Earth's magnetic field is probably not reversing.

PubMed

Brown, Maxwell; Korte, Monika; Holme, Richard; Wardinski, Ingo; Gunnarson, Sydney

2018-05-15

The geomagnetic field has been decaying at a rate of ∼5% per century from at least 1840, with indirect observations suggesting a decay since 1600 or even earlier. This has led to the assertion that the geomagnetic field may be undergoing a reversal or an excursion. We have derived a model of the geomagnetic field spanning 30-50 ka, constructed to study the behavior of the two most recent excursions: the Laschamp and Mono Lake, centered at 41 and 34 ka, respectively. Here, we show that neither excursion demonstrates field evolution similar to current changes in the geomagnetic field. At earlier times, centered at 49 and 46 ka, the field is comparable to today's field, with an intensity structure similar to today's South Atlantic Anomaly (SAA); however, neither of these SAA-like fields develop into an excursion or reversal. This suggests that the current weakened field will also recover without an extreme event such as an excursion or reversal. The SAA-like field structure at 46 ka appears to be coeval with published increases in geomagnetically modulated beryllium and chlorine nuclide production, despite the global dipole field not weakening significantly in our model during this time. This agreement suggests a greater complexity in the relationship between cosmogenic nuclide production and the geomagnetic field than is commonly assumed.

Load Dependency of Postural Control - Kinematic and Neuromuscular Changes in Response to over and under Load Conditions

PubMed Central

Ritzmann, Ramona; Freyler, Kathrin; Weltin, Elmar; Krause, Anne; Gollhofer, Albert

2015-01-01

Introduction Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL) and under loading (UL) used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms. Methods Balance performance was recorded under normal loading (NL, 1g), UL (0.16g; 0.38g) and OL (1.8g) in monopedal stance. Center of pressure (COP) displacement and frequency distribution (low 0.15-0.5Hz (LF), medium 0.5-2Hz (MF), high 2-6Hz (HF)) as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios). Results Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL. Conclusion Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal segments to adjust the center of gravity above the base of support. PMID:26053055

Laterally Translating Seal Carrier For A Drilling Mud Motor Sealed Bearing Assembly

DOEpatents

Dietle, Lannie

1993-03-23

A sealing and lubrication assembly for rotating shafts intended for operation in an abrasive environment and wherein the rotary shaft may have lateral translation or excursion during its rotation. A housing receives the rotary shaft in bearing supporting relation and defines a lubricant chamber about the shaft. A seal carrier is movably positioned about the rotary shaft and has non-rotatable articulating or laterally translating relation with the housing. A high pressure rotary shaft seal is supported by the seal carrier and maintains bearing and sealing engagement with the rotary shaft during its lateral translation or excursion. The seal carrier is hydraulic force balanced and thus is not subject to pressure induced loads that might otherwise interfere with its articulation or lateral translation.

On the suitability of fibre optical parametric amplifiers for use in all-optical agile photonic networks

NASA Astrophysics Data System (ADS)

Gryspolakis, Nikolaos

The objective of this thesis is to investigate the suitability of fibre optical parametric amplifiers (FOPAs) for use in multi-channel, dynamic networks. First, we investigate their quasi-static behaviour in such an environment. We study the behaviour of a FOPA under realistic conditions and we examine the impact on the gain spectrum of channel addition for several different operating conditions and regimes. In particular, we examine the impact of surviving channel(s) position, input power and channel spacing. We see how these parameters affect the gain tilt as well as its dynamic characteristics, namely the generation of under or over-shoots at the transition point, possible dependence of rise and fall times on any of the aforementioned parameters and how the gain excursions depend on those parameters. For these studies we assume continuous wave operation for all signals. We observe that the gain spectrum changes are a function of the position and the spacing of the channels. We also find that the gain excursion can reach several dBs (up to 5 dB) in the case of channel add/drop and are heavily dependent on the position of the surviving channels. The channels located in the middle of the transmission band are more prone to channel add/drop-induced gain changes. Moreover, we investigate for the first time the FOPA dynamic behaviour in a packet switching scenario. This part of the study assumes that all but one channels normally vary in a packet-switched fashion. The remaining channel (probe channel) is expected to undergo gain variations due to the perturbation of the system experienced by the other channels. Furthermore, we consider several different scenarios for which the channels spacing, per channel input power (PCIP), variance of the power fluctuation and position of the probe channel will change. We find that when the FOPA operates near saturation the target gain is not achieved more than 50% of the time while the peak-to-peak gain excursions can exceed 1 dB. Next, we introduce modulated channels to the amplifier in order to compare their effect on the Bit Error Rate (BER) performance. We consider the impact on FOPAs when employing different modulation formats, such as RZ, NRZ and RZ-DPSK. Carefully selected modulation formats can improve BER performance and reduce the effects of cross-phase modulation, four wave mixing (FWM) products generation or dispersion (non-linear and linear inter-channel interference). Especially for the case of FOPAs, because of the ultra-fast interaction times of the FWM phenomenon, cross gain modulation can be a great deterrent for using FOPAs. We use RZ-DPSK in order to suppress the WDM signal crosstalk. Only by using RZ-DPSK, we obtain an improved receiver sensitivity of 5 dB when operating at 40 Gb/s. Finally, we investigate ways to mitigate such effects as the ones described above (gain excursions, gain tilt, etc.). We demonstrate that by using a ring configuration with optical feedback for the first time in FOPAs, we can achieve all-optical gain clamping (AOGC), mitigating gain excursions and attaining gain, independent of channel input power for a large range of PCIP. For example, with the use of AOGC, we reduce the add/drop-induced gain excursions from 4 dB to 0.6 dB. Also, by the combined use of AOGC and RZ-DPSK, we mitigate most of the aforementioned hindrances described above.

Perception of a Sung Vowel as a Function of Frequency-Modulation Rate and Excursion in Listeners with Normal Hearing and Hearing Impairment

ERIC Educational Resources Information Center

Vatti, Marianna; Santurette, Sébastien; Pontoppidan, Niels Henrik; Dau, Torsten

2014-01-01

Purpose: Frequency fluctuations in human voices can usually be described as coherent frequency modulation (FM). As listeners with hearing impairment (HI listeners) are typically less sensitive to FM than listeners with normal hearing (NH listeners), this study investigated whether hearing loss affects the perception of a sung vowel based on FM…

Constellation Architecture Team-Lunar Scenario 12.0 Habitation Overview

NASA Technical Reports Server (NTRS)

Kennedy, Kriss J.; Toups, Larry D.; Rudisill, Marianne

2010-01-01

This paper will describe an overview of the Constellation Architecture Team Lunar Scenario 12.0 (LS-12) surface habitation approach and concept performed during the study definition. The Lunar Scenario 12 architecture study focused on two primary habitation approaches: a horizontally-oriented habitation module (LS-12.0) and a vertically-oriented habitation module (LS-12.1). This paper will provide an overview of the 12.0 lunar surface campaign, the associated outpost architecture, habitation functionality, concept description, system integration strategy, mass and power resource estimates. The Scenario 12 architecture resulted from combining three previous scenario attributes from Scenario 4 "Optimized Exploration", Scenario 5 "Fission Surface Power System" and Scenario 8 "Initial Extensive Mobility" into Scenario 12 along with an added emphasis on defining the excursion ConOps while the crew is away from the outpost location. This paper will describe an overview of the CxAT-Lunar Scenario 12.0 habitation concepts and their functionality. The Crew Operations area includes basic crew accommodations such as sleeping, eating, hygiene and stowage. The EVA Operations area includes additional EVA capability beyond the suitlock function such as suit maintenance, spares stowage, and suit stowage. The Logistics Operations area includes the enhanced accommodations for 180 days such as enhanced life support systems hardware, consumable stowage, spares stowage, interconnection to the other habitation elements, a common interface mechanism for future growth, and mating to a pressurized rover or Pressurized Logistics Module (PLM). The Mission & Science Operations area includes enhanced outpost autonomy such as an IVA glove box, life support, medical operations, and exercise equipment.

APOLLO/SATURN (A/S) 201 - LAUNCH - CAPE

NASA Image and Video Library

1966-02-26

A/S 201 was launched from the Kennedy Space Center Launch Complex 34 at 11:12 a.m., 02/26/1966. The instrumented Apollo Command and Service Module, and, a spacecraft Lunar Excursion Module Adapter, was successfully launched on the unmanned suborbital mission by the Saturn 1B to check spacecraft launch vehicle mechanical compatibility and to test the spacecraft heat shield in a high-velocity re-entry mode. CAPE KENNEDY, FL

Apollo 16 lunar module 'Orion' photographed from distance during EVA

NASA Technical Reports Server (NTRS)

1972-01-01

The Apollo 16 Lunar Module 'Orion' is photographed from a distance by Astronaut Chares M. Duke Jr., lunar module pilot, aboard the moving Lunar Roving Vehicle. Astronauts Duke and John W. Young, commander, were returning from the excursion to Stone Mountain during the second Apollo 16 extravehicular activity (EVA-2). The RCA color television camera mounted on the LRV is in the foreground. A portion of the LRV's high-gain antenna is at top left. Smoky Mountain rises behind the LM in this north-looking view at the Descartes landing site.

Perioperative optimal blood pressure as determined by ultrasound tagged near infrared spectroscopy and its association with postoperative acute kidney injury in cardiac surgery patients.

PubMed

Hori, Daijiro; Hogue, Charles; Adachi, Hideo; Max, Laura; Price, Joel; Sciortino, Christopher; Zehr, Kenton; Conte, John; Cameron, Duke; Mandal, Kaushik

2016-04-01

Perioperative blood pressure management by targeting individualized optimal blood pressure, determined by cerebral blood flow autoregulation monitoring, may ensure sufficient renal perfusion. The purpose of this study was to evaluate changes in the optimal blood pressure for individual patients, determined during cardiopulmonary bypass (CPB) and during early postoperative period in intensive care unit (ICU). A secondary aim was to examine if excursions below optimal blood pressure in the ICU are associated with risk of cardiac surgery-associated acute kidney injury (CSA-AKI). One hundred and ten patients undergoing cardiac surgery had cerebral blood flow monitored with a novel technology using ultrasound tagged near infrared spectroscopy (UT-NIRS) during CPB and in the first 3 h after surgery in the ICU. The correlation flow index (CFx) was calculated as a moving, linear correlation coefficient between cerebral flow index measured using UT-NIRS and mean arterial pressure (MAP). Optimal blood pressure was defined as the MAP with the lowest CFx. Changes in optimal blood pressure in the perioperative period were observed and the association of blood pressure excursions (magnitude and duration) below the optimal blood pressure [area under the curve (AUC) < OptMAP mmHgxh] with incidence of CSA-AKI (defined using Kidney Disease: Improving Global Outcomes criteria) was examined. Optimal blood pressure during early ICU stay and CPB was correlated (r = 0.46, P < 0.0001), but was significantly higher in the ICU compared with during CPB (75 ± 8.7 vs 71 ± 10.3 mmHg, P = 0.0002). Thirty patients (27.3%) developed CSA-AKI within 48 h after the surgery. AUC < OptMAP was associated with CSA-AKI during CPB [median, 13.27 mmHgxh, interquartile range (IQR), 4.63-20.14 vs median, 6.05 mmHgxh, IQR 3.03-12.40, P = 0.008], and in the ICU (13.72 mmHgxh, IQR 5.09-25.54 vs 5.65 mmHgxh, IQR 1.71-13.07, P = 0.022). Optimal blood pressure during CPB and in the ICU was correlated. Excursions below optimal blood pressure (AUC < OptMAP mmHgXh) during perioperative period are associated with CSA-AKI. Individualized blood pressure management based on cerebral autoregulation monitoring during the perioperative period may help improve CSA-AKI-related outcomes. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Perioperative optimal blood pressure as determined by ultrasound tagged near infrared spectroscopy and its association with postoperative acute kidney injury in cardiac surgery patients

PubMed Central

Hori, Daijiro; Hogue, Charles; Adachi, Hideo; Max, Laura; Price, Joel; Sciortino, Christopher; Zehr, Kenton; Conte, John; Cameron, Duke; Mandal, Kaushik

2016-01-01

OBJECTIVES Perioperative blood pressure management by targeting individualized optimal blood pressure, determined by cerebral blood flow autoregulation monitoring, may ensure sufficient renal perfusion. The purpose of this study was to evaluate changes in the optimal blood pressure for individual patients, determined during cardiopulmonary bypass (CPB) and during early postoperative period in intensive care unit (ICU). A secondary aim was to examine if excursions below optimal blood pressure in the ICU are associated with risk of cardiac surgery-associated acute kidney injury (CSA-AKI). METHODS One hundred and ten patients undergoing cardiac surgery had cerebral blood flow monitored with a novel technology using ultrasound tagged near infrared spectroscopy (UT-NIRS) during CPB and in the first 3 h after surgery in the ICU. The correlation flow index (CFx) was calculated as a moving, linear correlation coefficient between cerebral flow index measured using UT-NIRS and mean arterial pressure (MAP). Optimal blood pressure was defined as the MAP with the lowest CFx. Changes in optimal blood pressure in the perioperative period were observed and the association of blood pressure excursions (magnitude and duration) below the optimal blood pressure [area under the curve (AUC) < OptMAP mmHgxh] with incidence of CSA-AKI (defined using Kidney Disease: Improving Global Outcomes criteria) was examined. RESULTS Optimal blood pressure during early ICU stay and CPB was correlated (r = 0.46, P < 0.0001), but was significantly higher in the ICU compared with during CPB (75 ± 8.7 vs 71 ± 10.3 mmHg, P = 0.0002). Thirty patients (27.3%) developed CSA-AKI within 48 h after the surgery. AUC < OptMAP was associated with CSA-AKI during CPB [median, 13.27 mmHgxh, interquartile range (IQR), 4.63–20.14 vs median, 6.05 mmHgxh, IQR 3.03–12.40, P = 0.008], and in the ICU (13.72 mmHgxh, IQR 5.09–25.54 vs 5.65 mmHgxh, IQR 1.71–13.07, P = 0.022). CONCLUSIONS Optimal blood pressure during CPB and in the ICU was correlated. Excursions below optimal blood pressure (AUC < OptMAP mmHgXh) during perioperative period are associated with CSA-AKI. Individualized blood pressure management based on cerebral autoregulation monitoring during the perioperative period may help improve CSA-AKI-related outcomes. PMID:26763042

Lunar Excursion Model in Full Scale Wind Tunnel. Apollo Project. Bell Lunar Landing Training Vehicle (LLTV)

NASA Image and Video Library

1969-01-16

Concept model of the Lunar Excursion Module tested in the Full-Scale wind tunnel. -- Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, (Washington: NASA, 1995), p. 356.-L69-670 Bell Lunar Landing Training Vehicle (LLTV): Following the crash of a sister Lunar Landing Training Vehicle at Ellington Field in Houston, Texas, the LLTV NASA 952 was sent from Houston to Langley for tests in the 30 x 60 Full Scale Tunnel. The LLTV was returned to Houston for further training use a short time later. NASA 952 is now on exhibit at the Johnson Space Center in Houston, Texas.

Reliability and comparison of trunk and pelvis angles, arm distance and center of pressure in the seated functional reach test with and without foot support in children.

PubMed

Radtka, Sandra; Zayac, Jacqueline; Goldberg, Krystyna; Long, Michael; Ixanov, Rustem

2017-03-01

This study determined test-retest reliability of trunk and pelvis joint angles, arm distance and center of pressure (COP) excursion for the seated functional reach test (FRT) and compared these variables during the seated FRT with and without foot support. Fifteen typically developing children (age 9.3±4.1years) participated. Trunk and pelvis joint angles, arm distance, and COP excursion were collected on two days using three-dimensional motion analysis and a force plate while subjects reached maximally with and without foot support in the anterior, anterior/lateral, lateral, posterior/lateral directions. Age, weight, height, trunk and arm lengths were correlated (p<0.01) with maximum arm distance reached. Maximum arm distance, trunk and pelvis joint angles, and COP with and without foot support were not significant (p<0.05) for the two test periods. Excellent reliability (ICCs>0.75) was found for maximum arm distance reached in all four directions in the seated FRT with and without foot support. Most trunk and pelvis joint angles and COP excursions during maximum reach in all four directions showed excellent to fair reliability (ICCs>0.40-0.75). Reaching with foot support in all directions was significantly greater (p<0.05) than without foot support; however, most COP excursions and trunk and pelvic angles were not significantly different. Findings support the addition of anterior/lateral and posterior/lateral reaching directions in the seated FRT. Trunk and pelvis movement analysis is important to examine in the seated FRT to determine the specific movement strategies needed for maximum reaching without loss of balance. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of Data-Logging Transducer to Passively Collect Pressure Vessel p/T History

NASA Technical Reports Server (NTRS)

Wnuk, Stephen P.; Le, Son; Loew, Raymond A.

2013-01-01

Pressure vessels owned and operated by NASA are required to be regularly certified per agency policy. Certification requires an assessment of damage mechanisms and an estimation of vessel remaining life. Since detail service histories are not typically available for most pressure vessels, a conservative estimate of vessel pressure/temperature excursions is typically used in assessing fatigue life. This paper details trial use of a data-logging transducer to passively obtain actual pressure and temperature service histories of pressure vessels. The approach was found to have some potential for cost savings and other benefits in certain cases.

Concept of Operations for a Prospective "Proving Ground" in the Lunar Vicinity

NASA Technical Reports Server (NTRS)

Love, Stanley G.; Hill, James J.

2016-01-01

NASA is studying a "Proving Ground" near the Moon to conduct human space exploration missions in preparation for future flights to Mars. This paper describes a concept of operations ("conops") for activities in the Proving Ground, focusing on the construction and use of a mobile Cislunar Transit Habitat capable of months-long excursions within and beyond the Earth-Moon system. Key elements in the conops include the Orion spacecraft (with mission kits for docking and other specialized operations) and the Space Launch System heavy-lift rocket. Potential additions include commercial launch vehicles and logistics carriers, solar electric propulsion stages to move elements between different orbits and eventually take them on excursions to deep space, a node module with multiple docking ports, habitation and life support blocks, and international robotic and piloted lunar landers. The landers might include reusable ascent modules which could remain docked to in-space elements between lunar sorties. The architecture will include infrastructure for launch preparation, communication, mission control, and range safety. The conops describes "case studies" of notional missions chosen to guide the design of the architecture and its elements. One such mission is the delivery of a 10-ton pressurized element, co-manifested with an Orion on a Block 1B Space Launch System rocket, to the Proving Ground. With a large solar electric propulsion stage, the architecture could enable a year-long mission to land humans on a near-Earth asteroid. In the last case, after returning to near-lunar space, two of the asteroid explorers could join two crewmembers freshly arrived from Earth for a Moon landing, helping to safely quantify the risk of landing deconditioned crews on Mars. The conops also discusses aborts and contingency operations. Early return to Earth may be difficult, especially during later Proving Ground missions. While adding risk, limited-abort conditions provide needed practice for Mars, from which early return is likely to be impossible.

Dynamic Balance Deficits 6 Months Following First-Time Acute Lateral Ankle Sprain: A Laboratory Analysis.

PubMed

Doherty, Cailbhe; Bleakley, Chris; Hertel, Jay; Caulfield, Brian; Ryan, John; Delahunt, Eamonn

2015-08-01

Controlled laboratory study. To utilize kinematic and stabilometric measures to compare dynamic balance during performance of the Star Excursion Balance Test between persons 6 months following first-time lateral ankle sprain (LAS) and a noninjured control group. Biomechanical evaluation of dynamic balance in persons following first-time LAS during performance of the Star Excursion Balance Test could provide insight into the mechanisms by which individuals proceed to recover fully or develop chronic ankle instability. Sagittal plane kinematics of the lower extremity and the center-of-pressure path during the performance of the anterior, posterolateral, and posteromedial reach directions of the Star Excursion Balance Test were obtained from 69 participants 6 months following first-time acute LAS and from a control group of 20 noninjured participants. Compared to the control group, the LAS group displayed lower normalized reach distances in all 3 reach directions on the injured and noninjured limbs, with the largest observed effect size in the posterolateral direction (P = .001, ηp(2) = 0.07). The performance impairment was associated with less hip and knee flexion and ankle dorsiflexion at the point of maximum reach (P<.02), and coincided with less complexity of the center-of-pressure path (P<.05). Participants with a 6-month history of LAS exhibit a persistence of deficits previously established in the acute phase of injury.

Disk Disruptions and X-ray Intensity Excursions in Cyg X-2, LMC X-3 and Cyg X-3

NASA Astrophysics Data System (ADS)

Boyd, P. T.; Smale, A. P.

2001-05-01

The RXTE All Sky Monitor soft X-ray light curves of many X-ray binaries show long-term intensity variations (a.k.a "superorbital periodicities") that have been ascribed to precession of a warped, tilted accretion disk around the X-ray source. We have found that the excursion times between X-ray minima in Cyg X-2 can be characterized as a series of integer multiples of the 9.8 binary orbital period, (as opposed to the previously reported stable 77.7 day single periodicity, or a single modulation whose period changes slowly with time). While the data set is too short for a proper statistical analysis, it is clear that the length of any given intensity excursion cannot be used to predict the next (integer) excursion length in the series. In the black hole candidate system LMC X-3, the excursion times are shown to be related to each other by rational fractions. We find that the long term light curve of the unusual galactic X-ray jet source Cyg X-3 can also be described as a series of intensity excursions related to each other by integer multiples of a fundamental underlying clock. In the latter cases, the clock is apparently not related to the known binary periods. A unified physical model, involving both an inclined accretion disk and a fixed-probability disk disruption mechanism is presented, and compared with three-body scattering results. Each time the disk passes through the orbital plane it experiences a fixed probability P that it will disrupt. This model has testable predictions---the distribution of integers should resemble that of an atomic process with a characteristic half life. Further analysis can support or refute the model, and shed light on what system parameters effectively set the value of P.

A Modular Instrumentation System for NASA's Habitat Demonstration Unit

NASA Technical Reports Server (NTRS)

Rojdev, Kristina; Kennedy, Kriss; Yim, Hester; Wagner, Raymond S.; Hong, Todd; Studor, George; Delaune, Paul

2010-01-01

NASA's human spaceflight program is focused on developing technologies to expand the reaches of human exploration and science activities beyond low earth orbit. A critical aspect of living in space or on planetary surfaces is habitation, which provides a safe and comfortable space in which humans can live and work. NASA is seeking out the best option for habitation by exploring several different concepts through the Habitat Demonstration Unit (HDU) project. The purpose of this HDU is to develop a fully autonomous habitation system that enables human exploration of space. One critical feature of the HDU project that helps to accomplish its mission of autonomy is the instrumentation system that monitors key subsystems operating within a Habitat configuration. The following paper will discuss previous instrumentation systems used in analog habitat concepts and how the current instrumentation system being implemented on the HDU1-PEM, or pressurized excursion module, is building upon the lessons learned of those previous systems. Additionally, this paper will discuss the benefits and the limitations of implementing a wireless sensor network (WSN) as the basis for data transport in the instrumentation system. Finally, this paper will address the experiences and lessons learned with integration, testing prior to deployment, and field testing at the JSC rock yard. NASA is developing the HDU1-PEM as a step towards a fully autonomous habitation system that enables human exploration of space. To accomplish this purpose, the HDU project is focusing on development, integration, testing, and evaluation of habitation systems. The HDU will be used as a technology pull, testbed, and integration environment in which to advance NASA's understanding of alternative mission architectures, requirements, and operations concepts definition and validation. This project is a multi-year effort. In 2010, the HDU1-PEM will be in a pressurized excursion module configuration, and in 2011 the module will be reconfigured for a pressurized core module configuration. Each year the HDU configurations will undergo testing at NASA's Desert Research and Technology Studies (D-RaTS) in Arizona [1]. As part of this project, a modular instrumentation system is developed to meet the monitoring needs of the HDU subsystems and to integrate with the current command and data handling infrastructure that has been developed for the project. The main objective of this study is to provide for the monitoring needs of the HDU. The requirements necessary to meet this objective are developed by working with the subsystem managers of the HDU to understand their monitoring needs. Additionally, the instrumentation system design leverages knowledge and lessons learned from previous studies, such as the inflatable habitat health monitoring system that was deployed in Antarctica [2], the integrated health monitoring system developed for NASA's Microhab [3], and the JSC Lunar Habitat Wireless Testbed to demonstrate a "standardsbased" approach to a wireless instrumentation system [4]. The HDU also requires flexibility in reconfiguration options, and it is necessary to demonstrate and evaluate a modular approach to an instrumentation system. Thus, the instrumentation system is designed in two parts: the primary system employs a standard WSN configuration, and the secondary system employs a wired USB hub. The WSN design provides for reconfiguration or replacement of sensors due to malfunctions or upgrades by using a wireless node that accepts ten instrument inputs and wirelessly transmits the data to the command and data handling system. The USB hub is necessary for those instruments that operate using a wired USB connection, although the design attempts to limit the amount of sensors that need to be wired connections.

Growth of Three Lettuce Cultivars in NASA's HDU PEM During the 2010 DRATS Test

NASA Technical Reports Server (NTRS)

Stutte, Gary W.; Newsham, Gerard; Wheeler, Raymond

2011-01-01

NASA's 2010 Desert Research and Technology Studies (DRATS) of the VEGGIE Food Production System in the Habitat Demonstration Unit (HDU) Pressurized Excursion Module (PEM) was the first operational evaluation of salad crop production technology in a NASA analog test. Rooting media and slow release fertilizers were evaluated for three lettuce cultivars that had shown promise as candidates for a surface based food production system. These tests involved comparing growth, color and quality of the lettuce cultivars grown under VEGGIE LED array (Orbitec, Madison, WI) or Biomass Production System for Education ((BSEe), Orbitec, Madison, WI) compact fluorescent lamps using a gravity feed water delivery system. Mission relevant conditions of CO2, temperature and RH were maintained using controlled environment chambers (EGC, Chagrin Falls, OH). Growth data was obtained for the two red leaf lettuce cultivars, Outredgeous and Firecracker, and the green Bibb lettuce cultivar, Flandria. Growth and quality was evaluated using different concentrations (7.5 g/L and 15 g/L) of commercial slow release fertilizer (Osmocote Plus 15-9-12, Scotts, Maryville, OH) and Nutricote 18-6-8 (Florikan, Sarasota, FL) in either a peat/vermiculite media (sunshine LP5 MiX, Sungro, Bellview, WA) or calcined montmorillonite clay [(arcillite,)Turface Proleague, Profile LLC, Buffalo Grove, IL]. The commercial peat/vermiculite mix generally resulted in larger plants than those grown in arcillite. Increasing the concentration of Osmocote from 7.5 to 15 g/L increased the height, dry mass, and leaf area of lettuce cultivars. In contrast, there was a decrease in growth parameters when concentration of Nutricote was increased from 7.5 to 15 g/L. The best growth was obtained with the 7.5 g/L Nutricote using a commercial peat/vermiculite mixture. This media was used for field testing VEGGIE plant system in the 2010 DRAT test. The VEGGIE nutrient delivery system worked well, was able to be maintained by multiple operators with a minimum of training, and supported excellent lettuce growth for the duration of the 14-day test. The operational DRAT field testing in the HDU identified light quality issues related to morphology and pigment development that will need to be addressed through additional testing. Feedback from the crew, ground support personnel, and human factors leads was uniformly positive on the psychological value of having the crop production system in the pressurized excursion module. Data are being used to design a plant atrium with LED lighting to evaluate salad crop growth during NASA's 2011 DRATS test.

Interferometer for the measurement of plasma density

DOEpatents

Jacobson, Abram R.

1980-01-01

An interferometer which combines the advantages of a coupled cavity interferometer requiring alignment of only one light beam, and a quadrature interferometer which has the ability to track multi-fringe phase excursions unambiguously. The device utilizes a Bragg cell for generating a signal which is electronically analyzed to unambiguously determine phase modulation which is proportional to the path integral of the plasma density.

Apollo 16 lunar module "Orion" photographed from distance during EVA

NASA Image and Video Library

1972-04-22

AS16-115-18549 (22 April 1972) --- The Apollo 16 Lunar Module (LM) "Orion" is photographed from a distance by astronaut Charles M. Duke Jr., lunar module pilot, aboard the moving Lunar Roving Vehicle (LRV). Astronauts Duke and John W. Young, commander, were returning from their excursion to Stone Mountain during the second Apollo 16 extravehicular activity (EVA). The RCA color television camera mounted on the LRV is in the foreground. A portion of the LRV's high-gain antenna is at top left. Smoky Mountain rises behind the LM in this north-looking view at the Descartes landing site. While astronauts Young and Duke descended in the "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.

Three-Dimensional Right Ventricular Strain Versus Volume Quantification in Heart Transplant Recipients in Relation to Pulmonary Artery Pressure.

PubMed

Sade, Leyla Elif; Kozan, Hatice; Eroglu, Serpil; Pirat, Bahar; Aydinalp, Alp; Sezgin, Atilla; Muderrisoglu, Haldun

2017-02-01

Residual pulmonary hypertension challenges the right ventricular function and worsens the prognosis in heart transplant recipients. The complex geometry of the right ventricle complicates estimation of its function with conventional transthoracic echocardiography. We evaluated right ventricular function in heart transplant recipients with the use of 3-dimensional echocardiography in relation to systolic pulmonary artery pressure. We performed 32 studies in 26 heart transplant patients, with 6 patients having 2 studies at different time points with different pressures and thus included. Right atrial volume, tricuspid annular plane systolic excursion, peak systolic annular velocity, fractional area change, and 2-dimensional speckle tracking longitudinal strain were obtained by 2-dimensional and tissue Doppler imaging. Three-dimensional right ventricular volumes, ejection fraction, and 3-dimensional right ventricular strain were obtained from the 3-dimensional data set by echocardiographers. Systolic pulmonary artery pressure was obtained during right heart catheterization. Overall mean systolic pulmonary artery pressure was 26 ± 7 mm Hg (range, 14-44 mmHg). Three-dimensional end-diastolic (r = 0.75; P < .001) and end-systolic volumes (r = 0.55; P = .001)correlated well with systolic pulmonary artery pressure. Right ventricular ejection fraction and right atrium volume also significantly correlated with systolic pulmonary artery pressure (r = 0.49 and P = .01 for both). However, right ventricular 2- and 3-dimensional strain, tricuspid annular plane systolic excursion, and tricuspid annular velocity did not. The effects of pulmonary hemodynamic burden on right ventricular function are better estimated by a 3-dimensional volume evaluation than with 3-dimensional longitudinal strain and other 2-dimensional and tissue Doppler measurements. These results suggest that the peculiar anatomy of the right ventricle necessitates 3-dimensional volume quantification in heart transplant recipients in relation to residual pulmonary hypertension.

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

Hobbs, Michael L.; Kaneshige, Michael J.; Erikson, William W.

Here, we have used a modified version of the Sandia Instrumented Thermal Ignition (SITI) experiment to develop a pressure-dependent, five-step ignition model for a plastic bonded explosive (PBX 9501) consisting of 95 wt% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazoncine (HMX), 2.5 wt% Estane® 5703 (a polyurethane thermoplastic), and 2.5 wt% of a nitroplasticizer (NP): BDNPA/F, a 50/50 wt% eutectic mixture bis(2,2-dinitropropyl)-acetal (BDNPA) and bis(2,2-dinitropropyl)-formal (BDNPF). The five steps include desorption of water, decomposition of the NP to form NO2, reaction of the NO2 with Estane® and HMX, and decomposition of HMX. The model was fit using our experiments and successfully validated with experiments from fivemore » other laboratories with scales ranging from about 2 g to more than 2.5 kg of PBX. Our experimental variables included density, confinement, free gas volume, and temperature. We measured internal temperatures, confinement pressure, and ignition time. In some of our experiments, we used a borescope to visually observe the decomposing PBX. Our observations included the endothermic β–δ phase change of the HMX, a small exothermic temperature excursion in low-density unconfined experiments, and runaway ignition. We hypothesize that the temperature excursion in these low density experiments was associated with the NP decomposing exothermically within the PBX sample. This reactant-limited temperature excursion was not observed with our thermocouples in the high-density experiments. For these experiments, we believe the binder diffused to the edges of our high density samples and decomposed next to the highly conductive wall as confirmed by our borescope images.« less

An activity index for geomagnetic paleosecular variation, excursions, and reversals

NASA Astrophysics Data System (ADS)

Panovska, S.; Constable, C. G.

2017-04-01

Magnetic indices provide quantitative measures of space weather phenomena that are widely used by researchers in geomagnetism. We introduce an index focused on the internally generated field that can be used to evaluate long term variations or climatology of modern and paleomagnetic secular variation, including geomagnetic excursions, polarity reversals, and changes in reversal rate. The paleosecular variation index, Pi, represents instantaneous or average deviation from a geocentric axial dipole field using normalized ratios of virtual geomagnetic pole colatitude and virtual dipole moment. The activity level of the index, σPi, provides a measure of field stability through the temporal standard deviation of Pi. Pi can be calculated on a global grid from geomagnetic field models to reveal large scale geographic variations in field structure. It can be determined for individual time series, or averaged at local, regional, and global scales to detect long term changes in geomagnetic activity, identify excursions, and transitional field behavior. For recent field models, Pi ranges from less than 0.05 to 0.30. Conventional definitions for geomagnetic excursions are characterized by Pi exceeding 0.5. Strong field intensities are associated with low Pi unless they are accompanied by large deviations from axial dipole field directions. σPi provides a measure of geomagnetic stability that is modulated by the level of PSV or frequency of excursional activity and reversal rate. We demonstrate uses of Pi for paleomagnetic observations and field models and show how it could be used to assess whether numerical simulations of the geodynamo exhibit Earth-like properties.

Mars EVA Suit Airlock (MESA)

NASA Astrophysics Data System (ADS)

Ransom, Stephen; Böttcher, Jörg; Steinsiek, Frank

The Astrium Space Infrastructure Division has begun an in-house research activity of an Earth-based simulation facility supporting future manned missions to Mars. This research unit will help to prepare and support planned missions in the following ways: 1) to enable the investigation and analysis of contamination issues in advance of a human visit to Mars; 2) as a design tool to investigate and simulate crew operations; 3) to simulate crew operation during an actual mission; 4) to enable on-surface scientific operations without leaving the shirt-sleeve habitation environment ("glove box principle"). The MESA module is a surface EVA facility attached to the main habitation or laboratory module, or mobile pressurized rover. It will be sealed, but not pressurized, and provide protection against the harsh Martian environment. This module will include a second crew airlock for safety reasons. The compartment can also be used to provide an external working bench and experiment area for the crew. A simpler MESA concept provides only an open shelter against wind and dust. This concept does not incorporate working and experimental areas. The principle idea behind the MESA concept is to tackle the issue of contamination by minimizing the decontamination processes needed to clean surface equipment and crew suit surfaces after an EVA excursion prior to the astronaut re-entering the habitable area. The technical solution envisages the use of a dedicated crew suit airlock. This airlock uses an EVA suit which is externally attached by its back-pack to the EVA compartment area facing the Martian environment. The crew donns the suit from inside the habitable volume through the airlock on the back of the suit. The surface EVA can be accomplished after closing the back-pack and detaching the suit. A special technical design concept foresees an extendable suit back-pack, so that the astronaut can operate outside and in the vincinity of the module. The key driver in the investigation is the problem of contamination of the habitable volume by EVA and sampling activities and the transport of Earth-generated contaminants to Mars.

Right ventricular function in heart failure with preserved ejection fraction: a community-based study.

PubMed

Mohammed, Selma F; Hussain, Imad; AbouEzzeddine, Omar F; Abou Ezzeddine, Omar F; Takahama, Hiroyuki; Kwon, Susan H; Forfia, Paul; Roger, Véronique L; Redfield, Margaret M

2014-12-23

The prevalence and clinical significance of right ventricular (RV) systolic dysfunction (RVD) in patients with heart failure and preserved ejection fraction (HFpEF) are not well characterized. Consecutive, prospectively identified HFpEF (Framingham HF criteria, ejection fraction ≥50%) patients (n=562) from Olmsted County, Minnesota, underwent echocardiography at HF diagnosis and follow-up for cause-specific mortality and HF hospitalization. RV function was categorized by tertiles of tricuspid annular plane systolic excursion and by semiquantitative (normal, mild RVD, or moderate to severe RVD) 2-dimensional assessment. Whether RVD was defined by semiquantitative assessment or tricuspid annular plane systolic excursion ≤15 mm, HFpEF patients with RVD were more likely to have atrial fibrillation, pacemakers, and chronic diuretic therapy. At echocardiography, patients with RVD had slightly lower left ventricular ejection fraction, worse diastolic dysfunction, lower blood pressure and cardiac output, higher pulmonary artery systolic pressure, and more severe RV enlargement and tricuspid valve regurgitation. After adjustment for age, sex, pulmonary artery systolic pressure, and comorbidities, the presence of any RVD by semiquantitative assessment was associated with higher all-cause (hazard ratio=1.35; 95% confidence interval, 1.03-1.77; P=0.03) and cardiovascular (hazard ratio=1.85; 95% confidence interval, 1.20-2.80; P=0.006) mortality and higher first (hazard ratio=1.99; 95% confidence interval, 1.35-2.90; P=0.0006) and multiple (hazard ratio=1.81; 95% confidence interval, 1.18-2.78; P=0.007) HF hospitalization rates. RVD defined by tricuspid annular plane systolic excursion values showed similar but weaker associations with mortality and HF hospitalizations. In the community, RVD is common in HFpEF patients, is associated with clinical and echocardiographic evidence of more advanced HF, and is predictive of poorer outcomes. © 2014 American Heart Association, Inc.

Neil Armstrong at Lunar Landing Research Facility

NASA Image and Video Library

1969-02-12

Neil Armstrong with the Lunar Excursion Module (LEM). Caption: "Not long after this photo was taken in front of the Lunar Landing Research Facility, astronaut Neil Armstrong became the first human to step upon the surface of the Moon." Photograph published in Winds of Change, 75th Anniversary NASA publication, by James Schultz, page 91. Also published in " A Century at Langley" by Joseph Chambers, pg. 95

Comment [on 'Are Proterozoic cap carbonates and isotopic excursions a record of gas hydrate destabilization following Earth’s coldest intervals?, Kennedy et al., Geology 29(5), 442-446

USGS Publications Warehouse

Max, M.D.; Dillon, William P.

2002-01-01

We welcome the evidence noted by Kennedy et al. (2001) for strong methane excursions associated with the cessation of glacial episodes. They identify the carbon in cap carbonates overlying glacial sediments as probably being of biogenic origin and as likely having had a biogenic methane source. These authors suggest that the methane was released from gas hydrate, which we agree is likely. However, we suggest a different mechanism for that release, rather than their suggested warming event. We propose that a dominantly pressure-related mechanism would be more plausible for releasing sufficient methane from the huge gas hydrate reservoir to modify the global greenhouse and drive global warming in a geological instant.

Geomagnetic excursions in the Brunhes and Matuyama Chrons: Do they come in bunches?

NASA Astrophysics Data System (ADS)

Channell, J. E. T.

2012-04-01

Geomagnetic excursions, defined here as brief directional aberrations of the main dipole field outside the range of expected secular variation, remain controversial. Poorly-correlated records of apparent excursions from lavas and sediments can often be assigned to sampling artifacts, sedimentological phenomena, volcanic terrane effects, or local secular variation, rather than behavior of the main dipole field. Although records of magnetic excursions date from the 1960s, the number of Brunhes excursions in recent reviews of the subject have reached the 12-17 range, of which only about ~7 are adequately and/or consistently recorded. For the Matuyama Chron, the current inventory of excursions stands at about 10. The better quality excursion records, with reasonable age control, imply millennial-scale or even sub-millennial-scale durations. When "adequately" recorded, excursions are manifest as paired polarity reversals flanking virtual geomagnetic poles (VGPs) that reach high latitudes in the opposite hemisphere. At the young end of the excursion record, the Mono Lake (~33 ka) and Laschamp (~41 ka) excursions are well documented, although records of the former are not widely distributed. Several excursions younger than the Mono Lake excursion (at 17 ka and 25 ka) have recently been recorded in lavas and sediments, respectively. Is the 17-41 ka interval characterized by multiple excursions? Similarly, multiple excursions have been recorded in the 188-238 ka interval that encompasses records of the Iceland Basin excursion (~188 ka) and the Pringle Falls (PF) excursion. The PF excursion has been assigned ages in the 211-238 ka range. Does this mean that this interval is also characterized by several discrete excursions? The 500-600 ka interval incorporates not only the Big Lost excursion at ~565 ka, but also anomalous magnetization directions from lava flows, particularly in the West Eifel volcanics that yield mid-latitude northern-hemisphere VGPs with a range of Ar/Ar ages. The key question is whether such intervals of mid-latitude VGPs denote high-amplitude secular variation or inadequately recorded magnetic excursions. We propose that excursions characterized by high VGP latitudes in the opposite hemisphere should be termed Category 1 excursions, and those manifest by low/mid-latitude VGPs should be termed Category 2 excursions. In the future, improved records may "elevate" Category 2 excursions to Category 1. We do not view this subdivision of Category 1 and Category 2 excursions as necessarily a geomagnetic distinction, but possibly a distinction based on recording fidelity.

Variations in mid-ocean ridge magmatism and carbon emissions driven by glacial cycles

NASA Astrophysics Data System (ADS)

Katz, R. F.; Burley, J. M.; Huybers, P. J.; Langmuir, C. H.; Crowley, J. W.; Park, S. H.; Carbotte, S. M.; Ferguson, D.; Proistosescu, C.; Boulahanis, B.

2015-12-01

Glacial cycles transfer ˜5×10^19 kg of water between the oceans and ice sheets, causing pressure changes in the upper mantle with consequences for the melting of Earth's interior. Forced with Plio-Pleistocene sea-level variations, theoretical models of mid-ocean ridge magma/mantle dynamics predict temporal variations up to 10% in melt supply to the base of the crust. Moreover, a transport model for a perfectly incompatible element suggests that CO2 emissions from mid-ocean ridges could vary by a similar proportion, though with a longer time-lag.Bathymetry from the Australian-Antarctic ridge shows statistically significant spectral energy near the Milankovitch periods of 23, 41, and 100 thousand years, which is consistent with model predictions. These results suggest that abyssal hills record the magmatic response to changes in sea level. The mechanism by which variations in the rate of melt supply are expressed in the bathymetry is not understood.The same pressure variations that modulate the melting rate could also modulate the depth of the onset of silicate melting. As ice sheets grow and sea level drops, this onset deepens, causing melting at the base of the silicate melting regime. Excess highly incompatible elements like CO2 enter the melt and begin their journey to the ridge axis. Tens of thousands of years later, this additional CO2 flux is emitted into the climate system. Because of its delay with respect to sea-level change, the predicted variation in CO2 emissions could represent a restoring force on climate (and sea-level) excursions. This mechanism has a response time determined by the time scale of melt transport; it potentially introduces a resonant frequency into the climate system.

Quaternary magnetic excursions recorded in marine sediments.

NASA Astrophysics Data System (ADS)

Channell, J. E. T.

2017-12-01

This year is the golden (50th) anniversary of the first documentation of a magnetic excursion, the Laschamp excursion in volcanics from the Chaine des Puys (Bonhommet and Babkine, 1967). The first recording of an excursion in sediments was from the Blake Outer Ridge (Smith and Foster, 1969). Magnetic excursions are directional aberrations of the geomagnetic field apparently involving short-lived reversal of the main dipole field. They have durations of a few kyrs, and are therefore rarely recorded in sediments with mean sedimentation rates <10 cm/kyr. Certain Brunhes-aged excursions are now well documented having been recorded in both marine sediments and in lavas (Laschamp excursion, 41 ka). Other excursions have not been adequately recorded in lavas, but have been widely recorded in marine and lake sediments (Iceland Basin excursion, 190 ka). The recording of excursions is fortuitous both in lava sequences and in marine sediments due to their millennial/centennial-scale duration, however, the global recording of the Laschamp and Iceland Basin excursions imply that excursions involve the main dipole field, are recorded synchronously over the globe, and are therefore important in stratigraphic correlation. The marine sediment record includes magnetic excursions at 26 ka (Rockall), 32 ka (Mono Lake), 41 ka (Laschamp), 115 ka (Blake), 190 ka (Iceland Basin), 238 ka (Pringle Falls?), 286 ka (Portuguese Orphan), 495 ka (Bermuda), 540 ka (Big Lost), 590 ka (La Palma), and 670 ka (Osaka Bay), implying at least 11 excursions in the Brunhes Chron. For the Matuyama Chron, excursions have been recorded in marine sediments at 868 ka (Kamikatsura?), 932 ka (Santa Rosa), 1051 ka (Intra-Jaramillo), 1115 ka (Punaruu), 1255 ka (Bjorn), 1476 ka (Gardar), 1580 ka (Gilsa), and 2737 ka (Porcupine). Excursions coincide with minima in relative paleointensity (RPI) records. Ages are from correlation of excursion records to oxygen isotope records in the same cores, and ice-volume calibration of the oxygen isotope template. The marine sediment record of excursions, combined with independent documentation of excursions in lavas with Ar/Ar age control, is progressively strengthening our knowledge of the excursion inventory in the Quaternary, and enhancing the importance of excursions and RPI in Quaternary stratigraphy.

Cinerama sickness and postural instability.

PubMed

Bos, Jelte E; Ledegang, Wietse D; Lubeck, Astrid J A; Stins, John F

2013-01-01

Motion sickness symptoms and increased postural instability induced by motion pictures have been reported in a laboratory, but not in a real cinema. We, therefore, carried out an observational study recording sickness severity and postural instability in 19 subjects before, immediately and 45 min after watching a 1 h 3D aviation documentary in a cinema. Sickness was significantly larger right after the movie than before, and in a lesser extent still so after 45 min. The average standard deviation of the lateral centre of pressure excursions was significantly larger only right afterwards. When low-pass filtered at 0.1 Hz, lateral and for-aft excursions were both significantly larger right after the movie, while for-aft excursions then remained larger even after 45 min. Speculating on previous findings, we predict more sickness and postural instability in 3D than in 2D movies, also suggesting a possible, but yet unknown risk for work-related activities and vehicle operation. Watching motion pictures may be sickening and posturally destabilising, but effects in a cinema are unknown. We, therefore, carried out an observational study showing that sickness then is mainly an issue during the exposure while postural instability is an issue afterwards.

Downflow dryout in a heated ribbed vertical annulus with a cosine power profile (Results from test series ECS-2, WSR, and ECS-2cE)

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

Larson, T.K.; Anderson, J.L.; Condie, K.G.

Experiments designed to investigate surface dryout in a heated, ribbed annulus test section simulating one of the annular coolant channels of a Savannah River Plant production reactor Mark 22 fuel assembly have been conducted at the Idaho National Engineering Laboratory. The inner surface of the annulus was constructed of aluminum and was electrically heated to provide an axial cosine power profile and a flat azimuthal power shape. Data presented in this report are from the ECS-2, WSR, and ECS-2cE series of tests. These experiments were conducted to examine the onset of wall thermal excursion for a range of flow, inletmore » fluid temperature, and annulus outlet pressure. Hydraulic boundary conditions on the test section represent flowrates (0.1--1.4 1/s), inlet fluid temperatures (293--345 K), and outlet pressures (-18--139.7 cm of water relative to the bottom of the heated length (61--200 cm of water relative to the bottom of the lower plenum)) expected to occur during the Emergency Coolant System (ECS) phase of postulated Loss-of-Coolant Accident in a production reactor. The onset of thermal excursion based on the present data is consistent with data gathered in test rigs with flat axial power profiles. The data indicate that wall dryout is primarily a function of liquid superficial velocity. Air entrainment rate was observed to be a strong function of the boundary conditions (primarily flowrate and liquid temperature), but had a minor effect on the power at the onset of thermal excursion for the range of conditions examined. 14 refs., 33 figs., 13 tabs.« less

Modeling the measured effect of a nitroplasticizer (BDNPA/F) on cookoff of a plastic bonded explosive (PBX 9501)

DOE PAGES

Hobbs, Michael L.; Kaneshige, Michael J.; Erikson, William W.

2016-09-12

Here, we have used a modified version of the Sandia Instrumented Thermal Ignition (SITI) experiment to develop a pressure-dependent, five-step ignition model for a plastic bonded explosive (PBX 9501) consisting of 95 wt% octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazoncine (HMX), 2.5 wt% Estane® 5703 (a polyurethane thermoplastic), and 2.5 wt% of a nitroplasticizer (NP): BDNPA/F, a 50/50 wt% eutectic mixture bis(2,2-dinitropropyl)-acetal (BDNPA) and bis(2,2-dinitropropyl)-formal (BDNPF). The five steps include desorption of water, decomposition of the NP to form NO2, reaction of the NO2 with Estane® and HMX, and decomposition of HMX. The model was fit using our experiments and successfully validated with experiments from fivemore » other laboratories with scales ranging from about 2 g to more than 2.5 kg of PBX. Our experimental variables included density, confinement, free gas volume, and temperature. We measured internal temperatures, confinement pressure, and ignition time. In some of our experiments, we used a borescope to visually observe the decomposing PBX. Our observations included the endothermic β–δ phase change of the HMX, a small exothermic temperature excursion in low-density unconfined experiments, and runaway ignition. We hypothesize that the temperature excursion in these low density experiments was associated with the NP decomposing exothermically within the PBX sample. This reactant-limited temperature excursion was not observed with our thermocouples in the high-density experiments. For these experiments, we believe the binder diffused to the edges of our high density samples and decomposed next to the highly conductive wall as confirmed by our borescope images.« less

Activity of Shoulder Stabilizers and Prime Movers During an Unstable Overhead Press.

PubMed

Williams, Martin R; Hendricks, Dustin S; Dannen, Michael J; Arnold, Andrea M; Lawrence, Michael A

2018-06-08

Williams, MR Jr, Hendricks, DS, Dannen, MJ, Arnold, AM, and Lawrence, MA. Activity of shoulder stabilizers and prime movers during an unstable overhead press. J Strength Cond Res XX(X): 000-000, 2018-Overhead reaching is a common movement that relies heavily on muscles for dynamic stability. Stabilizer muscle activation increased during squatting and bench pressing with an unstable load, but the overhead press (OHP) has yet to be examined. The purpose of this study is to compare muscle activity of the shoulder stabilizers and prime movers and excursions of the center of pressure (CoP) during the OHP in 2 unstable and one stable conditions. Twelve men (aged 25.3 ± 2.7 years, mass: 91.5 ± 8.4 kg, height: 1.81 ± 0.06 m) pressed 50% of their 1 repetition maximum for 10 repetitions over 3 conditions: a straight stable barbell (SS), a straight unstable (SU) barbell with kettlebells suspend by elastic bands, and an unstable Earthquake (EU) bar with kettlebells suspended by elastic bands. Activity of the shoulder stabilizers and prime movers were measured via surface and indwelling electromyography. Center of pressure excursion of the right foot was also measured. A multivariate analysis was used to determine significant differences between conditions. Pressing with the EQ increased activation of the biceps brachii, erector spinae, latissimus dorsi, pectoralis major, rectus abdominus, rhomboids, and serratus anterior over the SS condition, whereas only the SU condition increased activation in the erector spinae and latissimus dorsi muscles. The EQ condition produced greater CoP excursion (35.3 ± 7.9% foot length) compared with the SU (28.0 ± 7.2% foot length) and SS (22.2 ± 6.3% foot length) conditions. Therefore, the EU condition may be an effective exercise to activate scapular stabilizers.

High-resolution record of the Laschamp geomagnetic excursion at the Blake-Bahama Outer Ridge

NASA Astrophysics Data System (ADS)

Bourne, Mark D.; Mac Niocaill, Conall; Thomas, Alex L.; Henderson, Gideon M.

2013-12-01

Geomagnetic excursions are brief deviations of the geomagnetic field from behaviour expected during `normal secular' variation. The Laschamp excursion at ˜41 ka was one such deviation. Previously published records suggest rapid changes in field direction and a concurrent substantial decrease in field intensity associated with this excursion. Accurate dating of excursions, and determination of their durations from multiple locations, is vital to our understanding of global field behaviour during these deviations. We present here high-resolution palaeomagnetic records of the Laschamp excursion obtained from two Ocean Drilling Program (ODP) Sites, 1061 and 1062 on the Blake-Bahama Outer Ridge (ODP Leg 172). High sedimentation rates (˜30-40 cm kyr-1) at these locations allow determination of transitional field behaviour during the excursion. Palaeomagnetic measurements of discrete samples from four cores reveal a single excursional feature, across an interval of 30 cm, associated with a broader palaeointensity low. We determine the age and duration of the Laschamp excursion using a stratigraphy linked to the δ18O record from the Greenland ice cores. This chronology dates the Laschamp excursion at the Blake Ridge to 41.3 ka. The excursion is characterized by rapid transitions (less than 200 yr) between stable normal polarity and a partially reversed polarity state. The palaeointensity record is in good agreement between the two sites, revealing two prominent minima. The first minimum is associated with the Laschamp excursion at 41 ka and the second corresponds to the Mono Lake excursion at ˜35.5 ka. We determine that the directional excursion during the Laschamp at this location was no longer than ˜400 yr, occurring within a palaeointensity minimum that lasted 2000 yr. The Laschamp excursion at this location is much shorter in duration than the Blake and Iceland Basin excursions.

The effect of Kinesio Taping on postural control in subjects with non-specific chronic low back pain.

PubMed

Abbasi, Soheila; Rojhani-Shirazi, Zahra; Shokri, Esmaeil; García-Muro San José, Francisco

2018-04-01

The aim of this study was to investigate the possible alterations in postural control during upright standing in subjects with non-specific chronic low back pain and the effect of Kinesio taping on the postural control. Twenty subjects with non-specific chronic low back pain and twenty healthy subjects participated in this study. The center of pressure excursion was evaluated before the intervention for both groups, and immediately after intervention for the low back pain group. Independent sample t-test, Mann-Whitney test and repeated measure ANOVA were used for the statistical analysis of the data. There were significant differences in the center of pressure excursion between the low back pain group versus the healthy group. The results of the ANOVA demonstrated a statistically significant difference in the mean COP displacement and velocity before Kinesio Taping, immediately after, and 24 h after in the low back pain group. There are poor postural control mechanisms in subjects with non-specific chronic low back pain. Kinesio taping seems to change postural control immediately and have lasting effects until the day after. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Role of Arch Compression and Metatarsophalangeal Joint Dynamics in Modulating Plantar Fascia Strain in Running

PubMed Central

McDonald, Kirsty A.; Stearne, Sarah M.; Alderson, Jacqueline A.; North, Ian; Pires, Neville J.; Rubenson, Jonas

2016-01-01

Elastic energy returned from passive-elastic structures of the lower limb is fundamental in lowering the mechanical demand on muscles during running. The purpose of this study was to investigate the two length-modulating mechanisms of the plantar fascia, namely medial longitudinal arch compression and metatarsophalangeal joint (MPJ) excursion, and to determine how these mechanisms modulate strain, and thus elastic energy storage/return of the plantar fascia during running. Eighteen runners (9 forefoot and 9 rearfoot strike) performed three treadmill running trials; unrestricted shod, shod with restricted arch compression (via an orthotic-style insert), and barefoot. Three-dimensional motion capture and ground reaction force data were used to calculate lower limb kinematics and kinetics including MPJ angles, moments, powers and work. Estimates of plantar fascia strain due to arch compression and MPJ excursion were derived using a geometric model of the arch and a subject-specific musculoskeletal model of the plantar fascia, respectively. The plantar fascia exhibited a typical elastic stretch-shortening cycle with the majority of strain generated via arch compression. This strategy was similar in fore- and rear-foot strike runners. Restricting arch compression, and hence the elastic-spring function of the arch, was not compensated for by an increase in MPJ-derived strain. In the second half of stance the plantar fascia was found to transfer energy between the MPJ (energy absorption) and the arch (energy production during recoil). This previously unreported energy transfer mechanism reduces the strain required by the plantar fascia in generating useful positive mechanical work at the arch during running. PMID:27054319

Mass breakdown model of solar-photon sail shuttle: The case for Mars

NASA Astrophysics Data System (ADS)

Vulpetti, Giovanni; Circi, Christian

2016-02-01

The main aim of this paper is to set up a many-parameter model of mass breakdown to be applied to a reusable Earth-Mars-Earth solar-photon sail shuttle, and analyze the system behavior in two sub-problems: (1) the zero-payload shuttle, and (2) given the sailcraft sail loading and the gross payload mass, find the sail area of the shuttle. The solution to the subproblem-1 is of technological and programmatic importance. The general analysis of subproblem-2 is presented as a function of the sail side length, system mass, sail loading and thickness. In addition to the behaviors of the main system masses, useful information for future work on the sailcraft trajectory optimization is obtained via (a) a detailed mass model for the descent/ascent Martian Excursion Module, and (b) the fifty-fifty solution to the sailcraft sail loading breakdown equation. Of considerable importance is the evaluation of the minimum altitude for the rendezvous between the ascent rocket vehicle and the solar-photon sail propulsion module, a task performed via the Mars Climate Database 2014-2015. The analysis shows that such altitude is 300 km; below it, the atmospheric drag prevails over the solar-radiation thrust. By this value, an example of excursion module of 1500 kg in total mass is built, and the sailcraft sail loading and the return payload are calculated. Finally, the concept of launch opportunity-wide for a shuttle driven by solar-photon sail is introduced. The previous fifty-fifty solution may be a good initial guess for the trajectory optimization of this type of shuttle.

The Role of Arch Compression and Metatarsophalangeal Joint Dynamics in Modulating Plantar Fascia Strain in Running.

PubMed

McDonald, Kirsty A; Stearne, Sarah M; Alderson, Jacqueline A; North, Ian; Pires, Neville J; Rubenson, Jonas

2016-01-01

Elastic energy returned from passive-elastic structures of the lower limb is fundamental in lowering the mechanical demand on muscles during running. The purpose of this study was to investigate the two length-modulating mechanisms of the plantar fascia, namely medial longitudinal arch compression and metatarsophalangeal joint (MPJ) excursion, and to determine how these mechanisms modulate strain, and thus elastic energy storage/return of the plantar fascia during running. Eighteen runners (9 forefoot and 9 rearfoot strike) performed three treadmill running trials; unrestricted shod, shod with restricted arch compression (via an orthotic-style insert), and barefoot. Three-dimensional motion capture and ground reaction force data were used to calculate lower limb kinematics and kinetics including MPJ angles, moments, powers and work. Estimates of plantar fascia strain due to arch compression and MPJ excursion were derived using a geometric model of the arch and a subject-specific musculoskeletal model of the plantar fascia, respectively. The plantar fascia exhibited a typical elastic stretch-shortening cycle with the majority of strain generated via arch compression. This strategy was similar in fore- and rear-foot strike runners. Restricting arch compression, and hence the elastic-spring function of the arch, was not compensated for by an increase in MPJ-derived strain. In the second half of stance the plantar fascia was found to transfer energy between the MPJ (energy absorption) and the arch (energy production during recoil). This previously unreported energy transfer mechanism reduces the strain required by the plantar fascia in generating useful positive mechanical work at the arch during running.

Multiple Ejection Effects Analysis

DTIC Science & Technology

1981-08-01

in future designs . Accession For * I N’IS CRA&I PTIV TAB\\ U:,zmnounced Ja St if ic ft IonL- 1) i tributIon/ Availability Codes Avail and/or )Ibt...between aircraft separation and drogue line stretch. In the case I of the crew module, design changes were eventually adopted to provide a stable...system, and the attitude excursions are very mild. The ejection seat system underwent an important design change because of high-speed aerodynamic

Kilovoltage Intrafraction Monitoring for Prostate Intensity Modulated Arc Therapy: First Clinical Results

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

Ng, Jin Aun; Institute of Medical Physics, School of Physics, University of Sydney, New South Wales; Booth, Jeremy T.

2012-12-01

Purpose: Most linear accelerators purchased today are equipped with a gantry-mounted kilovoltage X-ray imager which is typically used for patient imaging prior to therapy. A novel application of the X-ray system is kilovoltage intrafraction monitoring (KIM), in which the 3-dimensional (3D) tumor position is determined during treatment. In this paper, we report on the first use of KIM in a prospective clinical study of prostate cancer patients undergoing intensity modulated arc therapy (IMAT). Methods and Materials: Ten prostate cancer patients with implanted fiducial markers undergoing conventionally fractionated IMAT (RapidArc) were enrolled in an ethics-approved study of KIM. KIM involves acquiringmore » kV images as the gantry rotates around the patient during treatment. Post-treatment, markers in these images were segmented to obtain 2D positions. From the 2D positions, a maximum likelihood estimation of a probability density function was used to obtain 3D prostate trajectories. The trajectories were analyzed to determine the motion type and the percentage of time the prostate was displaced {>=}3, 5, 7, and 10 mm. Independent verification of KIM positional accuracy was performed using kV/MV triangulation. Results: KIM was performed for 268 fractions. Various prostate trajectories were observed (ie, continuous target drift, transient excursion, stable target position, persistent excursion, high-frequency excursions, and erratic behavior). For all patients, 3D displacements of {>=}3, 5, 7, and 10 mm were observed 5.6%, 2.2%, 0.7% and 0.4% of the time, respectively. The average systematic accuracy of KIM was measured at 0.46 mm. Conclusions: KIM for prostate IMAT was successfully implemented clinically for the first time. Key advantages of this method are (1) submillimeter accuracy, (2) widespread applicability, and (3) a low barrier to clinical implementation. A disadvantage is that KIM delivers additional imaging dose to the patient.« less

Comparative in vivo forefoot kinematics of Homo sapiens and Pan paniscus.

PubMed

Griffin, Nicole L; D'Août, Kristiaan; Richmond, Brian; Gordon, Adam; Aerts, Peter

2010-12-01

The human metatarsophalangeal joints play a key role in weight transmission and propulsion during bipedal gait, but at present, the identification of when a habitual, human-like metatarsi-fulcrimating mechanism first appeared in the fossil record is debated. Part of this debate can be attributed to the absence of certain detailed quantitative data distinguishing human and great ape forefoot form and function. The aim of this study is to quantitatively test previous observations that human metatarsophalangeal joints exhibit greater amounts of dorsal excursion (i.e., dorsiflexion) than those of Pan at the terminal stance phase of terrestrial locomotion. Video recordings were made in order to measure sagittal excursions of the medial metatarsophalangeal joints in habitually shod/unshod adult humans and adult bonobos (Pan paniscus). Results indicate that the human first and second metatarsophalangeal joints usually dorsiflex more than those of bonobos. When timing of maximum excursion of the first metatarsophalangeal joint is coupled with existing plantar pressure data, the unique role of the human forefoot as a key site of leverage and weight transmission is highlighted. These results support hypotheses that significant joint functional differences between great apes and humans during gait underlie taxonomic distinctions in trabecular bone architecture of the forefoot. Copyright © 2010 Elsevier Ltd. All rights reserved.

Evidence of Methane Outgassing During MIS3 in the Bering Sea

NASA Astrophysics Data System (ADS)

Cook, M. S.; Keigwin, L. D.

2005-12-01

There are multiple negative excursions in planktonic and benthic foraminifer δ13C in a core from 1467m in the southeast Bering Sea. These excursions occur episodically during the last glacial period, and may coincide with Dansgaard-Oeschger (D-O) events. Measured foraminifer δ13C during the excursions is as low as -14‰ and are probably the result of overgrowths of diagenetic calcium carbonate. We estimate overgrowth δ13C is -23‰, and hypothesize that the occurrence of overgrowths is associated with anaerobic oxidation of biogenic methane. The likely pressure and temperature conditions at this site and during the last glacial period were well within the zone of methane-hydrate stability, so the source of methane is probably not from destabilization of methane hydrate at this depth. The methane may have originated from increased in-situ methanogenesis resulting from greater burial of organic carbon, or from destabilization of methane hydrate at shallower sites near the methane-hydrate stability threshold. Both these scenarios could be active, consistent with the ``Clathrate Gun Hypothesis'' (Kennett et al., 2003), in which there is widespread destabilization of marine methane hydrates during D-O events, where methane gas both is oxidized within the water column and escapes to the atmosphere.

Phase change in liquid face seals

NASA Technical Reports Server (NTRS)

Hughes, W. F.; Winowich, N. S.; Birchak, M. J.; Kennedy, W. C.

1978-01-01

A study is made of boiling (or phase change) in liquid face seals. An appropriate model is set up and approximate solutions obtained. Some practical illustrative examples are given. Major conclusions are that (1) boiling may occur more often than has been suspected particularly when the sealed liquid is near saturation conditions, (2) the temperature variation in a seal clearance region may not be very great and the main reason for boiling is the flashing which occurs as the pressure decreases through the seal clearance, and (3) there are two separate values of the parameter film-thickness/angular-velocity-squared (and associated radii where phase change takes place) which provide the same separating force under a given set of operating conditions. For a given speed seal face excursions about the larger spacing are stable, but excursions about the smaller spacing are unstable, leading to a growth to the larger spacing or a catastrophic collapse.

The Effect of a Non-Gaussian Random Loading on High-Cycle Fatigue of a Thermally Post-Buckled Structure

NASA Technical Reports Server (NTRS)

Rizzi, Stephen A.; Behnke, marlana N.; Przekop, Adam

2010-01-01

High-cycle fatigue of an elastic-plastic beam structure under the combined action of thermal and high-intensity non-Gaussian acoustic loadings is considered. Such loadings can be highly damaging when snap-through motion occurs between thermally post-buckled equilibria. The simulated non-Gaussian loadings investigated have a range of skewness and kurtosis typical of turbulent boundary layer pressure fluctuations in the vicinity of forward facing steps. Further, the duration and steadiness of high excursion peaks is comparable to that found in such turbulent boundary layer data. Response and fatigue life estimates are found to be insensitive to the loading distribution, with the minor exception of cases involving plastic deformation. In contrast, the fatigue life estimate was found to be highly affected by a different type of non-Gaussian loading having bursts of high excursion peaks.

Speed And Power Control Of An Engine By Modulation Of The Load Torque

DOEpatents

Ziph, Benjamin; Strodtman, Scott; Rose, Thomas K

1999-01-26

A system and method of speed and power control for an engine in which speed and power of the engine is controlled by modulation of the load torque. The load torque is manipulated in order to cause engine speed, and hence power to be changed. To accomplish such control, the load torque undergoes a temporary excursion in the opposite direction of the desired speed and power change. The engine and the driven equipment will accelerate or decelerate accordingly as the load torque is decreased or increased, relative to the essentially fixed or constant engine torque. As the engine accelerates or decelerates, its power increases or decreases in proportion.

A comparison of the Greenland ice-core and IntCal timescales through the Laschamp geomagnetic excursion, utilising new 14C data from Tenaghi Philippon, Greece

NASA Astrophysics Data System (ADS)

Staff, Richard; Hardiman, Mark; Bronk Ramsey, Christopher; Hare, Vincent; Koutsodendris, Andreas; Pross, Jörg

2017-04-01

Cosmogenic radionuclides, such as 10Be and 14C, share a common production signal, with their formation in the Earth's upper atmosphere modulated by changes to the geomagnetic field, as well as variations in the intensity of the solar wind. Here, we present 54 14C measurements from a terrestrial fen peat core extracted from the site of Tenaghi Philippon, NE Greece, contiguously spanning the time period between 48,000 and 39,000 cal. BP. Utilising the most pronounced cosmogenic production peak of the last 100,000 years - that associated with the Laschamp geomagnetic excursion circa 41,000 years ago - we exploit this common production signal, comparing Greenland 10Be with our Tenaghi Philippon 14C record, thereby providing a means to assess the concordance between the radiocarbon (IntCal) and Greenland ice-core (GICC05) timescales themselves for this, the oldest portion of the radiocarbon technique.

CPAP Devices for Emergency Prehospital Use: A Bench Study.

PubMed

Brusasco, Claudia; Corradi, Francesco; De Ferrari, Alessandra; Ball, Lorenzo; Kacmarek, Robert M; Pelosi, Paolo

2015-12-01

CPAP is frequently used in prehospital and emergency settings. An air-flow output minimum of 60 L/min and a constant positive pressure are 2 important features for a successful CPAP device. Unlike hospital CPAP devices, which require electricity, CPAP devices for ambulance use need only an oxygen source to function. The aim of the study was to evaluate and compare on a bench model the performance of 3 orofacial mask devices (Ventumask, EasyVent, and Boussignac CPAP system) and 2 helmets (Ventukit and EVE Coulisse) used to apply CPAP in the prehospital setting. A static test evaluated air-flow output, positive pressure applied, and FIO2 delivered by each device. A dynamic test assessed airway pressure stability during simulated ventilation. Efficiency of devices was compared based on oxygen flow needed to generate a minimum air flow of 60 L/min at each CPAP setting. The EasyVent and EVE Coulisse devices delivered significantly higher mean air-flow outputs compared with the Ventumask and Ventukit under all CPAP conditions tested. The Boussignac CPAP system never reached an air-flow output of 60 L/min. The EasyVent had significantly lower pressure excursion than the Ventumask at all CPAP levels, and the EVE Coulisse had lower pressure excursion than the Ventukit at 5, 15, and 20 cm H2O, whereas at 10 cm H2O, no significant difference was observed between the 2 devices. Estimated oxygen consumption was lower for the EasyVent and EVE Coulisse compared with the Ventumask and Ventukit. Air-flow output, pressure applied, FIO2 delivered, device oxygen consumption, and ability to maintain air flow at 60 L/min differed significantly among the CPAP devices tested. Only the EasyVent and EVE Coulisse achieved the required minimum level of air-flow output needed to ensure an effective therapy under all CPAP conditions. Copyright © 2015 by Daedalus Enterprises.

