EMP/GMD Phase 0 Report, A Review of EMP Hazard Environments and Impacts

Energy Technology Data Exchange (ETDEWEB)

Rivera, Michael Kelly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Backhaus, Scott N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Woodroffe, Jesse Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Henderson, Michael Gerard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bos, Randall J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nelson, Eric Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kelic, Andjelka [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-11-01

The purpose of this study is to determine methods to analyze the hazard environments, impacts, and consequences of different sources of electromagnetic pulse (EMP), including nuclear electromagnetic pulse (NEMP) and geomagnetic disturbance (GMD) on the U.S. electric power infrastructures and to use those methods to determine EMP and GMD events of concern. The study will be carried out in four phases, each of which will provide higher levels of analytic fidelity that focuses on those EMP/GMD sources and events that create significant consequences, or whose consequences are sufficiently uncertain, to require more in-depth study. This study will leverage the best experimental data; device, equipment and system models; and simulation tools currently available. This study focuses primarily on the bulk electric system (BES) including large generating stations, large power transformers, the transmission network, and transmission system protection. Electrical distribution systems may potentially be included, if warranted, after consideration of the consequences for the bulk power system.

Comparative EMP design practices

International Nuclear Information System (INIS)

Martin, L.C.

1975-01-01

A large amount of effort is devoted to the hardening of systems against various effects. The nuclear electromagnetic pulse (EMP) creates potentially severe protection problems in hardening against electromagnetic effects. Each hardening effort is usually supported through development or application of sets of rules, practices, constraints, etc., which aid in decision-making throughout the design process. Several excerpts from a few sets of EMP design rules and practices taken from relatively independent sources are presented for comparison of essential features and mode of expression. A general objective is to clarify some of the EMP practices present in general EMC work and to encourage further interchange of relevant information. (auth)

Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP) Attack: Critical National Infrastructures

National Research Council Canada - National Science Library

Foster, Jr., John S; Gjelde, Earl; Graham, William R; Hermann, Robert J; Kluepfel, Henry M; Lawson, Richard L; Soper, Gordon K; Wood, Lowell L; Woodard, Joan B

2008-01-01

...) attack on our critical national infrastructures. An earlier report, Report of the Commission to Assess the Threat to the United States from Electromagnetic Pulse (EMP), Volume 1: Executive Report (2004...

EMP at the Non-Proliferation Experiment

Energy Technology Data Exchange (ETDEWEB)

Bell, J. [AWE, Aldermaston (United Kingdom)

1994-12-31

This experiment presented an opportunity to field customized equipment designed to detect and record electromagnetic pulse (EMP) emanations from an explosion over a wide frequency range. Any data recorded could be used in conjunction with the seismic methods to further non-proliferation studies. No EMP emanations were detectable from the four sensors deployed outside the tunnel confines.

Ultrashort laser pulses and electromagnetic pulse generation in air and on dielectric surfaces

International Nuclear Information System (INIS)

Sprangle, P.; Penano, J.R.; Hafizi, B.; Kapetanakos, C.A.

2004-01-01

Intense, ultrashort laser pulses propagating in the atmosphere have been observed to emit sub-THz electromagnetic pulses (EMPS). The purpose of this paper is to analyze EMP generation from the interaction of ultrashort laser pulses with air and with dielectric surfaces and to determine the efficiency of conversion of laser energy to EMP energy. In our self-consistent model the laser pulse partially ionizes the medium, forms a plasma filament, and through the ponderomotive forces associated with the laser pulse, drives plasma currents which are the source of the EMP. The propagating laser pulse evolves under the influence of diffraction, Kerr focusing, plasma defocusing, and energy depletion due to electron collisions and ionization. Collective effects and recombination processes are also included in the model. The duration of the EMP in air, at a fixed point, is found to be a few hundred femtoseconds, i.e., on the order of the laser pulse duration plus the electron collision time. For steady state laser pulse propagation the flux of EMP energy is nonradiative and axially directed. Radiative EMP energy is present only for nonsteady state or transient laser pulse propagation. The analysis also considers the generation of EMP on the surface of a dielectric on which an ultrashort laser pulse is incident. For typical laser parameters, the power and energy conversion efficiency from laser radiation to EMP radiation in both air and from dielectric surfaces is found to be extremely small, -8 . Results of full-scale, self-consistent, numerical simulations of atmospheric and dielectric surface EMP generation are presented. A recent experiment on atmospheric EMP generation is also simulated

Bioelectromagnetic effects of EMP: Preliminary findings

Science.gov (United States)

Aldrich, T. E.; Easterly, C. E.; Gailey, P. C.; Hamilton, C. B.

1988-06-01

Facilities to simulate electromagnetic pulses (EMPs) are used to test military equipment and electrical communications devices for resistance to the effects of an EMP caused by an upper-atmospheric nuclear detonation. The rapid rise time and high field strengths (0.1 to 50 kV/m) of an EMP distinguish it from other electromagnetic phenomena. Certain types of EMP simulators also expose facility operators and members of the public to electromagnetic fields of varying intensity as do other natural sources such as the fields produced near a lightning bolt. Limited biological effects data have been collected to assess the potential EMP health hazards to humans. Evidence from the available database does not establish that EMPs represent either an occupational or a public health hazard. A critique is presented of the EMP research published to date in order to explore its limitations and similarities with related outcome experience from other electromagnetic field research. Laboratory research and multiple years of observations on workers in existing EMP manufacturing and simulation facilities suggest that there are no acute or short-term health effects. The occupational exposure guideline for EMP is 100 kV/m, which is far in excess of usual exposures with EMP simulators.

Power system EMP protection. Final report

International Nuclear Information System (INIS)

Marable, J.H.; Barnes, P.R.; Nelson, D.B.

1975-05-01

Voltage transients induced in electric power lines and control circuits by the electromagnetic pulse (EMP) from high-altitude nuclear detonations may cause widespread power failure and damage in electric power systems. This report contains a parametric study of EMP power line surges and discusses protective measures to minimize their effects. Since EMP surges have considerably greater rates of rise than lightning surges, recommended standards and test procedures are given to assure that surge arresters protect equipment from damage by EMP. Expected disturbances and damage to power systems are reviewed, and actions are presented which distribution companies can take to counter them. These include backup communications methods, stockpiling of vulnerable parts, repair procedures, and dispatcher actions to prevent blackout from EMP-caused instabilities. A long-range program is presented for improving distributors' protection against EMP. This involves employee training, hardware protection for power and control circuits, and improvement of plans for emergency action. (U.S.)

Nuclear magnetohydrodynamic EMP, solar storms, and substorms

International Nuclear Information System (INIS)

Rabinowitz, M.; Meliopoulous, A.P.S.; Glytsis, E.N.

1992-01-01

In addition to a fast electromagnetic pulse (EMP), a high altitude nuclear burst produces a relatively slow magnetohydrodynamic EMP (MHD EMP), whose effects are like those from solar storm geomagnetically induced currents (SS-GIC). The MHD EMP electric field E approx-lt 10 - 1 V/m and lasts approx-lt 10 2 sec, whereas for solar storms E approx-gt 10 - 2 V/m and lasts approx-gt 10 3 sec. Although the solar storm electric field is lower than MHD EMP, the solar storm effects are generally greater due to their much longer duration. Substorms produce much smaller effects than SS-GIC, but occur much more frequently. This paper describes the physics of such geomagnetic disturbances and analyzes their effects

Nuclear EMP induced chaos. [Effect of nuclear explosion on power and communication facilities

Energy Technology Data Exchange (ETDEWEB)

Dance, B

1983-04-01

It is anticipated that a single nuclear explosion, of adequate size, on the outside of the atmosphere would generate a pulse of sufficient intensity to damage communications equipment (including telephones, radio transmitters and receivers), and to disrupt main power supplies. This damage could be done by a very intense, short duration electro-magnetic pulse (EMP). The article discusses the generation and history of EMP, the test facilities that are needed for EMP test, and techniques that can be used to harden equipment against EMP. It is also important to protect extensive systems against EMP. The article points out that fibre-optics are very useful, because they are EMP resistant and a single fibre can also carry a very high data rate.

Experimental investigation on EMP effect of SRAM

International Nuclear Information System (INIS)

Han Jun; Xie Yanzhao; Zhai Aibin; Yao Zhibin

2010-01-01

The response of SRAM with different memory size at different read/write state was studied under EMP environment with pulse width of 50 ns, 350 ns and 1μs.The electric field amplitude of EMP ranges from 2.5 to 40 kV/m. It was found that the upset number has no obvious relation with memory size of SRAM and band width of EMP. The electric field amplitude is the crucial parameter leading to the upset effects. Further more, the upset effects of SRAM at read write state was much more seriously compared to the SRAM was not at read/write state. (authors)

Methods for Free-Space Ultra-Short Solitary EMP Measurement

Directory of Open Access Journals (Sweden)

Petr Drexler

2006-01-01

Full Text Available There are some suitable methods for ultra-short solitary electromagnetic pulses (EMP measurement. The EMPs are generated by high power microwave generators. The characteristic of EMPs is high power level (Pmax = 250 MW and very short time duration (tp Î <1, 60> ns. Special requirements for measurement methods are placed because of the specific EMPs properties.Two suitable methods for this application are presented in the paper. The first – calorimetric method, utilizes the thermal impacts of microwave absorption. The second method presented – magneto-optic method, use the Faraday’s magneto-optic effect as a sensor principle. It was realized combined calorimetric sensor and there were made some experimental EMP measurements with good results. The sensor utilizing magneto-optic method is in development.

EMP protection procedure for electrical/electronic systems

International Nuclear Information System (INIS)

Latorre, V.R.

1976-01-01

This paper presents a procedure for the protection engineer to follow in assessing a system with respect to its susceptibility to an electromagnetic pulse (EMP), and in determining whether the system requires protection. If the system is determined to be vulnerable to EMP, the procedure also indicates how to decide upon the most suitable protection scheme. The discussion centers on two flow charts, which illustrate the step-by-step procedure which utilizes the necessary ingredients of EMP protection engineering discussed in a previous paper. The description of the protection procedure is divided into two parts: the first dealing with issues on the macroscopic or large-scale system level, while the second is concerned with operations on the subsystem level or lower

Nuclear EMP induced chaos

Energy Technology Data Exchange (ETDEWEB)

Dance, B

1983-08-01

In the event of nuclear war, the availability of first class communications facilities and of reliable electricity supplies would be of absolutely vital importance to any of the population surviving the first onslaught not only for their own welfare, but also for the preservation of their nation's retaliation deterrent capability. However, it is to be expected that a single nuclear explosion of adequate size on the outside of the atmosphere would generate a pulse of sufficient intensity to damage communications equipment (including telephones, radio transmitters and receivers) and to interrupt main supplies. The situation caused by electromagnetic pulses (EMP) is discussed.

The integrated circuit IC EMP transient state disturbance effect experiment method investigates

International Nuclear Information System (INIS)

Li Xiaowei

2004-01-01

Transient state disturbance characteristic study on the integrated circuit, IC, need from its coupling path outset. Through cable (aerial) coupling, EMP converts to an pulse current voltage and results in the impact to the integrated circuit I/O orifice passing the cable. Aiming at the armament system construction feature, EMP effect to the integrated circuit, IC inside the system is analyzed. The integrated circuit, IC EMP effect experiment current injection method is investigated and a few experiments method is given. (authors)

Hardening techniques for nuclear generated EMPs: Pt. 1

International Nuclear Information System (INIS)

Anon.

1987-01-01

This article is intended as an introduction to the protection of electronic equipment against the effects of the electromagnetic pulse (EMP) generated by a nuclear explosion. For explosions at heights above 100 km the energy in the pulse is considerable over areas of many thousands of square metres. This constitutes a major threat to electronic equipments which have not been exposed to the consequences of closer nuclear explosions (namely blast, thermal and nuclear radiation)

Role of Off-Line-of-Sight Propagation in Geomagnetic EMP Formation

Energy Technology Data Exchange (ETDEWEB)

Kruger, Hans W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2016-05-23

The author’s synchrotron radiation based 3D geomagnetic EMP code MACSYNC has been used to explore the impact on pulse rise time and air conductivity of EMP propagation paths to the observer that are located off the direct line-of-sight (LOS) between gamma source and observer. This geometry is always present because, for an isotropic source, most the gammas are emitted at an angle with respect to the LOS. Computations for a 1 kt near-surface burst observed from space yield two principal findings: 1. The rise time is generated by the combined actions of a) electron spreading along the LOS due to the Compton electron emission angular distribution folded with electron multiple scattering effects, and b) radiation arrival time spreading due to length differences for different off-LOS propagation paths. The pulse rise time does not depend on the rise time of the conductivity. The conductivity rise time determines the pulse amplitude. 2. One-dimensional legacy EMP codes are inherently incapable of producing the correct pulse shape because they cannot treat the dependence of the conductivity on two dimensions, i.e. the radius from the source and the angle of the propagation path with the LOS. This divergence from one-dimensionality begins at a small fraction of a nanosecond for a sea-level burst. This effect will also be present in high-altitude bursts, however, determination of its onset time and magnitude requires high-altitude computations which have not yet been done.

Strategies, Protections and Mitigations for Electric Grid from Electromagnetic Pulse Effects

Energy Technology Data Exchange (ETDEWEB)

Foster, Rita Ann [Idaho National Lab. (INL), Idaho Falls, ID (United States); Frickey, Steven Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2016-01-01

The mission of DOE’s Office of Electricity Delivery and Energy Reliability (OE) is to lead national efforts to modernize the electricity delivery system, enhance the security and reliability of America’s energy infrastructure and facilitate recovery from disruptions to the energy supply. One of the threats OE is concerned about is a high-altitude electro-magnetic pulse (HEMP) from a nuclear explosion and eletro-magnetic pulse (EMP) or E1 pulse can be generated by EMP weapons. DOE-OE provides federal leadership and technical guidance in addressing electric grid issues. The Idaho National Laboratory (INL) was chosen to conduct the EMP study for DOE-OE due to its capabilities and experience in setting up EMP experiments on the electric grid and conducting vulnerability assessments and developing innovative technology to increase infrastructure resiliency. This report identifies known impacts to EMP threats, known mitigations and effectiveness of mitigations, potential cost of mitigation, areas for government and private partnerships in protecting the electric grid to EMP, and identifying gaps in our knowledge and protection strategies.

Nuclear EMP: key suppression device parameters for EMP hardening

International Nuclear Information System (INIS)

Durgin, D.L.; Brown, R.M.

1975-03-01

The electrical transients induced by EMP exhibit unique characteristics which differ considerably from transients associated with other phenomena such as lightning, switching, and circuit malfunctions. The suppression techniques developed to handle more common transients, though not necessarily the same devices, can be used for EMP damage protection. The suppression devices used for circuit level EMP protection are referred to as Terminal Protection Devices (TPD). Little detailed data describing the response of TPD's to EMP-related transients have been published. While most vendors publish specifications for TPD performance, there is little standardization of parameters and TPD response models are not available. This lack of parameter standardization has resulted in a proliferation of test data that is sometimes conflicting and often not directly comparable. This paper derives and/or defines a consistent set of parameters based on EMP circuit hardening requirements and on measurable component parameters and is concerned only with use of TPD's to prevent permanent damage. Three sets of parameters pertaining to pertinent TPD functional characteristics were defined as follows: standby parameters, protection parameters, and failure parameters. These parameters are used to evaluate a representative sample of TPD's and the results are presented in matrix form to facilitate the selection of devices for specific hardening problems

The development of the time dependence of the nuclear EMP electric field

International Nuclear Information System (INIS)

Eng, C.

2009-01-01

The nuclear electromagnetic pulse (EMP) electric field calculated with the legacy code CHAP is compared with the field given by an integral solution of Maxwell's equations, also known as the Jefimenko equation, to aid our current understanding on the factors that affect the time dependence of the EMP. For a fair comparison the CHAP current density is used as a source in the Jefimenko equation. At first, the comparison is simplified by neglecting the conduction current and replacing the standard atmosphere with a constant density air slab. The simplicity of the resultant current density aids in determining the factors that affect the rise, peak and tail of the EMP electric field versus time. The three dimensional nature of the radiating source, i.e. sources off the line-of-sight, and the time dependence of the derivative of the current density with respect to time are found to play significant roles in shaping the EMP electric field time dependence. These results are found to hold even when the conduction current and the standard atmosphere are properly accounted for. Comparison of the CHAP electric field with the Jefimenko electric field offers a direct validation of the high-frequency/outgoing wave approximation.

EMP protection technology interchange

International Nuclear Information System (INIS)

Martin, L.C.

1977-01-01

Investigation and assessment of the potential degrading and destructive effects associated with the nuclear electromagnetic (EMP) phenomena has created a large technological base. This base is indeed quite broad owing to the unique and system-pervasive character of the EMP. One of the aims of an emerging discipline, such as that associated with EMP, is to provide for adequate transfer and integration of the developing technology into the overall engineering community. The needs of the community and how EMP hardening and protection information can be transferred or exchanged are reviewed. Many of the current and generally available sources of information are listed, examples of interchange methods are provided, and problems of developing specifications, standards, and suitable guidelines for design and incorporation of protection are also discussed

Development of a new EMP code at LANL

Science.gov (United States)

Colman, J. J.; Roussel-Dupré, R. A.; Symbalisty, E. M.; Triplett, L. A.; Travis, B. J.

2006-05-01

A new code for modeling the generation of an electromagnetic pulse (EMP) by a nuclear explosion in the atmosphere is being developed. The source of the EMP is the Compton current produced by the prompt radiation (γ-rays, X-rays, and neutrons) of the detonation. As a first step in building a multi- dimensional EMP code we have written three kinetic codes, Plume, Swarm, and Rad. Plume models the transport of energetic electrons in air. The Plume code solves the relativistic Fokker-Planck equation over a specified energy range that can include ~ 3 keV to 50 MeV and computes the resulting electron distribution function at each cell in a two dimensional spatial grid. The energetic electrons are allowed to transport, scatter, and experience Coulombic drag. Swarm models the transport of lower energy electrons in air, spanning 0.005 eV to 30 keV. The swarm code performs a full 2-D solution to the Boltzmann equation for electrons in the presence of an applied electric field. Over this energy range the relevant processes to be tracked are elastic scattering, three body attachment, two body attachment, rotational excitation, vibrational excitation, electronic excitation, and ionization. All of these occur due to collisions between the electrons and neutral bodies in air. The Rad code solves the full radiation transfer equation in the energy range of 1 keV to 100 MeV. It includes effects of photo-absorption, Compton scattering, and pair-production. All of these codes employ a spherical coordinate system in momentum space and a cylindrical coordinate system in configuration space. The "z" axis of the momentum and configuration spaces is assumed to be parallel and we are currently also assuming complete spatial symmetry around the "z" axis. Benchmarking for each of these codes will be discussed as well as the way forward towards an integrated modern EMP code.

[Apoptosis of human lung carcinoma cell line GLC-82 induced by high power electromagnetic pulse].

Science.gov (United States)

Cao, Xiao-zhe; Zhao, Mei-lan; Wang, De-wen; Dong, Bo

2002-09-01

Electromagnetic pulse (EMP) could be used for sterilization of food and the efficiency is higher than 2450 MHz continuous microwave done. This study was designed to evaluate the effect of electromagnetic pulse (EMP) on apoptosis of human lung carcinoma cell line GLC-82, so that to explore and develop therapeutic means for cancer. The injury changes in GLC-82 cells after irradiated with EMP (electric field intensity was 60 kV/m, 5 pulses/2 min) were analyzed by cytometry, MTT chronometry, and flow cytometry. The immunohistochemical SP staining was used to determine the expressions of bcl-2 protein and p53 protein. The stained positive cells were analyzed by CMIAS-II image analysis system at a magnification 400. All data were analyzed by SPSS8.0 software. EMP could obviously inhibited proliferation and activity of lung carcinoma cell line GLC-82. The absorbance value (A570) of MTT decreased immediately, at 0 h, 1 h, and 6 h after the GLC-82 cells irradiated by EMP as compared with control group. The highest apoptosis rate was found to reach 13.38% by flow cytometry at 6 h after EMP irradiation. Down-regulation of bcl-2 expression and up-regulation of p53 expression were induced by EMP. EMP promotes apoptosis of GLC-82 cells. At same time, EMP can down-regulate bcl-2 expression and up-regulate p53 expression in GLC-82 cells. The bcl-2 and the p53 protein may involve the apoptotic process.

Numerical simulation of compact intracloud discharge and generated electromagnetic pulse

Science.gov (United States)

Babich, L. P.; Bochkov, E. I.; Kutsyk, I. M.

2015-06-01

Using the concept of the relativistic runaway electron avalanche, numerical simulation of compact intracloud discharge as a generator of powerful natural electromagnetic pulses (EMPs) in the HF-UHF range was conducted. We evaluated the numbers of electrons initiating the avalanche, with which the calculated EMP characteristics are consistent with measured ones. The discharge capable of generating EMPs produces runaway electrons in numbers close to those in the source of terrestrial γ-flashes (TGF) registered in the nearest space, which may be an argument for a joint EMP and TGF source.

On the electromagnetic pulse generated by exo-atmospheric nuclear detonations

International Nuclear Information System (INIS)

Leuthaeuser, K.D.

1983-01-01

When gamma rays produced by high altitude nuclear weapons explosions interact with the atmosphere they generate an electromagnetic pulse (EMP) propagating towards the earth's surface. The EMP covers large areas of millions of km 2 and reaches peak electric fields of more than 50 kV/m which may couple into all kinds of conducting systems. The present paper deals with a simple model to calculate EMP fields basing on Maxwell's equations. (orig.)

Effects of electromagnetic pulse exposure on gelatinase of blood-brain barrier in vitro.

Science.gov (United States)

Zhou, Yan; Qiu, Lian-Bo; An, Guang-Zhou; Zhou, Jia-Xing; Du, Le; Ma, Ya-Hong; Guo, Guo-Zhen; Ding, Gui-Rong

2017-01-01

The biological effects of electromagnetic pulse (EMP) on the brain have been focused on for years. It was reported that gelatinase played an important role in maintaining brain function through regulating permeability in the blood-brain barrier (BBB). To investigate the effects of EMP on gelatinase of BBB, an in vitro BBB model was established using primary cultured rat brain microvascular endothelial cells (BMVEC), astrocytes and half-contact culture of these cells in a transwell chamber. Cultured supernatant and cells were collected at different time points after exposure to EMP (peak intensity 400 kV/m, rise time 10 ns, pulse width 350 ns, 0.5 pps and 200 pulses). Protein levels of cellular gelatinase MMP-2 and MMP-9, and endogenous inhibitor TIMP-1 and TIMP-2 were detected by Western blot. The activity of gelatinase in culture supernatant was detected by gelatin zymography. It was found that compared with the sham-exposed group, the protein level of MMP-2 was significantly increased at 6 h (p < 0.05), and the protein level of its endogenous inhibitor TIMP-2 did not change after EMP exposure. In addition, the protein levels of MMP-9 and its endogenous inhibitor TIMP-1 did not change after EMP exposure. Gelatin zymography results showed that the activity of MMP-2 in the inner pool and the outer pool of the transwell chamber was significantly increased at 6 h after EMP exposure compared with that of the sham group. These results suggested that EMP exposure could affect the expression and activity of MMP-2 in the BBB model.

Endothelial microparticles (EMP in physiology and pathology

Directory of Open Access Journals (Sweden)

Ewa Sierko

2015-08-01

Full Text Available Endothelial microparticles (EMP are released from endothelial cells (ECs in the process of activation and/or apoptosis. They harbor adhesive molecules, enzymes, receptors and cytoplasmic structures and express a wide range of various constitutive antigens, typical for ECs, at their surface. Under physiological conditions the concentration of EMP in the blood is clinically insignificant. However, it was reported that under pathological conditions EMP concentration in the blood might slightly increase and contribute to blood coagulation, angiogenesis and inflammation. It has been shown that EMP directly and indirectly contribute to the activation of blood coagulation. Endothelial microparticles directly participate in blood coagulation through their surface tissue factor (TF – a major initiator of blood coagulation. Furthermore, EMP exhibit procoagulant potential via expression of negatively charged phospholipids at their surface, which may promote assembly of coagulation enzymes (TF/VII, tenases and prothrombinase complexes, leading to thrombus formation. In addition, they provide a binding surface for coagulation factors: IXa, VIII, Va and IIa. Moreover, it is possible that EMP transfer TF from TF-bearing EMP to activated platelets and monocytes by binding them through adhesion molecules. Also, EMP express von Willebrand factor, which may facilitate platelet aggregation. Apart from their procoagulant properties, it was demonstrated that EMP may express adhesive molecules and metalloproteinases (MMP-2, MMP-9 at their surface and release growth factors, which may contribute to angiogenesis. Additionally, surface presence of C3 and C4 – components of the classical pathway – suggests pro-inflammatory properties of these structures. This article contains a summary of available data on the biology and pathophysiology of endothelial microparticles and their potential role in blood coagulation, angiogenesis and inflammation.

Efficient process migration in the EMPS multiprocessor system

NARCIS (Netherlands)

van Dijk, G.J.W.; Gils, van M.J.

1992-01-01

The process migration facility in the Eindhoven multiprocessor system (EMPS) is presented. In the EMPS system, mailboxes are used for interprocess communication. These mailboxes provide transparency of location for communicating processes. The major advantages of mailbox communication in the EMPS

Time-domain simulation and waveform reconstruction for shielding effectiveness of materials against electromagnetic pulse

International Nuclear Information System (INIS)

Hu, Xiao-feng; Chen, Xiang; Wei, Ming

2013-01-01

Shielding effectiveness (SE) of materials of current testing standards is often carried out by using continuous-wave measurement and amplitude-frequency characteristics curve is used to characterize the results. However, with in-depth study of high-power electromagnetic pulse (EMP) interference, it was discovered that only by frequency-domain SE of materials cannot be completely characterized by shielding performance of time-domain pulsed-field. And there is no uniform testing methods and standards of SE of materials against EMP. In this paper, the method of minimum phase transfer function is used to reconstruct shielded time-domain waveform based on the analysis of the waveform reconstruction method. Pulse of plane waves through an infinite planar material is simulated by using CST simulation software. The reconstructed waveform and simulation waveform is compared. The results show that the waveform reconstruction method based on the minimum phase can be well estimated EMP waveform through the infinite planar materials.

Wavelet-Based Signal Processing of Electromagnetic Pulse Generated Waveforms

National Research Council Canada - National Science Library

Ardolino, Richard S

2007-01-01

This thesis investigated and compared alternative signal processing techniques that used wavelet-based methods instead of traditional frequency domain methods for processing measured electromagnetic pulse (EMP) waveforms...

Protecting the Power Grid From Electromagnetic Pulses

Science.gov (United States)

Simpson, Sarah

2004-10-01

A nuclear explosion high in the Earth's atmosphere does no immediate known harm to living things, but the resulting electromagnetic pulse (EMP) from a single detonation could degrade 70 percent or more of the country's electrical service in an instant, warns the Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack, which presented its findings to the U.S. Congress in July.

Survey of pork, poultry, coffee, beer and pulses for ochratoxin A

DEFF Research Database (Denmark)

Jørgensen, Kevin

1998-01-01

Surveys have been carried out to estimate the levels of ochratoxin A in pork, poultry, coffee, beer and pulses.. A total of 286 samples were analysed The results show that compared with cereals and cereal products the contribution from the foods surveyed to the total intake of ochratoxin A by the......Surveys have been carried out to estimate the levels of ochratoxin A in pork, poultry, coffee, beer and pulses.. A total of 286 samples were analysed The results show that compared with cereals and cereal products the contribution from the foods surveyed to the total intake of ochratoxin...

analysis of large electromagnetic pulse simulators using the electric field integral equation method in time domain

International Nuclear Information System (INIS)

Jamali, J.; Aghajafari, R.; Moini, R.; Sadeghi, H.

2002-01-01

A time-domain approach is presented to calculate electromagnetic fields inside a large Electromagnetic Pulse (EMP) simulator. This type of EMP simulator is used for studying the effect of electromagnetic pulses on electrical apparatus in various structures such as vehicles, a reoplanes, etc. The simulator consists of three planar transmission lines. To solve the problem, we first model the metallic structure of the simulator as a grid of conducting wires. The numerical solution of the governing electric field integral equation is then obtained using the method of moments in time domain. To demonstrate the accuracy of the model, we consider a typical EMP simulator. The comparison of our results with those obtained experimentally in the literature validates the model introduced in this paper

The electromagnetic pulse (EMP) as a danger for the world of electronics

International Nuclear Information System (INIS)

Horak, O.

1984-01-01

After discussing the characteristics and formation of a nuclear electromagnetic pulse, the author considers the effects such a pulse would have on various types of electronic systems. Finally he discusses what protection there is against such pulses. (Auth.)

Electromagnetic pulse coupling through an aperture into a two-parallel-plate region

Science.gov (United States)

Rahmat-Samii, Y.

1978-01-01

Analysis of electromagnetic-pulse (EMP) penetration via apertures into cavities is an important study in designing hardened systems. In this paper, an integral equation procedure is developed for determining the frequency and consequently the time behavior of the field inside a two-parallel-plate region excited through an aperture by an EMP. Some discussion of the numerical results is also included in the paper for completeness.

Nuclear pulse. II - Ensuring delivery of the doomsday signal

Science.gov (United States)

Broad, W. J.

1981-06-01

The ability of the communications systems on which U.S. strategic forces depend to survive the electromagnetic pulse (EMP) effects of a nuclear blast in the upper atmosphere is examined. It is shown that the Bell system telephone network, Autovon, on which much military communication presently depends, is especially vulnerable to EMP; while satellite and microwave communications networks are expected to be more resistant to attack. Satellites are, though, vulnerable to killer-satellite attack. Much promise is seen in the conversion of ground communications links to fiber-optic form, which is inherently highly resistant to EMP. A nuclear bomb detonated 200 miles above Nebraska would affect communications equipment throughout the contiguous U.S. with peak fields of 500,000 volts/meter.

Steroid hormone regulation of EMP2 expression and localization in the endometrium

Directory of Open Access Journals (Sweden)

Williams Carmen J

2008-04-01

Full Text Available Abstract Background The tetraspan protein epithelial membrane protein-2 (EMP2, which mediates surface display of diverse proteins, is required for endometrial competence in blastocyst implantation, and is uniquely correlated with poor survival from endometrial adenocarcinoma tumors. Because EMP2 is differentially expressed in the various stages of the murine and human estrous cycle, we tested the hypothesis that the steroid hormones progesterone and estrogen influence EMP2 expression and localization. Methods Frozen human proliferative and secretory endometrium were collected and analyzed for EMP2 expression using SDS-PAGE/Western blot analysis. The response of EMP2 to progesterone and estradiol was determined using a combination of real-time PCR, SDS-PAGE/Western blot analysis, and confocal immunofluorescence in the human endometrial carcinoma cell line RL95-2. To confirm the in vitro results, ovariectomized mice were treated with progesterone or estradiol, and EMP2 expression was analyzed using immunohistochemistry. Results Within normal human endometrium, EMP2 expression is upregulated in the secretory phase relative to the proliferative phase. To understand the role of steroid hormones on EMP2 expression, we utilized RL95-2 cells, which express both estrogen and progesterone receptors. In RL95-2 cells, both estradiol and progesterone induced EMP2 mRNA expression, but only progesterone induced EMP2 protein expression. To compare steroid hormone regulation of EMP2 between humans and mice, we analyzed EMP2 expression in ovarectomized mice. Similar to results observed in humans, progesterone upregulated endometrial EMP2 expression and induced EMP2 translocation to the plasma membrane. Estradiol did not promote translocation to the cell surface, but moderately induced EMP2 expression in cytoplasmic compartments in vivo. Conclusion These findings suggest that targeting of EMP2 to specific locations under the influence of these steroid hormones may

Experimental research for γ-ray interference threshold effect of high electromagnetic pulse sensor

International Nuclear Information System (INIS)

Meng Cui; Chen Xiangyue; Nie Xin; Xiang Hui; Guo Xiaoqiang; Mao Congguang; Cheng Jianping; Ni Jianping

2007-01-01

The high electromagnetic pulse (EMP) sensor using optical-fiber to transmit signal can restrain electromagnetic interference. The Compton electrons scattered by γ-ray irradiated from nuclear explosion or nuclear explosion simulator can generate high EMP, γ-ray can penetrate the shielding box and irradiate the integrated circuit directly. The γ-ray irradiation effect includes interference, latch up and burn out, these will make the measurement result unbelievable. In this paper, the experimental method researching the γ-ray irradiation effect of high electromagnetic pulse sensor on Qiangguang-I accelerator is introduced. The γ-ray dose rate interference threshold is 2 x 10 6 Gy/s. (authors)

Nuclear pulse. I - Awakening to the chaos factor

Science.gov (United States)

Broad, W. J.

1981-05-01

The discovery of the significance of the high-voltage wave termed electromagnetic pulse (EMP), which occurs following the high-altitude detonation of a nuclear device, is discussed. The disruptions to the street lights, burglar alarms and circuit breakers of Hawaii caused by the detonation of a nuclear device 248 mi above Johnson Island in the Pacific in July, 1962 are described and attributed to the Compton electrons produced by the impact of gamma rays from the nuclear explosion on air in the upper atmosphere. It is pointed out, however, that at the time of the explosion, most communications systems were based on vacuum tube and electromechanical technology, which is about 10,000,000 times harder against EMP than integrated solid-state circuitry, and thus the threat posed by EMP to the power grid and communications capabilities was not apparent. Efforts undertaken to harden discrete (missile) and communications systems against EMP are outlined for the example of the Safeguard ABM system, and difficulties are pointed out. Soviet awareness of EMP is considered, and the discovery of vacuum tubes on board the state-of-the-art Foxbat MiG interceptor flown into Japan is noted as a possible indicator of this awareness. It is concluded that the problem of EMP will increase in significance as semiconductor electronics proliferates.

Performa Supply Chain Emping Melinjo di Kabupaten Bantul Daerah Istimewa Yogyakarta

Directory of Open Access Journals (Sweden)

Eni Istiyanti

2017-07-01

Full Text Available Emping melinjo was one of the agroindustry-products that had great potential to be developed. The industry of emping melinjo contributed more on economic growth in the reason of creating jobs and alleviate poverty. The purpose of this study was to describe the performance of supply chain of emping melinjo from upstream to downstream and analyze the efficiency of supply chain of emping melinjo in Bantul regency. Field study to obtain primary data was done through interviews with the practitioners of emping melinjo supply chain (including farmers and merchants of melinjo as well as producers and retailers of melinjo chips. The results of field studies then tabulated and analyzed descriptively and quantitatively using Linear Programming. The analysis showed that there were 37 supply chain networks of emping melinjo in Bantul. The practitioners of upstream supply chain were melinjo farmers, middlemen, traders, wholesalers, and retailers, while in the downstream, were emping melinjo producers, traders, small traders, wholesalers, retailers and consumers. The activities of the doer of emping melinjo supply chain includes purchasing, sales, harvesting, packaging, packing, stripping, storage, loading and unloading, transporting, sorting and grading. The flow of products and money in the supply chain of emping melinjo run smoothly, while the flow of information was sluggish. Based on linear programming analysis the cost of supply chain of emping melinjo would reach minimum level at Rp33,969,264 per week if the production of emping melinjo as many as 25 361 kg per week wich was distributed using 22 networks.

Absorption of short-pulse electromagnetic energy by a resistively loaded straight wire

International Nuclear Information System (INIS)

Miller, E.K.; Deadrick, F.J.; Landt, J.A.

1975-01-01

Absorption of short-pulse electromagnetic energy by a resistively loaded straight wire is examined. Energy collected by the wire, load energy, peak load currents, and peak load voltages are found for a wide range of parameters, with particular emphasis on nuclear electromagnetic pulse (EMP) phenomena. A series of time-sequenced plots is used to illustrate pulse propagation on wires when loads and wire ends are encountered

Numerical simulation of narrow bipolar electromagnetic pulses generated by thunderstorm discharges

Science.gov (United States)

Bochkov, E. I.; Babich, L. P.; Kutsyk, I. M.

2013-07-01

Using the concept of avalanche relativistic runaway electrons (REs), we perform numerical simulations of compact intracloud discharge (CID) as a generator of powerful natural electromagnetic pulses (EMPs) in the HF-VHF range, called narrow bipolar pulses (NBPs). For several values of the field overvoltage and altitude at which the discharge develops, the numbers of seed electrons initiating the avalanche are evaluated, with which the calculated EMP characteristics are consistent with the measured NBP parameters. We note shortcomings in the hypothesis assuming participation of cosmic ray air showers in avalanche initiation. The discharge capable of generating NBPs produces REs in numbers close to those in the source of terrestrial γ-ray flashes (TGFs), which can be an argument in favor of a unified NBP and TGF source.

Numerical simulation of narrow bipolar electromagnetic pulses generated by thunderstorm discharges

International Nuclear Information System (INIS)

Bochkov, E. I.; Babich, L. P.; Kutsyk, I. M.

2013-01-01

Using the concept of avalanche relativistic runaway electrons (REs), we perform numerical simulations of compact intracloud discharge (CID) as a generator of powerful natural electromagnetic pulses (EMPs) in the HF-VHF range, called narrow bipolar pulses (NBPs). For several values of the field overvoltage and altitude at which the discharge develops, the numbers of seed electrons initiating the avalanche are evaluated, with which the calculated EMP characteristics are consistent with the measured NBP parameters. We note shortcomings in the hypothesis assuming participation of cosmic ray air showers in avalanche initiation. The discharge capable of generating NBPs produces REs in numbers close to those in the source of terrestrial γ-ray flashes (TGFs), which can be an argument in favor of a unified NBP and TGF source

Studies of exposure of rabbits to electromagnetic pulsed fields

International Nuclear Information System (INIS)

Cleary, S.F.; Nickless, F.; Liu, L.M.; Hoffman, R.

1980-01-01

Dutch rabbits were acutely exposed to electromagnetic pulsed (EMP) fields (pulse duration 0.4 mus, field strengths of 1--2 kV/cm and pulse repetition rates in the range of 10 to 38 Hz) for periods of up to two hours. The dependent variables investigated were pentobarbital-induced sleeping time and serum chemistry (including serum triglycerides, creatine phosphokinase (CPK) isoenzymes, and sodium and potassium). Core temperature measured immediately pre-exposure and postexposure revealed no exposure-related alterations. Over the range of field strengths and pulse durations investigated no consistent, statistically significant alterations were found in the end-points investigated

An Approach for Effect Analysis of Electromagnetic Pulse in Operating NPPs

International Nuclear Information System (INIS)

Ryu, Ho Sun; Ye, Song Hae; Kim, Minyi; Lee, Euijong

2016-01-01

Recently, there is a growing Electromagnetic Pulse (EMP) threat caused by North Korea’s nuclear weapons and unmanned aerial vehicles (UAVs). KHNP CRI is currently conducting a research project that will evaluate the safety of domestic nuclear power plants (NPPs) against EMP effects and prepare safety measures to counter vulnerable points. We will instead use simulation tools to evaluate the electromagnetic shielding ability and the conductivity of cables through vulnerable points in NPPs. Through a study of electromagnetic simulation techniques and tools, this paper suggests a simulation method for analysis of EMP effects in operating NPPs. Although 3D tools are relatively accurate, is difficult to use only 3D tools to simulate EMP effects for huge and complex structures such as NPPs. It is more efficient in terms of cost and time to use a 3D tool and an EMT tool for the simulation of such structures. We have compared the advantages and disadvantages of various methods and have selected the most appropriate tools; we will proceed in our next paper with the simulation of EMP effects

An Approach for Effect Analysis of Electromagnetic Pulse in Operating NPPs

Energy Technology Data Exchange (ETDEWEB)

Ryu, Ho Sun; Ye, Song Hae; Kim, Minyi; Lee, Euijong [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

Recently, there is a growing Electromagnetic Pulse (EMP) threat caused by North Korea’s nuclear weapons and unmanned aerial vehicles (UAVs). KHNP CRI is currently conducting a research project that will evaluate the safety of domestic nuclear power plants (NPPs) against EMP effects and prepare safety measures to counter vulnerable points. We will instead use simulation tools to evaluate the electromagnetic shielding ability and the conductivity of cables through vulnerable points in NPPs. Through a study of electromagnetic simulation techniques and tools, this paper suggests a simulation method for analysis of EMP effects in operating NPPs. Although 3D tools are relatively accurate, is difficult to use only 3D tools to simulate EMP effects for huge and complex structures such as NPPs. It is more efficient in terms of cost and time to use a 3D tool and an EMT tool for the simulation of such structures. We have compared the advantages and disadvantages of various methods and have selected the most appropriate tools; we will proceed in our next paper with the simulation of EMP effects.

[The effects of electromagnetic pulse on fluidity and lipid peroxidation of mitochondrial membrane].

Science.gov (United States)

Wang, Changzhen; Cong, Jianbo; Xian, Hong; Cao, Xiaozhe; Sun, Cunpu; Wu, Ke

2002-08-01

To study the effects of intense electromagnetic pulse(EMP) on the biological effects of mitochondrial membrane. Rat liver mitochondrial suspension was exposed to EMP at 60 kV/m level. The changes of membrane lipid fluidity and membrane protein mobility were detected by ESR and spin label technique. Malondialdehyde(MDA) was detected by spectrophotometer. The mobility of membrane protein decreased significantly(P < 0.05). Correlation time (tau c) of control group was (0.501 +/- 0.077) x 10(-9)s, and tau c of EMP group was (0.594 +/- 0.049) x 10(-9)s, indicating that the mobility of protein was restricted. The fluidity of mitochondrial membrane increased significantly(P < 0.05) at the same time. Order parameter(S) of mitochondrial membrane lipid in control group was 0.63 +/- 0.01, while S of EMP group was 0.61 +/- 0.01(P < 0.05). MDA decreased significantly. The mobility and lipid peroxidation of mitochondrial membrane may be disturbed after EMP exposure.

Preventing Electromagnetic Pulse Irradiation Damage on Testis Using Selenium-rich Cordyceps Fungi. A Preclinical Study in Young Male Mice.

Science.gov (United States)

Miao, Xia; Wang, Yafeng; Lang, Haiyang; Lin, Yanyun; Guo, Qiyan; Yang, Mingjuan; Guo, Juan; Zhang, Yanjun; Zhang, Jie; Liu, Junye; Liu, Yaning; Zeng, Lihua; Guo, Guozhen

2017-02-01

Networked 21st century society, globalization, and communications technologies are paralleled by the rise of electromagnetic energy intensity in our environments and the growing pressure of the environtome on human biology and health. The latter is the entire complement of environmental factors, including the electromagnetic energy and the technologies that generate them, enacting on the digital citizen in the new century. Electromagnetic pulse (EMP) irradiation might have serious damaging effects not only on electronic equipment but also in the whole organism and reproductive health, through nonthermal effects and oxidative stress. We sought to determine whether EMP exposure (1) induces biological damage on reproductive health and (2) the extent to which selenium-rich Cordyceps fungi (daily coadministration) offer protection on the testicles and spermatozoa. In a preclinical randomized study, 3-week-old male BALB/c mice were repeatedly exposed to EMP (peak intensity 200 kV/m, pulse edge 3.5 ns, pulse width 15 ns, 0.1 Hz, and 400 pulses/day) 5 days per week for four consecutive weeks, with or without coadministration of daily selenium-rich Cordyceps fungi (100 mg/kg). Testicular index and spermatozoa formation were measured at baseline and 1, 7, 14, 28, and 60 day time points after EMP exposure. The group without Cordyceps cotreatment displayed decreased spermatozoa formation, shrunk seminiferous tubule diameters, and diminished antioxidative capacity at 28 and 60 days after exposure (p digital citizenship.

Multi probes measurements at the PALS Facility Research Centre during high intense laser pulse interactions with various target materials

Directory of Open Access Journals (Sweden)

De Marco Massimo

2018-01-01

Full Text Available During the interaction of high intense laser pulse with solid target, a large amount of hot electrons is produced and a giant Electromagnetic Pulse (EMP is generated due to the current flowing into the system target–target holder, as well as due to the escaping charged particles in vacuum. EMP production for different target materials is investigated inside and outside the target chamber, using monopole antenna, super wide-band microstrip antenna and Moebius antenna. The EMP consists in a fast transient magnetic field lasting hundreds of nanosecond with frequencies ranging from MHz to tens of GHz. Measurements of magnetic field and return target current in the range of kA were carried out by an inductive target probe (Cikhardt J. et al. Rev. Sci. Instrum. 85 (2014 103507.

High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

National Research Council Canada - National Science Library

Wilson, Clay

2006-01-01

Electromagnetic Pulse (EMP) is an instantaneous, intense energy field that can disrupt at a distance numerous electrical systems and high technology microcircuits that are especially sensitive to power surges...

The effects of corona on current surges induced on conducting lines by EMP: A comparison of experiment data with results of analytic corona models

Science.gov (United States)

Blanchard, J. P.; Tesche, F. M.; McConnell, B. W.

1987-09-01

An experiment to determine the interaction of an intense electromagnetic pulse (EMP), such as that produced by a nuclear detonation above the Earth's atmosphere, was performed in March, 1986 at Kirtland Air Force Base near Albuquerque, New Mexico. The results of that experiment have been published without analysis. Following an introduction of the corona phenomenon, the reason for interest in it, and a review of the experiment, this paper discusses five different analytic corona models that may model corona formation on a conducting line subjected to EMP. The results predicted by these models are compared with measured data acquired during the experiment to determine the strengths and weaknesses of each model.

High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

National Research Council Canada - National Science Library

Wilson, Clay

2008-01-01

Electromagnetic Pulse (EMP) is an instantaneous, intense energy field that can overload or disrupt at a distance numerous electrical systems and high technology microcircuits, which are especially sensitive to power surges...

Measurement of electromagnetic pulses generated during interactions of high power lasers with solid targets

International Nuclear Information System (INIS)

De Marco, M.; Krása, J.; Margarone, D.; Giuffrida, L.; Vrana, R.; Velyhan, A.; Korn, G.; Weber, S.; Cikhardt, J.; Pfeifer, M.; Krouský, E.; Ullschmied, J.; Ahmed, H.; Borghesi, M.; Kar, S.; Limpouch, J.; Velardi, L.; Side, D. Delle; Nassisi, V.

2016-01-01

A target irradiated with a high power laser pulse, blows off a large amount of charge and as a consequence the target itself becomes a generator of electromagnetic pulses (EMP) owing to high return current flowing to the ground through the target holder. The first measurement of the magnetic field induced by the neutralizing current reaching a value of a few kA was performed with the use of an inductive target probe at the PALS Laser Facility (Cikhardt et al. Rev. Sci. Instrum. 85 (2014) 103507). A full description of EMP generation should contain information on the spatial distribution and temporal variation of the electromagnetic field inside and outside of the interaction chamber. For this reason, we consider the interaction chamber as a resonant cavity in which different modes of EMP oscillate for hundreds of nanoseconds, until the EMP is transmitted outside through the glass windows and EM waves are attenuated. Since the experimental determination of the electromagnetic field distribution is limited by the number of employed antennas, a mapping of the electromagnetic field has to be integrated with numerical simulations. Thus, this work reports on a detailed numerical mapping of the electromagnetic field inside the interaction chamber at the PALS Laser Facility (covering a frequency spectrum from 100 MHz to 3 GHz) using the commercial code COMSOL Multiphysics 5.2. Moreover we carried out a comparison of the EMP generated in the parallelepiped-like interaction chamber used in the Vulcan Petawatt Laser Facility at the Rutherford Appleton Laboratory, against that produced in the spherical interaction chamber of PALS.

FPGA-based Upgrade to RITS-6 Control System, Designed with EMP Considerations

International Nuclear Information System (INIS)

Anderson, Harold D.; Williams, John T.

2009-01-01

The existing control system for the RITS-6, a 20-MA 3-MV pulsed-power accelerator located at Sandia National Laboratories, was built as a system of analog switches because the operators needed to be close enough to the machine to hear pulsed-power breakdowns, yet the electromagnetic pulse (EMP) emitted would disable any processor-based solutions. The resulting system requires operators to activate and deactivate a series of 110-V relays manually in a complex order. The machine is sensitive to both the order of operation and the time taken between steps. A mistake in either case would cause a misfire and possible machine damage. Based on these constraints, a field-programmable gate array (FPGA) was chosen as the core of a proposed upgrade to the control system. An FPGA is a series of logic elements connected during programming. Based on their connections, the elements can mimic primitive logic elements, a process called synthesis. The circuit is static; all paths exist simultaneously and do not depend on a processor. This should make it less sensitive to EMP. By shielding it and using good electromagnetic interference-reduction practices, it should continue to operate well in the electrically noisy environment. The FPGA has two advantages over the existing system. In manual operation mode, the synthesized logic gates keep the operators in sequence. In addition, a clock signal and synthesized countdown circuit provides an automated sequence, with adjustable delays, for quickly executing the time-critical portions of charging and firing. The FPGA is modeled as a set of states, each state being a unique set of values for the output signals. The state is determined by the input signals, and in the automated segment by the value of the synthesized countdown timer, with the default mode placing the system in a safe configuration. Unlike a processor-based system, any system stimulus that results in an abort situation immediately executes a shutdown, with only a tens

78 FR 35073 - Compass Efficient Model Portfolios, LLC and Compass EMP Funds Trust; Notice of Application

Science.gov (United States)

2013-06-11

... Balanced Fund, Compass EMP Multi-Asset Growth Fund, Compass EMP Alternative Strategies Fund, Compass EMP Balanced Volatility Weighted Fund, Compass EMP Growth Volatility Weighted Fund, and Compass EMP... Efficient Model Portfolios, LLC and Compass EMP Funds Trust; Notice of Application June 4, 2013. AGENCY...

A research program to assess the impact of the electromagnetic pulse on electric power systems

Science.gov (United States)

McConnell, B. W.; Barnes, P. R.

A strong electromagnetic pulse (EMP) with an electric-field component on the order of tens of kilovolts per meter is produced by a nuclear detonation in or above the atmosphere. This paper presents an overview and a summary of the results to date of a program formulated to address the research and development of technologies and systems required to assess and reduce the impact of EMP on electric power systems. The technologies and systems being considered include simulation models, methods of assessment, definition of required experiments and data, development of protective hardware, and the creation or revision of operating and control procedures. Results to date include the development of relatively simple unclassified EMP environment models, the development of methods for extending EMP coupling models to the large transmission and distribution network associated with the electric power system, and the performance of a parametric study of HEMP induced surges using an appropriate EMP environment. An experiment to investigate the effect of corona on the coupling of EMP to conductors has been defined and has been performed in an EMP simulator. Experiments to determine the response of key components to simulated EMP surges and an investigation of the impact of steep-front, short-duration impulse on a selected number of the insulation systems used in electric power systems apparatus are being performed.

Electro-optic analysis of the influence of target geometry on electromagnetic pulses generated by petawatt laser-matter interactions

Science.gov (United States)

Robinson, Timothy; Giltrap, Samuel; Eardley, Samuel; Consoli, Fabrizio; De Angelis, Riccardo; Ingenito, Francesco; Stuart, Nicholas; Verona, Claudio; Smith, Roland A.

2018-01-01

We present an analysis of strong laser-driven electromagnetic pulses using novel electro-optic diagnostic techniques. A range of targets were considered, including thin plastic foils (20-550 nm) and mass-limited, optically-levitated micro-targets. Results from foils indicate a dependence of EMP on target thickness, with larger peak electric fields observed with thinner targets. Spectral analysis suggests high repeatability between shots, with identified spectral features consistently detected with earth following ejection of hot electrons from the plasma, in contrast to predictions for pin-mounted foils in the Poyé EMP generation model. With levitated targets, no EMP was measurable above the noise threshold of any diagnostic, despite observation of protons accelerated to >30 MeV energies, suggesting the discharge current contribution to EMP is dominant.

Final report for EMP instrumentation project DNA IACRO 75-815: magnetic thin film sensors

International Nuclear Information System (INIS)

Hsieh, E.J.; Miller, D.E.; Vindelov, K.E.; Brown, T.G.

