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.

GIS oriented analysis of tourist time-space patterns to support sustainable tourism development

NARCIS (Netherlands)

Knaap, van der W.G.M.

1999-01-01

Tourism and tourism development create major changes in the environment. To determine their impact on environmental sustainability, it is necessary to understand tourist behaviour. Time, space and context are important components in describing tourist time-space behaviour. Tourist time-space

Applications of neural networks to real-time data processing at the Environmental and Molecular Sciences Laboratory (EMSL)

International Nuclear Information System (INIS)

Keller, P.E.; Kouzes, R.T.; Kangas, L.J.

1993-06-01

Detailed design of the Environmental and Molecular Sciences Laboratory (EMSL) at the Pacific Northwest Laboratory (PNL) is nearing completion and construction is scheduled to begin later this year. This facility will assist in the environmental restoration and waste management mission at the Hanford Site. This paper identifies several real-time data processing applications within the EMSL where neural networks can potentially be beneficial. These applications include real-time sensor data acquisition and analysis, spectral analysis, process control, theoretical modeling, and data compression

Space Environmental Effects Knowledgebase

Science.gov (United States)

Wood, B. E.

2007-01-01

This report describes the results of an NRA funded program entitled Space Environmental Effects Knowledgebase that received funding through a NASA NRA (NRA8-31) and was monitored by personnel in the NASA Space Environmental Effects (SEE) Program. The NASA Project number was 02029. The Satellite Contamination and Materials Outgassing Knowledgebase (SCMOK) was created as a part of the earlier NRA8-20. One of the previous tasks and part of the previously developed Knowledgebase was to accumulate data from facilities using QCMs to measure the outgassing data for satellite materials. The main object of this current program was to increase the number of material outgassing datasets from 250 up to approximately 500. As a part of this effort, a round-robin series of materials outgassing measurements program was also executed that allowed comparison of the results for the same materials tested in 10 different test facilities. Other programs tasks included obtaining datasets or information packages for 1) optical effects of contaminants on optical surfaces, thermal radiators, and sensor systems and 2) space environmental effects data and incorporating these data into the already existing NASA/SEE Knowledgebase.

The manifold model for space-time

International Nuclear Information System (INIS)

Heller, M.

1981-01-01

Physical processes happen on a space-time arena. It turns out that all contemporary macroscopic physical theories presuppose a common mathematical model for this arena, the so-called manifold model of space-time. The first part of study is an heuristic introduction to the concept of a smooth manifold, starting with the intuitively more clear concepts of a curve and a surface in the Euclidean space. In the second part the definitions of the Csub(infinity) manifold and of certain structures, which arise in a natural way from the manifold concept, are given. The role of the enveloping Euclidean space (i.e. of the Euclidean space appearing in the manifold definition) in these definitions is stressed. The Euclidean character of the enveloping space induces to the manifold local Euclidean (topological and differential) properties. A suggestion is made that replacing the enveloping Euclidean space by a discrete non-Euclidean space would be a correct way towards the quantization of space-time. (author)

Federal environmental assessment panel process

International Nuclear Information System (INIS)

Edwards, R.A.; King, J.M.

1996-01-01

The Government of Canada inaugurated an environmental assessment process in 1973. Since that time, the Department of Natural Resources, or its predecessor, the Department of Energy Mines and Resources, and industrial clients of the Department, have been major participants in the process. In 1995, the authors interviewed representatives of a number of client industries and selected individuals, to ask their opinion of the public hearing part of the environmental assessment process, with the objective of identifying shortcomings and proposing improvements. Respondents criticized the hearings as costly, time-wasting, bureaucratic, and uncertain in cost, time, and outcome. A number of observations on noted areas of shortcoming are presented in this paper, with suggestions for improvement

Federal environmental assessment panel process

Energy Technology Data Exchange (ETDEWEB)

Edwards, R A; King, J M [Natural Resources Canada, Ottawa, ON (Canada)

1997-12-31

The Government of Canada inaugurated an environmental assessment process in 1973. Since that time, the Department of Natural Resources, or its predecessor, the Department of Energy Mines and Resources, and industrial clients of the Department, have been major participants in the process. In 1995, the authors interviewed representatives of a number of client industries and selected individuals, to ask their opinion of the public hearing part of the environmental assessment process, with the objective of identifying shortcomings and proposing improvements. Respondents criticized the hearings as costly, time-wasting, bureaucratic, and uncertain in cost, time, and outcome. A number of observations on noted areas of shortcoming are presented in this paper, with suggestions for improvement.

Earth Observation from Space - The Issue of Environmental Sustainability

Science.gov (United States)

Durrieu, Sylvie; Nelson, Ross F.

2013-01-01

Remote sensing scientists work under assumptions that should not be taken for granted and should, therefore, be challenged. These assumptions include the following: 1. Space, especially Low Earth Orbit (LEO), will always be available to governmental and commercial space entities that launch Earth remote sensing missions. 2. Space launches are benign with respect to environmental impacts. 3. Minimization of Type 1 error, which provides increased confidence in the experimental outcome, is the best way to assess the significance of environmental change. 4. Large-area remote sensing investigations, i.e. national, continental, global studies, are best done from space. 5. National space missions should trump international, cooperative space missions to ensure national control and distribution of the data products. At best, all of these points are arguable, and in some cases, they're wrong. Development of observational space systems that are compatible with sustainability principles should be a primary concern when Earth remote sensing space systems are envisioned, designed, and launched. The discussion is based on the hypothesis that reducing the environmental impacts of thedata acquisition step,which is at the very beginning of the information streamleading to decision and action, will enhance coherence in the information streamand strengthen the capacity of measurement processes to meet their stated functional goal, i.e. sustainable management of Earth resources. We suggest that unconventional points of view should be adopted and when appropriate, remedial measures considered that could help to reduce the environmental footprint of space remote sensing and of Earth observation and monitoring systems in general. This article discusses these five assumptions inthe contextof sustainablemanagementof Earth's resources. Takingeachassumptioninturn,we find the following: (1) Space debris may limit access to Low Earth Orbit over the next decades. (2) Relatively speaking, given

Space time modelling of air quality for environmental-risk maps: A case study in South Portugal

Science.gov (United States)

Soares, Amilcar; Pereira, Maria J.

2007-10-01

Since the 1960s, there has been a strong industrial development in the Sines area, on the southern Atlantic coast of Portugal, including the construction of an important industrial harbour and of, mainly, petrochemical and energy-related industries. These industries are, nowadays, responsible for substantial emissions of SO2, NOx, particles, VOCs and part of the ozone polluting the atmosphere. The major industries are spatially concentrated in a restricted area, very close to populated areas and natural resources such as those protected by the European Natura 2000 network. Air quality parameters are measured at the emissions' sources and at a few monitoring stations. Although air quality parameters are measured on an hourly basis, the lack of representativeness in space of these non-homogeneous phenomena makes even their representativeness in time questionable. Hence, in this study, the regional spatial dispersion of contaminants is also evaluated, using diffusive-sampler (Radiello Passive Sampler) campaigns during given periods. Diffusive samplers cover the entire space extensively, but just for a limited period of time. In the first step of this study, a space-time model of pollutants was built, based on a stochastic simulation-direct sequential simulation-with local spatial trend. The spatial dispersion of the contaminants for a given period of time-corresponding to the exposure time of the diffusive samplers-was computed by ordinary kriging. Direct sequential simulation was applied to produce equiprobable spatial maps for each day of that period, using the kriged map as a spatial trend and the daily measurements of pollutants from the monitoring stations as hard data. In the second step, the following environmental risk and costs maps were computed from the set of simulated realizations of pollutants: (i) maps of the contribution of each emission to the pollutant concentration at any spatial location; (ii) costs of badly located monitoring stations.

On discrete models of space-time

International Nuclear Information System (INIS)

Horzela, A.; Kempczynski, J.; Kapuscik, E.; Georgia Univ., Athens, GA; Uzes, Ch.

1992-02-01

Analyzing the Einstein radiolocation method we come to the conclusion that results of any measurement of space-time coordinates should be expressed in terms of rational numbers. We show that this property is Lorentz invariant and may be used in the construction of discrete models of space-time different from the models of the lattice type constructed in the process of discretization of continuous models. (author)

Proceedings of the Goddard Space Flight Center Workshop on Robotics for Commercial Microelectronic Processes in Space

Science.gov (United States)

1987-01-01

Potential applications of robots for cost effective commercial microelectronic processes in space were studied and the associated robotic requirements were defined. Potential space application areas include advanced materials processing, bulk crystal growth, and epitaxial thin film growth and related processes. All possible automation of these processes was considered, along with energy and environmental requirements. Aspects of robot capabilities considered include system intelligence, ROM requirements, kinematic and dynamic specifications, sensor design and configuration, flexibility and maintainability. Support elements discussed included facilities, logistics, ground support, launch and recovery, and management systems.

Space-time interdependence: evidence against asymmetric mapping between time and space.

Science.gov (United States)

Cai, Zhenguang G; Connell, Louise

2015-03-01

Time and space are intimately related, but what is the real nature of this relationship? Is time mapped metaphorically onto space such that effects are always asymmetric (i.e., space affects time more than time affects space)? Or do the two domains share a common representational format and have the ability to influence each other in a flexible manner (i.e., time can sometimes affect space more than vice versa)? In three experiments, we examined whether spatial representations from haptic perception, a modality of relatively low spatial acuity, would lead the effect of time on space to be substantially stronger than the effect of space on time. Participants touched (but could not see) physical sticks while listening to an auditory note, and then reproduced either the length of the stick or the duration of the note. Judgements of length were affected by concurrent stimulus duration, but not vice versa. When participants were allowed to see as well as touch the sticks, however, the higher acuity of visuohaptic perception caused the effects to converge so length and duration influenced each other to a similar extent. These findings run counter to the spatial metaphor account of time, and rather support the spatial representation account in which time and space share a common representational format and the directionality of space-time interaction depends on the perceptual acuity of the modality used to perceive space. Copyright © 2014 Elsevier B.V. All rights reserved.

The space-time model according to dimensional continuous space-time theory

International Nuclear Information System (INIS)

Martini, Luiz Cesar

2014-01-01

This article results from the Dimensional Continuous Space-Time Theory for which the introductory theoretician was presented in [1]. A theoretical model of the Continuous Space-Time is presented. The wave equation of time into absolutely stationary empty space referential will be described in detail. The complex time, that is the time fixed on the infinite phase time speed referential, is deduced from the New View of Relativity Theory that is being submitted simultaneously with this article in this congress. Finally considering the inseparable Space-Time is presented the duality equation wave-particle.

Trajectory data analyses for pedestrian space-time activity study.

Science.gov (United States)

Qi, Feng; Du, Fei

2013-02-25

It is well recognized that human movement in the spatial and temporal dimensions has direct influence on disease transmission(1-3). An infectious disease typically spreads via contact between infected and susceptible individuals in their overlapped activity spaces. Therefore, daily mobility-activity information can be used as an indicator to measure exposures to risk factors of infection. However, a major difficulty and thus the reason for paucity of studies of infectious disease transmission at the micro scale arise from the lack of detailed individual mobility data. Previously in transportation and tourism research detailed space-time activity data often relied on the time-space diary technique, which requires subjects to actively record their activities in time and space. This is highly demanding for the participants and collaboration from the participants greatly affects the quality of data(4). Modern technologies such as GPS and mobile communications have made possible the automatic collection of trajectory data. The data collected, however, is not ideal for modeling human space-time activities, limited by the accuracies of existing devices. There is also no readily available tool for efficient processing of the data for human behavior study. We present here a suite of methods and an integrated ArcGIS desktop-based visual interface for the pre-processing and spatiotemporal analyses of trajectory data. We provide examples of how such processing may be used to model human space-time activities, especially with error-rich pedestrian trajectory data, that could be useful in public health studies such as infectious disease transmission modeling. The procedure presented includes pre-processing, trajectory segmentation, activity space characterization, density estimation and visualization, and a few other exploratory analysis methods. Pre-processing is the cleaning of noisy raw trajectory data. We introduce an interactive visual pre-processing interface as well as an

Time and Space in Digital Game Storytelling

Directory of Open Access Journals (Sweden)

Huaxin Wei

2010-01-01

Full Text Available The design and representation of time and space are important in any narrative form. Not surprisingly there is an extensive literature on specific considerations of space or time in game design. However, there is less attention to more systematic analyses that examine both of these key factors—including their dynamic interrelationship within game storytelling. This paper adapts critical frameworks of narrative space and narrative time drawn from other media and demonstrates their application in the understanding of game narratives. In order to do this we incorporate fundamental concepts from the field of game studies to build a game-specific framework for analyzing the design of narrative time and narrative space. The paper applies this framework against a case analysis in order to demonstrate its operation and utility. This process grounds the understanding of game narrative space and narrative time in broader traditions of narrative discourse and analysis.

Academic Training: Real Time Process Control - Lecture series

CERN Multimedia

Françoise Benz

2004-01-01

ACADEMIC TRAINING LECTURE REGULAR PROGRAMME 7, 8 and 9 June From 11:00 hrs to 12:00 hrs - Main Auditorium bldg. 500 Real Time Process Control T. Riesco / CERN-TS What exactly is meant by Real-time? There are several definitions of real-time, most of them contradictory. Unfortunately the topic is controversial, and there does not seem to be 100% agreement over the terminology. Real-time applications are becoming increasingly important in our daily lives and can be found in diverse environments such as the automatic braking system on an automobile, a lottery ticket system, or robotic environmental samplers on a space station. These lectures will introduce concepts and theory like basic concepts timing constraints, task scheduling, periodic server mechanisms, hard and soft real-time.ENSEIGNEMENT ACADEMIQUE ACADEMIC TRAINING Françoise Benz 73127 academic.training@cern.ch

Just in Time in Space or Space Based JIT

Science.gov (United States)

VanOrsdel, Kathleen G.

1995-01-01

Our satellite systems are mega-buck items. In today's cost conscious world, we need to reduce the overall costs of satellites if our space program is to survive. One way to accomplish this would be through on-orbit maintenance of parts on the orbiting craft. In order to accomplish maintenance at a low cost I advance the hypothesis of having parts and pieces (spares) waiting. Waiting in the sense of having something when you need it, or just-in-time. The JIT concept can actually be applied to space processes. Its definition has to be changed just enough to encompass the needs of space. Our space engineers tell us which parts and pieces the satellite systems might be needing once in orbit. These items are stored in space for the time of need and can be ready when they are needed -- or Space Based JIT. When a system has a problem, the repair facility is near by and through human or robotics intervention, it can be brought back into service. Through a JIT process, overall system costs could be reduced as standardization of parts is built into satellite systems to facilitate reduced numbers of parts being stored. Launch costs will be contained as fewer spare pieces need to be included in the launch vehicle and the space program will continue to thrive even in this era of reduced budgets. The concept of using an orbiting parts servicer and human or robotics maintenance/repair capabilities would extend satellite life-cycle and reduce system replacement launches. Reductions of this nature throughout the satellite program result in cost savings.

Quantum relativity theory and quantum space-time

International Nuclear Information System (INIS)

Banai, M.

1984-01-01

A quantum relativity theory formulated in terms of Davis' quantum relativity principle is outlined. The first task in this theory as in classical relativity theory is to model space-time, the arena of natural processes. It is shown that the quantum space-time models of Banai introduced in another paper is formulated in terms of Davis's quantum relativity. The recently proposed classical relativistic quantum theory of Prugovecki and his corresponding classical relativistic quantum model of space-time open the way to introduce, in a consistent way, the quantum space-time model (the quantum substitute of Minkowski space) of Banai proposed in the paper mentioned. The goal of quantum mechanics of quantum relativistic particles living in this model of space-time is to predict the rest mass system properties of classically relativistic (massive) quantum particles (''elementary particles''). The main new aspect of this quantum mechanics is that it provides a true mass eigenvalue problem, and that the excited mass states of quantum relativistic particles can be interpreted as elementary particles. The question of field theory over quantum relativistic model of space-time is also discussed. Finally it is suggested that ''quarks'' should be considered as quantum relativistic particles. (author)

Composable Data Processing in Environmental Science - A Process View

NARCIS (Netherlands)

Wombacher, Andreas

Data processing in environmental science is essential for doing science. The heterogeneity of data sources, data processing operations and infrastructures results in a lot of manual data and process integration work done by each scientist individually. This is very inefficient and time consuming.

Real space process algebra

NARCIS (Netherlands)

Bergstra, J.A.; Baeten, J.C.M.

1993-01-01

The real time process algebra of Baeten and Bergstra [Formal Aspects of Computing, 3, 142-188 (1991)] is extended to real space by requiring the presence of spatial coordinates for each atomic action, in addition to the required temporal attribute. It is found that asynchronous communication

Quantum field theory in curved space-time

Energy Technology Data Exchange (ETDEWEB)

Davies, P C.W. [King' s Coll., London (UK)

1976-09-30

It is stated that recent theoretical developments indicate that the presence of gravity (curved space-time) can give rise to important new quantum effects, such as cosmological particle production and black-hole evaporation. These processes suggest intriguing new relations between quantum theory, thermodynamics and space-time structure and encourage the hope that a better understanding of a full quantum theory of gravity may emerge from this approach.

Proceedings of the 4th Conference on Aerospace Materials, Processes, and Environmental Technology

Science.gov (United States)

Griffin, D. E. (Editor); Stanley, D. C. (Editor)

2001-01-01

The next millennium challenges us to produce innovative materials, processes, manufacturing, and environmental technologies that meet low-cost aerospace transportation needs while maintaining US leadership. The pursuit of advanced aerospace materials, manufacturing processes, and environmental technologies supports the development of safer, operational, next-generation, reusable, and expendable aeronautical and space vehicle systems. The Aerospace Materials, Processes, and Environmental Technology Conference (AMPET) provided a forum for manufacturing, environmental, materials, and processes engineers, scientists, and managers to describe, review, and critically assess advances in these key technology areas.

25th Space Simulation Conference. Environmental Testing: The Earth-Space Connection

Science.gov (United States)

Packard, Edward

2008-01-01

Topics covered include: Methods of Helium Injection and Removal for Heat Transfer Augmentation; The ESA Large Space Simulator Mechanical Ground Support Equipment for Spacecraft Testing; Temperature Stability and Control Requirements for Thermal Vacuum/Thermal Balance Testing of the Aquarius Radiometer; The Liquid Nitrogen System for Chamber A: A Change from Original Forced Flow Design to a Natural Flow (Thermo Siphon) System; Return to Mercury: A Comparison of Solar Simulation and Flight Data for the MESSENGER Spacecraft; Floating Pressure Conversion and Equipment Upgrades of Two 3.5kw, 20k, Helium Refrigerators; Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load; Special ISO Class 6 Cleanroom for the Lunar Reconnaissance Orbiter (LRO) Project; A State-of-the-Art Contamination Effects Research and Test Facility Martian Dust Simulator; Cleanroom Design Practices and Their Influence on Particle Counts; Extra Terrestrial Environmental Chamber Design; Contamination Sources Effects Analysis (CSEA) - A Tool to Balance Cost/Schedule While Managing Facility Availability; SES and Acoustics at GSFC; HST Super Lightweight Interchangeable Carrier (SLIC) Static Test; Virtual Shaker Testing: Simulation Technology Improves Vibration Test Performance; Estimating Shock Spectra: Extensions beyond GEVS; Structural Dynamic Analysis of a Spacecraft Multi-DOF Shaker Table; Direct Field Acoustic Testing; Manufacture of Cryoshroud Surfaces for Space Simulation Chambers; The New LOTIS Test Facility; Thermal Vacuum Control Systems Options for Test Facilities; Extremely High Vacuum Chamber for Low Outgassing Processing at NASA Goddard; Precision Cleaning - Path to Premier; The New Anechoic Shielded Chambers Designed for Space and Commercial Applications at LIT; Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar; Thermal (Silicon Diode) Data Acquisition System; Aquarius's Instrument Science Data System (ISDS) Automated

ENVIRONMENTAL IMPACTS IN THE PROCESS OF SOCIAL OWNERSHIP OF SPACE IN THE BAY OF THE PONTAL IN MUNICIPALITY OF ILHÉUS / BA

Directory of Open Access Journals (Sweden)

Emilson Batista da Silva

2014-07-01

Full Text Available This study is about the relationship between society and nature, considering the impact of the appropriation of space in the estuary of Pontal Bay -Ilhéus/BA. The time frame adopted begins with the 70s and extends until the year 2012. The research approach was qualitative, adopting quantitative techniques when necessary. The instruments of collection consisted of systematic observation and interview, plus documentary and bibliographic research. The analyzes showed evidence that the socio-spatial interventions in the Bay originate from the construction of the Port of Ilheus in the northern portion, from the growing, environmental degradation of river basins tributaries (rivers Cachoeira, Santana and Itacanoeira and from the process of occupation surrounding the Bay. These pressures have caused changes in the dynamics of estuarine circulation, leading to a state of beach progradation, intensifying the process of silting up of the Bay, propension to formation of mangroves and impaired water quality due to discharge of sewage.

Space Environmental Effects Testing Capability at the Marshall Space Flight Center

Science.gov (United States)

DeWittBurns, H.; Craven, Paul; Finckenor, Miria; Nehls, Mary; Schneider, Todd; Vaughn, Jason

2012-01-01

Understanding the effects of the space environment on materials and systems is fundamental and essential for mission success. If not properly understood and designed for, the effects of the environment can lead to degradation of materials, reduction of functional lifetime, and system failure. In response to this need, the Marshall Space Flight Center has developed world class Space Environmental Effects (SEE) expertise and test facilities to simulate the space environment. Capabilities include multiple unique test systems comprising the most complete SEE testing capability available. These test capabilities include charged particle radiation (electrons, protons, ions), ultraviolet radiation (UV), vacuum ultraviolet radiation (VUV), atomic oxygen, plasma effects, space craft charging, lunar surface and planetary effects, vacuum effects, and hypervelocity impacts as well as the combination of these capabilities. In addition to the uniqueness of the individual test capabilities, MSFC is the only NASA facility where the effects of the different space environments can be tested in one location. Combined with additional analytical capabilities for pre- and post-test evaluation, MSFC is a one-stop shop for materials testing and analysis. The SEE testing and analysis are performed by a team of award winning experts nationally recognized for their contributions in the study of the effects of the space environment on materials and systems. With this broad expertise in space environmental effects and the variety of test systems and equipment available, MSFC is able to customize tests with a demonstrated ability to rapidly adapt and reconfigure systems to meet customers needs. Extensive flight experiment experience bolsters this simulation and analysis capability with a comprehensive understanding of space environmental effects.

Integrated Atmosphere Resource Recovery and Environmental Monitoring Technology Demonstration for Deep Space Exploration

Science.gov (United States)

Perry, Jay L.; Abney, Morgan B.; Knox, James C.; Parrish, Keith J.; Roman, Monserrate C.; Jan, Darrell L.

2012-01-01

Exploring the frontiers of deep space continues to be defined by the technological challenges presented by safely transporting a crew to and from destinations of scientific interest. Living and working on that frontier requires highly reliable and efficient life support systems that employ robust, proven process technologies. The International Space Station (ISS), including its environmental control and life support (ECLS) system, is the platform from which humanity's deep space exploration missions begin. The ISS ECLS system Atmosphere Revitalization (AR) subsystem and environmental monitoring (EM) technical architecture aboard the ISS is evaluated as the starting basis for a developmental effort being conducted by the National Aeronautics and Space Administration (NASA) via the Advanced Exploration Systems (AES) Atmosphere Resource Recovery and Environmental Monitoring (ARREM) Project.. An evolutionary approach is employed by the ARREM project to address the strengths and weaknesses of the ISS AR subsystem and EM equipment, core technologies, and operational approaches to reduce developmental risk, improve functional reliability, and lower lifecycle costs of an ISS-derived subsystem architecture suitable for use for crewed deep space exploration missions. The most promising technical approaches to an ISS-derived subsystem design architecture that incorporates promising core process technology upgrades will be matured through a series of integrated tests and architectural trade studies encompassing expected exploration mission requirements and constraints.

A latent process model for forecasting multiple time series in environmental public health surveillance.

Science.gov (United States)

Morrison, Kathryn T; Shaddick, Gavin; Henderson, Sarah B; Buckeridge, David L

2016-08-15

This paper outlines a latent process model for forecasting multiple health outcomes arising from a common environmental exposure. Traditionally, surveillance models in environmental health do not link health outcome measures, such as morbidity or mortality counts, to measures of exposure, such as air pollution. Moreover, different measures of health outcomes are treated as independent, while it is known that they are correlated with one another over time as they arise in part from a common underlying exposure. We propose modelling an environmental exposure as a latent process, and we describe the implementation of such a model within a hierarchical Bayesian framework and its efficient computation using integrated nested Laplace approximations. Through a simulation study, we compare distinct univariate models for each health outcome with a bivariate approach. The bivariate model outperforms the univariate models in bias and coverage of parameter estimation, in forecast accuracy and in computational efficiency. The methods are illustrated with a case study using healthcare utilization and air pollution data from British Columbia, Canada, 2003-2011, where seasonal wildfires produce high levels of air pollution, significantly impacting population health. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Physical models on discrete space and time

International Nuclear Information System (INIS)

Lorente, M.

1986-01-01

The idea of space and time quantum operators with a discrete spectrum has been proposed frequently since the discovery that some physical quantities exhibit measured values that are multiples of fundamental units. This paper first reviews a number of these physical models. They are: the method of finite elements proposed by Bender et al; the quantum field theory model on discrete space-time proposed by Yamamoto; the finite dimensional quantum mechanics approach proposed by Santhanam et al; the idea of space-time as lattices of n-simplices proposed by Kaplunovsky et al; and the theory of elementary processes proposed by Weizsaecker and his colleagues. The paper then presents a model proposed by the authors and based on the (n+1)-dimensional space-time lattice where fundamental entities interact among themselves 1 to 2n in order to build up a n-dimensional cubic lattice as a ground field where the physical interactions take place. The space-time coordinates are nothing more than the labelling of the ground field and take only discrete values. 11 references

Sparsity-Based Space-Time Adaptive Processing Using OFDM Radar

Energy Technology Data Exchange (ETDEWEB)

Sen, Satyabrata [ORNL

2012-01-01

We propose a sparsity-based space-time adaptive processing (STAP) algorithm to detect a slowly-moving target using an orthogonal frequency division multiplexing (OFDM) radar. We observe that the target and interference spectra are inherently sparse in the spatio-temporal domain, and hence we exploit that sparsity to develop an efficient STAP technique. In addition, the use of an OFDM signal increases the frequency diversity of our system, as different scattering centers of a target resonate at different frequencies, and thus improves the target detectability. First, we formulate a realistic sparse-measurement model for an OFDM radar considering both the clutter and jammer as the interfering sources. Then, we show that the optimal STAP-filter weight-vector is equal to the generalized eigenvector corresponding to the minimum generalized eigenvalue of the interference and target covariance matrices. To estimate the target and interference covariance matrices, we apply a residual sparse-recovery technique that enables us to incorporate the partially known support of the sparse vector. Our numerical results demonstrate that the sparsity-based STAP algorithm, with considerably lesser number of secondary data, produces an equivalent performance as the other existing STAP techniques.

Space station environmental control and life support systems test bed program - an overview

Science.gov (United States)

Behrend, Albert F.

As the National Aeronautics and Space Administration (NASA) begins to intensify activities for development of the Space Station, decisions must be made concerning the technical state of the art that will be baselined for the initial Space Station system. These decisions are important because significant potential exists for enhancing system performance and for reducing life-cycle costs. However, intelligent decisions cannot be made without an adequate assessment of new and ready technologies, i.e., technologies which are sufficiently mature to allow predevelopment demonstrations to prove their application feasibility and to quantify the risk associated with their development. Therefore, the NASA has implemented a technology development program which includes the establishment of generic test bed capabilities in which these new technologies and approaches can be tested at the prototype level. One major Space Station subsystem discipline in which this program has been implemented is the environmental control and life support system (ECLSS). Previous manned space programs such as Gemini, Apollo, and Space Shuttle have relied heavily on consumables to provide environmental control and life support services. However, with the advent of a long-duration Space Station, consumables must be reduced within technological limits to minimize Space Station resupply penalties and operational costs. The use of advanced environmental control and life support approaches involving regenerative processes offers the best solution for significant consumables reduction while also providing system evolutionary growth capability. Consequently, the demonstration of these "new technologies" as viable options for inclusion in the baseline that will be available to support a Space Station initial operational capability in the early 1990's becomes of paramount importance. The mechanism by which the maturity of these new regenerative life support technologies will be demonstrated is the Space

Time-space noncommutativity: quantised evolutions

International Nuclear Information System (INIS)

Balachandran, Aiyalam P.; Govindarajan, Thupil R.; Teotonio-Sobrinho, Paulo; Martins, Andrey Gomes

2004-01-01

In previous work, we developed quantum physics on the Moyal plane with time-space noncommutativity, basing ourselves on the work of Doplicher et al. Here we extend it to certain noncommutative versions of the cylinder, R 3 and Rx S 3 . In all these models, only discrete time translations are possible, a result known before in the first two cases. One striking consequence of quantised time translations is that even though a time independent hamiltonian is an observable, in scattering processes, it is conserved only modulo 2π/θ, where θ is the noncommutative parameter. (In contrast, on a one-dimensional periodic lattice of lattice spacing a and length L = Na, only momentum mod 2π/L is observable (and can be conserved).) Suggestions for further study of this effect are made. Scattering theory is formulated and an approach to quantum field theory is outlined. (author)

Space Station Environmental Control and Life Support System Test Facility at Marshall Space Flight Center

Science.gov (United States)

Springer, Darlene

1989-01-01

Different aspects of Space Station Environmental Control and Life Support System (ECLSS) testing are currently taking place at Marshall Space Flight Center (MSFC). Unique to this testing is the variety of test areas and the fact that all are located in one building. The north high bay of building 4755, the Core Module Integration Facility (CMIF), contains the following test areas: the Subsystem Test Area, the Comparative Test Area, the Process Material Management System (PMMS), the Core Module Simulator (CMS), the End-use Equipment Facility (EEF), and the Pre-development Operational System Test (POST) Area. This paper addresses the facility that supports these test areas and briefly describes the testing in each area. Future plans for the building and Space Station module configurations will also be discussed.

Environmental Studies at the Guiana Space Centre

Science.gov (United States)

Richard, Sandrine

2013-09-01

The Environmental Commitment of the French Space Agency at the Guiana Space Centre (CNES / CSG) specifies that the environmental protection is a major stake. Consequently, CNES participates in numerous space programs that contribute significantly to a better knowledge, management and protection of our environment at a global scale.The studies and researches that are done at CNES / CSG meet several objectives:* Assessment of safety and environmental effects and risk related to the effects overflowing due to a pollution caused by ground and flight activities* Improvement of the studies related to the knowledge of the environment (flora and fauna monitoring).* Risk assessment and management which may affect the safety of people , property, and protection of public health and environment * Verification of the compliance of the results of impact studies of launch vehicle in flight phase provided by the launch operator (Technical Regulation) with the French Safety Operational Acts.In this note, study and research programs are presented. They allow a better knowledge of the surrounding environment and of impacts caused by the industrial activities done in Guiana Space Center.

Contribution to the stochastically studies of space-time dependable hydrological processes

International Nuclear Information System (INIS)

Kjaevski, Ivancho

2002-12-01

One of the fundaments of today's planning and water economy is Science of Hydrology. Science of Hydrology through the history had followed the development of the water management systems. Water management systems, during the time from single-approach evolved to complex and multi purpose systems. The dynamic and development of the today's society contributed for increasing the demand of clean water, and in the same time, the resources of clean water in the nature are reduced. In this kind of conditions, water management systems should resolve problems that are more complicated during managing of water sources. Solving the problems in water management, enable development and applying new methods and technologies in planning and management with water resources and water management systems like: systematical analyses, operational research, hierarchy decisions, expert systems, computer technology etc. Planning and management of water sources needs historical measured data for hydro metrological processes. In our country there are data of hydro metrological processes in period of 50-70, but in some Europe countries there are data more than 100 years. Water economy trends follow the hydro metrological trend research. The basic statistic techniques like sampling, probability distribution function, correlation and regression, are used about one intended and simple water management problems. Solving new problems about water management needs using of space-time stochastic technique, modem mathematical and statistical techniques during simulation and optimization of complex water systems. We need tree phases of development of the techniques to get secure hydrological models: i) Estimate the quality of hydro meteorological data, analyzing of their consistency, and homogeneous; ii) Structural analyze of hydro meteorological processes; iii) Mathematical models for modeling hydro meteorological processes. Very often, the third phase is applied for analyzing and modeling of hydro

Aging in a Relativistic Biological Space-Time

Directory of Open Access Journals (Sweden)

Davide Maestrini

2018-05-01

Full Text Available Here we present a theoretical and mathematical perspective on the process of aging. We extend the concepts of physical space and time to an abstract, mathematically-defined space, which we associate with a concept of “biological space-time” in which biological dynamics may be represented. We hypothesize that biological dynamics, represented as trajectories in biological space-time, may be used to model and study different rates of biological aging. As a consequence of this hypothesis, we show how dilation or contraction of time analogous to relativistic corrections of physical time resulting from accelerated or decelerated biological dynamics may be used to study precipitous or protracted aging. We show specific examples of how these principles may be used to model different rates of aging, with an emphasis on cancer in aging. We discuss how this theory may be tested or falsified, as well as novel concepts and implications of this theory that may improve our interpretation of biological aging.

Overcoming Learning Time And Space Constraints Through Technological Tool

Directory of Open Access Journals (Sweden)

Nafiseh Zarei

2015-08-01

Full Text Available Today the use of technological tools has become an evolution in language learning and language acquisition. Many instructors and lecturers believe that integrating Web-based learning tools into language courses allows pupils to become active learners during learning process. This study investigate how the Learning Management Blog (LMB overcomes the learning time and space constraints that contribute to students’ language learning and language acquisition processes. The participants were 30 ESL students at National University of Malaysia. A qualitative approach comprising an open-ended questionnaire and a semi-structured interview was used to collect data. The results of the study revealed that the students’ language learning and acquisition processes were enhanced. The students did not face any learning time and space limitations while being engaged in the learning process via the LMB. They learned and acquired knowledge using the language learning materials and forum at anytime and anywhere. Keywords: learning time, learning space, learning management blog

Space-time modeling of soil moisture

Science.gov (United States)

Chen, Zijuan; Mohanty, Binayak P.; Rodriguez-Iturbe, Ignacio

2017-11-01

A physically derived space-time mathematical representation of the soil moisture field is carried out via the soil moisture balance equation driven by stochastic rainfall forcing. The model incorporates spatial diffusion and in its original version, it is shown to be unable to reproduce the relative fast decay in the spatial correlation functions observed in empirical data. This decay resulting from variations in local topography as well as in local soil and vegetation conditions is well reproduced via a jitter process acting multiplicatively over the space-time soil moisture field. The jitter is a multiplicative noise acting on the soil moisture dynamics with the objective to deflate its correlation structure at small spatial scales which are not embedded in the probabilistic structure of the rainfall process that drives the dynamics. These scales of order of several meters to several hundred meters are of great importance in ecohydrologic dynamics. Properties of space-time correlation functions and spectral densities of the model with jitter are explored analytically, and the influence of the jitter parameters, reflecting variabilities of soil moisture at different spatial and temporal scales, is investigated. A case study fitting the derived model to a soil moisture dataset is presented in detail.

The science of space-time

International Nuclear Information System (INIS)

Raine, D.J.; Heller, M.

1981-01-01

Analyzing the development of the structure of space-time from the theory of Aristotle to the present day, the present work attempts to sketch a science of relativistic mechanics. The concept of relativity is discussed in relation to the way in which space-time splits up into space and time, and in relation to Mach's principle concerning the relativity of inertia. Particular attention is given to the following topics: Aristotelian dynamics Copernican kinematics Newtonian dynamics the space-time of classical dynamics classical space-time in the presence of gravity the space-time of special relativity the space-time of general relativity solutions and problems in general relativity Mach's principle and the dynamics of space-time theories of inertial mass the integral formation of general relativity and the frontiers of relativity

Rapid evolution in insect pests: the importance of space and time in population genomics studies.

Science.gov (United States)

Pélissié, Benjamin; Crossley, Michael S; Cohen, Zachary Paul; Schoville, Sean D

2018-04-01

Pest species in agroecosystems often exhibit patterns of rapid evolution to environmental and human-imposed selection pressures. Although the role of adaptive processes is well accepted, few insect pests have been studied in detail and most research has focused on selection at insecticide resistance candidate genes. Emerging genomic datasets provide opportunities to detect and quantify selection in insect pest populations, and address long-standing questions about mechanisms underlying rapid evolutionary change. We examine the strengths of recent studies that stratify population samples both in space (along environmental gradients and comparing ancestral vs. derived populations) and in time (using chronological sampling, museum specimens and comparative phylogenomics), resulting in critical insights on evolutionary processes, and providing new directions for studying pests in agroecosystems. Copyright © 2018 Elsevier Inc. All rights reserved.

Military Application of Space-Time Adaptive Processing (Les applications militaires du traitement adaptatif espace-temps)

Science.gov (United States)

2003-04-01

SAR system”, Proc. EUSAR’98, 25-27 May 1998, Friedrichshafen , Ger- many [15] Farina, A., Timmoneri, L., ”Space-time processing for AEW radar”, Proc...98, Friedrichshafen , Germany, 25-27 May 1998. [PSF00] V. Pascazio, G. Schirinzi, A. Farina, “ Along track interferometry by one bit coded SAR signals...airborne multi-channel SAR systems AER II.The air- borne experimental multi-channel SAR system”, Proc. EUSAR’98, 25-27 May 1998, Friedrichshafen , Ger

A bivariate space-time downscaler under space and time misalignment.

Science.gov (United States)

Berrocal, Veronica J; Gelfand, Alan E; Holland, David M

2010-12-01

Ozone and particulate matter PM(2.5) are co-pollutants that have long been associated with increased public health risks. Information on concentration levels for both pollutants come from two sources: monitoring sites and output from complex numerical models that produce concentration surfaces over large spatial regions. In this paper, we offer a fully-model based approach for fusing these two sources of information for the pair of co-pollutants which is computationally feasible over large spatial regions and long periods of time. Due to the association between concentration levels of the two environmental contaminants, it is expected that information regarding one will help to improve prediction of the other. Misalignment is an obvious issue since the monitoring networks for the two contaminants only partly intersect and because the collection rate for PM(2.5) is typically less frequent than that for ozone.Extending previous work in Berrocal et al. (2009), we introduce a bivariate downscaler that provides a flexible class of bivariate space-time assimilation models. We discuss computational issues for model fitting and analyze a dataset for ozone and PM(2.5) for the ozone season during year 2002. We show a modest improvement in predictive performance, not surprising in a setting where we can anticipate only a small gain.

High speed real-time wavefront processing system for a solid-state laser system

Science.gov (United States)

Liu, Yuan; Yang, Ping; Chen, Shanqiu; Ma, Lifang; Xu, Bing

2008-03-01

A high speed real-time wavefront processing system for a solid-state laser beam cleanup system has been built. This system consists of a core2 Industrial PC (IPC) using Linux and real-time Linux (RT-Linux) operation system (OS), a PCI image grabber, a D/A card. More often than not, the phase aberrations of the output beam from solid-state lasers vary fast with intracavity thermal effects and environmental influence. To compensate the phase aberrations of solid-state lasers successfully, a high speed real-time wavefront processing system is presented. Compared to former systems, this system can improve the speed efficiently. In the new system, the acquisition of image data, the output of control voltage data and the implementation of reconstructor control algorithm are treated as real-time tasks in kernel-space, the display of wavefront information and man-machine conversation are treated as non real-time tasks in user-space. The parallel processing of real-time tasks in Symmetric Multi Processors (SMP) mode is the main strategy of improving the speed. In this paper, the performance and efficiency of this wavefront processing system are analyzed. The opened-loop experimental results show that the sampling frequency of this system is up to 3300Hz, and this system can well deal with phase aberrations from solid-state lasers.

Time-Space Topology Optimization

DEFF Research Database (Denmark)

Jensen, Jakob Søndergaard

2008-01-01

A method for space-time topology optimization is outlined. The space-time optimization strategy produces structures with optimized material distributions that vary in space and in time. The method is demonstrated for one-dimensional wave propagation in an elastic bar that has a time-dependent Young......’s modulus and is subjected to a transient load. In the example an optimized dynamic structure is demonstrated that compresses a propagating Gauss pulse....

Discrete random walk models for space-time fractional diffusion

International Nuclear Information System (INIS)

Gorenflo, Rudolf; Mainardi, Francesco; Moretti, Daniele; Pagnini, Gianni; Paradisi, Paolo

2002-01-01

A physical-mathematical approach to anomalous diffusion may be based on generalized diffusion equations (containing derivatives of fractional order in space or/and time) and related random walk models. By space-time fractional diffusion equation we mean an evolution equation obtained from the standard linear diffusion equation by replacing the second-order space derivative with a Riesz-Feller derivative of order α is part of (0,2] and skewness θ (moduleθ≤{α,2-α}), and the first-order time derivative with a Caputo derivative of order β is part of (0,1]. Such evolution equation implies for the flux a fractional Fick's law which accounts for spatial and temporal non-locality. The fundamental solution (for the Cauchy problem) of the fractional diffusion equation can be interpreted as a probability density evolving in time of a peculiar self-similar stochastic process that we view as a generalized diffusion process. By adopting appropriate finite-difference schemes of solution, we generate models of random walk discrete in space and time suitable for simulating random variables whose spatial probability density evolves in time according to this fractional diffusion equation

A discrete-space urban model with environmental amenities

Science.gov (United States)

Liaila Tajibaeva; Robert G. Haight; Stephen Polasky

2008-01-01

This paper analyzes the effects of providing environmental amenities associated with open space in a discrete-space urban model and characterizes optimal provision of open space across a metropolitan area. The discrete-space model assumes distinct neighborhoods in which developable land is homogeneous within a neighborhood but heterogeneous across neighborhoods. Open...

An expert systems application to space base data processing

Science.gov (United States)

Babb, Stephen M.

1988-01-01

The advent of space vehicles with their increased data requirements are reflected in the complexity of future telemetry systems. Space based operations with its immense operating costs will shift the burden of data processing and routine analysis from the space station to the Orbital Transfer Vehicle (OTV). A research and development project is described which addresses the real time onboard data processing tasks associated with a space based vehicle, specifically focusing on an implementation of an expert system.

