Extreme Conditions Modeling Workshop Report

Energy Technology Data Exchange (ETDEWEB)

Coe, R. G.; Neary, V. S.; Lawson, M. J.; Yu, Y.; Weber, J.

2014-07-01

Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, NM on May 13th-14th, 2014. The objective of the workshop was to review the current state of knowledge on how to model WECs in extreme conditions (e.g. hurricanes and other large storms) and to suggest how U.S. Department of Energy (DOE) and national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry.

Extreme climatic events constrain space use and survival of a ground-nesting bird.

Science.gov (United States)

Tanner, Evan P; Elmore, R Dwayne; Fuhlendorf, Samuel D; Davis, Craig A; Dahlgren, David K; Orange, Jeremy P

2017-05-01

Two fundamental issues in ecology are understanding what influences the distribution and abundance of organisms through space and time. While it is well established that broad-scale patterns of abiotic and biotic conditions affect organisms' distributions and population fluctuations, discrete events may be important drivers of space use, survival, and persistence. These discrete extreme climatic events can constrain populations and space use at fine scales beyond that which is typically measured in ecological studies. Recently, a growing body of literature has identified thermal stress as a potential mechanism in determining space use and survival. We sought to determine how ambient temperature at fine temporal scales affected survival and space use for a ground-nesting quail species (Colinus virginianus; northern bobwhite). We modeled space use across an ambient temperature gradient (ranging from -20 to 38 °C) through a maxent algorithm. We also used Andersen-Gill proportional hazard models to assess the influence of ambient temperature-related variables on survival through time. Estimated available useable space ranged from 18.6% to 57.1% of the landscape depending on ambient temperature. The lowest and highest ambient temperature categories (35 °C, respectively) were associated with the least amount of estimated useable space (18.6% and 24.6%, respectively). Range overlap analysis indicated dissimilarity in areas where Colinus virginianus were restricted during times of thermal extremes (range overlap = 0.38). This suggests that habitat under a given condition is not necessarily a habitat under alternative conditions. Further, we found survival was most influenced by weekly minimum ambient temperatures. Our results demonstrate that ecological constraints can occur along a thermal gradient and that understanding the effects of these discrete events and how they change over time may be more important to conservation of organisms than are average and broad

Injuries in an Extreme Conditioning Program

OpenAIRE

Aune, Kyle T.; Powers, Joseph M.

2016-01-01

Background: Extreme conditioning programs (ECPs) are fitness training regimens relying on aerobic, plyometric, and resistance training exercises, often with high levels of intensity for a short duration of time. These programs have grown rapidly in popularity in recent years, but science describing the safety profile of these programs is lacking. Hypothesis: The rate of injury in the extreme conditioning program is greater than the injury rate of weightlifting and the majority of injuries occ...

In-situ transmission electron microscopy growth of nanoparticles under extreme conditions

International Nuclear Information System (INIS)

Luce, F. P.; Azevedo, G. de M.; Baptista, D. L.; Zawislak, F. C.; Oliviero, E.; Fichtner, P. F. P.

2016-01-01

The formation and time resolved behavior of individual Pb nanoparticles embedded in silica have been studied by in-situ transmission electron microscopy observations at high temperatures (400–1100 °C) and under 200 keV electron irradiation. It is shown that under such extreme conditions, nanoparticles can migrate at long distances presenting a Brownian-like behavior and eventually coalesce. The particle migration phenomenon is discussed considering the influence of the thermal energy and the electron irradiation effects on the atomic diffusion process which is shown to control particle migration. These results and comparison with ex-situ experiments tackle the stability and the microstructure evolution of nanoparticles systems under extreme conditions. It elucidates on the effects of energetic particle irradiation-annealing treatments either as a tool or as a detrimental issue that could hamper their long-term applications in radiation-harsh environments such as in space or nuclear sectors

Extreme Conditions Modeling Workshop Report

Energy Technology Data Exchange (ETDEWEB)

Coe, Ryan Geoffrey [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Neary, Vincent Sinclair [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Lawon, Michael J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Yu, Yi-Hsiang [National Renewable Energy Lab. (NREL), Golden, CO (United States); Weber, Jochem [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-07-01

Sandia National Laboratories (SNL) and the National Renewable Energy Laboratory (NREL) hosted the Wave Energy Converter (WEC) Extreme Conditions Modeling (ECM) Workshop in Albuquerque, New Mexico on May 13–14, 2014. The objective of the workshop was to review the current state of knowledge on how to numerically and experimentally model WECs in extreme conditions (e.g. large ocean storms) and to suggest how national laboratory resources could be used to improve ECM methods for the benefit of the wave energy industry. More than 30 U.S. and European WEC experts from industry, academia, and national research institutes attended the workshop, which consisted of presentations from W EC developers, invited keynote presentations from subject matter experts, breakout sessions, and a final plenary session .

Extremophiles survival to simulated space conditions: an astrobiology model study.

Science.gov (United States)

Mastascusa, V; Romano, I; Di Donato, P; Poli, A; Della Corte, V; Rotundi, A; Bussoletti, E; Quarto, M; Pugliese, M; Nicolaus, B

2014-09-01

In this work we investigated the ability of four extremophilic bacteria from Archaea and Bacteria domains to resist to space environment by exposing them to extreme conditions of temperature, UV radiation, desiccation coupled to low pressure generated in a Mars' conditions simulator. All the investigated extremophilic strains (namely Sulfolobus solfataricus, Haloterrigena hispanica, Thermotoga neapolitana and Geobacillus thermantarcticus) showed a good resistance to the simulation of the temperature variation in the space; on the other hand irradiation with UV at 254 nm affected only slightly the growth of H. hispanica, G. thermantarcticus and S. solfataricus; finally exposition to Mars simulated condition showed that H. hispanica and G. thermantarcticus were resistant to desiccation and low pressure.

Rational Calibration of Four IEC 61400-1 Extreme External Conditions

DEFF Research Database (Denmark)

Larsen, Gunner Chr.; Hansen, Kurt Schaldemose

2008-01-01

Based on a set of asymptotic statistical models on closed form this paper presents a rational and consistent calibration of four extreme external conditions defined in the International Electrotechnical Commission (IEC) 61400-1 standard: extreme operating gust, extreme wind shear, extreme coheren...... and proposed specifications of the magnitudes of the extreme external wind conditions are highlighted and discussed using an illustrative example based on two selected terrain types. Copyright © 2008 John Wiley & Sons, Ltd....... gust with direction change and extreme wind direction change. These four extreme external conditions are used in the definition of six of the IEC 61400-1 ultimate load cases. The statistical models are based on simple and easily accessible mean wind speed and turbulence characteristics...

Correlation dimension and phase space contraction via extreme value theory

Science.gov (United States)

Faranda, Davide; Vaienti, Sandro

2018-04-01

We show how to obtain theoretical and numerical estimates of correlation dimension and phase space contraction by using the extreme value theory. The maxima of suitable observables sampled along the trajectory of a chaotic dynamical system converge asymptotically to classical extreme value laws where: (i) the inverse of the scale parameter gives the correlation dimension and (ii) the extremal index is associated with the rate of phase space contraction for backward iteration, which in dimension 1 and 2, is closely related to the positive Lyapunov exponent and in higher dimensions is related to the metric entropy. We call it the Dynamical Extremal Index. Numerical estimates are straightforward to obtain as they imply just a simple fit to a univariate distribution. Numerical tests range from low dimensional maps, to generalized Henon maps and climate data. The estimates of the indicators are particularly robust even with relatively short time series.

Extreme boundary of space semi-additive functionals on finite set

Directory of Open Access Journals (Sweden)

Gayratbay F. Djabbarov

2016-03-01

Full Text Available The present paper is devoted to study of the extreme boundary of the convexcompact set of all semi-additive functionals on a finite-point compactum. We shall find some classes of extreme points of the space semi-additive functionals OS (n .

Response of Simple, Model Systems to Extreme Conditions

Energy Technology Data Exchange (ETDEWEB)

Ewing, Rodney C. [Univ. of Michigan, Ann Arbor, MI (United States); Lang, Maik [Univ. of Michigan, Ann Arbor, MI (United States)

2015-07-30

The focus of the research was on the application of high-pressure/high-temperature techniques, together with intense energetic ion beams, to the study of the behavior of simple oxide systems (e.g., SiO₂, GeO₂, CeO₂, TiO₂, HfO₂, SnO₂, ZnO and ZrO₂) under extreme conditions. These simple stoichiometries provide unique model systems for the analysis of structural responses to pressure up to and above 1 Mbar, temperatures of up to several thousands of kelvin, and the extreme energy density generated by energetic heavy ions (tens of keV/atom). The investigations included systematic studies of radiation- and pressure-induced amorphization of high P-T polymorphs. By studying the response of simple stoichiometries that have multiple structural “outcomes”, we have established the basic knowledge required for the prediction of the response of more complex structures to extreme conditions. We especially focused on the amorphous state and characterized the different non-crystalline structure-types that result from the interplay of radiation and pressure. For such experiments, we made use of recent technological developments, such as the perforated diamond-anvil cell and in situ investigation using synchrotron x-ray sources. We have been particularly interested in using extreme pressures to alter the electronic structure of a solid prior to irradiation. We expected that the effects of modified band structure would be evident in the track structure and morphology, information which is much needed to describe theoretically the fundamental physics of track-formation. Finally, we investigated the behavior of different simple-oxide, composite nanomaterials (e.g., uncoated nanoparticles vs. core/shell systems) under coupled, extreme conditions. This provided insight into surface and boundary effects on phase stability under extreme conditions.

Extreme conditions (p, T, H)

Energy Technology Data Exchange (ETDEWEB)

Mesot, J [Lab. for Neutron Scattering ETH Zurich, Zurich (Switzerland) and Paul Scherrer Institute, Villigen (Switzerland)

1996-11-01

The aim of this paper is to summarize the sample environment which will be accessible at the SINQ. In order to illustrate the type of experiments which will be feasible under extreme conditions of temperature, magnetic field and pressure at the SINQ a few selected examples are also given. (author) 7 figs., 14 refs.

Near-extreme system condition and near-extreme remaining useful time for a group of products

International Nuclear Information System (INIS)

Wang, Hai-Kun; Li, Yan-Feng; Huang, Hong-Zhong; Jin, Tongdan

2017-01-01

When a group of identical products is operating in field, the aggregation of failures is a catastrophe to engineers and customers who strive to develop reliable and safe products. In order to avoid a swarm of failures in a short time, it is essential to measure the degree of dispersion from different failure times in a group of products to the first failure time. This phenomenon is relevant to the crowding of system conditions near the worst one among a group of products. The group size in this paper represents a finite number of products, instead of infinite number or a single product. We evaluate the reliability of the product fleet from two aspects. First, we define near-extreme system condition and near-extreme failure time for offline solutions, which means no online observations. Second, we apply them to a continuous degradation system that breaks down when it reaches a soft failure threshold. By using particle filtering in the framework of prognostics and health management for a group of products, we aim to estimate near-extreme system condition and further predict the remaining useful life (RUL) using online solutions. Numerical examples are provided to demonstrate the effectiveness of the proposed method. - Highlights: • The aggregation of failures is measured for a group of identical products. • The crowding of failures is quantitated by the near-extreme evaluations. • Near-extreme system condition are given for offline solutions. • Near-extreme remaining useful time are provided for online solutions.

Simulation of the 23 July 2012 Extreme Space Weather Event: What if This Extremely Rare CME Was Earth Directed?

Science.gov (United States)

Ngwira, Chigomezyo M.; Pulkkinen, Antti; Mays, M. Leila; Kuznetsova, Maria M.; Galvin, A. B.; Simunac, Kristin; Baker, Daniel N.; Li, Xinlin; Zheng, Yihua; Glocer, Alex

2013-01-01

Extreme space weather events are known to cause adverse impacts on critical modern day technological infrastructure such as high-voltage electric power transmission grids. On 23 July 2012, NASA's Solar Terrestrial Relations Observatory-Ahead (STEREO-A) spacecraft observed in situ an extremely fast coronal mass ejection (CME) that traveled 0.96 astronomical units (approx. 1 AU) in about 19 h. Here we use the SpaceWeather Modeling Framework (SWMF) to perform a simulation of this rare CME.We consider STEREO-A in situ observations to represent the upstream L1 solar wind boundary conditions. The goal of this study is to examine what would have happened if this Rare-type CME was Earth-bound. Global SWMF-generated ground geomagnetic field perturbations are used to compute the simulated induced geoelectric field at specific ground-based active INTERMAGNET magnetometer sites. Simulation results show that while modeled global SYM-H index, a high-resolution equivalent of the Dst index, was comparable to previously observed severe geomagnetic storms such as the Halloween 2003 storm, the 23 July CME would have produced some of the largest geomagnetically induced electric fields, making it very geoeffective. These results have important practical applications for risk management of electrical power grids.

Optimizing grade-control drillhole spacing with conditional simulations

Directory of Open Access Journals (Sweden)

Adrian Martínez-Vargas

2017-01-01

Full Text Available This paper summarizes a method to determine the optimum spacing of grade-control drillholes drilled with reverse-circulation. The optimum drillhole spacing was defined as that one whose cost equals the cost of misclassifying ore and waste in selection mining units (SMU. The cost of misclassification of a given drillhole spacing is equal to the cost of processing waste misclassified as ore (Type I error plus the value of the ore misclassified as waste (Type II error. Type I and Type II errors were deduced by comparing true and estimated grades at SMUs, in relation to a cuttoff grade value and assuming free ore selection. True grades at SMUs and grades at drillhole samples were generated with conditional simulations. A set of estimated grades at SMU, one per each drillhole spacing, were generated with ordinary kriging. This method was used to determine the optimum drillhole spacing in a gold deposit. The results showed that the cost of misclassification is sensitive to extreme block values and tend to be overrepresented. Capping SMU’s lost values and implementing diggability constraints was recommended to improve calculations of total misclassification costs.

Microbial survival of space vacuum and extreme ultraviolet irradiation: strain isolation and analysis during a rocket flight.

Science.gov (United States)

Saffary, Roya; Nandakumar, Renu; Spencer, Dennis; Robb, Frank T; Davila, Joseph M; Swartz, Marvin; Ofman, Leon; Thomas, Roger J; DiRuggiero, Jocelyne

2002-09-24

We have recovered new isolates from hot springs, in Yellowstone National Park and the Kamchatka Peninsula, after gamma-irradiation and exposure to high vacuum (10(-6) Pa) of the water and sediment samples. The resistance to desiccation and ionizing radiation of one of the isolates, Bacillus sp. strain PS3D, was compared to that of the mesophilic bacterium, Deinococcus radiodurans, a species well known for its extraordinary resistance to desiccation and high doses of ionizing radiation. Survival of these two microorganisms was determined in real and simulated space conditions, including exposure to extreme UV radiation (10-100 nm) during a rocket flight. We found that up to 15 days of desiccation alone had little effect on the viability of either bacterium. In contrast, exposure to space vacuum ( approximately 10(-6) Pa) decreased cell survival by two and four orders of magnitude for Bacillus sp. strain PS3D and D. radiodurans, respectively. Simultaneous exposure to space vacuum and extreme UV radiation further decreased the survival of both organisms, compared to unirradiated controls. This is the first report on the isolated effect of extreme UV at 30 nm on cell survival. Extreme UV can only be transmitted through high vacuum, therefore its penetration into the cells may only be superficial, suggesting that in contrast to near UV, membrane proteins rather than DNA were damaged by the radiation.

Extreme meteorological conditions

International Nuclear Information System (INIS)

Altinger de Schwarzkopf, M.L.

1983-01-01

Different meteorological variables which may reach significant extreme values, such as the windspeed and, in particular, its occurrence through tornadoes and hurricanes that necesarily incide and wich must be taken into account at the time of nuclear power plants' installation, are analyzed. For this kind of study, it is necessary to determine the basic phenomenum of design. Two criteria are applied to define the basic values of design for extreme meteorological variables. The first one determines the expected extreme value: it is obtained from analyzing the recurence of the phenomenum in a convened period of time, wich may be generally of 50 years. The second one determines the extreme value of low probability, taking into account the nuclear power plant's operating life -f.ex. 25 years- and considering, during said lapse, the occurrence probabilities of extreme meteorological phenomena. The values may be determined either by the deterministic method, which is based on the acknowledgement of the fundamental physical characteristics of the phenomena or by the probabilistic method, that aims to the analysis of historical statistical data. Brief comments are made on the subject in relation to the Argentine Republic area. (R.J.S.) [es

Using stochastic space-time models to map extreme precipitation in southern Portugal

Directory of Open Access Journals (Sweden)

A. C. Costa

2008-07-01

Full Text Available The topographic characteristics and spatial climatic diversity are significant in the South of continental Portugal where the rainfall regime is typically Mediterranean. Direct sequential cosimulation is proposed for mapping an extreme precipitation index in southern Portugal using elevation as auxiliary information. The analysed index (R5D can be considered a flood indicator because it provides a measure of medium-term precipitation total. The methodology accounts for local data variability and incorporates space-time models that allow capturing long-term trends of extreme precipitation, and local changes in the relationship between elevation and extreme precipitation through time. Annual gridded datasets of the flood indicator are produced from 1940 to 1999 on 800 m×800 m grids by using the space-time relationship between elevation and the index. Uncertainty evaluations of the proposed scenarios are also produced for each year. The results indicate that the relationship between elevation and extreme precipitation varies locally and has decreased through time over the study region. In wetter years the flood indicator exhibits the highest values in mountainous regions of the South, while in drier years the spatial pattern of extreme precipitation has much less variability over the study region. The uncertainty of extreme precipitation estimates also varies in time and space, and in earlier decades is strongly dependent on the density of the monitoring stations network. The produced maps will be useful in regional and local studies related to climate change, desertification, land and water resources management, hydrological modelling, and flood mitigation planning.

Quantum universe on extremely small space-time scales

International Nuclear Information System (INIS)

Kuzmichev, V.E.; Kuzmichev, V.V.

2010-01-01

The semiclassical approach to the quantum geometrodynamical model is used for the description of the properties of the Universe on extremely small space-time scales. Under this approach, the matter in the Universe has two components of the quantum nature which behave as antigravitating fluids. The first component does not vanish in the limit h → 0 and can be associated with dark energy. The second component is described by an extremely rigid equation of state and goes to zero after the transition to large spacetime scales. On small space-time scales, this quantum correction turns out to be significant. It determines the geometry of the Universe near the initial cosmological singularity point. This geometry is conformal to a unit four-sphere embedded in a five-dimensional Euclidean flat space. During the consequent expansion of the Universe, when reaching the post-Planck era, the geometry of the Universe changes into that conformal to a unit four-hyperboloid in a five-dimensional Lorentzsignatured flat space. This agrees with the hypothesis about the possible change of geometry after the origin of the expanding Universe from the region near the initial singularity point. The origin of the Universe can be interpreted as a quantum transition of the system from a region in the phase space forbidden for the classical motion, but where a trajectory in imaginary time exists, into a region, where the equations of motion have the solution which describes the evolution of the Universe in real time. Near the boundary between two regions, from the side of real time, the Universe undergoes almost an exponential expansion which passes smoothly into the expansion under the action of radiation dominating over matter which is described by the standard cosmological model.

Halophilic archaea on Earth and in space: growth and survival under extreme conditions.

Science.gov (United States)

Oren, Aharon

2014-12-13

Salts are abundant on Mars, and any liquid water that is present or may have been present on the planet is expected to be hypersaline. Halophilic archaea (family Halobacteriaceae) are the microorganisms best adapted to life at extremes of salinity on Earth. This paper reviews the properties of the Halobacteriaceae that may make the group good candidates for life also on Mars. Many species resist high UV and gamma radiation levels; one species has survived exposure to vacuum and radiation during a space flight; and there is at least one psychrotolerant species. Halophilic archaea may survive for millions of years within brine inclusions in salt crystals. Many species have different modes of anaerobic metabolism, and some can use light as an energy source using the light-driven proton pump bacteriorhodopsin. They are also highly tolerant to perchlorate, recently shown to be present in Martian soils, and some species can even use perchlorate as an electron acceptor to support anaerobic growth. The presence of characteristic carotenoid pigments (α-bacterioruberin and derivatives) makes the Halobacteriaceae easy to identify by Raman spectroscopy. Thus, if present on Mars, such organisms may be detected by Raman instrumentation planned to explore Mars during the upcoming ExoMars mission. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Injuries in an Extreme Conditioning Program.

Science.gov (United States)

Aune, Kyle T; Powers, Joseph M

2016-10-19

Extreme conditioning programs (ECPs) are fitness training regimens relying on aerobic, plyometric, and resistance training exercises, often with high levels of intensity for a short duration of time. These programs have grown rapidly in popularity in recent years, but science describing the safety profile of these programs is lacking. The rate of injury in the extreme conditioning program is greater than the injury rate of weightlifting and the majority of injuries occur to the shoulder and back. Cross-sectional study. Level 4. This is a retrospective survey of injuries reported by athletes participating in an ECP. An injury survey was sent to 1100 members of Iron Tribe Fitness, a gym franchise with 5 locations across Birmingham, Alabama, that employs exercises consistent with an ECP in this study. An injury was defined as a physical condition resulting from ECP participation that caused the athlete to either seek medical treatment, take time off from exercising, or make modifications to his or her technique to continue. A total of 247 athletes (22%) completed the survey. The majority (57%) of athletes were male (n = 139), and 94% of athletes were white (n = 227). The mean age of athletes was 38.9 years (±8.9 years). Athletes reported participation in the ECP for, on average, 3.6 hours per week (± 1.2 hours). Eighty-five athletes (34%) reported that they had sustained an injury while participating in the ECP. A total of 132 injuries were recorded, yielding an estimated incidence of 2.71 per 1000 hours. The shoulder or upper arm was the most commonly injured body site, accounting for 38 injuries (15% of athletes). Athletes with a previous shoulder injury were 8.1 times as likely to injure their shoulder in the ECP compared with athletes with healthy shoulders. The trunk, back, head, or neck (n = 29, 12%) and the leg or knee (n = 29, 12%) were the second most commonly injured sites. The injury incidence rate among athletes with study estimates the incidence of

Electro-Mechanical Systems for Extreme Space Environments

Science.gov (United States)

Mojarradi, Mohammad M.; Tyler, Tony R.; Abel, Phillip B.; Levanas, Greg

2011-01-01

Exploration beyond low earth orbit presents challenges for hardware that must operate in extreme environments. The current state of the art is to isolate and provide heating for sensitive hardware in order to survive. However, this protection results in penalties of weight and power for the spacecraft. This is particularly true for electro-mechanical based technology such as electronics, actuators and sensors. Especially when considering distributed electronics, many electro-mechanical systems need to be located in appendage type locations, making it much harder to protect from the extreme environments. The purpose of this paper to describe the advances made in the area of developing electro-mechanical technology to survive these environments with minimal protection. The Jet Propulsion Lab (JPL), the Glenn Research Center (GRC), the Langley Research Center (LaRC), and Aeroflex, Inc. over the last few years have worked to develop and test electro-mechanical hardware that will meet the stringent environmental demands of the moon, and which can also be leveraged for other challenging space exploration missions. Prototype actuators and electronics have been built and tested. Brushless DC actuators designed by Aeroflex, Inc have been tested with interface temperatures as low as 14 degrees Kelvin. Testing of the Aeroflex design has shown that a brushless DC motor with a single stage planetary gearbox can operate in low temperature environments for at least 120 million cycles (measured at motor) if long life is considered as part of the design. A motor control distributed electronics concept developed by JPL was built and operated at temperatures as low as -160 C, with many components still operational down to -245 C. Testing identified the components not capable of meeting the low temperature goal of -230 C. This distributed controller is universal in design with the ability to control different types of motors and read many different types of sensors. The controller

Application of Electro Chemical Machining for materials used in extreme conditions

Science.gov (United States)

Pandilov, Z.

2018-03-01

Electro-Chemical Machining (ECM) is the generic term for a variety of electrochemical processes. ECM is used to machine work pieces from metal and metal alloys irrespective of their hardness, strength or thermal properties, through the anodic dissolution, in aerospace, automotive, construction, medical equipment, micro-systems and power supply industries. The Electro Chemical Machining is extremely suitable for machining of materials used in extreme conditions. General overview of the Electro-Chemical Machining and its application for different materials used in extreme conditions is presented.

Matter Under Extreme Conditions: The Early Years

Science.gov (United States)

Keeler, R. Norris; Gibson, Carl H.

2012-03-01

Extreme conditions in natural flows are examined, starting with a turbulent big bang. A hydro-gravitational-dynamics cosmology model is adopted. Planck-Kerr turbulence instability causes Planck-particle turbulent combustion. Inertial-vortex forces induce a non-turbulent ki- netic energy cascade to Planck-Kolmogorov scales where vorticity is produced, overcoming 10113 Pa Planck-Fortov pressures. The spinning, expanding fireball has a slight deficit of Planck antiparticles. Space and mass-energy powered by gluon viscous stresses expand exponentially at speeds >1025 c. Turbulent temperature and spin fluctuations fossilize at scales larger than ct, where c is light speed and t is time. Because "dark-energy" antigravity forces vanish when infla- tion ceases, and because turbulence produces entropy, the universe is closed and will collapse and rebound. Density and spin fossils of big bang turbulent mixing trigger structure formation in the plasma epoch. Fragmenting protosuperclustervoids and protoclustervoids produce weak tur- bulence until the plasma-gas transition give chains of protogalaxies with the morphology of tur- bulence. Chain galaxy clusters observed at large redshifts ~8.6 support this interpretation. Pro- togalaxies fragment into clumps, each with a trillion Earth-mass H-He gas planets. These make stars, supernovae, the first chemicals, the first oceans and the first life soon after the cosmologi- cal event.

Biological effects of extreme environmental conditions. [considering limits of biosphere

Science.gov (United States)

Imshenetskiy, A. A.

1975-01-01

Actions of extreme physical and chemical space factors on microorganisms and plants are elaborated in order to establish limits for the biosphere. Considered are effects of low and high temperatures; ionizing and ultraviolet radiation; various gases; and effects of vibration, desiccation and acceleration.

Injuries in an Extreme Conditioning Program

Science.gov (United States)

Aune, Kyle T.; Powers, Joseph M.

2016-01-01

Background: Extreme conditioning programs (ECPs) are fitness training regimens relying on aerobic, plyometric, and resistance training exercises, often with high levels of intensity for a short duration of time. These programs have grown rapidly in popularity in recent years, but science describing the safety profile of these programs is lacking. Hypothesis: The rate of injury in the extreme conditioning program is greater than the injury rate of weightlifting and the majority of injuries occur to the shoulder and back. Study Design: Cross-sectional study. Level of Evidence: Level 4. Methods: This is a retrospective survey of injuries reported by athletes participating in an ECP. An injury survey was sent to 1100 members of Iron Tribe Fitness, a gym franchise with 5 locations across Birmingham, Alabama, that employs exercises consistent with an ECP in this study. An injury was defined as a physical condition resulting from ECP participation that caused the athlete to either seek medical treatment, take time off from exercising, or make modifications to his or her technique to continue. Results: A total of 247 athletes (22%) completed the survey. The majority (57%) of athletes were male (n = 139), and 94% of athletes were white (n = 227). The mean age of athletes was 38.9 years (±8.9 years). Athletes reported participation in the ECP for, on average, 3.6 hours per week (± 1.2 hours). Eighty-five athletes (34%) reported that they had sustained an injury while participating in the ECP. A total of 132 injuries were recorded, yielding an estimated incidence of 2.71 per 1000 hours. The shoulder or upper arm was the most commonly injured body site, accounting for 38 injuries (15% of athletes). Athletes with a previous shoulder injury were 8.1 times as likely to injure their shoulder in the ECP compared with athletes with healthy shoulders. The trunk, back, head, or neck (n = 29, 12%) and the leg or knee (n = 29, 12%) were the second most commonly injured sites. The

QCD under extreme conditions: an informal discussion

CERN Document Server

Fraga, E.S.

2015-05-22

We present an informal discussion of some aspects of strong interactions un- der extreme conditions of temperature and density at an elementary level. This summarizes lectures delivered at the 2013 and 2015 CERN – Latin-American Schools of High-Energy Physics and is aimed at students working in experi- mental high-energy physics.

Physics of condensed matter at extreme conditions

International Nuclear Information System (INIS)

Ross, M.

1988-01-01

The study of matter under extreme conditions is a highly interdisciplinary subject with broad applications to materials science, geophysics and astrophysics. High-pressure properties are studied in the laboratory using static and dynamic techniques. The two differ drastically in the methods of generating and measuring pressure and in the fundamentally different nature of the final compressed state. This article covers a very broad range of conditions, intended to present an overview of important recent developments and to emphasize the behavior of materials and the kinds of properties now being studied

Condensed Matter NMR under Extreme Conditions: Challenges and Opportunities

Science.gov (United States)

Reyes, Arneil

2006-11-01

Advances in resistive magnet and power supply technology have made available extremely high magnetic fields suitable for condensed matter broadline NMR experiments. This capability expands the available phase space for investigating a wide variety of materials using magnetic resonance; utilizing the strength of the field to expose or induce new physical phenomena resulting in better understanding of the physics. Continuous fields up to 45T in NHMFL Hybrid magnet have brought new challenges in designing NMR instrumentation. Field strengths and sample space limitations put constraints on RF pulse power, tuning range, bandwidth, and temperature control. The inclusion of other capabilities, including high pressure, optics, and sample rotation requires intricate probe design and construction, while extremely low milliKelvin temperatures are desired in order to explore energy scales where thermal fluctuations are suppressed. Optimization of these devices has been of paramount consideration in NHMFL Condensed Matter NMR user program. Science achieved at high fields, the new initiatives to develop resistively-detected NMR in 2D electron gas and similar systems, and the current new generation Series-Connected Hybrid magnets for NMR work will be discussed. The NHMFL is supported by the National Science Foundation and the State of Florida.

Ultrasonic Technique for Density Measurement of Liquids in Extreme Conditions

Science.gov (United States)

Kazys, Rymantas; Sliteris, Reimondas; Rekuviene, Regina; Zukauskas, Egidijus; Mazeika, Liudas

2015-01-01

An ultrasonic technique, invariant to temperature changes, for a density measurement of different liquids under in situ extreme conditions is presented. The influence of geometry and material parameters of the measurement system (transducer, waveguide, matching layer) on measurement accuracy and reliability is analyzed theoretically along with experimental results. The proposed method is based on measurement of the amplitude of the ultrasonic wave, reflected from the interface of the solid/liquid medium under investigation. In order to enhance sensitivity, the use of a quarter wavelength acoustic matching layer is proposed. Therefore, the sensitivity of the measurement system increases significantly. Density measurements quite often must be performed in extreme conditions at high temperature (up to 220 °C) and high pressure. In this case, metal waveguides between piezoelectric transducer and the measured liquid are used in order to protect the conventional transducer from the influence of high temperature and to avoid depolarization. The presented ultrasonic density measurement technique is suitable for density measurement in different materials, including liquids and polymer melts in extreme conditions. A new calibration algorithm was proposed. The metrological evaluation of the measurement method was performed. The expanded measurement uncertainty Uρ = 7.4 × 10−3 g/cm3 (1%). PMID:26262619

Ultrasonic Technique for Density Measurement of Liquids in Extreme Conditions.

Science.gov (United States)

Kazys, Rymantas; Sliteris, Reimondas; Rekuviene, Regina; Zukauskas, Egidijus; Mazeika, Liudas

2015-08-07

An ultrasonic technique, invariant to temperature changes, for a density measurement of different liquids under in situ extreme conditions is presented. The influence of geometry and material parameters of the measurement system (transducer, waveguide, matching layer) on measurement accuracy and reliability is analyzed theoretically along with experimental results. The proposed method is based on measurement of the amplitude of the ultrasonic wave, reflected from the interface of the solid/liquid medium under investigation. In order to enhance sensitivity, the use of a quarter wavelength acoustic matching layer is proposed. Therefore, the sensitivity of the measurement system increases significantly. Density measurements quite often must be performed in extreme conditions at high temperature (up to 220 °C) and high pressure. In this case, metal waveguides between piezoelectric transducer and the measured liquid are used in order to protect the conventional transducer from the influence of high temperature and to avoid depolarization. The presented ultrasonic density measurement technique is suitable for density measurement in different materials, including liquids and polymer melts in extreme conditions. A new calibration algorithm was proposed. The metrological evaluation of the measurement method was performed. The expanded measurement uncertainty Uρ = 7.4 × 10(-3) g/cm(3) (1%).

Ultrasonic Technique for Density Measurement of Liquids in Extreme Conditions

Directory of Open Access Journals (Sweden)

Rymantas Kazys

2015-08-01

Full Text Available An ultrasonic technique, invariant to temperature changes, for a density measurement of different liquids under in situ extreme conditions is presented. The influence of geometry and material parameters of the measurement system (transducer, waveguide, matching layer on measurement accuracy and reliability is analyzed theoretically along with experimental results. The proposed method is based on measurement of the amplitude of the ultrasonic wave, reflected from the interface of the solid/liquid medium under investigation. In order to enhance sensitivity, the use of a quarter wavelength acoustic matching layer is proposed. Therefore, the sensitivity of the measurement system increases significantly. Density measurements quite often must be performed in extreme conditions at high temperature (up to 220 °C and high pressure. In this case, metal waveguides between piezoelectric transducer and the measured liquid are used in order to protect the conventional transducer from the influence of high temperature and to avoid depolarization. The presented ultrasonic density measurement technique is suitable for density measurement in different materials, including liquids and polymer melts in extreme conditions. A new calibration algorithm was proposed. The metrological evaluation of the measurement method was performed. The expanded measurement uncertainty Uρ = 7.4 × 10−3 g/cm3 (1%.

What are extreme environmental conditions and how do organisms cope with them?

Directory of Open Access Journals (Sweden)

John C. WINGFIELD, J. Patrick KELLEY, Frédéric ANGELIER

2011-06-01

Full Text Available Severe environmental conditions affect organisms in two major ways. The environment may be predictably severe such as in deserts, polar and alpine regions, or individuals may be exposed to temporarily extreme conditions through weather, presence of predators, lack of food, social status etc. Existence in an extreme environment may be possible, but then to breed or molt in addition can present major bottlenecks that have resulted in the evolution of hormone-behavior adaptations to cope with unpredictable events. Examples of hormone-behavior adaptations in extreme conditions include attenuated testosterone secretion because territoriality and excess courtship may be too costly when there is one opportunity to reproduce. The individual may even become insensitive to testosterone when target areas of the brain regulating reproductive behavior no longer respond to the hormone. A second example is reduced sensitivity to glucocorticoids following acute stress during the breeding season or molt that allows successful reproduction and/or a vital renewal of the integument to endure extreme conditions during the rest of the year. Reduced sensitivity could involve: (a modulated response of the hypothalamo-pituitary-adrenal axis, (b reduced sensitivity to high glucocorticoid levels, or (c a combination of (a and (b. Moreover, corticosteroid binding proteins (CBP buffer responses to stress by reducing the movement of glucocorticoids into target cells. Finally, intracellular enzymes (11b-hydroxysteroid dehydrogenase and variants can deactivate glucocorticoids entering cells thus reducing interaction with receptors. These mechanisms have important implications for climate change and increasing extremes of weather [Current Zoology 57 (3: 363–374, 2011].

Correlation between Space and Atmospheric March 2012 Extreme Events

Science.gov (United States)

Anagnostopoulos, Georgios C.

2015-04-01

Previous studies have provided statistical evidence of a solar cycle correlation between space weather and meteorological phenomena. In this study we present a case study, the March 2012 events, with a strong evidence of such a correlation between space and atmospheric extreme events. March 2012 phenomena, beside a great CME (March 7) and a following superstorm, has been most known in the scientific community as well as in the public from the historic heat wave in USA. This event was not anticipated by solely atmospheric models (called a "black swan event":http://www.esrl.noaa.gov/psd/csi/events/2012/marchheatwave/anticipation.html). Furthermore, various extreme phenomena as high temperatures, intense rainfalls and ice extent at middle and high latitudes followed the March 7, 2012 CME all over the globe (USA, Europe, Australia, Antartic), while unusual measurements of various atmospheric and ionospheric quantities were observed by a series of satellites (TIMED, MODIS, NOAA etc.) In this study we concentrate to (a) the unusual high maximum of temperature in north-east USA (highest values since 1910) and (b) intense winds, rainfalls and fluctuating (>1500 V/m) geolectric fields in South East Europe (Greece). These events were observed almost simultaneously with geomagnetic storms and unusual radiation belt electron precipitation (RBEP) events on days 6-9, 10-12 and 26-28.3.2012 (two CMEs and one CIR). The most striking result is the time coincidence of variations of several space and meteorological measurements, which, for instance, most probably suggests a direct influence of the RBEP on the intense rainfalls observed in Greece. It is also possible that the RBEP at polar latitudes was responsible for the positive North Atlantic Oscillation effect evaluated at those times, which contributed to the global middle and high latitude weather variations. Our study provides an example of possible space weather utility to the atmospheric models, and, therefore, to the

Taking Extreme Space Weather to the Milky Way

Science.gov (United States)

Pesnell, W. Dean

2014-06-01

Extreme Space Weather events are large solar flares or geomagnetic storms, which can cause economic damage that cost billions of dollars to recover from. We have few examples of such events; only the Carrington Event (the solar superstorm) has superlatives in three categories: size of solar flare, drop in Dst, and amplitude of aa. Kepler observations show that stars similar to the Sun can have flares releasing thousands of times more energy than an X-class flare. These flares would strongly affect the atmosphere surrounding a planet orbiting such a star. Particle and magnetic field outflows from these stars could also be present. We are investigating the level of solar activity that is necessary to strongly affect the atmosphere of terrestrial planets. We assume that a habitable planet requires an atmosphere with a temperature and composition that is stable in time. Can we then extrapolate results from our solar system to determine a space of stellar parameters in which habitable planets can exist?

Decision Making and Risk Evaluation Frameworks for Extreme Space Weather Events

Science.gov (United States)

Uritskaya, O.; Robinson, R. M.; Pulkkinen, A. A.

2017-12-01

Extreme Space Weather events (ESWE) are in the spotlight nowadays because they can produce a significant impact not only due to their intensity and broad geographical scope, but also because of the widespread levels and the multiple sectors of the economy that could be involved. In the task of evaluation of the ESWE consequences, the most problematic and vulnerable aspect is the determination and calculation of the probability of statistically infrequent events and the subsequent assessment of the economic risks. In this work, we conduct a detailed analysis of the available frameworks of the general Decision-Making Theory in the presence of uncertainty, in the context of their applicability for the numerical estimation of the risks and losses associated with ESWE. The results of our study demonstrate that, unlike the Multiple-criteria decision analysis or Minimax approach to modeling of the possible scenarios for the ESWE effects, which prevail in the literature, the most suitable concept is the Games Against Nature (GAN). It enables an evaluation of every economically relevant aspect of space weather conditions and obtain more detailed results. Choosing the appropriate methods for solving GAN models, i.e. determining the most optimal strategy with a given level of uncertainty, requires estimating the conditional probabilities of Space Weather events for each outcome of possible scenarios of this natural disaster. Due to the specifics of complex natural and economic systems, with which we are dealing in this case, this problem remains unsolved, mainly because of inevitable loss of information at every stage of the decision-making process. The analysis is illustrated by deregulated electricity markets of the USA and Canada, whose power grid systems are known to be perceptive to ESWE. The GAN model is more appropriate in identifying potential risks in economic systems. The proposed approach, when applied to the existing database of Space Weather observations and

User-Defined Meteorological (MET) Profiles from Climatological and Extreme Condition Data

Science.gov (United States)

2018-04-01

ARL-TN-0876 ● MAR 2018 US Army Research Laboratory User-Defined Meteorological (MET) Profiles from Climatological and Extreme...needed. Do not return it to the originator. ARL-TN-0876 ● MAR 2018 US Army Research Laboratory User-Defined Meteorological (MET...User-Defined Meteorological (MET) Profiles from Climatological and Extreme Condition Data 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

The Mackey convergence condition for spaces with webs

Directory of Open Access Journals (Sweden)

Thomas E. Gilsdorf

1988-01-01

Full Text Available If each sequence converging to 0 in a locally convex space is also Mackey convergent to 0, that space is said to satisfy the Mackey convergence condition. The problem of characterizing those locally convex spaces with this property is still open. In this paper, spaces with compatible webs are used to construct both a necessary and a sufficient condition for a locally convex space to satisfy the Mackey convergence condition.

Extremal rotating black holes in the near-horizon limit: Phase space and symmetry algebra

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G. Compère

2015-10-01

Full Text Available We construct the NHEG phase space, the classical phase space of Near-Horizon Extremal Geometries with fixed angular momenta and entropy, and with the largest symmetry algebra. We focus on vacuum solutions to d dimensional Einstein gravity. Each element in the phase space is a geometry with SL(2,R×U(1d−3 isometries which has vanishing SL(2,R and constant U(1 charges. We construct an on-shell vanishing symplectic structure, which leads to an infinite set of symplectic symmetries. In four spacetime dimensions, the phase space is unique and the symmetry algebra consists of the familiar Virasoro algebra, while in d>4 dimensions the symmetry algebra, the NHEG algebra, contains infinitely many Virasoro subalgebras. The nontrivial central term of the algebra is proportional to the black hole entropy. The conserved charges are given by the Fourier decomposition of a Liouville-type stress-tensor which depends upon a single periodic function of d−3 angular variables associated with the U(1 isometries. This phase space and in particular its symmetries can serve as a basis for a semiclassical description of extremal rotating black hole microstates.

Proceedings of the second symposium on science of hadrons under extreme conditions

International Nuclear Information System (INIS)

Chiba, Satoshi

2000-08-01

The second symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on January 24 to 26, 2000. The symposium was devoted for discussions and presentations of research results in wide variety of fields such as nuclear matter, high-energy nuclear reactions, quantum chromodynamics, supernovae and nucleosynthesis to understand various aspects of hadrons under extreme conditions. The 26 of the presented papers are indexed individually. (J.P.N.)

Behavior under Extreme Conditions: The Titanic Disaster

OpenAIRE

Bruno S. Frey; David A. Savage; Benno Torgler

2011-01-01

During the night of April 14, 1912, the RMS Titanic collided with an iceberg on her maiden voyage. Two hours and 40 minutes later she sank, resulting in the loss of 1,501 lives—more than two-thirds of her 2,207 passengers and crew. This remains one of the deadliest peacetime maritime disasters in history and by far the most famous. For social scientists, evidence about how people behaved as the Titanic sunk offers a quasi-natural field experiment to explore behavior under extreme conditions o...

Modular SiGe 130 nm Cell Library for Extreme Environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NASA space missions utilizing application-specific integrated circuits (ASICs) under extreme conditions have a critical need for high performance analog cell...

Distribution patterns of terricolous and saxicolous lichens in extreme desert conditions

Science.gov (United States)

Temina, M.

2012-04-01

The investigation of biodiversity in stressful habitats is of great interest because it elucidates relationships between organisms and their environment, as well as revealing the mechanisms of their survival and adaptation to extreme conditions. Deserts represent such stressful habitats where harsh climate and limited resources greatly influence the formation of biota. In order to understand the link between microscale environmental variability in extreme arid conditions and lichen biodiversity patterns, we conducted the present study. For this purpose, the structure and distribution of lichen communities on soil and cobbles at six stations at "Evolution Canyon" III (EC III), Nahal Shaharut, in the extreme southern Negev, Israel, were examined. The opposite slopes of the canyon represented specific ecological niches characterized by sharply different microclimatic conditions. The following characteristics of lichen communities were studied: species richness, systematic diversity, biogeographical elements, frequencies and distribution of species, their morphological and anatomical characteristics, reproductive strategy, and ecological peculiarities. In the research site three environmental variables were evaluated: soil moisture, and temperatures of soil and cobbles. The Canonical Correspondence Analysis was used to study the influence of these ecological variables on the distribution of lichen species. The lichen diversity of EC III was very poor and comprised 12 species (3 cyanoliches on soil vs. 9 phycolichens on cobbles). Most of them belong to a specific group of arid endemic elements, adapted to survive in extreme arid conditions in the deserts of the Levant. The harsh desert conditions of the canyon negatively influence the reproductive ability of lichens. This influence is expressed in the decreased sizes of fruit bodies in some species, and the frequent occurrence of sterile specimens among lichens found in the canyon. A comparative analysis of structure

Extreme covariant quantum observables in the case of an Abelian symmetry group and a transitive value space

International Nuclear Information System (INIS)

Haapasalo, Erkka Theodor; Pellonpaeae, Juha-Pekka

2011-01-01

We represent quantum observables as normalized positive operator valued measures and consider convex sets of observables which are covariant with respect to a unitary representation of a locally compact Abelian symmetry group G. The value space of such observables is a transitive G-space. We characterize the extreme points of covariant observables and also determine the covariant extreme points of the larger set of all quantum observables. The results are applied to position, position difference, and time observables.

Extreme Temperature Performance of Automotive-Grade Small Signal Bipolar Junction Transistors

Science.gov (United States)

Boomer, Kristen; Damron, Benny; Gray, Josh; Hammoud, Ahmad

2018-01-01

Electronics designed for space exploration missions must display efficient and reliable operation under extreme temperature conditions. For example, lunar outposts, Mars rovers and landers, James Webb Space Telescope, Europa orbiter, and deep space probes represent examples of missions where extreme temperatures and thermal cycling are encountered. Switching transistors, small signal as well as power level devices, are widely used in electronic controllers, data instrumentation, and power management and distribution systems. Little is known, however, about their performance in extreme temperature environments beyond their specified operating range; in particular under cryogenic conditions. This report summarizes preliminary results obtained on the evaluation of commercial-off-the-shelf (COTS) automotive-grade NPN small signal transistors over a wide temperature range and thermal cycling. The investigations were carried out to establish a baseline on functionality of these transistors and to determine suitability for use outside their recommended temperature limits.

Tolerances of microorganisms to extreme environmental conditions

International Nuclear Information System (INIS)

West, J.M.; Arme, S.C.

1985-03-01

Microbial isolates from sites relevant to the disposal of radioactive wastes have been subjected to extreme environmental conditions in order to ascertain their tolerance ability. Two groups were chosen, sulphate reducing bacteria and sulphur oxidising bacteria, because of their potential effects on waste containment. They have been subjected to high temperatures, pressures and radiation (delta-emissions) in optimal media conditions and their ability to tolerate the conditions has been ascertained by epifluorescence microscopy and adenosine tri-phosphate (ATP) analysis followed by 'culture-on' to assess post experimental viability. Results indicate that the sulphate reducers in general, are more tolerant to these conditions than the sulphur oxidisers, some proving to be thermophilic. The sulphate reducer showed increased growth rates, as determined by population numbers, at 50 0 C and survived at 80 0 C, 4,500 psig (310 bar) with no subsequent loss in viability. Gamma irradiation of this group and an isolate of 10 5 rad over 4 hours had no effect on population numbers or viability. Such resistances are not apparent with the sulphur oxidisers whose numbers decreased with increasing radiation dose and are destroyed with pressure. (author)

Shocking matter to extreme conditions

International Nuclear Information System (INIS)

Gupta, Y.M.; Sharma, S.M.

1997-01-01

A good understanding of the thermodynamic response of matter at high compression and high energy densities is important to several areas of physics. Shock-wave experiments are uniquely suited for obtaining data at extreme conditions, and a shock-compressed matter can be viewed as a condensed system with or without dissociation or as a strongly coupled plasma. This article reviews work by Da Silva et al. in which irradiances ranging from 5x10 superscript 12 to 2x10 superscript 14 W/cm 2 were used to generate 8- to 10-ns square pulses in liquid deuterium. The authors demonstrated negligible pre-heating of the sample, steady propagation of the shock wave, and direct determination of the shock wave velocity along with particle velocity and density in the shocked state. Da Silva et al. results are compared with models and other experimental information, and the usefulness of the data in other areas is assessed. 11 refs., 1 fig

Space charge dosimeters for extremely low power measurements of radiation in shipping containers

Science.gov (United States)

Britton, Jr; Charles, L [Alcoa, TN; Buckner, Mark A [Oak Ridge, TN; Hanson, Gregory R [Clinton, TN; Bryan, William L [Knoxville, TN

2011-04-26

Methods and apparatus are described for space charge dosimeters for extremely low power measurements of radiation in shipping containers. A method includes in situ polling a suite of passive integrating ionizing radiation sensors including reading-out dosimetric data from a first passive integrating ionizing radiation sensor and a second passive integrating ionizing radiation sensor, where the first passive integrating ionizing radiation sensor and the second passive integrating ionizing radiation sensor remain situated where the dosimetric data was integrated while reading-out. Another method includes arranging a plurality of ionizing radiation sensors in a spatially dispersed array; determining a relative position of each of the plurality of ionizing radiation sensors to define a volume of interest; collecting ionizing radiation data from at least a subset of the plurality of ionizing radiation sensors; and triggering an alarm condition when a dose level of an ionizing radiation source is calculated to exceed a threshold.

Mechanical characterization of alloys in extreme conditions of high strain rates and high temperature

Science.gov (United States)

Cadoni, Ezio

2018-03-01

The aim of this paper is the description of the mechanical characterization of alloys under extreme conditions of temperature and loading. In fact, in the frame of the Cost Action CA15102 “Solutions for Critical Raw Materials Under Extreme Conditions (CRM-EXTREME)” this aspect is crucial and many industrial applications have to consider the dynamic response of materials. Indeed, for a reduction and substitution of CRMs in alloys is necessary to design the materials and understand if the new materials behave better or if the substitution or reduction badly affect their performance. For this reason, a deep knowledge of the mechanical behaviour at high strain-rates of considered materials is required. In general, machinery manufacturing industry or transport industry as well as energy industry have important dynamic phenomena that are simultaneously affected by extended strain, high strain-rate, damage and pressure, as well as conspicuous temperature gradients. The experimental results in extreme conditions of high strain rate and high temperature of an austenitic stainless steel as well as a high-chromium tempered martensitic reduced activation steel Eurofer97 are presented.

Extreme conditions over Europe and North America: role of the Atlantic Multidecadal Variability

Science.gov (United States)

Ruprich-Robert, Yohan; Msadek, Rym; Delworth, Tom

2016-04-01

The Atlantic Multidecadal Variability (AMV) is the result and possibly the source of marked modulations of the climate over many areas of the globe. For instance, the relatively warm and dry climate of North America throughout the 30-yr interval of 1931-60, during which the Dust Bowl and the 1950's drought occurred, has been linked to the concomitant warm phase of the AMV. During this period relative warm and wet conditions prevailed over Europe. After 1960, the Atlantic began to cool, and for almost three decades the North American climate turned wetter and cooler whereas Europe experienced cooler and dryer conditions. However, the shortness of the historical observations compared to the AMV period suggested by longer proxy (~60-80yr) does not allow to firmly conclude on the causal effect of the AMV. We use a model approach to isolate the causal role of the AMV on the occurrence of extreme events over Europe and North America. We present experiments based on two GFDL global climate models, a low resolution version, CM2.1 and a higher resolution model for the atmospheric component, FLOR. In both model experiments sea surface temperatures in the North Atlantic sector are restored to the observed AMV pattern, while the other basins are left fully coupled. In order to explore and robustly isolate the AMV impacts on extreme events, we use large ensemble simulations (100 members for CM2.1 and 50 for FLOR) that we run for 20 years. We find that a positive phase of the AMV increases the frequency of occurrence of drought over North America and of extremely cold/warm conditions over Northern/Central Europe during winter/summer. Interestingly, we find that the AMV impacts on these extreme conditions are modulated by the Pacific response to the AMV itself. Members that develop a weak Pacific response show more extreme events over Europe whereas those that develop a strong Pacific response show more extreme events over North America.

EMA beamline at SIRIUS: extreme condition X-ray methods of analysis

International Nuclear Information System (INIS)

Souza Neto, Narcizo

2016-01-01

Full text: The EMA beamline (Extreme condition X-ray Methods of Analysis) is one of the hard x-ray undulator beamlines within the first phase of the new synchrotron source in Brazil (Sirius project). This beamline is thought to make a difference where a high brilliance (high flux of up to 2 x 10 14 photons/sec with beam size down to 0.5 x 0.5 μm 2 ) is essential, which is the case for extreme pressures that require small focus and time-resolved that require high photon flux. With that in mind we propose the beamline to have two experimental hutches to cover most of the extreme condition techniques today employed at synchrotron laboratories worldwide. These two stations are thought to provide the general infrastructure for magnets and lasers experiments, which may evolve as new scientific problems appear. In addition to the hutches, support laboratories will be strongly linked and supportive to the experiments at the beamline, covering high pressure instrumentations using diamond anvil cells and pump-and-probe requirements for ultrafast and high power lasers. Along these lines, we will describe the following techniques covered at this beamline: magnetic spectroscopy (XMCD) and scattering (XRMS) under high pressure and very low temperature in order to fully probe both ferromagnetic and antiferromagnetic materials and the dependence with pressure; extreme pressure and temperature XRD and XAS experiments using very small diamond culet anvils and high power lasers. (author)

EMA beamline at SIRIUS: extreme condition X-ray methods of analysis

Energy Technology Data Exchange (ETDEWEB)

Souza Neto, Narcizo, E-mail: narcizo.souza@lnls.br [Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, SP (Brazil)

2016-07-01

Full text: The EMA beamline (Extreme condition X-ray Methods of Analysis) is one of the hard x-ray undulator beamlines within the first phase of the new synchrotron source in Brazil (Sirius project). This beamline is thought to make a difference where a high brilliance (high flux of up to 2 x 10{sup 14} photons/sec with beam size down to 0.5 x 0.5 μm{sup 2}) is essential, which is the case for extreme pressures that require small focus and time-resolved that require high photon flux. With that in mind we propose the beamline to have two experimental hutches to cover most of the extreme condition techniques today employed at synchrotron laboratories worldwide. These two stations are thought to provide the general infrastructure for magnets and lasers experiments, which may evolve as new scientific problems appear. In addition to the hutches, support laboratories will be strongly linked and supportive to the experiments at the beamline, covering high pressure instrumentations using diamond anvil cells and pump-and-probe requirements for ultrafast and high power lasers. Along these lines, we will describe the following techniques covered at this beamline: magnetic spectroscopy (XMCD) and scattering (XRMS) under high pressure and very low temperature in order to fully probe both ferromagnetic and antiferromagnetic materials and the dependence with pressure; extreme pressure and temperature XRD and XAS experiments using very small diamond culet anvils and high power lasers. (author)

Quantum Statistical Entropy of Non-extreme and Nearly Extreme Black Holes in Higher-Dimensional Space-Time

Institute of Scientific and Technical Information of China (English)

XU Dian-Yan

2003-01-01

The free energy and entropy of Reissner-Nordstrom black holes in higher-dimensional space-time are calculated by the quantum statistic method with a brick wall model. The space-time of the black holes is divided into three regions: region 1, (r > r0); region 2, (r0 > r > n); and region 3, (T-J > r > 0), where r0 is the radius of the outer event horizon, and r, is the radius of the inner event horizon. Detailed calculation shows that the entropy contributed by region 2 is zero, the entropy contributed by region 1 is positive and proportional to the outer event horizon area, the entropy contributed by region 3 is negative and proportional to the inner event horizon area. The total entropy contributed by all the three regions is positive and proportional to the area difference between the outer and inner event horizons. As rt approaches r0 in the nearly extreme case, the total quantum statistical entropy approaches zero.

Wireless pilot monitoring system for extreme race conditions.