1975-01-01

The magnetic thin film current sensor/recorder is a passive device which responds to the peak current and pulse shape of a transient event. The transient current information becomes a permanent record on the film. The thin film device is small, low mass and reusable. It has been proven to be fast (less than 1/2 nanosecond response), radiation hard and applicable to peak current measurement of both CW and pulsed signals. The sensors were initially developed at LLL for pulse-energy measurement on exploding wires. Later the Defense Nuclear Agency sponsored the present project to develop the magnetic thin film devices as EMP diagnostic tools. The Air Force Weapons Lab supported the work to test the field capabilities of the thin film devices at ARES test facility, Kirtland AFB. Sandia Lab is now using a new version of the thin film sensors to monitor the transient current induced by intense radiation in their hybrid microcircuits. Also, a field test has been planned with Naval Electronics Laboratory Center where the thin film sensors are to be used to measure peak CW current caused by rf radiation. Research results are summarized

Simulation methods of nuclear electromagnetic pulse effects in integrated circuits

International Nuclear Information System (INIS)

Cheng Jili; Liu Yuan; En Yunfei; Fang Wenxiao; Wei Aixiang; Yang Yuanzhen

2013-01-01

In the paper the ways to compute the response of transmission line (TL) illuminated by electromagnetic pulse (EMP) were introduced firstly, which include finite-difference time-domain (FDTD) and trans-mission line matrix (TLM); then the feasibility of electromagnetic topology (EMT) in ICs nuclear electromagnetic pulse (NEMP) effect simulation was discussed; in the end, combined with the methods computing the response of TL, a new method of simulate the transmission line in IC illuminated by NEMP was put forward. (authors)

EMP Threats to US National Security: Congressional Responses

Science.gov (United States)

Huessy, Peter

2011-04-01

The US Congress is considering how best to respond to concerns that EMP is a real and present danger to US security. The threats come from a variety of areas: solar storms, non-nuclear EMP from man-made machines and devices; and nuclear EMP from a nuclear device exploded above CONUS or other critical areas important to the United States and its allies. Responses have to date included passage in the House of legislation to protect the electrical grid in the United States from such threats and hearings before the Homeland Security Committee. Additional efforts include examining missile defense responses, protection of the maritime domain, and hardening of US military and related civilian infrastructure. The House of Representatives has also examined what Europe, the European Union and NATO, both government and private industry, have done in these areas. Complicating matters are related issues of cyber-security and overall homeland security priorities.

Nuclear EMP simulation for large-scale urban environments. FDTD for electrically large problems.

Energy Technology Data Exchange (ETDEWEB)

Smith, William S. [Los Alamos National Laboratory; Bull, Jeffrey S. [Los Alamos National Laboratory; Wilcox, Trevor [Los Alamos National Laboratory; Bos, Randall J. [Los Alamos National Laboratory; Shao, Xuan-Min [Los Alamos National Laboratory; Goorley, John T. [Los Alamos National Laboratory; Costigan, Keeley R. [Los Alamos National Laboratory

2012-08-13

In case of a terrorist nuclear attack in a metropolitan area, EMP measurement could provide: (1) a prompt confirmation of the nature of the explosion (chemical or nuclear) for emergency response; and (2) and characterization parameters of the device (reaction history, yield) for technical forensics. However, urban environment could affect the fidelity of the prompt EMP measurement (as well as all other types of prompt measurement): (1) Nuclear EMP wavefront would no longer be coherent, due to incoherent production, attenuation, and propagation of gamma and electrons; and (2) EMP propagation from source region outward would undergo complicated transmission, reflection, and diffraction processes. EMP simulation for electrically-large urban environment: (1) Coupled MCNP/FDTD (Finite-difference time domain Maxwell solver) approach; and (2) FDTD tends to be limited to problems that are not 'too' large compared to the wavelengths of interest because of numerical dispersion and anisotropy. We use a higher-order low-dispersion, isotropic FDTD algorithm for EMP propagation.

A survey of pulse shape options for a revised plastic ablator ignition design

Energy Technology Data Exchange (ETDEWEB)

Clark, D. S.; Milovich, J. L.; Hinkel, D. E.; Salmonson, J. D.; Peterson, J. L.; Berzak Hopkins, L. F.; Eder, D. C.; Haan, S. W.; Jones, O. S.; Marinak, M. M.; Robey, H. F.; Smalyuk, V. A.; Weber, C. R. [Lawrence Livermore National Laboratory Livermore, California 94550 (United States)

2014-11-15

Recent experimental results using the “high foot” pulse shape for inertial confinement fusion ignition experiments on the National Ignition Facility (NIF) [Moses et al., Phys. Plasmas 16, 041006 (2009)] have shown encouraging progress compared to earlier “low foot” experiments. These results strongly suggest that controlling ablation front instability growth can significantly improve implosion performance even in the presence of persistent, large, low-mode distortions. Simultaneously, hydrodynamic growth radiography experiments have confirmed that ablation front instability growth is being modeled fairly well in NIF experiments. It is timely then to combine these two results and ask how current ignition pulse shapes could be modified to improve one-dimensional implosion performance while maintaining the stability properties demonstrated with the high foot. This paper presents such a survey of pulse shapes intermediate between the low and high foot extremes in search of an intermediate foot optimum. Of the design space surveyed, it is found that a higher picket version of the low foot pulse shape shows the most promise for improved compression without loss of stability.

Time-domain modeling for shielding effectiveness of materials against electromagnetic pulse based on system identification

International Nuclear Information System (INIS)

Chen, Xiang; Chen, Yong Guang; Wei, Ming; Hu, Xiao Feng

2013-01-01

Shielding effectiveness (SE) of materials against electromagnetic pulse (EMP) cannot be well estimated by traditional test method of SE of materials which only consider the amplitude-frequency characteristic of materials, but ignore the phase-frequency ones. In order to solve this problem, the model of SE of materials against EMP was established based on system identification (SI) method with time-domain linear cosine frequency sweep signal. The feasibility of the method in this paper was examined depending on infinite planar material and the simulation research of coaxial test method and windowed semi-anechoic box of materials. The results show that the amplitude-frequency and phase-frequency information of each frequency can be fully extracted with this method. SE of materials against strong EMP can be evaluated with time-domain low field strength (voltage) of cosine frequency sweep signal. And SE of materials against a variety EMP will be predicted by the model.

A cross-country Exchange Market Pressure (EMP dataset

Directory of Open Access Journals (Sweden)

Mohit Desai

2017-06-01

Full Text Available The data presented in this article are related to the research article titled - “An exchange market pressure measure for cross country analysis” (Patnaik et al. [1]. In this article, we present the dataset for Exchange Market Pressure values (EMP for 139 countries along with their conversion factors, ρ (rho. Exchange Market Pressure, expressed in percentage change in exchange rate, measures the change in exchange rate that would have taken place had the central bank not intervened. The conversion factor ρ can interpreted as the change in exchange rate associated with $1 billion of intervention. Estimates of conversion factor ρ allow us to calculate a monthly time series of EMP for 139 countries. Additionally, the dataset contains the 68% confidence interval (high and low values for the point estimates of ρ’s. Using the standard errors of estimates of ρ’s, we obtain one sigma intervals around mean estimates of EMP values. These values are also reported in the dataset.

A cross-country Exchange Market Pressure (EMP) dataset.

Science.gov (United States)

Desai, Mohit; Patnaik, Ila; Felman, Joshua; Shah, Ajay

2017-06-01

The data presented in this article are related to the research article titled - "An exchange market pressure measure for cross country analysis" (Patnaik et al. [1]). In this article, we present the dataset for Exchange Market Pressure values (EMP) for 139 countries along with their conversion factors, ρ (rho). Exchange Market Pressure, expressed in percentage change in exchange rate, measures the change in exchange rate that would have taken place had the central bank not intervened. The conversion factor ρ can interpreted as the change in exchange rate associated with $1 billion of intervention. Estimates of conversion factor ρ allow us to calculate a monthly time series of EMP for 139 countries. Additionally, the dataset contains the 68% confidence interval (high and low values) for the point estimates of ρ 's. Using the standard errors of estimates of ρ 's, we obtain one sigma intervals around mean estimates of EMP values. These values are also reported in the dataset.

[Effect of electromagnetic pulse irradiation on structure and function of Leydig cells in mice].

Science.gov (United States)

Wang, Shui-Ming; Wang, De-Wen; Peng, Rui-Yun; Gao, Ya-Bing; Yang, Yi; Hu, Wen-Hua; Chen, Hao-Yu; Zhang, You-Ren; Gao, Yan

2003-08-01

To explore the effect of electromagnetic pulse (EMP) irradiation on structure and function of Leydig cells in mice. One hundred and fourteen male Kunming mice were randomly divided into irradiated and control group, the former radiated generally by 8 x 10(3) V/m, 2 x 10(4) V/m and 6 x 10(4) V/m EMP respectively five times within two minutes. Pathological changes of Leydig cells were observed by light and electron microscope. Serum testosterone (T), luteinizing hormone (LH) and estradiol (E2) were measured dynamically by radioimmunoassay at 6 h, 1 d, 3 d, 7 d, 14 d and 28 d after irradiation. Main pathological changes were edema and vacuolation, swelling of cytoplasmic mitochondria, reduce of lipid droplets, pale staining of most of lipid droplets, and partial or complete cavitation of lipid droplets in Leydig cells within 28 days after EMP radiation. Compared with normal controls, serum T decreased in all in different degrees within 28 days, and dropped significantly at 6 h-14 d, 6 h-7 d and 1 d-28 d after 8 x 10(3) V/m, 2 x 10(4) V/m and 6 x 10(4) V/m EMP irradiation(P < 0.05 or P < 0.01). EMP irradiation caused no significant changes in serum LH and E2. Leydig cells are among those that are the most susceptible to EMP irradiation. EMP irradiation may cause significant injury in structure and function of Leydig cells in mice, whose earlier and continuous effect is bound to affect sexual function and sperm production.

Promoter Hypermethylation of the EMP3 Gene in a Series of 229 Human Gliomas

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Marta Mellai

2013-01-01

Full Text Available The epithelial membrane protein 3 (EMP3 is a candidate tumor suppressor gene in the critical region 19q13.3 for several solid tumors, including tumors of the nervous systems. The aim of this study was to investigate the EMP3 promoter hypermethylation status in a series of 229 astrocytic and oligodendroglial tumors and in 16 GBM cell lines. The analysis was performed by methylation-specific PCR and capillary electrophoresis. Furthermore, the EMP3 expression at protein level was evaluated by immunohistochemistry and Western blotting analysis. Associations of EMP3 hypermethylation with total 1p/19q codeletion, MGMT promoter hypermethylation, IDH1/IDH2 and TP53 mutations, and EGFR amplification were studied, as well as its prognostic significance. The EMP3 promoter hypermethylation has been found in 39.5% of gliomas. It prevailed in low-grade tumors, especially in gliomas with an oligodendroglial component, and in sGBMs upon pGBMs. In oligodendroglial tumors, it was strongly associated with both IDH1/IDH2 mutations and total 1p/19q codeletion and inversely with EGFR gene amplification. No association was found with MGMT hypermethylation and TP53 mutations. In the whole series, the EMP3 hypermethylation status correlated with 19q13.3 loss and lack of EMP3 expression at protein level. A favorable prognostic significance on overall survival of the EMP3 promoter hypermethylation was found in patients with oligodendroglial tumors.

sae is essential for expression of the staphylococcal adhesins Eap and Emp.

Science.gov (United States)

Harraghy, Niamh; Kormanec, Jan; Wolz, Christiane; Homerova, Dagmar; Goerke, Christiane; Ohlsen, Knut; Qazi, Saara; Hill, Philip; Herrmann, Mathias

2005-06-01

Eap and Emp are two Staphylococcus aureus adhesins initially described as extracellular matrix binding proteins. Eap has since emerged as being important in adherence to and invasion of eukaryotic cells, as well as being described as an immunomodulator and virulence factor in chronic infections. This paper describes the mapping of the transcription start point of the eap and emp promoters. Moreover, using reporter-gene assays and real-time PCR in defined regulatory mutants, environmental conditions and global regulators affecting expression of eap and emp were investigated. Marked differences were found in expression of eap and emp between strain Newman and the 8325 derivatives SH1000 and 8325-4. Moreover, both genes were repressed in the presence of glucose. Analysis of expression of both genes in various regulatory mutants revealed that sarA and agr were involved in their regulation, but the data suggested that there were additional regulators of both genes. In a sae mutant, expression of both genes was severely repressed. sae expression was also reduced in the presence of glucose, suggesting that repression of eap and emp in glucose-containing medium may, in part, be a consequence of a decrease in expression of sae.

Análisis semiótico en secuencias de interacción empáticas y no empáticas: un estudio microgenético

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Pablo Fossa

Full Text Available Resumen Este estudio tuvo por objetivo explorar y describir el proceso de regulación dialógica en interacciones conversacionales. Se registraron en video treinta díadas de estudiantes desconocidos entre sí en interacciones que tuvieron una manipulación orientada a generar una situación empática o bien no-empática. Se seleccionaron cuatro segmentos de conversación, dos por cada tipo de interacción. El texto fue analizado con un protocolo de análisis semiótico basado en el modelo de análisis propuesto por (Molina, 2007. Los resultados muestran que las interacciones empáticas se caracterizan por un proceso de coconstrucción de significados, con una adecuada administración de la tensión y una identificación con el signo lingüístico. Por otra parte, las interacciones no empáticas se caracterizan por la emergencia de signos lingüísticos que no continúan la secuencia de construcción de significados; con una alta tensión dialógica, y una estrategia de distanciamiento o abandono del campo de significado.

Taking in account the electromagnetic pulses in study of a material or system

International Nuclear Information System (INIS)

Jeannolle, J.

1985-01-01

High altitude nuclear bursts generate extremely short and large magnitude electromagnetic pulses (EMP). Electronic circuits which are commonly used nowadays are directly threatened by such an effect. This effect is so important that it has the characteristic to cover large areas, as large as a whole country. For an equipment or a system to stand against such an electromagnetic threat without being considerably disturbed, it is advised to take into account particular protections from the outset of the design phase and during the production phase, that is to say to ensure its hardening. Taking into account and ensuring the EMP protection of an equipment or a system, the Telecommunications Division (DTC) of Thomson-CSF has been devoting to for a number of years. The experience acquired through various studies and production work has allowed a thorough definition of the main steps required in an EMP hardening task: - hardening goal definition; - hardening study and design; - hardening carrying out; - design and production of EMP environment simulators; - hardening validation; - maintenance. This paper describes for each one of these steps: - which approach is undertaken; - which questions are raised; - which documents to constitute [fr

Emp is a component of the nuclear matrix of mammalian cells and undergoes dynamic rearrangements during cell division

International Nuclear Information System (INIS)

Bala, Shashi; Kumar, Ajay; Soni, Shivani; Sinha, Sudha; Hanspal, Manjit

2006-01-01

Emp, originally detected in erythroblastic islands, is expressed in numerous cell types and tissues suggesting a functionality not limited to hematopoiesis. To study the function of Emp in non-hematopoietic cells, an epitope-tagged recombinant human Emp was expressed in HEK cells. Preliminary studies revealed that Emp partitioned into both the nuclear and Triton X-100-insoluble cytoskeletal fractions in approximately a 4:1 ratio. In this study, we report investigations of Emp in the nucleus. Sequential extractions of interphase nuclei showed that recombinant Emp was present predominantly in the nuclear matrix. Immunofluorescence microscopy showed that Emp was present in typical nuclear speckles enriched with the spliceosome assembly factor SC35 and partially co-localized with actin staining. Coimmunoprecipitation and GST-pull-down assays confirmed the apparent close association of Emp with nuclear actin. During mitosis, Emp was detected at the mitotic spindle/spindle poles, as well as in the contractile ring during cytokinesis. These results suggest that Emp undergoes dynamic rearrangements within the nuclear architecture that are correlated with cell division

Gel shift analysis of the empA promoter region in Vibrio anguillarum

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Denkin Steven M

2004-10-01

Full Text Available Abstract Background The induction of metalloprotease encoded by empA in Vibrio anguillarum occurs at high cell density in salmon intestinal mucus. Previously we have shown that there are significant differences in empA expression in two strains of V. anguillarum, M93Sm and NB10. It is hypothesized that differences in empA regulation are due to differences in binding of regulatory elements. Results Two strains of V. anguillarum, M93Sm and NB10, were examined and compared for the presence of DNA regulatory proteins that bind to and control the empA promoter region. Gel mobility shift assays, using a digoxigenin (DIG-labeled oligomer containing a lux box-like element and the promoter for empA, were done to demonstrate the presence of a DNA-binding protein. Protein extracts from NB10 cells incubated in Luria Bertani broth + 2% NaCl (LB20, nine salts solution + 200 μg/ml mucus (NSSM, 3M (marine minimal medium, or NSS resulted in a gel mobility shift. No gel mobility shift was seen when protein extracts from either LB20- or NSSM-grown M93Sm cells were mixed with the DIG-labeled empA oligomer. The azocasein assay detected protease activity in all incubation conditions for NB10 culture supernatants. In contrast, protease activity was detected in M93Sm culture supernatants only when incubated in NSSM. Since the luxR homologue in V. anguillarum, vanT, has been cloned, sequenced, and shown to be required for protease activity, we wanted to determine if vanT mutants of NB10 exhibit the same gel shift observed in the wild-type. Site-directed mutagenesis was used to create vanT mutants in V. anguillarum M93Sm and NB10 to test whether VanT is involved with the gel mobility shift. Both vanT mutants, M02 and NB02, did not produce protease activity in any conditions. However, protein extracts from NB02 incubated in each condition still exhibited a gel shift when mixed with the DIG-labeled empA oligomer. Conclusions The data demonstrate that protein extracts of V

Radiation effects of electromagnetic pulses on mouse blood-testis barrier

International Nuclear Information System (INIS)

Hou Wugang; Zhao Jie; Zhang Yuanqiang

2005-01-01

Radiation effects caused by 100 kV/m and 400 kV/m electromagnetic pulse (EMP) irradiations on mouse blood-testis barrier were studied by means of routine HE staining, Lanthanum traced electron microscope and injection of caudal vein with Evans Blue. The EMP irradiation of different dose rates damaged Sertoli's cell and blood-testis barrier of mouse testis in different levels. Severe injuries were observed with the 400 kV/m irradiation group, with apoptosis and necrosis in a large quantity of the spermatogenic cells, shape and structural changes of the Sertoli's cells, and serious injuries to the blood-testis barrier, one day after the irradiation. The basal compartment separated from the adluminal compartment in most of the VIII stage seminiferous epithelium, and a great number of apoptosis and necrosis spermatogenic cells were released into the cavities. Injuries of blood-testis barrier could be observed 21 days after the 400 kV/m irradiation. The injuries of 100 kV/m irradiation groups were less severe than the 400 kV/m groups, in which the damages to the Sertoli's cells, the seminiferous epithelium and blood-testis barrier recovered to some extent 14 days after the irradiation. The authors conclude that EMP irradiation can damage mouse blood-tests barrier. The injuries, and the time for recovery, are related to EMP power intensity. (authors)

Mesothelioma and other lung disease in taconite miners; the uncertain role of non-asbestiform EMP.

Science.gov (United States)

Mandel, Jeffrey H; Odo, Nnaemeka U

2018-04-10

The purpose of this paper was to assess the role of non-asbestiform amphibole EMPs in the etiology of mesotheliomas and other lung disease in taconite (iron ore) miners. Increased mesothelioma rates have been described in Minnesota taconite workers since the late 1990s. Currently, over 100 cases have been reported by the Minnesota Department of Health within the complete cohort of miners in Minnesota. Geologic sampling has indicated that only the eastern part of the iron range contains non-asbestiform amphibole elongate mineral particles (EMPs), in close proximity to the ore. This type of EMP has been less studied and also exists in talc and gold mining. A series of investigations into the state's taconite industry have been recently completed. Results from a cohort mortality study indicated an SMR of 2.77 (95% CI = 1.87-3.96) for mesothelioma. In a case-control study, the odds ratio for mesothelioma for high vs. low EMP exposure was 2.25 (5% CI = 1.13-4.5) but EMPs in this study were counted by phase contrast microscopy. Odds ratios were not elevated in mines located in the eastern part of the Mesabi iron range. The overall findings suggest that mesothelioma in taconite miners is related to EMP exposure. Because of the way EMPs were counted, results from these studies cannot allow a firm conclusion about the association between EMP exposure and the reported excess mesothelioma. Copyright © 2018 Elsevier Inc. All rights reserved.

Kemasan Menarik dan Internet Marketing untuk Meningkatkan Nilai Jual Emping Garut sebagai Produk Unggulan Kabupaten Sragen

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Sari Purnavita

2018-03-01

Full Text Available Tanaman garut termasuk dalam jenis umbi-umbian yang banyak ditanam oleh masyarakat yang tinggal di Kecamatan Gesi, Kabupaten Sragen. Di Kabupaten Sragen terdapat beberapa industri rumah tangga emping garut, dua di antaranya yang memiliki motivasi sangat besar untuk berkembang adalah UKM emping garut “Sumber Rejeki” dan UKM emping garut “Fadilah”. Permasalahan kedua UKM adalah keterbatasan inovasi rasa emping garut, kemasan sangat sederhana, dan sistem pemasaran masih tradisional sehingga sehingga omzet penjualan dan nilai jual produk masih rendah. Untuk meningkatkan omzet penjualan dapat dilakukan dengan perbaikan inovasi dan teknologi pengemasan, teknologi seasoning dengan bumbu tabur, dan memperluas pemasaran dengan media internet. Produk emping garut yang dikemas secara menarik, inovasi produk emping garut aneka rasa, dan pemasaran dengan media internet melalui blogspot dapat menenbus pemasaran secara luas baik di toko-toko besar, harga jual produk meningkat 50%,dan omzet penjualan meningkat 100%.

Down-regulation of EMP1 is associated with epithelial hyperplasia and metaplasia in nasal polyps.

Science.gov (United States)

Yu, Xue Min; Li, Chun Wei; Li, Ying Ying; Liu, Jing; Lin, Zhi Bin; Li, Tian Ying; Zhao, Li; Pan, Xin Liang; Shi, Li; Wang, De Yun

2013-11-01

The aim of this study was to assess protein and mRNA expression of epithelial membrane protein 1 (EMP1) in the nasal mucosa of patients with nasal polyps (NP), and to determine what changes occur in response to glucocorticosteroid (GC) treatment. NP tissue was obtained from 55 patients, 18 of whom were treated with nasal GCs (i.e. these 18 patients had NP biopsies taken before and after treatment). Biopsies of inferior turbinate mucosa from 30 healthy subjects were used as controls. Quantitative PCR and immunohistochemistry were performed to determine the expression levels of EMP1. EMP1 mRNA expression was significantly lower (2.77-fold) in tissues from NP patients before GC treatment when compared to controls, but was increased in these patients after GC treatment. EMP1 staining in nasal epithelium co-localized with both basal (p63(+)) and differentiated (CK18(+)) epithelial cells. Their immunoreactivity was significantly greater in controls than NP patients. EMP1 mRNA levels were lower in the epithelium with severe hyperplasia (1.79-fold) or with metaplasia (1.85-fold) as compared to those with mild to moderate hyperplasia or non-metaplastic epithelium, respectively. Positive correlations between EMP1 and other epithelial cell-related gene (e.g. JUN, PTGS2, AREG etc.) mRNAs were observed. EMP1 could be a biomarker for aberrant epithelial remodelling and metaplasia in chronic inflammatory upper airway mucosa (e.g. NP). © 2013 John Wiley & Sons Ltd.

Exponential Megapriming PCR (EMP) Cloning—Seamless DNA Insertion into Any Target Plasmid without Sequence Constraints

Science.gov (United States)

Ulrich, Alexander; Andersen, Kasper R.; Schwartz, Thomas U.

2012-01-01

We present a fast, reliable and inexpensive restriction-free cloning method for seamless DNA insertion into any plasmid without sequence limitation. Exponential megapriming PCR (EMP) cloning requires two consecutive PCR steps and can be carried out in one day. We show that EMP cloning has a higher efficiency than restriction-free (RF) cloning, especially for long inserts above 2.5 kb. EMP further enables simultaneous cloning of multiple inserts. PMID:23300917

A compra de votos: uma aproximação empírica

Directory of Open Access Journals (Sweden)

Bruno Wilhelm Speck

2003-05-01

Full Text Available O artigo aborda o fenômeno da compra de votos no contexto histórico e apresenta dados de um levantamento empírico realizado através de uma pesquisa de opinião após as eleições municipais no Brasil no ano 2000. São discutidas questões relacionadas ao significado da compra de votos no conjunto das questões ligadas à lisura do processo eleitoral. O texto aborda também os problemas enfrentados na pesquisa em função do assunto abordado e soluções metodológicas encontradas.The author presents the results of a national survey on vote buying during the local elections in Braszil in 2000. In his analysis he places vote buying into the broader historical perspective of electoral and other forms of manipulation and corruption. Specific methodological questions of surveys on such critical questions like fraude and corruption are discussed

Exponential megapriming PCR (EMP cloning--seamless DNA insertion into any target plasmid without sequence constraints.

Directory of Open Access Journals (Sweden)

Alexander Ulrich

Full Text Available We present a fast, reliable and inexpensive restriction-free cloning method for seamless DNA insertion into any plasmid without sequence limitation. Exponential megapriming PCR (EMP cloning requires two consecutive PCR steps and can be carried out in one day. We show that EMP cloning has a higher efficiency than restriction-free (RF cloning, especially for long inserts above 2.5 kb. EMP further enables simultaneous cloning of multiple inserts.

Measures to protect communication systems from EMP effects

International Nuclear Information System (INIS)

Stadler, B.

1977-01-01

Possible EMP damage in transmitter and receiver elements, including antennas, is dealt with. It is recommendet that these important systems should be installed inside a commercially available Faraday cage for do-it-yourself assembly. (HP) [de

A Survey of Graduates of Combined Emergency Medicine-Pediatrics Residency Programs: An Update.

Science.gov (United States)

Strobel, Ashley M; Chasm, Rose M; Woolridge, Dale P

2016-10-01

In 1998, emergency medicine-pediatrics (EM-PEDS) graduates were no longer eligible for the pediatric emergency medicine (PEM) sub-board certification examination. There is a paucity of guidance regarding the various training options for medical students who are interested in PEM. We sought to to determine attitudes and personal satisfaction of graduates from EM-PEDS combined training programs. We surveyed 71 graduates from three EM-PEDS residences in the United States. All respondents consider their combined training to be an asset when seeking a job, 92% find it to be an asset to their career, and 88% think it provided added flexibility to job searches. The most commonly reported shortcoming was their ineligibility for the PEM sub-board certification. The lack of this designation was perceived to be a detriment to securing academic positions in dedicated children's hospitals. When surveyed regarding which training offers the better skill set for the practice of PEM, 90% (44/49) stated combined EM-PEDS training. When asked which training track gives them the better professional advancement in PEM, 52% (23/44) chose combined EM-PEDS residency, 27% (12/44) chose a pediatrics residency followed by a PEM fellowship, and 25% (11/44) chose an EM residency then a PEM fellowship. No EM-PEDS respondents considered PEM fellowship training after the completion of the dual training program. EM-PEDS graduates found combined training to be an asset in their career. They felt that it provided flexibility in job searches, and that it was ideal training for the skill set required for the practice of PEM. EM-PEDS graduates' practices varied, including mixed settings, free-standing children's hospitals, and community emergency departments. Copyright © 2016 Elsevier Inc. All rights reserved.

Long-term electromagnetic pulse exposure induces Abeta deposition and cognitive dysfunction through oxidative stress and overexpression of APP and BACE1.

Science.gov (United States)

Jiang, Da-Peng; Li, Jin-Hui; Zhang, Jie; Xu, Sheng-Long; Kuang, Fang; Lang, Hai-Yang; Wang, Ya-Feng; An, Guang-Zhou; Li, Jing; Guo, Guo-Zhen

2016-07-01

A progressively expanded literature has been devoted in the past years to the noxious or beneficial effects of electromagnetic field (EMF) to Alzheimer׳s disease (AD). This study concerns the relationship between electromagnetic pulse (EMP) exposure and the occurrence of AD in rats and the underlying mechanisms, focusing on the role of oxidative stress (OS). 55 healthy male Sprague Dawley (SD) rats were used and received continuous exposure for 8 months. Morris water maze (MWM) test was conducted to test the ability of cognitive and memory. The level of OS was detected by superoxide dismutase (SOD) activity and glutathione (GSH) content. We found that long-term EMP exposure induced cognitive damage in rats. The content of β-amyloid (Aβ) protein in hippocampus was increased after long-term EMP exposure. OS of hippocampal neuron was detected. Western blotting and immunohistochemistry (IHC) assay showed that the content of Aβ protein and its oligomers in EMP-exposed rats were higher than that of sham-exposed rats. The content of Beta Site App Cleaving Enzyme (BACE1) and microtubule-associated protein 1 light chain 3-II (LC3-II) in EMP-exposed rats hippocampus were also higher than that of sham-exposed rats. SOD activity and GSH content in EMP-exposed rats were lower than sham-exposed rats (p<0.05). Several mechanisms were proposed based on EMP exposure-induced OS, including increased amyloid precursor protein (APP) aberrant cleavage. Although further study is needed, the present results suggest that long-term EMP exposure is harmful to cognitive ability in rats and could induce AD-like pathological manifestation. Copyright © 2016 Elsevier B.V. All rights reserved.

Interface Control Document for the EMPACT Module that Estimates Electric Power Transmission System Response to EMP-Caused Damage

Energy Technology Data Exchange (ETDEWEB)

Werley, Kenneth Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mccown, Andrew William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)ory

2016-06-26

The EPREP code is designed to evaluate the effects of an Electro-Magnetic Pulse (EMP) on the electric power transmission system. The EPREP code embodies an umbrella framework that allows a user to set up analysis conditions and to examine analysis results. The code links to three major physics/engineering modules. The first module describes the EM wave in space and time. The second module evaluates the damage caused by the wave on specific electric power (EP) transmission system components. The third module evaluates the consequence of the damaged network on its (reduced) ability to provide electric power to meet demand. This third module is the focus of the present paper. The EMPACT code serves as the third module. The EMPACT name denotes EMP effects on Alternating Current Transmission systems. The EMPACT algorithms compute electric power transmission network flow solutions under severely damaged network conditions. Initial solutions are often characterized by unacceptible network conditions including line overloads and bad voltages. The EMPACT code contains algorithms to adjust optimally network parameters to eliminate network problems while minimizing outages. System adjustments include automatically adjusting control equipment (generator V control, variable transformers, and variable shunts), as well as non-automatic control of generator power settings and minimal load shedding. The goal is to evaluate the minimal loss of customer load under equilibrium (steady-state) conditions during peak demand.

Empowerment impact assessment (EmpIA), a tool for poverty alleviation and capacity building

CSIR Research Space (South Africa)

Louw, MR

2006-09-01

Full Text Available their quality of life. xrhombus Facilitate the upgrading of the social and physical environment. xrhombus Increase employment. xrhombus Reduce poverty. xrhombus Stimulate economic growth. xrhombus Reduce imbalances in access to economic opportunities. 1... IMPACT ASSESSMENT (EmpIA), A TOOL FOR POVERTY ALLEVIATION AND CAPACITY BUILDING M.R. LOUW CSIR Built Environment: Pretoria, P.O. Box 395, Pretoria, 0001 ABSTRACT Empowerment impact assessment (EmpIA) is a quantitative...

Influence of electromagnetic pulse on the offspring sex ratio of male BALB/c mice.

Science.gov (United States)

Li, Jin-Hui; Jiang, Da-Peng; Wang, Ya-Feng; Yan, Jia-Jia; Guo, Qi-Yan; Miao, Xia; Lang, Hai-Yang; Xu, Sheng-Long; Liu, Jun-Ye; Guo, Guo-Zhen

2017-09-01

Public concern is growing about the exposure to electromagnetic fields (EMF) and its effect on male reproductive health. Detrimental effect of EMF exposure on sex hormones, reproductive performance and sex-ratio was reported. The present study was designed to clarify whether paternal exposure to electromagnetic pulse (EMP) affects offspring sex ratio in mice. 50 male BALB/c mice aged 5-6 weeks were exposed to EMP daily for 2 weeks before mated with non-exposed females at 0d, 7d, 14d, 21d and 28d after exposure. Sex hormones including total testosterone, LH, FSH, and GnRH were detected using radioimmunoassay. The sex ratio was examined by PCR and agarose gel electrophoresis. The results of D0, D21 and D28 showed significant increases compared with sham-exposed groups. The serum testosterone increased significantly in D0, D14, D21, and D28 compared with sham-exposed groups (p<0.05). Overall, this study suggested that EMP exposure may lead to the disturbance of reproductive hormone levels and affect the offspring sex ratio. Copyright © 2017. Published by Elsevier B.V.

Probabilistic approach to EMP assessment

International Nuclear Information System (INIS)

Bevensee, R.M.; Cabayan, H.S.; Deadrick, F.J.; Martin, L.C.; Mensing, R.W.

1980-09-01

The development of nuclear EMP hardness requirements must account for uncertainties in the environment, in interaction and coupling, and in the susceptibility of subsystems and components. Typical uncertainties of the last two kinds are briefly summarized, and an assessment methodology is outlined, based on a probabilistic approach that encompasses the basic concepts of reliability. It is suggested that statements of survivability be made compatible with system reliability. Validation of the approach taken for simple antenna/circuit systems is performed with experiments and calculations that involve a Transient Electromagnetic Range, numerical antenna modeling, separate device failure data, and a failure analysis computer program

A method for visualizing surface-exposed and internal PfEMP1 adhesion antigens in Plasmodium falciparum infected erythrocytes

Directory of Open Access Journals (Sweden)

Arnot David E

2008-06-01

Full Text Available Abstract Background The insertion of parasite antigens into the host erythrocyte membrane and the structure and distribution of Plasmodium falciparum adhesion receptors on that membrane are poorly understood. Laser scanning confocal microscopy (LSCM and a novel labelling and fixation method have been used to obtain high resolution immuno-fluorescent images of erythrocyte surface PfEMP1 and internal antigens which allow analysis of the accumulation of PfEMP1 on the erythrocyte membrane during asexual development. Methods A novel staining technique has been developed which permits distinction between erythrocyte surface PfEMP1 and intracellular PfEMP1, in parasites whose nuclear material is exceptionally well resolved. Primary antibody detection by fluorescence is carried out on the live parasitized erythrocyte. The surface labelled cells are then fixed using paraformaldehyde and permeabilized with a non-ionic detergent to permit access of antibodies to internal parasite antigens. Differentiation between surface and internal antigens is achieved using antibodies labelled with different fluorochromes and confocal microscopy Results Surface exposed PfEMP1 is first detectable by antibodies at the trophozoite stage of intracellular parasite development although the improved detection method indicates that there are differences between different laboratory isolates in the kinetics of accumulation of surface-exposed PfEMP1. Conclusion A sensitive method for labelling surface and internal PfEMP1 with up to three different fluorochromes has been developed for laser scanning confocal optical microscopy and the analysis of the developmental expression of malaria adhesion antigens.

Transistor collector breakdown in the presence of conducted EMP and gamma radiation

International Nuclear Information System (INIS)

Rice, D.H.

1975-01-01

In this paper we develop expressions which describe breakdown, negative resistance and latch characteristics for a common emitter transistor when exposed to simultaneous conducted EMP and ionizing radiation. These expressions are derived from a modified Ebers-Moll model and show that common emitter breakdown voltage is reduced, latch (or sustaining voltage) remains unchanged, and that the negative resistance characteristics are changed. Using the modified Ebers-Moll model good agreement between predicted and observed circuit response is demonstrated when the circuits are exposed to a rising collector voltage (due to EMP) and simultaneous ionizing (gamma) radiation

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

International Nuclear Information System (INIS)

Cheng Xiaolei; Liu Fang; Ouyang Xiaoping

2012-01-01

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

Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

Energy Technology Data Exchange (ETDEWEB)

Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

1983-02-01

This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants.

Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

International Nuclear Information System (INIS)

Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

1983-02-01

This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants

The expression of Smad4 after radiation of electromagnetic pulses and apoptosis in spermatogenic cells in mouse

International Nuclear Information System (INIS)

Ji Xinxin; Hou Wugang; Zhao Jie; Zhao Yong; Li Wei; Zhang Yuanqiang

2007-01-01

The aim of the study was to investigate the relationships between apoptosis induced by radiation of electromagnetic pulses (EMP) and the expression of Smad4 in mouse spermatogenic cells. 40 adult Balb/c mice were used, and 20 were irradiated with whole-body 400kV/m EMP. The mice were sacrificed and specimens were harvested at 1, 7, 14, 21 and 28 days after the irradiation. Histological changes were observed through Hematoxylin-Eosin staining (H-E staining), the apoptosis of spermatogenic cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling method (TUNEL method) and the Smad4 expression was observed using immunohistochemistry SABC methods. Severe injuries were observed 1 day after the radiation and seminiferous epithelium was mostly recovered 28d after the radiation. The localization of smad4 was significantly different in EMP group compared to the control group, and the expression densities of smad4 decreased significantly at 7, 14 and 21d after irradiation (p<0.05). TUNEL assays demonstrated that there was a significant increase in the mean apoptotic index (AI) in irradiation groups than that of control groups (p<0.01). The results suggested that Smad4 and TGF-13/Smad signal pathway might play an important role in spermatogenic cells apoptosis induced by radiation of EMP. (authors)

Analysis of the damage threshold of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

International Nuclear Information System (INIS)

Xi Xiao-Wen; Chai Chang-Chun; Liu Yang; Yang Yin-Tang; Fan Qing-Yang; Shi Chun-Lei

2016-01-01

An electromagnetic pulse (EMP)-induced damage model based on the internal damage mechanism of the GaAs pseudomorphic high electron mobility transistor (PHEMT) is established in this paper. With this model, the relationships among the damage power, damage energy, pulse width and signal amplitude are investigated. Simulation results show that the pulse width index from the damage power formula obtained here is higher than that from the empirical formula due to the hotspot transferring in the damage process of the device. It is observed that the damage energy is not a constant, which decreases with the signal amplitude increasing, and then changes little when the signal amplitude reaches up to a certain level. (paper)

The effects of electromagnetic pulse on the protein levels of tight junction associated-proteins in the cerebral cortex, hippocampus, heart, lung, and testis of rats.

Science.gov (United States)

Qiu, LianBo; Chen, Chen; Ding, GuiRong; Zhou, Yan; Zhang, MengYao

2011-08-01

To investigate changes in the expression of tight junction (TJ) proteins in the cerebral cortex, hippocampus, heart, lung, and testes of rats after exposure to electromagnetic pulse (EMP). Eighteen adult male Sprague-Dawley rats were divided into sham and exposure groups. The exposure groups received EMP at 200 kV/m for 200 pulses with a repetition rate of 1 Hz. The expression of TJ proteins (ZO-1, occludin, actin) in the several organs was examined by western blotting. ZO-1 levels in the cerebral cortex decreased 1 h and 3 h after EMP exposure compared with sham group (P<0.05). No significant difference was observed for occludin and actin. ZO-1 levels in the hippocampus increased 1 h and 3 h post-exposure (P<0.05), and occludin decreased after 3 h (P<0.05); however, actin was unaffected. ZO-1 levels in the heart increased 3 h post-exposure (P<0.05), occludin decreased 3 h post-exposure (P<0.05), and actin increased 1 h and 3 h post-exposure (P<0.05). ZO-1, occludin and actin levels in the lung decreased compared with those in the sham group (P<0.05). ZO-1 and occludin levels in the testes decreased 1 h and 3 h post-exposure (P<0.05), but actin showed no significant change. Exposure to EMP altered the expression levels of TJ proteins, particularly ZO-1, in the organs of adult male rats, which may induce changes in barrier structure and function. Copyright © 2011 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

Transparência e Replicabilidade na Pesquisa Empírica em Direito: conceitos e ferramentas

OpenAIRE

Oliveira, Paulo

2018-01-01

Com o crescimento das pesquisas empíricas em Direito quais as práticas devem ser adotadas pelos pesquisadores para acompanhar o Padrão Ouro da pesquisa? Quais os conceitos necessários para que a Pesquisa Empírica possa crescer de forma sustentável e democrática? Esse artigo tenta delinear alguns conceitos importantes da Ciência 2.0 e mostra algumas das principais ferramentas para atingir plenamente o ideal de Ciência Aberta.

Parallelized FDTD simulation for flat-plate bounded wave EMP simulator with lumped terminator

International Nuclear Information System (INIS)

Zhu Xiangqin; Chen Weiqing; Chen Zaigao; Cai Libing; Wang Jianguo

2013-01-01

A parallelized finite-difference time-domain(FDTD) method for simulating the bounded wave electromagnetic pulse (EMP) simulator with lumped terminator and parallel plate is presented. The effects of several model-parameters on the simulator to the fields in the working volume are simulated and analyzed. The results show that if the width of the lower PEC plate is(or is bigger than)1.5 times that of the upper plate of working volume, the projection length of front transitional section does not have a significant effect on the rise-times of electric fields at the points near the front transitional section, and the rise-times of electric fields at the points near the working volume center decrease as the projection length increases, but the decrement of rise-time decreases. The rise-times of E z at all points also decrease as the lower PEC plate's width increases, but the decrements of rise-time decreases. If the projection length of the front transitional section is fixed, the good results can not be obtained by increasing or decreasing the height of the simulator only, however, which has an optimal value. (authors)

47 CFR 215.1 - Background.

Science.gov (United States)

2010-10-01

... POINT FOR ELECTROMAGNETIC PULSE (EMP) INFORMATION § 215.1 Background. (a) The nuclear electromagnetic pulse (EMP) is part of the complex environment produced by nuclear explosions. It consists of transient...

47 CFR 215.0 - Purpose and authority.

Science.gov (United States)

2010-10-01

... POINT FOR ELECTROMAGNETIC PULSE (EMP) INFORMATION § 215.0 Purpose and authority. The purpose of this part is to designate a focal point within the Federal Government for electromagnetic pulse (EMP...

Abundance analysis of SDSS J134338.67+484426.6; an extremely metal-poor star from the MARVELS pre-survey

Science.gov (United States)

Susmitha Rani, A.; Sivarani, T.; Beers, T. C.; Fleming, S.; Mahadevan, S.; Ge, J.

2016-05-01

We present an elemental-abundance analysis of an extremely metal-poor (EMP; [Fe/H] <-3.0) star, SDSS J134338.67+484426.6, identified during the course of the Multi-object Apache Point Observatory Radial Velocity Exoplanet Large-area Survey spectroscopic pre-survey of some 20 000 stars to identify suitable candidates for exoplanet searches. This star, with an apparent magnitude V = 12.14, is the lowest metallicity star found in the pre-survey, and is one of only ˜20 known EMP stars that are this bright or brighter. Our high-resolution spectroscopic analysis shows that this star is a subgiant with [Fe/H] = -3.42, having `normal' carbon and no enhancement of neutron-capture abundances. Strontium is underabundant, [Sr/Fe] = -0.47, but the derived lower limit on [Sr/Ba] indicates that Sr is likely enhanced relative to Ba. This star belongs to the sparsely populated class of α-poor EMP stars that exhibit low ratios of [Mg/Fe], [Si/Fe], and [Ca/Fe] compared to typical halo stars at similar metallicity. The observed variations in radial velocity from several epochs of (low- and high-resolution) spectroscopic follow-up indicate that SDSS J134338.67+484426.6 is a possible long-period binary. We also discuss the abundance trends in EMP stars for r-process elements, and compare with other magnesium-poor stars.

La depresión en la infancia desde la perspectiva de las taxonomías empíricas

OpenAIRE

López Soler, Concepción; López Pina, José Antonio

1998-01-01

En este trabajo se analiza la depresión infantil desde el modelo de taxonomías empíricas propuesto por Achenbach y Edelbrock. Se revisan algunos aspectos diferenciales en el diagnóstico de la depresión en menores y adultos. La parte empírica se cent

Parasites causing cerebral falciparum malaria bind multiple endothelial receptors and express EPCR and ICAM-1-binding PfEMP1

DEFF Research Database (Denmark)

Tuikue Ndam, Nicaise; Moussiliou, Azizath; Lavstsen, Thomas

2017-01-01

Background: Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) mediates the binding and accumulation of infected erythrocytes (IE) to blood vessels and tissues. Specific interactions have been described between PfEMP1 and human endothelial proteins CD36, intercellular adhesion molecule-1...

Accelerated Time-Domain Modeling of Electromagnetic Pulse Excitation of Finite-Length Dissipative Conductors over a Ground Plane via Function Fitting and Recursive Convolution

Energy Technology Data Exchange (ETDEWEB)

Campione, Salvatore [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Warne, Larry K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sainath, Kamalesh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Basilio, Lorena I. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

In this report we overview the fundamental concepts for a pair of techniques which together greatly hasten computational predictions of electromagnetic pulse (EMP) excitation of finite-length dissipative conductors over a ground plane. In a time- domain, transmission line (TL) model implementation, predictions are computationally bottlenecked time-wise, either for late-time predictions (about 100ns-10000ns range) or predictions concerning EMP excitation of long TLs (order of kilometers or more ). This is because the method requires a temporal convolution to account for the losses in the ground. Addressing this to facilitate practical simulation of EMP excitation of TLs, we first apply a technique to extract an (approximate) complex exponential function basis-fit to the ground/Earth's impedance function, followed by incorporating this into a recursion-based convolution acceleration technique. Because the recursion-based method only requires the evaluation of the most recent voltage history data (versus the entire history in a "brute-force" convolution evaluation), we achieve necessary time speed- ups across a variety of TL/Earth geometry/material scenarios. Intentionally Left Blank

Evasion of Immunity to Plasmodium falciparum: Rosettes of Blood Group A Impair Recognition of PfEMP1

Science.gov (United States)

Moll, Kirsten; Palmkvist, Mia; Ch'ng, Junhong; Kiwuwa, Mpungu Steven; Wahlgren, Mats

2015-01-01

The ABO blood group antigens are expressed on erythrocytes but also on endothelial cells, platelets and serum proteins. Notably, the ABO blood group of a malaria patient determines the development of the disease given that blood group O reduces the probability to succumb in severe malaria, compared to individuals of groups A, B or AB. P. falciparum rosetting and sequestration are mediated by PfEMP1, RIFIN and STEVOR, expressed at the surface of the parasitized red blood cell (pRBC). Antibodies to these antigens consequently modify the course of a malaria infection by preventing sequestration and promoting phagocytosis of pRBC. Here we have studied rosetting P. falciparum and present evidence of an immune evasion mechanism not previously recognized. We find the accessibility of antibodies to PfEMP1 at the surface of the pRBC to be reduced when P. falciparum forms rosettes in blood group A RBC, as compared to group O RBC. The pRBC surrounds itself with tightly bound normal RBC that makes PfEMP1 inaccessible to antibodies and clearance by the immune system. Accordingly, pRBC of in vitro cloned P. falciparum devoid of ABO blood group dependent rosetting were equally well detected by anti-PfEMP1 antibodies, independent of the blood group utilized for their propagation. The pathogenic mechanisms underlying the severe forms of malaria may in patients of blood group A depend on the ability of the parasite to mask PfEMP1 from antibody recognition, in so doing evading immune clearance. PMID:26714011

A review of mortality associated with elongate mineral particle (EMP) exposure in occupational epidemiology studies of gold, talc, and taconite mining.

Science.gov (United States)

Mandel, Jeffrey H; Alexander, Bruce H; Ramachandran, Gurumurthy

2016-12-01

Mining of gold, taconite, and talc may involve exposure to elongate mineral particles (EMP). The involved EMPs are typically non-asbestiform, include dimensions that regulatory definitions exclude, and have been less studied. A review of the literature was undertaken for this exposure and occupational epidemiological studies that occur in gold, talc, and taconite mining. Quantitative EMP exposure information in these industries is incomplete. However, there are consistent findings of pneumoconiosis in each of these types of mining. A recent case-control study suggests a possible association between this exposure and mesothelioma. Lung cancer is inconsistently reported in these industries and is an unlikely outcome of non-asbestiform EMP exposure. There is evidence of cardiovascular mortality excess across all of these types of mining. Non-malignant respiratory disease and cardiovascular mortality have been consistently increased in these industries. Further investigation, including additional insights for the role of non-asbestiform EMP, is warranted. Am. J. Ind. Med. 59:1047-1060, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Evasion of immunity to Plasmodium falciparum malaria by IgM masking of protective IgG epitopes in infected erythrocyte surface-exposed PfEMP1

DEFF Research Database (Denmark)

Barfod, Lea; Dalgaard, Michael B; Pleman, Suzan T

2011-01-01

1 (PfEMP1) family is central to both. Here, we present evidence of a P. falciparum evasion mechanism not previously documented: the masking of PfEMP1-specific IgG epitopes by nonspecific IgM. Nonspecific IgM binding to erythrocytes infected by parasites expressing the PfEMP1 protein VAR2CSA...

observaciones empíricas

Directory of Open Access Journals (Sweden)

Beatriz González Vázquez

2007-01-01

Full Text Available En el desarrollo y éxito de los espacios innovadores las relaciones entre los agentes integrantes de los mismos resultan esenciales. En este artículo se analizan las redes de relaciones en varias áreas tecnológicas, con el objetivo de comprobar si existe un mismo modelo en todas ellas. La red en dichos espacios se estudia tanto desde una perspectiva reticular, apoyándose en los atributos de las empresas y en las variables relacionales extraídas de los flujos entre las mismas, como desde la búsqueda de un modelo cuantitativo explicativo. El análisis empírico se realiza en las redes de tres Parques Tecnológicos, y de los resultados se extrae que la morfología de la red está influenciada por la estrategia de crecimiento que haya mantenido la dirección del parque en función de las condiciones industriales de su área geográfica. El análisis cuantitativo confirma el modelo centro-periferia observado en las redes.

Experimental study on the EMP failure mode of DC solid state relay

International Nuclear Information System (INIS)

Sun Beiyun; Chen Xiangyue; Zhai Aibin; Mao Congguang

2009-01-01

DC solid state relay is a new type switch device without touch point, and is extensive used by aviation and spaceflight technique. In this paper, the EMP failure modes of solid state relays were obtained by current injection method. (authors)

Searching for Single Pulses Using Heimdall

Science.gov (United States)

Walsh, Gregory; Lynch, Ryan

2018-01-01

In radio pulsar surveys, the interstellar medium causes a frequency dependent dispersive delay of a pulsed signal across the observing band. If not corrected, this delay substantially lowers S/N and makes most pulses undetectable. The delay is proportional to an unknown dispersion measure (DM), which must be searched over with many trial values. A number of new, GPU-accelerated codes are now available to optimize this dedispersion task, and to search for transient pulsed radio emission. We report on the use of Heimdall, one such GPU-accelerated tree dedispersion utility, to search for transient radio sources in a Green Bank Telescope survey of the Cygnus Region and North Galactic Plane. The survey is carried out at central frequency of 820 MHz with a goal of finding Fast Radio Bursts, Rotating Radio Transients, young pulsars, and millisecond pulsars. We describe the the survey, data processing pipeline, and follow-up of candidate sources.

Hemiparesia esquerda consecutiva a empeçonhamento: Por Bothrops Jararacussu

Directory of Open Access Journals (Sweden)

Napoleão L. Teixeira

1944-09-01

Full Text Available O A. apresenta uma observação de hemiparesia esquerda, consecutiva a envenenamento por Bothrops Jararacussu. É o segundo caso que publica, com idêntica etiologia; além das suas, há duas outras observações semelhantes, de Octávio de Magalhães. Depois de discorrer sobre as hemiplegias cerebrais infantis - mais comuns - lembra que estas nem sempre se acompanham de espasticidade, podendo apresentar-se, raramente, com hipotonia muscular, ou mesmo de coréia, atetose, ou movimentos córeo-atetóticos que falam em favor de comprometimento extrapiramidal. Assinala, também, que crises epileptiformes - generalizadas ou parciais - podem ocorrer, o mesmo se podendo dizer de distúrbios psíquicos. Traduzir-se-iam, estes, por déficit intelectual marcado, podendo ir desde a debilidade mental até a idiotia; ou então, mesmo quando não há aparente comprometimento da esfera intelectual, por perturbações da afetividade, da vontade e do pragmatismo. Passando em revista as causas mais frequentes das hemiplegias cerebrais infantis, abre lugar, dentre elas, para os empeçonhamentos ofídico e escorpiônico (Magalhães e Guimarães. Estuda, a seguir, a patogenia das hemiplegias no decurso dos referidos empeçonhamentos, alinhando as hipóteses correntes, da preferência de conceituadas autoridades no assunto. Transcreve, finalmente, sua observação clínica, da qual se pode concluir, sem dúvida possível, haver, no caso "que apresenta, estreita e imediata ligação entre o envenenamento ofídico e a hemiparesia em estudo. O observado seria portador, além do mais, de crises epileptiformes generalizadas, aparecidas logo a seguir ao empeçonhamento. Além da fotografia do caso que apresenta, mostra-nos o A. outra, de caso anteriormente publicado, este, porém, de hemiplegia cerebral infantil típica, instalada aos 11 anos, após picada de Bothrops jararaca.

