a higher n-butanol tolerance. Two independently evolved n-butanol-tolerant strains carried different mutations in both RPN4 and RTG1, which encode transcription factors involved in the expression of proteasome and peroxisomal genes, respectively. Introduction of these mutated alleles in the reference strain increased butanol tolerance, confirming their relevance in the higher tolerance phenotype. The evolved strains, in addition to n-butanol, were also more tolerant to 2-butanol, isobutanol and 1-propanol, indicating a common molecular basis for sensitivity and tolerance to C3 and C4 alcohols. Conclusions This study shows that maintenance of protein integrity plays an essential role in butanol tolerance and demonstrates new promising targets to engineer S. cerevisiae for improved tolerance. PMID:23552365

Urban planning and agriculture. Methodology for assessing rooftop greenhouse potential of non-residential areas using airborne sensors.

PubMed

Nadal, Ana; Alamús, Ramón; Pipia, Luca; Ruiz, Antonio; Corbera, Jordi; Cuerva, Eva; Rieradevall, Joan; Josa, Alejandro

2017-12-01

The integration of rooftop greenhouses (RTGs) in urban buildings is a practice that is becoming increasingly important in the world for their contribution to food security and sustainable development. However, the supply of tools and procedures to facilitate their implementation at the city scale is limited and laborious. This work aims to develop a specific and automated methodology for identifying the feasibility of implementation of rooftop greenhouses in non-residential urban areas, using airborne sensors. The use of Light Detection and Ranging (LIDAR) and Long Wave Infrared (LWIR) data and the Leica ALS50-II and TASI-600 sensors allow for the identification of some building roof parameters (area, slope, materials, and solar radiation) to determine the potential for constructing a RTG. This development represents an improvement in time and accuracy with respect to previous methodology, where all the relevant information must be acquired manually. The methodology has been applied and validated in a case study corresponding to a non-residential urban area in the industrial municipality of Rubí, Barcelona (Spain). Based on this practical application, an area of 36,312m 2 out of a total area of 1,243,540m 2 of roofs with ideal characteristics for the construction of RTGs was identified. This area can produce approximately 600tons of tomatoes per year, which represents the average yearly consumption for about 50% of Rubí total population. The use of this methodology also facilitates the decision making process in urban agriculture, allowing a quick identification of optimal surfaces for the future implementation of urban agriculture in housing. It also opens new avenues for the use of airborne technology in environmental topics in cities. Copyright © 2017 Elsevier B.V. All rights reserved.

In-Situ Growth of Yb2O3 Layer for Sublimation Suppression for Yb14MnSb11 Thermoelectric Material for Space Power Applications

NASA Technical Reports Server (NTRS)

Nesbitt, James A.; Opila, Elizabeth J.; Nathal, Michael V.

2012-01-01

The compound Yb14MnSb11 is a p-type thermoelectric material of interest to the National Aeronautics and Space Administration (NASA) as a candidate replacement for the state-of-the-art Si-Ge used in current radioisotope thermoelectric generators (RTGs). Ideally, the hot end of this leg would operate at 1000 C in the vacuum of space. Although Yb14MnSb11 shows the potential to double the value of the thermoelectric figure of merit (zT) over that of Si-Ge at 1000 C, it suffers from a high sublimation rate at elevated temperatures and would require a coating in order to survive the required RTG lifetime of 14 years. The purpose of the present work is to measure the sublimation rate of Yb14MnSb11 and to investigate sublimation suppression for this material. This paper reports on the sublimation rate of Yb14MnSb11 at 1000 C (approximately 3 x 10(exp -3) grams per square centimeter hour) and efforts to reduce the sublimation rate with an in situ grown Yb2O3 layer. Despite the success in forming thin, dense, continuous, and adherent oxide scales on Yb14MnSb11, the scales did not prove to be sublimation barriers.

Screening with an NMNAT2-MSD platform identifies small molecules that modulate NMNAT2 levels in cortical neurons.

PubMed

Ali, Yousuf O; Bradley, Gillian; Lu, Hui-Chen

2017-03-07

Nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2) is a key neuronal maintenance factor and provides potent neuroprotection in numerous preclinical models of neurological disorders. NMNAT2 is significantly reduced in Alzheimer's, Huntington's, Parkinson's diseases. Here we developed a Meso Scale Discovery (MSD)-based screening platform to quantify endogenous NMNAT2 in cortical neurons. The high sensitivity and large dynamic range of this NMNAT2-MSD platform allowed us to screen the Sigma LOPAC library consisting of 1280 compounds. This library had a 2.89% hit rate, with 24 NMNAT2 positive and 13 negative modulators identified. Western analysis was conducted to validate and determine the dose-dependency of identified modulators. Caffeine, one identified NMNAT2 positive-modulator, when systemically administered restored NMNAT2 expression in rTg4510 tauopathy mice to normal levels. We confirmed in a cell culture model that four selected positive-modulators exerted NMNAT2-specific neuroprotection against vincristine-induced cell death while four selected NMNAT2 negative modulators reduced neuronal viability in an NMNAT2-dependent manner. Many of the identified NMNAT2 positive modulators are predicted to increase cAMP concentration, suggesting that neuronal NMNAT2 levels are tightly regulated by cAMP signaling. Taken together, our findings indicate that the NMNAT2-MSD platform provides a sensitive phenotypic screen to detect NMNAT2 in neurons.

Screening with an NMNAT2-MSD platform identifies small molecules that modulate NMNAT2 levels in cortical neurons

PubMed Central

Ali, Yousuf O.; Bradley, Gillian; Lu, Hui-Chen

2017-01-01

Nicotinamide mononucleotide adenylyl transferase 2 (NMNAT2) is a key neuronal maintenance factor and provides potent neuroprotection in numerous preclinical models of neurological disorders. NMNAT2 is significantly reduced in Alzheimer’s, Huntington’s, Parkinson’s diseases. Here we developed a Meso Scale Discovery (MSD)-based screening platform to quantify endogenous NMNAT2 in cortical neurons. The high sensitivity and large dynamic range of this NMNAT2-MSD platform allowed us to screen the Sigma LOPAC library consisting of 1280 compounds. This library had a 2.89% hit rate, with 24 NMNAT2 positive and 13 negative modulators identified. Western analysis was conducted to validate and determine the dose-dependency of identified modulators. Caffeine, one identified NMNAT2 positive-modulator, when systemically administered restored NMNAT2 expression in rTg4510 tauopathy mice to normal levels. We confirmed in a cell culture model that four selected positive-modulators exerted NMNAT2-specific neuroprotection against vincristine-induced cell death while four selected NMNAT2 negative modulators reduced neuronal viability in an NMNAT2-dependent manner. Many of the identified NMNAT2 positive modulators are predicted to increase cAMP concentration, suggesting that neuronal NMNAT2 levels are tightly regulated by cAMP signaling. Taken together, our findings indicate that the NMNAT2-MSD platform provides a sensitive phenotypic screen to detect NMNAT2 in neurons. PMID:28266613

Effect of high fluence neutron irradiation on transport properties of thermoelectrics

DOE PAGES

Wang, H.; Leonard, K. J.

2017-07-25

Thermoelectric materials were subjected to high fluence neutron irradiation in order to understand the effect of radiation damage on transport properties. This paper is relevant to the NASA Radioisotope Thermoelectric Generator (RTG) program in which thermoelectric elements are exposed to radiation over a long period of time in space missions. Selected n-type and p-type bismuth telluride materials were irradiated at the High Flux Isotope Reactor with a neutron fluence of 1.3 × 10 18 n/cm 2 (E > 0.1 MeV). The increase in the Seebeck coefficient in the n-type material was partially off-set by an increase in electrical resistivity, makingmore » the power factor higher at lower temperatures. For the p-type materials, although the Seebeck coefficient was not affected by irradiation, electrical resistivity decreased slightly. The figure of merit, zT, showed a clear drop in the 300–400 K range for the p-type material and an increase for the n-type material. Considering that the p-type and n-type materials are connected in series in a module, the overall irradiation damages at the device level were limited. Finally, these results, at neutron fluences exceeding a typical space mission, are significant to ensure that the radiation damage to thermoelectrics does not affect the performance of RTGs.« less

Effect of high fluence neutron irradiation on transport properties of thermoelectrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, H.; Leonard, K. J.

Thermoelectric materials were subjected to high fluence neutron irradiation in order to understand the effect of radiation damage on transport properties. This paper is relevant to the NASA Radioisotope Thermoelectric Generator (RTG) program in which thermoelectric elements are exposed to radiation over a long period of time in space missions. Selected n-type and p-type bismuth telluride materials were irradiated at the High Flux Isotope Reactor with a neutron fluence of 1.3 × 10 18 n/cm 2 (E > 0.1 MeV). The increase in the Seebeck coefficient in the n-type material was partially off-set by an increase in electrical resistivity, makingmore » the power factor higher at lower temperatures. For the p-type materials, although the Seebeck coefficient was not affected by irradiation, electrical resistivity decreased slightly. The figure of merit, zT, showed a clear drop in the 300–400 K range for the p-type material and an increase for the n-type material. Considering that the p-type and n-type materials are connected in series in a module, the overall irradiation damages at the device level were limited. Finally, these results, at neutron fluences exceeding a typical space mission, are significant to ensure that the radiation damage to thermoelectrics does not affect the performance of RTGs.« less

Mitochondrial Superoxide Dismutase and Yap1p Act as a Signaling Module Contributing to Ethanol Tolerance of the Yeast Saccharomyces cerevisiae.

PubMed

Zyrina, Anna N; Smirnova, Ekaterina A; Markova, Olga V; Severin, Fedor F; Knorre, Dmitry A

2017-02-01

There are two superoxide dismutases in the yeast Saccharomyces cerevisiae-cytoplasmic and mitochondrial enzymes. Inactivation of the cytoplasmic enzyme, Sod1p, renders the cells sensitive to a variety of stresses, while inactivation of the mitochondrial isoform, Sod2p, typically has a weaker effect. One exception is ethanol-induced stress. Here we studied the role of Sod2p in ethanol tolerance of yeast. First, we found that repression of SOD2 prevents ethanol-induced relocalization of yeast hydrogen peroxide-sensing transcription factor Yap1p, one of the key stress resistance proteins. In agreement with this, the levels of Trx2p and Gsh1p, proteins encoded by Yap1 target genes, were decreased in the absence of Sod2p. Analysis of the ethanol sensitivities of the cells lacking Sod2p, Yap1p, or both indicated that the two proteins act in the same pathway. Moreover, preconditioning with hydrogen peroxide restored the ethanol resistance of yeast cells with repressed SOD2 Interestingly, we found that mitochondrion-to-nucleus signaling by Rtg proteins antagonizes Yap1p activation. Together, our data suggest that hydrogen peroxide produced by Sod2p activates Yap1p and thus plays a signaling role in ethanol tolerance. Baker's yeast harbors multiple systems that ensure tolerance to high concentrations of ethanol. Still, the role of mitochondria under severe ethanol stress in yeast is not completely clear. Our study revealed a signaling function of mitochondria which contributes significantly to the ethanol tolerance of yeast cells. We found that mitochondrial superoxide dismutase Sod2p and cytoplasmic hydrogen peroxide sensor Yap1p act together as a module of the mitochondrion-to-nucleus signaling pathway. We also report cross talk between this pathway and the conventional retrograde signaling cascade activated by dysfunctional mitochondria. Copyright © 2017 American Society for Microbiology.

In Vivo Imaging of Tau Pathology Using Magnetic Resonance Imaging Textural Analysis

PubMed Central

Colgan, Niall; Ganeshan, Balaji; Harrison, Ian F.; Ismail, Ozama; Holmes, Holly E.; Wells, Jack A.; Powell, Nick M.; O'Callaghan, James M.; O'Neill, Michael J.; Murray, Tracey K.; Ahmed, Zeshan; Collins, Emily C.; Johnson, Ross A.; Groves, Ashley; Lythgoe, Mark F.

2017-01-01

Background: Non-invasive characterization of the pathological features of Alzheimer's disease (AD) could enhance patient management and the development of therapeutic strategies. Magnetic resonance imaging texture analysis (MRTA) has been used previously to extract texture descriptors from structural clinical scans in AD to determine cerebral tissue heterogeneity. In this study, we examined the potential of MRTA to specifically identify tau pathology in an AD mouse model and compared the MRTA metrics to histological measures of tau burden. Methods: MRTA was applied to T2 weighted high-resolution MR images of nine 8.5-month-old rTg4510 tau pathology (TG) mice and 16 litter matched wild-type (WT) mice. MRTA comprised of the filtration-histogram technique, where the filtration step extracted and enhanced features of different sizes (fine, medium, and coarse texture scales), followed by quantification of texture using histogram analysis (mean gray level intensity, mean intensity, entropy, uniformity, skewness, standard-deviation, and kurtosis). MRTA was applied to manually segmented regions of interest (ROI) drawn within the cortex, hippocampus, and thalamus regions and the level of tau burden was assessed in equivalent regions using histology. Results: Texture parameters were markedly different between WT and TG in the cortex (E, p < 0.01, K, p < 0.01), the hippocampus (K, p < 0.05) and in the thalamus (K, p < 0.01). In addition, we observed significant correlations between histological measurements of tau burden and kurtosis in the cortex, hippocampus and thalamus. Conclusions: MRTA successfully differentiated WT and TG in brain regions with varying degrees of tau pathology (cortex, hippocampus, and thalamus) based on T2 weighted MR images. Furthermore, the kurtosis measurement correlated with histological measures of tau burden. This initial study indicates that MRTA may have a role in the early diagnosis of AD and the assessment of tau pathology using routinely acquired structural MR images. PMID:29163005

Mitochondrial Superoxide Dismutase and Yap1p Act as a Signaling Module Contributing to Ethanol Tolerance of the Yeast Saccharomyces cerevisiae

PubMed Central

Zyrina, Anna N.; Smirnova, Ekaterina A.; Markova, Olga V.; Severin, Fedor F.

2016-01-01

ABSTRACT There are two superoxide dismutases in the yeast Saccharomyces cerevisiae—cytoplasmic and mitochondrial enzymes. Inactivation of the cytoplasmic enzyme, Sod1p, renders the cells sensitive to a variety of stresses, while inactivation of the mitochondrial isoform, Sod2p, typically has a weaker effect. One exception is ethanol-induced stress. Here we studied the role of Sod2p in ethanol tolerance of yeast. First, we found that repression of SOD2 prevents ethanol-induced relocalization of yeast hydrogen peroxide-sensing transcription factor Yap1p, one of the key stress resistance proteins. In agreement with this, the levels of Trx2p and Gsh1p, proteins encoded by Yap1 target genes, were decreased in the absence of Sod2p. Analysis of the ethanol sensitivities of the cells lacking Sod2p, Yap1p, or both indicated that the two proteins act in the same pathway. Moreover, preconditioning with hydrogen peroxide restored the ethanol resistance of yeast cells with repressed SOD2. Interestingly, we found that mitochondrion-to-nucleus signaling by Rtg proteins antagonizes Yap1p activation. Together, our data suggest that hydrogen peroxide produced by Sod2p activates Yap1p and thus plays a signaling role in ethanol tolerance. IMPORTANCE Baker's yeast harbors multiple systems that ensure tolerance to high concentrations of ethanol. Still, the role of mitochondria under severe ethanol stress in yeast is not completely clear. Our study revealed a signaling function of mitochondria which contributes significantly to the ethanol tolerance of yeast cells. We found that mitochondrial superoxide dismutase Sod2p and cytoplasmic hydrogen peroxide sensor Yap1p act together as a module of the mitochondrion-to-nucleus signaling pathway. We also report cross talk between this pathway and the conventional retrograde signaling cascade activated by dysfunctional mitochondria. PMID:27864171

Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

NASA Astrophysics Data System (ADS)

Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

2005-02-01

Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.