Four faces of baroreflex failure: hypertensive crisis, volatile hypertension, orthostatic tachycardia, and malignant vagotonia

NASA Technical Reports Server (NTRS)

Ketch, Terry; Biaggioni, Italo; Robertson, RoseMarie; Robertson, David

2002-01-01

BACKGROUND: The baroreflex normally serves to buffer blood pressure against excessive rise or fall. Baroreflex failure occurs when afferent baroreceptive nerves or their central connections become impaired. In baroreflex failure, there is loss of buffering ability, and wide excursions of pressure and heart rate occur. Such excursions may derive from endogenous factors such as stress or drowsiness, which result in quite high and quite low pressures, respectively. They may also derive from exogenous factors such as drugs or environmental influences. METHODS AND RESULTS: Impairment of the baroreflex may produce an unusually broad spectrum of clinical presentations; with acute baroreflex failure, a hypertensive crisis is the most common presentation. Over succeeding days to weeks, or in the absence of an acute event, volatile hypertension with periods of hypotension occurs and may continue for many years, usually with some attenuation of pressor surges and greater prominence of depressor valleys during long-term follow-up. With incomplete loss of baroreflex afferents, a mild syndrome of orthostatic tachycardia or orthostatic intolerance may appear. Finally, if the baroreflex failure occurs without concomitant destruction of the parasympathetic efferent vagal fibers, a resting state may lead to malignant vagotonia with severe bradycardia and hypotension and episodes of sinus arrest. CONCLUSIONS: Although baroreflex failure is not the most common cause of the above conditions, correct differentiation from other cardiovascular disorders is important, because therapy of baroreflex failure requires specific strategies, which may lead to successful control.

Practices and Methods for Actualization of the Scientific Information in Art Excursions (Excursions and Cultural Heritage in the Contemporary World)

ERIC Educational Resources Information Center

Portnova, Tatiana V.

2016-01-01

The paper deals with various practices and methods for actualization of the scientific information in art excursions. The modern society is characterized by commitment to information richness. The range of cultural and historical materials used as the basis for art excursions is really immense. However if to consider the number of excursions with…

Validation of the Inverted Pendulum Model in standing for transtibial prosthesis users.

PubMed

Rusaw, David F; Ramstrand, Simon

2016-01-01

Often in balance assessment variables associated with the center of pressure are used to draw conclusions about an individual's balance. Validity of these conclusions rests upon assumptions that movement of the center of pressure is inter-dependent on movement of the center of mass. This dependency is mechanical and is referred to as the Inverted Pendulum Model. The following study aimed to validate this model both kinematically and kinetically, in transtibial prosthesis users and a control group. Prosthesis users (n=6) and matched control participants (n=6) stood quietly while force and motion data were collected under three conditions (eyes-open, eyes-closed, and weight-bearing feedback). Correlation coefficients were used to investigate the relationships between height and excursion of markers and center of masses in mediolateral/anteroposterior-directions, difference between center of pressure and center of mass and the center of mass acceleration in mediolateral/anteroposterior directions, magnitude of mediolateral/anteroposterior-component forces and center of mass acceleration, angular position of ankle and excursion in mediolateral/anteroposterior-directions, and integrated force signals. Results indicate kinematic validity of similar magnitudes (mean (SD) marker-displacement) between prosthesis users and control group for mediolateral- (r=0.77 (0.17); 0.74 (0.19)) and anteroposterior-directions (r=0.88 (0.18); 0.88 (0.19)). Correlation between difference of center of pressure and center of mass and the center of mass acceleration was negligible on the prosthetic side (r = 0.08 (0.06)) vs. control group (r=-0.51(0.13)). Results indicate kinematic validity of the Inverted Pendulum Model in transtibial prosthesis users but kinetic validity is questionable, particularly on the side with a prosthesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Scalar excursions in large-eddy simulations

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

Matheou, Georgios; Dimotakis, Paul E.

Here, the range of values of scalar fields in turbulent flows is bounded by their boundary values, for passive scalars, and by a combination of boundary values, reaction rates, phase changes, etc., for active scalars. The current investigation focuses on the local conservation of passive scalar concentration fields and the ability of the large-eddy simulation (LES) method to observe the boundedness of passive scalar concentrations. In practice, as a result of numerical artifacts, this fundamental constraint is often violated with scalars exhibiting unphysical excursions. The present study characterizes passive-scalar excursions in LES of a shear flow and examines methods formore » diagnosis and assesment of the problem. The analysis of scalar-excursion statistics provides support of the main hypothesis of the current study that unphysical scalar excursions in LES result from dispersive errors of the convection-term discretization where the subgrid-scale model (SGS) provides insufficient dissipation to produce a sufficiently smooth scalar field. In the LES runs three parameters are varied: the discretization of the convection terms, the SGS model, and grid resolution. Unphysical scalar excursions decrease as the order of accuracy of non-dissipative schemes is increased, but the improvement rate decreases with increasing order of accuracy. Two SGS models are examined, the stretched-vortex and a constant-coefficient Smagorinsky. Scalar excursions strongly depend on the SGS model. The excursions are significantly reduced when the characteristic SGS scale is set to double the grid spacing in runs with the stretched-vortex model. The maximum excursion and volume fraction of excursions outside boundary values show opposite trends with respect to resolution. The maximum unphysical excursions increase as resolution increases, whereas the volume fraction decreases. The reason for the increase in the maximum excursion is statistical and traceable to the number of grid points (sample size) which increases with resolution. In contrast, the volume fraction of unphysical excursions decreases with resolution because the SGS models explored perform better at higher grid resolution.« less

Scalar excursions in large-eddy simulations

DOE PAGES

Matheou, Georgios; Dimotakis, Paul E.

2016-08-31

Here, the range of values of scalar fields in turbulent flows is bounded by their boundary values, for passive scalars, and by a combination of boundary values, reaction rates, phase changes, etc., for active scalars. The current investigation focuses on the local conservation of passive scalar concentration fields and the ability of the large-eddy simulation (LES) method to observe the boundedness of passive scalar concentrations. In practice, as a result of numerical artifacts, this fundamental constraint is often violated with scalars exhibiting unphysical excursions. The present study characterizes passive-scalar excursions in LES of a shear flow and examines methods formore » diagnosis and assesment of the problem. The analysis of scalar-excursion statistics provides support of the main hypothesis of the current study that unphysical scalar excursions in LES result from dispersive errors of the convection-term discretization where the subgrid-scale model (SGS) provides insufficient dissipation to produce a sufficiently smooth scalar field. In the LES runs three parameters are varied: the discretization of the convection terms, the SGS model, and grid resolution. Unphysical scalar excursions decrease as the order of accuracy of non-dissipative schemes is increased, but the improvement rate decreases with increasing order of accuracy. Two SGS models are examined, the stretched-vortex and a constant-coefficient Smagorinsky. Scalar excursions strongly depend on the SGS model. The excursions are significantly reduced when the characteristic SGS scale is set to double the grid spacing in runs with the stretched-vortex model. The maximum excursion and volume fraction of excursions outside boundary values show opposite trends with respect to resolution. The maximum unphysical excursions increase as resolution increases, whereas the volume fraction decreases. The reason for the increase in the maximum excursion is statistical and traceable to the number of grid points (sample size) which increases with resolution. In contrast, the volume fraction of unphysical excursions decreases with resolution because the SGS models explored perform better at higher grid resolution.« less

Exp.55_US_EVA_49_03_2018_088_1430_633697

NASA Image and Video Library

2018-03-30

SPACE STATION CREW WALKS IN SPACE TO UPGRADE SYSTEMS Veteran NASA astronauts Drew Feustel and Ricky Arnold ventured outside the International Space Station March 29 clad in U.S. spacesuits to install wireless communications antennas on the Tranquility module, replace a camera system on the port truss and remove suspect hoses from a cooling system. The excursion was the 209th in space station history for assembly, maintenance and upgrades, the seventh in Feustel’s career and the third for Arnold.

Exp.55_US_EVA_49_02_2018_088_1230_633620

NASA Image and Video Library

2018-03-30

SPACE STATION CREW WALKS IN SPACE TO UPGRADE SYSTEMS----------------------Veteran NASA astronauts Drew Feustel and Ricky Arnold ventured outside the International Space Station March 29 clad in U.S. spacesuits to install wireless communications antennas on the Tranquility module, replace a camera system on the port truss and remove suspect hoses from a cooling system. The excursion was the 209th in space station history for assembly, maintenance and upgrades, the seventh in Feustel’s career and the third for Arnold.

EXP.55_US_EVA_49_04_2018_088_1630_633783

NASA Image and Video Library

2018-04-02

SPACE STATION CREW WALKS IN SPACE TO UPGRADE SYSTEMS-----------------------Veteran NASA astronauts Drew Feustel and Ricky Arnold ventured outside the International Space Station March 29 clad in U.S. spacesuits to install wireless communications antennas on the Tranquility module, replace a camera system on the port truss and remove suspect hoses from a cooling system. The excursion was the 209th in space station history for assembly, maintenance and upgrades, the seventh in Feustel’s career and the third for Arnold.

Exp.55_US_EVA_49_01_2018_088_1029_633551

NASA Image and Video Library

2018-03-30

SPACE STATION CREW WALKS IN SPACE TO UPGRADE SYSTEMS----------------Veteran NASA astronauts Drew Feustel and Ricky Arnold ventured outside the International Space Station March 29 clad in U.S. spacesuits to install wireless communications antennas on the Tranquility module, replace a camera system on the port truss and remove suspect hoses from a cooling system. The excursion was the 209th in space station history for assembly, maintenance and upgrades, the seventh in Feustel’s career and the third for Arnold.

Design of equipment for lunar dust removal

NASA Technical Reports Server (NTRS)

Belden, Lacy; Cowan, Kevin; Kleespies, Hank; Ratliff, Ryan; Shah, Oniell; Shelburne, Kevin

1991-01-01

NASA has a long range goal of constructing a fully equipped, manned lunar base on the near side of the moon by the year 2015. During the Apollo Missions, lunar dust coated and fouled equipment surfaces and mechanisms exposed to the lunar environment. In addition, the atmosphere and internal surfaces of the lunar excursion module were contaminated by lunar dust which was brought in on articles passed through the airlock. Consequently, the need exists for device or appliance to remove lunar dust from surfaces of material objects used outside of the proposed lunar habitat. Additionally, several concepts were investigated for preventing the accumulation of lunar dust on mechanisms and finished surfaces. The character of the dust and the lunar environment present unique challenges for the removal of contamination from exposed surfaces. In addition to a study of lunar dust adhesion properties, the project examines the use of various energy domains for removing the dust from exposed surfaces. Also, prevention alternatives are examined for systems exposed to lunar dust. A concept utilizing a pressurized gas is presented for dust removal outside of an atmospherically controlled environment. The concept consists of a small astronaut/robotic compatible device which removes dust from contaminated surfaces by a small burst of gas.

Mid-Brunhes magnetic excursions in marine isotope stages 9, 13, 14, and 15 (286, 495, 540, and 590 ka) at North Atlantic IODP Sites U1302/3, U1305, and U1306

NASA Astrophysics Data System (ADS)

Channell, J. E. T.

2017-02-01

Integrated Ocean Drilling Program (IODP) Site U1302/3 (Orphan Knoll, off Newfoundland) recorded magnetic excursions in marine isotope stages (MIS) 9a (at 286 ka) and 13a (at 495 ka). Sites U1306 and U1305 (Eirik Drift, off SE Greenland) record excursions in MIS 14a/b (at 540 ka) and 15b/c (at 590 ka). In the excursion intervals, magnetic measurements of continuous "u-channel" samples from multiple holes within site are augmented by measurements of cubic (8 cm3) discrete samples. The excursions lie in relative paleointensity (RPI) minima at each site and in RPI reference stacks, and correspond to dated intervals of 10Be overproduction in other deep-sea sediment records. Although observed at multiple holes at each site, and from u-channel and discrete samples, the excursions are not observed at all three sites, and often at only one of the three sites. Sporadic recording of these magnetic excursions, and excursions in general, is attributed to a combination of filtering by the process of acquisition of detrital remanent magnetization (DRM), postdepositional overprint of weak excursion magnetizations, the millennial or even centennial duration of directional excursions, and nonuniform sedimentation rates at these timescales in North Atlantic sediment drifts.

High-resolution palaeomagnetic records of the Laschamp geomagnetic excursion from the Blake Ridge

NASA Astrophysics Data System (ADS)

Mac Niocaill, C.; Bourne, M. D.; Thomas, A. L.; Henderson, G. M.

2013-05-01

Geomagnetic excursions are brief (1000s of years) deviations in geomagnetic field behaviour from that expected during 'normal secular' variation. The Laschamp excursion (~41 ka) was a global deviation in geomagnetic field behaviour. Previously published records suggest rapid changes in field direction and a concurrent substantial decrease in field intensity. Accurate dating of excursions and determinations of their durations from multiple locations is vital to our understanding to global field behaviour during these deviations. We present here high-resolution palaeomagnetic records of the Laschamp excursion obtained from two Ocean Drilling Program (ODP) Sites 1061 and 1062 on the Blake-Bahama Outer Ridge (ODP Leg 172) Relatively high sedimentation rates (~30-40 cm kyr-1) at these locations allow the determination of transitional field behaviour during the excursion. Despite their advantages, sedimentary records can be limited by the potential for unrecognized variations in sedimentation rates between widely spaced age-constrained boundaries. Rather than assuming a constant sedimentation rate between assigned age tie-points, we employ measurements of the concentration of 230Thxs in the sediment. 230Thxs is a constant flux proxy and may be used to assess variations in the sedimentation rates through the core sections of interest. Following this approach, we present a new age model for Site 1061 that allows us to better determine the temporal behaviour of the Laschamp excursion with greater accuracy and known uncertainty. Palaeomagnetic measurements of discrete samples from four cores reveal a single excursional feature, across an interval of 30 cm, associated with a broader palaeointensity low. The excursion is characterised by rapid transitions (less than 200 years) between a stable normal polarity and a partially-reversed, polarity. Peaks in inclination either side of the directional excursion indicate periods of time when the local field is dominated by vertical flux patches. Similar behaviour has been observed in records of the Iceland Basin Excursion from the same region. The palaeointensity record is in good agreement between the two sites. The palaeointensity record shows two prominent minima, the first associated with the Laschamp excursion at 41 ka and the second at ~34 ka, possibly associated with the elusive 'Mono-Lake' excursion. Similar field intensity behaviour has been observed during the Blake excursion suggesting that the geomagnetic field stability may be reduced for relatively long durations, potentially up to tens of thousands of years. Using the 230Thxs derived sedimentation rate, we determine that the directional excursion at this location was no longer than ~400 years, occurring within a palaeointensity low lasting 2000 years. We compare this record with previously published records of the Blake and Iceland Basin Excursions from nearby locations. The Laschamp excursion at this location appears to be much shorter in duration than the Blake and Iceland Basin excursions.

Nociceptive vascular reflexes evoked by scorpion venom modulate cardiorespiratory parameters involving vanilloid receptor 1 in anaesthetised rats.

PubMed

Singh, Sanjeev K; Deshpande, Shripad B

2009-02-27

Involvement of vanilloid and 5-HT(3) receptors in the cardiorespiratory reflexes evoked by intra-arterial (i.a.) injection of Mesobuthus tamulus (BT) venom was examined. In anaesthetised rats, blood pressure, respiratory excursions and ECG were recorded for 60min after the injection of venom in the absence or presence of antagonists. Injection of BT venom (1mg/kg, i.a.) produced alterations in respiratory frequency (RF), blood pressure (BP) and heart rate (HR). The changes in RF were manifested as immediate increase (40%) followed by a decrease (40%) and subsequent sustained increase (60%). In case of BP, the increase began around 40s, peaked at 5min (50%) and remained above the initial level subsequently. The bradycardiac response began around 5min which peaked (50% of the initial) around 25min and remained at that level. Thus, exhibiting immediate-tachypnoeic, intermediate-hypertensive and delayed-bradycardiac responses. Pretreatment with lignocaine, blocked the respiratory responses and attenuated the pressor responses evoked by venom. Pretreatment with capsazepine, vanilloid receptor 1 (VR1) antagonist, antagonized all the three parameters of cardiorespiratory responses evoked by venom. Whereas, ondansetron (5-HT(3) antagonist) attenuated the pressor and bradycardiac responses significantly but not the respiratory responses. These observations indicate that the cardiorespiratory changes induced by intra-arterial injection of venom are carried by afferents in addition to somatic nerves, involving mainly VR1 receptors and partially by 5-HT(3) receptors.

Integration Process for the Habitat Demonstration Unit

NASA Technical Reports Server (NTRS)

Gill, Tracy; Merbitz, Jerad; Kennedy, Kriss; Tri, Terry; Howe, A. Scott

2010-01-01

The Habitat Demonstration Unit (HDU) is an experimental exploration habitat technology and architecture test platform designed for analog demonstration activities The HDU project has required a team to integrate a variety of contributions from NASA centers and outside collaborators and poses a challenge in integrating these disparate efforts into a cohesive architecture To complete the development of the HDU from conception in June 2009 to rollout for operations in July 2010, a cohesive integration strategy has been developed to integrate the various systems of HDU and the payloads, such as the Geology Lab, that those systems will support The utilization of interface design standards and uniquely tailored reviews have allowed for an accelerated design process Scheduled activities include early fit-checks and the utilization of a Habitat avionics test bed prior to equipment installation into HDU A coordinated effort to utilize modeling and simulation systems has aided in design and integration concept development Modeling tools have been effective in hardware systems layout, cable routing and length estimation, and human factors analysis Decision processes on the shell development including the assembly sequence and the transportation have been fleshed out early on HDU to maximize the efficiency of both integration and field operations Incremental test operations leading up to an integrated systems test allows for an orderly systems test program The HDU will begin its journey as an emulation of a Pressurized Excursion Module (PEM) for 2010 field testing and then may evolve to a Pressurized Core Module (PCM) for 2011 and later field tests, depending on agency architecture decisions The HDU deployment will vary slightly from current lunar architecture plans to include developmental hardware and software items and additional systems called opportunities for technology demonstration One of the HDU challenges has been designing to be prepared for the integration of presently unanticipated systems Results of the HDU field tests will influence future designs of habitat systems.

Acoustic, respiratory kinematic and electromyographic effects of vocal training

NASA Astrophysics Data System (ADS)

Mendes, Ana Paula De Brito Garcia

The longitudinal effects of vocal training on the respiratory, phonatory and articulatory systems were investigated in this study. During four semesters, fourteen voice major students were recorded while speaking and singing. Acoustic, temporal, respiratory kinematic and electromyographic parameters were measured to determine changes in the three systems as a function of vocal training. Acoustic measures of the speaking voice included fundamental frequency, sound pressure level (SPL), percent jitter and shimmer, and harmonic-to-noise ratio. Temporal measures included duration of sentences, diphthongs and the closure durations of stop consonants. Acoustic measures of the singing voice included fundamental frequency and sound pressure level of the phonational range, vibrato pulses per second, vibrato amplitude variation and the presence of the singer's formant. Analysis of the data revealed that vocal training had a significant effect on the singing voice. Fundamental frequency and SPL of the 90% level and 90--10% of the phonational range increased significantly during four semesters of vocal training. Physiological data was collected from four subjects during three semesters of vocal training. Respiratory kinematic measures included lung volume, rib cage and abdominal excursions extracted from spoken sung samples. Descriptive statistics revealed that rib cage and abdominal excursions increased from the 1st to the 2nd semester and decrease from the 2nd to the 3rd semester of vocal training. Electromyographic measures of the pectoralis major, rectus abdominis and external obliques muscles revealed that burst duration means decreased from the 1st to the 2nd semester and increased from the 2nd to the 3rd semester. Peak amplitude means increased from the 1st to the 2nd and decreased from the 2nd to the 3rd semester of vocal training. Chest wall excursions and muscle force generation of the three muscles increased as the demanding level and the length of the phonatory tasks increased.

Boundary lubrication of heterogeneous surfaces and the onset of cavitation in frictional contacts

PubMed Central

Savio, Daniele; Pastewka, Lars; Gumbsch, Peter

2016-01-01

Surfaces can be slippery or sticky depending on surface chemistry and roughness. We demonstrate in atomistic simulations that regular and random slip patterns on a surface lead to pressure excursions within a lubricated contact that increase quadratically with decreasing contact separation. This is captured well by a simple hydrodynamic model including wall slip. We predict with this model that pressure changes for larger length scales and realistic frictional conditions can easily reach cavitation thresholds and significantly change the load-bearing capacity of a contact. Cavitation may therefore be the norm, not the exception, under boundary lubrication conditions. PMID:27051871

Rapid directional changes associated with a 6.5 kyr-long Blake geomagnetic excursion at the Blake-Bahama Outer Ridge

NASA Astrophysics Data System (ADS)

Bourne, Mark; Mac Niocaill, Conall; Thomas, Alex L.; Knudsen, Mads Faurschou; Henderson, Gideon M.

2012-06-01

Geomagnetic excursions are recognized as intrinsic features of the Earth's magnetic field. High-resolution records of field behaviour, captured in marine sedimentary cores, present an opportunity to determine the temporal and geometric character of the field during geomagnetic excursions and provide constraints on the mechanisms producing field variability. We present here the highest resolution record yet published of the Blake geomagnetic excursion (∼125 ka) measured in three cores from Ocean Drilling Program (ODP) Site 1062 on the Blake-Bahama Outer Ridge. The Blake excursion has a controversial structure and timing but these cores have a sufficiently high sedimentation rate (∼10 cm ka-1) to allow detailed reconstruction of the field behaviour at this site during the excursion. Palaeomagnetic measurements of the cores reveal rapid transitions (<500 yr) between the contemporary stable normal polarity and a completely reversed state of long duration which spans a stratigraphic interval of 0.7 m. We determine the duration of the reversed state during the Blake excursion using oxygen isotope stratigraphy, combined with 230Th excess measurements to assess variations in the sedimentation rates through the sections of interest. This provides an age and duration for the Blake excursion with greater accuracy and with constrained uncertainty. We date the directional excursion as falling between 129 and 122 ka with a duration for the deviation of 6.5±1.3 kyr. The long duration of this interval and the fully reversed field suggest the existence of a pseudo-stable, reversed dipole field component during the excursion and challenge the idea that excursions are always of short duration.

High-resolution palaeomagnetic records of the Laschamp geomagnetic excursion from ODP Sites 1061 and 1062

NASA Astrophysics Data System (ADS)

Bourne, M. D.; Henderson, G. M.; Thomas, A. L.; Mac Niocaill, C.

2012-12-01

The Laschamp geomagnetic excursion (~41 ka) was a brief global deviation in geomagnetic field behaviour from that expected during normal secular variation. Previously published records suggest rapid changes in field direction and a concurrent substantial decrease in field intensity. We present here high-resolution palaeomagnetic records of the Laschamp excursion obtained from two Ocean Drilling Program (ODP) Sites 1061 and 1062 on the Blake-Bahama Outer Ridge (ODP Leg 172) and compare this record with previously published records of the Blake and Iceland Basin Excursions. Relatively high sedimentation rates (>10 cm kyr-1) at these locations allow the determination of transitional field behaviour during the excursion. Rather than assuming a constant sedimentation rate between assigned age tie-points, we employ measurements of 230Thxs concentration in the sediment to assess variations in the sedimentation rates through the core sections of interest. This allows us to better determine the temporal behaviour of the Laschamp excursion with greater accuracy and known uncertainty. The Laschamp excursion at this location appears to be much shorter in duration than the Blake and Iceland Basin excursions. Palaeomagnetic measurements of discrete samples from four cores reveal a single excursional feature, across an interval of 30 cm, associated with a broader palaeointensity low. The excursion is characterised by rapid transitions (less than 500 years) between a stable normal polarity and a partially-reversed, polarity. Peaks in inclination either side of the directional excursion indicate periods of time when the local field is dominated by vertical flux patches. Similar behaviour has been observed in records of the Iceland Basin Excursion from the same region. The palaeointensity record is in good agreement between the two sites. The palaeointensity record shows two minima, where the second dip in intensity is associated with a more limited directional deviation. Similar field intensity behaviour has been observed during the Blake excursion suggesting that the geomagnetic field stability may be reduced for relatively long durations, potentially up to tens of thousands of years.

A Whale of an Interest in Sea Creatures: The Learning Potential of Excursions

ERIC Educational Resources Information Center

Hedges, Helen

2004-01-01

Excursions, or field trips, are a common component of early childhood programs, seen as a means of enriching the curriculum by providing experiences with people, places, and things in the community. Although excursions have been used as a framework for research on children's memory development, research on the efficacy of excursions in terms of…

Video game-based exercises for balance rehabilitation: a single-subject design.

PubMed

Betker, Aimee L; Szturm, Tony; Moussavi, Zahra K; Nett, Cristabel

2006-08-01

To investigate whether coupling foot center of pressure (COP)-controlled video games to standing balance exercises will improve dynamic balance control and to determine whether the motivational and challenging aspects of the video games would increase a subject's desire to perform the exercises and complete the rehabilitation process. Case study, pre- and postexercise. University hospital outpatient clinic. A young adult with excised cerebellar tumor, 1 middle-aged adult with single right cerebrovascular accident, and 1 middle-aged adult with traumatic brain injury. A COP-controlled, video game-based exercise system. The following were calculated during 12 different tasks: the number of falls, range of COP excursion, and COP path length. Postexercise, subjects exhibited a lower fall count, decreased COP excursion limits for some tasks, increased practice volume, and increased attention span during training. The COP-controlled video game-based exercise regime motivated subjects to increase their practice volume and attention span during training. This in turn improved subjects' dynamic balance control.

Preseismic Velocity Changes Observed from Active Source Monitoringat the Parkfield SAFOD Drill Site

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

Daley, Thomas; Niu, Fenglin; Silver, Paul G.

2008-06-10

Measuring stress changes within seismically active fault zones has been a long-sought goal of seismology. Here we show that such stress changes are measurable by exploiting the stress dependence of seismic wave speed from an active source cross-well experiment conducted at the SAFOD drill site. Over a two-month period we observed an excellent anti-correlation between changes in the time required for an S wave to travel through the rock along a fixed pathway--a few microseconds--and variations in barometric pressure. We also observed two large excursions in the traveltime data that are coincident with two earthquakes that are among those predictedmore » to produce the largest coseismic stress changes at SAFOD. Interestingly, the two excursions started approximately 10 and 2 hours before the events, respectively, suggesting that they may be related to pre-rupture stress induced changes in crack properties, as observed in early laboratory studies.« less

The effect of muscle excursion on muscle recovery after tendon repair in a neglected tendon injury: a study in rabbit soleus muscles.

PubMed

Jeon, Suk Ha; Chung, Moon Sang; Baek, Goo Hyun; Lee, Young Ho; Gong, Hyun Sik

2011-01-01

We attempted to determine whether muscle excursion observed during operation can be a prognostic indicator of muscle recovery after delayed tendon repair in a rabbit soleus model. Eighteen rabbits underwent tenotomy of the soleus muscles bilaterally and were divided into three groups according to the period from tenotomy to repair. The tendons of each group were repaired 2, 4, and 6 weeks after tenotomy. The excursion of each soleus muscle was measured at the time of tenotomy (baseline), at 2, 4, 6 weeks after tenotomy, and 8 weeks after tendon repair. The amount of muscle recovery after tendon repair in terms of muscle excursion independently depended on the timing of repair and on the muscle excursion observed during repair. The regression model predicted that the muscle excursion recovered on average by 0.6% as the muscle excursion at the time of repair increased by 1% after adjusting for the timing of repair. This study suggests that measuring the muscle excursion during tendon repair may help physicians estimate the potential of muscle recovery in cases of delayed tendon repair. Copyright © 2010 Orthopaedic Research Society.

The Excursion Set Theory of Halo Mass Functions, Halo Clustering, and Halo Growth

NASA Astrophysics Data System (ADS)

Zentner, Andrew R.

I review the excursion set theory with particular attention toward applications to cold dark matter halo formation and growth, halo abundance, and halo clustering. After a brief introduction to notation and conventions, I begin by recounting the heuristic argument leading to the mass function of bound objects given by Press and Schechter. I then review the more formal derivation of the Press-Schechter halo mass function that makes use of excursion sets of the density field. The excursion set formalism is powerful and can be applied to numerous other problems. I review the excursion set formalism for describing both halo clustering and bias and the properties of void regions. As one of the most enduring legacies of the excursion set approach and one of its most common applications, I spend considerable time reviewing the excursion set theory of halo growth. This section of the review culminates with the description of two Monte Carlo methods for generating ensembles of halo mass accretion histories. In the last section, I emphasize that the standard excursion set approach is the result of several simplifying assumptions. Dropping these assumptions can lead to more faithful predictions and open excursion set theory to new applications. One such assumption is that the height of the barriers that define collapsed objects is a constant function of scale. I illustrate the implementation of the excursion set approach for barriers of arbitrary shape. One such application is the now well-known improvement of the excursion set mass function derived from the "moving" barrier for ellipsoidal collapse. I also emphasize that the statement that halo accretion histories are independent of halo environment in the excursion set approach is not a general prediction of the theory. It is a simplifying assumption. I review the method for constructing correlated random walks of the density field in the more general case. I construct a simple toy model to illustrate that excursion set theory (with a constant barrier height) makes a simple and general prediction for the relation between halo accretion histories and the large-scale environments of halos: regions of high density preferentially contain late-forming halos and conversely for regions of low density. I conclude with a brief discussion of the importance of this prediction relative to recent numerical studies of the environmental dependence of halo properties.

A Comparison of two Brunhes Chron Geomagnetic Excursions Recorded by Neighbouring North Atlantic Sites (ODP Sites 1062 and 1063)

NASA Astrophysics Data System (ADS)

Bourne, M.; Mac Niocaill, C.; Knudsen, M. F.; Thomas, A. L.; Henderson, G. M.

2012-04-01

A full picture of geomagnetic field behaviour during the Blake excursion is currently limited by a paucity of robust, high-resolution records of this ambiguous event. Some records seem to point towards a 'double-excursion' character whilst others fail to record the Blake excursion at all. We present here a high-resolution record of the Blake excursion obtained from Ocean Drilling Program (ODP) Site 1062 on the Blake Outer Ridge (ODP Leg 172). Palaeomagnetic measurements in three cores reveal a single excursional feature associated with a broad palaeointensity low, characterised by rapid transitions (less than 500 years) between a stable normal polarity and a fully-reversed, pseudo-stable polarity. A relatively high sedimentation rate (~10 cm kyr-1) allows the determination of transitional field behaviour during the excursion. Rather than assuming a constant sedimentation rate between assigned age tie-points, we employ measurements of 230Thxs concentrations in the sediment to assess variations in the sedimentation rates through the core sections of interest. This allows us to determine an age and duration for the two excursions with greater accuracy and known uncertainty. Our new age model gives an age of 127 ka for the midpoint of the Blake event at Site 1062. The age model also gives a duration for the directional excursion of 7.1±1.6 kyr. This duration is similar to that previously reported for the Iceland Basin Excursion (~185 ka) from the nearby Bermuda Rise (ODP Site 1063), which recorded a ~7-8 kyr event. Similarly, a high sedimentation rate (10-15 cm kyr-1) at this site allows a high-resolution reconstruction of the geomagnetic field behaviour during the Iceland Basin Excursion. The Site 1063 palaeomagnetic record suggests more complicated behaviour than that of the Blake excursion at Site 1062. Instead, transitional VGP paths are characterised by stop-and-go behaviour between VGP clusters that may be related to long-standing thermo-dynamic features of the core-mantle system. The long duration of fully reversed directions at the two sites is somewhat longer than that typically assumed for excursions and appears to suggest that there may be a degree of stability associated with the two excursional events. We will present a comparison of the geomagnetic field behaviour of the two excursions as recorded at these two sites.

Laryngeal and phrenic nerve involvement in a patient with hereditary neuropathy with liability to pressure palsies (HNPP).

PubMed

Cortese, A; Piccolo, G; Lozza, A; Schreiber, A; Callegari, I; Moglia, A; Alfonsi, E; Pareyson, D

2016-07-01

Lower cranial and phrenic nerve involvement is exceptional in hereditary neuropathy with liability to pressure palsies (HNPP). Here we report the occurrence of reversible laryngeal and phrenic nerve involvement in a patient with HNPP. The patient recalled several episodes of reversible weakness and numbness of his feet and hands since the age of 30 years. His medical history was uneventful, apart from chronic obstructive pulmonary disease (COPD). At age 44, following severe weight loss, he presented with progressive dysphonia and hoarseness. EMG of cricoarytenoid and thyroarytenoid muscles and laryngeal fibroscopy confirmed vocal cord paralysis. These speech disturbances gradually regressed. Two years later, he reported rapidly worsening dyspnea. Electroneurography showed increased distal latency of the right phrenic nerve and diaphragm ultrasonography documented reduced right hemi-diaphragm excursion. Six months later and after optimization of CODP treatment, his respiratory function had improved and both phrenic nerve conduction and diaphragm excursion were completely restored. We hypothesize that chronic cough and nerve stretching in the context of CODP, together with severe weight loss, may have triggered the nerve paralysis in this patient. Our report highlights the need for optimal management of comorbidities such as CODP as well as careful control of weight in HNPP patients to avoid potentially harmful complications. Copyright © 2016 Elsevier B.V. All rights reserved.

Dynamic Postural-Stability Deficits After Cryotherapy to the Ankle Joint.

PubMed

Fullam, Karl; Caulfield, Brian; Coughlan, Garrett F; McGroarty, Mark; Delahunt, Eamonn

2015-09-01

Decreased postural stability is a primary risk factor for lower limb musculoskeletal injuries. During athletic competitions, cryotherapy may be applied during short breaks in play or during half-time; however, its effects on postural stability remain unclear. To investigate the acute effects of a 15-minute ankle-joint cryotherapy application on dynamic postural stability. Controlled laboratory study. University biomechanics laboratory. A total of 29 elite-level collegiate male field-sport athletes (age = 20.8 ± 1.12 years, height = 1.80 ± 0.06 m, mass = 81.89 ± 8.59 kg) participated. Participants were tested on the anterior (ANT), posterolateral (PL), and posteromedial (PM) reach directions of the Star Excursion Balance Test before and after a 15-minute ankle-joint cryotherapy application. Normalized reach distances; sagittal-plane kinematics of the hip, knee, and ankle joints; and associated mean velocity of the center-of-pressure path during performance of the ANT, PL, and PM reach directions of the Star Excursion Balance Test. We observed a decrease in reach-distance scores for the ANT, PL, and PM reach directions from precryotherapy to postcryotherapy (P < .05). No differences were observed in hip-, knee-, or ankle-joint sagittal-plane kinematics (P > .05). We noted a decrease in mean velocity of the center-of-pressure path from precryotherapy to postcryotherapy (P < .05) in all reach directions. Dynamic postural stability was adversely affected immediately after cryotherapy to the ankle joint.

The effect of spinal position on sciatic nerve excursion during seated neural mobilisation exercises: an in vivo study using ultrasound imaging

PubMed Central

Ellis, Richard; Osborne, Samantha; Whitfield, Janessa; Parmar, Priya; Hing, Wayne

2017-01-01

Objectives Research has established that the amount of inherent tension a peripheral nerve tract is exposed to influences nerve excursion and joint range of movement (ROM). The effect that spinal posture has on sciatic nerve excursion during neural mobilisation exercises has yet to be determined. The purpose of this research was to examine the influence of different sitting positions (slump-sitting versus upright-sitting) on the amount of longitudinal sciatic nerve movement during different neural mobilisation exercises commonly used in clinical practice. Methods High-resolution ultrasound imaging followed by frame-by-frame cross-correlation analysis was used to assess sciatic nerve excursion. Thirty-four healthy participants each performed three different neural mobilisation exercises in slump-sitting and upright-sitting. Means comparisons were used to examine the influence of sitting position on sciatic nerve excursion for the three mobilisation exercises. Linear regression analysis was used to determine whether any of the demographic data represented predictive variables for longitudinal sciatic nerve excursion. Results There was no significant difference in sciatic nerve excursion (across all neural mobilisation exercises) observed between upright-sitting and slump-sitting positions (P = 0.26). Although greater body mass index, greater knee ROM and younger age were associated with higher levels of sciatic nerve excursion, this model of variables offered weak predictability (R2 = 0.22). Discussion Following this study, there is no evidence that, in healthy people, longitudinal sciatic nerve excursion differs significantly with regards to the spinal posture (slump-sitting and upright-sitting). Furthermore, although some demographic variables are weak predictors, the high variance suggests that there are other unknown variables that may predict sciatic nerve excursion. It can be inferred from this research that clinicians can individualise the design of seated neural mobilisation exercises, using different seated positions, based upon patient comfort and minimisation of neural mechanosensitivity with the knowledge that sciatic nerve excursion will not be significantly influenced. PMID:28559669

Improving balance skills in patients who had stroke through virtual reality treadmill training.

PubMed

Yang, Saiwei; Hwang, Wei-Hsung; Tsai, Yi-Ching; Liu, Fu-Kang; Hsieh, Lin-Fen; Chern, Jen-Suh

2011-12-01

The aim of this study was to evaluate the effects of virtual reality (VR) treadmill training on the balance skills of patients who have had a stroke. A total of 14 patients with strokes were recruited and randomly assigned to receive VR treadmill or traditional treadmill training. The outcome measures that were included for the study were center of pressure (COP) sway excursion, COP maximum sway in anterior-posterior direction, COP maximum sway in medial-lateral direction, COP sway area, bilateral limb-loading symmetric index, the sway excursion values for the paretic foot (sway excursion/P), paretic limb stance time (stance time/P), number of steps of the paretic limb (number of steps/P), and contact area of the paretic foot (contact A/P) during quiet stance, sit-to-stand transfer, and level walking. There were no significant improvements in COP-related measures and symmetric index during the quiet stance, either in the VR treadmill or traditional treadmill training group (P > 0.05). However, the difference between groups after training in COP maximum sway in medial-lateral direction during the quiet stance was significant (P = 0.038). Traditional treadmill training failed to improve sit-to-stand performance, whereas VR treadmill training improved symmetric index (P = 0.028) and sway excursion (P = 0.046) significantly during sit-to-stand transfer. The changes of symmetric index between groups were markedly different (P = 0.045). Finally, both groups improved significantly in stance time/P, but only VR treadmill training increased contact A/P (P = 0.034) after training during level walking. The difference between groups during level walking was not significant. Neither traditional treadmill nor VR treadmill training had any effect on balance skill during quiet stance, but VR treadmill training improved balance skill in the medial-lateral direction better than traditional training did. VR treadmill training also improved balance skill during sit-to-stand transfers and the involvement of paretic limb in level walking more than the traditional one did.

Left ventricular long-axis function in treated haemochromatosis.

PubMed

Davidsen, Einar Skulstad; Hervig, Tor; Omvik, Per; Gerdts, Eva

2009-03-01

We recently demonstrated reduced exercise capacity in treated genetic haemochromatosis, in spite of normal radial left ventricular (LV) systolic function assessed by 2-dimensional echocardiography at rest. It remains unknown if haemochromatosis-related impairment of LV long-axis function can be demonstrated also at rest. LV long-axis function was assessed by echocardiography including spectral tissue Doppler of systolic (S') and early (E') diastolic velocities in 105 treated haemochromatosis patients and 50 controls. Patients had higher body mass index, systolic atrioventricular excursion, and smaller LV end-systolic diameter (all P < 0.05). Other conventional echocardiographic variables did not differ. S' was normal in both groups, though significantly higher among the patients (11.1 vs. 9.9 cm/s, P < 0.001). In multiple regression analysis, higher S' was associated with having haemochromatosis, independently of significant contributions from higher atrioventricular excursion and LV length, and lower body mass index and E/E'-ratio (multiple R(2) = 0.44, P < 0.001). E' did not differ between patients and controls. However, in multivariate analysis lower E' was associated with having haemochromatosis independently of significant contributions from higher age and diastolic blood pressure, and lower transmitral E and end-diastolic LV length (multiple R(2) = 0.57, P < 0.001). The long-axis function in the haemochromatosis group was normal. Still haemochromatosis, even in this group of patients treated with regular phlebotomy, influenced both systolic and early diastolic long-axis function, and was associated with higher atrioventricular excursion and S', and with lower E'.

Influence of magnetic pressure on stellar structure: A Mechanism for solar variability

NASA Technical Reports Server (NTRS)

Schatten, K. H.; Endal, A. S.

1980-01-01

A physical mechanism is proposed that couples the Sun's dynamo magnetic field to its gravitational potential energy. The mechanism involves the isotropic field pressure resulting in a lifting force on the convective envelope, thereby raising its potential energy. Decay of the field due to solar activity allows the envelop to subside and releases this energy, which can augment the otherwise steady solar luminosity. Equations are developed and applied to the Sun for several field configurations. The best estimate model suggests that uniform luminosity variations as large as 0.02% for half a sunspot cycle may occur. Brief temporal variations or the rotation of spatial structures could allow larger excursions in the energy released.

Stratified charge rotary aircraft engine technology enablement program

NASA Technical Reports Server (NTRS)

Badgley, P. R.; Irion, C. E.; Myers, D. M.

1985-01-01

The multifuel stratified charge rotary engine is discussed. A single rotor, 0.7L/40 cu in displacement, research rig engine was tested. The research rig engine was designed for operation at high speeds and pressures, combustion chamber peak pressure providing margin for speed and load excursions above the design requirement for a high is advanced aircraft engine. It is indicated that the single rotor research rig engine is capable of meeting the established design requirements of 120 kW, 8,000 RPM, 1,379 KPA BMEP. The research rig engine, when fully developed, will be a valuable tool for investigating, advanced and highly advanced technology components, and provide an understanding of the stratified charge rotary engine combustion process.

Denali Geographic 2012 : A University led scientific field experience for High School students at the Alaska Summer Research Academy

NASA Astrophysics Data System (ADS)

Shipman, J. S.; Webley, P. W.; Burke, S.; Chebul, E.; Dempsey, A.; Hastings, H.; Terry, R.; Drake, J.

2012-12-01

The Alaska Summer Research Academy (ASRA) annually provides the opportunity for ~150 exceptional high school students to engage in scientific exploration at the university level. In July 2012, University of Alaska Fairbanks instructors led a two-week long ASRA module, called 'Denali Geographic', where eight student participants from across the USA and Canada learned how to observe changes in the natural world and design their own experiments for a field expedition to Denali National Park and Preserve, with assistance from the National Park Service. Each student designed an experiment/observational project prior to the expedition to investigate changes across the expanse of the park. Projects included wildlife documentation; scat and track observations; soil ph and moisture with elevation and vegetation changes; wildflowers species distribution; waterborne insect populations; atmospheric pressure and temperature variations; construction of sustainable buildings to minimize human impact on the park; and park geology comparisons between outcrop and distal stream deposits. The students learned how to design experiments, purchase supplies needed to conduct the work, and select good locations in which to sample in the park. Students used equipment such as GPS to mark field locations; a range finder to determine distance from wildlife; a hygrometer for temperature and pressure; nets and sorting equipments to analyze insects; and the preparation of Plaster of Paris for creating casts of animal tracks. All observations were documented in their field notebooks and blog entries made to share their experiences. Day excursions as part of the module included Poker Flats Research Range, where students learned about the use of unmanned aerial vehicles in scientific exploration; Alaska Volcano Observatory, where students learned about volcanic hazards in Alaska and the North Pacific; Chena Hot Springs and the Ice Museum, where students learned about thermal imaging using a Forward Looking Infrared Radiometer; and Pioneer Park to learn how to pan for gold. After the completion of the expedition, students had to then synthesize each of their research projects and create a collaborative presentation of their findings. On the final day of the camp, students delivered a presentation to 150 of their peers and instructors in the other ASRA modules. Presented here are details of the field camp and experiences gained by the students. The camp and two-week long module showed students how to pursue their own curiosities about the natural world. By encouraging students to take an idea and develop it into a research topic, we engaged them in the scientific method and illustrated possibilities for future avenues of academic study.

Purge gas protected transportable pressurized fuel cell modules and their operation in a power plant

DOEpatents

Zafred, P.R.; Dederer, J.T.; Gillett, J.E.; Basel, R.A.; Antenucci, A.B.

1996-11-12

A fuel cell generator apparatus and method of its operation involves: passing pressurized oxidant gas and pressurized fuel gas into modules containing fuel cells, where the modules are each enclosed by a module housing surrounded by an axially elongated pressure vessel, and where there is a purge gas volume between the module housing and pressure vessel; passing pressurized purge gas through the purge gas volume to dilute any unreacted fuel gas from the modules; and passing exhaust gas and circulated purge gas and any unreacted fuel gas out of the pressure vessel; where the fuel cell generator apparatus is transportable when the pressure vessel is horizontally disposed, providing a low center of gravity. 11 figs.

Concept of Operations for a Prospective "Proving Ground" in the Lunar Vicinity

NASA Technical Reports Server (NTRS)

Love, Stanley G.; Hill, James J.; Goodliff, Kandyce

2016-01-01

NASA is studying conceptual architectures for a "Proving Ground" near the Moon or in high lunar orbit to conduct human space exploration missions that bridge the gap between today's operations with the International Space Station (ISS) and future human exploration of Mars beginning in the 2030s. This paper describes the framework of a concept of operations ("Conops") for candidate activities in the Proving Ground. The Conops discusses broad goals that the Proving Ground might address, such as participation from commercial entities, support for human landings on the Moon, use of mature technologies, and growth of capability through a steady cadence of increasingly ambitious piloted missions. Additional Proving Ground objectives are outlined in a companion paper. Key elements in the Conops include the Orion spacecraft (with mission kits for docking and other specialized operations) and the Space Launch System (SLS) heavy-lift rocket. Potential additions include a new space suit, commercial launch vehicles and logistics carriers, Solar Electric Propulsion (SEP) stages to move elements between different orbits and eventually take them on excursions to deep space, a core module with multiple docking ports, a habitation block, and robotic and piloted lunar landers. The landers might include reusable ascent modules which could remain docked to in-space elements between lunar sorties. A module providing advanced regenerative life support functions could launch to the ISS, and later move to the Proving Ground. The architecture will include infrastructure for launch preparation, communication, mission control, and range safety. The Conops describes notional missions chosen to guide the design of the architecture and its elements. One such mission might be the delivery of a approximately 10-t Transit Habitat element, comanifested with Orion on a Block 1B SLS launcher, to the Proving Ground. In another mission, the architecture might participate in direct human exploration of an asteroidal boulder brought to high lunar orbit by the Asteroid Redirect Mission. The Proving Ground stack could serve as a staging point and tele-operation center for robotic and piloted Moon landings. With the addition of a SEP stage, the architecture could support months-long excursions within and beyond the Earth's sphere of influence, possibly culminating in a year-long mission to land humans on a near-Earth asteroid. In the last case, after returning to near-lunar space, two of the asteroid explorers could join two crewmembers freshly arrived from Earth for a Moon landing, helping to quantify the risk of landing deconditioned crews on Mars. In a conceptual mission particularly stressing to system design, Proving Ground elements could transit to Mars orbit. Other possible design-driving operations include relocation of the stack with no crew on board, the unpiloted journey of the advanced life support module from ISS to the lunar vicinity, excursions to other destinations in near-Earth space, and additional support for Mars exploration in conjunction with the Evolvable Mars Campaign. The Proving Ground Conops concludes with a discussion of aborts and contingency operations

The effects of texting on driving performance in a driving simulator: the influence of driver age.

PubMed

Rumschlag, Gordon; Palumbo, Theresa; Martin, Amber; Head, Doreen; George, Rajiv; Commissaris, Randall L

2015-01-01

Distracted driving is a significant contributor to motor vehicle accidents and fatalities, and texting is a particularly significant form of driver distraction that continues to be on the rise. The present study examined the influence of driver age (18-59 years old) and other factors on the disruptive effects of texting on simulated driving behavior. While 'driving' the simulator, subjects were engaged in a series of brief text conversations with a member of the research team. The primary dependent variable was the occurrence of Lane Excursions (defined as any time the center of the vehicle moved outside the directed driving lane, e.g., into the lane for oncoming traffic or onto the shoulder of the road), measured as (1) the percent of subjects that exhibited Lane Excursions, (2) the number of Lane Excursions occurring and (3) the percent of the texting time in Lane Excursions. Multiple Regression analyses were used to assess the influence of several factors on driving performance while texting, including text task duration, texting skill level (subject-reported), texting history (#texts/week), driver gender and driver age. Lane Excursions were not observed in the absence of texting, but 66% of subjects overall exhibited Lane Excursions while texting. Multiple Regression analysis for all subjects (N=50) revealed that text task duration was significantly correlated with the number of Lane Excursions, and texting skill level and driver age were significantly correlated with the percent of subjects exhibiting Lane Excursions. Driver gender was not significantly correlated with Lane Excursions during texting. Multiple Regression analysis of only highly skilled texters (N=27) revealed that driver age was significantly correlated with the number of Lane Excursions, the percent of subjects exhibiting Lane Excursions and the percent of texting time in Lane Excursions. In contrast, Multiple Regression analysis of those drivers who self-identified as not highly skilled texters (N=23) revealed that text task duration was significantly correlated with the number of Lane Excursions. The present studies confirm past reports that texting impairs driving simulator performance. Moreover, the present study demonstrates that for highly skilled texters, the effects of texting on driving are actually worse for older drivers. Given the increasing frequency of texting while driving within virtually all age groups, these data suggest that 'no texting while driving' education and public service messages need to be continued, and they should be expanded to target older drivers as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

Beta-erythropoietin effects on ventricular remodeling, left and right systolic function, pulmonary pressure, and hospitalizations in patients affected with heart failure and anemia.

PubMed

Palazzuoli, Alberto; Silverberg, Donald S; Calabrò, Anna; Spinelli, Tommaso; Quatrini, Ilaria; Campagna, Maria S; Franci, Beatrice; Nuti, Ranuccio

2009-06-01

Anemia in heart failure is related to advanced New York Heart Association classes, severe systolic dysfunction, and reduced exercise tolerance. Although anemia is frequently found in congestive heart failure (CHF), little is known about the effect of its' correction with erythropoietin (EPO) on cardiac structure and function. The present study examines, in patients with advanced CHF and anemia, the effects of beta-EPO on left ventricular volumes, left ventricular ejection fraction (LVEF), left and right longitudinal function mitral anular plane systolic excursion (MAPSE), tricuspid anular plane excursion (TAPSE), and pulmonary artery pressures in 58 patients during 1-year follow-up in a double-blind controlled study of correction of anemia with subcutaneous beta-EPO. Echocardiographic evaluation, B-Type natriuretic peptide (BNP) levels, and hematological parameters are reported at 4 and 12 months. The patients in group A after 4 months of follow-up period demonstrated an increase in LVEF and MAPSE (P < 0.05 and P < 0.01, respectively) with left ventricular systolic volume reduction (P < 0.02) with respect to baseline and controls. After 12 months, results regarding left ventricular systolic volume LVEF and MAPSE persisted (P < 0.001). In addition, TAPSE increased and pulmonary artery pressures fell significantly in group A (P < 0.01). All these changes occurred together with a significant BNP reduction and significant hemoglobin increase in the treated group. Therefore, we revealed a reduced hospitalization rate in treated patients with respect to the controls (25% in treated vs. 54% in controls). In patients with anemia and CHF, correction of anemia with beta-EPO and oral iron over 1 year leads to an improvement in left and right ventricular systolic function by reducing cardiac remodeling, BNP levels, and hospitalization rate.

Proceedings of the International Cryocoolers Conference (4th) Held in Easton, Maryland on 25-26 September 1986

DTIC Science & Technology

1987-10-30

simple relationship for the required refrigerant mass flow rate, m, for a given cooling load, q1l m = where Ah is the enthalpy difference between the cool...compressor concepts were tested to determine their performance. No measurable difference in performance was found and the first, more compact, concept was...resulting change in orifice size adjusts the mass flow rate through the valve. By reducing excursions in the pressure difference across the J-T valve, the

Purge gas protected transportable pressurized fuel cell modules and their operation in a power plant

DOEpatents

Zafred, Paolo R.; Dederer, Jeffrey T.; Gillett, James E.; Basel, Richard A.; Antenucci, Annette B.

1996-01-01

A fuel cell generator apparatus and method of its operation involves: passing pressurized oxidant gas, (O) and pressurized fuel gas, (F), into fuel cell modules, (10 and 12), containing fuel cells, where the modules are each enclosed by a module housing (18), surrounded by an axially elongated pressure vessel (64), where there is a purge gas volume, (62), between the module housing and pressure vessel; passing pressurized purge gas, (P), through the purge gas volume, (62), to dilute any unreacted fuel gas from the modules; and passing exhaust gas, (82), and circulated purge gas and any unreacted fuel gas out of the pressure vessel; where the fuel cell generator apparatus is transpatable when the pressure vessel (64) is horizontally disposed, providing a low center of gravity.

The Habitat Demonstration Unit System Integration

NASA Technical Reports Server (NTRS)

Gill, Tracy R.; Kennedy, Kriss J.; Tri, Terry O.; Howe, Alan S.

2010-01-01

The Lunar Surface System Habitat Demonstration Unit (HDU) will require a project team to integrate a variety of contributions from National Aeronautics and Space Administration (NASA) centers and potential outside collaborators and poses a challenge in integrating these disparate efforts into a cohesive architecture. To accomplish the development of the first version of the HDU, the Pressurized Excursion Module (PEM), from conception in June 2009 to rollout for operations in July 2010, the HDU project team is using several strategies to mitigate risks and bring the separate efforts together. First, a set of design standards is being developed to define the interfaces between the various systems of PEM and to the payloads, such as the Geology Laboratory, that those systems will support. Scheduled activities such as early fit-checks and the utilization of a habitat avionics test bed prior to equipment installation into HDU PEM are planned to facilitate the integration process. A coordinated effort to establish simplified Computer Aided Design (CAD) standards and the utilization of a modeling and simulation systems will aid in design and integration concept development. Finally, decision processes on the shell development including the assembly sequence and the transportation have been fleshed out early on HDU design to maximize the efficiency of both integration and field operations.

Autonomous excursions using tablets and smartphones

NASA Astrophysics Data System (ADS)

Marra, Wouter; Groothengel, Marin; van de Grint, Liesbeth; Karssenberg, Derek; Stouthamer, Esther

2017-04-01

Excursions and fieldworks are valuable components for geosciences education. However, field activities can be time consuming for teachers and pose a logistical challenge to fit in regular courses. Furthermore, the participation of students diminishes with group size in case of instructor-led outings. We are developing excursions that students can follow autonomously without a teacher present, using instructions, assignments and background information on tablets and smartphones. The goal of this approach is to increase the level of active participation, and to reduce logistical and time table issues. We developed a bike-excursion about the landscape and geology in the vicinity of our University. Such excursion was on the wish-list for several years, but posed a logistical challenge for the group of about 80 students in the available timeslot. In our approach, students had a time-window of two weeks in which they could finish the excursion in groups of 2. 8-Inch tablets with water- and shock-proof cases were available for this excursion. For the excursion we used three apps: 1) IZI-Travel for providing the route, spoken navigation instructions, spoken explanations at stops, location-related images, assignments as text, and multiple-choose questions. 2) PDF-Maps for providing geo-referenced maps. 3) ESRI Collector which the students used to digitize polygons on a map, and to collect geo-referenced photos with explanation. These data were answers to assignments and were later used in a tutorial on campus. The assignments where students had to collect data, and the small group size (pairs) increased the level of active participation. The use of a final tutorial on campus was important for the autonomous excursion, as it gave students the opportunity to discuss their observations and questions with their teacher. The developed teaching materials are available online to use and adapt for others. Parts could be useful for other universities and schools in the vicinity of the excursion location.

Design of a probe for two-dimensional small angle detection

NASA Astrophysics Data System (ADS)

He, Haixia; Wang, Xuanze; Zhong, Yuning; Yang, Liangen; Cao, Hongduan

2008-10-01

A novel two-dimensional small angle probe is introduced, which is based on principle of auto-collimation and utilizes quadrant Si-photoelectric detector (QPD) as detection device. AC modulation, AC magnification and absolute value demodulation are incorporated to restrain the DC excursion caused by background light and noise etc and to improve the sensitivity and stability of angle detection. To ensure that while the laser is shining, the current signal (converted into voltage signal) of QPD also is linear to the AC modulation voltage, this paper adopted AC modulation signal (5400Hz) with a DC offset. AC magnification circuit with reasonable parameters is designed to inhibit DC drift and the impact of industrial frequency noise and to ensure good amplification to signal frequency at the same time. A piezoelectric-driven micro-angle generator is designed to demarcate the angle. The calibration data are input to single chip, and the measurement of angles can be shown in SMC1602A.

49 CFR 38.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 1 2014-10-01 2014-10-01 false Ferries, excursion boats and other vessels. [Reserved] 38.177 Section 38.177 Transportation Office of the Secretary of Transportation AMERICANS WITH....177 Ferries, excursion boats and other vessels. [Reserved] ...

49 CFR 38.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Ferries, excursion boats and other vessels. [Reserved] 38.177 Section 38.177 Transportation Office of the Secretary of Transportation AMERICANS WITH....177 Ferries, excursion boats and other vessels. [Reserved] ...

49 CFR 38.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 1 2011-10-01 2011-10-01 false Ferries, excursion boats and other vessels. [Reserved] 38.177 Section 38.177 Transportation Office of the Secretary of Transportation AMERICANS WITH....177 Ferries, excursion boats and other vessels. [Reserved] ...

49 CFR 38.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 1 2013-10-01 2013-10-01 false Ferries, excursion boats and other vessels. [Reserved] 38.177 Section 38.177 Transportation Office of the Secretary of Transportation AMERICANS WITH....177 Ferries, excursion boats and other vessels. [Reserved] ...

49 CFR 38.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 1 2012-10-01 2012-10-01 false Ferries, excursion boats and other vessels. [Reserved] 38.177 Section 38.177 Transportation Office of the Secretary of Transportation AMERICANS WITH....177 Ferries, excursion boats and other vessels. [Reserved] ...

Comparison of longitudinal excursion of a nerve-phantom model using quantitative ultrasound imaging and motion analysis system methods: A convergent validity study.

PubMed

Paquette, Philippe; El Khamlichi, Youssef; Lamontagne, Martin; Higgins, Johanne; Gagnon, Dany H

2017-08-01

Quantitative ultrasound imaging is gaining popularity in research and clinical settings to measure the neuromechanical properties of the peripheral nerves such as their capability to glide in response to body segment movement. Increasing evidence suggests that impaired median nerve longitudinal excursion is associated with carpal tunnel syndrome. To date, psychometric properties of longitudinal nerve excursion measurements using quantitative ultrasound imaging have not been extensively investigated. This study investigates the convergent validity of the longitudinal nerve excursion by comparing measures obtained using quantitative ultrasound imaging with those determined with a motion analysis system. A 38-cm long rigid nerve-phantom model was used to assess the longitudinal excursion in a laboratory environment. The nerve-phantom model, immersed in a 20-cm deep container filled with a gelatin-based solution, was moved 20 times using a linear forward and backward motion. Three light-emitting diodes were used to record nerve-phantom excursion with a motion analysis system, while a 5-cm linear transducer allowed simultaneous recording via ultrasound imaging. Both measurement techniques yielded excellent association ( r  = 0.99) and agreement (mean absolute difference between methods = 0.85 mm; mean relative difference between methods = 7.48 %). Small discrepancies were largely found when larger excursions (i.e. > 10 mm) were performed, revealing slight underestimation of the excursion by the ultrasound imaging analysis software. Quantitative ultrasound imaging is an accurate method to assess the longitudinal excursion of an in vitro nerve-phantom model and appears relevant for future research protocols investigating the neuromechanical properties of the peripheral nerves.

Dynamics of the earth magnetic field in the 10-75 kyr period comprising the Laschamp and Mono Lake excursions: New results from the French Chaîne des Puys in a global perspective

NASA Astrophysics Data System (ADS)

Laj, Carlo; Guillou, Hervé; Kissel, Catherine

2014-02-01

We report here on a new paleomagnetic (directions and intensities) and coupled K/Ar and 40Ar/39Ar analysis of 35 different flows, emplaced in the Chaîne des Puys during the 75 to 10 kyr interval, which contains the Mono Lake and Laschamp excursions. There is a remarkable agreement between the new set of absolute volcanic intensities and published sedimentary (GLOPIS-75) and cosmogenic (10Be and 36Cl) records. The Laschamp and Mono Lake excursions are clearly revealed by a very significant intensity drop at 41.2±1.6 ka and 34.2±1.2 ka respectively. The duration of the Laschamp excursion is ˜1500 yr and about 640 yr when the drop of paleointensity or the directional change are considered respectively. The intensity drop at the Mono Lake is twice as short. In the ˜7 ka interval separating the two excursions, the field intensity recovers to almost non-transitional values. The rate of decrease of the field intensity during these excursions attains 18 nT/yr for the Laschamp and even greater value (33 nT/yr) for the Mono Lake. This figure is, for the Laschamp excursion, similar to the present field intensity decrease in the last two centuries so that one may wonder whether such a high rate of change may be characteristic of an impending geomagnetic event (reversal or excursion). We suggest that the name Auckland excursion should be used for the present-day called Mono Lake.

Condylar motion in children with primary dentition during lateral excursion.

PubMed

Yamasaki, Youichi; Hayasaki, Haruaki; Nishi, Megumi; Nakata, Shiho; Nakata, Minoru

2002-07-01

Normal development of primary and mixed dentition is indispensable for establishing a healthy mandibular function of the permanent dentition. Because condylar movements are crucial for mandibular function, extensive studies have been reported. However, most of these studies have dealt with mandibular functions in adults, and there is less known about children with primary dentition. The purpose of this study was to clarify the condylar movements during lateral excursions in children with primary dentition and compare these movements with those of adults from the viewpoint of functional development. With use of an optoelectronic recording system with six degrees of freedom, the lateral excursions of 24 children and 20 young women, with sound dentition, were recorded at 100 Hz. The results show that the balancing side condyle of the children had a significantly smaller vertical excursion and a significantly larger anteroposterior excursion than that of adults, indicating the shallower and more anteriorly directed movements of the entire mandible during lateral excursions in children with primary dentition.

Evaluating OSHA's ethylene oxide standard: exposure determinants in Massachusetts hospitals.

PubMed

LaMontagne, A D; Kelsey, K T

2001-03-01

This study sought to identify determinants of workplace exposures to ethylene oxide to assess the effect of the Occupational Safety and Health Administration's (OSHA's) 1984 ethylene oxide standard. An in-depth survey of all hospitals in Massachusetts that used ethylene oxide from 1990 through 1992 (96% participation, N = 90) was conducted. Three types of exposure events were modeled with logistic regression: exceeding the 8-hour action level, exceeding the 15-minute excursion limit, and worker exposures during unmeasured accidental releases. Covariates were drawn from data representing an ecologic framework including direct and indirect potential exposure determinants. After adjustment for frequencies of ethylene oxide use and exposure monitoring, a significant inverse relation was observed between exceeding the action level and the use of combined sterilizer-aerators, an engineering control technology developed after the passage of the OSHA standard. Conversely, the use of positive-pressure sterilizers that employ ethylene oxide gas mixtures was strongly related to both exceeding the excursion limit and the occurrence of accidental releases. These findings provide evidence of a positive effect of OSHA's ethylene oxide standard and specific targets for future prevention and control efforts.

Excursions out-of-lane versus standard deviation of lateral position as outcome measure of the on-the-road driving test.

PubMed

Verster, Joris C; Roth, Thomas

2014-07-01

The traditional outcome measure of the Dutch on-the-road driving test is the standard deviation of lateral position (SDLP), the weaving of the car. This paper explores whether excursions out-of-lane are a suitable additional outcome measure to index driving impairment. A literature search was conducted to search for driving tests that used both SDLP and excursions out-of-lane as outcome measures. The analyses were limited to studies examining hypnotic drugs because several of these drugs have been shown to produce next-morning sedation. Standard deviation of lateral position was more sensitive in demonstrating driving impairment. In fact, solely relying on excursions out-of-lane as outcome measure incorrectly classifies approximately half of impaired drives as unimpaired. The frequency of excursions out-of-lane is determined by the mean lateral position within the right traffic lane. Defining driving impairment as having a ΔSDLP > 2.4 cm, half of the impaired driving tests (51.2%, 43/84) failed to produce excursions out-of-lane. Alternatively, 20.9% of driving tests with ΔSDLP < 2.4 cm (27/129) had at least one excursion out-of-lane. Excursions out-of-lane are neither a suitable measure to demonstrate driving impairment nor is this measure sufficiently sensitive to differentiate adequately between differences in magnitude of driving impairment. Copyright © 2014 John Wiley & Sons, Ltd.

Annoyance due to simulated blade-slap noise

NASA Technical Reports Server (NTRS)

Powell, C. A.

1978-01-01

The effects of several characteristics of blade slap noise on annoyance response were studied. These characteristics or parameters were the sound pressure level of the continuous noise used to simulate helicopter broadband noise, the ratio of impulse peak to broadband noise or crest factor, the number of pressure excursions comprising an impulse event, the rise and fall time of the individual impulses, and the repetition frequency of the impulses. Analyses were conducted to determine the correlation between subjective response and various physical measures for the range of parameters studied. A small but significant improvement in the predictive ability of PNL was provided by an A-weighted crest factor correlation. No significant improvement in predictive ability was provided by a rate correction.

Probabilistic risk assessment of the Space Shuttle. Phase 3: A study of the potential of losing the vehicle during nominal operation. Volume 5: Auxiliary shuttle risk analyses

NASA Technical Reports Server (NTRS)

Fragola, Joseph R.; Maggio, Gaspare; Frank, Michael V.; Gerez, Luis; Mcfadden, Richard H.; Collins, Erin P.; Ballesio, Jorge; Appignani, Peter L.; Karns, James J.

1995-01-01

Volume 5 is Appendix C, Auxiliary Shuttle Risk Analyses, and contains the following reports: Probabilistic Risk Assessment of Space Shuttle Phase 1 - Space Shuttle Catastrophic Failure Frequency Final Report; Risk Analysis Applied to the Space Shuttle Main Engine - Demonstration Project for the Main Combustion Chamber Risk Assessment; An Investigation of the Risk Implications of Space Shuttle Solid Rocket Booster Chamber Pressure Excursions; Safety of the Thermal Protection System of the Space Shuttle Orbiter - Quantitative Analysis and Organizational Factors; Space Shuttle Main Propulsion Pressurization System Probabilistic Risk Assessment, Final Report; and Space Shuttle Probabilistic Risk Assessment Proof-of-Concept Study - Auxiliary Power Unit and Hydraulic Power Unit Analysis Report.

Electronically scanned pressure sensor module with in SITU calibration capability

NASA Technical Reports Server (NTRS)

Gross, C. (Inventor)

1978-01-01

This high data rate pressure sensor module helps reduce energy consumption in wind tunnel facilities without loss of measurement accuracy. The sensor module allows for nearly a two order of magnitude increase in data rates over conventional electromechanically scanned pressure sampling techniques. The module consists of 16 solid state pressure sensor chips and signal multiplexing electronics integrally mounted to a four position pressure selector switch. One of the four positions of the pressure selector switch allows the in situ calibration of the 16 pressure sensors; the three other positions allow 48 channels (three sets of 16) pressure inputs to be measured by the sensors. The small size of the sensor module will allow mounting within many wind tunnel models, thus eliminating long tube lengths and their corresponding slow pressure response.

46 CFR 2.01-45 - Excursion permit.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., on Coast Guard Form CG-950, Application for Excursion Permit. If, after inspection, permission is... the application process for excursion permits for inspected passenger vessels are contained in §§ 71.10, 115.204, or 176.204 of this chapter. Details concerning the application process for special...

A new approach of the Star Excursion Balance Test to assess dynamic postural control in people complaining from chronic ankle instability.