Contra um Fetichismo nos Estudos Empíricos em Direito Internacional: Moldura Intencional e o Esvaziamento Significativo da Empiria

Directory of Open Access Journals (Sweden)

Artur Roberto Capella Giannattasio

2018-04-01

Full Text Available Os estudos em Direito Internacional no Brasil têm se aproximado de uma tendência neo-realista do Direito, a qual visa a usar técnicas empíricas na construção e na apresentação de seu objeto para verificar as condições materiais de criação e aplicação do Direito Internacional. Apesar da relevância dessa abordagem para aprimorar o conhecimento jurídico-científico internacional, este trabalho suscita um alerta fenomenológico de matriz husserliana. A discussão recente em torno da criação de uma Corte Constitucional Internacional (CCI se mostra um exemplo ilustrativo. A partir de análise qualitativa documental de fontes primárias e secundárias relativas à CCI, este estudo ressalta que um mesmo material empírico pode sustentar argumentos divergentes - no caso, reforço ou mitigação da autodeterminação dos povos. Essa divergência é interpretada epistemologicamente de acordo com o pensamento fenomenológico husserliano. Percebe-se que, independentemente do material empírico coletado, as conclusões se estabelecem de acordo com o posicionamento categorial do pesquisador. Argumenta-se assim que, apesar de haver uma aderência ao significante empírico, o processo de significação pouco depende dele, o qual tem seu sentido esvaziado. Por isso, argumenta-se que a busca de explicações sobre a origem e a efetividade do Direito Internacional não se restringe a uma dimensão estritamente empírica: apesar de ser necessário incorporar e aprimorar técnicas empíricas nos estudos em Direito Internacional, os limites de aplicação e de eficácia de suas normas jurídicas também derivam de condições imateriais vinculadas às restrições significativas relativas à posição categorial daqueles que as estudam e as operacionalizam.

DEVELOPING LINGUISTIC SKILLS AND ABILITIES IN EMP STUDENTS

Directory of Open Access Journals (Sweden)

Nataša Milosavljević

2012-03-01

Full Text Available English for medical purposes falls within the category of discipline-specific language learning. It is characterized by specific linguistic features and requires specific study that is possible to carry out using specially designed programmes. Reading skill is one way of learning strategy of English for medical purposes. Most often, students use this skill in order to obtain information for some particular topic from the area of medical science, or because they need some sort of instruction in order to carry out certain task. Vocabulary acquisition plays a very important role in EMP teaching. It is achieved best through learning vocabulary in context, rather than in isolation. One of the most important questions in EMP teaching is related to what grammatical constructions should be analysed and emphasised. Some types of these activities would include, for example, asking students to find examples of one particular structure in the text or fill in the blanks with the missing forms such as tenses, passive forms, prepositions, etc. Speaking skill represents productive skill the aim of which is communication. In order for foreign language communication to be suucessful, a student should know linguistic and cultural features of native speakers and follow certain rules and conventions that are not easy to define. It is of crucial importance that during teaching process students develop strategies and techniques that will help them use linguistic structures fluently, apply language in different situations, take part in discussions, and use acquired vocabulary in accurate and precise way.

Dissection of the role of PfEMP1 and ICAM-1 in the sensing of Plasmodium-falciparum-infected erythrocytes by natural killer cells.

Directory of Open Access Journals (Sweden)

Myriam Baratin

Full Text Available BACKGROUND: Host innate immunity contributes to malaria clinical outcome by providing protective inflammatory cytokines such as interferon-gamma, and by shaping the adaptive immune response. Plasmodium falciparum (Pf is the etiologic agent of the most severe forms of human malaria. Natural Killer (NK cells are lymphocytes of the innate immune system that are the first effectors to produce interferon-gamma in response to Pf. However, the molecular bases of Pf-NK cell recognition events are unknown. Our study focuses on the role of Pf erythrocyte membrane protein 1 (PfEMP1, a major Pf virulence factor. PfEMP1 is expressed on parasitized-erythrocytes and participates to vascular obstruction through the binding to several host receptors. PfEMP1 is also a pivotal target for host antibody response to Pf infection. METHODOLOGY/PRINCIPAL FINDINGS: Using genetically-engineered parasite mutant strains, a human genetic deficiency, and blocking antibodies, we identified two receptor-ligand pairs involved in two uncoupled events occurring during the sensing of Pf infection by NK cells. First, PfEMP1 interaction with one of its host receptor, chondroitin sulfate A, mediates the cytoadhesion of Pf-infected erythrocytes to human NK cell lines, but is not required for primary NK cell activation. Second, intercellular adhesion molecule-1 (ICAM-1, another host receptor for PfEMP1, is mandatory for NK cell interferon-gamma response. In this case, ICAM-1 acts via its engagement with its host ligand, LFA-1, and not with PfEMP1, consistent with the obligatory cross-talk of NK cells with macrophages for their production of interferon-gamma. CONCLUSION/SIGNIFICANCE: PfEMP1-independent but ICAM-1/LFA-1-dependent events occurring during NK cell activation by Pf highlight the fundamental role of cellular cooperation during innate immune response to malaria.

A semi-automated multiplex high-throughput assay for measuring IgG antibodies against Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) domains in small volumes of plasma

DEFF Research Database (Denmark)

Cham, Gerald K K; Kurtis, Jonathan; Lusingu, John

2008-01-01

-based assay was sensitive, accurate and reproducible. Four recombinant PfEMP1 proteins C17, D5, D9 and D12, selected on the basis that they showed a spread of median fluorescent intensity (MFI) values from low to high when analysed by the bead-based assay were analysed by ELISA and the results from both...... reactivity levels to twenty eight different recombinant PfEMP1 proteins were simultaneously measured using a single microliter of plasma. Thus, the assay reported here provides a useful tool for rapid and efficient quantification of antibody reactivity against PfEMP1 variants in human plasma....... of twenty nine PfEMP1 domains were PCR amplified from 3D7 genomic DNA, expressed in the Baculovirus system and purified by metal-affinity chromatography. The antibody reactivity level to the recombinant PfEMP1 proteins in human hyper-immune plasma was measured by ELISA. In parallel, these recombinant PfEMP1...

Exploring the SDSS Data Set with Linked Scatter Plots. I. EMP, CEMP, and CV Stars

Energy Technology Data Exchange (ETDEWEB)

Carbon, Duane F.; Henze, Christopher; Nelson, Bron C., E-mail: Duane.F.Carbon@nasa.gov [NASA Ames Research Center, NASA Advanced Supercomputing Facility, Moffett Field, CA, 94035-1000 (United States)

2017-02-01

We present the results of a search for extremely metal-poor (EMP), carbon-enhanced metal-poor (CEMP), and cataclysmic variable (CV) stars using a new exploration tool based on linked scatter plots (LSPs). Our approach is especially designed to work with very large spectrum data sets such as the SDSS, LAMOST, RAVE, and Gaia data sets, and it can be applied to stellar, galaxy, and quasar spectra. As a demonstration, we conduct our search using the SDSS DR10 data set. We first created a 3326-dimensional phase space containing nearly 2 billion measures of the strengths of over 1600 spectral features in 569,738 SDSS stars. These measures capture essentially all the stellar atomic and molecular species visible at the resolution of SDSS spectra. We show how LSPs can be used to quickly isolate and examine interesting portions of this phase space. To illustrate, we use LSPs coupled with cuts in selected portions of phase space to extract EMP stars, CEMP stars, and CV stars. We present identifications for 59 previously unrecognized candidate EMP stars and 11 previously unrecognized candidate CEMP stars. We also call attention to 2 candidate He ii emission CV stars found by the LSP approach that have not yet been discussed in the literature.

Electromagnetic pulse (EMP) radiation by laser interaction with a solid H.sub.2./sub. ribbon

Czech Academy of Sciences Publication Activity Database

De Marco, Massimo; Krása, Josef; Cikhardt, J.; Velyhan, Andriy; Pfeifer, Miroslav; Dudžák, Roman; Dostál, Jan; Krouský, Eduard; Limpouch, J.; Pisarczyk, T.; Kalinowska, Z.; Chodukowski, T.; Ullschmied, Jiří; Giuffrida, Lorenzo; Chatain, D.; Perin, J.P.; Margarone, Daniele

2017-01-01

Roč. 24, č. 8 (2017), s. 1-6, č. článku 083103. ISSN 1070-664X R&D Projects: GA MŠk EF15_008/0000162; GA ČR GA16-07036S; GA MŠk(CZ) LD14089; GA MŠk LQ1606 EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser-produced plasma * electromagnetic pulse * solid hydrogen ribbon Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.115, year: 2016

Characterization of electromagnetic pulse welding joints for advanced steels (ODS) welding applications

International Nuclear Information System (INIS)

Buddu, Ramesh Kumar; Shaikh, Shamsuddin; Raole, P.M.; Sarkar, B.

2015-01-01

Advanced fusion reactors structural materials (like in case of TBM and, first wall components) have several operation challenges due to the demanding high temperature exposure conditions (∼800°C) and low neutron radiation effects. The present paper reports the preliminary case studies carried out on steel and copper EMP joints and their properties characterization towards establishing this technology for ODS alloys. The EMP joints in form of tubes are fabricated and tested (typical process parameters ∼ Voltage 25 kV, Current ∼600-800 kA, Max. energy ∼ 50 kJ, and 50 sec duty cycle as major process parameters). The weld joints are further characterized by X-ray radiography and found that there were no measureable defects/discontinuities across the weld interface. This indicates the good process of joining and acceptable. Characterization studies like microstructure, interface grain orientation features, deformation, hardness has been carried out. SEM studies also carried to check the interface status and some interesting features of discontinuities are observed which are not exclusively revealed by radiography tests. Hardness survey also revealed that there is no much variation in the both parent materials as well at weld zone indicating the no hardening affects like in arc/beam weld process. EMP joining has potential features for the joining requirements of ODS kind typical metallurgical requirements

Mapping the transcription start points of the Staphylococcus aureus eap, emp, and vwb promoters reveals a conserved octanucleotide sequence that is essential for expression of these genes.

Science.gov (United States)

Harraghy, Niamh; Homerova, Dagmar; Herrmann, Mathias; Kormanec, Jan

2008-01-01

Mapping the transcription start points of the eap, emp, and vwb promoters revealed a conserved octanucleotide sequence (COS). Deleting this sequence abolished the expression of eap, emp, and vwb. However, electrophoretic mobility shift assays gave no evidence that this sequence was a binding site for SarA or SaeR, known regulators of eap and emp.

Implicaciones teóricas y empíricas de la nueva definición de desempleo en Colombia.

OpenAIRE

Guataquí, Juan; Taborda, Rodrigo

2005-01-01

En junio de 2000 Colombia adoptó una nueva definición de desempleo siguiendo los estándares de la OIT. Este cambio implicó una reducción de la tasa de desempleo del orden de dos puntos porcentuales. En este documento contrastamos el caso Colombiano con las experiencias de otros países en términos de la transformación metodológica y sus implicaciones empíricas. Posteriormente, evaluamos el soporte empírico del cambio de metodología. Nuestros resultados sugieren implicaciones esp...

Implementing network constraints in the EMPS model

Energy Technology Data Exchange (ETDEWEB)

Helseth, Arild; Warland, Geir; Mo, Birger; Fosso, Olav B.

2010-02-15

This report concerns the coupling of detailed market and network models for long-term hydro-thermal scheduling. Currently, the EPF model (Samlast) is the only tool available for this task for actors in the Nordic market. A new prototype for solving the coupled market and network problem has been developed. The prototype is based on the EMPS model (Samkjoeringsmodellen). Results from the market model are distributed to a detailed network model, where a DC load flow detects if there are overloads on monitored lines or intersections. In case of overloads, network constraints are generated and added to the market problem. Theoretical and implementation details for the new prototype are elaborated in this report. The performance of the prototype is tested against the EPF model on a 20-area Nordic dataset. (Author)

Development of a field measurement instrument for nuclear electromagnetic pulse (NEMP) based on signal transmission through fiber

International Nuclear Information System (INIS)

Song Wenwu; Zhang Chuandong; Liu Yi; Chen Jiuchun; Fan Youwen

2007-01-01

This paper deals with design principles, development and performance of a field measurement instrument for nuclear electromagnetic pulse (EMP) based on signal transmission through fiber. To determine the minimum band width this instrument needs, we analyze cutoff spectrum of a time domain double exponential signal, employing Fast Fourier Transform (FFT), and get its inverse transform signal. Then we design the circuit of laser device and the circuit of measuring device according to previous analysis. This instrument meets requirements of related regulations. Its specifications meet requirements of NEMP hazard protection research and can be of great significance to it. (authors)

A survey for sharply pulsed emissions

International Nuclear Information System (INIS)

Cole, T.W.; Ekers, R.D.

1979-01-01

Sharply pulsed emissions are relevant to the search for extraterrestrial intelligence. Although conventional wisdom in this area has concentrated on very narrow bandwidth signals at some preffered frequency, the authors argue the complementary approach of searching for emissions narrow in time rather than frequency. The results of searches for signals from G- and K-type stars, which produced one interesting event, and globular dusters X-ray sources and the galactic centre, which only produced noise, are presented

α2-macroglobulin can crosslink multiple Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) molecules and may facilitate adhesion of parasitized erythrocytes

DEFF Research Database (Denmark)

Stevenson, Liz; Laursen, Erik; Cowan, Graeme J

2015-01-01

-macroglobulin (α2M), which is both required and sufficient for rosetting mediated by the PfEMP1 protein HB3VAR06 and some other rosette-mediating PfEMP1 proteins. We map the α2M binding site to the C terminal end of HB3VAR06, and demonstrate that α2M can bind at least four HB3VAR06 proteins, plausibly....... Together, our results are evidence that P. falciparum parasites exploit α2M (and IgM) to expand the repertoire of host receptors available for PfEMP1-mediated IE adhesion, such as the erythrocyte carbohydrate moieties that lead to formation of rosettes. It is likely that this mechanism also affects IE...

El enfoque empírico-inductivo y los problemas de la investigación social en Venezuela

Directory of Open Access Journals (Sweden)

Sorayda Rincón

2001-05-01

Full Text Available El hombre históricamente ha estudiado el conocimiento humano, buscando diferenciar el conocimiento vulgar del conocimiento científico. Existen diversas formas de producir el conocimiento científico que comienzan a formalizarse antes del siglo XX y en el siglo XX. En el siglo XX uno de los enfoques más importantes para la producción de conocimiento fue el enfoque empírico inductivo (positivismo que aún hoy día tiene gran influencia en las ciencias sociales en Venezuela. Es por ello, que la presente investigación tiene como propósito disertar de manera teórica acerca del enfoque empírico inductivo, su influencia y limitaciones en la producción del conocimiento científico en las ciencias sociales; así como, conocer y describir la opinión de los profesores universitarios sobre el mismo y su utilidad en las asesorías de tesis de pre-grado y postgrado. Para lograr este último objetivo, se utilizó un sondeo de opinión a los profesores universitarios sobre los criterios fundamentales del enfoque empírico inductivo, a saber: criterio de demarcación, inducción probabilística, lenguaje lógico y unificación de la ciencia. Los datos obtenidos del sondeo de opinión se tabularon a través de estadística descriptiva, con análisis de frecuencia. Obteniendo como conclusión que este enfoque es aún utilizado por muchos investigadores en el área de lo social, que a pesar que en el discurso muchos niegan su uso, en las asesorías de tesis lo promueven, orientando las mismas hacia un referente empírico y generalizando a partir de probabilidades y estadísticas

Relaciones Empíricas Entre Empresas y Bancos. Una Visión Financiera Relaciones Empíricas Entre Empresas y Bancos. Una Visión Financiera

Directory of Open Access Journals (Sweden)

Andrea Escobar Grisales

2003-12-01

Full Text Available The research group on economics and business carried out the project "theoretical and empiricalaspects of firms – banks" relationship. The general objective was developing an investigationabout the channels and variables through which a relationship is establish between firms returnand performance, on one hand, and banks´ solvency and returns´ on the other.The main purpose of this paper is discussing the importance of firms´ financial management onfinancial sector credit policy establishment.El Grupo de Estudios en Economía y Empresa desarrolló, durante 2003, el proyecto Aspectosteóricos y empíricos de la relación empresas-bancos, cuyo objetivo general fue realizar una indagación sobre los canales y las variables a través de los cuales se establece una relación entre la rentabilidad y desempeño de las empresas, con la solidez y rentabilidad de los bancos (con datos de la economía colombiana para el lapso 1995-2000: para ello, se realizaron dos ejercicios, uno de carácter estadístico y otro de análisis financiero. El propósito de este artículo es presentar, en detalle, el análisis financiero de las relaciones empíricas entre bancos y empresas del sector real.

EMP Attachment 3 DOE-SC PNNL Site Dose Assessment Guidance

Energy Technology Data Exchange (ETDEWEB)

Snyder, Sandra F.

2011-12-21

This Dose Assessment Guidance (DAG) describes methods to use to determine the Maximally-Exposed Individual (MEI) location and to estimate dose impact to that individual under the U.S. Department of Energy Office of Science (DOE-SC) Pacific Northwest National Laboratory (PNNL) Site Environmental Monitoring Plan (EMP). This guidance applies to public dose from radioactive material releases to the air from PNNL Site operations. This document is an attachment to the Pacific Northwest National Laboratory (PNNL) Environmental Monitoring Plan (EMP) and describes dose assessment guidance for radiological air emissions. The impact of radiological air emissions from the U.S. Department of Energy Office of Science (DOE-SC) PNNL Site is indicated by dose estimates to a maximally exposed member of the public, referred to as the maximally exposed individual (MEI). Reporting requirements associated with dose to members of the public from radiological air emissions are in 40 CFR Part 61.94, WAC 246-247-080, and DOE Order 458.1. The DOE Order and state standards for dose from radioactive air emissions are consistent with U.S. Environmental Protection Agency (EPA) dose standards in 40 CFR 61.92 (i.e., 10 mrem/yr to a MEI). Despite the fact that the current Contract Requirements Document (CRD) for the DOE-SC PNNL Site operations does not include the requirement to meet DOE CRD 458.1, paragraph 2.b, public dose limits, the DOE dose limits would be met when EPA limits are met.

Chemical, Biological, and Radiological (CBR) Contamination Survivability, Small Items of Equipment

Science.gov (United States)

2012-06-22

contaminated with CWAs. May cause hardening or swelling of the sealant, which may weaken the seal. Rivet Stainless steel Not expected to have any effect...fallout, and nuclear survivability, which covers initial nu- clear weapon effects including Electromagnetic Pulse (EMP). Combat Developer . A...EA environmental assessment ECBC Edgewood Chemical Biological Center EMP electromagnetic pulse FD/SC Failure Definition/Scoring Criteria FM

STATIC{sub T}EMP: a useful computer code for calculating static formation temperatures in geothermal wells

Energy Technology Data Exchange (ETDEWEB)

Santoyo, E. [Universidad Nacional Autonoma de Mexico, Centro de Investigacion en Energia, Temixco (Mexico); Garcia, A.; Santoyo, S. [Unidad Geotermia, Inst. de Investigaciones Electricas, Temixco (Mexico); Espinosa, G. [Universidad Autonoma Metropolitana, Co. Vicentina (Mexico); Hernandez, I. [ITESM, Centro de Sistemas de Manufactura, Monterrey (Mexico)

2000-07-01

The development and application of the computer code STATIC{sub T}EMP, a useful tool for calculating static formation temperatures from actual bottomhole temperature data logged in geothermal wells is described. STATIC{sub T}EMP is based on five analytical methods which are the most frequently used in the geothermal industry. Conductive and convective heat flow models (radial, spherical/radial and cylindrical/radial) were selected. The computer code is a useful tool that can be reliably used in situ to determine static formation temperatures before or during the completion stages of geothermal wells (drilling and cementing). Shut-in time and bottomhole temperature measurements logged during well completion activities are required as input data. Output results can include up to seven computations of the static formation temperature by each wellbore temperature data set analysed. STATIC{sub T}EMP was written in Fortran-77 Microsoft language for MS-DOS environment using structured programming techniques. It runs on most IBM compatible personal computers. The source code and its computational architecture as well as the input and output files are described in detail. Validation and application examples on the use of this computer code with wellbore temperature data (obtained from specialised literature) and with actual bottomhole temperature data (taken from completion operations of some geothermal wells) are also presented. (Author)

Effects of electromagnetic radiation on morphology and TGF-β3 expression in mouse testicular tissue.

Science.gov (United States)

Luo, Yaning; Wang, Xiaowu; Chen, Yongbin; Xu, Shenglong; Ding, Guirong; Shi, Changhong

2013-08-09

Exposure to electromagnetic pulses in certain doses may lead to increase in the permeability of the blood testes barrier (BTB) in mice, which in turn affects spermatogenesis, penetration and spermiation. TGF-β3 is a key molecule involved in BTB permeability via regulation of tight junction proteins, and it participates in regulating spermatogenesis, synthesis of steroids and production of the extracellular matrix in testicular tissue. Therefore, it is hypothesized that TGF-β3 plays important roles in electromagnetic pulse (EMP)-induced changes in BTB permeability. In the present study, we carried out whole-body irradiation on mice using EMP of different intensities. No obvious pathological changes or significant increase in apoptosis was detected in testicular tissues after exposure to 100 and 200 pulses of intensity 200kV/m; however, with 400 pulses we observed the degeneration and shrinkage of testicular tissues along with a significant increase in apoptotic rate. Moreover, in the 100- and 200-EMP groups, a non-significant increase in TGF-β3 mRNA and protein expression was observed, whereas in the 400-EMP group a significant increase was observed (P<0.05). These results indicate that increase in the apoptotic rate of testicular tissues and increase in TGF-β3 expression may be one of the mechanisms for EMP-induced increase in BTB permeability in mice. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Applications of ultra-short pulsed laser ablation: thin films deposition and fs/ns dual-pulse laser-induced breakdown spectroscopy

International Nuclear Information System (INIS)

Teghil, R; De Bonis, A; Galasso, A; Santagata, A; Albano, G; Villani, P; Spera, D; Parisi, G P

2008-01-01

In this paper, we report a survey of two of the large number of possible practical applications of the laser ablation performed by an ultra-short pulse laser, namely pulsed laser deposition (PLD) and fs/ns dual-pulse laser-induced breakdown spectroscopy (DP-LIBS). These applications differ from those using just longer pulsed lasers as a consequence of the distinctive characteristics of the plasma produced by ultra-short laser beams. The most important feature of this plasma is the large presence of particles with nanometric size which plays a fundamental role in both applications.

A specific PfEMP1 is expressed in P. falciparum sporozoites and plays a role in hepatocyte infection

DEFF Research Database (Denmark)

Zanghì, Gigliola; Vembar, Shruthi S; Baumgarten, Sebastian

2018-01-01

Heterochromatin plays a central role in the process of immune evasion, pathogenesis, and transmission of the malaria parasite Plasmodium falciparum during blood stage infection. Here, we use ChIP sequencing to demonstrate that sporozoites from mosquito salivary glands expand heterochromatin......_SpzPfEMP1. Overall, we show that the epigenetic signature of var genes is reset in mosquito stages. Moreover, the identification of a strain-specific sporozoite PfEMP1 is highly relevant for vaccine design based on sporozoites....

Chemical, Biological, and Radiological (CBR) Contamination Survivability: Large Item Interiors

Science.gov (United States)

2012-06-22

CWAs. May cause hardening or swelling of the sealant, which may weaken the seal. Rivet Stainless steel Not expected to have any effect. Not... Electromagnetic Pulse (EMP). TOP 08-2-509 22 June 2012 A-2 APPENDIX A. EXPLANATION OF TERMS. Combat Developer. A category of sponsor...Edgewood Chemical Biological Center EMP electromagnetic pulse FD/SC Failure Definition/Scoring Criteria FM Field Manual FP fluorescent particle

La relación entre creatividad y expertise: contribuciones teóricas y empíricas

Directory of Open Access Journals (Sweden)

Afonso C. T. Galvao

2009-06-01

Full Text Available La creatividad y el expertise son temas que están recibiendo mayor atención de los inves­tigadores en distintos campos del conocimiento. Atributos personales asociados a la alta producción creativa, factores que favorecen el desarrollo, la expresión de la creatividad y el expertise, así como los procesos implicados en el desarrollo de la alta competencia y la creatividad, son temas que han sido objeto de numerosos estudios. El presente estudio pre­senta contribuciones teóricas y estudios empíricos acerca de la creatividad y el expertise. Se describen los elementos comunes para el desarrollo de la creatividad y el expertise, así como las características de los ambientes educativos que los promueven, los modelos teóricos y estudios empíricos.

Surface co-expression of two different PfEMP1 antigens on single Plasmodium falciparum-infected erythrocytes facilitates binding to ICAM1 and PECAM1

DEFF Research Database (Denmark)

Joergensen, Louise; Bengtsson, Dominique C; Bengtsson, Anja

2010-01-01

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) antigens play a major role in cytoadhesion of infected erythrocytes (IE), antigenic variation, and immunity to malaria. The current consensus on control of variant surface antigen expression is that only one PfEMP1 encoded by one var...

La geografía como disciplina integral: notas teóricas y empíricas

Directory of Open Access Journals (Sweden)

Mauricio Herrera Rodríguez

2010-01-01

Full Text Available Este artículo responde al llamado a trascender las divisiones tradicionales entre Ciencias Sociales, Naturales y Humanidades y subraya cómo la Geografía ha internalizado muchos de los más recientes aportes teóricos y empíricos elaborados desde estas áreas, en un esfuerzo transdisciplinario por entender mejor la realidad socioambiental. Para darle coherencia teórica y relevancia práctica a este sincretismo intelectual, se propone un marco conceptual no reduccionista, elaborado por el geógrafo humanista Robert D. Sack (1997, 2003, 2010. Con el objetivo de ilustrar su pertinencia empírica, se discuten algunos paralelismos entre sus postulados y los propuestos por la "Evaluación de los ecosistemas del milenio" (2003 y por varios intelectuales destacados. Finalmente, se señala su potencial para responder constructivamente tanto al avasallador triunfalismo del mercado, como al relativismo desorientador y paralizante que con frecuencia domina nuestras discusiones públicas e intelectuales.

A economia da sonegação: teorias e evidências empíricas The economics of tax evasion: theories and emprirical evidences

Directory of Open Access Journals (Sweden)

Marcelo Lettieri Siqueira

2005-12-01

Full Text Available Este artigo fornece uma visão geral da literatura teórica e empírica, nacional e internacional, acerca do estudo econômico da sonegação de impostos. Após apresentar uma definição da sonegação fiscal, em confronto com a elisão fiscal, e analisar a questão da mensuração da sonegação, discutimos o modelo básico de análise da sonegação fiscal de Allingham e Sandmo (1972, apresentamos uma revisão de suas numerosas extensões, avaliamos os efeitos da política de imposição tributária sobre a decisão de sonegar e, por fim, examinamos as evidências empíricas acerca do comportamento do contribuinte e dos níveis de sonegação gerados por ele.This paper provides an overview of the findings of the theoretical and empirical literature on tax evasion. After we define tax evasion, as opposed to tax avoidance, and analyze the question of the tax evasion measurement, we discuss the Allingham and Sandmo's basic model on tax evasion, with a brief review of its numerous extensions, we deal with the effects of tax enforcement policy on the decision to evade taxes, and, finally, we survey the empirical evidence on taxpayer compliance and the tax gap produced for the taxpayer behavior.

Damage effect and mechanism of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

Science.gov (United States)

Xiao-Wen, Xi; Chang-Chun, Chai; Gang, Zhao; Yin-Tang, Yang; Xin-Hai, Yu; Yang, Liu

2016-04-01

The damage effect and mechanism of the electromagnetic pulse (EMP) on the GaAs pseudomorphic high electron mobility transistor (PHEMT) are investigated in this paper. By using the device simulation software, the distributions and variations of the electric field, the current density and the temperature are analyzed. The simulation results show that there are three physical effects, i.e., the forward-biased effect of the gate Schottky junction, the avalanche breakdown, and the thermal breakdown of the barrier layer, which influence the device current in the damage process. It is found that the damage position of the device changes with the amplitude of the step voltage pulse. The damage appears under the gate near the drain when the amplitude of the pulse is low, and it also occurs under the gate near the source when the amplitude is sufficiently high, which is consistent with the experimental results. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900), and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (CAEP) (Grant No. 2015-0214.XY.K).

Nuclear EMP: stripline test method for measuring transfer impedance

International Nuclear Information System (INIS)

Miller, J.S.

1975-11-01

A method for measuring the transfer impedance of flat metal joints for frequencies to 100 MHz has been developed which makes use of striplines. The stripline method, which has similarities to the quadraxial method used for cylindrical components, is described and sets of test results are given. The transfer impedance of a simple joint is modeled as a spurious hyperbolic curve, and a close curve fit to transfer impedance test data from various samples is demonstrated for both the stripline and the quadraxial methods. Validity checks of the test data are discussed using the curve model and other criteria. The method was developed for testing riveted joints which form the avionics bays on B-1s. The joints must provide shielding from EMP currents

PENGOLAHAN BUAH DAN BIJI RAMBUTAN SEBAGAI MAKANAN TRADISIONAL KOKTAIL, MANISAN, EMPING BIJI RAMBUTAN DAN OBAT HERBAL YANG BERKHASIAT

Directory of Open Access Journals (Sweden)

Nuni Widiarti

2013-02-01

Full Text Available Kegiatan pengabdian kepada masyarakat berupa penyuluhan Pengolahan Buah Dan Biji Rambutan Sebagai Makanan Tradisional Koktail, Manisan, Emping Biji Rambutan Dan Obat Herbal Yang Berkhasiat bertujuan untuk memberikan pengetahuan kepada masyarakat khususnya ibu-ibu PKK dukuh kanggan Desa Wringinputih terhadap manfaat rambutan, dan biji rambutan terhadap kesehatan beserta bagaimana meningkatkan nilai jual rambutan dan biji rambutan pada saat panen raya. Khalayak sasaran dalam pengabdian masyarakat ini adalah ibu-ibu rumah tangga di dukuh Kanggan Desa Wringinputih khususnya warga RT 01 dan 02 RW XIII yang berjumlah 20 orang. Metode yang dilakukan dalam pngabdian ini adalah penyuluhan dan demonstrasi pembuatan emping serta manisan buah rambutan. Manfaat yang diperoleh dari hasil pengabdian ini adalah masyarakat menjadi tahu manfaat dari daun hingga akar dan buah rambutan terhadap berbagai penyakit dan kecantikan.

Cold moderators for pulsed neutron sources

International Nuclear Information System (INIS)

Carpenter, J.M.

1990-01-01

This paper reviews cold moderators in pulsed neutron sources and provides details of the performance of different cold moderator materials and configurations. Analytical forms are presented which describe wavelength spectra and emission time distributions. Several types of cooling arrangements used in pulsed source moderators are described. Choices of materials are surveyed. The author examines some of the radiation damage effects in cold moderators, including the phenomenon of ''burping'' in irradiated cold solid methane. 9 refs., 15 figs., 4 tabs

X-Ray Scattering Applications Using Pulsed X-Ray Sources

Energy Technology Data Exchange (ETDEWEB)

Larson, B.C.

1999-05-23

Pulsed x-ray sources have been used in transient structural phenomena investigations for over fifty years; however, until the advent of synchrotrons sources and the development of table-top picosecond lasers, general access to ligh temporal resolution x-ray diffraction was relatively limited. Advances in diffraction techniques, sample excitation schemes, and detector systems, in addition to IncEased access to pulsed sources, have ld tO what is now a diverse and growing array of pulsed-source measurement applications. A survey of time-resolved investigations using pulsed x-ray sources is presented and research opportunities using both present and planned pulsed x-ray sources are discussed.

The Application of GIS Viewshed Analysis to Roman Urban Studies: the Case-Study of Empúries, Spain

Directory of Open Access Journals (Sweden)

Alan E. Kaiser

2003-05-01

Full Text Available This article demonstrates the potential of applying GIS viewshed analysis to Roman urban studies. It examines the visual dynamics of the Roman city of Empúries, Spain, through an analysis of the visibility of, and view from, a temple and a domus within the city. The analysis proves that the two buildings in question would have had wide views of the Gulf of Roses to the east of the city, and could easily have been seen by people in boats in the Gulf, but they were virtually invisible from within the city and would certainly not have dominated the cityscape. The article concludes that the absence of the villa and temple from the intramural cityscape of Empúries cautions modern investigators of ancient cities against simply assuming that currently prominent ruins on hills or ridges were also highly visible from near as well as far in antiquity.

Volunteer Work, Religious Commitment, and Resting Pulse Rates.

Science.gov (United States)

Krause, Neal; Ironson, Gail; Hill, Peter C

2017-04-01

Research indicates that greater involvement in volunteer activities is associated with better health. We aim to contribute to this literature in two ways. First, rather than rely on self-reports of health, measured resting pulse rates serve as the dependent variable. Second, an effort is made to see if religious commitment moderates the relationship between volunteering and resting pulse rates. Data that come from a recent nationwide survey (N = 2265) suggest that volunteer work is associated with lower resting pulse rates. The results also reveal that the relationship between engaging in volunteer work and resting pulse rates improves among study participants who are more deeply committed to religion.

The value of load shifting. An estimate for Norway using the EMPS model

International Nuclear Information System (INIS)

Doorman, Gerard; Wolfgang, Ove

2006-05-01

An attempt is made to estimate the value of Load Shifting (LS) in the Norwegian system, using the EMPS model. A thorough update of the demand side model and cost estimates used in the model was done as a preparation for the project, and the report gives a comprehensive description of the demand models used. The LS measure that is analyzed is moving 600 MW demand in Norway from peak to lower demand hours during the day. The value of this was estimated both in a simplified manner (based on simulated price differences between these periods), and by simulations with the EMPS model and a subsequent calculation of the socio-economic surplus. Neither approaches showed any significant value. The results do not necessarily mean that the value in reality is zero - there are a number of limitations in the model which make it difficult to estimate the real value, like the representation of wind generation, demand variability, outages, exchange prices with continental Europe, flexibility of hydro and thermal generation, reserves and elasticity of demand in the short run. It was verified through sensitivity calculations that especially increasing reserve requirements and increasing the variability of wind generation increased price differences and therefore the value of LS. A number of improvements in the EMPS model and data are proposed to obtain a more suitable simulation model for this kind of analyses: 1) modeling of reserves, 2) representation of wind variability, 3) thermal generation models, 4) differentiation between long and short term price elasticity, 5) review of interconnection capacities, 6) use of quadratic losses and the 7) representation of more stochastic factors like e.g. outages in the simulations. Although the model at present clearly has its limitations with respect to estimating the value of LS, it appears that price differences between spot prices in the actual hours in reality are small. Comparison with Nord Pool spot prices for the years 2003

Implicaciones teóricas y empíricas de la nueva definición de desempleo en Colombia.

Directory of Open Access Journals (Sweden)

Juan Carlos Guataqui

2010-05-01

Full Text Available En junio de 2000 Colombia adoptó una nueva definición de desempleo siguiendo los estándares de la OIT. Este cambio implicó una reducción de la tasa de desempleo del orden de dos puntos porcentuales. En este documento contrastamos el caso Colombiano con las experiencias de otros países en términos de la transformación metodológica y sus implicaciones empíricas. Posteriormente, evaluamos el soporte empírico del cambio de metodología. Nuestros resultados sugieren implicaciones específicas sobre el desempleo estructural y su relación con el perfil educativo de los desempleados; por lo tanto, cuestionan la aplicación práctica de la definición estándar de desempleo de la OIT al caso colombiano.

Feasibility of Isolating Vulnerable Equipment of the Electric Power System from Sources of EMP

Science.gov (United States)

1978-03-01

is reclosed after the fault is cleared, the reclosure will probably be successful since no permanent conducting path for current exists. However...successive EMP-induced faults may cause reclosing circuit breakers and reclosers to lock out. 2. Lock out of reclosers and reclosing circuit breakers...Most distribution lines are protected by some sort of device that recloses the line after a fault is cleared. All such devices have a common

Hospitalidade Organizacional: Panorama Teórico-Empírico

Directory of Open Access Journals (Sweden)

José Alberto Carvalho dos Santos Claro

2015-10-01

Full Text Available O objetivo deste texto é o de apresentar as discussões teórico-conceituais sobre Hospitalidade, particularmente a vertente da Hospitalidade Organizacional (HO, que se ocupa das relações hospitaleiras no ambiente do espaço de trabalho. Trata-se de um estudo exploratório, baseado em revisão bibliográfica, seguida de pesquisa de campo por meio de levantamento junto a gestores de pessoas (especialistas ou juízes, sobre o entendimento do tema, visando contribuir para a futura criação de escala de medida para quantificar o grau de HO em uma organização. Como resultado, apresenta-se contribuição teórica para o amadurecimento desta tendência organizacional e indicadores que poderão ser futuramente usados em estudos empíricos e na construção de um instrumento com escala validada para ser utilizada em organizações em qualquer setor de atividade econômica. Palavras-chave: Hospitalidade. Hospitalidade Organizacional. Gestão de Pessoas.Organizational Hospitality: Theorical and Empirical Developments This paper aim is to present the theoretical and conceptual discussions about hospitality, particularly the  Organizational Hospitality (OH, which is concerned with the hospitable relations in the workplace. It’s an exploratory study, based on literature review and field survey with people managers (experts or judges about their understanding about the question. The result indicates that the development of organizational indicators could be used in future empirical studies and to the construction of a validated scale that can be used in any sector of the economic activity. Keywords: Hospitality. Organizational Hospitality. People Management. Indicators.José Alberto Carvalho dos Santos Claro – Doutor. Professor Adjunto da Universidade Federal de São Paulo [UNIFESP], Campus Baixada Santista, Santos, SP. Endereço Lattes http://lattes.cnpq.br/0865792662046289 E-mail: albertoclaro@albertoclaro.pro.br  

Instrumentation at pulsed neutron sources

International Nuclear Information System (INIS)

Carpenter, J.M.; Lander, G.H.; Windsor, C.G.

1984-01-01

Scientific investigations involving the use of neutron beams have been centered at reactor sources for the last 35 years. Recently, there has been considerable interest in using the neutrons produced by accelerator driven (pulsed) sources. Such installations are in operation in England, Japan, and the United States. In this article a brief survey is given of how the neutron beams are produced and how they can be optimized for neutron scattering experiments. A detailed description is then given of the various types of instruments that have been, or are planned, at pulsed sources. Numerous examples of the scientific results that are emerging are given. An attempt is made throughout the article to compare the scientific opportunities at pulsed sources with the proven performance of reactor installations, and some familiarity with the latter and the general field of neutron scattering is assumed. New areas are being opened up by pulsed sources, particularly with the intense epithermal neutron beams, which promise to be several orders of magnitude more intense than can be obtained from a thermal reactor

Contramedidas em segurança da informação e vulnerabilidade cibernética: evidência empírica de empresas brasileiras

OpenAIRE

Cortez, Igor Siqueira; Kubota, Luis Claudio

2013-01-01

Recentemente, uma série de ataques cibernéticos a empresas e governos no Brasil e no exterior tornou público o potencial impacto econômico desse tipo de atividade, do ponto de vista tanto privado quanto público. Existe extensa literatura econômica - teórica e empírica - que avalia os incentivos para que as empresas adotem ou não medidas de segurança da informação. No presente estudo foi desenvolvida uma avaliação empírica desse fenômeno no Brasil. Modelos logit e probit ordenado foram desenvo...

PULSE-SMART: Pulse-Based Arrhythmia Discrimination Using a Novel Smartphone Application.

Science.gov (United States)

McMANUS, David D; Chong, Jo Woon; Soni, Apurv; Saczynski, Jane S; Esa, Nada; Napolitano, Craig; Darling, Chad E; Boyer, Edward; Rosen, Rochelle K; Floyd, Kevin C; Chon, Ki H

2016-01-01

Atrial fibrillation (AF) is a common and dangerous rhythm abnormality. Smartphones are increasingly used for mobile health applications by older patients at risk for AF and may be useful for AF screening. To test whether an enhanced smartphone app for AF detection can discriminate between sinus rhythm (SR), AF, premature atrial contractions (PACs), and premature ventricular contractions (PVCs). We analyzed two hundred and nineteen 2-minute pulse recordings from 121 participants with AF (n = 98), PACs (n = 15), or PVCs (n = 15) using an iPhone 4S. We obtained pulsatile time series recordings in 91 participants after successful cardioversion to sinus rhythm from preexisting AF. The PULSE-SMART app conducted pulse analysis using 3 methods (Root Mean Square of Successive RR Differences; Shannon Entropy; Poincare plot). We examined the sensitivity, specificity, and predictive accuracy of the app for AF, PAC, and PVC discrimination from sinus rhythm using the 12-lead EKG or 3-lead telemetry as the gold standard. We also administered a brief usability questionnaire to a subgroup (n = 65) of app users. The smartphone-based app demonstrated excellent sensitivity (0.970), specificity (0.935), and accuracy (0.951) for real-time identification of an irregular pulse during AF. The app also showed good accuracy for PAC (0.955) and PVC discrimination (0.960). The vast majority of surveyed app users (83%) reported that it was "useful" and "not complex" to use. A smartphone app can accurately discriminate pulse recordings during AF from sinus rhythm, PACs, and PVCs. © 2015 Wiley Periodicals, Inc.

High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

National Research Council Canada - National Science Library

Wilson, Clay

2004-01-01

.... civilian computer systems to the effects of EMP has been discussed in the media. EMP can be produced on a large scale using a single nuclear explosion, and on a smaller, non-nuclear scale using a device with batteries or chemical explosives...

De-MA: a web Database for electron Microprobe Analyses to assist EMP lab manager and users

Science.gov (United States)

Allaz, J. M.

2012-12-01

Lab managers and users of electron microprobe (EMP) facilities require comprehensive, yet flexible documentation structures, as well as an efficient scheduling mechanism. A single on-line database system for managing reservations, and providing information on standards, quantitative and qualitative setups (element mapping, etc.), and X-ray data has been developed for this purpose. This system is particularly useful in multi-user facilities where experience ranges from beginners to the highly experienced. New users and occasional facility users will find these tools extremely useful in developing and maintaining high quality, reproducible, and efficient analyses. This user-friendly database is available through the web, and uses MySQL as a database and PHP/HTML as script language (dynamic website). The database includes several tables for standards information, X-ray lines, X-ray element mapping, PHA, element setups, and agenda. It is configurable for up to five different EMPs in a single lab, each of them having up to five spectrometers and as many diffraction crystals as required. The installation should be done on a web server supporting PHP/MySQL, although installation on a personal computer is possible using third-party freeware to create a local Apache server, and to enable PHP/MySQL. Since it is web-based, any user outside the EMP lab can access this database anytime through any web browser and on any operating system. The access can be secured using a general password protection (e.g. htaccess). The web interface consists of 6 main menus. (1) "Standards" lists standards defined in the database, and displays detailed information on each (e.g. material type, name, reference, comments, and analyses). Images such as EDS spectra or BSE can be associated with a standard. (2) "Analyses" lists typical setups to use for quantitative analyses, allows calculation of mineral composition based on a mineral formula, or calculation of mineral formula based on a fixed

La tasa de crecimiento garantizada de Harrod como ley del crecimiento económico. Una comprobación empírica

Directory of Open Access Journals (Sweden)

Bernal Bellón José Reyes Reyes

2008-12-01

Full Text Available En teoría del crecimiento hubo desarrollos importantes en la década de los 50 a partir del modelo de crecimiento poskeynesiano de Harrod (1939, los cuales buscaban solucionar teóricamente el problema de inestabilidad que presentaba este modelo. No obstante, no se ha realizado una comprobación empírica literal del modelo. En el presente trabajo se modifica el modelo de Harrod incluyendo el cambio técnico y se realiza una comprobación
empírica a través de diferentes metodologías. Se concluye que la tasa de crecimiento garantizada de Harrod tiende a ser una ley en teoría del crecimiento económico.

Antigenic variation and the genetics and epigenetics of the PfEMP1 erythrocyte surface antigens in Plasmodium falciparum malaria

DEFF Research Database (Denmark)

Arnot, David E; Jensen, Anja T R

2011-01-01

. Sterile immunity is not achieved and chronic parasitization of apparently healthy adults is the norm. In this article, we analyse the best understood malaria "antigenic variation" system, that based on Plasmodium falciparum's PfEMP1-type cytoadhesion antigens, and critically review recent literature...

Structure-guided identification of a family of dual receptor-binding PfEMP1 that is associated with cerebral malaria

DEFF Research Database (Denmark)

Lennartz, Frank; Adams, Yvonne; Bengtsson, Anja

2017-01-01

Cerebral malaria is a deadly outcome of infection by Plasmodium falciparum, occurring when parasite-infected erythrocytes accumulate in the brain. These erythrocytes display parasite proteins of the PfEMP1 family that bind various endothelial receptors. Despite the importance of cerebral malaria...

Strong and superstrong pulsed magnetic fields generation

CERN Document Server

Shneerson, German A; Krivosheev, Sergey I

2014-01-01

Strong pulsed magnetic fields are important for several fields in physics and engineering, such as power generation and accelerator facilities. Basic aspects of the generation of strong and superstrong pulsed magnetic fields technique are given, including the physics and hydrodynamics of the conductors interacting with the field as well as an account of the significant progress in generation of strong magnetic fields using the magnetic accumulation technique. Results of computer simulations as well as a survey of available field technology are completing the volume.

Antibody reactivity to conserved linear epitopes of Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1)

DEFF Research Database (Denmark)

Staalsø, T; Khalil, E A; Elhassan, I M

1998-01-01

recognising the conserved regions of PfEMP1 arise upon exposure to the parasite, and that these may be involved in the development of protection against malaria. Antibodies to the Pfalhesin peptide of the human aniontransporter, band3, were measured by the same method. The magnitude of this antibody response...

Meterwavelength Single-pulse Polarimetric Emission Survey. IV. The Period Dependence of Component Widths of Pulsars

Science.gov (United States)

Skrzypczak, Anna; Basu, Rahul; Mitra, Dipanjan; Melikidze, George I.; Maciesiak, Krzysztof; Koralewska, Olga; Filothodoros, Alexandros

2018-02-01

The core component width in normal pulsars, with periods (P) > 0.1 s, measured at the half-power point at 1 GHz, has a lower boundary line (LBL) that closely follows the P ‑0.5 scaling relation. This result is of fundamental importance for understanding the emission process and requires extended studies over a wider frequency range. In this paper we have carried out a detailed study of the profile component widths of 123 normal pulsars observed in the Meterwavelength Single-pulse Polarimetric Emission Survey at 333 and 618 MHz. The components in the pulse profile were separated into core and conal classes. We found that at both frequencies, the core, as well as the conal component widths versus period, had a LBL that followed the P ‑0.5 relation with a similar lower boundary. The radio emission in normal pulsars has been observationally shown to arise from a narrow range of heights around a few hundred kilometers above the stellar surface. In the past the P ‑0.5 relation has been considered as evidence for emission arising from last open dipolar magnetic field lines. We show that the P ‑0.5 dependence only holds if the trailing and leading half-power points of the component are associated with the last open field line. In such a scenario we do not find any physical motivation that can explain the P ‑0.5 dependence for both core and conal components as evidence for dipolar geometry in normal pulsars. We believe the period dependence is a result of a currently unexplained physical phenomenon.

Cultura intraemprendedora e innovación: un estudio empírico en las MIPYME turísticas colombianas

Directory of Open Access Journals (Sweden)

Edgar J. Gálvez Albarracín

2011-12-01

Full Text Available El objeto de este trabajo es verificar empíricamente la relación existente entre la cultura de intraemprendimiento y la innovación en las empresas. Para ello se realizó un estudio empírico con 68 MIPYME** del sector turístico de Colombia. Los resultados muestran que las prácticas asociadas al intraemprendimiento ejercen influencia positiva sobre la innovación de las MIPYME, y en especial, sobre la de sus procesos productivos y su gestión. Los hallazgos tienen implicaciones para los empresarios ya que les permite comprobar la utilidad del emprendimiento corporativo para el desarrollo de sus organizaciones. Muestra además al sector público, la academia y a las entidades de fomento, la importancia de impulsar programas de investigación, formación y asesoría en el campo del intraemprendimiento, para lograr mayor innovación y competitividad empresarial, lo cual puede redundar a su vez en mayor desarrollo regional y nacional

Structural Conservation Despite Huge Sequence Diversity Allows EPCR Binding by the PfEMP1 Family Implicated in Severe Childhood Malaria

DEFF Research Database (Denmark)

Lau, Clinton K.Y.; Turner, Louise; Jespersen, Jakob S.

2015-01-01

with severe childhood malaria. We combine crystal structures of CIDRa1:EPCR complexes with analysis of 885 CIDRa1 sequences, showing that the EPCR-binding surfaces of CIDRa1 domains are conserved in shape and bonding potential, despite dramatic sequence diversity. Additionally, these domains mimic features...... of the natural EPCR ligand and can block this ligand interaction. Using peptides corresponding to the EPCR-binding region, antibodies can be purified from individuals in malaria-endemic regions that block EPCR binding of diverse CIDRa1 variants. This highlights the extent to which such a surface protein family......The PfEMP1 family of surface proteins is central for Plasmodium falciparum virulence and must retain the ability to bind to host receptors while also diversifying to aid immune evasion. The interaction between CIDRa1 domains of PfEMP1 and endothelial protein C receptor (EPCR) is associated...

Condensed matter research using pulsed neutron sources: a bibliography

International Nuclear Information System (INIS)

Mildner, D.F.R.; Stirling, G.C.

1976-05-01

This report is an updated revision of RL-75-095 'Condensed Matter Research Using Pulsed Neutron Sources: A Bibliography'. As before, the survey lists published papers concerning (a) the production of high intensity neutron pulses suitable for thermal neutron scattering research, (b) moderating systems for neutron thermalization and pulse shaping, (c) techniques and instrumentation for diffraction and inelastic scattering at pulsed sources, and (d) their application to research problems concerning the structural and dynamical properties of condensed matter. Papers which deal with the white beam time-of-flight technique at steady state reactors have also been included. A number of scientists have brought to the author's attention papers which have been published since the previous edition. They are thanked and encouraged to continue the cooperation so that the bibliography may be updated periodically. (author)

La PYME innovadora mexicana ante la crisis económica. Un estudio empírico

OpenAIRE

Edwin Estrella Pacheco; Gabriel Góngora Biachi; Marlene Martín Méndez

2011-01-01

Este trabajo estudia el crecimiento y el empleo de las empresas industriales manufactureras que son innovadoras del estado de Yucatán, en México, durante 2007-2009, periodo de la crisis financiera global. El incremento del desempleo es consecuencia del cierre de empresas, para recortar gastos. Se estudia el impacto de dicha crisis comparando el efecto en aquellas empresas que son innovadoras, con aquellas que no lo son. Se realiza un estudio empírico a 138 PYME, usando una entrevista dirigida...

Meterwavelength Single-pulse Polarimetric Emission Survey. III. The Phenomenon of Nulling in Pulsars

Energy Technology Data Exchange (ETDEWEB)

Basu, Rahul; Mitra, Dipanjan; Melikidze, George I., E-mail: rahulbasu.astro@gmail.com [Janusz Gil Institute of Astronomy, University of Zielona Góra, ul. Szafrana 2, 65–516 Zielona Góra (Poland)

2017-09-10

A detailed analysis of nulling was conducted for the pulsars studied in the Meterwavelength Single-pulse Polarimetric Emission Survey. We characterized nulling in 36 pulsars including 17 pulsars where the phenomenon was reported for the first time. The most dominant nulls lasted for a short duration, less than five periods. Longer duration nulls extending to hundreds of periods were also seen in some cases. A careful analysis showed the presence of periodicities in the transition from the null to the burst states in 11 pulsars. In our earlier work, fluctuation spectrum analysis showed multiple periodicities in 6 of these 11 pulsars. We demonstrate that the longer periodicity in each case was associated with nulling. The shorter periodicities usually originate from subpulse drifting. The nulling periodicities were more aligned with the periodic amplitude modulation, indicating a possible common origin for both. The most prevalent nulls last for a single period and can be potentially explained using random variations affecting the plasma processes in the pulsar magnetosphere. On the other hand, longer-duration nulls require changes in the pair-production processes, which need an external triggering mechanism for the changes. The presence of periodic nulling puts an added constraint on the triggering mechanism, which also needs to be periodic.