2005-02-06

Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt asmore » the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.« less

Precision measurements with atom interferometry

NASA Astrophysics Data System (ADS)

Schubert, Christian; Abend, Sven; Schlippert, Dennis; Ertmer, Wolfgang; Rasel, Ernst M.

2017-04-01

Interferometry with matter waves enables precise measurements of rotations, accelerations, and differential accelerations [1-5]. This is exploited for determining fundamental constants [2], in fundamental science as e.g. testing the universality of free fall [3], and is applied for gravimetry [4], and gravity gradiometry [2,5]. At the Institut für Quantenoptik in Hannover, different approaches are pursued. A large scale device is designed and currently being set up to investigate the gain in precision for gravimetry, gradiometry, and fundamental tests on large baselines [6]. For field applications, a compact and transportable device is being developed. Its key feature is an atom chip source providing a collimated high flux of atoms which is expected to mitigate systematic uncertainties [7,8]. The atom chip technology and miniaturization benefits from microgravity experiments in the drop tower in Bremen and sounding rocket experiments [8,9] which act as pathfinders for space borne operation [10]. This contribution will report about our recent results. The presented work is supported by the CRC 1227 DQ-mat, the CRC 1128 geo-Q, the RTG 1729, the QUEST-LFS, and by the German Space Agency (DLR) with funds provided by the Federal Ministry of Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under Grant No. DLR 50WM1552-1557. [1] P. Berg et al., Phys. Rev. Lett., 114, 063002, 2015; I. Dutta et al., Phys. Rev. Lett., 116, 183003, 2016. [2] J. B. Fixler et al., Science 315, 74 (2007); G. Rosi et al., Nature 510, 518, 2014. [3] D. Schlippert et al., Phys. Rev. Lett., 112, 203002, 2014. [4] A. Peters et al., Nature 400, 849, 1999; A. Louchet-Chauvet et al., New J. Phys. 13, 065026, 2011; C. Freier et al., J. of Phys.: Conf. Series 723, 012050, 2016. [5] J. M. McGuirk et al., Phys. Rev. A 65, 033608, 2002; P. Asenbaum et al., arXiv:1610.03832. [6] J. Hartwig et al., New J. Phys. 17, 035011, 2015. [7] H. Ahlers et al., Phys. Rev. Lett. 116, 173601, 2016; S. Abend et al., Phys. Rev. Lett. 117, 203003, 2016. [8] J. Rudolph et al., New J. Phys. 17, 065001, 2015. [9] H. Müntinga et al., Phys. Rev. Lett., 110, 093602, 2013. [10] O. Carraz et al., Microgravity Sci. Technol. 26, 139, 2014; D. Aguilera et al., Class. Quantum Grav. 31, 115010, 2014.

Constitutive mRNA expression and protein activity levels of nine ABC efflux transporters in seven permanent cell lines derived from different tissues of rainbow trout (Oncorhynchus mykiss).

PubMed

Fischer, Stephan; Loncar, Jovica; Zaja, Roko; Schnell, Sabine; Schirmer, Kristin; Smital, Tvrtko; Luckenbach, Till

2011-01-25

Permanent fish cell lines have become common model systems for determining ecotoxicological effects of pollutants. For these cell lines little is known on the cellular active transport mechanisms that control the amount of a compound entering the cell, such as the MXR (multixenobiotic resistance) system mediated by ATP binding cassette (ABC) transport proteins. Therefore, for toxic evaluation of chemicals with those cells information on MXR is important. We here present data on constitutive mRNA expression and protein activity levels of a series of ABC efflux transporters in seven permanent cell lines derived from liver (RTL-W1; R1) and liver hepatoma (RTH-149), gill (RTgill-W1), gonad (RTG-2), gut (RTgutGC) and brain (RTbrain) of rainbow trout (Oncorhynchus mykiss). In addition to known transporters abcb1 (designated here abcb1a), abcb11, abcc1-3, abcc5 and abcg2, we quantified expression levels of a newly identified abcb1 isoform (abcb1b) and abcc4, previously unknown in trout. Quantitative real time PCR (qPCR) indicated that mRNA of the examined ABC transporters was constitutively expressed in all cell lines. Transporter mRNA expression patterns were similar in all cell lines, with expression levels of abcc transporters being 80 to over 1000 fold higher than for abcg2, abcb1a/b and abcb11 (abcc1-5>abcg2>abcb1a/b, 11). Transporter activity in the cell lines was determined by measuring uptake of transporter type specific fluorescent substrates in the presence of activity inhibitors. The combination of the ABCB1 and ABCC transporter substrate calcein-AM with inhibitors cyclosporine A, PSC833 and MK571 resulted in a concentration-dependent fluorescence increase of up to 3-fold, whereas reversin 205 caused a slight, but not concentration-dependent fluorescence increase. Accumulation of the dyes Hoechst 33342 and 2',7'-dichlorodihydrofluorescein diacetate was basically unchanged in the presence of Ko134 and taurocholate, respectively, indicating low Abcg2 and Abcb11 activities, in accordance with low abcg2 and abcb11 transcript levels. Our data indicate that transporter expression and activity patterns in the different trout cell lines are irrespective of the tissue of origin, but are determined by factors of cell cultivation. 2010 Elsevier B.V. All rights reserved.

Base Flow Investigation of the Apollo AS-202 Command Module. Chapter 6

NASA Technical Reports Server (NTRS)

Walpot, Louis M. G.; Wright, Michael J.; Noeding, Peter; Schrijer, Ferry

2011-01-01

In recent years, both Europe and the US are developing hypersonic research and operational vehicles. These include (re)entry capsules (both ballistic and lifting) and lifting bodies such as ExoMars, EXPERT, ARV, CEV and IXV. The research programs are meant to enable technology and engineering capabilities to support during the next decade the development of affordable (possibly reusable) space transportation systems as well as hypersonic weapons systems for time critical targets. These programs have a broad range of goals, ranging from the qualification of thermal protection systems, the assessment of RCS performances, the development of GNC algorithms, to the full demonstration of the performance and operability of the integrated vehicles. Since the aerothermodynamic characteristics influence nearly all elements of the vehicle design, the accurate prediction of the aerothermal environment is a prerequisite for the design of efficient hypersonic systems. Significant uncertainties in the prediction of the hypersonic aerodynamic and the aerothermal loads can lead to conservative margins in the design of the vehicle including its Outer Mould Line (OML), thermal protection system, structure, and required control system robustness. The current level of aerothermal prediction uncertainties results therefore in reduced vehicle performances (e.g., sub-optimal payload to mass ratio, increased operational constraints). On the other hand, present computational capabilities enable the simulation of three dimensional flow fields with complex thermo-chemical models over complete trajectories and ease the validation of these tools by, e.g., reconstruction of detailed wind tunnel tests performed under identified and controlled conditions (flow properties and vehicle attitude in particular). These controlled conditions are typically difficult to achieve when performing in flight measurements which in turn results in large associated measurement uncertainties. Similar problems arise when attempting to rebuild measurements performed in "hot" ground facilities, where the difficulty level is increased by the addition of the free-flow characterization itself. The implementation of ever more sophisticated thermochemical models is no obvious cure to the aforementioned problems since their effect is often overwhelmed by the large measurement uncertainties incurred in both flight and ground high enthalpy facilities. Concurrent to the previous considerations, a major contributor to the overall vehicle mass of re-entry vehicles is the afterbody thermal protection system. This is due to the large acreage (equal or bigger than that of the forebody) to be protected. The present predictive capabilities for base flows are comparatively lower than those for windward flowfields and offer therefore a substantial potential for improving the design of future re-entry vehicles. To that end, it is essential to address the accuracy of high fidelity CFD tools exercised in the US and EU, which motivates a thorough investigation of the present status of hypersonic flight afterbody heating. This paper addresses the predictive capabilities of after body flow fields of re-entry vehicles investigated in the frame of the NATO/RTO - RTG-043 Task Group and is structured as follows: First, the verification of base flow topologies on the basis of available wind-tunnel results performed under controlled supersonic conditions (i.e., cold flows devoid of reactive effects) is performed. Such tests address the detailed characterization of the base flow with particular emphasis on separation/reattachment and their relation to Mach number effects. The tests have been performed on an Apollo-like re-entry capsule configuration. Second, the tools validated in the frame of the previous effort are exercised and appraised against flight-test data collected during the Apollo AS-202 re-entry.

Interplay among Gcn5, Sch9 and Mitochondria during Chronological Aging of Wine Yeast Is Dependent on Growth Conditions

PubMed Central

Picazo, Cecilia; Orozco, Helena; Matallana, Emilia; Aranda, Agustín

2015-01-01

Saccharomyces cerevisiae chronological life span (CLS) is determined by a wide variety of environmental and genetic factors. Nutrient limitation without malnutrition, i.e. dietary restriction, expands CLS through the control of nutrient signaling pathways, of which TOR/Sch9 has proven to be the most relevant, particularly under nitrogen deprivation. The use of prototrophic wine yeast allows a better understanding of the role of nitrogen in longevity in natural and more demanding environments, such as grape juice fermentation. We previously showed that acetyltransferase Gcn5, a member of the SAGA complex, has opposite effects on CLS under laboratory and winemaking conditions, and is detrimental under the latter. Here we demonstrate that integrity of the SAGA complex is necessary for prolonged longevity, as its dismantling by SPT20 deletion causes a drop in CLS under both laboratory and winemaking conditions. The sch9Δ mutant is long-lived in synthetic SC medium, as expected, and the combined deletion of GCN5 partially suppresses this phenotype. However it is short-lived in grape juice, likely due to its low nitrogen/carbon ratio. Therefore, unbalance of nutrients can be more relevant for life span than total amounts of them. Deletion of RTG2, which codes for a protein associated with Gcn5 and is a component of the mitochondrial retrograde signal, and which communicates mitochondrial dysfunction to the nucleus, is detrimental under laboratory, but not under winemaking conditions, where respiration seems not so relevant for longevity. Transcription factor Rgm1 was found to be a novel CLS regulator Sch9-dependently. PMID:25658705

Vibration Testing of Stirling Power Convertors

NASA Technical Reports Server (NTRS)

Hughes, Bill; Goodnight, Thomas; McNelis, Mark E.; Suarez, Vicente J.; Schreiber, Jeff; Samorezov, Sergey

2003-01-01

The NASA John H. Glenn Research Center (GRC) and the U.S. Department of Energy (DOE) are currently developing a high efficient, long life, free piston Stirling convertor for use as an advanced spacecraft power system for future NASA missions. As part of this development, a Stirling Technology Demonstrator Convertor (TDC), developed by Stirling Technology Company (STC) for DOE, was vibration tested at GRC s Structural Dynamics Laboratory (SDU7735) in November- December 1999. This testing demonstrated that the Stirling TDC is able to withstand the harsh random vibration (20 to 2000 Hertz) seen during a typical spacecraft launch and survive with no structural damage or functional power performance degradation, thereby enabling its usage in future spacecraft power systems. The Stirling Vibration Test Team at NASA GRC and STC personnel conducted tests on a single 55 electric watt TDC. The purpose was to characterize the TDC s structural response to vibration and determine if the TDC could survive the vibration criteria established by the Jet Propulsion Laboratory (JPL) for launch environments. The TDC was operated at full-stroke and full power conditions during the vibration testing. The TDC was tested in two orientations, with the direction of vibration parallel and perpendicular to the TDC s moving components (displacer and piston). The TDC successfully passed a series of sine and random vibration tests. The most severe test was a 12.3 Grms random vibration test (peak vibration level of 0.2 g2/Hz from 50 to 250 Hertz) with test durations of 3 minutes per axis. The random vibration test levels were chosen to simulate, with margin, the maximum anticipated launch vibration conditions. As a result of this very successful vibration testing and successful evaluations in other key technical readiness areas, the Stirling power system is now considered a viable technology for future application for NASA spacecraft missions. Possible usage of the Stirling power system would be to supply on- board electric spacecraft power for future NASA Deep-Space Missions, performing as an attractive alternative to Radioisotope Thermoelectric Generators (RTG). Usage of the Stirling technology is also being considered as the electric power source for future Mars rovers, whose mission profiles may exclude the use of photovoltaic power systems (such as exploring at high Martian latitudes or for missions of lengthy durations). GRC s Thermo-Mechanical Systems Branch (5490) provides Stirling technology expertise under a Space Act Agreement with the DOE. Additional vibration testing, by GRC s Structural Systems Dynamics Branch (7733, is planned to continue to demonstrate the Stirling power system s vibration capability as its technology and flight system designs progress.

Solar lens mission concept for interstellar exploration

NASA Astrophysics Data System (ADS)

Brashears, Travis; Lubin, Philip; Turyshev, Slava; Shao, Michael; Zhang, Qicheng

2015-09-01

The long standing approach to space travel has been to incorporate massive on-board electronics, probes and propellants to achieve space exploration. This approach has led to many great achievements in science, but will never help to explore the interstellar medium. Fortunately, a paradigm shift is upon us in how a spacecraft is constructed and propelled. This paper describes a mission concept to get to our Sun's Gravity Lens at 550AU in less than 10 years. It will be done by using DE-STAR, a scalable solar-powered phased-array laser in Earth Orbit, as a directed energy photon drive of low-mass wafersats. [1] [2] [3] [4] [5] With recent technologies a complete mission can be placed on a wafer including, power from an embedded radio nuclear thermal generator (RTG), PV, laser communications, imaging, photon thrusters for attitude control and other sensors. As one example, a futuristic 200 MW laser array consisting of 1 - 10 kw meter scale sub elements with a 100m baseline can propel a 10 gram wafer scale spacecraft with a 3m laser sail to 60AU/Year. Directed energy propulsion of low-mass spacecraft gives us an opportunity to capture images of Alpha Centauri and its planets, detailed imaging of the cosmic microwave background, set up interstellar communications by using gravity lenses around nearby stars to boost signals from interstellar probes, and much more. This system offers a very large range of missions allowing hundreds of wafer scale payload launches per day to reach this cosmological data reservoir. Directed Energy Propulsion is the only current technology that can provide a near-term path to utilize our Sun's Gravity Lens.

Draft Environmental Impact Statement for the Ulysses Mission (Tier 2)

NASA Technical Reports Server (NTRS)

1990-01-01

This Draft Environmental Impact Statement (DEIS) addresses the environmental impacts which may be caused by the preparation and operation of the Ulysses spacecraft, including its planned launch on the Space Transportation System (STS) Shuttle and the alternative of canceling further work on the mission. The launch configuration will use the STS/Inertial Upper Stage (IUS)/Payload Assist Module-Special(PAM-S) combination. The Tier 1 EIS included a delay alternative which considered the Titan 4 launch vehicle as an alternative booster stage for launch in 1991 or later. However, the U.S. Air Force, which procures the Titan 4 for NASA, could not provide a Titan 4 vehicle for the 1991 launch opportunity because of high priority Department of Defense requirements. The only expected environmental effects of the proposed action are associated with normal Shuttle launch operations. These impacts are limited largely to the near-field at the launch pad, except for temporary stratospheric ozone effects during launch and occasional sonic boom effects near the landing site. These effects have been judged insufficient to preclude Shuttle launches. In the event of (1) an accident during launch, or (2) reentry of the spacecraft from earth orbit, there are potential adverse health and environmental effects associated with the possible release of plutonium dioxide from the spacecraft's radioisotope thermoelectric generators (RTG). The potential effects considered in this EIS include risks of air and water quality impacts, local land area contamination, adverse health and safety impacts, the disturbance of biotic resources, impacts on wetland areas or areas containing historical sites, and socioeconomic impacts. Intensive analysis of the possible accidents associated with the proposed action are underway and preliminary results indicate small health or environmental risks. The results of a Final Safety Analysis Report will be available for inclusion into the final EIS.