PubMed

Pionnier, Raphaël; Découfour, Nicolas; Barbier, Franck; Popineau, Christophe; Simoneau-Buessinger, Emilie

2016-03-01

The purpose of this study was to quantitatively and qualitatively assess dynamic balance with accuracy in individuals with chronic ankle instability (CAI). To this aim, a motion capture system was used while participants performed the Star Excursion Balance Test (SEBT). Reached distances for the 8 points of the star were automatically computed, thereby excluding any dependence to the experimenter. In addition, new relevant variables were also computed, such as absolute time needed to reach each distance, lower limb ranges of motion during unipodal stance, as well as absolute error of pointing. Velocity of the center of pressure and range of variation of ground reaction forces have also been assessed during the unipodal phase of the SEBT thanks to force plates. CAI group exhibited smaller reached distances and greater absolute error of pointing than the control group (p<0.05). Moreover, the ranges of motion of lower limbs joints, the velocity of the center of pressure and the range of variation of the ground reaction forces were all significantly smaller in the CAI group (p<0.05). These reduced quantitative and qualitative performances highlighted a lower dynamic postural control. The limited body movements and accelerations during the unipodal stance in the CAI group could highlight a protective strategy. The present findings could help clinicians to better understand the motor strategies used by CAI patients during dynamic balance and may guide the rehabilitation process. Copyright © 2016 Elsevier B.V. All rights reserved.

46 CFR 115.204 - Permit to carry excursion party.

Code of Federal Regulations, 2010 CFR

2010-10-01

... jacket, fire safety, and manning standards applicable to a vessel in the service for which the excursion... crew required, any additional lifesaving or safety equipment required, the route for which the permit... applicable minimum safety standards when issuing an excursion permit. In particular, a vessel that is being...

46 CFR 115.204 - Permit to carry excursion party.

Code of Federal Regulations, 2012 CFR

2012-10-01

... jacket, fire safety, and manning standards applicable to a vessel in the service for which the excursion... crew required, any additional lifesaving or safety equipment required, the route for which the permit... applicable minimum safety standards when issuing an excursion permit. In particular, a vessel that is being...

46 CFR 115.204 - Permit to carry excursion party.

Code of Federal Regulations, 2011 CFR

2011-10-01

... jacket, fire safety, and manning standards applicable to a vessel in the service for which the excursion... crew required, any additional lifesaving or safety equipment required, the route for which the permit... applicable minimum safety standards when issuing an excursion permit. In particular, a vessel that is being...

40 CFR 63.1438 - Parameter monitoring levels and excursions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... required to submit Periodic Reports semiannually or quarterly. The first semiannual period is the 6-month... excursions. (5) For the fifth semiannual period—two excused excursions. (6) For the sixth and all subsequent... during the entire test period. The monitoring level(s) shall be those established during from the...

40 CFR 63.1438 - Parameter monitoring levels and excursions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... required to submit Periodic Reports semiannually or quarterly. The first semiannual period is the 6-month... excursions. (5) For the fifth semiannual period—two excused excursions. (6) For the sixth and all subsequent... during the entire test period. The monitoring level(s) shall be those established during from the...

40 CFR 63.1438 - Parameter monitoring levels and excursions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... required to submit Periodic Reports semiannually or quarterly. The first semiannual period is the 6-month... excursions. (5) For the fifth semiannual period—two excused excursions. (6) For the sixth and all subsequent... during the entire test period. The monitoring level(s) shall be those established during from the...

40 CFR 63.1438 - Parameter monitoring levels and excursions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... required to submit Periodic Reports semiannually or quarterly. The first semiannual period is the 6-month... excursions. (5) For the fifth semiannual period—two excused excursions. (6) For the sixth and all subsequent... during the entire test period. The monitoring level(s) shall be those established during from the...

36 CFR 1192.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Ferries, excursion boats and other vessels. [Reserved] 1192.177 Section 1192.177 Parks, Forests, and Public Property ARCHITECTURAL... GUIDELINES FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.177 Ferries, excursion boats and...

36 CFR 1192.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Ferries, excursion boats and other vessels. [Reserved] 1192.177 Section 1192.177 Parks, Forests, and Public Property ARCHITECTURAL... GUIDELINES FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.177 Ferries, excursion boats and...

36 CFR 1192.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Ferries, excursion boats and other vessels. [Reserved] 1192.177 Section 1192.177 Parks, Forests, and Public Property ARCHITECTURAL... GUIDELINES FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.177 Ferries, excursion boats and...

36 CFR 1192.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Ferries, excursion boats and other vessels. [Reserved] 1192.177 Section 1192.177 Parks, Forests, and Public Property ARCHITECTURAL... GUIDELINES FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.177 Ferries, excursion boats and...

Free gracilis transfer for smile in children: the Massachusetts Eye and Ear Infirmary Experience in excursion and quality-of-life changes.

PubMed

Hadlock, Tessa A; Malo, Juan S; Cheney, Mack L; Henstrom, Douglas K

2011-01-01

Free muscle transfer for facial reanimation has become the standard of care in recent decades and is now the cornerstone intervention for dynamic smile reanimation. We sought to quantify smile excursion and quality-of-life (QOL) changes in our pediatric free gracilis recipients following reanimation. We quantified gracilis muscle excursion in 17 pediatric patients undergoing 19 consecutive pediatric free gracilis transplantation operations, using our validated SMILE program, as an objective measure of functional outcome. These were compared against excursion measured the same way in a cohort of 17 adults with 19 free gracilis operations. In addition, we prospectively evaluated QOL outcomes in these children using the Facial Clinimetric Evaluation (FaCE) instrument. The mean gracilis excursion in our pediatric free gracilis recipients was 8.8 mm ± 5.0 mm, which matched adult results, but with fewer complete failures of less than 2-mm excursion, with 2 (11%) and 4 (21%), respectively. Quality-of-life measures indicated statistically significant improvements following dynamic smile reanimation (P = .01). Dynamic facial reanimation using free gracilis transfer in children has an acceptable success rate, yields improved commissure excursion, and improves QOL in the pediatric population. It should be considered first-line therapy for children with lack of a meaningful smile secondary to facial paralysis.

The Blake geomagnetic excursion recorded in a radiometrically dated speleothem

NASA Astrophysics Data System (ADS)

Osete, María-Luisa; Martín-Chivelet, Javier; Rossi, Carlos; Edwards, R. Lawrence; Egli, Ramon; Muñoz-García, M. Belén; Wang, Xianfeng; Pavón-Carrasco, F. Javier; Heller, Friedrich

2012-11-01

One of the most important developments in geomagnetism has been the recognition of polarity excursions of the Earth's magnetic field. Accurate timing of the excursions is a key point for understanding the geodynamo process and for magnetostratigraphic correlation. One of the best-known excursions is the Blake geomagnetic episode, which occurred during marine isotope stage MIS 5, but its morphology and age remain controversial. Here we show, for the first time, the Blake excursion recorded in a stalagmite which was dated using the uranium-series disequilibrium techniques. The characteristic remanent magnetisation is carried by fine-grained magnetite. The event is documented by two reversed intervals (B1 and B2). The age of the event is estimated to be between 116.5±0.7 kyr BP and 112.0±1.9 kyr BP, slightly younger (∼3-4 kyr) than recent estimations from sedimentary records dated by astronomical tuning. Low values of relative palaeointensity during the Blake episode are estimated, but a relative maximum in the palaeofield intensity coeval with the complete reversal during the B2 interval was observed. Duration of the Blake geomagnetic excursion is 4.5 kyr, two times lower than single excursions and slightly higher than the estimated diffusion time for the inner core (∼3 kyr).

An Evaluation of the British Columbia Asthma Monitoring System (BCAMS) and PM2.5 Exposure Metrics during the 2014 Forest Fire Season

PubMed Central

McLean, Kathleen E.; Yao, Jiayun; Henderson, Sarah B.

2015-01-01

The British Columbia Asthma Monitoring System (BCAMS) tracks forest fire smoke exposure and asthma-related health outcomes, identifying excursions beyond expected daily counts. Weekly reports during the wildfire season support public health and emergency management decision-making. We evaluated BCAMS by identifying excursions for asthma-related physician visits and dispensations of the reliever medication salbutamol sulfate and examining their corresponding smoke exposures. A disease outbreak detection algorithm identified excursions from 1 July to 31 August 2014. Measured, modeled, and forecasted concentrations of fine particulate matter (PM2.5) were used to assess exposure. We assigned PM2.5 levels to excursions by choosing the highest value within a seven day window centred on the excursion day. Smoky days were defined as those with PM2.5 levels ≥ 25 µg/m3. Most excursions (57%–71%) were assigned measured or modeled PM2.5 concentrations of 10 µg/m3 or higher. Of the smoky days, 55.8% and 69.8% were associated with at least one excursion for physician visits and salbutamol dispensations, respectively. BCAMS alerted most often when measures of smoke exposure were relatively high. Better performance might be realized by combining asthma-related outcome metrics in a bivariate model. PMID:26075727

Atmospheric Carbon Dioxide and its Relation to Carbon Cycle Perturbations During Ocean Anoxic Event 1d: A High Resolution Record From Dispersed Plant Cuticle

NASA Astrophysics Data System (ADS)

Richey, J. D.; Upchurch, G. R.; Joeckel, R.; Smith, J. J.; Ludvigson, G. A.; Lomax, B. H.

2013-12-01

Past geological greenhouse intervals are associated with Ocean Anoxic Events (OAEs), which result from an increase in marine primary productivity and/or an increase in the preservation of organic matter. The end point is widespread black shale deposition combined with a long-term atmospheric positive δ13C excursion and an increase in the burial of 12C. Some OAEs show a negative δ13C excursion preceding the positive excursion, indicating a perturbation in the global carbon cycle prior to the initiation of these events. The Rose Creek (RCP) locality, southeastern Nebraska, is the only known terrestrial section that preserves OAE1d (Cretaceous, Albian-Cenomanian Boundary) and has abundant charcoal and plant cuticle. These features allow for a combined carbon isotope and stomatal index (SI) analysis to determine both changes in the cycling between carbon pools (C isotope analysis) and changes in paleo-CO2 via changes in SI. Preliminary (and ongoing) SI data analysis using dispersed cuticle of Pandemophyllum kvacekii (an extinct Laurel) collected at 30 cm intervals indicate changes in SI consistent with changes in CO2. Fitting our samples to a published RCP δ13C profile, pre-excursion CO2 concentrations are high. CO2 decreases to lower concentrations in the basal 1.2 m of the RCP section, where δ13Cbulk shows a negative excursion and δ13Ccharcoal remains at pre-excursion values. CO2 concentrations become higher toward the top of the negative δ13C excursion, where δ13Cbulk and δ13Ccharcoal are at their most negative values, and drop as the negative carbon excursion terminates. Using published transfer functions, we estimate that pre-excursion CO2 concentrations were a maximum of 900 ppm. In the basal 1.2 m of RCP, CO2 drops to a maximum of 480 ppm, and rises to a maximum of 710 ppm near the top of the negative excursion. As δ13C values rise towards pre-excursion values, CO2 declines to a maximum of 400 ppm. The trend in SI is comparable to the trend in δ13Ccharcoal and follows recognized patterns, while SI shows partial divergence from δ13Cbulk. These data, while preliminary, highlight the importance of considering isotope substrate when investigating carbon cycle perturbations.

HDU Deep Space Habitat (DSH) Overview

NASA Technical Reports Server (NTRS)

Kennedy, Kriss J.

2011-01-01

This paper gives an overview of the National Aeronautics and Space Administration (NASA) led multi-center Habitat Demonstration Unit (HDU) project Deep Space Habitat (DSH) analog that will be field-tested during the 2011 Desert Research and Technologies Studies (D-RATS) field tests. The HDU project is a technology pull project that integrates technologies and innovations from multiple NASA centers. This project will repurpose the HDU Pressurized Excursion Module (PEM) that was field tested in the 2010 D-RATS, adding habitation functionality to the prototype unit. The 2010 configuration of the HDU-PEM consisted of a lunar surface laboratory module that was used to bring over 20 habitation-related technologies together in a single platform that could be tested as an advanced habitation analog in the context of mission architectures and surface operations. The 2011 HDU-DSH configuration will build upon the PEM work, and emphasize validity of crew operations (habitation and living, etc), EVA operations, mission operations, logistics operations, and science operations that might be required in a deep space context for Near Earth Object (NEO) exploration mission architectures. The HDU project consists of a multi-center team brought together in a skunkworks approach to quickly build and validate hardware in analog environments. The HDU project is part of the strategic plan from the Exploration Systems Mission Directorate (ESMD) Directorate Integration Office (DIO) and the Exploration Mission Systems Office (EMSO) to test destination elements in analog environments. The 2011 analog field test will include Multi Mission Space Exploration Vehicles (MMSEV) and the DSH among other demonstration elements to be brought together in a mission architecture context. This paper will describe overall objectives, various habitat configurations, strategic plan, and technology integration as it pertains to the 2011 field tests.

46 CFR 72.25-15 - Passenger accommodations for excursion boats, ferryboats, and passenger barges.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Passenger accommodations for excursion boats, ferryboats, and passenger barges. 72.25-15 Section 72.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... accommodations for excursion boats, ferryboats, and passenger barges. (a) Except as specifically excluded by this...

36 CFR § 1192.177 - Ferries, excursion boats and other vessels. [Reserved

Code of Federal Regulations, 2013 CFR

2013-07-01

... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Ferries, excursion boats and other vessels. [Reserved] § 1192.177 Section § 1192.177 Parks, Forests, and Public Property... GUIDELINES FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.177 Ferries, excursion boats and...

46 CFR 72.25-15 - Passenger accommodations for excursion boats, ferryboats, and passenger barges.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Passenger accommodations for excursion boats, ferryboats, and passenger barges. 72.25-15 Section 72.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... accommodations for excursion boats, ferryboats, and passenger barges. (a) Except as specifically excluded by this...

46 CFR 72.25-15 - Passenger accommodations for excursion boats, ferryboats, and passenger barges.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Passenger accommodations for excursion boats, ferryboats, and passenger barges. 72.25-15 Section 72.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... accommodations for excursion boats, ferryboats, and passenger barges. (a) Except as specifically excluded by this...

46 CFR 72.25-15 - Passenger accommodations for excursion boats, ferryboats, and passenger barges.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Passenger accommodations for excursion boats, ferryboats, and passenger barges. 72.25-15 Section 72.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... accommodations for excursion boats, ferryboats, and passenger barges. (a) Except as specifically excluded by this...

46 CFR 72.25-15 - Passenger accommodations for excursion boats, ferryboats, and passenger barges.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Passenger accommodations for excursion boats, ferryboats, and passenger barges. 72.25-15 Section 72.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... accommodations for excursion boats, ferryboats, and passenger barges. (a) Except as specifically excluded by this...

Cruising through Research: Library Skills for Young Adults.

ERIC Educational Resources Information Center

Volkman, John D.

This book presents an approach for school librarians to use to introduce basic research tools to students in grades 7-12. Twelve "Excursions" (i.e., library research projects) are described. Excursions 1 and 2 provide an introduction to reference books, and Excursions 3 and 4 explore note-taking and basic organization of research papers. The…

Recommendation of Sensors for Vehicle Transmission Diagnostics

DTIC Science & Technology

2012-05-01

and a pressure switch module form the Control value module. A thermistor is contained within the pressure switch module in order to monitor the sump...fluid temperature. Sensor information is provided to the TCM through various sensors such as throttle position, speed sensor, pressure switch module

Sedimentary and Volcanic Records of the Laschamp and Mono Lake Excursions from Australia and New Zealand

NASA Astrophysics Data System (ADS)

Ingham, E. M.; Roberts, A. P.; Turner, G. M.; Heslop, D.; Ronge, T.; Conway, C.; Leonard, G.; Townsend, D.; Tiedemann, R.; Lamy, F.; Calvert, A. T.

2014-12-01

Geomagnetic excursions are short-lived deviations of the geomagnetic field from the normal range of secular variation. Despite significant advances in geomagnetic excursion research over the past 20 years, fundamental questions remain concerning the typical duration and global morphology of excursional geomagnetic fields. To answer such questions, more high-resolution, chronologically well-constrained excursion records are required, particularly from the Southern Hemisphere. We present preliminary paleomagnetic records of the Laschamp (~41 ka) and Mono Lake (~35 ka) excursions from three marine sediment cores from the Bounty Trough, New Zealand margin, and complementary volcanic records of the Laschamp excursion from lavas of Mt Ruapehu, New Zealand. Relatively high sedimentation rates of 12 - 26 cm/kyr in the Bounty Trough during glacial periods allow identification of excursional field behavior at each of the studied core locations. Each core displays one or two excursional events, with rapid directional swings between stable normal polarity and reversed excursional directions, each associated with coincident relative paleointensity minima. These anomalous paleomagnetic directions are interpreted to represent the Laschamp and Mono Lake excursions, based on a combination of tephrochronology, radiocarbon dating, and cyclostratigraphy (defined from core-scanning X-ray fluorescence and magnetic susceptibility records). Beside these records, we present results from fourteen lava flows, on Mt Ruapehu, for which 40Ar-39Ar dating indicates ages of between 39 and 45 ka. The step heating 40Ar-39Ar experiments produced particularly flat age plateaus, with corresponding 2 s.d. errors mostly approaching 1 kyr. The youngest and oldest flows carry normal polarity magnetization, however six flows, dated between 41 and 43 ka, display transitional field characteristics. Three of these flows display a declination swing of around 180o, which coincides with a previously published result from the Auckland Basalt Field. Together, these data provide rare excursion records from the southern hemisphere, which will provide an improved view of geomagnetic field morphology during these excursions.

A miniature 48-channel pressure sensor module capable of in situ calibration

NASA Technical Reports Server (NTRS)

Gross, C.; Juanarena, D. B.

1977-01-01

A new high data rate pressure sensor module with in situ calibration capability has been developed by the Langley Research Center to help reduce energy consumption in wind-tunnel facilities without loss of measurement accuracy. The sensor module allows for nearly a two order of magnitude increase in data rates over conventional electromechanically scanned pressure sampling techniques. This module consists of 16 solid state pressure sensor chips and signal multiplexing electronics integrally mounted to a four position pressure selector switch. One of the four positions of the pressure selector switch allows the in situ calibration of the 16 pressure sensors; the three other positions allow 48 channels (three sets of 16) pressure inputs to be measured by sensors. The small size of the sensor module will allow mounting within many wind-tunnel models, thus eliminating long tube lengths and their corresponding slow pressure response.

System for detecting operating errors in a variable valve timing engine using pressure sensors

DOEpatents

Wiles, Matthew A.; Marriot, Craig D

2013-07-02

A method and control module includes a pressure sensor data comparison module that compares measured pressure volume signal segments to ideal pressure volume segments. A valve actuation hardware remedy module performs a hardware remedy in response to comparing the measured pressure volume signal segments to the ideal pressure volume segments when a valve actuation hardware failure is detected.

ODP Site 1063 (Bermuda Rise) revisited: Oxygen isotopes, excursions and paleointensity in the Brunhes Chron

NASA Astrophysics Data System (ADS)

Channell, J. E. T.; Hodell, D. A.; Curtis, J. H.

2012-02-01

An age model for the Brunhes Chron of Ocean Drilling Program (ODP) Site 1063 (Bermuda Rise) is constructed by tandem correlation of oxygen isotope and relative paleointensity data to calibrated reference templates. Four intervals in the Brunhes Chron where paleomagnetic inclinations are negative for both u-channel samples and discrete samples are correlated to the following magnetic excursions with Site 1063 ages in brackets: Laschamp (41 ka), Blake (116 ka), Iceland Basin (190 ka), Pringle Falls (239 ka). These ages are consistent with current age estimates for three of these excursions, but not for "Pringle Falls" which has an apparent age older than a recently published estimate by ˜28 kyr. For each of these excursions (termed Category 1 excursions), virtual geomagnetic poles (VGPs) reach high southerly latitudes implying paired polarity reversals of the Earth's main dipole field, that apparently occurred in a brief time span (<2 kyr in each case), several times shorter than the apparent duration of regular polarity transitions. In addition, several intervals of low paleomagnetic inclination (low and negative in one case) are observed both in u-channel and discrete samples at ˜318 ka (MIS 9), ˜412 ka (MIS 11) and in the 500-600 ka interval (MIS 14-15). These "Category 2" excursions may constitute inadequately recorded (Category 1) excursions, or high amplitude secular variation.

Multipathway modulation of exercise and glucose stress effects upon GH secretion in healthy men.

PubMed

Veldhuis, Johannes D; Olson, Thomas P; Takahashi, Paul Y; Miles, John M; Joyner, Michael J; Yang, Rebecca J; Wigham, Jean

2015-09-01

Exercise evokes pulsatile GH release followed by autonegative feedback, whereas glucose suppresses GH release followed by rebound-like GH release (feedforward escape). Here we test the hypothesis that age, sex steroids, insulin, body composition and physical power jointly determine these dynamic GH responses. This was a prospectively randomized glucose-blinded study conducted in the Mayo Center for Advancing Translational Sciences in healthy men ages 19-77 years (N=23). Three conditions, fasting/rest/saline, fasting/exercise/saline and fasting/rest/iv glucose infusions, were used to drive GH dynamics during 10-min blood sampling for 6h. Linear correlation analysis was applied to relate peak/nadir GH dynamics to age, sex steroids, insulin, CT-estimated abdominal fat and physical power (work per unit time). Compared with the fasting/rest/saline (control) day, fasting/exercise/saline infusion evoked peak GH within 1h, followed by negative feedback 3-5h later. The dynamic GH excursion was strongly (R(2)=0.634) influenced by (i) insulin negatively (P=0.011), (ii) power positively (P=0.0008), and (iii) E2 positively (P=0.001). Dynamic glucose-modulated GH release was determined by insulin negatively (P=0.0039) and power positively (P=0.0034) (R(2)=0.454). Under rest/saline, power (P=0.031) and total abdominal fat (P=0.012) (R(2)=0.267) were the dominant correlates of GH excursions. In healthy men, dynamic GH perturbations induced by exercise and glucose are strongly related to physical power, insulin, estradiol, and body composition, thus suggesting a network of regulatory pathways. Copyright © 2015 Elsevier Inc. All rights reserved.

Towards co-packaging of photonics and microelectronics in existing manufacturing facilities

NASA Astrophysics Data System (ADS)

Janta-Polczynski, Alexander; Cyr, Elaine; Bougie, Jerome; Drouin, Alain; Langlois, Richard; Childers, Darrell; Takenobu, Shotaro; Taira, Yoichi; Lichoulas, Ted W.; Kamlapurkar, Swetha; Engelmann, Sebastian; Fortier, Paul; Boyer, Nicolas; Barwicz, Tymon

2018-02-01

The impact of integrated photonics on optical interconnects is currently muted by challenges in photonic packaging and in the dense integration of photonic modules with microelectronic components on printed circuit boards. Single mode optics requires tight alignment tolerance for optical coupling and maintaining this alignment in a cost-efficient package can be challenging during thermal excursions arising from downstream microelectronic assembly processes. In addition, the form factor of typical fiber connectors is incompatible with the dense module integration expected on printed circuit boards. We have implemented novel approaches to interfacing photonic chips to standard optical fibers. These leverage standard high throughput microelectronic assembly tooling and self-alignment techniques resulting in photonic packaging that is scalable in manufacturing volume and in the number of optical IOs per chip. In addition, using dense optical fiber connectors with space-efficient latching of fiber patch cables results in compact module size and efficient board integration, bringing the optics closer to the logic chip to alleviate bandwidth bottlenecks. This packaging direction is also well suited for embedding optics in multi-chip modules, including both photonic and microelectronic chips. We discuss the challenges and rewards in this type of configuration such as thermal management and signal integrity.

Deciphering the impact of diagenesis overprint on negative δ13C excursions using rock magnetism: Case study of Ediacaran carbonates, Yangjiaping section, South China

NASA Astrophysics Data System (ADS)

Macouin, Mélina; Ader, Magali; Moreau, Marie-Gabrielle; Poitou, Charles; Yang, Zhenyu; Sun, Zhimming

2012-10-01

Rock magnetism is used here to investigate the genesis of one of the puzzling negative carbon isotopic excursions of the Neoproterozoic in the Yangtze platform (South China). A detailed characterization of the magnetic mineralogy, which includes low-temperature and high-field magnetometry and classical magnetic measurement (ARM, IRM, susceptibility), was therefore performed along upper Doushantuo and lower Dengying Formations outcropping in the Yangjiaping section. The derived magnetic parameters show variations that can be interpreted as variations in magnetic grains size and in oxide contents. They show that the magnetic content is significantly reduced in samples presenting negative δ13Ccalcite values. We interpret this as a result of magnetite dissolution and secondary carbonate precipitation during early diagenesis bacterial sulfate reduction. Combined with C and O isotopic data, paleomagnetic techniques thus show that the upper Doushantuo-lower Dengying negative excursion of the Yangjiaping section is largely due to diagenesis, although the preservation of a genuine δ13C excursion of lower magnitude from +7‰ down to 0‰, instead of down to -9‰ as usually considered, cannot be ruled out. A corrected δ13Ccarbonate chemostratigraphic curve is therefore proposed. The unambiguous identification of a strong diagenetic component for this excursion casts doubts on the primary nature of other potentially time equivalent negative excursions of the Yangtze platform and thus to its correlation to negative excursions in other cratons (i.e. Shuram excursion). More generally, this study illustrates the potential of magnetic mineralogy characterization, a low cost, time efficient and non-destructive technique, as screening tool for diagenetic overprints of δ13C and δ18O.

Use of an Anatomical Scalar to Control for Sex-Based Size Differences in Measures of Hyoid Excursion during Swallowing

ERIC Educational Resources Information Center

Molfenter, Sonja M.; Steele, Catriona M.

2014-01-01

Purpose: Traditional methods for measuring hyoid excursion from dynamic videofluoroscopy recordings involve calculating changes in position in absolute units (mm). This method shows a high degree of variability across studies but agreement that greater hyoid excursion occurs inmen than in women. Given that men are typically taller than women, the…

Relation of Phanerozoic stable isotope excursions to climate, bacterial metabolism, and major extinctions

PubMed Central

Stanley, Steven M.

2010-01-01

Conspicuous global stable carbon isotope excursions that are recorded in marine sedimentary rocks of Phanerozoic age and were associated with major extinctions have generally paralleled global stable oxygen isotope excursions. All of these phenomena are therefore likely to share a common origin through global climate change. Exceptional patterns for carbon isotope excursions resulted from massive carbon burial during warm intervals of widespread marine anoxic conditions. The many carbon isotope excursions that parallel those for oxygen isotopes can to a large degree be accounted for by the Q10 pattern of respiration for bacteria: As temperature changed along continental margins, where ∼90% of marine carbon burial occurs today, rates of remineralization of isotopically light carbon must have changed exponentially. This would have reduced organic carbon burial during global warming and increased it during global cooling. Also contributing to the δ13C excursions have been release and uptake of methane by clathrates, the positive correlation between temperature and degree of fractionation of carbon isotopes by phytoplankton at temperatures below ∼15°, and increased phytoplankton productivity during “icehouse” conditions. The Q10 pattern for bacteria and climate-related changes in clathrate volume represent positive feedbacks for climate change. PMID:21041682

Highway driving safety the day after using sleep medication: the direction of lapses and excursions out-of-lane in drowsy drivers.

PubMed

Verster, Joris C; Mooren, Loes; Bervoets, Adriana C; Roth, Thomas

2017-10-24

The primary outcome measure of the on-road driving test is the Standard Deviation of Lateral Position. However, other outcome measures, such as lapses and excursions out-of-lane, also need to be considered as they may be related to crash risk. The aim of this study was to determine the direction of lapses and excursions out-of-lane (i.e. towards/into the adjacent traffic lane or towards/into the road shoulder). In total, data from 240 driving tests were re-analysed, and 628 lapses and 401 excursions out-of-lane were identified. The analyses revealed that lapses were made equally frequently over left (49.4%) and over right (43.3%). In contrast, excursions out-of-lane were almost exclusively directed over right into the (safer) road shoulder (97.3%). These findings suggest that drivers are unaware of having lapses, whereas excursions out-of-lane are events where the driver is aware of loss of vehicle control. © 2017 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

Kinematic analysis of postural reactions to a posterior translation in rocker bottom shoes in younger and older adults.

PubMed

Kimel-Scott, Dorothy R; Gulledge, Elisha N; Bolena, Ryan E; Albright, Bruce C

2014-01-01

Shoes with rocker bottom soles are utilized by persons with diabetic peripheral neuropathy to reduce plantar pressures during gait. The risk of falls increases with age and is compounded by diabetic neuropathy. The purpose of this study was to analyze how rocker bottom shoes affect posture control of older adults (50-75 years old) and younger adults (20-35 years old) in response to posterior slide perturbations. The postural response to a posterior platform translation was normalized among subjects by applying the below threshold stepping velocity (BTSV) for each subject. The BTSV was the fastest velocity of platform translation that did not cause a stepping response while wearing the rocker bottom shoes. Joint excursion, time to first response, response time, and variability of mean peak joint angles were analyzed at the ankle, knee, hip, trunk, and head in the sagittal plane. The statistical analysis was a 2-factor mixed repeated measures design to determine interactions between and within shoe types and age groups. While wearing rocker bottom shoes, both age groups exhibited increased joint excursion, differences in time to initial response, and longer response time. The older group demonstrated decreased joint excursion and increased time to initial response compared to the younger group, as well as a significantly slower mean BTSV. These findings support the conclusion that in healthy older adults and in populations at risk for falls, the use of rocker bottom or other unstable shoes may increase the potential of falls when confronted with a standing perturbation such as a forceful slip or trip. Copyright © 2013 Elsevier B.V. All rights reserved.

Apollo Rendezvous Docking Simulator

NASA Image and Video Library

1964-11-02

Originally the Rendezvous was used by the astronauts preparing for Gemini missions. The Rendezvous Docking Simulator was then modified and used to develop docking techniques for the Apollo program. The pilot is shown maneuvering the LEM into position for docking with a full-scale Apollo Command Module. From A.W. Vogeley, Piloted Space-Flight Simulation at Langley Research Center, Paper presented at the American Society of Mechanical Engineers, 1966 Winter Meeting, New York, NY, November 27 - December 1, 1966. The Rendezvous Docking Simulator and also the Lunar Landing Research Facility are both rather large moving-base simulators. It should be noted, however, that neither was built primarily because of its motion characteristics. The main reason they were built was to provide a realistic visual scene. A secondary reason was that they would provide correct angular motion cues (important in control of vehicle short-period motions) even though the linear acceleration cues would be incorrect. Apollo Rendezvous Docking Simulator: Langley s Rendezvous Docking Simulator was developed by NASA scientists to study the complex task of docking the Lunar Excursion Module with the Command Module in Lunar orbit.

Dynamic Postural-Stability Deficits After Cryotherapy to the Ankle Joint

PubMed Central

Fullam, Karl; Caulfield, Brian; Coughlan, Garrett F.; McGroarty, Mark; Delahunt, Eamonn

2015-01-01

Context  Decreased postural stability is a primary risk factor for lower limb musculoskeletal injuries. During athletic competitions, cryotherapy may be applied during short breaks in play or during half-time; however, its effects on postural stability remain unclear. Objective  To investigate the acute effects of a 15-minute ankle-joint cryotherapy application on dynamic postural stability. Design  Controlled laboratory study. Setting  University biomechanics laboratory. Patients or Other Participants  A total of 29 elite-level collegiate male field-sport athletes (age = 20.8 ± 1.12 years, height = 1.80 ± 0.06 m, mass = 81.89 ± 8.59 kg) participated. Intervention(s)  Participants were tested on the anterior (ANT), posterolateral (PL), and posteromedial (PM) reach directions of the Star Excursion Balance Test before and after a 15-minute ankle-joint cryotherapy application. Main Outcome Measure(s)  Normalized reach distances; sagittal-plane kinematics of the hip, knee, and ankle joints; and associated mean velocity of the center-of-pressure path during performance of the ANT, PL, and PM reach directions of the Star Excursion Balance Test. Results  We observed a decrease in reach-distance scores for the ANT, PL, and PM reach directions from precryotherapy to postcryotherapy (P < .05). No differences were observed in hip-, knee-, or ankle-joint sagittal-plane kinematics (P > .05). We noted a decrease in mean velocity of the center-of-pressure path from precryotherapy to postcryotherapy (P < .05) in all reach directions. Conclusions  Dynamic postural stability was adversely affected immediately after cryotherapy to the ankle joint. PMID:26285088

The Delta launch vehicle Model 2914 series

NASA Technical Reports Server (NTRS)

Gunn, C. R.

1973-01-01

Description of a new, medium-class Delta launch-vehicle configuration, the three-stage Model 2914. The first stage of this vehicle is composed of a liquid-propellant core which is thrust-augmented with up to nine strap-on solid-propellant motors. The second stage, recently uprated with a strap-down inertial guidance system, is now being modified to adapt the liquid-propellant descent engine from the Apollo Lunar Excursion Module. The third stage is a spin-stabilized solid-propellant motor. The Model 2914 is capable of injecting 2040 kg into low earth orbit, 705 kg into geosynchronous transfer orbit, or 455 kg into an escape trajectory.

Manned Mars mission environmental control and life support subsystem

NASA Technical Reports Server (NTRS)

Hueter, Uwe

1986-01-01

A specific design is not presented, but the general philosophy regarding potential Environmental Control/Life Support System (ECLSS) requirements, concepts, issues, and technology needs are discussed. The focus is on a manned Mars mission occurring in the late 1990's. Discussions on the Trans-Mars Vehicle, the Mars Excursion Module (MEM), and a Martian base facility are covered. The functions, performance requirements, and design loads of a typical ECLSS are listed, and the issues and technology briefly discussed. Several ECLSS concepts and options are identified, and comparative weights and volumes are provided for these. Several aspects of the space station ECLSS are contrasted with the Mars element ECLSS.

Evaluating OSHA's ethylene oxide standard: exposure determinants in Massachusetts hospitals.

PubMed Central

LaMontagne, A D; Kelsey, K T

2001-01-01

OBJECTIVES: This study sought to identify determinants of workplace exposures to ethylene oxide to assess the effect of the Occupational Safety and Health Administration's (OSHA's) 1984 ethylene oxide standard. METHODS: An in-depth survey of all hospitals in Massachusetts that used ethylene oxide from 1990 through 1992 (96% participation, N = 90) was conducted. Three types of exposure events were modeled with logistic regression: exceeding the 8-hour action level, exceeding the 15-minute excursion limit, and worker exposures during unmeasured accidental releases. Covariates were drawn from data representing an ecologic framework including direct and indirect potential exposure determinants. RESULTS: After adjustment for frequencies of ethylene oxide use and exposure monitoring, a significant inverse relation was observed between exceeding the action level and the use of combined sterilizer-aerators, an engineering control technology developed after the passage of the OSHA standard. Conversely, the use of positive-pressure sterilizers that employ ethylene oxide gas mixtures was strongly related to both exceeding the excursion limit and the occurrence of accidental releases. CONCLUSIONS: These findings provide evidence of a positive effect of OSHA's ethylene oxide standard and specific targets for future prevention and control efforts. PMID:11236406

Changes in postural sway as a consequence of wearing a military backpack.

PubMed

Heller, Michelle F; Challis, John H; Sharkey, Neil A

2009-07-01

Military personnel are often required to carry all of their personal supplies and equipment for long distances during both training and combat situations, creating many biomechanical and postural challenges for these individuals. In addition to other problems such as generalized fatigue and the development of stress fractures, significant external loads may also affect a soldier's postural sway. The purpose of this study was to assess changes in postural sway as a consequence of wearing a military backpack in females. Forty-three female subjects between the ages of 18 and 25 volunteered to participate. There were two conditions: unloaded and while wearing an 18.1 kg military backpack. Each subject stood with two feet on a force platform for 30s under both conditions while center of pressure (COP) data were collected. COP path length increased 64%, medial-lateral excursion increased 131%, anterior-posterior excursion increased 54%, and COP area increased 229% with addition of the backpack (p<0.0001 for all of these measures). These data show that wearing 18.1 kg of external weight in a military backpack increases the postural sway of females, which may in turn increase the likelihood of falls and injury.

Leg kinematics and muscle activity during treadmill running in the cockroach, Blaberus discoidalis: I. Slow running.

PubMed

Watson, J T; Ritzmann, R E

1998-01-01

We have combined high-speed video motion analysis of leg movements with electromyogram (EMG) recordings from leg muscles in cockroaches running on a treadmill. The mesothoracic (T2) and metathoracic (T3) legs have different kinematics. While in each leg the coxa-femur (CF) joint moves in unison with the femurtibia (FT) joint, the relative joint excursions differ between T2 and T3 legs. In T3 legs, the two joints move through approximately the same excursion. In T2 legs, the FT joint moves through a narrower range of angles than the CF joint. In spite of these differences in motion, no differences between the T2 and T3 legs were seen in timing or qualitative patterns of depressor coxa and extensor tibia activity. The average firing frequencies of slow depressor coxa (Ds) and slow extensor tibia (SETi) motor neurons are directly proportional to the average angular velocity of their joints during stance. The average Ds and SETi firing frequency appears to be modulated on a cycle-by-cycle basis to control running speed and orientation. In contrast, while the frequency variations within Ds and SETi bursts were consistent across cycles, the variations within each burst did not parallel variations in the velocity of the relevant joints.

Right ventricular function in acute pulmonary embolism: a combined assessment by three-dimensional and speckle-tracking echocardiography.

PubMed

Vitarelli, Antonio; Barillà, Francesco; Capotosto, Lidia; D'Angeli, Ilaria; Truscelli, Giovanni; De Maio, Melissa; Ashurov, Rasul

2014-03-01

The aim of this study was to assess changes in right ventricular (RV) parameters determined by three-dimensional (3D) echocardiography and speckle-tracking echocardiography in patients with acute pulmonary embolism and RV dysfunction without systemic hypotension (submassive pulmonary embolism). Sixty-six patients were prospectively studied at the onset of the acute episode and after median follow-up periods of 30 days and 6 months. Sixty-six controls were selected. RV fractional area change, tricuspid annular plane systolic excursion, and myocardial performance index were determined. RV systolic pressure was assessed using continuous-wave Doppler echocardiography. Three-dimensional RV ejection fraction (RVEF) was calculated. Two-dimensional peak systolic RV longitudinal strain (RVLS) was measured in the basal free wall, mid free wall (MFW), and apical free wall and the septum. Tricuspid annular plane systolic excursion and fractional area change were smaller and myocardial performance index was larger compared with controls (P < .05). Global RVLS (P < .05), MFW RVLS (P < .001), and 3D RVEF (P < .001) were lower in patients with pulmonary embolism than in controls. There was earlier reversal of MFW RVLS values on 30-day follow-up and longer reversal of 3D RVEF and RV systolic pressure values at 6-month follow-up. Receiver operating characteristic curve analysis showed that changes in 3D RVEF and MFW RVLS were the most sensitive predictors of adverse events. By multivariate analysis, RV systolic pressure (P = .007), MFW RVLS (P = .002), and 3D RVEF (P = .001) were independently associated with adverse outcomes. Acute submassive pulmonary embolism has a significant impact on RV function as assessed by 3D echocardiography and speckle-tracking echocardiography. Decreases in MFW RVLS and 3D RVEF may persist during short-term and long-term follow-up and correlate with unfavorable outcomes. Copyright © 2014 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.

Role of right ventricle and dynamic pulmonary hypertension on determining ΔVO2/ΔWork Rate flattening: insights from cardiopulmonary exercise test combined with exercise echocardiography.

PubMed

Bandera, Francesco; Generati, Greta; Pellegrino, Marta; Donghi, Valeria; Alfonzetti, Eleonora; Gaeta, Maddalena; Villani, Simona; Guazzi, Marco

2014-09-01

Several cardiovascular diseases are characterized by an impaired O2 kinetic during exercise. The lack of a linear increase of Δoxygen consumption (VO2)/ΔWork Rate (WR) relationship, as assessed by expired gas analysis, is considered an indicator of abnormal cardiovascular efficiency. We aimed at describing the frequency of ΔVO2/ΔWR flattening in a symptomatic population of cardiac patients, characterizing its functional profile, and testing the hypothesis that dynamic pulmonary hypertension and right ventricular contractile reserve play a major role as cardiac determinants. We studied 136 patients, with different cardiovascular diseases, referred for exertional dyspnoea. Cardiopulmonary exercise test combined with simultaneous exercise echocardiography was performed using a symptom-limited protocol. ΔVO2/ΔWR flattening was observed in 36 patients (group A, 26.5% of population) and was associated with a globally worse functional profile (reduced peak VO2, anaerobic threshold, O2 pulse, impaired VE/VCO2). At univariate analysis, exercise ejection fraction, exercise mitral regurgitation, rest and exercise tricuspid annular plane systolic excursion, exercise systolic pulmonary artery pressure, and exercise cardiac output were all significantly (P<0.05) impaired in group A. The multivariate analysis identified exercise systolic pulmonary artery pressure (odds ratio, 1.06; confidence interval, 1.01-1.11; P=0.01) and exercise tricuspid annular plane systolic excursion (odds ratio, 0.88; confidence interval, 0.80-0.97; P=0.01) as main cardiac determinants of ΔVO2/ΔWR flattening; female sex was strongly associated (odds ratio, 6.10; confidence interval, 2.11-17.7; P<0.01). In patients symptomatic for dyspnea, the occurrence of ΔVO2/ΔWR flattening reflects a significantly impaired functional phenotype whose main cardiac determinants are the excessive systolic pulmonary artery pressure increase and the reduced peak right ventricular longitudinal systolic function. © 2014 American Heart Association, Inc.

Modeling the Impact of Forest and Peat Fires on Carbon-Isotopic Compositions of Cretaceous Atmosphere and Vegetation

NASA Astrophysics Data System (ADS)

Finkelstein, D. B.; Pratt, L. M.

2004-12-01

Prevalence of wildfires or peat fires associated with seasonally dry conditions in the Cretaceous is supported by recent studies documenting the widespread presence of pyrolytic polycyclic aromatic hydrocarbons and fusinite. Potential roles of CO2 emissions from fire have been overlooked in many discussions of Cretaceous carbon-isotope excursions (excluding K-P boundary discussions). Enhanced atmospheric CO2 levels could increase fire frequency through elevated lightning activity. When biomass or peat is combusted, emissions of CO2 are more negative than atmospheric CO2. Five reservoirs (atmosphere, vegetation, soil, and shallow and deep oceans), and five fluxes (productivity, respiration, litter fall, atmosphere-ocean exchange, and surface-deep ocean exchange) were modeled as a closed system. The size of the Cretaceous peat reservoir was estimated by compilation of published early Cretaceous coal resources. Initial pCO2 was assumed to be 2x pre-industrial atmospheric levels (P.A.L.). Critical variables in the model are burning efficiency and post-fire growth rates. Assuming 1% of standing terrestrial biomass is consumed by wildfires each year for ten years (without combustion of peat), an increase of atmospheric CO2 (from 2.0 to 2.2x P.A.L.) and a negative carbon isotope excursion (-1.2 ‰ ) are recorded by both atmosphere and new growth. Net primary productivity linked to the residence time of the vegetation and soil reservoirs results in a negative isotope shift followed by a broad positive isotope excursion. Decreasing the rate of re-growth dampens this trailing positive shift and increases the duration of the excursion. Post-fire pCO2 and new growth returned to initial values after 72 years. Both negative and positive isotope excursions are recorded in the model in surface ocean waters. Exchange of CO2 with the surface- and deep-ocean dampens the isotopic shift of the atmosphere. Excursions are first recorded in the atmosphere (and new growth), followed by the ocean, vegetation, and soil reservoirs. Ten to twenty five-year cycles of drought and fire are not recorded as individual excursions in the soil reservoir as the rate of transfer between the vegetation and soil reservoirs homogenizes the signal. A wildfire-modeled excursion does not propagate a geologically significant excursion through time. Combustion of a peat reservoir is necessary to drive and validate a geologically and isotopically significant excursion. Assuming 0.5% of the standing early Cretaceous peat reservoir is consumed by fire for each year for ten years coupled with the earlier scenario, the atmospheric CO2 increases from 2.0 to 3.1x P.A.L., atmosphere, vegetation, and the surface ocean record a negative carbon isotope excursion of -5.1 ‰ , -3.8 ‰ and -1.8 ‰ respectively, with a duration of 741 years. Increasing the size of the vegetation reservoir translates the excursions from the centennial to millennial scale. For example, doubling the vegetation reservoir (from 1.4 to 2.8E+16 gC) for a 25 year global peat conflagration (0.5% combusted each year) results in a CO2 increase from 2.0 to 4.0x P.A.L., and the atmosphere, vegetation, and the surface ocean reservoirs with a negative carbon isotope excursion of -5.7 ‰ , -8.7 ‰ and -2.3 ‰ respectively. Addition of carbonaceous aerosols (black carbon and polycyclic aromatic hydrocarbons) to pelagic marine sediments could potentially serve as a high-resolution record of ancient fires and firmly tie isotopic shifts to paleofires.

Assessment of vertical excursions and open-sea psychological performance at depths to 250 fsw.

PubMed

Miller, J W; Bachrach, A J; Walsh, J M

1976-12-01

A series of 10 two-man descending vertical excursion dives was carried out in the open sea from an ocean-floor habitat off the coast of Puerto Rico by four aquanauts saturated on a normoxic-nitrogen breathing mixture at a depth of 106 fsw. The purpose of these dives was two-fold: to validate laboratory findings with respect to decompression schedules and to determine whether such excursions would produce evidence of adaptation to nitrogen narcosis. For the latter, tests designed to measure time estimation, short-term memory, and auditory vigilance were used. The validation of experimental excursion tables was carried out without incidence of decompression sickness. Although no signs of nitrogen narcosis were noted during testing, all subjects made significantly longer time estimates in the habitat and during the excursions than on the surface. Variability and incomplete data prevented a statistical analysis of the short-term memory results, and the auditory vigilance proved unusable in the water.

Human risk factors associated with pilots in runway excursions.

PubMed

Chang, Yu-Hern; Yang, Hui-Hua; Hsiao, Yu-Jung

2016-09-01

A breakdown analysis of civil aviation accidents worldwide indicates that the occurrence of runway excursions represents the largest portion among all aviation occurrence categories. This study examines the human risk factors associated with pilots in runway excursions, by applying a SHELLO model to categorize the human risk factors and to evaluate the importance based on the opinions of 145 airline pilots. This study integrates aviation management level expert opinions on relative weighting and improvement-achievability in order to develop four kinds of priority risk management strategies for airline pilots to reduce runway excursions. The empirical study based on experts' evaluation suggests that the most important dimension is the liveware/pilot's core ability. From the perspective of front-line pilots, the most important risk factors are the environment, wet/containment runways, and weather issues like rain/thunderstorms. Finally, this study develops practical strategies for helping management authorities to improve major operational and managerial weaknesses so as to reduce the human risks related to runway excursions. Copyright © 2016 Elsevier Ltd. All rights reserved.

The metatarsosesamoid joint: an in vitro 3D quantitative assessment.

PubMed

Jamal, Bilal; Pillai, Anand; Fogg, Quentin; Kumar, Senthil

2015-03-01

The anatomy of the first metatarsophalangeal (MTP) joint, particularly the metatarsosesamoid articulation, remains poorly understood. Our goal was to quantitatively define the excursion of the sesamoids. Seven cadavers were dissected to assess the articulating surfaces throughout a normal range of motion. The dissections were digitally reconstructed in various positions using a MicroScribe. For first MTP joint, excursion averaged 14.7mm for the tibial sesamoid in the sagittal plane and 7.5mm for the fibular sesamoid. The sesamoids also moved medially to laterally when the joint was dorsiflexed. For the maximally dorsiflexed joint, excursion averaged 2.8mm for the tibial sesamoid and 3.5mm for the fibular sesamoid. Hallucal sesamoids appear to have differential tracking: the tibial sesamoid has greater longitudinal excursion; the fibular sesamoid has greater lateral excursion. The anatomical data will interest those involved with the design of an effective hallux arthroplasty. Copyright © 2014 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Geomagnetic field excursion recorded 17 ka at Tianchi Volcano, China: New 40Ar/39Ar age and significance

NASA Astrophysics Data System (ADS)

Singer, Brad S.; Jicha, Brian R.; He, Huaiyu; Zhu, Rixiang

2014-04-01

New 40Ar/39Ar dating of a comenditic lava atop Tianchi Volcano, China, indicates eruption at 17.1 ± 0.9 ka. The flow interior records a pair of transitional virtual geomagnetic poles and a low paleointensity of ~25 μT. Thus, it records a geomagnetic field excursion that is younger than the 41 ka Laschamp or 32 ka Auckland excursions. Implications are: (1) following a repose of several tens of kyr, Tianchi Volcano became highly active immediately following termination of the last glaciation maximum. The flare-up of silicic eruptions may reflect rapid deglaciation of the edifice. (2) A 17 ka age for the Tianchi excursion provides the first direct radioisotopic evidence that excursional behavior, which is imprecisely dated and less well documented magnetically at several other sites, is a global feature of geodynamo behavior. (3) During the Brunhes chron, 13 well-dated excursions cluster into two periods, including seven between 17 and 212 ka, and six between about 530 and 730 ka.

Nuclear Engineering Computer Modules, Thermal-Hydraulics, TH-1: Pressurized Water Reactors.

ERIC Educational Resources Information Center

Reihman, Thomas C.

This learning module is concerned with the temperature field, the heat transfer rates, and the coolant pressure drop in typical pressurized water reactor (PWR) fuel assemblies. As in all of the modules of this series, emphasis is placed on developing the theory and demonstrating its use with a simplified model. The heart of the module is the PWR…

Creep Burst Testing of a Woven Inflatable Module

NASA Technical Reports Server (NTRS)

Selig, Molly M.; Valle, Gerard D.; James, George H.; Oliveras, Ovidio M.; Jones, Thomas C.; Doggett, William R.

2015-01-01

A woven Vectran inflatable module 88 inches in diameter and 10 feet long was tested at the NASA Johnson Space Center until failure from creep. The module was pressurized pneumatically to an internal pressure of 145 psig, and was held at pressure until burst. The external environment remained at standard atmospheric temperature and pressure. The module burst occurred after 49 minutes at the target pressure. The test article pressure and temperature were monitored, and video footage of the burst was captured at 60 FPS. Photogrammetry was used to obtain strain measurements of some of the webbing. Accelerometers on the test article measured the dynamic response. This paper discusses the test article, test setup, predictions, observations, photogrammetry technique and strain results, structural dynamics methods and quick-look results, and a comparison of the module level creep behavior to the strap level creep behavior.

A new electronic scanner of pressure designed for installation in wind-tunnel models

NASA Technical Reports Server (NTRS)

Coe, C. T.; Parra, G. T.; Kauffman, R. C.

1981-01-01

A new electronic scanner of pressure (ESOP) has been developed by NASA Ames Research Center for installation in wind-tunnel models. An ESOP system includes up to 20 pressure modules, each with 48 pressure transducers, an A/D converter, a microprocessor, a data controller, a monitor unit, and a heater controller. The system is sized so that the pressure modules and A/D converter module can be installed within an average-size model tested in the Ames Aerodynamics Division wind tunnels. This paper describes the ESOP system, emphasizing the main element of the system - the pressure module. The measured performance of the overall system is also presented.

Physical property changes in hydrate-bearing sediment due to depressurization and subsequent repressurization

USGS Publications Warehouse

Waite, W.F.; Kneafsey, T.J.; Winters, W.J.; Mason, D.H.

2008-01-01

Physical property measurements of sediment cores containing natural gas hydrate are typically performed on material exposed, at least briefly, to non-in situ conditions during recovery. To examine the effects of a brief excursion from the gas-hydrate stability field, as can occur when pressure cores are transferred to pressurized storage vessels, we measured physical properties on laboratory-formed sand packs containing methane hydrate and methane pore gas. After depressurizing samples to atmospheric pressure, we repressurized them into the methane-hydrate stability field and remeasured their physical properties. Thermal conductivity, shear strength, acoustic compressional and shear wave amplitudes, and speeds of the original and depressurized/repressurized samples are compared. X– ray computed tomography images track how the gas-hydrate distribution changes in the hydrate-cemented sands owing to the depressurizaton/repressurization process. Because depressurization-induced property changes can be substantial and are not easily predicted, particularly in water-saturated, hydrate-bearing sediment, maintaining pressure and temperature conditions throughout the core recovery and measurement process is critical for using laboratory measurements to estimate in situ properties.

Physical property changes in hydrate-bearing sediment due to depressurization and subsequent repressurization

USGS Publications Warehouse

Waite, W.F.; Kneafsey, T.J.; Winters, W.J.; Mason, D.H.

2008-01-01

Physical property measurements of sediment cores containing natural gas hydrate are typically performed on material exposed, at least briefly, to non-in situ conditions during recovery. To examine the effects of a brief excursion from the gas-hydrate stability field, as can occur when pressure cores are transferred to pressurized storage vessels, we measured physical properties on laboratory-formed sand packs containing methane hydrate and methane pore gas. After depressurizing samples to atmospheric pressure, we repressurized them into the methane-hydrate stability field and remeasured their physical properties. Thermal conductivity, shear strength, acoustic compressional and shear wave amplitudes, and speeds of the original and depressurized/repressurized samples are compared. X-ray computed tomography images track how the gas-hydrate distribution changes in the hydrate-cemented sands owing to the depressurizaton/repressurization process. Because depressurization-induced property changes can be substantial and are not easily predicted, particularly in water-saturated, hydrate-bearing sediment, maintaining pressure and temperature conditions throughout the core recovery and measurement process is critical for using laboratory measurements to estimate in situ properties.

Head Excursion of Restrained Human Volunteers and Hybrid III Dummies in Steady State Rollover Tests

PubMed Central

Moffatt, Edward; Hare, Barry; Hughes, Raymond; Lewis, Lance; Iiyama, Hiroshi; Curzon, Anne; Cooper, Eddie

2003-01-01

Seatbelts provide substantial benefits in rollover crashes, yet occupants still receive head and neck injuries from contacting the vehicle roof interior when the roof exterior strikes the ground. Prior research has evaluated rollover restraint performance utilizing anthropomorphic test devices (dummies), but little dynamic testing has been done with human volunteers to learn how they move during rollovers. In this study, the vertical excursion of the head of restrained dummies and human subjects was measured in a vehicle being rotated about its longitudinal roll axis at roll rates from 180-to-360 deg/sec and under static inversion conditions. The vehicle’s restraint design was the commonly used 3-point seatbelt with continuous loop webbing and a sliding latch plate. This paper presents an analysis of the observed occupant motion and provides a comparison of dummy and human motion under similar test conditions. Thirty-five tests (eighteen static and seventeen dynamic) were completed using two different sizes of dummies and human subjects in both near and far-side roll directions. The research indicates that far-side rollovers cause the restrained test subjects to have greater head excursion than near-side rollovers, and that static inversion testing underestimates head excursion for far-side occupants. Human vertical head excursion of up to 200 mm was found at a roll rate of 220 deg/sec. Humans exhibit greater variability in head excursion in comparison to dummies. Transfer of seatbelt webbing through the latch plate did not correlate directly with differences in head excursion. PMID:12941241

Record of the Late Devonian Hangenberg global positive carbon-isotope excursion in an epeiric sea setting: Carbonate production, organic-carbon burial and paleoceanography during the late Famennian

USGS Publications Warehouse

Cramer, Bradley D.; Saltzman, Matthew R.; Day, J.E.; Witzke, B.J.

2008-01-01

Latest Famennian marine carbonates from the mid-continent of North America were examined to investigate the Late Devonian (very late Famennian) Hangenberg positive carbon-isotope (??13 Ccarb) excursion. This global shift in the ?? 13C of marine waters began during the late Famennian Hangenberg Extinction Event that occurred during the Middle Siphonodella praesulcata conodont zone. The post-extinction recovery interval spans the Upper S. praesulcata Zone immediately below the Devonian-Carboniferous boundary. Positive excursions in ?? 13 Ccarb are often attributed to the widespread deposition of organic-rich black shales in epeiric sea settings. The Hangenberg ??13 Ccarb excursion documented in the Louisiana Limestone in this study shows the opposite trend, with peak ??13 Ccarb values corresponding to carbonate production in the U.S. mid-continent during the highstand phase of the very late Famennian post-glacial sea level rise. Our data indicate that the interval of widespread black shale deposition (Hangenberg Black Shale) predates the peak isotope values of the Hangenberg ??13 Ccarb excursion and that peak values of the Hangenberg excursion in Missouri are not coincident with and cannot be accounted for by high Corg burial in epeiric seas. We suggest instead that sequestration and burial of Corg in the deep oceans drove the peak interval of the ??13Ccarb excursion, as a result of a change in the site of deep water formation to low-latitude epeiric seas as the global climate shifted between cold and warm states.

A paleomagnetic record in loess-paleosol sequences since late Pleistocene in the arid Central Asia

NASA Astrophysics Data System (ADS)

Li, Guanhua; Xia, Dunsheng; Appel, Erwin; Wang, Youjun; Jia, Jia; Yang, Xiaoqiang

2018-03-01

Geomagnetic excursions during Brunhes epoch have been brought to the forefront topic in paleomagnetic study, as they provide key information about Earth's interior dynamics and could serve as another tool for stratigraphic correlation among different lithology. Loess-paleosol sequences provide good archives for decoding geomagnetic excursions. However, the detailed pattern of these excursions was not sufficiently clarified due to pedogenic influence. In this study, paleomagnetic analysis was performed in loess-paleosol sequences on the northern piedmont of the Tianshan Mountains (northwestern China). By radiocarbon and luminance dating, the loess section was chronologically constrained to mainly the last c.130 ka, a period when several distinct geomagnetic excursions were involved. The rock magnetic properties in this loess section are dominated by magnetite and maghemite in a pseudo-single-domain state. The rock magnetic properties and magnetic anisotropy indicate weakly pedogenic influence for magnetic record. The stable component of remanent magnetization derived from thermal demagnetization revealed the presence of two intervals of directional anomalies with corresponding intensity lows in the Brunhes epoch. The age control in the key layers indicates these anomalies are likely associated with the Laschamp and Blake excursions, respectively. In addition, relative paleointensity in the loess section is basically compatible with other regional and global relative paleointensity records and indicates two low-paleointensity zones, possibly corresponding to the Blake and Laschamp excursions, respectively. As a result, this study suggests that the loess section may have the potential to record short-lived excursions, which largely reflect the variation of dipole components in the global archives.

SpalLoop

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

Sabau, Adrian; Wright, Ian

Boiler tubes in steam power plants experience tube blockages due to exfoliation of oxide grown on the inner side of the tubes. In extreme cases, significant tube blockages can lead to forced power plant outages. It is thus desired to predict through modeling the amount of tube blockage in order to inform power plant operators of possible forced outages. SpalLoop solves for the stress-strain equations in an axisymmetric geometry, tracking the stress/strain evolution during boiler operation including outages for the entire boiler tube length. At each operational outage, i.e., temperature excursions down to room temperature, the amount of exfoliated areamore » for the entire tube loop is estimated the amount of tube blockage is predicted based assumed blockage geometry and site. The SpaLLoop code contains modules developed for oxide growth, stress analysis, tube loop geometry, blockage area by taking into account the following phenomena and features, (a) Plant operation schedule with periodic alternate full-load and partial-load regimes and shut-downs, i.e., temperature excursions from high-load to room temperature, (b) axisymmetric formulation for cylindrical tubes, (c) oxide growth in a temperature gradient with multiple oxide layers, (d) geometry of a boiler tube with a single tube loop or two tube loops, (e) temperature variation along the tube length based on hot gas temperature distribution outside the tube and inlet steam temperature, (f) non-uniform oxide growth along the tube length according to the local steam tube temperature, (g) exfoliated area module: at each operational outage considered, the amount of exfoliated area and exfoliated volume along the tube is estimated, (h) blockage module: at each operational outage considered, the exfoliated volume/mass for each tube loop is estimated from which the amount of tube blockage is predicted based on given blockage geometry (length, location, and geometry). The computer program is written in FORTRAN90. Its modular structure was sought for allowing the best flexibility in updating the program by implementing new constitutive equations due to availability of new material property data and/or new physical phenomena.« less

Optimization of the Pressurized Logistics Module - A Space Station Freedom analytical study

NASA Technical Reports Server (NTRS)

Scallan, J. M.

1991-01-01

The analysis for determining the optimum cylindrical length of the Space Station Freedom (SSF) Pressurized Logistics Module, whose task is to transport the SSF pressurized cargo via the NSTS Shuttle Orbiter, is described. The major factors considered include the NSTS net launch lift capability, the pressurized cargo requirements, and the mass properties of the module structures, mechanisms, and subsystems.

A hybrid electronically scanned pressure module for cryogenic environments

NASA Technical Reports Server (NTRS)

Chapman, J. J.; Hopson, P., Jr.; Kruse, N.

1995-01-01

Pressure is one of the most important parameters measured when testing models in wind tunnels. For models tested in the cryogenic environment of the National Transonic Facility at NASA Langley Research Center, the technique of utilizing commercially available multichannel pressure modules inside the models is difficult due to the small internal volume of the models and the requirement of keeping the pressure transducer modules within an acceptable temperature range well above the -173 degrees C tunnel temperature. A prototype multichannel pressure transducer module has been designed and fabricated with stable, repeatable sensors and materials optimized for reliable performance in the cryogenic environment. The module has 16 single crystal silicon piezoresistive pressure sensors electrostatically bonded to a metalized Pyrex substrate for sensing the wind tunnel model pressures. An integral temperature sensor mounted on each silicon micromachined pressure sensor senses real-time temperature fluctuations to within 0.1 degrees C to correct for thermally induced non-random sensor drift. The data presented here are from a prototype sensor module tested in the 0.3 M cryogenic tunnel and thermal equilibrium conditions in an environmental chamber which approximates the thermal environment (-173 degrees C to +60 degrees C) of the National Transonic Facility.

15. VIEW OF MODULE H, THE HIGH PRESSURE ASSEMBLY AREA. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. VIEW OF MODULE H, THE HIGH PRESSURE ASSEMBLY AREA. PROCESSES IN THIS MODULE OCCURRED UNDER HIGH PRESSURES AND TEMPERATURES. (5/70) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

Engaging students in research learning experiences through hydrology field excursions and projects

NASA Astrophysics Data System (ADS)

Ewen, T.; Seibert, J.

2014-12-01

One of the best ways to engage students and instill enthusiasm for hydrology is to expose them to hands-on learning. A focus on hydrology field research can be used to develop context-rich and active learning, and help solidify idealized learning where students are introduced to individual processes through textbook examples, often neglecting process interactions and an appreciation for the complexity of the system. We introduced a field course where hydrological measurement techniques are used to study processes such as snow hydrology and runoff generation, while also introducing students to field research and design of their own field project. In the field projects, students design a low-budget experiment with the aim of going through the different steps of a 'real' scientific project, from formulating the research question to presenting their results. In one of the field excursions, students make discharge measurements in several alpine streams with a salt tracer to better understand the spatial characteristics of an alpine catchment, where source waters originate and how they contribute to runoff generation. Soil moisture measurements taken by students in this field excursion were used to analyze spatial soil moisture patterns in the alpine catchment and subsequently used in a publication. Another field excursion repeats a published experiment, where preferential soil flow paths are studied using a tracer and compared to previously collected data. For each field excursion, observational data collected by the students is uploaded to an online database we developed, which also allows students to retrieve data from past excursions to further analyze and compare their data. At each of the field sites, weather stations were installed and a webviewer allows access to realtime data from data loggers, allowing students to explore how processes relate to climatic conditions. With in-house film expertise, these field excursions were also filmed and short virtual excursions were produced, which we plan to use in a large introductory course, exposing students to field research at an early stage.

Pressure tracking control of vehicle ABS using piezo valve modulator

NASA Astrophysics Data System (ADS)

Jeon, Juncheol; Choi, Seung-Bok

2011-03-01

This paper presents a wheel slip control for the ABS(anti-lock brake system) of a passenger vehicle using a controllable piezo valve modulator. The ABS is designed to optimize for braking effectiveness and good steerability. As a first step, the principal design parameters of the piezo valve and pressure modulator are appropriately determined by considering the braking pressure variation during the ABS operation. The proposed piezo valve consists of a flapper, pneumatic circuit and a piezostack actuator. In order to get wide control range of the pressure, the pressure modulator is desired. The modulator consists of a dual-type cylinder filled with different substances (fluid and gas) and a piston rod moving vertical axis to transmit the force. Subsequently, a quarter car wheel slip model is formulated and integrated with the governing equation of the piezo valve modulator. A sliding mode controller to achieve the desired slip rate is then designed and implemented. Braking control performances such as brake pressure and slip rate are evaluated via computer simulations.

Apollo-Lunar Orbital Rendezvous Technique

NASA Technical Reports Server (NTRS)

1963-01-01

The film shows artists rendition of the spacecrafts, boosters, and flight of the Apollo lunar missions. The Apollo spacecraft will consist of three modules: the manned Command Module; the Service Module, which contains propulsion systems; and the Lunar Excursion Module (LEM) to carry astronauts to the moon and back to the Command and Service Modules. The spacecraft will be launched via a three-stage Saturn booster. The first stage will provide 7.5 million pounds of thrust from five F-1 engines for liftoff and initial powered flight. The second stage will develop 1 million pounds of thrust from five J-2 engines to boost the spacecraft almost into Earth orbit. Immediately after ignition of the second stage, the Launch Escape System will be jettisoned. A single J-2 engine in the S4B stage will provide 200,000 pounds of thrust to place the spacecraft in an earth parking orbit. It also will be used to propel the spacecraft into a translunar trajectory, then it will separate from the Apollo Modules. Onboard propulsion systems will be used to insert the spacecraft into lunar orbit. Two astronauts will enter the LEM, which will separate from the command and service modules. The LEM will go into elliptical orbit and prepare for landing. The LEM will lift off of the Moon's surface to return to the Command and Service Modules, and most likely be left in lunar orbit. After leaving the Moon's orbit, and shortly before entering Earth's orbit, the Service Module will be ejected. The Command Module will be oriented for reentry into the Earth's atmosphere. A drogue parachute will deploy at approximately 50,000 feet, followed by the main parachute system for touchdown.

Electronically-Scanned Pressure Sensors

NASA Technical Reports Server (NTRS)

Coe, C. F.; Parra, G. T.; Kauffman, R. C.

1984-01-01

Sensors not pneumatically switched. Electronic pressure-transducer scanning system constructed in modular form. Pressure transducer modules and analog to digital converter module small enough to fit within cavities of average-sized wind-tunnel models. All switching done electronically. Temperature controlled environment maintained within sensor modules so accuracy maintained while ambient temperature varies.

Glucose excursions and glycaemic control during Ramadan fasting in diabetic patients: insights from continuous glucose monitoring (CGM).

PubMed

Lessan, N; Hannoun, Z; Hasan, H; Barakat, M T

2015-02-01

Ramadan fasting represents a major shift in meal timing and content for practicing Muslims. This study used continuous glucose monitoring (CGM) to assess changes in markers of glycaemic excursions during Ramadan fasting to investigate the short-term safety of this practice in different groups of patients with diabetes. A total of 63 subjects (56 with diabetes, seven healthy volunteers; 39 male, 24 female) had CGM performed during, before and after Ramadan fasting. Mean CGM curves were constructed for each group for these periods that were then used to calculate indicators of glucose control and excursions. Post hoc data analyses included comparisons of different medication categories (metformin/no medication, gliptin, sulphonylurea and insulin). Medication changes during Ramadan followed American Diabetes Association guidelines. Among patients with diabetes, there was a significant difference in mean CGM curve during Ramadan, with a slow fall during fasting hours followed by a rapid rise in glucose level after the sunset meal (iftar). The magnitude of this excursion was greatest in the insulin-treated group, followed by the sulphonylurea-treated group. Markers of control deteriorated in a small number (n=3) of patients. Overall, whether fasting or non-fasting, subjects showed no statistically significant changes in mean interstitial glucose (IG), mean amplitude of glycaemic excursion (MAGE), high and low blood glucose indices (HBGI/LBGI), and number of glucose excursions and rate of hypoglycaemia. The main change in glycaemic control with Ramadan fasting in patients with diabetes is in the pattern of excursions. Ramadan fasting caused neither overall deterioration nor improvement in the majority of patients with good baseline glucose control. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Comparison of Diaphragmatic Breathing Exercise, Volume and Flow Incentive Spirometry, on Diaphragm Excursion and Pulmonary Function in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial

PubMed Central

Anand, R.