Science.gov (United States)

Pino, Esteban J; Arias, Diego E; Aqueveque, Pablo; Melin, Pedro; Curtis, Dorothy W

2012-01-01

This paper presents the design and implementation of an assistive device to monitor car drivers under extreme conditions. In particular, this system is designed in preparation for the 2012 Atacama Solar Challenge to be held in the Chilean desert. Actual preliminary results show the feasibility of such a project including physiological and ambient sensors, real-time processing algorithms, wireless data transmission and a remote monitoring station. Implementation details and field results are shown along with a discussion of the main problems found in real-life telemetry monitoring.

Quantifying the daily economic impact of extreme space weather due to failure in electricity transmission infrastructure

Science.gov (United States)

Oughton, Edward J.; Skelton, Andrew; Horne, Richard B.; Thomson, Alan W. P.; Gaunt, Charles T.

2017-01-01

Extreme space weather due to coronal mass ejections has the potential to cause considerable disruption to the global economy by damaging the transformers required to operate electricity transmission infrastructure. However, expert opinion is split between the potential outcome being one of a temporary regional blackout and of a more prolonged event. The temporary blackout scenario proposed by some is expected to last the length of the disturbance, with normal operations resuming after a couple of days. On the other hand, others have predicted widespread equipment damage with blackout scenarios lasting months. In this paper we explore the potential costs associated with failure in the electricity transmission infrastructure in the U.S. due to extreme space weather, focusing on daily economic loss. This provides insight into the direct and indirect economic consequences of how an extreme space weather event may affect domestic production, as well as other nations, via supply chain linkages. By exploring the sensitivity of the blackout zone, we show that on average the direct economic cost incurred from disruption to electricity represents only 49% of the total potential macroeconomic cost. Therefore, if indirect supply chain costs are not considered when undertaking cost-benefit analysis of space weather forecasting and mitigation investment, the total potential macroeconomic cost is not correctly represented. The paper contributes to our understanding of the economic impact of space weather, as well as making a number of key methodological contributions relevant for future work. Further economic impact assessment of this threat must consider multiday, multiregional events.

Triticale in the years with extreme weather conditions

Directory of Open Access Journals (Sweden)

Nožinić Miloš

2009-01-01

Full Text Available Unlike other grain crops, the area under triticale in the Republic of Srpska has been expanding every year. Since the introduction of this plant species in the broad production began a few years ago, the finding of the optimal variety agrotechnique in different environmental conditions has great importance. This paper deals with the results of the trials from seven locations in two very extreme vegetation seasons (2002/03, 2006/07. High yield of triticale on the location Banja Luka (150 m alt. with five triticale varieties in four sowing rates in the replication trial in very unfavorable weather conditions in 2003, points to emphasized triticale tolerance to high temperatures and drought. High grain yield of triticale in the trials on the locations Banja Luka, Butmir (460 m alt. and Živince (230 m alt. was obtained in 2007 too, when all vegetation months had higher mean temperature than long term average, what is a unique appearance in the entire 'meteorological history'. In the paper the appearance of the earliest triticale heading is described and explained. It happened at one production trial on Manjača (250 m alt. in the first decade of March in 2007. On the another location on Manjača (450 m alt., in the macrotrial, rye showed much higher tolerance to extreme soil acidity, than triticale. Obtained results and unusual appearances on triticale are helpful for the further research of the stability and adaptability of more important triticale traits. .

Modelling of air-conditioned and heated spaces

Energy Technology Data Exchange (ETDEWEB)

Moehl, U

1987-01-01

A space represents a complex system involving numerous components, manipulated variables and disturbances which need to be described if dynamic behaviour of space air is to be determined. A justifiable amount of simulation input is determined by the application of adjusted modelling of the individual components. The determination of natural air exchange in heated spaces and of space-air flow in air-conditioned space are a primary source of uncertainties. (orig.).

Modeling Spatial Dependence of Rainfall Extremes Across Multiple Durations

Science.gov (United States)

Le, Phuong Dong; Leonard, Michael; Westra, Seth

2018-03-01

Determining the probability of a flood event in a catchment given that another flood has occurred in a nearby catchment is useful in the design of infrastructure such as road networks that have multiple river crossings. These conditional flood probabilities can be estimated by calculating conditional probabilities of extreme rainfall and then transforming rainfall to runoff through a hydrologic model. Each catchment's hydrological response times are unlikely to be the same, so in order to estimate these conditional probabilities one must consider the dependence of extreme rainfall both across space and across critical storm durations. To represent these types of dependence, this study proposes a new approach for combining extreme rainfall across different durations within a spatial extreme value model using max-stable process theory. This is achieved in a stepwise manner. The first step defines a set of common parameters for the marginal distributions across multiple durations. The parameters are then spatially interpolated to develop a spatial field. Storm-level dependence is represented through the max-stable process for rainfall extremes across different durations. The dependence model shows a reasonable fit between the observed pairwise extremal coefficients and the theoretical pairwise extremal coefficient function across all durations. The study demonstrates how the approach can be applied to develop conditional maps of the return period and return level across different durations.

Extremely Severe Space Weather and Geomagnetically Induced Currents in Regions with Locally Heterogeneous Ground Resistivity

Science.gov (United States)

Fujita, Shigeru; Kataoka, Ryuho; Pulkkinen, Antti; Watari, Shinichi

2016-01-01

Large geomagnetically induced currents (GICs) triggered by extreme space weather events are now regarded as one of the serious natural threats to the modern electrified society. The risk is described in detail in High-Impact, Low-Frequency Event Risk, A Jointly-Commissioned Summary Report of the North American Electric Reliability Corporation and the US Department of Energy's November 2009 Workshop, June 2010. For example, the March 13-14,1989 storm caused a large-scale blackout affecting about 6 million people in Quebec, Canada, and resulting in substantial economic losses in Canada and the USA (Bolduc 2002). Therefore, European and North American nations have invested in GIC research such as the Solar Shield project in the USA (Pulkkinen et al. 2009, 2015a). In 2015, the Japanese government (Ministry of Economy, Trade and Industry, METI) acknowledged the importance of GIC research in Japan. After reviewing the serious damages caused by the 2011 Tohoku-Oki earthquake, METI recognized the potential risk to the electric power grid posed by extreme space weather. During extreme events, GICs can be concerning even in mid- and low-latitude countries and have become a global issue.

Proceedings of the third symposium on science of hadrons under extreme conditions

Energy Technology Data Exchange (ETDEWEB)

Chiba, Satoshi (ed.) [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2001-09-01

The third symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on January 29 to 31, 2001. The symposium was devoted for discussions and presentations of research results in wide variety of hadron physics such as nuclear matter, high-energy nuclear reactions, quantum chromodynamics, neutron stars, supernovae, nucleosynthesis as well as finite nuclei to understand various aspects of hadrons under extreme conditions. Twenty two papers on these topics presented at the symposium, including a special talk on the present status of JAERI-KEK joint project on high-intensity proton accelerator, aroused lively discussions among approximately 40 participants. The 20 of the presented papers are indexed individually. (J.P.N.)

Extreme Water Deficit in Brazil Detected from Space

Science.gov (United States)

Vieira Getirana

2016-01-01

Extreme droughts have caused significant socioeconomic and environmental damage worldwide. In Brazil, ineffective energy development and water management policies have magnified the impacts of recent severe droughts, which include massive agricultural losses, water supply restrictions, and energy rationing. Spaceborne remote sensing data advance our understanding of the spatiotemporal variability of large-scale droughts and enhance the detection and monitoring of extreme water-related events. In this study, data derived from the Gravity Recovery and Climate Experiment (GRACE) mission are used to detect and quantify an extended major drought over eastern Brazil and provide estimates of impacted areas and region-specific water deficits. Two structural breakpoint detection methods were applied to time series of GRACE-based terrestrial water storage anomalies (TWSA), determining when two abrupt changes occurred. One, in particular, defines the beginning of the current drought. Using TWSA, a water loss rate of 26.1 cmyr21 over southeastern Brazil was detected from 2012 to 2015. Based on analysis of Global Land Data Assimilation System(GLDAS) outputs, the extreme drought is mostly related to lower-than-usual precipitation rates, resulting in high soil moisture depletion and lower-than-usual rates of evapotranspiration. A reduction of 2023 of precipitation over an extended period of 3 years is enough to raise serious water scarcity conditions in the country. Correlations between monthly time series of both grid-based TWSA and ground-based water storage measurements at 16 reservoirs located within southeastern Brazil varied from 0.42 to 0.82. Differences are mainly explained by reservoir sizes and proximity to the drought nucleus.

Community responses to extreme climatic conditions

Directory of Open Access Journals (Sweden)

Frédéric JIGUET, Lluis BROTONS, Vincent DEVICTOR

2011-06-01

Full Text Available Species assemblages and natural communities are increasingly impacted by changes in the frequency and severity of extreme climatic events. Here we propose a brief overview of expected and demonstrated direct and indirect impacts of extreme events on animal communities. We show that differential impacts on basic biological parameters of individual species can lead to strong changes in community composition and structure with the potential to considerably modify the functional traits of the community. Sudden disequilibria have even been shown to induce irreversible shifts in marine ecosystems, while cascade effects on various taxonomic groups have been highlighted in Mediterranean forests. Indirect effects of extreme climatic events are expected when event-induced habitat changes (e.g. soil stability, vegetation composition, water flows altered by droughts, floods or hurricanes have differential consequences on species assembled within the communities. Moreover, in increasing the amplitude of trophic mismatches, extreme events are likely to turn many systems into ecological traps under climate change. Finally, we propose a focus on the potential impacts of an extreme heat wave on local assemblages as an empirical case study, analysing monitoring data on breeding birds collected in France. In this example, we show that despite specific populations were differently affected by local temperature anomalies, communities seem to be unaffected by a sudden heat wave. These results suggest that communities are tracking climate change at the highest possible rate [Current Zoology 57 (3: 406–413, 2011].

The Space Medicine Exploration Medical Condition List

Science.gov (United States)

Watkins, Sharmi; Barr, Yael; Kerstman, Eric

2011-01-01

Exploration Medical Capability (ExMC) is an element of NASA s Human Research Program (HRP). ExMC's goal is to address the risk of the "Inability to Adequately Recognize or Treat an Ill or Injured Crewmember." This poster highlights the approach ExMC has taken to address this risk. The Space Medicine Exploration Medical Condition List (SMEMCL) was created to define the set of medical conditions that are most likely to occur during exploration space flight missions. The list was derived from the International Space Station Medical Checklist, the Shuttle Medical Checklist, in-flight occurrence data from the Lifetime Surveillance of Astronaut Health, and NASA subject matter experts. The list of conditions was further prioritized for eight specific design reference missions with the assistance of the ExMC Advisory Group. The purpose of the SMEMCL is to serve as an evidence-based foundation for the conditions that could affect a crewmember during flight. This information is used to ensure that the appropriate medical capabilities are available for exploration missions.

Proceedings of the workshop on scattering experiments under extreme conditions

International Nuclear Information System (INIS)

Sakai, N.; Ikeda, H.; Ando, M.

1991-10-01

In the National Laboratory for High Energy Physics (KEK), as the research facilities, there are Photon Factory, the facility for utilizing the booster and University of Tokyo Meson Science Research Center. For the research on physical properties, it is very important to do structural analysis in a broad sense and to observe the behavior of quasiparticles in solids. The X-ray and pulsed neutrons required for these researches can be obtained in a single laboratory in KEK, and it is rare in the world. At this opportunity of the workshop on scattering experiments under extreme conditions, it is hoped that the positive interchange between both PF and booster groups will be carried out. The research on magnetic substances using X-ray is a most noteworthy utilization of synchrotron radiation. The discovery of X-ray resonance magnetic scattering by K. Namikawa is one of the remarkable researches using synchrotron radiation in the world. When the extreme conditions around samples are prepared, the quality of signals for the research on physical properties is to be heightened. In this report, the researches on physical properties under ultrahigh pressure and ultralow temperature are reported. (K.I.)

Inelastic X-ray scattering experiments at extreme conditions: high temperatures and high pressures

Directory of Open Access Journals (Sweden)

S.Hosokawa

2008-03-01

Full Text Available In this article, we review the present status of experimental techniques under extreme conditions of high temperature and high pressure used for inelastic X-ray scattering (IXS experiments of liquid metals, semiconductors, molten salts, molecular liquids, and supercritical water and methanol. For high temperature experiments, some types of single-crystal sapphire cells were designed depending on the temperature of interest and the sample thickness for the X-ray transmission. Single-crystal diamond X-ray windows attached to the externally heated high-pressure vessel were used for the IXS experiment of supercritical water and methanol. Some typical experimental results are also given, and the perspective of IXS technique under extreme conditions is discussed.

Conditions and constraints of food processing in space

Science.gov (United States)

Fu, B.; Nelson, P. E.; Mitchell, C. A. (Principal Investigator)

1994-01-01

Requirements and constraints of food processing in space include a balanced diet, food variety, stability for storage, hardware weight and volume, plant performance, build-up of microorganisms, and waste processing. Lunar, Martian, and space station environmental conditions include variations in atmosphere, day length, temperature, gravity, magnetic field, and radiation environment. Weightlessness affects fluid behavior, heat transfer, and mass transfer. Concerns about microbial behavior include survival on Martian and lunar surfaces and in enclosed environments. Many present technologies can be adapted to meet space conditions.

High-energy synchrotron x-ray diffraction studies on disordered materials. From ambient condition to an extreme condition

International Nuclear Information System (INIS)

Kohara, Shinji; Ohishi, Yasuo; Suzuya, Kentaro; Takata, Masaki

2007-01-01

High-energy x-rays from synchrotron radiation source allow us to measure high-quality diffraction data of the disordered materials from under ambient condition to an extreme condition, which is necessary to reveal the detailed structure of glass, liquid, and amorphous materials. We introduce the high-energy x-ray diffraction beamline and dedicated diffractometer for glass, liquid, and amorphous materials with the recent developments of ancillary equipments. Furthermore our recent studies on the structures of disordered materials reviewed. (author)

A telescope for observation from space of extreme lightnings in the upper atmosphere

International Nuclear Information System (INIS)

Nam, S.; Artikova, S.; Chung, T.; Garipov, G.; Jeon, J.A.; Jeong, S.; Jin, J.Y.; Khrenov, B.A.; Kim, J.E.; Kim, M.; Kim, Y.K.; Klimov, P.; Lee, J.; Lee, H.Y.; Na, G.W.; Oh, S.J.; Panasyuk, M.; Park, I.H.; Park, J.H.; Park, Y.-S.

2008-01-01

A new type of telescope with a wide field-of-view and functions of fast zoom-in has been introduced. Two kinds of MEMS (Micro-Electro-Mechanical Systems) micromirrors, digital and analog, are used for reflectors of the telescope, placed at different focal lengths. We apply this technology to the observation from space of TLE (Transient Luminous Events), extremely large transient sparks occurring at the upper atmosphere. TLE are one type of important backgrounds to be understood for future space observation of UHECR (Ultra-High Energy Cosmic Rays). The launch of the payload carried by a Russian microsatellite is foreseen in the middle of 2008

Effective interactions for extreme isospin conditions; Interactions effectives pour des conditions extremes d`isospin

Energy Technology Data Exchange (ETDEWEB)

Chabanat, E.

1995-01-01

One of the main goal in nuclear physics research is the study of nuclei in extreme conditions of spin and isospin. The more performing tools for theoretical predictions in this field are microscopic methods such as the Hartree-Fock one based on independent particle approximation. The main ingredient for such an approach is the effective nucleon-nucleon interaction. The actual trend being the study of nuclei more and more far from the stability valley, it is necessary to cast doubt over the validity of usual effective interaction. This work constitute a study on the way one can construct a new interaction allowing some theoretical predictions on nuclei far from the stability. We have thus made a complete study of symmetric infinite nuclear matter and asymmetric one up to pure neutron matter. One shows that the asymmetry coefficient, which was considered until now as fixing isospin properties, is not sufficient to have a correct description of very exotic isospin states. A new type of constraint is shown for fixing this degree of freedom: the neutron matter equation of state. One include this equation of state, taken from a theoretical model giving a good description of radii and masses of neutron stars. One can thus expect to build up new Skyrme interaction with realistic properties of ground state of very neutron-rich nuclei. (author). 63 refs., 68 figs., 15 tabs.

Organizing of medical ensurance of human population under extreme conditions. Summaries of reports of scientific-practical conference

International Nuclear Information System (INIS)

1994-01-01

Summary of reports are presented of Scientific-Practical conference on the organizing of medical ensurance of human population under extreme conditions including radiation accidents. The conference held in Moscow in October, 1994. It covered problems of organizing medical ensurance of population, medical surveillance problems, sanitary-hygienic and epidemiological problems (including radiation protection), and medical provision problems under extreme conditions

The role of extreme orbits in the global organization of periodic regions in parameter space for one dimensional maps

Energy Technology Data Exchange (ETDEWEB)

Costa, Diogo Ricardo da, E-mail: diogo_cost@hotmail.com [Departamento de Física, UNESP – Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); Hansen, Matheus [Departamento de Física, UNESP – Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); Instituto de Física, Univ. São Paulo, Rua do Matão, Cidade Universitária, 05314-970, São Paulo – SP (Brazil); Guarise, Gustavo [Departamento de Física, UNESP – Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); Medrano-T, Rene O. [Departamento de Ciências Exatas e da Terra, UNIFESP – Universidade Federal de São Paulo, Rua São Nicolau, 210, Centro, 09913-030, Diadema, SP (Brazil); Department of Mathematics, Imperial College London, London SW7 2AZ (United Kingdom); Leonel, Edson D. [Departamento de Física, UNESP – Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, 34151 Trieste (Italy)

2016-04-22

We show that extreme orbits, trajectories that connect local maximum and minimum values of one dimensional maps, play a major role in the parameter space of dissipative systems dictating the organization for the windows of periodicity, hence producing sets of shrimp-like structures. Here we solve three fundamental problems regarding the distribution of these sets and give: (i) their precise localization in the parameter space, even for sets of very high periods; (ii) their local and global distributions along cascades; and (iii) the association of these cascades to complicate sets of periodicity. The extreme orbits are proved to be a powerful indicator to investigate the organization of windows of periodicity in parameter planes. As applications of the theory, we obtain some results for the circle map and perturbed logistic map. The formalism presented here can be extended to many other different nonlinear and dissipative systems. - Highlights: • Extreme orbits and the organization of periodic regions in parameter space. • One-dimensional dissipative mappings. • The circle map and also a time perturbed logistic map were studied.

The role of extreme orbits in the global organization of periodic regions in parameter space for one dimensional maps

International Nuclear Information System (INIS)

Costa, Diogo Ricardo da; Hansen, Matheus; Guarise, Gustavo; Medrano-T, Rene O.; Leonel, Edson D.

2016-01-01

We show that extreme orbits, trajectories that connect local maximum and minimum values of one dimensional maps, play a major role in the parameter space of dissipative systems dictating the organization for the windows of periodicity, hence producing sets of shrimp-like structures. Here we solve three fundamental problems regarding the distribution of these sets and give: (i) their precise localization in the parameter space, even for sets of very high periods; (ii) their local and global distributions along cascades; and (iii) the association of these cascades to complicate sets of periodicity. The extreme orbits are proved to be a powerful indicator to investigate the organization of windows of periodicity in parameter planes. As applications of the theory, we obtain some results for the circle map and perturbed logistic map. The formalism presented here can be extended to many other different nonlinear and dissipative systems. - Highlights: • Extreme orbits and the organization of periodic regions in parameter space. • One-dimensional dissipative mappings. • The circle map and also a time perturbed logistic map were studied.

Improving multisensor estimation of heavy-to-extreme precipitation via conditional bias-penalized optimal estimation

Science.gov (United States)

Kim, Beomgeun; Seo, Dong-Jun; Noh, Seong Jin; Prat, Olivier P.; Nelson, Brian R.

2018-01-01

A new technique for merging radar precipitation estimates and rain gauge data is developed and evaluated to improve multisensor quantitative precipitation estimation (QPE), in particular, of heavy-to-extreme precipitation. Unlike the conventional cokriging methods which are susceptible to conditional bias (CB), the proposed technique, referred to herein as conditional bias-penalized cokriging (CBPCK), explicitly minimizes Type-II CB for improved quantitative estimation of heavy-to-extreme precipitation. CBPCK is a bivariate version of extended conditional bias-penalized kriging (ECBPK) developed for gauge-only analysis. To evaluate CBPCK, cross validation and visual examination are carried out using multi-year hourly radar and gauge data in the North Central Texas region in which CBPCK is compared with the variant of the ordinary cokriging (OCK) algorithm used operationally in the National Weather Service Multisensor Precipitation Estimator. The results show that CBPCK significantly reduces Type-II CB for estimation of heavy-to-extreme precipitation, and that the margin of improvement over OCK is larger in areas of higher fractional coverage (FC) of precipitation. When FC > 0.9 and hourly gauge precipitation is > 60 mm, the reduction in root mean squared error (RMSE) by CBPCK over radar-only (RO) is about 12 mm while the reduction in RMSE by OCK over RO is about 7 mm. CBPCK may be used in real-time analysis or in reanalysis of multisensor precipitation for which accurate estimation of heavy-to-extreme precipitation is of particular importance.

Atmospheric conditions and weather regimes associated with extreme winter dry spells over the Mediterranean basin

Science.gov (United States)

Raymond, Florian; Ullmann, Albin; Camberlin, Pierre; Oueslati, Boutheina; Drobinski, Philippe

2018-06-01

Very long dry spell events occurring during winter are natural hazards to which the Mediterranean region is extremely vulnerable, because they can lead numerous impacts for environment and society. Four dry spell patterns have been identified in a previous work. Identifying the main associated atmospheric conditions controlling the dry spell patterns is key to better understand their dynamics and their evolution in a changing climate. Except for the Levant region, the dry spells are generally associated with anticyclonic blocking conditions located about 1000 km to the Northwest of the affected area. These anticyclonic conditions are favourable to dry spell occurrence as they are associated with subsidence of cold and dry air coming from boreal latitudes which bring low amount of water vapour and non saturated air masses, leading to clear sky and absence of precipitation. These extreme dry spells are also partly related to the classical four Euro-Atlantic weather regimes are: the two phases of the North Atlantic Oscillation, the Scandinavian "blocking" or "East-Atlantic", and the "Atlantic ridge". Only the The "East-Atlantic", "Atlantic ridge" and the positive phase of the North Atlantic Oscillation are frequently associated with extremes dry spells over the Mediterranean basin but they do not impact the four dry spell patterns equally. Finally long sequences of those weather regimes are more favourable to extreme dry spells than short sequences. These long sequences are associated with the favourable prolonged and reinforced anticyclonic conditions

Life under Multiple Extreme Conditions: Diversity and Physiology of the Halophilic Alkalithermophiles

Science.gov (United States)

Wiegel, Juergen

2012-01-01

Around the world, there are numerous alkaline, hypersaline environments that are heated either geothermally or through intense solar radiation. It was once thought that such harsh environments were inhospitable and incapable of supporting a variety of life. However, numerous culture-dependent and -independent studies revealed the presence of an extensive diversity of aerobic and anaerobic bacteria and archaea that survive and grow under these multiple harsh conditions. This diversity includes the halophilic alkalithermophiles, a novel group of polyextremophiles that require for growth and proliferation the multiple extremes of high salinity, alkaline pH, and elevated temperature. Life under these conditions undoubtedly involves the development of unique physiological characteristics, phenotypic properties, and adaptive mechanisms that enable control of membrane permeability, control of intracellular osmotic balance, and stability of the cell wall, intracellular proteins, and other cellular constituents. This minireview highlights the ecology and growth characteristics of the extremely halophilic alkalithermophiles that have been isolated thus far. Biochemical, metabolic, and physiological properties of the extremely halophilic alkalithermophiles are described, and their roles in resistance to the combined stressors of high salinity, alkaline pH, and high temperature are discussed. The isolation of halophilic alkalithermophiles broadens the physicochemical boundaries for life and extends the boundaries for the combinations of the maximum salinity, pH, and temperature that can support microbial growth. PMID:22492435

"On-off-on" switchable sensor: a fluorescent spiropyran responds to extreme pH conditions and its bioimaging applications.

Science.gov (United States)

Wan, Shulin; Zheng, Yang; Shen, Jie; Yang, Wantai; Yin, Meizhen

2014-11-26

A novel spiropyran that responds to both extreme acid and extreme alkali and has an "on-off-on" switch is reported. Benzoic acid at the indole N-position and carboxyl group at the indole 6-position contribute to the extreme acid response. The ionizations of carboxyl and phenolic hydroxyl groups cause the extreme alkali response. Moreover, the fluorescent imaging in bacterial cells under extreme pH conditions supports the mechanism of pH response.

Space-compatible strain gauges as an integration aid for the James Webb Space Telescope Mid-Infrared Instrument

DEFF Research Database (Denmark)

Samara-Ratna, Piyal; Sykes, Jon; Bicknell, Chris

2015-01-01

Space instruments are designed to be highly optimised, mass efficient hardware required to operate in extreme environments. Building and testing is extremely costly, and damage that appears to have no impact on performance at normal ambient conditions can have disastrous implications when...... to protect the structure from damage. Compatible with space flight requirements, the gauges have been used in both ambient and cryogenic environments and were successfully used to support various tasks including integration to the spacecraft. The article also discusses limitations to using the strain gauge...

The extreme condition analyzing for NEMPI shielding of electronic system in high-intensity pulsed radiation diagnosing

International Nuclear Information System (INIS)

Cheng Xiaolei; Liu Fang; Ouyang Xiaoping

2012-01-01

The difficulty for estimating the NEMPI (electromagnetic pulsed interference caused by the nuclear reaction) on the electronic system in high-intensity pulsed radiation diagnosing is analyzed in this article. To solve the difficulty, a method called 'Extreme Condition Analyzing' is presented for estimating the NEMPI conservatively and reliably. Through an extreme condition hypothesizing which could be described as 'Entire Coupling of Electric Field Energy', the E max (maximum electric field intensity which could be endured by the electronic system in the high-intensity pulsed radiation) could be figured out without any other information of the EMP caused by the nuclear reaction. Then a feasibility inspection is introduced, to confirm that the EMPI shielding request according to E max is not too extreme to be achieved. (authors)

Molecular Mechanisms of Survival Strategies in Extreme Conditions

Directory of Open Access Journals (Sweden)

Federica Migliardo

2012-12-01

Full Text Available Today, one of the major challenges in biophysics is to disclose the molecular mechanisms underlying biological processes. In such a frame, the understanding of the survival strategies in extreme conditions received a lot of attention both from the scientific and applicative points of view. Since nature provides precious suggestions to be applied for improving the quality of life, extremophiles are considered as useful model-systems. The main goal of this review is to present an overview of some systems, with a particular emphasis on trehalose playing a key role in several extremophile organisms. The attention is focused on the relation among the structural and dynamic properties of biomolecules and bioprotective mechanisms, as investigated by complementary spectroscopic techniques at low- and high-temperature values.

Extreme environment electronics

CERN Document Server

Cressler, John D

2012-01-01

Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world's foremost exp

S-Denying of the Signature Conditions Expands General Relativity's Space

Directory of Open Access Journals (Sweden)

Rabounski D.

2006-07-01

Full Text Available We apply the S-denying procedure to signature conditions in a four-dimensional pseudo-Riemannian space — i. e. we change one (or even all of the conditions to be partially true and partially false. We obtain five kinds of expanded space-time for General Relativity. Kind I permits the space-time to be in collapse. Kind II permits the space-time to change its own signature. Kind III has peculiarities, linked to the third signature condition. Kind IV permits regions where the metric fully degenerates: there may be non-quantum teleportation, and a home for virtual photons. Kind V is common for kinds I, II, III, and IV.

Mapping probabilities of extreme continental water storage changes from space gravimetry

Science.gov (United States)

Kusche, J.; Eicker, A.; Forootan, E.; Springer, A.; Longuevergne, L.

2016-12-01

Using data from the Gravity Recovery and Climate Experiment (GRACE) mission, we derive statistically robust 'hotspot' regions of high probability of peak anomalous - i.e. with respect to the seasonal cycle - water storage (of up to 0.7 m one-in-five-year return level) and flux (up to 0.14 m/mon). Analysis of, and comparison with, up to 32 years of ERA-Interim reanalysis fields reveals generally good agreement of these hotspot regions to GRACE results, and that most exceptions are located in the Tropics. However, a simulation experiment reveals that differences observed by GRACE are statistically significant, and further error analysis suggests that by around the year 2020 it will be possible to detect temporal changes in the frequency of extreme total fluxes (i.e. combined effects of mainly precipitation and floods) for at least 10-20% of the continental area, assuming that we have a continuation of GRACE by its follow-up GRACE-FO. J. Kusche et al. (2016): Mapping probabilities of extreme continental water storage changes from space gravimetry, Geophysical Research Letters, accepted online, doi:10.1002/2016GL069538

Numerical Analysis of Flood modeling of upper Citarum River under Extreme Flood Condition

Science.gov (United States)

Siregar, R. I.

2018-02-01

This paper focuses on how to approach the numerical method and computation to analyse flood parameters. Water level and flood discharge are the flood parameters solved by numerical methods approach. Numerical method performed on this paper for unsteady flow conditions have strengths and weaknesses, among others easily applied to the following cases in which the boundary irregular flow. The study area is in upper Citarum Watershed, Bandung, West Java. This paper uses computation approach with Force2 programming and HEC-RAS to solve the flow problem in upper Citarum River, to investigate and forecast extreme flood condition. Numerical analysis based on extreme flood events that have occurred in the upper Citarum watershed. The result of water level parameter modeling and extreme flood discharge compared with measurement data to analyse validation. The inundation area about flood that happened in 2010 is about 75.26 square kilometres. Comparing two-method show that the FEM analysis with Force2 programs has the best approach to validation data with Nash Index is 0.84 and HEC-RAS that is 0.76 for water level. For discharge data Nash Index obtained the result analysis use Force2 is 0.80 and with use HEC-RAS is 0.79.

Numerical tools to predict the environmental loads for offshore structures under extreme weather conditions

Science.gov (United States)

Wu, Yanling

2018-05-01

In this paper, the extreme waves were generated using the open source computational fluid dynamic (CFD) tools — OpenFOAM and Waves2FOAM — using linear and nonlinear NewWave input. They were used to conduct the numerical simulation of the wave impact process. Numerical tools based on first-order (with and without stretching) and second-order NewWave are investigated. The simulation to predict force loading for the offshore platform under the extreme weather condition is implemented and compared.

Mean versus extreme climate in the Mediterranean region and its sensitivity to future global warming conditions

Energy Technology Data Exchange (ETDEWEB)

Paeth, H.; Hense, A. [Meteorological Inst., Univ. Bonn (Germany)

2005-06-01

The Mediterranean region (MTR) has been supposed to be very sensitive to changes in land surface and atmospheric greenhouse-gas (GHG) concentrations. Particularly, an intensification of climate extremes may be associated with severe socio-economic implications. Here, we present an analysis of climate mean and extreme conditions in this subtropical area based on regional climate model experiments, simulating the present-day and possible future climate. The analysis of extreme values (EVs) is based on the assumption that the extremes of daily precipitation and near-surface temperature are well fitted by the Generalized Pareto distribution (GPD). Return values of extreme daily events are determined using the method of L-moments. Particular emphasis is laid on the evaluation of the return values with respect to the uncertainty range of the estimate as derived from a Monte Carlo sampling approach. During the most recent 25 years the MTR has become dryer in spring but more humid especially in the western part in autumn and winter. At the same time, the whole region has been subject to a substantial warming. The strongest rainfall extremes are simulated in autumn over the Mediterranean Sea around Italy. Temperature extremes are most pronounced over the land masses, especially over northern Africa. Given the large uncertainty of the EV estimate, only 1-year return values are further analysed. During recent decades, statistically significant changes in extremes are only found for temperature. Future climate conditions may come along with a decrease in mean and extreme precipitation during the cold season, whereas an intensification of the hydrological cycle is predicted in summer and autumn. Temperature is predominantly affected over the Iberian Peninsula and the eastern part of the MTR. In many grid boxes, the signals are blurred out due to the large amount of uncertainty in the EV estimate. Thus, a careful analysis is required when making inferences about the future

Life at extreme conditions: neutron scattering studies of biological molecules suggest that evolution selected dynamics

International Nuclear Information System (INIS)

Zaccai, Joseph Giuseppe

2008-01-01

The short review concentrates on recent work performed at the neutrons in biology laboratories of the Institut Laue Langevin and Institut de Biologie Structurale in Grenoble. Extremophile organisms have been discovered that require extreme conditions of temperature, pressure or solvent environment for survival. The existence of such organisms poses a significant challenge in understanding the physical chemistry of their proteins, in view of the great sensitivity of protein structure and stability to the aqueous environment and to external conditions in general. Results of neutron scattering measurements on the dynamics of proteins from extremophile organisms, in vitro as well as in vivo, indicated remarkably how adaptation to extreme conditions involves forces and fluctuation amplitudes that have been selected specifically, suggesting that evolutionary macromolecular selection proceeded via dynamics. The experiments were performed on a halophilic protein, and membrane adapted to high salt, a thermophilic enzyme adapted to high temperature and its mesophilic (adapted to 37 degC) homologue; and in vivo for psychrophilic, mesophilic, thermophilic and hyperthermophilic bacteria, adapted respectively to temperatures of 4 degC, 37 degC, 75 degC and 85 degC. Further work demonstrated the existence of a water component of exceptionally low mobility in an extreme halophile from the Dead Sea, which is not present in mesophile bacterial cells. (author)

Thermoregulatory value of cracking-clay soil shelters for small vertebrates during extreme desert conditions.

Science.gov (United States)

Waudby, Helen P; Petit, Sophie

2017-05-01

Deserts exhibit extreme climatic conditions. Small desert-dwelling vertebrates have physiological and behavioral adaptations to cope with these conditions, including the ability to seek shelter. We investigated the temperature (T) and relative humidity (RH) regulating properties of the soil cracks that characterize the extensive cracking-clay landscapes of arid Australia, and the extent of their use by 2 small marsupial species: fat-tailed and stripe-faced dunnarts (Sminthopsis crassicaudata and Sminthopsis macroura). We measured hourly (over 24-h periods) the T and RH of randomly-selected soil cracks compared to outside conditions, during 2 summers and 2 winters. We tracked 17 dunnarts (8 Sminthopsis crassicaudata and 9 Sminthopsis macroura) to quantify their use of cracks. Cracks consistently moderated microclimate, providing more stable conditions than available from non-crack points, which often displayed comparatively dramatic fluctuations in T and RH. Both dunnart species used crack shelters extensively. Cracks constitute important shelter for small animals during extreme conditions by providing a stable microclimate, which is typically cooler than outside conditions in summer and warmer in winter. Cracks likely play a fundamental sheltering role by sustaining the physiological needs of small mammal populations. Globally, cracking-clay areas are dominated by agricultural land uses, including livestock grazing. Management of these systems should focus not only on vegetation condition, but also on soil integrity, to maintain shelter resources for ground-dwelling fauna. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Quasi-normal modes of extremal BTZ black holes in TMG

Science.gov (United States)

Afshar, Hamid R.; Alishahiha, Mohsen; Mosaffa, Amir E.

2010-08-01

We study the spectrum of tensor perturbations on extremal BTZ black holes in topologically massive gravity for arbitrary values of the coefficient of the Chern-Simons term, μ. Imposing proper boundary conditions at the boundary of the space and at the horizon, we find that the spectrum contains quasi-normal modes.

Offshore wind turbine risk quantification/evaluation under extreme environmental conditions

International Nuclear Information System (INIS)

Taflanidis, Alexandros A.; Loukogeorgaki, Eva; Angelides, Demos C.

2013-01-01

A simulation-based framework is discussed in this paper for quantification/evaluation of risk and development of automated risk assessment tools, focusing on applications to offshore wind turbines under extreme environmental conditions. The framework is founded on a probabilistic characterization of the uncertainty in the models for the excitation, the turbine and its performance. Risk is then quantified as the expected value of some risk consequence measure over the probability distributions considered for the uncertain model parameters. Stochastic simulation is proposed for the risk assessment, corresponding to the evaluation of some associated probabilistic integral quantifying risk, as it allows for the adoption of comprehensive computational models for describing the dynamic turbine behavior. For improvement of the computational efficiency, a surrogate modeling approach is introduced based on moving least squares response surface approximations. The assessment is also extended to a probabilistic sensitivity analysis that identifies the importance of each of the uncertain model parameters, i.e. risk factors, towards the total risk as well as towards each of the failure modes contributing to this risk. The versatility and computational efficiency of the advocated approaches is finally exploited to support the development of standalone risk assessment applets for automated implementation of the probabilistic risk quantification/assessment. -- Highlights: ► A simulation-based risk quantification/assessment framework is discussed. ► Focus is on offshore wind turbines under extreme environmental conditions. ► Approach is founded on probabilistic description of excitation/system model parameters. ► Surrogate modeling is adopted for improved computational efficiency. ► Standalone risk assessment applets for automated implementation are supported

Bridge Management Strategy Based on Extreme User Costs for Bridge Network Condition

Directory of Open Access Journals (Sweden)

Ladislaus Lwambuka

2014-01-01

Full Text Available This paper presents a practical approach for prioritization of bridge maintenance within a given bridge network. The maintenance prioritization is formulated as a multiobjective optimization problem where the simultaneous satisfaction of several conflicting objectives includes minimization of maintenance costs, maximization of bridge deck condition, and minimization of traffic disruption and associated user costs. The prevalence of user cost during maintenance period is twofold; the first case refers to the period of dry season where normally the traffic flow is diverted to alternative routes usually resurfaced to regain traffic access. The second prevalence refers to the absence of alternative routes which is often the case in the least developed countries; in this case the user cost referred to results from the waiting time while the traffic flow is put on hold awaiting accomplishment of the maintenance activity. This paper deals with the second scenario of traffic closure in the absence of alternative diversion routes which in essence results in extreme user cost. The paper shows that the multiobjective optimization approach remains valid for extreme cases of user costs in the absence of detour roads as often is the scenario in countries with extreme poor road infrastructure.

Extreme cosmos

CERN Document Server

Gaensler, Bryan

2011-01-01

The universe is all about extremes. Space has a temperature 270°C below freezing. Stars die in catastrophic supernova explosions a billion times brighter than the Sun. A black hole can generate 10 million trillion volts of electricity. And hypergiants are stars 2 billion kilometres across, larger than the orbit of Jupiter. Extreme Cosmos provides a stunning new view of the way the Universe works, seen through the lens of extremes: the fastest, hottest, heaviest, brightest, oldest, densest and even the loudest. This is an astronomy book that not only offers amazing facts and figures but also re

Extreme wind conditions for a Danish offshore site

DEFF Research Database (Denmark)

Hansen, Kurt S.

2000-01-01

This paper presents an analysis of extreme wind speed gust values measured at a shallow water offshore site and at a coastal onshore site in Denmark. An estimate of 50-year extreme values has been evaluated using a new statistical method. In addition a mean gust shape is determined, based on a la...

An Invariant-Preserving ALE Method for Solids under Extreme Conditions

Energy Technology Data Exchange (ETDEWEB)

Sambasivan, Shiv Kumar [Los Alamos National Laboratory; Christon, Mark A [Los Alamos National Laboratory

2012-07-17

We are proposing a fundamentally new approach to ALE methods for solids undergoing large deformation due to extreme loading conditions. Our approach is based on a physically-motivated and mathematically rigorous construction of the underlying Lagrangian method, vector/tensor reconstruction, remapping, and interface reconstruction. It is transformational because it deviates dramatically from traditionally accepted ALE methods and provides the following set of unique attributes: (1) a three-dimensional, finite volume, cell-centered ALE framework with advanced hypo-/hyper-elasto-plastic constitutive theories for solids; (2) a new physically and mathematically consistent reconstruction method for vector/tensor fields; (3) advanced invariant-preserving remapping algorithm for vector/tensor quantities; (4) moment-of-fluid (MoF) interface reconstruction technique for multi-material problems with solids undergoing large deformations. This work brings together many new concepts, that in combination with emergent cell-centered Lagrangian hydrodynamics methods will produce a cutting-edge ALE capability and define a new state-of-the-art. Many ideas in this work are new, completely unexplored, and hence high risk. The proposed research and the resulting algorithms will be of immediate use in Eulerian, Lagrangian and ALE codes under the ASC program at the lab. In addition, the research on invariant preserving reconstruction/remap of tensor quantities is of direct interest to ongoing CASL and climate modeling efforts at LANL. The application space impacted by this work includes Inertial Confinement Fusion (ICF), Z-pinch, munition-target interactions, geological impact dynamics, shock processing of powders and shaped charges. The ALE framework will also provide a suitable test-bed for rapid development and assessment of hypo-/hyper-elasto-plastic constitutive theories. Today, there are no invariant-preserving ALE algorithms for treating solids with large deformations. Therefore

Distributing urban resilience to extreme precipitation events with green infrastructure

Science.gov (United States)

Montalto, F. A.; Catalano De Sousa, M.; Yu, Z.

2013-12-01

New urban green spaces are being designed to manage stormwater, but their performance in a changing climate is untested. Key questions pertain to the ability of these systems to mitigate flood and sewer overflow concerns during impact of extreme events on, and to withstand (biologically and physically) increased frequency and intensity of drought and flood conditions. In this presentation, we present field data characterizing performance of a bioretention area, a stormwater treatment wetland, and a green roof under Hurricane Irene (2011), Superstorm Sandy (2012), and a variety of extreme precipitation events during the summer of 2013. Specifically, we characterize the fate and volume of incident runon and/or precipitation to the facilities during these extreme events, and compare them to long term monitored performance metrics. We also present laboratory test results documenting how vegetation in these facilities stands up to simulated flood and drought conditions. The results are discussed in the context of predicted climate change, specifically associated with the amount and timing of precipitation.

Ecological and biological systems under extreme conditions

Energy Technology Data Exchange (ETDEWEB)

Zlobin, V S; Nenishkiene, V B

1989-01-01

The behaviour of biological and ecological systems under extreme conditions (high and low temperatures, electromagnetic fields of different frequencies, ultraviolet. X-ray and gamma radiation) is analyzed. The ecosystems of macro- and microalgae living in salt, brackinsh and fresh waters are considered in the evolutional aspect basing on their chemical and biochemical composition taking into account the mechanism of radionuclide uptake by water plant cells, osmotic regulation, water and ice structures, combined water in a living organism. The problems of life-support in cosmic flights and of mastering the planets of the Solar system, for instance Mars and Venus, utilizing some microalgae and bacteria with high adaptive properties are discussed. Abnormal water points and their role in the metabolism of a water plant cell are estimated. The 'life niches' are determined at the temperatures exceeding 100 deg C and the possibility of existence for living organisms in high pressure and temperature is grounded. Attempts are made to change the metabolism of the plant and animal cell by subjecting it to the action of electromagnetic and thermal fields, heavy water, chemical and pharmocological substances changing the structure of bound water. 333 refs.; 79 tabs.

Extreme Sea Conditions in Shallow Water: Estimation based on in-situ measurements

Science.gov (United States)

Le Crom, Izan; Saulnier, Jean-Baptiste

2013-04-01

The design of marine renewable energy devices and components is based, among others, on the assessment of the environmental extreme conditions (winds, currents, waves, and water level) that must be combined together in order to evaluate the maximal loads on a floating/fixed structure, and on the anchoring system over a determined return period. Measuring devices are generally deployed at sea over relatively short durations (a few months to a few years), typically when describing water free surface elevation, and extrapolation methods based on hindcast data (and therefore on wave simulation models) have to be used. How to combine, in a realistic way, the action of the different loads (winds and waves for instance) and which correlation of return periods should be used are highly topical issues. However, the assessment of the extreme condition itself remains a not-fully-solved, crucial, and sensitive task. Above all in shallow water, extreme wave height, Hmax, is the most significant contribution in the dimensioning process of EMR devices. As a case study, existing methodologies for deep water have been applied to SEMREV, the French marine energy test site. The interest of this study, especially at this location, goes beyond the simple application to SEMREV's WEC and floating wind turbines deployment as it could also be extended to the Banc de Guérande offshore wind farm that are planned close by. More generally to pipes and communication cables as it is a redundant problematic. The paper will first present the existing measurements (wave and wind on site), the prediction chain that has been developed via wave models, the extrapolation methods applied to hindcast data, and will try to formulate recommendations for improving this assessment in shallow water.

Safety analysis of casks under extreme impact conditions

International Nuclear Information System (INIS)

Wieser, G.; Qiao, L.; Voelzke, H.; Wolff, D.; Droste, B.

2004-01-01

The determination of the inherent safety of casks under extreme impact conditions has been of increasing interest since the terrorist attacks of 11 September 2001. For nearly three decades BAM has been investigating cask safety under severe accident conditions like drop tests from more than 9 m onto different targets and without impact limiters as well as artificially damaged prototype casks. One of the most critical scenarios for a cask is the centric impact of a dynamic load onto the lid-seal system. This can be caused, for example, by a direct aircraft crash (or just its engine) as well as by an impact due to the collapse of a building, e.g. a nuclear facility storage hall. In this context BAM is developing methods to calculate the deformation of cask components and-with respect to leak-tightness-relative displacements between the metallic seals and their counterparts. This paper presents reflections on modelling of cask structures for finite-element analyses and discusses calculated results of stresses and deformations. Another important aspect is the behaviour of a cask under a lateral impact by aircraft or fragments of a building. Examples of the kinetic reaction (cask acceleration due to the fragments, subsequent contact with neighbouring structures like the ground, buildings or casks) are shown and discussed in correlation to cask stresses which are to be expected. (author)

Safety analysis of casks under extreme impact conditions

International Nuclear Information System (INIS)

Wieser, G.; Qiao Linan; Voelzke, H.; Wolff, D.; Droste, B.

2004-01-01

The determination of the inherent safety of casks also under extreme impact conditions has been of increasing interest since the terrorist attacks from 11th September 2001. For nearly three decades BAM has been investigating cask safety under severe accident conditions like drop tests from more than 9 m onto different targets and without impact limiters as well as artificially damaged prototype casks. One of the most critical scenarios for a cask is the centric impact of a dynamic load onto the lid seal system. This can be caused e.g. by direct aircraft crash or its engine as well as by an impact due to the collapse of a building e.g. a nuclear facility storage hall. In this context BAM is developing methods to calculate the deformation of cask components and - with respect to leak tightness - relative displacements between the metallic seals and their counterparts. This paper presents reflections on modelling of cask structures for Finite Element analyses and discusses calculated results of stresses and deformations. Another important aspect is the behaviour of a cask under a lateral impact by aircraft and fragments of a building. Examples of the kinetic reaction (cask acceleration due to the fragments, subsequent contact with neighbouring structures like ground, buildings or casks) are shown and discussed in correlation to cask stresses which are to be expected

Normal and Extreme Wind Conditions for Power at Coastal Locations in China.

Science.gov (United States)

Gao, Meng; Ning, Jicai; Wu, Xiaoqing

2015-01-01

In this paper, the normal and extreme wind conditions for power at 12 coastal locations along China's coastline were investigated. For this purpose, the daily meteorological data measured at the standard 10-m height above ground for periods of 40-62 years are statistically analyzed. The East Asian Monsoon that affects almost China's entire coastal region is considered as the leading factor determining wind energy resources. For most stations, the mean wind speed is higher in winter and lower in summer. Meanwhile, the wind direction analysis indicates that the prevalent winds in summer are southerly, while those in winter are northerly. The air densities at different coastal locations differ significantly, resulting in the difference in wind power density. The Weibull and lognormal distributions are applied to fit the yearly wind speeds. The lognormal distribution performs better than the Weibull distribution at 8 coastal stations according to two judgement criteria, the Kolmogorov-Smirnov test and absolute error (AE). Regarding the annual maximum extreme wind speed, the generalized extreme value (GEV) distribution performs better than the commonly-used Gumbel distribution. At these southeastern coastal locations, strong winds usually occur in typhoon season. These 4 coastal provinces, that is, Guangdong, Fujian, Hainan, and Zhejiang, which have abundant wind resources, are also prone to typhoon disasters.

Online sequential condition prediction method of natural circulation systems based on EOS-ELM and phase space reconstruction

International Nuclear Information System (INIS)

Chen, Hanying; Gao, Puzhen; Tan, Sichao; Tang, Jiguo; Yuan, Hongsheng

2017-01-01

Highlights: •An online condition prediction method for natural circulation systems in NPP was proposed based on EOS-ELM. •The proposed online prediction method was validated using experimental data. •The training speed of the proposed method is significantly fast. •The proposed method can achieve good accuracy in wide parameter range. -- Abstract: Natural circulation design is widely used in the passive safety systems of advanced nuclear power reactors. The irregular and chaotic flow oscillations are often observed in boiling natural circulation systems so it is difficult for operators to monitor and predict the condition of these systems. An online condition forecasting method for natural circulation system is proposed in this study as an assisting technique for plant operators. The proposed prediction approach was developed based on Ensemble of Online Sequential Extreme Learning Machine (EOS-ELM) and phase space reconstruction. Online Sequential Extreme Learning Machine (OS-ELM) is an online sequential learning neural network algorithm and EOS-ELM is the ensemble method of it. The proposed condition prediction method can be initiated by a small chunk of monitoring data and it can be updated by newly arrived data at very fast speed during the online prediction. Simulation experiments were conducted on the data of two natural circulation loops to validate the performance of the proposed method. The simulation results show that the proposed predication model can successfully recognize different types of flow oscillations and accurately forecast the trend of monitored plant variables. The influence of the number of hidden nodes and neural network inputs on prediction performance was studied and the proposed model can achieve good accuracy in a wide parameter range. Moreover, the comparison results show that the proposed condition prediction method has much faster online learning speed and better prediction accuracy than conventional neural network model.

Extreme wildfire events are linked to global-change-type droughts in the northern Mediterranean

Science.gov (United States)

Ruffault, Julien; Curt, Thomas; Martin-StPaul, Nicolas K.; Moron, Vincent; Trigo, Ricardo M.

2018-03-01

Increasing drought conditions under global warming are expected to alter the frequency and distribution of large and high-intensity wildfires. However, our understanding of the impact of increasing drought on extreme wildfires events remains incomplete. Here, we analyzed the weather conditions associated with the extreme wildfires events that occurred in Mediterranean France during the exceptionally dry summers of 2003 and 2016. We identified that these fires were related to two distinct shifts in the fire weather space towards fire weather conditions that had not been explored before and resulting from specific interactions between different types of drought and different fire weather types. In 2016, a long-lasting press drought intensified wind-driven fires. In 2003, a hot drought combining a heat wave with a press drought intensified heat-induced fires. Our findings highlight that increasing drought conditions projected by climate change scenarios might affect the dryness of fuel compartments and lead to a higher frequency of extremes wildfires events.

Desert Cyanobacteria under simulated space and Martian conditions

Science.gov (United States)

Billi, D.; Ghelardini, P.; Onofri, S.; Cockell, C. S.; Rabbow, E.; Horneck, G.

2008-09-01

The environment in space and on planets such as Mars, can be lethal to living organisms and high levels of tolerance to desiccation, cold and radiation are needed for survival: rock-inhabiting cyanobacteria belonging to the genus Chroococcidiopsis can fulfil these requirements [1]. These cyanobacteria constantly appear in the most extreme and dry habitats on Earth, including the McMurdo Dry Valleys (Antarctica) and the Atacama Desert (Chile), which are considered the closest terrestrial analogs of two Mars environmental extremes: cold and aridity. In their natural environment, these cyanobacteria occupy the last refuges for life inside porous rocks or at the stone-soil interfaces, where they survive in a dry, dormant state for prolonged periods. How desert strains of Chroococcidiopsis can dry without dying is only partially understood, even though experimental evidences support the existence of an interplay between mechanisms to avoid (or limit) DNA damage and repair it: i) desert strains of Chroococcidiopsis mend genome fragmentation induced by ionizing radiation [2]; ii) desiccation-survivors protect their genome from complete fragmentation; iii) in the dry state they show a survival to an unattenuated Martian UV flux greater than that of Bacillus subtilis spores [3], and even though they die following atmospheric entry after having orbited the Earth for 16 days [4], they survive to simulated shock pressures up to 10 GPa [5]. Recently additional experiments were carried out at the German Aerospace Center (DLR) of Cologne (Germany) in order to identify suitable biomarkers to investigate the survival of Chroococcidiopsis cells present in lichen-dominated communities, in view of their direct and long term space exposition on the International Space Station (ISS) in the framework of the LIchens and Fungi Experiments (LIFE, EXPOSEEuTEF, ESA). Multilayers of dried cells of strains CCMEE 134 (Beacon Valley, Antarctica), and CCMEE 123 (costal desert, Chile ), shielded by

Space- and ground-based particle physics meet at CERN

CERN Multimedia

CERN Bulletin

2012-01-01

The fourth international conference on Particle and Fundamental Physics in Space (SpacePart12) will take place at CERN from 5 to 7 November. The conference will bring together scientists working on particle and fundamental physics in space and on ground, as well as space policy makers from around the world.   One hundred years after Victor Hess discovered cosmic rays using hot air balloons, the experimental study of particle and fundamental physics is still being pursued today with extremely sophisticated techniques: on the ground, with state-of-the-art accelerators like the LHC; and in space, with powerful observatories that probe, with amazing accuracy, the various forms of cosmic radiation, charged and neutral, which are messengers of the most extreme conditions of matter and energy. SpacePart12 will be the opportunity for participants to exchange views on the progress of space-related science and technology programmes in the field of particle and fundamental physics in space. SpacePar...

Influence of a range of extreme environmental factors on tripartite lichen Peltigera aphthosa thallus viability

Science.gov (United States)

Irina, Insarova; Dyakov, Max; Ptushenko, Vasiliy; Shtaer, Oksana

Lichens are symbiotic organisms consisting of at least two genetic different partners: a heterotrophic fungus (mycobiont) and a phototrophic alga or cyanobacterium (photobiont). Lichens are ubiquitous at global scale. These symbiotic organisms represent the dominant type of “vegetation” at 8 - 10% of land (Larson, 1987). Abiotic stress’ resistance is notable for lichens among all eukaryotes. Lichens are often called “extremophiles” for their ability to acclimate the most severe environmental conditions. These features allow regarding lichens as a group of organisms which is potentially able to keep viability under open space conditions and to survive within Mars-like atmosphere types. The research presented was carried out in the network of spacecraft Bion-1 experiments involving the investigation of physiological and ultrastructural changes in biological objects survivable under open space conditions. Similar researches were already conducted on bipartite lichen species. The most attention was paid to the influence of UV and other space radiation types on lichen viability in those works. Thus we have taken tripartite lichen Peltigera aphthosa as a main research object and temperature fluctuations from extremely high to extremely low values in accordance to solar and umbral orbit sides - for the main extreme environmental factors. These factors were the less studied in previous works. During the research the influence of incubation under anaerobic conditions, multi-time effects of high and low temperatures and their interchange on respiratory metabolism, photosynthetic apparatus condition and the ultrastructure of P. aphthosa thalli was assessed. The data obtained demonstrate that activity either mycobiont or photobiont in tripartite lichen Peltigera aphthosa keep near unchanged under influence of all stress factors explored on dry thalli.

The role of extreme orbits in the global organization of periodic regions in parameter space for one dimensional maps

Science.gov (United States)

da Costa, Diogo Ricardo; Hansen, Matheus; Guarise, Gustavo; Medrano-T, Rene O.; Leonel, Edson D.

2016-04-01

We show that extreme orbits, trajectories that connect local maximum and minimum values of one dimensional maps, play a major role in the parameter space of dissipative systems dictating the organization for the windows of periodicity, hence producing sets of shrimp-like structures. Here we solve three fundamental problems regarding the distribution of these sets and give: (i) their precise localization in the parameter space, even for sets of very high periods; (ii) their local and global distributions along cascades; and (iii) the association of these cascades to complicate sets of periodicity. The extreme orbits are proved to be a powerful indicator to investigate the organization of windows of periodicity in parameter planes. As applications of the theory, we obtain some results for the circle map and perturbed logistic map. The formalism presented here can be extended to many other different nonlinear and dissipative systems.