Systemic determinants of modern gravitational processes in the geo-economic space

Directory of Open Access Journals (Sweden)

Zoryana Lutsyshyn

2015-12-01

Full Text Available From the compositional point of view, research on this topic has revealed two main directions: (1 an analysis of global development asymmetry that has activated gravitational processes in geo-economic space; and (2 a direction that focuses on the profound study of the causes for heterogeneity in geo-economic space and divergence in global development under the influence of gravitational factors of nature on the endogenousexogenous axis. Systemic determinants of gravitational processes are revealed in geo- economic space and the asymmetry of global activate ravitional processes in geo-economic space are observed, and methodological interconnectedness coinfluence of two complementary determinants of global development – convergence and divergence and the contradiction between them are examined, which at the same time underlie the inevitable internal contradictions of the process, creating conditions for further configuration of the «new globalization community», which is built on the principles of nonlinear dynamics and logic gravitational processes in geo-economic space.Taking into account the relevant uncertainties, the attention is focused on the isolation of several myths around which the debate that has important methodological significance in the context of the current global inter-system transformations is held. Geostrategic matrix divergence of global development is produced,which is based on techniques which incorporated cluster analysisthat are built on linguistic variables and integrated analysis of the key trends of country and global development geostrategic position of Ukraine in geo-economic space in the projection on the issues of global inter-system transformations isoutlined .It is proved that the level of gravity load increases in the deepening of the global asymmetries , and that the current global transformation is not yet complete, and polycentric new architecture geospace is not formed. In the near future we should

Study of the space environmental effects on spacecraft engineering materials

Science.gov (United States)

Obrien, Susan K.; Workman, Gary L.; Smith, Guy A.

1995-01-01

The space environment in which the Space Station Freedom and other space platforms will orbit is truly a hostile environment. For example, the current estimates of the integral fluence for electrons above 1 Mev at 2000 nautical miles is above 2 x 10(exp 10) electrons/sq cm/day. and the proton integral fluence is above 1 x 109 protons/sq cm/day. At the 200 - 400 nautical miles, which is more representative of the altitude which will provide the environment for the Space Station, each of these fluences will be proportionately less; however, the data indicates that the radiation environment will obviously have an effect on structural materials exposed to the environment for long durations. The effects of this combined environment is the issue which needs to be understood for the long term exposure of structures in space. In order to better understand the effect of these hostile phenomena on spacecraft, several types of studies are worth performing in order to simulate at some level the effect of the environment. For example the effect of protons and electrons impacting structural materials are easily simulated through experiments using the Van de Graff and Pelletron accelerators currently housed in the Environmental Effects Facility at MSFC. Proton fluxes with energies of 700 Kev-2.5 Mev can be generated and used to impinge on sample targets to determine the effects of the particles. Also the Environmental Effects Facility has the capability to generate electron beams with energies from 700 Kev to 2.5 Mev. These facilities will be used in this research to simulate space environmental effects from energetic particles. Ultraviolet radiation, particularly in the ultraviolet (less than 400 nm wavelength) is less well characterized at this time. The Environmental Effects Facility has a vacuum system dedicated to studying the effects of ultraviolet radiation on specific surface materials. This particular system was assembled in a previous study (NAS8-38609) in order to

Space-time clusters of breast cancer using residential histories

DEFF Research Database (Denmark)

Nordsborg, Rikke Baastrup; Meliker, Jaymie R; Ersbøll, Annette Kjær

2014-01-01

BACKGROUND: A large proportion of breast cancer cases are thought related to environmental factors. Identification of specific geographical areas with high risk (clusters) may give clues to potential environmental risk factors. The aim of this study was to investigate whether clusters of breast...... cancer existed in space and time in Denmark, using 33 years of residential histories. METHODS: We conducted a population-based case-control study of 3138 female cases from the Danish Cancer Registry, diagnosed with breast cancer in 2003 and two independent control groups of 3138 women each, randomly...

Space-Time Quantum Imaging

Directory of Open Access Journals (Sweden)

Ronald E. Meyers

2015-03-01

Full Text Available We report on an experimental and theoretical investigation of quantum imaging where the images are stored in both space and time. Ghost images of remote objects are produced with either one or two beams of chaotic laser light generated by a rotating ground glass and two sensors measuring the reference field and bucket field at different space-time points. We further observe that the ghost images translate depending on the time delay between the sensor measurements. The ghost imaging experiments are performed both with and without turbulence. A discussion of the physics of the space-time imaging is presented in terms of quantum nonlocal two-photon analysis to support the experimental results. The theoretical model includes certain phase factors of the rotating ground glass. These experiments demonstrated a means to investigate the time and space aspects of ghost imaging and showed that ghost imaging contains more information per measured photon than was previously recognized where multiple ghost images are stored within the same ghost imaging data sets. This suggests new pathways to explore quantum information stored not only in multi-photon coincidence information but also in time delayed multi-photon interference. The research is applicable to making enhanced space-time quantum images and videos of moving objects where the images are stored in both space and time.

Conceptualization and measurement of environmental exposure in epidemiology: accounting for activity space related to daily mobility.

Science.gov (United States)

Perchoux, Camille; Chaix, Basile; Cummins, Steven; Kestens, Yan

2013-05-01

A considerable body of literature has investigated how environmental exposures affect health through various pathways. These studies have generally adopted a common approach to define environmental exposures, focusing on the local residential environment, using census tracts or postcodes to delimit exposures. However, use of such administrative units may not be appropriate to evaluate contextual effets on health because they are generally not a 'true' representation of the environments to which individuals are exposed. Recent work has suggested that advances may be made if an activity-space approach is adopted. The present paper investigates how various disciplines may contribute to the refinement of the concept of activity space for use in health research. In particular we draw on seminal work in time geography, which provides a framework to describe individual behavior in space and time, and can help the conceptualization of activity space. In addition we review work in environmental psychology and social networks research, which provides insights on how people and places interact and offers new theories for improving the spatial definition of contextual exposures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Controls on the Environmental Fate of Compounds Controlled by Coupled Hydrologic and Reactive Processes

Science.gov (United States)

Hixson, J.; Ward, A. S.; McConville, M.; Remucal, C.

2017-12-01

Current understanding of how compounds interact with hydrologic processes or reactive processes have been well established. However, the environmental fate for compounds that interact with hydrologic AND reactive processes is not well known, yet critical in evaluating environmental risk. Evaluations of risk are often simplified to homogenize processes in space and time and to assess processes independently of one another. However, we know spatial heterogeneity and time-variable reactivities complicate predictions of environmental transport and fate, and is further complicated by the interaction of these processes, limiting our ability to accurately predict risk. Compounds that interact with both systems, such as photolytic compounds, require that both components are fully understood in order to predict transport and fate. Release of photolytic compounds occurs through both unintentional releases and intentional loadings. Evaluating risks associated with unintentional releases and implementing best management practices for intentional releases requires an in-depth understanding of the sensitivity of photolytic compounds to external controls. Lampricides, such as 3-trifluoromethyl-4-nitrophenol (TFM), are broadly applied in the Great Lakes system to control the population of invasive sea lamprey. Over-dosing can yield fish kills and other detrimental impacts. Still, planning accounts for time of passage and dilution, but not the interaction of the physical and chemical systems (i.e., storage in the hyporheic zone and time-variable decay rates). In this study, we model a series of TFM applications to test the efficacy of dosing as a function of system characteristics. Overall, our results demonstrate the complexity associated with photo-sensitive compounds through stream-hyporheic systems, and highlight the need to better understand how physical and chemical systems interact to control transport and fate in the environment.

Time-space structure of nuclear safety

International Nuclear Information System (INIS)

Miya, Kenzo

2003-01-01

New idea to analyze the structure of nuclear safety and to investigate functioning property of hierarchical principle is applied to nuclear safety in this paper. The nuclear safety is expressed by three principles such as 1) the action and subject are partitioned and classified by time and space, 2) introduction of hierarchy with three strata to the closed object and hierarchy with many strata to the open object and 3) application of 'element, relation and abstraction' to the engineering system as a framework of intellectual activity. For example, prevention of core melt is the closed object and it is obtained by acting hierarchies with three strata (operation stop, cooling and closing radiation) as the safety functions. Prevention of increase of accident is open object, so that, space hierarchy with many strata of prevention is used for the safety security of reactor. The safety security method of reactor consists of three processes, that is 1) the basic process to make clear the continuous operating time on the basis of regular inspection, 2) the action process of operating ECCS to prevent core damage accident, when a large leakage happens and 3) many strata prevention process of stopping a leak in the environment. (S.Y.)

Environmental monitoring and research at the John F. Kennedy Space Center

Science.gov (United States)

Hall, C. R.; Hinkle, C. R.; Knott, W. M.; Summerfield, B. R.

1992-01-01

The Biomedical Operations and Research Office at the NASA John F. Kennedy Space Center has been supporting environmental monitoring and research since the mid-1970s. Program elements include monitoring of baseline conditions to document natural variability in the ecosystem, assessments of operations and construction of new facilities, and ecological research focusing on wildlife habitat associations. Information management is centered around development of a computerized geographic information system that incorporates remote sensing and digital image processing technologies along with traditional relational data base management capabilities. The proactive program is one in which the initiative is to anticipate potential environmental concerns before they occur and, by utilizing in-house expertise, develop impact minimization or mitigation strategies to reduce environmental risk.

Metric space construction for the boundary of space-time

International Nuclear Information System (INIS)

Meyer, D.A.

1986-01-01

A distance function between points in space-time is defined and used to consider the manifold as a topological metric space. The properties of the distance function are investigated: conditions under which the metric and manifold topologies agree, the relationship with the causal structure of the space-time and with the maximum lifetime function of Wald and Yip, and in terms of the space of causal curves. The space-time is then completed as a topological metric space; the resultant boundary is compared with the causal boundary and is also calculated for some pertinent examples

Development of magnitude processing in children with developmental dyscalculia: Space, time and number

Directory of Open Access Journals (Sweden)

Kenny eSkagerlund

2014-06-01

Full Text Available Developmental dyscalculia (DD is a learning disorder associated with impairments in a preverbal non-symbolic approximate number system (ANS pertaining to areas in and around the intraparietal sulcus (IPS. The current study sought to enhance our understanding of the developmental trajectory of the ANS and symbolic number processing skills, thereby getting insight into whether a deficit in the ANS precedes or is preceded by impaired symbolic and exact number processing. Recent work has also suggested that humans are endowed with a shared magnitude system (beyond the number domain in the brain. We therefore investigated whether children with DD demonstrated a general magnitude deficit, stemming from the proposed magnitude system, rather than a specific one limited to numerical quantity. Fourth graders with DD were compared to age-matched controls and a group of ability-matched second graders, on a range of magnitude processing tasks pertaining to space, time, and number. Children with DD displayed difficulties across all magnitude dimensions compared to age-matched peers and showed impaired ANS acuity compared to the younger, ability-matched control group, while exhibiting intact symbolic number processing. We conclude that (1 children with DD suffer from a general magnitude-processing deficit, (2 a shared magnitude system likely exists, and (3 a symbolic number-processing deficit in DD tends to be preceded by an ANS deficit.

Development of magnitude processing in children with developmental dyscalculia: space, time, and number.

Science.gov (United States)

Skagerlund, Kenny; Träff, Ulf

2014-01-01

Developmental dyscalculia (DD) is a learning disorder associated with impairments in a preverbal non-symbolic approximate number system (ANS) pertaining to areas in and around the intraparietal sulcus (IPS). The current study sought to enhance our understanding of the developmental trajectory of the ANS and symbolic number processing skills, thereby getting insight into whether a deficit in the ANS precedes or is preceded by impaired symbolic and exact number processing. Recent work has also suggested that humans are endowed with a shared magnitude system (beyond the number domain) in the brain. We therefore investigated whether children with DD demonstrated a general magnitude deficit, stemming from the proposed magnitude system, rather than a specific one limited to numerical quantity. Fourth graders with DD were compared to age-matched controls and a group of ability-matched second graders, on a range of magnitude processing tasks pertaining to space, time, and number. Children with DD displayed difficulties across all magnitude dimensions compared to age-matched peers and showed impaired ANS acuity compared to the younger, ability-matched control group, while exhibiting intact symbolic number processing. We conclude that (1) children with DD suffer from a general magnitude-processing deficit, (2) a shared magnitude system likely exists, and (3) a symbolic number-processing deficit in DD tends to be preceded by an ANS deficit.

Solar Array Sails: Possible Space Plasma Environmental Effects

Science.gov (United States)

Mackey, Willie R.

2005-01-01

An examination of the interactions between proposed "solar sail" propulsion systems with photovoltaic energy generation capabilities and the space plasma environments. Major areas of interactions ere: Acting from high voltage arrays, ram and wake effects, V and B current loops and EMI. Preliminary analysis indicates that arcing will be a major risk factor for voltages greater than 300V. Electron temperature enhancement in the wake will be produce noise that can be transmitted via the wake echo process. In addition, V and B induced potential will generate sheath voltages with potential tether like breakage effects in the thin film sails. Advocacy of further attention to these processes is emphasized so that plasma environmental mitigation will be instituted in photovoltaic sail design.

Exploration Space Suit Architecture: Destination Environmental-Based Technology Development

Science.gov (United States)

Hill, Terry R.

2010-01-01

This paper picks up where EVA Space Suit Architecture: Low Earth Orbit Vs. Moon Vs. Mars (Hill, Johnson, IEEEAC paper #1209) left off in the development of a space suit architecture that is modular in design and interfaces and could be reconfigured to meet the mission or during any given mission depending on the tasks or destination. This paper will walk though the continued development of a space suit system architecture, and how it should evolve to meeting the future exploration EVA needs of the United States space program. In looking forward to future US space exploration and determining how the work performed to date in the CxP and how this would map to a future space suit architecture with maximum re-use of technology and functionality, a series of thought exercises and analysis have provided a strong indication that the CxP space suit architecture is well postured to provide a viable solution for future exploration missions. Through the destination environmental analysis that is presented in this paper, the modular architecture approach provides the lowest mass, lowest mission cost for the protection of the crew given any human mission outside of low Earth orbit. Some of the studies presented here provide a look and validation of the non-environmental design drivers that will become every-increasingly important the further away from Earth humans venture and the longer they are away. Additionally, the analysis demonstrates a logical clustering of design environments that allows a very focused approach to technology prioritization, development and design that will maximize the return on investment independent of any particular program and provide architecture and design solutions for space suit systems in time or ahead of being required for any particular manned flight program in the future. The new approach to space suit design and interface definition the discussion will show how the architecture is very adaptable to programmatic and funding changes with

The Thaayorre think of Time Like They Talk of Space.

Science.gov (United States)

Gaby, Alice

2012-01-01

Around the world, it is common to both talk and think about time in terms of space. But does our conceptualization of time simply reflect the space/time metaphors of the language we speak? Evidence from the Australian language Kuuk Thaayorre suggests not. Kuuk Thaayorre speakers do not employ active spatial metaphors in describing time. But this is not to say that spatial language is irrelevant to temporal construals: non-linguistic representations of time are shown here to covary with the linguistic system of describing space. This article contrasts two populations of ethnic Thaayorre from Pormpuraaw - one comprising Kuuk Thaayorre/English bilinguals and the other English-monolinguals - in order to distinguish the effects of language from environmental and other factors. Despite their common physical, social, and cultural context, the two groups differ in their representations of time in ways that are congruent with the language of space in Kuuk Thaayorre and English, respectively. Kuuk Thaayorre/English bilinguals represent time along an absolute east-to-west axis, in alignment with the high frequency of absolute frame of reference terms in Kuuk Thaayorre spatial description. The English-monolinguals, in contrast, represent time from left-to-right, aligning with the dominant relative frame of reference in English spatial description. This occurs in the absence of any east-to-west metaphors in Kuuk Thaayorre, or left-to-right metaphors in English. Thus the way these two groups think about time appears to reflect the language of space and not the language of time.

Ecological processes for Environmental Impact Assessment in Coastal Waters; Engan no kankyo eikyo hyoka (EIA) eno seitaigakuteki apurochi

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, Kimitoshi. [Environmental Assessment Dept., Tokyo (Japan)

1999-03-25

This paper focuses on a method for estimating adverse effects on natural environment by economic development in coastal waters in Japan. In particular, the most critical relations concerning the impact on marine organisms is pointed out and discussed according to an environmental impact assessment. Relations between environmental impact assessment and marine organisms needs a quantitative ecological approach in order to succeed in sustainable development of coastal waters management. Recently, the Environment Agency of Japan pointed out the unreliability and the theme on accuracy and the staff for biology and ecology in the environmental impact study. Ecological response to environmental impact occurs in a wide spectrum of physiological and biological and biological functions. Therefore biological monitoring measures must correspond to the given time-space scale of natural mechanisms. For the evaluation of environmental impact, it is desire able to develop of experimental technics and collect biological and ecological basic data for the object. I Reconstructing the following: 1. Reconstructing a clearlistic EIA process by EIA agencies and practitioners, 2. Scorping the biological and ecological issues by EIA professionals, 3. Using the current computer technology, 4. Considering monitoring systems over scales of time and space for the ecological target and 5. Making available to public all monitoring data and reports of EIA. (author)

Time-Space Trade-Offs

DEFF Research Database (Denmark)

Pagter, Jakob Illeborg

. The area of time-space trade-offs deals with both upper and lower bounds and both are interesting, theoretically as well as practically. The viewpoint of this dissertation is theoretical, but we believe that some of our results can find applications in practice as well. The last four years has witnessed...... perspective hierarchical memory layout models are the most interesting. Such models are called external memory models, in contrast to the internal memory models discussed above. Despite the fact that space might be of great relevance when solving practical problems on real computers, no theoretical model...... capturing space (and time simultaneously) has been defined. We introduce such a model and use it to prove so-called IOspace trade-offs for Sorting. Building on the abovementioned techniques for time-space efficient internal memory Sorting, we develop the first IO-space efficient external memory Sorting...

Coding space-time stimulus dynamics in auditory brain maps

Directory of Open Access Journals (Sweden)

Yunyan eWang

2014-04-01

Full Text Available Sensory maps are often distorted representations of the environment, where ethologically-important ranges are magnified. The implication of a biased representation extends beyond increased acuity for having more neurons dedicated to a certain range. Because neurons are functionally interconnected, non-uniform representations influence the processing of high-order features that rely on comparison across areas of the map. Among these features are time-dependent changes of the auditory scene generated by moving objects. How sensory representation affects high order processing can be approached in the map of auditory space of the owl’s midbrain, where locations in the front are over-represented. In this map, neurons are selective not only to location but also to location over time. The tuning to space over time leads to direction selectivity, which is also topographically organized. Across the population, neurons tuned to peripheral space are more selective to sounds moving into the front. The distribution of direction selectivity can be explained by spatial and temporal integration on the non-uniform map of space. Thus, the representation of space can induce biased computation of a second-order stimulus feature. This phenomenon is likely observed in other sensory maps and may be relevant for behavior.

Brain system for mental orientation in space, time, and person.

Science.gov (United States)

Peer, Michael; Salomon, Roy; Goldberg, Ilan; Blanke, Olaf; Arzy, Shahar

2015-09-01

Orientation is a fundamental mental function that processes the relations between the behaving self to space (places), time (events), and person (people). Behavioral and neuroimaging studies have hinted at interrelations between processing of these three domains. To unravel the neurocognitive basis of orientation, we used high-resolution 7T functional MRI as 16 subjects compared their subjective distance to different places, events, or people. Analysis at the individual-subject level revealed cortical activation related to orientation in space, time, and person in a precisely localized set of structures in the precuneus, inferior parietal, and medial frontal cortex. Comparison of orientation domains revealed a consistent order of cortical activity inside the precuneus and inferior parietal lobes, with space orientation activating posterior regions, followed anteriorly by person and then time. Core regions at the precuneus and inferior parietal lobe were activated for multiple orientation domains, suggesting also common processing for orientation across domains. The medial prefrontal cortex showed a posterior activation for time and anterior for person. Finally, the default-mode network, identified in a separate resting-state scan, was active for all orientation domains and overlapped mostly with person-orientation regions. These findings suggest that mental orientation in space, time, and person is managed by a specific brain system with a highly ordered internal organization, closely related to the default-mode network.

Detecting space-time cancer clusters using residential histories

Science.gov (United States)

Jacquez, Geoffrey M.; Meliker, Jaymie R.

2007-04-01

Methods for analyzing geographic clusters of disease typically ignore the space-time variability inherent in epidemiologic datasets, do not adequately account for known risk factors (e.g., smoking and education) or covariates (e.g., age, gender, and race), and do not permit investigation of the latency window between exposure and disease. Our research group recently developed Q-statistics for evaluating space-time clustering in cancer case-control studies with residential histories. This technique relies on time-dependent nearest neighbor relationships to examine clustering at any moment in the life-course of the residential histories of cases relative to that of controls. In addition, in place of the widely used null hypothesis of spatial randomness, each individual's probability of being a case is instead based on his/her risk factors and covariates. Case-control clusters will be presented using residential histories of 220 bladder cancer cases and 440 controls in Michigan. In preliminary analyses of this dataset, smoking, age, gender, race and education were sufficient to explain the majority of the clustering of residential histories of the cases. Clusters of unexplained risk, however, were identified surrounding the business address histories of 10 industries that emit known or suspected bladder cancer carcinogens. The clustering of 5 of these industries began in the 1970's and persisted through the 1990's. This systematic approach for evaluating space-time clustering has the potential to generate novel hypotheses about environmental risk factors. These methods may be extended to detect differences in space-time patterns of any two groups of people, making them valuable for security intelligence and surveillance operations.

Space Situational Awareness Data Processing Scalability Utilizing Google Cloud Services

Science.gov (United States)

Greenly, D.; Duncan, M.; Wysack, J.; Flores, F.

Space Situational Awareness (SSA) is a fundamental and critical component of current space operations. The term SSA encompasses the awareness, understanding and predictability of all objects in space. As the population of orbital space objects and debris increases, the number of collision avoidance maneuvers grows and prompts the need for accurate and timely process measures. The SSA mission continually evolves to near real-time assessment and analysis demanding the need for higher processing capabilities. By conventional methods, meeting these demands requires the integration of new hardware to keep pace with the growing complexity of maneuver planning algorithms. SpaceNav has implemented a highly scalable architecture that will track satellites and debris by utilizing powerful virtual machines on the Google Cloud Platform. SpaceNav algorithms for processing CDMs outpace conventional means. A robust processing environment for tracking data, collision avoidance maneuvers and various other aspects of SSA can be created and deleted on demand. Migrating SpaceNav tools and algorithms into the Google Cloud Platform will be discussed and the trials and tribulations involved. Information will be shared on how and why certain cloud products were used as well as integration techniques that were implemented. Key items to be presented are: 1.Scientific algorithms and SpaceNav tools integrated into a scalable architecture a) Maneuver Planning b) Parallel Processing c) Monte Carlo Simulations d) Optimization Algorithms e) SW Application Development/Integration into the Google Cloud Platform 2. Compute Engine Processing a) Application Engine Automated Processing b) Performance testing and Performance Scalability c) Cloud MySQL databases and Database Scalability d) Cloud Data Storage e) Redundancy and Availability

Gauge Gravity and Space-Time

OpenAIRE

Wu, Ning

2012-01-01

When we discuss problems on gravity, we can not avoid some fundamental physical problems, such as space-time, inertia, and inertial reference frame. The goal of this paper is to discuss the logic system of gravity theory and the problems of space-time, inertia, and inertial reference frame. The goal of this paper is to set up the theory on space-time in gauge theory of gravity. Based on this theory, it is possible for human kind to manipulate physical space-time on earth, and produce a machin...

Second order evolution inclusions governed by sweeping process in Banach spaces

Directory of Open Access Journals (Sweden)

A. G. Ibrahim

2009-11-01

Full Text Available In this paper we prove two existence theorems concerning the existence of solutions for second order evolution inclusions governed by sweeping process with closed convex sets depending on time and state in Banach spaces. This work extends some recent existence theorems cncerning sweeping process from Hilbert spaces to Banach spaces.

A stochastic space-time model for intermittent precipitation occurrences

KAUST Repository

Sun, Ying; Stein, Michael L.

2016-01-01

Modeling a precipitation field is challenging due to its intermittent and highly scale-dependent nature. Motivated by the features of high-frequency precipitation data from a network of rain gauges, we propose a threshold space-time t random field (tRF) model for 15-minute precipitation occurrences. This model is constructed through a space-time Gaussian random field (GRF) with random scaling varying along time or space and time. It can be viewed as a generalization of the purely spatial tRF, and has a hierarchical representation that allows for Bayesian interpretation. Developing appropriate tools for evaluating precipitation models is a crucial part of the model-building process, and we focus on evaluating whether models can produce the observed conditional dry and rain probabilities given that some set of neighboring sites all have rain or all have no rain. These conditional probabilities show that the proposed space-time model has noticeable improvements in some characteristics of joint rainfall occurrences for the data we have considered.

A stochastic space-time model for intermittent precipitation occurrences

KAUST Repository

Sun, Ying

2016-01-28

Modeling a precipitation field is challenging due to its intermittent and highly scale-dependent nature. Motivated by the features of high-frequency precipitation data from a network of rain gauges, we propose a threshold space-time t random field (tRF) model for 15-minute precipitation occurrences. This model is constructed through a space-time Gaussian random field (GRF) with random scaling varying along time or space and time. It can be viewed as a generalization of the purely spatial tRF, and has a hierarchical representation that allows for Bayesian interpretation. Developing appropriate tools for evaluating precipitation models is a crucial part of the model-building process, and we focus on evaluating whether models can produce the observed conditional dry and rain probabilities given that some set of neighboring sites all have rain or all have no rain. These conditional probabilities show that the proposed space-time model has noticeable improvements in some characteristics of joint rainfall occurrences for the data we have considered.

Green hypocrisy? Environmental attitudes and residential space heating expenditure

Energy Technology Data Exchange (ETDEWEB)

Traynor, Laura; Lange, Ian; Moro, Mirko [Stirling Univ. (United Kingdom). Division of Economics

2012-06-15

In the UK, the largest proportion of household energy use is for space heating. Popular media make claims of a green hypocrisy: groups which have the strongest attitude towards the environment have the highest emissions. This study examines whether environmental attitudes and behaviours are associated with space heating energy use using data from the British Household Panel Survey. Results find that environmentally friendly attitudes generally do not lead to lower heating expenditures though environmentally friendly behaviours are associated with lower heating expenditure. Also, the effect of these attitudes and behaviours do not change as income increase.

Space-Time Chip Equalization for Maximum Diversity Space-Time Block Coded DS-CDMA Downlink Transmission

Directory of Open Access Journals (Sweden)

Petré Frederik

2004-01-01

Full Text Available In the downlink of DS-CDMA, frequency-selectivity destroys the orthogonality of the user signals and introduces multiuser interference (MUI. Space-time chip equalization is an efficient tool to restore the orthogonality of the user signals and suppress the MUI. Furthermore, multiple-input multiple-output (MIMO communication techniques can result in a significant increase in capacity. This paper focuses on space-time block coding (STBC techniques, and aims at combining STBC techniques with the original single-antenna DS-CDMA downlink scheme. This results into the so-called space-time block coded DS-CDMA downlink schemes, many of which have been presented in the past. We focus on a new scheme that enables both the maximum multiantenna diversity and the maximum multipath diversity. Although this maximum diversity can only be collected by maximum likelihood (ML detection, we pursue suboptimal detection by means of space-time chip equalization, which lowers the computational complexity significantly. To design the space-time chip equalizers, we also propose efficient pilot-based methods. Simulation results show improved performance over the space-time RAKE receiver for the space-time block coded DS-CDMA downlink schemes that have been proposed for the UMTS and IS-2000 W-CDMA standards.

An Automatic Framework Using Space-Time Processing and TR-MUSIC for Subsurface and Through-Wall Multitarget Imaging

Directory of Open Access Journals (Sweden)

Si-hao Tan

2012-01-01

Full Text Available We present an automatic framework combined space-time signal processing with Time Reversal electromagnetic (EM inversion for subsurface and through-wall multitarget imaging using electromagnetic waves. This framework is composed of a frequency-wavenumber (FK filter to suppress direct wave and medium bounce, a FK migration algorithm to automatically estimate the number of targets and identify target regions, which can be used to reduce the computational complexity of the following imaging algorithm, and a EM inversion algorithm using Time Reversal Multiple Signal Classification (TR-MUSIC to reconstruct hidden objects. The feasibility of the framework is demonstrated with simulated data generated by GPRMAX.

Space and time, matter and mind the relationship between reality and space-time

CERN Document Server

1994-01-01

In principle, the elements of space and time cannot be measured. Therefore, the following question arises: How are reality and space-time related to each other? In this book, it is argued on the basis of many facts that reality is not embedded but projected onto space and time. We can never make statements about the actual reality outside (basic reality), but we can "only" form pictures of it. These are pictures of the same reality on different levels. From this point of view, the "hard" objects (matter) and the products of the mind are similar in character.

Green hypocrisy? Environmental attitudes and residential space heating expenditure

OpenAIRE

Traynor, Laura; Lange, Ian A.; Moro, Mirko

2012-01-01

In the UK, the largest proportion of household energy use is for space heating. Popular media make claims of a green hypocrisy: groups which have the strongest attitude towards the environment have the highest emissions. This study examines whether environmental attitudes and behaviours are associated with space heating energy use using data from the British Household Panel Survey. Results find that environmentally friendly attitudes generally do not lead to lower heating expenditures though ...

Space Station Environmental Control/Life Support System engineering

Science.gov (United States)

Miller, C. W.; Heppner, D. B.

1985-01-01

The present paper is concerned with a systems engineering study which has provided an understanding of the overall Space Station ECLSS (Environmental Control and Life Support System). ECLSS/functional partitioning is considered along with function criticality, technology alternatives, a technology description, single thread systems, Space Station architectures, ECLSS distribution, mechanical schematics per space station, and Space Station ECLSS characteristics. Attention is given to trade studies and system synergism. The Space Station functional description had been defined by NASA. The ECLSS will utilize technologies which embody regenerative concepts to minimize the use of expendables.

Space for action: How practitioners influence environmental assessment

Energy Technology Data Exchange (ETDEWEB)

Kågström, Mari, E-mail: mari.kagstrom@slu.se [Department of Urban and Rural Development, Swedish University of Agricultural Sciences (Sweden); Richardson, Tim, E-mail: tim.richardson@nmbu.no [Department of Landscape Architecture and Spatial Planning, Norwegian University of Life Sciences, Frederik A Dahls vei 15, KA-bygningen, Ås (Norway)

2015-09-15

Highlights: • The concept of ‘space for action’ offers an important new lens on EA practice. • Focuses on the relation between practitioner's understanding and their actions • Environmental assessment practice is decisively shaped by practitioners. • Practitioners may underestimate their potential to make a difference. • Contributes to understanding change in the environmental assessment field. This article contributes to understanding of how change occurs in the field of environmental assessment (EA). It argues that the integration of new issues in EA, such as human health, is significantly influenced by how practitioners' understandings shape their actions, and by what happens when those, possibly different, interpretations of appropriate action are acted out. The concept of space for action is developed as a means of investigating this relation between understanding and action. Frame theory is also used, to develop a sharper focus on how ‘potential spaces for action’ are created, what these imply for (individuals') preferred choices and actions in certain situations, and what happens in practice when these are acted out and ‘actual spaces for action’ are created. This novel approach is then applied in a Swedish case study of transport planning. The analysis reveals the important work done by practitioners, revealing just how EA practice is decisively shaped by practitioners. Analysis of practice using the lens of spaces for action offers an important new perspective in understanding how the field adapts to new challenges.

Space for action: How practitioners influence environmental assessment

International Nuclear Information System (INIS)

Kågström, Mari; Richardson, Tim

2015-01-01

Highlights: • The concept of ‘space for action’ offers an important new lens on EA practice. • Focuses on the relation between practitioner's understanding and their actions • Environmental assessment practice is decisively shaped by practitioners. • Practitioners may underestimate their potential to make a difference. • Contributes to understanding change in the environmental assessment field. This article contributes to understanding of how change occurs in the field of environmental assessment (EA). It argues that the integration of new issues in EA, such as human health, is significantly influenced by how practitioners' understandings shape their actions, and by what happens when those, possibly different, interpretations of appropriate action are acted out. The concept of space for action is developed as a means of investigating this relation between understanding and action. Frame theory is also used, to develop a sharper focus on how ‘potential spaces for action’ are created, what these imply for (individuals') preferred choices and actions in certain situations, and what happens in practice when these are acted out and ‘actual spaces for action’ are created. This novel approach is then applied in a Swedish case study of transport planning. The analysis reveals the important work done by practitioners, revealing just how EA practice is decisively shaped by practitioners. Analysis of practice using the lens of spaces for action offers an important new perspective in understanding how the field adapts to new challenges

Space, time and conservation laws

International Nuclear Information System (INIS)

Aronov, R.A.; Ugarov, V.A.

1978-01-01

The Neter theorem establishing correspondence between conservation laws and symmetry properties (space and time in particular) is considered. The theorem is based on one of the possible ways of finding equations of motion for a physical system. From a certain expression (action functional) equations of motion for a system can be obtained which do not contain new physical assertions in principal in comparison with the Newtonian laws. Neter suggested a way of deriving conservation laws by transforming space and time coordinates. Neter theorem consequences raise a number of problems: 1). Are conservation laws (energy, momentum) consequences of space and time symmetry properties. 2). Is it possible to obtain conservation laws in theory neglecting equations of motion. 3). What is of the primary importance: equations of motion, conservation laws or properties of space and time symmetry. It is shown that direct Neter theorem does not testify to stipulation of conservation laws by properties of space and time symmetry and symmetry properties of other non-space -time properties of material systems in objective reality. It says nothing of whether there is any subordination between symmetry properties and conservation laws

Research Progress of Space-Time Adaptive Detection for Airborne Radar

Directory of Open Access Journals (Sweden)

Wang Yong-liang

2014-04-01

Full Text Available Compared with Space-Time Adaptive Processing (STAP, Space-Time Adaptive Detection (STAD employs the data in the cell under test and those in the training to form reasonable detection statistics and consequently decides whether the target exists or not. The STAD has concise processing procedure and flexible design. Furthermore, the detection statistics usually possess the Constant False Alarm Rate (CFAR property, and hence it needs no additional CFAR processing. More importantly, the STAD usually exhibits improved detection performance than that of the conventional processing, which first suppresses the clutter then adopts other detection strategy. In this paper, we first summarize the key strongpoint of the STAD, then make a classification for the STAD, and finally give some future research tracks.

Land use and land cover change based on historical space-time model

Science.gov (United States)

Sun, Qiong; Zhang, Chi; Liu, Min; Zhang, Yongjing

2016-09-01

Land use and cover change is a leading edge topic in the current research field of global environmental changes and case study of typical areas is an important approach understanding global environmental changes. Taking the Qiantang River (Zhejiang, China) as an example, this study explores automatic classification of land use using remote sensing technology and analyzes historical space-time change by remote sensing monitoring. This study combines spectral angle mapping (SAM) with multi-source information and creates a convenient and efficient high-precision land use computer automatic classification method which meets the application requirements and is suitable for complex landform of the studied area. This work analyzes the histological space-time characteristics of land use and cover change in the Qiantang River basin in 2001, 2007 and 2014, in order to (i) verify the feasibility of studying land use change with remote sensing technology, (ii) accurately understand the change of land use and cover as well as historical space-time evolution trend, (iii) provide a realistic basis for the sustainable development of the Qiantang River basin and (iv) provide a strong information support and new research method for optimizing the Qiantang River land use structure and achieving optimal allocation of land resources and scientific management.

Process benchmarking for improvement of environmental restoration activities

International Nuclear Information System (INIS)

Celorie, J.A.; Selman, J.R.; Larson, N.B.

1995-01-01

A process benchmarking study was initiated by the Office of Environmental Management (EM) of the US Department of Energy (DOE) to analyze and improve the department's environmental assessment and environmental restoration (ER) processes. The purpose of this study was to identify specific differences in the processes and implementation procedures used at comparable remediation sites to determine best practices which had the greatest potential to minimize the cost and time required to conduct remedial investigation/ feasibility study (RI/FS) activities. Technical criteria were identified and used to select four DOE, two Department of Defense (DOD), and two Environmental Protection Agency (EPA) restoration sites that exhibited comparable characteristics and regulatory environments. By comparing the process elements and activities executed at the different sites for similar endpoints, best practices were identified for streamlining process elements and minimizing non-value-added activities. Critical measures that influenced process performance were identified and characterized for the sites. This benchmarking study focused on two processes and the internal/external review of documents and the development of the initial evaluation and data collection plan (IEDCP)--since these had a great potential for savings, a high impact on other processes, and a high probability for implementation

Kolmogorov Space in Time Series Data

OpenAIRE

Kanjamapornkul, K.; Pinčák, R.

2016-01-01

We provide the proof that the space of time series data is a Kolmogorov space with $T_{0}$-separation axiom using the loop space of time series data. In our approach we define a cyclic coordinate of intrinsic time scale of time series data after empirical mode decomposition. A spinor field of time series data comes from the rotation of data around price and time axis by defining a new extradimension to time series data. We show that there exist hidden eight dimensions in Kolmogorov space for ...

Ground Processing Affordability for Space Vehicles

Science.gov (United States)

Ingalls, John; Scott, Russell

2011-01-01

Launch vehicles and most of their payloads spend the majority of their time on the ground. The cost of ground operations is very high. So, why so often is so little attention given to ground processing during development? The current global space industry and economic environment are driving more need for efficiencies to save time and money. Affordability and sustainability are more important now than ever. We can not continue to treat space vehicles as mere science projects. More RLV's (Reusable Launch Vehicles) are being developed for the gains of reusability which are not available for ELV's (Expendable Launch Vehicles). More human-rated vehicles are being developed, with the retirement of the Space Shuttles, and for a new global space race, yet these cost more than the many unmanned vehicles of today. We can learn many lessons on affordability from RLV's. DFO (Design for Operations) considers ground operations during design, development, and manufacturing-before the first flight. This is often minimized for space vehicles, but is very important. Vehicles are designed for launch and mission operations. You will not be able to do it again if it is too slow or costly to get there. Many times, technology changes faster than space products such that what is launched includes outdated features, thus reducing competitiveness. Ground operations must be considered for the full product Lifecycle, from concept to retirement. Once manufactured, launch vehicles along with their payloads and launch systems require a long path of processing before launch. Initial assembly and testing always discover problems to address. A solid integration program is essential to minimize these impacts, as was seen in the Constellation Ares I-X test rocket. For RLV's, landing/recovery and post-flight turnaround activities are performed. Multi-use vehicles require reconfiguration. MRO (Maintenance, Repair, and Overhaul) must be well-planned--- even for the unplanned problems. Defect limits and

Maximum Likelihood Blind Channel Estimation for Space-Time Coding Systems

Directory of Open Access Journals (Sweden)

Hakan A. Çırpan

2002-05-01

Full Text Available Sophisticated signal processing techniques have to be developed for capacity enhancement of future wireless communication systems. In recent years, space-time coding is proposed to provide significant capacity gains over the traditional communication systems in fading wireless channels. Space-time codes are obtained by combining channel coding, modulation, transmit diversity, and optional receive diversity in order to provide diversity at the receiver and coding gain without sacrificing the bandwidth. In this paper, we consider the problem of blind estimation of space-time coded signals along with the channel parameters. Both conditional and unconditional maximum likelihood approaches are developed and iterative solutions are proposed. The conditional maximum likelihood algorithm is based on iterative least squares with projection whereas the unconditional maximum likelihood approach is developed by means of finite state Markov process modelling. The performance analysis issues of the proposed methods are studied. Finally, some simulation results are presented.

Time: the enigma of space

Science.gov (United States)

Yu, Francis T. S.

2017-08-01

In this article we have based on the laws of physics to illustrate the enigma time as creating our physical space (i.e., the universe). We have shown that without time there would be no physical substances, no space and no life. In reference to Einstein's energy equation, we see that energy and mass can be traded, and every mass can be treated as an Energy Reservoir. We have further shown that physical space cannot be embedded in absolute empty space and cannot have any absolute empty subspace in it. Since all physical substances existed with time, our cosmos is created by time and every substance including our universe is coexisted with time. Although time initiates the creation, it is the physical substances which presented to us the existence of time. We are not alone with almost absolute certainty. Someday we may find a right planet, once upon a time, had harbored a civilization for a short period of light years.

Environmental Aspects, Objectives and Targets Identification Process

International Nuclear Information System (INIS)

Green, R.

2002-01-01

The purpose of this report is to document the environmental aspects and associated environmental impacts of the Bechtel SAIC Company (BSC) scope of work, evaluate the significance of those environmental aspects based on established criteria, and establish environmental objectives and targets for specific environmental aspects. This report is intended to be used by environmental staff in the evaluation of BSC work packages during the annual risk-based planning process. This report shall be fully reviewed and revised annually during the annual work planning process to reflect changes in BSC operations, facilities, and scope of work. Planned BSC work will be evaluated to determine if the work is covered by a previously defined activity, product or service (see Table 2); if work activities require redefinition or addition of a new activity; and if the significant evaluation for each environment aspect is still valid based on scope of planned work. New workscope initiated during the fiscal year through the Baseline Change Proposal process (i.e., not as part of the annual work plan) also will be reviewed for new environmental aspects and determination of whether the new workscope would change the significance rating of any environmental aspect. If a new environmental aspect is identified in a new work activity, product, or service but the aspect is not determined to be significant (see Section 4), then this report can be changed through an interim change notice (ICN). This report can be changed five times through an ICN before a full revision is required. However, if new workscope causes an environmental aspect to be graded as significant using the evaluation process in Section 4, this report shall be revised though a full review and revision

Environmental review process: The U.S. experience

International Nuclear Information System (INIS)

Russo, T.N.

1993-01-01

The environmental review process used by the United States Federal Energy Regulatory Commission was discussed. The process has enabled the Commission to assess proposed small hydropower projects, but in the view of the author the Commission has done so at considerable cost and time to developers. Principal reasons for the delays and additional costs were examined, and ways were suggested that developers, agencies, regulators and other stakeholders could facilitate the siting of small hydropower projects without sacrificing the quality of the environmental review process. The highly duplicative nature of the environmental review process for hydropower projects was highlighted. The Commissions's power to regulate hydropower was claimed to have become severely eroded and the Energy Policy Act of 1992 did not significantly improve the process. Conflicts between developers, federal and state agencies, and the Commission over jurisdiction and interpretation of statutes continue to cause siting delays, which could render many projects financially infeasible. A more proactive Federal Energy Regulatory Commission was suggested to work with developers, agencies, Indian tribes and non-government organizations to resolve disputes. 1 tab

Space Weather and Real-Time Monitoring

Directory of Open Access Journals (Sweden)

S Watari

2009-04-01

Full Text Available Recent advance of information and communications technology enables to collect a large amount of ground-based and space-based observation data in real-time. The real-time data realize nowcast of space weather. This paper reports a history of space weather by the International Space Environment Service (ISES in association with the International Geophysical Year (IGY and importance of real-time monitoring in space weather.

Twistor Cosmology and Quantum Space-Time

International Nuclear Information System (INIS)

Brody, D.C.; Hughston, L.P.