Survey on modern pulsed high power lasers

International Nuclear Information System (INIS)

Witte, K.J.

1985-01-01

The requirements to be met by lasers for particle acceleration are partially similar to those already known for fusion lasers. The power level wanted in both caes is up to 100 TW or even more. The pulse durations favourable for laser accelerators are in the range from 1 ps to 1000 ps whereas fusion lasers require several ns. The energy range for laser accelerators is thus correspondingly smaller than that for fusion lasers: 1-100 kJ versus several 100 kJ. The design criteria of lasers meeting the requirements are discussed in the following. The CO 2 , iodine, Nd:glass and excimer lasers are treated in detail. The high repetition rate aspect will not be particularly addressed since for the present generation of lasers the wanted rates of far above 1 Hz are completely out of scope. Moreover, for the demonstration of principle these rates are not needed. (orig./HSI)

Condições de trabalho do jornalista: o que revela a pesquisa empírica

Directory of Open Access Journals (Sweden)

Juliana Bulhões Alberto Dantas

2017-03-01

Full Text Available Investigamos acerca do impacto das condições de trabalho do jornalista na saúde e na qualidade de vida deste profissional. Apresentamos aqui um relato com os primeiros resultados da pesquisa, a partir de uma síntese das três etapas de desenvolvimento do trabalho: pesquisa exploratória, pesquisa bibliográfica e pesquisa de campo. Enfatizamos os resultados colhidos no pré-teste do instrumento e o levantamento de dados empíricos obtidos a partir de entrevistas em profundidade.

Pulse carboxyhemoglobin-oximetry and cigarette smoking.

Science.gov (United States)

Sokolova-Djokić, L; Milosević, S; Skrbić, R; Salabat, R; Voronov, G; Igić, R

2011-01-01

We used a pulse carbon monoxide (CO)-oximeter to measure the levels of carboxyhemoglobin (COHb) in smokers and non-smokers. Our goal was to determine if this device could not only define smoking status, but also to increase accuracy of self-reported data at various surveys on smoking. Thirty-four healthy volunteers participated in this study. Twenty-two of them were current daily smokers; 12 participants were non-smokers who lived alone or with a nonsmoker, and who worked in non-smoking environment. Nicotine dependency level was determined by the modified Fagerstrom questionnaire. Blood COHb levels were measured with a pulse CO-oximeter (Masimo, Radical 7). The COHb levels in both moderate/heavy smokers and light smokers increased significantly after they smoked a single cigarette. This increase persisted for more than 6 h in the moderate/heavy smokers, while in the light smokers COHb levels returned to the baseline level after one hour. The pulse rate of all smokers increased significantly 20 min after smoking. We conclude that the CO-oximeter can detect smoking by moderate/heavy smokers and light smokers if they smoked 6 h or 20 min earlier, respectively. We concluded that it could be used as a validation test for smoking at the time of admission to the surgical facility and to increase smoking abstinence during preoperative and postoperative periods. This noninvasive, simple and inexpensive test may also be used at various surveys to increase accuracy of self-reports on smoking.

Survey of high-voltage pulse technology suitable for large-scale plasma source ion implantation processes

International Nuclear Information System (INIS)

Reass, W.A.

1994-01-01

Many new plasma processes ideas are finding their way from the research lab to the manufacturing plant floor. These require high voltage (HV) pulse power equipment, which must be optimized for application, system efficiency, and reliability. Although no single HV pulse technology is suitable for all plasma processes, various classes of high voltage pulsers may offer a greater versatility and economy to the manufacturer. Technology developed for existing radar and particle accelerator modulator power systems can be utilized to develop a modern large scale plasma source ion implantation (PSII) system. The HV pulse networks can be broadly defined by two classes of systems, those that generate the voltage directly, and those that use some type of pulse forming network and step-up transformer. This article will examine these HV pulse technologies and discuss their applicability to the specific PSII process. Typical systems that will be reviewed will include high power solid state, hard tube systems such as crossed-field ''hollow beam'' switch tubes and planar tetrodes, and ''soft'' tube systems with crossatrons and thyratrons. Results will be tabulated and suggestions provided for a particular PSII process

Mapping the binding site of a cross-reactive Plasmodium falciparum PfEMP1 monoclonal antibody inhibitory of ICAM-1 binding

DEFF Research Database (Denmark)

Lennartz, Frank; Bengtsson, Anja; Olsen, Rebecca W

2015-01-01

The virulence of Plasmodium falciparum is linked to the ability of infected erythrocytes (IE) to adhere to the vascular endothelium, mediated by P. falciparum erythrocyte membrane protein 1 (PfEMP1). In this article, we report the functional characterization of an mAb that recognizes a panel of P...

Pulse pile-up. I: Short pulses

International Nuclear Information System (INIS)

Wilkinson, D.H.

1990-07-01

The search for rare large pulses against an intense background of smaller ones involves consideration of pulse pile-up. Approximate methods are presented, based on ruin theory, by which the probability of such pile-up may be estimated for pulses of arbitrary form and of arbitrary pulse-height distribution. These methods are checked against cases for which exact solutions are available. The present paper is concerned chiefly with short pulses of finite total duration. (Author) (5 refs., 24 figs.)

Inadimplência no Brasil: Uma Análise das Evidências Empíricas

OpenAIRE

Mariane Daros; Nelson Guilherme Machado Pinto

2017-01-01

O objetivo deste trabalho consiste em analisar as evidências empíricas de estudos relacionados à inadimplência dentro do contexto brasileiro, verificando os estudos desses aspectos nas diversas regiões do país. Além disso, foram analisadas questões relacionadas ao panorama desses estudos a fim de verificar em quais pontos os trabalhos futuros desse tema podem vir a avançar. A partir da análise dos estudos publicados dentro da temática nota-se a existência de alguns pontos que não são aprofund...

Prácticas de presupuesto de capital: evaluación empírica en un grupo de empresas del sector de la construcción en Colombia

OpenAIRE

Ochoa Yepes, Julián

2014-01-01

El análisis empírico de presupuesto de capital o valoración de inversiones ha sido un tema ampliamente estudiado principalmente en países desarrollados como Estados Unidos, Reino Unido y Canadá -- Sin embargo la evidencia en países emergentes es escasa -- Mediante este artículo se pretende dar inicio a evidenciar las prácticas de presupuesto de capital a través de un estudio empírico realizado en un grupo de empresas del sector de la construcción en Colombia -- De las empresas encuestadas se ...

America’s Achilles Heel: Defense Against High-altitude Electromagnetic Pulse-policy vs. Practice

Science.gov (United States)

2014-12-12

between milestones. Recommendations will address both governmental and private sector approaches to EMP damage mitigation and consequence management. 15...governmental and private sector approaches to EMP damage mitigation and consequence management. iv ACKNOWLEDGMENTS This is study is dedicated to the men...check engine light flicker 1 James Wesley Rawles, Patriots: Surviving the Coming Collapse, 4th ed. (Berkeley, CA: Ulysses Press), 1. 1

Electromagnetic radiations from laser interaction with gas-filled Hohlraum

Science.gov (United States)

Yang, Ming; Yang, Yongmei; Li, Tingshuai; Yi, Tao; Wang, Chuanke; Liu, Shenye; Jiang, Shaoen; Ding, Yongkun

2018-01-01

The emission of intensive electromagnetic pulse (EMP) due to laser-target interactions at the ShenGuang-III laser facility has been evaluated by probes. EMP signals measured using the small discone antennas demonstrated two variation trends including a bilateral oscillation wave and a unilateral oscillation wave. The new trend of unilateral oscillation could be attributed to the hohlraum structure and low-Z gas in the hohlraum. The EMP waveform showed multiple peaks when the gas-filled hohlraum was shot by the high-power laser. Comparing the EMP signals with the verification of stimulated Raman scattering energy and hard x-ray energy spectrum, we found that the intensity of EMP signals decreased with the increase of the hohlraum size. The current results are expected to offer preliminary information to study physical processes on laser injecting gas-filled hohlraums in the National Ignition Facility implementation.

Critical Infrastructure Protection: EMP Impacts on the U.S. Electric Grid

Science.gov (United States)

Boston, Edwin J., Jr.

The purpose of this research is to identify the United States electric grid infrastructure systems vulnerabilities to electromagnetic pulse attacks and the cyber-based impacts of those vulnerabilities to the electric grid. Additionally, the research identifies multiple defensive strategies designed to harden the electric grid against electromagnetic pulse attack that include prevention, mitigation and recovery postures. Research results confirm the importance of the electric grid to the United States critical infrastructures system and that an electromagnetic pulse attack against the electric grid could result in electric grid degradation, critical infrastructure(s) damage and the potential for societal collapse. The conclusions of this research indicate that while an electromagnetic pulse attack against the United States electric grid could have catastrophic impacts on American society, there are currently many defensive strategies under consideration designed to prevent, mitigate and or recover from an electromagnetic pulse attack. However, additional research is essential to further identify future target hardening opportunities, efficient implementation strategies and funding resources.

Teoria da agência e franchising: evidência empírica para o caso brasileiro

OpenAIRE

Rigoni, Ramon Frigi

2015-01-01

O presente estudo tem um duplo objetivo: (i) analisar os determinantes da escolha das firmas por um modelo de franchising na estratégia de expansão de seus negócios, e (ii) analisar como os termos de um contrato de franchising podem potencialmente ser influenciados por questões relativas a compartilhamento de risco, problemas de incentivo relacionados ao risco moral (moral hazard) e restrições de recursos financeiros. Essa discussão se dará seguindo a abordagem empírica proposta por Lafontain...

PENGOLAHAN BUAH DAN BIJI RAMBUTAN SEBAGAI MAKANAN TRADISIONAL KOKTAIL, MANISAN, EMPING BIJI RAMBUTAN DAN OBAT HERBAL YANG BERKHASIAT

OpenAIRE

Nuni Widiarti; Sri Wahyuni; F Widhi Mahatmanti

2013-01-01

Kegiatan pengabdian kepada masyarakat berupa penyuluhan Pengolahan Buah Dan Biji Rambutan Sebagai Makanan Tradisional Koktail, Manisan, Emping Biji Rambutan Dan Obat Herbal Yang Berkhasiat bertujuan untuk memberikan pengetahuan kepada masyarakat khususnya ibu-ibu PKK dukuh kanggan Desa Wringinputih terhadap manfaat rambutan, dan biji rambutan terhadap kesehatan beserta bagaimana meningkatkan nilai jual rambutan dan biji rambutan pada saat panen raya. Khalayak sasaran dalam pengabdian masyarak...

Recommended E3 HEMP Heave Electric Field Waveform for the Critical Infrastructures. Volume 2

Science.gov (United States)

2017-07-31

horizontal electric (E) field, as this field can effectively couple to long power and communications lines and induce quasi-dc currents in these systems ...Department of Defense E electric field EMP electromagnetic pulse EPRI Electric Power Research Institute FERC Federal Energy Regulatory Commission GMD...North American Electric Reliability Corporation nT nanotesla S/m siemens/m UV ultraviolet V Volt ix PREFACE This EMP Commission Report

Realtime aspects of pulse-to-pulse modulation

International Nuclear Information System (INIS)

Steiner, R.; Riedel, C.; Roesch, W.

1992-01-01

The pulse-to-pulse modulation of the SIS-ESR control system is described. Fast response to operator interaction and to changes in process conditions is emphasized as well as the essential part played by the timing system in pulse-to-pulse modulation. (author)

Construction practices: Pulse builder survey results

Energy Technology Data Exchange (ETDEWEB)

Kadulski, R

This paper discusses the results of a nationwide builder survey on common building techniques, such as framing, insulation, airtight construction practices, testing for airtightness, windows, furnaces and water heaters, and ventilation. Results indicate that changes in construction were mainly influenced by the R-2000 program. The spread of R-2000 technology is reflected in the use of higher insulation levels than are called for by codes or than is normal practice, sealing of joints, and attention to air and vapour retarders as well as air tight drywall techniques combined with mechanical ventilation systems.

Evaluación de la orientación empática en estudiantes de medicina de la Universidad del Norte. Barranquilla (Colombia

Directory of Open Access Journals (Sweden)

Luz Marina Alonso Palacio

2013-01-01

Full Text Available Objetivo: Determinar el nivel de orientación empática de los estudiantes de medicina de la Universidad del Norte. Materiales y Métodos: Investigación de tipo descriptiva transversal. La población es - taba constituida por 859 estudiantes, de la cual se tomó una muestra de 345 estudiantes voluntarios (niveles: 1°, 2°, 3°, 4° y 5° año, (1°. n = 128, 2º. n = 102, 3°. n = 38, 4°. n = 41, y 5°. n = 36. Se aplicó, en 2012, la versión en español de la Escala de Empatía Médica de Jefferson ( EEMJ para estudiantes de medicina (versión S, validada en México y Chile y adaptada culturalmente a Colombia mediante el método de validación por criterio de jueces, se calculó: promedio, desviación y se aplicó análisis de varianza bifactorial para diferencia de medias y evaluar interacción entre las variables estudiadas. Resultados: La orientación empática presentó valores ubicados por encima del valor cen - tral del rango de la escala que oscila entre 20 y 140. No se encontraron diferencias signi - ficativas por género ni por año en las puntuaciones. Conclusiones: Los promedios de orientación empática presentaron tendencia casi cons - tante con fluctuaciones no significativas. Sería de gran valor investigar otras variables que pueden afectar la empatía.

3D modeling of lightning-induced electromagnetic pulses on Venus, Jupiter and Saturn

Science.gov (United States)

Pérez-Invernón, Francisco J.; Luque, Alejandro; Gordillo-Vázquez, Francisco J.

2017-04-01

Atmospheric electricity is a common phenomenon in some planets of The Solar System. We know that atmospheric discharges exist on Earth and gaseous planets; however, some characteristics of lightning on Saturn and Jupiter as well as their relevance on the effects of lightning in the atmospheres of these planets are still unknown. In the case of Venus, there exist some radio evidences of lightning, but the lack of optical observations suggests exploring indirect methods of detection, such as searching for lightning-induced transient optical emissions from the upper atmosphere. The Akatsuki probe, currently orbiting Venus, is equipped with a camera whose temporal resolution is high enough to detect optical emissions from lightning discharges and to measure nightglow enhancements. In this work, we extend previous models [1,2] to investigate the chemical impact and transient optical emissions produced by possible lightning-emitted electromagnetic pulses (EMP) in Venus, Saturn and Jupiter. Using a 3D FDTD ("Finite Differences Time Domain") model we solve the Maxwell equations coupled with the Langevin equation for electrons [3] and with a kinetic scheme, different for each planetary atmosphere. This method is useful to investigate the temporal and spatial impact of lightning-induced electromagnetic fields in the atmosphere of each planet for different lightning characteristics (e.g. energy released, orientation). This 3D FDTD model allows us to include the saturnian and jovian background magnetic field inclination and magnitude at different latitudes, and to determine the effects of different lightning channel inclinations. Results provide useful information to interpret lightning observations on giant gaseous planets and in the search for indirect optical signals from atmospheric discharge on Venus such as fast nightglow transient enhancements related to lightning as seen on Earth. Furthermore, we underline the observation of electrical discharges characteristics as a

Los conceptos innatos en la obra de Chomsky: definición y propuesta de un método empírico para su estudio

Directory of Open Access Journals (Sweden)

Oliver Müller

2013-06-01

Full Text Available Este artículo versa sobre los conceptos innatos: su definición, de acuerdo a la obra lingüística de Noam Chomsky, y el esbozo de un método que permita su estudio. A manera de introducción se refieren algunas concepciones académicas sobre la adquisición conceptual y se comenta la falta de un método de estudio empírico de los conceptos nativos. Enseguida, se presenta la definición que a lo largo del tiempo ha defendido Chomsky sobre dichos conceptos. Finalmente, se instauran de manera teórica las condiciones de un procedimiento empírico para el estudio de los conceptos innatos, titulado análisis semántico de corpus.

Overproduction, purification and crystallization of a chondroitin sulfate A-binding DBL domain from a Plasmodium falciparum var2csa-encoded PfEMP1 protein

International Nuclear Information System (INIS)

Higgins, Matthew K.

2008-01-01

A chondroitin sulfate A-binding DBL important in placental malaria has been overproduced, purified and crystallized. Diffraction data were collected to 1.9 Å resolution. The PfEMP1 proteins of the malaria parasite Plasmodium falciparum are inserted into the membrane of infected red blood cells, where they mediate adhesion to a variety of human receptors. The DBL domains of the var2csa-encoded PfEMP1 protein play a critical role in malaria of pregnancy, tethering infected cells to the surface of the placenta through interactions with the glycosaminoglycan carbohydrate chondroitin sulfate A (CSA). A CSA-binding DBL domain has been overproduced in a bacterial expression system, purified and crystallized. Native data sets extending to 1.9 Å resolution have been collected and phasing is under way

Overproduction, purification and crystallization of a chondroitin sulfate A-binding DBL domain from a Plasmodium falciparum var2csa-encoded PfEMP1 protein

Energy Technology Data Exchange (ETDEWEB)

Higgins, Matthew K., E-mail: mkh20@cam.ac.uk [Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom)

2008-03-01

A chondroitin sulfate A-binding DBL important in placental malaria has been overproduced, purified and crystallized. Diffraction data were collected to 1.9 Å resolution. The PfEMP1 proteins of the malaria parasite Plasmodium falciparum are inserted into the membrane of infected red blood cells, where they mediate adhesion to a variety of human receptors. The DBL domains of the var2csa-encoded PfEMP1 protein play a critical role in malaria of pregnancy, tethering infected cells to the surface of the placenta through interactions with the glycosaminoglycan carbohydrate chondroitin sulfate A (CSA). A CSA-binding DBL domain has been overproduced in a bacterial expression system, purified and crystallized. Native data sets extending to 1.9 Å resolution have been collected and phasing is under way.

Pulsed rf excited spectrometer having improved pulse width control

International Nuclear Information System (INIS)

1977-01-01

RF excitation for a spectrometer is obtained by pulse width modulating an RF carrier to produce the desired broadband RF exciting spectrum. The RF excitation includes a train of composite RF pulses, each composite pulse having a primary pulse portion of a first RF phase and a second pulse portion of a second RF phase opposite that of the first. In this manner, the finite rise and fall times of the primary pulse portion are compensated for by the corresponding rise and fall times of the secondary pulse portion. The primary pulse portion is lengthened by an amount equal to the secondary pulse portion so that the secondary pulse portion cancels the added primary pulse portion. In a spectrometer, the compensating second pulse component removes certain undesired side bands of the RF excitation caused by the finite rise and fall times of the applied RF pulses. The compensating second pulse component removes certain undesired side bands associated with each of the resonant lines of the excited resonance spectrum of the sample under analysis, particularly for wide band RF excitation

Plutarque contre Colotès contre Empédocle Plutarch against Colotes against Empedocles Plutarco contro Colote contro Empedocle

Directory of Open Access Journals (Sweden)

Alain Gigandet

2013-05-01

Full Text Available In the section of Against Colotes dedicated to the polemic that the Epicurean, in his writing, developed against Empedocles, Plutarch uses what he considers a bad procedure to traverse the area of dialectic and to arrive at that of the principles of Atomist physics, whose incoherence he feigns to demonstrate.Dans la partie du Contre Colotès consacrée à la polémique que l’épicurien, dans son écrit, développait contre Empédocle, Plutarque utilise ce qu’il considère comme un mauvais procès pour passer du terrain dialectique à celui des principes de la physique atomiste, dont il prétend montrer l’incohérence.Dans la partie du Contre Colotès consacrée à la polémique que l’épicurien, dans son écrit, développait contre Empédocle, Plutarque utilise ce qu’il considère comme un mauvais procès pour passer du terrain dialectique à celui des principes de la physique atomiste, dont il prétend montrer l’incohérence.

Bancos Cooperativos y Sociedades de Ahorro y Crédito en El Salvador: modelo de supervisión prudencial y análisis empírico del coeficiente de solvencia

OpenAIRE

Hernández, Ana Verónica

2013-01-01

Estudio bibliográfico empírico, con el que se presenta una propuesta de supervisión para la superintendencia financiera de El Salvador, que incluye requisitos mínimos a considerar por el auditor, tomando como base Basilea II, III y siguiendo el Modelo OSFI de Canadá. Además se presenta un estudio empírico sobre los determinantes del coeficiente patrimonial en bancos cooperativos y sociedades de ahorro y crédito de El Salvador. Economía Financiera y Contabilidad Máster en Investigación ...

Pulsed neutron generator system for astrobiological and geochemical exploration of planetary bodies

International Nuclear Information System (INIS)

Akkurt, Hatice; Groves, Joel L.; Trombka, Jacob; Starr, Richard; Evans, Larry; Floyd, Samuel; Hoover, Richard; Lim, Lucy; McClanahan, Timothy; James, Ralph; McCoy, Timothy; Schweitzer, Jeffrey

2005-01-01

A pulsed neutron/gamma-ray detection system for use on rovers to survey the elemental concentrations of Martian and Lunar surface and subsurface materials is evaluated. A robotic survey system combining a pulsed neutron generator (PNG) and detectors (gamma ray and neutron) can measure the major constituents to a depth of about 30 cm. Scanning mode measurements can give the major elemental concentrations while the rover is moving; analyzing mode measurements can give a detailed elemental analysis of the adjacent material when the rover is stationary. A detailed map of the subsurface elemental concentrations will provide invaluable information relevant to some of the most fundamental astrobiological questions including the presence of water, biogenic activity, life habitability and deposition processes

Bipolar pulse generator for intense pulsed ion beam accelerator

International Nuclear Information System (INIS)

Ito, H.; Igawa, K.; Kitamura, I.; Masugata, K.

2007-01-01

A new type of pulsed ion beam accelerator named ''bipolar pulse accelerator'' (BPA) has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator for the bipolar pulse experiment, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the first experimental result of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PFL, the bipolar pulse with the first (-138 kV, 72 ns) and the second pulse (+130 kV, 70 ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time

Experimental study of electromagnetic radiation from a faster-than-light vacuum macroscopic source

Energy Technology Data Exchange (ETDEWEB)

Bessarab, A.V. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation); Martynenko, S.P. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation); Prudkoi, N.A. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation); Soldatov, A.V. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation)]. E-mail: soldatov@vniief.ru; Terekhin, V.A. [Russian Federal Nuclear Center-All-Russia Scientific Research Institute of Experimental Physics, Sarov, Nizhni Novgorod region, 607188 (Russian Federation)

2006-08-15

The effect which manifests itself in the form of directed electromagnetic pulses (EMP) initiated by an X-ray incident obliquely upon a conducting surface has been confirmed and investigated experimentally in detail. A planar accelerating diode comprising a metallic cathode and grid anode was initiated with an oblique short soft-X-ray pulse from a point laser-plasma source. Then a source of directed EMP-a current of accelerated photoelectrons-was formed whose boundary ran along the anode external surface with a faster-than-light velocity. The plasma was formed when short-pulse ({approx}0.3ns) laser radiation from ISKRA-5 facility was focused on a plane Au target. The amplitude-in-time and spatial characteristics of radiation emitted by the faster-than-light source have been measured. Parameters of the accelerated electron current have been measured too.

Antibodies against PfEMP1, RIFIN, MSP3 and GLURP are acquired during controlled Plasmodium falciparum malaria infections in naïve volunteers

DEFF Research Database (Denmark)

Turner, Louise; Wang, Christian W; Lavstsen, Thomas

2011-01-01

Antibodies to polymorphic antigens expressed during the parasites erythrocytic stages are important mediators of protective immunity against P. falciparum malaria. Therefore, polymorphic blood stage antigens like MSP3, EBA-175 and GLURP and variant surface antigens PfEMP1 and RIFIN are considered...

Structural Studies on Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) Malaria Antigens Using Small Angle X-Ray Scattering (SAXS)

DEFF Research Database (Denmark)

Christoffersen, Stig

Chemistry (App I) [1]. VAR2CSA binds specifically to CSA in the placental tissue of pregnant women hereby causing severe malaria symptoms endangering both mother and child. The minimal VAR2CSA region required to effectively bind CSA was determined to be the N-terminal DBL domain, DBL2X which we locate......Infection with the pathogenic Plasmodium falciparum parasite causes the potentially deadly Malaria disease which leads to over 1 million fatalities each year according to the WHO (World Health Organization). Individuals subjected to multiple infections gradually become immune to the disease...... symptoms and vaccine research is focused on trying to mimic or advance this immune acquisition. Immunity is primarily caused by acquisition of antibodies directed against a family of Plasmodium protein antigens called PfEMP1s located on the surface of infected erythrocytes. The PfEMP1 proteins are adhesive...

A statistical survey of dayside pulsed ionospheric flows as seen by the CUTLASS Finland HF radar

Directory of Open Access Journals (Sweden)

K. A. McWilliams

2000-04-01

Full Text Available Nearly two years of 2-min resolution data and 7- to 21-s resolution data from the CUTLASS Finland HF radar have undergone Fourier analysis in order to study statistically the occurrence rates and repetition frequencies of pulsed ionospheric flows in the noon-sector high-latitude ionosphere. Pulsed ionospheric flow bursts are believed to be the ionospheric footprint of newly reconnected geomagnetic field lines, which occur during episodes of magnetic flux transfer to the terrestrial magnetosphere - flux transfer events or FTEs. The distribution of pulsed ionospheric flows were found to be well grouped in the radar field of view, and to be in the vicinity of the radar signature of the cusp footprint. Two thirds of the pulsed ionospheric flow intervals included in the statistical study occurred when the interplanetary magnetic field had a southward component, supporting the hypothesis that pulsed ionospheric flows are a reconnection-related phenomenon. The occurrence rate of the pulsed ionospheric flow fluctuation period was independent of the radar scan mode. The statistical results obtained from the radar data are compared to occurrence rates and repetition frequencies of FTEs derived from spacecraft data near the magnetopause reconnection region, and to ground-based optical measurements of poleward moving auroral forms. The distributions obtained by the various instruments in different regions of the magnetosphere were remarkably similar. The radar, therefore, appears to give an unbiased sample of magnetopause activity in its routine observations of the cusp footprint.Key words: Magnetospheric physics (magnetosphere-ionosphere interactions; plasma convection; solar wind-magnetosphere interactions

Organização de Reparo na Conversa Cotidiana: um Estudo Empírico

Directory of Open Access Journals (Sweden)

Caroline Caputo Pires

2017-02-01

Full Text Available O presente trabalho visa analisar ocorrências de trajetórias de reparo com dados em fala-em-interação em uma filmagem com quatro brasileiros intercambistas na Alemanha, no qual apresentam suas experiências no período de um ano em contato com outra língua e cultural. Assim, para descrever o fenômeno de reparo (SIDNELL, 2010, GARCEZ, 2008, LODER, 2005 é importante destacar que os participantes em interação e demonstrável pela articulação de análises comunicacionais, o fenômeno do reparo é importante para a interpretação em relação à correção na fala-em-interação, na medida em que o reparo se refere às práticas que participantes usam para contornar problemas ou obstáculos na fala, audição ou compreensão da fala. Enfatiza-se, nesse trabalho, que os estudos sobre reparo na fala-em-interação se deram no campo dos estudos da Análise da Conversa, entre estudiosos que se interessam nas ações cotidianas na vida das pessoas. Dessa forma, a base empírica desse trabalho focalizará os conceitos da Análise da Conversa, fenômenos de reparo em uma filmagem de uma interação de brasileiros em intercambio no ano de 2014. Os dados empíricos fazem parte do projeto da UFMG que investiga perspectivas comunicativas e as atitudes extracomunicativas que indivíduos realizam e desenvolvem no decorrer de um encontro intercultural de duração maior.

Pulse on pulse: modulation and signification in Rafael Lozano-Hemmer's Pulse Room

Directory of Open Access Journals (Sweden)

Merete Carlson

2012-06-01

Full Text Available This article investigates the relation between signifying processes and non-signifying material dynamism in the installation Pulse Room (2006 by Mexican Canadian artist Rafael Lozano-Hemmer. In Pulse Room the sense of pulse is ambiguous. Biorhythms are transmitted from the pulsing energy of the visitor's beating heart to the flashing of a fragile light bulb, thereby transforming each light bulb into a register of individual life. But at the same time the flashing light bulbs together produce a chaotically flickering light environment composed by various layers of repetitive rhythms, a vibrant and pulsating “room”. Hence, the visitor in Pulse Room is invited into a complex scenario that continuously oscillates between various aspects of signification (the light bulbs representing individual lives; the pulse itself as the symbolic “rhythm of life” and instants of pure material processuality (flickering light bulbs; polyrhythmic layers. Taking our point of departure in a discussion of Gilles Deleuze's concepts of modulation and signaletic material in relation to electronic media, we examine how the complex orchestration of pulsation between signification and material modulation produces a multilayered sense of time and space that is central to the sensory experience of Pulse Room as a whole. Pulse Room is, at the very same time, a relational subject–object intimacy and an all-encompassing immersive environment modulating continuously in real space-time.

Implications of Network Centric Warfare

National Research Council Canada - National Science Library

Bailey, Alvin

2004-01-01

.... These areas of dependence also provide numerous vulnerabilities. This paper will focus specifically on Network Centric Warfare's vulnerabilities in terms of sensors cyberterrorism/ Electro-Magnetic Pulse (EMP...

Responsabilidad Social Corporativa de la Empresas de Distribución Comercial Españolas. Evidencias Empíricas

OpenAIRE

Díaz Heredia, Isabel

2013-01-01

En este Trabajo Fin de Máster se analiza la Responsabilidad Social Corporativa de las grandes empresas de distribución comercial en España. En él se trata el desarrollo teórico de la RSC, el sector de la distribución comercial y, por último, se realiza un estudio empírico para el análisis del grado de RSC on-line en las grandes empresas de distribución comercial.

Ayudas públicas a la innovación: una evidencia empírica de la PYME industrial del sureste mexicano

Directory of Open Access Journals (Sweden)

Gabriel Góngora-Biachi

2009-08-01

Full Text Available Este trabajo tiene como propósito estudiar la existencia de tres tipos de sesgo en el proceso de solicitud y concesión de ayudas a la innovación a la PYME industrial en México (sesgo de motivación, sesgo de selección administrativa y sesgo de información. Para ello se realiza un estudio empírico sobre 169 PYME industriales, subvencionadas y no subvencionadas. Los datos del estudio empírico han sido recogidos a través de un cuestionario dirigido al gerente de la empresa. Los resultados muestran que las empresas que solicitan ayudas públicas cuentan con una mejor tecnología. Las empresas elegidas por la Administración para otorgar las ayudas tienen tecnología fuerte-buena, estrategia exploradora-analizadora y una mayor proporción de exportaciones. Finalmente se obtiene, al analizar el sesgo de información en las empresas que no solicitan ayudas, que las mejor informadas se caracterizan por tener un mayor grado de exportación y ser más antiguas.

Evidencia Empírica sobre la Paridad del Poder Adquisitivo en México Evidencia Empírica sobre la Paridad del Poder Adquisitivo en México

Directory of Open Access Journals (Sweden)

Lorena Medina

2012-02-01

Full Text Available This article describes the application of methods recently developed for testing stationarity in the Mexico/US real exchange rate, while allowing for an unknown number of structural breaks in the long-run level of the series. In our empirical implementation, inference relies on bootstraped critical values. As a result, we present unambiguous empirical evidence on the stationarity of the real exchange rate, thus favoring long-run purchasing power parity. En este artículo se describe la aplicación de métodos recientes para probar la estacionariedad del tipo de cambio real peso/dólar, tomando en cuenta la presencia de un número desconocido de cambios estructurales en el nivel de largo plazo de la serie. En nuestra implementación empírica, la inferencia se basa en valores críticos fundamentados en técnicas de remuestreo. Se presenta evidencia contundente sobre la estacionariedad del tipo de cambio real, apoyando así la hipótesis de la paridad del poder adquisitivo.

Determinantes de la equidad en el financiamiento de los medicamentos en Argentina: un estudio empírico

OpenAIRE

Dondo, Mariana; Monsalvo, Mauricio; Garibaldi, Lucas A.

2016-01-01

Resumen Los medicamentos constituyen un alto porcentaje del gasto en salud de los hogares, por eso, tener un sistema progresivo de financiamiento de medicamentos es fundamental para lograr un sistema de salud equitativo. Se ha propuesto que los determinantes de la equidad en el financiamiento son socioeconómicos, demográficos y asociados a la intervención pública, sin embargo, se ha avanzado poco en su evaluación empírica y en la cuantificación de su importancia relativa. En este trabajo esti...

Límites de las formas organizacionales hibridas: Evaluación teórica y análisis de investigaciones empíricas

Directory of Open Access Journals (Sweden)

Maria Valentina Locher

2017-01-01

Full Text Available El concepto de formas organizacionales híbridas resulta clave para las investigaciones empíricas realizadas en el marco de la Nueva Economía Institucional. Las formas híbridas suelen considerarse un avance de dicho programa, sin embargo, aquí se argumentará lo contrario: este concepto evidencia limitaciones en las hipótesis fundamentales de aquel programa de investigaciones económicas. En este trabajo se muestra cómo el concepto de formas híbridas es utilizado para interpretar una realidad socioeconómica que desborda los límites de las formas mercantiles de coordinación económica. Luego se mostrará que ello, en el marco de la Nueva Economía Institucional, supone una paradoja insalvable. Finalmente se ensayan nuevas hipótesis para superar esta limitación y se muestran las consecuencias de este problema sobre dos investigaciones empíricas que desbordaron los límites de las formas organizacionales hibridas.

Environmental management plan (EMP) for Melamchi water supply project, Nepal.

Science.gov (United States)

Khadka, Ram B; Khanal, Anil B

2008-11-01

More than 1.5 million people live in the Kathmandu valley. The valley is facing an extreme shortage of water supply. At the same time the demand is escalating rapidly. To address this issue of scarcity of water, the government of Nepal has proposed a project of inter-basin transfer of water from Melamchi River located 40 km north-east of the Kathmandu valley. The project will cover two districts and three municipalities and will potentially have significant impacts on the environment. In accordance with the Environmental Protection Regulation of Nepal (1997), the Melamchi Water Supply Project (MWSP) has undergone an EIA during the feasibility study stage of the proposed project. The recommendations contained in the EIA were integrated into the project design for implementation in 2006. This paper summarizes the background of MWSP, the environmental concerns described in the EIA and the status of Environmental Management Plan (EMP) developed to address environmental compliance and other issues involving participation and support of the local people. This paper also provides some lessons to learn on the modalities of addressing the demands and grievances of the local people concerning environmental management.

Short-pulse optical parametric chirped-pulse amplification for the generation of high-power few-cycle pulses

International Nuclear Information System (INIS)

Major, Zs.; Osterhoff, J.; Hoerlein, R.; Karsch, S.; Fuoloep, J.A.; Krausz, F.; Ludwig-Maximilians Universitaet, Muenchen

2006-01-01

Complete test of publication follows. In the quest for a way to generate ultrashort, high-power, few-cycle laser pulses the discovery of optical parametric amplification (OPA) has opened up to the path towards a completely new regime, well beyond that of conventional laser amplification technology. The main advantage of this parametric amplification process is that it allows for an extremely broad amplification bandwidth compared to any known laser amplifier medium. When combined with the chirped-pulse amplification (CPA) principle (i.e. OPCPA), on one hand pulses of just 10 fs duration and 8 mJ pulse energy have been demonstrated. On the other hand, pulse energies of up to 30 J were also achieved on a different OPCPA system; the pulse duration in this case, however, was 100 fs. In order to combine ultrashort pulse durations (i.e. pulses in the few-cycle regime) with high pulse energies (i.e. in the Joule range) we propose tu pump on OPCPA chain with TW-scale short pulses (100 fs - 1 ps instead of > 100 ps of previous OPCPA systems) delivered by a conventional CPA system. This approach inherently improves the conditions for generating high-power ultrashort pulses using OPCPA in the following ways. Firstly, the short pump pulse duration reduces the necessary stretching factor for the seed pulse, thereby increasing stretching and compression fidelity. Secondly, also due to the shortened pump pulse duration, a much higher contrast is achieved. Finally, the significantly increased pump power makes the use of thinner OPCPA crystals possible, which implies an even broader amplification bandwidth, thereby allowing for even shorter pulses. We carried out theoretical investigations to show the feasibility of such a set-up. Alongside these studies we will also present preliminary experimental results of an OPCPA system pumped by the output of our Ti:Sapphire ATLAS laser, currently delivering 350 mJ in 43 fs. An insight into the planned scaling of this technique to petawatt

Pulsed electron beam generation with fast repetitive double pulse system

Energy Technology Data Exchange (ETDEWEB)

Sharma, Surender Kumar; Deb, Pankaj; Shyam, Anurag, E-mail: surender80@gmail.com [Energetics and Electromagnetics Division, Bhabha Atomic Research Centre, Visakhapatnam (India); Sharma, Archana [Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Mumbai (India)

2014-07-01

Longer duration high voltage pulse (∼ 100 kV, 260 ns) is generated and reported using helical pulse forming line in compact geometry. The transmission line characteristics of the helical pulse forming line are also used to develop fast repetition double pulse system with very short inter pulse interval. It overcomes the limitations caused due to circuit parameters, power supplies and load characteristics for fast repetitive high voltage pulse generation. The high voltage double pulse of 100 kV, 100 ns with an inter pulse repetition interval of 30 ns is applied across the vacuum field emission diode for pulsed electron beam generation. The electron beam is generated from cathode material by application of negative high voltage (> 100 kV) across the diode by explosive electron emission process. The vacuum field emission diode is made of 40 mm diameter graphite cathode and SS mesh anode. The anode cathode gap was 6 mm and the drift tube diameter was 10 cm. The initial experimental results of pulsed electron beam generation with fast repetitive double pulse system are reported and discussed. (author)

Pulse Distortion in Saturated Fiber Optical Parametric Chirped Pulse Amplification

DEFF Research Database (Denmark)

Lali-Dastjerdi, Zohreh; Da Ros, Francesco; Rottwitt, Karsten

2012-01-01

Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation.......Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation....

Parametric performance predictions for high-power pulsed electric CO lasers

International Nuclear Information System (INIS)

Center, R.E.; Caledonia, G.E.

1975-01-01

A kinetic model of the pulsed electrical CO laser is used to survey the time-dependent laser performance on parameters such as gas mixture, initial translational temperature, and discharge pulse length for both multiline and selected-line operation. Predictions are presented for the total output efficiency, spectral distributions of the stimulated transitions, energy partitioning in the vibrational and translational modes, and the translational temperature history in CO-N 2 mixtures. A brief description of the kinetic model is included. Simple scaling relationships are presented which can be used to scale the results to other densities in the pressure-broadened regime

Evaluación de un modelo de la brdf a partir de simulaciones con modelos semi-empíricos lineales (sel

Directory of Open Access Journals (Sweden)

Edgardo Rafael Medrano Ruedaflores

2013-07-01

Full Text Available Los modelos semi-empíricos lineales, también conocidos como modelos lineales basados en kernels, han sido utilizados con relativo éxito en la derivación de parámetros biofísicos de la vegetación a partir de imágenes satelitales. Su construcción se basa en hipótesis difíciles de corroborar y su calibración demanda suponer condiciones de homogeneidad en el sistema suelo-vegetación-atmósfera. Un modelo de la BRDF libre de estas limitaciones es evaluado en este estudio simulando el proceso de dispersión de la radiación solar según diferentes configuraciones de cobertura terrestre. Los datos fueron generados mediante la implementación de cuatro modelos lineales basados en kernels. Se evaluó el ajuste del modelo en cada escenario simulado a través de regresión lineal simple, obteniéndose valores del coeficiente de determinación superiores a 0.98. Los resultados sugieren que es posible utilizar el modelo evaluado en aplicaciones donde actualmente se emplean modelos semi-empíricos lineales.

Derivation of pulse height to exposure rate conversion functions for aerial radiological surveys

International Nuclear Information System (INIS)

Artuso, J.F.

1985-01-01

A method is described for deriving conversion functions that can be used to convert pulse height spectra taken at altitude to the exposure rate at the 1-m level. An integral equation is set up which involves the integration of a calculated pulse height spectrum multiplied by an unknown conversion function and then set equal to the exposure rate at ground level. This equation is then solved for the conversion function by assuming as a solution a three-term polynomial. Conversion functions have been derived for various source distributions, including surface, uniform, and exponentially distributed sources. These conversion functions are independent of source energy, which means that a conversion can be made without any knowledge of the isotopic content of the source. In the case of a uniform distribution, these conversion functions provide conversions that agree to within 10% with ground truth measurements

Updating the induction module from single-pulse to double-pulses

International Nuclear Information System (INIS)

Huang Ziping; Wang Huacen; Deng Jianjun

2002-01-01

A double-pulse Linear Induced Accelerator (LIA) module is reconstructed based on a usual simple-pulse LIA module. By changing the length of one of the cables between the inductive cell and the Blumlein pulse forming line, two induction pulses with 90 ns FWHM and 150 kV pulse voltage are generated by the ferrite cores inductive cell. The interval time of the pulses is adjustable by changing the lengths of the cable

Evaluation of bipolar pulse generator for high-purity pulsed ion beam

International Nuclear Information System (INIS)

Ito, H.; Kitamura, I.; Masugata, K.

2008-01-01

A new type of pulsed ion beam accelerator named 'bipolar pulse accelerator (BPA)' has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the experimental results of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PEL, the bipolar pulse with the first (-138 kV, 72 ns) and the second pulse (+130 kV, 70 ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time. At present the bipolar pulse generator is installed in the B y type magnetically insulated ion diode and we carry out the experiment on the production of an intense pulsed ion beam by the bipolar pulse accelerator. (author)

Pulse-shaping strategies in short-pulse fiber amplifiers

Energy Technology Data Exchange (ETDEWEB)

Schimpf, Damian Nikolaus

2010-02-09

Ultrashort pulse lasers are an important tool in scientific and industrial applications. However, many applications are demanding higher average powers from these ultrashort pulse sources. This can be achieved by combining direct diode pumping with novel gain media designs. In particular, ultrashort pulse fiber lasers are now delivering average powers in the kW range. However, the design of fiber lasers, producing pulses with high peak-powers, is challenging due to the impact of nonlinear effects. To significantly reduce these detrimental effects in ultrashort pulse fiber amplifers, the combination of chirped pulse amplification (CPA) and large mode area fibers is employed. Using these methods, the pulse energy of fiber lasers has been steadily increasing for the past few years. Recently, a fiber-based CPA-system has been demonstrated which produces pulse energies of around 1 mJ. However, both the stretching and the enlargement of the mode area are limited, and therefore, the impact of nonlinearity is still noticed in systems employing such devices. The aim of this thesis is the analysis of CPA-systems operated beyond the conventional nonlinear limit, which corresponds to accumulated nonlinear phase-shifts around 1 rad. This includes a detailed discussion of the influence of the nonlinear effect self-phase modulation on the output pulse of CPA-systems. An analytical model is presented. Emphasis is placed on the design of novel concepts to control the impact of self-phase modulation. Pulse-shaping is regarded as a powerful tool to accomplish this goal. Novel methods to control the impact of SPM are experimentally demonstrated. The design of these concepts is based on the theoretical findings. Both amplitude- and phase-shaping are studied. Model-based phase-shaping is implemented in a state-of-the-art fiber CPA-system. The influence of the polarization state is also highlighted. Additionally, existing techniques and recent advances are put into context. (orig.)

Pulse-shaping strategies in short-pulse fiber amplifiers

International Nuclear Information System (INIS)

Schimpf, Damian Nikolaus

2010-01-01

Ultrashort pulse lasers are an important tool in scientific and industrial applications. However, many applications are demanding higher average powers from these ultrashort pulse sources. This can be achieved by combining direct diode pumping with novel gain media designs. In particular, ultrashort pulse fiber lasers are now delivering average powers in the kW range. However, the design of fiber lasers, producing pulses with high peak-powers, is challenging due to the impact of nonlinear effects. To significantly reduce these detrimental effects in ultrashort pulse fiber amplifers, the combination of chirped pulse amplification (CPA) and large mode area fibers is employed. Using these methods, the pulse energy of fiber lasers has been steadily increasing for the past few years. Recently, a fiber-based CPA-system has been demonstrated which produces pulse energies of around 1 mJ. However, both the stretching and the enlargement of the mode area are limited, and therefore, the impact of nonlinearity is still noticed in systems employing such devices. The aim of this thesis is the analysis of CPA-systems operated beyond the conventional nonlinear limit, which corresponds to accumulated nonlinear phase-shifts around 1 rad. This includes a detailed discussion of the influence of the nonlinear effect self-phase modulation on the output pulse of CPA-systems. An analytical model is presented. Emphasis is placed on the design of novel concepts to control the impact of self-phase modulation. Pulse-shaping is regarded as a powerful tool to accomplish this goal. Novel methods to control the impact of SPM are experimentally demonstrated. The design of these concepts is based on the theoretical findings. Both amplitude- and phase-shaping are studied. Model-based phase-shaping is implemented in a state-of-the-art fiber CPA-system. The influence of the polarization state is also highlighted. Additionally, existing techniques and recent advances are put into context. (orig.)

Pulse Generator

Science.gov (United States)

Greer, Lawrence (Inventor)

2017-01-01

An apparatus and a computer-implemented method for generating pulses synchronized to a rising edge of a tachometer signal from rotating machinery are disclosed. For example, in one embodiment, a pulse state machine may be configured to generate a plurality of pulses, and a period state machine may be configured to determine a period for each of the plurality of pulses.

Geomagnetic oriented electromagnetic radiation in the ionosphere

International Nuclear Information System (INIS)

Benton, C.U.; Fowles, H.M.; Goen, P.K.

1976-08-01

Strong bursts of electromagnetic radiation were observed in the ionosphere during the Waso rocket Electromagnetic Pulse (EMP) experiment. The pulses have a frequency content from below 20 MHz to above 70 MHz. They vary in duration between 5 μs and 2 ms and in peak-amplitudes of 2 mV/m to greater than 200 mV/m. These pulses show a high degree of geomagnetic correlation and are of unknown origin

Pulsed water jet generated by pulse multiplication

Czech Academy of Sciences Publication Activity Database

Dvorský, R.; Sitek, Libor; Sochor, T.

2016-01-01

Roč. 23, č. 4 (2016), s. 959-967 ISSN 1330-3651 R&D Projects: GA MŠk(CZ) LO1406; GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : high- pressure pulses * pulse intensifier * pulsed water jet * water hammer effect Subject RIV: JQ - Machines ; Tools Impact factor: 0.723, year: 2016 http://hrcak.srce.hr/163752?lang=en

Work family balance : mito ou aptidão : estudo empírico sobre antecedentes e consequências

OpenAIRE

Pedro, Ana Margarida Alexandre

2016-01-01

Dissertação de mestrado em Marketing, apresentada à Faculdade de Economia da Universidade de Coimbra, sob a orientação de Arnaldo Fernandes Matos Coelho e Joaquim Luís Medeiros Alcoforado. “Work Family Balance – Mito ou Aptidão? Estudo Empírico Sobre Antecedentes e Consequências” visa contribuir, com base na revisão bibliográfica, para a compreensão de quais as variáveis que contribuem para esse equilíbrio dinâmico e quais as repercussões. Este tema insere-se no Marketing Inter...

Effect of backmixing on pulse column performance

International Nuclear Information System (INIS)

Miao, Y.W.

1979-05-01

A critical survey of the published literature concerning dispersed phase holdup and longitudinal mixing in pulsed sieve-plate extraction columns has been made to assess the present state-of-the-art in predicting these two parameters, both of which are of critical importance in the development of an accurate mathematical model of the pulse column. Although there are many conflicting correlations of these variables as a function of column geometry, operating conditions, and physical properties of the liquid systems involved it has been possible to develop new correlations which appear to be useful and which are consistent with much of the available data over the limited range of variables most likely to be encountered in plant sized equipment. The correlations developed were used in a stagewise model of the pulse column to predict product concentrations, solute inventory, and concentration profiles in a column for which limited experimental data were available. Reasonable agreement was obtained between the mathematical model and the experimental data. Complete agreement, however, can only be obtained after a correlation for the extraction efficiency has been developed. The correlation of extraction efficiency was beyond the scope of this work

Pulsed TRIGA reactor as substitute for long pulse spallation neutron source

International Nuclear Information System (INIS)

Whittemore, W.L.

1999-01-01

TRIGA reactor cores have been used to demonstrate various pulsing applications. The TRIGA reactor fuel (U-ZrH x ) is very robust especially in pulsing applications. The features required to produce 50 pulses per second have been successfully demonstrated individually, including pulse tests with small diameter fuel rods. A partially optimized core has been evaluated for pulses at 50 Hz with peak pulsed power up to 100 MW and an average power up to 10 MW. Depending on the design, the full width at half power of the individual pulses can range between 2000 μsec to 3000 μsec. Until recently, the relatively long pulses (2000 μsec to 3000 μsec) from a pulsed thermal reactor or a long pulse spallation source (LPSS) have been considered unsuitable for time-of-flight measurements of neutron scattering. More recently considerable attention has been devoted to evaluating the performance of long pulse (1000 to 4000 μs) spallation sources for the same type of neutron measurements originally performed only with short pulses from spallation sources (SPSS). Adequate information is available to permit meaningful comparisons between CW, SPSS, and LPSS neutron sources. Except where extremely high resolution is required (fraction of a percent), which does require short pulses, it is demonstrated that the LPSS source with a 1000 msec or longer pulse length and a repetition rate of 50 to 60 Hz gives results comparable to those from the 60 MW ILL (CW) source. For many of these applications the shorter pulse is not necessarily a disadvantage, but it is not an advantage over the long pulse system. In one study, the conclusion is that a 5 MW 2000 μsec LPSS source improves the capability for structural biology studies of macromolecules by at least a factor of 5 over that achievable with a high flux reactor. Recent studies have identified the advantages and usefulness of long pulse neutron sources. It is evident that the multiple pulse TRIGA reactor can produce pulses comparable to

Method for pulse to pulse dose reproducibility applied to electron linear accelerators

International Nuclear Information System (INIS)

Ighigeanu, D.; Martin, D.; Oproiu, C.; Cirstea, E.; Craciun, G.

2002-01-01

An original method for obtaining programmed beam single shots and pulse trains with programmed pulse number, pulse repetition frequency, pulse duration and pulse dose is presented. It is particularly useful for automatic control of absorbed dose rate level, irradiation process control as well as in pulse radiolysis studies, single pulse dose measurement or for research experiments where pulse-to-pulse dose reproducibility is required. This method is applied to the electron linear accelerators, ALIN-10 of 6.23 MeV and 82 W and ALID-7, of 5.5 MeV and 670 W, built in NILPRP. In order to implement this method, the accelerator triggering system (ATS) consists of two branches: the gun branch and the magnetron branch. ATS, which synchronizes all the system units, delivers trigger pulses at a programmed repetition rate (up to 250 pulses/s) to the gun (80 kV, 10 A and 4 ms) and magnetron (45 kV, 100 A, and 4 ms).The accelerated electron beam existence is determined by the electron gun and magnetron pulses overlapping. The method consists in controlling the overlapping of pulses in order to deliver the beam in the desired sequence. This control is implemented by a discrete pulse position modulation of gun and/or magnetron pulses. The instabilities of the gun and magnetron transient regimes are avoided by operating the accelerator with no accelerated beam for a certain time. At the operator 'beam start' command, the ATS controls electron gun and magnetron pulses overlapping and the linac beam is generated. The pulse-to-pulse absorbed dose variation is thus considerably reduced. Programmed absorbed dose, irradiation time, beam pulse number or other external events may interrupt the coincidence between the gun and magnetron pulses. Slow absorbed dose variation is compensated by the control of the pulse duration and repetition frequency. Two methods are reported in the electron linear accelerators' development for obtaining the pulse to pulse dose reproducibility: the method

Surgeons’ and Emergency Physicians’ Perceptions of Trauma Management and Training

Directory of Open Access Journals (Sweden)

Hemphill, Robin R

2009-08-01

Full Text Available Objective: The study objective was to determine whether surgeons and emergency medicine physicians (EMPs have differing opinions on trauma residency training and trauma management in clinical practice.Methods: A survey was mailed to 250 EMPs and 250 surgeons randomly selected.Results: Fifty percent of surgeons perceived that surgery exclusively managed trauma compared to 27% of EMPs. Surgeons were more likely to feel that only surgeons should manage trauma on presentation to the ED. However, only 60% of surgeons currently felt comfortable with caring for the trauma patient, compared to 84% of EMPs. Compared to EMPs, surgeons are less likely to feel that EMPs can initially manage the trauma patient (71% of surgeons vs. 92% of EMPs.Conclusion: EMPs are comfortable managing trauma while many surgeons do not feel comfortable with the complex trauma patient although the majority of surgeons responded that surgeons should manage the trauma.[WestJEM. 2009;10:144-149.