Defective postnatal endochondral bone development by chondrocyte-specific targeted expression of parathyroid hormone type 2 receptor.

PubMed

Panda, Dibyendu Kumar; Goltzman, David; Karaplis, Andrew C

2012-12-15

The human parathyroid hormone type 2 receptor (PTH2R) is activated by PTH and by tuberoinfundibular peptide of 39 residues (TIP39), the latter likely acting as its natural ligand. Although the receptor is expressed at highest levels in the nervous system, we have observed that both PTH2R and TIP39 are expressed in the newborn mouse growth plate, with the receptor localizing in the resting zone and the ligand TIP39 localizing exclusively in prehypertrophic and hypertrophic chondrocytes. To address the role of PTH2R in postnatal skeletal growth and development, Col2a1-hPTH2R (PTH2R-Tg) transgenic mice were generated. The mice were viable and of nearly normal size at birth. Expression of the transgene in the growth plate was limited to chondrocytes. We found that chondrocyte proliferation was decreased, as determined by in vivo BrdU labeling of proliferating chondrocytes and CDK4 and p21 expression in the growth plate of Col2a1-hPTH2R transgenic mice. Similarly, the differentiation and maturation of chondrocytes was delayed, as characterized by decreased Sox9 expression and weaker immunostaining for the chondrocyte differentiation markers collagen type II and type X and proteoglycans. As well, there was altered expression of Gdf5, Wdr5, and β-catenin, factors implicated in chondrocyte maturation, proliferation, and differentiation.These effects impacted on the process of endochondral ossification, resulting in delayed formation of the secondary ossification center, and diminished trabecular bone volume. The findings substantiate a role for PTH2R signaling in postnatal growth plate development and subsequent bone mass acquisition.

Density Variations in Quartz As a Key for Deciphering Impact-Related Ultrasonic Sounding (Rajlich's Hypothesis)?

NASA Astrophysics Data System (ADS)

Mestan, J.; Alvarez Polanco, E. I.

2014-12-01

Ultrasound is a form of mechanical energy with a frequency greater than ≈ 20 kHz (upper human hearing limit). It is used in many scientific as well as industrial fields. Most modern applications of ultrasound utilize sources which are either piezoelectric or magnetostrictive (Benwell et Bly 1987). A meteorite impact has been considered to be an ultrasound source during last years (Rajlich 2011). Rajlich (2014) is coming with a hypothesis that white planes made of microcavities in Bohemian quartz have their origin in an impact-related ultrasonic sounding. The Bohemian Massif has been considered to be one of the largest impact craters in whole of the world (Papagiannis et El-Baz 1988, Papagiannis 1989, Rajlich 2014). Rajlich's hypothesis implies a liquid behavior of quartz during the impact event. We state that then there have to exist planes of slightly higher density than their surroundings together with planes of microcavities. They should intersect each other without mutual influencing (as in a case of planes made of microcavities). Because physics of ultrasound during an impact event is a brand new and unknown field, we try to choose a simple way of its cognition. It is possible to take the sine wave and set 3 requirements. (1) There exist some surroundings of points of peak amplitudes. (2) These surroundings are of higher density (compression) or lower density (rarefaction) than the mean density of quartz. (3) The difference between the higher/lower and surrounding density is measurable. There was done an experimental study of Bohemian quartz using QCT bone densitometry at the Radiology Munich. Quartz with a size of ≈ 5 x 8 cm absorbed too much RTG radiation (kV 140, mAs 330), which made a picture of internal structure impossible. We propose another techniques and appeal to other scientists to face this challenge. If Bohemian quartz has a harmonically distributed density, we consider it to be a support for Rajlich's hypothesis. AcknowledgementsWe would like to thank to Prof. Martin Mack for the fact he enabled an irradiation of quartz sample at the Radiology Munich.

Lunar Surface Stirling Power Systems Using Isotope Heat Sources

NASA Technical Reports Server (NTRS)

Schmitz, Paul C.; Penswick, L. Barry; Shaltens, Richard K.

2010-01-01

For many years, NASA has used the decay of plutonium-238 (Pu-238) (in the form of the General Purpose Heat Source (GPHS)) as a heat source for Radioisotope Thermoelectric Generators (RTGs), which have provided electrical power for many NASA missions. While RTGs have an impressive reliability record for the missions in which they have been used, their relatively low thermal to electric conversion efficiency and the scarcity of plutonium-238 (Pu-238) has led NASA to consider other power conversion technologies. NASA is considering returning both robotic and human missions to the lunar surface and, because of the long lunar nights (14.75 Earth days), isotope power systems are an attractive candidate to generate electrical power. NASA is currently developing the Advanced Stirling Radioisotope Generator (ASRG) as a candidate higher efficiency power system that produces greater than 160 W with two GPHS modules at the beginning of life (BOL) (32% efficiency). The ASRG uses the same Pu-238 GPHS modules, which are used in RTG, but by coupling them to a Stirling convertor provides a four-fold reduction in the number of GPHS modules. This study considers the use of americium-241 (Am-241) as a substitute for the Pu-238 in Stirling- convertor-based Radioisotope Power Systems (RPS) for power levels from tens of watts to 5 kWe. The Am-241 is used as a substitute for the Pu-238 in GPHS modules. Depending on power level, different Stirling heat input and removal systems are modeled. It was found that substituting Am-241 GPHS modules into the ASRG reduces power output by about one-fifth while maintaining approximately the same system mass. In order to obtain the nominal 160 W of electrical output of the Pu-238 ASRG requires 10 Am-241 GPHS modules. Higher power systems require changing from conductive coupling heat input and removal from the Stirling convertor to either pumped loops or heat pipes. Liquid metal pumped loops are considered as the primary heat transportation on the hot end and water pumped loop/heat pipe radiator is considered for the heat rejection side for power levels above 1 kWe.

Role of upper-ocean on the intensity of Bay of Bengal cyclone `Phailin' as revealed by coupled simulation using Mesoscale Coupled Modeling System (WRF-ROMS)

NASA Astrophysics Data System (ADS)

Mani, B.; Mandal, M.

2016-12-01

Numerical prediction of tropical cyclone (TC) track has improved significantly in recent years, but not the intensity. It is well accepted that TC induced sea surface temperature (SST) cooling in conjunction with pre-existing upper-ocean features have major influences on tropical cyclone intensity. Absence of two-way atmosphere-ocean feedback in the stand-alone atmosphere models has major consequences on their prediction of TC intensity. The present study investigates the role of upper-ocean on prediction of TC intensity and track based on coupled and uncoupled simulation of the Bay of Bengal (BoB) cyclone `Phailin'. The coupled simulation is conducted with the Mesoscale Coupled Modeling System (MCMS) which is a fully coupled atmosphere-ocean modeling system that includes the non-hydrostatic atmospheric model (WRF-ARW) and the three-dimensional hydrostatic ocean model (ROMS). The uncoupled simulation is performed using the atmosphere component of MCMS i.e., the customized version of WRF-ARW for BoB cyclones with prescribed (RTG) SST. The track and intensity of the storm is significantly better simulated by the MCMS and closely followed the observation. The peak intensity, landfall position and time are accurately predicted by MCMS, whereas the uncoupled simulation over predicted the storm intensity. Validation of storm induced SST cooling with the merged microwave-infrared satellite SST indicates that the MCMS simulation shows better correlation both in terms of spatial spread of cold wake and its magnitude. The analysis also suggests that the Pre-existing Cyclonic Eddy (PCE) observed adjacent to the storm enhanced the TC induced SST cooling. It is observed that the response of SST (i.e., cooling) to storm intensity is 12hr with 95% statistical significance. The air-sea enthalpy flux shows a clear asymmetry between Front Left (FL) and Rear Right (RR) regime to the storm center where TC induced cooling is more than 0.5K/24hr. The analysis of atmospheric boundary layer reveals the formation of persistent stable boundary layer (SBL) over the cold wake, which caused asymmetry in TC structure by quelling convection in the rainbands downstream to the cold wake. The present study signifies the importance of using MCMS in prediction of the BoB cyclone and encourages further investigation with more cyclone cases.

Direct Measurements of Oxygen Gradients in Spheroid Culture System Using Electron Parametric Resonance Oximetry

PubMed Central

Langan, Laura M.; Dodd, Nicholas J. F.; Owen, Stewart F.; Purcell, Wendy M.; Jackson, Simon K.; Jha, Awadhesh N.

2016-01-01

Advanced in vitro culture from tissues of different origin includes three-dimensional (3D) organoid micro structures that may mimic conditions in vivo. One example of simple 3D culture is spheroids; ball shaped structures typically used as liver and tumour models. Oxygen is critically important in physiological processes, but is difficult to quantify in 3D culture: and the question arises, how small does a spheroid have to be to have minimal micro-environment formation? This question is of particular importance in the growing field of 3D based models for toxicological assessment. Here, we describe a simple non-invasive approach modified for the quantitative measurement and subsequent evaluation of oxygen gradients in spheroids developed from a non-malignant fish cell line (i.e. RTG-2 cells) using Electron Paramagnetic Resonance (EPR) oximetry. Sonication of the paramagnetic probe Lithium phthalocyanine (LiPc) allows for incorporation of probe particulates into spheroid during its formation. Spectra signal strength after incorporation of probe into spheroid indicated that a volume of 20 μl of probe (stock solution: 0.10 mg/mL) is sufficient to provide a strong spectra across a range of spheroid sizes. The addition of non-toxic probes (that do not produce or consume oxygen) report on oxygen diffusion throughout the spheroid as a function of size. We provide evidence supporting the use of this model over a range of initial cell seeding densities and spheroid sizes with the production of oxygen distribution as a function of these parameters. In our spheroid model, lower cell seeding densities (∼2,500 cells/spheroid) and absolute size (118±32 μm) allow control of factors such as pre-existing stresses (e.g. ∼ 2% normoxic/hypoxic interface) for more accurate measurement of treatment response. The applied methodology provides an elegant, widely applicable approach to directly characterize spheroid (and other organoid) cultures in biomedical and toxicological research. PMID:26900704

Direct Measurements of Oxygen Gradients in Spheroid Culture System Using Electron Parametric Resonance Oximetry.

PubMed

Langan, Laura M; Dodd, Nicholas J F; Owen, Stewart F; Purcell, Wendy M; Jackson, Simon K; Jha, Awadhesh N

2016-01-01

Advanced in vitro culture from tissues of different origin includes three-dimensional (3D) organoid micro structures that may mimic conditions in vivo. One example of simple 3D culture is spheroids; ball shaped structures typically used as liver and tumour models. Oxygen is critically important in physiological processes, but is difficult to quantify in 3D culture: and the question arises, how small does a spheroid have to be to have minimal micro-environment formation? This question is of particular importance in the growing field of 3D based models for toxicological assessment. Here, we describe a simple non-invasive approach modified for the quantitative measurement and subsequent evaluation of oxygen gradients in spheroids developed from a non-malignant fish cell line (i.e. RTG-2 cells) using Electron Paramagnetic Resonance (EPR) oximetry. Sonication of the paramagnetic probe Lithium phthalocyanine (LiPc) allows for incorporation of probe particulates into spheroid during its formation. Spectra signal strength after incorporation of probe into spheroid indicated that a volume of 20 μl of probe (stock solution: 0.10 mg/mL) is sufficient to provide a strong spectra across a range of spheroid sizes. The addition of non-toxic probes (that do not produce or consume oxygen) report on oxygen diffusion throughout the spheroid as a function of size. We provide evidence supporting the use of this model over a range of initial cell seeding densities and spheroid sizes with the production of oxygen distribution as a function of these parameters. In our spheroid model, lower cell seeding densities (∼2,500 cells/spheroid) and absolute size (118±32 μm) allow control of factors such as pre-existing stresses (e.g. ∼ 2% normoxic/hypoxic interface) for more accurate measurement of treatment response. The applied methodology provides an elegant, widely applicable approach to directly characterize spheroid (and other organoid) cultures in biomedical and toxicological research.

The Telemachus mission: dynamics of the polar sun and heliosphere

NASA Astrophysics Data System (ADS)

Roelof, E.

Telemachus in Greek mythology was the faithful son of Ulysses. The Telemachus mission is envisioned as the next logical step in the exploration of the polar regions of the Sun and heliosphere so excitingly initiated by the ESA/NASA Ulysses mission. Telemachus is a polar solar-heliospheric mission described in the current NASA Sun-Earth Connections Roadmap (2003-2028) that has successfully undergone two Team X studies by NASA/JPL. The pioneering observations from Ulysses transformed our perception of the structure and dynamics of these polar regions through which flow the solar wind, magnetic fields and energetic particles that eventually populate most of the volume of the heliosphere. Ulysses carried only fields and particles detectors. Telemachus, in addition to modern versions of such essential in situ instruments, will carry imagers that will give solar astronomers a new viewpoint on coronal mass ejections and solar flares, as well as their first purely polar views of the photospheric magnetic field, thereby providing new helioseismology to probe the interior of the Sun. Unlike the RTG-powered Ulysses, the power for Telemachus will come simply from solar panels. Gravity assist encounters with Venus and Earth (twice) will yield ˜5 years of continuous in-ecliptic cruise science between 0.7 AU and 3.3 AU that will powerfully complement other contemporary solar-heliospheric missions. The Jupiter gravity assist, followed by a perihelion burn ˜8 years after launch, will place Telemachus in a permanent ˜0.2 AU by 2.5 AU heliographic polar orbit (inclination >80 deg) whose period will be 1.5 years. Telemachus will then pass over the solar poles at ˜0.4 AU (compared to 1.4 AU for Ulysses) and spend ˜2 weeks above 60 deg on each polar pass (alternating perihelions between east and west limbs as viewed from Earth). In 14 polar passes during a 10.5 year solar cycle, Telemachus would accumulate over half a year of polar science data. During the remainder of the time, it would be charting the dynamics of all latitudes of the transition region that imposes the structure upon the solar wind, magnetic field, and energetic particle populations that determines the configuration and evolution of the outer heliosphere and its boundary with the local interstellar medium.

A Study of an Unmanned Lunar Mission for the Assay of Volatile Gases from the Soil

NASA Astrophysics Data System (ADS)

Wittenberg, L. J.; Sviatoslavsky, I. N.; Kulcinski, G. L.; Mogahed, E. A.