2005-01-01

The purpose of this paper is to present a model of a 'quantum space-time' in which the global symmetries of space-time are unified in a coherent manner with the internal symmetries associated with the state space of quantum-mechanics. If we take into account the fact that these distinct families of symmetries should in some sense merge and become essentially indistinguishable in the unified regime, our framework may provide an approximate description of or elementary model for the structure of the universe at early times. The quantum elements employed in our characterisation of the geometry of space-time imply that the pseudo-Riemannian structure commonly regarded as an essential feature in relativistic theories must be dispensed with. Nevertheless, the causal structure and the physical kinematics of quantum space-time are shown to persist in a manner that remains highly analogous to the corresponding features of the classical theory. In the case of the simplest conformally flat cosmological models arising in this framework, the twistorial description of quantum space-time is shown to be effective in characterising the various physical and geometrical properties of the theory. As an example, a sixteen-dimensional analogue of the Friedmann-Robertson-Walker cosmologies is constructed, and its chronological development is analysed in some detail. More generally, whenever the dimension of a quantum space-time is an even perfect square, there exists a canonical way of breaking the global quantum space-time symmetry so that a generic point of quantum space-time can be consistently interpreted as a quantum operator taking values in Minkowski space. In this scenario, the breakdown of the fundamental symmetry of the theory is due to a loss of quantum entanglement between space-time and internal quantum degrees of freedom. It is thus possible to show in a certain specific sense that the classical space-time description is an emergent feature arising as a consequence of a

Environmental assessment for radioisotope heat source fuel processing and fabrication

International Nuclear Information System (INIS)

1991-07-01

DOE has prepared an Environmental Assessment (EA) for radioisotope heat source fuel processing and fabrication involving existing facilities at the Savannah River Site (SRS) near Aiken, South Carolina and the Los Alamos National Laboratory (LANL) near Los Alamos, New Mexico. The proposed action is needed to provide Radioisotope Thermoelectric Generators (RTG) to support the National Aeronautics and Space Administration's (NASA) CRAF and Cassini Missions. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement is not required. 30 refs., 5 figs

Hyperbolic statics in space-time

OpenAIRE

Pavlov, Dmitry; Kokarev, Sergey

2014-01-01

Based on the concept of material event as an elementary material source that is concentrated on metric sphere of zero radius --- light-cone of Minkowski space-time, we deduce the analog of Coulomb's law for hyperbolic space-time field universally acting between the events of space-time. Collective field that enables interaction of world lines of a pair of particles at rest contains a standard 3-dimensional Coulomb's part and logarithmic addendum. We've found that the Coulomb's part depends on...

pySPACE-a signal processing and classification environment in Python.

Science.gov (United States)

Krell, Mario M; Straube, Sirko; Seeland, Anett; Wöhrle, Hendrik; Teiwes, Johannes; Metzen, Jan H; Kirchner, Elsa A; Kirchner, Frank

2013-01-01

In neuroscience large amounts of data are recorded to provide insights into cerebral information processing and function. The successful extraction of the relevant signals becomes more and more challenging due to increasing complexities in acquisition techniques and questions addressed. Here, automated signal processing and machine learning tools can help to process the data, e.g., to separate signal and noise. With the presented software pySPACE (http://pyspace.github.io/pyspace), signal processing algorithms can be compared and applied automatically on time series data, either with the aim of finding a suitable preprocessing, or of training supervised algorithms to classify the data. pySPACE originally has been built to process multi-sensor windowed time series data, like event-related potentials from the electroencephalogram (EEG). The software provides automated data handling, distributed processing, modular build-up of signal processing chains and tools for visualization and performance evaluation. Included in the software are various algorithms like temporal and spatial filters, feature generation and selection, classification algorithms, and evaluation schemes. Further, interfaces to other signal processing tools are provided and, since pySPACE is a modular framework, it can be extended with new algorithms according to individual needs. In the presented work, the structural hierarchies are described. It is illustrated how users and developers can interface the software and execute offline and online modes. Configuration of pySPACE is realized with the YAML format, so that programming skills are not mandatory for usage. The concept of pySPACE is to have one comprehensive tool that can be used to perform complete signal processing and classification tasks. It further allows to define own algorithms, or to integrate and use already existing libraries.

A geometric renormalization group in discrete quantum space-time

International Nuclear Information System (INIS)

Requardt, Manfred

2003-01-01

We model quantum space-time on the Planck scale as dynamical networks of elementary relations or time dependent random graphs, the time dependence being an effect of the underlying dynamical network laws. We formulate a kind of geometric renormalization group on these (random) networks leading to a hierarchy of increasingly coarse-grained networks of overlapping lumps. We provide arguments that this process may generate a fixed limit phase, representing our continuous space-time on a mesoscopic or macroscopic scale, provided that the underlying discrete geometry is critical in a specific sense (geometric long range order). Our point of view is corroborated by a series of analytic and numerical results, which allow us to keep track of the geometric changes, taking place on the various scales of the resolution of space-time. Of particular conceptual importance are the notions of dimension of such random systems on the various scales and the notion of geometric criticality

A novel heterogeneous training sample selection method on space-time adaptive processing

Science.gov (United States)

Wang, Qiang; Zhang, Yongshun; Guo, Yiduo

2018-04-01

The performance of ground target detection about space-time adaptive processing (STAP) decreases when non-homogeneity of clutter power is caused because of training samples contaminated by target-like signals. In order to solve this problem, a novel nonhomogeneous training sample selection method based on sample similarity is proposed, which converts the training sample selection into a convex optimization problem. Firstly, the existing deficiencies on the sample selection using generalized inner product (GIP) are analyzed. Secondly, the similarities of different training samples are obtained by calculating mean-hausdorff distance so as to reject the contaminated training samples. Thirdly, cell under test (CUT) and the residual training samples are projected into the orthogonal subspace of the target in the CUT, and mean-hausdorff distances between the projected CUT and training samples are calculated. Fourthly, the distances are sorted in order of value and the training samples which have the bigger value are selective preference to realize the reduced-dimension. Finally, simulation results with Mountain-Top data verify the effectiveness of the proposed method.

On fractal space-time and fractional calculus

Directory of Open Access Journals (Sweden)

Hu Yue

2016-01-01

Full Text Available This paper gives an explanation of fractional calculus in fractal space-time. On observable scales, continuum models can be used, however, when the scale tends to a smaller threshold, a fractional model has to be adopted to describe phenomena in micro/nano structure. A time-fractional Fornberg-Whitham equation is used as an example to elucidate the physical meaning of the fractional order, and its solution process is given by the fractional complex transform.

Capabilities of the Environmental Effects Branch at Marshall Space Flight Cente

Science.gov (United States)

Rogers, Jan; Finckenor, Miria; Nehls, Mary

2016-01-01

The Environmental Effects Branch at the Marshall Space Flight Center supports a myriad array of programs for NASA, DoD, and commercial space including human exploration, advanced space propulsion, improving life on Earth, and the study of the Sun, the Earth, and the solar system. The branch provides testing, evaluation, and qualification of materials for use on external spacecraft surfaces and in contamination-sensitive systems. Space environment capabilities include charged particle radiation, ultraviolet radiation, atomic oxygen, impact, plasma, and thermal vacuum, anchored by flight experiments and analysis of returned space hardware. These environmental components can be combined for solar wind or planetary surface environment studies or to evaluate synergistic effects. The Impact Testing Facility allows simulation of impacts ranging from sand and rain to micrometeoroids and orbital debris in order to evaluate materials and components for flight and ground-based systems. The Contamination Control Team is involved in the evaluation of environmentally-friendly replacements for HCFC-225 for use in propulsion oxygen systems, developing cleaning methods for additively manufactured hardware, and reducing risk for the Space Launch System.

Ecological Unequal Exchange: International Trade and Uneven Utilization of Environmental Space in the World System

Science.gov (United States)

Rice, James

2007-01-01

We evaluate the argument that international trade influences disproportionate cross-national utilization of global renewable natural resources. Such uneven dynamics are relevant to the consideration of inequitable appropriation of environmental space in particular and processes of ecological unequal exchange more generally. Using OLS regression…

Environmental Criteria in the Spanish Public Works Procurement Process

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José Luis Fuentes-Bargues

2017-02-01

Full Text Available Green Public Procurement (GPP is defined as a process of contracting products, services, and works with the least possible damage to the environment during their life cycle. In order to improve the knowledge about GPP, a study of the use of environmental tendering criteria in the Spanish public construction sector has been performed. The results of this study show that the use of environmental criteria in Spanish public sector construction procurement is low in comparison to a certain group of countries, known as “Green 7”, in the European Union. Environmental criteria is the fourth criterion in importance, but its weight in the global of the process is much lower than other criteria such as price, memory of the construction process and the delivery time. National administrations use environmental criteria more frequently because they have more resources and staff training about environmental issues. Environmental criteria are more used in the tendering of civil projects and works whose budget exceeds ten million euro due to the environmental impact of these kind and/or size of projects.

Joint Estimation and Decoding of Space-Time Trellis Codes

Directory of Open Access Journals (Sweden)

Zhang Jianqiu

2002-01-01

Full Text Available We explore the possibility of using an emerging tool in statistical signal processing, sequential importance sampling (SIS, for joint estimation and decoding of space-time trellis codes (STTC. First, we provide background on SIS, and then we discuss its application to space-time trellis code (STTC systems. It is shown through simulations that SIS is suitable for joint estimation and decoding of STTC with time-varying flat-fading channels when phase ambiguity is avoided. We used a design criterion for STTCs and temporally correlated channels that combats phase ambiguity without pilot signaling. We have shown by simulations that the design is valid.

NASA Space Technology Draft Roadmap Area 13: Ground and Launch Systems Processing

Science.gov (United States)

Clements, Greg

2011-01-01

This slide presentation reviews the technology development roadmap for the area of ground and launch systems processing. The scope of this technology area includes: (1) Assembly, integration, and processing of the launch vehicle, spacecraft, and payload hardware (2) Supply chain management (3) Transportation of hardware to the launch site (4) Transportation to and operations at the launch pad (5) Launch processing infrastructure and its ability to support future operations (6) Range, personnel, and facility safety capabilities (7) Launch and landing weather (8) Environmental impact mitigations for ground and launch operations (9) Launch control center operations and infrastructure (10) Mission integration and planning (11) Mission training for both ground and flight crew personnel (12) Mission control center operations and infrastructure (13) Telemetry and command processing and archiving (14) Recovery operations for flight crews, flight hardware, and returned samples. This technology roadmap also identifies ground, launch and mission technologies that will: (1) Dramatically transform future space operations, with significant improvement in life-cycle costs (2) Improve the quality of life on earth, while exploring in co-existence with the environment (3) Increase reliability and mission availability using low/zero maintenance materials and systems, comprehensive capabilities to ascertain and forecast system health/configuration, data integration, and the use of advanced/expert software systems (4) Enhance methods to assess safety and mission risk posture, which would allow for timely and better decision making. Several key technologies are identified, with a couple of slides devoted to one of these technologies (i.e., corrosion detection and prevention). Development of these technologies can enhance life on earth and have a major impact on how we can access space, eventually making routine commercial space access and improve building and manufacturing, and weather

Integrated Logistics Support Analysis of the International Space Station Alpha: An Overview of the Maintenance Time Dependent Parameter Prediction Methods Enhancement

Science.gov (United States)

Sepehry-Fard, F.; Coulthard, Maurice H.

1995-01-01

The objective of this publication is to introduce the enhancement methods for the overall reliability and maintainability methods of assessment on the International Space Station. It is essential that the process to predict the values of the maintenance time dependent variable parameters such as mean time between failure (MTBF) over time do not in themselves generate uncontrolled deviation in the results of the ILS analysis such as life cycle costs, spares calculation, etc. Furthermore, the very acute problems of micrometeorite, Cosmic rays, flares, atomic oxygen, ionization effects, orbital plumes and all the other factors that differentiate maintainable space operations from non-maintainable space operations and/or ground operations must be accounted for. Therefore, these parameters need be subjected to a special and complex process. Since reliability and maintainability strongly depend on the operating conditions that are encountered during the entire life of the International Space Station, it is important that such conditions are accurately identified at the beginning of the logistics support requirements process. Environmental conditions which exert a strong influence on International Space Station will be discussed in this report. Concurrent (combined) space environments may be more detrimental to the reliability and maintainability of the International Space Station than the effects of a single environment. In characterizing the logistics support requirements process, the developed design/test criteria must consider both the single and/or combined environments in anticipation of providing hardware capability to withstand the hazards of the International Space Station profile. The effects of the combined environments (typical) in a matrix relationship on the International Space Station will be shown. The combinations of the environments where the total effect is more damaging than the cumulative effects of the environments acting singly, may include a

Multi-disciplinary techniques for understanding time-varying space-based imagery

Science.gov (United States)

Casasent, D.; Sanderson, A.; Kanade, T.

1984-06-01

A multidisciplinary program for space-based image processing is reported. This project combines optical and digital processing techniques and pattern recognition, image understanding and artificial intelligence methodologies. Time change image processing was recognized as the key issue to be addressed. Three time change scenarios were defined based on the frame rate of the data change. This report details the recent research on: various statistical and deterministic image features, recognition of sub-pixel targets in time varying imagery, and 3-D object modeling and recognition.

Time travel in Goedel's space

International Nuclear Information System (INIS)

Pfarr, J.

1981-01-01

An analysis is presented of the motion of test particles in Goedel's universe. Both geodesical and nongeodesical motions are considered; the accelerations for nongeodesical motions are given. Examples for closed timelike world lines are shown and the dynamical conditions for time travel in Goedel's space-time are discussed. It is shown that these conditions alone do not suffice to exclude time travel in Goedel's space-time. (author)

Quantum fields in curved space-times

International Nuclear Information System (INIS)

Ashtekar, A.; Magnon, A.

1975-01-01

The problem of obtaining a quantum description of the (real) Klein-Gordon system in a given curved space-time is discussed. An algebraic approach is used. The *-algebra of quantum operators is constructed explicitly and the problem of finding its *-representation is reduced to that of selecting a suitable complex structure on the real vector space of the solutions of the (classical) Klein-Gordon equation. Since, in a static space-time, there already exists, a satisfactory quantum field theory, in this case one already knows what the 'correct' complex structure is. A physical characterization of this 'correct' complex structure is obtained. This characterization is used to extend quantum field theory to non-static space-times. Stationary space-times are considered first. In this case, the issue of extension is completely straightforward and the resulting theory is the natural generalization of the one in static space-times. General, non-stationary space-times are then considered. In this case the issue of extension is quite complicated and only a plausible extension is presented. Although the resulting framework is well-defined mathematically, the physical interpretation associated with it is rather unconventional. Merits and weaknesses of this framework are discussed. (author)

On the differentiability of space-time

International Nuclear Information System (INIS)

Clarke, C.J.S.

1977-01-01

It is shown that the differentiability of a space-time is implied by that of its Riemann tensor, assuming a priori only boundedness of the first derivations of the metric. Consequently all the results on space-time singularities proved in earlier papers by the author hold true in C 2- space-times. (author)

Acoustic mode coupling induced by shallow water nonlinear internal waves: sensitivity to environmental conditions and space-time scales of internal waves.

Science.gov (United States)

Colosi, John A

2008-09-01

While many results have been intuited from numerical simulation studies, the precise connections between shallow-water acoustic variability and the space-time scales of nonlinear internal waves (NLIWs) as well as the background environmental conditions have not been clearly established analytically. Two-dimensional coupled mode propagation through NLIWs is examined using a perturbation series solution in which each order n is associated with nth-order multiple scattering. Importantly, the perturbation solution gives resonance conditions that pick out specific NLIW scales that cause coupling, and seabed attenuation is demonstrated to broaden these resonances, fundamentally changing the coupling behavior at low frequency. Sound-speed inhomogeneities caused by internal solitary waves (ISWs) are primarily considered and the dependence of mode coupling on ISW amplitude, range width, depth structure, location relative to the source, and packet characteristics are delineated as a function of acoustic frequency. In addition, it is seen that significant energy transfer to modes with initially low or zero energy involves at least a second order scattering process. Under moderate scattering conditions, comparisons of first order, single scattering theoretical predictions to direct numerical simulation demonstrate the accuracy of the approach for acoustic frequencies upto 400 Hz and for single as well as multiple ISW wave packets.

pySPACE - A Signal Processing and Classification Environment in Python

Directory of Open Access Journals (Sweden)

Mario Michael Krell

2013-12-01

Full Text Available In neuroscience large amounts of data are recorded to provide insights into cerebral information processing and function. The successful extraction of the relevant signals becomes more and more challenging due to increasing complexities in acquisition techniques and questions addressed. Here, automated signal processing and machine learning tools can help to process the data, e.g., to separate signal and noise. With the presented software pySPACE (http://pyspace.github.io/pyspace, signal processing algorithms can be compared and applied automatically on time series data, either with the aim of finding a suitable preprocessing, or of training supervised algorithms to classify the data. pySPACE originally has been built to process multi-sensor windowed time series data, like event-related potentials from the electroencephalogram (EEG. The software provides automated data handling, distributed processing, modular build-up of signal processing chains and tools for visualization and performance evaluation. Included in the software are various algorithms like temporal and spatial filters, feature generation and selection, classification algorithms and evaluation schemes. Further, interfaces to other signal processing tools are provided and, since pySPACE is a modular framework, it can be extended with new algorithms according to individual needs. In the presented work, the structural hierarchies are described. It is illustrated how users and developers can interface the software and execute offline and online modes. Configuration of pySPACE is realized with the YAML format, so that programming skills are not mandatory for usage. The concept of pySPACE is to have one comprehensive tool that can be used to perform complete signal processing and classification tasks. It further allows to define own algorithms, or to integrate and use already existing libraries.

Time Synchronization and Distribution Mechanisms for Space Networks

Science.gov (United States)

Woo, Simon S.; Gao, Jay L.; Clare, Loren P.; Mills, David L.

2011-01-01

This work discusses research on the problems of synchronizing and distributing time information between spacecraft based on the Network Time Protocol (NTP), where NTP is a standard time synchronization protocol widely used in the terrestrial network. The Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol was designed and developed for synchronizing spacecraft that are in proximity where proximity is less than 100,000 km distant. A particular application is synchronization between a Mars orbiter and rover. Lunar scenarios as well as outer-planet deep space mother-ship-probe missions may also apply. Spacecraft with more accurate time information functions as a time-server, and the other spacecraft functions as a time-client. PITS can be easily integrated and adaptable to the CCSDS Proximity-1 Space Link Protocol with minor modifications. In particular, PITS can take advantage of the timestamping strategy that underlying link layer functionality provides for accurate time offset calculation. The PITS algorithm achieves time synchronization with eight consecutive space network time packet exchanges between two spacecraft. PITS can detect and avoid possible errors from receiving duplicate and out-of-order packets by comparing with the current state variables and timestamps. Further, PITS is able to detect error events and autonomously recover from unexpected events that can possibly occur during the time synchronization and distribution process. This capability achieves an additional level of protocol protection on top of CRC or Error Correction Codes. PITS is a lightweight and efficient protocol, eliminating the needs for explicit frame sequence number and long buffer storage. The PITS protocol is capable of providing time synchronization and distribution services for a more general domain where multiple entities need to achieve time synchronization using a single point-to-point link.

How Body Orientation Affects Concepts of Space, Time and Valence: Functional Relevance of Integrating Sensorimotor Experiences during Word Processing.

Directory of Open Access Journals (Sweden)

Martin Lachmair

Full Text Available The aim of the present study was to test the functional relevance of the spatial concepts UP or DOWN for words that use these concepts either literally (space or metaphorically (time, valence. A functional relevance would imply a symmetrical relationship between the spatial concepts and words related to these concepts, showing that processing words activate the related spatial concepts on one hand, but also that an activation of the concepts will ease the retrieval of a related word on the other. For the latter, the rotation angle of participant's body position was manipulated either to an upright or a head-down tilted body position to activate the related spatial concept. Afterwards participants produced in a within-subject design previously memorized words of the concepts space, time and valence according to the pace of a metronome. All words were related either to the spatial concept UP or DOWN. The results including Bayesian analyses show (1 a significant interaction between body position and words using the concepts UP and DOWN literally, (2 a marginal significant interaction between body position and temporal words and (3 no effect between body position and valence words. However, post-hoc analyses suggest no difference between experiments. Thus, the authors concluded that integrating sensorimotor experiences is indeed of functional relevance for all three concepts of space, time and valence. However, the strength of this functional relevance depends on how close words are linked to mental concepts representing vertical space.

Space Station Freedom Environmental Health Care Program

Science.gov (United States)

Richard, Elizabeth E.; Russo, Dane M.

1992-01-01

The paper discusses the environmental planning and monitoring aspects of the Space Station Freedom (SSF) Environmental Health Care Program, which encompasses all phases of the SSF assembly and operation from the first element entry at MB-6 through the Permanent Manned Capability and beyond. Environmental planning involves the definition of acceptability limits and monitoring requirements for the radiation dose barothermal parameters and potential contaminants in the SSF air and water and on internal surfaces. Inflight monitoring will be implemented through the Environmental Health System, which consists of five subsystems: Microbiology, Toxicology, Water Quality, Radiation, and Barothermal Physiology. In addition to the environmental data interpretation and analysis conducted after each mission, the new data will be compared to archived data for statistical and long-term trend analysis and determination of risk exposures. Results of these analyses will be used to modify the acceptability limits and monitoring requirements for the future.

Matter fields in curved space-time

International Nuclear Information System (INIS)

Viet, Nguyen Ai; Wali, Kameshwar C.

2000-01-01

We study the geometry of a two-sheeted space-time within the framework of non-commutative geometry. As a prelude to the Standard Model in curved space-time, we present a model of a left- and a right- chiral field living on the two sheeted-space time and construct the action functionals that describe their interactions

26th Space Simulation Conference Proceedings. Environmental Testing: The Path Forward

Science.gov (United States)

Packard, Edward A.

2010-01-01

Topics covered include: A Multifunctional Space Environment Simulation Facility for Accelerated Spacecraft Materials Testing; Exposure of Spacecraft Surface Coatings in a Simulated GEO Radiation Environment; Gravity-Offloading System for Large-Displacement Ground Testing of Spacecraft Mechanisms; Microscopic Shutters Controlled by cRIO in Sounding Rocket; Application of a Physics-Based Stabilization Criterion to Flight System Thermal Testing; Upgrade of a Thermal Vacuum Chamber for 20 Kelvin Operations; A New Approach to Improve the Uniformity of Solar Simulator; A Perfect Space Simulation Storm; A Planetary Environmental Simulator/Test Facility; Collimation Mirror Segment Refurbishment inside ESA s Large Space; Space Simulation of the CBERS 3 and 4 Satellite Thermal Model in the New Brazilian 6x8m Thermal Vacuum Chamber; The Certification of Environmental Chambers for Testing Flight Hardware; Space Systems Environmental Test Facility Database (SSETFD), Website Development Status; Wallops Flight Facility: Current and Future Test Capabilities for Suborbital and Orbital Projects; Force Limited Vibration Testing of JWST NIRSpec Instrument Using Strain Gages; Investigation of Acoustic Field Uniformity in Direct Field Acoustic Testing; Recent Developments in Direct Field Acoustic Testing; Assembly, Integration and Test Centre in Malaysia: Integration between Building Construction Works and Equipment Installation; Complex Ground Support Equipment for Satellite Thermal Vacuum Test; Effect of Charging Electron Exposure on 1064nm Transmission through Bare Sapphire Optics and SiO2 over HfO2 AR-Coated Sapphire Optics; Environmental Testing Activities and Capabilities for Turkish Space Industry; Integrated Circuit Reliability Simulation in Space Environments; Micrometeoroid Impacts and Optical Scatter in Space Environment; Overcoming Unintended Consequences of Ambient Pressure Thermal Cycling Environmental Tests; Performance and Functionality Improvements to Next Generation

Asymptotic behaviour of time averages for non-ergodic Gaussian processes

Science.gov (United States)

Ślęzak, Jakub

2017-08-01

In this work, we study the behaviour of time-averages for stationary (non-ageing), but ergodicity-breaking Gaussian processes using their representation in Fourier space. We provide explicit formulae for various time-averaged quantities, such as mean square displacement, density, and analyse the behaviour of time-averaged characteristic function, which gives insight into rich memory structure of the studied processes. Moreover, we show applications of the ergodic criteria in Fourier space, determining the ergodicity of the generalised Langevin equation's solutions.

Modeling nonstationarity in space and time.

Science.gov (United States)

Shand, Lyndsay; Li, Bo

2017-09-01

We propose to model a spatio-temporal random field that has nonstationary covariance structure in both space and time domains by applying the concept of the dimension expansion method in Bornn et al. (2012). Simulations are conducted for both separable and nonseparable space-time covariance models, and the model is also illustrated with a streamflow dataset. Both simulation and data analyses show that modeling nonstationarity in both space and time can improve the predictive performance over stationary covariance models or models that are nonstationary in space but stationary in time. © 2017, The International Biometric Society.

Space Environmental Effects on Candidate Solar Sail Materials

Science.gov (United States)

Edwards, David L.; Nehls, Mary; Semmel, Charles; Hovater, Mary; Gray, Perry; Hubbs, Whitney; Wertz, George

2004-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) continues research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted ot a solar sail can be increased, up to a factor of two, if the sun-facing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. Near term solar sail propelled science missions are targeting the Lagrange point 1 (L1) as well as locations sunward of L1 as destinations. These near term missions include the Solar Polar Imager and the L1 Diamond. The Environmental Effects Group at NASA's Marshall Space Flight Center (MSFC) continues to actively characterize solar sail material in preparation for these near term solar sail missions. Previous investigations indicated that space environmental effects on sail material thermo-optical properties were minimal and would not significantly affect the propulsion efficiency of the sail. These investigations also indicated that the sail material mechanical stability degrades with increasing radiation exposure. This paper will further quantify the effect of space environmental exposure on the mechanical properties of candidate sail materials. Candidate sail materials for these missions include Aluminum coated Mylar, Teonex, and CP1 (Colorless Polyimide). These materials were subjected to uniform radiation doses of electrons and protons in individual exposures sequences. Dose values ranged from 100 Mrads to over 5 Grads. The engineering performance property responses of thermo-optical and mechanical properties were characterized

Changes in the representation of space and time while listening to music.

Science.gov (United States)

Schäfer, Thomas; Fachner, Jörg; Smukalla, Mario

2013-01-01

Music is known to alter people's ordinary experience of space and time. Not only does this challenge the concept of invariant space and time tacitly assumed in psychology but it may also help us understand how music works and how music can be understood as an embodied experience. Yet research about these alterations is in its infancy. This review is intended to delineate a future research agenda. We review experimental evidence and subjective reports of the influence of music on the representation of space and time and present prominent approaches to explaining these effects. We discuss the role of absorption and altered states of consciousness and their associated changes in attention and neurophysiological processes, as well as prominent models of human time processing and time experience. After integrating the reviewed research, we conclude that research on the influence of music on the representation of space and time is still quite inconclusive but that integrating the different approaches could lead to a better understanding of the observed effects. We also provide a working model that integrates a large part of the evidence and theories. Several suggestions for further research in both music psychology and cognitive psychology are outlined.

Changes in the representation of space and time while listening to music

Science.gov (United States)

Schäfer, Thomas; Fachner, Jörg; Smukalla, Mario

2013-01-01

Music is known to alter people's ordinary experience of space and time. Not only does this challenge the concept of invariant space and time tacitly assumed in psychology but it may also help us understand how music works and how music can be understood as an embodied experience. Yet research about these alterations is in its infancy. This review is intended to delineate a future research agenda. We review experimental evidence and subjective reports of the influence of music on the representation of space and time and present prominent approaches to explaining these effects. We discuss the role of absorption and altered states of consciousness and their associated changes in attention and neurophysiological processes, as well as prominent models of human time processing and time experience. After integrating the reviewed research, we conclude that research on the influence of music on the representation of space and time is still quite inconclusive but that integrating the different approaches could lead to a better understanding of the observed effects. We also provide a working model that integrates a large part of the evidence and theories. Several suggestions for further research in both music psychology and cognitive psychology are outlined. PMID:23964254

28 CFR 91.58 - Timing of the environmental review process.

Science.gov (United States)

2010-07-01

... CORRECTIONAL FACILITIES Environmental Impact Review Procedures for VOI/TIS Grant Program Environmental Review... anticipated environmental impacts, an environmental impact statement should be initiated. (c) Design phase... projects under construction, OJP will work with the States to determine what environmental analysis has...

Being In-Between: Reflecting on Time, Space and Career during the Tenure Application Process

Science.gov (United States)

Eichler, Mathew

2015-01-01

Part of the process of becoming a tenured faculty member is applying for tenure. This reflective essay reports on the period after the submission of tenure materials for review but before the review process for tenure is completed. This is an "in-between" space, where the race of the tenure track is no longer present, but the role of…

Research on Control Method Based on Real-Time Operational Reliability Evaluation for Space Manipulator

Directory of Open Access Journals (Sweden)

Yifan Wang

2014-05-01

Full Text Available A control method based on real-time operational reliability evaluation for space manipulator is presented for improving the success rate of a manipulator during the execution of a task. In this paper, a method for quantitative analysis of operational reliability is given when manipulator is executing a specified task; then a control model which could control the quantitative operational reliability is built. First, the control process is described by using a state space equation. Second, process parameters are estimated in real time using Bayesian method. Third, the expression of the system's real-time operational reliability is deduced based on the state space equation and process parameters which are estimated using Bayesian method. Finally, a control variable regulation strategy which considers the cost of control is given based on the Theory of Statistical Process Control. It is shown via simulations that this method effectively improves the operational reliability of space manipulator control system.

On the data processing related to environmental radioactivity

International Nuclear Information System (INIS)

Nakamura, Isamu

1984-01-01

The monitoring and measurement of environmental radioactivity have been undertaken by many organizations in Japan. The Japan Chemical Analysis Center has been entrusted by the government to gather and edit these measured results. The computer processing of these data started in 1978, and it is expected that by the end of fiscal year 1984, all fallout data since 1957 and all radioactivity monitoring data since 1969 can be registered. The computer programs for processing the data such as the output of tables and figures have also been developed, and the edition of reports has been made. The replacement of the computer and the development of a new processing system capable of handing Kanji (Japanese-Chinese characters) are now scheduled. This document outlines the data system such as the quality, quantity and origin of the measured data and the frequency of report publication. Some results of the analysis of fallout nuclides, space gamma dose rate and the total β-activity in rain are presented. The effects of the nuclear explosion tests in China are very obvious in these figures. A chronological table of the explosion tests in China is also presented. The different effects of time lag at the different places of measurement are also seen. The effects of the presence of nuclear power plants were also investigated at some sites of the plants, but no discernible effect was observed. (Aoki, K.)

Space-Time and Architecture

Science.gov (United States)

Field, F.; Goodbun, J.; Watson, V.

Architects have a role to play in interplanetary space that has barely yet been explored. The architectural community is largely unaware of this new territory, for which there is still no agreed method of practice. There is moreover a general confusion, in scientific and related fields, over what architects might actually do there today. Current extra-planetary designs generally fail to explore the dynamic and relational nature of space-time, and often reduce human habitation to a purely functional problem. This is compounded by a crisis over the representation (drawing) of space-time. The present work returns to first principles of architecture in order to realign them with current socio-economic and technological trends surrounding the space industry. What emerges is simultaneously the basis for an ecological space architecture, and the representational strategies necessary to draw it. We explore this approach through a work of design-based research that describes the construction of Ocean; a huge body of water formed by the collision of two asteroids at the Translunar Lagrange Point (L2), that would serve as a site for colonisation, and as a resource to fuel future missions. Ocean is an experimental model for extra-planetary space design and its representation, within the autonomous discipline of architecture.

The topology of geodesically complete space-times

International Nuclear Information System (INIS)

Lee, C.W.

1983-01-01

Two theorems are given on the topology of geodesically complete space-times which satisfy the energy condition. Firstly, the condition that a compact embedded 3-manifold in space-time be dentless is defined in terms of causal structure. Then it is shown that a dentless 3-manifold must separate space-time, and that it must enclose a compact portion of space-time. Further, it is shown that if the dentless 3-manifold is homeomorphic to S 3 then the part of space-time that it encloses must be simply connected. (author)

Philosophy of physics space and time

CERN Document Server

Maudlin, Tim

2012-01-01

This concise book introduces nonphysicists to the core philosophical issues surrounding the nature and structure of space and time, and is also an ideal resource for physicists interested in the conceptual foundations of space-time theory. Tim Maudlin's broad historical overview examines Aristotelian and Newtonian accounts of space and time, and traces how Galileo's conceptions of relativity and space-time led to Einstein's special and general theories of relativity. Maudlin explains special relativity using a geometrical approach, emphasizing intrinsic space-time structure rather than coordinate systems or reference frames. He gives readers enough detail about special relativity to solve concrete physical problems while presenting general relativity in a more qualitative way, with an informative discussion of the geometrization of gravity, the bending of light, and black holes. Additional topics include the Twins Paradox, the physical aspects of the Lorentz-FitzGerald contraction, the constancy of the speed...

Semiclassical expanding discrete space-times

International Nuclear Information System (INIS)

Cobb, W.K.; Smalley, L.L.

1981-01-01

Given the close ties between general relativity and geometry one might reasonably expect that quantum effects associated with gravitation might also be tied to the geometry of space-time, namely, to some sort of discreteness in space-time itself. In particular it is supposed that space-time consists of a discrete lattice of points rather than the usual continuum. Since astronomical evidence seems to suggest that the universe is expanding, the lattice must also expand. Some of the implications of such a model are that the proton should presently be stable, and the universe should be closed although the mechanism for closure is quantum mechanical. (author)

Frequency Adaptability and Waveform Design for OFDM Radar Space-Time Adaptive Processing

Energy Technology Data Exchange (ETDEWEB)

Sen, Satyabrata [ORNL; Glover, Charles Wayne [ORNL

2012-01-01

We propose an adaptive waveform design technique for an orthogonal frequency division multiplexing (OFDM) radar signal employing a space-time adaptive processing (STAP) technique. We observe that there are inherent variabilities of the target and interference responses in the frequency domain. Therefore, the use of an OFDM signal can not only increase the frequency diversity of our system, but also improve the target detectability by adaptively modifying the OFDM coefficients in order to exploit the frequency-variabilities of the scenario. First, we formulate a realistic OFDM-STAP measurement model considering the sparse nature of the target and interference spectra in the spatio-temporal domain. Then, we show that the optimal STAP-filter weight-vector is equal to the generalized eigenvector corresponding to the minimum generalized eigenvalue of the interference and target covariance matrices. With numerical examples we demonstrate that the resultant OFDM-STAP filter-weights are adaptable to the frequency-variabilities of the target and interference responses, in addition to the spatio-temporal variabilities. Hence, by better utilizing the frequency variabilities, we propose an adaptive OFDM-waveform design technique, and consequently gain a significant amount of STAP-performance improvement.

OFDM Radar Space-Time Adaptive Processing by Exploiting Spatio-Temporal Sparsity

Energy Technology Data Exchange (ETDEWEB)

Sen, Satyabrata [ORNL

2013-01-01

We propose a sparsity-based space-time adaptive processing (STAP) algorithm to detect a slowly-moving target using an orthogonal frequency division multiplexing (OFDM) radar. We observe that the target and interference spectra are inherently sparse in the spatio-temporal domain. Hence, we exploit that sparsity to develop an efficient STAP technique that utilizes considerably lesser number of secondary data and produces an equivalent performance as the other existing STAP techniques. In addition, the use of an OFDM signal increases the frequency diversity of our system, as different scattering centers of a target resonate at different frequencies, and thus improves the target detectability. First, we formulate a realistic sparse-measurement model for an OFDM radar considering both the clutter and jammer as the interfering sources. Then, we apply a residual sparse-recovery technique based on the LASSO estimator to estimate the target and interference covariance matrices, and subsequently compute the optimal STAP-filter weights. Our numerical results demonstrate a comparative performance analysis of the proposed sparse-STAP algorithm with four other existing STAP methods. Furthermore, we discover that the OFDM-STAP filter-weights are adaptable to the frequency-variabilities of the target and interference responses, in addition to the spatio-temporal variabilities. Hence, by better utilizing the frequency variabilities, we propose an adaptive OFDM-waveform design technique, and consequently gain a significant amount of STAP-performance improvement.

Exploration Space Suit Architecture and Destination Environmental-Based Technology Development

Science.gov (United States)

Hill, Terry R.; McFarland, Shane M.; Korona, F. Adam

2013-01-01

This paper continues forward where EVA Space Suit Architecture: Low Earth Orbit Vs. Moon Vs. Mars left off in the development of a space suit architecture that is modular in design and could be reconfigured prior to launch or during any given mission depending on the tasks or destination. This space suit system architecture and technologies required based on human exploration (EVA) destinations will be discussed, and how these systems should evolve to meet the future exploration EVA needs of the US human space flight program. A series of exercises and analyses provided a strong indication that the Constellation Program space suit architecture, with its maximum reuse of technology and functionality across a range of mission profiles and destinations, is postured to provide a viable solution for future space exploration missions. The destination environmental analysis demonstrates that the modular architecture approach could provide the lowest mass and mission cost for the protection of the crew, given any human mission outside of low-Earth orbit. Additionally, some of the high-level trades presented here provide a review of the environmental and nonenvironmental design drivers that will become increasingly important as humans venture farther from Earth. The presentation of destination environmental data demonstrates a logical clustering of destination design environments that allows a focused approach to technology prioritization, development, and design that will maximize the return on investment, largely independent of any particular design reference mission.

Evolution in Many-Sheeted Space-time

OpenAIRE

Pitkänen, Matti

2010-01-01

The topics of the article has been restricted to those, which seem to represent the most well-established ideas about evolution in many-sheeted space-time. a) Basic facts about and TGD based model for pre-biotic evolution are discussed. b) A model for the ATP-ADP process based on DNA as topological quantum computer vision, the identification of universal metabolic energy quanta in terms of zero point kinetic energies, and the notion of remote metabolism is discussed. c) A model f...

Fermion systems in discrete space-time

International Nuclear Information System (INIS)

Finster, Felix

2007-01-01

Fermion systems in discrete space-time are introduced as a model for physics on the Planck scale. We set up a variational principle which describes a non-local interaction of all fermions. This variational principle is symmetric under permutations of the discrete space-time points. We explain how for minimizers of the variational principle, the fermions spontaneously break this permutation symmetry and induce on space-time a discrete causal structure

Fermion systems in discrete space-time

Energy Technology Data Exchange (ETDEWEB)

Finster, Felix [NWF I - Mathematik, Universitaet Regensburg, 93040 Regensburg (Germany)

2007-05-15

Fermion systems in discrete space-time are introduced as a model for physics on the Planck scale. We set up a variational principle which describes a non-local interaction of all fermions. This variational principle is symmetric under permutations of the discrete space-time points. We explain how for minimizers of the variational principle, the fermions spontaneously break this permutation symmetry and induce on space-time a discrete causal structure.

Fermion Systems in Discrete Space-Time

OpenAIRE

Finster, Felix

2006-01-01

Fermion systems in discrete space-time are introduced as a model for physics on the Planck scale. We set up a variational principle which describes a non-local interaction of all fermions. This variational principle is symmetric under permutations of the discrete space-time points. We explain how for minimizers of the variational principle, the fermions spontaneously break this permutation symmetry and induce on space-time a discrete causal structure.

Fermion systems in discrete space-time

Science.gov (United States)

Finster, Felix

2007-05-01

Fermion systems in discrete space-time are introduced as a model for physics on the Planck scale. We set up a variational principle which describes a non-local interaction of all fermions. This variational principle is symmetric under permutations of the discrete space-time points. We explain how for minimizers of the variational principle, the fermions spontaneously break this permutation symmetry and induce on space-time a discrete causal structure.

On renormalisation of lambda phi4 field theory in curved space-time

International Nuclear Information System (INIS)

Bunch, T.S.; Panangaden, P.

1980-01-01

An explicit renormalisation of all second-order physical processes occurring in lambdaphi 4 field theory in conformally flat space-time, including vacuum-to-vacuum processes, is performed. Although divergences dependent on the definition of the vacuum state appear in some Feynman diagrams, physical amplitudes obtained by summing all diagrams which contribute to a single physical process are independent of these divergences. Consequently, the theory remains renormalisable in curved space-time, at least to second order in lambda. Renormalisations of the mass m, the coupling constant lambda and the constant xi which couples the field to the Ricci scalar are required to make two- and four-particle creation amplitudes finite. (author)

Time and space: undergraduate Mexican physics in motion

Science.gov (United States)

Candela, Antonia

2010-09-01

This is an ethnographic study of the trajectories and itineraries of undergraduate physics students at a Mexican university. In this work learning is understood as being able to move oneself and, other things (cultural tools), through the space-time networks of a discipline (Nespor in Knowledge in motion: space, time and curriculum in undergraduate physics and management. Routledge Farmer, London, 1994). The potential of this socio-cultural perspective allows an analysis of how students are connected through extended spaces and times with an international core discipline as well as with cultural features related to local networks of power and construction. Through an example, I show that, from an actor-network-theory (Latour in Science in action. Harvard University Press, Cambridge, 1987), that in order to understand the complexities of undergraduate physics processes of learning you have to break classroom walls and take into account students' movements through complex spatial and temporal traces of the discipline of physics. Mexican professors do not give classes following one textbook but in a moment-to-moment open dynamism tending to include undergraduate students as actors in classroom events extending the teaching space-time of the classroom to the disciplinary research work of physics. I also find that Mexican undergraduate students show initiative and display some autonomy and power in the construction of their itineraries as they are encouraged to examine a variety of sources including contemporary research articles, unsolved physics problems, and even to participate in several physicists' spaces, as for example being speakers at the national congresses of physics. Their itineraries also open up new spaces of cultural and social practices, creating more extensive networks beyond those associated with a discipline. Some economic, historical and cultural contextual features of this school of sciences are analyzed in order to help understanding the particular

Characterization of Candidate Solar Sail Material Exposed to Space Environmental Effects

Science.gov (United States)

Edwards, David; Hovater, Mary; Hubbs, Whitney; Wertz, George; Hollerman, William; Gray, Perry

2003-01-01

Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Solar sails are not limited by reaction mass and provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Once thought to be difficult or impossible, solar sailing has come out of science fiction and into the realm of possibility. Any spacecraft using this method would need to deploy a thin sail that could be as large as many kilometers in extent. The availability of strong, ultra lightweight, and radiation resistant materials will determine the future of solar sailing. The National Aeronautics and Space Administration's Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra lightweight materials for spacecraft propulsion. The Space Environmental Effects Team at MSFC is actively characterizing candidate solar sail material to evaluate the thermo-optical and mechanical properties after exposure to space environmental effects. This paper will describe the exposure of candidate solar sail materials to emulated space environmental effects including energetic electrons, combined electrons and Ultraviolet radiation, and hypervelocity impact of irradiated solar sail material. This paper will describe the testing procedure and the material characterization results of this investigation.

Alamos: An International Collaboration to Provide a Space Based Environmental Monitoring Solution for the Deep Space Network

Science.gov (United States)

Kennedy, S. O.; Dunn, A.; Lecomte, J.; Buchheim, K.; Johansson, E.; Berger, T.

2018-02-01

This abstract proposes the advantages of an externally mounted instrument in support of the human physiology, space biology, and human health and performance key science area. Alamos provides Space-Based Environmental Monitoring capabilities.

Space-Time Dependent Transport, Activation, and Dose Rates for Radioactivated Fluids.