2016-01-01

Objective. To evaluate the effects of diaphragmatic breathing exercises and flow and volume-oriented incentive spirometry on pulmonary function and diaphragm excursion in patients undergoing laparoscopic abdominal surgery. Methodology. We selected 260 patients posted for laparoscopic abdominal surgery and they were block randomization as follows: 65 patients performed diaphragmatic breathing exercises, 65 patients performed flow incentive spirometry, 65 patients performed volume incentive spirometry, and 65 patients participated as a control group. All of them underwent evaluation of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow Rate (PEFR), and diaphragm excursion measurement by ultrasonography before the operation and on the first and second postoperative days. With the level of significance set at p < 0.05. Results. Pulmonary function and diaphragm excursion showed a significant decrease on the first postoperative day in all four groups (p < 0.001) but was evident more in the control group than in the experimental groups. On the second postoperative day pulmonary function (Forced Vital Capacity) and diaphragm excursion were found to be better preserved in volume incentive spirometry and diaphragmatic breathing exercise group than in the flow incentive spirometry group and the control group. Pulmonary function (Forced Vital Capacity) and diaphragm excursion showed statistically significant differences between volume incentive spirometry and diaphragmatic breathing exercise group (p < 0.05) as compared to that flow incentive spirometry group and the control group. Conclusion. Volume incentive spirometry and diaphragmatic breathing exercise can be recommended as an intervention for all patients pre- and postoperatively, over flow-oriented incentive spirometry for the generation and sustenance of pulmonary function and diaphragm excursion in the management of laparoscopic abdominal surgery. PMID:27525116

Comparison of Diaphragmatic Breathing Exercise, Volume and Flow Incentive Spirometry, on Diaphragm Excursion and Pulmonary Function in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial.

PubMed

Alaparthi, Gopala Krishna; Augustine, Alfred Joseph; Anand, R; Mahale, Ajith

2016-01-01

Objective. To evaluate the effects of diaphragmatic breathing exercises and flow and volume-oriented incentive spirometry on pulmonary function and diaphragm excursion in patients undergoing laparoscopic abdominal surgery. Methodology. We selected 260 patients posted for laparoscopic abdominal surgery and they were block randomization as follows: 65 patients performed diaphragmatic breathing exercises, 65 patients performed flow incentive spirometry, 65 patients performed volume incentive spirometry, and 65 patients participated as a control group. All of them underwent evaluation of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow Rate (PEFR), and diaphragm excursion measurement by ultrasonography before the operation and on the first and second postoperative days. With the level of significance set at p < 0.05. Results. Pulmonary function and diaphragm excursion showed a significant decrease on the first postoperative day in all four groups (p < 0.001) but was evident more in the control group than in the experimental groups. On the second postoperative day pulmonary function (Forced Vital Capacity) and diaphragm excursion were found to be better preserved in volume incentive spirometry and diaphragmatic breathing exercise group than in the flow incentive spirometry group and the control group. Pulmonary function (Forced Vital Capacity) and diaphragm excursion showed statistically significant differences between volume incentive spirometry and diaphragmatic breathing exercise group (p < 0.05) as compared to that flow incentive spirometry group and the control group. Conclusion. Volume incentive spirometry and diaphragmatic breathing exercise can be recommended as an intervention for all patients pre- and postoperatively, over flow-oriented incentive spirometry for the generation and sustenance of pulmonary function and diaphragm excursion in the management of laparoscopic abdominal surgery.

A carbon isotopic and sedimentological record of the latest Devonian (Famennian) from the Western U.S. and Germany

USGS Publications Warehouse

Myrow, P.M.; Strauss, J.V.; Creveling, J.R.; Sicard, K.R.; Ripperdan, R.; Sandberg, C.A.; Hartenfels, S.

2011-01-01

New carbon isotopic data from upper Famennian deposits in the western United States reveal two previously unrecognized major positive isotopic excursions. The first is an abrupt ~. 3??? positive excursion, herein referred to as ALFIE (A Late Famennian Isotopic Excursion), recorded in two sections of the Pinyon Peak Limestone of north-central Utah. Integration of detailed chemostratigraphic and biostratigraphic data suggests that ALFIE is the Laurentian record of the Dasberg Event, which has been linked to transgression in Europe and Morocco. Sedimentological data from the Chaffee Group of western Colorado also record transgression at a similar biostratigraphic position, with a shift from restricted to open-marine lithofacies. ALFIE is not evident in chemostratigraphic data from age-equivalent strata in Germany studied herein and in southern Europe, either because it is a uniquely North American phenomenon, or because the German sections are too condensed relative to those in Laurentia. A second positive carbon isotopic excursion from the upper Chaffee Group of Colorado is recorded in transgressive strata deposited directly above a previously unrecognized paleokarst interval. The age of this excursion, and the duration of the associated paleokarst hiatus, are not well constrained, although the events occurred sometime after the Late Famennian Middle expansa Zone. The high positive values recorded in this excursion are consistent with those associated with the youngest Famennian Middle to Late praesulcata Hangenberg Isotopic Excursion in Europe, the isotopic expression of the Hangenberg Event, which included mass extinction, widespread black shale deposition, and a glacio-eustatic fall and rise. If correct, this would considerably revise the age of the Upper Chaffee Group strata of western Colorado. ?? 2011 Elsevier B.V.

Exploring the Angstrom Excursion of Au Nanoparticles Excited away from a Metal Surface by an Impulsive Acoustic Perturbation.

PubMed

Kim, Ji-Wan; Kovalenko, Oleksandr; Liu, Yu; Bigot, Jean-Yves

2016-12-27

We report the anharmonic angstrom dynamics of self-assembled Au nanoparticles (Au:NPs) away from a nickel surface on top of which they are coupled by their near-field interaction. The deformation and the oscillatory excursion away from the surface are induced by picosecond acoustic pulses and probed at the surface plasmon resonance with femtosecond laser pulses. The overall dynamics are due to an efficient transfer of translational momentum from the Ni surface to the Au:NPs, therefore avoiding usual thermal effects and energy redistribution among the electronic states. Two modes are clearly revealed by the oscillatory shift of the Au:NPs surface plasmon resonance-the quadrupole deformation mode due to the transient ellipsoid shape and the excursion mode when the Au:NPs bounce away from the surface. We find that, contrary to the quadrupole mode, the excursion mode is sensitive to the distance between Au:NPs and Ni. Importantly, the excursion dynamics display a nonsinusoidal motion that cannot be explained by a standard harmonic potential model. A detailed modeling of the dynamics using a Hamaker-type Lennard-Jones potential between two media is performed, showing that each Au:NPs coherently evolves in a nearly one-dimensional anharmonic potential with a total excursion of ∼1 Å. This excursion induces a shift of the surface plasmon resonance detectable because of the strong near-field interaction. This general method of observing the spatiotemporal dynamics with angstrom and picosecond resolutions can be directly transposed to many nanostructures or biosystems to reveal the interaction and contact mechanism with their surrounding medium while remaining in their fundamental electronic states.

Duration of and decoupling between carbon isotope excursions during the end-Triassic mass extinction and Central Atlantic Magmatic Province emplacement

NASA Astrophysics Data System (ADS)

Yager, Joyce A.; West, A. Joshua; Corsetti, Frank A.; Berelson, William M.; Rollins, Nick E.; Rosas, Silvia; Bottjer, David J.

2017-09-01

Changes in δ13Ccarb and δ13Corg from marine strata occur globally in association with the end-Triassic mass extinction and the emplacement of the Central Atlantic Magmatic Province (CAMP) during the break up of Pangea. As is typical in deep time, the timing and duration of these isotopic excursions has remained elusive, hampering attempts to link carbon cycle perturbations to specific processes. Here, we report δ13Ccarb and δ13Corg from Late Triassic and Early Jurassic strata near Levanto, Peru, where intercalated dated ash beds permit temporal calibration of the carbon isotope record. Both δ13Ccarb and δ13Corg exhibit a broad positive excursion through the latest Triassic into the earliest Jurassic. The first order positive excursion in δ13Corg is interrupted by a negative shift noted in many sections around the world coincident with the extinction horizon. Our data indicate that the negative excursion lasts 85 ± 25 kyrs, longer than inferred by previous studies based on cyclostratigraphy. A 260 ± 80 kyr positive δ13Corg shift follows, during which the first Jurassic ammonites appear. The overall excursion culminates in a return to pre-perturbation carbon isotopic values over the next 1090 ± 70 kyrs. Via chronologic, isotopic, and biostratigraphic correlation to other successions, we find that δ13Ccarb and δ13Corg return to pre-perturbation values as CAMP volcanism ceases and in association with the recovery of pelagic and benthic biota. However, the initiation of the carbon isotope excursion at Levanto predates the well-dated CAMP sills from North America, indicating that CAMP may have started earlier than thought based on these exposures, or that the onset of carbon cycle perturbations was not related to CAMP.

Fission yield and criticality excursion code

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

Blanchard, A.

2000-06-30

The ANSI/ANS 8.3 standard allows a maximum yield not to exceed 2 x 10 fissions to calculate requiring the alarm system to be effective. It is common practice to use this allowance or to develop some other yield based on past criticality accident history or excursion experiments. The literature on the subject of yields discusses maximum yields larger and somewhat smaller than the ANS 8.3 permissive value. The ability to model criticality excursions and vary the various parameters to determine a credible maximum yield for operational specific cases has been available for some time but is not in common usemore » by criticality safety specialists. The topic of yields for various solution, metal, oxide powders, etc. in various geometry's and containers has been published by laboratory specialists or university staff and students for many decades but have not been available to practitioners. The need for best-estimate calculations of fission yields with a well-validated criticality excursion code has long been recognized. But no coordinated effort has been made so far to develop a generalized and well-validated excursion code for different types of systems. In this paper, the current practices to estimate fission yields are summarized along with its shortcomings for the 12-Rad zone (at SRS) and Criticality Alarm System (CAS) calculations. Finally the need for a user-friendly excursion code is reemphasized.« less

Cryogenic Pressure Calibrator for Wide Temperature Electronically Scanned (ESP) Pressure Modules

NASA Technical Reports Server (NTRS)

Faulcon, Nettie D.

2001-01-01

Electronically scanned pressure (ESP) modules have been developed that can operate in ambient and in cryogenic environments, particularly Langley's National Transonic Facility (NTF). Because they can operate directly in a cryogenic environment, their use eliminates many of the operational problems associated with using conventional modules at low temperatures. To ensure the accuracy of these new instruments, calibration was conducted in a laboratory simulating the environmental conditions of NTF. This paper discusses the calibration process by means of the simulation laboratory, the system inputs and outputs and the analysis of the calibration data. Calibration results of module M4, a wide temperature ESP module with 16 ports and a pressure range of +/- 4 psid are given.

Scaphoid tuberosity excursion is minimized during a dart-throwing motion: A biomechanical study.

PubMed

Werner, Frederick W; Sutton, Levi G; Basu, Niladri; Short, Walter H; Moritomo, Hisao; St-Amand, Hugo

2016-01-01

The purpose of this study was to determine whether the excursion of the scaphoid tuberosity and therefore scaphoid motion is minimized during a dart-throwing motion. Scaphoid tuberosity excursion was studied as an indicator of scaphoid motion in 29 cadaver wrists as they were moved through wrist flexion-extension, radioulnar deviation, and a dart-throwing motion. Study results demonstrate that excursion was significantly less during the dart-throwing motion than during either wrist flexion-extension or radioulnar deviation. If the goal of early wrist motion after carpal ligament or distal radius injury and reconstruction is to minimize loading of the healing structures, a wrist motion in which scaphoid motion is minimal should reduce length changes in associated ligamentous structures. Therefore, during rehabilitation, if a patient uses a dart-throwing motion that minimizes his or her scaphoid tuberosity excursion, there should be minimal changes in ligament loading while still allowing wrist motion. Bench research, biomechanics, and cross-sectional. Not applicable. The study was laboratory based. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Compensation for large thorax excursions in EIT imaging.

PubMed

Schullcke, B; Krueger-Ziolek, S; Gong, B; Mueller-Lisse, U; Moeller, K

2016-09-01

Besides the application of EIT in the intensive care unit it has recently also been used in spontaneously breathing patients suffering from asthma bronchiole, cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD). In these cases large thorax excursions during deep inspiration, e.g. during lung function testing, lead to artifacts in the reconstructed images. In this paper we introduce a new approach to compensate for image artifacts resulting from excursion induced changes in boundary voltages. It is shown in a simulation study that boundary voltage change due to thorax excursion on a homogeneous model can be used to modify the measured voltages and thus reduce the impact of thorax excursion on the reconstructed images. The applicability of the method on human subjects is demonstrated utilizing a motion-tracking-system. The proposed technique leads to fewer artifacts in the reconstructed images and improves image quality without substantial increase in computational effort, making the approach suitable for real-time imaging of lung ventilation. This might help to establish EIT as a supplemental tool for lung function tests in spontaneously breathing patients to support clinicians in diagnosis and monitoring of disease progression.

22. WILEY CITY LINE BICENTENNIAL EXCURSION TROLLEY NEAR CONGDON ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

22. WILEY CITY LINE - BICENTENNIAL EXCURSION TROLLEY NEAR CONGDON CASTLE - Yakima Valley Transportation Company Interurban Railroad, Connecting towns of Yakima, Selah & Wiley City, Yakima, Yakima County, WA

Health Instruction Packages: How to Take a Blood Pressure.

ERIC Educational Resources Information Center

Lancaster, Carolyn; And Others

Text, illustrations, and exercises are utilized in these four learning modules to teach dental hygiene students, nursing students, and the general public how to measure blood pressure. The first module, "Can You Take a Blood Pressure?" by Carolyn Lancaster, defines blood pressure, distinguishes between systolic and diastolic pressure and…

KENNEDY SPACE CENTER, FLA. - An overview of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

NASA Image and Video Library

2003-06-06

KENNEDY SPACE CENTER, FLA. - An overview of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

KENNEDY SPACE CENTER, FLA. - A view of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

NASA Image and Video Library

2003-06-06

KENNEDY SPACE CENTER, FLA. - A view of the Space Station Processing Facility shows workstands and ISS elements. The most recent additions are the Japanese Experiment Module (JEM)’s pressurized module and the Italian-built Node 2. The pressurized module is the first element of the JEM, Japan’s primary contribution to the Space Station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. Node 2 will be installed on the end of the U.S. Lab and provides attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS.

Possible link of sudden onset and short-time periodic pulsation of polar mesosphere summer echoes to ULF Pc5 geomagnetic pulsations and solar wind dynamic pressure enhancement

NASA Astrophysics Data System (ADS)

Lee, Y.; Kirkwood, S.; Kwak, Y. S.

2016-12-01

The EISCAT VHF incoherent scatter radar in Tromsö, Norway, makes occasional observations of electron densities and Polar Mesosphere Summer Echoes, in the summer polar D-region ionosphere. In one of those datasets, pulsating polar mesospheric summer echoes (PMSE) are observed, with periodicities in the ultra-low frequency (ULF) Pc5 band (1.6-6.7 mHz), following an abrupt increase of the radar reflectivity when a geomagnetic field excursion is started, in turn linked to dynamic pressure (Pdyn) enhancement in the solar wind. At the excursion of the magnetic field, at auroral altitudes of 90 km and above, electron density is abruptly enhanced, followed by a series of short-lived peaks, superimposed on an enhanced level. The short-lived peaks are likely a signature of transient Pc5 geomagnetic pulsations and associated energetic electron precipitation from pitch-angle scattering into the loss cone in the magnetosphere. At the same time, at altitudes around 80-90 km, a sharp increase of PMSE reflectivity occurs, 100 times greater than the increase of electron density, and is followed by pulsating PMSE reflectivity with periodicities in the Pc5 band, increasing and decreasing in magnitude during the course of the next hour. The increase of the pulsation magnitude may be attributed to an increase of high-energy electron precipitation flux ( >30 keV) penetrating to at least the height of maximum PMSE reflectivity. This study suggests that Pc5 pulsation bursts in both magnetic field and high energy electron precipitation could play a crucial role in producing PMSE fluctuations on minute-to-minute time scales.

Ultra-High Temperature Steam Corrosion of Complex Silicates for Nuclear Applications: A Computational Study

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

Rashkeev, Sergey N.; Glazoff, Michael V.; Tokuhiro, Akira

2014-01-01

Stability of materials under extreme conditions is an important issue for safety of nuclear reactors. Presently, silicon carbide (SiC) is being studied as a cladding material candidate for fuel rods in boiling-water and pressurized water-cooled reactors (BWRs and PWRs) that would substitute or modify traditional zircaloy materials. The rate of corrosion of the SiC ceramics in hot vapor environment (up to 2200 degrees C) simulating emergency conditions of light water reactor (LWR) depends on many environmental factors such as pressure, temperature, viscosity, and surface quality. Using the paralinear oxidation theory developed for ceramics in the combustion reactor environment, we estimatedmore » the corrosion rate of SiC ceramics under the conditions representing a significant power excursion in a LWR. It was established that a significant time – at least 100 h – is required for a typical SiC braiding to significantly degrade even in the most aggressive vapor environment (with temperatures up to 2200 °C) which is possible in a LWR at emergency condition. This provides evidence in favor of using the SiC coatings/braidings for additional protection of nuclear reactor rods against off-normal material degradation during power excursions or LOCA incidents. Additionally, we discuss possibilities of using other silica based ceramics in order to find materials with even higher corrosion resistance than SiC. In particular, we found that zircon (ZrSiO4) is also a very promising material for nuclear applications. Thermodynamic and first-principles atomic-scale calculations provide evidence of zircon thermodynamic stability in aggressive environments at least up to 1535 degrees C.« less

Industrial Code Development

NASA Technical Reports Server (NTRS)

Shapiro, Wilbur

1991-01-01

The industrial codes will consist of modules of 2-D and simplified 2-D or 1-D codes, intended for expeditious parametric studies, analysis, and design of a wide variety of seals. Integration into a unified system is accomplished by the industrial Knowledge Based System (KBS), which will also provide user friendly interaction, contact sensitive and hypertext help, design guidance, and an expandable database. The types of analysis to be included with the industrial codes are interfacial performance (leakage, load, stiffness, friction losses, etc.), thermoelastic distortions, and dynamic response to rotor excursions. The first three codes to be completed and which are presently being incorporated into the KBS are the incompressible cylindrical code, ICYL, and the compressible cylindrical code, GCYL.

Brownian excursions on combs

NASA Astrophysics Data System (ADS)

Dean, David S.; Jansons, Kalvis M.

1993-03-01

In this paper we use techniques from Ito excursion theory to analyze Brownian motion on generalized combs. Ito excursion theory is a little-known area of probability theory and we therefore present a brief introduction for the uninitiated. A general method for analyzing transport along the backbone of the comb is demonstrated and the specific case of a comb whose teeth are scaling branching trees is examined. We then present a recursive method for evaluating the distribution of the first passage times on hierarchical combs.

Nonstationary envelope process and first excursion probability.

NASA Technical Reports Server (NTRS)

Yang, J.-N.

1972-01-01

The definition of stationary random envelope proposed by Cramer and Leadbetter, is extended to the envelope of nonstationary random process possessing evolutionary power spectral densities. The density function, the joint density function, the moment function, and the crossing rate of a level of the nonstationary envelope process are derived. Based on the envelope statistics, approximate solutions to the first excursion probability of nonstationary random processes are obtained. In particular, applications of the first excursion probability to the earthquake engineering problems are demonstrated in detail.

Sulfur cycling in plays an important role in the development of Ocean Anoxic Events

NASA Astrophysics Data System (ADS)

Gomes, M. L.; Raven, M. R.; Fike, D. A.; Gill, B. C.; Johnston, D. T.

2017-12-01

Ocean Anoxic Events (OAEs) are major carbon cycle perturbations marked by enhanced organic carbon deposition in the marine realm and carbon isotope excursions in organic and inorganic carbon. Although not as severe as the "big five" mass extinctions, OAEs had dire consequences for marine ecosystems and thus influenced Mesozoic evolutionary patterns. Sulfur cycle reconstructions provide insight into the biogeochemical processes that played a role in the development of OAEs because the sulfur cycle is linked with the carbon and oxygen cycles. We present sulfur and oxygen isotope records from carbonate-associated sulfate from the Toarcian OAE that documents a positive sulfate-oxygen isotope excursion of +6‰, which is similar to the magnitude of the positive sulfur isotope excursion documented at the same site and other globally distributed sites. This high-resolution record allows us to explore temporal variability in the onset of the isotopic excursions: the onset of the positive sulfate-oxygen isotope excursion occurs at the same stratigraphic interval as the onset of the positive carbon isotope excursion and both precede the onset of the positive sulfate-sulfur isotope excursion. Because oxygen is rapidly recycled during oxidative sulfur cycling, changes in oxidative sulfur cycling affect oxygen isotope values of sulfate without impacting sulfur isotope values. Thus, the early onset of the sulfate-oxygen isotope excursion implies a change in oxidative sulfur cycling, which is likely due to a shoaling of the zone of sulfate reduction. We explore the consequences of sulfate reduction zone shoaling for organic carbon preservation. Specifically, the sulfurization of organic matter, which makes organic matter less susceptible to degradation, occurs more rapidly when the top of the zone of sulfate reduction is near or above the sediment water interface. Therefore, we suggest that the shoaling of the sulfate reduction zone locally changed pathways of oxidative sulfur cycling and enhanced organic carbon preservation. Given synchronous changes in similar, globally-distributed depositional environments, this impacted the global biogeochemical cycles of oxygen, carbon, and nutrients in ways that sustained decreased oxygen availability and influenced extinction patterns of marine organisms.

Multiple Exposure of Rendezvous Docking Simulator - Gemini Program

NASA Image and Video Library

1964-02-07

Multiple exposure of Rendezvous Docking Simulator. Francis B. Smith, described the simulator as follows: The rendezvous and docking operation of the Gemini spacecraft with the Agena and of the Apollo Command Module with the Lunar Excursion Module have been the subject of simulator studies for several years. This figure illustrates the Gemini-Agena rendezvous docking simulator at Langley. The Gemini spacecraft was supported in a gimbal system by an overhead crane and gantry arrangement which provided 6 degrees of freedom - roll, pitch, yaw, and translation in any direction - all controllable by the astronaut in the spacecraft. Here again the controls fed into a computer which in turn provided an input to the servos driving the spacecraft so that it responded to control motions in a manner which accurately simulated the Gemini spacecraft. -- Published in Barton C. Hacker and James M. Grimwood, On the Shoulders of Titans: A History of Project Gemini, NASA SP-4203 Francis B. Smith, Simulators for Manned Space Research, Paper presented at the 1966 IEEE International convention, March 21-25, 1966.

Operating characteristics of a 0.87 kW-hr flywheel energy storage module

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Scibbe, H. W.; Parker, R. D.; Zaretsky, E. V.

1985-01-01

Discussion is given of the design and loss characteristics of 0.87 kW-hr (peak) flywheel energy storage module suitable for aerospace and automotive applications. The maraging steel flywheel rotor, a 46-cm- (18-in-) diameter, 58-kg (128-lb) tapered disk, delivers 0.65 kW-hr of usable energy between operating speeds of 10,000 and 20,000 rpm. The rotor is supported by 20- and 25-mm bore diameter, deep-groove ball bearings, lubricated by a self-replenishing wick type lubrication system. To reduce aerodynamic losses, the rotor housing was evacuated to vacuum levels from 40 to 200 millitorr. Dynamic rotor instabilities uncovered during testing necessitated the use of an elastometric-bearing damper to limit shaft excursions. Spindown losses from bearing, seal, and aerodynamic drag at 50 millitorr typically ranged from 64 to 193 W at 10,000 and 20,000 rpm, respectively. Discharge efficiency of the flywheel system exceeded 96 percent at torque levels greater than 21 percent of rated torque.

An Excursion in Applied Mathematics.

ERIC Educational Resources Information Center

von Kaenel, Pierre A.

1981-01-01

An excursion in applied mathematics is detailed in a lesson deemed well-suited for the high school student or undergraduate. The problem focuses on an experimental missile guidance system simulated in the laboratory. (MP)

Instant axis of rotation of L4-5 motion segment--a biomechanical study on cadaver lumbar spine.

PubMed

Sengupta, Dilip K; Demetropoulos, Constantine K; Herkowitz, Harry N

2011-06-01

The instant axis of rotation (IAR) is an important kinematic property to characterise of lumbar spine motion. The goal of this biomechanical study on cadaver lumbar spine was to determine the excursion of the IAR for flexion (FE), lateral bending (LB) and axial rotation (AR) motion at L4-5 segment. Ten cadaver lumbar spine specimens were tested in a 6 degrees-of-freedom spine tester with continuous clyclical loading using pure moment and follower pre-load, to produce physiological motion. The specimens were x-rayed and CT scanned prior to testing to identify marker position. Continuous motion tracking was done by Optotrak motion capture device. A continuous tracking of the IAR excursion was calculated from the continuous motions capturedata using a computer programme. IAR translates forward in flexion and backwards in extension with mean excursion of 26.5 mm (+/- 5.6 SD). During LB motion, IAR translates laterally in the same direction, and the mean excursion was 15.35 mm (+/- 8.75 SD). During axial rotation the IAR translates in the horizontal plane in a semicircular arc, around the centre of the vertebral body, but the IAR translates in the opposite direction of rotation. The IAR excursion was faster and larger during neutral zone motion in FE and LB, but uniform for AR motion. This is the first published data on the continuous excursion of IAR of a lumbar motion segment. The methodology is accurate and precise, but not practicable for in vivo testing.

ELM suppression in helium plasmas with 3D magnetic fields

DOE PAGES

Evans, T. E.; Loarte, A.; Orlov, D. M.; ...

2017-06-21

Experiments in DIII-D, using non-axisymmetric magnetic perturbation fields in high-purity low toroidal rotation, 4He plasmas have resulted in Type-I edge localized mode (ELM) suppression and mitigation. Suppression is obtained in plasmas with zero net input torque near the L–H power threshold using either electron cyclotron resonant heating (ECRH) or balanced co- and counter-I p neutral beam injection (NBI) resulting in conditions equivalent to those expected in ITER's non-active operating phase. In low-power ECRH H-modes, periods with uncontrolled density and impurity radiation excursions are prevented by applying n = 3 non-axisymmetric magnetic perturbation fields. ELM suppression results from a reduction andmore » an outward shift of the electron pressure gradient peak compared to that in the high-power ELMing phase. Here, the change in the electron pressure gradient peak is primarily due to a drop in the pedestal temperature rather than the pedestal density.« less

ELM suppression in helium plasmas with 3D magnetic fields

NASA Astrophysics Data System (ADS)

Evans, T. E.; Loarte, A.; Orlov, D. M.; Grierson, B. A.; Knölker, M. M.; Lyons, B. C.; Cui, L.; Gohil, P.; Groebner, R. J.; Moyer, R. A.; Nazikian, R.; Osborne, T. H.; Unterberg, E. A.

2017-08-01

Experiments in DIII-D, using non-axisymmetric magnetic perturbation fields in high-purity low toroidal rotation, 4He plasmas have resulted in Type-I edge localized mode (ELM) suppression and mitigation. Suppression is obtained in plasmas with zero net input torque near the L-H power threshold using either electron cyclotron resonant heating (ECRH) or balanced co- and counter-I p neutral beam injection (NBI) resulting in conditions equivalent to those expected in ITER’s non-active operating phase. In low-power ECRH H-modes, periods with uncontrolled density and impurity radiation excursions are prevented by applying n  =  3 non-axisymmetric magnetic perturbation fields. ELM suppression results from a reduction and an outward shift of the electron pressure gradient peak compared to that in the high-power ELMing phase. The change in the electron pressure gradient peak is primarily due to a drop in the pedestal temperature rather than the pedestal density.

Glycaemic variability in patients with severe sepsis or septic shock admitted to an Intensive Care Unit.

PubMed

Silveira, L M; Basile-Filho, A; Nicolini, E A; Dessotte, C A M; Aguiar, G C S; Stabile, A M

2017-08-01

Sepsis is associated with morbidity and mortality, which implies high costs to the global health system. Metabolic alterations that increase glycaemia and glycaemic variability occur during sepsis. To verify mean body glucose levels and glycaemic variability in Intensive Care Unit (ICU) patients with severe sepsis or septic shock. Retrospective and exploratory study that involved collection of patients' sociodemographic and clinical data and calculation of severity scores. Glycaemia measurements helped to determine glycaemic variability through standard deviation and mean amplitude of glycaemic excursions. Analysis of 116 medical charts and 6730 glycaemia measurements revealed that the majority of patients were male and aged over 60 years. Surgical treatment was the main reason for ICU admission. High blood pressure and diabetes mellitus were the most usual comorbidities. Patients that died during the ICU stay presented the highest SOFA scores and mean glycaemia; they also experienced more hypoglycaemia events. Patients with diabetes had higher mean glycaemia, evaluated through standard deviation and mean amplitude of glycaemia excursions. Organic impairment at ICU admission may underlie glycaemic variability and lead to a less favourable outcome. High glycaemic variability in patients with diabetes indicates that monitoring of these individuals is crucial to ensure better outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrogen mobility in transition zone silicates

NASA Astrophysics Data System (ADS)

Caracas, Razvan; Panero, Wendy R.

2017-12-01

We study the hydrogen mobility in ringwoodite and wadsleyite considering multiple charge-balanced defects, including Mg < = > 2H, Si < = > Mg + 2H, and the hydrogarnet defect, Si < = > 4H, using molecular dynamics simulations based on the density functional theory at transition zone pressures and temperatures between 1500 and 2500 K. We determine the diffusion coefficients and study in detail the mechanism of hydrogen mobility during lengthy simulations. Our results show that temperature, water concentration, and defect mechanism have a significant effect on mobility. We find that the fastest diffusion is for the Mg < = > 2H defect, while H is more mobile when incorporated as Si < = > Mg + 2H than as hydrogarnet defects. The computed diffusivities for ringwoodite are larger than for wadsleyite: at 2000 K, diffusivity is 1.13 × 10-09 m2/s for ringwoodite compared to 0.93 × 10-09 m2/s for wadsleyite. In general, the hydrogen atoms spend on the order of tens of picoseconds or more trapped in or around the vacancy sites with net migration between sites over timescales of tens of femtoseconds. At 2500 K, some of these hydrogen excursions take place over several angstroms, while at 2000 K, they do not always result in net diffusion. At 1500 K, most of the defects fail to make excursions from their defect sites resulting in diffusion.

Method and Apparatus for Characterizing Pressure Sensors using Modulated Light Beam Pressure

NASA Technical Reports Server (NTRS)

Youngquist, Robert C. (Inventor)

2003-01-01

Embodiments of apparatuses and methods are provided that use light sources instead of sound sources for characterizing and calibrating sensors for measuring small pressures to mitigate many of the problems with using sound sources. In one embodiment an apparatus has a light source for directing a beam of light on a sensing surface of a pressure sensor for exerting a force on the sensing surface. The pressure sensor generates an electrical signal indicative of the force exerted on the sensing surface. A modulator modulates the beam of light. A signal processor is electrically coupled to the pressure sensor for receiving the electrical signal.

Space transfer concepts and analysis for exploration missions. Implementation plan and element description document (draft final). Volume 6: Lunar systems

NASA Technical Reports Server (NTRS)

1991-01-01

NASA's two Office of Space Flight (Code M) Space Transfer Vehicle (STV) contractors supported development of Space Exploration Initiative (SEI) lunar transportation concepts. This work treated lunar SEI missions as the far end of a more near-term STV program, most of whose missions were satellite delivery and servicing requirements derived from Civil Needs Data Base (CNDB) projections. Space Transfer Concepts and Analysis for Exploration Missions (STCAEM) began to address the complete design of a lunar transportation system. The following challenges were addressed: (1) the geometry of aerobraking; (2) accommodation of mixed payloads; (3) cryogenic propellant transfer in Low Lunar Orbit (LLO); (4) fully re-usable design; and (5) growth capability. The leveled requirements, derived requirements, and assumptions applied to the lunar transportation system design are discussed. The mission operations section includes data on mission analysis studies and performance parametrics as well as the operating modes and performance evaluations which include the STCAEM recommendations. Element descriptions for the lunar transportation family included are a listing of the lunar transfer vehicle/lunar excursion vehicle (LTV/LEV) components; trade studies and mass analyses of the transfer and excursion modules; advanced crew recovery vehicle (ACRV) (modified crew recovery vehicle (MCRV)) modifications required to fulfill lunar operations; the aerobrake shape and L/D to be used; and some costing methods and results. Commonality and evolution issues are also discussed.

Potential Cislunar and Interplanetary Proving Ground Excursion Trajectory Concepts

NASA Technical Reports Server (NTRS)

McGuire, Melissa L.; Strange, Nathan J.; Burke, Laura M.; MacDonald, Mark A.; McElrath, Timothy P.; Landau, Damon F.; Lantoine, Gregory; Hack, Kurt J.; Lopez, Pedro

2016-01-01

NASA has been investigating potential translunar excursion concepts to take place in the 2020s that would be used to test and demonstrate long duration life support and other systems needed for eventual Mars missions in the 2030s. These potential trajectory concepts could be conducted in the proving ground, a region of cislunar and near-Earth interplanetary space where international space agencies could cooperate to develop the technologies needed for interplanetary spaceflight. Enabled by high power Solar Electric Propulsion (SEP) technologies, the excursion trajectory concepts studied are grouped into three classes of increasing distance from the Earth and increasing technical difficulty: the first class of excursion trajectory concepts would represent a 90-120 day round trip trajectory with abort to Earth options throughout the entire length, the second class would be a 180-210 day round trip trajectory with periods in which aborts would not be available, and the third would be a 300-400 day round trip trajectory without aborts for most of the length of the trip. This paper provides a top-level summary of the trajectory and mission design of representative example missions of these three classes of excursion trajectory concepts.

The Carnian (Late Triassic) carbon isotope excursion: new insights from the terrestrial realm

NASA Astrophysics Data System (ADS)

Miller, Charlotte; Kürschner, Wolfram; Peterse, Francien; Baranyi, Viktoria; Reichart, Gert-Jan

2016-04-01

The geological record contains evidence for numerous pronounced perturbations in the global carbon cycle, some of which are associated with eruptions from large igneous provinces (LIP), and consequently, ocean acidification and mass extinction. In the Carnian (Late Triassic), evidence from sedimentology and fossil pollen points to a significant change in climate, resulting in biotic turnover: during a period termed the 'Carnian Pluvial Event' (CPE). Additionally, during the Carnian, large volumes of flood basalts were erupted from the Wrangellia LIP (western North America). Evidence from the marine realm suggests a fundamental relationship between the CPE, a global 'wet' period, and the injection of light carbon into the atmosphere from the LIP. Here we provide the first evidence from the terrestrial realm of a significant negative δ13C excursion through the CPE recorded in the sedimentary archive of the Wiscombe Park Borehole, Devon (UK). Both total organic matter and plant leaf waxes reflect a gradual carbon isotope excursion of ~-5‰ during this time interval. Our data provides evidence for the global nature of this isotope excursion, supporting the hypothesis that the excursion was likely the result of an injection of light carbon into the atmosphere from the Wrangellia LIP.

Geometrical effects of conventional and digital prosthodontic planning wax-ups on lateral occlusal contact number, contact area, and steepness.

PubMed

Abduo, Jaafar

2017-01-01

This study evaluated and compared the effect of conventional and digital wax-ups on three lateral occlusion variables: contact number, contact area, and steepness. Dental casts of 10 patients with Angle Class I relationship were included in the study. All patients required fixed prosthodontic treatment that would affect lateral occlusion. The casts of all patients received conventional and digital wax-ups. For pretreatment, conventional wax-up, and digital wax-up casts, contact number, contact area, and occlusion steepness were measured at four lateral positions, that is, at excursions of 0.5, 1.0, 2.0, and 3.0 mm from maximal intercuspation. Lateral occlusion scheme variables were affected by use of diagnostic wax-ups. For all types of casts, contact number decreased as excursion increased. The two types of wax-ups had similar contact number patterns, and contact number was significantly greater for these casts than for pretreatment casts in the earlier stages of excursion. Similarly, contact area gradually decreased with increasing excursion in the pretreatment and conventional and digital wax-up casts. There was only a minimal decrease in occlusion steepness as excursion increased. However, lateral occlusion was generally steeper for digital wax-up casts.

Ion transport membrane module and vessel system

DOEpatents

Stein, VanEric Edward; Carolan, Michael Francis; Chen, Christopher M.; Armstrong, Phillip Andrew; Wahle, Harold W.; Ohrn, Theodore R.; Kneidel, Kurt E.; Rackers, Keith Gerard; Blake, James Erik; Nataraj, Shankar; van Doorn, Rene Hendrik Elias; Wilson, Merrill Anderson

2007-02-20

An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel. The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

Ion transport membrane module and vessel system

DOEpatents

Stein, VanEric Edward [Allentown, PA; Carolan, Michael Francis [Allentown, PA; Chen, Christopher M [Allentown, PA; Armstrong, Phillip Andrew [Orefield, PA; Wahle, Harold W [North Canton, OH; Ohrn, Theodore R [Alliance, OH; Kneidel, Kurt E [Alliance, OH; Rackers, Keith Gerard [Louisville, OH; Blake, James Erik [Uniontown, OH; Nataraj, Shankar [Allentown, PA; Van Doorn, Rene Hendrik Elias; Wilson, Merrill Anderson [West Jordan, UT

2012-02-14

An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel. The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

Ion transport membrane module and vessel system

DOEpatents

Stein, VanEric Edward [Allentown, PA; Carolan, Michael Francis [Allentown, PA; Chen, Christopher M [Allentown, PA; Armstrong, Phillip Andrew [Orefield, PA; Wahle, Harold W [North Canton, OH; Ohrn, Theodore R [Alliance, OH; Kneidel, Kurt E [Alliance, OH; Rackers, Keith Gerard [Louisville, OH; Blake, James Erik [Uniontown, OH; Nataraj, Shankar [Allentown, PA; van Doorn, Rene Hendrik Elias; Wilson, Merrill Anderson [West Jordan, UT

2008-02-26

An ion transport membrane system comprising (a) a pressure vessel having an interior, an exterior, an inlet, and an outlet; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein any inlet and any outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; and (c) one or more gas manifolds in flow communication with interior regions of the membrane modules and with the exterior of the pressure vessel.The ion transport membrane system may be utilized in a gas separation device to recover oxygen from an oxygen-containing gas or as an oxidation reactor to oxidize compounds in a feed gas stream by oxygen permeated through the mixed metal oxide ceramic material of the membrane modules.

High Temperature Performance Evaluation of a Compliant Foil Seal

NASA Technical Reports Server (NTRS)

Salehi, Mohsen; Heshmat, Hooshang; Walton, James F., II

2001-01-01

The key points to be gleaned from the effort reported herein are that the CFS (Compliant Foil Seal) has been demonstrated in conjunction with a foil bearing in a small gas turbine simulator at temperatures as high as 1000 F and outperformed a comparable brush seal. Having demonstrated the feasibility of the CFS, it would appear that this new seal design has application potential in a wide range of machines. What remains is to demonstrate performance at higher pressure ratios, consistent performance at large rotor excursions and the ability to manufacture the seal in much larger sizes exceeding by an order of magnitude that which has been tested to date.

Oxygen consumption measurements during continual centrifugation of mice.

NASA Technical Reports Server (NTRS)

Fethke, W.; Cook, K. M.; Porter, S. M.; Wunder, C. C.

1973-01-01

A simple method is described for measurement of metabolism of conscious, unrestrained animals, during chronic centrifugation or other conditions of isolation (23.75 hr/day) from the investigators in an essentially normal atmospheric environment for as long as seven days. This involves telemetry of pressure changes in a metabolic chamber. At 7 G's, increased O2 intake lasting two to seven days and a decreased excursion of the day-night difference were measured for male white mice with less effect or even an opposite effect at lower fields. Base-line measurements of metabolic rate per mouse are less affected by animal size than expected from the surface area law.

Toward an orbital chronology for the early Aptian Oceanic Anoxic Event (OAE1a, ~ 120 Ma)

NASA Astrophysics Data System (ADS)

Li, Yong-Xiang; Bralower, Timothy J.; Montañez, Isabel P.; Osleger, David A.; Arthur, Michael A.; Bice, David M.; Herbert, Timothy D.; Erba, Elisabetta; Premoli Silva, Isabella

2008-07-01

The early Aptian Oceanic Anoxic Event (OAE1a, 120 Ma) represents a geologically brief time interval in the mid-Cretaceous greenhouse world that is characterized by increased organic carbon accumulation in marine sediments, sudden biotic changes, and abrupt carbon-isotope excursions indicative of significant perturbations to global carbon cycling. The brevity of these drastic environmental changes (< 10 6 year) and the typically 10 6 year temporal resolution of the available chronologies, however, represent a critical gap in our knowledge of OAE1a. We have conducted a high-resolution investigation of three widely distributed sections, including the Cismon APTICORE in Italy, Santa Rosa Canyon in northeastern Mexico, and Deep Sea Drilling Project (DSDP) Site 398 off the Iberian margin in the North Atlantic Ocean, which represent a range of depositional environments where condensed and moderately expanded OAE1a intervals are recorded. The objectives of this study are to establish orbital chronologies for these sections and to construct a common, high-resolution timescale for OAE1a. Spectral analyses of the closely-spaced (corresponding to ~ 5 to 10 kyr) measurements of calcium carbonate content of the APTICORE, magnetic susceptibility (MS) and anhysteretic remanent magnetization (ARM) of the Santa Rosa samples, and MS, ARM and ARM/IRM, where IRM is isothermal remanent magnetization, of Site 398 samples reveal statistically significant cycles. These cycles exhibit periodicity ratios and modulation patterns similar to those of the mid-Cretaceous orbital cycles, suggesting that orbital variations may have modulated depositional processes. Orbital control allows us to estimate the duration of unique, globally identifiable stages of OAE1a. Although OAE1a had a duration of ~ 1.0 to 1.3 Myr, the initial perturbation represented by the negative carbon-isotope excursion was rapid, lasting for ~ 27-44 kyr. This estimate could serve as a basis for constraining triggering mechanisms for OAE1a.

JEM Experiment Logistics Module Pressurized Section

NASA Image and Video Library

2007-04-02

In the Space Station Processing Facility, the JEM Experiment Logistics Module Pressurized Section is lowered onto a scale for weight and center-of-gravity measurements. The module will then be moved to a work stand. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

Paleointensity and 40Ar/39Ar geochronology of basalts at Gamarri, Ethiopia: Correlation with the Réunion subchron and Huckleberry Ridge excursion?

NASA Astrophysics Data System (ADS)

Kindley, C.; Macho, A.; Tsegaye, M. A.; Feinberg, J. M.; Singer, B. S.; Jicha, B. R.; Brown, M. C.; Birke, T. K.

2012-12-01

Characterization of the geomagnetic field during subchrons, reversals, and excursions is vital to understanding geodynamo processes and interactions across the core-mantle boundary. Moreover, an accurate timescale for geomagnetic field instabilities is critical to global high resolution stratigraphy. The Réunion subchron and Huckleberry Ridge excursion are ideal candidates for study due to globally distributed recordings in both sedimentary and igneous rocks. We present new full-vector paleomagnetic data for 30 basaltic flows from the Gamarri volcanic section in the Afar region of Ethiopia and 11 40Ar/39Ar ages. Paleointensities were calculated using the LTD-DHT Shaw technique and results generally agree with those of Carlut et al. (1999). Two geomagnetic instabilities are recorded, an older excursion and a younger period of normal polarity within the reversed Matuyama chron. Our results show a longer duration of low (<20 μT) paleointensity in the oldest flows and more variable low paleointensity values in the younger flows, and are generally lower than Thellier-style values of Carlut et al. (1999). Relative to 28.201 Ma Fish Canyon sanidine, plateau 40Ar/39Ar ages of the youngest (GB21) and oldest (GA02) flows are 2.029 ± 0.041 (2σ) and 2.410 ± 0.130 Ma, respectively. This eruptive duration is longer than that reported by Kidane et al. (1999), where the unspiked K-Ar method yields ages for GB23 (2 flows overlying GB21) and GA02 of 2.02 ± 0.08 (2σ) and 2.14 ± 0.12 Ma, respectively. 40Ar/39Ar ages of 4 lavas within the normal polarity zone in the upper section are between 2.063 ± 0.044 and 2.118 ± 0.057 Ma, but are indistinguishable at 2σ. These flows may sample the Huckleberry Ridge excursion (2.086 ± 0.016 Ma, Singer et al. 2004), the Réunion subchron (2.153-2.115 Ma, Channell et al. 2003), or both. Given several 40Ar/39Ar ages >2.2 Ma, the older excursion in the Gamarri section is not consistent with the Réunion subchron, and can be linked to any of several excursions occurring between ~2.2 and ~2.5 Ma. These excursions have been observed within records from ODP 982 (Channell & Guyodo, 2004) and IODP U1314 (Ohno et al., 2012), as well as within the GPTS as cryptochron C2r.2r-1 (originally dated as 2.420 to 2.441 Ma by Cande & Kent, 1995). Thus, we no longer interpret the excursion recorded in the lower portion of the Gamarri section to be part of the Réunion subchron and recommend that it be omitted from efforts to construct integrated global field models across the Huckleberry Ridge excursion and Réunion subchron.

Evaluation of a new paleosecular variation activity index as a diagnostic tool for geomagnetic field variations

NASA Astrophysics Data System (ADS)

Panovska, Sanja; Constable, Catherine

2015-04-01

Geomagnetic indices like Dst, K and A, have been used since the early twentieth century to characterize activity in the external part of the modern geomagnetic field and as a diagnostic for space weather. These indices reflect regional and global activity and serve as a proxy for associated physical processes. However, no such tools are yet available for the internal geomagnetic field driven by the geodynamo in Earth's liquid outer core. To some extent this reflects limited spatial and temporal sampling for longer timescales associated with paleomagnetic secular variation, but recent efforts in both paleomagnetic data gathering and modeling activity suggest that longer term characterization of the internal geomagnetic weather/climate and its variability would be useful. Specifically, we propose an index for activity in paleosecular variation, useful as both a local and global measure of field stability during so-called normal secular variation and as a means of identifying more extreme behavior associated with geomagnetic excursions and reversals. To date, geomagnetic excursions have been identified by virtual geomagnetic poles (VGPs) deviating more than some conventional limit from the geographic pole (often 45 degrees), and/or by periods of significant intensity drops below some critical value, for example 50% of the present-day field. We seek to establish a quantitative definition of excursions in paleomagnetic records by searching for synchronous directional deviations and lows in relative paleointensity. We combine paleointensity variations with deviations from the expected geocentric axial dipole (GAD) inclination in a single parameter, which we call the paleosecular variation (PSV) activity index. This new diagnostic can be used on any geomagnetic time series (individual data records, model predictions, spherical harmonic coefficients, etc.) to characterize the level of paleosecular variation activity, find excursions, or even study incipient reversals. Currently reversals can only be detected after they have occurred. A baseline for the new index is established using modern and Holocene geomagnetic field data and models to analyze 'normal' variability. We extend our analyses to the 100 ka interval where several excursions have been identified. We discuss the diminished or absent signatures of excursions in some records, the apparent transgressive behavior of detected excursions, and implications for transitional field behavior. The absence of specific excursions in some sediment records is attributed to smoothing by the sedimentary remanence acquisition process and low sedimentation rates. Overall PSV activity index is inversely correlated with dipole moment, indicating stronger impacts of non-axial-dipole secular variations during periods of low axial dipole strength. Excursional events found with the PSV activity index are analyzed in the context of global probability density functions for VGP positions. We studied the appearance of VGP clusters of the excursions to find the common characteristics of these instabilities, including the non-axial dipole features of the geomagnetic field. A better understanding of geomagnetic excursions will aid attempts to predict when such events might occur in the future.

A cryogenic multichannel electronically scanned pressure module

NASA Technical Reports Server (NTRS)

Shams, Qamar A.; Fox, Robert L.; Adcock, Edward E.; Kahng, Seun K.

1992-01-01

Consideration is given to a cryogenic multichannel electronically scanned pressure (ESP) module developed and tested over an extended temperature span from -184 to +50 C and a pressure range of 0 to 5 psig. The ESP module consists of 32 pressure sensor dice, four analog 8 differential-input multiplexers, and an amplifier circuit, all of which are packaged in a physical volume of 2 x 1 x 5/8 in with 32 pressure and two reference ports. Maximum nonrepeatability is measured at 0.21 percent of full-scale output. The ESP modules have performed consistently well over 15 times over the above temperature range and continue to work without any sign of degradation. These sensors are also immune to repeated thermal shock tests over a temperature change of 220 C/sec.

Paleomagnetic record for the past 80 ka from the Mahanadi basin, Bay of Bengal

NASA Astrophysics Data System (ADS)

Usapkar, A.; Dewangan, P.; Mazumdar, A.; Krishna, K. S.; Ramprasad, T.; Badesab, F. K.; Patil, M.; Gaikwad, V. V.

2018-01-01

High resolution paleomagnetic investigations were performed on a 50.08 m long sediment core (MD161/20) from Mahanadi basin, Bay of Bengal. Core yielded reliable paleomagnetic results for top 20 m below seafloor (mbsf) which spans about 80 ka. Based on the analysis of rock magnetic data, the core is subdivided into five distinct Zones: Zone 1 and Zone 2 cover top 20 mbsf and do not show any abrupt change in magnetic mineralogy, concentration and grain size. Zones 3 and 5 show significant reduction in χLF, χARM and SIRM due to dissolution of magnetic minerals. Zone 4 shows moderate values of χLF and SIRM. The low value of χARM suggests that magnetic signal is mostly carried by magnetic grains in PSD/MD state. The paleomagnetic data for the top 20 mbsf show four prominent geomagnetic excursions at ∼9 mbsf, ∼13.5 to 15 mbsf, ∼16.3 mbsf and ∼18 to 18.2 mbsf. The age-depth relationship is established using stratigraphic correlation between well-dated sedimentary core NGHP-01-19B and the core MD161/20. The ages of the observed excursions correspond to ∼18 to 20 ka, ∼42 to 49 ka, ∼54 to 57 ka and ∼69 to 70 ka. The excursions at ∼42 to 49 ka, ∼54 to 57 ka, and ∼67 to 70 ka is similar to the known excursions the Laschamp and the split Norwegian-Greenland Sea events (NGS-I and NGS-II). The excursion at 18-20 ka is not observed globally and may be related to lithological/sedimentological changes occurring during last glacial maxima (LGM). The virtual geomagnetic path (VGP) of Laschamp excursion traces clockwise loop. All excursions identified in present study fall in the periods of relatively low paleointensity.

Relationship of medial gastrocnemius relative fascicle excursion and ankle joint power and work performance during gait in typically developing children: A cross-sectional study.

PubMed

Martín Lorenzo, Teresa; Albi Rodríguez, Gustavo; Rocon, Eduardo; Martínez Caballero, Ignacio; Lerma Lara, Sergio

2017-07-01

Muscle fascicles lengthen in response to chronic passive stretch through in-series sarcomere addition in order to maintain an optimum sarcomere length. In turn, the muscles' force generating capacity, maximum excursion, and contraction velocity is enhanced. Thus, longer fascicles suggest a greater capacity to develop joint power and work. However, static fascicle length measurements may not be taking sarcomere length differences into account. Thus, we considered relative fascicle excursions through passive ankle dorsiflexion may better correlate with the capacity to generate joint power and work than fascicle length. Therefore, the aim of the present study was to determine if medial gastrocnemius relative fascicle excursions correlate with ankle joint power and work generation during gait in typically developing children. A sample of typically developing children (n = 10) were recruited for this study and data analysis was carried out on 20 legs. Medial gastrocnemius relative fascicle excursion from resting joint angle to maximum dorsiflexion was estimated from trigonometric relations of medial gastrocnemius pennation angle and thickness obtained from B-mode real-time ultrasonography. Furthermore, a three-dimensional motion capture system was used to obtain ankle joint work and power during the stance phase of gait. Significant correlations were found between relative fascicle excursion and peak power absorption (-) r(14) = -0.61, P = .012 accounting for 31% variability, positive work r(18) = 0.56, P = .021 accounting for 31% variability, and late stance positive work r(15) = 0.51, P = .037 accounting for 26% variability. The large unexplained variance may be attributed to mechanics of neighboring structures (e.g., soleus or Achilles tendon mechanics) and proximal joint kinetics which may also contribute to ankle joint power and work performance, and were not taken into account. Further studies are encouraged to provide greater insight on the relationship between relative fascicle excursions and joint function.

Relationship of medial gastrocnemius relative fascicle excursion and ankle joint power and work performance during gait in typically developing children

PubMed Central

Martín Lorenzo, Teresa; Albi Rodríguez, Gustavo; Rocon, Eduardo; Martínez Caballero, Ignacio; Lerma Lara, Sergio

2017-01-01

Abstract Muscle fascicles lengthen in response to chronic passive stretch through in-series sarcomere addition in order to maintain an optimum sarcomere length. In turn, the muscles’ force generating capacity, maximum excursion, and contraction velocity is enhanced. Thus, longer fascicles suggest a greater capacity to develop joint power and work. However, static fascicle length measurements may not be taking sarcomere length differences into account. Thus, we considered relative fascicle excursions through passive ankle dorsiflexion may better correlate with the capacity to generate joint power and work than fascicle length. Therefore, the aim of the present study was to determine if medial gastrocnemius relative fascicle excursions correlate with ankle joint power and work generation during gait in typically developing children. A sample of typically developing children (n = 10) were recruited for this study and data analysis was carried out on 20 legs. Medial gastrocnemius relative fascicle excursion from resting joint angle to maximum dorsiflexion was estimated from trigonometric relations of medial gastrocnemius pennation angle and thickness obtained from B-mode real-time ultrasonography. Furthermore, a three-dimensional motion capture system was used to obtain ankle joint work and power during the stance phase of gait. Significant correlations were found between relative fascicle excursion and peak power absorption (–) r(14) = −0.61, P = .012 accounting for 31% variability, positive work r(18) = 0.56, P = .021 accounting for 31% variability, and late stance positive work r(15) = 0.51, P = .037 accounting for 26% variability. The large unexplained variance may be attributed to mechanics of neighboring structures (e.g., soleus or Achilles tendon mechanics) and proximal joint kinetics which may also contribute to ankle joint power and work performance, and were not taken into account. Further studies are encouraged to provide greater insight on the relationship between relative fascicle excursions and joint function. PMID:28723790

Improved Quaternary North Atlantic stratigraphy using relative paleointensity (RPI), oxygen isotopes, and magnetic excursions (Invited)

NASA Astrophysics Data System (ADS)

Channell, J. E.

2013-12-01

Improving the resolution of Quaternary marine stratigraphy is one of the major challenges in paleoceanography. IODP Expedition 303/306, and ODP Legs 162 and 172, have yielded multiple high-resolution records (mean sedimentation rates in the 7-20 cm/kyr range) of relative paleointensity (RPI) that are accompanied by oxygen isotope data and extend through much of the Quaternary. Tandem fit of RPI and oxygen isotope data to calibrated templates (LR04 and PISO), using the Match protocol, yields largely consistent stratigraphies, implying that both RPI and oxygen isotope data are dominated by regional/global signals. Based on the recent geomagnetic field, RPI can be expected to be a global signal (i.e. dominated by the axial dipole field) when recorded at sedimentation rates less than several decimeters/kyr. Magnetic susceptibility, on the other hand, is a local/regional lithologic signal, and therefore less useful for long-distance correlation. Magnetic excursions are directional phenomena and, when adequately recorded, are manifest as paired reversals in which the virtual geomagnetic poles (VGPs) reach high latitudes in the opposite hemisphere, and they occupy minima in RPI records. Reversed VGPs imply that excursions are attributable to the main axial dipole, and therefore provide global stratigraphy. The so-called Iceland Basin excursion is recorded at many IODP/ODP sites and lies at the MIS 6/7 boundary at ~188 ka, with a duration of 2-3 kyr. Other excursions in the Brunhes chron are less commonly recorded because their duration (perhaps <~1 kyr) requires sedimentation rates >20 cm/kyr to be adequately recorded. On the other hand, several excursions within the Matuyama Chron are more commonly recorded in North Atlantic drift sediments due to relatively elevated durations. With some notable exceptions (e.g. Iberian Margin), high quality RPI records from North Atlantic sediments, together with magnetic excursions, can be used in tandem with oxygen isotope data to strengthen Quaternary (North Atlantic) stratigraphy.

Volcanic records of the Laschamp geomagnetic excursion from Mt Ruapehu, New Zealand

NASA Astrophysics Data System (ADS)

Ingham, E.; Turner, G. M.; Conway, C. E.; Heslop, D.; Roberts, A. P.; Leonard, G.; Townsend, D.; Calvert, A.

2017-08-01

We present palaeodirectional records of the Laschamp geomagnetic excursion from lavas on Mt Ruapehu, New Zealand. Fourteen lava flows on the northwestern and southern flanks of Mt Ruapehu, with 40Ar/39Ar weighted mean plateau ages that range from 46.3 ± 2.0 to 39.9 ± 1.4 ka, were studied. The youngest and older flows carry a normal polarity magnetization; however, six flows, dated between 46.3 ± 2.0 and 42.7 ± 1.8 ka, record excursional directions. Three of these flows record southerly palaeomagnetic declinations and negative inclinations that agree well with a published Laschamp record from the Auckland Volcanic Field (AVF). Together, the AVF and Mt Ruapehu lavas currently represent the only volcanic records of the Laschamp excursion outside the Chaîne des Puys region, France. Thus, they make an important contribution to the global set of Laschamp excursion records. Virtual geomagnetic pole (VGP) groups for the New Zealand and French records early in the excursion are compatible with a dipole-dominated field that rotated to an equatorial orientation while simultaneously decaying in strength. In contrast, younger excursional flows from France and New Zealand yield separate VGP groups, which suggest either that the field had a nondipolar morphology in this later phase, or that the VGP groups were not synchronous. 40Ar/39Ar ages for the Mt Ruapehu record are on average slightly older than published northern hemisphere ages and from the relative palaeointensity minimum in the GLOPIS sedimentary stack. Although few individual ages differ significantly at the 2σ level, the spread suggests an overall excursion duration that is longer than the currently accepted 1500 years. This age spread may result from excess Ar in magmas at the time of the eruption biasing the results to slightly older ages, or from non-synchronous excursional field behaviour at near-antipodal locations, or, possibly, a precursory phase prior to the main excursion.

Mono Lake excursion recorded in sediment of the Santa Clara Valley, California

USGS Publications Warehouse

Mankinen, Edward A.; Wentworth, Carl M.

2004-01-01

Two intervals recording anomalous paleomagnetic inclinations were encountered in the top 40 meters of research drill hole CCOC in the Santa Clara Valley, California. The younger of these two intervals has an age of 28,090 ± 330 radiocarbon years B.P. (calibrated age ∼32.8 ka). This age is in excellent agreement with the latest estimate for the Mono Lake excursion at the type locality and confirms that the excursion has been recorded by sediment in the San Francisco Bay region. The age of an anomalous inclination change below the Mono Lake excursion was not directly determined, but estimates of sedimentation rates indicate that the geomagnetic behavior it represents most likely occurred during the Mono Lake/Laschamp time interval (∼45–28 ka). If true, it may represent one of several recurring fluctuations of magnetic inclination during an interval of a weak geomagnetic dipole, behavior noted in other studies in the region.

Testing the Self-Consistency of the Excursion Set Approach to Predicting the Dark Matter Halo Mass Function

NASA Astrophysics Data System (ADS)

Achitouv, I.; Rasera, Y.; Sheth, R. K.; Corasaniti, P. S.

2013-12-01

The excursion set approach provides a framework for predicting how the abundance of dark matter halos depends on the initial conditions. A key ingredient of this formalism is the specification of a critical overdensity threshold (barrier) which protohalos must exceed if they are to form virialized halos at a later time. However, to make its predictions, the excursion set approach explicitly averages over all positions in the initial field, rather than the special ones around which halos form, so it is not clear that the barrier has physical motivation or meaning. In this Letter we show that once the statistical assumptions which underlie the excursion set approach are considered a drifting diffusing barrier model does provide a good self-consistent description both of halo abundance as well as of the initial overdensities of the protohalo patches.

Jaw motion during gum-chewing in children with primary dentition.

PubMed

Kubota, Naoko; Hayasaki, Haruaki; Saitoh, Issei; Iwase, Yoko; Maruyama, Tomoaki; Inada, Emi; Hasegawa, Hiroko; Yamada, Chiaki; Takemoto, Yoshihiko; Matsumoto, Yuko; Yamasaki, Youichi

2010-01-01

This study was undertaken to characterize jaw motion during mastication in children with primary dentition and to compare jaw motion with that in adults. The means and the variances of the traditional parameters for the chewing cycle, i.e., duration, excursive ranges and 3-D distances of travel at the lower incisor, molars and condyles were analyzed and compared in 23 children and 25 female adults. The duration of opening in children was significantly shorter than that of adults. Significant differences between children and adults were observed in lateral and vertical excursion of the incisor, lateral excursion at the molars, and vertical excursion at the condyles. Many of these measurements had larger between-subject and between-cycle variances in children than adults, suggesting that chewing motion in children has not yet matured. The results of this study indicate that chewing motion in children is different from that of adults.

Use of hydrostatic pressure for modulation of protein chemical modification and enzymatic selectivity.

PubMed

Makarov, Alexey A; Helmy, Roy; Joyce, Leo; Reibarkh, Mikhail; Maust, Mathew; Ren, Sumei; Mergelsberg, Ingrid; Welch, Christopher J

2016-05-11

Using hydrostatic pressure to induce protein conformational changes can be a powerful tool for altering the availability of protein reactive sites and for changing the selectivity of enzymatic reactions. Using a pressure apparatus, it has been demonstrated that hydrostatic pressure can be used to modulate the reactivity of lysine residues of the protein ubiquitin with a water-soluble amine-specific homobifunctional coupling agent. Fewer reactive lysine residues were observed when the reaction was carried out under elevated pressure of 3 kbar, consistent with a pressure-induced conformational change of ubiquitin that results in fewer exposed lysine residues. Additionally, modulation of the stereoselectivity of an enzymatic transamination reaction was observed at elevated hydrostatic pressure. In one case, the minor diasteromeric product formed at atmospheric pressure became the major product at elevated pressure. Such pressure-induced alterations of protein reactivity may provide an important new tool for enzymatic reactions and the chemical modification of proteins.

The Habitat Demonstration Unit Project Overview

NASA Technical Reports Server (NTRS)

Kennedy, Kriss J.; Grill, Tracy R.; Tri, Terry O.; Howe, Alan S.

2010-01-01

This paper will describe an overview of the National Aeronautics and Space Administration (NASA) led multi-center Habitat Demonstration Unit (HDU) Project. The HDU project is a "technology-pull" project that integrates technologies and innovations from numerous NASA centers. This project will be used to investigate and validate surface architectures, operations concepts, and requirements definition of various habitation concepts. The first habitation configuration this project will build and test is the Pressurized Excursion Module (PEM). This habitat configuration - the PEM - is based on the Constellation Architecture Scenario 12.1 concept of a vertically oriented habitat module. The HDU project will be tested as part of the 2010 Desert Research and Technologies Simulations (D-RATS) test objectives. The purpose of this project is to develop, integrate, test, and evaluate a habitat configuration in the context of the mission architectures and surface operation concepts. A multi-center approach will be leveraged to build, integrate, and test the PEM through a shared collaborative effort of multiple NASA centers. The HDU project is part of the strategic plan from the Exploration Systems Mission Directorate (ESMD) Directorate Integration Office (DIO) and the Lunar Surface Systems Project Office (LSSPO) to test surface elements in a surface analog environment. The 2010 analog field test will include two Lunar Electric Rovers (LER) and the PEM among other surface demonstration elements. This paper will describe the overall objectives, its various habitat configurations, strategic plan, and technology integration as it pertains to the 2010 and 2011 field analog tests. To accomplish the development of the PEM from conception in June 2009 to rollout for operations in July 2010, the HDU project team is using a set of design standards to define the interfaces between the various systems of PEM and to the payloads, such as the Geology Lab, that those systems will support. Scheduled activities such as early fit-checks and the utilization of a habitat avionics test bed prior to equipment installation into PEM are planned to facilitate the integration process.

The impact of previous knee injury on force plate and field-based measures of balance.

PubMed

Baltich, Jennifer; Whittaker, Jackie; Von Tscharner, Vinzenz; Nettel-Aguirre, Alberto; Nigg, Benno M; Emery, Carolyn

2015-10-01

Individuals with post-traumatic osteoarthritis demonstrate increased sway during quiet stance. The prospective association between balance and disease onset is unknown. Improved understanding of balance in the period between joint injury and disease onset could inform secondary prevention strategies to prevent or delay the disease. This study examines the association between youth sport-related knee injury and balance, 3-10years post-injury. Participants included 50 individuals (ages 15-26years) with a sport-related intra-articular knee injury sustained 3-10years previously and 50 uninjured age-, sex- and sport-matched controls. Force-plate measures during single-limb stance (center-of-pressure 95% ellipse-area, path length, excursion, entropic half-life) and field-based balance scores (triple single-leg hop, star-excursion, unipedal dynamic balance) were collected. Descriptive statistics (mean within-pair difference; 95% confidence intervals) were used to compare groups. Linear regression (adjusted for injury history) was used to assess the relationship between ellipse-area and field-based scores. Injured participants on average demonstrated greater medio-lateral excursion [mean within-pair difference (95% confidence interval); 2.8mm (1.0, 4.5)], more regular medio-lateral position [10ms (2, 18)], and shorter triple single-leg hop distances [-30.9% (-8.1, -53.7)] than controls, while no between group differences existed for the remaining outcomes. After taking into consideration injury history, triple single leg hop scores demonstrated a linear association with ellipse area (β=0.52, 95% confidence interval 0.01, 1.01). On average the injured participants adjusted their position less frequently and demonstrated a larger magnitude of movement during single-limb stance compared to controls. These findings support the evaluation of balance outcomes in the period between knee injury and post-traumatic osteoarthritis onset. Copyright © 2015 Elsevier Ltd. All rights reserved.

Response to Tendon Vibration Questions the Underlying Rationale of Proprioceptive Training.

PubMed

Lubetzky, Anat Vilnai; McCoy, Sarah Westcott; Price, Robert; Kartin, Deborah

2017-02-01

Proprioceptive training on compliant surfaces is used to rehabilitate and prevent ankle sprains. The ability to improve proprioceptive function via such training has been questioned. Achilles tendon vibration is used in motor-control research as a form of proprioceptive stimulus. Using measures of postural steadiness with nonlinear measures to elucidate control mechanisms, tendon vibration can be applied to investigate the underlying rationale of proprioceptive training. To test whether the effect of vibration on young adults' postural control depended on the support surface. Descriptive laboratory study. Research laboratory. Thirty healthy adults and 10 adults with chronic ankle instability (CAI; age range = 18-40 years). With eyes open, participants stood in bilateral stance on a rigid plate (floor), memory foam, and a Both Sides Up (BOSU) ball covering a force platform. We applied bilateral Achilles tendon vibration for the middle 20 seconds in a series of 60-second trials and analyzed participants' responses from previbration to vibration (pre-vib) and from vibration to postvibration (vib-post). We calculated anterior-posterior excursion of the center of pressure and complexity index derived from the area under multiscale entropy curves. The excursion response to vibration differed by surface, as indicated by a significant interaction of P < .001 for the healthy group at both time points and for the CAI group vib-post. Although both groups demonstrated increased excursion from pre-vib and from vib-post, a decrease was observed on the BOSU. The complexity response to vibration differed by surface for the healthy group (pre-vib, P < .001). The pattern for the CAI group was similar but not significant. Complexity changes vib-post were the same on all surfaces for both groups. Participants reacted less to ankle vibration when standing on the BOSU as compared with the floor, suggesting that proprioceptive training may not be occurring. Different balance-training paradigms to target proprioception, including tendon vibration, should be explored.

Lateral ligament repair and reconstruction restore neither contact mechanics of the ankle joint nor motion patterns of the hindfoot.

PubMed

Prisk, Victor R; Imhauser, Carl W; O'Loughlin, Padhraig F; Kennedy, John G

2010-10-20

Ankle sprains may damage both the lateral ligaments of the hindfoot and the osteochondral tissue of the ankle joint. When nonoperative treatment fails, operative approaches are indicated to restore both native motion patterns at the hindfoot and ankle joint contact mechanics. The goal of the present study was to determine the effect of lateral ligament injury, repair, and reconstruction on ankle joint contact mechanics and hindfoot motion patterns. Eight cadaveric specimens were tested with use of robotic technology to apply combined compressive (200-N) and inversion (4.5-Nm) loads to the hindfoot at 0° and 20° of plantar flexion. Contact mechanics at the ankle joint were simultaneously measured. A repeated-measures experiment was designed with use of the intact condition as control, with the other conditions including sectioned anterior talofibular and calcaneofibular ligaments, the Broström and Broström-Gould repairs, and graft reconstruction. Ligament sectioning decreased contact area and caused a medial and anterior shift in the center of pressure with inversion loads relative to those with the intact condition. There were no significant differences in inversion or coupled axial rotation with inversion between the Broström repair and the intact condition; however, medial translation of the center of pressure remained elevated after the Broström repair relative to the intact condition. The Gould modification of the Broström procedure provided additional support to the hindfoot relative to the Broström repair, reducing inversion and axial rotation with inversion beyond that of intact ligaments. There were no significant differences in center-of-pressure excursion patterns between the Broström-Gould repair and the intact ligament condition, but this repair increased contact area beyond that with the ligaments intact. Graft reconstruction more closely restored inversion motion than did the Broström-Gould repair at 20° of plantar flexion but limited coupled axial rotation. Graft reconstruction also increased contact areas beyond the lateral ligament-deficient conditions but altered center-of-pressure excursion patterns relative to the intact condition. No lateral ankle ligament reconstruction completely restored native contact mechanics of the ankle joint and hindfoot motion patterns.