Establishment and performance of an experimental green roof under extreme climatic conditions

Energy Technology Data Exchange (ETDEWEB)

Klein, Petra M., E-mail: pkklein@ou.edu [School of Meteorology, University of Oklahoma, Norman, OK (United States); Coffman, Reid, E-mail: rcoffma4@kent.edu [College of Architecture and Environmental Design, Kent State University, Kent, OH (United States)

2015-04-15

Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April–October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

Establishment and performance of an experimental green roof under extreme climatic conditions

International Nuclear Information System (INIS)

Klein, Petra M.; Coffman, Reid

2015-01-01

Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April–October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

Development of a Large-Format Science-Grade CMOS Active Pixel Sensor, for Extreme Ultra Violet Spectroscopy and Imaging in Space Science

National Research Council Canada - National Science Library

Waltham, N. R; Prydderch, M; Mapson-Menard, H; Morrissey, Q; Turchetta, R; Pool, P; Harris, A

2005-01-01

We describe our programme to develop a large-format science-grade CMOS active pixel sensor for future space science missions, and in particular an extreme ultra-violet spectrograph for solar physics...

An archaeal tRNA-synthetase complex that enhances aminoacylation under extreme conditions

DEFF Research Database (Denmark)

Godinic-Mikulcic, Vlatka; Jaric, Jelena; Hausmann, Corinne D

2011-01-01

Aminoacyl-tRNA synthetases (aaRSs) play an integral role in protein synthesis, functioning to attach the correct amino acid with its cognate tRNA molecule. AaRSs are known to associate into higher-order multi-aminoacyl-tRNA synthetase complexes (MSC) involved in archaeal and eukaryotic translatio...... of a complex between MtSerRS and MtArgRS provides a means by which methanogenic archaea can optimize an early step in translation under a wide range of extreme environmental conditions....

Studies in the statistical and thermal properties of hadronic matter under some extreme conditions

International Nuclear Information System (INIS)

Chase, K.C.; Mekjian, A.Z.; Bhattacharyya, P.

1997-01-01

The thermal and statistical properties of hadronic matter under some extreme conditions are investigated using an exactly solvable canonical ensemble model. A unified model describing both the fragmentation of nuclei and the thermal properties of hadronic matter is developed. Simple expressions are obtained for quantities such as the hadronic equation of state, specific heat, compressibility, entropy, and excitation energy as a function of temperature and density. These expressions encompass the fermionic aspect of nucleons, such as degeneracy pressure and Fermi energy at low temperatures and the ideal gas laws at high temperatures and low density. Expressions are developed which connect these two extremes with behavior that resembles an ideal Bose gas with its associated Bose condensation. In the thermodynamic limit, an infinite cluster exists below a certain critical condition in a manner similar to the sudden appearance of the infinite cluster in percolation theory. The importance of multiplicity fluctuations is discussed and some recent data from the EOS collaboration on critical point behavior of nuclei can be accounted for using simple expressions obtained from the model. copyright 1997 The American Physical Society

NASA Materials Research for Extreme Conditions

Science.gov (United States)

Sharpe, R. J.; Wright, M. D.

2009-01-01

This Technical Memorandum briefly covers various innovations in materials science and development throughout the course of the American Space program. It details each innovation s discovery and development, explains its significance, and describes the applications of this material either in the time period discovered or today. Topics of research include silazane polymers, solvent-resistant elastomeric polymers (polyurethanes and polyisocyanurates), siloxanes, the Space Shuttle thermal protection system, phenolic-impregnated carbon ablator, and carbon nanotubes. Significance of these developments includes the Space Shuttle, Apollo programs, and the Constellation program.

Life at the limits: peculiar features of lichen symbiosis related to extreme environmental factors

Science.gov (United States)

de Vera, J.-P.; Horneck, G.; Rettberg, P.; Ott, S.

A lichen is a symbiotic association formed by a mycobiont (fungi), a photobiont (algae) and/or a cyanobacteria. The special symbiotic contact and interaction between the bionts in a lichen is a prerequisite for maintainance of viability for each of them during influences by harsh environmental factors. In nature parameters like UV radiation, low or high temperatures and dryness may have a destructive impact on all life functions of an organism. But with lichens the evolution has created a peculiar symbiosis which enables a wide variety of lichen species to colonize habitats where their separate bionts would not be able to survive. The results of our investigations are demonstrating these aspects (de Vera et al. 2003, 2004).We have already investigated the viability of the entire lichen thallus, the embedded spores in lichen apothecia (fruiting bodies) as well as the isolated spores and isolated photobionts after exposure to most extreme conditions caused by simulated space parameters as extreme UV radiation and vacuum. The results presented here focuse on the survival capacity of the isolated photobionts from the two lichen species Xanthoria elegans and Fulgensia bracteata which are not protected by the fungal structure of the lichen thallus. They are based on examinations using a Confocal Laser Scanning Microscopy (CLSM), analysed by modern methods of the Image Tool Program and by culture experiments. In contrast to photobionts embedded in the entire lichen thallus the isolated photobionts are much more sensitve to the extreme conditions of UV radiation and vaccum: while 50 % of the bionts in an entire lichen thallus are able to cope with simulated extreme space conditions (UV-radiation: λ quad ≥ 160nm and vacuum: p = 10-5 Pa) during an exposure time of 2 weeks, the viability of the isolated photobiont cells was already decreasing after 2 hours of exposure. All photobiont cells were inactivated after longer exposure times of about 8 hours. Further more analysis

Stable, Extreme Temperature, High Radiation, Compact. Low Power Clock Oscillator for Space, Geothermal, Down-Hole & other High Reliability Applications, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Efficient and stable clock signal generation requirements at extreme temperatures (-180C to +450C)and radiation (>250 Krad TID) are not met with the current...

Extreme summer temperatures in Iberia: health impacts and associated synoptic conditions

Directory of Open Access Journals (Sweden)

R. García-Herrera

2005-02-01

Full Text Available This paper examines the effect of extreme summer temperatures on daily mortality in two large cities of Iberia: Lisbon (Portugal and Madrid (Spain. Daily mortality and meteorological variables are analysed using the same methodology based on Box-Jenkins models. Results reveal that in both cases there is a triggering effect on mortality when maximum daily temperature exceeds a given threshold (34°C in Lisbon and 36°C in Madrid. The impact of most intense heat events is very similar for both cities, with significant mortality values occurring up to 3 days after the temperature threshold has been surpassed. This impact is measured as the percentual increase of mortality associated to a 1°C increase above the threshold temperature. In this respect, Lisbon shows a higher impact, 31%, as compared with Madrid at 21%. The difference can be attributed to demographic and socio-economic factors. Furthermore, the longer life span of Iberian women is critical to explain why, in both cities, females are more susceptible than males to heat effects, with an almost double mortality impact value. The analysis of Sea Level Pressure (SLP, 500hPa geopotential height and temperature fields reveals that, despite being relatively close to each other, Lisbon and Madrid have relatively different synoptic circulation anomalies associated with their respective extreme summer temperature days. The SLP field reveals higher anomalies for Lisbon, but extending over a smaller area. Extreme values in Madrid seem to require a more western location of the Azores High, embracing a greater area over Europe, even if it is not as deep as for Lisbon. The origin of the hot and dry air masses that usually lead to extreme heat days in both cities is located in Northern Africa. However, while Madrid maxima require wind blowing directly from the south, transporting heat from Southern Spain and Northern Africa, Lisbon maxima occur under more easterly conditions, when Northern African air

Extreme summer temperatures in Iberia: health impacts and associated synoptic conditions

Directory of Open Access Journals (Sweden)

R. García-Herrera

2005-02-01

Full Text Available This paper examines the effect of extreme summer temperatures on daily mortality in two large cities of Iberia: Lisbon (Portugal and Madrid (Spain. Daily mortality and meteorological variables are analysed using the same methodology based on Box-Jenkins models. Results reveal that in both cases there is a triggering effect on mortality when maximum daily temperature exceeds a given threshold (34°C in Lisbon and 36°C in Madrid. The impact of most intense heat events is very similar for both cities, with significant mortality values occurring up to 3 days after the temperature threshold has been surpassed. This impact is measured as the percentual increase of mortality associated to a 1°C increase above the threshold temperature. In this respect, Lisbon shows a higher impact, 31%, as compared with Madrid at 21%. The difference can be attributed to demographic and socio-economic factors. Furthermore, the longer life span of Iberian women is critical to explain why, in both cities, females are more susceptible than males to heat effects, with an almost double mortality impact value.

The analysis of Sea Level Pressure (SLP, 500hPa geopotential height and temperature fields reveals that, despite being relatively close to each other, Lisbon and Madrid have relatively different synoptic circulation anomalies associated with their respective extreme summer temperature days. The SLP field reveals higher anomalies for Lisbon, but extending over a smaller area. Extreme values in Madrid seem to require a more western location of the Azores High, embracing a greater area over Europe, even if it is not as deep as for Lisbon. The origin of the hot and dry air masses that usually lead to extreme heat days in both cities is located in Northern Africa. However, while Madrid maxima require wind blowing directly from the south, transporting heat from Southern Spain and Northern Africa, Lisbon maxima occur under more easterly

Solar chimney: A sustainable approach for ventilation and building space conditioning

Directory of Open Access Journals (Sweden)

Lal, S.,

2013-03-01

Full Text Available The residential and commercial buildings demand increase with rapidly growing population. It leads to the vertical growth of the buildings and needs proper ventilation and day-lighting. The natural air ventilation system is not significantly works in conventional structure, so fans and air conditioners are mandatory to meet the proper ventilation and space conditioning. Globally building sector consumed largest energy and utmost consumed in heating, ventilation and space conditioning. This load can be reduced by application of solar chimney and integrated approaches in buildings for heating, ventilation and space conditioning. It is a sustainable approach for these applications in buildings. The authors are reviewed the concept, various method of evaluation, modelings and performance of solar chimney variables, applications and integrated approaches.

The space shuttle program from challenge to achievement: Space exploration rolling on tires

Science.gov (United States)

Felder, G. L.

1985-01-01

The Space Shuttle Transportation System is the first space program to employ the pneumatic tire as a part of space exploration. For aircraft tires, this program establishes new expectations as to what constitutes acceptable performance within a set of tough environmental and operational conditions. Tire design, stresses the usual low weight, high load, high speed, and excellent air retention features but at extremes well outside industry standards. Tires will continue to be an integral part of the Shuttle's landing phase in the immediate future since they afford a unique combination of directional control, braking traction, flotation and shock absorption not available by other systems.

Studies on gene expressions analyses for Arabidopsis thaliana plants stimulated by space flight condition

Science.gov (United States)

Lu, Jinying; Liu, Min; Pan, Yi; Li, Huasheng

We carried out whole-genome microarray to screen the transcript profile of Arabidopsis thaliana seedlings after three treatment: space microgravity condition( Seedlings grown in microgravity state of space flight of SIMBOX on Shenzhou-8), 1g centrifugal force in space(Seedlings grown in 1g centrifugal force state of space flight of SIMBOX on Shenzhou-8) and ground control. The result of microarray analysis is as followed: There were 368 genes significantly differentially expressed in space microgravity condition compared with that in 1g centrifuge space condition. Space radiation caused 246 genes significantly differentially expressed between seedlings in 1g centrifuge space condition and ground control. Space conditions (including microgravity and radiation) caused 621 genes significantly differentially expressed between seedlings in space microgravity condition and ground control. Microgravity and radiation as a single factor can cause plant gene expression change, but two factors synergism can produce some new effects on plant gene expression. The function of differential expression genes were analyst by bioinformatics, and we found the expression of genes related with stress were more different, such as the dehydration of protein (dehydrin Xero2) expression is up-regulated 57 times; low-temperature-induced protein expression is up-regulated in 49 times; heat shock protein expression is up-regulated 20 times; transcription factor DREB2A expression increase 25 times; protein phosphatase 2C expression is up-regulated 14 times; transcription factor NAM-like protein expression is up-regulated 13 times; cell wall metabolism related genes (xyloglucan, endo-1, 4-beta-D-glucanase) expression is down-regulated in 15 times. The results provide scientific data for the mechanism of space mutation.

Moessbauer spectroscopy in space

Energy Technology Data Exchange (ETDEWEB)

Klingelhoefer, G [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Held, P [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Teucher, R [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Schlichting, F [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Foh, J [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik; Kankeleit, E [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik

1995-03-01

Nearly 40 years after the discovery of the Moessbauer effect for the first time a Moessbauer spectrometer will leave our planet to explore in situ the surface of another solar system body: the red planet Mars [1]. We are currently developing a miniaturized Moessbauer spectrometer (MIMOS) which is part of the scientific payload of the Russian Mars96 mission, to be launched within the next 2-4 years [2,3]. To fulfill the requirements for a space mission to the planet Mars, all parts of the spectrometer had to be extremely miniaturized and ruggedized to withstand the space flight and Mars environmental conditions. The relevant parts (e.g. drive, detector system, electronics etc.) will be described in more detail and its characteristics compared to standard systems. Because of this new development there now is a growing interest to include a Moessbauer (MB) instrument in future space missions to other solar system bodies as for instance Venus, the terrestrial Moon, and a comet nucleus. Because of extremely different environmental conditions (e.g. nearly zero gravity on the surface of a comet nucleus, high pressure and temperature on the surface of Venus, etc.) different instrument designs and concepts are required for different missions. We will present some ideas for various types of missions, as well as the motivation for using Moessbauer spectroscopy in these cases. (orig.)

Proceedings of the first symposium on science of hadrons under extreme conditions

Energy Technology Data Exchange (ETDEWEB)

Chiba, Satoshi; Maruyama, Toshiki [eds.

1999-08-01

The first symposium on Science of Hadrons under Extreme Conditions, organized by the Research Group for Hadron Science, Advanced Science Research Center, was held at Tokai Research Establishment of JAERI on March 11 and 12, 1999. The symposium was devoted for discussions and presentations of research results in wide variety of fields such as observation of X-ray pulsars, theoretical studies of nuclear matter, nuclear structure, low- and high-energy nuclear reactions and QCD. Thirty seven papers on these topics presented at the symposium are indexed individually. (J.P.N.)

Extreme Wave-Induced Oscillation in Paradip Port Under the Resonance Conditions

Science.gov (United States)

Kumar, Prashant; Gulshan

2017-12-01

A mathematical model is constructed to analyze the long wave-induced oscillation in Paradip Port, Odisha, India under the resonance conditions to avert any extreme wave hazards. Boundary element method (BEM) with corner contribution is utilized to solve the Helmholtz equation under the partial reflection boundary conditions. Furthermore, convergence analysis is also performed for the boundary element scheme with uniform and non-uniform discretization of the boundary. The numerical scheme is also validated with analytic approximation and existing studies based on harbor resonance. Then, the amplification factor is estimated at six key record stations in the Paradip Port with multidirectional incident waves and resonance modes are also estimated at the boundary of the port. Ocean surface wave field is predicted in the interior of Paradip Port for the different directional incident wave at various resonance modes. Moreover, the safe locations in the port have been identified for loading and unloading of moored ship with different resonance modes and directional incident waves.

Extreme groundwater levels caused by extreme weather conditions - the highest ever measured groundwater levels in Middle Germany and their management

Science.gov (United States)

Reinstorf, F.; Kramer, S.; Koch, T.; Pfützner, B.

2017-12-01

Extreme weather conditions during the years 2009 - 2011 in combination with changes in the regional water management led to maximum groundwater levels in large areas of Germany in 2011. This resulted in extensive water logging, with problems especially in urban areas near rivers, where water logging produced huge problems for buildings and infrastructure. The acute situation still exists in many areas and requires the development of solution concepts. Taken the example of the Elbe-Saale-Region in the Federal State of Saxony-Anhalt, were a pilot research project was carried out, the analytical situation, the development of a management tool and the implementation of a groundwater management concept are shown. The central tool is a coupled water budget - groundwater flow model. In combination with sophisticated multi-scale parameter estimation, a high-resolution groundwater level simulation was carried out. A decision support process with an intensive stakeholder interaction combined with high-resolution simulations enables the development of a management concept for extreme groundwater situations in consideration of sustainable and environmentally sound solutions mainly on the base of passive measures.

Influence of Extreme Storage Conditions on Extra Virgin Olive Oil Parameters: Traceability Study

Directory of Open Access Journals (Sweden)

Alfredo Escudero

2016-01-01

Full Text Available This study reflects the effect of extreme storage conditions on several extra virgin olive oil (EVOO varieties (arbequina, hojiblanca, and picual. The conditions were simulated in the laboratory, by means of heating treatments in stove at different temperatures (40 and 60°C and times (two and three weeks. The aim is the evaluation of the deterioration of the quality parameters and minority components, which are responsible for the nutritional and therapeutic properties (fatty acids, polyphenols, pigments, and tocopherols, and organoleptic qualities. The quality criteria and limits used in this work are according to International Olive Council. The results contribute to the control of the traSceability for the commercialization of the EVOO.

Habitability in Extreme Conditions

Science.gov (United States)

de Lobkowicz, Ysaline; de Crombrugghe, Guerric; Le Maire, Victor; Jago, Alban; Denies, Jonathan; van Vynckt, Delphine; Reydams, Marc; Mertens, Alexandre

A manned space mission could be perfectly prepared in terms of sciences and technologies, but without a good habitat, a place where the needs of the crew are respected, this isolation and confinement can turn into a nightmare. There is the limitation of engineering: it is more than important to take care about architecture, when human lives are part of the experiment. The goal of the research is the analysis of the hard life of isolation and confinement in Mars' hostile environment and how architecture is a way to improve it. The objective is to place the human in the middle of the analysis. What does a person really need? Therefore Maslow's idea, the pyramid of primary needs, gives us the hierarchy to follow: first survival, food and beverage, then sleep, and only then protection, social activities and work. [1] No more luxury. If all these aspects are respected, a human is able to survive, like it did since so many years. The idea is that each of these main activities has to be related to a different type of space, to provide variability in this close environment. For example, work and relaxing areas have to be separated; a human being needs time for himself, without concentration. A workspace and a relaxing area have a different typology, different colours and lighting, dimensions, furniture. This has also to be respected in a spacecraft. For this research, different sources are used, mainly in the psychological aspect, which is the most important. [2] Therefore questionnaires, interviews, diaries of past expeditions are full of treasures. We do not have to search too far: on earth; polar expeditions, submarines, military camps, etc., give a lot of information. Some very realistic simulations, as on the Mars Desert Research Station (MDRS), will also be used as material: a good analysis of the defaults and well-organized part of the station can conduct to important conclusions. [3] A found analysis and a well-designed habitat are considerable keys for the success

Exertional Rhabdomyolysis after an Extreme Conditioning Competition: A Case Report

Directory of Open Access Journals (Sweden)

Ramires Alsamir Tibana

2018-04-01

Full Text Available This case report describes an instance of exercise-induced rhabdomyolysis caused by an extreme conditioning program (ECP competition. A 35-year-old female presented with abdominal pain and soreness, which began one day after she completed two days of ECPcompetition composed of five workouts. Three days after competition, creatine kinase (CK was 77,590 U/L accompanied by myalgia and abnormal liver function tests, while renal function was normal and this resulted in a diagnosis of rhabdomyolysis. A follow-up examination revealed that her serum level of CK was still elevated to 3034 U/L on day 10 and 1257 U/L on day 25 following the ECP competition. The subject reported myalgia even up to 25 days after the ECP competition. Exertional rhabdomyolysis can be observed in ECP athletes following competition and highlights a dangerous condition, which may be increasing in recent years due to the massive expansion of ECP popularity and a growing number of competitions. Future research should investigate the causes of rhabdomyolysis that occur as a result of ECP, especially training methods and/or tasks developed specifically for these competitions.

A new technique for observationally derived boundary conditions for space weather

Science.gov (United States)

Pagano, Paolo; Mackay, Duncan Hendry; Yeates, Anthony Robinson

2018-04-01

Context. In recent years, space weather research has focused on developing modelling techniques to predict the arrival time and properties of coronal mass ejections (CMEs) at the Earth. The aim of this paper is to propose a new modelling technique suitable for the next generation of Space Weather predictive tools that is both efficient and accurate. The aim of the new approach is to provide interplanetary space weather forecasting models with accurate time dependent boundary conditions of erupting magnetic flux ropes in the upper solar corona. Methods: To produce boundary conditions, we couple two different modelling techniques, MHD simulations and a quasi-static non-potential evolution model. Both are applied on a spatial domain that covers the entire solar surface, although they extend over a different radial distance. The non-potential model uses a time series of observed synoptic magnetograms to drive the non-potential quasi-static evolution of the coronal magnetic field. This allows us to follow the formation and loss of equilibrium of magnetic flux ropes. Following this a MHD simulation captures the dynamic evolution of the erupting flux rope, when it is ejected into interplanetary space. Results.The present paper focuses on the MHD simulations that follow the ejection of magnetic flux ropes to 4 R⊙. We first propose a technique for specifying the pre-eruptive plasma properties in the corona. Next, time dependent MHD simulations describe the ejection of two magnetic flux ropes, that produce time dependent boundary conditions for the magnetic field and plasma at 4 R⊙ that in future may be applied to interplanetary space weather prediction models. Conclusions: In the present paper, we show that the dual use of quasi-static non-potential magnetic field simulations and full time dependent MHD simulations can produce realistic inhomogeneous boundary conditions for space weather forecasting tools. Before a fully operational model can be produced there are a

Extremal surface barriers

International Nuclear Information System (INIS)

Engelhardt, Netta; Wall, Aron C.

2014-01-01

We present a generic condition for Lorentzian manifolds to have a barrier that limits the reach of boundary-anchored extremal surfaces of arbitrary dimension. We show that any surface with nonpositive extrinsic curvature is a barrier, in the sense that extremal surfaces cannot be continuously deformed past it. Furthermore, the outermost barrier surface has nonnegative extrinsic curvature. Under certain conditions, we show that the existence of trapped surfaces implies a barrier, and conversely. In the context of AdS/CFT, these barriers imply that it is impossible to reconstruct the entire bulk using extremal surfaces. We comment on the implications for the firewall controversy

Power conditioning for space nuclear reactor systems

Science.gov (United States)

Berman, Baruch

1987-01-01

This paper addresses the power conditioning subsystem for both Stirling and Brayton conversion of space nuclear reactor systems. Included are the requirements summary, trade results related to subsystem implementation, subsystem description, voltage level versus weight, efficiency and operational integrity, components selection, and shielding considerations. The discussion is supported by pertinent circuit and block diagrams. Summary conclusions and recommendations derived from the above studies are included.

Extreme hydrothermal conditions at an active plate-bounding fault

Science.gov (United States)

Sutherland, Rupert; Townend, John; Toy, Virginia; Upton, Phaedra; Coussens, Jamie; Allen, Michael; Baratin, Laura-May; Barth, Nicolas; Becroft, Leeza; Boese, Carolin; Boles, Austin; Boulton, Carolyn; Broderick, Neil G. R.; Janku-Capova, Lucie; Carpenter, Brett M.; Célérier, Bernard; Chamberlain, Calum; Cooper, Alan; Coutts, Ashley; Cox, Simon; Craw, Lisa; Doan, Mai-Linh; Eccles, Jennifer; Faulkner, Dan; Grieve, Jason; Grochowski, Julia; Gulley, Anton; Hartog, Arthur; Howarth, Jamie; Jacobs, Katrina; Jeppson, Tamara; Kato, Naoki; Keys, Steven; Kirilova, Martina; Kometani, Yusuke; Langridge, Rob; Lin, Weiren; Little, Timothy; Lukacs, Adrienn; Mallyon, Deirdre; Mariani, Elisabetta; Massiot, Cécile; Mathewson, Loren; Melosh, Ben; Menzies, Catriona; Moore, Jo; Morales, Luiz; Morgan, Chance; Mori, Hiroshi; Niemeijer, Andre; Nishikawa, Osamu; Prior, David; Sauer, Katrina; Savage, Martha; Schleicher, Anja; Schmitt, Douglas R.; Shigematsu, Norio; Taylor-Offord, Sam; Teagle, Damon; Tobin, Harold; Valdez, Robert; Weaver, Konrad; Wiersberg, Thomas; Williams, Jack; Woodman, Nick; Zimmer, Martin

2017-06-01

Temperature and fluid pressure conditions control rock deformation and mineralization on geological faults, and hence the distribution of earthquakes. Typical intraplate continental crust has hydrostatic fluid pressure and a near-surface thermal gradient of 31 ± 15 degrees Celsius per kilometre. At temperatures above 300-450 degrees Celsius, usually found at depths greater than 10-15 kilometres, the intra-crystalline plasticity of quartz and feldspar relieves stress by aseismic creep and earthquakes are infrequent. Hydrothermal conditions control the stability of mineral phases and hence frictional-mechanical processes associated with earthquake rupture cycles, but there are few temperature and fluid pressure data from active plate-bounding faults. Here we report results from a borehole drilled into the upper part of the Alpine Fault, which is late in its cycle of stress accumulation and expected to rupture in a magnitude 8 earthquake in the coming decades. The borehole (depth 893 metres) revealed a pore fluid pressure gradient exceeding 9 ± 1 per cent above hydrostatic levels and an average geothermal gradient of 125 ± 55 degrees Celsius per kilometre within the hanging wall of the fault. These extreme hydrothermal conditions result from rapid fault movement, which transports rock and heat from depth, and topographically driven fluid movement that concentrates heat into valleys. Shear heating may occur within the fault but is not required to explain our observations. Our data and models show that highly anomalous fluid pressure and temperature gradients in the upper part of the seismogenic zone can be created by positive feedbacks between processes of fault slip, rock fracturing and alteration, and landscape development at plate-bounding faults.

Extreme hydrothermal conditions at an active plate-bounding fault.

Science.gov (United States)

Sutherland, Rupert; Townend, John; Toy, Virginia; Upton, Phaedra; Coussens, Jamie; Allen, Michael; Baratin, Laura-May; Barth, Nicolas; Becroft, Leeza; Boese, Carolin; Boles, Austin; Boulton, Carolyn; Broderick, Neil G R; Janku-Capova, Lucie; Carpenter, Brett M; Célérier, Bernard; Chamberlain, Calum; Cooper, Alan; Coutts, Ashley; Cox, Simon; Craw, Lisa; Doan, Mai-Linh; Eccles, Jennifer; Faulkner, Dan; Grieve, Jason; Grochowski, Julia; Gulley, Anton; Hartog, Arthur; Howarth, Jamie; Jacobs, Katrina; Jeppson, Tamara; Kato, Naoki; Keys, Steven; Kirilova, Martina; Kometani, Yusuke; Langridge, Rob; Lin, Weiren; Little, Timothy; Lukacs, Adrienn; Mallyon, Deirdre; Mariani, Elisabetta; Massiot, Cécile; Mathewson, Loren; Melosh, Ben; Menzies, Catriona; Moore, Jo; Morales, Luiz; Morgan, Chance; Mori, Hiroshi; Niemeijer, Andre; Nishikawa, Osamu; Prior, David; Sauer, Katrina; Savage, Martha; Schleicher, Anja; Schmitt, Douglas R; Shigematsu, Norio; Taylor-Offord, Sam; Teagle, Damon; Tobin, Harold; Valdez, Robert; Weaver, Konrad; Wiersberg, Thomas; Williams, Jack; Woodman, Nick; Zimmer, Martin

2017-06-01

Temperature and fluid pressure conditions control rock deformation and mineralization on geological faults, and hence the distribution of earthquakes. Typical intraplate continental crust has hydrostatic fluid pressure and a near-surface thermal gradient of 31 ± 15 degrees Celsius per kilometre. At temperatures above 300-450 degrees Celsius, usually found at depths greater than 10-15 kilometres, the intra-crystalline plasticity of quartz and feldspar relieves stress by aseismic creep and earthquakes are infrequent. Hydrothermal conditions control the stability of mineral phases and hence frictional-mechanical processes associated with earthquake rupture cycles, but there are few temperature and fluid pressure data from active plate-bounding faults. Here we report results from a borehole drilled into the upper part of the Alpine Fault, which is late in its cycle of stress accumulation and expected to rupture in a magnitude 8 earthquake in the coming decades. The borehole (depth 893 metres) revealed a pore fluid pressure gradient exceeding 9 ± 1 per cent above hydrostatic levels and an average geothermal gradient of 125 ± 55 degrees Celsius per kilometre within the hanging wall of the fault. These extreme hydrothermal conditions result from rapid fault movement, which transports rock and heat from depth, and topographically driven fluid movement that concentrates heat into valleys. Shear heating may occur within the fault but is not required to explain our observations. Our data and models show that highly anomalous fluid pressure and temperature gradients in the upper part of the seismogenic zone can be created by positive feedbacks between processes of fault slip, rock fracturing and alteration, and landscape development at plate-bounding faults.

Identifying climate analogues for precipitation extremes for Denmark based on RCM simulations from the ENSEMBLES database.

Science.gov (United States)

Arnbjerg-Nielsen, K; Funder, S G; Madsen, H

2015-01-01

Climate analogues, also denoted Space-For-Time, may be used to identify regions where the present climatic conditions resemble conditions of a past or future state of another location or region based on robust climate variable statistics in combination with projections of how these statistics change over time. The study focuses on assessing climate analogues for Denmark based on current climate data set (E-OBS) observations as well as the ENSEMBLES database of future climates with the aim of projecting future precipitation extremes. The local present precipitation extremes are assessed by means of intensity-duration-frequency curves for urban drainage design for the relevant locations being France, the Netherlands, Belgium, Germany, the United Kingdom, and Denmark. Based on this approach projected increases of extreme precipitation by 2100 of 9 and 21% are expected for 2 and 10 year return periods, respectively. The results should be interpreted with caution as the best region to represent future conditions for Denmark is the coastal areas of Northern France, for which only little information is available with respect to present precipitation extremes.

Experimental and theoretical study of electronic structure of aluminum in extreme conditions with X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Festa, Floriane

2013-01-01

Matter in extreme conditions belongs to Warm Dense Matter regime which lays between dense plasma regime and condensed matter. This regime is still not well known, indeed it is very complex to generate such plasma in the laboratory to get experimental data and validate models. The goal of this thesis is to study electronic structure of aluminum in extreme conditions with X-ray absorption spectroscopy. Experimentally aluminum has reached high densities and high temperatures, up to now unexplored. An X-ray source has also been generated to probe highly compressed aluminum. Two spectrometers have recorded aluminum absorption spectra and aluminum density and temperature conditions have been deduced thanks to optical diagnostics. Experimental spectra have been compared to ab initio spectra, calculated in the same conditions. The theoretical goal was to validate the calculation method in high densities and high temperatures regime with the study of K-edge absorption modifications. We also used absorption spectra to study the metal-non metal transition which takes place at low density (density ≤ solid density). This transition could be study with electronic structure modifications of the system. (author) [fr

Probing the local, electronic and magnetic structure of matter under extreme conditions of temperature and pressure

DEFF Research Database (Denmark)

Torchio, R.; Boccato, S.; Cerantola, V.

2016-01-01

In this paper we present recent achievements in the field of investigation of the local, electronic and magnetic structure of the matter under extreme conditions of pressure and temperature. These results were obtained thanks to the coupling of a compact laser heating system to the energy-dispersive...

Heavy fermions and extreme conditions

International Nuclear Information System (INIS)

Cheikine, Ilia

2000-01-01

Three heavy electron systems, CeCu 2 Si 2 , CePd 2 Si 2 and UGe 2 , were investigated by transport, quantum oscillations (CePd 2 Si 2 ) and neutron diffraction (UGe 2 ) measurements. The experiments were performed under extreme conditions of very low temperature, high magnetic field and hydrostatic pressure. In the case of CeCu 2 Si 2 , we followed the evolution of the magnetic A-phase that is found to collapse rapidly under pressure. We found evidence for a relation between the A-phase and the presence of a maximum in the temperature dependence of H c2 . Our analysis showed that at low pressure, the sign of the exchange integral should be negative, thus superconductivity is enhanced by an increase in the paramagnetic susceptibility as in the Jaccarino-Peter effect. The anisotropy of the initial slope of H c2 and therefore that of the effective mass was found to change under pressure. For CePd 2 Si 2 , both the de Haas-van Alphen effect at ambient pressure and the electrical resistivity under pressure were studied. The latter reveals a non-Fermi liquid behavior in the vicinity of the antiferromagnetic quantum critical point, P c ∼ kbar. The analysis of H c2 at P c shows that the superconducting state is well described by a weak coupling, clean limit model with a slightly anisotropic orbital limit and a strongly anisotropic paramagnetic one. UGe 2 is shown to demonstrate the coexistence of ferromagnetism and superconductivity that develops just below the ferromagnetic quantum critical point, P c ∼16 kbar. The measurements of the resistivity under pressure point to a possible existence of another phase boundary and thus another quantum critical point, P x ∼ 12 kbar, within the ferromagnetic state. The P-T phase diagram containing both P c and P x was sketched, and a possible relation between P x and the development of superconductivity was discussed. The temperature dependence of H c2 demonstrates a variety of novel behaviors, which cannot be understood within

A joint analysis of wave and surge conditions for past and present extrem events in the south-western Baltic Sea

Science.gov (United States)

Groll, Nikolaus; Gaslikova, Lidia

2017-04-01

Extreme marine events in the south-western Baltic Sea like the historic storm in 1872 are rare, but have large impacts on human safety and coastal infrastructure. The aforementioned extreme storm event of 1872 and has cost over 250 human lives, left severely damaged infrastructure and caused land loss due to coastal erosion. Recent extreme events also result in drastic impacts to coastal regions. Using results from numerical wave and hydrodynamic model simulations we will present a joint analysis of wave and water level conditions for selected extreme events. For the historic event the numerical models have been forced by reconstructed wind and pressure fields from pressure readings. Simulated atmospheric conditions from reanalysis have been used for the more recent events. The height of the water level due to the possible previous inflow of water masses in the Baltic Sea basin, as well as possible seiches and swell effects have been incorporated in the simulations. We will discuss similarities and differences between the historic and the more recent marine hazard events.

State-Space Geometry, Statistical Fluctuations, and Black Holes in String Theory

Directory of Open Access Journals (Sweden)

Stefano Bellucci

2014-01-01

Full Text Available We study the state-space geometry of various extremal and nonextremal black holes in string theory. From the notion of the intrinsic geometry, we offer a state-space perspective to the black hole vacuum fluctuations. For a given black hole entropy, we explicate the intrinsic geometric meaning of the statistical fluctuations, local and global stability conditions, and long range statistical correlations. We provide a set of physical motivations pertaining to the extremal and nonextremal black holes, namely, the meaning of the chemical geometry and physics of correlation. We illustrate the state-space configurations for general charge extremal black holes. In sequel, we extend our analysis for various possible charge and anticharge nonextremal black holes. From the perspective of statistical fluctuation theory, we offer general remarks, future directions, and open issues towards the intrinsic geometric understanding of the vacuum fluctuations and black holes in string theory.

Quantitative evaluation of the mitochondrial proteomes of Drosophila melanogaster adapted to extreme oxygen conditions.

Directory of Open Access Journals (Sweden)

Songyue Yin

Full Text Available Mitochondria are the primary organelles that consume oxygen and provide energy for cellular activities. To investigate the mitochondrial mechanisms underlying adaptation to extreme oxygen conditions, we generated Drosophila strains that could survive in low- or high-oxygen environments (LOF or HOF, respectively, examined their mitochondria at the ultrastructural level via transmission electron microscopy, studied the activity of their respiratory chain complexes, and quantitatively analyzed the protein abundance responses of the mitochondrial proteomes using Isobaric tag for relative and absolute quantitation (iTRAQ. A total of 718 proteins were identified with high confidence, and 55 and 75 mitochondrial proteins displayed significant differences in abundance in LOF and HOF, respectively, compared with the control flies. Importantly, these differentially expressed mitochondrial proteins are primarily involved in respiration, calcium regulation, the oxidative response, and mitochondrial protein translation. A correlation analysis of the changes in the levels of the mRNAs corresponding to differentially regulated mitochondrial proteins revealed two sets of proteins with different modes of regulation (transcriptional vs. post-transcriptional in both LOF and HOF. We believe that these findings will not only enhance our understanding of the mechanisms underlying adaptation to extreme oxygen conditions in Drosophila but also provide a clue in studying human disease induced by altered oxygen tension in tissues and cells.

On the Performance of Carbon Nanotubes in Extreme Conditions and in the Presence of Microwaves

Science.gov (United States)

2013-01-01

been considered for use as transparent conductors include: transparent conducting oxides (TCOs), intrinsically conducting polymers (ICPs), graphene ...optical transmission properties, but are extremely sensitive to environmental conditions (such as temperature and humidity). Graphene has recently...during the dicing procedure, silver paint was applied to the sample to serve as improvised contact/probe-landing points. Figure 1 shows the CNT thin

The Extreme Male Brain Theory and Gender Role Behaviour in Persons with an Autism Spectrum Condition

Science.gov (United States)

Stauder, J. E. A.; Cornet, L. J. M.; Ponds, R. W. H. M.

2011-01-01

According to the Extreme Male Brain theory persons with autism possess masculinised cognitive traits. In this study masculinisation of gender role behaviour is evaluated in 25 persons with an autism spectrum condition (ASC) and matched controls with gender role behaviour as part of a shortened version of the Minnesota Multiphasic Personality…

Performance of PICS bags under extreme conditions in the sahel zone of Niger.

Science.gov (United States)

Baoua, Ibrahim B; Bakoye, Ousmane; Amadou, Laouali; Murdock, Larry L; Baributsa, Dieudonne

2018-03-01

Experiments in Niger assessed whether extreme environmental conditions including sunlight exposure affect the performance of triple-layer PICS bags in protecting cowpea grain against bruchids. Sets of PICS bags and woven polypropylene bags as controls containing 50 kg of naturally infested cowpea grain were held in the laboratory or outside with sun exposure for four and one-half months. PICS bags held either inside or outside exhibited no significant increase in insect damage and no loss in weight after 4.5 months of storage compared to the initial values. By contrast, woven bags stored inside or outside side by side with PICS bags showed several-fold increases in insects present in or on the grain and significant losses in grain weight. Grain stored inside in PICS bags showed no reduction in germination versus the initial value but there was a small but significant drop in germination of grain in PICS bags held outside (7.6%). Germination rates dropped substantially more in grain stored in woven bags inside (16.1%) and still more in woven bags stored outside (60%). PICS bags held inside and outside retained their ability to maintain internal reduced levels of oxygen and elevated levels of carbon dioxide. Exposure to extreme environmental conditions degraded the external polypropylene outer layer of the PICS triple-layer bag. Even so, the internal layers of polyethylene were more slowly degraded. The effects of exposure to sunlight, temperature and humidity variation within the sealed bags are described.

The Influence of Pre-Conditioning on Space Charge Formation in LDPE

DEFF Research Database (Denmark)

Fleming, Robert J.; Henriksen, Mogens; Holbøll, Joachim T.

1996-01-01

In this paper we present space charge accumulation data for planar low density polyethylene samples subjected to 20 kV/mm dc fields at room temperature. The data were obtained using the laser-induced-pressure-pulse (LIPP) technique. Some of the samples were conditioned by holding them at 40oC in ......C in short-circuit at rotary pump pressure for 48 hr prior to measurement. Such conditioning had no consistent effect on the space charge. The extent of charge injection/extraction at the semicon electrodes appeared to vary considerably between samples....

A statistical methodology for the estimation of extreme wave conditions for offshore renewable applications

DEFF Research Database (Denmark)

Larsén, Xiaoli Guo; Kalogeri, Christina; Galanis, George

2015-01-01

and post-process outputs from a high resolution numerical wave modeling system for extreme wave estimation based on the significant wave height. This approach is demonstrated through the data analysis at a relatively deep water site, FINO 1, as well as a relatively shallow water area, coastal site Horns...... as a characteristic index of extreme wave conditions. The results from the proposed methodology seem to be in a good agreement with the measurements at both the relatively deep, open water and the shallow, coastal water sites, providing a potentially useful tool for offshore renewable energy applications. © 2015...... Rev, which is located in the North Sea, west of Denmark. The post-processing targets at correcting the modeled time series of the significant wave height, in order to match the statistics of the corresponding measurements, including not only the conventional parameters such as the mean and standard...

Dual Axis Controller for Extreme Environments, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The Dual Axis Controller for Extreme Environments (DACEE) addresses a critical need of NASA's future exploration plans to investigate extreme environments within our...

Microbial Response to Spaceflight Conditions

OpenAIRE

Moeller, R.

2017-01-01

Space radiation, including Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE), represents a major hazard for biological systems beyond Earth. Spores of Bacillus subtilis have been shown to be suitable dosimeters for probing extreme terrestrial and extraterrestrial environmental conditions in astrobiological and environmental studies. During dormancy spores are metabolically inactive; thus substantial DNA, protein, tRNA and ribosome damage can accumulate while the spo...

Diamonds on Diamond: structural studies at extreme conditions on the Diamond Light Source.

Science.gov (United States)

McMahon, M I

2015-03-06

Extreme conditions (EC) research investigates how the structures and physical and chemical properties of materials change when subjected to extremes of pressure and temperature. Pressures in excess of one million times atmospheric pressure can be achieved using a diamond anvil cell, and, in combination with high-energy, micro-focused radiation from a third-generation synchrotron such as Diamond, detailed structural information can be obtained using either powder or single-crystal diffraction techniques. Here, I summarize some of the research drivers behind international EC research, and then briefly describe the techniques by which high-quality diffraction data are obtained. I then highlight the breadth of EC research possible on Diamond by summarizing four examples from work conducted on the I15 and I19 beamlines, including a study which resulted in the first research paper from Diamond. Finally, I look to the future, and speculate as to the type of EC research might be conducted at Diamond over the next 10 years. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

A new fluorescent pH probe for extremely acidic conditions

Energy Technology Data Exchange (ETDEWEB)

Xu, Yu [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Taishan College, Shandong University, Jinan 250100 (China); Jiang, Zheng [School of Life Science, Shandong University, Jinan 250100 (China); Taishan College, Shandong University, Jinan 250100 (China); Xiao, Yu [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Taishan College, Shandong University, Jinan 250100 (China); Bi, Fu-Zhen [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Miao, Jun-Ying, E-mail: miaojy@sdu.edu.cn [School of Life Science, Shandong University, Jinan 250100 (China); Zhao, Bao-Xiang, E-mail: bxzhao@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

2014-04-01

A new coumarin-based fluorescent probe can detect highly acidic conditions in both solution and bacteria with high selectivity and sensitivity. Highlights: • A new fluorescence probe for very low pH was synthesized and characterized. • The probe can monitor pH in solution and bacteria. • The two-step protonation of N atoms of the probe leads to fluorescence quenching. Abstract: A novel turn-off fluorescent probe based on coumarin and imidazole moiety for extremely acidic conditions was designed and developed. The probe with pK_a = 2.1 is able to respond to very low pH value (below 3.5) with high sensitivity relying on fluorescence quenching at 460 nm in fluorescence spectra or the ratios of absorbance maximum at 380 nm to that at 450 nm in UV–vis spectra. It can quantitatively detect pH value based on equilibrium equation, pH = pK_a -log[(I_x - I_b)/(I_a - I_x)]. It had very short response time that was less than 1 min, good reversibility and nearly no interference from common metal ions. Moreover, using ¹H NMR analysis and theoretical calculation of molecular orbital, we verified that a two-step protonation process of two N atoms of the probe leaded to photoinduced electron transfer (PET), which was actually the mechanism of the fluorescence quenching phenomenon under strongly acidic conditions. Furthermore, the probe was also applied to imaging strong acidity in bacteria, E.coli and had good effect. This work illustrates that the new probe could be a practical and ideal pH indicator for strongly acidic conditions with good biological significance.

The need of the change of the conceptualisation of hydrologic processes under extreme conditions – taking reference evapotranspiration as an example

Directory of Open Access Journals (Sweden)

S. Liu

2015-06-01

Full Text Available What a hydrological model displays is the relationships between the output and input in daily, monthly, yearly and other temporal scales. In the case of climate change or other environment changes, the input of the hydrological model may show a gradual or abrupt change. There have been numerous documented studies to explore the response of output of the hydrological models to the change of the input with scenario simulation. Most of the studies assumed that the conceptualisation of hydrologic processes will remain, which may be true for the gradual change of the input. However, under extreme conditions the conceptualisation of hydrologic processes may be completely changed. Taking an example of the Allen's formula to calculate crop reference evapotranspiration (ET0 as a simple hydrological model, we analyze the alternation of the extreme in ET0 from 1955 to 2012 at the Chongling Experimental Station located in Hebei Province, China. The relationships between ET0 and the meteorological factors for the average values, minimum (maximum values at daily, monthly and annual scales are revealed. It is found the extreme of the output can follow the extreme of the input better when their relationship is more linear. For non-liner relationship, the extreme of the input cannot at all be reflected from the extreme of the output. Relatively, extreme event at daily scale is harder to be shown than that at monthly scale. The result implicates that a routine model may not be able to catch the response to extreme events and it is even more so as we extrapolate models to higher temperature/CO2 conditions in the future. Some possible choices for the improvements are suggested for predicting hydrological extremes.

Impact of urban WWTP and CSO fluxes on river peak flow extremes under current and future climate conditions.

Science.gov (United States)

Keupers, Ingrid; Willems, Patrick

2013-01-01

The impact of urban water fluxes on the river system outflow of the Grote Nete catchment (Belgium) was studied. First the impact of the Waste Water Treatment Plant (WWTP) and the Combined Sewer Overflow (CSO) outflows on the river system for the current climatic conditions was determined by simulating the urban fluxes as point sources in a detailed, hydrodynamic river model. Comparison was made of the simulation results on peak flow extremes with and without the urban point sources. In a second step, the impact of climate change scenarios on the urban fluxes and the consequent impacts on the river flow extremes were studied. It is shown that the change in the 10-year return period hourly peak flow discharge due to climate change (-14% to +45%) was in the same order of magnitude as the change due to the urban fluxes (+5%) in current climate conditions. Different climate change scenarios do not change the impact of the urban fluxes much except for the climate scenario that involves a strong increase in rainfall extremes in summer. This scenario leads to a strong increase of the impact of the urban fluxes on the river system.

Modulation of Pleurodeles waltl DNA polymerase mu expression by extreme conditions encountered during spaceflight.

Directory of Open Access Journals (Sweden)

Véronique Schenten

Full Text Available DNA polymerase µ is involved in DNA repair, V(DJ recombination and likely somatic hypermutation of immunoglobulin genes. Our previous studies demonstrated that spaceflight conditions affect immunoglobulin gene expression and somatic hypermutation frequency. Consequently, we questioned whether Polμ expression could also be affected. To address this question, we characterized Polμ of the Iberian ribbed newt Pleurodeles waltl and exposed embryos of that species to spaceflight conditions or to environmental modifications corresponding to those encountered in the International Space Station. We noted a robust expression of Polμ mRNA during early ontogenesis and in the testis, suggesting that Polμ is involved in genomic stability. Full-length Polμ transcripts are 8-9 times more abundant in P. waltl than in humans and mice, thereby providing an explanation for the somatic hypermutation predilection of G and C bases in amphibians. Polμ transcription decreases after 10 days of development in space and radiation seem primarily involved in this down-regulation. However, space radiation, alone or in combination with a perturbation of the circadian rhythm, did not affect Polμ protein levels and did not induce protein oxidation, showing the limited impact of radiation encountered during a 10-day stay in the International Space Station.

Necessary and sufficient conditions for big bangs, bounces, crunches, rips, sudden singularities and extremality events

International Nuclear Information System (INIS)

Cattoen, Celine; Visser, Matt

2005-01-01

Until recently, the physically relevant singularities occurring in FRW cosmologies had traditionally been thought to be limited to the 'big bang', and possibly a 'big crunch'. However, over the last few years, the zoo of cosmological singularities considered in the literature has become considerably more extensive, with 'big rips' and 'sudden singularities' added to the mix, as well as renewed interest in nonsingular cosmological events such as 'bounces' and 'turnarounds'. In this paper we present an extensive catalogue of such cosmological milestones, both at the kinematical and dynamical level. First, using generalized power series, purely kinematical definitions of these cosmological events are provided in terms of the behaviour of the scale factor a(t). The notion of a 'scale-factor singularity' is defined, and its relation to curvature singularities (polynomial and differential) is explored. Second, dynamical information is extracted by using the Friedmann equations (without assuming even the existence of any equation of state) to place constraints on whether or not the classical energy conditions are satisfied at the cosmological milestones. We use these considerations to derive necessary and sufficient conditions for the existence of cosmological milestones such as bangs, bounces, crunches, rips, sudden singularities and extremality events. Since the classification is extremely general and, modulo certain technical assumptions, is complete, the corresponding results are to a high degree model independent: in particular, we provide a characterization of the class of bangs, crunches and sudden singularities for which the dominant energy condition is satisfied

Forecasting of flowrate under rolling motion flow instability condition based on on-line sequential extreme learning machine

International Nuclear Information System (INIS)

Chen Hanying; Gao Puzhen; Tan Sichao; Tang Jiguo; Hou Xiaofan; Xu Huiqiang; Wu Xiangcheng

2015-01-01

The coupling of multiple thermal-hydraulic parameters can result in complex flow instability in natural circulation system under rolling motion. A real-time thermal-hydraulic condition prediction is helpful to the operation of systems in such condition. A single hidden layer feedforward neural networks algorithm named extreme learning machine (ELM) is considered as suitable method for this application because of its extremely fast training time, good accuracy and simplicity. However, traditional ELM assumes that all the training data are ready before the training process, while the training data is received sequentially in practical forecasting of flowrate. Therefore, this paper proposes a forecasting method for flowrate under rolling motion based on on-line sequential ELM (OS-ELM), which can learn the data one by one or chunk-by-chunk. The experiment results show that the OS-ELM method can achieve a better forecasting performance than basic ELM method and still keep the advantage of fast training and simplicity. (author)

Single-photon detector operating under extremely high background photon flux conditions

International Nuclear Information System (INIS)

Prochazka, Ivan; Sopko, Bruno; Blazej, Josef

2009-01-01

We are reporting our results in research and development in the field of avalanche semiconductor single-photon detectors and their application. Our goal was a development of a solid-state photon-counting detector capable of high-precision photon arrival time tagging in extremely harsh operating conditions. The background photon flux exceeding 10 9 photons per second hitting the detector active area should not avoid the useful signal detection and recognition on the signal level of units of photons per second. This is background photon flux about two orders of magnitude higher than what the conventional solid-state photon counters accept. The detection timing resolution should be better than 100 ps and the delay stability should be on picosecond level. We have developed and tested the active quenched and gated avalanche structure on silicon providing the required features in connection with the K14 detection chips. The detector is capable of gated operation under the conditions of background photon flux of 5x10 9 photons per second. The operational detector tolerates long term exposures to the input photon flux exceeding 10 15 photons (>1 mW) per second without damage.

Volumes of conditioned bipartite state spaces

International Nuclear Information System (INIS)

Milz, Simon; Strunz, Walter T

2015-01-01

We analyze the metric properties of conditioned quantum state spaces M η (n×m) . These spaces are the convex sets of nm×nm density matrices that, when partially traced over m degrees of freedom, respectively yield the given n × n density matrix η. For the case n = 2, the volume of M η (2×m) equipped with the Hilbert–Schmidt measure can be conjectured to be a simple polynomial of the radius of η in the Bloch-ball. Remarkably, for m=2,3 we find numerically that the probability p sep (2×m) (η) to find a separable state in M η (2×m) is independent of η (except for η pure). For m>3, the same holds for p PosPart (2×m) (η), the probability to find a state with a positive partial transpose in M η (2×m) . These results are proven analytically for the case of the family of 4 × 4 X-states, and thoroughly numerically investigated for the general case. The important implications of these findings for the clarification of open problems in quantum theory are pointed out and discussed. (paper)

Classically integrable boundary conditions for symmetric-space sigma models

International Nuclear Information System (INIS)

MacKay, N.J.; Young, C.A.S.

2004-01-01

We investigate boundary conditions for the non-linear sigma model on the compact symmetric space G/H. The Poisson brackets and the classical local conserved charges necessary for integrability are preserved by boundary conditions which correspond to involutions which commute with the involution defining H. Applied to SO(3)/SO(2), the non-linear sigma model on S 2 , these yield the great circles as boundary submanifolds. Applied to GxG/G, they reproduce known results for the principal chiral model

Condition Based Maintenance of Space Exploration Vehicles Using Structural Health Monitoring, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Acellent Technologies proposes to develop an autonomous and automated diagnostic system for condition based maintenance (CBM) of safety critical structures for space...

An alternative phase-space distribution to sample initial conditions for classical dynamics simulations

International Nuclear Information System (INIS)

Garcia-Vela, A.

2002-01-01

A new quantum-type phase-space distribution is proposed in order to sample initial conditions for classical trajectory simulations. The phase-space distribution is obtained as the modulus of a quantum phase-space state of the system, defined as the direct product of the coordinate and momentum representations of the quantum initial state. The distribution is tested by sampling initial conditions which reproduce the initial state of the Ar-HCl cluster prepared by ultraviolet excitation, and by simulating the photodissociation dynamics by classical trajectories. The results are compared with those of a wave packet calculation, and with a classical simulation using an initial phase-space distribution recently suggested. A better agreement is found between the classical and the quantum predictions with the present phase-space distribution, as compared with the previous one. This improvement is attributed to the fact that the phase-space distribution propagated classically in this work resembles more closely the shape of the wave packet propagated quantum mechanically

Branching geodesics in normed spaces

International Nuclear Information System (INIS)

Ivanov, A O; Tuzhilin, A A

2002-01-01

We study branching extremals of length functionals on normed spaces. This is a natural generalization of the Steiner problem in normed spaces. We obtain criteria for a network to be extremal under deformations that preserve the topology of networks as well as under deformations with splitting. We discuss the connection between locally shortest networks and extremal networks. In the important particular case of the Manhattan plane, we get a criterion for a locally shortest network to be extremal

The myoglobin of Emperor penguin (Aptenodytes forsteri): amino acid sequence and functional adaptation to extreme conditions.

Science.gov (United States)

Tamburrini, M; Romano, M; Giardina, B; di Prisco, G

1999-02-01

In the framework of a study on molecular adaptations of the oxygen-transport and storage systems to extreme conditions in Antarctic marine organisms, we have investigated the structure/function relationship in Emperor penguin (Aptenodytes forsteri) myoglobin, in search of correlation with the bird life style. In contrast with previous reports, the revised amino acid sequence contains one additional residue and 15 differences. The oxygen-binding parameters seem well adapted to the diving behaviour of the penguin and to the environmental conditions of the Antarctic habitat. Addition of lactate has no major effect on myoglobin oxygenation over a large temperature range. Therefore, metabolic acidosis does not impair myoglobin function under conditions of prolonged physical effort, such as diving.