Narrowband pulse-enhanced upconversion of chirped broadband pulses

International Nuclear Information System (INIS)

Zhao, Kun; Yuan, Peng; Zhong, Haizhe; Zhang, Dongfang; Zhu, Heyuan; Qian, Liejia; Chen, Liezun; Wen, Shuangchun

2010-01-01

We propose and demonstrate an efficient sum-frequency mixing scheme based on narrowband and chirped broadband pulses. It combines the advantages of wider spectral acceptance bandwidth and of alleviating the temporal walk-off, which are both beneficial to higher conversion efficiency. Chirped sum-frequency pulses at 455 nm with energy up to 360 µJ, corresponding to a conversion efficiency of ∼ 40%, are obtained and the pulses can be compressed to ∼ 110 fs. The sum-frequency mixing scheme may provide a promising route to the efficient generation of deep-ultraviolet femtosecond pulses

Survey of simulation methods for modeling pulsed sieve-plate extraction columns

International Nuclear Information System (INIS)

Burkhart, L.

1979-03-01

The report first considers briefly the use of liquid-liquid extraction in nuclear fuel reprocessing and then describes the operation of the pulse column. Currently available simulation models of the column are reviewed, and followed by an analysis of the information presently available from which the necessary parameters can be obtained for use in a model of the column. Finally, overall conclusions are given regarding the information needed to develop an accurate model of the column for materials accountability in fuel reprocessing plants. 156 references

A Novel Domain Cassette Identifies Plasmodium falciparum PfEMP1 Proteins Binding ICAM-1 and Is a Target of Cross-Reactive, Adhesion-Inhibitory Antibodies

DEFF Research Database (Denmark)

Bengtsson, Anja; Jørgensen, Louise; Rask, Thomas Salhøj

2013-01-01

Cerebral Plasmodium falciparum malaria is characterized by adhesion of infected erythrocytes (IEs) to the cerebral microvasculature. This has been linked to parasites expressing the structurally related group A subset of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family of IE...... to ICAM-1. The ICAM-1-binding capacity of DC4 was mapped to the C-terminal third of its Duffy-binding-like beta 3 domain. DC4 was the target of broadly cross-reactive and adhesion-inhibitory IgG Abs, and levels of DC4-specific and adhesion-inhibitory IgG increased with age among P. falciparum......-exposed children. Our study challenges earlier conclusions that group A PfEMP1 proteins are not central to ICAM-1-specific IE adhesion and support the feasibility of developing a vaccine preventing cerebral malaria by inhibiting cerebral IE sequestration. The Journal of Immunology, 2013, 190: 240-249....

International Year of Pulses 2016 | 2016 International Year of Pulses

Science.gov (United States)

the Year in collaboration with Governments, relevant organizations, non-governmental organizations and the composition of pulses Image 4 Wrapping up the International Year of Pulses The 5 key messages to food security Infographic Pulses and climate change International Year of Pulses 2016 The 68th UN

Programmable pulse generator

International Nuclear Information System (INIS)

Xue Zhihua; Lou Binqiao; Duan Xiaohui

2002-01-01

The author introduces the design of programmable pulse generator that is based on a micro-controller and controlled by RS232 interface of personal computer. The whole system has good stability. The pulse generator can produce TTL pulse and analog pulse. The pulse frequency can be selected by EPLD. The voltage amplitude and pulse width of analog pulse can be adjusted by analog switches and digitally-controlled potentiometers. The software development tools of computer is National Instruments LabView5.1. The front panel of this virtual instrumentation is intuitive and easy-to-use. Parameters can be selected and changed conveniently by knob and slide

Effects of pulse-to-pulse residual species on discharges in repetitively pulsed discharges through packed bed reactors

Science.gov (United States)

Kruszelnicki, Juliusz; Engeling, Kenneth W.; Foster, John E.; Kushner, Mark J.

2016-09-01

Atmospheric pressure dielectric barrier discharges (DBDs) sustained in packed bed reactors (PBRs) are being investigated for conversion of toxic and waste gases, and CO2 removal. These discharges are repetitively pulsed having varying flow rates and internal geometries, which results in species from the prior pulse still being in the discharge zone at the time the following discharge pulse occurs. A non-negligible residual plasma density remains, which effectively acts as preionization. This residual charge changes the discharge properties of subsequent pulses, and may impact important PBR properties such as chemical selectivity. Similarly, the residual neutral reactive species produced during earlier pulses will impact the reaction rates on subsequent pulses. We report on results of a computational investigation of a 2D PBR using the plasma hydrodynamics simulator nonPDPSIM. Results will be discussed for air flowing though an array of dielectric rods at atmospheric pressure. The effects of inter-pulse residual species on PBR discharges will be quantified. Means of controlling the presence of residual species in the reactor through gas flow rate, pulse repetition, pulse width and geometry will be described. Comparisons will be made to experiments. Work supported by US DOE Office of Fusion Energy Science and the National Science Foundation.

Antibodies to ICAM1-binding PfEMP1-DBLβ are biomarkers of protective immunity to malaria in a cohort of young children from Papua New Guinea

DEFF Research Database (Denmark)

Tessema, Sofonias K; Utama, Digjaya; Chesnokov, Olga

2018-01-01

Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) mediates parasite sequestration to the cerebral microvasculature via binding of DBLβ domains to Intercellular Adhesion Molecule 1 (ICAM1) and is associated with severe cerebral malaria. In a cohort of 187 young children from Papua New ...

Determinantes de la inversión en I+D: un análisis empírico en empresas europeas de software y servicios informáticos

OpenAIRE

Fernández López, Javier

2013-01-01

Estudio empírico de los factores determinantes de la inversión en I+D en empresas europeas de software y servicios informáticos entre 2004-2010 Economía Financiera y Contabilidad Máster en Contabilidad y Gestión Financiera

La fuerza de los lazos: una exploración teórica y empírica de sus múltiples significados

Directory of Open Access Journals (Sweden)

Irene Cruz Gómez

2013-01-01

Full Text Available La fuerza del vínculo es una de las características recurrentemente estudiadas en las redes personales. Es un dato aparentemente sencillo de generar, con una potencial capacidad predictiva sobre los intercambios dentro de la relación y de la posición del contacto dentro de la red. Sin embargo, la gran diversidad de indicadores que se emplean en la literatura para medir esta fuerza del vínculo da fe de la vaguedad en la definición del concepto y las consecuentes dificultades para operativizarlo, dando lugar a resultados ambivalentes en su observación empírica. Con este trabajo de revisión teórica, metodológica y empírica se pre- tende ofrecer una base sobre la cual contribuir a la delimitación del concepto. Se propone una dimensionalización teórica de la noción, distinguiendo sus aspectos expresivos, sociales y estructurales, y a continuación se compara el comportamiento de diversos indicadores de las distintas dimensiones empleando una muestra de 441 redes personales y 13.230 relaciones provenientes de una encuesta realizada en Cataluña entre 2009 y 2010.

PfEMP1 – A Parasite Protein Family of Key Importance in Plasmodium falciparum Malaria Immunity and Pathogenesis

DEFF Research Database (Denmark)

Hviid, Lars; Jensen, Anja T R

2015-01-01

to be a central element in the pathogenesis of the disease. It is mediated by the interaction of parasite ligands on the erythrocyte surface and a range of host receptor molecules in many organs and tissues. Among several proteins and protein families implicated in this process, the P. falciparum erythrocyte...... membrane protein 1 (PfEMP1) family of high-molecular weight and highly variable antigens appears to be the most prominent. In this chapter, we aim to provide a systematic overview of the current knowledge about these proteins, their structure, their function, how they are presented on the erythrocyte...

Characteristics of bipolar-pulse generator for intense pulsed heavy ion beam acceleration

International Nuclear Information System (INIS)

Igawa, K.; Tomita, T.; Kitamura, I.; Ito, H.; Masugata, K.

2006-01-01

Intense pulsed heavy ion beams are expected to be applied to the implantation technology for semiconductor materials. In the application it is very important to purify the ion beam. In order to improve the purity of an intense pulsed ion beams we have proposed a new type of pulsed ion beam accelerator named 'bipolar pulse accelerator (BPA)'. A prototype of the experimental system has been developed to perform proof of principle experiments of the accelerator. A bipolar pulse generator has been designed for the generation of the pulsed ion beam with the high purity via the bipolar pulse acceleration and the electrical characteristics of the generator were evaluated. The production of the bipolar pulse has been confirmed experimentally. (author)

Development of the pulse transformer for NLC klystron pulse modulator

International Nuclear Information System (INIS)

Akemoto, M.; Gold, S.; Koontz, R.; Krasnykh, A.

1997-05-01

We have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and core size. After making a tradeoff among these parameters carefully, a conventional pulse transformer with a rise time of 250ns and pulse droop of 3.6% has been designed and built. The transmission characteristics and pulse time-response were measured. The data were compared with the model. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage tests are also presented

Dynamic Characterization of Fiber Optical Chirped Pulse Amplification for Sub-ps Pulses

DEFF Research Database (Denmark)

Cristofori, Valentina; Lali-Dastjerdi, Zohreh; Rishøj, Lars Søgaard

2013-01-01

We investigate experimentally the propagation of sub-picosecond pulses in fiber optical parametric chirped pulse amplifiers, showing a significant broadening of the pulses from 450 fs up to 720 fs due to dispersion and self-phase modulation.......We investigate experimentally the propagation of sub-picosecond pulses in fiber optical parametric chirped pulse amplifiers, showing a significant broadening of the pulses from 450 fs up to 720 fs due to dispersion and self-phase modulation....

Petawatt pulsed-power accelerator

Science.gov (United States)

Stygar, William A.; Cuneo, Michael E.; Headley, Daniel I.; Ives, Harry C.; Ives, legal representative; Berry Cottrell; Leeper, Ramon J.; Mazarakis, Michael G.; Olson, Craig L.; Porter, John L.; Wagoner; Tim C.

2010-03-16

A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

Pulse transformer R and D for NLC klystron pulse modulator

International Nuclear Information System (INIS)

Akemoto, M.; Gold, S.; Krasnykh, A.; Koontz, R.

1997-07-01

The authors have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and requires a larger core size. After making a tradeoff among these parameters carefully, a conventional pulse transformer with a rise time of 250ns and a pulse droop of 3.6% has been designed and built. The transmission characteristics and pulse time-response were measured. The data were compared with the model. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage tests using a klystron load are also presented

Random pulse generator

International Nuclear Information System (INIS)

Guo Ya'nan; Jin Dapeng; Zhao Dixin; Liu Zhen'an; Qiao Qiao; Chinese Academy of Sciences, Beijing

2007-01-01

Due to the randomness of radioactive decay and nuclear reaction, the signals from detectors are random in time. But normal pulse generator generates periodical pulses. To measure the performances of nuclear electronic devices under random inputs, a random generator is necessary. Types of random pulse generator are reviewed, 2 digital random pulse generators are introduced. (authors)

Impacts of Airborne Lidar Pulse Density on Estimating Biomass Stocks and Changes in a Selectively Logged Tropical Forest

Directory of Open Access Journals (Sweden)

Carlos Alberto Silva

2017-10-01

Full Text Available Airborne lidar is a technology well-suited for mapping many forest attributes, including aboveground biomass (AGB stocks and changes in selective logging in tropical forests. However, trade-offs still exist between lidar pulse density and accuracy of AGB estimates. We assessed the impacts of lidar pulse density on the estimation of AGB stocks and changes using airborne lidar and field plot data in a selectively logged tropical forest located near Paragominas, Pará, Brazil. Field-derived AGB was computed at 85 square 50 × 50 m plots in 2014. Lidar data were acquired in 2012 and 2014, and for each dataset the pulse density was subsampled from its original density of 13.8 and 37.5 pulses·m−2 to lower densities of 12, 10, 8, 6, 4, 2, 0.8, 0.6, 0.4 and 0.2 pulses·m−2. For each pulse density dataset, a power-law model was developed to estimate AGB stocks from lidar-derived mean height and corresponding changes between the years 2012 and 2014. We found that AGB change estimates at the plot level were only slightly affected by pulse density. However, at the landscape level we observed differences in estimated AGB change of >20 Mg·ha−1 when pulse density decreased from 12 to 0.2 pulses·m−2. The effects of pulse density were more pronounced in areas of steep slope, especially when the digital terrain models (DTMs used in the lidar derived forest height were created from reduced pulse density data. In particular, when the DTM from high pulse density in 2014 was used to derive the forest height from both years, the effects on forest height and the estimated AGB stock and changes did not exceed 20 Mg·ha−1. The results suggest that AGB change can be monitored in selective logging in tropical forests with reasonable accuracy and low cost with low pulse density lidar surveys if a baseline high-quality DTM is available from at least one lidar survey. We recommend the results of this study to be considered in developing projects and national

Fiber Optical Parametric Chirped Pulse Amplification of Sub-Picosecond Pulses

DEFF Research Database (Denmark)

Cristofori, Valentina; Lali-Dastjerdi, Zohreh; Da Ros, Francesco

2013-01-01

We demonstrate experimentally, for the first time to our knowledge, fiber optical parametric chirped pulse amplification of 400-fs pulses. The 400-fs signal is stretched, amplified by 26 dB and compressed back to 500 fs.......We demonstrate experimentally, for the first time to our knowledge, fiber optical parametric chirped pulse amplification of 400-fs pulses. The 400-fs signal is stretched, amplified by 26 dB and compressed back to 500 fs....

Pulse-to-pulse variations in accreting X-ray pulsars

Directory of Open Access Journals (Sweden)

Kretschmar Peter

2014-01-01

Full Text Available In most accreting X-ray pulsars, the periodic signal is very clear and easily shows up as soon as data covering sufficient pulse periods (a few ten are available. The mean pulse profile is often quite typical for a given source and with minor variations repeated and recognisable across observations done years or even decades apart. At the time scale of individual pulses, significant pulse-to-pulse variations are commonly observed. While at low energies some of these variations might be explained by absorption, in the hard X-rays they will reflect changes in the accretion and subsequent emission. The amount of these variations appears to be quite different between sources and contains information about the surrounding material as well ass possibly interactions at the magnetosphere. We investigate such variations for a sample of well-known sources.

Pulse to pulse klystron diagnosis system

International Nuclear Information System (INIS)

Nowak, J.; Davidson, V.; Genova, L.; Johnson, R.; Reagan, D.

1981-03-01

This report describes a system used to study the behavior of SLAC high powered klystrons operating with a twice normal pulse width of 5 μs. At present, up to eight of the klystrons installed along the accelerator can be operated with long pulses and monitored by this system. The report will also discuss some of the recent findings and investigations

Efficient chirped-pulse amplification of sub-20 fs laser pulses

Energy Technology Data Exchange (ETDEWEB)

Matsuoka, Shinichi; Yamakawa, Koichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

We have developed a model for ultrabroadband and ultrashort pulse amplification including the effects of a pulse shaper for regenerative pulse shaping, gain narrowing and gain saturation in the amplifiers. Thin solid etalons are used to control both gain narrowing and gain saturation during amplification. This model has been used to design an optimized Ti:sapphire amplifier system for producing efficiently pulses of < 20-fs duration with approaching peak and average powers of 100 TW and 20 W. (author)

Patterns of digital volume pulse waveform and pulse transit time in ...

African Journals Online (AJOL)

In this study the digital volume pulse wave and the pulse transit time of the thumb and big toe were analyzed in young and older subjects some of whom were hypertensive. We aimed to study the components and patterns of the pulse waveform and the pulse transit time and how they might change. Material and Methods: ...

Aspectos conceptuales y empíricos de la financiación de nuevas empresas en Colombia Conceptual and empirical aspects of the financing of new companies in Colombia

Directory of Open Access Journals (Sweden)

Bernardo Barona Zuluaga

2010-06-01

Full Text Available Este artículo presenta los resultados de una investigación empírica sobre la utilización de diferentes fuentes de financiación por parte de empresas nuevas en los primeros anos de vida. El principal soporte conceptual del estudio es el paradigma del ciclo de crecimiento financiero desarrollado por Berger y Udell (1998, el cual explica satisfactoriamente los hallazgos encontrados en el componente empírico del estudio aquí presentado, que se basa en una encuesta realizada a 130 empresarios de la Ciudad de Cali (Colombia. Los entrevistados reportaron de manera mayoritaria el uso de recursos propios y de familiares y amigos y la retención de utilidades en los primeros anos de vida de una empresa. Le sigue en importancia a estas fuentes, la financiación provista por establecimientos de crédito; llama la atención la importancia relativa del leasing. Las recomendaciones mas importantes incluyen: fortalecer las fuentes de capital semilla, darle mayor peso en los cursos de finanzas de nivel universitario al estudio de los problemas de las empresas nuevas y MIPYMES, adelantar una reforma financiera que facilite la emisión de acciones y mejorar la cantidad y calidad de información pública disponible sobre la financiación de las empresas objeto de este estudio.This article presents the results of an empirical research on the type of financial resources used by a sample of new enterprises in their early years of life. The main conceptual support of the study is the financial growth cycle paradigm developed by Berger and Udell (1998. This paradigm successfully explains the findings in the empirical component of the study presented here, which is based on a survey of 130 entrepreneurs in the city of Cali, Colombia. The survey results highlighted the importance of the use of financial resources provided by the owner and theirs family and friends, and of the retention of profits in their companies in the early years. Next in importance is the

A 350 KV nanosecond pulse voltage generator with adjustable pulsed-width

International Nuclear Information System (INIS)

Wang, X.; Wang, M.; Chen, Y.Q.; Zeng, L.G.; Han, M.

2002-01-01

This paper presents a 350 kV nanosecond pulse voltage generator (NPVG). The voltage pulsed-width can be adjusted from 30 to 160 ns. The generator consists of: Marx generator, pulsed forming line (PFL), main switch and matched impedance. The output voltage of Marx generator is over than nU c (n- the stage number of Marx generator, U c -the charging voltage of capacitor). When the pulse forming line is terminated with an impedance that is over than the characteristic impedance of PFL, the higher voltage pulse was provided for the load

Pulsed power magnet technology for laser particle acceleration and laser plasma physics - a survey of developments at Helmholtz-Zentrum Dresden-Rossendorf

Energy Technology Data Exchange (ETDEWEB)

Kroll, Florian; Joost, Martin [Helmholtz-Zentrum Dresden-Rossendorf (Germany); TU Dresden (Germany); Burris-Mog, Trevor; Herrmannsdoerfer, Thomas; Kraft, Stephan; Masood, Umar; Schlenvoigt, Hans-Peter; Sobiella, Manfred; Wustmann, Bernd; Zherlitsyn, Sergei; Cowan, Thomas; Schramm, Ulrich [Helmholtz-Zentrum Dresden-Rossendorf (Germany)

2013-07-01

Since the mid-1950s, pulsed high-field magnets have become a common, versatile research tool with application mostly in solid state physics and material research. Recently developed pulsed power magnet technology, specifically designed to meet the demands of laser acceleration and laser plasma experiments, open up new research opportunities: We present a pulsed air core solenoid (up to 20 T) for effective collection and focusing of laser accelerated particles. It could function as a crucial part of a compact, laser-based ion source (pursued by the LIGHT collaboration) or of beam guidance systems. Furthermore, the poster shows a split pair coil, utterly compact and with optical access in between the coil pairs and on axis, to study laser-driven plasma expansion under high magnetic fields (30 T). To power such devices, portable capacitor-based pulse generators have been developed at Helmholtz-Zentrum Dresden-Rossendorf. We present first results of the functional testing of our third-generation pulse generator. Looking forward, we outline a concept for a medical gantry based on pulsed high field beam optics.

Research on the Countermeasures against Electromagnetic Interface in Power Systems

Energy Technology Data Exchange (ETDEWEB)

Lee, Won Bin; Kang, Young Suk; Choi, Hyo Yul; Cha, Ok Hyun [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Lee, Gi Chul; Le, Jae Bok; Ha, Tae Hyun; Kim, Suk Joo; Na, Dae Yul; Kim, Yong Ho; Jeong, Kyo Beom [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

1997-12-31

As the results of widespread use of microelectronics in electric power system, electric environment of power operation facilities in substation has become more weak and severe for surge voltages. Electromagnetic coupled overvoltage caused by HV bus switching operating lead to the malfunction or destruction of low voltage control circuit which mostly used signal. To scope with this transients overvoltage, it is necessary to be investigated transient source and propagation path and analysed its effects to low voltage circuit such as relay. This study is to analysis source of conducted EMP(electromagnetic pulse) on the low voltage control circuit and to acquits transient voltage waveforms, and to provide countermeasures against transient voltage, and EMP filtering method according to each EMP each type. With this, gradual improvement of EMI countermeasure will be achieved. (author). 49 refs., figs.

Research on the Countermeasures against Electromagnetic Interface in Power Systems

Energy Technology Data Exchange (ETDEWEB)

Lee, Won Bin; Kang, Young Suk; Choi, Hyo Yul; Cha, Ok Hyun [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Lee, Gi Chul; Le, Jae Bok; Ha, Tae Hyun; Kim, Suk Joo; Na, Dae Yul; Kim, Yong Ho; Jeong, Kyo Beom [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

1996-12-31

As the results of widespread use of microelectronics in electric power system, electric environment of power operation facilities in substation has become more weak and severe for surge voltages. Electromagnetic coupled overvoltage caused by HV bus switching operating lead to the malfunction or destruction of low voltage control circuit which mostly used signal. To scope with this transients overvoltage, it is necessary to be investigated transient source and propagation path and analysed its effects to low voltage circuit such as relay. This study is to analysis source of conducted EMP(electromagnetic pulse) on the low voltage control circuit and to acquits transient voltage waveforms, and to provide countermeasures against transient voltage, and EMP filtering method according to each EMP each type. With this, gradual improvement of EMI countermeasure will be achieved. (author). 49 refs., figs.

Optical pulse compression

International Nuclear Information System (INIS)

Glass, A.J.

1975-01-01

The interest in using large lasers to achieve a very short and intense pulse for generating fusion plasma has provided a strong impetus to reexamine the possibilities of optical pulse compression at high energy. Pulse compression allows one to generate pulses of long duration (minimizing damage problems) and subsequently compress optical pulses to achieve the short pulse duration required for specific applications. The ideal device for carrying out this program has not been developed. Of the two approaches considered, the Gires--Tournois approach is limited by the fact that the bandwidth and compression are intimately related, so that the group delay dispersion times the square of the bandwidth is about unity for all simple Gires--Tournois interferometers. The Treacy grating pair does not suffer from this limitation, but is inefficient because diffraction generally occurs in several orders and is limited by the problem of optical damage to the grating surfaces themselves. Nonlinear and parametric processes were explored. Some pulse compression was achieved by these techniques; however, they are generally difficult to control and are not very efficient. (U.S.)

Pulse induction heating

Energy Technology Data Exchange (ETDEWEB)

Vasiliev, A S; Kachanov, B Y; Kogan, B V

1993-12-31

Induction heating and three types of pulse processes were studied. It was found that in pulse processes the frequency and pulse duration of heat treatments do not remain constant. High frequency pulse heat treatments can be used on sprayed coatings; such treatments will result in stronger surfaces with no cracks. For induction hardening, the rate of specific power was 1 to 1.5 kW/sq.cm, for forging it was 0.2 to 0.3 kW/sq.cm and for melting it was 0.05 to 0.1 kW/sq.cm. The application of pulse heating will result in higher rates of specific power.

Pulse-shaping mechanism in colliding-pulse mode-locked laser diodes

DEFF Research Database (Denmark)

Bischoff, Svend; Sørensen, Mads Peter; Mørk, J.

1995-01-01

The large signal dynamics of passively colliding pulse mode-locked laser diodes is studied. We derive a model which explains modelocking via the interplay of gain and loss dynamics; no bandwidth limiting element is necessary for pulse formation. It is found necessary to have both fast and slow...... absorber dynamics to achieve mode-locking. Significant chirp is predicted for pulses emitted from long lasers, in agreement with experiment. The pulse width shows a strong dependence on both cavity and saturable absorber length. (C) 1995 American Institute of Physics....

S100 lathe bed pulse generator applied to pulsed nuclear magnetic resonance

International Nuclear Information System (INIS)

Cernicchiaro, G.R.C.; Rudge, M.G.; Albuquerque, M.P.

1989-01-01

The project and construction of four channel pulse generator in the S100 standard plate and its control software for microcomputer are described. The microcomputer has total control on the pulse generator, which has seven programable parameters, defining the position of four pulses and the width for the three first ones. This pulse generator is controlled by a software developed in c language, and is used in pulsed nuclear magnetic resonance experiences. (M.C.K.) [pt

Arduino based radiation survey meter

International Nuclear Information System (INIS)

Rahman, Nur Aira Abd; Lombigit, Lojius; Abdullah, Nor Arymaswati; Azman, Azraf; Dolah, Taufik; Jaafar, Zainudin; Mohamad, Glam Hadzir Patai; Ramli, Abd Aziz Mhd; Zain, Rasif Mohd; Said, Fazila; Khalid, Mohd Ashhar; Taat, Muhamad Zahidee; Muzakkir, Amir

2016-01-01

This paper presents the design of new digital radiation survey meter with LND7121 Geiger Muller tube detector and Atmega328P microcontroller. Development of the survey meter prototype is carried out on Arduino Uno platform. 16-bit Timer1 on the microcontroller is utilized as external pulse counter to produce count per second or CPS measurement. Conversion from CPS to dose rate technique is also performed by Arduino to display results in micro Sievert per hour (μSvhr −1 ). Conversion factor (CF) value for conversion of CPM to μSvhr −1 determined from manufacturer data sheet is compared with CF obtained from calibration procedure. The survey meter measurement results are found to be linear for dose rates below 3500 µSv/hr

Migrações internas: evolução teórica e algumas evidências empíricas para o caso brasileiro

OpenAIRE

Márcia Regina Gabardo Câmara

1988-01-01

The aim of this article is to show new light concerning internal migration in Brazil. Consequently a review of the specialized literature was necessary and here in are presented some empirical evidences concerning its recent development. O objetivo do presente artigo é jogar novas luzes sobre a migração interna no Brasil. Conseqüentemente, foi necessário revisar a literatura especializada e apresentar algumas evidências empíricas sobre o seu desenvolvimento recente

Plasmodium falciparum associated with severe childhood malaria preferentially expresses PfEMP1 encoded by group A var genes

DEFF Research Database (Denmark)

Jensen, Anja T R; Magistrado, Pamela; Sharp, Sarah

2004-01-01

Parasite-encoded variant surface antigens (VSAs) like the var gene-encoded Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family are responsible for antigenic variation and infected red blood cell (RBC) cytoadhesion in P. falciparum malaria. Parasites causing severe malaria in noni...... genes, such as PFD1235w/MAL7P1.1, appear to be involved in the pathogenesis of severe disease and are thus attractive candidates for a vaccine against life-threatening P. falciparum malaria....

Contramedidas em segurança da informação e vulnerabilidade cibernética: evidência empírica de empresas brasileiras

Directory of Open Access Journals (Sweden)

Igor Siqueira Cortez

2013-12-01

Full Text Available Recentemente, uma série de ataques cibernéticos a empresas e governos no Brasil e no exterior tornou público o potencial impacto econômico desse tipo de atividade, do ponto de vista tanto privado quanto público. Existe extensa literatura econômica - teórica e empírica - que avalia os incentivos para que as empresas adotem ou não medidas de segurança da informação. No presente estudo foi desenvolvida uma avaliação empírica desse fenômeno no Brasil. Modelos logit e probit ordenado foram desenvolvidos como forma de avaliar os efeitos sobre a probabilidade de ocorrência de problemas de segurança da informação, levando-se em conta as características das firmas, inclusive as medidas de segurança de informação. Os resultados apontam para uma relação positiva entre as medidas de segurança da informação e a probabilidade de identificar a ocorrência de problemas cibernéticos, sugerindo que a sofisticação dessas medidas de proteção aumenta a probabilidade de identificação dos problemas.

Laser pulse stacking method

Science.gov (United States)

Moses, E.I.

1992-12-01

A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

Controllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping

Science.gov (United States)

Peterchev, Angel V.; DʼOstilio, Kevin; Rothwell, John C.; Murphy, David L.

2014-10-01

Objective. This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach. We present a third generation controllable pulse parameter device (cTMS3) that uses a novel circuit topology with two energy-storage capacitors. It incorporates several implementation and functionality advantages over conventional TMS devices and other devices with advanced pulse shape control. cTMS3 generates lower internal voltage differences and is implemented with transistors with a lower voltage rating than prior cTMS devices. Main results. cTMS3 provides more flexible pulse shaping since the circuit topology allows four coil-voltage levels during a pulse, including approximately zero voltage. The near-zero coil voltage enables snubbing of the ringing at the end of the pulse without the need for a separate active snubber circuit. cTMS3 can generate powerful rapid pulse sequences (\\lt 10 ms inter pulse interval) by increasing the width of each subsequent pulse and utilizing the large capacitor energy storage, allowing the implementation of paradigms such as paired-pulse and quadripulse TMS with a single pulse generation circuit. cTMS3 can also generate theta (50 Hz) burst stimulation with predominantly unidirectional electric field pulses. The cTMS3 device functionality and output strength are illustrated with electrical output measurements as well as a study of the effect of pulse width and polarity on the active motor threshold in ten healthy volunteers. Significance. The cTMS3 features could extend the utility of TMS as a research, diagnostic, and therapeutic tool.

Revisi?n de literatura emp?rica acerca de la relaci?n entre depresi?n y apoyo familiar en personas transg?nero

OpenAIRE

Ruiz Cortes, Estefany Tatiana

2017-01-01

Se realiz? una revisi?n de diferentes trabajos e investigaci?n emp?rica sobre sobre el concepto de g?nero e identidad de g?nero y la conceptualizaci?n del transgenerismo como fen?meno buscando una aproximaci?n de los factores que intervienen en el proceso de socializaci?n y desarrollo psicosocial de las personas transg?nero. La constante discriminaci?n, estigmatizaci?n y segregaci?n social hacen que las personas trans sean vulnerables y que lleguen a presentar niveles de ansiedad, depresi?n y...

Relationships between the use of Embden Meyerhof pathway (EMP) or Phosphoketolase pathway (PKP) and lactate production capabilities of diverse Lactobacillus reuteri strains.

Science.gov (United States)

Burgé, Grégoire; Saulou-Bérion, Claire; Moussa, Marwen; Allais, Florent; Athes, Violaine; Spinnler, Henry-Eric

2015-10-01

The aims of this study is to compare the growth and glucose metabolism of three Lactobacillus reuteri strains (i.e. DSM 20016, DSM 17938, and ATCC 53608) which are lactic acid bacteria of interest used for diverse applications such as probiotics implying the production of biomass, or for the production of valuable chemicals (3-hydroxypropionaldehyde, 3-hydroxypropionic acid, 1,3-propanediol). However, the physiological diversity inside the species, even for basic metabolisms, like its capacity of acidification or glucose metabolism, has not been studied yet. In the present work, the growth and metabolism of three strains representative of the species diversity have been studied in batch mode. The strains were compared through characterization of growth kinetics and evaluation of acidification kinetics, substrate consumption and product formation. The results showed significant differences between the three strains which may be explained, at least in part, by variations in the distribution of carbon source between two glycolytic pathways during the bacterial growth: the phosphoketolase or heterolactic pathway (PKP) and the Embden-Meyerhof pathway (EMP). It was also shown that, in the context of obtaining a large amount of biomass, DSM 20016 and DSM 17938 strains were the most effective in terms of growth kinetics. The DSM 17938 strain, which shows the more significant metabolic shift from EMP to PKP when the pH decreases, is more effective for lactate production.

Determination of residual oil saturation from time-lapse pulsed neutron capture logs in a large sandstone reservoir

International Nuclear Information System (INIS)

Syed, E.V.; Salaita, G.N.; McCaffery, F.G.

1991-01-01

Cased hole logging with pulsed neutron tools finds extensive use for identifying zones of water breakthrough and monitoring oil-water contacts in oil reservoirs being depleted by waterflooding or natural water drive. Results of such surveys then find direct use for planning recompletions and water shutoff treatments. Pulsed neutron capture (PNC) logs are useful for estimating water saturation changes behind casing in the presence of a constant, high-salinity environment. PNC log surveys run at different times, i.e., in a time-lapse mode, are particularly amenable to quantitative analysis. The combined use of the original open hole and PNC time-lapse log information can then provide information on remaining or residual oil saturations in a reservoir. This paper reports analyses of historical pulsed neutron capture log data to assess residual oil saturation in naturally water-swept zones for selected wells from a large sandstone reservoir in the Middle East. Quantitative determination of oil saturations was aided by PNC log information obtained from a series of tests conducted in a new well in the same field

RF Pulsed Heating

Energy Technology Data Exchange (ETDEWEB)

Pritzkau, David P.

2002-01-03

RF pulsed heating is a process by which a metal is heated from magnetic fields on its surface due to high-power pulsed RF. When the thermal stresses induced are larger than the elastic limit, microcracks and surface roughening will occur due to cyclic fatigue. Pulsed heating limits the maximum magnetic field on the surface and through it the maximum achievable accelerating gradient in a normal conducting accelerator structure. An experiment using circularly cylindrical cavities operating in the TE{sub 011} mode at a resonant frequency of 11.424 GHz is designed to study pulsed heating on OFE copper, a material commonly used in normal conducting accelerator structures. The high-power pulsed RF is supplied by an X-band klystron capable of outputting 50 MW, 1.5 {micro}s pulses. The test pieces of the cavity are designed to be removable to allow testing of different materials with different surface preparations. A diagnostic tool is developed to measure the temperature rise in the cavity utilizing the dynamic Q change of the resonant mode due to heating. The diagnostic consists of simultaneously exciting a TE{sub 012} mode to steady-state in the cavity at 18 GHz and measuring the change in reflected power as the cavity is heated from high-power pulsed RF. Two experimental runs were completed. One run was executed at a calculated temperature rise of 120 K for 56 x 10{sup 6} pulses. The second run was executed at a calculated temperature rise of 82 K for 86 x 10{sup 6} pulses. Scanning electron microscope pictures show extensive damage occurring in the region of maximum temperature rise on the surface of the test pieces.

Insect cells are superior to Escherichia coli in producing malaria proteins inducing IgG targeting PfEMP1 on infected erythrocytes

Directory of Open Access Journals (Sweden)

Joergensen Louise

2010-11-01

Full Text Available Abstract Background The PFD1235w Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1 antigen is associated with severe malaria in children and can be expressed on the surface of infected erythrocytes (IE adhering to ICAM1. However, the exact three-dimensional structure of this PfEMP1 and its surface-exposed epitopes are unknown. An insect cell and Escherichia coli based system was used to express single and double domains encoded by the pfd1235w var gene. The resulting recombinant proteins have been evaluated for yield and purity and their ability to induce rat antibodies, which react with the native PFD1235w PfEMP1 antigen expressed on 3D7PFD1235w-IE. Their recognition by human anti-malaria antibodies from previously infected Tanzanian donors was also analysed. Methods The recombinant proteins were run on SDS-PAGE and Western blots for quantification and size estimation. Insect cell and E. coli-produced recombinant proteins were coupled to a bead-based Luminex assay to measure the plasma antibody reactivity of 180 samples collected from Tanzanian individuals. The recombinant proteins used for immunization of rats and antisera were also tested by flow cytometry for their ability to surface label 3D7PFD1235w-IE. Results All seven pAcGP67A constructs were successfully expressed as recombinant protein in baculovirus-infected insect cells and subsequently produced to a purity of 60-97% and a yield of 2-15 mg/L. By comparison, only three of seven pET101/D-TOPO constructs expressed in the E. coli system could be produced at all with purity and yield ranging from 3-95% and 6-11 mg/L. All seven insect cell, but only two of the E. coli produced proteins induced antibodies reactive with native PFD1235w expressed on 3D7PFD1235w-IE. The recombinant proteins were recognized in an age- and transmission intensity-dependent manner by antibodies from 180 Tanzanian individuals in a bead-based Luminex assay. Conclusions The baculovirus based insect cell

Optimal pulse fishing policy in stage-structured models with birth pulses

International Nuclear Information System (INIS)

Gao Shujing; Chen Lansun; Sun Lihua

2005-01-01

In this paper, we propose exploited models with stage structure for the dynamics in a fish population for which periodic birth pulse and pulse fishing occur at different fixed time. Using the stroboscopic map, we obtain an exact cycle of system, and obtain the threshold conditions for its stability. Bifurcation diagrams are constructed with the birth rate (or pulse fishing time or harvesting effort) as the bifurcation parameter, and these are observed to display complex dynamic behaviors, including chaotic bands with period windows, period-doubling, multi-period-halving and incomplete period-doubling bifurcation, pitch-fork and tangent bifurcation, non-unique dynamics (meaning that several attractors or attractor and chaos coexist) and attractor crisis. This suggests that birth pulse and pulse fishing provide a natural period or cyclicity that make the dynamical behaviors more complex. Moreover, we show that the pulse fishing has a strong impact on the persistence of the fish population, on the volume of mature fish stock and on the maximum annual-sustainable yield. An interesting result is obtained that, after the birth pulse, the population can sustain much higher harvesting effort if the mature fish is removed as early as possible

Versatile pulse programmer for pulsed nuclear magnetic resonance spectroscopy

International Nuclear Information System (INIS)

Adduci, D.J.

1979-05-01

A description of the sequence of events and the decisions leading to the design of a versatile pulse programmer for pulsed NMR are presented. Background and application information is discussed in order that the reader might better understand the role of the pulse programmer in a NMR spectrometer. Various other design approaches are presented as a basis for comparison. Specifications for this design are proposed, the hardware implementation of the specifications is discussed, and the software operating system is presented

Versatile pulse programmer for pulsed nuclear magnetic resonance spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Adduci, D.J.

1979-05-01

A description of the sequence of events and the decisions leading to the design of a versatile pulse programmer for pulsed NMR are presented. Background and application information is discussed in order that the reader might better understand the role of the pulse programmer in a NMR spectrometer. Various other design approaches are presented as a basis for comparison. Specifications for this design are proposed, the hardware implementation of the specifications is discussed, and the software operating system is presented.

A compact bipolar pulse-forming network-Marx generator based on pulse transformers.

Science.gov (United States)

Zhang, Huibo; Yang, Jianhua; Lin, Jiajin; Yang, Xiao

2013-11-01

A compact bipolar pulse-forming network (PFN)-Marx generator based on pulse transformers is presented in this paper. The high-voltage generator consisted of two sets of pulse transformers, 6 stages of PFNs with ceramic capacitors, a switch unit, and a matched load. The design is characterized by the bipolar pulse charging scheme and the compact structure of the PFN-Marx. The scheme of bipolar charging by pulse transformers increased the withstand voltage of the ceramic capacitors in the PFNs and decreased the number of the gas gap switches. The compact structure of the PFN-Marx was aimed at reducing the parasitic inductance in the generator. When the charging voltage on the PFNs was 35 kV, the matched resistive load of 48 Ω could deliver a high-voltage pulse with an amplitude of 100 kV. The full width at half maximum of the load pulse was 173 ns, and its rise time was less than 15 ns.

Development of bipolar pulse accelerator for intense pulsed ion beam acceleration

International Nuclear Information System (INIS)

Fujioka, Y.; Mitsui, C.; Kitamura, I.; Takahashi, T.; Masugata, K.; Tanoue, H.; Arai, K.

2003-01-01

To improve the purity of an intense pulsed ion beams a new type of pulsed ion beam accelerator named 'bipolar pulse accelerator (BPA)' was proposed. In the accelerator purity of the beam is expected. To confirm the principle of the accelerator experimental system was developed. The system utilizes B y type magnetically insulated acceleration gap and operated with single polar negative pulse. A coaxial gas puff plasma gun placed in the grounded anode was used as an ion source, and source plasma (nitrogen) of current density approx. = 25 A/cm 2 , duration approx. = 1.5 μs was injected into the acceleration gap. The ions are successfully accelerated from the grounded anode to the drift tube by applying negative pulse of voltage 180 kV, duration 60 ns to the drift tube. Pulsed ion beam of current density approx. = 40 A/cm 2 , duration approx. 60 ns was obtained at 42 mm downstream from the anode surface. (author)

Producing High Intense Attosecond Pulse Train by Interaction of Three-Color Pulse and Overdense Plasma

Science.gov (United States)

Salehi, M.; Mirzanejad, S.

2017-05-01

Amplifying the attosecond pulse by the chirp pulse amplification method is impossible. Furthermore, the intensity of attosecond pulse is low in the interaction of laser pulse and underdense plasma. This motivates us to propose using a multi-color pulse to produce the high intense attosecond pulse. In the present study, the relativistic interaction of a three-color linearly-polarized laser-pulse with highly overdense plasma is studied. We show that the combination of {{ω }}1, {{ω }}2 and {{ω }}3 frequencies decreases the instance full width at half maximum reflected attosecond pulse train from the overdense plasma surface. Moreover, we show that the three-color pulse increases the intensity of generated harmonics, which is explained by the relativistic oscillating mirror model. The obtained results demonstrate that if the three-color laser pulse interacts with overdense plasma, it will enhance two orders of magnitude of intensity of ultra short attosecond pulses in comparison with monochromatic pulse.

Migrações internas: evolução teórica e algumas evidências empíricas para o caso brasileiro

Directory of Open Access Journals (Sweden)

Márcia Regina Gabardo Câmara

1988-08-01

Full Text Available The aim of this article is to show new light concerning internal migration in Brazil. Consequently a review of the specialized literature was necessary and here in are presented some empirical evidences concerning its recent development. O objetivo do presente artigo é jogar novas luzes sobre a migração interna no Brasil. Conseqüentemente, foi necessário revisar a literatura especializada e apresentar algumas evidências empíricas sobre o seu desenvolvimento recente

Elementos teóricos para el análisis empírico de la demanda

Directory of Open Access Journals (Sweden)

Gustavo López,

2001-07-01

Full Text Available El presente artículo constituye una síntesis de la teoría de la demanda y su única pretensión es la de establecer el nexo –poco usual entre nosotros- entre esa teoría y sus aplicaciones, para lo cual es necesario destacar algunos aspectos particulares. Después de un breve repaso a los elementos teóricos básicos se detallan algunas características que debe cumplir una función de demanda para que resulte adecuada a los requerimientos teóricos, así como algunas restricciones resultantes de la propia ecuación presupuestal y que impone límites a los valores de las elasticidades. Por último, se presentan algunos aspectos de la dualidad en la teoría de la demanda que son especialmente útiles en el manejo empírico.

Concave pulse shaping of a circularly polarized laser pulse from non-uniform overdense plasmas

Energy Technology Data Exchange (ETDEWEB)

Hur, Min Sup [School of Natural Science, UNIST, BanYeon-Ri 100, Ulju-gun, Ulsan, 689-798 (Korea, Republic of); Kulagin, Victor V. [Sternberg Astronomical Institute, Moscow State University, Universitetsky prosp. 13, Moscow, 119992 (Russian Federation); Suk, Hyyong, E-mail: hysuk@gist.ac.kr [Department of Physics and Photon Science, GIST, 123 Cheomdan-gwangiro, Buk-gu, Gwangju, 500-712 (Korea, Republic of)

2015-03-20

Pulse shaping of circularly polarized laser pulses in nonuniform overdense plasmas are investigated numerically. Specifically we show by two-dimensional particle-in-cell simulations the generation of a concave pulse front of a circularly polarized, a few tens of petawatt laser pulse from a density-tapered, overdense plasma slab. The concept used for the transverse-directional shaping is the differential transmittance depending on the plasma density, and the laser intensity. For suitable selection of the slab parameters for the concave pulse shaping, we studied numerically the pulse transmittance, which can be used for further parameter design of the pulse shaping. The concavely shaped circularly polarized pulse is expected to add more freedom in controlling the ion-beam characteristics in the RPDA regime. - Highlights: • Laser pulse shaping for a concave front by non-uniform overdense plasma was studied. • Particle-in-cell (PIC) simulations were used for the investigation. • A laser pulse can be shaped by a density-tapered overdense plasma. • The concave and sharp pulse front are useful in many laser–plasma applications. • They are important for ion acceleration, especially in the radiation pressure dominant regime.

High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

National Research Council Canada - National Science Library

Wilson, Clay

2005-01-01

.... This method is called High Power Microwave (HPM). Several nations, including reported sponsors of terrorism, may currently have a capability to use EMP as a weapon to disrupt communications and other parts of the U.S...

Evolución y determinantes de las exportaciones industriales regionales: evidencia empírica para Colombia (1977-2002

Directory of Open Access Journals (Sweden)

Lotero Contreras Jorge

2011-09-01

Full Text Available
Este artículo examina el impacto de las variables macroeconómicas, de la productividad y de la
geografía sobre las exportaciones industriales colombianas entre 1977 y 2002, usando datos de la
Encuesta Nacional Manufacturera y de Comercio Exterior del DANE. El estudio se centra en las
exportaciones al mundo, a Estados Unidos y a la Comunidad Andina de Naciones-CAN. La
estrategia empírica incluye análisis de datos de panel cuyos resultados sugieren que para los
mercados considerados, la distancia, la productividad y la protección efectiva tienen un efecto
apreciable –aunque diferenciado–, sobre el comportamiento de las exportaciones industriales

Long-pulse applications of pulse-forming lines for high-power linac application

International Nuclear Information System (INIS)

Hoeberling, R.F.; Tallerico, P.J.

1981-01-01

The ever present demands for high efficiency in the RF power stations for particle accelerators have caused increased interest in longer RF pulses (ten's of microseconds) for linacs such as the Pion Generator for Medical Irradiation (PIGMI) and Free Electron Laser (FEL). For either RF power station, a fundamental decision is whether to use a modulating anode/hard-tube driver or pulsed cathode/line-type pulser configuration. The choices in the extremes of low power for very long pulses or for very-high-power, short pulses are, respectively, a modulated anode/hard tube modulator and pulsed cathode/pulse forming line. However, the demarcation between these two extremes is not clearcut. The criteria (cost, flexibility performance, reliability, efficiency) that resulted in the RF station definition of these two specific systems will be described

Arduino based radiation survey meter

Energy Technology Data Exchange (ETDEWEB)

Rahman, Nur Aira Abd, E-mail: nur-aira@nm.gov.my; Lombigit, Lojius; Abdullah, Nor Arymaswati; Azman, Azraf; Dolah, Taufik; Jaafar, Zainudin; Mohamad, Glam Hadzir Patai; Ramli, Abd Aziz Mhd; Zain, Rasif Mohd; Said, Fazila; Khalid, Mohd Ashhar; Taat, Muhamad Zahidee [Malaysian Nuclear Agency, 43000, Bangi, Selangor (Malaysia); Muzakkir, Amir [Sinaran Utama Teknologi Sdn Bhd, 43650, Bandar Baru Bangi, Selangor (Malaysia)

2016-01-22

This paper presents the design of new digital radiation survey meter with LND7121 Geiger Muller tube detector and Atmega328P microcontroller. Development of the survey meter prototype is carried out on Arduino Uno platform. 16-bit Timer1 on the microcontroller is utilized as external pulse counter to produce count per second or CPS measurement. Conversion from CPS to dose rate technique is also performed by Arduino to display results in micro Sievert per hour (μSvhr{sup −1}). Conversion factor (CF) value for conversion of CPM to μSvhr{sup −1} determined from manufacturer data sheet is compared with CF obtained from calibration procedure. The survey meter measurement results are found to be linear for dose rates below 3500 µSv/hr.

Development of bipolar-pulse accelerator for intense pulsed ion beam acceleration

Energy Technology Data Exchange (ETDEWEB)

Masugata, Katsumi [Department of Electrical and Electronic System Engineering, Toyama University, 3190 Gofuku, Toyama 930-8555 (Japan)]. E-mail: masugata@eng.toyama-u.ac.jp; Shimizu, Yuichro [Department of Electrical and Electronic System Engineering, Toyama University, 3190 Gofuku, Toyama 930-8555 (Japan); Fujioka, Yuhki [Department of Electrical and Electronic System Engineering, Toyama University, 3190 Gofuku, Toyama 930-8555 (Japan); Kitamura, Iwao [Department of Electrical and Electronic System Engineering, Toyama University, 3190 Gofuku, Toyama 930-8555 (Japan); Tanoue, Hisao [National Institute of Advanced Industry Science and Technology, 1-1-1, Umezono, Tsukuba-shi, Ibaraki 305-8568 (Japan); Arai, Kazuo [National Institute of Advanced Industry Science and Technology, 1-1-1, Umezono, Tsukuba-shi, Ibaraki 305-8568 (Japan)

2004-12-21

To improve the purity of intense pulsed ion beams, a new type of pulsed ion beam accelerator named 'bipolar pulse accelerator' was proposed. To confirm the principle of the accelerator a prototype of the experimental system was developed. The system utilizes By type magnetically insulated acceleration gap and operated with single polar negative pulse. A coaxial gas puff plasma gun was used as an ion source, which was placed inside the grounded anode. Source plasma (nitrogen) of current density {approx}25A/cm2, duration {approx}1.5{mu}s was injected into the acceleration gap by the plasma gun. The ions were successfully accelerated from the grounded anode to the drift tube by applying negative pulse of voltage 240kV, duration 100ns to the drift tube. Pulsed ion beam of current density {approx}40A/cm2, duration {approx}50ns was obtained at 41mm downstream from the anode surface. To evaluate the irradiation effect of the ion beam to solid material, an amorphous silicon thin film of thickness {approx}500nm was used as the target, which was deposited on the glass substrate. The film was found to be poly-crystallized after 4-shots of the pulsed nitrogen ion beam irradiation.

High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

National Research Council Canada - National Science Library

Wilson, Clay

2006-01-01

.... This method is called High Power Microwave (HPM). Several nations, including sponsors of terrorism, may currently have a capability to use EMP as a weapon for cyberterrorism to disrupt communications and other parts of the U.S...

High Altitude Electromagnetic Pulse (HEMP) and High Power Microwave (HPM) Devices: Threat Assessments

National Research Council Canada - National Science Library

Wilson, Clay

2008-01-01

... for cyber warfare or cyber terrorism to disrupt communications and other parts of the U.S. critical infrastructure. Also, some equipment and weapons used by the U.S. military may be vulnerable to the effects of EMP.

Erbium:ytterbium fiber-laser system delivering watt-level femtosecond pulses using divided pulse amplification

Science.gov (United States)

Herda, Robert; Zach, Armin

2015-03-01

We present an Erbium:Ytterbium codoped fiber-amplifer system based on Divided-Pulses-Amplification (DPA) for ultrashort pulses. The output from a saturable-absorber mode-locked polarization-maintaining (PM) fiber oscillator is amplified in a PM normal-dispersion Erbium-doped fiber. After this stage the pulses are positively chirped and have a duration of 2.0 ps at an average power of 93 mW. A stack of 5 birefringent Yttrium-Vanadate crystals divides these pulses 32 times. We amplify these pulses using a double-clad Erbium:Ytterbium codoped fiber pumped through a multimode fiber combiner. The pulses double pass the amplifier and recombine in the crystals using non-reciprocal polarization 90° rotation by a Faraday rotating mirror. Pulses with a duration of 144 fs are obtained after separation from the input beam using a polarizing beam splitter cube. These pulses have an average power of 1.85 W at a repetition rate of 80 MHz. The generation of femtosecond pulses directly from the amplifier was enabled by a positively chirped seed pulse, normally dispersive Yttrium-Vanadate crystals, and anomalously dispersive amplifier fibers. Efficient frequency doubling to 780 nm with an average power of 725 mW and a pulse duration of 156 fs is demonstrated. In summary we show a DPA setup that enables the generation of femtosecond pulses at watt-level at 1560 nm without the need for further external dechirping and demonstrate a good pulse quality by efficient frequency doubling. Due to the use of PM fiber components and a Faraday rotator the setup is environmentally stable.

DogPulse

DEFF Research Database (Denmark)

Skovgaard, Christoffer; Thomsen, Josephine Raun; Verdezoto, Nervo

2015-01-01

This paper presents DogPulse, an ambient awareness system to support the coordination of dog walking among family members at home. DogPulse augments a dog collar and leash set to activate an ambient shape-changing lamp and visualize the last time the dog was taken for a walk. The lamp gradually...... changes its form and pulsates its lights in order to keep the family members aware of the dog walking activity. We report the iterative prototyping of DogPulse, its implementation and its preliminary evaluation. Based on our initial findings, we present the limitations and lessons learned as well...