Reduced Cognitive-Motor Interference on Voluntary Balance Control in Older Tai Chi Practitioners.

PubMed

Varghese, Rini; Hui-Chan, Christina W Y; Bhatt, Tanvi

2016-01-01

Recent dual-task studies suggest that Tai Chi practitioners displayed better control of standing posture and maintained a quicker response time of postural muscle activation during a stepping down activity. Whether this effect extends to voluntary balance control, specifically the limits of excursion of the center of pressure, remains to be examined. The purpose of this study was to evaluate the cognitive-motor interference pattern by examining the effects of a concurrently performed cognitive task on attention of voluntary balance control in older adults who are long-term practitioners of Tai Chi. Ten older Tai Chi practitioners and 10 age-matched nonpractitioners performed a voluntary balance task that required them to shift their weight to reach a preset target in the forward and backward directions, with (single task, ST) and without (dual task, DT) a secondary cognitive task, which was the counting backward task. The counting backward task required the individual to compute and verbalize a series of arithmetic differences between a given pair of randomly generated numbers. The cognitive task was also performed independently (cognitive-ST). All trials were performed in a random order. Balance outcomes included reaction time, movement velocity, and maximal excursion of the center of pressure provided by the NeuroCom system. Cognitive outcome was the number of correct responses generated within the 8-second trial during the ST and DT conditions. Outcome variables were analyzed using a 2-factor, group by task, analysis of variance. DT costs for the variables were calculated as the relative difference between ST and DT conditions and were compared between the 2 groups using independent t tests. Tai Chi practitioners displayed shorter reaction times (P < .001) and faster movement velocities (P < .05) of their center of pressure than older nonpractitioners for both directions; however, no difference was found between the maximal excursions of the 2 groups. Cost analyses revealed that reaction time and cognitive costs were significantly lower in the Tai Chi practitioners for both forward and backward directions (P < .05); however, similar findings for movement velocity costs were significant only in the backward direction (P < .05). Our results suggest that Tai Chi practitioners expended fewer motor and cognitive resources than older nonpractitioners during a fairly complex (dynamic) postural equilibrium task while performing a verbal working memory task. They exhibited lesser cognitive-motor interference and thus better allocation of attentional resources toward the voluntary balance control task. Given that dynamic balance is a crucial prerequisite for walking and dual-tasking ability is considered to be a significant predictor of falls in older adults, our results might point at the possible long-term benefits of Tai Chi practice to counteract age-related decline in dual-tasking ability. Findings present preliminary data for further investigation, especially related to potential benefits in fall prevention.

Using the World's Tallest Barometer as a Demonstration Apparatus

NASA Astrophysics Data System (ADS)

Bennett, T. E.

2016-12-01

The barometer has been around since the early 1640's when Italian scientists Berte inadvertently made a water barometer and Torricelli purposely made a mercury barometer. A water barometer has the problem of high vapor pressure, so that it does not maintain a good vacuum above the water column unless continually vacuum pumped. The high density of mercury and its low vapor pressure allows a mercury barometer to be a compact and accurate lab apparatus. The tall barometer at Portland State University's Maseeh College of Engineering atrium makes use of doubly distilled synthetic vacuum pump oil as the working fluid. The fluid has a specific gravity of 0.83 and very low vapor pressure. The nominal height of this barometer is 12.45m, with excursions of +/- 0.40m. This barometer is used in the Civil Engineering Fluids Lab as a lab apparatus and it is also used during general tours of the building. With the placement of the tall barometer in the atrium of the Engineering Building, the barometer is very visible to all PSU engineering students and visitors to the building.

Control integration concept for hypersonic cruise-turn maneuvers

NASA Technical Reports Server (NTRS)

Raney, David L.; Lallman, Frederick J.

1992-01-01

Piloting difficulties associated with conducting aircraft maneuvers in hypersonic flight are caused in part by the nonintuitive nature of the aircraft response and the stringent constraints anticipated on allowable angle of attack and dynamic pressure variations. An approach is documented that provides precise, coordinated maneuver control during excursions from a hypersonic cruise flight path and the necessary flight condition constraints. The approach is to achieve specified guidance commands by resolving altitude and cross range errors into a load factor and bank angle command by using a coordinate transformation that acts as an interface between outer and inner loop flight controls. This interface, referred to as a 'resolver', applies constraints on angle of attack and dynamic pressure perturbations while prioritizing altitude regulation over cross range. An unpiloted test simulation, in which the resolver was used to drive inner loop flight controls, produced time histories of responses to guidance commands and atmospheric disturbances at Mach numbers of 6, 10, 15, and 20. Angle of attack and throttle perturbation constraints, combined with high speed flight effects and the desire to maintain constant dynamic pressure, significantly impact the maneuver envelope for a hypersonic vehicle.

Monitoring Composite Material Pressure Vessels with a Fiber-Optic/Microelectronic Sensor System

NASA Technical Reports Server (NTRS)

Klimcak, C.; Jaduszliwer, B.

1995-01-01

We discuss the concept of an integrated, fiber-optic/microelectronic distributed sensor system that can monitor composite material pressure vessels for Air Force space systems to provide assessments of the overall health and integrity of the vessel throughout its entire operating history from birth to end of life. The fiber optic component would include either a semiconductor light emitting diode or diode laser and a multiplexed fiber optic sensing network incorporating Bragg grating sensors capable of detecting internal temperature and strain. The microelectronic components include a power source, a pulsed laser driver, time domain data acquisition hardware, a microprocessor, a data storage device, and a communication interface. The sensing system would be incorporated within the composite during its manufacture. The microelectronic data acquisition and logging system would record the environmental conditions to which the vessel has been subjected to during its storage and transit, e.g., the history of thermal excursions, pressure loading data, the occurrence of mechanical impacts, the presence of changing internal strain due to aging, delamination, material decomposition, etc. Data would be maintained din non-volatile memory for subsequent readout through a microcomputer interface.

Container materials in environments of corroded spent nuclear fuel

NASA Astrophysics Data System (ADS)

Huang, F. H.

1996-07-01

Efforts to remove corroded uranium metal fuel from the K Basins wet storage to long-term dry storage are underway. The multi-canister overpack (MCO) is used to load spent nuclear fuel for vacuum drying, staging, and hot conditioning; it will be used for interim dry storage until final disposition options are developed. Drying and conditioning of the corroded fuel will minimize the possibility of gas pressurization and runaway oxidation. During all phases of operations the MCO is subjected to radiation, temperature and pressure excursions, hydrogen, potential pyrophoric hazard, and corrosive environments. Material selection for the MCO applications is clearly vital for safe and efficient long-term interim storage. Austenitic stainless steels (SS) such as 304L SS or 316L SS appear to be suitable for the MCO. Of the two, Type 304L SS is recommended because it possesses good resistance to chemical corrosion, hydrogen embrittlement, and radiation-induced corrosive species. In addition, the material has adequate strength and ductility to withstand pressure and impact loading so that the containment boundary of the container is maintained under accident conditions without releasing radioactive materials.

Extension of wavelength-modulation spectroscopy to large modulation depth for diode laser absorption measurements in high-pressure gases

NASA Astrophysics Data System (ADS)

Li, Hejie; Rieker, Gregory B.; Liu, Xiang; Jeffries, Jay B.; Hanson, Ronald K.

2006-02-01

Tunable diode laser absorption measurements at high pressures by use of wavelength-modulation spectroscopy (WMS) require large modulation depths for optimum detection of molecular absorption spectra blended by collisional broadening or dense spacing of the rovibrational transitions. Diode lasers have a large and nonlinear intensity modulation when the wavelength is modulated over a large range by injection-current tuning. In addition to this intensity modulation, other laser performance parameters are measured, including the phase shift between the frequency modulation and the intensity modulation. Following published theory, these parameters are incorporated into an improved model of the WMS signal. The influence of these nonideal laser effects is investigated by means of wavelength-scanned WMS measurements as a function of bath gas pressure on rovibrational transitions of water vapor near 1388 nm. Lock-in detection of the magnitude of the 2f signal is performed to remove the dependence on detection phase. We find good agreement between measurements and the improved model developed for the 2f component of the WMS signal. The effects of the nonideal performance parameters of commercial diode lasers are especially important away from the line center of discrete spectra, and these contributions become more pronounced for 2f signals with the large modulation depths needed for WMS at elevated pressures.

Aptian Carbon Isotope Stratigraphy in Sierra del Rosario, Northeastern Mexico

NASA Astrophysics Data System (ADS)

Barragan-Manzo, R.; Moreno-Bedmar, J.; Nuñez, F.; Company, M.

2013-05-01

In most recent years Aptian carbon isotope stratigraphy has been widely studied in Europe where isotopic stages have been developed to correlate global events. Two negative excursions have been recorded in the Lower Aptian, the older is OAE 1a in the middle part, and a younger negative excursion labeled "Aparein level", which occurs in the uppermost part of the Lower Aptian. In Mexico previous works reported a carbon isotope negative excursion in the lowermost part of the La Peña Formation that was assigned to the onset of Oceanic Anoxic Event 1a (=OAE 1a). In this work we study the isotopic record of the δ13Ccarb of 32 bulk rock samples of limestone from the uppermost part of the Cupido Formation and the lower part of the La Peña Formation at the Francisco Zarco Dam Section (=FZD), Durango State, northeastern Mexico. The isotopic data are calibrated using the latest ammonite biostratigraphic biozonation of the Aptian. This age calibration allows us to make a precise correlation between the carbon isotopic record of Mexico and several European sections (e.g. Spain and France). In the studied Francisco Zarco Dam section we recognize a negative carbon isotopic excursion in the Dufrenoyia justinae ammonite Zone that corresponds to the "Aparein level", which we correlate using the ammonite zonation of others European sections (Figure 1). This correlation allows us to see how the negative excursion that characterizes the "Aparein level" is consistent with the C7 segment. Thus, our recent stratigraphic study allows us to conclude that the ammonite record in the lowermost part of the La Peña Formation is regionally isochronous, and correlates with the Dufrenoyia justinae Zone and Lower Aptian isotope interval C7. In agreement to these biostratigraphic data, the supposed record of the OAE 1a in the lowermost part of the La Peña Formation is not correct, and the carbon isotope negative excursion must be assigned to the younger event "Aparein level". Taking this into account, other Lower Aptian negative excursions reported in the literature and assigned to the OAE 1a, perhaps, must be reconsidered to distinguish among the two Lower Aptian negative excursions.; Figure 1: Isotopic curve of the FZD section compared with one section of Spain. The sharp negative peak in the Mexican section is compared with the Spanish section (see the arrow).

Field-effect Flow Control in Polymer Microchannel Networks

NASA Technical Reports Server (NTRS)

Sniadecki, Nathan; Lee, Cheng S.; Beamesderfer, Mike; DeVoe, Don L.

2003-01-01

A new Bio-MEMS electroosmotic flow (EOF) modulator for plastic microchannel networks has been developed. The EOF modulator uses field-effect flow control (FEFC) to adjust the zeta potential at the Parylene C microchannel wall. By setting a differential EOF pumping rate in two of the three microchannels at a T-intersection with EOF modulators, the induced pressure at the intersection generated pumping in the third, field-free microchannel. The EOF modulators are able to change the magnitude and direction of the pressure pumping by inducing either a negative or positive pressure at the intersection. The flow velocity is tracked by neutralized fluorescent microbeads in the microchannels. The proof-of-concept of the EOF modulator described here may be applied to complex plastic ,microchannel networks where individual microchannel flow rates are addressable by localized induced-pressure pumping.

Human Exploration of Phobos

NASA Technical Reports Server (NTRS)

Abercromby, Andrew F. J.; Chappell, Steven P.; Gernhardt, Michael L.; Lee, David E.; Howe, A. Scott

2015-01-01

This study developed, analyzed, and compared mission architectures for human exploration of Mars' Moons within the context of an Evolvable Mars Campaign. METHODS: All trades assumed conjunction class missions to Phobos (approximately 500 days in Mars system) as it was considered the driving case for the transportation architecture. All architectures assumed that the Mars Transit Habitat would remain in a High Mars Orbit with crewmembers transferring between HMO and Phobos in a small crew taxi vehicle. A reference science / exploration program was developed including performance of a standard set of tasks at 55 locations on the Phobos surface. Detailed EVA timelines were developed using realistic flight rules to accomplish the reference science tasks using exploration systems ranging from jetpacks to multi-person pressurized excursion vehicles combined with Phobos surface and orbital (L1, L4/L5, 20km Distant Retrograde Orbit) habitat options. Detailed models of propellant mass, crew time, science productivity, radiation exposure, systems and consumables masses, and other figures of merit were integrated to enable quantitative comparison of different architectural options. Options for pre-staging assets using solar electric propulsion (SEP) vs. delivering all systems with the crew were also evaluated. Seven discrete mission architectures were evaluated. RESULTS: The driving consideration for habitat location (Phobos surface vs. orbital) was radiation exposure, with an estimated reduction in cumulative mission radiation exposure of up to 34% (vs. Mars orbital mission) when the habitat is located on the Phobos surface, compared with only 3-6% reduction for a habitat in a 20km DRO. The exploration utility of lightweight unpressurized excursion vehicles was limited by the need to remain within 20 minutes of Solar Particle Event radiation protection combined with complex GN&C systems required by the non-intuitive and highly-variable gravitational environment. Two-person pressurized excursion vehicles as well as mobile surface habitats offer significant exploration capability and operational benefits compared with unpressurized EVA mobility systems at the cost of increased system and propellant mass. Mechanical surface translation modes (i.e. hopping) were modeled and offer potentially significant propellant savings and the possibility of extended exploration operations between crewed missions. Options for extending the utilization of the crew taxi vehicle were examined, including use as an exploration asset for Phobos surface exploration (when combined with an alternate mobility system) and as an EVA platform, both on Phobos and for contingency EVA on the Mars Transit Habitat. CONCLUSIONS: Human exploration of Phobos offers a scientifically meaningful first step towards human Mars surface missions that develops and validates transportation, habitation, and exploration systems and operations in advance of the Mars landing systems.

Method for pressure modulation of turbine sidewall cavities

DOEpatents

Leone, Sal Albert; Book, Matthew David; Banares, Christopher R.

2002-01-01

A method is provided for controlling cooling air flow for pressure modulation of turbine components, such as the turbine outer sidewall cavities. The pressure at which cooling and purge air is supplied to the turbine outer side wall cavities is modulated, based on compressor discharge pressure (Pcd), thereby to generally maintain the back flow margin (BFM) so as to minimize excessive leakage and the consequent performance deterioration. In an exemplary embodiment, the air pressure within the third stage outer side wall cavity and the air pressure within the fourth stage outer side wall cavity are each controlled to a respective value that is a respective prescribed percentage of the concurrent compressor discharge pressure. The prescribed percentage may be determined from a ratio of the respective outer side wall pressure to compressor discharge pressure at Cold Day Turn Down (CDTD) required to provide a prescribed back flow margin.

System for pressure modulation of turbine sidewall cavities

DOEpatents

Leone, Sal Albert; Book, Matthew David; Banares, Christopher R.

2002-01-01

A system and method are provided for controlling cooling air flow for pressure modulation of turbine components, such as the turbine outer sidewall cavities. The pressure at which cooling and purge air is supplied to the turbine outer side wall cavities is modulated, based on compressor discharge pressure (Pcd), thereby to generally maintain the back flow margin (BFM) so as to minimize excessive leakage and the consequent performance deterioration. In an exemplary embodiment, the air pressure within the third stage outer side wall cavity and the air pressure within the fourth stage outer side wall cavity are each controlled to a respective value that is a respective prescribed percentage of the concurrent compressor discharge pressure. The prescribed percentage may be determined from a ratio of the respective outer side wall pressure to compressor discharge pressure at Cold Day Turn Down (CDTD) required to provide a prescribed back flow margin.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto (center) joins others for a tour. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto (center) joins others for a tour. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

Entry Vehicle Control System Design for the Mars Smart Lander

NASA Technical Reports Server (NTRS)

Calhoun, Philip C.; Queen, Eric M.

2002-01-01

The NASA Langley Research Center, in cooperation with the Jet Propulsion Laboratory, participated in a preliminary design study of the Entry, Descent and Landing phase for the Mars Smart Lander Project. This concept utilizes advances in Guidance, Navigation and Control technology to significantly reduce uncertainty in the vehicle landed location on the Mars surface. A candidate entry vehicle controller based on the Reaction Control System controller for the Apollo Lunar Excursion Module digital autopilot is proposed for use in the entry vehicle attitude control. A slight modification to the phase plane controller is used to reduce jet-firing chattering while maintaining good control response for the Martian entry probe application. The controller performance is demonstrated in a six-degree-of-freedom simulation with representative aerodynamics.

Effect of potassium depletion in normal males - An Apollo 15 simulation

NASA Technical Reports Server (NTRS)

Hyatt, K. H.; Hulley, S. B.; Vogel, J. M.; Spears, C. P.; Johnson, P. C.; Hoffler, G. W.; Rambaut, P. C.; Rummel, J. A.; Huntoon, C.

1975-01-01

In the course of Apollo 15, physiologic abnormalities, manifested by ectopic activity on the ECG and unusual alterations in exercise tolerance, occurred in the crew of the Lunar Excursion Module. These were associated with decreases in total body potassium, measured by K-42, of 10% and 15%. The possibility of inadequate potassium (K+) intake existed. A simulation study was performed prior to Apollo 16, corresponding in duration to Apollo 15. Subjects endured the same sleep aberrations and caloric expenditure as the Apollo 15 astronauts. Subjects consumed a diet containing only 15 mEq/d of K+ during the entire 12 days of absolute bedrest. Study implications and reasons for discrepancies between K+ loss measured by balance techniques and K-42 are reviewed.

Paleomagnetic record determined in cores from deep research wells in the Quaternary Santa Clara basin, California

USGS Publications Warehouse

Mankinen, Edward A.; Wentworth, Carl M.

2016-01-01

The Mono Lake (ca. 32 ka), Pringle Falls (ca. 210 ka), and Big Lost (ca. 565 ka) geomagnetic excursions all seem to be represented in the Santa Clara Valley wells. Possible correlations to the Laschamp (ca. 40 ka) and Blake (ca. 110 ka) excursions are also noted. Three additional excursions that have apparently not been previously reported from western North America occur within cycle 6 (between 536 and 433 ka), near the base of cycle 5 (after 433 ka), and near the middle of cycle 2 (before ca. 75 ka).

Scaling fixed-field alternating gradient accelerators with a small orbit excursion.

PubMed

Machida, Shinji

2009-10-16

A novel scaling type of fixed-field alternating gradient (FFAG) accelerator is proposed that solves the major problems of conventional scaling and nonscaling types. This scaling FFAG accelerator can achieve a much smaller orbit excursion by taking a larger field index k. A triplet focusing structure makes it possible to set the operating point in the second stability region of Hill's equation with a reasonable sensitivity to various errors. The orbit excursion is about 5 times smaller than in a conventional scaling FFAG accelerator and the beam size growth due to typical errors is at most 10%.

Four-dimensional analysis by high-speed holographic imaging reveals a chiral memory of sperm flagella.

PubMed

Muschol, Michael; Wenders, Caroline; Wennemuth, Gunther

2018-01-01

Here high-speed Digital Holographic Microscopy (DHM) records sperm flagellar waveforms and swimming paths in 4 dimensions (X, Z, and t). We find flagellar excursions into the Z-plane nearly as large as the envelope of the flagellar waveform projected onto the XY-plane. These Z-plane excursions travel as waves down the flagellum each beat cycle. DHM also tracks the heads of free-swimming sperm and the dynamics and chirality of rolling of sperm around their long axis. We find that mouse sperm roll CW at the maximum positive Z-plane excursion of the head, then roll CCW at the subsequent maximum negative Z-plane excursion. This alternating chirality of rolling indicates sperm have a chiral memory. Procrustes alignments of path trajectories for sequences of roll-counterroll cycles show that path chirality is always CW for the cells analyzed in this study. Human and bull sperm lack distinguishable left and right surfaces, but DHM still indicates coordination of Z-plane excursions and rolling events. We propose that sperm have a chiral memory that resides in a hypothetical elastic linkage within the flagellar machinery, which stores some of the torque required for a CW or CCW roll to reuse in the following counter-roll. Separate mechanisms control path chirality.

Feasibility of controlling speed-dependent low-frequency brake vibration amplification by modulating actuation pressure

NASA Astrophysics Data System (ADS)

Sen, Osman Taha; Dreyer, Jason T.; Singh, Rajendra

2014-12-01

In this article, a feasibility study of controlling the low frequency torque response of a disc brake system with modulated actuation pressure (in the open loop mode) is conducted. First, a quasi-linear model of the torsional system is introduced, and analytical solutions are proposed to incorporate the modulation effect. Tractable expressions for three different modulation schemes are obtained, and conditions that would lead to a reduction in the oscillatory amplitudes are identified. Second, these conditions are evaluated with a numerical model of the torsional system with clearance nonlinearity, and analytical solutions are verified in terms of the trends observed. Finally, a laboratory experiment with a solenoid valve is built to modulate actuation pressure with a constant duty cycle, and time-frequency domain data are acquired. Measurements are utilized to assess analytical observations, and all methods show that the speed-dependent brake torque amplitudes can be altered with an appropriate modulation of actuation pressure.

Marine sediments and Beryllium-10 record of the geomagnetic moment variations during the Brunhes period.

NASA Astrophysics Data System (ADS)

Ménabréaz, Lucie; Thouveny, Nicolas; Bourlès, Didier; Demory, François

2010-05-01

Over millennial time scales, the atmospheric production of the cosmonuclid 10Be (half-life 1.387 ± 0.012 Ma [Shmeleff et al., 2009; Korschinek et al., 2009]) is modulated by the geomagnetic field strength, following a negative power law (e.g. Lal, 1988; Masarik and Beer, 2009). With respect to paleomagnetic reconstructions, 10Be-derived paleointensity records can therefore constitute an alternative, global and independent reading of the dipole moment variations. During the last years, efforts have been made to extract a geomagnetic signal from single and stacked 10Be records in natural archives such as ice and marine sediments (e.g. Carcaillet et al., 2004; Christl et al., 2007; Muscheler et al., 2005). In marine sediments, the 10Be concentration results from complex interplay of several processes: cosmogenic production, adsorption on sediment particles, redistribution by fluviatile and oceanic transport, and deposition. Therefore, a correction procedure is required to consider both sediment redistribution and enhanced scavenging, which can alter the primary signatures. To reconstruct the succession of field intensity lows accompanying excursions during the Brunhes chron, we investigated authigenic 10Be/9Be record of marine sequences also studied for paleomagnetism and oxygen isotopes. Mid and low latitude sites were preferred in order to benefit from the most efficient modulation by the magnetospheric shielding. We present a high resolution authigenic 10Be/9Be record of the last 50 ka recovered from the Portuguese Margin, that deciphers the cosmonuclide 10Be overproduction created by the geomagnetic dipole low associated with the Laschamp excursion. This record is compared to other proxy records of the geomagnetic field variations for the same time interval: (1) the relative paleointensity (RPI) reconstructed from the same sediments and the GLOPIS-75 record (Laj et al., 2004), (2) the absolute VDM record based on absolute paleointensities measured on lava flows, (3) the high-resolution deep sea floor magnetization record of the South East Pacific (Gee et al., 2000) and (4) other cosmogenic records obtained from different archives. A second normalization method using the 230Thxs (e.g. Frank et al., 1997) is presently applied on these samples and the results will allow establishing a cross evaluation and intercalibration. Two other marine sequences collected in the west-equatorial Pacific are also under investigation. These data and their combination to previous 10Be/9Be records will constitute the basis for the construction of a global marine 10Be-stack covering the whole Brunhes period and the numerous relevant excursions, as well as the Brunhes-Matuyama boundary. This study is funded through the "MAG-ORB" project ANR- 09-BLAN-0053-01.

JEM Experiment Logistics Module Pressurized Section

NASA Image and Video Library

2007-04-02

An overhead crane moves the JEM Experiment Logistics Module Pressurized Section above the floor of the Space Station Processing Facility to a scale for weight and center-of-gravity measurements. The module will then be moved to a work stand. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

JEM Experiment Logistics Module Pressurized Section

NASA Image and Video Library

2007-04-02

In the Space Station Processing Facility, an overhead crane moves the JEM Experiment Logistics Module Pressurized Section toward a scale (at left) for weight and center-of-gravity measurements. The module will then be moved to a work stand. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

JEM Experiment Logistics Module Pressurized Section

NASA Image and Video Library

2007-04-02

The JEM Experiment Logistics Module Pressurized Section is lifted from its shipping crate in the Space Station Processing Facility. The module will be moved to a scale for weight and center-of-gravity measurements and then to a work stand. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

JEM Experiment Logistics Module Pressurized Section

NASA Image and Video Library

2007-04-02

In the Space Station Processing Facility, an overhead crane lifts the JEM Experiment Logistics Module Pressurized Section from its shipping container and moves it toward a scale for weight and center-of-gravity measurements. The module will then be moved to a work stand. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

Interactive simulation system for artificial ventilation on the internet: virtual ventilator.

PubMed

Takeuchi, Akihiro; Abe, Tadashi; Hirose, Minoru; Kamioka, Koichi; Hamada, Atsushi; Ikeda, Noriaki

2004-12-01

To develop an interactive simulation system "virtual ventilator" that demonstrates the dynamics of pressure and flow in the respiratory system under the combination of spontaneous breathing, ventilation modes, and ventilator options. The simulation system was designed to be used by unexperienced health care professionals as a self-training tool. The system consists of a simulation controller and three modules: respiratory, spontaneous breath, and ventilator. The respiratory module models the respiratory system by three resistances representing the main airway, the right and left lungs, and two compliances also representing the right and left lungs. The spontaneous breath module generates inspiratory negative pressure produced by a patient. The ventilator module generates driving force of pressure or flow according to the combination of the ventilation mode and options. These forces are given to the respiratory module through the simulation controller. The simulation system was developed using HTML, VBScript (3000 lines, 100 kB) and ActiveX control (120 kB), and runs on Internet Explorer (5.5 or higher). The spontaneous breath is defined by a frequency, amplitude and inspiratory patterns in the spontaneous breath module. The user can construct a ventilation mode by setting a control variable, phase variables (trigger, limit, and cycle), and options. Available ventilation modes are: controlled mechanical ventilation (CMV), continuous positive airway pressure, synchronized intermittent mandatory ventilation (SIMV), pressure support ventilation (PSV), SIMV + PSV, pressure-controlled ventilation (PCV), pressure-regulated volume control (PRVC), proportional assisted ventilation, mandatory minute ventilation (MMV), bilevel positive airway pressure (BiPAP). The simulation system demonstrates in a graph and animation the airway pressure, flow, and volume of the respiratory system during mechanical ventilation both with and without spontaneous breathing. We developed a web application that demonstrated the respiratory mechanics and the basic theory of ventilation mode.

Automated cuff pressure modulation: a novel device to reduce endotracheal tube injury.

PubMed

Chadha, Neil K; Gordin, Arie; Luginbuehl, Igor; Patterson, Greg; Campisi, Paolo; Taylor, Glenn; Forte, Vito

2011-01-01

To assess whether dynamically modulating endotracheal tube (ETT) cuff pressure, by decreasing it during each ventilatory cycle instead of maintaining a constant level, would reduce the extent of intubation-related laryngotracheal injury. Single-blind, randomized controlled animal study using a previously validated live porcine model of accelerated intubation-related tracheal injury. Animal research facility. Ten piglets (weight, 16-20 kg each) were anesthetized and underwent intubation using a cuffed ETT. The animals were randomized into the following 2 groups: 5 pigs had a novel device to modulate their cuff pressure from 25 cm H₂O during inspiration to 7 cm H₂O during expiration, and 5 pigs had a constant cuff pressure of 25 cm H₂O. Both groups underwent ventilation under hypoxic conditions for 4 hours. Laryngotracheal mucosal injury after blinded histopathological assessment. The modulated-pressure group showed significantly less overall laryngotracheal damage than the constant-pressure group (mean grades, 1.2 vs 2.1; P < .001). Subglottic damage and tracheal damage were significantly less severe in the modulated-pressure group (mean grades, 1.0 vs 2.2; P < .001, and 1.9 vs 3.2; P < .001, respectively). There was no significant difference in glottic or supraglottic damage between the groups (P = .06 and .27, respectively). This novel device reduces the risk of subglottic and tracheal injury by modulating ETT cuff pressure in synchronization with the ventilatory cycle. This finding could have far-reaching implications for reducing the risk of airway injury in patients undergoing long-term intubation. Further clinical study of this device is warranted.

Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat

NASA Technical Reports Server (NTRS)

Howe, Alan; Kennedy, Kriss J.; Gill, Tracy R.; Tri, Terry O.; Toups, Larry; Howard, Robert I.; Spexarth, Gary R.; Cavanaugh, Stephen; Langford, William M.; Dorsey, John T.

2014-01-01

NASA's Constellation Architecture Team defined an outpost scenario optimized for intensive mobility that uses small, highly mobile pressurized rovers supported by portable habitat modules that can be carried between locations of interest on the lunar surface. A compact vertical cylinder characterizes the habitat concept, where the large diameter maximizes usable flat floor area optimized for a gravity environment and allows for efficient internal layout. The module was sized to fit into payload fairings for the Constellation Ares V launch vehicle, and optimized for surface transport carried by the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) mobility system. Launch and other loads are carried through the barrel to a top and bottom truss that interfaces with a structural support unit (SSU). The SSU contains self-leveling feet and docking interfaces for Tri-ATHLETE grasping and heavy lift. A pressurized module needed to be created that was appropriate for the lunar environment, could be easily relocated to new locations, and could be docked together in multiples for expanding pressurized volume in a lunar outpost. It was determined that horizontally oriented pressure vessels did not optimize floor area, which takes advantage of the gravity vector for full use. Hybrid hard-inflatable habitats added an unproven degree of complexity that may eventually be worked out. Other versions of vertically oriented pressure vessels were either too big, bulky, or did not optimize floor area. The purpose of the HDU vertical habitat module is to provide pressurized units that can be docked together in a modular way for lunar outpost pressurized volume expansion, and allow for other vehicles, rovers, and modules to be attached to the outpost to allow for IVA (intra-vehicular activity) transfer between them. The module is a vertically oriented cylinder with a large radius to allow for maximal floor area and use of volume. The modular, 5- m-diameter HDU vertical habitat module consists of a 2-m-high barrel with 0.6-mhigh end domes forming the 56-cubicmeter pressure vessel, and a 19-squaremeter floor area. The module has up to four docking ports located orthogonally from each other around the perimeter, and up to one docking port each on the top or bottom end domes. In addition, the module has mounting trusses top and bottom for equipment, and to allow docking with the ATHLETE mobility system. Novel or unique features of the HDU vertical habitat module include the nodelike function with multiple pressure hatches for docking with other versions of itself and other modules and vehicles; the capacity to be carried by an ATHLETE mobility system; and the ability to attach inflatable 'attic' domes to the top for additional pressurized volume.

Biology Excursions

ERIC Educational Resources Information Center

Baldock, R. N.

1973-01-01

Provides many useful suggestions and cautions for planning and executing a biology field excursion. Specific procedures are outlined for investigating land communities and coastal areas, and a number of follow-up laboratory activities are described. The appendix provides an extensive bibliography with useful comments on the literature. (JR)

Improving the Science Excursion: An Educational Technologist's View

ERIC Educational Resources Information Center

Balson, M.

1973-01-01

Analyzes the nature of the learning process and attempts to show how the three components of a reinforcement contingency, the stimulus, the response and the reinforcement can be utilized to increase the efficiency of a typical science learning experience, the excursion. (JR)

Pressurized solid oxide fuel cell integral air accumular containment

DOEpatents

Gillett, James E.; Zafred, Paolo R.; Basel, Richard A.

2004-02-10

A fuel cell generator apparatus contains at least one fuel cell subassembly module in a module housing, where the housing is surrounded by a pressure vessel such that there is an air accumulator space, where the apparatus is associated with an air compressor of a turbine/generator/air compressor system, where pressurized air from the compressor passes into the space and occupies the space and then flows to the fuel cells in the subassembly module, where the air accumulation space provides an accumulator to control any unreacted fuel gas that might flow from the module.

Influence of dietary protein on postprandial blood glucose levels in individuals with Type 1 diabetes mellitus using intensive insulin therapy.

PubMed

Paterson, M A; Smart, C E M; Lopez, P E; McElduff, P; Attia, J; Morbey, C; King, B R

2016-05-01

To determine the effects of protein alone (independent of fat and carbohydrate) on postprandial glycaemia in individuals with Type 1 diabetes mellitus using intensive insulin therapy. Participants with Type 1 diabetes mellitus aged 7-40 years consumed six 150 ml whey isolate protein drinks [0 g (control), 12.5, 25, 50, 75 and 100] and two 150 ml glucose drinks (10 and 20 g) without insulin, in randomized order over 8 days, 4 h after the evening meal. Continuous glucose monitoring was used to assess postprandial glycaemia. Data were collected from 27 participants. Protein loads of 12.5 and 50 g did not result in significant postprandial glycaemic excursions compared with control (water) throughout the 300 min study period (P > 0.05). Protein loads of 75 and 100 g resulted in lower glycaemic excursions than control in the 60-120 min postprandial interval, but higher excursions in the 180-300 min interval. In comparison with 20 g glucose, the large protein loads resulted in significantly delayed and sustained glucose excursions, commencing at 180 min and continuing to 5 h. Seventy-five grams or more of protein alone significantly increases postprandial glycaemia from 3 to 5 h in people with Type 1 diabetes mellitus using intensive insulin therapy. The glycaemic profiles resulting from high protein loads differ significantly from the excursion from glucose in terms of time to peak glucose and duration of the glycaemic excursion. This research supports recommendations for insulin dosing for large amounts of protein. © 2015 The Authors. Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.

Sex-specific gait adaptations prior to and up to six months after ACL reconstruction

PubMed Central

Stasi, Stephanie L. Di; Hartigan, Erin H.; Snyder-Mackler, Lynn

2015-01-01

STUDY DESIGN Controlled longitudinal laboratory study. OBJECTIVES Compare sagittal plane gait mechanics of men and women before and up to 6 months after anterior cruciate ligament reconstruction (ACLR). BACKGROUND Aberrant gait patterns are ubiquitous after anterior cruciate ligament (ACL) rupture and persist after ACLR despite skilled physical therapy. Sex influences post-operative function and second ACL injury risk, but its influence on gait adaptations after injury have not been investigated. METHODS Sagittal plane knee and hip joint excursions during midstance and internal knee and hip extension moments at peak knee flexion were collected on 12 women and 27 men using 3-dimensional gait analysis before (Screen) and after pre-operative physical therapy (Pre-sx), and 6 months after ACLR (6mo). Repeated measures analysis of variance models were used to determine whether limb asymmetries changed differently over time in men and women. RESULTS Significant time x limb x sex interactions were identified for hip and knee excursions and internal knee extension moments (P≤.007). Both sexes demonstrated smaller knee excursions on the involved compared to the uninvolved knee at each time point (P≤.007), but only women demonstrated a decrease in the involved knee excursion from pre-sx to 6mo (P=.03). Women also demonstrated smaller hip excursions (P<.001) and internal knee extension moments (P=.005) on the involved limb compared to the uninvolved limb at 6mo. Men demonstrated smaller hip excursions and knee moments on the involved limb compared to the uninvolved limb (main effects, P<.001). CONCLUSION The persistence of limb asymmetries in men and women 6 months after ACLR indicates that current rehabilitation efforts are inadequate for some individuals following ACLR. PMID:25627155

The Record of Geomagnetic Excursions from a ~150 m Sediment Core: Clear Lake, Northern California

NASA Astrophysics Data System (ADS)

Levin, E.; Byrne, R.; Looy, C. V.; Wahl, D.; Noren, A. J.; Verosub, K. L.

2015-12-01

We are studying the paleomagnetic properties of a new ~150 meter drill core from Clear Lake, CA. Step-wise demagnetization of the natural remanent magnetism (NRM) yields stable directions after 20 mT, implying that the sediments are reliable recorders of geomagnetic field behavior. Several intervals of low relative paleointensity (RPI) from the core appear to be correlated with known geomagnetic excursions. At about 46 m depth, and ~33 ka according to an age model based on radiocarbon dates obtained from pollen and the Olema ash bed, a low RPI zone seems to agree with the age and duration of the Mono Lake Excursion, previously identified between 32 and 35 ka. Slightly lower in the core, at about 50 m depth and ~40 ka, noticeably low RPI values seem to be coeval with the Laschamp excursion, which has been dated at ~41 ka. A volcanic ash near the bottom of the core (141 mblf) is near the same depth as an ash identified in 1988 by Andrei Sarna-Wojcicki and others as the Loleta ash bed in a previous Clear Lake core. If the basal ash in the new core is indeed the, Loleta ash bed, then the core may date back to about 270-300 ka. Depending on the age of the lowest ash, a sequence of low RPI intervals could correlate with the Blake (120 ka), Iceland Basin (188 ka), Jamaica/Pringle Falls (211 ka), and CR0 (260 ka) excursions. Correlation of the low RPI intervals to these geomagnetic excursions will help in the development of a higher resolution chronostratigraphy for the core, resolve a long-standing controversy about a possible hiatus in the Clear Lake record, and provide information about climatically-driven changes in sedimentation.

An electronic scanner of pressure for wind tunnel models

NASA Technical Reports Server (NTRS)

Kauffman, Ronald C.; Coe, Charles F.

1986-01-01

An electronic scanner of pressure (ESOP) has been developed by NASA Ames Research Center for installation in wind tunnel models. An ESOP system consists of up to 20 pressure modules (PMs), each with 48 pressure transducers and a heater, an analog-to-digital (A/D) converter module, a microprocessor, a data controller, a monitor unit, a control and processing unit, and a heater controller. The PMs and the A/D converter module are sized to be installed in the models tested in the Ames Aerodynamics Division wind tunnels. A unique feature of the pressure module is the lack of moving parts such as a pneumatic switch used in other systems for in situ calibrations. This paper describes the ESOP system and the results of the initial testing of the system. The initial results indicate the system meets the original design goal of 0.15 percent accuracy.

Pressure modulation algorithm to separate cerebral hemodynamic signals from extracerebral artifacts.

PubMed

Baker, Wesley B; Parthasarathy, Ashwin B; Ko, Tiffany S; Busch, David R; Abramson, Kenneth; Tzeng, Shih-Yu; Mesquita, Rickson C; Durduran, Turgut; Greenberg, Joel H; Kung, David K; Yodh, Arjun G

2015-07-01

We introduce and validate a pressure measurement paradigm that reduces extracerebral contamination from superficial tissues in optical monitoring of cerebral blood flow with diffuse correlation spectroscopy (DCS). The scheme determines subject-specific contributions of extracerebral and cerebral tissues to the DCS signal by utilizing probe pressure modulation to induce variations in extracerebral blood flow. For analysis, the head is modeled as a two-layer medium and is probed with long and short source-detector separations. Then a combination of pressure modulation and a modified Beer-Lambert law for flow enables experimenters to linearly relate differential DCS signals to cerebral and extracerebral blood flow variation without a priori anatomical information. We demonstrate the algorithm's ability to isolate cerebral blood flow during a finger-tapping task and during graded scalp ischemia in healthy adults. Finally, we adapt the pressure modulation algorithm to ameliorate extracerebral contamination in monitoring of cerebral blood oxygenation and blood volume by near-infrared spectroscopy.

Speckle tracking as a method to measure hemidiaphragm excursion.

PubMed

Goutman, Stephen A; Hamilton, James D; Swihart, Blake; Foerster, Bradley; Feldman, Eva L; Rubin, Jonathan M

2017-01-01

Diaphragm excursion measured via ultrasound may be an important imaging outcome measure of respiratory function. We developed a new method for measuring diaphragm movement and compared it to the more traditional M-mode method. Ultrasound images of the right and left hemidiaphragms were collected to compare speckle tracking and M-mode measurements of diaphragm excursion. Speckle tracking was performed using EchoInsight (Epsilon Imaging, Ann Arbor, Michigan). Six healthy subjects without a history of pulmonary diseases were included in this proof-of-concept study. Speckle tracking of the diaphragm is technically possible. Unlike M-mode, speckle tracking carries the advantage of reliable visualization and measurement of the left hemidiaphragm. Speckle tracking accounted for diaphragm movement simultaneously in the cephalocaudad and mediolateral directions, unlike M-mode, which is 1-dimensional. Diaphragm speckle tracking may represent a novel, more robust method for measuring diaphragm excursion, especially for the left hemidiaphragm. Muscle Nerve 55: 125-127, 2017. © 2016 Wiley Periodicals, Inc.

Effects of numerical dissipation and unphysical excursions on scalar-mixing estimates in large-eddy simulations

NASA Astrophysics Data System (ADS)

Sharan, Nek; Matheou, Georgios; Dimotakis, Paul

2017-11-01

Artificial numerical dissipation decreases dispersive oscillations and can play a key role in mitigating unphysical scalar excursions in large eddy simulations (LES). Its influence on scalar mixing can be assessed through the resolved-scale scalar, Z , its probability density function (PDF), variance, spectra, and the budget of the horizontally averaged equation for Z2. LES of incompressible temporally evolving shear flow enabled us to study the influence of numerical dissipation on unphysical scalar excursions and mixing estimates. Flows with different mixing behavior, with both marching and non-marching scalar PDFs, are studied. Scalar fields for each flow are compared for different grid resolutions and numerical scalar-convection term schemes. As expected, increasing numerical dissipation enhances scalar mixing in the development stage of shear flow characterized by organized large-scale pairings with a non-marching PDF, but has little influence in the self-similar stage of flows with marching PDFs. Flow parameters and regimes sensitive to numerical dissipation help identify approaches to mitigate unphysical excursions while minimizing dissipation.

Geomagnetic paleointensities from excursion sequences in lavas on Oahu, Hawaii

USGS Publications Warehouse

Coe, Robert S.; Gromme, Sherman; Mankinen, Edward A.

1984-01-01

Paleomagnetic data demonstrating three late Tertiary excursions in the direction of the geomagnetic field recorded in sequences of basaltic lavas on the island of Oahu, Hawaii were published by R. R. Doell and G. B. Dalrymple in 1973. We have determined geomagnetic paleointensities by the Thelliers' method for 14 lavas from the three sites. During these experiments, considerable difficulty was encountered because of the presence of titanomaghemite in many lavas and the contamination of natural remanent magnetization by lightning in many others. Moreover, we often observed the production of spurious high‐temperature chemical remanent magnetization during the Thellier experiments. An analysis of this particularly troublesome problem is presented. Two of the sites showed low paleointensities associated with angular departures of the paleomagnetic field direction from that of a geocentric axial dipole, which suggests that these excursions represent aborted reversals or fragments of reversals. At the third site, however, the paleointensity did not become low as the field diverged. This excursion may reflect the variation of a large nondipole source near Hawaii.

NASA CF6 jet engine diagnostics program: Long-term CF6-6D low-pressure turbine deterioration

NASA Technical Reports Server (NTRS)

Smith, J. J.

1979-01-01

Back-to-back performance tests were run on seven airline low pressure turbine (LPT) modules and four new CF6-6D modules. Back-to-back test cell runs, in which an airline LPT module was directly compared to a new production module, were included. The resulting change, measured in fuel burn, equaled the level of LPT module deterioration. Three of the LPT modules were analytically inspected followed by a back-to-back test cell run to evaluate current refurbishment techniques.

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (left) accompanies Executive Director of NASDA Koji Yamamoto (third from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (left) accompanies Executive Director of NASDA Koji Yamamoto (third from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

Illness and injury to students on a school excursion to Peru.

PubMed

Shaw, Marc T M; Harding, Elizabeth; Leggat, Peter A

2014-01-01

School-organized travels abroad provide an opportunity for students to undertake supervised travel that reinforces scholastic study of various geographical locations under the direction and protection of experienced tour leaders and health professional support. Little is known concerning the nature of illnesses and injuries occurring on overseas school excursions. This study was designed to investigate the prevalence of injury and illness suffered by older teenagers on a school excursion to South America. In 2010, the school's tour physician (EH) diagnosed and recorded all illnesses and injuries among 29 school girls and 6 accompanying adults on a school excursion to Peru. Information recorded included age, sex, the nature of the presenting illness, number of days into the tour, the assessment of the condition, and the treatment employed during the excursion's field phase of 21 days. A total of 32 (91%) travelers sought medical advice at least once for a total of 371 consultations, resulting in 153 separate diagnoses. The mean age of the students was 16 years with six adults accompanying the students being significantly older. Primary illnesses diagnosed were related to the following systems and conditions: gastrointestinal (58, 37%), respiratory (25, 16%), altitude sickness (19, 12%), genitourinary (8, 5%), dermatological (10, 7%), trauma (7, 5%), neurological (7, 5%), anxiety or psychological adjustment (7, 5%), adverse drug reactions (4, 3%), and musculoskeletal (5, 3%). The most commonly used medications were antidiarrheal and antiemetic medication. There were six accidents during the journey resulting in minor soft-tissue injuries. There were no deaths or other major accidents requiring emergency evacuation or hospitalization. On this school excursion, the health problems encountered were consistent with those reported for other specialized tours, including expeditions and premium tours, although altitude illness needs to be carefully planned for in tours to higher elevation destinations as in South America. As well as being part of the service provided to the school students, the inclusion of a physician with appropriate medical supplies for this tour increased the independence of the travel group. A proposed medical kit for such an excursion is presented. © 2014 International Society of Travel Medicine.

Occupant kinematics in low-speed frontal sled tests: Human volunteers, Hybrid III ATD, and PMHS.

PubMed

Beeman, Stephanie M; Kemper, Andrew R; Madigan, Michael L; Franck, Christopher T; Loftus, Stephen C

2012-07-01

A total of 34 dynamic matched frontal sled tests were performed, 17 low (2.5g, Δv=4.8kph) and 17 medium (5.0g, Δv=9.7kph), with five male human volunteers of approximately 50th percentile height and weight, a Hybrid III 50th percentile male ATD, and three male PMHS. Each volunteer was exposed to two impulses at each severity, one relaxed and one braced prior to the impulse. A total of four tests were performed at each severity with the ATD and one trial was performed at each severity with each PMHS. A Vicon motion analysis system, 12 MX-T20 2 megapixel cameras, was used to quantify subject 3D kinematics (±1mm) (1kHz). Excursions of select anatomical regions were normalized to their respective initial positions and compared by test condition and between subject types. The forward excursions of the select anatomical regions generally increased with increasing severity. The forward excursions of relaxed human volunteers were significantly larger than those of the ATD for nearly every region at both severities. The forward excursions of the upper body regions of the braced volunteers were generally significantly smaller than those of the ATD at both severities. Forward excursions of the relaxed human volunteers and PMHSs were fairly similar except the head CG response at both severities and the right knee and C7 at the medium severity. The forward excursions of the upper body of the PMHS were generally significantly larger than those of the braced volunteers at both severities. Forward excursions of the PMHSs exceeded those of the ATD for all regions at both severities with significant differences within the upper body regions. Overall human volunteers, ATD, and PMHSs do not have identical biomechanical responses in low-speed frontal sled tests but all contribute valuable data that can be used to refine and validate computational models and ATDs used to assess injury risk in automotive collisions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Determining the Accuracy of Paleomagnetic Remanence and High-Resolution Chronostratigraphy for Sedimentary Rocks using Rock Magnetics

NASA Astrophysics Data System (ADS)

Kodama, K. P.

2017-12-01

The talk will consider two broad topics in rock magnetism and paleomagnetism: the accuracy of paleomagnetic remanence and the use of rock magnetics to measure geologic time in sedimentary sequences. The accuracy of the inclination recorded by sedimentary rocks is crucial to paleogeographic reconstructions. Laboratory compaction experiments show that inclination shallows on the order of 10˚-15˚. Corrections to the inclination can be made using the effects of compaction on the directional distribution of secular variation recorded by sediments or the anisotropy of the magnetic grains carrying the ancient remanence. A summary of all the compaction correction studies as of 2012 shows that 85% of sedimentary rocks studied have enjoyed some amount of inclination shallowing. Future work should also consider the effect of grain-scale strain on paleomagnetic remanence. High resolution chronostratigraphy can be assigned to a sedimentary sequence using rock magnetics to detect astronomically-forced climate cycles. The power of the technique is relatively quick, non-destructive measurements, the objective identification of the cycles compared to facies interpretations, and the sensitivity of rock magnetics to subtle changes in sedimentary source. An example of this technique comes from using rock magnetics to identify astronomically-forced climate cycles in three globally distributed occurrences of the Shuram carbon isotope excursion. The Shuram excursion may record the oxidation of the world ocean in the Ediacaran, just before the Cambrian explosion of metazoans. Using rock magnetic cyclostratigraphy, the excursion is shown to have the same duration (8-9 Myr) in southern California, south China and south Australia. Magnetostratigraphy of the rocks carrying the excursion in California and Australia shows a reversed to normal geomagnetic field polarity transition at the excursion's nadir, thus supporting the synchroneity of the excursion globally. Both results point to a primary depositional origin for the excursion, and strengthens the argument for oxidation of the world ocean in the Ediacaran. Future work must learn how global climate is encoded by rock magnetics, but our work to date suggests that variations in continental run-off are detected by rock magnetics.

Japanese Experiment Module arrival

NASA Image and Video Library

2007-03-29

The Experiment Logistics Module Pressurized Section for the Japanese Experiment Module arrives at the Space Station Processing Facility. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

Japanese Experiment Module arrival

NASA Image and Video Library

2007-03-29

The Experiment Logistics Module Pressurized Section for the Japanese Experiment Module arrives at the Space Station Processing Facility for uncrating. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

Ventilation-Induced Modulation of Pulse Oximeter Waveforms: A Method for the Assessment of Early Changes in Intravascular Volume During Spinal Fusion Surgery in Pediatric Patients.

PubMed

Alian, Aymen A; Atteya, Gourg; Gaal, Dorothy; Golembeski, Thomas; Smith, Brian G; Dai, Feng; Silverman, David G; Shelley, Kirk

2016-08-01

Scoliosis surgery is often associated with substantial blood loss, requiring fluid resuscitation and blood transfusions. In adults, dynamic preload indices have been shown to be more reliable for guiding fluid resuscitation, but these indices have not been useful in children undergoing surgery. The aim of this study was to introduce frequency-analyzed photoplethysmogram (PPG) and arterial pressure waveform variables and to study the ability of these parameters to detect early bleeding in children during surgery. We studied 20 children undergoing spinal fusion. Electrocardiogram, arterial pressure, finger pulse oximetry (finger PPG), and airway pressure waveforms were analyzed using time domain and frequency domain methods of analysis. Frequency domain analysis consisted of calculating the amplitude density of PPG and arterial pressure waveforms at the respiratory and cardiac frequencies using Fourier analysis. This generated 2 measurements: The first is related to slow mean arterial pressure modulation induced by ventilation (also known as DC modulation when referring to the PPG), and the second corresponds to pulse pressure modulation (AC modulation or changes in the amplitude of pulse oximeter plethysmograph when referring to the PPG). Both PPG and arterial pressure measurements were divided by their respective cardiac pulse amplitude to generate DC% and AC% (normalized values). Standard hemodynamic data were also recorded. Data at baseline and after bleeding (estimated blood loss about 9% of blood volume) were presented as median and interquartile range and compared using Wilcoxon signed-rank tests; a Bonferroni-corrected P value <0.05 was considered statistically significant. There were significant increases in PPG DC% (median [interquartile range] = 359% [210 to 541], P = 0.002), PPG AC% (160% [87 to 251], P = 0.003), and arterial DC% (44% [19 to 84], P = 0.012) modulations, respectively, whereas arterial AC% modulations showed nonsignificant increase (41% [1 to 85], P = 0.12). The change in PPG DC% was significantly higher than that in PPG AC%, arterial DC%, arterial AC%, and systolic blood pressure with P values of 0.008, 0.002, 0.003, and 0.002, respectively. Only systolic blood pressure showed significant changes (11% [4 to 21], P = 0.003) between bleeding phase and baseline. Finger PPG and arterial waveform parameters (using frequency analysis) can track changes in blood volume during the bleeding phase, suggesting the potential for a noninvasive monitor for tracking changes in blood volume in pediatric patients. PPG waveform baseline modulation (PPG DC%) was more sensitive to changes in venous blood volume when compared with respiration-induced modulation seen in the arterial pressure waveform.

Invariance in the recurrence of large returns and the validation of models of price dynamics

NASA Astrophysics Data System (ADS)

Chang, Lo-Bin; Geman, Stuart; Hsieh, Fushing; Hwang, Chii-Ruey

2013-08-01

Starting from a robust, nonparametric definition of large returns (“excursions”), we study the statistics of their occurrences, focusing on the recurrence process. The empirical waiting-time distribution between excursions is remarkably invariant to year, stock, and scale (return interval). This invariance is related to self-similarity of the marginal distributions of returns, but the excursion waiting-time distribution is a function of the entire return process and not just its univariate probabilities. Generalized autoregressive conditional heteroskedasticity (GARCH) models, market-time transformations based on volume or trades, and generalized (Lévy) random-walk models all fail to fit the statistical structure of excursions.

The Walkback Test: A Study to Evaluate Suit and Life Support System Performance Requirements for a 10 Kilometer Traverse in a Planetary Suit

NASA Technical Reports Server (NTRS)

Vos, Jessica R.; Gernhardt, Michael L.; Lee, Lesley

2007-01-01

As planetary suit and planetary life support systems develop, specific design inputs for each system relate to a presently unanswered question concerning operational concepts: What distance can be considered a safe walking distance for a suited EVA crew member exploring the surface of the Moon to "walk-back" to the habitat in the event of a rover breakdown, taking into consideration the planned EVA tasks as well as the possible traverse back to the habitat? It has been assumed, based on Apollo program experience, that 10 kilometers (6.2 mi) will be the maximum EVA excursion distance from the lander or habitat to ensure the crew member s safe return to the habitat in the event of a rover failure. To investigate the feasibility of performing a suited 10 km Walkback, NASA-JSC assembled a multi-disciplinary team to design and implement the Lunar Walkback Test . The test was designed not only to determine the feasibility of a 10 km excursion, but also to collect human performance, biomedical, and biomechanical data relevant to optimizing space suit design and life support system sizing. These data will also be used to develop follow-on studies to understand interrelationships of such key parameters as suit mass, inertia, suit pressure, and center of gravity (CG), and the respective influences of each on human performance.

ORION - Crew Module Side Hatch: Proof Pressure Test Anomaly Investigation

NASA Technical Reports Server (NTRS)

Evernden, Brent A.; Guzman, Oscar J.

2018-01-01

The Orion Multi-Purpose Crew Vehicle program was performing a proof pressure test on an engineering development unit (EDU) of the Orion Crew Module Side Hatch (CMSH) assembly. The purpose of the proof test was to demonstrate structural capability, with margin, at 1.5 times the maximum design pressure, before integrating the CMSH to the Orion Crew Module structural test article for subsequent pressure testing. The pressure test was performed at lower pressures of 3 psig, 10 psig and 15.75 psig with no apparent abnormal behavior or leaking. During pressurization to proof pressure of 23.32 psig, a loud 'pop' was heard at 21.3 psig. Upon review into the test cell, it was noted that the hatch had prematurely separated from the proof test fixture, thus immediately ending the test. The proof pressure test was expected be a simple verification but has since evolved into a significant joint failure investigation from both Lockheed Martin and NASA.

Immediate Effects of a Single Session of Motor Skill Training on the Lumbar Movement Pattern During a Functional Activity in People With Low Back Pain: A Repeated-Measures Study.

PubMed

Marich, Andrej V; Lanier, Vanessa M; Salsich, Gretchen B; Lang, Catherine E; Van Dillen, Linda R

2018-04-06

People with low back pain (LBP) may display an altered lumbar movement pattern of early lumbar motion compared to people with healthy backs. Modifying this movement pattern during a clinical test decreases pain. It is unknown whether similar effects would be seen during a functional activity. The objective of this study is was to examine the lumbar movement patterns before and after motor skill training, effects on pain, and characteristics that influenced the ability to modify movement patterns. The design consisted of a repeated-measures study examining early-phase lumbar excursion in people with LBP during a functional activity test. Twenty-six people with chronic LBP received motor skill training, and 16 people with healthy backs were recruited as a reference standard. Twenty minutes of motor skill training to decrease early-phase lumbar excursion during the performance of a functional activity were used as a treatment intervention. Early-phase lumbar excursion was measured before and after training. Participants verbally reported increased pain, decreased pain, or no change in pain during performance of the functional activity test movement in relation to their baseline pain. The characteristics of people with LBP that influenced the ability to decrease early-phase lumbar excursion were examined. People with LBP displayed greater early-phase lumbar excursion before training than people with healthy backs (LBP: mean = 11.2°, 95% CI = 9.3°-13.1°; healthy backs: mean = 7.1°, 95% CI = 5.8°-8.4°). Following training, the LBP group showed a decrease in the amount of early-phase lumbar excursion (mean change = 4.1°, 95% CI = 2.4°-5.8°); 91% of people with LBP reported that their pain decreased from baseline following training. The longer the duration of LBP (β = - 0.22) and the more early-phase lumbar excursion before training (β = - 0.82), the greater the change in early-phase lumbar excursion following training. The long-term implications of modifying the movement pattern and whether the decrease in pain attained was clinically significant are unknown. People with LBP were able to modify their lumbar movement pattern and decrease their pain with the movement pattern within a single session of motor skill training.

Engaging students in research learning experiences through hydrology field excursions and short films

NASA Astrophysics Data System (ADS)

Ewen, Tracy; Seibert, Jan

2015-04-01

One of the best ways to engage students and instill enthusiasm for hydrology is to expose them to hands-on learning. A focus on hydrology field research can be used to develop context-rich and active learning, and help solidify idealized learning where students are introduced to individual processes through textbook examples, often neglecting process interactions and an appreciation for the complexity of the system. We introduced a field course where hydrological measurement techniques are used to study processes such as snow hydrology and runoff generation, while also introducing students to field research and design of their own field project. Additionally, we produced short films of each of these research-based field excursions, with in-house film expertise. These films present a short overview of field methods applied in alpine regions and will be used for our larger introductory hydrology courses, exposing students to field research at an early stage, and for outreach activities, including for potential high school students curious about hydrology. In the field course, students design a low-budget experiment with the aim of going through the different steps of a 'real' scientific project, from formulating the research question to presenting their results. During the field excursions, students make discharge measurements in several alpine streams with a salt tracer to better understand the spatial characteristics of an alpine catchment, where source waters originate and how they contribute to runoff generation. Soil moisture measurements taken by students in this field excursion were used to analyze spatial soil moisture patterns in the alpine catchment and subsequently used in a publication. Another field excursion repeats a published experiment, where preferential soil flow paths are studied using a tracer and compared to previously collected data. For each field excursion, observational data collected by the students is uploaded to an online database we developed, where students can also retrieve data from past excursions to further analyze and compare their data. At each of the field sites, weather stations were installed and a webviewer allows access to realtime data from data loggers, allowing students to explore how processes relate to climatic conditions. Together, these field excursions give students the necessary tools they will need to carry out field research of their own in future projects, whether in academia or industry, while the short films give potential or first-year students an impression of what hydrology is all about and hopefully inspire them to become future hydrologists.

A gaussian model for simulated geomagnetic field reversals

NASA Astrophysics Data System (ADS)

Wicht, Johannes; Meduri, Domenico G.

2016-10-01

Field reversals are the most spectacular events in the geomagnetic history but remain little understood. Here we explore the dipole behaviour in particularly long numerical dynamo simulations to reveal statistically significant conditions required for reversals and excursions to happen. We find that changes in the axial dipole moment behaviour are crucial while the equatorial dipole moment plays a negligible role. For small Rayleigh numbers, the axial dipole always remains strong and stable and obeys a clearly Gaussian probability distribution. Only when the Rayleigh number is increased sufficiently the axial dipole can reverse and its distribution becomes decisively non-Gaussian. Increased likelihoods around zero indicate a pronounced lingering in a new low dipole moment state. Reversals and excursions can only happen when axial dipole fluctuations are large enough to drive the system from the high dipole moment state assumed during stable polarity epochs into the low dipole moment state. Since it is just a matter of chance which polarity is amplified during dipole recovery, reversals and grand excursions, i.e. excursions during which the dipole assumes reverse polarity, are equally likely. While the overall reversal behaviour seems Earth-like, a closer comparison to palaeomagnetic findings suggests that the simulated events last too long and that grand excursions are too rare. For a particularly large Ekman number we find a second but less Earth-like type of reversals where the total field decays and recovers after a certain time.

Influence of hip and knee osteoarthritis on dynamic postural control parameters among older fallers.

PubMed

Mat, Sumaiyah; Ng, Chin Teck; Tan, Maw Pin

2017-03-06

To compare the relationship between postural control and knee and hip osteoarthritis in older adults with and without a history of falls. Fallers were those with ≥ 2 falls or 1 injurious fall over 12 months. Non-fallers were volunteers with no falls in the past year. Radiological evidence of osteoarthritis with no reported symptoms was considered "asymptomatic osteoarthritis", while "symptomatic osteoarthritis" was defined as radiographic osteoarthritis with pain or stiffness. Dynamic postural control was quantified with the limits of stability test measured on a balance platform (Neurocom® Balancemaster, California, USA). Parameters assessed were end-point excursion, maximal excursion, and directional control. A total of 102 older individuals, mean age 73 years (standard deviation 5.7) years were included. The association between falls and poor performance in maximal excursion and directional control was confounded by age and comorbidities. In the same linear equation model with falls, symptomatic osteoarthritis remained independently associated with poor end-point excursion (β-coefficient (95% confidence interval) -6.80 (-12.14 to -1.42)). Poor performance in dynamic postural control (maximal excursion and directional control) among fallers was not accounted for by hip/knee osteoarthritis, but was confounded by old age and comorbidities. Loss of postural control due to hip/knee osteoarthritis is not a risk factor for falls among community-dwelling older adults.

Carbon isotopic shift and its cause at the Wuchiapingian-Changhsingian boundary in the Upper Permian at the Zhaojiaba section, South China: Evidences from multiple geochemical proxies

NASA Astrophysics Data System (ADS)

Wei, Hengye; Yu, Hao; Wang, Jianguo; Qiu, Zhen; Xiang, Lei; Shi, Guo

2015-06-01

The Late Permian environmental change, connecting the Guadalupian-Lopingian (G-L) (Middle-Upper Permian) boundary mass extinction and the Permain-Triassic (P-Tr) boundary mass extinction, has attracted more and more attentions. A significant negative shift for carbon isotope had been found at the Wuchiapingian-Changhsingian (W-C) boundary in the Upper Permian recently. However, the cause(s) of this negative excursion is still unknown. To resolve this problem, we analyzed the bulk organic carbon isotope, total organic carbon (TOC) content, pyritic sulfur (Spy) content, major element concentrations, and molecular organic biomarkers in the Wujiaping and Dalong formations in the Upper Permian from the Zhaojiaba section in western Hubei province, South China. Our results show that (1) there was a significant negative excursion in organic carbon isotopes at the W-C boundary and again a negative excursion at the top of Changhsingian stage; (2) the significant negative excursion at the W-C boundary was probably a global signal and mainly caused by the low primary productivity; and (3) the negative carbon isotope excursion at the top of Changhsingian was probably caused by the Siberian Traps eruptions. A decline in oceanic primary productivity at the W-C boundary probably represents a disturbance of the marine food web, leading to a vulnerable ecosystem prior to the P-Tr boundary mass extinction.

Outcome of a graduated minimally invasive facial reanimation in patients with facial paralysis.

PubMed

Holtmann, Laura C; Eckstein, Anja; Stähr, Kerstin; Xing, Minzhi; Lang, Stephan; Mattheis, Stefan

2017-08-01

Peripheral paralysis of the facial nerve is the most frequent of all cranial nerve disorders. Despite advances in facial surgery, the functional and aesthetic reconstruction of a paralyzed face remains a challenge. Graduated minimally invasive facial reanimation is based on a modular principle. According to the patients' needs, precondition, and expectations, the following modules can be performed: temporalis muscle transposition and facelift, nasal valve suspension, endoscopic brow lift, and eyelid reconstruction. Applying a concept of a graduated minimally invasive facial reanimation may help minimize surgical trauma and reduce morbidity. Twenty patients underwent a graduated minimally invasive facial reanimation. A retrospective chart review was performed with a follow-up examination between 1 and 8 months after surgery. The FACEgram software was used to calculate pre- and postoperative eyelid closure, the level of brows, nasal, and philtral symmetry as well as oral commissure position at rest and oral commissure excursion with smile. As a patient-oriented outcome parameter, the Glasgow Benefit Inventory questionnaire was applied. There was a statistically significant improvement in the postoperative score of eyelid closure, brow asymmetry, nasal asymmetry, philtral asymmetry as well as oral commissure symmetry at rest (p < 0.05). Smile evaluation revealed no significant change of oral commissure excursion. The mean Glasgow Benefit Inventory score indicated substantial improvement in patients' overall quality of life. If a primary facial nerve repair or microneurovascular tissue transfer cannot be applied, graduated minimally invasive facial reanimation is a promising option to restore facial function and symmetry at rest.

KENNEDY SPACE CENTER, FLA. - Members of the STS-114 crew take a look at the Japanese Experiment Module (JEM) pressure module in the Space Station Processing Facility. A research laboratory, the pressurized module is the first element of the JEM, named "Kibo" (Hope), to be delivered to KSC. The National Space Development Agency of Japan (NASDA) developed the laboratory at the Tsukuba Space Center near Tokyo and is Japan's primary contribution to the Station. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

NASA Image and Video Library

2003-06-09

KENNEDY SPACE CENTER, FLA. - Members of the STS-114 crew take a look at the Japanese Experiment Module (JEM) pressure module in the Space Station Processing Facility. A research laboratory, the pressurized module is the first element of the JEM, named "Kibo" (Hope), to be delivered to KSC. The National Space Development Agency of Japan (NASDA) developed the laboratory at the Tsukuba Space Center near Tokyo and is Japan's primary contribution to the Station. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

Gemini Rendezvous Docking Simulator

NASA Image and Video Library

1964-05-11

Gemini Rendezvous Docking Simulator suspended from the roof of the Langley Research Center s aircraft hangar. Francis B. Smith wrote: The rendezvous and docking operation of the Gemini spacecraft with the Agena and of the Apollo Command Module with the Lunar Excursion Module have been the subject of simulator studies for several years. This figure illustrates the Gemini-Agena rendezvous docking simulator at Langley. The Gemini spacecraft was supported in a gimbal system by an overhead crane and gantry arrangement which provided 6 degrees of freedom - roll, pitch, yaw, and translation in any direction - all controllable by the astronaut in the spacecraft. Here again the controls fed into a computer which in turn provided an input to the servos driving the spacecraft so that it responded to control motions in a manner which accurately simulated the Gemini spacecraft. -- Published in Barton C. Hacker and James M. Grimwood, On the Shoulders of Titans: A History of Project Gemini, NASA SP-4203 Francis B. Smith, Simulators for Manned Space Research, Paper presented at the 1966 IEEE International convention, March 21-25, 1966.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility can be seen the U.S. Node 2 (at left) and the Japanese Experiment Module (JEM)’s Pressurized Module (at right). The Italian-built Node 2, the second of three Space Station connecting modules, attaches to the end of the U.S. Lab and will provide attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet. The Pressurized Module is the first element of the JEM to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

NASA Image and Video Library

2003-08-12

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility can be seen the U.S. Node 2 (at left) and the Japanese Experiment Module (JEM)’s Pressurized Module (at right). The Italian-built Node 2, the second of three Space Station connecting modules, attaches to the end of the U.S. Lab and will provide attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and, later, Multipurpose Logistics Modules. It will provide the primary docking location for the Shuttle when a pressurized mating adapter is attached to Node 2. Installation of the module will complete the U.S. Core of the ISS. Node 2 is the designated payload for mission STS-120. No orbiter or launch date has been determined yet. The Pressurized Module is the first element of the JEM to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

Tongue Pressure Modulation during Swallowing: Water versus Nectar-Thick Liquids

ERIC Educational Resources Information Center

Steele, Catriona M.; Bailey, Gemma L.; Molfenter, Sonja M.