Science.gov (United States)

Gavazza, Sergio

Two methods are developed to calculate the space - and time-dependent mass transport of radionuclides, their production and decay, and the associated dose rates generated from the radioactivated fluids flowing through pipes. The work couples space- and time-dependent phenomena, treated as only space- or time-dependent in the open literature. The transport and activation methodology (TAM) is used to numerically calculate space- and time-dependent transport and activation of radionuclides in fluids flowing through pipes exposed to radiation fields, and volumetric radioactive sources created by radionuclide motions. The computer program Radionuclide Activation and Transport in Pipe (RNATPA1) performs the numerical calculations required in TAM. The gamma ray dose methodology (GAM) is used to numerically calculate space- and time-dependent gamma ray dose equivalent rates from the volumetric radioactive sources determined by TAM. The computer program Gamma Ray Dose Equivalent Rate (GRDOSER) performs the numerical calculations required in GAM. The scope of conditions considered by TAM and GAM herein include (a) laminar flow in straight pipe, (b)recirculating flow schemes, (c) time-independent fluid velocity distributions, (d) space-dependent monoenergetic neutron flux distribution, (e) space- and time-dependent activation process of a single parent nuclide and transport and decay of a single daughter radionuclide, and (f) assessment of space- and time-dependent gamma ray dose rates, outside the pipe, generated by the space- and time-dependent source term distributions inside of it. The methodologies, however, can be easily extended to include all the situations of interest for solving the phenomena addressed in this dissertation. A comparison is made from results obtained by the described calculational procedures with analytical expressions. The physics of the problems addressed by the new technique and the increased accuracy versus non -space and time-dependent methods

Changes in the representation of space and time while listening to music

Directory of Open Access Journals (Sweden)

Thomas eSchäfer

2013-08-01

Full Text Available Music is known to alter people’s ordinary experience of space and time. Not only does this challenge the concept of invariant space and time tacitly assumed in psychology but it may also help us understand how music works and how music can be understood as an embodied experience. Yet research about these alterations is in its infancy. This review is intended to delineate a future research agenda. We review experimental evidence and subjective reports of the influence of music on the representation of space and time and present prominent approaches to explaining these effects. We discuss the role of absorption and altered states of consciousness and their associated changes in attention and neurophysiological processes, as well as prominent models of human time processing and time experience. After integrating the reviewed research, we conclude that research on the influence of music on the representation of space and time is still quite inconclusive but that integrating the different approaches could lead to a better understanding of the observed effects. We also provide a working model that integrates a large part of the evidence and theories. Several suggestions for further research in both music psychology and cognitive psychology are outlined.

El Naschie's Cantorian space-time and general relativity by means of Barbilian's group. A Cantorian fractal axiomatic model of space-time

International Nuclear Information System (INIS)

Gottlieb, I.; Agop, M.; Jarcau, M.

2004-01-01

One builds the vacuum metrics of the stationary electromagnetic field through the complex potential model. There are thus emphasized both a variational principle, independent on the Ricci tensor, and some internal symmetries of the vacuum solutions. One shows that similar results may be obtained using the Barbiliant's group. By analytical continuation of a Barbilian transformation the link between the fixed points of the modular groups of the vacuum and the golden mean PHI=(1/(1+PHI))=(√5-1)/2 of ε (∞) space-time is established. Finally, a Cantorian fractal axiomatic model of the space-time is presented. The model is explained using a set of coupled equations which may describe the self organizing processes at the solid-liquid, plasma-plasma, and superconductor-superconductor interfaces

Possibility of extending space-time coordinates

International Nuclear Information System (INIS)

Wang Yongcheng.

1993-11-01

It has been shown that one coordinate system can describe a whole space-time region except some supersurfaces on which there are coordinate singularities. The conditions of extending a coordinate from real field to complex field are studied. It has been shown that many-valued coordinate transformations may help us to extend space-time regions and many-valued metric functions may make one coordinate region to describe more than one space-time regions. (author). 11 refs

Some Peculiarities of Newton-Hooke Space-Times

OpenAIRE

Tian, Yu

2011-01-01

Newton-Hooke space-times are the non-relativistic limit of (anti-)de Sitter space-times. We investigate some peculiar facts about the Newton-Hooke space-times, among which the "extraordinary Newton-Hooke quantum mechanics" and the "anomalous Newton-Hooke space-times" are discussed in detail. Analysis on the Lagrangian/action formalism is performed in the discussion of the Newton-Hooke quantum mechanics, where the path integral point of view plays an important role, and the physically measurab...

Relativity Based on Physical Processes Rather Than Space-Time

Science.gov (United States)

Giese, Albrecht

2013-09-01

Physicists' understanding of relativity and the way it is handled is at present dominated by the interpretation of Albert Einstein, who related relativity to specific properties of space and time. The principal alternative to Einstein's interpretation is based on a concept proposed by Hendrik A. Lorentz, which uses knowledge of classical physics to explain relativistic phenomena. In this paper, we will show that on the one hand the Lorentz-based interpretation provides a simpler mathematical way of arriving at the known results for both Special and General Relativity. On the other hand, it is able to solve problems which have remained open to this day. Furthermore, a particle model will be presented, based on Lorentzian relativity, which explains the origin of mass without the use of the Higgs mechanism, based on the finiteness of the speed of light, and which provides the classical results for particle properties that are currently only accessible through quantum mechanics.

A Cantorian potential theory for describing dynamical systems on El Naschie's space-time

International Nuclear Information System (INIS)

Iovane, G.; Gargiulo, G.; Zappale, E.

2006-01-01

In this paper we analyze classical systems, in which motion is not on a classical continuous path, but rather on a Cantorian one. Starting from El Naschie's space-time we introduce a mathematical approach based on a potential to describe the interaction system-support. We study some relevant force fields on Cantorian space and analyze the differences with respect to the analogous case on a continuum in the context of Lagrangian formulation. Here we confirm the idea proposed by the first author in dynamical systems on El Naschie's o (∞) Cantorian space-time that a Cantorian space could explain some relevant stochastic and quantum processes, if the space acts as an harmonic oscillating support, such as that found in Nature. This means that a quantum process could sometimes be explained as a classical one, but on a nondifferential and discontinuous support. We consider the validity of this point of view, that in principle could be more realistic, because it describes the real nature of matter and space. These do not exist in Euclidean space or curved Riemanian space-time, but in a Cantorian one. The consequence of this point of view could be extended in many fields such as biomathematics, structural engineering, physics, astronomy, biology and so on

Tunneling time in space fractional quantum mechanics

Science.gov (United States)

Hasan, Mohammad; Mandal, Bhabani Prasad

2018-02-01

We calculate the time taken by a wave packet to travel through a classically forbidden region of space in space fractional quantum mechanics. We obtain the close form expression of tunneling time from a rectangular barrier by stationary phase method. We show that tunneling time depends upon the width b of the barrier for b → ∞ and therefore Hartman effect doesn't exist in space fractional quantum mechanics. Interestingly we found that the tunneling time monotonically reduces with increasing b. The tunneling time is smaller in space fractional quantum mechanics as compared to the case of standard quantum mechanics. We recover the Hartman effect of standard quantum mechanics as a special case of space fractional quantum mechanics.

Finiteness principle and the concept of space-time

International Nuclear Information System (INIS)

Tati, T.

1984-01-01

It is shown that the non-space-time description can be given by a system of axioms under the postulate of a certain number of pre-supposed physical concepts in which space-time is not included. It is found that space-time is a compound concept of presupposed concepts of non-space-time description connected by an additional condition called 'space-time condition'. (L.C.) [pt

Embedding a State Space Model Into a Markov Decision Process

DEFF Research Database (Denmark)

Nielsen, Lars Relund; Jørgensen, Erik; Højsgaard, Søren

2011-01-01

In agriculture Markov decision processes (MDPs) with finite state and action space are often used to model sequential decision making over time. For instance, states in the process represent possible levels of traits of the animal and transition probabilities are based on biological models...

The European Person Equivalent: Measuring the personal environmental space

DEFF Research Database (Denmark)

Hauschild, Michael Zwicky; Wenzel, Henrik

2001-01-01

The European person equivalent (PE) is a quantification of the environmental impact caused annually by the activities of an average European. It comprises contributions to all the major environmental impacts from global to local as well as our consumption of resources. Similarly, the targeted...... European person equivalent is a quantification of the average person’s environmental impact in a near future according to the current politically set environmental targets. In addition to expressing the current societal priorities in pollution reduction, the targeted PE expresses the environmental space...... available to all of us according to the current environmental policy. Both concepts were developed in the mid-nineties for use in life cycle impact assessment to help comparisons across different environmental impact categories. Since then they have shown their value as a pedagogic tool in the presentation...

Next Steps Toward Understanding Human Habitation of Space: Environmental Impacts and Mechanisms

Science.gov (United States)

Globus, Ruth

2016-01-01

Entry into low earth orbit and beyond causes profound shifts in environmental conditions that have the potential to influence human productivity, long term health, and even survival. We now have evidence that microgravity, radiation and/or confinement in space can lead to demonstrably detrimental changes in the cardiovascular (e.g. vessel function, orthostatic intolerance), musculoskeletal (muscle atrophy, bone loss) and nervous (eye, neurovestibular) systems of astronauts. Because of both the limited number of astronauts who have flown (especially females) and the high degree of individual variability in the human population, important unanswered questions about responses to the space environment remain: What are the sex differences with respect to specific physiological systems? Are the responses age-dependent and/or reversible after return to Earth? Do observed detrimental changes that resemble accelerated aging progress continuously over time or plateau? What are the mechanisms of the biological responses? Answering these important questions certainly demands a multi-pronged approach, and the study of multicellular model organisms (such as rodents and flies) already has provided opportunities for exploring those questions in some detail. Recent long duration spaceflight experiments with rodents show that mice in space provide a mammalian model that uniquely combines the influence of reduced gravitational loading with increased physical activity. In addition, multiple investigators have shown that ground-based models that simulate aspects of spaceflight (including rodent hind limb unloading to mimic weightlessness and exposure to ionizing radiation), cause various transient and persistent detrimental consequences in multiple physiological systems. In general, we have found that adverse skeletal effects of simulated weightlessness and space radiation when combined, can be quantitatively, if not qualitatively, different from the influence of each environmental

Causal boundary for stably causal space-times

International Nuclear Information System (INIS)

Racz, I.

1987-12-01

The usual boundary constructions for space-times often yield an unsatisfactory boundary set. This problem is reviewed and a new solution is proposed. An explicit identification rule is given on the set of the ideal points of the space-time. This construction leads to a satisfactory boundary point set structure for stably causal space-times. The topological properties of the resulting causal boundary construction are examined. For the stably causal space-times each causal curve has a unique endpoint on the boundary set according to the extended Alexandrov topology. The extension of the space-time through the boundary is discussed. To describe the singularities the defined boundary sets have to be separated into two disjoint sets. (D.Gy.) 8 refs

Stochastic quantization of geometrodynamic curved space-time

International Nuclear Information System (INIS)

Prugovecki, E.

1981-01-01

It is proposed that quantum rather than classical test particles be used in recent operational definitions of space-time. In the resulting quantum space-time the role of test particle trajectories is taken over by propagators. The introduced co-ordinate values are stochastic rather than deterministic, the afore-mentioned propagators providing probability amplitudes describing fluctuations of measured co-ordinates around their mean values. It is shown that, if a geometrodynamic point of view based on 3 + 1 foliations of space-time is adopted, self-consistent families of propagators for quantum test particles in free fall can be constructed. The resulting formalism for quantum space-time is outlined and the quantization of spatially flat Robertson-Walker space-times is provided as an illustration. (author)

State Space Methods for Timed Petri Nets

DEFF Research Database (Denmark)

Christensen, Søren; Jensen, Kurt; Mailund, Thomas

2001-01-01

it possible to condense the usually infinite state space of a timed Petri net into a finite condensed state space without loosing analysis power. The second method supports on-the-fly verification of certain safety properties of timed systems. We discuss the application of the two methods in a number......We present two recently developed state space methods for timed Petri nets. The two methods reconciles state space methods and time concepts based on the introduction of a global clock and associating time stamps to tokens. The first method is based on an equivalence relation on states which makes...

The equivalence of perfect fluid space-times and viscous magnetohydrodynamic space-times in general relativity

International Nuclear Information System (INIS)

Tupper, B.O.J.

1983-01-01

The work of a previous article is extended to show that space-times which are the exact solutions of the field equations for a perfect fluid also may be exact solutions of the field equations for a viscous magnetohydrodynamic fluid. Conditions are found for this equivalence to exist and viscous magnetohydrodynamic solutions are found for a number of known perfect fluid space-times. (author)

The Canadian environmental assessment process: current process, expected reforms, and implications for the nuclear industry

International Nuclear Information System (INIS)

Connelly, R.G.

1994-01-01

The Environmental Assessment and Review Process Guidelines Order (EARP) was the Canadian federal law governing environmental assessment of projects. EARP had been subject to misinterpretation, had been significantly modified in different directions as a result of numerous court cases, and no longer accurately reflected government policy. Parliament therefore passed the Canadian Environmental Assessment Act (CEAA), which received Royal Assent in 1992, but had still not been proclaimed at the time of the conference, pending a review of draft regulations. CEAA will speed up stalled projects, particularly in the Saskatchewan uranium mining industry, by removing uncertainty and by permitting more focussed, flexible, and consistent public reviews; it defines what kind of government projects require approval; it provides for integration of environmental concerns into federal decision making, e.g. by the AECB; it will allow less expensive and more timely environmental assessments

Pseudo-Newtonian Equations for Evolution of Particles and Fluids in Stationary Space-times

Energy Technology Data Exchange (ETDEWEB)

Witzany, Vojtěch; Lämmerzahl, Claus, E-mail: vojtech.witzany@zarm.uni-bremen.de, E-mail: claus.laemmerzahl@zarm.uni-bremen.de [ZARM, Universität Bremen, Am Fallturm, D-28359 Bremen (Germany)

2017-06-01

Pseudo-Newtonian potentials are a tool often used in theoretical astrophysics to capture some key features of a black hole space-time in a Newtonian framework. As a result, one can use Newtonian numerical codes, and Newtonian formalism, in general, in an effective description of important astrophysical processes such as accretion onto black holes. In this paper, we develop a general pseudo-Newtonian formalism, which pertains to the motion of particles, light, and fluids in stationary space-times. In return, we are able to assess the applicability of the pseudo-Newtonian scheme. The simplest and most elegant formulas are obtained in space-times without gravitomagnetic effects, such as the Schwarzschild rather than the Kerr space-time; the quantitative errors are smallest for motion with low binding energy. Included is a ready-to-use set of fluid equations in Schwarzschild space-time in Cartesian and radial coordinates.

A vision for environmentally conscious plutonium processing

International Nuclear Information System (INIS)

Avens, L.R.; Eller, P.G.; Christensen, D.C.; Miller, W.L.

1998-01-01

Regardless of individual technical and political opinions about the uses of plutonium, it is virtually certain that plutonium processing will continue on a significant global scale for many decades for the purposes of national defense, nuclear power and remediation. An unavoidable aspect of plutonium processing is that radioactive contaminated gas, liquid, and solid streams are generated. These streams need to be handled in a manner that is not only in full compliance with today's laws,but also will be considered environmentally and economically responsible now and in the future. In this regard, it is indeed ironic that the multibillion dollar and multidecade radioactive cleanup mortgage that the US Department of Energy (and its Russian counterpart) now owns resulted from waste management practices that were at the time in full legal compliance. The theme of this paper is that recent dramatic advances in actinide science and technology now make it possible to drastically minimize or even eliminate the problematic waste streams of traditional plutonium processing operations. Advanced technology thereby provides the means to avoid passing on to our children and grandchildren significant environmental and economic legacies that traditional processing inevitably produces. This paper will describe such a vision for plutonium processing that could be implemented fully within five years at a facility such as the Los Alamos Plutonium Facility (TA55). As a significant bonus, even on this short time scale, the initial technology investment is handsomely returned in avoided waste management costs

Kennedy Space Center Timing and Countdown Interface to Kennedy Ground Control Subsystem

Science.gov (United States)

Olsen, James C.

2015-01-01

Kennedy Ground Control System (KGCS) engineers at the National Aeronautics and Space Administration (NASA) Kennedy Space Center (KSC) are developing a time-tagging process to enable reconstruction of the events during a launch countdown. Such a process can be useful in the case of anomalies or other situations where it is necessary to know the exact time an event occurred. It is thus critical for the timing information to be accurate. KGCS will synchronize all items with Coordinated Universal Time (UTC) obtained from the Timing and Countdown (T&CD) organization. Network Time Protocol (NTP) is the protocol currently in place for synchronizing UTC. However, NTP has a peak error that is too high for today's standards. Precision Time Protocol (PTP) is a newer protocol with a much smaller peak error. The focus of this project has been to implement a PTP solution on the network to increase timing accuracy while introducing and configuring the implementation of a firewall between T&CD and the KGCS network.

Proceedings of the Space Shuttle Environmental Assessment Workshop on Stratospheric Effects

Science.gov (United States)

Potter, A. E. (Compiler)

1977-01-01

Various aspects of the potential environmental impact of space shuttle exhaust are explored. Topics include: (1) increased ultraviolet radiation levels in the biosphere due to destruction of atmospheric ozone; (2) climatic changes due to aerosol particles affecting the planetary albedo; (3) space shuttle propellants (including alternate formulations); and (4) measurement of space shuttle exhaust products.

Time-space limitations of Nernst-Planck equations

International Nuclear Information System (INIS)

Pellicer, J.; Aguilera, V.M.; Mafe, S.

1988-01-01

The nature and applicability of Nernst-Planck and Poisson equations are considered, concerning the problem of electrolyte transport in non-homogeneous solutions. Some approximations related to the model of transport are discussed, specially those referring to the electrodynamical aspects. Thus, the connection between the classical electrostatics approximations and the time-space limitations of the model is shown. A detailed analysis leads to conclude that some of the aspects of the charge separation process have not been completely understood. (Author)

Bibliography of the space processing program. Volume 1: A compilation through June 1974, Parts 1 and 2. [space manufacturing/spacecraft construction materials - aerospace environments

Science.gov (United States)

Shoultz, M. B.; Mcclurken, E. W., Jr.

1975-01-01

A compilation of NASA research efforts in the area of space environmental effects on materials and processes is presented. Topics considered are: (1) fluid mechanics and heat transfer; (2) crystal growth and containerless melts; (3) acoustics; (4) glass and ceramics; (5) electrophoresis; (6) welding; and (7) exobiology.

Improved Methods for Production Manufacturing Processes in Environmentally Benign Manufacturing

Directory of Open Access Journals (Sweden)

Yan-Yan Wang

2011-09-01

Full Text Available How to design a production process with low carbon emissions and low environmental impact as well as high manufacturing performance is a key factor in the success of low-carbon production. It is important to address concerns about climate change for the large carbon emission source manufacturing industries because of their high energy consumption and environmental impact during the manufacturing stage of the production life cycle. In this paper, methodology for determining a production process is developed. This methodology integrates process determination from three different levels: new production processing, selected production processing and batch production processing. This approach is taken within a manufacturing enterprise based on prior research. The methodology is aimed at providing decision support for implementing Environmentally Benign Manufacturing (EBM and low-carbon production to improve the environmental performance of the manufacturing industry. At the first level, a decision-making model for new production processes based on the Genetic Simulated Annealing Algorithm (GSAA is presented. The decision-making model considers not only the traditional factors, such as time, quality and cost, but also energy and resource consumption and environmental impact, which are different from the traditional methods. At the second level, a methodology is developed based on an IPO (Input-Process-Output model that integrates assessments of resource consumption and environmental impact in terms of a materials balance principle for batch production processes. At the third level, based on the above two levels, a method for determining production processes that focus on low-carbon production is developed based on case-based reasoning, expert systems and feature technology for designing the process flow of a new component. Through the above three levels, a method for determining the production process to identify, quantify, assess, and optimize the

Temperature and entropy of Schwarzschild-de Sitter space-time

International Nuclear Information System (INIS)

Shankaranarayanan, S.

2003-01-01

In the light of recent interest in quantum gravity in de Sitter space, we investigate semiclassical aspects of four-dimensional Schwarzschild-de Sitter space-time using the method of complex paths. The standard semiclassical techniques (such as Bogoliubov coefficients and Euclidean field theory) have been useful to study quantum effects in space-times with single horizons; however, none of these approaches seem to work for Schwarzschild-de Sitter space-time or, in general, for space-times with multiple horizons. We extend the method of complex paths to space-times with multiple horizons and obtain the spectrum of particles produced in these space-times. We show that the temperature of radiation in these space-times is proportional to the effective surface gravity--the inverse harmonic sum of surface gravity of each horizon. For the Schwarzschild-de Sitter space-time, we apply the method of complex paths to three different coordinate systems--spherically symmetric, Painleve, and Lemaitre. We show that the equilibrium temperature in Schwarzschild-de Sitter space-time is the harmonic mean of cosmological and event horizon temperatures. We obtain Bogoliubov coefficients for space-times with multiple horizons by analyzing the mode functions of the quantum fields near the horizons. We propose a new definition of entropy for space-times with multiple horizons, analogous to the entropic definition for space-times with a single horizon. We define entropy for these space-times to be inversely proportional to the square of the effective surface gravity. We show that this definition of entropy for Schwarzschild-de Sitter space-time satisfies the D-bound conjecture

Environmental stressors during space flight: potential effects on body temperature

Science.gov (United States)

Jauchem, J. R.

1988-01-01

1. Organisms may be affected by many environmental factors during space flight, e.g., acceleration, weightlessness, decreased pressure, changes in oxygen tension, radiofrequency radiation and vibration. 2. Previous studies of change in body temperature--one response to these environmental factors--are reviewed. 3. Conditions leading to heat stress and hypothermia are discussed.

Processing and inversion of commercial helicopter time-domain electromagnetic data for environmental assessments and geologic and hydrologic mapping

DEFF Research Database (Denmark)

J.E., Podgorski; Auken, Esben; Schamper, Cyril Noel Clarence

2013-01-01

Helicopter time-domain electromagnetic (HTEM) surveying has historically been used for mineral exploration, but over the past decade it has started to be used in environmental assessments and geologic and hydrologic mapping. Such surveying is a cost-effective means of rapidly acquiring densely......%-23%, and the artificial lineations were practically eliminated. Our processing and inversion strategy is entirely general, such that with minor system-specific modifications it could be applied to any HTEM data set, including those recorded many years ago. © 2013 Society of Exploration Geophysicists....

Environmental management of business processes

Directory of Open Access Journals (Sweden)

Vesna Čančer

2000-01-01

Full Text Available Since the decision-makers in enterprises will accept the goals of environmental management only if they are motivated enough, comprehensible and useful tools should be generated to support environmentally oriented business decision-making. For that reason, a general optimisation model of the multiphase business process is presented in this paper. This model includes the possibilities for an integrated approach to environmental protection so that it can be applied as a scenario by the business process simulation for the evaluation of environmentally oriented business decisions on business performance. Furthermore, development and application possibilities of the presented model are introduced. Some measures of resource efficiency are developed using the presented optimisation model.

On black holes, space-time foam and the nature of time in string theory

International Nuclear Information System (INIS)

Mavromatos, N.E.; Grenoble-1 Univ., 74 - Annecy

1993-04-01

It is shown that the light particles in string theory obey an effective quantum mechanics modified by the inclusion of a quantum-gravitational friction term, induced by unavoidable couplings to unobserved massive string states in the space-time foam. This term is related to the W-symmetries that couple light particles to massive solitonic string states in black hole backgrounds, and has a formal similarity to simple models of environmental quantum friction. All properties follow from a definition of target-time as a Renormalization Group scale parameter and the associated (generic) properties of the renormalization group flow. Some experimental consequences, concerning CPT violation detectable in systems that are generally considered as sensitive probes of quantum mechanics (e.g. neutral kaons), are briefly discussed. (author). 52 refs., 1 fig

Consensus shaping and safe space public participation processes

Energy Technology Data Exchange (ETDEWEB)

Andersson, Kjell [Karita Research AB, Taeaby (Sweden)

2015-07-01

Stakeholder involvement and public participation is recognized as a necessary part of nuclear waste management. It is possible to see three driving forces behind this development: (1) a deliberative movement with its roots in the 1960s leftish movement (a philosophical argument), (2) the need for public acceptance of proposed solutions (a practical argument), and (3) the need for awareness and clarity before crucial decisions are made (a practical and democratic argument). Depending on which driving force dominates an initiative for public participation, the initiator is likely to prefer certain public participation processes before others. The initiator has to select among a large number of processes already having been implemented or design a new one tailored for the specific situation. The process choice is crucial for which stakeholders are able to join and which goals can be reached. Much of the debate about public participation has referred to the ''Arnstein ladder'' (Arnstein, 1969) or its modernized versions, such as the participation ladder used in the IPPA Project (Richardson et.al. 2011) building on work by the Netherlands Environmental Assessment Agency (MNP, 2008). The various forms of ladders have in common an increasing level of ambition for participation from low to high. The higher up on the ladder, the better it is often anticipated. However, with this should follow more responsibility and accountability of all participants, which in practice is often lacking. There are also practical problems in using the ladder to map public participation processes. For example the step 'collaboration' is ambiguous as it can mean different things. In the RISCOM Process, participants collaborate to improve clarity and awareness but not for finding common solutions. Therefore, the RISCOM Process (Vojtechova, 2009) does not fit into the ladder structure. To avoid these and other problems it is suggested to use three basic approaches to

Consensus shaping and safe space public participation processes

International Nuclear Information System (INIS)

Andersson, Kjell

2015-01-01

Stakeholder involvement and public participation is recognized as a necessary part of nuclear waste management. It is possible to see three driving forces behind this development: (1) a deliberative movement with its roots in the 1960s leftish movement (a philosophical argument), (2) the need for public acceptance of proposed solutions (a practical argument), and (3) the need for awareness and clarity before crucial decisions are made (a practical and democratic argument). Depending on which driving force dominates an initiative for public participation, the initiator is likely to prefer certain public participation processes before others. The initiator has to select among a large number of processes already having been implemented or design a new one tailored for the specific situation. The process choice is crucial for which stakeholders are able to join and which goals can be reached. Much of the debate about public participation has referred to the ''Arnstein ladder'' (Arnstein, 1969) or its modernized versions, such as the participation ladder used in the IPPA Project (Richardson et.al. 2011) building on work by the Netherlands Environmental Assessment Agency (MNP, 2008). The various forms of ladders have in common an increasing level of ambition for participation from low to high. The higher up on the ladder, the better it is often anticipated. However, with this should follow more responsibility and accountability of all participants, which in practice is often lacking. There are also practical problems in using the ladder to map public participation processes. For example the step 'collaboration' is ambiguous as it can mean different things. In the RISCOM Process, participants collaborate to improve clarity and awareness but not for finding common solutions. Therefore, the RISCOM Process (Vojtechova, 2009) does not fit into the ladder structure. To avoid these and other problems it is suggested to use three basic approaches to

Space-time design of the public city

CERN Document Server

Thomaier, Susanne; Könecke, Benjamin; Zedda, Roberto; Stabilini, Stefano

2013-01-01

Time has become an increasingly important topic in urban studies and urban planning. The spatial-temporal interplay is not only of relevance for the theory of urban development and urban politics, but also for urban planning and governance. The space-time approach focuses on the human being with its various habits and routines in the city. Understanding and taking those habits into account in urban planning and public policies offers a new way to improve the quality of life in our cities. Adapting the supply and accessibility of public spaces and services to the inhabitants’ space-time needs calls for an integrated approach to the physical design of urban space and to the organization of cities. In the last two decades the body of practical and theoretical work on urban space-time topics has grown substantially. The book offers a state of the art overview of the theoretical reasoning, the development of new analytical tools, and practical experience of the space-time design of public cities in major Europea...

Sampling and Timing: A Task for the Environmetal Process

NARCIS (Netherlands)

Hilderink, G.H.; Broenink, Johannes F.

2003-01-01

Sampling and timing is considered a responsibility of the environment of controller software. In this paper we will illustrate a concept whereby an environmental process and multi-way events play an important role in applying timing for untimed CSP software architectures. We use this timing concept

The space-time of dark-matter

International Nuclear Information System (INIS)

Dey, Dipanjan

2015-01-01

Dark-matter is a hypothetical matter which can't be seen but around 27% of our universe is made of it. Its distribution, evolution from early stage of our universe to present stage, its particle constituents all these are great unsolved mysteries of modern Cosmology and Astrophysics. In this talk I will introduce a special kind of space-time which is known as Bertrand Space-time (BST). I will show this space-time interestingly shows some dark-matter properties like- flat velocity curve, density profile of Dark-matter, total mass of Dark matter-halo, gravitational lensing etc, for that reason we consider BST is seeded by Dark-matter or it is a space-time of Dark-matter. At last I will show using modified gravity formalism the behaviour of the equation of state parameter of Dark-matter and the behaviour of the Newton's gravitational constant in the vicinity of the singularity. (author)

Different time concepts in the classroom. From monologue to dialogue: space

Directory of Open Access Journals (Sweden)

Leonor Sáez Méndez

2012-12-01

Full Text Available This paper explores, taking as its starting point cognitive variables, the essential function which affective variables have in the teaching of foreign languages. The conceptual transposition a reorientation required to acquire a second language involves distinguishing different philosophical concepts about space and time. From the 1970s and on, the linguistic requirements of teaching a language have taken a Kantian turn. Together with the principles of pragmatics and interculturality, it is important to work with concepts such as perception, disposition, motivation, intuition, level of empathy, and fear. Bearing in mind that these are complex factors which have a great impact on the process of immersion in a foreign language, it is worth asking if they are just temporal. The actual learning process, involving self-study, requires additional support to focus the learner’s resources and encourage them to immerse themselves in and identify with the culture associated with the language they are learning. These areas are in the critical period, especially in the post-Kantian critical, empirical thresholds that shape our thinking and guide the choice of exercises. Our study aims 1 to refl ect on the diff erent conceptions of time (as inner meaning, cognitive time underlying foreign language teaching; 2 to explore whether is it possible to develop a methodology based just on time, therefore leaving, space to one side or, in contrast, whether it is space which rules over time in the process of foreign language acquisition.

Evaluation of environmental impacts of cellulosic ethanol using life cycle assessment with technological advances over time

International Nuclear Information System (INIS)

Pawelzik, Paul F.; Zhang, Qiong

2012-01-01

Life Cycle Assessment (LCA) has been used in quantifying the environmental impacts of materials, processes, products, or systems across their entire lifespan from creation to disposal. To evaluate the environmental impact of advancing technology, Life Cycle Assessment with Technological Advances over Time (LCA-TAT) incorporates technology improvements within the traditional LCA framework. In this paper, the LCA-TAT is applied to quantify the environmental impacts of ethanol production using cellulosic biomass as a feedstock through the simultaneous saccharification and co-fermentation (SSCF) process as it improves over time. The data for the SSCF process are taken from the Aspen Plus ® simulation developed by the National Renewable Energy Lab (NREL). The Environmental Fate and Risk Assessment Tool (EFRAT) is used to calculate the fugitive emissions and SimaPro 7.1 software is used to quantify the environmental impacts of processes. The impact indicators of the processes are calculated using the Eco-indicator 95 method; impact categories analyzed include ozone layer depletion, heavy metals, carcinogens, summer smog, winter smog, pesticides, greenhouse effect, acidification, and eutrophication. Based on the LCA-TAT results, it is found that removal of the continuous ion exchange step within the pretreatment area increases the environmental impact of the process. The main contributor to the increase in the environmental impact of the process is the heavy metal indicator. In addition, a sensitivity analysis is performed to identify major inputs and outputs that affect environmental impacts of the overall process. Based on this analysis it is observed that an increase in waste production and acid use have the greatest effect on the environmental impacts of the SSCF process. Comparing economic analysis with projected technological advances performed by NREL, the improvement in environmental impact was not matched by a concomitant improvement in economic performance. In

Model-based testing for space-time interaction using point processes: An application to psychiatric hospital admissions in an urban area.

Science.gov (United States)

Meyer, Sebastian; Warnke, Ingeborg; Rössler, Wulf; Held, Leonhard

2016-05-01

Spatio-temporal interaction is inherent to cases of infectious diseases and occurrences of earthquakes, whereas the spread of other events, such as cancer or crime, is less evident. Statistical significance tests of space-time clustering usually assess the correlation between the spatial and temporal (transformed) distances of the events. Although appealing through simplicity, these classical tests do not adjust for the underlying population nor can they account for a distance decay of interaction. We propose to use the framework of an endemic-epidemic point process model to jointly estimate a background event rate explained by seasonal and areal characteristics, as well as a superposed epidemic component representing the hypothesis of interest. We illustrate this new model-based test for space-time interaction by analysing psychiatric inpatient admissions in Zurich, Switzerland (2007-2012). Several socio-economic factors were found to be associated with the admission rate, but there was no evidence of general clustering of the cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Practical reporting times for environmental samples

International Nuclear Information System (INIS)

Bayne, C.K.; Schmoyer, D.D.; Jenkins, R.A.

1993-02-01

Preanalytical holding times for environmental samples are specified because chemical and physical characteristics may change between sampling and chemical analysis. For example, the Federal Register prescribes a preanalytical holding time of 14 days for volatile organic compounds in soil stored at 4 degrees C. The American Society for Testing Materials (ASTM) uses a more technical definition that the preanalytical holding time is the day when the analyte concentration for an environmental sample falls below the lower 99% confidence interval on the analyte concentration at day zero. This study reviews various holding time definitions and suggest a new preanalytical holding time approach using acceptable error rates for measuring an environmental analyte. This practical reporting time (PRT) approach has been applied to nineteen volatile organic compounds and four explosives in three environmental soil samples. A PRT nomograph of error rates has been developed to estimate the consequences of missing a preanalytical holding time. This nomograph can be applied to a large class of analytes with concentrations that decay linearly or exponentially with time regardless of sample matrices and storage conditions

Practical reporting times for environmental samples

Energy Technology Data Exchange (ETDEWEB)

Bayne, C.K.; Schmoyer, D.D.; Jenkins, R.A.

1993-02-01

Preanalytical holding times for environmental samples are specified because chemical and physical characteristics may change between sampling and chemical analysis. For example, the Federal Register prescribes a preanalytical holding time of 14 days for volatile organic compounds in soil stored at 4{degrees}C. The American Society for Testing Materials (ASTM) uses a more technical definition that the preanalytical holding time is the day when the analyte concentration for an environmental sample falls below the lower 99% confidence interval on the analyte concentration at day zero. This study reviews various holding time definitions and suggest a new preanalytical holding time approach using acceptable error rates for measuring an environmental analyte. This practical reporting time (PRT) approach has been applied to nineteen volatile organic compounds and four explosives in three environmental soil samples. A PRT nomograph of error rates has been developed to estimate the consequences of missing a preanalytical holding time. This nomograph can be applied to a large class of analytes with concentrations that decay linearly or exponentially with time regardless of sample matrices and storage conditions.

From Discrete Space-Time to Minkowski Space: Basic Mechanisms, Methods and Perspectives

Science.gov (United States)

Finster, Felix

This survey article reviews recent results on fermion systems in discrete space-time and corresponding systems in Minkowski space. After a basic introduction to the discrete setting, we explain a mechanism of spontaneous symmetry breaking which leads to the emergence of a discrete causal structure. As methods to study the transition between discrete space-time and Minkowski space, we describe a lattice model for a static and isotropic space-time, outline the analysis of regularization tails of vacuum Dirac sea configurations, and introduce a Lorentz invariant action for the masses of the Dirac seas. We mention the method of the continuum limit, which allows to analyze interacting systems. Open problems are discussed.

Quantum space-time: a review

International Nuclear Information System (INIS)

Namsrai, K.

1988-01-01

The review presents systematically the results of studies which develop an idea of quantum properties of space-time in the microworld or near exotic objects (black holes, magnetic monopoles and others). On the basis of this idea motion equations of nonrelativistic and relativistic particles are studied. It is shown that introducing concept of quantum space-time at small distances (or near superdense matter) leads to an additional force giving rise to appearance of spiral-like behaviour of a particle along its classical trajectory. Given method is generalized to nonrelativistic quantum mechanics and to motion of a particle in gravitational force. In the latter case, there appears to be an antigravitational effect in the motion of a particle leading to different value of free-fall time (at least for gravitational force of exotic objects) for particles with different masses. Gravitational consequences of quantum space-time and tensor structures of physical quantities are investigated in detail. From experimental data on testing relativity and anisotropy of inertia estimation L ≤ 10 -22 cm on the value of the fundamental length is obtained. (author)

A Note on the Problem of Proper Time in Weyl Space-Time

Science.gov (United States)

Avalos, R.; Dahia, F.; Romero, C.

2018-02-01

We discuss the question of whether or not a general Weyl structure is a suitable mathematical model of space-time. This is an issue that has been in debate since Weyl formulated his unified field theory for the first time. We do not present the discussion from the point of view of a particular unification theory, but instead from a more general standpoint, in which the viability of such a structure as a model of space-time is investigated. Our starting point is the well known axiomatic approach to space-time given by Elhers, Pirani and Schild (EPS). In this framework, we carry out an exhaustive analysis of what is required for a consistent definition for proper time and show that such a definition leads to the prediction of the so-called "second clock effect". We take the view that if, based on experience, we were to reject space-time models predicting this effect, this could be incorporated as the last axiom in the EPS approach. Finally, we provide a proof that, in this case, we are led to a Weyl integrable space-time as the most general structure that would be suitable to model space-time.

An environmental testing facility for Space Station Freedom power management and distribution hardware

Science.gov (United States)

Jackola, Arthur S.; Hartjen, Gary L.

1992-01-01

The plans for a new test facility, including new environmental test systems, which are presently under construction, and the major environmental Test Support Equipment (TSE) used therein are addressed. This all-new Rocketdyne facility will perform space simulation environmental tests on Power Management and Distribution (PMAD) hardware to Space Station Freedom (SSF) at the Engineering Model, Qualification Model, and Flight Model levels of fidelity. Testing will include Random Vibration in three axes - Thermal Vacuum, Thermal Cycling and Thermal Burn-in - as well as numerous electrical functional tests. The facility is designed to support a relatively high throughput of hardware under test, while maintaining the high standards required for a man-rated space program.

Axiomatics of uniform space-time models

International Nuclear Information System (INIS)

Levichev, A.V.

1983-01-01

The mathematical statement of space-time axiomatics of the special theory of relativity is given; it postulates that the space-time M is the binding single boundary Hausedorf local-compact four-dimensional topological space with the given order. The theorem is proved: if the invariant order in the four-dimensional group M is given by the semi-group P, which contingency K contains inner points , then M is commutative. The analogous theorem is correct for the group of two and three dimensionalities

Black Hole Space-time In Dark Matter Halo

OpenAIRE

Xu, Zhaoyi; Hou, Xian; Gong, Xiaobo; Wang, Jiancheng

2018-01-01

For the first time, we obtain the analytical form of black hole space-time metric in dark matter halo for the stationary situation. Using the relation between the rotation velocity (in the equatorial plane) and the spherical symmetric space-time metric coefficient, we obtain the space-time metric for pure dark matter. By considering the dark matter halo in spherical symmetric space-time as part of the energy-momentum tensors in the Einstein field equation, we then obtain the spherical symmetr...

Materials, processes, and environmental engineering network

Science.gov (United States)

White, Margo M.

1993-01-01

The Materials, Processes, and Environmental Engineering Network (MPEEN) was developed as a central holding facility for materials testing information generated by the Materials and Processes Laboratory. It contains information from other NASA centers and outside agencies, and also includes the NASA Environmental Information System (NEIS) and Failure Analysis Information System (FAIS) data. Environmental replacement materials information is a newly developed focus of MPEEN. This database is the NASA Environmental Information System, NEIS, which is accessible through MPEEN. Environmental concerns are addressed regarding materials identified by the NASA Operational Environment Team, NOET, to be hazardous to the environment. An environmental replacement technology database is contained within NEIS. Environmental concerns about materials are identified by NOET, and control or replacement strategies are formed. This database also contains the usage and performance characteristics of these hazardous materials. In addition to addressing environmental concerns, MPEEN contains one of the largest materials databases in the world. Over 600 users access this network on a daily basis. There is information available on failure analysis, metals and nonmetals testing, materials properties, standard and commercial parts, foreign alloy cross-reference, Long Duration Exposure Facility (LDEF) data, and Materials and Processes Selection List data.

Environmental Science: Processes & Impacts in 2018.

Science.gov (United States)

2018-02-21

2017 was another successful year for Environmental Science: Processes & Impacts (ESPI); it saw the expansion of our Editorial team and publication of two excellent Themed Issues, all while maintaining our commitment to provide our authors with exceptional customer service and fast times to publication. Through this Editorial, we wish to reflect upon some of the highlights from 2017 and also take this opportunity to reveal further new additions to the ESPI team and our plans for 2018.

Application of hierarchical clustering method to classify of space-time rainfall patterns

Science.gov (United States)

Yu, Hwa-Lung; Chang, Tu-Je

2010-05-01

Understanding the local precipitation patterns is essential to the water resources management and flooding mitigation. The precipitation patterns can vary in space and time depending upon the factors from different spatial scales such as local topological changes and macroscopic atmospheric circulation. The spatiotemporal variation of precipitation in Taiwan is significant due to its complex terrain and its location at west pacific and subtropical area, where is the boundary between the pacific ocean and Asia continent with the complex interactions among the climatic processes. This study characterizes local-scale precipitation patterns by classifying the historical space-time precipitation records. We applied the hierarchical ascending clustering method to analyze the precipitation records from 1960 to 2008 at the six rainfall stations located in Lan-yang catchment at the northeast of the island. Our results identify the four primary space-time precipitation types which may result from distinct driving forces from the changes of atmospheric variables and topology at different space-time scales. This study also presents an important application of the statistical downscaling to combine large-scale upper-air circulation with local space-time precipitation patterns.

Relativistic positioning in Schwarzschild space-time

International Nuclear Information System (INIS)

Puchades, Neus; Sáez, Diego

2015-01-01

In the Schwarzschild space-time created by an idealized static spherically symmetric Earth, two approaches -based on relativistic positioning- may be used to estimate the user position from the proper times broadcast by four satellites. In the first approach, satellites move in the Schwarzschild space-time and the photons emitted by the satellites follow null geodesics of the Minkowski space-time asymptotic to the Schwarzschild geometry. This assumption leads to positioning errors since the photon world lines are not geodesics of any Minkowski geometry. In the second approach -the most coherent one- satellites and photons move in the Schwarzschild space-time. This approach is a first order one in the dimensionless parameter GM/R (with the speed of light c=1). The two approaches give different inertial coordinates for a given user. The differences are estimated and appropriately represented for users located inside a great region surrounding Earth. The resulting values (errors) are small enough to justify the use of the first approach, which is the simplest and the most manageable one. The satellite evolution mimics that of the GALILEO global navigation satellite system. (paper)

A vision for environmentally conscious plutonium processing

International Nuclear Information System (INIS)

Avens, L.R.; Eller, P.G.; Christensen, D.C.; Miller, W.L.