Extreme Ionizing-Radiation-Resistant Bacterium

Science.gov (United States)

Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

2013-01-01

There is a growing concern that desiccation and extreme radiation-resistant, non-spore-forming microorganisms associated with spacecraft surfaces can withstand space environmental conditions and subsequent proliferation on another solar body. Such forward contamination would jeopardize future life detection or sample return technologies. The prime focus of NASA s planetary protection efforts is the development of strategies for inactivating resistance-bearing micro-organisms. Eradi cation techniques can be designed to target resistance-conferring microbial populations by first identifying and understanding their physiologic and biochemical capabilities that confers its elevated tolerance (as is being studied in Deinococcus phoenicis, as a result of this description). Furthermore, hospitals, food, and government agencies frequently use biological indicators to ensure the efficacy of a wide range of radiation-based sterilization processes. Due to their resistance to a variety of perturbations, the nonspore forming D. phoenicis may be a more appropriate biological indicator than those currently in use. The high flux of cosmic rays during space travel and onto the unshielded surface of Mars poses a significant hazard to the survival of microbial life. Thus, radiation-resistant microorganisms are of particular concern that can survive extreme radiation, desiccation, and low temperatures experienced during space travel. Spore-forming bacteria, a common inhabitant of spacecraft assembly facilities, are known to tolerate these extreme conditions. Since the Viking era, spores have been utilized to assess the degree and level of microbiological contamination on spacecraft and their associated spacecraft assembly facilities. Members of the non-sporeforming bacterial community such as Deinococcus radiodurans can survive acute exposures to ionizing radiation (5 kGy), ultraviolet light (1 kJ/m2), and desiccation (years). These resistive phenotypes of Deinococcus enhance the

(When and where) Do extreme climate events trigger extreme ecosystem responses? - Development and initial results of a holistic analysis framework

Science.gov (United States)

Hauber, Eva K.; Donner, Reik V.

2015-04-01

In the context of ongoing climate change, extremes are likely to increase in magnitude and frequency. One of the most important consequences of these changes is that the associated ecological risks and impacts are potentially rising as well. In order to better anticipate and understand these impacts, it therefore becomes more and more crucial to understand the general connection between climate extremes and the response and functionality of ecosystems. Among other region of the world, Europe presents an excellent test case for studies concerning the interaction between climate and biosphere, since it lies in the transition region between cold polar and warm tropical air masses and thus covers a great variety of different climatic zones and associated terrestrial ecosystems. The large temperature differences across the continent make this region particularly interesting for investigating the effects of climate change on biosphere-climate interactions. However, previously used methods for defining an extreme event typically disregard the necessity of taking seasonality as well as seasonal variance appropriately into account. Furthermore, most studies have focused on the impacts of individual extreme events instead of considering a whole inventory of extremes with their respective spatio-temporal extents. In order to overcome the aforementioned research gaps, this work introduces a new approach to studying climate-biosphere interactions associated with extreme events, which comprises three consecutive steps: (1) Since Europe exhibits climatic conditions characterized by marked seasonality, a novel method is developed to define extreme events taking into account the seasonality in all quantiles of the probability distribution of the respective variable of interest. This is achieved by considering kernel density estimates individually for each observation date during the year, including the properly weighted information from adjacent dates. By this procedure, we obtain

Power conditioning for large dc motors for space flight applications

Science.gov (United States)

Veatch, Martin S.; Anderson, Paul M.; Eason, Douglas J.; Landis, David M.

1988-01-01

The design and performance of a prototype power-conditioning system for use with large brushless dc motors on NASA space missions are discussed in detail and illustrated with extensive diagrams, drawings, and graphs. The 5-kW 8-phase parallel module evaluated here would be suitable for use in the Space Shuttle Orbiter cargo bay. A current-balancing magnetic assembly with low distributed inductance permits high-speed current switching from a low-voltage bus as well as current balancing between parallel MOSFETs.

Does red noise increase or decrease extinction risk? Single extreme events versus series of unfavorable conditions.

Science.gov (United States)

Schwager, Monika; Johst, Karin; Jeltsch, Florian

2006-06-01

Recent theoretical studies have shown contrasting effects of temporal correlation of environmental fluctuations (red noise) on the risk of population extinction. It is still debated whether and under which conditions red noise increases or decreases extinction risk compared with uncorrelated (white) noise. Here, we explain the opposing effects by introducing two features of red noise time series. On the one hand, positive autocorrelation increases the probability of series of poor environmental conditions, implying increasing extinction risk. On the other hand, for a given time period, the probability of at least one extremely bad year ("catastrophe") is reduced compared with white noise, implying decreasing extinction risk. Which of these two features determines extinction risk depends on the strength of environmental fluctuations and the sensitivity of population dynamics to these fluctuations. If extreme (catastrophic) events can occur (strong noise) or sensitivity is high (overcompensatory density dependence), then temporal correlation decreases extinction risk; otherwise, it increases it. Thus, our results provide a simple explanation for the contrasting previous findings and are a crucial step toward a general understanding of the effect of noise color on extinction risk.

Experimental verification of free-space singular boundary conditions in an invisibility cloak

International Nuclear Information System (INIS)

Wu, Qiannan; Gao, Fei; Song, Zhengyong; Lin, Xiao; Zhang, Youming; Zhang, Baile; Chen, Huanyang

2016-01-01

A major issue in invisibility cloaking, which caused intense mathematical discussions in the past few years but still remains physically elusive, is the plausible singular boundary conditions associated with the singular metamaterials at the inner boundary of an invisibility cloak. The perfect cloaking phenomenon, as originally proposed by Pendry et al for electromagnetic waves, cannot be treated as physical before a realistic inner boundary of a cloak is demonstrated. Although a recent demonstration has been done in a waveguide environment, the exotic singular boundary conditions should apply to a general environment as in free space. Here we fabricate a metamaterial surface that exhibits the singular boundary conditions and demonstrate its performance in free space. Particularly, the phase information of waves reflected from this metamaterial surface is explicitly measured, confirming the singular responses of boundary conditions for an invisibility cloak. (paper)

Experimental verification of free-space singular boundary conditions in an invisibility cloak

Science.gov (United States)

Wu, Qiannan; Gao, Fei; Song, Zhengyong; Lin, Xiao; Zhang, Youming; Chen, Huanyang; Zhang, Baile

2016-04-01

A major issue in invisibility cloaking, which caused intense mathematical discussions in the past few years but still remains physically elusive, is the plausible singular boundary conditions associated with the singular metamaterials at the inner boundary of an invisibility cloak. The perfect cloaking phenomenon, as originally proposed by Pendry et al for electromagnetic waves, cannot be treated as physical before a realistic inner boundary of a cloak is demonstrated. Although a recent demonstration has been done in a waveguide environment, the exotic singular boundary conditions should apply to a general environment as in free space. Here we fabricate a metamaterial surface that exhibits the singular boundary conditions and demonstrate its performance in free space. Particularly, the phase information of waves reflected from this metamaterial surface is explicitly measured, confirming the singular responses of boundary conditions for an invisibility cloak.

Continuous Spatial Process Models for Spatial Extreme Values

KAUST Repository

Sang, Huiyan

2010-01-28

We propose a hierarchical modeling approach for explaining a collection of point-referenced extreme values. In particular, annual maxima over space and time are assumed to follow generalized extreme value (GEV) distributions, with parameters μ, σ, and ξ specified in the latent stage to reflect underlying spatio-temporal structure. The novelty here is that we relax the conditionally independence assumption in the first stage of the hierarchial model, an assumption which has been adopted in previous work. This assumption implies that realizations of the the surface of spatial maxima will be everywhere discontinuous. For many phenomena including, e. g., temperature and precipitation, this behavior is inappropriate. Instead, we offer a spatial process model for extreme values that provides mean square continuous realizations, where the behavior of the surface is driven by the spatial dependence which is unexplained under the latent spatio-temporal specification for the GEV parameters. In this sense, the first stage smoothing is viewed as fine scale or short range smoothing while the larger scale smoothing will be captured in the second stage of the modeling. In addition, as would be desired, we are able to implement spatial interpolation for extreme values based on this model. A simulation study and a study on actual annual maximum rainfall for a region in South Africa are used to illustrate the performance of the model. © 2009 International Biometric Society.

The JEM-EUSO mission to explore the extreme Universe

International Nuclear Information System (INIS)

Kajino, Fumiyoshi

2010-01-01

Accommodated on the Japanese Experiment Module (JEM) of the International Space Station (ISS), the Extreme Universe Space Observatory JEM-EUSO will utilize the Earth's atmosphere as a giant detector of the extreme energy cosmic rays; the most energetic particles coming from the Universe. Looking downward the Earth from Space, JEM-EUSO will detect such particles by observing the fluorescence and Cherenkov photons produced during their pass in the atmosphere. The main objective of JEM-EUSO is doing astronomy and astrophysics through the particle channel with extreme energies above several times 10 19 eV with a significant statistics beyond the Greisen-Zatsepin-Kuzmin (GZK) cut-off. Moreover, JEM-EUSO could observe extremely high energy neutrinos. JEM-EUSO has been designed to operate for more than 3 years onboard the ISS orbiting around the Earth every 90 min at an altitude of about 400 km. JAXA has selected JEM-EUSO as one of the mission candidates of the second phase utilization of JEM/EF for the launch in mid 2010s.

Area spectra of near extremal black holes

International Nuclear Information System (INIS)

Chen, Deyou; Yang, Haitang; Zu, Xiaotao

2010-01-01

Motivated by Maggiore's new interpretation of quasinormal modes, we investigate area spectra of a near extremal Schwarzschild-de Sitter black hole and a higher-dimensional near extremal Reissner-Nordstrom-de Sitter black hole. The result shows that the area spectra are equally spaced and irrelevant to the parameters of the black holes. (orig.)

Examining personal values in extreme environment contexts: Revisiting the question of generalizability

Science.gov (United States)

Smith, N.; Sandal, G. M.; Leon, G. R.; Kjærgaard, A.

2017-08-01

Land-based extreme environments (e.g. polar expeditions, Antarctic research stations, confinement chambers) have often been used as analog settings for spaceflight. These settings share similarities with the conditions experienced during space missions, including confinement, isolation and limited possibilities for evacuation. To determine the utility of analog settings for understanding human spaceflight, researchers have examined the extent to which the individual characteristics (e.g., personality) of people operating in extreme environments can be generalized across contexts (Sandal, 2000) [1]. Building on previous work, and utilising new and pre-existing data, the present study examined the extent to which personal value motives could be generalized across extreme environments. Four populations were assessed; mountaineers (N =59), military personnel (N = 25), Antarctic over-winterers (N = 21) and Mars simulation participants (N = 12). All participants completed the Portrait Values Questionnaire (PVQ; Schwartz; 2) capturing information on 10 personal values. Rank scores suggest that all groups identified Self-direction, Stimulation, Universalism and Benevolence as important values and acknowledged Power and Tradition as being low priorities. Results from difference testing suggest the extreme environment groups were most comparable on Self-direction, Stimulation, Benevolence, Tradition and Security. There were significant between-group differences on five of the ten values. Overall, findings pinpointed specific values that may be important for functioning in challenging environments. However, the differences that emerged on certain values highlight the importance of considering the specific population when comparing results across extreme settings. We recommend that further research examine the impact of personal value motives on indicators of adjustment, group working, and performance. Information from such studies could then be used to aid selection and

Regional metamorphism at extreme conditions: Implications for orogeny at convergent plate margins

Science.gov (United States)

Zheng, Yong-Fei; Chen, Ren-Xu

2017-09-01

Regional metamorphism at extreme conditions refers either to Alpine-type metamorphism at low geothermal gradients of geothermal gradients of >30 °C/km. Extreme pressures refer to those above the polymorphic transition of quartz to coesite, so that ultrahigh-pressure (UHP) eclogite-facies metamorphism occurs at mantle depths of >80 km. Extreme temperatures refer to those higher than 900 °C at crustal depths of ≤80 km, so that ultrahigh-temperature (UHT) granulite-facies metamorphism occurs at medium to high pressures. While crustal subduction at the low geothermal gradients results in blueschist-eclogite facies series without arc volcanism, heating of the thinned orogenic lithosphere brings about the high geothermal gradients for amphibolite-granulite facies series with abundant magmatism. Therefore, UHP metamorphic rocks result from cold lithospheric subduction to the mantle depths, whereas UHT metamorphic rocks are produced by hot underplating of the asthenospheric mantle at the crustal depths. Active continental rifting is developed on the thinned lithosphere in response to asthenospheric upwelling, and this tectonism is suggested as a feasible mechanism for regional granulite-facies metamorphism, with the maximum temperature depending on the extent to which the mantle lithosphere is thinned prior to the rifting. While lithospheric compression is associated with subduction metamorphism in accretionary and collisional orogens, the thinned orogenic lithosphere undergoes extension due to the asthenospheric upwelling to result in orogen-parallel rifting metamorphism and magmatism. Thus, the rifting metamorphism provides a complement to the subduction metamorphism and its operation marks the asthenospheric heating of the orogenic lithosphere. Because of the partial melting and melt extraction of the lower continental crust, contemporaneous granite-migmatite-granulite associations may serve as a petrological indicator of rifting orogeny that is superimposed on

Extremal vectors and rectifiability | Enflo | Quaestiones Mathematicae

African Journals Online (AJOL)

Extremal vectors and rectifiability. ... The concept of extremal vectors of a linear operator with a dense range but not onto on a Hilbert space was introduced by P. Enflo in 1996 as a new approach to study invariant subspaces ... We show that in general curves that map numbers to backward minimal vectors are not rectifiable.

Technical note: Space-time analysis of rainfall extremes in Italy: clues from a reconciled dataset

Science.gov (United States)

Libertino, Andrea; Ganora, Daniele; Claps, Pierluigi

2018-05-01

Like other Mediterranean areas, Italy is prone to the development of events with significant rainfall intensity, lasting for several hours. The main triggering mechanisms of these events are quite well known, but the aim of developing rainstorm hazard maps compatible with their actual probability of occurrence is still far from being reached. A systematic frequency analysis of these occasional highly intense events would require a complete countrywide dataset of sub-daily rainfall records, but this kind of information was still lacking for the Italian territory. In this work several sources of data are gathered, for assembling the first comprehensive and updated dataset of extreme rainfall of short duration in Italy. The resulting dataset, referred to as the Italian Rainfall Extreme Dataset (I-RED), includes the annual maximum rainfalls recorded in 1 to 24 consecutive hours from more than 4500 stations across the country, spanning the period between 1916 and 2014. A detailed description of the spatial and temporal coverage of the I-RED is presented, together with an exploratory statistical analysis aimed at providing preliminary information on the climatology of extreme rainfall at the national scale. Due to some legal restrictions, the database can be provided only under certain conditions. Taking into account the potentialities emerging from the analysis, a description of the ongoing and planned future work activities on the database is provided.

Hemoglobin system of Sparus aurata: Changes in fishes farmed under extreme conditions

International Nuclear Information System (INIS)

Campo, Salvatore; Nastasi, Giancarlo; D'Ascola, Angela; Campo, Giuseppe M.; Avenoso, Angela; Traina, Paola; Calatroni, Alberto; Burrascano, Emanuele; Ferlazzo, Alida; Lupidi, Giulio; Gabbianelli, Rosita; Falcioni, Giancarlo

2008-01-01

In order to gain more knowledge on the stress responses of gilhead seabream (Sparus aurata) under extreme conditions, this study investigated the functional properties of the hemoglobin system and globin gene expression under hypoxia and low salinity. The oxygen affinity for the two hemoglobin components present inside the S. aurata erythrocyte was practically identical as was the influence of protons and organic phosphates (Root effect). The quantification of S. aurata hemoglobin fractions performed by HPLC and the data on gene expression of globin chains assayed by PCR indicate that under hypoxia and low salinity there is a change in the ratio between the two different hemoglobin components. The result indicating that the distinct hemoglobins present in S. aurata erythrocyte have almost identical functional properties, does not explain the adaptive response (expression change) following exposure of the animal to hypoxia or low salinity on the basis of their function as oxygen transporter. We hypothesize that other parallel biological functions that the hemoglobin molecule is known to display within the erythrocyte are involved in adaptive molecular mechanisms. The autoxidation-reduction cycle of hemoglobin could be involved in the response to particular living conditions

Minimal and Maximal Operator Space Structures on Banach Spaces

OpenAIRE

P., Vinod Kumar; Balasubramani, M. S.

2014-01-01

Given a Banach space $X$, there are many operator space structures possible on $X$, which all have $X$ as their first matrix level. Blecher and Paulsen identified two extreme operator space structures on $X$, namely $Min(X)$ and $Max(X)$ which represents respectively, the smallest and the largest operator space structures admissible on $X$. In this note, we consider the subspace and the quotient space structure of minimal and maximal operator spaces.

Matter in Extreme Conditions Instrument - Conceptual Design Report

Energy Technology Data Exchange (ETDEWEB)

Boyce, R.F.; Boyce, R.M.; Haller, G.; Hastings, J.B.; Hays, G.; Lee, H.J.; /SLAC; Lee, R.W.; /LLNL, Livermore; Nagler, B.; /Rutherford; Scharfenstein, M.; Marsh, D.; White, W.E.; /SLAC

2009-12-09

The SLAC National Accelerator Laboratory (SLAC), in collaboration with Argonne National Laboratory (ANL), Lawrence Livermore National Laboratory (LLNL), and the University of California at Los Angeles (UCLA), is constructing a Free-Electron Laser (FEL) research facility. The FEL has already met its performance goals in the wavelength range 1.5 nm - 0.15 nm. This facility, the Linac Coherent Light Source (LCLS), utilizes the SLAC 2-Mile Linear Accelerator (linac) and will produce sub-picosecond pulses of short wavelength X-rays with very high peak brightness and almost complete transverse coherence. The final one-third of the SLAC linac is used as the source of electrons for the LCLS. The high energy electrons are transported across the SLAC Research Yard, into a tunnel which houses a long undulator. In passing through the undulator, the electrons are bunched by the force of their own synchrotron radiation and produce an intense, monochromatic, spatially coherent beam of X-rays. By varying the electron energy, the FEL X-ray wavelength is tunable from 1.5 nm to 0.15 nm. The LCLS includes two experimental halls as well as X-ray optics and infrastructure necessary to create a facility that can be developed for research in a variety of disciplines such as atomic physics, materials science, plasma physics and biosciences. This Conceptual Design Report, the authors believe, confirms the feasibility of designing and constructing an X-ray instrument in order to exploit the unique scientific capability of LCLS by creating extreme conditions and study the behavior of plasma under those controlled conditions. This instrument will address the Office of Science, Fusion Energy Sciences, mission objective related to study of Plasma and Warm Dense Matter as described in the report titled LCLS, the First Experiments, prepared by the LCLS Scientific Advisory Committee (SAC) in September 2000. The technical objective of the LCLS Matter in Extreme Conditions (MEC) Instrument project is

Establishment and performance of an experimental green roof under extreme climatic conditions.

Science.gov (United States)

Klein, Petra M; Coffman, Reid

2015-04-15

Green roofs alter the surface energy balance and can help in mitigating urban heat islands. However, the cooling of green roofs due to evapotranspiration strongly depends on the climatic conditions, and vegetation type and density. In the Southern Central Plains of the United States, extreme weather events, such as high winds, heat waves and drought conditions pose challenges for successful implementation of green roofs, and likely alter their standard performance. The National Weather Center Experimental Green Roof, an interdisciplinary research site established in 2010 in Norman, OK, aimed to investigate the ecological performance and surface energy balance of green roof systems. Starting in May 2010, 26 months of vegetation studies were conducted and the radiation balance, air temperature, relative humidity, and buoyancy fluxes were monitored at two meteorological stations during April-October 2011. The establishment of a vegetative community trended towards prairie plant dominance. High mortality of succulents and low germination of grasses and herbaceous plants contributed to low vegetative coverage. In this condition succulent diversity declined. Bouteloua gracilis and Delosperma cooperi showed typological dominance in harsh climatic conditions, while Sedum species experienced high mortality. The plant community diversified through volunteers such as Euphorbia maculate and Portulaca maculate. Net radiation measured at a green-roof meteorological station was higher than at a control station over the original, light-colored roofing material. These findings indicate that the albedo of the green roof was lower than the albedo of the original roofing material. The low vegetative coverage during the heat and drought conditions in 2011, which resulted in the dark substrate used in the green roof containers being exposed, likely contributed to the low albedo values. Nevertheless, air temperatures and buoyancy fluxes were often lower over the green roof indicating

Estimation of absorbed dose for poor shields under conditions of near-earth space flight

International Nuclear Information System (INIS)

Konyukov, V.V.; Krajnyukov, V.I.; Trufanov, A.I.

1995-01-01

Estimation of electron absorbed dose in materials of a space vehicle for poor shields under conditions of near-earth space flight is carried out. Impact of power and angular distribution of incidence electrons and radiation scattering processes under conditions of complex geometry and multitude of materials of flight vehicle elements and nodes is studied through simulator model by example of isolating layer of aluminium-polyethylene assembly. 3 refs.; 2 figs

Directional analysis of extreme winds under mixed climate conditions

CSIR Research Space (South Africa)

Kruger, A

2013-07-01

Full Text Available Directional statistics provide design engineers with the opportunity to realise considerable cost savings, but these are not yet provided for in the South African standard for wind loading. The development of the directional statistics of extreme...

Identification of Extreme Events Under Climate Change Conditions Over Europe and The Northwest-atlantic Region: Spatial Patterns and Time Series Characteristics

Science.gov (United States)

Leckebusch, G.; Ulbrich, U.; Speth, P.

In the context of climate change and the resulting possible impacts on socio-economic conditions for human activities it seems that due to a changed occurrence of extreme events more severe consequences have to be expected than from changes in the mean climate. These extreme events like floods, excessive heats and droughts or windstorms possess impacts on human social and economic life in different categories such as forestry, agriculture, energy use, tourism and the reinsurance business. Reinsurances are affected by nearly 70% of all insured damages over Europe in the case of wind- storms. Especially the December 1999 French windstorms caused damages about 10 billion. A new EU-founded project (MICE = Modelling the Impact of Climate Ex- tremes) will focus on these impacts caused by changed occurrences of extreme events over Europe. Based upon the output of general circulation models as well as regional climate models, investigations are carried out with regard to time series characteristics as well as the spatial patterns of extremes under climate changed conditions. After the definition of specific thresholds for climate extremes, in this talk we will focus on the results of the analysis for the different data sets (HadCM3 and CGCMII GCM's and RCM's, re-analyses, observations) with regard to windstorm events. At first the results of model outputs are validated against re-analyses and observations. Especially a comparison of the stormtrack (2.5 to 8 day bandpass filtered 500 hPa geopotential height), cyclone track, cyclone frequency and intensity is presented. Highly relevant to damages is the extreme wind near the ground level, so the 10 m wind speed will be investigated additionally. of special interest to possible impacts is the changed spatial occurrence of windspeed maxima under 2xCO2-induced climate change.

The Quantum Space Phase Transitions for Particles and Force Fields

Directory of Open Access Journals (Sweden)

Chung D.-Y.

2006-07-01

Full Text Available We introduce a phenomenological formalism in which the space structure is treated in terms of attachment space and detachment space. Attachment space attaches to an object, while detachment space detaches from the object. The combination of these spaces results in three quantum space phases: binary partition space, miscible space and binary lattice space. Binary lattice space consists of repetitive units of alternative attachment space and detachment space. In miscible space, attachment space is miscible to detachment space, and there is no separation between attachment space and detachment spaces. In binary partition space, detachment space and attachment space are in two separat continuous regions. The transition from wavefunction to the collapse of wavefuction under interference becomes the quantum space phase transition from binary lattice space to miscible space. At extremely conditions, the gauge boson force field undergoes a quantum space phase transition to a "hedge boson force field", consisting of a "vacuum" core surrounded by a hedge boson shell, like a bubble with boundary.

Assessing the importance of spatio-temporal RCM resolution when estimating sub-daily extreme precipitation under current and future climate conditions

DEFF Research Database (Denmark)

Sunyer Pinya, Maria Antonia; Luchner, J.; Onof, C.

2017-01-01

extreme precipitation over Denmark generated by the regional climate model (RCM) HIRHAM-ECEARTH at different spatial resolutions (8, 12, 25 and 50km), three RCM from the RiskChange project at 8km resolution and three RCMs from ENSEMBLES at 25km resolution at temporal aggregations from 1 to 48h...... are more skewed than the observational dataset, which leads to an overestimation by the higher spatial resolution simulations. Nevertheless, in general, under current conditions RCM simulations at high spatial resolution represent extreme events and high-order moments better. The changes projected...

The problem of defining contemporary right-wing extremism in political theory

Directory of Open Access Journals (Sweden)

Đorić Marija

2016-01-01

Full Text Available The subject matter of research in this paper is theoretical controversy related to the definition of right-wing extremism. Given the fact that extremism is a variable, amorphous and insufficiently researched phenomenon, largely conditioned by time, space, political and cultural differences, there is a great confusion in the field of political science when defining right-wing extremism. The problem of researching right-wing extremism is additionally complicated by various terms that are being used in the contemporary literature as its synonyms, such as right-wing radicalism, neo-Fascism, ultra-radicalism, etc. In order to provide the most valid theoretical determination of right-wing extremism, the author provides a detailed analysis of all the components constituting this phenomenon and examines their causality. In the political praxis, the term extremism is extensively abused, which additionally complicates its determination. Videlicet, politicians often use term 'extremist' in order to discredit their political opponents. While during the French revolution aristocracy saw the bourgeoisie as extremists, the members of the working class later stated that the bourgeoisie were extremists. The problem lies in the fact that, in politics, extremists are not only the ones who use violence as modus operandi; indeed, it is also used by political opponents who do not belong to the extreme political option. Another aggravating factor in defining right-wing extremism is that many administrative and academic definitions do not make a clear distinction between extremism and related phenomena, such as terrorism, radicalism and populism. Extremism is most often equaled with terrorism, which gives rise to another problem in defining this phenomenon. The relation between extremism and terrorism is the relation of general and specific. Namely, every act of terrorism is concurrently considered to be an act of extremism, but not vice versa, given the fact that

Biofilms and planktonic cells of Deinococcus geothermalis in extreme environments

Science.gov (United States)

Panitz, Corinna; Reitz, Guenther; Rabbow, Elke; Rettberg, Petra; Flemming, Hans-Curt; Wingender, Jost; Froesler, Jan

In addition to the several extreme environments on Earth, Space can be considered as just another exceptional environment with a unique mixture of stress factors comprising UV radiation, vacuum, desiccation, temperature, ionizing radiation and microgravity. Life that processes in these environments can depend on the life forms and their state of living. The question is whether there are different strategies for individual microorganisms compared to communities of the same organisms to cope with the different factors of their surroundings. Comparative studies of the survi-val of these communities called biofilms and planktonic cell samples of Deinococcus geothermalis stand at the focal point of the presented investigations. A biofilm is a structured community of microorganisms that live encapsulated in a matrix of extracellular polymeric substances on a surface. Microorganisms living in a biofilm usually have significantly different properties to cooperate than individually living microorganisms of the same species. An advantage of the biofilm is increased resistance to various chemical and physical effects, while the dense extracellular matrix and the outer layer of the cells protect the interior of the microbial consortium. The space experiment BOSS (Biofilm organisms surfing Space) as part the ESA experimental unit EXPOSE R-2 with a planned launch date in July 2014 will be subsequently mounted on the Russian Svesda module outside the ISS. An international team of scientists coordinated by Dr. P. Rettberg will investigate the hypothesis whether microorganisms organized as biofilm outmatch the same microorganisms exposed individually in the long-term survival of the harsh environmental conditions as they occur in space and on Mars. Another protective function in the samples could be dust par-ticles for instance Mars regolith simulant contained inside the biofilms or mixed with the planktonic cells, as additional shelter especially against the extraterrestrial UV

Thermal convection in a closed cavity in zero-gravity space conditions with stationary magnetic forces

International Nuclear Information System (INIS)

Lyubimova, T; Mailfert, A

2013-01-01

The paper deals with the investigation of thermo-magnetic convection in a paramagnetic liquid subjected to a non-uniform magnetic field in weightlessness conditions. Indeed, in zero-g space conditions such as realized in International Space Station (ISS), or in artificial satellite, or in free-flight space vessels, the classical thermo-gravitational convection in fluid disappears. In any cases, it may be useful to restore the convective thermal exchange inside fluids such as liquid oxygen. In this paper, the restoration of heat exchange by the way of creation of magnetic convection is numerically studied.

A Conditional Fourier-Feynman Transform and Conditional Convolution Product with Change of Scales on a Function Space II

Directory of Open Access Journals (Sweden)

Dong Hyun Cho

2017-01-01

Full Text Available Using a simple formula for conditional expectations over continuous paths, we will evaluate conditional expectations which are types of analytic conditional Fourier-Feynman transforms and conditional convolution products of generalized cylinder functions and the functions in a Banach algebra which is the space of generalized Fourier transforms of the measures on the Borel class of L2[0,T]. We will then investigate their relationships. Particularly, we prove that the conditional transform of the conditional convolution product can be expressed by the product of the conditional transforms of each function. Finally we will establish change of scale formulas for the conditional transforms and the conditional convolution products. In these evaluation formulas and change of scale formulas, we use multivariate normal distributions so that the conditioning function does not contain present positions of the paths.

PREDICTION OF THE EXTREMAL SHAPE FACTOR OF SPHEROIDAL PARTICLES

Directory of Open Access Journals (Sweden)

Daniel Hlubinka

2011-05-01

Full Text Available In the stereological unfolding problem for spheroidal particles the extremal shape factor is predicted. The theory of extreme values has been used to show that extremes of the planar shape factor of particle sections tend to the same limit distribution as extremes of the original shape factor for both the conditional and marginal distribution. Attention is then paid to the extreme shape factor conditioned by the particle size. Normalizing constants are evaluated for a parametric model and the numerical procedure is tested on real data from metallography.

Behavior of ionic conducting IPN actuators in simulated space conditions

Science.gov (United States)

Fannir, Adelyne; Plesse, Cédric; Nguyen, Giao T. M.; Laurent, Elisabeth; Cadiergues, Laurent; Vidal, Frédéric

2016-04-01

The presentation focuses on the performances of flexible all-polymer electroactive actuators under space-hazardous environmental factors in laboratory conditions. These bending actuators are based on high molecular weight nitrile butadiene rubber (NBR), poly(ethylene oxide) (PEO) derivative and poly(3,4-ethylenedioxithiophene) (PEDOT). The electroactive PEDOT is embedded within the PEO/NBR membrane which is subsequently swollen with an ionic liquid as electrolyte. Actuators have been submitted to thermal cycling test between -25 to 60°C under vacuum (2.4 10-8 mbar) and to ionizing Gamma radiations at a level of 210 rad/h during 100 h. Actuators have been characterized before and after space environmental condition ageing. In particular, the viscoelasticity properties and mechanical resistance of the materials have been determined by dynamic mechanical analysis and tensile tests. The evolution of the actuation properties as the strain and the output force have been characterized as well. The long-term vacuuming, the freezing temperature and the Gamma radiations do not affect significantly the thermomechanical properties of conducting IPNs actuators. Only a slight decrease on actuation performances has been observed.

Residual stresses relaxation in surface-hardened half-space under creep conditions

Directory of Open Access Journals (Sweden)

Vladimir P. Radchenko

2015-09-01

Full Text Available We developed the method for solving the problem of residual stresses relaxation in surface-hardened layer of half-space under creep conditions. At the first stage we made the reconstruction of stress-strain state in half-space after plastic surface hardening procedure based on partial information about distribution for one residual stress tensor component experimentally detected. At the second stage using a numerical method we solve the problem of relaxation of self-balanced residual stresses under creep conditions. To solve this problem we introduce the following Cartesian system: x0y plane is aligned with hardened surface of half-space and 0z axis is directed to the depth of hardened layer. We also introduce the hypotheses of plane sections parallel to x0z and y0z planes. Detailed analysis of the problem has been done. Comparison of the calculated data with the corresponding test data was made for plane specimens (rectangular parallelepipeds made of EP742 alloy during T=650°C after the ultrasonic hardening with four hardening modes. We use half-space to model these specimens because penetration's depth of residual stresses is less than specimen general size in two digit exponent. There is enough correspondence of experimental and calculated data. It is shown that there is a decay (in modulus of pressing residual stresses under creep in 1.4–1.6 times.

The extreme blazar AO 0235+164 as seen by extensive ground and space radio observations

Science.gov (United States)

Kutkin, A. M.; Pashchenko, I. N.; Lisakov, M. M.; Voytsik, P. A.; Sokolovsky, K. V.; Kovalev, Y. Y.; Lobanov, A. P.; Ipatov, A. V.; Aller, M. F.; Aller, H. D.; Lahteenmaki, A.; Tornikoski, M.; Gurvits, L. I.

2018-04-01

Clues to the physical conditions in radio cores of blazars come from measurements of brightness temperatures as well as effects produced by intrinsic opacity. We study the properties of the ultra-compact blazar AO 0235+164 with RadioAstron ground-space radio interferometer, multifrequency VLBA, EVN, and single-dish radio observations. We employ visibility modelling and image stacking for deriving structure and kinematics of the source, and use Gaussian process regression to find the relative multiband time delays of the flares. The multifrequency core size and time lags support prevailing synchrotron self-absorption. The intrinsic brightness temperature of the core derived from ground-based very long baseline interferometry (VLBI) is close to the equipartition regime value. In the same time, there is evidence for ultra-compact features of the size of less than 10 μas in the source, which might be responsible for the extreme apparent brightness temperatures of up to 1014 K as measured by RadioAstron. In 2007-2016 the VLBI components in the source at 43 GHz are found predominantly in two directions, suggesting a bend of the outflow from southern to northern direction. The apparent opening angle of the jet seen in the stacked image at 43 GHz is two times wider than that at 15 GHz, indicating a collimation of the flow within the central 1.5 mas. We estimate the Lorentz factor Γ = 14, the Doppler factor δ = 21, and the viewing angle θ = 1.7° of the apparent jet base, derive the gradients of magnetic field strength and electron density in the outflow, and the distance between jet apex and the core at each frequency.

Correlations in condensed matter under extreme conditions a tribute to Renato Pucci on the occasion of his 70th birthday

CERN Document Server

2017-01-01

This book addresses a wide range of topics relating to the properties and behavior of condensed matter under extreme conditions such as intense magnetic and electric fields, high pressures, heat and cold, and mechanical stresses. It is divided into four sections devoted to condensed matter theory, molecular chemistry, theoretical physics, and the philosophy and history of science. The main themes include electronic correlations in material systems under extreme pressure and temperature conditions, surface physics, the transport properties of low-dimensional electronic systems, applications of the density functional theory in molecular systems, and graphene. The book is the outcome of a workshop held at the University of Catania, Italy, in honor of Professor Renato Pucci on the occasion of his 70th birthday. It includes selected invited contributions from collaborators and co-authors of Professor Pucci during his long and successful career, as well as from other distinguished guest authors.

Recent studies of transplutonium compounds: new directions and use of extreme conditions

International Nuclear Information System (INIS)

Peterson, J.R.; Begun, G.M.; Gibson, J.K.

1987-01-01

The number of bulk-phase compounds prepared and characterized for each of the transplutonium (TPu) elements drops off precipitously with increasing atomic number. However, efforts have been made to increase the number of TPu compounds known and also the range of investigative methods applied to their characterization. The results of a worldwide survey to determine the status of the preparation of new TPu compounds and/or the application of new investigative techniques to the study of such compounds in bulk will be presented. The focus will then shift to Oak Ridge projects: extreme conditions of pressure and/or temperature are being used for synthesis and for absorption and raman spectral studies; single crystals of trihalides are being grown for spectral and magnetic studies; new ternary chalcogenide-halide compounds are being characterized; vaporization thermodynamics of TPu compounds are being determined; and attempts to stabilize unusual oxidation states are being carried out

Performance of an SOI Boot-Strapped Full-Bridge MOSFET Driver, Type CHT-FBDR, under Extreme Temperatures

Science.gov (United States)

Patterson, Richard; Hammoud, Ahmad

2009-01-01

Electronic systems designed for use in deep space and planetary exploration missions are expected to encounter extreme temperatures and wide thermal swings. Silicon-based devices are limited in their wide-temperature capability and usually require extra measures, such as cooling or heating mechanisms, to provide adequate ambient temperature for proper operation. Silicon-On-Insulator (SOI) technology, on the other hand, lately has been gaining wide spread use in applications where high temperatures are encountered. Due to their inherent design, SOI-based integrated circuit chips are able to operate at temperatures higher than those of the silicon devices by virtue of reducing leakage currents, eliminating parasitic junctions, and limiting internal heating. In addition, SOI devices provide faster switching, consume less power, and offer improved radiation-tolerance. Very little data, however, exist on the performance of such devices and circuits under cryogenic temperatures. In this work, the performance of an SOI bootstrapped, full-bridge driver integrated circuit was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to establish a baseline on the functionality and to determine suitability of this device for use in space exploration missions under extreme temperature conditions.

Aurorasaurus: Citizen Scientists Experiencing Extremes of Space Weather

Science.gov (United States)

MacDonald, E.; Hall, M.; Tapia, A.

2013-12-01

Aurorasaurus is a new citizen science mapping platform to nowcast the visibility of the Northern Lights for the public in the current solar maximum, the first with social media. As a recently funded NSF INSPIRE program, we have joint goals among three research disciplines: space weather forecasting, the study of human-computer interactions, and informal science education. We will highlight results from the prototype www.aurorasaurus.org and outline future efforts to motivate online participants and crowdsource viable data. Our citizen science effort is unique among space programs as it includes both reporting observations and data analysis activities to engage the broadest participant network possible. In addition, our efforts to improve space weather nowcasting by including real-time mapping of ground truth observers for rare, sporadic events are a first in the field.

The greenhouse effect and extreme weather

International Nuclear Information System (INIS)

Groenaas, Sigbjoern; Kvamstoe, Nils Gunnar

2002-01-01

The article asserts that an anthropogenic global warming is occurring. This greenhouse effect is expected to cause more occurrences of extreme weather. It is extremely difficult, however, to relate specific weather catastrophes to global warming with certainty, since such extreme weather conditions are rare historically. The subject is controversial. The article also discusses the public debate and the risk of floods

Estimation of Radiation Limit from a Huygens' Box under Non-Free-Space Conditions

DEFF Research Database (Denmark)

Franek, Ondrej; Sørensen, Morten; Bonev, Ivan Bonev

2013-01-01

The recently studied Huygens' box method has difficulties when radiation of an electronic module is to be determined under non-free-space conditions, i.e. with an enclosure. We propose an estimate on radiation limit under such conditions based only on the Huygens' box data from free...

The effect of environmental parameters to dust concentration in air-conditioned space

Science.gov (United States)

Ismail, A. M. M.; Manssor, N. A. S.; Nalisa, A.; Yahaya, N.

2017-08-01

Malaysia has a wet and hot climate, therefore most of the spaces are air conditioned. The environment might affect dust concentration inside a space and affect the indoor air quality (IAQ). The main objective of this study is to study the dust concentration collected inside enclosed air-conditioned space. The measurement was done physically at four selected offices and two classrooms using a number of equipment to measure the dust concentration and environmental parameters which are temperature and relative air humidity. It was found that the highest dust concentration produced in office (temperature of 24.7°C, relative humidity of 66.5%) is 0.075 mg/m3, as compared to classroom, the highest dust concentration produced is 0.060 mg/m3 office (temperature of 25.9°C, relative humidity of 64.0%). However, both measurements show that value still within the safety level set by DOSH Malaysia (2005-2010) and ASHRAE 62.2 2016. The office contained higher dust concentration compared to classroom because of frequent movement transpires daily due to the functional of the offices.

Acclimatization to extreme heat

Science.gov (United States)

Warner, M. E.; Ganguly, A. R.; Bhatia, U.

2017-12-01

Heat extremes throughout the globe, as well as in the United States, are expected to increase. These heat extremes have been shown to impact human health, resulting in some of the highest levels of lives lost as compared with similar natural disasters. But in order to inform decision makers and best understand future mortality and morbidity, adaptation and mitigation must be considered. Defined as the ability for individuals or society to change behavior and/or adapt physiologically, acclimatization encompasses the gradual adaptation that occurs over time. Therefore, this research aims to account for acclimatization to extreme heat by using a hybrid methodology that incorporates future air conditioning use and installation patterns with future temperature-related time series data. While previous studies have not accounted for energy usage patterns and market saturation scenarios, we integrate such factors to compare the impact of air conditioning as a tool for acclimatization, with a particular emphasis on mortality within vulnerable communities.

Technology development of protein rich concentrates for nutrition in extreme conditions using soybean and meat by-products.

Science.gov (United States)

Kalenik, Tatiana K; Costa, Rui; Motkina, Elena V; Kosenko, Tamara A; Skripko, Olga V; Kadnikova, Irina A

2017-01-01

There is a need to develop new foods for participants of expeditions in extreme conditions, which must be self-sufficient. These foods should be light to carry, with a long shelf life, tasty and with  high nutrient density. Currently, protein sources are limited mainly to dried and canned meat. In this work, a protein-rich dried concentrate suitable for extreme expeditions was developed using soya, tomato, milk whey and meat by-products. Protein concentrates were developed using minced beef liver and heart, dehydrated and mixed with a soya protein-lycopene coagulate (SPLC) obtained from a solution prepared with germi- nated soybeans and mixed with tomato paste in milk whey, and finally dried. The technological parameters of pressing SPLC and of drying the protein concentrate were optimized using response surface methodology. The optimized technological parameters to prepare the protein concentrates were obtained, with 70:30 being the ideal ratio of minced meat to SPLC. The developed protein concentrates are characterized by a high calorific value of 376 kcal/100 g of dry product, with a water content of 98 g·kg-1, and 641-644 g·kg-1 of proteins. The essential amino acid indices are 100, with minimum essential amino acid content constitut- ing 100-128% of the FAO standard, depending on the raw meat used. These concentrates are also rich in micronutrients such as β-carotene and vitamin C. Analysis of the nutrient content showed that these non-perishable concentrates present a high nutritional value and complement other widely available vegetable concentrates to prepare a two-course meal. The soups and porridges prepared with these concentrates can be classified as functional foods, and comply with army requirements applicable to food products for extreme conditions.

Extreme Conditioning Programs: Potential Benefits and Potential Risks.

Science.gov (United States)

Knapik, Joseph J

2015-01-01

CrossFit, Insanity, Gym Jones, and P90X are examples of extreme conditioning programs (ECPs). ECPs typically involve high-volume and high-intensity physical activities with short rest periods between movements and use of multiple joint exercises. Data on changes in fitness with ECPs are limited to CrossFit investigations that demonstrated improvements in muscle strength, muscular endurance, aerobic fitness, and body composition. However, no study has directly compared CrossFit or other ECPs to other more traditional forms of aerobic and resistance training within the same investigation. These direct comparisons are needed to more adequately evaluate the effectiveness of ECPs. Until these studies emerge, the comparisons with available literature suggest that improvements in CrossFit, in terms of muscular endurance (push-ups, sit-ups), strength, and aerobic capacity, appear to be similar to those seen in more traditional training programs. Investigations of injuries in ECPs are limited to two observational studies that suggest that the overall injury rate is similar to that seen in other exercise programs. Several cases of rhabdomyolysis and cervical carotid artery dissections have been reported during CrossFit training. The symptoms, diagnosis, and treatment of these are reviewed here. Until more data on ECPs emerge, physical training should be aligned with US Army doctrine. If ECPs are included in exercise programs, trainers should (1) have appropriate training certifications, (2) inspect exercise equipment regularly to assure safety, (3) introduce ECPs to new participants, (4) ensure medical clearance of Soldiers with special health problems before participation in ECPs, (4) tailor ECPs to the individual Soldier, (5) adjust rest periods to optimize recovery and reduce fatigue, (6) monitor Soldiers for signs of overtraining, rhabdomyolysis, and other problems, and (7) coordinate exercise programs with other unit training activities to eliminate redundant activities

Automaton Rover for Extreme Environments, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Extreme environments abound in the solar system and include the radiation around Jupiter, high surface temperatures on Mercury and Venus, and hot, high pressure...

Unique Nature of the Quality of Life in the Context of Extreme Climatic, Geographical and Specific Socio-Cultural Living Conditions

Science.gov (United States)

Kulik, Anastasia; Neyaskina, Yuliya; Frizen, Marina; Shiryaeva, Olga; Surikova, Yana

2016-01-01

This article presents the results of a detailed empirical research, aimed at studying the quality of life in the context of extreme climatic, geographical and specific sociocultural living conditions. Our research is based on the methodological approach including social, economical, ecological and psychological characteristics and reflecting…

An Overview of Science Challenges Pertaining to our Understanding of Extreme Geomagnetically Induced Currents. Chapter 8

Science.gov (United States)

Ngwira, Chigomezyo M.; Pulkkinen, Antti A.

2018-01-01

Vulnerability of man-made infrastructure to Earth-directed space weather events is a serious concern for today's technology-dependent society. Space weather-driven geomagnetically induced currents (GICs) can disrupt operation of extended electrically conducting technological systems. The threat of adverse impacts on critical technological infrastructure, like power grids, oil and gas pipelines, and communication networks, has sparked renewed interest in extreme space weather. Because extreme space weather events have low occurrence rate but potentially high impact, this presents a major challenge for our understanding of extreme GIC activity. In this chapter, we discuss some of the key science challenges pertaining to our understanding of extreme events. In addition, we present an overview of GICs including highlights of severe impacts over the last 80 years and recent U.S. Federal actions relevant to this community.

Extreme fire events are related to previous-year surface moisture conditions in permafrost-underlain larch forests of Siberia

International Nuclear Information System (INIS)

Forkel, Matthias; Beer, Christian; Thonicke, Kirsten; Cramer, Wolfgang; Bartalev, Sergey; Schmullius, Christiane

2012-01-01

Wildfires are a natural and important element in the functioning of boreal forests. However, in some years, fires with extreme spread and severity occur. Such severe fires can degrade the forest, affect human values, emit huge amounts of carbon and aerosols and alter the land surface albedo. Usually, wind, slope and dry air conditions have been recognized as factors determining fire spread. Here we identify surface moisture as an additional important driving factor for the evolution of extreme fire events in the Baikal region. An area of 127 000 km 2 burned in this region in 2003, a large part of it in regions underlain by permafrost. Analyses of satellite data for 2002–2009 indicate that previous-summer surface moisture is a better predictor for burned area than precipitation anomalies or fire weather indices for larch forests with continuous permafrost. Our analysis advances the understanding of complex interactions between the atmosphere, vegetation and soil, and how coupled mechanisms can lead to extreme events. These findings emphasize the importance of a mechanistic coupling of soil thermodynamics, hydrology, vegetation functioning, and fire activity in Earth system models for projecting climate change impacts over the next century. (letter)

Comparison and development of advanced dosimetric techniques to be used under extreme climatic conditions

International Nuclear Information System (INIS)

Madhvanath, U.

1975-08-01

The post-irradiation fading characteristics of various dosimeters in function of relative humidity of air during storage were tested in specially set up humidity boxes. The temperature and relative humidity were varied between 5deg-35degC and 40-90%, respectively. Fading was 70% and 80% at 2 and 6 days respectively, for Kodak Type 2 film under 28degC and 76% relative humidity. Under these conditions the corresponding values for NTA emulsions were 30% and 80% respectively. Agfa-Gevaert films proved to be less sensitive and gave 20% and 30%, respectively, for the mentioned intervals. When Kodak Type 2 film was sealed in polythene bags, fading was reduced considerably, to appr. 15% in 4 weeks. Alternate storage of exposed films in humid and dry conditions also reduced fading to the same extent. When NTA emulsions were double-sealed with desiccant inside fading was reduced to 10% in 15 days. CaSO 4 :Dy (DRP and Harshaw) showed only 7% fading in 3 months. LiF TLD-100 was more sensitive, 13% in 2 months. Gamma-irradiated Li-borate has faded up to 30% at extreme climatic conditions in 3 months but thermal neutron irradiated Li-borate was resistant against fading for this period

Structural studies of disordered materials using high-energy x-ray diffraction from ambient to extreme conditions

Energy Technology Data Exchange (ETDEWEB)

Kohara, Shinji [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Itou, Masayoshi [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Suzuya, Kentaro [Japan Atomic Energy Agency (J-PARC/JAEA), Tokai, Naka, Ibaraki 319-1195 (Japan); Inamura, Yasuhiro [Japan Atomic Energy Agency (J-PARC/JAEA), Tokai, Naka, Ibaraki 319-1195 (Japan); Sakurai, Yoshiharu [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Ohishi, Yasuo [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Takata, Masaki [Japan Synchrotron Radiation Research Institute (SPring-8/JASRI), 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2007-12-19

High-energy x-rays from a synchrotron radiation source allow us to obtain high-quality diffraction data for disordered materials from ambient to extreme conditions, which is necessary for revealing the detailed structures of glass, liquid and amorphous materials. We introduced high-energy x-ray diffraction beamlines and a dedicated diffractometer for glass, liquid and amorphous materials at SPring-8 and report the recent developments of ancillary equipment. Furthermore, the structures of liquid and amorphous materials determined from the high-energy x-ray diffraction data obtained at SPring-8 are discussed.

Air-cooled LiBr-water absorption chillers for solar air conditioning in extremely hot weathers

International Nuclear Information System (INIS)

Kim, D.S.; Infante Ferreira, C.A.

2009-01-01

A low temperature-driven absorption cycle is theoretically investigated for the development of an air-cooled LiBr-water absorption chiller to be combined with low-cost flat solar collectors for solar air conditioning in hot and dry regions. The cycle works with dilute LiBr-water solutions so that risk of LiBr crystallization is less than for commercially available water-cooled LiBr-water absorption chillers even in extremely hot ambient conditions. Two-phase heat exchangers in the system were modelled taking account of the heat and mass transfer resistances in falling film flows by applying the film theory in thermal and concentration boundary layers. Both directly and indirectly air-cooled chillers were modelled by properly combining component models and boundary conditions in a matrix system and solved with an algebraic equation solver. Simulation results predict that the chillers would deliver chilled water around 7.0 deg. C with a COP of 0.37 from 90 deg. C hot water under 35 deg. C ambient condition. At 50 deg. C ambient temperature, the chillers retained about 36% of their cooling power at 35 deg. C ambient. Compared with the directly air-cooled chiller, the indirectly air-cooled chiller presented a cooling power performance reduction of about 30%

Kinetics of Materials at Extreme Conditions: Understanding the Time Dependent Approach to Equilibrium at MaRIE

Energy Technology Data Exchange (ETDEWEB)

Kraus, R. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mcnabb, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kumar, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Eggert, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Borg, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Cerreta, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dattelbaum, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fried, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Greeff, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stolken, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-04-21

The National Nuclear Security Agency has recently recognized that a long-term need exists to establish a stronger scientific basis for the assessment and qualification of materials and manufacturing processes for the nuclear stockpile and other national security applications. These materials may have undergone substantial changes with age, or may represent new materials that are being introduced because of difficulties associated with reusing or recreating materials used in original stockpile components. Also, with advancements in manufacturing methods, the NNSA anticipates opportunities for an enhanced range of control over fabricated components, an enhanced pace of materials development, and enhanced functionality. The development of qualification standards for these new materials will require the ability to understand and control material characteristics that affect both mechanical and dynamic performance. A unique aspect for NNSA is that the performance requirements for materials are often set by system hydrodynamics, and these materials must perform in extreme environments and loading conditions. Thus, the scientific motivation is to understand “Matter-Radiation Interactions in Extremes (MaRIE).”

Covered Interest-Rate Parity Revisited: an Extreme Value Copula Analysis

Directory of Open Access Journals (Sweden)

Mikel Ugando-Peñate

2015-11-01

Full Text Available This article studied the covered interest-rate parity (CIP condition under extreme market movements using extreme value theory and extreme value copulas to characterize dependence between extreme interest rate differentials and forward premium. The empirical analysis for the CIP between interest rates for the US dollar and the British pound indicates that there is strong co-movement between interest rate differentials and forward premium at different maturities and in both upper and lower tails. This conclusion would support the existence of the CIP condition under extreme market movements.

Disaster Risks Reduction for Extreme Natural Hazards

Science.gov (United States)

Plag, H.; Jules-Plag, S.

2013-12-01

Mega disasters associated with extreme natural hazards have the potential to escalate the global sustainability crisis and put us close to the boundaries of the safe operating space for humanity. Floods and droughts are major threats that potentially could reach planetary extent, particularly through secondary economic and social impacts. Earthquakes and tsunamis frequently cause disasters that eventually could exceed the immediate coping capacity of the global economy, particularly since we have built mega cities in hazardous areas that are now ready to be harvested by natural hazards. Unfortunately, the more we learn to cope with the relatively frequent hazards (50 to 100 years events), the less we are worried about the low-probability, high-impact events (a few hundred and more years events). As a consequence, threats from the 500 years flood, drought, volcano eruption are not appropriately accounted for in disaster risk reduction (DRR) discussions. Extreme geohazards have occurred regularly throughout the past, but mostly did not cause major disasters because exposure of human assets to hazards was much lower in the past. The most extreme events that occurred during the last 2,000 years would today cause unparalleled damage on a global scale and could worsen the sustainability crisis. Simulation of these extreme hazards under present conditions can help to assess the disaster risk. Recent extreme earthquakes have illustrated the destruction they can inflict, both directly and indirectly through tsunamis. Large volcano eruptions have the potential to impact climate, anthropogenic infrastructure and resource supplies on global scale. During the last 2,000 years several large volcano eruptions occurred, which under today's conditions are associated with extreme disaster risk. The comparison of earthquakes and volcano eruptions indicates that large volcano eruptions are the low-probability geohazards with potentially the highest impact on our civilization

Non-extremal black hole solutions from the c-map

International Nuclear Information System (INIS)

Errington, D.; Mohaupt, T.; Vaughan, O.

2015-01-01

We construct new static, spherically symmetric non-extremal black hole solutions of four-dimensional N=2 supergravity, using a systematic technique based on dimensional reduction over time (the c-map) and the real formulation of special geometry. For a certain class of models we actually obtain the general solution to the full second order equations of motion, whilst for other classes of models, such as those obtainable by dimensional reduction from five dimensions, heterotic tree-level models, and type-II Calabi-Yau compactifications in the large volume limit a partial set of solutions are found. When considering specifically non-extremal black hole solutions we find that regularity conditions reduce the number of integration constants by one half. Such solutions satisfy a unique set of first order equations, which we identify. Several models are investigated in detail, including examples of non-homogeneous spaces such as the quantum deformed STU model. Though we focus on static, spherically symmetric solutions of ungauged supergravity, the method is adaptable to other types of solutions and to gauged supergravity.

Development of a system for simultaneously generating triple extreme conditions for neutron scattering experiments

Energy Technology Data Exchange (ETDEWEB)

Ichimura, Shigeju [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-10-01

We have developed new system available for controlling sample environment during the neutron scattering experiments. The system can simultaneously generate triple extreme conditions of low temperature, high magnetic field and high pressure. The system consists of : (1) a liquid-helium cryostat which enables the sample temperature range of 1.7 K to 200 K, (2) a superconducting magnet providing a vertical field up to 5 Tesla with antisymmetric split-coil geometry for polarized-beam experiments, and (3) a non-magnetic clamping high-pressure cell designed with the aim of generating hydrostatic pressure up to 2.5 Gpa. In the workshop, we will report the outline of the system and some results of performance tests using the system at JRR-3M of JAERI. (author)

Modelling the perception of weather conditions by users of outdoor public spaces

Science.gov (United States)

Andrade, H.; Oliveira, S.; Alcoforado, M.-J.