1999-01-01

The success of a manned lunar outpost may require that indigenous resources be utilized in order to reduce the requirements for the periodic resupply from Earth for the human inhabitants. Some indigenous lunar resources do exist. For instance, studies of the lunar regoliths, acquired by the Apollo and Luna missions from several maria, indicate that upon heating in a vacuum, these soils evolve the volatile gases: helium (He), hydrogen (H2), carbon dioxide (CO2), carbon monoxide (CO), nitrogen (N2), and sulfur dioxide (SO2). The He, H, C, and N were originally implanted by solar wind These gases would be valuable to supply life-support systems. For instance, the H2 could be used as a rocket fuel, or alternatively, reacted with the mineral ilmenite (FeTiO3), indigenous to the lunar soil, to yield water (H2O). In an enclosed structure irradiated by solar energy, the H2O, N2, and CO2 could be utilized to grow edible plants for lunar inhabitants. Alternatively, the H2O could be electrolyzed, using photovoltaic cells, yielding breathable O. The inert gas He, would be useful for filling inflatable structures. In addition, the lunar He contains a high abundance of the rare isotopic He-3, which has been identified as a potentially valuable fuel for nuclear-fusion space power systems. In order to determine the economic potential of these lunar volatiles, we need information to assess the in situ quantities of these gases and identify the most abundant sites. In order to acquire such information, a large number of soil samples must be acquired and analyzed because it is not known if these volatile gases in the soil vary widely over the distance of a few meters or several kilometers. In addition, all of the lunar soil samples were analyzed on Earth, after being contaminated by terrestrial air and water. For these reasons, therefore, a mobile, robotic vehicle has been proposed that would be landed-on a lunar maria and assay the volatiles evolved by heating the indigenous lunar regolith. A lunar rover platform with the sample equipment attached has been designed. This science platform was conceptionally designed to fit on a small Marsokhod Rover (75 kg) with a 100-km range. The proposed sampling protocol would be to collect two samples, nearly adjacent. If the results agreed within the experimental deviation, the rover would proceed 0.5 km along the planned route and select two new samples. The progress of the rover and the results of the analyses would be continuously monitored from Earth so that the sampling protocol could be revised as needed. The scientific equipment would accomplish the assay of the regolith samples in the following sequence: (1) retrieve a sample of regolith from the lunar surface by use of a scoop mounted on the platform; (2) reduce the sample to about 1 g of particles <200 pm; (3) weigh the sample; (4) characterize the mineral content (TiO2); (5) heat the sample to 1200C in a vacuum furnace; (6) collect the volatiles; (7) characterize the volatile products; and (8) transmit the data. The components of the scientific package were conceptually designed and are briefly described: (1) The heater unit. A 1 g sample of the surface regolith would be placed in a ferritic steel crucible 0.8 cm OD x 1.57 cm high. This container would be placed in a coiled electrical heater inside an evacuated 1-L container. Heat transfer calculations indicate that the sample would attain 1200C in 14 min with a 25-W heater. For a high-Ti maria regolith sufficient gases are released to create a pressure of 70 Pa at 30C, which is a sufficient sample for the mass spectrometer. (2) Determination of metallic elements. Before the sample is heated, a laser beam delivers 0.45-2.0 Joules per pulse at a wave length of 1 micron to the surface of the sample. The absorption of the laser energy vaporizes some of the minerals in the soils. The vaporized ions are quantitatively determined by the mass spectrometer. (3) Mass spectrometer. This instrument must be utilized to characterize the mineral content of the soil and the volatile gases, essentially from 1 to 72 AMU range. A Fourier Transform Mass Spectrometer (FTMS) may be particularly useful for this analysis, but requires testing. (4) Powersupply. The initial power subsystem assumed the availability of a general purpose heat source, or a Radioisotope Thermoelectric Generator. If the launch of an RTG is forbidden for safety reasons, alternative power supplies would be considered such as solar-electric or beamed microwave sources.

The Transition of High-Resolution NASA MODIS Sea Surface Temperatures into the WRF Environmental Modeling System

NASA Technical Reports Server (NTRS)

Case, Jonathan L.; Jedlove, Gary J.; Santos, Pablo; Medlin, Jeffrey M.; Rozumalski, Robert A.

2009-01-01

The NASA Short-term Prediction Research and Transition (SPoRT) Center has developed a Moderate Resolution Imaging Spectroradiometer (MODIS) sea surface temperature (SST) composite at 2-km resolution that has been implemented in version 3 of the National Weather Service (NWS) Weather Research and Forecasting (WRF) Environmental Modeling System (EMS). The WRF EMS is a complete, full physics numerical weather prediction package that incorporates dynamical cores from both the Advanced Research WRF (ARW) and the Non-hydrostatic Mesoscale Model (NMM). The installation, configuration, and execution of either the ARW or NMM models is greatly simplified by the WRF EMS to encourage its use by NWS Weather Forecast Offices (WFOs) and the university community. The WRF EMS is easy to run on most Linux workstations and clusters without the need for compilers. Version 3 of the WRF EMS contains the most recent public release of the WRF-NMM and ARW modeling system (version 3 of the ARW is described in Skamarock et al. 2008), the WRF Pre-processing System (WPS) utilities, and the WRF Post-Processing program. The system is developed and maintained by the NWS National Science Operations Officer Science and Training Resource Coordinator. To initialize the WRF EMS with high-resolution MODIS SSTs, SPoRT developed the composite product consisting of MODIS SSTs over oceans and large lakes with the NCEP Real-Time Global (RTG) filling data over land points. Filling the land points is required due to minor inconsistencies between the WRF land-sea mask and that used to generate the MODIS SST composites. This methodology ensures a continuous field that adequately initializes all appropriate arrays in WRF. MODIS composites covering the Gulf of Mexico, western Atlantic Ocean and the Caribbean are generated daily at 0400, 0700, 1600, and 1900 UTC corresponding to overpass times of the NASA Aqua and Terra polar orbiting satellites. The MODIS SST product is output in gridded binary-1 (GRIB-1) data format for a seamless incorporation into WRF via the WPS utilities. The full-resolution, 1-km MODIS product is sub-sampled to 2-km grid spacing due to limitations in handling very large dimensions in the GRIB-1 data format. The GRIB-1 files are posted online at ftp://ftp.nsstc.org/sstcomp/WRF/, which is directly accessed by the WRF EMS scripts. The MODIS SST composites are also downloaded to the EMS data server, which is accessible by the WRF EMS users and NWS WFOs. The SPoRT MODIS SST composite provides the model with superior detail of the ocean gradients around Florida and surrounding waters, whereas the operational RTG SST typically depicts a relatively smooth field and is not able to capture sharp horizontal gradients in SST. Differences of 2-3 C are common over small horizontal distances, leading to enhanced SST gradients on either side of the Gulf Stream and along the edges of the cooler shelf waters. These sharper gradients can in turn produce atmospheric responses in simulated temperature and wind fields as depicted in LaCasse et al. Differences in atmospheric verification statistics over a several month study were generally small in the vicinity of south Florida; however, the validation of SSTs at specific buoy locations revealed important improvements in the biases and RMS errors, especially in the vicinity of the cooler shelf waters off the east-central Florida coast. A current weakness in the MODIS SST product is the occurrence of occasional discontinuities caused by high latency in SST coverage due to persistent cloud cover. An enhanced method developed by Jedlovec et al. (2009, GHRSST User Symposium) reduces the occurrence of these problems by adding Advanced Microwave Scanning Radiometer -- EOS (AMSR-E) SST data to the compositing process. Enhanced SST composites are produced over the ocean regions surrounding the Continental U.S. at four times each day corresponding to Terra and Aqua equator crossing times. For a given day and overpass time, both MODInd AMSR-E data from the previous seven days form a collection used in the compositing. At each MODIS pixel, cloud-free SST values from the collection are used to form a weighted average based on their latency (number of days from the current day). In this way, recent SST data are given more weight than older data. One of the primary issues involved in incorporating the AMSR-E microwave data in the composites is the tradeoff between the decreased spatial resolution of the AMSR-E data (25 km) and the increased coverage due to its near all-weather capability. Currently, the AMSR-E is given a weight of 20% compared to MODIS data, thereby preserving the spatial structure observed in the MODIS data. Day-time (night-time) AMSR-E SST data from Aqua are used with both Terra and Aqua MODIS day-time (night-time) SST data sets.

Zero Boil Off Cryogen Storage for Future Launchers

NASA Technical Reports Server (NTRS)

Valentian, D.; Plachta, D.; Kittel, P.; Hastings, L. J.; Salerno, Louis J.; Arnold, James O. (Technical Monitor)

2001-01-01

Zero boil off (ZBO) cryogen storage using both cryocoolers and passive insulation technologies will enable long-term exploration missions by allowing designers to optimize tankage without the need for excess cryogen storage to account for boil off. Studies of ZBO (zero boil off) have been on-going in the USA for several years. More recently, a review of the needs of advanced space propulsion took place in Europe. This showed the interest of the European community in cryogenic propulsion for planetary missions as well as the use of liquid hydrogen for large power electric propulsion (manned Mars missions). Although natural boiling could be acceptable for single leg missions, passive insulation techniques yield roughly a I% per month cryogen loss and this would not be cost effective for robotic planetary missions involving storage times greater than one year. To make economic sense, long-term exploration missions require lower tank capacity and longer storage times. Recent advances in cryocooler technology, resulting in vast improvements in both cooler efficiency and reliability, make ZBO is a clear choice for planetary exploration missions. Other, more near term applications of ZBO include boil-off reduction or elimination applied to first and upper stages of future earth-to-orbit (ETO) launchers. This would extend launch windows and reduce infrastructure costs. Successors to vehicles like Ariane 5 could greatly benefit by implementing ZBO. Zero Boil Off will only be successful in ETO launcher applications if it makes economic sense to implement. The energy cost is only a fraction of the total cost of buying liquid cryogen, the rest being transportation and other overhead. Because of this, higher boiling point cryogens will benefit more from on-board liquefaction, thus reducing the infrastructure costs. Since hydrogen requires a liquefier with at least a 17% efficiency just to break even from a cost standpoint, one approach for implementing ZBO in upper stages would be to actively cool the shield in the hydrogen tank to reduce the parasitic losses. This would allow the use of less expensive, presently available coolers (80 K vs. 20 K) and potentially simplify the system by requiring only a single compressor on the pad amd a single disconnect line. The compressor could be a hefty commercial unit, with only the cold head requiring expensive flight development and qualification. While this is actually a reduced boil off configuration rather than a zero-boil off case, if the cryogen loss could be cut significantly, the increase in hold time and reduced need for draining and refilling the propellant tanks could meet the vehicle operations needs in the majority of instances.Bearing in mind the potential benefits of ZBO, NASA AMES and SNECMA Moteurs decided to exchange their technical views on the subject. This paper will present a preliminary analysis for a multi-mission module using a fairly low thrust cryogenic engine and ZBO during cruise. Initial mass is 5.5. tons (in ETO). The cryogenic engine will be used near each periapsis in order to minimize the AV requirement. The payload obtained by this propulsion system is compared to a classical storable bipropellant propulsion system for several cases (e. g. Mars lander, Jupiter orbiter, Saturn orbiter). For the Jupiter and Saturn cases, the power source could be an RTG or a large parabolic mirror illuminating a solar panel. It is shown -that - due to its much larger specific impulse - the cryogenic ZBO solution provides much higher payloads, especially for exploration missions involving landing on planets, asteroids, comets, or other celestial bodies.

Oceans of Opportunity: Partnerships to Increase Minority Student Involvement in the Marine Geosciences

NASA Astrophysics Data System (ADS)

Pride, C.; Christensen, B.

2007-12-01

The Oceans of Opportunity program to increase involvement of traditionally under-represented students in the marine geosciences is in its final phase of track 1 funding from NSF. The program employs a tiered approach to research, teaching and outreach activities to enhance the K-12 to graduate pipeline. Partner institutions include Savannah State University, an HBCU in coastal Georgia; Adelphi University serving a minority population from NYC; the Georgia State University Bio-Bus serving the metro-Atlanta area; and the Joint Oceanographic Institutions. The Oceans of Opportunity education pipeline includes 1) service learning activities implemented by SSU marine science majors in partner public schools with high minority enrollment; 2) outreach by the Georgia State University Bio-Bus to Savannah area schools; 3) expansion of the SSU geoscience curriculum; and 4) development of activities based on models of ODP cores for use in both outreach and college teaching. Service learning through SSU classes has permitted contact with a large number of K-12 students. More than 1000 predominantly African-American K-12 students completed hands-on lessons on plate tectonics and plankton contributors to marine sediments in the two years of this program under the guidance of HBCU science majors. Lessons on use of the marine sediment and fossil record as proxies in paleoclimatic studies using replicas of ODP cores were delivered to 600 students in the Savannah school system and about 2000 visitors to the Georgia Aquarium in Atlanta. The marine geoscience lessons delivered at the high school level resulted in greater test score improvement when the topic had already been thoroughly introduced by the teacher. A survey of science attitudes of the high school students (n=419) indicates African-American high school students have low levels of enjoyment of and interest in the sciences. In addition, more female than male African-American students are enrolling in science courses and intend to become science majors. The geosciences fared worse than most other STEM fields with most college-bound students saying that they did not intend on taking a geoscience course in college. We established Research Training Groups (RTGs) including undergraduate and graduate students focusing on 1) Georgia shelf, estuarine and marsh dynamics, and 2) South African Pleistocene paleoceanography. Collaborative projects between SSU and Adelphi during the course of this program have engaged 12 students (75% minority) in research on shelf and salt marsh micropaleontology and sedimentation, diatoms in modern estuarine environments, and South African paleoclimate using ODP records. RTG students have also developed a marine sediment repository at SSU, participated in field excursions and research cruises, and presented their research at conferences.

Pressurized Lunar Rover

NASA Technical Reports Server (NTRS)

Creel, Kenneth; Frampton, Jeffrey; Honaker, David; Mcclure, Kerry; Zeinali, Mazyar

1992-01-01

The pressurized lunar rover (PLR) consists of a 7 m long, 3 m diameter cylindrical main vehicle and a trailer which houses the power and heat rejection systems. The main vehicle carries the astronauts, life support systems, navigation and communication systems, directional lighting, cameras, and equipment for exploratory experiments. The PLR shell is constructed of a layered carbon-fiber/foam composite. The rover has six 1.5 m diameter wheels on the main body and two 1.5 m diameter wheels on the trailer. The wheels are constructed of composites and flex to increase traction and shock absorption. The wheels are each attached to a double A-arm aluminum suspension, which allows each wheel 1 m of vertical motion. In conjunction with a 0.75 m ground clearance, the suspension aids the rover in negotiating the uneven lunar terrain. The 15 N-m torque brushless electric motors are mounted with harmonic drive units inside each of the wheels. The rover is steered by electrically varying the speeds of the wheels on either side of the rover. The PLR trailer contains a radiosotope thermoelectric generator providing 6.7 kW. A secondary back-up energy storage system for short-term high-power needs is provided by a bank of batteries. The trailer can be detached to facilitate docking of the main body with the lunar base via an airlock located in the rear of the PLR. The airlock is also used for EVA operation during missions. Life support is a partly regenerative system with air and hygiene water being recycled. A layer of water inside the composite shell surrounds the command center. The water absorbs any damaging radiation, allowing the command center to be used as a safe haven during solar flares. Guidance, navigation, and control are supplied by a strapdown inertial measurement unit that works with the on-board computer. Star mappers provide periodic error correction. The PLR is capable of voice, video, and data transmission. It is equipped with two 5 W X-band transponder, allowing simultaneous transmission and reception. An S-band transponder is used to communicate with the crew during EVA. The PLR has a total mass of 6197 kg. It has a nominal speed of 10 km/hr and a top speed of 18 km/hr. The rover is capable of towing 3 metric tons (in addition to the RTG trailer).

Description of the REMS Ground Temperature Sensor aboard MSL NASA mission to Mars

NASA Astrophysics Data System (ADS)

Armiens, C.; Sebastian, E.; Gomez-Elvira, J.