2010-01-01

Purpose: Evidence of tongue-palate pressure modulation during swallowing between thin and nectar-thick liquids stimuli has been equivocal. This mirrors a lack of clear evidence in the literature of tongue and hyoid movement modulation between nectar-thick and thin liquid swallows. In the current investigation, the authors sought to confirm whether…

46 CFR 176.204 - Permit to carry excursion party.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., survival craft, life jacket, fire safety, and manning standards applicable to a vessel in the service for... may carry, the crew required, any additional lifesaving or safety equipment required, the route for... waive the applicable minimum safety standards when issuing an excursion permit. In particular, a vessel...

46 CFR 176.204 - Permit to carry excursion party.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., survival craft, life jacket, fire safety, and manning standards applicable to a vessel in the service for... may carry, the crew required, any additional lifesaving or safety equipment required, the route for... waive the applicable minimum safety standards when issuing an excursion permit. In particular, a vessel...

46 CFR 176.204 - Permit to carry excursion party.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., survival craft, life jacket, fire safety, and manning standards applicable to a vessel in the service for... may carry, the crew required, any additional lifesaving or safety equipment required, the route for... waive the applicable minimum safety standards when issuing an excursion permit. In particular, a vessel...

40 CFR 63.1334 - Parameter monitoring levels and excursions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... period for the storage vessel. (ii) If the monitoring plan does not specify monitoring a parameter and... semiannually or quarterly. The first semiannual period is the 6-month period starting the date the Notification... period—two excused excursions. (6) For the sixth and all subsequent semiannual periods—one excused...

Subject-Specific Modeling of Muscle Force and Knee Contact in Total Knee Arthroplasty

PubMed Central

Navacchia, Alessandro; Rullkoetter, Paul J.; Schütz, Pascal; List, Renate B.; Fitzpatrick, Clare K.; Shelburne, Kevin B.

2017-01-01

Understanding the mechanical loading environment and resulting joint mechanics for activities of daily living in total knee arthroplasty is essential to continuous improvement in implant design. Although survivorship of these devices is good, a substantial number of patients report dissatisfaction with the outcome of their procedure. Knowledge of in vivo kinematics and joint loading will enable improvement in preclinical assessment and refinement of implant geometry. The purpose of this investigation was to describe the mechanics of total knee arthroplasty during a variety of activities of daily living (gait, walking down stairs, and chair rise/sit). Estimates of muscle forces, tibial contact load, location, and pressure distribution was performed through a combination of mobile fluoroscopy data collection, musculoskeletal modeling, and finite element simulation. For the activities evaluated, joint compressive load was greatest during walking down stairs; however, the highest contact pressure occurred during chair rise/sit. The joint contact moment in the frontal plane was mainly varus for gait and walking down stairs, while it was valgus during chair rise/sit. Excursion of the center of pressure on the tibial component was similar during each activity and between the medial and lateral sides. The main determinants of center of pressure location were internal–external rotation, joint load, and tibial insert conformity. PMID:26792665

Experimental investigation of a spiral-wound pressure-retarded osmosis membrane module for osmotic power generation.

PubMed

Kim, Yu Chang; Kim, Young; Oh, Dongwook; Lee, Kong Hoon

2013-03-19

Pressure-retarded osmosis (PRO) uses a semipermeable membrane to produce renewable energy from salinity-gradient energy. A spiral-wound (SW) design is one module configuration of the PRO membrane. The SW PRO membrane module has two different flow paths, axial and spiral, and two different spacers, net and tricot, for draw- and feed-solution streams, respectively. This study used an experimental approach to investigate the relationship between two interacting flow streams in a prototype SW PRO membrane module, and the adverse impact of a tricot fabric spacer (as a feed spacer) on the PRO performance, including water flux and power density. The presence of the tricot spacer inside the membrane envelope caused a pressure drop due to flow resistance and reduced osmotic water permeation due to the shadow effect. The dilution of the draw solution by water permeation resulted in the reduction of the osmotic pressure difference along a pressure vessel. For a 0.6 M NaCl solution and tap water, the water flux and corresponding maximum power density were 3.7 L m(-2)h(-1) and 1.0 W/m(2) respectively at a hydraulic pressure difference of 9.8 bar. The thickness and porosity of the tricot spacer should be optimized to achieve high SW PRO module performance.

High Pressure Angle Gears: Comparison to Typical Gear Designs

NASA Technical Reports Server (NTRS)

Handschuh, Robert F.; Zabrajsek, Andrew J.

2010-01-01

A preliminary study has been completed to determine the feasibility of using high-pressure angle gears in aeronautic and space applications. Tests were conducted in the NASA Glenn Research Center (GRC) Spur Gear Test Facility at speeds up to 10,000 rpm and 73 N*m (648 in.*lb) for 3.18, 2.12, and 1.59 module gears (8, 12, and 16 diametral pitch gears), all designed to operate in the same test facility. The 3.18 module (8-diametral pitch), 28 tooth, 20deg pressure angle gears are the GRC baseline test specimen. Also, 2.12 module (12-diametral pitch), 42 tooth, 25deg pressure angle gears were tested. Finally 1.59 module (16-diametral pitch), 56 tooth, 35deg pressure angle gears were tested. The high-pressure angle gears were the most efficient when operated in the high-speed aerospace mode (10,000 rpm, lubricated with a synthetic turbine engine oil), and produced the lowest wear rates when tested with a perfluoroether-based grease. The grease tests were conducted at 150 rpm and 71 N*m (630 in.*lb).

KSC-07pd0898

NASA Image and Video Library

2007-04-17

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, Scott Higginbotham, payload manager for the International Space Station, stands in front of the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module. The module will be delivered to the space station on mission STS-123. Earlier, NASA and Japanese Aerospace and Exploration Agency (JAXA) officials welcomed the arrival of the logistics module. The module will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (second from left) accompanies Executive Director of NASDA Koji Yamamoto (fourth from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (second from left) accompanies Executive Director of NASDA Koji Yamamoto (fourth from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

ULF Generation by Modulated Ionospheric Heating

NASA Astrophysics Data System (ADS)

Chang, C.; Labenski, J.; Wallace, T.; Papadopoulos, K.

2013-12-01

Modulated ionospheric heating experiments designed to generate ULF waves using the HAARP heater have been conducted since 2007. Artificial ULF waves in the Pc1 frequency range were observed from space and by ground induction magnetometers located in the vicinity of the heater as well as at long distances. Two distinct generation mechanisms of artificial ULF waves were identified. The first was electroject modulation under geomagnetically disturbed conditions. The second was pressure modulation in the E and F regions of the ionosphere under quiet conditions. Ground detections of ULF waves near the heater included both Shear Alfven waves and Magnetosonic waves generated by electrojet and/or pressure modulations. Distant ULF detections involved Magnetosonic wave propagation in the Alfvenic duct with pressure modulation as the most likely source. Summary of our observations and theoretical interpretations will be presented at the meeting. We would like to acknowledge the support provided by the staff at the HAARP facility during our ULF experiments.

Fluid pumping apparatus

DOEpatents

West, Phillip B.

2006-01-17

A method and apparatus suitable for coupling seismic or other downhole sensors to a borehole wall in high temperature and pressure environments. In one embodiment, one or more metal bellows mounted to a sensor module are inflated to clamp the sensor module within the borehole and couple an associated seismic sensor to a borehole wall. Once the sensing operation is complete, the bellows are deflated and the sensor module is unclamped by deflation of the metal bellows. In a further embodiment, a magnetic drive pump in a pump module is used to supply fluid pressure for inflating the metal bellows using borehole fluid or fluid from a reservoir. The pump includes a magnetic drive motor configured with a rotor assembly to be exposed to borehole fluid pressure including a rotatable armature for driving an impeller and an associated coil under control of electronics isolated from borehole pressure.

Liners for ion transport membrane systems

DOEpatents

Carolan, Michael Francis; Miller, Christopher Francis

2010-08-10

Ion transport membrane system comprising (a) a pressure vessel comprising an interior, an exterior, an inlet, an inlet conduit, an outlet, and an outlet conduit; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region, wherein the inlet and the outlet of the pressure vessel are in flow communication with exterior regions of the membrane modules; (c) a gas manifold having an interior surface wherein the gas manifold is in flow communication with the interior region of each of the planar ion transport membrane modules and with the exterior of the pressure vessel; and (d) a liner disposed within any of the inlet conduit, the outlet conduit, and the interior surface of the gas manifold.

Delayed Compensatory Postural Adjustments After Lateral Perturbations Contribute to the Reduced Ability of Older Adults to Control Body Balance.

PubMed

Claudino, Renato; Dos Santos, Marcio José; Mazo, Giovana Zarpellon

2017-10-01

The goal of this study was to investigate the timing of compensatory postural adjustments in older adults during body perturbations in the mediolateral direction, circumstances that increase their risk of falls. The latencies of leg and trunk muscle activation to body perturbations at the shoulder level and variables of center of pressure excursion, which characterize postural stability, were analyzed in 40 older adults (nonfallers and fallers evenly split) and in 20 young participants. The older adults exhibited longer latencies of muscular activation in eight out of 15 postural muscles as compared with young participants; for three muscles, the latencies were longer for the older fallers than nonfallers. Simultaneously, the time for the center of pressure displacement reached its peak after the perturbation was significant longer in both groups of older adults. The observed delays in compensatory postural adjustments may affect the older adults' ability to prompt control body balance after postural disturbances and predispose them to falls.

Effects of utterance length and vocal loudness on speech breathing in older adults.

PubMed

Huber, Jessica E

2008-12-31

Age-related reductions in pulmonary elastic recoil and respiratory muscle strength can affect how older adults generate subglottal pressure required for speech production. The present study examined age-related changes in speech breathing by manipulating utterance length and loudness during a connected speech task (monologue). Twenty-three older adults and twenty-eight young adults produced a monologue at comfortable loudness and pitch and with multi-talker babble noise playing in the room to elicit louder speech. Dependent variables included sound pressure level, speech rate, and lung volume initiation, termination, and excursion. Older adults produced shorter utterances than young adults overall. Age-related effects were larger for longer utterances. Older adults demonstrated very different lung volume adjustments for loud speech than young adults. These results suggest that older adults have a more difficult time when the speech system is being taxed by both utterance length and loudness. The data were consistent with the hypothesis that both young and older adults use utterance length in premotor speech planning processes.

Fluid viscosity affects the fragmentation and inertial cavitation threshold of lipid encapsulated microbubbles

PubMed Central

Helfield, Brandon; Black, John J.; Qin, Bin; Pacella, John; Chen, Xucai; Villanueva, Flordeliza S.

2015-01-01

Ultrasound and microbubble optimization studies for therapeutic applications are often conducted in water/saline, with a fluid viscosity of 1 cP. In an in vivo context, microbubbles are situated in blood, a more viscous fluid (~4 cP). In this study, ultra-high speed microscopy and passive cavitation approaches were employed to investigate the effect of fluid viscosity on microbubble behavior at 1 MHz subject to high pressures (0.25 – 2 MPa). The propensity for individual microbubble (n=220) fragmentation was shown to significantly decrease in 4 cP fluid as compared to 1 cP fluid, despite achieving similar maximum radial excursions. Microbubble populations diluted in 4 cP fluid exhibited decreased wideband emissions (up to 10.2 times), and increasingly distinct harmonic emission peaks (e.g. ultraharmonic) with increasing pressure as compared to 1 cP fluid. These results suggest that in vitro studies should consider an evaluation using physiologic viscosity perfusate before transitioning to in vivo evaluations. PMID:26674676

System Measures Pressures Aboard A Compressor Rotor

NASA Technical Reports Server (NTRS)

Freedman, Robert J.; Senyitko, Richard G.; Blumenthal, Philip Z.

1994-01-01

Rotating pressure-measuring instrumentation includes on-board calibration standard. Computer-controlled, multichannel instrumentation system acquires pressure measurements from sensors mounted in 1.52-m-diameter rotor of compressor. Includes 5 miniature, electronically scanned pressure (ESP) modules, each containing 48 piezoresistive pressure sensors, pneumatic calibration valve, and electronic circuits for addressing and amplifying output of each sensor. Modules mounted on centerline of rotor, on instrumentation tower located inside nose cone of rotor. Subsystem designed to convert analog signal to distinct frequency without significantly affecting accuracy.

Modular robot

DOEpatents

Ferrante, Todd A.

1997-01-01

A modular robot may comprise a main body having a structure defined by a plurality of stackable modules. The stackable modules may comprise a manifold, a valve module, and a control module. The manifold may comprise a top surface and a bottom surface having a plurality of fluid passages contained therein, at least one of the plurality of fluid passages terminating in a valve port located on the bottom surface of the manifold. The valve module is removably connected to the manifold and selectively fluidically connects the plurality of fluid passages contained in the manifold to a supply of pressurized fluid and to a vent. The control module is removably connected to the valve module and actuates the valve module to selectively control a flow of pressurized fluid through different ones of the plurality of fluid passages in the manifold. The manifold, valve module, and control module are mounted together in a sandwich-like manner and comprise a main body. A plurality of leg assemblies are removably connected to the main body and are removably fluidically connected to the fluid passages in the manifold so that each of the leg assemblies can be selectively actuated by the flow of pressurized fluid in different ones of the plurality of fluid passages in the manifold.

Influence of the wetting state of a heated surface on heat transfer and pressure loss in an evaporator tube

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

Koehler, W; Hein, D

1986-09-01

The influence of the wetting state of a heated surface on heat transfer and pressure loss in an evaporator tube was investigated for a parameter range occurring in fossil-fired steam generators. Included in the analysis are quantities which determine the wetting state in steady and transient flow. The experimental work consists of the following: Occurrence of critical heat flux (CHF) and post-CHF heat transfer in a vertical upflow evaporator tube; influence of pressure and enthalpy transients on heat transfer in the unwetted region; influence of pipe orientation on heat transfer; and two phase flow pressure loss in wetted and unwettedmore » region. Based on these experiments a method of predicting CHF for a vertical upflow evaporator tube was developed. The heat transfer in the unwetted region was newly formulated taking into account thermal nonequilibrium between the water and steam phases. Wall temperature excursions during pressure and enthalpy transients are interpreted with the help of the boiling curve and the Leidenfrost phenomenon. A method is developed by means of which it is possible to determine the influence of the pipe orientation on the location of the boiling crisis as well as on the heat transfer in the unwetted region. The influence of the wetting state of the heated surface on the two phase flow pressure loss is interpreted as ''Wall effect'' and is calculated using a simplified computer model. 68 refs., 83 figs.« less

Continuously phase-modulated standing surface acoustic waves for separation of particles and cells in microfluidic channels containing multiple pressure nodes

NASA Astrophysics Data System (ADS)

Lee, Junseok; Rhyou, Chanryeol; Kang, Byungjun; Lee, Hyungsuk

2017-04-01

This paper describes continuously phase-modulated standing surface acoustic waves (CPM-SSAW) and its application for particle separation in multiple pressure nodes. A linear change of phase in CPM-SSAW applies a force to particles whose magnitude depends on their size and contrast factors. During continuous phase modulation, we demonstrate that particles with a target dimension are translated in the direction of moving pressure nodes, whereas smaller particles show oscillatory movements. The rate of phase modulation is optimized for separation of target particles from the relationship between mean particle velocity and period of oscillation. The developed technique is applied to separate particles of a target dimension from the particle mixture. Furthermore, we also demonstrate human keratinocyte cells can be separated in the cell and bead mixture. The separation technique is incorporated with a microfluidic channel spanning multiple pressure nodes, which is advantageous over separation in a single pressure node in terms of throughput.

Pressure modulation algorithm to separate cerebral hemodynamic signals from extracerebral artifacts

PubMed Central

Baker, Wesley B.; Parthasarathy, Ashwin B.; Ko, Tiffany S.; Busch, David R.; Abramson, Kenneth; Tzeng, Shih-Yu; Mesquita, Rickson C.; Durduran, Turgut; Greenberg, Joel H.; Kung, David K.; Yodh, Arjun G.

2015-01-01

Abstract. We introduce and validate a pressure measurement paradigm that reduces extracerebral contamination from superficial tissues in optical monitoring of cerebral blood flow with diffuse correlation spectroscopy (DCS). The scheme determines subject-specific contributions of extracerebral and cerebral tissues to the DCS signal by utilizing probe pressure modulation to induce variations in extracerebral blood flow. For analysis, the head is modeled as a two-layer medium and is probed with long and short source-detector separations. Then a combination of pressure modulation and a modified Beer-Lambert law for flow enables experimenters to linearly relate differential DCS signals to cerebral and extracerebral blood flow variation without a priori anatomical information. We demonstrate the algorithm’s ability to isolate cerebral blood flow during a finger-tapping task and during graded scalp ischemia in healthy adults. Finally, we adapt the pressure modulation algorithm to ameliorate extracerebral contamination in monitoring of cerebral blood oxygenation and blood volume by near-infrared spectroscopy. PMID:26301255

The Hirnantian δ13C Positive Excursion in the Nabiullino Section (South Urals)

NASA Astrophysics Data System (ADS)

Yakupov, R. R.; Mavrinskaya, T. M.; Smoleva, I. V.

2018-02-01

The upper Sandbian, Katian, and Hirnantian complexes of conodonts in the upper Ordovician section of the western slope of the Southern Urals near the village of Nabiullino were studied. The δ13C positive excursion with a maximum of 3.3‰ associated with the global Hirnantian isotopic event, HICE, was fixed for the first time. This excursion shows the beginning of the Hirnantian stage in the terrigenous-carbonate section of the upper Ordovician in the Southern Urals. It coincides with the first occurrence of the Hirnantian conodont species of Gamachignathus ensifer and the conodonts of shallow-water biophacies, Aphelognathus-Ozarkodina, reflecting the global glacio-eustatic event.

KSC-07pd0902

NASA Image and Video Library

2007-04-17

KENNEDY SPACE CENTER, FLA. -- The Experiment Logistics Module Pressurized Section of the Japanese Experiment Module sits on top of a stand in the Space Station Processing Facility. Earlier, NASA and Japanese Space Agency (JAXA) officials welcomed the arrival of the logistics module, which will be delivered to the space station on mission STS-123. The module will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module. Photo credit: NASA/George Shelton

KSC-07pd0901

NASA Image and Video Library

2007-04-17

KENNEDY SPACE CENTER, FLA. -- After a welcoming ceremony for the Experiment Logistics Module Pressurized Section of the Japanese Experiment Module, STS-123 Commander Dominic Gorie talks to the media. Earlier, NASA and Japanese Space Agency (JAXA) officials welcomed the arrival of the logistics module, which will be delivered to the space station on mission STS-123. The module will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module. Photo credit: NASA/George Shelton

KSC-07pd0899

NASA Image and Video Library

2007-04-17

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, Scott Higginbotham and Chuong Nguyen, payload manager and deputy payload manager respectively for the International Space Station, stand in front of the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module. Earlier, NASA and Japanese Aerospace and Exploration Agency (JAXA) officials welcomed the arrival of the logistics module. The module will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module. Photo credit: NASA/George Shelton

Liquid jet response to internal modulated ultrasonic radiation pressure and stimulated drop production.

PubMed

Lonzaga, Joel B; Osterhoudt, Curtis F; Thiessen, David B; Marston, Philip L

2007-06-01

Experimental evidence shows that a liquid jet in air is an acoustic waveguide having a cutoff frequency inversely proportional to the jet diameter. Ultrasound applied to the jet supply liquid can propagate within the jet when the acoustic frequency is near to or above the cutoff frequency. Modulated radiation pressure is used to stimulate large amplitude deformations and the breakup of the jet into drops. The jet response to the modulated internal ultrasonic radiation pressure was monitored along the jet using (a) an optical extinction method and (b) images captured by a video camera. The jet profile oscillates at the frequency of the radiation pressure modulation and where the response is small, the amplitude was found to increase in proportion to the square of the acoustic pressure amplitude as previously demonstrated for oscillating drops [P.L. Marston and R.E. Apfel, J. Acoust. Soc. Am. 67, 27-37 (1980)]. Small amplitude deformations initially grow approximately exponentially with axial distance along the jet. Though aspects of the perturbation growth can be approximated from Rayleigh's analysis of the capillary instability, some detailed features of the observed jet response to modulated ultrasound are unexplained neglecting the effects of gravity.

Validation of the SunTech Medical Advantage Model 2 Series Automated Blood Pressure Module in Pregnancy.

PubMed

Kuper, Spencer G; Dotson, Kristin N; Anderson, Sarah B; Harris, Stacy L; Harper, Lorie M; Tita, Alan T

2018-06-15

 We sought to validate the SunTech Medical Advantage Model 2 Series with firmware LX 3.40.8 algorithm noninvasive blood pressure module in a pregnant population, including those with preeclampsia.  Validation study of an oscillometric noninvasive blood pressure module using the ANSI/AAMI ISO 81060-2:2013 standard guidelines. Pregnant women were enrolled into three subgroups: normotensive, hypertensive without proteinuria, and preeclampsia (hypertensive with random protein-to-creatinine ratio ≥ 0.3 or a 24-hour urine protein > 300 mg). Two trained research nurses, blinded to each other's measurements, used a mercury sphygmomanometer to validate the module by following the protocol set forth in the ANSI/AAMI ISO 81060-2:2013 standard guidelines.  A total of 45 patients, 15 in each subgroup, were included. The mean systolic and diastolic differences with standard deviations between the module and the mean observers' measurements for all participants were -2.3 ± 7.3 and 0.2 ± 6.5 mm Hg, respectively. The systolic and diastolic standard deviations of the mean of the individual patient's paired module and observers' measurements were 6.27 and 5.98 mm Hg, respectively. The test device, relative to a mercury sphygmomanometer, underestimated the systolic blood pressure in patients with preeclampsia by at least 10 mm Hg in 24% (11/45) of paired measurements.  The SunTech Medical Advantage Model 2 Series with firmware LX 3.40.8 algorithm noninvasive blood pressure module is validated in pregnancy, including patients with preeclampsia; however, it may underestimate systolic blood pressure measurements in patients with preeclampsia. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Human habitation field study of the Habitat Demonstration Unit (HDU)

NASA Astrophysics Data System (ADS)

Litaker, Harry L.; Archer, Ronald D.; Szabo, Richard; Twyford, Evan S.; Conlee, Carl S.; Howard, Robert L.

2013-10-01

Landing and supporting a permanent outpost on a planetary surface represents humankind's capability to expand its own horizons and challenge current technology. With this in mind, habitability of these structures becomes more essential given the longer durations of the missions. The purpose of this evaluation was to obtain preliminary human-in-the-loop performance data on the Habitat Demonstration Unit (HDU) in a Pressurized Excursion Module (PEM) configuration during a 14-day simulated lunar exploration field trial and to apply this knowledge to further enhance the habitat's capabilities for forward designs. Human factors engineers at the NASA/Johnson Space Center's Habitability and Human Factors Branch recorded approximately 96 h of crew task performance with four work stations. Human factors measures used during this study included the NASA Task Load Index (TLX) and customized post questionnaires. Overall the volume for the PEM was considered acceptable by the crew; however; the habitat's individual work station volume was constrained when setting up the vehicle for operation, medical operations, and suit maintenance while general maintenance, logistical resupply, and geo science was considered acceptable. Crew workload for each station indicated resupply as being the lowest rated, with medical operations, general maintenance, and geo science tasks as being light, while suit maintenance was considered moderate and general vehicle setup being rated the highest. Stowage was an issue around the habitat with the Space Exploration Vehicle (SEV) resupply stowage located in the center of the habitat as interfering with some work station volumes and activities. Ergonomics of the geo science station was considered a major issue, especially with the overhead touch screens.

Multicultural Group Work on Field Excursions to Promote Student Teachers' Intercultural Competence

ERIC Educational Resources Information Center

Brendel, Nina; Aksit, Fisun; Aksit, Selahattin; Schrüfer, Gabriele

2016-01-01

As a response to the intercultural challenges of Geography Education, this study seeks to determine factors fostering intercultural competence of student teachers. Based on a one-week multicultural field excursion of eight German and eight Turkish students in Kayseri (Turkey) on Education for Sustainable Development, we used qualitative interviews…

Enabling the Development of Student Teacher Professional Identity through Vicarious Learning during an Educational Excursion

ERIC Educational Resources Information Center

Steenekamp, Karen; van der Merwe, Martyn; Mehmedova, Aygul Salieva

2018-01-01

This paper explores the views of student teachers who were provided vicarious learning opportunities during an educational excursion, and how the learning enabled them to develop their teacher professional identity. This qualitative research study, using a social-constructivist lens highlights how vicarious learning influenced student teachers'…

Japanese Experiment Module arrival

NASA Image and Video Library

2007-03-29

Inside the Space Station Processing Facility, workers monitor progress as a huge crane is used to remove the top of the crate carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

Japanese Experiment Module arrival

NASA Image and Video Library

2007-03-29

Inside the Space Station Processing Facility, the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module is revealed after the top of the crate is removed. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

Tonic blood pressure modulates the relationship between baroreceptor cardiac reflex sensitivity and cognitive performance.

PubMed

Del Paso, Gustavo A Reyes; González, M Isabel; Hernández, José Antonio; Duschek, Stefan; Gutiérrez, Nicolás

2009-09-01

This study explored the effects of tonic blood pressure on the association between baroreceptor cardiac reflex sensitivity and cognitive performance. Sixty female participants completed a mental arithmetic task. Baroreceptor reflex sensitivity was assessed using sequence analysis. An interaction was found, indicating that the relationship between baroreceptor reflex sensitivity and cognitive performance is modulated by blood pressure levels. Reflex sensitivity was inversely associated to performance indices in the subgroup of participants with systolic blood pressure above the mean, whereas the association was positive in participants with systolic values below the mean. These results are in accordance with the findings in the field of pain perception and suggest that tonic blood pressure modulates the inhibitory effects of baroreceptor stimulation on high central nervous functions.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto (right) looks at the newly arrived Japanese Experiment Module (JEM)/pressurized module. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of JEM.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto (right) looks at the newly arrived Japanese Experiment Module (JEM)/pressurized module. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of JEM.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto (left) looks at the newly arrived Japanese Experiment Module (JEM)/pressurized module. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of JEM.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto (left) looks at the newly arrived Japanese Experiment Module (JEM)/pressurized module. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of JEM.

Electrical Pressurization Concept for the Orion MPCV European Service Module Propulsion System

NASA Technical Reports Server (NTRS)

Meiss, Jan-Hendrik; Weber, Jorg; Ierardo, Nicola; Quinn, Frank D.; Paisley, Jonathan

2015-01-01

The paper presents the design of the pressurization system of the European Service Module (ESM) of the Orion Multi-Purpose Crew Vehicle (MPCV). Being part of the propulsion subsystem, an electrical pressurization concept is implemented to condition propellants according to the engine needs via a bang-bang regulation system. Separate pressurization for the oxidizer and the fuel tank permits mixture ratio adjustments and prevents vapor mixing of the two hypergolic propellants during nominal operation. In case of loss of pressurization capability of a single side, the system can be converted into a common pressurization system. The regulation concept is based on evaluation of a set of tank pressure sensors and according activation of regulation valves, based on a single-failure tolerant weighting of three pressure signals. While regulation is performed on ESM level, commanding of regulation parameters as well as failure detection, isolation and recovery is performed from within the Crew Module, developed by Lockheed Martin Space System Company. The overall design and development maturity presented is post Preliminary Design Review (PDR) and reflects the current status of the MPCV ESM pressurization system.

Fast response air-to-fuel ratio measurements using a novel device based on a wide band lambda sensor

NASA Astrophysics Data System (ADS)

Regitz, S.; Collings, N.

2008-07-01

A crucial parameter influencing the formation of pollutant gases in internal combustion engines is the air-to-fuel ratio (AFR). During transients on gasoline and diesel engines, significant AFR excursions from target values can occur, but cycle-by-cycle AFR resolution, which is helpful in understanding the origin of deviations, is difficult to achieve with existing hardware. This is because current electrochemical devices such as universal exhaust gas oxygen (UEGO) sensors have a time constant of 50-100 ms, depending on the engine running conditions. This paper describes the development of a fast reacting device based on a wide band lambda sensor which has a maximum time constant of ~20 ms and enables cyclic AFR measurements for engine speeds of up to ~4000 rpm. The design incorporates a controlled sensor environment which results in insensitivity to sample temperature and pressure. In order to guide the development process, a computational model was developed to predict the effect of pressure and temperature on the diffusion mechanism. Investigations regarding the sensor output and response were carried out, and sensitivities to temperature and pressure are examined. Finally, engine measurements are presented.

In-line pressure-flow module for in vitro modelling of haemodynamics and biosensor validation

NASA Technical Reports Server (NTRS)

Koenig, S. C.; Schaub, J. D.; Ewert, D. L.; Swope, R. D.; Convertino, V. A. (Principal Investigator)

1997-01-01

An in-line pressure-flow module for in vitro modelling of haemodynamics and biosensor validation has been developed. Studies show that good accuracy can be achieved in the measurement of pressure and of flow, in steady and pulstile flow systems. The model can be used for development, testing and evaluation of cardiovascular-mechanical-electrical anlogue models, cardiovascular prosthetics (i.e. valves, vascular grafts) and pressure and flow biosensors.

An investigation into the effects of frequency-modulated transcutaneous electrical nerve stimulation (TENS) on experimentally-induced pressure pain in healthy human participants.

PubMed

Chen, Chih-Chung; Johnson, Mark I

2009-10-01

Frequency-modulated transcutaneous electrical nerve stimulation (TENS) delivers currents that fluctuate between preset boundaries over a fixed period of time. This study compared the effects of constant-frequency TENS and frequency-modulated TENS on blunt pressure pain in healthy human volunteers. Thirty-six participants received constant-frequency TENS (80 pps), frequency-modulated TENS (20 to 100 pps), and placebo (no current) TENS at a strong nonpainful intensity in a randomized cross-over manner. Pain threshold was taken from the forearm using pressure algometry. There were no statistical differences between constant-frequency TENS and frequency-modulated TENS after 20 minutes (OR = 1.54; CI, 0.29, 8.23, P = 1.0). Both constant-frequency TENS and frequency-modulated TENS were superior to placebo TENS (OR = 59.5, P < .001 and OR = 38.5, P < .001, respectively). Frequency-modulated TENS does not influence hypoalgesia to any greater extent than constant-frequency TENS when currents generate a strong nonpainful paraesthesia at the site of pain. The finding that frequency-modulated TENS and constant-frequency TENS were superior to placebo TENS provides further evidence that a strong yet nonpainful TENS intensity is a prerequisite for hypoalgesia. This study provides evidence that TENS, delivered at a strong nonpainful intensity, increases pain threshold to pressure algometry in healthy participants over and above that seen with placebo (no current) TENS. Frequency-modulated TENS does not increase hypoalgesia to any appreciable extent to that seen with constant-frequency TENS.

Dating the Laschamp Excursion: Why Speleothems are Valuable Tools for Constraining the Timing and Duration of Short-Lived Geomagnetic Events

NASA Astrophysics Data System (ADS)

Lascu, I.; Feinberg, J. M.; Dorale, J. A.; Cheng, H.; Edwards, R. L.

2015-12-01

Short-lived geomagnetic events are reflections of geodynamo behavior at small length scales. A rigorous documentation of the anatomy, timing, duration, and frequency of centennial-to-millennial scale geomagnetic events can be invaluable for theoretical and numerical geodynamo models, and for the understanding the finer dynamics of the Earth's core. A critical ingredient for characterizing such geomagnetic instabilities are tightly constrained age models that enable high-resolution magnetostratigraphies. Here we focus on a North American speleothem geomagnetic record of the Laschamp excursion, which was the first geomagnetic excursion recognized and described in the paleomagnetic record, and remains the most studied event of its kind. The geological significance of the Laschamp lies chiefly in the fact that it constitutes a global time-synchronous geochronological marker. The Laschamp excursion occurred around the time of the demise of Homo neanderthalensis, in conjunction with high-amplitude, rapid climatic oscillations leading into the Last Glacial Maximum, and precedes a major supervolcano eruption in the Mediterranean. Thus, the precise determination of the timing and duration of the Laschamp would help in elucidating major scientific questions situated at the intersection of geology, paleoclimatology, and anthropology. Here we present a geomagnetic record from a stalagmite collected in Crevice Cave, Missouri, which we have dated using a combination of high-precision 230Th ages and annual layer counting using confocal microscopy. We have found a maximum duration for the Laschamp that spans the interval 42,250-39,700 years BP, and an age of 41,100 ± 350 years BP for the height of the excursion. During this period relative paleointensity decreased by an order of magnitude and the virtual geomagnetic pole was located at southerly latitudes. Our chronology provides the first robust bracketing for the Laschamp excursion, and improves on previous age determinations based on 40Ar/39Ar dating of lava flows, and orbitally-tuned sedimentary and ice-core records.

Glycemic excursions are positively associated with changes in duration of asymptomatic hypoglycemia after treatment intensification in patients with type 2 diabetes.

PubMed

Wang, Jun-Sing; Lee, I-Te; Lee, Wen-Jane; Lin, Shi-Dou; Su, Shih-Li; Tu, Shih-Te; Tseng, Yao-Hsien; Lin, Shih-Yi; Sheu, Wayne Huey-Herng

2016-03-01

The aim of this study was to examine the association between glycemic excursions and duration of hypoglycemia after treatment intensification in patients with type 2 diabetes (T2D). Patients with T2D on oral anti-diabetes drug (OAD) with glycated hemoglobin (HbA1c) of 7.0-11.0% were switched to metformin monotherapy (500 mg thrice daily) for 8 weeks, followed by randomization to either glibenclamide or acarbose as add-on treatment for 16 weeks. Glycemic excursions were assessed as mean amplitude of glycemic excursions (MAGE) with 72-h ambulatory continuous glucose monitoring (CGM) before randomization and at the end of study. Hypoglycemia was defined as sensor glucose level of less than 60 mg/dl in two or more consecutive readings from CGM. A total of 50 patients (mean age 53.5 ± 8.2 years, male 48%, mean baseline HbA1c 8.4 ± 1.2%) were analyzed. Duration of hypoglycemia significantly increased after treatment with glibenclamide (from 5.5 ± 13.8 to 18.8 ± 35.8 min/day, p=0.041), but not with acarbose (from 2.9 ± 10.9 to 14.7 ± 41.9 min/day, p=0.114). Post treatment MAGE was positively associated with change from baseline in duration of hypoglycemia after treatment with either glibenclamide (β coefficient 0.345, p=0.036) or acarbose (β coefficient 0.674, p=0.046). The association remained significant after multivariate adjustment (p<0.05 for all models). Post treatment glycemic excursions are associated with changes in duration of hypoglycemia after treatment intensification with OAD in patients with T2D. Glycemic excursions should be an important treatment target for T2D to reduce the risk of hypoglycemia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Knee Joint Contact Mechanics during Downhill Gait and its Relationship with Varus/Valgus Motion and Muscle Strength in Patients with Knee Osteoarthritis

PubMed Central

Farrokhi, Shawn; Voycheck, Carrie A.; Gustafson, Jonathan A.; Fitzgerald, G. Kelley; Tashman, Scott

2015-01-01

Objective The objective of this exploratory study was to evaluate tibiofemoral joint contact point excursions and velocities during downhill gait and assess the relationship between tibiofemoral joint contact mechanics with frontal-plane knee joint motion and lower extremity muscle weakness in patients with knee osteoarthritis (OA). Methods Dynamic stereo X-ray was used to quantify tibiofemoral joint contact mechanics and frontal-plane motion during the loading response phase of downhill gait in 11 patients with knee OA and 11 control volunteers. Quantitative testing of the quadriceps and the hip abductor muscles was also performed. Group differences in contact mechanics and frontal-plane motion excursions were compared using analysis of covariance with adjustments for body mass index. Differences in strength were compared using independent sample t-tests. Additionally, linear associations between contact mechanics with frontal-plane knee motion and muscle strength were evaluated using Pearson's correlation coefficients. Results Patients with knee OA demonstrated larger medial/lateral joint contact point excursions (p<0.02) and greater heel-strike joint contact point velocities (p<0.05) for the medial and lateral compartments compared to the control group. The peak medial/lateral joint contact point velocity of the medial compartment was also greater for patients with knee OA compared to their control counterparts (p=0.02). Additionally, patients with knee OA demonstrated significantly increased frontal-plane varus motion excursions (p<0.01) and greater quadriceps and hip abductor muscle weakness (p=0.03). In general, increased joint contact point excursions and velocities in patients with knee OA were linearly associated with greater frontal-plane varus motion excursions (p<0.04) but not with quadriceps or hip abductor strength. Conclusion Altered contact mechanics in patients with knee OA may be related to compromised frontal-plane joint stability but not with deficits in muscle strength. PMID:27030846

Nateglinide and acarbose are comparably effective reducers of postprandial glycemic excursions in chinese antihyperglycemic agent-naive subjects with type 2 diabetes.

PubMed

Zhou, Jian; Li, Hong; Zhang, Xiuzhen; Peng, Yongde; Mo, Yifei; Bao, Yuqian; Jia, Weiping

2013-06-01

Recent studies have identified postprandial glycemic excursions as risk factors for diabetes complications. This study aimed to compare the effects of nateglinide and acarbose treatments on postprandial glycemic excursions in Chinese subjects with type 2 diabetes. This was a multicenter, open-label, randomized, active-controlled, parallel-group study. One hundred three antihyperglycemic agent-naive subjects with type 2 diabetes (hemoglobin A1c range, 6.5-9.0%) were prospectively recruited from four hospitals in China. The intervention was nateglinide (120 mg three times a day) or acarbose (50 mg three times a day) therapy for 2 weeks. A continuous glucose monitoring system was used to calculate the incremental area under the curve of postprandial blood glucose (AUCpp), the incremental glucose peak (IGP), mean amplitude of glycemic excursions, SD of blood glucose, the mean of daily differences, and 24-h mean blood glucose (MBG). Subjects' serum glycated albumin and the plasma insulin levels were also analyzed. Both agents caused significant reductions on AUCpp and IGP. Similarly, both treatment groups showed significant improvements in the intra- and interday glycemic excursions, as well as the 24-h MBG and serum glycated albumin compared with baseline (P<0.001). However, neither of the agents produced a significantly better effect (P>0.05). Moreover, the nateglinide-treated group had significantly increased insulin levels at 30 min and at 120 min after a standard meal compared with baseline, whereas the acarbose-treated group decreased. No serious adverse events occurred in either group. The rates of hypoglycemic episodes were comparable in the two groups, and no severe hypoglycemic episode occurred in either group. Nateglinide and acarbose were comparably effective in reducing postprandial glycemic excursions in antihyperglycemic agent-naive Chinese patients with type 2 diabetes, possibly through different pathophysiological mechanisms.

Is the Earth's magnetic field heading for a flip? Hints from the past

NASA Astrophysics Data System (ADS)

Laj, C. E.; Kissel, C.

2017-12-01

The magnitude of the Earth's dipole magnetic field has decreased significantly over the last centuries at a mean rate of 16 nT/y. This decrease, which correlates with the growth of the South Atlantic Anomaly (SAA) therefore occurs at a rate which is about 10 times larger than expected from a free Ohmic decay process. This situation has led to speculations that an attempt to a reversal or a geomagnetic excursion might be underway. We investigate this hypothesis by examining past geomagnetic instabilities, focussing on the well documented Laschamp and Mono Lake excursions. We have selected high accumulation sedimentary records with very precise age model, leading to unprecedented temporal resolution, and accurate calibration of RPI between 20 and 75 kyr B.P. We also used the 10Be and 36Cl records from the Greenland ice cores. The rate of decay of the field intensity during these two excursions is virtually identical to that observed over the last centuries and much higher than that observed for another period of low intensity (around 65 kyr BP) not associated with a polarity change. Moreover, the global morphology of the Laschamp excursion obtained by Bayesian inversion (Leonhardt et al. (2009) is that reverse magnetic field patches at the core-mantle boundary are formed near the equator and then move poleward, a scenario reminiscent of that described for the present field in the litterature. Therefore, although these results from two excursions do not provide undisputable information on future evolution of the field, they show similarities with several aspects of the present-day geomagnetic field. Assuming that the dynamo processes for an eventual future instability would be similar to those of the past two excursions, we tentatively suggest that, whilst irreversible processes that will drive the geodynamo into a polarity change may have already started, some 1000 years would be needed for the directional changes to start to be significant.

Glucose and triglyceride excursions following a standardized meal in individuals with diabetes: ELSA-Brasil study.

PubMed

Riboldi, Bárbara P; Luft, Vivian C; de Castilhos, Cristina D; de Cardoso, Letícia O; Schmidt, Maria I; Barreto, Sandhi M; de Sander, Maria F; Alvim, Sheila M; Duncan, Bruce B

2015-02-13

To assess glucose and triglyceride excursions 2 hours after the ingestion of a standardized meal and their associations with clinical characteristics and cardiovascular complications in individuals with diabetes. Blood samples of 898 subjects with diabetes were collected at fasting and 2 hours after a meal containing 455 kcal, 14 g of saturated fat and 47 g of carbohydrates. Self-reported morbidity, socio-demographic characteristics and clinical measures were obtained by interview and exams performed at the baseline visit of the ELSA-Brasil cohort study. Median (interquartile range, IQR) for fasting glucose was 150.5 (123-198) mg/dL and for fasting triglycerides 140 (103-199) mg/dL. The median excursion for glucose was 45 (15-76) mg/dL and for triglycerides 26 (11-45) mg/dL. In multiple linear regression, a greater glucose excursion was associated with higher glycated hemoglobin (10.7, 95% CI 9.1-12.3 mg/dL), duration of diabetes (4.5; 2.6-6.4 mg/dL, per 5 year increase), insulin use (44.4; 31.7-57.1 mg/dL), and age (6.1; 2.5-9.6 mg/dL, per 10 year increase); and with lower body mass index (-5.6; -8.4- -2.8 mg/dL, per 5 kg/m2 increase). In adjusted logistic regression models, a greater glucose excursion was marginally associated with the presence of cardiovascular comorbidities (coronary heart disease, myocardial infarction and angina) in those with obesity. A greater postprandial glycemic response to a small meal was positively associated with indicators of a decreased capacity for insulin secretion and negatively associated with obesity. No pattern of response was observed with a greater postprandial triglyceride excursion.

Nateglinide and Acarbose Are Comparably Effective Reducers of Postprandial Glycemic Excursions in Chinese Antihyperglycemic Agent–Naive Subjects with Type 2 Diabetes

PubMed Central

Zhou, Jian; Li, Hong; Zhang, Xiuzhen; Peng, Yongde; Mo, Yifei; Bao, Yuqian

2013-01-01

Abstract Background Recent studies have identified postprandial glycemic excursions as risk factors for diabetes complications. This study aimed to compare the effects of nateglinide and acarbose treatments on postprandial glycemic excursions in Chinese subjects with type 2 diabetes. Subjects and Methods This was a multicenter, open-label, randomized, active-controlled, parallel-group study. One hundred three antihyperglycemic agent–naive subjects with type 2 diabetes (hemoglobin A1c range, 6.5–9.0%) were prospectively recruited from four hospitals in China. The intervention was nateglinide (120 mg three times a day) or acarbose (50 mg three times a day) therapy for 2 weeks. A continuous glucose monitoring system was used to calculate the incremental area under the curve of postprandial blood glucose (AUCpp), the incremental glucose peak (IGP), mean amplitude of glycemic excursions, SD of blood glucose, the mean of daily differences, and 24-h mean blood glucose (MBG). Subjects' serum glycated albumin and the plasma insulin levels were also analyzed. Results Both agents caused significant reductions on AUCpp and IGP. Similarly, both treatment groups showed significant improvements in the intra- and interday glycemic excursions, as well as the 24-h MBG and serum glycated albumin compared with baseline (P<0.001). However, neither of the agents produced a significantly better effect (P>0.05). Moreover, the nateglinide-treated group had significantly increased insulin levels at 30 min and at 120 min after a standard meal compared with baseline, whereas the acarbose-treated group decreased. No serious adverse events occurred in either group. The rates of hypoglycemic episodes were comparable in the two groups, and no severe hypoglycemic episode occurred in either group. Conclusions Nateglinide and acarbose were comparably effective in reducing postprandial glycemic excursions in antihyperglycemic agent–naive Chinese patients with type 2 diabetes, possibly through different pathophysiological mechanisms. PMID:23631607

Method and apparatus for coupling seismic sensors to a borehole wall

DOEpatents

West, Phillip B.

2005-03-15

A method and apparatus suitable for coupling seismic or other downhole sensors to a borehole wall in high temperature and pressure environments. In one embodiment, one or more metal bellows mounted to a sensor module are inflated to clamp the sensor module within the borehole and couple an associated seismic sensor to a borehole wall. Once the sensing operation is complete, the bellows are deflated and the sensor module is unclamped by deflation of the metal bellows. In a further embodiment, a magnetic drive pump in a pump module is used to supply fluid pressure for inflating the metal bellows using borehole fluid or fluid from a reservoir. The pump includes a magnetic drive motor configured with a rotor assembly to be exposed to borehole fluid pressure including a rotatable armature for driving an impeller and an associated coil under control of electronics isolated from borehole pressure.

Alarms based on real-time sensor glucose values alert patients to hypo- and hyperglycemia: the guardian continuous monitoring system.

PubMed

Bode, Bruce; Gross, Kenneth; Rikalo, Nancy; Schwartz, Sherwyn; Wahl, Timothy; Page, Casey; Gross, Todd; Mastrototaro, John

2004-04-01

The purposes of this study were to demonstrate the accuracy and effectiveness of the Guardian Continuous Monitoring System (Medtronic MiniMed, Northridge, California) and to demonstrate that the application of real-time alarms to continuous monitoring alerts users to hypo and hyperglycemia and reduces excursions in people with diabetes. A total of 71 subjects with type 1 diabetes, mean hemoglobin A1c of 7.6 +/- 1.1%, age 44.0 +/- 11.4 years, and duration of diabetes 23.6 +/- 10.6 years were enrolled in this two-period, randomized, multicenter study. Subjects were randomized into either an Alert group or a Control group. The accuracy of the Guardian was evaluated by treating the study data as a single-sample correlational design. Effectiveness of the Guardian alerts was evaluated by comparing the Alert group with the Control group. The mean (median) absolute relative error between home blood glucose meter readings and sensor values was 21.3% (17.3%), and the Guardian, on average, read 12.8 mg/dL below the concurrent home blood glucose meter readings. The hypoglycemia alert was able to distinguished glucose values < or =70 mg/dL with 67% sensitivity, 90% specificity, and 47% false alerts. The hyperglycemia alert showed a similar ability to detect sensor values > or =250 mg/dL with 63% sensitivity, 97% specificity, and 19% false alerts. The Alert group demonstrated a median decrease in the duration of hypoglycemic excursions (-27.8 min) that was significantly greater than the median decrease in the duration of hypoglycemic excursions in the Control group (-4.5 min) (P = 0.03). A marginally significant increase in the frequency of hyperglycemic excursions (P = 0.07) between Period 1 and Period 2 was accompanied by a decrease of 9.6 min in the duration of hyperglycemic excursions in the Alert group. Glucose measurements differ between blood samples taken from the finger and interstitial fluid, especially when levels are changing rapidly; however, these results demonstrate that the Guardian is reasonably accurate while performing continuous glucose monitoring. The subjects' responses to hypoglycemia alerts resulted in a significant reduction in the duration of hypoglycemic excursions; however, overtreating hypoglycemia may have resulted in a marginally significant increase in the frequency of hyperglycemic excursions.

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (right) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (center, foreground) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (right) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (center, foreground) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (right) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (third from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (right) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (third from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (left) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (second from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (left) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (second from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (right) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (second from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (right) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (second from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

KENNEDY SPACE CENTER, FLA. - Executive Director of NASDA Koji Yamamoto (left) is welcomed to KSC by Center Director Roy Bridges Jr. (right). Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module. His visit includes a tour of the Columbia Debris Hangar.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - Executive Director of NASDA Koji Yamamoto (left) is welcomed to KSC by Center Director Roy Bridges Jr. (right). Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module. His visit includes a tour of the Columbia Debris Hangar.

Lateral Ligament Repair and Reconstruction Restore Neither Contact Mechanics of the Ankle Joint nor Motion Patterns of the Hindfoot

PubMed Central

Prisk, Victor R.; Imhauser, Carl W.; O'Loughlin, Padhraig F.; Kennedy, John G.

2010-01-01

Background: Ankle sprains may damage both the lateral ligaments of the hindfoot and the osteochondral tissue of the ankle joint. When nonoperative treatment fails, operative approaches are indicated to restore both native motion patterns at the hindfoot and ankle joint contact mechanics. The goal of the present study was to determine the effect of lateral ligament injury, repair, and reconstruction on ankle joint contact mechanics and hindfoot motion patterns. Methods: Eight cadaveric specimens were tested with use of robotic technology to apply combined compressive (200-N) and inversion (4.5-Nm) loads to the hindfoot at 0° and 20° of plantar flexion. Contact mechanics at the ankle joint were simultaneously measured. A repeated-measures experiment was designed with use of the intact condition as control, with the other conditions including sectioned anterior talofibular and calcaneofibular ligaments, the Broström and Broström-Gould repairs, and graft reconstruction. Results: Ligament sectioning decreased contact area and caused a medial and anterior shift in the center of pressure with inversion loads relative to those with the intact condition. There were no significant differences in inversion or coupled axial rotation with inversion between the Broström repair and the intact condition; however, medial translation of the center of pressure remained elevated after the Broström repair relative to the intact condition. The Gould modification of the Broström procedure provided additional support to the hindfoot relative to the Broström repair, reducing inversion and axial rotation with inversion beyond that of intact ligaments. There were no significant differences in center-of-pressure excursion patterns between the Broström-Gould repair and the intact ligament condition, but this repair increased contact area beyond that with the ligaments intact. Graft reconstruction more closely restored inversion motion than did the Broström-Gould repair at 20° of plantar flexion but limited coupled axial rotation. Graft reconstruction also increased contact areas beyond the lateral ligament-deficient conditions but altered center-of-pressure excursion patterns relative to the intact condition. Conclusions: No lateral ankle ligament reconstruction completely restored native contact mechanics of the ankle joint and hindfoot motion patterns. Clinical Relevance: Our results provide a rationale for conducting long-term, prospective, comparative, in vivo studies to assess the impact of altered mechanics following lateral ligament injury, and its nonoperative and operative treatment, on the development of ankle osteoarthritis. PMID:20962188

A Study of the Time Dependence in Fracture Processes Relating to Service Life Prediction of Adhesive Joints and Advanced Composites.

DTIC Science & Technology

1981-04-30

fluid temperature should exceed 145°F. The flow control module contains all the hydraulic circuit elements necessary for both the pressure line to and...are contained in three basic modules : 1) the hydraulic power supply, 2) a flow control module containing valving, accumulators and filters, and 3) the...hydraulic transient overpressures, is located in the flow control module , as are the high and low pressure filters. The load frame (MTS Systems Corp

System design of the Pioneer Venus spacecraft. Volume 5: Probe vehicle studies

NASA Technical Reports Server (NTRS)

Nolte, L. J.; Stephenson, D. S.

1973-01-01

A summary of the key issues and studies conducted for the Pioneer Venus spacecraft and the resulting probe designs are presented. The key deceleration module issues are aerodynamic configuration and heat shield material selection. The design and development of the pressure vessel module are explained. Thermal control and science integration of the pressure vessel module are explained. The deceleration module heat shield, parachute and separation/despin are reported. The Thor/Delta and Atlas/Centaur baseline descriptions are provided.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto points to other Space Station elements. Behind him is the Japanese Experiment Module (JEM)/pressurized module. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of JEM.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto points to other Space Station elements. Behind him is the Japanese Experiment Module (JEM)/pressurized module. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of JEM.

KENNEDY SPACE CENTER, FLA. - STS-120 Mission Specialists Piers Sellers and Michael Foreman look at the Japanese Experiment Module (JEM) Pressurized Module located in the Space Station Processing Facility. Known as Kibo, the JEM consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The STS-120 mission will deliver the second of three Station connecting modules, Node 2, which attaches to the end of U.S. Lab. It will provide attach locations for the JEM, European laboratory, the Centrifuge Accommodation Module and later Multi-Purpose Logistics Modules. The addition of Node 2 will complete the U.S. core of the International Space Station.

NASA Image and Video Library

2003-07-18

KENNEDY SPACE CENTER, FLA. - STS-120 Mission Specialists Piers Sellers and Michael Foreman look at the Japanese Experiment Module (JEM) Pressurized Module located in the Space Station Processing Facility. Known as Kibo, the JEM consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The STS-120 mission will deliver the second of three Station connecting modules, Node 2, which attaches to the end of U.S. Lab. It will provide attach locations for the JEM, European laboratory, the Centrifuge Accommodation Module and later Multi-Purpose Logistics Modules. The addition of Node 2 will complete the U.S. core of the International Space Station.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, STS-120 Mission Specialist Piers Sellers looks over the Japanese Experiment Module (JEM) Pressurized Module. Known as Kibo, the JEM consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The STS-120 mission will deliver the second of three Station connecting modules, Node 2, which attaches to the end of U.S. Lab. It will provide attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and later Multi-Purpose Logistics Modules. The addition of Node 2 will complete the U.S. core of the International Space Station.

NASA Image and Video Library

2003-07-18

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, STS-120 Mission Specialist Piers Sellers looks over the Japanese Experiment Module (JEM) Pressurized Module. Known as Kibo, the JEM consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The STS-120 mission will deliver the second of three Station connecting modules, Node 2, which attaches to the end of U.S. Lab. It will provide attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and later Multi-Purpose Logistics Modules. The addition of Node 2 will complete the U.S. core of the International Space Station.

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, STS-120 Mission Specialist Michael Foreman looks over the Japanese Experiment Module (JEM) Pressurized Module. Known as Kibo, the JEM consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The STS-120 mission will deliver the second of three Station connecting modules, Node 2, which attaches to the end of U.S. Lab. It will provide attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and later Multi-Purpose Logistics Modules. The addition of Node 2 will complete the U.S. core of the International Space Station.

NASA Image and Video Library

2003-07-18

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, STS-120 Mission Specialist Michael Foreman looks over the Japanese Experiment Module (JEM) Pressurized Module. Known as Kibo, the JEM consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The STS-120 mission will deliver the second of three Station connecting modules, Node 2, which attaches to the end of U.S. Lab. It will provide attach locations for the Japanese laboratory, European laboratory, the Centrifuge Accommodation Module and later Multi-Purpose Logistics Modules. The addition of Node 2 will complete the U.S. core of the International Space Station.

Students' Long-Term Memories from an Ecology Field Excursion: Retelling a Narrative as an Interplay between Implicit and Explicit Memories

ERIC Educational Resources Information Center

Stolpe, Karin; Bjorklund, Lars

2013-01-01

This study aims to investigate the science content remembered by biology students 6 and 12 months after an ecology excursion. The students' memories were tested during a stimulated recall interview. The authors identified three different types of memories: "recall," "recognition" and "narratives." The "dual…

A Review of Criticality Accidents 2000 Revision

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

Thomas P. McLaughlin; Shean P. Monahan; Norman L. Pruvost

Criticality accidents and the characteristics of prompt power excursions are discussed. Sixty accidental power excursions are reviewed. Sufficient detail is provided to enable the reader to understand the physical situation, the chemistry and material flow, and when available the administrative setting leading up to the time of the accident. Information on the power history, energy release, consequences, and causes are also included when available. For those accidents that occurred in process plants, two new sections have been included in this revision. The first is an analysis and summary of the physical and neutronic features of the chain reacting systems. Themore » second is a compilation of observations and lessons learned. Excursions associated with large power reactors are not included in this report.« less

Plug nozzles: The ultimate customer driven propulsion system

NASA Technical Reports Server (NTRS)

Aukerman, Carl A.

1991-01-01

This paper presents the results of a study applying the plug cluster nozzle concept to the propulsion system for a typical lunar excursion vehicle. Primary attention for the design criteria is given to user defined factors such as reliability, low volume, and ease of propulsion system development. Total thrust and specific impulse are held constant in the study while other parameters are explored to minimize the design chamber pressure. A brief history of the plug nozzle concept is included to point out the advanced level of technology of the concept and the feasibility of exploiting the variables considered in this study. The plug cluster concept looks very promising as a candidate for consideration for the ultimate customer driven propulsion system.

Plug nozzles - The ultimate customer driven propulsion system. [applied to manned lunar and Martian landers

NASA Technical Reports Server (NTRS)

Aukerman, Carl A.

1991-01-01

This paper presents the results of a study applying the plug cluster nozzle concept to the propulsion system for a typical lunar excursion vehicle. Primary attention for the design criteria is given to user defined factors such as reliability, low volume, and ease of propulsion system development. Total thrust and specific impulse are held constant in the study while other parameters are explored to minimize the design chamber pressure. A brief history of the plug nozzle concept is included to point out the advanced level of technology of the concept and the feasibility of exploiting the variables considered in the study. The plug cluster concept looks very promising as a candidate for consideration for the ultimate customer driven propulsion system.

Results from flight and simulator studies of a Mach 3 cruise longitudinal autopilot

NASA Technical Reports Server (NTRS)

Gilyard, G. B.; Smith, J. W.

1978-01-01

At Mach numbers of approximately 3.0 and altitudes greater than 21,300 meters, the original altitude and Mach hold modes of the YF-12 autopilot produced aircraft excursions that were erratic or divergent, or both. Flight data analysis and simulator studies showed that the sensitivity of the static pressure port to angle of attack had a detrimental effect on the performance of the altitude and Mach hold modes. Good altitude hold performance was obtained when a high passed pitch rate feedback was added to compensate for angle of attack sensitivity and the altitude error and integral altitude gains were reduced. Good Mach hold performance was obtained when the angle of attack sensitivity was removed; however, the ride qualities remained poor.

LOD-climate Links: how the 2015-2016 El Niño Lengthened the Day by 0.8 ms, and Possible Rotational Forcing of Multidecadal Temperature Changes

NASA Astrophysics Data System (ADS)

Lambert, S. B.; de Viron, O.; Marcus, S.

2016-12-01

El Niño events are generally accompanied by significant changes in the Earth's length-of-day (LOD) that can be explained by two approaches. Considering the angular momentum conservation of the system composed by the solid Earth and the atmosphere, ENSO events are accompanied by a strengthening of the subtropical jet streams, and, therefore, a decrease of the Earth's rotation rate. Using the torque approach, the low pressure field of the Eastern Pacific, which is close to high mountain ranges along the Western American coasts, creates a negative torque of the atmosphere on the solid Earth which tends to slow down the Earth's rotation. The large 1983 event was associated with a lengthening of the day of about 1 ms. During the 2015-2016 winter season, a major ENSO event occurred, classified as very strong by meteorological agencies. This central Pacific event, for which the Nino 3.4 index is as high as in 1983, was also concurrent with positive phases of PDO, NAO, and AAO. It coincided with an excursion of the LOD as large as 0.8 ms over a few weeks reaching its maximum around 2016 New Year. We evaluate the mountain and friction torques responsible for the Earth's rotation variations during the winter season and compare to the mean situations and to previous strong ENSO events of 1983 and 1998. Especially, we noticed that the contribution from American mountain ranges is close to the value of 1983. The weaker LOD excursion comes from an inexistent torque over the Himalayas, a weaker contribution from Europe, and a noticeable positive contribution from Antarctica. On longer time scales, core-generated ms-scale LOD excursions are found to precede NH surface and global SST fluctuations by nearly a decade; although the cause of this apparent rotational effect is not known, reported correlations of LOD and tidal-orbital forcing with surface and submarine volcanic activity offer prospects to explain these observations in a core-to-climate chain of causality.

Response to Tendon Vibration Questions the Underlying Rationale of Proprioceptive Training

PubMed Central

Lubetzky, Anat Vilnai; McCoy, Sarah Westcott; Price, Robert; Kartin, Deborah

2017-01-01

Context: Proprioceptive training on compliant surfaces is used to rehabilitate and prevent ankle sprains. The ability to improve proprioceptive function via such training has been questioned. Achilles tendon vibration is used in motor-control research as a form of proprioceptive stimulus. Using measures of postural steadiness with nonlinear measures to elucidate control mechanisms, tendon vibration can be applied to investigate the underlying rationale of proprioceptive training. Objective: To test whether the effect of vibration on young adults' postural control depended on the support surface. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Thirty healthy adults and 10 adults with chronic ankle instability (CAI; age range = 18−40 years). Intervention(s): With eyes open, participants stood in bilateral stance on a rigid plate (floor), memory foam, and a Both Sides Up (BOSU) ball covering a force platform. We applied bilateral Achilles tendon vibration for the middle 20 seconds in a series of 60-second trials and analyzed participants' responses from previbration to vibration (pre-vib) and from vibration to postvibration (vib-post). Main Outcome Measure(s): We calculated anterior-posterior excursion of the center of pressure and complexity index derived from the area under multiscale entropy curves. Results: The excursion response to vibration differed by surface, as indicated by a significant interaction of P < .001 for the healthy group at both time points and for the CAI group vib-post. Although both groups demonstrated increased excursion from pre-vib and from vib-post, a decrease was observed on the BOSU. The complexity response to vibration differed by surface for the healthy group (pre-vib, P < .001). The pattern for the CAI group was similar but not significant. Complexity changes vib-post were the same on all surfaces for both groups. Conclusions: Participants reacted less to ankle vibration when standing on the BOSU as compared with the floor, suggesting that proprioceptive training may not be occurring. Different balance-training paradigms to target proprioception, including tendon vibration, should be explored. PMID:28125270

Modular robot

DOEpatents

Ferrante, T.A.

1997-11-11

A modular robot may comprise a main body having a structure defined by a plurality of stackable modules. The stackable modules may comprise a manifold, a valve module, and a control module. The manifold may comprise a top surface and a bottom surface having a plurality of fluid passages contained therein, at least one of the plurality of fluid passages terminating in a valve port located on the bottom surface of the manifold. The valve module is removably connected to the manifold and selectively fluidically connects the plurality of fluid passages contained in the manifold to a supply of pressurized fluid and to a vent. The control module is removably connected to the valve module and actuates the valve module to selectively control a flow of pressurized fluid through different ones of the plurality of fluid passages in the manifold. The manifold, valve module, and control module are mounted together in a sandwich-like manner and comprise a main body. A plurality of leg assemblies are removably connected to the main body and are removably fluidically connected to the fluid passages in the manifold so that each of the leg assemblies can be selectively actuated by the flow of pressurized fluid in different ones of the plurality of fluid passages in the manifold. 12 figs.

KSC-07pd0900

NASA Image and Video Library

2007-04-17

KENNEDY SPACE CENTER, FLA. -- After a welcoming ceremony for the Experiment Logistics Module Pressurized Section of the Japanese Experiment Module, astronaut Takao Doi (right) talks with Kumiko Tanabe, a public affairs representative of the Japanese Aerospace and Exploration Agency. The logistics module will be delivered to the space station on mission STS-123. Doi is a crew member on that mission.The module will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module. Photo credit: NASA/George Shelton

KSC-07pd0897

NASA Image and Video Library

2007-04-17

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, journalists and photographers ask Japanese astronaut Takao Doi about the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module, or JEM, that he will accompany on mission STS-123 to the International Space Station. Earlier, NASA and Japanese Aerospace and Exploration Agency (JAXA) officials welcomed the arrival of the logistics module. The logistics module will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module. Photo credit: NASA/George Shelton

Development of Japanese experiment module remote manipulator system

NASA Technical Reports Server (NTRS)

Matsueda, Tatsuo; Kuwao, Fumihiro; Motohasi, Shoichi; Okamura, Ryo

1994-01-01

National Space Development Agency of Japan (NASDA) is developing the Japanese Experiment Module (JEM), as its contribution to the International Space Station. The JEM consists of the pressurized module (PM), the exposed facility (EF), the experiment logistics module pressurized section (ELM-PS), the experiment logistics module exposed section (ELM-ES) and the Remote Manipulator System (RMS). The JEMRMS services for the JEM EF, which is a space experiment platform, consists of the Main Arm (MA), the Small Fine Arm (SFA) and the RMS console. The MA handles the JEM EF payloads, the SFA and the JEM element, such as ELM-ES.

KSC-07pd0636

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- A flat bed truck hauls the container with the Experiment Logistics Module Pressurized Section inside away from the Trident wharf. The logistics module is part of the Japanese Experiment Module, known as Kibo. The logistics module is being transported to the Space Station Processing Facility at NASA's Kennedy Space Center. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

Static Feed Water Electrolysis Subsystem Testing and Component Development

NASA Technical Reports Server (NTRS)

Koszenski, E. P.; Schubert, F. H.; Burke, K. A.

1983-01-01

A program was carried out to develop and test advanced electrochemical cells/modules and critical electromechanical components for a static feed (alkaline electrolyte) water electrolysis oxygen generation subsystem. The accomplishments were refurbishment of a previously developed subsystem and successful demonstration for a total of 2980 hours of normal operation; achievement of sustained one-person level oxygen generation performance with state-of-the-art cell voltages averaging 1.61 V at 191 ASF for an operating temperature of 128F (equivalent to 1.51V when normalized to 180F); endurance testing and demonstration of reliable performance of the three-fluid pressure controller for 8650 hours; design and development of a fluid control assembly for this subsystem and demonstration of its performance; development and demonstration at the single cell and module levels of a unitized core composite cell that provides expanded differential pressure tolerance capability; fabrication and evaluation of a feed water electrolyte elimination five-cell module; and successful demonstration of an electrolysis module pressurization technique that can be used in place of nitrogen gas during the standby mode of operation to maintain system pressure and differential pressures.

Purification of complex samples: Implementation of a modular and reconfigurable droplet-based microfluidic platform with cascaded deterministic lateral displacement separation modules

PubMed Central

Pudda, Catherine; Boizot, François; Verplanck, Nicolas; Revol-Cavalier, Frédéric; Berthier, Jean; Thuaire, Aurélie

2018-01-01

Particle separation in microfluidic devices is a common problematic for sample preparation in biology. Deterministic lateral displacement (DLD) is efficiently implemented as a size-based fractionation technique to separate two populations of particles around a specific size. However, real biological samples contain components of many different sizes and a single DLD separation step is not sufficient to purify these complex samples. When connecting several DLD modules in series, pressure balancing at the DLD outlets of each step becomes critical to ensure an optimal separation efficiency. A generic microfluidic platform is presented in this paper to optimize pressure balancing, when DLD separation is connected either to another DLD module or to a different microfluidic function. This is made possible by generating droplets at T-junctions connected to the DLD outlets. Droplets act as pressure controllers, which perform at the same time the encapsulation of DLD sorted particles and the balance of output pressures. The optimized pressures to apply on DLD modules and on T-junctions are determined by a general model that ensures the equilibrium of the entire platform. The proposed separation platform is completely modular and reconfigurable since the same predictive model applies to any cascaded DLD modules of the droplet-based cartridge. PMID:29768490

KENNEDY SPACE CENTER, FLA. - The container with the Japanese Experiment Module (JEM)’s pressurized module is inside the Space Station Processing Facility. The National Space Development Agency of Japan (NASDA) developed the laboratory at the Tsukuba Space Center near Tokyo. The Pressurized Module is the first element of the JEM, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

NASA Image and Video Library

2003-06-06

KENNEDY SPACE CENTER, FLA. - The container with the Japanese Experiment Module (JEM)’s pressurized module is inside the Space Station Processing Facility. The National Space Development Agency of Japan (NASDA) developed the laboratory at the Tsukuba Space Center near Tokyo. The Pressurized Module is the first element of the JEM, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

KENNEDY SPACE CENTER, FLA. - The truck transporting the Pressurized Module of the Japanese Experiment Module (JEM) to KSC’s Space Station Processing Facility arrives on Center. The National Space Development Agency of Japan (NASDA) developed the laboratory at the Tsukuba Space Center near Tokyo. The Pressurized Module is the first element of the JEM, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

NASA Image and Video Library

2003-06-04

KENNEDY SPACE CENTER, FLA. - The truck transporting the Pressurized Module of the Japanese Experiment Module (JEM) to KSC’s Space Station Processing Facility arrives on Center. The National Space Development Agency of Japan (NASDA) developed the laboratory at the Tsukuba Space Center near Tokyo. The Pressurized Module is the first element of the JEM, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

Mobile Lunar Base Concepts

NASA Astrophysics Data System (ADS)

Cohen, Marc M.

2004-02-01

This paper describes three innovative concepts for a mobile lunar base. These concept combine design research for habitat architecture, mobility systems, habitability, radiation protection, human factors, and living and working environments on the lunar surface. The mobile lunar base presents several key advantages over conventional static base notions. These advantages concern landing zone safety, the requirement to move modules over the lunar surface, and the ability to stage mobile reconnaissance with effective systemic redundancy. All of these concerns lead to the consideration of a mobile walking habitat module and base design. The key issues involve landing zone safety, the ability to transport habitat modules across the surface, and providing reliability and redundancy to exploration traverses in pressurized vehicles. With self-ambulating lunar base modules, it will be feasible to have each module separate itself from its retro-rocket thruster unit, and walk five to ten km away from the LZ to a pre-selected site. These mobile modules can operate in an autonomous or teleoperated mode to navigate the lunar surface. At the site of the base, the mobile modules can combine together; make pressure port connections among themselves, to create a multi-module pressurized lunar base.