1998-01-01

Regardless of individual technical and political opinions about the uses of plutonium, it is virtually certain that plutonium processing will continue on a significant global scale for many decades for the purposes of national defense, nuclear power, and remediation. An unavoidable aspect of plutonium processing is that radioactively contaminated gas, liquid, and solid waste streams are generated. These streams need to be handled in a manner that not only is in full compliance with today's laws but also will be considered environmentally and economically responsible now and in the future. In this regard, it is indeed ironic that the multibillion dollar and multidecade radioactive cleanup mortgage that the US Department of Energy (and its Russian counterpart) now owns resulted from waste management practices that were at the time in full legal compliance. It is now abundantly evident that in the long run, these practices have proven to be neither environmentally nor economically sound. Recent dramatic advances in actinide science and technology now make it possible to drastically minimize or even eliminate the problematic waste streams of traditional plutonium processing operations. Advanced technology thereby provides the means to avoid passing on to children and grandchildren significant environmental and economic legacies that traditional processing inevitably produces. The authors describe such a vision for plutonium processing that could be implemented fully within 5 yr at a facility such as the Los Alamos National Laboratory Plutonium Facility (TA55). As a significant bonus, even on this short timescale, the initial technology investment is handsomely returned in avoided waste management costs

Introducing the Dimensional Continuous Space-Time Theory

International Nuclear Information System (INIS)

Martini, Luiz Cesar

2013-01-01

This article is an introduction to a new theory. The name of the theory is justified by the dimensional description of the continuous space-time of the matter, energy and empty space, that gathers all the real things that exists in the universe. The theory presents itself as the consolidation of the classical, quantum and relativity theories. A basic equation that describes the formation of the Universe, relating time, space, matter, energy and movement, is deduced. The four fundamentals physics constants, light speed in empty space, gravitational constant, Boltzmann's constant and Planck's constant and also the fundamentals particles mass, the electrical charges, the energies, the empty space and time are also obtained from this basic equation. This theory provides a new vision of the Big-Bang and how the galaxies, stars, black holes and planets were formed. Based on it, is possible to have a perfect comprehension of the duality between wave-particle, which is an intrinsic characteristic of the matter and energy. It will be possible to comprehend the formation of orbitals and get the equationing of atomics orbits. It presents a singular comprehension of the mass relativity, length and time. It is demonstrated that the continuous space-time is tridimensional, inelastic and temporally instantaneous, eliminating the possibility of spatial fold, slot space, worm hole, time travels and parallel universes. It is shown that many concepts, like dark matter and strong forces, that hypothetically keep the cohesion of the atomics nucleons, are without sense.

Space-time and matter in 'prephysics'

International Nuclear Information System (INIS)

Terazawa, Hidezumi.

1985-05-01

Many fundamental questions concerning the space-time and matter are asked and answered in ''prephysics'', a new line of physics (or philosophy but not metaphysics). They include the following: 1) ''Why is our space-time of 4 dimensions.'', 2) ''What is the ultimate form of matter.'' and 3) ''How was our universe created.''. (author)

On static and radiative space-times

International Nuclear Information System (INIS)

Friedrich, H.

1988-01-01

The conformal constraint equations on space-like hypersurfaces are discussed near points which represent either time-like or spatial infinity for an asymptotically flat solution of Einstein's vacuum field equations. In the case of time-like infinity a certain 'radiativity condition' is derived which must be satisfied by the data at that point. The case of space-like infinity is analysed in detail for static space-times with non-vanishing mass. It is shown that the conformal structure implied here on a slice of constant Killing time, which extends analytically through infinity, satisfies at spatial infinity the radiativity condition. Thus to any static solution exists a certain 'radiative solution' which has a smooth structure at past null infinity and is regular at past time-like infinity. A characterization of these solutions by their 'free data' is given and non-symmetry properties are discussed. (orig.)

Knowledge Base Applications to Adaptive Space-Time Processing, Volume 5: Knowledge-Based Tracker Rule Book

National Research Council Canada - National Science Library

Morgan, Charles

2001-01-01

..., and (2) knowledge of the target's line-of-sight visibility, the competing clutter conditions, and interference at the predicted location so that the optimal radar parameters and space-time adaptive...

The Dirac equation in the Lobachevsky space-time

International Nuclear Information System (INIS)

Paramonov, D.V.; Paramonova, N.N.; Shavokhina, N.S.

2000-01-01

The product of the Lobachevsky space and the time axis is termed the Lobachevsky space-time. The Lobachevsky space is considered as a hyperboloid's sheet in the four-dimensional pseudo-Euclidean space. The Dirac-Fock-Ivanenko equation is reduced to the Dirac equation in two special forms by passing from Lame basis in the Lobachevsky space to the Cartesian basis in the enveloping pseudo-Euclidean space

Earthquakes, public spaces and (the social construction of environmental disasters. The role of public space for risk mitigation and urban redevelopment and the role of environmental disasters for re­ assessing the ‘space of the Public’.

Directory of Open Access Journals (Sweden)

Barbara Pizzo

2014-02-01

Full Text Available This paper stems from long­lasting research dedicated to urban risk reduction through a planning approach. It focuses on public space, proposing an inversion of the usual perspective: instead of considering public spaces for risk mitigation and urban redevelopment, here the imperatives of environmental safety and urban resilience can be instrumental for exploring the meaning and role of the public space from a different, rather compelling point of view. One starting point is the concept of SUM, Strategic Urban Structure (or Framework, from the Italian “Struttura urbana minima”, which has been introduced in order to set out the contents of urban risk reduction in local administration agendas and particularly into ordinary planning processes. The SUM has been conceived both as an analytical and a normative/planning tool. Public spaces are the backbone of both urban structure and of the SUM. From their features, localization, distribution within thesettlement, and their systemic characters, largely depend the capacity of a town to positively react to a seismic event. Six case­studies of small and medium­size historic towns in the Umbria Region (one of the many Italian Regions with a high level of seismic risk, help to understand the complexities and problems related to seismic prevention within historical centres, and the conflicts between conservation of the heritage and the imperatives of environmental safety. In order to overcome possible criticalities identified in a SUM, it is necessary to provide alternatives to its functioning through redundant elements. The concept of redundancy, which is strictly related to that of uncertainty, is very interesting and promising in this field of research.

About the coordinate time for photons in Lifshitz space-times

International Nuclear Information System (INIS)

Villanueva, J.R.; Vasquez, Yerko

2013-01-01

In this paper we studied the behavior of radial photons from the point of view of the coordinate time in (asymptotically) Lifshitz space-times, and we found a generalization to the result reported in previous works by Cruz et al. (Eur. Phys. J. C 73:7, 2013), Olivares et al. (Astrophys. Space Sci. 347:83-89, 2013), and Olivares et al. arXiv:1306.5285. We demonstrate that all asymptotically Lifshitz space-times characterized by a lapse function f(r) which tends to one when r→∞, present the same behavior, in the sense that an external observer will see that photons arrive at spatial infinity in a finite coordinate time. Also, we show that radial photons in the proper system cannot determine the presence of the black hole in the region r + < r<∞, because the proper time as a result is independent of the lapse function f(r). (orig.)

The Space-Time Topography of English Speakers

Science.gov (United States)

Duman, Steve

2016-01-01

English speakers talk and think about Time in terms of physical space. The past is behind us, and the future is in front of us. In this way, we "map" space onto Time. This dissertation addresses the specificity of this physical space, or its topography. Inspired by languages like Yupno (Nunez, et al., 2012) and Bamileke-Dschang (Hyman,…

Space use optimisation and sustainability-environmental comparison of international cases.

Science.gov (United States)

de Wilde, Sebastiaan; van den Dobbelsteen, Andy

2004-11-01

As a follow-up to our first paper in this journal, this paper discusses projects involving intensive and multiple use of space recently completed or still being developed around railway stations in London (Broadgate and Canary Wharf), Paris (Seine Rive Gauche and La Défense) and Amsterdam (Zuidas and Bijlmer). The cases were compared on the basis of spatial, functional and environmental indicators, as treated in our first paper. The environmental performance of each of the cases was determined through comparison with a theoretic reference project for an equal number of users, yet with average West-European urban values for spatial, functional and environmental properties. The case studies revealed that a high floor space index is easily achievable in urban plans, implying efficient use of land and preservation of green area outside the city. For a mono-functional office area it is easier to achieve a high FSI than for a functionally diverse area with, e.g. apartments and shops. Therefore, with respect to a reference functionally equal to the cases, the predominant office character of Canary Wharf, Broadgate and La Défense results in good environmental performance. However, on the basis of a functionally diverse reference, for which monofunctional cases were enlarged with additional area for housing and amenities, the varied areas of Zuidas and Seine Rive Gauche perform best. With respect to average urban plans, the cases achieved environmental improvement of factor 1.5. This performance is restricted by the energy consumption of buildings, which has by far the most influence on the end result. The impact of stacking on the use of building materials and energy consumption of buildings is limited, and specific sustainability measures on the building scale were not involved in the calculations. The environmental benefits of intensive and multiple use of space are mainly demonstrated by the great improvement factors for the green area preserved and transport fuel

Statistical geometry and space-time

International Nuclear Information System (INIS)

Grauert, H.

1976-01-01

In this paper I try to construct a mathematical tool by which the full structure of Lorentz geometry to space time can be given, but beyond that the background - to speak pictorially - the subsoil for electromagnetic and matter waves, too. The tool could be useful to describe the connections between various particles, electromagnetism and gravity and to compute observables which were not theoretically related, up to now. Moreover, the tool is simpler than the Riemann tensor: it consists just of a set S of line segments in space time, briefly speaking. (orig.) [de

Spinor Field Nonlinearity and Space-Time Geometry

Science.gov (United States)

Saha, Bijan

2018-03-01

Within the scope of Bianchi type VI,VI0,V, III, I, LRSBI and FRW cosmological models we have studied the role of nonlinear spinor field on the evolution of the Universe and the spinor field itself. It was found that due to the presence of non-trivial non-diagonal components of the energy-momentum tensor of the spinor field in the anisotropic space-time, there occur some severe restrictions both on the metric functions and on the components of the spinor field. In this report we have considered a polynomial nonlinearity which is a function of invariants constructed from the bilinear spinor forms. It is found that in case of a Bianchi type-VI space-time, depending of the sign of self-coupling constants, the model allows either late time acceleration or oscillatory mode of evolution. In case of a Bianchi VI 0 type space-time due to the specific behavior of the spinor field we have two different scenarios. In one case the invariants constructed from bilinear spinor forms become trivial, thus giving rise to a massless and linear spinor field Lagrangian. This case is equivalent to the vacuum solution of the Bianchi VI 0 type space-time. The second case allows non-vanishing massive and nonlinear terms and depending on the sign of coupling constants gives rise to accelerating mode of expansion or the one that after obtaining some maximum value contracts and ends in big crunch, consequently generating space-time singularity. In case of a Bianchi type-V model there occur two possibilities. In one case we found that the metric functions are similar to each other. In this case the Universe expands with acceleration if the self-coupling constant is taken to be a positive one, whereas a negative coupling constant gives rise to a cyclic or periodic solution. In the second case the spinor mass and the spinor field nonlinearity vanish and the Universe expands linearly in time. In case of a Bianchi type-III model the space-time remains locally rotationally symmetric all the time

The Verriest Lecture: Color lessons from space, time, and motion

Science.gov (United States)

Shevell, Steven K.

2012-01-01

The appearance of a chromatic stimulus depends on more than the wavelengths composing it. The scientific literature has countless examples showing that spatial and temporal features of light influence the colors we see. Studying chromatic stimuli that vary over space, time or direction of motion has a further benefit beyond predicting color appearance: the unveiling of otherwise concealed neural processes of color vision. Spatial or temporal stimulus variation uncovers multiple mechanisms of brightness and color perception at distinct levels of the visual pathway. Spatial variation in chromaticity and luminance can change perceived three-dimensional shape, an example of chromatic signals that affect a percept other than color. Chromatic objects in motion expose the surprisingly weak link between the chromaticity of objects and their physical direction of motion, and the role of color in inducing an illusory motion direction. Space, time and motion – color’s colleagues – reveal the richness of chromatic neural processing. PMID:22330398

Feynman propagator and space-time transformation technique

International Nuclear Information System (INIS)

Nassar, A.B.

1987-01-01

We evaluate the exact propagator for the time-dependent two-dimensional charged harmonic oscillator in a time-varying magnetic field, by taking direct recourse to the corresponding Schroedinger equation. Through the usage of an appropriate space-time transformation, we show that such a propagator can be obtained from the free propagator in the new space-time coordinate system. (orig.)

The Development of Environmental Conservation Youth Camping Using Environmental Education Process

Directory of Open Access Journals (Sweden)

Okrit Tee-ngarm

2016-12-01

Full Text Available The purposes of this research were: to make youths camp activities using environmental education process, to study and to compare the knowledge and attitude before and after the camp activities for conserving environment by using the process of environmental education. The sample were 30 youths in Mueng district, Sisaket province. The tools used in the research including activity manual, knowledge test, attitudes test and participation measurement. The data were analyzed by percentage, mean, standard deviation, and Paired t-test at significant level .05. The result showed that After camp activities for conserving environment by using the process of environmental education, the participats had mean score of knowledge and attitude toward environmental conservation at was higher than before the activities at statistical significantly level .05. And they had participation in youths camp activities for environmental conservation at the most level.

Space and time in ecology: Noise or fundamental driver? [chapter 2

Science.gov (United States)

Samuel A. Cushman

2010-01-01

In this chapter I frame the central issue of the book, namely is spatial and temporal complexity in ecological systems merely noise around the predictions of non-spatial, equilibrium processes? Or, alternatively, do spatial and temporal variability in the environment and autogenic space­time processes in populations fundamentally alter system behavior such that ideal...

Space-Time Disarray and Visual Awareness

Directory of Open Access Journals (Sweden)

Jan Koenderink

2012-04-01

Full Text Available Local space-time scrambling of optical data leads to violent jerks and dislocations. On masking these, visual awareness of the scene becomes cohesive, with dislocations discounted as amodally occluding foreground. Such cohesive space-time of awareness is technically illusory because ground truth is jumbled whereas awareness is coherent. Apparently the visual field is a construction rather than a (veridical perception.

Environmental monitors in the Midcourse Space Experiments (MSX)

Science.gov (United States)

Uy, O. M.

1993-01-01

The Midcourse Space Experiment (MSX) is an SDIO sponsored space based sensor experiment with a full complement of optical sensors. Because of the possible deleterious effect of both molecular and particulate contamination on these sensors, a suite of environmental monitoring instruments are also being flown with the spacecraft. These instruments are the Total Pressure Sensor based on the cold-cathode gauge, a quadrupole mass spectrometer, a Bennett-type ion mass spectrometer, a cryogenic quartz crystal microbalance (QCM), four temperature-controlled QCM's, and a Xenon and Krypton Flash Lamp Experiment. These instruments have been fully space-qualified, are compact and low cost, and are possible candidate sensors for near-term planetary and atmospheric monitoring. The philosophy adopted during design and fabrication, calibration and ground testing, and modeling will be discussed .

About the coordinate time for photons in Lifshitz space-times

Energy Technology Data Exchange (ETDEWEB)

Villanueva, J.R. [Universidad de Valparaiso, Departamento de Fisica y Astronomia, Facultad de Ciencias, Valparaiso (Chile); Centro de Astrofisica de Valparaiso, Valparaiso (Chile); Vasquez, Yerko [Universidad de La Frontera, Departamento de Ciencias Fisicas, Facultad de Ingenieria, Ciencias y Administracion, Temuco (Chile); Universidad de La Serena, Departamento de Fisicas, Facultad de Ciencias, La Serena (Chile)

2013-10-15

In this paper we studied the behavior of radial photons from the point of view of the coordinate time in (asymptotically) Lifshitz space-times, and we found a generalization to the result reported in previous works by Cruz et al. (Eur. Phys. J. C 73:7, 2013), Olivares et al. (Astrophys. Space Sci. 347:83-89, 2013), and Olivares et al. arXiv:1306.5285. We demonstrate that all asymptotically Lifshitz space-times characterized by a lapse function f(r) which tends to one when r{yields}{infinity}, present the same behavior, in the sense that an external observer will see that photons arrive at spatial infinity in a finite coordinate time. Also, we show that radial photons in the proper system cannot determine the presence of the black hole in the region r{sub +}time as a result is independent of the lapse function f(r). (orig.)

Space Station Environmental Health System water quality monitoring

Science.gov (United States)

Vincze, Johanna E.; Sauer, Richard L.

1990-01-01

One of the unique aspects of the Space Station is that it will be a totally encapsulated environment and the air and water supplies will be reclaimed for reuse. The Environmental Health System, a subsystem of CHeCS (Crew Health Care System), must monitor the air and water on board the Space Station Freedom to verify that the quality is adequate for crew safety. Specifically, the Water Quality Subsystem will analyze the potable and hygiene water supplies regularly for organic, inorganic, particulate, and microbial contamination. The equipment selected to perform these analyses will be commercially available instruments which will be converted for use on board the Space Station Freedom. Therefore, the commercial hardware will be analyzed to identify the gravity dependent functions and modified to eliminate them. The selection, analysis, and conversion of the off-the-shelf equipment for monitoring the Space Station reclaimed water creates a challenging project for the Water Quality engineers and scientists.

Quantum space-time and gravitational consequences

International Nuclear Information System (INIS)

Namsrai, K.

1986-01-01

Relativistic particle dynamics and basic physical quantities for the general theory of gravity are reconstructed from a quantum space-time point of view. An additional force caused by quantum space-time appears in the equation of particle motion, giving rise to a reformulation of the equivalence principle up to values of O(L 2 ), where L is the fundamental length. It turns out that quantum space-time leads to quantization of gravity, i.e. the metric tensor g/sub uv/ (/ZETA/) becomes operator-valued and is not commutative at different points x/sup micro/ and y/sup micro/ in usual space-time on a large scale, and its commutator depending on the ''vielbein'' field (gaugelike graviton field) is proportional to L 2 multiplied by a translationinvariant wave function propagated between points x/sup micro/ and y/sup micro/. In the given scheme, there appears to be an antigravitational effect in the motion of a particle in the gravitational force. This effect depends on the value of particle mass; when a particle is heavy its free-fall time is long compared to that for a light-weight particle. The problem of the change of time scale and the anisotropy of inertia are discussed. From experimental data from testing of the latter effect it follows that L ≤ 10 -22 cm

Environmental assessment for the Processing and Environmental Technology Laboratory (PETL)

International Nuclear Information System (INIS)

1995-09-01

The U.S. Department of Energy (DOE) has prepared an environmental assessment (EA) on the proposed Processing and Environmental Technology Laboratory (PETC) at Sandia National Laboratories/New Mexico (SNL/NM). This facility is needed to integrate, consolidate, and enhance the materials science and materials process research and development (R ampersand D) currently in progress at SNL/NM. Based on the analyses in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an environmental impact statement is not required, and DOE is issuing this Finding of No Significant Impact (FONSI)

Environmental assessment for the Processing and Environmental Technology Laboratory (PETL)

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

The U.S. Department of Energy (DOE) has prepared an environmental assessment (EA) on the proposed Processing and Environmental Technology Laboratory (PETC) at Sandia National Laboratories/New Mexico (SNL/NM). This facility is needed to integrate, consolidate, and enhance the materials science and materials process research and development (R&D) currently in progress at SNL/NM. Based on the analyses in the EA, DOE has determined that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an environmental impact statement is not required, and DOE is issuing this Finding of No Significant Impact (FONSI).

A space-time rainfall generator for highly convective Mediterranean rainstorms

Directory of Open Access Journals (Sweden)

S. Salsón

2003-01-01

Full Text Available Distributed hydrological models require fine resolution rainfall inputs, enhancing the practical interest of space-time rainfall models, capable of generating through numerical simulation realistic space-time rainfall intensity fields. Among different mathematical approaches, those based on point processes and built upon a convenient analytical description of the raincell as the fundamental unit, have shown to be particularly suitable and well adapted when extreme rainfall events of convective nature are considered. Starting from previous formulations, some analytical refinements have been considered, allowing practical generation of space-time rainfall intensity fields for that type of rainstorm events. Special attention is placed on the analytical description of the spatial and temporal evolution of the rainfall intensities produced by the raincells. After deriving the necessary analytical results, the seven parameters of the model have been estimated by the method of moments, for each of the 30 selected rainfall events in the Jucar River Basin (ValenciaSpain – period 1991 to 2000, using 5-min aggregated rainfall data series from an automatic raingauge network.

New technology in everyday life - social processes and environmental impact

DEFF Research Database (Denmark)

Røpke, Inge

2001-01-01

In the environmental debate it is increasingly acknowledged that our way of life has profound environmental consequences. Therefore, it becomes ever more important to focus on and to understand how everyday life is formed and how it changes over time. Changing technology constitutes an important...... of several of the dynamic forces behind consumption and thus contribute to the growing quantities of consumption, which counteract the environmental improvements. Secondly, because some of the technological changes are integrated with the processes which change everyday life more profoundly and thus...

Solar Sail Material Performance Property Response to Space Environmental Effects

Science.gov (United States)

Edwards, David L.; Semmel, Charles; Hovater, Mary; Nehls, Mary; Gray, Perry; Hubbs, Whitney; Wertz, George

2004-01-01

The National Aeronautics and Space Administration's (NASA) Marshall Space Flight Center (MSFC) continues research into the utilization of photonic materials for spacecraft propulsion. Spacecraft propulsion, using photonic materials, will be achieved using a solar sail. A solar sail operates on the principle that photons, originating from the sun, impart pressure to the sail and therefore provide a source for spacecraft propulsion. The pressure imparted to a solar sail can be increased, up to a factor of two, if the sun-facing surface is perfectly reflective. Therefore, these solar sails are generally composed of a highly reflective metallic sun-facing layer, a thin polymeric substrate and occasionally a highly emissive back surface. Near term solar sail propelled science missions are targeting the Lagrange point 1 (Ll) as well as locations sunward of L1 as destinations. These near term missions include the Solar Polar Imager and the L1 Diamond. The Environmental Effects Group at NASA s Marshall Space Flight Center (MSFC) continues to actively characterize solar sail material in preparation for these near term solar sail missions. Previous investigations indicated that space environmental effects on sail material thermo-optical properties were minimal and would not significantly affect the propulsion efficiency of the sail. These investigations also indicated that the sail material mechanical stability degrades with increasing radiation exposure. This paper will further quantify the effect of space environmental exposure on the mechanical properties of candidate sail materials. Candidate sail materials for these missions include Aluminum coated Mylar[TM], Teonex[TM], and CPl (Colorless Polyimide). These materials were subjected to uniform radiation doses of electrons and protons in individual exposures sequences. Dose values ranged from 100 Mrads to over 5 Grads. The engineering performance property responses of thermo-optical and mechanical properties were

The space shuttle payload planning working groups: Volume 9: Materials processing and space manufacturing

Science.gov (United States)

1973-01-01

The findings and recommendations of the Materials Processing and Space Manufacturing group of the space shuttle payload planning activity are presented. The effects of weightlessness on the levitation processes, mixture stability, and control over heat and mass transport in fluids are considered for investigation. The research and development projects include: (1) metallurgical processes, (2) electronic materials, (3) biological applications, and (4)nonmetallic materials and processes. Additional recommendations are provided concerning the allocation of payload space, acceptance of experiments for flight, flight qualification, and private use of the space shuttle.

Space time problems and applications

DEFF Research Database (Denmark)

Dethlefsen, Claus

models, cubic spline models and structural time series models. The development of state space theory has interacted with the development of other statistical disciplines.   In the first part of the Thesis, we present the theory of state space models, including Gaussian state space models, approximative...... analysis of non-Gaussian models, simulation based techniques and model diagnostics.   The second part of the Thesis considers Markov random field models. These are spatial models applicable in e.g. disease mapping and in agricultural experiments. Recently, the Gaussian Markov random field models were...... techniques with importance sampling.   The third part of the Thesis contains applications of the theory. First, a univariate time series of count data is analysed. Then, a spatial model is used to compare wheat yields. Weed count data in connection with a project in precision farming is analysed using...

Space-time structure

CERN Document Server

Schrödinger, Erwin

1985-01-01

In response to repeated requests this classic book on space-time structure by Professor Erwin Schrödinger is now available in the Cambridge Science Classics series. First published in 1950, and reprinted in 1954 and 1960, this lucid and profound exposition of Einstein's 1915 theory of gravitation still provides valuable reading for students and research workers in the field.

Collision-free gases in spatially homogeneous space-times

International Nuclear Information System (INIS)

Maartens, R.; Maharaj, S.D.

1985-01-01

The kinematical and dynamical properties of one-component collision-free gases in spatially homogeneous, locally rotationally symmetric (LRS) space-times are analyzed. Following Ray and Zimmerman [Nuovo Cimento B 42, 183 (1977)], it is assumed that the distribution function f of the gas inherits the symmetry of space-time, in order to construct solutions of Liouville's equation. The redundancy of their further assumption that f be based on Killing vector constants of the motion is shown. The Ray and Zimmerman results for Kantowski--Sachs space-time are extended to all spatially homogeneous LRS space-times. It is shown that in all these space-times the kinematic average four-velocity u/sup i/ can be tilted relative to the homogeneous hypersurfaces. This differs from the perfect fluid case, in which only one space-time admits tilted u/sup i/, as shown by King and Ellis [Commun. Math. Phys. 31, 209 (1973)]. As a consequence, it is shown that all space-times admit nonzero acceleration and heat flow, while a subclass admits nonzero vorticity. The stress π/sub i/j is proportional to the shear sigma/sub i/j by virtue of the invariance of the distribution function. The evolution of tilt and the existence of perfect fluid solutions is also discussed

NPOESS Interface Data Processing Segment Product Generation

Science.gov (United States)

Grant, K. D.

2009-12-01

The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The NPOESS design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. The IDPS processes NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government. The IDPS will process environmental data products beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. Within the overall NPOESS processing environment, the IDPS must process a data volume nearly 1000 times the size of current systems -- in one-quarter of the time. Further, it must support the calibration, validation, and data quality improvement initiatives of the NPOESS program to ensure the production of atmospheric and environmental products that meet strict requirements for accuracy and precision. This paper will describe the architecture approach that is necessary to meet these challenging, and seemingly exclusive, NPOESS IDPS design requirements, with a focus on the processing relationships required to generate the NPP products.

Space-time description of particle creation in gravitational and electromagnetic fields

International Nuclear Information System (INIS)

Mamaev, S.G.; Trunov, N.N.

1983-01-01

The dynamics of the creation of pairs of particles from the vacuum in strong time-dependent external fields is studied. The space-time correlation function of the pair is determined. An analysis of the behavior of this function allows one, in particular, to study the pair-creation process, to distinguish between real and virtual particles, etc

Application of Kalman Filter for Estimating a Process Disturbance in a Building Space

Directory of Open Access Journals (Sweden)

Deuk-Woo Kim

2017-10-01

Full Text Available This paper addresses an application of the Kalman filter for estimating a time-varying process disturbance in a building space. The process disturbance means a synthetic composite of heat gains and losses caused by internal heat sources e.g., people, lights, equipment, and airflows. It is difficult to measure and quantify the internal heat sources and airflows due to their dynamic nature and time-lag impact on indoor environment. To address this issue, a Kalman filter estimation method was used in this study. The Kalman filtering is well suited for situations when state variables of interest cannot be measured. Based on virtual and real experiments conducted in this study, it was found that the Kalman filter can be used to estimate the time-varying process disturbance in a building space.

Students' Imaginings of Spaces of Learning in Outdoor and Environmental Education

Science.gov (United States)

Preston, Lou

2014-01-01

In this article, I interrogate students' stories about the spaces and places in a tertiary Outdoor and Environmental Education course that support and shape their environmental ethics. Drawing on a longitudinal qualitative study, I explore the ways in which particular sites of learning (outdoor, practical learning) are privileged and how…

Minkowski space-time is locally extendible

International Nuclear Information System (INIS)

Beem, J.K.

1980-01-01

An example of a real analytic local extension of Minkowski space-time is given in this note. This local extension is not across points of the b-boundary since Minkowski space-time has an empty b-boundary. Furthermore, this local extension is not across points of the causal boundary. The example indicates that the concept of local inextendibility may be less useful than originally envisioned. (orig.)

Coupling gravity, electromagnetism and space-time for space propulsion breakthroughs

Science.gov (United States)

Millis, Marc G.

1994-01-01

spaceflight would be revolutionized if it were possible to propel a spacecraft without rockets using the coupling between gravity, electromagnetism, and space-time (hence called 'space coupling propulsion'). New theories and observations about the properties of space are emerging which offer new approaches to consider this breakthrough possibility. To guide the search, evaluation, and application of these emerging possibilities, a variety of hypothetical space coupling propulsion mechanisms are presented to highlight the issues that would have to be satisfied to enable such breakthroughs. A brief introduction of the emerging opportunities is also presented.

Space-Time Discrete KPZ Equation

Science.gov (United States)

Cannizzaro, G.; Matetski, K.

2018-03-01

We study a general family of space-time discretizations of the KPZ equation and show that they converge to its solution. The approach we follow makes use of basic elements of the theory of regularity structures (Hairer in Invent Math 198(2):269-504, 2014) as well as its discrete counterpart (Hairer and Matetski in Discretizations of rough stochastic PDEs, 2015. arXiv:1511.06937). Since the discretization is in both space and time and we allow non-standard discretization for the product, the methods mentioned above have to be suitably modified in order to accommodate the structure of the models under study.

Pre-Big Bang, space-time structure, asymptotic Universe. Spinorial space-time and a new approach to Friedmann-like equations

Science.gov (United States)

Gonzalez-Mestres, Luis

2014-04-01

Planck and other recent data in Cosmology and Particle Physics can open the way to controversial analyses concerning the early Universe and its possible ultimate origin. Alternatives to standard cosmology include pre-Big Bang approaches, new space-time geometries and new ultimate constituents of matter. Basic issues related to a possible new cosmology along these lines clearly deserve further exploration. The Planck collaboration reports an age of the Universe t close to 13.8 Gyr and a present ratio H between relative speeds and distances at cosmic scale around 67.3 km/s/Mpc. The product of these two measured quantities is then slightly below 1 (about 0.95), while it can be exactly 1 in the absence of matter and cosmological constant in patterns based on the spinorial space-time we have considered in previous papers. In this description of space-time we first suggested in 1996-97, the cosmic time t is given by the modulus of a SU(2) spinor and the Lundmark-Lemaître-Hubble (LLH) expansion law turns out to be of purely geometric origin previous to any introduction of standard matter and relativity. Such a fundamental geometry, inspired by the role of half-integer spin in Particle Physics, may reflect an equilibrium between the dynamics of the ultimate constituents of matter and the deep structure of space and time. Taking into account the observed cosmic acceleration, the present situation suggests that the value of 1 can be a natural asymptotic limit for the product H t in the long-term evolution of our Universe up to possible small corrections. In the presence of a spinorial space-time geometry, no ad hoc combination of dark matter and dark energy would in any case be needed to get an acceptable value of H and an evolution of the Universe compatible with observation. The use of a spinorial space-time naturally leads to unconventional properties for the space curvature term in Friedmann-like equations. It therefore suggests a major modification of the standard

Environmental effects and large space systems

Science.gov (United States)

Garrett, H. B.

1981-01-01

When planning large scale operations in space, environmental impact must be considered in addition to radiation, spacecraft charging, contamination, high power and size. Pollution of the atmosphere and space is caused by rocket effluents and by photoelectrons generated by sunlight falling on satellite surfaces even light pollution may result (the SPS may reflect so much light as to be a nuisance to astronomers). Large (100 Km 2) structures also will absorb the high energy particles that impinge on them. Altogether, these effects may drastically alter the Earth's magnetosphere. It is not clear if these alterations will in any way affect the Earth's surface climate. Large structures will also generate large plasma wakes and waves which may cause interference with communications to the vehicle. A high energy, microwave beam from the SPS will cause ionospheric turbulence, affecting UHF and VHF communications. Although none of these effects may ultimately prove critical, they must be considered in the design of large structures.

A higher order space-time Galerkin scheme for time domain integral equations

KAUST Repository

Pray, Andrew J.

2014-12-01

Stability of time domain integral equation (TDIE) solvers has remained an elusive goal formany years. Advancement of this research has largely progressed on four fronts: 1) Exact integration, 2) Lubich quadrature, 3) smooth temporal basis functions, and 4) space-time separation of convolutions with the retarded potential. The latter method\\'s efficacy in stabilizing solutions to the time domain electric field integral equation (TD-EFIE) was previously reported for first-order surface descriptions (flat elements) and zeroth-order functions as the temporal basis. In this work, we develop the methodology necessary to extend the scheme to higher order surface descriptions as well as to enable its use with higher order basis functions in both space and time. These basis functions are then used in a space-time Galerkin framework. A number of results are presented that demonstrate convergence in time. The viability of the space-time separation method in producing stable results is demonstrated experimentally for these examples.

A higher order space-time Galerkin scheme for time domain integral equations

KAUST Repository

Pray, Andrew J.; Beghein, Yves; Nair, Naveen V.; Cools, Kristof; Bagci, Hakan; Shanker, Balasubramaniam

2014-01-01

Stability of time domain integral equation (TDIE) solvers has remained an elusive goal formany years. Advancement of this research has largely progressed on four fronts: 1) Exact integration, 2) Lubich quadrature, 3) smooth temporal basis functions, and 4) space-time separation of convolutions with the retarded potential. The latter method's efficacy in stabilizing solutions to the time domain electric field integral equation (TD-EFIE) was previously reported for first-order surface descriptions (flat elements) and zeroth-order functions as the temporal basis. In this work, we develop the methodology necessary to extend the scheme to higher order surface descriptions as well as to enable its use with higher order basis functions in both space and time. These basis functions are then used in a space-time Galerkin framework. A number of results are presented that demonstrate convergence in time. The viability of the space-time separation method in producing stable results is demonstrated experimentally for these examples.

Simulated Space Environmental Effects on Thin Film Solar Array Components

Science.gov (United States)

Finckenor, Miria; Carr, John; SanSoucie, Michael; Boyd, Darren; Phillips, Brandon

2017-01-01

The Lightweight Integrated Solar Array and Transceiver (LISA-T) experiment consists of thin-film, low mass, low volume solar panels. Given the variety of thin solar cells and cover materials and the lack of environmental protection typically afforded by thick coverglasses, a series of tests were conducted in Marshall Space Flight Center's Space Environmental Effects Facility to evaluate the performance of these materials. Candidate thin polymeric films and nitinol wires used for deployment were also exposed. Simulated space environment exposures were selected based on SSP 30425 rev. B, "Space Station Program Natural Environment Definition for Design" or AIAA Standard S-111A-2014, "Qualification and Quality Requirements for Space Solar Cells." One set of candidate materials were exposed to 5 eV atomic oxygen and concurrent vacuum ultraviolet (VUV) radiation for low Earth orbit simulation. A second set of materials were exposed to 1 MeV electrons. A third set of samples were exposed to 50, 100, 500, and 700 keV energy protons, and a fourth set were exposed to >2,000 hours of near ultraviolet (NUV) radiation. A final set was rapidly thermal cycled between -55 and +125degC. This test series provides data on enhanced power generation, particularly for small satellites with reduced mass and volume resources. Performance versus mass and cost per Watt is discussed.

Environmental Physiology at the Johnson Space Center: Past, Present, and Future

Science.gov (United States)

Conkin, Johnny

2007-01-01

This viewgraph presentation reviews the work in environmental physiology done at Johnson Space Center (JSC). The work is aimed at keeping astronauts healthy. This is a different approach than treating the sick, and is more of an occupational health model. The reduction of risks is the main emphasis for this work. They emphasis is to reduce the risk of decompression sickness (DCS) and acute mountain sickness (AMS). The work in environmental physiology encompasses the following areas: (1) Pressure: hypobaric and hyperbaric (2) Gases: hypoxia and hyperoxia, hypercapnia--closed space issues, inert gas physiology / respiration (3) Temperature: hypothermia and hyperthermia, thermal comfort, Protective clothing diving, aviation, mountaineering, and space (4) Acceleration (5) Noise and Vibration (6) Exercise / Performance (6) Acclimatization / Adaptation: engineering solutions when necessary. This presentation reviews the work done at JSC in the areas of DCS and AMS.

A framework for techno-economic & environmental sustainability analysis by risk assessment for conceptual process evaluation

DEFF Research Database (Denmark)

Loureiro da Costa Lira Gargalo, Carina; Sin, Gürkan; Carvalho, Ana

2016-01-01

for techno-economic and environmental sustainability analysis through risk assessment is proposed for the early-stage design and screening of conceptual process alternatives. The alternatives within the design space are analyzed following the framework’s work-flow, which targets the following: (i) quantify...... the economic risk; (ii) perform the monetary valuation of environmental impact categories under uncertainty; (iii) quantify the potential environmental risk; (iv) measure the alternatives’ eco-efficiency identifying possible trade-offs; and, lastly (v) propose a joint risk assessment matrix......The need to achieve a sustainable process performance has become increasingly important in order to keep a competitive advantage in the global markets. Development of comprehensive and systematic methods to accomplish this goal is the subject of this work. To this end, a multi-level framework...

A framework for techno-economic & environmental sustainability analysis by risk assessment for conceptual process evaluation

DEFF Research Database (Denmark)

Loureiro da Costa Lira Gargalo, Carina; Sin, Gürkan; Carvalho, Ana

2016-01-01

the economic risk; (ii) perform the monetary valuation of environmental impact categories under uncertainty; (iii) quantify the potential environmental risk; (iv) measure the alternatives’ eco-efficiency identifying possible trade-offs; and, lastly (v) propose a joint risk assessment matrix......The need to achieve a sustainable process performance has become increasingly important in order to keep a competitive advantage in the global markets. Development of comprehensive and systematic methods to accomplish this goal is the subject of this work. To this end, a multi-level framework...... for techno-economic and environmental sustainability analysis through risk assessment is proposed for the early-stage design and screening of conceptual process alternatives. The alternatives within the design space are analyzed following the framework’s work-flow, which targets the following: (i) quantify...

Monitoring Space Radiation Hazards with the Responsive Environmental Assessment Commercially Hosted (REACH) Project

Science.gov (United States)

Mazur, J. E.; Guild, T. B.; Crain, W.; Crain, S.; Holker, D.; Quintana, S.; O'Brien, T. P., III; Kelly, M. A.; Barnes, R. J.; Sotirelis, T.

2017-12-01

The Responsive Environmental Assessment Commercial Hosting (REACH) project uses radiation dosimeters on a commercial satellite constellation in low Earth orbit to provide unprecedented spatial and time sampling of space weather radiation hazards. The spatial and time scales of natural space radiation environments coupled with constraints for the hosting accommodation drove the instrumentation requirements and the plan for the final orbital constellation. The project has delivered a total of thirty two radiation dosimeter instruments for launch with each instrument containing two dosimeters with different passive shielding and electronic thresholds to address proton-induced single-event effects, vehicle charging, and total ionizing dose. There are two REACH instruments currently operating with four more planned for launch by the time of the 2017 meeting. Our aim is to field a long-lived system of highly-capable radiation detectors to monitor the hazards of single-event effects, total ionizing dose, and spacecraft charging with maximized spatial coverage and with minimal time latency. We combined a robust detection technology with a commercial satellite hosting to produce a new demonstration for satellite situational awareness and for other engineering and science applications.

Governing Global Environmental Flows: Ecological Modernization in Technonatural Time/Spaces

NARCIS (Netherlands)

Oosterveer, P.J.M.

2009-01-01

Environmentalism and social sciences appear to be in a period of disorientation and perhaps transition. In this innovative collection, leading international thinkers explore the notion that one explanation for the current malaise of the ¿politics of ecology¿ is that we increasingly find ourselves

Labeling RDF Graphs for Linear Time and Space Querying

Science.gov (United States)

Furche, Tim; Weinzierl, Antonius; Bry, François

Indices and data structures for web querying have mostly considered tree shaped data, reflecting the view of XML documents as tree-shaped. However, for RDF (and when querying ID/IDREF constraints in XML) data is indisputably graph-shaped. In this chapter, we first study existing indexing and labeling schemes for RDF and other graph datawith focus on support for efficient adjacency and reachability queries. For XML, labeling schemes are an important part of the widespread adoption of XML, in particular for mapping XML to existing (relational) database technology. However, the existing indexing and labeling schemes for RDF (and graph data in general) sacrifice one of the most attractive properties of XML labeling schemes, the constant time (and per-node space) test for adjacency (child) and reachability (descendant). In the second part, we introduce the first labeling scheme for RDF data that retains this property and thus achieves linear time and space processing of acyclic RDF queries on a significantly larger class of graphs than previous approaches (which are mostly limited to tree-shaped data). Finally, we show how this labeling scheme can be applied to (acyclic) SPARQL queries to obtain an evaluation algorithm with time and space complexity linear in the number of resources in the queried RDF graph.

The Cauchy problem for space-time monopole equations in Sobolev spaces

Science.gov (United States)

Huh, Hyungjin; Yim, Jihyun

2018-04-01

We consider the initial value problem of space-time monopole equations in one space dimension with initial data in Sobolev space Hs. Observing null structures of the system, we prove local well-posedness in almost critical space. Unconditional uniqueness and global existence are proved for s ≥ 0. Moreover, we show that the H1 Sobolev norm grows at a rate of at most c exp(ct2).

Low Cost Environmental Sensors for Spaceflight: NMP Space Environmental Monitor (SEM) Requirements

Science.gov (United States)

Garrett, Henry B.; Buehler, Martin G.; Brinza, D.; Patel, J. U.

2005-01-01

An outstanding problem in spaceflight is the lack of adequate sensors for monitoring the space environment and its effects on engineering systems. By adequate, we mean low cost in terms of mission impact (e.g., low price, low mass/size, low power, low data rate, and low design impact). The New Millennium Program (NMP) is investigating the development of such a low-cost Space Environmental Monitor (SEM) package for inclusion on its technology validation flights. This effort follows from the need by NMP to characterize the space environment during testing so that potential users can extrapolate the test results to end-use conditions. The immediate objective of this effort is to develop a small diagnostic sensor package that could be obtained from commercial sources. Environments being considered are: contamination, atomic oxygen, ionizing radiation, cosmic radiation, EMI, and temperature. This talk describes the requirements and rational for selecting these environments and reviews a preliminary design that includes a micro-controller data logger with data storage and interfaces to the sensors and spacecraft. If successful, such a sensor package could be the basis of a unique, long term program for monitoring the effects of the space environment on spacecraft systems.

Optimizing the space-time-yield and the specific energy consumption of molten salt electrolysis processes for the electrowinning of metals in subgroups 4 and 5 of the periodic table of elements

International Nuclear Information System (INIS)

Koeck, W.

1988-04-01

Disadvantages of molten salt electrolysis are its low space-time-yield (kg/m 3 h) combined with its high specific energy consumption (kWh/kg). These factors essentially determine how electrolysis is applied on an industrial scale. The electrolysis of tantalum was selected as an example representative for other electrolytic processes; this series of tests allow statements also on the winning of the other elements from subgroups 4 and 5 of the periodic table, and on electrolytic aluminium extraction. Optimal operating conditions for direct current electrolysis were determined in the laboratory by varying the current density and the electrolysis temperature. In order to improve the space-time-yield from an existing electrolytic cell with a given electrolyte composition beyond the optimal range of direct current electrolysis, the process of periodic current reversal is applied. In this process, the polarity is reversed for a short time at constant periodic intervals. If the forward time period and the backward time period are chosen in a suitable way, both the current efficiency and the space-time-yield can be improved without increasing the energy consumption. 59 refs., 48 figs., 8 tabs. (Author)

The Study of Environmental Crisis and Local Distribution of Green Space in Tehran City

OpenAIRE

K. zayyari; L. Vahedian Beiky; Z. Parnoon

2012-01-01

Extended abstract1-IntroductionUncontrolled development of large cities due to the increase in population and migration has led to a massive environmental destruction and pollution, and the latter has destroyed green spaces within the city and changed the land use. Therefore, the need for green space and connection with nature has an important role in human life. The best way to reduce the destructive effects of environmental hazards is the development of green space. Due to its wide range of...