Managing talent flow : 2006 energy and resources talent pulse survey report

International Nuclear Information System (INIS)

2006-08-01

The Canadian energy sector is experiencing a labour shortage. It is expected that by 2025, the province of Alberta could face a shortfall of 332,000 workers. The impending shortage has already caused concern among energy sector organizations. This survey was conducted among 55 Canadian oil and gas, utilities, and mining organizations to better understand the extent of the talent crisis. The survey examined specific resources shortages, talent issues and their impacts on performance. Efforts on behalf of organizations to address the labour shortage were also reviewed. Respondents to the survey identified a clear link between talent management and organizational performance. Nearly 80 per cent of the respondents indicated that the talent shortage has limited productivity and efficiency in their organization. Fifty-five per cent indicated that the talent shortage will limit the ability to meet production requirements and customer demand, while 47 per cent said that the lack of skilled workers will affect their organization's ability to innovate. Attracting specific types of labour was seen as one of the top 3 issues facing organizations. The survey indicated that some organizations have increased their investment in recruiting experienced staff, but are relying on old recruiting tactics to meet changing needs. It was also noted that employees are now placing greater importance on opportunities for growth, development and communication, rather than on pay alone. It was stated that Deloitte's model for talent management was designed to optimize the employee experience in an environment where employees expect opportunities for personal growth. It was concluded that the future success of Canada's energy and resources sector will rely on how well organizations address the talent shortage. 8 figs

The SUrvey for Pulsars and Extragalactic Radio Bursts - I. Survey description and overview

Science.gov (United States)

Keane, E. F.; Barr, E. D.; Jameson, A.; Morello, V.; Caleb, M.; Bhandari, S.; Petroff, E.; Possenti, A.; Burgay, M.; Tiburzi, C.; Bailes, M.; Bhat, N. D. R.; Burke-Spolaor, S.; Eatough, R. P.; Flynn, C.; Jankowski, F.; Johnston, S.; Kramer, M.; Levin, L.; Ng, C.; van Straten, W.; Krishnan, V. Venkatraman

2018-01-01

We describe the Survey for Pulsars and Extragalactic Radio Bursts (SUPERB), an ongoing pulsar and fast transient survey using the Parkes radio telescope. SUPERB involves real-time acceleration searches for pulsars and single-pulse searches for pulsars and fast radio bursts. We report on the observational set-up, data analysis, multiwavelength/messenger connections, survey sensitivities to pulsars and fast radio bursts and the impact of radio frequency interference. We further report on the first 10 pulsars discovered in the project. Among these is PSR J1306-40, a millisecond pulsar in a binary system where it appears to be eclipsed for a large fraction of the orbit. PSR J1421-4407 is another binary millisecond pulsar; its orbital period is 30.7 d. This orbital period is in a range where only highly eccentric binaries are known, and expected by theory; despite this its orbit has an eccentricity of 10-5.

Development of PIC-based digital survey meter

International Nuclear Information System (INIS)

Nor Arymaswati Abdullah; Nur Aira Abdul Rahman; Mohd Ashhar Khalid; Taiman Kadni; Glam Hadzir Patai Mohamad; Abd Aziz Mhd Ramli; Chong Foh Yong

2006-01-01

The need of radiation monitoring and monitoring of radioactive contamination in the workplace is very important especially when x-ray machines, linear accelerators, electron beam machines and radioactive sources are present. The appropriate use of radiation detector is significant in order to maintain a radiation and contamination free workplace. This paper reports on the development of a prototype of PIC-based digital survey meter. This prototype of digital survey meter is a hand held instrument for general-purpose radiation monitoring and surface contamination meter. Generally, the device is able to detect some or all of the three major types of ionizing radiation, namely alpha, beta and gamma. It uses a Geiger-Muller tube as a radiation detector, which converts gamma radiation quanta to electric pulses and further processed by the electronic devices. The development involved the design of the controller, counter and high voltage circuit. All these circuit are assembled and enclosed in a plastic casing together with a GM detector and LCD display to form a prototype survey meter. The number of counts of the pulses detected by the survey meter varies due to the random nature of radioactivity. By averaging the reading over a time-period, more accurate and stable reading is achieved. To test the accuracy and the linearity of the design, the prototype was calibrated using standard procedure at the Secondary Standard Dosimetry Laboratory (SSDL) in MINT. (Author)

A Scintillometer Assembly for Geological Survey

Energy Technology Data Exchange (ETDEWEB)

Dissing, E; Landstroem, O

1965-12-15

An instrument for gamma radiation measurements in connection with geological survey is described. It consists of a scintillation detector with a 5x6 inch sodium iodide crystal and a pulse height analyzer with four independent channels. In field survey work these channels are usually set in fixed positions to record different components of the gamma radiation simultaneously in order to facilitate an identification of the radioactive mineral from which the radiation originates. However, the instrument can also be used for more detailed study of gamma spectra either in the field or in the laboratory. The methods for interpretation of gamma spectra from radioactive ores are briefly reviewed, and a few typical results are given from car-borne and air-borne surveys.

A Scintillometer Assembly for Geological Survey

International Nuclear Information System (INIS)

Dissing, E.; Landstroem, O.

1965-12-01

An instrument for gamma radiation measurements in connection with geological survey is described. It consists of a scintillation detector with a 5x6 inch sodium iodide crystal and a pulse height analyzer with four independent channels. In field survey work these channels are usually set in fixed positions to record different components of the gamma radiation simultaneously in order to facilitate an identification of the radioactive mineral from which the radiation originates. However, the instrument can also be used for more detailed study of gamma spectra either in the field or in the laboratory. The methods for interpretation of gamma spectra from radioactive ores are briefly reviewed, and a few typical results are given from car-borne and air-borne surveys

Optimization methods of pulse-to-pulse alignment using femtosecond pulse laser based on temporal coherence function for practical distance measurement

Science.gov (United States)

Liu, Yang; Yang, Linghui; Guo, Yin; Lin, Jiarui; Cui, Pengfei; Zhu, Jigui

2018-02-01

An interferometer technique based on temporal coherence function of femtosecond pulses is demonstrated for practical distance measurement. Here, the pulse-to-pulse alignment is analyzed for large delay distance measurement. Firstly, a temporal coherence function model between two femtosecond pulses is developed in the time domain for the dispersive unbalanced Michelson interferometer. Then, according to this model, the fringes analysis and the envelope extraction process are discussed. Meanwhile, optimization methods of pulse-to-pulse alignment for practical long distance measurement are presented. The order of the curve fitting and the selection of points for envelope extraction are analyzed. Furthermore, an averaging method based on the symmetry of the coherence function is demonstrated. Finally, the performance of the proposed methods is evaluated in the absolute distance measurement of 20 μ m with path length difference of 9 m. The improvement of standard deviation in experimental results shows that these approaches have the potential for practical distance measurement.

Pulse frequency in pulsed brachytherapy based on tissue repair kinetics

International Nuclear Information System (INIS)

Sminia, Peter; Schneider, Christoph J.; Koedooder, Kees; Tienhoven, Geertjan van; Blank, Leo E.C.M.; Gonzalez Gonzalez, Dionisio

1998-01-01

Purpose: Investigation of normal tissue sparing in pulsed brachytherapy (PB) relative to continuous low-dose rate irradiation (CLDR) by adjusting pulse frequency based on tissue repair characteristics. Method: Using the linear quadratic model, the relative effectiveness (RE) of a 20 Gy boost was calculated for tissue with an α/β ratio ranging from 2 to 10 Gy and a half-time of sublethal damage repair between 0.1 and 3 h. The boost dose was considered to be delivered either in a number of pulses varying from 2 to 25, or continuously at a dose rate of 0.50, 0.80, or 1.20 Gy/h. Results: The RE of 20 Gy was found to be identical for PB in 25 pulses of 0.80 Gy each h and CLDR delivered at 0.80 Gy/h for any α/β value and for a repair half-time > 0.75 h. When normal tissue repair half-times are assumed to be longer than tumor repair half-times, normal tissue sparing can be obtained, within the restriction of a fixed overall treatment time, with higher dose per pulse and longer period time (time elapsed between start of pulse n and start of pulse n + 1). An optimum relative normal tissue sparing larger than 10% was found with 4 pulses of 5 Gy every 8 h. Hence, a therapeutic gain might be obtained when changing from CLDR to PB by adjusting the physical dose in such a way that the biological dose on the tumor is maintained. The normal tissue-sparing phenomenon can be explained by an increase in RE with longer period time for tissue with high α/β ratio and fast or intermediate repair half-time, and the RE for tissue with low α/β ratio and long repair half-time remains almost constant. Conclusion: Within the benchmark of the LQ model, advantage in normal tissue-sparing is expected when matching the pulse frequency to the repair kinetics of the normal tissue exposed. A period time longer than 1 h may lead to a reduction of late normal tissue complications. This theoretical advantage emphasizes the need for better knowledge of human tissue-repair kinetics

Controlling output pulse and prepulse in a resonant microwave pulse compressor

International Nuclear Information System (INIS)

Shlapakovski, A.; Artemenko, S.; Chumerin, P.; Yushkov, Yu.

2013-01-01

A resonant microwave pulse compressor with a waveguide H-plane-tee-based energy extraction unit was studied in terms of its capability to produce output pulses that comprise a low-power long-duration (prepulse) and a high-power short-duration part. The application of such combined pulses with widely variable prepulse and high-power pulse power and energy ratios is of interest in the research area of electronic hardware vulnerability. The characteristics of output radiation pulses are controlled by the variation of the H-plane tee transition attenuation at the stage of microwave energy storage in the compressor cavity. Results of theoretical estimations of the parameters tuning range and experimental investigations of the prototype S-band compressor (1.5 MW, 12 ns output pulse; ∼13.2 dB gain) are presented. The achievable maximum in the prepulse power is found to be about half the power of the primary microwave source. It has been shown that the energy of the prepulse becomes comparable with that of the short-duration (nanosecond) pulse, while the power of the latter decreases insignificantly. The possible range of variation of the prepulse power and energy can be as wide as 40 dB. In the experiments, the prepulse level control within the range of ∼10 dB was demonstrated.

Dynamics of traveling reaction pulses

International Nuclear Information System (INIS)

Dovzhenko, A. Yu.; Rumanov, E. N.

2007-01-01

The growth of activator losses is accompanied by the decay of a traveling reaction pulse. In a ring reactor, this propagation threshold is present simultaneously with a threshold related to the ring diameter. The results of numerical experiments with pulses of an exothermal reaction reveal the transition from pulse propagation to a homogeneous hot regime, established regimes with periodic variations of the pulse velocity, and oscillatory decay of the pulse. When the medium becomes 'bistable' as a result of the variation in parameters, this factor does not prevent the propagation of pulses, but leads to changes in the pulse structure

River water remediation using pulsed corona, pulsed spark or ozonation

Energy Technology Data Exchange (ETDEWEB)

Izdebski, T.; Dors, M. [Polish Academy of Sciences, Szewalski Inst. of Fluid Flow Machiney, Fiszera (Poland). Centre for Plasma and Laser Engineering; Mizeraczyk, J. [Polish Academy of Sciences, Szewalski Inst. of Fluid Flow Machiney, Fiszera (Poland). Centre for Plasma and Laser Engineering; Gdynia Maritime Univ., Morska (Poland). Dept. of Marine Electronics

2010-07-01

The most common reason for epidemic formation is the pollution of surface and drinking water by wastewater bacteria. Pathogenic microorganisms that form the largest part of this are fecal bacteria, such as escherichia coli (E. coli). Wastewater treatment plants reduce the amount of the fecal bacteria by 1-3 orders of magnitude, depending on the initial number of bacteria. There is a lack of data on waste and drinking water purification by the electrohydraulic discharges method, which causes the destruction and inactivation of viruses, yeast, and bacteria. This paper investigated river water cleaning from microorganisms using pulsed corona, spark discharge and ozonization. The paper discussed the experimental setup and results. It was concluded that ozonization is the most efficient method of water disinfection as compared with pulsed spark and pulsed corona discharges. The pulsed spark discharge in water was capable of killing all microorganism similarly to ozonization, but with much lower energy efficiency. The pulsed corona discharge was found to be the less effective method of water disinfection. 21 refs., 4 figs.

Physical model of reactor pulse

International Nuclear Information System (INIS)

Petrovic, A.; Ravnik, M.

2004-01-01

Pulse experiments have been performed at J. Stefan Institute TRIGA reactor since 1991. In total, more than 130 pulses have been performed. Extensive experimental information on the pulse physical characteristics has been accumulated. Fuchs-Hansen adiabatic model has been used for predicting and analysing the pulse parameters. The model is based on point kinetics equation, neglecting the delayed neutrons and assuming constant inserted reactivity in form of step function. Deficiencies of the Fuchs-Hansen model and systematic experimental errors have been observed and analysed. Recently, the pulse model was improved by including the delayed neutrons and time dependence of inserted reactivity. The results explain the observed non-linearity of the pulse energy for high pulses due to finite time of pulse rod withdrawal and the contribution of the delayed neutrons after the prompt part of the pulse. The results of the improved model are in good agreement with experimental results. (author)

Aprendizaje Cooperativo: Bases teóricas y hallazgos empíricos que explican su eficacia

Directory of Open Access Journals (Sweden)

Edurne Goikoetxea

2002-01-01

Full Text Available El aprendizaje cooperativo (AC es una de las formas de organizar la enseñanza con mayor respaldo teórico y empírico, y cada vez más empleada. Este trabajo revisa la teoría del contacto de Allport (1954/1962 para explicar por qué los métodos de AC tienen efectos positivos en las relaciones intergrupales e interétnicas. El modelo de Slavin (1984 se revisa para juzgar los elementos de una instrucción eficaz que logran ser satisfechos por el AC, dando lugar a efectos positivos en el rendimiento académico. Se describen, además, los nueve métodos de AC más investigados y se resumen los principales hallazgos sobre sus efectos, así como los mecanismos que explican dichos efectos, según los estudios de revisión y de meta-análisis

Um estudo empírico de um sistema de reconhecimento facial utilizando o classificador KNN

Directory of Open Access Journals (Sweden)

Fabio Abrantes Diniz

2016-06-01

Full Text Available Neste artigo, apresenta-se um estudo empírico de otimização das taxas de acurácias resultantes de um sistema de reconhecimento facial baseado nas técnicas Eigenfaces e K-Nearest Neighbors. Foram investigadas as seguintes variáveis: imagens com três dimensões distintas, número de características (Eigenfaces, valores de k da técnica K-Nearest Neighbors e três medidas de distância (euclidiana, Manhattan e euclidiana normalizada. Os estudos foram importantes para entender empiricamente quais parâmetros são os mais relevantes para as técnicas analisadas e que resultam em melhores taxas de acurácias de reconhecimento facial. Os resultados dos experimentos comprovaram que as imagens com dimensões 12x9 pixels produzem as melhores taxas de acurácias de reconhecimento facial, combinando com a medida de distância euclidiana normalizada e um número de Eigenfaces igual a vinte.

Dual-Pulse Pulse Position Modulation (DPPM) for Deep-Space Optical Communications: Performance and Practicality Analysis

Science.gov (United States)

Li, Jing; Hylton, Alan; Budinger, James; Nappier, Jennifer; Downey, Joseph; Raible, Daniel

2012-01-01

Due to its simplicity and robustness against wavefront distortion, pulse position modulation (PPM) with photon counting detector has been seriously considered for long-haul optical wireless systems. This paper evaluates the dual-pulse case and compares it with the conventional single-pulse case. Analytical expressions for symbol error rate and bit error rate are first derived and numerically evaluated, for the strong, negative-exponential turbulent atmosphere; and bandwidth efficiency and throughput are subsequently assessed. It is shown that, under a set of practical constraints including pulse width and pulse repetition frequency (PRF), dual-pulse PPM enables a better channel utilization and hence a higher throughput than it single-pulse counterpart. This result is new and different from the previous idealistic studies that showed multi-pulse PPM provided no essential information-theoretic gains than single-pulse PPM.

LUPIN, a new instrument for pulsed neutron fields

Energy Technology Data Exchange (ETDEWEB)

Caresana, M. [Politecnico di Milano, Department of Energy, Via Ponzio 34/3, 20133 Milan (Italy); Ferrarini, M. [Politecnico di Milano, Department of Energy, Via Ponzio 34/3, 20133 Milan (Italy); CNAO, Via Privata Campeggi, 27100 Pavia (Italy); Manessi, G.P., E-mail: giacomo.paolo.manessi@cern.ch [CERN, 1211 Geneva 23 (Switzerland); University of Liverpool, Department of Physics, L69 7ZE Liverpool (United Kingdom); Silari, M. [CERN, 1211 Geneva 23 (Switzerland); Varoli, V. [Politecnico di Milano, Department of Energy, Via Ponzio 34/3, 20133 Milan (Italy)

2013-06-01

A number of studies focused in the last decades on the development of survey meters to be used in pulsed radiation fields. This is a topic attracting widespread interest for applications such as radiation protection and beam diagnostics in accelerators. This paper describes a new instrument specifically conceived for applications in pulsed neutron fields (PNF). The detector, called LUPIN, is a rem counter type instrument consisting of a {sup 3}He proportional counter placed inside a spherical moderator. It works in current mode with a front-end electronics consisting of a current–voltage logarithmic amplifier, whose output signal is acquired with an ADC and processed on a PC. This alternative signal processing allows the instrument to be used in PNF without being affected by saturation effects. Moreover, it has a measurement capability ranging over many orders of burst intensity. Despite the fact that it works in current mode, it can measure a single neutron interaction. The LUPIN was first calibrated in CERN's calibration laboratory with a PuBe source. Measurements were carried out under various experimental conditions at the Helmholtz-Zentrum in Berlin, in the stray field at various locations of the CERN Proton Synchrotron complex and around a radiotherapy linear accelerator at the S. Raffaele hospital in Milan. The detector can withstand single bursts with values of H⁎(10) up to 16 nSv/burst without showing any saturation effect. It efficiently works in pulsed stray fields, where a conventional rem-counter underestimates by a factor of 2. It is also able to reject the very intense and pulsed photon contribution that often accompanies the neutron field with good reliability. -- Highlights: ► LUPIN is a new detector specifically conceived to work in neutron pulsed fields. ► The detector is a rem counter type instrument working in current mode. ► The performances of the detectors were studied under various experimental conditions. ► The detector

Controlled generation of a single Trichel pulse and a series of single Trichel pulses in air

Science.gov (United States)

Mizeraczyk, Jerzy; Berendt, Artur; Akishev, Yuri

2018-04-01

In this paper, a simple method for the controlled generation of a single Trichel pulse or a series of single Trichel pulses of a regulated repetition frequency in air is proposed. The concept of triggering a single Trichel pulse or a series of such pulses is based on the precise controlling the voltage inception of the negative corona, which can be accomplished through the use of a ramp voltage pulse or a series of such pulses with properly chosen ramp voltage pulse parameters (rise and fall times, and ramp voltage pulse repetition frequency). The proposal has been tested in experiments using a needle-to-plate electrode arrangement in air, and reproducible Trichel pulses (single or in a series) were obtained by triggering them with an appropriately designed voltage waveform. The proposed method and results obtained have been qualitatively analysed. The analysis provides guidance for designing the voltage ramp pulse in respect of the generation of a single Trichel pulse or a series of single Trichel pulses. The controlled generation of a single Trichel pulse or a series of such pulses would be a helpful research tool for the refined studies of the fundamental processes in a negative corona discharge in a single- (air is an example) and multi-phase gaseous fluids. The controlled generation of a single Trichel pulse or a series of Trichel pulses can also be attractive for those corona treatments which need manipulation of the electric charge and heat portions delivered by the Trichel pulses to the object.

Recommended engineering practice to enhance the EMI/EMP immunity of electric power systems

Energy Technology Data Exchange (ETDEWEB)

Wagner, C.L.; Feero, W.E. (Electric Research and Management, Inc., State College, PA (United States))

1992-12-01

Many papers and reports have been written on studies conducted by the Oak Ridge National Laboratory and investigations by others on the effect of high-altitude electromagnetic pulses (HEMP) on electric power systems. More than 100 of the published unclassified documents were reviewed with the objectives of: 1. summarizing the mitigation methods suggested in the documents and providing a subjective evaluation of each 2. discussing various standards . that presently apply to the effects of HEMP on utility systems and suggesting additions or modifications or new standards where deficiencies appear to exist; and 3. recommending future studies or actions to improve the utility response to HEMP. While all three components of HEMP were mentioned, only the early-time short-duration E[sub 1] pulse and the late-time long-duration E[sub 3] pulse were considered in detail; the E[sub 2] intermediate component was not considered to affect the power system significantly.

Recommended engineering practice to enhance the EMI/EMP immunity of electric power systems

Energy Technology Data Exchange (ETDEWEB)

Wagner, C.L.; Feero, W.E. [Electric Research and Management, Inc., State College, PA (United States)

1992-12-01

Many papers and reports have been written on studies conducted by the Oak Ridge National Laboratory and investigations by others on the effect of high-altitude electromagnetic pulses (HEMP) on electric power systems. More than 100 of the published unclassified documents were reviewed with the objectives of: 1. summarizing the mitigation methods suggested in the documents and providing a subjective evaluation of each 2. discussing various standards . that presently apply to the effects of HEMP on utility systems and suggesting additions or modifications or new standards where deficiencies appear to exist; and 3. recommending future studies or actions to improve the utility response to HEMP. While all three components of HEMP were mentioned, only the early-time short-duration E{sub 1} pulse and the late-time long-duration E{sub 3} pulse were considered in detail; the E{sub 2} intermediate component was not considered to affect the power system significantly.

Insect cells are superior to Escherichia coli in producing malaria proteins inducing IgG targeting PfEMP1 on infected erythrocytes

DEFF Research Database (Denmark)

Victor, Michala E; Bengtsson, Anja; Andersen, Gorm

2010-01-01

-exposed epitopes are unknown. An insect cell and Escherichia coli based system was used to express single and double domains encoded by the pfd1235w var gene. The resulting recombinant proteins have been evaluated for yield and purity and their ability to induce rat antibodies, which react with the native PFD1235w...... PfEMP1 antigen expressed on 3D7PFD1235w-IE. Their recognition by human anti-malaria antibodies from previously infected Tanzanian donors was also analysed....

A high pulsed power supply system designed for pulsed high magnetic field

International Nuclear Information System (INIS)

Liu Kefu; Wang Shaorong; Zhong Heqing; Xu Yan; Pan Yuan

2008-01-01

This paper introduces the design of high pulsed power supply system for producing pulsed high magnetic field up to 70 T. This system consists of 58 sets of 55 μF of capacitor bank which provides 1.0 MJ energy storage. A set of vacuum closing switch is chosen as main switch for energy discharge into magnetic coil. A crowbar circuit with high power diodes in series with resistor is used to absorb the redundant energy and adjust pulse width. The resistance of magnetic coil changing with current is deduced by energy balance equations. A capacitor-charging power supply using a series-resonant, constant on-time variable frequency control, and zero-current switching charges the capacitor bank in one minute time with high efficiency. The pulsed power supply provides adjustable current and pulse width with 30 kA peak and 30 ms maximum. The primary experiments demonstrate the system reliability. This work provides an engineering guidance for future development of pulsed high magnetic field. (authors)

Managing talent flow : 2006 energy and resources talent pulse survey report

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-08-15

The Canadian energy sector is experiencing a labour shortage. It is expected that by 2025, the province of Alberta could face a shortfall of 332,000 workers. The impending shortage has already caused concern among energy sector organizations. This survey was conducted among 55 Canadian oil and gas, utilities, and mining organizations to better understand the extent of the talent crisis. The survey examined specific resources shortages, talent issues and their impacts on performance. Efforts on behalf of organizations to address the labour shortage were also reviewed. Respondents to the survey identified a clear link between talent management and organizational performance. Nearly 80 per cent of the respondents indicated that the talent shortage has limited productivity and efficiency in their organization. Fifty-five per cent indicated that the talent shortage will limit the ability to meet production requirements and customer demand, while 47 per cent said that the lack of skilled workers will affect their organization's ability to innovate. Attracting specific types of labour was seen as one of the top 3 issues facing organizations. The survey indicated that some organizations have increased their investment in recruiting experienced staff, but are relying on old recruiting tactics to meet changing needs. It was also noted that employees are now placing greater importance on opportunities for growth, development and communication, rather than on pay alone. It was stated that Deloitte's model for talent management was designed to optimize the employee experience in an environment where employees expect opportunities for personal growth. It was concluded that the future success of Canada's energy and resources sector will rely on how well organizations address the talent shortage. 8 figs.

CW seeded optical parametric amplifier providing wavelength and pulse duration tunable nearly transform limited pulses.

Science.gov (United States)

Hädrich, S; Gottschall, T; Rothhardt, J; Limpert, J; Tünnermann, A

2010-02-01

An optical parametric amplifier that delivers nearly transform limited pulses is presented. The center wavelength of these pulses can be tuned between 993 nm and 1070 nm and, at the same time, the pulse duration is varied between 206 fs and 650 fs. At the shortest pulse duration the pulse energy was increased up to 7.2 microJ at 50 kHz repetition rate. Variation of the wavelength is achieved by applying a tunable cw seed while the pulse duration can be varied via altering the pump pulse duration. This scheme offers superior flexibility and scaling possibilities.

Nonlinear Pulse Shaping in Fibres for Pulse Generation and Optical Processing

Directory of Open Access Journals (Sweden)

Sonia Boscolo

2012-01-01

Full Text Available The development of new all-optical technologies for data processing and signal manipulation is a field of growing importance with a strong potential for numerous applications in diverse areas of modern science. Nonlinear phenomena occurring in optical fibres have many attractive features and great, but not yet fully explored, potential in signal processing. Here, we review recent progress on the use of fibre nonlinearities for the generation and shaping of optical pulses and on the applications of advanced pulse shapes in all-optical signal processing. Amongst other topics, we will discuss ultrahigh repetition rate pulse sources, the generation of parabolic shaped pulses in active and passive fibres, the generation of pulses with triangular temporal profiles, and coherent supercontinuum sources. The signal processing applications will span optical regeneration, linear distortion compensation, optical decision at the receiver in optical communication systems, spectral and temporal signal doubling, and frequency conversion.

Fatores de impacto na Atitude e na Intenção de uso do M-learning: um teste empírico

Directory of Open Access Journals (Sweden)

Renata Kurtz

Full Text Available Este artigo apresenta os resultados de uma pesquisa empírica em que se propõe um modelo para avaliar a atitude e a intenção de uso do mobile-learning(m-learning por estudantes do ensino superior de um curso de administração baseado na teoria do flow, no Modelo de Aceitação de Tecnologia e na Teoria do Comportamento Planejado. A partir deste arcabouço teórico elaborou-se uma atividade prática envolvendo o uso de dispositivos com tecnologia móvel digital (celulares em que se buscou aplicar o m-learning para estimular os estudantes a unir a teoria à prática. Em seguida, foi feita uma survey respondida por 235 universitários, em que se buscou compreender os fatores que influenciam a atitude e a intenção de uso do m-learning para o processo de ensino-aprendizagem. Os dados coletados foram tratados por meio de equações estruturais e os resultados mostraram fortes efeitos positivos dos fatores utilidade, diversão e controle do comportamento percebidos pelos estudantes na atitude e na intenção de uso do m-learning. Por fim, verificou-se que a atividade de uso prático realizada com os alunos mostrou que o uso do celular em uma atividade acadêmica pôde proporcionar a construção e o entendimento deles das relações entre a teoria apresentada e a prática em um ambiente real.

Pulsed neutron generator for use with pulsed neutron activation techniques

International Nuclear Information System (INIS)

Rochau, G.E.

1980-01-01

A high-output, transportable, pulsed neutron generator has been developed by Sandia National Laboratories for use with Pulsed Neutron Activation (PNA) techniques. The PNA neutron generator generates > 10 10 14 MeV D-T neutrons in a 1.2 millisecond pulse. Each operation of the unit will produce a nominal total neutron output of 1.2 x 10 10 neutrons. The generator has been designed to be easily repaired and modified. The unit requires no additional equipment for operation or measurement of output

Matrimonios mixtos intraeuropeos: un modelo empírico (Intra-European intermarriage: an empirical model

Directory of Open Access Journals (Sweden)

Alaminos Chica, Antonio Francisco

2008-06-01

Full Text Available Resumen: La heterogeneidad con la que nos encontramos al estudiar las parejas interculturales o mixtas, va más allá de las diferencias de origen sociocultural; interviene factores tales como el rol que cada individuo adopta dentro de la pareja (por ejemplo, quién contribuye más económicamente, el status, el nivel educativo, etc.. En este artículo se propone un modelo empírico que muestra el efecto de un conjunto de variables, que expresan circunstancias sociales, sobre la decisión de formar un matrimonio interculturalmente mixto. También las consecuencias en la vida social del individuo.Abstract: The intercultural marriages or mixed marriages depend upon several factor. Not only the different cultural origin. Other determinants like the role of the partner (i.e. economic contribution, status, educational level, etc. or the type of the family (modern, traditional, etc. influence the outcomes. This paper contains a proposal of empirical model for study the intra-European mixed marriages.

Effect of laser pulse energies in laser induced breakdown spectroscopy in double-pulse configuration

International Nuclear Information System (INIS)

Benedetti, P.A.; Cristoforetti, G.; Legnaioli, S.; Palleschi, V.; Pardini, L.; Salvetti, A.; Tognoni, E.

2005-01-01

In this paper, the effect of laser pulse energy on double-pulse laser induced breakdown spectroscopy signal is studied. In particular, the energy of the first pulse has been changed, while the second pulse energy is held fixed. A systematic study of the laser induced breakdown spectroscopy signal dependence on the interpulse delay is performed, and the results are compared with the ones obtained with a single laser pulse of energy corresponding to the sum of the two pulses. At the same time, the crater formed at the target surface is studied by video-confocal microscopy, and the variation in crater dimensions is correlated to the enhancement of the laser induced breakdown spectroscopy signal. The results obtained are consistent with the interpretation of the double-pulse laser induced breakdown spectroscopy signal enhancement in terms of the changes in ambient gas pressure produced by the shock wave induced by the first laser pulse

Two-dimensional spatial survey of the plasma potential and electric field in a pulsed bipolar magnetron discharge

International Nuclear Information System (INIS)

Vetushka, A.; Karkari, S.K.; Bradley, J.W.

2004-01-01

Emissive and Langmuir probe techniques have been used to obtain two-dimensional (2D) spatial maps of the plasma potential V p , electric field E, and ion trajectories in a pulsed bipolar magnetron discharge. The magnetron was pulsed at a frequency of 100 kHz, with a 50% duty cycle and operated at an argon pressure of 0.74 Pa. The pulse wave form was characterized by three distinct phases: the 'overshoot', 'reverse', and 'on' phases. In the 'on' phase of the pulse, when the cathode voltage is driven to -670 V, the 2D spatial distribution of V p has a similar form to that in dc magnetron, with significant axial and radial electric fields in the bulk plasma, accelerating ions to the sheath edge above the cathode racetrack region. During the 'overshoot' phase (duration 200 ns), V p is raised to values greater than +330 V, more than 100 V above the cathode potential, with E pointing away from the target. In the 'reverse' phase V p has a value of +45 V at all measured positions, 2 V more positive than the target potential. In this phase there is no electric field present in the plasma. In the bulk of the plasma, the results from Langmuir probe and the emissive probe are in good agreement, however, in one particular region of the plasma outside the radius of the cathode, the emissive probe measurements are consistently more positive (up to 45 V in the 'on' time). This discrepancy is discussed in terms of the different frequency response of the probes and their perturbation of the plasma. A simple circuit model of the plasma-probe system has been proposed to explain our results. A brief discussion of the effect of the changing plasma potential distribution on the operation of the magnetron is given

Dose reduction in pulsed fluoroscopy by modifying the high-voltage pulse shape

International Nuclear Information System (INIS)

Sabau, M.N.; Phelps, G.

1988-01-01

This paper presents the dose reduction results in pulsed fluoroscopy by modifying the high-voltage pulse shape (HVPS). Since the HVPS in regular pulsed fluoroscopy has a long tail, the radiation pulse shape (RPS) is similar. Using specially designed circuitry in the high-voltage generator to produce a rectangular HVPS, and consequently a rectangular RPS, it was possible to obtain a reduction of up to 25% of patient exposure. This dose reduction obtained by cutting the long tail of RPS does not damage the image quality

Assessing the Threat from Electromagnetic Pulse (EMP). Volume 1: Executive Report

Science.gov (United States)

2017-07-31

Nuclear Security Administration, and the Counterproliferation and Chem/ Bio Defense Office of the Office of the Secretary of Defense. Previously, Dr... remediation , nuclear waste management and repository certification, and waste minimization; information technology programs in information surety

Protecting power equipment against magnetohydrodynamic effects (MHD of electromagnetic pulses (EMP

Directory of Open Access Journals (Sweden)

Gurevich Vladimir

2015-01-01

Full Text Available The article is devoted to the effects of geomagnetic-induced currents (GIC on electrical equipment of power systems and analyzes technical measures for protection against such effects. It is noted that the difference between highaltitude nuclear detonation and solar storm GICs forces applying different methods of electrical equipment protection. It also illustrates that enhancement of transformer immunity to GICs without saturation prevention is not an effective measure to protect the power system. The article offers a special relay designed for fast disconnection of the transformer under GICs.

Apparatus for generating nonlinear pulse patterns

Science.gov (United States)

Nakamura, N.M.I.

Apparatus for generating a plurality of nonlinear pulse patterns from a single linear pulse pattern. A first counter counts the pulses of the linear pulse pattern and a second counter counts the pulses of the nonlinear pulse pattern. A comparator compares the counts of both counters, and in response to an equal count, a gate is enabled to gate a pulse of the linear pattern as a pulse of the nonlinear pattern, the latter also resetting the first counter. Presettable dividers divide the pulses of each pattern before they are counted by the respective counters. Apparatus for generating a logarithmic pulse pattern from a linear pulse pattern to any log base is described. In one embodiment, a shift register is used in place of the second counter to be clocked by each pulse of the logarithmic pattern to generate the pattern. In another embodiment, a memory stores the logarithmic pattern and is addressed by the second counter which is clocked by the pulses of the logarithmic pulse pattern.

Pulsed neutron generator for mass flow measurement using the pulsed neutron activation technique

International Nuclear Information System (INIS)

Rochau, G.E.; Hornsby, D.R.; Mareda, J.F.; Riggan, W.C.

1980-01-01

A high-output, transportable neutron generator has been developed to measure mass flow velocities in reactor safety tests using the Pulsed Neutron Activation (PNA) Technique. The PNA generator produces >10 10 14 MeV D-T neutrons in a 1.2 millisecond pulse. The Millisecond Pulse (MSP) Neutron Tube, developed for this application, has an expected operational life of 1000 pulses, and it limits the generator pulse repetition rate to 12 pulses/minute. A semiconductor neutron detector is included in the generator package to monitor the neutron output. The control unit, which can be operated manually or remotely, also contains a digital display with a BCD output for the neutron monitor information. The digital logic of the unit controls the safety interlocks and rejects transient signals which could accidently fire the generator

Preconcepciones de ciencia y tecnología en los profesores de bachillerato: un estudio empírico en el estado de Guanajuato

OpenAIRE

Rebollo León, Jorge Luis

2008-01-01

En este artículo se presenta un estudio empírico con profesores que enseñan ciencias naturales a nivel Bachillerato. Actualmente muchos profesores mantienen una imagen deformada de lo que es la ciencia y la tecnología. Algunos la conciben como un conocimiento acabado e infalible, otros como una actividad a-histórica y a-problemática o bien hay quienes la conciben como un quehacer elitista y descontextualizado. El propósito de este estudio es conocer cuáles son las preconcepciones sobre la...

Encuadre normativo y empírico para un diagnóstico del trabajo infantil en México (Normative and empirical framework for a diagnose of child labour in Mexico

Directory of Open Access Journals (Sweden)

Mónica González Contró

2012-05-01

Full Text Available This paper seeks to diagnose the phenomenon of children and adolescent labour in Mexico from the legal and empirical perspective, while expecting to make visible underlying, persistent and oftenly hidden realities. With this framework, we present a general path concerning some legal instruments that allow us to define and categorize the studied phenomenon, and we carry out an empirical analysis from a series of indicators developed in the Module of child labour included in the National Survey of Occupation and Employment raised by National Institute of Statistics and Geography (Instituto Nacional de Estadística y Geografía, INEGI in 2009. Information and analyzed data allow us to conclude in a broad manner that the constitutional and legal prohibition to child labour has not fulfill its eradication, further more, not starting from the approach of rights has implied a position of more vulnerability to underage persons who work due to several circumstances, whether economical, social or cultural. En este trabajo se busca realizar una aproximación diagnóstica al fenómeno del trabajo infantil y adolescente en México con miras a visibilizar aspectos que han estado invisibilizados a lo largo del tiempo, desde la perspectiva legal y empírica. En este marco, se hace un recorrido general de algunos instrumentos legales que permiten definir y categorizar el fenómeno, y se realiza un análisis empírico a partir de una serie de indicadores surgidos del Módulo de Trabajo Infantil incluido en la Encuesta Nacional de Ocupación y Empleo levantada por el Instituto Nacional de Estadística y Geografía en el año 2009. La información manejada, así como los datos analizados permiten concluir de manera general que la prohibición constitucional y legal del trabajo infantil no ha conseguido su erradicación, y el no partir de un enfoque de derechos colocaría en una posición de mayor vulnerabilidad a las personas menores de edad que trabajan por

High current transistor pulse generator

International Nuclear Information System (INIS)

Nesterov, V.; Cassel, R.

1991-05-01

A solid state pulse generator capable of delivering high current trapezoidally shaped pulses into an inductive load has been developed at SLAC. Energy stored in the capacitor bank of the pulse generator is switched to the load through a pair of Darlington transistors. A combination of diodes and Darlington transistors is used to obtain trapezoidal or triangular shaped current pulses into an inductive load and to recover the remaining energy in the same capacitor bank without reversing capacitor voltage. The transistors work in the switch mode, and the power losses are low. The rack mounted pulse generators presently used at SLAC contain a 660 microfarad storage capacitor bank and can deliver 400 amps at 800 volts into inductive loads up to 3 mH. The pulse generators are used in several different power systems, including pulse to pulse bipolar power supplies and in application with current pulses distributed into different inductive loads. The current amplitude and discharge time are controlled by the central computer system through a specially developed multichannel controller. Several years of operation with the pulse generators have proven their consistent performance and reliability. 8 figs

Pulse power modulators - an overview

International Nuclear Information System (INIS)

Venkatramani, N.

2006-01-01

Pulse power modulators are electronic devices to provide, high voltage, high current, power bursts. Ideally, a modulator, with the means to shape and control the pulses, acts as a switch between a high voltage power supply and its load. This article gives an overview of the pulse power modulators: starting with the basics of pulse and modulation, it covers modulation topologies, different types of modulators, major subsystems and pulse measurement techniques. The various applications of pulse power modulators and the recent trends have been included at the end. (author)

Fatores de impacto na Atitude e na Intenção de uso do M-learning: um teste empírico

OpenAIRE

Kurtz, Renata; Macedo-Soares, T. Diana de; Ferreira, Jorge Brantes; Freitas, Angilberto Sabino de; Silva, Jorge Ferreira da

2015-01-01

Este artigo apresenta os resultados de uma pesquisa empírica em que se propõe um modelo para avaliar a atitude e a intenção de uso do mobile-learning(m-learning) por estudantes do ensino superior de um curso de administração baseado na teoria do flow, no Modelo de Aceitação de Tecnologia e na Teoria do Comportamento Planejado. A partir deste arcabouço teórico elaborou-se uma atividade prática envolvendo o uso de dispositivos com tecnologia móvel digital (celulares) em que se buscou aplicar o ...

Facilitadores institucionales y sociales para la gobernanza local de los riesgos medioambientales. Análisis empírico con municipios chilenos

Directory of Open Access Journals (Sweden)

Patricio Valdivieso

Full Text Available Resumen El contexto latinoamericano de exposición a riesgos medioambientales demanda un mayor entendimiento de los factores institucionales que tienen impacto en la gestión medioambiental local. Con el apoyo de métodos mixtos de investigación, este estudio examina hipótesis sobre relaciones entre factores políticos, institucionales, sociales y la gestión medioambiental municipal, en el contexto empírico de municipalidades chilenas. Los resultados sugieren que la combinación de factores políticos, arreglos y capacidades institucionales, y relaciones con la sociedad explican diferentes comportamientos municipales.

A method to reduce the suppression of relevant pulses in pulse weight discriminators

International Nuclear Information System (INIS)

Schwartz, P.

1975-01-01

The pulse height analyzer is used, for instance, with proportional counters. Pulses are broken down into amplitude ranges in accordance with their maximum amplitudes. In pulse height analyzers with real time analog-digital conversion only one deadtime is needed for the respective range selected. For this purpose, all discriminator thresholds of the amplitude stores connected parallel are actuated as an input pulse arrives. The leading edges of the discriminator signals set the amplitude range flip-flop. Only the flip-flop circuit of the maximum amplitude range reached remains set whilst all the others are erased. The trailing edge of the discriminator signals actuates the evaluation of the information stored by the flip-flop circuit selected. It triggers a pulse extender and resets the flip-flop selected. Therefore, only the amplitude range selected needs a deadtime. The pulse extender in addition reduces the processing time of the analyzer by the output pulse length. The characteristic used for the trailing edge is the backward count of the real time analog-digital converter. (DG/RF) [de

Wide Field Radio Transient Surveys

Science.gov (United States)

Bower, Geoffrey

2011-04-01

The time domain of the radio wavelength sky has been only sparsely explored. Nevertheless, serendipitous discovery and results from limited surveys indicate that there is much to be found on timescales from nanoseconds to years and at wavelengths from meters to millimeters. These observations have revealed unexpected phenomena such as rotating radio transients and coherent pulses from brown dwarfs. Additionally, archival studies have revealed an unknown class of radio transients without radio, optical, or high-energy hosts. The new generation of centimeter-wave radio telescopes such as the Allen Telescope Array (ATA) will exploit wide fields of view and flexible digital signal processing to systematically explore radio transient parameter space, as well as lay the scientific and technical foundation for the Square Kilometer Array. Known unknowns that will be the target of future transient surveys include orphan gamma-ray burst afterglows, radio supernovae, tidally-disrupted stars, flare stars, and magnetars. While probing the variable sky, these surveys will also provide unprecedented information on the static radio sky. I will present results from three large ATA surveys (the Fly's Eye survey, the ATA Twenty CM Survey (ATATS), and the Pi GHz Survey (PiGSS)) and several small ATA transient searches. Finally, I will discuss the landscape and opportunities for future instruments at centimeter wavelengths.

Pulsed corona generation using a diode-based pulsed power generator

Science.gov (United States)

Pemen, A. J. M.; Grekhov, I. V.; van Heesch, E. J. M.; Yan, K.; Nair, S. A.; Korotkov, S. V.

2003-10-01

Pulsed plasma techniques serve a wide range of unconventional processes, such as gas and water processing, hydrogen production, and nanotechnology. Extending research on promising applications, such as pulsed corona processing, depends to a great extent on the availability of reliable, efficient and repetitive high-voltage pulsed power technology. Heavy-duty opening switches are the most critical components in high-voltage pulsed power systems with inductive energy storage. At the Ioffe Institute, an unconventional switching mechanism has been found, based on the fast recovery process in a diode. This article discusses the application of such a "drift-step-recovery-diode" for pulsed corona plasma generation. The principle of the diode-based nanosecond high-voltage generator will be discussed. The generator will be coupled to a corona reactor via a transmission-line transformer. The advantages of this concept, such as easy voltage transformation, load matching, switch protection and easy coupling with a dc bias voltage, will be discussed. The developed circuit is tested at both a resistive load and various corona reactors. Methods to optimize the energy transfer to a corona reactor have been evaluated. The impedance matching between the pulse generator and corona reactor can be significantly improved by using a dc bias voltage. At good matching, the corona energy increases and less energy reflects back to the generator. Matching can also be slightly improved by increasing the temperature in the corona reactor. More effective is to reduce the reactor pressure.

Self-diffusion measurements in heterogeneous systems using NMR pulsed field gradient technique

International Nuclear Information System (INIS)

Heink, W.; Kaerger, J.; Walter, A.

1978-01-01

The experimental pecularities of the NMR pulsed field gradient technique are critical surveyed in its application to zeolite adsorbate adsorbent systems. After a presentation of the different transport parameters accessible by this technique, the consequences of the existence of inner field gradients being inherent to heterogeneous systems are analyzed. Experimental conditions and consequences of an application of pulsed field gradients of high intensity which are necessary for the measurement of small intracrystalline self-diffusion coefficients, are discussed. Gradient pulses of 0.15 Tcm -1 with pulse widths of 2 ms maximum and relative deviations of less than 0.01 per mille can be realized. Since for a number of adsorbate adsorbent systems a distinct dependence of the intracrystalline self-diffusion coeffcients on adsorbate concentration is observed, determination of zeolite pore fiiling factor is of considerable importance for the interpretation of the diffusivities obtained. It is demonstrated that also this information can be obtained by NMR technique in a straightforward way with a mean error of less than 5 to 10 %. Applying this new method and using an optimum experimental device as described, pore filling factor dependences of the self-diffusion coefficients of alkanes in NaX zeolites can be followed over more than two orders of magnitude. (author)

Comparison of AC electronic monitoring and field data for estimating tolerance to Empoasca kraemeri (Homoptera: Cicadellidae) in common bean genotypes.

Science.gov (United States)

Serrano, M S; Backus, E A; Cardona, C

2000-12-01

Two methods for estimating the tolerance of common bean genotypes to Empoasca kraemeri Ross & Moore were compared, using a yield trial carried out at Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia, versus stylet penetration tactics measured by AC electronic feeding monitors. A stylet penetration index was devised based on principal component scores of three penetration tactics identified (pulsing laceration, cell rupturing, and lancing sap ingestion), combined with knowledge of the hopperburn symptoms caused by each tactic. Tolerant genotypes, as classified by the CIAT yield index, showed significantly more unprotected yield and lower hopperburn scores than the susceptible control. They also induced performance of less pulsing laceration (the tactic considered most damaging to the plant), and more of the other two, mitigating tactics, especially cell rupturing. When index values were calculated for each genotype, stylet penetration index values matched those of the yield index for three out of five genotypes: two EMP-coded tolerant lines ('EMP 385' and 'EMP 392') and the susceptible control 'BAT 41'. Thus, for these three genotypes, all subsequent hoppereburn symptoms are predictable by the type of feeding behavior performed on them. 'Porrillo Sintético' and 'EMP 84', considered borderline genotypes by the yield index, were overestimated and underestimated respectively, by the stylet penetration index. We postulate that, for these two genotypes, plant physiological responses to feeding (either compensatory or heightened sensitivity, respectively) synergize with type of feeding performed to generate the overall hopperburn condition. This multivariate analysis of electronic monitoring data was successfully used to devise an index of resistance. The implications of using the stylet penetration index and the advantages of using electronic monitoring in a bean-breeding program are discussed.

Laser ablation comparison by picosecond pulses train and nanosecond pulse

Science.gov (United States)

Lednev, V. N.; Filippov, M. N.; Bunkin, A. F.; Pershin, S. M.

2015-12-01

A comparison of laser ablation by a train of picosecond pulses and nanosecond pulses revealed a difference in laser craters, ablation thresholds, plasma sizes and spectral line intensities. Laser ablation with a train of picosecond pulses resulted in improved crater quality while ablated mass decreased up to 30%. A reduction in laser plasma dimensions for picosecond train ablation was observed while the intensity of atomic/ionic lines in the plasma spectra was greater by a factor of 2-4 indicating an improved excitation and atomization in the plasma.

La restricción intertemporal del presupuesto. Una evaluación empírica para el Gobierno Nacional Central de Colombia, 1950-2010

Directory of Open Access Journals (Sweden)

Hernando Chaves Álvaro

2003-12-01

Full Text Available En este documento se analiza la sostenibilidad fiscal del Gobierno Nacional Central en Colombia utilizando el enfoque de la Restricción Intertemporal de Presupuesto. Los resultados empíricos revelan que la estrategia fiscal actual es sostenible. No obstante, se vislumbran problemas de insolvencia en el largo plazo, lo que implica generar un mayor superávit primario en comparación con el actualmente programado. Lo anterior, se sustenta en los valores estimados de los indicadores de sostenibilidad fiscal.

Particle acceleration by electromagnetic pulses

International Nuclear Information System (INIS)

Lai, H.M.

1982-01-01

Particle interaction with plane electromagnetic pulses is studied. It is shown that particle acceleration by a wavy pulse, depending on the shape of the pulse, may not be small. Further, a diffusive-type particle acceleration by multiple weak pulses is described and discussed. (author)

Perforate on CHO cell membranes induced by electromagnetic ...

African Journals Online (AJOL)

STORAGESEVER

2009-06-17

Jun 17, 2009 ... Key words: Electromagnetic pulse (EMP), atomic force microscope, CHO cell, cell membrane. INTRODUCTION .... of perforation ranges from 390 to 660 nm and the depth is. 392.95 nm. ... cell membrane perforations increased when both the field intensity and ..... Melatonin and a spin-trap compound block.

Hybrid Pulsed Nd:YAG Laser

Science.gov (United States)

Miller, Sawyer; Trujillo, Skyler; Fort Lewis College Laser Group Team

This work concerns the novel design of an inexpensive pulsed Nd:YAG laser, consisting of a hybrid Kerr Mode Lock (KLM) and Q-switch pulse. The two pulse generation systems work independently, non simultaneously of each other, thus generating the ability for the user to easily switch between ultra-short pulse widths or large energy density pulses. Traditionally, SF57 glass has been used as the Kerr medium. In this work, novel Kerr mode-locking mediums are being investigated including: tellurite compound glass (TeO2), carbon disulfide (CS2), and chalcogenide glass. These materials have a nonlinear index of refraction orders of magnitude,(n2), larger than SF57 glass. The Q-switched pulse will utilize a Pockels cell. As the two pulse generation systems cannot be operated simultaneously, the Pockels cell and Kerr medium are attached to kinematic mounts, allowing for quick interchange between systems. Pulse widths and repetition rates will vary between the two systems. A goal of 100 picosecond pulse widths are desired for the mode-locked system. A goal of 10 nanosecond pulse widths are desired for the Q-switch system, with a desired repetition rate of 50 Hz. As designed, the laser will be useful in imaging applications.

Modeling study on the effects of pulse rise rate in atmospheric pulsed discharges

Science.gov (United States)

Zhang, Yuan-Tao; Wang, Yan-Hui

2018-02-01

In this paper, we present a modeling study on the discharge characteristics driven by short pulsed voltages, focusing on the effects of pulse rise rate based on the fluid description of atmospheric plasmas. The numerical results show that the breakdown voltage of short pulsed discharge is almost linearly dependent on the pulse rise rate, which is also confirmed by the derived equations from the fluid model. In other words, if the pulse rise rate is fixed as a constant, the simulation results clearly suggest that the breakdown voltage is almost unchanged, although the amplitude of pulsed voltage increases significantly. The spatial distribution of the electric field and electron density are given to reveal the underpinning physics. Additionally, the computational data and the analytical expression also indicate that an increased repetition frequency can effectively decrease the breakdown voltage and current density, which is consistent with the experimental observation.

Intense isolated attosecond pulse generation from relativistic laser plasmas using few-cycle laser pulses

International Nuclear Information System (INIS)

Ma, Guangjin; Dallari, William; Borot, Antonin; Tsakiris, George D.; Veisz, Laszlo; Krausz, Ferenc; Yu, Wei

2015-01-01

We have performed a systematic study through particle-in-cell simulations to investigate the generation of attosecond pulse from relativistic laser plasmas when laser pulse duration approaches the few-cycle regime. A significant enhancement of attosecond pulse energy has been found to depend on laser pulse duration, carrier envelope phase, and plasma scale length. Based on the results obtained in this work, the potential of attaining isolated attosecond pulses with ∼100 μJ energy for photons >16 eV using state-of-the-art laser technology appears to be within reach

Electronic system for recording proportional counter rare pulses with the pulse shape analysis

International Nuclear Information System (INIS)

Barabanov, I.R.; Gavrin, V.N.; Zakharov, Yu.I.; Tikhonov, A.A.