KSC-07pd0635

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- A flat bed truck hauls the container with the Experiment Logistics Module Pressurized Section inside away from the Trident wharf. The logistics module is part of the Japanese Experiment Module. The logistics module is being transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0632

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, workers help guide the container with the Experiment Logistics Module Pressurized Section inside toward the dock. The logistics module is part of the Japanese Experiment Module. The logistics module will be transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

Japanese Experiment Module (JEM)

NASA Technical Reports Server (NTRS)

2003-01-01

The Japanese Experiment Module (JEM) pressure module is removed from its shipping crate and moved across the floor of the Space Station Processing Facility at Kennedy Space Center (KSC) to a work stand. A research laboratory, the pressurized module is the first element of the JEM, named 'Kibo' (Hope) to arrive at KSC. Japan's primary contribution to the International Space Station, the module will enhance unique research capabilities of the orbiting complex by providing an additional environment in which astronauts will conduct experiments. The JEM also includes an exposed facility or platform for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (second from left) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (fourth from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - Shuttle Launch Director Mike Leinbach (second from left) explains recovery and reconstruction efforts of Columbia to the Executive Director of NASDA Koji Yamamoto (fourth from left) and others visiting the Columbia Debris Hangar. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

Japanese Experiment Module arrival

NASA Image and Video Library

2007-03-29

Several components for delivery to the International Space Station sit in test stands inside the Space Station Processing Facility highbay. To the right, from back to front, are the Japanese Experiment Module, the Raffaello multi-purpose logistics module, and the European Space Agency's Columbus scientific research module. To the left in front is the starboard truss segment S5. Behind it is the test stand that will hold the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module. The logistics module is one of the components of the Japanese Experiment Module or JEM, also known as Kibo, which means "hope" in Japanese. Kibo comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007.

Effects of fatiguing treadmill running on sensorimotor control in athletes with and without functional ankle instability.

PubMed

Steib, Simon; Hentschke, Christian; Welsch, Goetz; Pfeifer, Klaus; Zech, Astrid

2013-08-01

Sensorimotor control is permanently impaired following functional ankle instability and temporarily decreased following fatigue. Little is known on potential interactions between both conditions. The purpose was to investigate the effect of fatiguing exercise on sensorimotor control in athletes with and without (coper, controls) functional ankle instability. 19 individuals with functional ankle instability, 19 ankle sprain copers, and 19 non-injured controls participated in this cohort study. Maximum reach distance in the star excursion balance test, unilateral jump landing stabilization time, center of pressure sway velocity in single-leg-stance, and passive ankle joint position sense were assessed before and immediately after fatiguing treadmill running. A three factorial linear mixed model was specified for each outcome to evaluate the effects of group, exhausting exercise (fatigue) and their interactions (group by fatigue). Effect sizes were calculated as Cohen's d. Maximum reach distance in the star excursion balance test, jump stabilization time and sway velocity, but not joint position sense, were negatively affected by fatigue in all groups. Effect sizes were moderate, ranging from 0.27 to 0.68. No significant group by fatigue interactions were found except for one measure. Copers showed significantly larger prefatigue to postfatigue reductions in anterior reach direction (P≤0.001; d=-0.55) compared to the ankle instability (P=0.007) and control group (P=0.052). Fatiguing exercise negatively affected postural control but not proprioception. Ankle status did not appear to have an effect on fatigue-induced sensorimotor control impairments. © 2013.

Predictors of chronic ankle instability: Analysis of peroneal reaction time, dynamic balance and isokinetic strength.

PubMed

Sierra-Guzmán, Rafael; Jiménez, Fernando; Abián-Vicén, Javier

2018-05-01

Previous studies have reported the factors contributing to chronic ankle instability, which could lead to more effective treatments. However, factors such as the reflex response and ankle muscle strength have not been taken into account in previous investigations. Fifty recreational athletes with chronic ankle instability and 55 healthy controls were recruited. Peroneal reaction time in response to sudden inversion, isokinetic evertor muscle strength and dynamic balance with the Star Excursion Balance Test and the Biodex Stability System were measured. The relationship between the Cumberland Ankle Instability Tool score and performance on each test was assessed and a backward multiple linear regression analysis was conducted. Participants with chronic ankle instability showed prolonged peroneal reaction time, poor performance in the Biodex Stability System and decreased reach distance in the Star Excursion Balance Test. No significant differences were found in eversion and inversion peak torque. Moderate correlations were found between the Cumberland Ankle Instability Tool score and the peroneal reaction time and performance on the Star Excursion Balance Test. Peroneus brevis reaction time and the posteromedial and lateral directions of the Star Excursion Balance Test accounted for 36% of the variance in the Cumberland Ankle Instability Tool. Dynamic balance deficits and delayed peroneal reaction time are present in participants with chronic ankle instability. Peroneus brevis reaction time and the posteromedial and lateral directions of the Star Excursion Balance Test were the main contributing factors to the Cumberland Ankle Instability Tool score. No clear strength impairments were reported in unstable ankles. Copyright © 2018 Elsevier Ltd. All rights reserved.

Knee joint contact mechanics during downhill gait and its relationship with varus/valgus motion and muscle strength in patients with knee osteoarthritis.

PubMed

Farrokhi, Shawn; Voycheck, Carrie A; Gustafson, Jonathan A; Fitzgerald, G Kelley; Tashman, Scott

2016-01-01

The objective of this exploratory study was to evaluate tibiofemoral joint contact point excursions and velocities during downhill gait and assess the relationship between tibiofemoral joint contact mechanics with frontal-plane knee joint motion and lower extremity muscle weakness in patients with knee osteoarthritis (OA). Dynamic stereo X-ray was used to quantify tibiofemoral joint contact mechanics and frontal-plane motion during the loading response phase of downhill gait in 11 patients with knee OA and 11 control volunteers. Quantitative testing of the quadriceps and the hip abductor muscles was also performed. Patients with knee OA demonstrated larger medial/lateral joint contact point excursions (p < 0.02) and greater heel-strike joint contact point velocities (p < 0.05) for the medial and lateral compartments compared to the control group. The peak medial/lateral joint contact point velocity of the medial compartment was also greater for patients with knee OA compared to their control counterparts (p = 0.02). Additionally, patients with knee OA demonstrated significantly increased frontal-plane varus motion excursions (p < 0.01) and greater quadriceps and hip abductor muscle weakness (p = 0.03). In general, increased joint contact point excursions and velocities in patients with knee OA were linearly associated with greater frontal-plane varus motion excursions (p < 0.04) but not with quadriceps or hip abductor strength. Altered contact mechanics in patients with knee OA may be related to compromised frontal-plane joint stability but not with deficits in muscle strength.

Kinematic predictors of star excursion balance test performance in individuals with chronic ankle instability.

PubMed

Hoch, Matthew C; Gaven, Stacey L; Weinhandl, Joshua T

2016-06-01

The Star Excursion Balance Test has identified dynamic postural control deficits in individuals with chronic ankle instability. While kinematic predictors of Star Excursion Balance Test performance have been evaluated in healthy individuals, this has not been thoroughly examined in individuals with chronic ankle instability. Fifteen individuals with chronic ankle instability completed the anterior reach direction of the Star Excursion Balance Test and weight-bearing dorsiflexion assessments. Maximum reach distances on the Star Excursion Balance Test were measured in cm and normalized to leg length. Three-dimensional trunk, hip, knee, and ankle motion of the stance limb were recorded during each anterior reach trial using a motion capture system. Sagittal, frontal, and transverse plane displacement observed from trial initiation to the point of maximum reach was calculated for each joint or segment and averaged for analysis. Pearson product-moment correlations were performed to examine the relationships between kinematic variables, maximal reach, and weight-bearing dorsiflexion. A backward multiple linear regression model was developed with maximal reach as the criterion variable and kinematic variables as predictors. Frontal plane displacement of the trunk, hip, and ankle and sagittal plane knee displacement were entered into the analysis. The final model (p=0.004) included all three frontal plane variables and explained 81% of the variance in maximal reach. Maximal reach distance and several kinematic variables were significantly related to weight-bearing dorsiflexion. Individuals with chronic ankle instability who demonstrated greater lateral trunk displacement toward the stance limb, hip adduction, and ankle eversion achieved greater maximal reach. Copyright © 2016. Published by Elsevier Ltd.

Design and simulation of a lithium-ion battery with a phase change material thermal management system for an electric scooter

NASA Astrophysics Data System (ADS)

Khateeb, Siddique A.; Farid, Mohammed M.; Selman, J. Robert; Al-Hallaj, Said

A lithium-ion battery employing a novel phase change material (PCM) thermal management system was designed for an electric scooter. Passive thermal management systems using PCM can control the temperature excursions and maintain temperature uniformity in Li-ion batteries without the use of active cooling components such as a fan, a blower or a pump found in air/liquid-cooling systems. Hence, the advantages of a compact, lightweight, and energy efficient system can be achieved with this novel form of thermal management system. Simulation results are shown for a Li-ion battery sub-module consisting of nine 18650 Li-ion cells surrounded by PCM with a melting point between 41 and 44 °C. The use of aluminum foam within the PCM and fins attached to the battery module were studied to overcome the low thermal conductivity of the PCM and the low natural convection heat transfer coefficient. The comparative results of the PCM performance in the presence of Al-foam and Al-fins are shown. The battery module is also simulated for summer and winter conditions. The effect of air-cooling on the Li-ion battery was also studied. These simulation results demonstrate the successful use of the PCM as a potential candidate for thermal management solution in electric scooter applications and therefore for other electric vehicle applications.

Optical frequency comb generation with high tone-to-noise ratio for large-capacity wavelength division multiplexed passive optical network

NASA Astrophysics Data System (ADS)

Ullah, Rahat; Liu, Bo; Zhang, Qi; Tian, Qinghua; Tian, Feng; Qu, Zhaowei; Yan, Cheng; Khan, Muhammad Saad; Ahmad, Ibrar; Xin, Xiangjun

2015-11-01

We propose a technique for the generation of optical frequency comb from a single source, which reduces the costs of optical access networks. Two Mach-Zehnder modulators are cascaded with one phase modulator driven by radiofrequency signals. With 10-GHz frequency spacing, the generated 40 optical multicarriers have good tone-to-noise ratio with least excursions in their comb lines. The laser array at the optical line terminal of the conventional wavelength division multiplexed passive optical network (WDM-PON) system has been replaced with optical frequency comb generator (OFCG), which may result in cost-effective optical line terminal (OLT) supporting a large-capacity WDM-PON system. Of 40 carriers generated, each carrier carries 10 Gbps data based on differential phase-shift keying. Four hundred Gbps multiplexed data from all channels are successfully transmitted through a fiber span of 25 km with negligible power penalties. Part of the downlink signal is used in uplink transmission at optical network unit where intensity-modulated on-off keying is deployed for remodulation. Theoretical analysis of the proposed WDM-PON system based on OFCG are in good agreement with simulation results. The metrics considered for the analysis of the proposed OFCG in a WDM-PON system are power penalties of the full-duplex transmission, eye diagrams, and bit error rate.

Self-amplified CMOS image sensor using a current-mode readout circuit

NASA Astrophysics Data System (ADS)

Santos, Patrick M.; de Lima Monteiro, Davies W.; Pittet, Patrick

2014-05-01

The feature size of the CMOS processes decreased during the past few years and problems such as reduced dynamic range have become more significant in voltage-mode pixels, even though the integration of more functionality inside the pixel has become easier. This work makes a contribution on both sides: the possibility of a high signal excursion range using current-mode circuits together with functionality addition by making signal amplification inside the pixel. The classic 3T pixel architecture was rebuild with small modifications to integrate a transconductance amplifier providing a current as an output. The matrix with these new pixels will operate as a whole large transistor outsourcing an amplified current that will be used for signal processing. This current is controlled by the intensity of the light received by the matrix, modulated pixel by pixel. The output current can be controlled by the biasing circuits to achieve a very large range of output signal levels. It can also be controlled with the matrix size and this permits a very high degree of freedom on the signal level, observing the current densities inside the integrated circuit. In addition, the matrix can operate at very small integration times. Its applications would be those in which fast imaging processing, high signal amplification are required and low resolution is not a major problem, such as UV image sensors. Simulation results will be presented to support: operation, control, design, signal excursion levels and linearity for a matrix of pixels that was conceived using this new concept of sensor.

Metabolic responses to prolonged consumption of glucose- and fructose-sweetened beverages are not associated with postprandial or 24-hour glucose and insulin excursions

USDA-ARS?s Scientific Manuscript database

It has been proposed that the adverse metabolic effects of chronic consumption of sugar-sweetened beverages which contain both glucose and fructose are a consequence of increased circulating glucose and insulin excursions, i.e dietary glycemic index (GI). Objective: We determined if the greater adv...

A Teaching-Learning Sequence of Colour Informed by History and Philosophy of Science

ERIC Educational Resources Information Center

Maurício, Paulo; Valente, Bianor; Chagas, Isabel

2017-01-01

In this work, we present a teaching-learning sequence on colour intended to a pre-service elementary teacher programme informed by History and Philosophy of Science. Working in a socio-constructivist framework, we made an excursion on the history of colour. Our excursion through history of colour, as well as the reported misconception on colour…

A Normative-Speaker Validation Study of Two Indices Developed to Quantify Tongue Dorsum Activity from Midsagittal Tongue Shapes

ERIC Educational Resources Information Center

Zharkova, Natalia

2013-01-01

This study reported adult scores on two measures of tongue shape, based on midsagittal tongue shape data from ultrasound imaging. One of the measures quantified the extent of tongue dorsum excursion, and the other measure represented the place of maximal excursion. Data from six adult speakers of Scottish Standard English without speech disorders…

Tuning the Field Trip: Audio-Guided Tours as a Replacement for 1-Day Excursions in Human Geography

ERIC Educational Resources Information Center

Wissmann, Torsten

2013-01-01

Educators are experiencing difficulties with 1-day field trips in human geography. Instead of teaching students how to apply theory in the field and learn to "sense" geography in everyday life, many excursions have degraded into tourist-like events where lecturers try to motivate rather passive students against a noisy urban backdrop.…

Conference Committees: Conference Committees

NASA Astrophysics Data System (ADS)

2009-09-01

International Programm Committee (IPC) Harald Ade NCSU Sadao Aoki University Tsukuba David Attwood Lawrence Berkeley National Laboratory/CXRO Christian David Paul Scherrer Institut Peter Fischer Lawrence Berkeley National Laboratory Adam Hitchcock McMaster University Chris Jacobsen SUNY, Stony Brook Denis Joyeux Lab Charles Fabry de l'Institut d'Optique Yasushi Kagoshima University of Hyogo Hiroshi Kihara Kansai Medical University Janos Kirz SUNY Stony Brook Maya Kiskinova ELETTRA Ian McNulty Argonne National Lab/APS Alan Michette Kings College London Graeme Morrison Kings College London Keith Nugent University of Melbourne Zhu Peiping BSRF Institute of High Energy Physics Francois Polack Soleil Christoph Quitmann Paul Scherrer Institut Günther Schmahl University Göttingen Gerd Schneider Bessy Hyun-Joon Shin Pohang Accelerator Lab Jean Susini ESRF Mau-Tsu Tang NSRRC Tony Warwick Lawrence Berkeley Lab/ALS Local Organizing Committee Christoph Quitmann Chair, Scientific Program Charlotte Heer Secretary Christian David Scientific Program Frithjof Nolting Scientific Program Franz Pfeiffer Scientific Program Marco Stampanoni Scientific Program Robert Rudolph Sponsoring, Financials Alfred Waser Industry Exhibition Robert Keller Public Relation Markus Knecht Computing and WWW Annick Cavedon Proceedings and Excursions and Accompanying Persons Program Margrit Eichler Excursions and Accompanying Persons Program Kathy Eikenberry Excursions and Accompanying Persons Program Marlies Locher Excursions and Accompanying Persons Program

Age of the Mono Lake excursion and associated tephra

USGS Publications Warehouse

Benson, L.; Liddicoat, J.; Smoot, J.; Sarna-Wojcicki, A.; Negrini, R.; Lund, S.

2003-01-01

The Mono Lake excursion (MLE) is an important time marker that has been found in lake and marine sediments across much of the Northern Hemisphere. Dating of this event at its type locality, the Mono Basin of California, has yielded controversial results with the most recent effort concluding that the MLE may actually be the Laschamp excursion (Earth Planet. Sci. Lett. 197 (2002) 151). We show that a volcanic tephra (Ash #15) that occurs near the midpoint of the MLE has a date (not corrected for reservoir effect) of 28,620 ?? 300 14C yr BP (??? 32,400 GISP2 yr BP) in the Pyramid Lake Basin of Nevada. Given the location of Ash #15 and the duration of the MLE in the Mono Basin, the event occurred between 31,500 and 33,300 GISP2 yr BP, an age range consistent with the position and age of the uppermost of two paleointensity minima in the NAPIS-75 stack that has been associated with the MLE (Philos. Trans. R. Soc. London Ser. A 358 (2000) 1009). The lower paleointensity minimum in the NAPIS-75 stack is considered to be the Laschamp excursion (Philos. Trans. R. Soc. London Ser. A 358 (2000) 1009).

Excursion Processes Associated with Elliptic Combinatorics

NASA Astrophysics Data System (ADS)

Baba, Hiroya; Katori, Makoto

2018-06-01

Researching elliptic analogues for equalities and formulas is a new trend in enumerative combinatorics which has followed the previous trend of studying q-analogues. Recently Schlosser proposed a lattice path model in the square lattice with a family of totally elliptic weight-functions including several complex parameters and discussed an elliptic extension of the binomial theorem. In the present paper, we introduce a family of discrete-time excursion processes on Z starting from the origin and returning to the origin in a given time duration 2 T associated with Schlosser's elliptic combinatorics. The processes are inhomogeneous both in space and time and hence expected to provide new models in non-equilibrium statistical mechanics. By numerical calculation we show that the maximum likelihood trajectories on the spatio-temporal plane of the elliptic excursion processes and of their reduced trigonometric versions are not straight lines in general but are nontrivially curved depending on parameters. We analyze asymptotic probability laws in the long-term limit T → ∞ for a simplified trigonometric version of excursion process. Emergence of nontrivial curves of trajectories in a large scale of space and time from the elementary elliptic weight-functions exhibits a new aspect of elliptic combinatorics.

Excursion Processes Associated with Elliptic Combinatorics

NASA Astrophysics Data System (ADS)

Baba, Hiroya; Katori, Makoto

2018-04-01

Researching elliptic analogues for equalities and formulas is a new trend in enumerative combinatorics which has followed the previous trend of studying q-analogues. Recently Schlosser proposed a lattice path model in the square lattice with a family of totally elliptic weight-functions including several complex parameters and discussed an elliptic extension of the binomial theorem. In the present paper, we introduce a family of discrete-time excursion processes on Z starting from the origin and returning to the origin in a given time duration 2T associated with Schlosser's elliptic combinatorics. The processes are inhomogeneous both in space and time and hence expected to provide new models in non-equilibrium statistical mechanics. By numerical calculation we show that the maximum likelihood trajectories on the spatio-temporal plane of the elliptic excursion processes and of their reduced trigonometric versions are not straight lines in general but are nontrivially curved depending on parameters. We analyze asymptotic probability laws in the long-term limit T → ∞ for a simplified trigonometric version of excursion process. Emergence of nontrivial curves of trajectories in a large scale of space and time from the elementary elliptic weight-functions exhibits a new aspect of elliptic combinatorics.

Gait functional assessment: Spatio-temporal analysis and classification of barefoot plantar pressure in a group of 11-12-year-old children.

PubMed

Latour, Ewa; Latour, Marek; Arlet, Jarosław; Adach, Zdzisław; Bohatyrewicz, Andrzej

2011-07-01

Analysis of pedobarographical data requires geometric identification of specific anatomical areas extracted from recorded plantar pressures. This approach has led to ambiguity in measurements that may underlie the inconsistency of conclusions reported in pedobarographical studies. The goal of this study was to design a new analysis method less susceptible to the projection accuracy of anthropometric points and distance estimation, based on rarely used spatio-temporal indices. Six pedobarographic records per person (three per foot) from a group of 60 children aged 11-12 years were obtained and analyzed. The basis of the analysis was a mutual relationship between two spatio-temporal indices created by excursion of the peak pressure point and the center-of-pressure point on the dynamic pedobarogram. Classification of weight-shift patterns was elaborated and performed, and their frequencies of occurrence were assessed. This new method allows an assessment of body weight shift through the plantar pressure surface based on distribution analysis of spatio-temporal indices not affected by the shape of this surface. Analysis of the distribution of the created index confirmed the existence of typical ways of weight shifting through the plantar surface of the foot during gait, as well as large variability of the intrasubject occurrence. This method may serve as the basis for interpretation of foot functional features and may extend the clinical usefulness of pedobarography. Copyright © 2011 Elsevier B.V. All rights reserved.

Stress-controlled thermoelectric module for energy harvesting and its application for the significant enhancement of the power factor of Bi2Te3-based thermoelectrics

NASA Astrophysics Data System (ADS)

Korobeinikov, Igor V.; Morozova, Natalia V.; Lukyanova, Lidia N.; Usov, Oleg A.; Kulbachinskii, Vladimir A.; Shchennikov, Vladimir V.; Ovsyannikov, Sergey V.

2018-01-01

We propose a model of a thermoelectric module in which the performance parameters can be controlled by applied tuneable stress. This model includes a miniature high-pressure anvil-type cell and a specially designed thermoelectric module that is compressed between two opposite anvils. High thermally conductive high-pressure anvils that can be made, for instance, of sintered technical diamonds with enhanced thermal conductivity, would enable efficient heat absorption or rejection from a thermoelectric module. Using a high-pressure cell as a prototype of a stress-controlled thermoelectric converter, we investigated the effect of applied high pressure on the power factors of several single-crystalline thermoelectrics, including binary p-type Bi2Te3, and multi-component (Bi,Sb)2Te3 and Bi2(Te,Se,S)3 solid solutions. We found that a moderate applied pressure of a few GPa significantly enhances the power factors of some of these thermoelectrics. Thus, they might be more efficiently utilized in stress-controlled thermoelectric modules. In the example of one of these thermoelectrics crystallizing in the same rhombohedral structure, we examined the crystal lattice stability under moderate high pressures. We uncovered an abnormal compression of the rhombohedral lattice of (Bi0.25,Sb0.75)2Te3 along the c-axis in a hexagonal unit cell, and detected two phase transitions to the C2/m and C2/c monoclinic structures above 9.5 and 18 GPa, respectively.

A Venturi microregulator array module for distributed pressure control

PubMed Central

Chang, Dustin S.; Langelier, Sean M.; Zeitoun, Ramsey I.

2010-01-01

Pressure-driven flow control systems are a critical component in many microfluidic devices. Compartmentalization of this functionality into a stand-alone module possessing a simple interface would allow reduction of the number of pneumatic interconnects required for fluidic control. Ideally, such a module would also be sufficiently compact for implementation in portable platforms. In our current work, we show the feasibility of using a modular array of Venturi pressure microregulators for coordinated droplet manipulation. The arrayed microregulators share a single pressure input and are capable of outputting electronically controlled pressures that can be independently set between ±1.3 kPa. Because the Venturi microregulator operates by thermal perturbation of a choked gas flow, this output range corresponds to a temperature variation between 20 and 95°C. Using the array, we demonstrate loading, splitting, merging, and independent movement of multiple droplets in a valveless microchannel network. PMID:20938490

Extraordinary Activity in the BL Lac Object OJ 287

NASA Astrophysics Data System (ADS)

Hughes, P. A.; Aller, H. D.; Aller, M. F.

We present the results of a wavelet transform analysis of data for the BL Lac object OJ 287 acquired as part of the UMRAO variability program. We find clear evidence for a persistent modulation of the total flux and polarization with period 1.66 years, and for another signal that dominates activity in the 1980s with period 1.12 years. It appears that the longer time scale periodicity is associated with an otherwise quiescent jet, and the shorter time scale activity is associated with the passage of a shock, or shocks. The periodic behavior in polarization exhibits excursions in U which correspond to a direction 45circ from the VLBI jet axis. This behavior suggests a small amplitude, cyclic variation in the flow direction in that part of the flow that dominates cm-wavelength emission.

A Quaternary Geomagnetic Instability Time Scale

NASA Astrophysics Data System (ADS)

Singer, B. S.

2013-12-01

Reversals and excursions of Earth's geomagnetic field create marker horizons that are readily detected in sedimentary and volcanic rocks worldwide. An accurate and precise chronology of these geomagnetic field instabilities is fundamental to understanding several aspects of Quaternary climate, dynamo processes, and surface processes. For example, stratigraphic correlation between marine sediment and polar ice records of climate change across the cryospheres benefits from a highly resolved record of reversals and excursions. The temporal patterns of dynamo behavior may reflect physical interactions between the molten outer core and the solid inner core or lowermost mantle. These interactions may control reversal frequency and shape the weak magnetic fields that arise during successive dynamo instabilities. Moreover, weakening of the axial dipole during reversals and excursions enhances the production of cosmogenic isotopes that are used in sediment and ice core stratigraphy and surface exposure dating. The Geomagnetic Instability Time Scale (GITS) is based on the direct dating of transitional polarity states recorded by lava flows using the 40Ar/39Ar method, in parallel with astrochronologic age models of marine sediments in which O isotope and magnetic records have been obtained. A review of data from Quaternary lava flows and sediments yields a GITS comprising 10 polarity reversals and 27 excursions during the past 2.6 million years. Nine of the ten reversals bounding chrons and subchrons are associated with 40Ar/39Ar ages of transitionally-magnetized lava flows. The tenth, the Guass-Matuyama chron boundary, is tightly bracketed by 40Ar/39Ar dated ash deposits. Of the 27 well-documented excursions, 14 occurred during the Matuyama chron and 13 during the Brunhes chron; 19 have been dated directly using the 40Ar/39Ar method on transitionally-magnetized volcanic rocks and form the backbone of the GITS. Excursions are clearly not the rare phenomena once thought. Rather, during the Quaternary period, they occur nearly three times as often as full polarity reversals. I will address analytical issues, including the size and consistency of system blanks, that have led to the recognition of minor (1%) discrepencies between the 40Ar/39Ar age for a particular reversal or excursion and the best astrochronologic estimates from ODP sediment cores. For example, re-analysis of lava flows from Haleakala volcano, Maui that record in detail the Matuyama-Brunhes polarity reversal have been undertaken with blanks an order of magntitude smaller and more stable than was common a decade ago. Using the modern astrochronologic calibration of 28.201 Ma for the age of the Fish Canyon sanidine standard, results thus far yield an 40Ar/39Ar age of 772 × 11 ka for the reversal that is identical to the most precise and accurate astrochronologic age of 773 × 2 ka for this reversal from ODP cores. Similarly, new dating of sanidine in the Cerro Santa Rosa I rhyolite dome, New Mexico reveals an age of 932 × 5 ka for the excursion it records, in perfect agreement with astrochronologically dated ODP core records. Work underway aims at refining the 40Ar/39Ar ages that underpin the entire GITS by further eliminating the bias between the radioisotopic and astrochronologically determined ages for several reversals and excursions.

Right ventricular pressure response to exercise in adults with isolated ventricular septal defect closed in early childhood.

PubMed

Moller, Thomas; Lindberg, Harald; Lund, May Brit; Holmstrom, Henrik; Dohlen, Gaute; Thaulow, Erik

2018-06-01

We previously demonstrated an abnormally high right ventricular systolic pressure response to exercise in 50% of adolescents operated on for isolated ventricular septal defect. The present study investigated the prevalence of abnormal right ventricular systolic pressure response in 20 adult (age 30-45 years) patients who underwent surgery for early ventricular septal defect closure and its association with impaired ventricular function, pulmonary function, or exercise capacity. The patients underwent cardiopulmonary tests, including exercise stress echocardiography. Five of 19 patients (26%) presented an abnormal right ventricular systolic pressure response to exercise ⩾ 52 mmHg. Right ventricular systolic function was mixed, with normal tricuspid annular plane systolic excursion and fractional area change, but abnormal tricuspid annular systolic motion velocity (median 6.7 cm/second) and isovolumetric acceleration (median 0.8 m/second2). Left ventricular systolic and diastolic function was normal at rest as measured by the peak systolic velocity of the lateral wall and isovolumic acceleration, early diastolic velocity, and ratio of early diastolic flow to tissue velocity, except for ejection fraction (median 53%). The myocardial performance index was abnormal for both the left and right ventricle. Peak oxygen uptake was normal (mean z score -0.4, 95% CI -2.8-0.3). There was no association between an abnormal right ventricular systolic pressure response during exercise and right or left ventricular function, pulmonary function, or exercise capacity. Abnormal right ventricular pressure response is not more frequent in adult patients compared with adolescents. This does not support the theory of progressive pulmonary vascular disease following closure of left-to-right shunts.

Respiratory modulation of oscillometric cuff pressure pulses and Korotkoff sounds during clinical blood pressure measurement in healthy adults.

PubMed

Chen, Diliang; Chen, Fei; Murray, Alan; Zheng, Dingchang

2016-05-10

Accurate blood pressure (BP) measurement depends on the reliability of oscillometric cuff pressure pulses (OscP) and Korotkoff sounds (KorS) for automated oscillometric and manual techniques. It has been widely accepted that respiration is one of the main factors affecting BP measurement. However, little is known about how respiration affects the signals from which BP measurement is obtained. The aim was to quantify the modulation effect of respiration on oscillometric pulses and KorS during clinical BP measurement. Systolic and diastolic BPs were measured manually from 40 healthy subjects (from 23 to 65 years old) under normal and regular deep breathing. The following signals were digitally recorded during linear cuff deflation: chest motion from a magnetometer to obtain reference respiration, cuff pressure from an electronic pressure sensor to derive OscP, and KorS from a digital stethoscope. The effects of respiration on both OscP and KorS were determined from changes in their amplitude associated with respiration between systole and diastole. These changes were normalized to the mean signal amplitude of OscP and KorS to derive the respiratory modulation depth. Reference respiration frequency, and the frequencies derived from the amplitude modulation of OscP and KorS were also calculated and compared. Respiratory modulation depth was 14 and 40 % for OscP and KorS respectively under normal breathing condition, with significant increases (both p < 0.05) to 16 and 49 % with deeper breathing. There was no statistically significant difference between the reference respiration frequency and those derived from the oscillometric and Korotkoff signals (both p > 0.05) during deep breathing, and for the oscillometric signal during normal breathing (p > 0.05). Our study confirmed and quantified the respiratory modulation effect on the oscillometric pulses and KorS during clinical BP measurement, with increased modulation depth under regular deeper breathing.

Clayey Landslide Initiation and Acceleration Strongly Modulated by Soil Swelling

NASA Astrophysics Data System (ADS)

Schulz, William H.; Smith, Joel B.; Wang, Gonghui; Jiang, Yao; Roering, Joshua J.

2018-02-01

Largely unknown mechanisms restrain motion of clay-rich, slow-moving landslides that are widespread worldwide and rarely accelerate catastrophically. We studied a clayey, slow-moving landslide typical of thousands in Northern California, USA, to decipher hydrologic-mechanical interactions that modulate landslide dynamics. Similar to some other studies, observed pore-water pressures correlated poorly with landslide reactivation and speed. In situ and laboratory measurements strongly suggested that variable pressure along the landslide's lateral shear boundaries resulting from seasonal soil expansion and contraction modulated its reactivation and speed. Slope-stability modeling suggested that the landslide's observed behavior could be predicted by including transient swell pressure as a resistance term, whereas modeling considering only transient hydrologic conditions predicted movement five to six months prior to when it was observed. All clayey soils swell to some degree; hence, our findings suggest that swell pressure likely modulates motion of many landslides and should be considered to improve forecasts of clayey landslide initiation and mobility.

Clayey landslide initiation and acceleration strongly modulated by soil swelling

USGS Publications Warehouse

Schulz, William; Smith, Joel B.; Wang, Gonghui; Jiang, Yao; Roering, Joshua J.

2018-01-01

Largely unknown mechanisms restrain motion of clay-rich, slow-moving landslides that are widespread worldwide and rarely accelerate catastrophically. We studied a clayey, slow-moving landslide typical of thousands in northern California, USA, to decipher hydrologic-mechanical interactions that modulate landslide dynamics. Similar to some other studies, observed pore-water pressures correlated poorly with landslide reactivation and speed. In situ and laboratory measurements strongly suggested that variable pressure along the landslide's lateral shear boundaries resulting from seasonal soil expansion and contraction modulated its reactivation and speed. Slope-stability modeling suggested that the landslide's observed behavior could be predicted by including transient swell pressure as a resistance term, whereas modeling considering only transient hydrologic conditions predicted movement 5–6 months prior to when it was observed. All clayey soils swell to some degree; hence, our findings suggest that swell pressure likely modulates motion of many landslides and should be considered to improve forecasts of clayey landslide initiation and mobility.

Vibration Sensitivity of a Wide-Temperature Electronically Scanned Pressure Measurement (ESP) Module

NASA Technical Reports Server (NTRS)

Zuckerwar, Allan J.; Garza, Frederico R.

2001-01-01

A vibration sensitivity test was conducted on a Wide-Temperature ESP module. The test object was Module "M4," a 16-channel, 4 psi unit scheduled for installation in the Arc Sector of NTF. The module was installed on a vibration exciter and loaded to positive then negative full-scale pressures (+/-2.5 psid). Test variables were the following: Vibration frequencies: 20, 55, 75 Hz. Vibration level: 1 g. Vibration axes: X, Y, Z. The pressure response was measured on each channel, first without and then with the vibration turned on, and the difference analyzed by means of the statistical t-test. The results show that the vibration sensitivity does not exceed 0.01% Full Scale Output per g (with the exception of one channel on one axis) to a 95 percent confidence level. This specification, limited by the resolution of the pressure source, lies well below the total uncertainty specification of 0.1 percent Full Scale Output.

Ultrasonic speech translator and communications system

DOEpatents

Akerman, M.A.; Ayers, C.W.; Haynes, H.D.

1996-07-23

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system includes an ultrasonic transmitting device and an ultrasonic receiving device. The ultrasonic transmitting device accepts as input an audio signal such as human voice input from a microphone or tape deck. The ultrasonic transmitting device frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output. 7 figs.

Evaluation of pediatric ATD biofidelity as compared to child volunteers in low-speed far-side oblique and lateral impacts.

PubMed

Seacrist, Thomas; Locey, Caitlin M; Mathews, Emily A; Jones, Dakota L; Balasubramanian, Sriram; Maltese, Matthew R; Arbogast, Kristy B

2014-01-01

Motor vehicle crashes are a leading cause of injury and mortality for children. Mitigation of these injuries requires biofidelic anthropomorphic test devices (ATDs) to design and evaluate automotive safety systems. Effective countermeasures exist for frontal and near-side impacts but are limited for far-side impacts. Consequently, far-side impacts represent increased injury and mortality rates compared to frontal impacts. Thus, the objective of this study was to evaluate the biofidelity of the Hybrid III and Q-series pediatric ATDs in low-speed far-side impacts, with and without shoulder belt pretightening. Low-speed (2 g) far-side oblique (60°) and lateral (90°) sled tests were conducted using the Hybrid III and Q-series 6- and 10-year-old ATDs. ATDs were restrained by a lap and shoulder belt equipped with a precrash belt pretightener. Photoreflective targets were attached to the head, spine, shoulders, and sternum. ATDs were exposed to 8 low-speed sled tests: 2 oblique nontightened, 2 oblique pretightened, 2 lateral nontightened, 2 lateral pretightened. ATDs were compared with previously collected 9- to 11-year-old (n=10) volunteer data and newly collected 6- to 8-year-old volunteer data (n=7) tested with similar methods. Kinematic data were collected from a 3D target tracking system. Metrics of comparison included excursion, seat belt and seat pan reaction loads, belt-to-torso angle, and shoulder belt slip-out. The ATDs exhibited increased lateral excursion of the head top, C4, and T1 as well as increased downward excursion of the head top compared to the volunteers. Volunteers exhibited greater forward excursion than the ATDs in oblique nontightened impacts. These kinematics correspond to increased shoulder belt slip-out for the ATDs in oblique tests (ATDs=90%; volunteers=36%). Contrarily, similar shoulder belt slip-out was observed between ATDs and volunteers in lateral impacts (ATDs=80%; volunteers=78%). In pretightened impacts, the ATDs exhibited reduced lateral excursion and torso roll-out angle compared to the volunteers. In general, the ATDs overestimated lateral excursion in both impact directions, while underestimating forward excursion of the head and neck in oblique impacts compared to the pediatric volunteers. This was primarily due to pendulum-like lateral bending of the entire ATD torso compared to translation of the thorax relative to the abdomen prior to the lateral bending of the upper torso in the volunteers, likely due to the multisegmented spinal column in the volunteers. Additionally, the effect of belt pretightening on occupant kinematics was greater for the ATDs than the volunteers.

New successful ideas to teach Earth Science to students older than 55 by means of trekking

NASA Astrophysics Data System (ADS)

Fernández Raga, María; Cerdà, Artemi; Civera, Cristina

2013-04-01

During the last 10 years, the Geograns Program within the NAUGRAN initiative of the University of Valencia is using trekking as a way to teach in the field Earth Science. This paper review the contribution of this program and show the results and future challenges. The life expectancy is growing all over the world. This is a clear trend in the Western societies where after two generations there is a large group of inhabitants that have a new life after retirement. The universities must understand that this new group of citizens need services that will allow them to know better the society. This is why the University of Valencia developed in the end of the 90's a program to teach to students older than 55. The program that allows to those students to attend lectures at the University is called NAUGRAN. This is a program for more than one thousand students that cover the needs of a group that is having more and more population over the age of 55, and with a life expectancy that surpass the 81 years in Spain. Teaching History, Arts, Sciences or Literature can be easily due for those 55-old students. However, teaching geosciences is being very difficult, as the students must visit the field and the laboratory. Within the GEOGRANS project, and during the last six years, Physical Geography was taught to students older than 55 in independent lecture rooms and field and laboratory classes. The main strategy was to show them the concepts and the ideas of the Physical Geography in the field. The excursions allow to shown the main features of the landscape (rivers, mountains, rocks…) and the impacts of the humankind on the changes of the nature to the students. The program is now 6 years old and it is being very successful with more than 200 hundreds participants and with excursion every two weeks. This paper will show the importance of teaching to students that arrive to the university after retirement. And that trekking is a successful strategy as the students realise that they can be active and see the environmental changes suffered but the the land and the society. During the last 10 years more than 100 excursion were done by the Geograns Project. They were mainly one-day excursion, but sometimes two days excursions and one week excursions are done. The three types of excursions are showing positive acceptance of the students.

Deep Space Habitat Configurations Based On International Space Station Systems

NASA Technical Reports Server (NTRS)

Smitherman, David; Russell, Tiffany; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Griffin, Brand; Hornsby, Linda; Maples,Dauphne; Miernik, Janie

2012-01-01

A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits.

Deep Space Habitat Configurations Based on International Space Station Systems

NASA Technical Reports Server (NTRS)

Smitherman, David; Russell, Tiffany; Baysinger, Mike; Capizzo, Pete; Fabisinski, Leo; Griffin, Brand; Hornsby, Linda; Maples, Dauphne; Miernik, Janie

2012-01-01

A Deep Space Habitat (DSH) is the crew habitation module designed for long duration missions. Although humans have lived in space for many years, there has never been a habitat beyond low-Earth-orbit. As part of the Advanced Exploration Systems (AES) Habitation Project, a study was conducted to develop weightless habitat configurations using systems based on International Space Station (ISS) designs. Two mission sizes are described for a 4-crew 60-day mission, and a 4-crew 500-day mission using standard Node, Lab, and Multi-Purpose Logistics Module (MPLM) sized elements, and ISS derived habitation systems. These durations were selected to explore the lower and upper bound for the exploration missions under consideration including a range of excursions within the Earth-Moon vicinity, near earth asteroids, and Mars orbit. Current methods for sizing the mass and volume for habitats are based on mathematical models that assume the construction of a new single volume habitat. In contrast to that approach, this study explored the use of ISS designs based on existing hardware where available and construction of new hardware based on ISS designs where appropriate. Findings included a very robust design that could be reused if the DSH were assembled and based at the ISS and a transportation system were provided for its return after each mission. Mass estimates were found to be higher than mathematical models due primarily to the use of multiple ISS modules instead of one new large module, but the maturity of the designs using flight qualified systems have potential for improved cost, schedule, and risk benefits.

Alkali vapor pressure modulation on the 100 ms scale in a single-cell vacuum system for cold atom experiments

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

Dugrain, Vincent; Reichel, Jakob; Rosenbusch, Peter

2014-08-15

We describe and characterize a device for alkali vapor pressure modulation on the 100 ms timescale in a single-cell cold atom experiment. Its mechanism is based on optimized heat conduction between a current-modulated alkali dispenser and a heat sink at room temperature. We have studied both the short-term behavior during individual pulses and the long-term pressure evolution in the cell. The device combines fast trap loading and relatively long trap lifetime, enabling high repetition rates in a very simple setup. These features make it particularly suitable for portable atomic sensors.

A multi-run chemistry module for the production of [18F]FDG

NASA Astrophysics Data System (ADS)

Sipe, B.; Murphy, M.; Best, B.; Zigler, S.; Lim, J.; Dorman, E.; Mangner, T.; Weichelt, M.

2001-07-01

We have developed a new chemistry module for the production of up to four batches of [18F]FDG. Prior to starting a batch sequence, the module automatically performs a series of self-diagnostic tests, including a reagent detection sequence. The module then executes a user-defined production sequence followed by an automated process to rinse tubing, valves, and the reaction vessel prior to the next production sequence. Process feedback from the module is provided to a graphical user interface by mass flow controllers, radiation detectors, a pressure switch, a pressure transducer, and an IR temperature sensor. This paper will describe the module, the operating system, and the results of multi-site trials, including production data and quality control results.

Time-Resolved Quantitative Analysis of the Diaphragms During Tidal Breathing in a Standing Position Using Dynamic Chest Radiography with a Flat Panel Detector System ("Dynamic X-Ray Phrenicography"): Initial Experience in 172 Volunteers.

PubMed

Yamada, Yoshitake; Ueyama, Masako; Abe, Takehiko; Araki, Tetsuro; Abe, Takayuki; Nishino, Mizuki; Jinzaki, Masahiro; Hatabu, Hiroto; Kudoh, Shoji

2017-04-01

Diaphragmatic motion in a standing position during tidal breathing remains unclear. The purpose of this observational study was to evaluate diaphragmatic motion during tidal breathing in a standing position in a health screening center cohort using dynamic chest radiography in association with participants' demographic characteristics. One hundred seventy-two subjects (103 men; aged 56.3 ± 9.8 years) underwent sequential chest radiographs during tidal breathing using dynamic chest radiography with a flat panel detector system. We evaluated the excursions of and peak motion speeds of the diaphragms. Associations between the excursions and participants' demographics (gender, height, weight, body mass index [BMI], smoking history, tidal volume, vital capacity, and forced expiratory volume) were investigated. The average excursion of the left diaphragm (14.9 ± 4.6 mm, 95% CI 14.2-15.5 mm) was significantly larger than that of the right (11.0 ± 4.0 mm, 95% CI 10.4-11.6 mm) (P <0.001). The peak motion speed of the left diaphragm (inspiratory, 16.6 ± 4.2 mm/s; expiratory, 13.7 ± 4.2 mm/s) was significantly faster than that of the right (inspiratory, 12.4 ± 4.4 mm/s; expiratory, 9.4 ± 3.8 mm/s) (both P <0.001). Both simple and multiple regression models demonstrated that higher BMI and higher tidal volume were associated with increased excursions of the bilateral diaphragm (all P <0.05). The average excursions of the diaphragms are 11.0 mm (right) and 14.9 mm (left) during tidal breathing in a standing position. The diaphragmatic motion of the left is significantly larger and faster than that of the right. Higher BMI and tidal volume are associated with increased excursions of the bilateral diaphragm. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Paleomagnetic Results From the Pleistocene Sediments of Lomonosov Ridge, Central Artic Ocean, IODP Leg 302

NASA Astrophysics Data System (ADS)

King, J. W.; Heil, C.; O'Regan, M.; Moran, K.; Gattacecca, J.; Backman, J.; Jakobsson, M.; Moore, T.

2005-12-01

Two major conclusions can be drawn from magnetic studies of Pleistocene sediments drilled on Lomonosov Ridge, central Arctic Ocean during IODP Leg 302. The first conclusion is that central Arctic Ocean sedimentation rates approach 2 cm/ka during the Pleistocene, thereby resolving the Arctic sedimentation rate controversy in favor of "fast" rates. The second conclusion is that abundant broad intervals of reversed polarity during the Pleistocene are a consistent characteristic of Arctic sedimentary records. These broad reversed intervals have helped perpetuate the Arctic sedimentation rate controversy. The weight of evidence strongly indicates that these reversal intervals are excursions. They do not occur during the late Brunhes Epoch (approximately 0-250,000 BP), but occur during the mid to lower Brunhes Epoch and persist into the upper Matuyama Epoch. We observe a strong correlation between rock magnetic variations, color changes, and physical property stratigraphy and these excursions. The model for Arctic sedimentation indicates that the excursions primarily occur during "interglacial" intervals. Previous high quality paleomagnetic studies of Bermuda Rise sediments have shown that approximately 85 % of Brunhes age excursions occur during interglacial periods (Lund, et al., 2001). In addition, similar excursions do not appear to occur at high southern latitudes (e.g. Acton, et al., 2002). For these reasons, we feel that hypotheses that attribute the interesting observed Arctic paleomagnetic behavior to environmental controls (e.g. sedimentation processes) are favored over those involving geomagnetic field behavior within the tangent cylinder. Acton, G. D., Guyodo, Y., and S. A. Brachfeld, 2002. Magnetostratigraphy of sediment drifts on the continental rise of West Antarctica (ODP Leg 178, Sites 1095, 1096, and 1101). In Barker, P. F., Camerlenghi, A., Acton, G. D., and Ramsay, A.T.S (Eds.), Proc. ODP Sci. Results, v. 178; 1-61 (CD ROM). Lund, S. P., G. D. Acton, B. Clement, M. Okada, and T. Williams. 2001. Brunhes chron magnetics excursions recovered from Leg 172 sediments. In Keigwin, L. D., Rio, D., Acton, G. D., and Arnold, E., (eds.) Proc. ODP Sci. Results, v. 172; p. 1-18 (Online)

Correlation of aptian-albian carbon isotope excursions in continental strata of the cretaceous Foreland Basin, Eastern Utah, U.S.A.

USGS Publications Warehouse

Ludvigson, Greg A.; Joeckel, R.M.; Gonzalez, Luis A.; Gulbranson, E.L.; Rasbury, E.T.; Hunt, G.J.; Kirkland, J.I.; Madsen, S.

2010-01-01

Nodular carbonates ("calcretes") in continental foreland-basin strata of the Early Cretaceous Cedar Mountain Formation (CMF) in eastern Utah yield ??13C and ??O records of changes in the exogenic carbon cycle related to oceanic anoxic events (OAEs), and terrestrial paleoclimate. Chemostratigraphic profiles of both forebulge and foredeep sections show two prominent positive ??13C excursions, each with a peak value of -3% VPDB, and having background ??13C values of about -6% VPDB. These excursions correlate with the global early Aptian (Ap7) and late Aptian-early Albian (Apl2-All) carbon isotope excursions. Aptian-Albian positive ??13C excursions in the CMF also correspond to 3-4 per mil increases in carbonate ??18O. These phenomena record local aridification events. The chemostratigraphic profile on the thinner forebulge section of the CMF is calibrated, for the first time, by a radiogenic U-Pb date of 119.4 ?? 2.6 Ma on a carbonate bed, and by detrital zircon U-Pb dates on two bounding sandstone units (maximum depositional ages of 146 Ma and 112 Ma). P??trographie observations and diagenetic analyses of micritic to microsparitic carbonates from nodules indicate palustrine origins and demonstrate that they crystallized in shallow early meteoric phreatic environments. Meteoric calcite lines derived from CMF carbonates have ??18O values ranging between -8.1 to -7.5%o VPDB, supporting an estimate of zonal mean groundwater ??18O of -6% VSMOW for an Aptian-Albian paleolatitude of 34?? N. Furthermore, our two chemostratigraphic profiles exhibit a generally proportionate thinning of correlative strata from the foredeep on to the forebulge, suggesting that there were consistently lower rates of accumulation on the forebulge during the Aptian-Albian. Identification of the global Aptian-Albian ??13C excursions in purely continental strata, as demonstrated in this paper, opens a new avenue of research by identifying specific stratigraphie intervals that record the terrestrial paleoclimatic impacts of perturbations of the global carbon cycle. Copyright ?? 2010, SEPM (Society for Sedimentary Geology).

Sulfur isotope change across the Early Mississippian K-O (Kinderhookian-Osagean) δ13C excursion

NASA Astrophysics Data System (ADS)

Maharjan, Dev; Jiang, Ganqing; Peng, Yongbo; Nicholl, Michael J.

2018-07-01

Paired carbonate associate sulfate (CAS) sulfur isotopes (δ34SCAS), pyrite sulfur isotopes (δ34SPY) and CAS oxygen isotopes (δ18OCAS) across the Early Mississippian K-O δ13C excursion are documented from two sections of a west-dipping carbonate ramp in the southern Great Basin, western U.S.A. A 4-6‰ positive δ34SCAS anomaly, accompanied by negative shifts in δ34SPY and δ18OCAS, is found within the K-O δ13C excursion. In the section with a broader δ13C excursion, Δ34S (Δ34 S =δ34SCAS-δ34SPY) increases from 15‰ to 45‰ and δ13Ccarb drops from 7‰ to 4‰ at the same stratigraphic interval. If this δ34SCAS anomaly represents a global phenomenon, the large magnitude (4-6‰) and short duration (shorter than that of δ13C) suggest an unusual pyrite burial event that expanded from sediments to the ocean water column. In this scenario, the areal and volumetric expansion of sulfate reduction and pyrite burial was likely triggered by abundantly available organic matter near the peak of the K-O δ13C excursion, during which organic carbon production and burial may have reached a maximum, thus substantially expanding the oxygen minimum zone (OMZ). Numerical simulations suggest that pyrite burial rates 2.5-5 times higher than that of the modern ocean followed by sulfide oxidation are required to produce the observed δ34SCAS anomaly in a sulfate-rich ([SO4] ≥28 mM) Early Mississippian ocean. Alternatively, the sulfur and CAS oxygen isotope anomalies may record local sulfur cycling in a foreland basin where changes in weathering input and bottom-water redox conditions in response to sea-level fall and cooling resulted in isotope changes. In both scenarios (either local or global), the integrated carbon, sulfur, and CAS-oxygen isotope data suggest a much more dynamic sulfur cycle across the K-O δ13C excursion than has been previously suggested.

Application of the FADS system on the Re-entry Module

NASA Astrophysics Data System (ADS)

Zhen, Huang

2016-07-01

The aerodynamic model for Flush Air Data Sensing System (FADS) is built based on the surface pressure distribution obtained through the pressure orifices laid on specific positions of the surface,and the flight parameters,such as angle of attack,angle of side-slip,Mach number,free-stream static pressure and dynamic pressure are inferred from the aerodynamic model.The flush air data sensing system (FADS) has been used on several flight tests of aircraft and re-entry vehicle,such as,X-15,space shuttle,F-14,X-33,X-43A and so on. This paper discusses the application of the FADS on the re-entry module with blunt body to obtain high-precision aerodynamic parameters.First of all,a basic theory and operating principle of the FADS is shown.Then,the applications of the FADS on typical aircrafts and re-entry vehicles are described.Thirdly,the application mode on the re-entry module with blunt body is discussed in detail,including aerodynamic simulation,pressure distribution,trajectory reconstruction and the hardware shoule be used,such as flush air data sensing system(FADS),inertial navigation system (INS),data acquisition system,data storage system.Finally,ablunt module re-entry flight test from low earth orbit (LEO) is planned to obtain aerodynamic parameters and amend the aerodynamic model with this FADS system data.The results show that FADS system can be applied widely in re-entry module with blunt bodies.

KSC-07pd0626

NASA Image and Video Library

2007-03-12

KENNEDY SPACE CENTER, FLA. -- The ship carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module arrives at the Trident wharf after departing from Yokohama, Japan, Feb. 7. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0628

NASA Image and Video Library

2007-03-12

KENNEDY SPACE CENTER, FLA. -- The ship carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module arrives at the Trident wharf after departing from Yokohama, Japan, Feb. 7. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0627

NASA Image and Video Library

2007-03-12

KENNEDY SPACE CENTER, FLA. -- The ship carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module arrives at the Trident wharf after departing from Yokohama, Japan, Feb. 7. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0629

NASA Image and Video Library

2007-03-12

KENNEDY SPACE CENTER, FLA. -- The ship carrying the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module is tied up at the Trident wharf after departing from Yokohama, Japan, Feb. 7. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

Effect of hamstring flexibility on hip and lumbar spine joint excursions during forward-reaching tasks in participants with and without low back pain.

PubMed

Johnson, Erica N; Thomas, James S

2010-07-01

To examine the correlation between hamstring flexibility and hip and lumbar spine joint excursions during standardized reaching and forward-bending tasks. Retrospective analysis of data obtained during 2 previous prospective studies that examined kinematics and kinetics during forward-reaching tasks in participants with and without low back pain (LBP). The 2 previous studies were conducted in the Motor Control Lab at Ohio University and the Orthopaedic Ergonomics Laboratory at The Ohio State University. Data from a total of 122 subjects from 2 previous studies: study 1: 86 subjects recovered from an episode of acute LBP (recovered) and study 2 (A.I. McCallum, unpublished data): 18 chronic LBP subjects and 18 healthy-matched controls (healthy). Not applicable. Correlation values between hamstring flexibility as measured by straight leg raise (SLR) and amount of hip and lumbar spine joint excursions used during standardized reaching and forward-bending tasks. No significant correlation was found between hamstring flexibility and hip and lumbar joint excursions during forward-bending tasks in the LBP or recovered groups. The SLR had a significant negative correlation with lumbar spine excursions during reaching tasks to a low target in the healthy group (right SLR: P=.011, left SLR: P=.004). Hamstring flexibility is not strongly related to the amount of lumbar flexion used to perform forward-reaching tasks in participants who have chronic LBP or who have recovered from LBP. More research needs to be conducted to examine the influence of hamstring flexibility on observed movement patterns to further evaluate the efficacy of flexibility training in the rehabilitation of patients with LBP. Copyright 2010 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Age and Structure of the Laschamp Geomagnetic Excursion

NASA Astrophysics Data System (ADS)

Scaillet, S.; Laj, C.; Kissel, C.; Guillou, H.; Singer, B. S.

2004-12-01

The age of the Laschamp geomagnetic excursion has been recently re-investigated using unspiked K/Ar and Ar/Ar techniques (Guillou et al., Session V01, this conference). The new age determination of 40.4 +/- 2.0 ka (2 sigma) is more precise than those previously reported in the literature and agrees precisely with that deduced from the GLOPIS-75 sedimentary paleointensity stack calibrated against the GISP2 ice core chronology. Two of the North Atlantic cores used in GLOPIS-75 (MD95-2034 and PS2644-5) yield rather detailed transitional VGP paths. In the two cases the paths show large similarities, with the VGP initially descending along mid-western Pacific, then returning to normal polarities with a large clockwise loop over Africa and Europe. Differences in the highest southern latitudes reached by the VGP can be explained assuming more different degrees of smearing of the paleomagnetic record due to differences in sedimentation rate in the two cores. In the most detailed record, MD95-2034 , two smaller loops are present preceding the main excursion. In the two cores, the excursion is characterized by a significant drop in intensity. The reversal paths observed for the Laschamp event are very close in position to those reported for the Icelandic Basin Event (IBE) from sites in the North Atlantic and the South China Sea (Laj et al., this conference) but differ in the sense of looping: while a clockwise loop is observed here, a counterclockwise loop is observed for the IBE. Despite this difference, the similarity of the transitional records tends to suggest that a similar, relatively simple, geometry has dominated the two excursions and therefore that similar dynamo mechanisms have prevailed during the reversal process.

40Ar/ 39Ar, K-Ar and 230Th- 238U dating of the Laschamp excursion: A radioisotopic tie-point for ice core and climate chronologies

NASA Astrophysics Data System (ADS)

Singer, Brad S.; Guillou, Hervé; Jicha, Brian R.; Laj, Carlo; Kissel, Catherine; Beard, Brian L.; Johnson, Clark M.

2009-08-01

A brief period of enhanced 10Be flux that straddles the interstadial warm period known as Dansgaard-Oeschger event 10 in Greenland and its counterpart in Antarctica, the Antarctic Isotope Maximum 10 is but one consequence of the weakening of Earth's magnetic field associated with the Laschamp excursion. This 10Be peak measured in the GRIP ice core is dated at 41,250 y b2k (= before year 2000 AD) in the most recent GICC05 age model obtained from the NorthGRIP core via multi-parameter counting of annual layers. Uncertainty in the age of the 10Be peak is, however, no better than ± 1630 y at the 95% confidence level, reflecting accumulated error in identifying annual layers. The age of the Laschamp excursion [Guillou, H., Singer, B.S., Laj, C., Kissel, C., Scaillet, S., Jicha, B., 2004. On the age of the Laschamp geomagnetic excursion. Earth Planet. Sci. Lett. 227, 331-343.] is revised on the basis of new 40Ar/ 39Ar, unspiked K-Ar and 238U- 230Th data from three lava flows in the Massif Central, France, together with the 40Ar/ 39Ar age of a transitionally magnetized lava flow at Auckland, New Zealand. Combined, these data yield an age of 40,700 ± 950 y b2k, where the uncertainty includes both analytical and systematic ( 40K and 230Th decay constant) errors. Taking the radioisotopic age as a calibration tie point suggests that the layer-counting chronologies for the NorthGRIP and GISP2 ice cores are more accurate and precise than previously thought at depths corresponding to the Laschamp excursion.

Constraints on Early Triassic carbon cycle dynamics from paired organic and inorganic carbon isotope records

NASA Astrophysics Data System (ADS)

Meyer, K. M.; Yu, M.; Lehrmann, D.; van de Schootbrugge, B.; Payne, J. L.

2013-01-01

Large δ13C excursions, anomalous carbonate precipitates, low diversity assemblages of small fossils, and evidence for marine euxinia in uppermost Permian and Lower Triassic strata bear more similarity to Neoproterozoic carbonates than to the remainders of the Permian and Triassic systems. Middle Triassic diversification of marine ecosystems coincided with the waning of anoxia and stabilization of the global carbon cycle, suggesting that environment-ecosystem linkages were important to biological recovery. However, the Earth system behavior responsible for these large δ13C excursions remains poorly constrained. Here we present a continuous Early Triassic δ13Corg record from south China and use it to test the extent to which Early Triassic excursions in δ13Ccarb record changes in the δ13C of marine dissolved inorganic carbon (DIC). Regression analysis demonstrates a significant positive correlation between δ13Corg and δ13Ccarb across multiple sections that span a paleoenvironmental gradient. Such a correlation is incompatible with diagenetic alteration because no likely mechanism will alter both δ13Corg and δ13Ccarb records in parallel and therefore strongly indicates a primary depositional origin. A simple explanation for this correlation is that a substantial portion of the preserved Corg was derived from the contemporaneous DIC pool, implying that the observed excursions reflect variation in the δ13C of the exogenic carbon reservoir (ocean, atmosphere, biomass). These findings support existing evidence that large δ13C excursions are primary and therefore strengthen the case that large-scale changes to the carbon cycle were mechanistically linked to the low diversity and small size of Early Triassic fossils. Associated sedimentary and biogeochemical phenomena further suggest that similar associations in Neoproterozoic and Cambrian strata may reflect the same underlying controls.

Agreement Between Visual Assessment and 2-Dimensional Analysis During Jump Landing Among Healthy Female Athletes.

PubMed

Rabin, Alon; Einstein, Ofira; Kozol, Zvi

2018-04-01

  Altered movement patterns, including increased frontal-plane knee movement and decreased sagittal-plane hip and knee movement, have been associated with several knee disorders. Nevertheless, the ability of clinicians to visually detect such altered movement patterns during high-speed athletic tasks is relatively unknown.   To explore the association between visual assessment and 2-dimensional (2D) analysis of frontal-plane knee movement and sagittal-plane hip and knee movement during a jump-landing task among healthy female athletes.   Cross-sectional study.   Gymnasiums of participating volleyball teams.   A total of 39 healthy female volleyball players (age = 21.0 ± 5.2 years, height = 172.0 ± 8.6 cm, mass = 64.2 ± 7.2 kg) from Divisions I and II of the Israeli Volleyball Association.   Frontal-plane knee movement and sagittal-plane hip and knee movement during jump landing were visually rated as good, moderate, or poor based on previously established criteria. Frontal-plane knee excursion and sagittal-plane hip and knee excursions were measured using free motion-analysis software and compared among athletes with different visual ratings of the corresponding movements.   Participants with different visual ratings of frontal-plane knee movement displayed differences in 2D frontal-plane knee excursion ( P < .01), whereas participants with different visual ratings of sagittal-plane hip and knee movement displayed differences in 2D sagittal-plane hip and knee excursions ( P < .01).   Visual ratings of frontal-plane knee movement and sagittal-plane hip and knee movement were associated with differences in the corresponding 2D hip and knee excursions. Visual rating of these movements may serve as an initial screening tool for detecting altered movement patterns during jump landings.

Eyelid reanimation with gold weight implant and tendon sling suspension: evaluation of excursion and velocity using the FACIAL CLIMA system.

PubMed

Hontanilla, Bernardo; Marre, Diego

2013-04-01

This study aims to analyse the efficacy of static techniques, namely gold weight implant and tendon sling, in the reanimation of the paralytic eyelid. Upper eyelid rehabilitation in terms of excursion and blinking velocity is performed using the automatic motion capture system, FACIAL CLIMA. Seventy-four patients underwent a total of 101 procedures including 58 upper eyelid gold weight implants and 43 lower eyelid tendon suspension with 27 patients undergoing both procedures. The presence of lagophtalmos, eye dryness, corneal ulcer, epiphora and lower lid ptosis/ectropion was assessed preoperatively. The Wilcoxon signed-rank test was used to compare preoperative versus postoperative measurements of upper eyelid excursion and blinking velocity determined with FACIAL CLIMA. Significance was set at p <0.05. FACIAL CLIMA revealed significant improvement of eyelid excursion and velocity of blinking (p < 0.001). Eye dryness improved in 49 patients (90.7%) and corneal ulcer resolved without any further treatment in 12 (85.7%) of those with a gold weight inserted. Implant extrusion was observed in 8.6% of the cases. Of the patients with lower lid tendon suspension, correction of ptosis/ectropion and epiphora was achieved in 93.9% and 91.9% of cases, respectively. In eight patients (18.6%), further surgery was needed to adjust tendon tension. The paralytic upper and lower eyelid can be successfully managed with gold weight implant and tendon suspension. The FACIAL CLIMA system is a reliable method to quantify upper eyelid excursion and blinking velocity and to detect the exact position of the lower eyelid. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Mandibular kinematic changes after unilateral cross-bite with lateral shift correction.

PubMed

Venancio, F; Alarcon, J A; Lenguas, L; Kassem, M; Martin, C

2014-10-01

The aim of this randomised prospective study was to evaluate the effects of slow maxillary expansion with expansion plates and Hyrax expanders on the kinematics of the mandible after cross-bite correction. Thirty children (15 boys and 15 girls), aged 7·1-11·8, with unilateral cross-bite and functional shift were divided into two groups: expansion plate (n = 15) and Hyrax expander (n = 15). Thirty children with normal occlusion (14 boys and 16 girls, aged 7·3-11·6) served as control group. The maximum vertical opening, lateral mandibular shift (from maximum vertical opening to maximum intercuspation, from rest position to maximum intercuspation and from maximum vertical opening to rest position) and lateral excursions were recorded before and 4 months after treatment. After treatment, the expansion plate group showed a greater lateral shift from rest position to maximum intercuspation than did the control group. The expansion plate patients also presented greater left/contralateral excursion than did the control group. Comparisons of changes after treatment in the cross-bite groups showed significant decreases in the lateral shift from the maximum vertical opening to maximum intercuspation and from the maximum vertical opening to rest position, a significant increase in the homolateral excursion and a significant decrease in the contralateral excursion in the Hyrax expander group, whereas no significant differences were found in the expansion plate group. In conclusion, the Hyrax expander showed better results than did the expansion plate. The Hyrax expander with acrylic occlusal covering significantly improved the mandibular lateral shift and normalised the range of lateral excursion. © 2014 John Wiley & Sons Ltd.

An investigation of the dynamic relationship between navicular drop and first metatarsophalangeal joint dorsal excursion

PubMed Central

Griffin, Nicole L; Miller, Charlotte; Schmitt, Daniel; D'Août, Kristiaan

2013-01-01

The modern human foot is a complex biomechanical structure that must act both as a shock absorber and as a propulsive strut during the stance phase of gait. Understanding the ways in which foot segments interact can illuminate the mechanics of foot function in healthy and pathological humans. It has been proposed that increased values of medial longitudinal arch deformation can limit metatarsophalangeal joint excursion via tension in the plantar aponeurosis. However, this model has not been tested directly in a dynamic setting. In this study, we tested the hypothesis that during the stance phase, subtalar pronation (stretching of the plantar aponeurosis and subsequent lowering of the medial longitudinal arch) will negatively affect the amount of first metatarsophalangeal joint excursion occurring at push-off. Vertical descent of the navicular (a proxy for subtalar pronation) and first metatarsophalangeal joint dorsal excursion were measured during steady locomotion over a flat substrate on a novel sample consisting of asymptomatic adult males and females, many of whom are habitually unshod. Least-squares regression analyses indicated that, contrary to the hypothesis, navicular drop did not explain a significant amount of variation in first metatarsophalangeal joint dorsal excursion. These results suggest that, in an asymptomatic subject, the plantar aponeurosis and the associated foot bones can function effectively within the normal range of subtalar pronation that takes place during walking gait. From a clinical standpoint, this study highlights the need for investigating the in vivo kinematic relationship between subtalar pronation and metatarsophalangeal joint dorsiflexion in symptomatic populations, and also the need to explore other factors that may affect the kinematics of asymptomatic feet. PMID:23600634

Tonic Investigation Concept of Cervico-vestibular Muscle Afferents

PubMed Central

Dorn, Linda Josephine; Lappat, Annabelle; Neuhuber, Winfried; Scherer, Hans; Olze, Heidi; Hölzl, Matthias

2016-01-01

Introduction Interdisciplinary research has contributed greatly to an improved understanding of the vestibular system. To date, however, very little research has focused on the vestibular system's somatosensory afferents. To ensure the diagnostic quality of vestibular somatosensory afferent data, especially the extra cranial afferents, stimulation of the vestibular balance system has to be precluded. Objective Sophisticated movements require intra- and extra cranial vestibular receptors. The study's objective is to evaluate an investigation concept for cervico-vestibular afferents with respect to clinical feasibility. Methods A dedicated chair was constructed, permitting three-dimensional trunk excursions, during which the volunteer's head remains fixed. Whether or not a cervicotonic provocation nystagmus (c-PN) can be induced with static trunk excursion is to be evaluated and if this can be influenced by cervical monophasic transcutaneous electrical nerve stimulation (c-TENS) with a randomized test group. 3D-video-oculography (VOG) was used to record any change in cervico-ocular examination parameters. The occurring nystagmuses were evaluated visually due to the small caliber of nystagmus amplitudes in healthy volunteers. Results The results demonstrate: no influence of placebo-controlled c-TENS on the spontaneous nystagmus; a significant increase of the vertical nystagmus on the 3D-trunk-excursion chair in static trunk flexion with cervical provocation in all young healthy volunteers (n = 49); and a significant difference between vertical and horizontal nystagmuses during static trunk excursion after placebo-controlled c-TENS, except for the horizontal nystagmus during trunk torsion. Conclusion We hope this cervicotonic investigation concept on the 3D trunk-excursion chair will contribute to new diagnostic and therapeutic perspectives on cervical pathologies in vestibular head-to-trunk alignment. PMID:28050208

Dosimetric Considerations in Respiratory-Gated Deep Inspiration Breath-Hold for Left Breast Irradiation.