2009-09-01

Outdoor public spaces play an important role for the quality of life in urban areas. Their usage depends, among other factors, on the bioclimatic comfort of the users. Climate change can modify the uses of outdoor spaces, by changing temperature and rainfall patterns. Understanding the way people perceive the microclimatic conditions is an important tool to the design of more comfortable outdoor spaces and in anticipating future needs to cope with climate change impacts. The perception of bioclimatic comfort by users of two different outdoor spaces was studied in Lisbon. A survey of about one thousand inquires was carried out simultaneously with weather measurements (air temperature, wind speed, relative humidity and solar and long wave radiation), during the years 2006 and 2007. The aim was to assess the relationships between weather variables, the individual characteristics of people (such as age and gender, among others) and their bioclimatic comfort. The perception of comfort was evaluated through the preference votes of the interviewees, which consisted on their answers concerning the desire to decrease, maintain or increase the values of the different weather parameters, in order to improve their comfort at the moment of the interview. The perception of the atmospheric conditions and of the bioclimatic comfort are highly influenced by subjective factors, which are difficult to integrate in a model. Nonetheless, the use of the multiple logistic regression allows the definition of patterns in the quantitative relation between preference votes and environmental and personal parameters. The thermal preference depends largely on the season and is associated with wind speed. Comfort in relation to wind depends not only on the speed but also on turbulence: a high variability in wind speed is generally perceived as uncomfortable. It was also found that the acceptability of warmer conditions is higher than for cooler conditions and the majority of people declared

Crenarchaeal biofilm formation under extreme conditions.

Directory of Open Access Journals (Sweden)

Andrea Koerdt

Full Text Available BACKGROUND: Biofilm formation has been studied in much detail for a variety of bacterial species, as it plays a major role in the pathogenicity of bacteria. However, only limited information is available for the development of archaeal communities that are frequently found in many natural environments. METHODOLOGY: We have analyzed biofilm formation in three closely related hyperthermophilic crenarchaeotes: Sulfolobus acidocaldarius, S. solfataricus and S. tokodaii. We established a microtitre plate assay adapted to high temperatures to determine how pH and temperature influence biofilm formation in these organisms. Biofilm analysis by confocal laser scanning microscopy demonstrated that the three strains form very different communities ranging from simple carpet-like structures in S. solfataricus to high density tower-like structures in S. acidocaldarius in static systems. Lectin staining indicated that all three strains produced extracellular polysaccharides containing glucose, galactose, mannose and N-acetylglucosamine once biofilm formation was initiated. While flagella mutants had no phenotype in two days old static biofilms of S. solfataricus, a UV-induced pili deletion mutant showed decreased attachment of cells. CONCLUSION: The study gives first insights into formation and development of crenarchaeal biofilms in extreme environments.

SOI MESFETs for Extreme Environment Electronics, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We are proposing a new extreme environment electronics (EEE) technology based on silicon-on-insulator (SOI) metal-semiconductor field-effect transistors (MESFETs)....

Frequently Asked Questions (FAQ) about Extreme Heat

Science.gov (United States)

... Extreme Heat Older Adults (Aged 65+) Infants and Children Chronic Medical Conditions Low Income Athletes Outdoor Workers Pets Hot Weather Tips Warning Signs and Symptoms FAQs Social Media How to Stay Cool Missouri Cooling Centers Extreme ...

LIFE experiment: isolation of cryptoendolithic organisms from Antarctic colonized sandstone exposed to space and simulated Mars conditions on the international space station.

Science.gov (United States)

Scalzi, Giuliano; Selbmann, Laura; Zucconi, Laura; Rabbow, Elke; Horneck, Gerda; Albertano, Patrizia; Onofri, Silvano

2012-06-01

Desiccated Antarctic rocks colonized by cryptoendolithic communities were exposed on the International Space Station (ISS) to space and simulated Mars conditions (LiFE-Lichens and Fungi Experiment). After 1.5 years in space samples were retrieved, rehydrated and spread on different culture media. Colonies of a green alga and a pink-coloured fungus developed on Malt-Agar medium; they were isolated from a sample exposed to simulated Mars conditions beneath a 0.1 % T Suprasil neutral density filter and from a sample exposed to space vacuum without solar radiation exposure, respectively. None of the other flight samples showed any growth after incubation. The two organisms able to grow were identified at genus level by Small SubUnit (SSU) and Internal Transcribed Spacer (ITS) rDNA sequencing as Stichococcus sp. (green alga) and Acarospora sp. (lichenized fungal genus) respectively. The data in the present study provide experimental information on the possibility of eukaryotic life transfer from one planet to another by means of rocks and of survival in Mars environment.

Gender and Space: Analysis of Factors Conditioning Equity in the Public Space

Directory of Open Access Journals (Sweden)

Pablo Paramo Bernal

2011-01-01

Full Text Available This article discusses gender research in urban public space through three different perspectives: the social representations and differentiated uses of space, the division of roles in public and private spaces, and urban planning of public space. The paper gathers and analyses some studies that complement the state of art and literature on women and space giving evidence on how women have been segregated from public space and are victim of gender inequalities. Public space does not exist absolutely nor gender; instead both are socially constructed by social order and reproduced by social practices. Finally, some suggestions for urban planning and research are given in order to respond women’s needs in public space.

Extreme climatic events in relation to global change and their impact on life histories

Directory of Open Access Journals (Sweden)

Juan MORENO, Anders Pape Møller

2011-06-01

Full Text Available Extreme weather conditions occur at an increasing rate as evidenced by higher frequency of hurricanes and more extreme precipitation and temperature anomalies. Such extreme environmental conditions will have important implications for all living organisms through greater frequency of reproductive failure and reduced adult survival. We review examples of reproductive failure and reduced survival related to extreme weather conditions. Phenotypic plasticity may not be sufficient to allow adaptation to extreme weather for many animals. Theory predicts reduced reproductive effort as a response to increased stochasticity. We predict that patterns of natural selection will change towards truncation selection as environmental conditions become more extreme. Such changes in patterns of selection may facilitate adaptation to extreme events. However, effects of selection on reproductive effort are difficult to detect. We present a number of predictions for the effects of extreme weather conditions in need of empirical tests. Finally, we suggest a number of empirical reviews that could improve our ability to judge the effects of extreme environmental conditions on life history [Current Zoology 57 (3: 375–389, 2011].

Evaluation of COTS Electronic Parts for Extreme Temperature Use in NASA Missions

Science.gov (United States)

Patterson, Richard L.; Hammoud, Ahmad; Elbuluk, Malik

2008-01-01

Electronic systems capable of extreme temperature operation are required for many future NASA space exploration missions where it is desirable to have smaller, lighter, and less expensive spacecraft and probes. Presently, spacecraft on-board electronics are maintained at about room temperature by use of thermal control systems. An Extreme Temperature Electronics Program at the NASA Glenn Research Center focuses on development of electronics suitable for space exploration missions. The effects of exposure to extreme temperatures and thermal cycling are being investigated for commercial-off-the-shelf components as well as for components specially developed for harsh environments. An overview of this program along with selected data is presented.

''Free-space'' boundary conditions for the time-dependent wave equation

International Nuclear Information System (INIS)

Lindman, E.L.

1975-01-01

Boundary conditions for the discrete wave equation which act like an infinite region of free space in contact with the computational region can be constructed using projection operators. Propagating and evanescent waves coming from within the computational region generate no reflected waves as they cross the boundary. At the same time arbitrary waves may be launched into the computational region. Well known projection operators for one-dimensional waves may be used for this purpose in one dimension. Extensions of these operators to higher dimensions along with numerically efficient approximations to them are described for higher-dimensional problems. The separation of waves into ingoing and outgoing waves inherent in these boundary conditions greatly facilitates diagnostics

Extreme weather events and infectious disease outbreaks.

Science.gov (United States)

McMichael, Anthony J

2015-01-01

Human-driven climatic changes will fundamentally influence patterns of human health, including infectious disease clusters and epidemics following extreme weather events. Extreme weather events are projected to increase further with the advance of human-driven climate change. Both recent and historical experiences indicate that infectious disease outbreaks very often follow extreme weather events, as microbes, vectors and reservoir animal hosts exploit the disrupted social and environmental conditions of extreme weather events. This review article examines infectious disease risks associated with extreme weather events; it draws on recent experiences including Hurricane Katrina in 2005 and the 2010 Pakistan mega-floods, and historical examples from previous centuries of epidemics and 'pestilence' associated with extreme weather disasters and climatic changes. A fuller understanding of climatic change, the precursors and triggers of extreme weather events and health consequences is needed in order to anticipate and respond to the infectious disease risks associated with human-driven climate change. Post-event risks to human health can be constrained, nonetheless, by reducing background rates of persistent infection, preparatory action such as coordinated disease surveillance and vaccination coverage, and strengthened disaster response. In the face of changing climate and weather conditions, it is critically important to think in ecological terms about the determinants of health, disease and death in human populations.

Common fixed point theorems in intuitionistic fuzzy metric spaces and L-fuzzy metric spaces with nonlinear contractive condition

International Nuclear Information System (INIS)

Jesic, Sinisa N.; Babacev, Natasa A.

2008-01-01

The purpose of this paper is to prove some common fixed point theorems for a pair of R-weakly commuting mappings defined on intuitionistic fuzzy metric spaces [Park JH. Intuitionistic fuzzy metric spaces. Chaos, Solitons and Fractals 2004;22:1039-46] and L-fuzzy metric spaces [Saadati R, Razani A, Adibi H. A common fixed point theorem in L-fuzzy metric spaces. Chaos, Solitons and Fractals, doi:10.1016/j.chaos.2006.01.023], with nonlinear contractive condition, defined with function, first observed by Boyd and Wong [Boyd DW, Wong JSW. On nonlinear contractions. Proc Am Math Soc 1969;20:458-64]. Following Pant [Pant RP. Common fixed points of noncommuting mappings. J Math Anal Appl 1994;188:436-40] we define R-weak commutativity for a pair of mappings and then prove the main results. These results generalize some known results due to Saadati et al., and Jungck [Jungck G. Commuting maps and fixed points. Am Math Mon 1976;83:261-3]. Some examples and comments according to the preceding results are given

Foundations of high-energy-density physics physical processes of matter at extreme conditions

CERN Document Server

Larsen, Jon

2017-01-01

High-energy-density physics explores the dynamics of matter at extreme conditions. This encompasses temperatures and densities far greater than we experience on Earth. It applies to normal stars, exploding stars, active galaxies, and planetary interiors. High-energy-density matter is found on Earth in the explosion of nuclear weapons and in laboratories with high-powered lasers or pulsed-power machines. The physics explored in this book is the basis for large-scale simulation codes needed to interpret experimental results whether from astrophysical observations or laboratory-scale experiments. The key elements of high-energy-density physics covered are gas dynamics, ionization, thermal energy transport, and radiation transfer, intense electromagnetic waves, and their dynamical coupling. Implicit in this is a fundamental understanding of hydrodynamics, plasma physics, atomic physics, quantum mechanics, and electromagnetic theory. Beginning with a summary of the topics and exploring the major ones in depth, thi...

Exploration of Extreme Terrain Using a Polyhedral Rover

Data.gov (United States)

National Aeronautics and Space Administration — Exploring celestial bodies with extreme terrains in our solar system, like Mars, Europa, Enceladus, and asteroids, are of great importance to NASA because these...

Expert consensus on facilitators and barriers to return-to-work following surgery for non-traumatic upper extremity conditions : A Delphi study

NARCIS (Netherlands)

Peters, S. E.; Johnston, V.; Ross, M.; Coppieters, M. W.

2017-01-01

This Delphi study aimed to reach consensus on important facilitators and barriers for return-to-work following surgery for non-traumatic upper extremity conditions. In Round 1, experts (n = 42) listed 134 factors, which were appraised in Rounds 2 and 3. Consensus (3/485% agreement) was achieved for

Extreme Environment High Temperature Communication Systems, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The purpose of this project is to develop and demonstrate a communications system capable of operation at extreme temperatures and pressures in hostile and corrosive...

Magnetic Logic Circuits for Extreme Environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The program aims to demonstrate a new genre of all-magnetic logic circuits which are radiation-tolerant and capable of reliable operation in extreme environmental...

A conditional extreme value theory approach in value-at-risk forecasting: Evidence from Southeastern Europe and USA market

Directory of Open Access Journals (Sweden)

Totić Selena

2015-01-01

Full Text Available As a consequence of the recent financial crisis, the adequacy of different Value-at-Risk (VaR methodologies was heavily questioned. Current practice in VaR assessment relies on modeling the whole distribution of returns. As an alternative, in this paper we model tail behavior of returns, and thus VaR, using conditional Extreme Value Theory (EVT, which combines EVT and GARCH methodology. Moreover, we examine the performance of conditional EVT with the daily returns of seven stock market indices, of which six are from Southeastern Europe (BelexLine, BET, BUX, CROBEX, SBITOP, SOFIX from the period of September 2004 - April 2013, and one from USA market (Standard&Poors 500 Index from the period January 1998 - April 2013. Backtesting of historical daily returns proves that conditional EVT model gives good predictions for all indices and for all confidence levels.

NASA X-Ray Observatory Completes Tests Under Harsh Simulated Space Conditions

Science.gov (United States)

1998-07-01

NASA's most powerful X-ray observatory has successfully completed a month-long series of tests in the extreme heat, cold, and airless conditions it will encounter in space during its five-year mission to shed new light on some of the darkest mysteries of the universe. The Advanced X-ray Astrophysics Facility was put through the rigorous testing as it was alternately heated and cooled in a special vacuum chamber at TRW Space and Electronics Group in Redondo Beach, Calif., NASA's prime contractor for the observatory. "Successful completion of thermal vacuum testing marks a significant step in readying the observatory for launch aboard the Space Shuttle in January," said Fred Wojtalik, manager of the Observatory Projects Office at NASA's Marshall Space Flight Center in Huntsville, Ala. "The observatory is a complex, highly sophisticated, precision instrument," explained Wojtalik. "We are pleased with the outcome of the testing, and are very proud of the tremendous team of NASA and contractor technicians, engineers and scientists that came together and worked hard to meet this challenging task." Testing began in May after the observatory was raised into the 60-foot thermal vacuum chamber at TRW. Testing was completed on June 20. During the tests the Advanced X-ray Astrophysics Facility was exposed to 232 degree heat and 195 degree below zero Fahrenheit cold. During four temperature cycles, all elements of the observatory - the spacecraft, telescope, and science instruments - were checked out. Computer commands directing the observatory to perform certain functions were sent from test consoles at TRW to all Advanced X-ray Astrophysics Facility components. A team of contractor and NASA engineers and scientists monitored and evaluated the results. Commands were also sent from, and test data monitored at, the Advanced X-ray Astrophysics Facility Operations Control Center in Cambridge, Mass., as part of the test series. The observatory will be managed and controlled from

Stable pelagic vertebrate community structure through extreme Paleogene greenhouse conditions

Science.gov (United States)

Sibert, E. C.; Friedman, M.; Hull, P. M.; Hunt, G.; Norris, R. D.

2016-02-01

The species composition (structure) and energy transfer (function) of an ecosystem is reflected by the presence and type of consumers that it supports. Here we use ichthyoliths, microfossil fish teeth and shark denticles, to assess the ecological variability of the pelagic fish community structure and composition from the Late Cretaceous to the middle Eocene from a drill core in the South Pacific gyre (DSDP Site 596). We find that the overall vertebrate community structure, as measured by the relative abundance of sharks to ray-finned fishes, has a punctuated change at the Cretaceous/Paleogene mass extinction. The vertebrate community structure remained stable throughout the Paleogene despite a five-fold increase in overall abundance of ichthyoliths during the extreme greenhouse of the Early Eocene. Further, we use a novel system to quantify the morphological variation in fish teeth. We find that the morphospace occupied by the tooth assemblage is conserved throughout the interval, with a slight expansion following the Cretaceous-Paleogene mass extinction, and the evolution of a distinct morphotype-group around the Paleocene-Eocene boundary. While there are elevated rates of morphotype origination and extinction following the Cretaceous-Paleogene mass extinction, the extreme greenhouse warming of the Early Eocene and associated increase in fish production produce near-zero origination and extinction rates. The relative stability in composition of the pelagic vertebrate community during intervals of extreme climate change and across large ranges of total fish accumulation, suggests that pelagic ecosystem structure is robust to climate events, and that the overall structure of the pelagic fish community may be decoupled from both climate and ecosystem function.

Dimension elevation in Müntz spaces: A new emergence of the Müntz condition

KAUST Repository

Ait-Haddou, Rachid

2014-05-01

We show that the limiting polygon generated by the dimension elevation algorithm with respect to the Müntz space span(1,tr1,tr2,trm,. . .), with 0 < r1 < r2 < ⋯ < r m < ⋯ and lim n →∞r n = ∞, over an interval [a, b] ⊂ ] 0, ∞ [ converges to the underlying Chebyshev-Bézier curve if and only if the Müntz condition ∑i=1∞1ri=∞ is satisfied. The surprising emergence of the Müntz condition in the problem raises the question of a possible connection between the density questions of nested Chebyshev spaces and the convergence of the corresponding dimension elevation algorithms. The question of convergence with no condition of monotonicity or positivity on the pairwise distinct real numbers r i remains an open problem. © 2014 Elsevier Inc.

SOI N-Channel Field Effect Transistors, CHT-NMOS80, for Extreme Temperatures

Science.gov (United States)

Patterson, Richard L.; Hammoud, Almad

2009-01-01

Extreme temperatures, both hot and cold, are anticipated in many of NASA space exploration missions as well as in terrestrial applications. One can seldom find electronics that are capable of operation under both regimes. Even for operation under one (hot or cold) temperature extreme, some thermal controls need to be introduced to provide appropriate ambient temperatures so that spacecraft on-board or field on-site electronic systems work properly. The inclusion of these controls, which comprise of heating elements and radiators along with their associated structures, adds to the complexity in the design of the system, increases cost and weight, and affects overall reliability. Thus, it would be highly desirable and very beneficial to eliminate these thermal measures in order to simplify system's design, improve efficiency, reduce development and launch costs, and improve reliability. These requirements can only be met through the development of electronic parts that are designed for proper and efficient operation under extreme temperature conditions. Silicon-on-insulator (SOI) based devices are finding more use in harsh environments due to the benefits that their inherent design offers in terms of reduced leakage currents, less power consumption, faster switching speeds, good radiation tolerance, and extreme temperature operability. Little is known, however, about their performance at cryogenic temperatures and under wide thermal swings. The objective of this work was to evaluate the performance of a new commercial-off-the-shelf (COTS) SOI parts over an extended temperature range and to determine the effects of thermal cycling on their performance. The results will establish a baseline on the suitability of such devices for use in space exploration missions under extreme temperatures, and will aid mission planners and circuit designers in the proper selection of electronic parts and circuits. The electronic part investigated in this work comprised of a CHT-NMOS80

[Injury mechanisms in extreme violence settings].

Science.gov (United States)

Arcaute-Velazquez, Fernando Federico; García-Núñez, Luis Manuel; Noyola-Vilallobos, Héctor Faustino; Espinoza-Mercado, Fernando; Rodríguez-Vega, Carlos Eynar

2016-01-01

Extreme violence events are consequence of current world-wide economic, political and social conditions. Injury patterns found among victims of extreme violence events are very complex, obeying several high-energy injury mechanisms. In this article, we present the basic concepts of trauma kinematics that regulate the clinical approach to victims of extreme violence events, in the hope that clinicians increase their theoretical armamentarium, and reflecting on obtaining better outcomes. Copyright © 2016. Published by Masson Doyma México S.A.

Effects of anthropogenic heat due to air-conditioning systems on an extreme high temperature event in Hong Kong

Science.gov (United States)

Wang, Y.; Li, Y.; Di Sabatino, S.; Martilli, A.; Chan, P. W.

2018-03-01

Anthropogenic heat flux is the heat generated by human activities in the urban canopy layer, which is considered the main contributor to the urban heat island (UHI). The UHI can in turn increase the use and energy consumption of air-conditioning systems. In this study, two effective methods for water-cooling air-conditioning systems in non-domestic areas, including the direct cooling system and central piped cooling towers (CPCTs), are physically based, parameterized, and implemented in a weather research and forecasting model at the city scale of Hong Kong. An extreme high temperature event (June 23-28, 2016) in the urban areas was examined, and we assessed the effects on the surface thermal environment, the interaction of sea-land breeze circulation and urban heat island circulation, boundary layer dynamics, and a possible reduction of energy consumption. The results showed that both water-cooled air-conditioning systems could reduce the 2 m air temperature by around 0.5 °C-0.8 °C during the daytime, and around 1.5 °C around 7:00-8:00 pm when the planetary boundary layer (PBL) height was confined to a few hundred meters. The CPCT contributed around 80%-90% latent heat flux and significantly increased the water vapor mixing ratio in the atmosphere by around 0.29 g kg-1 on average. The implementation of the two alternative air-conditioning systems could modify the heat and momentum of turbulence, which inhibited the evolution of the PBL height (a reduction of 100-150 m), reduced the vertical mixing, presented lower horizontal wind speed and buoyant production of turbulent kinetic energy, and reduced the strength of sea breeze and UHI circulation, which in turn affected the removal of air pollutants. Moreover, the two alternative air-conditioning systems could significantly reduce the energy consumption by around 30% during extreme high temperature events. The results of this study suggest potential UHI mitigation strategies and can be extended to

Use of diesel engines in industrial trucks operated in enclosed spaces

Energy Technology Data Exchange (ETDEWEB)

Dietrich, W; Reibold, G

1981-01-01

Report on emission investigations on a fork-lifter equipped with a low-pollutant MWM-engine, tests were carried out in enclosed spaces. The aim was to clarify if the maximum MPC at a place of work listed in a table of waste gas components can be observed even under unfavourable operating conditions of the fork lifter. The test is described, results are analysed. It is proved that there are no health hazards for the staff even under the extreme conditions chosen for the test.

Probabilistic analysis of extreme wind events

Energy Technology Data Exchange (ETDEWEB)

Chaviaropoulos, P.K. [Center for Renewable Energy Sources (CRES), Pikermi Attikis (Greece)

1997-12-31

A vital task in wind engineering and meterology is to understand, measure, analyse and forecast extreme wind conditions, due to their significant effects on human activities and installations like buildings, bridges or wind turbines. The latest version of the IEC standard (1996) pays particular attention to the extreme wind events that have to be taken into account when designing or certifying a wind generator. Actually, the extreme wind events within a 50 year period are those which determine the ``static`` design of most of the wind turbine components. The extremes which are important for the safety of wind generators are those associated with the so-called ``survival wind speed``, the extreme operating gusts and the extreme wind direction changes. A probabilistic approach for the analysis of these events is proposed in this paper. Emphasis is put on establishing the relation between extreme values and physically meaningful ``site calibration`` parameters, like probability distribution of the annual wind speed, turbulence intensity and power spectra properties. (Author)

Common fixed point theorems for fuzzy mappings in metric space under φ-contraction condition

International Nuclear Information System (INIS)

Abu-Donia, H.M.

2007-01-01

Some common fixed point theorems for multi-valued mappings under φ-contraction condition have been studied by Rashwan [Rashwan RA, Ahmed MA. Fixed points for φ-contraction type multivalued mappings. J Indian Acad Math 1995;17(2):194-204]. Butnariu [Butnariu D. Fixed point for fuzzy mapping. Fuzzy Sets Syst 1982;7:191-207] and Helipern [Hilpern S. Fuzzy mapping and fixed point theorem. J Math Anal Appl 1981;83:566-9] also, discussed some fixed point theorems for fuzzy mappings in the category of metric spaces. In this paper, we discussed some common fixed point theorems for fuzzy mappings in metric space under φ-contraction condition. Our investigation are related to the fuzzy form of Hausdorff metric which is a basic tool for computing Hausdorff dimensions. These dimensions help in understanding ε ∞ -space [El-Naschie MS. On the unification of the fundamental forces and complex time in the ε ∞ -space. Chaos, Solitons and Fractals 2000;11:1149-62] and are used in high energy physics [El-Naschie MS. Wild topology hyperbolic geometry and fusion algebra of high energy particle physics. Chaos, Solitons and Fractals 2002;13:1935-45

Common fixed point theorems for fuzzy mappings in metric space under {phi}-contraction condition

Energy Technology Data Exchange (ETDEWEB)

Abu-Donia, H.M. [Department of Mathematics, Faculty of Science, Zagazig University, Zagazig (Egypt)

2007-10-15

Some common fixed point theorems for multi-valued mappings under {phi}-contraction condition have been studied by Rashwan [Rashwan RA, Ahmed MA. Fixed points for {phi}-contraction type multivalued mappings. J Indian Acad Math 1995;17(2):194-204]. Butnariu [Butnariu D. Fixed point for fuzzy mapping. Fuzzy Sets Syst 1982;7:191-207] and Helipern [Hilpern S. Fuzzy mapping and fixed point theorem. J Math Anal Appl 1981;83:566-9] also, discussed some fixed point theorems for fuzzy mappings in the category of metric spaces. In this paper, we discussed some common fixed point theorems for fuzzy mappings in metric space under {phi}-contraction condition. Our investigation are related to the fuzzy form of Hausdorff metric which is a basic tool for computing Hausdorff dimensions. These dimensions help in understanding {epsilon} {sup {infinity}}-space [El-Naschie MS. On the unification of the fundamental forces and complex time in the {epsilon} {sup {infinity}}-space. Chaos, Solitons and Fractals 2000;11:1149-62] and are used in high energy physics [El-Naschie MS. Wild topology hyperbolic geometry and fusion algebra of high energy particle physics. Chaos, Solitons and Fractals 2002;13:1935-45].

Changes in the probability of co-occurring extreme climate events

Science.gov (United States)

Diffenbaugh, N. S.

2017-12-01

Extreme climate events such as floods, droughts, heatwaves, and severe storms exert acute stresses on natural and human systems. When multiple extreme events co-occur, either in space or time, the impacts can be substantially compounded. A diverse set of human interests - including supply chains, agricultural commodities markets, reinsurance, and deployment of humanitarian aid - have historically relied on the rarity of extreme events to provide a geographic hedge against the compounded impacts of co-occuring extremes. However, changes in the frequency of extreme events in recent decades imply that the probability of co-occuring extremes is also changing, and is likely to continue to change in the future in response to additional global warming. This presentation will review the evidence for historical changes in extreme climate events and the response of extreme events to continued global warming, and will provide some perspective on methods for quantifying changes in the probability of co-occurring extremes in the past and future.

Observations and Predictions of Wave Runup, Extreme Water Levels, and Medium-Term Dune Erosion during Storm Conditions

Directory of Open Access Journals (Sweden)

Serge Suanez

2015-07-01

Full Text Available Monitoring of dune erosion and accretion on the high-energy macrotidal Vougot beach in North Brittany (France over the past decade (2004–2014 has revealed significant morphological changes. Dune toe erosion/accretion records have been compared with extreme water level measurements, defined as the sum of (i astronomic tide; (ii storm surge; and (iii vertical wave runup. Runup parameterization was conducted using swash limits, beach profiles, and hydrodynamic (Hm0, Tm0,–1, and high tide water level—HTWL data sets obtained from high frequency field surveys. The aim was to quantify in-situ environmental conditions and dimensional swash parameters for the best calibration of Battjes [1] runup formula. In addition, an empirical equation based on observed tidal water level and offshore wave height was produced to estimate extreme water levels over the whole period of dune morphological change monitoring. A good correlation between this empirical equation (1.01Hmoξo and field runup measurements (Rmax was obtained (R2 85%. The goodness of fit given by the RMSE was about 0.29 m. A good relationship was noticed between dune erosion and high water levels when the water levels exceeded the dune foot elevation. In contrast, when extreme water levels were below the height of the toe of the dune sediment budget increased, inducing foredune recovery. These erosion and accretion phases may be related to the North Atlantic Oscillation Index.

High-efficiency pump for space helium transfer. Final Technical Report

International Nuclear Information System (INIS)

Hasenbein, R.; Izenson, M.G.; Swift, W.L.; Sixsmith, H.

1991-12-01

A centrifugal pump was developed for the efficient and reliable transfer of liquid helium in space. The pump can be used to refill cryostats on orbiting satellites which use liquid helium for refrigeration at extremely low temperatures. The pump meets the head and flow requirements of on-orbit helium transfer: a flow rate of 800 L/hr at a head of 128 J/kg. The overall pump efficiency at the design point is 0.45. The design head and flow requirements are met with zero net positive suction head, which is the condition in an orbiting helium supply Dewar. The mass transfer efficiency calculated for a space transfer operation is 0.99. Steel ball bearings are used with gas fiber-reinforced teflon retainers to provide solid lubrication. These bearings have demonstrated the longest life in liquid helium endurance tests under simulated pumping conditions. Technology developed in the project also has application for liquid helium circulation in terrestrial facilities and for transfer of cryogenic rocket propellants in space

Extreme river flow dependence in Northern Scotland

Science.gov (United States)

Villoria, M. Franco; Scott, M.; Hoey, T.; Fischbacher-Smith, D.

2012-04-01

Various methods for the spatial analysis of hydrologic data have been developed recently. Here we present results using the conditional probability approach proposed by Keef et al. [Appl. Stat. (2009): 58,601-18] to investigate spatial interdependence in extreme river flows in Scotland. This approach does not require the specification of a correlation function, being mostly suitable for relatively small geographical areas. The work is motivated by the Flood Risk Management Act (Scotland (2009)) which requires maps of flood risk that take account of spatial dependence in extreme river flow. The method is based on two conditional measures of spatial flood risk: firstly the conditional probability PC(p) that a set of sites Y = (Y 1,...,Y d) within a region C of interest exceed a flow threshold Qp at time t (or any lag of t), given that in the specified conditioning site X > Qp; and, secondly the expected number of sites within C that will exceed a flow Qp on average (given that X > Qp). The conditional probabilities are estimated using the conditional distribution of Y |X = x (for large x), which can be modeled using a semi-parametric approach (Heffernan and Tawn [Roy. Statist. Soc. Ser. B (2004): 66,497-546]). Once the model is fitted, pseudo-samples can be generated to estimate functionals of the joint tails of the distribution of (Y,X). Conditional return level plots were directly compared to traditional return level plots thus improving our understanding of the dependence structure of extreme river flow events. Confidence intervals were calculated using block bootstrapping methods (100 replicates). We report results from applying this approach to a set of four rivers (Dulnain, Lossie, Ewe and Ness) in Northern Scotland. These sites were chosen based on data quality, spatial location and catchment characteristics. The river Ness, being the largest (catchment size 1839.1km2) was chosen as the conditioning river. Both the Ewe (441.1km2) and Ness catchments have

Medial Elbow Joint Space Increases With Valgus Stress and Decreases When Cued to Perform A Maximal Grip Contraction.

Science.gov (United States)

Pexa, Brett S; Ryan, Eric D; Myers, Joseph B

2018-04-01

Previous research indicates that the amount of valgus torque placed on the elbow joint during overhead throwing is higher than the medial ulnar collateral ligament (UCL) can tolerate. Wrist and finger flexor muscle activity is hypothesized to make up for this difference, and in vitro studies that simulated activity of upper extremity musculature, specifically the flexor digitorum superficialis and flexor carpi ulnaris, support this hypothesis. To assess the medial elbow joint space at rest, under valgus stress, and under valgus stress with finger and forearm flexor contraction by use of ultrasonography in vivo. Controlled laboratory study. Participants were 22 healthy males with no history of elbow dislocation or UCL injury (age, 21.25 ± 1.58 years; height, 1.80 ± 0.08 m; weight, 79.43 ± 18.50 kg). Medial elbow joint space was measured by use of ultrasonography during 3 separate conditions: at rest (unloaded), under valgus load (loaded), and with a maximal grip contraction under a valgus load (loaded-contracted) in both limbs. Participants lay supine with their arm abducted 90° and elbow flexed 30° with the forearm in full supination. A handgrip dynamometer was placed in the participants' hand to grip against during the contracted condition. Images were reduced in ImageJ to assess medial elbow joint space. A 2-way (condition × limb) repeated-measures analysis of variance and Cohen's d effect sizes were used to assess changes in medial elbow joint space. Post hoc testing was performed with a Bonferroni adjustment to assess changes within limb and condition. The medial elbow joint space was significantly larger in the loaded condition (4.91 ± 1.16 mm) compared with the unloaded condition (4.26 ± 1.23 mm, P space increases under a valgus load and then decreases when a maximal grip contraction is performed. This indicates that wrist and finger flexor muscle contraction may assist in limiting medial elbow joint space, a result similar to findings of previous

Statistical Model of Extreme Shear

DEFF Research Database (Denmark)

Larsen, Gunner Chr.; Hansen, Kurt Schaldemose

2004-01-01

In order to continue cost-optimisation of modern large wind turbines, it is important to continously increase the knowledge on wind field parameters relevant to design loads. This paper presents a general statistical model that offers site-specific prediction of the probability density function...... by a model that, on a statistically consistent basis, describe the most likely spatial shape of an extreme wind shear event. Predictions from the model have been compared with results from an extreme value data analysis, based on a large number of high-sampled full-scale time series measurements...... are consistent, given the inevitabel uncertainties associated with model as well as with the extreme value data analysis. Keywords: Statistical model, extreme wind conditions, statistical analysis, turbulence, wind loading, statistical analysis, turbulence, wind loading, wind shear, wind turbines....

Extreme values, regular variation and point processes

CERN Document Server

Resnick, Sidney I

1987-01-01

Extremes Values, Regular Variation and Point Processes is a readable and efficient account of the fundamental mathematical and stochastic process techniques needed to study the behavior of extreme values of phenomena based on independent and identically distributed random variables and vectors It presents a coherent treatment of the distributional and sample path fundamental properties of extremes and records It emphasizes the core primacy of three topics necessary for understanding extremes the analytical theory of regularly varying functions; the probabilistic theory of point processes and random measures; and the link to asymptotic distribution approximations provided by the theory of weak convergence of probability measures in metric spaces The book is self-contained and requires an introductory measure-theoretic course in probability as a prerequisite Almost all sections have an extensive list of exercises which extend developments in the text, offer alternate approaches, test mastery and provide for enj...

Changes of extreme precipitation and nonlinear influence of climate variables over monsoon region in China

KAUST Repository

Gao, Tao; Wang, Huixia Judy; Zhou, Tianjun

2017-01-01

of precipitation extremes over monsoon regions in China (MRC). However, research on monsoon extremes in China and their associations with climate variables is limited. In this study, we examine the space-time variations of extreme precipitation across the MRC

Detecting impacts of extreme events with ecological in situ monitoring networks

Directory of Open Access Journals (Sweden)

M. D. Mahecha

2017-09-01

Full Text Available Extreme hydrometeorological conditions typically impact ecophysiological processes on land. Satellite-based observations of the terrestrial biosphere provide an important reference for detecting and describing the spatiotemporal development of such events. However, in-depth investigations of ecological processes during extreme events require additional in situ observations. The question is whether the density of existing ecological in situ networks is sufficient for analysing the impact of extreme events, and what are expected event detection rates of ecological in situ networks of a given size. To assess these issues, we build a baseline of extreme reductions in the fraction of absorbed photosynthetically active radiation (FAPAR, identified by a new event detection method tailored to identify extremes of regional relevance. We then investigate the event detection success rates of hypothetical networks of varying sizes. Our results show that large extremes can be reliably detected with relatively small networks, but also reveal a linear decay of detection probabilities towards smaller extreme events in log–log space. For instance, networks with  ≈  100 randomly placed sites in Europe yield a  ≥  90 % chance of detecting the eight largest (typically very large extreme events; but only a  ≥  50 % chance of capturing the 39 largest events. These findings are consistent with probability-theoretic considerations, but the slopes of the decay rates deviate due to temporal autocorrelation and the exact implementation of the extreme event detection algorithm. Using the examples of AmeriFlux and NEON, we then investigate to what degree ecological in situ networks can capture extreme events of a given size. Consistent with our theoretical considerations, we find that today's systematically designed networks (i.e. NEON reliably detect the largest extremes, but that the extreme event detection rates are not higher than would

Improving real-time estimation of heavy-to-extreme precipitation using rain gauge data via conditional bias-penalized optimal estimation

Science.gov (United States)

Seo, Dong-Jun; Siddique, Ridwan; Zhang, Yu; Kim, Dongsoo

2014-11-01

A new technique for gauge-only precipitation analysis for improved estimation of heavy-to-extreme precipitation is described and evaluated. The technique is based on a novel extension of classical optimal linear estimation theory in which, in addition to error variance, Type-II conditional bias (CB) is explicitly minimized. When cast in the form of well-known kriging, the methodology yields a new kriging estimator, referred to as CB-penalized kriging (CBPK). CBPK, however, tends to yield negative estimates in areas of no or light precipitation. To address this, an extension of CBPK, referred to herein as extended conditional bias penalized kriging (ECBPK), has been developed which combines the CBPK estimate with a trivial estimate of zero precipitation. To evaluate ECBPK, we carried out real-world and synthetic experiments in which ECBPK and the gauge-only precipitation analysis procedure used in the NWS's Multisensor Precipitation Estimator (MPE) were compared for estimation of point precipitation and mean areal precipitation (MAP), respectively. The results indicate that ECBPK improves hourly gauge-only estimation of heavy-to-extreme precipitation significantly. The improvement is particularly large for estimation of MAP for a range of combinations of basin size and rain gauge network density. This paper describes the technique, summarizes the results and shares ideas for future research.

EXTREME WINTERS IN XX–XXI CENTURIES AS INDICATORS OF SNOWINESS AND AVALANCHE HAZARD IN THE PAST AND EXPECTED CLIMATE CHANGE CONDITIONS

Directory of Open Access Journals (Sweden)

A. D. Oleynikov

2012-01-01

Full Text Available Currently, due to the global climate change and increasing frequency of weather events focus is on prediction of climate extremes. Large-scale meteorological anomalies can cause long-term paralysis of social and economic infrastructure of the major mountain regions and even individual states. In winter periods, these anomalies are associated with prolonged heavy snowfalls and associated with them catastrophic avalanches which cause significant social and economic damage. The climate system maintains a certain momentum during periods of adjustment and transition to other conditions in the ratio of heat and moisture and contains a climate «signal» of the climates of the past and the future. In our view seasonal and yearly extremes perform the role of these indicators, study of which enables for a deeper understanding and appreciation of the real situation of the climate periods related to the modern ones. The paper provides an overview of the criteria for selection of extreme winters. Identification of extremely cold winters during the period of instrumental observation and assessment of their snowiness and avalanche activity done for the Elbrus region, which is a model site for study of the avalanche regime in the Central Caucasus. The studies aim to identify the extreme winters in the Greater Caucasus, assess their frequency of occurrence, characterize the scale and intensity of the avalanche formation. The data obtained can be used to identify winter-analogues in the reconstruction and long-term forecast of avalanches. 

Aortic dissection: natural course of disease? Report of two cases representing the extremes of the condition

International Nuclear Information System (INIS)

Tollefsen, Isak; Joergensen, Ingrid K.; Woie, Leik; Fossdal, Jan E.

2001-01-01

Objective: In a time when diagnostic methods and above all, surgical as well as interventional radiological treatment for aortic aneurysms and aortic dissections have reached a point nobody could think of a few years back, the present authors feel that it is worth while to remind oneself of the natural course of disease in these conditions. Taking into consideration the high morbidity and mortality rate in surgically treated patients with aortic dissection, and the high complication rate per- and postoperatively, it also seems right to ask if a more expectative and conservative approach to the condition sometimes perhaps may be justified. Methods and material: Two case reports are given. One was a 15-year-old boy with Stanford (Daily) type B dissection who statistically ought to have a good prognosis, but who died within 2 h after onset of symptoms. The other patient, a middle-aged woman with Stanford type A dissection, survived for 25 years without operation. Conclusion: These two cases, though not unique viewed separately, we consider to represent the extremes of the condition and also a natural course of disease, while none of them was operated on

Aortic dissection: natural course of disease? Report of two cases representing the extremes of the condition.

Science.gov (United States)

Tollefsen, I; Jørgensen, I K; Woie, L; Fossdal, J E

2001-10-01

In a time when diagnostic methods and above all, surgical as well as interventional radiological treatment for aortic aneurysms and aortic dissections have reached a point nobody could think of a few years back, the present authors feel that it is worth while to remind oneself of the natural course of disease in these conditions. Taking into consideration the high morbidity and mortality rate in surgically treated patients with aortic dissection, and the high complication rate per- and postoperatively, it also seems right to ask if a more expectative and conservative approach to the condition sometimes perhaps may be justified. Two case reports are given. One was a 15-year-old boy with Stanford (Daily) type B dissection who statistically ought to have a good prognosis, but who died within 2 h after onset of symptoms. The other patient, a middle-aged woman with Stanford type A dissection, survived for 25 years without operation. These two cases, though not unique viewed separately, we consider to represent the extremes of the condition and also a natural course of disease, while none of them was operated on.

Human Performance under Extreme Conditions with Respect to a Resilient Organisation. Proceedings of a CSNI International Workshop, 24-26 February 2015, Brugg, Switzerland

International Nuclear Information System (INIS)

2015-01-01

After the Fukushima Daiichi accident a number of initiatives have been undertaken internationally to learn from the accident and to implement lessons learned to improve nuclear safety. The accident has shown in particular the challenges in supporting reliable human performance under extreme conditions. Acknowledging that further work is needed to be better prepared for the HOF (Human and Organisational Factors) challenges of the extreme conditions that may be present in severe accidents, the NEA's Working Group on Human and Organisational Factors (WGHOF), one of the working groups for the Committee on the Safety of Nuclear Installations (CSNI) initiated a new task with the objectives to: - share experiences and knowledge of human and organisational performance under extreme conditions, - identify specific currently applied HOF principles in nuclear and other high risk industries and compare them with the available knowledge, - provide a basis for improvements and necessary research taking into account HOF issues in the design and use of measures, and - make recommendations with the aim to achieve the best level of human and organisational performance as possible under extreme conditions. In order to move those issues forward WGHOF hosted together with the Swiss Federal Nuclear Safety Inspectorate ENSI a workshop entitled 'Human Performance under Extreme Conditions with respect to a Resilient Organization'. The workshop was conducted with participation of a number of invited key speakers from academic research and a range of industries, including nuclear. Thirty-four experts from 12 countries, the IAEA and OECD/Halden participated. Experts came from nuclear authorities, research centres, technical support organisations, training simulator centres, utilities and from non-nuclear field (aircraft accident investigation, fire fighting, military, design of resilient organisations). From the discussions at the workshop, it is clear that the accident at Fukushima has

[The heart in extreme sports: hyperbaric activity and microgravity].

Science.gov (United States)

Berrettini, Umberto; Landolfi, Angelo; Patteri, Giovanna

2008-10-01

The study of the cardiovascular and respiratory modifications in extreme environments could be useful for the understanding of the adaptive mechanisms of the body in particular conditions. The knowledge of how different environmental conditions in terms of extreme pressure, temperature and gravity modify the neurovegetative and cardiovascular system could be useful in daily practice for hypobaric and hyperbaric sports.

Conditions for extinction events in chemical reaction networks with discrete state spaces.

Science.gov (United States)

Johnston, Matthew D; Anderson, David F; Craciun, Gheorghe; Brijder, Robert

2018-05-01

We study chemical reaction networks with discrete state spaces and present sufficient conditions on the structure of the network that guarantee the system exhibits an extinction event. The conditions we derive involve creating a modified chemical reaction network called a domination-expanded reaction network and then checking properties of this network. Unlike previous results, our analysis allows algorithmic implementation via systems of equalities and inequalities and suggests sequences of reactions which may lead to extinction events. We apply the results to several networks including an EnvZ-OmpR signaling pathway in Escherichia coli.

The infrared camera prototype characterization for the JEM-EUSO space mission

International Nuclear Information System (INIS)

Morales de los Ríos, J.A.; Joven, E.; Peral, L. del; Reyes, M.; Licandro, J.; Rodríguez Frías, M.D.

2014-01-01

JEM-EUSO (Extreme Universe Space Observatory on Japanese Experiment Module) is an advanced observatory that will be on-board the International Space Station (ISS) and use the Earth's atmosphere as a huge calorimeter detector. However, the atmospheric clouds introduce uncertainties in the signals measured by JEM-EUSO. Therefore, it is extremely important to know the atmospheric conditions and properties of the clouds in the Field of View (FoV) of the telescope. The Atmospheric Monitoring System (AMS) of JEM-EUSO includes a lidar and an infrared imaging system, IR-Camera, aimed to detect the presence of clouds and to obtain the cloud coverage and cloud top altitude during the observations of the JEM-EUSO main telescope. To define the road-map for the design of the electronics, the detector has been tested extensively with a first prototype. The actual design of the IR-Camera, the test of the prototype, and the outcome of this characterization are presented in this paper

The infrared camera prototype characterization for the JEM-EUSO space mission

Energy Technology Data Exchange (ETDEWEB)

Morales de los Ríos, J.A., E-mail: josealberto.morales@uah.es [SPace and AStroparticle (SPAS) Group, UAH, Madrid (Spain); Ebisuzaki Computational Astrophysics Laboratory, RIKEN (Japan); Joven, E. [Instituto de Astrofísica de Canarias (IAC), Tenerife (Spain); Peral, L. del [SPace and AStroparticle (SPAS) Group, UAH, Madrid (Spain); Leonard E. Parker Center for Gravitation, Cosmology and Astrophysics, University of Wisconsin-Milwaukee (United States); Reyes, M. [Instituto de Astrofísica de Canarias (IAC), Tenerife (Spain); Licandro, J. [Instituto de Astrofísica de Canarias (IAC), Tenerife (Spain); Departamento de Astrofísica, Universidad de La Laguna, Tenerife (Spain); Rodríguez Frías, M.D. [SPace and AStroparticle (SPAS) Group, UAH, Madrid (Spain); Instituto de Astrofísica de Canarias (IAC), Tenerife (Spain)

2014-06-01

JEM-EUSO (Extreme Universe Space Observatory on Japanese Experiment Module) is an advanced observatory that will be on-board the International Space Station (ISS) and use the Earth's atmosphere as a huge calorimeter detector. However, the atmospheric clouds introduce uncertainties in the signals measured by JEM-EUSO. Therefore, it is extremely important to know the atmospheric conditions and properties of the clouds in the Field of View (FoV) of the telescope. The Atmospheric Monitoring System (AMS) of JEM-EUSO includes a lidar and an infrared imaging system, IR-Camera, aimed to detect the presence of clouds and to obtain the cloud coverage and cloud top altitude during the observations of the JEM-EUSO main telescope. To define the road-map for the design of the electronics, the detector has been tested extensively with a first prototype. The actual design of the IR-Camera, the test of the prototype, and the outcome of this characterization are presented in this paper.

Bootstrapping conformal field theories with the extremal functional method.

Science.gov (United States)

El-Showk, Sheer; Paulos, Miguel F

2013-12-13

The existence of a positive linear functional acting on the space of (differences between) conformal blocks has been shown to rule out regions in the parameter space of conformal field theories (CFTs). We argue that at the boundary of the allowed region the extremal functional contains, in principle, enough information to determine the dimensions and operator product expansion (OPE) coefficients of an infinite number of operators appearing in the correlator under analysis. Based on this idea we develop the extremal functional method (EFM), a numerical procedure for deriving the spectrum and OPE coefficients of CFTs lying on the boundary (of solution space). We test the EFM by using it to rederive the low lying spectrum and OPE coefficients of the two-dimensional Ising model based solely on the dimension of a single scalar quasiprimary--no Virasoro algebra required. Our work serves as a benchmark for applications to more interesting, less known CFTs in the near future.

Extreme Environment Electronics based on Silicon Carbide, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Radiation tolerant, extreme temperature capable electronics are needed for a variety of planned NASA missions. For example, in-situ exploration of Venus and long...

Extreme Environment Electronics based on Silicon Carbide, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Radiation tolerant, extreme temperature capable electronics are needed for a variety of planned NASA missions. For example, in-situ exploration of Venus and long...

Coordinated Hard Sphere Mixture (CHaSM): A fast approximate model for oxide and silicate melts at extreme conditions

Science.gov (United States)

Wolf, A. S.; Asimow, P. D.; Stevenson, D. J.

2015-12-01

Recent first-principles calculations (e.g. Stixrude, 2009; de Koker, 2013), shock-wave experiments (Mosenfelder, 2009), and diamond-anvil cell investigations (Sanloup, 2013) indicate that silicate melts undergo complex structural evolution at high pressure. The observed increase in cation-coordination (e.g. Karki, 2006; 2007) induces higher compressibilities and lower adiabatic thermal gradients in melts as compared with their solid counterparts. These properties are crucial for understanding the evolution of impact-generated magma oceans, which are dominated by the poorly understood behavior of silicates at mantle pressures and temperatures (e.g. Stixrude et al. 2009). Probing these conditions is difficult for both theory and experiment, especially given the large compositional space (MgO-SiO2-FeO-Al2O3-etc). We develop a new model to understand and predict the behavior of oxide and silicate melts at extreme P-T conditions (Wolf et al., 2015). The Coordinated Hard Sphere Mixture (CHaSM) extends the Hard Sphere mixture model, accounting for the range of coordination states for each cation in the liquid. Using approximate analytic expressions for the hard sphere model, this fast statistical method compliments classical and first-principles methods, providing accurate thermodynamic and structural property predictions for melts. This framework is applied to the MgO system, where model parameters are trained on a collection of crystal polymorphs, producing realistic predictions of coordination evolution and the equation of state of MgO melt over a wide P-T range. Typical Mg-coordination numbers are predicted to evolve continuously from 5.25 (0 GPa) to 8.5 (250 GPa), comparing favorably with first-principles Molecular Dynamics (MD) simulations. We begin extending the model to a simplified mantle chemistry using empirical potentials (generally accurate over moderate pressure ranges, consuming classical MD calculations. This approach also sheds light on the universality

Evaluation of comfort conditions in urban open spaces. Application in the island of Crete

International Nuclear Information System (INIS)

Tsitoura, Marianna; Tsoutsos, Theocharis; Daras, Tryfon

2014-01-01

Highlights: • Outdoor spaces field surveys carried out in four different urban open spaces. • A strong connection between the microclimate and the use of open space. • Human physical and psychological factors can optimize the urban space design. - Abstract: The thermal environment in outdoor public spaces and their level of use are strongly connected. The design of outdoor spaces, especially in urban areas, is very critical in Southern Europe due to their extended use during summertime where the urban heat island phenomenon deteriorates the microclimatic conditions. In this paper the main outcomes of outdoor spaces field surveys are presented, which were carried out in four different urban open spaces in Crete. On site measurements were implemented and a questionnaire was used in order to estimate the thermal comfort of visitors. Thermal indices like Predicted Mean Vote, Physiologically Equivalent Temperature, Standard Effective Temperature, Wet Bulb Globe Temperature are used to evaluate the features of urban microclimate and then are being compared in order to find the most suitable for the Mediterranean microclimate. This suggests another way of approach to the researcher and provides essential tools to the designer

Climate Extreme Events over Northern Eurasia in Changing Climate

Science.gov (United States)

Bulygina, O.; Korshunova, N. N.; Razuvaev, V. N.; Groisman, P. Y.

2014-12-01

During the period of widespread instrumental observations in Northern Eurasia, the annual surface air temperature has increased by 1.5°C. Close to the north in the Arctic Ocean, the late summer sea ice extent has decreased by 40% providing a near-infinite source of water vapor for the dry Arctic atmosphere in the early cold season months. The contemporary sea ice changes are especially visible in the Eastern Hemisphere All these factors affect the change extreme events. Daily and sub-daily data of 940 stations to analyze variations in the space time distribution of extreme temperatures, precipitation, and wind over Russia were used. Changing in number of days with thaw over Russia was described. The total seasonal numbers of days, when daily surface air temperatures (wind, precipitation) were found to be above (below) selected thresholds, were used as indices of climate extremes. Changing in difference between maximum and minimum temperature (DTR) may produce a variety of effects on biological systems. All values falling within the intervals ranged from the lowest percentile to the 5th percentile and from the 95th percentile to the highest percentile for the time period of interest were considered as daily extremes. The number of days, N, when daily temperatures (wind, precipitation, DTR) were within the above mentioned intervals, was determined for the seasons of each year. Linear trends in the number of days were calculated for each station and for quasi-homogeneous climatic regions. Regional analysis of extreme events was carried out using quasi-homogeneous climatic regions. Maps (climatology, trends) are presented mostly for visualization purposes. Differences in regional characteristics of extreme events are accounted for over a large extent of the Russian territory and variety of its physical and geographical conditions. The number of days with maximum temperatures higher than the 95% percentile has increased in most of Russia and decreased in Siberia in

Base Oil-Extreme Pressure Additive Synergy in Lubricants

Science.gov (United States)

Extreme pressure (EP) additives are those containing reactive elements such as sulfur, phosphorus, and chlorine. In lubrication processes that occur under extremely severe conditions (e.g., high pressure and/or slow speed), these elements undergo chemical reactions generating new materials (tribofi...

α'-Corrections to extremal dyonic black holes in heterotic string theory

International Nuclear Information System (INIS)

Sahoo, Bindusar; Sen, Ashoke

2007-01-01

We explicitly compute the entropy of an extremal dyonic black hole in heterotic string theory compactified on T 6 or K3 x T 2 by taking into account all the tree level four derivative corrections to the low energy effective action. For supersymmetric black holes the result agrees with the answer obtained earlier 1) by including only the Gauss-Bonnet corrections to the effective action 2) by including all terms related to the curvature squared terms via space-time supersymmetry transformation, and 3) by using general arguments based on the assumption of AdS 3 near horizon geometry and space-time supersymmetry. For non-supersymmetric extremal black holes the result agrees with the one based on the assumption of AdS 3 near horizon geometry and space-time supersymmetry of the underlying theory

Decrease in hydroclimatic conditions generating floods in the southeast of Belgium over the last 50 years resulting from changes in seasonal snow cover and extreme precipitation events

Science.gov (United States)

Wyard, Coraline; Fettweis, Xavier

2016-04-01

As a consequence of climate change, several studies concluded that winter flood occurrence could increase in the future in many rivers of northern and western Europe in response to an increase in extreme precipitation events. This study aims to determine if trends in extreme hydroclimatic events generating floods can already be detected over the last century. In particular, we focus on the Ourthe River (southeast of Belgium) which is one of the main tributaries of the Meuse River with a catchment area of 3500 km². In this river, most of the floods occur during winter and about 50% of them are due to rainfall events associated with the melting of the snow which covers the Ardennes during winter. In this study, hydroclimatic conditions favorable to flooding were reconstructed over the 20th century using the regional climate model MAR ("Modèle Atmosphérique Régional") forced by the following reanalyses: the ERA-20C, the ERA-Interim and the NCEP/NCAR-v1. The use of the MAR model allows to compute precipitation, snow depth and run-off resulting from precipitation events and snow melting in any part of the Ourthe river catchment area. Therefore, extreme hydroclimatic events, namely extreme run-off events, which could potentially generate floods, can be reconstructed using the MAR model. As validation, the MAR results were compared to weather station-based data. A trend analysis was then performed in order to study the evolution of conditions favorable to flooding in the Ourthe River catchment. The results show that the MAR model allows the detection of more than 95% of the hydroclimatic conditions which effectively generated observed floods in the Ourthe River over the 1974-2014 period. Conditions favorable to flooding present a negative trend over the last 50 years as a result of a decrease in snow accumulation and in extreme precipitation events. However, significance of these trends depends on the reanalysis used to force the regional climate model as well as the

An influence of extremal edges on boundary extension.

Science.gov (United States)

Hale, Ralph G; Brown, James M; McDunn, Benjamin A; Siddiqui, Aisha P

2015-08-01

Studies have shown that people consistently remember seeing more of a studied scene than was physically present (e.g., Intraub & Richardson Journal of Experimental Psychology: Learning, Memory, and Cognition, 15, 179-187, 1989). This scene memory error, known as boundary extension, has been suggested to occur due to an observer's failure to differentiate between the contributing sources of information, including the sensory input, amodal continuation beyond the view boundaries, and contextual associations with the main objects and depicted scene locations (Intraub, 2010). Here, "scenes" made of abstract shapes on random-dot backgrounds, previously shown to elicit boundary extension (McDunn, Siddiqui, & Brown Psychonomic Bulletin & Review, 21, 370-375, 2014), were compared with versions made with extremal edges (Palmer & Ghose Psychological Science, 19, 77-84, 2008) added to their borders, in order to examine how boundary extension is influenced when amodal continuation at the borders' view boundaries is manipulated in this way. Extremal edges were expected to reduce boundary extension as compared to the same scenes without them, because extremal edge boundaries explicitly indicate an image's end (i.e., they do not continue past the view boundary). A large and a small difference (16 % and 40 %) between the close and wide-angle views shown during the experiment were tested to examine the effects of both boundary extension and normalization with and without extremal edges. Images without extremal edges elicited typical boundary extension for the 16 % size change condition, whereas the 40 % condition showed signs of normalization. With extremal edges, a reduced amount of boundary extension occurred for the 16 % condition, and only normalization was found for the 40 % condition. Our findings support and highlight the importance of amodal continuation at the view boundaries as a component of boundary extension.