2009-04-01

The Rover Environmental Monitoring Station, REMS, is part of the payload of the Mars Science Laboratory, MSL, a NASA mission to the red planet recently scheduled to launch on the fall of 2011. REMS comprises several instruments aimed at measuring ground and air temperature, wind speed and direction, ultraviolet radiation, pressure and humidity. The Ground Temperature Sensor, GTS, is a contactless multi band pyrometer. It is composed of three thermopiles measuring in different bands: 8 - 14 um, 16 - 20 um and 14.5 - 15.5 um. The first two bands are optimized for the higher and lower temperatures expected to be present on Mars during the lifetime of the mission. They also avoid the radiation generated by the rover itself, the Radioisotope Thermoelectric Generator, RTG, and the Sun that is reflected on the ground and reaches the thermopiles, as well as the atmospheric emission originated by the CO2. The use of two different bands to measure ground temperature allows the estimation of the emissivity of the surface by means of colour pyrometry algorithms. Thus we may determine not only the brightness temperature but also the real temperature of the ground, i.e., the kinetic temperature. The estimation of the emissivity may serve also to detect changes in the composition of the ground, as, for example, the formation of frost. The third thermopile is centred in the CO2 absorption band, the main component of the Martian atmosphere. This allows the determination of the residual influence that the atmosphere may have in the other two thermopile's bands. The brightness temperature of the air may also be estimated from this third thermopile. During Martian operations, the system may be degraded due to the deposition of dust over the thermopiles' filter. In order to correct for this degradation, the system includes a calibration plate, which partially fills the field of view of the thermopiles. This plate may be heated several degrees. Analyzing the signals before and during the heating process, one may estimate the fraction of the filter covered by dust. This procedure needs the ground temperature to be as stable as possible, so it will be performed just before dawn, when soil temperature changes are expected to be minimum.

Improving the design of maintenance studies for bipolar disorder.

PubMed

Gitlin, Michael J; Abulseoud, Osama; Frye, Mark A

2010-08-01

In contrast to the trial design of acute mania studies, there is no standard design for bipolar maintenance studies. Over the past 15 years, the design of monotherapy maintenance studies in bipolar disorder has evolved significantly, but recent study designs continue to differ in important ways. We reviewed the design of recent controlled bipolar maintenance studies, using PubMed, from August 2006 to August 2009, examining the strengths and weaknesses of different study design features. Design differences are sufficiently important that the disparate results across maintenance studies may reflect either true differences in medication efficacy or the effects of these design differences on outcome. Design elements such as recent episode polarity, stabilization criteria, using enriched versus nonenriched samples, length of stabilization before randomization, length of experimental phase, and recurrence outcome criteria are critical factors that differ widely across studies and likely play a role in study outcome. As consensus for trial designs for bipolar maintenance therapy is developed, it will be easier to develop algorithms for maintenance treatment based on results from studies as opposed to clinical opinions.

Visual Design Principles: An Empirical Study of Design Lore

ERIC Educational Resources Information Center

Kimball, Miles A.

2013-01-01

Many books, designers, and design educators talk about visual design principles such as balance, contrast, and alignment, but with little consistency. This study uses empirical methods to explore the lore surrounding design principles. The study took the form of two stages: a quantitative literature review to determine what design principles are…

Study/experimental/research design: much more than statistics.

PubMed

Knight, Kenneth L

2010-01-01

The purpose of study, experimental, or research design in scientific manuscripts has changed significantly over the years. It has evolved from an explanation of the design of the experiment (ie, data gathering or acquisition) to an explanation of the statistical analysis. This practice makes "Methods" sections hard to read and understand. To clarify the difference between study design and statistical analysis, to show the advantages of a properly written study design on article comprehension, and to encourage authors to correctly describe study designs. The role of study design is explored from the introduction of the concept by Fisher through modern-day scientists and the AMA Manual of Style. At one time, when experiments were simpler, the study design and statistical design were identical or very similar. With the complex research that is common today, which often includes manipulating variables to create new variables and the multiple (and different) analyses of a single data set, data collection is very different than statistical design. Thus, both a study design and a statistical design are necessary. Scientific manuscripts will be much easier to read and comprehend. A proper experimental design serves as a road map to the study methods, helping readers to understand more clearly how the data were obtained and, therefore, assisting them in properly analyzing the results.

Does design matter? Systematic evaluation of the impact of analytical choices on effect estimates in observational studies

PubMed Central

Ryan, Patrick B.; Schuemie, Martijn

2013-01-01

Background: Clinical studies that use observational databases, such as administrative claims and electronic health records, to evaluate the effects of medical products have become commonplace. These studies begin by selecting a particular study design, such as a case control, cohort, or self-controlled design, and different authors can and do choose different designs for the same clinical question. Furthermore, published papers invariably report the study design but do not discuss the rationale for the specific choice. Studies of the same clinical question with different designs, however, can generate different results, sometimes with strikingly different implications. Even within a specific study design, authors make many different analytic choices and these too can profoundly impact results. In this paper, we systematically study heterogeneity due to the type of study design and due to analytic choices within study design. Methods and findings: We conducted our analysis in 10 observational healthcare databases but mostly present our results in the context of the GE Centricity EMR database, an electronic health record database containing data for 11.2 million lives. We considered the impact of three different study design choices on estimates of associations between bisphosphonates and four particular health outcomes for which there is no evidence of an association. We show that applying alternative study designs can yield discrepant results, in terms of direction and significance of association. We also highlight that while traditional univariate sensitivity analysis may not show substantial variation, systematic assessment of all analytical choices within a study design can yield inconsistent results ranging from statistically significant decreased risk to statistically significant increased risk. Our findings show that clinical studies using observational databases can be sensitive both to study design choices and to specific analytic choices within study design. Conclusion: More attention is needed to consider how design choices may be impacting results and, when possible, investigators should examine a wide array of possible choices to confirm that significant findings are consistently identified. PMID:25083251

Empirical studies of design software: Implications for software engineering environments

NASA Technical Reports Server (NTRS)

Krasner, Herb

1988-01-01

The empirical studies team of MCC's Design Process Group conducted three studies in 1986-87 in order to gather data on professionals designing software systems in a range of situations. The first study (the Lift Experiment) used thinking aloud protocols in a controlled laboratory setting to study the cognitive processes of individual designers. The second study (the Object Server Project) involved the observation, videotaping, and data collection of a design team of a medium-sized development project over several months in order to study team dynamics. The third study (the Field Study) involved interviews with the personnel from 19 large development projects in the MCC shareholders in order to study how the process of design is affected by organizationl and project behavior. The focus of this report will be on key observations of design process (at several levels) and their implications for the design of environments.

Study/Experimental/Research Design: Much More Than Statistics

PubMed Central

Knight, Kenneth L.

2010-01-01

Abstract Context: The purpose of study, experimental, or research design in scientific manuscripts has changed significantly over the years. It has evolved from an explanation of the design of the experiment (ie, data gathering or acquisition) to an explanation of the statistical analysis. This practice makes “Methods” sections hard to read and understand. Objective: To clarify the difference between study design and statistical analysis, to show the advantages of a properly written study design on article comprehension, and to encourage authors to correctly describe study designs. Description: The role of study design is explored from the introduction of the concept by Fisher through modern-day scientists and the AMA Manual of Style. At one time, when experiments were simpler, the study design and statistical design were identical or very similar. With the complex research that is common today, which often includes manipulating variables to create new variables and the multiple (and different) analyses of a single data set, data collection is very different than statistical design. Thus, both a study design and a statistical design are necessary. Advantages: Scientific manuscripts will be much easier to read and comprehend. A proper experimental design serves as a road map to the study methods, helping readers to understand more clearly how the data were obtained and, therefore, assisting them in properly analyzing the results. PMID:20064054

How to Construct a Mixed Methods Research Design.

PubMed

Schoonenboom, Judith; Johnson, R Burke

2017-01-01

This article provides researchers with knowledge of how to design a high quality mixed methods research study. To design a mixed study, researchers must understand and carefully consider each of the dimensions of mixed methods design, and always keep an eye on the issue of validity. We explain the seven major design dimensions: purpose, theoretical drive, timing (simultaneity and dependency), point of integration, typological versus interactive design approaches, planned versus emergent design, and design complexity. There also are multiple secondary dimensions that need to be considered during the design process. We explain ten secondary dimensions of design to be considered for each research study. We also provide two case studies showing how the mixed designs were constructed.

Design Study for A Low-Cost LH2 Turbopump

NASA Technical Reports Server (NTRS)

Japikse, David; Baines, Nicholas; Platt, Michael J.

2000-01-01

A preliminary design study, focusing on potential component selections and design for manufacturing and assembly (DFMAR1) analysis, is presented in this study. The investigation focused on a nominal cost liquid hydrogen turbopump suitable for a private launch class vehicle. Utilizing a "turbocharger-like" design philosophy, preliminary feasibility studies of the basic pump design class, the rotordynamic design class, and the turbine design class were conducted with associated DFMA evaluations. Reasonable cost levels and sensible levels of product assurance have been established.

Urban Environment Development based on Universal Design Principles

NASA Astrophysics Data System (ADS)

Harsritanto, Bangun Ir

2018-02-01

Universal Design is a design which facilitated full range of human diversity. By applying Universal design principles, urban environment can be more functional and more user-friendly for everyone. This study examined five urban streets of South Korea as a country experienced on developing various urban street designs based on universal design. This study aimed to examine and compare the South Korea cases using seven principles of universal design. The research methods of this study are literature study, case study, and site observation. The results of this study are: South Korea cases are good practices, urgency of implementing the direction into local regulations; and change of urban development paradigm.

Collaboration between Industrial Designers and Design Engineers - Comparing the Understanding of Design Intent.

PubMed

Laursen, Esben Skov; Møller, Louise

2015-01-01

This paper describes a case study comparing the understanding of design intent between industrial designers and design engineers. The study is based on the hypothesis that it is not all aspects of the design intent that are equally difficult to share between industrial designers and design engineers in the product development process. The study builds on five semi-structured interviews, where two industrial designers and three design engineers were interviewed about different aspects of the design intent. Based on our results, there seem to be indications that the more complex and abstract elements of industrial design knowledge such as the meaning, semantics, values, emotions and social aspects of the product are less shared by the design engineers. Moreover, the results also indicate that the different aspects of the design intent are perceived separately, rather than as part of a whole by the design engineers. The connection between the different aspects of the design intent is not shared between the industrial designer and design engineer making the shared knowledge less meaningful to the design engineers. The results of this study cannot be claimed to be conclusive due to the limited empirical material. Further investigation and analytically richer data are required in order to verify and broaden the findings. More case studies have therefore been planned in order to understand the area better.

The case-control design in veterinary sciences: A survey.

PubMed

Cullen, Jonah N; Sargeant, Jan M; Makielski, Kelly M; O'Connor, Annette M

2016-11-01

The case-control study design is deceptively simple. However, many design considerations influence the estimated effect measure. An investigation of case-control studies in the human health literature suggested that some of these considerations are not described in reports of case-control studies. Our hypothesis was that the majority of veterinary studies labeled as case-controls would be incident density designs, and many would not interpret the effect measure obtained from those studies as the rate ratio rather than the odds ratio. Reference databases were searched for author-designated case-control studies. A survey of 100 randomly selected studies was conducted to examine the different design options described and estimated effect measures. Of the 100 author-identified case-control studies, 83 assessed an exposure-outcome association and, of those, only 54 (65.1%) sampled the study population based on an outcome and would thus be considered case-control designs. Twelve studies were incidence density designs but none used this terminology. Of the studies that reported an odds ratio as the effect measure, none reported on additional considerations that would have enabled a more interpretable result. This survey indicated many case-control-labeled studies were not case-control designs and among case-control studies, key design aspects were not often described. The absence of information about study design elements and underlying assumptions in case-control studies limits the ability to establish the effect measured by the study and the evidentiary value of the study might be underestimated. Copyright © 2016 Elsevier B.V. All rights reserved.

Power Systems Design and Studies | Grid Modernization | NREL

Science.gov Websites

Design and Studies Power Systems Design and Studies NREL develops new tools, algorithms, and market design and performance evaluations; and planning, operations, and protection studies. Photo of two researchers looking at a screen showing a distribution grid map Current design and planning tools for the

How system designers think: a study of design thinking in human factors engineering.

PubMed

Papantonopoulos, Sotiris

2004-11-01

The paper presents a descriptive study of design thinking in human factors engineering. The objective of the study is to analyse the role of interpretation in design thinking and the role of design practice in guiding interpretation. The study involved 10 system designers undertaking the allocation of cognitive functions in three production planning and control task scenarios. Allocation decisions were recorded and verbal protocols of the design process were collected to elicit the subjects' thought processes. Verbal protocol analysis showed that subjects carried out the design of cognitive task allocation as a problem of applying a selected automation technology from their initial design deliberations. This design strategy stands in contrast to the predominant view of system design that stipulates that user requirements should be thoroughly analysed prior to making any decisions about technology. Theoretical frameworks from design research and ontological design showed that the system design process may be better understood by recognizing the role of design hypotheses in system design, as well as the diverse interactions between interpretation and practice, means and ends, and design practice and the designer's pre-understanding which shape the design process. Ways to balance the bias exerted on the design process were discussed.

A Parallel Trade Study Architecture for Design Optimization of Complex Systems

NASA Technical Reports Server (NTRS)

Kim, Hongman; Mullins, James; Ragon, Scott; Soremekun, Grant; Sobieszczanski-Sobieski, Jaroslaw

2005-01-01

Design of a successful product requires evaluating many design alternatives in a limited design cycle time. This can be achieved through leveraging design space exploration tools and available computing resources on the network. This paper presents a parallel trade study architecture to integrate trade study clients and computing resources on a network using Web services. The parallel trade study solution is demonstrated to accelerate design of experiments, genetic algorithm optimization, and a cost as an independent variable (CAIV) study for a space system application.

Study design in medical research: part 2 of a series on the evaluation of scientific publications.

PubMed

Röhrig, Bernd; du Prel, Jean-Baptist; Blettner, Maria

2009-03-01

The scientific value and informativeness of a medical study are determined to a major extent by the study design. Errors in study design cannot be corrected afterwards. Various aspects of study design are discussed in this article. Six essential considerations in the planning and evaluation of medical research studies are presented and discussed in the light of selected scientific articles from the international literature as well as the authors' own scientific expertise with regard to study design. The six main considerations for study design are the question to be answered, the study population, the unit of analysis, the type of study, the measuring technique, and the calculation of sample size. This article is intended to give the reader guidance in evaluating the design of studies in medical research. This should enable the reader to categorize medical studies better and to assess their scientific quality more accurately.