On Yang's Noncommutative Space Time Algebra, Holography, Area Quantization and C-space Relativity

CERN Document Server

Castro, C

2004-01-01

An isomorphism between Yang's Noncommutative space-time algebra (involving two length scales) and the holographic-area-coordinates algebra of C-spaces (Clifford spaces) is constructed via an AdS_5 space-time which is instrumental in explaining the origins of an extra (infrared) scale R in conjunction to the (ultraviolet) Planck scale lambda characteristic of C-spaces. Yang's space-time algebra allowed Tanaka to explain the origins behind the discrete nature of the spectrum for the spatial coordinates and spatial momenta which yields a minimum length-scale lambda (ultraviolet cutoff) and a minimum momentum p = (\\hbar / R) (maximal length R, infrared cutoff). The double-scaling limit of Yang's algebra : lambda goes to 0, and R goes to infinity, in conjunction with the large n infinity limit, leads naturally to the area quantization condition : lambda R = L^2 = n lambda^2 (in Planck area units) given in terms of the discrete angular-momentum eigenvalues n . The generalized Weyl-Heisenberg algebra in C-spaces is ...

Space, Time, and Spacetime Physical and Philosophical Implications of Minkowski's Unification of Space and Time

CERN Document Server

Petkov, Vesselin

2010-01-01

This volume is dedicated to the centennial anniversary of Minkowski's discovery of spacetime. It contains selected papers by physicists and philosophers on the Nature and Ontology of Spacetime. The first six papers, comprising Part I of the book, provide examples of the impact of Minkowski's spacetime representation of special relativity on the twentieth century physics. Part II also contains six papers which deal with implications of Minkowski's ideas for the philosophy of space and time. The last part is represented by two papers which explore the influence of Minkowski's ideas beyond the philosophy of space and time.

Empty space-times with separable Hamilton-Jacobi equation

International Nuclear Information System (INIS)

Collinson, C.D.; Fugere, J.

1977-01-01

All empty space-times admitting a one-parameter group of motions and in which the Hamilton-Jacobi equation is (partially) separable are obtained. Several different cases of such empty space-times exist and the Riemann tensor is found to be either type D or N. The results presented here complete the search for empty space-times with separable Hamilton-Jacobi equation. (author)

Is space-time symmetry a suitable generalization of parity-time symmetry?

International Nuclear Information System (INIS)

Amore, Paolo; Fernández, Francisco M.; Garcia, Javier

2014-01-01

We discuss space-time symmetric Hamiltonian operators of the form H=H 0 +igH ′ , where H 0 is Hermitian and g real. H 0 is invariant under the unitary operations of a point group G while H ′ is invariant under transformation by elements of a subgroup G ′ of G. If G exhibits irreducible representations of dimension greater than unity, then it is possible that H has complex eigenvalues for sufficiently small nonzero values of g. In the particular case that H is parity-time symmetric then it appears to exhibit real eigenvalues for all 00. We illustrate the main theoretical results and conclusions of this paper by means of two- and three-dimensional Hamiltonians exhibiting a variety of different point-group symmetries. - Highlights: • Space-time symmetry is a generalization of PT symmetry. • The eigenvalues of a space-time Hamiltonian are either real or appear as pairs of complex conjugate numbers. • In some cases all the eigenvalues are real for some values of a potential-strength parameter g. • At some value of g space-time symmetry is broken and complex eigenvalues appear. • Some multidimensional oscillators exhibit broken space-time symmetry for all values of g

Quaternion wave equations in curved space-time

Science.gov (United States)

Edmonds, J. D., Jr.

1974-01-01

The quaternion formulation of relativistic quantum theory is extended to include curvilinear coordinates and curved space-time in order to provide a framework for a unified quantum/gravity theory. Six basic quaternion fields are identified in curved space-time, the four-vector basis quaternions are identified, and the necessary covariant derivatives are obtained. Invariant field equations are derived, and a general invertable coordinate transformation is developed. The results yield a way of writing quaternion wave equations in curvilinear coordinates and curved space-time as well as a natural framework for solving the problem of second quantization for gravity.

Environmental and process monitoring technologies

International Nuclear Information System (INIS)

Vo-Dinh, Tuan

1993-01-01

The objective of this conference was to provide a multidisciplinary forum dealing with state-of-the-art methods and instrumentation for environmental and process monitoring. In the last few years, important advances have been made in improving existing analytical methods and developing new techniques for trace detection of chemicals. These monitoring technologies are a topic of great interest for environmental and industrial control in a wide spectrum of areas. Sensitive detection, selective characterization, and cost-effective analysis are among the most important challenges facing monitoring technologies. This conference integrating interdisciplinary research and development was aimed to present the most recent advances and applications in the important areas of environmental and process monitoring. Separate abstracts have been prepared for 34 papers for inclusion in the appropriate data bases

Time as a geometric property of space

Directory of Open Access Journals (Sweden)

James Michael Chappell

2016-11-01

Full Text Available The proper description of time remains a key unsolved problem in science. Newton conceived of time as absolute and universal which it `flows equably without relation to anything external'}. In the nineteenth century, the four-dimensional algebraic structure of the quaternions developed by Hamilton, inspired him to suggest that they could provide a unified representation of space and time. With the publishing of Einstein's theory of special relativity these ideas then lead to the generally accepted Minkowski spacetime formulation in 1908. Minkowski, though, rejected the formalism of quaternions suggested by Hamilton and adopted rather an approach using four-vectors. The Minkowski framework is indeed found to provide a versatile formalism for describing the relationship between space and time in accordance with Einstein's relativistic principles, but nevertheless fails to provide more fundamental insights into the nature of time itself. In order to answer this question we begin by exploring the geometric properties of three-dimensional space that we model using Clifford geometric algebra, which is found to contain sufficient complexity to provide a natural description of spacetime. This description using Clifford algebra is found to provide a natural alternative to the Minkowski formulation as well as providing new insights into the nature of time. Our main result is that time is the scalar component of a Clifford space and can be viewed as an intrinsic geometric property of three-dimensional space without the need for the specific addition of a fourth dimension.

Space-time of class one

International Nuclear Information System (INIS)

Villasenor, R.F.; Bonilla, J.L.L.; Zuniga, G.O.; Matos, T.

1989-01-01

The authors study space-times embedded in E 5 (that means, pseudo-euclidean five-dimensional spaces) in the intrinsic rigidity case, i.e., when the second fundamental form b if can be determined by the internal geometry of the four-dimensional Riemannian space R 4 . They write down the Gauss and Codazzi equations determining the local isometric embedding of R 4 in E 5 and give some consequences of it. They prove that when there exists intrinsic rigidity, then b if is a linear combination of the metric and Ricci tensor; it is given some applications for the de Sitter and Einstein models

Process mining techniques: an application to time management

Science.gov (United States)

Khowaja, Ali Raza

2018-04-01

In an environment people have to make sure that all of their work are completed within a given time in accordance with its quality. In order to achieve the real phenomenon of process mining one needs to understand all of these processes in a detailed manner. Personal Information and communication has always been a highlighting issue on internet but for now information and communication tools within factual life refers to their daily schedule, location analysis, environmental analysis and, more generally, social media applications support these systems which makes data available for data analysis generated through event logs, but also for process analysis which combines environmental and location analysis. Process mining can be used to exploit all these real live processes with the help of the event logs which are already available in those datasets through user censored data or may be user labeled data. These processes could be used to redesign a user's flow and understand all these processes in a bit more detailed manner. In order to increase the quality of each of the processes that we go through our daily lives is to give a closer look to each of the processes and after analyzing them, one should make changes to get better results. On the contrarily, we applied process mining techniques on seven different subjects combined in a single dataset collected from Korea. Above all, the following paper comments on the efficiency of processes in the event logs referring to time management's sphere of influence.

SpaceCube v2.0 Space Flight Hybrid Reconfigurable Data Processing System

Science.gov (United States)

Petrick, Dave

2014-01-01

This paper details the design architecture, design methodology, and the advantages of the SpaceCube v2.0 high performance data processing system for space applications. The purpose in building the SpaceCube v2.0 system is to create a superior high performance, reconfigurable, hybrid data processing system that can be used in a multitude of applications including those that require a radiation hardened and reliable solution. The SpaceCube v2.0 system leverages seven years of board design, avionics systems design, and space flight application experiences. This paper shows how SpaceCube v2.0 solves the increasing computing demands of space data processing applications that cannot be attained with a standalone processor approach.The main objective during the design stage is to find a good system balance between power, size, reliability, cost, and data processing capability. These design variables directly impact each other, and it is important to understand how to achieve a suitable balance. This paper will detail how these critical design factors were managed including the construction of an Engineering Model for an experiment on the International Space Station to test out design concepts. We will describe the designs for the processor card, power card, backplane, and a mission unique interface card. The mechanical design for the box will also be detailed since it is critical in meeting the stringent thermal and structural requirements imposed by the processing system. In addition, the mechanical design uses advanced thermal conduction techniques to solve the internal thermal challenges.The SpaceCube v2.0 processing system is based on an extended version of the 3U cPCI standard form factor where each card is 190mm x 100mm in size The typical power draw of the processor card is 8 to 10W and scales with application complexity. The SpaceCube v2.0 data processing card features two Xilinx Virtex-5 QV Field Programmable Gate Arrays (FPGA), eight memory modules, a monitor

Natural world physical, brain operational, and mind phenomenal space-time

Science.gov (United States)

Fingelkurts, Andrew A.; Fingelkurts, Alexander A.; Neves, Carlos F. H.

2010-06-01

Concepts of space and time are widely developed in physics. However, there is a considerable lack of biologically plausible theoretical frameworks that can demonstrate how space and time dimensions are implemented in the activity of the most complex life-system - the brain with a mind. Brain activity is organized both temporally and spatially, thus representing space-time in the brain. Critical analysis of recent research on the space-time organization of the brain's activity pointed to the existence of so-called operational space-time in the brain. This space-time is limited to the execution of brain operations of differing complexity. During each such brain operation a particular short-term spatio-temporal pattern of integrated activity of different brain areas emerges within related operational space-time. At the same time, to have a fully functional human brain one needs to have a subjective mental experience. Current research on the subjective mental experience offers detailed analysis of space-time organization of the mind. According to this research, subjective mental experience (subjective virtual world) has definitive spatial and temporal properties similar to many physical phenomena. Based on systematic review of the propositions and tenets of brain and mind space-time descriptions, our aim in this review essay is to explore the relations between the two. To be precise, we would like to discuss the hypothesis that via the brain operational space-time the mind subjective space-time is connected to otherwise distant physical space-time reality.

Recursive evaluation of space-time lattice Green's functions

International Nuclear Information System (INIS)

De Hon, Bastiaan P; Arnold, John M

2012-01-01

double the pulse width of the source signature to keep pulse distortion at bay. The GF time sequences can also be used for an efficient computation of discrete space-frequency LGFs, especially if one employs Aitken's δ 2 process for the acceleration of the convergence of the consecutive partial sums. (paper)

Final Environmental Assessment for the California Space Center at Vandenberg Air Force Base, California

Science.gov (United States)

2010-06-02

rooted , mesophylic plant species that Chapter 3. Affected Environment Final Environmental Assessment - California Space Center, Vandenberg Air...Chapter 3. Affected Environment 3-12 Final Environmental Assessment - California Space Center, Vandenberg Air Force Base the root and debris zone of the...protruding objects, slippery soils or mud, and biological hazards including vegetation (i.e. poison oak and stinging nettle ), animals (i.e. insects

Topology of classical vacuum space-time

International Nuclear Information System (INIS)

Cho, Y.M.

2007-04-01

We present a topological classification of classical vacuum space-time. Assuming the 3-dimensional space allows a global chart, we show that the static vacuum space-time of Einstein's theory can be classified by the knot topology π 3 (S 3 ) = π 3 (S 2 ). Viewing Einstein's theory as a gauge theory of Lorentz group and identifying the gravitational connection as the gauge potential of Lorentz group, we construct all possible vacuum gravitational connections which give a vanishing curvature tensor. With this we show that the vacuum connection has the knot topology, the same topology which describes the multiple vacua of SU(2) gauge theory. We discuss the physical implications of our result in quantum gravity. (author)

The Sustainable Development of Space: Astro-environmental and dynamical considerations

Science.gov (United States)

Boley, Aaron; Byers, Michael; Russell, Sara

2018-04-01

The sustainable development of space is a global (and exo-global) challenge that is not limited by borders or research disciplines. Sustainable development is "development that meets the needs of the present without compromising the ability of future generations to meet their own needs". While the development of space brings new economic and scientific possibilities, it also carries significant political, legal, and technical uncertainties. For example, the rapidly increasing accessibility of space is motivating states to unilaterally adopt legislation for the new era of space use, which may have significant unintended consequences, such as increased risks to space assets, disputes among state as well as non-state actors, and changes to unique astro-environments. Any policy or legal position must be informed by the dynamical and astrophysical realities of space use, creating complex and interwoven challenges. Here, we explore several of these potential challenges related to astro-environmentalism, space minining operations, and the associated dynamics.

Quantum Space-Time Deformed Symmetries Versus Broken Symmetries

CERN Document Server

Amelino-Camelia, G

2002-01-01

Several recent studies have concerned the faith of classical symmetries in quantum space-time. In particular, it appears likely that quantum (discretized, noncommutative,...) versions of Minkowski space-time would not enjoy the classical Lorentz symmetries. I compare two interesting cases: the case in which the classical symmetries are "broken", i.e. at the quantum level some classical symmetries are lost, and the case in which the classical symmetries are "deformed", i.e. the quantum space-time has as many symmetries as its classical counterpart but the nature of these symmetries is affected by the space-time quantization procedure. While some general features, such as the emergence of deformed dispersion relations, characterize both the symmetry-breaking case and the symmetry-deformation case, the two scenarios are also characterized by sharp differences, even concerning the nature of the new effects predicted. I illustrate this point within an illustrative calculation concerning the role of space-time symm...

Space-Time Diffeomorphisms in Noncommutative Gauge Theories

Directory of Open Access Journals (Sweden)

L. Román Juarez

2008-07-01

Full Text Available In previous work [Rosenbaum M. et al., J. Phys. A: Math. Theor. 40 (2007, 10367–10382] we have shown how for canonical parametrized field theories, where space-time is placed on the same footing as the other fields in the theory, the representation of space-time diffeomorphisms provides a very convenient scheme for analyzing the induced twisted deformation of these diffeomorphisms, as a result of the space-time noncommutativity. However, for gauge field theories (and of course also for canonical geometrodynamics where the Poisson brackets of the constraints explicitely depend on the embedding variables, this Poisson algebra cannot be connected directly with a representation of the complete Lie algebra of space-time diffeomorphisms, because not all the field variables turn out to have a dynamical character [Isham C.J., Kuchar K.V., Ann. Physics 164 (1985, 288–315, 316–333]. Nonetheless, such an homomorphic mapping can be recuperated by first modifying the original action and then adding additional constraints in the formalism in order to retrieve the original theory, as shown by Kuchar and Stone for the case of the parametrized Maxwell field in [Kuchar K.V., Stone S.L., Classical Quantum Gravity 4 (1987, 319–328]. Making use of a combination of all of these ideas, we are therefore able to apply our canonical reparametrization approach in order to derive the deformed Lie algebra of the noncommutative space-time diffeomorphisms as well as to consider how gauge transformations act on the twisted algebras of gauge and particle fields. Thus, hopefully, adding clarification on some outstanding issues in the literature concerning the symmetries for gauge theories in noncommutative space-times.

International Space Station Environmental Control and Life Support System Status: 2008 - 2009

Science.gov (United States)

Williams, David E.; Gentry, Gregory J.; Gentry, Gregory J.

2009-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between March 2008 and February 2009. The ISS continued permanent crew operations, with the continuation of Phase 3 of the ISS Assembly Sequence. Work continues on the last of the Phase 3 pressurized elements and the continued manufacturing and testing of the regenerative ECLS equipment.

International Space Station Environmental Control and Life Support System Status: 2010 - 2011

Science.gov (United States)

Williams, David E.; Gentry, Gregory J.

2010-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between March 2010 and February 2011 and the continued permanent presence of six crew members on ISS. Work continues on the last of the Phase 3 pressurized elements, commercial cargo resupply vehicles, and extension of the ISS service life from 2015 to 2020 or beyond.

Search route decision of environmental monitoring at emergency time

International Nuclear Information System (INIS)

Aoyama, Isao

1979-01-01

The search route decision method is reviewed, especially the adequate arrangement of monitors in view of time in the information-gathering activity by transferring the monitors on the horizontal space after the confirmation of the abnormal release of radioactive material. As for the field of the theory of search, the developmental history is explained, namely the experiences of the naval anti submarine operation in WW-2, the salvage activities and the search problem on the sea. The kinematics for search, the probability theory for detection and the optimum distribution for search are the most important contents of the application of theory of search relating to the environmental monitoring at emergency condition. The combination of a search model consists of the peculiarity of targets, the peculiarity of observers and the standard of optimality. The peculiarity of targets is divided into the space of search, the number of targets, the way of appearance of targets and the motion of targets. The peculiarity of observers is divided into the number of observers, the divisibility of efforts for search, the credibility of search information and the search process. The standard of optimality is divided into the maximum probability of detection, the minimum risk expected and the others. Each item written above of search model is explained. Concerning the formulation of the search model, the theoretical equations for detection probability, discovery potential and instantaneous detection probability, density are derived, and these equations are evaluated and explained. The future plan is to advance the search technology so as to evaluate the detection potential to decide the route of running a monitoring car for a nuclear power plant at accidental condition. (Nakai, Y.)

The philosophy of space and time

CERN Document Server

Reichenbach, Hans

1958-01-01

With unusual depth and clarity, the author covers the problem of the foundations of geometry, the theory of time, the theory and consequences of Einstein's relativity including: relations between theory and observations, coordinate definitions, relations between topological and metrical properties of space, the psychological problem of the possibility of a visual intuition of non-Euclidean structures, and many other important topics in modern science and philosophy. While some of the book utilizes mathematics of a somewhat advanced nature, the exposition is so careful and complete that most people familiar with the philosophy of science or some intermediate mathematics will understand the majority of the ideas and problems discussed. Partial contents: I. The Problem of Physical Geometry. Universal and Differential Forces. Visualization of Geometries. Spaces with non-Euclidean Topological Properties. Geometry as a Theory of Relations. II. The Difference between Space and Time. Simultaneity. Time Order. Unreal ...

Collaborative Approaches in Developing Environmental and Safety Management Systems for Commercial Space Transportation

Science.gov (United States)

Zee, Stacey; Murray, D.

2009-01-01

The Federal Aviation Administration (FAA), Office of Commercial Space Transportation (AST) licenses and permits U.S. commercial space launch and reentry activities, and licenses the operation of non-federal launch and reentry sites. ASTs mission is to ensure the protection of the public, property, and the national security and foreign policy interests of the United States during commercial space transportation activities and to encourage, facilitate, and promote U.S. commercial space transportation. AST faces unique challenges of ensuring the protection of public health and safety while facilitating and promoting U.S. commercial space transportation. AST has developed an Environmental Management System (EMS) and a Safety Management System (SMS) to help meet its mission. Although the EMS and SMS were developed independently, the systems share similar elements. Both systems follow a Plan-Do-Act-Check model in identifying potential environmental aspects or public safety hazards, assessing significance in terms of severity and likelihood of occurrence, developing approaches to reduce risk, and verifying that the risk is reduced. This paper will describe the similarities between ASTs EMS and SMS elements and how AST is building a collaborative approach in environmental and safety management to reduce impacts to the environment and risks to the public.

Space-time description of hard processes

International Nuclear Information System (INIS)

Ioffe, B.L.; Khoze, V.A.; Lipatov, L.N.

1984-01-01

The authors show that the interaction in deep inelastic scattering processes occurs mainly in a region near the light cone. It is concluded that in all cases studied, the scaling behaviour of the structure functions corresponds to the same light cone singularities of the coordinate functions as in the case of scattering on a free spin-1/2 fermion (or, perhaps, on a spinless boson). (Auth.)

Man in space - A time for perspective. [crew performance on Space Shuttle-Spacelab program

Science.gov (United States)

Winter, D. L.

1975-01-01

Factors affecting crew performances in long-term space flights are examined with emphasis on the Space Shuttle-Spacelab program. Biomedical investigations carried out during four Skylab missions indicate that initially rapid changes in certain physiological parameters, notably in cardiovascular response and red-blood-cell levels, lead to an adapted condition. Calcium loss remains a potential problem. Space Shuttle environmental control and life-support systems are described together with technology facilitating performance of mission objectives in a weightless environment. It is concluded that crew requirements are within the physical and psychological capability of astronauts, but the extent to which nonastronaut personnel will be able to participate without extensive training and pre-conditioning remains to be determined.

The HAL 9000 Space Operating System Real-Time Planning Engine Design and Operations Requirements

Science.gov (United States)

Stetson, Howard; Watson, Michael D.; Shaughnessy, Ray

2012-01-01

In support of future deep space manned missions, an autonomous/automated vehicle, providing crew autonomy and an autonomous response planning system, will be required due to the light time delays in communication. Vehicle capabilities as a whole must provide for tactical response to vehicle system failures and space environmental effects induced failures, for risk mitigation of permanent loss of communication with Earth, and for assured crew return capabilities. The complexity of human rated space systems and the limited crew sizes and crew skills mix drive the need for a robust autonomous capability on-board the vehicle. The HAL 9000 Space Operating System[2] designed for such missions and space craft includes the first distributed real-time planning / re-planning system. This paper will detail the software architecture of the multiple planning engine system, and the interface design for plan changes, approval and implementation that is performed autonomously. Operations scenarios will be defined for analysis of the planning engines operations and its requirements for nominal / off nominal activities. An assessment of the distributed realtime re-planning system, in the defined operations environment, will be provided as well as findings as it pertains to the vehicle, crew, and mission control requirements needed for implementation.

Real-Time Smart Tools for Processing Spectroscopy Data, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose novel and real-time smart software tools to process spectroscopy data. Material abundance or compositional maps will be generated for rover guidance,...

Unitary quantum physics with time-space non-commutativity

International Nuclear Information System (INIS)

Balachandran, A P; Govindarajan, T R; Martins, A G; Molina, C; Teotonio-Sobrinho, P

2005-01-01

In these lectures 4 quantum physics in noncommutative spacetime is developed. It is based on the work of Doplicher et al. which allows for time-space noncommutativity. In the context of noncommutative quantum mechanics, some important points are explored, such as the formal construction of the theory, symmetries, causality, simultaneity and observables. The dynamics generated by a noncommutative Schroedinger equation is studied. The theory is further extended to certain noncommutative versions of the cylinder, R 3 and R x S 3 . In all these models, only discrete time translations are possible. One striking consequence of quantised time translations is that even though a time independent Hamiltonian is an observable, in scattering processes, it is conserved only modulo 2π/θ, where θ is the noncommutative parameter. Scattering theory is formulated and an approach to quantumfield theory is outlined

Magnetic Nanotweezers for Interrogating Biological Processes in Space and Time.

Science.gov (United States)

Kim, Ji-Wook; Jeong, Hee-Kyung; Southard, Kaden M; Jun, Young-Wook; Cheon, Jinwoo

2018-04-17

The ability to sense and manipulate the state of biological systems has been extensively advanced during the past decade with the help of recent developments in physical tools. Unlike standard genetic and pharmacological perturbation techniques-knockdown, overexpression, small molecule inhibition-that provide a basic on/off switching capability, these physical tools provide the capacity to control the spatial, temporal, and mechanical properties of the biological targets. Among the various physical cues, magnetism offers distinct advantages over light or electricity. Magnetic fields freely penetrate biological tissues and are already used for clinical applications. As one of the unique features, magnetic fields can be transformed into mechanical stimuli which can serve as a cue in regulating biological processes. However, their biological applications have been limited due to a lack of high-performance magnetism-to-mechanical force transducers with advanced spatiotemporal capabilities. In this Account, we present recent developments in magnetic nanotweezers (MNTs) as a useful tool for interrogating the spatiotemporal control of cells in living tissue. MNTs are composed of force-generating magnetic nanoparticles and field generators. Through proper design and the integration of individual components, MNTs deliver controlled mechanical stimulation to targeted biomolecules at any desired space and time. We first discuss about MNT configuration with different force-stimulation modes. By modulating geometry of the magnetic field generator, MNTs exert pulling, dipole-dipole attraction, and rotational forces to the target specifically and quantitatively. We discuss the key physical parameters determining force magnitude, which include magnetic field strength, magnetic field gradient, magnetic moment of the magnetic particle, as well as distance between the field generator and the particle. MNTs also can be used over a wide range of biological time scales. By simply

Space-time reference with an optical link

International Nuclear Information System (INIS)

Berceau, P; Hollberg, L; Taylor, M; Kahn, J

2016-01-01

We describe a concept for realizing a high performance space-time reference using a stable atomic clock in a precisely defined orbit and synchronizing the orbiting clock to high-accuracy atomic clocks on the ground. The synchronization would be accomplished using a two-way lasercom link between ground and space. The basic approach is to take advantage of the highest-performance cold-atom atomic clocks at national standards laboratories on the ground and to transfer that performance to an orbiting clock that has good stability and that serves as a ‘frequency-flywheel’ over time-scales of a few hours. The two-way lasercom link would also provide precise range information and thus precise orbit determination. With a well-defined orbit and a synchronized clock, the satellite could serve as a high-accuracy space-time reference, providing precise time worldwide, a valuable reference frame for geodesy, and independent high-accuracy measurements of GNSS clocks. Under reasonable assumptions, a practical system would be able to deliver picosecond timing worldwide and millimeter orbit determination, and could serve as an enabling subsystem for other proposed space-gravity missions, which are briefly reviewed. (paper)

Quantum space-times in the year 2002

Indian Academy of Sciences (India)

These ideas of space-time are suggested from developments in fuzzy physics, string theory, and deformation quantization. The review focuses on the ideas coming from fuzzy physics. We find models of quantum space-time like fuzzy 4 on which states cannot be localized, but which fluctuate into other manifolds like CP3.

Methods utilized in evaluating the profitability of commercial space processing

Science.gov (United States)

Bloom, H. L.; Schmitt, P. T.

1976-01-01

Profitability analysis is applied to commercial space processing on the basis of business concept definition and assessment and the relationship between ground and space functions. Throughput analysis is demonstrated by analysis of the space manufacturing of surface acoustic wave devices. The paper describes a financial analysis model for space processing and provides key profitability measures for space processed isoenzymes.

A short history of fractal-Cantorian space-time

International Nuclear Information System (INIS)

Marek-Crnjac, L.

2009-01-01

The article attempts to give a short historical overview of the discovery of fractal-Cantorian space-time starting from the 17th century up to the present. In the last 25 years a great number of scientists worked on fractal space-time notably Garnet Ord in Canada, Laurent Nottale in France and Mohamed El Naschie in England who gave an exact mathematical procedure for the derivation of the dimensionality and curvature of fractal space-time fuzzy manifold.

Two-Dimensional Space-Time Analysis and Matrix Represen-Tation on the Principle of the Capacitive Displacement Transducer

Energy Technology Data Exchange (ETDEWEB)

Zhang, Z Y [College of Metrological Technology and Engineering, China Jiliang University, Hangzhou (China); Luo, J X [Zhejiang Radio Factory, Zhejiang (China)

2006-10-15

In order to provide a design method of the capacitive displacement transducer and to improve its measuring performance it is desperately needed to offer a refined mathematic model of the transducer of mulitiphase drive and phase-modulated. On the basis of fully considering its characteristic of digital signals, first it is found that their actual waveforms and space-time characteristics could be tersely represented by matrixes [u{sub ij}], [c{sub j}] and [v{sub i}], and corresponding matrix elements u{sub ij}, c{sub j} and v{sub i} through deeply analyzing space-time and quantum characteristics of their mulitiphase driving signals U{sub i}(t), capacitive coupling signals C{sub j}(x) and output signal V(t). and space-time transform function possessed by U(x,t) itself. Then the basic expression of the relations of the transducer is derived, which is expressed by matrixes, thereby the characteristics of space-time transform and phase modulation are brought to light. The demodulation process and demodulated waveforms and its characteristics in the transducer are also expressed by demodulated matrixes [b{sub ij}]. Finally, the reason for the principle and periodic error produced in the transducer is revealed by sampling matrix [s{sub ij}]. Thus the full process of the produce of driving signals, modulation, demodulation and space-time transform that happen in the transducer, also waveforms and characteristics of various signals in the process are concisely expressed by two-dimensional space-time matrixes. Experimental results indicate that the use of the mathematical model enables its resolving power to reach 1 {mu}m, and the mathematical model proposed is an all-things-considered model to express processes that happen in the transducer.

The technology management process at the European space agency

Science.gov (United States)

Guglielmi, M.; Williams, E.; Groepper, P.; Lascar, S.

2010-03-01

Technology is developed at the European Space Agency (ESA) under several programmes: corporate and domain specific, mandatory and optional, with different time horizons and covering different levels of the TRL scale. To improve the transparency and efficiency of the complete process, it was felt necessary to establish an agreed end to end process for the management of all technology R&D activity that could: Include all ESA programmes and consider the requirements of European users Lead to coordinated multi-year work plan and yearly procurement plans Prepare and enable future European space programmes Be harmonized with national initiatives in Europe Thereby establishing the basis for a product policy to reduce risks to technology users, reduce costs and delays, and enhance industrial competitiveness and non-dependence. In response to the above needs, ESA has developed a technology management process called the ESA End-to-End process (E2E), from establishment of the strategy to the monitoring and evaluation of R&D results. In this paper, the complete process will be described in detail including a discussion on its strengths and limitations, and its links to the wider European Harmonization process. The paper will be concluded with the introduction of the ESA Technology Tree: a basic tool to structure and facilitate communication about technology issues.

High Resolution Near Real Time Image Processing and Support for MSSS Modernization

Science.gov (United States)

Duncan, R. B.; Sabol, C.; Borelli, K.; Spetka, S.; Addison, J.; Mallo, A.; Farnsworth, B.; Viloria, R.

2012-09-01

This paper describes image enhancement software applications engineering development work that has been performed in support of Maui Space Surveillance System (MSSS) Modernization. It also includes R&D and transition activity that has been performed over the past few years with the objective of providing increased space situational awareness (SSA) capabilities. This includes Air Force Research Laboratory (AFRL) use of an FY10 Dedicated High Performance Investment (DHPI) cluster award -- and our selection and planned use for an FY12 DHPI award. We provide an introduction to image processing of electro optical (EO) telescope sensors data; and a high resolution image enhancement and near real time processing and summary status overview. We then describe recent image enhancement applications development and support for MSSS Modernization, results to date, and end with a discussion of desired future development work and conclusions. Significant improvements to image processing enhancement have been realized over the past several years, including a key application that has realized more than a 10,000-times speedup compared to the original R&D code -- and a greater than 72-times speedup over the past few years. The latest version of this code maintains software efficiency for post-mission processing while providing optimization for image processing of data from a new EO sensor at MSSS. Additional work has also been performed to develop low latency, near real time processing of data that is collected by the ground-based sensor during overhead passes of space objects.

The algebraic approach to space-time geometry

International Nuclear Information System (INIS)

Heller, M.; Multarzynski, P.; Sasin, W.

1989-01-01

A differential manifold can be defined in terms of smooth real functions carried by it. By rejecting the postulate, in such a definition, demanding the local diffeomorphism of a manifold to the Euclidean space, one obtains the so-called differential space concept. Every subset of R n turns out to be a differential space. Extensive parts of differential geometry on differential spaces, developed by Sikorski, are reviewed and adapted to relativistic purposes. Differential space as a new model of space-time is proposed. The Lorentz structure and Einstein's field equations on differential spaces are discussed. 20 refs. (author)

Quantum field theory in flat Robertson-Walker space-time functional Schrodinger picture

International Nuclear Information System (INIS)

Pi, S.Y.

1990-01-01

Quantum field theory in Robertson-Walker space-time is intrinsically time-dependent and the functional Schrodinger picture provides a useful description. This paper discusses free and self-interacting bosonic quantum field theories: Schrodinger picture quantization, time-dependent Gaussian approximations based on variational principles describing time evolution of pure and mixed states, and renormalizability of the Schrodinger picture. The technique introduced can be used to study various dynamical questions in early universe processes

Quantum field theory in flat Robertson-Walker space-time functional Schroedinger picture

International Nuclear Information System (INIS)

Pi, S.Y.

1989-01-01

Quantum field theory in Robertson-Walker space-time is intrinsically time-dependent and the functional Schroedinger picture provides a useful description. We discuss free and self-interacting bosonic quantum field theories: Schroedinger picture quantization, time-dependent Gaussian approximations based on variational principles describing time evolution of pure and mixed states, and renormalizability of the Schroedinger picture. The techniques introduced can be used to study various dynamical questions in early universe processes. (author)

Scattering theory of space-time non-commutative abelian gauge field theory

International Nuclear Information System (INIS)

Rim, Chaiho; Yee, Jaehyung

2005-01-01

The unitary S-matrix for space-time non-commutative quantum electrodynamics is constructed using the *-time ordering which is needed in the presence of derivative interactions. Based on this S-matrix, we formulate the perturbation theory and present the Feynman rule. We then apply this perturbation analysis to the Compton scattering process to the lowest order and check the gauge invariance of the scattering amplitude at this order.

DEVELOPMENT OF INNOVATIVE PROCESSES IN THE COMPANIES OF SPACE INDUSTRY

Directory of Open Access Journals (Sweden)

Katrina B. Dobrova

2016-01-01

Full Text Available In this article, the proposals to improve the theoretical and methodological base for the development of innovative technologies aerospace industry are made based on an analysis of its current state and the study of the factors influencing this process at every stage, as well as the goals and objectives of the modernization of the Russian economy. The relevance of the study due to the fact that the rocket and space industry is regarded as an important component of sustainable socio-economic development and a guarantee of national security. Having our own space rocket means significantly promotes sound public policy in accordance with the doctrines, strategies, concepts and programs in the political, economic, social, military, environmental, scientific, technological, information and other fields. It was noted that the study of features of the commercialization of innovative technologies of the Russian Federation, the space industry is crucial to determine the factors and conditions for successful implementation of the development industry, the search of promising directions of development of the space industry and the economy as a whole. Emphasis is placed on the formation of the basic elements of innovation infrastructure and the creation of effective mechanisms of commercialization, creation of actual operating business on their basis, investment in the development of the aerospace industry, including using the tools of public-private partnerships and venture financing.

Environmental Impact Analysis Process. Environmental Impact Statement Space Shuttle Program Vandenberg AFB, California

Science.gov (United States)

1978-01-01

MAIMIEOIR, NATIUM L FEATURES TO BE ALTERED: Nost applicable. EMISSIONS: .• Operational: Space Shuttle main eagin. and SolidRocket Roast r exhaust. 414...symptom. (50) (2) From animal studies" (a) Bobwhite quail and domestic chicken eggs displayed a 50 percent mortality rate upon a single 15-minute exposure...t In another planned study (as opposed to casual observation) chicken eggs were exposed to about 30 sonic booms per day during incubation; median

Occupy: New Pedagogy of Space and Time?

Directory of Open Access Journals (Sweden)

Sarah Amsler

2015-12-01

Full Text Available This paper forms the first part of a project of inquiry to understand the theoretical and practical potentials of Occupy through the recent wave of occupations that have emerged in response to the politics of austerity and precarity around the world. We do this as educators who are seeking to ‘occupy’ spaces of higher education inside and outside of the institutions in which we work. Occupy points to the centrality of space and time as practical concepts through which it is possible to reconfigure revolutionary activity. By dealing with the concept (Occupy at this fundamental level of space and time through a critical engagement with Henri Lefebvre’s notion of ‘a new pedagogy of space and time’, we hope to open spaces for further revolutionary transformation by extending a critique of the politics of space and time into the institutions and idea of education itself. Lefebvre considers the ‘pedagogy of space and time’ as a basis for a new form of ‘counter-space’. He suggests that ‘deviant or diverted spaces, though initially subordinate, show distinct evidence of a true productive capacity’ (2008: 383, and in doing so reveal the breaking points of everyday life and the ways in which it might be appropriated as exuberant spaces full of enjoyment and hope. In the Production of Space, he identifies the space of leisure as a site within which such a resistance might be contemplated and activated. In our work we replace the principle of leisure with the concept of Occupy. We consider here how attempts to occupy the university curriculum, not as a programme of education but as the production of critical knowledge, may also constitute ‘a new pedagogy of space and time’. We will describe this occupation of higher education with reference to two projects with which we are involved Student as Producer and the Social Science Centre, the former at the University of Lincoln, and the latter across the city of Lincoln.

Convexity and the Euclidean Metric of Space-Time

Directory of Open Access Journals (Sweden)

Nikolaos Kalogeropoulos

2017-02-01

Full Text Available We address the reasons why the “Wick-rotated”, positive-definite, space-time metric obeys the Pythagorean theorem. An answer is proposed based on the convexity and smoothness properties of the functional spaces purporting to provide the kinematic framework of approaches to quantum gravity. We employ moduli of convexity and smoothness which are eventually extremized by Hilbert spaces. We point out the potential physical significance that functional analytical dualities play in this framework. Following the spirit of the variational principles employed in classical and quantum Physics, such Hilbert spaces dominate in a generalized functional integral approach. The metric of space-time is induced by the inner product of such Hilbert spaces.

Transport processes in space physics and astrophysics

CERN Document Server

Zank, Gary P

2014-01-01

Transport Processes in Space Physics and Astrophysics' is aimed at graduate level students to provide the necessary mathematical and physics background to understand the transport of gases, charged particle gases, energetic charged particles, turbulence, and radiation in an astrophysical and space physics context. Subjects emphasized in the work include collisional and collisionless processes in gases (neutral or plasma), analogous processes in turbulence fields and radiation fields, and allows for a simplified treatment of the statistical description of the system. A systematic study that addresses the common tools at a graduate level allows students to progress to a point where they can begin their research in a variety of fields within space physics and astrophysics. This book is for graduate students who expect to complete their research in an area of plasma space physics or plasma astrophysics. By providing a broad synthesis in several areas of transport theory and modeling, the work also benefits resear...

ENFORMASYON ÇAĞI – ZAMAN – MEKÂN İLİŞKİSİ BAĞLAMINDA BÖLGESEL KALKINMA KURAM VE SÜREÇLERİ / REGIONAL DEVELOPMENT THEORIES AND PROCESSES IN THE CONTEXT OF INFORMATION AGE– TIME & SPACE RELATIONSHIP

Directory of Open Access Journals (Sweden)

Pervin ŞENOL

2018-05-01

Full Text Available EXTENDED SUMMARY Research Purpose: The purpose of this essay is to evaluate how the concepts of time and space have transformed in theories of economics, regional development paradigm and location theories from the 18th century to nowadays. Research Questions: From the mercantilist period to the nowadays, what kind of transformations have occurred in economic theories, development economy and regional development theories in terms of time and space conceptual aspects? How have been transformed time and space context of theories of location from von Thünen to Krugman established? How did Manuel Castells relate to time and space in the Age of Information? Literature Review: This essay data based on literature search which include books, academic journals, internet resources and Google Academic database. Key elements and keywords of this search are economic theories, regional development paradigms, time-space relations in theories, location theories, as well as Manuel Castells’s works on time and space concepts such as Information Age book. Results and Conclusions: Before Industrial Revolutioan mercantilist periods of economic system time and space had defined as a natural processes determined by nature and natural conditions. Industrial Revolution (1st, 2nd and 3rd stages, Enlightenment, rational thought together with technological innovation changed the concepts of time and space, and its organization especially in the production processes include labor force, mode of production, production relations so on. It seems that space and time concepts have been used as an abstract and ignored component of the capital accumulation process in the economic theories, regional development theories (location theories etc.. Fourth stage of Industrial Revolution has started to new era for time and space with the creative industries, internet of things and the information technology. Theoretical approaches in the world and Turkey, countries, geography (space

Spontaneous symmetry breaking in curved space-time

International Nuclear Information System (INIS)

Toms, D.J.

1982-01-01

An approach dealing with some of the complications which arise when studying spontaneous symmetry breaking beyond the tree-graph level in situations where the effective potential may not be used is discussed. These situations include quantum field theory on general curved backgrounds or in flat space-times with non-trivial topologies. Examples discussed are a twisted scalar field in S 1 xR 3 and instabilities in an expanding universe. From these it is seen that the topology and curvature of a space-time may affect the stability of the vacuum state. There can be critical length scales or times beyond which symmetries may be broken or restored in certain cases. These features are not present in Minkowski space-time and so would not show up in the usual types of early universe calculations. (U.K.)

Pre-Big Bang, space-time structure, asymptotic Universe

Directory of Open Access Journals (Sweden)

Gonzalez-Mestres Luis

2014-04-01

Full Text Available Planck and other recent data in Cosmology and Particle Physics can open the way to controversial analyses concerning the early Universe and its possible ultimate origin. Alternatives to standard cosmology include pre-Big Bang approaches, new space-time geometries and new ultimate constituents of matter. Basic issues related to a possible new cosmology along these lines clearly deserve further exploration. The Planck collaboration reports an age of the Universe t close to 13.8 Gyr and a present ratio H between relative speeds and distances at cosmic scale around 67.3 km/s/Mpc. The product of these two measured quantities is then slightly below 1 (about 0.95, while it can be exactly 1 in the absence of matter and cosmological constant in patterns based on the spinorial space-time we have considered in previous papers. In this description of space-time we first suggested in 1996-97, the cosmic time t is given by the modulus of a SU(2 spinor and the Lundmark-Lemaître-Hubble (LLH expansion law turns out to be of purely geometric origin previous to any introduction of standard matter and relativity. Such a fundamental geometry, inspired by the role of half-integer spin in Particle Physics, may reflect an equilibrium between the dynamics of the ultimate constituents of matter and the deep structure of space and time. Taking into account the observed cosmic acceleration, the present situation suggests that the value of 1 can be a natural asymptotic limit for the product H t in the long-term evolution of our Universe up to possible small corrections. In the presence of a spinorial space-time geometry, no ad hoc combination of dark matter and dark energy would in any case be needed to get an acceptable value of H and an evolution of the Universe compatible with observation. The use of a spinorial space-time naturally leads to unconventional properties for the space curvature term in Friedmann-like equations. It therefore suggests a major modification of

Quantum field theory in curved space-time

International Nuclear Information System (INIS)

Najmi, A.-H.