The quantum null energy condition in curved space

Science.gov (United States)

Fu, Zicao; Koeller, Jason; Marolf, Donald

2017-11-01

The quantum null energy condition (QNEC) is a conjectured bound on components (Tkk = Tab ka k^b) of the stress tensor along a null vector k a at a point p in terms of a second k-derivative of the von Neumann entropy S on one side of a null congruence N through p generated by k a . The conjecture has been established for super-renormalizeable field theories at points p that lie on a bifurcate Killing horizon with null tangent k a and for large-N holographic theories on flat space. While the Koeller-Leichenauer holographic argument clearly yields an inequality for general ( p, k^a) , more conditions are generally required for this inequality to be a useful QNEC. For d≤slant 3 , for arbitrary backgroud metric we show that the QNEC is naturally finite and independent of renormalization scheme when the expansion θ of N at the point p vanishes. This is consistent with the original QNEC conjecture which required θ and the shear σab to satisfy θ \\vert _p= \\dotθ\\vert p =0 , σab\\vert _p=0 . But for d=4, 5 more conditions than even these are required. In particular, we also require the vanishing of additional derivatives and a dominant energy condition. In the above cases the holographic argument does indeed yield a finite QNEC, though for d≥slant6 we argue these properties to fail even for weakly isolated horizons (where all derivatives of θ, σab vanish) that also satisfy a dominant energy condition. On the positive side, a corrollary to our work is that, when coupled to Einstein-Hilbert gravity, d ≤slant 3 holographic theories at large N satisfy the generalized second law (GSL) of thermodynamics at leading order in Newton’s constant G. This is the first GSL proof which does not require the quantum fields to be perturbations to a Killing horizon.

Variations of extreme rainfall in space and time

DEFF Research Database (Denmark)

Gregersen, Ida Bülow; Madsen, H.; Rosbjerg, Dan

2012-01-01

variation, whereas annual variations are related to changes in the average Danish summer precipitation, the average Danish summer temperature and the East Atlantic pattern. The spatio-temporal Poisson regression model was found to be a helpful tool when comparing the internal importance of these variables......In the ongoing climate change discussion, methods for identification of variability governed by climate change are important tools. The magnitude of variables that can describe this variability should be compared with magnitudes of variables describing variability in a stationary setting....... This study focuses on variations of extreme rainfall events, observed at 70 different locations in Denmark over a period of 31 years. The aim is to identify and compare variables, both spatially and temporally, which can explain different parts of the variability in this data set. Assuming that the number...

Evaluation of Extremal Hypotheses as a Criterion to Resolve Channel Indeterminacy

Science.gov (United States)

Tranmer, A.

2012-12-01

Design criteria for river restoration and sustainable development have significantly advanced in recent decades, yet complete deterministic formulations to address channel form and sinuosity still prove elusive. Many hypotheses have been presented to ascertain the dynamic-equilibrium of a stream at both the cross sectional and reach level. These efforts to better understand the functioning of alluvial systems include regime theory, stability theory, perturbation analysis, threshold theory, reference reach comparison, downstream hydraulic geometry, and extremal hypotheses. The latter of these theories, the extremal hypothesis, is based on optimizing one variable or criterion in the alluvial system in order to find closure to the channel design problem. Currently, there is no method to directly compare the various hypotheses at the system scale, understanding of their sensitivity to the various formulae employed or consensus regarding which hypothesis is most appropriate. This study analyzed the various extremal hypotheses in as close to a pristine environment as exists (a remote part of Patagonia, Chile), in order to assess which hypothesis (or collective hypotheses) is most appropriate for channel design. Extremal hypotheses were applied in the longitudinal direction, under the assumption of a space-for-time substitution, to evaluate the geomorphic trends of a river evolving during deglaciation. The space-for-time model assumes the watershed reaches stable, dynamic-equilibrium in its lower meandering reaches and the point of equilibrium extends upstream through its braiding reaches as the watershed adapts to new climatic and environmental conditions. Extremal hypotheses applied in a downstream fashion are then expected to predict chaotic and oversized channel characteristics in the upstream reaches and trend towards a point of equilibrium (minimum/maximum of tested hypothesis). Initial findings indicate that many hypotheses predict similar geometry and sinuosity

Spatial extreme value analysis to project extremes of large-scale indicators for severe weather.

Science.gov (United States)

Gilleland, Eric; Brown, Barbara G; Ammann, Caspar M

2013-09-01

Concurrently high values of the maximum potential wind speed of updrafts ( W max ) and 0-6 km wind shear (Shear) have been found to represent conducive environments for severe weather, which subsequently provides a way to study severe weather in future climates. Here, we employ a model for the product of these variables (WmSh) from the National Center for Atmospheric Research/United States National Center for Environmental Prediction reanalysis over North America conditioned on their having extreme energy in the spatial field in order to project the predominant spatial patterns of WmSh. The approach is based on the Heffernan and Tawn conditional extreme value model. Results suggest that this technique estimates the spatial behavior of WmSh well, which allows for exploring possible changes in the patterns over time. While the model enables a method for inferring the uncertainty in the patterns, such analysis is difficult with the currently available inference approach. A variation of the method is also explored to investigate how this type of model might be used to qualitatively understand how the spatial patterns of WmSh correspond to extreme river flow events. A case study for river flows from three rivers in northwestern Tennessee is studied, and it is found that advection of WmSh from the Gulf of Mexico prevails while elsewhere, WmSh is generally very low during such extreme events. © 2013 The Authors. Environmetrics published by JohnWiley & Sons, Ltd.

Predicting the solubility of gases in Nitrile Butadiene Rubber in extreme conditions using molecular simulation

Science.gov (United States)

Khawaja, Musab; Molinari, Nicola; Sutton, Adrian; Mostofi, Arash

In the oil and gas industry, elastomer seals play an important role in protecting sensitive monitoring equipment from contamination by gases - a problem that is exacerbated by the high pressures and temperatures found down-hole. The ability to predict and prevent such permeative failure has proved elusive to-date. Nitrile butadiene rubber (NBR) is a common choice of elastomer for seals due to its resistance to heat and fuels. In the conditions found in the well it readily absorbs small molecular weight gases. How this behaviour changes quantitatively for different gases as a function of temperature and pressure is not well-understood. In this work a series of fully atomistic simulations are performed to understand the effect of extreme conditions on gas solubility in NBR. Widom particle insertion is used to compute solubilities. The importance of sampling and allowing structural relaxation upon compression are highlighted, and qualitatively reasonable trends reproduced. Finally, while at STP it has previously been shown that the solubility of CO2 is higher than that of He in NBR, we observe that under the right circumstances it is possible to reverse this trend.

Influence of the atmosphere on the space detection of ultra-high energy cosmic rays

International Nuclear Information System (INIS)

Moreggia, S.

2007-06-01

EUSO (Extreme Universe Space Observatory) is a project of ultra-high energy (> 10 20 eV) cosmic rays detection from space. Its concept relies on the observation of fluorescence and Cerenkov photons emitted by extensive air showers from a telescope located on the International Space Station. A simulation software has been developed to study the characteristics of this innovative concept of detection. It deals with the different steps of the detection chain: extensive air shower development, emission of fluorescence and Cerenkov light, and radiative transfer to the telescope. A Monte-Carlo code has been implemented to simulate the propagation of photons through the atmosphere, dealing with multiple scattering in clear sky conditions as well as in presence of aerosols and clouds. With this simulation program, the impact of atmospheric conditions on the performance of a space-located detector has been studied. The precise treatment of photons propagation through the atmosphere has permitted to quantify the scattered light contribution to the detected signal. (author)

MEMS Micro-Valve for Space Applications

Science.gov (United States)

Chakraborty, I.; Tang, W. C.; Bame, D. P.; Tang, T. K.

1998-01-01

We report on the development of a Micro-ElectroMechanical Systems (MEMS) valve that is designed to meet the rigorous performance requirements for a variety of space applications, such as micropropulsion, in-situ chemical analysis of other planets, or micro-fluidics experiments in micro-gravity. These systems often require very small yet reliable silicon valves with extremely low leak rates and long shelf lives. Also, they must survive the perils of space travel, which include unstoppable radiation, monumental shock and vibration forces, as well as extreme variations in temperature. Currently, no commercial MEMS valve meets these requirements. We at JPL are developing a piezoelectric MEMS valve that attempts to address the unique problem of space. We begin with proven configurations that may seem familiar. However, we have implemented some major design innovations that should produce a superior valve. The JPL micro-valve is expected to have an extremely low leak rate, limited susceptibility to particulates, vibration or radiation, as well as a wide operational temperature range.

The International Space Station: A Low-Earth Orbit (LEO) Test Bed for Advancements in Space and Environmental Medicine

Science.gov (United States)

Ruttley, Tara M.; Robinson, Julie A.

2010-01-01

Ground-based space analog projects such as the NASA Extreme Environment Mission Operations (NEEMO) can be valuable test beds for evaluation of experimental design and hardware feasibility before actually being implemented on orbit. The International Space Station (ISS) is an closed-system laboratory that orbits 240 miles above the Earth, and is the ultimate extreme environment. Its inhabitants spend hours performing research that spans from fluid physics to human physiology, yielding results that have implications for Earth-based improvements in medicine and health, as well as those that will help facilitate the mitigation of risks to the human body associated with exploration-class space missions. ISS health and medical experiments focus on pre-flight and in-flight prevention, in-flight treatment, and postflight recovery of health problems associated with space flight. Such experiments include those on enhanced medical monitoring, bone and muscle loss prevention, cardiovascular health, immunology, radiation and behavior. Lessons learned from ISS experiments may not only be applicable to other extreme environments that face similar capability limitations, but also serve to enhance standards of care for everyday use on Earth.

Computational discovery of extremal microstructure families

Science.gov (United States)

Chen, Desai; Skouras, Mélina; Zhu, Bo; Matusik, Wojciech

2018-01-01

Modern fabrication techniques, such as additive manufacturing, can be used to create materials with complex custom internal structures. These engineered materials exhibit a much broader range of bulk properties than their base materials and are typically referred to as metamaterials or microstructures. Although metamaterials with extraordinary properties have many applications, designing them is very difficult and is generally done by hand. We propose a computational approach to discover families of microstructures with extremal macroscale properties automatically. Using efficient simulation and sampling techniques, we compute the space of mechanical properties covered by physically realizable microstructures. Our system then clusters microstructures with common topologies into families. Parameterized templates are eventually extracted from families to generate new microstructure designs. We demonstrate these capabilities on the computational design of mechanical metamaterials and present five auxetic microstructure families with extremal elastic material properties. Our study opens the way for the completely automated discovery of extremal microstructures across multiple domains of physics, including applications reliant on thermal, electrical, and magnetic properties. PMID:29376124

Extreme events and predictability of catastrophic failure in composite materials and in the Earth

Science.gov (United States)

Main, I.; Naylor, M.

2012-05-01

Despite all attempts to isolate and predict extreme earthquakes, these nearly always occur without obvious warning in real time: fully deterministic earthquake prediction is very much a `black swan'. On the other hand engineering-scale samples of rocks and other composite materials often show clear precursors to dynamic failure under controlled conditions in the laboratory, and successful evacuations have occurred before several volcanic eruptions. This may be because extreme earthquakes are not statistically special, being an emergent property of the process of dynamic rupture. Nevertheless, probabilistic forecasting of event rate above a given size, based on the tendency of earthquakes to cluster in space and time, can have significant skill compared to say random failure, even in real-time mode. We address several questions in this debate, using examples from the Earth (earthquakes, volcanoes) and the laboratory, including the following. How can we identify `characteristic' events, i.e. beyond the power law, in model selection (do dragon-kings exist)? How do we discriminate quantitatively between stationary and non-stationary hazard models (is a dragon likely to come soon)? Does the system size (the size of the dragon's domain) matter? Are there localising signals of imminent catastrophic failure we may not be able to access (is the dragon effectively invisible on approach)? We focus on the effect of sampling effects and statistical uncertainty in the identification of extreme events and their predictability, and highlight the strong influence of scaling in space and time as an outstanding issue to be addressed by quantitative studies, experimentation and models.

Fault Diagnosis for Engine Based on Single-Stage Extreme Learning Machine

Directory of Open Access Journals (Sweden)

Fei Gao

2016-01-01

Full Text Available Single-Stage Extreme Learning Machine (SS-ELM is presented to dispose of the mechanical fault diagnosis in this paper. Based on it, the traditional mapping type of extreme learning machine (ELM has been changed and the eigenvectors extracted from signal processing methods are directly regarded as outputs of the network’s hidden layer. Then the uncertainty that training data transformed from the input space to the ELM feature space with the ELM mapping and problem of the selection of the hidden nodes are avoided effectively. The experiment results of diesel engine fault diagnosis show good performance of the SS-ELM algorithm.

The near-term prediction of drought and flooding conditions in the northeastern United States based on extreme phases of AMO and NAO

Science.gov (United States)

Berton, Rouzbeh; Driscoll, Charles T.; Adamowski, Jan F.

2017-10-01

frequency of wet, average, and dry discharge conditions with regards to the extreme phases of AMO and NAO. While the function was decaying, the tail asymptotically merged into and stabilized at the theoretical probability of the event. As the basin scale increased, the probability of wet, average, and dry discharge conditions decreased. The Merrimack River watershed will most likely experience greater than average discharge as its extreme condition, therefore development should be avoided on flood plains. Furthermore, the current reservoir storage capacity in the Merrimack should be improved in order to accommodate excess water input and minimize flood damage. Future research should target changes in the magnitude and timing of high discharge events in order to develop adaptation strategies for aging hydraulic infrastructure in the region.

Arctic sea ice, Eurasia snow, and extreme winter haze in China.

Science.gov (United States)

Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho

2017-03-01

The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction.

Insertion sequences enrichment in extreme Red sea brine pool vent

KAUST Repository

Elbehery, Ali H. A.

2016-12-03

Mobile genetic elements are major agents of genome diversification and evolution. Limited studies addressed their characteristics, including abundance, and role in extreme habitats. One of the rare natural habitats exposed to multiple-extreme conditions, including high temperature, salinity and concentration of heavy metals, are the Red Sea brine pools. We assessed the abundance and distribution of different mobile genetic elements in four Red Sea brine pools including the world’s largest known multiple-extreme deep-sea environment, the Red Sea Atlantis II Deep. We report a gradient in the abundance of mobile genetic elements, dramatically increasing in the harshest environment of the pool. Additionally, we identified a strong association between the abundance of insertion sequences and extreme conditions, being highest in the harshest and deepest layer of the Red Sea Atlantis II Deep. Our comparative analyses of mobile genetic elements in secluded, extreme and relatively non-extreme environments, suggest that insertion sequences predominantly contribute to polyextremophiles genome plasticity.

A Coupled Fixed Point Theorem in Fuzzy Metric Space Satisfying ϕ-Contractive Condition

Directory of Open Access Journals (Sweden)

B. D. Pant

2013-01-01

Full Text Available The intent of this paper is to prove a coupled fixed point theorem for two pairs of compatible and subsequentially continuous (alternately subcompatible and reciprocally continuous mappings, satisfying ϕ-contractive conditions in a fuzzy metric space. We also furnish some illustrative examples to support our results.

On a nonlinear integrodifferential evolution inclusion with nonlocal initial conditions in Banach spaces

Directory of Open Access Journals (Sweden)

Zuomao Yan

2012-01-01

Full Text Available In this paper, we discuss the existence results for a class of nnlinear integrodifferential evolution inclusions with nonlocal initial conditions in Banach spaces. Our results are based on a fixed point theorem for condensing maps due to Martelli and the resolvent operators combined with approximation techniques.

Assessment extreme hydrometeorological conditions in the Gulf of Bothnia, the Baltic Sea

Science.gov (United States)

Dvornikov, Anton; Martyanov, Stanislav; Ryabchenko, Vladimir; Eremina, Tatjana; Isaev, Alexey; Sein, Dmitry

2017-04-01

Extreme hydrometeorological conditions in the Gulf of Bothnia, the Baltic Sea, are estimated paying a special attention to the area of the future construction of nuclear power plant (NPP) "Hanhikivi-1" (24° 16' E, 64° 32' N). To produce these estimates, long-term observations and results from numerical models of water and ice circulation and wind waves are used. It is estimated that the average annual air temperature in the vicinity of the station is +3° C, summer and winter extreme temperature is equal to 33.3° C and -41.5° C, respectively. Model calculations of wind waves have shown that the most dangerous (in terms of the generation of wind waves in the NPP area) is a north-west wind with the direction of 310°. The maximum height of the waves in the Gulf of Bothnia near the NPP for this wind direction with wind velocity of 10 m/s is 1.2-1.4 m. According to the model estimates, the highest possible level of the sea near the NPP is 248 cm, the minimum level, -151 cm, respectively for the western and eastern winds. These estimates are in good agreement with observations on the sea level for the period 1922-2015 at the nearest hydrometeorological station Raahe (Finland). In order to assess the likely impact of the NPP on the marine environment numerical experiments for the cold (2010) and warm year (2014) have been carried out. These calculations have shown that permanent release of heat into the marine environment from the operating NPP for the cold year (2010) will increase the temperature in the upper layer of 0-250m zone by 10°C in winter - spring and by 8°C in summer - early autumn, and in the bottom layer of 0-250m zone by 5°C in winter - spring and 3°C in summer - early autumn. For the warm year (2014), these temperature changes are smaller. Ice cover in both cases will disappear in two - kilometer vicinity of the NPP. These effects should be taken into account when assessing local climate changes in the future

Area spectrum of extremal Reissner-Nordstroem black holes from quasinormal modes

International Nuclear Information System (INIS)

Setare, M.R.

2004-01-01

Using the quasinormal mode frequency of extremal Reissner-Nordstroem black holes, we obtain the area spectrum for these types of black holes. We show that the area and entropy black hole horizon are equally spaced. Our results for the spacing of the area spectrum differ from that for Schwarzschild black holes

Evolution of self-organization in nano-structured PVD coatings under extreme tribological conditions

Energy Technology Data Exchange (ETDEWEB)

Fox-Rabinovich, G., E-mail: gfox@mcmaster.ca [Department of Mechanical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7 (Canada); Kovalev, A. [Surface Phenomena Researches Group, CNIICHERMET, 9/23, 2-nd Baumanskaya Street, Moscow 105005 (Russian Federation); Aguirre, M.H. [Laboratory of Advanced Microscopy, Institute of Nanoscience of Aragón, University of Zaragoza, 50018 Zaragoza (Spain); Yamamoto, K. [Materials Research Laboratory, Kobe Steel Ltd, 1-5-5 Takatsuda-dai, Nishi-ku, Kobe 651-2271, Hyogo (Japan); Veldhuis, S. [Department of Mechanical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7 (Canada); Gershman, I. [All-Russian Railway Research Institute, 10 Third Mytishchinskaya Street, Moscow 29851 (Russian Federation); Rashkovskiy, A. [Surface Phenomena Researches Group, CNIICHERMET, 9/23, 2-nd Baumanskaya Street, Moscow 105005 (Russian Federation); Endrino, J.L. [Albengoa Research, Energia Solar 1, Palmas Altas, Seville 41014 (Spain); Beake, B. [Micro Materials Limited, Willow House, Yale Business Village, Ellice Way, Wrexham LL13 7YL (United Kingdom); Dosbaeva, G. [Department of Mechanical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7 (Canada); Wainstein, D. [Surface Phenomena Researches Group, CNIICHERMET, 9/23, 2-nd Baumanskaya Street, Moscow 105005 (Russian Federation); Yuan, Junifeng; Bunting, J.W. [Department of Mechanical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7 (Canada)

2014-04-01

Highlights: • The evolution of self-organization under extreme frictional conditions has been studied. • Comprehensive characterization of the tribo-films was made using various surface analytical techniques. • During the running-in stage, mullite tribo-ceramics predominate on the surface of the nano-multilayer coating, establishing a functional hierarchy within the layer of tribo-films. • It is possible to control tribo-film evolution during self-organization by means of an increase in structural complexity and the non-equilibrium state of the surface engineered layer. - Abstract: The evolution of the self-organization process where dissipative structures are formed under the extreme frictional conditions associated with high performance dry machining of hardened steels has been studied in detail. The emphasis was on the progressive studies of surface transformations within multilayer and monolayer TiAlCrSiYN-based PVD coatings during the running-in stage of wear when self-organization process occurs. The coating layer was characterized by high resolution electron energy-loss spectroscopy (HREELS). It is shown that the nano-multilayer coating possesses higher non-equilibrium structure in comparison to the monolayer. Comprehensive studies of the tribo-films (dissipative structures) formed on the friction surface were made using a number of advanced surface characterization techniques such as X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure (XANES). The data obtained for the tribo-films was combined with the detailed TEM studies of the structural and phase transformations within the underlying coating layer. This data was related to the micro-mechanical characteristics of the coating layer and its wear resistance. It was demonstrated that the evolution of the self-organization process is strongly controlled by the characteristics of the tribo-films formed at different stages of the wear process. Within running-in stage (after

Final Report for Project. Quark matter under extreme conditions

Energy Technology Data Exchange (ETDEWEB)

Incera, Vivian [Univ. of Texas, El Paso, TX (United States); Ferrer, Efrain [Univ. of Texas, El Paso, TX (United States)

2015-12-31

The results obtained in the two years of the grant have served to shine new light on several important questions about the phases of quantum chromodynamics (QCD) under extreme conditions that include quark matter at high density, as well quark-gluon plasma at high temperatures, both in the presence of strong magnetic fields. The interest in including an external magnetic field on these studies is motivated by the generation of large magnetic fields in off-central heavy-ion collisions and by their common presence in astrophysical compact objects, the two scenarios where the physics of quark matter becomes relevant. The tasks carried out in this DOE project led us, among other things, to discover the first connection between the physics of very dense quark matter and novel materials as for instance topological insulators and Weyl semimetals; they allowed us to find a physical explanation for and a solution to a standing puzzle in the apparent effect of a magnetic field on the critical temperature of the QCD chiral transition; and they led us to establish by the first time that the core of the observed two-solar-mass neutron stars could be made up of quark matter in certain inhomogeneous chiral phases in a magnetic field and that this was consistent with current astrophysical observations. A major goal established by the Nuclear Science Advisory committee in its most recent report “Reaching for the Horizon” has been “to truly understand how nuclei and strongly interacting matter in all its forms behave and can predict their behavior in new settings.” The results found in this DOE project have all contributed to address this goal, and thus they are important for advancing fundamental knowledge in the area of nuclear physics and for enhancing our understanding of the role of strong magnetic fields in the two settings where they are most relevant, neutron stars and heavy-ion collisions.

Final Report for Project. Quark matter under extreme conditions

International Nuclear Information System (INIS)

Incera, Vivian; Ferrer, Efrain

2015-01-01

The results obtained in the two years of the grant have served to shine new light on several important questions about the phases of quantum chromodynamics (QCD) under extreme conditions that include quark matter at high density, as well quark-gluon plasma at high temperatures, both in the presence of strong magnetic fields. The interest in including an external magnetic field on these studies is motivated by the generation of large magnetic fields in off-central heavy-ion collisions and by their common presence in astrophysical compact objects, the two scenarios where the physics of quark matter becomes relevant. The tasks carried out in this DOE project led us, among other things, to discover the first connection between the physics of very dense quark matter and novel materials as for instance topological insulators and Weyl semimetals; they allowed us to find a physical explanation for and a solution to a standing puzzle in the apparent effect of a magnetic field on the critical temperature of the QCD chiral transition; and they led us to establish by the first time that the core of the observed two-solar-mass neutron stars could be made up of quark matter in certain inhomogeneous chiral phases in a magnetic field and that this was consistent with current astrophysical observations. A major goal established by the Nuclear Science Advisory committee in its most recent report 'Reaching for the Horizon' has been 'to truly understand how nuclei and strongly interacting matter in all its forms behave and can predict their behavior in new settings.' The results found in this DOE project have all contributed to address this goal, and thus they are important for advancing fundamental knowledge in the area of nuclear physics and for enhancing our understanding of the role of strong magnetic fields in the two settings where they are most relevant, neutron stars and heavy-ion collisions.

The impact of extreme weather conditions on the life of settlers in the Central Russia in X - XVI centuries

Science.gov (United States)

Graves, Irina; Nizovtsev, Viacheslav; Erman, Natalia

2017-04-01

A special place in the reconstruction of climate dynamics takes an analysis of extraordinary meteorological phenomena. These extreme weather events in the first place impact the functioning of, the rhythm and dynamics of the landscapes and determine not only the features of economy, but also certain aspects of historical development. In the analysis of primary chronicles and published data, along with the direct climatic characteristics (hot, warm, cold, wet, dry, etc.) a lot of attention was paid to abnormal (extreme) natural phenomena and indirect indications of climate variability (floods, crop failures, hunger years, epidemics, etc.). As a result, tables were compiled reflecting climatic basic characteristics and extremes for each year since 900 BC. X-XI centuries was a period of minor climatic optimum - the climate was warmer and drier than the modern one. In addition to higher temperatures (up to 1-3C above than mordern), during this period there were no severe winters. A small amount of summer rainfall has led to a reduction in the number of small water reservoirs and flooding rivers. This is evidenced by Slavic settlements on floodplains of a number of rivers in the Moscow region. It is in this favorable climatic time the way "from the Vikings to the Greeks" was open. Catastrophic natural events had a minimum repeatability. For example, during the X century the Russian chronicles mentioned 41 extreme event, but for the XIII century - 102. Most of the villages and towns were located on the low floodplain terraces of rivers. The main farmland was concentrated there as well. In the "period of contrasts" (XIII - XIV centuries) there was an increase of intra-seasonal climate variability, humidity and widespread reduction in summer temperatures by 1-2C. The number of extreme weather events increased: cold prolonged winters, long rains in summers, cold weather returns in the early summer, early frosts in late summer - early autumn. Such conditions often

Can Concentration - Discharge Relationships Diagnose Material Source During Extreme Events?

Science.gov (United States)

Karwan, D. L.; Godsey, S.; Rose, L.

2017-12-01

Floods can carry >90% of the basin material exported in a given year as well as alter flow pathways and material sources. In turn, sediment and solute fluxes can increase flood damages and negatively impact water quality and integrate physical and chemical weathering of landscapes and channels. Concentration-discharge (C-Q) relationships are used to both describe export patterns as well as compute them. Metrics for describing C-Q patterns and inferring their controls are vulnerable to infrequent sampling that affects how C-Q relationships are interpolated and interpreted. C-Q relationships are typically evaluated from multiple samples, but because hydrological extremes are rare, data are often unavailable for extreme events. Because solute and sediment C-Q relationships likely respond to changes in hydrologic extremes in different ways, there is a pressing need to define their behavior under extreme conditions, including how to properly sample to capture these patterns. In the absence of such knowledge, improving load estimates in extreme floods will likely remain difficult. Here we explore the use of C-Q relationships to determine when an event alters a watershed system such that it enters a new material source/transport regime. We focus on watersheds with sediment and discharge time series include low-frequency and/or extreme events. For example, we compare solute and sediment patterns in White Clay Creek in southeastern Pennsylvania across a range of flows inclusive of multiple hurricanes for which we have ample ancillary hydrochemical data. TSS is consistently mobilized during high flow events, even during extreme floods associated with hurricanes, and sediment fingerprinting indicates different sediment sources, including in-channel remobilization and landscape erosion, are active at different times. In other words, TSS mobilization in C-Q space is not sensitive to the source of material being mobilized. Unlike sediments, weathering solutes in this watershed

Uncertainties in extreme precipitation under climate change conditions

DEFF Research Database (Denmark)

Sunyer Pinya, Maria Antonia

of adaptation strategies, but these changes are subject to uncertainties. The focus of this PhD thesis is the quantification of uncertainties in changes in extreme precipitation. It addresses two of the main sources of uncertainty in climate change impact studies: regional climate models (RCMs) and statistical...... downscaling methods (SDMs). RCMs provide information on climate change at the regional scale. SDMs are used to bias-correct and downscale the outputs of the RCMs to the local scale of interest in adaptation strategies. In the first part of the study, a multi-model ensemble of RCMs from the European ENSEMBLES...... project was used to quantify the uncertainty in RCM projections over Denmark. Three aspects of the RCMs relevant for the uncertainty quantification were first identified and investigated. These are: the interdependency of the RCMs; the performance in current climate; and the change in the performance...

Near horizon structure of extremal vanishing horizon black holes

Directory of Open Access Journals (Sweden)

S. Sadeghian

2015-11-01

Full Text Available We study the near horizon structure of Extremal Vanishing Horizon (EVH black holes, extremal black holes with vanishing horizon area with a vanishing one-cycle on the horizon. We construct the most general near horizon EVH and near-EVH ansatz for the metric and other fields, like dilaton and gauge fields which may be present in the theory. We prove that (1 the near horizon EVH geometry for generic gravity theory in generic dimension has a three dimensional maximally symmetric subspace; (2 if the matter fields of the theory satisfy strong energy condition either this 3d part is AdS3, or the solution is a direct product of a locally 3d flat space and a d−3 dimensional part; (3 these results extend to the near horizon geometry of near-EVH black holes, for which the AdS3 part is replaced with BTZ geometry. We present some specific near horizon EVH geometries in 3, 4 and 5 dimensions for which there is a classification. We also briefly discuss implications of these generic results for generic (gauged supergravity theories and also for the thermodynamics of near-EVH black holes and the EVH/CFT proposal.

Automated Precision Maneuvering and Landing in Extreme and Constrained Environments

Data.gov (United States)

National Aeronautics and Space Administration — Autonomous, precise maneuvering and landing in extreme and constrained environments is a key enabler for future NASA missions. Missions to map the interior of a...

A single pH fluorescent probe for biosensing and imaging of extreme acidity and extreme alkalinity.

Science.gov (United States)

Chao, Jian-Bin; Wang, Hui-Juan; Zhang, Yong-Bin; Li, Zhi-Qing; Liu, Yu-Hong; Huo, Fang-Jun; Yin, Cai-Xia; Shi, Ya-Wei; Wang, Juan-Juan

2017-07-04

A simple tailor-made pH fluorescent probe 2-benzothiazole (N-ethylcarbazole-3-yl) hydrazone (Probe) is facilely synthesized by the condensation reaction of 2-hydrazinobenzothiazole with N-ethylcarbazole-3-formaldehyde, which is a useful fluorescent probe for monitoring extremely acidic and alkaline pH, quantitatively. The pH titrations indicate that Probe displays a remarkable emission enhancement with a pK a of 2.73 and responds linearly to minor pH fluctuations within the extremely acidic range of 2.21-3.30. Interestingly, Probe also exhibits strong pH-dependent characteristics with pK a 11.28 and linear response to extreme-alkalinity range of 10.41-12.43. In addition, Probe shows a large Stokes shift of 84 nm under extremely acidic and alkaline conditions, high selectivity, excellent sensitivity, good water-solubility and fine stability, all of which are favorable for intracellular pH imaging. The probe is further successfully applied to image extremely acidic and alkaline pH values fluctuations in E. coli cells. Copyright © 2017 Elsevier B.V. All rights reserved.

Polymer Flip Chips with Extreme Temperature Stability in Space, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The objective of the proposed SBIR Phase I program is to develop highly thermally and electrically conductive nanocomposites for space-based flip chips for...

Modern education of future teacher of physical culture in the conditions of informatization of educational space

Directory of Open Access Journals (Sweden)

Dragnev Y.V.

2012-03-01

Full Text Available The informatization of the educational space is determined by the organizational, scientific-technical, educational processes, which update the creation of the unified information and educational space for the comprehensive use of information technologies in educational process of a future teacher of physical culture at the higher school. Stated that the integration and expansion of the educational space of the orients the higher school not only in the preparation of the literate student on the issues of information culture, but also to help the younger generation in the mastery of basic social abilities and skills in conditions of informatization of the educational space.

Enhancing the Extreme Climate Index (ECI) to monitor climate extremes for an index-based insurance scheme across Africa

Science.gov (United States)

Helmschrot, J.; Malherbe, J.; Chamunorwa, M.; Muthige, M.; Petitta, M.; Calmanti, S.; Cucchi, M.; Syroka, J.; Iyahen, E.; Engelbrecht, F.

2017-12-01

Climate services are a key component of National Adaptation Plan (NAP) processes, which require the analysis of current climate conditions, future climate change scenarios and the identification of adaptation strategies, including the capacity to finance and implement effective adaptation options. The Extreme Climate Facility (XCF) proposed by the African Risk Capacity (ARC) developed a climate index insurance scheme, which is based on the Extreme Climate Index (ECI): an objective, multi-hazard index capable of tracking changes in the frequency or magnitude of extreme weather events, thus indicating possible shifts to a new climate regime in various regions. The main hazards covered by ECI are extreme dry, wet and heat events, with the possibility of adding other region-specific risk events. The ECI is standardized across broad geographical regions, so that extreme events occurring under different climatic regimes in Africa can be compared. Initially developed by an Italian company specialized in Climate Services, research is now conducted at the CSIR and SASSCAL, to verify and further develop the ECI for application in southern African countries, through a project initiated by the World Food Programme (WFP) and ARC. The paper will present findings on the most appropriate definitions of extremely wet and dry conditions in Africa, in terms of their impact across a multitude of sub-regional climates of the African continent. Findings of a verification analysis of the ECI, as determined through vegetation monitoring data and the SASSCAL weather station network will be discussed. Changes in the ECI under climate change will subsequently be projected, using detailed regional projections generated by the CSIR and through the Coordinated Regional Downscaling Experiment (CORDEX). This work will be concluded by the development of a web-based climate service informing African Stakeholders on climate extremes.

Digitally intensive DC-DC converter for extreme space environments, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The Space Micro-Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

Nonextreme and ultraextreme domain walls and their global space-times

International Nuclear Information System (INIS)

Cvetic, M.; Griffies, S.; Soleng, H.H.

1993-01-01

Nonextreme walls (bubbles with two insides) and ultraextreme walls (bubbles of false vacuum decay) are discussed. Their respective energy densities are higher and lower than that of the corresponding extreme (supersymmetric), planar domain wall. These singularity free space-times exhibit nontrivial causal structure analogous to certain nonextreme black holes. We focus on anti--de Sitter--Minkowski walls and comment on Minkowski-Minkowski walls with trivial extreme limit, as well as walls adjacent to de Sitter space-times with no extreme limit

Chemical Engineering in Space

Science.gov (United States)

Lobmeyer, Dennis A.; Meneghelli, Barry; Steinrock, Todd (Technical Monitor)

2001-01-01

The aerospace industry has long been perceived as the domain of both physicists and mechanical engineers. This perception has endured even though the primary method of providing the thrust necessary to launch a rocket into space is chemical in nature. The chemical engineering and chemistry personnel behind the systems that provide access to space have labored in the shadows of the physicists and mechanical engineers. As exploration into the cosmos moves farther away from Earth, there is a very distinct need for new chemical processes to help provide the means for advanced space exploration. The state of the art in launch systems uses chemical propulsion systems, primarily liquid hydrogen and liquid oxygen, to provide the energy necessary to achieve orbit. As we move away from Earth, there are additional options for propulsion. Unfortunately, few of these options can compare to the speed or ease of use provided by the chemical propulsion agents. It is with great care and significant cost that gaseous compounds such as hydrogen and oxygen are liquefied and become dense enough to use for rocket fuel. These low-temperature liquids fall within a specialty area known as cryogenics. Cryogenics, the science and art of producing cold operating conditions for use on Earth, in orbit, or on some other nonterrestrial body, has become increasingly important to our ability to travel within our solar system. The production of cryogenic fuels and the long-term storage of these fluids are necessary for travel. As our explorations move farther away from Earth, we need to address how to produce the necessary fuels to make a round-trip. The cost and the size of these expeditions are extreme at best. If we take everything necessary for our survival for the round-trip, we invalidate any chance of travel in the near future. As with the early explorers on Earth, we need to harvest much of our energy and our life support from the celestial bodies. The in situ production of these energy

Perspectives of biotechnologies based on dormancy phenomenon for space researches

Science.gov (United States)

Alekseev, V.; Sychev, V.; Layus, D.; Levinsky, M.; Novikova, N.; Zakhodnova, T.

Long term space missions will require a renewable source of food and an efficient method to recycle oxygen Plants especially aquatic micro algae provide an obvious solution to these problems However long duration plant growth and reproduction in space that is necessary for transportation of a control ecological life support system CELSS from Earth to other planets are problematic The introduction of heterotrophs in space CELSS is a more formidable problem as the absence of gravity creates additional difficulties for their life Dormancy phenomenon protected a great many animals and plants in harsh environmental conditions within a special resting phases of life cycle lasting from months up to hundred years This phenomenon can be quite perspective as a tool to overcome difficulties with CELSS transportation in space missions Cryptobiotic stages of microbes fungi unicellular algae and protists can survive in open space conditions that is important for interplanetary quarantine and biological security inside spacecraft Searching for life outside the Earth at such planet like Mars with extremely variable environment should be oriented on dormancy as crucial phases of a life cycle in such organisms Five major research programs aimed on study dormancy phenomenon for exobiology purposes and creation of new biotechnologies are discussed List of species candidate components of CELSS with dormancy in their life cycle used in space experiments at the Russian segment of International Space Station now includes 26 species from bacteria to fish The

Solving Component Structural Dynamic Failures Due to Extremely High Frequency Structural Response on the Space Shuttle Program

Science.gov (United States)

Frady, Greg; Nesman, Thomas; Zoladz, Thomas; Szabo, Roland

2010-01-01

For many years, the capabilities to determine the root-cause failure of component failures have been limited to the analytical tools and the state of the art data acquisition systems. With this limited capability, many anomalies have been resolved by adding material to the design to increase robustness without the ability to determine if the design solution was satisfactory until after a series of expensive test programs were complete. The risk of failure and multiple design, test, and redesign cycles were high. During the Space Shuttle Program, many crack investigations in high energy density turbomachines, like the SSME turbopumps and high energy flows in the main propulsion system, have led to the discovery of numerous root-cause failures and anomalies due to the coexistences of acoustic forcing functions, structural natural modes, and a high energy excitation, such as an edge tone or shedding flow, leading the technical community to understand many of the primary contributors to extremely high frequency high cycle fatique fluid-structure interaction anomalies. These contributors have been identified using advanced analysis tools and verified using component and system tests during component ground tests, systems tests, and flight. The structural dynamics and fluid dynamics communities have developed a special sensitivity to the fluid-structure interaction problems and have been able to adjust and solve these problems in a time effective manner to meet budget and schedule deadlines of operational vehicle programs, such as the Space Shuttle Program over the years.

Modeling of Complex Material Systems in Extreme Environments for Space Technology

Data.gov (United States)

National Aeronautics and Space Administration — Among the many enabling technologies of space research is the design of materials which are stable in the environments of interest for a given application. At the...

Digitally intensive DC-DC converter for extreme space environments, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The Space Micro –Arizona State University (ASU) team will develop an all-digitally controlled, wide temperature range point-of-load switch-mode DC-DC regulator core...

Imaging of neuro-cognitive performance in extreme Environments—A (p)review

Science.gov (United States)

Schneider, Stefan; Bubeev, Juri A.; Choukèr, Alexander; Morukov, Boris; Johannes, Bernd; Strüder, Heiko K.

2012-12-01

Living in extreme environments is accompanied by a number of stressors, which can be classified either as physiological stressors (e.g. microgravity, missing sunlight) or psychological stressors (e.g. confinement). From earth bound studies a negative impact of stress on mental health and cognitive performance is well known and both factors might impair mission success and mission safety during longer inhabitation of space. Accordingly there is the need to identify adequate countermeasures. Nevertheless causal research of neuro-cognitive impairments in space remains speculative due to missing possibilities of brain imaging. Furthermore the reliability of current psychological tests used to assess and monitor cognitive performance in extreme environments seems to be vulnerable due to a lack of compliance. With on-going plans of international space agencies to send people to moon and/or mars, this manuscript aims to summarize and review research attempts of the past two decades and to identify methodological shortcomings. Finally, following the guideline that research has no legacy for its own but must serve the self-concept and well-being of man, this manuscript presents a number of recommendations to enhance future neuro-cognitive research in extreme environments. A deeper insight into neuro-cognitive coherence is not only desirable to understand the effects of stress on mental health, which seems to be a major issue for our current society, and to develop adequate countermeasures but will also help to maintain and improve mission success and mission safety in manned space flight.

Wind simulation for extreme and fatigue loads

Energy Technology Data Exchange (ETDEWEB)

Nielsen, M.; Larsen, G.C.; Mann, J.; Ott, S.; Hansen, K.S.; Pedersen, B.J.

2004-01-01

Measurements of atmospheric turbulence have been studied and found to deviate from a Gaussian process, in particular regarding the velocity increments over small time steps, where the tails of the pdf are exponential rather than Gaussian. Principles for extreme event counting and the occurrence of cascading events are presented. Empirical extreme statistics agree with Rices exceedence theory, when it is assumed that the velocity and its time derivative are independent. Prediction based on the assumption that the velocity is a Gaussian process underpredicts the rate of occurrence of extreme events by many orders of magnitude, mainly because the measured pdf is non-Gaussian. Methods for simulation of turbulent signals have been developed and their computational efficiency are considered. The methods are applicable for multiple processes with individual spectra and probability distributions. Non-Gaussian processes are simulated by the correlation-distortion method. Non-stationary processes are obtained by Bezier interpolation between a set of stationary simulations with identical random seeds. Simulation of systems with some signals available is enabled by conditional statistics. A versatile method for simulation of extreme events has been developed. This will generate gusts, velocity jumps, extreme velocity shears, and sudden changes of wind direction. Gusts may be prescribed with a specified ensemble average shape, and it is possible to detect the critical gust shape for a given construction. The problem is formulated as the variational problem of finding the most probable adjustment of a standard simulation of a stationary Gaussian process subject to relevant event conditions, which are formulated as linear combination of points in the realization. The method is generalized for multiple correlated series, multiple simultaneous conditions, and 3D fields of all velocity components. Generalization are presented for a single non-Gaussian process subject to relatively

Liquid Water Restricts Habitability in Extreme Deserts

Science.gov (United States)

Cockell, Charles S.; Brown, Sarah; Landenmark, Hanna; Samuels, Toby; Siddall, Rebecca; Wadsworth, Jennifer

2017-04-01

Liquid water is a requirement for biochemistry, yet under some circumstances it is deleterious to life. Here, we show that liquid water reduces the upper temperature survival limit for two extremophilic photosynthetic microorganisms (Gloeocapsa and Chroococcidiopsis spp.) by greater than 40°C under hydrated conditions compared to desiccated conditions. Under hydrated conditions, thermal stress causes protein inactivation as shown by the fluorescein diacetate assay. The presence of water was also found to enhance the deleterious effects of freeze-thaw in Chroococcidiopsis sp. In the presence of water, short-wavelength UV radiation more effectively kills Gloeocapsa sp. colonies, which we hypothesize is caused by factors including the greater penetration of UV radiation into hydrated colonies compared to desiccated colonies. The data predict that deserts where maximum thermal stress or irradiation occurs in conjunction with the presence of liquid water may be less habitable to some organisms than more extreme arid deserts where organisms can dehydrate prior to being exposed to these extremes, thus minimizing thermal and radiation damage. Life in extreme deserts is poised between the deleterious effects of the presence and the lack of liquid water.

Surgical Space Conditions During Low-Pressure Laparoscopic Cholecystectomy with Deep Versus Moderate Neuromuscular Blockade

DEFF Research Database (Denmark)

Staehr-Rye, Anne K; Rasmussen, Lars S.; Rosenberg, Jacob

2014-01-01

: In this assessor-blinded study, 48 patients undergoing elective laparoscopic cholecystectomy were administered rocuronium for neuromuscular blockade and randomized to either deep neuromuscular blockade (rocuronium bolus plus infusion maintaining a posttetanic count 0-1) or moderate neuromuscular blockade...... (rocuronium repeat bolus only for inadequate surgical conditions with spontaneous recovery of neuromuscular function). Patients received anesthesia with propofol, remifentanil, and rocuronium. The primary outcome was the proportion of procedures with optimal surgical space conditions (assessed by the surgeon...

Integrated Systems Health Management for Space Exploration

Science.gov (United States)

Uckun, Serdar

2005-01-01

Integrated Systems Health Management (ISHM) is a system engineering discipline that addresses the design, development, operation, and lifecycle management of components, subsystems, vehicles, and other operational systems with the purpose of maintaining nominal system behavior and function and assuring mission safety and effectiveness under off-nominal conditions. NASA missions are often conducted in extreme, unfamiliar environments of space, using unique experimental spacecraft. In these environments, off-nominal conditions can develop with the potential to rapidly escalate into mission- or life-threatening situations. Further, the high visibility of NASA missions means they are always characterized by extraordinary attention to safety. ISHM is a critical element of risk mitigation, mission safety, and mission assurance for exploration. ISHM enables: In-space maintenance and repair; a) Autonomous (and automated) launch abort and crew escape capability; b) Efficient testing and checkout of ground and flight systems; c) Monitoring and trending of ground and flight system operations and performance; d) Enhanced situational awareness and control for ground personnel and crew; e) Vehicle autonomy (self-sufficiency) in responding to off-nominal conditions during long-duration and distant exploration missions; f) In-space maintenance and repair; and g) Efficient ground processing of reusable systems. ISHM concepts and technologies may be applied to any complex engineered system such as transportation systems, orbital or planetary habitats, observatories, command and control systems, life support systems, safety-critical software, and even the health of flight crews. As an overarching design and operational principle implemented at the system-of-systems level, ISHM holds substantial promise in terms of affordability, safety, reliability, and effectiveness of space exploration missions.

Higher order magnetic modulation structures in rare earth metal, alloys and compounds under extreme conditions

International Nuclear Information System (INIS)

Kawano, S.

2003-01-01

Magnetic materials consisting of rare earth ions form modulation structures such as a helical or sinusoidal structure caused by the oscillating magnetic interaction between rare earth ions due to RKKY magnetic interaction. These modulation structures, in some cases, develop further to higher order modulation structures by additional modulations caused by higher order crystalline electric field, magnetic interactions such as spin-lattice interaction, external magnetic field and pressure. The higher order modulation structures are observed in a spin-slip structure or a helifan structure in Ho, and a tilt helix structure in a TbEr alloy. Paramagnetic ions originated from frustration generate many magnetic phases under applied external magnetic field. KUR neutron diffraction groups have performed the development and adjustment of high-pressure instruments and external magnetic fields for neutron diffraction spectrometers. The studies of 'neutron diffraction under extreme conditions' by the seven groups are described in this report. (Y. Kazumata)

Calculation of neutron fluence-to-dose conversion factors for extremities

International Nuclear Information System (INIS)

Stewart, R.D.; Harty, R.; McDonald, J.C.; Tanner, J.E.

1993-04-01

The Pacific Northwest Laboratory is developing a standard for the performance testing of personnel extremity dosimeters for the US Department of Energy. Part of this effort requires the calculation of neutron fluence-to-dose conversion factors for finger and wrist extremities. This study focuses on conversion factors for two types of extremity models: namely the polymethyl methacrylate (PMMA) phantom (as specified in the draft standard for performance testing of extremity dosimeters) and more realistic extremity models composed of tissue-and-bone. Calculations for each type of model are based on both bare and D 2 O-moderated 252 Cf sources. The results are then tabulated and compared with whole-body conversion factors. More appropriate energy-averaged quality factors for the extremity models have also been computed from the neutron fluence in 50 equally spaced energy bins with energies from 2.53 x 10 -8 to 15 MeV. Tabulated results show that conversion factors for both types of extremity phantom are 15 to 30% lower than the corresponcung whole-body phantom conversion factors for 252 Cf neutron sources. This difference in extremity and whole-body conversion factors is attributable to the proportionally smaller amount of back-scattering that occurs in the extremity phantoms compared with whole-body phantoms

Carving out humanitarian space

OpenAIRE

Jean-François Durieux; Sivanka Dhanapala

2008-01-01

Agencies working inside Myanmar to assist forcibly displacedpeople work within an extremely constricted operationalenvironment. Despite occasional glimmers of hope, carvingout sufficient humanitarian space to meet urgent needsremains an uphill struggle.

XBeach-G: a tool for predicting gravel barrier response to extreme storm conditions

Science.gov (United States)

Masselink, Gerd; Poate, Tim; McCall, Robert; Roelvink, Dano; Russell, Paul; Davidson, Mark

2014-05-01

Gravel beaches protect low-lying back-barrier regions from flooding during storm events and their importance to society is widely acknowledged. Unfortunately, breaching and extensive storm damage has occurred at many gravel sites and this is likely to increase as a result of sea-level rise and enhanced storminess due to climate change. Limited scientific guidance is currently available to provide beach managers with operational management tools to predict the response of gravel beaches to storms. The New Understanding and Prediction of Storm Impacts on Gravel beaches (NUPSIG) project aims to improve our understanding of storm impacts on gravel coastal environments and to develop a predictive capability by modelling these impacts. The NUPSIG project uses a 5-pronged approach to address its aim: (1) analyse hydrodynamic data collected during a proto-type laboratory experiment on a gravel beach; (2) collect hydrodynamic field data on a gravel beach under a range of conditions, including storm waves with wave heights up to 3 m; (3) measure swash dynamics and beach response on 10 gravel beaches during extreme wave conditions with wave heights in excess of 3 m; (4) use the data collected under 1-3 to develop and validate a numerical model to model hydrodynamics and morphological response of gravel beaches under storm conditions; and (5) develop a tool for end-users, based on the model formulated under (4), for predicting storm response of gravel beaches and barriers. The aim of this presentation is to present the key results of the NUPSIG project and introduce the end-user tool for predicting storm response on gravel beaches. The model is based on the numerical model XBeach, and different forcing scenarios (wave and tides), barrier configurations (dimensions) and sediment characteristics are easily uploaded for model simulations using a Graphics User Interface (GUI). The model can be used to determine the vulnerability of gravel barriers to storm events, but can also be

Extreme Geohazards: Reducing the Disaster Risk and Increasing Resilience

Science.gov (United States)

Plag, Hans-Peter; Stein, Seth; Brocklebank, Sean; Jules-Plag, Shelley; Marsh, Stuart; Campus, Paola

2013-04-01

Extreme geohazards have the potential to escalate the global sustainability crisis and put us close to the boundaries of the safe operating space for humanity. Exposure of human assets to geohazards has increased dramatically in recent decades, and the sensitivity of the built environment and the embedded socio-economic fabric have changed. We are putting the urban environment, including megacities, in harm's way. Paradoxically, innovation during recent decades, in particular, urban innovation, has increased the disaster risk and coupled this risk to the sustainability crisis. Only more innovation can reduce disaster risk and lead us out of the sustainability crisis. Extreme geohazards (volcanic eruptions, earthquakes, tsunamis) that occurred regularly throughout the last few millennia mostly did not cause major disasters because population density was low and the built environment was not sprawling into hazardous areas to the same extent as today. Similar extreme events today would cause unparalleled damage on a global scale and could worsen the sustainability crisis. Simulation of these extreme hazards under present conditions can help to assess the disaster risk. The Geohazards Community of Practice of the Group on Earth Observations (GEO) with support from the European Science Foundation is preparing a white paper assessing the contemporary disaster risks associated with extreme geohazards and developing a vision for science and society to engage in deliberations addressing this risk (see http://www.geohazcop.org/projects/extgeowp). Risk awareness and monitoring is highly uneven across the world, and this creates two kinds of problems. Firstly, potential hazards are much more closely monitored in wealthy countries than in the developing world. But the largest hazards are global in nature, and it is critical to get as much forewarning as possible to develop an effective response. The disasters and near-misses of the past show that adherence to scientific

WHAT CAN WE LEARN FROM THE “WATER BEARS” FOR THE ADHESION SYSTEMS USING IN SPACE APPLICATIONS?

Directory of Open Access Journals (Sweden)

Alexander E. Filippov

2015-12-01

Full Text Available Recent progress in space research and in particular appearance of complex movable constructions with a number of components exposed to the extreme conditions of open space causes a strong demand for development of new tribological and adhesion systems which are able to resist such conditions. In the last few years, many engineering solutions in the field of tribology and adhesion have been found based on “biomimetics approach” that is searching for ideas originally created by living nature and optimized during billions of years of natural selection. Surprisingly some of the living creatures are found to be optimized even for survival for a long time in the conditions of open space. Such ability is very promising from the point of view of development of new adhesives for future space applications. In this paper we discuss what we can learn in this context from the so-called “water bears” (tardigrades in a combination with some other features, already adopted to reversible technical adhesives from other animals, such as insects and Gecko lizards.

Operational early warning platform for extreme meteorological events

Science.gov (United States)

Mühr, Bernhard; Kunz, Michael

2015-04-01

Operational early warning platform for extreme meteorological events Most natural disasters are related to extreme weather events (e.g. typhoons); weather conditions, however, are also highly relevant for humanitarian and disaster relief operations during and after other natural disaster like earthquakes. The internet service "Wettergefahren-Frühwarnung" (WF) provides various information on extreme weather events, especially when these events are associated with a high potential for large damage. The main focus of the platform is on Central Europe, but major events are also monitored worldwide on a daily routine. WF provides high-resolution forecast maps for many weather parameters which allow detailed and reliable predictions about weather conditions during the next days in the affected areas. The WF service became operational in February 2004 and is part of the Center for Disaster Management and Risk Reduction Technology (CEDIM) since 2007. At the end of 2011, CEDIM embarked a new type of interdisciplinary disaster research termed as forensic disaster analysis (FDA) in near real time. In case of an imminent extreme weather event WF plays an important role in CEDIM's FDA group. It provides early and precise information which are always available and updated several times during a day and gives advice and assists with articles and reports on extreme events.

Impact of soil moisture on extreme maximum temperatures in Europe

Directory of Open Access Journals (Sweden)

Kirien Whan

2015-09-01

Full Text Available Land-atmosphere interactions play an important role for hot temperature extremes in Europe. Dry soils may amplify such extremes through feedbacks with evapotranspiration. While previous observational studies generally focused on the relationship between precipitation deficits and the number of hot days, we investigate here the influence of soil moisture (SM on summer monthly maximum temperatures (TXx using water balance model-based SM estimates (driven with observations and temperature observations. Generalized extreme value distributions are fitted to TXx using SM as a covariate. We identify a negative relationship between SM and TXx, whereby a 100 mm decrease in model-based SM is associated with a 1.6 °C increase in TXx in Southern-Central and Southeastern Europe. Dry SM conditions result in a 2–4 °C increase in the 20-year return value of TXx compared to wet conditions in these two regions. In contrast with SM impacts on the number of hot days (NHD, where low and high surface-moisture conditions lead to different variability, we find a mostly linear dependency of the 20-year return value on surface-moisture conditions. We attribute this difference to the non-linear relationship between TXx and NHD that stems from the threshold-based calculation of NHD. Furthermore the employed SM data and the Standardized Precipitation Index (SPI are only weakly correlated in the investigated regions, highlighting the importance of evapotranspiration and runoff for resulting SM. Finally, in a case study for the hot 2003 summer we illustrate that if 2003 spring conditions in Southern-Central Europe had been as dry as in the more recent 2011 event, temperature extremes in summer would have been higher by about 1 °C, further enhancing the already extreme conditions which prevailed in that year.