1984-01-01

The anutomated system for recording proportional counter rare pulses is described. The proportional counters are aimed at identification of 37 Ar and H7 1 Gr decays in chemical radiation detectors of solar neutrino. Pulse shape recording by means of a storage oscilloscope and a TV display is performed in the system considered besides two-parametric selection of events (measurement of pulse amplitude in a slow channel and the amplitude of pulse differentiated with time constant of about 10 ns in a parallel fast channel). Pulse discrimination by a front rise rate provides background decrease in the 55 Fe range (5.9 keV) by 6 times; the visual analysis of pulse shapes recorded allows to decrease the background additionally by 25-30%. The background counting rate in the 55 Fe range being equal to 1 pulse per 1.5 days, is obtained when using the installation described above, as well as the passive Pb shield 5 cm thick, and the active shield based on the anticoincidence NaI(Tl) detector with the cathode 5.6 mm in-diameter made of Fe fabircated by zone melting. The installation described allows to reach the background level of 0.6 pulse/day (the total coefficient of background attenuation is 400). Further background decrease is supposed to be provided by installation allocation in the low-noise underground laboratory of the Baksan Neutrino Observatory

Pulsed corona generation using a diode-based pulsed power generator

NARCIS (Netherlands)

Pemen, A.J.M.; Grekhov, I.V.; Heesch, van E.J.M.; Yan, K.; Nair, S.A.; Korotkov, S.V.

2003-01-01

Pulsed plasma techniques serve a wide range of unconventional processes, such as gas and water processing, hydrogen production, and nanotechnology. Extending research on promising applications, such as pulsed corona processing, depends to a great extent on the availability of reliable, efficient and

Ultrashort Laser Pulse Phenomena

CERN Document Server

Diels, Jean-Claude

2006-01-01

Ultrashort Laser Pulse Phenomena, 2e serves as an introduction to the phenomena of ultra short laser pulses and describes how this technology can be used to examine problems in areas such as electromagnetism, optics, and quantum mechanics. Ultrashort Laser Pulse Phenomena combines theoretical backgrounds and experimental techniques and will serve as a manual on designing and constructing femtosecond (""faster than electronics"") systems or experiments from scratch. Beyond the simple optical system, the various sources of ultrashort pulses are presented, again with emphasis on the basic

Multimode pulse counter

International Nuclear Information System (INIS)

Natanzon, D.D.

1982-01-01

A pulse counter with code conversion is described. The counter is based on the integrated circuits of direct-counting devices of medium integration. The counter ensures various modes of pulse counting depending on the logical control signals: reversible, two-channel summing, one-channel summing binary, summing with ''storage'' signal code fixation without interrupting pulse counting. Arrangement of the suggested structure as a microcircuit of medium integration might contribute to reduction in the counter type nomenclature in digital families of widely used integrated circuits

Vienaudžu vardarbība, pašvērtējums un empātija.

OpenAIRE

Krieva, Ilze

2013-01-01

Pētījuma mērķis bija noskaidrot vai pastāv saistība starp vienaudžu vardarbību, pašvērtējumu un empātijas līmeni. Pētījumā piedalījās desmitās un vienpadsmitās klases skolēni, pusaudži vecumā no 15-17 gadiem (n= 50). Pētījumā tika izmantotas šādas metodes: Vardarbības aptauja “Kā tev klājas skolā” (V.Rumpētere, balstoties uz T.Auroras izstrādāto aptauju par dzīvi skolā („The life in School checklist”, Aurora&Thompson, 1987), Pašvērtējuma aptauja (Rosenberg Self-Esteem Scale, Rosenberg,...

THE SYNTHETIC-OVERSAMPLING METHOD: USING PHOTOMETRIC COLORS TO DISCOVER EXTREMELY METAL-POOR STARS

Energy Technology Data Exchange (ETDEWEB)

Miller, A. A., E-mail: amiller@astro.caltech.edu [Jet Propulsion Laboratory, 4800 Oak Grove Drive, MS 169-506, Pasadena, CA 91109 (United States)

2015-09-20

Extremely metal-poor (EMP) stars ([Fe/H] ≤ −3.0 dex) provide a unique window into understanding the first generation of stars and early chemical enrichment of the universe. EMP stars are exceptionally rare, however, and the relatively small number of confirmed discoveries limits our ability to exploit these near-field probes of the first ∼500 Myr after the Big Bang. Here, a new method to photometrically estimate [Fe/H] from only broadband photometric colors is presented. I show that the method, which utilizes machine-learning algorithms and a training set of ∼170,000 stars with spectroscopically measured [Fe/H], produces a typical scatter of ∼0.29 dex. This performance is similar to what is achievable via low-resolution spectroscopy, and outperforms other photometric techniques, while also being more general. I further show that a slight alteration to the model, wherein synthetic EMP stars are added to the training set, yields the robust identification of EMP candidates. In particular, this synthetic-oversampling method recovers ∼20% of the EMP stars in the training set, at a precision of ∼0.05. Furthermore, ∼65% of the false positives from the model are very metal-poor stars ([Fe/H] ≤ −2.0 dex). The synthetic-oversampling method is biased toward the discovery of warm (∼F-type) stars, a consequence of the targeting bias from the Sloan Digital Sky Survey/Sloan Extension for Galactic Understanding survey. This EMP selection method represents a significant improvement over alternative broadband optical selection techniques. The models are applied to >12 million stars, with an expected yield of ∼600 new EMP stars, which promises to open new avenues for exploring the early universe.

Powerful nanosecond pulse train generator

International Nuclear Information System (INIS)

Isakov, I.F.; Logachev, E.I.; Opekunov, M.S.; Pechenkin, S.A.; Remnev, G.E.; Usov, Yu.P.

1987-01-01

A generator permitting to shape on the load pulsed with the repetition frequency of 10 3 -10 6 Hz and more is described. The amplitude of shaped voltage pulses is up to 150 kV at pulse duration equal to 50 ns. The generator comprises connected in-series with the load two shaping and two transmission lines realized on the base of the KVI-300 low-ohmic cable. The shaping lines are supplied from two independently connected pulse voltage generators for obtaining time interval between pulses > 10 -6 s; they may be also supplied from one generator for obtaining time interval -6 s. At the expense of reducing losses in the discharge circuit the amplitude of the second pulse grows with increase of time interval between pulses up to 300 ns, further on the curve flat-topping exists. The described generator is used in high-current accelerators, in which the primary negative pulse results in generation of explosive-emission plasma, and the second positive pulse provides ion beam shaping including ions of heavy metal used for production of a potential electrode. The generator multipulse mode is used for successive ion acceleration in the transport system

RIIM two-pulse injector experiments

International Nuclear Information System (INIS)

Mazarakis, M.G.; Smith, D.L.; Jones, E.E.; Hasti, D.E.; Jojola, J.M.; Lehmann, M.

1987-01-01

The RADLAC-II foilless diode injector was operated under double pulse conditions utilizing the RIIM accelerator as the test bed. The original RIIM accelerator pulse-power network was modified to provide for the generation, transmission, and delivery to the foilless diode of two distinct voltage pulses with variable interpulse separation from 0 to 2 ms. Two pulse-power assemblies were investigated and will be presented in connection with the diode performance. In both cases, the generated plasma and an excessive neutral gas release, following the first pulse, prevented the diode from producing a second beam pulse for interpulse separations larger than ∼1 μs. 4 refs

El conductismo en la ciencia política: descifrando un concepto poco maleable en los horizontes de la investigación empírica

OpenAIRE

John Fredy Bedoya Marulanda

2015-01-01

Este artículo tiene como objetivo revivir el conductismo como una forma derealizar investigación empírica en la ciencia política, haciendo el llamado a lacientificidad de la disciplina con un objeto de estudio específico: elcomportamiento político de los individuos. Desde allí se presenta como sepuede definir el conductismo, sus cánones metodológicos y una aproximación acómo debe entenderse el comportamiento político.

Coiled transmission line pulse generators

Science.gov (United States)

McDonald, Kenneth Fox

2010-11-09

Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

A 70 kV solid-state high voltage pulse generator based on saturable pulse transformer.

Science.gov (United States)

Fan, Xuliang; Liu, Jinliang

2014-02-01

High voltage pulse generators are widely applied in many fields. In recent years, solid-state and operating at repetitive mode are the most important developing trends of high voltage pulse generators. A solid-state high voltage pulse generator based on saturable pulse transformer is proposed in this paper. The proposed generator is consisted of three parts. They are charging system, triggering system, and the major loop. Saturable pulse transformer is the key component of the whole generator, which acts as a step-up transformer and main switch during working process of this generator. The circuit and working principles of the proposed pulse generator are introduced first in this paper, and the saturable pulse transformer used in this generator is introduced in detail. Circuit of the major loop is simulated to verify the design of the system. Demonstration experiments are carried out, and the results show that when the primary energy storage capacitor is charged to a high voltage, such as 2.5 kV, a voltage with amplitude of 86 kV can be achieved on the secondary winding. The magnetic core of saturable pulse transformer is saturated deeply and the saturable inductance of the secondary windings is very small. The switch function of the saturable pulse transformer can be realized ideally. Therefore, a 71 kV output voltage pulse is formed on the load. Moreover, the magnetic core of the saturable pulse transformer can be reset automatically.

High efficiency, monolithic fiber chirped pulse amplification system for high energy femtosecond pulse generation.

Science.gov (United States)

Peng, Xiang; Kim, Kyungbum; Mielke, Michael; Jennings, Stephen; Masor, Gordon; Stohl, Dave; Chavez-Pirson, Arturo; Nguyen, Dan T; Rhonehouse, Dan; Zong, Jie; Churin, Dmitriy; Peyghambarian, N

2013-10-21

A novel monolithic fiber-optic chirped pulse amplification (CPA) system for high energy, femtosecond pulse generation is proposed and experimentally demonstrated. By employing a high gain amplifier comprising merely 20 cm of high efficiency media (HEM) gain fiber, an optimal balance of output pulse energy, optical efficiency, and B-integral is achieved. The HEM amplifier is fabricated from erbium-doped phosphate glass fiber and yields gain of 1.443 dB/cm with slope efficiency >45%. We experimentally demonstrate near diffraction-limited beam quality and near transform-limited femtosecond pulse quality at 1.55 µm wavelength. With pulse energy >100 µJ and pulse duration of 636 fs (FWHM), the peak power is estimated to be ~160 MW. NAVAIR Public Release Distribution Statement A-"Approved for Public release; distribution is unlimited".

Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method

International Nuclear Information System (INIS)

Arbelaez, D.; Madur, A.; Lipton, T.M.; Waldron, W.L.; Kwan, J.W.

2011-01-01

A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 (micro)m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.

Chinese Grand Strategy: How Anti-Access/Area Denial (A2/AD) Fits in China’s Plan

Science.gov (United States)

2014-04-01

ensuing global depression . An electro-magnetic pulse (EMP) attack, from an ICBM, long range cruise missile, or satellite, detonated 400km over the U.S...Philippines, Malaysia , and Brunei all actively disputing some area of the South China Sea. There are several reasons for the intense competition as the area

Perforate on CHO cell membranes induced by electromagnetic ...

African Journals Online (AJOL)

Atomic force microscopy (AFM) has been used to visualize the morphological change on the surface of Chinese hamster ovary (CHO) cell membranes before and after electromagnetic pulses (EMP) irradiation. The results show that there were different sizes and shapes of membrane perforate (width ranging from 0.39 - 0.66 ...

STATUS OF THE LINUX PC CLUSTER FOR BETWEEN-PULSE DATA ANALYSES AT DIII-D

International Nuclear Information System (INIS)

PENG, Q; GROEBNER, R.J; LAO, L.L; SCHACHTER, J.; SCHISSEL, D.P; WADE, M.R.

2001-08-01

OAK-B135 Some analyses that survey experimental data are carried out at a sparse sample rate between pulses during tokamak operation and/or completed as a batch job overnight because the complete analysis on a single fast workstation cannot fit in the narrow time window between two pulses. Scientists therefore miss the opportunity to use these results to guide experiments quickly. With a dedicated Beowulf type cluster at a cost less than that of a workstation, these analyses can be accomplished between pulses and the analyzed data made available for the research team during the tokamak operation. A Linux PC cluster comprises of 12 processors was installed at DIII-D National Fusion Facility in CY00 and expanded to 24 processors in CY01 to automatically perform between-pulse magnetic equilibrium reconstructions using the EFIT code written in Fortran, CER analyses using CERQUICK code written in IDL and full profile fitting analyses (n e , T e , T i , V r , Z eff ) using IDL code ZIPFIT. This paper reports the current status of the system and discusses some problems and concerns raised during the implementation and expansion of the system

Few-cycle isolated attosecond pulses

International Nuclear Information System (INIS)

Sansone, G.; Benedetti, E.; Calegari, F.; Stagira, S.; Vozzi, C.; Silvestri De, S.; Nisoli, M.

2006-01-01

Complete test of publication follows. In the last few years the field of attosecond science has shown impressive and rapid progress, mainly due to the introduction of novel experimental methods for the characterization of extreme ultraviolet (XUV) pulses and attosecond electron wave packets. This development has been also triggered by significant improvements in the control of the electric field of the driving infrared pulses. Particularly interesting for the applications is the generation of isolated attosecond XUV pulses using few-cycle driving pulses. In this case significant progresses have been achieved thanks to the stabilization of the carrier-envelope phase (CEP) of amplified light pulses. In this work we demonstrate that the polarization gating (PG) method with few-cycle phase-stabilized driving pulses allows one to generate few-cycle isolated attosecond pulses tunable on a very broad spectral region. The PG method is based on temporal modulation of the ellipticity of a light pulse, which confines the XUV emission in the temporal gate where the polarization is close to linear. The time-dependent polarization of phase-stabilized sub-6-fs pulses, generated by the hollow fiber technique, has been obtained using two birefringent plates. It is possible to create a linear polarization gate, whose position is imposed by the intensity profile of the pulse whilst the emission time is linked to the CEP of the electric field. The pulses have been analyzed by using a flat-field spectrometer. Continuous XUV spectra, corresponding to the production of isolated attosecond pulses, have been generated for particular CEP values. Upon changing the rotation of the first plate it was possible to tune the XUV emission in a broad spectra range. We have then achieved a complete temporal characterization of the generated isolated attosecond pulses using frequency-resolved optical gating for complete reconstruction of attosecond bursts (FROG CRAB). The measured parabolic phase

Foundations of pulsed power technology

CERN Document Server

Lehr, Janet

2018-01-01

Pulsed power technologies could be an answer to many cutting-edge applications. The challenge is in how to develop this high-power/high-energy technology to fit current market demands of low-energy consuming applications. This book provides a comprehensive look at pulsed power technology and shows how it can be improved upon for the world of today and tomorrow. Foundations of Pulsed Power Technology focuses on the design and construction of the building blocks as well as their optimum assembly for synergetic high performance of the overall pulsed power system. Filled with numerous design examples throughout, the book offers chapter coverage on various subjects such as: Marx generators and Marx-like circuits; pulse transformers; pulse-forming lines; closing switches; opening switches; multi-gigawatt to multi-terawatt systems; energy storage in capacitor banks; electrical breakdown in gases; electrical breakdown in solids, liquids and vacuum; pulsed voltage and current measurements; electromagnetic interferen...

La demanda de trabajo: teoría y evidencia empírica para el caso colombiano

Directory of Open Access Journals (Sweden)

Jairo Guillermo Isaza Castro

2004-07-01

Full Text Available Este documento presenta algunos de los aspectos teóricos más importantes para el análisis de la demanda de trabajo, así como la evidencia empírica disponible para el caso colombiano. En cuanto a los aspectos teóricos, la exposición se centra en la discusión microeonómica concerniente a las propiedades de la demanda de trabajo del empresario maximizador debeneficios que enfrenta un proceso productivo con dos factores: capital y trabajo. Luego se discuten las implicaciones de los procesos de liberalización y reformas estructurales en la demanda de trabajo. La revisión de literatura efectuada para el caso colombiano muestra cómo, en general, los estimativos de elasticidades de la demanda por trabajadores frente al producto y el salario real difieren sustancialmente debido a la diversidad de especificaciones econométricas, la temporalidad de los datos y las fuentes de los mismos.

Do 360-degree feedback survey results relate to patient satisfaction measures?

Science.gov (United States)

Hageman, Michiel G J S; Ring, David C; Gregory, Paul J; Rubash, Harry E; Harmon, Larry

2015-05-01

There is evidence that feedback from 360-degree surveys-combined with coaching-can improve physician team performance and quality of patient care. The Physicians Universal Leadership-Teamwork Skills Education (PULSE) 360 is one such survey tool that is used to assess work colleagues' and coworkers' perceptions of a physician's leadership, teamwork, and clinical practice style. The Clinician & Group-Consumer Assessment of Healthcare Providers and System (CG-CAHPS), developed by the US Department of Health and Human Services to serve as the benchmark for quality health care, is a survey tool for patients to provide feedback that is based on their recent experiences with staff and clinicians and soon will be tied to Medicare-based compensation of participating physicians. Prior research has indicated that patients and coworkers often agree in their assessment of physicians' behavioral patterns. The goal of the current study was to determine whether 360-degree, also called multisource, feedback provided by coworkers could predict patient satisfaction/experience ratings. A significant relationship between these two forms of feedback could enable physicians to take a more proactive approach to reinforce their strengths and identify any improvement opportunities in their patient interactions by reviewing feedback from team members. An automated 360-degree software process may be a faster, simpler, and less resource-intensive approach than telephoning and interviewing patients for survey responses, and it potentially could facilitate a more rapid credentialing or quality improvement process leading to greater fiscal and professional development gains for physicians. Our primary research question was to determine if PULSE 360 coworkers' ratings correlate with CG-CAHPS patients' ratings of overall satisfaction, recommendation of the physician, surgeon respect, and clarity of the surgeon's explanation. Our secondary research questions were to determine whether CG-CAHPS scores

An 8-GW long-pulse generator based on Tesla transformer and pulse forming network.

Science.gov (United States)

Su, Jiancang; Zhang, Xibo; Li, Rui; Zhao, Liang; Sun, Xu; Wang, Limin; Zeng, Bo; Cheng, Jie; Wang, Ying; Peng, Jianchang; Song, Xiaoxin

2014-06-01

A long-pulse generator TPG700L based on a Tesla transformer and a series pulse forming network (PFN) is constructed to generate intense electron beams for the purpose of high power microwave (HPM) generation. The TPG700L mainly consists of a 12-stage PFN, a built-in Tesla transformer in a pulse forming line, a three-electrode gas switch, a transmission line with a trigger, and a load. The Tesla transformer and the compact PFN are the key technologies for the development of the TPG700L. This generator can output electrical pulses with a width as long as 200 ns at a level of 8 GW and a repetition rate of 50 Hz. When used to drive a relative backward wave oscillator for HPM generation, the electrical pulse width is about 100 ns on a voltage level of 520 kV. Factors affecting the pulse waveform of the TPG700L are also discussed. At present, the TPG700L performs well for long-pulse HPM generation in our laboratory.

An 8-GW long-pulse generator based on Tesla transformer and pulse forming network

Energy Technology Data Exchange (ETDEWEB)

Su, Jiancang; Zhang, Xibo; Li, Rui; Zhao, Liang, E-mail: zhaoliang0526@163.com; Sun, Xu; Wang, Limin; Zeng, Bo; Cheng, Jie; Wang, Ying; Peng, Jianchang; Song, Xiaoxin [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi' an, Shaanxi 710024 (China)

2014-06-15

A long-pulse generator TPG700L based on a Tesla transformer and a series pulse forming network (PFN) is constructed to generate intense electron beams for the purpose of high power microwave (HPM) generation. The TPG700L mainly consists of a 12-stage PFN, a built-in Tesla transformer in a pulse forming line, a three-electrode gas switch, a transmission line with a trigger, and a load. The Tesla transformer and the compact PFN are the key technologies for the development of the TPG700L. This generator can output electrical pulses with a width as long as 200 ns at a level of 8 GW and a repetition rate of 50 Hz. When used to drive a relative backward wave oscillator for HPM generation, the electrical pulse width is about 100 ns on a voltage level of 520 kV. Factors affecting the pulse waveform of the TPG700L are also discussed. At present, the TPG700L performs well for long-pulse HPM generation in our laboratory.

Pulse pile-up IV

International Nuclear Information System (INIS)

Wilkinson, D.H.

1991-05-01

The study of pulse pile-up is extended from the case of unipolar pulses, for which ruin theory is an excellent approximation, to the case of bipolar pulses for which ruin theory is not applicable to the effect of the back-kicks in reducing the pile-up: an appropriate solution is presented. (Author) 3 refs., 11 figs

English-Medium Programmes at Austrian Business Faculties: A Status Quo Survey on National Trends and a Case Study on Programme Design and Delivery

Science.gov (United States)

Unterberger, Barbara

2012-01-01

Internationalisation processes have accelerated the implementation of English-medium programmes (EMPs) across European higher education institutions. The field of business and management studies has been particularly affected by this trend (Wachter & Maiworm 2008: 46) with numerous new EMPs introduced each year. This paper presents key…

Un análisis empírico de las no linealidades en la movilidad intergeneracional del ingreso. El caso de la Argentina

OpenAIRE

Jiménez, Maribel

2017-01-01

El principal objetivo de este estudio es cuantificar y examinar la movilidad intergeneracional del ingreso en la Argentina, explorando la hipótesis de variación del grado de (in)movilidad a lo largo de la distribución del ingreso correspondiente a los hijos así como a los padres, a través de la aplicación de métodos econométricos utilizados en la literatura empírica reciente para datos no longitudinales. Los resultados, obtenidos a partir de la información proveniente de dos muestras de la En...

Un análisis empírico de las no linealidades en la movilidad intergeneracional del ingreso : El caso de la Argentina

OpenAIRE

Jiménez, Maribel

2010-01-01

El principal objetivo de este estudio es cuantificar y examinar la movilidad intergeneracional del ingreso en la Argentina, explorando la hipótesis de variación del grado de (in)movilidad a lo largo de la distribución del ingreso correspondiente a los hijos así como a los padres, a través de la aplicación de métodos econométricos utilizados en la literatura empírica reciente para datos no longitudinales. Los resultados, obtenidos a partir de la información proveniente de dos muestras de la En...

Development of aerial gamma radiation survey system, 1

International Nuclear Information System (INIS)

Tsutsumi, Masahiro; Saito, Komei; Sakamoto, Ryuichi; Nagaoka, Toshi; Moriuchi, Shigeru

1986-05-01

JAERI has started to develop an aerial gamma radiation survey system by a helicopter in 1980. The development of measuring instruments, the experiments in the field of natural and artificial radiation sources, and the imaginary emergency survey at a real site, were executed. This report describes mainly about the hardware and software of this system. The system consists of gamma-ray measuring instruments with NaI(Tl) scintillation detectors, microwave positioning instruments, and a data processing system for postflight data. A foreign-made geological survey system is improved on for radiation measurements. For covering the wide radiation range, detectors of various shapes and sizes are prepared, from a large volume detector, DET-1024 - four 4'' x 4'' x 16'' crystals assembly - to a 2'' diameter x 2'' NaI(Tl) crystal. Radiation and position data are recorded on a magnetic tape, and computer-processed afterwards. Moreover, scene below flight courses and internal communication are recorded on video tape with the information of clock and position superimposed. In consequence of field experiments carried out five times, basic radiation data for evaluating airborne acquired data are accumulated, and flight survey procedures are established. As more practical use, a system has been produced more compactly and functionally. Exposure rates (> 1 mR/h), energy distribution spectra, and energy window counts are obtained for radiation data. Using the Spectrum-Dose Conversion Method, the accurate exposure rates are directly calculated from pulse height spectra. Numerical tables of G(E) function converting pulse height spectra into exposures are shown in this report. As regards the analysis of survey data, process codes have been completed with either large-computer or mini-computer. (author)

Application of nonlinear pulse shaping of femtosecond pulse generation in a fiber amplifier at 500 MHz repetition rate

Science.gov (United States)

Liu, Yang; Luo, Daping; Wang, Chao; Zhu, Zhiwei; Li, Wenxue

2018-03-01

We numerically and experimentally demonstrate that a nonlinear pulse shaping technique based on pre-chirping management in a short gain fiber can be exploited to improve the quality of a compressed pulse. With prior tuning of the pulse chirp, the amplified pulse express different nonlinear propagating processes. A spectrum with s flat top and more smooth wings, showing a similariton feature, generates with the optimal initial pulse chirp, and the shortest pulses with minimal pulse pedestals are obtained. Experimental results show the ability of nonlinear pulse shaping to enhance the quality of compressed pulses, as theoretically expected.

Nanosecond bipolar pulse generators for bioelectrics.

Science.gov (United States)

Xiao, Shu; Zhou, Chunrong; Yang, Enbo; Rajulapati, Sambasiva R

2018-04-26

Biological effects caused by a nanosecond pulse, such as cell membrane permeabilization, peripheral nerve excitation and cell blebbing, can be reduced or cancelled by applying another pulse of reversed polarity. Depending on the degree of cancellation, the pulse interval of these two pulses can be as long as dozens of microseconds. The cancellation effect diminishes as the pulse duration increases. To study the cancellation effect and potentially utilize it in electrotherapy, nanosecond bipolar pulse generators must be made available. An overview of the generators is given in this paper. A pulse forming line (PFL) that is matched at one end and shorted at the other end allows a bipolar pulse to be produced, but no delay can be inserted between the phases. Another generator employs a combination of a resistor, an inductor and a capacitor to form an RLC resonant circuit so that a bipolar pulse with a decaying magnitude can be generated. A third generator is a converter, which converts an existing unipolar pulse to a bipolar pulse. This is done by inserting an inductor in a transmission line. The first phase of the bipolar pulse is provided by the unipolar pulse's rising phase. The second phase is formed during the fall time of the unipolar pulse, when the inductor, which was previously charged during the flat part of the unipolar pulse, discharges its current to the load. The fourth type of generator uses multiple MOSFET switches stacked to turn on a pre-charged, bipolar RC network. This approach is the most flexible in that it can generate multiphasic pulses that have different amplitudes, delays, and durations. However, it may not be suitable for producing short nanosecond pulses (<100 ns), whereas the PFL approach and the RLC approach with gas switches are used for this range. Thus, each generator has its own advantages and applicable range. Copyright © 2018 Elsevier B.V. All rights reserved.

Industrial Applications of Pulsed Power Technology

Science.gov (United States)

Takaki, Koichi; Katsuki, Sunao

Recent progress of the industrial applications of pulsed power is reviewed in this paper. Repetitively operated pulsed power generators with a moderate peak power have been developed for industrial applications. These generators are reliable and low maintenance. Development of the pulsed power generators helps promote industrial applications of pulsed power for such things as food processing, medical treatment, water treatment, exhaust gas treatment, ozone generation, engine ignition, ion implantation and others. Here, industrial applications of pulsed power are classified by application for biological effects, for pulsed streamer discharges in gases, for pulsed discharges in liquid or liquid-mixture, and for bright radiation sources.

Linear induction accelerators made from pulse-line cavities with external pulse injection

International Nuclear Information System (INIS)

Smith, I.

1979-01-01

Two types of linear induction accelerator have been reported previously. In one, unidirectional voltage pulses are generated outside the accelerator and injected into the accelerator cavity modules, which contain ferromagnetic material to reduce energy losses in the form of currents induced, in parallel with the beam, in the cavity structure. In the other type, the accelerator cavity modules are themselves pulse-forming lines with energy storage and switches; parallel current losses are made zero by the use of circuits that generate bidirectional acceleration waveforms with a zero voltage-time integral. In a third type of design described here, the cavities are externally driven, and 100% efficient coupling of energy to the beam is obtained by designing the external pulse generators to produce bidirectional voltage waveforms with zero voltage-time integral. A design for such a pulse generator is described that is itself one hundred percent efficient and which is well suited to existing pulse power techniques. Two accelerator cavity designs are described that can couple the pulse from such a generator to the beam; one of these designs provides voltage doubling. Comparison is made between the accelerating gradients that can be obtained with this and the preceding types of induction accelerator

Resiliencia en Enfermería: definición, evidencia empírica e intervenciones

Directory of Open Access Journals (Sweden)

Óscar Arrogante

2015-12-01

Full Text Available La resiliencia (adaptación positiva a la adversidad se encuentra dentro de las competencias enfermeras al relacionarse con tres diagnósticos de la taxonomía NANDA y, además, la investigación enfermera señala que es una característica propia de la Enfermería. Sin embargo, la resiliencia es un concepto novedoso para la mayoría de las enfermeras. El artículo tiene como objetivos definir el concepto de resiliencia, exponer la evidencia empírica encontrada en la investigación enfermera y describir los principales programas e intervenciones para su desarrollo. La resiliencia tiene importantes implicaciones clínicas tanto para el cuidado de pacientes, como para el propio autocuidado de la Enfermería. La resiliencia se puede considerar como una característica esencial e inherente a la Enfermería debido a la exposición continua al sufrimiento humano y a unas condiciones laborales estresantes. Por lo tanto, su entrenamiento debería promoverse desde las universidades hasta los centros sanitarios para mejorar la práctica clínica enfermera.

Optimal filter bandwidth for pulse oximetry

Science.gov (United States)

Stuban, Norbert; Niwayama, Masatsugu

2012-10-01

Pulse oximeters contain one or more signal filtering stages between the photodiode and microcontroller. These filters are responsible for removing the noise while retaining the useful frequency components of the signal, thus improving the signal-to-noise ratio. The corner frequencies of these filters affect not only the noise level, but also the shape of the pulse signal. Narrow filter bandwidth effectively suppresses the noise; however, at the same time, it distorts the useful signal components by decreasing the harmonic content. In this paper, we investigated the influence of the filter bandwidth on the accuracy of pulse oximeters. We used a pulse oximeter tester device to produce stable, repetitive pulse waves with digitally adjustable R ratio and heart rate. We built a pulse oximeter and attached it to the tester device. The pulse oximeter digitized the current of its photodiode directly, without any analog signal conditioning. We varied the corner frequency of the low-pass filter in the pulse oximeter in the range of 0.66-15 Hz by software. For the tester device, the R ratio was set to R = 1.00, and the R ratio deviation measured by the pulse oximeter was monitored as a function of the corner frequency of the low-pass filter. The results revealed that lowering the corner frequency of the low-pass filter did not decrease the accuracy of the oxygen level measurements. The lowest possible value of the corner frequency of the low-pass filter is the fundamental frequency of the pulse signal. We concluded that the harmonics of the pulse signal do not contribute to the accuracy of pulse oximetry. The results achieved by the pulse oximeter tester were verified by human experiments, performed on five healthy subjects. The results of the human measurements confirmed that filtering out the harmonics of the pulse signal does not degrade the accuracy of pulse oximetry.

SLAC pulsed X-ray facility

Science.gov (United States)

Ipe, N. E.; McCall, R. C.; Baker, E. D.

1986-05-01

The Stanford Linear Accelerator Center (SLAC) operates a high energy (up to 33 GeV) linear accelerator delivering pulses up to a few microseconds wide. The pulsed nature of the electron beam creates problems in the detection and measurement of radiation both from the accelerator beam and the klystrons that provide the RF power for the accelerator. Hence, a pulsed X-ray facility has been built at SLAC mainly for the purpose of testing the response of different radiation detection instruments to pulsed radiation fields. The X-ray tube consists of an electron gun with a control grid. This provides a stream of pulsed electrons that can be accelerated towards a confined target-window. The window is made up of aluminum 0.051 cm (20 mils) thick, plated on the vacuum side with a layer of gold 0.0006 cm (1/4 mil) thick. The frequency of electron pulses can be varied by an internal pulser from 60 to 360 pulses per second with pulse widths of 360 ns to 5 ms. The pulse amplitude can be varied over a wide range of currents. An external pulser can be used to obtain other frequencies or special pulse shapes. The voltage across the gun can be varied from 0 to 100 kV. The major part of the X-ray tube is enclosed in a large walk-in-cabinet made of 1.9 cm (3/4 in) plywood and lined with 0.32 cm (1/8 in) lead to make a very versatile facility.

SLAC pulsed x-ray facility

International Nuclear Information System (INIS)

Ipe, N.E.; McCall, R.C.; Baker, E.D.

1986-05-01

The Stanford Linear Accelerator Center (SLAC) operates a high energy (up to 33 GeV) linear accelerator delivering pulses up to a few microseconds wide. The pulsed nature of the electron beam creates problems in the detection and measurement of radiation both from the accelerator beam and the klystrons that provide the rf power for the accelerator. Hence, a pulsed x-ray facility has been built at SLAC mainly for the purpose of testing the response of different radiation detection instruments to pulsed radiation fields. The x-ray tube consists of an electron gun with a control grid. This provides a stream of pulsed electrons that can be accelerated towards a confined target-window. The window is made up of aluminium 0.051 cm (20 mils) thick, plated on the vacuum side with a layer of gold 0.0006 cm (1/4 mil) thick. The frequency of electron pulses can be varied by an internal pulser from 60 to 360 pulses per second with pulse widths of 360 ns to 5 μs. The pulse amplitude can be varied over a wide range of currents. An external pulser can be used to obtain other frequencies or special pulse shapes. The voltage across the gun can be varied from 0 to 100 kV. The major part of the x-ray tube is enclosed in a large walk-in-cabinet made of 1.9 cm (3/4 in) plywood and lined with 0.32 cm (1/8 in) lead to make a very versatile facility. 3 refs., 5 figs

Effects of laser wavelengths and pulse energy ratio on the emission enhancement in dual pulse LIBS

International Nuclear Information System (INIS)

Ahmed, Rizwan; Iqbal, Javed; Baig, M Aslam

2015-01-01

We present new studies on the effects of laser wavelengths, pulse energy ratio and interpulse delay between two laser pulses in the collinear dual pulse configuration of laser-induced breakdown spectroscopy (LIBS) on an iron sample in air using the fundamental (1064 nm) and the second harmonics (532 nm) of Nd:YAG lasers. In the dual pulse LIBS, an optimum value of interpulse delay with an appropriate combination of laser wavelengths, and laser pulse energy ratio, yields a 30 times signal intensity enhancement in the neutral iron lines as compared with single pulse LIBS. A comparison in the spatial variations of electron temperature along the axis of the plume expansion in single and double pulse LIBS has also been studied. (letter)

Ultrashort X-ray pulse science

Energy Technology Data Exchange (ETDEWEB)

Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

1998-05-01

A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90° Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ~ 300 fs, 30 keV (0.4 Å) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been demonstrated as a

Ultrashort X-ray pulse science

International Nuclear Information System (INIS)

Chin, A.H.; Lawrence Berkeley National Lab., CA

1998-01-01

A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90 o Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ∼ 300 fs, 30 keV (0.4 (angstrom)) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been

Phylloquinone (vitamin K₁) intake and pulse pressure as a measure of arterial stiffness in older adults.

Science.gov (United States)

Vaccaro, Joan A; Huffman, Fatma G

2013-01-01

This study examined the relationships among ethnicity/race, lifestyle factors, phylloquinone (vitamin K₁) intake, and arterial pulse pressure in a nationally representative sample of older adults from four ethnic/racial groups: non-Hispanic Whites, non-Hispanic Blacks, Mexican Americans, and other Hispanics. This was a cross-sectional study of U.S. representative sample with data from the National Health and Nutrition Examination Surveys, 2007-2008 and 2009-2010 of adults aged 50 years and older (N = 5296). Vitamin K intake was determined by 24-hour recall. Pulse pressure was calculated as the difference between the averages of systolic blood pressure and diastolic blood pressure. Compared to White non-Hispanics, the other ethnic/racial groups were more likely to have inadequate vitamin K₁ intake. Inadequate vitamin K₁ intake was an independent predictor of high arterial pulse pressure. This was the first study that compared vitamin K₁ inadequacy with arterial pulse pressure across ethnicities/races in U.S. older adults. These findings suggest that vitamin K screening may be a beneficial marker for the health of older adults.

Pulse-width discriminators

International Nuclear Information System (INIS)

Budyashov, Yu.G.; Grebenyuk, V.M.; Zinov, V.G.

1978-01-01

A pulse duration discriminator is described which is intended for processing signals from multilayer scintillators. The basic elements of the scintillator are: an input gate, a current generator, an integrating capacitor, a Schmidt trigger and an anticoincidence circuit. The basic circuit of the discriminator and its time diagrams explaining its operating are given. The discriminator is based on microcircuits. Pulse duration discrimination threshold changes continuously from 20 to 100 ns, while its amplitude threshold changes within 20 to 100 mV. The temperature instability of discrimination thresholds (both in pulse width and in amplitude) is better than 0.1 per cent/deg C

A compact high-voltage pulse generator based on pulse transformer with closed magnetic core.

Science.gov (United States)

Zhang, Yu; Liu, Jinliang; Cheng, Xinbing; Bai, Guoqiang; Zhang, Hongbo; Feng, Jiahuai; Liang, Bo

2010-03-01

A compact high-voltage nanosecond pulse generator, based on a pulse transformer with a closed magnetic core, is presented in this paper. The pulse generator consists of a miniaturized pulse transformer, a curled parallel strip pulse forming line (PFL), a spark gap, and a matched load. The innovative design is characterized by the compact structure of the transformer and the curled strip PFL. A new structure of transformer windings was designed to keep good insulation and decrease distributed capacitance between turns of windings. A three-copper-strip structure was adopted to avoid asymmetric coupling of the curled strip PFL. When the 31 microF primary capacitor is charged to 2 kV, the pulse transformer can charge the PFL to 165 kV, and the 3.5 ohm matched load can deliver a high-voltage pulse with a duration of 9 ns, amplitude of 84 kV, and rise time of 5.1 ns. When the load is changed to 50 ohms, the output peak voltage of the generator can be 165 kV, the full width at half maximum is 68 ns, and the rise time is 6.5 ns.

Enhancement of beam pulse controllability for a single-pulse formation system of a cyclotron

International Nuclear Information System (INIS)

Kurashima, Satoshi; Miyawaki, Nobumasa; Kashiwagi, Hirotsugu; Okumura, Susumu; Taguchi, Mitsumasa; Fukuda, Mitsuhiro

2015-01-01

The single-pulse formation technique using a beam chopping system consisting of two types of high-voltage beam kickers was improved to enhance the quality and intensity of the single-pulse beam with a pulse interval over 1 μs at the Japan Atomic Energy Agency cyclotron facility. A contamination rate of neighboring beam bunches in the single-pulse beam was reduced to less than 0.1%. Long-term purification of the single pulse beam was guaranteed by the well-controlled magnetic field stabilization system for the cyclotron magnet. Reduction of the multi-turn extraction number for suppressing the neighboring beam bunch contamination was achieved by restriction of a beam phase width and precise optimization of a particle acceleration phase. In addition, the single-pulse beam intensity was increased by a factor of two or more by a combination of two types of beam bunchers using sinusoidal and saw-tooth voltage waveforms. Provision of the high quality intense single-pulse beam contributed to improve the accuracy of experiments for investigation of scintillation light time-profile and for neutron energy measurement by a time-of-flight method

The purpose for GEO spacecraft deep charging and electrostatic discharging (ESD) experiment

International Nuclear Information System (INIS)

Yang Chuibai; Wang Shijin; Liang Jinbao

2005-01-01

This paper introduces the purpose for GEO spacecraft deep charging and electrostatic discharging (ESD) experiment. A method of experiment for the spacecraft deep charging and ESD aboard is proposed. Spacecraft deep charging and ESD event, frequency, energy and the level of pulse in wires due to EMP coupling into are measured. (authors)

Hyper dispersion pulse compressor for chirped pulse amplification systems

Science.gov (United States)

Barty, Christopher P. J.

2011-11-29

A grating pulse compressor configuration is introduced for increasing the optical dispersion for a given footprint and to make practical the application for chirped pulse amplification (CPA) to quasi-narrow bandwidth materials, such as Nd:YAG. The grating configurations often use cascaded pairs of gratings to increase angular dispersion an order of magnitude or more. Increased angular dispersion allows for decreased grating separation and a smaller compressor footprint.

Pulse duration discriminator

International Nuclear Information System (INIS)

Kosakovskij, L.F.

1980-01-01

Basic circuits of a discriminator for discrimination of pulses with the duration greater than the preset one, and of a multifunctional discriminator allowing to discriminate pulses with the duration greater (tsub(p)>tsub(s)) and lesser (tsub(p) tsub(s) and with the duration tsub(p) [ru

Effect of rising time of rectangular pulse on inactivation of staphylococcus aureus by pulsed electric field

Science.gov (United States)

Zhang, Ruobing; Liang, Dapeng; Zheng, Nanchen; Xiao, Jianfu; Mo, Mengbin; Li, Jing

2013-03-01

Pulsed electric field (PEF) is a novel non-thermal food processing technology that involves the electric discharge of high voltage short pulses through the food product. In PEF study, rectangular pulses are most commonly used for inactivating microorganisms. However, little information is available on the inactivation effect of rising time of rectangular pulse. In this paper, inactivation effects, electric field strength, treatment time and conductivity on staphylococcus aureus inactivation were investigated when the pulse rising time is reduced from 2.5 μs to 200 ns. Experimental results showed that inactivation effect of PEF increased with electric field strength, solution conductivity and treatment time. Rising time of the rectangular pulse had a significant effect on the inactivation of staphylococcus aureus. Rectangular pulses with a rising time of 200 ns had a better inactivation effect than that with 2 μs. In addition, temperature increase of the solution treated by pulses with 200 ns rising time was lower than that with 2 μs. In order to obtain a given inactivation effect, treatment time required for the rectangular pulse with 200 ns rise time was shorter than that with 2 μs.

Effect of rising time of rectangular pulse on inactivation of staphylococcus aureus by pulsed electric field

International Nuclear Information System (INIS)

Zhang, Ruobing; Liang, Dapeng; Xiao, Jianfu; Mo, Mengbin; Li, Jing; Zheng, Nanchen

2013-01-01

Pulsed electric field (PEF) is a novel non-thermal food processing technology that involves the electric discharge of high voltage short pulses through the food product. In PEF study, rectangular pulses are most commonly used for inactivating microorganisms. However, little information is available on the inactivation effect of rising time of rectangular pulse. In this paper, inactivation effects, electric field strength, treatment time and conductivity on staphylococcus aureus inactivation were investigated when the pulse rising time is reduced from 2.5 μs to 200 ns. Experimental results showed that inactivation effect of PEF increased with electric field strength, solution conductivity and treatment time. Rising time of the rectangular pulse had a significant effect on the inactivation of staphylococcus aureus. Rectangular pulses with a rising time of 200 ns had a better inactivation effect than that with 2 μs. In addition, temperature increase of the solution treated by pulses with 200 ns rising time was lower than that with 2 μs. In order to obtain a given inactivation effect, treatment time required for the rectangular pulse with 200 ns rise time was shorter than that with 2 μs.

Pile-up and defective pulse rejection by pulse shape discrimination in surface barrier detectors

International Nuclear Information System (INIS)

Sjoeland, K.A.; Kristiansson, P.

1994-01-01

A technique to reject pile-up pulses and defective tail pulses from surface barrier detectors by the use of pulse shape discrimination is demonstrated. The electronic implementation of the pulse shape discrimination is based upon the zero crossing technique and for data reduction multiparameter techniques are used. The characteristic τ value for pile-up rejection is shown to be less than 56 ns. Its effect on detection limits from tail reduction in Particle Elastic Scattering Analysis (PESA) and pile-up peak suppression is discussed. ((orig.))

CAMAC differential pulse discriminator-counter

International Nuclear Information System (INIS)

Tselikov, N.V.

1987-01-01

Differential pulse discriminator-counter for Moessbauer spectrometer is described. Input pulse setting into the channel is performed according to the following algorithm: the pulse is transmitted to the channel depending on the fact whether the preceding pulse has got to the discrimination window or not. The circuit does not contain delay lines, taking into account the delay of a signal from the upper level discriminator in relation to the lower level discriminator signal, which is connected with input pulse rise finite time, which in turn allows one to reduce the discriminator dead time up to the operation time of threshold circuits. The pulse counting rate is 150 MHz, input signal amplitude is ±3 V, dead time is 6 ns, delay time from input to output is 14 ns. The unit is made in CAMAC system

Sequentially pulsed traveling wave accelerator

Science.gov (United States)

Caporaso, George J [Livermore, CA; Nelson, Scott D [Patterson, CA; Poole, Brian R [Tracy, CA

2009-08-18

A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

Dose rate effect on micronuclei induction in human blood lymphocytes exposed to single pulse and multiple pulses of electrons.

Science.gov (United States)

Acharya, Santhosh; Bhat, N N; Joseph, Praveen; Sanjeev, Ganesh; Sreedevi, B; Narayana, Y

2011-05-01

The effects of single pulses and multiple pulses of 7 MV electrons on micronuclei (MN) induction in cytokinesis-blocked human peripheral blood lymphocytes (PBLs) were investigated over a wide range of dose rates per pulse (instantaneous dose rate). PBLs were exposed to graded doses of 2, 3, 4, 6, and 8 Gy of single electron pulses of varying pulse widths at different dose rates per pulse, ranging from 1 × 10(6) Gy s(-1) to 3.2 × 10(8) Gy s(-1). Different dose rates per pulse were achieved by changing the dose per electron pulse by adjusting the beam current and pulse width. MN yields per unit absorbed dose after irradiation with single electron pulses were compared with those of multiple pulses of electrons. A significant decrease in the MN yield with increasing dose rates per pulse was observed, when dose was delivered by a single electron pulse. However, no reduction in the MN yield was observed when dose was delivered by multiple pulses of electrons. The decrease in the yield at high dose rates per pulse suggests possible radical recombination, which leads to decreased biological damage. Cellular response to the presence of very large numbers of chromosomal breaks may also alter the damage.

Rapid thermal pulse annealing

International Nuclear Information System (INIS)

Miller, M.G.; Koehn, B.W.; Chaplin, R.L.

1976-01-01

Characteristics of recovery processes have been investigated for cases of heating a sample to successively higher temperatures by means of isochronal annealing or by using a rapid pulse annealing. A recovery spectra shows the same features independent of which annealing procedure is used. In order to determine which technique provides the best resolution, a study was made of how two independent first-order processes are separated for different heating rates and time increments of the annealing pulses. It is shown that the pulse anneal method offers definite advantages over isochronal annealing when annealing for short time increments. Experimental data by means of the pulse anneal techniques are given for the various substages of stage I of aluminium. (author)

Linear transformer driver for pulse generation

Science.gov (United States)

Kim, Alexander A; Mazarakis, Michael G; Sinebryukhov, Vadim A; Volkov, Sergey N; Kondratiev, Sergey S; Alexeenko, Vitaly M; Bayol, Frederic; Demol, Gauthier; Stygar, William A

2015-04-07

A linear transformer driver includes at least one ferrite ring positioned to accept a load. The linear transformer driver also includes a first power delivery module that includes a first charge storage devices and a first switch. The first power delivery module sends a first energy in the form of a first pulse to the load. The linear transformer driver also includes a second power delivery module including a second charge storage device and a second switch. The second power delivery module sends a second energy in the form of a second pulse to the load. The second pulse has a frequency that is approximately three times the frequency of the first pulse. The at least one ferrite ring is positioned to force the first pulse and the second pulse to the load by temporarily isolating the first pulse and the second pulse from an electrical ground.

Harmonic generation with a dual frequency pulse.

Science.gov (United States)

Keravnou, Christina P; Averkiou, Michalakis A

2014-05-01

Nonlinear imaging was implemented in commercial ultrasound systems over the last 15 years offering major advantages in many clinical applications. In this work, pulsing schemes coupled with a dual frequency pulse are presented. The pulsing schemes considered were pulse inversion, power modulation, and power modulated pulse inversion. The pulse contains a fundamental frequency f and a specified amount of its second harmonic 2f. The advantages and limitations of this method were evaluated with both acoustic measurements of harmonic generation and theoretical simulations based on the KZK equation. The use of two frequencies in a pulse results in the generation of the sum and difference frequency components in addition to the other harmonic components. While with single frequency pulses, only power modulation and power modulated pulse inversion contained odd harmonic components, with the dual frequency pulse, pulse inversion now also contains odd harmonic components.

New neutron imaging using pulsed sources. Characteristics of a pulsed neutron source and principle of pulsed neutron imaging

International Nuclear Information System (INIS)

Kiyanagi, Yoshiaki

2012-01-01

Neutron beam is one of important tools to obtain the transmission image of an object. Until now, steady state neutron sources such as reactors are mainly used for this imaging purpose. Recently, it has been demonstrated that pulsed neutron imaging based on accelerator neutron sources can provide a real-space distribution of physical information of materials such as crystallographic structure, element, temperature, hydrogen bound state, magnetic field and so on, by analyzing wavelength dependent transmission spectrum, which information cannot be observed or difficult to obtain with a traditional imaging method using steady state neutrons. Here, characteristics of the pulsed neutron source and principle of the pulsed neutron imaging are explained as a basic concept of the new method. (author)

Development of ultra-short high voltage pulse technology using magnetic pulse compression

Energy Technology Data Exchange (ETDEWEB)

Cha, Byung Heon; Kim, S. G.; Nam, S. M.; Lee, B. C.; Lee, S. M.; Jeong, Y. U.; Cho, S. O.; Jin, J. T.; Choi, H. L

1998-01-01

The control circuit for high voltage switches, the saturable inductor for magnetic assist, and the magnetic pulse compression circuit were designed, constructed, and tested. The core materials of saturable inductors in magnetic pulse compression circuit were amorphous metal and ferrite and total compression stages were 3. By the test, in high repetition rate, high pulse compression were certified. As a result of this test, it became possible to increase life-time of thyratrons and to replace thyratrons by solid-state semiconductor switches. (author). 16 refs., 16 tabs.

Development of ultra-short high voltage pulse technology using magnetic pulse compression

International Nuclear Information System (INIS)

Cha, Byung Heon; Kim, S. G.; Nam, S. M.; Lee, B. C.; Lee, S. M.; Jeong, Y. U.; Cho, S. O.; Jin, J. T.; Choi, H. L.

1998-01-01

The control circuit for high voltage switches, the saturable inductor for magnetic assist, and the magnetic pulse compression circuit were designed, constructed, and tested. The core materials of saturable inductors in magnetic pulse compression circuit were amorphous metal and ferrite and total compression stages were 3. By the test, in high repetition rate, high pulse compression were certified. As a result of this test, it became possible to increase life-time of thyratrons and to replace thyratrons by solid-state semiconductor switches. (author). 16 refs., 16 tabs

<3> OMEGA pulse-forming network

CERN Multimedia

1974-01-01

Adjustement of the 3 W pulse-forming network of the SPS beam dumping system. When charged at 60 kV, this PFN gives 10 kA, 25 ms current pulses, with oscillations, superimposed on the pulse flat top, of an amplitude of +/- 1 Ka.

Software emulator of nuclear pulse generation with different pulse shapes and pile-up

Energy Technology Data Exchange (ETDEWEB)

Pechousek, Jiri, E-mail: jiri.pechousek@upol.cz [Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 1192/12, 771 46 Olomouc (Czech Republic); Konecny, Daniel [Department of Optics, Faculty of Science, Palacky University, 17. listopadu 1192/12, 77 146 Olomouc (Czech Republic); Novak, Petr; Kouril, Lukas; Kohout, Pavel [Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 1192/12, 771 46 Olomouc (Czech Republic); Celiktas, Cuneyt [Department of Physics, Faculty of Science, Ege University, Bornova, Izmir (Turkey); Vujtek, Milan [Department of Experimental Physics, Faculty of Science, Palacky University, 17. listopadu 1192/12, 771 46 Olomouc (Czech Republic)

2016-08-21

The optimal detection of output signals from nuclear counting devices represents one of the key physical factors that govern accuracy and experimental reproducibility. In this context, the fine calibration of the detector under diverse experimental scenarios, although time costly, is necessary. However this process can be rendered easier with the use of systems that work in lieu of emulators. In this report we describe an innovative programmable pulse generator device capable to emulate the scintillation detector signals, in a way to mimic the detector performances under a variety of experimental conditions. The emulator generates a defined number of pulses, with a given shape and amplitude in the form of a sampled detector signal. The emulator output is then used off-line by a spectrometric system in order to set up its optimal performance. Three types of pulse shapes are produced by our device, with the possibility to add noise and pulse pile-up effects into the signal. The efficiency of the pulse detection, pile-up rejection and/or correction, together with the dead-time of the system, are therein analyzed through the use of some specific algorithms for pulse processing, and the results obtained validate the beneficial use of emulators for the accurate calibration process of spectrometric systems.

Supercoherent phenomena in pulsed power

International Nuclear Information System (INIS)

O'Rourke, R.C.