1982-09-01

The problem of constructing states for quantum field theories in nonstationary background space-times is set out. A formalism in which the problem of constructing states can be attacked more easily than at present is presented. The ansatz of energy-minimization as a means of constructing states is formulated in this formalism and its general solution for the free scalar field is found. It has been known, in specific cases, that such states suffer from the problem of unitary inequivalence (the pathology). An example in Minowski space-time is presented in which global operators, such as the particle-number operator, do not exist but all physical observables, such as the renormalized energy density are finite. This model has two Fock-sectors as its space of physical states. A simple extension of this model, i.e. enlarging the Fock-space of states is found not to remedy the pathology: in a Robertson-Walker space-time the quantum field acquires an infinite amount of renormalized energy density to the future of the hypersurface on which the energy density is minimized. Finally, the solution of the ansatz of energy minimization for the free, massive Hermitian fermion field is presented. (author)

Cost-time management for environmental restoration activities at the Department of Energy's Idaho National Engineering Laboratory, Idaho Chemical Processing Plant

International Nuclear Information System (INIS)

Fourr, B.R.; Owen, A.H.; Williamson, D.J.; Nash, C.L.

1992-01-01

Cost-time management methods have been developed by Westinghouse to examine business applications from a cost-time perspective. The initial application of cost-time management within Westinghouse was targeted at reducing cycle time in the manufacturing sector. As a result of the tremendous success of reduced cycle time in manufacturing, Westinghouse initiated application of the management technique to Environmental Restoration activities at its Government Owned Contractor Operated facilities. The Westinghouse initiative was proposed in support of the Department of Energy's goals for cost effective Environmental Restoration activities. This paper describes the application of the cost-time method to Environmental Restoration work currently being performed at the Idaho National Engineering Laboratory (INEL) for the Department of Energy (DOE) by Westinghouse Idaho Nuclear Company (WINCO)

A composite model of the space-time and 'colors'

International Nuclear Information System (INIS)

Terazawa, Hidezumi.

1987-03-01

A pregeometric and pregauge model of the space-time and ''colors'' in which the space-time metric and ''color'' gauge fields are both composite is presented. By the non-triviality of the model, the number of space-time dimensions is restricted to be not larger than the number of ''colors''. The long conjectured space-color correspondence is realized in the model action of the Nambu-Goto type which is invariant under both general-coordinate and local-gauge transformations. (author)

Space-Time Code Designs for Broadband Wireless Communications

National Research Council Canada - National Science Library

Xia, Xiang-Gen

2005-01-01

The goal of this research is to design new space AND time codes, such as complex orthogonal space AND time block codes with rate above 1/2 from complex orthogonal designs for QAM, PSK, and CPM signals...

Exploring space-time structure of human mobility in urban space

Science.gov (United States)

Sun, J. B.; Yuan, J.; Wang, Y.; Si, H. B.; Shan, X. M.

2011-03-01

Understanding of human mobility in urban space benefits the planning and provision of municipal facilities and services. Due to the high penetration of cell phones, mobile cellular networks provide information for urban dynamics with a large spatial extent and continuous temporal coverage in comparison with traditional approaches. The original data investigated in this paper were collected by cellular networks in a southern city of China, recording the population distribution by dividing the city into thousands of pixels. The space-time structure of urban dynamics is explored by applying Principal Component Analysis (PCA) to the original data, from temporal and spatial perspectives between which there is a dual relation. Based on the results of the analysis, we have discovered four underlying rules of urban dynamics: low intrinsic dimensionality, three categories of common patterns, dominance of periodic trends, and temporal stability. It implies that the space-time structure can be captured well by remarkably few temporal or spatial predictable periodic patterns, and the structure unearthed by PCA evolves stably over time. All these features play a critical role in the applications of forecasting and anomaly detection.

The space technology demand on materials and processes

Science.gov (United States)

Dauphin, J.

1983-01-01

Space technology requires a rational and accurate policy of materials and processes selection. This paper examines some areas of space technology where materials and process problems have occurred in the past and how they can be solved in the future.

Distributed space-time coding

CERN Document Server

Jing, Yindi

2014-01-01

Distributed Space-Time Coding (DSTC) is a cooperative relaying scheme that enables high reliability in wireless networks. This brief presents the basic concept of DSTC, its achievable performance, generalizations, code design, and differential use. Recent results on training design and channel estimation for DSTC and the performance of training-based DSTC are also discussed.

Warped product space-times

Science.gov (United States)

An, Xinliang; Wong, Willie Wai Yeung

2018-01-01

Many classical results in relativity theory concerning spherically symmetric space-times have easy generalizations to warped product space-times, with a two-dimensional Lorentzian base and arbitrary dimensional Riemannian fibers. We first give a systematic presentation of the main geometric constructions, with emphasis on the Kodama vector field and the Hawking energy; the construction is signature independent. This leads to proofs of general Birkhoff-type theorems for warped product manifolds; our theorems in particular apply to situations where the warped product manifold is not necessarily Einstein, and thus can be applied to solutions with matter content in general relativity. Next we specialize to the Lorentzian case and study the propagation of null expansions under the assumption of the dominant energy condition. We prove several non-existence results relating to the Yamabe class of the fibers, in the spirit of the black-hole topology theorem of Hawking–Galloway–Schoen. Finally we discuss the effect of the warped product ansatz on matter models. In particular we construct several cosmological solutions to the Einstein–Euler equations whose spatial geometry is generally not isotropic.

SCALABLE TIME SERIES CHANGE DETECTION FOR BIOMASS MONITORING USING GAUSSIAN PROCESS

Data.gov (United States)

National Aeronautics and Space Administration — SCALABLE TIME SERIES CHANGE DETECTION FOR BIOMASS MONITORING USING GAUSSIAN PROCESS VARUN CHANDOLA AND RANGA RAJU VATSAVAI Abstract. Biomass monitoring,...

International Space Station Environmental Control and Life Support System Status: 2009 - 2010

Science.gov (United States)

Williams, David E.; Dake, Jason R.; Gentry, Gregory J.

2010-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non -regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year, covering the period of time between March 2009 and February 2010. The ISS continued permanent crew operations, with the start of Phase 3 of the ISS Assembly Sequence and an increase of the ISS crew size from three to six. Work continues on the last of the Phase 3 pressurized elements.

International Space Station Environmental Control and Life Support System Status: 2014-2015

Science.gov (United States)

Williams, David E.; Gentry, Gregory J.

2015-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year and the impacts of the international partners' activities on them, covering the period of time between March 2014 and February 2015. The ISS continued permanent crew operations including the continuation of six crew members being on ISS. Work continues on the commercial crew vehicles, and work to try and extend ISS service life.

Importance of neutral processes varies in time and space: Evidence from dryland stream ecosystems.

Directory of Open Access Journals (Sweden)

Xiaoli Dong

Full Text Available Many ecosystems experience strong temporal variability in environmental conditions; yet, a clear picture of how niche and neutral processes operate to determine community assembly in temporally variable systems remains elusive. In this study, we constructed neutral metacommunity models to assess the relative importance of neutral processes in a spatially and temporally variable ecosystem. We analyzed macroinvertebrate community data spanning multiple seasons and years from 20 sites in a Sonoran Desert river network in Arizona. The model goodness-of-fit was used to infer the importance of neutral processes. Averaging over eight stream flow conditions across three years, we found that neutral processes were more important in perennial streams than in non-perennial streams (intermittent and ephemeral streams. Averaging across perennial and non-perennial streams, we found that neutral processes were more important during very high flow and in low flow periods; whereas, at very low flows, the relative importance of neutral processes varied greatly. These findings were robust to the choice of model parameter values. Our study suggested that the net effect of disturbance on the relative importance of niche and neutral processes in community assembly varies non-monotonically with the severity of disturbance. In contrast to the prevailing view that disturbance promotes niche processes, we found that neutral processes could become more important when the severity of disturbance is beyond a certain threshold such that all organisms are adversely affected regardless of their biological traits and strategies.

State-space prediction model for chaotic time series

Science.gov (United States)

Alparslan, A. K.; Sayar, M.; Atilgan, A. R.

1998-08-01

A simple method for predicting the continuation of scalar chaotic time series ahead in time is proposed. The false nearest neighbors technique in connection with the time-delayed embedding is employed so as to reconstruct the state space. A local forecasting model based upon the time evolution of the topological neighboring in the reconstructed phase space is suggested. A moving root-mean-square error is utilized in order to monitor the error along the prediction horizon. The model is tested for the convection amplitude of the Lorenz model. The results indicate that for approximately 100 cycles of the training data, the prediction follows the actual continuation very closely about six cycles. The proposed model, like other state-space forecasting models, captures the long-term behavior of the system due to the use of spatial neighbors in the state space.

Space, time and the limits of human understanding

CERN Document Server

Ghirardi, Giancarlo

2017-01-01

In this compendium of essays, some of the world’s leading thinkers discuss their conceptions of space and time, as viewed through the lens of their own discipline. With an epilogue on the limits of human understanding, this volume hosts contributions from six or more diverse fields. It presumes only rudimentary background knowledge on the part of the reader. Time and again, through the prism of intellect, humans have tried to diffract reality into various distinct, yet seamless, atomic, yet holistic, independent, yet interrelated disciplines and have attempted to study it contextually. Philosophers debate the paradoxes, or engage in meditations, dialogues and reflections on the content and nature of space and time. Physicists, too, have been trying to mold space and time to fit their notions concerning micro- and macro-worlds. Mathematicians focus on the abstract aspects of space, time and measurement. While cognitive scientists ponder over the perceptual and experiential facets of our consciousness of spac...

A Conceptual Model of the Cognitive Processing of Environmental Distance Information

Science.gov (United States)

Montello, Daniel R.

I review theories and research on the cognitive processing of environmental distance information by humans, particularly that acquired via direct experience in the environment. The cognitive processes I consider for acquiring and thinking about environmental distance information include working-memory, nonmediated, hybrid, and simple-retrieval processes. Based on my review of the research literature, and additional considerations about the sources of distance information and the situations in which it is used, I propose an integrative conceptual model to explain the cognitive processing of distance information that takes account of the plurality of possible processes and information sources, and describes conditions under which particular processes and sources are likely to operate. The mechanism of summing vista distances is identified as widely important in situations with good visual access to the environment. Heuristics based on time, effort, or other information are likely to play their most important role when sensory access is restricted.

Real-time information and processing system for radiation protection

International Nuclear Information System (INIS)

Oprea, I.; Oprea, M.; Stoica, M.; Badea, E.; Guta, V.

1999-01-01

The real-time information and processing system has as main task to record, collect, process and transmit the radiation level and weather data, being proposed for radiation protection, environmental monitoring around nuclear facilities and for civil defence. Such a system can offer information in order to provide mapping, data base, modelling and communication and to assess the consequences of nuclear accidents. The system incorporates a number of stationary or mobile radiation monitoring equipment, weather parameter measuring station, a GIS-based information processing center and the communication network, all running on a real-time operating system. It provides the automatic data collection on-line and off-line, remote diagnostic, advanced presentation techniques, including a graphically oriented executive support, which has the ability to respond to an emergency by geographical representation of the hazard zones on the map.The system can be integrated into national or international environmental monitoring systems, being based on local intelligent measuring and transmission units, simultaneous processing and data presentation using a real-time operating system for PC and geographical information system (GIS). Such an integrated system is composed of independent applications operating under the same computer, which is capable to improve the protection of the population and decision makers efforts, updating the remote GIS data base. All information can be managed directly from the map by multilevel data retrieving and presentation by using on-line dynamic evolution of the events, environment information, evacuation optimization, image and voice processing

Distributing learning over time: the spacing effect in children's acquisition and generalization of science concepts.

Science.gov (United States)

Vlach, Haley A; Sandhofer, Catherine M

2012-01-01

The spacing effect describes the robust finding that long-term learning is promoted when learning events are spaced out in time rather than presented in immediate succession. Studies of the spacing effect have focused on memory processes rather than for other types of learning, such as the acquisition and generalization of new concepts. In this study, early elementary school children (5- to 7-year-olds; N = 36) were presented with science lessons on 1 of 3 schedules: massed, clumped, and spaced. The results revealed that spacing lessons out in time resulted in higher generalization performance for both simple and complex concepts. Spaced learning schedules promote several types of learning, strengthening the implications of the spacing effect for educational practices and curriculum. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.

Conserved quantities for stationary Einstein-Maxwell space-times

International Nuclear Information System (INIS)

Esposito, F.P.; Witten, L.

1978-01-01

It is shown that every stationary Einstein-Maxwell space-time has eight divergence-free vector fields and these are isolated in general form. The vector fields and associated conserved quantities are calculated for several families of space-times. (Auth.)

Approaching space-time through velocity in doubly special relativity

International Nuclear Information System (INIS)

Aloisio, R.; Galante, A.; Grillo, A.F.; Luzio, E.; Mendez, F.

2004-01-01

We discuss the definition of velocity as dE/d vertical bar p vertical bar, where E, p are the energy and momentum of a particle, in doubly special relativity (DSR). If this definition matches dx/dt appropriate for the space-time sector, then space-time can in principle be built consistently with the existence of an invariant length scale. We show that, within different possible velocity definitions, a space-time compatible with momentum-space DSR principles cannot be derived

Geodesics in Goedel-type space-times

International Nuclear Information System (INIS)

Calvao, M.O.; Soares, I.D.; Tiomno, J.

1988-01-01

The geodesic curves of the homogeneous Goedel-type space-times, which constitute a two-parameter ({ l and Ω}) class of solutions presented to several theories of gravitation (general relativity, Einstein-Cartan and higher derivative) are investigated. The qualitative properties of those curves by means of the introduction of an effective potential and then accomplish the analytical integration of the equations of motion are examined. It is shown that some of the qualitative features of the free motion in Godel's universe (l 2 =2Ω 2 ) are preserved in all space-times, namely the projections of the geodesics onto the 2-surface (r,ψ) are simple closed curves, and the geodesics for which the ratio of azymuthal angular momentum to total energy, υ is equal to zero always cross the origin r = o. However, two new cases appear: (i) radially unbounded geodesics with υ assuming any (real) value, which may occur only for the causal space-times (l 2 ≥ 4 Ω 2 ), and (ii) geodesics with υ bounded both below and above, which always occur for the circular family (l 2 [pt

Reorganising space and time:

Directory of Open Access Journals (Sweden)

Nicolas Senil

2011-07-01

Full Text Available The multiplication of objects, actors and underlying rationales of heritage development, or patrimonialisation, is increasingly blurring the strength and meaning of our relationship with the past. The aim of this article is to reflect on the processes involved in the emergence of new heritage objects and on the consequences of these developments. The article is based on a comparative analysis of two symmetric objects, both of which have been the subject of heritage development processes: the Chauvet cave and the Millau viaduct in Southern France. By showing that each object is projected in the spatial or temporal dimension from which it was a priori excluded at the time of its discovery, the analysis demonstrates the necessity of integrating a heritage approach to our understanding of territorial dynamics. The analysis suggests that the interplay of territorialisation and heritage development processes represents a reconstruction of a controlled time-space, a prerequisite for addressing a recurring problem in our society, that of its sustainability.La multiplication des objets, des acteurs et des logiques de la patrimonialisation génère un brouillage de plus en plus important sur la force et le sens de nos rapports au passé. Dans ce contexte, cet article se propose de réfléchir aux processus d’émergence de nouveaux objets patrimoniaux et aux conséquences de ces mobilisations. Il s’appuie sur l’analyse comparée de deux objets symétriques et tous deux patrimonialisés : la grotte Chauvet et le viaduc de Millau. En montrant que chaque objet est projeté dans la dimension spatiale ou temporelle dont il se trouve a priori exclu lors de son invention, l’analyse rappelle la nécessité d’intégrer une approche patrimoniale à notre lecture des dynamiques territoriales. Elle propose alors l’idée que ces mouvements croisés représentent une reconstruction d’un espace-temps maitrisé, nécessaire pour répondre au probl

Space-time structure and the origin of physical law

International Nuclear Information System (INIS)

Green, M.A.

1980-01-01

In the first part of this theses the author adopts a traditional world view, with space-time a topologically simple geometrical manifold, matter being represented by smooth classical fields, and space a Riemannian submanifold of space-time. It is shown how to characterize the space-time geometry in terms of fields defined on three-dimensional space. Accepting a finite number of the fields induced on space as independent initial data, a procedure is given for constructing dynamical and constraint equations which will propagate these fields forward in time. When the initial data are restricted to include only the hypersurface metric and the extrinsic curvature, the resulting equations combine to form the Einstein gravitational field equations with the cosmological term. The synthesis of gravitational and quantum physics is approached by proposing that the objective world underlying the perceived world is a four-dimensional topological manifold w, with no physically significant field structure and an unconstrianed and complex global topology. Conventional space-time is then a topologically simple replacement manifold for w. A preliminary outline of the correspondence is presented, based on a similarity between a natural graphical representation of 2 and the Feynman graphs of quantum field theory

We live in the quantum 4-dimensional Minkowski space-time

OpenAIRE

Hwang, W-Y. Pauchy

2015-01-01

We try to define "our world" by stating that "we live in the quantum 4-dimensional Minkowski space-time with the force-fields gauge group $SU_c(3) \\times SU_L(2) \\times U(1) \\times SU_f(3)$ built-in from the outset". We begin by explaining what "space" and "time" are meaning for us - the 4-dimensional Minkowski space-time, then proceeding to the quantum 4-dimensional Minkowski space-time. In our world, there are fields, or, point-like particles. Particle physics is described by the so-called ...

On the structure of space-time caustics

International Nuclear Information System (INIS)

Rosquist, K.

1983-01-01

Caustics formed by timelike and null geodesics in a space-time M are investigated. Care is taken to distinguish the conjugate points in the tangent space (T-conjugate points) from conjugate points in the manifold (M-conjugate points). It is shown that most nonspacelike conjugate points are regular, i.e. with all neighbouring conjugate points having the same degree of degeneracy. The regular timelike T-conjugate locus is shown to be a smooth 3-dimensional submanifold of the tangent space. Analogously, the regular null T-conjugate locus is shown to be a smooth 2-dimensional submanifold of the light cone in the tangent space. The smoothness properties of the null caustic are used to show that if an observer sees focusing in all directions, then there will necessarily be a cusp in the caustic. If, in addition, all the null conjugate points have maximal degree of degeneracy (as in the closed Friedmann-Robertson-Walker universes), then the space-time is closed. (orig.)

Realistic Goals and Processes for Future Space Astronomy Portfolio Planning

Science.gov (United States)

Morse, Jon

2015-08-01

It is generally recognized that international participation and coordination is highly valuable for maximizing the scientific impact of modern space science facilities, as well as for cost-sharing reasons. Indeed, all large space science missions, and most medium and small missions, are international, even if one country or space agency has a clear leadership role and bears most of the development costs. International coordination is a necessary aspect of future mission planning, but how that coordination is done remains debatable. I propose that the community's scientific vision is generally homogeneous enough to permit international coordination of decadal-scale strategic science goals. However, the timing and budget allocation/funding mechanisms of individual countries and/or space agencies are too disparate for effective long-term strategic portfolio planning via a single international process. Rather, I argue that coordinated space mission portfolio planning is a natural consequence of international collaboration on individual strategic missions. I review the process and outcomes of the U.S. 2010 decadal survey in astronomy & astrophysics from the perspective of a government official who helped craft the survey charter and transmitted guidance to the scientific community on behalf of a sponsoring agency (NASA), while continuing to manage the current portfolio that involved ongoing negotiations with other space agencies. I analyze the difficulties associated with projecting long-term budgets, obtaining realistic mission costs (including the additional cost burdens of international partnerships), and developing new (possibly transformational) technologies. Finally, I remark on the future role that privately funded space science missions can have in accomplishing international science community goals.

FLRW cosmology in Weyl-integrable space-time

Energy Technology Data Exchange (ETDEWEB)

Gannouji, Radouane [Department of Physics, Faculty of Science, Tokyo University of Science, 1–3, Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Nandan, Hemwati [Department of Physics, Gurukula Kangri Vishwavidayalaya, Haridwar 249404 (India); Dadhich, Naresh, E-mail: gannouji@rs.kagu.tus.ac.jp, E-mail: hntheory@yahoo.co.in, E-mail: nkd@iucaa.ernet.in [IUCAA, Post Bag 4, Ganeshkhind, Pune 411 007 (India)

2011-11-01

We investigate the Weyl space-time extension of general relativity (GR) for studying the FLRW cosmology through focusing and defocusing of the geodesic congruences. We have derived the equations of evolution for expansion, shear and rotation in the Weyl space-time. In particular, we consider the Starobinsky modification, f(R) = R+βR{sup 2}−2Λ, of gravity in the Einstein-Palatini formalism, which turns out to reduce to the Weyl integrable space-time (WIST) with the Weyl vector being a gradient. The modified Raychaudhuri equation takes the form of the Hill-type equation which is then analysed to study the formation of the caustics. In this model, it is possible to have a Big Bang singularity free cyclic Universe but unfortunately the periodicity turns out to be extremely short.

Addressing critical environmental data gaps via low-cost, real-time, cellular-based environmental monitoring

Science.gov (United States)

Caylor, K. K.; Wolf, A.; Siegfried, B.

2014-12-01

Models in the environmental sciences are repositories in a sense of the current state of understanding of critical processes. However, as our understanding of these processes (and their accompanying models) become more granular, the data requirements to parameterize them become more limiting. In addition, as these models become more useful, they are often pressed into service for decision support, meaning that they cannot accept the data latency typical of most environmental observations. Finally, the vast majority of environmental data is generated at highly-instrumented, infrastructure-rich "mega sites" in the US/Europe, while many of the most pressing environmental issues are in rural locales and in the developing world. Cellular-based environmental sensing is a promising means to provide granular data in real time from remote locales to improve model-based forecasting using data assimilation. Applications we are working on include drought forecasting and food security; forest and crop responses to weather and climate change; and rural water usage. Over the past two years, we have developed a suite of integrated hardware, firmware, and backend APIs that accommodates an unlimited variety of sensors, and propagates these data onto the internet over mobile networks. Scientific data holds a unique role for demanding well-characterized information on sensor error and our design attempts to balance error reduction with low costs. The result is a deployment system that undercuts competing commercial products by as much as 90%, allowing more ubiquitous deployment with lower risks associated with sensor loss. Enclosure design and power management are critical ingredients for remote deployments under variable environmental conditions. Sensors push data onto cloud storage and make this data available via public API's via a backend server that accommodates additional metadata essential for interpreting observations, particularly their measurement errors. The data these pods

Space-time scenarios of wind power generation produced using a Gaussian copula with parametrized precision matrix

Energy Technology Data Exchange (ETDEWEB)

Tastu, J.; Pinson, P.; Madsen, Henrik

2013-09-01

The emphasis in this work is placed on generating space-time trajectories (also referred to as scenarios) of wind power generation. This calls for prediction of multivariate densities describing wind power generation at a number of distributed locations and for a number of successive lead times. A modelling approach taking advantage of sparsity of precision matrices is introduced for the description of the underlying space-time dependence structure. The proposed parametrization of the dependence structure accounts for such important process characteristics as non-constant conditional precisions and direction-dependent cross-correlations. Accounting for the space-time effects is shown to be crucial for generating high quality scenarios. (Author)

Multi objective optimization model for minimizing production cost and environmental impact in CNC turning process

Science.gov (United States)

Widhiarso, Wahyu; Rosyidi, Cucuk Nur

2018-02-01

Minimizing production cost in a manufacturing company will increase the profit of the company. The cutting parameters will affect total processing time which then will affect the production cost of machining process. Besides affecting the production cost and processing time, the cutting parameters will also affect the environment. An optimization model is needed to determine the optimum cutting parameters. In this paper, we develop an optimization model to minimize the production cost and the environmental impact in CNC turning process. The model is used a multi objective optimization. Cutting speed and feed rate are served as the decision variables. Constraints considered are cutting speed, feed rate, cutting force, output power, and surface roughness. The environmental impact is converted from the environmental burden by using eco-indicator 99. Numerical example is given to show the implementation of the model and solved using OptQuest of Oracle Crystal Ball software. The results of optimization indicate that the model can be used to optimize the cutting parameters to minimize the production cost and the environmental impact.

A stochastic fractional dynamics model of space-time variability of rain

Science.gov (United States)

Kundu, Prasun K.; Travis, James E.

2013-09-01

varies in space and time in a highly irregular manner and is described naturally in terms of a stochastic process. A characteristic feature of rainfall statistics is that they depend strongly on the space-time scales over which rain data are averaged. A spectral model of precipitation has been developed based on a stochastic differential equation of fractional order for the point rain rate, which allows a concise description of the second moment statistics of rain at any prescribed space-time averaging scale. The model is thus capable of providing a unified description of the statistics of both radar and rain gauge data. The underlying dynamical equation can be expressed in terms of space-time derivatives of fractional orders that are adjusted together with other model parameters to fit the data. The form of the resulting spectrum gives the model adequate flexibility to capture the subtle interplay between the spatial and temporal scales of variability of rain but strongly constrains the predicted statistical behavior as a function of the averaging length and time scales. We test the model with radar and gauge data collected contemporaneously at the NASA TRMM ground validation sites located near Melbourne, Florida and on the Kwajalein Atoll, Marshall Islands in the tropical Pacific. We estimate the parameters by tuning them to fit the second moment statistics of radar data at the smaller spatiotemporal scales. The model predictions are then found to fit the second moment statistics of the gauge data reasonably well at these scales without any further adjustment.

Estimating linear temporal trends from aggregated environmental monitoring data

Science.gov (United States)

Erickson, Richard A.; Gray, Brian R.; Eager, Eric A.

2017-01-01

Trend estimates are often used as part of environmental monitoring programs. These trends inform managers (e.g., are desired species increasing or undesired species decreasing?). Data collected from environmental monitoring programs is often aggregated (i.e., averaged), which confounds sampling and process variation. State-space models allow sampling variation and process variations to be separated. We used simulated time-series to compare linear trend estimations from three state-space models, a simple linear regression model, and an auto-regressive model. We also compared the performance of these five models to estimate trends from a long term monitoring program. We specifically estimated trends for two species of fish and four species of aquatic vegetation from the Upper Mississippi River system. We found that the simple linear regression had the best performance of all the given models because it was best able to recover parameters and had consistent numerical convergence. Conversely, the simple linear regression did the worst job estimating populations in a given year. The state-space models did not estimate trends well, but estimated population sizes best when the models converged. We found that a simple linear regression performed better than more complex autoregression and state-space models when used to analyze aggregated environmental monitoring data.

Nuclear disassembly time scales using space time correlations

International Nuclear Information System (INIS)

Durand, D.; Colin, J.; Lecolley, J.F.; Meslin, C.; Aboufirassi, M.; Bougault, R.; Brou, R.; Galin, J.; and others.

1996-01-01

The lifetime, τ, with respect to multifragmentation of highly excited nuclei is deduced from the analysis of strongly damped Pb+Au collisions at 29 MeV/u. The method is based on the study of space-time correlations induced by 'proximity' effects between fragments emitted by the two primary products of the reaction and gives the time between the re-separation of the two primary products and the subsequent multifragment decay of one partner. (author)

Quantum energy-momentum tensor in space-time with time-like killing vector

International Nuclear Information System (INIS)

Frolov, V.P.; Zel'nikov, A.I.

1987-01-01

An approximate expression for the vacuum and thermal average μν > ren of the stress-energy tensor of conformal massless fields in static Ricci-flat space-times is constructed. The application of this approximation to the space-time of a Schwarzschild black hole and its relation to the Page-Brown-Ottewill approximation are briefly discussed. (orig.)

Coproduct and star product in field theories on Lie-algebra noncommutative space-times

International Nuclear Information System (INIS)

Amelino-Camelia, Giovanni; Arzano, Michele

2002-01-01

We propose a new approach to field theory on κ-Minkowski noncommutative space-time, a popular example of Lie-algebra space-time. Our proposal is essentially based on the introduction of a star product, a technique which is proving to be very fruitful in analogous studies of canonical noncommutative space-times, such as the ones recently found to play a role in the description of certain string-theory backgrounds. We find to be incorrect the expectation, previously reported in the literature, that the lack of symmetry of the κ-Poincare coproduct should lead to interaction vertices that are not symmetric under exchanges of the momenta of identical particles entering the relevant processes. We show that in κ-Minkowski the coproduct and the star product must indeed treat momenta in a nonsymmetric way, but the overall structure of interaction vertices is symmetric under exchange of identical particles. We also show that in κ-Minkowski field theories it is convenient to introduce the concepts of 'planar' and 'nonplanar' Feynman loop diagrams, again in close analogy with the corresponding concepts previously introduced in the study of field theories in canonical noncommutative space-times

Spaces of positive and negative frequency solutions of field equations in curved space--times. I. The Klein--Gordon equation in stationary space--times

International Nuclear Information System (INIS)

Moreno, C.

1977-01-01

In stationary space--times V/sub n/ x R with compact space-section manifold without boundary V/sub n/, the Klein--Gordon equation is solved by the one-parameter group of unitary operators generated by the energy operator i -1 T -1 in the Sobolev spaces H/sup l/(V/sub n/) x H/sup l/(V/sub n/). The canonical symplectic and complex structures of the associated dynamical system are calculated. The existence and the uniqueness of the Lichnerowicz kernel are established. The Hilbert spaces of positive and negative frequency-part solutions defined by means of this kernel are constructed

Space Environmental Viewing and Analysis Network (SEVAN) – characteristics and first operation results

International Nuclear Information System (INIS)

Chilingarian, Ashot; Arakelyan, Karen; Avakyan, Karen; Bostanjyan, Nikolaj; Chilingaryan, Suren; Pokhsraryan, D; Sargsyan, D; Reymers, A

2013-01-01

Space Environmental Viewing and Analysis Network is a worldwide network of identical particle detectors located at middle and low latitudes aimed to improve fundamental research of space weather conditions and to provide short- and long-term forecasts of the dangerous consequences of space storms. SEVAN detected changing fluxes of different species of secondary cosmic rays at different altitudes and latitudes, thus turning SEVAN into a powerful integrated device used to explore solar modulation effects. Till to now the SEVAN modules are installed at Aragats Space Environmental Centre in Armenia (3 units at altitudes 800, 2000 and 3200 m a.s.l.), Bulgaria (Moussala), Croatia and India (New-Delhi JNU.) and now under installation in Slovakia, LomnitskySchtit). Recently SEVAN detectors were used for research of new high-energy phenomena originated in terrestrial atmosphere – Thunderstorm Ground Enhancements (TGEs). In 2011 first joint measurements of solar modulation effects were detected by SEVAN network, now under analysis.

Space-time neutronic analysis of postulated LOCA's in CANDU reactors

International Nuclear Information System (INIS)

Luxat, J.C.; Frescura, G.M.

1978-01-01

Space-time neutronic behaviour of CANDU reactors is of importance in the analysis and design of reactor safety systems. A methodology has been developed for simulating CANDU space-time neutronics with application to the analysis of postulated LOCA'S. The approach involves the efficient use of a set of computer codes which provide a capability to perform simulations ranging from detailed, accurate 3-dimensional space-time to low-cost survey calculations using point kinetics with some ''effective'' spatial content. A new, space-time kinetics code based upon a modal expansion approach is described. This code provides an inexpensive and relatively accurate scoping tool for detailed 3-dimensional space-time simulations. (author)

Low earth orbit environmental effects on the space station photovoltaic power generation systems

International Nuclear Information System (INIS)

Nahra, H.K.

1977-01-01

A summary of the Low Earth Orbital Environment, its impact on the photovoltaic power systems of the space station and the solutions implemented to resolve the environmental concerns or issues are described. Low Earth Orbital Environment (LEO) presents several concerns to the photovoltaic power systems of the space station. These concerns include atomic oxygen interaction with the polymeric substrate of the solar arrays, ionized environment effects on the array operating voltage, the effects of the meteoroids and debris impacts and penetration through the different layers of the solar cells and their circuits, and the high energy particle and radiation effects on the overall solar array performance. Potential solutions to some of the degrading environmental interactions that will provide the photovoltaic power system of the space station with the desired life are also summarized

Nonterrestrial material processing and manufacturing of large space systems

Science.gov (United States)

Von Tiesenhausen, G.

1979-01-01

Nonterrestrial processing of materials and manufacturing of large space system components from preprocessed lunar materials at a manufacturing site in space is described. Lunar materials mined and preprocessed at the lunar resource complex will be flown to the space manufacturing facility (SMF), where together with supplementary terrestrial materials, they will be final processed and fabricated into space communication systems, solar cell blankets, radio frequency generators, and electrical equipment. Satellite Power System (SPS) material requirements and lunar material availability and utilization are detailed, and the SMF processing, refining, fabricating facilities, material flow and manpower requirements are described.

Ionospheric Response to Extremes in the Space Environment: Establishing Benchmarks for the Space Weather Action Plan.

Science.gov (United States)

Viereck, R. A.; Azeem, S. I.

2017-12-01

One of the goals of the National Space Weather Action Plan is to establish extreme event benchmarks. These benchmarks are estimates of environmental parameters that impact technologies and systems during extreme space weather events. Quantitative assessment of anticipated conditions during these extreme space weather event will enable operators and users of affected technologies to develop plans for mitigating space weather risks and improve preparedness. The ionosphere is one of the most important regions of space because so many applications either depend on ionospheric space weather for their operation (HF communication, over-the-horizon radars), or can be deleteriously affected by ionospheric conditions (e.g. GNSS navigation and timing, UHF satellite communications, synthetic aperture radar, HF communications). Since the processes that influence the ionosphere vary over time scales from seconds to years, it continues to be a challenge to adequately predict its behavior in many circumstances. Estimates with large uncertainties, in excess of 100%, may result in operators of impacted technologies over or under preparing for such events. The goal of the next phase of the benchmarking activity is to reduce these uncertainties. In this presentation, we will focus on the sources of uncertainty in the ionospheric response to extreme geomagnetic storms. We will then discuss various research efforts required to better understand the underlying processes of ionospheric variability and how the uncertainties in ionospheric response to extreme space weather could be reduced and the estimates improved.

Environmental control and life support testing at the Marshall Space Flight Center

Science.gov (United States)

Schunk, Richard G.; Humphries, William R.

1987-01-01

The Space Station Environmental Control and Life Support System (ECLSS) test program at the Marshall Space Flight Center (MSFC) is addressed. The immediate goals and current activities of the test program are discussed. Also described are the Core Module Integration Facility (CMIF) and the initial ECLSS test configuration. Future plans for the ECLSS test program and the CMIF are summarized.

Environmental filtering structures tree functional traits combination and lineages across space in tropical tree assemblages.

Science.gov (United States)

Asefa, Mengesha; Cao, Min; Zhang, Guocheng; Ci, Xiuqin; Li, Jie; Yang, Jie

2017-03-09

Environmental filtering consistently shapes the functional and phylogenetic structure of species across space within diverse forests. However, poor descriptions of community functional and lineage distributions across space hamper the accurate understanding of coexistence mechanisms. We combined environmental variables and geographic space to explore how traits and lineages are filtered by environmental factors using extended RLQ and fourth-corner analyses across different spatial scales. The dispersion patterns of traits and lineages were also examined in a 20-ha tropical rainforest dynamics plot in southwest China. We found that environmental filtering was detected across all spatial scales except the largest scale (100 × 100 m). Generally, the associations between functional traits and environmental variables were more or less consistent across spatial scales. Species with high resource acquisition-related traits were associated with the resource-rich part of the plot across the different spatial scales, whereas resource-conserving functional traits were distributed in limited-resource environments. Furthermore, we found phylogenetic and functional clustering at all spatial scales. Similar functional strategies were also detected among distantly related species, suggesting that phylogenetic distance is not necessarily a proxy for functional distance. In summary, environmental filtering considerably structured the trait and lineage assemblages in this species-rich tropical rainforest.

Nuclear disassembly time scales using space time correlations

Energy Technology Data Exchange (ETDEWEB)

Durand, D.; Colin, J.; Lecolley, J.F.; Meslin, C.; Aboufirassi, M.; Bougault, R.; Brou, R. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Bilwes, B.; Cosmo, F. [Strasbourg-1 Univ., 67 (France); Galin, J. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); and others

1996-09-01

The lifetime, {tau}, with respect to multifragmentation of highly excited nuclei is deduced from the analysis of strongly damped Pb+Au collisions at 29 MeV/u. The method is based on the study of space-time correlations induced by `proximity` effects between fragments emitted by the two primary products of the reaction and gives the time between the re-separation of the two primary products and the subsequent multifragment decay of one partner. (author). 2 refs.

Space-Time Fractional Diffusion-Advection Equation with Caputo Derivative

Directory of Open Access Journals (Sweden)

José Francisco Gómez Aguilar

2014-01-01

Full Text Available An alternative construction for the space-time fractional diffusion-advection equation for the sedimentation phenomena is presented. The order of the derivative is considered as 0<β, γ≤1 for the space and time domain, respectively. The fractional derivative of Caputo type is considered. In the spatial case we obtain the fractional solution for the underdamped, undamped, and overdamped case. In the temporal case we show that the concentration has amplitude which exhibits an algebraic decay at asymptotically large times and also shows numerical simulations where both derivatives are taken in simultaneous form. In order that the equation preserves the physical units of the system two auxiliary parameters σx and σt are introduced characterizing the existence of fractional space and time components, respectively. A physical relation between these parameters is reported and the solutions in space-time are given in terms of the Mittag-Leffler function depending on the parameters β and γ. The generalization of the fractional diffusion-advection equation in space-time exhibits anomalous behavior.

Environmental assessment of alternative pasteurization technologies for fluid milk production using process simulation

Science.gov (United States)

Fluid milk processing (FMP) has significant environmental impact because of its high energy use. High temperature short time (HTST) pasteurization is the third most energy intensive operation comprising about 16% of total energy use, after clean-in-place operations and packaging. Nonthermal processe...

Quantum dynamical time evolutions as stochastic flows on phase space

International Nuclear Information System (INIS)

Combe, P.; Rodriguez, R.; Guerra, F.; Sirigue, M.; Sirigue-Collin, M.

1984-01-01

We are mainly interested in describing the time development of the Wigner functions by means of stochastic processes. In the second section we recall the main properties of the Wigner functions as well as those of their Fourier transform. In the next one we derive the evolution equation of these functions for a class of Hamiltonians and we give a probabilistic expression for the solution of these equations by means of a stochastic flow in phase space which reminds of the classical flows. In the last section we remark that the previously defined flow can be extended to the bounded continuous functions on phase space and that this flow conserves the cone generated by the Wigner functions. (orig./HSI)

Deep-inelastic final states in a space-time description of shower development and hadronization

International Nuclear Information System (INIS)

Ellis, J.

1996-06-01

We extend a quantum kinetic approach to the description of hadronic showers in space, time and momentum space to deep-inelastic ep collisions, with particular reference to experiments at HERA. We follow the history of hard scattering events back to the initial hadronic state and forward to the formation of colour-singlet pre-hadronic clusters and their decays into hadrons. The time evolution of the space-like initial-state shower and the time-like secondary partons are treated similarly, and cluster formation is treated using a spatial criterion motivated by confinement and a non-perturbative model for hadronization. We calculate the time evolution of particle distributions in rapidity, transverse and longitudinal space. We also compare the transverse hadronic energy flow and the distribution of observed hadronic masses with experimental data from HERA, finding encouraging results, and discuss the background to large-rapidity-gap events. The techniques developed in this paper may be applied in the future to more complicated processes such as eA, pp, pA and AA collisions. (orig.)

Vector mass in curved space-times

International Nuclear Information System (INIS)

Maia, M.D.

The use of the Poincare-symmetry appears to be incompatible with the presence of the gravitational field. The consequent problem of the definition of the mass operator is analysed and an alternative definition based on constant curvature tangent spaces is proposed. In the case where the space-time has no killing vector fields, four independent mass operators can be defined at each point. (Author) [pt

Design space development for the extraction process of Danhong injection using a Monte Carlo simulation method.

Directory of Open Access Journals (Sweden)

Xingchu Gong

Full Text Available A design space approach was applied to optimize the extraction process of Danhong injection. Dry matter yield and the yields of five active ingredients were selected as process critical quality attributes (CQAs. Extraction number, extraction time, and the mass ratio of water and material (W/M ratio were selected as critical process parameters (CPPs. Quadratic models between CPPs and CQAs were developed with determination coefficients higher than 0.94. Active ingredient yields and dry matter yield increased as the extraction number increased. Monte-Carlo simulation with models established using a stepwise regression method was applied to calculate the probability-based design space. Step length showed little effect on the calculation results. Higher simulation number led to results with lower dispersion. Data generated in a Monte Carlo simulation following a normal distribution led to a design space with a smaller size. An optimized calculation condition was obtained with 10,000 simulation times, 0.01 calculation step length, a significance level value of 0.35 for adding or removing terms in a stepwise regression, and a normal distribution for data generation. The design space with a probability higher than 0.95 to attain the CQA criteria was calculated and verified successfully. Normal operating ranges of 8.2-10 g/g of W/M ratio, 1.25-1.63 h of extraction time, and two extractions were recommended. The optimized calculation conditions can conveniently be used in design space development for other pharmaceutical processes.

The joint space-time statistics of macroweather precipitation, space-time statistical factorization and macroweather models

International Nuclear Information System (INIS)

Lovejoy, S.; Lima, M. I. P. de

2015-01-01

Over the range of time scales from about 10 days to 30–100 years, in addition to the familiar weather and climate regimes, there is an intermediate “macroweather” regime characterized by negative temporal fluctuation exponents: implying that fluctuations tend to cancel each other out so that averages tend to converge. We show theoretically and numerically that macroweather precipitation can be modeled by a stochastic weather-climate model (the Climate Extended Fractionally Integrated Flux, model, CEFIF) first proposed for macroweather temperatures and we show numerically that a four parameter space-time CEFIF model can approximately reproduce eight or so empirical space-time exponents. In spite of this success, CEFIF is theoretically and numerically difficult to manage. We therefore propose a simplified stochastic model in which the temporal behavior is modeled as a fractional Gaussian noise but the spatial behaviour as a multifractal (climate) cascade: a spatial extension of the recently introduced ScaLIng Macroweather Model, SLIMM. Both the CEFIF and this spatial SLIMM model have a property often implicitly assumed by climatologists that climate statistics can be “homogenized” by normalizing them with the standard deviation of the anomalies. Physically, it means that the spatial macroweather variability corresponds to different climate zones that multiplicatively modulate the local, temporal statistics. This simplified macroweather model provides a framework for macroweather forecasting that exploits the system's long range memory and spatial correlations; for it, the forecasting problem has been solved. We test this factorization property and the model with the help of three centennial, global scale precipitation products that we analyze jointly in space and in time

Solid waste treatment processes for space station

Science.gov (United States)

Marrero, T. R.

1983-01-01

The purpose of this study was to evaluate the state-of-the-art of solid waste(s) treatment processes applicable to a Space Station. From the review of available information a source term model for solid wastes was determined. An overall system is proposed to treat solid wastes under constraints of zero-gravity and zero-leakage. This study contains discussion of more promising potential treatment processes, including supercritical water oxidation, wet air (oxygen) oxidation, and chemical oxidation. A low pressure, batch-type treament process is recommended. Processes needed for pretreatment and post-treatment are hardware already developed for space operations. The overall solid waste management system should minimize transfer of wastes from their collection point to treatment vessel.