The active comparator, new user study design in pharmacoepidemiology: historical foundations and contemporary application

PubMed Central

Lund, Jennifer L.; Richardson, David B.; Stürmer, Til

2016-01-01

Better understanding of biases related to selective prescribing of, and adherence to, preventive treatments has led to improvements in the design and analysis of pharmacoepidemiologic studies. One influential development has been the “active comparator, new user” study design, which seeks to emulate the design of a head-to-head randomized controlled trial. In this review, we first discuss biases that may affect pharmacoepidemiologic studies and describe their direction and magnitude in a variety of settings. We then present the historical foundations of the active comparator, new user study design and explain how this design conceptually mitigates biases leading to a paradigm shift in pharmacoepidemiology. We offer practical guidance on the implementation of the study design using administrative databases. Finally, we provide an empirical example in which the active comparator, new user study design addresses biases that have previously impeded pharmacoepidemiologic studies. PMID:26954351

Studies of Plutonium-238 Production at the High Flux Isotope Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lastres, Oscar; Chandler, David; Jarrell, Joshua J

The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) is a versatile 85 MW{sub th}, pressurized, light water-cooled and -moderated research reactor. The core consists of two fuel elements, an inner fuel element (IFE) and an outer fuel element (OFE), each constructed of involute fuel plates containing high-enriched-uranium (HEU) fuel ({approx}93 wt% {sup 235}U/U) in the form of U{sub 3}O{sub 8} in an Al matrix and encapsulated in Al-6061 clad. An over-moderated flux trap is located in the center of the core, a large beryllium reflector is located on the outside of the core, and two controlmore » elements (CE) are located between the fuel and the reflector. The flux trap and reflector house numerous experimental facilities which are used for isotope production, material irradiation, and cold/thermal neutron scattering. Over the past five decades, the US Department of Energy (DOE) and its agencies have been producing radioisotope power systems used by the National Aeronautics and Space Administration (NASA) for unmanned, long-term space exploration missions. Plutonium-238 is used to power Radioisotope Thermoelectric Generators (RTG) because it has a very long half-life (t{sub 1/2} {approx} 89 yr.) and it generates about 0.5 watts/gram when it decays via alpha emission. Due to the recent shortage and uncertainty of future production, the DOE has proposed a plan to the US Congress to produce {sup 238}Pu by irradiating {sup 237}Np as early as in fiscal year 2011. An annual production rate of 1.5 to 2.0 kg of {sup 238}Pu is expected to satisfy these needs and could be produced in existing national nuclear facilities like HFIR and the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Reactors at the Savannah River Site were used in the past for {sup 238}Pu production but were shut down after the last production in 1988. The nation's {sup 237}Np inventory is currently stored at INL. A plan for producing {sup 238}Pu at US research reactor facilities such as the High Flux Isotope Reactor at ORNL has been initiated by the US DOE and NASA for space exploration needs. Two Monte Carlo-based depletion codes, TRITON (ORNL) and VESTA (IRSN), were used to study the {sup 238}Pu production rates with varying target configurations in a typical HFIR fuel cycle. Preliminary studies have shown that approximately 11 grams and within 15 to 17 grams of {sup 238}Pu could be produced in the first irradiation cycle in one small and one large VXF facility, respectively, when irradiating fresh target arrays as those herein described. Important to note is that in this study we discovered that small differences in assumptions could affect the production rates of Pu-238 observed. The exact flux at a specific target location can have a significant impact upon production, so any differences in how the control elements are modeled as a function of exposure, will also cause differences in production rates. In fact, the surface plot of the large VXF target Pu-238 production shown in Figure 3 illustrates that the pins closest to the core can potentially have production rates as high as 3 times those of pins away from the core, thus implying that a cycle-to-cycle rotation of the targets may be well advised. A methodology for generating spatially-dependent, multi-group self-shielded cross sections and flux files with the KENO and CENTRM codes has been created so that standalone ORIGEN-S inputs can be quickly constructed to perform a variety of {sup 238}Pu production scenarios, i.e. combinations of the number of arrays loaded and the number of irradiation cycles. The studies herein shown with VESTA and TRITON/KENO will be used to benchmark the standalone ORIGEN.« less

Instructional Design: Case Studies in Communities of Practice

ERIC Educational Resources Information Center

Keppell, Michael, Ed.

2007-01-01

"Instructional Design: Case Studies in Communities of Practice" documents real-world experiences of instructional designers and staff developers who work in communities of practice. "Instructional Design: Case Studies in Communities of Practice" explains the strategies and heuristics used by instructional designers when working…

Variation in Research Designs Used to Test the Effectiveness of Dissemination and Implementation Strategies: A Review.

PubMed

Mazzucca, Stephanie; Tabak, Rachel G; Pilar, Meagan; Ramsey, Alex T; Baumann, Ana A; Kryzer, Emily; Lewis, Ericka M; Padek, Margaret; Powell, Byron J; Brownson, Ross C

2018-01-01

The need for optimal study designs in dissemination and implementation (D&I) research is increasingly recognized. Despite the wide range of study designs available for D&I research, we lack understanding of the types of designs and methodologies that are routinely used in the field. This review assesses the designs and methodologies in recently proposed D&I studies and provides resources to guide design decisions. We reviewed 404 study protocols published in the journal Implementation Science from 2/2006 to 9/2017. Eligible studies tested the efficacy or effectiveness of D&I strategies (i.e., not effectiveness of the underlying clinical or public health intervention); had a comparison by group and/or time; and used ≥1 quantitative measure. Several design elements were extracted: design category (e.g., randomized); design type [e.g., cluster randomized controlled trial (RCT)]; data type (e.g., quantitative); D&I theoretical framework; levels of treatment assignment, intervention, and measurement; and country in which the research was conducted. Each protocol was double-coded, and discrepancies were resolved through discussion. Of the 404 protocols reviewed, 212 (52%) studies tested one or more implementation strategy across 208 manuscripts, therefore meeting inclusion criteria. Of the included studies, 77% utilized randomized designs, primarily cluster RCTs. The use of alternative designs (e.g., stepped wedge) increased over time. Fewer studies were quasi-experimental (17%) or observational (6%). Many study design categories (e.g., controlled pre-post, matched pair cluster design) were represented by only one or two studies. Most articles proposed quantitative and qualitative methods (61%), with the remaining 39% proposing only quantitative. Half of protocols (52%) reported using a theoretical framework to guide the study. The four most frequently reported frameworks were Consolidated Framework for Implementing Research and RE-AIM ( n  = 16 each), followed by Promoting Action on Research Implementation in Health Services and Theoretical Domains Framework ( n  = 12 each). While several novel designs for D&I research have been proposed (e.g., stepped wedge, adaptive designs), the majority of the studies in our sample employed RCT designs. Alternative study designs are increasing in use but may be underutilized for a variety of reasons, including preference of funders or lack of awareness of these designs. Promisingly, the prevalent use of quantitative and qualitative methods together reflects methodological innovation in newer D&I research.

Public Interest in Medical Research Participation: Does It Matter if Patients or Community Members Have Helped Design the Study?

PubMed

Cobb, Enesha M; Gebremariam, Achamyeleh; Singer, Dianne; Davis, Matthew M

2015-10-01

We determined national levels of public participation in medical research study design. We compared public interest in medical research participation (MRP) in studies overall, versus studies explicitly designed with public involvement. Cross-sectional household survey of US population in June 2013. Descriptive statistics estimated participation in medical research study design. Chi-square test compared levels of interest in MRP if respondent knew patients or community members helped design the study. Of 2,048 respondents (participation rate 60%), 5% knew someone who had helped design a medical research study. There was no association between having known someone or personal participation in study design and willingness to engage in MRP. Although the overall proportion of respondents who would consider MRP initially (51%) was similar to the proportion who would consider MRP with community member involvement in study design (49%), the changes in respondents' views across the different scenarios were significantly greater than what would have been expected by chance. We found similar levels of interest in MRP whether or not the public is involved in medical research study design. This finding may indicate that public involvement in study design, like community-based participatory research, may not affect overall rates of MRP. © 2015 Wiley Periodicals, Inc.

Designing a Pediatric Study for an Antimalarial Drug by Using Information from Adults

PubMed Central

Jullien, Vincent; Samson, Adeline; Guedj, Jérémie; Kiechel, Jean-René; Zohar, Sarah; Comets, Emmanuelle

2015-01-01

The objectives of this study were to design a pharmacokinetic (PK) study by using information about adults and evaluate the robustness of the recommended design through a case study of mefloquine. PK data about adults and children were available from two different randomized studies of the treatment of malaria with the same artesunate-mefloquine combination regimen. A recommended design for pediatric studies of mefloquine was optimized on the basis of an extrapolated model built from adult data through the following approach. (i) An adult PK model was built, and parameters were estimated by using the stochastic approximation expectation-maximization algorithm. (ii) Pediatric PK parameters were then obtained by adding allometry and maturation to the adult model. (iii) A D-optimal design for children was obtained with PFIM by assuming the extrapolated design. Finally, the robustness of the recommended design was evaluated in terms of the relative bias and relative standard errors (RSE) of the parameters in a simulation study with four different models and was compared to the empirical design used for the pediatric study. Combining PK modeling, extrapolation, and design optimization led to a design for children with five sampling times. PK parameters were well estimated by this design with few RSE. Although the extrapolated model did not predict the observed mefloquine concentrations in children very accurately, it allowed precise and unbiased estimates across various model assumptions, contrary to the empirical design. Using information from adult studies combined with allometry and maturation can help provide robust designs for pediatric studies. PMID:26711749

Mariner Jupiter/Saturn 1977 infrared interferometer spectrometer (MJS' 77) design study

NASA Technical Reports Server (NTRS)

1974-01-01

A design study of the Infrared Interferometer Spectrometer and Radiometer (IRIS) instrument for the Mariner Jupiter/Saturn 1977 mission was conducted. The objective of the study was to investigate a number a potential problem areas identified in previous studies and to develop the instrument system designs along the lines providing for the optimum performance obtainable with the allowable budgets. The considerations for the optical design, mechanical design, and electronic design are examined.

Concentrator enhanced solar arrays design study

NASA Technical Reports Server (NTRS)

Lott, D. R.

1978-01-01

The analysis and preliminary design of a 25 kW concentrator enhanced lightweight flexible solar array are presented. The study was organized into five major tasks: (1) assessment and specification of design requirements; (2) mechanical design; (3) electric design; (4) concentrator design; and (5) cost projection. The tasks were conducted in an iterative manner so as to best derive a baseline design selection. The objectives of the study are discussed and comparative configurations and mass data on the SEP (Solar Electric Propulsion) array design, concentrator design options and configuration/mass data on the selected concentrator enhanced solar array baseline design are presented. Design requirements supporting design analysis and detailed baseline design data are discussed. The results of the cost projection analysis and new technology are also discussed.

Empirical studies of software design: Implications for SSEs

NASA Technical Reports Server (NTRS)

Krasner, Herb

1988-01-01

Implications for Software Engineering Environments (SEEs) are presented in viewgraph format for characteristics of projects studied; significant problems and crucial problem areas in software design for large systems; layered behavioral model of software processes; implications of field study results; software project as an ecological system; results of the LIFT study; information model of design exploration; software design strategies; results of the team design study; and a list of publications.

Advanced turbocharger design study program

NASA Technical Reports Server (NTRS)

Culy, D. G.; Heldenbrand, R. W.; Richardson, N. R.

1984-01-01

The advanced Turbocharger Design Study consisted of: (1) the evaluation of three advanced engine designs to determine their turbocharging requirements, and of technologies applicable to advanced turbocharger designs; (2) trade-off studies to define a turbocharger conceptual design and select the engine with the most representative requirements for turbocharging; (3) the preparation of a turbocharger conceptual design for the Curtiss Wright RC2-32 engine selected in the trade-off studies; and (4) the assessment of market impact and the preparation of a technology demonstration plan for the advanced turbocharger.

Complexity in Design-Driven Innovation: A Case Study of Knowledge Transfer Flow in Subsea Seismic Sensor Technology and Design Education

ERIC Educational Resources Information Center

Pavel, Nenad; Berg, Arild

2015-01-01

To the extent previously claimed, concept exploration is not the key to product innovation. However, companies that are design-focused are twice as innovative as those that are not. To study design-driven innovation and its occurrence in design education, two case studies are conducted. The first is an example of design practice which includes…

Design Fixation in the Wild: Design Environments and Their Influence on Fixation

ERIC Educational Resources Information Center

Youmans, Robert J.

2011-01-01

Many studies of design fixation ask designers to work in controlled laboratory or classroom environments, but innovative design work frequently occurs in dynamic, social environments. The two studies reviewed in this paper investigated how three independent variables likely to be present in many design environments affect design fixation. The…

Optimum study designs.

PubMed

Gu, C; Rao, D C

2001-01-01

Because simplistic designs will lead to prohibitively large sample sizes, the optimization of genetic study designs is critical for successfully mapping genes for complex diseases. Creative designs are necessary for detecting and amplifying the usually weak signals for complex traits. Two important outcomes of a study design--power and resolution--are implicitly tied together by the principle of uncertainty. Overemphasis on either one may lead to suboptimal designs. To achieve optimality for a particular study, therefore, practical measures such as cost-effectiveness must be used to strike a balance between power and resolution. In this light, the myriad of factors involved in study design can be checked for their effects on the ultimate outcomes, and the popular existing designs can be sorted into building blocks that may be useful for particular situations. It is hoped that imaginative construction of novel designs using such building blocks will lead to enhanced efficiency in finding genes for complex human traits.

Teaching Strategies to Promote Concept Learning by Design Challenges

ERIC Educational Resources Information Center

Van Breukelen, Dave; Van Meel, Adrianus; De Vries, Marc

2017-01-01

Background: This study is the second study of a design-based research, organised around four studies, that aims to improve student learning, teaching skills and teacher training concerning the design-based learning approach called Learning by Design (LBD). Purpose: LBD uses the context of design challenges to learn, among other things, science.…

77 FR 28883 - Cooperative Agreement To Support Innovation in Vaccine Clinical Trial Design and Collaboration in...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-16

... years there has been interest in finding innovative study designs to speed development of promising new... various types of adaptive trial designs and other innovations in clinical study designs. 2. Improving... of study designs, individual risk perception, and vaccination choice. One approach to obtain this...

Active-comparator design and new-user design in observational studies

PubMed Central

Yoshida, Kazuki; Solomon, Daniel H.; Kim, Seoyoung C.

2015-01-01

SUMMARY Over the past decade, an increasing number of observational studies have examined the effectiveness or safety of rheumatoid arthritis treatments. However, unlike randomized controlled trials (RCTs), observational studies of drug effects face methodological challenges including confounding by indication. Two design principles - active comparator design and new user design can help mitigate such challenges in observational studies. To improve validity of study findings, observational studies should be designed in such a way that makes them more closely approximate RCTs. The active comparator design compares the drug of interest to another commonly used agent for the same indication, rather than a ‘non-user’ group. This principle helps select treatment groups similar in treatment indications (both measured and unmeasured characteristics). The new user design includes a cohort of patients from the time of treatment initiation, so that it can assess patients’ pretreatment characteristics and capture all events occurring anytime during follow-up. PMID:25800216

Space Station Furnace Facility. Volume 2: Requirements definition and conceptual design study

NASA Technical Reports Server (NTRS)

1992-01-01

The Space Station Freedom Furnace (SSFF) Project is divided into two phases: phase 1, a definition study phase, and phase 2, a design and development phase. TBE was awarded a research study entitled, 'Space Station Furnace Facility Requirements Definition and Conceptual Design Study' on June 2, 1989. This report addresses the definition study phase only. Phase 2 is to be complete after completion of phase 1. The contract encompassed a requirements definition study and culminated in hardware/facility conceptual designs and hardware demonstration development models to test these conceptual designs. The study was divided into two parts. Part 1 (the basic part of the effort) encompassed preliminary requirements definition and assessment; conceptional design of the SSFF Core; fabrication of mockups; and preparation for the support of a conceptional design review (CoDR). Part 2 (the optional part of the effort) included detailed definition of the engineering and design requirements, as derived from the science requirements; refinement of the conceptual design of the SSFF Core; fabrication and testing of the 'breadboards' or development models; and preparation for and support of a requirements definition review.

75 FR 23775 - Agency Information Collection Activities; Proposed Collection; Comment Request; Experimental...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-04

... for research entitled ``Experimental Study of Patient Information Prototypes.'' This study is designed..., the working group refined several prototypes and designed a study to investigate the usefulness of... Design and Protocol The study is experimental and will have two independent variables in a 3 x 2 design...