1983-01-01

This chapter proposes the formulation of programs of basic physics research to transform Pulsed Power Technology (PPT) to Pulsed Power Science and Technology (PPS and T) by formulating the laws of the quantized microscopic electromagnetic field; applying the microscopic electromagnetic field theory to the generation, propagation and deposition of pulses in nonlinear networks; learning more about the basic super coherent ''micro-structure'' in space and time of the many-photon states of pulsed laser beams; learning more about the basic super coherent ''micro-structure'' in space and time of the many-electronstates of pulsed electron and ion laser beams; and learning everything about the ''micro-picture'' of so-called ''dielectric breakdown'' and the associated absolute time delays. Promotes the idea that laser, electron and ion beams are similar kinds of pulses in the microscopic electromagnetic field. Presents expression for the microscopic electromagnetic field in order to show the role of supercoherence in PPS and T

Pulse plating

CERN Document Server

Hansal, Wolfgang E G; Green, Todd; Leisner, Peter; Reichenbach, Andreas

2012-01-01

The electrodeposition of metals using pulsed current has achieved practical importance in recent years. Although it has long been known that changes in potential, with or without polarity reversal, can significantly affect the deposition process, the practical application of this has been slow to be adopted. This can largely be explained in terms of the complex relationship between the current regime and its effect on the electrodeposition process. In order to harness these effects, an understanding of the anodic and cathodic electrochemical processes is necessary, together with the effects of polarity reversal and the rate of such reversals. In this new monograph, the basics of metal electrodeposition from solution are laid out in great detail in seven distinct chapters. With this knowledge, the reader is able to predict how a given pulse train profile can be adopted to achieve a desired outcome. Equally important is the choice of a suitable rectifier and the ancillary control circuits to enable pulse platin...

Laser-pulsed relativistic electron gun

International Nuclear Information System (INIS)

Sherman, N.K.

1986-01-01

A relativistic (β ≅ 0.8) electron gun with good emittance and subnanosecond pulse duration which can be synchronized to picosecond laser pulses is being developed at NRC for use in studies of particle acceleration by lasers. Bursts of electron pulses exceeding 280 keV in energy have been extracted into air form a laser-driven vacuum photodiode. Trains of 5 ps pulses of ultraviolet UV light illuminate a magnesium cathode. Photoelectrons emitted from the cathode are accelerated in a graded electrostatic potential set up by a 360 kV Marx-generator. The UV pulses are obtained by doubling the frequency of a 606 nm dye laser modelocked at 160 MHz. Electron energies were measured by residual range in an echelon of Al foils. Total charge per burst was measured by picoammeter. Time structure of the bursts has been examined with plastic scintillator and a fast photomultiplier. Tests on a low voltage photodiode achieved a current density of 180 A/cm/sup 2/ from an Mg cathode, with quantum efficiency of 2.4 x 10/sup -6/ electron per UV photon. The brevity and intensity of the laser pulses cause the electric charge collected per pulse to increase linearly with bias voltage rather than according to the Langmuir-Child law. Gun emittance is about 150 mm-msr and beam brightness is about 1A/cm/sup 2/-sr. Estimated duration of individual electron pulses of a burst is about 400 ps with instantaneous current of about 0.1 mA. Energy spread within one pulse is expected to be about 15%. This gun has the potential to be a useful source of relativistic electrons for laser acceleration studies

System for increasing laser pulse rate

International Nuclear Information System (INIS)

1980-01-01

A technique of static elements is disclosed for combining a plurality of laser beams having time sequenced, pulsed radiation to achieve an augmented pulse rate. The technique may also be applied in a system for combining both time sequenced pulses and frequency distinct pulses for use in a system for isotope enrichment. (author)

Pulsed irradiation of enriched UO{sub 2} in the Annular Core Pulse Reactor (ACPR)

Energy Technology Data Exchange (ETDEWEB)

Schmidt, T R; Lucoff, D M; Reil, K O; Croucher, D W [Sandia Laboratories (United States)

1974-07-01

A series of experiments have been conducted in the Annular Core Pulse Reactor (ACPR) to determine the energy deposition and behavior of enriched UO{sub 2} under pulse conditions. In the experiment single unirradiated pellets with enrichments up to 25 percent were pulse heated to melt temperatures. Temperature and fission product inventory measurements were made and compared with neutron transport calculations. (author)

Pulsed neutron generator

International Nuclear Information System (INIS)

Bespalov, D.F.; Bykovskii, Yu.A.; Vergun, I.I.; Kozlovskii, K.I.; Kozyrev, Yu.P.; Leonov, R.K.; Simagin, B.I.; Tsybin, A.S.; Shikanov, A.Ie.

1986-03-01

The paper describes a new device for generating pulsed neutron fields, utilized in nuclear geophysics for carrying out pulsed neutron logging and activation analysis under field conditions. The invention employs a sealed-off neutron tube with a laser ion source which increases neutron yield to the level of 10 neutrons per second or higher. 2 refs., 1 fig

Coaxial pulse matching transformer

International Nuclear Information System (INIS)

Ledenev, V.V.; Khimenko, L.T.

1986-01-01

This paper describes a coaxial pulse matching transformer with comparatively simple design, increased mechanical strength, and low stray inductance. The transformer design makes it easy to change the turns ratio. The circuit of the device and an expression for the current multiplication factor are presented; experiments confirm the efficiency of the transformer. Apparatus with a coaxial transformer for producing high-power pulsed magnetic fields is designed (current pulses of 1-10 MA into a load and a natural frequency of 100 kHz)

Low power arcjet thruster pulse ignition

Science.gov (United States)

Sarmiento, Charles J.; Gruber, Robert P.

1987-01-01

An investigation of the pulse ignition characteristics of a 1 kW class arcjet using an inductive energy storage pulse generator with a pulse width modulated power converter identified several thruster and pulse generator parameters that influence breakdown voltage including pulse generator rate of voltage rise. This work was conducted with an arcjet tested on hydrogen-nitrogen gas mixtures to simulate fully decomposed hydrazine. Over all ranges of thruster and pulser parameters investigated, the mean breakdown voltages varied from 1.4 to 2.7 kV. Ignition tests at elevated thruster temperatures under certain conditions revealed occasional breakdowns to thruster voltages higher than the power converter output voltage. These post breakdown discharges sometimes failed to transition to the lower voltage arc discharge mode and the thruster would not ignite. Under the same conditions, a transition to the arc mode would occur for a subsequent pulse and the thruster would ignite. An automated 11 600 cycle starting and transition to steady state test demonstrated ignition on the first pulse and required application of a second pulse only two times to initiate breakdown.

Device for flattening statistically distributed pulses

International Nuclear Information System (INIS)

Il'kanaev, G.I.; Iskenderov, V.G.; Rudnev, O.V.; Teller, V.S.

1976-01-01

The description is given of a device that converts the series of statistically distributed pulses into a pseudo-uniform one. The inlet pulses switch over the first counter, and the second one is switched over by the clock pulses each time the uniformity of the counters' states is violated. This violation is recorded by the logic circuit which passes to the output the clock pulses in the amount equal to that of the pulses that reached the device inlet. Losses at the correlation between the light velocity and the sampling rate up to 0.3 do not exceed 0.7 per cent for the memory of pulse counters 3, and 0.035 per cent for memory 7

Simulation of neutrons and gamma pulse signal and research on the pulse shape discrimination technology

International Nuclear Information System (INIS)

Zuo Guangxia; He Bin; Xu Peng; Qiu Xiaolin; Ma Wenyan; Li Sufen

2012-01-01

In neutrons detection, it is important to discriminate the neutron signals from the gamma-ray background. In this article, simulation of neutrons and gamma pulse signals is developed based on the LabVIEW platform. Two digital algorithms of the charge comparison method and the pulse duration time method are realized using 10000 simulation signals. Experimental results show that neutron and gamma pulse signals can be discriminated by the two methods, and the pulse duration time method is better than the charge comparison method. (authors)

IAE pulsed electrostatic accelerator

International Nuclear Information System (INIS)

Afanas'ev, V.P.; Ganzhelyuk, M.L.; Kozlov, L.D.; Koltypin, E.A.; Molchanov, Yu.D.; Otroshchenko, G.A.; Yan'kov, G.B.

1976-01-01

The modernized pulse electrostatic accelerator using the klystron ion grouping and the beam interruption system prior to acceleration is described. The accelerator is modernized in order to improve parameters of a current pulse and to decrease the background in the measurement room. The ion beam of needed dimensions is obtained with the help of a high-frequency source and a beam grouping and deflection system. The general view of the beam grouping and deflection system is shown. The ion beam forming process is considered in detail. The modernized electrostatic accelerator permits to obtain a pulse current with a pulse length of 1.5 ns and an amplitude of 1.5 - 2 μA. With the repetition frequency of 2 MHz, the average target current is about 6 μA

Arecibo pulsar survey using ALFA: probing radio pulsar intermittency and transients

NARCIS (Netherlands)

Deneva, J.S.; Cordes, J.M.; McLaughlin, M.A.; Nice, D.J.; Lorimer, D.R.; Crawford, F.; Bhat, N.D.R.; Camilo, F.; Champion, D.J.; Freire, P.C.C.; Edel, S.; Kondratiev, V.I.; Hessels, J.W.T.; Jenet, F.A.; Kasian, L.; Kaspi, V.M.; Kramer, M.; Lazarus, P.; Ransom, S.M.; Stairs, I.H.; Stappers, B.W.; van Leeuwen, J.; Brazier, A.; Venkataraman, A.; Zollweg, J.A.; Bogdanov, S.

2009-01-01

We present radio transient search algorithms, results, and statistics from the ongoing Arecibo Pulsar ALFA (PALFA) survey of the Galactic plane. We have discovered seven objects through a search for isolated dispersed pulses. All of these objects are Galactic and have measured periods between 0.4

Square pulse linear transformer driver

Directory of Open Access Journals (Sweden)

A. A. Kim

2012-04-01

Full Text Available The linear transformer driver (LTD technological approach can result in relatively compact devices that can deliver fast, high current, and high-voltage pulses straight out of the LTD cavity without any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The usual LTD architecture [A. A. Kim, M. G. Mazarakis, V. A. Sinebryukhov, B. M. Kovalchuk, V. A. Vizir, S. N Volkov, F. Bayol, A. N. Bastrikov, V. G. Durakov, S. V. Frolov, V. M. Alexeenko, D. H. McDaniel, W. E. Fowler, K. LeCheen, C. Olson, W. A. Stygar, K. W. Struve, J. Porter, and R. M. Gilgenbach, Phys. Rev. ST Accel. Beams 12, 050402 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050402; M. G. Mazarakis, W. E. Fowler, A. A. Kim, V. A. Sinebryukhov, S. T. Rogowski, R. A. Sharpe, D. H. McDaniel, C. L. Olson, J. L. Porter, K. W. Struve, W. A. Stygar, and J. R. Woodworth, Phys. Rev. ST Accel. Beams 12, 050401 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050401] provides sine shaped output pulses that may not be well suited for some applications like z-pinch drivers, flash radiography, high power microwaves, etc. A more suitable power pulse would have a flat or trapezoidal (rising or falling top. In this paper, we present the design and first test results of an LTD cavity that generates such a type of output pulse by including within its circular array a number of third harmonic bricks in addition to the main bricks. A voltage adder made out of a square pulse cavity linear array will produce the same shape output pulses provided that the timing of each cavity is synchronized with the propagation of the electromagnetic pulse.

Near-field characteristics of radiating-wave simulator antenna based on TEM horn

International Nuclear Information System (INIS)

Tian Chunming; Ge Debiao

2004-01-01

This paper presents a novel antenna of NEMP (nuclear electromagnetic pulse) radiating-wave simulator, which is analyzed and optimized using the finite-difference time domain (FDTD) method. The intense voltage pulse is fed as the source to this antenna by the coaxial line. The parallel plate transmission line and the size of the transverse electromagnetic horn are optimized. The near field of antenna is analyzed, and the effects of the size on the near field are also given. The antenna designed in this paper can well satisfy the requirement for studying the EMP effects

Paternidade no Brasil: revisão sistemática de artigos empíricos

Directory of Open Access Journals (Sweden)

Mauro Luís Vieira

2014-01-01

Full Text Available El objetivo del estudio fue caracterizar la producción de artículos empíricos rela - cionados con el tema de la paternidad y su contribución al desarrollo del niño y de la familia, publicados entre 2000 y 2012 en revistas brasileñas indexadas en bases de datos IndexPsi, SciELO y PePSIC. Los descriptores usados fueron: “padre”, “paternidad” y “paternal”. Un centenar de artículos fueron analizados en su totalidad. En el 70% de ellos, los autores utilizaron el análisis cualitativo de los datos. Se observó la preferencia por el método de recolección de datos (60% y por la entrevista como técnica de recogida (47%. Entre los temas investigados se destacan: embarazo, parto y puerperio (25%, el ejercicio de la paternidad (22%, el desarrollo del niño (15%, la adolescencia (14% y concep - tos sobre el comportamiento paternal (13%. Estudios futuros deben investigar al padre en diferentes contextos y la división de papeles en la familia, la inte - gración de los enfoques cuantitativos y cualitativos y los estudios longitudinales.

Test Series 4: seismic-fragility tests of naturally-aged Exide EMP-13 battery cells

International Nuclear Information System (INIS)

Bonzon, L.L.; Hente, D.B.; Kukreti, B.M.; Schendel, J.; Tulk, J.D.; Janis, W.J.; Black, D.A.; Paulsen, G.D.; Aucoin, B.D.

1985-03-01

This report, the fourth in a test series of an extensive seismic research program, covers the testing of a 27-year old lead-antimony Exide EMP-13 cells from the recently decommissioned Shippingport Atomic Power Station. The Exide cells were tested in two configurations using a triaxial shake table: single-cell tests, rigidly mounted; and multicell (five-cell) tests, mounted in a typical battery rack. A total of nine electrically active cells was used in the two different cell configurations. None of the nine cells failed during the actual seismic tests when a range of ZPAs up to 1.5 g was imposed. Subsequent discharge capacity tests of five of the cells showed, however, that none of the cells could deliver the accepted standard of 80% of their rated electrical capacity for 3 hours. In fact, none of the 5 cells could deliver more than a 33% capacity. Two of the seismically tested cells and one untested, low capacity cell were disassembled for examination and metallurgical analyses. The inspection showed the cells to be in poor condition. The negative plates in the vicinity of the bus connections were extremely weak, the positive buses were corroded and brittle, negative and positive active material utilization was extremely uneven, and corrosion products littered the cells

Electromagnetic pulses, localized and causal

Science.gov (United States)

Lekner, John

2018-01-01

We show that pulse solutions of the wave equation can be expressed as time Fourier superpositions of scalar monochromatic beam wave functions (solutions of the Helmholtz equation). This formulation is shown to be equivalent to Bateman's integral expression for solutions of the wave equation, for axially symmetric solutions. A closed-form one-parameter solution of the wave equation, containing no backward-propagating parts, is constructed from a beam which is the tight-focus limit of two families of beams. Application is made to transverse electric and transverse magnetic pulses, with evaluation of the energy, momentum and angular momentum for a pulse based on the general localized and causal form. Such pulses can be represented as superpositions of photons. Explicit total energy and total momentum values are given for the one-parameter closed-form pulse.

Twenty-channel high-voltage pulse generators

International Nuclear Information System (INIS)

Anan'in, P.S.; Kashirin, A.P.

1980-01-01

A 20-channel high-voltage pulse generator operating with a mismatched load is described. The generator contains shaping lines 20 m long made of coaxial cable, a trigatron-type discharged, and isolating plates. The channel characteristic impedance is 50 Ohm. The maximum pulse amplitude is up to 15 kV on a high-resistance load and 7.5 kV on a matched one. The pulse duration is 100 ns at a pulse rise time of 12 ns, the delay introduced by the generator is 200 +-2.5 ns. Provision is made in the control circuit for compensation of the shaped pulse and separation of a pulse reflected from the load. The reflected pulse shape and amplitude characterize load parameters. Generator tests proved its high operational reliability (after 10 5 operations no significant changes in generator performances have been observed). The generator is intended for filmless data output from spark chambers

The Pulse Line Ion Accelerator Concept

Energy Technology Data Exchange (ETDEWEB)

Briggs, Richard J.

2006-02-15

The Pulse Line Ion Accelerator concept was motivated by the desire for an inexpensive way to accelerate intense short pulse heavy ion beams to regimes of interest for studies of High Energy Density Physics and Warm Dense Matter. A pulse power driver applied at one end of a helical pulse line creates a traveling wave pulse that accelerates and axially confines the heavy ion beam pulse. Acceleration scenarios with constant parameter helical lines are described which result in output energies of a single stage much larger than the several hundred kilovolt peak voltages on the line, with a goal of 3-5 MeV/meter acceleration gradients. The concept might be described crudely as an ''air core'' induction linac where the PFN is integrated into the beam line so the accelerating voltage pulse can move along with the ions to get voltage multiplication.

Induction effect of an electromagnetic pulse on transmission line

International Nuclear Information System (INIS)

Pazirandeh, A.; Maleki, P.; Sardari, D.

2004-01-01

Ever increasing demand for and vital importance of communication systems and power transmission to our industries, transportation to work, hospitals, and many other important places deemed necessary to have safety based design considerations. Many natural phenomena and man-made devices may generate powerful and intensive EMP, which is very harmful to the safe mode operation of electrical and communicational systems. In this paper we have calculated induced electric field and power induction due to lightening, nuclear explosion and similar events to the aerial and underground cables

Forensic Application of FM-CW and Pulse Radar

Energy Technology Data Exchange (ETDEWEB)

S. K. Koppenjan; R. S. Freeland; M. L. Miller; R. E. Yoder

2003-01-01

Ground-penetrating radar (GPR) technology has supplied vital assistance in criminal investigations. However, law enforcement personnel desire further developments such that the technology is rapidly deployable, and that it provides both a simple user interface and sophisticated target identification. To assist in the development of target identification algorithms, our efforts involve gathering background GPR data for the various site conditions and circumstances that often typify clandestine burials. For this study, forensic anthropologists established shallow-grave plots at The University of Tennessee Anthropological Research Facility (ARF) that are specific to GPR research. These plots contain donated human cadavers lying in various configurations and depths, surrounded by assorted construction material and backfill debris. We scanned the plots using two GPR technologies: (1) a multi-frequency synthetic-aperture FM-CW radar (200-700 MHz) (GPR-X) developed by the U.S. Department of Energy's (DOE) Special Technologies Laboratory (STL), Bechtel Nevada (Koppenjan et al., 2000), and (2) a commercial pulse radar (SIR-20) manufactured by Geophysical Survey Systems, Inc. (400 and 900 MHz)(GSSI). The sweep-frequency data show the large biological mass decomposing within the torso as encircled ''hot spots.'' The 400-MHz pulse radar exhibit major horizontal reflectors above the body, with shadow reflectors (horizontal multiples) occurring beneath the body at 60 cm depth. The 400-MHz antenna was able to discern the grave walls and folded tarp covering the lower body. Under these moist, clay-rich conditions, the 900-MHz antenna was able to penetrate slightly beyond 30 cm beneath the concrete layer. However, neither system was able to penetrate beyond a one meter depth in the moist, clay-rich soil (fine, mixed, thermic Typic Paleudalf). Example scans from each system are provided, along with a discussion of the survey protocol and general performance.

ENDOR with band-selective shaped inversion pulses

Science.gov (United States)

Tait, Claudia E.; Stoll, Stefan

2017-04-01

Electron Nuclear DOuble Resonance (ENDOR) is based on the measurement of nuclear transition frequencies through detection of changes in the polarization of electron transitions. In Davies ENDOR, the initial polarization is generated by a selective microwave inversion pulse. The rectangular inversion pulses typically used are characterized by a relatively low selectivity, with full inversion achieved only for a limited number of spin packets with small resonance offsets. With the introduction of pulse shaping to EPR, the rectangular inversion pulses can be replaced with shaped pulses with increased selectivity. Band-selective inversion pulses are characterized by almost rectangular inversion profiles, leading to full inversion for spin packets with resonance offsets within the pulse excitation bandwidth and leaving spin packets outside the excitation bandwidth largely unaffected. Here, we explore the consequences of using different band-selective amplitude-modulated pulses designed for NMR as the inversion pulse in ENDOR. We find an increased sensitivity for small hyperfine couplings compared to rectangular pulses of the same bandwidth. In echo-detected Davies-type ENDOR, finite Fourier series inversion pulses combine the advantages of increased absolute ENDOR sensitivity of short rectangular inversion pulses and increased sensitivity for small hyperfine couplings of long rectangular inversion pulses. The use of pulses with an almost rectangular frequency-domain profile also allows for increased control of the hyperfine contrast selectivity. At X-band, acquisition of echo transients as a function of radiofrequency and appropriate selection of integration windows during data processing allows efficient separation of contributions from weakly and strongly coupled nuclei in overlapping ENDOR spectra within a single experiment.

Valor da Marca: Teste Empírico da Importância das Dimensões Formadoras do Valor da Marca na Perspectiva do Consumidor no Contexto Brasileiro

Directory of Open Access Journals (Sweden)

Luiz Sergio Costa

2012-09-01

Full Text Available O presente estudo investigou a importância das dimensões formadoras do valor da marca na perspectiva do consumidor no contexto brasileiro, mediante o teste empírico do modelo proposto por Yoo e Donthu (2001. Outros autores validaram a multidimensionalidade do conceito de valor da marca na perspectiva do consumidor (Myers, 2003; Villarejo-Ramos e Sánchez-Franco, 2005; Vargas e Luce, 2006. Todavia, estes estudos divergiram quanto ao número de dimensões e suas respectivas importâncias, evidenciando um hiato na literatura. Para responder as perguntas deste estudo, foi realizada uma survey com 636 consumidores. Os dados coletados foram submetidos à técnica estatística de análise fatorial confirmatória (CFA e modelagem de equações estruturais (SEM. Os resultados do estudo sugerem a validade parcial do modelo de Yoo e Donthu (2001. A importância das dimensões lealdade e qualidade percebida na formação do valor da marca na perspectiva do consumidor foram suportadas empiricamente. Entretanto, a inexistência de relação significativa entre consciência / associações e valor geral da marca sugere a necessidade de mais estudos, seja para validar essa relação, seja para propor novas escalas para mensurar o construto de consciência / associações à marca. DOI: 10.5585/remark.v11i2.2357

The Toulouse pulsed magnet facility

International Nuclear Information System (INIS)

2006-01-01

The 'Laboratoire National des Champs Magnetiques Pulses' (LNCMP) is an international user facility providing access to pulsed magnetic fields up to and beyond 60 T. The laboratory disposes of 10 magnet stations equipped with long-pulse magnets operating in the 35-60 T range and a short-pulse system reaching magnetic fields in excess of 70 T. The experimental infrastructure includes various high and low-temperature systems ranging from ordinary flow-type cryostats to dilution refrigerators reaching 50 mK, as well as different types of high-pressure cells. Experimental techniques include magnetization, transport, luminescence, IR-spectroscopy and polarimetry. The LNCMP pursues an extensive in-house research program focussing on all technological and scientific aspects of pulsed magnetic fields. Recent technical developments include the implementation of 60 T rapid-cooling coils, an 80 T prototype, a pulsed dipole magnet for optical investigations of dilute matter and a transportable horizontal access magnet for small angle x-ray scattering experiments. Scientific activities cover a variety of domains, including correlated electron systems, magnetism, semiconductors and nanoscience

A 16.3 pJ/pulse low-complexity and energy-efficient transmitter with adjustable pulse parameters

International Nuclear Information System (INIS)

Jiang Jun; Zhao Yi; Shao Ke; Chen Hu; Xia Lingli; Hong Zhiliang

2011-01-01

This paper presents a novel, fully integrated transmitter for 3-5 GHz pulsed UWB. The BPSK modulation transmitter has been implemented in SMIC CMOS 0.13 μm technology with a 1.2-V supply voltage and a die size of 0.8 x 0.95 mm 2 . This transmitter is based on the impulse response filter method, which uses a tunable R paralleled with a LC frequency selection network to realize continuously adjustable pulse parameters, including bandwidth, width and amplitude. Due to the extremely low duty of the pulsed UWB, a proposed output buffer is employed to save power consumption significantly. Finally, measurement results show that the transmitter consumes only 16.3 pJ/pulse to achieve a pulse repetition rate of 100 Mb/s. Generated pulses strictly comply with the FCC spectral mask. The continuously variable pulse width is from 900 to 1.5 ns and the amplitude with the minimum 178 mVpp and the maximum 432 mVpp can be achieved. (semiconductor integrated circuits)

Herophilus on pulse

Directory of Open Access Journals (Sweden)

Afonasin, Eugene

2015-01-01

Full Text Available The first detailed study of the pulse (sphygmology is associated in antiquity with Herophilus (the end of the 4th century BCE, an Alexandrian physician, renowned for his anatomical discoveries. The scholars also attribute to him a discovery of a portable and adjustable water-clock, used for measuring ‘natural’ and ‘unnatural’ pulse and, accordingly, temperature of the patient. In the article we translate the principal ancient evidences and comment upon them. We study both the practical aspects of ancient sphygmology and the theoretical speculations associated with it. Ancient theory of proportion and musical harmony allowed to build a classification of the pulses, but the medical experience did not fit well in the Procrustean bed of this rather simple theory.

Radiobiological response to ultra-short pulsed megavoltage electron beams of ultra-high pulse dose rate.

Science.gov (United States)

Beyreuther, Elke; Karsch, Leonhard; Laschinsky, Lydia; Leßmann, Elisabeth; Naumburger, Doreen; Oppelt, Melanie; Richter, Christian; Schürer, Michael; Woithe, Julia; Pawelke, Jörg

2015-08-01

In line with the long-term aim of establishing the laser-based particle acceleration for future medical application, the radiobiological consequences of the typical ultra-short pulses and ultra-high pulse dose rate can be investigated with electron delivery. The radiation source ELBE (Electron Linac for beams with high Brilliance and low Emittance) was used to mimic the quasi-continuous electron beam of a clinical linear accelerator (LINAC) for comparison with electron pulses at the ultra-high pulse dose rate of 10(10) Gy min(-1) either at the low frequency of a laser accelerator or at 13 MHz avoiding effects of prolonged dose delivery. The impact of pulse structure was analyzed by clonogenic survival assay and by the number of residual DNA double-strand breaks remaining 24 h after irradiation of two human squamous cell carcinoma lines of differing radiosensitivity. The radiation response of both cell lines was found to be independent from electron pulse structure for the two endpoints under investigation. The results reveal, that ultra-high pulse dose rates of 10(10) Gy min(-1) and the low repetition rate of laser accelerated electrons have no statistically significant influence (within the 95% confidence intervals) on the radiobiological effectiveness of megavoltage electrons.

Designs of pulsed power cryogenic transformers

International Nuclear Information System (INIS)

Singh, S.K.; Heyne, C.J.; Hackowrth, D.T.; Shestak, E.J.; Eckels, P.W.; Rogers, J.D.

1988-01-01

The Westinghouse Electric Corporation has completed designs of three pulsed power cryogenic transformers of three pulsed power cryogenic transformers for the Los Alamos National Laboratory. These transformers will be configured to transfer their stored energy sequentially to an electro-magnetic launcher and form a three-stage power supply. The pulse transformers will act as two winding energy storage solenoids which provide a high current and energy pulse compression by transforming a 50 kA power supply into a megamp level power supply more appropriate for the electromagnetic launcher duty. This system differs from more traditional transformer applications in that significant current levels do not exists simultaneously in the two windings of the pulse transformer. This paper describes the designs of the pulsed power cryogenic transformers

Parental preference and perspectives on continuous pulse oximetry in infants and children with bronchiolitis

Directory of Open Access Journals (Sweden)

Hendaus MA

2018-04-01

Full Text Available Mohamed A Hendaus,1,2 Suzan Nassar,3 Bassil A Leghrouz,3 Ahmed H Alhammadi,1,2 Mohammed Alamri4 1Department of Pediatrics, Section of Academic General Pediatrics, Sidra Medicine, Doha, Qatar; 2Department of Clinical Pediatrics, Weill Cornell Medicine, Doha, Qatar; 3Department of Pediatrics, Hamad General Corporation, Doha, Qatar; 4Pediatric Emergency Center, Hamad General Corporation, Doha, Qatar Objective: The purpose of the study was to investigate parental preference of continuous pulse oximetry in infants and children with bronchiolitis. Materials and methods: A cross-sectional prospective study was conducted at Hamad Medical Corporation in Qatar. Parents of infants and children <24 months old and hospitalized with bronchiolitis were offered an interview survey. Results: A total of 132 questionnaires were completed (response rate 100%. Approximately 90% of participants were 20–40 years of age, and 85% were females. The mean age of children was 7.2±5.8 months. Approximately eight in ten parents supported the idea of continuous pulse oximetry in children with bronchiolitis. Almost 43% of parents believed that continuous pulse-oximetry monitoring would delay their children’s hospital discharge. Interestingly, approximately 85% of caregivers agreed that continuous pulse oximetry had a good impact on their children’s health. In addition, around one in two of the participants stated that good bedside examinations can obviate the need for continuous pulse oximetry. Furthermore, 80% of parents believed that continuous pulse-oximetry monitoring would give the health-care provider a good sense of security regarding the child’s health. Finally, being a male parent was associated with significantly increased risk of reporting unnecessary fatigue, attributed to the sound of continuous pulse oximetry (P=0.031. Conclusion: Continuous pulse-oximetry monitoring in children with bronchiolitis was perceived as reassuring for parents. Involving parents

Sandia Pulsed Reactor Facility (SPRF) calculator-assisted pulse analysis and display system

International Nuclear Information System (INIS)

Estes, B.F.; Berry, D.T.

1980-02-01

Two solid-metal fast burst type reactors (SPR II and SPR III) are operated at the Sandia Pulsed Reactor Facility. Since startup of the reactors, oscilloscope traces have been used to record (by camera) the pulse (power) shape while log N systems have measured initial reactor period. Virtually no other pulse information is available. A decision was made to build a system that could collect the basic input data available from the reactor - fission chambers, photodiodes, and thermocouples - condition the signals and output the various parameters such as power, energy, temperature, period and lifetime on hard copy that would provide a record for operations personnel as well as the experimenter. Because the reactors operate in short time frames - pulse operation - it is convenient to utilize the classical Nordheim-Fuchs approximation of the diffusion equation to describe reactor behavior. This report describes the work performed to date in developing the calculator system and analytical models for computing the desired parameters

Pulsed high-power beams

International Nuclear Information System (INIS)

Reginato, L.L.; Birx, D.L.

1988-01-01

The marriage of induction linac technology with nonlinear magnetic modulators has produced some unique capabilities. It is now possible to produce short-pulse electron beams with average currents measured in amperes, at gradients approaching 1-MeV/m, and with power efficiencies exceeding 50%. This paper reports on a 70-MeV, 3-kA induction accelerator (ETA II) constructed at the Lawrence Livermore National Laboratory that incorporates the pulse technology concepts that have evolved over the past several years. The ETA II is a linear induction accelerator and provides a test facility for demonstration of the high-average-power components and high-brightness sources used in such accelerators. The pulse drive of the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak-power capability, repetition rates exceeding 1 kHz, and excellent reliability

Pulse Compression of Phase-matched High Harmonic Pulses from a Time-Delay Compensated Monochromator

Directory of Open Access Journals (Sweden)

Ito Motohiko

2013-03-01

Full Text Available Pulse compression of single 32.6-eV high harmonic pulses from a time-delay compensated monochromator was demonstrated down to 11±3 fs by compensating the pulse front tilt. The photon flux was intensified up to 5.7×109 photons/s on target by implementing high harmonic generation under a phase matching condition in a hollow fiber used for increasing the interaction length.

A digital long pulse integrator

International Nuclear Information System (INIS)

Broesch, J.D.; Strait, E.J.; Snider, R.T.

1996-10-01

A prototype digital integrator with very long integration capabilities has been developed and field tested on an inductive magnetic sensor on the DIII-D Tokamak. The integrator is being developed for use on ITER with a pulse length of 1000 s, and has direct applications for other long pulse Tokamaks. Inductive magnetic sensors are routinely used on existing Tokamaks, are well understood, and are extremely robust, however, they require integration of the signal to determine the magnetic field strength. The next generation of Tokamaks, will have pulse lengths of 1000 s or longer, require integrators with drift and noise characteristics compatible with the very long pulse lengths. This paper will discuss the architecture, algorithms, and programming of the Long Pulse Integrator (LPI). Of particular interest are the noise control and the built-in offset correction techniques used in this application

Dynamic pulse difference circuit

International Nuclear Information System (INIS)

Erickson, G.L.

1978-01-01

A digital electronic circuit of especial use for subtracting background activity pulses in gamma spectrometry is disclosed which comprises an up-down counter connected to count up with signal-channel pulses and to count down with background-channel pulses. A detector responsive to the count position of the up-down counter provides a signal when the up-down counter has completed one scaling sequence cycle of counts in the up direction. In an alternate embodiment, a detector responsive to the count position of the up-down counter provides a signal upon overflow of the counter

Attosecond pulse generation in noble gases in the presence of extreme high intensity THz pulses

International Nuclear Information System (INIS)

Balogh, E.; Varju, K.

2010-01-01

Complete text of publication follows. The shortest - attosecond - light pulses available today are produced by high harmonic generation (HHG) of near-infrared (NIR) laser pulses in noble gas jets, providing a broad spectral plateau of XUV radiation ending in a cutoff. The minimum pulse duration is determined by the achievable bandwidth (i.e. the position of the cutoff), and the chirp of the produced pulses. The extension of the cutoff by increasing the laser intensity is limited by the depletion and phase matching problems of the medium. An alternative method demonstrated to produce higher harmonic orders is by using longer pump pulse wavelength, with the disadvantage of decreased efficiency. Recently it was shown that application of a quasi-DC high strength electric field results in an increase of more than a factor of two in the order of efficiently generated high harmonics. However, the possibility to implement the method proposed in [3] of using a CO 2 laser to create a quasi-DC field for assisting HHG of the NIR laser is questionable, because it's technically very challenging to synchronize pulses from different laser sources. Alternatively, synchronous production of THz pulses with the NIR laser pulse offers a more promising route. The first numerical test of this idea has been reported in [4]. In this contribution we further investigate the method for realistic THz field strengths and short driving pulses, exploring the effect of longer pump laser wavelength on the process. We assume the presence of high intensity THz pulses for supplying the high-strength quasi-DC electric field. The spectrum as well as the chirp of the produced radiation is calculated. We use the non-adiabatic saddle point method to determine the generated radiation described in [6]. We simulate harmonic generation in noble gas atoms, with few cycle NIR pulses of peak intensity at and above 2 x 10 14 W/cm 2 (388 MV/cm) and wavelengths 800 nm and 1560 nm. The THz field strength is varied

Acousto-optic replication of ultrashort laser pulses

Science.gov (United States)

Yushkov, Konstantin B.; Molchanov, Vladimir Ya.; Ovchinnikov, Andrey V.; Chefonov, Oleg V.

2017-10-01

Precisely controlled sequences of ultrashort laser pulses are required in various scientific and engineering applications. We developed a phase-only acousto-optic pulse shaping method for replication of ultrashort laser pulses in a TW laser system. A sequence of several Fourier-transform-limited pulses is generated from a single femtosecond laser pulse by means of applying a piecewise linear phase modulation over the whole emission spectrum. Analysis demonstrates that the main factor which limits maximum delay between the pulse replicas is spectral resolution of the acousto-optic dispersive delay line used for pulse shaping. In experiments with a Cr:forsterite laser system, we obtained delays from 0.3 to 3.5 ps between two replicas of 190 fs transform-limited pulses at the central wavelength of laser emission, 1230 nm.

Coherent combining pulse bursts in time domain

Science.gov (United States)

Galvanauskas, Almantas

2018-01-09

A beam combining and pulse stacking technique is provided that enhances laser pulse energy by coherent stacking pulse bursts (i.e. non-periodic pulsed signals) in time domain. This energy enhancement is achieved by using various configurations of Fabry-Perot, Gires-Tournois and other types of resonant cavities, so that a multiple-pulse burst incident at either a single input or multiple inputs of the system produces an output with a solitary pulse, which contains the summed energy of the incident multiple pulses from all beams. This disclosure provides a substantial improvement over conventional coherent-combining methods in that it achieves very high pulse energies using a relatively small number of combined laser systems, thus providing with orders of magnitude reduction in system size, complexity, and cost compared to current combining approaches.

Determination of pseudo multi-pulse production rate in GM counters by correlation analysis between signal pulses

International Nuclear Information System (INIS)

Hashimoto, Kengo; Ueda, Taizou

1996-01-01

A technique, based on the correlation analysis of signal pulses in time sequence, is proposed to determine the production rate of the pseudo multi-pulse in Geiger-Mueller (GM) counter. With a multi-channel scaler initiated by a signal pulse, subsequent pulses are recorded in sequence. The production of the multi-pulse increases the counting probability immediately after the initiation. By examining the deviation of the measured probability from the ideal counting probability, the production rate and the average lag time to produce the multi-pulse can be determined. By the use of the present technique, the production rate and the average lag time were obtained for the various GM tubes. These results indicate that the consumption of the quench gas results in a significant increase in the production rate but little variation in the lag time, and that the lag time strongly depends on the tube diameter. (author)

Breaking time-resolution limits in pulse radiolysis

International Nuclear Information System (INIS)

Yang Jinfeng; Kondoh, Takafumi; Norizawa, Kimihiro; Yoshida, Yoichi; Tagawa, Seiichi

2009-01-01

Pulse radiolysis, which is a time-resolved stroboscopic method based on ultrashort electron pulse and ultrashort analyzing light, is widely used for the study of the chemical kinetics and radiation primary processes or reactions. Although it has become possible to use femtosecond-pulse electron beam and femtosecond laser light in pulse radiolysis, the resolution is limited by the difference in group velocities of the electrons and the light in sample. In this contribution, we introduce a concept of equivalent velocity spectroscopy (EVS) into pulse radiolysis and demonstrate the methodology experimentally. In EVS, both the electron and the analyzing light pulses precisely overlap at every point in the sample and throughout the propagation time by rotating the electron pulse. The advance allows us to overcome the resolution degradation due to the different group velocity. We also present a method for measuring the rotated angle of the electron pulse and a technique for rotating the electron pulse with a deflecting cavity.

Custom pulse generator for RPC testing

International Nuclear Information System (INIS)

Gil, A.; Castro, E.; Diaz, J.; Fonte, P.; Garzon, J.A.; Montes, N.; Zapata, M.

2009-01-01

We present a pulse generator able to generate pulses statistically similar to the ones produced by RPC cells. The device generates up to four arrays of fast and narrow random-like pulses. Polarity, maximum amplitudes, widths and pulse rate in each channel may be modified independently in order to simulate different RPC setups and environments. This portable and cost-effective pulse generator is a versatile instrument for testing FE-Electronics and different real detector features related with the signal propagation inside the detector. It has been developed in the framework of the ESTRELA project of the HADES experiment at GSI.

Temporal Airy pulses control cell poration

Directory of Open Access Journals (Sweden)

S. Courvoisier

2016-07-01

Full Text Available We show that spectral phase shaping of fs-laser pulses can be used to optimize laser-cell membrane interactions in water environment. The energy and peak intensity thresholds required for cell poration with single pulse in the nJ range can be significantly reduced (25% reduction in energy and 88% reduction in peak intensity by using temporal Airy pulses, controlled by positive third order dispersion, as compared to bandwidth limited pulses. Temporal Airy pulses are also effective to control the morphology of the induced pores, with prospective applications from cellular to tissue opto-surgery and transfection.

Infrared study of the Crab pulsar: The ''shoulder'' pulse and the 3.45 micron pulse profile

International Nuclear Information System (INIS)

Middleditch, J.; Pennypacker, C.; Burns, M.S.

1983-01-01

Infrared measurements of the Crab pulsar with the NASA IRTF 3.0 m telescope show that the spectrum of the main pulse turns downward for wavelengths longer than 3 μm. The ''shoulder'' pulse discovered by Pennypacker is measured in the 0.9--2.4 μm region, but disappears at 3.5 μm. This pulse rises from 0 to 20% of the height of the main pulse within 1 to 2 ms after the main pulse peak and decays with a 4 to 5 ms time constant. Excess infrared flux also appears after the interpulse. The main peak itself may be narrower at 3.45 μm than in the optical to 2.2 μm band

Control of giant pulse duration in neodymium mini lasers with controllable cavity length and pulsed pumping

International Nuclear Information System (INIS)

Berenberg, Vladimir A.; Cervantes, Miguel A.; Terpugov, Vladimir S.

2006-01-01

In a solid-state laser incident on aLiNdP4O12 crystal, pumped by a short light pulse, giant pulse oscillation without the use of resonator Q switching is realized. Tuning of the oscillation pulse duration from 2 up to 20 ns is achieved by changing the cavity length from 24 to 3 mm, respectively. Our analysis of this mode of laser radiation is made on the basis of the rate equations. The factors influencing oscillation pulse duration a reinvestigated. It is shown that in a limiting case the minimal value of the pulse duration is limited by only the rate of excitation transfer from the pumping band to the metastable level

Laser system using ultra-short laser pulses

Science.gov (United States)

Dantus, Marcos [Okemos, MI; Lozovoy, Vadim V [Okemos, MI; Comstock, Matthew [Milford, MI

2009-10-27

A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

Picoseconds pulse generation and pulse width determination processes of a distributed feedback dye laser

International Nuclear Information System (INIS)

Abdul Ghani, B.; Hammadi, M.

2004-08-01

A mathematical model has been developed to describe the dynamic emission of Nd-glass, distributed feedback dye laser (DFDL), and periodical grating temperature. The suggested model allows the investigation of the time behavior of Nd-glass laser and DFDL pulsed. Moreover, it allows studying the effect of the laser input parameters of Nd-glass laser on the spectral characteristics of the output DFDL pulses such as pulse width, delay time, and time separation

A Novel Transcranial Magnetic Stimulator Inducing Near Rectangular Pulses with Controllable Pulse Width (cTMS)

Science.gov (United States)

Jalinous, Reza; Lisanby, Sarah H.

2013-01-01

A novel transcranial magnetic stimulation (TMS) device with controllable pulse width (PW) and near rectangular pulse shape (cTMS) is described. The cTMS device uses an insulated gate bipolar transistor (IGBT) with appropriate snubbers to switch coil currents up to 7 kA, enabling PW control from 5 μs to over 100 μs. The near-rectangular induced electric field pulses use 22–34% less energy and generate 67–72% less coil heating compared to matched conventional cosine pulses. CTMS is used to stimulate rhesus monkey motor cortex in vivo with PWs of 20 to 100 μs, demonstrating the expected decrease of threshold pulse amplitude with increasing PW. The technological solutions used in the cTMS prototype can expand functionality, and reduce power consumption and coil heating in TMS, enhancing its research and therapeutic applications. PMID:18232369

Theoretical and Experimental Investigations of Coincidences in Poisson Distributed Pulse Trains and Spectral Distortion Caused by Pulse Pileup.

Science.gov (United States)

Bristow, Quentin

1990-01-01

Part one of this two-part study is concerned with the multiple coincidences in pulse trains from X-ray and gamma radiation detectors which are the cause of pulse pileup. A sequence of pulses with inter-arrival times less than tau, the resolving time of the pulse-height analysis system used to acquire spectra, is called a multiple pulse string. Such strings can be classified on the basis of the number of pulses they contain, or the number of resolving times they cover. The occurrence rates of such strings are derived from theoretical considerations. Logic circuits were devised to make experimental measurements of multiple pulse string occurrence rates in the output from a NaI(Tl) scintillation detector over a wide range of count rates. Markov process theory was used to predict state transition rates in the logic circuits, enabling the experimental data to be checked rigorously for conformity with those predicted for a Poisson distribution. No fundamental discrepancies were observed. Part two of the study is concerned with a theoretical analysis of pulse pileup and the development of a discrete correction algorithm, based on the use of a function to simulate the coincidence spectrum produced by partial sums of pulses. Monte Carlo simulations, incorporating criteria for pulse pileup inherent in the operation of modern ADC's, were used to generate pileup spectra due to coincidences between two pulses, (1st order pileup) and three pulses (2nd order pileup), for different semi-Gaussian pulse shapes. Coincidences between pulses in a single channel produced a basic probability density function spectrum which can be regarded as an impulse response for a particular pulse shape. The use of a flat spectrum (identical count rates in all channels) in the simulations, and in a parallel theoretical analysis, showed the 1st order pileup distorted the spectrum to a linear ramp with a pileup tail. The correction algorithm was successfully applied to correct entire spectra for 1st and

A study of new pulse auscultation system.

Science.gov (United States)

Chen, Ying-Yun; Chang, Rong-Seng

2015-04-14

This study presents a new type of pulse auscultation system, which uses a condenser microphone to measure pulse sound waves on the wrist, captures the microphone signal for filtering, amplifies the useful signal and outputs it to an oscilloscope in analog form for waveform display and storage and delivers it to a computer to perform a Fast Fourier Transform (FFT) and convert the pulse sound waveform into a heartbeat frequency. Furthermore, it also uses an audio signal amplifier to deliver the pulse sound by speaker. The study observed the principles of Traditional Chinese Medicine's pulsing techniques, where pulse signals at places called "cun", "guan" and "chi" of the left hand were measured during lifting (100 g), searching (125 g) and pressing (150 g) actions. Because the system collects the vibration sound caused by the pulse, the sensor itself is not affected by the applied pressure, unlike current pulse piezoelectric sensing instruments, therefore, under any kind of pulsing pressure, it displays pulse changes and waveforms with the same accuracy. We provide an acquired pulse and waveform signal suitable for Chinese Medicine practitioners' objective pulse diagnosis, thus providing a scientific basis for this Traditional Chinese Medicine practice. This study also presents a novel circuit design using an active filtering method. An operational amplifier with its differential features eliminates the interference from external signals, including the instant high-frequency noise. In addition, the system has the advantages of simple circuitry, cheap cost and high precision.

Pulse height model for deuterated scintillation detectors

International Nuclear Information System (INIS)

Wang, Haitang; Enqvist, Andreas

2015-01-01

An analytical model of light pulse height distribution for finite deuterated scintillation detectors is created using the impulse approximation. Particularly, the energy distribution of a scattered neutron is calculated based on an existing collision probability scheme for general cylindrical shaped detectors considering double differential cross-sections. The light pulse height distribution is analytically and numerically calculated by convoluting collision sequences with the light output function for an EJ-315 detector from our measurements completed at Ohio University. The model provides a good description of collision histories capturing transferred neutron energy in deuterium-based scintillation materials. The resulting light pulse height distribution details pulse compositions and their corresponding contributions. It shows that probabilities of neutron collision with carbon and deuterium nuclei are comparable, however the light pulse amplitude due to collisions with carbon nuclei is small and mainly located at the lower region of the light pulse distribution axis. The model can explore those neutron interaction events that generate pulses near or below a threshold that would be imposed in measurements. A comparison is made between the light pulse height distributions given by the analytical model and measurements. It reveals a significant probability of a neutron generating a small light pulse due to collisions with carbon nuclei when compared to larger light pulse generated by collisions involving deuterium nuclei. This model is beneficial to understand responses of scintillation materials and pulse compositions, as well as nuclei information extraction from recorded pulses.

Pulsed-DC selfsputtering of copper

International Nuclear Information System (INIS)

Wiatrowski, A; Posadowski, W M; Radzimski, Z J

2008-01-01

At standard magnetron sputtering conditions (argon pressure ∼0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (∼550W/cm 2 ). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%

Pulsed-DC selfsputtering of copper

Science.gov (United States)

Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.

2008-03-01

At standard magnetron sputtering conditions (argon pressure ~0.5 Pa) inert gas particles are often entrapped in the formed films. Inert gas contamination can be eliminated by using the self-sustained magnetron sputtering process because it is done in the absence of the inert gas atmosphere. The self-sustained sputtering (SSS) gives also a unique condition during the transport of sputtered particles to the substrate. It is especially useful for filling high aspect ratio submicron scale structures for microelectronics. So far it has been shown that the self-sputtering process can be sustained in the DC operation mode (DC-SSS) only. The main disadvantage of DC-SSS process is instability related to possible arc formation. Usage of pulsed sputtering, similarly to reactive pulsed magnetron sputtering, could eliminate this problem. In this paper results of pulsed-DC self-sustained magnetron sputtering (pulsed DC-SSS) of copper are presented for the first time. The planar magnetron equipped with a 50 mm in diameter and 6 mm thick copper target was powered by DC-power supply modulated by power switch. The maximum target power was about 11 kW (~550W/cm2). The magnetron operation was investigated as a function of pulsing frequency (20-100 kHz) and duty factor (50-90%). The discharge extinction pressure was determined for these conditions. The plasma emission spectra (400-410nm range) and deposition rates were observed for both DC and pulsed DC sustained self-sputtering processes. The presented results illustrate that stable pulsed DC-SSS process can be obtained at pulsing frequency in the range of 60-100 kHz and duty factor of 70-90%.

Pulsed Corona for Sustainable Technology

International Nuclear Information System (INIS)

Heesch, E.J.M. van; Pemen, A.J.M.; Yan, K.; Blom, P.P.M.; Huijbrechts, P.A.H.J.; Der Laan, P.C.T. van

2000-01-01

Highly active coronas with a peak power of up to 25 MW p/m corona wire and kJ/liter energy densities in the streamer channels can be produced by pulsed power. Since the voltage pulses are short, full breakdown does not occur even though the discharge currents are hundreds of Amperes. A matched pulsed power source can deposit up to 80% of its electrical energy into such a controlled discharge. Reliable and efficient sources characterized by 100 kV,150 ns wide pulses at 1000 Hz have passed 400 hours of operation. The area of applications is growing: VOC control, hot gas cleanup, water and air purification and sterilization. (author)

Fast differential pulse discriminator-counter

International Nuclear Information System (INIS)

Shelevoj, K.D.

1985-01-01

The flowsheet of a differential pulse discriminator counter is described; the result of discrimination here is independent from the shape of the input pulse. Rate of the analysis of input pulses with minimum amplitude up to 0.3 mV coming out from the photomultiplier makes up 220 MHz. The flowsheet of the discriminator used in the system of photon counting for atmosphere probing is presented

PULSED MOLECULAR BEAM PRODUCTION WITH NOZZLES

Energy Technology Data Exchange (ETDEWEB)

Hagena, Otto-Friedrich

1963-05-15

Molecular beam experiments that can be carried out in pulsed operation may be performed at considerably reduced expense for apparatus if, for pulse generation, the gas supply to the beam production system is interrupted as opposed to the usual steady molecular beam. This technique is studied by measuring intensity vs time of molecular beam impulses of varying length, how fast and through which intermediate states the initial intensity of the impulse attains equilibrium, and in which way the intensity of the molecular-beam impulse is affected by the pulse length and by increasing pressure in the first pressure stage. For production of pulses, a magnetically actuated, quick shutting, valve is used whose scaling area is the inlet cone of the nozzle used for the beam generation. The shortest pulses produced had a pulse length of 1.6 ms. (auth)

CAMAC-compatible differential pulse discriminator-counter

International Nuclear Information System (INIS)

Tselikov, I.V.

1988-01-01

A differential pulse discriminator-counter for a Moessbauer spectrometer is described. Input pulses are collected according to the following algorithm; a pulse is admitted into the channel depending on whether or not the preceding pulse fell into the discrimination window. The circuit does not contain delay lines to allow for the delay lines to allow for the delay of the signal from the upper-level discriminator with respect to the signal from the lower-level discriminator due to the finite rise time of the input pulses, which makes it possible to reduce the dead time of the discriminator to the actuation time of the threshold circuits. The pulse count rate is 150 MHz, the input amplitude is +/-3 V, the dead time is 6 nsec, and the delay from input to output is 14 nsec. The unit is CAMAC-compatible

Comparison of pulsed electron beam-annealed and pulsed ruby laser-annealed ion-implanted silicon

International Nuclear Information System (INIS)

Wilson, S.R.; Appleton, B.R.; White, C.W.; Narayan, J.; Greenwald, A.C.

1978-11-01

Recently two new techniques, pulsed electron beam annealing and pulsed laser annealing, have been developed for processing ion-implanted silicon. These two types of anneals have been compared using ion-channeling, ion back-scattering, and transmission electron microscopy (TEM). Single crystal samples were implanted with 100 keV As + ions to a dose of approx. 1 x 10 16 ions/cm 2 and subsequently annealed by either a pulsed Ruby laser or a pulsed electron beam. Our results show in both cases that the near-surface region has melted and regrown epitaxially with nearly all of the implanted As (97 to 99%) incroporated onto lattice sites. The analysis indicates that the samples are essentially defect free and have complete electrical recovery