Lunar and planetary surface conditions advances in space science and technology

CERN Document Server

Weil, Nicholas A

1965-01-01

Lunar and Planetary Surface Conditions considers the inferential knowledge concerning the surfaces of the Moon and the planetary companions in the Solar System. The information presented in this four-chapter book is based on remote observations and measurements from the vantage point of Earth and on the results obtained from accelerated space program of the United States and U.S.S.R. Chapter 1 presents the prevalent hypotheses on the origin and age of the Solar System, followed by a brief description of the methods and feasibility of information acquisition concerning lunar and planetary data,

Motor Controller for Extreme Environments Based on SiGe, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The proposed innovation is a motor-control subsystem capable of operation in extreme environments, including those to be encountered on the Moon and Mars....

Art and Architectural Space

DEFF Research Database (Denmark)

Unterrainer, Walter

2014-01-01

art and architectural space museums and other exhibition spaces or how artists learn to love architects Over the last two decades, innumerable new museums, art galleries and other exhibition spaces have been built and opened all over the globe. The most extreme growth happened in China, where...... purpose of ´uniqueness´ often fail to be a ´home´, a large scale ´picture frame´ or a productive space for communicating art and even do not fulfil basic technical aspects in terms of a consistent indoor climate, optimized lighting or safety. The lecture will focus on inspiring examples of spaces for art...

Occupational ergonomics in space

Science.gov (United States)

Stramler, J.

1992-01-01

Ergonomics is often defined simply as the study of work. Related or synonymous terms include human factors, human engineering, engineering psychology, and others. Occupational ergonomics is a term that has been proposed to describe the study of the working environment, including the physical consequences resulting from having an improperly designed workplace. The routine space working environment presents some problems not found in the typical Earthbound workplace. These include radiation, intravehicular contamination/pollution, temperature extremes, impact with other objects, limited psychosocial relationships, sensory deprivation, and reduced gravity. These are important workplace considerations, and may affect astronauts either directly at work or at some point during their life as a result of their work under these conditions. Some of the major issues associated with each of these hazards are presented.

Gravo-Aeroelastic Scaling for Extreme-Scale Wind Turbines

Energy Technology Data Exchange (ETDEWEB)

Fingersh, Lee J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Loth, Eric [University of Virginia; Kaminski, Meghan [University of Virginia; Qin, Chao [University of Virginia; Griffith, D. Todd [Sandia National Laboratories

2017-06-09

A scaling methodology is described in the present paper for extreme-scale wind turbines (rated at 10 MW or more) that allow their sub-scale turbines to capture their key blade dynamics and aeroelastic deflections. For extreme-scale turbines, such deflections and dynamics can be substantial and are primarily driven by centrifugal, thrust and gravity forces as well as the net torque. Each of these are in turn a function of various wind conditions, including turbulence levels that cause shear, veer, and gust loads. The 13.2 MW rated SNL100-03 rotor design, having a blade length of 100-meters, is herein scaled to the CART3 wind turbine at NREL using 25% geometric scaling and blade mass and wind speed scaled by gravo-aeroelastic constraints. In order to mimic the ultralight structure on the advanced concept extreme-scale design the scaling results indicate that the gravo-aeroelastically scaled blades for the CART3 are be three times lighter and 25% longer than the current CART3 blades. A benefit of this scaling approach is that the scaled wind speeds needed for testing are reduced (in this case by a factor of two), allowing testing under extreme gust conditions to be much more easily achieved. Most importantly, this scaling approach can investigate extreme-scale concepts including dynamic behaviors and aeroelastic deflections (including flutter) at an extremely small fraction of the full-scale cost.

Technology-derived storage solutions for stabilizing insulin in extreme weather conditions I: the ViViCap-1 device.

Science.gov (United States)

Pfützner, Andreas; Pesach, Gidi; Nagar, Ron

2017-06-01

Injectable life-saving drugs should not be exposed to temperatures 30°C/86°F. Frequently, weather conditions exceed these temperature thresholds in many countries. Insulin is to be kept at 4-8°C/~ 39-47°F until use and once opened, is supposed to be stable for up to 31 days at room temperature (exception: 42 days for insulin levemir). Extremely hot or cold external temperature can lead to insulin degradation in a very short time with loss of its glucose-lowering efficacy. Combined chemical and engineering solutions for heat protection are employed in ViViCap-1 for disposable insulin pens. The device works based on vacuum insulation and heat consumption by phase-change material. Laboratory studies with exposure of ViViCap-1 to hot outside conditions were performed to evaluate the device performance. ViViCap-1 keeps insulin at an internal temperature phase-change process and 'recharges' the device for further use. ViViCap-1 performed within its specifications. The small and convenient device maintains the efficacy and safety of using insulin even when carried under hot weather conditions.

Effect of multiple-feedstock strategy on the economic and environmental performance of thermochemical ethanol production under extreme weather conditions

International Nuclear Information System (INIS)

Kou, Nannan; Zhao, Fu

2011-01-01

Current US transportation sector mainly relies on liquid hydrocarbons derived from petroleum and about 60% of the petroleum consumed is from areas where supply may be disturbed by regional instability. This has led to serious concerns on energy security and global warming. To address these issues, numerous alternative energy carriers have been proposed. Among them, second generation biofuel is one of the most promising technologies. Gasification-based thermochemical conversion will bring flexibility to both feedstock and production sides of a plant, thus presents an attractive technical route to address both the energy security and global warming concerns. In this paper, thermochemical ethanol production using multiple-feedstock (corn stover, municipal solid waste, and wood chips) is simulated using Aspen Plus and compared with the single-feedstock scenario, in terms of economic performances, life cycle greenhouse gas (GHG) emissions and survivability under extreme weather conditions. For a hypothetical facility in southwest Indiana it is found that multiple-feedstock strategy improves the net present value by 18% compared to single-feedstock strategy. This margin is increased to 57% when effects of extreme weather conditions on feedstock supply are considered. Moreover, multiple-feedstock fuel plant has no potential risk of bankruptcy during the payback period, while single-feedstock fuel plant has a 75% chance of bankruptcy. Although the multiple-feedstock strategy has 26% more GHG emission per liter of ethanol produced than the single-feedstock strategy, the trend is reversed if feedstock supply disruption is taken into account. Thus the idea of multiple-feedstock strategy is proposed to the future thermo chemical biofuel plants.

Carving out humanitarian space

Directory of Open Access Journals (Sweden)

Jean-François Durieux

2008-01-01

Full Text Available Agencies working inside Myanmar to assist forcibly displacedpeople work within an extremely constricted operationalenvironment. Despite occasional glimmers of hope, carvingout sufficient humanitarian space to meet urgent needsremains an uphill struggle.

Space in Space: Designing for Privacy in the Workplace

Science.gov (United States)

Akin, Jonie

2015-01-01

Privacy is cultural, socially embedded in the spatial, temporal, and material aspects of the lived experience. Definitions of privacy are as varied among scholars as they are among those who fight for their personal rights in the home and the workplace. Privacy in the workplace has become a topic of interest in recent years, as evident in discussions on Big Data as well as the shrinking office spaces in which people work. An article in The New York Times published in February of this year noted that "many companies are looking to cut costs, and one way to do that is by trimming personal space". Increasingly, organizations ranging from tech start-ups to large corporations are downsizing square footage and opting for open-office floorplans hoping to trim the budget and spark creative, productive communication among their employees. The question of how much is too much to trim when it comes to privacy, is one that is being actively addressed by the National Aeronautics and Space Administration (NASA) as they explore habitat designs for future space missions. NASA recognizes privacy as a design-related stressor impacting human health and performance. Given the challenges of sustaining life in an isolated, confined, and extreme environment such as Mars, NASA deems it necessary to determine the acceptable minimal amount for habitable volume for activities requiring at least some level of privacy in order to support optimal crew performance. Ethnographic research was conducted in 2013 to explore perceptions of privacy and privacy needs among astronauts living and working in space as part of a long-distance, long-duration mission. The allocation of space, or habitable volume, becomes an increasingly complex issue in outer space due to the costs associated with maintaining an artificial, confined environment bounded by limitations of mass while located in an extreme environment. Privacy in space, or space in space, provides a unique case study of the complex notions of

Development and performance test of a system available for generating multiple extreme conditions for neutron scattering experiments

International Nuclear Information System (INIS)

Kawano, Shinji; Fukui, Susumu; Moriai, Atsushi; Ohtomo, Akitoshi; Ichimura, Shigeki; Onodera, Akifumi; Amita, F.; Katano, Susumu

1998-01-01

We have developed unique system available for controlling sample environment during the neutron scattering experiments. The system can simultaneously generate triple extreme conditions of low temperature, high magnetic field and high pressure. The system consists of: (i) a liquid-helium cryostat variable for sample temperature from 1.7 K to 200 K, (ii) a superconducting magnet providing a vertical field up to ±5 T with an antisymmetric split-coil geometry for polarized-beam experiments, and (iii) a non-magnetic piston-cylinder high-pressure cell designed with the aim of generating hydrostatic pressure up to 2.5 GPa. In the presentation, we will report the outline of the system and some results of performance tests at KURRI and JRR-3M of JAERI. (author)

Can crawl space temperature and moisture conditions be calculated with a whole-building hygrothermal simulation tool?

DEFF Research Database (Denmark)

Vanhoutteghem, Lies; Morelli, Martin; Sørensen, Lars Schiøtt

2017-01-01

of measurements was compared with simulations of temperature and moisture condition in the floor structure and crawl space. The measurements showed that the extra 50 mm insulation placed below the beams reduced moisture content in the beams below 20 weight% all year. A reasonable agreement between......The hygrothermal behaviour of an outdoor ventilated crawl space with two different designs of the floor structure was investigated. The first design had 250 mm insulation and visible wooden beams towards the crawl space. The second design had 300 mm insulation and no visible wooden beams. One year...... the measurements and simulations was found; however, the evaporation from the soil was a dominant parameter affecting the hygrothermal response in the crawl space and floor structure....

Temporal and spatial scaling impacts on extreme precipitation

Science.gov (United States)

Eggert, B.; Berg, P.; Haerter, J. O.; Jacob, D.; Moseley, C.

2015-01-01

Both in the current climate and in the light of climate change, understanding of the causes and risk of precipitation extremes is essential for protection of human life and adequate design of infrastructure. Precipitation extreme events depend qualitatively on the temporal and spatial scales at which they are measured, in part due to the distinct types of rain formation processes that dominate extremes at different scales. To capture these differences, we first filter large datasets of high-resolution radar measurements over Germany (5 min temporally and 1 km spatially) using synoptic cloud observations, to distinguish convective and stratiform rain events. In a second step, for each precipitation type, the observed data are aggregated over a sequence of time intervals and spatial areas. The resulting matrix allows a detailed investigation of the resolutions at which convective or stratiform events are expected to contribute most to the extremes. We analyze where the statistics of the two types differ and discuss at which resolutions transitions occur between dominance of either of the two precipitation types. We characterize the scales at which the convective or stratiform events will dominate the statistics. For both types, we further develop a mapping between pairs of spatially and temporally aggregated statistics. The resulting curve is relevant when deciding on data resolutions where statistical information in space and time is balanced. Our study may hence also serve as a practical guide for modelers, and for planning the space-time layout of measurement campaigns. We also describe a mapping between different pairs of resolutions, possibly relevant when working with mismatched model and observational resolutions, such as in statistical bias correction.

Meteorological Drivers of Extreme Air Pollution Events

Science.gov (United States)

Horton, D. E.; Schnell, J.; Callahan, C. W.; Suo, Y.

2017-12-01

The accumulation of pollutants in the near-surface atmosphere has been shown to have deleterious consequences for public health, agricultural productivity, and economic vitality. Natural and anthropogenic emissions of ozone and particulate matter can accumulate to hazardous concentrations when atmospheric conditions are favorable, and can reach extreme levels when such conditions persist. Favorable atmospheric conditions for pollutant accumulation include optimal temperatures for photochemical reaction rates, circulation patterns conducive to pollutant advection, and a lack of ventilation, dispersion, and scavenging in the local environment. Given our changing climate system and the dual ingredients of poor air quality - pollutants and the atmospheric conditions favorable to their accumulation - it is important to characterize recent changes in favorable meteorological conditions, and quantify their potential contribution to recent extreme air pollution events. To facilitate our characterization, this study employs the recently updated Schnell et al (2015) 1°×1° gridded observed surface ozone and particulate matter datasets for the period of 1998 to 2015, in conjunction with reanalysis and climate model simulation data. We identify extreme air pollution episodes in the observational record and assess the meteorological factors of primary support at local and synoptic scales. We then assess (i) the contribution of observed meteorological trends (if extant) to the magnitude of the event, (ii) the return interval of the meteorological event in the observational record, simulated historical climate, and simulated pre-industrial climate, as well as (iii) the probability of the observed meteorological trend in historical and pre-industrial climates.

Space structures, power, and power conditioning; Proceedings of the Meeting, Los Angeles, CA, Jan. 11-13, 1988

International Nuclear Information System (INIS)

Askew, R.F.

1988-01-01

Various papers on space structures, power, and power conditioning are presented. Among the topics discussed are: heterogeneous gas core reaction for space nuclear power, pulsed gas core reactor for burst power, fundamental considerations of gas core reactor systems, oscillating thermionic conversion for high-density space power, thermoelectromagnetic pumps for space nuclear power systems, lightweight electrochemical converter for space power applications, ballistic acceleration by superheated hydrogen, laser-induced current switching in gaseous discharge, electron-beam-controlled semiconductor switches, laser-controlled semiconductor closing and opening switch. Also addressed are: semiconductor-metal eutectic composites for high-power switching, optical probes for the characterization of surface breakdown, 40 kV/20 kA pseudospark switch for laser applications, insulation direction for high-power space systems, state space simulation of spacecraft power systems, structural vibration of space power station systems, minimum-time control of large space structures, novel fusion reaction for space power and propulsion, repetition rate system evaluations, cryogenic silicon photoconductive switches for high-power lasers, multilevel diamondlike carbon capacitor structure, surface breakdown of prestressed insulators, C-Mo and C-Zr alloys for space power systems, magnetic insulation for the space environment

Detailed Analysis of Solar Data Related to Historical Extreme Geomagnetic Storms: 1868 – 2010

DEFF Research Database (Denmark)

Lefèvre, Laure; Vennerstrøm, Susanne; Dumbović, Mateja

2016-01-01

An analysis of historical Sun–Earth connection events in the context of the most extreme space weather events of the last ∼ 150 years is presented. To identify the key factors leading to these extreme events, a sample of the most important geomagnetic storms was selected based mainly on the well-...

Studies of nuclei under the extreme conditions of density, temperature, isospin asymmetry and the phase diagram of hadronic matter

Energy Technology Data Exchange (ETDEWEB)

Mekjian, Aram [Rutgers Univ., Piscataway, NJ (United States). Dept. of Physics and Astronomy

2016-10-18

The main emphasis of the entire project is on issues having to do with medium energy and ultra-relativistic energy and heavy ion collisions. A major goal of both theory and experiment is to study properties of hot dense nuclear matter under various extreme conditions and to map out the phase diagram in density or chemical potential and temperature. My studies in medium energy nuclear collisions focused on the liquid-gas phase transition and cluster yields from such transitions. Here I developed both the statistical model of nuclear multi-fragmentation and also a mean field theory.

Optimal bounds and extremal trajectories for time averages in dynamical systems

Science.gov (United States)

Tobasco, Ian; Goluskin, David; Doering, Charles

2017-11-01

For systems governed by differential equations it is natural to seek extremal solution trajectories, maximizing or minimizing the long-time average of a given quantity of interest. A priori bounds on optima can be proved by constructing auxiliary functions satisfying certain point-wise inequalities, the verification of which does not require solving the underlying equations. We prove that for any bounded autonomous ODE, the problems of finding extremal trajectories on the one hand and optimal auxiliary functions on the other are strongly dual in the sense of convex duality. As a result, auxiliary functions provide arbitrarily sharp bounds on optimal time averages. Furthermore, nearly optimal auxiliary functions provide volumes in phase space where maximal and nearly maximal trajectories must lie. For polynomial systems, such functions can be constructed by semidefinite programming. We illustrate these ideas using the Lorenz system, producing explicit volumes in phase space where extremal trajectories are guaranteed to reside. Supported by NSF Award DMS-1515161, Van Loo Postdoctoral Fellowships, and the John Simon Guggenheim Foundation.

Extreme quantile estimation for dependent data with applications to finance

OpenAIRE

Drees, Holger

2002-01-01

The asymptotic normality of a class of estimators for extreme quantiles is established under mild structural conditions on the observed stationary \\beta-mixing time series. Consistent estimators of the asymptotic variance are introduced, which render possible the construction of asymptotic confidence intervals for the extreme quantiles. Moreover, it is shown that many well-known time series models satisfy our conditions. Then the theory is applied to a time series of returns of a stock in...

Liquid Water Restricts Habitability in Extreme Deserts.

Science.gov (United States)

Cockell, Charles S; Brown, Sarah; Landenmark, Hanna; Samuels, Toby; Siddall, Rebecca; Wadsworth, Jennifer

2017-04-01

Liquid water is a requirement for biochemistry, yet under some circumstances it is deleterious to life. Here, we show that liquid water reduces the upper temperature survival limit for two extremophilic photosynthetic microorganisms (Gloeocapsa and Chroococcidiopsis spp.) by greater than 40°C under hydrated conditions compared to desiccated conditions. Under hydrated conditions, thermal stress causes protein inactivation as shown by the fluorescein diacetate assay. The presence of water was also found to enhance the deleterious effects of freeze-thaw in Chroococcidiopsis sp. In the presence of water, short-wavelength UV radiation more effectively kills Gloeocapsa sp. colonies, which we hypothesize is caused by factors including the greater penetration of UV radiation into hydrated colonies compared to desiccated colonies. The data predict that deserts where maximum thermal stress or irradiation occurs in conjunction with the presence of liquid water may be less habitable to some organisms than more extreme arid deserts where organisms can dehydrate prior to being exposed to these extremes, thus minimizing thermal and radiation damage. Life in extreme deserts is poised between the deleterious effects of the presence and the lack of liquid water. Key Words: Deserts-Extremophiles-Stress-High temperatures-UV radiation-Desiccation. Astrobiology 17, 309-318.

Some common random fixed point theorems for contractive type conditions in cone random metric spaces

Directory of Open Access Journals (Sweden)

Saluja Gurucharan S.

2016-08-01

Full Text Available In this paper, we establish some common random fixed point theorems for contractive type conditions in the setting of cone random metric spaces. Our results unify, extend and generalize many known results from the current existing literature.

Wiggling throat of extremal black holes

International Nuclear Information System (INIS)

Compère, G.; Hajian, K.; Seraj, A.; Sheikh-Jabbari, M.M.

2015-01-01

We construct the classical phase space of geometries in the near-horizon region of vacuum extremal black holes as announced in [arXiv:1503.07861]. Motivated by the uniqueness theorems for such solutions and for perturbations around them, we build a family of metrics depending upon a single periodic function defined on the torus spanned by the U(1) isometry directions. We show that this set of metrics is equipped with a consistent symplectic structure and hence defines a phase space. The phase space forms a representation of an infinite dimensional algebra of so-called symplectic symmetries. The symmetry algebra is an extension of the Virasoro algebra whose central extension is the black hole entropy. We motivate the choice of diffeomorphisms leading to the phase space and explicitly derive the symplectic structure, the algebra of symplectic symmetries and the corresponding conserved charges. We also discuss a formulation of these charges with a Liouville type stress-tensor on the torus defined by the U(1) isometries and outline possible future directions.

Motivating and Facilitating Advancements in Space Weather Real-Time Data Availability: Factors, Data, and Access Methods

Science.gov (United States)

Pankratz, C. K.; Baker, D. N.; Jaynes, A. N.; Elkington, S. R.; Baltzer, T.; Sanchez, F.

2017-12-01

Society's growing reliance on complex and highly interconnected technological systems makes us increasingly vulnerable to the effects of space weather events - maybe more than for any other natural hazard. An extreme solar storm today could conceivably impact hundreds of the more than 1400 operating Earth satellites. Such an extreme storm could cause collapse of the electrical grid on continental scales. The effects on navigation, communication, and remote sensing of our home planet could be devastating to our social functioning. Thus, it is imperative that the scientific community address the question of just how severe events might become. At least as importantly, it is crucial that policy makers and public safety officials be informed by the facts on what might happen during extreme conditions. This requires essentially real-time alerts, warnings, and also forecasts of severe space weather events, which in turn demands measurements, models, and associated data products to be available via the most effective data discovery and access methods possible. Similarly, advancement in the fundamental scientific understanding of space weather processes is also vital, requiring that researchers have convenient and effective access to a wide variety of data sets and models from multiple sources. The space weather research community, as with many scientific communities, must access data from dispersed and often uncoordinated data repositories to acquire the data necessary for the analysis and modeling efforts that advance our understanding of solar influences and space physics on the Earth's environment. The Laboratory for Atmospheric and Space Physics (LASP), as a leading institution in both producing data products and advancing the state of scientific understanding of space weather processes, is well positioned to address many of these issues. In this presentation, we will outline the motivating factors for effective space weather data access, summarize the various data

Observing extreme-mass-ratio inspirals with eLISA/NGO

OpenAIRE

Gair, Jonathan R; Porter, Edward K

2012-01-01

The extreme-mass-ratio inspirals (EMRIs) of stellar mass compact objects into massive black holes in the centres of galaxies are an important source of low-frequency gravitational waves for space-based detectors. We discuss the prospects for detecting these sources with the evolved Laser Interferometer Space Antenna (eLISA), recently proposed as an ESA mission candidate under the name NGO. We show that NGO could observe a few tens of EMRIs over its two year mission lifetime at redshifts z < 0...

The Influence of Pre-conditioning on the Space Charge Formation in LDPE and XLPE

DEFF Research Database (Denmark)

Henriksen, Mogens; Holbøll, Joachim T.; Fleming, R.J.

1996-01-01

Planar LDPE and XLPE samples were conditioned by holding in short circuit for 48 hrs. at 40oC under rotary pump pressure, and space charge accumulation in these samples under DC fields of 20 kV/mm was then compared with the corresponding accumulation in unconditioned samples.The test results were...

Advanced cryocooler electronics for space

Energy Technology Data Exchange (ETDEWEB)

Harvey, D.; Danial, A.; Godden, J.; Jackson, M.; McCuskey, J.; Valenzuela, P. [Northrop Grumman Space Technology, Redondo Beach, CA (United States); Davis, T. [Air Force Research Lab., Albuquerque, NM (United States)

2004-08-01

Space pulse-tube cryocoolers require electronics to control the cooling temperature and self-induced vibration. Other functions include engineering diagnostics, telemetry and safety protection of the unit against extreme environments and operational anomalies. The electronics must survive the harsh conditions of launch and orbit, and in some cases severe radiation environments for periods exceeding 10 years. A number of our current generation high reliability radiation hardened electronics units have been launched and others are in various stages of assembly or integration on a number of space flight programs. This paper describes the design features and performance of our next generation flight electronics designed for the STSS payloads. The electronics provides temperature control with better than +/-50 mK short-term stability. Self-induced vibration is controlled to low levels on all harmonics up to the 16th. A unique active power filter limits peak-to-peak reflected ripple current on the primary power bus to less than 3% of the average DC current. The 3 kg unit is capable of delivering 180 W continuous to NGST's high-efficiency cryocooler (HEC). (author)

Generalized conditions for the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space

International Nuclear Information System (INIS)

Manoukian, E.B.

1986-01-01

Generalized conditions (rules) are set up for the existence of the distributional zero-mass limit of renormalized Feynman amplitudes in Minkowski space. These rules are generalizations of rules that have been set up earlier by us and hence are applicable to a larger class of graphs. The study is very general as the vanishing masses are led to vanish at different rates. All subtractions of renormalization are carried out directly in momentum space, about the origin, with the degree of divergence of a subtraction coinciding with the dimensionality of the corresponding subdiagram

TYPHOID FEVER WITH FATAL OUTCOME IN PEOPLE WITH SEVERE TROPHOLOGICAL FAILURE IN EXTREME CONDITIONS

Directory of Open Access Journals (Sweden)

Yu. I. Lyashenko

2017-01-01

Full Text Available For purpose of clinical and morphological characterization of typhoid fever with fatal outcome was perform analysis of medical documentation as well as postmortem studies of internal tissues in 36men aged 21 to 34 years with severe body weight loss and in the conditions of combat stress in period from 1983 to 1985. The results of the study find a number of clinical and pathomorphological features of typhoid fever in patients with body weight deficiency that were in extreme conditions. Focal changes of the central nervous system were detected. The defeat of the respiratory system was characterized from the first days of the disease by bronchitis, and in the subsequent development of pneumonia, plevritis and empyema of the pleura. Majority of patients had symptoms of cardiovascular and renal failure. In died in the first week of the disease and in 2/3 parts – in a later period were combined with the symptoms of infectious-toxic encephalopathy and severe acute respiratory failure. All died had postmortem dystrophic changes of cardiomyocytes, and in patients had fatal outcome in 2–5 weeks – also focal or diffuse myocarditis. In a third of the patients who died, the disease was complicated by intestinal perforations. In a number of cases, peritonitis was a consequence of necrosis of mesenteric lymph nodes. In all patients with a fatal outcome, hemorrhagic (thrombohemorrhagic syndrome was diagnosed. A significant proportion of patients posthumously detected signs of sepsis and other complications, many of which could be the cause of death.

Approaches in the determination of plant nutrient uptake and distribution in space flight conditions

Science.gov (United States)

Heyenga, A. G.; Forsman, A.; Stodieck, L. S.; Hoehn, A.; Kliss, M.

2000-01-01

The effective growth and development of vascular plants rely on the adequate availability of water and nutrients. Inefficiency in either the initial absorption, transportation, or distribution of these elements are factors which impinge on plant structure and metabolic integrity. The potential effect of space flight and microgravity conditions on the efficiency of these processes is unclear. Limitations in the available quantity of space-grown plant material and the sensitivity of routine analytical techniques have made an evaluation of these processes impractical. However, the recent introduction of new plant cultivating methodologies supporting the application of radionuclide elements and subsequent autoradiography techniques provides a highly sensitive investigative approach amenable to space flight studies. Experiments involving the use of gel based 'nutrient packs' and the radionuclides calcium-45 and iron-59 were conducted on the Shuttle mission STS-94. Uptake rates of the radionuclides between ground and flight plant material appeared comparable.

Intramuscular vascular malformations of an extremity: findings on MR imaging and pathologic correlation

International Nuclear Information System (INIS)

Kim, E.Y.; Ahn, J.M.; Yoon, H.K.; Do, Y.S.; Kim, S.H.; Choo, S.W.; Choo, I.W.; Suh, Y.L.; Kim, S.M.; Kang, H.S.

1999-01-01

Objective. To analyze the findings of intramuscular vascular malformations of an extremity on MR imaging and to correlate these findings with histopathologic examination.Design and patients. The findings on MR imaging and the medical records of 14 patients with an intramuscular vascular malformation of the extremity were retrospectively studied. All patients underwent surgical excision. Diagnoses were based on the results of pathologic examination. Findings on MR imaging were noted and correlated with the histopathologic findings.Results. Intramuscular vascular malformations of an extremity showed multi-septate, honeycomb, or mixed appearance on MR imaging. Multi-septate areas correlated with dilated and communicating vascular spaces with flattened endothelium. Honeycomb areas corresponded to vascular spaces with inconspicuous small lumina and thickened vascular walls. Areas of increased signal intensity on T2-weighted images were found in all intramuscular vascular malformations. Infiltrative margins were more commonly seen in intramuscular lymphaticovenous malformations. Adherence to neurovascular structures and orientation of the lesion along the long axis of the affected muscle were more commonly seen in intramuscular venous malformations.Conclusions. Intramuscular vascular malformations showed either a multi-septate, honeycomb, or mixed appearance, reflecting the size of the vascular spaces and the thickness of the smooth muscles of the vessel walls. Prediction of the subtype of an intramuscular vascular malformation of an extremity on MR imaging seems to be difficult, although there are associated findings that may be helpful in the differential diagnosis of each subtype. (orig.)

Investigations on the transverse phase space at a photo injector for minimized emittance

Energy Technology Data Exchange (ETDEWEB)

Miltchev, V.

2006-08-15

Radio frequency photoinjectors are electron sources able to generate beams of extremely high brightness, which are applicable to linac driven Free Electron Lasers (FEL). Because of the high phase space density, the dynamics of the electron beam is dominated by space charge interactions between the particles. This thesis studies the transverse phase space of space charge dominated electron beams produced by the Photo Injector Test Facility in Zeuthen (PITZ). The operation conditions for minimizing the transverse emittance are studied experimentally, theoretically and in simulations. The influence of the longitudinal profile of the driving UV laser pulse on the transverse emittance is investigated. Emphasis is placed on the experimental study of the emittance as a function of different machine parameters like the laser beam spot size, the amplitude of the focusing magnetic field, the rf phase and the electron bunch charge. First investigations on the thermal emittance for Cs{sub 2}Te photocathodes under rf operating conditions are presented. Measurements of the thermal emittance scaling with the photocathode laser spot size are analyzed. The significance of the applied rf field in the emittance formation process is discussed. (orig.)

Investigations on the transverse phase space at a photo injector for minimized emittance

International Nuclear Information System (INIS)

Miltchev, V.

2006-08-01

Radio frequency photoinjectors are electron sources able to generate beams of extremely high brightness, which are applicable to linac driven Free Electron Lasers (FEL). Because of the high phase space density, the dynamics of the electron beam is dominated by space charge interactions between the particles. This thesis studies the transverse phase space of space charge dominated electron beams produced by the Photo Injector Test Facility in Zeuthen (PITZ). The operation conditions for minimizing the transverse emittance are studied experimentally, theoretically and in simulations. The influence of the longitudinal profile of the driving UV laser pulse on the transverse emittance is investigated. Emphasis is placed on the experimental study of the emittance as a function of different machine parameters like the laser beam spot size, the amplitude of the focusing magnetic field, the rf phase and the electron bunch charge. First investigations on the thermal emittance for Cs 2 Te photocathodes under rf operating conditions are presented. Measurements of the thermal emittance scaling with the photocathode laser spot size are analyzed. The significance of the applied rf field in the emittance formation process is discussed. (orig.)

Scale dependency of regional climate modeling of current and future climate extremes in Germany

Science.gov (United States)

Tölle, Merja H.; Schefczyk, Lukas; Gutjahr, Oliver

2017-11-01

A warmer climate is projected for mid-Europe, with less precipitation in summer, but with intensified extremes of precipitation and near-surface temperature. However, the extent and magnitude of such changes are associated with creditable uncertainty because of the limitations of model resolution and parameterizations. Here, we present the results of convection-permitting regional climate model simulations for Germany integrated with the COSMO-CLM using a horizontal grid spacing of 1.3 km, and additional 4.5- and 7-km simulations with convection parameterized. Of particular interest is how the temperature and precipitation fields and their extremes depend on the horizontal resolution for current and future climate conditions. The spatial variability of precipitation increases with resolution because of more realistic orography and physical parameterizations, but values are overestimated in summer and over mountain ridges in all simulations compared to observations. The spatial variability of temperature is improved at a resolution of 1.3 km, but the results are cold-biased, especially in summer. The increase in resolution from 7/4.5 km to 1.3 km is accompanied by less future warming in summer by 1 ∘C. Modeled future precipitation extremes will be more severe, and temperature extremes will not exclusively increase with higher resolution. Although the differences between the resolutions considered (7/4.5 km and 1.3 km) are small, we find that the differences in the changes in extremes are large. High-resolution simulations require further studies, with effective parameterizations and tunings for different topographic regions. Impact models and assessment studies may benefit from such high-resolution model results, but should account for the impact of model resolution on model processes and climate change.

A combination of extreme environmental conditions favor the prevalence of Endospore-forming Firmicutes

Directory of Open Access Journals (Sweden)

Sevasti Filippidou

2016-11-01

Full Text Available Environmental conditions unsuitable for microbial growth are the rule rather than the exception in most habitats. In response to this, microorganisms have developed various strategies to withstand environmental conditions that limit active growth. Endospore-forming Firmicutes (EFF deploy a myriad of survival strategies in order to resist adverse conditions. Like many bacterial groups, they can form biofilms and detect nutrient scarcity through chemotaxis. Moreover, within this paraphyletic group of Firmicutes, ecophysiological optima are diverse. Nonetheless, a response to adversity that delimits this group is the formation of wet-heat resistant spores. These strategies are energetically demanding and therefore might affect the biological success of EFF. Therefore, we hypothesize that abundance and diversity of EFF should be maximized in those environments in which the benefits of these survival strategies offsets the energetic cost. In order to address this hypothesis, geothermal and mineral springs and drillings were selected because in these environments of steep physicochemical gradients, diversified survival strategies may become a successful strategy. We collected 71 samples from geothermal and mineral environments characterized by none (null, single or multiple limiting environmental factors (temperature, pH, UV radiation and specific mineral composition. To measure success, we quantified EFF gene copy numbers (GCN; spo0A gene in relation to total bacterial GCN (16S rRNA gene, as well as the contribution of EFF to community composition. The quantification showed that relative GCN for EFF reached up to 20% at sites characterized by multiple limiting environmental factors, whereas it corresponded to less than 1% at sites with one or no limiting environmental factor. Pyrosequencing of the 16S rRNA gene supports a higher contribution of EFF at sites with multiple limiting factors. Community composition suggested a combination of phylotypes

Dynamics and cultural specifics of information needs under conditions of long-term space flight

Science.gov (United States)

Feichtinger, Elena; Shved, Dmitry; Gushin, Vadim

Life in conditions of space flight or chamber study with prolonged isolation is associated with lack of familiar stimuli (sensory deprivation), monotony, significant limitation of communication, and deficit of information and media content (Myasnikov V.I., Stepanova S.I. et al., 2000). Fulfillment of a simulation experiment or flight schedule implies necessity of performance of sophisticated tasks and decision making with limited means of external support. On the other hand, the “stream” of information from the Mission Control (MC) and PI’s (reminders about different procedures to be performed, requests of reports, etc.) is often inadequate to communication needs of crewmembers. According to the theory of “information stress” (Khananashvili M.M., 1984), a distress condition could be formed if: a) it’s necessary to process large amounts of information and make decisions under time pressure; b) there is a prolonged deficit of necessary (e.g. for decision making) information. Thus, we suppose that one of the important goals of psychological support of space or space simulation crews should be forming of favorable conditions of information environment. For that purpose, means of crew-MC information exchange (quantitative characteristics and, if possible, content of radiograms, text and video messages, etc.) should be studied, as well as peculiarities of the crewmembers’ needs in different information and media content, and their reactions to incoming information. In the space simulation experiment with 520-day isolation, communication of international crew with external parties had been studied. Dynamics of quantitative and content characteristics of the crew’s messages was related to the experiment’s stage, presence of “key” events in the schedule (periods of high autonomy, simulated “planetary landing”, etc.), as well as to events not related to the experiment (holidays, news, etc.). It was shown that characteristics of information exchange

Evidence of Molecular Adaptation to Extreme Environments and Applicability to Space Environments

Directory of Open Access Journals (Sweden)

Filipović, M. D.

2008-06-01

Full Text Available This is initial investigation of gene signatures responsible for adapting microscopic life to the extreme Earth environments. We present preliminary results on identification of the clusters of orthologous groups (COGs common to several hyperthermophiles and exclusion of those common to a mesophile (non-hyperthermophile: {it Escherichia coli (E. coli K12}, will yield a group of proteins possibly involved in adaptation to life under extreme temperatures. Comparative genome analyses represent a powerful tool in discovery of novel genes responsible for adaptation to specific extreme environments. Methanogens stand out as the only group of organisms that have species capable of growth at 0D C ({it Metarhizium frigidum (M.~frigidum} and {it Methanococcoides burtonii (M.~burtonii} and 110D C ({it Methanopyrus kandleri (M.~kandleri}. Although not all the components of heat adaptation can be attributed to novel genes, the {it chaperones} known as heat shock proteins stabilize the enzymes under elevated temperature. However, highly conserved {it chaperons} found in bacteria and eukaryots are not present in hyperthermophilic Archea, rather, they have a unique {it chaperone TF55}. Our aim was to use software which we specifically developed for extremophile genome comparative analyses in order to search for additional novel genes involved in hyperthermophile adaptation. The followinghyperthermophile genomes incorporated in this software were used forthese studies: {it Methanocaldococcus jannaschii (M.~jannaschii, M.~kandleri, Archaeoglobus fulgidus (A.~fulgidus} and threespecies of {it Pyrococcus}. Common genes were annotated and groupedaccording to their roles in cellular processes where such informationwas available and proteins not previously implicated in theheat-adaptation of hyperthermophiles were identified. Additionalexperimental data are needed in order to learn more about theseproteins. To address non-gene based components of thermaladaptation

Evidence of molecular adaptation to extreme environments and applicability to space environments

Directory of Open Access Journals (Sweden)

Filipović M.

2008-01-01

Full Text Available This is initial investigation of gene signatures responsible for adapting microscopic life to the extreme Earth environments. We present preliminary results on identification of the clusters of orthologous groups (COGs common to several hyperthermophiles and exclusion of those common to a mesophile (non-hyperthermophile: Escherichia coli (E. coli K12, will yield a group of proteins possibly involved in adaptation to life under extreme temperatures. Comparative genome analyses represent a powerful tool in discovery of novel genes responsible for adaptation to specific extreme environments. Methanogens stand out as the only group of organisms that have species capable of growth at 0ºC (Metarhizium frigidum (M. frigidum and Methanococcoides burtonii (M. burtonii and 110ºC (Methanopyrus kandleri (M. kandleri. Although not all the components of heat adaptation can be attributed to novel genes, the chaperones known as heat shock proteins stabilize the enzymes under elevated temperature. However, highly conserved chaperons found in bacteria and eukaryots are not present in hyperthermophilic Archea, rather, they have a unique chaperone TF55. Our aim was to use software which we specifically developed for extremophile genome comparative analyses in order to search for additional novel genes involved in hyperthermophile adaptation. The following hyperthermophile genomes incorporated in this software were used for these studies: Methanocaldococcus jannaschii (M. jannaschii, M. kandleri, Archaeoglobus fulgidus (A. fulgidus and three species of Pyrococcus. Common genes were annotated and grouped according to their roles in cellular processes where such information was available and proteins not previously implicated in the heat-adaptation of hyperthermophiles were identified. Additional experimental data are needed in order to learn more about these proteins. To address non-gene based components of thermal adaptation, all sequenced extremophiles were

The quantum oscillator on complex projective space (Lobachewski space) in a constant magnetic field and the issue of generic boundary conditions

International Nuclear Information System (INIS)

Giri, Pulak Ranjan

2007-01-01

We perform a one-parameter family of self-adjoint extensions characterized by the parameter ω 0 . This allows us to get generic boundary conditions for the quantum oscillator on N-dimensional complex projective space (CP N ) and on its non-compact version, i.e., Lobachewski space (L N ) in the presence of a constant magnetic field. As a result, we get a family of energy spectra for the oscillator. In our formulation the already known result of this oscillator also belongs to the family. We have also obtained an energy spectrum which preserves all the symmetries (full-hidden symmetry and rotational symmetry) of the oscillator. The method of self-adjoint extensions has also been discussed for a conic oscillator in the presence of the constant magnetic field

Creating and Understanding Hybrid Interfaces of Multifunctional Composite Laminates for Extreme Environments

Data.gov (United States)

National Aeronautics and Space Administration — Due to increasing needs for lightweight and multifunctional structures and materials that can operate at and sustain the extreme environment such as high temperature...

Predictors of Behavior and Performance in Extreme Environments: The Antarctic Space Analogue Program

Science.gov (United States)

Palinkas, Lawrence A.; Gunderson, E K. Eric; Holland, A. W.; Miller, Christopher; Johnson, Jeffrey C.

2000-01-01

To determine which, if any, characteristics should be incorporated into a select-in approach to screening personnel for long-duration spaceflight, we examined the influence of crewmember social/ demographic characteristics, personality traits, interpersonal needs, and characteristics of station physical environments on performance measures in 657 American men who spent an austral winter in Antarctica between 1963 and 1974. During screening, subjects completed a Personal History Questionnaire which obtained information on social and demographic characteristics, the Deep Freeze Opinion Survey which assessed 5 different personality traits, and the Fundamental Interpersonal Relations Orientation-Behavior (FIRO-B) Scale which measured 6 dimensions of interpersonal needs. Station environment included measures of crew size and severity of physical environment. Performance was assessed on the basis of combined peer-supervisor evaluations of overall performance, peer nominations of fellow crewmembers who made ideal winter-over candidates, and self-reported depressive symptoms. Social/demographic characteristics, personality traits, interpersonal needs, and characteristics of station environments collectively accounted for 9-17% of the variance in performance measures. The following characteristics were significant independent predictors of more than one performance measure: military service, low levels of neuroticism, extraversion and conscientiousness, and a low desire for affection from others. These results represent an important first step in the development of select-in criteria for personnel on long-duration missions in space and other extreme environments. These criteria must take into consideration the characteristics of the environment and the limitations they place on meeting needs for interpersonal relations and task performance, as well as the characteristics of the individuals and groups who live and work in these environments.

ENTROPY PRODUCTION IN COLLISIONLESS SYSTEMS. II. ARBITRARY PHASE-SPACE OCCUPATION NUMBERS

International Nuclear Information System (INIS)

Barnes, Eric I.; Williams, Liliya L. R.

2012-01-01

We present an analysis of two thermodynamic techniques for determining equilibria of self-gravitating systems. One is the Lynden-Bell (LB) entropy maximization analysis that introduced violent relaxation. Since we do not use the Stirling approximation, which is invalid at small occupation numbers, our systems have finite mass, unlike LB's isothermal spheres. (Instead of Stirling, we utilize a very accurate smooth approximation for ln x!.) The second analysis extends entropy production extremization to self-gravitating systems, also without the use of the Stirling approximation. In addition to the LB statistical family characterized by the exclusion principle in phase space, and designed to treat collisionless systems, we also apply the two approaches to the Maxwell-Boltzmann (MB) families, which have no exclusion principle and hence represent collisional systems. We implicitly assume that all of the phase space is equally accessible. We derive entropy production expressions for both families and give the extremum conditions for entropy production. Surprisingly, our analysis indicates that extremizing entropy production rate results in systems that have maximum entropy, in both LB and MB statistics. In other words, both thermodynamic approaches lead to the same equilibrium structures.

Role of Winter Weather Conditions and Slipperiness on Tourists’ Accidents in Finland

Directory of Open Access Journals (Sweden)

Élise Lépy

2016-08-01

Full Text Available (1 Background: In Finland, slippery snowy or icy ground surface conditions can be quite hazardous to human health during wintertime. We focused on the impacts of the variability in weather conditions on tourists’ health via documented accidents during the winter season in the Sotkamo area. We attempted to estimate the slipping hazard in a specific context of space and time focusing on the weather and other possible parameters, responsible for fluctuations in the numbers of injuries/accidents; (2 Methods: We used statistical distributions with graphical illustrations to examine the distribution of visits to Kainuu Hospital by non-local patients and their characteristics/causes; graphs to illustrate the distribution of the different characteristics of weather conditions; questionnaires and interviews conducted among health care and safety personnel in Sotkamo and Kuusamo; (3 Results: There was a clear seasonal distribution in the numbers and types of extremity injuries of non-local patients. While the risk of slipping is emphasized, other factors leading to injuries are evaluated; and (4 Conclusions: The study highlighted the clear role of wintery weather conditions as a cause of extremity injuries even though other aspects must also be considered. Future scenarios, challenges and adaptive strategies are also discussed from the viewpoint of climate change.

Studies on penetration of antibiotic in bacterial cells in space conditions (7-IML-1)

Science.gov (United States)

Tixador, R.

1992-01-01

The Cytos 2 experiment was performed aboard Salyut 7 in order to test the antibiotic sensitivity of bacteria cultivated in vitro in space. An increase of the Minimal Inhibitory Concentration (MIC) in the inflight cultures (i.e., an increase of the antibiotic resistance) was observed. Complementary studies of the ultrastructure showed a thickening of the cell envelope. In order to confirm the results of the Cytos 2 experiment, we performed the ANTIBIO experiment during the D1 mission to try to differentiate, by means of the 1 g centrifuge in the Biorack, between the biological effects of cosmic rays and those caused by microgravity conditions. The originality of this experiment was in the fact that it was designed to test the antibiotic sensitivity of bacteria cultivated in vitro during the orbital phase of the flight. The results show an increase in resistance to Colistin in in-flight bacteria. The MIC is practically double in the in-flight cultures. A cell count of living bacteria in the cultures containing the different Colistin concentrations showed a significant difference between the cultures developed during space flight and the ground based cultures. The comparison between the 1 g and 0 g in-flight cultures show similar behavior for the two sets. Nevertheless, a small difference between the two sets of ground based control cultures was noted. The cultures developed on the ground centrifuge (1.4 g) present a slight decrease in comparison with the cultures developed in the static rack (1 g). In order to approach the mechanisms of the increase of antibiotic resistance on bacteria cultivated in vitro in space, we have proposed the study on penetration of antibiotics in bacterial cells in space conditions. This experiment was selected for the International Microgravity Laboratory 1 (IML-1) mission.

Space-efficient path-reporting approximate distance oracles

DEFF Research Database (Denmark)

Elkin, Michael; Neiman, Ofer; Wulff-Nilsen, Christian

2016-01-01

We consider approximate path-reporting distance oracles, distance labeling and labeled routing with extremely low space requirements, for general undirected graphs. For distance oracles, we show how to break the nlog⁡n space bound of Thorup and Zwick if approximate paths rather than distances need...

Extremal extensions for the sum of nonnegative selfadjoint relations

NARCIS (Netherlands)

Hassi, Seppo; Sandovici, Adrian; De Snoo, Henk; Winkler, Henrik

2007-01-01

The sum A + B of two nonnegative selfadjoint relations (multivalued operators) A and B is a nonnegative relation. The class of all extremal extensions of the sum A + B is characterized as products of relations via an auxiliary Hilbert space associated with A and B. The so-called form sum extension

Extreme climate, not extreme weather: the summer of 1816 in Geneva, Switzerland

Directory of Open Access Journals (Sweden)

R. Auchmann

2012-02-01

Full Text Available We analyze weather and climate during the "Year without Summer" 1816 using sub-daily data from Geneva, Switzerland, representing one of the climatically most severely affected regions. The record includes twice daily measurements and observations of air temperature, pressure, cloud cover, wind speed, and wind direction as well as daily measurements of precipitation. Comparing 1816 to a contemporary reference period (1799–1821 reveals that the coldness of the summer of 1816 was most prominent in the afternoon, with a shift of the entire distribution function of temperature anomalies by 3–4 °C. Early morning temperature anomalies show a smaller change for the mean, a significant decrease in the variability, and no changes in negative extremes. Analyzing cloudy and cloud-free conditions separately suggests that an increase in the number of cloudy days was to a significant extent responsible for these features. A daily weather type classification based on pressure, pressure tendency, and wind direction shows extremely anomalous frequencies in summer 1816, with only one day (compared to 20 in an average summer classified as high-pressure situation but a tripling of low-pressure situations. The afternoon temperature anomalies expected from only a change in weather types was much stronger negative in summer 1816 than in any other year. For precipitation, our analysis shows that the 80% increase in summer precipitation compared to the reference period can be explained by 80% increase in the frequency of precipitation, while no change could be found neither in the average intensity of precipitation nor in the frequency distribution of extreme precipitation. In all, the analysis shows that the regional circulation and local cloud cover played a dominant role. It also shows that the summer of 1816 was an example of extreme climate, not extreme weather.

Test fields cannot destroy extremal black holes

International Nuclear Information System (INIS)

Natário, José; Queimada, Leonel; Vicente, Rodrigo

2016-01-01

We prove that (possibly charged) test fields satisfying the null energy condition at the event horizon cannot overspin/overcharge extremal Kerr–Newman or Kerr–Newman–anti de Sitter black holes, that is, the weak cosmic censorship conjecture cannot be violated in the test field approximation. The argument relies on black hole thermodynamics (without assuming cosmic censorship), and does not depend on the precise nature of the fields. We also discuss generalizations of this result to other extremal black holes. (paper)

QUALITATIVE ANALYSIS OF EXTREMAL PROBLEMS IN ARBITRARY DOMAINS

Directory of Open Access Journals (Sweden)

Samokhin Mikhail Vasilevich

2012-10-01

The author considers the problems concerning where B is either a unit sphere in the (D space or one of the classes , p>1. He shows the possibility of the results concerning the characteristic of extreme functions, their uniqueness, the possilble presentation of the functions from the classes and with the use of the Cauchy-Stieltjes integrals in the component of the D\\ suppµ set and the boundary behavior of an extreme function from the (D class. One should note that the given mathematical system can be implemented for making decisions in the field of construction engineering and structural analysis, it can provide research assistants and engineers with the background necessary for developing sound solutions and rational proposals.

Three theorems on near horizon extremal vanishing horizon geometries

Directory of Open Access Journals (Sweden)

S. Sadeghian

2016-02-01

Full Text Available EVH black holes are Extremal black holes with Vanishing Horizon area, where vanishing of horizon area is a result of having a vanishing one-cycle on the horizon. We prove three theorems regarding near horizon geometry of EVH black hole solutions to generic Einstein gravity theories in diverse dimensions. These generic gravity theories are Einstein–Maxwell-dilaton-Λ theories, and gauged or ungauged supergravity theories with U(1 Maxwell fields. Our three theorems are: (1 The near horizon geometry of any EVH black hole has a three dimensional maximally symmetric subspace. (2 If the energy momentum tensor of the theory satisfies strong energy condition either this 3d part is an AdS3, or the solution is a direct product of a locally 3d flat space and a d−3 dimensional part. (3 These results extend to the near horizon geometry of near-EVH black holes, for which the AdS3 part is replaced with BTZ geometry.

Investigating Extreme Lifestyles through Mangrove Transcriptomics

Science.gov (United States)

Dassanayake, Maheshi

2009-01-01

Mangroves represent phylogenetically diverse taxa in tropical coastal terrestrial habitats. They are extremophiles, evolutionarily adapted to tolerate flooding, anoxia, high temperatures, wind, and high and extremely variable salt conditions in typically resource-poor environments. The genetic basis for these adaptations is, however, virtually…

Extreme summer temperatures in Iberia: health impacts and associated synoptic conditions

OpenAIRE

Garcia-Herrera , R.; Diaz , J.; Trigo , R. M.; Hernández , E.

2005-01-01

This paper examines the effect of extreme summer temperatures on daily mortality in two large cities of Iberia: Lisbon (Portugal) and Madrid (Spain). Daily mortality and meteorological variables are analysed using the same methodology based on Box-Jenkins models. Results reveal that in both cases there is a triggering effect on mortality when maximum daily temperature exceeds a given threshold (34°C in Lisbon and 36°C in Madrid). The impact of most intense heat events is very ...

Conformal Einstein spaces

International Nuclear Information System (INIS)

Kozameh, C.N.; Newman, E.T.; Tod, K.P.

1985-01-01

Conformal transformations in four-dimensional. In particular, a new set of two necessary and sufficient conditions for a space to be conformal to an Einstein space is presented. The first condition defines the class of spaces conformal to C spaces, whereas the last one (the vanishing of the Bach tensor) gives the particular subclass of C spaces which are conformally related to Einstein spaces. (author)

Potential changes in the extreme climate conditions at the regional scale: from observed data to modelling approaches and towards probabilistic climate change information

International Nuclear Information System (INIS)

Gachon, P.; Radojevic, M.; Harding, A.; Saad, C.; Nguyen, V.T.V.

2008-01-01

The changes in the characteristics of extreme climate conditions are one of the most critical challenges for all ecosystems, human being and infrastructure, in the context of the on-going global climate change. However, extremes information needed for impacts studies cannot be obtained directly from coarse scale global climate models (GCMs), due mainly to their difficulties to incorporate regional scale feedbacks and processes responsible in part for the occurrence, intensity and duration of extreme events. Downscaling approaches, namely statistical and dynamical downscaling techniques (i.e. SD and RCM), have emerged as useful tools to develop high resolution climate change information, in particular for extremes, as those are theoretically more capable to take into account regional/local forcings and their feedbacks from large scale influences as they are driven with GCM synoptic variables. Nevertheless, in spite of the potential added values from downscaling methods (statistical and dynamical), a rigorous assessment of these methods are needed as inherent difficulties to simulate extremes are still present. In this paper, different series of RCM and SD simulations using three different GCMs are presented and evaluated with respect to observed values over the current period and over a river basin in southern Quebec, with future ensemble runs, i.e. centered over 2050s (i.e. 2041-2070 period using the SRES A2 emission scenario). Results suggest that the downscaling performance over the baseline period significantly varies between the two downscaling techniques and over various seasons with more regular reliable simulated values with SD technique for temperature than for RCM runs, while both approaches produced quite similar temperature changes in the future from median values with more divergence for extremes. For precipitation, less accurate information is obtained compared to observed data, and with more differences among models with higher uncertainties in the

Extremely High Suction Performance Inducers for Space Propulsion, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The proposed innovation provides a way to design low flow coefficient inducers that have higher cavitation breakdown margin, larger blade angles, thicker more...

Extreme conditioning programs and injury risk in a US Army Brigade Combat Team.

Science.gov (United States)

Grier, Tyson; Canham-Chervak, Michelle; McNulty, Vancil; Jones, Bruce H

2013-01-01

Brigades and battalions throughout the US Army are currently implementing a variety of exercise and conditioning programs with greater focus on preparation for mission-specific tasks. An Army physical therapy clinic working with a light infantry brigade developed the Advanced Tactical Athlete Conditioning (ATAC) program. The ATAC program is a unique physical training program consisting of high-intensity aquatic exercises, tactical agility circuits, combat core conditioning, and interval speed training. Along with ATAC, battalions have also incorporated components of fitness programs such as the Ranger Athlete Warrior program and CrossFit (Crossfit, Inc, Santa Monica, CA) an extreme conditioning program (ECP). To determine if these new programs (ATAC, ECP) had an effect on injury rates and physical fitness. Surveys were administered to collect personal characteristics, tobacco use, personal physical fitness training, Army physical fitness test results, and self-reported injuries. Medical record injury data were obtained 6 months before and 6 months after the implementation of the new program. Predictors of injury risk were assessed using multivariate logistic regression. Odds ratios (OR) and 95% confidence intervals (CI) were reported. Injury incidence among Soldiers increased 12% for overall injuries and 16% for overuse injuries after the implementation of the ATAC/ECPs. However, injury incidence among Soldiers not participating in ATAC/ECPs also increased 14% for overall injuries and 10% for overuse injuries. Risk factors associated with higher injury risk for Soldiers participating in ATAC/ECPs included: greater mileage run per week during unit physical training (OR (>16 miles per week÷≤7 miles per week)=2.24, 95% CI, 1.33-3.80); higher body mass index (BMI) (OR (BMI 25-29.9÷BMI<25)=1.77, 95% CI, 1.29-2.44), (OR (BMI =30÷BMI<25)=2.72, 95% CI, 1.67-4.43); cigarette use (OR (smoker÷nonsmoker)=1.80, 95% CI, 1.34-2.42); poor performance on the 2-mile run during

A Generalized Framework for Non-Stationary Extreme Value Analysis

Science.gov (United States)

Ragno, E.; Cheng, L.; Sadegh, M.; AghaKouchak, A.