The Importance of Considering Differences in Study Design in Network Meta-analysis: An Application Using Anti-Tumor Necrosis Factor Drugs for Ulcerative Colitis.

PubMed

Cameron, Chris; Ewara, Emmanuel; Wilson, Florence R; Varu, Abhishek; Dyrda, Peter; Hutton, Brian; Ingham, Michael

2017-11-01

Adaptive trial designs present a methodological challenge when performing network meta-analysis (NMA), as data from such adaptive trial designs differ from conventional parallel design randomized controlled trials (RCTs). We aim to illustrate the importance of considering study design when conducting an NMA. Three NMAs comparing anti-tumor necrosis factor drugs for ulcerative colitis were compared and the analyses replicated using Bayesian NMA. The NMA comprised 3 RCTs comparing 4 treatments (adalimumab 40 mg, golimumab 50 mg, golimumab 100 mg, infliximab 5 mg/kg) and placebo. We investigated the impact of incorporating differences in the study design among the 3 RCTs and presented 3 alternative methods on how to convert outcome data derived from one form of adaptive design to more conventional parallel RCTs. Combining RCT results without considering variations in study design resulted in effect estimates that were biased against golimumab. In contrast, using the 3 alternative methods to convert outcome data from one form of adaptive design to a format more consistent with conventional parallel RCTs facilitated more transparent consideration of differences in study design. This approach is more likely to yield appropriate estimates of comparative efficacy when conducting an NMA, which includes treatments that use an alternative study design. RCTs based on adaptive study designs should not be combined with traditional parallel RCT designs in NMA. We have presented potential approaches to convert data from one form of adaptive design to more conventional parallel RCTs to facilitate transparent and less-biased comparisons.

Teaching strategies to promote concept learning by design challenges

NASA Astrophysics Data System (ADS)

Van Breukelen, Dave; Van Meel, Adrianus; De Vries, Marc

2017-07-01

Background: This study is the second study of a design-based research, organised around four studies, that aims to improve student learning, teaching skills and teacher training concerning the design-based learning approach called Learning by Design (LBD).

How Differences in Interactions Affect Learning and Development of Design Expertise in the Context of Biomedical Engineering Design

ERIC Educational Resources Information Center

Svihla, Vanessa Lynn

2009-01-01

Authentic design commonly involves teams of designers collaborating on ill-structured problems over extended time periods. Nonetheless, design has been studied extensively in sequestered settings, limiting our understanding of design as process and especially of learning design process. This study addresses potential shortcomings of such studies…

Design and implementation of observational studies to measure disease burden with a focus on stroke.

PubMed

Howard, George; Howard, Virginia J

2018-02-01

Observational epidemiological studies have the dual goals of measuring disease burden and assessing the association between exposures and outcomes. This report focuses on the first of these goals and provides an overview of design considerations of commonly used approaches, specifically community surveillance studies, cross-sectional studies, and longitudinal cohort studies. Each of these designs has strengths and weaknesses, with no study design being superior in all cases. Rather, these designs are complementary to achieve a better understanding of the burden of stroke.

Management Design Theories

NASA Astrophysics Data System (ADS)

Pries-Heje, Jan; Baskerville, Richard L.

This paper elaborates a design science approach for management planning anchored to the concept of a management design theory. Unlike the notions of design theories arising from information systems, management design theories can appear as a system of technological rules, much as a system of hypotheses or propositions can embody scientific theories. The paper illus trates this form of management design theories with three grounded cases. These grounded cases include a software process improvement study, a user involvement study, and an organizational change study. Collectively these studies demonstrate how design theories founded on technological rules can not only improve the design of information systems, but that these concepts have great practical value for improving the framing of strategic organi zational design decisions about such systems. Each case is either grounded in an empirical sense, that is to say, actual practice, or it is grounded to practices described extensively in the practical literature. Such design theories will help managers more easily approach complex, strategic decisions.

Study and design of cryogenic propellant acquisition systems. Volume 1: Design studies

NASA Technical Reports Server (NTRS)

Burge, G. W.; Blackmon, J. B.

1973-01-01

An in-depth study and selection of practical propellant surface tension acquisition system designs for two specific future cryogenic space vehicles, an advanced cryogenic space shuttle auxiliary propulsion system and an advanced space propulsion module is reported. A supporting laboratory scale experimental program was also conducted to provide design information critical to concept finalization and selection. Designs using localized pressure isolated surface tension screen devices were selected for each application and preliminary designs were generated. Based on these designs, large scale acquisition prototype hardware was designed and fabricated to be compatible with available NASA-MSFC feed system hardware.

Experiences with an adaptive design for a dose-finding study in patients with osteoarthritis.

PubMed

Miller, Frank; Björnsson, Marcus; Svensson, Ola; Karlsten, Rolf

2014-03-01

Dose-finding studies in non-oncology areas are usually conducted in Phase II of the development process of a new potential medicine and it is key to choose a good design for such a study, as the results will decide if and how to proceed to Phase III. The present article has focus on the design of a dose-finding study for pain in osteoarthritis patients treated with the TRPV1 antagonist AZD1386. We describe different design alternatives in the planning of this study, the reasoning for choosing the adaptive design and experiences with conduct and interim analysis. Three alternatives were proposed: one single dose-finding study with parallel design, a programme with a smaller Phase IIa study followed by a Phase IIb dose-finding study, and an adaptive dose-finding study. We describe these alternatives in detail and explain why the adaptive design was chosen for the study. We give insights in design aspects of the adaptive study, which need to be pre-planned, like interim decision criteria, statistical analysis method and setup of a Data Monitoring Committee. Based on the interim analysis it was recommended to stop the study for futility since AZD1386 showed no significant pain decrease based on the primary variable. We discuss results and experiences from the conduct of the study with the novel design approach. Huge cost savings have been done compared to if the option with one dose-finding design for Phase II had been chosen. However, we point out several challenges with this approach. Copyright © 2014 Elsevier Inc. All rights reserved.

Interpretive Research Aiming at Theory Building: Adopting and Adapting the Case Study Design

ERIC Educational Resources Information Center

Diaz Andrade, Antonio

2009-01-01

Although the advantages of case study design are widely recognised, its original positivist underlying assumptions may mislead interpretive researchers aiming at theory building. The paper discusses the limitations of the case study design for theory building and explains how grounded theory systemic process adds to the case study design. The…

Development and Formative Evaluation of Multimedia Case Studies for Instructional Design and Technology Students

ERIC Educational Resources Information Center

Sugar, William

2014-01-01

This study describes the development of three case studies that included a combination of multimedia production and instructional design skills within a particular setting. These case studies incorporated real-life incidents from 47 professional instructional designers. These instructional designers described a total of 146 activities involving…

Understanding Gender, Creativity, and Entrepreneurial Intentions

ERIC Educational Resources Information Center

Smith, Ronda Marie; Sardeshmukh, Shruti R.; Combs, Gwendolyn M.

2016-01-01

Purpose: The purpose of this paper is to explore the complex relationships between gender and entrepreneurial intentions. Design/methodology/approach: This paper uses a two study design where the second study is a constructive replication of the first study. The first study uses a cross-sectional design, while the second uses a design where data…

Structural Design of Ares V Interstage Composite Structure

NASA Technical Reports Server (NTRS)

Sleigh, David W.; Sreekantamurthy, Thammaiah; Kosareo, Daniel N.; Martin, Robert A.; Johnson, Theodore F.

2011-01-01

Preliminary and detailed design studies were performed to mature composite structural design concepts for the Ares V Interstage structure as a part of NASA s Advanced Composite Technologies Project. Aluminum honeycomb sandwich and hat-stiffened composite panel structural concepts were considered. The structural design and analysis studies were performed using HyperSizer design sizing software and MSC Nastran finite element analysis software. System-level design trade studies were carried out to predict weight and margins of safety for composite honeycomb-core sandwich and composite hat-stiffened skin design concepts. Details of both preliminary and detailed design studies are presented in the paper. For the range of loads and geometry considered in this work, the hat-stiffened designs were found to be approximately 11-16 percent lighter than the sandwich designs. A down-select process was used to choose the most favorable structural concept based on a set of figures of merit, and the honeycomb sandwich design was selected as the best concept based on advantages in manufacturing cost.

A study of commuter airplane design optimization

NASA Technical Reports Server (NTRS)

Roskam, J.; Wyatt, R. D.; Griswold, D. A.; Hammer, J. L.

1977-01-01

Problems of commuter airplane configuration design were studied to affect a minimization of direct operating costs. Factors considered were the minimization of fuselage drag, methods of wing design, and the estimated drag of an airplane submerged in a propellor slipstream; all design criteria were studied under a set of fixed performance, mission, and stability constraints. Configuration design data were assembled for application by a computerized design methodology program similar to the NASA-Ames General Aviation Synthesis Program.

Radioisotope Electric Propulsion Missions Utilizing a Common Spacecraft Design

NASA Technical Reports Server (NTRS)

Fiehler, Douglas; Oleson, Steven

2004-01-01

A study was conducted that shows how a single Radioisotope Electric Propulsion (REP) spacecraft design could be used for various missions throughout the solar system. This spacecraft design is based on a REP feasibility design from a study performed by NASA Glenn Research Center and the Johns Hopkins University Applied Physics Laboratory. The study also identifies technologies that need development to enable these missions. The mission baseline for the REP feasibility design study is a Trojan asteroid orbiter. This mission sends an REP spacecraft to Jupiter s leading Lagrange point where it would orbit and examine several Trojan asteroids. The spacecraft design from the REP feasibility study would also be applicable to missions to the Centaurs, and through some change of payload configuration, could accommodate a comet sample-return mission. Missions to small bodies throughout the outer solar system are also within reach of this spacecraft design. This set of missions, utilizing the common REP spacecraft design, is examined and required design modifications for specific missions are outlined.

Statistical inference for the additive hazards model under outcome-dependent sampling.

PubMed

Yu, Jichang; Liu, Yanyan; Sandler, Dale P; Zhou, Haibo

2015-09-01

Cost-effective study design and proper inference procedures for data from such designs are always of particular interests to study investigators. In this article, we propose a biased sampling scheme, an outcome-dependent sampling (ODS) design for survival data with right censoring under the additive hazards model. We develop a weighted pseudo-score estimator for the regression parameters for the proposed design and derive the asymptotic properties of the proposed estimator. We also provide some suggestions for using the proposed method by evaluating the relative efficiency of the proposed method against simple random sampling design and derive the optimal allocation of the subsamples for the proposed design. Simulation studies show that the proposed ODS design is more powerful than other existing designs and the proposed estimator is more efficient than other estimators. We apply our method to analyze a cancer study conducted at NIEHS, the Cancer Incidence and Mortality of Uranium Miners Study, to study the risk of radon exposure to cancer.

Statistical inference for the additive hazards model under outcome-dependent sampling

PubMed Central

Yu, Jichang; Liu, Yanyan; Sandler, Dale P.; Zhou, Haibo

2015-01-01

Cost-effective study design and proper inference procedures for data from such designs are always of particular interests to study investigators. In this article, we propose a biased sampling scheme, an outcome-dependent sampling (ODS) design for survival data with right censoring under the additive hazards model. We develop a weighted pseudo-score estimator for the regression parameters for the proposed design and derive the asymptotic properties of the proposed estimator. We also provide some suggestions for using the proposed method by evaluating the relative efficiency of the proposed method against simple random sampling design and derive the optimal allocation of the subsamples for the proposed design. Simulation studies show that the proposed ODS design is more powerful than other existing designs and the proposed estimator is more efficient than other estimators. We apply our method to analyze a cancer study conducted at NIEHS, the Cancer Incidence and Mortality of Uranium Miners Study, to study the risk of radon exposure to cancer. PMID:26379363

Making intelligent systems team players: Additional case studies

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Schreckenghost, Debra L.; Rhoads, Ron W.

1993-01-01

Observations from a case study of intelligent systems are reported as part of a multi-year interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. A series of studies were conducted to investigate issues in designing intelligent fault management systems in aerospace applications for effective human-computer interaction. The results of the initial study are documented in two NASA technical memoranda: TM 104738 Making Intelligent Systems Team Players: Case Studies and Design Issues, Volumes 1 and 2; and TM 104751, Making Intelligent Systems Team Players: Overview for Designers. The objective of this additional study was to broaden the investigation of human-computer interaction design issues beyond the focus on monitoring and fault detection in the initial study. The results of this second study are documented which is intended as a supplement to the original design guidance documents. These results should be of interest to designers of intelligent systems for use in real-time operations, and to researchers in the areas of human-computer interaction and artificial intelligence.

Guidelines for the Design and Conduct of Clinical Studies in Knee Articular Cartilage Repair

PubMed Central

Mithoefer, Kai; Saris, Daniel B.F.; Farr, Jack; Kon, Elizaveta; Zaslav, Kenneth; Cole, Brian J.; Ranstam, Jonas; Yao, Jian; Shive, Matthew; Levine, David; Dalemans, Wilfried; Brittberg, Mats

2011-01-01

Objective: To summarize current clinical research practice and develop methodological standards for objective scientific evaluation of knee cartilage repair procedures and products. Design: A comprehensive literature review was performed of high-level original studies providing information relevant for the design of clinical studies on articular cartilage repair in the knee. Analysis of cartilage repair publications and synopses of ongoing trials were used to identify important criteria for the design, reporting, and interpretation of studies in this field. Results: Current literature reflects the methodological limitations of the scientific evidence available for articular cartilage repair. However, clinical trial databases of ongoing trials document a trend suggesting improved study designs and clinical evaluation methodology. Based on the current scientific information and standards of clinical care, detailed methodological recommendations were developed for the statistical study design, patient recruitment, control group considerations, study endpoint definition, documentation of results, use of validated patient-reported outcome instruments, and inclusion and exclusion criteria for the design and conduct of scientifically sound cartilage repair study protocols. A consensus statement among the International Cartilage Repair Society (ICRS) and contributing authors experienced in clinical trial design and implementation was achieved. Conclusions: High-quality clinical research methodology is critical for the optimal evaluation of current and new cartilage repair technologies. In addition to generally applicable principles for orthopedic study design, specific criteria and considerations apply to cartilage repair studies. Systematic application of these criteria and considerations can facilitate study designs that are scientifically rigorous, ethical, practical, and appropriate for the question(s) being addressed in any given cartilage repair research project. PMID:26069574

Design principles for simulation games for learning clinical reasoning: A design-based research approach.

PubMed

Koivisto, J-M; Haavisto, E; Niemi, H; Haho, P; Nylund, S; Multisilta, J

2018-01-01

Nurses sometimes lack the competence needed for recognising deterioration in patient conditions and this is often due to poor clinical reasoning. There is a need to develop new possibilities for learning this crucial competence area. In addition, educators need to be future oriented; they need to be able to design and adopt new pedagogical innovations. The purpose of the study is to describe the development process and to generate principles for the design of nursing simulation games. A design-based research methodology is applied in this study. Iterative cycles of analysis, design, development, testing and refinement were conducted via collaboration among researchers, educators, students, and game designers. The study facilitated the generation of reusable design principles for simulation games to guide future designers when designing and developing simulation games for learning clinical reasoning. This study makes a major contribution to research on simulation game development in the field of nursing education. The results of this study provide important insights into the significance of involving nurse educators in the design and development process of educational simulation games for the purpose of nursing education. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sediment Export from Forest Road Turn-outs: A Study Design and Preliminary Results

Treesearch

Johnny M. Grace

1998-01-01

This paper reports the design and preliminary results of a study that evaluates the effects of commonly prescribed forest road runoff control treatments. A study design which utilizes runoff samplers, runoff diversion walls, sediment filter bags, and erosion stakes to evaluate sediment transport through runoff control treatments is documented. The study design will...