The NREL Biochemical and Thermochemical Ethanol Conversion Processes: Financial and Environmental Analysis Comparison

Directory of Open Access Journals (Sweden)

Jesse Sky Daystar

2015-07-01

Full Text Available The financial and environmental performance of the National Renewable Energy Lab’s (NREL thermochemical and biochemical biofuel conversion processes are examined herein with pine, eucalyptus, unmanaged hardwood, switchgrass, and sweet sorghum. The environmental impacts of the process scenarios were determined by quantifying greenhouse gas (GHG emissions and TRACI impacts. Integrated financial and environmental performance metrics were introduced and used to examine the biofuel production scenarios. The thermochemical and biochemical conversion processes produced the highest financial performance and lowest environmental impacts when paired with pine and sweet sorghum, respectively. The high ash content of switchgrass and high lignin content of loblolly pine lowered conversion yields, resulting in the highest environmental impacts and lowest financial performance for the thermochemical and biochemical conversion processes, respectively. Biofuel produced using the thermochemical conversion process resulted in lower TRACI single score impacts and somewhat lower GHG emissions per megajoule (MJ of fuel than using the biochemical conversion pathway. The cost of carbon mitigation resulting from biofuel production and corresponding government subsidies was determined to be higher than the expected market carbon price. In some scenarios, the cost of carbon mitigation was several times higher than the market carbon price, indicating that there may be other more cost-effective methods of reducing carbon emissions.

Is the shell-focusing singularity of Szekeres space-time visible?

International Nuclear Information System (INIS)

Nolan, Brien C; Debnath, Ujjal

2007-01-01

The visibility of the shell-focusing singularity in Szekeres space-time--which represents quasispherical dust collapse--has been studied on numerous occasions in the context of the cosmic censorship conjecture. The various results derived have assumed that there exist radial null geodesics in the space-time. We show that such geodesics do not exist in general, and so previous results on the visibility of the singularity are not generally valid. More precisely, we show that the existence of a radial geodesic in Szekeres space-time implies that the space-time is axially symmetric, with the geodesic along the polar direction (i.e. along the axis of symmetry). If there is a second nonparallel radial geodesic, then the space-time is spherically symmetric, and so is a Lemaitre-Tolman-Bondi space-time. For the case of the polar geodesic in an axially symmetric Szekeres space-time, we give conditions on the free functions (i.e. initial data) of the space-time which lead to visibility of the singularity along this direction. Likewise, we give a sufficient condition for censorship of the singularity. We point out the complications involved in addressing the question of visibility of the singularity both for nonradial null geodesics in the axially symmetric case and in the general (nonaxially symmetric) case, and suggest a possible approach

Visualizing Human Migration Trhough Space and Time

Science.gov (United States)

Zambotti, G.; Guan, W.; Gest, J.

2015-07-01

Human migration has been an important activity in human societies since antiquity. Since 1890, approximately three percent of the world's population has lived outside of their country of origin. As globalization intensifies in the modern era, human migration persists even as governments seek to more stringently regulate flows. Understanding this phenomenon, its causes, processes and impacts often starts from measuring and visualizing its spatiotemporal patterns. This study builds a generic online platform for users to interactively visualize human migration through space and time. This entails quickly ingesting human migration data in plain text or tabular format; matching the records with pre-established geographic features such as administrative polygons; symbolizing the migration flow by circular arcs of varying color and weight based on the flow attributes; connecting the centroids of the origin and destination polygons; and allowing the user to select either an origin or a destination feature to display all flows in or out of that feature through time. The method was first developed using ArcGIS Server for world-wide cross-country migration, and later applied to visualizing domestic migration patterns within China between provinces, and between states in the United States, all through multiple years. The technical challenges of this study include simplifying the shapes of features to enhance user interaction, rendering performance and application scalability; enabling the temporal renderers to provide time-based rendering of features and the flow among them; and developing a responsive web design (RWD) application to provide an optimal viewing experience. The platform is available online for the public to use, and the methodology is easily adoptable to visualizing any flow, not only human migration but also the flow of goods, capital, disease, ideology, etc., between multiple origins and destinations across space and time.

Space, time and causality

International Nuclear Information System (INIS)

Lucas, J.R.

1984-01-01

Originating from lectures given to first year undergraduates reading physics and philosophy or mathematics and philosophy, formal logic is applied to issues and the elucidation of problems in space, time and causality. No special knowledge of relativity theory or quantum mechanics is needed. The text is interspersed with exercises and each chapter is preceded by a suggested 'preliminary reading' and followed by 'further reading' references. (U.K.)

International Space Station Environmental Control and Life Support System Status: 2011-2012

Science.gov (United States)

Williams, David E.; Dake, Jason R.; Gentry, Gregory J.

2011-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the U.S. ECLS system activities over the past year and the impacts of the international partners activities on them, covering the period of time between March 2011 and February 2012. The ISS continued permanent crew operations including the continuation of six crew members being on ISS. Work continues on the commercial cargo resupply vehicles, and work to try and extend ISS service life from 2015 to no later than 2028. 1

Quantum theory of spinor field in four-dimensional Riemannian space-time

International Nuclear Information System (INIS)

Shavokhina, N.S.

1996-01-01

The review deals with the spinor field in the four-dimensional Riemannian space-time. The field beys the Dirac-Fock-Ivanenko equation. Principles of quantization of the spinor field in the Riemannian space-time are formulated which in a particular case of the plane space-time are equivalent to the canonical rules of quantization. The formulated principles are exemplified by the De Sitter space-time. The study of quantum field theory in the De Sitter space-time is interesting because it itself leads to a method of an invariant well for plane space-time. However, the study of the quantum spinor field theory in an arbitrary Riemannian space-time allows one to take into account the influence of the external gravitational field on the quantized spinor field. 60 refs

Electromagnetic-field equations in the six-dimensional space-time R6

International Nuclear Information System (INIS)

Teli, M.T.; Palaskar, D.

1984-01-01

Maxwell's equations (without monopoles) for electromagnetic fields are obtained in six-dimensional space-time. The equations possess structural symmetry in space and time, field and source densities. Space-time-symmetric conservation laws and field solutions are obtained. The results are successfully correlated with their four-dimensional space-time counterparts

Assessment of MSFCs Process for the Development and Activation of Space Act Agreement

Science.gov (United States)

Daugherty, Rachel

2014-01-01

Space Act Agreements (SAAs) are contractual agreements that NASA utilizes to form partnerships with researchers, industry, and academia to stimulate cutting-edge innovation within the science and technology communities. center dot This study assessed the current SAA development and activation process at Marshall Space Flight Center (MSFC) to determine if improvements could be implemented to increase productivity, decrease time to activation, and improve the quality of deliverables.

Real-Time and Post-Processed Orbit Determination and Positioning

Science.gov (United States)

Bar-Sever, Yoaz E. (Inventor); Bertiger, William I. (Inventor); Dorsey, Angela R. (Inventor); Harvey, Nathaniel E. (Inventor); Lu, Wenwen (Inventor); Miller, Kevin J. (Inventor); Miller, Mark A. (Inventor); Romans, Larry J. (Inventor); Sibthorpe, Anthony J. (Inventor); Weiss, Jan P. (Inventor);

Point-like Particles in Fuzzy Space-time

OpenAIRE

Francis, Charles

1999-01-01

This paper is withdrawn as I am no longer using the term "fuzzy space- time" to describe the uncertainty in co-ordinate systems implicit in quantum logic. Nor am I using the interpretation that quantum logic can be regarded as a special case of fuzzy logic. This is because there are sufficient differences between quantum logic and fuzzy logic that the explanation is confusing. I give an interpretation of quantum logic in "A Theory of Quantum Space-time"

Extrusion: An environmentally friendly process for PEMFC membrane elaboration

Energy Technology Data Exchange (ETDEWEB)

Sanchez, J.-Y.; Iojoiu, C.; Marechal, M. [LEPMI, UMR 5631 CNRS-INPG-UJF, ENSEEG, BP 75, F-38402, Saint Martin d' Heres (France); Chabert, F.; El Kissi, N. [Rheologie, UMR 5520 CNRS-INPG-UJF, ENSHMG, BP 53, F-38041, Grenoble (France); Salomon, J.; Mercier, R. [LMOPS UMR CNRS 5041, BP 24, F-69390 Vernaison (France); Piffard, Y. [CNRS Universite de Nantes, Institut des Materiaux Jean Rouxel, UMR 6502, BP 32229, F-44322, Nantes Cedex 3 (France); Galiano, H. [CEA, Le Ripault Research Center, BP 16, F-37260, Monts (France)

2007-12-31

The paper deals with the use of extrusion to process PEMFC filled and unfilled membranes. Several routes including the sulfonation of filled and unfilled extruded membranes and the extrusion of filled and unfilled ionomers are reported. Thanks to the use of selected water-soluble aid process plasticizers, acid and alkaline forms of sulfonated polyethersulfone were, for the first time, successfully extruded. The extrusion process did not lead to any degradation of the ionomer performances. Decreasing the membrane cost while using environmentally friendly elaboration conditions, it should be helpful to an industrial production. In addition, avoiding filler sedimentation it should allow homogeneous composite membranes to be obtained. (author)

On-board Payload Data Processing from Earth to Space Segment

Science.gov (United States)

Tragni, M.; Abbattista, C.; Amoruso, L.; Cinquepalmi, L.; Bgongiari, F.; Errico, W.

2013-09-01

environment with encapsulated low-level drivers, HW support and testing environment). Furthermore Space PDP presents an advanced processing system to be fully adopted both as on-board module for EO spacecrafts and extra-planetary exploration rovers. The main innovative aspects are: • HW and SW modularity - scalability for the Payload Data Processing and AOC S/S • Complex processing capabilities fully available onboard (on spacecrafts or rovers) • Reduced effort in mission SW design, implementation, verification and validation tasks • HW abstraction level comparable to present multitasking Unix-like systems allowing SW and algorithms re-use (also from available GS applications). The development approach addressed by SpacePDP is based both on the re-use and resources sharing with flexible elements adjustable to different missions and to different tasks within the same mission (e.g. shared between AOCS and data management S/S) and on a strong specialization in the system elements that are designed to satisfy specific mission needs and specific technological innovations. The innovative processing system is proven in many possible scenarios of use from standard compression task up to the most complex one as the image classification directly on-board. The first one is just useful for standard benchmark trade-off analysis of HW and SW capabilities respect to the other common processing modules. The classification is the ambitious objective of that system to process directly on board the data from sensor (by down-sampling or in no-full resolution acquisition modality if necessary) to detect at flight time any features on ground or observed phenomenas. For Earth application it could be the cloud coverage (to avoid the acquisition and discard the data), burning areas or vessels detection and similar. On Planetary o Universe exploration mission it could be the path recognition for a rover, or high power energy events in outbound galaxies. Sometimes it could be need to review the

Cost-time management for environmental restoration activities at the Department of Energy`s Idaho National Engineering Laboratory, Idaho Chemical Processing Plant

Energy Technology Data Exchange (ETDEWEB)

Fourr, B.R.; Owen, A.H.; Williamson, D.J. [Westinghouse Idaho Nuclear Co., Inc., Idaho Falls, ID (United States); Nash, C.L. [USDOE Idaho Field Office, Idaho Falls, ID (United States)

1992-05-22

Cost-time management methods have been developed by Westinghouse to examine business applications from a cost-time perspective. The initial application of cost-time management within Westinghouse was targeted at reducing cycle time in the manufacturing sector. As a result of the tremendous success of reduced cycle time in manufacturing, Westinghouse initiated application of the management technique to Environmental Restoration activities at its Government Owned Contractor Operated facilities. The Westinghouse initiative was proposed in support of the Department of Energy`s goals for cost effective Environmental Restoration activities. This paper describes the application of the cost-time method to Environmental Restoration work currently being performed at the Idaho National Engineering Laboratory (INEL) for the Department of Energy (DOE) by Westinghouse Idaho Nuclear Company (WINCO).

A 2D multi-term time and space fractional Bloch-Torrey model based on bilinear rectangular finite elements

Science.gov (United States)

Qin, Shanlin; Liu, Fawang; Turner, Ian W.

2018-03-01

The consideration of diffusion processes in magnetic resonance imaging (MRI) signal attenuation is classically described by the Bloch-Torrey equation. However, many recent works highlight the distinct deviation in MRI signal decay due to anomalous diffusion, which motivates the fractional order generalization of the Bloch-Torrey equation. In this work, we study the two-dimensional multi-term time and space fractional diffusion equation generalized from the time and space fractional Bloch-Torrey equation. By using the Galerkin finite element method with a structured mesh consisting of rectangular elements to discretize in space and the L1 approximation of the Caputo fractional derivative in time, a fully discrete numerical scheme is derived. A rigorous analysis of stability and error estimation is provided. Numerical experiments in the square and L-shaped domains are performed to give an insight into the efficiency and reliability of our method. Then the scheme is applied to solve the multi-term time and space fractional Bloch-Torrey equation, which shows that the extra time derivative terms impact the relaxation process.

NPOESS Interface Data Processing Segment (IDPS) Hardware

Science.gov (United States)

Sullivan, W. J.; Grant, K. D.; Bergeron, C.

2008-12-01

The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The NPOESS design allows centralized mission management and delivers high quality environmental products to military, civil and scientific users. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. IDPS processes NPOESS satellite data to provide environmental data products to NOAA and DoD processing centers operated by the United States government. IDPS will process environmental data products beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. Within the overall NPOESS processing environment, the IDPS must process a data volume several orders of magnitude the size of current systems -- in one-quarter of the time. Further, it must support the calibration, validation, and data quality improvement initiatives of the NPOESS program to ensure the production of atmospheric and environmental products that meet strict requirements for accuracy and precision. This poster will illustrate and describe the IDPS HW architecture that is necessary to meet these challenging design requirements. In addition, it will illustrate the expandability features of the architecture in support of future data processing and data distribution needs.

LEAP: local environmental action plan. Municipality of Lipkovo

International Nuclear Information System (INIS)

2004-01-01

This document comprises all geo-environmental problems with adverse on the quality of the overall environment. Based on this, the document contains many scientific and expert statements and facts supported by data, diagrams maps, etc. At the same time, taking into consideration the problems appearing on the territory of Lipkovo Municipality, the environmental problems are by their priority presented as issues of first, second and third degree, requiring most urgent settlement through the leap document for the Municipality of Lipkovo. This is followed by the presentation of priorities and the strategy for elimination of degradation processes and establishment of environmental balance in the space. According to the current data, it seems that this Municipality is faced with numerous environmental problems, beginning with air pollution, water contamination, solid waste disposal, the landfill of the abandoned mine Lojane and the site around the Railroad Station at Tabanovci, supply of drinking water, destruction of forests, expansion of rural settlements over cultivable lands, the issue of space urbanization, unemployment, etc

Real Time Space Weather Support for Chandra X-Ray Observatory Operations

Science.gov (United States)

O'Dell, Stephen L.; Minow, Joseph I.; Miller, J. Scott; Wolk, Scott J.; Aldcroft, Thomas L.; Spitzbart, Bradley D.; Swartz. Douglas A.

2012-01-01

NASA launched the Chandra X-ray Observatory in July 1999. Soon after first light in August 1999, however, degradation in the energy resolution and charge transfer efficiency of the Advanced CCD Imaging Spectrometer (ACIS) x-ray detectors was observed. The source of the degradation was quickly identified as radiation damage in the charge-transfer channel of the front-illuminated CCDs, by weakly penetrating ( soft , 100 500 keV) protons as Chandra passed through the Earth s radiation belts and ring currents. As soft protons were not considered a risk to spacecraft health before launch, the only on-board radiation monitoring system is the Electron, Proton, and Helium Instrument (EPHIN) which was included on Chandra with the primary purpose of monitoring energetic solar particle events. Further damage to the ACIS detector has been successfully mitigated through a combination of careful mission planning, autonomous on-board radiation protection, and manual intervention based upon real-time monitoring of the soft-proton environment. The AE-8 and AP-8 trapped radiation models and Chandra Radiation Models are used to schedule science operations in regions of low proton flux. EPHIN has been used as the primary autonomous in-situ radiation trigger; but, it is not sensitive to the soft protons that damage the front-illuminated CCDs. Monitoring of near-real-time space weather data sources provides critical information on the proton environment outside the Earth s magnetosphere due to solar proton events and other phenomena. The operations team uses data from the Geostationary Operational Environmental Satellites (GOES) to provide near-real-time monitoring of the proton environment; however, these data do not give a representative measure of the soft-proton (real-time data provided by NOAA s Space Weather Prediction Center. This presentation describes the radiation mitigation strategies to minimize the proton damage in the ACIS CCD detectors and the importance of real-time data

Alternatives and implication in process of environmental impact assessment

Directory of Open Access Journals (Sweden)

Tauš Peter

2001-12-01

Full Text Available EIA is an interactive, rule-based expert system for the environmental impact assessment. It is designed for a screening level assessment of development projects at a pre-feasibility stage. Typical problems for the evaluation include: resettlement; watershed degradation; encroachment upon precious ecosystems; encroachment on historical/cultural values; watershed erosion; reservoir siltation; impairment of navigation; changes in groundwater hydrology, waterlogging; seepage and evaporation losses; migration of valuable fish species; inundation of mineral resources/forests; other inundation losses and adverse effects. It is important to prevent environmental pollution when carrying out large-scale development projects, such as artificial change of landscapes and building of certain structures that may cause a tremendous impact on the environment. In accordance with Cities Environmental Impact Assessment Departments it is necessary to provide project organisers with a necessary advice and instructions concerning the environmental impact assessment a survey to predict and evaluate environmental impact to be conducted by project organisers. Prior to offering the advice and instructions, cities need to hear the opinions of residents of the areas concerned, mayors of related municipalities and other opinion leaders, including specialists, to reflect their views in the environmental preservation. The first aspect in any quality assessment is to determine the representativeness of data both in terms of physical siting and data collected. It must be recognised the environment is a dynamic fluid; quality therefore varies over space and time. There will be locations in any community that experience poorer quality than recorded at a monitoring station. Likewise other sites will have a better quality. Most communities have only a single monitoring site. Therefore, the air quality monitors are sited to provide a representative estimate of the community exposure

Space-Time Chip Equalization for Maximum Diversity Space-Time Block Coded DS-CDMA Downlink Transmission

NARCIS (Netherlands)

Leus, G.; Petré, F.; Moonen, M.

2004-01-01

In the downlink of DS-CDMA, frequency-selectivity destroys the orthogonality of the user signals and introduces multiuser interference (MUI). Space-time chip equalization is an efficient tool to restore the orthogonality of the user signals and suppress the MUI. Furthermore, multiple-input

Development of a prototype real-time automated filter for operational deep space navigation

Science.gov (United States)

Masters, W. C.; Pollmeier, V. M.

1994-01-01

Operational deep space navigation has been in the past, and is currently, performed using systems whose architecture requires constant human supervision and intervention. A prototype for a system which allows relatively automated processing of radio metric data received in near real-time from NASA's Deep Space Network (DSN) without any redesign of the existing operational data flow has been developed. This system can allow for more rapid response as well as much reduced staffing to support mission navigation operations.

Environmental Sound Recognition Using Time-Frequency Intersection Patterns

Directory of Open Access Journals (Sweden)

Xuan Guo

2012-01-01

Full Text Available Environmental sound recognition is an important function of robots and intelligent computer systems. In this research, we use a multistage perceptron neural network system for environmental sound recognition. The input data is a combination of time-variance pattern of instantaneous powers and frequency-variance pattern with instantaneous spectrum at the power peak, referred to as a time-frequency intersection pattern. Spectra of many environmental sounds change more slowly than those of speech or voice, so the intersectional time-frequency pattern will preserve the major features of environmental sounds but with drastically reduced data requirements. Two experiments were conducted using an original database and an open database created by the RWCP project. The recognition rate for 20 kinds of environmental sounds was 92%. The recognition rate of the new method was about 12% higher than methods using only an instantaneous spectrum. The results are also comparable with HMM-based methods, although those methods need to treat the time variance of an input vector series with more complicated computations.

Mach's principle and space-time structure

International Nuclear Information System (INIS)

Raine, D.J.

1981-01-01

Mach's principle, that inertial forces should be generated by the motion of a body relative to the bulk of matter in the universe, is shown to be related to the structure imposed on space-time by dynamical theories. General relativity theory and Mach's principle are both shown to be well supported by observations. Since Mach's principle is not contained in general relativity this leads to a discussion of attempts to derive Machian theories. The most promising of these appears to be a selection rule for solutions of the general relativistic field equations, in which the space-time metric structure is generated by the matter content of the universe only in a well-defined way. (author)

Ghost neutrinos as test fields in curved space-time

International Nuclear Information System (INIS)

Audretsch, J.

1976-01-01

Without restricting to empty space-times, it is shown that ghost neutrinos (their energy-momentum tensor vanishes) can only be found in algebraically special space-times with a neutrino flux vector parallel to one of the principal null vectors of the conformal tensor. The optical properties are studied. There are no ghost neutrinos in the Kerr-Newman and in spherically symmetric space-times. The example of a non-vacuum gravitational pp-wave accompanied by a ghost neutrino pp-wave is discussed. (Auth.)

Time compression diseconomies in environmental management: the effect of assimilation on environmental performance.

Science.gov (United States)

Lannelongue, Gustavo; Gonzalez-Benito, Javier; Gonzalez-Benito, Oscar; Gonzalez-Zapatero, Carmen

2015-01-01

This research addresses the relationship between an organisation's assimilation of its environmental management system (EMS), the experience it gains through it, and its environmental performance. Assimilation here refers to the degree to which the requirements of the management standard are integrated within a plant's daily operations. Basing ourselves on the heterogeneity of organisations, we argue that assimilation and experience will inform environmental performance. Furthermore, we posit that the relationship between assimilation and environmental performance depends on experience. The attempt to obtain greater assimilation in a shorter time leads an organisation to record a poorer environmental outcome, which we shall refer to as time compression diseconomies in environmental management. We provide empirical evidence based on 154 plants pertaining to firms in Spain subject to the European Union's CO2 Emissions Trading System. Copyright © 2014 Elsevier Ltd. All rights reserved.

Environmental control costs for oil shale processes

Energy Technology Data Exchange (ETDEWEB)

None

1979-10-01

The studies reported herein are intended to provide more certainty regarding estimates of the costs of controlling environmental residuals from oil shale technologies being readied for commercial application. The need for this study was evident from earlier work conducted by the Office of Environment for the Department of Energy Oil Shale Commercialization Planning, Environmental Readiness Assessment in mid-1978. At that time there was little reliable information on the costs for controlling residuals and for safe handling of wastes from oil shale processes. The uncertainties in estimating costs of complying with yet-to-be-defined environmental standards and regulations for oil shale facilities are a critical element that will affect the decision on proceeding with shale oil production. Until the regulatory requirements are fully clarified and processes and controls are investigated and tested in units of larger size, it will not be possible to provide definitive answers to the cost question. Thus, the objective of this work was to establish ranges of possible control costs per barrel of shale oil produced, reflecting various regulatory, technical, and financing assumptions. Two separate reports make up the bulk of this document. One report, prepared by the Denver Research Institute, is a relatively rigorous engineering treatment of the subject, based on regulatory assumptions and technical judgements as to best available control technologies and practices. The other report examines the incremental cost effect of more conservative technical and financing alternatives. An overview section is included that synthesizes the products of the separate studies and addresses two variations to the assumptions.

Estimation and Application of Ecological Memory Functions in Time and Space

Science.gov (United States)

Itter, M.; Finley, A. O.; Dawson, A.

2017-12-01

A common goal in quantitative ecology is the estimation or prediction of ecological processes as a function of explanatory variables (or covariates). Frequently, the ecological process of interest and associated covariates vary in time, space, or both. Theory indicates many ecological processes exhibit memory to local, past conditions. Despite such theoretical understanding, few methods exist to integrate observations from the recent past or within a local neighborhood as drivers of these processes. We build upon recent methodological advances in ecology and spatial statistics to develop a Bayesian hierarchical framework to estimate so-called ecological memory functions; that is, weight-generating functions that specify the relative importance of local, past covariate observations to ecological processes. Memory functions are estimated using a set of basis functions in time and/or space, allowing for flexible ecological memory based on a reduced set of parameters. Ecological memory functions are entirely data driven under the Bayesian hierarchical framework—no a priori assumptions are made regarding functional forms. Memory function uncertainty follows directly from posterior distributions for model parameters allowing for tractable propagation of error to predictions of ecological processes. We apply the model framework to simulated spatio-temporal datasets generated using memory functions of varying complexity. The framework is also applied to estimate the ecological memory of annual boreal forest growth to local, past water availability. Consistent with ecological understanding of boreal forest growth dynamics, memory to past water availability peaks in the year previous to growth and slowly decays to zero in five to eight years. The Bayesian hierarchical framework has applicability to a broad range of ecosystems and processes allowing for increased understanding of ecosystem responses to local and past conditions and improved prediction of ecological

An evaluation of space time cube representation of spatiotemporal patterns.

Science.gov (United States)

Kristensson, Per Ola; Dahlbäck, Nils; Anundi, Daniel; Björnstad, Marius; Gillberg, Hanna; Haraldsson, Jonas; Mårtensson, Ingrid; Nordvall, Mathias; Ståhl, Josefine

2009-01-01

Space time cube representation is an information visualization technique where spatiotemporal data points are mapped into a cube. Information visualization researchers have previously argued that space time cube representation is beneficial in revealing complex spatiotemporal patterns in a data set to users. The argument is based on the fact that both time and spatial information are displayed simultaneously to users, an effect difficult to achieve in other representations. However, to our knowledge the actual usefulness of space time cube representation in conveying complex spatiotemporal patterns to users has not been empirically validated. To fill this gap, we report on a between-subjects experiment comparing novice users' error rates and response times when answering a set of questions using either space time cube or a baseline 2D representation. For some simple questions, the error rates were lower when using the baseline representation. For complex questions where the participants needed an overall understanding of the spatiotemporal structure of the data set, the space time cube representation resulted in on average twice as fast response times with no difference in error rates compared to the baseline. These results provide an empirical foundation for the hypothesis that space time cube representation benefits users analyzing complex spatiotemporal patterns.

GOES-R Space Weather Data: Achieving User Ready Products

Science.gov (United States)

Rowland, W. F.; Tilton, M.; Redmon, R. J.; Goodman, S. J.; Comerford, M.

2017-12-01

Forecasters and the science community will rely on improved Space Weather products from the next generation of Geostationary Operational Environmental Satellite (GOES-R Series) for decades to come. Many issues must be successfully addressed in order to produce useful products. The instruments themselves and their basic scientific measurements (Level 1b data, i.e. L1b) must be calibrated and validated. Algorithms must be created to transform L1b into the specific environmental parameters that are of interest to forecasters and the community (Level 2+, i.e. L2+). In the case of Space Weather data, because the L2+ products are not generated within the core GOES-R Ground Segment, a separate system had to be developed in order to implement the L2+ products. Finally, the products must be made available to real time and retrospective users, as well as preserved for future generations. We give an overview of the path to production of the GOES-R Space Weather products, and the role of the National Centers for Environmental Information (NCEI) in this process.

Space- and time-resolved measurements of ion energy distributions by neutral beam injection in TORTUR II

International Nuclear Information System (INIS)

Brocken, H.J.B.M.

1981-10-01

A method is described for the space- and time-resolved analysis of ion energy distributions in a plasma. A well-collimated neutral hydrogen beam is used to enhance the charge-exchange processes. The method is used in the TORTUR II tokamak to study the space and time evolution of the ion temperature profile of the plasma. The analytical background and the technique are described in detail. Examples of measurements on TORTUR II are presented

Optimal Time-Space Trade-Offs for Non-Comparison-Based Sorting

DEFF Research Database (Denmark)

Pagh, Rasmus; Pagter, Jacob Illeborg

2002-01-01

We study the problem of sorting n integers of w bits on a unit-cost RAM with word size w, and in particular consider the time-space trade-off (product of time and space in bits) for this problem. For comparison-based algorithms, the time-space complexity is known to be Θ(n2). A result of Beame...... shows that the lower bound also holds for non-comparison-based algorithms, but no algorithm has met this for time below the comparison-based Ω(nlgn) lower bound.We show that if sorting within some time bound &Ttilde; is possible, then time T = O(&Ttilde; + nlg* n) can be achieved with high probability...... using space S = O(n2/T + w), which is optimal. Given a deterministic priority queue using amortized time t(n) per operation and space nO(1), we provide a deterministic algorithm sorting in time T = O(n(t(n) + lg* n)) with S = O(n2/T + w). Both results require that w ≤ n1-Ω(1). Using existing priority...

Charged fluid distribution in higher dimensional spheroidal space-time

Indian Academy of Sciences (India)

A general solution of Einstein field equations corresponding to a charged fluid distribution on the background of higher dimensional spheroidal space-time is obtained. The solution generates several known solutions for superdense star having spheroidal space-time geometry.

Constant scalar curvature hypersurfaces in extended Schwarzschild space-time

International Nuclear Information System (INIS)

Pareja, M. J.; Frauendiener, J.

2006-01-01

We present a class of spherically symmetric hypersurfaces in the Kruskal extension of the Schwarzschild space-time. The hypersurfaces have constant negative scalar curvature, so they are hyperboloidal in the regions of space-time which are asymptotically flat

Tracking and visualization of space-time activities for a micro-scale flu transmission study.

Science.gov (United States)

Qi, Feng; Du, Fei

2013-02-07

Infectious diseases pose increasing threats to public health with increasing population density and more and more sophisticated social networks. While efforts continue in studying the large scale dissemination of contagious diseases, individual-based activity and behaviour study benefits not only disease transmission modelling but also the control, containment, and prevention decision making at the local scale. The potential for using tracking technologies to capture detailed space-time trajectories and model individual behaviour is increasing rapidly, as technological advances enable the manufacture of small, lightweight, highly sensitive, and affordable receivers and the routine use of location-aware devices has become widespread (e.g., smart cellular phones). The use of low-cost tracking devices in medical research has also been proved effective by more and more studies. This study describes the use of tracking devices to collect data of space-time trajectories and the spatiotemporal processing of such data to facilitate micro-scale flu transmission study. We also reports preliminary findings on activity patterns related to chances of influenza infection in a pilot study. Specifically, this study employed A-GPS tracking devices to collect data on a university campus. Spatiotemporal processing was conducted for data cleaning and segmentation. Processed data was validated with traditional activity diaries. The A-GPS data set was then used for visual explorations including density surface visualization and connection analysis to examine space-time activity patterns in relation to chances of influenza infection. When compared to diary data, the segmented tracking data demonstrated to be an effective alternative and showed greater accuracies in time as well as the details of routes taken by participants. A comparison of space-time activity patterns between participants who caught seasonal influenza and those who did not revealed interesting patterns. This study

Role of environmental factors in the timing of puberty

DEFF Research Database (Denmark)

Euling, S.Y.; Selevan, S.G.; Pescovitz, O.H.

2008-01-01

Puberty-timing measures have historically been used as indicators of adequate nutrition and growth. More recently, these measures have been examined in relation to exposure to estrogenic or antiandrogenic agents, as well as other environmental factors. The scientific community has debated whether...... puberty timing is occurring earlier today than in the mid-1900s in the United States and, if so, whether environmental factors play a role; however, no one has asked a multidisciplinary panel to resolve this question. Thus, a multidisciplinary expert panel jointly sponsored by the US Environmental...... Protection Agency, the National Institute of Environmental Health Sciences, and Serono Symposia International was convened to examine the evidence of a secular trend, identify potential environmental factors of concern, and identify research needs regarding environmental factors and puberty timing at "The...

Emergence of Space-Time Localization and Cosmic Decoherence:. More on Irreversible Time, Dark Energy, Anti-Matter and Black-Holes

Science.gov (United States)

Magnon, Anne

2005-04-01

A non geometric cosmology is presented, based on logic of observability, where logical categories of our perception set frontiers to comprehensibility. The Big-Bang singularity finds here a substitute (comparable to a "quantum jump"): a logical process (tied to self-referent and divisible totality) by which information emerges, focalizes on events and recycles, providing a transition from incoherence to causal coherence. This jump manufactures causal order and space-time localization, as exact solutions to Einstein's equation, where the last step of the process disentangles complex Riemann spheres into real null-cones (a geometric overturning imposed by self-reference, reminding us of our ability to project the cosmos within our mental sphere). Concepts such as antimatter and dark energy (dual entities tied to bifurcations or broken symmetries, and their compensation), are presented as hidden in the virtual potentialities, while irreversible time appears with the recycling of information and related flow. Logical bifurcations (such as the "part-totality" category, a quantum of information which owes its recycling to non localizable logical separations, as anticipated by unstability or horizon dependence of the quantum vacuum) induce broken symmetries, at the (complex or real) geometric level [eg. the antiselfdual complex non linear graviton solutions, which break duality symmetry, provide a model for (hidden) anti-matter, itself compensated with dark-energy, and providing, with space-time localization, the radiative gravitational energy (Bondi flux and related bifurcations of the peeling off type), as well as mass of isolated bodies]. These bifurcations are compensated by inertial effects (non geometric precursors of the Coriolis forces) able to explain (on logical grounds) the cosmic expansion (a repulsion?) and critical equilibrium of the cosmic tissue. Space-time environment, itself, emerges through the jump, as a censor to totality, a screen to incoherence (as

Time, Space and the History of Agricultural Landscapes

DEFF Research Database (Denmark)

Svenningsen, Stig Roar; Christensen, Andreas Aagaard

history, especially as the rate of changes in cultural landscapes has increased during the last 40 years as the result of the development in the agro-industrial sector. However landscape changes rarely occur as abrupt and sudden breaks, but more as gradual process over long time periods corresponding...... with development in farming technology, modes of production and social organization. The majority of sources material to landscape history are of geographic nature, such as cartographic material, aerial imagery, photographs and paintings and opposite to the gradual nature of changes in the landscape, most sources...... to the physical structure of landscapes has a fixed temporal nature depicting the landscape at time of record, often at different spatial scales. This creates a challenge for Environmental history of European agricultural landscapes to produce a framework, which can incorporate these differences in temporal...

The edge of space time

International Nuclear Information System (INIS)

Hawking, S.

1993-01-01

What happened at the beginning of the expansion of the universe. Did space time have an edge at the Big Bang. The answer is that, if the boundary conditions of the universe are that it has no boundary, time ceases to be well-defined in the very early universe as the direction ''north'' ceases to be well defined at the North Pole of the Earth. The quantity that we measure as time has a beginning but that does not mean spacetime has an edge, just as the surface of the Earth does not have an edge at the North Pole. 8 figs

Holographic analysis of dispersive pupils in space--time optics

International Nuclear Information System (INIS)

Calatroni, J.; Vienot, J.C.

1981-01-01

Extension of space--time optics to objects whose transparency is a function of the temporal frequency v = c/lambda is examined. Considering the effects of such stationary pupils on white light waves, they are called temporal pupils. It is shown that simultaneous encoding both in the space and time frequency domains is required to record pupil parameters. The space-time impulse response and transfer functions are calculated for a dispersive nonabsorbent material. An experimental method providing holographic recording of the dispersion curve of any transparent material is presented

Holographic analysis of dispersive pupils in space--time optics

Energy Technology Data Exchange (ETDEWEB)

Calatroni, J.; Vienot, J.C.

1981-06-01

Extension of space--time optics to objects whose transparency is a function of the temporal frequency v = c/lambda is examined. Considering the effects of such stationary pupils on white light waves, they are called temporal pupils. It is shown that simultaneous encoding both in the space and time frequency domains is required to record pupil parameters. The space-time impulse response and transfer functions are calculated for a dispersive nonabsorbent material. An experimental method providing holographic recording of the dispersion curve of any transparent material is presented.

Test Equal Bending by Gravity for Space and Time

Science.gov (United States)

Sweetser, Douglas

2009-05-01

For the simplest problem of gravity - a static, non-rotating, spherically symmetric source - the solution for spacetime bending around the Sun should be evenly split between time and space. That is true to first order in M/R, and confirmed by experiment. At second order, general relativity predicts different amounts of contribution from time and space without a physical justification. I show an exponential metric is consistent with light bending to first order, measurably different at second order. All terms to all orders show equal contributions from space and time. Beautiful minimalism is Nature's way.

The theory of space, time and gravitation

CERN Document Server

Fock, V

2015-01-01

The Theory of Space, Time, and Gravitation, 2nd Revised Edition focuses on Relativity Theory and Einstein's Theory of Gravitation and correction of the misinterpretation of the Einsteinian Gravitation Theory. The book first offers information on the theory of relativity and the theory of relativity in tensor form. Discussions focus on comparison of distances and lengths in moving reference frames; comparison of time differences in moving reference frames; position of a body in space at a given instant in a fixed reference frame; and proof of the linearity of the transformation linking two iner

Finite element method for time-space-fractional Schrodinger equation

Directory of Open Access Journals (Sweden)

Xiaogang Zhu

2017-07-01

Full Text Available In this article, we develop a fully discrete finite element method for the nonlinear Schrodinger equation (NLS with time- and space-fractional derivatives. The time-fractional derivative is described in Caputo's sense and the space-fractional derivative in Riesz's sense. Its stability is well derived; the convergent estimate is discussed by an orthogonal operator. We also extend the method to the two-dimensional time-space-fractional NLS and to avoid the iterative solvers at each time step, a linearized scheme is further conducted. Several numerical examples are implemented finally, which confirm the theoretical results as well as illustrate the accuracy of our methods.

Differential Space-Time Block Code Modulation for DS-CDMA Systems

Directory of Open Access Journals (Sweden)

Liu Jianhua

2002-01-01

Full Text Available A differential space-time block code (DSTBC modulation scheme is used to improve the performance of DS-CDMA systems in fast time-dispersive fading channels. The resulting scheme is referred to as the differential space-time block code modulation for DS-CDMA (DSTBC-CDMA systems. The new modulation and demodulation schemes are especially studied for the down-link transmission of DS-CDMA systems. We present three demodulation schemes, referred to as the differential space-time block code Rake (D-Rake receiver, differential space-time block code deterministic (D-Det receiver, and differential space-time block code deterministic de-prefix (D-Det-DP receiver, respectively. The D-Det receiver exploits the known information of the spreading sequences and their delayed paths deterministically besides the Rake type combination; consequently, it can outperform the D-Rake receiver, which employs the Rake type combination only. The D-Det-DP receiver avoids the effect of intersymbol interference and hence can offer better performance than the D-Det receiver.

Relativistic helicity and link in Minkowski space-time

International Nuclear Information System (INIS)

Yoshida, Z.; Kawazura, Y.; Yokoyama, T.

2014-01-01

A relativistic helicity has been formulated in the four-dimensional Minkowski space-time. Whereas the relativistic distortion of space-time violates the conservation of the conventional helicity, the newly defined relativistic helicity conserves in a barotropic fluid or plasma, dictating a fundamental topological constraint. The relation between the helicity and the vortex-line topology has been delineated by analyzing the linking number of vortex filaments which are singular differential forms representing the pure states of Banach algebra. While the dimension of space-time is four, vortex filaments link, because vorticities are primarily 2-forms and the corresponding 2-chains link in four dimension; the relativistic helicity measures the linking number of vortex filaments that are proper-time cross-sections of the vorticity 2-chains. A thermodynamic force yields an additional term in the vorticity, by which the vortex filaments on a reference-time plane are no longer pure states. However, the vortex filaments on a proper-time plane remain to be pure states, if the thermodynamic force is exact (barotropic), thus, the linking number of vortex filaments conserves

Quality-by-Design (QbD): An integrated process analytical technology (PAT) approach for a dynamic pharmaceutical co-precipitation process characterization and process design space development.

Science.gov (United States)

Wu, Huiquan; White, Maury; Khan, Mansoor A

2011-02-28

The aim of this work was to develop an integrated process analytical technology (PAT) approach for a dynamic pharmaceutical co-precipitation process characterization and design space development. A dynamic co-precipitation process by gradually introducing water to the ternary system of naproxen-Eudragit L100-alcohol was monitored at real-time in situ via Lasentec FBRM and PVM. 3D map of count-time-chord length revealed three distinguishable process stages: incubation, transition, and steady-state. The effects of high risk process variables (slurry temperature, stirring rate, and water addition rate) on both derived co-precipitation process rates and final chord-length-distribution were evaluated systematically using a 3(3) full factorial design. Critical process variables were identified via ANOVA for both transition and steady state. General linear models (GLM) were then used for parameter estimation for each critical variable. Clear trends about effects of each critical variable during transition and steady state were found by GLM and were interpreted using fundamental process principles and Nyvlt's transfer model. Neural network models were able to link process variables with response variables at transition and steady state with R(2) of 0.88-0.98. PVM images evidenced nucleation and crystal growth. Contour plots illustrated design space via critical process variables' ranges. It demonstrated the utility of integrated PAT approach for QbD development. Published by Elsevier B.V.

Pesticide exposure assessment in flowing waters – results for predicted environmental concentrations in some brooks in Germany

DEFF Research Database (Denmark)

Trapp, M.T.; Guerniche, D.G.; Bach, M.B.

2010-01-01

was to predict initial environmental concentrations in flowing water bodies after spray drift exposure. Based on this the downstream development of these concentrations over space and time with regard to dispersion processes was simulated (PECtwa, Time over Threshold). An adequate GIS-based software......The “Georisk”- project of the German Federal Environmental Agency forms the scientific basis for an integration of more realistic landscape based scenarios into the process of pesticide registration. Here, first results of geodata-based simulations are presented. The objective of the simulations...

Mathematical aspects of the discrete space-time hypothesis

International Nuclear Information System (INIS)

Sardanashvili, G.A.

1979-01-01

A hypothesis of a microcosm space discreteness is considered from the theoretical-mathematical point of view. The type of topological spaces, which formalizes representations on the discrete space-time, is determined. It is explained, how these spaces arise in physical models. The physical task, in which the discrete space could arise as a version of its solution, is considered. It is shown that the discrete structure of space can arise with a certain interaction type in the system, for example, with its considerable self-shielding, which can take place, in particular, in the particles or in the cosmological and astrophysical singularities

Modern integrated environmental monitoring and processing systems for nuclear facilities

International Nuclear Information System (INIS)

Oprea, I.

2000-01-01

The continuous activity to survey and monitor releases and the current radiation levels in the vicinity of a nuclear object is essential for person and environment protection. Considering the vast amount of information and data needed to keep an updated overview of a situation both during the daily surveillance work and during accident situations, the need for an efficient monitoring and processing system is evident. The rapid development, both in computer technology and in telecommunications, the evolution of fast and accurate computer codes enabling the on-line calculations improve the quality of decision-making in complex situations and assure a high efficiency. The monitoring and processing systems are used both for environmental protection and for controlling nuclear power plant emergency and post-accident situations. Such a system can offer information to the radiation management systems in order to assess the consequences of nuclear accidents and to establish a basis for right decisions in civil defense. The integrated environmental monitoring systems have as main task to record, collect, process and transmit the radiation levels and weather data, incorporating a number of stationary or mobile radiation monitoring equipment, weather parameter measuring station, an information processing center and the communication network, all running under a real-time operating system.They provide the automatic data collection on-line and off-line, remote diagnostic, advanced presentation techniques, including a graphically oriented executive support, which has the ability to respond to an emergency by geographical representation of the hazard zones on the map. The systems are based on local intelligent measuring and transmission units, simultaneous processing and data presentation using a real-time operating system for personal computers and geographical information system (GIS). All information can be managed directly from the map by multilevel data retrieving and

Time-dependent gravitating solitons in five dimensional warped space-times