PubMed

Walston, Steve; Quick, Allison M; Kuhn, Karla; Rong, Yi

2017-02-01

To present our clinical workflow of incorporating AlignRT for left breast deep inspiration breath-hold treatments and the dosimetric considerations with the deep inspiration breath-hold protocol. Patients with stage I to III left-sided breast cancer who underwent lumpectomy or mastectomy were considered candidates for deep inspiration breath-hold technique for their external beam radiation therapy. Treatment plans were created on both free-breathing and deep inspiration breath-hold computed tomography for each patient to determine whether deep inspiration breath-hold was beneficial based on dosimetric comparison. The AlignRT system was used for patient setup and monitoring. Dosimetric measurements and their correlation with chest wall excursion and increase in left lung volume were studied for free-breathing and deep inspiration breath-hold plans. Deep inspiration breath-hold plans had significantly increased chest wall excursion when compared with free breathing. This change in geometry resulted in reduced mean and maximum heart dose but did not impact lung V 20 or mean dose. The correlation between chest wall excursion and absolute reduction in heart or lung dose was found to be nonsignificant, but correlation between left lung volume and heart dose showed a linear association. It was also identified that higher levels of chest wall excursion may paradoxically increase heart or lung dose. Reduction in heart dose can be achieved for many left-sided breast and chest wall patients using deep inspiration breath-hold. Chest wall excursion as well as left lung volume did not correlate with reduction in heart dose, and it remains to be determined what metric will provide the most optimal and reliable dosimetric advantage.

Multiple High-Frequency Carbon Isotope Excursions Across the Precambrian-Cambrian Boundary: Implications for Correlations and Environmental Change

NASA Astrophysics Data System (ADS)

Smith, E. F.; Macdonald, F. A.; Schrag, D. P.; Laakso, T.

2014-12-01

The GSSP Precambrian-Cambrian boundary in Newfoundland is defined by the first appearance datum (FAD) of Treptichnus pedum, which is considered to be roughly coincident with the FAD of small shelly fossils (SSFs) and a large negative carbon isotope excursion. An association between the FAD of T. pedum and a negative carbon isotope excursion has previously been documented in Northwest Canada (Narbonne et al., 1994) and Death Valley (Corsetti and Hagadorn, 2000), and since then has been used as an chronostratigraphic marker of the boundary, particularly in siliciclastic poor sections that do not preserve T. pedum. Here we present new high-resolution carbon isotope (δ13C ) chemostratigraphy from multiple sections in western Mongolia and the western United States that span the Ediacaran-Cambrian transition. High-resolution sampling (0.2-1 m) reveals that instead of one large negative excursion, there are multiple, high-frequency negative excursions with an overall negative trend during the latest Ediacaran. These data help to more precisely calibrate changes in the carbon cycle across the boundary as well as to highlight the potential problem of identifying the boundary with just a few negative δ13C values. We then use a simple carbon isotope box model to explore relationships between phosphorous delivery to the ocean, oxygenation, alkalinity, and turnovers in carbonate secreting organisms. Corsetti, F.A., and Hagadorn, J.W., 2000, Precambrian-Cambrian transition: Death Valley, United States: Geology, v. 28, no. 4, p. 299-302. Narbonne, G.M., Kaufman, A.J., and Knoll, A.H., 1994, Integrated chemostratigraphy and biostratigraphy of the Windermere Supergroup, northwestern Canada: Implications for Neoproterozoic correlations and the early evolution of animals: Geological Society of America Bulletin, v. 106, no. 10, p. 1281-1292.

KSC-07pd0633

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, workers help guide the container with the Experiment Logistics Module Pressurized Section inside toward a flat bed on the dock. The logistics module is part of the Japanese Experiment Module. The logistics module will be transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0634

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, workers help guide the container with the Experiment Logistics Module Pressurized Section inside onto a flat bed on the dock. The logistics module is part of the Japanese Experiment Module. The logistics module will be transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

KSC-07pd0631

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, workers in the hold of a ship attach a crane to the shipping container with the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module. The ship brought the module from Yokohama, Japan. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

Spin polarization of {sup 87}Rb atoms with ultranarrow linewidth diode laser: Numerical simulation

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

Wang, Z. G.; Interdisciplinary Center of Quantum Information, National University of Defense Technology, Changsha, 410073; College of Science, National University of Defense Technology, Changsha, 410073

2016-08-15

In order to polarize {sup 87}Rb vapor effectively with ultranarrow linewidth diode laser, we studied the polarization as a function of some parameters including buffer gas pressure and laser power. Moreover, we also discussed the methods which split or modulate the diode laser frequency so as to pump the two ground hyperfine levels efficiently. We obtained some useful results through numerical simulation. If the buffer gas pressure is so high that the hyperfine structure is unresolved, the polarization is insensitive to laser frequency at peak absorption point so frequency splitting and frequency modulation methods do not show improvement. At lowmore » pressure and laser power large enough, where the hyperfine structure is clearly resolved, frequency splitting and frequency modulation methods can increase polarization effectively. For laser diodes, frequency modulation is easily realized with current modulation, so this method is attractive since it does not add any other components in the pumping laser system.« less

Fluid Viscosity Affects the Fragmentation and Inertial Cavitation Threshold of Lipid-Encapsulated Microbubbles.

PubMed

Helfield, Brandon; Black, John J; Qin, Bin; Pacella, John; Chen, Xucai; Villanueva, Flordeliza S

2016-03-01

Ultrasound and microbubble optimization studies for therapeutic applications are often conducted in water/saline, with a fluid viscosity of 1 cP. In an in vivo context, microbubbles are situated in blood, a more viscous fluid (∼4 cP). In this study, ultrahigh-speed microscopy and passive cavitation approaches were employed to investigate the effect of fluid viscosity on microbubble behavior at 1 MHz subject to high pressures (0.25-2 MPa). The propensity for individual microbubble (n = 220) fragmentation was found to significantly decrease in 4-cP fluid compared with 1-cP fluid, despite achieving similar maximum radial excursions. Microbubble populations diluted in 4-cP fluid exhibited decreased wideband emissions (up to 10.2 times), and increasingly distinct harmonic emission peaks (e.g., ultraharmonic) with increasing pressure, compared with those in 1-cP fluid. These results suggest that in vitro studies should consider an evaluation using physiologic viscosity perfusate before transitioning to in vivo evaluations. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Officials welcome the arrival of the Japanese Experiment Module

NASA Image and Video Library

2007-04-17

In the Space Station Processing Facility, Scott Higginbotham, payload manager for the International Space Station, discusses the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module (JEM), with Dr. Hidetaka Tanaka, the JEM Project Team resident manager at KSC for the Japanese Aerospace and Exploration Agency (JAXA). Earlier, NASA and JAXA officials welcomed the arrival of the module. The new International Space Station component arrived at Kennedy March 12 to begin preparations for its future launch on mission STS-123. It will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module.

Systems and methods for pressure and temperature measurement

DOEpatents

Challener, William Albert; Airey, Li

2016-12-06

A measurement system in one embodiment includes an acquisition module and a determination module. The acquisition module is configured to acquire resonant frequency information corresponding to a sensor disposed in a remote location from the acquisition module. The resonant frequency information includes first resonant frequency information for a first resonant frequency of the sensor corresponding to environmental conditions of the remote location, and also includes second resonant frequency information for a different, second resonant frequency of the sensor corresponding to the environmental conditions of the remote location. The determination module is configured to use the first resonant frequency information and the second resonant frequency information to determine the temperature and the pressure at the remote location.

KSC-07pd0903

NASA Image and Video Library

2007-04-17

KENNEDY SPACE CENTER, FLA. -- The Japanese Experiment Module (JEM) sits on top of a stand in the Space Station Processing Facility. Earlier, NASA and Japanese Aerospace and Exploration Agency (JAXA) officials welcomed the arrival of the Experiment Logistics Module Pressurized Section of the JEM, which will be delivered to the space station on mission STS-123. The JEM will fly on mission STS-124. The module will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module. Photo credit: NASA/George Shelton

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto (center) gets information about the facility while on a tour of KSC. Behind the group is the Japanese Experiment Module (JEM)/pressurized module. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of JEM.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, Executive Director of NASDA Koji Yamamoto (center) gets information about the facility while on a tour of KSC. Behind the group is the Japanese Experiment Module (JEM)/pressurized module. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of JEM.

Progress Toward Efficient Laminar Flow Analysis and Design

NASA Technical Reports Server (NTRS)

Campbell, Richard L.; Campbell, Matthew L.; Streit, Thomas

2011-01-01

A multi-fidelity system of computer codes for the analysis and design of vehicles having extensive areas of laminar flow is under development at the NASA Langley Research Center. The overall approach consists of the loose coupling of a flow solver, a transition prediction method and a design module using shell scripts, along with interface modules to prepare the input for each method. This approach allows the user to select the flow solver and transition prediction module, as well as run mode for each code, based on the fidelity most compatible with the problem and available resources. The design module can be any method that designs to a specified target pressure distribution. In addition to the interface modules, two new components have been developed: 1) an efficient, empirical transition prediction module (MATTC) that provides n-factor growth distributions without requiring boundary layer information; and 2) an automated target pressure generation code (ATPG) that develops a target pressure distribution that meets a variety of flow and geometry constraints. The ATPG code also includes empirical estimates of several drag components to allow the optimization of the target pressure distribution. The current system has been developed for the design of subsonic and transonic airfoils and wings, but may be extendable to other speed ranges and components. Several analysis and design examples are included to demonstrate the current capabilities of the system.

Entry Dispersion Analysis for the Stardust Comet Sample Return Capsule

NASA Technical Reports Server (NTRS)

Desai, Prasun N.; Mitcheltree, Robert A.; Cheatwood, F. McNeil

1997-01-01

Stardust will be the first mission to return samples from beyond the Earth-Moon system. The sample return capsule, which is passively controlled during the fastest Earth entry ever, will land by parachute in Utah. The present study analyzes the entry, descent, and landing of the returning sample capsule. The effects of two aerodynamic instabilities are revealed (one in the high altitude free molecular regime and the other in the transonic/subsonic flow regime). These instabilities could lead to unacceptably large excursions in the angle-of-attack near peak heating and main parachute deployment, respectively. To reduce the excursions resulting from the high altitude instability, the entry spin rate of the capsule is increased. To stabilize the excursions from the transonic/subsonic instability, a drogue chute with deployment triggered by an accelerometer and timer is added prior to main parachute deployment. A Monte Carlo dispersion analysis of the modified entry (from which the impact of off-nominal conditions during the entry is ascertained) shows that the capsule attitude excursions near peak heating and drogue chute deployment are within Stardust program limits. Additionally, the size of the resulting 3-sigma landing ellipse is 83.5 km in downrange by 29.2 km in crossrange, which is within the Utah Test and Training Range boundaries.

Recognizing the Albian-Cenomanian (OAE1d) sequence boundary using plant carbon isotopes: Dakota Formation, Western Interior Basin, USA

USGS Publications Warehouse

Grocke, D.R.; Ludvigson, Greg A.; Witzke, B.L.; Robinson, S.A.; Joeckel, R.M.; Ufnar, David F.; Ravn, R.L.

2006-01-01

Analysis of bulk sedimentary organic matter and charcoal from an Albian-Cenomanian fluvial-estuarine succession (Dakota Formation) at Rose Creek Pit (RCP), Nebraska, reveals a negative excursion of ???3???, in late Albian strata. Overlying Cenomanian strata have ??13C values of -24???, to -23???, that are similar to pre-excursion values. The absence of an intervening positive excursion (as exists in marine records of the Albian-Cenomanian boundary) likely results from a depositional hiatus. The corresponding positive ??13C event and proposed depositional hiatus are concordant with a regionally identified sequence boundary in the Dakota Formation (D2), as well as a major regressive phase throughout the globe at the Albian-Cenomanian boundary. Data from RCP confirm suggestions that some positive carbon-isotope excursions in the geologic record are coincident with regressive sea-level phases. We estimate using isotopic correlation that the D2 sequence boundary at RCP was on the order of 0.5 m.y. in duration. Therefore, interpretations of isotopic events and associated environmental phenomena, such as oceanic anoxic events, in the shallow-marine and terrestrial record may be influenced by stratigraphic incompleteness. Further investigation of terrestrial ??13C records may be useful in recognizing and constraining sea-level changes in the geologic record. ?? 2006 Geological Society of America.

The Laschamp geomagnetic excursion featured in nitrate record from EPICA-Dome C ice core

PubMed Central

Traversi, R.; Becagli, S.; Poluianov, S.; Severi, M.; Solanki, S. K.; Usoskin, I. G.; Udisti, R.

2016-01-01

Here we present the first direct comparison of cosmogenic 10Be and chemical species in the period of 38–45.5 kyr BP spanning the Laschamp geomagnetic excursion from the EPICA-Dome C ice core. A principal component analysis (PCA) allowed to group different components as a function of the main sources, transport and deposition processes affecting the atmospheric aerosol at Dome C. Moreover, a wavelet analysis highlighted the high coherence and in-phase relationship between 10Be and nitrate at this time. The evident preferential association of 10Be with nitrate rather than with other chemical species was ascribed to the presence of a distinct source, here labelled as “cosmogenic”. Both the PCA and wavelet analyses ruled out a significant role of calcium in driving the 10Be and nitrate relationship, which is particularly relevant for a plateau site such as Dome C, especially in the glacial period during which the Laschamp excursion took place. The evidence that the nitrate record from the EDC ice core is able to capture the Laschamp event hints toward the possibility of using this marker for studying galactic cosmic ray flux variations and thus also major geomagnetic field excursions at pluri-centennial-millennial time scales, thus opening up new perspectives in paleoclimatic studies. PMID:26819064

A reassessment of the role of tidal dispersion in estuaries and bays

USGS Publications Warehouse

Geyer, W. Rockwell; Signell, Richard P.

1992-01-01

The role of tidal dispersion is reassessed, based on a consideration of the relevant physical mechanisms, particularly those elucidated by numerical simulations of tide-induced dispersion. It appears that the principal influence of tidal currents on dispersion occurs at length scales of the tidal excursion and smaller; thus the effectiveness of tidal dispersion depends on the relative scale of the tidal excursion to the spacing between major bathymetric and shoreline features. In estuaries where the typical spacing of topographic features is less than the tidal excursion, tidal dispersion may contribute significantly to the overall flushing. In estuaries and embayments in which the typical spacing between major features is larger than the tidal excursion, the influence of tidal dispersion will be localized, and it will not markedly contribute to overall flushing. Tidal dispersion is most pronounced in regions of abrupt topographic changes such as headlands and inlets, where flow separation occurs. The strong strain rate in the region of flow separation tends to stretch patches of fluid into long filaments, which are subsequently rolled up and distorted by the transient eddy field. The dispersion process accomplished by the tides varies strongly as a function of position and tidal phase and thus does not lend itself to parameterization by an eddy diffusion coefficient.

Officials welcome the arrival of the Japanese Experiment Module

NASA Image and Video Library

2007-04-17

In the Space Station Processing Facility, astronaut Takao Doi (left) and Commander Dominic Gorie pose in front of the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module, or JEM, that recently arrived at Kennedy. Doi and Gorie are crew members for mission STS-123 that will deliver the logistics module to the International Space Station. Earlier, NASA and Japanese Aerospace and Exploration Agency (JAXA) officials welcomed the arrival of the module. The new International Space Station component arrived at Kennedy March 12 to begin preparations for its future launch on mission STS-123. It will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module.

KENNEDY SPACE CENTER, FLA. - On a KSC visit, Executive Director of NASDA Koji Yamamoto (kneeling, left) reaches out to a piece of Columbia debris in the Columbia Debris Hangar. At right is Shuttle Launch Director Mike Leinbach, who is explaining recovery and reconstruction efforts. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

NASA Image and Video Library

2003-06-12

KENNEDY SPACE CENTER, FLA. - On a KSC visit, Executive Director of NASDA Koji Yamamoto (kneeling, left) reaches out to a piece of Columbia debris in the Columbia Debris Hangar. At right is Shuttle Launch Director Mike Leinbach, who is explaining recovery and reconstruction efforts. Mr. Yamamoto is at KSC for a welcome ceremony involving the arrival of the newest Space Station module, the Japanese Experiment Module/pressurized module.

Ion transport membrane module and vessel system with directed internal gas flow

DOEpatents

Holmes, Michael Jerome; Ohrn, Theodore R.; Chen, Christopher Ming-Poh

2010-02-09

An ion transport membrane system comprising (a) a pressure vessel having an interior, an inlet adapted to introduce gas into the interior of the vessel, an outlet adapted to withdraw gas from the interior of the vessel, and an axis; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region; and (c) one or more gas flow control partitions disposed in the interior of the pressure vessel and adapted to change a direction of gas flow within the vessel.

Preliminary feasibility analysis of a pressure modulator radiometer for remote sensing of tropospheric constituents

NASA Technical Reports Server (NTRS)

Orr, H. D., III; Rarig, P. L.

1981-01-01

A pressure modulator radiometer operated in a nadir viewing mode from the top of a midlatitude summer model of the atmosphere was theoretically studied for monitoring the mean volumetric mixing ratio of carbon monoxide in the troposphere. The mechanical characteristics of the instrument on the Nimbus 7 stratospheric and mesospheric sounder experiment are assumed and CO is assumed to be the only infrared active constituent. A line by line radiative transfer computer program is used to simulate the upwelling radiation reaching the top of the atmosphere. The performance of the instrument is examined as a function of the mean pressure in and the length of the instrument gas correlation cell. Instrument sensitivity is described in terms of signal to noise ratio for a 10 percent change in CO mixing ratio. Sensitivity to mixing ratio changes is also studied. It is concluded that tropospheric monitoring requires a pressure modulator drive having a larger swept volume and producing higher compression ratios at higher mean cell pressures than the Nimbus 7 design.

KENNEDY SPACE CENTER, FLA. - At Port Canaveral, the Pressurized Module of the Japanese Experiment Module (JEM) is lifted out of the ship’s cargo hold. The container transport ship carrying JEM departed May 2 from Yokohama Harbor in Japan for the voyage to the United States. The National Space Development Agency of Japan (NASDA) developed the laboratory at the Tsukuba Space Center near Tokyo. The Pressurized Module is the first element of the JEM, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

NASA Image and Video Library

2003-06-04

KENNEDY SPACE CENTER, FLA. - At Port Canaveral, the Pressurized Module of the Japanese Experiment Module (JEM) is lifted out of the ship’s cargo hold. The container transport ship carrying JEM departed May 2 from Yokohama Harbor in Japan for the voyage to the United States. The National Space Development Agency of Japan (NASDA) developed the laboratory at the Tsukuba Space Center near Tokyo. The Pressurized Module is the first element of the JEM, named "Kibo" (Hope), to be delivered to KSC. The JEM is Japan's primary contribution to the Station. It will enhance the unique research capabilities of the orbiting complex by providing an additional environment for astronauts to conduct science experiments. The JEM also includes an exposed facility (platform) for space environment experiments, a robotic manipulator system, and two logistics modules. The various JEM components will be assembled in space over the course of three Shuttle missions.

Development and testing of thermal energy storage modules for use in active solar heating and cooling systems

NASA Technical Reports Server (NTRS)

Parker, J. C.

1981-01-01

The project development requirements and criteria are presented along with technical data for the modules. Performance tests included: ducting, temperature, pressure and air flow measurements, dry and wet bulb temperature; duct pressure measurements; and air conditioning apparatus checks; installation, operation, and maintenance instructions are included.

Ultrasonic speech translator and communications system

DOEpatents

Akerman, M. Alfred; Ayers, Curtis W.; Haynes, Howard D.

1996-01-01

A wireless communication system undetectable by radio frequency methods for converting audio signals, including human voice, to electronic signals in the ultrasonic frequency range, transmitting the ultrasonic signal by way of acoustical pressure waves across a carrier medium, including gases, liquids, or solids, and reconverting the ultrasonic acoustical pressure waves back to the original audio signal. The ultrasonic speech translator and communication system (20) includes an ultrasonic transmitting device (100) and an ultrasonic receiving device (200). The ultrasonic transmitting device (100) accepts as input (115) an audio signal such as human voice input from a microphone (114) or tape deck. The ultrasonic transmitting device (100) frequency modulates an ultrasonic carrier signal with the audio signal producing a frequency modulated ultrasonic carrier signal, which is transmitted via acoustical pressure waves across a carrier medium such as gases, liquids or solids. The ultrasonic receiving device (200) converts the frequency modulated ultrasonic acoustical pressure waves to a frequency modulated electronic signal, demodulates the audio signal from the ultrasonic carrier signal, and conditions the demodulated audio signal to reproduce the original audio signal at its output (250).

Heart Rate and Blood Pressure Variability under Moon, Mars and Zero Gravity Conditions During Parabolic Flights

NASA Astrophysics Data System (ADS)

Aerts, Wouter; Joosen, Pieter; Widjaja, Devy; Varon, Carolina; Vandeput, Steven; Van Huffel, Sabine; Aubert, Andre E.

2013-02-01

Gravity changes during partial-G parabolic flights (0g -0.16g - 0.38g) lead to changes in modulation of the autonomic nervous system (ANS), studied via the heart rate variability (HRV) and blood pressure variability (BPV). HRV and BPV were assessed via classical time and frequency domain measures. Mean systolic and diastolic blood pressure show both increasing trends towards higher gravity levels. The parasympathetic and sympathetic modulation show both an increasing trend with decreasing gravity, although the modulation is sympathetic predominant during reduced gravity. For the mean heart rate, a non-monotonic relation was found, which can be explained by the increased influence of stress on the heart rate. This study shows that there is a relation between changes in gravity and modulations in the ANS. With this in mind, countermeasures can be developed to reduce postflight orthostatic intolerance.

Indoor modeling of the wind pressure in solar installations with flat and step-like frames for HCPV modules

NASA Astrophysics Data System (ADS)

Rumyantsev, Valery D.; Ashcheulov, Yury V.; Chekalin, Alexander V.; Chumakov, Yury S.; Shvarts, Maxim Z.; Timofeev, Vladimir V.

2014-09-01

As a rule, the HCPV modules are mounted on solar trackers in a form of a flat panel. Wind pressure is one of the key factors limiting the operation capabilities of such type solar installations. At the PV Lab of the Ioffe Institute, the sun-trackers with step-like frame for modules have been proposed and developed, which have a potential for significant reduction of wind pressure. Such a reduction is realized in a wide range of the frame tilt angles the most typical for day-light operation of solar installations. In the present work, theoretical consideration and indoor experiments with mechanical models of installation frames have been carried out. A wind tunnel has been used as an experimental instrument for quantitative comparison in conventional units of expected wind loads on module frames of different designs.

Microinjection of acetylcholine into cerebellar fastigial nucleus induces blood depressor response in anesthetized rats.

PubMed

Zhang, Changzheng; Luo, Wen; Zhou, Peiling; Sun, Tingzhe

2016-08-26

It is well known that the cerebellar fastigial nucleus (FN) is involved in cardiovascular modulation, and has direct evidence of cholinergic activity; however, whether and how acetylcholine (ACh) in the FN modulates blood pressure has not been investigated. In this study, we analyzed mean arterial pressure, maximal change in mean arterial pressure, and the reaction time of blood pressure changes after microinjection of cholinergic reagents into the FN in anesthetized rats. The results showed that ACh evoked a concentration-dependent (10, 30 and 100mM) effect on blood pressure down-regulation. The muscarinic ACh (mACh) receptor antagonist atropine, but not the nicotinic ACh (nACh) receptor antagonist mecamylamine, blocked the ACh-mediated depressor response. The mACh receptor agonist oxotremorine M, rather than nACh receptor agonist nicotine, mimicked the ACh-mediated blood pressure decrease in a dose-dependent manner (10, 30 and 100mM). These results indicate that cholinergic input in the cerebellar FN exerts a depressor effect on systemic blood pressure regulation, and such effects are substantially contributed by mACh rather than nACh receptors, although the precise mechanism concerning the role of mACh receptor in FN-mediated blood pressure modulation remains to be elucidated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Support arrangement for core modules of nuclear reactors

DOEpatents

Bollinger, Lawrence R.

1987-01-01

A support arrangement is provided for the core modules of a nuclear reactor which provides support access through the control drive mechanisms of the reactor. This arrangement provides axial support of individual reactor core modules from the pressure vessel head in a manner which permits attachment and detachment of the modules from the head to be accomplished through the control drive mechanisms after their leadscrews have been removed. The arrangement includes a module support nut which is suspended from the pressure vessel head and screw threaded to the shroud housing for the module. A spline lock prevents loosening of the screw connection. An installation tool assembly, including a cell lifting and preloading tool and a torquing tool, fits through the control drive mechanism and provides lifting of the shroud housing while disconnecting the spline lock, as well as application of torque to the module support nut.

Support arrangements for core modules of nuclear reactors. [PWR

DOEpatents

Bollinger, L.R.

1983-11-03

A support arrangement is provided for the core modules of a nuclear reactor which provides support access through the control drive mechanisms of the reactor. This arrangement provides axial support of individual reactor core modules from the pressure vessel head in a manner which permits attachment and detachment of the modules from the head to be accomplished through the control drive mechanisms after their leadscrews have been removed. The arrangement includes a module support nut which is suspended from the pressure vessel head and screw threaded to the shroud housing for the module. A spline lock prevents loosening of the screw connection. An installation tool assembly, including a cell lifting and preloading tool and a torquing tool, fits through the control drive mechanism and provides lifting of the shroud housing while disconnecting the spline lock, as well as application of torque to the module support nut.

Coupled incompressible Smoothed Particle Hydrodynamics model for continuum-based modelling sediment transport

NASA Astrophysics Data System (ADS)

Pahar, Gourabananda; Dhar, Anirban

2017-04-01

A coupled solenoidal Incompressible Smoothed Particle Hydrodynamics (ISPH) model is presented for simulation of sediment displacement in erodible bed. The coupled framework consists of two separate incompressible modules: (a) granular module, (b) fluid module. The granular module considers a friction based rheology model to calculate deviatoric stress components from pressure. The module is validated for Bagnold flow profile and two standardized test cases of sediment avalanching. The fluid module resolves fluid flow inside and outside porous domain. An interaction force pair containing fluid pressure, viscous term and drag force acts as a bridge between two different flow modules. The coupled model is validated against three dambreak flow cases with different initial conditions of movable bed. The simulated results are in good agreement with experimental data. A demonstrative case considering effect of granular column failure under full/partial submergence highlights the capability of the coupled model for application in generalized scenario.

Is inflation from unwinding fluxes IIB?

NASA Astrophysics Data System (ADS)

Gautason, Fridrik Freyr; Schillo, Marjorie; Van Riet, Thomas

2017-03-01

In this paper we argue that the mechanism of unwinding inflation is naturally present in warped compactifications of type IIB string theory with local throats. The unwinding of flux is caused by its annihilation against branes. The resulting inflaton potential is linear with periodic modulations. We initiate an analysis of the inflationary dynamics and cosmological observables, which are highly constrained by moduli stabilization. For the simplified model of single-Kähler Calabi-Yau spaces we find that many, though not all of the consistency constraints can be satisfied. Particularly, in this simple model geometric constraints are in tension with obtaining the observed amplitude of the scalar power spectrum. However, we do find 60 efolds of inflation with a trans-Planckian field excursion which offers the hope that slightly more complicated models can lead to a fully consistent explicit construction of large field inflation of this kind.

Thermodynamic analysis of energy density in pressure retarded osmosis: The impact of solution volumes and costs

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

Reimund, Kevin K.; McCutcheon, Jeffrey R.; Wilson, Aaron D.

A general method was developed for estimating the volumetric energy efficiency of pressure retarded osmosis via pressure-volume analysis of a membrane process. The resulting model requires only the osmotic pressure, π, and mass fraction, w, of water in the concentrated and dilute feed solutions to estimate the maximum achievable specific energy density, uu, as a function of operating pressure. The model is independent of any membrane or module properties. This method utilizes equilibrium analysis to specify the volumetric mixing fraction of concentrated and dilute solution as a function of operating pressure, and provides results for the total volumetric energy densitymore » of similar order to more complex models for the mixing of seawater and riverwater. Within the framework of this analysis, the total volumetric energy density is maximized, for an idealized case, when the operating pressure is π/(1+√w⁻¹), which is lower than the maximum power density operating pressure, Δπ/2, derived elsewhere, and is a function of the solute osmotic pressure at a given mass fraction. It was also found that a minimum 1.45 kmol of ideal solute is required to produce 1 kWh of energy while a system operating at “maximum power density operating pressure” requires at least 2.9 kmol. Utilizing this methodology, it is possible to examine the effects of volumetric solution cost, operation of a module at various pressure, and operation of a constant pressure module with various feed.« less

TECHNICAL REVIEW OF ZPR-I ACCIDENTAL TRANSIENT--THE POWER EXCURSION, EXPOSURES, AND CLINICAL DATA

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

Brittan, R. O.; Hasterlik, R. J.; Marinelli, L. D.

1953-01-26

On June 2. 1952. a large reactivity change was made manually in a ZPR-1 assembly causing a power excursion of about one kwh, which resulted in damage to the reactor core components and radiation exposure of some of the operating personnel to perhaps several hundred rep. A description is presented of the incident, estimates are made of the exposures, and early clinical data are summarized. (C.H.)

Working and Learning in a Field Excursion.

PubMed

Hole, Torstein Nielsen

2018-06-01

This study aimed to discern sociocultural processes through which students learn in field excursions. To achieve this aim, short-term ethnographic techniques were employed to examine how undergraduate students work and enact knowledge (or knowing) during a specific field excursion in biology. The students participated in a working practice that employed research methods and came to engage with various biological phenomena over the course of their work. A three-level analysis of the students' experiences focused on three processes that emerged: participatory appropriation, guided participation, and apprenticeship. These processes derive from advances in practice-oriented theories of knowing. Through their work in the field, the students were able to enact science autonomously; they engaged with peers and teachers in specific ways and developed new understandings about research and epistemology founded on their experiences in the field. Further discussion about the use of "practice" and "work" as analytical concepts in science education is also included.

A Vendian-Cambrian boundary succession from the northwestern margin of the Siberian Platform: stratigraphy, palaeontology, chemostratigraphy and correlation

NASA Technical Reports Server (NTRS)

Bartley, J. K.; Pope, M.; Knoll, A. H.; Semikhatov, M. A.; Grotzinger, J. (Principal Investigator)

1998-01-01

Siberia contains several key reference sections for studies of biological and environmental evolution across the Proterozoic-Phanerozoic transition. The Platonovskaya Formation, exposed in the Turukhansk region of western Siberia, is an uppermost Proterozoic to Cambrian succession whose trace and body fossils place broad limits on the age of deposition, but do not permit detailed correlation with boundary successions elsewhere. In contrast, a striking negative carbon isotopic excursion in the lower part of the Platonovskaya Formation permits precise chemostratigraphic correlation with upper-most Yudomian successions in Siberia, and possibly worldwide. In addition to providing a tool for correlation, the isotopic excursion preserved in the Platonovskaya and contemporaneous successions documents a major biogeochemical event, likely involving the world ocean. The excursion coincides with the palaeontological breakpoint between Ediacaran- and Cambrian-style assemblages, suggesting a role for biogeochemical change in evolutionary events near the Proterozoic Cambrian boundary.

Turbulence flight director analysis and preliminary simulation

NASA Technical Reports Server (NTRS)

Johnson, D. E.; Klein, R. E.

1974-01-01

A control column and trottle flight director display system is synthesized for use during flight through severe turbulence. The column system is designed to minimize airspeed excursions without overdriving attitude. The throttle system is designed to augment the airspeed regulation and provide an indication of the trim thrust required for any desired flight path angle. Together they form an energy management system to provide harmonious display indications of current aircraft motions and required corrective action, minimize gust upset tendencies, minimize unsafe aircraft excursions, and maintain satisfactory ride qualities. A preliminary fixed-base piloted simulation verified the analysis and provided a shakedown for a more sophisticated moving-base simulation to be accomplished next. This preliminary simulation utilized a flight scenario concept combining piloting tasks, random turbulence, and discrete gusts to create a high but realistic pilot workload conducive to pilot error and potential upset. The turbulence director (energy management) system significantly reduced pilot workload and minimized unsafe aircraft excursions.

A Vendian-Cambrian boundary succession from the northwestern margin of the Siberian Platform: stratigraphy, palaeontology, chemostratigraphy and correlation.

PubMed

Bartley, J K; Pope, M; Knoll, A H; Semikhatov, M A; Petrov PYu

1998-07-01

Siberia contains several key reference sections for studies of biological and environmental evolution across the Proterozoic-Phanerozoic transition. The Platonovskaya Formation, exposed in the Turukhansk region of western Siberia, is an uppermost Proterozoic to Cambrian succession whose trace and body fossils place broad limits on the age of deposition, but do not permit detailed correlation with boundary successions elsewhere. In contrast, a striking negative carbon isotopic excursion in the lower part of the Platonovskaya Formation permits precise chemostratigraphic correlation with upper-most Yudomian successions in Siberia, and possibly worldwide. In addition to providing a tool for correlation, the isotopic excursion preserved in the Platonovskaya and contemporaneous successions documents a major biogeochemical event, likely involving the world ocean. The excursion coincides with the palaeontological breakpoint between Ediacaran- and Cambrian-style assemblages, suggesting a role for biogeochemical change in evolutionary events near the Proterozoic Cambrian boundary.

Bounded excursion stable gravastars and black holes

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

Rocha, P; Miguelote, A Y; Chan, R

2008-06-15

Dynamical models of prototype gravastars were constructed in order to study their stability. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of stiff fluid divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. It is found that in some cases the models represent the 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in other cases they collapse until the formation of black holes occurs. In the phase space, the region for the 'bounded excursion' gravastars ismore » very small in comparison to that of black holes, but not empty. Therefore, although the possibility of the existence of gravastars cannot be excluded from such dynamical models, our results indicate that, even if gravastars do indeed exist, that does not exclude the possibility of the existence of black holes.« less

KSC-07pd0630

NASA Image and Video Library

2007-03-13

KENNEDY SPACE CENTER, FLA. -- At the Trident wharf, the shipping container with the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module is ready for lifting out of the hold of the ship that brought it from Yokohama, Japan. The logistics module will be offloaded and transported to the Space Station Processing Facility at NASA's Kennedy Space Center. The Japanese Experiment Module is composed of three segments and is known as Kibo, which means "hope" in Japanese. Kibo consists of six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. Kibo also has a scientific airlock through which experiments are transferred and exposed to the external environment of space. Kibo is Japan's first human space facility and its primary contribution to the station. Kibo will enhance the unique research capabilities of the orbiting complex by providing an additional environment in which astronauts can conduct science experiments. The various components of JEM will be assembled in space over the course of three Space Shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the Space Shuttle Endeavour, targeted for launch in 2007. Photo credit: NASA/Kim Shiflett

Officials welcome the arrival of the Japanese Experiment Module

NASA Image and Video Library

2007-04-17

In the Space Station Processing Facility, NASA and Japanese Aerospace and Exploration Agency (JAXA) officials welcome the arrival of the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module, or JEM, to the Kennedy Space Center. Seen here at right are JAXA representatives, including Japanese astronaut Takao Doi (center of front row), who is a crew member for mission STS-123 that will deliver the module to the space station. The new International Space Station component arrived at Kennedy March 12 to begin preparations for its future launch on mission STS-123. It will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module.

Glycaemic Profiles of Children With Overweight and Obesity in Free-living Conditions in Association With Cardiometabolic Risk.

PubMed

Rijks, Jesse; Karnebeek, Kylie; van Dijk, Jan-Willem; Dorenbos, Elke; Gerver, Willem-Jan; Stouthart, Pauline; Plat, Jogchum; Vreugdenhil, Anita

2016-08-18

Insulin resistance is common among children with overweight and obesity. However, knowledge about glucose fluctuations in these children is scarce. This study aims to evaluate glycaemic profiles in children with overweight and obesity in free-living conditions, and to examine the association between glycaemic profiles with insulin resistance and cardiovascular risk parameters. One hundred eleven children with overweight and obesity were included. 48-hour sensor glucose concentrations in free-living conditions, fasting plasma and post-glucose load concentrations, serum lipid and lipoprotein concentrations, homeostatic model assessment of insulin resistance (HOMA-IR), and blood pressure were evaluated. Hyperglycaemic glucose excursions (≥7.8 mmol/L) were observed in 25% (n = 28) of the children. The median sensor glucose concentration was 5.0 (2.7-7.3) mmol/L, and correlated with fasting plasma glucose concentrations (rs = 0.190, p = 0.046), serum insulin concentrations (rs = 0.218, p = 0.021), and HOMA-IR (rs = 0.230, p = 0.015). The hyperglycaemic area under the curve (AUC) correlated with waist circumference z-score (rs = 0.455, p = 0.025), triacylglycerol concentrations (rs = 0.425, p = 0.024), and HOMA-IR (rs = 0.616, p < 0.001). In conclusion, hyperglycaemic glucose excursions are frequently observed in children with overweight and obesity in free-living conditions. Children with insulin resistance had higher median sensor glucose concentrations and a larger hyperglycaemic sensor glucose AUC, which are both associated with specific parameters predicting cardiovascular disease risk.

Diffusion of radon through concrete block walls: A significant source of indoor radon

USGS Publications Warehouse

Lively, R.S.; Goldberg, L.F.

1999-01-01

Basement modules located in southern Minnesota have been the site of continuous radon and environmental measurements during heating seasons since 1993. Concentrations of radon within the basement modules ranged from 70 Bq.m-3 to over 4000 Bq.m-3 between November to April during the three measurement periods. In the soil gas for the same times, concentrations of radon ranged between 25,000 and 70,000 Bq.m-3. Levels of radon within the basement modules changed by factors of five or more within 24 h, in concert with pressure gradients of 4 to 20 Pa that developed between the basement modules and their surroundings. Diffusion is identified as the principal method by which radon is transferred into and out of the basement modules, and appears to be relatively independent of insulating materials and vapour retarders. The variability of radon and correlations with differential pressure gradients may be related to air currents in the block walls and soil that interrupt radon diffusing inward. This yields a net decrease of radon in the basement modules by decay and outward diffusion. Levels of radon within the basement modules increase when the pressure differential is zero and air flow ceases, allowing diffusion gradients to be re-established. Radon levels in both the soil and the basement modules then increase until an equilibrium is achieved.

Continuous Positive Airway Pressure for Motion Management in Stereotactic Body Radiation Therapy to the Lung: A Controlled Pilot Study

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

Goldstein, Jeffrey D.; Lawrence, Yaacov R.; Sackler School of Medicine, Tel Aviv University, Tel Aviv

Objective: To determine the effect of continuous positive airway pressure (CPAP) on tumor motion, lung volume, and dose to critical organs in patients receiving stereotactic body radiation therapy (SBRT) for lung tumors. Methods and Materials: After institutional review board approval in December 2013, patients with primary or secondary lung tumors referred for SBRT underwent 4-dimensional computed tomographic simulation twice: with free breathing and with CPAP. Tumor excursion was calculated by subtracting the vector of the greatest dimension of the gross tumor volume (GTV) from the internal target volume (ITV). Volumetric and dosimetric determinations were compared with the Wilcoxon signed-rank test.more » CPAP was used during treatment if judged beneficial. Results: CPAP was tolerated well in 10 of the 11 patients enrolled. Ten patients with 18 lesions were evaluated. The use of CPAP decreased tumor excursion by 0.5 ± 0.8 cm, 0.4 ± 0.7 cm, and 0.6 ± 0.8 cm in the superior–inferior, right–left, and anterior–posterior planes, respectively (P≤.02). Relative to free breathing, the mean ITV reduction was 27% (95% confidence interval [CI] 16%-39%, P<.001). CPAP significantly augmented lung volume, with a mean absolute increase of 915 ± 432 cm{sup 3} and a relative increase of 32% (95% CI 21%-42%, P=.003), contributing to a 22% relative reduction (95% CI 13%-32%, P=.001) in mean lung dose. The use of CPAP was also associated with a relative reduction in mean heart dose by 29% (95% CI 23%-36%, P=.001). Conclusion: In this pilot study, CPAP significantly reduced lung tumor motion compared with free breathing. The smaller ITV, the planning target volume (PTV), and the increase in total lung volume associated with CPAP contributed to a reduction in lung and heart dose. CPAP was well tolerated, reproducible, and simple to implement in the treatment room and should be evaluated further as a novel strategy for motion management in radiation therapy.« less

Thermal modelling of various thermal barrier coatings in a high heat flux rocket engine

NASA Technical Reports Server (NTRS)

Nesbitt, James A.

1989-01-01

Traditional Air Plasma Sprayed (APS) ZrO2-Y2O3 Thermal Barrier Coatings (TBC's) and Low Pressure Plasma Sprayed (LPPS) ZrO2-Y2O3/Ni-Cr-Al-Y cermet coatings were tested in a H2/O2 rocked engine. The traditional ZrO2-Y2O3 (TBC's) showed considerable metal temperature reductions during testing in the hydrogen-rich environment. A thermal model was developed to predict the thermal response of the tubes with the various coatings. Good agreement was observed between predicted temperatures and measured temperatures at the inner wall of the tube and in the metal near the coating/metal interface. The thermal model was also used to examine the effect of the differences in the reported values of the thermal conductivity of plasma sprayed ZrO2-Y2O3 ceramic coatings, the effect of 100 micron (0.004 in.) thick metallic bond coat, the effect of tangential heat transfer around the tube, and the effect or radiation from the surface of the ceramic coating. It was shown that for the short duration testing in the rocket engine, the most important of these considerations was the effect of the uncertainty in the thermal conductivity of temperatures (greater than 100 C) predicted in the tube. The thermal model was also used to predict the thermal response of the coated rod in order to quantify the difference in the metal temperatures between the two substrate geometries and to explain the previously-observed increased life of coatings on rods over that on tubes. A thermal model was also developed to predict heat transfer to the leading edge of High Pressure Fuel Turbopump (HPFTP) blades during start-up of the space shuttle main engines. The ability of various TBC's to reduce metal temperatures during the two thermal excursions occurring on start-up was predicted. Temperature reductions of 150 to 470 C were predicted for 165 micron (0.0065 in.) coatings for the greater of the two thermal excursions.

Early-phase prandial insulin secretion: its role in the pathogenesis of type 2 diabetes mellitus and its modulation by repaglinide.

PubMed

Owens, D R; Cozma, L S; Luzio, S D

2002-12-01

The major contributory factor to increasing hyperglycaemia in established Type 2 diabetes mellitus (T2DM) appears to be the progressive delay and attenuation of the prandial insulin response. An important consequence of this derangement is that hepatic glucose production is no longer suppressed during times of prandial glucose intake. Together with a relative impairment in the rate of peripheral glucose disposal, this leads to supra-physiological plasma glucose excursions, which may damage the vasculature. An obvious therapeutic strategy, therefore, would be to increase insulin availability when most needed--in the early prandial phase. In experiments with exogenous insulin interventions, peak post-prandial blood glucose increments were curtailed without undue increases in total insulin exposure. However, available evidence suggests that the sulphonylurea glibenclamide does not effectively alter early-phase prandial insulin release but predominately increases late-phase and basal insulin output, thus incurring the risk of hypoglycaemia. The novel insulin secretagogue repaglinide, by contrast, augments early-phase prandial insulin secretion when taken before meals, as shown by studies in non-diabetic people and patients with newly diagnosed, previously untreated T2DM. Repaglinide exerts its greatest effect on the insulin secretion rate during the first 30 min after a meal is started, thereby going some way to restoring the early insulin secretion curve seen after a meal in non-diabetic people. No residual secretagogue activity is seen 4 hr after taking a single dose of up to 2 mg. Prandial glucose regulation with repaglinide could be associated with lower post-prandial glucose excursions and less risk of post-prandial hypoglycaemia than glibenclamide.

Acoustic characteristics of simulated respiratory-induced vocal tremor.

PubMed

Lester, Rosemary A; Story, Brad H

2013-05-01

The purpose of this study was to investigate the relation of respiratory forced oscillation to the acoustic characteristics of vocal tremor. Acoustical analyses were performed to determine the characteristics of the intensity and fundamental frequency (F0) for speech samples obtained by Farinella, Hixon, Hoit, Story, and Jones (2006) using a respiratory forced oscillation paradigm with 5 healthy adult males to simulate vocal tremor involving respiratory pressure modulation. The analyzed conditions were sustained productions of /a/ with amplitudes of applied pressure of 0, 1, 2, and 4 cmH2O and a rate of 5 Hz. Forced oscillation of the respiratory system produced modulation of the intensity and F0 for all participants. Variability was observed between participants and conditions in the change in intensity and F0 per unit of pressure change, as well as in the mean intensity and F0. However, the extent of modulation of intensity and F0 generally increased as the applied pressure increased, as would be expected. These findings suggest that individuals develop idiosyncratic adaptations to pressure modulations, which are important to understanding aspects of variability in vocal tremor, and highlight the need to assess all components of the speech mechanism that may be directly or indirectly affected by tremor.

USE OF POSITIVE PRESSURE IN THE BARIATRIC SURGERY AND EFFECTS ON PULMONARY FUNCTION AND PREVALENCE OF ATELECTASIS: RANDOMIZED AND BLINDED CLINICAL TRIAL

PubMed Central

BALTIERI, Letícia; SANTOS, Laisa Antonela; RASERA-JUNIOR, Irineu; MONTEBELO, Maria Imaculada Lima; PAZZIANOTTO-FORTI, Eli Maria

2014-01-01

Background In surgical procedures, obesity is a risk factor for the onset of intra and postoperative respiratory complications. Aim Determine what moment of application of positive pressure brings better benefits on lung function, incidence of atelectasis and diaphragmatic excursion, in the preoperative, intraoperative or immediate postoperative period. Method Randomized, controlled, blinded study, conducted in a hospital and included subjects with BMI between 40 and 55 kg/m2, 25 and 55 years, underwent bariatric surgery by laparotomy. They were underwent preoperative and postoperative evaluations. They were allocated into four different groups: 1) Gpre: treated with positive pressure in the BiPAP mode (Bi-Level Positive Airway Pressure) before surgery for one hour; 2) Gpos: BIPAP after surgery for one hour; 3) Gintra: PEEP (Positive End Expiratory Pressure) at 10 cmH2O during the surgery; 4) Gcontrol: only conventional respiratory physiotherapy. The evaluation consisted of anthropometric data, pulmonary function tests and chest radiography. Results Were allocated 40 patients, 10 in each group. There were significant differences for the expiratory reserve volume and percentage of the predicted expiratory reserve volume, in which the groups that received treatment showed a smaller loss in expiratory reserve volume from the preoperative to postoperative stages. The postoperative radiographic analysis showed a 25% prevalence of atelectasis for Gcontrol, 11.1% for Gintra, 10% for Gpre, and 0% for Gpos. There was no significant difference in diaphragmatic mobility amongst the groups. Conclusion The optimal time of application of positive pressure is in the immediate postoperative period, immediately after extubation, because it reduces the incidence of atelectasis and there is reduction of loss of expiratory reserve volume. PMID:25409961

Use of positive pressure in the bariatric surgery and effects on pulmonary function and prevalence of atelectasis: randomized and blinded clinical trial.

PubMed

Baltieri, Letícia; Santos, Laisa Antonela; Rasera, Irineu; Montebelo, Maria Imaculada Lima; Pazzianotto-Forti, Eli Maria

2014-01-01

In surgical procedures, obesity is a risk factor for the onset of intra and postoperative respiratory complications. Determine what moment of application of positive pressure brings better benefits on lung function, incidence of atelectasis and diaphragmatic excursion, in the preoperative, intraoperative or immediate postoperative period. Randomized, controlled, blinded study, conducted in a hospital and included subjects with BMI between 40 and 55 kg/m2, 25 and 55 years, underwent bariatric surgery by laparotomy. They were underwent preoperative and postoperative evaluations. They were allocated into four different groups: 1) Gpre: treated with positive pressure in the BiPAP mode (Bi-Level Positive Airway Pressure) before surgery for one hour; 2) Gpos: BIPAP after surgery for one hour; 3) Gintra: PEEP (Positive End Expiratory Pressure) at 10 cmH2O during the surgery; 4) Gcontrol: only conventional respiratory physiotherapy. The evaluation consisted of anthropometric data, pulmonary function tests and chest radiography. Were allocated 40 patients, 10 in each group. There were significant differences for the expiratory reserve volume and percentage of the predicted expiratory reserve volume, in which the groups that received treatment showed a smaller loss in expiratory reserve volume from the preoperative to postoperative stages. The postoperative radiographic analysis showed a 25% prevalence of atelectasis for Gcontrol, 11.1% for Gintra, 10% for Gpre, and 0% for Gpos. There was no significant difference in diaphragmatic mobility amongst the groups. The optimal time of application of positive pressure is in the immediate postoperative period, immediately after extubation, because it reduces the incidence of atelectasis and there is reduction of loss of expiratory reserve volume.

Modulated infrared radiant source

NASA Technical Reports Server (NTRS)

Stewart, W. F.; Edwards, S. F.; Vann, D. S.; Mccormick, R. F.

1981-01-01

A modulated, infrared radiant energy source was developed to calibrate an airborne nadir-viewing pressure modulated radiometer to be used to detect from Earth orbit trace gases in the troposphere. The technique used an 8 cm long, 0.005 cm diameter platinum-iridium wire as an isothermal, thin line radiant energy source maintained at 1200 K. A + or - 20 K signal, oscillating at controllable frequencies from dc to 20 Hz, was superimposed on it. This periodic variation of the line source energy was used to verify the pressure modulated radiometer's capability to distinguish between the signal variations caused by the Earth's background surface and the signal from the atmospheric gases of interest.

Periodic density modulation for quasi-phase-matching of optical frequency conversion is inefficient under shallow focusing and constant ambient pressure.

PubMed

Hadas, Itai; Bahabad, Alon

2016-09-01

The two main mechanisms of a periodic density modulation relevant to nonlinear optical conversion in a gas medium are spatial modulations of the index of refraction and of the number of emitters. For a one-dimensional model neglecting focusing and using a constant ambient pressure, it is shown theoretically and demonstrated numerically that the effects of these two mechanisms during frequency conversion cancel each other exactly. Under the considered conditions, this makes density modulation inefficient for quasi-phase-matching an optical frequency conversion process. This result is particularly relevant for high-order harmonic generation.

Earthtech, Dig-Texas and Upward Bound: Outreach to At-Risk Students with Interdisciplinary STEM Activities

NASA Astrophysics Data System (ADS)

Olgin, J. G.; Güereque, M.; Pennington, D. D.; Everett, A.; Dixon, J. G.; Reyes, A.; Houser, P. I. Q.; Baker, J. A.; Stocks, E.; Ellins, K.

2015-12-01

The Geological Sciences department at the University of Texas at El Paso (UTEP) hosted the EarthTech outreach program - a one-week intensive summer camp for low-income, at-risk high school students. The EarthTech program engaged students in STEM activities from geological and environmental sciences. Developed and led by university student-mentors with guidance from a supervising faculty member, the course engaged Upward Bound students with lectures, interactive projects, and excursions to local ecological preserves and geological sites around El Paso, Texas. Topics covered plant and animal distribution and diversity, water and soil dynamics, evolution and paleontology, geohazards, and planetary science. Field trips were combined with hands-on activities, including activities from DIG Texas teaching modules. The NSF-funded DIG Texas Instructional Blueprints project is organizing vetted, high quality online educational resources and learning activities into teaching modules. The modules follow a storyline and demonstrate congruency with the Next Generation Science Standards. Selected DIG Texas resources were included in the daily curriculum to complement the field trip and other hands-on activities. EarthTech students created ESRI Online GIS story maps in which they showed the locations of the field trips, incorporated photographs they had taken, and provided written reflections about their camp experiences. The DIG Texas project evaluation collected survey and interview data from the university student mentors throughout the week to ascertain the efficacy of the program. This poster presentation will include an overview of the program, including examples of work and evaluation results.

KENNEDY SPACE CENTER, FLA. - The JEM Pressurized Module is seen in the hold of the ship that carried it from Japan. The National Space Development Agency of Japan (NASDA) built the laboratory at the Tsukuba Space Center near Tokyo. The Pressurized Module is the first element of the JEM, Japan’s primary contribution to the space station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. The JEM also includes two logistics modules, an exposed pallet for space environment experiments and a robotic manipulator system that are still under construction in Japan. The various JEM components will be assembled in space over the course of three space shuttle missions.

NASA Image and Video Library

2003-05-30

KENNEDY SPACE CENTER, FLA. - The JEM Pressurized Module is seen in the hold of the ship that carried it from Japan. The National Space Development Agency of Japan (NASDA) built the laboratory at the Tsukuba Space Center near Tokyo. The Pressurized Module is the first element of the JEM, Japan’s primary contribution to the space station, to be delivered to KSC. It will enhance the unique research capabilities of the orbiting complex by providing an additional shirt-sleeve environment for astronauts to conduct science experiments. The JEM also includes two logistics modules, an exposed pallet for space environment experiments and a robotic manipulator system that are still under construction in Japan. The various JEM components will be assembled in space over the course of three space shuttle missions.

Health Instruction Packages: Consumer--Your Heart and Blood Pressure.

ERIC Educational Resources Information Center

Woods, James W.; And Others

Text, illustrations, and exercises are utilized in this set of learning modules to instruct the general public in the prevention and treatment of heart disease. The first module, by James W. Woods, presents a medical definition of high blood pressure, reviews its causes and effects, and discusses its treatment. A script to a slide version of this…

A Late Cambrian Carbon Isotope Excursion Recorded in Passive Margin Dolostones of the Central Appalachian Basin, USA.

NASA Astrophysics Data System (ADS)

Mackey, J. E.; Stewart, B. W.

2016-12-01

A Late Cambrian global positive carbon isotope excursion, known as the SPICE event [1,2] is linked to possible widespread ocean anoxia and enhanced carbon burial [3,4]. We report data from the central Appalachian Conasauga Group from the upper portion of the Middle Cambrian Maryville limestone, through the Late Cambrian Nolichucky shale and Maynardville limestone members. A geochemical, macro-, and micro-scale analyses of core material from southeastern Ohio was carried out to further constrain the timing of oceanic anoxia and trace element geochemistry relative to sediment fluxes occurring at the transition of the Middle to Late Cambrian. The section represents condensed, passive margin shale deposition and carbonate ramp development on the continental shelf of Laurentia. Carbonate sediments (primarily diagenetic dolomite) record a positive δ13C (relative to V-PDB) excursion starting in the upper Nolichucky shale member, reaching its peak (+4.0) in the overlying Maynardville limestone. At this location, there is an offset between the onlap Nolichucky shale deposition and start of the C isotope excursion; this was reported as well in a carbonate section further south of this location [2], on the other side of an extensional feature (Rome Trough) that formed a deep marine basin during Cambrian time. The condensed shale package and relatively low TOC content in our samples is likely due to the combination of a shallow, upslope basin location and isostatic influence on passive margin sedimentation. However, within the Rome Trough, the Nolichucky shale is rich in organic carbon and a recent target of hydrocarbon exploration. The data suggest a possible link between deposition of this shale and the global SPICE event. The robustness of the Late Cambrian δ13C excursion in diagenetically altered sediments and association with hydrocarbon bearing units indicates its utility as a stratigraphic indicator and as a target for exploration. Ongoing geochemical work will focus on trace element and isotopic signatures preserved in the carbonate portion of sediments spanning the C isotope excursion. Refs: [1] Saltzman et al., 1998, Geol. Soc. Am. Bull. 110, 285-297; [2] Glumac and Walker, 1998, J. Sed. Res. 68, 1212-1222; [3] Hurtgen et al., 2009, Earth Planet. Sci. Lett. 281, 288-297; [4] Gill et al., 2011, Nature 469, 80-83.

Subject-specific modeling of muscle force and knee contact in total knee arthroplasty.

PubMed

Navacchia, Alessandro; Rullkoetter, Paul J; Schütz, Pascal; List, Renate B; Fitzpatrick, Clare K; Shelburne, Kevin B

2016-09-01

Understanding the mechanical loading environment and resulting joint mechanics for activities of daily living in total knee arthroplasty is essential to continuous improvement in implant design. Although survivorship of these devices is good, a substantial number of patients report dissatisfaction with the outcome of their procedure. Knowledge of in vivo kinematics and joint loading will enable improvement in preclinical assessment and refinement of implant geometry. The purpose of this investigation was to describe the mechanics of total knee arthroplasty during a variety of activities of daily living (gait, walking down stairs, and chair rise/sit). Estimates of muscle forces, tibial contact load, location, and pressure distribution was performed through a combination of mobile fluoroscopy data collection, musculoskeletal modeling, and finite element simulation. For the activities evaluated, joint compressive load was greatest during walking down stairs; however, the highest contact pressure occurred during chair rise/sit. The joint contact moment in the frontal plane was mainly varus for gait and walking down stairs, while it was valgus during chair rise/sit. Excursion of the center of pressure on the tibial component was similar during each activity and between the medial and lateral sides. The main determinants of center of pressure location were internal-external rotation, joint load, and tibial insert conformity. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1576-1587, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Foot reflexology can increase vagal modulation, decrease sympathetic modulation, and lower blood pressure in healthy subjects and patients with coronary artery disease.

PubMed

Lu, Wan-An; Chen, Gau-Yang; Kuo, Cheng-Deng

2011-01-01

Complementary and alternative medicine (CAM) has long been used by people to postpone the aging process and to reverse disease progression. Reflexology is a CAM method that involves massage to reflex areas in the feet and hands. This study investigated the effect of foot reflexology (FR) on the autonomic nervous modulation in patients with coronary artery disease (CAD) by using heart rate variability analysis. Seventeen people with angiographically patent coronary arteries and 20 patients with CAD scheduled for coronary artery bypass graft surgery were recruited as the control and CAD groups, respectively. The normalized high-frequency power (nHFP) was used as the index of vagal modulation and the normalized very low-frequency power (nVLFP) as the index of vagal withdrawal and renin-angiotensin modulation. In both control and CAD groups, the nHFP was increased significantly whereas the nVLFP was decreased significantly 30 and 60 minutes after FR, as compared with those before FR. The systolic, diastolic, mean arterial, and pulse pressures were significantly decreased after FR in both groups of participants. In the CAD group, the percentage change in heart rate 30 and 60 minutes after FR was smaller than that in the control, and the percentage change in nVLFP 60 minutes after FR was smaller than that in the control. In conclusion, a higher vagal modulation, lower sympathetic modulation, and lower blood pressure can be observed following 60 minutes of FR in both controls and CAD patients. The magnitude of change in the autonomic nervous modulation in CAD patients was slightly smaller than that in the controls. FR may be used as an efficient adjunct to the therapeutic regimen to increase the vagal modulation and decrease blood pressure in both healthy people and CAD patients.

KSC-07pd2843

NASA Image and Video Library

2007-10-11

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility at NASA's Kennedy Space Center, members of the STS-123 crew learn more about the mission payload, the Kibo Experiment Logistics Module Pressurized Section. Crew members are Commander Dominic Gorie, Pilot Gregory Johnson and Mission Specialists Richard Linnehan, Takao Doi, Robert Behnken, Gerrett Reisman and Michael Foreman. Doi represents the Japan Aerospace Exploration Agency. Reisman will remain on the space station after the mission as a flight engineer for Expedition 16. STS-123 will carry and install one of the components of the Japanese Experiment Module, or JEM. Known as Kibo, the JEM comprises six components: two research facilities -- the Pressurized Module and Exposed Facility; a Logistics Module attached to each of them; a Remote Manipulator System; and an Inter-Orbit Communication System unit. The various components of JEM will be assembled in space over the course of three space shuttle missions. The first of those three missions, STS-123, will carry the Experiment Logistics Module Pressurized Section aboard the space shuttle Endeavour, targeted for launch in February 2008. Photo credit: NASA/Dimitrios Gerondidakis

Non-Gaussianity and Excursion Set Theory: Halo Bias

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

Adshead, Peter; Baxter, Eric J.; Dodelson, Scott

2012-09-01

We study the impact of primordial non-Gaussianity generated during inflation on the bias of halos using excursion set theory. We recapture the familiar result that the bias scales asmore » $$k^{-2}$$ on large scales for local type non-Gaussianity but explicitly identify the approximations that go into this conclusion and the corrections to it. We solve the more complicated problem of non-spherical halos, for which the collapse threshold is scale dependent.« less

Calcium isotope constraints on the end-Permian mass extinction

PubMed Central

Payne, Jonathan L.; Turchyn, Alexandra V.; Paytan, Adina; DePaolo, Donald J.; Lehrmann, Daniel J.; Yu, Meiyi; Wei, Jiayong

2010-01-01

The end-Permian mass extinction horizon is marked by an abrupt shift in style of carbonate sedimentation and a negative excursion in the carbon isotope (δ13C) composition of carbonate minerals. Several extinction scenarios consistent with these observations have been put forward. Secular variation in the calcium isotope (δ44/40Ca) composition of marine sediments provides a tool for distinguishing among these possibilities and thereby constraining the causes of mass extinction. Here we report δ44/40Ca across the Permian-Triassic boundary from marine limestone in south China. The δ44/40Ca exhibits a transient negative excursion of ∼0.3‰ over a few hundred thousand years or less, which we interpret to reflect a change in the global δ44/40Ca composition of seawater. CO2-driven ocean acidification best explains the coincidence of the δ44/40Ca excursion with negative excursions in the δ13C of carbonates and organic matter and the preferential extinction of heavily calcified marine animals. Calcium isotope constraints on carbon cycle calculations suggest that the average δ13C of CO2 released was heavier than -28‰ and more likely near -15‰; these values indicate a source containing substantial amounts of mantle- or carbonate-derived carbon. Collectively, the results point toward Siberian Trap volcanism as the trigger of mass extinction. PMID:20421502

Comparison of Dynamic Balance in Collegiate Field Hockey and Football Players Using Star Excursion Balance Test

PubMed Central

Bhat, Rashi; Moiz, Jamal Ali

2013-01-01

Purpose The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. Methods A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. Results There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Conclusion Field hockey players and football players did not differ in terms of dynamic balance. PMID:24427482

Entry Trajectory Issues for the Stardust Sample Return Capsule

NASA Technical Reports Server (NTRS)

Desai, Prasun N.; Mitcheltree, Robert A.; Cheatwood, F. McNeil

1999-01-01

The Stardust mission was successfully launched on February 7, 1999. It will be the first mission to return samples from a comet. The sample return capsule, which is passively controlled during the fastest Earth entry ever, will land by parachute in Utah. The present study describes the analysis of the entry, descent, and landing of the returning sample capsule utilizing the final, launch configuration capsule mass properties. The effects of two aerodynamic instabilities are revealed (one in the high altitude free molecular regime and the other in the transonic/subsonic flow regime). These instabilities could lead to unacceptably large excursions in the angle-of-attack near peak heating and main parachute deployment, respectively. To reduce the excursions resulting from the high altitude instability, the entry spin rate of the capsule is increased. To stabilize the excursions from the transonic/subsonic instability, a drogue chute with deployment triggered by a gravity-switch and timer is added prior to main parachute deployment. A Monte Carlo dispersion analysis of the modified entry (from which the impact of off-nominal conditions during the entry is ascertained) predicts that the capsule attitude excursions near peak heating and drogue chute deployment are within Stardust mission limits. Additionally, the size of the resulting 3-sigma landing ellipse is 60.8 km in downrange by 19.9 km in crossrange, which is within the Utah Test and Training Range boundaries.

Comparison of dynamic balance in collegiate field hockey and football players using star excursion balance test.

PubMed

Bhat, Rashi; Moiz, Jamal Ali

2013-09-01

The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Field hockey players and football players did not differ in terms of dynamic balance.

Doppler ultrasound surveillance in deep tunneling compressed-air work with Trimix breathing: bounce dive technique compared to saturation-excursion technique.

PubMed

Vellinga, T P van Rees; Sterk, W; de Boer, A G E M; van der Beek, A J; Verhoeven, A C; van Dijk, F J H

2008-01-01

The Western Scheldt Tunneling Project in The Netherlands provided a unique opportunity to evaluate two deep-diving techniques with Doppler ultrasound surveillance. Divers used the bounce diving techniques for repair and maintenance of the TBM. The tunnel boring machine jammed at its deepest depth. As a result the work time was not sufficient. The saturation diving technique was developed and permitted longer work time at great depth. Thirty-one divers were involved in this project. Twenty-three divers were examined using Doppler ultrasound. Data analysis addressed 52 exposures to Trimix at 4.6-4.8 bar gauge using the bounce technique and 354 exposures to Trimix at 4.0-6.9 bar gauge on saturation excursions. No decompression incidents occurred with either technique during the described phase of the project. Doppler ultrasound revealed that the bubble loads assessed in both techniques were generally low. We find out, that despite longer working hours, shorter decompression times and larger physical workloads, the saturation-excursion technique was associated with significant lower bubble grades than in the bounce technique using Doppler Ultrasound. We conclude that the saturation-excursion technique with Trimix is a good option for deep and long exposures in caisson work. The Doppler technique proved valuable, and it should be incorporated in future compressed-air work.

Masticatory motion after surgical or nonsurgical treatment for unilateral fractures of the mandibular condylar process.

PubMed

Throckmorton, Gaylord S; Ellis, Edward; Hayasaki, Haruaki

2004-02-01

We sought to compare mandibular motion during mastication in patients treated in either an open or a closed fashion for unilateral fractures of the mandibular condylar process. Eighty-one male patients with unilateral condylar process fractures were treated either with (n = 37) or without (n = 44) surgical reduction and rigid fixation of their condylar process fractures. At 6 weeks, 6 months, 1 year, and 2 years after treatment, the subjects' chewing cycles were recorded using a magnetic sensor array (Sirognathograph; Siemens Corp, Bensheim, Germany) while chewing Gummi-Bears (HARIBO, Bonn, Germany) unilaterally on the same side as the fracture and on the opposite side. The chewing cycles were analyzed using a custom computer program, and the duration, excursive ranges, and 3-dimensional cycle shape were compared between the 2 treatment groups at each time interval using multilevel linear modeling statistics. The 2 treatment groups did not differ significantly for any measure of cycle duration or any excursive range (except lateral excursions at 1 year post-treatment) at any of the time intervals. However, the 3-dimensional cycle shapes of the 2 groups did differ significantly at all time intervals. Surgical correction of unilateral condylar process fractures has relatively little effect on the more standard measures (duration and excursive ranges) of masticatory function. However, surgical correction better normalizes opening incisor pathways during mastication on the side opposite the fracture.

Accurate prediction of vaccine stability under real storage conditions and during temperature excursions.

PubMed

Clénet, Didier

2018-04-01

Due to their thermosensitivity, most vaccines must be kept refrigerated from production to use. To successfully carry out global immunization programs, ensuring the stability of vaccines is crucial. In this context, two important issues are critical, namely: (i) predicting vaccine stability and (ii) preventing product damage due to excessive temperature excursions outside of the recommended storage conditions (cold chain break). We applied a combination of advanced kinetics and statistical analyses on vaccine forced degradation data to accurately describe the loss of antigenicity for a multivalent freeze-dried inactivated virus vaccine containing three variants. The screening of large amounts of kinetic models combined with a statistical model selection approach resulted in the identification of two-step kinetic models. Predictions based on kinetic analysis and experimental stability data were in agreement, with approximately five percentage points difference from real values for long-term stability storage conditions, after excursions of temperature and during experimental shipments of freeze-dried products. Results showed that modeling a few months of forced degradation can be used to predict various time and temperature profiles endured by vaccines, i.e. long-term stability, short time excursions outside the labeled storage conditions or shipments at ambient temperature, with high accuracy. Pharmaceutical applications of the presented kinetics-based approach are discussed. Copyright © 2018 The Author. Published by Elsevier B.V. All rights reserved.

Status of Japanese Experiment Module (JEM) activities

NASA Technical Reports Server (NTRS)

1991-01-01

The current status of the JEM activities are presented in graphic form. The JEM spacecraft configuration is presented. The JEM configuration consist of the Pressurized Module, the Exposed Facility, the Experiment Logistics Module which consist of a pressurized section and an exposed section; and the Remote Manipulator System. The master schedule of the space station is given. Also the development tests of the structure and mechanism, the electrical power system, the data management system, the thermal control system, the environment control system, the experiment support system, and the remote manipulator system are listed.

KSC-07pd0893

NASA Image and Video Library

2007-04-17

KENNEDY SPACE CENTER, FLA. -- In the Space Station Processing Facility, astronaut Takao Doi (left) and Commander Dominic Gorie pose in front of the Experiment Logistics Module Pressurized Section for the Japanese Experiment Module, or JEM, that recently arrived at Kennedy. Doi and Gorie are crew members for mission STS-123 that will deliver the logistics module to the International Space Station. Earlier, NASA and Japanese Aerospace and Exploration Agency (JAXA) officials welcomed the arrival of the module. The new International Space Station component arrived at Kennedy March 12 to begin preparations for its future launch on mission STS-123. It will serve as an on-orbit storage area for materials, tools and supplies. It can hold up to eight experiment racks and will attach to the top of another larger pressurized module. Photo credit: NASA/George Shelton