Making a Case for a Blended Approach: The Need for The Design-Based Case Study

ERIC Educational Resources Information Center

Deaton, Cynthia C. M.; Malloy, Jacquelynn A.

2017-01-01

Design-based case studies address research questions that involve instructional innovations within a bounded system. This blend of case study and design-based research provides a systematic approach to examining instructional innovations that are bounded by perspective, context, and time. Design-based case studies provide a framework for engaging…

Communications Style Guide. Fourth Edition

DTIC Science & Technology

2010-08-01

ethnography , phenomenological study , grounded theory study , and content analysis. You want to choose your research design based on your topic and how you...accessed 27 May 2008). 38 design or an historical research design. There are five basic types of qualitative research designs: case study ...suits the purpose of your study . Generally, while a student of MCU, you will use qualitative research

Development and evaluation of a study design typology for human research.

PubMed

Carini, Simona; Pollock, Brad H; Lehmann, Harold P; Bakken, Suzanne; Barbour, Edward M; Gabriel, Davera; Hagler, Herbert K; Harper, Caryn R; Mollah, Shamim A; Nahm, Meredith; Nguyen, Hien H; Scheuermann, Richard H; Sim, Ida

2009-11-14

A systematic classification of study designs would be useful for researchers, systematic reviewers, readers, and research administrators, among others. As part of the Human Studies Database Project, we developed the Study Design Typology to standardize the classification of study designs in human research. We then performed a multiple observer masked evaluation of active research protocols in four institutions according to a standardized protocol. Thirty-five protocols were classified by three reviewers each into one of nine high-level study designs for interventional and observational research (e.g., N-of-1, Parallel Group, Case Crossover). Rater classification agreement was moderately high for the 35 protocols (Fleiss' kappa = 0.442) and higher still for the 23 quantitative studies (Fleiss' kappa = 0.463). We conclude that our typology shows initial promise for reliably distinguishing study design types for quantitative human research.

Designing Studies That Would Address the Multilayered Nature of Health Care

PubMed Central

Pennell, Michael; Rhoda, Dale; Hade, Erinn M.; Paskett, Electra D.

2010-01-01

We review design and analytic methods available for multilevel interventions in cancer research with particular attention to study design, sample size requirements, and potential to provide statistical evidence for causal inference. The most appropriate methods will depend on the stage of development of the research and whether randomization is possible. Early on, fractional factorial designs may be used to screen intervention components, particularly when randomization of individuals is possible. Quasi-experimental designs, including time-series and multiple baseline designs, can be useful once the intervention is designed because they require few sites and can provide the preliminary evidence to plan efficacy studies. In efficacy and effectiveness studies, group-randomized trials are preferred when randomization is possible and regression discontinuity designs are preferred otherwise if assignment based on a quantitative score is possible. Quasi-experimental designs may be used, especially when combined with recent developments in analytic methods to reduce bias in effect estimates. PMID:20386057

A Cross-Sectional Analysis of Publication Types in Quality Improvement Journals.

PubMed

Wong, Christopher J; White, Andrew A; Merel, Susan E; Brock, Douglas M; Staiger, Thomas O

2016-07-01

Despite widespread engagement in quality improvement activities, little is known about the designs of studies currently published in quality improvement journals. This study's goal is to establish the prevalence of the types of research conducted in articles published in journals dedicated to quality improvement. A cross-sectional analysis was performed of 145 research articles published in 11 quality improvement journals in 2011. The majority of study designs were considered pre-experimental (95%), with a small percentage of quasi-experimental and experimental designs. Of the studies that reported the results of an intervention (n = 60), the most common research designs were pre-post studies (33%) and case studies (25%). There were few randomized controlled trials or quasi-experimental study designs (12% of intervention studies). These results suggest that there are opportunities for increased use of quasi-experimental study designs. © The Author(s) 2015.

Recommendations for research design of telehealth studies.

PubMed

Chumbler, Neale R; Kobb, Rita; Brennan, David M; Rabinowitz, Terry

2008-11-01

Properly designed randomized controlled trials (RCTs) are the gold standard to use when examining the effectiveness of telehealth interventions on clinical outcomes. Some published telehealth studies have employed well-designed RCTs. However, such methods are not always feasible and practical in particular settings. This white paper addresses not only the need for properly designed RCTs, but also offers alternative research designs, such as quasi-experimental designs, and statistical techniques that can be employed to rigorously assess the effectiveness of telehealth studies. This paper further offers design and measurement recommendations aimed at and relevant to administrative decision-makers, policymakers, and practicing clinicians.

Simulation methods to estimate design power: an overview for applied research.

PubMed

Arnold, Benjamin F; Hogan, Daniel R; Colford, John M; Hubbard, Alan E

2011-06-20

Estimating the required sample size and statistical power for a study is an integral part of study design. For standard designs, power equations provide an efficient solution to the problem, but they are unavailable for many complex study designs that arise in practice. For such complex study designs, computer simulation is a useful alternative for estimating study power. Although this approach is well known among statisticians, in our experience many epidemiologists and social scientists are unfamiliar with the technique. This article aims to address this knowledge gap. We review an approach to estimate study power for individual- or cluster-randomized designs using computer simulation. This flexible approach arises naturally from the model used to derive conventional power equations, but extends those methods to accommodate arbitrarily complex designs. The method is universally applicable to a broad range of designs and outcomes, and we present the material in a way that is approachable for quantitative, applied researchers. We illustrate the method using two examples (one simple, one complex) based on sanitation and nutritional interventions to improve child growth. We first show how simulation reproduces conventional power estimates for simple randomized designs over a broad range of sample scenarios to familiarize the reader with the approach. We then demonstrate how to extend the simulation approach to more complex designs. Finally, we discuss extensions to the examples in the article, and provide computer code to efficiently run the example simulations in both R and Stata. Simulation methods offer a flexible option to estimate statistical power for standard and non-traditional study designs and parameters of interest. The approach we have described is universally applicable for evaluating study designs used in epidemiologic and social science research.

Simulation methods to estimate design power: an overview for applied research

PubMed Central

2011-01-01

Background Estimating the required sample size and statistical power for a study is an integral part of study design. For standard designs, power equations provide an efficient solution to the problem, but they are unavailable for many complex study designs that arise in practice. For such complex study designs, computer simulation is a useful alternative for estimating study power. Although this approach is well known among statisticians, in our experience many epidemiologists and social scientists are unfamiliar with the technique. This article aims to address this knowledge gap. Methods We review an approach to estimate study power for individual- or cluster-randomized designs using computer simulation. This flexible approach arises naturally from the model used to derive conventional power equations, but extends those methods to accommodate arbitrarily complex designs. The method is universally applicable to a broad range of designs and outcomes, and we present the material in a way that is approachable for quantitative, applied researchers. We illustrate the method using two examples (one simple, one complex) based on sanitation and nutritional interventions to improve child growth. Results We first show how simulation reproduces conventional power estimates for simple randomized designs over a broad range of sample scenarios to familiarize the reader with the approach. We then demonstrate how to extend the simulation approach to more complex designs. Finally, we discuss extensions to the examples in the article, and provide computer code to efficiently run the example simulations in both R and Stata. Conclusions Simulation methods offer a flexible option to estimate statistical power for standard and non-traditional study designs and parameters of interest. The approach we have described is universally applicable for evaluating study designs used in epidemiologic and social science research. PMID:21689447

A study of multiplex data bus techniques for the space shuttle

NASA Technical Reports Server (NTRS)

Kearney, R. J.; Kalange, M. A.

1972-01-01

A comprehensive technology base for the design of a multiplexed data bus subsystem is provided. Extensive analyses, both analytical and empirical, were performed. Subjects covered are classified under the following headings: requirements identification and analysis; transmission media studies; signal design and detection studies; synchronization, timing, and control studies; user-subsystem interface studies; operational reliability analyses; design of candidate data bus configurations; and evaluation of candidate data bus designs.

Bioterror Preparedness-Educational Programming for Military, Public Health and Civilian Medical Personnel

DTIC Science & Technology

2006-10-01

agents. Page 5 of 42 BODY Research Study Design & Survey Development: Study Design We designed a prospective quantitative study looking at the...to bioterrorism to different groups of healthcare learners as follows: This research study design was developed in collaboration with the...PDA based format, and printed monograph based format. The research will focus on the effectiveness of distance learning and self-study methodologies

Marginal biotin deficiency can be induced experimentally in humans using a cost-effective outpatient design.

PubMed

Stratton, Shawna L; Henrich, Cindy L; Matthews, Nell I; Bogusiewicz, Anna; Dawson, Amanda M; Horvath, Thomas D; Owen, Suzanne N; Boysen, Gunnar; Moran, Jeffery H; Mock, Donald M

2012-01-01

To date, marginal, asymptomatic biotin deficiency has been successfully induced experimentally by the use of labor-intensive inpatient designs requiring rigorous dietary control. We sought to determine if marginal biotin deficiency could be induced in humans in a less expensive outpatient design incorporating a self-selected, mixed general diet. We sought to examine the efficacy of three outpatient study designs: two based on oral avidin dosing and one based on a diet high in undenatured egg white for a period of 28 d. In study design 1, participants (n = 4; 3 women) received avidin in capsules with a biotin binding capacity of 7 times the estimated dietary biotin intake of a typical self-selected diet. In study design 2, participants (n = 2; 2 women) received double the amount of avidin capsules (14 times the estimated dietary biotin intake). In study design 3, participants (n = 5; 3 women) consumed egg-white beverages containing avidin with a biotin binding capacity of 7 times the estimated dietary biotin intake. Established indices of biotin status [lymphocyte propionyl-CoA carboxylase activity; urinary excretion of 3-hydroxyisovaleric acid, 3-hydroxyisovaleryl carnitine (3HIA-carnitine), and biotin; and plasma concentration of 3HIA-carnitine] indicated that study designs 1 and 2 were not effective in inducing marginal biotin deficiency, but study design 3 was as effective as previous inpatient study designs that induced deficiency by egg-white beverage. Marginal biotin deficiency can be induced experimentally by using a cost-effective outpatient design by avidin delivery in egg-white beverages. This design should be useful to the broader nutritional research community.

Conceptual design studies of 1985 commercial VTOL transports that utilized rotors, Volume 2

NASA Technical Reports Server (NTRS)

Magee, J. P.; Clark, R.; Alexander, H. R.

1974-01-01

Results of conceptual design studies of tilt rotor and tandem helicopter aircraft for a 200 nautical mile commercial short haul transport mission are presented. The trade study data used in selecting the design point aircraft and technology details necessary to support the design conclusions are included.

76 FR 338 - Notice of Proposed Information Collection Requests

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-04

... feasibility of a promising practices study of Upward Bound that uses a rigorous quasi-experimental design. The design and feasibility report will develop a set of design options for conducting a study of Upward Bound and examine their applicability to studies of other TRIO programs. If a rigorous evaluation design...

The Perception on Fundamentals of Online Courses: A Case on Prospective Instructional Designers

ERIC Educational Resources Information Center

Genç, Zülfü; Tinmaz, Hasan

2016-01-01

This study focuses on prospective instructional designers' perception toward creating online courses including which elements are essential for developing such platforms. The study is significant for revealing what the prospective instructional designers focus on while they design certain learning opportunities. The participants of the study were…

78 FR 66941 - Design Considerations for Pivotal Clinical Investigations for Medical Devices; Guidance for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-07

... assessment. In some cases, a PMA may include multiple studies designed to answer different scientific... designing clinical studies intended to support premarket submissions for medical devices and for FDA staff who review those submissions. This guidance document describes different study design principles...

Multidisciplinary design optimization using genetic algorithms

NASA Technical Reports Server (NTRS)

Unal, Resit

1994-01-01

Multidisciplinary design optimization (MDO) is an important step in the conceptual design and evaluation of launch vehicles since it can have a significant impact on performance and life cycle cost. The objective is to search the system design space to determine values of design variables that optimize the performance characteristic subject to system constraints. Gradient-based optimization routines have been used extensively for aerospace design optimization. However, one limitation of gradient based optimizers is their need for gradient information. Therefore, design problems which include discrete variables can not be studied. Such problems are common in launch vehicle design. For example, the number of engines and material choices must be integer values or assume only a few discrete values. In this study, genetic algorithms are investigated as an approach to MDO problems involving discrete variables and discontinuous domains. Optimization by genetic algorithms (GA) uses a search procedure which is fundamentally different from those gradient based methods. Genetic algorithms seek to find good solutions in an efficient and timely manner rather than finding the best solution. GA are designed to mimic evolutionary selection. A population of candidate designs is evaluated at each iteration, and each individual's probability of reproduction (existence in the next generation) depends on its fitness value (related to the value of the objective function). Progress toward the optimum is achieved by the crossover and mutation operations. GA is attractive since it uses only objective function values in the search process, so gradient calculations are avoided. Hence, GA are able to deal with discrete variables. Studies report success in the use of GA for aircraft design optimization studies, trajectory analysis, space structure design and control systems design. In these studies reliable convergence was achieved, but the number of function evaluations was large compared with efficient gradient methods. Applicaiton of GA is underway for a cost optimization study for a launch-vehicle fuel-tank and structural design of a wing. The strengths and limitations of GA for launch vehicle design optimization is studied.

WeSaySo Case Study: Designing and Implementing a Case Study for Use in an Instructional Design Class.

ERIC Educational Resources Information Center

Graves, Rick; Barnett, Mardee; Gamble, Yolanda; Kolak, Mike

A case study was used in an instructional design class to facilitate the transfer of conceptual knowledge to concrete concerns and to aid instructional technology graduate students' understanding of the steps involved in designing, analyzing, and implementing an effective needs analysis. The case study involved real events at fictitious company…

The application of mixed methods designs to trauma research.

PubMed

Creswell, John W; Zhang, Wanqing

2009-12-01

Despite the use of quantitative and qualitative data in trauma research and therapy, mixed methods studies in this field have not been analyzed to help researchers designing investigations. This discussion begins by reviewing four core characteristics of mixed methods research in the social and human sciences. Combining these characteristics, the authors focus on four select mixed methods designs that are applicable in trauma research. These designs are defined and their essential elements noted. Applying these designs to trauma research, a search was conducted to locate mixed methods trauma studies. From this search, one sample study was selected, and its characteristics of mixed methods procedures noted. Finally, drawing on other mixed methods designs available, several follow-up mixed methods studies were described for this sample study, enabling trauma researchers to view design options for applying mixed methods research in trauma investigations.

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 2: The design process

NASA Technical Reports Server (NTRS)

Gillette, W. B.; Turner, M. J.; Southall, J. W.; Whitener, P. C.; Kowalik, J. S.

1973-01-01

The extent to which IPAD is to support the design process is identified. Case studies of representative aerospace products were developed as models to characterize the design process and to provide design requirements for the IPAD computing system.

Design of a Blended Learning Environment: Considerations and Implementation Issues

ERIC Educational Resources Information Center

Gedik, Nuray; Kiraz, Ercan; Ozden, M. Yasar

2013-01-01

This study identified critical issues in the design of a blended learning environment by examining basic design considerations and implementation issues. Following a design-based research approach with the phenomenological tradition of qualitative research, the study investigated instructor experiences relating to the design, development, and…