2017-12-01

Empirical trends in climate variables including precipitation, temperature, snow-water equivalent at regional to continental scales are evidence of changes in climate over time. The evolving climate conditions and human activity-related factors such as urbanization and population growth can exert further changes in weather and climate extremes. As a result, the scientific community faces an increasing demand for updated appraisal of the time-varying climate extremes. The purpose of this study is to offer a robust and flexible statistical tool for non-stationary extreme value analysis which can better characterize the severity and likelihood of extreme climatic variables. This is critical to ensure a more resilient environment in a changing climate. Following the positive feedback on the first version of Non-Stationary Extreme Value Analysis (NEVA) Toolbox by Cheng at al. 2014, we present an improved version, i.e. NEVA2.0. The upgraded version herein builds upon a newly-developed hybrid evolution Markov Chain Monte Carlo (MCMC) approach for numerical parameters estimation and uncertainty assessment. This addition leads to a more robust uncertainty estimates of return levels, return periods, and risks of climatic extremes under both stationary and non-stationary assumptions. Moreover, NEVA2.0 is flexible in incorporating any user-specified covariate other than the default time-covariate (e.g., CO2 emissions, large scale climatic oscillation patterns). The new feature will allow users to examine non-stationarity of extremes induced by physical conditions that underlie the extreme events (e.g. antecedent soil moisture deficit, large-scale climatic teleconnections, urbanization). In addition, the new version offers an option to generate stationary and/or non-stationary rainfall Intensity - Duration - Frequency (IDF) curves that are widely used for risk assessment and infrastructure design. Finally, a Graphical User Interface (GUI) of the package is provided, making NEVA

Simulation Evaluation of Controller-Managed Spacing Tools under Realistic Operational Conditions

Science.gov (United States)

Callantine, Todd J.; Hunt, Sarah M.; Prevot, Thomas

2014-01-01

Controller-Managed Spacing (CMS) tools have been developed to aid air traffic controllers in managing high volumes of arriving aircraft according to a schedule while enabling them to fly efficient descent profiles. The CMS tools are undergoing refinement in preparation for field demonstration as part of NASA's Air Traffic Management (ATM) Technology Demonstration-1 (ATD-1). System-level ATD-1 simulations have been conducted to quantify expected efficiency and capacity gains under realistic operational conditions. This paper presents simulation results with a focus on CMS-tool human factors. The results suggest experienced controllers new to the tools find them acceptable and can use them effectively in ATD-1 operations.

TransFormers for Ensuring Long-Term Operations in Lunar Extreme Environments

Science.gov (United States)

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

2016-01-01

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

Extremely High Suction Performance Inducers for Space Propulsion, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Advanced pump inducer design technology that uses high inlet diffusion blades, operates at a very low flow coefficient, and employs a cavitation control and...

A comparison study of the two-bladed partial pitch turbine during normal operation and an extreme gust conditions

International Nuclear Information System (INIS)

Kim, T; Petersen, M M; Larsen, T J

2014-01-01

This paper shows the load comparisons between the numerical simulation and the full-scale load measurement data. First part of this paper includes the comparisons of statistic load in terms of maximum, mean, and minimum values for the selected normal operation cases. The blade root bending moments and tower top bending moments are compared. Second part of this paper introduces the dynamic response comparisons during an extreme wind gust condition where the wind speed changed approximately 10 m/s during three seconds. The rotor speed and blade root flapwise and edgewise bending moment are compared. The nonlinear aeroelastic simulation code HAWC2 is used for the simulations. A very fine agreement between the simulated and the full-scale measured loads is seen for the both comparisons

HERCULES Specialized Course on Synchrotron radiation and neutrons for extreme conditions studies - HSC12 - slides of the presentations

International Nuclear Information System (INIS)

Daniel, I.; Itie, J.P.; Meersman, F.; Jacobs, J.; Hantsetters, K. de; Syassen, K.; Krisch, M.; Mezouar, M.; Mac Millan, P.F.; Salmon, P.; Klotz, S.; Pascarelli, S.; Hansen, T.C.

2011-01-01

The purpose of this Hercules Specialized Course (HSC12) is to give the participants an introduction to high pressure research at large experimental facilities such as the synchrotron and the neutron reactor. The basic principles of synchrotron radiation and neutrons techniques at extreme conditions of pressure have been illustrated. Cross-disciplinary examples in a representative range of scientific areas, covering fundamental physics, earth and planetary science, chemistry and material science have been dealt with. Most presentations are dedicated to X-ray diffraction, X-ray absorption and neutron scattering of materials (solids, liquids or glasses) at high pressure. Several presentations deal with the experimental set-up and especially the preparation of the diamond anvil. This document is made up of the slides of the presentations. (A.C.)

Automatic residue removal for high-NA extreme illumination

Science.gov (United States)

Moon, James; Nam, Byong-Sub; Jeong, Joo-Hong; Kong, Dong-Ho; Nam, Byung-Ho; Yim, Dong Gyu

2007-10-01

An epidemic for smaller node has been that, as the device architecture shrinks, lithography process requires high Numerical Aperture (NA), and extreme illumination system. This, in turn, creates many lithography problems such as low lithography process margin (Depth of Focus, Exposure Latitude), unstable Critical Dimension (CD) uniformity and restricted guideline for device design rule and so on. Especially for high NA, extreme illumination such as immersion illumination systems, above all the related problems, restricted design rule due to forbidden pitch is critical and crucial issue. This forbidden pitch is composed of numerous optical effects but majority of these forbidden pitch compose of photo resist residue and these residue must be removed to relieve some room for already tight design rule. In this study, we propose automated algorithm to remove photo resist residue due to high NA and extreme illumination condition. This algorithm automatically self assembles assist patterns based on the original design layout, therefore insuring the safety and simplicity of the generated assist pattern to the original design and removes any resist residue created by extreme illumination condition. Also we tested our automated algorithm on full chip FLASH memory device and showed the residue removal effect by using commercial verification tools as well as on actual test wafer.

Schwarzian导数,几何条件和Qκ空间%Schwarzian derivative, geometric conditions and Qκ spaces

Institute of Scientific and Technical Information of China (English)

周继振

2012-01-01

设Ψ:D→Ω是一个单叶函数,利用Schwarzian导数,本文获得了logΨ'属于Qκ空间的一个充要条件.此外,本文运用了一个几何条件来刻画Qκ空间.%For a univalent function Ψ : D → Ω, we study the membership of logψ' to the space QK in terms of the Schwarzian derivative. We also apply a geometric condition to characterize the space QK.

Atmospheric conditions associated with extreme fire activity in the Western Mediterranean region.

Science.gov (United States)

Amraoui, Malik; Pereira, Mário G; DaCamara, Carlos C; Calado, Teresa J

2015-08-15

Active fire information provided by TERRA and AQUA instruments on-board sun-synchronous polar MODIS platform is used to describe fire activity in the Western Mediterranean and to identify and characterize the synoptic patterns of several meteorological fields associated with the occurrence of extreme fire activity episodes (EEs). The spatial distribution of the fire pixels during the period of 2003-2012 leads to the identification of two most affected sub-regions, namely the Northern and Western parts of the Iberian Peninsula (NWIP) and Northern Africa (NAFR). The temporal distribution of the fire pixels in these two sub-regions is characterized by: (i) high and non-concurrent inter- and intra-annual variability with maximum values during the summer of 2003 and 2005 in NWIP and 2007 and 2012 in NAFR; and, (ii) high intra-annual variability dominated by a prominent annual cycle with a main peak centred in August in both sub-regions and a less pronounced secondary peak in March only evident in NWIP region. The 34 EEs identified were grouped according to the location, period of occurrence and spatial configuration of the associated synoptic patterns into 3 clusters (NWIP-summer, NWIP-winter and NAFR-summer). Results from the composite analysis reveal similar fire weather conditions (statistically significant positive anomalies of air temperature and negative anomalies of air relative humidity) but associated with different circulation patterns at lower and mid-levels of the atmosphere associated with the occurrence of EEs in each cluster of the Western Mediterranean region. Copyright © 2015 Elsevier B.V. All rights reserved.

Integrability and symmetric spaces. II- The coset spaces

International Nuclear Information System (INIS)

Ferreira, L.A.

1987-01-01

It shown that a sufficient condition for a model describing the motion of a particle on a coset space to possess a fundamental Poisson bracket relation, and consequently charges involution, is that it must be a symmetric space. The conditions a hamiltonian, or any function of the canonical variables, has to satisfy in order to commute with these charges are studied. It is shown that, for the case of non compact symmetric space, these conditions lead to an algebraic structure which plays an important role in the construction of conserved quantities. (author) [pt

Analyses of crystal field and exchange interaction of Dy3Ga5O12 under extreme conditions

International Nuclear Information System (INIS)

Wang Wei; Qi Xin; Yue Yuan

2011-01-01

This paper theoretically investigates the effects of crystal field and exchange interaction field on magnetic properties in dysprosium gallium garnet under extreme conditions (low temperatures and high magnetic fields) based on quantum theory. Here, five sets of crystal field parameters are discussed and compared. It demonstrates that, only considering the crystal field effect, the experiments can not be successfully explained. Thus, referring to the molecular field theory, an effective exchange field associated with the Dy—Dy exchange interaction is further taken into account. Under special consideration of crystal field and the exchange interaction field, it obtains an excellent agreement between the theoretical results and experiments, and further confirms that the exchange interaction field between rare-earth ions has great importance to magnetic properties in paramagnetic rare-earth gallium garnets. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Opacity calculations for extreme physical systems: code RACHEL

Science.gov (United States)

Drska, Ladislav; Sinor, Milan

1996-08-01

Computer simulations of physical systems under extreme conditions (high density, temperature, etc.) require the availability of extensive sets of atomic data. This paper presents basic information on a self-consistent approach to calculations of radiative opacity, one of the key characteristics of such systems. After a short explanation of general concepts of the atomic physics of extreme systems, the structure of the opacity code RACHEL is discussed and some of its applications are presented.

Angiomyolipoma of the perinephric space: case report

International Nuclear Information System (INIS)

Shin, Ho Seob; Yoon, Seong Kuk; Lee, Jin Hwa; Kim, Chan Sung; Oh, Jong Young; Shin, Tae Beom; Lee, Ki Nam; Nam, Kyung Jin; Kim, Dae Cheol

2002-01-01

Angiomyolipomas commonly originate from renal parenchyma but extremely rarely from perinephric space. We report a case of angiomyolipoma of the perinephric space confirmed by radical nephrectomy. A 13-year-old boy presented with left flank pain and abdominal distension, first experienced five months earlier. Ultrasonography and CT indicated that in the space surrounding the left kidney, a huge fat-containing mass with linear strands was present

Angiomyolipoma of the perinephric space: case report

Energy Technology Data Exchange (ETDEWEB)

Shin, Ho Seob; Yoon, Seong Kuk; Lee, Jin Hwa; Kim, Chan sung; Oh, Jong Young; Shin, Tae Beom; Lee, Ki Nam; Nam, Kyung Jin; Kim, Dae Cheol [Dong a University College of Medicine, Busan (Korea, Republic of)

2002-12-01

Angiomyolipomas commonly originate from neral parenchyma but extremely rarely from perinephric space. We report a case of angiomyolipoma of the perinephric space confirmed by radical nephrectomy. A 13-year-old boy resented with left flank pain and abdominal distension, first experienced five months earlier. Ultrasonography and CT indicated that in the space surrounding the left kidney, a huge fat-containing mass with linear strands was present.

Angiomyolipoma of the perinephric space: case report

International Nuclear Information System (INIS)

Shin, Ho Seob; Yoon, Seong Kuk; Lee, Jin Hwa; Kim, Chan sung; Oh, Jong Young; Shin, Tae Beom; Lee, Ki Nam; Nam, Kyung Jin; Kim, Dae Cheol

2002-01-01

Angiomyolipomas commonly originate from neral parenchyma but extremely rarely from perinephric space. We report a case of angiomyolipoma of the perinephric space confirmed by radical nephrectomy. A 13-year-old boy resented with left flank pain and abdominal distension, first experienced five months earlier. Ultrasonography and CT indicated that in the space surrounding the left kidney, a huge fat-containing mass with linear strands was present

Expert consensus on facilitators and barriers to return-to-work following surgery for non-traumatic upper extremity conditions: a Delphi study.

Science.gov (United States)

Peters, S E; Johnston, V; Ross, M; Coppieters, M W

2017-02-01

This Delphi study aimed to reach consensus on important facilitators and barriers for return-to-work following surgery for non-traumatic upper extremity conditions. In Round 1, experts ( n = 42) listed 134 factors, which were appraised in Rounds 2 and 3. Consensus (⩾85% agreement) was achieved for 13 facilitators (high motivation to return-to-work; high self-efficacy for return-to-work and recovery; availability of modified/alternative duties; flexible return-to-work arrangements; positive coping skills; limited heavy work exertion; supportive return-to-work policies; supportive supervisor/management; no catastrophic thinking; no fear avoidance to return-to-work; no fear avoidance to pain/activity; return to meaningful work duties; high job satisfaction) and six barriers (mood disorder diagnosis; pain/symptoms at more than one musculoskeletal site; heavy upper extremity exertions at work; lack of flexible return-to-work arrangements; lack of support from supervisor/management; high level of pain catastrophizing). Future prognostic studies are required to validate these biopsychosocial factors to further improve return-to-work outcomes. V.

Validation of nonlinear FEA models of a thin-walled elbow under extreme loading conditions for Sodium-cooled Fast Reactors

International Nuclear Information System (INIS)

Watakabe, Tomoyoshi; Wakai, Takashi; Jin, Chuanrong; Usui, Yoshiya; Sakai, Shinkichi; Ooshika, Junji; Tsukimori, Kazuyuki

2015-01-01

For the purpose of confirming failure modes and safety margin, some studies on the ultimate strength of thin-walled piping components for Sodium-cooled Fast Reactors (SFRs) under extreme loading conditions such as large earthquakes have been reported these several years. Nonlinear finite element analysis has been applied in these studies to simulate buckling and yielding with large deformation, whose accuracy is dependent on the element type, the mesh size, the elasto-plastic model and so on. It is important to check the validation of a finite element model for nonlinear analysis especially under extreme loading conditions. This paper presents static and dynamic analyses of a thin-walled elbow with large deformation under large seismic loading, and discusses the validation of the FEA models comparing with experimental results. The finite element analysis models in this study are generated by shell elements for a stainless steel pipe elbow of diameter-to-thickness ratio 59:1 similar to the main pipe of SFRs, which is used for shaking table tests. At first, a static analysis is carried out for an in-plane monotonic bending test, in order to confirm that the shell element is appropriate to the large deformation analysis and the material parameters are proper for the strain level in the experiments. And then, a dynamic in-plane bending test with the maximum acceleration of 11.7G is simulated by the nonlinear FEA with stiffness-proportional damping. The influence of mesh sizes on results is investigated, to determine proper mesh sizes and reduce the computational cost. Finally, comparing the results of the FEM analyses with those of experiments, it is concluded that the appropriately generated FEA models are effective and give accurate results for nonlinear analyses of the thin-walled elbow under large seismic loading. (author)

Art and Architectural Space

DEFF Research Database (Denmark)

Unterrainer, Walter

2014-01-01

and its content. The urban and spatial question goes far beyond museums and other buildings for art: how in democratic societies should public spaces be supported by art and how can public art support ´cityness´ and meaning versus spaces of consumerism. Famous but egocentric buildings with the main......art and architectural space museums and other exhibition spaces or how artists learn to love architects Over the last two decades, innumerable new museums, art galleries and other exhibition spaces have been built and opened all over the globe. The most extreme growth happened in China, where...... historically considered even the mother of all arts) - but more relevant: what are appropriate architectural spaces for presenting, exhibiting, contemplating, reflecting, meditating, discussing, enjoying, dissenting, debating creations of art. Simplified, this is a question about the relation between package...

Predicting temperature and moisture distributions in conditioned spaces using the zonal approach

Energy Technology Data Exchange (ETDEWEB)

Mendonca, K.C. [Parana Pontifical Catholic Univ., Curitiba (Brazil); Wurtz, E.; Inard, C. [La Rochelle Univ., La Rochelle, Cedex (France). LEPTAB

2005-07-01

Moisture interacts with building elements in a number of different ways that impact upon building performance, causing deterioration of building materials, as well as contributing to poor indoor air quality. In humid climates, moisture represents one of the major loads in conditioned spaces. It is therefore important to understand and model moisture transport accurately. This paper discussed an intermediate zonal approach to building a library of data in order to predict whole hygrothermal behavior in conditioned rooms. The zonal library included 2 models in order to consider building envelope moisture buffering effects as well as taking into account the dynamic aspect of jet airflow in the zonal method. The zonal library was then applied to a case study to show the impact of external humidity on the whole hygrothermal performance of a room equipped with a vertical fan-coil unit. The proposed theory was structured into 3 groups representing 3 building domains: indoor air; envelope; and heating, ventilation and air conditioning (HVAC) systems. The indoor air sub-model related to indoor air space, where airflow speed was considered to be low. The envelope sub-model related to the radiation exchanges between the envelope and its environment as well as to the heat and mass transfers through the envelope material. The HVAC system sub-model referred to the whole system including equipment, control and specific airflow from the equipment. All the models were coupled into SPARK, where the resulting set of non-linear equations were solved simultaneously. A case study of a large office conditioned by a vertical fan-coil unit with a rectangular air supply diffuser was presented. Details of the building's external and internal environment were provided, as well as convective heat and mass transfer coefficients and temperature distributions versus time. Results of the study indicated that understanding building material moisture buffering effects is as important as

On the necessary conditions of the regular minimum of the scale factor of the co-moving space

International Nuclear Information System (INIS)

Agakov, V.G.

1980-01-01

In the framework of homogeneous cosmologic model studied is the behaviour of the comoving space element volume filled with barotropous medium, deprived of energy fluxes. Presented are the necessary conditions at which a regular final minimum of the scale factor of the co-mowing space may take place. It is found that to carry out the above minimum at values of cosmological constant Λ <= 0 the presence of two from three anisotropy factors is necessary. Anisotropy of space deformation should be one of these factors. In case of Λ <= 0 the regular minimum is also possible if all three factors of anisotropy are equal to zero. However if none of the factors of Fsub(i), Asub(ik) anisotropy is equal to zero, the presence of deformation space anisotropy is necessary for final regular minimum appearance

Extreme Heat: A Prevention Guide to Promote Your Personal Health and Safety

Science.gov (United States)

... Extreme Heat Older Adults (Aged 65+) Infants and Children Chronic Medical Conditions Low Income Athletes Outdoor Workers Pets Hot Weather Tips Warning Signs and Symptoms FAQs Social Media How to Stay Cool Missouri Cooling Centers Extreme ...

Space research on organs and tissues

Science.gov (United States)

Tischler, Marc E.; Morey-Holton, Emily

1993-01-01

Studies in space on various physiological systems have and will continue to provide valuable information on how they adapt to reduced gravitational conditions, and how living in a 1 g (gravity) environment has guided their development. Muscle and bone are the most notable tissues that respond to unweighting caused by lack of gravity. The function of specific muscles and bones relates directly to mechanical loading, so that removal of 'normal forces' in space, or in bedridden patients, causes dramatic loss of tissue mass. The cardiovascular system is also markedly affected by reduced gravity. Adaptation includes decreased blood flow to the lower extremities, thus decreasing the heart output requirement. Return to 1 g is associated with a period of reconditioning due to the deconditioning that occurs in space. Changes in the cardiovascular system are also related to responses of the kidney and certain endocrine (hormone-producing) organs. Changes in respiratory function may also occur, suggesting an effect on the lungs, though this adaptation is poorly understood. The neurovestibular system, including the brain and organs of the inner ear, must adapt to the disorientation caused by lack of gravity. Preliminary findings have been reported for liver. Additionally, endocrine organs responsible for release of hormones such as insulin, growth hormone, glucocorticoids, and thyroid hormone may respond to spaceflight.

The Logistical Challenges of the SpaceLiner Concept

OpenAIRE

van Foreest, Arnold; Sippel, Martin

2008-01-01

The SpaceLiner concept developed at DLR combines extremely fast transport (90 minutes from Europe to Australia) with the experience of Space flight. As such it is different from the spaceflight which focuses exclusively on space tourism but it combines space tourism with for example business travel. The SpaceLiner is designed to carry 50 passengers in suborbital flight. The conceptual technical design presents some challenges which have already been partially investigated at DLR [1]. However,...

The role of the International Space University in building capacity in emerging space nations.

Science.gov (United States)

Richards, Robert

The International Space University provides graduate-level training to the future leaders of the emerging global space community at its Central Campus in Strasbourg, France, and at locations around the world. In its two-month Summer Session and one-year Masters program, ISU offers its students a unique Core Curriculum covering all disciplines related to space programs and enterprises - space science, space engineering, systems engineering, space policy and law, business and management, and space and society. Both programs also involve an intense student research Team Project providing international graduate students and young space professionals the opportunity to solve complex problems by working together in an intercultural environment. Since its founding in 1987, ISU has graduated more than 2500 students from 96 countries. Together with hundreds of ISU faculty and lecturers from around the world, ISU alumni comprise an extremely effective network of space professionals and leaders that actively facilitates individual career growth, professional activities and international space cooperation.

Upper-extremity phocomelia reexamined: a longitudinal dysplasia.

Science.gov (United States)

Goldfarb, Charles A; Manske, Paul R; Busa, Riccardo; Mills, Janith; Carter, Peter; Ezaki, Marybeth

2005-12-01

In contrast to longitudinal deficiencies, phocomelia is considered a transverse, intercalated segmental dysplasia. Most patients demonstrate severe, but not otherwise classifiable, upper-extremity deformities, which usually cannot be placed into one of three previously described phocomelia groups. Additionally, these phocomelic extremities do not demonstrate true segmental deficits; the limb is also abnormal proximal and distal to the segmental defect. The purpose of this investigation was to present evidence that upper-extremity abnormalities in patients previously diagnosed as having phocomelia in fact represent a proximal continuum of radial or ulnar longitudinal dysplasia. The charts and radiographs of forty-one patients (sixty extremities) diagnosed as having upper-extremity phocomelia were reviewed retrospectively. On the basis of the findings on the radiographs, the disorders were categorized into three groups: (1) proximal radial longitudinal dysplasia, which was characterized by an absent proximal part of the humerus, a nearly normal distal part of the humerus, a completely absent radius, and a radial-sided hand dysplasia; (2) proximal ulnar longitudinal dysplasia, characterized by a short one-bone upper extremity that bifurcated distally and by severe hand abnormalities compatible with ulnar dysplasia; and (3) severe combined dysplasia, with type A characterized by an absence of the forearm segment (i.e., the radius and ulna) and type B characterized by absence of the arm and forearm (i.e., the hand attached to the thorax). Twenty-nine limbs in sixteen patients could be classified as having proximal radial longitudinal dysplasia. Systemic medical conditions such as thrombocytopenia-absent radius syndrome were common in those patients, but additional musculoskeletal conditions were rare. Twenty limbs in seventeen patients could be classified as having proximal ulnar longitudinal dysplasia. Associated musculoskeletal abnormalities, such as proximal femoral

High-resolution stochastic generation of extreme rainfall intensity for urban drainage modelling applications

Science.gov (United States)

Peleg, Nadav; Blumensaat, Frank; Molnar, Peter; Fatichi, Simone; Burlando, Paolo

2016-04-01

Urban drainage response is highly dependent on the spatial and temporal structure of rainfall. Therefore, measuring and simulating rainfall at a high spatial and temporal resolution is a fundamental step to fully assess urban drainage system reliability and related uncertainties. This is even more relevant when considering extreme rainfall events. However, the current space-time rainfall models have limitations in capturing extreme rainfall intensity statistics for short durations. Here, we use the STREAP (Space-Time Realizations of Areal Precipitation) model, which is a novel stochastic rainfall generator for simulating high-resolution rainfall fields that preserve the spatio-temporal structure of rainfall and its statistical characteristics. The model enables a generation of rain fields at 102 m and minute scales in a fast and computer-efficient way matching the requirements for hydrological analysis of urban drainage systems. The STREAP model was applied successfully in the past to generate high-resolution extreme rainfall intensities over a small domain. A sub-catchment in the city of Luzern (Switzerland) was chosen as a case study to: (i) evaluate the ability of STREAP to disaggregate extreme rainfall intensities for urban drainage applications; (ii) assessing the role of stochastic climate variability of rainfall in flow response and (iii) evaluate the degree of non-linearity between extreme rainfall intensity and system response (i.e. flow) for a small urban catchment. The channel flow at the catchment outlet is simulated by means of a calibrated hydrodynamic sewer model.

Mechanical properties of lunar materials under anhydrous, hard vacuum conditions: applications of lunar glass structural components

International Nuclear Information System (INIS)

Blacic, J.D.

1984-01-01

Lunar materials and derivatives such as glass may possess very high tensile strengths compared to equivalent materials on earth because of the absence of hydrolytic weakening processes on the moon and in the hard vacuum of free space. Hydrolyzation of Si-O bonds at crack tips or dislocations reduces the strength of silicates by about an order of magnitude in earth environments. However, lunar materials are extremely anhydrous and hydrolytic weakening will be suppressed in free space. Thus, the geomechanical properties of the moon and engineering properties of lunar silicate materials in space environments will be very different than equivalent materials under earth conditions where the action of water cannot be conveniently avoided. Possible substitution of lunar glass for structural metals in a variety of space engineering applications enhances the economic utilization of the moon. 26 references, 3 figures, 2 tables

Modular Hamiltonians for deformed half-spaces and the averaged null energy condition

Science.gov (United States)

Faulkner, Thomas; Leigh, Robert G.; Parrikar, Onkar; Wang, Huajia

2016-09-01

We study modular Hamiltonians corresponding to the vacuum state for deformed half-spaces in relativistic quantum field theories on {{R}}^{1,d-1} . We show that in addition to the usual boost generator, there is a contribution to the modular Hamiltonian at first order in the shape deformation, proportional to the integral of the null components of the stress tensor along the Rindler horizon. We use this fact along with monotonicity of relative entropy to prove the averaged null energy condition in Minkowski space-time. This subsequently gives a new proof of the Hofman-Maldacena bounds on the parameters appearing in CFT three-point functions. Our main technical advance involves adapting newly developed perturbative methods for calculating entanglement entropy to the problem at hand. These methods were recently used to prove certain results on the shape dependence of entanglement in CFTs and here we generalize these results to excited states and real time dynamics. We also discuss the AdS/CFT counterpart of this result, making connection with the recently proposed gravitational dual for modular Hamiltonians in holographic theories.

Investigating NARCCAP Precipitation Extremes via Bivariate Extreme Value Theory (Invited)

Science.gov (United States)

Weller, G. B.; Cooley, D. S.; Sain, S. R.; Bukovsky, M. S.; Mearns, L. O.

2013-12-01

We introduce methodology from statistical extreme value theory to examine the ability of reanalysis-drive regional climate models to simulate past daily precipitation extremes. Going beyond a comparison of summary statistics such as 20-year return values, we study whether the most extreme precipitation events produced by climate model simulations exhibit correspondence to the most extreme events seen in observational records. The extent of this correspondence is formulated via the statistical concept of tail dependence. We examine several case studies of extreme precipitation events simulated by the six models of the North American Regional Climate Change Assessment Program (NARCCAP) driven by NCEP reanalysis. It is found that the NARCCAP models generally reproduce daily winter precipitation extremes along the Pacific coast quite well; in contrast, simulation of past daily summer precipitation extremes in a central US region is poor. Some differences in the strength of extremal correspondence are seen in the central region between models which employ spectral nudging and those which do not. We demonstrate how these techniques may be used to draw a link between extreme precipitation events and large-scale atmospheric drivers, as well as to downscale extreme precipitation simulated by a future run of a regional climate model. Specifically, we examine potential future changes in the nature of extreme precipitation along the Pacific coast produced by the pineapple express (PE) phenomenon. A link between extreme precipitation events and a "PE Index" derived from North Pacific sea-surface pressure fields is found. This link is used to study PE-influenced extreme precipitation produced by a future-scenario climate model run.

Space Shuttle Main Propulsion System Anomaly Detection: A Case Study

Data.gov (United States)

National Aeronautics and Space Administration — The space shuttle main engine (SSME) is part of the Main Propnlsion System (MPS) which is an extremely complex system containing several sub-systems and components,...

Extremely Short Optical Pulses and Ads/CFT Compliance

Directory of Open Access Journals (Sweden)

Konobeeva N.N.

2015-01-01

Full Text Available Dynamics of few cycle optical pulses in non-Fermi liquid was considered. Energy spectrum of non-Fermi liquid was taken from the AdS/CFT compliance. Conditions of quasiparticle excitation existence were defined. Non-Fermi liquid parameters impact on the shape of few cycle pulses were estimated. It was shown that extremely short optical pulse propagation in the non-Fermi liquid is a stable pattern. The value of chemical potential has a significant impact on extremely short pulse shape. An increase in initial pulse amplitude does not result in pulse-shape distortions under its propagation in considered medium that is why the non-Fermi liquid can be used in applications inherent in extremely short pulse processing.

Chemistry in interstellar space. [environment characteristics influencing reaction dynamics

Science.gov (United States)

Donn, B.

1973-01-01

The particular characteristics of chemistry in interstellar space are determined by the unique environmental conditions involved. Interstellar matter is present at extremely low densities. Large deviations from thermodynamic equilibrium are, therefore, to be expected. A relatively intense ultraviolet radiation is present in many regions. The temperatures are in the range from 5 to 200 K. Data concerning the inhibiting effect of small activation energies in interstellar clouds are presented in a table. A summary of measured activation energies or barrier heights for exothermic exchange reactions is also provided. Problems of molecule formation are discussed, taking into account gas phase reactions and surface catalyzed processes.

Survival of pathogenic bacteria under nutrient starvation conditions. [aboard orbiting space stations

Science.gov (United States)

Boyle, Michael; Ford, Tim; Mitchell, Ralph; Maki, James

1990-01-01

The survival of opportunistic pathogenic microorganisms in water, under nutrient-limiting conditions, has been investigated in order to ascertain whether human pathogens can survive within a water-distribution system of the kind proposed for the NASA Space Station. Cultures of a strain of pseudomonas aeruginosa and two strains of staphylococcus aureus were incubated at 10, 25, or 37 C, and samples at 1 day, 1 week, 1 month, and six weeks. While neither of the staphylococcus strains tested were detected after 1 week of starvation, the pseudomonas strain can survive in deionized water at all three temperatures.

Dressing method and quadratic bundles related to symmetric spaces. Vanishing boundary conditions

Science.gov (United States)

Valchev, T. I.

2016-02-01

We consider quadratic bundles related to Hermitian symmetric spaces of the type SU(m + n)/S(U(m) × U(n)). The simplest representative of the corresponding integrable hierarchy is given by a multi-component Kaup-Newell derivative nonlinear Schrödinger equation which serves as a motivational example for our general considerations. We extensively discuss how one can apply Zakharov-Shabat's dressing procedure to derive reflectionless potentials obeying zero boundary conditions. Those could be used for one to construct fast decaying solutions to any nonlinear equation belonging to the same hierarchy. One can distinguish between generic soliton type solutions and rational solutions.

Assessment of extreme hydrological conditions in the Bothnian Bay, Baltic Sea, and the impact of the nuclear power plant "Hanhikivi-1" on the local thermal regime

Science.gov (United States)

Dvornikov, Anton Y.; Martyanov, Stanislav D.; Ryabchenko, Vladimir A.; Eremina, Tatjana R.; Isaev, Alexey V.; Sein, Dmitry V.

2017-04-01

The results of the study aimed to assess the influence of future nuclear power plant Hanhikivi-1 upon the local thermal conditions in the Bothnian Bay in the Baltic Sea are presented. A number of experiments with different numerical models were also carried out in order to estimate the extreme hydro-meteorological conditions in the area of the construction. The numerical experiments were fulfilled both with analytically specified external forcing and with real external forcing for 2 years: a cold year (2010) and a warm year (2014). The study has shown that the extreme values of sea level and water temperature and the characteristics of wind waves and sea ice in the vicinity of the future nuclear power plant can be significant and sometimes catastrophic. Permanent release of heat into the marine environment from an operating nuclear power plant will lead to a strong increase in temperature and the disappearance of ice cover within a 2 km vicinity of the station. These effects should be taken into account when assessing local climate changes in the future.

Space weather in the EU’s FP7 Space Theme

Directory of Open Access Journals (Sweden)

Chiarini Paola

2013-11-01

Full Text Available Technological infrastructures in space and on ground provide services on which modern society and economies rely. Space weather related research is funded under the 7th Framework Programme for Research and Innovation (FP7 of the European Union in response to the need of protecting such critical infrastructures from the damage which could be caused by extreme space weather events. The calls for proposals published under the topic “Security of space assets from space weather events” of the FP7 Space Theme aimed to improve forecasts and predictions of disruptive space weather events as well as identify best practices to limit the impacts on space- and ground-based infrastructures and their data provision. Space weather related work was also funded under the topic “Exploitation of space science and exploration data”, which aims to add value to space missions and Earth-based observations by contributing to the effective scientific exploitation of collected data. Since 2007 a total of 20 collaborative projects have been funded, covering a variety of physical phenomena associated with space weather, from ionospheric disturbances and scintillation, to geomagnetically induced currents at Earth’s surface, to coronal mass ejections and solar energetic particles. This article provides an overview of the funded projects, touching upon some results and referring to specific websites for a more exhaustive description of the projects’ outcomes.

Extremely stable piezo mechanisms for the New Gravitational Wave Observatory

NARCIS (Netherlands)

Pijnenburg, J.A.C.M.; Rijnveld, N.; Hogenhuis, H.

2012-01-01

Detection and observation of gravitational waves requires extreme stability in the frequency range 3e-5 Hz to 1 Hz. NGO/LISA will attain this by creating a giant interferometer in space, based on free floating proof masses in three spacecrafts. To operate NGO/LISA, the following piezo mechanisms are

Baryon number nonconservation in extreme conditions

International Nuclear Information System (INIS)

Matveev, V.A.; Rubakov, V.A.; Tavkhelidze, A.N.; Shaposhnikov, M.E.

1988-01-01

In gauge theories with the left-right asymmetric fermionic content (e.g. in standard electroweak theory) fermion number F is not conserved due to the anomaly. It is shown that anomalous processes, while being exponentially suppressed, under normal conditions, are in fact rapid. The mechanism of fermionic number nonconservation connected with a level crossing phenomenon in external gauge fields is described. The theory and experimental consequences of monopole catalysis of a proton decay is reviewed. It is shown that cold dense fermionic matter is stable only up to some limiting density. It is demonstrated that there is no exponential suppression of the rate F nonconservation at high temperatures. The cosmological implications of this fact are discussed. The strong anomalous fermionic number violation in decays of superheavy fermions technibaryons is considered

Super Dwarf Wheat for Growth in Confined Spaces

Science.gov (United States)

Bugbee, Bruce

2011-01-01

USU-Perigee is a dwarf red spring wheat that is a hybrid of a high-yield early tall wheat (USU-Apogee) and a low-yield, extremely short wheat that has poor agronomic characteristics. USU-Perigee was selected for its extremely short height (.0.3 m) and high yield . characteristics that make it suitable for growth in confined spaces in controlled environments. Other desirable characteristics include rapid development and resistance to a leaf-tip necrosis, associated with calcium deficiency, that occurs in other wheat cultivars under rapid-growth conditions (particularly, continuous light). Heads emerge after only 21 days of growth in continuous light at a constant temperature of 25 C. In tests, USU-Perigee was found to outyield other full dwarf (defined as wheat cultivars: The yield advantage at a constant temperature of 23 C was found to be about 30 percent. Originally intended as a candidate food crop to be grown aboard spacecraft on long missions, this cultivar could also be grown in terrestrial growth chambers and could be useful for plant-physiology and -pathology studies.

Extreme value modelling of Ghana stock exchange index.

Science.gov (United States)

Nortey, Ezekiel N N; Asare, Kwabena; Mettle, Felix Okoe

2015-01-01

Modelling of extreme events has always been of interest in fields such as hydrology and meteorology. However, after the recent global financial crises, appropriate models for modelling of such rare events leading to these crises have become quite essential in the finance and risk management fields. This paper models the extreme values of the Ghana stock exchange all-shares index (2000-2010) by applying the extreme value theory (EVT) to fit a model to the tails of the daily stock returns data. A conditional approach of the EVT was preferred and hence an ARMA-GARCH model was fitted to the data to correct for the effects of autocorrelation and conditional heteroscedastic terms present in the returns series, before the EVT method was applied. The Peak Over Threshold approach of the EVT, which fits a Generalized Pareto Distribution (GPD) model to excesses above a certain selected threshold, was employed. Maximum likelihood estimates of the model parameters were obtained and the model's goodness of fit was assessed graphically using Q-Q, P-P and density plots. The findings indicate that the GPD provides an adequate fit to the data of excesses. The size of the extreme daily Ghanaian stock market movements were then computed using the value at risk and expected shortfall risk measures at some high quantiles, based on the fitted GPD model.

Star-forming Galaxies as AGN Imposters? A Theoretical Investigation of the Mid-infrared Colors of AGNs and Extreme Starbursts

Science.gov (United States)

Satyapal, Shobita; Abel, Nicholas P.; Secrest, Nathan J.

2018-05-01

We conduct for the first time a theoretical investigation of the mid-infrared spectral energy distribution (SED) produced by dust heated by an active galactic nucleus (AGN) and an extreme starburst. These models employ an integrated modeling approach using photoionization and stellar population synthesis models in which both the line and emergent continuum is predicted from gas exposed to the ionizing radiation from a young starburst and an AGN. In this work, we focus on the infrared colors from the Wide-field Infrared Survey Explorer, predicting the dependence of the colors on the input radiation field, the interstellar medium conditions, the obscuring column, and the metallicity. We find that an extreme starburst can mimic an AGN in two band mid-infrared color cuts employed in the literature. However, the three-band color cuts employed in the literature require starbursts with extremely high ionization parameters or gas densities. We show that the extreme mid-infrared colors seen in some blue compact dwarf galaxies are not due to metallicity but rather a combination of high ionization parameters and high column densities. Based on our theoretical calculations, we present a theoretical mid-infrared color cut that will exclude even the most extreme starburst that we have modeled in this work. The theoretical AGN demarcation region presented here can be used to identify elusive AGN candidates for future follow-up studies with the James Webb Space Telescope. The full suite of simulated SEDs are available online.

Risk of Adverse Cognitive or Behavioral Conditions and Psychiatric Disorders: Evidence Report

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Slack, Kelley J.; Williams, Thomas J.; Schneiderman, Jason S.; Whitmire, Alexandra M.; Picano, James J.; Leveton, Lauren B.; Schmidt, Lacey L.; Shea, Camille

2016-01-01

In April 2010, President Obama declared a space pioneering goal for the United States in general and NASA in particular. "Fifty years after the creation of NASA, our goal is no longer just a destination to reach. Our goal is the capacity for people to work and learn and operate and live safely beyond the Earth for extended periods of time, ultimately in ways that are more sustainable and even indefinite." Thus NASA's Strategic Objective 1.1 emerged as "expand human presence into the solar system and to the surface of Mars to advance exploration, science, innovation, benefits to humanity, and international collaboration" (NASA 2015b). Any space flight, be it of long or short duration, occurs in an extreme environment that has unique stressors. Even with excellent selection methods, the potential for behavioral problems among space flight crews remain a threat to mission success. Assessment of factors that are related to behavioral health can help minimize the chances of distress and, thus, reduce the likelihood of adverse cognitive or behavioral conditions and psychiatric disorders arising within a crew. Similarly, countermeasures that focus on prevention and treatment can mitigate the cognitive or behavioral conditions that, should they arise, would impact mission success. Given the general consensus that longer duration, isolation, and confined missions have a greater risk for behavioral health ensuring crew behavioral health over the long term is essential. Risk, which within the context of this report is assessed with respect to behavioral health and performance, is addressed to deter development of cognitive and behavioral degradations or psychiatric conditions in space flight and analog populations, and to monitor, detect, and treat early risk factors, predictors and other contributing factors. Based on space flight and analog evidence, the average incidence rate of an adverse behavioral health event occurring during a space mission is relatively low for the

Planetary and Space Simulation Facilities (PSI) at DLR

Science.gov (United States)

Panitz, Corinna; Rabbow, E.; Rettberg, P.; Kloss, M.; Reitz, G.; Horneck, G.

2010-05-01

organisms in space and will contribute to the understanding of the organic chemistry processes in space, the biological adaptation strategies to extreme conditions, e.g. on early Earth and Mars, and the distribution of life beyond its planet of origin The results gained during the simulation experiments demonstrated mission preparation as a basic requirement for successful and significant results of every space flight experiment. Hence, the Mission preparation program that was performed in the context of the space missions EXPOSE-E and EXPOSE-R proofed the outstanding importance and accentuated need for ground based experiments before and during a space mission. The facilities are also necessary for the performance of the ground control experiment during the mission, the so-called Mission Simulation Test (MST) under simulated space conditions, by parallel exposure of samples to simulated space parameters according to flight data received by telemetry. Finally the facilities also provide the possibility to simulate the surface and climate conditions of the planet Mars. In this way they offer the possibility to investigate under simulated Mars conditions the chances for development of life on Mars and to gain previous knowledge for the search for life on today's Mars and in this context especially the parameters for a manned mission to Mars. References [1] Rabbow E, Rettberg P, Panitz C, Drescher J, Horneck G, Reitz G (2005) SSIOUX - Space Simulation for Investigating Organics, Evolution and Exobiology, Adv. Space Res. 36 (2) 297-302, doi:10.1016/j.asr.2005.08.040Aman, A. and Bman, B. (1997) JGR, 90,1151-1154. [2] Fekete A, Modos K, Hegedüs M, Kovacs G, Ronto Gy, Peter A, Lammer H, Panitz C (2005) DNA Damage under simulated extraterrestrial conditions in bacteriophage T7 Adv. Space Res. 305-310Aman, A. et al. (1997) Meteoritics & Planet. Sci., 32,A74. [3] Cockell Ch, Schuerger AC, Billi D., Friedmann EI, Panitz C (2005) Effects of a Simulated Martian UV Flux on the

SPGD: A central power system for space title in French

International Nuclear Information System (INIS)

Widrig, R.D.

1991-01-01

This paper describes the Space Power Generation and Distribution (SPGD) concept for providing power to any satellite in earth orbit via power beaming. Other applications such as providing power for terrestrial or space exploration purposes are identified. An assessment of SPGD versus conventional space power is summarized concluding SPGD appears extremely attractive for our space future. 1 ref

Extreme-Ultraviolet Vortices from a Free-Electron Laser

Directory of Open Access Journals (Sweden)

Primož Rebernik Ribič

2017-08-01

Full Text Available Extreme-ultraviolet vortices may be exploited to steer the magnetic properties of nanoparticles, increase the resolution in microscopy, and gain insight into local symmetry and chirality of a material; they might even be used to increase the bandwidth in long-distance space communications. However, in contrast to the generation of vortex beams in the infrared and visible spectral regions, production of intense, extreme-ultraviolet and x-ray optical vortices still remains a challenge. Here, we present an in-situ and an ex-situ technique for generating intense, femtosecond, coherent optical vortices at a free-electron laser in the extreme ultraviolet. The first method takes advantage of nonlinear harmonic generation in a helical undulator, producing vortex beams at the second harmonic without the need for additional optical elements, while the latter one relies on the use of a spiral zone plate to generate a focused, micron-size optical vortex with a peak intensity approaching 10^{14}  W/cm^{2}, paving the way to nonlinear optical experiments with vortex beams at short wavelengths.

Occupants' adaptive responses and perception of thermal environment in naturally conditioned university classrooms

Energy Technology Data Exchange (ETDEWEB)

Yao, Runming [The School of Construction Management and Engineering, The University of Reading, Whiteknights, PO Box 219, Reading RG6 6AW (United Kingdom); The Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400042 (China); Liu, Jing [The School of Construction Management and Engineering, The University of Reading, Whiteknights, PO Box 219, Reading RG6 6AW (United Kingdom); Li, Baizhan [The Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing 400042 (China); Key Laboratory of the Three Gorges Reservoir Region' s Eco-Environment (Ministry of Education), Chongqing University, Chongqing 400042 (China)

2010-03-15

A year-long field study of the thermal environment in university classrooms was conducted from March 2005 to May 2006 in Chongqing, China. This paper presents the occupants' thermal sensation votes and discusses the occupants' adaptive response and perception of the thermal environment in a naturally conditioned space. Comparisons between the Actual Mean Vote (AMV) and Predicted Mean Vote (PMV) have been made as well as between the Actual Percentage of Dissatisfied (APD) and Predicted Percentage of Dissatisfied (PPD). The adaptive thermal comfort zone for the naturally conditioned space for Chongqing, which has hot summer and cold winter climatic characteristics, has been proposed based on the field study results. The Chongqing adaptive comfort range is broader than that of the ASHRAE Standard 55-2004 in general, but in the extreme cold and hot months, it is narrower. The thermal conditions in classrooms in Chongqing in summer and winter are severe. Behavioural adaptation such as changing clothing, adjusting indoor air velocity, taking hot/cold drinks, etc., as well as psychological adaptation, has played a role in adapting to the thermal environment. (author)

Direct venous thrombolysis and venous angioplasty in the upper extremity

International Nuclear Information System (INIS)

Hollmann, J.P.; Guenther, R.W.

1987-01-01

Venous thromboses of stenoses in the upper extremity are often the result of a compression syndrome of the shoulder girdle, the Paget-von Schroetter syndrome, vascular surgery, space-occupying lesions in the mediastinum or the result of catheterisation. Direct venous thrombolysis and venous angioplasty were performed successfully in six patients. (orig.) [de

Are extreme hydro-meteorological events a prerequisite for extreme water quality impacts? Exploring climate impacts on inland and coastal waters

Science.gov (United States)

Michalak, A. M.; Balaji, V.; Del Giudice, D.; Sinha, E.; Zhou, Y.; Ho, J. C.

2017-12-01

Questions surrounding water sustainability, climate change, and extreme events are often framed around water quantity - whether too much or too little. The massive impacts of extreme water quality impairments are equally compelling, however. Recent years have provided a host of compelling examples, with unprecedented harmful algal blooms developing along the West coast, in Utah Lake, in Lake Erie, and off the Florida coast, and huge hypoxic dead zones continuing to form in regions such as Lake Erie, the Chesapeake Bay, and the Gulf of Mexico. Linkages between climate change, extreme events, and water quality impacts are not well understood, however. Several factors explain this lack of understanding, including the relative complexity of underlying processes, the spatial and temporal scale mismatch between hydrologists and climatologists, and observational uncertainty leading to ambiguities in the historical record. Here, we draw on a number of recent studies that aim to quantitatively link meteorological variability and water quality impacts to test the hypothesis that extreme water quality impairments are the result of extreme hydro-meteorological events. We find that extreme hydro-meteorological events are neither always a necessary nor a sufficient condition for the occurrence of extreme water quality impacts. Rather, extreme water quality impairments often occur in situations where multiple contributing factors compound, which complicates both attribution of historical events and the ability to predict the future incidence of such events. Given the critical societal importance of water quality projections, a concerted program of uncertainty reduction encompassing observational and modeling components will be needed to examine situations where extreme weather plays an important, but not solitary, role in the chain of cause and effect.

Risk assessment of precipitation extremes in northern Xinjiang, China

Science.gov (United States)

Yang, Jun; Pei, Ying; Zhang, Yanwei; Ge, Quansheng

2018-05-01

This study was conducted using daily precipitation records gathered at 37 meteorological stations in northern Xinjiang, China, from 1961 to 2010. We used the extreme value theory model, generalized extreme value (GEV) and generalized Pareto distribution (GPD), statistical distribution function to fit outputs of precipitation extremes with different return periods to estimate risks of precipitation extremes and diagnose aridity-humidity environmental variation and corresponding spatial patterns in northern Xinjiang. Spatiotemporal patterns of daily maximum precipitation showed that aridity-humidity conditions of northern Xinjiang could be well represented by the return periods of the precipitation data. Indices of daily maximum precipitation were effective in the prediction of floods in the study area. By analyzing future projections of daily maximum precipitation (2, 5, 10, 30, 50, and 100 years), we conclude that the flood risk will gradually increase in northern Xinjiang. GEV extreme value modeling yielded the best results, proving to be extremely valuable. Through example analysis for extreme precipitation models, the GEV statistical model was superior in terms of favorable analog extreme precipitation. The GPD model calculation results reflect annual precipitation. For most of the estimated sites' 2 and 5-year T for precipitation levels, GPD results were slightly greater than GEV results. The study found that extreme precipitation reaching a certain limit value level will cause a flood disaster. Therefore, predicting future extreme precipitation may aid warnings of flood disaster. A suitable policy concerning effective water resource management is thus urgently required.

Characterization of extremely low frequency magnetic fields from diesel, gasoline and hybrid cars under controlled conditions.

Science.gov (United States)

Hareuveny, Ronen; Sudan, Madhuri; Halgamuge, Malka N; Yaffe, Yoav; Tzabari, Yuval; Namir, Daniel; Kheifets, Leeka

2015-01-30

This study characterizes extremely low frequency (ELF) magnetic field (MF) levels in 10 car models. Extensive measurements were conducted in three diesel, four gasoline, and three hybrid cars, under similar controlled conditions and negligible background fields. Averaged over all four seats under various driving scenarios the fields were lowest in diesel cars (0.02 μT), higher for gasoline (0.04-0.05 μT) and highest in hybrids (0.06-0.09 μT), but all were in-line with daily exposures from other sources. Hybrid cars had the highest mean and 95th percentile MF levels, and an especially large percentage of measurements above 0.2 μT. These parameters were also higher for moving conditions compared to standing while idling or revving at 2500 RPM and higher still at 80 km/h compared to 40 km/h. Fields in non-hybrid cars were higher at the front seats, while in hybrid cars they were higher at the back seats, particularly the back right seat where 16%-69% of measurements were greater than 0.2 μT. As our results do not include low frequency fields (below 30 Hz) that might be generated by tire rotation, we suggest that net currents flowing through the cars' metallic chassis may be a possible source of MF. Larger surveys in standardized and well-described settings should be conducted with different types of vehicles and with spectral analysis of fields including lower frequencies due to magnetization of tires.

Ni-Ti Next Generation Bearings for Space Applications

Science.gov (United States)

DellaCorte, Christopher

2018-01-01

NASA applications challenge traditional bearing materials. The rigors of launch often include heavy shock loads and exposure to corrosive environments (e.g., salt spray). Unfortunately, ball and roller bearings made from hardened steels are vulnerable to Brinell denting and rust which can limit performance and life. Ceramic materials can eliminate corrosion concerns but their high stiffness and extreme hardness actually makes denting problems worse. In this presentation, an emerging superelastic alloy, NiTi, is introduced for rolling element bearing applications. Through a decade of RD, NiTi alloy bearings have been put through a comprehensive series of life and performance tests. Hardness, corrosion, strength, stiffness, and rolling contact fatigue tests have been conducted and reported. Ball bearings ranging in size from 12 to 50mm bore have been successfully engineered and operated over a wide range of speeds and test conditions including being submerged in water. The combination of high hardness, moderate elastic modulus, low density, and intrinsic corrosion immunity provide new possibilities for mechanisms that operate under extreme conditions. Recent preliminary tests indicate that bearings can be made from NiTi alloys that are easily lubricated by conventional oils and greases and exhibit acceptable rolling contact fatigue resistance. This presentation introduces the NiTi materials systems and shows how NASA is using it to alleviate several specific problems encountered in advanced space applications.

Regularization in Hilbert space under unbounded operators and general source conditions

International Nuclear Information System (INIS)

Hofmann, Bernd; Mathé, Peter; Von Weizsäcker, Heinrich

2009-01-01

The authors study ill-posed equations with unbounded operators in Hilbert space. This setup has important applications, but only a few theoretical studies are available. First, the question is addressed and answered whether every element satisfies some general source condition with respect to a given self-adjoint unbounded operator. This generalizes a previous result from Mathé and Hofmann (2008 Inverse Problems 24 015009). The analysis then proceeds to error bounds for regularization, emphasizing some specific points for regularization under unbounded operators. The study finally reviews two examples within the light of the present study, as these are fractional differentiation and some Cauchy problems for the Helmholtz equation, both studied previously and in more detail by U Tautenhahn and co-authors

Properties of a planar electric double layer under extreme conditions investigated by classical density functional theory and Monte Carlo simulations.

Science.gov (United States)

Zhou, Shiqi; Lamperski, Stanisław; Zydorczak, Maria

2014-08-14

Monte Carlo (MC) simulation and classical density functional theory (DFT) results are reported for the structural and electrostatic properties of a planar electric double layer containing ions having highly asymmetric diameters or valencies under extreme concentration condition. In the applied DFT, for the excess free energy contribution due to the hard sphere repulsion, a recently elaborated extended form of the fundamental measure functional is used, and coupling of Coulombic and short range hard-sphere repulsion is described by a traditional second-order functional perturbation expansion approximation. Comparison between the MC and DFT results indicates that validity interval of the traditional DFT approximation expands to high ion valences running up to 3 and size asymmetry high up to diameter ratio of 4 whether the high valence ions or the large size ion are co- or counter-ions; and to a high bulk electrolyte concentration being close to the upper limit of the electrolyte mole concentration the MC simulation can deal with well. The DFT accuracy dependence on the ion parameters can be self-consistently explained using arguments of liquid state theory, and new EDL phenomena such as overscreening effect due to monovalent counter-ions, extreme layering effect of counter-ions, and appearance of a depletion layer with almost no counter- and co-ions are observed.

Expose-R experiment on effects of open space condition on survivorship in dormant stages of aquatic invertebrates

Science.gov (United States)

Alekseev, Victor; Novikova, Nataliya; Levinskikh, Margarita; Sychev, Vladimir; Yusoff, Fatimah; Azuraidi, Osman

2012-07-01

Dormancy protects animals and plants in harsh environmental conditions from months up to hundred years. This phenomenon is perspective for space researches especially for interplanetary missions. Direct experiments in open space BYORYSK supported in principle the fact of survivorship of bacteria, fungi spores, seed of plants and crustacean dormant cysts. Even though the rate of survivorship in long-term treatments was low but good enough to conclude that biological invasion even to Mars is a real danger. As soon as the BYORYSK lunch was made of metal the possibility for resting stages to survive under UV treatment in vacuum without some protection was not clear. To test it an ESA and RSA equipment titled EXPOSE-R was applied. The EXPOSE-R facility was an external facility attached to the outside of the Zvezda Service Module in ISS in the end of November 2008. It had glace windows transparent for UV-radiation and possibility to measure temperature, space- and UV-radiation. Among a number of experiments requiring exposure to the open space environment it had a biological launch containing resting stages of terrestrial and aquatic organisms. These stages included dried ephippia of cladoceran Daphnia magna differentiated on size, dormant eggs of ostracode Eucypris ornate, cysts of fair-shrimp Streptocephalus torvicornis ( all from hemi desert Caspian area) and Artemis salina from salt lake Crimean populations. All dormant stages were kept in transparent to UV plastic bags placed in three layers. After about two years of exposing in open space dormant stages of 3 species A. salina, D. magna, S. torvicornis successfully survived at different scales but in second and third layers only . The highest level of survivorship was found in A. salina cysts. In preliminary land experiments that imitated land EXPOSE imitation of outside space station UV and vacuum conditions survivorship in resting eggs of D .magna, S. torvicornis and E. ornate was tested also. The total UV dose of

Sediment Dynamics Within Buffer Zone and Sinkhole Splay Areas Under Extreme Soil Disturbance Conditions.

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